Asymmetric effects of daytime and night-time warming on Northern Hemisphere vegetation.

PubMed

Peng, Shushi; Piao, Shilong; Ciais, Philippe; Myneni, Ranga B; Chen, Anping; Chevallier, Frédéric; Dolman, Albertus J; Janssens, Ivan A; Peñuelas, Josep; Zhang, Gengxin; Vicca, Sara; Wan, Shiqiang; Wang, Shiping; Zeng, Hui

2013-09-05

Temperature data over the past five decades show faster warming of the global land surface during the night than during the day. This asymmetric warming is expected to affect carbon assimilation and consumption in plants, because photosynthesis in most plants occurs during daytime and is more sensitive to the maximum daily temperature, Tmax, whereas plant respiration occurs throughout the day and is therefore influenced by both Tmax and the minimum daily temperature, Tmin. Most studies of the response of terrestrial ecosystems to climate warming, however, ignore this asymmetric forcing effect on vegetation growth and carbon dioxide (CO2) fluxes. Here we analyse the interannual covariations of the satellite-derived normalized difference vegetation index (NDVI, an indicator of vegetation greenness) with Tmax and Tmin over the Northern Hemisphere. After removing the correlation between Tmax and Tmin, we find that the partial correlation between Tmax and NDVI is positive in most wet and cool ecosystems over boreal regions, but negative in dry temperate regions. In contrast, the partial correlation between Tmin and NDVI is negative in boreal regions, and exhibits a more complex behaviour in dry temperate regions. We detect similar patterns in terrestrial net CO2 exchange maps obtained from a global atmospheric inversion model. Additional analysis of the long-term atmospheric CO2 concentration record of the station Point Barrow in Alaska suggests that the peak-to-peak amplitude of CO2 increased by 23 ± 11% for a +1 °C anomaly in Tmax from May to September over lands north of 51° N, but decreased by 28 ± 14% for a +1 °C anomaly in Tmin. These lines of evidence suggest that asymmetric diurnal warming, a process that is currently not taken into account in many global carbon cycle models, leads to a divergent response of Northern Hemisphere vegetation growth and carbon sequestration to rising temperatures.

Strong impacts of daily minimum temperature on the green-up date and summer greenness of the Tibetan Plateau.

PubMed

Shen, Miaogen; Piao, Shilong; Chen, Xiaoqiu; An, Shuai; Fu, Yongshuo H; Wang, Shiping; Cong, Nan; Janssens, Ivan A

2016-09-01

Understanding vegetation responses to climate change on the Tibetan Plateau (TP) helps in elucidating the land-atmosphere energy exchange, which affects air mass movement over and around the TP. Although the TP is one of the world's most sensitive regions in terms of climatic warming, little is known about how the vegetation responds. Here, we focus on how spring phenology and summertime greenness respond to the asymmetric warming, that is, stronger warming during nighttime than during daytime. Using both in situ and satellite observations, we found that vegetation green-up date showed a stronger negative partial correlation with daily minimum temperature (Tmin ) than with maximum temperature (Tmax ) before the growing season ('preseason' henceforth). Summer vegetation greenness was strongly positively correlated with summer Tmin , but negatively with Tmax . A 1-K increase in preseason Tmin advanced green-up date by 4 days (P < 0.05) and in summer enhanced greenness by 3.6% relative to the mean greenness during 2000-2004 (P < 0.01). In contrast, increases in preseason Tmax did not advance green-up date (P > 0.10) and higher summer Tmax even reduced greenness by 2.6% K(-1) (P < 0.05). The stimulating effects of increasing Tmin were likely caused by reduced low temperature constraints, and the apparent negative effects of higher Tmax on greenness were probably due to the accompanying decline in water availability. The dominant enhancing effect of nighttime warming indicates that climatic warming will probably have stronger impact on TP ecosystems than on apparently similar Arctic ecosystems where vegetation is controlled mainly by Tmax . Our results are crucial for future improvements of dynamic vegetation models embedded in the Earth System Models which are being used to describe the behavior of the Asian monsoon. The results are significant because the state of the vegetation on the TP plays an important role in steering the monsoon. © 2016 John Wiley & Sons Ltd.

How Close Are We to the Temperature Tipping Point of the Biosphere?

NASA Astrophysics Data System (ADS)

Duffy, K. H.

2017-12-01

All biological processes accelerate rapidly with increasing temperature (Tinf); reaching a maximum rate (Tmax), after which they decline. However different biological processes may not be synchronised in their response to increasing temperatures resulting in major dis-equilibria of ecosystem processes. Particularly, the linked processes of photosynthesis and respiration have different curvature that is determined by their inherent sensitivity to temperature. Constraining the difference in temperature curves between photosynthesis and respiration allows us to quantify changes to global carbon metabolism and the land sink of carbon as a whole. During the last century the biosphere has acted as a sink of carbon from the atmosphere partly mitigating accumulation of CO2 derived from burning of fossil fuels Here we ask the following questions: As global temperature increases will photosynthesis and respiration become de-coupled and when? What is Tmax for the land sink, and where is current mean temperature range in regard to this important threshold? At what global and regional temperatures do we expect the biosphere to become a source of carbon to the atmosphere? To address these questions we used the recently released FLUXNET2015 dataset comprised of 212 eddy covariance flux tower sites which concurrently measure land-atmosphere carbon exchange along with micro-meteorological variables. Here, we illustrate our results for Tinf and Tmax of the land sink by biome and for the biosphere as a whole. Our results suggest that recent warming has already pushed us past the inflection point of photosynthesis, and that any additional warming will increase the cumulative annual dose of time spent past Tmax for the land sink. Even under moderate climate projections, we expect to see a slowing of the terrestrial carbon sink by as early as 2040.

Inventory of File nam.t00z.smartconus03.tm00.grib2

Science.gov Websites

Temperature [K] 002 surface DPT 3 hour fcst Dew Point Temperature [K] 003 surface SPFH 3 hour fcst Specific Temperature [K] 026 surface TMP 1 hour fcst Temperature [K] 027 surface DPT 2 hour fcst Dew Point Temperature [K] 028 surface DPT 1 hour fcst Dew Point Temperature [K] 029 surface TMAX 0-3 hour acc Maximum

Impacts of Initial Soil Moisture and Vegetation on the Diurnal Temperature Range in Arid and Semiarid Regions in China

NASA Astrophysics Data System (ADS)

Yuan, Guanghui; Zhang, Lei; Liang, Jiening; Cao, Xianjie; Guo, Qi; Yang, Zhaohong

2017-11-01

To assess the impacts of initial soil moisture (SMOIS) and the vegetation fraction (Fg) on the diurnal temperature range (DTR) in arid and semiarid regions in China, three simulations using the weather research and forecasting (WRF) model are conducted by modifying the SMOIS, surface emissivity and Fg. SMOIS affects the daily maximum temperature (Tmax) and daily minimum temperature (Tmin) by altering the distribution of available energy between sensible and latent heat fluxes during the day and by altering the surface emissivity at night. Reduced soil wetness can increase both the Tmax and Tmin, but the effect on the DTR is determined by the relative strength of the effects on Tmax and Tmin. Observational data from the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) and the Shapotou Desert Research and Experimental Station (SPD) suggest that the magnitude of the SMOIS effect on the distribution of available energy during the day is larger than that on surface emissivity at night. In other words, SMOIS has a negative effect on the DTR. Changes in Fg modify the surface radiation and the energy budget. Due to the depth of the daytime convective boundary layer, the temperature in daytime is affected less than in nighttime by the radiation and energy budget. Increases in surface emissivity and decreases in soil heating resulting from increased Fg mainly decrease Tmin, thereby increasing the DTR. The effects of SMOIS and Fg on both Tmax and Tmin are the same, but the effects on DTR are the opposite.

A remarkable climate warming hiatus over Northeast China since 1998

NASA Astrophysics Data System (ADS)

Sun, Xiubao; Ren, Guoyu; Ren, Yuyu; Fang, Yihe; Liu, Yulian; Xue, Xiaoying; Zhang, Panfeng

2017-07-01

Characteristics and causes of global warming hiatus (GWH) phenomenon have received much attention in recent years. Monthly mean data of land surface air maximum temperature (Tmax), minimum temperature (Tmin), and mean temperature (Tmean) of 118 national stations since 1951 in Northeast China are used in this paper to analyze the changes of land surface air temperature in recent 64 years with an emphasis on the GWH period. The results show that (1) from 1951 to 2014, the warming trends of Tmax, Tmin, and Tmean are 0.20, 0.42, and 0.34 °C/decade respectively for the whole area, with the warming rate of Tmin about two times of Tmax, and the upward trend of Tmean obviously higher than mainland China and global averages; (2) in the period 1998-2014, the annual mean temperature consistently exhibits a cooling phenomenon in Northeast China, and the trends of Tmax, Tmin, and Tmean are -0.36, -0.14, and -0.28 °C/decade respectively; (3) in the GWH period, seasonal mean cooling mainly occurs in northern winter (DJF) and spring (MAM), but northern summer (JJA) and autumn (SON) still experience a warming, implying that the annual mean temperature decrease is controlled by the remarkable cooling of winter and spring; (4) compared to the global and mainland China averages, the hiatus phenomenon is more evident in Northeast China, and the cooling trends are more obvious in the cold season; (5) the Northeast China cooling trend occurs under the circulation background of the negative phase Arctic Oscillation (AO), and it is also closely related to strengthening of the Siberia High (SH) and the East Asian Trough (EAT), and the stronger East Asian winter monsoon (EAWM) over the GWH period.

Inconsistent Responses of Hot Extremes to Historical Land Use and Cover Change Among the Selected CMIP5 Models

NASA Astrophysics Data System (ADS)

Li, Xing; Chen, Haishan; Wei, Jiangfeng; Hua, Wenjian; Sun, Shanlei; Ma, Hedi; Li, Xiao; Li, Jingping

2018-04-01

Land use and cover change (LUCC) is an important anthropogenic forcing of the climate system. Previous studies have demonstrated that LUCC significantly impacts both mean and extreme temperatures. In this study, we explored the multimodel performance of simulating LUCC-induced asymmetric effects on the different percentiles of maximum temperatures (Tmax) as well as the possible reasons for these effects using results from the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Four state-of-art Earth system models (which provide the necessary data) are selected for investigating this issue. In general, all the cases of the model from the Geophysical Fluid Dynamics Laboratory show robust asymmetric responses between the 90th (TX90P) and 10th percentiles (TX10P) of Tmax, mainly due to cropland expansions, especially over India, the Sahel, and some parts of North America. However, weak and insignificant responses are shown for both the TX90P and TX10P in other models. The different changes in the Tmax variability among the models are primarily responsible for the occurrence of asymmetric features. Furthermore, by decomposing the Tmax changes over three typical regions, we analyze the potential causes for the inconsistencies among these models' results and find two crucial processes, that is, the repartitioning of the turbulent heat fluxes and the changes of the diurnal cycle variability due to LUCC. Whether these processes are pronounced determines the occurrence of the asymmetric Tmax responses. Overall, this study provides a critical clue for reducing the uncertainties of the LUCC effects on temperature extremes, which should be evaluated against observations.

The effect of length and starting year on trend analyses of temperatures in Spanish mainland (1951-2010). Seasonal analyses: Autumn (V)

NASA Astrophysics Data System (ADS)

Salinas Solé, Celia; Peña Angulo, Dhais; Gonzalez HIgaldo, Jose Carlos; Brunetti, MIchele

2017-04-01

In this poster we applied the moving window approach (see Poster I of this collection) to analyze trends of autumn and its corresponding months (September, October, November) temperature mean values of maximum (Tmax) and minimum (Tmin) in Spanish mainland to detect the effects of length period and starting year. Monthly series belong to Monthly Temperature dataset of Spanish mainland (MOTEDAS). Database contains in its grid format of 5236 pixels of monthly series (10x10 km). The threshold used in spatial analyses considers 20% of land under significant trend (p<0.05). The most striking results are as follow: • Seasonal trend analyses of Autumn Tmax show no significance at any temporal Windows. Trends of Tmin are significant in more than 20% of land until 1974-2010. The area affected in Tmin progressively increase from SE to NW. • Monthly trend analyses not detect any significance in Tmax, while in Tmin, particularly in October, an extended area is detected in temporal windows in between 1951-2010 to 1978-2010, but clearly concentrated in the starting years of initial 70´s. Spatial pattern of areas affected significantly seems to be from SE to NW for October, and South-North in September. To conclude autumn trend analyses of Tmax and Tmin in Spanish mainland only detect significant trend in Tmin, mostly located in the 70´s and extending from SE to central areas of study area.

Heat waves in Senegal : detection, characterization and associated processes.

NASA Astrophysics Data System (ADS)

Gnacoussa Sambou, Marie Jeanne; Janicot, Serge; Badiane, Daouda; Pohl, Benjamin; Dieng, Abdou L.; Gaye, Amadou T.

2017-04-01

Atmospheric configuration and synoptic evolution of patterns associated with Senegalese heat wave (HW) are examined on the period 1979-2014 using the Global Surface Summary of the Day (GSOD) observational database and ERA-Interim reanalysis. Since there is no objective and uniform definition of HW events, threshold methods based on atmospheric variables as daily maximum (Tmax) / minimum (Tmin) temperatures and daily mean apparent temperature (AT) are used to define HW threshold detection. Each criterion is related to a specific category of HW events: Tmax (warm day events), Tmin (warm night events) and AT (combining temperature and moisture). These definitions are used in order to characterize as well as possible the warm events over the Senegalese regions (oceanic versus continental region). Statistics on time evolution and spatial distribution of warm events are carried out over the 2 seasons of maximum temperature (March-May and October-November). For each season, a composite of HW events, as well as the most extended event over Senegal (as a case study) are analyzed using usual atmospheric fields (sea level pressure, geopotential height, total column water content, wind components, 2m temperature). This study is part of the project ACASIS (https://acasis.locean-ipsl.upmc.fr/doku.php) on heat waves occurrences over the Sahel and their impact on health. Keywords: heat wave, Senegal, ACASIS.

The effect of length and starting year on trend analyses of temperatures in Spanish mainland (1951-2010). Seasonal analysis: Winter (II)

NASA Astrophysics Data System (ADS)

Salinas Solé, Celia; Peña Angulo, Dhais; Gonzalez Hidalgo, Jose Carlos; Brunetti, Michele

2017-04-01

In this poster we applied the moving window approach (see Poster I of this collection) to analyze trends of winter and its corresponding months (December, January, February) temperature mean values of maximum (Tmax) and minimum (Tmin) in Spanish mainland to detect the effects of length period and starting year. Monthly series belong to Monthly Temperature dataset of Spanish mainland (MOTEDAS). Database contains in its grid format of 5236 pixels of monthly series (10x10 km). The threshold used in spatial analyses considers 20% of land under significant trend (p<0.05). The most striking results are as follow: • Seasonal trend analyses of Tmax shows that global trend 1951-2010 was positive and significant mostly in central-western areas; from 1970 to 2010 there is less than 20% of land with significant trend. In the case of Tmin no relevant significant period is detected. • Monthly Tmax analyses show that December significant trend changed from positive (>20%) in between 1955-2010 until 1962-2010, to negative from 1976-2010. Meanwhile January does not show relevant period with significant trend; finally Tmax in February shows different periods with positive significant trend (>20% of land) 1951-2010 to 1954-2010 and 1962-2010 to 1968-2010. No significant trend is detected after this data. • Monthly Tmin trend analyses show that except exceptional period, no months present any significant trend. As conclusions, we have detected that for winter and winter-months, Tmax trends are not significant from 1970 across Spanish mainland. In the case of Tmin we conclude that no significant trend have been occurred in any temporal windows analyzed. Results differ from what traditionally has been assumed that the increase of the average annual temperature was due to the increase of trends in the winter season. And these analyses also show that seasonal trend values could hide monthly behavior. So extreme caution should be taken into account when seasonal values are offered.

Skin temperature evaluation by infrared thermography: Comparison of two image analysis methods during the nonsteady state induced by physical exercise

NASA Astrophysics Data System (ADS)

Formenti, Damiano; Ludwig, Nicola; Rossi, Alessio; Trecroci, Athos; Alberti, Giampietro; Gargano, Marco; Merla, Arcangelo; Ammer, Kurt; Caumo, Andrea

2017-03-01

The most common method to derive a temperature value from a thermal image in humans is the calculation of the average of the temperature values of all the pixels confined within a demarcated boundary defined region of interest (ROI). Such summary measure of skin temperature is denoted as Troi in this study. Recently, an alternative method for the derivation of skin temperature from the thermal image has been developed. Such novel method (denoted as Tmax) is based on an automated (software-driven) selection of the warmest pixels within the ROI. Troi and Tmax have been compared under basal, steady-state conditions, resulting very well correlated and characterized by a bias of approximately 1 °C (Tmax > Troi). Aim of this study was to investigate the relationship between Tmax and Troi under the nonsteady-state conditions induced by physical exercise. Thermal images of quadriceps of 13 subjects performing a squat exercise were recorded for 120 s before (basal steady state) and for 480 s after the initiation of the exercise (nonsteady state). The thermal images were then analysed to extract Troi and Tmax. Troi and Tmax changed almost in parallel during the nonstead -state. At a closer inspection, it was found that during the nonsteady state the bias between the two methods slightly increased (from 0.7 to 1.1 °C) and the degree of association between them slightly decreased (from Pearson's r = 0.96 to 0.83). Troi and Tmax had different relationships with the skin temperature histogram. Whereas Tmax was the mean, which could be interpreted as the centre of gravity of the histogram, Tmax was related with the extreme upper tail of the histogram. During the nonsteady state, the histogram increased its spread and became slightly more asymmetric. As a result, Troi deviated a little from the 50th percentile, while Tmax remained constantly higher than the 95th percentile. Despite their differences, Troi and Tmax showed a substantial agreement in assessing the changes in skin temperature following physical exercise. Further studies are needed to clarify the relationship existing among Tmax, Troi and cutaneous blood flow during physical exercise.

Pressure-induced itinerant electron metamagnetism in UCo0.995Os0.005Al ferromagnet

NASA Astrophysics Data System (ADS)

Mushnikov, N. V.; Andreev, A. V.; Arnold, Z.

2018-05-01

The effect of external hydrostatic pressure on magnetic properties is studied for the UCo0.995Os0.005Al single crystal. At ambient pressure, the ground state is ferromagnetic. Even lowest applied pressure 0.11 GPa is sufficient to suppress ferromagnetism. A sharp metamagnetic transition is observed only in magnetic fields along the c axis of the crystal, similar to previously studied itinerant electron metamagnet UCoAl. Temperature dependence of the susceptibility for various pressures shows a broad maximum at Tmax 20 K. The experimental data are analyzed with the theory of itinerant electron metamagnetism, which considers anisotropic thermal fluctuations of the uranium magnetic moment. The observed pressure dependence of the susceptibility at Tmax and the temperature for the disappearance of the first-order metamagnetic transition are explained with the theory.

High-frequency daily temperature variability in China and its relationship to large-scale circulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Fu-Ting; Fu, Congbin; Qian, Yun

Two measures of intra-seasonal variability, indicated respectively by standard deviations (SD) and day-to-day (DTD) fluctuations denoted by absolute differences between adjacent 2-day periods, as well as their relationships with large-scale circulation patterns were investigated in China during 1962–2008 on the basis of homogenized daily temperature records from 549 local stations and reanalysis data. Our results show that both the SD and DTD of daily minimum temperatures (Tmin) in summer as well as the minimum and maximum temperatures in winter have been decreasing, while the daily maximum temperature (Tmax) variability in summer is fluctuating more, especially over southern China. In summer,more » an attribution analysis indicates that the intensity of the Western Pacific Subtropical High (WPSH) and high-level East Asian Subtropical Jet stream (EASJ) are positively correlated with both SD and DTD, but the correlation coefficients are generally greater with the SD than with the DTD of the daily maximum temperature, Tmax. In contrast, the location of the EASJ shows the opposite correlation pattern, with intensity regarding the correlation with both SD and DTD. In winter, the Arctic Oscillation (AO) is negatively correlated with both the SD and DTD of the daily minimum temperature, but its intra-seasonal variability exhibits good agreement with the SD of the Tmin. The Siberian High acts differently with respect to the SD and DTD of the Tmin, demonstrating a regionally consistent positive correlation with the SD. Overall, the large-scale circulation can well explain the intra-seasonal SD, but DTD fluctuations may be more local and impacted by local conditions, such as changes in the temperature itself, the land surface, and so on.« less

Return levels of temperature extremes in southern Pakistan

NASA Astrophysics Data System (ADS)

Zahid, Maida; Blender, Richard; Lucarini, Valerio; Caterina Bramati, Maria

2017-12-01

Southern Pakistan (Sindh) is one of the hottest regions in the world and is highly vulnerable to temperature extremes. In order to improve rural and urban planning, it is useful to gather information about the recurrence of temperature extremes. In this work, return levels of the daily maximum temperature Tmax are estimated, as well as the daily maximum wet-bulb temperature TWmax extremes. We adopt the peaks over threshold (POT) method, which has not yet been used for similar studies in this region. Two main datasets are analyzed: temperatures observed at nine meteorological stations in southern Pakistan from 1980 to 2013, and the ERA-Interim (ECMWF reanalysis) data for the nearest corresponding locations. The analysis provides the 2-, 5-, 10-, 25-, 50-, and 100-year return levels (RLs) of temperature extremes. The 90 % quantile is found to be a suitable threshold for all stations. We find that the RLs of the observed Tmax are above 50 °C at northern stations and above 45 °C at the southern stations. The RLs of the observed TWmax exceed 35 °C in the region, which is considered as a limit of survivability. The RLs estimated from the ERA-Interim data are lower by 3 to 5 °C than the RLs assessed for the nine meteorological stations. A simple bias correction applied to ERA-Interim data improves the RLs remarkably, yet discrepancies are still present. The results have potential implications for the risk assessment of extreme temperatures in Sindh.

Attribution of the United States "warming hole": aerosol indirect effect and precipitable water vapor.

PubMed

Yu, Shaocai; Alapaty, Kiran; Mathur, Rohit; Pleim, Jonathan; Zhang, Yuanhang; Nolte, Chris; Eder, Brian; Foley, Kristen; Nagashima, Tatsuya

2014-11-06

Aerosols can influence the climate indirectly by acting as cloud condensation nuclei and/or ice nuclei, thereby modifying cloud optical properties. In contrast to the widespread global warming, the central and south central United States display a noteworthy overall cooling trend during the 20(th) century, with an especially striking cooling trend in summertime daily maximum temperature (Tmax) (termed the U.S. "warming hole"). Here we used observations of temperature, shortwave cloud forcing (SWCF), longwave cloud forcing (LWCF), aerosol optical depth and precipitable water vapor as well as global coupled climate models to explore the attribution of the "warming hole". We find that the observed cooling trend in summer Tmax can be attributed mainly to SWCF due to aerosols with offset from the greenhouse effect of precipitable water vapor. A global coupled climate model reveals that the observed "warming hole" can be produced only when the aerosol fields are simulated with a reasonable degree of accuracy as this is necessary for accurate simulation of SWCF over the region. These results provide compelling evidence of the role of the aerosol indirect effect in cooling regional climate on the Earth. Our results reaffirm that LWCF can warm both winter Tmax and Tmin.

The effect of length and starting year on trend analyses of temperatures in Spanish mainland (1951-2010). Seasonal analyses: Spring (III)

NASA Astrophysics Data System (ADS)

Salinas Solé, Celia; Peña Angulo, Dhais; Gonzalez Hidalgo, Jose Carlos; Brunetti, Michele

2017-04-01

In this poster we applied the moving window approach (see Poster I of this collection) to analyze trends of spring and its corresponding months (March, April, May) temperature mean values of maximum (Tmax) and minimum (Tmin) in Spanish mainland to detect the effects of length period and starting year. Monthly series belong to Monthly Temperature dataset of Spanish mainland (MOTEDAS). Database contains in its grid format of 5236 pixels of monthly series (10x10 km). The threshold used in spatial analyses considers 20% of land under significant trend (p<0.05). The most striking results are as follow: • Seasonal Tmax shows that global trend was positive and significant until the mid 80's with higher values than 75% from between 1954-2010 to 1979-2010, being reduced after to the north region. So, from 1985-2010 no significant trend have been detected. Monthly analyses show differences. March trend is not significant (<20% of area) since 1974-2010, while significant trend in April and May varies between 1961-2010/1979-2010 and 1965-2010/1980-2010 respectively, clearly located in northern midland and Mediterranean coastland. • Spring Tmin trend analyses is significantly (>20%) during all temporal windows, notwithstanding NW do not show global significant trend, and in the most recent temporal windows only affect significantly SE. Monthly analyses also differ. Not significant trend is detected in March from 1979-2010, and from 1985-2010 in May, being April the month in any temporal windows with more than 20% of land affected by significant trend. • Spatial differences are detected between windows (South-North in March, East-West in April-May. We can conclude Tmax trend varies accordingly temporal windows dramatically in spring and no significance has been detected in the recent decades. Northern areas and Mediterranean coastland seems to be the most affected. Monthy Tmax trend spatial analyses confirm the heterogeneity of diurnal temperatures; different spatial gradients in windows have been detected between months. Seasonal Tmin show a more global temporal pattern. Spatial gradients of significance between months have been detected, in some sense contraries to the observed in Tmax.

Does maximum torque mean optimal pullout strength of screws?

PubMed

Tankard, Sara E; Mears, Simon C; Marsland, Daniel; Langdale, Evan R; Belkoff, Stephen M

2013-04-01

To determine the relationship between insertion torque and pullout strength of 3.5-mm-diameter cortical screws in cadaveric humeri with different bone mineral densities (BMDs). Five pairs of human humeri from each of 3 BMD groups (normal, osteopenic, and osteoporotic) were used. Holes were drilled in each humerus, and maximum insertion torque (T(max)) was measured by tightening a screw until stripping occurred. In the remaining holes, screws were tightened to 50%, 70%, or 90% of the T(max). A servohydraulic testing machine pulled each screw out at 1 mm/s while resulting force and axial displacement were recorded at 10 Hz. The authors checked for an effect of insertion torque (percent T(max)) on pullout strength using a general linearized and latent mixed model (Stata10), controlling for cortical thickness and BMD (T-score). Pullout strength for normal and osteoporotic bone was greatest for screws inserted to 50% T(max) and was significantly greater than that at T(max) but not significantly different from that at 70% or 90% T(max). For osteopenic bone, pullout strength was greatest at 70% peak torque, but it was not significantly different from the pullout strength at the 50% or 90% T(max) levels. Tightening screws beyond 50% T(max) does not increase pullout strength of the screw and may place bone at risk for damage that might result in loss of fixation. Even after adjusting for bone thickness and density, there is no clear relationship between pullout strength and screw torque.

A Key Marine Diazotroph in a Changing Ocean: The Interacting Effects of Temperature, CO2 and Light on the Growth of Trichodesmium erythraeum IMS101

PubMed Central

Lawson, Tracy; Geider, Richard J.

2017-01-01

Trichodesmium is a globally important marine diazotroph that accounts for approximately 60 − 80% of marine biological N2 fixation and as such plays a key role in marine N and C cycles. We undertook a comprehensive assessment of how the growth rate of Trichodesmium erythraeum IMS101 was directly affected by the combined interactions of temperature, pCO2 and light intensity. Our key findings were: low pCO2 affected the lower temperature tolerance limit (Tmin) but had no effect on the optimum temperature (Topt) at which growth was maximal or the maximum temperature tolerance limit (Tmax); low pCO2 had a greater effect on the thermal niche width than low-light; the effect of pCO2 on growth rate was more pronounced at suboptimal temperatures than at supraoptimal temperatures; temperature and light had a stronger effect on the photosynthetic efficiency (Fv/Fm) than did CO2; and at Topt, the maximum growth rate increased with increasing CO2, but the initial slope of the growth-irradiance curve was not affected by CO2. In the context of environmental change, our results suggest that the (i) nutrient replete growth rate of Trichodesmium IMS101 would have been severely limited by low pCO2 at the last glacial maximum (LGM), (ii) future increases in pCO2 will increase growth rates in areas where temperature ranges between Tmin to Topt, but will have negligible effect at temperatures between Topt and Tmax, (iii) areal increase of warm surface waters (> 18°C) has allowed the geographic range to increase significantly from the LGM to present and that the range will continue to expand to higher latitudes with continued warming, but (iv) continued global warming may exclude Trichodesmium spp. from some tropical regions by 2100 where temperature exceeds Topt. PMID:28081236

A Key Marine Diazotroph in a Changing Ocean: The Interacting Effects of Temperature, CO2 and Light on the Growth of Trichodesmium erythraeum IMS101.

PubMed

Boatman, Tobias G; Lawson, Tracy; Geider, Richard J

2017-01-01

Trichodesmium is a globally important marine diazotroph that accounts for approximately 60 - 80% of marine biological N2 fixation and as such plays a key role in marine N and C cycles. We undertook a comprehensive assessment of how the growth rate of Trichodesmium erythraeum IMS101 was directly affected by the combined interactions of temperature, pCO2 and light intensity. Our key findings were: low pCO2 affected the lower temperature tolerance limit (Tmin) but had no effect on the optimum temperature (Topt) at which growth was maximal or the maximum temperature tolerance limit (Tmax); low pCO2 had a greater effect on the thermal niche width than low-light; the effect of pCO2 on growth rate was more pronounced at suboptimal temperatures than at supraoptimal temperatures; temperature and light had a stronger effect on the photosynthetic efficiency (Fv/Fm) than did CO2; and at Topt, the maximum growth rate increased with increasing CO2, but the initial slope of the growth-irradiance curve was not affected by CO2. In the context of environmental change, our results suggest that the (i) nutrient replete growth rate of Trichodesmium IMS101 would have been severely limited by low pCO2 at the last glacial maximum (LGM), (ii) future increases in pCO2 will increase growth rates in areas where temperature ranges between Tmin to Topt, but will have negligible effect at temperatures between Topt and Tmax, (iii) areal increase of warm surface waters (> 18°C) has allowed the geographic range to increase significantly from the LGM to present and that the range will continue to expand to higher latitudes with continued warming, but (iv) continued global warming may exclude Trichodesmium spp. from some tropical regions by 2100 where temperature exceeds Topt.

The Impacts of Heating Strategy on Soil Moisture Estimation Using Actively Heated Fiber Optics

PubMed Central

Dong, Jianzhi; Agliata, Rosa; Steele-Dunne, Susan; Hoes, Olivier; Bogaard, Thom; Greco, Roberto; van de Giesen, Nick

2017-01-01

Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature (Tcum), the maximum temperature (Tmax), or the soil thermal conductivity determined from the cooling phase after heating (λ). This study investigates the performance of the Tcum, Tmax and λ methods for different heating strategies, i.e., differences in the duration and input power of the applied heat pulse. The aim is to compare the three approaches and to determine which is best suited to field applications where the power supply is limited. Results show that increasing the input power of the heat pulses makes it easier to differentiate between dry and wet soil conditions, which leads to an improved accuracy. Results suggest that if the power supply is limited, the heating strength is insufficient for the λ method to yield accurate estimates. Generally, the Tcum and Tmax methods have similar accuracy. If the input power is limited, increasing the heat pulse duration can improve the accuracy of the AHFO method for both of these techniques. In particular, extending the heating duration can significantly increase the sensitivity of Tcum to soil moisture. Hence, the Tcum method is recommended when the input power is limited. Finally, results also show that up to 50% of the cable temperature change during the heat pulse can be attributed to soil background temperature, i.e., soil temperature changed by the net solar radiation. A method is proposed to correct this background temperature change. Without correction, soil moisture information can be completely masked by the background temperature error. PMID:28902141

Evaluation of clumped isotope paleotemperatures across carbon isotope excursions from lacustrine strata of the Aptian Xiagou Formation, China

NASA Astrophysics Data System (ADS)

Suarez, M. B.; Gonzalez, L. A.; Ludvigson, G. A.; You, H.

2014-12-01

Carbon cycle perturbations associated with Ocean Anoxic Event 1a have been implicated in global climate and environmental changes in the Early Aptian, in particular evidence for high sea surface temperatures (SST) and carbonate platform drowning. Records of environmental changes in the terrestrial realm remain sparse. This study provides additional data on clumped isotope derived temperatures (T(Δ47)) from lacustrine carbonates of the Xiagou Formation, Gansu Province, China. In addition, Vitrinite reflectance and the Rock-Eval parameter Tmax were used to evaluate the potential for 13C-18O bonds in the carbonates to have experienced reordering. Clumped isotope derived temperatures range from 28.8 °C to 45.9°C. Vitrinite reflectance values range from 0.67 to 0.72 and Tmax ranges from 429 °C to 443 °C. The warmest temperature, derived from a very fine-grained calcareous sandstone, is at the upper limit of known modern Earth surface temperatures, and prompts concern that the T(Δ47) may be shifted to warmer temperatures as a result of burial diagenesis. Vitrinite reflectance and Tmax values indicate the samples have reached early maturity for oil generation (oil window from 60 °C to 150°C), so may have reached the lower end of temperatures for bond reordering to have occurred (~100 °C for ~100 million years). Despite this, the T(Δ47) are consistent with summer temperatures in a warm Cretaceous. In addition, temperature variations are similar to TEX86 records, especially from SST of the tropical Pacific. Two temperature increases and decreases occur, with the first peak in temperature occurring at the negative carbon isotope excursion (C3) associated with the initiation of the Selli Event (OAE1a). This study provides evidence that climate variations occurring during the Selli Event were experienced in terrestrial environments, and provides maximum summer temperatures for this part of the Asian continent during the Cretaceous. While it was intended that thermal maturity parameters such as vitrinite reflectance and Tmax would help to rule out alteration due to burial diagenesis, the results are somewhat ambiguous. More rigorous data will be needed in future studies to screen clumped isotope samples for burial diagenesis.

The relevance of MRI for patient modeling in head and neck hyperthermia treatment planning: a comparison of CT and CT-MRI based tissue segmentation on simulated temperature.

PubMed

Verhaart, René F; Fortunati, Valerio; Verduijn, Gerda M; van der Lugt, Aad; van Walsum, Theo; Veenland, Jifke F; Paulides, Margarethus M

2014-12-01

In current clinical practice, head and neck (H&N) hyperthermia treatment planning (HTP) is solely based on computed tomography (CT) images. Magnetic resonance imaging (MRI) provides superior soft-tissue contrast over CT. The purpose of the authors' study is to investigate the relevance of using MRI in addition to CT for patient modeling in H&N HTP. CT and MRI scans were acquired for 11 patients in an immobilization mask. Three observers manually segmented on CT, MRI T1 weighted (MRI-T1w), and MRI T2 weighted (MRI-T2w) images the following thermo-sensitive tissues: cerebrum, cerebellum, brainstem, myelum, sclera, lens, vitreous humor, and the optical nerve. For these tissues that are used for patient modeling in H&N HTP, the interobserver variation of manual tissue segmentation in CT and MRI was quantified with the mean surface distance (MSD). Next, the authors compared the impact of CT and CT and MRI based patient models on the predicted temperatures. For each tissue, the modality was selected that led to the lowest observer variation and inserted this in the combined CT and MRI based patient model (CT and MRI), after a deformable image registration. In addition, a patient model with a detailed segmentation of brain tissues (including white matter, gray matter, and cerebrospinal fluid) was created (CT and MRIdb). To quantify the relevance of MRI based segmentation for H&N HTP, the authors compared the predicted maximum temperatures in the segmented tissues (Tmax) and the corresponding specific absorption rate (SAR) of the patient models based on (1) CT, (2) CT and MRI, and (3) CT and MRIdb. In MRI, a similar or reduced interobserver variation was found compared to CT (maximum of median MSD in CT: 0.93 mm, MRI-T1w: 0.72 mm, MRI-T2w: 0.66 mm). Only for the optical nerve the interobserver variation is significantly lower in CT compared to MRI (median MSD in CT: 0.58 mm, MRI-T1w: 1.27 mm, MRI-T2w: 1.40 mm). Patient models based on CT (Tmax: 38.0 °C) and CT and MRI (Tmax: 38.1 °C) result in similar simulated temperatures, while CT and MRIdb (Tmax: 38.5 °C) resulted in significantly higher temperatures. The SAR corresponding to these temperatures did not differ significantly. Although MR imaging reduces the interobserver variation in most tissues, it does not affect simulated local tissue temperatures. However, the improved soft-tissue contrast provided by MRI allows generating a detailed brain segmentation, which has a strong impact on the predicted local temperatures and hence may improve simulation guided hyperthermia.

Analysis of trend in temperature and rainfall time series of an Indian arid region: comparative evaluation of salient techniques

NASA Astrophysics Data System (ADS)

Machiwal, Deepesh; Gupta, Ankit; Jha, Madan Kumar; Kamble, Trupti

2018-04-01

This study investigated trends in 35 years (1979-2013) temperature (maximum, Tmax and minimum, Tmin) and rainfall at annual and seasonal (pre-monsoon, monsoon, post-monsoon, and winter) scales for 31 grid points in a coastal arid region of India. Box-whisker plots of annual temperature and rainfall time series depict systematic spatial gradients. Trends were examined by applying eight tests, such as Kendall rank correlation (KRC), Spearman rank order correlation (SROC), Mann-Kendall (MK), four modified MK tests, and innovative trend analysis (ITA). Trend magnitudes were quantified by Sen's slope estimator, and a new method was adopted to assess the significance of linear trends in MK-test statistics. It was found that the significant serial correlation is prominent in the annual and post-monsoon Tmax and Tmin, and pre-monsoon Tmin. The KRC and MK tests yielded similar results in close resemblance with the SROC test. The performance of two modified MK tests considering variance-correction approaches was found superior to the KRC, MK, modified MK with pre-whitening, and ITA tests. The performance of original MK test is poor due to the presence of serial correlation, whereas the ITA method is over-sensitive in identifying trends. Significantly increasing trends are more prominent in Tmin than Tmax. Further, both the annual and monsoon rainfall time series have a significantly increasing trend of 9 mm year-1. The sequential significance of linear trend in MK test-statistics is very strong (R 2 ≥ 0.90) in the annual and pre-monsoon Tmin (90% grid points), and strong (R 2 ≥ 0.75) in monsoon Tmax (68% grid points), monsoon, post-monsoon, and winter Tmin (respectively 65, 55, and 48% grid points), as well as in the annual and monsoon rainfalls (respectively 68 and 61% grid points). Finally, this study recommends use of variance-corrected MK test for the precise identification of trends. It is emphasized that the rising Tmax may hamper crop growth due to enhanced metabolic-activities and shortened crop-duration. Likewise, increased Tmin may result in lesser crop and biomass yields owing to the increased respiration.

Early and late hot extremes, and elongation of the warm period over Greece

NASA Astrophysics Data System (ADS)

Founda, Dimitra; Giannakopoulos, Christos; Pierros, Fragiskos

2017-04-01

The eastern Mediterranean has been assigned as one of the most responsive areas in climate change, mainly with respect to the occurrence of warmer and drier conditions. In Greece in particular, observations suggest prominent increases in the summer air temperature which in some areas amount to approximately 1 0C/decade since the mid 1970s, while Regional Climate Models simulate further increases in the near and distant future. These changes are coupled with simultaneous increase in the occurrence of hot extremes. In addition to changes in the frequency and intensity of hot extrems, timing of occurrence is also of special interest. Early heat waves in particular, have been found to increase thermal risk in humans. The study explores variations and trends in timing, namely the date of first and last occurrence of hot extremes within the year, and subsequently the hot extremes period (season), defined as the time interval (number of days) between first and last hot extremes occurrence, over Greece. A case study for the area of Athens covering a longer than 100-years period (1897-2015) was conducted first, which will be extended to other Greek areas. Several heat related climatic indices were used, based either on predefined temperature thresholds such as 'tropical days' (daily maximum air temperature, Tmax >30 0C), 'tropical nights' (daily minimum air temperature, Tmin >20 0C), 'hot days' (Tmax >35 0C), or on local climate statistics such as days with Tmax (or Tmin) > 95th percentile. The analysis revealed significant changes in the period of hot extremes and specifically elongation of the period, attributed to early rather than late hot extremes occurrence. An earlier shift of the first tropical day and the first tropical night occurrence by approximately 2 days/decade was found over the study period. An overall elongation of the 'hot days' season by 2.6 days/decade was also observed, which is more prominent since the early 1980s. Over the last three decades, earlier shift of occurrence of days with Tmax > 37 0C and Tmin > 26 0C (corresponding to the 95th percentiles of summer Tmax and Tmin respectively for Athens) was striking, amounting to 8 days/decade. Our findings for the hot extremes period will be used to validate respective simulations of Regional Climate Models downscaled over the areas of interest.

Mortality impact of extreme winter temperatures

NASA Astrophysics Data System (ADS)

Díaz, Julio; García, Ricardo; López, César; Linares, Cristina; Tobías, Aurelio; Prieto, Luis

2005-01-01

During the last few years great attention has been paid to the evaluation of the impact of extreme temperatures on human health. This paper examines the effect of extreme winter temperature on mortality in Madrid for people older than 65, using ARIMA and GAM models. Data correspond to 1,815 winter days over the period 1986 1997, during which time a total of 133,000 deaths occurred. The daily maximum temperature (Tmax) was shown to be the best thermal indicator of the impact of climate on mortality. When total mortality was considered, the maximum impact occured 7 8 days after a temperature extreme; for circulatory diseases the lag was between 7 and 14 days. When respiratory causes were considered, two mortality peaks were evident at 4 5 and 11 days. When the impact of winter extreme temperatures was compared with that associated with summer extremes, it was found to occur over a longer term, and appeared to be more indirect.

Effect of K loadings on nitrate formation/decomposition and on NOx storage performance of K-based NOx storage-reduction catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Do Heui; Mudiyanselage, Kumudu K.; Szanyi, Janos

2013-10-25

We have investigated nitrate formation and decomposition processes, and measured NOx storage performance on Pt-K2O/Al2O3 catalysts as a function of potassium loading. After NO2 adsorption at room temperature, ionic and bidentate nitrates were observed by fourier transform infra-red (FTIR) spectroscopy. The ratio of the former to the latter species increased with increasing potassium loading up to 10 wt%, and then stayed almost constant with additional K, demonstrating a clear dependence of loading on the morphology of the K species. Although both K2O(10)/Al2O3 and K2O(20)/Al2O3 samples have similar nitrate species after NO2 adsorption, the latter has more thermally stable nitrate speciesmore » as evidenced by FTIR and NO2 temperature programmed desorption (TPD) results. With regard to NOx storage performance, the temperature of maximum NOx uptake (Tmax) is 573 K up to a potassium loading of 10 wt%. As the potassium loading increases from 10 wt% to 20 wt%, Tmax shifted from 573 K to 723 K. Moreover, the amount of NO uptake (38 cm3 NOx/g catal) at Tmax increased more than three times, indicating that efficiency of K in storing NOx is enhanced significantly at higher temperature, in good agreement with the NO2 TPD and FTIR results. Thus, a combination of characterization and NOx storage performance results demonstrates an unexpected effect of potassium loading on nitrate formation and decomposition processes; results important for developing Pt-K2O/Al2O3 for potential applications as high temperature NOx storage-reduction catalysts.« less

Observed warming over northern South America has an anthropogenic origin

NASA Astrophysics Data System (ADS)

Barkhordarian, Armineh; von Storch, Hans; Zorita, Eduardo; Loikith, Paul C.; Mechoso, Carlos R.

2017-10-01

We investigate whether the recently observed trends in daily maximum and minimum near-surface air temperature (Tmax and Tmin, respectively) over South America (SA) are consistent with the simulated response of Tmin and Tmax to anthropogenic forcing. Results indicate that the recently observed warming in the dry seasons is well beyond the range of natural (internal) variability. In the wet season the natural modes of variability explain a substantial portion of Tmin and Tmax variability. We demonstrate that the large-scale component of greenhouse gas (GHG) forcing is detectable in dry-seasonal warming. However, none of the global and regional climate change projections reproduce the observed warming of up to 0.6 K/Decade in Tmax in 1983-2012 over northern SA during the austral spring (SON). Thus, besides the global manifestation of GHG forcing, other external drivers have an imprint. Using aerosols-only forcing simulations, our results provide evidence that anthropogenic aerosols also have a detectable influence in SON and that the indirect effect of aerosols on cloud's lifetime is more compatible with the observed record. In addition, there is an increasing trend in the observed incoming solar radiation over northern SA in SON, which is larger than expected from natural (internal) variability alone. We further show that in the dry seasons the spread of projected trends based on the RCP4.5 scenario derived from 30 CMIP5 models encompasses the observed area-averaged trends in Tmin and Tmax. This may imply that the observed excessive warming in the dry seasons serve as an illustration of plausible future expected change in the region.

Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

NASA Astrophysics Data System (ADS)

Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H. Y.; Fu, B. Q.; Li, M.; Liu, W.

2013-02-01

Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/Tmax) was found and accordingly the activation energy for grain growth in temperature evolution up to Tmax in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads.

Quantifying the relationship between extreme air pollution events and extreme weather events

NASA Astrophysics Data System (ADS)

Zhang, Henian; Wang, Yuhang; Park, Tae-Won; Deng, Yi

2017-05-01

Extreme weather events can strongly affect surface air quality, which has become a major environmental factor to affect human health. Here, we examined the relationship between extreme ozone and PM2.5 (particular matter with an aerodynamic diameter less than 2.5 μm) events and the representative meteorological parameters such as daily maximum temperature (Tmax), minimum relative humidity (RHmin), and minimum wind speed (Vmin), using the location-specific 95th or 5th percentile threshold derived from historical reanalysis data (30 years for ozone and 10 years for PM2.5). We found that ozone and PM2.5 extremes were decreasing over the years, reflecting EPA's tightened standards and effort on reducing the corresponding precursor's emissions. Annual ozone and PM2.5 extreme days were highly correlated with Tmax and RHmin, especially in the eastern U.S. They were positively (negatively) correlated with Vmin in urban (rural and suburban) stations. The overlapping ratios of ozone extreme days with Tmax were fairly constant, about 32%, and tended to be high in fall and low in winter. Ozone extreme days were most sensitive to Tmax, then RHmin, and least sensitive to Vmin. The majority of ozone extremes occurred when Tmax was between 300 K and 320 K, RHmin was less than 40%, and Vmin was less than 3 m/s. The number of annual extreme PM2.5 days was highly positively correlated with the extreme RHmin/Tmax days, with correlation coefficient between PM2.5/RHmin highest in urban and suburban regions and the correlation coefficient between PM2.5/Tmax highest in rural area. Tmax has more impact on PM2.5 extreme over the eastern U.S. Extreme PM2.5 days were more likely to occur at low RH conditions in the central and southeastern U.S., especially during spring time, and at high RH conditions in the northern U.S. and the Great Plains. Most extreme PM2.5 events occurred when Tmax was between 300 K and 320 K and RHmin was between 10% and 50%. Extreme PM2.5 days usually occurred when Vmin was under 2 m/s. However, during spring season in the Southeast and fall season in Northwest, high winds were found to accompany extreme PM2.5 days, likely reflecting the impact of fire emissions.

Effect of screw torque level on cortical bone pullout strength.

PubMed

Cleek, Tammy M; Reynolds, Karen J; Hearn, Trevor C

2007-02-01

The objectives of this study were 2-fold: (1) to perform detailed analysis of cortical screw tightening stiffness during automated insertion, and (2) to determine the effect of 3 torque levels on the holding strength of the bone surrounding the screw threads as assessed by screw pullout. Ten pairs of ovine tibiae were used with 3 test sites spaced 20 mm apart centered along the shaft. One side of each pair was used for measuring ultimate failure torque (Tmax). These Tmax and bone-density values were used to predict Tmax at contralateral tibia sites. Screws were inserted and tightened to 50%, 70%, and 90% of predicted Tmax at the contralateral sites to encompass the average clinical level of torque (86% Tmax). Pullout tests were performed and maximum force values were normalized by cortical thickness. Torque to failure tests indicated tightening to 86% Tmax occurs after yield and leads to an average 51% loss in stiffness. Normalized pullout strength for screws tightened to 50% Tmax, 70% Tmax, and 90% Tmax were 2525 +/- 244, 2707 +/- 280, and 2344 +/- 346 N, respectively, with a significant difference between 70% Tmax and 90% Tmax groups (P < 0.05). Within the limitations of our study involving the testing of 1 type of screw purchase in ovine tibiae, results demonstrate that clinical levels of lag screw tightening (86% Tmax) are past the yield point of bone. Tightening to these high torque levels can cause damage leading to compromised holding strength. Further research is still required to establish the appropriate level of torque required for achieving optimal fracture fixation and healing.

The effect of hot days on occupational heat stress in the manufacturing industry: implications for workers' well-being and productivity

NASA Astrophysics Data System (ADS)

Pogačar, Tjaša; Casanueva, Ana; Kozjek, Katja; Ciuha, Urša; Mekjavić, Igor B.; Kajfež Bogataj, Lučka; Črepinšek, Zalika

2018-03-01

Climate change is expected to exacerbate heat stress at the workplace in temperate regions, such as Slovenia. It is therefore of paramount importance to study present and future summer heat conditions and analyze the impact of heat on workers. A set of climate indices based on summer mean (Tmean) and maximum (Tmax) air temperatures, such as the number of hot days (HD: Tmax above 30 °C), and Wet Bulb Globe Temperature (WBGT) were used to account for heat conditions in Slovenia at six locations in the period 1981-2010. Observed trends (1961-2011) of Tmean and Tmax in July were positive, being larger in the eastern part of the country. Climate change projections showed an increase up to 4.5 °C for mean temperature and 35 days for HD by the end of the twenty-first century under the high emission scenario. The increase in WBGT was smaller, although sufficiently high to increase the frequency of days with a high risk of heat stress up to an average of a third of the summer days. A case study performed at a Slovenian automobile parts manufacturing plant revealed non-optimal working conditions during summer 2016 (WBGT mainly between 20 and 25 °C). A survey conducted on 400 workers revealed that 96% perceived the temperature conditions as unsuitable, and 56% experienced headaches and fatigue. Given these conditions and climate change projections, the escalating problem of heat is worrisome. The European Commission initiated a program of research within the Horizon 2020 program to develop a heat warning system for European workers and employers, which will incorporate case-specific solutions to mitigate heat stress.

The effect of hot days on occupational heat stress in the manufacturing industry: implications for workers' well-being and productivity.

PubMed

Pogačar, Tjaša; Casanueva, Ana; Kozjek, Katja; Ciuha, Urša; Mekjavić, Igor B; Kajfež Bogataj, Lučka; Črepinšek, Zalika

2018-03-30

Climate change is expected to exacerbate heat stress at the workplace in temperate regions, such as Slovenia. It is therefore of paramount importance to study present and future summer heat conditions and analyze the impact of heat on workers. A set of climate indices based on summer mean (Tmean) and maximum (Tmax) air temperatures, such as the number of hot days (HD: Tmax above 30 °C), and Wet Bulb Globe Temperature (WBGT) were used to account for heat conditions in Slovenia at six locations in the period 1981-2010. Observed trends (1961-2011) of Tmean and Tmax in July were positive, being larger in the eastern part of the country. Climate change projections showed an increase up to 4.5 °C for mean temperature and 35 days for HD by the end of the twenty-first century under the high emission scenario. The increase in WBGT was smaller, although sufficiently high to increase the frequency of days with a high risk of heat stress up to an average of a third of the summer days. A case study performed at a Slovenian automobile parts manufacturing plant revealed non-optimal working conditions during summer 2016 (WBGT mainly between 20 and 25 °C). A survey conducted on 400 workers revealed that 96% perceived the temperature conditions as unsuitable, and 56% experienced headaches and fatigue. Given these conditions and climate change projections, the escalating problem of heat is worrisome. The European Commission initiated a program of research within the Horizon 2020 program to develop a heat warning system for European workers and employers, which will incorporate case-specific solutions to mitigate heat stress.

Field-acclimated Gossypium hirsutum cultivars exhibit genotypic and seasonal differences in photosystem II thermostability.

PubMed

Snider, John L; Oosterhuis, Derrick M; Collins, Guy D; Pilon, Cristiane; Fitzsimons, Toby R

2013-03-15

Previous investigations have demonstrated that photosystem II (PSII) thermostability acclimates to prior exposure to heat and drought, but contrasting results have been reported for cotton (Gossypium hirsutum). We hypothesized that PSII thermotolerance in G. hirsutum would acclimate to environmental conditions during the growing season and that there would be differences in PSII thermotolerance between commercially-available U.S. cultivars. To this end, three cotton cultivars were grown under dryland conditions in Tifton Georgia, and two under irrigated conditions in Marianna Arkansas. At Tifton, measurements included PSII thermotolerance (T15, the temperature causing a 15% decline in maximum quantum yield), leaf temperatures, air temperatures, midday (1200 to 1400h) leaf water potentials (ΨMD), leaf-air vapor pressure deficit (VPD), actual quantum yield (ΦPSII) and electron transport rate through PSII (ETR) on three sample dates. At Marianna, T15 was measured on two sample dates. Optimal air and leaf temperatures were observed on all sample dates in Tifton, but PSII thermotolerance increased with water deficit conditions (ΨMD=-3.1MPa), and ETR was either unaffected or increased under water-stress. Additionally, T15 for PHY 499 was ∼5°C higher than for the other cultivars examined (DP 0912 and DP 1050). The Marianna site experienced more extreme high temperature conditions (20-30 days Tmax≥35°C), and showed an increase in T15 with higher average Tmax. When average T15 values for each location and sample date were plotted versus average daily Tmax, strong, positive relationships (r(2) from .954 to .714) were observed between Tmax and T15. For all locations T15 was substantially higher than actual field temperature conditions. We conclude that PSII thermostability in G. hirsutum acclimates to pre-existing environmental conditions; PSII is extremely tolerant to high temperature and water-deficit stress; and differences in PSII thermotolerance exist between commercially-available cultivars. Copyright © 2012 Elsevier GmbH. All rights reserved.

Cold denaturation and 2H2O stabilization of a staphylococcal nuclease mutant.

PubMed Central

Antonino, L C; Kautz, R A; Nakano, T; Fox, R O; Fink, A L

1991-01-01

Cold denaturation is now recognized as a general property of proteins but has been observed only under destabilizing conditions, such as moderate denaturant concentration or low pH. By destabilizing the protein using site-directed mutagenesis, we have observed cold denaturation at pH 7.0 in the absence of denaturants in a mutant of staphylococcal nuclease, which we call NCA S28G for a hybrid protein between staphylococcal nuclease and concanavalin A in which there is the point mutation Ser-28----Gly. The temperature of maximum stability (tmax) as determined by circular dichroism (CD) was 18.1 degrees C, and the midpoints of the thermal unfolding transitions (tm) were 0.6 degrees C and 30.0 degrees C. These values may be compared with the tm of 52.5 degrees C for wild-type staphylococcal nuclease, for which no cold denaturation was observed under these conditions. When the stability of the mutant was examined in 2H2O by NMR, CD, or fluorescence, a substantial increase in the amount of folded protein at the tmax was noted as well as a decrease in tmax, reflecting increased stability. PMID:1652762

Evaluating the predictive performance of empirical estimators of natural mortality rate using information on over 200 fish species

USGS Publications Warehouse

Then, Amy Y.; Hoenig, John M; Hall, Norman G.; Hewitt, David A.

2015-01-01

Many methods have been developed in the last 70 years to predict the natural mortality rate, M, of a stock based on empirical evidence from comparative life history studies. These indirect or empirical methods are used in most stock assessments to (i) obtain estimates of M in the absence of direct information, (ii) check on the reasonableness of a direct estimate of M, (iii) examine the range of plausible M estimates for the stock under consideration, and (iv) define prior distributions for Bayesian analyses. The two most cited empirical methods have appeared in the literature over 2500 times to date. Despite the importance of these methods, there is no consensus in the literature on how well these methods work in terms of prediction error or how their performance may be ranked. We evaluate estimators based on various combinations of maximum age (tmax), growth parameters, and water temperature by seeing how well they reproduce >200 independent, direct estimates of M. We use tenfold cross-validation to estimate the prediction error of the estimators and to rank their performance. With updated and carefully reviewed data, we conclude that a tmax-based estimator performs the best among all estimators evaluated. The tmax-based estimators in turn perform better than the Alverson–Carney method based on tmax and the von Bertalanffy K coefficient, Pauly’s method based on growth parameters and water temperature and methods based just on K. It is possible to combine two independent methods by computing a weighted mean but the improvement over the tmax-based methods is slight. Based on cross-validation prediction error, model residual patterns, model parsimony, and biological considerations, we recommend the use of a tmax-based estimator (M=4.899tmax−0.916">M=4.899t−0.916maxM=4.899tmax−0.916, prediction error = 0.32) when possible and a growth-based method (M=4.118K0.73L∞−0.33">M=4.118K0.73L−0.33∞M=4.118K0.73L∞−0.33 , prediction error = 0.6, length in cm) otherwise.

Exploring the association between heat and mortality in Switzerland between 1995 and 2013.

PubMed

Ragettli, Martina S; Vicedo-Cabrera, Ana M; Schindler, Christian; Röösli, Martin

2017-10-01

Designing effective public health strategies to prevent adverse health effect of hot weather is crucial in the context of global warming. In Switzerland, the 2003 heat have caused an estimated 7% increase in all-cause mortality. As a consequence, the Swiss Federal Office of Public Health developed an information campaign to raise public awareness on heat threats. For a better understanding on how hot weather affects daily mortality in Switzerland, we assessed the effect of heat on daily mortality in eight Swiss cities and population subgroups from 1995 to 2013 using different temperature metrics (daily mean (Tmean), maximum (Tmax), minimum (Tmin) and maximum apparent temperature (Tappmax)), and aimed to evaluate variations of the heat effect after 2003 (1995-2002 versus 2004-2013). We applied conditional quasi-Poisson regression models with non-linear distributed lag functions to estimate temperature-mortality associations over all cities (1995-2013) and separately for two time periods (1995-2002, 2004-2013). Relative risks (RR) of daily mortality were estimated for increases in temperature from the median to the 98th percentile of the warm season temperature distribution. Over the whole time period, significant temperature-mortality relationships were found for all temperature indicators (RR (95% confidence interval): Tappmax: 1.12 (1.05; 1.18); Tmax: 1.15 (1.08-1.22); Tmean: 1.16 (1.09-1.23); Tmin 1.23 (1.15-1.32)). Mortality risks were higher at the beginning of the summer, especially for Tmin. In the more recent time period, we observed a non-significant reduction in the effect of high temperatures on mortality, with the age group > 74 years remaining the population at highest risk. High temperatures continue to be a considerable risk factor for human health in Switzerland after 2003. More effective public health measures targeting the elderly should be promoted with increased attention to the first heat events in summer and considering both high day-time and night-time temperatures. Copyright © 2017 Elsevier Inc. All rights reserved.

Impact of Functional Group Modifications on Designer Phenethylamine Induced Hyperthermia.

PubMed

Grecco, Gregory G; Sprague, Jon E

2016-05-16

The popularity of designer phenethylamines such as synthetic cathinones ("bath salts") has led to increased reports of life-threatening hyperthermia. The diversity of chemical modifications has resulted in the toxicological profile of most synthetic cathinones being mostly uncharacterized. Here, we investigated the thermogenic effects of six recently identified designer phenethylamines (4-methylmethamphetamine, methylone, mephedrone, butylone, pentylone, and MDPV) and compared these effects to the established thermogenic agent 3,4-methylenedioxymethamphetamine (MDMA). Specifically, we determined the impact of a β-ketone, α-alkyl, or pyrrolidine functional group on core-body temperature changes. Sprague-Dawley rats (n = 5-6) were administered a dose (30 mg/kg, sc) of a designer phenethylamine or MDMA, and core body temperature measurements were recorded at 30 min intervals for 150 min post treatment. MDMA elicited the greatest maximum temperature change (ΔTmax), and this effect was significantly greater than that of its β-ketone analogue, methylone. Temperature-area under the curves (TAUCs) and ΔTmax were also significantly different between 4-methylmethamphetamine (4-MMA) and its β-ketone analogue mephedrone. Lengthening the α-alkyl chain of methylone to produce butylone and pentylone significantly attenuated the thermogenic response on both TAUCs and ΔTmax compared to those of methylone; however, butylone and pentylone were not different from each other. Pyrrolidine substitution on the N-terminus of pentylone produces 3,4-methylenedioxypyrovalerone (MDPV), which did not significantly alter core body temperature. Thermogenic comparisons of MDMA vs methylone and 4-MMA vs mephedrone indicate that oxidation at the benzylic position significantly attenuates the hyperthermic response. Furthermore, either extending the α-alkyl chain to ethyl and propyl (butylone and pentylone, respectively) or extending the α-alkyl chain and adding a pyrrolidine on the N-terminus (MDPV) significantly blunted the thermogenic effects of methylone. Overall, the present study provides the first structure-activity relationship in vivo toxicological analysis of designer phenethylamines.

Interactions between pre- or postservice climatic factors, parity, and weaning-to-first-mating interval for total number of pigs born of female pigs serviced during hot and humid or cold seasons.

PubMed

Iida, R; Koketsu, Y

2014-09-01

The objective of this study was to examine interactions between climatic factors, parity, and weaning-to-first-mating interval (WMI) for total number of pigs born at subsequent parity (TPB) of female pigs serviced during 2 seasons. The present study analyzed records of 27,739 gilts and 127,670 parity records of sows in 95 Japanese herds; the records included females that were serviced between June and September (hot and humid season) or between December and March (cold season) in 2007 through 2009. The climate data were obtained from 20 weather stations located close to the studied herds. Mean daily maximum temperatures (Tmax), mean daily minimum temperatures (Tmin), and daily average relative humidity (RH) for 21 d preservice and 15 d postservice for each female were coordinated with that female's reproductive data. Linear regression models with random intercept and slopes were applied to the data. Mean TPB (±SEM) was 11.9 ± 0.01 pigs. Mean values (ranges) of Tmax in the hot and humid season and Tmin in the cold season were 28.4 (13.6 to 39.8°C) and 2.0°C (-13.2 to 17.6°C), respectively. Also, mean RH in the hot and humid season and the cold season were 73.2 (35 to 98%) and 65.2% (25 to 99%), respectively. In the hot and humid season, TPB in gilts decreased by 0.05 pigs for each degree Celsius increase in preservice Tmax (P < 0.05). However, there was no association between gilt TPB and either postservice Tmax (P = 0.11) or pre- and postservice RH (P ≥ 0.66). In sows, as preservice Tmax increased from 25 to 30°C, TPB in parity groups 1 and 2 or higher decreased by 0.6 and 0.4 pigs, respectively (P < 0.05). Also, sow TPB decreased by 0.1 to 0.4 pigs as postservice Tmax increased from 25 to 30°C (P < 0.05). In sows with WMI of 0 to 12 d, TPB decreased by 0.2 to 0.5 pigs as pre- or postservice Tmax increased from 25 to 30°C (P < 0.05). However, in sows with WMI of 13 d or more, TPB was not associated with pre- or postservice Tmax (P ≥ 0.10). As preservice Tmax increased from 25 to 30°C, TPB in sows under 81.6% RH (90th percentile) decreased by 0.5 pigs (P < 0.05), whereas TPB in sows under 65.7% RH (10th percentile) decreased by only 0.3 pigs (P < 0.05). Postservice RH in the hot and humid season was not associated with sow TPB (P = 0.18). During the cold season there was no association between TPB and pre- or postservice Tmin (P ≥ 0.09) or RH (P ≥ 0.45). Therefore, we recommend that producers apply cooling management for females during periservice in summer to increase TPB.

Dynamical relationship between wind speed magnitude and meridional temperature contrast: Application to an interannual oscillation in Venusian middle atmosphere GCM

NASA Astrophysics Data System (ADS)

Yamamoto, Masaru; Takahashi, Masaaki

2018-03-01

We derive simple dynamical relationships between wind speed magnitude and meridional temperature contrast. The relationship explains scatter plot distributions of time series of three variables (maximum zonal wind speed UMAX, meridional wind speed VMAX, and equator-pole temperature contrast dTMAX), which are obtained from a Venus general circulation model with equatorial Kelvin-wave forcing. Along with VMAX and dTMAX, UMAX likely increases with the phase velocity and amplitude of a forced wave. In the scatter diagram of UMAX versus dTMAX, points are plotted along a linear equation obtained from a thermal-wind relationship in the cloud layer. In the scatter diagram of VMAX versus UMAX, the apparent slope is somewhat steep in the high UMAX regime, compared with the low UMAX regime. The scatter plot distributions are qualitatively consistent with a quadratic equation obtained from a diagnostic equation of the stream function above the cloud top. The plotted points in the scatter diagrams form a linear cluster for weak wave forcing, whereas they form a small cluster for strong wave forcing. An interannual oscillation of the general circulation forming the linear cluster in the scatter diagram is apparent in the experiment of weak 5.5-day wave forcing. Although a pair of equatorial Kelvin and high-latitude Rossby waves with a same period (Kelvin-Rossby wave) produces equatorward heat and momentum fluxes in the region below 60 km, the equatorial wave does not contribute to the long-period oscillation. The interannual fluctuation of the high-latitude jet core leading to the time variation of UMAX is produced by growth and decay of a polar mixed Rossby-gravity wave with a 14-day period.

MOnthly TEmperature DAtabase of Spain 1951-2010: MOTEDAS. (1) Quality control

NASA Astrophysics Data System (ADS)

Peña-Angulo, Dhais; Cortesi, Nicola; Simolo, Claudia; Stepanek, Peter; Brunetti, Michele; González-Hidalgo, José Carlos

2014-05-01

The HIDROCAES project (Impactos Hidrológicos del Calentamiento Global en España, Spanish Ministery of Research CGL2011-27574-C02-01) is focused on the high resolution in the Spanish continental land of the warming processes during the 1951-2010. To do that the Department of Geography (University of Zaragoza, Spain), the Hydrometeorological Service (Brno Division, Chezck Republic) and the ISAC-CNR (Bologna, Italy) are developing the new dataset MOTEDAS (MOnthly TEmperature DAtabase of Spain), from which we present a collection of poster to show (1) the general structure of dataset and quality control; (2) the analyses of spatial correlation of monthly mean values of maximum (Tmax) and minimum (Tmin temperature; (3) the reconstruction processes of series and high resolution grid developing; (4) the first initial results of trend analyses of annual, seasonal and monthly range mean values. MOTEDAS has been created after exhaustive analyses and quality control of the original digitalized data of the Spanish National Meteorological Agency (Agencia Estatal de Meteorología, AEMET). Quality control was applied without any prior reconstruction, i.e. on original series. Then, from the total amount of series stored at AEMet archives (more than 4680) we selected only those series with at least 10 years of data (i.e. 120 months, 3066 series) to apply a quality control and reconstruction processes (see Poster MOTEDAS 3). Length of series was Tmin, upper and lower thresholds of absolute data, etc), and by comparison with reference series (see Poster MOTEDAS 3, about reconstruction). Anomalous data were considered when difference between Candidate and Reference series were higher than three times the interquartile distance. The total amount of monthly suspicious data recognized and discarded at the end of this analyses was 7832 data for Tmin, and 8063 for Tmax data; they represent less than 0,8% of original total monthly data, for both Tmax and Tmin. No spatial pattern was detected in the suspicious data; month by month Tmin shows maximum detection in summer months, while Tmax does not show any monthly pattern. Secondly, the homogeneity analyses was performed on the list of series free of anomalous data by using an arrays of test (SNHT, Bivariate, T de Student and Pettit) after new reference series calculated with data free of anomalous. The tests were applied at monthly, seasonal and annual scale (i.e. 17 times per method). Statistical inhomogeneity detections were accepted as follows: Three annual detections (monthly, seasonal, annual) must be found in SNHT or Bivariate test. The total amount of detections by the four tests was greater than 5% of the total possible detection per year. Before any correction we examined the Candidate and reference series chart. Proclim and Anclim software were used during all the processes The total amount of series affected by inhomogeneities was 1013 (Tmax) and 1011 (Tmin), i.e. 1/3 of original series was considered as inhomogeneous. We notice that identified inhomogeneous series in Tmax and Tmin usually do not coincide. This apparently small amount of series compared with previous work could be originated because of the mean length of series is around 15-20 years. References. Stepánek P. 2008a. AnClim - software for time series analysis (for Windows 95/NT). Department of Geography, Faculty of Natural Sciences, MU, Brno, 1.47 B. Stepánek P.. 2008b. ProClimDB - Software for Processing Climatological Datasets. CHMI, Regional office, Brno.

Subseasonal climate variability for North Carolina, United States

NASA Astrophysics Data System (ADS)

Sayemuzzaman, Mohammad; Jha, Manoj K.; Mekonnen, Ademe; Schimmel, Keith A.

2014-08-01

Subseasonal trends in climate variability for maximum temperature (Tmax), minimum temperature (Tmin) and precipitation were evaluated for 249 ground-based stations in North Carolina for 1950-2009. The magnitude and significance of the trends at all stations were determined using the non-parametric Theil-Sen Approach (TSA) and the Mann-Kendall (MK) test, respectively. The Sequential Mann-Kendall (SQMK) test was also applied to find the initiation of abrupt trend changes. The lag-1 serial correlation and double mass curve were employed to address the data independency and homogeneity. Using the MK trend test, statistically significant (confidence level ≥ 95% in two-tailed test) decreasing (increasing) trends by 44% (45%) of stations were found in May (June). In general, trends were decreased in Tmax and increased in Tmin data series in subseasonal scale. Using the TSA method, the magnitude of lowest (highest) decreasing (increasing) trend in Tmax is - 0.050 °C/year (+ 0.052 °C/year) in the monthly series for May (March) and for Tmin is - 0.055 °C/year (+ 0.075 °C/year) in February (December). For the precipitation time series using the TSA method, it was found that the highest (lowest) magnitude of 1.00 mm/year (- 1.20 mm/year) is in September (February). The overall trends in precipitation data series were not significant at the 95% confidence level except that 17% of stations were found to have significant (confidence level ≥ 95% in two-tailed test) decreasing trends in February. The statistically significant trend test results were used to develop a spatial distribution of trends: May for Tmax, June for Tmin, and February for precipitation. A correlative analysis of significant temperature and precipitation trend results was examined with respect to large scale circulation modes (North Atlantic Oscillation (NAO) and Southern Oscillation Index (SOI). A negative NAO index (positive-El Niño Southern Oscillation (ENSO) index) was found to be associated with the decreasing precipitation in February during 1960-1980 (2000-2009). The incremental trend in Tmin in the inter-seasonal (April-October) time scale can be associated with the positive NAO index during 1970-2000.

Probes for investigating the effect of magnetic field, field orientation, temperature and strain on the critical current density of anisotropic high-temperature superconducting tapes in a split-pair 15 T horizontal magnet.

PubMed

Sunwong, P; Higgins, J S; Hampshire, D P

2014-06-01

We present the designs of probes for making critical current density (Jc) measurements on anisotropic high-temperature superconducting tapes as a function of field, field orientation, temperature and strain in our 40 mm bore, split-pair 15 T horizontal magnet. Emphasis is placed on the design of three components: the vapour-cooled current leads, the variable temperature enclosure, and the springboard-shaped bending beam sample holder. The vapour-cooled brass critical-current leads used superconducting tapes and in operation ran hot with a duty cycle (D) of ~0.2. This work provides formulae for optimising cryogenic consumption and calculating cryogenic boil-off, associated with current leads used to make J(c) measurements, made by uniformly ramping the current up to a maximum current (I(max)) and then reducing the current very quickly to zero. They include consideration of the effects of duty cycle, static helium boil-off from the magnet and Dewar (b'), and the maximum safe temperature for the critical-current leads (T(max)). Our optimized critical-current leads have a boil-off that is about 30% less than leads optimized for magnet operation at the same maximum current. Numerical calculations show that the optimum cross-sectional area (A) for each current lead can be parameterized by LI(max)/A = [1.46D(-0.18)L(0.4)(T(max) - 300)(0.25D(-0.09)) + 750(b'/I(max))D(10(-3)I(max)-2.87b') × 10⁶ A m⁻¹ where L is the current lead's length and the current lead is operated in liquid helium. An optimum A of 132 mm(2) is obtained when I(max) = 1000 A, T(max) = 400 K, D = 0.2, b' = 0.3 l h(-1) and L = 1.0 m. The optimized helium consumption was found to be 0.7 l h(-1). When the static boil-off is small, optimized leads have a boil-off that can be roughly parameterized by: b/I(max)  ≈ (1.35 × 10(-3))D(0.41) l h(‑1) A(-1). A split-current-lead design is employed to minimize the rotation of the probes during the high current measurements in our high-field horizontal magnet. The variable-temperature system is based on the use of an inverted insulating cup that operates above 4.2 K in liquid helium and above 77.4 K in liquid nitrogen, with a stability of ±80 mK to ±150 mK. Uniaxial strains of -1.4% to 1.0% can be applied to the sample, with a total uncertainty of better than ±0.02%, using a modified bending beam apparatus which includes a copper beryllium springboard-shaped sample holder.

Methodology to predict a maximum follow-up period for breast cancer patients without significantly reducing the chance of detecting a local recurrence

NASA Astrophysics Data System (ADS)

Mould, Richard F.; Asselain, Bernard; DeRycke, Yann

2004-03-01

For breast cancer where the prognosis of early stage disease is very good and even when local recurrences do occur they can present several years after treatment, the hospital resources required for annual follow-up examinations of what can be several hundreds of patients are financially significant. If, therefore, there is some method to estimate a maximum length of follow-up Tmax necessary, then cost savings of physicians' time as well as outpatient workload reductions can be achieved. In modern oncology where expenses continue to increase exponentially due to staff salaries and the expense of chemotherapy drugs and of new treatment and imaging technology, the economic situation can no longer be ignored. The methodology of parametric modelling, based on the lognormal distribution is described, showing that useful estimates for Tmax can be made, by making a trade-off between Tmax and the fraction of patients who will experience a delay in detection of their local recurrence. This trade-off depends on the chosen tail of the lognormal. The methodology is described for stage T1 and T2 breast cancer and it is found that Tmax = 4 years which is a significant reduction on the usual maximum of 10 years of follow-up which is employed by many hospitals for breast cancer patients. The methodology is equally applicable for cancers at other sites where the prognosis is good and some local recurrences may not occur until several years post-treatment.

Evaluations of Some Scheduling Algorithms for Hard Real-Time Systems

DTIC Science & Technology

1990-06-01

construct because the mechanism is a dispatching procedure. Since all nonpreemptive schedules are contained in the set of all preemptive schedules, the...optimal value of Tmax in the preemptive case is at least a lower bound on the optimal Tmax for the nonpreemptive schedules. This principle is the basis...23 b. Nonpreemptable Version .............................................. 24 4. The Minimize Maximum Tardiness with Earliest Start

Increasing synchrony of high temperature and low flow in western North American streams: double trouble for coldwater biota?

USGS Publications Warehouse

Arismendi, Ivan; Safeeq, Mohammad; Johnson, Sherri L.; Dunham, Jason B.; Haggerty, Roy

2013-01-01

Flow and temperature are strongly linked environmental factors driving ecosystem processes in streams. Stream temperature maxima (Tmax_w) and stream flow minima (Qmin) can create periods of stress for aquatic organisms. In mountainous areas, such as western North America, recent shifts toward an earlier spring peak flow and decreases in low flow during summer/fall have been reported. We hypothesized that an earlier peak flow could be shifting the timing of low flow and leading to a decrease in the interval between Tmax_w and Qmin. We also examined if years with extreme low Qmin were associated with years of extreme high Tmax_w. We tested these hypotheses using long32 term data from 22 minimally human-influenced streams for the period 1950-2010. We found trends toward a shorter time lag between Tmax_w and Qmin over time and a strong negative association between their magnitudes. Our findings show that aquatic biota may be increasingly experiencing narrower time windows to recover or adapt between these extreme events of low flow and high temperature. This study highlights the importance of evaluating multiple environmental drivers to better gauge the effects of the recent climate variability in freshwaters.

Year-round breeding equatorial Larks from three climatically-distinct populations do not use rainfall, temperature or invertebrate biomass to time reproduction

PubMed Central

Ndithia, Henry K.; Matson, Kevin D.; Versteegh, Maaike A.; Muchai, Muchane; Tieleman, B. Irene

2017-01-01

Timing of reproduction in birds is important for reproductive success and is known to depend on environmental cues such as day length and food availability. However, in equatorial regions, where day length is nearly constant, other factors such as rainfall and temperature are thought to determine timing of reproduction. Rainfall can vary at small spatial and temporal scales, providing a highly fluctuating and unpredictable environmental cue. In this study we investigated the extent to which spatio-temporal variation in environmental conditions can explain the timing of breeding of Red-capped Lark, Calandrella cinerea, a species that is capable of reproducing during every month of the year in our equatorial east African study locations. For 39 months in three climatically-distinct locations, we monitored nesting activities, sampled ground and flying invertebrates, and quantified rainfall, maximum (Tmax) and minimum (Tmin) temperatures. Among locations we found that lower rainfall and higher temperatures did not coincide with lower invertebrate biomasses and decreased nesting activities, as predicted. Within locations, we found that rainfall, Tmax, and Tmin varied unpredictably among months and years. The only consistent annually recurring observations in all locations were that January and February had low rainfall, high Tmax, and low Tmin. Ground and flying invertebrate biomasses varied unpredictably among months and years, but invertebrates were captured in all months in all locations. Red-capped Larks bred in all calendar months overall but not in every month in every year in every location. Using model selection, we found no clear support for any relationship between the environmental variables and breeding in any of the three locations. Contrary to popular understanding, this study suggests that rainfall and invertebrate biomass as proxy for food do not influence breeding in equatorial Larks. Instead, we propose that factors such as nest predation, female protein reserves, and competition are more important in environments where weather and food meet minimum requirements for breeding during most of the year. PMID:28419105

Mountain Climates on the Move: Implications for Past and Future Vegetation Shifts in the Northeastern United States

NASA Astrophysics Data System (ADS)

Wason, J. W., III; Dovciak, M.; Bevilacqua, E.

2015-12-01

Climate change in the northeastern United States is expected to shift climatic (temperature) envelopes for spruce-fir forests upslope and northward decreasing their area in the region by 2100. Coarse scale landscape models however, may not incorporate heterogeneity in climatic conditions in mountains that can create climatic refugia for species in high-elevation spruce-fir forests. To determine spatial and temporal trends in climate of mountain spruce-fir forests we measured microclimate at 98 forest plots in 2012 and 2013 on 12 mountains in New York, Vermont, New Hampshire, and Maine. By linking regional climate trends with our spatial climate data we calculated elevational shifts in temperature envelopes during the last 50 years. Additionally we linked our spatial dataset to a range of future climate conditions for 2100 based on Representative Concentration Pathways (1 to 5°C warming). We hypothesized that climates have already changed to an extent that spruce-fir forests should begin to respond and that future climate conditions may shift suitable habitat for spruce-fir forests beyond their current range. We found that regional climate change over the last 50 years has resulted in warming of 0.66 and 1.62°C for average annual daily maximum (Tmax) and minimum (Tmin) temperatures in the region. When linked to our spatial microclimate model, this warming results in a 100 (Tmax) and 312m (Tmin) upslope shift in temperature envelopes. Future climate projections suggest that by 2100 Tmax may shift upslope between 152 and 758m for the 1 and 5°C scenarios respectively, while Tmin may shift upslope between 192 and 962m. Spruce-fir forests typically occupy an elevation range of ~500m suggesting that the climate experienced in these forests 50 years ago may not be found within their elevation range by 2100. These results are discussed in the context of responses of tree populations and growth rates observed along the elevation gradients of northeastern United States.

Observational Studies and a Statistical Early Warning of Surface Ozone Pollution in Tangshan, the Largest Heavy Industry City of North China

PubMed Central

Li, Pei; Xin, Jinyuan; Bai, Xiaoping; Wang, Yuesi; Wang, Shigong; Liu, Shixi; Feng, Xiaoxin

2013-01-01

Continuous measurements of surface ozone (O3) and nitrogen oxides (NOX) at an urban site (39°37′N, 118°09′E) in Tangshan, the largest heavy industry city of North China during summertime from 2008 to 2011 are presented. The pollution of O3 was serious in the city. The daily maximum 1 h means (O3_1-hr max) reached 157 ± 55, 161 ± 54, 120 ± 50, and 178 ± 75 μg/m3 corresponding to an excess over the standard rates of 21%, 27%, 10%, and 40% in 2008–2011, respectively. The total oxidant level (OX = O3 + NO2) was high, with seasonal average concentrations up to 100 μg/m3 in summer. The level of OX at a given location was made up of NOX-independent and NOX-dependent contributions. The independent part can be considered as a regional contribution and was about 100 μg/m3 in Tangshan. Statistical early warning analysis revealed that the O3 levels would exceed the standard rate by 50% on the day following a day when the daily average ozone concentration (O3_mean) exceeded 87 μg/m3 and the daily maximum temperature (T_max) exceeded 29 °C. The exceed-standard rate would reach 80% when O3_mean and T_max exceeded 113 μg/m3 and 31 °C. Similarly, the exceed-standard rate would reach 100% when O3_mean and T_max exceeded 127 μg/m3 and 33 °C, respectively. PMID:23485953

Quantification of parameters influencing methane generation due to biodegradation of municipal solid waste in landfills and laboratory experiments.

PubMed

Fei, Xunchang; Zekkos, Dimitrios; Raskin, Lutgarde

2016-09-01

The energy conversion potential of municipal solid waste (MSW) disposed of in landfills remains largely untapped because of the slow and variable rate of biogas generation, delayed and inefficient biogas collection, leakage of biogas, and landfill practices and infrastructure that are not geared toward energy recovery. A database consisting of methane (CH4) generation data, the major constituent of biogas, from 49 laboratory experiments and field monitoring data from 57 landfills was developed. Three CH4 generation parameters, i.e., waste decay rate (k), CH4 generation potential (L0), and time until maximum CH4 generation rate (tmax), were calculated for each dataset using U.S. EPA's Landfill Gas Emission Model (LandGEM). Factors influencing the derived parameters in laboratory experiments and landfills were investigated using multi-linear regression analysis. Total weight of waste (W) was correlated with biodegradation conditions through a ranked classification scheme. k increased with increasing percentage of readily biodegradable waste (Br0 (%)) and waste temperature, and reduced with increasing W, an indicator of less favorable biodegradation conditions. The values of k obtained in the laboratory were commonly significantly higher than those in landfills and those recommended by LandGEM. The mean value of L0 was 98 and 88L CH4/kg waste for laboratory and field studies, respectively, but was significantly affected by waste composition with ranges from 10 to 300L CH4/kg. tmax increased with increasing percentage of biodegradable waste (B0) and W. The values of tmax in landfills were higher than those in laboratory experiments or those based on LandGEM's recommended parameters. Enhancing biodegradation conditions in landfill cells has a greater impact on improving k and tmax than increasing B0. Optimizing the B0 and Br0 values of landfilled waste increases L0 and reduces tmax. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of Water Use Efficiency of Short Rotation Poplar Coppice at Bohemian-Moravian Highlands

NASA Astrophysics Data System (ADS)

Hlaváčová, Marcela; Fischer, Milan; Mani Tripathi, Abhishek; Orság, Matěj; Trnka, Miroslav

2015-04-01

The water availability of the locality constitutes one of the main constraint for short rotation coppices grown on arable land. As a convenient characteristic assessing how the water use is coupled with the biomass yields, so called water use efficiency (WUE) is proposed. One method of water use efficiency determination is presented within this study. The study was carried out at short rotation poplar coppice (poplar clone J-105) at the Test Station Domanínek, Ltd. at Bohemian-Moravian Highlands during the growing season 2013. Diameters at breast height (DBH) were measured for 16 sample trees where sap flow measuring systems (Granier's Thermal Dissipation Probe, TDP) were installed. TDP outputs are expressed as temperature differences (ΔT) between the heated and non-heated probes. Estimation of sap flux density (Fd) by the Granier method relies on the measurement of temperature difference (ΔT). Determination of maximum temperature difference (ΔTmax) is fundamental for sap flux density (Fd) calculation. Although ΔTmax can be theoretically defined as ΔT at Fd = 0, many factors may prevent the occurrence of the zero flow state, such as night-time water movement for new growth (vegetative or reproductive) or water loss from the canopy due to high vapour pressure deficit (VPD). Therefore, the VPD condition was established for determination of ΔTmax. VPD condition was established as follows: VPD reaching values 0.2 at least 6 hours during night (from 21 p. m. to 3 a. m. and when the condition was fullfilled, the value at 3 a. m. was taken) because it is a supposed time after that the tree has no transpiration. The programmable part of Mini 32 software (www.emsbrno.cz) was used for application of the script establishing ΔTmax values under this VPD condition. Nevertheless, another script was applied on ΔT data set to determination of ΔTmax values for every night at 3 a. m. (as this is when ΔT should be at its daily maximum) without VPD condition restriction for comparison of both approaches. Since application of the two mentioned scripts led to two sets of resulting values, calculations of Fd and consequent sap flow values were computed for both variants of ΔTmaxvalues. The sample trees were divided into 3 diameter classes according to DBH values at the beginning of regular measurements (April 24, 2013). Allometry was carried out on February 20, 2014 to calculation of aboveground woody biomass. The input data for calculations of WUE of aboveground woody biomass productivity was biomass increments and monthly totals of sap flow for 16 sample trees. The total WUE for 16 measured trees reached 4.93 g kg-1 (when calculated with data set without VPD condition) and 4.63 g kg-1 (when calculated with data set under VPD condition). This study was funded by project "Building up a multidisciplinary scientific team focused on drought" No. CZ.1.07/2.3.00/20.0248 and LD130030 supporting COST Action ES1106.

Heat-related illness in Washington State agriculture and forestry sectors.

PubMed

Spector, June T; Krenz, Jennifer; Rauser, Edmund; Bonauto, David K

2014-08-01

We sought to describe heat-related illness (HRI) in agriculture and forestry workers in Washington State. Demographic and clinical Washington State Fund workers' compensation agriculture and forestry HRI claims data (1995-2009) and Washington Agriculture Heat Rule citations (2009-2012) were accessed and described. Maximum daily temperature (Tmax) and Heat Index (HImax) were estimated by claim date and location using AgWeatherNet's weather station network. There were 84 Washington State Fund agriculture and forestry HRI claims and 60 Heat Rule citations during the study period. HRI claims and citations were most common in crop production and support subsectors. The mean Tmax (HImax) was 95°F (99°F) for outdoor HRI claims. Potential HRI risk factors and HRI-related injuries were documented for some claims. Agriculture and forestry HRI cases are characterized by potential work-related, environmental, and personal risk factors. Further work is needed to elucidate the relationship between heat exposure and occupational injuries. © 2014 Wiley Periodicals, Inc.

Heat-Related Illness in Washington State Agriculture and Forestry Sectors

PubMed Central

Spector, June T.; Krenz, Jennifer; Rauser, Edmund; Bonauto, David K.

2017-01-01

Background We sought to describe heat-related illness (HRI) in agriculture and forestry workers in Washington State. Methods Demographic and clinical Washington State Fund workers’ compensation agriculture and forestry HRI claims data (1995–2009) and Washington Agriculture Heat Rule citations (2009–2012) were accessed and described. Maximum daily temperature (Tmax) and Heat Index (HImax) were estimated by claim date and location using AgWeatherNet’s weather station network. Results There were 84 Washington State Fund agriculture and forestry HRI claims and 60 Heat Rule citations during the study period. HRI claims and citations were most common in crop production and support subsectors. The mean Tmax (HImax) was 95°F (99°F) for outdoor HRI claims. Potential HRI risk factors and HRI-related injuries were documented for some claims. Conclusions Agriculture and forestry HRI cases are characterized by potential work-related, environmental, and personal risk factors. Further work is needed to elucidate the relationship between heat exposure and occupational injuries. PMID:24953344

Minimally-invasive Ultrasound Devices for Treating Low Back Pain

NASA Astrophysics Data System (ADS)

Nau, William; Diederich, C.; Shu, R.; Kinsey, A.; Lotz, J.; Ferrier, W.; Sutton, J.; Pellegrino, R.

2006-05-01

Catheter-based ultrasound is being investigated for the potential to deliver heat to disc tissue for the treatment of discogenic low back pain. Two ultrasound applicator design configurations were tested: an intradiscal (IDUS) applicator which can be implanted directly within the disc, and an extradiscal (EDUS) applicator which is placed adjacent to the disc. In vitro heating trials were performed in human lumbar cadaveric disc segments instrumented with 24 thermocouples to obtain detailed maps of the temperature distributions. A low temperature elevation heating protocol in which the maximum temperature measured 5 mm away from the applicator is controlled to 52° C for the treatment period, and a high temperature elevation protocol (maximum temperature controlled to >70° C) were evaluated in this study. In vivo experiments were performed in sheep cervical spine using both applicator configurations, and both heating protocols. Steady-state temperature maps, and thermal doses (t43) calculated from the transient temperature data were used to assess regions of thermal damage within the disc. During the in vitro human disc studies using the high temperature protocol, temperatures were maintained at 71.5° ± 0.4°C 5 mm from an IDUS applicator implanted within the annular wall, with a maximum temperature (Tmax) of 78.6°C (t43 > 4.85 × 1010 min) measured 2 mm from the applicator. For the EDUS applicator, the temperature was maintained at 78.7° °C 5 mm from the applicator, with a Tmax of 86.3°C within 1 mm of the applicator surface. In the in vivo sheep studies, steady-state temperatures were maintained at 49.4° ± 0.3°C (t43 = 8.74 × 102 min) and 73.2° ± 0.6°C (t43 = 1.34 × 1010 min) with the IDUS applicator for the low and high temperature protocols, respectively. Using the EDUS applicator, temperatures were maintained at 54.4° ± 3.2°C (t43 = 4.11 × 104 min) and 69.4° ± 2.8°C (t43 = 2.81 × 109 min) for the two protocols. Directional heating was demonstrated with both applicator design configurations. Results from these studies demonstrated the capability to control temperature distributions within targeted regions of the disc using interstitial ultrasound with greater thermal penetration than can be achieved with the RF heating devices currently in clinical use. Thus interstitial ultrasound offers a potential alternative heating modality for the clinical management of low back pain.

Precambrian Surface Temperatures and Molecular Phylogeny

NASA Astrophysics Data System (ADS)

Schwartzman, David; Lineweaver, Charles H.

2004-06-01

The timing of emergence of major organismal groups is consistent with the climatic temperature being equal to their upper temperature limit of growth (T_{max}), implying a temperature constraint on the evolution of each group, with the climatic temperature inferred from the oxygen isotope record of marine cherts. Support for this constraint comes from the correlation of T_{max} with the rRNA molecular phylogenetic distance from the last common ancestor (LCA) for both thermophilic Archaea and Bacteria. In particular, this correlation for hyperthermophilic Archaea suggests a climatic temperature of about 120°C at the time of the LCA, likely in the Hadean.

α-Pinene secondary organic aerosol at low temperature: chemical composition and implications for particle viscosity

NASA Astrophysics Data System (ADS)

Huang, Wei; Saathoff, Harald; Pajunoja, Aki; Shen, Xiaoli; Naumann, Karl-Heinz; Wagner, Robert; Virtanen, Annele; Leisner, Thomas; Mohr, Claudia

2018-02-01

Chemical composition, size distributions, and degree of oligomerization of secondary organic aerosol (SOA) from α-pinene (C10H16) ozonolysis were investigated for low-temperature conditions (223 K). Two types of experiments were performed using two simulation chambers at the Karlsruhe Institute of Technology: the Aerosol Preparation and Characterization (APC) chamber, and the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) chamber. Experiment type 1 simulated SOA formation at upper tropospheric conditions: SOA was generated in the AIDA chamber directly at 223 K at 61 % relative humidity (RH; experiment termed cold humid, CH) and for comparison at 6 % RH (experiment termed cold dry, CD) conditions. Experiment type 2 simulated SOA uplifting: SOA was formed in the APC chamber at room temperature (296 K) and < 1 % RH (experiment termed warm dry, WD) or 21 % RH (experiment termed warm humid, WH) conditions, and then partially transferred to the AIDA chamber kept at 223 K, and 61 % RH (WDtoCH) or 30 % RH (WHtoCH), respectively. Precursor concentrations varied between 0.7 and 2.2 ppm α-pinene, and between 2.3 and 1.8 ppm ozone for type 1 and type 2 experiments, respectively. Among other instrumentation, a chemical ionization mass spectrometer (CIMS) coupled to a filter inlet for gases and aerosols (FIGAERO), deploying I- as reagent ion, was used for SOA chemical composition analysis. For type 1 experiments with lower α-pinene concentrations and cold SOA formation temperature (223 K), smaller particles of 100-300 nm vacuum aerodynamic diameter (dva) and higher mass fractions (> 40 %) of adducts (molecules with more than 10 carbon atoms) of α-pinene oxidation products were observed. For type 2 experiments with higher α-pinene concentrations and warm SOA formation temperature (296 K), larger particles ( ˜ 500 nm dva) with smaller mass fractions of adducts (< 35 %) were produced. We also observed differences (up to 20 °C) in maximum desorption temperature (Tmax) of individual compounds desorbing from the particles deposited on the FIGAERO Teflon filter for different experiments, indicating that Tmax is not purely a function of a compound's vapor pressure or volatility, but is also influenced by diffusion limitations within the particles (particle viscosity), interactions between particles deposited on the filter (particle matrix), and/or particle mass on the filter. Highest Tmax were observed for SOA under dry conditions and with higher adduct mass fraction; lowest Tmax were observed for SOA under humid conditions and with lower adduct mass fraction. The observations indicate that particle viscosity may be influenced by intra- and inter-molecular hydrogen bonding between oligomers, and particle water uptake, even under such low-temperature conditions. Our results suggest that particle physicochemical properties such as viscosity and oligomer content mutually influence each other, and that variation in Tmax of particle desorptions may have implications for particle viscosity and particle matrix effects. The differences in particle physicochemical properties observed between our different experiments demonstrate the importance of taking experimental conditions into consideration when interpreting data from laboratory studies or using them as input in climate models.

Regional climate change study requires new temperature datasets

NASA Astrophysics Data System (ADS)

Wang, K.; Zhou, C.

2016-12-01

Analyses of global mean air temperature (Ta), i. e., NCDC GHCN, GISS, and CRUTEM4, are the fundamental datasets for climate change study and provide key evidence for global warming. All of the global temperature analyses over land are primarily based on meteorological observations of the daily maximum and minimum temperatures (Tmax and Tmin) and their averages (T2) because in most weather stations, the measurements of Tmax and Tmin may be the only choice for a homogenous century-long analysis of mean temperature. Our studies show that these datasets are suitable for long-term global warming studies. However, they may introduce substantial bias in quantifying local and regional warming rates, i.e., with a root mean square error of more than 25% at 5°x 5° grids. From 1973 to 1997, the current datasets tend to significantly underestimate the warming rate over the central U.S. and overestimate the warming rate over the northern high latitudes. Similar results revealed during the period 1998-2013, the warming hiatus period, indicate the use of T2 enlarges the spatial contrast of temperature trends. This because T2 over land only sample air temperature twice daily and cannot accurately reflect land-atmosphere and incoming radiation variations in the temperature diurnal cycle. For better regional climate change detection and attribution, we suggest creating new global mean air temperature datasets based on the recently available high spatiotemporal resolution meteorological observations, i.e., daily four observations weather station since 1960s, These datasets will not only help investigate dynamical processes on temperature variances but also help better evaluate the reanalyzed and modeled simulations of temperature and make some substantial improvements for other related climate variables in models, especially over regional and seasonal aspects.

Regional climate change study requires new temperature datasets

NASA Astrophysics Data System (ADS)

Wang, Kaicun; Zhou, Chunlüe

2017-04-01

Analyses of global mean air temperature (Ta), i. e., NCDC GHCN, GISS, and CRUTEM4, are the fundamental datasets for climate change study and provide key evidence for global warming. All of the global temperature analyses over land are primarily based on meteorological observations of the daily maximum and minimum temperatures (Tmax and Tmin) and their averages (T2) because in most weather stations, the measurements of Tmax and Tmin may be the only choice for a homogenous century-long analysis of mean temperature. Our studies show that these datasets are suitable for long-term global warming studies. However, they may have substantial biases in quantifying local and regional warming rates, i.e., with a root mean square error of more than 25% at 5 degree grids. From 1973 to 1997, the current datasets tend to significantly underestimate the warming rate over the central U.S. and overestimate the warming rate over the northern high latitudes. Similar results revealed during the period 1998-2013, the warming hiatus period, indicate the use of T2 enlarges the spatial contrast of temperature trends. This is because T2 over land only samples air temperature twice daily and cannot accurately reflect land-atmosphere and incoming radiation variations in the temperature diurnal cycle. For better regional climate change detection and attribution, we suggest creating new global mean air temperature datasets based on the recently available high spatiotemporal resolution meteorological observations, i.e., daily four observations weather station since 1960s. These datasets will not only help investigate dynamical processes on temperature variances but also help better evaluate the reanalyzed and modeled simulations of temperature and make some substantial improvements for other related climate variables in models, especially over regional and seasonal aspects.

Fluid inclusion and vitrinite-reflectance geothermometry compared to heat-flow models of maximum paleotemperature next to dikes, western onshore Gippsland Basin, Australia

USGS Publications Warehouse

Barker, C.E.; Bone, Y.; Lewan, M.D.

1999-01-01

Nine basalt dikes, ranging from 6 cm to 40 m thick, intruding the Upper Jurassic-Lower Cretaceous Strzelecki Group, western onshore Gippsland Basin, were used to study maximum temperatures (Tmax) reached next to dikes. Tmax was estimated from fluid inclusion and vitrinitereflectance geothermometry and compared to temperatures calculated using heat-flow models of contact metamorphism. Thermal history reconstruction suggests that at the time of dike intrusion the host rock was at a temperature of 100-135??C. Fracture-bound fluid inclusions in the host rocks next to thin dikes ( 1.5, using a normalized distance ratio used for comparing measurements between dikes regardless of their thickness. In contrast, the pattern seen next to the thin dikes is a relatively narrow zone of elevated Rv-r. Heat-flow modeling, along with whole rock elemental and isotopic data, suggests that the extended zone of elevated Rv-r is caused by a convection cell with local recharge of the hydrothermal fluids. The narrow zone of elevated Rv-r found next to thin dikes is attributed to the rise of the less dense, heated fluids at the dike contact causing a flow of cooler groundwater towards the dike and thereby limiting its heating effects. The lack of extended heating effects suggests that next to thin dikes an incipient convection system may form in which the heated fluid starts to travel upward along the dike but cooling occurs before a complete convection cell can form. Close to the dike contact at X/D 1.5. ?? 1998 Elsevier Science B.V. All rights reserved.

Weather Types, temperature and relief relationship in the Iberian Peninsula: A regional adiabatic processes under directional weather types

NASA Astrophysics Data System (ADS)

Peña Angulo, Dhais; Trigo, Ricardo; Cortesi, Nicola; Gonzalez-Hidalgo, Jose Carlos

2016-04-01

We have analyzed at monthly scale the spatial distribution of Pearson correlation between monthly mean of maximum (Tmax) and minimum (Tmin) temperatures with weather types (WTs) in the Iberian Peninsula (IP), represent them in a high spatial resolution grid (10km x 10km) from MOTEDAS dataset (Gonzalez-Hidalgo et al., 2015a). The WT classification was that developed by Jenkinson and Collison, adapted to the Iberian Peninsula by Trigo and DaCamara, using Sea Level Pressure data from NCAR/NCEP Reanalysis dataset (period 1951-2010). The spatial distribution of Pearson correlations shows a clear zonal gradient in Tmax under the zonal advection produced in westerly (W) and easterly (E) flows, with negative correlation in the coastland where the air mass come from but positive correlation to the inland areas. The same is true under North-West (NW), North-East (NE), South-West (SW) and South-East (SE) WTs. These spatial gradients are coherent with the spatial distribution of the main mountain chain and offer an example of regional adiabatic phenomena that affect the entire IP (Peña-Angulo et al., 2015b). These spatial gradients have not been observed in Tmin. We suggest that Tmin values are less sensitive to changes in Sea Level Pressure and more related to local factors. These directional WT present a monthly frequency over 10 days and could be a valuable tool for downscaling processes. González-Hidalgo J.C., Peña-Angulo D., Brunetti M., Cortesi, C. (2015a): MOTEDAS: a new monthly temperature database for mainland Spain and the trend in temperature (1951-2010). International Journal of Climatology 31, 715-731. DOI: 10.1002/joc.4298 Peña-Angulo, D., Trigo, R., Cortesi, C., González-Hidalgo, J.C. (2015b): The influence of weather types on the monthly average maximum and minimum temperatures in the Iberian Peninsula. Submitted to Hydrology and Earth System Sciences.

Weekly Oscillation of Daily Climatology of Air Temperature: Implication for Anthropogenic Attribution

NASA Astrophysics Data System (ADS)

Jiang, S.; Wang, K.

2016-12-01

During national holiday and weekend, human activity and anthropogenic emission are expected to be much less than those during workday. Therefore, the contrast of environmental factors (i.e., air temperature and air quality) between national holiday (or weekend) and workday has been attributed to anthropogenic impact. For example, daily maximum (Tmax), minimum (Tmin) and mean (Tmean) air temperatures during the Chinese Spring Festival holiday were found to be 0. 6°C less than those of nearby workdays. We evaluated the contrasts using daily meteorological observations collected at 2479 stations in China from 1961 to 2015. The contrasts were evaluated with two methods. The first directly compared air temperatures between Chinese Spring Festival holiday and nearby workdays. The second first composited a daily climatology of air temperatures centered on the first day of Chinese Spring Festival holiday, and the seasonal cycles of air temperatures were then removed using polynomial regressions. The average of the derived daily deviation of air temperatures can be regarded as anthropogenic impact of Chinese Spring Festival holiday. We found that these two methods obtained nearly the same results. However, we found that the so-called anthropogenic impact during Chinese Spring Festival was not unique because the daily deviations of air temperatures had obvious weekly oscillations. The daily deviations of air temperature had periods of 7 days and 9 days, which explain 60% of the variance of daily deviations of Tmax, Tmin, and Tmean. These results indicate that the so-called anthropogenic impacts are primarily caused by natural variability, i.e., weekly oscillations of the air temperatures. This study also has great implication for the studies on weekend effect of the environmental factors.

Daily air temperature interpolated at high spatial resolution over a large mountainous region

USGS Publications Warehouse

Dodson, R.; Marks, D.

1997-01-01

Two methods are investigated for interpolating daily minimum and maximum air temperatures (Tmin and Tmax) at a 1 km spatial resolution over a large mountainous region (830 000 km2) in the U.S. Pacific Northwest. The methods were selected because of their ability to (1) account for the effect of elevation on temperature and (2) efficiently handle large volumes of data. The first method, the neutral stability algorithm (NSA), used the hydrostatic and potential temperature equations to convert measured temperatures and elevations to sea-level potential temperatures. The potential temperatures were spatially interpolated using an inverse-squared-distance algorithm and then mapped to the elevation surface of a digital elevation model (DEM). The second method, linear lapse rate adjustment (LLRA), involved the same basic procedure as the NSA, but used a constant linear lapse rate instead of the potential temperature equation. Cross-validation analyses were performed using the NSA and LLRA methods to interpolate Tmin and Tmax each day for the 1990 water year, and the methods were evaluated based on mean annual interpolation error (IE). The NSA method showed considerable bias for sites associated with vertical extrapolation. A correction based on climate station/grid cell elevation differences was developed and found to successfully remove the bias. The LLRA method was tested using 3 lapse rates, none of which produced a serious extrapolation bias. The bias-adjusted NSA and the 3 LLRA methods produced almost identical levels of accuracy (mean absolute errors between 1.2 and 1.3??C), and produced very similar temperature surfaces based on image difference statistics. In terms of accuracy, speed, and ease of implementation, LLRA was chosen as the best of the methods tested.

An extended linear scaling method for downscaling temperature and its implication in the Jhelum River basin, Pakistan, and India, using CMIP5 GCMs

NASA Astrophysics Data System (ADS)

Mahmood, Rashid; JIA, Shaofeng

2017-11-01

In this study, the linear scaling method used for the downscaling of temperature was extended from monthly scaling factors to daily scaling factors (SFs) to improve the daily variations in the corrected temperature. In the original linear scaling (OLS), mean monthly SFs are used to correct the future data, but mean daily SFs are used to correct the future data in the extended linear scaling (ELS) method. The proposed method was evaluated in the Jhelum River basin for the period 1986-2000, using the observed maximum temperature (Tmax) and minimum temperature (Tmin) of 18 climate stations and the simulated Tmax and Tmin of five global climate models (GCMs) (GFDL-ESM2G, NorESM1-ME, HadGEM2-ES, MIROC5, and CanESM2), and the method was also compared with OLS to observe the improvement. Before the evaluation of ELS, these GCMs were also evaluated using their raw data against the observed data for the same period (1986-2000). Four statistical indicators, i.e., error in mean, error in standard deviation, root mean square error, and correlation coefficient, were used for the evaluation process. The evaluation results with GCMs' raw data showed that GFDL-ESM2G and MIROC5 performed better than other GCMs according to all the indicators but with unsatisfactory results that confine their direct application in the basin. Nevertheless, after the correction with ELS, a noticeable improvement was observed in all the indicators except correlation coefficient because this method only adjusts (corrects) the magnitude. It was also noticed that the daily variations of the observed data were better captured by the corrected data with ELS than OLS. Finally, the ELS method was applied for the downscaling of five GCMs' Tmax and Tmin for the period of 2041-2070 under RCP8.5 in the Jhelum basin. The results showed that the basin would face hotter climate in the future relative to the present climate, which may result in increasing water requirements in public, industrial, and agriculture sectors; change in the hydrological cycle and monsoon pattern; and lack of glaciers in the basin.

Infrared thermography of the udder surface of dairy cattle: characteristics, methods, and correlation with rectal temperature.

PubMed

Metzner, Moritz; Sauter-Louis, Carola; Seemueller, Andrea; Petzl, Wolfram; Klee, Wolfgang

2014-01-01

Thermograms of the caudal udder surface were taken of five healthy cows before and after inoculation of Escherichia coli into the right hind quarter. Images in clinically normal udder quarters from cows without fever (CN) were compared with those post inoculation when cows had fever (⩾ 39.5°C) and showed elevation of somatic cell counts (⩾ 400,000 cells/mL) in the inoculated quarter (CM). Using graphic software tools, different geometric analysis tools (GATs: polygons, rectangles, lines) were set within the thermographic images. The following descriptive parameters (DPs) were employed: minimum value ('min'), maximum value ('max'), range ('max-min'), and arithmetic mean ('am'). Surface temperatures in group CN were between 34.1°C ('polygons'/'min') and 37.9°C ('polygons'/'max'), and in group CM between 34.5°C ('polygons'/'min') and 40.0°C ('polygons'/'max'). The greatest differences in the temperatures between CN and CM (2.06°C) were found in 'polygons' and 'rectangles' using 'max'. The smallest coefficient of variation in triplicate determinations was found in GAT 'polygons' with DP 'max' (Tmax) (0.15%), and the relationship to the rectal body temperature (Tr) could be described by Tr=5.68+0.874*Tmax. The results show that significant changes can be displayed best using the GAT 'polygons' and the DP 'max'. These methods should be considered for automated monitoring of udder health in dairy cows. Copyright © 2013 Elsevier Ltd. All rights reserved.

Seasonal divergence in the interannual responses of Northern Hemisphere vegetation activity to variations in diurnal climate.

PubMed

Wu, Xiuchen; Liu, Hongyan; Li, Xiaoyan; Liang, Eryuan; Beck, Pieter S A; Huang, Yongmei

2016-01-11

Seasonal asymmetry in the interannual variations in the daytime and nighttime climate in the Northern Hemisphere (NH) is well documented, but its consequences for vegetation activity remain poorly understood. Here, we investigate the interannual responses of vegetation activity to variations of seasonal mean daytime and nighttime climate in NH (>30 °N) during the past decades using remote sensing retrievals, FLUXNET and tree ring data. Despite a generally significant and positive response of vegetation activity to seasonal mean maximum temperature (Tmax) in ~22-25% of the boreal (>50 °N) NH between spring and autumn, spring-summer progressive water limitations appear to decouple vegetation activity from the mean summer Tmax, particularly in climate zones with dry summers. Drought alleviation during autumn results in vegetation recovery from the marked warming-induced drought limitations observed in spring and summer across 24-26% of the temperate NH. Vegetation activity exhibits a pervasively negative correlation with the autumn mean minimum temperature, which is in contrast to the ambiguous patterns observed in spring and summer. Our findings provide new insights into how seasonal asymmetry in the interannual variations in the mean daytime and nighttime climate interacts with water limitations to produce spatiotemporally variable responses of vegetation growth.

Residual stress and damage-induced critical fracture on CO2 laser treated fused silica

NASA Astrophysics Data System (ADS)

Matthews, M. J.; Stolken, J. S.; Vignes, R. M.; Norton, M. A.; Yang, S.; Cooke, J. D.; Guss, G. M.; Adams, J. J.

2009-10-01

Localized damage repair and polishing of silica-based optics using mid- and far-IR CO2 lasers has been shown to be an effective method for increasing optical damage threshold in the UV. However, it is known that CO2 laser heating of silicate surfaces can lead to a level of residual stress capable of causing critical fracture either during or after laser treatment. Sufficient control of the surface temperature as a function of time and position is therefore required to limit this residual stress to an acceptable level to avoid critical fracture. In this work we present the results of 351 nm, 3ns Gaussian damage growth experiments within regions of varying residual stress caused by prior CO2 laser exposures. Thermally stressed regions were non-destructively characterized using polarimetry and confocal Raman microscopy to measure the stress induced birefringence and fictive temperature respectively. For 1~40s square pulse CO2 laser exposures created over 0.5-1.25kW/cm2 with a 1-3mm 1/e2 diameter beam (Tmax~1500-3000K), the critical damage site size leading to fracture increases weakly with peak temperature, but shows a stronger dependence on cooling rate, as predicted by finite element hydrodynamics simulations. Confocal micro-Raman was used to probe structural changes to the glass over different thermal histories and indicated a maximum fictive temperature of 1900K for Tmax>=2000K. The effect of cooling rate on fictive temperature caused by CO2 laser heating are consistent with finite element calculations based on a Tool-Narayanaswamy relaxation model.

Changes of the time-varying percentiles of daily extreme temperature in China

NASA Astrophysics Data System (ADS)

Li, Bin; Chen, Fang; Xu, Feng; Wang, Xinrui

2017-11-01

Identifying the air temperature frequency distributions and evaluating the trends in time-varying percentiles are very important for climate change studies. In order to get a better understanding of the recent temporal and spatial pattern of the temperature changes in China, we have calculated the trends in temporal-varying percentiles of the daily extreme air temperature firstly. Then we divide all the stations to get the spatial patterns for the percentile trends using the average linkage cluster analysis method. To make a comparison, the shifts of trends percentile frequency distribution from 1961-1985 to 1986-2010 are also examined. Important results in three aspects have been achieved: (1) In terms of the trends in temporal-varying percentiles of the daily extreme air temperature, the most intense warming for daily maximum air temperature (Tmax) was detected in the upper percentiles with a significant increasing tendency magnitude (>2.5 °C/50year), and the greatest warming for daily minimum air temperature (Tmin) occurred with very strong trends exceeding 4 °C/50year. (2) The relative coherent spatial patterns for the percentile trends were found, and stations for the whole country had been divided into three clusters. The three primary clusters were distributed regularly to some extent from north to south, indicating the possible large influence of the latitude. (3) The most significant shifts of trends percentile frequency distribution from 1961-1985 to 1986-2010 was found in Tmax. More than half part of the frequency distribution show negative trends less than -0.5 °C/50year in 1961-1985, while showing trends less than 2.5 °C/50year in 1986-2010.

High-resolution projections of 21st century climate over the Athabasca River Basin through an integrated evaluation-classification-downscaling-based climate projection framework

NASA Astrophysics Data System (ADS)

Cheng, Guanhui; Huang, Guohe; Dong, Cong; Zhu, Jinxin; Zhou, Xiong; Yao, Y.

2017-03-01

An evaluation-classification-downscaling-based climate projection (ECDoCP) framework is developed to fill a methodological gap of general circulation models (GCMs)-driven statistical-downscaling-based climate projections. ECDoCP includes four interconnected modules: GCM evaluation, climate classification, statistical downscaling, and climate projection. Monthly averages of daily minimum (Tmin) and maximum (Tmax) temperature and daily cumulative precipitation (Prec) over the Athabasca River Basin (ARB) at a 10 km resolution in the 21st century under four Representative Concentration Pathways (RCPs) are projected through ECDoCP. At the octodecadal scale, temperature and precipitation would increase; after bias correction, temperature would increase with a decreased increment, while precipitation would increase only under RCP 8.5. Interannual variability of climate anomalies would increase from RCPs 4.5, 2.6, 6.0 to 8.5 for temperature and from RCPs 2.6, 4.5, 6.0 to 8.5 for precipitation. Bidecadal averaged climate anomalies would decrease from December-January-February (DJF), March-April-May (MAM), September-October-November (SON) to June-July-August (JJA) for Tmin, from DJF, SON, MAM to JJA for Tmax, and from JJA, MAM, SON to DJF for Prec. Climate projection uncertainties would decrease in May to September for temperature and in November to April for precipitation. Spatial climatic variability would not obviously change with RCPs; climatic anomalies are highly correlated with climate-variable magnitudes. Climate anomalies would decrease from upstream to downstream for temperature, and precipitation would follow an opposite pattern. The north end and the other zones would have colder and warmer days, respectively; precipitation would decrease in the upstream and increase in the remaining region. Climate changes might lead to issues, e.g., accelerated glacier/snow melting, deserving attentions of researchers and the public.

Spatial and seasonal patterns in climate change, temperatures, and precipitation across the United States.

PubMed

Portmann, Robert W; Solomon, Susan; Hegerl, Gabriele C

2009-05-05

Changes in climate during the 20th century differ from region to region across the United States. We provide strong evidence that spatial variations in US temperature trends are linked to the hydrologic cycle, and we also present unique information on the seasonal and latitudinal structure of the linkage. We show that there is a statistically significant inverse relationship between trends in daily temperature and average daily precipitation across regions. This linkage is most pronounced in the southern United States (30-40 degrees N) during the May-June time period and, to a lesser extent, in the northern United States (40-50 degrees N) during the July-August time period. It is strongest in trends in maximum temperatures (T(max)) and 90th percentile exceedance trends (90PET), and less pronounced in the T(max) 10PET and the corresponding T(min) statistics, and it is robust to changes in analysis period. Although previous studies suggest that areas of increased precipitation may have reduced trends in temperature compared with drier regions, a change in sign from positive to negative trends suggests some additional cause. We show that trends in precipitation may account for some, but not likely all, of the cause point to evidence that shows that dynamical patterns (El Niño/Southern Oscillation, North Atlantic Oscillation, etc.) cannot account for the observed effects during May-June. We speculate that changing aerosols, perhaps related to vegetation changes, and increased strength of the aerosol direct and indirect effect may play a role in the observed linkages between these indices of temperature change and the hydrologic cycle.

The effects of tibial intraosseous versus intravenous amiodarone administration in a hypovolemic cardiac arrest procine model.

PubMed

Hampton, Kathryn; Wang, Eric; Argame, Jerome Ivan; Bateman, Tom; Craig, William; Johnson, Don

2016-01-01

This study compared the effects of amiodarone via tibial intraosseous (TIO) and intravenous (IV) routes on return of spontaneous circulation (ROSC), time to ROSC, maximum drug concentration (Cmax), time to maximum concentration (Tmax), and mean concentrations over time in a hypovolemic cardiac arrest model. Prospective, between subjects, randomized experimental design. TriService Research Facility. Yorkshire-cross swine (n = 28). Swine were anesthetized and placed into cardiac arrest. After 2 minutes, cardiopulmonary resuscitation (CPR) was initiated. After an additional 2 minute, 300 mg of amiodarone were administered via the TIO or the IV route. Blood samples were collected over 5 minutes. The plasma concentrations were analyzed using high-performance liquid chromatography tandem mass spectrometry. ROSC, time to ROSC, Cmax, Tmax, and mean concentrations over time. A multivariate analysis of variance indicated that there were no significant differences in the TIO and IV groups in ROSC (p = 0.515), time to ROSC (p = 0.300), Cmax (p = 0.291), or Tmax (p = 0.475). The mean Cmax of the TIO group was 56,292 ± 11,504 ng/mL compared to 74,258 ± 11,504 ng/mL for the IV group. The Tmax for TIO and IV groups were 120 ± 25 and 94 ± 25, respectively. A repeated measures analysis of variance indicated that there were no significant differences between the groups relative to concentrations over time (p > 0.05). The TIO provides rapid and reliable access to administer lifesaving medications during cardiac arrest.

A Comparison of the Regional Circulation in the Feet between Dialysis and Non-Dialysis Patients using Indocyanine Green Angiography.

PubMed

Nishizawa, M; Igari, K; Kudo, T; Toyofuku, T; Inoue, Y; Uetake, H

2017-09-01

Peripheral artery disease in dialysis cases is more prone to critical limb ischemia compared to non-dialysis cases, with a significantly high rate of major amputation of the lower limbs. Lesions are distributed on the more distal side in dialysis critical limb ischemia cases. The aim of this study was to investigate the usefulness of indocyanine green angiography to determine differences in the regional circulation in the foot between dialysis and non-dialysis patients. The subjects included 62 cases, among which 20 were dialysis patients and 42 were non-dialysis patients. We compared the indocyanine green angiography parameters for regions of interest in the dialysis and non-dialysis groups, which included the magnitude of intensity from indocyanine green onset to maximum intensity (Imax), the time from indocyanine green onset to maximum intensity (Tmax), the time elapsed from the fluorescence onset to half the maximum intensity (T1/2), and the time from maximum intensity to declining to 90% of the maximum intensity (Td90%). These indocyanine green angiography parameters were measured at region of interest 1 (the Chopart joint), region of interest 2 (the Lisfranc joint), and region of interest 3 (the distal region of the first metatarsal bone). In the comparison between the dialysis and non-dialysis groups, a significant difference was observed regarding Tmax, T1/2, and Td90%, especially in region of interest 3. In this study, we show that regional tissue perfusion is more deteriorated in dialysis patients compared with non-dialysis patients using indocyanine green angiography. Tmax, T1/2, and Td90% could be useful clinical parameters to compare ischemic severity of the lower limb between dialysis and non-dialysis patients.

Thermal stability and degradation kinetics of kenaf/sol-gel silica hybrid

NASA Astrophysics Data System (ADS)

Yusof, F. A. M.; Hashim, A. S.; Tajudin, Z.

2017-12-01

Thermal stability and degradation kinetics of kenaf/sol-gel silica hybrid materials was investigated by thermogravimetric analysis (TGA). Model-free iso-conversion Flynn-Wall-Ozawa (FWO) and Coats-Redfern-modified (CRm) were chosen to evaluate the activation energy of the kenaf (KF) and kenaf/sol-gel silica (KFS) at heating rates (β) of 10, 20, 30 and 40 °C/min. The results shows that an apparent activation energy was increased for the kenaf/sol-gel silica hybrid (211.59 kJ/mol for FWO and 191.55 kJ/mol for CRm) as compared to kenaf fiber (202.84 kJ/mol for FWO and 186.20 kJ/mol for CRm). Other parameters such as integral procedure decomposition temperature (IPDT), final residual weight (Rf), temperature of maximum degradation rate (Tmax) and residual at maximum temperature (RTmax) were obtained from TGA curves, additionally confirmed the thermal stability of the kenaf/sol-gel silica hybrid. These activation energy values and other findings developed the simplified approach in order to understand the thermal stability and degradation kinetics behavior of kenaf/sol-gel silica hybrid materials.

Crystal growth, structural, low temperature thermoluminescence and mechanical properties of cubic fluoroperovskite single crystal (LiBaF3)

NASA Astrophysics Data System (ADS)

Daniel, D. Joseph; Ramasamy, P.; Ramaseshan, R.; Kim, H. J.; Kim, Sunghwan; Bhagavannarayana, G.; Cheon, Jong-Kyu

2017-10-01

Polycrystalline compounds of LiBaF3 were synthesized using conventional solid state reaction route and the phase purity was confirmed using powder X-ray diffraction technique. Using vertical Bridgman technique single crystal was grown from melt. Rocking curve measurements have been carried out to study the structural perfection of the grown crystal. The single peak of diffraction curve clearly reveals that the grown crystal was free from the structural grain boundaries. The low temperature thermoluminescence of the X-ray irradiated sample has been analyzed and found four distinguishable peaks having maximum temperatures at 18, 115, 133 and 216 K. Activation energy (E) and frequency factor (s) for the individual peaks have been studied using Peak shape method and the computerized curve fitting method combining with the Tmax- TStop procedure. Nanoindentation technique was employed to study the mechanical behaviour of the crystal. The indentation modulus and Vickers hardness of the grown crystal have values of 135.15 GPa and 680.81 respectively, under the maximum indentation load of 10 mN.

Quantifying the effect of Tmax extreme events on local adaptation to climate change of maize crop in Andalusia for the 21st century

NASA Astrophysics Data System (ADS)

Gabaldon, Clara; Lorite, Ignacio J.; Ines Minguez, M.; Lizaso, Jon; Dosio, Alessandro; Sanchez, Enrique; Ruiz-Ramos, Margarita

2015-04-01

Extreme events of Tmax can threaten maize production on Andalusia (Ruiz-Ramos et al., 2011). The objective of this work is to attempt a quantification of the effects of Tmax extreme events on the previously identified (Gabaldón et al., 2013) local adaptation strategies to climate change of irrigated maize crop in Andalusia for the first half of the 21st century. This study is focused on five Andalusia locations. Local adaptation strategies identified consisted on combinations of changes on sowing dates and choice of cultivar (Gabaldón et al., 2013). Modified cultivar features were the duration of phenological phases and the grain filling rate. The phenological and yield simulations with the adaptative changes were obtained from a modelling chain: current simulated climate and future climate scenarios (2013-2050) were taken from a group of regional climate models at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). After bias correcting these data for temperature and precipitation (Dosio and Paruolo, 2011; Dosio et al., 2012) crop simulations were generated by the CERES-maize model (Jones and Kiniry, 1986) under DSSAT platform, previously calibrated and validated. Quantification of the effects of extreme Tmax on maize yield was computed for different phenological stages following Teixeira et al. (2013). A heat stress index was computed; this index assumes that yield-damage intensity due to heat stress increases linearly from 0.0 at a critical temperature to a maximum of 1.0 at a limit temperature. The decrease of crop yield is then computed by a normalized production damage index which combines attainable yield and heat stress index for each location. Selection of the most suitable adaptation strategy will be reviewed and discussed in light of the quantified effect on crop yield of the projected change of Tmax extreme events. This study will contribute to MACSUR knowledge Hub within the Joint Programming Initiative on Agriculture, Food Security and Climate Change (FACCE - JPI) of EU and is financed by MULCLIVAR project (CGL2012-38923-C02-02) and IFAPA project AGR6126 from Junta de Andalucía, Spain. References Dosio A. and Paruolo P., 2011. Bias correction of the ENSEMBLES high-resolution climate change projections for use by impact models: Evaluation on the present climate. Journal of Geophysical Research, VOL. 116, D16106, doi:10.1029/2011JD015934 Dosio A., Paruolo P. and Rojas R., 2012. Bias correction of the ENSEMBLES high resolution climate change projections for use by impact models: Analysis of the climate change signal. Journal of Geophysical Research, Volume 117, D17, doi: 0.1029/2012JD017968 Gabaldón C, Lorite IJ, Mínguez MI, Dosio A, Sánchez-Sánchez E and Ruiz-Ramos M, 2013. Evaluation of local adaptation strategies to climate change of maize crop in Andalusia for the first half of 21st century. Geophysical Research Abstracts. Vol. 15, EGU2013-13625, 2013. EGU General Assembly 2013, April 2013, Vienna, Austria. Jones C.A. and J.R. Kiniry. 1986. CERES-Maize: A simulation model of maize growth and development. Texas A&M Univ. Press, College Station. Ruiz-Ramos M., E. Sanchez, C. Galllardo, and M.I. Minguez. 2011. Impacts of projected maximum temperature extremes for C21 by an ensemble of regional climate models on cereal cropping systems in the Iberian Peninsula. Natural Hazards and Earth System Science 11: 3275-3291. Teixeira EI, Fischer G, van Velthuizen H, Walter C, Ewert F. Global hotspots of heat stress on agricultural crops due to climate change. Agric For Meteorol. 2013;170(15):206-215.

Shrinking windows of opportunity for oak seedling establishment in southern California mountains

USGS Publications Warehouse

Davis, Frank W.; Sweet, Lynn C.; Serra-Diaz, Josep M.; Franklin, Janet; McCullough, Ian M.; Flint, Alan L.; Flint, Lorraine E.; Dingman, John; Regan, Helen M.; Syphard, Alexandra D.; Hannah, Lee; Redmond, Kelly; Moritz, Max A.

2016-01-01

Seedling establishment is a critical step that may ultimately govern tree species’ distribution shifts under environmental change. Annual variation in the location of seed rain and microclimates results in transient “windows of opportunity” for tree seedling establishment across the landscape. These establishment windows vary at fine spatiotemporal scales that are not considered in most assessments of climate change impacts on tree species range dynamics and habitat displacement. We integrate field seedling establishment trials conducted in the southern Sierra Nevada and western Tehachapi Mountains of southern California with spatially downscaled grids of modeled water-year climatic water deficit (CWDwy) and mean August maximum daily temperature (Tmax) to map historical and projected future microclimates suitable for establishment windows of opportunity for Quercus douglasii, a dominant tree species of warm, dry foothill woodlands, and Q. kelloggii, a dominant of cooler, more mesic montane woodlands and forests. Based on quasi-binomial regression models, Q. douglasii seedling establishment is significantly associated with modeled CWDwy and to a lesser degree with modeled Tmax. Q. kelloggii seedling establishment is most strongly associated with Tmax and best predicted by a two-factor model including CWDwy and Tmax. Establishment niche models are applied to explore recruitment window dynamics in the western Tehachapi Mountains, where these species are currently widespread canopy dominants. Establishment windows are projected to decrease by 50–95%, shrinking locally to higher elevations and north-facing slopes by the end of this century depending on the species and climate scenario. These decreases in establishment windows suggest the potential for longer-term regional population declines of the species. While many additional processes regulate seedling establishment and growth, this study highlights the need to account for topoclimatic controls and interannual climatic variation when assessing how seedling establishment and colonization processes could be affected by climate change.

Variation in absorption and half-life of hydrocortisone influence plasma cortisol concentrations.

PubMed

Hindmarsh, Peter C; Charmandari, Evangelia

2015-04-01

Hydrocortisone therapy should be individualized in congenital adrenal hyperplasia (CAH) patients to avoid over and under replacement. We have assessed how differences in absorption and half-life of cortisol influence glucocorticoid exposure. Forty-eight patients (21 M) aged between 6·1 and 20·3 years with CAH due to CYP21A2 deficiency were studied. Each patient underwent a 24-h plasma cortisol profile with the morning dose used to calculate absorption parameters along with an intravenous (IV) hydrocortisone (15 mg/m(2) body surface area) bolus assessment of half-life. Parameters derived were maximum plasma concentration (Cmax ), time of maximum plasma concentration (tmax ), time to attaining plasma cortisol concentration <100 nmol/l and half-life of cortisol. Mean half-life was 76·5 ± 5·2 (range 40-225·3) min, Cmax 780·7 ± 61·6 nmol/l and tmax 66·7 (range 20-118) min. Time taken to a plasma cortisol concentration less than 100 nmol/l was 289 (range 140-540) min. Those with a fast half-life and slow tmax took longest to reach a plasma cortisol concentration less than 100 nmol/l (380 ± 34·6 min), compared to those with a slow half-life and fast tmax (298 ± 34·8 min) and those with a fast half-life and fast tmax (249·5 ± 14·4 min) (One-way anovaF = 4·52; P = 0·009). Both rate of absorption and half-life of cortisol in the circulation play important roles in determining overall exposure to oral glucocorticoid. Dose regimens need to incorporate estimates of these parameters into determining the optimum dosing schedule for individuals. © 2014 John Wiley & Sons Ltd.

Assessment of Air Temperature Trends in the Source Region of Yellow River and Its Sub-Basins, China

NASA Astrophysics Data System (ADS)

Iqbal, Mudassar; Wen, Jun; Wang, Xin; Lan, Yongchao; Tian, Hui; Anjum, Muhammad Naveed; Adnan, Muhammad

2018-02-01

Changes in climatic variables at the sub-basins scale (having different features of land cover) are crucial for planning, development and designing of water resources infrastructure in the context of climate change. Accordingly, to explore the features of climate changes in sub-basins of the Source Region of Yellow River (SRYR), absolute changes and trends of temperature variables, maximum temperature (Tmax), minimum temperature (Tmin), mean temperature (Tavg) and diurnal temperature range (DTR), were analyzed annually and seasonally by using daily observed air temperature dataset from 1965 to 2014. Results showed that annual Tmax, Tmin and Tavg for the SRYR were experiencing warming trends respectively at the rate of 0.28, 0.36 and 0.31°C (10 yr)-1. In comparison with the 1st period (1965-1989), more absolute changes and trends towards increasing were observed during the 2nd period (1990-2014). Apart from Tangnaihai (a low altitude sub-basin), these increasing trends and changes seemed more significant in other basins with highest magnitude during winter. Among sub-basins the increasing trends were more dominant in Huangheyan compared to other sub-basins. The largest increase magnitude of Tmin, 1.24 and 1.18°C (10 yr)-1, occurred in high altitude sub-basins Jimai and Huangheyan, respectively, while the smallest increase magnitude of 0.23°C (10 yr)-1 occurred in a low altitude sub-basin Tangnaihai. The high elevation difference in Tangnaihai probably was the main reason for the less increase in the magnitude of Tmin. In the last decade, smaller magnitude of trend for all temperature variables signified the signal of cooling in the region. Overall, changes of temperature variables had significant spatial and seasonal variations. It implies that seasonal variations of runoff might be greater or different for each sub-basin.

Historical simulations and climate change projections over India by NCAR CCSM4: CMIP5 vs. NEX-GDDP

NASA Astrophysics Data System (ADS)

Sahany, Sandeep; Mishra, Saroj Kanta; Salunke, Popat

2018-03-01

A new bias-corrected statistically downscaled product, namely, the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP), has recently been developed by NASA to help the scientific community in climate change impact studies at local to regional scale. In this work, the product is validated over India and its added value as compared to its CMIP5 counterpart for the NCAR CCSM4 model is analyzed, followed by climate change projections under the RCP8.5 global warming scenario using the two datasets for the variables daily maximum 2-m air temperature (Tmax), daily minimum 2-m air temperature (Tmin), and rainfall. It is found that, overall, the CCSM4-NEX-GDDP significantly reduces many of the biases in CCSM4-CMIP5 for the historical simulations; however, some biases such as the significant overestimation in the frequency of occurrence in the lower tail of the Tmax and Tmin still remain. In regard to rainfall, an important value addition in CCSM4-NEX-GDDP is the alleviation of the significant underestimation of rainfall extremes found in CCSM4-CMIP5. The projected Tmax from CCSM4-NEX-GDDP are in general higher than that projected by CCSM4-CMIP5, suggesting that the risks of heat waves and very hot days could be higher than that projected by the latter. CCSM4-NEX-GDDP projects the frequency of occurrence of the upper extreme values of historical Tmax to increase by a factor of 100 towards the end of century (as opposed to a factor of 10 increase projected by CCSM4-CMIP5). In regard to rainfall, both CCSM4-CMIP5 and CCSM4-NEX-GDDP project an increase in annual rainfall over India under the RCP8.5 global warming scenario progressively from the near term through the far term. However, CCSM4-NEX-GDDP consistently projects a higher magnitude of increase and over a larger area as compared to that projected by CCSM4-CMIP5. Projected daily rainfall distributions from CCSM4-CMIP5 and CCSM4-NEX-GDDP suggest the occurrence of events that have no historical precedents. Worth noting is that the extreme daily rainfall values projected by CCSM4-NEX-GDDP are two to three times larger than that projected by CCSM4-CMIP5.

Climate-based statistical regression models for crop yield forecasting of coffee in humid tropical Kerala, India

NASA Astrophysics Data System (ADS)

Jayakumar, M.; Rajavel, M.; Surendran, U.

2016-12-01

A study on the variability of coffee yield of both Coffea arabica and Coffea canephora as influenced by climate parameters (rainfall (RF), maximum temperature (Tmax), minimum temperature (Tmin), and mean relative humidity (RH)) was undertaken at Regional Coffee Research Station, Chundale, Wayanad, Kerala State, India. The result on the coffee yield data of 30 years (1980 to 2009) revealed that the yield of coffee is fluctuating with the variations in climatic parameters. Among the species, productivity was higher for C. canephora coffee than C. arabica in most of the years. Maximum yield of C. canephora (2040 kg ha-1) was recorded in 2003-2004 and there was declining trend of yield noticed in the recent years. Similarly, the maximum yield of C. arabica (1745 kg ha-1) was recorded in 1988-1989 and decreased yield was noticed in the subsequent years till 1997-1998 due to year to year variability in climate. The highest correlation coefficient was found between the yield of C. arabica coffee and maximum temperature during January (0.7) and between C. arabica coffee yield and RH during July (0.4). Yield of C. canephora coffee had highest correlation with maximum temperature, RH and rainfall during February. Statistical regression model between selected climatic parameters and yield of C. arabica and C. canephora coffee was developed to forecast the yield of coffee in Wayanad district in Kerala. The model was validated for years 2010, 2011, and 2012 with the coffee yield data obtained during the years and the prediction was found to be good.

Heat waves over Central Europe in regional climate model simulations

NASA Astrophysics Data System (ADS)

Lhotka, Ondřej; Kyselý, Jan

2014-05-01

Regional climate models (RCMs) have become a powerful tool for exploring impacts of global climate change on a regional scale. The aim of the study is to evaluate the capability of RCMs to reproduce characteristics of major heat waves over Central Europe in their simulations of the recent climate (1961-2000), with a focus on the most severe and longest Central European heat wave that occurred in 1994. We analyzed 7 RCM simulations with a high resolution (0.22°) from the ENSEMBLES project, driven by the ERA-40 reanalysis. In observed data (the E-OBS 9.0 dataset), heat waves were defined on the basis of deviations of daily maximum temperature (Tmax) from the 95% quantile of summer Tmax distribution in grid points over Central Europe. The same methodology was applied in the RCM simulations; we used corresponding 95% quantiles (calculated for each RCM and grid point) in order to remove the bias of modelled Tmax. While climatological characteristics of heat waves are reproduced reasonably well in the RCM ensemble, we found major deficiencies in simulating heat waves in individual years. For example, METNOHIRHAM simulated very severe heat waves in 1996, when no heat wave was observed. Focusing on the major 1994 heat wave, considerable differences in simulated temperature patterns were found among the RCMs. The differences in the temperature patterns were clearly linked to the simulated amount of precipitation during this event. The 1994 heat wave was almost absent in all RCMs that did not capture the observed precipitation deficit, while it was by far most pronounced in KNMI-RACMO that simulated virtually no precipitation over Central Europe during the 15-day period of the heat wave. By contrast to precipitation, values of evaporative fraction in the RCMs were not linked to severity of the simulated 1994 heat wave. This suggests a possible major contribution of other factors such as cloud cover and associated downward shortwave radiation. Therefore, a more detailed analysis of individual components of the energy budget over Central Europe during and before the 1994 heat wave was performed.

Intranasal Pharmacokinetics of Morphine ARER, a Novel Abuse-Deterrent Formulation: Results from a Randomized, Double-Blind, Four-Way Crossover Study in Nondependent, Opioid-Experienced Subjects

PubMed Central

Pantaleon, Carmela; Iverson, Matthew; Smith, Michael D.; Kinzler, Eric R.; Aigner, Stefan

2018-01-01

Objective To investigate the pharmacokinetics (PK) of Morphine ARER, an extended-release (ER), abuse-deterrent formulation of morphine sulfate after oral and intranasal administration. Methods This randomized, double-blind, double-dummy, placebo-controlled, four-way crossover study assessed the PK of morphine and its active metabolite, M6G, from crushed intranasal Morphine ARER and intact oral Morphine ARER compared with crushed intranasal ER morphine following administration to nondependent, recreational opioid users. The correlation between morphine PK and the pharmacodynamic parameter of drug liking, a measure of abuse potential, was also evaluated. Results Mean maximum observed plasma concentration (Cmax) for morphine was lower with crushed intranasal Morphine ARER (26.2 ng/mL) and intact oral Morphine ARER (18.6 ng/mL), compared with crushed intranasal ER morphine (49.5 ng/mL). The time to Cmax (Tmax) was the same for intact oral and crushed intranasal Morphine ARER (1.6 hours) and longer for crushed intranasal morphine ER (1.1 hours). Higher mean maximum morphine Cmax, Tmax, and abuse quotient (Cmax/Tmax) were positively correlated with maximum effect for drug liking (R2 ≥ 0.9795). Conclusion These data suggest that Morphine ARER maintains its ER profile despite physical manipulation and intranasal administration, which may be predictive of a lower intranasal abuse potential compared with ER morphine.

Effect of oscillator strength and intermediate resonance on the performance of resonant phonon-based terahertz quantum cascade lasers

NASA Astrophysics Data System (ADS)

Fathololoumi, S.; Dupont, E.; Wasilewski, Z. R.; Chan, C. W. I.; Razavipour, S. G.; Laframboise, S. R.; Huang, Shengxi; Hu, Q.; Ban, D.; Liu, H. C.

2013-03-01

We experimentally investigated the effect of oscillator strength (radiative transition diagonality) on the performance of resonant phonon-based terahertz quantum cascade lasers that have been optimized using a simplified density matrix formalism. Our results show that the maximum lasing temperature (Tmax) is roughly independent of laser transition diagonality within the lasing frequency range of the devices under test (3.2-3.7 THz) when cavity loss is kept low. Furthermore, the threshold current can be lowered by employing more diagonal transition designs, which can effectively suppress parasitic leakage caused by intermediate resonance between the injection and the downstream extraction levels. Nevertheless, the current carrying capacity through the designed lasing channel in more diagonal designs may sacrifice even more, leading to electrical instability and, potentially, complete inhibition of the device's lasing operation. We propose a hypothesis based on electric-field domain formation and competition/switching of different current-carrying channels to explain observed electrical instability in devices with lower oscillator strengths. The study indicates that not only should designers maximize Tmax during device optimization but also they should always consider the risk of electrical instability in device operation.

Interplay of antiferromagnetism and Kondo effect in (Ce1-xLax) 8Pd24 Al

NASA Astrophysics Data System (ADS)

Bashir, A. K.; Tchoula Tchokonté, M. B.; Britz, D.; Strydom, A. M.; Kaczorowski, D.

2017-07-01

The interplay of antiferromagnetic (AFM) and Kondo effect in Ce8Pd24 Al with the dilution of Ce with La is investigated by means of electrical and thermal transport and magnetic properties measurements. X - ray diffraction studies confirm a cubic AuCu3 - type crystal structure with space group Pm 3 bar m for all compositions in the alloy series (Ce1-xLax) 8Pd24 Al (0 ≤ x ≤ 1) . Electrical resistivity, ρ (T) results show evolution from coherent Kondo lattice scattering with a well defined Kondo peak at Tmax to incoherent single-ion Kondo scattering with increasing La content x. Magnetoresistivity MR measurements on Ce dilute alloys are negative and analyzed based on the calculations by Schlottmann for the Bethe - ansatz in the framework of the Coqblin - Schrieffer model and yield values of the Kondo temperature TK and the effective moment of the Kondo ion μK. The decrease of Tmax and TK is described by the compressible Kondo lattice model. The thermoelectric power, S(T) measurements are interpreted within the phenomenological resonance model. The Lorentz number, L /L0 increases rapidly on cooling the samples and reaches a maximum value around 6 K. The magnetic susceptibility, χ (T) data at high temperature follow the Curie - Weiss behaviour and yield effective magnetic moments, μeff values across the series close to the value of 2.54 μB expected for the free Ce3+ - ion. The low temperature χ (T) shows an AFM anomaly associated with a Néel temperature TN for alloys in the range 0 ≤ x ≤ 0.2 . No metamagnetic transition was observed from the magnetization results, M (μ0 H) .

Developing a 1 km resolution daily air temperature dataset for urban and surrounding areas in the conterminous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiaoma; Zhou, Yuyu; Asrar, Ghassem R.

High spatiotemporal resolution air temperature (Ta) datasets are increasingly needed for assessing the impact of temperature change on people, ecosystems, and energy system, especially in the urban domains. However, such datasets are not widely available because of the large spatiotemporal heterogeneity of Ta caused by complex biophysical and socioeconomic factors such as built infrastructure and human activities. In this study, we developed a 1-km gridded dataset of daily minimum Ta (Tmin) and maximum Ta (Tmax), and the associated uncertainties, in urban and surrounding areas in the conterminous U.S. for the 2003–2016 period. Daily geographically weighted regression (GWR) models were developedmore » and used to interpolate Ta using 1 km daily land surface temperature and elevation as explanatory variables. The leave-one-out cross-validation approach indicates that our method performs reasonably well, with root mean square errors of 2.1 °C and 1.9 °C, mean absolute errors of 1.5 °C and 1.3 °C, and R 2 of 0.95 and 0.97, for Tmin and Tmax, respectively. The resulting dataset captures reasonably the spatial heterogeneity of Ta in the urban areas, and also captures effectively the urban heat island (UHI) phenomenon that Ta rises with the increase of urban development (i.e., impervious surface area). The new dataset is valuable for studying environmental impacts of urbanization such as UHI and other related effects (e.g., on building energy consumption and human health). The proposed methodology also shows a potential to build a long-term record of Ta worldwide, to fill the data gap that currently exists for studies of urban systems.« less

Long-term patterns of air temperatures, daily temperature range, precipitation, grass-reference evapotranspiration and aridity index in the USA great plains: Part II. Temporal trends

NASA Astrophysics Data System (ADS)

Kukal, M.; Irmak, S.

2016-11-01

Detection of long-term changes in climate variables over large spatial scales is a very important prerequisite to the development of effective mitigation and adaptation measures for the future potential climate change and for developing strategies for future hydrologic balance analyses under changing climate. Moreover, there is a need for effective approaches of providing information about these changes to decision makers, water managers and stakeholders to aid in efficient implementation of the developed strategies. This study involves computation, mapping and analyses of long-term (1968-2013) county-specific trends in annual, growing-season (1st May-30th September) and monthly air temperatures [(maximum (Tmax), minimum (Tmin) and average (Tavg)], daily temperature range (DTR), precipitation, grass reference evapotranspiration (ETo) and aridity index (AI) over the USA Great Plains region using datasets from over 800 weather station sites. Positive trends in annual Tavg, Tmax and Tmin, DTR, precipitation, ETo and AI were observed in 71%, 89%, 85%, 31%, 61%, 38% and 66% of the counties in the region, respectively, whereas these proportions were 48%, 89%, 62%, 20%, 57%, 28%, and 63%, respectively, for the growing-season averages of the same variables. On a regional average basis, the positive trends in growing-season Tavg, Tmax and Tmin, DTR, precipitation, ETo and AI were 0.18 °C decade-1, 0.19 °C decade-1, 0.17 °C decade-1, 0.09 °C decade-1, 1.12 mm yr-1, 0.4 mm yr-1 and 0.02 decade-1, respectively, and the negative trends were 0.21 °C decade-1, 0.06 °C decade-1, 0.09 °C decade-1, 0.22 °C decade-1, 1.16 mm yr-1, 0.76 mm yr-1 and 0.02 decade-1, respectively. The temporal trends were highly variable in space and were appropriately represented using monthly, annual and growing-season maps developed using Geographic Information System (GIS) techniques. The long-term and spatial and temporal information and data for a large region provided in this study can be used to analyze county-level trends in important climatic/hydrologic variables in context of climate change, water resources, agricultural and natural resources response to climate change.

Time required to achieve maximum concentration of amikacin in synovial fluid of the distal interphalangeal joint after intravenous regional limb perfusion in horses.

PubMed

Kilcoyne, Isabelle; Nieto, Jorge E; Knych, Heather K; Dechant, Julie E

2018-03-01

OBJECTIVE To determine the maximum concentration (Cmax) of amikacin and time to Cmax (Tmax) in the distal interphalangeal (DIP) joint in horses after IV regional limb perfusion (IVRLP) by use of the cephalic vein. ANIMALS 9 adult horses. PROCEDURES Horses were sedated and restrained in a standing position and then subjected to IVRLP (2 g of amikacin sulfate diluted to 60 mL with saline [0.9% NaCl] solution) by use of the cephalic vein. A pneumatic tourniquet was placed 10 cm proximal to the accessory carpal bone. Perfusate was instilled with a peristaltic pump over a 3-minute period. Synovial fluid was collected from the DIP joint 5, 10, 15, 20, 25, and 30 minutes after IVRLP; the tourniquet was removed after the 20-minute sample was collected. Blood samples were collected from the jugular vein 5, 10, 15, 19, 21, 25, and 30 minutes after IVRLP. Amikacin was quantified with a fluorescence polarization immunoassay. Median Cmax of amikacin and Tmax in the DIP joint were determined. RESULTS 2 horses were excluded because an insufficient volume of synovial fluid was collected. Median Cmax for the DIP joint was 600 μg/mL (range, 37 to 2,420 μg/mL). Median Tmax for the DIP joint was 15 minutes. CONCLUSIONS AND CLINICAL RELEVANCE Tmax of amikacin was 15 minutes after IVRLP in horses and Cmax did not increase > 15 minutes after IVRLP despite maintenance of the tourniquet. Application of a tourniquet for 15 minutes should be sufficient for completion of IVRLP when attempting to achieve an adequate concentration of amikacin in the synovial fluid of the DIP joint.

Characterizing Air Temperature Changes in the Tarim Basin over 1960–2012

PubMed Central

Peng, Dongmei; Wang, Xiujun; Zhao, Chenyi; Wu, Xingren; Jiang, Fengqing; Chen, Pengxiang

2014-01-01

There has been evidence of warming rate varying largely over space and between seasons. However, little has been done to evaluate the spatial and temporal variability of air temperature in the Tarim Basin, northwest China. In this study, we collected daily air temperature from 19 meteorological stations for the period of 1960–2012, and analyzed annual mean temperature (AMT), the annual minimum (Tmin) and maximum temperature (Tmax), and mean temperatures of all twelve months and four seasons and their anomalies. Trend analyses, standard deviation of the detrended anomaly (SDDA) and correlations were carried out to characterize the spatial and temporal variability of various mean air temperatures. Our data showed that increasing trend was much greater in the Tmin (0.55°C/10a) than in the AMT (0.25°C/10a) and Tmax (0.12°C/10a), and the fluctuation followed the same order. There were large spatial variations in the increasing trends of both AMT (from −0.09 to 0.43 °C/10a) and Tmin (from 0.15 to 1.12°C/10a). Correlation analyses indicated that AMT had a significantly linear relationship with Tmin and the mean temperatures of four seasons. There were also pronounced changes in the monthly air temperature from November to March at decadal time scale. The seasonality (i.e., summer and winter difference) of air temperature was stronger during the period of 1960–1979 than over the recent three decades. Our preliminary analyses indicated that local environmental conditions (such as elevation) might be partly responsible for the spatial variability, and large scale climate phenomena might have influences on the temporal variability of air temperature in the Tarim Basin. In particular, there was a significant correlation between index of El Niño-Southern Oscillation (ENSO) and air temperature of May (P = 0.004), and between the index of Pacific Decadal Oscillation (PDO) and air temperature of July (P = 0.026) over the interannual to decadal time scales. PMID:25375648

Extreme-value statistics of fractional Brownian motion bridges.

PubMed

Delorme, Mathieu; Wiese, Kay Jörg

2016-11-01

Fractional Brownian motion is a self-affine, non-Markovian, and translationally invariant generalization of Brownian motion, depending on the Hurst exponent H. Here we investigate fractional Brownian motion where both the starting and the end point are zero, commonly referred to as bridge processes. Observables are the time t_{+} the process is positive, the maximum m it achieves, and the time t_{max} when this maximum is taken. Using a perturbative expansion around Brownian motion (H=1/2), we give the first-order result for the probability distribution of these three variables and the joint distribution of m and t_{max}. Our analytical results are tested and found to be in excellent agreement, with extensive numerical simulations for both H>1/2 and H<1/2. This precision is achieved by sampling processes with a free end point and then converting each realization to a bridge process, in generalization to what is usually done for Brownian motion.

Evaluation of the CORDEX-Africa multi-RCM hindcast: systematic model errors

NASA Astrophysics Data System (ADS)

Kim, J.; Waliser, Duane E.; Mattmann, Chris A.; Goodale, Cameron E.; Hart, Andrew F.; Zimdars, Paul A.; Crichton, Daniel J.; Jones, Colin; Nikulin, Grigory; Hewitson, Bruce; Jack, Chris; Lennard, Christopher; Favre, Alice

2014-03-01

Monthly-mean precipitation, mean (TAVG), maximum (TMAX) and minimum (TMIN) surface air temperatures, and cloudiness from the CORDEX-Africa regional climate model (RCM) hindcast experiment are evaluated for model skill and systematic biases. All RCMs simulate basic climatological features of these variables reasonably, but systematic biases also occur across these models. All RCMs show higher fidelity in simulating precipitation for the west part of Africa than for the east part, and for the tropics than for northern Sahara. Interannual variation in the wet season rainfall is better simulated for the western Sahel than for the Ethiopian Highlands. RCM skill is higher for TAVG and TMAX than for TMIN, and regionally, for the subtropics than for the tropics. RCM skill in simulating cloudiness is generally lower than for precipitation or temperatures. For all variables, multi-model ensemble (ENS) generally outperforms individual models included in ENS. An overarching conclusion in this study is that some model biases vary systematically for regions, variables, and metrics, posing difficulties in defining a single representative index to measure model fidelity, especially for constructing ENS. This is an important concern in climate change impact assessment studies because most assessment models are run for specific regions/sectors with forcing data derived from model outputs. Thus, model evaluation and ENS construction must be performed separately for regions, variables, and metrics as required by specific analysis and/or assessments. Evaluations using multiple reference datasets reveal that cross-examination, quality control, and uncertainty estimates of reference data are crucial in model evaluations.

Thermal explosion analysis of methyl ethyl ketone peroxide by non-isothermal and isothermal calorimetric applications.

PubMed

Chi, Jen-Hao; Wu, Sheng-Hung; Shu, Chi-Min

2009-11-15

In the past, process incidents attributed to organic peroxides (OPs) that involved near misses, over-pressures, runaway reactions, and thermal explosions occurred because of poor training, human error, incorrect kinetic assumptions, insufficient change management, and inadequate chemical knowledge in the manufacturing process. Calorimetric applications were employed broadly to test organic peroxides on a small-scale because of their thermal hazards, such as exothermic behavior and self-accelerating decomposition in the laboratory. In essence, methyl ethyl ketone peroxide (MEKPO) is highly reactive and exothermically unstable. In recent years, it has undergone many thermal explosions and runaway reaction incidents in the manufacturing process. Differential scanning calorimetry (DSC), vent sizing package 2 (VSP2), and thermal activity monitor (TAM) were employed to analyze thermokinetic parameters and safety index. The intent of the analyses was to facilitate the use of various auto-alarm equipments to detect over-pressure, over-temperature, and hazardous materials leaks for a wide spectrum of operations. Results indicated that MEKPO decomposition is detected at low temperatures (30-40 degrees C), and the rate of decomposition was shown to exponentially increase with temperature and pressure. Determining time to maximum rate (TMR), self-accelerating decomposition temperature (SADT), maximum temperature (T(max)), exothermic onset temperature (T(0)), and heat of decomposition (DeltaH(d)) was essential for identifying early-stage runaway reactions effectively for industries.

Ambient temperature effects on growth of milkfish (Chanos chanos) at aquaculture scale in Blanakan, West Java

NASA Astrophysics Data System (ADS)

A'yun, Q.; Takarina, N. D.

2017-07-01

Growth and survival of fishes can be influenced by temperature [1]. Variation among size like weight and length could be the preference how temperature works on growth of fishes [2]. This could be key factor in determining in production as well as market demand since people like heavy and large fishes. The main purpose of this study was to determine the effects of temperature on the growth of milkfish (Chanos Chanos) on weight and length parameters in fish farms Blanakan. This study conducted to assess the optimal temperature for the growth of fish of different sizes to optimize the culture conditions for raising milkfishes in scale cultivation in Blanakan, West Java. Milkfishes were reared in the aquaculture Blanakan ponds because they can adapt very well. The weight and length of milkfishes were measured together with water temperature. The results showed the temperature min (tmin) and max (tmax) were ranged from 29-35 °C. Based on the result, there were significant differences in mean weight (p = 0.00) between temperature with the fish reared in tmax group having the lowest mean weight (99.87±11.51 g) and fish reared in tmin group having the highest mean weight (277.17±33.76 g). Likewise, the significant differences were also observed in mean length (p = 0.00) between temperature with the fish reared in tmax group having the lowest mean length (176.50±12.50 mm) and fish reared in tmin group having the highest mean length (183.60±23.86 mm). Therefore, this paper confirmed the significant effects of temperature on the fish growth reared in aquaculture ponds. More, maintaining aquaculture to lower temperature can be considered as way to keep growth of milkfish well.

Global Warming and Geographically Scalar Climatic Objects Exist: An Ontologically Realist and Object-Oriented Analysis of the Daymet TMAX Climate Summaries for North America

NASA Astrophysics Data System (ADS)

Jackson, C. P.

2017-12-01

The scientific materialist worldview, what Peter Unger refers to as the Scientiphical worldview, or Scientiphicalism, has been utterly catastrophic for mesoscale objects in general, but, with its closely associated twentieth-century formal logic, this has been especially true for notoriously vague things like climate change, coastlines, mountains and dust storms. That is, any so-called representations or references ultimately suffer the same ontological demise as their referents, no matter how well-defined their boundaries may in fact be. Against this reductionist metaphysics, climatic objects are discretized within three separate ontologically realist systems, Graham Harman's object-oriented philosophy, or ontology (OOO), Markus Gabriel's ontology of fields of sense (OFS) and Tristan Garcia's two systems and new order of time, so as to make an ontological case for any geographically scalar object, beginning with pixels, as well as any notoriously vague thing they are said to represent. Four-month overlapping TMAX seasonals were first developed from the Oak Ridge National Laboratory (ORNL) Daymet climate temperature maximum (TMAX) monthly summaries (1980-2016) for North America and segmented within Trimble's eCognition Developer using the simple and widely familiar quadtree algorithm with a scale parameter of four, in this example. The regression coefficient was then calculated for the resulting 37-year climatic objects and an equally simple classification was applied. The same segmentation and classification was applied to the Daymet annual summaries, as well, for comparison. As was expected, the mean warming and cooling trends are lowest for the annual summary TMAX climatic objects. However, the Fall (SOND) season has the largest and smallest areas of warming and cooling, respectively, and the highest mean trend for warming objects. Conversely, Spring (MAMJ) has the largest and smallest areas undergoing cooling and warming, respectively. Finally, Summer (JJAS) has the highest mean trend for cooling objects. Not only do these highly heterogeneous and variable patterns become readily apparent with each set of objects, but so do any possible anomalies that might warrant further investigation.

Analyzing the future climate change of Upper Blue Nile River basin using statistical downscaling techniques

NASA Astrophysics Data System (ADS)

Fenta Mekonnen, Dagnenet; Disse, Markus

2018-04-01

Climate change is becoming one of the most threatening issues for the world today in terms of its global context and its response to environmental and socioeconomic drivers. However, large uncertainties between different general circulation models (GCMs) and coarse spatial resolutions make it difficult to use the outputs of GCMs directly, especially for sustainable water management at regional scale, which introduces the need for downscaling techniques using a multimodel approach. This study aims (i) to evaluate the comparative performance of two widely used statistical downscaling techniques, namely the Long Ashton Research Station Weather Generator (LARS-WG) and the Statistical Downscaling Model (SDSM), and (ii) to downscale future climate scenarios of precipitation, maximum temperature (Tmax) and minimum temperature (Tmin) of the Upper Blue Nile River basin at finer spatial and temporal scales to suit further hydrological impact studies. The calibration and validation result illustrates that both downscaling techniques (LARS-WG and SDSM) have shown comparable and good ability to simulate the current local climate variables. Further quantitative and qualitative comparative performance evaluation was done by equally weighted and varying weights of statistical indexes for precipitation only. The evaluation result showed that SDSM using the canESM2 CMIP5 GCM was able to reproduce more accurate long-term mean monthly precipitation but LARS-WG performed best in capturing the extreme events and distribution of daily precipitation in the whole data range. Six selected multimodel CMIP3 GCMs, namely HadCM3, GFDL-CM2.1, ECHAM5-OM, CCSM3, MRI-CGCM2.3.2 and CSIRO-MK3 GCMs, were used for downscaling climate scenarios by the LARS-WG model. The result from the ensemble mean of the six GCM showed an increasing trend for precipitation, Tmax and Tmin. The relative change in precipitation ranged from 1.0 to 14.4 % while the change for mean annual Tmax may increase from 0.4 to 4.3 °C and the change for mean annual Tmin may increase from 0.3 to 4.1 °C. The individual result of the HadCM3 GCM has a good agreement with the ensemble mean result. HadCM3 from CMIP3 using A2a and B2a scenarios and canESM2 from CMIP5 GCMs under RCP2.6, RCP4.5 and RCP8.5 scenarios were downscaled by SDSM. The result from the two GCMs under five different scenarios agrees with the increasing direction of three climate variables (precipitation, Tmax and Tmin). The relative change of the downscaled mean annual precipitation ranges from 2.1 to 43.8 % while the change for mean annual Tmax and Tmin may increase in the range from 0.4 to 2.9 °C and from 0.3 to 1.6 °C respectively.

[SEASONAL VARIATION OF MICROVOLT T-WAVE ALTERNANS IN PATIENTS WITH CARDIOVASCULAR DISEASE AND HEALTHY SUBJECTS].

PubMed

Halabi, Gh; Bulanova, N; Aleksandrova, S; Ivanov, G; Aleksandrova, M

2018-05-01

Objective - to access seasonal variation of microvolt T-wave alternans of ECG dispersion mapping in patients with cardiovascular disease and healthy subjects. ECG data of the three groups of healthy subjects have been compared: inhabitants of Beirut, Lebanon (n=51), inhabitants of Moscow, Russia (n=94) and ECG data of healthy subjects (n=44) from the testing ECG database of the PTB - The National Metrology Institute of Germany as well as a group of patients with cardiovascular disease (n=138), inhabitants of Beirut, Lebanon. Microvolt T-wave alternans of ECG dispersion mapping was evaluated in three points - Tbeginning, Tmaximum, Tend. In healthy subjects, the seasonal variation of ECG dispersion mapping microvolt T-wave alternans was nonexistent. Myocardial lesion is characterized by an increase in Tbeg, Tmax, Tend in relation to the healthy individuals. Tbeg values are minimal in winter and summer and increase in spring and autumn. Tend values were reversed - they were maximal in winter and summer, decreasing in spring-autumn period. Seasonal variation of Tmax - Tbeg, and Tmax -Tend was detected: Tmax - Tbeg increased in the winter-summer period and decreased in spring and autumn, Tmax-Tend - increased in the spring-autumn period in relation to the winter-summer period. In patients with cardiovascular disease, in contrast to the healthy, there is a seasonal variation in microvolt T-wave alternans of ECG dispersion mapping, with the maximum differences in the winter and spring seasons, which should be taken into account when applying the method in clinical practice.

Design of a 1200-V ultra-thin partial SOI LDMOS with n-type buried layer

NASA Astrophysics Data System (ADS)

Qiao, Ming; Wang, Yuru; Li, Yanfei; Zhang, Bo; Li, Zhaoji

2014-11-01

A novel 1200-V ultra-thin partial silicon-on-insulator (PSOI) lateral double-diffusion metal oxide semiconductor (LDMOS) with n-type buried (n-buried) layer (NBL PSOI LDMOS) is proposed in this paper. The new PSOI LDMOS features an n-buried layer underneath the n-type drift (n-drift) region close to the source side, providing a large conduction region for majority carriers and a silicon window to improve self-heating effect (SHE). A combination of uniform and linear variable doping (ULVD) profile is utilized in the n-drift region, which alleviates the inherent tradeoff between specific on-resistance (Ron,sp) and breakdown voltage (BV). With the n-drift region length of 80 μm, the NBL PSOI LDMOS obtains a high BV of 1243 V which is improved by around 105 V in comparison to the conventional SOI LDMOS with linear variable doping (LVD) profile for the n-drift region (LVD SOI LDMOS). Besides, the 1200-V NBL PSOI LDMOS has a lower maximum temperature (Tmax) of 333 K at a power (P) of 1 mW/μm which is reduced by around 61 K. Meanwhile, Ron,sp and Tmax of the NBL PSOI LDMOS are lower than those of the conventional LVD SOI LDMOS for a wide range of BV.

Enhancement of the dark matter abundance before reheating: Applications to gravitino dark matter

NASA Astrophysics Data System (ADS)

Garcia, Marcos A. G.; Mambrini, Yann; Olive, Keith A.; Peloso, Marco

2017-11-01

In the first stages of inflationary reheating, the temperature of the radiation produced by inflaton decays is typically higher than the commonly defined reheating temperature TR H˜(ΓϕMP)1/2 where Γϕ is the inflaton decay rate. We consider the effect of particle production at temperatures at or near the maximum temperature attained during reheating. We show that the impact of this early production on the final particle abundance depends strongly on the temperature dependence of the production cross section. For ⟨σ v ⟩˜Tn/Mn +2, and for n <6 , any particle produced at Tmax is diluted by the later generation of entropy near TR H. This applies to cases such as gravitino production in low scale supersymmetric models (n =0 ) or NETDM models of dark matter (n =2 ). However, for n ≥6 the net abundance of particles produced during reheating is enhanced by over an order of magnitude, dominating over the dilution effect. This applies, for instance to gravitino production in high scale supersymmetry models where n =6 .

Carbon X-ray absorption in the local ISM: fingerprints in X-ray Novae spectra

NASA Astrophysics Data System (ADS)

Gatuzz, Efraín; Ness, J.-U.; Gorczyca, T. W.; Hasoglu, M. F.; Kallman, Timothy R.; García, Javier A.

2018-06-01

We present a study of the C K-edge using high-resolution LETGS Chandra spectra of four novae during their super-soft-source (SSS) phase. We identified absorption lines due to C II Kα, C III Kα and C III Kβ resonances. We used these astronomical observations to perform a benchmarking of the atomic data, which involves wavelength shifts of the resonances and photoionization cross-sections. We used improved atomic data to estimate the C II and C III column densities. The absence of physical shifts for the absorption lines, the consistence of the column densities between multiple observations and the high temperature required for the SSS nova atmosphere modeling support our conclusion about an ISM origin of the respective absorption lines. Assuming a collisional ionization equilibrium plasma the maximum temperature derived from the ratio of C II/C III column densities of the absorbers correspond to Tmax < 3.05 × 104 K.

A hot implantation study on the evolution of defects in He ion implanted MgO(1 0 0)

NASA Astrophysics Data System (ADS)

Fedorov, A. V.; van Huis, M. A.; van Veen, A.

2002-05-01

Ion implantation at elevated temperature, so-called hot implantation, was used to study nucleation and thermal stability of the defects. In this work, MgO(1 0 0) single crystal samples were implanted with 30 keV He ions at various implantation temperatures. The implantation doses ranged from 10 14 to 10 16 cm -2. The implantation introduced defects were subsequently studied by thermal helium desorption spectroscopy (THDS) and Doppler broadening positron beam analysis (PBA). The THDS study provides vital information on the kinetics of He release from the sample. PBA technique, being sensitive to the open volume defects, provides complementary information on cavity evolution. The THD study has shown that in most cases helium release is characterised by the activation energy of Q=4.7±0.5 eV with the maximum release temperature of Tmax=1830 K. By applying first order desorption model the pre-exponent factor is estimated as ν=4.3×10 11 s -1.

The Affinity of D2-Like Dopamine Receptor Antagonists Determines the Time to Maximal Effect on Cocaine Self-Administration

PubMed Central

Tabet, Michael R.; Norman, Mantana K.; Fey, Brittney K.; Tsibulsky, Vladimir L.; Millard, Ronald W.

2011-01-01

Differences in the time to maximal effect (Tmax) of a series of dopamine receptor antagonists on the self-administration of cocaine are not consistent with their lipophilicity (octanol-water partition coefficients at pH 7.4) and expected rapid entry into the brain after intravenous injection. It was hypothesized that the Tmax reflects the time required for maximal occupancy of receptors, which would occur as equilibrium was approached. If so, the Tmax should be related to the affinity for the relevant receptor population. This hypothesis was tested using a series of nine antagonists having a 2500-fold range of Ki or Kd values for D2-like dopamine receptors. Rats self-administered cocaine at regular intervals and then were injected intravenously with a dose of antagonist, and the self-administration of cocaine was continued for 6 to 10 h. The level of cocaine at the time of every self-administration (satiety threshold) was calculated throughout the session. The satiety threshold was stable before the injection of antagonist and then increased approximately 3-fold over the baseline value at doses of antagonists selected to produce this approximately equivalent maximal magnitude of effect (maximum increase in the equiactive cocaine concentration, satiety threshold; Cmax). Despite the similar Cmax, the mean Tmax varied between 5 and 157 min across this series of antagonists. Furthermore, there was a strong and significant correlation between the in vivo Tmax values for each antagonist and the affinity for D2-like dopamine receptors measured in vitro. It is concluded that the cocaine self-administration paradigm offers a reliable and predictive bioassay for measuring the affinity of a competitive antagonist for D2-like dopamine receptors. PMID:21606176

Effects of tibial and humerus intraosseous administration of epinephrine in a cardiac arrest swine model.

PubMed

Beaumont, Ltc Denise; Baragchizadeh, Asal; Johnson, Charles; Johnson, Don

2016-01-01

Compare maximum concentration (Cmax), time to maximum concentration (Tmax), mean serum concentration of epinephrine, return of spontaneous circulation (ROSC), time to ROSC, and odds of survival relative to epinephrine administration by humerus intraosseous (HIO), tibial intraosseous (TIO), and intravenous (IV) routes in a swine cardiac arrest model. Prospective, between subjects, randomized experimental design. TriService Research Facility. Yorkshire-cross swine (n = 28). Swine were anesthetized and placed into cardiac arrest. After 2 minutes, cardiopulmonary resuscitation was initiated. After an additional 2 minutes, a dose of 1 mg of epinephrine was administered by HIO, TIO, or the IV routes. Blood samples were collected over 4 minutes and analyzed by high-performance liquid chromatography tandem mass spectrometry. ROSC, time to ROSC, Cmax, Tmax, mean concentrations over time, and odds ratio. There was no significant difference in rate of the ROSC among the TIO, HIO, and IV groups (p > 0.05). There were significant differences in Cmax: the HIO group was significantly higher than the TIO group (p = 0.007), but no significant difference between the IV and HIO (p = 0.33) or the IV and TIO group (p = 0.060). The Tmax was significantly shorter for both the IV and HIO versus the TIO group (p < 0.05), but no difference between IV and HIO (p = 0.328). The odds of survival were higher in the HIO group compared to all other groups. The TIO and HIO provide rapid and reliable access to administer life-saving medications during cardiac arrest.

A Novel Web Application to Analyze and Visualize Extreme Heat Events

NASA Astrophysics Data System (ADS)

Li, G.; Jones, H.; Trtanj, J.

2016-12-01

Extreme heat is the leading cause of weather-related deaths in the United States annually and is expected to increase with our warming climate. However, most of these deaths are preventable with proper tools and services to inform the public about heat waves. In this project, we have investigated the key indicators of a heat wave, the vulnerable populations, and the data visualization strategies of how those populations most effectively absorb heat wave data. A map-based web app has been created that allows users to search and visualize historical heat waves in the United States incorporating these strategies. This app utilizes daily maximum temperature data from NOAA Global Historical Climatology Network which contains about 2.7 million data points from over 7,000 stations per year. The point data are spatially aggregated into county-level data using county geometry from US Census Bureau and stored in Postgres database with PostGIS spatial capability. GeoServer, a powerful map server, is used to serve the image and data layers (WMS and WFS). The JavaScript-based web-mapping platform Leaflet is used to display the temperature layers. A number of functions have been implemented for the search and display. Users can search for extreme heat events by county or by date. The "by date" option allows a user to select a date and a Tmax threshold which then highlights all of the areas on the map that meet those date and temperature parameters. The "by county" option allows the user to select a county on the map which then retrieves a list of heat wave dates and daily Tmax measurements. This visualization is clean, user-friendly, and novel because while this sort of time, space, and temperature measurements can be found by querying meteorological datasets, there does not exist a tool that neatly packages this information together in an easily accessible and non-technical manner, especially in a time where climate change urges a better understanding of heat waves.

Spatio-temporal Trends of Climate Variability in North Carolina

NASA Astrophysics Data System (ADS)

Sayemuzzaman, Mohammad

Climatic trends in spatial and temporal variability of maximum temperature (Tmax), minimum temperature (Tmin), mean temperature (Tmean) and precipitation were evaluated for 249 ground-based stations in North Carolina for 1950-2009. The Mann-Kendall (MK), the Theil-Sen Approach (TSA) and the Sequential Mann-Kendall (SQMK) tests were applied to quantify the significance of trend, magnitude of trend and the trend shift, respectively. The lag-1 serial correlation and double mass curve techniques were used to address the data independency and homogeneity. The pre-whitening technique was used to eliminate the effect of auto correlation of the data series. The difference between minimum and maximum temperatures, and so the diurnal temperature range (DTR), at some stations was found to be decreasing on both an annual and a seasonal basis, with an overall increasing trend in the mean temperature. For precipitation, a statewide increasing trend in fall (highest in November) and decreasing trend in winter (highest in February) were detected. No pronounced increasing/decreasing trends were detected in annual, spring, and summer precipitation time series. Trend analysis on a spatial scale (for three physiographic regions: mountain, piedmont and coastal) revealed mixed results. Coastal zone exhibited increasing mean temperature (warming) trend as compared to other locations whereas mountain zone showed decreasing trend (cooling). Three main moisture components (precipitation, total cloud cover, and soil moisture) and the two major atmospheric circulation modes (North Atlantic Oscillation and Southern Oscillation) were used for correlative analysis purposes with the temperature (specifically with DTR) and precipitation trends. It appears that the moisture components are associated with DTR more than the circulation modes in North Carolina.

Magnetic field and pressure dependant resistivity behaviour of MnAs

NASA Astrophysics Data System (ADS)

Satya, A. T.; Amaladass, E. P.; Mani, Awadhesh

2018-04-01

The studies on the effect of magnetic field and external pressure on temperature dependant electrical resistivity behaviour of polycrystalline MnAs have been reported. At ambient pressure, ρ(T) shows a first order magnetic transition associated with change in sign of the temperature coefficient of resistivity from positive in the ferromagnetic (FM) phase to negative in the paramagnetic (PM) phase. The magneto resistance is negative and shows a peak at the FM transition temperature (T C ). The first order hysteresis width decreases with increase in magnetic field and the intersection of extrapolated linear variations of T C with field for the cooling and warming cycles enabled determination of the tricritical point. At high pressures, ρ(T) displays non monotonic variation exhibiting a low temperature minimum ({T}\\min L) and a high temperature maximum ({T}\\max H) accompanying broad thermal hysteresis above {T}\\min L. It is surmised that spin disorder scattering is responsible for the resistivity behaviour above {T}\\min L and the essential features of ρ(T) are qualitatively explained using Kasuya theoretical model. Below the {T}\\min L, ρ(T) follows linear logarithmic temperature dependence similar to the effect occurring due to Kondo type of scattering of conduction electrons with localised moments.

Simultaneous measurement of glucose blood–brain transport constants and metabolic rate in rat brain using in-vivo 1H MRS

PubMed Central

Du, Fei; Zhang, Yi; Zhu, Xiao-Hong; Chen, Wei

2012-01-01

Cerebral glucose consumption and glucose transport across the blood–brain barrier are crucial to brain function since glucose is the major energy fuel for supporting intense electrophysiological activity associated with neuronal firing and signaling. Therefore, the development of noninvasive methods to measure the cerebral metabolic rate of glucose (CMRglc) and glucose transport constants (KT: half-saturation constant; Tmax: maximum transport rate) are of importance for understanding glucose transport mechanism and neuroenergetics under various physiological and pathological conditions. In this study, a novel approach able to simultaneously measure CMRglc, KT, and Tmax via monitoring the dynamic glucose concentration changes in the brain tissue using in-vivo 1H magnetic resonance spectroscopy (MRS) and in plasma after a brief glucose infusion was proposed and tested using an animal model. The values of CMRglc, Tmax, and KT were determined to be 0.44±0.17 μmol/g per minute, 1.35±0.47 μmol/g per minute, and 13.4±6.8 mmol/L in the rat brain anesthetized with 2% isoflurane. The Monte-Carlo simulations suggest that the measurements of CMRglc and Tmax are more reliable than that of KT. The overall results indicate that the new approach is robust and reliable for in-vivo measurements of both brain glucose metabolic rate and transport constants, and has potential for human application. PMID:22714049

Simultaneous measurement of glucose blood-brain transport constants and metabolic rate in rat brain using in-vivo 1H MRS.

PubMed

Du, Fei; Zhang, Yi; Zhu, Xiao-Hong; Chen, Wei

2012-09-01

Cerebral glucose consumption and glucose transport across the blood-brain barrier are crucial to brain function since glucose is the major energy fuel for supporting intense electrophysiological activity associated with neuronal firing and signaling. Therefore, the development of noninvasive methods to measure the cerebral metabolic rate of glucose (CMR(glc)) and glucose transport constants (K(T): half-saturation constant; T(max): maximum transport rate) are of importance for understanding glucose transport mechanism and neuroenergetics under various physiological and pathological conditions. In this study, a novel approach able to simultaneously measure CMR(glc), K(T), and T(max) via monitoring the dynamic glucose concentration changes in the brain tissue using in-vivo (1)H magnetic resonance spectroscopy (MRS) and in plasma after a brief glucose infusion was proposed and tested using an animal model. The values of CMR(glc), T(max), and K(T) were determined to be 0.44 ± 0.17 μmol/g per minute, 1.35 ± 0.47 μmol/g per minute, and 13.4 ± 6.8 mmol/L in the rat brain anesthetized with 2% isoflurane. The Monte-Carlo simulations suggest that the measurements of CMR(glc) and T(max) are more reliable than that of K(T). The overall results indicate that the new approach is robust and reliable for in-vivo measurements of both brain glucose metabolic rate and transport constants, and has potential for human application.

Effects of tibial and humerus intraosseous and intravenous vasopressin in porcine cardiac arrest model.

PubMed

Adams, Timothy S; Blouin, Dawn; Johnson, Don

2016-01-01

Compare maximum concentration (Cmax), time to maximum concentration (Tmax), mean serum concentration of vasopressin, return of spontaneous circulation (ROSC), time to ROSC, and odds of survival relative to vasopressin administration by tibial intraosseous (TIO), humerus intraosseous (HIO), and intravenous (IV) routes in a hypovolemic cardiac arrest model. Prospective, between subjects, randomized experimental design. TriService Research Facility. Yorkshire-cross swine (n = 40). Swine were anesthetized, exsanguinated to a Class III hemorrhage, and placed into cardiac arrest. After 2 minutes, cardiopulmonary resuscitation was initiated. After an additional 2 minutes, a dose of 40 units of vasopressin was administered by TIO, HIO, or the IV routes. Blood samples were collected over 4 minutes and analyzed by high-performance liquid chromatography tandem mass spectrometry. ROSC, time to ROSC, Cmax, Tmax, mean concentrations over time, and odds ratio. There was no significant difference in rate of ROSC or time to ROSC between the TIO, HIO, and IV groups (p > 0.05). The Cmax was significantly higher in the IV group compared to the TIO group (p = 0.015), but no significant difference between the TIO versus HIO or HIO versus IV groups (p > 0.05). The Tmax was significantly shorter for the HIO compared to the TIO group (p = 0.034), but no significant differences between the IV group compared to the TIO or HIO groups (p > 0.05). The odds of survival were higher in the HIO group compared to all other groups. The TIO and HIO provide rapid and reliable access to administer life-saving medications during cardiac arrest.

Increasing synchrony of high temperature and low flow in western North American streams: Double trouble for coldwater biota?

Treesearch

Ivan Arismendi; Mohammad Safeeq; Sherri L. Johnson; Jason B Dunham; Roy Haggerty

2013-01-01

Flow and temperature are strongly linked environmental factors driving ecosystem processes in streams. Stream temperature maxima (Tmax_w) and stream flow minima (Qmin) can create periods of stress for aquatic organisms. In mountainous areas, such as western North America, recent shifts toward an earlier spring peak flow and...

Conductive reduced graphene oxide/MnO2 carbonized cotton fabrics with enhanced electro -chemical, -heating, and -mechanical properties

NASA Astrophysics Data System (ADS)

Tian, Mingwei; Du, Minzhi; Qu, Lijun; Zhang, Kun; Li, Hongliang; Zhu, Shifeng; Liu, Dongdong

2016-09-01

Versatile and ductile conductive carbonized cotton fabrics decorated with reduced graphene oxide (rGO)/manganese dioxide (MnO2) are prepared in this paper. In order to endow multifunction to cotton fabric, graphene oxide (GO) is deposited on cotton fibers by simple dip-coating route. MnO2 nanoparticles are assembled on the surface of cotton fabric through in-situ chemical solution deposition. MnO2/GO@cotton fabrics are carbonized to achieve conductive fabric (MnO2/rGO@C). The morphologies and structures of obtained fabrics are characterized by SEM, XRD, ICP and element analysis, and their electro-properties including electro-chemical, electro-heating and electro-mechanical properties are evaluated. The MnO2/rGO@C yields remarkable specific capacitance of 329.4 mA h/g at the current density of 100 mA/g, which is more than 40% higher than that of the control carbonized cotton fabric (231 mA h/g). Regarding electro-heating properties, the temperature of MnO2/rGO@C fabric could be monotonically increased to the steady-state maximum temperatures (ΔTmax) of 36 °C within 5 min under the applied voltage 15 V while the ΔTmax = 17 °C of the control case. In addition, MnO2/rGO@C exhibits repeatable electro-mechanical properties and its normalized resistance (R-R0)/R0 could reach 0.78 at a constant strain (curvature = 0.6 cm-1). The MnO2/rGO@C fabric is versatile, scalable, and adaptable to a wide variety of smart textiles applications.

Snoek Relaxation in Fe-Cr Alloys and Interstitial-Substitutional Interaction

NASA Astrophysics Data System (ADS)

Golovin, I. S.; Blanter, M. S.; Schaller, R.

1997-03-01

The internal friction (IF) spectra of -Fe, Fe-Cr ferritic alloys and Cr have been investigated in a frequency range of 0.01 to 10 Hz. A Snoek-type relaxation was found in all the investigated C doped Fe-Cr alloys, starting from pure Fe and finishing with pure Cr. The temperature location of the Snoek peak (Tmax) in -Fe was found to be 315 K (1 Hz). The activation energy deduced from the T - f shift was 0.81 eV. Tmax in Cr was 433 K with an activation energy of 1.11 eV. The Snoek-type peaks in Fe-Cr alloys are much wider than in pure Fe or pure Cr. The temperature location of the peak versus chromium content curve exhibits a maximum in the vicinity of 35 wt% Cr (Tmax was 573 to 578 K, f 1.2 Hz and the activation energy was about 1.45 eV). It is important that Cr atoms in α-Fe have a more pronounced influence on the temperature location of the peak than Fe atoms have in chromium. A new model based on the atomic interactions is proposed to explain the influence of composition on Snoek peak location. The internal friction has been simulated by a Monte Carlo method, using C-C and C-substitutional atom (s) interaction energies. A model of long-range strain-induced (elastic) interaction supplemented by the chemical interaction in the two nearest coordination shells around an immobile substitutional atom was used for the C-s interaction. The interatomic interaction was supposed to affect IF by changing both the carbon atom arrangement (short-range order) and the energy of C atoms in octahedral interstices, and therefore the activation energy of IF. The peak temperatue calculated coincides well with the experimental ones if the value for the chemical interaction in the first coordination shell (Hchem) for C-Cr in Fe is - 0.15 eV and for C-Fe in Cr +0.15 eV. The difference in the influence of Cr in α-Fe and Fe in Cr is accounted for by a difference in the elastic and chemical interaction both between the carbon atoms and the substitutional atoms. The relaxation process in chromium Fe-based alloys is due to the carbon atom diffusion under stress between octahedral interstices of first and second coordination shells around the Cr atoms, and in Cr-based alloys, between second and third shells around the Fe atoms.

Maximum of a Fractional Brownian Motion: Analytic Results from Perturbation Theory.

PubMed

Delorme, Mathieu; Wiese, Kay Jörg

2015-11-20

Fractional Brownian motion is a non-Markovian Gaussian process X_{t}, indexed by the Hurst exponent H. It generalizes standard Brownian motion (corresponding to H=1/2). We study the probability distribution of the maximum m of the process and the time t_{max} at which the maximum is reached. They are encoded in a path integral, which we evaluate perturbatively around a Brownian, setting H=1/2+ϵ. This allows us to derive analytic results beyond the scaling exponents. Extensive numerical simulations for different values of H test these analytical predictions and show excellent agreement, even for large ϵ.

Abundance Variations and Flows in Plage Regions Observed with CDS/SOHO

NASA Astrophysics Data System (ADS)

Rank, G.; Bagalá, L. G.; Czaykowska, A.; Haerendel, G.

1999-10-01

We present results from CDS/SOHO observations of the spotless active region NOAA-8208, obtained on 28th April 1998 near disk center. MDI images show a bipolar magnetic configuration. The regions of enhanced He I emission correspond to the areas with strong magnetic flux and also with bright plage areas seen in Ca II and H-alpha images. A high correlation is found between intensity maps of the transition region lines He I (logTmax = 4.3), O III (logTmax = 5.0), and O V (logTmax = 5.4). The line-of-sight velocities of He I reveal a strong downflow in the plage areas. Further, the line-of-sight velocities of He I, O III, and O V are well correlated, showing that the downflow pattern exists up to temperatures of about 0.25 MK. At higher temperatures (Mg VIII at logTmax = 5.8) this flow is not detected, suggesting that material streams into the plage region from sideways in the high transition region. Maps of the electron density in the transition region have been constructed from several line ratios yielding densities of about 9.0 cm-3 in the plage regions, about dex 0.5 cm-3 higher compared to the surrounding. To study the spatial variation of the first ionization potential (FIP) effect, the abundance ratio has been mapped for the ion ratio MgVI/NeVI. The ratio is highly variable on spatial scales down to a few arcsec from photospheric values to enhancements of a factor of 10. The strongest FIP enhancements are not correlated with transition region line emission, but are found outside of the plage regions. Some areas of strong FIP enhancement appear stretched and elongated, suggesting that the material is confined in loop-like structures.

Inventory of File nam.t00z.smartpr12.tm00.grib2

Science.gov Websites

Temperature [K] 002 surface DPT 12 hour fcst Dew Point Temperature [K] 003 surface SPFH 12 hour fcst Specific 11 hour fcst Temperature [K] 032 surface TMP 10 hour fcst Temperature [K] 033 surface DPT 11 hour fcst Dew Point Temperature [K] 034 surface DPT 10 hour fcst Dew Point Temperature [K] 035 surface TMAX

Inventory of File nam.t00z.smartak12.tm00.grib2

Science.gov Websites

Temperature [K] 002 surface DPT 12 hour fcst Dew Point Temperature [K] 003 surface SPFH 12 hour fcst Specific 11 hour fcst Temperature [K] 032 surface TMP 10 hour fcst Temperature [K] 033 surface DPT 11 hour fcst Dew Point Temperature [K] 034 surface DPT 10 hour fcst Dew Point Temperature [K] 035 surface TMAX

Inventory of File nam.t00z.smarthi12.tm00.grib2

Science.gov Websites

Temperature [K] 002 surface DPT 12 hour fcst Dew Point Temperature [K] 003 surface SPFH 12 hour fcst Specific 11 hour fcst Temperature [K] 032 surface TMP 10 hour fcst Temperature [K] 033 surface DPT 11 hour fcst Dew Point Temperature [K] 034 surface DPT 10 hour fcst Dew Point Temperature [K] 035 surface TMAX

Inventory of File gfs.t06z.smartguam18.tm00.grib2

Science.gov Websites

Temperature [K] 002 surface DPT 18 hour fcst Dew Point Temperature [K] 003 surface SPFH 18 hour fcst Specific TMP 17 hour fcst Temperature [K] 022 surface TMP 16 hour fcst Temperature [K] 023 surface DPT 17 hour fcst Dew Point Temperature [K] 024 surface DPT 16 hour fcst Dew Point Temperature [K] 025 surface TMAX

Evaluation of different methods to estimate daily reference evapotranspiration in ungauged basins in Southern Brazil

NASA Astrophysics Data System (ADS)

Ribeiro Fontoura, Jessica; Allasia, Daniel; Herbstrith Froemming, Gabriel; Freitas Ferreira, Pedro; Tassi, Rutineia

2016-04-01

Evapotranspiration is a key process of hydrological cycle and a sole term that links land surface water balance and land surface energy balance. Due to the higher information requirements of the Penman-Monteith method and the existing data uncertainty, simplified empirical methods for calculating potential and actual evapotranspiration are widely used in hydrological models. This is especially important in Brazil, where the monitoring of meteorological data is precarious. In this study were compared different methods for estimating evapotranspiration for Rio Grande do Sul, the Southernmost State of Brazil, aiming to suggest alternatives to the recommended method (Penman-Monteith-FAO 56) for estimate daily reference evapotranspiration (ETo) when meteorological data is missing or not available. The input dataset included daily and hourly-observed data from conventional and automatic weather stations respectively maintained by the National Weather Institute of Brazil (INMET) from the period of 1 January 2007 to 31 January 2010. Dataset included maximum temperature (Tmax, °C), minimum temperature (Tmin, °C), mean relative humidity (%), wind speed at 2 m height (u2, m s-1), daily solar radiation (Rs, MJ m- 2) and atmospheric pressure (kPa) that were grouped at daily time-step. Was tested the Food and Agriculture Organization of the United Nations (FAO) Penman-Monteith method (PM) at its full form, against PM assuming missing several variables not normally available in Brazil in order to calculate daily reference ETo. Missing variables were estimated as suggested in FAO56 publication or from climatological means. Furthermore, PM was also compared against the following simplified empirical methods: Hargreaves-Samani, Priestley-Taylor, Mccloud, McGuiness-Bordne, Romanenko, Radiation-Temperature, Tanner-Pelton. The statistical analysis indicates that even if just Tmin and Tmax are available, it is better to use PM estimating missing variables from syntetic data than simplified empirical methods evaluated except for Tanner-Pelton and Priestley-Taylor.

Pharmacokinetic Profile of Oral Cannabis in Humans: Blood and Oral Fluid Disposition and Relation to Pharmacodynamic Outcomes

PubMed Central

Vandrey, Ryan; Herrmann, Evan S.; Mitchell, John M.; Bigelow, George E.; Flegel, Ronald; LoDico, Charles; Cone, Edward J.

2017-01-01

Abstract Most research on cannabis pharmacokinetics has evaluated inhaled cannabis, but oral (“edible”) preparations comprise an increasing segment of the cannabis market. To assess oral cannabis pharmacokinetics and pharmacodynamics, healthy adults (N = 6 per dose) were administered cannabis brownies containing 10, 25 or 50 mg 9-tetrahydrocannabinol (THC). Whole blood and oral fluid specimens were obtained at baseline and then for 9 days post-exposure; 6 days in a residential research setting and 3 days as outpatients. Measures of subjective, cardiovascular and performance effects were obtained at baseline and for 8 h post-ingestion. The mean Cmax for THC in whole blood was 1, 3.5 and 3.3 ng/mL for the 10, 25 and 50 mg THC doses, respectively. The mean maximum concentration (Cmax) and mean time to maximum concentration (Tmax) of 11-OH-THC in whole blood were similar to THC. Cmax blood concentrations of THCCOOH were generally higher than THC and had longer Tmax values. The mean Tmax for THC in oral fluid occurred immediately following oral dose administration, and appear to reflect local topical residue rather than systemic bioavailbility. Mean Cmax oral fluid concentrations of THCCOOH were lower than THC, erratic over time and mean Tmax occurred at longer times than THC. The window of THC detection ranged from 0 to 22 h for whole blood (limit of quantitation (LOQ) = 0.5 ng/mL) and 1.9 to 22 h for oral fluid (LOQ = 1.0 ng/mL). Subjective drug and cognitive performance effects were generally dose dependent, peaked at 1.5–3 h post-administration, and lasted 6–8 h. Whole blood cannabinoid concentrations were significantly correlated with subjective drug effects. Correlations between blood cannabinoids and cognitive performance measures, and between oral fluid and all pharmacodynamic outcomes were either non-significant or not orderly by dose. Quantitative levels of cannabinoids in whole blood and oral fluid were low compared with levels observed following inhalation of cannabis. The route of administration is important for interpretation of cannabinoid toxicology. PMID:28158482

Estimating Finite Rate of Population Increase for Sharks Based on Vital Parameters

PubMed Central

Liu, Kwang-Ming; Chin, Chien-Pang; Chen, Chun-Hui; Chang, Jui-Han

2015-01-01

The vital parameter data for 62 stocks, covering 38 species, collected from the literature, including parameters of age, growth, and reproduction, were log-transformed and analyzed using multivariate analyses. Three groups were identified and empirical equations were developed for each to describe the relationships between the predicted finite rates of population increase (λ’) and the vital parameters, maximum age (Tmax), age at maturity (Tm), annual fecundity (f/Rc)), size at birth (Lb), size at maturity (Lm), and asymptotic length (L∞). Group (1) included species with slow growth rates (0.034 yr-1 < k < 0.103 yr-1) and extended longevity (26 yr < Tmax < 81 yr), e.g., shortfin mako Isurus oxyrinchus, dusky shark Carcharhinus obscurus, etc.; Group (2) included species with fast growth rates (0.103 yr-1 < k < 0.358 yr-1) and short longevity (9 yr < Tmax < 26 yr), e.g., starspotted smoothhound Mustelus manazo, gray smoothhound M. californicus, etc.; Group (3) included late maturing species (Lm/L∞ ≧ 0.75) with moderate longevity (Tmax < 29 yr), e.g., pelagic thresher Alopias pelagicus, sevengill shark Notorynchus cepedianus. The empirical equation for all data pooled was also developed. The λ’ values estimated by these empirical equations showed good agreement with those calculated using conventional demographic analysis. The predictability was further validated by an independent data set of three species. The empirical equations developed in this study not only reduce the uncertainties in estimation but also account for the difference in life history among groups. This method therefore provides an efficient and effective approach to the implementation of precautionary shark management measures. PMID:26576058

Lipophilicity affects the pharmacokinetics and toxicity of local anaesthetic agents administered by caudal block.

PubMed

Nava-Ocampo, Alejandro A; Bello-Ramírez, Angélica M

2004-01-01

1. Drugs administered into the epidural space by caudal block are cleared by means of a process potentially affected by the lipophilic character of the compounds. 2. In the present study, we examined the relationship between the octanol-water partition coefficient (log Poct) and the time to reach the maximum plasma drug concentration (tmax) of lignocaine, bupivacaine and ropivacaine administered by caudal block in paediatric patients. We also examined the relationship between log Poct and the toxicity of these local anaesthetic agents in experimental models. The tmax and toxicity data were obtained from the literature. 3. Ropivacaine, with a log Poct of 2.9, exhibited a tmax of 61.6 min. The tmax of lignocaine, with a log Poct of 2.4, and bupivacaine, with a log Poct of with 3.4, were approximately 50% shorter than ropivacaine. At log Poct of approximately 3.0, the toxicity of these local anaesthetic agents was substantially increased. The relationship between log Poct and the convulsive effect in dogs was similar to the relationship between log Poct and the lethal dose in sheep. 4. With local anaesthetic agents, it appears that the relationship between log Poct and drug transfer from the epidural space to the blood stream is parabolic, being the slowest rate of transference at log Poct 3.0. Toxicity, due to plasma availability of these local anaesthetic agents, seems to be increased at log Poct equal or higher than 3.0 secondary to the highest transfer from plasma into the central nervous system.

Tmax Determined Using a Bayesian Estimation Deconvolution Algorithm Applied to Bolus Tracking Perfusion Imaging: A Digital Phantom Validation Study.

PubMed

Uwano, Ikuko; Sasaki, Makoto; Kudo, Kohsuke; Boutelier, Timothé; Kameda, Hiroyuki; Mori, Futoshi; Yamashita, Fumio

2017-01-10

The Bayesian estimation algorithm improves the precision of bolus tracking perfusion imaging. However, this algorithm cannot directly calculate Tmax, the time scale widely used to identify ischemic penumbra, because Tmax is a non-physiological, artificial index that reflects the tracer arrival delay (TD) and other parameters. We calculated Tmax from the TD and mean transit time (MTT) obtained by the Bayesian algorithm and determined its accuracy in comparison with Tmax obtained by singular value decomposition (SVD) algorithms. The TD and MTT maps were generated by the Bayesian algorithm applied to digital phantoms with time-concentration curves that reflected a range of values for various perfusion metrics using a global arterial input function. Tmax was calculated from the TD and MTT using constants obtained by a linear least-squares fit to Tmax obtained from the two SVD algorithms that showed the best benchmarks in a previous study. Correlations between the Tmax values obtained by the Bayesian and SVD methods were examined. The Bayesian algorithm yielded accurate TD and MTT values relative to the true values of the digital phantom. Tmax calculated from the TD and MTT values with the least-squares fit constants showed excellent correlation (Pearson's correlation coefficient = 0.99) and agreement (intraclass correlation coefficient = 0.99) with Tmax obtained from SVD algorithms. Quantitative analyses of Tmax values calculated from Bayesian-estimation algorithm-derived TD and MTT from a digital phantom correlated and agreed well with Tmax values determined using SVD algorithms.

[Usefulness of contact thermography for the evaluation of chemotherapeutic effectiveness in breast cancer].

PubMed

Kurihara, T; Higashi, Y; Suemasu, K; Kanoh, T; Tabei, T; Inoue, K

1993-05-01

We examined temperature differences between a cancerous breast and its counterpart normal one by contact thermography before and after preoperative chemotherapy, and evaluated the relationship between the changes in the thermograms and response to chemotherapy in six patients with breast cancer. We used the following definitions: 1) delta Tmean: temperature differences between a mean temperature of a cancerous breast and that of the contralateral healthy breast; 2) delta Tmax: temperature differences between a cancer-related hyperthermic area in a breast and the mirror area of contralateral breast; 3) and the thermal patterns in thermogram were estimated by the criteria of Tada et al. In responders the thermograms after chemotherapy indicated an improvement in the hyperthermic vascular pattern (HVP) or hyperthermic area and a decrease of delta Tmean and delta Tmax. In contrast, little or no changes were observed in the thermograms of non-responders. Degrees of changes in thermograms reflected the effectiveness of chemotherapy. Our study showed that chemotherapeutic effectiveness may be better evaluated by combining contact thermography with the present method measuring tumor sizes than by only the present one.

Effects of humerus intraosseous versus intravenous amiodarone administration in a hypovolemic porcine model.

PubMed

Holloway, Cpt Monica M; Jurina, Cpt Shannan L; Orszag, Cpt Joshua D; Bragdon, Lt George R; Green, Lt Rustin D; Garcia-Blanco, Jose C; Benham, Brian E; Adams, Ltc Timothy S; Johnson, Don

2016-01-01

To compare the effects of amiodarone administration by humerus intraosseous (HIO) and intravenous (IV) routes on return of spontaneous circulation (ROSC), time to maximum concentration (Tmax), maximum plasma drug concentration (Cmax), time to ROSC, and mean concentrations over time in a hypovolemic cardiac arrest model. Prospective, between subjects, randomized experimental design. TriService Research Facility. Yorkshire-cross swine (n = 28). Swine were anesthetized and placed into cardiac arrest. After 2 minutes, cardiopulmonary resuscitation was initiated. After an additional 2 minutes, amiodarone 300 mg was administered via the HIO or the IV route. Blood samples were collected over 5 minutes. The samples were analyzed using high-performance liquid chromatography tandem mass spectrometry. ROSC, Tmax, Cmax, time to ROSC, and mean concentrations over time. There was no difference in ROSC between the HIO and IV groups; each had five achieve ROSC and two that did not (p = 1). There was no difference in Tmax (p = 0.501) or in Cmax between HIO and IV groups (p = 0.232). Means ± standard deviations in seconds were 94.3 ± 78.3 compared to 115.7 ± 87.3 in the IV versus HIO groups, respectively. The mean ± standard deviation in nanograms per milliliter for the HIO was 49,041 ± 21,107 and 74,258 ± 33,176 for the IV group. There were no significant differences between the HIO and IV groups relative to time to ROSC (p = 0.220). A repeated analysis of variance indicated that there were no significant differences between the groups relative to concentrations over time (p > 0.05). The humerus intraosseous provides rapid and reliable access to administer life-saving medications during cardiac arrest.

Sternal Route More Effective than Tibial Route for Intraosseous Amiodarone Administration in a Swine Model of Ventricular Fibrillation.

PubMed

Burgert, James M; Martinez, Andre; O'Sullivan, Mara; Blouin, Dawn; Long, Audrey; Johnson, Arthur D

2018-01-01

The pharmacokinetics of IO administered lipid soluble amiodarone during ventricular fibrillation (VF) with ongoing CPR are unknown. This study measured mean plasma concentration over 5 minutes, maximum plasma concentration (Cmax), and time to maximum concentration (Tmax) of amiodarone administered by the sternal IO (SIO), tibial IO (TIO), and IV routes in a swine model of VF with ongoing CPR. Twenty-one Yorkshire-cross swine were randomly assigned to three groups: SIO, TIO, and IV. Ventricular fibrillation was induced under general anesthesia. After 4 minutes in VF, 300 mg amiodarone was administered as indicated by group assignment. Serial blood specimens collected at 30, 60, 90, 120, 150, 180, 240, and 300 seconds were analyzed using high performance liquid chromatography with tandem mass spectrometry. The mean plasma concentration of IV amiodarone over 5 minutes was significantly higher than the TIO group at 60 seconds (P = 0.02) and 90 seconds (P = 0.017) post-injection. No significant differences in Cmax between the groups were found (P <0.05). The Tmax of amiodarone was significantly shorter in the SIO (99 secs) and IV (86 secs) groups compared to the TIO group (215 secs); P = 0.002 and P = 0.002, respectively. The SIO and IV routes of amiodarone administration were comparable. The TIO group took nearly three times longer to reach Tmax than the SIO and IV groups, likely indicating depot of lipid-soluble amiodarone in adipose-rich tibial yellow bone marrow. The SIO route was more effective than the TIO route for amiodarone delivery in a swine model of VF with ongoing CPR. Further investigations are necessary to determine if the kinetic differences found between the SIO and TIO routes in this study affect survival of VF in humans.

Bioavailability of the Yuzpe and levonorgestrel regimens of emergency contraception: vaginal vs. oral administration.

PubMed

Kives, Sari; Hahn, Philip M; White, Emily; Stanczyk, Frank Z; Reid, Robert L

2005-03-01

Separate crossover studies compared the bioavailability of oral vs. vaginal routes of administration for the Yuzpe (n=5) and levonorgestrel regimens (n=4) of emergency contraception. Twice the standard dose of the Yuzpe regimen (200 microg of ethinyl estradiol, 1000 microg of levonorgestrel) or the levonorgestrel regimen (1500 microg of levonorgestrel) was self-administered vaginally. One week later, each subject received orally the standard dose of the assigned medication. Serial blood samples were collected over 24 h and assayed for levonorgestrel and ethinyl estradiol (for the Yuzpe regimen only). Paired t tests were used to compare oral vs. vaginal administration for maximum concentration (Cmax), time to maximum concentration (Tmax) and area under the curve over 24 h (AUC0-24). Relative bioavailability (vaginal/oral) was derived from AUC0-24. Vaginal administration of double the standard dose of the Yuzpe regimen resulted in a lower Cmax (vaginal=5.4 vs. oral=14.6 ng/mL, p=.038) and a later Tmax (5.9 vs. 2.0 h, p=.066) for levonorgestrel, compared to oral administration. Corresponding ethinyl estradiol concentrations were higher (786 vs. 391 pg/mL, p=.039) and peaked later (4.0 vs. 1.9 hr, p=.154) with vaginal administration. Relative bioavailabilities for levonorgestrel and ethinyl estradiol were 58% and 175%, respectively. Similarly, vaginal administration of the levonorgestrel regimen resulted in a lower Cmax (vaginal=5.4 vs. oral=15.2 ng/mL, p=.006) and a later Tmax (7.4 vs. 1.3 h, p=.037) for levonorgestel, compared to oral administration. The relative bioavailability was 62%. Our preliminary data suggest that vaginal administration of these emergency contraception regimens appears to require at least three times the standard oral dose to achieve equivalent systemic levonorgestrel concentrations.

Prediction of climate change in Brunei Darussalam using statistical downscaling model

NASA Astrophysics Data System (ADS)

Hasan, Dk. Siti Nurul Ain binti Pg. Ali; Ratnayake, Uditha; Shams, Shahriar; Nayan, Zuliana Binti Hj; Rahman, Ena Kartina Abdul

2017-06-01

Climate is changing and evidence suggests that the impact of climate change would influence our everyday lives, including agriculture, built environment, energy management, food security and water resources. Brunei Darussalam located within the heart of Borneo will be affected both in terms of precipitation and temperature. Therefore, it is crucial to comprehend and assess how important climate indicators like temperature and precipitation are expected to vary in the future in order to minimise its impact. This study assesses the application of a statistical downscaling model (SDSM) for downscaling General Circulation Model (GCM) results for maximum and minimum temperatures along with precipitation in Brunei Darussalam. It investigates future climate changes based on numerous scenarios using Hadley Centre Coupled Model, version 3 (HadCM3), Canadian Earth System Model (CanESM2) and third-generation Coupled Global Climate Model (CGCM3) outputs. The SDSM outputs were improved with the implementation of bias correction and also using a monthly sub-model instead of an annual sub-model. The outcomes of this assessment show that monthly sub-model performed better than the annual sub-model. This study indicates a satisfactory applicability for generation of maximum temperatures, minimum temperatures and precipitation for future periods of 2017-2046 and 2047-2076. All considered models and the scenarios were consistent in predicting increasing trend of maximum temperature, increasing trend of minimum temperature and decreasing trend of precipitations. Maximum overall trend of Tmax was also observed for CanESM2 with Representative Concentration Pathways (RCP) 8.5 scenario. The increasing trend is 0.014 °C per year. Accordingly, by 2076, the highest prediction of average maximum temperatures is that it will increase by 1.4 °C. The same model predicts an increasing trend of Tmin of 0.004 °C per year, while the highest trend is seen under CGCM3-A2 scenario which is 0.009 °C per year. The highest change predicted for the Tmin is therefore 0.9 °C by 2076. The precipitation showed a maximum trend of decrease of 12.7 mm year. It is also seen in the output using CanESM2 data that precipitation will be more chaotic with some reaching 4800 mm per year and also producing low rainfall about 1800 mm per year. All GCMs considered are consistent in predicting it is very likely that Brunei is expected to experience more warming as well as less frequent precipitation events but with a possibility of intensified and drastically high rainfalls in the future.

Pharmacokinetics of gabapentin in a novel gastric-retentive extended-release formulation: comparison with an immediate-release formulation and effect of dose escalation and food.

PubMed

Chen, Cuiping; Cowles, Verne E; Hou, Eddie

2011-03-01

The objectives of the 3 phase I studies described herein were (1) to compare the pharmacokinetics of gabapentin delivered from a novel gastric-retentive dosage form vs an immediate-release formulation, (2) to assess the dose proportionality of the gastric-retentive extended-release formulation, and (3) to determine the effect of food on the pharmacokinetics of gabapentin delivered from this formulation. The time to reach maximum plasma concentration (t(max)) was extended for gabapentin delivered from the gastric-retentive extended-release formulation compared with the immediate-release formulation. A dose-related increase in both the maximum plasma concentration (C(max)) and the area under the plasma concentration-time curve (AUC) was observed as the gabapentin dose increased from 600 to 2400 mg. Fed status and increased fat content delayed t(max) and enhanced C(max) and AUC in proportion to the fat content. The pharmacokinetics of gabapentin delivered from this extended-release formulation allows a reduced dosing frequency while maintaining bioavailability and possibly diminishing the occurrence of adverse events attributable to a slower increase to the peak concentration compared with the immediate-release dosage form.

Antipyretic Therapy in Critically Ill Patients with Sepsis: An Interaction with Body Temperature

PubMed Central

Zhang, Zhongheng; Chen, Lin; Ni, Hongying

2015-01-01

Background and Objective The effect of antipyretic therapy on mortality in patients with sepsis remains undetermined. The present study aimed to investigate the role of antipyretic therapy in ICU patients with sepsis by using a large clinical database. Methods The multiparameter intelligent monitoring in intensive care II (MIMIC- II) database was employed for the study. Adult patients with sepsis were included for analysis. Antipyretic therapy included antipyretic medication and external cooling. Multivariable model with interaction terms were employed to explore the association of antipyretic therapy and mortality risk. Main Results A total of 15,268 patients fulfilled inclusion criteria and were included in the study. In multivariable model by treating temperature as a continuous variable, there was significant interaction between antipyretic therapy and the maximum temperature (Tmax). While antipyretic therapy had no significant effect on mortality in low temperature quintiles, antipyretic therapy was associated with increased risk of death in the quintile with body temperature >39°C (OR: 1.29, 95% CI: 1.04–1.61). Conclusion Our study shows that there is no beneficial effect on reducing mortality risk with the use of antipyretic therapy in ICU patients with sepsis. External cooling may even be harmful in patients with sepsis. PMID:25822614

Determination of Coefficient of Thermal Expansion (CTE) of 20MPa Mass Concrete Using Granite Aggregate

NASA Astrophysics Data System (ADS)

Chee Siang, GO

2017-07-01

Experimental test was carried out to determine the coefficient of thermal expansion (CTE) value of 20MPa mass concrete using granite aggregate. The CTE value was established using procedure proposed by Kada et al. 2002 in determining the magnitude of early-ages CTE through laboratory test which is a rather accurate way by eliminating any possible superimposed effect of others early-age thermal deformation shrinkages such as autogenous, carbonation, plastic and drying shrinkage. This was done by submitting granite concrete block samples instrumented with ST4 vibrating wire extensometers to thermal shocks. The response of the concrete samples to this shock results in a nearly instantaneous deformation, which are measured by the sensor. These deformations, as well as the temperature signal, are used to calculate the CTE. By repeating heat cycles, the variation in the early-ages of concrete CTE over time was monitored and assessed for a period of upto 7 days. The developed CTE value facilitating the verification and validation of actual maximum permissible critical temperature differential limit (rather than arbitrarily follow published value) of cracking potential. For thick sections, internal restraint is dominant and this is governed by differentials mainly. Of the required physical properties for thermal modelling, CTE is of paramount importance that with given appropriate internal restraint factor the condition of cracking due to internal restraint is governs by equation, ΔTmax= 3.663ɛctu / αc. Thus, it can be appreciated that an increase in CTE will lower the maximum allowable differential for cracking avoidance in mass concrete while an increase of tensile strain capacity will increase the maximum allowable temperature differential.

Activity of Highly Dispersed Co/SBA-15 Catalysts (Low Content) in Carbon Black Oxidation

NASA Astrophysics Data System (ADS)

Hassan, Nissrine El; Casale, Sandra; Aouad, Samer; Hanein, Theodor; Jabbour, Karam; Chidiac, Elvis; Khoury, Bilal el; Zakhem, Henri El; Nakat, Hanna El

Cobalt supported on mesoporous silica SBA-15 (0.75, 1.5 and 3 wt% Co) were used as catalysts for the oxidation of carbon black. Catalysts were characterized by N2 sorption, XRD, TEM and TPR. The catalytic activity in CB oxidation was measured. It has been shown that only small cobalt domains (less than 5 nm) are present on all samples. A homogeneous dispersion was obtained for all catalysts. With increasing cobalt loading, crystalline species start to appear. Using an intermediate contact between the CB and the catalyst, the best activity is that of 0.75Co/SBA-15 catalyst where the oxidation reaches the maximum (Tmax) 68 K before the non-catalyzed reaction. On the same catalyst used in tight contact mode with CB, even if Tmax didn't decrease for more than additional 12 K but the Ti decreases by 38K and thus starts 83 K before.

Improving the spatial accuracy in functional magnetic resonance imaging (fMRI) based on the blood oxygenation level dependent (BOLD) effect: benefits from parallel imaging and a 32-channel head array coil at 1.5 Tesla.

PubMed

Fellner, C; Doenitz, C; Finkenzeller, T; Jung, E M; Rennert, J; Schlaier, J

2009-01-01

Geometric distortions and low spatial resolution are current limitations in functional magnetic resonance imaging (fMRI). The aim of this study was to evaluate if application of parallel imaging or significant reduction of voxel size in combination with a new 32-channel head array coil can reduce those drawbacks at 1.5 T for a simple hand motor task. Therefore, maximum t-values (tmax) in different regions of activation, time-dependent signal-to-noise ratios (SNR(t)) as well as distortions within the precentral gyrus were evaluated. Comparing fMRI with and without parallel imaging in 17 healthy subjects revealed significantly reduced geometric distortions in anterior-posterior direction. Using parallel imaging, tmax only showed a mild reduction (7-11%) although SNR(t) was significantly diminished (25%). In 7 healthy subjects high-resolution (2 x 2 x 2 mm3) fMRI was compared with standard fMRI (3 x 3 x 3 mm3) in a 32-channel coil and with high-resolution fMRI in a 12-channel coil. The new coil yielded a clear improvement for tmax (21-32%) and SNR(t) (51%) in comparison with the 12-channel coil. Geometric distortions were smaller due to the smaller voxel size. Therefore, the reduction in tmax (8-16%) and SNR(t) (52%) in the high-resolution experiment seems to be tolerable with this coil. In conclusion, parallel imaging is an alternative to reduce geometric distortions in fMRI at 1.5 T. Using a 32-channel coil, reduction of the voxel size might be the preferable way to improve spatial accuracy.

Tissue-Negative Transient Ischemic Attack: Is There a Role for Perfusion MRI?

PubMed

Grams, Raymond W; Kidwell, Chelsea S; Doshi, Amish H; Drake, Kendra; Becker, Jennifer; Coull, Bruce M; Nael, Kambiz

2016-07-01

Approximately 60% of patients with a clinical transient ischemic attack (TIA) do not have DWI evidence of cerebral ischemia. The purpose of this study was to assess the added diagnostic value of perfusion MRI in the evaluation of patients with TIA who have normal DWI findings. The inclusion criteria for this retrospective study were clinical presentation of TIA at admission with a discharge diagnosis of TIA confirmed by a stroke neurologist, MRI including both DWI and perfusion-weighted imaging within 48 hours of symptom onset, and no DWI lesion. Cerebral blood flow (CBF) and time to maximum of the residue function (Tmax) maps were evaluated independently by two observers. Multivariate analysis was used to assess perfusion findings; clinical variables; age, blood pressure, clinical symptoms, diabetes (ABCD2) score; duration of TIA; and time between MRI and onset and resolution of symptoms. Fifty-two patients (33 women, 19 men; age range, 20-95 years) met the inclusion criteria. A regional perfusion abnormality was identified on either Tmax or CBF maps of 12 of 52 (23%) patients. Seven (58%) of the patients with perfusion abnormalities had hypoperfused lesions best detected on Tmax maps; the other five had hyperperfusion best detected on CBF maps. In 11 of 12 (92%) patients with abnormal perfusion MRI findings, the regional perfusion deficit correlated with the initial neurologic deficits. Multivariable analysis revealed no significant difference in demographics, ABCD2 scores, or presentation characteristics between patients with and those without perfusion abnormalities. Perfusion MRI that includes Tmax and CBF parametric maps adds diagnostic value by depicting regions with delayed perfusion or postischemic hyperperfusion in approximately one-fourth of TIA patients who have normal DWI findings.

A simple and inexpensive system for controlling body temperature in small animal experiments using MRI and the effect of body temperature on the hepatic kinetics of Gd-EOB-DTPA.

PubMed

Murase, Kenya; Assanai, Purapan; Takata, Hiroshige; Saito, Shigeyoshi; Nishiura, Motoko

2013-12-01

The purpose of this study was to develop a simple and inexpensive system for controlling body temperature in small animal experiments using magnetic resonance imaging (MRI) and to investigate the effect of body temperature on the kinetic behavior of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) in the liver. In our temperature-control system, body temperature was controlled using a feedback-regulated heated or cooled air flow generated by two Futon dryers. The switches of the two Futon dryers were controlled using a digital temperature controller, in which the rectal temperature of a mouse measured by an optical fiber thermometer was used as the input. In experimental studies, male ICR mice aged 8weeks old were used and allocated into 5 groups (39-, 36-, 33-, 30-, and 27-degree groups, n=10), in which the body temperature was maintained at 39 °C, 36 °C, 33 °C, 30 °C, and 27 °C, respectively, using our system. The dynamic contrast-enhanced MRI (DCE-MRI) data were acquired with an MRI system for animal experiments equipped with a 1.5-Tesla permanent magnet, for approximately 43min, after the injection of Gd-EOB-DTPA into the tail vein. After correction of the image shift due to the temperature-dependent drift of the Larmor frequency using the gradient-based image registration method with robust estimation of displacement parameters, the kinetic behavior of Gd-EOB-DTPA was analyzed using an empirical mathematical model. With the use of this approach, the upper limit of the relative enhancement (A), the rates of contrast uptake (α) and washout (β), the parameter related to the slope of early uptake (q), the area under the curve (AUC), the maximum relative enhancement (REmax), the time to REmax (Tmax), and the elimination half-life of the contrast agent (T1/2) were calculated. The body temperature of mice could be controlled well by use of our system. Although there were no significant differences in α, AUC, and q among groups, there were significant differences in A, REmax, β, Tmax, and T1/2, indicating that body temperature significantly affects the kinetic behavior of Gd-EOB-DTPA in the liver. In conclusion, our system will be useful for controlling body temperature in small animal experiments using MRI. Because body temperature significantly affects the kinetic behavior of Gd-EOB-DTPA in the liver, the control of body temperature is essential and should be carefully considered when performing DCE-MRI studies in small animal experiments. © 2013.

Investigation of temperature and its indices under climate change scenarios over different regions of Rajasthan state in India

NASA Astrophysics Data System (ADS)

Sharma, Aditya; Sharma, Devesh; Panda, S. K.; Dubey, Swatantra Kumar; Pradhan, Rajani K.

2018-02-01

The ongoing increases in concentrations of atmospheric greenhouse gas will most likely affect global climate for the rest of this century. Global warming brings a huge provocation to society and human beings. Single extreme events and increased climate variability have a greater impact than long-term changes in the mean of climatic variables. This study analyzed the temperature projections for Rajasthan state, India using data obtain from two General Circulation Models (GFCM21 and HadCM3) for three Intergovernmental Panel on Climate Change (IPCC) Special Range of Emission Scenarios (SRES) A1B, A2, and B1. A 30 years of maximum (Tmax) and minimum (Tmin) temperature for the period 1976-2005 has been obtained from India Meteorological Department (IMD) and by using LARS-WG5 to generate the long-term weather series for three different periods i.e. 2011-2040 (2025s), 2041-2070 (2055s), and 2071-2100 (2085s). Further to determine the changes in extreme temperature events, the data for the baseline period and the future periods was represented by eight extreme temperature indices. Results illustrate that an increase in minimum and the maximum temperature are observed in all the three future periods. The average mean temperature for base period and three future periods over four regions of Rajasthan was observed highest in region 3 which shows an incessantly increased in mean temperature about 2.6 °C i.e. north-east and north-west part of Rajasthan. Two GCMs depicts that the incessant temperatures may be increase in the future and future maximum temperature in all the seasons varies from 2.43 °C to 4.27 °C in the direction from south to north of Rajasthan during 2071-2100. While for minimum temperature, the range of temperature changes varies from 0.23 °C to 1.42 °C from south-east to north-west of Rajasthan during 2011-2040. In the temperature indices, the number of tropical nights (TR20), warmest day (TX90p), warmest night (TN90p) and summer days (SU25) is expected to increase during all three future periods. The maximum changes was found in region 2 (39.4 days) and region 1 (38.8 days) during the 2071-2100 periods, followed by 2041-2070 and 2011-2040. In all the four regions, the annual occurrence of Cold Spells Duration Indicator (CSDI) decreased and Warm Spells Duration Indicator (WSDI) increased for all three future periods.

Derivation of hydrous pyrolysis kinetic parameters from open-system pyrolysis

NASA Astrophysics Data System (ADS)

Tseng, Yu-Hsin; Huang, Wuu-Liang

2010-05-01

Kinetic information is essential to predict the temperature, timing or depth of hydrocarbon generation within a hydrocarbon system. The most common experiments for deriving kinetic parameters are mainly by open-system pyrolysis. However, it has been shown that the conditions of open-system pyrolysis are deviant from nature by its low near-ambient pressure and high temperatures. Also, the extrapolation of heating rates in open-system pyrolysis to geological conditions may be questionable. Recent study of Lewan and Ruble shows hydrous-pyrolysis conditions can simulate the natural conditions better and its applications are supported by two case studies with natural thermal-burial histories. Nevertheless, performing hydrous pyrolysis experiment is really tedious and requires large amount of sample, while open-system pyrolysis is rather convenient and efficient. Therefore, the present study aims at the derivation of convincing distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data. Our results unveil that there is a good correlation between open-system Rock-Eval parameter Tmax and the activation energy (Ea) derived from hydrous pyrolysis. The hydrous pyrolysis single Ea can be predicted from Tmax based on the correlation, while the frequency factor (A0) is estimated based on the linear relationship between single Ea and log A0. Because the Ea distribution is more rational than single Ea, we modify the predicted single hydrous pyrolysis Ea into distributed Ea by shifting the pattern of Ea distribution from open-system pyrolysis until the weight mean Ea distribution equals to the single hydrous pyrolysis Ea. Moreover, it has been shown that the shape of the Ea distribution is very much alike the shape of Tmax curve. Thus, in case of the absence of open-system Ea distribution, we may use the shape of Tmax curve to get the distributed hydrous pyrolysis Ea. The study offers a new approach as a simple method for obtaining distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data, which will allow for better estimating hydrocarbon generation.

Pharmacokinetic Profile of Oral Cannabis in Humans: Blood and Oral Fluid Disposition and Relation to Pharmacodynamic Outcomes.

PubMed

Vandrey, Ryan; Herrmann, Evan S; Mitchell, John M; Bigelow, George E; Flegel, Ronald; LoDico, Charles; Cone, Edward J

2017-03-01

Most research on cannabis pharmacokinetics has evaluated inhaled cannabis, but oral ("edible") preparations comprise an increasing segment of the cannabis market. To assess oral cannabis pharmacokinetics and pharmacodynamics, healthy adults (N = 6 per dose) were administered cannabis brownies containing 10, 25 or 50 mg 9-tetrahydrocannabinol (THC). Whole blood and oral fluid specimens were obtained at baseline and then for 9 days post-exposure; 6 days in a residential research setting and 3 days as outpatients. Measures of subjective, cardiovascular and performance effects were obtained at baseline and for 8 h post-ingestion. The mean Cmax for THC in whole blood was 1, 3.5 and 3.3 ng/mL for the 10, 25 and 50 mg THC doses, respectively. The mean maximum concentration (Cmax) and mean time to maximum concentration (Tmax) of 11-OH-THC in whole blood were similar to THC. Cmax blood concentrations of THCCOOH were generally higher than THC and had longer Tmax values. The mean Tmax for THC in oral fluid occurred immediately following oral dose administration, and appear to reflect local topical residue rather than systemic bioavailbility. Mean Cmax oral fluid concentrations of THCCOOH were lower than THC, erratic over time and mean Tmax occurred at longer times than THC. The window of THC detection ranged from 0 to 22 h for whole blood (limit of quantitation (LOQ) = 0.5 ng/mL) and 1.9 to 22 h for oral fluid (LOQ = 1.0 ng/mL). Subjective drug and cognitive performance effects were generally dose dependent, peaked at 1.5-3 h post-administration, and lasted 6-8 h. Whole blood cannabinoid concentrations were significantly correlated with subjective drug effects. Correlations between blood cannabinoids and cognitive performance measures, and between oral fluid and all pharmacodynamic outcomes were either non-significant or not orderly by dose. Quantitative levels of cannabinoids in whole blood and oral fluid were low compared with levels observed following inhalation of cannabis. The route of administration is important for interpretation of cannabinoid toxicology. Published by Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

[Blood glucose and insulin responses to two hypocaloric enteral formulas in patients with diabetes mellitus type 2].

PubMed

de Luis, D A; Izaola, O; de la Fuente, B; Araújo, K

2013-01-01

The aim of this study is to compare the glycaemic and insulinemic response of type 2 diabetic patients after oral administration of 250 ml of two enteral formulas: a specific formula (Novasource Diabet Smartflex) against a standard isocaloric formula. The design was a cross-over study, with the diabetic patients (n = 15) receiving one of the two formulas in random order. Glycaemia and insulinemia curves were performed at 0, 10, 20, 30,60, 90,120,150 and 180 minutes. The variables studied were the area under the curve (AUC(0)-t), maximum concentration (Cmax), the time to reach maximum concentration (Tmax) and the concentrations of biochemical parameters in each study period. We studied 11 males (73.3%) and 4 females (26.7%), the mean age was 56.9 ± 10.9 years. Patients receiving Novasource Diabet showed a lower mean AUC(0)-t of glucose, mean difference - 4,753.26 mg/min/dl (95% CI: -7,256.7 to -2,249.82), also showed a mean insulinemia significantly lower AUC(0)-t, mean difference: 930.27 uU/min/ml (95% CI -1,696.34 to -164.2). The Cmax showed a significantly lower mean blood glucose levels with the specific formula, mean difference -26.89 mg/dl (95% CI -42.11 to -11.67) and insulin, mean difference: -5.39 uU/ml (95% CI: -10.37 to -1.43). The analysis shows that the mean Tmax of glucose with the specific formula are significantly lower, mean difference -19.82 min (95% CI: -32.11 to -7.33), however there was no difference in Tmax of insulin. Finally the analysis of glucose concentrations in the total study shows that the group with the specific formula has a lower mean glucose 25.77 mg / dl (95% CI 18.29 to 33.25), the same fact was detected with insulinemia 4.39 mU/ml (95% CI: 0.927 to 7.87). Diabetic patients treated diabet Novasource had significantly lower mean AUC0-t, Cmax and Tmax in blood glucose curves, also had lower mean AUC(0)-t and Cmax in insulin curves. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

Physical efficiency of Bengali farmers in response to change in environmental factors.

PubMed

Chandra, A M; Mahanta, S; Sadhu, N

1994-06-01

The present study was conducted on young farmers, selected randomly from a village of West Bengal. Their pre-exercise heart rate (HR), blood pressure (BP), mean arterial pressure (MAP), and other physical parameters were recorded. They were asked to perform standard step test at four different times of a day when environmental factors were recorded. Recorded environmental factors were maximum ambient temperature (Tmax), and minimum ambient temperature (Tmin) for the whole day, ambient temperature (Ta), relative humidity (RH), air velocity (AV), and globe temperature (Tg). The barometric pressure (P) was noted to be constant throughout the experiment. Post-exercise HR and MAP were also recorded. Our observations showed that environmental factors changed as the day progressed from the morning to noon and from noon to night; the physiological parameters of the farmers also changed. HR was lowest in the morning and night but highest in the evening while MAP was highest at midday and gradually returned to the pre-exercise level by the evening. The determined Physical Fitness Index (PFI) of the farmers was noted to be lowest at midday but highest at night. Our studies indicate that environmental factors have a role on the physical efficiency of farmers. Ta, RH and Tg appear to be primarily responsible for the alterations in the physiological functions and PFI.

Downscaling GCM Output with Genetic Programming Model

NASA Astrophysics Data System (ADS)

Shi, X.; Dibike, Y. B.; Coulibaly, P.

2004-05-01

Climate change impact studies on watershed hydrology require reliable data at appropriate spatial and temporal resolution. However, the outputs of the current global climate models (GCMs) cannot be used directly because GCM do not provide hourly or daily precipitation and temperature reliable enough for hydrological modeling. Nevertheless, we can get more reliable data corresponding to future climate scenarios derived from GCM outputs using the so called 'downscaling techniques'. This study applies Genetic Programming (GP) based technique to downscale daily precipitation and temperature values at the Chute-du-Diable basin of the Saguenay watershed in Canada. In applying GP downscaling technique, the objective is to find a relationship between the large-scale predictor variables (NCEP data which provide daily information concerning the observed large-scale state of the atmosphere) and the predictand (meteorological data which describes conditions at the site scale). The selection of the most relevant predictor variables is achieved using the Pearson's coefficient of determination ( R2) (between the large-scale predictor variables and the daily meteorological data). In this case, the period (1961 - 2000) is identified to represent the current climate condition. For the forty years of data, the first 30 years (1961-1990) are considered for calibrating the models while the remaining ten years of data (1991-2000) are used to validate those models. In general, the R2 between the predictor variables and each predictand is very low in case of precipitation compared to that of maximum and minimum temperature. Moreover, the strength of individual predictors varies for every month and for each GP grammar. Therefore, the most appropriate combination of predictors has to be chosen by looking at the output analysis of all the twelve months and the different GP grammars. During the calibration of the GP model for precipitation downscaling, in addition to the mean daily precipitation and daily precipitation variability for each month, monthly average dry and wet-spell lengths are also considered as performance criteria. For the cases of Tmax and Tmin, means and variances of these variables corresponding to each month were considered as performance criteria. The GP downscaling results show satisfactory agreement between the observed daily temperature (Tmax and Tmin) and the simulated temperature. However, the downscaling results for the daily precipitation still require some improvement - suggesting further investigation of other grammars. KEY WORDS: Climate change; GP downscaling; GCM.

Kinetic analysis of superparamagnetic iron oxide nanoparticles in the liver of body-temperature-controlled mice using dynamic susceptibility contrast magnetic resonance imaging and an empirical mathematical model.

PubMed

Murase, Kenya; Assanai, Purapan; Takata, Hiroshige; Matsumoto, Nozomi; Saito, Shigeyoshi; Nishiura, Motoko

2015-06-01

The purpose of this study was to develop a method for analyzing the kinetic behavior of superparamagnetic iron oxide nanoparticles (SPIONs) in the murine liver under control of body temperature using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) and an empirical mathematical model (EMM). First, we investigated the influence of body temperature on the kinetic behavior of SPIONs in the liver by controlling body temperature using our temperature-control system. Second, we investigated the kinetic behavior of SPIONs in the liver when mice were injected with various doses of GdCl3, while keeping the body temperature at 36°C. Finally, we investigated it when mice were injected with various doses of zymosan, while keeping the body temperature at 36°C. We also investigated the effect of these substances on the number of Kupffer cells by immunohistochemical analysis using the specific surface antigen of Kupffer cells (CD68). To quantify the kinetic behavior of SPIONs in the liver, we calculated the upper limit of the relative enhancement (A), the rates of early contrast uptake (α) and washout or late contrast uptake (β), the parameter related to the slope of early uptake (q), the area under the curve (AUC), the maximum change of transverse relaxation rate (ΔR2) (ΔR2(max)), the time to ΔR2(max) (Tmax), and ΔR2 at the last time point (ΔR2(last)) from the time courses of ΔR2 using the EMM. The β and Tmax values significantly decreased and increased, respectively, with decreasing body temperature, suggesting that the phagocytic activity of Kupffer cells is significantly affected by body temperature. The AUC, ΔR2(max), and ΔR2(last) values decreased significantly with increasing dose of GdCl3, which was consistent with the change in the number of CD68-positive cells. They increased with increasing dose of zymosan, which was also consistent with the change in the number of CD68-positive cells. These results suggest that AUC, ΔR2(max), and ΔR2(last) reflect the number of Kupffer cells. In conclusion, we presented a method for analyzing the kinetic behavior of SPIONs in the liver using DSC-MRI and EMM, and investigated the influence of body temperature, GdCl3, and zymosan using body-temperature-controlled mice. The present study suggests that control of body temperature is essential for investigating the kinetic behavior of SPIONs in the liver and that our method will be applicable and useful for quantifying the responses of Kupffer cells to various drugs under control of body temperature. Copyright © 2015 Elsevier Inc. All rights reserved.

Dissociation of end systole from end ejection in patients with long-term mitral regurgitation.

PubMed

Brickner, M E; Starling, M R

1990-04-01

To determine whether left ventricular (LV) end systole and end ejection uncouple in patients with long-term mitral regurgitation, 59 patients (22 control patients with atypical chest pain, 21 patients with aortic regurgitation, and 16 patients with mitral regurgitation) were studied with micromanometer LV catheters and radionuclide angiograms. End systole was defined as the time of occurrence (Tmax) of the maximum time-varying elastance (Emax), and end ejection was defined as the time of occurrence of minimum ventricular volume (minV) and zero systolic flow as approximated by the aortic dicrotic notch (Aodi). The temporal relation between end systole and end ejection in the control patients was Tmax (331 +/- 42 [SD] msec), minV (336 +/- 36 msec), and then, zero systolic flow (355 +/- 23 msec). This temporal relation was maintained in the patients with aortic regurgitation. In contrast, in the patients with mitral regurgitation, the temporal relation was Tmax (266 +/- 49 msec), zero systolic flow (310 +/- 37 msec, p less than 0.01 vs. Tmax), and then, minV (355 +/- 37 msec, p less than 0.001 vs. Tmax and p less than 0.01 vs. Aodi). Additionally, the average Tmax occurred earlier in the patients with mitral regurgitation than in the control patients and patients with aortic regurgitation (p less than 0.01, for both), whereas the average time to minimum ventricular volume was similar in all three patient groups. Moreover, the average time to zero systolic flow also occurred earlier in the patients with mitral regurgitation than in the control patients (p less than 0.01) and patients with aortic regurgitation (p less than 0.05). Because of the dissociation of end systole from minimum ventricular volume in the patients with mitral regurgitation, the end-ejection pressure-volume relations calculated at minimum ventricular volume did not correlate (r = -0.09), whereas those calculated at zero systolic flow did correlate (r = 0.88) with the Emax slope values. We conclude that end ejection, defined as minimum ventricular volume, dissociates from end systole in patients with mitral regurgitation because of the shortened time to LV end systole in association with preservation of the time to LV end ejection due to the low impedance to ejection presented by the left atrium. Therefore, pressure-volume relations calculated at minimum ventricular volume might not be useful for assessing LV chamber performance in some patients with mitral regurgitation.

­Assessing the causes of 20th century wetting in the eastern United States

NASA Astrophysics Data System (ADS)

Bishop, D. A.; Williams, P.; Seager, R.; Fiore, A. M.; Cook, B.; Mankin, J. S.; Singh, D.; Smerdon, J. E.; Rao, M. P.

2017-12-01

During the 20th century, a large area of the eastern United States (US) experienced increases in precipitation and reduced warming, with seasonal cooling of daytime temperatures. These trends are in stark contrast with observed drying and warming globally, particularly with those in the western US. While the reduced temperature trends, termed the eastern US `warming hole,' are well documented and have been linked to reduced insolation from aerosols, evaporative cooling from increased precipitation, and natural climate variability, there is little research evaluating the timing, spatial extent, and physical origins of the historical eastern US precipitation trends. Here we investigate: (1) hydroclimate trends and variability across the continental US for 1895-2016 for all seasons, (2) mechanistic links between wetting and cooling trends in the Southeast US, and (3) dynamical links between wetting trends and large-scale atmospheric circulation changes. Our analyses of hydroclimatic trends indicate strong positive trends in fall precipitation in the Southeast and Northeast US, and positive trends in summer precipitation in the Northeast and Midwest US. The Southeast and Midwest wetting trends are coincident with negative trends in mean daily maximum temperatures (TMax), whereas the Northeast US wetting coincides with warming. Cross-wavelet analysis indicates low-frequency anti-phasing between summer precipitation and TMax, particularly in the Southeast US, but there is little coherence in the fall-season relationship. These results support a positive link between precipitation and evaporative cooling, as this mechanism is expected to be most focused in the boreal summer season. To investigate the shift to wetter conditions in the eastern US, we evaluate moisture transport across multiple reanalysis products, surface observations, and CMIP5 model runs. We find a step-shift toward enhanced southerly flow from the Gulf of Mexico into the Southeast and Midwest US that contributes to the observed wetting in the mid-20th century. Initial results indicate a fall-season westward intensification of the Bermuda High linked with southerly flow over the Southeast US. Further work will be needed to diagnose the dynamical drivers and possible role of anthropogenic forcing.

A Spatio-Temporal Analysis of the Relationship Between Near-Surface Air Temperature and Satellite Land Surface Temperatures Using 17 Years of Data from the ATSR Series

NASA Astrophysics Data System (ADS)

Ghent, D.; Good, E.; Bulgin, C.; Remedios, J. J.

2017-12-01

Surface temperatures (ST) over land have traditionally been measured at weather stations. There are many parts of the globe with very few stations, e.g. across much of Africa, leading to gaps in ST datasets, affecting our understanding of how ST is changing, and the impacts of extreme events. Satellites can provide global ST data but these observations represent how hot the land ST (LST; including the uppermost parts of e.g. trees, buildings) is to touch, whereas stations measure the air temperature just above the surface (T2m). Satellite LST data may only be available in cloud-free conditions and data records are frequently <10-15 years in length. Consequently, satellite LST data have not yet featured widely in climate studies. In this study, the relationship between clear-sky satellite LST and all-sky T2m is characterised in space and time using >17 years of data. The analysis uses a new monthly LST climate data record (CDR) based on the Along-Track Scanning Radiometer (ATSR) series, which has been produced within the European Space Agency GlobTemperature project. The results demonstrate the dependency of the global LST-T2m differences on location, land cover, vegetation and elevation. LSTnight ( 10 pm local solar time) is found to be closely coupled with minimum T2m (Tmin) and the two temperatures generally consistent to within ±5 °C (global median LSTnight- Tmin= 1.8 °C, interquartile range = 3.8 °C). The LSTday ( 10 am local time)-maximum T2m (Tmax) variability is higher because LST is strongly influenced by insolation and surface regime (global median LSTday-Tmax= -0.1 °C, interquartile range = 8.1 °C). Correlations for both temperature pairs are typically >0.9 outside of the tropics. A crucial aspect of this study is a comparison between the monthly global anomaly time series of LST and CRUTEM4 T2m. The time series agree remarkably well, with a correlation of 0.9 and 90% of the CDR anomalies falling within the T2m 95% confidence limits (see figure). This analysis provides independent verification of the 1995-2012 T2m anomaly time series, suggesting that LST can provide a complementary perspective on global ST change. The results presented give justification for increasing use of satellite LST data in climate and weather science, both as an independent variable, and to augment T2m data acquired at weather stations.

High resolution statistical downscaling of the EUROSIP seasonal prediction. Application for southeastern Romania

NASA Astrophysics Data System (ADS)

Busuioc, Aristita; Dumitrescu, Alexandru; Dumitrache, Rodica; Iriza, Amalia

2017-04-01

Seasonal climate forecasts in Europe are currently issued at the European Centre for Medium-Range Weather Forecasts (ECMWF) in the form of multi-model ensemble predictions available within the "EUROSIP" system. Different statistical techniques to calibrate, downscale and combine the EUROSIP direct model output are used to optimize the quality of the final probabilistic forecasts. In this study, a statistical downscaling model (SDM) based on canonical correlation analysis (CCA) is used to downscale the EUROSIP seasonal forecast at a spatial resolution of 1km x 1km over the Movila farm placed in southeastern Romania. This application is achieved in the framework of the H2020 MOSES project (http://www.moses-project.eu). The combination between monthly standardized values of three climate variables (maximum/minimum temperatures-Tmax/Tmin, total precipitation-Prec) is used as predictand while combinations of various large-scale predictors are tested in terms of their availability as outputs in the seasonal EUROSIP probabilistic forecasting (sea level pressure, temperature at 850 hPa and geopotential height at 500 hPa). The predictors are taken from the ECMWF system considering 15 members of the ensemble, for which the hindcasts since 1991 until present are available. The model was calibrated over the period 1991-2014 and predictions for summers 2015 and 2016 were achieved. The calibration was made for the ensemble average as well as for each ensemble member. The model was developed for each lead time: one month anticipation for June, two months anticipation for July and three months anticipation for August. The main conclusions from these preliminary results are: best predictions (in terms of the anomaly sign) for Tmax (July-2 months anticipation, August-3 months anticipation) for both years (2015, 2016); for Tmin - good predictions only for August (3 months anticipation ) for both years; for precipitation, good predictions for July (2 months anticipation) in 2015 and August (3 months anticipation) in 2016; failed prediction for June (1-month anticipation) for all parameters. To see if the results obtained for 2015 and 2016 summers are in agreement with the general ECMWF model performance in forecast of the three predictors used in the CCA SDM calibration, the mean bias and root mean square errors (RMSE) calculated over the entire period in each grid point, for each ensemble member and ensemble average were computed. The obtained results are confirmed, showing highest ECMWF performance in forecasting of the three predictors for 3 months anticipation (August) and lowest performance for one month anticipation (June). The added value of the CCA SDM in forecasting local Tmax/Tmin and total precipitation was compared to the ECMWF performance using nearest grid point method. Comparisons were performed for the 1991-2014 period, taking into account the forecast made in May for July. An important improvement was found for the CCA SDM predictions in terms of the RMSE value (computed against observations) for Tmax/Tmin and less for precipitation. The tests are in progress for the other summer months (June, July).

Nuclear pasta in hot dense matter and its implications for neutrino scattering

NASA Astrophysics Data System (ADS)

Roggero, Alessandro; Margueron, Jérôme; Roberts, Luke F.; Reddy, Sanjay

2018-04-01

The abundance of large clusters of nucleons in neutron-rich matter at subnuclear density is found to be greatly reduced by finite-temperature effects when matter is close to β equilibrium, compared to the case where the electron fraction is fixed at Ye>0.1 , as often considered in the literature. Large nuclei and exotic nonspherical nuclear configurations called pasta, favored in the vicinity of the transition to uniform matter at T =0 , dissolve at a relatively low temperature Tu as protons leak out of nuclei and pasta. For matter at β equilibrium with a negligible neutrino chemical potential we find that Tuβ≃4 ±1 MeV for realistic equations of state. This is lower than the maximum temperature Tmaxβ≃9 ±1 MeV at which nuclei can coexist with a gas of nucleons and can be explained by a change in the nature of the transition to uniform matter called retrograde condensation. An important new finding is that coherent neutrino scattering from nuclei and pasta makes a modest contribution to the opacity under the conditions encountered in supernovas and neutron star mergers. This is because large nuclear clusters dissolve at most relevant temperatures, and at lower temperatures, when clusters are present, Coulomb correlations between them suppress coherent neutrino scattering off individual clusters. Implications for neutrino signals from galactic supernovas are briefly discussed.

Initial Design Study of Existing Flight Control System of RPH and Feasibility Study of Implementing HHC on the SH-60B

DTIC Science & Technology

1990-09-01

35 C. HYDRAULICS ............................................. 39 iv VII. CONCLUSIONS AND RECOMMENDATIONS...requirement can be calculated. The maximum RMS torque required was obtained using the following equation: TMAX = t MAr T ZSm (15) 14 IV. RESULTS A...with the addition to added weight on the pitch arm/link 35 assemblies all related components would have to be strengthened to take the centrifugal loads

Improving medium-range and seasonal hydroclimate forecasts in the southeast USA

NASA Astrophysics Data System (ADS)

Tian, Di

Accurate hydro-climate forecasts are important for decision making by water managers, agricultural producers, and other stake holders. Numerical weather prediction models and general circulation models may have potential for improving hydro-climate forecasts at different scales. In this study, forecast analogs of the Global Forecast System (GFS) and Global Ensemble Forecast System (GEFS) based on different approaches were evaluated for medium-range reference evapotranspiration (ETo), irrigation scheduling, and urban water demand forecasts in the southeast United States; the Climate Forecast System version 2 (CFSv2) and the North American national multi-model ensemble (NMME) were statistically downscaled for seasonal forecasts of ETo, precipitation (P) and 2-m temperature (T2M) at the regional level. The GFS mean temperature (Tmean), relative humidity, and wind speed (Wind) reforecasts combined with the climatology of Reanalysis 2 solar radiation (Rs) produced higher skill than using the direct GFS output only. Constructed analogs showed slightly higher skill than natural analogs for deterministic forecasts. Both irrigation scheduling driven by the GEFS-based ETo forecasts and GEFS-based ETo forecast skill were generally positive up to one week throughout the year. The GEFS improved ETo forecast skill compared to the GFS. The GEFS-based analog forecasts for the input variables of an operational urban water demand model were skillful when applied in the Tampa Bay area. The modified operational models driven by GEFS analog forecasts showed higher forecast skill than the operational model based on persistence. The results for CFSv2 seasonal forecasts showed maximum temperature (Tmax) and Rs had the greatest influence on ETo. The downscaled Tmax showed the highest predictability, followed by Tmean, Tmin, Rs, and Wind. The CFSv2 model could better predict ETo in cold seasons during El Nino Southern Oscillation (ENSO) events only when the forecast initial condition was in ENSO. Downscaled P and T2M forecasts were produced by directly downscaling the NMME P and T2M output or indirectly using the NMME forecasts of Nino3.4 sea surface temperatures to predict local-scale P and T2M. The indirect method generally showed the highest forecast skill which occurs in cold seasons. The bias-corrected NMME ensemble forecast skill did not outperform the best single model.

Late Pleistocene environments of the western Noatak basin, northwestern Alaska

USGS Publications Warehouse

Elias, S.A.; Hamilton, T.D.; Edwards, M.E.; Beget, J.E.; Krumhardt, A.P.; Lavoie, C.

1999-01-01

Glacial Lake Noatak formed repeatedly during middle and late Pleistocene time as expanding glaciers from the DeLong Mountains blocked the Noatak River valley. Downcutting by the Noatak River has exposed thick sediment successions in bluffs up to 86 m high. Two river bluffs, Nk-26 and Nk-29A, contain correlative organic-rich flood-plain deposits that were formed during and after deposition of the Old Crow tephra at about the transition between oxygen isotope stage 6 and oxygen isotope stage 5, at the beginning of the last interglaciation. Both bluffs also contain older interglacial or interstadial flood-plain deposits of uncertain age. Pollen and beetle remains were recovered from the older and younger flood-plain deposits at each bluff. Pollen from the younger flood-plain deposits suggests tundra vegetation with local dominance of sedge. Juniperus abundances were locally high, especially around the time of Old Crow tephra deposition. Mutual climatic range (MCR) estimates from the insect fossil assemblages suggest that mean summer temperatures (Tmax) near the time of Old Crow tephra deposition were about 2 ??C colder than modern; mean winter temperatures were very similar to those of today. A younger sample from the same interglacial deposit yielded a Tmax estimate of 2 ??C warmer than modern, signaling interglacial warming. Pollen from the older interglacial deposit at Nk-29A suggests mesic tundra, with boreal forest more distant than it is today. MCR analysis of a possibly correlative older interglacial deposit at Nk-26 suggests a Tmax about 2 ??C below present.

Vastus lateralis single motor unit EMG at the same absolute torque production at different knee angles.

PubMed

Altenburg, T M; de Haan, A; Verdijk, P W L; van Mechelen, W; de Ruiter, C J

2009-07-01

Single motor unit electromyographic (EMG) activity of the knee extensors was investigated at different knee angles with subjects (n = 10) exerting the same absolute submaximal isometric torque at each angle. Measurements were made over a 20 degrees range around the optimum angle for torque production (AngleTmax) and, where feasible, over a wider range (50 degrees ). Forty-six vastus lateralis (VL) motor units were recorded at 20.7 +/- 17.9 %maximum voluntary contraction (%MVC) together with the rectified surface EMG (rsEMG) of the superficial VL muscle. Due to the lower maximal torque capacity at positions more flexed and extended than AngleTmax, single motor unit recruitment thresholds were expected to decrease and discharge rates were expected to increase at angles above and below AngleTmax. Unexpectedly, the recruitment threshold was higher (P < 0.05) at knee angles 10 degrees more extended (43.7 +/- 22.2 N.m) and not different (P > 0.05) at knee angles 10 degrees more flexed (35.2 +/- 17.9 N.m) compared with recruitment threshold at AngleTmax (41.8 +/- 21.4 N.m). Also, unexpectedly the discharge rates were similar (P > 0.05) at the three angles: 11.6 +/- 2.2, 11.6 +/- 2.1, and 12.3 +/- 2.1 Hz. Similar angle independent discharge rates were also found for 12 units (n = 5; 7.4 +/- 5.4 %MVC) studied over the wider (50 degrees ) range, while recruitment threshold only decreased at more flexed angles. In conclusion, the similar recruitment threshold and discharge behavior of VL motor units during submaximal isometric torque production suggests that net motor unit activation did not change very much along the ascending limb of the knee-angle torque relationship. Several factors such as length-dependent twitch potentiation, which may contribute to this unexpected aspect of motor control, are discussed.

Gastrointestinal temperature trends in football linemen during physical exertion under heat stress.

PubMed

Coris, Eric E; Mehra, Shabnam; Walz, Stephen M; Duncanson, Robert; Jennings, Jason; Nugent, Dylan; Zwygart, Kira; Pescasio, Michele

2009-06-01

Exertional heat stroke is the third leading cause of death in US athletes. Elevations in core temperature in the digestive tract (TGI) have correlated with core temperature and are possible indicators of those at increased risk of heat stroke. The primary objective was to compare a.m. vs. p.m. TGI variation in collegiate football linemen during intense "two-a-day" preseason practice. A secondary objective was to compare longitudinal TGI in offensive and defensive linemen. Cross-sectional observational study. Division I Intercollegiate Athletics Football Program. TGI was monitored during consecutive preseason sessions. TGI, heat illness, weight changes, environmental stress, and subjective symptoms. Mean TGI were 37.8°C and 38.3°C during a.m. and p.m. practices, respectively. The a.m. practices revealed higher TGI gain (1.8°C) compared to p.m. (1.4°C). The p.m. practices had higher maximum TGI than a.m. practices (39.1°C versus 38.8, P=0.0001). Mean time to maximum temperature (Tmax) was 1 hr and 30 min for a.m. and 1 hr and 22 min for p.m. practices. Offensive linemen trended toward higher mean TGI than defensive players (38.0°C vs. 36.7°C, P = 0.069). The rate of rise in TGI was significantly greater in a.m. practices. A decrease in rate of TGI rise was seen from the first to last a.m. practices of the week (P = 0.004). Significant TGI elevations in asymptomatic athletes are common in extreme heat during football practice. Intense a.m. practices in full gear result in higher net temperature gain and rate of temperature gain than p.m. practices. Offensive linemen trended toward higher TGI than defensive linemen. As players acclimatized, a decrease in the rate of TGI increase was appreciable, particularly in a.m. practices. Appreciating cumulative heat stress and variations in heat stress related to scheduling of practice is critical.

The pharmacokinetics of mianserin suppositories for rectal administration in dogs and healthy volunteers: a pilot study.

PubMed

Nawata, Shuichi; Kohyama, Noriko; Uchida, Naoki; Numazawa, Satoshi; Ohbayashi, Masayuki; Kobayashi, Yasuna; Iwata, Masanori; Nakajima, Takanori; Saito, Hiroshi; Izuka, Akira; Yamamoto, Toshinori

2016-01-01

We formulated mianserin suppositories for the treatment of delirium and evaluated their pharmacokinetics by measuring plasma drug concentrations in dogs and healthy human volunteers. Mianserin suppositories were prepared by a melting technique using Tetramide® tablets and Witepsol H-15 as the suppository base. Pharmacokinetics of this 30-mg mianserin preparation were evaluated in three beagle dogs and three healthy adult males, in line with ethics committee approval. Plasma mianserin levels were determined using gas chromatography-mass spectrometry. In dogs, the maximum plasma mianserin concentration (Cmax) was 1.3 ± 0.4 ng/mL, the time to Cmax (tmax) was 5.5 ± 4.3 h, and the area under the plasma concentration-time curve from 0 to 24 h (AUC0-24) was 18.9 ± 1.9 h・ng/mL. In humans, the Cmax was 14.6 ± 6.3 ng/mL, the tmax was 8 h, and the AUC0-24 was 266 ± 103 h・ng/mL. The current study characterized the pharmacokinetics of mianserin suppositories in dogs and humans. As compared to oral administration, the suppositories produced a lower Cmax and a delayed tmax, although AUC0-24 values were comparable. It will be necessary to identify an appropriate dose that produces an adequate plasma mianserin concentration for effective and safe clinical use. UMIN000013853.

Bioavailability of fluoride in drinking water: a human experimental study.

PubMed

Maguire, A; Zohouri, F V; Mathers, J C; Steen, I N; Hindmarch, P N; Moynihan, P J

2005-11-01

It has been suggested that systemic fluoride absorption from drinking water may be influenced by the type of fluoride compound in the water and by water hardness. Using a human double-blind cross-over trial, we conducted this study to measure c(max), T(max), and Area Under the Curve (AUC) for plasma F concentration against time, following the ingestion of naturally fluoridated hard and soft waters, artificially fluoridated hard and soft waters, and a reference water. Mean AUC over 0 to 8 hours was 1330, 1440, 1679, 1566, and 1328 ng F.min.mL(-1) for naturally fluoridated soft, naturally fluoridated hard, artificially fluoridated soft, artificially fluoridated hard, and reference waters, respectively, with no statistically significant differences among waters for AUC, c(max), or T(max). Any differences in fluoride bioavailability between drinking waters in which fluoride is present naturally or added artificially, or the waters are hard or soft, were small compared with large within- and between-subject variations in F absorption. Abbreviations used: F, fluoride; AUC, Area under the Curve for plasma F concentration against time; AUC(0-3), Area under the Curve for plasma F concentration against time for 0 to 3 hours following water ingestion; AUC(0-8), Area under the Curve for plasma F concentration against time for 0 to 8 hours following water ingestion; c(max), maximum plasma F concentration corrected for baseline plasma F and dose (i.e., F concentration of individual waters); T(max), time of c(max).

The 2016 southeastern US drought: an extreme departure from centennial wetting and cooling

NASA Astrophysics Data System (ADS)

Williams, P.; Cook, B. I.; Smerdon, J. E.; Bishop, D. A.; Seager, R.; Mankin, J. S.

2017-12-01

The southeastern United States (SE US) drought in fall 2016 appeared exceptional based on its wildfire and water-supply impacts but the current monitoring framework does not readily facilitate evaluation of moisture-balance anomalies in a centennial context. A new method to extend modeled soil-moisture records back to 1895 is developed using monthly climate data. Since 1895, October-November 2016 soil moisture (0-200 cm) in the SE US was likely the second lowest on record, behind 1954. This severe drought developed rapidly and was brought on by near record-low September-November precipitation and record-high September-November daily maximum temperatures (Tmax). Record Tmax drove record-high atmospheric moisture demand, accounting for 28% of the October-November 2016 soil-moisture anomaly. Drought and heat in fall 2016 contrasted strongly with 20th-century wetting and cooling trends, with few analogs after the mid-1950s. Dynamically, the exceptional drying in fall 2016 was driven by anomalous ridging over the central United States that reduced south-southwesterly moisture transports into the SE US by approximately 75%. These circulation anomalies were promoted by moderate La Niña conditions and warmth in the tropical North Atlantic, but these processes did not account for a majority of the SE US drying in fall 2016 and therefore imply a large role for internal atmospheric variability. The extended analysis back to 1895 indicates that SE US droughts as strong as the 2016 event are more likely than indicated from a shorter 60-year perspective, and continued multi-decadal swings in precipitation may combine with future warming to further enhance the likelihood of such events.

[Biomechanical research of antegrade intramedullary fixation for the metacarpal fractures].

PubMed

Zhang, Li-shan; Pan, Yong-wei; Tian, Guang-lei; Li, Wen-jun; Xia, Shao-hua; Tao, Jian-feng

2010-04-15

To study the biomechanical characteristics of antegrade intramedullary fixation for metacarpal fractures. From March to May 2008, both the 4th and 5th metacarpals from 25 formalin embalmed cadaver hands had three-point bending test after transverse osteotomy followed by randomly fixation with one of the following three methods: plate and screw, antegrade intramedullary K-wire, crossed K-wire. While, both the 2nd and 3rd metacarpals had torsional loading test after the same management as the 4th and 5th metacarpal had undergone. In the three-point bending test, both the maximum bending moment (M(max)) and bending rigidity (EI) of the antegrade intramedullary K-wire were comparable with those of the plate and screw, and were significantly larger than those of the crossed K-wire. In the torsional loading test, the antegrade intramedullary K-wire had a statistically smaller maximum torque (T(max)) than the plate and screw, and had a comparable T(max) with the crossed K-wire; while, the torsional rigidity (GJ) of the intramedullary K-wire was statistically weaker than that of both the plate and screw and the crossed wire. One single antegrade intramedullary K-wire can provide a satisfactory M(max) and EI for metacarpal fixation and shows relatively weak in the torsional loading test. The injured finger should be well protected to avoid torsional deformity in clinical practice.

Perturbative expansion for the maximum of fractional Brownian motion.

PubMed

Delorme, Mathieu; Wiese, Kay Jörg

2016-07-01

Brownian motion is the only random process which is Gaussian, scale invariant, and Markovian. Dropping the Markovian property, i.e., allowing for memory, one obtains a class of processes called fractional Brownian motion, indexed by the Hurst exponent H. For H=1/2, Brownian motion is recovered. We develop a perturbative approach to treat the nonlocality in time in an expansion in ɛ=H-1/2. This allows us to derive analytic results beyond scaling exponents for various observables related to extreme value statistics: the maximum m of the process and the time t_{max} at which this maximum is reached, as well as their joint distribution. We test our analytical predictions with extensive numerical simulations for different values of H. They show excellent agreement, even for H far from 1/2.

Application of infrared thermography for online monitoring of wall temperatures in inductively coupled plasma torches with conventional and low-flow gas consumption

NASA Astrophysics Data System (ADS)

Engelhard, Carsten; Scheffer, Andy; Maue, Thomas; Hieftje, Gary M.; Buscher, Wolfgang

2007-10-01

Inductively coupled plasma (ICP) sources typically used for trace elemental determination and speciation were investigated with infrared (IR) thermography to obtain spatially resolved torch temperature distributions. Infrared thermographic imaging is an excellent tool for the monitoring of temperatures in a fast and non-destructive way. This paper presents the first application of IR thermography to inductively coupled plasma torches and the possibility to investigate temperatures and thermal patterns while the ICP is operating and despite background emission from the plasma itself. A fast and easy method is presented for the determination of temperature distributions and stress features within ICP torches. Two different ICP operating torches were studied: a commercially available Fassel-type ICP unit with 14 L min - 1 total Ar consumption and a SHIP torch with the unusually low Ar flow of 0.6 L min - 1 . Spatially resolved infrared images of both torches were obtained and laterally resolved temperature profiles were extracted. After temperature-resolved calibration of the emissivity (between 0.5 and 0.35 at 873-1323 K) and transmission (20% between 3.75 and 4.02 μm) of the fused quartz used in the torch construction, an image correction was applied. Inhomogeneous temperature distributions with locally defined stress areas in the conventional Fassel-type torch were revealed. As a general trend, it was found that the SHIP torch exhibited higher temperatures ( Tmax = 1580 K) than the conventional torch ( Tmax = 730 K). In the former case, torch sites with efficient and inefficient cooling were discovered and the external flow of cooling air (24-48 m s - 1 ) was identified as the limiting factor.

Effect of wine and vinegar processing of Rhizoma Corydalis on the tissue distribution of tetrahydropalmatine, protopine and dehydrocorydaline in rats.

PubMed

Dou, Zhiying; Li, Kefeng; Wang, Ping; Cao, Liu

2012-01-18

Vinegar and wine processing of medicinal plants are two traditional pharmaceutical techniques which have been used for thousands of years in China. Tetrahydropalmatine (THP), dehydrocorydaline (DHC) and protopine are three major bioactive molecules in Rhizoma Corydalis. In this study, a simple and reliable HPLC method was developed for simultaneous analysis of THP, DHC and protopine in rat tissues after gastric gavage administration of Rhizoma Corydalis. The validated HPLC method was successfully applied to investigate the effect of wine and vinegar processing on the compounds' distribution in rat tissues. Our results showed that processing mainly affect the T(max) and mean residence time (MRT) of the molecules without changing their C(max) and AUC(0-24)( )(h) Vinegar processing significantly increased the T(max) of DHC in heart, kidney, cerebrum, cerebrellum, brain stem and striatum and prolonged the T(max) of protopine in brain. No significant changes were observed on the T(max) of THP in rat tissues after vinegar processing. Wine processing reduced the T(max) of protopine and DHC in liver and spleen and T(max) of protopine in lung, but increased the T(max) of THP in all the rat tissues examined. To our knowledge, this is the first report on the effects of processing on the tissue distribution of the bioactive molecules from Rhizoma Corydalis.

Levofloxacin pharmacokinetics in adult cystic fibrosis.

PubMed

Lee, Carlton K K; Boyle, Michael P; Diener-West, Marie; Brass-Ernst, Lois; Noschese, Michelle; Zeitlin, Pamela L

2007-03-01

Cystic fibrosis (CF) patients have enhanced renal clearance of aminoglycosides and several beta-lactams and require higher dosages. Levofloxacin is a fluoroquinolone with extensive renal elimination and enhanced penetration into lungs and Pseudomonas aeruginosa (PA) biofilms. We studied the preliminary pharmacokinetic and pharmacodynamic (PK/PD) relationship of levofloxacin in CF. Twelve patients at least 18 years old with a mild-to-moderate pulmonary exacerbation and fluoroquinolone-sensitive PA colonization received oral levofloxacin, 500 mg qd, for 14 days. Steady-state serum concentrations were collected after 3 to 7 days, and sputum samples for PA densities were collected before and after levofloxacin. PK/PD relationships for reducing PA sputum densities were evaluated. When compared to published data on non-CF patients, CF patients had similar area under the curve for 24 h (AUC(24)), total clearance, volume of distribution, maximum serum concentration (Cpmax), and elimination half-life: mean, 7.33 microg x h/mL/kg (SD, 1.70); 2.43 mL/min/kg (SD, 0.74); 1.33 L/kg (SD, 0.37); 7.06 microg/mL (SD, 2.35); and 6.44 h (SD, 1.1), respectively. Time to reach maximum serum concentration (Tmax) in CF was longer: mean, 2.20 h (SD, 0.99) vs 1.1 h (SD, 0.4) [p < 0.01]. Preliminary PK/PD analysis failed to demonstrate trends for decreasing PA sputum densities with increasing Cpmax/minimum inhibitory concentration (MIC) ratio and AUC(24)/MIC ratio. CF levofloxacin pharmacokinetics corrected for body weight are similar to non-CF, except for Tmax. Standard levofloxacin dosing (especially monotherapy) is unlikely to produce maximum therapeutic effectiveness. Additional levofloxacin studies in CF are necessary to evaluate its sputum concentrations; the benefits of higher daily dosages (>/= 750 mg); and establish PK/PD targets for managing PA pulmonary infections.

Temporal characteristics of nitric oxide-, prostaglandin-, and EDHF-mediated components of endothelium-dependent vasodilation in the kidney.

PubMed

Dautzenberg, Marcel; Just, Armin

2013-11-01

Endothelium-dependent vasodilation is mediated by nitric oxide (NO), prostaglandins (PG), and endothelium-derived hyperpolarizing factor (EDHF). We studied the contributions and temporal characteristics of these components in the renal vasodilator responses to acetylcholine (ACh) and bradykinin (BK) and in the buffering of vasoconstrictor responses to norepinephrine (NE) and angiotensin II (ANG II). Renal blood flow (RBF) and vascular conductance (RVC) were studied in anesthetized rats in response to renal arterial bolus injections before and after inhibition of NO-synthase (N(G)-nitro-L-arginine methyl ester, L-NAME), cyclooxygenase (indomethacin, INDO), or both. ACh increased RVC peaking at maximal time (tmax) = 29 s. L-NAME (n = 8) diminished the integrated response and made it substantially faster (tmax = 18 s). The point-by-point difference caused by L-NAME (= NO component) integrated to 74% of control and was much slower (tmax = 38 s). INDO (n = 9) reduced the response without affecting tmax (36 vs. 30 s). The difference (= PG) reached 21% of the control with tmax = 25 s. L-NAME+INDO (n = 17) reduced the response to 18% and markedly accelerated tmax to 16s (= EDHF). Results were similar for BK with slightly more PG and less NO contribution than for ACh. Constrictor responses to NE and ANG II were augmented and decelerated by L-NAME and L-NAME+INDO. The calculated difference (= buffering by NO or NO+PG) was slower than the constriction. It is concluded that NO, PG, and EDHF contribute >50%, 20-40%, and <20% to the renal vasodilator effect of ACh and BK, respectively. EDHF acts substantially faster and less sustained (tmax = 16 s) than NO and PG (tmax = 30 s). Constrictor buffering by NO and PG is not constant over time, but renders the constriction less sustained.

Modeling of soil nitrification responses to temperature reveals thermodynamic differences between ammonia-oxidizing activity of archaea and bacteria

PubMed Central

Taylor, Anne E; Giguere, Andrew T; Zoebelein, Conor M; Myrold, David D; Bottomley, Peter J

2017-01-01

Soil nitrification potential (NP) activities of ammonia-oxidizing archaea and bacteria (AOA and AOB, respectively) were evaluated across a temperature gradient (4–42 °C) imposed upon eight soils from four different sites in Oregon and modeled with both the macromolecular rate theory and the square root growth models to quantify the thermodynamic responses. There were significant differences in response by the dominant AOA and AOB contributing to the NPs. The optimal temperatures (Topt) for AOA- and AOB-supported NPs were significantly different (P<0.001), with AOA having Topt>12 °C greater than AOB. The change in heat capacity associated with the temperature dependence of nitrification (ΔCP‡) was correlated with Topt across the eight soils, and the ΔCP‡ of AOB activity was significantly more negative than that of AOA activity (P<0.01). Model results predicted, and confirmatory experiments showed, a significantly lower minimum temperature (Tmin) and different, albeit very similar, maximum temperature (Tmax) values for AOB than for AOA activity. The results also suggested that there may be different forms of AOA AMO that are active over different temperature ranges with different Tmin, but no evidence of multiple Tmin values within the AOB. Fundamental differences in temperature-influenced properties of nitrification driven by AOA and AOB provides support for the idea that the biochemical processes associated with NH3 oxidation in AOA and AOB differ thermodynamically from each other, and that also might account for the difficulties encountered in attempting to model the response of nitrification to temperature change in soil environments. PMID:27996979

Global quantitative indices reflecting provider process-of-care: data-base derivation.

PubMed

Moran, John L; Solomon, Patricia J

2010-04-19

Controversy has attended the relationship between risk-adjusted mortality and process-of-care. There would be advantage in the establishment, at the data-base level, of global quantitative indices subsuming the diversity of process-of-care. A retrospective, cohort study of patients identified in the Australian and New Zealand Intensive Care Society Adult Patient Database, 1993-2003, at the level of geographic and ICU-level descriptors (n = 35), for both hospital survivors and non-survivors. Process-of-care indices were established by analysis of: (i) the smoothed time-hazard curve of individual patient discharge and determined by pharmaco-kinetic methods as area under the hazard-curve (AUC), reflecting the integrated experience of the discharge process, and time-to-peak-hazard (TMAX, in days), reflecting the time to maximum rate of hospital discharge; and (ii) individual patient ability to optimize output (as length-of-stay) for recorded data-base physiological inputs; estimated as a technical production-efficiency (TE, scaled [0,(maximum)1]), via the econometric technique of stochastic frontier analysis. For each descriptor, multivariate correlation-relationships between indices and summed mortality probability were determined. The data-set consisted of 223129 patients from 99 ICUs with mean (SD) age and APACHE III score of 59.2(18.9) years and 52.7(30.6) respectively; 41.7% were female and 45.7% were mechanically ventilated within the first 24 hours post-admission. For survivors, AUC was maximal in rural and for-profit ICUs, whereas TMAX (>or= 7.8 days) and TE (>or= 0.74) were maximal in tertiary-ICUs. For non-survivors, AUC was maximal in tertiary-ICUs, but TMAX (>or= 4.2 days) and TE (>or= 0.69) were maximal in for-profit ICUs. Across descriptors, significant differences in indices were demonstrated (analysis-of-variance, P

Gd-EOB-DTPA-enhanced-MR imaging in the inflammation stage of nonalcoholic steatohepatitis (NASH) in mice.

PubMed

Yamada, Tomomi; Obata, Atsushi; Kashiwagi, Yuto; Rokugawa, Takemi; Matsushima, Shuuichi; Hamada, Tadateru; Watabe, Hiroshi; Abe, Kohji

2016-07-01

The purpose of this study is to investigate the correlation between the liver kinetics of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) and liver histopathology in a mouse model of NASH by using dynamic contrast-enhanced MRI. Twenty male C57/BL6 mice aged 8weeks were fed a methionine-choline-deficient (MCD) diet for 2, 4 and 6weeks (MCD groups: MCD 2w, 4w, or 6w). Gd-EOB-DTPA-enhanced MR imaging of the liver was performed at 2, 4 and 6weeks after the MCD feeding. The signal intensity of the liver was obtained from dynamic MR images and relative enhancement (RE), and the time to maximum RE (Tmax) and half-life of elimination RE (T1/2) were calculated. After MRI scan, histopathological scores of hepatic steatosis and inflammation and blood biochemistry data, such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, were obtained. Plasma AST and ALT levels were significantly increased in mice fed MCD. Histopathological scores indicated that steatohepatitis progressed with the MCD feeding period from 2 to 6weeks, but significant fibrosis was observed only in mice fed MCD for 6weeks. Gd-EOB-DTPA-enhanced MRI showed that Tmax was significantly prolonged in the livers of the 6-week group compared to the control group (control, 4.0±0.7min; MCD 6w, 12.1±1.6min), although there was no alteration in the 2- and 4-week groups. T1/2 was significantly prolonged in mice fed MCD for 4 and 6weeks compared to the control group (control, 19.9±2.0min; MCD 4w, 46.7±8.7min; MCD 6w, 65.4±8.8min). The parameters of Gd-EOB-DTPA kinetics (Tmax and T1/2) in the liver were positively correlated with the liver histopathological score (steatosis vs Tmax, rho=0.69, P=0.0007; inflammation vs Tmax, rho=0.66, P=0.00155; steatosis vs T1/2, rho=0.77, P<0.0001; inflammation vs T1/2, rho=0.73, P=0.0003). The liver kinetics of Gd-EOB-DTPA correlated well with the inflammation score in the mouse model of NASH, suggesting the possibility of detecting the steatohepatitis stage without fibrosis by Gd-EOB-DTPA-enhanced MR imaging. Copyright © 2016 Elsevier Inc. All rights reserved.

Observed and Simulated Urban Heat Island and Urban Cool Island in Las Vegas

NASA Astrophysics Data System (ADS)

Sauceda, Daniel O.

This research investigates the urban climate of Las Vegas and establishes long-term trends relative to the regional climate in an attempt to identify climate disturbances strictly related to urban growth. An experimental surface station network (DRI-UHI) of low-cost surface temperature (T2m) and relative humidity (RH) sensors were designed to cover under-sampled low-intensity residential urban areas, as well as complement the in-city and surrounding rural areas. In addition to the analysis of the surface station data, high-resolution gridded data products (GDPs) from Daymet (1km) and PRISM (800 m) and results from numerical simulations were used to further characterize the Las Vegas climate trends. The Weather Research and Forecasting (WRF) model was coupled with three different models: the Noah Land Surface Model (LSM) and a single- and multi-layer urban canopy model (UCM) to assess the urban related climate disturbances; as well as the model sensitivity and ability to characterize diurnal variability and rural/urban thermal contrasts. The simulations consisted of 1 km grid size for five, one month-long hindcast simulations during November of 2012: (i) using the Noah LSM without UCM treatment, (ii) same as (i) with a single-layer UCM (UCM1), (iii) same as (i) with a multi-layer UCM (UCM2), (iv) removing the City of Las Vegas (NC) and replacing it with predominant land cover (shrub), and (v) same as (ii) with increasing the albedo of rooftops from 0.20 to 0.65 as a potential adaptation scenario known as "white roofing". T2m long-term trends showed a regional warming of minimum temperatures (Tmin) and negligible trends in maximum temperatures (Tmax ). By isolating the regional temperature trends, an observed urban heat island (UHI) of ~1.63°C was identified as well as a daytime urban cool island (UCI) of ~0.15°C. GDPs agree with temperature trends but tend to underpredict UHI intensity by ~1.05°C. The WRF-UCM showed strong correlations with observed T2m (0.85 < rho < 0.95) and vapor pressure (ea ; 0.83 < rho < 0.88), and moderate-to-strong correlations for RH (0.64 < rho < 0.81) at the 95% confidence level. UCM1 shows the best skill and adequately simulates most of the UHI and UCI observed characteristics. Differences of LSM, UCM1, and UCM2 minus NC show simulated effects of warmer in-city Tmin for LSM and UCM2, and cooler in-city Tmax for UCM1 and UCM2. Finally, the white roofing scenario for Las Vegas was not found to significantly impact the UHI effect but has the potential to reduce daytime temperature by 1°-2°C.

Bioclimatic Thresholds, Thermal Constants and Survival of Mealybug, Phenacoccus solenopsis (Hemiptera: Pseudococcidae) in Response to Constant Temperatures on Hibiscus

PubMed Central

Sreedevi, Gudapati; Prasad, Yenumula Gerard; Prabhakar, Mathyam; Rao, Gubbala Ramachandra; Vennila, Sengottaiyan; Venkateswarlu, Bandi

2013-01-01

Temperature-driven development and survival rates of the mealybug, Phenacoccussolenopsis Tinsley (Hemiptera: Pseudococcidae) were examined at nine constant temperatures (15, 20, 25, 27, 30, 32, 35 and 40°C) on hibiscus ( Hibiscus rosa -sinensis L.). Crawlers successfully completed development to adult stage between 15 and 35°C, although their survival was affected at low temperatures. Two linear and four nonlinear models were fitted to describe developmental rates of P . solenopsis as a function of temperature, and for estimating thermal constants and bioclimatic thresholds (lower, optimum and upper temperature thresholds for development: Tmin, Topt and Tmax, respectively). Estimated thresholds between the two linear models were statistically similar. Ikemoto and Takai’s linear model permitted testing the equivalence of lower developmental thresholds for life stages of P . solenopsis reared on two hosts, hibiscus and cotton. Thermal constants required for completion of cumulative development of female and male nymphs and for the whole generation were significantly lower on hibiscus (222.2, 237.0, 308.6 degree-days, respectively) compared to cotton. Three nonlinear models performed better in describing the developmental rate for immature instars and cumulative life stages of female and male and for generation based on goodness-of-fit criteria. The simplified β type distribution function estimated Topt values closer to the observed maximum rates. Thermodynamic SSI model indicated no significant differences in the intrinsic optimum temperature estimates for different geographical populations of P . solenopsis . The estimated bioclimatic thresholds and the observed survival rates of P . solenopsis indicate the species to be high-temperature adaptive, and explained the field abundance of P . solenopsis on its host plants. PMID:24086597

Evaluation of efficiency of insulin suppository formulations containing sodium salicylate or sodium cholate in insulin dependent diabetic patients.

PubMed

Hosny, Ehab A; Al-Marzouki, Zohair M H; Metwally, Mohammed E S; Souaida, Mamdouh Y S; Alshaik, Abdel Rhman A M

2003-10-01

Two formulations of insulin suppositories were prepared to contain different amounts of sodium salicylate and sodium cholate as absorption promoters and also of insulin with the purpose of obtaining the most effective formulation in reducing plasma glucose levels after rectal administration to diabetic patients. The results show that insulin suppositories containing 100 mg sodium salicylate and 100 or 200 U of crystalline insulin showed no significant difference in AUC, Cmax and Tmax and both formulations showed significant reduction in plasma glucose level compared to initial values within 1.5-2 h. The results from experiments carried out in health volunteers showed that 100 mg sodium salicylate is the optimum amount to be included in insulin suppositories producing significantly higher Cmax and AUC compared to those produced after rectal administration of insulin suppositories containing 50 or 200 mg sodium salicylate. The results also show that using sodium cholate in 50 mg amount did not produce any significant reduction in plasma glucose levels of insulin dependent diabetic patients given suppositories containing 100 U of insulin, but this amount in suppositories containing 200 U of insulin was able to produce significant (p < 0.05) reduction in plasma glucose level within 1 h which lasted till end of experiment producing Cmax of 29.7 +/- 6.61% at Tmax of 1.5 +/- 0.61 h. On increasing the amount of sodium cholate to 100 mg in the suppositories, a marked (p < 0.01) reduction in plasma glucose level took place and the Cmax increased to 47.7 +/- 12.24% at Tmax of 1.5 +/- 0.63 h. This resulted in AUC of 86.7 +/- 22.4 mg%h which was non significantly higher from that produced after administration of suppositories containing 50 mg sodium cholate and 200 U insulin (62.5 +/- 17.6 mg%h). The results also show that insulin suppositories containing 100 mg sodium cholate and 200 U insulin resulted in a non significant differences in Cmax and AUC from those produced by S.C. injection of insulin (20 U) but significantly (p < 0.001) shorter Tmax. This formulation also shows non significant differences in Tmax and AUC and significantly (p < 0.05) higher Cmax than from those produced after rectal administration of suppositories containing 100 mg of sodium salicylate and same amount of insulin. Further more this formulation produced severe hypoglycemia in control healthy volunteers within 1 h of administration producing Cmax of 57.0 +/- 18.8% at Tmax of 0.75 +/- 0.35 h. The results of this study showed that the formulation containing 100 mg of sodium cholate and 200 U of insulin tested in fasted insulin dependent diabetic patients produced a maximum % reduction in plasma glucose levels (Cmax) of 47.7 +/- 12.24% at tmax of 1.5 +/- 0.63 h compared to Cmax of 50.56 +/- 6.8% at tmax of 2.93 +/- 0.19 h resulted after subcutaneous injection of 20 U insulin. These suppositories produced an area under the curve (AUC) of 87 +/- 22.4 mg%h compared to an AUC of 81 +/- 13.4 mg%h obtained after subcutaneous injection. This formulation of suppositories studied in 7 insulin dependent diabetic patients was found to abolish the 2-h post-prandial significant rise in plasma glucose levels after meal. These results show that these insulin suppositories containing 100 mg of sodium cholate and 200 U of insulin can serve as effective buffer against meal related hyperglycemia. The suppositories were safe, effective, accepted and well tolerated by the tested individuals.

Productivity and some properties of egg yolk antibody (IgY) against human rotavirus compared with rabbit IgG.

PubMed

Hatta, H; Tsuda, K; Akachi, S; Kim, M; Yamamoto, T

1993-03-01

Productivity and some properties of anti-Human Rotavirus (HRV) hen egg yolk antibody (IgY) were compared with those of anti-HRV rabbit serum antibody (IgG). The hens immunized with HRV (Wa strain, serotype 1 and Mo strain, serotype 3) were found to continuously to lay eggs without any change in the egg laying rate and the yolk of the eggs laid over a year showed a high level of neutralization titer against HRV. The production of anti-HRV IgY by a hen (one year) was at least 15 times (anti-Wa) and 120 times (anti-Mo) more effective than those by an immunized rabbit in the neutralization titer of the antibodies. The stability of anti-HRV IgY at temperature above 70 degrees C and low pH 2-3 was less than that of anti-HRV rabbit IgG. The temperature corresponding to the maximum of denaturation endotherm (Tmax) of IgY was 73.9 degrees C while that of rabbit IgG was 77.0 degrees C in the analysis by differential scanning calorimetry. This discrepancy in heat and acidic pH stability found between the two antibodies as discussed with regard to their protein structures.

Effect of heating rate on thermal cracking characteristics and kinetics of Xinjiang oil sand bitumen by TG-FTIR

NASA Astrophysics Data System (ADS)

Hao, Junhui; Zhang, Jinhong; Qiao, Yingyun; Tian, Yuanyu

2017-08-01

This work was aimed to investigate effects of heating rate on thermal cracking behaviors, distribution of gaseous products and activation energy of the thermal cracking process of Xinjiang oil sand bitumen (OSB). The thermal cracking experiments of Xinjiang OSB were performed by using thermogravimetric analyzer (TGA) at various heating rates of 10, 20, 50, 80 and 120 K/min. The evolving characteristic of gaseous products produced from the thermal cracking process was evaluated by the Fourier transform infrared spectrometry (FTIR) connected with TG. The kinetic parameters of the thermal cracking process of Xinjiang OSB at each of heating rate were determined by the Coats-Redfern model. The result show that the temperature intervals of DE volatilization stage and main reaction stage, the ((dw/dt) max and Tmax in thermal cracking process of Xinjiang OSB all increased with the increasing heating rate. While the heating rate has not obvious effect on the coke yield of Xinjiang OSB. Furthermore, the maximum absorbance of gaseous products and corresponding temperature became larger as the heating rate increases. The activation energy of this two stage both presented increasing trend with the rising heating rate, while the increasing content of that of DE volatilization stage was weaker compared to that of main reaction stage.

[Effects of PASP-KT-NAA on the grain-filling of maize in different accumulated temperature zones of Hilongjiang Province, Norheast China].

PubMed

Xu, Tian-Jun; Dong, Zhi-Qiang; Gao, Jiao; Chen, Chuan-Xiao; Jiao, Liu; Xie, Zhen-Xing

2013-02-01

Taking the two maize varieties Zhengdan 958 and Fengdan 3 grown on the three accumulated temperature zones (I, II and III) in Heilongjiang Provice as test materials, a field investigation was made in 2010 and 2011 to study the effects of PASP-KT-NAA (PKN), a compound of exogenous plant growth regulators, on the grain filling and yield of the varieties under different environmental temperatures. From zone I to III, the air temperature at the grain filling stage had a decreasing trend, with the average minimum temperature being 12.16, 11.40, and 9.56, respectively. The effective accumulated temperature at the mid-ate amt sae stage of grain filling was too low to be sufficient for grain filling, which severely affected the grain filling process. Applying N, P and K promoted the dry matter accumulation of maize grain and the grain filling rate in the three zones, delayed the peak time (Tmax) of the grain filling rate of Fengdan 3 but advanced that of Zhengdan 958, promoted the growth capacity at peak time of grain filling rate and the maximum grain filling rate of the two varieties, and shortened their active grain filling period. Applying N, P, and K increased the grain yield of the two varieties in the three zones obviously, and, as compared with those in zones I and II , the grain yields of Zhengdan 958 and Fengdan 3 in zone III were increased by 8.2% and 5.1% , and 3.4% and 0.8% , respectively. Therefore, applying N, P and K could help maize utilizing the limited accumulation temperature, improve the grain filling rate, decrease the grain water content, and ultimately, increase the maize yield.

Climate change impacts on rainfall and temperature in sugarcane growing Upper Gangetic Plains of India

NASA Astrophysics Data System (ADS)

Verma, Ram Ratan; Srivastava, Tapendra Kumar; Singh, Pushpa

2018-01-01

Assessment of variability in climate extremes is crucial for managing their aftermath on crops. Sugarcane (Saccharum officinarum L.), a major C4 crop, dominates the Upper Gangetic Plain (UGP) in India and is vulnerable to both direct and indirect effects of changes in temperature and rainfall. The present study was taken up to assess the weekly, monthly, seasonal, and annual trends of rainfall and temperature variability during the period 1956-2015 (60 years) for envisaging the probabilities of different levels of rainfall suitable for sugarcane in UGP in the present climate scenario. The analysis revealed that 87% of total annual rainfall was received during southwest monsoon months (June-September) while post-monsoon (October to February) and pre-monsoon months (March-May) accounted for only 9.4 and 3.6%, respectively. There was a decline in both monthly and annual normal rainfall during the period 1986-2015 as compared to 1956-1985, and an annual rainfall deficiency of 205.3 mm was recorded. Maximum monthly normal rainfall deficiencies of 52.8, 84.2, and 54.0 mm were recorded during the months of July, August, and September, respectively, while a minimum rainfall deficiency of 2.2 mm was observed in November. There was a decline by 196.3 mm in seasonal normal rainfall during June-September (kharif). The initial probability of a week going dry was higher (> 70%) from the 1st to the 25th week; however, standard meteorological weeks (SMW) 26 to 37 had more than 50% probability of going wet. The normal annual maximum temperature (Tmax) decreased by 0.4 °C while normal annual minimum temperatures (Tmin) increased by 0.21 °C. Analysis showed that there was an increase in frequency of drought from 1986 onwards in the zone and a monsoon rainfall deficit by about 21.25% during June-September which coincided with tillering and grand growth stage of sugarcane. The imposed drought during the growth and elongation phase is emerging as a major constraint in realizing high cane productivity in the zone. Strategies for mitigating the negative impacts of rainfall and temperature variability on sugarcane productivity through improvement in existing adaptation strategies are proposed.

RM-DEMATEL: a new methodology to identify the key factors in PM2.5.

PubMed

Chen, Yafeng; Liu, Jie; Li, Yunpeng; Sadiq, Rehan; Deng, Yong

2015-04-01

Weather system is a relative complex dynamic system, the factors of the system are mutually influenced PM2.5 concentration. In this paper, a new method is proposed to quantify the influence on PM2.5 by other factors in the weather system and identify the most important factors for PM2.5 with limited resources. The relation map (RM) is used to figure out the direct relation matrix of 14 factors in PM2.5. The decision making trial and evaluation laboratory(DEMATEL) is applied to calculate the causal relationship and extent to a mutual influence of 14 factors in PM2.5. According to the ranking results of our proposed method, the most important key factors is sulfur dioxide (SO2) and nitrogen oxides (NO(X)). In addition, the other factors, the ambient maximum temperature (T(max)), concentration of PM10, and wind direction (W(dir)), are important factors for PM2.5. The proposed method can also be applied to other environment management systems to identify key factors.

Solid lipid nanoparticles for nose to brain delivery of haloperidol: in vitro drug release and pharmacokinetics evaluation

PubMed Central

Yasir, Mohd; Sara, Udai Vir Singh

2014-01-01

In the present study, haloperidol (HP)-loaded solid lipid nanoparticles (SLNs) were prepared to enhance the uptake of HP to brain via intranasal (i.n.) delivery. SLNs were prepared by a modified emulsification–diffusion technique and evaluated for particle size, zeta potential, drug entrapment efficiency, in vitro drug release, and stability. All parameters were found to be in an acceptable range. In vitro drug release was found to be 94.16±4.78% after 24 h and was fitted to the Higuchi model with a very high correlation coefficient (R2=0.9941). Pharmacokinetics studies were performed on albino Wistar rats and the concentration of HP in brain and blood was measured by high performance liquid chromatography. The brain/blood ratio at 0.5 h for HP-SLNs i.n., HP sol. i.n. and HP sol. i.v. was 1.61, 0.17 and 0.031, respectively, indicating direct nose-to-brain transport, bypassing the blood–brain barrier. The maximum concentration (Cmax) in brain achieved from i.n. administration of HP-SLNs (329.17±20.89 ng/mL, Tmax 2 h) was significantly higher than that achieved after i.v. (76.95±7.62 ng/mL, Tmax 1 h), and i.n. (90.13±6.28 ng/mL, Tmax 2 h) administration of HP sol. The highest drug-targeting efficiency (2362.43%) and direct transport percentage (95.77%) was found with HP-SLNs as compared to the other formulations. Higher DTE (%) and DTP (%) suggest that HP-SLNs have better brain targeting efficiency as compared to other formulations. PMID:26579417

Nondairy creamer, but not milk, delays the appearance of coffee phenolic acid equivalents in human plasma.

PubMed

Renouf, Mathieu; Marmet, Cynthia; Guy, Philippe; Fraering, Anne-Lise; Longet, Karin; Moulin, Julie; Enslen, Marc; Barron, Denis; Cavin, Christophe; Dionisi, Fabiola; Rezzi, Serge; Kochhar, Sunil; Steiling, Heike; Williamson, Gary

2010-02-01

Chlorogenic acids (CGA) are antioxidants found in coffee. They are becoming of interest for their health-promoting effects, but bioavailability in humans is not well understood. We hypothesized that adding whole milk or sugar and nondairy creamer to instant coffee might modulate the bioavailability of coffee phenolics. Nine healthy participants were asked to randomly drink, in a crossover design, instant coffee (Coffee); instant coffee and 10% whole milk (Milk); or instant coffee, sugar, and nondairy creamer already premixed (Sugar/NDC). All 3 treatments provided the same amount of total CGA (332 mg). Blood was collected for 12 h after ingestion and plasma samples treated using a liquid-liquid extraction method that included a full enzymatic cleavage to hydrolyze all CGA and conjugates into phenolic acid equivalents. Hence, we focused our liquid chromatography-Electrospray ionization-tandem MS detection and quantification on caffeic acid (CA), ferulic acid (FA), and isoferulic acid (iFA) equivalents. Compared with a regular black instant coffee, the addition of milk did not significantly alter the area under the curve (AUC), maximum plasma concentration (C(max)), or the time needed to reach C(max) (T(max)). The C(max) of CA and iFA were significantly lower and the T(max) of FA and iFA significantly longer for the Sugar/NDC group than for the Coffee group. However, the AUC did not significantly differ. As a conclusion, adding whole milk did not alter the overall bioavailability of coffee phenolic acids, whereas sugar and nondairy creamer affected the T(max) and C(max) but not the appearance of coffee phenolics in plasma.

Bioequivalence assessment of ambroxol tablet after a single oral dose administration to healthy male volunteers.

PubMed

Lee, Hee Joo; Joung, Sun Koung; Kim, Yoon Gyoon; Yoo, Jeong-Yeon; Han, Sang Beom

2004-01-01

A bioequivalence study of the ambroxol hydrochloride tablets was conducted. Twenty-four healthy male Korean volunteers received each medicine at the ambroxol hydrochloride dose of 30 mg in a 2 x 2 cross-over study. There was a 1-week washout period between the doses. Plasma concentrations of ambroxol were monitored by a high-performance liquid chromatography (HPLC) for over a period of 24h after the administration. AUC(t) (the area under the plasma concentration-time curve from time 0 to last sampling time, 24h) was calculated by the linear-log trapezoidal rule method. C(max) (maximum plasma drug concentration) and T(max) (time to reach C(max)) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed AUC(t) and C(max), and untransformed T(max). The geometric mean of AUC(t) was 495.8 ng ml(-1)h(-1) (test medication) and 468.3 ng ml(-1)h(-1) (reference medication). C(max) of 61.5 and 57.3 ng ml(-1) were achieved for the test and the reference medication, respectively. The point estimates and 90% confidence intervals for AUC(t) (parametric) and C(max) (parametric) were, in point estimate (90% confidence interval), 1.058 (0.989-1.134) and 1.073 (1.007-1.142), respectively, satisfying the bioequivalence criteria of the European Committee for Proprietary Medicinal Products and the US Food and Drug Administration Guidelines. The corresponding value of T(max) was 0.229 (0.015-0.444). These results indicate that the two medications of ambroxol hydrochloride are bioequivalent and, thus, may be prescribed interchangeably.

Absorption of phenytoin from rectal suppositories formulated with a polyethylene glycol base.

PubMed

Burstein, A H; Fisher, K M; McPherson, M L; Roby, C A

2000-05-01

To compare phenytoin pharmacokinetics following administration of an oral suspension and a rectal suppository formulated with a polyethylene glycol base. Unblinded, single-dose, randomized, crossover trial. University-affiliated pharmacokinetics and biopharmaceutics laboratory. Six healthy subjects. Subjects were given a single 200-mg dose of phenytoin as an oral suspension and a rectal suppository separated by a 1-week washout. Blood for plasma phenytoin concentrations was obtained at baseline and 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 hours after administration. Plasma was analyzed by high-performance liquid chromatography (coefficient of variation < 6%) for total phenytoin concentration. Phenytoin maximum concentration (Cmax), time to Cmax (Tmax), time to first measurable concentration (Tlag), and area under the curve from time zero to time of last measurable concentration (AUClast) were estimated for oral and rectal administration by WinNonlin (v 1.1) and compared using Wilcoxon's signed rank test (p<0.05 for statistical significance). Two subjects did not have detectable plasma phenytoin concentrations after rectal administration. For the other four subjects, median rectal Cmax was significantly lower than oral Cmax (0.4 vs 1.9 microg/ml, p=0.028), median rectal Tmax did not differ from oral Tmax (11.9 vs 8.0 hrs, p=0.465), and median rectal AUClast, although highly variable, was significantly lower than oral AUClast (5.4 vs 36.2 microg x hr/ml, p=0.046). No Tlag was seen after oral administration, but with rectal administration the median Tlag was 2 hours. The estimated relative bioavailability of rectal phenytoin suppositories based on AUC0-24 was 4.7%, with individual values ranging from 0-58.3%. It appears that absorption of phenytoin from polyethylene glycol rectal suppositories in healthy subjects is highly variable and unpredictable. Thus this formulation is not recommended.

Pulmonary disposition and pharmacokinetics of minocycline in adult horses.

PubMed

Echeverria, Kate O; Lascola, Kara M; Giguère, Steeve; Foreman, Jonathan H; Austin, Scott A

2017-11-01

OBJECTIVE To determine pharmacokinetics and pulmonary disposition of minocycline in horses after IV and intragastric administration. ANIMALS 7 healthy adult horses. PROCEDURES For experiment 1 of the study, minocycline was administered IV (2.2 mg/kg) or intragastrically (4 mg/kg) to 6 horses by use of a randomized crossover design. Plasma samples were obtained before and 16 times within 36 hours after minocycline administration. Bronchoalveolar lavage (BAL) was performed 4 times within 24 hours after minocycline administration for collection of pulmonary epithelial lining fluid (PELF) and BAL cells. For experiment 2, minocycline was administered intragastrically (4 mg/kg, q 12 h, for 5 doses) to 6 horses. Plasma samples were obtained before and 20 times within 96 hours after minocycline administration. A BAL was performed 6 times within 72 hours after minocycline administration for collection of PELF samples and BAL cells. RESULTS Mean bioavailability of minocycline was 48% (range, 35% to 75%). At steady state, mean ± SD maximum concentration (Cmax) of minocycline in plasma was 2.3 ± 1.3 μg/mL, and terminal half-life was 11.8 ± 0.5 hours. Median time to Cmax (Tmax) was 1.3 hours (interquartile range [IQR], 1.0 to 1.5 hours). The Cmax and Tmax of minocycline in the PELF were 10.5 ± 12.8 μg/mL and 9.0 hours (IQR, 5.5 to 12.0 hours), respectively. The Cmax and Tmax for BAL cells were 0.24 ± 0.1 μg/mL and 6.0 hours (IQR, 0 to 6.0 hours), respectively. CONCLUSIONS AND CLINICAL RELEVANCE Minocycline was distributed into the PELF and BAL cells of adult horses.

An easy-to-use approach for determining the disintegration ability of disintegrants by analysis of available surface area.

PubMed

Iwao, Yasunori; Tanaka, Shoko; Uchimoto, Takeaki; Noguchi, Shuji; Itai, Shigeru

2013-05-01

With the aim of directly predicting the functionality and mechanism of disintegrants during the disintegration and dissolution of tablets, we investigated an analysis method based on available surface area, which is the surface area of a drug in a formulation in direct contact with the external solvent during dissolution. We evaluated the following disintegrants in this study: sodium starch glycolate (Glycolys), crospovidone (Kollidon CL), carboxymethylcellulose calcium (CMC-Ca), low-substituted hydroxypropylcellulose (L-HPC), and croscarmellose sodium (Ac-Di-Sol). When disintegrant was added to a 50% ethenzamide tablet formulation, an increase in the dissolution rate dependent on disintegrant concentration was observed, according to the type of disintegrant. In addition, the available surface area also differed between disintegrants. For Glycolys, CMC-Ca, and Ac-Di-Sol, a rapid increase in available surface area and a large increase in maximum available surface area (Smax) were observed due to high swellability and wicking, even when the disintegrant concentration was only 1.0%. In contrast, for Kollidon CL and LH-21, a gradual increase in available surface area was observed, depending on the disintegrant concentration. To evaluate the disintegrant ability, Δtmax and ΔSmax were calculated by subtracting peak time (tmax) at 5.0% from that at 1.0% and subtracting Smax at 1.0% from that at 5.0%, respectively, and it was found that the water absorption ratio had strong negative correlations with Δtmax and ΔSmax. Therefore, this study demonstrates that analysis of only available surface area and parameters thereby obtained can directly provide useful information, especially about the disintegration ability of disintegrants. Copyright © 2013 Elsevier B.V. All rights reserved.

Development and application of Geobacillus stearothermophilus growth model for predicting spoilage of evaporated milk.

PubMed

Kakagianni, Myrsini; Gougouli, Maria; Koutsoumanis, Konstantinos P

2016-08-01

The presence of Geobacillus stearothermophilus spores in evaporated milk constitutes an important quality problem for the milk industry. This study was undertaken to provide an approach in modelling the effect of temperature on G. stearothermophilus ATCC 7953 growth and in predicting spoilage of evaporated milk. The growth of G. stearothermophilus was monitored in tryptone soy broth at isothermal conditions (35-67 °C). The data derived were used to model the effect of temperature on G. stearothermophilus growth with a cardinal type model. The cardinal values of the model for the maximum specific growth rate were Tmin = 33.76 °C, Tmax = 68.14 °C, Topt = 61.82 °C and μopt = 2.068/h. The growth of G. stearothermophilus was assessed in evaporated milk at Topt in order to adjust the model to milk. The efficiency of the model in predicting G. stearothermophilus growth at non-isothermal conditions was evaluated by comparing predictions with observed growth under dynamic conditions and the results showed a good performance of the model. The model was further used to predict the time-to-spoilage (tts) of evaporated milk. The spoilage of this product caused by acid coagulation when the pH approached a level around 5.2, eight generations after G. stearothermophilus reached the maximum population density (Nmax). Based on the above, the tts was predicted from the growth model as the sum of the time required for the microorganism to multiply from the initial to the maximum level ( [Formula: see text] ), plus the time required after the [Formula: see text] to complete eight generations. The observed tts was very close to the predicted one indicating that the model is able to describe satisfactorily the growth of G. stearothermophilus and to provide realistic predictions for evaporated milk spoilage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Variability of Winter Air Temperature in Mid-Latitude Europe

NASA Technical Reports Server (NTRS)

Otterman, J.; Ardizzone, J.; Atlas, R.; Bungato, D.; Cierniewski, J.; Jusem, J. C.; Przybylak, R.; Schubert, S.; Starr, D.; Walczewski, J.

2002-01-01

The aim of this paper is to report extreme winter/early-spring air temperature (hereinafter temperature) anomalies in mid-latitude Europe, and to discuss the underlying forcing to these interannual fluctuations. Warm advection from the North Atlantic in late winter controls the surface-air temperature, as indicated by the substantial correlation between the speed of the surface southwesterlies over the eastern North Atlantic (quantified by a specific Index Ina) and the 2-meter level air temperatures (hereinafter Ts) over Europe, 45-60 deg N, in winter. In mid-March and subsequently, the correlation drops drastically (quite often it is negative). This change in the relationship between Ts and Ina marks a transition in the control of the surface-air temperature: absorption of insolation replaces the warm advection as the dominant control. This forcing by maritime-air advection in winter was demonstrated in a previous publication, and is re-examined here in conjunction with extreme fluctuations of temperatures in Europe. We analyze here the interannual variability at its extreme by comparing warm-winter/early-spring of 1989/90 with the opposite scenario in 1995/96. For these two December-to-March periods the differences in the monthly mean temperature in Warsaw and Torun, Poland, range above 10 C. Short-term (shorter than a month) fluctuations of the temperature are likewise very strong. We conduct pentad-by-pentad analysis of the surface-maximum air temperature (hereinafter Tmax), in a selected location, examining the dependence on Ina. The increased cloudiness and higher amounts of total precipitable water, corollary effects to the warm low-level advection. in the 1989/90 winter, enhance the positive temperature anomalies. The analysis of the ocean surface winds is based on the Special Sensor Microwave/Imager (SSM/I) dataset; ascent rates, and over land wind data are from the European Centre for Medium-Range Weather Forecasts (ECMWF); maps of 2-m temperature, cloud cover and precipitable water are from the National Centers for Environmental Prediction (NCEP) Reanalysis.

Glacial influence and stream macroinvertebrate biodiversity under climate change: Lessons from the Southern Alps.

PubMed

Lencioni, Valeria

2018-05-01

The aim of this work was to highlight the main ecological predictors driving invertebrate distribution in eight glacier-fed streams in the Southern Alps. Thirty-five sites belonging to four stream types were sampled monthly during the ablation season of one, two or three years between 1996 and 2014. Taxa from glacial (kryal and glacio-rhithral) and non-glacial (kreno-rhithral and lake outlet) sites were separated by canonical correspondence analysis (CCA) along a glacial influence gradient and a hydrological-altitudinal gradient. High glacial influence was associated mainly with low maximum water temperature (Tmax), high Glacial Index (calculated as a function of glacier area and distance from the glacier), and the abundance of Diamesa species (D. steinboecki, D. goetghebueri, D. zernyi, and D. latitarsis). Change-point analysis and Threshold Indicator Taxa Analysis confirmed the CCA results in identifying these Diamesa species as the taxa with the strongest preference for high percent glacier cover in the catchment (change point~30%) and low Tmax (change point~6°C). Temporal changes in community structure were highlighted in seven sites fed by glaciers under different retreat rates. Where the rate was faster and the remaining glacier smaller (≪1km 2 ), the most cold-stenothermal kryal inhabitant, D. steinboecki, almost disappeared or survived only as brachypterous populations, whereas other Diamesinae (Pseudokiefferiella parva), Orthocladiinae (e.g. Eukiefferiella, Orthocladius), Limoniidae, Baetidae, Nemouridae, and non-insect taxa (e.g. Oligochaeta, Hydracarina) became more abundant. Upstream migration was observed in Diamesa spp. which conquered new stream reaches left free by the retreating glacier, and euriecious taxa which colonized reaches with ameliorated environmental conditions, no longer the exclusive habitat of Diamesa spp. Co-occurrence of stochastic and deterministic assembly processes seem to drive spatio-temporal changes in these invertebrate communities. Long-term ecological studies on the adaptive biology of kryal species will be useful to predict the fate of Alpine biodiversity. Copyright © 2017 Elsevier B.V. All rights reserved.

Collapse of a nanoscopic void triggered by a spherically symmetric traveling sound wave.

PubMed

Hołyst, Robert; Litniewski, Marek; Garstecki, Piotr

2012-05-01

Molecular-dynamics simulations of the Lennard-Jones fluid (up to 10(7) atoms) are used to analyze the collapse of a nanoscopic bubble. The collapse is triggered by a traveling sound wave that forms a shock wave at the interface. The peak temperature T(max) in the focal point of the collapse is approximately ΣR(0)(a), where Σ is the surface density of energy injected at the boundary of the container of radius R(0) and α ≈ 0.4-0.45. For Σ = 1.6 J/m(2) and R(0) = 51 nm, the shock wave velocity, which is proportional to √Σ, reaches 3400 m/s (4 times the speed of sound in the liquid); the pressure at the interface, which is proportional to Σ, reaches 10 GPa; and T(max) reaches 40,000 K. The Rayleigh-Plesset equation together with the time of the collapse can be used to estimate the pressure at the front of the shock wave.

An approach to get thermodynamic properties from speed of sound

NASA Astrophysics Data System (ADS)

Núñez, M. A.; Medina, L. A.

2017-01-01

An approach for estimating thermodynamic properties of gases from the speed of sound u, is proposed. The square u2, the compression factor Z and the molar heat capacity at constant volume C V are connected by two coupled nonlinear partial differential equations. Previous approaches to solving this system differ in the conditions used on the range of temperature values [Tmin,Tmax]. In this work we propose the use of Dirichlet boundary conditions at Tmin, Tmax. The virial series of the compression factor Z = 1+Bρ+Cρ2+… and other properties leads the problem to the solution of a recursive set of linear ordinary differential equations for the B, C. Analytic solutions of the B equation for Argon are used to study the stability of our approach and previous ones under perturbation errors of the input data. The results show that the approach yields B with a relative error bounded basically by that of the boundary values and the error of other approaches can be some orders of magnitude lager.

Spatio-temporal variability of vertical gradients of major meteorological observations around the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Guo, X.; Wang, L.; Tian, L.

2015-12-01

The near-surface air temperature lapse rate (TLR), wind speed gradient (WSG), and precipitation gradient (PG) provide crucial parameters used in models of mountain climate and hydrology. The complex mountain terrain and vast area of the Tibetan Plateau (TP) make such factors particularly important. With daily data from 161 meteorological stations over the past 43 years (1970-2012), we analyse the spatio-temporal variations of TLRs, WSGs, and PGs over and around TP, derived using linear regression methods and dividing the study area into zones based on spatial variations. Results of this study include: (1) The observed TLR varies from -0.46 to -0.73 ∘C (100 m) -1, with averaged TLRs of -0.60,-0.62, and -0.59 ∘C (100 m) -1 for Tmax, Tmin,and Tmean , respectively. The averaged TLR is slightly less than the global mean of -0.65 ∘C (100 m) -1 . The spatial variability of TLR relates to climate conditions, wherein the TLR increases in dry conditions and in cold months (October-April), while it lessens in humid regions and during warm months (May-September). (2) The estimated annual WSG ranges from 0.07 to 0.17m s -1 (100 m) -1. Monthly WSGs show a marked seasonal shift, in which higher WSGs can be explained by the high intensity of prevailing wind. (3) Positive summer PGs vary from 12.08 in the central TP to 26.14 mm (100 m) -1 in northeastern Qinghai and the southern TP, but a reverse gradient prevails in Yunnan and parts of Sichuan Province. (4) The regional warming over TP is more evident in winter, and Tmin demonstrated the most prominent warming compared with Tmax and Tmean. Environments at high elevations experience more rapid changes in temperatures (Tmax, Tmin,and Tmean) than those at low elevations, which is especially true in winter and for Tmin. Furthermore, inter-annual variation of TLRs is linked to elevation-dependent warming.

Tables of the Inverse Laplace Transform of the Function e−sβ

PubMed Central

Dishon, Menachem; Bendler, John T.; Weiss, George H.

1990-01-01

The inverse transform, g(t)=L−1(e−sβ), 0 < β < 1, is a stable law that arises in a number of different applications in chemical physics, polymer physics, solid-state physics, and applied mathematics. Because of its important applications, a number of investigators have suggested approximations to g(t). However, there have so far been no accurately calculated values available for checking or other purposes. We present here tables, accurate to six figures, of g(t) for a number of values of β between 0.25 and 0.999. In addition, since g(t), regarded as a function of β, is uni-modal with a peak occurring at t = tmax we both tabulate and graph tmax and 1/g(tmax) as a function of β, as well as giving polynomial approximations to 1/g(tmax). PMID:28179785

Comparative single-dose pharmacokinetics of clonazepam following intravenous, intramuscular and oral administration to healthy volunteers.

PubMed

Crevoisier, C; Delisle, M C; Joseph, I; Foletti, G

2003-01-01

The objective was to assess the single-dose pharmacokinetics of clonazepam following i.m., p.o. and i.v. administration. In an open-label, three-way crossover study, 12 healthy volunteers were randomized to receive a single dose of 2 mg clonazepam either by the i.m., p.o. or i.v. route. Serial blood samples were collected up to 120 h after drug administration. Plasma concentrations of clonazepam were determined by electron-capture gas-liquid chromatography. The absorption rates of clonazepam after i.m. and p.o. administration of clonazepam were significantly different from each other, as reflected by the respective mean values of maximum plasma concentration (C(max) 11.0 vs. 14.9 ng.ml(-1)) and time to reach maximum concentration (t(max) 3.1 vs. 1.7 h). Secondary plasma peaks of clonazepam were observed in 9 volunteers after i.m. injection (C(max) 9.9 ng.ml(-1); t(max) 10.4 h). A comparison of the area under the plasma concentration-time curves (AUC) shows that the i.m. route is equivalent to the oral route (AUC(0- infinity ) 620 vs. 561 ng.h.ml(-1)). Clonazepam was almost completely absorbed after i.m. and p.o. administration, as shown by the mean absolute bioavailability of 93 and 90%, respectively. No significant differences existed between the elimination half-lives (i.v. 38.0 h; i.m. 43.6 h; p.o. 39.0 h). The average clearance and volume of distribution (V(Z)) were 55 ml.min(-1) and 180 liters, respectively. In conclusion, the observed differences in C(max) and t(max) after i.m. and p.o. administration were consistent with a slower absorption rate of clonazepam after i.m. injection. The systemic exposure to clonazepam was not affected by the route of extravascular administration. Statistical evaluation of these kinetic data showed differences in the absorption rate, so that clonazepam given by the i.m. route is not bioequivalent to the oral route. On the basis of the results of this study, we would recommend the same i.m. and p.o. dose in epileptic patients, but therapeutic response would be expected to be less predictable and to occur later in the case of i.m. administration. Copyright 2003 S. Karger AG, Basel

Assessing climate change over the Marche Region (central Italy) from 1961 to 2100: projected changes in mean temperature and future heat waves characterization (with a statistical evaluation of RCMs local performance)

NASA Astrophysics Data System (ADS)

Sangelantoni, Lorenzo; Coluccelli, Alessandro; Russo, Aniello

2014-05-01

Marche region (central Italy, facing the Adriatic Sea) climate dynamics are connected to the Mediterranean basin, identified as one of the most sensitive areas to ongoing climate change. Taken into account difficulties to carry out an overarching assessment over the heterogeneous Mediterranean climate-change issues frame, we opted toward a consistent regional bordered study. Projected changes in mean seasonal temperature, with an introductory multi-statistical model performance evaluation and a future heat waves intensity and duration characterization, are here presented. Multi-model projections over Marche Region, on daily mean, minimum and maximum temperature, have been extracted from the outputs of a set of 7 Regional Climate Models (RCMs) over Europe run by several research Institutes participating to the EU ENSEMBLE project. These climate simulations from 1961 to 2100 refer to the boundary conditions of the IPCC A1B emission scenario, and have a horizontal resolution of 25km × 25km. Furthermore, two RCMs outputs from Med-CORDEX project, with a higher horizontal resolution (12km x 12km) and boundary conditions provided by the new Representative Concentration Pathway (RCP) 4.5 and 8.5, are considered. Observed daily mean, minimum and maximum temperature over Marche region domain have been extracted from E-OBS gridded data set (Version 9.0) referring to the period 1970-2004. This twofold work firstly provides a concise statistical summary of how well employed RCMs reproduce observed (1970-2004) mean temperature over Marche region in term of correlation, root-mean-square difference, and ratio of their variances, graphically displayed on a 2D-Taylor diagram. This multi-statistical model performance evaluation easily allows: - to compare the agreement with observation of the 9 individual RCMs - to compare RCMs with different horizontal resolution (12 km and 25 km) - to evaluate the improvement provided by the RCMs ensemble. Results indicate that the 9 RCMs ensemble provides the statistically best reproduction of the observed interannual mean temperature distribution. Secondly, we assessed projected seasonal ensemble average change in mean temperature referring to the ending 21st century obtained by comparison between 2071-2100 and 1961-1990 time slice modeled mean value over Marche region. Results emphasize summer as the season most affected by projected temperature increase (+4.5°C / +5.0°C), followed by spring season temperature increase (+3.5°C / +4.0°C). Finally, considering that some of the most severe health hazards arise from multi-day heat-waves, associated with both hot day-time and warm night-time temperatures, we assessed modeled trend (1961-2100) of the heat waves intensity and duration: intensity through the temporal evolution of the summer (J J A months) maximum and minimum temperature 90th percentile, heat waves length by temporal evolution of two detected threshold-based indices (annual maximum number of consecutive days characterized by Tmin >= 24°C and annual maximum number of consecutive days characterized by Tmax > = 32°C). Same analysis for both coastal and mountainous areas has been conducted. Future research plans aim to involve ensemble RCMs simulation, processed with bias correction methods, in forcing climate change impacts models, to provide a detailed regional heat waves impacts scenario, mainly over agriculture and health sectors.

Levofloxacin Pharmacokinetics in Adult Cystic Fibrosis

PubMed Central

Lee, Carlton K. K.; Boyle, Michael P.; Diener-West, Marie; Brass-Ernst, Lois; Noschese, Michelle; Zeitlin, Pamela L.

2007-01-01

Background Cystic fibrosis (CF) patients have enhanced renal clearance of aminoglycosides and several β-lactams and require higher dosages. Levofloxacin is a fluoroquinolone with extensive renal elimination and enhanced penetration into lungs and Pseudomonas aeruginosa (PA) biofilms. We studied the preliminary pharmacokinetic and pharmacodynamic (PK/PD) relationship of levofloxacin in CF. Methods Twelve patients at least 18 years old with a mild-to-moderate pulmonary exacerbation and fluoroquinolone-sensitive PA colonization received oral levofloxacin, 500 mg qd, for 14 days. Steady-state serum concentrations were collected after 3 to 7 days, and sputum samples for PA densities were collected before and after levofloxacin. PK/PD relationships for reducing PA sputum densities were evaluated. Results When compared to published data on non-CF patients, CF patients had similar area under the curve for 24 h (AUC24), total clearance, volume of distribution, maximum serum concentration (Cpmax), and elimination half-life: mean, 7.33 μg × h/mL/kg (SD, 1.70); 2.43 mL/min/kg (SD, 0.74); 1.33 L/kg (SD, 0.37); 7.06 μg/mL (SD, 2.35); and 6.44 h (SD, 1.1), respectively. Time to reach maximum serum concentration (Tmax) in CF was longer: mean, 2.20 h (SD, 0.99) vs 1.1 h (SD, 0.4) [p < 0.01]. Preliminary PK/PD analysis failed to demonstrate trends for decreasing PA sputum densities with increasing Cpmax/minimum inhibitory concentration (MIC) ratio and AUC24/MIC ratio. Conclusion CF levofloxacin pharmacokinetics corrected for body weight are similar to non-CF, except for Tmax. Standard levofloxacin dosing (especially monotherapy) is unlikely to produce maximum therapeutic effectiveness. Additional levofloxacin studies in CF are necessary to evaluate its sputum concentrations; the benefits of higher daily dosages (≥ 750 mg); and establish PK/PD targets for managing PA pulmonary infections. PMID:17356095

Estimated plasma bupivacaine concentration after single dose and eight-hour continuous intra-articular infusion of bupivacaine in normal dogs.

PubMed

Bubenik, Loretta; Hosgood, Giselle; Barker, Steven; Hicks, Merrin; Serra, Verna; Stout, Rhett

2007-12-01

To estimate maximum plasma concentration (C(max)) and time to maximum plasma (t(max)) bupivacaine concentration after intra-articular administration of bupivacaine for single injection (SI) and injection followed by continuous infusion (CI) in normal dogs. Cross-over design with a 2-week washout period. Healthy Coon Hound dogs (n=8). Using gas chromatography/mass spectrometry, canine plasma bupivacaine concentration was measured before and after SI (1.5 mg/kg) and CI (1.5 mg/kg and 0.3 mg/kg/h). Software was used to establish plasma concentration-time curves and estimate C(max), T(max) and other pharmacokinetic variables for comparison of SI and CI. Bupivacaine plasma concentration after SI and CI best fit a 3 exponential model. For SI, mean maximum concentration (C(max), 1.33+/-0.954 microg/mL) occurred at 11.37+/-4.546 minutes. For CI, mean C(max) (1.13+/-0.509 microg/mL) occurred at 10.37+/-4.109 minutes. The area under the concentration-time curve was smaller for SI (143.59+/-118.390 microg/mL x min) than for CI (626.502+/-423.653 microg/mL x min, P=.02) and half-life was shorter for SI (61.33+/-77.706 minutes) than for CI (245.363+/-104.415 minutes, P=.01). The highest plasma bupivacaine concentration for any dog was 3.2 microg/mL for SI and 2.3 microg/mL for CI. Intra-articular bupivacaine administration results in delayed absorption from the stifle into the systemic circulation with mean C(max) below that considered toxic and no systemic drug accumulation. Intra-articular bupivacaine can be administered with small risk of reaching toxic plasma concentrations in dogs, though toxic concentrations may be approached. Caution should be exercised with multimodal bupivacaine administration because plasma drug concentration may rise higher than with single intra-articular injection.

Modeling demographic response to constant temperature in Hypera postica (Coleoptera: Curculionidae).

PubMed

Zahiri, Babak; Fathipour, Yaghoub; Khanjani, Mohammad; Moharramipour, Saeid; Zalucki, Myron P

2010-04-01

Alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), is among the most destructive pests of alfalfa, Medicago sativa L., in the world. Survivorship and fecundity schedules of H. postica were investigated to characterize the population growth potential of the weevil at six constant temperatures: 11.5, 14.0, 19.0, 24.0, 29.0, and 31.5 degrees C. Preoviposition period, oviposition period and female longevity significantly decreased with rising temperature within the temperature range tested. At the respective temperatures adult female lived an average of 294.2, 230.2, 163.6, 141.0, 84.10, and 32.9 d, with average lifetime progeny production of 470, 814, 2209, 3619, 2656, and 338 eggs per female. The net reproductive rates (R0) were 86.9, 288.0, 869.7, 1,479.7, 989.8, and 107.8 females per female, respectively. Mean daily fecundity (Mx) was modeled as a function of time by using both Enkegaard and Analytis models. Survivorship data (l(x)) of adult females were summarized and compared using the shape and scale parameters of the Weibull frequency distribution model across the temperature range tested. Life table entropy values within the range 14.0-31.5 degrees C (H < 0.5) indicates Slobodkin's type I survivorship curve; however, the value of 0.806 at 11.5 degrees C (H > 0.5) corresponds to type III. As temperature increased, the r(m) exhibited an asymmetrical dome-shaped pattern, with a maximum value of 0.114 females per female per d at 29.0 degrees C. The r(m)-temperature relation of weevils was modeled and critical temperatures (T(Min), T(Opt), and T(Max)) for intrinsic rate of increase of the weevil were computed as 8.83, 30.61, and 32.14 degrees C and 5.72, 29.94, and 32.12 degrees C by using Analytis/Allahyari and Analytis/Briere-2 models, respectively.

Temperature and relative humidity distributions in a medium-size administrative town in southwest Nigeria.

PubMed

Akinbode, O M; Eludoyin, A O; Fashae, O A

2008-04-01

This study was carried out in one of the medium-sized public administrative towns in the southwestern part of Nigeria. Its aim is to highlight the effect of spatial distribution of settlements, population, and socio-economic activities on urban air temperature and humidity in the town. Temperature and relative humidity data from 1992 to 2001 were obtained from three meteorological stations in Akure, the Administrative Capital of Ondo State, Nigeria. The stations are located within the Federal Ministry of Aviation, Akure Airport (FMA), Federal University of Technology, Akure (FUTA) and Federal School of Agriculture (SOA). Air temperature and relative humidity measurements were also obtained from 27 points, which were cited to include road junctions, markets, built up areas, etc., using sling psychrometer. The data were subsequently analysed for spatial and temporal variations using statistical packages (SPSS and Microsoft Excel) and isolines. Actual vapour pressure and dew point temperature were computed using Magnus conversion formulae. The results obtained showed that spatial variation was insignificant, in terms of the temperature and humidity variables. The annual mean temperature (Tmean) ranged between 21.9 and 30.4 degrees C while minimum (Tmin) and maximum (Tmax) temperatures varied from 13 to 26 and 21.5-39.6 degrees C, respectively. Relative humidity (RH), actual vapour pressure (Es) and dew point temperature (Td) values also varied from 39.1% to 98.2%, 19.7-20.8 gm(-3), and 17.3-17.8 degrees C, respectively. A significant relationship (p>0.6; r<0.05) between Tmin, Es and Td was observed while the daytime 'urban heat island' intensity (UHI) ranged between 0.5 and 2.5 degrees C within the study period. The study concluded that there is influence of urban canopy on the microclimate of Akure, and hypothesizes that the urban dwellers may be subjected to some levels of weather related physiological disorderliness.

Global variation of carbon use efficiency in terrestrial ecosystems

NASA Astrophysics Data System (ADS)

Tang, Xiaolu; Carvalhais, Nuno; Moura, Catarina; Reichstein, Markus

2017-04-01

Carbon use efficiency (CUE), defined as the ratio between net primary production (NPP) and gross primary production (GPP), is an emergent property of vegetation that describes its effectiveness in storing carbon (C) and is of significance for understanding C biosphere-atmosphere exchange dynamics. A constant CUE value of 0.5 has been widely used in terrestrial C-cycle models, such as the Carnegie-Ames-Stanford-Approach model, or the Marine Biological Laboratory/Soil Plant-Atmosphere Canopy Model, for regional or global modeling purposes. However, increasing evidence argues that CUE is not constant, but varies with ecosystem types, site fertility, climate, site management and forest age. Hence, the assumption of a constant CUE of 0.5 can produce great uncertainty in estimating global carbon dynamics between terrestrial ecosystems and the atmosphere. Here, in order to analyze the global variations in CUE and understand how CUE varies with environmental variables, a global database was constructed based on published data for crops, forests, grasslands, wetlands and tundra ecosystems. In addition to CUE data, were also collected: GPP and NPP; site variables (e.g. climate zone, site management and plant function type); climate variables (e.g. temperature and precipitation); additional carbon fluxes (e.g. soil respiration, autotrophic respiration and heterotrophic respiration); and carbon pools (e.g. stem, leaf and root biomass). Different climate metrics were derived to diagnose seasonal temperature (mean annual temperature, MAT, and maximum temperature, Tmax) and water availability proxies (mean annual precipitation, MAP, and Palmer Drought Severity Index), in order to improve the local representation of environmental variables. Additionally were also included vegetation phenology dynamics as observed by different vegetation indices from the MODIS satellite. The mean CUE of all terrestrial ecosystems was 0.45, 10% lower than the previous assumed constant CUE of 0.50. CUE varied significantly between sites - from 0.13 to 0.93 - and between ecosystem types, ranging between 0.41 and 0.60, decreasing from wetlands, to tundra, to croplands, to grasslands until the lower CUE found on average for forested ecosystems. Our analysis shows that ecosystem type was the most important predictor of CUE in terrestrial ecosystems, immediately followed by Tmax; MAT and management practices. For crop, forest and wetland ecosystems CUE varied with climate zones and a strong linear negative correlation was found between CUE and MAT and MAP for grassland ecosystems. Overall, the interaction between different environmental variables showed significant effects on CUE for all ecosystem types. Our results challenge the consideration of a constant value of 0.5 for modeling global purposes, and argue for a deeper understanding of environmental controls on CUE for different ecosystem types.

Pharmacokinetics of sarizotan after oral administration of single and repeat doses in healthy subjects.

PubMed

Krösser, S; Tillner, J; Fluck, M; Ungethüm, W; Wolna, P; Kovar, A

2007-05-01

Sarizotan is a 5-HTIA receptor agonist with high affinity for D3 and D4 receptors. Here we report the pharmacokinetic and tolerability results from four Phase 1 studies. Two single-dose (5 -25 mg, n = 25, 0.5 - 5 mg, n = 16) and two multiple-dose (10 and 20 mg b.i.d., n = 30, 5 mg b.i.d., n = 12) studies with orally administered sarizotan HCl were carried out in healthy subjects. Plasma sarizotan HCl concentrations were measured using a validated HPLC method and fluorescence or MS/MS detection. Pharmacokinetic parameters were obtained using standard non-compartmental methods. Sarizotan was rapidly absorbed, group-median times to reach maximum concentration (tmax) ranged from 0.5 -2.25 h after single doses and during steady state. Maximum plasma concentration (Cmax) and tmax were slightly dependent on formulation and food intake, whereas area under the curve (AUC) was unaffected by these factors. AUC and Cmax increased dose-proportionally over the tested dose range. Independently of dose and time, sarizotan HCl plasma concentrations declined polyexponentially with a terminal elimination half-life (t1/2) of 5 - 7 h. Accumulation factors corresponded to t1/2 values, and steady state was reached within 24 h. Plasma metabolite concentrations were considerably lower than those of the parent drug. The ratio metabolite AUC : parent drug AUC was time- and dose-independent for all three metabolites suggesting that the metabolism of sarizotan is non-saturable in the tested dose range. The pharmacokinetics of sarizotan were dose-proportional and time-independent for the dose range 0.5 -25 mg). The drug was well-tolerated by healthy subjects up to a single dose of 20 mg.

Pharmacokinetics of dexamethasone following intra-articular, intravenous, intramuscular, and oral administration in horses and its effects on endogenous hydrocortisone.

PubMed

Soma, L R; Uboh, C E; Liu, Y; Li, X; Robinson, M A; Boston, R C; Colahan, P T

2013-04-01

This study investigated and compared the pharmacokinetics of intra-articular (IA) administration of dexamethasone sodium phosphate (DSP) into three equine joints, femoropatellar (IAS), radiocarpal (IAC), and metacarpophalangeal (IAF), and the intramuscular (IM), oral (PO) and intravenous (IV) administrations. No significant differences in the pharmacokinetic estimates between the three joints were observed with the exception of maximum concentration (Cmax ) and time to maximum concentration (Tmax ). Median (range) Cmax for the IAC, IAF, and IAS were 16.9 (14.6-35.4), 23.4 (13.5-73.0), and 46.9 (24.0-72.1) ng/mL, respectively. The Tmax for IAC, IAF, and IAS were 1.0 (0.75-4.0), 0.62 (0.5-1.0), and 0.25 (0.08-0.25) h, respectively. Median (range) elimination half-lives for IA and IM administrations were 3.6 (3.0-4.6) h and 3.4 (2.9-3.7) h, respectively. A 3-compartment model was fitted to the plasma dexamethasone concentration-time curve following the IV administration of DSP; alpha, beta, and gamma half-lives were 0.03 (0.01-0.05), 1.8 (0.34-2.3), and 5.1 (3.3-5.6) h, respectively. Following the PO administration, the median absorption and elimination half-lives were 0.34 (0.29-1.6) and 3.4 (3.1-4.7) h, respectively. Endogenous hydrocortisone plasma concentrations declined from a baseline of 103.8 ± 29.1-3.1 ± 1.3 ng/mL at 20.0 ± 2.7 h following the administration of DSP and recovered to baseline values between 96 and 120 h for IV, IA, and IM administrations and at 72 h for the PO. © 2012 Blackwell Publishing Ltd.

A thorough QT study to evaluate the QTc prolongation potential of two neuropsychiatric drugs, quetiapine and escitalopram, in healthy volunteers.

PubMed

Kim, Anhye; Lim, Kyoung Soo; Lee, Howard; Chung, Hyewon; Yoon, Seo Hyun; Yu, Kyung-Sang; Cho, Joo-Youn; Jang, In-Jin; Chung, Jae-Yong

2016-07-01

Prolongation of the QT interval on an ECG is a surrogate marker for predicting the proarrhythmic potential of a drug under development. The aim of this study was to evaluate the QTc prolongation potential of two neuropsychiatric drugs, quetiapine immediate release (IR) and escitalopram, in healthy individuals. This was a randomized, open-label, 4×4 Williams crossover study, with four single-dose treatments [placebo, 400 mg moxifloxacin (positive control), 20 mg escitalopram, and 100 mg quetiapine IR], conducted in 40 healthy volunteers. Serial blood samples for pharmacokinetics and ECG were collected. Individually, RR-corrected QTc intervals (QTcI) and placebo-adjusted changes from baseline values of QTcI (ΔΔQTcI) were evaluated. Lower-bound values of the one-sided 95% confidence interval for ΔΔQTcI of moxifloxacin with more than 5 ms confirmed the sensitivity of the assay. The maximum upper bound 95% confidence interval for the ΔΔQTcI of quetiapine IR and escitalopram was 13.7 and 10.5 ms, with mean estimates of 10.2 and 6.9 ms, respectively. Peak effects of moxifloxacin and quetiapine IR on ΔΔQTcI were observed at approximately time to maximum concentration (Tmax), whereas that of escitalopram was observed 3 h after Tmax. The concentration-ΔΔQTcI relationships of quetiapine IR and escitalopram were relatively flat, as compared with that of moxifloxacin. The results demonstrated the validity of trial methodology and that quetiapine IR and escitalopram caused QT prolongation in healthy individuals. In addition, hysteresis of escitalopram-induced QTc prolongation. These results indicate that higher doses of these drugs could lead to greater QT prolongation in a dose-response manner.

A randomized crossover study to assess the pharmacokinetics of a novel amphetamine extended-release orally disintegrating tablet in healthy adults.

PubMed

Stark, Jeffrey G; Engelking, Dorothy; McMahen, Russ; Sikes, Carolyn

2016-09-01

In this pharmacokinetic (PK) study in healthy adults, we sought to: (1) compare the PK properties of a novel amphetamine extended-release orally disintegrating tablet formulation (Adzenys XR-ODT™ [AMP XR-ODT]) to a reference extended-release mixed amphetamine salts (MAS ER) formulation and (2) assess the effect of food on AMP XR-ODT. Forty-two adults were enrolled in a single-dose, open-label, 3-period, 3-treatment, randomized crossover study and received an 18.8-mg dose of AMP XR-ODT (fasted or fed) or equivalent dose (30 mg) of MAS ER (fasted). Plasma samples were analyzed for d-and l-amphetamine. Maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax), elimination half-life (T1/2), area under the concentration-time curve from time zero to last quantifiable concentration (AUClast), from time zero to infinity (AUCinf), relevant partial AUCs, and weight-normalized clearance (CL/F/kg) were assessed. The PK parameters were compared across treatments using an ANOVA. Safety was also assessed. A total of 39 adults completed this study. The geometric mean ratios (90% confidence interval [CI]) for AMP XR-ODT/MAS ER Cmax, AUC5-last, AUClast, and AUCinf were within 80%-125% for both d-and l-amphetamine. The 90% CIs for AUC0-5 were slightly below the 80%-125% range. When AMP XR-ODT was administered with food, there was a slight decrease in the d-and l-amphetamine Cmax and approximately a 2-hour delay in Tmax. The most common adverse events reported (>5% of participants) were dry mouth, palpitations, nausea, dizziness, headache, anxiety, and nasal congestion. AMP XR-ODT displayed a PK profile similar to MAS ER, and no clinically relevant food effect was observed.

Nicotine delivery, retention, and pharmacokinetics from various electronic cigarettes

PubMed Central

St. Helen, Gideon; Havel, Christopher; Dempsey, Delia; Jacob, Peyton; Benowitz, Neal L.

2015-01-01

Aims To measure the systemic retention of nicotine, propylene glycol (PG), and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. Design E-cigarette users recruited over the Internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several time after use. Setting San Francisco, California, USA. Participants Thirteen healthy, experienced adult e-cigarette users (6 females and 7 males). Measurements Plasma nicotine was analyzed by GC-MS/MS, and nicotine, VG, and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. Findings E-cigarettes delivered an average of 1.3 (0.9–1.8) mg (mean and 95% CI) of nicotine and 94% of the inhaled dose, 1.2 (0.8–1.7), was systemically retained. Average maximum plasma nicotine concentration (Cmax) was 8.4 (5.4–11.5) ng/mL and time of maximal concentration (Tmax) was 2 to 5 minutes; one participant had Tmax of 30 minutes. 89% and 92% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 bpm after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. Conclusions E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarettes users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. PMID:26430813

Therapeutically equivalent pharmacokinetic profile across three application sites for AG200-15, a novel low-estrogen dose contraceptive patch.

PubMed

Stanczyk, Frank Z; Archer, David F; Rubin, Arkady; Foegh, Marie

2013-06-01

AG200-15 Agile Patch (AP) is a novel 7-day contraceptive patch providing ethinyl estradiol (EE) exposure comparable to low-dose combination oral contraceptives. This study determined whether application of the AP to three different anatomical sites (lower abdomen, buttock and upper torso) influences the pharmacokinetic profile of EE and levonorgestrel (LNG). In this open-label, three-period, crossover study, 24 subjects were randomized to one of six treatment sequences; each included application of patch to abdomen, buttock and upper torso, with the AP worn on one site for 7 days. After a 7-day washout, a new patch was applied to the next anatomical site. Multiple blood samples were collected up to 240 h after patch application. For plasma EE levels, median time to maximum drug concentration (Tmax, 24-48 h) and mean maximum concentration (Cmax, 47.9-61.5 pg/mL) were similar among application sites. Compared with lower abdomen, EE exposure was higher (16%-30%) at buttock and upper torso (15%-22%). For plasma LNG levels, median Tmax (72-120 h) and mean Cmax (1436-1589 pg/mL) were similar across application sites. Compared with lower abdomen, LNG exposure was higher at buttock (1%-7%) and upper torso (16%-17%). No serious adverse events (AEs) or AE-related discontinuations occurred. The most common treatment-emergent AEs were nausea, application site pruritus and headache, with frequencies comparable across anatomical sites. Absorption from the abdomen was slightly lower versus other sites; however, exposure to EE and LNG for all sites was therapeutically equivalent. The AP was well tolerated at all three anatomical sites. Copyright © 2013 Elsevier Inc. All rights reserved.

Ultrasound assessment of diaphragmatic function in patients with amyotrophic lateral sclerosis.

PubMed

Fantini, Riccardo; Mandrioli, Jessica; Zona, Stefano; Antenora, Federico; Iattoni, Andrea; Monelli, Marco; Fini, Nicola; Tonelli, Roberto; Clini, Enrico; Marchioni, Alessandro

2016-07-01

Evaluation of diaphragm function in Amyotrophic Lateral Sclerosis (ALS) is critical in determining when to commence non-invasive mechanical ventilation (NIV). Currently, forced vital capacity (FVC) and sniff nasal inspiratory pressure (SNIP) are volitional measures for this evaluation, but require collaboration and are poorly specific. The primary aim of this study was to assess whether diaphragmatic thickness measured by ultrasound (US) correlates with lung function impairment in ALS patients. The secondary aim was then to compare US diaphragm thickness index (ΔTdi) with a new parameter (ΔTmax index). 41 patients with ALS and 30 healthy subjects were enrolled in the study. All subjects underwent spirometry, SNIP and diaphragm US evaluation, while arterial blood gases were measured in some patients only. US assessed diaphragm thickness (Tdi) at tidal volume (Vt) or total lung capacity (TLC), and their ratio (ΔTmax) were recorded. Changes (Δ) in Tdi indices during tidal volume (ΔTdiVt) and maximal inspiration (ΔTdiTLC) were also assessed. ΔTdiTLC (p <0.001) and ΔTmax (p = 0.007), but not ΔTdiVt, differed between patients and controls. Significant correlation (p < 0.05) was found between ΔTdiTLC, ΔTmax and FVC. The ROC curve analysis for comparison of individual testing showed better accuracy with Δtmax than with ΔtdiTLC for FVC (AUC 0.76 and 0.27) and SNIP (AUC 0.71 and 0.25). Diaphragm thickness assessed by ultrasound significantly correlates with global respiratory alterations in patients with ALS. ΔTmax represents a new US index of early diaphragmatic dysfunction, better related with the routinely performed lung function tests. © 2016 Asian Pacific Society of Respirology.

Modelling uncertainties and possible future trends of precipitation and temperature for 10 sub-basins in Columbia River Basin (CRB)

NASA Astrophysics Data System (ADS)

Ahmadalipour, A.; Rana, A.; Qin, Y.; Moradkhani, H.

2014-12-01

Trends and changes in future climatic parameters, such as, precipitation and temperature have been a central part of climate change studies. In the present work, we have analyzed the seasonal and yearly trends and uncertainties of prediction in all the 10 sub-basins of Columbia River Basin (CRB) for future time period of 2010-2099. The work is carried out using 2 different sets of statistically downscaled Global Climate Model (GCMs) projection datasets i.e. Bias correction and statistical downscaling (BCSD) generated at Portland State University and The Multivariate Adaptive Constructed Analogs (MACA) generated at University of Idaho. The analysis is done for with 10 GCM downscaled products each from CMIP5 daily dataset totaling to 40 different downscaled products for robust analysis. Summer, winter and yearly trend analysis is performed for all the 10 sub-basins using linear regression (significance tested by student t test) and Mann Kendall test (0.05 percent significance level), for precipitation (P), temperature maximum (Tmax) and temperature minimum (Tmin). Thereafter, all the parameters are modelled for uncertainty, across all models, in all the 10 sub-basins and across the CRB for future scenario periods. Results have indicated in varied degree of trends for all the sub-basins, mostly pointing towards a significant increase in all three climatic parameters, for all the seasons and yearly considerations. Uncertainty analysis have reveled very high change in all the parameters across models and sub-basins under consideration. Basin wide uncertainty analysis is performed to corroborate results from smaller, sub-basin scale. Similar trends and uncertainties are reported on the larger scale as well. Interestingly, both trends and uncertainties are higher during winter period than during summer, contributing to large part of the yearly change.

Emergence of the significant local warming of Korea in CMIP5 projections

NASA Astrophysics Data System (ADS)

Boo, Kyung-On; Shim, Sungbo; Kim, Jee-Eun

2016-04-01

According to IPCC AR5, anthropogenic influence on warming is obvious in local scales, especially in some tropical regions. Detection of significant local warming is important for adaptation to climate change of society and ecosystem. Recently much attention has focused on the time of emergence (ToE) for the signal of anthropogenic climate change against the natural climate variability. Motivated from the previous studies, this study analyzes ToE of regional surface air temperature over Korea. Simulations of CMIP5 15 models are used for RCP 2.6, 4.5 and 8.5. For each year, JJA and DJF temperature anomalies are calculated for the time period 1900-1929. For noise of interannual variability, natural-only historical simulations of CMIP5 12 models are used and the standard deviation of the time series is obtained. For signal of warming, we examine the year when the signal above 2 standard deviations is detected in 80% of the models using 30-year smoothed time series. According to our results, interannual variability is larger in land than ocean. Seasonally, it is larger in winter than in summer. Accordingly, ToE of summertime temperature is earlier than that in winter and is expected to appear in 2030s from three RCPs. The seasonal difference is consistent with previous studies. Wintertime ToE appears in 2040s for RCP85 and 2060s for RCP4.5. The different emergence time between RCP8.5 and RCP4.5 reflects the influence of mitigation. In a similar way, daily maximum and minimum temperatures are analyzed. ToE of Tmin appears earlier than that of Tmax and difference is small. Acknowledgements. This study is supported by the National Institute of Meteorological Sciences, Korea Meteorological Administration (NIMR-2012-B-2).

A Comparative Pharmacokinetics Study of the Anti-Parkinsonian Drug Pramipexole

PubMed Central

Putri, Ratih S. I.; Setiawati, Effi; Aziswan, Syifa A.; Ong, Fenny; Tjandrawinata, Raymond R.; Susanto, Liana W.

2016-01-01

The present study aimed to compare pharmacokinetic parameters of two pramipexole 0.25 mg formulations in order to show bioequivalence. The study was conducted in a randomized, open-label, two-period, two-sequence, and crossover design, involving 23 healthy volunteers. One of the 0.25 mg formulations of pramipexole evaluated in the study was manufactured by PT Dexa Medica, Palembang, Indonesia, the other, used as the reference, by Boehringer Ingelheim Pharma GmbH & Co. KG, Ingelheim am Rhein, Germany. All eligible subjects were required to fast before each drug administration period, which was separated by a one-week washout period. Pramipexole concentrations in plasma were assayed using a validated ultra performance liquid chromatography with mass spectrometry (UPLC-MS/MS) detector. The evaluated pharmacokinetic parameters included the area under the plasma concentration curve from time zero to the last observed measurable concentration (AUC0-t), the area under the plasma concentration curve extrapolated to infinite time (AUC0-∞), the maximum plasma concentration (Cmax), the time to reach Cmax (tmax), and the plasma concentration half-life (t1/2). To evaluate the bioequivalence of those two pramipexole formulations, 90% confidence intervals (CIs) for geometric mean ratios of both formulations were calculated for AUC and Cmax parameters, while tmax and t1/2 differences were analyzed on the non-transformed data using Wilcoxon matched-pairs and a Student’s paired t-test, respectively. The 90% CIs for the geometric mean ratios of the two pramipexole formulations were 95.89% (90.73%–101.34%), 95.53% (89.75%–101.68%), and 92.11% (84.35%–100.58%) for AUC0-t, AUC0-∞, and Cmax, respectively. There were no statistically significant differences for tmax and t1/2 between the two pramipexole formulations. It is concluded that two pramipexole formulations in this study were bioequivalent. PMID:27869754

A comparative climate analysis of heat-related emergency 911 dispatches: Chicago, Illinois and Phoenix, Arizona USA 2003 to 2006.

PubMed

Hartz, Donna A; Brazel, Anthony J; Golden, Jay S

2013-09-01

Research into the health impacts of heat has proliferated since 2000. Temperature increases could exacerbate the increased heat already experienced by urban populations due to urbanization. Heat-related mortality studies have found that hot southern cities in North America have not experienced the summer increases in mortality found in their more northern counterparts. Heat-related morbidity studies have not assessed this possible regional difference. This comparison study uses data from emergency 911 dispatches [referred to as heat-related dispatches (HRD)] identified by responders as heat-related for two United States cities located in different regions with very different climates: Chicago, Illinois in the upper midwest and Phoenix, Arizona in the southwest. Phoenix's climate is hot and arid. Chicago's climate is more temperate, but can also experience days with unusually high temperatures combined with high humidity. This study examines the relationships between rising HRD and daily temperatures: maximum (Tmax); apparent (ATmax): minimum (Tmin) and two energy balance indices (PET and UTCI). Phoenix had more HRD cumulatively, over a longer warm weather season, but did not experience the large spikes in HRD that occurred in Chicago, even though it was routinely subjected to much hotter weather conditions. Statistical analyses showed the strongest relationships to daily ATmax for both cities. Phoenix's lack of HRD spikes, similar to the summer mortality patterns for southern cities, suggests an avenue for future research to better understand the dynamics of possible physiological or behavioral adaption that seems to reduce residents' vulnerability to heat.

A comparative climate analysis of heat-related emergency 911 dispatches: Chicago, Illinois and Phoenix, Arizona USA 2003 to 2006

NASA Astrophysics Data System (ADS)

Hartz, Donna A.; Brazel, Anthony J.; Golden, Jay S.

2013-09-01

Research into the health impacts of heat has proliferated since 2000. Temperature increases could exacerbate the increased heat already experienced by urban populations due to urbanization. Heat-related mortality studies have found that hot southern cities in North America have not experienced the summer increases in mortality found in their more northern counterparts. Heat-related morbidity studies have not assessed this possible regional difference. This comparison study uses data from emergency 911 dispatches [referred to as heat-related dispatches (HRD)] identified by responders as heat-related for two United States cities located in different regions with very different climates: Chicago, Illinois in the upper midwest and Phoenix, Arizona in the southwest. Phoenix's climate is hot and arid. Chicago's climate is more temperate, but can also experience days with unusually high temperatures combined with high humidity. This study examines the relationships between rising HRD and daily temperatures: maximum (Tmax); apparent (ATmax): minimum (Tmin) and two energy balance indices (PET and UTCI). Phoenix had more HRD cumulatively, over a longer warm weather season, but did not experience the large spikes in HRD that occurred in Chicago, even though it was routinely subjected to much hotter weather conditions. Statistical analyses showed the strongest relationships to daily ATmax for both cities. Phoenix's lack of HRD spikes, similar to the summer mortality patterns for southern cities, suggests an avenue for future research to better understand the dynamics of possible physiological or behavioral adaption that seems to reduce residents' vulnerability to heat.

Fatigue-environment interactions in a SiC/Ti-15-3 composite

NASA Technical Reports Server (NTRS)

Gayda, J.; Gabb, T. P.; Lerch, B. A.

1993-01-01

Load-controlled isothermal and nonisothermal fatigue lives of a (0-deg)s SiC/Ti-15-3 were evaluated at temperatures between 150 and 550 C and a target strain range of about 0.45 percent. In nonisothermal fatigue tests, load was first cycled at minimum temperature and then temperature was cycled at zero load. For fatigue tests with peak temperatures at or above 300 C, fatigue life was dramatically reduced compared to that at 150 C. The shortest life was produced by the nonisothermal test with the greatest temperature range (Delta T = 400 C) and highest peak temperature (T(max) = 550 C). Vacuum testing showed that much of the life reduction under isothermal and nonisothermal conditions was related to environmental effects, although the nature of the fatigue-environment interaction was decidedly different for the isothermal and nonisothermal test cycles which were studied.

Climate effect on forest fire static risk assessment

NASA Astrophysics Data System (ADS)

Bodini, Antonella; Cossu, Antonello; Entrade, Erika; Fiorucci, Paolo; Gaetani, Francesco; Parodi, Ulderica

2010-05-01

The availability of a long data series of fire perimeters combined with a detailed knowledge of topography and land cover allow to understand which are the main features involved in forest fire occurrences and their behaviour. In addition, climate indexes obtained from the analysis of time series with more than 20 years of complete records allow to understand the role of climate on fire regime, both in terms of direct effects on fire behaviour and the effect on vegetation cover. In particular, indices of extreme events have been considered like CDD (maximum number of consecutive dry days) and HWDI (heat wave duration index: maximum period > 5 consecutive days with Tmax >5°C above the 1961-1990 daily Tmax normal), together with the usual indices describing rainfall and temperature regimes. As a matter of fact, based on this information it is possible to develop statistical methods for the objective classification of forest fire static risk at regional scale. Two different case studies are presented in this work: Regione Liguria and Regione Sardegna (Italy). Both regions are in the center of the Mediterranean and are characterized by a high number of fires and burned area. However, the two regions have very different fire regimes. Sardinia is affected by the fire phenomenon only in summer whilst Liguria is affected by fires also in winter, with higher number of fires and larger burned area. In addition, the two region are very different in vegetation cover. The presence of Mediterranean conifers, (Pinus Pinaster, Pinus Nigra, Pinus halepensis) is quite spread in Liguria and is almost absent in Sardinia. What is common in the two regions is the widespread presence of shrub species frequently spread by fire. The analysis in the two regions thus allows in a rather limited area to consider almost all the species and the climate conditions that characterize the Mediterranean region. More than 10000 fire perimeters that burnt about 800 km2 were considered in the analysis. The analysis has been carried out at 20 m spatial resolution. Some important considerations relating to climate and the territorial features that characterize the fire regime in the considered regions contribute to better understand the forest fire phenomena. These results allow to define new strategies for forest fire prevention and management extendable to other geographical areas. This research is part of the project PROTERINA C, funded by the EU under the Italy-France Maritime Programme, aiming at investigating the effects that climate change could have on the environment (fuels).

End-growth/evaporation living polymerization kinetics revisited

NASA Astrophysics Data System (ADS)

Semenov, A. N.; Nyrkova, I. A.

2011-03-01

End-growth/evaporation kinetics in living polymer systems with "association-ready" free unimers (no initiator) is considered theoretically. The study is focused on the systems with long chains (typical aggregation number N ≫ 1) at long times. A closed system of continuous equations is derived and is applied to study the kinetics of the chain length distribution (CLD) following a jump of a parameter (T-jump) inducing a change of the equilibrium mean chain length from N0 to N. The continuous approach is asymptotically exact for t ≫ t1, where t1 is the dimer dissociation time. It yields a number of essentially new analytical results concerning the CLD kinetics in some representative regimes. In particular, we obtained the asymptotically exact CLD response (for N ≫ 1) to a weak T-jump (ɛ = N0/N - 1 ≪ 1). For arbitrary T-jumps we found that the longest relaxation time tmax = 1/γ is always quadratic in N (γ is the relaxation rate of the slowest normal mode). More precisely tmax ∝4N2 for N0 < 2N and tmax ∝NN0/(1 - N/N0) for N0 > 2N. The mean chain length Nn is shown to change significantly during the intermediate slow relaxation stage t1 ≪ t ≪ tmax . We predict that N_n(t)-N_n(0)∝ √{t} in the intermediate regime for weak (or moderate) T-jumps. For a deep T-quench inducing strong increase of the equilibrium Nn (N ≫ N0 ≫ 1), the mean chain length follows a similar law, N_n(t)∝ √{t}, while an opposite T-jump (inducing chain shortening, N0 ≫ N ≫ 1) leads to a power-law decrease of Nn: Nn(t)∝t-1/3. It is also shown that a living polymer system gets strongly polydisperse in the latter regime, the maximum polydispersity index r = Nw/Nn being r* ≈ 0.77N0/N ≫ 1. The concentration of free unimers relaxes mainly during the fast process with the characteristic time tf ˜ t1N0/N2. A nonexponential CLD dominated by short chains develops as a result of the fast stage in the case of N0 = 1 and N ≫ 1. The obtained analytical results are supported, in part, by comparison with numerical results found both previously and in the present paper.

Protective/restorative Role of the Adipose Tissue-derived Mesenchymal Stem Cells on the Radioiodine-induced Salivary Gland Damage in Rats

PubMed Central

Saylam, Güleser; Bayır, Ömer; Pınarlı, Ferda Alparslan; Han, Ünsal; Korkmaz, Mehmet Hakan; Sancaktar, Mehmet Eser; Tatar, İlkan; Sargon, Mustafa Fevzi; Tatar, Emel Çadallı

2017-01-01

Abstract Background To analyze protective/regenerative effects of adipose tissue-derived mesenchymal stem cells (ADMSC) on 131I-Radioiodine (RAI)-induced salivary gland damage in rats. Materials and Methods Study population consisted of controls (n:6) and study groups (n:54): RAI (Group 1), ADMSC (Group 2), amifostine (Group 3), RAI+amifostine (Group 4), concomitant RAI+ADMSC (Group 5) and RAI+ADMSC after 48 h (Group 6). We used light microscopy (LM), transmission electron microscopy (TEM), and salivary gland scintigraphy (SGS), and analyzed data statistically. Results We observed the homing of ADMSC in salivary glands at 1st month on LM. RAI exposure affected necrosis, periductal fibrosis, periductal sclerosis, vascular sclerosis and the total sum score were in a statistically significant manner (P < 0.05). Intragroup comparisons with LM at 1st and 6th months revealed statistically significant improvements in Group 6 (P < 0.05) but not in Groups 4 and 5. Intergroup comparisons of the total score showed that Groups 4 and 5 in 1st month and Group 6 in 6th month had the lowest values. TEM showed vacuolization, edema, and fibrosis at 1st month, and an improvement in damage in 6th month in Groups 5 and 6. SGSs revealed significant differences for the maximum secretion ratio (Smax) (P = 0.01) and the gland-to-background ratio at a maximum count (G/BGmax) (P = 0. 01) at 1st month, for G/BGmax (P = 0.01), Smax (P = 0.01) and the time to reach the maximum count ratio over the time to reach the minimum count (Tmax/Tmin) (P = 0.03) at 6th month. 1st and 6th month scans showed differences for Smax and G/BGmax (P = 0.04), but not for Tmax/Tmin (p > 0.05). We observed a significant deterioration in gland function in group 1, whereas, mild to moderate deteriorations were seen in protective treatment groups. Conclusions Our results indicated that ADMSC might play a promising role as a protective/regenerative agent against RAI-induced salivary gland dysfunction. PMID:28959167

A digital sedimentator for measuring erythrocyte sedimentation rate using a linear image sensor

NASA Astrophysics Data System (ADS)

Yoshikoshi, Akio; Sakanishi, Akio; Toyama, Yoshiharu

2004-11-01

A digital apparatus was fabricated to determine accurately the erythrocyte sedimentation rate (ESR) using a linear image sensor. Currently, ESR is utilized for clinical diagnosis, and in the laboratory as one of the many rheological properties of blood through the settling of red blood cells (RBCs). In this work, we aimed to measure ESR automatically using a small amount of a sample and without moving parts. The linear image sensor was placed behind a microhematocrit tube containing 36 μl of RBC suspension on a holder plate; the holder plate was fixed on an optical bench together with a tungsten lamp and an opal glass placed in front. RBC suspensions were prepared in autologous plasma with hematocrit H from 25% to 44%. The intensity profiles of transmitted light in 36 μl of RBC suspension were detected using the linear image sensor and sent to a personal computer every minute. ESR was observed at the settling interface between the plasma and RBC suspension in the profile in 1024 pixels (25 μm/pixel) along a microhematocrit tube of 25.6 mm total length for 1 h at a temperature of 37.0±0.1 °C. First, we determined the initial pixel position of the sample at the boundary with air. The boundary and the interface were defined by inflection points in the profile with 25 μm resolution. We obtained sedimentation curves that were determined by the RBC settling distance l(t) at the time t from the difference between pixel locations at the boundary and the interface. The sedimentation curves were well fitted to an empirical equation [Puccini et al., Biorheol. 14, 43 (1977)] from which we calculated the maximum sedimentation velocity smax at the time tmax. We reached tmax within 30 min at any H, and smax linearly related to the settling distance l(60) at 60 min after the start of sedimentation from 30% to 44% H with the correlation coefficient r=0.993. Thus, we may estimate conventional ESR at 1 h from smax more quickly and accurately with less effort.

Evaluation and monitoring of UVR in Shield Metal ARC Welding processing.

PubMed

Peng, Chiung-yu; Liu, Hung-hsin; Chang, Cheng-ping; Shieh, Jeng-yueh; Lan, Cheng-hang

2007-08-01

This study established a comprehensive approach to monitoring UVR magnitude from Shield Metal Arc Welding (SMAW) processing and quantified the effective exposure based on measured data. The irradiances from welding UVR were calculated with biological effective parameter (Slambda) for human exposure assessment. The spectral weighting function for UVR measurement and evaluation followed the American Conference of Governmental Industrial Hygienists (ACGIH) guidelines. Arc welding processing scatters bright light with UVR emission over the full UV spectrum (UVA, UVB, and UVC). The worst case of effective irradiance from a 50 cm distance arc spot with a 200 A electric current and an electrode E6011 (4 mm) is 311.0 microW cm(-2) and has the maximum allowance time (Tmax) of 9.6 s. Distance is an important factor affecting the irradiance intensity. The worst case of the effective irradiance values from arc welding at 100, 200, and 300 cm distances are 76.2, 16.6, and 12.1 microW cm(-2) with Tmax of 39.4, 180.7, and 247.9 s, respectively. Protective materials (glove and mask) were demonstrated to protect workers from hazardous UVR exposure. From this study, the methodology of UVR monitoring in SMAW processing was developed and established. It is recommended that welders should be fitted with appropriate protective materials for protection from UVR emission hazards.

Progesterone administration by nasal spray in menopausal women: comparison between two different spray formulations.

PubMed

Cicinelli, E; Savino, F; Cagnazzo, I; Scorcia, P; Galantino, P

1992-12-01

The aim of the study was to compare the bioavailability of progesterone dissolved in almond oil or dimethicone, and administered by nasal spray. Twenty healthy menopausal women were randomly allocated to treatment by four doses of intranasal spray either of a progesterone solution in almond oil, 2 mg/0.1 ml, corresponding to a total dose of approximately 11 mg of progesterone, or a progesterone solution in dimethicone 5 mg/0.1 ml corresponding to a total dose of approximately 28 mg of progesterone. Circulating progesterone levels were calculated at various time intervals following administration. The formulation with almond oil yielded a maximum progesterone concentration (Cmax of 3.75 ng/ml at Tmax = 60 min, and the area under the curve (AUC0-720) value was 1481.6 +/- 343. The formulation with dimethicone yielded a mean Cmax of 1.049 ng/ml at Tmax = 30 min; the AUC0-720 value was 302.06 +/- 37.5. Therefore, bioavailability of progesterone dissolved in almond oil proved to be largely superior compared to the solution in dimethicone. The crucial role of the carrier in the spray formulations is discussed; in addition to ensuring clinical safety, it must have good solubility for progesterone, be fluid enough to enable efficient 'spraying' and also must allow progesterone to be absorbed through the nasal mucosa.

Enhancement of the Oral Bioavailability of Fexofenadine Hydrochloride via Cremophor® El-Based Liquisolid Tablets

PubMed Central

Yehia, Soad Ali; El-Ridi, Mohamed Shafik; Tadros, Mina Ibrahim; El-Sherif, Nolwa Gamal

2015-01-01

Purpose: The current work aimed to develop promising Fexofenadine hydrochloride (FXD) liquisolid tablets able to increase its oral bioavailability and shorten time to reach maximum plasma concentrations (Tmax). Methods: Eighteen liquisolid powders were developed based on 3 variables; (i) vehicle type [Propylene glycol (PG) or Cremophor® EL (CR)], (ii) carrier [Avicel® PH102] to coat [Aerosil® 200] ratio (15, 20, 25) and (iii) FXD concentration in vehicle (30, 35, 40 %, w/w). Pre-compression studies involved identification of physicochemical interactions and FXD crystallinity (FT-IR, DSC, XRD), topographic visualization (SEM) and estimation of flow properties (angle of repose, Carr’s index, Hausner’s ratio). CR-based liquisolid powders were compressed as liquisolid tablets (LST 9 – 18) and evaluated for weight-variation, drug-content, friability-percentage, disintegration-time and drug-release. The pharmacokinetics of LST-18 was evaluated in healthy volunteers relative to Allegra® tablets. Results: Pre-compression studies confirmed FXD dispersion in vehicles, conversion to amorphous form and formation of liquisolid powders. CR-based liquisolid powders showed acceptable-to-good flow properties suitable for compaction. CR-based LSTs had appropriate physicochemical properties and short disintegration times. Release profile of LST-18 showed a complete drug release within 5 min. Conclusion: LST-18 succeeded in increasing oral FXD bioavailability by 62% and reducing Tmax to 2.16 h. PMID:26819931

Pantechnik new superconducting ion source: PantechniK Indian Superconducting Ion Source.

PubMed

Gaubert, G; Bieth, C; Bougy, W; Brionne, N; Donzel, X; Leroy, R; Sineau, A; Vallerand, C; Villari, A C C; Thuillier, T

2012-02-01

The new ECR ion source PantechniK Indian Superconducting Ion Source (PKISIS) was recently commissioned at Pantechnik. Three superconducting coils generate the axial magnetic field configuration, while the radial magnetic field is done with the multi-layer permanent magnets. Special care was devoted to the design of the hexapolar structure, allowing a maximum magnetic field of 1.32 T at the wall of the 82 mm diameter plasma chamber. The three superconducting coils using low temperature superconducting wires are cooled by a single double stage cryo-cooler (4.2 K). Cryogen-free technology is used, providing reliability and easy maintenance at low cost. The maximum installed RF power (18.0 GHz) is of 2 kW. Metallic beams can be produced with an oven (T(max) = 1400 °C) installed with an angle of 5° with respect to the source axis or a sputtering system, mounted on the axis of the source. The beam extraction system is constituted of three electrodes in accel-decel configuration. The new source of Pantechnik is conceived for reaching optimum performances at 18 GHz RF frequencies. PKISIS magnetic fields are 2.1 T axial B(inj) and 1.32 T radial field in the wall, variable B(min) with an independent coil and a large and opened extraction region. Moreover, PKISIS integrates modern design concepts, like RF direct injection (2 kW availability), dc-bias moving disk, out-of-axis oven and axial sputtering facility for metal beams. Finally, PKISIS is also conceived in order to operate in a high-voltage platform with minor power consumption.

An alternative method to estimate zero flow temperature differences for Granier's thermal dissipation technique.

PubMed

Regalado, Carlos M; Ritter, Axel

2007-08-01

Calibration of the Granier thermal dissipation technique for measuring stem sap flow in trees requires determination of the temperature difference (DeltaT) between a heated and an unheated probe when sap flow is zero (DeltaT(max)). Classically, DeltaT(max) has been estimated from the maximum predawn DeltaT, assuming that sap flow is negligible at nighttime. However, because sap flow may continue during the night, the maximum predawn DeltaT value may underestimate the true DeltaT(max). No alternative method has yet been proposed to estimate DeltaT(max) when sap flow is non-zero at night. A sensitivity analysis is presented showing that errors in DeltaT(max) may amplify through sap flux density computations in Granier's approach, such that small amounts of undetected nighttime sap flow may lead to large diurnal sap flux density errors, hence the need for a correct estimate of DeltaT(max). By rearranging Granier's original formula, an optimization method to compute DeltaT(max) from simultaneous measurements of diurnal DeltaT and micrometeorological variables, without assuming that sap flow is negligible at night, is presented. Some illustrative examples are shown for sap flow measurements carried out on individuals of Erica arborea L., which has needle-like leaves, and Myrica faya Ait., a broadleaf species. We show that, although DeltaT(max) values obtained by the proposed method may be similar in some instances to the DeltaT(max) predicted at night, in general the values differ. The procedure presented has the potential of being applied not only to Granier's method, but to other heat-based sap flow systems that require a zero flow calibration, such as the Cermák et al. (1973) heat balance method and the T-max heat pulse system of Green et al. (2003).

Pharmacokinetics of cyclosporin in children with stable renal transplants.

PubMed

Tam, J C; Earl, J W; Willis, N S; Farquhar, J E; Nath, C E; Knight, J F; Hodson, E M

2000-12-01

Fourteen children, aged between 5 and 17 years, with stable renal graft function and stable cyclosporin A (CSA) trough levels (Cmin) were studied. They had been taking CSA 12-hourly since their transplant 1.5-9 years previously, with the average dose of Neoral being 6.4 (range 4.4-8.4) mg/kg per day. CSA whole blood levels were measured at 0, 20, and 40 min, and at 1, 1.5, 2, 2.5, 3, 4, 6, and 8 h following the morning dose using the Abbott TDx fluorescence polarization immunoassay. The area under the concentration time curve (AUC), clearance adjusted for bioavailability (CL/F), and steady-state volume of distribution adjusted for bioavailability (Vss/F) were determined using model-independent pharmacokinetic analysis. Delay time (Tdel), peak concentration (Cmax), time to peak concentration (Tmax), and Cmin were also determined and correlated with AUC and other parameters. The Tdel in absorption varied from 0.3 to 1.6 (mean 0.73) h, resulting in a similarly variable time to Tmax of 1-2.4 h (mean 1.59). Tmax was related to the age of the patient (Tmax = 0.027 age + 1.41, r2 = 0.56, P < 0.005). The AUC showed good correlation with Cmax (Cmax = 0.25 AUC + 423.32, r2 = 0.96, P < 0.0005). Cmax appears to be a more-suitable measure of exposure to CSA than Cmin. Prediction of Tmax from the age of the child may help to overcome the problem of when to collect blood for peak levels.

A critical remark on the applicability of E-OBS European gridded temperature data set for validating control climate simulations

NASA Astrophysics Data System (ADS)

Kyselý, Jan; Plavcová, Eva

2010-12-01

The study compares daily maximum (Tmax) and minimum (Tmin) temperatures in two data sets interpolated from irregularly spaced meteorological stations to a regular grid: the European gridded data set (E-OBS), produced from a relatively sparse network of stations available in the European Climate Assessment and Dataset (ECA&D) project, and a data set gridded onto the same grid from a high-density network of stations in the Czech Republic (GriSt). We show that large differences exist between the two gridded data sets, particularly for Tmin. The errors tend to be larger in tails of the distributions. In winter, temperatures below the 10% quantile of Tmin, which is still far from the very tail of the distribution, are too warm by almost 2°C in E-OBS on average. A large bias is found also for the diurnal temperature range. Comparison with simple average series from stations in two regions reveals that differences between GriSt and the station averages are minor relative to differences between E-OBS and either of the two data sets. The large deviations between the two gridded data sets affect conclusions concerning validation of temperature characteristics in regional climate model (RCM) simulations. The bias of the E-OBS data set and limitations with respect to its applicability for evaluating RCMs stem primarily from (1) insufficient density of information from station observations used for the interpolation, including the fact that the stations available may not be representative for a wider area, and (2) inconsistency between the radii of the areal average values in high-resolution RCMs and E-OBS. Further increases in the amount and quality of station data available within ECA&D and used in the E-OBS data set are essentially needed for more reliable validation of climate models against recent climate on a continental scale.

Coronal O VI emission observed with UVCS/SOHO during solar flares: Comparison with soft X-ray observations

NASA Astrophysics Data System (ADS)

Mancuso, S.; Giordano, S.; Raymond, J. C.

2016-06-01

In this work, we derive the O VI 1032 Å luminosity profiles of 58 flares, during their impulsive phase, based on off-limb measurements by the Ultraviolet Coronagraph Spectrometer (UVCS) aboard the SOlar and Heliospheric Observatory (SOHO). The O VI luminosities from the transition region plasma (here defined as the region with temperatures 5.0 ≤ log T (K) ≤ 6.0) were inferred from the analysis of the resonantly scattered radiation of the O VI coronal ions. The temperature of maximum ionization for O VI is log Tmax (K) = 5.47. By comparison with simultaneous soft X-ray measurements, we investigate the likely source (chromospheric evaporation, footpoint emission, or heated prominence ejecta) for the transition region emission observed during the impulsive phase. In our study, we find evidence of the main characteristics predicted by the evaporation scenario. Specifically, most O VI flares precede the X-ray peaks typically by several minutes with a mean of 3.2 ± 0.1 min, and clear correlations are found between the soft X-ray and transition region luminosities following power laws with indices ~ 0.7 ± 0.3. Overall, the results are consistent with transition region emission originating from chromospheric evaporation; the thermal X-ray emission peaks after the emission from the evaporation flow as the loops fill with hot plasma. Finally, we were able to infer flow speeds in the range ~20-100 km s-1 for one-third of the events, 14 of which showed speeds between 60 and 80 km s-1. These values are compatible with those found through direct spectroscopic observations at transition region temperatures by the EUV Imaging Spectrometer (EIS) on board Hinode.

California heat waves: their spatial evolution, variation, and coastal modulation by low clouds

NASA Astrophysics Data System (ADS)

Clemesha, Rachel E. S.; Guirguis, Kristen; Gershunov, Alexander; Small, Ivory J.; Tardy, Alexander

2018-06-01

We examine the spatial and temporal evolution of heat waves through California and consider one of the key modulating factors of summertime coastal climate—coastal low cloudiness (CLC). Heat waves are defined relative to daytime maximum temperature (Tmax) anomalies after removing local seasonality and capture unseasonably warm events during May—September. California is home to several diverse climate regions and characteristics of extreme heat events are also variable throughout these regions. Heat wave events tend to be shorter, but more anomalously intense along the coast. Heat waves typically impact both coastal and inland regions, although there is more propensity towards coastally trapped events. Most heat waves with a strong impact across regions start at the coast, proceed inland, and weaken at the coast before letting up inland. Typically, the beginning of coastal heat waves are associated with a loss of CLC, followed by a strong rebound of CLC starting close to the peak in heat wave intensity. The degree to which an inland heat wave is expressed at the coast is associated with the presence of these low clouds. Inland heat waves that have very little expression at the coast tend to have CLC present and an elevated inversion base height compared with other heat waves.

Epi-Side-Down Mounting of Interband Cascade Lasers for Army Applications

DTIC Science & Technology

2006-11-01

retain the principal advantage of electron recycling . However, unlike the QCL, the ICL relies on the cascading of interband optical transitions as...9.0 Cu 393 17 SiC 120 4 AlN 230 (high grade –Tsekoun 2006) 4.5, 4.3 Indium 83.7 24.8@ 20C 2 device ridge and an effective heat spreader ...65.3 K/W M271 epi-side down 8-μm x 1-mm mesa TmaxCW= 212K 4 were vital and survived multiple cryogenic to room temperature recyclings . Fig. 4

Enhanced late gas generation potential of petroleum source rocks via recombination reactions: Evidence from the Norwegian North Sea

NASA Astrophysics Data System (ADS)

Erdmann, Michael; Horsfield, Brian

2006-08-01

Gas generation in the deep reaches of sedimentary basins is usually considered to take place via the primary cracking of short alkyl groups from overmature kerogen or the secondary cracking of petroleum. Here, we show that recombination reactions ultimately play the dominant role in controlling the timing of late gas generation in source rocks which contain mixtures of terrigeneous and marine organic matter. These reactions, taking place at low levels of maturation, result in the formation of a thermally stable bitumen, which is the major source of methane at very high maturities. The inferences come from pyrolysis experiments performed on samples of the Draupne Formation (liptinitic Type II kerogen) and Heather Formation (mixed marine-terrigeneous Type III kerogen), both Upper Jurassic source rocks stemming from the Norwegian northern North Sea Viking Graben system. Non-isothermal closed system micro scale sealed vessel (MSSV) pyrolysis, non-isothermal open system pyrolysis and Rock Eval type pyrolysis were performed on the solvent extracted, concentrated kerogens of the two immature samples. The decrease of C 6+ products in the closed system MSSV pyrolysis provided the basis for the calculation of secondary gas (C 1-5) formation. Subtraction of the calculated secondary gas from the total observed gas yields a "remaining" gas. In the case of the Draupne Formation this is equivalent to primary gas cracked directly from the kerogen, as detected by a comparison with multistep open pyrolysis data. For the Heather Formation the calculated remaining gas formation profile is initially attributable to primary gas but there is a second major gas pulse at very high temperature (>550 °C at 5.0 K min -1) that is not primary. This has been explained by a recondensation process where first formed high molecular weight compounds in the closed system yield a macromolecular material that undergoes secondary cracking at elevated temperatures. The experiments provided the input for determination of kinetic parameters of the different gas generation types, which were used for extrapolations to a linear geological heating rate of 10 -11 K min -1. Peak generation temperatures for the primary gas generation were found to be higher for Heather Formation ( Tmax = 190 °C, equivalent to Ro appr. 1.7%) compared to Draupne Formation ( Tmax = 175 °C, equivalent to appr. Ro 1.3%). Secondary gas peak generation temperatures were calculated to be 220 °C for the Heather Formation and 205 to 215 °C for the Draupne Formation, respectively, with equivalent vitrinite reflectance values ( Ro) between 2.4% and 2.0%. The high temperature secondary gas formation from cracking of the recombination residue as detected for the Heather Formation is quantitatively important and is suggested to occur at very high temperatures ( Tmax approx. 250 °C) for geological heating rates. The prediction of a significant charge of dry gas from the Heather Formation at very high maturity levels has important implications for petroleum exploration in the region, especially to the north of the Viking Graben where Upper Jurassic sediments are sufficiently deep buried to have experienced such a process.

Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes.

PubMed

St Helen, Gideon; Havel, Christopher; Dempsey, Delia A; Jacob, Peyton; Benowitz, Neal L

2016-03-01

To measure the systemic retention of nicotine, propylene glycol (PG) and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. E-cigarette users recruited over the internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several times after use. San Francisco, California, USA. Thirteen healthy, experienced adult e-cigarette users (six females and seven males). Plasma nicotine was analyzed by gas chromatography-mass spectrometry (GC-MS/MS) and nicotine, VG and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. E-cigarettes delivered an average of 1.33 (0.87-1.79) mg [mean and 95% confidence interval (CI)] of nicotine, and 93.8% of the inhaled dose, 1.22 (0.80-1.66) was systemically retained. Average maximum plasma nicotine concentration (Cmax ) was 8.4 (5.4-11.5) ng/ml and time of maximal concentration (Tmax ) was 2-5 minutes. One participant had Tmax of 30 minutes. 84.4% and 91.7% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 beats per minute after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarette users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential. © 2015 Society for the Study of Addiction.

Intramuscular and rectal therapies of acute seizures.

PubMed

Leppik, Ilo E; Patel, Sima I

2015-08-01

The intramuscular (IM) and rectal routes are alternative routes of delivery for antiepileptic drugs (AEDs) when the intravenous route is not practical or possible. For treatment of acute seizures, the AED used should have a short time to maximum concentration (Tmax). Some AEDs have preparations that may be given intramuscularly. These include the benzodiazepines (diazepam, lorazepam, and midazolam) and others (fosphenytoin, levetiracetam). Although phenytoin and valproate have parenteral preparations, these should not be given intramuscularly. A recent study of prehospital treatment of status epilepticus evaluated a midazolam (MDZ) autoinjector delivering IM drug compared to IV lorazepam (LZP). Seizures were absent on arrival to the emergency department in 73.4% of the IM MDZ compared to a 63.4% response in LZP-treated subjects (p < 0.001 for superiority). Almost all AEDs have been evaluated for rectal administration as solutions, gels, and suppositories. In a placebo-controlled study, diazepam (DZP) was administered at home by caregivers in doses that ranged from 0.2 to 0.5 mg/kg. Diazepam was superior to placebo in reduced seizure frequency in children (p < 0.001) and in adults (p = 0.02) and time to recurrent seizures after an initial treatment (p < 0.001). Thus, at this time, only MZD given intramuscularly and DZP given rectally appear to have the properties required for rapid enough absorption to be useful when intravenous routes are not possible. Some drugs cannot be administered rectally owing to factors such as poor absorption or poor solubility in aqueous solutions. The relative rectal bioavailability of gabapentin, oxcarbazepine, and phenytoin is so low that the current formulations are not considered to be suitable for administration by this route. When administered as a solution, diazepam is rapidly absorbed rectally, reaching the Tmax within 5-20 min in children. By contrast, rectal administration of lorazepam is relatively slow, with a Tmax of 1-2h. The dependence of gabapentin on an active transport system, and the much-reduced surface area of the rectum compared with the small intestine, may be responsible for its lack of absorption from the rectum. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

Impaired T-wave amplitude adaptation to heart-rate induced by cardiac deconditioning after 5-days of head-down bed-rest

NASA Astrophysics Data System (ADS)

Caiani, Enrico G.; Pellegrini, Alessandro; Bolea, Juan; Sotaquira, Miguel; Almeida, Rute; Vaïda, Pierre

2013-10-01

The study of QT/RR relationship is important for the clinical evaluation of possible risk of acquired or congenital ventricular tachyarrhythmias. In the hypothesis that microgravity exposure could induce changes in the repolarization mechanisms, our aim was to test if a short 5-days strict 6° head-down bed-rest (HDBR) could induce alterations in the QT/RR relationship and spatial repolarization heterogeneity. Twenty-two healthy men (mean age 31±6) were enrolled as part of the European Space Agency HDBR studies. High fidelity (1000 Hz) 24 h Holter ECG (12-leads, Mortara Instrument) was acquired before (PRE), the last day of HDBR (HDT5), and four days after its conclusion (POST). The night period (23:00-06:30) was selected for analysis. X, Y, Z leads were derived and the vectorcardiogram computed. Selective beat averaging was used to obtain averages of P-QRS-T complexes preceded by the same RR (10 ms bin amplitude, in the range 900-1200 ms). For each averaged waveform (i.e., one for each bin), T-wave maximum amplitude (Tmax), T-wave area (Tarea), RTapex, RTend, ventricular gradient (VG) magnitude and spatial QRS-T angle were computed. Non-parametric Friedman test was applied. Compared to PRE, at HDT5 both RTapex and RTend resulted shortened (-4%), with a decrease in T-wave amplitude (-8%) and area (-13%). VG was diminished by 10%, and QRS-T angle increased by 14°. At POST, QT duration and area parameters, as well as QRS-T angle were restored while Tmax resulted larger than PRE (+5%) and VG was still decreased by 3%. Also, a marked loss in strength of the linear regression with RR was found at HDT5 in Tmax and Tarea, that could represent a new dynamic marker of increased risk for life-threatening arrhythmias. Despite the short-term HDBR, ventricular repolarization during the night period was affected. This should be taken into account in astronauts for risk assessment during space flight.

SU-D-18C-02: Feasibility of Using a Short ASL Scan for Calibrating Cerebral Blood Flow Obtained From DSC-MRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, P; Chang, T; Huang, K

2014-06-01

Purpose: This study aimed to evaluate the feasibility of using a short arterial spin labeling (ASL) scan for calibrating the dynamic susceptibility contrast- (DSC-) MRI in a group of patients with internal carotid artery stenosis. Methods: Six patients with unilateral ICA stenosis enrolled in the study on a 3T clinical MRI scanner. The ASL-cerebral blood flow (-CBF) maps were calculated by averaging different number of dynamic points (N=1-45) acquired by using a Q2TIPS sequence. For DSC perfusion analysis, arterial input function was selected to derive the relative cerebral blood flow (rCBF) map and the delay (Tmax) map. Patient-specific CF wasmore » calculated from the mean ASL- and DSC-CBF obtained from three different masks: (1)Tmax< 3s, (2)combined gray matter mask with mask 1, (3)mask 2 with large vessels removed. One CF value was created for each number of averages by using each of the three masks for calibrating the DSC-CBF map. The CF value of the largest number of averages (NL=45) was used to determine the acceptable range(< 10%, <15%, and <20%) of CF values corresponding to the minimally acceptable number of average (NS) for each patient. Results: Comparing DSC CBF maps corrected by CF values of NL (CBFL) in ACA, MCA and PCA territories, all masks resulted in smaller CBF on the ipsilateral side than the contralateral side of the MCA territory(p<.05). The values obtained from mask 1 were significantly different than the mask 3(p<.05). Using mask 3, the medium values of Ns were 4(<10%), 2(<15%) and 2(<20%), with the worst case scenario (maximum Ns) of 25, 4, and 4, respectively. Conclusion: This study found that reliable calibration of DSC-CBF can be achieved from a short pulsed ASL scan. We suggested use a mask based on the Tmax threshold, the inclusion of gray matter only and the exclusion of large vessels for performing the calibration.« less

Modelling growth of Penicillium expansum and Aspergillus niger at constant and fluctuating temperature conditions.

PubMed

Gougouli, Maria; Koutsoumanis, Konstantinos P

2010-06-15

The growth of Penicillium expansum and Aspergillus niger, isolated from yogurt production environment, was investigated on malt extract agar with pH=4.2 and a(w)=0.997, simulating yogurt, at isothermal conditions ranging from -1.3 to 35 degrees C and from 5 to 42.3 degrees C, respectively. The growth rate (mu) and (apparent) lag time (lambda) of the mycelium growth were modelled as a function of temperature using a Cardinal Model with Inflection (CMI). The results showed that the CMI can describe successfully the effect of temperature on fungal growth within the entire biokinetic range for both isolates. The estimated values of the CMI for mu were T(min)=-5.74 degrees C, T(max)=30.97 degrees C, T(opt)=22.08 degrees C and mu(opt)=0.221 mm/h for P. expansum and T(min)=10.13 degrees C, T(max)=43.13 degrees C, T(opt)=31.44 degrees C, and mu(opt)=0.840 mm/h for A. niger. The cardinal values for lambda were very close to the respective values for mu indicating similar temperature dependence of the growth rate and the lag time of the mycelium growth. The developed models were further validated under fluctuating temperature conditions using various dynamic temperature scenarios. The time-temperature conditions studied included single temperature shifts before or after the end of the lag time and continuous periodic temperature fluctuations. The prediction of growth at changing temperature was based on the assumption that after a temperature shift the growth rate is adopted instantaneously to the new temperature, while the lag time was predicted using a cumulative lag approach. The results showed that when the temperature shifts occurred before the end of the lag, they did not cause any significant additional lag and the observed total lag was very close to the cumulative lag predicted by the model. In experiments with temperature shifts after the end of the lag time, accurate predictions were obtained when the temperature profile included temperatures which were inside the region of growth, showing that the assumption that mu is adopted instantaneously to the current temperature is concrete. In contrast, for scenarios with temperatures close or outside the growth region the models overestimated growth, indicating that fungi were stressed by this type of temperature shifts. The present study provides useful data for understanding the behavior of P. expansum and A. niger at dynamic temperature conditions while the developed models can be used as effective tools in assessing the risk of fungal spoilage and predicting shelf life of foods. Copyright 2010. Published by Elsevier B.V.

Contribution of Modis Satellite Image to Estimate the Daily Air Temperature in the Casablanca City, Morocco

NASA Astrophysics Data System (ADS)

Bahi, Hicham; Rhinane, Hassan; Bensalmia, Ahmed

2016-10-01

Air temperature is considered to be an essential variable for the study and analysis of meteorological regimes and chronics. However, the implementation of a daily monitoring of this variable is very difficult to achieve. It requires sufficient of measurements stations density, meteorological parks and favourable logistics. The present work aims to establish relationship between day and night land surface temperatures from MODIS data and the daily measurements of air temperature acquired between [2011-20112] and provided by the Department of National Meteorology [DMN] of Casablanca, Morocco. The results of the statistical analysis show significant interdependence during night observations with correlation coefficient of R2=0.921 and Root Mean Square Error RMSE=1.503 for Tmin while the physical magnitude estimated from daytime MODIS observation shows a relatively coarse error with R2=0.775 and RMSE=2.037 for Tmax. A method based on Gaussian process regression was applied to compute the spatial distribution of air temperature from MODIS throughout the city of Casablanca.

Symmetricity analysis of time to peak parameter of indocyanine green dynamics

NASA Astrophysics Data System (ADS)

An, Yuri; Lee, Jungsul; Choi, Chulhee

2013-03-01

We have previously discovered that near-infrared optical imaging of indocyanine green (ICG) signal and analyzing its dynamics can be applied for measurement of blood perfusion rate and detection of Raynaud's phenomenon (RP). Especially, RP is closely associated with abnormal vasomotor responses and can progress to tissue necrosis due to excessively sustained vasoconstriction. Therefore, early detecting of RP is one of important implication to prevent tissue damage from peripheral vascular disorders. In the present study, we propose new analysis and scoring method of symmetricity of Tmax value of left and right extremities. Moreover, this symmetricity analysis can give further information about microvascular insufficiency. For validation of the proposed method, we tested whether the segmental and paired analysis of Tmax value (time-to-peak) of ICG dynamics can be used for sensitive diagnosis of microvascular abnormalities which cannot be detected by conventional methods. From the near-infrared images of diabetes mellitus patients with vascular complications, the trend of asymmetry in Tmax value was observed. We assumed that decreasing local blood perfusion by autonomic nerve dysfunction causes the asymmetric Tmax value of right and left feet. These results collectively indicate that the proposed method can be used as a useful diagnostic tool for RP or other microvascular disorders.

Music as an auditory stimulus in stroke patients.

PubMed

Antić, Sonja; Galinović, Ivana; Lovrendić-Huzjan, Arijana; Vuković, Vlasta; Jurasić, Miljenka-Jelena; Demarin, Vida

2008-01-01

Auditory stimulation increases mean blood flow velocity (MBFV) in the middle cerebral artery (MCA) in healthy individuals. Our aim was to monitor such changes in the affected MCA of patients with acute ischemic stroke (AIS). The study included 66 non-thrombolysed patients with AIS who were divided into groups according to National Institutes of Health Stroke Scale (NIHSS) score. Group I consisted of patients with NIHSS score 10 and group II with NIHSS score > or =11. Affected MCA was insonated with transcranial Doppler (TCD). MCA MBFVs were monitored during listening to music for 30 minutes. The first response of MBFV increase was measured as time (Tmax) and percentage of amplitude change (Amax). Pearson Chi-Square test was used. In 78.85% of patients there was a significant increase in MBFV compared to baseline values as a reaction to the music. There was no significant difference in Tmax or Amax between the two groups. However, a trend of longer Tmax was observed with every 2 NIHSS score increase. Music is an auditory stimulus in stroke patients and can be measured with TCD as MCA MBFV increase. Although our study showed no significant change of reaction time with the severity of stroke, a trend of prolonged Tmax was observed with NIHSS score increase.

High-pressure granulites in the Fuping Complex of the central North China Craton: Metamorphic P-T-t evolution and tectonic implications

NASA Astrophysics Data System (ADS)

Qian, Jiahui; Yin, Changqing; Zhang, Jian; Ma, Li; Wang, Luojuan

2018-04-01

Mafic granulites in the Fuping Complex occur as lenses or boudins within high-grade TTG (Trondhjemite-Tonalite-Granodiorite) gneisses. Petrographic observations reveal four generations of mineral assemblage in the granulites: an inclusion assemblage of hornblende + plagioclase + ilmenite + quartz within garnet core; an inferred peak assemblage composed of garnet ± hornblende + plagioclase + clinopyroxene + rutile/ilmenite + quartz; a decompression assemblage characterized by symplectites of clinopyroxene ± orthopyroxene + plagioclase, coronae of plagioclase ± clinopyroxene ± hornblende around embayed garnet porphyroblasts or a two-pyroxene association; and a late amphibolite-facies retrogressive assemblage. Two representative samples were used for pseudosection modeling in NCFMASHTO model system to determine their metamorphic evolution. The results show that these granulites experienced a high-pressure stage of metamorphism with peak P-T conditions of 12-13 kbar and 760-800 °C (Pmax) and a post-peak history under P-T conditions of ∼9.0 kbar and 805-835 °C (Tmax), indicating a nearly isothermal decompression process (ITD) with a slight heating. Metamorphic evolution from the Pmax to the Tmax is predicted to be dominated by garnet breakdown through continuous metamorphic reactions of garnet + quartz ± diopside = hornblende + plagioclase + liquid and garnet + quartz + hornblende = plagioclase + diopside + liquid + orthopyroxene. Further metamorphic evolution after the Tmax is dominated by cooling, suggesting that high-pressure (HP) granulites may also exist in the Fuping Complex. Metamorphic zircons in the Fuping HP mafic granulites have left inclined REE patterns, Ti contents of 1.68-6.88 ppm and crystallization temperatures of 602-712 °C. SIMS zircon U-Pb dating on these zircons yields 207Pb/206Pb ages of 1891 ± 14 Ma and 1849 ± 6 Ma, interpreted to represent the cooling stage of metamorphism. The P-T-t evolution of the Fuping HP mafic granulites records well the protracted Paleoproterozoic orogenic event occurred in the central North China Craton.

Numerical Modeling of Hydrothermal Circulation at the Longqi-1 Field: Southwest Indian Ridge

NASA Astrophysics Data System (ADS)

Guo, Z.; Lowell, R. P.; Tao, C.; Rupke, L.; Lewis, K. C.

2017-12-01

The Longqi-1(Dragon Flag) hydrothermal field is the first high-temperature hydrothermal system observed on the ultra-slow spreading Southwest Indian Ridge. Hydrothermal vents with temperatures near 380 °C are localized by detachment faulting within which extensional deformation likely increases permeability to provide preferred pathways for hydrothermal discharge. To better understand the Longqi-1 circulation system, we construct a 2-D numerical simulations in a NaCl- H2O fluid constrained by key observational data, such as vent temperature and heat output, crust structure derived from seismic data, and fault zone geometry deduced from seismicity. Heat output from AUV surveys is estimated to be » 300 ± 100 MW, and this value, in conjunction with vent temperature was used with the single-pass modeling approach to obtain an average permeability of 10-13 m-2 within the fault zone. In analogy with other fault-controlled hydrothermal systems such as Logatchev-1 we assume a lower background permeability of 10-14 m-2. The top boundary of the system is permeable and maintained at constant seafloor pressure, which is divided into two parts by the detachment fault. The pressure of the southern part is lower than the northern part to simulate the effect of the seafloor topography. The top boundary is upstream weighted to allow high temperature fluid to exit, while recharging fluid is maintained at 10°C. The bottom boundary is impermeable and is given a fixed temperature distribution at a depth of 7 km below the seafloor. The highest value Tmax is maintained over a distance given lateral distance and decreases linearly towards two ends to 300 °C. The salinity is set to 3.2 wt. % NaCl, and the simulations are assumed to be single phase. The results show that with a 7 km deep circulation system, Tmax = 550 oC gives a reasonable temperature and heat output of venting plume.We infer that the observed high salinity results from serpentinization reactions. Assuming all salinity in excess of seawater comes from uptake of H2O during serpentinization, we can estimate the rate of reaction and heat release of serpentinezation based on a simplified reaction equation, observed heat output and salinity data. The estimated rate of heat release during serpentinization is 20 MW. This is approximately 10% of the heat output of Dragon Flag vent field.

Model and Scenario Variations in Predicted Number of Generations of Spodoptera litura Fab. on Peanut during Future Climate Change Scenario

PubMed Central

Srinivasa Rao, Mathukumalli; Swathi, Pettem; Rama Rao, Chitiprolu Anantha; Rao, K. V.; Raju, B. M. K.; Srinivas, Karlapudi; Manimanjari, Dammu; Maheswari, Mandapaka

2015-01-01

The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM) of future data on daily maximum (T.max), minimum (T.min) air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1). This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF) -2020, Distant future (DF)-2050 and Very Distant future (VDF)—2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1–2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18–22% over baseline. Analysis of variance (ANOVA) was used to partition the variation in the predicted number of generations and generation time of S. litura on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%), model (1.74%) and scenario (0.74%). The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of S. litura may increase due to projected increase in temperatures in future climate change periods. PMID:25671564

Integrated Field Analyses of Thermal Springs

NASA Astrophysics Data System (ADS)

Shervais, K.; Young, B.; Ponce-Zepeda, M. M.; Rosove, S.

2011-12-01

A group of undergraduate researchers through the SURE internship offered by the Southern California Earthquake Center (SCEC) have examined thermal springs in southern Idaho, northern Utah as well as mud volcanoes in the Salton Sea, California. We used an integrated approach to estimate the setting and maximum temperature, including water chemistry, Ipad-based image and data-base management, microbiology, and gas analyses with a modified Giggenbach sampler.All springs were characterized using GISRoam (tmCogent3D). We are performing geothermometry calculations as well as comparisons with temperature gradient data on the results while also analyzing biological samples. Analyses include water temperature, pH, electrical conductivity, and TDS measured in the field. Each sample is sealed and chilled and delivered to a water lab within 12 hours.Temperatures are continuously monitored with the use of Solinst Levelogger Juniors. Through partnership with a local community college geology club, we receive results on a monthly basis and are able to process initial data earlier in order to evaluate data over a longer time span. The springs and mudpots contained microbial organisms which were analyzed using methods of single colony isolation, polymerase chain reaction, and DNA sequencing showing the impact of the organisms on the springs or vice versa. Soon we we will collect gas samples at sites that show signs of gas. This will be taken using a hybrid of the Giggenbach method and our own methods. Drawing gas samples has proven a challenge, however we devised a method to draw out gas samples utilizing the Giggenbach flask, transferring samples to glass blood sample tubes, replacing NaOH in the Giggenbach flask, and evacuating it in the field for multiple samples using a vacuum pump. We also use a floating platform devised to carry and lower a levelogger, to using an in-line fuel filter from a tractor in order to keep mud from contaminating the equipment.The use of raster imagery on the iPad2 has drastically changed how we plan and conduct our sampling trips. Orthoimagery onto the iPad2 is viewed with GISRoam and we use that imagery to help guide us toward points that we wish to visit. GISRoam was used to plot spatially correlated data points while in the field, estimate latitude and longitude, and record aforementioned data. A key factor to our success is up to the minute collaboration between all participants. Google's suite of services provides phone number for landowners, web site hosting, and the most crucial implementation for sharing data in real time has been the beta google Fusion Table. This spreadsheet allows for the incorporation of images, sample data and GPS location to be displayed as a kml file to be viewed in Google maps. This ability to modify and recognize data points in real time has made us more effective in the field, and in documenting progress in the lab. This workflow has enabled us to sample over 30 springs in 2 months, find 10 new springs, and estimate Tmax for 14 sites.By the end of 3 months we anticipate having water chemistry, isotope samples, gas samples, and Tmax determinations for 30 springs in the two study areas.

Relationships between extraction and metabolism of glucose, blood flow, and tissue blood volume in regions of rat brain.

PubMed

Cremer, J E; Cunningham, V J; Seville, M P

1983-09-01

Studies were made on the relationships between the rate of glucose metabolism, the transport of glucose between plasma and brain, cerebral blood flow, and blood content. Conscious control rats were compared with rats with intense tremors induced with cismethrin. The influence of plasma glucose concentration was studied by fasting some animals overnight prior to the induction of tremors. Mean plasma glucose was 8.83 mM in controls, 12.57 mM in fed rats with tremors, and 4.94 mM in rats fasted overnight prior to induction of tremors. Of 12 brain regions studied, nine showed an increased rate of glucose utilization in both fed and fasted trembling rats. Cerebellum had the highest percentage increase (200%). Rates of unidirectional glucose influx in fed trembling rats were significantly greater than those in controls in eight regions. In fasted animals, rates were the same as in controls, except in cerebellum, where it was 1.6 times higher. These high rates of glucose influx at low plasma glucose concentrations were indicative of a change in kinetic parameters of glucose transport. Unidirectional glucose influx rates were transformed to estimates of maximal transport rates (Tmax), based on the Michaelis-Menten equation. Average plasma glucose concentrations in regional capillaries (c) were calculated and shown to be maintained at values close to arterial plasma glucose concentrations (Ca), in all brain regions of each group. In trembling rats, Tmax for each brain region was higher than that in controls. In fasted rats with tremors, Tmax was higher in several brain regions than in fed rats. Tmax in cerebellum was 3.37, 4.71, and 7.89 mumol g-1 min-1 in control, fed trembling, and fasted trembling rats, respectively. Blood flow increased significantly in all regions in rats with tremors and was higher in fasted than in fed animals. There was only a weak correlation between blood flow and Tmax. Blood content of several regions increased in rats with tremors, and there was a strong correlation between Tmax and tissue blood volume. Results are consistent with localized regulatory links between blood flow, capillary surface area, and glucose transport in response to metabolic demand and hypoglycaemia. These involve changes in the linear velocity of blood through capillaries and in the extent of capillary recruitment.

Urban climate effects on extreme temperatures in Madison, Wisconsin, USA

NASA Astrophysics Data System (ADS)

Schatz, Jason; Kucharik, Christopher J.

2015-09-01

As climate change increases the frequency and intensity of extreme heat, cities and their urban heat island (UHI) effects are growing, as are the urban populations encountering them. These mutually reinforcing trends present a growing risk for urban populations. However, we have limited understanding of urban climates during extreme temperature episodes, when additional heat from the UHI may be most consequential. We observed a historically hot summer and historically cold winter using an array of up to 150 temperature and relative humidity sensors in and around Madison, Wisconsin, an urban area of population 402 000 surrounded by lakes and a rural landscape of agriculture, forests, wetlands, and grasslands. In the summer of 2012 (third hottest since 1869), Madison’s urban areas experienced up to twice as many hours ⩾32.2 °C (90 °F), mean July TMAX up to 1.8 °C higher, and mean July TMIN up to 5.3 °C higher than rural areas. During a record setting heat wave, dense urban areas spent over four consecutive nights above the National Weather Service nighttime heat stress threshold of 26.7 °C (80 °F), while rural areas fell below 26.7 °C nearly every night. In the winter of 2013-14 (coldest in 35 years), Madison’s most densely built urban areas experienced up to 40% fewer hours ⩽-17.8 °C (0 °F), mean January TMAX up to 1 °C higher, and mean January TMIN up to 3 °C higher than rural areas. Spatially, the UHI tended to be most intense in areas with higher population densities. Temporally, both daytime and nighttime UHIs tended to be slightly more intense during more-extreme heat days compared to average summer days. These results help us understand the climates for which cities must prepare in a warming, urbanizing world.

SO 2-Resistant Immobilized Amine Sorbents for CO 2 Capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tumuluri, Uma

2014-01-01

The solid amine sorbent for CO 2 capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO 2 capture capacity or low stability in the flue gas environment. This project is aimed at developing a SO 2-resistant solid amine sorbent for capturing CO 2 from coal–fired power plants with SCR/FGD which emits SO 2ranging from 15 to 30 ppm and NO ranging from 5 to 10 ppm. The amine sorbent we developed in a previous project degraded rapidly with 65% decrease in themore » initial capture capacity in presence of 1% SO 2. This amine sorbent was further modified by coating with polyethyleneglycol (PEG) to increase the SO 2-resistance. Polyethylene glycol (PEG) was found to decrease the SO 2-amine interaction, resulting in the decrease in the maximum SO desorption temperature (Tmax ) of amine sorbent. The PEG-coated amine sorbent exhibited higher stability with only 40% decrease in the initial capture capacity compared to un-coated amine sorbents. The cost of the solid amine sorbent developed in this project is estimated to be less than $7.00/lb; the sorbent exhibited CO 2 capture capacity more than 2.3 mmol/g. The results of this study provided the scientific basis for further development of SO 2-resistant sorbents.« less

Exposure assessment of aluminum arc welding radiation.

PubMed

Peng, Chiung-yu; Lan, Cheng-hang; Juang, Yow-jer; Tsao, Ta-ho; Dai, Yu-tung; Liu, Hung-hsin; Chen, Chiou-jong

2007-10-01

The purpose of this study is to evaluate the non-ionizing radiation (NIR) exposure, especially optical radiation levels, and potential health hazard from aluminum arc welding processes based on the American Conference of Governmental Industrial Hygienists (ACGIH) method. The irradiance from the optical radiation emissions can be calculated with various biological effective parameters [i.e., S(lambda), B(lambda), R(lambda)] for NIR hazard assessments. The aluminum arc welding processing scatters bright light with NIR emission including ultraviolet radiation (UVR), visible, and infrared spectra. The UVR effective irradiance (Eeff) has a mean value of 1,100 microW cm at 100 cm distance from the arc spot. The maximum allowance time (tmax) is 2.79 s according to the ACGIH guideline. Blue-light hazard effective irradiance (EBlue) has a mean value of 1840 microW cm (300-700 nm) at 100 cm with a tmax of 5.45 s exposure allowance. Retinal thermal hazard effective calculation shows mean values of 320 mW cm(-2) sr(-1) and 25.4 mW (cm-2) (380-875 nm) for LRetina (spectral radiance) and ERetina (spectral irradiance), respectively. From this study, the NIR measurement from welding optical radiation emissions has been established to evaluate separate types of hazards to the eye and skin simultaneously. The NIR exposure assessment can be applied to other optical emissions from industrial sources. The data from welding assessment strongly suggest employees involved in aluminum welding processing must be fitted with appropriate personal protection devices such as masks and gloves to prevent serious injuries of the skin and eyes upon intense optical exposure.

Pharmacokinetic characterization of three novel 4-mg nicotine lozenges
.

PubMed

Sukhija, Manpreet; Srivastava, Reena; Kaushik, Aditya

2018-03-01

Nicotine replacement therapy (NRT) increases the probability of smoking cessation. This study was conducted to determine if three prototype 4-mg nicotine lozenges produced locally in India were bioequivalent to a globally marketed reference product, Nicorette® 4-mg nicotine lozenge. Healthy adult smokers (N = 39) were treated with three prototype 4-mg nicotine lozenges in comparison with a reference 4-mg lozenge in this single-center, randomized, open-label, single-dose, 4-way crossover study. Pharmacokinetic sampling was obtained to test for bioequivalence using maximal plasma concentration (Cmax) and extent of absorption (AUC0-t). Secondarily, AUC;0-∞, time to maximal plasma concentration (tmax), half-life (T1/2), elimination rate constant (Kel), and safety of the prototype lozenges versus the reference lozenge were compared. Each prototype 4-mg nicotine lozenge was found to be bioequivalent to the reference 4-mg nicotine lozenge based on the ratio of geometric means and 90% confidence intervals for Cmax, AUC0-t, and AUC;0-∞. Although tmax; was significantly longer for prototype III, all four lozenges achieved maximum plasma nicotine concentrations at a median of 1.5 hours. The safety profiles of the three prototype 4-mg lozenges did not differ from that of the 4-mg reference product. Each prototype 4-mg nicotine lozenge was bioequivalent to the reference 4-mg nicotine lozenge and was well tolerated. Furthermore, as these bioequivalent prototypes differed in in-vitro dissolution profiles, these data suggest that performance from the in -vitro method deployed is not a firm predictor of pharmacokinetic behavior.
.

Reproductive characteristics and population decline of four species of skate (Rajidae) off the eastern coast of Canada.

PubMed

Mcphie, R P; Campana, S E

2009-07-01

Four of the most common species of skate (Rajidae) were studied off eastern Canada to determine if their reproductive characteristics were linked to their population trajectories. The fecundity of the winter skate Leucoraja ocellata, the little skate Leucoraja erinacea, the thorny skate Amblyraja radiata and the smooth skate Malacoraja senta averaged between 41 and 56 egg cases per year for each species. For all species but L. ocellata, males matured at larger sizes and at later ages than females. Theoretical rates of population increase for non-equilibrium populations of L. ocellata (c. 0.07), M. senta (c. 0.14) and L. erinacea and A. radiata (c. 0.20) were low compared to most fishes, indicating that north-west Atlantic skates are intrinsically unproductive, yet are theoretically capable of supporting low-level fisheries. Nevertheless, the results of 36 years of research surveys indicate that the abundance of mature L. ocellata, A. radiata and M. senta all decreased by >90% since 1970, indicating that past fishing mortality (both directed and undirected) has outstripped the net productivity of the skate populations on the eastern Scotian Shelf. The relationship between maximum age (t(max)) and age of maturity (t(mat)) was a better predictor of population growth rate than was body size, with the species exhibiting the highest ratios of t(mat) :t(max) (L. ocellata = 0.68, M. senta = 0.66) having the lowest predicted population growth rates. L. ocellata appears to have the lowest productivity and has experienced the greatest population decline, thus raising concerns over its future status.

The detection and quantification of the defects in adhesive bonded joints of the piezoelectric sensors by infrared thermographic nondestructive testing

NASA Astrophysics Data System (ADS)

Vinod, P. N.; Joseph, Sherin; John, Reji

2017-04-01

In this paper, efficacy of pulsed thermography technique has been explored for the first time for the detection and quantification of the subsurface defects present in the rubber-encapsulated piezoelectric sensors. Initial experiments were performed on adhesively bonded joints of the rubber/Al or rubber/PZT control samples to find out an optimum acquisition time for the 3-mm rubber encapsulants. Thermographic measurements were performed in the reflection mode and acquired thermal images were analysed and processed images were described in terms of the phase images. The defective regions are identified as delamination of the adhesive joints at the interface of rubber and PZT stacks, and presence of porosity in the encapsulation in the inspected hydrophone. The defect depths of the observed anomalies were calculated empirically from the plots of the peak time of thermal contrast (tmax) maximum and thermal contrast maximum (Cmax) for a particular defect. The estimated defect depths of the prominent porosity observed in the PZT hydrophone are found nearly 1 mm from the surface.

[Experimental study of the basic pharmacokinetic characteristics of dipeptide carnosine and its efficiency of penetration into brain tissues].

PubMed

Sariev, A K; Abaimov, D A; Tankevich, M V; Pantyukhova, E Yu; Prokhorov, D I; Fedorova, T N; Lopachev, A V; Stvolinskii, S L; Konovalova, E V; Seifulla, R D

2015-01-01

We have used an original chromatography/mass spectrometry technique to study the pharmacokinetics of dipeptide carnosine in C57 Black/6 mice after intra-peritoneal administration of the drug at a dose of 1 g/kg. The basic pharmacokinetic characteristics of carnosine were measured the in the blood and brain. The obtained concentration-time curve has a biexponential character. It is shown that the maximum concentration of carnosine in the blood plasma is Cmax = 1081.75 ± 124.24 μg/mL and it is achieved in a time interval of Tmax = 0.25 h. We showed that i.p. administration of exogenous carnosine could significantly increase the concentration of that substance in the brain. Tissue availability of dipeptide carnosine for brain tissue is relatively good and constitutes 59% from the total amount of blood carnosine. It was found that the maximum concentration of carnosine in the brain occurs at the sixth hour after i.p. administration when the concentration of drug in the blood is minimal.

Effect of immobilization and retraining on torque-velocity relationship of human knee flexor and extensor muscles.

PubMed

Labarque, V L; Eijnde, B Op 't; Van Leemputte, M

2002-01-01

The effect of 2 weeks immobilization of the uninjured right knee and 10 weeks of retraining on muscle torque-velocity characteristics was investigated in nine young subjects. Left and right knee extension and flexion maximal voluntary isometric torque (Tmax) and dynamic torque at 60 degrees s(-1) (T60) and 180 degrees x s(-1) (T180) were measured before (PRE) and after immobilization (POST) and after 3 (R3) and 10 (R10) weeks of dynamic retraining. The torque-velocity relationship was quantified by expressing T60 and T180 relative to Tmax (NT60 and NT180, respectively). For the right extensor muscles, percutaneous biopsy samples were obtained from the vastus lateralis muscle and fibre type distribution was measured. POST extension and flexion torque (mean of Tmax, T60 and T180) decreased by 27% and 11%, respectively. During the course of the experiment, the changes in NT60 and NT180 were similar. POST extensor muscle NTV (mean of NT60 and NT180) was decreased significantly (12%, P<0.05), but no significant change was found for flexor muscle NTV (+ 3%). At R3 Tmax, dynamic torque and NTV were restored to normal. Unlike isometric torque, NTV did not change from R3 to R10. No changes in fibre type distribution were found. The adaptation of muscle length is suggested as the mechanism to explain the change in NTV.

A study on the magnetic susceptibilities and optical absorption spectra on single crystals of Gd(III) pyrogermanate

NASA Astrophysics Data System (ADS)

Kundu, T.; Ghosh, D.; Wanklyn, B. M.

1990-04-01

The paper reports for the first time the experimental results of the measurements of magnetic susceptibilities ( K⊥ and K|) and their anisotropy (Δ K) between 300 and 21.8 K and the optical absorption spectra (UV region) at 12.5 K on single crystals of gadolinium pyrogermanate (GdPG). The anisotropy, which is only 211×10 -6 emu/mol at room temperature and increases by two orders of magnitude at 21 K, is predominantly a crystal field (CF) effect on the 8S {7}/{2} ground term, through higher order perturbations. Interpretation of the observed magnetic data was carried out by considering a conventional spin Hamiltonian ( Hs) to derive expressions for K⊥ and K| in terms of four effective crystal field parameters (ECFP). The value s of ECFP were varied to obtain a very close fitting between the theoretical and experimental values of K⊥, K|, δ K and K¯ The splitting of the 8S {7}/{2} term corresponding to these values of ECFP was found to be large, which suggests a strong CF effect in GdPG, as also observed in other RPG crystal studied earlier. The thermal characteristics of the magnetic anisotropy below 30 K deviate by about 5% which could not be explained by CF effects alone. A series expansion method was adopted to analyse the results of K⊥ and K| below 30 K, however the corresponding coefficient B2α and B3α were observed t o be unusually high indicating the presence of CF effect even in this temperature region. The Schottky specific heat, Csch, between 300 and 21 K for GdPG has been calculated and this shows a maximum at Tmax=17 K.

Imaging technique for real-time temperature monitoring during cryotherapy of lesions.

PubMed

Petrova, Elena; Liopo, Anton; Nadvoretskiy, Vyacheslav; Ermilov, Sergey

2016-11-01

Noninvasive real-time temperature imaging during thermal therapies is able to significantly improve clinical outcomes. An optoacoustic (OA) temperature monitoring method is proposed for noninvasive real-time thermometry of vascularized tissue during cryotherapy. The universal temperature-dependent optoacoustic response (ThOR) of red blood cells (RBCs) is employed to convert reconstructed OA images to temperature maps. To obtain the temperature calibration curve for intensity-normalized OA images, we measured ThOR of 10 porcine blood samples in the range of temperatures from 40°C to ?16°C and analyzed the data for single measurement variations. The nonlinearity (?Tmax) and the temperature of zero OA response (T0) of the calibration curve were found equal to 11.4±0.1°C and ?13.8±0.1°C, respectively. The morphology of RBCs was examined before and after the data collection confirming cellular integrity and intracellular compartmentalization of hemoglobin. For temperatures below 0°C, which are of particular interest for cryotherapy, the accuracy of a single temperature measurement was ±1°C, which is consistent with the clinical requirements. Validation of the proposed OA temperature imaging technique was performed for slow and fast cooling of blood samples embedded in tissue-mimicking phantoms.

Imaging technique for real-time temperature monitoring during cryotherapy of lesions

PubMed Central

Petrova, Elena; Liopo, Anton; Nadvoretskiy, Vyacheslav; Ermilov, Sergey

2016-01-01

Abstract. Noninvasive real-time temperature imaging during thermal therapies is able to significantly improve clinical outcomes. An optoacoustic (OA) temperature monitoring method is proposed for noninvasive real-time thermometry of vascularized tissue during cryotherapy. The universal temperature-dependent optoacoustic response (ThOR) of red blood cells (RBCs) is employed to convert reconstructed OA images to temperature maps. To obtain the temperature calibration curve for intensity-normalized OA images, we measured ThOR of 10 porcine blood samples in the range of temperatures from 40°C to −16°C and analyzed the data for single measurement variations. The nonlinearity (ΔTmax) and the temperature of zero OA response (T0) of the calibration curve were found equal to 11.4±0.1°C and −13.8±0.1°C, respectively. The morphology of RBCs was examined before and after the data collection confirming cellular integrity and intracellular compartmentalization of hemoglobin. For temperatures below 0°C, which are of particular interest for cryotherapy, the accuracy of a single temperature measurement was ±1°C, which is consistent with the clinical requirements. Validation of the proposed OA temperature imaging technique was performed for slow and fast cooling of blood samples embedded in tissue-mimicking phantoms. PMID:27822579

Comparative bioavailability of two novel coenzyme Q10 preparations in humans.

PubMed

Joshi, S S; Sawant, S V; Shedge, A; Halpner, A D

2003-01-01

To determine the absorptive properties of 2 novel coenzyme Q10 preparations, a fast-melting tablet and an effervescent tablet, compared with currently available formulations. In the first trial, the absorptive properties of 4 different coenzyme Q10 preparations (fast-melting, effervescent, soft gelatin, and powder-filled hard shell) were studied in a randomized, single-dose, crossover study. Twenty-four male subjects were given a 60 mg dose of coenzyme Q10 and plasma coenzyme Q10 was measured over the next 12 hours. Pharmacokinetic properties including area under the curve (AUC), maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax) and elimination half-life (t 1/2) were measured. In a separate single-dose study, the absorptive characteristics of a different coenzyme Q10 soft gel (Q-Gel) were studied in 6 male subjects. Area under the curve (microg/ml x h) for the fast-melting and effervescent formulations, while marginally greater, was not significantly different when compared to the soft gelatin and powder-filled preparations, 5.4 +/- 1.04 (110%) and 5.5 +/- 0.589 (112%) versus 5.0 +/- 0.859 (102%) and 4.9 +/- 0.812 (100%), respectively. Cmax for the 2 novel formulations was also not statistically different from the soft gelatin or powder-filled preparations, 0.87 +/- 0.14 and 0.86 +/- 0.074 versus 0.70 +/- 0.010 and 0.81 +/- 0.159 (microg/ml). Tmax however, was significantly shorter for the fast-melting and effervescent formulations compared with the soft gel and powder-filled forms, 1.3 +/- 0.348 and 2.0 +/- 0.552 versus 3.7 +/- 0.702 and 4.1 +/- 0.993 (h), respectively. The results of the second trial were similar to those of the powder-filled and soft gel formulations from the first study. The novel fast-melting and effervescent formulations provide a more rapid delivery of CoQ10 to the blood while exhibiting a similar AUC compared with current formulations. The potential clinical significance of this finding should be further evaluated.

Red wine-cisapride interaction: comparison with grapefruit juice.

PubMed

Offman, E M; Freeman, D J; Dresser, G K; Munoz, C; Bend, J R; Bailey, D G

2001-07-01

Our objective was to compare the interactions of red wine and grapefruit juice with cisapride. The oral pharmacokinetics of cisapride, its norcisapride metabolite, and electrocardiographic QTc interval were determined over a 24-hour period after administration of cisapride 10 mg with 250 mL grapefruit juice, red wine (cabernet sauvignon), or water in a randomized 3-way crossover study in 12 healthy men. The cisapride area under the concentration-time curve (AUC) and the maximum plasma drug concentration after single-dose administration (C(max)) with grapefruit juice were 151% (P <.01) and 168% (P <.001), respectively, of those with water. The increase in cisapride AUC and C(max) was variable among individuals; however, cisapride AUC and C(max) were enhanced by the same proportion. The time to reach maximum concentration after drug administration (t(max)) and the apparent elimination half-life (t((1/2)) for cisapride and the pharmacokinetics of norcisapride were not altered. Norcisapride/cisapride ratios were reduced. Cisapride AUC and C(max) with red wine were 115% (difference not statistically significant) and 107% (difference not statistically significant), respectively, of those with water. The cisapride t(max) was slightly longer. Cisapride t((1/2)) and norcisapride pharmacokinetics were not different. The norcisapride/cisapride ratio at cisapride C(max) was lower. One subject had a doubling in cisapride AUC and C(max) and a decrease in norcisapride/cisapride ratios with red wine and also had the largest interaction with grapefruit juice. QTc interval was unchanged in all treatment groups and individuals. A single glass of grapefruit juice produced an individual-dependent variable increase in the systemic availability of cisapride by inhibition of intestinal cytochrome P450 3A4 (CYP3A4) activity. The identical volume of red wine caused only minor changes in cisapride pharmacokinetics despite some inhibition of CYP3A4 in most individuals. However, even this amount of red wine may cause a marked interaction similar to that for grapefruit juice in individuals with a preexisting high intestinal CYP3A4 content.

Genetic variation and effects of candidate-gene polymorphisms on coagulation properties, curd firmness modeling and acidity in milk from Brown Swiss cows.

PubMed

Cecchinato, A; Chessa, S; Ribeca, C; Cipolat-Gotet, C; Bobbo, T; Casellas, J; Bittante, G

2015-07-01

The aims of this study were to estimate the genetic variation of traditional milk coagulation properties (MCPs), milk acidity, curd firmness (CF) modeled on time t (CF(t) ; comprising: RCT(eq), rennet coagulation time estimated from the equation; CF(P), the asymptotic potential curd firmness; k(CF), the curd firming instant rate constant; and k(SR), the syneresis instant rate constant) and maximum CF traits (MCF; comprising CF(max), the maximum CF value; and tmax, the time of attainment). Furthermore, we investigated 96 single nucleotide polymorphisms (SNPs) from 54 candidate genes, testing their associations with the above-listed traits. Milk and blood samples were collected from 1271 cows (each sampled once) from 85 herds. Genotyping was performed using a custom Illumina VeraCode GoldenGate approach. A Bayesian linear animal model (including the effects of herd, days in milk, parity and additive polygenic effects) was used to estimate the genetic parameters of the studied traits. The same model with the addition of the SNP genotype effect was used for our association analysis. The heritability estimates of CF t and the MCF traits (RCT(eq)=0.258; k(CF)=0.230; CF(max)=0.191; t(max)=0.278) were similar to those obtained using traditional MCPs (0.187 to 0.267), except for the lower estimates for CF(P) (0.064) and k(SR) (0.077). A total of 13 of the 51 tested SNPs had relevant additive effects on at least one trait. We observed associations between MCPs and SNPs in the genes encoding ATP-binding cassette sub-family G member 2 (ABCG2), chemokine ligand 2 (CCL2), growth hormone 1 (GH1), prolactin (PRL) and toll-like receptor 2 (TLR2). Whereas, CF(t) and the MCF traits were associated with polymorphisms in the α-s1-casein (CSN1S1), β-casein (CSN2), GH1, oxidized low-density lipoprotein receptor 1 (OLR1), phospholipase C β1 (PLCB1), PRL and signal transducer and activator of transcription 5A (STAT5A) genes.

An investigation of the safety and pharmacokinetics of the novel TRPV1 antagonist XEN-D0501 in healthy subjects

PubMed Central

Round, Patrick; Priestley, Anthony; Robinson, Jan

2011-01-01

AIMS XEN-D0501, a novel TRPV1 antagonist, is being developed to treat overactive bladder. This study investigated the safety and pharmacokinetics of repeat-dose XEN-D0501 in healthy subjects. METHODS The study was conducted in two parts. Part 1 was a double-blind, randomized, placebo-controlled, two-way crossover study in three cohorts of 12 young male subjects. Each subject received XEN-D0501 and placebo (in random order) twice daily for 13 days, with a final single dose on day 14. Doses of 1, 2.5 and 5 mg XEN-D0501 were investigated. Part 2 was an open-label, randomized, two-way crossover study in male and female subjects (45 to 65 years). Subjects received single doses of 5 mg XEN-D0501 under fasted and fed conditions in random order. Blood sampling and safety assessments were conducted throughout the study. RESULTS XEN-D0501 was rapidly absorbed (tmax generally 0.5–4 h post dose). XEN-D0501 exposure increased less than proportionally to dose over the range studied and exhibited minimal accumulation with twice daily dosing. Food had no clinically relevant effects on the pharmacokinetics of XEN-D0501. There were no severe or serious adverse events and all doses were well tolerated. A dose-related increase in body temperature was seen with XEN-D0501 which attenuated over time. Differences from placebo in mean maximum core body temperatures were 0.22°C, 0.5°C and 0.74°C following 1 mg, 2.5 mg and 5 mg twice daily XEN-D0501. The observed increase in body temperature was not considered to be of clinical concern. CONCLUSIONS XEN-D0501 appeared safe and well tolerated at doses up to 5 mg twice daily for 14 days in healthy subjects. PMID:21676011

Nova Lupi 2011

NASA Astrophysics Data System (ADS)

Waagen, Elizabeth O.

2011-08-01

Announcement of discovery of Nova Lupi 2011 = PNV J14542000-5505030. Discovered by Nicholas Brown (Quinns Rocks, Western Australia) on 2011 Aug. 4.73 UT at unfiltered mag=10.2 (tmax 400 film). Posted on the IAU Central Bureau for Astronomical Telegrams Transient Object Confirmation Page (TOCP) as PNV J14542000-5505030. Spectra obtained by Fred Walter (SUNY Stony Brook) 2011 August 9.0132 UT with the SMARTS 1.5m RC spectrograph at Cerro Tololo and reported in ATEL #3536 confirms that the object is an Fe II nova near maximum. Initially announced in [vsnet-alert 13560] (Nicholas Brown) and in AAVSO Special Notice #247 (Arne Henden). Finder charts with sequence may be created using the AAVSO Variable Star Plotter (http://www.aavso.org/vsp). Observations should be submitted to the AAVSO International Database. See full Alert Notice for more details and observations.

Modelling the delay between pharmacokinetics and EEG effects of morphine in rats: binding kinetic versus effect compartment models.

PubMed

de Witte, Wilhelmus E A; Rottschäfer, Vivi; Danhof, Meindert; van der Graaf, Piet H; Peletier, Lambertus A; de Lange, Elizabeth C M

2018-05-18

Drug-target binding kinetics (as determined by association and dissociation rate constants, k on and k off ) can be an important determinant of the kinetics of drug action. However, the effect compartment model is used most frequently instead of a target binding model to describe hysteresis. Here we investigate when the drug-target binding model should be used in lieu of the effect compartment model. The utility of the effect compartment (EC), the target binding kinetics (TB) and the combined effect compartment-target binding kinetics (EC-TB) model were tested on either plasma (EC PL , TB PL and EC-TB PL ) or brain extracellular fluid (ECF) (EC ECF , TB ECF and EC-TB ECF ) morphine concentrations and EEG amplitude in rats. It was also analyzed when a significant shift in the time to maximal target occupancy (Tmax TO ) with increasing dose, the discriminating feature between the TB and EC model, occurs in the TB model. All TB models assumed a linear relationship between target occupancy and drug effect on the EEG amplitude. All three model types performed similarly in describing the morphine pharmacodynamics data, although the EC model provided the best statistical result. The analysis of the shift in Tmax TO (∆Tmax TO ) as a result of increasing dose revealed that ∆Tmax TO is decreasing towards zero if the k off is much smaller than the elimination rate constant or if the target concentration is larger than the initial morphine concentration. The results for the morphine PKPD modelling and the analysis of ∆Tmax TO indicate that the EC and TB models do not necessarily lead to different drug effect versus time curves for different doses if a delay between drug concentrations and drug effect (hysteresis) is described. Drawing mechanistic conclusions from successfully fitting one of these two models should therefore be avoided. Since the TB model can be informed by in vitro measurements of k on and k off , a target binding model should be considered more often for mechanistic modelling purposes.

Assessing potential changes of weather-related risk on chestnut productivity

NASA Astrophysics Data System (ADS)

Pereira, Mário; Calheiros, Tomas; Pinto, Joaquim; Caramelo, Liliana

2013-04-01

Weather conditions play an important role during different phases of the vegetative cycle of the chestnut trees and, consequently, several meteorological parameters seem to be associated chestnut productivity (Heiniger and Conedera, 1992, Cesaraccio et al., 2001, Wilczynski and Podalski, 2007, Gomes-Laranjo et al., 2008, Dinis et al., 2011, Pereira et al., 2011). Observed data from European Climate Assessment and simulated data by COSMO-CLM model for the actual (C20) and future (A1B and B1) climate scenarios were used in this study to: (i) assess the model ability to reproduce weather parameters distribution; and, (ii) to assess future changes in the distribution of meteorological parameters which play an important role in the productivity of chestnut for different future periods. Results points to statistical significant changes in the mean and in variance in the future, more prominent in temperature than in precipitation based parameters. Changes in precipitation will be more significant in Northwestern Iberian Peninsula and France in the end of the 21st century for A1B scenario conditions. As expected, more significant changes will be expected to occur during spring and summer, in the Mediterranean areas and in the later period. The number of days with Tmax<28°C will generally decrease in both scenarios, while the changes in the number of days with 24°C

Assessing bioequivalence of generic modified-release antiepileptic drugs

PubMed Central

Chang, Yi-Ting; Davit, Barbara; Gidal, Barry E.; Krauss, Gregory L.

2016-01-01

Objectives: The purpose of this study was to determine how closely generic modified-release antiepileptic drugs (MR-AEDs) resemble reference (brand) formulations by comparing peak concentrations (Cmax), total absorption (area under the curve [AUC]), time to Cmax (Tmax), intersubject variability, and food effects between generic and reference products. Methods: We tabulated Cmax and AUC data from the bioequivalence (BE) studies used to support the approvals of generic Food and Drug Administration–approved MR-AEDs. We compared differences in 90% confidence intervals of the generic/reference AUC and Cmax geometric mean ratios, and intersubject variability, Tmax and delivery profiles and food effects. Results: Forty-two MR-AED formulations were studied in 3,175 healthy participants without epilepsy in 97 BE studies. BE ratios for AUC and Cmax were similar between most generic and reference products: AUC ratios varied by >15% in 11.4% of BE studies; Cmax varied by >15% in 25.8% of studies. Tmax was more variable, with >30% difference in 13 studies (usually delayed in the fed compared to fasting BE studies). Generic and reference MR products had similar intersubject variability. Immediate-release AEDs showed less intersubject variability in AUC than did MR-AEDs. Conclusions: Most generic and reference MR-AEDs have similar AUC and Cmax values. Ratios for some products, however, are near acceptance limits and Tmax values may vary. Food effects are common with MR-AED products. High variability in pharmacokinetic values for once-a-day MR-AEDs suggests their major advantage compared to immediate-release AED formulations may be the convenience of less frequent dosing to improve adherence. PMID:27016518

Systemic levels of local anaesthetic after intra-peritoneal application--a systematic review.

PubMed

Kahokehr, A; Sammour, T; Vather, R; Taylor, M; Stapelberg, F; Hill, A G

2010-07-01

There is a lack of cohesive reports on the systemic levels of local anaesthetic after intraperitoneal application. A comprehensive systematic review with no language restriction was conducted. Eighteen suitable articles were identified. Data were compiled and presented according to local anaesthetic agent. Intraperitoneal local anaesthetic has been studied in many different procedures, including open and laparoscopic surgery. A total of 415 patients were included for analysis. There were no cases of clinical toxicity. There were 11 (2.7%) cases with a systemic level above or close to a safe threshold (as determined by the report authors) in three trials utilising intraperitoneal local anaesthetic after laparoscopic cholecystectomy. Intraperitoneal lignocaine doses varied from 100 to 1000 mg, mean Cmax ranged from 1.01 to 4.32 microg/ml and mean Tmax ranged from 15 to 40 minutes. Intraperitoneal bupivacaine doses varied from 50 to 150 mg (weight based doses also reported), mean Cmax ranged from 0.29 to 1.14 microg/ml and mean Tmax ranged from 15 to 60 minutes. Intraperitoneal ropivacaine doses varied from 100 to 300 mg, mean Cmax ranged from 0.66 to 3.76 microg/ml and mean Tmax ranged from 15 to 35 minutes. The addition of adrenaline to intraperitoneal local anaesthetic almost halves systemic levels and prolongs Tmax. Intraperitoneal local anaesthetic results in detectable systemic levels in the perioperative setting. Despite a lack of clinical toxicity, careful attention to dose is still required to prevent potential systemic toxic levels. Clinicians should also consider the addition of adrenaline to intraperitoneal local anaesthetic solutions to further add to the systemic safety profile.

[Pharmacokinetics after oral and intravenous administration of d,l-monolysine acetylsalicylate and an oral dose of acetylsalicylic acid in healthy volunteers].

PubMed

Raschka, C; Koch, H J

2001-01-01

We studied the ASA pharmacokinetics of single doses of 500 mg and 1000 mg of D,L-lysine-monoacetylsalicylate (Lys-ASA) administered both orally (Delgesic) and 500 mg parenterally (Aspisol) as well as 500 mg acetylsalicylate (ASA, Aspirin) in 13 healthy volunteers. Blood samples were taken before and at defined times up to 48 h after application of Lys-ASA and ASA. Analysis for ASA and its metabolite salicylic acid were performed by HPLC. All concentration versus time data were presented descriptively. As far as ASA was concerned, differences were assessed by means of ANOVA according to Friedman including post hoc Wilcoxon tests for each time point. Pharmacokinetic parameters were calculated based on a one-compartment model. The concentration vs. time curves after oral intake of 500 mg of ASA and Lys-ASA differed significantly (p < 0.001). Peak serum ASA concentrations (Cmax) were 6.8 mg/l for oral Lys-ASA and 2.7 mg/l for ASA per os. The corresponding tmax-values were 14.2 and 38.0 min. Absolute bioavailabilities for 500 mg doses were 75.4 and 63.4 pour cent, respectively. After intake of 100 mg and 1000 mg oral doses of Lys-ASA Cmax was 2.7 mg/l and 15.9 mg/l, tmax being 14.2 min for the 1000 mg dose. The shortest half-life was found after i.v. injection with 7.5 min. Metabolism was fast with maximum rise of salicylic acid concentration after injection of Lys-ASS. We conclude that concerning time dimension oral administration of Lys-ASA is almost equivalent to i.v. Lys-ASA and may be an alternative for i.v. administration in cases of acute heart attacks.

Pharmacokinetics of oral sitamaquine taken with or without food and safety and efficacy for treatment of visceral leishmaniais: a randomized study in Bihar, India.

PubMed

Sundar, Shyam; Sinha, Prabhat K; Dixon, Susan A; Buckley, Renata; Miller, Ann K; Mohamed, Khadeeja; Al-Banna, Mahir

2011-06-01

This randomized, open-label study of patients in India with visceral leishmaniasis (VL) investigated the effect of food on sitamaquine and desethyl-sitamaquine pharmacokinetics. Patients were randomized to receive oral sitamaquine, 2 mg/kg/day, once a day for 21 days across four cohorts (n = 41) (fasted/fed, fed/fasted, fed/fed, and fasted/fasted) over two periods (days 1-10 and 11-21), or intravenous amphotericin B (AmB), 1 mg/kg every other day for 30 days (n = 20). Mean day 21 pharmacokinetics across the four cohorts were sitamaquine, area under curve (AUC)((0-τ)) = 6,627-8,903 ng.hr/mL, AUC((0-16)) = 4,859-6,633 ng.hr/mL, maximum plasma concentration (C(max)) = 401-570 ng/mL, apparent terminal half-life (t(1/2)) = 18.3-22.8 hr, time to reach C(max) (t(max)) = 3.5-6 hr; and desethyl-sitamaquine, AUC((0-τ)) = 2,307-3,163 ng.hr/mL, C(max) = 109-154 ng/mL, t(1/2) = 23.0-27.9 hr, t(max) = 2-10 hr, with no significant food effect. On-therapy adverse events were observed for sitamaquine in 4 (10%) of 41 patients and for AmB in 17 (85%) of 20 patients. The final clinical cure (day 180) was 85% (95% confidence interval = 70.8-94.4%) for sitamaquine and 95% (95% confidence interval = 75.1-99.9) for AmB. Sitamaquine can be taken regardless of food intake, was generally well tolerated, and showed potential efficacy in patients with visceral leishmaniasis.

Relative bioavailability of ondansetron 8-mg oral tablets versus two extemporaneous 16-mg suppositories: formulation and gender differences.

PubMed

Jann, M W; ZumBrunnen, T L; Tenjarla, S N; Ward, E S; Weidler, D J

1998-01-01

To compare the relative bioavailability of two 16-mg extemporaneously prepared suppository formulations with that of an 8-mg commercially available oral tablet. Prospective, crossover bioavailability study. Inpatient clinical research center. Sixteen young, nonsmoking, healthy volunteers. Blood samples were obtained 24 and 48 hours after administration of an 8-mg oral ondansetron tablet and 16-mg suppository, respectively. Two 16-mg suppository formulations were compounded using commercially available Fattibase and Polybase. Ondansetron was well absorbed by both routes of administration. The following pharmacokinetic parameters (mean+/-SEM) were obtained for the 8-mg tablet, 16-mg Fattibase suppository, and 16-mg Polybase suppository, respectively: area under the curve (AUC) in men 154.2+/-21.77, 253.4+/-72.3, 304.8+/-62.2 ng x hr/ml; AUC in women 353.6+/-32.7, 561.6+/-103.6, and 768.7+/-117.9 ng x hr/ml; maximum concentration (Cmax) in men 45.5+/-7.0, 40.6+/-10.4, and 51.2+/-6.7 ng/ml; Cmax in women 51.4+/-.8, 47.1+/-3.9, and 82.9+/-6.6 ng/ml. Times to Cmax (Tmax; mean+/-SEM) for men were 1.5+/-0.3, 4.4+/-0.5, and 2.9+/-0.3 hours; Tmax for women were 1.8+/-0.3, 4.1+/-0.4, and 4.4+/-0.6 hours for the three formulations, respectively. Women had a consistently higher AUC for all three formulations than men (p<0.05). With the exception of the 16-mg Polybase formulation in women, the two suppositories closely approximated the pharmacokinetics of the 8-mg oral tablet. These results suggest that gender may be a significant factor in ondansetron's disposition.

Tangential Flow Ultrafiltration Allows Purification and Concentration of Lauric Acid-/Albumin-Coated Particles for Improved Magnetic Treatment.

PubMed

Zaloga, Jan; Stapf, Marcus; Nowak, Johannes; Pöttler, Marina; Friedrich, Ralf P; Tietze, Rainer; Lyer, Stefan; Lee, Geoffrey; Odenbach, Stefan; Hilger, Ingrid; Alexiou, Christoph

2015-08-14

Superparamagnetic iron oxide nanoparticles (SPIONs) are frequently used for drug targeting, hyperthermia and other biomedical purposes. Recently, we have reported the synthesis of lauric acid-/albumin-coated iron oxide nanoparticles SEON(LA-BSA), which were synthesized using excess albumin. For optimization of magnetic treatment applications, SPION suspensions need to be purified of excess surfactant and concentrated. Conventional methods for the purification and concentration of such ferrofluids often involve high shear stress and low purification rates for macromolecules, like albumin. In this work, removal of albumin by low shear stress tangential ultrafiltration and its influence on SEON(LA-BSA) particles was studied. Hydrodynamic size, surface properties and, consequently, colloidal stability of the nanoparticles remained unchanged by filtration or concentration up to four-fold (v/v). Thereby, the saturation magnetization of the suspension can be increased from 446.5 A/m up to 1667.9 A/m. In vitro analysis revealed that cellular uptake of SEON(LA-BSA) changed only marginally. The specific absorption rate (SAR) was not greatly affected by concentration. In contrast, the maximum temperature Tmax in magnetic hyperthermia is greatly enhanced from 44.4 °C up to 64.9 °C by the concentration of the particles up to 16.9 mg/mL total iron. Taken together, tangential ultrafiltration is feasible for purifying and concentrating complex hybrid coated SPION suspensions without negatively influencing specific particle characteristics. This enhances their potential for magnetic treatment.

Pharmacodynamic and pharmacokinetic evaluation of coadministration of lacosamide and an oral contraceptive (levonorgestrel plus ethinylestradiol) in healthy female volunteers.

PubMed

Cawello, Willi; Rosenkranz, Bernd; Schmid, Bernhard; Wierich, Werner

2013-03-01

To determine whether the antiepileptic drug lacosamide affects the pharmacokinetics or pharmacodynamics of a combined oral contraceptive (OC; ethinylestradiol 0.03 mg plus levonorgestrel 0.15 mg). This was an open-label trial in healthy female volunteers. Eligible women entered cycle 1 of the trial on the first day of menstruation. Cycle 1 was a medication-free, run-in phase of approximately 28 days to confirm that normal ovulation occurred. Volunteers with confirmed ovulation entered the subsequent cycle and started taking OCs. After establishing ovulation suppression (defined as progesterone serum concentration <5.1 nm on day 21 of the menstrual cycle) in volunteers taking the OCs in cycle 2, lacosamide 400 mg/day was administered concomitantly in the subsequent cycle (cycle 3). The pharmacokinetic parameters of area under the concentration-time curve (AUC), maximum steady-state plasma drug concentration (Cmax ), and time to maximum concentration (tmax ) were measured for the OC components and lacosamide. A total of 37 volunteers completed cycle 1, and 32 completed cycle 2. In each of the 31 volunteers who completed the trial (through cycle 3), pharmacodynamic assessment showed progesterone serum concentration was <5.1 nm on day 21 of cycle 2, when the OC was administered alone, and on day 21 of cycle 3, when lacosamide was administered concomitantly. The AUC of ethinylestradiol alone versus together with lacosamide was 1,067 ± 404 versus 1,173 ± 330 pg h/ml. Corresponding values of Cmax were 116.9 ± 48.8 versus 135.7 ± 28.6 pg/ml. For levonorgestrel, the AUC alone was 74.2 ± 21.4 versus 80.9 ± 18.5 ng h/ml with lacosamide. Corresponding values of Cmax were 6.7 ± 1.9 versus 7.4 ± 1.5 ng/ml. The AUC and Cmax point estimates and almost all 90% confidence intervals (except for Cmax of ethinylestradiol) for ethinylestradiol and levonorgestrel (with and without lacosamide) were within the conventional bioequivalence range, and no relevant changes in tmax were observed for ethinylestradiol (1.5 ± 0.6 h alone vs. 1.4 ± 0.7 h with lacosamide) or for levonorgestrel (1.5 ± 1.0 h alone vs. 1.1 ± 0.6 h with lacosamide). Lacosamide pharmacokinetics were consistent with those observed in previous studies of lacosamide alone, with values for AUC of 113.5 ± 20.7 μg h/ml, Cmax of 13.8 ± 2.2 μg/ml, and tmax of 1.1 ± 0.4 h. Lacosamide and an OC containing ethinylestradiol and levonorgestrel have low potential for drug-drug interaction; therefore, coadministration of the two drugs is unlikely to result in contraceptive failure or loss of seizure control. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

[Application of three heat pulse technique-based methods to determine the stem sap flow].

PubMed

Wang, Sheng; Fan, Jun

2015-08-01

It is of critical importance to acquire tree transpiration characters through sap flow methodology to understand tree water physiology, forest ecology and ecosystem water exchange. Tri-probe heat pulse sensors, which are widely utilized in soil thermal parameters and soil evaporation measurement, were applied to implement Salix matsudana sap flow density (Vs) measurements via heat-ratio method (HRM), T-Max method (T-Max) and single-probe heat pulse probe (SHPP) method, and comparative analysis was conducted with additional Grainer's thermal diffusion probes (TDP) measured results. The results showed that, it took about five weeks to reach a stable measurement stage after TPHP installation, Vs measured with three methods in the early stage after installation was 135%-220% higher than Vs in the stable measurement stage, and Vs estimated via HRM, T-Max and SHPP methods were significantly linearly correlated with Vs estimated via TDP method, with R2 of 0.93, 0.73 and 0.91, respectively, and R2 for Vs measured by SHPP and HRM reached 0.94. HRM had relatively higher precision in measuring low rates and reverse sap flow. SHPP method seemed to be very promising to measure sap flow for configuration simplicity and high measuring accuracy, whereas it couldn' t distinguish directions of flow. T-Max method had relatively higher error in sap flow measurement, and it couldn' t measure sap flow below 5 cm3 · cm(-2) · h(-1), thus this method could not be used alone, however it could measure thermal diffusivity for calculating sap flow when other methods were imposed. It was recommended to choose a proper method or a combination of several methods to measure stem sap flow, based on specific research purpose.

Kernel reconstruction methods for Doppler broadening - Temperature interpolation by linear combination of reference cross sections at optimally chosen temperatures

NASA Astrophysics Data System (ADS)

Ducru, Pablo; Josey, Colin; Dibert, Karia; Sobes, Vladimir; Forget, Benoit; Smith, Kord

2017-04-01

This article establishes a new family of methods to perform temperature interpolation of nuclear interactions cross sections, reaction rates, or cross sections times the energy. One of these quantities at temperature T is approximated as a linear combination of quantities at reference temperatures (Tj). The problem is formalized in a cross section independent fashion by considering the kernels of the different operators that convert cross section related quantities from a temperature T0 to a higher temperature T - namely the Doppler broadening operation. Doppler broadening interpolation of nuclear cross sections is thus here performed by reconstructing the kernel of the operation at a given temperature T by means of linear combination of kernels at reference temperatures (Tj). The choice of the L2 metric yields optimal linear interpolation coefficients in the form of the solutions of a linear algebraic system inversion. The optimization of the choice of reference temperatures (Tj) is then undertaken so as to best reconstruct, in the L∞ sense, the kernels over a given temperature range [Tmin ,Tmax ]. The performance of these kernel reconstruction methods is then assessed in light of previous temperature interpolation methods by testing them upon isotope 238U. Temperature-optimized free Doppler kernel reconstruction significantly outperforms all previous interpolation-based methods, achieving 0.1% relative error on temperature interpolation of 238U total cross section over the temperature range [ 300 K , 3000 K ] with only 9 reference temperatures.

The pharmacokinetics of intraosseous atropine in hypovolemic swine.

PubMed

Yost, Jonathan; Baldwin, Phillip; Bellenger, Sarah; Bradshaw, Freida; Causapin, Edna; Demotica, Richelle; Livingston, Michael; Lee, Cynthia; Gegel, Brian; Burgert, James; Claessens, Adam; Johnson, Don; Loughren, Michael

2015-01-01

Compare the pharmacokinetics of atropine administered via the intravenous (IV), intramuscular (IM), and intraosseous (IO) routes in a normovolemic and hypovolemic swine model. Prospective, between subjects, experimental study. Vivarium. Yorkshire-cross swine (N = 36). Atropine was administered via IV, IM, or IO routes to normovolemic and hypovolemic swine. Blood samples were drawn at regular intervals after atropine administration and analyzed for plasma atropine concentration. Pharmacokinetic parameters were obtained from modeling the plasma concentrations. Pharmacokinetic parameters, maximum concentration (Cmax) and time to maximum concentration (Tmax). The IV and IO groups in both the normovolemic and hypovolemic models reached peak plasma concentration immediately and had a very rapid distribution phase with no apparent absorption phase for the IO groups. Peak plasma concentration and time to reach peak concentration were both significantly lower for the IM groups. There was a significant increase in absorption time with IM administration in the hypovolemic model compared to the normovolemic model. The IO route is an effective method of administering atropine and is comparable to the IV route even under conditions of significant hemorrhage. Therapeutic levels of atropine may be delayed and possibly difficult to obtain via IM injection in the presence of hypovolemic shock.

A comparison of plasma levobupivacaine concentrations following transversus abdominis plane block and rectus sheath block.

PubMed

Yasumura, R; Kobayashi, Y; Ochiai, R

2016-05-01

Levobupivacaine is commonly used as the local anaesthetic of choice in peripheral nerve blocks, but its pharmacokinetics have not been fully investigated. We compared the changes in plasma concentrations of levobupivacaine following transversus abdominis plane block and rectus sheath block. Fifty woman undergoing laparoscopy were randomly allocated to receive either a transversus abdominis plane block or an rectus sheath block. In both groups, 2.5 mg.kg(-1) levobupivacaine was administered, and blood samples were obtained 15 min, 30 min, 60 min and 120 min after injection. The mean maximum plasma concentration (Cmax) and mean time to reach Cmax (Tmax) as determined by non-linear regression analysis were 1.05 μg.ml(-1) and 32.4 min in the transversus abdominis plane group and 0.95 μg.ml(-1) and 60.9 min in the rectus sheath group, respectively. The plasma concentration of levobupivacaine peaked earlier in the transversus abdominis plane group than in the rectus sheath group and the maximum plasma concentration depended on the dose administered but not the procedure. © 2016 The Association of Anaesthetists of Great Britain and Ireland.

PHARMACOKINETIC PROPERTIES OF A SINGLE ADMINISTRATION OF ORAL GABAPENTIN IN THE GREAT HORNED OWL (BUBO VIRGINIANUS).

PubMed

Yaw, Taylor J; Zaffarano, Bianca A; Gall, Andrew; Olds, June E; Wulf, Larry; Papastavros, Efthimia; Coetzee, Johann F

2015-09-01

Gabapentin (1-[aminomethyl] cyclohexane acetic acid) is a γ-aminobutyric acid analogue that has been shown to be efficacious for neuropathic pain control in humans. Plasma gabapentin concentrations >2 μg/ml are considered effective in treating epilepsy in humans and are suggested to provide analgesia for neuropathic pain. This study investigated the pharmacokinetics of a single oral dose of gabapentin suspension (11 mg/kg) in great horned owls ( Bubo virginianus ). Plasma gabapentin concentrations were determined in six healthy birds for 48 hr using high-performance liquid chromatography with mass spectrometric detection. Plasma gabapentin concentrations were estimated by noncompartmental pharmacokinetic analysis. The harmonic mean (±SD) maximum concentration (Cmax), time to maximum concentration (Tmax), and elimination half-life (tv2λZ) for gabapentin (11 mg/kg) were 6.17±0.83 μg/ml, 51.43±5.66 min, and 264.60±69.35 min, respectively. In this study, plasma gabapentin concentrations were maintained above 2 μg/ml for 528 min (8.8 hr), suggesting that gabapentin administered orally every 8 hr may be appropriate in great horned owls.

Generalized Arcsine Laws for Fractional Brownian Motion

NASA Astrophysics Data System (ADS)

Sadhu, Tridib; Delorme, Mathieu; Wiese, Kay Jörg

2018-01-01

The three arcsine laws for Brownian motion are a cornerstone of extreme-value statistics. For a Brownian Bt starting from the origin, and evolving during time T , one considers the following three observables: (i) the duration t+ the process is positive, (ii) the time tlast the process last visits the origin, and (iii) the time tmax when it achieves its maximum (or minimum). All three observables have the same cumulative probability distribution expressed as an arcsine function, thus the name arcsine laws. We show how these laws change for fractional Brownian motion Xt, a non-Markovian Gaussian process indexed by the Hurst exponent H . It generalizes standard Brownian motion (i.e., H =1/2 ). We obtain the three probabilities using a perturbative expansion in ɛ =H -1/2 . While all three probabilities are different, this distinction can only be made at second order in ɛ . Our results are confirmed to high precision by extensive numerical simulations.

Scattering attenuation profile of the Moon: Implications for shallow moonquakes and the structure of the megaregolith

NASA Astrophysics Data System (ADS)

Gillet, K.; Margerin, L.; Calvet, M.; Monnereau, M.

2017-01-01

We report measurements of the attenuation of short period seismic waves in the Moon based on the quantitative analysis of envelope records of lunar quakes. Our dataset consists of waveforms corresponding to 62 events, including artificial and natural impacts, shallow moonquakes and deep moonquakes, recorded by the four seismometers deployed during Apollo missions 12, 14, 15 and 16. To quantify attenuation and distinguish between elastic (scattering) and inelastic (absorption) mechanisms we measure the time of arrival of the maximum of energy tmax and the coda quality factor Qc . The former is controlled by both scattering and absorption, while the latter is an excellent proxy for absorption. Consistent with the strong broadening of seismogram envelopes in the Moon, we employ diffusion theory in spherical geometry to model the propagation of seismic energy in depth-dependent scattering and absorbing media. To minimize the misfit between predicted and observed tmax for deep moonquakes and impacts, we employ a genetic algorithm and explore a large number of depth-dependent attenuation models quantified by the scattering quality factor Qsc or equivalently the wave diffusivity D, and the absorption quality factor Qi . The scattering and absorption profiles that best fit the data display very strong scattering attenuation (Qsc ≤ 10) or equivalently very low wave diffusivity (D ≈ 2 km2/s) in the first 10 km of the Moon. These values correspond to the most heterogeneous regions on Earth, namely volcanic areas. Below this surficial layer, the diffusivity rises very slowly up to a depth of approximately 80 km where Qsc and D exhibit an abrupt increase of about one order of magnitude. Below 100 km depth, Qsc increases rapidly up to approximately 2000 at a depth of about 150 km, a value similar to the one found in the Earth's mantle. By contrast, the absorption quality factor on the Moon Qi ≈ 2400 is about one order or magnitude larger than on Earth. Our results suggest the existence of an approximately 100 km thick megaregolith, which is much larger than what was previously thought. The rapid decrease of scattering attenuation below this depth is compatible with crack healing through viscoelastic mechanisms. Using our best attenuation model, we invert for the depth of shallow moonquakes based on the observed variation of tmax with epicentral distance. On average, they are found to originate from a depth of about 50 km ± 20 km, which suggests that these earthquakes are caused by the failure of deep faults in the brittle part of the Moon.

Pharmacokinetics and bioequivalence of ranitidine and bismuth derived from two compound preparations

PubMed Central

Zhou, Quan; Ruan, Zou-Rong; Yuan, Hong; Jiang, Bo; Xu, Dong-Hang

2006-01-01

AIM: To evaluate the bioequivalence of ranitidine and bismuth derived from two compound preparations. METHODS: The bioavailability was measured in 20 healthy male Chinese volunteers following a single oral dose (equivalent to 200 mg of ranitidine and 220 mg of bismuth) of the test or reference products in the fasting state. Then blood samples were collected for 24 h. Plasma concentrations of ranitidine and bismuth were analyzed by high-performance liquid chromatography and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. The non-compartmental method was used for pharmacokinetic analysis. Log-transformed Cmax, AUC(0-t) and AUC(0-infinity) were tested for bioequivalence using ANOVA and Schuirmann two-one sided t-test. Tmax was analyzed by Wilcoxon’s test. RESULTS: Various pharmacokinetic parameters of ranitidine derived from the two compound preparations, including Cmax, AUC(0-t), AUC(0-infinity), Tmax and T1/2, were nearly consistent with previous observations. These parameters derived from test and reference drug were as follows: Cmax (0.67 ± 0.21 vs 0.68 ± 0.22 mg/L), AUC(0-t) (3.1 ± 0.6 vs 3.0 ± 0.7 mg/L per hour), AUC(0-infinity) (3.3 ± 0.6 vs 3.2 ± 0.8 mg/L per hour), Tmax (2.3 ± 0.9 vs 2.1 ± 0.9 h) and T1/2 (2.8 ± 0.3 vs 3.1 ± 0.4 h). In addition, double-peak absorption profiles of ranitidine were found in some Chinese volunteers. For bismuth, those parameters derived from test and reference drug were as follows: Cmax (11.80 ± 7.36 vs 11.40 ± 6.55 μg/L), AUC(0-t) (46.65 ± 16.97 vs 47.03 ± 21.49 μg/L per hour), Tmax (0.50 ± 0.20 vs 0.50 ± 0.20 h) and T1/2 (10.2 ± 2.3 vs 13.0 ± 6.9 h). Ninety percent of confidence intervals for the test/reference ratio of Cmax, AUC(0-t) and AUC(0-infinity) derived from both ranitidine and bismuth were found within the bioequivalence acceptable range of 80%-125%. No significant difference was found in Tmax derived from both ranitidine and bismuth. CONCLUSION: The two compound preparations are bioequivalent and may be prescribed interchangeably. PMID:16718762

Effects of Intraosseous Tibial vs. Intravenous Vasopressin in a Hypovolemic Cardiac Arrest Model

PubMed Central

Fulkerson, Justin; Lowe, Robert; Anderson, Tristan; Moore, Heather; Craig, William; Johnson, Don

2016-01-01

Introduction This study compared the effects of vasopressin via tibial intraosseous (IO) and intravenous (IV) routes on maximum plasma concentration (Cmax), the time to maximum concentration (Tmax), return of spontaneous circulation (ROSC), and time to ROSC in a hypovolemic cardiac arrest model. Methods This study was a randomized prospective, between-subjects experimental design. A computer program randomly assigned 28 Yorkshire swine to one of four groups: IV (n=7), IO tibia (n=7), cardiopulmonary resuscitation (CPR) + defibrillation (n=7), and a control group that received just CPR (n=7). Ventricular fibrillation was induced, and subjects remained in arrest for two minutes. CPR was initiated and 40 units of vasopressin were administered via IO or IV routes. Blood samples were collected at 0.5, 1, 1.5, 2, 2.5, 3, and 4 minutes. CPR and defibrillation were initiated for 20 minutes or until ROSC was achieved. We measured vasopressin concentrations using high-performance liquid chromatography. Results There was no significant difference between the IO and IV groups relative to achieving ROSC (p=1.0) but a significant difference between the IV compared to the CPR+ defibrillation group (p=0.031) and IV compared to the CPR-only group (p=0.001). There was a significant difference between the IO group compared to the CPR+ defibrillation group (p=0.031) and IO compared to the CPR-only group (p=0.001). There was no significant difference between the CPR + defibrillation group and the CPR group (p=0.127). There was no significant difference in Cmax between the IO and IV groups (p=0.079). The mean ± standard deviation of Cmax of the IO group was 58,709±25, 463pg/mL compared to the IV group, which was 106,198±62, 135pg/mL. There was no significant difference in mean Tmax between the groups (p=0.084). There were no significant differences in odds of ROSC between the tibial IO and IV groups. Conclusion Prompt access to the vascular system using the IO route can circumvent the interruption in treatment observed with attempting conventional IV access. The IO route is an effective modality for the treatment of hypovolemic cardiac arrest and may be considered first line for rapid vascular access. PMID:26973756

Effects of Intraosseous Tibial vs. Intravenous Vasopressin in a Hypovolemic Cardiac Arrest Model.

PubMed

Fulkerson, Justin; Lowe, Robert; Anderson, Tristan; Moore, Heather; Craig, William; Johnson, Don

2016-03-01

This study compared the effects of vasopressin via tibial intraosseous (IO) and intravenous (IV) routes on maximum plasma concentration (Cmax), the time to maximum concentration (Tmax), return of spontaneous circulation (ROSC), and time to ROSC in a hypovolemic cardiac arrest model. This study was a randomized prospective, between-subjects experimental design. A computer program randomly assigned 28 Yorkshire swine to one of four groups: IV (n=7), IO tibia (n=7), cardiopulmonary resuscitation (CPR) + defibrillation (n=7), and a control group that received just CPR (n=7). Ventricular fibrillation was induced, and subjects remained in arrest for two minutes. CPR was initiated and 40 units of vasopressin were administered via IO or IV routes. Blood samples were collected at 0.5, 1, 1.5, 2, 2.5, 3, and 4 minutes. CPR and defibrillation were initiated for 20 minutes or until ROSC was achieved. We measured vasopressin concentrations using high-performance liquid chromatography. There was no significant difference between the IO and IV groups relative to achieving ROSC (p=1.0) but a significant difference between the IV compared to the CPR+ defibrillation group (p=0.031) and IV compared to the CPR-only group (p=0.001). There was a significant difference between the IO group compared to the CPR+ defibrillation group (p=0.031) and IO compared to the CPR-only group (p=0.001). There was no significant difference between the CPR + defibrillation group and the CPR group (p=0.127). There was no significant difference in Cmax between the IO and IV groups (p=0.079). The mean ± standard deviation of Cmax of the IO group was 58,709±25, 463 pg/mL compared to the IV group, which was 106,198±62, 135 pg/mL. There was no significant difference in mean Tmax between the groups (p=0.084). There were no significant differences in odds of ROSC between the tibial IO and IV groups. Prompt access to the vascular system using the IO route can circumvent the interruption in treatment observed with attempting conventional IV access. The IO route is an effective modality for the treatment of hypovolemic cardiac arrest and may be considered first line for rapid vascular access.

The comparison of humeral intraosseous and intravenous administration of vasopressin on return of spontaneous circulation and pharmacokinetics in a hypovolemic cardiac arrest swine model.

PubMed

Wimmer, Mark H; Heffner, Kenneth; Smithers, Michael; Culley, Richard; Coyner, Jennifer; Loughren, Michael; Johnson, Don

2016-01-01

The American Heart Association (AHA) recommends intravenous (IV) or intraosseous (IO) vasopressin in Advanced Cardiac Life Support (ACLS). Obtaining IV access in hypovolemic cardiac arrest patients can be difficult, and IO access is often obtained in these life threatening situations. No studies have been conducted to determine the effects of humeral IO (HIO) access with vasopressin in the return of spontaneous circulation (ROSC). Our study compared the kinetics of vasopressin and ROSC with HIO with IV access in the hypovolemic swine model. Twenty-two Yorkshire swine were divided into three groups: HIO (n = 7), IV (n = 8), and a control group (n = 7). The IV and HIO group received vasopressin and cardiopulmonary resuscitation (CPR), while the control group received only CPR. All subjects were exsanguinated 31 percent of their blood volume, placed in cardiac arrest, and resuscitated per ACLS. Subjects that achieved ROSC were then monitored for 20 minutes. Blood samples (10 mL) collected at 0.5, 1, 1.5, 2, 2.5, 3, and 4 minutes after vasopressin injection and analyzed for maximum concentration (Cmax) and time to maximum concentration (Tmax). Data were analyzed using a multivariate analysis of variance (MANOVA) and a Fisher's Exact Test. ROSC was achieved in every subject that received vasopressin via the HIO route. Data analysis using a MANOVA pairwise comparison revealed no difference between mean Cmax (p = 0.601) and Tmax (p = 0.771) of vasopressin administered IV versus HIO routes. Analysis of the mean serum concentrations at time intervals using a repeated measures analysis of variance found no difference (p > 0.05). A Fisher's Exact Test revealed no difference in rate of ROSC between HIO and IV groups (p > 0.05). Odds ratio determined that there was a 33 times higher chance of survival among HIO subjects versus control (CPR and Defibrillation; p = 0.03) and no difference in the survivability of the HIO or IV groups (p = 0.52). The data from this study strongly suggest that there is no significant difference in ROSC, time to ROSC, hemodynamics, or pharmacokinetics between HIO vasopressin and IV vasopressin. This research reinforces current AHA guidelines recommending the use of HIO route early over delaying care awaiting IV access.

Single-Dose Pharmacokinetics and Safety of Abacavir (1592U89), Zidovudine, and Lamivudine Administered Alone and in Combination in Adults with Human Immunodeficiency Virus Infection

PubMed Central

Wang, Laurene H.; Chittick, Gregory E.; McDowell, James A.

1999-01-01

Abacavir (1592U89), a nucleoside reverse transcriptase inhibitor with in vitro activity against human immunodeficiency virus type-1 (HIV-1), has been evaluated for efficacy and safety in combination regimens with other nucleoside analogs, including zidovudine (ZDV) and lamivudine (3TC). To evaluate the potential pharmacokinetic interactions between these agents, 15 HIV-1-infected adults with a median CD4+ cell count of 347 cells/mm3 (range, 238 to 570 cells/mm3) were enrolled in a randomized, seven-period crossover study. The pharmacokinetics and safety of single doses of abacavir (600 mg), ZDV (300 mg), and 3TC (150 mg) were evaluated when each drug was given alone or when any two or three drugs were given concurrently. The concentrations of all drugs in plasma and the concentrations of ZDV and its 5′-glucuronide metabolite, GZDV, in urine were measured for up to 24 h postdosing, and pharmacokinetic parameter values were calculated by noncompartmental methods. The maximum drug concentration (Cmax), the area under the concentration-time curve from time zero to infinity (AUC0–∞), time to Cmax (Tmax), and apparent elimination half-life (t1/2) of abacavir in plasma were unaffected by coadministration with ZDV and/or 3TC. Coadministration of abacavir with ZDV (with or without 3TC) decreased the mean Cmax of ZDV by approximately 20% (from 1.5 to 1.2 μg/ml), delayed the median Tmax for ZDV by 0.5 h, increased the mean AUC0–∞ for GZDV by up to 40% (from 11.8 to 16.5 μg · h/ml), and delayed the median Tmax for GZDV by approximately 0.5 h. Coadministration of abacavir with 3TC (with or without ZDV) decreased the mean AUC0–∞ for 3TC by approximately 15% (from 5.1 to 4.3 μg · h/ml), decreased the mean Cmax by approximately 35% (from 1.4 to 0.9 μg/ml), and delayed the median Tmax by approximately 1 h. While these changes were statistically significant, they are similar to the effect of food intake (for ZDV) or affect an inactive metabolite (for GZDV) or are relatively minor (for 3TC) and are therefore not considered to be clinically significant. No significant differences were found in the urinary recoveries of ZDV or GZDV when ZDV was coadministered with abacavir. There was no pharmacokinetic interaction between ZDV and 3TC. Mild to moderate headache, nausea, lymphadenopathy, hematuria, musculoskeletal chest pain, neck stiffness, and fever were the most common adverse events reported by those who received abacavir. Coadministration of ZDV or 3TC with abacavir did not alter this adverse event profile. The three-drug regimen was primarily associated with gastrointestinal events. In conclusion, no clinically significant pharmacokinetic interactions occurred between abacavir, ZDV, and 3TC in HIV-1-infected adults. Coadministration of abacavir with ZDV or 3TC produced mild changes in the absorption and possibly the urinary excretion characteristics of ZDV-GZDV and 3TC that were not considered to be clinically significant. Coadministration of abacavir with ZDV and/or 3TC was generally well tolerated and did not produce unexpected adverse events. PMID:10390227

Influence of stem temperature changes on heat pulse sap flux density measurements.

PubMed

Vandegehuchte, Maurits W; Burgess, Stephen S O; Downey, Alec; Steppe, Kathy

2015-04-01

While natural spatial temperature gradients between measurement needles have been thoroughly investigated for continuous heat-based sap flow methods, little attention has been given to how natural changes in stem temperature impact heat pulse-based methods through temporal rather than spatial effects. By modelling the theoretical equation for both an ideal instantaneous pulse and a step pulse and applying a finite element model which included actual needle dimensions and wound effects, the influence of a varying stem temperature on heat pulse-based methods was investigated. It was shown that the heat ratio (HR) method was influenced, while for the compensation heat pulse and Tmax methods changes in stem temperatures of up to 0.002 °C s(-1) did not lead to significantly different results. For the HR method, rising stem temperatures during measurements led to lower heat pulse velocity values, while decreasing stem temperatures led to both higher and lower heat pulse velocities, and to imaginary results for high flows. These errors of up to 40% can easily be prevented by including a temperature correction in the data analysis procedure, calculating the slope of the natural temperature change based on the measured temperatures before application of the heat pulse. Results of a greenhouse and outdoor experiment on Pinus pinea L. show the influence of this correction on low and average sap flux densities. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Brain delivery of buspirone hydrochloride chitosan nanoparticles for the treatment of general anxiety disorder.

PubMed

Bari, Naimat Kalim; Fazil, Mohammad; Hassan, Md Quamrul; Haider, Md Rafi; Gaba, Bharti; Narang, Jasjeet K; Baboota, Sanjula; Ali, Javed

2015-11-01

The present work discusses the preparation, characterization and in vivo evaluation of thiolated chitosan nanoparticles (TCS-NPs) of buspirone hydrochloride (BUH) for brain delivery through intranasal route. TCS NPs were prepared by ionic gelation method and characterized for various parameters. The NPs formed were having particle size of 226.7±2.52nm with PDI 0.483±0.031. Drug entrapment efficiency (EE) and loading capacity (LC) were found to be 81.13±2.8 and 49.67±5.5%. The cumulative percentage drug permeation through nasal mucosa was 76.21%. Bioadhesion study carried out on porcine mucin and showed a bioadhesion efficiency of 90.218±0.134%. Nose-to-brain delivery of placebo NPs was investigated by confocal laser scanning microscopy (CLSM) technique using rhodamine-123 as a marker. The brain concentration achieved after intranasal administration of TCS-NPs was 797.46±35.76ng/ml with tmax 120min which was significantly higher than achieved after intravenous administration on BUH solution 384.15±13.42ng/ml and tmax of 120min and intranasal administration of BUH solution 417.77±19.24ng/ml and tmax 60min. Copyright © 2015 Elsevier B.V. All rights reserved.

Inhibitory activity of aspirin on von Willebrand factor-induced platelet aggregation.

PubMed

Homoncik, M; Jilma, B; Eichelberger, B; Panzer, S

2000-09-01

The effect of aspirin (ASA) on vWF induced platelet - platelet interaction is unknown. We therefore tested the response of platelets to von Willebrand factor (vWF) coated beads induced platelet aggregation before and after i.v. and oral ASA. 1000 mg ASA was infused to 10 healthy individuals and after a wash-out period 7 volunteers received 100 mg ASA orally over a period of 11 days. Prior to ASA and in regular intervals thereafter we tested the reactivity to vWF-coated beads to assess platelet adhesion/aggregation and the fade-out time of ASA effects on platelets. Considerable interindividual variability in response to vWF-coated beads was observed, both before ASA and after treatment with ASA. The maximal response to vWF-coated beads (Tmax), the time lag, and the slope of the curve were significantly affected by i.v. ASA, whereas 100 mg of ASA had only inconstant effect on Tmax and slope. The absolute reduction of Tmax after ASA depended on the pre-ASA level, while the percentage of the reduction was similar in all individuals. Thus, platelet aggregation induced by vWF-coated beads is impaired by ASA. Furthermore, our data indicate a large interindividual variability of the response to ASA shortly after treatment induction, which becomes more constant after prolonged treatment.

Large Electrocaloric Effect in Lead-Free (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 Ceramics Prepared via Citrate Route

PubMed Central

Shi, Jing; Zhu, Rongfeng; Liu, Xing; Yuan, Ningyi; Ding, Jianning; Luo, Haosu

2017-01-01

The 1 wt % Li-doped (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT-Li) ceramics prepared by the citrate method exhibit improved phase purity, densification and electrical properties, which provide prospective possibility to develop high-performance electrocaloric materials. The electrocaloric effect was evaluated by phenomenological method, and the BCZT-Li ceramics present large electrocaloric temperature change ∆T, especially large electrocaloric responsibility ξ = ∆Tmax/∆Emax, which can be comparable to the largest values reported in the lead-free piezoelectric ceramics. The excellent electrocaloric effect is considered as correlating with the coexistence of polymorphic ferroelectric phases, which are detected by the Raman spectroscopy. The large ξ value accompanied by decreased Curie temperature (around 73 °C) of the BCZT-Li ceramics prepared by the citrate method presents potential applications as the next-generation solid-state cooling devices. PMID:28927004

Sources of variability of evapotranspiration in California

USGS Publications Warehouse

Hidalgo, H.G.; Cayan, D.R.; Dettinger, M.D.

2005-01-01

The variability (1990-2002) of potential evapotranspiration estimates (ETo) and related meteorological variables from a set of stations from the California Irrigation Management System (CIMIS) is studied. Data from the National Climatic Data Center (NCDC) and from the Department of Energy from 1950 to 2001 were used to validate the results. The objective is to determine the characteristics of climatological ETo and to identify factors controlling its variability (including associated atmospheric circulations). Daily ETo anomalies are strongly correlated with net radiation (Rn) anomalies, relative humidity (RH), and cloud cover, and less with average daily temperature (Tavg). The highest intraseasonal variability of ETo daily anomalies occurs during the spring, mainly caused by anomalies below the high ETo seasonal values during cloudy days. A characteristic circulation pattern is associated with anomalies of ETo and its driving meteorological inputs, Rn, RH, and Tavg, at daily to seasonal time scales. This circulation pattern is dominated by 700-hPa geopotential height (Z700) anomalies over a region off the west coast of North America, approximately between 32?? and 44?? latitude, referred to as the California Pressure Anomaly (CPA). High cloudiness and lower than normal ETo are associated with the lowheight (pressure) phase of the CPA pattern. Higher than normal ETo anomalies are associated with clear skies maintained through anomalously high Z700 anomalies offshore of the North American coast. Spring CPA, cloudiness, maximum temperature (Tmax), pan evaporation (Epan), and ETo conditions have not trended significantly or consistently during the second half of the twentieth century in California. Because it is not known how cloud cover and humidity will respond to climate change, the response of ETo in California to increased greenhouse-gas concentrations is essentially unknown; however, to retain the levels of ETo in the current climate, a decline of Rn by about 6% would be required to compensate for a warming of +3??C. ?? 2005 American Meteorological Society.

Thermal therapy of pancreatic tumors using endoluminal ultrasound: parametric and patient-specific modeling

PubMed Central

Adams, Matthew S.; Scott, Serena J.; Salgaonkar, Vasant A.; Sommer, Graham; Diederich, Chris J.

2016-01-01

Purpose To investigate endoluminal ultrasound applicator configurations for volumetric thermal ablation and hyperthermia of pancreatic tumors using 3D acoustic and biothermal finite element models. Materials and Methods Parametric studies compared endoluminal heating performance for varying applicator transducer configurations (planar, curvilinear-focused, or radial-diverging), frequencies (1–5 MHz), and anatomical conditions. Patient-specific pancreatic head and body tumor models were used to evaluate feasibility of generating hyperthermia and thermal ablation using an applicator positioned in the duodenal or stomach lumen. Temperature and thermal dose were calculated to define ablation (>240 EM43°C) and moderate hyperthermia (40–45 °C) boundaries, and to assess sparing of sensitive tissues. Proportional-integral control was incorporated to regulate maximum temperature to 70–80 °C for ablation and 45 °C for hyperthermia in target regions. Results Parametric studies indicated that 1–3 MHz planar transducers are most suitable for volumetric ablation, producing 5–8 cm3 lesion volumes for a stationary 5 minute sonication. Curvilinear-focused geometries produce more localized ablation to 20–45 mm depth from the GI tract and enhance thermal sparing (Tmax<42 °C) of the luminal wall. Patient anatomy simulations show feasibility in ablating 60.1–92.9% of head/body tumor volumes (4.3–37.2 cm3) with dose <15 EM43°C in the luminal wall for 18–48 min treatment durations, using 1–3 applicator placements in GI lumen. For hyperthermia, planar and radial-diverging transducers could maintain up to 8 cm3 and 15 cm3 of tissue, respectively, between 40–45 °C for a single applicator placement. Conclusions Modeling studies indicate the feasibility of endoluminal ultrasound for volumetric thermal ablation or hyperthermia treatment of pancreatic tumor tissue. PMID:27097663

Evaluating the applicability of using daily forecasts from seasonal prediction systems (SPSs) for agriculture: a case study of Nepal's Terai with the NCEP CFSv2

NASA Astrophysics Data System (ADS)

Jha, Prakash K.; Athanasiadis, Panos; Gualdi, Silvio; Trabucco, Antonio; Mereu, Valentina; Shelia, Vakhtang; Hoogenboom, Gerrit

2018-03-01

Ensemble forecasts from dynamic seasonal prediction systems (SPSs) have the potential to improve decision-making for crop management to help cope with interannual weather variability. Because the reliability of crop yield predictions based on seasonal weather forecasts depends on the quality of the forecasts, it is essential to evaluate forecasts prior to agricultural applications. This study analyses the potential of Climate Forecast System version 2 (CFSv2) in predicting the Indian summer monsoon (ISM) for producing meteorological variables relevant to crop modeling. The focus area was Nepal's Terai region, and the local hindcasts were compared with weather station and reanalysis data. The results showed that the CFSv2 model accurately predicts monthly anomalies of daily maximum and minimum air temperature (Tmax and Tmin) as well as incoming total surface solar radiation (Srad). However, the daily climatologies of the respective CFSv2 hindcasts exhibit significant systematic biases compared to weather station data. The CFSv2 is less capable of predicting monthly precipitation anomalies and simulating the respective intra-seasonal variability over the growing season. Nevertheless, the observed daily climatologies of precipitation fall within the ensemble spread of the respective daily climatologies of CFSv2 hindcasts. These limitations in the CFSv2 seasonal forecasts, primarily in precipitation, restrict the potential application for predicting the interannual variability of crop yield associated with weather variability. Despite these limitations, ensemble averaging of the simulated yield using all CFSv2 members after applying bias correction may lead to satisfactory yield predictions.

Relationship between icotinib hydrochloride exposure and clinical outcome in Chinese patients with advanced non-small cell lung cancer.

PubMed

Ni, Jun; Liu, Dong-Yang; Hu, Bei; Li, Chen; Jiang, Ji; Wang, Han-Ping; Zhang, Li

2015-09-01

The current study was conducted to explore the relationship between icotinib hydrochloride exposure and therapeutic effects in Chinese patients with advanced non-small cell lung cancer (NSCLC) who were treated with icotinib hydrochloride. A total of 30 patients with NSCLC who were treated with icotinib hydrochloride were chosen from a single-center, open-label, phase 1 dose escalation clinical trial. Different doses of icotinib hydrochloride were administered orally for 28 consecutive days in different groups until disease progression or unacceptable toxicities occurred. Blood samples were collected during the first treatment cycle (day 1-28) for the pharmacokinetic analysis. Tumor responses were assessed according to the Response Evaluation Criteria in Solid Tumors (RECIST). The plasma concentrations of icotinib hydrochloride were assessed by liquid chromatography-mass spectrometry. Thirty patients with a median age of 56 years old (50% of whom were female) were enrolled. For single-dose treatment, the plasma pharmacokinetics demonstrated a median time to maximum concentration of 0.5 to 4 hours and a mean terminal elimination half-life of 6.21±3.44 hours at the 150-mg dose and 10.1±12.18 hours at the 200-mg dose. For multiple-dose treatment, the last measurable concentration (Clast ) was 708±368.67 ng/mL at the 150-mg every 12 hours, 782.73±618.18 ng/mL at the 200-mg every 12 hours, and 1162±658.44 ng/mL at the 125-mg every 8 hours; the under the concentration curve from time 0 to Clast was 14.5±2.43 hour*mg/mL, 13.2±2.5 hour*mg/mL, and 12.19±2.47 hour*mg/mL, respectively. At the dose of 150 mg every 12 hours, 1 patient with an epidermal growth factor receptor (EGFR) exon 19 deletion achieved a complete response for 10 months; another patient who carried the EGFR exon 19 deletion achieved stable disease for 6 months. Univariate analysis demonstrated that the time to maximum plasma concentration (Tmax ) after a single dose of icotinib hydrochloride was significantly correlated with the overall survival (OS) (Spearman correlation coefficient, 0.441; P = .012). The disease control rate was correlated with Tmax after a single dose (Spearman correlation coefficient, 0.518; P = .011). Multivariate analysis demonstrated that the area under the concentration-time curve from 0 to last determination time and the area under the curve from 0 to infinite time after a single dose of icotinib hydrochloride were correlated with OS (P = .037 and .042, respectively). The Clast was found to affect progression-free survival (P = .016). Stratification of these patients according to smoking status indicated significant correlation between OS and the area under the concentration-time curve from 0 to last determination time (Spearman correlation coefficient, -0.709; P = .015). Patients with a longer Tmax and higher exposure might experience longer OS and a higher disease control rate. In addition, the increased Clast might prolong the progressive-free survival of patients. However, the relationships between EGFR mutation, pharmacokinetics, and clinical outcomes require further research. © 2015 American Cancer Society.

Responses of catecholestrogen metabolism to acute graded exercise in normal menstruating women before and after training.

PubMed

De Crée, C; Ball, P; Seidlitz, B; Van Kranenburg, G; Geurten, P; Keizer, H A

1997-10-01

It has been hypothesized that exercise-related hypo-estrogenemia occurs as a consequence of increased competition of catecholestrogens (CE) for catechol-O-methyltransferase (COMT). This may result in higher norepinephrine (NE) concentrations, which could interfere with normal gonadotropin pulsatility. The present study investigates the effects of training on CE responses to acute exercise stress. Nine untrained eumenorrheic women (mean percentage of body fat +/-SD: 24.8 +/- 3.1%) volunteered for an intensive 5-day training program. Resting, submaximal, and maximal (tmax) exercise plasma CE, estrogen, and catecholamine responses were determined pre- and post training in both the follicular (FPh) and luteal phase (LPh). Acute exercise stress increased total primary estrogens (E) but had little effect on total 2-hydroxyestrogens (2-OHE) and 2-hydroxyestrogen-monomethylethers (2-MeOE) (= O-methylated CE after competition for catechol-O-methyltransferase). This pattern was not significantly changed by training. However, posttraining LPh mean (+/-SE) plasma E, 2-OHE, and 2-MeOE concentrations were significantly lower (P < 0.05) at each exercise intensity (for 2-OHE: 332 +/- 47 vs. 422 +/- 57 pg/mL at tmax; for 2-MeOE: 317 +/- 26 vs. 354 +/- 34 pg/mL at tmax). Training produced opposite effects on 2-OHE:E ratios (an estimation of CE formation) during acute exercise in the FPh (reduction) and LPh (increase). The 2-MeOE:2-OHE ratio (an estimation of CE activity) showed significantly higher values at tmax in both menstrual phases after training (FPh: +11%; LPh: +23%; P < 0.05). After training, NE values were significantly higher (P < 0.05). The major findings of this study were that: training lowers absolute concentrations of plasma estrogens and CE; the acute exercise challenge altered plasma estrogens but had little effect on CE; estimation of the formation and activity of CE suggests that formation and O-methylation of CE proportionately increases. These findings may be of importance for NE-mediated effects on gonadotropin release.

A pharmacokinetic study of two modified-release methylphenidate formulations under different food conditions in healthy volunteers.

PubMed

Haessler, F; Tracik, F; Dietrich, H; Stammer, H; Klatt, J

2008-09-01

Primary objective was to investigate bioequivalence of Ritalin LA(R); 40 mg compared to Medikinet retard 40 mg in healthy male volunteers under fasted and fed conditions. Secondary objectives included assessment of tolerability and determination of further pharmacokinetic parameters. The difference between the kinetic profiles of Ritalin LA(R) and Medikinet retard with respect to breakfast intake was additionally explored. 28 subjects were randomized in this open-label, four-treatment, cross-over-design study. Pharmacokinetic evaluations included AUC(0-inf), Cmax, tmax, elimination half life (t1/2) and mean residence time MRT(0-inf)). The relative bioavailability of Ritalin LA(R) and Medikinet retard and the food effect were assessed using a 90% confidence interval (CI) based on the lower and upper endpoints of the CI for the ratios of the geometric means being within the 80 - 125% equivalence criterion. 25 volunteers completed all treatment arms. Frequency of adverse events were comparable for all treatments. Under fasted condition Ritalin LA(R) showed a consistent bimodal concentration time profile with two tmax peaks. Medikinet retard showed a steady absorption with a single tmax peak. The point estimators for AUC(0-inf) and Cmax were found to be 99.7% and 85.9%, respectively. Under fed condition both Ritalin LA(R) and Medikinet retard showed a bimodal concentration time profile with two tmax peaks. The point estimators for AUC(0-inf) and Cmax were estimated as 89.8% and 68.6%, respectively. Both methylphenidate formulations were safe and well tolerated. Ritalin LA and Medikinet retard were bioequivalent in fasted state but not in fed state. Only Ritalin LA had a biphasic kinetic profile under both fasted and fed conditions. This difference in the kinetic profiles might be of clinical relevance and might offer a potential advantage of Ritalin LA.

Systematic analysis of the polyphenol metabolome using the Phenol-Explorer database.

PubMed

Rothwell, Joseph A; Urpi-Sarda, Mireia; Boto-Ordoñez, Maria; Llorach, Rafael; Farran-Codina, Andreu; Barupal, Dinesh Kumar; Neveu, Vanessa; Manach, Claudine; Andres-Lacueva, Cristina; Scalbert, Augustin

2016-01-01

The Phenol-Explorer web database details 383 polyphenol metabolites identified in human and animal biofluids from 221 publications. Here, we exploit these data to characterize and visualize the polyphenol metabolome, the set of all metabolites derived from phenolic food components. Qualitative and quantitative data on 383 polyphenol metabolites as described in 424 human and animal intervention studies were systematically analyzed. Of these metabolites, 301 were identified without prior enzymatic hydrolysis of biofluids, and included glucuronide and sulfate esters, glycosides, aglycones, and O-methyl ethers. Around one-third of these compounds are also known as food constituents and corresponded to polyphenols absorbed without further metabolism. Many ring-cleavage metabolites formed by gut microbiota were noted, mostly derived from hydroxycinnamates, flavanols, and flavonols. Median maximum plasma concentrations (C(max)) of all human metabolites were 0.09 and 0.32 μM when consumed from foods or dietary supplements, respectively. Median time to reach maximum plasma concentration in humans (T(max)) was 2.18 h. These data show the complexity of the polyphenol metabolome and the need to take into account biotransformations to understand in vivo bioactivities and the role of dietary polyphenols in health and disease. © 2015 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pharmacokinetics of multiple doses of transdermal flunixin meglumine in adult Holstein dairy cows.

PubMed

Kleinhenz, M D; Gorden, P J; Smith, J S; Schleining, J A; Kleinhenz, K E; Wulf, L L; Sidhu, P K; Rea, D; Coetzee, J F

2018-06-01

A transdermal formulation of the nonsteroidal anti-inflammatory drug, flunixin meglumine, has been approved in the United States and Canada for single-dose administration. Transdermal flunixin meglumine was administered to 10 adult Holstein cows in their second or third lactation at the label dose of 3.33 mg/kg every 24 hr for three total treatments. Plasma flunixin concentrations were determined using high-pressure liquid chromatography with mass spectroscopy (HPLC-MS). Pharmacokinetic analysis was completed on each individual animal with noncompartmental methods using computer software. The time to maximum drug concentration (Tmax) was 2.81 hr, and the maximum drug concentration was 1.08 μg/ml. The mean terminal half-life (T½) was determined to be 5.20 hr. Clearance per fraction absorbed (Cl/F) was calculated to be 0.294 L/hr kg -1 , and volume of distribution of fraction (Vz/F) absorbed was 2.20 L/kg. The mean accumulation factor was 1.10 after three doses. This indicates changes in dosing may not be required when giving multiple doses of flunixin transdermal. Further work is required to investigate the clinical efficacy of transdermal flunixin after multiple daily doses. © 2018 John Wiley & Sons Ltd.

Diagenesis of Upper Carboniferous rocks in the Ouachita foreland shelf in mid-continent USA: an overview of widespread effects of a Variscan-equivalent orogeny

USGS Publications Warehouse

Walton, A.W.; Wojcik, K.M.; Goldstein, R.H.; Barker, C.E.

1995-01-01

Diagenesis of Upper Carboniferous foreland shelf rocks in southeastern Kansas took place at temperatures as high as 100-150?? C at a depth of less than 2 km. High temperatures are the result of the long distance (hundreds of kilometers) advection of groundwater related to collisional orogeny in the Ouachita tectonic belt to the south. Orogenic activity in the Ouachita area was broadly Late Carboniferous, equivalent to the Variscan activity of Europe. Mississippi Valley-type Pb-Zn deposits and oil and gas fields in the US midcontinent and elsewhere are commonly attributed to regional groundwater flow resulting from such collisional events. This paper describes the diagenesis and thermal effects in sandstone and limestone of Upper Carboniferous siliciclastic and limestone-shale cyclothems, the purported confining layer of a supposed regional aquifer. Diagenesis took place in early, intermediate, and late stages. Many intermediate and late stage events in the sandstones have equivalents in the limestones, suggesting that the causes were regional. The sandstone paragenesis includes siderite cement (early stage), quartz overgrowths (intermediate stage), dissolution of feldspar and carbonates, followed by minor Fe calcite, pore-filling kaolinite and sub-poikilotopic Ca ankerite (late stage). The limestone paragenesis includes calcite cement (early stage); megaquartz, chalcedony, and Fe calcite spar (intermediate stage); and dissolution, Ca-Fe dolomite and kaolinite (late stage). The Rm value of vitrinite shows a regional average of 0.6-0.7%; Rock-Eval TmaX suggests a comparable degree of organic maturity. The Th of aqueous fluid inclusions in late stage Ca-Fe-Mg carbonates ranges from 90 to 160?? and Tmice indicates very saline water (>200000 ppm NaCl equivalent); ??18O suggests that the water is of basinal origin. Local warm spots have higher Rm, Tmax, and Th. The results constrain numerical models of regional fluid migration, which is widely viewed as an artesian flow from recharge areas in the Ouachita belt across the foreland basin onto the foreland shelf area. Such models must account for heating effects that extend at least 500 km from the orogenic front and affect both supposed aquifer beds and the overlying supposed confining layer. Warm spots indicate either more rapid or more prolonged flow locally. Th and Tmice data show the highest temperatures coincided with high salinity fluids. ?? 1995 Springer-Verlag.

Weather types and strokes in the Augsburg region (Southern Germany)

NASA Astrophysics Data System (ADS)

Beck, Christoph; Ertl, Michael; Giemsa, Esther; Jacobeit, Jucundus; Naumann, Markus; Seubert, Stefanie

2017-04-01

Strokes are one of the leading causes of morbidity and mortality worldwide and the main reason for longterm care dependency in Germany. Concerning the economical impact on patients and healthcare systems it is of particular importance to prevent this disease as well as to improve the outcome of the affected persons. Beside the primary well-known risk factors like hypertension, cigarette smoking, physical inactivity and others, also weather seems to have pronounced influence on the occurrence and frequency of strokes. Previous studies most often focused on effects of singular meteorological variables like ambient air temperature, air pressure or humidity. An advanced approach is to link the entire suite of daily weather elements classified to air mass- or weather types to cerebrovascular morbidity or mortality. In a joint pilot study bringing together climatologists, environmental scientists and physicians from the University of Augsburg and the clinical centre Augsburg, we analysed relationships between singular meteorological parameters as well as combined weather effects (e.g. weather types) and strokes in the urban area of Augsburg and the surrounding rural region. A total of 17.501 stroke admissions to Neurological Clinic and Clinical Neurophysiology at Klinikum Augsburg between 2006 and 2015 are classified to either "ischaemic" (16.354) or "haemorrhagic" (1.147) subtype according to etiology (based on the International Classification of Diseases - 10th Revision). Spearman correlations between daily frequencies of ischaemic and haemorrhagic strokes and singular atmospheric parameters (T, Tmin, Tmax, air pressure, humidity etc.) measured at the DWD (German weather service) meteorological station at Augsburg Muehlhausen are rather low. However, higher correlations are achieved when considering sub-samples of "homogenous weather conditions" derived from synoptic circulation classifications: e.g. within almost all of 10 types arising from a classification of central European mean sea level pressure fields into "Großwettertypes" (Beck 2000) the relationships between meteorological variables and stroke frequencies are increasing. Mainly temperature variables (Tmin, Tmax, Tmean) appear to be important particularly in winter and summer. Moreover distinct correlations of similar magnitude are obtained with other variables like wind speed or precipitation for specific weather types (e.g. westerly type). In how far these initial findings do really point to additional health impacts beyond temperature effects is subject of ongoing work.

Radon and Thoron In-air Occupational Exposure Study within Selected Wine Cellars of the Western Cape (South Africa) and Associated Annual Effective Doses.

PubMed

Botha, R; Newman, R T; Lindsay, R; Maleka, P P

2017-01-01

This is the first known study of exposure of Rn (radon) and secondarily Rn (thoron) in-air activity concentrations assessed within nine selected wine cellars in four wine districts of the Western Cape (South Africa) and the associated annual occupational effective doses. E-PERM electret ion chambers (EIC) and RAD-7 α-detectors were used to perform these measurements. The radon in-air levels ranged from 12 ± 4 Bq m to 770 ± 40 Bq m within the nine selected wine cellars. Eight of the nine wine cellars (excluding results from cellar w-6) had a median radon in-air activity concentration of 48 ± 8 Bq m. Continuous thoron in-air activity concentration levels were also measured near an internal granite wall of the wine cellar w-6 (barrel room), where peak levels of up to 1,520 ± 190 Bq m and an average of 680 ± 30 Bq m were observed. The occupational annual effective dose due to radon and decay progeny exposure in-air within the selected wine cellars ranged from 0.08 ± 0.03 mSv to 4.9 ± 0.3 mSv with a median of 0.32 ± 0.04 mSv (Tmax = 2,000 h). The annual effective dose within the wine cellar (w-6) ranged up to a maximum of 2.5 ± 0.4 mSv (Tmax = 2000 h) due to exposure to thoron and decay progeny. In general, most of the wines cellars pose negligible associated health risk to personnel due to ionizing radiation exposure from the inhalation of radon and progeny. Under certain conditions (proximity and exposure time), caution should be exercised at wine cellar w-6 because of elevated thoron in-air levels.

Novel nicotine analogues with potential anti-mycobacterial activity.

PubMed

Gandhi, Paresh T; Athmaram, Thimmasandra Narayanappa; Arunkumar, Gundaiah Ramesh

2016-04-15

Tuberculosis (TB) is the second leading lethal infectious disease in the world after acquired immuno deficiency (AIDs). We have developed a series of twenty-five novel nicotine analogues with de-addiction property and tested them for their activity against Mycobacterium tuberculosis (MTB). In an effort to increase the specificity of action and directing nicotine analogues to target MTB, four promising compounds were further optimized via molecular docking studies against the Dihydrofolate reductase of MTB. After lead optimization, one nicotine analogue [3-(5-(3fluorophenyl)nicotinoyl)-1-methylpyrrolidin-2-one] exhibited minimum inhibitory concentration of 1 μg/mL (2.86 nM) against M. tuberculosis (H37Rv strain), a human pathogenic strain of clinically significant importance. Pharmacokinetic analysis of [3-(5-(3fluorophenyl)nicotinoyl)-1methylpyrrolidin-2-one] with lowest MIC value via oral route in Wistar rats revealed that at a dosage of 5 mg/kg body weight gave a maximum serum drug concentration (Cmax) of 2.86 μg/mL, Tmax of one hour and a half-life (T1/2) of more than 24 h and Volume of distribution (Vd) of 27.36 L. Whereas the parenteral (intra venous) route showed a Cmax of 3.37 μg/mL, Tmax of 0.05 h, T1/2 of 24 h and Vd equivalent to 23.18 L. The acute oral toxicity and repeated oral toxicity studies in female Wistar rats had an LD50>2000 mg/kg body weight. Our data suggests that nicotine derivatives developed in the present study has good metabolic stability with tunable pharmacokinetics (PK) with therapeutic potential to combat MTB. However, further in vivo studies for anti-tuberculosis activity and elucidation of mode of action could result in more promising novel drug for treating MTB. To the best of our knowledge this is the first report revealing the anti-mycobacterial potential of nicotine analogue at potential therapeutic concentrations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pharmacokinetics of tilmicosin (Provitil powder and Pulmotil liquid AC) oral formulations in chickens.

PubMed

Abu-Basha, E A; Idkaidek, N M; Al-Shunnaq, A F

2007-05-01

A bioavailability and pharmacokinetics study of powder and liquid tilmicosin formulations was carried out in 18 healthy chickens according to a single-dose, two-period, two-sequence, crossover randomized design. The two formulations were Provitil and Pulmotil AC. Both drugs were administered to each chicken after an overnight fast on two treatment days separated by a 2-week washout period. A modified rapid and sensitive HPLC method was used for determination of tilmicosin concentrations in chicken plasma. Various pharmacokinetic parameters including area under plasma concentration-time curve (AUC(0-72)), maximum plasma concentration (C(max)), time to peak concentration (t(max)), elimination half-life (t(1/2beta)), elimination rate (k(el)), clearance (Cl(B)), mean residence time (MRT) and volume of distribution (V(d,area)) were determined for both formulations. The average means of AUC(0-72) for Provitil and Pulmotil AC were very close (24.24 +/- 3.86, 21.82 +/- 3.14 (microg x h)/ml, respectively), with no significant differences based on ANOVA. The relative bioavailability of Provitil as compared to Pulmotil AC was 111%. In addition, there were no significant differences in the C(max) (2.09 +/- 0.37, 2.12 +/- 0.40 microg/ml), tmax (3.99 +/- 0.84, 5.82 +/- 1.04 h), t(1/2beta) (47.4 +/- 9.32, 45.0 +/- 5.73 h), k(el) (0.021 +/- 0.0037, 0.022 +/- 0.0038 h(-1)), Cl(B) (19.73 +/- 3.73, 21.37 +/- 4.54ml/(min/kg)), MRT (71.20 +/- 12.87, 67.15 +/- 9.01 h) and V(d,area) (1024.8 +/- 87.5, 1009.8 +/- 79.5 ml/kg) between Pulmotil AC and Provitil, respectively. In conclusion, tilmicosin was rapidly absorbed and slowly eliminated after oral administration of single dose of tilmicosin aqueous and powder formulations. Provitil and Pulmotil AC can be used as interchangeable therapeutic agents.

Epinephrine in Anaphylaxis: Preclinical Study of Pharmacokinetics after Sublingual Administration of Taste-Masked Tablets for Potential Pediatric Use

PubMed Central

Rawas-Qalaji, Mutasem; Simons, Keith J.

2018-01-01

Epinephrine is a life-saving treatment in anaphylaxis. In community settings, a first-aid dose of epinephrine is injected from an auto-injector (EAI). Needle phobia highly contributes to EAI underuse, leading to fatalities—especially in children. A novel rapidly-disintegrating sublingual tablet (RDST) of epinephrine was developed in our laboratory as a potential alternative dosage form. The aim of this study was to evaluate the sublingual bioavailability of epinephrine 30 mg as a potential pediatric dose incorporated in our novel taste-masked RDST in comparison with intramuscular (IM) epinephrine 0.15 mg from EAI, the recommended and only available dosage form for children in community settings. We studied the rate and extent of epinephrine absorption in our validated rabbit model (n = 5) using a cross-over design. The positive control was IM epinephrine 0.15 mg from an EpiPen Jr®. The negative control was a placebo RDST. Tablets were placed under the tongue for 2 min. Blood samples were collected at frequent intervals and epinephrine concentrations were measured using HPLC with electrochemical detection. The mean ± SEM maximum plasma concentration (Cmax) of 16.7 ± 1.9 ng/mL at peak time (Tmax) of 21 min after sublingual epinephrine 30 mg did not differ significantly (p > 0.05) from the Cmax of 18.8 ± 1.9 ng/mL at a Tmax of 36 min after IM epinephrine 0.15 mg. The Cmax of both doses was significantly higher than the Cmax of 7.5 ± 1.7 ng/mL of endogenous epinephrine after placebo. These taste-masked RDSTs containing a 30 mg dose of epinephrine have the potential to be used as an easy-to-carry, palatable, non-invasive treatment for anaphylactic episodes for children in community settings. PMID:29439456

A predictive formula of the contraction stress in restorative and luting materials attending to free and adhered surfaces, volume and deformation.

PubMed

Miguel, A; de la Macorra, J C

2001-05-01

To find a predictive formula of stress, considering the surfaces (free, adhered) involved, the volume and characteristics of material and the deformation of the measuring system. 231 samples of five chemically cured restoratives (Silar (SIL, 23), Clearfil F2 (CLE, 39), P10 (P10, 33), Concise (CON, 30), Isopast (ISO, 28)) and four luting (3M Experimental 241 (EXM, 20), Variolink II (VAR, 13), Vitremer LC (VTM, 20) and Dyract Cem (DYR, 25)) materials were allowed to polymerize until they reached a maximum tension (T(max), 25 min) between six pairs (null 5.81, 8.5, 11.26, 12.42, 17.02, 23.14 mm) of polished metallic discs (range of distances: 0.02-5.9 mm) mounted in a tension machine. The deformation of the measuring system was measured for the recorded forces. A descriptive non-linear formula T(max)=KVol(-3.267)FS(3.283)AS(0.642)Def(0.561) was found that individualizes the material's characteristics (K) that considers volume (Vol), free (FS) and adhered (AS) surfaces and deformation (Def) of the system for each force. This formula renders good correlation (material K (r(2) coefficient)): SIL 0.9998 (0.995), CLE 1.0062 (0.989), P10 1.0224 (0.990), CON 0.9908 (0.992), ISO 0.9648 (0.974), EXM 1.0083 (0.991), VAR 0.9777 (0.996), VTM 0.9925 (0.993), DYR 0.9971 (0.997) between actual T(max) and calculated Tension. There are statistically significant differences (p=0.002) between K values of both (restorative and luting) groups. Predictive parameters have influence in a different way to what is actually considered, if the system is allowed to have deformation, as occurs naturally and volume and material's characteristics are considered.

Generalized Arcsine Laws for Fractional Brownian Motion.

PubMed

Sadhu, Tridib; Delorme, Mathieu; Wiese, Kay Jörg

2018-01-26

The three arcsine laws for Brownian motion are a cornerstone of extreme-value statistics. For a Brownian B_{t} starting from the origin, and evolving during time T, one considers the following three observables: (i) the duration t_{+} the process is positive, (ii) the time t_{last} the process last visits the origin, and (iii) the time t_{max} when it achieves its maximum (or minimum). All three observables have the same cumulative probability distribution expressed as an arcsine function, thus the name arcsine laws. We show how these laws change for fractional Brownian motion X_{t}, a non-Markovian Gaussian process indexed by the Hurst exponent H. It generalizes standard Brownian motion (i.e., H=1/2). We obtain the three probabilities using a perturbative expansion in ϵ=H-1/2. While all three probabilities are different, this distinction can only be made at second order in ϵ. Our results are confirmed to high precision by extensive numerical simulations.

Investigating the in-vitro and in-vivo flavour release from 21 fresh-cut apples.

PubMed

Ting, Valentina J L; Romano, Andrea; Soukoulis, Christos; Silcock, Patrick; Bremer, Phil J; Cappellin, Luca; Biasioli, Franco

2016-12-01

In-vitro and in-vivo flavour release from 21 different apple cultivars was studied using proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) with a focus on the relationship between texture and volatile organic compound (VOC) emission. Generally, firm-juicy cultivars had a shorter time to first swallow (Tswal) and a higher number of swallows (Nswal), while softer-mealy cultivars had a longer Tswal and a lower Nswal. Firm-juicy cultivars containing high VOC concentrations had a short time to maximum intensity (Tmax) owing to a shorter Tswal and a higher Nswal as juice was released during mastication. Swallowing increased VOC flow through the nasal cavity. These results differ from previous flavour release studies with gel/gel-like model systems as juiciness/release of fluids is not a factor in such matrices. The current study, therefore, highlights the benefits of using in-vivo analysis to gain a better understanding of flavour release in real food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparing daily temperature averaging methods: the role of surface and atmosphere variables in determining spatial and seasonal variability

NASA Astrophysics Data System (ADS)

Bernhardt, Jase; Carleton, Andrew M.

2018-05-01

The two main methods for determining the average daily near-surface air temperature, twice-daily averaging (i.e., [Tmax+Tmin]/2) and hourly averaging (i.e., the average of 24 hourly temperature measurements), typically show differences associated with the asymmetry of the daily temperature curve. To quantify the relative influence of several land surface and atmosphere variables on the two temperature averaging methods, we correlate data for 215 weather stations across the Contiguous United States (CONUS) for the period 1981-2010 with the differences between the two temperature-averaging methods. The variables are land use-land cover (LULC) type, soil moisture, snow cover, cloud cover, atmospheric moisture (i.e., specific humidity, dew point temperature), and precipitation. Multiple linear regression models explain the spatial and monthly variations in the difference between the two temperature-averaging methods. We find statistically significant correlations between both the land surface and atmosphere variables studied with the difference between temperature-averaging methods, especially for the extreme (i.e., summer, winter) seasons (adjusted R2 > 0.50). Models considering stations with certain LULC types, particularly forest and developed land, have adjusted R2 values > 0.70, indicating that both surface and atmosphere variables control the daily temperature curve and its asymmetry. This study improves our understanding of the role of surface and near-surface conditions in modifying thermal climates of the CONUS for a wide range of environments, and their likely importance as anthropogenic forcings—notably LULC changes and greenhouse gas emissions—continues.

Fetal origin of the posterior cerebral artery produces left-right asymmetry on perfusion imaging.

PubMed

Wentland, A L; Rowley, H A; Vigen, K K; Field, A S

2010-03-01

Fetal origin of the PCA is a common anatomic variation of the circle of Willis. On perfusion imaging, patients with unilateral fetal-type PCA may demonstrate left-right asymmetry that could mimic cerebrovascular disease. The aim of this study was to characterize the relationship between a fetal-type PCA and asymmetry of hemodynamic parameters derived from MR perfusion imaging. We retrospectively reviewed MR perfusion studies of 36 patients to determine the relationship between hemodynamic and vascular asymmetries in the PCA territory. Perfusion asymmetry indices for the PCA territory were computed from maps of rCBF, rCBV, MTT, T(max), and FMT. Vascular asymmetry indices were derived from calibers of the PCA-P1 segments relative to the posterior communicating arteries. Asymmetrically smaller values of FMT and T(max) were observed with unilateral fetal-type PCA, and these were strongly correlated with the degree of vascular asymmetry (Spearman's rho = 0.76 and 0.74, respectively, P < 1 x 10(-6)). Asymmetries of rCBF, MTT, and rCBV were neither significant nor related to vascular asymmetry. Faster perfusion transit times are seen for parameters sensitive to macrovascular transit effects (eg, FMT and T(max)) ipsilateral to fetal origin of the PCA in proportion to the degree of arterial asymmetry. Knowledge of this normal variation is critical in the interpretation of perfusion studies because asymmetry could mimic cerebrovascular pathology.

Growth and reproduction of the mangrove crab Goniopsis cruentata (Latreille, 1803) (Crustacea: Decapoda: Grapsidae) in southeastern Brazil.

PubMed

Reis, Carla R G; Taddei, Fabiano G; Cobo, Valter J

2015-01-01

Goniopsis cruentata is a common semi-terrestrial crab in Brazilian mangroves and an important fishery resource for traditional communities in the northeastern Brazilian coast. Aiming to contribute to the knowledge about the species, this study evaluated the carapace width and weight growth curves, the relative growth of weight versus carapace width, and the temporal variation of gonadosomatic and hepatosomatic indices for the species. A total of 524 crabs were collected in a mangrove area of Ubatuba municipality, state of São Paulo. The growth-curves parameters and longevity (tmax) were estimated for males (CW∞=50.6 mm, WE=56.4 g, k=2.24, t0=0.003631502 year-1, tmax=1.3 years) and females (CW∞=50.7 mm, WE∞=58.8 g, k=2.50, t0=0.003247209 year-1, tmax=1.2 years). The age at onset of sexual maturity was 0.23 years for both genders. The weight-growth model was isometric for the immature developmental stages and allometric negative for adults. The species exhibited a continuous reproduction, with breeding peaks in spring and summer months. The weight dynamics of gonads and hepatopancreas were not clearly related. The growth and reproductive patterns indicated that Goniopsis cruentata has a life-history that prioritizes reproduction instead of survival. The species exhibited some of the highest growth rates and lowest longevity estimates reported for brachyuran species in Brazil.

Mixed memory, (non) Hurst effect, and maximum entropy of rainfall in the tropical Andes

NASA Astrophysics Data System (ADS)

Poveda, Germán

2011-02-01

Diverse linear and nonlinear statistical parameters of rainfall under aggregation in time and the kind of temporal memory are investigated. Data sets from the Andes of Colombia at different resolutions (15 min and 1-h), and record lengths (21 months and 8-40 years) are used. A mixture of two timescales is found in the autocorrelation and autoinformation functions, with short-term memory holding for time lags less than 15-30 min, and long-term memory onwards. Consistently, rainfall variance exhibits different temporal scaling regimes separated at 15-30 min and 24 h. Tests for the Hurst effect evidence the frailty of the R/ S approach in discerning the kind of memory in high resolution rainfall, whereas rigorous statistical tests for short-memory processes do reject the existence of the Hurst effect. Rainfall information entropy grows as a power law of aggregation time, S( T) ˜ Tβ with < β> = 0.51, up to a timescale, TMaxEnt (70-202 h), at which entropy saturates, with β = 0 onwards. Maximum entropy is reached through a dynamic Generalized Pareto distribution, consistently with the maximum information-entropy principle for heavy-tailed random variables, and with its asymptotically infinitely divisible property. The dynamics towards the limit distribution is quantified. Tsallis q-entropies also exhibit power laws with T, such that Sq( T) ˜ Tβ( q) , with β( q) ⩽ 0 for q ⩽ 0, and β( q) ≃ 0.5 for q ⩾ 1. No clear patterns are found in the geographic distribution within and among the statistical parameters studied, confirming the strong variability of tropical Andean rainfall.

Comparative bioavailability of different formulations of levothyroxine and liothyronine in healthy volunteers.

PubMed

Leggio, G M; Incognito, T; Privitera, G; Marano, M R; Drago, F

2006-12-01

To evaluate the relative bioavailability of T4 sodium and liothyronine sodium (T3), administered in single doses as oral solution (drops) and tablet forms, according to two separate study protocols. Twenty-four healthy, male volunteers were included in both studies. Two test drugs containing T4 or T3 (T4-Ibsa and T3-Ibsa, respectively) were compared to two reference drugs, ie Eutirox 100 and Ti-tre tablets, respectively. A single oral dose of 100 microg (1 ml or 1 tablet) of T4 and 20 microg (1 ml or 1 tablet) of T3 were administered with an open, randomized, crossover design. T4 and T3 serum concentrations were determined by a validated immunoassay in electro-chemo-luminescence method. Study 1: after administration of T4-Ibsa oral solution, Cmax was 14.26+/-0.61 microg/dl, AUC0-t was 282.70 +/-14.29 microg/dl/h, Tmax was 2.71+/-0.25 h. After administration of Eutirox 100 tablets, Cmax was 14.34+/-0.59 microg/dl, AUC0-t was 279.42+/-9.59 microg/dl/h and Tmax was 2.65+/-0.23 h. The 90% confidence interval ratios between test/reference drugs were 1.01 for AUC0-t and 0.99 for Cmax. Study 2: after administration of T3-Ibsa oral solution, Cmax was 3.19+/-0.25 ng/ml, AUC0-t was 44.79+/-2.15 ng/ml/h and Tmax was 2.31+/-0.25 h. After administration of Ti-tre tablets, Cmax was 3.16+/-0.23 ng/ml, AUC0-t was 45.19+/-2.19 ng/ml/h and Tmax was 2.44+/-0.34 h. The 90% confidence interval ratios between test /reference drugs were 0.99 for AUC0-t and 1.01 for Cmax. The bioavailability of the two oral solutions (T4-Ibsa and T3-Ibsa oral solutions) and the corresponding tablet forms (Eutirox 100 and Ti-tre tablets) were confirmed and they can be considered bioequivalent and therapeutically interchangeable.

Pharmacokinetics of Lidocaine With Epinephrine Following Local Anesthesia Reversal With Phentolamine Mesylate

PubMed Central

Moore, Paul A; Hersh, Elliot V; Papas, Athena S; Goodson, J. Max; Yagiela, John A; Rutherford, Bruce; Rogy, Seigried; Navalta, Laura

2008-01-01

Phentolamine mesylate accelerates recovery from oral soft tissue anesthesia in patients who have received local anesthetic injections containing a vasoconstrictor. The proposed mechanism is that phentolamine, an alpha-adrenergic antagonist, blocks the vasoconstriction associated with the epinephrine used in dental anesthetic formulations, thus enhancing the systemic absorption of the local anesthetic from the injection site. Assessments of the pharmacokinetics of lidocaine and phentolamine, and the impact of phentolamine on the pharmacokinetics of lidocaine with epinephrine were performed to characterize this potentially valuable strategy. The blood levels of phentolamine were determined following its administration intraorally and intravenously. Additionally, the effects of phentolamine mesylate on the pharmacokinetics of intraoral injections of lidocaine with epinephrine were evaluated. Sixteen subjects were enrolled in this phase 1 trial, each receiving 4 drug treatments: 1 cartridge lidocaine/epinephrine followed after 30 minutes by 1 cartridge phentolamine (1L1P), 1 cartridge phentolamine administered intravenously (1Piv), 4 cartridges lidocaine/epinephrine followed after 30 minutes by 2 cartridges phentolamine (4L2P), and 4 cartridges lidocaine/epinephrine followed by no phentolamine (4L). Pharmacokinetic parameters estimated for phentolamine, lidocaine, and epinephrine included peak plasma concentration (Cmax), time to peak plasma concentration (Tmax), area under the plasma concentration-time curve from 0 to the last time point (AUClast) or from time 0 to infinity (AUCinf), elimination half-life (t1/2), clearance (CL), and volume of distribution (Vd). The phentolamine Tmax occurred earlier following the intravenous administration of 1Piv (7 minutes than following its submucosal administration in treatment 1L1P (15 minutes) or 4L2P (11 minutes). The phentolamine t1/2, CL, and Vd values were similar for 1L1P, 1Piv, and 4L2P. The Tmax for lidocaine occurred later and the Cmax for lidocaine was slightly higher when comparing the 4L2P treatment and the 4L treatment. The phentolamine-induced delay of the lidocaine Tmax likely represents phentolamine's ability to accelerate the systemic absorption of lidocaine from oral tissues into the systemic circulation. PMID:18547152

Human Microdosing with Carcinogenic Polycyclic Aromatic Hydrocarbons: In Vivo Pharmacokinetics of Dibenzo[ def,p ]chrysene and Metabolites by UPLC Accelerator Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madeen, Erin P.; Ognibene, Ted J.; Corley, Richard A.

Metabolism is a key health risk factor following exposures to pro-carcinogenic polycyclic aromatic hydrocarbons (PAHs) such as dibenzo[def,p]chrysene (DBC), an IARC classified 2A probable human carcinogen. Human exposure to PAHs occurs primarily from the diet in non-smokers. However, little data is available on the metabolism and pharmacokinetics in humans of high molecular weight PAHs (≥4 aromatic rings), including DBC. We previously determined the pharmacokinetics of DBC in human volunteers orally administered a micro-dose (29 ng; 5 nCi) of [14C]-DBC by accelerator mass spectrometry (AMS) analysis of total [14C] in plasma and urine. In the current study, we utilized a novelmore » “moving wire” interface between ultra-performance liquid chromatography (UPLC) and AMS to detect and quantify parent DBC and its major metabolites. The major [14C] product identified in plasma was unmetabolized [14C]-DBC itself, (Cmax= 18.5 ± 15.9 fg/mL, Tmax= 2.1 ± 1.0 h), whereas the major metabolite was identified as [14C]-(+/-)-DBC-11,12-diol (Cmax= 2.5 ± 1.3 fg/mL, Tmax= 1.8 h). Several minor species of [14C]-DBC metabolites were also detected for which no reference standards were available. Free and conjugated metabolites were detected in urine with [14C]-(+/-)-DBC-11,12,13,14-tetraol isomers identified as the major metabolites, 56.3% of which were conjugated (Cmax= 35.8 ± 23.0 pg/pool, Tmax= 6-12 h pool). [14C]-DBC-11,12-diol, of which 97.5% was conjugated, was also identified in urine (Cmax= 29.4 ± 11.6 pg/pool, Tmax= 6-12 h pool). Parent [14C]-DBC was not detected in urine. This is the first dataset to assess metabolite profiles and associated pharmacokinetics of a carcinogenic PAH in human volunteers at an environmentally relevant dose, providing the data necessary for translation of high dose animal models to humans for translation of environmental health risk assessment.« less

Human Micro-Dosing with Carcinogenic Polycyclic Aromatic Hydrocarbons: In Vivo Pharmacokinetics of Dibenzo[def,p]chrysene and Metabolites by UPLC Accelerator Mass Spectrometry

PubMed Central

Madeen, Erin P.; Ognibene, Ted J.; Corley, Richard A.; McQuistan, Tammie J.; Baird, William M.; Bench, Graham; Turteltaub, Ken W.; Williams, David E.

2017-01-01

Metabolism is a key health risk factor for exposures to pro-carcinogenic polycyclic aromatic hydrocarbons (PAHs) such as dibenzo[def,p]chrysene (DBC), an IARC classified 2A probable human carcinogen. Human exposure to PAHs occurs primarily from the diet in non-smokers. However, little data is available on the metabolism and pharmacokinetics in humans of high molecular weight PAHs (≥4 aromatic rings), including DBC. We previously determined the pharmacokinetics of DBC in human volunteers orally administered a micro-dose (29 ng; 5 nCi) of [14C]-DBC by accelerator mass spectrometry (AMS) analysis of total [14C] in plasma and urine. In the current study, we utilized a novel “moving wire” interface between ultra-performance liquid chromatography (UPLC) and the AMS to detect and quantify parent DBC and its major metabolites. The major [14C] product identified in plasma was unmetabolized [14C]-DBC itself, (Cmax= 18.5 ± 15.9 fg/mL, Tmax= 2.1 ± 1.0 h), whereas the major metabolite was identified as [14C]-(+/−)-DBC-11,12-diol (Cmax= 2.5 ± 1.3 fg/mL, Tmax= 1.8 h). Several minor species of [14C]-DBC metabolites were also detected for which no reference standards were available. Deconjugated and conjugated metabolites were detected in urine with [14C]-(+/−)-DBC-tetraol identified as the major metabolite, 88.7% of which was detected upon enzymatic deconjugation (Cmax= 35.8 ± 23.0 pg/pool, Tmax= 6–12 h pool). [14C]-DBC-11,12-diol, of which 94.4% was conjugated and identified in urine (Cmax= 29.4 ± 11.6 pg/pool, Tmax= 6–12 h pool). Parent [14C]-DBC was not detected in the urine. This is the first dataset to assess metabolite profiles and associated pharmacokinetics of a carcinogenic PAH in human volunteers at an environmentally relevant dose, providing the data necessary for translation of high dose laboratory animal models to human translation for environmental health risk assessment. PMID:27494294

Pharmacokinetics of quercetin absorption from apples and onions in healthy humans.

PubMed

Lee, Jihyun; Mitchell, Alyson E

2012-04-18

A high-throughput method for the extraction and analysis of quercetin in human plasma using 96-well SPE and LC-(ESI)MS/MS (7 min/run) is described. Quercetin exists as a range of glycosides in foods. The dominant types of quercetin glycosides vary depending on genetics (i.e., species and cultivar). Dietary sources include onions and apples (i.e., the peel). Herein the quercetin glycoside composition was determined in a composite standard of dried apple peel and in onion powder. The predominant forms of quercetin in apple peel include quercetin O-arabinoside, 3-O-galactoside, 3-O-glucoside, and 3-O-rhamnoside. In the onion powder, quercetin occurred as the quercetin 3,4'-O-glucoside and 4'-O-glucoside. Pharmacokinetics relating to absorption (C(max), t(max), and AUC(0-24 h)) and elimination (k(el) and t(1/2)) were compared after the consumption of apple peel powder (AP), onion powder (OP), or a mixture of the apple peel and onion powder enriched applesauce (MP) by healthy volunteers (eight females and eight males). The enriched applesauce delivered ∼100 mg of quercetin aglycone equivalents. Consumption of the OP resulted in C(max) = 273.2 ± 93.7 ng/mL, t(max) = 2.0 ± 1.7 h, and t(1/2) = 14.8 ± 4.8 h, whereas the AP resulted in C(max) = 63.8 ± 22.4 ng/mL, t(max) = 2.9 ± 2.0 h, and t(1/2) = 65.4 ± 80.0 h. The MP resulted in an intermediate response with C(max) = 136.5 ± 45.8 ng/mL, t(max) = 2.4 ± 1.5 h, and t(1/2) = 18.7 ± 6.8 h. Consumption of the OP led to faster absorption, higher concentration, and greater bioavailability as compared to the AP. No significant gender-related differences were observed in the absorption of quercetin, whereas significant gender-related differences in the elimination half-time (t(1/2)) were observed.

Selection of meteorological parameters affecting rainfall estimation using neuro-fuzzy computing methodology

NASA Astrophysics Data System (ADS)

Hashim, Roslan; Roy, Chandrabhushan; Motamedi, Shervin; Shamshirband, Shahaboddin; Petković, Dalibor; Gocic, Milan; Lee, Siew Cheng

2016-05-01

Rainfall is a complex atmospheric process that varies over time and space. Researchers have used various empirical and numerical methods to enhance estimation of rainfall intensity. We developed a novel prediction model in this study, with the emphasis on accuracy to identify the most significant meteorological parameters having effect on rainfall. For this, we used five input parameters: wet day frequency (dwet), vapor pressure (e̅a), and maximum and minimum air temperatures (Tmax and Tmin) as well as cloud cover (cc). The data were obtained from the Indian Meteorological Department for the Patna city, Bihar, India. Further, a type of soft-computing method, known as the adaptive-neuro-fuzzy inference system (ANFIS), was applied to the available data. In this respect, the observation data from 1901 to 2000 were employed for testing, validating, and estimating monthly rainfall via the simulated model. In addition, the ANFIS process for variable selection was implemented to detect the predominant variables affecting the rainfall prediction. Finally, the performance of the model was compared to other soft-computing approaches, including the artificial neural network (ANN), support vector machine (SVM), extreme learning machine (ELM), and genetic programming (GP). The results revealed that ANN, ELM, ANFIS, SVM, and GP had R2 of 0.9531, 0.9572, 0.9764, 0.9525, and 0.9526, respectively. Therefore, we conclude that the ANFIS is the best method among all to predict monthly rainfall. Moreover, dwet was found to be the most influential parameter for rainfall prediction, and the best predictor of accuracy. This study also identified sets of two and three meteorological parameters that show the best predictions.

Structure and characteristics of acid and pepsin-solubilized collagens from the skin of cobia (Rachycentron canadum).

PubMed

Zeng, Shaokui; Yin, Juanjuan; Yang, Shuqi; Zhang, Chaohua; Yang, Ping; Wu, Wenlong

2012-12-01

Acid-solubilized collagen (ASC) and pepsin-solubilized collagen (PSC) were extracted from the skin of cobia (Rachycentron canadum). The yields of ASC and PSC were 35.5% and 12.3%, respectively. Based on the protein patterns and carboxymethyl-cellulose chromatography, ASC and PSC were composed of α1α2α3 heterotrimers and were characterised as type I collagen with no disulfide bond. Their amounts of imino acids were 203 and 191 residues per 1000 residues, respectively. LC-MS/MS analysis demonstrated the high sequences similarities of ASC and PSC. Fourier transform infrared spectroscopy spectra showed that the amide I, II and III peaks of PSC were obtained at a lower wave number compared with ASC. The thermal denaturation temperatures of ASC and PSC, as measured by viscometry, were 34.62 and 33.97°C, respectively. The transition temperatures (T(max)) were 38.17 and 36.03°C, respectively, as determined by differential scanning calorimetry (DSC). Both collagens were soluble at acidic pH and below 2% (w/v) NaCl concentration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Thermal modeling in Ceuta, Maracaibo Basin, Venezuela

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marcano, F.; Padron, S.

1993-02-01

Hydrocarbon generation from Upper Cretaceous source rocks (Fm.La Luna) in Ceuta, center-eastern Maracaibo lake area in Venezuela, is modeled here, using a kinetic method and the conventional Time-Temperature Index (TTI) procedure. Geological evolution, burial and erosional history is based on available interpretation of 3D seismic and well data. Fragmentary present-day subsurface temperature data comes from corrected measurements in a few wells. Paleogradient/heat paleoflux was estimated during the thermal modeling on wells, by calculating vitrinite reflectances (Ro) or Tmax values and then comparing them with measured ones. However, thermal-indicator data does not always appear to be consistent and some data hadmore » to be rejected. Paleogradient evolution in the Cretaceous is controlled by the development of a isolated thermal compartment related to overpressures in a thick shaly sequence in the Upper Cretaceous. A geological section was studied in detail to illustrate possible migration paths to known fields and undrilled traps. Results show a good fit between the thermal evolution of the source rock and the maturity of the crude produced in the area.« less

Overview of extended release tacrolimus in solid organ transplantation

PubMed Central

Patel, Neha; Cook, Abigail; Greenhalgh, Elizabeth; Rech, Megan A; Rusinak, Joshua; Heinrich, Lynley

2016-01-01

Tacrolimus (Prograf©, Astellas Pharma Europe Ltd, Staines, United Kingdom; referred to as tacrolimus-BID) is an immunosuppressive agent to prevent and treat allograft rejection in kidney transplant recipients in combination with mycophenolate mofetil, corticosteroids, with or without basiliximab induction. The drug has also been studied in liver, heart and lung transplant; however, these are currently off-label indications. An extended release tacrolimus formulation (Advagraf©, Astagraf XL©) allows for once-daily dosing, with the potential to improve adherence. Extended release tacrolimus has similar absorption, distribution, metabolism and excretion to tacrolimus-BID. Phase I pharmacokinetic trials comparing extended release tacrolimus and tacrolimus-BID have demonstrated a decreased maximum concentration (Cmax) and delayed time to maximum concentration (tmax) with the extended release formulation; however, AUC0-24 was comparable between formulations. Overall extended release tacrolimus has a very similar safety and efficacy profile to tacrolimus-BID. It is not recommended in the use of liver transplant patient’s due to the increased risk of mortality in female recipients. There has been minimal data regarding the use of extended release tacrolimus in heart and lung transplant recipients. With the current data available for all organ groups the extended release tacrolimus should be dosed in a 1:1 fashion, the exception may be the cystic fibrosis population where their initial dose may need to be higher. PMID:27011912

Overview of extended release tacrolimus in solid organ transplantation.

PubMed

Patel, Neha; Cook, Abigail; Greenhalgh, Elizabeth; Rech, Megan A; Rusinak, Joshua; Heinrich, Lynley

2016-03-24

Tacrolimus (Prograf(©), Astellas Pharma Europe Ltd, Staines, United Kingdom; referred to as tacrolimus-BID) is an immunosuppressive agent to prevent and treat allograft rejection in kidney transplant recipients in combination with mycophenolate mofetil, corticosteroids, with or without basiliximab induction. The drug has also been studied in liver, heart and lung transplant; however, these are currently off-label indications. An extended release tacrolimus formulation (Advagraf(©), Astagraf XL(©)) allows for once-daily dosing, with the potential to improve adherence. Extended release tacrolimus has similar absorption, distribution, metabolism and excretion to tacrolimus-BID. Phase I pharmacokinetic trials comparing extended release tacrolimus and tacrolimus-BID have demonstrated a decreased maximum concentration (Cmax) and delayed time to maximum concentration (tmax) with the extended release formulation; however, AUC0-24 was comparable between formulations. Overall extended release tacrolimus has a very similar safety and efficacy profile to tacrolimus-BID. It is not recommended in the use of liver transplant patient's due to the increased risk of mortality in female recipients. There has been minimal data regarding the use of extended release tacrolimus in heart and lung transplant recipients. With the current data available for all organ groups the extended release tacrolimus should be dosed in a 1:1 fashion, the exception may be the cystic fibrosis population where their initial dose may need to be higher.

Comparative bioequivalence study of rifampicin and isoniazid combinations in healthy volunteers.

PubMed

Padgaonkar, K A; Revankar, S N; Bhatt, A D; Vaz, J A; Desai, N D; D'Sa, S; Shah, V; Gandewar, K

1999-07-01

To assess the bioavailability of rifampicin (RMP) in three brands of combination formulations of anti-tuberculosis drugs. A three-way double-blind, cross-over bioavailability study of RMP and isoniazid (INH), consisting of a comparison of a two-drug combination of tablets of RMP and INH each separately (reference brand R) and a tablet of RMP + INH (brand N), and a capsule of RMP + INH (brand L) was carried out in 12 healthy male volunteers. Coded plasma samples were analysed for levels of RMP as well as INH and acetylisoniazid (ACINH) by two high performance liquid chromatography (HPLC) methods. The mean values of RMP in brand N (Cmax 6.49+/-0.52 microg/mL, Tmax 2.33+/-0.18 h, AUC(0-24h) 39.83+/-3.44 microg/mL.h) were comparable with those obtained with brand R (Cmax 5.22+/-0.59 microg/mL, Tmax 2.50+/-0.12 h, AUC(0-24h) 33.33+/-3.47 microg/mL.h). The mean values of RMP in brand L (Cmax 3.05+/-0.52 microg/ mL, Tmax 3.79+/-0.57 h and AUC(0-24h) 21.78+/-3.67 microg/ mL.h) were significantly different from those in brand R. Nevertheless, all of the pharmacokinetic parameters obtained for INH and ACINH in all three brands were comparable. Using brand R as a comparison, brand N was bioequivalent and brand L was not bioequivalent.

Petrographic maturity parameters of a Devonian shale maturation series, Appalachian Basin, USA. ICCP Thermal Indices Working Group interlaboratory exercise

USGS Publications Warehouse

Araujo, Carla Viviane; Borrego, Angeles G.; Cardott, Brian; das Chagas, Renata Brenand A.; Flores, Deolinda; Goncalves, Paula; Hackley, Paul C.; Hower, James C.; Kern, Marcio Luciano; Kus, Jolanta; Mastalerz, Maria; Filho, João Graciano Mendonça; de Oliveira Mendonça, Joalice; Rego Menezes, Taissa; Newman, Jane; Suarez-Ruiz, Isabel; Sobrinho da Silva, Frederico; Viegas de Souza, Igor

2014-01-01

This paper presents results of an interlaboratory exercise on organic matter optical maturity parameters using a natural maturation series comprised by three Devonian shale samples (Huron Member, Ohio Shale) from the Appalachian Basin, USA. This work was conducted by the Thermal Indices Working Group of the International Committee for Coal and Organic Petrology (ICCP) Commission II (Geological Applications of Organic Petrology). This study aimed to compare: 1. maturation predicted by different types of petrographic parameters (vitrinite reflectance and spectral fluorescence of telalginite), 2. reproducibility of the results for these maturation parameters obtained by different laboratories, and 3. improvements in the spectral fluorescence measurement obtained using modern detection systems in comparison with the results from historical round robin exercises.Mean random vitrinite reflectance measurements presented the highest level of reproducibility (group standard deviation 0.05) for low maturity and reproducibility diminished with increasing maturation (group standard deviation 0.12).Corrected fluorescence spectra, provided by 14 participants, showed a fair to good correspondence. Standard deviation of the mean values for spectral parameters was lowest for the low maturity sample but was also fairly low for higher maturity samples.A significant improvement in the reproducibility of corrected spectral fluorescence curves was obtained in the current exercise compared to a previous investigation of Toarcian organic matter spectra in a maturation series from the Paris Basin. This improvement is demonstrated by lower values of standard deviation and is interpreted to reflect better performance of newer photo-optical measuring systems.Fluorescence parameters measured here are in good agreement with vitrinite reflectance values for the least mature shale but indicate higher maturity than shown by vitrinite reflectance for the two more mature shales. This red shift in λmax beyond 0.65% vitrinite reflectance was also observed in studies of Devonian shale in other basins, suggesting that the accepted correlation for these two petrographic thermal maturity parameters needs to be re-evaluated.A good linear correlation between λmax and Tmax for this maturation series was observed and λmax 600 nm corresponds to Tmax of 440 °C. Nevertheless if a larger set of Devonian samples is included, the correlation is polynomial with a jump in λmax ranging from 540 to 570 nm. Up to 440 °C of Tmax, the λmax, mostly, reaches up to 500 nm; beyond a Tmax of 440 °C, λmax is in the range of 580–600 nm. This relationship places the “red shift” when the onset of the oil window is reached at Tmax of 440 °C. Moreover, the correlation between HI and λmax (r2 = 0.70) shows a striking inflection and decrease in HI above a λmax of 600 nm, coincident with the approximate onset of hydrocarbon generation in these rocks.

Effects of isothermal and cyclic exposures on interface structure and mechanical properties of FPalpha-Al2O3/aluminum composites. [polycrystaline alumina fibers

NASA Technical Reports Server (NTRS)

Kim, W. M.; Koczak, M. J.; Lawley, A.

1979-01-01

The microstructural and interface stability of FPalpha-Al203/Al-Li composites are investigated as a function of isothermal exposure at 500 C or thermal cycling between 140 and 500 C with hold time at Tmax. Interfacial morphology, growth kinetics, crystal structure, and composition of interfacial reaction products are characterized. Strength is monitored in the transverse orientation, and fracture mechanics is analyzed in terms of interface reaction products. The interfacial reaction product in FP/Al is Li2O.5Al2O3. Significant fiber-matrix reaction occurs during fabrication. The number of thermal cycles rather than total time at Tmax is the determining factor in strength degradation, thermal cycling giving rise to voids at the fiber-matrix interface. Extensive interface failures occur at composite fracture stresses below about 128 MPa; above this stress level failure is attributed to ductile matrix fracture.

Temperature initiated passive cooling system

DOEpatents

Forsberg, Charles W.

1994-01-01

A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature.

Hydrothermal Activity on the Mid-Cayman Rise: ROV Jason sampling and site characterization at the Von Damm and Piccard hydrothermal fields

NASA Astrophysics Data System (ADS)

German, C. R.

2012-12-01

In January 2012 our multi-national and multi-disciplinary team conducted a series of 10 ROV Jason dives to conduct first detailed and systematic sampling of the Mid Cayman Rise hydrothermal systems at the Von Damm and Piccard hydrothermal fields. At Von Damm, hydrothermal venting is focused at and around a large conical structure that is approximately 120 m in diameter and rises at least 80m from the surrounding, largely sedimented seafloor. Clear fluids emitted from multiple sites around the flanks of the mound fall in the temperature range 110-130°C and fall on a common mixing line with hotter (>200°C) clear fluids emitted from an 8m tall spire at the summit which show clear evidence of ultramafic influence. Outcrop close to the vent-site is rare and the cone itself appear to consist of clay minerals derived from highly altered host rock. The dominant fauna at the summit of Von Damm are a new species of chemosynthetic shrimp but elsewhere the site also hosts two distinct species of chemosynthetic tube worm as well as at least one species of gastropod. The adjacent Piccard site, at ~5000m depth comprises 7 distinct sulfide mounds, 3 of which are currently active: Beebe Vents, Beebe Woods and Beebe Sea. Beebe Vents consists of 5 vigorous black smoker chimneys with maximum temperatures in the range 400-403°C while at Beebe Woods a more highly colonized thicket of up to 8m tall chimneys includes predominantly beehive diffusers with rare black smokers emitting fluids up to 353°C. Beebe Sea a diffuse site emitting fluids at 38°C Tmax, is the largest of the currently active mounds and immediately abuts a tall (8m) rift that strikes NE-SW bisecting the host Axial Volcanic Ridge. The fauna at Piccard are less diverse than at Von Damm and, predominantly, comprise the same species of MCR shrimp, a distinct gastropod species and abundant anemones.

Preparation and in vitro and in vivo evaluation of HupA PLGA microsphere.

PubMed

Ye, Liang; Fu, Fenghua; Liu, Wanhui; Sun, Kaoxiang; Li, Youxin; He, Jie; Yu, Xin; Yu, Pengfei; Tian, Jingwei

2013-03-01

Acetylcholinesterase inhibitors (AChEIs), including Huperzine A (HupA), have been the mainstay of treatment for Alzheimer's disease (AD). However, AChEIs can cause gastrointestinal side effects, which has been related to the high Cmax and short tmax after oral administration. Clinical trials have verified that extended-release formulation with lower Cmax and prolonged tmax, such as rivastigmine patch, could perform a similar efficacy with significantly improved tolerability compared with the oral formulations. In this study, we developed an extended-release microspheres formulation of HupA (called as HAM) with poly(lactide-co-glycolide) (PLGA) as drug carrier. HAM has showed the loading rate as 1.35% (w/w) and yielded 42% with mean particle size at 72.6 μm. In vitro and in vivo pharmacokinetics studies have showed that HAM produced a relatively smooth and continuous drug concentration in 14 days. Furthermore, in vivo pharmacokinetics data have demonstrated that the Cmax was lower and the tmax was considerably later in single intramuscular administration of HAM (1,000 μg/kg) than the counterparts in single intragastric administration of HAT (75 μg/kg/d). Meanwhile, HAM has performed a continuous inhibition to brain AChE activity in normal rats and improvement of memory deficit in Aβ1-40 i.c.v. infused AD rat model for 14 days. The results have suggested that HAM has performed good extended-release properties and good prolonged pharmacological efficacy in vivo in the 2-week period, and could exert a similar efficacy with significantly lowered gastrointestinal side effects as compared with oral formulation.

Disposition and metabolism of safinamide, a novel drug for Parkinson's disease, in healthy male volunteers.

PubMed

Leuratti, Chiara; Sardina, Marco; Ventura, Paolo; Assandri, Alessandro; Müller, Markus; Brunner, Martin

2013-01-01

Absorption, biotransformation and elimination of safinamide, an enantiomeric α-aminoamide derivative developed as an add-on therapy for Parkinson's disease patients, were studied in healthy volunteers administered a single oral dose of 400 mg (14)C safinamide methanesulphonate, labelled in metabolically stable positions. Pharmacokinetics of the parent compound were investigated up to 96 h, of (14)C radioactivity up to 192/200 h post-dose. Maximum concentration was achieved at 1 h (plasma, median Tmax) for parent drug and at 7 and 1.5 h for plasma and whole blood (14)C radioactivity, respectively. Terminal half-lives were about 22 h for unchanged safinamide and 80 h for radioactivity. Safinamide deaminated acid and the N-dealkylated acid were identified as major metabolites in urine and plasma. In urine, the β-glucuronide of the N-dealkylated acid and the monohydroxy safinamide were also characterized. In addition, the glycine conjugate of the N-dealkylated acid and 2-[4-hydroxybenzylamino]propanamide were tentatively identified as minor urinary metabolites. © 2013 S. Karger AG, Basel.

Elevating bioavailability of cyclosporine a via encapsulation in artificial oil bodies stabilized by caleosin.

PubMed

Chen, Miles C M; Wang, Jui-Ling; Tzen, Jason T C

2005-01-01

To elevate its bioavailability via oral administration, cyclosporine A (CsA), a hydrophobic drug, was either incorporated into olive oil directly or encapsulated in artificial oil bodies (AOBs) constituted with olive oil and phospholipid in the presence or absence of recombinant caleosin purified from Escherichia coli. The bioavailabilities of CsA in these formulations were assessed in Wistar rats in comparison with the commercial formulation, Sandimmun Neoral. Among these tests, CsA-loaded AOBs stabilized by the recombinant caleosin exhibited better bioavailability than the commercial formulation and possessed the highest maximum whole blood concentration (C(max)), 1247.4 +/- 106.8 ng/mL, in the experimental animals 4.3 +/- 0.7 h (t(max)) after oral administration. C(max) and the area under the plasma concentration-time curve (AUC(0-24)) were individually increased by 50.8% and 71.3% in the rats fed with caleosin-stabilized AOBs when compared with those fed with the reference Sandimmun Neoral. The results suggest that constitution of AOBs stabilized by caleosin may be a suitable technique to encapsulate hydrophobic drugs for oral administration.

Adverse Climatic Conditions and Impact on Construction Scheduling and Cost

DTIC Science & Technology

1988-01-01

ABBREVIATIONS ABS MAX MAX TEMP ...... Absolute maximum maximum temperature ABS MIN MIN TEMP ...... Absolute minimum minimum temperature BTU...o Degrees Farenheit MEAN MAX TEMP o.................... Mean maximum temperature MEAN MIN TEMP...temperatures available, a determination had to be made as to whether forecasts were based on absolute , mean, or statistically derived temperatures

Temperature initiated passive cooling system

DOEpatents

Forsberg, C.W.

1994-11-01

A passive cooling system for cooling an enclosure only when the enclosure temperature exceeds a maximum standby temperature comprises a passive heat transfer loop containing heat transfer fluid having a particular thermodynamic critical point temperature just above the maximum standby temperature. An upper portion of the heat transfer loop is insulated to prevent two phase operation below the maximum standby temperature. 1 fig.

Relationships between data from Rock-Eval pyrolysis and proximate, ultimate, petrographic, and physical analyses of 142 diverse U.S. coal samples

USGS Publications Warehouse

Bostick, N.H.; Daws, T.A.

1994-01-01

Basic research on coal and oil shale led to automated pyrolysis analysis of petroleum source rocks; most widely used is the Rock-Eval equipment. In order to interpret Rock-Eval analyses in relation to traditional coal data, we analyzed 142 commercial coals with diverse rank, age, maceral and sulfur contents, for most regions of the United States. We compared the Rock-Eval data with traditional industrial coal data, including volatile matter, calorific value, hydrogen and oxygen content, free swelling index, and vitrinite reflectance. We found: (1) there is a close relationship between Tmax and vitrinite reflectance in the ranges 420-590??C Tmax and 0.4-3%Romax of most coals. (2) A close relationship between Tmax and volatile matter (%VM) extends through the entire sample range, including low-rank samples with 35-70% VM, a range where %VM is not considered to be a useful rank parameter. (3) TOC of medium- and high-rank coals is seriously under-measured by Rock-Eval; TOC of low-rank coals (less than 0.8%Romax) is close to "dry basis" carbon from ultimate analysis. (4) The direct relationships between oxygen index (OI) and %O and between hydrogen index (HI) and %H are clear, though only broadly defined. However, there is virtually no band of concentrated data points on the HI versus OI pseudo-Van Krevelen diagram comparable to the "development line" on the H/C versus O/C diagram. (5) There are systematic relationships between Rock-Eval and industrial coal parameters such as calorific value and FSI, but much standardization would be needed before Rock-Eval could find a place in the coal industry. Tests with blends of coal and quartz sand and with various loads of coal alone showed that the amount of organic matter in the Rock-Eval load greatly influences results. Total load in the crucible, if largely inert, plays a small role, however. Increasing absolute or relative coal content causes under-evaluation of Rock-Eval TOC and over-rating of hydrogen. Blends of several coals yielded hydrogen and oxygen indexes related proportionally to the properties of the individual coals, but Tmax is not raised by addition of high-rank coal until over 40% is added. ?? 1994.

Accuracy and Reliability Assessment of CT and MR Perfusion Analysis Software Using a Digital Phantom

PubMed Central

Christensen, Soren; Sasaki, Makoto; Østergaard, Leif; Shirato, Hiroki; Ogasawara, Kuniaki; Wintermark, Max; Warach, Steven

2013-01-01

Purpose: To design a digital phantom data set for computed tomography (CT) perfusion and perfusion-weighted imaging on the basis of the widely accepted tracer kinetic theory in which the true values of cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and tracer arrival delay are known and to evaluate the accuracy and reliability of postprocessing programs using this digital phantom. Materials and Methods: A phantom data set was created by generating concentration-time curves reflecting true values for CBF (2.5–87.5 mL/100 g per minute), CBV (1.0–5.0 mL/100 g), MTT (3.4–24 seconds), and tracer delays (0–3.0 seconds). These curves were embedded in human brain images. The data were analyzed by using 13 algorithms each for CT and magnetic resonance (MR), including five commercial vendors and five academic programs. Accuracy was assessed by using the Pearson correlation coefficient (r) for true values. Delay-, MTT-, or CBV-dependent errors and correlations between time to maximum of residue function (Tmax) were also evaluated. Results: In CT, CBV was generally well reproduced (r > 0.9 in 12 algorithms), but not CBF and MTT (r > 0.9 in seven and four algorithms, respectively). In MR, good correlation (r > 0.9) was observed in one-half of commercial programs, while all academic algorithms showed good correlations for all parameters. Most algorithms had delay-dependent errors, especially for commercial software, as well as CBV dependency for CBF or MTT calculation and MTT dependency for CBV calculation. Correlation was good in Tmax except for one algorithm. Conclusion: The digital phantom readily evaluated the accuracy and characteristics of the CT and MR perfusion analysis software. All commercial programs had delay-induced errors and/or insufficient correlations with true values, while academic programs for MR showed good correlations with true values. © RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112618/-/DC1 PMID:23220899

Pharmacokinetics of promethazine hydrochloride after administration of rectal suppositories and oral syrup to healthy subjects.

PubMed

Strenkoski-Nix, L C; Ermer, J; DeCleene, S; Cevallos, W; Mayer, P R

2000-08-15

The pharmacokinetics of promethazine hydrochloride after administration of rectal suppositories at three dosage strengths and oral syrup were studied. The study had an open-label, randomized, crossover design. At intervals of five to nine days, healthy volunteers were given two 12.5-mg promethazine rectal suppositories, one 25-mg suppository, one 50-mg suppository, or 50 mg (10 mL) of promethazine oral syrup. Blood samples were collected before each dose and at intervals from 0.5 to 48 hours afterward. Promethazine concentration was determined by high-performance liquid chromatography, and pharmacokinetic values were calculated with noncompartmental methods. Thirty-six subjects (18 men and 18 women) completed the study. Absorption was highly variable for all the formulations. On average, absorption was more rapid and the maximum plasma concentration (Cmax) higher for the syrup than for the suppositories. Cmax was significantly lower for the 50-mg suppository (mean, 9.04 ng/mL) than for the syrup (19.3 ng/mL). The time to Cmax (tmax) was significantly shorter for the syrup (mean, 4.4 hours) than for the suppositories (6.7-8.6 hours). There were no significant differences in dose-normalized Cmax among the three suppository treatments. Area under the concentration-versus-time curve (AUC) was comparable between the syrup and the 50-mg suppository and between the treatments with two 12.5-mg suppositories and the 25-mg suppository. Elimination profiles were similar among all treatments (mean half-life [t1/2], 16-19 hours). There were no significant differences in pharmacokinetics on the basis of sex or race. The mean relative bioavailability for the three suppository treatments ranged from 70% to 97%. Individual relative bioavailabilities ranged from 4% to 343%. The pharmacokinetics of promethazine administered in oral syrup and rectal suppositories were highly variable, but, in general, the suppositories produced a lower Cmax and later tmax than the syrup. All formulations were comparable in terms of dose-normalized AUC and t1/2, and the three suppository treatments were comparable in terms of dose-normalized Cmax.

Theoretical considerations in measurement of time discrepancies between input and myocardial time-signal intensity curves in estimates of regional myocardial perfusion with first-pass contrast-enhanced MRI.

PubMed

Natsume, Takahiro; Ishida, Masaki; Kitagawa, Kakuya; Nagata, Motonori; Sakuma, Hajime; Ichihara, Takashi

2015-11-01

The purpose of this study was to develop a method to determine time discrepancies between input and myocardial time-signal intensity (TSI) curves for accurate estimation of myocardial perfusion with first-pass contrast-enhanced MRI. Estimation of myocardial perfusion with contrast-enhanced MRI using kinetic models requires faithful recording of contrast content in the blood and myocardium. Typically, the arterial input function (AIF) is obtained by setting a region of interest in the left ventricular cavity. However, there is a small delay between the AIF and the myocardial curves, and such time discrepancies can lead to errors in flow estimation using Patlak plot analysis. In this study, the time discrepancies between the arterial TSI curve and the myocardial tissue TSI curve were estimated based on the compartment model. In the early phase after the arrival of the contrast agent in the myocardium, the relationship between rate constant K1 and the concentrations of Gd-DTPA contrast agent in the myocardium and arterial blood (LV blood) can be described by the equation K1={dCmyo(tpeak)/dt}/Ca(tpeak), where Cmyo(t) and Ca(t) are the relative concentrations of Gd-DTPA contrast agent in the myocardium and in the LV blood, respectively, and tpeak is the time corresponding to the peak of Ca(t). In the ideal case, the time corresponding to the maximum upslope of Cmyo(t), tmax, is equal to tpeak. In practice, however, there is a small difference in the arrival times of the contrast agent into the LV and into the myocardium. This difference was estimated to correspond to the difference between tpeak and tmax. The magnitudes of such time discrepancies and the effectiveness of the correction for these time discrepancies were measured in 18 subjects who underwent myocardial perfusion MRI under rest and stress conditions. The effects of the time discrepancies could be corrected effectively in the myocardial perfusion estimates. Copyright © 2015 Elsevier Inc. All rights reserved.

[Pharmacokinetics of magnolol and honokiol in Weichang'an pill].

PubMed

Chen, Yu-Ling; Wang, Shu-Ping; Wang, Lei; Jin, Zhao-Xiang; Zhang, Jing-Ze; Chen, Hong; Gao, Wen-Yuan

2016-05-01

To conduct multiple-reaction monitoring(MRM) quantitative analysis with high-performance liquid chromatography coupled with mass spectrometry method, establish the quantification method of magnolol and honokiol in blood sample under negative ion mode with ibuprofen as internal standard, investigate the pharmacokinetic process of lignans constituents after oral administration of Weichang'an pill(WCA) at different doses, and provide theoretical basis to further reveal the material basis of WCA's anti-diarrhea effect. In the plasma samples, the linear relationship was good over the concentration range of 5.25 to 1 344.00 μg•L ⁻¹ for magnolol and 10.08 to 2 580.00 μg•L ⁻¹ for honokiol. The results of precision, stability, and extraction recovery tests showed that the determination method of plasma concentration for such compositions was stable and reliable. Dose-dependence was shown for magnolol and honokiol in the plasma concentration-time profile. The results indicated that the time to reach the maximum plasma concentration(Tmax) for lignanoids was 0.55-1.42 h, when the maximum plasma concentration(Cmax) could reach 996.36-2 330.96,189.87-1 469.43 μg•L ⁻¹ respectively for magnolol and honokiol. The lignanoids could be absorbed rapidly in the blood after oral administration of WAC pills, providing experimental basis to prove rapid and long-acting anti-diarrhea effect of WAC pills after oral administration. Copyright© by the Chinese Pharmaceutical Association.

In Vivo Absorption and Disposition of Cefadroxil after Escalating Oral Doses in Wild-Type and PepT1 Knockout Mice

PubMed Central

Posada, Maria M.; Smith, David E.

2013-01-01

Purpose To determine the effect of PepT1 on the absorption and disposition of cefadroxil, including the potential for saturable intestinal uptake, after escalating oral doses of drug. Methods The absorption and disposition kinetics of [3H]cefadroxil was determined in wild-type and PepT1 knockout mice after 44.5, 89.1, 178, and 356 nmol/g oral doses of drug. The pharmacokinetics of [3H]cefadroxil was also determined in both genotypes after 44.5 nmol/g intravenous bolus doses. Results PepT1 deletion reduced the area under the plasma concentration-time profile (AUC0-120) of cefadroxil by 10-fold, the maximum plasma concentration (Cmax) by 17.5-fold, and increased the time to reach a maximum plasma concentration (Tmax) by 3-fold. There was no evidence of nonlinear intestinal absorption since AUC0-120 and Cmax values changed in a dose-proportional manner. Moreover, the pharmacokinetics of cefadroxil was not different between genotypes after intravenous bolus doses, indicating that PepT1 did not affect drug disposition. Finally, no differences were observed in the peripheral tissue distribution of cefadroxil (i.e., outside gastrointestinal tract) once these tissues were corrected for differences in perfusing blood concentrations. Conclusions The findings demonstrate convincingly the critical role of intestinal PepT1 in both the rate and extent of oral administration for cefadroxil and potentially other aminocephalosporin drugs. PMID:23959853

The absorption profile of pregabalin in chronic pancreatitis.

PubMed

Olesen, Anne E; Olofsen, Erik; Olesen, Søren S; Staahl, Camilla; Andresen, Trine; Dahan, Albert; Drewes, Asbjørn M

2012-12-01

It was recently shown that pregabalin decreased pain associated with chronic pancreatitis. It is well known that pancreatitis patients suffer from fat malabsorption with accompanying diarrhoea because of loss of exocrine pancreatic enzyme production. This may lead to changes in the mucosal surface in the small intestine and possibly affect the absorption of pregabalin. The pharmacokinetics of pregabalin has never been investigated in patients suffering from chronic pancreatitis. The aim of this study was to develop a population pharmacokinetic model of pregabalin administered to patients with chronic pancreatitis. The pregabalin population pharmacokinetic analysis was conducted on data from fifteen patients with chronic pancreatitis. Each patient received 75 mg of pregabalin (oral capsule). Pregabalin concentrations were measured using a validated liquid chromatographic method. Data analysis was performed using non-linear mixed effects modelling methodology as implemented by NONMEM. A one-compartment model with first-order absorption and elimination adequately described pregabalin pharmacokinetics. Time to maximum observed plasma concentration (T(max) ) was 1.53 (95% CI 1.09-2.05). The maximum plasma concentration (C(max) ) was 1.98 μg/ml (95% CI 1.69-2.34), and area under the plasma concentration-time profile (area under the curve) was 18.2 μg*hr/ml (95% CI 14.7-26.3). Pregabalin is well absorbed in patients with chronic pancreatitis, and the pharmacokinetic profile of pregabalin is not extensively affected by chronic pancreatitis. © 2012 The Authors Basic & Clinical Pharmacology & Toxicology © 2012 Nordic Pharmacological Society.

Traction cytometry: regularization in the Fourier approach and comparisons with finite element method.

PubMed

Kulkarni, Ankur H; Ghosh, Prasenjit; Seetharaman, Ashwin; Kondaiah, Paturu; Gundiah, Namrata

2018-05-09

Traction forces exerted by adherent cells are quantified using displacements of embedded markers on polyacrylamide substrates due to cell contractility. Fourier Transform Traction Cytometry (FTTC) is widely used to calculate tractions but has inherent limitations due to errors in the displacement fields; these are mitigated through a regularization parameter (γ) in the Reg-FTTC method. An alternate finite element (FE) approach computes tractions on a domain using known boundary conditions. Robust verification and recovery studies are lacking but essential in assessing the accuracy and noise sensitivity of the traction solutions from the different methods. We implemented the L2 regularization method and defined a maximum curvature point in the traction with γ plot as the optimal regularization parameter (γ*) in the Reg-FTTC approach. Traction reconstructions using γ* yield accurate values of low and maximum tractions (Tmax) in the presence of up to 5% noise. Reg-FTTC is hence a clear improvement over the FTTC method but is inadequate to reconstruct low stresses such as those at nascent focal adhesions. FE, implemented using a node-by-node comparison, showed an intermediate reconstruction compared to Reg-FTTC. We performed experiments using mouse embryonic fibroblast (MEF) and compared results between these approaches. Tractions from FTTC and FE showed differences of ∼92% and 22% as compared to Reg-FTTC. Selection of an optimum value of γ for each cell reduced variability in the computed tractions as compared to using a single value of γ for all the MEF cells in this study.

Evaluation of Ultra High Pressure (UHP) Firefighting in a Room-and-Contents Fire

DTIC Science & Technology

2017-03-15

Burn Room and Hangar Temperature Prior to Ignition ............................................... 18 Figure 12. Effect of Temperature on Normalized...Figure 20. Maximum Average Temperature and Heat Flux ......................................................... 22 Figure 21. Effect of Maximum Average...Aspirated Ceiling Temperature .................................... 23 Figure 22. Effect of Maximum Average Floor Heat Flux on Extinguishment Quantity

Safety and pharmacokinetics of oral cannabidiol when administered concomitantly with intravenous fentanyl in humans

PubMed Central

Manini, Alex F.; Yiannoulos, Georgia; Bergamaschi, Mateus M.; Hernandez, Stephanie; Olmedo, Ruben; Barnes, Allan J.; Winkel, Gary; Sinha, Rajita; Jutras-Aswad, Didier; Huestis, Marilyn A.; Hurd, Yasmin L.

2015-01-01

Objectives Cannabidiol (CBD) is hypothesized as a potential treatment for opioid addiction, with safety studies an important first step for medication development. We determined CBD safety and pharmacokinetics when administered concomitantly with a high-potency opioid in healthy subjects. Methods This double-blind, placebo-controlled cross-over study of CBD co-administered with intravenous fentanyl, was conducted at the Clinical Research Center in Mount Sinai Hospital, a tertiary care medical center in New York City. Participants were healthy volunteers aged 21–65 years with prior opioid exposure, regardless of route. Blood samples were obtained before and after 400 or 800 mg CBD pretreatment, followed by a single 0.5 (Session 1) or 1.0mcg/Kg (Session 2) intravenous fentanyl dose. The primary outcome was the Systematic Assessment for Treatment Emergent Events (SAFTEE) to assess safety and adverse effects. CBD peak plasma concentrations, time to reach peak plasma concentrations (tmax), and area under the curve (AUC) were measured. Results SAFTEE data were similar between groups without respiratory depression or cardiovascular complications during any test session. Following low dose CBD, tmax occurred at 3 and 1.5h (Sessions 1 and 2, respectively). Following high dose CBD, tmax occurred at 3 and 4h in Sessions 1 and 2, respectively. There were no significant differences in plasma CBD or cortisol (AUC p=NS) between sessions. Conclusions CBD does not exacerbate adverse effects associated with intravenous fentanyl administration. Co-administration of CBD and opioids was safe and well tolerated. These data provide the foundation for future studies examining CBD as a potential treatment for opioid abuse. PMID:25748562

Pharmacokinetics study of ferulic acid in rats after oral administration of γ-oryzanol under combined use of Tween 80 by LC/MS/MS.

PubMed

Pan, Y; Cai, L; He, S; Zhang, Z

2014-01-01

γ-oryzanol (OZ) is a rich source of commercially-important bioactive phytochemicals, most of them of interest in nutrition, pharmacy and cosmetics. However, the poor solubility of OZ limited the use. In the paper, ultraviolet-visible (UV-Vis) analysis was conducted to analysis the solubilization of OZ under combined use of Tween 80 in vitro. In addition, to further confirm the solubilizing effect of Tween 80, a pharmacokinetic study of ferulic acid (FA) in rats after oral administration of OZ 100 mg/kg under combined use of Tween 80 though LCMS/MS was carried out. Solubility enhancement as high as 100-fold is achieved using 1% Tween 80 in vitro. Following oral administration of OZ-Tween 80 100 mg/kg, the values of Tmax, Cmax, AUC0-∞, T1/2Ka and MRT0-∞ were 46.667 ± 39.328, 129.498 ± 27.025, 63738.28 ± 599, 14.274 ± 7.309 and 859.592 ± 108.780 respectively. The values of T1/2Ka, AUC0-∞, MRT0-t, and Tmax showed up to increase 16%, 58%, 44% and 47% while Cmax and CL/F decreased 22% and 12%, respectively. The decreased Cmax value indicated that Tween 80 can hardly enhance the absorption of FA in rats. However, T1/2Ka and Tmax values showed that the absorption of FA was extended, which resulted the increased values of AUC0-∞ and MRT0-∞. Our results reveal that Tween 80 improves solubility of OZ in vitro and could enhance the bioavailability of OZ by extending its absorption and elimination.

Objective Measurement of Arterial Flow Before and After Transcatheter Arterial Chemoembolization: A Feasibility Study Using Quantitative Color-Coding Analysis.

PubMed

Lin, Yi-Yang; Lee, Rheun-Chuan; Tseng, Hsiuo-Shan; Liu, Chien-An; Guo, Wan-Yuo; Chang, Cheng-Yen

2015-12-01

To quantitatively measure the hemodynamic change of hepatic artery before and after transcatheter arterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) by quantitative color-coding analysis (QCA). This prospective study registered 64 consecutive HCC patients who underwent segmental or subsegmental TACE with epirubicin and lipiodol at level 2 or 3 of the subjective angiographic chemoembolization endpoint. QCA was used to determine the maximal density time (T(max)) of selected intravascular region of interest (ROI). Relative T(max) (rT(max)) was defined as the T(max) at the selected ROI minus the time of contrast medium spurting from the catheter tip. The rT(max) of hepatic arteries was analyzed before and after embolization. The pre- and post-treatment rT(max) of the landmarks at the treated segmental artery were 1.96 ± 0.48 and 3.14 ± 1.77 s, p < 0.001. According to the treated lobe, 30 patients were treated for the right lobe alone, and 8 patients were treated for the left lobe alone. The pre- and post-rT(max) of treated segmental artery were 2.06 ± 0.54, 3.34 ± 1.63 s, p < 0.001 and 1.89 ± 0.45, 2.68 ± 1.46 s, p = 0.12, respectively. The rT(max) of the proximal lobar hepatic arteries or proper hepatic artery had no significant change before and after TACE. The QCA is feasible to quantify embolization endpoints by comparing the rT(max) in selected hepatic arteries before and after TACE. The rT(max) of treated segmental artery was significant prolonged after optimized procedures.

Differential pharmacokinetics of diclofenac potassium for oral solution vs immediate-release tablets from a randomized trial: effect of fed and fasting conditions.

PubMed

Chen, Cuiping; Bujanover, Shay; Kareht, Stephanie; Rapoport, Alan M

2015-02-01

To compare the pharmacokinetics of, and food effect on, diclofenac potassium delivered as an oral solution vs an immediate-release tablet. Diclofenac potassium for oral solution is the only nonsteroidal anti-inflammatory drug approved as monotherapy for the acute treatment of migraine attacks with or without aura in adults 18 years of age or older. It is formulated with potassium bicarbonate as a buffering agent to raise the pH and consequently increase the aqueous solubility of diclofenac in the acidic environment of the stomach following oral administration. The dosage is 50 mg of powdered diclofenac potassium dissolved in 1 to 2 ounces (30 to 60 mL) of water prior to administration, with dosing time in relation to food intake not specified - this was the case for the pivotal efficacy and safety trials in subjects with acute migraine attacks in which the primary endpoints were achieved. For acute treatment of migraine attacks, rapid onset of pain relief is desirable and is likely related to a rapid appearance of an effective concentration of the drug in the systemic circulation. The rate at which an orally administered drug reaches the blood is affected by both its formulation and the presence of food in the stomach. The present study was designed to investigate the pharmacokinetics of 2 formulations of diclofenac potassium, an immediate-release tablet and an oral solution, and to ascertain the effect of food. This was an open-label, randomized, single-center, crossover trial in healthy volunteers. Subjects were randomized using computer-generated list to 1:1:1:1 ratio. They received a single 50-mg dose of diclofenac potassium in 4 sequences (ABCD, BADC, CDBA, and DCAB) during each of the 4 treatment periods. The 4 treatments were: A, oral solution fasting; B, tablet fasting; C, oral solution fed; and D, tablet fed. There was a ≥7-day washout period between dosing. Blood samples for pharmacokinetic analysis were taken for up to 12 hours post-dose and analyzed for diclofenac concentrations. Pharmacokinetic parameters, including peak concentration (Cmax ), time to Cmax (tmax ), area under the concentration-time curve (AUC) from time 0 to last measurable concentration (AUCt ), and extrapolation to infinity (AUC∞ ) were obtained using non-compartmental analysis. Comparative assessments for Cmax and AUC were performed between the solution and tablet under fed and fasting conditions and between fed and fasting states for both formulations. Bioequivalent exposure was defined as the geometric mean ratio and its 90% confidence interval falling within 80.0-125.0% for Cmax and AUC. Adverse events (AEs) were monitored throughout the trial. Sixty-one percent of the 36 randomized subjects were male, 91.7% were Caucasian, and the mean (standard deviation [SD]) age was 31.9 (7.6) years. Thirty-three (91.7%) subjects completed all 4 treatments. When taken under fed conditions, the oral solution resulted in an approximately 80% faster median tmax (0.17 vs 1.25 hours, P = .00015) and a 21% lower Cmax (mean ± SD, ng/mL: 506 ± 305 vs 835 ± 449, P = .00061) compared with the tablet. AUC values were similar between the 2 formulations. When taken under fasting conditions, the oral solution exhibited a 50% faster median tmax (0.25 vs 0.50 hours, P = .00035) to achieve a 77% higher Cmax (mean ± SD, ng/mL: 1620 ± 538 vs 1160 ± 452, P = .00032) compared with the tablet. AUCt and AUC∞ were similar between the 2 formulations. When taken under fed conditions, the oral solution resulted in a similar median tmax (0.17 vs 0.25 hours, P = .185) and 64% lower Cmax (mean ± SD, ng/mL: 506 ± 305 vs 1620 ± 538, P < .00001) compared with fasting conditions. In comparison, the tablets under fed conditions resulted in a statistically significantly delayed median tmax (1.25 vs 0.50, P = .00143) and ∼30% lower Cmax (mean ± SD, ng/mL: 835 ± 449 vs 1160 ± 452, P = .00377). AUC values were similar between fed and fasting conditions for both formulations. Twelve subjects (33%) experienced ≥1 treatment-emergent AE during the study. All AEs were mild and resolved without treatment; none resulted in study discontinuation. More treatment-emergent AEs were reported in subjects receiving the tablet compared with the solution formulation (20.0% vs 11.8 % in fasting and 17.1% vs 8.6% in fed conditions). Diclofenac potassium oral solution and tablet formulations produced statistically significantly different Cmax and tmax but similar AUC under fed and fasting conditions. Fed conditions produced significantly lower Cmax for both formulations and profoundly delayed tmax for the tablet, but had no effect on tmax for the solution formulation. These data provide insights into the importance of an earlier and greater exposure to diclofenac arising from the solution formulation than the tablet, which may account for the superiority in the onset and sustained pain reduction for the solution than the tablet formulation observed in the double-blind, efficacy/safety study in migraine patients conducted in Europe. © 2014 American Headache Society.

Towards bridging the gap between climate change projections and maize producers in South Africa

NASA Astrophysics Data System (ADS)

Landman, Willem A.; Engelbrecht, Francois; Hewitson, Bruce; Malherbe, Johan; van der Merwe, Jacobus

2018-05-01

Multi-decadal regional projections of future climate change are introduced into a linear statistical model in order to produce an ensemble of austral mid-summer maximum temperature simulations for southern Africa. The statistical model uses atmospheric thickness fields from a high-resolution (0.5° × 0.5°) reanalysis-forced simulation as predictors in order to develop a linear recalibration model which represents the relationship between atmospheric thickness fields and gridded maximum temperatures across the region. The regional climate model, the conformal-cubic atmospheric model (CCAM), projects maximum temperatures increases over southern Africa to be in the order of 4 °C under low mitigation towards the end of the century or even higher. The statistical recalibration model is able to replicate these increasing temperatures, and the atmospheric thickness-maximum temperature relationship is shown to be stable under future climate conditions. Since dry land crop yields are not explicitly simulated by climate models but are sensitive to maximum temperature extremes, the effect of projected maximum temperature change on dry land crops of the Witbank maize production district of South Africa, assuming other factors remain unchanged, is then assessed by employing a statistical approach similar to the one used for maximum temperature projections.

Statistical downscaling of CMIP5 outputs for projecting future maximum and minimum temperature over the Haihe River Bain, China

NASA Astrophysics Data System (ADS)

Yan, Tiezhu; Shen, Zhenyao; Heng, Lee; Dercon, Gerd

2016-04-01

Future climate change information is important to formulate adaptation and mitigation strategies for climate change. In this study, a statistical downscaling model (SDSM) was established using both NCEP reanalysis data and ground observations (daily maximum and minimum temperature) during the period 1971-2010, and then calibrated model was applied to generate the future maximum and minimum temperature projections using predictors from the two CMIP5 models (MPI-ESM-LR and CNRM-CM5) under two Representative Concentration Pathway (RCP2.6 and RCP8.5) during the period 2011-2100 for the Haihe River Basin, China. Compared to the baseline period, future change in annual and seasonal maximum and minimum temperature was computed after bias correction. The spatial distribution and trend change of annual maximum and minimum temperature were also analyzed using ensemble projections. The results shows that: (1)The downscaling model had a good applicability on reproducing daily and monthly mean maximum and minimum temperature over the whole basin. (2) Bias was observed when using historical predictors from CMIP5 models and the performance of CNRM-CM5 was a little worse than that of MPI-ESM-LR. (3) The change in annual mean maximum and minimum temperature under the two scenarios in 2020s, 2050s and 2070s will increase and magnitude of maximum temperature will be higher than minimum temperature. (4) The increase in temperature in the mountains and along the coastline is remarkably high than the other parts of the studies basin. (5) For annual maximum and minimum temperature, the significant upward trend will be obtained under RCP 8.5 scenario and the magnitude will be 0.37 and 0.39 ℃ per decade, respectively; the increase in magnitude under RCP 2.6 scenario will be upward in 2020s and then decrease in 2050s and 2070s, and the magnitude will be 0.01 and 0.01℃ per decade, respectively.

Distribution, richness, quality, and thermal maturity of source rock units on the North Slope of Alaska

USGS Publications Warehouse

Peters, K.E.; Bird, K.J.; Keller, M.A.; Lillis, P.G.; Magoon, L.B.

2003-01-01

Four source rock units on the North Slope were identified, characterized, and mapped to better understand the origin of petroleum in the area: Hue-gamma ray zone (Hue-GRZ), pebble shale unit, Kingak Shale, and Shublik Formation. Rock-Eval pyrolysis, total organic carbon analysis, and well logs were used to map the present-day thickness, organic quantity (TOC), quality (hydrogen index, HI), and thermal maturity (Tmax) of each unit. To map these units, we screened all available geochemical data for wells in the study area and assumed that the top and bottom of the oil window occur at Tmax of ~440° and 470°C, respectively. Based on several assumptions related to carbon mass balance and regional distributions of TOC, the present-day source rock quantity and quality maps were used to determine the extent of fractional conversion of the kerogen to petroleum and to map the original organic richness prior to thermal maturation.

Endocervical ultrasound applicator for integrated hyperthermia and HDR brachytherapy in the treatment of locally advanced cervical carcinoma.

PubMed

Wootton, Jeffery H; Hsu, I-Chow Joe; Diederich, Chris J

2011-02-01

The clinical success of hyperthermia adjunct to radiotherapy depends on adequate temperature elevation in the tumor with minimal temperature rise in organs at risk. Existing technologies for thermal treatment of the cervix have limited spatial control or rapid energy falloff. The objective of this work is to develop an endocervical applicator using a linear array of multisectored tubular ultrasound transducers to provide 3-D conformal, locally targeted hyperthermia concomitant to radiotherapy in the uterine cervix. The catheter-based device is integrated within a HDR brachytherapy applicator to facilitate sequential and potentially simultaneous heat and radiation delivery. Treatment planning images from 35 patients who underwent HDR brachytherapy for locally advanced cervical cancer were inspected to assess the dimensions of radiation clinical target volumes (CTVs) and gross tumor volumes (GTVs) surrounding the cervix and the proximity of organs at risk. Biothermal simulation was used to identify applicator and catheter material parameters to adequately heat the cervix with minimal thermal dose accumulation in nontargeted structures. A family of ultrasound applicators was fabricated with two to three tubular transducers operating at 6.6-7.4 MHz that are unsectored (360 degrees), bisectored (2 x 180 degrees), or trisectored (3 x 120 degrees) for control of energy deposition in angle and along the device length in order to satisfy anatomical constraints. The device is housed in a 6 mm diameter PET catheter with cooling water flow for endocervical implantation. Devices were characterized by measuring acoustic efficiencies, rotational acoustic intensity distributions, and rotational temperature distributions in phantom. The CTV in HDR brachytherapy plans extends 20.5 +/- 5.0 mm from the endocervical tandem with the rectum and bladder typically <8 mm from the target boundary. The GTV extends 19.4 +/- 7.3 mm from the tandem. Simulations indicate that for 60 min treatments the applicator can heat to 41 degrees C and deliver > 5EM(43 degrees C) over 4-5 cm diameter with Tmax < 45 degrees C and 1 kg m(-3) s(-1) blood perfusion. The 41 degrees C contour diameter is reduced to 3-4 cm at 3 kg m(-3) s(-1) perfusion. Differential power control to transducer elements and sectors demonstrates tailoring of heating along the device length and in angle. Sector cuts are associated with a 14-47 degrees acoustic dead zone, depending on cut width, resulting in a approximately 2-4 degrees C temperature reduction within the dead zone below Tmax. Dead zones can be oriented for thermal protection of the rectum and bladder. Fabricated devices have acoustic efficiencies of 33.4%-51.8% with acoustic output that is well collimated in length, reflects the sectoring strategy, and is strongly correlated with temperature distributions. A catheter-based ultrasound applicator was developed for endocervical implantation with locally targeted, 3-D conformal thermal delivery to the uterine cervix. Feasibility of heating clinically relevant target volumes was demonstrated with power control along the device length and in angle to treat the cervix with minimal thermal dose delivery to the rectum and bladder.

Changes in ambient temperature differentially alter the thermoregulatory, cardiac and locomotor stimulant effects of 4-methylmethcathinone (mephedrone).

PubMed

Miller, M L; Creehan, K M; Angrish, D; Barlow, D J; Houseknecht, K L; Dickerson, T J; Taffe, M A

2013-01-01

The substituted cathinone compound known as mephedrone (4-methylmethcathinone; 4-MMC) has become popular with recreational users of psychomotor-stimulant compounds. Only recently have the first preclinical studies provided information about this drug in the scientific literature; nevertheless, media reports have led to drug control actions in the UK and across several US states. Rodent studies indicate that 4-MMC exhibits neuropharmacological similarity to 3,4-methylenedioxymethamphetamine (MDMA) and prompt investigation of the thermoregulatory, cardiac and locomotor effects of 4-MMC. This study focuses on the role of ambient temperature, which has been shown to shift the effects of MDMA from hyperthermic to hypothermic. Male Sprague-Dawley rats were monitored after subcutaneous administration of 4-MMC (1.0-5.6 mg/kg) using an implantable radiotelemetry system under conditions of low (20 °C) and high (30 °C) ambient temperature. A pharmacokinetic study found a T(max) of 0.25 h and a C(max) of 1206 ng/ml after 5.6 mg/kg 4-MMC. A dose-dependent reduction of body temperature was produced by 4-MMC at 20 °C but there was no temperature change at 30 °C. Increased locomotor activity was observed after 4-MMC administration under both ambient temperatures, however, significantly more activity was observed at 30 °C. Heart rate was slowed by 1.0 and 5.6 mg/kg 4-MMC at 20°C, and was slower in the 30 °C vs. 20 °C condition across all treatments. These results show that the cathinone analog 4-MMC exhibits in vivo thermoregulatory properties that are distinct from those produced by MDMA. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Stochastic modelling of the monthly average maximum and minimum temperature patterns in India 1981-2015

NASA Astrophysics Data System (ADS)

Narasimha Murthy, K. V.; Saravana, R.; Vijaya Kumar, K.

2018-04-01

The paper investigates the stochastic modelling and forecasting of monthly average maximum and minimum temperature patterns through suitable seasonal auto regressive integrated moving average (SARIMA) model for the period 1981-2015 in India. The variations and distributions of monthly maximum and minimum temperatures are analyzed through Box plots and cumulative distribution functions. The time series plot indicates that the maximum temperature series contain sharp peaks in almost all the years, while it is not true for the minimum temperature series, so both the series are modelled separately. The possible SARIMA model has been chosen based on observing autocorrelation function (ACF), partial autocorrelation function (PACF), and inverse autocorrelation function (IACF) of the logarithmic transformed temperature series. The SARIMA (1, 0, 0) × (0, 1, 1)12 model is selected for monthly average maximum and minimum temperature series based on minimum Bayesian information criteria. The model parameters are obtained using maximum-likelihood method with the help of standard error of residuals. The adequacy of the selected model is determined using correlation diagnostic checking through ACF, PACF, IACF, and p values of Ljung-Box test statistic of residuals and using normal diagnostic checking through the kernel and normal density curves of histogram and Q-Q plot. Finally, the forecasting of monthly maximum and minimum temperature patterns of India for the next 3 years has been noticed with the help of selected model.

Estimating missing daily temperature extremes in Jaffna, Sri Lanka

NASA Astrophysics Data System (ADS)

Thevakaran, A.; Sonnadara, D. U. J.

2018-04-01

The accuracy of reconstructing missing daily temperature extremes in the Jaffna climatological station, situated in the northern part of the dry zone of Sri Lanka, is presented. The adopted method utilizes standard departures of daily maximum and minimum temperature values at four neighbouring stations, Mannar, Anuradhapura, Puttalam and Trincomalee to estimate the standard departures of daily maximum and minimum temperatures at the target station, Jaffna. The daily maximum and minimum temperatures from 1966 to 1980 (15 years) were used to test the validity of the method. The accuracy of the estimation is higher for daily maximum temperature compared to daily minimum temperature. About 95% of the estimated daily maximum temperatures are within ±1.5 °C of the observed values. For daily minimum temperature, the percentage is about 92. By calculating the standard deviation of the difference in estimated and observed values, we have shown that the error in estimating the daily maximum and minimum temperatures is ±0.7 and ±0.9 °C, respectively. To obtain the best accuracy when estimating the missing daily temperature extremes, it is important to include Mannar which is the nearest station to the target station, Jaffna. We conclude from the analysis that the method can be applied successfully to reconstruct the missing daily temperature extremes in Jaffna where no data is available due to frequent disruptions caused by civil unrests and hostilities in the region during the period, 1984 to 2000.

40 CFR Table 4 to Subpart Ooo of... - Operating Parameter Levels

Code of Federal Regulations, 2012 CFR

2012-07-01

... temperature Maximum temperature Carbon absorber Total regeneration steam or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum flow or pressure; and maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

14 CFR 29.1521 - Powerplant limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... pressure (for reciprocating engines); (3) The maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (4) The maximum allowable power or torque for each engine, considering the... maximum allowable turbine inlet or turbine outlet gas temperature (for turbine engines); (5) The maximum...

On the Trend of the Annual Mean, Maximum, and Minimum Temperature and the Diurnal Temperature Range in the Armagh Observatory, Northern Ireland, Dataset, 1844 -2012

NASA Technical Reports Server (NTRS)

Wilson, Robert M.

2013-01-01

Examined are the annual averages, 10-year moving averages, decadal averages, and sunspot cycle (SC) length averages of the mean, maximum, and minimum surface air temperatures and the diurnal temperature range (DTR) for the Armagh Observatory, Northern Ireland, during the interval 1844-2012. Strong upward trends are apparent in the Armagh surface-air temperatures (ASAT), while a strong downward trend is apparent in the DTR, especially when the ASAT data are averaged by decade or over individual SC lengths. The long-term decrease in the decadaland SC-averaged annual DTR occurs because the annual minimum temperatures have risen more quickly than the annual maximum temperatures. Estimates are given for the Armagh annual mean, maximum, and minimum temperatures and the DTR for the current decade (2010-2019) and SC24.

Exhaust-Gas Pressure and Temperature Survey of F404-GE-400 Turbofan Engine

NASA Technical Reports Server (NTRS)

Walton, James T.; Burcham, Frank W., Jr.

1986-01-01

An exhaust-gas pressure and temperature survey of the General Electric F404-GE-400 turbofan engine was conducted in the altitude test facility of the NASA Lewis Propulsion System Laboratory. Traversals by a survey rake were made across the exhaust-nozzle exit to measure the pitot pressure and total temperature. Tests were performed at Mach 0.87 and a 24,000-ft altitude and at Mach 0.30 and a 30,000-ft altitude with various power settings from intermediate to maximum afterburning. Data yielded smooth pressure and temperature profiles with maximum jet temperatures approximately 1.4 in. inside the nozzle edge and maximum jet temperatures from 1 to 3 in. inside the edge. A low-pressure region located exactly at engine center was noted. The maximum temperature encountered was 3800 R.

[Determination of plasma concentration of quercetin, kaempferid and isorhamnetin in Hippophae rhamnoides extract by HPLC-MS/MS and pharmacokinetics in rats].

PubMed

Liu, Yu; Yang, Juan; Tuo, Yang-ling; Wei, Ting; Zeng, Yong; Wang, Ping; Meng, Xian-li

2015-10-01

To establish an HPLC-MS/MS method for the analysis of quercetin, kaempferid and isorhamnetin in rats plasma and study its pharmamacokinetics after an intragastrical administration of Hippophae rhamnoides extracts. Five healthy male Sprague-Dawley (SD) rats were given single doses of H. rhamnoides extracts (quercetin 26.35 mg x kg(-1), kaempferid 4.040 mg x kg(-1), isorhamnetin 31.37 mg x kg(-1)), and then their orbital sinus blood samples were collected at different time points. The drug plasma concentration of the three flavonoids was determined by HPLC-MS/MS method. After that, the main pharmacokinetics parameters were calculated by using Kinetica 5. 0. 11 software. The methodological test showed that the linear concentration ranges of quercetin, kaempferid and isorhamnetin were 7.500-600.0 μg x L(-1) (R2 = 0.998 5), 1.000-80.00 μg x L(-1) (R2 = 0.998 5 ) and 10.00-800.0 μg x L(-1) (R2 = 0.998 0), respectively. The inner and inter-days precisions were both less than 14.0%. The plasma samples showed a good stability and consistency with the requirement of biological sample analysis after the samples were frozen once and placed at - 20 degrees C for 15 d and room temperature for 6 h and the treated analytes were placed at -20 degrees C for 24 h. For quercetin, the pharmacokinetic parameter t(½β), AUC(0-∞), MRT(0.∞), C.(max) and T(max) were (113.3 ± 19.37) min, (12 542.14 ± 3 504.05) μg x h x L(-1), (119.6 ± 13.29) h, (164.6 ± 27.33) μg x L(-1) and (5.199 ± 0.840 3) h, respectively. For kaempferid, the pharmacokinetic parameters t(½β), AUC(0-t), MRT(0-∞), C(max) and T(max) were (79.85 ± 17.15) min, (934.51 ± 94.59) μg x h x L(-1), (81.50 ± 13.75) h, (80.15 ± 14.24) μg x L(-1) and (3.827 ± 0.902 7) h, respectively. For isorhamnetin, the pharmacokinetic parameters t1,2,, AUC(0-t), MRT(0-∞), C(max) and T(max) were (118.3 ± 20.73) min, (26 067.77 ± 4 124.60) μg x h x L(-1), (129.0 ± 16.30) h, (269.6 ± 29.32) μg x L(-1) and (6.513 ± 1.450) h, respectively. The HPLC-MS/MS analysis method established in this study was proved to be sensitive and accurate and could be applied in the pharmacokinetic study of quercetin, kaempferid and isorhamnetin in rat plasma.

Elevating bioavailability of curcumin via encapsulation with a novel formulation of artificial oil bodies.

PubMed

Chang, Ming-Tsung; Tsai, Tong-Rong; Lee, Chun-Yann; Wei, Yu-Sheng; Chen, Ying-Jie; Chen, Chun-Ren; Tzen, Jason T C

2013-10-09

Utilization of curcumin has been limited due to its poor oral bioavailability. Oral bioavailability of hydrophobic compounds might be elevated via encapsulation in artificial seed oil bodies. This study aimed to improve oral bioavailability of curcumin via this encapsulation. Unfortunately, curcumin was indissoluble in various seed oils. A mixed dissolvent formula was used to dissolve curcumin, and the admixture was successfully encapsulated in artificial oil bodies stabilized by recombinant sesame caleosin. The artificial oil bodies of relatively small sizes (150 nm) were stably solidified in the forms of powder and tablet. Oral bioavailability of curcumin with or without encapsulation in artificial oil bodies was assessed in Sprague-Dawley male rats. The results showed that encapsulation of curcumin significantly elevated its bioavailability and provided the highest maximum whole blood concentration (Cmax), 37 ± 28 ng/mL, in the experimental animals 45 ± 17 min (t(max)) after oral administration. Relative bioavailability calculated on the basis of the area under the plasma concentration-time curve (AUC) was increased by 47.7 times when curcumin was encapsulated in the artificial oil bodies. This novel formulation of artificial oil bodies seems to possess great potential to encapsulate hydrophobic drugs for oral administration.

Do dual-thread orthodontic mini-implants improve bone/tissue mechanical retention?

PubMed

Lin, Yang-Sung; Chang, Yau-Zen; Yu, Jian-Hong; Lin, Chun-Li

2014-12-01

The aim of this study was to understand whether the pitch relationship between micro and macro thread designs with a parametrical relationship in a dual-thread mini-implant can improve primary stability. Three types of mini-implants consisting of single-thread (ST) (0.75 mm pitch in whole length), dual-thread A (DTA) with double-start 0.375 mm pitch, and dual-thread B (DTB) with single-start 0.2 mm pitch in upper 2-mm micro thread region for performing insertion and pull-out testing. Histomorphometric analysis was performed in these specimens in evaluating peri-implant bone defects using a non-contact vision measuring system. The maximum inserted torque (Tmax) in type DTA was found to be the smallest significantly, but corresponding values found no significant difference between ST and DTB. The largest pull-out strength (Fmax) in the DTA mini-implant was found significantly greater than that for the ST mini-implant regardless of implant insertion orientation. Mini-implant engaged the cortical bone well as observed in ST and DTA types. Dual-thread mini-implant with correct micro thread pitch (parametrical relationship with macro thread pitch) in the cortical bone region can improve primary stability and enhanced mechanical retention.

Polymeric nanoparticles for increased oral bioavailability and rapid absorption using celecoxib as a model of a low-solubility, high-permeability drug.

PubMed

Morgen, Michael; Bloom, Corey; Beyerinck, Ron; Bello, Akintunde; Song, Wei; Wilkinson, Karen; Steenwyk, Rick; Shamblin, Sheri

2012-02-01

To demonstrate drug/polymer nanoparticles can increase the rate and extent of oral absorption of a low-solubility, high-permeability drug. Amorphous drug/polymer nanoparticles containing celecoxib were prepared using ethyl cellulose and either sodium caseinate or bile salt. Nanoparticles were characterized using dynamic light scattering, transmission and scanning electron microscopy, and differential scanning calorimetry. Drug release and resuspension studies were performed using high-performance liquid chromatography. Pharmacokinetic studies were performed in dogs and humans. A physical model is presented describing the nanoparticle state of matter and release performance. Nanoparticles dosed orally in aqueous suspensions provided higher systemic exposure and faster attainment of peak plasma concentrations than commercial capsules, with median time to maximum drug concentration (Tmax) of 0.75 h in humans for nanoparticles vs. 3 h for commercial capsules. Nanoparticles released celecoxib rapidly and provided higher dissolved-drug concentrations than micronized crystalline drug. Nanoparticle suspensions are stable for several days and can be spray-dried to form dry powders that resuspend in water. Drug/polymer nanoparticles are well suited for providing rapid oral absorption and increased bioavailability of BCS Class II drugs.

Blending of palm oil, palm stearin and palm kernel oil in the preparation of table and pastry margarine.

PubMed

Norlida, H M; Md Ali, A R; Muhadhir, I

1996-01-01

Palm oil (PO ; iodin value = 52), palm stearin (POs1; i.v. = 32 and POs2; i.v. = 40) and palm kernel oil (PKO; i.v. = 17) were blended in ternary systems. The blends were then studied for their physical properties such as melting point (m.p.), solid fat content (SFC), and cooling curve. Results showed that palm stearin increased the blends melting point while palm kernel oil reduced it. To produce table margarine with melting point (m.p.) below 40 degrees C, the POs1 should be added at level of < or = 16%, while POs2 at level of < or = 20%. At 10 degrees C, eutectic interaction occur between PO and PKO which reach their maximum at about 60:40 blending ratio. Within the eutectic region, to maintain the SFC at 10 degrees C to be < or = 50%, POs1 may be added at level of < or = 7%, while POs2 at level of < or = 12%. The addition of palm stearin increased the blends solidification Tmin and Tmax values, while PKO reduced them. Blends which contained high amount of palm stearin showed melting point and cooling curves quite similar to that of pastry margarine.

Attributing anthropogenic impact on regional heat wave events using CAM5 model large ensemble simulations

NASA Astrophysics Data System (ADS)

Lo, S. H.; Chen, C. T.

2017-12-01

Extreme heat waves have serious impacts on society. It was argued that the anthropogenic forcing might substantially increase the risk of extreme heat wave events (e.g. over western Europe in 2003 and over Russia in 2010). However, the regional dependence of such anthropogenic impact and the sensitivity of the attributed risk to the definition of heat wave still require further studies. In our research framework, the change in the frequency and severity of a heat wave event under current conditions is calculated and compared with the probability and magnitude of the event if the effects of particular external forcing, such as due to human influence, had been absent. In our research, we use the CAM5 large ensemble simulation from the CLIVAR C20C+ Detection and Attribution project (http://portal.nersc.gov/c20c/main.html, Folland et al. 2014) to detect the heat wave events occurred in both historical all forcing run and natural forcing only run. The heat wave events are identified by partial duration series method (Huth et al., 2000). We test the sensitivity of heat wave thresholds from daily maximum temperature (Tmax) in warm season (from May to September) between 1959 and 2013. We consider the anthropogenic effect on the later period (2000-2013) when the warming due to human impact is more evident. Using Taiwan and surrounding area as our preliminary research target, We found the anthropogenic effect will increase the heat wave day per year from 30 days to 75 days and make the mean starting(ending) day for heat waves events about 15-30 days earlier(later). Using the Fraction of Attribution Risk analysis to estimate the risk of frequency of heat wave day, our results show the anthropogenic forcing very likely increase the heat wave days over Taiwan by more than 50%. Further regional differences and sensitivity of the attributed risk to the definition of heat wave will be compared and discussed.

Effects of radiofrequency probe application on irrigation fluid temperature in the wrist joint.

PubMed

Sotereanos, Dean G; Darlis, Nickolaos A; Kokkalis, Zinon T; Zanaros, George; Altman, Gregory T; Miller, Mark Carl

2009-12-01

Radiofrequency (RF) probes used in wrist arthroscopy may raise joint fluid temperature, increasing the risk of capsular and ligamentous damage. The purposes of the current study were to measure joint fluid temperature during wrist arthroscopy with the use of RF probes, and to determine whether using an outlet portal will reduce the maximum temperature. We performed wrist arthroscopy on 8 cadaveric arms. Ablation and coagulation cycles using RF probe were performed at documented locations within the joint. This was done for 60-second intervals on both the radial and ulnar side of the wrist, to mimic clinical practice. We used 4 fiberoptic phosphorescent probes to measure temperature (radial, ulnar, inflow-tube, and outflow-tube probes) and measured joint fluid temperature with and without outflow. There was a significant difference between wrists with and without outflow when examining maximum ablation temperatures (p < .002). All specimens showed higher maximum and average ablation temperatures without outflow. Maximum joint temperatures, greater than 60 degrees C, were observed in only no-outflow conditions. In performing RF ablation during wrist arthroscopy, the use of an outlet portal reduces the joint fluid temperature. Without an outlet portal, maximum temperatures can exceed desirable levels when using ablation; such temperatures have the potential to damage adjacent tissues. It is useful to maintain adequate outflow when using the radiofrequency probes during wrist arthroscopy.

Soil and air temperatures for different habitats in Mount Rainier National Park.

Treesearch

Sarah E. Greene; Mark Klopsch

1985-01-01

This paper reports air and soil temperature data from 10 sites in Mount Rainier National Park in Washington State for 2- to 5-year periods. Data provided are monthly summaries for day and night mean air temperatures, mean minimum and maximum air temperatures, absolute minimum and maximum air temperatures, range of air temperatures, mean soil temperature, and absolute...

Heterogeneous brittle-ductile deformation at shallow crustal levels under high thermal conditions: The case of a synkinematic contact aureole in the inner northern Apennines, southeastern Elba Island, Italy

NASA Astrophysics Data System (ADS)

Papeschi, Samuele; Musumeci, Giovanni; Mazzarini, Francesco

2017-10-01

We present an example of interaction between magmatism and tectonics at shallow crustal levels. In the Late Miocene the metamorphic units of the eastern Elba Island (northern Apennines) were intruded at very shallow crustal levels by a large pluton (> 60 km2) with the development of an hectometre-sized contact aureole defined by growth of low-pressure/high-temperature mineral assemblages (Pmax < 0.2 GPa, Tmax 650 °C). Structural data show that the contact aureole is associated with a km-sized antiform of the foliation and by several metre- to decametre-thick high-strain domains consisting of strongly foliated rocks containing synkinematic HT/LP mineral assemblages and ductile shear zones of variable thickness. These shear zones are characterized by a mylonitic foliation variably overprinted by cataclasis. Quartz microfabrics indicate that the dynamic crystallization processes progressively changed from grain boundary migration, associated with the thermal peak of contact metamorphism, to subgrain rotation and bulging recrystallization, the latter mostly associated with the cataclastic overprint. These transitions of recrystallization mechanisms in quartz are related to a progressive decrease of temperature during deformation. Deformation accompanied the development and cooling of the contact aureole, which recorded the switch from high temperature ductile to low temperature brittle conditions. The geometry of the studied deformation structures is consistent with the constraints of the regional tectonic evolution and its local interaction with the localized and transient thermal anomaly related to the coeval emplacement of igneous rocks.

Do Mitochondria Limit Hot Fish Hearts? Understanding the Role of Mitochondrial Function with Heat Stress in Notolabrus celidotus

PubMed Central

Iftikar, Fathima I.; Hickey, Anthony J. R.

2013-01-01

Hearts are the first organs to fail in animals exposed to heat stress. Predictions of climate change mediated increases in ocean temperatures suggest that the ectothermic heart may place tight constraints on the diversity and distribution of marine species with cardiovascular systems. For many such species, their upper temperature limits (Tmax) and respective heart failure (HF) temperature (THF) are only a few degrees from current environmental temperatures. While the ectothermic cardiovascular system acts as an “ecological thermometer,” the exact mechanism that mediates HF remains unresolved. We propose that heat-stressed cardiac mitochondria drive HF. Using a common New Zealand fish, Notolabrus celidotus, we determined the THF (27.5°C). Haemoglobin oxygen saturation appeared to be unaltered in the blood surrounding and within heat stressed hearts. Using high resolution respirometry coupled to fluorimeters, we explored temperature-mediated changes in respiration, ROS and ATP production, and overlaid these changes with THF. Even at saturating oxygen levels several mitochondrial components were compromised before THF. Importantly, the capacity to efficiently produce ATP in the heart is limited at 25°C, and this is prior to the acute THF for N. celidotus. Membrane leakiness increased significantly at 25°C, as did cytochrome c release and permeability to NADH. Maximal flux rates and the capacity for the electron transport system to uncouple were also altered at 25°C. These data indicate that mitochondrial membrane integrity is lost, depressing ATP synthesis capacity and promoting cytochrome c release, prior to THF. Mitochondria can mediate HF in heat stressed hearts in fish and play a significant role in thermal stress tolerance, and perhaps limit species distributions by contributing to HF. PMID:23724026

Do mitochondria limit hot fish hearts? Understanding the role of mitochondrial function with heat stress in Notolabrus celidotus.

PubMed

Iftikar, Fathima I; Hickey, Anthony J R

2013-01-01

Hearts are the first organs to fail in animals exposed to heat stress. Predictions of climate change mediated increases in ocean temperatures suggest that the ectothermic heart may place tight constraints on the diversity and distribution of marine species with cardiovascular systems. For many such species, their upper temperature limits (Tmax) and respective heart failure (HF) temperature (T(HF)) are only a few degrees from current environmental temperatures. While the ectothermic cardiovascular system acts as an "ecological thermometer," the exact mechanism that mediates HF remains unresolved. We propose that heat-stressed cardiac mitochondria drive HF. Using a common New Zealand fish, Notolabrus celidotus, we determined the THF (27.5°C). Haemoglobin oxygen saturation appeared to be unaltered in the blood surrounding and within heat stressed hearts. Using high resolution respirometry coupled to fluorimeters, we explored temperature-mediated changes in respiration, ROS and ATP production, and overlaid these changes with T(HF). Even at saturating oxygen levels several mitochondrial components were compromised before T(HF). Importantly, the capacity to efficiently produce ATP in the heart is limited at 25°C, and this is prior to the acute T(HF) for N. celidotus. Membrane leakiness increased significantly at 25°C, as did cytochrome c release and permeability to NADH. Maximal flux rates and the capacity for the electron transport system to uncouple were also altered at 25°C. These data indicate that mitochondrial membrane integrity is lost, depressing ATP synthesis capacity and promoting cytochrome c release, prior to T(HF). Mitochondria can mediate HF in heat stressed hearts in fish and play a significant role in thermal stress tolerance, and perhaps limit species distributions by contributing to HF.

Could thermal sensitivity of mitochondria determine species distribution in a changing climate?

PubMed

Iftikar, Fathima I; MacDonald, Julia R; Baker, Daniel W; Renshaw, Gillian M C; Hickey, Anthony J R

2014-07-01

For many aquatic species, the upper thermal limit (Tmax) and the heart failure temperature (THF) are only a few degrees away from the species' current environmental temperatures. While the mechanisms mediating temperature-induced heart failure (HF) remain unresolved, energy flow and/or oxygen supply disruptions to cardiac mitochondria may be impacted by heat stress. Recent work using a New Zealand wrasse (Notolabrus celidotus) found that ATP synthesis capacity of cardiac mitochondria collapses prior to T(HF). However, whether this effect is limited to one species from one thermal habitat remains unknown. The present study confirmed that cardiac mitochondrial dysfunction contributes to heat stress-induced HF in two additional wrasses that occupy cold temperate (Notolabrus fucicola) and tropical (Thalassoma lunare) habitats. With exposure to heat stress, T. lunare had the least scope to maintain heart function with increasing temperature. Heat-exposed fish of all species showed elevated plasma succinate, and the heart mitochondria from the cold temperate N. fucicola showed decreased phosphorylation efficiencies (depressed respiratory control ratio, RCR), cytochrome c oxidase (CCO) flux and electron transport system (ETS) flux. In situ assays conducted across a range of temperatures using naive tissues showed depressed complex II (CII) and CCO capacity, limited ETS reserve capacities and lowered efficiencies of pyruvate uptake in T. lunare and N. celidotus. Notably, alterations of mitochondrial function were detectable at saturating oxygen levels, indicating that cardiac mitochondrial insufficiency can occur prior to HF without oxygen limitation. Our data support the view that species distribution may be related to the thermal limits of mitochondrial stability and function, which will be important as oceans continue to warm. © 2014. Published by The Company of Biologists Ltd.

Equatorial temperature anomaly during solar minimum

NASA Astrophysics Data System (ADS)

Suhasini, R.; Raghavarao, R.; Mayr, H. G.; Hoegy, W. R.; Wharton, L. E.

2001-11-01

We show evidence for the occurrence of the equatorial temperature anomaly (ETA) during solar minimum by analyzing the temperature and total ion density data from the Neutral Atmosphere Temperature Experiment (NATE) and the Cylindrical Electrostatic Probe (CEP), respectively, on board the Atmospheric Explorer-E satellite. The chosen data refer to a height of ~254 km in the African and Asian longitude sector (340.1°E-200°E) during a summer season in the Southern Hemisphere. As during the solar maximum period, the spatial characteristics of the ETA are similar to those of the equatorial ionization anomaly (EIA). A minimum in the gas temperature is collocated with the minimum in the ion density at the dip equator, and a temperature maximum on the south side of the equator is collocated with the density maximum of the EIA. The daytime behavior of ETA formation is about the same as that of EIA as both of them are clearly present at around 1300 and 1400 local solar time (LST) only. At 1400 LST the difference between the temperatures at the crest and the trough (ETA strength) reaches a maximum value of about 100°K which is ~14% of the temperature at the trough. Like the EIA, the ETA also suddenly disappears after 1400 LST. Thus the EIA appears to be a prerequisite for the ETA formation. During the premidnight time (2200 LST), however, while the EIA is nonexistent, the temperature distribution forms a pattern opposite to that at 1400 LST in the daytime. It shows a maximum around the dip equator and a broad minimum at the daytime crest region where the postsunset cooling also is faster and occurs earlier than at the dip equator. This nighttime maximum appears to be related to the signature of the midnight temperature maximum (MTM). Mass Spectrometer Incoherent Scatter (MSIS) model temperatures, in general, are higher than the observed average temperatures for the summer season and in particular for the region around the dip equator around noon hours.

The coronal structure of active regions

NASA Technical Reports Server (NTRS)

Landini, M.; Monsignori Fossi, B. C.; Krieger, A.; Vaiana, G. S.

1975-01-01

A four-parameter model, which assumes a Gaussian dependence of both temperature and pressure on distance from center, is used to fit the compact part of coronal active regions as observed in X-ray photographs from a rocket experiment. The four parameters are the maximum temperature, the maximum pressure, the width of the pressure distribution, and the width of the temperature distribution. The maximum temperature ranges from 2.2 to 2.8 million K, and the maximum density from 2 to 9 by 10 to the 9th power per cu cm. The range of the pressure-distribution width is from 2 to 4 by 10 to the 9th power cm and that of the temperature-distribution width from 2 to 7.

Changes in minimum and maximum temperatures at the Pic du Midi in relation with humidity and cloudiness, 1882-1984

NASA Astrophysics Data System (ADS)

Dessens, J.; Bücher, A.

In an attempt to contribute to the investigation on a global climate change, a historical series of minimum and maximum temperature data at the Pic du Midi, a mountain observatory at 2862 m a.s.l. in the French Pyrenees, is updated after correction of a systematic deviation due to a relocation of the station in 1971. These data, which now cover the 1882-1984 period, are examined in parallel with humidity and cloud cover data for the same period. From the beginning to the end of this period, observations show that the mean night-time temperature has increased by 2.39° C/100 yr while the mean daytime temperature has decreased by 0.50° C/100 yr. In consequence, the mean annual diurnal temperature range has dropped by 36%/100 yr. The maximum seasonal decrease is 46%/100 yr in spring. Season-to-season and year-to-year inter-relationships between minimum temperature, maximum temperature, relative humidity and cloud cover suggest that the decrease in maximum temperature is related to a concomitant increase of 15%/100 yr in both relative humidity and cloud cover.

Physicochemical characterization and in vivo evaluation of thermosensitive diclofenac liquid suppository.

PubMed

Yong, Chul Soon; Choi, Young-Kwon; Kim, Yong-Il; Park, Byung-Joo; Quan, Qi-Zhe; Rhee, Jong-Dal; Kim, Chong-Kook; Choi, Han-Gon

2003-02-01

Liquid suppository systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and mucoadhesive to the rectal tissues without leakage after the dose. However, a liquid suppository containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a liquid suppository system using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers and sodium chloride were investigated. Furthermore, the pharmacokinetic study of diclofenac sodium delivered by the liquid suppository was performed. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. The liquid suppositories with less than 1.0% of sodium chloride, in which the drug was not precipitated, were inserted into the rectum without difficulty and leakage. Furthermore, liquid suppository gave significantly higher initial plasma concentrations and faster Tmax of diclofenac sodium than did solid suppository, indicating that drug from liquid suppository could be absorbed faster than that from solid one in rats. Our results suggested that a thermosensitive liquid suppository system with sodium chloride and poloxamers was a more physically stable, convenient and effective rectal dosage form for diclofenac sodium.

Increases in maximum stream temperatures after slash burning in a small experimental watershed.

Treesearch

Al Levno; Jack Rothacher

1969-01-01

The first year after slash was burned on a 237-acre clearcut watershed in the Cascade Range of Oregon, average maximum water temperatures increased 13°, 14°, and 12°F, during June, July, and August. A maximum stream temperature of 75°F. persisted for 3 hours on a day in July.

Determination of the Maximum Temperature in a Non-Uniform Hot Zone by Line-of-Site Absorption Spectroscopy with a Single Diode Laser.

PubMed

Liger, Vladimir V; Mironenko, Vladimir R; Kuritsyn, Yurii A; Bolshov, Mikhail A

2018-05-17

A new algorithm for the estimation of the maximum temperature in a non-uniform hot zone by a sensor based on absorption spectrometry with a diode laser is developed. The algorithm is based on the fitting of the absorption spectrum with a test molecule in a non-uniform zone by linear combination of two single temperature spectra simulated using spectroscopic databases. The proposed algorithm allows one to better estimate the maximum temperature of a non-uniform zone and can be useful if only the maximum temperature rather than a precise temperature profile is of primary interest. The efficiency and specificity of the algorithm are demonstrated in numerical experiments and experimentally proven using an optical cell with two sections. Temperatures and water vapor concentrations could be independently regulated in both sections. The best fitting was found using a correlation technique. A distributed feedback (DFB) diode laser in the spectral range around 1.343 µm was used in the experiments. Because of the significant differences between the temperature dependences of the experimental and theoretical absorption spectra in the temperature range 300⁻1200 K, a database was constructed using experimentally detected single temperature spectra. Using the developed algorithm the maximum temperature in the two-section cell was estimated with accuracy better than 30 K.

Estimation of Surface Air Temperature from MODIS 1km Resolution Land Surface Temperature Over Northern China

NASA Technical Reports Server (NTRS)

Shen, Suhung; Leptoukh, Gregory G.; Gerasimov, Irina

2010-01-01

Surface air temperature is a critical variable to describe the energy and water cycle of the Earth-atmosphere system and is a key input element for hydrology and land surface models. It is a very important variable in agricultural applications and climate change studies. This is a preliminary study to examine statistical relationships between ground meteorological station measured surface daily maximum/minimum air temperature and satellite remotely sensed land surface temperature from MODIS over the dry and semiarid regions of northern China. Studies were conducted for both MODIS-Terra and MODIS-Aqua by using year 2009 data. Results indicate that the relationships between surface air temperature and remotely sensed land surface temperature are statistically significant. The relationships between the maximum air temperature and daytime land surface temperature depends significantly on land surface types and vegetation index, but the minimum air temperature and nighttime land surface temperature has little dependence on the surface conditions. Based on linear regression relationship between surface air temperature and MODIS land surface temperature, surface maximum and minimum air temperatures are estimated from 1km MODIS land surface temperature under clear sky conditions. The statistical errors (sigma) of the estimated daily maximum (minimum) air temperature is about 3.8 C(3.7 C).

Pharmacokinetics and pharmacodynamics of edivoxetine (LY2216684), a norepinephrine reuptake inhibitor, in pediatric patients with attention-deficit/hyperactivity disorder.

PubMed

Kielbasa, William; Quinlan, Tonya; Jin, Ling; Xu, Wen; Lachno, D Richard; Dean, Robert A; Allen, Albert J

2012-08-01

Edivoxetine (LY2216684) is a selective and potent norepinephrine reuptake inhibitor (NERI). The pharmacokinetics (PK) and pharmacodynamics (PD) of edivoxetine were assessed in children and adolescent patients with attention-deficit/hyperactivity disorder (ADHD) following single and once-daily oral doses of edivoxetine. During a phase 1 open-label safety, tolerability, and PK study, pediatric patients were administered edivoxetine at target doses of 0.05, 0.1, 0.2 and 0.3 mg/kg, and blood samples were collected to determine plasma concentrations of edivoxetine for PK assessments and plasma 3,4-dihydroxyphenylglycol (DHPG) concentrations for PD assessments. Edivoxetine plasma concentrations were measured using liquid chromatography with tandem mass spectrometric detection, and DHPG was measured using liquid chromatography with electrochemical detection. Edivoxetine PK was comparable between children and adolescents. The time to maximum concentration (t(max)) of edivoxetine was ∼2 hours, which was followed by a mono-exponential decline in plasma concentrations with a terminal elimination half-life (t(1/2)) of ∼6 hours. Dose-dependent increases in area under the edivoxetine plasma concentration versus time curve from zero to infinity (AUC(0-∞)) and maximum plasma concentration (C(max)) were observed, and there was no discernable difference in the apparent clearance (CL/F) or the apparent volume of distribution at steady state (V(ss)/F) across the dose range. In adolescents, edivoxetine caused a maximum decrease in plasma DHPG concentrations from baseline of ∼28%, most notably within 8 hours of edivoxetine administration. This initial study in pediatric patients with ADHD provides new information on the PK profile of edivoxetine, and exposures that decrease plasma DHPG consistent with the mechanism of action of a NERI. The PK and PD data inform edivoxetine pharmacology and can be used to develop comprehensive population PK and/or PK-PD models to guide dosing strategies.

Lacosamide cardiac safety: a thorough QT/QTc trial in healthy volunteers.

PubMed

Kropeit, D; Johnson, M; Cawello, W; Rudd, G D; Horstmann, R

2015-11-01

To determine whether lacosamide prolongs the corrected QT interval (QTc). In this randomized, double-blind, positive- and placebo-controlled, parallel-design trial, healthy volunteers were randomized to lacosamide 400 mg/day (maximum-recommended daily dose, 6 days), lacosamide 800 mg/day (supratherapeutic dose, 6 days), placebo (6 days), or moxifloxacin 400 mg/day (3 days). Variables included maximum time-matched change from baseline in QT interval individually corrected for heart rate ([HR] QTcI), other ECG parameters, pharmacokinetics (PK), and safety/tolerability. The QTcI mean maximum difference from placebo was -4.3 ms and -6.3 ms for lacosamide 400 and 800 mg/day; upper limits of the 2-sided 90% confidence interval were below the 10 ms non-inferiority margin (-0.5 and -2.5 ms, respectively). Placebo-corrected QTcI for moxifloxacin was +10.4 ms (lower 90% confidence bound >0 [6.6 ms]), which established assay sensitivity for this trial. As lacosamide did not increase QTcI, the trial is considered a negative QTc trial. There was no dose-related or clinically relevant effect on QRS duration. HR increased from baseline by ~5 bpm with lacosamide 800 mg/day versus placebo. Placebo-subtracted mean increases in PR interval at tmax were 7.3 ms (400 mg/day) and 11.9 ms (800 mg/day). There were no findings of second-degree or higher atrioventricular block. Adverse events (AEs) were dose related and most commonly involved the nervous and gastrointestinal systems. Lacosamide (≤ 800 mg/day) did not prolong the QTc interval. Lacosamide caused a small, dose-related increase in mean PR interval that was not associated with AEs. Cardiac, overall safety, and PK profiles for lacosamide in healthy volunteers were consistent with those observed in patients with partial-onset seizures. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Alternating current loss characteristics in (bismuth,lead)SCCO and yttrium barium copper oxide superconducting tapes

NASA Astrophysics Data System (ADS)

Nguyen, Doan Ngoc

Alternating current (AC) loss and current carrying capacity are two of the most crucial considerations in large-scale power applications of high temperature superconducting (HTS) conductors. AC losses result in an increased thermal load for cooling machines, and thus increased operating costs. Furthermore, AC losses can stimulate quenching phenomena or at least decrease the stability margin for superconducting devices. Thus, understanding AC losses is essential for the development of HTS AC applications. The main focus of this dissertation is to make reliable total AC loss measurements and interpret the experimental results in a theoretical framework. With a specially designed magnet, advanced total AC loss measurement system in liquid nitrogen (77 K) has been successfully built. Both calorimetric and electromagnetic methods were employed to confirm the validity of the measured results and to have a more thorough understanding of AC loss in HTS conductors. The measurement is capable of measuring total AC loss in HTS tapes over a wide range of frequency and amplitude of transport current and magnetic field. An accurate phase control technique allows measurement of total AC loss with any phase difference between the transport current and magnetic field by calorimetric method. In addition, a novel total AC loss measurement system with variable temperatures from 30 K to 100 K was successfully built and tested. Understanding the dependence of AC losses on temperature will enable optimization of the operating temperature and design of HTS devices. As a part of the dissertation, numerical calculations using Brandt's model were developed to study electrodynamics and total AC loss in HTS conductors. In the calculations, the superconducting electrical behavior is assumed to follow a power-law model. In general, the practical properties of conductors, including field-dependence of critical current density Jc, n-value and non-uniform distribution of Jc, can be accounted for in the numerical calculations. The numerical calculations are also capable of investigating eddy current loss in the stabilizer and ferromagnetic loss in the substrate of YBa2Cu3O 7-delta (YBCO) coated conductor. AC loss characteristics and electrodynamics in several (Bi,Pb)2 Sr2Ca2Cu3Ox (Bi-2223) and YBCO tapes were studied experimentally and numerically. It was found that AC loss behavior Ax in HTS tapes is strongly affected by the sample parameters such as cross-section, structure, dimensions, critical current distribution as well as by operation parameters including temperature, frequency, the phase difference between transport current and magnetic field, the orientation of magnetic field. The Ni-5%W substrate in YBCO conductors generates some ferromagnetic loss but this loss component is significantly reduced by a small parallel DC magnetic field. At a given AC magnetic field B0, there is a temperature Tmax at which the magnetization loss is maximum. The design of HTS devices needs to be optimized to avoid operating at that temperature. In general, the total AC loss in HTS tapes is still high for many power device applications, especially for those that present a rather high AC applied magnetic field. The development of low loss conductors is therefore crucial for HTS large-scale applications.

Intestinal absorption of calcium from calcium ascorbate in rats.

PubMed

Tsugawa, N; Yamabe, T; Takeuchi, A; Kamao, M; Nakagawa, K; Nishijima, K; Okano, T

1999-01-01

The intestinal absorption of calcium (Ca) from Ca ascorbate (Ca-AsA) was investigated in normal rats. Each animal was perorally administered either 5mg (low dose) or 10mg (high dose) of Ca in 1ml of distilled water as Ca-AsA, Ca carbonate (CaCO3), or Ca chloride (CaCl2), which were intrinsically labeled with 45Ca using 45CaCl2. The amount of radioactivity in plasma was measured periodically up to 34h after dosing, and pharmacokinetic parameters were calculated from the radioactivity in plasma. The time taken to reach the maximum 45Ca level (Tmax) did not differ among the three groups. The area under the plasma 45Ca level/time curve (AUCinfinity) value for the Ca-AsA group was significantly higher than those for the CaCO3 and the CaCl2 groups. The radioactivity at Tmax (Cmax) for the Ca-AsA group was significantly higher than those for the CaCO3 and the CaCl2 groups for the low dose, and comparable with or significantly higher than those for the CaCl2 and CaCO3 groups for the high dose. Similar results were observed for whole-body 45Ca retention. Radioactivity in the femur 34h after dosing was the highest in the Ca-AsA group and the lowest in the CaCO3 group. The rank order of solubility in water, the first fluid (pH 1.2, JP-1) of JPXIII disintegration medium, acetate buffer solution (pH 4.0), triethanolamine-malate buffer solution (pH 7.0) and ammonium chloride buffer solution (pH 10.0) at 37 degrees C was CaCl2 > Ca-AsA > CaCO3. In contrast, the rank order of the solubility in the second fluid (pH 6.8, JP-2) of JPXIII disintegration medium at 37 degrees C was Ca-AsA > CaCl2 > CaCO3. These results indicate that the absorbability of Ca from Ca-AsA is almost comparable with, or higher than, that from CaCl2 and significantly higher than that from CaCO3 because of its high degree of solubility in the intestine. Therefore, Ca-AsA would be useful as a Ca supplement with relatively high absorption from intestine.

Clinical utility of topiramate extended-release capsules (USL255): Bioequivalence of USL255 sprinkled and intact capsule in healthy adults and an in vitro evaluation of sprinkle delivery via enteral feeding tubes.

PubMed

Clark, Annie M; Pellock, John M; Holmay, Mary; Anders, Bob; Cloyd, James

2016-04-01

The objectives of these two studies were to determine if beads from extended-release topiramate capsules sprinkled onto soft food are bioequivalent to the intact capsule and if beads from the capsule can be passed through enteral gastrostomy (G-) and jejunostomy (J-) feeding tubes. Bioequivalence of 200-mg USL255 (Qudexy XR [topiramate] extended-release capsules) sprinkled onto soft food (applesauce) versus the intact capsule was evaluated in a phase 1, randomized, single-dose, crossover study (N=36). Pharmacokinetic evaluations included area under the curve (AUC), maximum plasma concentration (Cmax), time to Cmax (Tmax), and terminal elimination half-life (t1/2). If 90% confidence intervals (CI) of the ratio of geometric least-squares means were between 0.80 and 1.25, AUC and Cmax were considered bioequivalent. In separate in vitro experiments, 100-mg USL255 beads were passed through feeding tubes using gentle syringe pressure to develop a clog-free bead-delivery method. Multiple tube sizes (14- to 18-French [Fr] tubes), dilutions (5 mg/15 mL-25 mg/15 mL), and diluents (deionized water, apple juice, Ketocal, sparkling water) were tested. Area under the curve and Cmax for USL255 beads sprinkled onto applesauce were bioequivalent to the intact capsule (GLSM [90% CI]: AUC0-t 1.01 [0.97-1.04], AUC0-∞ 1.02 [0.98-1.05]; Cmax 1.09 [1.03-1.14]). Median Tmax was 4h earlier for USL255 sprinkled versus the intact capsule (10 vs 14 h; p=0.0018), and t1/2 was similar (84 vs 82 h, respectively). In 14-Fr G-tubes, USL255 beads diluted in Ketocal minimized bead clogging versus deionized water. Recovery of USL255 beads diluted in deionized water was nearly 100% in 16-Fr G-, 18-Fr G-, and 18-Fr J-tubes. For patients with difficulty swallowing pills, USL255 sprinkled onto applesauce offers a useful once-daily option for taking topiramate. USL255 beads were also successfully delivered in vitro through ≥14-Fr G- or J-tubes, with tube clogging minimized by portioning the dose and using glidant diluents for smaller tubes. Copyright © 2016 Upsher-Smith Laboratories, Inc. Published by Elsevier Inc. All rights reserved.

Randomized, double-blind, placebo-controlled study about the effects of cannabidiol (CBD) on the pharmacokinetics of Delta9-tetrahydrocannabinol (THC) after oral application of THC verses standardized cannabis extract.

PubMed

Nadulski, Thomas; Pragst, Fritz; Weinberg, Gordon; Roser, Patrik; Schnelle, Martin; Fronk, Eva-Maria; Stadelmann, Andreas Michael

2005-12-01

Cannabidiol (CBD) is known to modify the effects of Delta-tetrahydrocannabinol (THC) by decreasing anxiety and antagonizing other THC-effects. As a reason, pharmacodynamic as well as pharmacokinetic mechanisms were suggested. In context of the use of cannabis-based medicine extracts for therapeutic purposes, a study was performed in a double-blind and placebo-controlled cross-over design in which each of 24 volunteers (12 male and 12 female, age 18-45 years) obtained soft-gelatin capsules with 10 mg THC (THC-set), cannabis extract containing 10 mg THC +5.4 mg CBD (CAN-set) or placebo in weekly intervals. Blood samples were taken 30 minutes before and 30 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 6 hours, 9 hours and 24 hours after the intake. The concentrations of THC, of its metabolites 11-OH-THC, THC-COOH and of CBD in the plasma samples were determined by automatic solid phase extraction, derivatization with N,O-bis(trimethylsilyl)triflouroacetamide and gas chromatography-mass spectrometry. The concentration versus time curves (maximum concentrations Cmax, corresponding time tmax and areas under the curves AUC) were evaluated by statistical methods with respect to equivalence or differences between the CAN-set and the THC-set. Furthermore, the intra-individual ratios of Cmax and AUC for 11-OH-THC/THC, THC-COOH/THC and THC-COOH/11-OH-THC were compared between the THC-set and the CAN-set. Despite the large variation of the data, evidence emerged from the total of the results that CBD partially inhibits the CYP 2C catalyzed hydroxylation of THC to 11-OH-THC. The probability for this inhibition is particularly high for oral intake because THC and CBD attain relatively high concentrations in the liver and because of the high first-pass metabolism of THC. However, the effect of CBD is small in comparison to the variability caused by other factors. Therefore, a pharmacokinetic reason for the differences determined between pure THC and cannabis extract is improbable at the doses chosen in this study. Significantly higher AUC and Cmax and shorter tmax were found for females as compared with males.

Kinetics of absorption and elimination of ofloxacin in humans after oral and rectal administrations.

PubMed

Eboka, C J; Okor, R S; Akerele, J O; Aigbavboa, S O

1997-06-01

Ofloxacin pharmacokinetics have been studied in four healthy subjects after a single oral or rectal dose, each of 200 mg. For the oral dose tmax was about 2 h, Cmax 1.96 +/- 0.56 micrograms/ml and AUC1-15 15.22 micrograms/ml.h. Two-phase elimination pharmacol kinetics were observed for the oral dose, t1/2 for the rapid elimination phase was 3.3 h and for the slow phase 10 h. With the rectal dose tmax was 6 h, Cmax 0.71 +/- 0.44 microgram/ml and AUC0-15 7.58 micrograms/ml.h. The relative rectal bioavailability (AUC rectal/AUC oral) was 49.8%. Elimination rate of the rectal dose was generally slow (t1/2 = 9 h), an observation attributable to the sustained-release effect of the rectal suppository base, PEG 6000. The indication is that the rectal formulation cannot be substituted totally for the oral without first increasing the rectal dose; the 200 mg suppository can however be employed as a follow-up therapy to the oral dose in certain situations.

Analysis of temperature trends in Northern Serbia

NASA Astrophysics Data System (ADS)

Tosic, Ivana; Gavrilov, Milivoj; Unkašević, Miroslava; Marković, Slobodan; Petrović, Predrag

2017-04-01

An analysis of air temperature trends in Northern Serbia for the annual and seasonal time series is performed for two periods: 1949-2013 and 1979-2013. Three data sets of surface air temperatures: monthly mean temperatures, monthly maximum temperatures, and monthly minimum temperatures are analyzed at 9 stations that have altitudes varying between 75 m and 102 m. Monthly mean temperatures are obtained as the average of the daily mean temperatures, while monthly maximum (minimum) temperatures are the maximum (minimum) values of daily temperatures in corresponding month. Positive trends were found in 29 out of 30 time series, and the negative trend was found only in winter during the period 1979-2013. Applying the Mann-Kendall test, significant positive trends were found in 15 series; 7 in the period 1949-2013 and 8 in the period 1979-2013; and no significant trend was found in 15 series. Significant positive trends are dominated during the year, spring, and summer, where it was found in 14 out of 18 cases. Significant positive trends were found 7, 5, and 3 times in mean, maximum and minimum temperatures, respectively. It was found that the positive temperature trends are dominant in Northern Serbia.

Reactivity of a Carbon-Supported Single-Site Molybdenum Dioxo Catalyst for Biodiesel Synthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mouat, Aidan R.; Lohr, Tracy L.; Wegener, Evan C.

2016-08-23

A single-site molybdenum dioxo catalyst, (O c) 2Mo(=O) 2@C, was prepared via direct grafting of MoO 2Cl 2(dme) (dme = 1,2-dimethoxyethane) on high-surface- area activated carbon. The physicochemical and chemical properties of this catalyst were fully characterized by N 2 physisorption, ICP-AES/OES, PXRD, STEM, XPS, XAS, temperature-programmed reduction with H 2 (TPR-H 2), and temperature-programmed NH 3 desorption (TPD-NH 3). The single-site nature of the Mo species is corroborated by XPS and TPR-H 2 data, and it exhibits the lowest reported MoO x Tmax of reduction reported to date, suggesting a highly reactive MoVI center. (O c) 2Mo(=O) 2@C catalyzesmore » the transesterification of a variety of esters and triglycerides with ethanol, exhibiting high activity at moderate temperatures (60-90 °C) and with negligible deactivation. (O c) 2Mo(=O) 2@C is resistant to water and can be recycled at least three times with no loss of activity. The transesterification reaction is determined experimentally to be first order in [ethanol] and first order in [Mo] with ΔH = 10.5(8) kcal mol -1 and ΔS = -32(2) eu. The low energy of activation is consistent with the moderate conditions needed to achieve rapid turnover. This highly active carbon-supported single-site molybdenum dioxo species is thus an efficient, robust, and lowcost catalyst with significant potential for transesterification processes.« less

A basin-scale approach to estimating stream temperatures of tributaries to the lower Klamath River, California

USGS Publications Warehouse

Flint, L.E.; Flint, A.L.

2008-01-01

Stream temperature is an important component of salmonid habitat and is often above levels suitable for fish survival in the Lower Klamath River in northern California. The objective of this study was to provide boundary conditions for models that are assessing stream temperature on the main stem for the purpose of developing strategies to manage stream conditions using Total Maximum Daily Loads. For model input, hourly stream temperatures for 36 tributaries were estimated for 1 Jan. 2001 through 31 Oct. 2004. A basin-scale approach incorporating spatially distributed energy balance data was used to estimate the stream temperatures with measured air temperature and relative humidity data and simulated solar radiation, including topographic shading and corrections for cloudiness. Regression models were developed on the basis of available stream temperature data to predict temperatures for unmeasured periods of time and for unmeasured streams. The most significant factor in matching measured minimum and maximum stream temperatures was the seasonality of the estimate. Adding minimum and maximum air temperature to the regression model improved the estimate, and air temperature data over the region are available and easily distributed spatially. The addition of simulated solar radiation and vapor saturation deficit to the regression model significantly improved predictions of maximum stream temperature but was not required to predict minimum stream temperature. The average SE in estimated maximum daily stream temperature for the individual basins was 0.9 ?? 0.6??C at the 95% confidence interval. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Comparison of echocardiographic and pressure-volume loop indices of systolic function in patients with single ventricle physiology: a preliminary report.

PubMed

Butts, Ryan J; Chowdhury, Shahryar M; Buckley, Jason; Hlavacek, Anthony M; Hsia, Tain Yen; Khambadkone, Sachin; Baker, G Hamilton

2015-01-01

Differences in ventricular geometry and physiology of patients with single ventricle anatomy complicate the application of traditional, noninvasive measurements of systolic function. We compared noninvasive measures of ventricular systolic function in single ventricle patients with invasive measures to evaluate their validity in this population. A secondary analysis of patients with single ventricle physiology enrolled in the multi-institutional research project, "multi-scale modeling of single ventricle hearts," was performed. Pressure-volume loops (PVLs) were recorded using microconductance catheters. Transthoracic echocardiogram and cardiac magnetic resonance imaging were performed on the same day. PVL indices of systolic function including end-systolic elastance (Ees), maximal rate of pressure increase (dP/dTmax), and stroke work indexed to end-diastolic volume (SW/EDV) were compared with noninvasive measures, including echocardiographic myocardial performance index (MPI), rate of pressure rise (AV valve dP/dT), isovolumic acceleration, longitudinal shortening fraction (longSF), and fractional area change (FAC). Fifteen patients had PVLs available for analysis. Eleven had a dominant right ventricle, three were status poststage 1 repair, five had superior cavopulmonary anastomosis, and seven had a total cavopulmonary anastomosis. FAC correlated with Ees (r = 0.69, P < .01), SW/EDV (r = 0.64, P = .01), and dP/dTmax (r = 0.59, P = .03). LongSF correlated with dP/dTmax (r = 0.61, P = .02) MPI, AV valve dP/dT, and isovolumic acceleration did not correlate with pressure-volume loop indices of systolic function. Obtaining PVLs via microconductance catheters can reliably be performed in the single ventricle population and serve as a method to validate echocardiographic indices in this high-risk population. Of the echocardiographic variables, FAC showed the best correlation with PVL indices. Future studies controlling for stage of palliation should be performed to further validate echocardiographic measures of systolic function in this patient population. © 2014 Wiley Periodicals, Inc.

Folate bioavailability from foods rich in folates assessed in a short term human study using stable isotope dilution assays.

PubMed

Mönch, Sabine; Netzel, Michael; Netzel, Gabriele; Ott, Undine; Frank, Thomas; Rychlik, Michael

2015-01-01

Different sources of folate may have different bioavailability and hence may impact the standard definition of folate equivalents. In order to examine this, a short term human study was undertaken to evaluate the relative native folate bioavailabilities from spinach, Camembert cheese and wheat germs compared to pteroylmonoglutamic acid as the reference dose. The study had a single-centre, randomised, four-treatment, four-period, four-sequence, cross-over design, i.e. the four (food) items to be tested (referred to as treatments) were administered in sequences according to the Latin square, so that each experimental treatment occurred only once within each sequence and once within each study period. Each of the 24 subjects received the four experimental items separated by a 14-day equilibrium phase and received a pteroylmonoglutamic acid supplement for 14 days before the first testing and between the testings for saturation of body pools. Folates in test foods, plasma and urine samples were determined by stable isotope dilution assays, and in urine and plasma, the concentrations of 5-methyltetrahydrofolate were evaluated. Standard non-compartmental methods were applied to determine the biokinetic parameters C(max), t(max) and AUC from baseline corrected 5-methyltetrahydrofolate concentrations within the interval from 0 to 12 hours. The variability of AUC and C(max) was moderate for spinach and oral solution of pteroylmonoglutamic acid but high for Camembert cheese and very high for wheat germs. The median t(max) was lowest for spinach, though t(max) showed a high variability among all treatments. When comparing the ratio estimates of AUC and C(max) for the different test foods, highest bioavailability was found for spinach followed by that for wheat germs and Camembert cheese. The results underline the dependence of folate bioavailability on the type of food ingested. Therefore, the general assumption of 50% bioavailability as the rationale behind the definition of folate equivalents has to be questioned and requires further investigation.

Effects of negative pressures on epithelial tight junctions and migration in wound healing.

PubMed

Hsu, Chih-Chin; Tsai, Wen-Chung; Chen, Carl Pai-Chu; Lu, Yun-Mei; Wang, Jong-Shyan

2010-08-01

Negative-pressure wound therapy has recently gained popularity in chronic wound care. This study attempted to explore effects of different negative pressures on epithelial migration in the wound-healing process. The electric cell-substrate impedance sensing (ECIS) technique was used to create a 5 x 10(-4) cm(2) wound in the Madin-Darby canine kidney (MDCK) and human keratinocyte (HaCaT) cells. The wounded cells were cultured in a negative pressure incubator at ambient pressure (AP) and negative pressures of 75 mmHg (NP(75)), 125 mmHg (NP(125)), and 175 mmHg (NP(175)). The effective time (ET), complete wound healing time (T(max)), healing rate (R(heal)), cell diameter, and wound area over time at different pressures were evaluated. Traditional wound-healing assays were prepared for fluorescent staining of cells viability, cell junction proteins, including ZO-1 and E-cadherin, and actins. Amount of cell junction proteins at AP and NP(125) was also quantified. In MDCK cells, the ET (1.25 +/- 0.27 h), T(max) (1.76 +/- 0.32 h), and R(heal) (2.94 +/- 0.62 x 10(-4) cm(2)/h) at NP(125) were significantly (P < 0.01) different from those at three other pressure conditions. In HaCaT cells, the T(max) (7.34 +/- 0.29 h) and R(heal) (6.82 +/- 0.26 x 10(-5) cm(2)/h) at NP(125) were significantly (P < 0.01) different from those at NP(75). Prominent cell migration features were identified in cells at the specific negative pressure. Cell migration activities at different pressures can be documented with the real-time wound-healing measurement system. Negative pressure of 125 mmHg can help disassemble the cell junction to enhance epithelial migration and subsequently result in quick wound closure.

Dynamic Magnetic Resonance Angiography Provides Collateral Circulation and Hemodynamic Information in Acute Ischemic Stroke.

PubMed

Hernández-Pérez, María; Puig, Josep; Blasco, Gerard; Pérez de la Ossa, Natalia; Dorado, Laura; Dávalos, Antoni; Munuera, Josep

2016-02-01

Contrary to usual static vascular imaging techniques, contrast-enhanced dynamic magnetic resonance angiography (dMRA) enables dynamic study of cerebral vessels. We evaluated dMRA ability to assess arterial occlusion, cerebral hemodynamics, and collateral circulation in acute ischemic stroke. Twenty-five acute ischemic stroke patients with proximal anterior circulation occlusion underwent dMRA on a 3T scanner within 12 hours of symptoms onset. Diffusion weighted imaging, Tmax6 s lesion volumes and hypoperfusion intensity ratio as volume of Tmax>6 s/volume of Tmax>10 s were measured. Site and grade of occlusion (Thrombolysis in Myocardial Infarction criteria) were evaluated on time-of-flight MRA and dMRA. Leptomeningeal collaterality (American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology [ASITN/SIR] Scale) and asymmetries in venous clearance were assessed exclusively on dMRA. Collateral filling was dichotomized into incomplete (ASITN/SIR 0-2) or complete (ASITN/SIR 3-4). On dMRA, site of occlusion was M1 in 21 patients, tandem internal carotid artery/M1 in 2 and tandem internal carotid artery/terminal internal carotid artery in 2 patients. Three tandem occlusions were not detected on time-of-flight-MRA. All patients had Thrombolysis in Myocardial Infarction 0 to 1 on time-of-flight-MRA, but three of them had Thrombolysis in Myocardial Infarction 2 on dMRA. Complete collateral filling (n=12, 48%) was associated with smaller diffusion weighted imaging lesion volume (P=0.039), smaller hypoperfused volume (P=0.018), and lower hypoperfusion intensity ratio (P=0.006). Patients with symmetrical clearance of transverse sinuses (52%) were more likely to have complete collateral filling (P=0.015). As a fast, direct, feasible, noninvasive, and reliable method to assess site of occlusion, collateral circulation and hemodynamic alterations, dMRA provides profound insights in acute stroke. © 2015 American Heart Association, Inc.

[Simultaneous determination of daphnetin, daphnoretin, daphneticin in rat plasma by LC-MS/MS and its application in pharmacokinetic study].

PubMed

Hu, Yi-Yi-Li-Ge-Qi; Cao, Sa-Li; Lin, Long-Fei; Fu, Jing; Dong, Xiao-Xu; Yang, Chun-Jing; Zhang, Miao; Ni, Jian

2017-05-01

To establish HPLC-MS/MS method for simultaneous determination of daphnetin, daphnoretin, and daphneticin in rat plasma after oral and intravenous administration of Daphne giraldii extract, and then use them in the calculation of pharmacokinetic parameters. Six sprague-dawley rats received intragastric administration of D. giraldii extract (daphnetin, daphnoretin and daphneticin were 88.40, 3.24 and 4.28 mg•kg⁻¹, respectively). Their drug plasma concentration was determined by LC-MS/MS with schisandrin as an internal standard to draw plasma concentration-time curve. The pharmacokinetic parameters were calculated by Kinetica 4.4. The results showed that the linear range was 5-1 000 μg•L⁻¹ for daphnetin, daphnoretin and daphneticin, and the method ological test showed conformance to the requirements.The intraday and inter-day variable coefficients (RSD) were both less than 15.0%, indicating that both of legitimate precise and accuracy were consistent with the analysis requirements of biological samples. For daphnetin, the pharmacokinetic parameters Tmax, Cmax, AUC0-t, T1/2 and MRT were 4 h, 858.96 μg•L⁻¹, 10 566.4 μg•L⁻¹•h, 5.19 h and 9.43 h, respectively. For daphnoretin, the pharmacokinetic parameters Tmax, Cmax, AUC0-t, T1/2 and MRT were 2.92 h, 178.00 μg•L⁻¹, 905.89 μg•L⁻¹•h, 3.50 h and 6.95 h, respectively. For daphneticin, the pharmacokinetic parameters Tmax, Cmax, AUC0-t, T1/2 and MRT were 2 h, 36.67 μg•L⁻¹, 355.11 μg•L⁻¹•h, 4.95 h and 8.27 h, respectively. The LC-MS/MS analysis method established in this study was proved to be so accurate and sensitive that it can be applied to the pharmacokinetic study of daphnetin, daphnoretin and daphneticin. Copyright© by the Chinese Pharmaceutical Association.

Time-Dependent Computed Tomographic Perfusion Thresholds for Patients With Acute Ischemic Stroke.

PubMed

d'Esterre, Christopher D; Boesen, Mari E; Ahn, Seong Hwan; Pordeli, Pooneh; Najm, Mohamed; Minhas, Priyanka; Davari, Paniz; Fainardi, Enrico; Rubiera, Marta; Khaw, Alexander V; Zini, Andrea; Frayne, Richard; Hill, Michael D; Demchuk, Andrew M; Sajobi, Tolulope T; Forkert, Nils D; Goyal, Mayank; Lee, Ting Y; Menon, Bijoy K

2015-12-01

Among patients with acute ischemic stroke, we determine computed tomographic perfusion (CTP) thresholds associated with follow-up infarction at different stroke onset-to-CTP and CTP-to-reperfusion times. Acute ischemic stroke patients with occlusion on computed tomographic angiography were acutely imaged with CTP. Noncontrast computed tomography and magnectic resonance diffusion-weighted imaging between 24 and 48 hours were used to delineate follow-up infarction. Reperfusion was assessed on conventional angiogram or 4-hour repeat computed tomographic angiography. Tmax, cerebral blood flow, and cerebral blood volume derived from delay-insensitive CTP postprocessing were analyzed using receiver-operator characteristic curves to derive optimal thresholds for combined patient data (pooled analysis) and individual patients (patient-level analysis) based on time from stroke onset-to-CTP and CTP-to-reperfusion. One-way ANOVA and locally weighted scatterplot smoothing regression was used to test whether the derived optimal CTP thresholds were different by time. One hundred and thirty-two patients were included. Tmax thresholds of >16.2 and >15.8 s and absolute cerebral blood flow thresholds of <8.9 and <7.4 mL·min(-1)·100 g(-1) were associated with infarct if reperfused <90 min from CTP with onset <180 min. The discriminative ability of cerebral blood volume was modest. No statistically significant relationship was noted between stroke onset-to-CTP time and the optimal CTP thresholds for all parameters based on discrete or continuous time analysis (P>0.05). A statistically significant relationship existed between CTP-to-reperfusion time and the optimal thresholds for cerebral blood flow (P<0.001; r=0.59 and 0.77 for gray and white matter, respectively) and Tmax (P<0.001; r=-0.68 and -0.60 for gray and white matter, respectively) parameters. Optimal CTP thresholds associated with follow-up infarction depend on time from imaging to reperfusion. © 2015 American Heart Association, Inc.

Thermal Modelling Analysis of Spiral Wound Supercapacitor under Constant-Current Cycling

PubMed Central

Wang, Kai; Li, Liwei; Yin, Huaixian; Zhang, Tiezhu; Wan, Wubo

2015-01-01

A three-dimensional modelling approach is used to study the effects of operating and ambient conditions on the thermal behaviour of the spiral wound supercapacitor. The transient temperature distribution during cycling is obtained by using the finite element method with an implicit predictor-multicorrector algorithm. At the constant current of 2A, the results show that the maximum temperature appears in core area. After 5 cycles, the maximum temperature is 34.5°C, while in steady state, it’s up to 42.5°C. This paper further studies the relationship between the maximum temperature and charge-discharge current. The maximum temperature will be more than 60°C after 5 cycles at the current of 4A, and cooling measurements should be taken at that time. It can provide thoughts on inner temperature field distribution and structure design of the spiral wound supercapacitor in working process. PMID:26444687

Extratropical Cyclones Leading to Extreme Weather Events over Central and Eastern North America

NASA Astrophysics Data System (ADS)

Bentley, Alicia M.

Cool-season extreme weather events (EWEs) occurring over central and eastern North America are typically associated with strong extratropical cyclones (ECs) that are governed by varying combinations of baroclinic, diabatic, and barotropic processes. This dissertation investigates the climatology, evolution, and predictability of ECs leading to EWEs over central and eastern North America, and provides a foundation on which to compare ECs leading to EWEs to ordinary ECs forming over and traversing the same regions. A climatology of ECs leading to EWEs over central and eastern North America during October-March 1979-2016 reveals that these ECs typically form 1) in the lee of the Rocky Mountains, 2) over the south central U.S., and 3) along the east coast of North America at latitudes equatorward of the typical genesis locations of ordinary ECs. ECs leading to EWEs included in the climatology form most frequently in November and March, when the seasonal alignment of baroclinic and convectively driven forcings occurs. Consistent with previous studies of North American ECs, the location and frequency of ECs leading to EWEs are partially determined by the states of the Pacific-North American pattern and the North Atlantic Oscillation. Metrics representing baroclinic, diabatic, and barotropic processes are formulated in this dissertation and are used to determine the combinations of baroclinic, diabatic, and barotropic processes associated with the formation and maintenance of ordinary ECs and ECs leading to EWEs. These metrics reveal that ECs leading to EWEs are associated with contributions from baroclinic, diabatic, and barotropic processes that are 1) similar to those associated with ordinary ECs at the time of formation (t0) and 2) considerably larger than those associated with ordinary ECs at the time of maximum intensity (tmax). Baroclinic processes typically contribute more than diabatic and barotropic processes throughout the evolution of ECs leading to EWEs. Diabatic processes typically contribute more during the intensification of ECs leading to EWEs than during their maintenance after tmax, whereas barotropic processes typically contribute more during the maintenance of ECs leading to EWEs after tmax than during their intensification. The relative contributions from baroclinic, diabatic, and barotropic processes during the evolution of ECs leading to EWEs are also shown to differ based on their genesis location. The 1.0° NOAA Global Ensemble Forecast System (GEFS) reforecast dataset is used in this dissertation to evaluate the forecast skill associated with ordinary ECs and ECs leading to EWEs at 0-192-h lead times. Ordinary ECs are consistently too slow and left of track in the GEFS, and are often too weak at longer lead times. ECs leading to EWEs are consistently too weak, fast, and right of track in the GEFS at longer lead times, and consistently too strong, slow, and left of track at shorter lead times. The positions of ordinary ECs are forecast with less skill and more spread than the positions of ECs leading to EWEs in the GEFS, whereas the intensities of ordinary ECs and ECs leading to EWEs are forecast with similar skill and spread. Locations over central and eastern North America where the positions and intensities of ordinary ECs and ECs leading to EWEs are frequently forecast with relatively low and high skill and spread in the GEFS are also identified.

Effects of Pouring Temperature and Electromagnetic Stirring on Porosity and Mechanical Properties of A357 Aluminum Alloy Rheo-Diecasting

NASA Astrophysics Data System (ADS)

Guo, An; Zhao, Junwen; Xu, Chao; Li, Hu; Han, Jing; Zhang, Xu

2018-05-01

Semisolid slurry of A357 aluminum alloy was prepared using a temperature-controllable electromagnetic stirrer and rheo-diecast at different temperatures. The effects of pouring temperature and electromagnetic stirring (EMS) on the porosity in rheo-diecast samples, as well as the relation between porosity and mechanical properties, were investigated. The results show that pouring temperature and EMS had minor influences on rheo-diecast microstructure but marked influence on the porosity. With decreasing slurry pouring temperature, the porosity decreased first and then increased, whereas the maximum pore ratio (ratio of shape factor to diameter of the largest pore) increased first and then decreased. The maximum pore ratio determines the level of tensile strength and elongation, and higher mechanical properties can be obtained with smaller and rounder pores in samples. The mechanical properties of the rheo-diecast samples increased linearly with increasing maximum pore ratio. The maximum pore ratio was 1.43 µm-1, and the minimum porosity level was 0.37% under EMS condition for the rheo-diecast samples obtained at a pouring temperature of 608 °C. With this porosity condition, the maximum tensile strength and elongation were achieved at 274 MPa and 4.9%, respectively. It was also revealed that EMS improves mechanical properties by reduction in porosity and an increase in maximum pore ratio.

Temperature and pressure influence on maximum rates of pressure rise during explosions of propane-air mixtures in a spherical vessel.

PubMed

Razus, D; Brinzea, V; Mitu, M; Movileanu, C; Oancea, D

2011-06-15

The maximum rates of pressure rise during closed vessel explosions of propane-air mixtures are reported, for systems with various initial concentrations, pressures and temperatures ([C(3)H(8)]=2.50-6.20 vol.%, p(0)=0.3-1.3 bar; T(0)=298-423 K). Experiments were performed in a spherical vessel (Φ=10 cm) with central ignition. The deflagration (severity) index K(G), calculated from experimental values of maximum rates of pressure rise is examined against the adiabatic deflagration index, K(G, ad), computed from normal burning velocities and peak explosion pressures. At constant temperature and fuel/oxygen ratio, both the maximum rates of pressure rise and the deflagration indices are linear functions of total initial pressure, as reported for other fuel-air mixtures. At constant initial pressure and composition, the maximum rates of pressure rise and deflagration indices are slightly influenced by the initial temperature; some influence of the initial temperature on maximum rates of pressure rise is observed only for propane-air mixtures far from stoichiometric composition. The differentiated temperature influence on the normal burning velocities and the peak explosion pressures might explain this behaviour. Copyright © 2011 Elsevier B.V. All rights reserved.

Change in mean temperature as a predictor of extreme temperature change in the Asia-Pacific region

NASA Astrophysics Data System (ADS)

Griffiths, G. M.; Chambers, L. E.; Haylock, M. R.; Manton, M. J.; Nicholls, N.; Baek, H.-J.; Choi, Y.; della-Marta, P. M.; Gosai, A.; Iga, N.; Lata, R.; Laurent, V.; Maitrepierre, L.; Nakamigawa, H.; Ouprasitwong, N.; Solofa, D.; Tahani, L.; Thuy, D. T.; Tibig, L.; Trewin, B.; Vediapan, K.; Zhai, P.

2005-08-01

Trends (1961-2003) in daily maximum and minimum temperatures, extremes and variance were found to be spatially coherent across the Asia-Pacific region. The majority of stations exhibited significant trends: increases in mean maximum and mean minimum temperature, decreases in cold nights and cool days, and increases in warm nights. No station showed a significant increase in cold days or cold nights, but a few sites showed significant decreases in hot days and warm nights. Significant decreases were observed in both maximum and minimum temperature standard deviation in China, Korea and some stations in Japan (probably reflecting urbanization effects), but also for some Thailand and coastal Australian sites. The South Pacific convergence zone (SPCZ) region between Fiji and the Solomon Islands showed a significant increase in maximum temperature variability.Correlations between mean temperature and the frequency of extreme temperatures were strongest in the tropical Pacific Ocean from French Polynesia to Papua New Guinea, Malaysia, the Philippines, Thailand and southern Japan. Correlations were weaker at continental or higher latitude locations, which may partly reflect urbanization.For non-urban stations, the dominant distribution change for both maximum and minimum temperature involved a change in the mean, impacting on one or both extremes, with no change in standard deviation. This occurred from French Polynesia to Papua New Guinea (except for maximum temperature changes near the SPCZ), in Malaysia, the Philippines, and several outlying Japanese islands. For urbanized stations the dominant change was a change in the mean and variance, impacting on one or both extremes. This result was particularly evident for minimum temperature.The results presented here, for non-urban tropical and maritime locations in the Asia-Pacific region, support the hypothesis that changes in mean temperature may be used to predict changes in extreme temperatures. At urbanized or higher latitude locations, changes in variance should be incorporated.

Influence of stream characteristics and grazing intensity on stream temperatures in eastern Oregon.

Treesearch

S.B. Maloney; A.R. Tiedemann; D.A. Higgins; T.M. Quigley; D.B. Marx

1999-01-01

Stream temperatures were measured during summer months, 1978 to 1984, at 12 forested watersheds near John Day, Oregon, to determine temperature characteristics and assess effects of three range management strategies of increasing intensity. Maximum temperatures in streams of the 12 watersheds ranged from 12.5 to 27.8 oC. Maximum stream temperatures on four watersheds...

Relativistic equipartition via a massive damped sliding partition

NASA Astrophysics Data System (ADS)

Crawford, Frank S.

1993-04-01

A cylinder partitioned by a massive sliding slab undergoing nonrelativistic damped one-dimensional (1D) motion under bombardment from the left (i=1) and right (i=2) by particles having rest mass mi, speed vi, relativistic momentum (magnitude) pi, and (let c≡1) total energy Ei=(pi2+mi2)1/2 is considered herein. The damped slab of mass M transforms the system from its initial pi distributions (i=1,2) to a state, first, of pressure (P) equilibrium with P1=P2, but temperature T1≠T2, then, to P-T equilibrium with P1=P2 and T1=T2, given by the (1D) ``first moment'' equipartition relation (κ is Boltzmann's constant),

14 CFR 23.1521 - Powerplant limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... reciprocating engines); (3) The maximum allowable gas temperature (for turbine engines); (4) The time limit for... maximum allowable gas temperature (for turbine engines); and (4) The maximum allowable cylinder head, oil... reciprocating engines), or fuel designation (for turbine engines), must be established so that it is not less...

14 CFR 23.1521 - Powerplant limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... reciprocating engines); (3) The maximum allowable gas temperature (for turbine engines); (4) The time limit for... maximum allowable gas temperature (for turbine engines); and (4) The maximum allowable cylinder head, oil... reciprocating engines), or fuel designation (for turbine engines), must be established so that it is not less...

14 CFR 23.1521 - Powerplant limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... reciprocating engines); (3) The maximum allowable gas temperature (for turbine engines); (4) The time limit for... maximum allowable gas temperature (for turbine engines); and (4) The maximum allowable cylinder head, oil... reciprocating engines), or fuel designation (for turbine engines), must be established so that it is not less...

14 CFR 23.1521 - Powerplant limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... reciprocating engines); (3) The maximum allowable gas temperature (for turbine engines); (4) The time limit for... maximum allowable gas temperature (for turbine engines); and (4) The maximum allowable cylinder head, oil... reciprocating engines), or fuel designation (for turbine engines), must be established so that it is not less...

14 CFR 23.1521 - Powerplant limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... reciprocating engines); (3) The maximum allowable gas temperature (for turbine engines); (4) The time limit for... maximum allowable gas temperature (for turbine engines); and (4) The maximum allowable cylinder head, oil... reciprocating engines), or fuel designation (for turbine engines), must be established so that it is not less...

Temperature changes in dental implants following exposure to hot substances in an ex vivo model.

PubMed

Feuerstein, Osnat; Zeichner, Kobi; Imbari, Chen; Ormianer, Zeev; Samet, Nachum; Weiss, Ervin I

2008-06-01

The habitual consumption of extremely hot foods and beverages may affect implant treatment modality. Our objectives were to: (i) establish the maximum temperature produced intra-orally while consuming very hot substances and (ii) use these values in an ex vivo model to assess the temperature changes along the implant-bone interface. Temperatures were measured using thermocouples linked to a computer. The thermocouple electrodes were attached to the tooth-gum interface of the interproximal areas in 14 volunteers during consumption of extremely hot foods and beverages. The in vivo measured temperature values obtained were used in an ex vivo model of a bovine mandible block with an implant and with an assembled abutment. Temperatures were measured by thermocouple electrodes attached to five locations, three of them along the implant-bone interface. During consumption of a hot beverage, a maximum temperature of up to 76.3 degrees C was recorded, and a calculated extreme intra-oral temperature of 61.4 degrees C was established. The ex vivo model showed a high correlation between the temperature measured at the abutment and that measured at the abutment-implant interface and inside the implant, reaching maximum temperatures close to 60 degrees C. At the mid-implant-bone and apical implant-bone interfaces, the maximum temperatures measured were 43.3 and 42 degrees C, respectively. The maximum temperatures measured at the implant-bone interfaces reached the temperature threshold of transient changes in bone (42 degrees C). The results of this study support the notion that intra-oral temperatures, developed during the consumption of very hot substances, may be capable of damaging peri-implant tissues.

Non-trivial behavior of the low temperature maximum of dielectric constant and location of the end critical point in Na0.5Bi0.5TiO3-0.06BaTiO3 lead free relaxor ferroelectrics crystals detected by acoustic emission

NASA Astrophysics Data System (ADS)

Dul'kin, Evgeniy; Tiagunova, Jenia; Mojaev, Evgeny; Roth, Michael

2018-01-01

[001] lead free relaxor ferroelectrics crystals of Na0.5Bi0.5TiO3-0.06BaTiO3 were studied by means of dielectric and acoustic emission methods in the temperature range of 25-240 °C and under a dc bias electric field up to 0.4 kV/cm. A temperature maximum of the dielectric constant was found near 170 °C, as well as the acoustic emission bursts pointed out to both the depolarization temperature near 120 °C and the temperature, corresponding to the maximum of dielectric constant, near 170 °C. While the depolarization temperature increased linearly, the temperature of the dielectric constant maximum was shown to exhibit a V-shape behavior under an electric field: it initially decreases, reaches a sharp minimum at some small threshold electric field of 0.15 kV/cm, and then starts to increase similar to the Curie temperature of the normal ferroelectrics, as the field enhances. Acoustic emission bursts, accompanying the depolarization temperature, weakened with the enhancing field, whereas the ones accompanying the temperature of the dielectric constant maximum exhibited two maxima: near 0.1 kV/cm and near 0.3 kV/cm. The meaning of these two acoustic emission maxima is discussed.

Fluid-inclusion technique for determining maximum temperature in calcite and its comparison to the vitrinite reflectance geothermometer

USGS Publications Warehouse

Barker, C.E.; Goldstein, R.H.

1990-01-01

The hypothesis that aqueous fluid inclusions in calcite can be used to establish maximum temperature (Tpeak) is tested. Fluid inclusion Th, mean random vitrinite reflectance (Rm), and present-day Tpeak from 46 diverse geologic systems that have been at Tpeak from 104 to 106 yr have been compiled. Present Tpeak ranged from 65 to 345??C, Th modes and means ranged from 59 to 350??C, and Rm data ranged from 0.4% to 4.6%, spanning the temperature and thermal maturity range associated with burial diagenesis, hydrothermal alteration, and low-grade metamorphism. Plots of Th and Tpeak data for systems thought to be currently at maximum temperature demonstrate close agreement between Th and present Tpeak in sedimentary basins. The relation suggests that Th of aqueous fluid inclusions in calcite may be a useful measure of maximum temperature. This study also compared Th to mean random vitrinite reflectance (Rm). Th correlates well with Rm and results in a curve similar to Rm vs. Tpeak calibrations determined by other workers. Strong correlation between Tpeak and Rm in these systems suggests that maximum temperature is the major control on thermal maturation. -after Authors

Modeling maximum daily temperature using a varying coefficient regression model

Treesearch

Han Li; Xinwei Deng; Dong-Yum Kim; Eric P. Smith

2014-01-01

Relationships between stream water and air temperatures are often modeled using linear or nonlinear regression methods. Despite a strong relationship between water and air temperatures and a variety of models that are effective for data summarized on a weekly basis, such models did not yield consistently good predictions for summaries such as daily maximum temperature...

A method for safety testing of radiofrequency/microwave-emitting devices using MRI.

PubMed

Alon, Leeor; Cho, Gene Y; Yang, Xing; Sodickson, Daniel K; Deniz, Cem M

2015-11-01

Strict regulations are imposed on the amount of radiofrequency (RF) energy that devices can emit to prevent excessive deposition of RF energy into the body. In this study, we investigated the application of MR temperature mapping and 10-g average specific absorption rate (SAR) computation for safety evaluation of RF-emitting devices. Quantification of the RF power deposition was shown for an MRI-compatible dipole antenna and a non-MRI-compatible mobile phone via phantom temperature change measurements. Validation of the MR temperature mapping method was demonstrated by comparison with physical temperature measurements and electromagnetic field simulations. MR temperature measurements alongside physical property measurements were used to reconstruct 10-g average SAR. The maximum temperature change for a dipole antenna and the maximum 10-g average SAR were 1.83°C and 12.4 W/kg, respectively, for simulations and 1.73°C and 11.9 W/kg, respectively, for experiments. The difference between MR and probe thermometry was <0.15°C. The maximum temperature change and the maximum 10-g average SAR for a cell phone radiating at maximum output for 15 min was 1.7°C and 0.54 W/kg, respectively. Information acquired using MR temperature mapping and thermal property measurements can assess RF/microwave safety with high resolution and fidelity. © 2014 Wiley Periodicals, Inc.

A Method for Safety Testing of Radiofrequency/Microwave-Emitting Devices Using MRI

PubMed Central

Alon, Leeor; Cho, Gene Y.; Yang, Xing; Sodickson, Daniel K.; Deniz, Cem M.

2015-01-01

Purpose Strict regulations are imposed on the amount of radiofrequency (RF) energy that devices can emit to prevent excessive deposition of RF energy into the body. In this study, we investigated the application of MR temperature mapping and 10-g average specific absorption rate (SAR) computation for safety evaluation of RF-emitting devices. Methods Quantification of the RF power deposition was shown for an MRI-compatible dipole antenna and a non–MRI-compatible mobile phone via phantom temperature change measurements. Validation of the MR temperature mapping method was demonstrated by comparison with physical temperature measurements and electromagnetic field simulations. MR temperature measurements alongside physical property measurements were used to reconstruct 10-g average SAR. Results The maximum temperature change for a dipole antenna and the maximum 10-g average SAR were 1.83° C and 12.4 W/kg, respectively, for simulations and 1.73° C and 11.9 W/kg, respectively, for experiments. The difference between MR and probe thermometry was <0.15° C. The maximum temperature change and the maximum 10-g average SAR for a cell phone radiating at maximum output for 15 min was 1.7° C and 0.54 W/kg, respectively. Conclusion Information acquired using MR temperature mapping and thermal property measurements can assess RF/microwave safety with high resolution and fidelity. PMID:25424724

On the impacts of computing daily temperatures as the average of the daily minimum and maximum temperatures

NASA Astrophysics Data System (ADS)

Villarini, Gabriele; Khouakhi, Abdou; Cunningham, Evan

2017-12-01

Daily temperature values are generally computed as the average of the daily minimum and maximum observations, which can lead to biases in the estimation of daily averaged values. This study examines the impacts of these biases on the calculation of climatology and trends in temperature extremes at 409 sites in North America with at least 25 years of complete hourly records. Our results show that the calculation of daily temperature based on the average of minimum and maximum daily readings leads to an overestimation of the daily values of 10+ % when focusing on extremes and values above (below) high (low) thresholds. Moreover, the effects of the data processing method on trend estimation are generally small, even though the use of the daily minimum and maximum readings reduces the power of trend detection ( 5-10% fewer trends detected in comparison with the reference data).

Calculation of change in brain temperatures due to exposure to a mobile phone

NASA Astrophysics Data System (ADS)

Van Leeuwen, G. M. J.; Lagendijk, J. J. W.; Van Leersum, B. J. A. M.; Zwamborn, A. P. M.; Hornsleth, S. N.; Kotte, A. N. T. J.

1999-10-01

In this study we evaluated for a realistic head model the 3D temperature rise induced by a mobile phone. This was done numerically with the consecutive use of an FDTD model to predict the absorbed electromagnetic power distribution, and a thermal model describing bioheat transfer both by conduction and by blood flow. We calculated a maximum rise in brain temperature of 0.11 °C for an antenna with an average emitted power of 0.25 W, the maximum value in common mobile phones, and indefinite exposure. Maximum temperature rise is at the skin. The power distributions were characterized by a maximum averaged SAR over an arbitrarily shaped 10 g volume of approximately 1.6 W kg-1. Although these power distributions are not in compliance with all proposed safety standards, temperature rises are far too small to have lasting effects. We verified our simulations by measuring the skin temperature rise experimentally. Our simulation method can be instrumental in further development of safety standards.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ingham, J.G.

Maximum cladding temperatures occur when the IDENT 1578 fuel pin shipping container is installed in the T-3 Cask. The maximum allowable cladding temperature of 800/sup 0/F is reached when the rate of energy deposited in the 19-pin basket reaches 400 watts. Since 45% of the energy which is generated in the fuel escapes the 19-pin basket without being deposited, mostly gamma energy, the maximum allowable rate of heat generation is 400/.55 = 727 watts. Similarly, the maximum allowable cladding temperature of 800/sup 0/F is reached when the rate of energy deposited in the 40-pin basket reaches 465 watts. Since 33%more » of the energy which is generated in the fuel escapes the 40-pin basket without being deposited, mostly gamma energy, the maximum allowable rate of heat generation is 465/.66 = 704 watts. The IDENT 1578 fuel pin shipping container therefore meets its thermal design criteria. IDENT 1578 can handle fuel pins with a decay heat load of 600 watts while maintaining the maximum fuel pin cladding temperature below 800/sup 0/F. The emissivities which were determined from the test results for the basket tubes and container are relatively low and correspond to new, shiny conditions. As the IDENT 1578 container is exposed to high temperatures for extended periods of time during the transportation of fuel pins, the emissivities will probably increase. This will result in reduced temperatures.« less

Effect of pharmacogenetic markers of vitamin D pathway on deferasirox pharmacokinetics in children.

PubMed

Allegra, Sarah; Cusato, Jessica; De Francia, Silvia; Longo, Filomena; Pirro, Elisa; Massano, Davide; Piga, Antonio; D'Avolio, Antonio

2018-01-01

Patients with β-thalassemia major have extremely low vitamin D levels, owing to reduced intestinal absorption, subicteric tint, and/or iron-induced higher pigmentation. We investigated whether some polymorphisms within the VDR, CYP24A1, CYP27B1, and GC genes could play a role in deferasirox pharmacokinetics in a cohort of pediatric patients. Eighteen children with β-thalassemia were enrolled. Drug plasma concentrations at the end of dosing interval (Ctrough) and after 0, 2, 4, 6, and 24 h of drug administration were measured by a HPLC-UV method. Allelic discrimination for VDR (TaqI, FokI, BsmI, Cdx2, and ApaI), CYP24A1 (22776, 3999 and 8620), CYP27B1 (2838 and -1260), and GC (1296) single nucleotide polymorphisms was performed by real-time PCR. CYP24A1 8620 AG/GG group negatively predicted Ctrough in regression analysis (P=0.012). ApaI AA genotype resulted as a negative predictor of Ctrough (P=0.025) and area under the concentration curve (P=0.007); FoKI CC genotype remained as area under the concentration curve positive predictor (P=0.008) and TC/CC group as half-life (t1/2) (P=0.003) and volume of distribution (Vd) (P=0.011) negative one; TaqI TC/CC was retained as a negative predictor of drug maximum concentration (Cmax) (P=0.004). Moreover, GC 1296 TG/GG seemed able to predict lower time to reach drug maximum concentration (Tmax) (P=0.033). Our preliminary experience suggested the potential usefulness of vitamin D pharmacogenetic to better understand deferasirox interindividual variability, also in pediatric patients.

Reconstruction of secular variation in seawater sulfate concentrations

NASA Astrophysics Data System (ADS)

Algeo, T. J.; Luo, G. M.; Song, H. Y.; Lyons, T. W.; Canfield, D. E.

2015-04-01

Long-term secular variation in seawater sulfate concentrations ([SO42-]SW) is of interest owing to its relationship to the oxygenation history of Earth's surface environment. In this study, we develop two complementary approaches for quantification of sulfate concentrations in ancient seawater and test their application to late Neoproterozoic (635 Ma) to Recent marine units. The "rate method" is based on two measurable parameters of paleomarine systems: (1) the S-isotope fractionation associated with microbial sulfate reduction (MSR), as proxied by Δ34SCAS-PY, and (2) the maximum rate of change in seawater sulfate, as proxied by &partial; δ 34SCAS/∂ t(max). The "MSR-trend method" is based on the empirical relationship of Δ34SCAS-PY to aqueous sulfate concentrations in 81 modern depositional systems. For a given paleomarine system, the rate method yields an estimate of maximum possible [SO42-]SW (although results are dependent on assumptions regarding the pyrite burial flux, FPY), and the MSR-trend method yields an estimate of mean [SO42-]SW. An analysis of seawater sulfate concentrations since 635 Ma suggests that [SO42-]SW was low during the late Neoproterozoic (<5 mM), rose sharply across the Ediacaran-Cambrian boundary (~5-10 mM), and rose again during the Permian (~10-30 mM) to levels that have varied only slightly since 250 Ma. However, Phanerozoic seawater sulfate concentrations may have been drawn down to much lower levels (~1-4 mM) during short (<~2 Myr) intervals of the Cambrian, Early Triassic, Early Jurassic, and Cretaceous as a consequence of widespread ocean anoxia, intense MSR, and pyrite burial. The procedures developed in this study offer potential for future high-resolution quantitative analyses of paleo-seawater sulfate concentrations.

Pharmacokinetics of Hydroxymethylnitrofurazone, a Promising New Prodrug for Chagas' Disease Treatment

PubMed Central

Serafim, Eliana Ometto Pavan; Silva, Antonio Távora de Albuquerque e; Moreno, Andréia de Haro; Vizioli, Ednir de Oliveira; Ferreira, Elizabeth Igne; Ribeiro, Maria Lucia

2013-01-01

Hydroxymethylnitrofurazone (NFOH) is a trypanocidal prodrug of nitrofurazone (NF), devoid of mutagenic toxicity. The purpose of this work was to study the chemical conversion of NFOH into NF in sodium acetate buffer (pH 1.2 and 7.4) and in human plasma and to determine preclinical pharmacokinetic parameters in rats. At pH 1.2, the NFOH was totally transformed into NF, the parent drug, after 48 h, while at pH 7.4, after the same period, the hydrolysis rate was 20%. In human plasma, 50% of NFOH was hydrolyzed after 24 h. In the investigation of kinetic disposition, the concentration of drug in serum versus time curve was used to calculate the pharmacokinetic parameters after a single-dose regimen. NFOH showed a time to maximum concentration of drug in serum (Tmax) as 1 h, suggesting faster absorption than NF (4 h). The most important results observed were the volume of distribution (V) of NFOH through the tissues, which showed a rate that is 20-fold higher (337.5 liters/kg of body weight) than that of NF (17.64 liters/kg), and the concentration of NF obtained by in vivo metabolism of NFOH, which was about four times lower (maximum concentration of drug in serum [Cmax] = 0.83 μg/ml; area under the concentration-time curve from 0 to 12 h [AUC0–12] = 5.683 μg/ml · h) than observed for administered NF (Cmax = 2.78 μg/ml; AUC0–12 = 54.49 μg/ml · h). These findings can explain the superior activity and lower toxicity of the prodrug NFOH in relation to its parent drug and confirm NFOH as a promising anti-Chagas' disease drug candidate. PMID:24080661

Sensitive and rapid liquid chromatography/tandem mass spectrometric assay for the quantification of piperaquine in human plasma.

PubMed

Singhal, Puran; Gaur, Ashwani; Gautam, Anirudh; Varshney, Brijesh; Paliwal, Jyoti; Batra, Vijay

2007-11-01

A simple, sensitive and rapid liquid chromatography/tandem mass spectrometric (LC-MS/MS) method was developed and validated for quantification of piperaquine, an antimalarial drug, in human plasma using its structural analogue, piperazine bis chloroquinoline as internal standard (IS). The method involved a simple protein precipitation with methanol followed by rapid isocratic elution of analytes with 10mM ammonium acetate buffer/methanol/formic acid/ammonia solution (25/75/0.2/0.15, v/v) on Chromolith SpeedROD RP-18e reversed phase chromatographic column and quantification by mass spectrometry in the multiple reaction monitoring mode (MRM). The precursor to product ion transitions of m/z 535.3-->288.2 and m/z 409.1-->205.2 were used to measure the analyte and the IS, respectively. The assay exhibited a linear dynamic range of 1.0-250.2 ng/mL for piperaquine in plasma. The limit of detection (LOD) and lower limit of quantification (LLOQ) in plasma were 0.2 and 1.0 ng/mL, respectively. Acceptable precision and accuracy (+/-20% deviation for LLOQ standard and +/-15% deviation for other standards from the respective nominal concentration) were obtained for concentrations over the standard curve ranges. A run time of 2.5 min for a sample made it possible to achieve a throughput of more than 400 plasma samples analyzed per day. The validated method was successfully applied to analyze human plasma samples from phase-1 clinical studies. The mean pharmacokinetic parameters of piperaquine following 1000 mg oral dose: observed maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax) and elimination half-life (T1/2) were 46.1 ng/mL, 3.8h and 13 days, respectively.

Pharmacokinetic and pharmacodynamic assessment of bioavailability for two prodrugs of methylprednisolone

PubMed Central

Daley-Yates, P. T.; Gregory, A. J.; Brooks, C. D.

1997-01-01

Aims The aim of this study was to establish whether pharmacokinetic differences between two pro-drugs of methylprednisolone (MP) are likely to be of clinical significance. Methods This study was a single-blind, randomized, crossover design comparing the bioequivalence of MP released from the pro-drugs Promedrol (MP suleptanate) and Solu-Medrol (MP succinate) after a single 250 mg (MP equivalent) intramuscular injection to 20 healthy male volunteers. Bioequivalence was assessed by conventional pharmacokinetic analysis, by measuring pharmacodynamic responses plus a novel approach using pharmacokinetic/pharmacodynamic modeling. The main measure of pharmacodynamic response was whole blood histamine (WBH), a measure of basophil numbers. Results The MP Cmax was less for MP suleptanate due to a longer absorption half-life of the prodrug from the intramuscular injection site. The bioavailability of MP was equivalent when based on AUC with a MP suleptanate median 108% of the MP succinate value (90% CI: 102–114%). For Cmax the MP suleptanate median was 81% of the MP succinate value (90% CI: 75–88%). The tmax for MP from MP suleptanate was delayed relative to MP succinate. The median difference was 200% (90% non-parametric CI: 141–283%). The area under the WBH effect-time curve (AUEC) and the maximum response (Emax ) were found to be equivalent (90% CI: 98–113% and 93–109% respectively). The maximum changes in other white blood cell counts, blood glucose concentration and the parameters of the pharmacodynamic sigmoid Emax model (EC50, Emax and γ) were also not significantly different between prodrugs. Conclusions MP suleptanate is an acceptable pharmaceutical alternative to MP succinate. The use of both pharmacokinetic and pharmacodynamic response data together gives greater confidence in the conclusions compared with those based only on conventional pharmacokinetic bioequivalence analysis. PMID:9205819

Body temperature changes are associated with outcomes following in-hospital cardiac arrest and return of spontaneous circulation.

PubMed

Suffoletto, Brian; Peberdy, Mary Anne; van der Hoek, Terry; Callaway, Clifton

2009-12-01

Spontaneous changes in body temperature after return of circulation (ROSC) from cardiac arrest are common, but the association of these changes with outcomes in hospitalized patients who survive to 24h post-ROSC is not known. We tested the hypothesis that adults who experience temperature lability in the first 24h have worse outcomes compared with those who maintain normothermia. A prospective observational study from a multicenter registry of cardiac arrests (National Registry of Cardiopulmonary Resuscitation) from 355 US and Canadian hospitals. 14,729 adults with return of circulation from a pulseless cardiac arrest. We excluded those who died or were discharged before 24h post-event, those made Do-Not-Resuscitate (DNR) within 24h of event, those that had a preceding trauma, and those with multiple cardiac arrests. Finally, we included only subjects that had both a lowest (T(min)) and highest (T(max)) body temperature value recorded during the first 24-h after ROSC, resulting in a study sample of 3426 patients. After adjustment for potential covariates, there was a lower odds of survival in those having an episode of hypothermia (adjusted odds ratio [OR], 0.62; 95% confidence interval [CI], 0.48-0.80), those having an episode of hyperthermia (OR, 0.67; 95% CI, 0.48-0.80), and those having an episode of both (OR, 0.59; 95% CI, 0.39-0.91). Among those who survived to discharge, there was also a lower odds of favorable neurologic performance in those who had an episode of hyperthermia (OR, 0.71; 95% CI, 0.51-0.98). Episodes of temperature lability following in-hospital resuscitation from cardiac arrest are associated with lower odds of surviving to discharge. Hyperthermia is also associated with fewer patients leaving the hospital with favorable neurologic performance. Further studies should identify whether therapeutic control over changes in body temperature after in-hospital cardiac arrest improves outcomes.

On the location of the maximum homogeneous crystal nucleation temperature

NASA Technical Reports Server (NTRS)

Weinberg, Michael C.

1986-01-01

Detailed considerations are given to the location of the temperature of maximum homogeneous nucleation as predicted by classical nucleation theory. It is shown quite generally that this maximum temperature, T-asterisk, must occur above the Kauzmann temperature and that the T-asterisk is such that T-asterisk is greater than T(m)/3, where T(m) is the melting temperature. Also, it is demonstrated tha T-asterisk may be considered to be approximately dependent upon two parameters: gamma, the ratio of the difference in specific heat between the crystal and liquid divided by the entropy of fusion, and E, a reduced activation energy for viscous flow. The variation of T-asterisk with these parameters is described. The relationship of the relative location of T-asterisk to the glass transition temperature, is discussed too. This discussion is couched within the framework of the strong and fragile liquid notion introduced by Angell (1981) and coworkers. Finally, the question of the ultimate limits to the undercooling of liquid metals is considered and its relationhsip to computations of the maximum nucleation temperature in such systems.

Developing a diagnostic tool for measuring maximum effective temperature within high pressure electrodeless discharges

NASA Astrophysics Data System (ADS)

Whiting, Michael; Preston, Barry; Mucklejohn, Stuart; Santos, Monica; Lister, Graeme

2016-09-01

Here we present an investigation into the feasibility of creating a diagnostic tool for obtaining maximum arc temperature measurements within a high pressure electrodeless discharge; utilizing integrating sphere measurements of optically thin lines emitted from mercury atoms within commercially available high pressure mercury lamp arc tubes. The optically thin lines chosen were 577 nm and 1014 nm from a 250 W high pressure mercury lamp operated at various powers. The effective temperature could be calculated by considering the relative intensities of the two optically thin lines and comparison with the theoretical ratio of the temperature dependent power emitted from the lines derived from the atomic spectral data provided by NIST. The calculations gave effective arc temperatures of 5755, 5804 and 5820 K at 200, 225, 250 W respectively. This method was subsequently used as a basis for determining maximum effective arc temperature within microwave-driven electrodeless discharge capsules, with varying mercury content of 6.07, 9.4 and 12.95 mg within 1 × 10-6 m3 giving maximum effective temperatures of 5163, 4768 and 4715 K respectively at 240 W.

Possible combined influences of absorbing aerosols and anomalous atmospheric circulation on summertime diurnal temperature range variation over the middle and lower reaches of the Yangtze River

NASA Astrophysics Data System (ADS)

Cai, Jiaxi; Guan, Zhaoyong; Ma, Fenhua

2016-12-01

Based on the temperature data from the China Meteorological Administration, NCEP-NCAR reanalysis data, and the TOMS Aerosol Index (AI), we analyze the variations in the summertime diurnal temperature range (DTR) and temperature maxima in the middle and lower reaches of the Yangtze River (MLRYR) in China. The possible relationships between the direct warming effect of the absorbing aerosol and temperature variations are further investigated, although with some uncertainties. It is found that the summertime DTR exhibits a decreasing trend over the most recent 50 years, along with a slight increasing tendency since the 1980s. The trend of the maximum temperature is in agreement with those of the DTR and the absorbing aerosols. To investigate the causes of the large anomalies in the temperature maxima, composite analyses of the circulation anomalies are performed. When anomalous AI and anomalous maximum temperature over the MLRYR have the same sign, an anomalous circulation with a quasi-barotropic structure occurs there. This anomalous circulation is modulated by the Rossby wave energy propagations from the regions northwest of the MLRYR and influences the northwestern Pacific subtropical high over the MLRYR. In combination with aerosols, the anomalous circulation may increase the maximum temperature in this region. Conversely, when the anomalous AI and anomalous maximum temperature in the MLRYR have opposite signs, the anomalous circulation is not equivalently barotropic, which possibly offsets the warming effect of aerosols on the maximum temperature changes in this region. These results are helpful for a better understanding of the DTR changes and the occurrences of temperature extremes in the MLRYR region during boreal summer.

40 CFR 60.37e - Compliance, performance testing, and monitoring guidelines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... requirements: (1) Establish maximum charge rate and minimum secondary chamber temperature as site-specific... above the maximum charge rate or below the minimum secondary chamber temperature measured as 3-hour... below the minimum secondary chamber temperature shall constitute a violation of the established...

Assessing the outstanding 2003 fire events in Portugal with a Regional Climate Model

NASA Astrophysics Data System (ADS)

Trigo, Ricardo; Jerez, Sonia; Camara, Carlos; Montávez, Juan Pedro

2013-04-01

The heatwave that struck western Iberia in the early days of August 2003 was characterized by record high values of both maximum (47.3°C) and minimum (30.6°c) temperatures in Portugal, associated with extremely low humidity levels and relatively intense wind speed (Trigo et al., 2006). These conditions triggered the most devastating sequence of large fires ever registered in Portugal. The estimated total burnt area was about 450.000 ha, including 280.000 ha of forest (Pereira et al., 2011). The outstanding total burnt area value corresponds to roughly 5% of the Portuguese territory, and represents approximately twice the previous maximum observed in 1998 (~220.000 ha), and about four times the long-term average observed between 1980 and 2004. Here we characterise this unusual episode using meteorological fields obtained from both observations and a regional climate model. In this work we use the longest (49-years) high-resolution regional climate simulation available driven by reanalysis data spanning from 1959 to 2007 and covering the entire Iberian Peninsula. This long run was obtained using the MM5 model with a spatial resolution of 10 km. Using this high spatial and temporal resolution we have computed the Canadian Fire Weather Index (FWI) System to produce hourly values of fire risk. The FWI System consists of six components that account for the effects of fuel moisture and wind on fire behaviour (van Wagner, 1987). We show the temporal evolution of high resolution patterns for several fire related variables during the most important days for triggering new fires (the first week of August 2003). Besides the absolute value of Tmax, Tmin, wind (speed and direction), relative humidity and FWI we also evaluate the corresponding anomalies of these fields, obtained after removing the long-term smoothed daily climatology. Pereira M.G., Malamude B.D., Trigo R.M., Alves P.I. (2011) "The History and Characteristics of the 1980-2005 Portuguese Rural Fire Database". Natural Hazards and Earth System Sciences. 11, 3343-3358, doi:10.5194/nhess-11-3343-2011 Trigo R.M., Pereira J.M.C., Pereira M.G., Mota B., Calado M.T., DaCamara C.C., Santo F.E. (2006) "The exceptional fire season of summer 2003 in Portugal". International Journal of Climatology, 26 (13): 1741-1757 NOV 15 2006. Van Wagner, C.E., 1987. Development and structure of the Canadian forest fire weather index system. Canadian Forestry Service, Forest Technical Report 35, Ottawa, 37 pp.

Preliminary analysis of hot spot factors in an advanced reactor for space electric power systems

NASA Technical Reports Server (NTRS)

Lustig, P. H.; Holms, A. G.; Davison, H. W.

1973-01-01

The maximum fuel pin temperature for nominal operation in an advanced power reactor is 1370 K. Because of possible nitrogen embrittlement of the clad, the fuel temperature was limited to 1622 K. Assuming simultaneous occurrence of the most adverse conditions a deterministic analysis gave a maximum fuel temperature of 1610 K. A statistical analysis, using a synthesized estimate of the standard deviation for the highest fuel pin temperature, showed probabilities of 0.015 of that pin exceeding the temperature limit by the distribution free Chebyshev inequality and virtually nil assuming a normal distribution. The latter assumption gives a 1463 K maximum temperature at 3 standard deviations, the usually assumed cutoff. Further, the distribution and standard deviation of the fuel-clad gap are the most significant contributions to the uncertainty in the fuel temperature.

System for Repairing Cracks in Structures

NASA Technical Reports Server (NTRS)

Smith, Stephen W. (Inventor); Newman, John A. (Inventor); Piascik, Robert S. (Inventor); Glaessgen, Edward H. (Inventor)

2014-01-01

A first material with a known maximum temperature of operation is coated with a second material on at least one surface of the first material. The coating has a melting temperature that is greater than the maximum temperature of operation of the first material. The coating is heated to its melting temperature until the coating flows into any cracks in the first material's surface.

Thermal management improvement of an air-cooled high-power lithium-ion battery by embedding metal foam

NASA Astrophysics Data System (ADS)

Mohammadian, Shahabeddin K.; Rassoulinejad-Mousavi, Seyed Moein; Zhang, Yuwen

2015-11-01

Effect of embedding aluminum porous metal foam inside the flow channels of an air-cooled Li-ion battery module was studied to improve its thermal management. Four different cases of metal foam insert were examined using three-dimensional transient numerical simulations. The effects of permeability and porosity of the porous medium as well as state of charge were investigated on the standard deviation of the temperature field and maximum temperature inside the battery in all four cases. Compared to the case of no porous insert, embedding aluminum metal foam in the air flow channel significantly improved the thermal management of Li-ion battery cell. The results also indicated that, decreasing the porosity of the porous structure decreases both standard deviation of the temperature field and maximum temperature inside the battery. Moreover, increasing the permeability of the metal foam drops the maximum temperature inside the battery while decreasing this property leads to improving the temperature uniformity. Our results suggested that, among the all studied cases, desirable temperature uniformity and maximum temperature were achieved when two-third and the entire air flow channel is filled with aluminum metal foam, respectively.

Pharmacokinetic study of nobiletin and tangeretin in rat serum by high-performance liquid chromatography-electrospray ionization-mass spectrometry.

PubMed

Manthey, John A; Cesar, Thais B; Jackson, Erin; Mertens-Talcott, Susanne

2011-01-12

Nobiletin (NOB) and tangeretin (TAN), two of the main polymethoxylated flavones (PMFs) in citrus, influence a number of key biological pathways in mammalian cells. Although the impacts of NOB and TAN on glucose homeostasis and cholesterol regulation have been investigated in human clinical trials, much information is still lacking about the metabolism and oral bioavailability of these compounds in animals. In this study, NOB and TAN were administered to rats by gavage and intraperitoneal (ip) injection, and the blood serum concentrations of these compounds and their main metabolites were monitored by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). In addition to the administered compounds, two metabolites of TAN and eight metabolites of NOB were detected and measured over 24 h. With identical oral doses, nearly 10-fold higher absorption of NOB occurred compared to TAN. For both compounds, maximum levels of glucuronidated metabolites occurred in the blood serum at later time points (∼5-8 h) compared to the earlier T(max) values for NOB and TAN. In most cases the glucuronides occurred at substantially higher concentrations than the aglycone metabolites. Low levels of NOB and TAN and their metabolites were detectable in rat blood serum even at 24 h after treatment.

Aluminum bioavailability from basic sodium aluminum phosphate, an approved food additive emulsifying agent, incorporated in cheese

PubMed Central

Yokel, Robert A.; Hicks, Clair L.; Florence, Rebecca L.

2008-01-01

Oral aluminum (Al) bioavailability from drinking water has been previously estimated, but there is little information on Al bioavailability from foods. It was suggested that oral Al bioavailability from drinking water is much greater than from foods. The objective was to further test this hypothesis. Oral Al bioavailability was determined in the rat from basic [26Al]-sodium aluminum phosphate (basic SALP) in a process cheese. Consumption of ~ 1 gm cheese containing 1.5 or 3% basic SALP resulted in oral Al bioavailability (F) of ~ 0.1 and 0.3%, respectively, and time to maximum serum 26Al concentration (Tmax) of 8 to 9 h. These Al bioavailability results were intermediate to previously reported results from drinking water (F ~ 0.3%) and acidic-SALP incorporated into a biscuit (F ~ 0.1%), using the same methods. Considering the similar oral bioavailability of Al from food vs. water, and their contribution to the typical human’s daily Al intake (~ 95 and 1.5%, respectively), these results suggest food contributes much more Al to systemic circulation, and potential Al body burden, than does drinking water. These results do not support the hypothesis that drinking water provides a disproportionate contribution to total Al absorbed from the gastrointestinal tract. PMID:18436363

Aluminum bioavailability from basic sodium aluminum phosphate, an approved food additive emulsifying agent, incorporated in cheese.

PubMed

Yokel, Robert A; Hicks, Clair L; Florence, Rebecca L

2008-06-01

Oral aluminum (Al) bioavailability from drinking water has been previously estimated, but there is little information on Al bioavailability from foods. It was suggested that oral Al bioavailability from drinking water is much greater than from foods. The objective was to further test this hypothesis. Oral Al bioavailability was determined in the rat from basic [26Al]-sodium aluminum phosphate (basic SALP) in a process cheese. Consumption of approximately 1g cheese containing 1.5% or 3% basic SALP resulted in oral Al bioavailability (F) of approximately 0.1% and 0.3%, respectively, and time to maximum serum 26Al concentration (Tmax) of 8-9h. These Al bioavailability results were intermediate to previously reported results from drinking water (F approximately 0.3%) and acidic-SALP incorporated into a biscuit (F approximately 0.1%), using the same methods. Considering the similar oral bioavailability of Al from food vs. water, and their contribution to the typical human's daily Al intake ( approximately 95% and 1.5%, respectively), these results suggest food contributes much more Al to systemic circulation, and potential Al body burden, than does drinking water. These results do not support the hypothesis that drinking water provides a disproportionate contribution to total Al absorbed from the gastrointestinal tract.

Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities.

PubMed

Davis, Robert E; Hondula, David M; Patel, Anjali P

2016-06-01

Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat-mortality relationships. We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature-mortality relationships were associated with maximum temperature, although mean temperature results were comparable. There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature-mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum temperatures in most cities we examined, particularly those typically prone to heat-related mortality. Davis RE, Hondula DM, Patel AP. 2016. Temperature observation time and type influence estimates of heat-related mortality in seven U.S. cities. Environ Health Perspect 124:795-804; http://dx.doi.org/10.1289/ehp.1509946.

40 CFR Table 4 to Subpart Ooo of... - Operating Parameter Levels

Code of Federal Regulations, 2011 CFR

2011-07-01

... specific gravity Condenser Exit temperature Maximum temperature Carbon absorber Total regeneration steam or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum...

40 CFR Table 4 to Subpart Ooo of... - Operating Parameter Levels

Code of Federal Regulations, 2013 CFR

2013-07-01

... specific gravity Condenser Exit temperature Maximum temperature Carbon absorber Total regeneration steam or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum...

40 CFR Table 4 to Subpart Ooo of... - Operating Parameter Levels

Code of Federal Regulations, 2014 CFR

2014-07-01

... specific gravity Condenser Exit temperature Maximum temperature Carbon absorber Total regeneration steam or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum...

Evaluating the Energy Recovery Potential of Nigerian Coals under Non-Isothermal Thermogravimetry

NASA Astrophysics Data System (ADS)

Bevan Nyakuma, Bemgba; Oladokun, Olagoke; Jauro, Aliyu; Damian Nyakuma, Denen

2017-07-01

This study investigated the fuel properties and energy recovery potential of two coal samples from Ihioma (IHM) and Ogboligbo (OGB) environs in Nigeria. The ultimate, proximate, and bomb calorimetric analyses of the coal were examined. Next, the rank classification and potential application of the coals were evaluated according to the ASTM standard D388. Lastly, thermal decomposition behaviour was examined by non-isothermal thermogravimetry (TG) under pyrolysis conditions from 30 - 900 °C. The results indicated IHM and OGB contain high proportions of combustible elements for potential thermal conversion. The higher heating value (HHV) of IHM was 20.37 MJ/kg whereas OGB was 16.33 MJ/kg. TG analysis revealed 55% weight loss for OGB and 76% for IHM. The residual mass was 23% for IHM and 44% for OGB. Based on the temperature profile characteristics (TPCs); Ton , Tmax , and Toff , IHM was more reactive than OGB due to its higher volatile matter (VM). Overall, results revealed the coals are Lignite (Brown) low-rank coals (LRCs) with potential for electric power generation.

On ultraviolet freeze-in dark matter during reheating

NASA Astrophysics Data System (ADS)

Chen, Shao-Long; Kang, Zhaofeng

2018-05-01

The absence of any confirmative signals from extensive DM searching motivates us to go beyond the conventional WIMPs scenario. The feebly interacting massive particles (FIMPs) paradigm provides a good alternative which, despite of its feebly interaction with the thermal particles, still could correctly produce relic abundance without conventional DM signals. The Infrared-FIMP based on the renormalizable operators is usually suffering the very tiny coupling drawback, which can be overcome in the UltraViolet-FIMP scenario based on high dimensional effective operators. However, it is sensitive to the history of the very early Universe. The previous works terminates this sensitivity at the reheating temperature TRH. We, motivated by its UV-sensitivity, investigate the effects from the even earlier Universe, reheating era. We find that in the usual case with TRHgg mDM, the production rate during reheating is very small as long as the effective operators dimension d <= 8. Besides, we consider the contribution from the mediator, which may be produced during reheating. Moreover, we study the situation when TRH is even lower than mDM and DM can be directly produced during reheating if its mass does not exceed TMAX.

Physicochemical characterization of diclofenac sodium-loaded poloxamer gel as a rectal delivery system with fast absorption.

PubMed

Yong, Chul Soon; Sah, Hongkee; Jahng, Yurngdong; Chang, Hyeun Wook; Son, Jong-Keun; Lee, Seung Ho; Jeong, Tae Cheon; Rhee, Jong-Dal; Baek, Suk Hwan; Kim, Chong-Kook; Choi, Han-Gon

2003-05-01

Rectal poloxamer gel systems composed of poloxamers and bioadhesive polymers were easy to administer to the anus and were mucoadhesive to the rectal tissues without leakage after the dose. However, a poloxamer gel containing diclofenac sodium could not be developed using bioadhesive polymers, since the drug was precipitated in this preparation. To develop a poloxamer gel using sodium chloride instead of bioadhesive polymers, the physicochemical properties such as gelation temperature, gel strength, and bioadhesive force of various formulations composed of diclofenac sodium, poloxamers, and sodium chloride were investigated. Furthermore, the pharmacokinetic study of diclofenac sodium delivered by the poloxamer gel was performed. Diclofenac sodium significantly increased the gelation temperature and weakened the gel strength and bioadhesive force, while sodium chloride did the opposite. The poloxamer gels with less than 1.0% sodium chloride, in which the drug was not precipitated, were inserted into the rectum without difficulty and leakage, and were retained in the rectum of rats for at least 6 hr. Furthermore, poloxamer gel gave significantly higher initial plasma concentrations and faster Tmax of diclofenac sodium than did solid suppository, indicating that drug from poloxamer gel could be absorbed faster than that from the solid one in rats. Our results suggested that a rectal poloxamer gel system with sodium chloride and poloxamers was a more physically stable, convenient, and effective rectal dosage form for diclofenac sodium.

Fishing and bottom water temperature as drivers of change in maximum shell length in Atlantic surfclams (Spisula solidissima)

NASA Astrophysics Data System (ADS)

Munroe, D. M.; Narváez, D. A.; Hennen, D.; Jacobson, L.; Mann, R.; Hofmann, E. E.; Powell, E. N.; Klinck, J. M.

2016-03-01

Maximum shell length of Atlantic surfclams (Spisula solidissima) on the Middle Atlantic Bight (MAB) continental shelf, obtained from federal fishery survey data from 1982-present, has decreased by 15-20 mm. Two potential causes of this decreasing trend, fishery removal of large animals and stress due to warming bottom temperatures, were investigated using an individual-based model for post-settlement surfclams and a fifty-year hindcast of bottom water temperatures on the MAB. Simulations showed that fishing and/or warming bottom water temperature can cause decreases in maximum surfclam shell length (body size) equivalent to those observed in the fished stock. Independently, either localized fishing rates of 20% or sustained bottom temperatures that are 2 °C warmer than average conditions generate the observed decrease in maximum shell length. However, these independent conditions represent extremes and are not sustained in the MAB. The combined effects of fishing and warmer temperatures can generate simulated length decreases that are similar to observed decreases. Interannual variability in bottom water temperatures can also generate fluctuations in simulated shell length of up to 20 mm over a period of 10-15 years. If the change in maximum size is not genotypic, simulations also suggest that shell size composition of surfclam populations can recover if conditions change; however, that recovery could take a decade to become evident.

Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities

PubMed Central

Davis, Robert E.; Hondula, David M.; Patel, Anjali P.

2015-01-01

Background: Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat–mortality relationships. Objectives: We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Methods: Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. Results: In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature–mortality relationships were associated with maximum temperature, although mean temperature results were comparable. Conclusions: There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature–mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum temperatures in most cities we examined, particularly those typically prone to heat-related mortality. Citation: Davis RE, Hondula DM, Patel AP. 2016. Temperature observation time and type influence estimates of heat-related mortality in seven U.S. cities. Environ Health Perspect 124:795–804; http://dx.doi.org/10.1289/ehp.1509946 PMID:26636734

A New Method to Measure Temperature and Burner Pattern Factor Sensing for Active Engine Control

NASA Technical Reports Server (NTRS)

Ng, Daniel

1999-01-01

The determination of the temperatures of extended surfaces which exhibit non-uniform temperature variation is very important for a number of applications including the "Burner Pattern Factor" (BPF) of turbine engines. Exploratory work has shown that use of BPF to control engine functions can result in many benefits, among them reduction in engine weight, reduction in operating cost, increase in engine life, while attaining maximum engine efficiency. Advanced engines are expected to operate at very high temperature to achieve high efficiency. Brief exposure of engine components to higher than design temperatures due to non-uniformity in engine burner pattern can reduce engine life. The engine BPF is a measure of engine temperature uniformity. Attainment of maximum temperature uniformity and high temperatures is key to maximum efficiency and long life. A new approach to determine through the measurement of just one radiation spectrum by a multiwavelength pyrometer is possible. This paper discusses a new temperature sensing approach and its application to determine the BPF.

May–June Maximum Temperature Reconstruction from Mean Earlywood Density in North Central China and Its Linkages to the Summer Monsoon Activities

PubMed Central

Chen, Feng; Yuan, Yujiang

2014-01-01

Cores of Pinus tabulaformis from Tianshui were subjected to densitometric analysis to obtain mean earlywood density data. Climate response analysis indicates that May–June maximum temperature is the main factor limiting the mean earlywood density (EWD) of Chinese pine trees in the Shimen Mountains. Based on the EWD chronology, we have reconstructed May–June maximum temperature 1666 to 2008 for Tianshui, north central China. The reconstruction explains 40.1% of the actual temperature variance during the common period 1953–2008. The temperature reconstruction is representative of temperature conditions over a large area to the southeast and northwest of the sampling site. Preliminary analysis of links between large-scale climatic variation and the temperature reconstruction shows that there is a relationship between extremes in spring temperature and anomalous atmospheric circulation in the region. It is thus revealed that the mean earlywood density chronology of Pinus tabulaformis has enough potential to reconstruct the temperature variability further into the past. PMID:25207554

Estimating Long-Term Survival Temperatures at the Assemblage Level in the Marine Environment: Towards Macrophysiology

PubMed Central

Richard, Joëlle; Morley, Simon Anthony; Thorne, Michael A. S.; Peck, Lloyd Samuel

2012-01-01

Defining ecologically relevant upper temperature limits of species is important in the context of environmental change. The approach used in the present paper estimates the relationship between rates of temperature change and upper temperature limits for survival in order to evaluate the maximum long-term survival temperature (Ts). This new approach integrates both the exposure time and the exposure temperature in the evaluation of temperature limits. Using data previously published for different temperate and Antarctic marine environments, we calculated Ts in each environment, which allowed us to calculate a new index: the Warming Allowance (WA). This index is defined as the maximum environmental temperature increase which an ectotherm in a given environment can tolerate, possibly with a decrease in performance but without endangering survival over seasonal or lifetime time-scales. It is calculated as the difference between maximum long-term survival temperature (Ts) and mean maximum habitat temperature. It provides a measure of how close a species, assemblage or fauna are living to their temperature limits for long-term survival and hence their vulnerability to environmental warming. In contrast to data for terrestrial environments showing that warming tolerance increases with latitude, results here for marine environments show a less clear pattern as the smallest WA value was for the Peru upwelling system. The method applied here, relating upper temperature limits to rate of experimental warming, has potential for wide application in the identification of faunas with little capacity to survive environmental warming. PMID:22509340

Pharmacokinetic properties and safety profile of histamine dihydrochloride injection in Chinese healthy volunteers: a phase I, single-center, open-label, randomized study.

PubMed

Li, Jiapeng; Huang, Xiaojun; Wang, Qian; Jing, Shan; Jiang, Hao; Wei, Zhongna; Zang, Yannan; Liu, Yang; Zhao, Libo; Fang, Yi; Feng, Wanyu

2015-10-01

Histamine dihydrochloride (HDC) injection has been approved in Europe for the treatment of adults with acute myeloid leukemia, used in combination therapy with the T-cell-derived cytokine interleukin-2. Despite years of clinical applications of HDC in Europe, no data are available on its tolerability and pharmacokinetic properties in Chinese patients. The objective of this study was to determine the safety profile and pharmacokinetic properties of HDC in Chinese healthy volunteers (HVs). In this Phase I, single-center, open-label, randomized study, 20 Chinese HVs were randomized to receive a single dose of 0.5 or 1.0 mg HDC via a 10-minute subcutaneous injection. Whole-blood and urine samples were collected at designated time points after dosing. Plasma and urine concentrations of histamine and metabolite N-methyl histamine were measured using a validated HPLC-MS/MS method. Pharmacokinetic parameters were estimated through noncompartmental procedures based on concentration-time data. Adverse events and evaluation of clinical laboratory tests were used to assess the safety profile. The pharmacokinetic profile for a single-dose of 1.0 mg HDC in Chinese HVs was compared with that in Western HVs. No severe adverse events occurred in this study, and the severity of all adverse events was grade I according to the Common Terminology Criteria for Adverse Events, version 4.0. For the pharmacokinetic parameters of histamine at the 0.5-mg and 1.0-mg dose levels, t½ was 0.50 and 1.02 hours; Tmax was 0.15 and 0.14 hours; mean Cmax was 26.59 and 71.01 nmol/L; AUC0-t was 8.35 and 20.43 nmol/h/L; AUC0-∞ was 9.61 and 22.69 nmol/h/L; accumulated amount excreted in urine within 24 hours was 125.93 and 145.52 nmol; and maximum urine excretion rates were 21.85 and 38.94 nmol/h, respectively. For N-methyl histamine at the 0.5-mg and 1.0-mg dose levels, t½ was 0.58 and 0.66 hours; Tmax was 0.28 and 0.26 hours; mean Cmax was 17.01 and 23.54 nmol/L; AUC0-t was 7.72 and 17.08 nmol/h/L; AUC0-∞ was 9.01 and 19.62 nmol/h/L; accumulated amount excreted in urine within 24 hours was 331.7 and 583.21 nmol; and maximum urine excretion rates were 53.29 and 133.53 nmol/h, respectively. Both single-dose 0.5 mg and 1.0 mg HDC were well tolerated in Chinese HVs, and the pharmacokinetic profile of HDC in Chinese HVs was characterized in this study. A single dose of 1.0 mg HDC had a more rapid but similar extent of absorption, a wider distribution, and a little more rapid elimination in Chinese HVs compared with Western HVs. Findings from this study support additional clinical trials for HDC using in Chinese patients. Chinese Clinical Trial Registry identifier: ChiCTR-ONC-13003954. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

Metabolism, distribution and elimination of lisdexamfetamine dimesylate: open-label, single-centre, phase I study in healthy adult volunteers.

PubMed

Krishnan, Suma M; Pennick, Michael; Stark, Jeffrey G

2008-01-01

Attention-deficit/hyperactivity disorder (ADHD) in children often persists into adulthood and is potentially associated with significant social and occupational impairments. It is important to understand the effects of pharmacological treatments of ADHD in adults. This study aimed to assess the absorption, metabolism and elimination of lisdexamfetamine dimesylate in normal, healthy adult subjects following a single oral dose. A secondary objective was to assess the safety and tolerability of treatment. In an open-label, single-centre study, six healthy adult volunteers aged 22-52 years received a single oral 70 mg dose of (14)C-radiolabelled lisdexamfetamine dimesylate in solution following a 10-hour fast. Blood samples drawn pre-dose and at time points up to 120 hours post-dose were used for plasma pharmacokinetic analysis of the active d-amphetamine and the intact parent compound lisdexamfetamine dimesylate. Recovery of radioactivity was determined by liquid scintillation counting of blood samples (whole blood and plasma), urine samples and faecal samples collected pre-dose and at designated time points up to 120 hours post-dose. Urine samples were also analysed for the presence of amphetamine-derived metabolites. Safety was assessed by adverse event reporting, changes in physical findings, vital sign measurements, ECG measurements, and clinical laboratory test results. For intact lisdexamfetamine dimesylate, the median time to reach maximum plasma drug concentration (t(max)) was 1.00 hour, and the mean maximum plasma drug concentration (C(max)) was 58.2 +/- 28.1 ng/mL. Intact lisdexamfetamine dimesylate exhibited modest systemic exposure (area under the drug concentration-time curve from time 0 to infinity [AUC(infinity)] 67.04 +/- 18.94 ng . h/mL), and rapid elimination (mean apparent terminal elimination half-life [t((1/2)beta)] 0.47 hours). For d-amphetamine, the median t(max) was 3.00 hours, and the mean C(max) was 80.3 +/- 11.8 ng/mL. The AUC(infinity) of d-amphetamine was 1342 +/- 216.9 ng . h/mL, and elimination occurred as a first-order process. The t((1/2)beta) of d-amphetamine was 10.39 hours. Peaks consistent with amphetamine and hippuric acid were identified in urine samples by high-performance liquid chromatography radioactive profiling. Relative to dose administered, 41.5% was recovered in urine as d-amphetamine, 24.8% as hippuric acid and 2.2% as intact lisdexamfetamine dimesylate. Less than 0.3% of the administered dose was recovered in the faeces. During the 0- to 48-hour urine samples, no unexpected adverse events or clinically significant laboratory, ECG or physical examination findings related to the study medication were observed. Following a single 70 mg oral dose, lisdexamfetamine dimesylate was quickly absorbed, extensively metabolized to d-amphetamine and its derivatives, and rapidly eliminated. Systemic exposure to d-amphetamine was approximately 20-fold higher than systemic exposure to intact lisdexamfetamine dimesylate in healthy adults. Lisdexamfetamine dimesylate, administered as a single 70 mg dose, was generally well tolerated in this study.

Predicting tropical cyclone intensity using satellite measured equivalent blackbody temperatures of cloud tops. [regression analysis

NASA Technical Reports Server (NTRS)

Gentry, R. C.; Rodgers, E.; Steranka, J.; Shenk, W. E.

1978-01-01

A regression technique was developed to forecast 24 hour changes of the maximum winds for weak (maximum winds less than or equal to 65 Kt) and strong (maximum winds greater than 65 Kt) tropical cyclones by utilizing satellite measured equivalent blackbody temperatures around the storm alone and together with the changes in maximum winds during the preceding 24 hours and the current maximum winds. Independent testing of these regression equations shows that the mean errors made by the equations are lower than the errors in forecasts made by the peristence techniques.

Future Temperatures and Precipitations in the Arid Northern-Central Chile: A Multi-Model Downscaling Approach

NASA Astrophysics Data System (ADS)

Souvignet, M.; Heinrich, J.

2010-03-01

Downscaling of global climate outputs is necessary to transfer projections of potential climate change scenarios to local levels. This is of special interest to dry mountainous areas, which are particularly vulnerable to climate change due to risks of reduced freshwater availability. These areas play a key role for hydrology since they usually receive the highest local precipitation rates stored in form of snow and glaciers. In the central-northern Chile (Norte Chico, 26-33ºS), where agriculture still serves as a backbone of the economy as well as ensures the well being of people, the knowledge of water resources availability is essential. The region is characterised by a semiarid climate with a mean annual precipitation inferior to 100mm. Moreover, the local climate is also highly influenced by the ENSO phenomenon, which accounts for the strong inter-annual variability in precipitation patterns. Although historical and spatially extensive precipitation data in the headwaters of the basins in this region are not readily available, records at coastal stations show worrisome trends. For instance, the average precipitation in La Serena, the most important city located in the Coquimbo Region, has decreased dramatically in the past 100 years. The 30-year monthly average has decreased from 170 mm in the early 20th century to values less than 80 mm nowadays. Climate Change is expected to strengthen this pattern in the region, and therefore strongly influence local hydrological patterns. The objectives of this study are i) to develop climate change scenarios (2046-2099) for the Norte Chico using multi-model predictions in terms of temperatures and precipitations, and ii) to compare the efficiency of two downscaling techniques in arid mountainous regions. In addition, this study aims at iii) providing decision makers with sound analysis of potential impact of Climate Change on streamflow in the region. For the present study, future local climate scenarios were developed for maximum, minimum temperature and precipitation in the research area based on four different General Circulation Models (GCMs). On the first hand, the Statistical Downscaling Model (SDSM) was used. This model is based on a multiple linear regression method and is best described as a hybrid of the stochastic weather generator and transfer function methods. One common advantage of statistical downscaling is that it ensures the maintenance of local spatial and temporal variability in generating realistic data time series. On the other hand and for comparison purposes, the Change Factor method was used. This methodology is relatively straightforward and ideal for rapid climate change assessment. The outputs of the HadCM3, CGCM3.1, GDFL-CM2 and MRI-CGCM2.3.2 A1 and B2 scenarios were downscaled with both methodologies and thereafter compared by means of several hydro-meteorological indices for a 55-years period (2045-2099). Preliminary results indicate that local temperatures are expected to rise in the region, whereas precipitations may decrease. However, minimum and maximum temperatures might increase at a faster rate at higher altitude areas. In addition, the Cordillera mountain range may encounter and longer winters with a dramatic decrease of icing days (Tmax<0°C). As for precipitation, both SRES scenarios for all models return a diminishing tendency, though the A2 scenario results show a faster decrease rate. Results indicate potential strong inter-seasonal and inter-annual perturbations in Rainfall in the region. Consequently, the Norte Chico will possibly see its streamflow strongly impacted with a resulting high variability at the seasonal and inter-annual level. A probabilistic analysis of the projections of the four GCMs provided a better representation of uncertainties linked with downscaled scenarios. Whereas maximum and minimum temperatures were accurately simulated by both downscaling methods, precipitation simulations returned weaker results. SDSM proved to have a poor ability to simulate extreme rainfall events and few conclusions could be drawn with respect to future occurrences of ENSO phenomena. On the other hand, the change factor method reproduced comparatively better historical precipitations. Despite all sources of error and uncertainties, which must be taken into account when handling the projections, this study addresses an issue that goes beyond local concerns and aims at developing a better understanding of impacts of climate change in fragile environments such as the arid and semiarid transition zone of north-central Chile. Its additional applied component goes therefore beyond the classical comparative study and aims at supporting stakeholders in their processes of decision making.

Prediction of Tissue Outcome and Assessment of Treatment Effect in Acute Ischemic Stroke Using Deep Learning.

PubMed

Nielsen, Anne; Hansen, Mikkel Bo; Tietze, Anna; Mouridsen, Kim

2018-06-01

Treatment options for patients with acute ischemic stroke depend on the volume of salvageable tissue. This volume assessment is currently based on fixed thresholds and single imagine modalities, limiting accuracy. We wish to develop and validate a predictive model capable of automatically identifying and combining acute imaging features to accurately predict final lesion volume. Using acute magnetic resonance imaging, we developed and trained a deep convolutional neural network (CNN deep ) to predict final imaging outcome. A total of 222 patients were included, of which 187 were treated with rtPA (recombinant tissue-type plasminogen activator). The performance of CNN deep was compared with a shallow CNN based on the perfusion-weighted imaging biomarker Tmax (CNN Tmax ), a shallow CNN based on a combination of 9 different biomarkers (CNN shallow ), a generalized linear model, and thresholding of the diffusion-weighted imaging biomarker apparent diffusion coefficient (ADC) at 600×10 -6 mm 2 /s (ADC thres ). To assess whether CNN deep is capable of differentiating outcomes of ±intravenous rtPA, patients not receiving intravenous rtPA were included to train CNN deep, -rtpa to access a treatment effect. The networks' performances were evaluated using visual inspection, area under the receiver operating characteristic curve (AUC), and contrast. CNN deep yields significantly better performance in predicting final outcome (AUC=0.88±0.12) than generalized linear model (AUC=0.78±0.12; P =0.005), CNN Tmax (AUC=0.72±0.14; P <0.003), and ADC thres (AUC=0.66±0.13; P <0.0001) and a substantially better performance than CNN shallow (AUC=0.85±0.11; P =0.063). Measured by contrast, CNN deep improves the predictions significantly, showing superiority to all other methods ( P ≤0.003). CNN deep also seems to be able to differentiate outcomes based on treatment strategy with the volume of final infarct being significantly different ( P =0.048). The considerable prediction improvement accuracy over current state of the art increases the potential for automated decision support in providing recommendations for personalized treatment plans. © 2018 American Heart Association, Inc.

Gender Difference of Gastric Emptying in Healthy Volunteers and Patients with Functional Dyspepsia.

PubMed

Mori, Hideki; Suzuki, Hidekazu; Matsuzaki, Juntaro; Taniguchi, Kanami; Shimizu, Toshiyuki; Yamane, Tsuyoshi; Masaoka, Tatsuhiro; Kanai, Takanori

2017-01-01

Delayed gastric emptying is one of the reasons why functional dyspepsia (FD) occurs. The 13C-acetate breath test is widely used to evaluate gastric emptying. Nevertheless, the standard value of 13C-acetate breath test has not taken into account the gender difference of gastric emptying among healthy individuals. The main aim of this study was to readjust the standard value of 13C-acetate breath test in the light of gender differences. In addition, we clarified the prevalence and clinical characteristics of delayed gastric emptying in patients with FD using the modified standard values of 13C-acetate breath test. Fifty-two healthy individuals and 126 patients with patients with FD were enrolled. Gastric emptying was evaluated by the 13C-acetate breath test. The cut-off points of Tmax for the diagnosis of delayed gastric emptying were determined on the basis of results from healthy individuals making a distinction of genders. Gastroesophageal reflux symptoms, dyspeptic symptoms, scores of anxiety and depression, age, body mass index (BMI), smoking and alcohol consumption were compared between the delayed gastric emptying group and the non-delayed gastric emptying group. Since gastric emptying was delayed in healthy women compared with that in healthy men (Tmax, 53.6 ± 19.3 vs. 42.7 ± 16.9 min, p = 0.04), we set the cut-off points of Tmax at 60 min in men and at 75 min in women. In patients with FD, the prevalence of delayed gastric emptying was not different between men and women with the modified standard values of 13C-acetate breath test. (31.0 vs. 27.4%, p = 0.68). BMI was lower in the delayed gastric emptying group than in the non-delayed group among the male patients. Reflux symptoms were more severe in delayed gastric emptying group than in the non-delayed group among the female patients. The standard values of 13C-acetate breath test should be modified bearing the gender difference in mind. It provides us more appropriate information to understand the mechanisms of FD. © 2016 S. Karger AG, Basel.

Bioavailability of ibuprofen following oral administration of standard ibuprofen, sodium ibuprofen or ibuprofen acid incorporating poloxamer in healthy volunteers

PubMed Central

2009-01-01

Background The aim of this study was to compare the pharmacokinetic properties of sodium ibuprofen and ibuprofen acid incorporating poloxamer with standard ibuprofen acid tablets. Methods Twenty-two healthy volunteers were enrolled into this randomised, single-dose, 3-way crossover, open-label, single-centre, pharmacokinetic study. After 14 hours' fasting, participants received a single dose of 2 × 200 mg ibuprofen acid tablets (standard ibuprofen), 2 × 256 mg ibuprofen sodium dihydrate tablets (sodium ibuprofen; each equivalent to 200 mg ibuprofen acid) and 2 × 200 mg ibuprofen acid incorporating 60 mg poloxamer 407 (ibuprofen/poloxamer). A washout period of 2-7 days separated consecutive dosing days. On each of the 3 treatment days, blood samples were collected post dose for pharmacokinetic analyses and any adverse events recorded. Plasma concentration of ibuprofen was assessed using a liquid chromatographic-mass spectrometry procedure in negative ion mode. A standard statistical ANOVA model, appropriate for bioequivalence studies, was used and ratios of 90% confidence intervals (CIs) were calculated. Results Tmax for sodium ibuprofen was less than half that of standard ibuprofen (median 35 min vs 90 min, respectively; P = 0.0002) and Cmax was significantly higher (41.47 μg/mL vs 31.88 μg/mL; ratio test/reference = 130.06%, 90% CI 118.86-142.32%). Ibuprofen/poloxamer was bioequivalent to the standard ibuprofen formulation, despite its Tmax being on average 20 minutes shorter than standard ibuprofen (median 75 mins vs 90 mins, respectively; P = 0.1913), as the ratio of test/reference = 110.48% (CI 100.96-120.89%), which fell within the 80-125% limit of the CPMP and FDA guidelines for bioequivalence. The overall extent of absorption was similar for the three formulations, which were all well tolerated. Conclusion In terms of Tmax, ibuprofen formulated as a sodium salt was absorbed twice as quickly as from standard ibuprofen acid. The addition of poloxamer to ibuprofen acid did not significantly affect absorption. PMID:19961574

A Phase I Study of the Safety and Pharmacokinetics of Higher-Dose Icotinib in Patients With Advanced Non-Small Cell Lung Cancer

PubMed Central

Liu, Jian; Wu, Lihua; Wu, Guolan; Hu, Xingjiang; Zhou, Huili; Chen, Junchun; Zhu, Meixiang; Xu, Wei; Tan, Fenlai; Ding, Lieming; Wang, Yinxiang

2016-01-01

Lessons Learned This phase I study evaluated the maximum tolerated dose, dose-limiting toxicities, safety, pharmacokinetics, and efficacy of icotinib with a starting dose of 250 mg in pretreated, advanced non-small cell lung cancer patients. We observed a maximum tolerated dose of 500 mg with a favorable pharmacokinetics profile and antitumor activity. These findings provide clinicians with evidence for application of higher-dose icotinib. Background. Icotinib, an oral epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has shown favorable tolerability and antitumor activity at 100–200 mg in previous studies without reaching the maximum tolerated dose (MTD). In July 2011, icotinib was approved by the China Food and Drug Administration at a dose of 125 mg three times daily for the treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after failure of at least one platinum-based chemotherapy regimen. This study investigated the MTD, tolerability, and pharmacokinetics of higher-dose icotinib in patients with advanced NSCLC. Methods. Twenty-six patients with advanced NSCLC were treated at doses of 250–625 mg three times daily The EGFR mutation test was not mandatory in this study. Results. Twenty-four (92.3%) of 26 patients experienced at least one adverse event (AE); rash (61.5%), diarrhea (23.1%), and oral ulceration (11.5%) were most frequent AEs. Dose-limiting toxicities were seen in 2 of 6 patients in the 625-mg group, and the MTD was established at 500 mg. Icotinib was rapidly absorbed and eliminated. The amount of time that the drug was present at the maximum concentration in serum (Tmax) ranged from 1 to 3 hours (1.5–4 hours) after multiple doses. The t1/2 was similar after single- and multiple-dose administration (7.11 and 6.39 hours, respectively). A nonlinear relationship was observed between dose and drug exposure. Responses were seen in 6 (23.1%) patients, and 8 (30.8%) patients had stable disease. Conclusion. This study demonstrated that higher-dose icotinib was well-tolerated, with a MTD of 500 mg. Favorable antitumor activity and pharmacokinetic profile were observed in patients with heavily pretreated, advanced NSCLC. PMID:27789778

Variability of Diurnal Temperature Range During Winter Over Western Himalaya: Range- and Altitude-Wise Study

NASA Astrophysics Data System (ADS)

Shekhar, M. S.; Devi, Usha; Dash, S. K.; Singh, G. P.; Singh, Amreek

2018-04-01

The current trends in diurnal temperature range, maximum temperature, minimum temperature, mean temperature, and sun shine hours over different ranges and altitudes of Western Himalaya during winter have been studied. Analysis of 25 years of data shows an increasing trend in diurnal temperature range over all the ranges and altitudes of Western Himalaya during winter, thereby confirming regional warming of the region due to present climate change and global warming. Statistical studies show significant increasing trend in maximum temperature over all the ranges and altitudes of Western Himalaya. Minimum temperature shows significant decreasing trend over Pir Panjal and Shamshawari range and significant increasing trend over higher altitude of Western Himalaya. Similarly, sunshine hours show significant decreasing trend over Karakoram range. There exists strong positive correlation between diurnal temperature range and maximum temperature for all the ranges and altitudes of Western Himalaya. Strong negative correlation exists between diurnal temperature range and minimum temperature over Shamshawari and Great Himalaya range and lower altitude of Western Himalaya. Sunshine hours show strong positive correlation with diurnal temperature range over Pir Panjal and Great Himalaya range and lower and higher altitudes.

40 CFR Table 7 to Subpart U of... - Operating Parameters for Which Monitoring Levels Are Required To Be Established for Continuous...

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum flow or...

40 CFR Table 7 to Subpart Ppp of... - Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

Code of Federal Regulations, 2010 CFR

2010-07-01

... absorbent is used. Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum mass or volumetric flow; and...

40 CFR Table 7 to Subpart U of... - Operating Parameters for Which Monitoring Levels Are Required To Be Established for Continuous...

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum flow or...

40 CFR Table 7 to Subpart Ppp of... - Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

Code of Federal Regulations, 2012 CFR

2012-07-01

... absorbent is used. Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum mass or volumetric flow; and...

40 CFR Table 7 to Subpart Ppp of... - Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

Code of Federal Regulations, 2011 CFR

2011-07-01

... absorbent is used. Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration stream mass or volumetric flow during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum mass or volumetric flow; and...

40 CFR Table 7 to Subpart U of... - Operating Parameters for Which Monitoring Levels Are Required To Be Established for Continuous...

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum flow or...

40 CFR Table 7 to Subpart U of... - Operating Parameters for Which Monitoring Levels Are Required To Be Established for Continuous...

Code of Federal Regulations, 2011 CFR

2011-07-01

.... Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum flow or...

40 CFR Table 7 to Subpart U of... - Operating Parameters for Which Monitoring Levels Are Required To Be Established for Continuous...

Code of Federal Regulations, 2013 CFR

2013-07-01

.... Condenser Exit temperature Maximum temperature. Carbon adsorber Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) a during carbon bed regeneration cycle; and temperature of the carbon bed after regeneration (and within 15 minutes of completing any cooling cycle(s)) Maximum flow or...

40 CFR 86.133-96 - Diurnal emission test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... according to the profile specified in § 86.133 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

40 CFR 86.1233-96 - Diurnal emission test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... according to the profile specified in § 86.1233 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

40 CFR 86.133-96 - Diurnal emission test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... according to the profile specified in § 86.133 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

40 CFR 86.1233-96 - Diurnal emission test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... according to the profile specified in § 86.1233 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

40 CFR 86.133-96 - Diurnal emission test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... according to the profile specified in § 86.133 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

40 CFR 86.1233-96 - Diurnal emission test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... according to the profile specified in § 86.1233 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

40 CFR 86.133-96 - Diurnal emission test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... according to the profile specified in § 86.133 and appendix II of this part. (1) Temperatures measured with the underbody temperature sensor shall follow the profile with a maximum deviation of 3 °F at any time... temperature sensors shall follow the profile with a maximum deviation of 5 °F at any time. (2) Ambient...

Analysis and modeling of extreme temperatures in several cities in northwestern Mexico under climate change conditions

NASA Astrophysics Data System (ADS)

García-Cueto, O. Rafael; Cavazos, M. Tereza; de Grau, Pamela; Santillán-Soto, Néstor

2014-04-01

The generalized extreme value distribution is applied in this article to model the statistical behavior of the maximum and minimum temperature distribution tails in four cities of Baja California in northwestern Mexico, using data from 1950-2010. The approach used of the maximum of annual time blocks. Temporal trends were included as covariates in the location parameter (μ), which resulted in significant improvements to the proposed models, particularly for the extreme maximum temperature values in the cities of Mexicali, Tijuana, and Tecate, and the extreme minimum temperature values in Mexicali and Ensenada. These models were used to estimate future probabilities over the next 100 years (2015-2110) for different time periods, and they were compared with changes in the extreme (P90th and P10th) percentiles of maximum and minimum temperature scenarios for a set of six general circulation models under low (RCP4.5) and high (RCP8.5) radiative forcings. By the end of the twenty-first century, the scenarios of the changes in extreme maximum summer temperature are of the same order in both the statistical model and the high radiative scenario (increases of 4-5 °C). The low radiative scenario is more conservative (increases of 2-3 °C). The winter scenario shows that minimum temperatures could be less severe; the temperature increases suggested by the probabilistic model are greater than those projected for the end of the century by the set of global models under RCP4.5 and RCP8.5 scenarios. The likely impacts on the region are discussed.

Temperature-dependent mechanical properties of single-layer molybdenum disulphide: Molecular dynamics nanoindentation simulations

NASA Astrophysics Data System (ADS)

Zhao, Junhua; Jiang, Jin-Wu; Rabczuk, Timon

2013-12-01

The temperature-dependent mechanical properties of single-layer molybdenum disulphide (MoS2) are obtained using molecular dynamics (MD) nanoindentation simulations. The Young's moduli, maximum load stress, and maximum loading strain decrease with increasing temperature from 4.2 K to 500 K. The obtained Young's moduli are in good agreement with those using our MD uniaxial tension simulations and the available experimental results. The tendency of maximum loading strain with different temperature is opposite with that of metal materials due to the short range Stillinger-Weber potentials in MoS2. Furthermore, the indenter tip radius and fitting strain effect on the mechanical properties are also discussed.

Daily mean temperature estimate at the US SUFRAD stations as an average of the maximum and minimum temperatures

DOE PAGES

Chylek, Petr; Augustine, John A.; Klett, James D.; ...

2017-09-30

At thousands of stations worldwide, the mean daily surface air temperature is estimated as a mean of the daily maximum (T max) and minimum (T min) temperatures. In this paper, we use the NOAA Surface Radiation Budget Network (SURFRAD) of seven US stations with surface air temperature recorded each minute to assess the accuracy of the mean daily temperature estimate as an average of the daily maximum and minimum temperatures and to investigate how the accuracy of the estimate increases with an increasing number of daily temperature observations. We find the average difference between the estimate based on an averagemore » of the maximum and minimum temperatures and the average of 1440 1-min daily observations to be - 0.05 ± 1.56 °C, based on analyses of a sample of 238 days of temperature observations. Considering determination of the daily mean temperature based on 3, 4, 6, 12, or 24 daily temperature observations, we find that 2, 4, or 6 daily observations do not reduce significantly the uncertainty of the daily mean temperature. The bias reduction in a statistically significant manner (95% confidence level) occurs only with 12 or 24 daily observations. The daily mean temperature determination based on 24 hourly observations reduces the sample daily temperature uncertainty to - 0.01 ± 0.20 °C. Finally, estimating the parameters of population of all SURFRAD observations, the 95% confidence intervals based on 24 hourly measurements is from - 0.025 to 0.004 °C, compared to a confidence interval from - 0.15 to 0.05 °C based on the mean of T max and T min.« less

Relationships between water temperatures and upstream migration, cold water refuge use, and spawning of adult bull trout from the Lostine River, Oregon, USA

USGS Publications Warehouse

Howell, P.J.; Dunham, J.B.; Sankovich, P.M.

2010-01-01

Understanding thermal habitat use by migratory fish has been limited by difficulties in matching fish locations with water temperatures. To describe spatial and temporal patterns of thermal habitat use by migratory adult bull trout, Salvelinus confluentus, that spawn in the Lostine River, Oregon, we employed a combination of archival temperature tags, radio tags, and thermographs. We also compared temperatures of the tagged fish to ambient water temperatures to determine if the fish were using thermal refuges. The timing and temperatures at which fish moved upstream from overwintering areas to spawning locations varied considerably among individuals. The annual maximum 7-day average daily maximum (7DADM) temperatures of tagged fish were 16-18 ??C and potentially as high as 21 ??C. Maximum 7DADM ambient water temperatures within the range of tagged fish during summer were 18-25 ??C. However, there was no evidence of the tagged fish using localized cold water refuges. Tagged fish appeared to spawn at 7DADM temperatures of 7-14 ??C. Maximum 7DADM temperatures of tagged fish and ambient temperatures at the onset of the spawning period in late August were 11-18 ??C. Water temperatures in most of the upper Lostine River used for spawning and rearing appear to be largely natural since there has been little development, whereas downstream reaches used by migratory bull trout are heavily diverted for irrigation. Although the population effects of these temperatures are unknown, summer temperatures and the higher temperatures observed for spawning fish appear to be at or above the upper range of suitability reported for the species. Published 2009. This article is a US Governmentwork and is in the public domain in the USA.

Daily mean temperature estimate at the US SUFRAD stations as an average of the maximum and minimum temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chylek, Petr; Augustine, John A.; Klett, James D.

At thousands of stations worldwide, the mean daily surface air temperature is estimated as a mean of the daily maximum (T max) and minimum (T min) temperatures. In this paper, we use the NOAA Surface Radiation Budget Network (SURFRAD) of seven US stations with surface air temperature recorded each minute to assess the accuracy of the mean daily temperature estimate as an average of the daily maximum and minimum temperatures and to investigate how the accuracy of the estimate increases with an increasing number of daily temperature observations. We find the average difference between the estimate based on an averagemore » of the maximum and minimum temperatures and the average of 1440 1-min daily observations to be - 0.05 ± 1.56 °C, based on analyses of a sample of 238 days of temperature observations. Considering determination of the daily mean temperature based on 3, 4, 6, 12, or 24 daily temperature observations, we find that 2, 4, or 6 daily observations do not reduce significantly the uncertainty of the daily mean temperature. The bias reduction in a statistically significant manner (95% confidence level) occurs only with 12 or 24 daily observations. The daily mean temperature determination based on 24 hourly observations reduces the sample daily temperature uncertainty to - 0.01 ± 0.20 °C. Finally, estimating the parameters of population of all SURFRAD observations, the 95% confidence intervals based on 24 hourly measurements is from - 0.025 to 0.004 °C, compared to a confidence interval from - 0.15 to 0.05 °C based on the mean of T max and T min.« less

Physiological and performance changes from the addition of a sprint interval program to wrestling training.

PubMed

Farzad, Babak; Gharakhanlou, Reza; Agha-Alinejad, Hamid; Curby, David G; Bayati, Mahdi; Bahraminejad, Morteza; Mäestu, Jarek

2011-09-01

Increasing the level of physical fitness for competition is the primary goal of any conditioning program for wrestlers. Wrestlers often need to peak for competitions several times over an annual training cycle. Additionally, the scheduling of these competitions does not always match an ideal periodization plan and may require a modified training program to achieve a high level of competitive fitness in a short-time frame. The purpose of this study was to examine the effects of 4 weeks of sprint-interval training (SIT) program, on selected aerobic and anaerobic performance indices, and hormonal and hematological adaptations, when added to the traditional Iranian training of wrestlers in their preseason phase. Fifteen trained wrestlers were assigned to either an experimental (EXP) or a control (CON) group. Both groups followed a traditional preparation phase consisting of learning and drilling technique, live wrestling and weight training for 4 weeks. In addition, the EXP group performed a running-based SIT protocol. The SIT consisted of 6 35-m sprints at maximum effort with a 10-second recovery between each sprint. The SIT protocol was performed in 2 sessions per week, for the 4 weeks of the study. Before and after the 4-week training program, pre and posttesting was performed on each subject on the following: a graded exercise test (GXT) to determine VO(2)max, the velocity associated with V(2)max (νVO(2)max), maximal ventilation, and peak oxygen pulse; a time to exhaustion test (T(max)) at their νVO(2)max; and 4 successive Wingate tests with a 4-minute recovery between each trial for the determination of peak and mean power output (PPO, MPO). Resting blood samples were also collected at the beginning of each pre and posttesting period, before and after the 4-week training program. The EXP group showed significant improvements in VO(2)max (+5.4%), peak oxygen pulse (+7.7%) and T(max) (+32.2%) compared with pretesting. The EXP group produced significant increases in PPO and MPO during the Wingate testing compared with pretesting (p < 0.05). After the 4-week training program, total testosterone and the total testosterone/cortisol ratio increased significantly in the EXP group, whereas cortisol tended to decrease (p = 0.06). The current findings indicate that the addition of an SIT program with short recovery can improve both aerobic and anaerobic performances in trained wrestlers during the preseason phase. The hormonal changes seen suggest training-induced anabolic adaptations.

Pharmacokinetics of hydrocodone extended-release tablets formulated with different levels of coating to achieve abuse deterrence compared with a hydrocodone immediate-release/acetaminophen tablet in healthy subjects.

PubMed

Darwish, Mona; Bond, Mary; Tracewell, William; Robertson, Philmore; Yang, Ronghua

2015-01-01

A hydrocodone extended-release (ER) formulation employing the CIMA(®) Abuse-Deterrence Technology platform was developed to provide resistance against rapid release of hydrocodone when tablets are comminuted or taken with alcohol. This study evaluated the pharmacokinetics of three hydrocodone ER tablet prototypes with varying levels of polymer coating to identify the prototype expected to have the greatest abuse deterrence potential based on pharmacokinetic characteristics that maintain systemic exposure to hydrocodone comparable to that of a commercially available hydrocodone immediate-release (IR) product. In this four-period crossover study, healthy subjects aged 18-45 years were randomized to receive a single intact, oral 45-mg tablet of one of three hydrocodone ER prototypes (low-, intermediate-, or high-level coating) or an intact, oral tablet of hydrocodone IR/acetaminophen (APAP) 10/325 mg every 6 h until four tablets were administered, with each of the four treatments administered once over the four study periods. Dosing periods were separated by a minimum 5-day washout. Naltrexone 50 mg was administered to block opioid receptors. Blood samples for pharmacokinetic assessments were collected predose and through 72 h postdose. Parameters assessed included maximum observed plasma hydrocodone concentration (C(max)), time to C(max) (t(max)), and area under the concentration-time curve from time 0 to infinity (AUC(0-∞)). Mean C(max) values were 49.2, 32.6, and 28.4 ng/mL for the low-, intermediate-, and high-level coating hydrocodone ER tablet prototypes, respectively, and 37.3 ng/mL for the hydrocodone IR/APAP tablet; respective median t(max) values were 5.9, 8.0, 8.0, and 1.0 h. Total systemic exposure to hydrocodone (AUC(0-∞)) was comparable between hydrocodone ER tablet prototypes (640, 600, and 578 ng·h/mL, respectively) and hydrocodone IR/APAP (581 ng·h/mL). No serious adverse events or deaths were reported. The most common adverse events included headache (26%) and nausea (18%). All three hydrocodone ER tablet prototypes (low-, intermediate-, and high-level polymer coating) demonstrated ER pharmacokinetic characteristics. The hydrocodone ER tablet prototype with the high-level coating was selected for development because of its comparable exposure to the hydrocodone IR/APAP formulation and potentially increased ability to resist rapid drug release upon product tampering because of a higher polymer coating level. All study medications were well tolerated in healthy naltrexone-blocked volunteers.

Mid-depth temperature maximum in an estuarine lake

NASA Astrophysics Data System (ADS)

Stepanenko, V. M.; Repina, I. A.; Artamonov, A. Yu; Gorin, S. L.; Lykossov, V. N.; Kulyamin, D. V.

2018-03-01

The mid-depth temperature maximum (TeM) was measured in an estuarine Bol’shoi Vilyui Lake (Kamchatka peninsula, Russia) in summer 2015. We applied 1D k-ɛ model LAKE to the case, and found it successfully simulating the phenomenon. We argue that the main prerequisite for mid-depth TeM development is a salinity increase below the freshwater mixed layer, sharp enough in order to increase the temperature with depth not to cause convective mixing and double diffusion there. Given that this condition is satisfied, the TeM magnitude is controlled by physical factors which we identified as: radiation absorption below the mixed layer, mixed-layer temperature dynamics, vertical heat conduction and water-sediments heat exchange. In addition to these, we formulate the mechanism of temperature maximum ‘pumping’, resulting from the phase shift between diurnal cycles of mixed-layer depth and temperature maximum magnitude. Based on the LAKE model results we quantify the contribution of the above listed mechanisms and find their individual significance highly sensitive to water turbidity. Relying on physical mechanisms identified we define environmental conditions favouring the summertime TeM development in salinity-stratified lakes as: small-mixed layer depth (roughly, ~< 2 m), transparent water, daytime maximum of wind and cloudless weather. We exemplify the effect of mixed-layer depth on TeM by a set of selected lakes.

Canadian crop calendars in support of the early warning project

NASA Technical Reports Server (NTRS)

Trenchard, M. H.; Hodges, T. (Principal Investigator)

1980-01-01

The Canadian crop calendars for LACIE are presented. Long term monthly averages of daily maximum and daily minimum temperatures for subregions of provinces were used to simulate normal daily maximum and minimum temperatures. The Robertson (1968) spring wheat and Williams (1974) spring barley phenology models were run using the simulated daily temperatures and daylengths for appropriate latitudes. Simulated daily temperatures and phenology model outputs for spring wheat and spring barley are given.

Effect of temperature and dissolved oxygen on biological nitrification at high ammonia concentrations.

PubMed

Weon, S Y; Lee, S I; Koopman, B

2004-11-01

Effect of temperature and dissolved oxygen concentration on nitrification rate were investigated with enrichment cultures of nitrifying bacteria. Values of specific nitrite oxidation rate in the absence of ammonia were 2.9-12 times higher than maximum specific ammonia oxidation rates at the same temperatures. The presence of high ammonia levels reversed this relationship, causing maximum specific nitrite oxidation rates to fall to 19 to 45% as high as maximum specific ammonia oxidation rates. This result suggests that nitrification at high ammonia levels will invariably result in nitrite accumulation. The K(O2) for nitrite oxidation in the presence of high ammonia levels was higher than the K(O2) for ammonia oxidation when temperature exceeded 18 degrees C, whereas the opposite was true at lower temperatures. These results indicate that low oxygen tensions will exacerbate nitrite accumulation when water temperature is high.

Extreme Maximum Land Surface Temperatures.

NASA Astrophysics Data System (ADS)

Garratt, J. R.

1992-09-01

There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

Resilience of rice (Oryza spp.) pollen germination and tube growth to temperature stress.

PubMed

Coast, Onoriode; Murdoch, Alistair J; Ellis, Richard H; Hay, Fiona R; Jagadish, Krishna S V

2016-01-01

Resilience of rice cropping systems to potential global climate change will partly depend on the temperature tolerance of pollen germination (PG) and tube growth (PTG). Pollen germination of high temperature-susceptible Oryza glaberrima Steud. (cv. CG14) and Oryza sativa L. ssp. indica (cv. IR64) and high temperature-tolerant O. sativa ssp. aus (cv. N22), was assessed on a 5.6-45.4 °C temperature gradient system. Mean maximum PG was 85% at 27 °C with 1488 μm PTG at 25 °C. The hypothesis that in each pollen grain, the minimum temperature requirements (Tn ) and maximum temperature limits (Tx ) for germination operate independently was accepted by comparing multiplicative and subtractive probability models. The maximum temperature limit for PG in 50% of grains (Tx(50) ) was the lowest (29.8 °C) in IR64 compared with CG14 (34.3 °C) and N22 (35.6 °C). Standard deviation (sx ) of Tx was also low in IR64 (2.3 °C) suggesting that the mechanism of IR64's susceptibility to high temperatures may relate to PG. Optimum germination temperatures and thermal times for 1 mm PTG were not linked to tolerating high temperatures at anthesis. However, the parameters Tx(50) and sx in the germination model define new pragmatic criteria for successful and resilient PG, preferable to the more traditional cardinal (maximum and minimum) temperatures. © 2014 John Wiley & Sons Ltd.

Recurrence quantification analysis of extremes of maximum and minimum temperature patterns for different climate scenarios in the Mesochora catchment in Central-Western Greece

NASA Astrophysics Data System (ADS)

Panagoulia, Dionysia; Vlahogianni, Eleni I.

2018-06-01

A methodological framework based on nonlinear recurrence analysis is proposed to examine the historical data evolution of extremes of maximum and minimum daily mean areal temperature patterns over time under different climate scenarios. The methodology is based on both historical data and atmospheric General Circulation Model (GCM) produced climate scenarios for the periods 1961-2000 and 2061-2100 which correspond to 1 × CO2 and 2 × CO2 scenarios. Historical data were derived from the actual daily observations coupled with atmospheric circulation patterns (CPs). The dynamics of the temperature was reconstructed in the phase-space from the time series of temperatures. The statistically comparing different temperature patterns were based on some discriminating statistics obtained by the Recurrence Quantification Analysis (RQA). Moreover, the bootstrap method of Schinkel et al. (2009) was adopted to calculate the confidence bounds of RQA parameters based on a structural preserving resampling. The overall methodology was implemented to the mountainous Mesochora catchment in Central-Western Greece. The results reveal substantial similarities between the historical maximum and minimum daily mean areal temperature statistical patterns and their confidence bounds, as well as the maximum and minimum temperature patterns in evolution under the 2 × CO2 scenario. A significant variability and non-stationary behaviour characterizes all climate series analyzed. Fundamental differences are produced from the historical and maximum 1 × CO2 scenarios, the maximum 1 × CO2 and minimum 1 × CO2 scenarios, as well as the confidence bounds for the two CO2 scenarios. The 2 × CO2 scenario reflects the strongest shifts in intensity, duration and frequency in temperature patterns. Such transitions can help the scientists and policy makers to understand the effects of extreme temperature changes on water resources, economic development, and health of ecosystems and hence to proceed to effective proactive management of extreme phenomena. The impacts of the findings on the predictability of the extreme daily mean areal temperature patterns are also commented.

Effect of daily environmental temperature on farrowing rate and total born in dam line sows.

PubMed

Bloemhof, S; Mathur, P K; Knol, E F; van der Waaij, E H

2013-06-01

Heat stress is known to adversely affect reproductive performance of sows. However, it is important to know on which days or periods during the reproduction cycle heat stress has the greatest effects for designing appropriate genetic or management strategies. Therefore, this study was conducted to identify days and periods that have greatest effects on farrowing rate and total born of sows using 5 different measures of heat stress. The data consisted of 22,750 records on 5024 Dutch Yorkshire dam line sows from 16 farms in Spain and Portugal. Heat stress on a given day was measured in terms of maximum temperature, diurnal temperature range and heat load. The heat load was estimated using 3 definitions considering different upper critical temperatures. Identification of days during the reproduction cycle that had maximum effect was based on the Pearson correlation between the heat stress variable and the reproduction trait, estimated for each day during the reproduction cycle. Polynomial functions were fitted to describe the trends of these correlations and the days with greatest negative correlation were considered as days with maximum effect. Correlations were greatest for maximum temperature, followed by those for heat load and diurnal temperature range. Correlations for both farrowing rate and total born were stronger in gilts than in sows. This implies that heat stress has a stronger effect on reproductive performance of gilts than of sows. Heat stress during the third week (21 to 14 d) before first insemination had largest effect on farrowing rate. Heat stress during the period between 7 d before successful insemination until 12 d after that had largest effect on total born. Correlations between temperatures on consecutive days during these periods were extremely high ( > 0.9). Therefore, for farrowing rate the maximum temperature on 21 d before first insemination and for total born the maximum temperature at day of successful insemination can be used as predictive measures of heat stress in commercial sow farms. Additionally, differences between daughter groups of sires were identified in response to high temperatures. This might indicate possibilities for genetic selection on heat tolerance.

Factors affecting the estimate of primary production from space

NASA Technical Reports Server (NTRS)

Balch, W. M.; Byrne, C. F.

1994-01-01

Remote sensing of primary production in the euphotic zone has been based mostly on visible-band and water-leaving radiance measured with the coastal zone color scanner. There are some robust, simple relationships for calculating integral production based on surface measurements, but they also require knowledge for photoadaptive parameters such as maximum photosynthesis which currently cannot be obtained from spave. A 17,000-station data set is used to show that space-based estimates of maximum photosynthesis could improve predictions of psi, the water column light utiliztion index, which is an important term in many primary productivity models. Temperature is also examined as a factor for predicting hydrographic structure and primary production. A simple model is used to relate temperature and maximum photosynthesis; the model incorporates (1) the positive relationship between maximum photosynthesis and temperature and (2) the strongly negative relationship between temperature and nitrate in the ocean (which directly affects maximum growth rates via nitrogen limitation). Since these two factors relate to carbon and nitrogen, 'balanced carbon/nitrogen assimilation' was calculated using the Redfield ratio, It is expected that the relationship between maximum balanced carbon assimilation versus temperature is concave-down, with the peak dependent on nitrate uptake kinetics, temperature-nitrate relationships,a nd the carbon chlorophyll ration. These predictions were compared with the sea truth data. The minimum turnover time for nitrate was also calculated using this approach. Lastly, sea surface temperature gradients were used to predict the slope of isotherms (a proxy for the slope of isopycnals in many waters). Sea truth data show that at size scales of several hundred kilometers, surface temperature gradients can provide information on the slope of isotherms in the top 200 m of the water column. This is directly relevant to the supply of nutrients into the surface mixed layer, which is useful for predicting integral biomass and primary production.

Modeling and predicting the biofilm formation of Salmonella Virchow with respect to temperature and pH.

PubMed

Ariafar, M Nima; Buzrul, Sencer; Akçelik, Nefise

2016-03-01

Biofilm formation of Salmonella Virchow was monitored with respect to time at three different temperature (20, 25 and 27.5 °C) and pH (5.2, 5.9 and 6.6) values. As the temperature increased at a constant pH level, biofilm formation decreased while as the pH level increased at a constant temperature, biofilm formation increased. Modified Gompertz equation with high adjusted determination coefficient (Radj(2)) and low mean square error (MSE) values produced reasonable fits for the biofilm formation under all conditions. Parameters of the modified Gompertz equation could be described in terms of temperature and pH by use of a second order polynomial function. In general, as temperature increased maximum biofilm quantity, maximum biofilm formation rate and time of acceleration of biofilm formation decreased; whereas, as pH increased; maximum biofilm quantity, maximum biofilm formation rate and time of acceleration of biofilm formation increased. Two temperature (23 and 26 °C) and pH (5.3 and 6.3) values were used up to 24 h to predict the biofilm formation of S. Virchow. Although the predictions did not perfectly match with the data, reasonable estimates were obtained. In principle, modeling and predicting the biofilm formation of different microorganisms on different surfaces under various conditions could be possible.

Hydrocarbon potential, palynology and palynofacies of four sedimentary basins in the Benue Trough, northern Cameroon

NASA Astrophysics Data System (ADS)

Bessong, Moïse; Hell, Joseph Victor; Samankassou, Elias; Feist-Burkhardt, Susanne; Eyong, John Takem; Ngos, Simon, III; Nolla, Junior Désiré; Mbesse, Cecile Olive; Adatte, Thierry; Mfoumbeng, Marie Paule; Dissombo, Edimo André Noel; Ntsama, Atangana Jacqueline; Mouloud, Bennami; Ndjeng, Emmanuel

2018-03-01

Organic geochemical, palynological and palynofacies analyses were carried out on 79 selected samples from four sedimentary basins (Mayo-Rey, Mayo-Oulo-Lere, Hamakoussou and Benue) in northern Cameroon. Rock-Eval pyrolysis and Total Organic Carbon results indicate that most of the samples of the studied basins are thermally immature to mature. The organic matter consists of terrestrial components (peat, lignite, bituminous coal, and anthracite) associated with organic matter of marine origin. Based on the appraisal of multiple parameters: Total Organic Carbon (TOC), maximum Temperature (T-max), Hydrogen Index (HI), Oxygen Index (OI) and Production Index (PI), some samples are organically rich both in oil and/or gas-prone kerogen Type-II, II/III and III. The source rock quality ranges from poor to very good. The source material is composed of both algae and higher plants. Samples from these basins yielded palynological residue composed of translucent and opaque phytoclasts, Amorphous Organic Matter (AOM), fungal remains, algal cysts pollen and pteridophyte spores. Abundance and diversity of the palynomorphs overall low and include Monoporopollenites annulatus (= Monoporites annulatus), indeterminate periporate pollen, indeterminate tetracolporate pollen, indeterminate tricolporate pollen, indeterminate triporate pollen, indeterminate trilete spores, Polypodiaceoisporites spp., Biporipsilonites sp., Rhizophagites sp., Striadiporites sp., Botryococcus sp. (colonial, freshwater green algae), and Chomotriletes minor (cyst of zygnematalean freshwater green algae). Age assigned confidently for all these basins the palynological data except for one sample of Hamakoussou that can be dated as Early to Mid-Cretaceous in age. Callialasporites dampieri, Classopollis spp., Eucommiidites spp. and Araucariacites australis indicate, an Aptian to Cenomanian age. The other pollen and spores recovered may indicate a Tertiary or younger age (especially Monoporopollenites annulatus), or have arisen from modern contamination. Geochemical data show that sediments are wackes, arkose, iron-sandstone and iron-shale. The Chemical Index of Alteration (CIA-K) is low moderate to high, suggesting a shorter exposure time and fast erosion and transport. The studied sequences cover various depositional settings ranging from wetlands to dry environment inside island arc, passive margin or active continental margin. This study reveals new data and the economic potential of this part of Cameroon.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, C. S.; Zhang, Hongbin

Uncertainty quantification and sensitivity analysis are important for nuclear reactor safety design and analysis. A 2x2 fuel assembly core design was developed and simulated by the Virtual Environment for Reactor Applications, Core Simulator (VERA-CS) coupled neutronics and thermal-hydraulics code under development by the Consortium for Advanced Simulation of Light Water Reactors (CASL). An approach to uncertainty quantification and sensitivity analysis with VERA-CS was developed and a new toolkit was created to perform uncertainty quantification and sensitivity analysis with fourteen uncertain input parameters. Furthermore, the minimum departure from nucleate boiling ratio (MDNBR), maximum fuel center-line temperature, and maximum outer clad surfacemore » temperature were chosen as the selected figures of merit. Pearson, Spearman, and partial correlation coefficients were considered for all of the figures of merit in sensitivity analysis and coolant inlet temperature was consistently the most influential parameter. We used parameters as inputs to the critical heat flux calculation with the W-3 correlation were shown to be the most influential on the MDNBR, maximum fuel center-line temperature, and maximum outer clad surface temperature.« less

Uncertainty quantification and sensitivity analysis with CASL Core Simulator VERA-CS

DOE PAGES

Brown, C. S.; Zhang, Hongbin

2016-05-24

Uncertainty quantification and sensitivity analysis are important for nuclear reactor safety design and analysis. A 2x2 fuel assembly core design was developed and simulated by the Virtual Environment for Reactor Applications, Core Simulator (VERA-CS) coupled neutronics and thermal-hydraulics code under development by the Consortium for Advanced Simulation of Light Water Reactors (CASL). An approach to uncertainty quantification and sensitivity analysis with VERA-CS was developed and a new toolkit was created to perform uncertainty quantification and sensitivity analysis with fourteen uncertain input parameters. Furthermore, the minimum departure from nucleate boiling ratio (MDNBR), maximum fuel center-line temperature, and maximum outer clad surfacemore » temperature were chosen as the selected figures of merit. Pearson, Spearman, and partial correlation coefficients were considered for all of the figures of merit in sensitivity analysis and coolant inlet temperature was consistently the most influential parameter. We used parameters as inputs to the critical heat flux calculation with the W-3 correlation were shown to be the most influential on the MDNBR, maximum fuel center-line temperature, and maximum outer clad surface temperature.« less

Effects of EVA gloves on grip strength and fatigue under low temperature and low pressure.

PubMed

Tian, Yinsheng; Ding, Li; Liu, Heqing; Li, Yan; Li, Deyu; Wang, Li

2016-03-01

To study the effects of wearing extravehicular activity (EVA) gloves on grip strength and fatigue in low temperature, low pressure and mixing of two factors (low temperature and low pressure). The maximum grip strength and fatigue tests were performed with 10 healthy male subjects wearing gloves in a variety of simulated environments. The data was analysed using the normalization method. The results showed that wearing gloves significantly affected the maximum grip strength and fatigue. Pressure (29.6, 39.2 kPa) had more influence on the maximum grip compared with control group while low temperatures (-50, -90, -110 °C) had no influence on grip but affected fatigue dramatically. The results also showed that the maximum grip strength and fatigue were influenced significantly in a compound environment. Space environment remarkably reduced strength and endurance of the astronauts. However, the effects brought by the compound environment cannot be understood as the superimposition of low temperature and pressure effects. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Trends in Middle East climate extreme indices from 1950 to 2003

NASA Astrophysics Data System (ADS)

Zhang, Xuebin; Aguilar, Enric; Sensoy, Serhat; Melkonyan, Hamlet; Tagiyeva, Umayra; Ahmed, Nader; Kutaladze, Nato; Rahimzadeh, Fatemeh; Taghipour, Afsaneh; Hantosh, T. H.; Albert, Pinhas; Semawi, Mohammed; Karam Ali, Mohammad; Said Al-Shabibi, Mansoor Halal; Al-Oulan, Zaid; Zatari, Taha; Al Dean Khelet, Imad; Hamoud, Saleh; Sagir, Ramazan; Demircan, Mesut; Eken, Mehmet; Adiguzel, Mustafa; Alexander, Lisa; Peterson, Thomas C.; Wallis, Trevor

2005-11-01

A climate change workshop for the Middle East brought together scientists and data for the region to produce the first area-wide analysis of climate extremes for the region. This paper reports trends in extreme precipitation and temperature indices that were computed during the workshop and additional indices data that became available after the workshop. Trends in these indices were examined for 1950-2003 at 52 stations covering 15 countries, including Armenia, Azerbaijan, Bahrain, Cyprus, Georgia, Iran, Iraq, Israel, Jordan, Kuwait, Oman, Qatar, Saudi Arabia, Syria, and Turkey. Results indicate that there have been statistically significant, spatially coherent trends in temperature indices that are related to temperature increases in the region. Significant, increasing trends have been found in the annual maximum of daily maximum and minimum temperature, the annual minimum of daily maximum and minimum temperature, the number of summer nights, and the number of days where daily temperature has exceeded its 90th percentile. Significant negative trends have been found in the number of days when daily temperature is below its 10th percentile and daily temperature range. Trends in precipitation indices, including the number of days with precipitation, the average precipitation intensity, and maximum daily precipitation events, are weak in general and do not show spatial coherence. The workshop attendees have generously made the indices data available for the international research community.

Temperature induced changes in size dependent distributions of two boreal and three Lusitanian flatfish species: A comparative study

NASA Astrophysics Data System (ADS)

van Hal, Ralf; van Kooten, Tobias; Rijnsdorp, Adriaan D.

2016-01-01

Changes in spatial distribution in several fish species have been related to recent increase in global temperature. In the North Sea, both a poleward shift and a shift to deeper water have been observed. Here, we study the underlying mechanism of these shifts in a comparative study of the changes in distribution of two boreal flatfish species (plaice Pleuronectes platessa and dab Limanda limanda) and three Lusitanian flatfish species (sole Solea solea, solenette Buglossidium luteum, and scaldfish Arnoglossus laterna) as recorded in annual bottom trawl surveys carried out in the North Sea in late summer since 1985. The distribution is analysed in relation to the bottom temperature at the time of the survey as well as to the seasonal maximum bottom temperature earlier in the year. It is shown that the boreal species plaice and dab moved to deeper water and maintained the seasonal maximum temperature that they experienced in earlier periods, while the Lusitanian species sole, solenette, and scaldfish experienced an increase in the seasonal maximum temperature that they experienced while maintaining their depth distribution. This overall response varied between length classes, reflecting a preference for higher temperature of the smaller length classes. The results lend support to the hypothesis that the fish displayed a direct response to the maximum temperature that occurred during the growth season before the time of sampling.

Coolant and ambient temperature control for chillerless liquid cooled data centers

DOEpatents

Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

2016-02-02

Cooling control methods include measuring a temperature of air provided to a plurality of nodes by an air-to-liquid heat exchanger, measuring a temperature of at least one component of the plurality of nodes and finding a maximum component temperature across all such nodes, comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold, and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the plurality of nodes based on the comparisons.

Maximum temperatures of 89°C recorded during the mechanical preparation of 35 femoral heads for resurfacing

PubMed Central

2011-01-01

Background and purpose We noticed that our instruments were often too hot to touch after preparing the femoral head for resurfacing, and questioned whether the heat generated could exceed temperatures known to cause osteonecrosis. Patients and methods Using an infra-red thermal imaging camera, we measured real-time femoral head temperatures during femoral head reaming in 35 patients undergoing resurfacing hip arthroplasty. 7 patients received an ASR, 8 received a Cormet, and 20 received a Birmingham resurfacing arthroplasty. Results The maximum temperature recorded was 89°C. The temperature exceeded 47°C in 28 patients and 70°C in 11. The mean duration of most stages of head preparation was less than 1 min. The mean time exceeded 1 min only on peripheral head reaming of the ASR system. At temperatures lower than 47°C, only 2 femoral heads were exposed long enough to cause osteonecrosis. The highest mean maximum temperatures recorded were 54°C when the proximal femoral head was resected with an oscillating saw and 47°C during peripheral reaming with the crown drill. The modified new Birmingham resurfacing proximal femoral head reamer substantially reduced the maximum temperatures generated. Lavage reduced temperatures to a mean of 18°C. Interpretation 11 patients were subjected to temperatures sufficient to cause osteonecrosis secondary to thermal insult, regardless of the duration of reaming. In 2 cases only, the length of reaming was long enough to induce damage at lower temperatures. Lavage and sharp instruments should reduce the risk of thermal insult during hip resurfacing. PMID:22066558

Characterization of starch from tubers of yam bean (Pachyrhizus ahipa).

PubMed

Forsyth, Jane L; Ring, Steve G; Noel, Timothy R; Parker, Roger; Cairns, Paul; Findlay, Kim; Shewry, Peter R

2002-01-16

Detailed studies of the starch present in tubers of six accessions of Pachyrhizus ahipa (ahipa) have been carried out using starches from tubers of P. erosus (Mexican yam bean) and seeds of ahipa and wheat for comparison. Starch accounted for 56-58% of the tuber dry weight with granules occurring in a range of geometric forms and in sizes from below 5 microm to about 35 microm (mean about 10 microm in all accessions except two). The amylose content ranged from 11.6 to 16.8% compared with 16.9% in P. erosus tubers and over 23% in the seed starches. X- ray diffraction analysis showed A-type or C(A)-type diffraction patterns. The chain-length distribution of the amylopectin after enzyme debranching showed a peak at DP11 similar to that of wheat starch, but had a less marked shoulder at DP 21-22 and contained a higher proportion of longer chains. Differential scanning calorimitry showed an endothermic peak corresponding to gelatinization with T(max) ranging from 59 to 63 degrees C, which was similar to the T(max) of wheat (about 64 degrees C). The composition of the ahipa starch may mean that it is suitable for food applications that require low amylose content and low retrogradation after processing.

Magnetic Active Agent Release System (MAARS): evaluation of a new way for a reproducible, externally controlled drug release into the small intestine.

PubMed

Dietzel, Christian T; Richert, Hendryk; Abert, Sandra; Merkel, Ute; Hippius, Marion; Stallmach, Andreas

2012-08-10

Human absorption studies are used to test new drug candidates for their bioavailability in different regions of the gastrointestinal tract. In order to replace invasive techniques (e.g. oral or rectal intubation) a variety of externally controlled capsule-based drug release systems has been developed. Most of these use ionizing radiation, internal batteries, heating elements or even chemicals for the localization and disintegration process of the capsule. This embodies potential harms for volunteers and patients. We report about a novel technique called "Magnetic Active Agent Release System" (MAARS), which uses purely magnetic effects for this purpose. In our trial thirteen healthy volunteers underwent a complete monitoring and release procedure of 250 mg acetylsalicylic acid (ASA) targeting the flexura duodenojejunalis and the mid-part of the jejunum. During all experiments MAARS initiated a sufficient drug release and was well tolerated. Beside this we also could show that the absorption of ASA is about two times faster in the more proximal region of the flexura duodenojejunalis with a tmax of 47±13 min compared to the more distal jejunum with tmax values of 100±10 min (p=0.031). Copyright © 2012 Elsevier B.V. All rights reserved.

Pharmacokinetic profiles of repaglinide in elderly subjects with type 2 diabetes.

PubMed

Hatorp, V; Huang, W C; Strange, P

1999-04-01

Pharmacokinetic profiles of single- and multiple-dose regimens of repaglinide were evaluated in 12 elderly subjects with type 2 diabetes. On day 1, following a 10-hour fast, subjects received a single 2-mg dose of repaglinide. Starting on day 2 and continuing for 7 days, each subject received a 2-mg dose of repaglinide 15 minutes before each of the three main meals. On day 9, subjects received a single 2-mg dose of repaglinide. Pharmacokinetic profiles, including area under the curve (AUC), log(AUC), maximal concentration (Cmax), log(Cmax), time to maximal concentration (Tmax), and half-life (T(1/2)), were determined at completion of the single- and multiple-dose regimens (days 1 and 9, respectively). Trough repaglinide values were collected on days 2 through 7. The mean log(AUC) values after multiple dosing were significantly higher than the values obtained after a single dose. The mean values for log(Cmax), and Tmax were comparable after each dosing regimen. The T(1/2) of repaglinide after multiple dosing was 1.7 hours. The trough values for repaglinide were low. No hypoglycemic events were reported. The pharmacokinetic profiles of repaglinide after single- and multiple-dose regimens were similar, and repaglinide was well tolerated by elderly subjects with type 2 diabetes.

Using apatite fission track thermochronology to document the deformation sequence in an exhumed foreland basin: an example from the southern Pyrenees.

NASA Astrophysics Data System (ADS)

Meresse, F.; Labaume, P.; Jolivet, M.; Teixell, A.

2009-04-01

Université Montpellier 2, INSU-CNRS, Laboratoire Géosciences Montpellier, cc060, 34095 Montpellier Cedex 5, France florian.meresse@gm.univ-montp2.fr The study of foreland basins provides important constraints on the evolution of orogenic wedges. In particular, the study of tectonics-sedimentation relationships is essential to date the tectonic activity. However, processes linked to wedge growth are not always completely recorded by the tecto-sedimentary markers, and thermochronological study of the basin-fill can provide further insights. In this work, we have combined apatite fission track analysis (apatite FTA) with structural analysis to precise the timing of the deformation sequence and to characterise the coupling between thrust activity, burial and denudation in the south-Pyrenean foreland basin, a proximal foredeep of the Pyrenees that has been incorporated in the Pyrenean thrust wedge. We have focused the study on a NNE-SSW cross-section of the south-vergent thrust system from the southern flank of the Axial Zone to the South-Pyrenean Frontal Thrust (SPFT), in the west-central part of the belt. This section provides a complete transverse of the South-Pyrenean Zone, here corresponding to the Ainsa and Jaca basins. Apatite FTA provides important new constraints on the south-Pyrenean foreland basin evolution: (i) Data show the southward decrease of the fission track reset level, from a total reset (indicating heating at Tmax>110°C) in the Paleozoic of the Axial Zone, to a partial reset (110°C>Tmax>60°C) in the lower-middle Eocene Hecho Group turbidites in the northern part of the Jaca basin, and to the absence of reset (Tmax<60°C) in the middle Eocene-Oligocene continental sediments of the southern part of the Jaca basin. This indicates a decreasing amount of denudation going southwards, from more than 4.5 km in the north to less than 2.5 km in the south if we assume an average geothermal gradient around 25°/km. The structural setting of the Jaca basin attests that the burial of sediments was mainly due to sedimentary accumulation. (ii) Results in the Hecho Group turbidites bring evidence of exhumation around 18 Ma on the Oturia thrust in the middle of the Jaca basin, an age that is younger than the Middle Eocene to Aquitanian deformation registered by tecto-sedimentary relationships in the southernmost part of the basin (Guarga syncline and SPFT). These tectonic movements may be related to the exhumation, at the same time, of the southern flank of the Axial Zone by out-of-sequence thrusting on the Bielsa basement thrust (Jolivet et al., 2007*). Therefore, low-temperature thermochronology reveals an out-of-sequence episode of deformation in the interior of the south-Pyrenean thrust wedge that had remained unknown due to the lack of related sedimentary record. This late tectonic activity is younger than the generally admitted Aquitanian age for the end of the Pyrenean compression, and would be linked to an ultimate internal thickening stage in the orogenic wedge (Meresse et al., this volume). (*Tectonics, 2007, vol. 26, doi: 10.1029/2006TC002080)

Spatial statistical network models for stream and river temperature in New England, USA

NASA Astrophysics Data System (ADS)

Detenbeck, Naomi E.; Morrison, Alisa C.; Abele, Ralph W.; Kopp, Darin A.

2016-08-01

Watershed managers are challenged by the need for predictive temperature models with sufficient accuracy and geographic breadth for practical use. We described thermal regimes of New England rivers and streams based on a reduced set of metrics for the May-September growing season (July or August median temperature, diurnal rate of change, and magnitude and timing of growing season maximum) chosen through principal component analysis of 78 candidate metrics. We then developed and assessed spatial statistical models for each of these metrics, incorporating spatial autocorrelation based on both distance along the flow network and Euclidean distance between points. Calculation of spatial autocorrelation based on travel or retention time in place of network distance yielded tighter-fitting Torgegrams with less scatter but did not improve overall model prediction accuracy. We predicted monthly median July or August stream temperatures as a function of median air temperature, estimated urban heat island effect, shaded solar radiation, main channel slope, watershed storage (percent lake and wetland area), percent coarse-grained surficial deposits, and presence or maximum depth of a lake immediately upstream, with an overall root-mean-square prediction error of 1.4 and 1.5°C, respectively. Growing season maximum water temperature varied as a function of air temperature, local channel slope, shaded August solar radiation, imperviousness, and watershed storage. Predictive models for July or August daily range, maximum daily rate of change, and timing of growing season maximum were statistically significant but explained a much lower proportion of variance than the above models (5-14% of total).

Evaluation of extreme temperature events in northern Spain based on process control charts

NASA Astrophysics Data System (ADS)

Villeta, M.; Valencia, J. L.; Saá, A.; Tarquis, A. M.

2018-02-01

Extreme climate events have recently attracted the attention of a growing number of researchers because these events impose a large cost on agriculture and associated insurance planning. This study focuses on extreme temperature events and proposes a new method for their evaluation based on statistical process control tools, which are unusual in climate studies. A series of minimum and maximum daily temperatures for 12 geographical areas of a Spanish region between 1931 and 2009 were evaluated by applying statistical process control charts to statistically test whether evidence existed for an increase or a decrease of extreme temperature events. Specification limits were determined for each geographical area and used to define four types of extreme anomalies: lower and upper extremes for the minimum and maximum anomalies. A new binomial Markov extended process that considers the autocorrelation between extreme temperature events was generated for each geographical area and extreme anomaly type to establish the attribute control charts for the annual fraction of extreme days and to monitor the occurrence of annual extreme days. This method was used to assess the significance of changes and trends of extreme temperature events in the analysed region. The results demonstrate the effectiveness of an attribute control chart for evaluating extreme temperature events. For example, the evaluation of extreme maximum temperature events using the proposed statistical process control charts was consistent with the evidence of an increase in maximum temperatures during the last decades of the last century.

The Effects of Engine Speed and Mixture Temperature on the Knocking Characteristics of Several Fuels

NASA Technical Reports Server (NTRS)

Lee, Dana W

1940-01-01

Six 100-octane and two 87-octane aviation engine fuels were tested in a modified C.F.R. variable-compression engine at 1,500, 2,000 and 2,500 rpm. The mixture temperature was raised from 50 to 300 F in approximately 50 degree steps and, at each temperature, the compression ratio was adjusted to give incipient knock as shown by a cathode ray indicator. The results are presented in tabular form. The results are analyzed on the assumption that the conditions which determine whether a given fuel will knock are the maximum values of density and temperature reached by the burning gases. A maximum permissible density factor, proportional to the maximum density of the burning gases just prior to incipient knock, and the temperature of the burning gases at that time were computed for each of the test conditions. Values of the density factors were plotted against the corresponding end-gas temperatures for the three engine speeds and also against engine speed for several and end-gas temperatures. The maximum permissible density factor varied only slightly with engine speed but decreased rapidly with an increase in the end-gas temperature. The effect of changing the mixture temperature was different for fuels of different types. The results emphasize the desirability of determining the anti knock values of fuels over a wide range of engine and intake-air conditions rather that at a single set of conditions.

Operational forecasting of daily temperatures in the Valencia Region. Part I: maximum temperatures in summer.

NASA Astrophysics Data System (ADS)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of summer maximum temperatures is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, summer maximum daily temperatures are considered a parameter of interest and concern since persistent heat-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict heat-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that high temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily maximum temperatures during summer over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the summer forecast period of 1 June - 30 September, 2007. The results obtained are encouraging and indicate a good agreement between the observed and simulated maximum temperatures. Moreover, the model captures quite well the temperatures in the extreme heat episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia, Spain).