Using inertial fusion implosions to measure the T + He 3 fusion cross section at nucleosynthesis-relevant energies

DOE PAGES

Zylstra, A. B.; Herrmann, H. W.; Johnson, M. Gatu; ...

2016-07-11

Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of 6Li in low-metallicity stars. Using high energy-density plasmas we measure the T( 3He,γ) 6Li reaction rate, a candidate for anomalously high 6Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. In conclusion, this is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics.

Natural Oxidation of Bromide to Bromine in Evaporated Dead Sea Brines

NASA Astrophysics Data System (ADS)

Gavrieli, Ittai; Golan, Rotem; Lazar, Boaz; Baer, Gidi; Zakon, Yevgeni; Ganor, Jiwchar

2016-04-01

Highly evaporated Dead Sea brines are found in isolated sinkholes along the Dead Sea. Many of these brines reach densities of over 1.3 kg/L and pH<5 and are the product of evaporation of Dead Sea brine that drain into the sinkholes. The low pH and the reddish to brownish hue of these brines were an enigma until recently. Despite the rather high total alkalinity (TA) of the Dead Sea (3.826 mmol/kg) the pH of the Dead Sea brine is known to be slightly acidic with a value of ~6.3. In comparison, seawater with the same alkalinity would have a pH value well above 8.3, meaning that H+ activity is 100 fold lower than that of Dead Sea brine. In the present work we assess the apparent dissociation constant value of boric acid (K`B) for the Dead Sea brine and use it to explain the brine's low pH value. We then show that pH decreases further as the brine evaporates and salinity increases. Finally we explain the reddish hue of the hypersaline brines in the sinkholes as due to the presence of dissolved bromine. The latter is the product of oxidation of dissolved bromide, a process that is enabled by the low pH of the hypersaline brines and their high bromide concentration.

The natural food colorant Peonidin from cranberries as a potential radical scavenger - A DFT based mechanistic analysis.

PubMed

Rajan, Vijisha K; Hasna, C K; Muraleedharan, K

2018-10-01

A theoretical evaluation of the antioxidant property of a natural food colorant Peonidin has been performed. The most suitable mechanism for explaining the radical scavenging capacity of Peonidin is the Hydrogen Atom Transfer and the most active site for radical formation is position 3 and is confirmed through Mulliken charge analysis, pKa value evaluation, Bond Dissociation Energy values, and Natural Bond Orbital analysis. Position 3 and 5 in Peonidin exists in blood as deprotonated as their pKa values are lower than the pH of blood. Peonidin is highly reactive than Quercetin and less stable than flavan-3-ols due to the small band gap. Global descriptor analysis shows that PN prefers to accept electrons than to donate. The effect of number of OH groups and the nature of substituents are well explained through this work. Copyright © 2018 Elsevier Ltd. All rights reserved.

Behavior of hydrogen in alpha-iron at lower temperatures

NASA Technical Reports Server (NTRS)

Weizer, V. G.

1973-01-01

Evidence is presented that the low temperature anomalies in the hydrogen occlusive behavior of alpha iron can be explained by means of a molecular occlusion theory. This theory proposes that the stable state of the absorbed hydrogen changes from atomic at high temperatures to molecular as the temperature is lowered below a critical value. Theories proposing to explain the anomalous behavior as being due to the capture, at lower temperatures, of hydrogen in traps are shown to be unacceptable.

Life test results for the advanced very high resolution radiometer scanner

NASA Technical Reports Server (NTRS)

Lenz, James

1996-01-01

The following paper reports the results obtained during a 3.33-year life test on the TIROS Advanced Very High Resolution Radiometer/3 (AVHRR/3) Scanner. The bearing drag torque and lubricant loss over life will be compared to predicted values developed through modeling. The condition of the lubricant at the end of the test will be described and a theory presented to explain the results obtained. The differences (if any) in the predicted and measured values of drag torque and lubricant loss will be discussed and possible reasons for these examined.

Key Elements of a Good Mathematics Lesson as Seen by Japanese Junior High School Teachers

ERIC Educational Resources Information Center

Ebaeguin, Marlon; Stephens, Max

2016-01-01

This study makes a comparison between what literature on Japanese Lesson Study suggests are key elements of a good mathematics lesson and what junior high school mathematics teachers in Japan value in planning their lessons. The teachers' strong consensus in their endorsements of these key elements explains why Japanese teachers strongly support…

Environmental Isotope Characteristics of Landfill Leachates and Gases

USGS Publications Warehouse

Hackley, Keith C.; Liu, Chao-Li; Coleman, D.D.

1996-01-01

The isotopic characteristics of municipal landfill leachate and gases (carbon dioxide and methane) are unique relative to the aqueous and gaseous media in most other natural geologic environments. The ??13 C of the CO2 in landfills is significantly enriched in 13C, with values as high as +20??? reported. The ?? 13C and ??D values of the methane fall within a range of values representative of microbial methane produced primarily by the acetate-fermentation process. The ??D of landfill leachate is strongly enriched in deuterium, by approximately 30??? to nearly 60??? relative to local average precipitation values. This deuterium enrichment is undoubtedly due to the extensive production of microbial methane within the limited reservoir of a landfill. The concentration of the radiogenic isotopes, 14C and 3H, are significantly elevated in both landfill leachate and methane. The 14C values range between approximately 120 and 170 pMC and can be explained by the input of organic material that was affected by the increased 14C content of atmospheric CO2 caused by atmospheric testing of nuclear devices. The tritium measured in leachate, however, is often too high to be explained by previous atmospheric levels and must come from material buried within the landfill. The unique isotopic characteristics observed in landfill leachates and gases provide a very useful technique for confirming whether contamination is from a municipal landfill or some other local source.

Columnar travertines: bio-influenced genesis, Porcelana Geysers, Northern Patagonia, Chile

NASA Astrophysics Data System (ADS)

Ruiz, B. S.; Morata, D.; Díez, B.; Daniele, L.

2017-12-01

Porcelana Geysers are located on the slopes of Barranco Colorado volcano, southern Chile, and is characterized by having a lateral hydrothermal fluid transport and an important CO2 content, having high gas exsolution rates on the surface at temperatures above 80°C. But it does not seem to be enough to explain the genesis of columnar travertines more than 3 meters high, considering that precipitation rates counteracts erosive rates due to rainy climate of the zone and the high slope gradient (>10 mm/h). The presence of extremophilic microbial diversity could explain this exceptional travertine morphology, particularly Phyla Cyanobacteria, Bacteroidetes and Order Thermales, which is evidenced by the vast visible presence of extracellular polymeric substances (EPS), reducing conditions in hot springs waters, microscopic and macroscopic textures and isotopic compositions of travertines, which are lower than the values that thermogenic travertines usually present (δ13C values from -4.85‰ to -3.37‰). These biotic processes would increase total dissolved gas pressure and [CO2]AQ values (over 0.05 mmol/L), and hence making the hydrostatic and bubbling pressure lower in the geysers vent fluids, which increases the amount of bubbles and their size and precipitation total rate of calcium carbonate (about 0.003 mm/h)

High Reward Makes Items Easier to Remember, but Harder to Bind to a New Temporal Context

PubMed Central

Madan, Christopher R.; Fujiwara, Esther; Gerson, Bridgette C.; Caplan, Jeremy B.

2012-01-01

Learning through reward is central to adaptive behavior. Indeed, items are remembered better if they are experienced while participants expect a reward, and people can deliberately prioritize memory for high- over low-valued items. Do memory advantages for high-valued items only emerge after deliberate prioritization in encoding? Or, do reward-based memory enhancements also apply to unrewarded memory tests and to implicit memory? First, we tested for a high-value memory advantage in unrewarded implicit- and explicit-tests (Experiment 1). Participants first learned high or low-reward values of 36 words, followed by unrewarded lexical decision and free-recall tests. High-value words were judged faster in lexical decision, and more often recalled in free recall. These two memory advantages for high-value words were negatively correlated suggesting at least two mechanisms by which reward value can influence later item-memorability. The ease with which the values were originally acquired explained the negative correlation: people who learned values earlier showed reward effects in implicit memory whereas people who learned values later showed reward effects in explicit memory. We then asked whether a high-value advantage would persist if trained items were linked to a new context (Experiments 2a and 2b). Following the same value training as in Experiment 1, participants learned lists composed of previously trained words mixed with new words, each followed by free recall. Thus, participants had to retrieve words only from the most recent list, irrespective of their values. High- and low-value words were recalled equally, but low-value words were recalled earlier than high-value words and high-value words were more often intruded (proactive interference). Thus, the high-value advantage holds for implicit- and explicit-memory, but comes with a side effect: High-value items are more difficult to relearn in a new context. Similar to emotional arousal, reward value can both enhance and impair memory. PMID:22969711

Helping Young Children to Develop Character.

ERIC Educational Resources Information Center

Crosser, Sandra

1997-01-01

Argues that, of the authoritarian, permissive, and authoritative styles of interaction with children, the latter nurtures the emergence of positive character traits in young children. Suggests listening, setting high and reasonable standards, explaining why, negotiating reasonable solutions, offering choices, and valuing ideas and opinions as…

An improved oxygen diffusion model to explain the effect of low-temperature baking on high field losses in niobium superconducting cavities

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

Ciovati, Gianluigi

Radio-frequency (RF) superconducting cavities made of high purity niobium are widely used to accelerate charged particle beams in particle accelerators. The major limitation to achieve RF field values approaching the theoretical limit for niobium is represented by ''anomalous'' losses which degrade the quality factor of the cavities starting at peak surface magnetic fields of about 100 mT, in absence of field emission. These high field losses are often referred to as ''Q-drop''. It has been observed that the Q-drop is drastically reduced by baking the cavities at 120 C for about 48 h under ultrahigh vacuum. An improved oxygen diffusionmore » model for the niobium-oxide system is proposed to explain the benefit of the low-temperature baking on the Q-drop in niobium superconducting rf cavities. The model shows that baking at 120 C for 48 h allows oxygen to diffuse away from the surface, and therefore increasing the lower critical field towards the value for pure niobium.« less

TLR4 preconditioning is associated with low success of OK-432 treatment for lymphatic malformations in children.

PubMed

Reismann, Marc; Ghaffarpour, Nader; Luvall, Ethel; Jirmo, Adan; Radtke, Josephine; Claesson, Gösta; Wester, Tomas

2016-05-01

We have recently shown that the relative TLR4 expression on monocytes of low responding pediatric patients after OK-432 treatment is significantly reduced after stimulation with lipopolysaccharide (LPS) compared with high responding children. The aim of this study was to perform further analysis to explain this observation. Monocytes from children with high (HR, n = 5) and low response (LR, n = 6) after previous OK-432 treatment were stimulated with LPS for 20 h and analyzed with fluorescence-activated cell sorting (mean fluorescence intensity, MFI; level of significance P ≤ 0.05). Mean MFI after LPS stimulation was comparable in both groups (HR 1142 ± 652 units, LR 839 ± 427 units, P = 0.85). Significant changes after LPS stimulation are explained by higher pre-stimulation values in the LR group compared with the HR group (950 ± 718 vs. 477 ± 341, P = 0.25) with considerable differences of the mean expression changes after LPS stimulation (HR 665 ± 683 vs. LR -111 ± 605, P = 0.08). The previously shown reduced TLR4 upregulation on monocytes after LPS stimulation in the LR group compared with the HR group can be primarily explained by TLR preconditioning. This observation implies the use of absolute values with definite thresholds.

A MODEL FOR THE SOURCES OF THE SLOWLY VARYING COMPONENT OF MICROWAVE SOLAR RADIATION

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

Swarup, G.; Kakinuma, T.

1962-11-01

A comparison of the observations of the slowly varying component of the solar radio emission made with highresolution interferometers operating at wavelengths of 3.2, strong sources are higher at the longer wavelengths than at 3 cm. The same conclusion is derived from eclipse and statistical investigations, which indicate further that the spectrum of the flux density has a peak around 6 cm. The decrease in flux density with frequency cannot be explained simply by assuming a greater optical thickness for the extraordinary wave near 10 cm in the million-degree corona, as given by the magneto-ionic theory, since the observed degreemore » of polarization at 7.5 or 9.1 cm is much lower than that at 3.2 cm. It is suggested that radiation at the gyrofrequency and its harmonics emitted by the thermal electrons in the dense region over a sunspot group should be raken into account to explain the spectrum of the slowly varying component. This mechanism of resonance absorption requires the average strength of the magnetic field over the sunspot group to be about 800 gauss at a height of 2 x 10/sup 4/ km above the photosphere and 250 gauss at a height of 4 x 10/sup 4/ km. In order to explain the observed values of brightness temperature of 1/-4 x 10/sup 6/ deg K near 10 cm by the magneto-ionic theory, it is necessary to assume values of electron density of up to 20 or 40 times the normal. However, these high values of densities are not required by the gyro-theory, and values of five to ten times the normal are sufficient for explaining simultaneously the observations of brightness temperature, flux density, and polarization. This theory also explains the small size of the source in the range 3-10 cm. The radio emission is considered to originate thermally, which requires that the value of the electron temperature in the region of the inner solar corona above a large sunspot group is about 2-4 x 10 deg K. (auth)« less

Asian and European American cultural values and communication styles among Asian American and European American college students.

PubMed

Park, Yong S; Kim, Bryan S K

2008-01-01

The present study examined the relationships between adherence to Asian and European cultural values and communication styles among 210 Asian American and 136 European American college students. A principal components analysis revealed that, for both Asian Americans and European Americans, the contentious, dramatic, precise, and open styles loaded onto the first component suggesting low context communication, and interpersonal sensitivity and inferring meaning styles loaded onto the second component suggesting high context communication. Higher adherence to emotional self-control and lower adherence to European American values explained Asian Americans' higher use of the indirect communication, while higher emotional self-control explained why Asian Americans use a less open communication style than their European American counterparts. When differences between sex and race were controlled, adherence to humility was inversely related to contentious and dramatic communication styles but directly related to inferring meaning style, adherence to European American values was positively associated with precise communication and inferring meaning styles, and collectivism was positively related to interpersonal sensitivity style. 2008 APA

The Transforming Maternity Care Project: Goals, Methods, and Outcomes of a National Maternity Care Policy Initiative, With Construction of a Theoretical Model to Explain the Process

DTIC Science & Technology

2011-03-21

to and receive comprehensive high-quality, high-value reproductive health and maternity care. • Comprehensive health care reform strategies...and its implementation, ensure that access to comprehensive, high-quality reproductive health and maternity care services are essential benefits for... Reproductive Health, Centers for Disease Control and Prevention Stakeholder Workgroup Consumers and their Advocates Chair: Judy Norsigian

The Value of Writing "How-to" Books in High School World History and Geography Class

ERIC Educational Resources Information Center

Jones, Kathryn; Daisey, Peggy

2011-01-01

This article presents a story about eighty-six ninth-grade World History and Geography students who authored a "how-to" book, while pretending that they were experts who lived in the past and had to explain how to do something relating to that time period. These students attended a large high school in the Midwest; the school's…

Diatom responses to precipitation and anthropogenic disturbances in an azorean lake during the last seven centuries

NASA Astrophysics Data System (ADS)

Vázquez-Loureiro, David; Bao, Roberto; Gonçalves, Vitor; Rubio-Inglés, Maria J.; Sáez, Alberto; Hernández, Armand; Raposeiro, Pedro M.; Pueyo, Juan J.; Masqué, Pere; Trigo, Ricardo; Giralt, Santiago

2015-04-01

Sedimentary lacustrine records provide an important source of knowledge of past environmental changes at regional and local scales. Here we perform a diatom-based paleoenvironmental reconstruction, complemented with geochemical proxies, of the recent history of Lake Azul (37° 52' 21' N - 25° 46' 26' W), located in the crater caldera of Sete Cidades volcano, São Miguel Island. A 132 cm long sediment core from the offshore and deepest part of the lake was selected, from a total of fourteen cores extracted in 2011, and dated with21Pb and137Cs, as well as AMS14C. Two main litological intervals were described: at the lower part there are hard volcanic rocks interbedding silty lacustrine episodes, whereas the upper part is made up by silty mud lacustrine sediments. Eight terrestrial-nearshore levels with high values of TOC/TN ratio, low values of δ13C and high abundances of aerophilic diatoms, plus nine volcanic levels, were removed from any further analysis in order to assess changes in in-lake processes. Main environmental gradients driving the composition of the diatom assemblages were explored by a Principal Component Analysis (PCA) on the diatom relative abundance data, and four statistically significant Diatom Assemblage Zones (DAZs) were defined with a cluster analysis (CONISS). The first axis of PCA (PC1), explaining 47.3% of total variance, confronts benthic vs tychoplanktonic and euplanktonic taxa, suggesting a relationship with water depth. The second axis (PC2) explained 23.1% of total variance, showing high positive values for eutrophic taxa of the genus Aulacoseira, and negative values for oligotrophic taxa and diatoms of a broad trophic spectrum. This axis is very likely related to a trophic gradient. DAZ-1 (c. 1280 - 1400 cal yr AD), dominated by benthic taxa, is characterized by positive values of PC1 and PC2, indicating relative shallow lake conditions and a high trophic level, respectively. A transition from a benthic to a facultatively planktonic community (lower PC1 values) occurs in DAZ-2 (c. 1400 - 1800 cal yr AD), suggesting a rise in water level, probably triggered by an increase in precipitation. Negative values of PC2 in this zone and DAZ-3 (c. 1800 - 1960 cal yr AD) might be explained by the dilution of nutrients in a larger water volume. The sharp transition to high positive values of PC2 in DAZ-4 (c. 1960 cal yr AD) coincides with the start in the use of nitrate- and phosphate-rich fertilizers in the surrounding farming area. Long-term changes in diatoms assemblages since the late XIII century in Lake Azul are driven by two factors of natural and anthropogenic origin, respectively; the strong inter-annual variability of the precipitation (largely controlled by the North Atlantic Oscillation, NAO), and the eutrophication of lakes in recent decades.

Exploring experiential value in online mobile gaming adoption.

PubMed

Okazaki, Shintaro

2008-10-01

Despite the growing importance of the online mobile gaming industry, little research has been undertaken to explain why consumers engage in this ubiquitous entertainment. This study attempts to develop an instrument to measure experiential value in online mobile gaming adoption. The proposed scale consists of seven first-order factors of experiential value: intrinsic enjoyment, escapism, efficiency, economic value, visual appeal, perceived novelty, and perceived risklessness. The survey obtained 164 usable responses from Japanese college students. The empirical data fit our first-order model well, indicating a high level of reliability as well as convergent and discriminant validity. The single second-order model also shows an acceptable model fit.

Analysis of the vibration regimes of vascular walls

NASA Astrophysics Data System (ADS)

Kudryashov, A. V.; Rozenblyum, L. A.; Khurlapova, T. V.; Yakhno, V. G.

1980-11-01

The theoretical description exposed here can be used for explaining the differences which are sometimes observed between the values of the diastolic pressure derived from direct measurements and those derived from indirect measurements. Nervous and emotional action may alter markedly the mechanical properties of the muscular layer of the wall. In this respect it is important to what side the hysteresis loop in the radiusstress curve will be shifted. If the hysteresis is shifted towards the region of high pressures, then tones will be recorded at higher pi — P l values and, hence, the error in an indirect measurement of the pressure will increase. From this point of view the phenomenon of an "infinite tone" is explained by the dependence of the hysteresis of the radius on the stress on the wall in the pressure range Pdiast

Potassium dichromate method of coal gasification the study of the typical organic compounds in water

NASA Astrophysics Data System (ADS)

Quan, Jiankang; Qu, Guangfei; Dong, Zhanneng; Lu, Pei; Cai, Yingying; Wang, Shibo

2017-05-01

The national standard method is adopted in this paper the water - digestion spectrophotometry for determination of the chemical oxygen demand (COD), after ultrasonic processing of coal gasification water for CODCr measurement. Using the control variable method, measured in different solution pH, ultrasonic frequency, ultrasonic power, reaction conditions of different initial solution concentration, the change of coal gasification water CODCr value under the action of ultrasonic, the experimental results shows that appear when measurement is allowed to fluctuate, data, in order to explain the phenomenon we adopt the combination of the high performance liquid chromatography and mass spectrometry before and after ultrasonic coal gasification qualitative analysis on composition of organic matter in water. To raw water sample chromatography - mass spectrometry (GC/MS) analysis, combined with the spectra analysis of each peak stands for material, select coal gasification typical organic substances in water, with the method of single digestion, the equivalent CODCr values measured after digestion. Order to produce, coal gasification water contained high concentration organic wastewater, such as the national standard method is adopted to eliminate the organic material, therefore to measure the CODCr value is lower than actual CODCr value of the emergence of the phenomenon, the experiment of the effect of ultrasound [9-13] is promote the complex organic chain rupture, also explains the actual measurement data fluctuation phenomenon in the experiment.

Photograph Analysis.

ERIC Educational Resources Information Center

Eakle, Arlene H.

The booklet explains how family photographs can be used to teach about history, life style, and social values. The approach can be used in elementary or senior high classes in history, social science, or humanities. The personal aspect of using family photographs is seen to be important in ensuring student interest. As historical documents,…

Social Values, Subjective Transformations, and Cooperation in Social Dilemmas

ERIC Educational Resources Information Center

Simpson, Brent

2004-01-01

A persistent anomaly in the social dilemmas literature is the surprisingly high level of cooperation observed in experimental investigations of the one-shot Prisoners' Dilemma (PD). The exchange heuristic hypothesis and related approaches explain this finding by arguing that actors subjectively transform PD into the Assurance Dilemma. A tendency…

Commitment to personal values and guilt feelings in dementia caregivers.

PubMed

Gallego-Alberto, Laura; Losada, Andrés; Márquez-González, María; Romero-Moreno, Rosa; Vara, Carlos

2017-01-01

Caregivers' commitment to personal values is linked to caregivers' well-being, although the effects of personal values on caregivers' guilt have not been explored to date. The goal of this study is to analyze the relationship between caregivers´ commitment to personal values and guilt feelings. Participants were 179 dementia family caregivers. Face-to-face interviews were carried out to describe sociodemographic variables and assess stressors, caregivers' commitment to personal values and guilt feelings. Commitment to values was conceptualized as two factors (commitment to own values and commitment to family values) and 12 specific individual values (e.g. education, family or caregiving role). Hierarchical regressions were performed controlling for sociodemographic variables and stressors, and introducing the two commitment factors (in a first regression) or the commitment to individual/specific values (in a second regression) as predictors of guilt. In terms of the commitment to values factors, the analyzed regression model explained 21% of the variance of guilt feelings. Only the factor commitment to family values contributed significantly to the model, explaining 7% of variance. With regard to the regression analyzing the contribution of specific values to caregivers' guilt, commitment to the caregiving role and with leisure contributed negatively and significantly to the explanation of caregivers' guilt. Commitment to work contributed positively to guilt feelings. The full model explained 30% of guilt feelings variance. The specific values explained 16% of the variance. Our findings suggest that commitment to personal values is a relevant variable to understand guilt feelings in caregivers.

Object Relations and the Development of Values.

ERIC Educational Resources Information Center

Gazda, George M.; Sedgwick, Charlalee

1990-01-01

Claims acquisition of values is related to successes and failures of early relationships. Describes steps person goes through in making identifications, explaining steps that move person toward construction of value system. Refers to works of Heinz Kohut to explain how child's idealizing has within it necessary components for child's growth in…

Occupational value and relationships to meaning and health: elaborations of the ValMO-model.

PubMed

Erlandsson, Lena-Karin; Eklund, Mona; Persson, Dennis

2011-03-01

This study investigates the theoretical assumption of the Value and Meaning in Occupations model. The aim was to explore the relationship between occupational value, perceived meaning, and subjective health in a sample of individuals of working age, 50 men and 250 women. Frequency of experienced values in occupations was assessed through the Occupational Value instrument with pre-defined items. Perceived meaning was operationalized and assessed by the Sense of Coherence measure. Subjective health was estimated by two questions from the SF-36 questionnaire. The analyses implied descriptive analyses, correlations, and logistic regression analyses in which sociodemographic variables were included. The findings showed highly significant relationships between occupational value and perceived meaning and when belonging to the high group of occupational value the likelihood was tripled of belonging to the high group of perceived meaning. When married or cohabitating there was double the likelihood of belonging to the high group of perceived meaning. Although perceived meaning was found to be positively associated with subjective health, working full time was the most important factor in explaining subjective health, compared with working less than full time. The results confirm assumptions in the ValMO-model, and the importance of focusing on occupational value in clinical practice is highlighted.

A high deuterium abundance at redshift z = 0.7.

PubMed

Webb, J K; Carswell, R F; Lanzetta, K M; Ferlet, R; Lemoine, M; Vidal-Madjar, A; Bowen, D V

1997-07-17

Of the light elements, the primordial abundance of deuterium relative to hydrogen, (D/H)p, provides the most sensitive diagnostic for the cosmological mass density parameter, omegaB. Recent high-redshift D/H measurements are highly discrepant, although this may reflect observational uncertainties. The larger primordial D/H values imply a low omegaB (requiring the Universe to be dominated by non-baryonic matter), and cause problems for galactic chemical evolution models, which have difficulty in reproducing the steep decline in D/H to the present-day values. Conversely, the lower D/H values measured at high redshift imply an omegaB greater than that derived from 7Li and 4He abundance measurements, and may require a deuterium-abundance evolution that is too low to easily explain. Here we report the first measurement of D/H at intermediate redshift (z = 0.7010), in a gas cloud selected to minimize observational uncertainties. Our analysis yields a value of D/H ((2.0 +/- 0.5) x 10[-4]) which is at the upper end of the range of values measured at high redshifts. This finding, together with other independent observations, suggests that there may be inhomogeneity in (D/H)p of at least a factor of ten.

Japanese migration in contemporary Japan: economic segmentation and interprefectural migration.

PubMed

Fukurai, H

1991-01-01

This paper examines the economic segmentation model in explaining 1985-86 Japanese interregional migration. The analysis takes advantage of statistical graphic techniques to illustrate the following substantive issues of interregional migration: (1) to examine whether economic segmentation significantly influences Japanese regional migration and (2) to explain socioeconomic characteristics of prefectures for both in- and out-migration. Analytic techniques include a latent structural equation (LISREL) methodology and statistical residual mapping. The residual dispersion patterns, for instance, suggest the extent to which socioeconomic and geopolitical variables explain migration differences by showing unique clusters of unexplained residuals. The analysis further points out that extraneous factors such as high residential land values, significant commuting populations, and regional-specific cultures and traditions need to be incorporated in the economic segmentation model in order to assess the extent of the model's reliability in explaining the pattern of interprefectural migration.

The Impact of Racial Identity, Ethnic Identity, Asian Values and Race-Related Stress on Asian Americans and Asian International College Students’ Psychological Well-Being

PubMed Central

Iwamoto, Derek Kenji; Liu, William Ming

2010-01-01

The current study investigated the direct and moderating effects of racial identity, ethnic identity, Asian values, and race-related stress on positive psychological well-being among 402 Asian American and Asian international college students. Results revealed that the racial identity statuses Internalization, Immersion-Emersion, Dissonance, Asian values and Ethnic Identity Affirmation and Belonging were significant predictors of well-being. Asian values, Dissonance and Conformity were found to moderate the relationship between race-related stress on well-being. Specifically, individuals in low race-related stress conditions who had low Asian values, high Conformity and low Dissonance attitudes started high on well being but decreased as race-related stress increased. These findings underscore the importance of how racial identity statuses, Asian values and ethnic identity jointly and uniquely explain and moderate the effects of race-related stress on positive well-being. Implications for future research and clinical practice are discussed. PMID:20396592

The impact of racial identity, ethnic identity, asian values and race-related stress on Asian Americans and Asian international college students' psychological well-being.

PubMed

Iwamoto, Derek Kenji; Liu, William Ming

2010-01-01

The current study investigated the direct and moderating effects of racial identity, ethnic identity, Asian values, and race-related stress on positive psychological well-being among 402 Asian American and Asian international college students. Results revealed that the racial identity statuses Internalization, Immersion-Emersion, Dissonance, Asian values and Ethnic Identity Affirmation and Belonging were significant predictors of well-being. Asian values, Dissonance and Conformity were found to moderate the relationship between race-related stress on well-being. Specifically, individuals in low race-related stress conditions who had low Asian values, high Conformity and low Dissonance attitudes started high on well being but decreased as race-related stress increased. These findings underscore the importance of how racial identity statuses, Asian values and ethnic identity jointly and uniquely explain and moderate the effects of race-related stress on positive well-being. Implications for future research and clinical practice are discussed.

Math achievement is important, but task values are critical, too: examining the intellectual and motivational factors leading to gender disparities in STEM careers.

PubMed

Wang, Ming-Te; Degol, Jessica; Ye, Feifei

2015-01-01

Although young women now obtain higher course grades in math than boys and are just as likely to be enrolled in advanced math courses in high school, females continue to be underrepresented in some Science, Technology, Engineering, and Mathematics (STEM) occupations. This study drew on expectancy-value theory to assess (1) which intellectual and motivational factors in high school predict gender differences in career choices and (2) whether students' motivational beliefs mediated the pathway of gender on STEM career via math achievement by using a national longitudinal sample in the United States. We found that math achievement in 12th grade mediated the association between gender and attainment of a STEM career by the early to mid-thirties. However, math achievement was not the only factor distinguishing gender differences in STEM occupations. Even though math achievement explained career differences between men and women, math task value partially explained the gender differences in STEM career attainment that were attributed to math achievement. The identification of potential factors of women's underrepresentation in STEM will enhance our ability to design intervention programs that are optimally tailored to female needs to impact STEM achievement and occupational choices.

Math achievement is important, but task values are critical, too: examining the intellectual and motivational factors leading to gender disparities in STEM careers

PubMed Central

Wang, Ming-Te; Degol, Jessica; Ye, Feifei

2015-01-01

Although young women now obtain higher course grades in math than boys and are just as likely to be enrolled in advanced math courses in high school, females continue to be underrepresented in some Science, Technology, Engineering, and Mathematics (STEM) occupations. This study drew on expectancy-value theory to assess (1) which intellectual and motivational factors in high school predict gender differences in career choices and (2) whether students’ motivational beliefs mediated the pathway of gender on STEM career via math achievement by using a national longitudinal sample in the United States. We found that math achievement in 12th grade mediated the association between gender and attainment of a STEM career by the early to mid-thirties. However, math achievement was not the only factor distinguishing gender differences in STEM occupations. Even though math achievement explained career differences between men and women, math task value partially explained the gender differences in STEM career attainment that were attributed to math achievement. The identification of potential factors of women’s underrepresentation in STEM will enhance our ability to design intervention programs that are optimally tailored to female needs to impact STEM achievement and occupational choices. PMID:25741292

Assessing organizational performance in intensive care units: a French experience.

PubMed

Minvielle, Etienne; Aegerter, Philippe; Dervaux, Benoît; Boumendil, Ariane; Retbi, Aurélia; Jars-Guincestre, Marie Claude; Guidet, Bertrand

2008-06-01

The objective of the study was to assess and to explain variation of organizational performance in intensive care units (ICUs). This was a prospective multicenter study. The study involved 26 ICUs located in the Paris area, France, participating in a regional database. Data were collected through answers of 1000 ICU personnel to the Culture, Organization, and Management in Intensive Care questionnaire and from the database. Organizational performance was assessed through a composite score related to 5 dimensions: coordination and adaptation to uncertainty, communication, conflict management, organizational change, and organizational learning, Skills developed in relationship with patients and their families. Statistical comparisons between ICUs were performed by analysis of variance with a Scheffé pairwise procedure. A multilevel regression model was used to analyze both individual and structural variables explaining differences of ICU's organizational performance. The organizational performance score differed among ICUs. Some cultural values were negatively correlated with a high level of organizational performance, suggesting improvement potential. Several individual and structural factors were also related to the quality of ICU organization, including absence of burnout, older staff, satisfaction to work, and high workload (P < .02 for each). A benchmarking approach can be used by ICU managers to assess the organizational performance of their ICU based on a validated questionnaire. Differences are mainly explained by cultural values and individual well-being factors, introducing new requirements for managing human resources in ICUs.

An Introduction to the New SI

ERIC Educational Resources Information Center

Knotts, Sandra; Mohr, Peter J.; Phillips, William D.

2017-01-01

Plans are under way to redefine the International System of Units (SI) around 2018. The new SI specifies the values of certain physical constants to define units. This article explains the new SI in order to provide a resource for high school teachers as well as for advanced students already familiar with the pre-2018 SI.

Test of Economic Literacy: Discussion Guide and Rationale.

ERIC Educational Resources Information Center

Soper, John C.

Part of a series which offers educational resources and teaching techniques related to major social issues to high school social studies teachers, the booklet describes and reproduces a test measuring students' economic literacy. Part I is the test manual, which explains the objectives, value, development, and two-form structure of the test. It…

Resolving the inconsistency between the ice giants and cometary D/H ratios

NASA Astrophysics Data System (ADS)

Ali-Dib, M.; Mousis, O.; Petit, J.-M.; Lunine, J. I.

2014-12-01

The properties and chemical compositions of giant planets strongly depend on their formation locations. The formation mechanisms of the ice giants Uranus and Neptune, and their elemental and isotopic compositions, have long been debated. The density of solids in the outer protosolar nebula is too low to explain their formation within a timescale consistent with the presence of the gaseous protoplanetary disk, and spectroscopic observations show that both planets are highly enriched in carbon, very poor in nitrogen, and the ices from which they originally formed might had deuterium-to-hydrogen ratios lower than the predicted cometary value, unexplained properties observed in no other planets. Here we show that all these properties can be explained naturally if Uranus and Neptune both formed at the carbon monoxide iceline location, namely the region where this gas condensates in the protosolar nebula. This outer region of the protosolar nebula intrinsically has enough surface density to form both planets from carbon-rich solids but nitrogen-depleted gas, in abundances consistent with their observed values. Water rich interiors originating mostly from transformed CO ices reconcile the D/H value observed in Uranus and Neptune with the cometary value.

A systematic approach to parameter selection for CAD-virtual reality data translation using response surface methodology and MOGA-II.

PubMed

Abidi, Mustufa Haider; Al-Ahmari, Abdulrahman; Ahmad, Ali

2018-01-01

Advanced graphics capabilities have enabled the use of virtual reality as an efficient design technique. The integration of virtual reality in the design phase still faces impediment because of issues linked to the integration of CAD and virtual reality software. A set of empirical tests using the selected conversion parameters was found to yield properly represented virtual reality models. The reduced model yields an R-sq (pred) value of 72.71% and an R-sq (adjusted) value of 86.64%, indicating that 86.64% of the response variability can be explained by the model. The R-sq (pred) is 67.45%, which is not very high, indicating that the model should be further reduced by eliminating insignificant terms. The reduced model yields an R-sq (pred) value of 73.32% and an R-sq (adjusted) value of 79.49%, indicating that 79.49% of the response variability can be explained by the model. Using the optimization software MODE Frontier (Optimization, MOGA-II, 2014), four types of response surfaces for the three considered response variables were tested for the data of DOE. The parameter values obtained using the proposed experimental design methodology result in better graphics quality, and other necessary design attributes.

Evaluation of Sorption Mechanism of Pb (II) and Ni (II) onto Pea (Pisum sativum) Peels.

PubMed

Haq, Atta Ul; Saeed, Muhammad; Anjum, Salma; Bokhari, Tanveer Hussain; Usman, Muhammad; Tubbsum, Saiqa

2017-07-01

The present study was carried out to know the sorption mechanism of Pb (II) and Ni (II) in aqueous solution using pea peels under the influence of sorbent dose, pH, temperature, initial metal ion concentration and contact time. SEM and FTIR were used for characterization of pea peels. The study showed that solution pH affects sorption process and the optimum pH for Pb (II) was 6.0 while for that of Ni (II) was 7.0. Pseudo-second order kinetic model was found to be the most suitable one to explain the kinetic data not only due to high value of R 2 (>0.99) but also due to the closeness of the experimental sorption capacity values to that of calculated sorption capacity values of pseudo second order kinetic model. It can be seen from the results that Freundlich isotherm explains well the equilibrium data (R 2 >0.99). Sorption capacity of pea peels was 140.84 and 32.36 for Pb (II) and Ni (II) mg g -1 respectively. The positive value of ΔH° and negative values of ΔG° suggest that sorption of Pb (II) and Ni (II) onto pea peels is an endothermic and spontaneous process respectively.

CaCO3 Precipitation in Multilayered Cyanobacterial Mats: Clues to Explain the Alternation of Micrite and Sparite Layers in Calcareous Stromatolites

PubMed Central

Kaźmierczak, Józef; Fenchel, Tom; Kühl, Michael; Kempe, Stephan; Kremer, Barbara; Łącka, Bożena; Małkowski, Krzysztof

2015-01-01

Marine cyanobacterial mats were cultured on coastal sediments (Nivå Bay, Øresund, Denmark) for over three years in a closed system. Carbonate particles formed in two different modes in the mat: (i) through precipitation of submicrometer-sized grains of Mg calcite within the mucilage near the base of living cyanobacterial layers, and (ii) through precipitation of a variety of mixed Mg calcite/aragonite morphs in layers of degraded cyanobacteria dominated by purple sulfur bacteria. The δ13C values were about 2‰ heavier in carbonates from the living cyanobacterial zones as compared to those generated in the purple bacterial zones. Saturation indices calculated with respect to calcite, aragonite, and dolomite inside the mats showed extremely high values across the mat profile. Such high values were caused by high pH and high carbonate alkalinity generated within the mats in conjunction with increased concentrations of calcium and magnesium that were presumably stored in sheaths and extracellular polymer substances (EPS) of the living cyanobacteria and liberated during their post-mortem degradation. The generated CaCO3 morphs were highly similar to morphs reported from heterotrophic bacterial cultures, and from bacterially decomposed cyanobacterial biomass emplaced in Ca-rich media. They are also similar to CaCO3 morphs precipitated from purely inorganic solutions. No metabolically (enzymatically) controlled formation of particular CaCO3 morphs by heterotrophic bacteria was observed in the studied mats. The apparent alternation of in vivo and post-mortem generated calcareous layers in the studied cyanobacterial mats may explain the alternation of fine-grained (micritic) and coarse-grained (sparitic) laminae observed in modern and fossil calcareous cyanobacterial microbialites as the result of a probably similar multilayered mat organization. PMID:25761263

Titan Crossing a 5:1 MMR with Iapetus : Constraining the Tidal Recession of Titan and Giving an Explanation for Lapetus' Current Orbit

NASA Astrophysics Data System (ADS)

POLYCARPE, William; Lainey, Valery; Vienne, Alain; Noyelles, Benoît; Saillenfest, Melaine; Rambaux, Nicolas

2018-04-01

Iapetus orbits Saturn with an orbtial eccentricity of 3% and possesses an constant tilt to its local Laplace plane of around 7°, both elements are today poorly explained. The objective of the this work is to investigate if these orbtial characteristics may be explained in the frame of rapid tidal migration in the saturnian system [Lainey et al., 2012, 2017] [Fuller et al. 2016]. We present several sets of numerical simulations of a past 5:1 mean motion resonance crossing between Titan and Iapetus. Iapetus was placed initially on its local Laplace plane with a circular orbit. Simulations show that the outcomes of this resonance are very dependent on the migration speed of Titan, and therefore on the effective quality factor Q of Saturn. Iapetus will generally be ejected of the system due to this resonance when the migration is too slow, typically Q higher than 1500. Lower values allow Iapetus to survive with an eccentricity of a few percent, consistent with today's value. This resonance would also act on the inclination and can bring the tilt up to several degrees, and even reach 7° and more on rare occasions. It seems, in general, that the current value of the eccentricity can be easily explained by this resonance. On the other hand the tilt is more difficult to obtain for fast tidal migration (Q lower than 20), but high values are possible for medium migration rate (typically Q between 200 and 1500).

The Value of Assessment and Accreditation for Hospitality and Tourism Graduate Education

ERIC Educational Resources Information Center

Roberson, Richard D., Jr.

2010-01-01

Graduate education in hospitality is a growing field with a number of different approaches and philosophies which inform the decisions and directions put forth by program administrators. A case study explains the methods and justifications used by one institution to conduct a self assessment to assure high quality graduate hospitality education.…

Explanation of Educational and Cultural Dimensions of Globalization in the Views of Ayatollah Javadi-Amoli

ERIC Educational Resources Information Center

Soltaninejad, Najme; Keshtiaray, Narges; Vaezi, Seyed Hossein

2017-01-01

Globalization is a multi-dimensional phenomenon as it leads to high mobility in social, political, economic and value fields and besides reduction of the gap between time and place presents new interpretations of politics, economy, culture, government, authority and security. The present study aimed to explain the educational and cultural…

Techniques for Motivating Interest in Reading for the Disadvantaged High School Student.

ERIC Educational Resources Information Center

Usova, George M.

Many reasons may be offered to explain why the disadvantaged have little interest in reading. Among these are: attitudes inherent in the family, an inability to afford reading material, a failure to perceive practical value in reading, a limited experiential background that limits understanding, and a lack of interesting and meaningful reading…

Relationship between neck circumference, insulin resistance and arterial stiffness in overweight and obese subjects.

PubMed

Fantin, Francesco; Comellato, Gabriele; Rossi, Andrea P; Grison, Elisa; Zoico, Elena; Mazzali, Gloria; Zamboni, Mauro

2017-09-01

Background Only a few studies have investigated the relationship between neck circumference and cardiometabolic risk. The aim of this study was to assess the relationships between neck circumference, waist circumference, metabolic variables and arterial stiffness in a group of overweight and obese subjects evaluating a possible independent role of neck circumference in determining arterial stiffness. Methods and results We studied 95 subjects (53 women) with an age range of 20-77 years and body mass index range from 25.69 to 47.04 kg/m 2 . In each subject we evaluated body mass index, waist, hip and neck circumference, systolic and diastolic blood pressure, insulin, fasting glucose, cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol and triglycerides. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWVcf) and carotid-radial pulse wave velocity (PWVcr). Both PWVcf and PWVcr were higher in subjects with high values of neck circumference compared with subjects with normal values of neck circumference. Subjects with high values of neck circumference and abdominal obesity presented higher values of mean arterial pressure, PWVcr and homeostasis model assessment (HOMA) index and lower values of high-density lipoprotein than subjects with only abdominal obesity. Two models of stepwise multiple regression were performed in order to evaluate the combined effect of independent variables on arterial stiffness. In the first model PWVcf was considered a dependent variable, and age, gender, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, waist circumference, neck circumference, HOMA index and the use of anti-hypertensive medications were considered independent variables. Age, systolic blood pressure, triglycerides and waist circumference were significant predictors of PWVcf, explaining 65% of its variance. In the second model, in which PWVcr was considered a dependent variable, neck circumference and gender were significant predictors of PWVcr, explaining 24% of its variance. Conclusions These findings emphasise the need to measure not only waist but even neck circumference to better stratify and identify individuals at increased cardiometabolic risk, as upper-body subcutaneous fat is a novel, easily measured fat depot.

A study of temporal dynamics and spatial variability of power frequency electromagnetic fields in Saint-Petersburg

NASA Astrophysics Data System (ADS)

Sturman, V. I.

2018-01-01

This paper studies spatial distribution and temporal dynamics of power frequency electric and magnetic fields in Saint-Petersburg. It was determined that sanitary-protection and exclusion zones of the standard size high-voltage transmission lines (HVTL) do not always ensure maximum allowable limits of the electrical field depression. A dependence of the electric field strength on meteorological factors was defined. A series of sources create a city-wide background for magnetic fields. That said, the heavier the man-caused load is, the higher the mean values of magnetic induction are. Abnormally high values of magnetic induction are explained by the influence of underground electric cables.

A Review of Evidence for High Life Coefficients on Propeller and Rotor Blades Under Static Thrust Conditions with Some New Experimental Results

NASA Technical Reports Server (NTRS)

Talbot, Peter D.; Meyer, Mark; Branum, Lonnie; Burks, John S. (Technical Monitor)

1994-01-01

Interest has increased recently in the thrust-producing capability of rotors at very high collective pitch angles. An early reference noted this behaviour in rotors and offered alternative models for section lift characteristics to explain it. The same phenomenon was coincidentally noted and used in a propeller code, resulting in very good correlation with static thrust data. The proposed paper will present experimental data demonstrating the pronounced persistence of thrust for propellers at increasing collective pitch angles. Comparisons with blade element/momentum theory will be made. These results are expected to point to the need to define (ultimately to explain) aerodynamic lift and drag behaviour in a rotating environment. Experimental measurements made by the U.S. Army Aeroflightdynamics Directorate at the Ames Research Center have shown that locally measured normal force coefficients along the span of a highly twisted rotor blade continue to increase at high values of collective pitch. In some cases these coefficients exceed expected values for the same type of airfoil tested under two dimensional conditions. To date no one to the authors' knowledge has defined the variation of C(n) with pitch for very high angles (to 45 deg) in a rotating environment and for a blade of reasonably high aspect ratio; however, total propeller thrust measurements support the idea that stalling does not occur in the same way as on a wing. This paper will present experimental data in the form of surface pressure distributions as well as flow visualization (microtufts) to explore the aerodynamic behavior of the rotating airfoil at high values of blade incidence. This paper also reviews experimental evidence and infers some high lift coefficient behavior from it. Comparisons between predicted thrust, utilizing modified airfoil characteristics and a blade element model, and measured thrust for both rotors and propellers that cover the extremes of collective pitch are shown and discussed.

PUMPING THE ECCENTRICITY OF EXOPLANETS BY TIDAL EFFECT

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

Correia, Alexandre C. M.; Boue, Gwenaeel; Laskar, Jacques, E-mail: correia@ua.pt

2012-01-10

Planets close to their host stars are believed to undergo significant tidal interactions, leading to a progressive damping of the orbital eccentricity. Here we show that when the orbit of the planet is excited by an outer companion, tidal effects combined with gravitational interactions may give rise to a secular increasing drift on the eccentricity. As long as this secular drift counterbalances the damping effect, the eccentricity can increase to high values. This mechanism may explain why some of the moderate close-in exoplanets are observed with substantial eccentricity values.

Response to "Comment on `Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties'" [AIP Advances 8, 039101 (2018)

NASA Astrophysics Data System (ADS)

Song, Meng; Xu, Peng; Song, Yenan; Wang, Xu; Li, Zhenhua; Shang, Xuefu; Wu, Huizhen; Zhao, Pei; Wang, Miao

2018-03-01

In this response, we explain the points mentioned by R. Rani and R. Bhatia in their Comment for our previous paper [AIP Advances 5, 097130 (2015)], that the high value of β obtained in Song et al. [AIP Advances 5, 097130 (2015)] is misleading because it does not corroborate with the obtained Jmax, and the obtained value of Jmax is "low" in the mentioned study as compared to the reported values [J. Appl. Phys. 111, 044307 (2012) & Appl. Phys. Lett. 102, 033102 (2013)]. For the high value of β, the obtained current Jmax is corroborated but such high value is mainly due to the multistage effect when CNTs are deposited on the rough surface of reduced graphene. For the "low" Jmax, although this is true when compared with Sameera et al. [J. Appl. Phys. 111, 044307 (2012) and Appl. Phys. Lett. 102, 033102 (2013)], but we believe that our value is a generally common value when compared with other reports [Diam. Relat. Mater. 47, 1 (2014); J. Alloys Compd. 610, 659 (2014); J. Nanomater. 2013, 5239 (2013)] using the similar method as described in our paper. Therefore, the conclusions from the experimental results on field emission performance of CNT/graphene composite materials in our paper are reliable.

Origin of Lα{sup x} satellite in the light rare earths on the basis of plasmon theory

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

Jain, Manjula, E-mail: rainbow-mjain@yahoo.co.in; Shrivastava, B. D., E-mail: rashmibasant@gmail.com

The origin of most of the X-ray satellites can be explained on the basis of multiple ionization theory. However, there are several satellites which can be explained on the basis of plasmon theory. When a plasmon is excited during the X-ray emission process, one can get a low energy satellite because energy is used up in exciting the plasmon oscillations in the electron gas. A plasmon on decay can also transfer its energy to the transiting electron which subsequently fills the core vacancy giving rise to a high energy satellite. In our laboratory, a new high energy satellite Lα{sup x}more » has been observed in the Lα - emission spectra of the oxides of some light rare earths on the high energy side of the diagram line Lα{sub 1}. In the present paper, the origin of this high energy satellite has been explained using the theory of plasma oscillations in solids. The energy separation of the satellite from the emission line Lα{sub 1} has been calculated and then compared with the theoretical separation based on the plasmon theory. The agreement between the theoretical and experimental values is found to be good. Hence, the observed satellite can be designated as plasmon satellite.« less

Education effects on authoritarian-libertarian values: a question of socialization.

PubMed

Stubager, Rune

2008-06-01

Over the past decades an authoritarian-libertarian value dimension has become increasingly important to electoral behaviour across western countries. Previous analyses have shown that education is the most important social antecedent of individuals' positions on this value dimension; high education groups tend towards the libertarian pole and low education groups tend towards the authoritarian pole. It remains an open question, however, what aspects of education cause this relationship. The article examines a range of explanatory models: a psychodynamic, a cognitive, a socialization, and an allocation effects model. The results strongly favour the socialization model in which the relationship between education and authoritarian-libertarian values is explained as a result of differences in the value sets transferred to students in different educational milieus. The value differences between the educational groups should thus not be seen as reflecting economic differences between the groups but rather as the result of a more fundamental value conflict.

Trait Values, Not Trait Plasticity, Best Explain Invasive Species' Performance in a Changing Environment

PubMed Central

Matzek, Virginia

2012-01-01

The question of why some introduced species become invasive and others do not is the central puzzle of invasion biology. Two of the principal explanations for this phenomenon concern functional traits: invasive species may have higher values of competitively advantageous traits than non-invasive species, or they may have greater phenotypic plasticity in traits that permits them to survive the colonization period and spread to a broad range of environments. Although there is a large body of evidence for superiority in particular traits among invasive plants, when compared to phylogenetically related non-invasive plants, it is less clear if invasive plants are more phenotypically plastic, and whether this plasticity confers a fitness advantage. In this study, I used a model group of 10 closely related Pinus species whose invader or non-invader status has been reliably characterized to test the relative contribution of high trait values and high trait plasticity to relative growth rate, a performance measure standing in as a proxy for fitness. When grown at higher nitrogen supply, invaders had a plastic RGR response, increasing their RGR to a much greater extent than non-invaders. However, invasive species did not exhibit significantly more phenotypic plasticity than non-invasive species for any of 17 functional traits, and trait plasticity indices were generally weakly correlated with RGR. Conversely, invasive species had higher values than non-invaders for 13 of the 17 traits, including higher leaf area ratio, photosynthetic capacity, photosynthetic nutrient-use efficiency, and nutrient uptake rates, and these traits were also strongly correlated with performance. I conclude that, in responding to higher N supply, superior trait values coupled with a moderate degree of trait variation explain invasive species' superior performance better than plasticity per se. PMID:23119098

Cultural values and population health: a quantitative analysis of variations in cultural values, health behaviours and health outcomes among 42 European countries.

PubMed

Mackenbach, Johan P

2014-07-01

Variations in 'culture' are often invoked to explain cross-national variations in health, but formal analyses of this relation are scarce. We studied the relation between three sets of cultural values and a wide range of health behaviours and health outcomes in Europe. Cultural values were measured according to Inglehart׳s two, Hofstede׳s six, and Schwartz׳s seven dimensions. Data on individual and collective health behaviours (30 indicators of fertility-related behaviours, adult lifestyles, use of preventive services, prevention policies, health care policies, and environmental policies) and health outcomes (35 indicators of general health and of specific health problems relating to fertility, adult lifestyles, prevention, health care, and violence) in 42 European countries around the year 2010 were extracted from harmonized international data sources. Multivariate regression analysis was used to relate health behaviours to value orientations, controlling for socioeconomic confounders. In univariate analyses, all scales are related to health behaviours and most scales are related to health outcomes, but in multivariate analyses Inglehart׳s 'self-expression' (versus 'survival') scale has by far the largest number of statistically significant associations. Countries with higher scores on 'self-expression' have better outcomes on 16 out of 30 health behaviours and on 19 out of 35 health indicators, and variations on this scale explain up to 26% of the variance in these outcomes in Europe. In mediation analyses the associations between cultural values and health outcomes are partly explained by differences in health behaviours. Variations in cultural values also appear to account for some of the striking variations in health behaviours between neighbouring countries in Europe (Sweden and Denmark, the Netherlands and Belgium, the Czech Republic and Slovakia, and Estonia and Latvia). This study is the first to provide systematic and coherent empirical evidence that differences between European countries in health behaviours and health outcomes may partly be determined by variations in culture. Paradoxically, a shift away from traditional 'survival' values seems to promote behaviours that increase longevity in high income countries. Copyright © 2014 Elsevier Ltd. All rights reserved.

Analysis of the causes of discrepancies in troponin I concentrations as measured by ARCHITECT High-Sensitive Troponin I ST and STACIA CLEIA cTnI.

PubMed

Kondo, Takashi; Kobayashi, Daisuke; Mochizuki, Maki; Asanuma, Kouichi; Takahashi, Satoshi

2017-01-01

Background Recently developed reagents for the highly sensitive measurement of cardiac troponin I are useful for early diagnosis of acute coronary syndrome. However, differences in measured values between these new reagents and previously used reagents have not been well studied. In this study, we aimed to compare the values between ARCHITECT High-Sensitive Troponin I ST (newly developed reagents), ARCHITECT Troponin I ST and STACIA CLEIA cardiac troponin I (two previously developed reagent kits). Methods Gel filtration high-performance liquid chromatography was used to analyse the causes of differences in measured values. Results The measured values differed between ARCHITECT High-Sensitive Troponin I ST and STACIA CLEIA cardiac troponin I reagents (r = 0.82). Cross-reactivity tests using plasma with added skeletal-muscle troponin I resulted in higher reactivity (2.17-3.03%) for the STACIA CLEIA cardiac troponin I reagents compared with that for the ARCHITECT High-Sensitive Troponin I ST reagents (less than 0.014%). In addition, analysis of three representative samples using gel filtration high-performance liquid chromatography revealed reagent-specific differences in the reactivity against each cardiac troponin I complex; this could explain the differences in values observed for some of the samples. Conclusion The newly developed ARCHITECT High-Sensitive Troponin I ST reagents were not affected by the presence of skeletal-muscle troponin I in the blood and may be useful for routine examinations.

Experiencing nature in special places: surveys in North-Central region

Treesearch

Herbert W. Schroeder

2002-01-01

The experience people have in natural environments can be very important to them, even though these experiences are sometimes hard to categorize and measure. In a series of qualitative surveys, I asked people to describe special outdoor places and explain in their own words what these places meant to them. Their responses revealed many similarities in the highly valued...

Heritability of high sugar consumption through drinks and the genetic correlation with substance use.

PubMed

Treur, Jorien L; Boomsma, Dorret I; Ligthart, Lannie; Willemsen, Gonneke; Vink, Jacqueline M

2016-10-01

High sugar consumption contributes to the rising prevalence of obesity. Sugar can have rewarding effects that are similar to, but less strong than, the effects of addictive substances. People who consume large amounts of sugar also tend to use more addictive substances, but it is unclear whether this is due to shared genetic or environmental risk factors. We examined whether there are genetic influences on the consumption of sugar-containing drinks and whether genetic factors can explain the association with substance use. The frequency of consumption of sugar-containing drinks (e.g., cola, soft drinks, and energy drinks) and addictive substances (nicotine, caffeine, alcohol, cannabis, and illicit drugs) was obtained for 8586 twins who were registered at the Netherlands Twin Register (women: 68.7%; mean ± SD age: 33.5 ± 15.3 y). Participants were categorized as high or low sugar consumers (>1 compared with ≤1 SD above daily consumption in grams) and as high or low substance users (≥2 compared with <2 substances). Through bivariate genetic modeling, genetic and environmental influences on sugar consumption, substance use, and their association were estimated. Genetic factors explained 48% of the variation in high sugar consumption, whereas unique environmental factors explained 52%. For high substance use, these values were 62% and 38%, respectively. There was a moderate phenotypic association between high sugar consumption and high substance use (r = 0.2), which was explained by genetic factors (59%) and unique environmental factors (41%). The positive association between high sugar consumption and high substance use was partly due to unique environmental factors (e.g., social situations). Genetic factors were also of influence, suggesting that neuronal circuits underlying the development of addiction and obesity are related. Further research is needed to identify genes that influence sugar consumption and those that overlap with substance use. © 2016 American Society for Nutrition.

Controls on Highly Siderophile Element Concentrations in Martian Basalt: Sulfide Saturation and Under-Saturation

NASA Technical Reports Server (NTRS)

Righter, Kevin

2009-01-01

Highly siderophile elements (HSE; Re, Au and the platinum group elements) in shergottites exhibit a wide range from very high, similar to the terrestrial mantle, to very low, similar to sulfide saturated mid ocean ridge basalt (e.g., [1]). This large range has been difficult to explain without good constraints on sulfide saturation or under-saturation [2]. A new model for prediction of sulfide saturation places new constraints on this problem [3]. Shergottite data: For primitive shergottites, pressure and temperature estimates are between 1.2-1.5 GPa, and 1350-1470 C [4]. The range of oxygen fugacities is from FMQ-2 to IW, where the amount of Fe2O3 is low and thus does not have a significant effect on the S saturation values. Finally, the bulk compositions of shergottites have been reported in many recent studies (e.g., [5]). All of this information will be used to test whether shergottites are sulfide saturated [3]. Modeling values and results: The database for HSE partition coefficients has been growing with many new data for silicates and oxides [6-8] to complement a large sulfide database [9- 11]. Combining these data with simple batch melting models allows HSE contents of mantle melts to be estimated for sulfide-bearing vs. sulfide-free mantle. Combining such models with fractional crystallization modeling (e.g., [12]) allows HSE contents of more evolved liquids to be modeled. Most primitive shergottites have high HSE contents (and low S contents) that can be explained by sulfide under-saturated melting of the mantle. An exception is Dhofar 019 which has high S contents and very low HSE contents suggesting sulfide saturation. Most evolved basaltic shergottites have lower S contents than saturation, and intermediate HSE contents that can be explained by olivine, pyroxene, and chromite fractionation. An exception is EET A79001 lithology B, which has very low HSE contents and S contents higher than sulfide saturation values . evidence for sulfide saturation during late fractional crystallization. These results show that shergottite HSE contents are controlled by silicates, oxides, and sulfides. In addition, the mantle producing the most primitive shergottites did not contain near chondritic relative ratios of the HSEs like the terrestrial mantle, and did not experience a late chondritic veneer.

Measurement of strains at high temperatures by means of electro-optics holography

NASA Astrophysics Data System (ADS)

Sciammarella, Cesar A.; Bhat, G.; Vaitekunas, Jeffrey

Electro-optics holographic-moire interferometry is used to measure strains at temperatures up to 1000 C. A description of the instrumentation developed to carry out the measurements is given. The data processing technique is also explained. Main problems encountered in recording patterns at high temperatures are analyzed and possible solutions are outlined. Optical results are compared with strain gage values obtained with instrumented specimens and with theoretical results. Very good agreement is found between optical, strain gage and theoretical results.

Measurement of strains at high temperatures by means of electro-optics holography

NASA Technical Reports Server (NTRS)

Sciammarella, Cesar A.; Bhat, G.; Vaitekunas, Jeffrey

1991-01-01

Electro-optics holographic-moire interferometry is used to measure strains at temperatures up to 1000 C. A description of the instrumentation developed to carry out the measurements is given. The data processing technique is also explained. Main problems encountered in recording patterns at high temperatures are analyzed and possible solutions are outlined. Optical results are compared with strain gage values obtained with instrumented specimens and with theoretical results. Very good agreement is found between optical, strain gage and theoretical results.

Arginine: Its pKa value revisited

PubMed Central

Fitch, Carolyn A; Platzer, Gerald; Okon, Mark; Garcia-Moreno E, Bertrand; McIntosh, Lawrence P

2015-01-01

Using complementary approaches of potentiometry and NMR spectroscopy, we have determined that the equilibrium acid dissociation constant (pKa value) of the arginine guanidinium group is 13.8 ± 0.1. This is substantially higher than that of ∼12 often used in structure-based electrostatics calculations and cited in biochemistry textbooks. The revised intrinsic pKa value helps explains why arginine side chains in proteins are always predominantly charged, even at pH values as great as 10. The high pKa value also reinforces the observation that arginine side chains are invariably protonated under physiological conditions of near neutral pH. This occurs even when the guanidinium moiety is buried in a hydrophobic micro-environment, such as that inside a protein or a lipid membrane, thought to be incompatible with the presence of a charged group. PMID:25808204

Effects of agricultural practices and vadose zone stratigraphy on nitrate concentration in ground water in Kansas, USA

USGS Publications Warehouse

Townsend, M.A.; Sleezer, R.O.; Macko, S.A.; ,

1996-01-01

Differences in nitrate-N concentrations in,around water in Kansas can be explained by variations in agricultural practices and vadose-zone stratigraphy. In northwestern Kansas, past use of a local stream for tailwater runoff from irrigation and high fertilizer applications for sugar-beet farming resulted in high nitrate-N concentrations (12-60 mg L-1; in both soil and ground water. Nitrogen isotope values from the soil and ground water range from +4 to +8? which is typical for a fertilizer source. In parts of south-central Kansas, the use of crop rotation and the presence of both continuous fine-textured layers and a reducing ground-water chemistry resulted in ground-water nitrate-N values of 10 mg L-1; in both soil and grounwater. Nitrogen isotope values of +3 to +7? indicate a fertilizer source. Crop rotation decreased nitrate-N values in the shallow ground water (9 m). However, deeper ground water showed increasing nitrate-N concentrations as a result of past farming practices.

Intra-annual variability of anatomical structure and δ13C values within tree rings of spruce and pine in alpine, temperate and boreal Europe

PubMed Central

Vaganov, Eugene A.; Skomarkova, Marina V.; Knohl, Alexander; Brand, Willi A.; Roscher, Christiane

2009-01-01

Tree-ring width, wood density, anatomical structure and 13C/12C ratios expressed as δ13C-values of whole wood of Picea abies were investigated for trees growing in closed canopy forest stands. Samples were collected from the alpine Renon site in North Italy, the lowland Hainich site in Central Germany and the boreal Flakaliden site in North Sweden. In addition, Pinus cembra was studied at the alpine site and Pinus sylvestris at the boreal site. The density profiles of tree rings were measured using the DENDRO-2003 densitometer, δ13C was measured using high-resolution laser-ablation-combustion-gas chromatography-infra-red mass spectrometry and anatomical characteristics of tree rings (tracheid diameter, cell-wall thickness, cell-wall area and cell-lumen area) were measured using an image analyzer. Based on long-term statistics, climatic variables, such as temperature, precipitation, solar radiation and vapor pressure deficit, explained <20% of the variation in tree-ring width and wood density over consecutive years, while 29–58% of the variation in tree-ring width were explained by autocorrelation between tree rings. An intensive study of tree rings between 1999 and 2003 revealed that tree ring width and δ13C-values of whole wood were significantly correlated with length of the growing season, net radiation and vapor pressure deficit. The δ13C-values were not correlated with precipitation or temperature. A highly significant correlation was also found between δ13C of the early wood of one year and the late wood of the previous year, indicating a carry-over effect of the growing conditions of the previous season on current wood production. This latter effect may explain the high autocorrelation of long-term tree-ring statistics. The pattern, however, was complex, showing stepwise decreases as well as stepwise increases in the δ13C between late wood and early wood. The results are interpreted in the context of the biochemistry of wood formation and its linkage to storage products. It is clear that the relations between δ13C and tree-ring width and climate are multi-factorial in seasonal climates. PMID:19653008

Sara Ruddick's theory of maternal thinking applied to traditional Irish mothering.

PubMed

Radosh, Polly F

2008-07-01

This paper uses Sara Ruddick's theory of maternal thinking to explain patterns of Irish mothering that developed in Ireland following the Great Famine of 1845-1852. Ruddick's central thesis, that maternal thinking develops strategies for preserving the life of the child, fostering the child's growth, and shaping an acceptable child, is applied to the intersecting influences of famine memory, religion, education, and emigration in post-famine Ireland. The strict, moralistic, and highly inhibiting features of Irish culture that dominated the nineteenth and twentieth centuries are traceable to patterns of mothering that developed after the famine. While Irish mothers are often blamed for instilling values that stressed sexual repression and guilt, other cultural factors influenced maternal thinking. Mothers did foster highly repressive moral values that encouraged permanent celibacy and delayed marriage. This paper examines the larger cultural features that derived from political oppression and the famine as they imprinted these values.

Added-values of high spatiotemporal remote sensing data in crop yield estimation

NASA Astrophysics Data System (ADS)

Gao, F.; Anderson, M. C.

2017-12-01

Timely and accurate estimation of crop yield before harvest is critical for food market and administrative planning. Remote sensing derived parameters have been used for estimating crop yield by using either empirical or crop growth models. The uses of remote sensing vegetation index (VI) in crop yield modeling have been typically evaluated at regional and country scales using coarse spatial resolution (a few hundred to kilo-meters) data or assessed over a small region at field level using moderate resolution spatial resolution data (10-100m). Both data sources have shown great potential in capturing spatial and temporal variability in crop yield. However, the added value of data with both high spatial and temporal resolution data has not been evaluated due to the lack of such data source with routine, global coverage. In recent years, more moderate resolution data have become freely available and data fusion approaches that combine data acquired from different spatial and temporal resolutions have been developed. These make the monitoring crop condition and estimating crop yield at field scale become possible. Here we investigate the added value of the high spatial and temporal VI for describing variability of crop yield. The explanatory ability of crop yield based on high spatial and temporal resolution remote sensing data was evaluated in a rain-fed agricultural area in the U.S. Corn Belt. Results show that the fused Landsat-MODIS (high spatial and temporal) VI explains yield variability better than single data source (Landsat or MODIS alone), with EVI2 performing slightly better than NDVI. The maximum VI describes yield variability better than cumulative VI. Even though VI is effective in explaining yield variability within season, the inter-annual variability is more complex and need additional information (e.g. weather, water use and management). Our findings augment the importance of high spatiotemporal remote sensing data and supports new moderate resolution satellite missions for agricultural applications.

Knowledge Growth of Mathematics Teachers during Professional Activity Based on the Task of Lesson Explaining

ERIC Educational Resources Information Center

Peng, Aihui

2007-01-01

"Lesson explaining" has been developed in China from an evaluative resource to an effective form of teacher professional development with the value of emphasizing teacher reflective practice. This paper begins with a general description of lesson explaining. Then an example of "explaining" a mathematics lesson for teaching…

Percolation behavior of polymer/metal composites on modification of filler

NASA Astrophysics Data System (ADS)

Panda, M.; Srinivas, V.; Thakur, A. K.

2014-02-01

Polymer-metal composites with different fillers, such as nanocrystalline nickel (n-Ni), core shell n-Ni and nickel oxide (NiO)[n-Ni@NiO] were prepared under the same processing conditions with polyvinyledene fluoride matrix. The larger value of critical exponents (s and s') and percolation threshold (fc 0.30) for n-Ni@NiO composites as compared to n-Ni composites (fc 0.07) and a comparable effective dielectric constant (ɛeff 300) with low loss tangent (tan δ 0.1) at 100 Hz in case of percolative n-Ni@NiO composite was observed. The core shell structure [n-Ni@NiO] also shows a very high value of ɛeff 6000 with tan δ 8 at 40 Hz. The results have been explained by using boundary layer capacitor effect and the percolation theory. The difference in fc and critical exponents is attributed to NiO insulating layer that gives rise to different extent of continuumness at fc and have been explained with the help of Swiss cheese model.

Influence of neurobehavioral incentive valence and magnitude on alcohol drinking behavior

PubMed Central

Joseph, Jane E.; Zhu, Xun; Corbly, Christine R.; DeSantis, Stacia; Lee, Dustin C.; Baik, Grace; Kiser, Seth; Jiang, Yang; Lynam, Donald R.; Kelly, Thomas H.

2014-01-01

The monetary incentive delay (MID) task is a widely used probe for isolating neural circuitry in the human brain associated with incentive motivation. In the present functional magnetic resonance imaging (fMRI) study, 82 young adults, characterized along dimensions of impulsive sensation seeking, completed a MID task. fMRI and behavioral incentive functions were decomposed into incentive valence and magnitude parameters, which were used as predictors in linear regression to determine whether mesolimbic response is associated with problem drinking and recent alcohol use. Alcohol use was best explained by higher fMRI response to anticipation of losses and feedback on high gains in the thalamus. In contrast, problem drinking was best explained by reduced sensitivity to large incentive values in meso-limbic regions in the anticipation phase and increased sensitivity to small incentive values in the dorsal caudate nucleus in the feedback phase. Altered fMRI responses to monetary incentives in mesolimbic circuitry, particularly those alterations associated with problem drinking, may serve as potential early indicators of substance abuse trajectories. PMID:25261001

A test of the reward-value hypothesis.

PubMed

Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D

2017-03-01

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.

Modelling audiovisual integration of affect from videos and music.

PubMed

Gao, Chuanji; Wedell, Douglas H; Kim, Jongwan; Weber, Christine E; Shinkareva, Svetlana V

2018-05-01

Two experiments examined how affective values from visual and auditory modalities are integrated. Experiment 1 paired music and videos drawn from three levels of valence while holding arousal constant. Experiment 2 included a parallel combination of three levels of arousal while holding valence constant. In each experiment, participants rated their affective states after unimodal and multimodal presentations. Experiment 1 revealed a congruency effect in which stimulus combinations of the same extreme valence resulted in more extreme state ratings than component stimuli presented in isolation. An interaction between music and video valence reflected the greater influence of negative affect. Video valence was found to have a significantly greater effect on combined ratings than music valence. The pattern of data was explained by a five parameter differential weight averaging model that attributed greater weight to the visual modality and increased weight with decreasing values of valence. Experiment 2 revealed a congruency effect only for high arousal combinations and no interaction effects. This pattern was explained by a three parameter constant weight averaging model with greater weight for the auditory modality and a very low arousal value for the initial state. These results demonstrate key differences in audiovisual integration between valence and arousal.

Role of viscosity in the magnetic field effect on pyrene-DMA exciplex emission at different permittivities

NASA Astrophysics Data System (ADS)

Jana, Amit Kumar; Roy, Partha; Nath, Deb Narayan

2014-02-01

Effect of viscosity variation on the magnetic field effect in pyrene-N,N-dimethylaniline exciplex luminescence has been studied at different permittivity values. The data is compatible to the model of Krissinel et al. (1999) [10] reported earlier to explain the effect probing the escape yield of radical pairs. It is shown that the data can also be explained on the basis of a simple model. It is interesting to note that the present letter also demonstrates the positive slope of MFE with diffusivity at extremely high viscous condition as predicted by Krissinel et al. (1999) [10] which has not been observed in earlier experiments.

The Value of NJ School District Demographic Data in Explaining School District NJ ASK Grade 3 Language Arts and Mathematics Scores

ERIC Educational Resources Information Center

Turnamian, Peter G.

2012-01-01

This study examined the strength and direction of the relationship between 2009 NJ ASK 3 Language Arts and Mathematics scores and district social and demographic data (i.e., lone-parent household, level of parental education, and household income levels) found in the extant literature to influence student achievement on high-stakes standardized…

"You Would Not Believe What I Have to Go through to Prove My Intellectual Value!" Stereotype Management among Academically Successful Black Mathematics and Engineering Students

ERIC Educational Resources Information Center

McGee, Ebony O.; Martin, Danny B.

2011-01-01

Stereotype management is introduced to explain high achievement and resilience among 23 Black mathematics and engineering college students. Characterized as a tactical response to ubiquitous forms of racism and racialized experiences across school and non-school contexts, stereotype management emerged along overlapping paths of racial, gender, and…

Does Human Capital Theory Explain the Value of Higher Education? A South African Case Study

ERIC Educational Resources Information Center

van der Merwe, Alex

2010-01-01

A perennial debate in the economics of education is whether human capital or screening/signalling theories best explain the value of schooling and hence the private demand for, in particular, higher education. Human capital theory proposes that formal training such as that offered by higher education institutions improves the productive capacity…

Explaining worker strain and learning: how important are emotional job demands?

PubMed

Taris, Toon W; Schreurs, Paul J G

2009-05-01

This study examined the added value of emotional job demands in explaining worker well-being, relative to the effects of task characteristics, such as quantitative job demands, job control, and coworker support. Emotional job demands were expected to account for an additional proportion of the variance in well-being. Cross-sectional data were obtained from 11,361 female Dutch home care employees. Hierarchical stepwise regression analysis demonstrated that low control, low support and high quantitative demands were generally associated with lower well-being (as measured in terms of emotional exhaustion, dedication, professional accomplishment and learning). Moreover, high emotional demands were in three out of four cases significantly associated with adverse well-being, in these cases accounting for an additional 1-6% of the variance in the outcome variables. In three out of eight cases the main effects of emotional demands on well-being were qualified by support and control, such that high control and high support either buffered the adverse effects of high emotional demands on well-being or increased the positive effects thereof. All in all, high emotional demands are as important a risk factor for worker well-being as well-established concepts like low job control and high quantitative job demands.

Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae Majoris-like object

NASA Astrophysics Data System (ADS)

Kato, Taichi; Hambsch, Franz-Josef; Cook, Lewis M.

2018-05-01

We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal-tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.

Detection of the supercycle in V4140 Sagittarii: First eclipsing ER Ursae Majoris-like object

NASA Astrophysics Data System (ADS)

Kato, Taichi; Hambsch, Franz-Josef; Cook, Lewis M.

2018-06-01

We observed the deeply eclipsing SU UMa-type dwarf nova V4140 Sgr and established the very short supercycle of 69.7(3) d. There were several short outbursts between superoutbursts. These values, together with the short orbital period (0.06143 d), were similar to, but not as extreme as, those of ER UMa-type dwarf novae. The object is thus the first, long sought, eclipsing ER UMa-like object. This ER UMa-like nature can naturally explain the high (apparent) quiescent viscosity and unusual temperature profile in quiescence, which were claimed observational features against the thermal-tidal instability model. The apparently unusual outburst behavior can be reasonably explained by a combination of this ER UMa-like nature and the high orbital inclination, and there is no need to introduce mass transfer bursts from its donor star.

On the challenges of drawing conclusions from p-values just below 0.05

PubMed Central

2015-01-01

In recent years, researchers have attempted to provide an indication of the prevalence of inflated Type 1 error rates by analyzing the distribution of p-values in the published literature. De Winter & Dodou (2015) analyzed the distribution (and its change over time) of a large number of p-values automatically extracted from abstracts in the scientific literature. They concluded there is a ‘surge of p-values between 0.041–0.049 in recent decades’ which ‘suggests (but does not prove) questionable research practices have increased over the past 25 years.’ I show the changes in the ratio of fractions of p-values between 0.041–0.049 over the years are better explained by assuming the average power has decreased over time. Furthermore, I propose that their observation that p-values just below 0.05 increase more strongly than p-values above 0.05 can be explained by an increase in publication bias (or the file drawer effect) over the years (cf. Fanelli, 2012; Pautasso, 2010, which has led to a relative decrease of ‘marginally significant’ p-values in abstracts in the literature (instead of an increase in p-values just below 0.05). I explain why researchers analyzing large numbers of p-values need to relate their assumptions to a model of p-value distributions that takes into account the average power of the performed studies, the ratio of true positives to false positives in the literature, the effects of publication bias, and the Type 1 error rate (and possible mechanisms through which it has inflated). Finally, I discuss why publication bias and underpowered studies might be a bigger problem for science than inflated Type 1 error rates, and explain the challenges when attempting to draw conclusions about inflated Type 1 error rates from a large heterogeneous set of p-values. PMID:26246976

Suicide and changing values and beliefs in Ireland.

PubMed

Cleary, Anne; Brannick, Teresa

2007-01-01

This paper addresses some of the generalized theories explaining rising suicide rates in Ireland. The conclusion here is that linking suicide patterns to changing beliefs and values is problematic. Church attendance as well as adherence to traditional values remain high in this country compared to European levels, and variations in beliefs and values, especially rural/urban differences, do not fit with general explanations. Moreover, attitudes to value areas fluctuate in that justification for suicide--which showed an upward trend in the 1980s--was reversed in the 1990s, and this may have resulted from increased public focus and debate. Generalized explanations are unlikely to decipher complex phenomena such as suicidal behavior. Religious belief, if protective in relation to suicide, is unlikely to act alone. Social transformations have a differential impact depending on one's socio-economic positioning, which translates ideas of a general male vulnerability to suicide into focused areas of male distress.

Tribological characteristics of perfluoropolyether liquid lubricants under sliding conditions in high vacuum

NASA Technical Reports Server (NTRS)

Masuko, Masabumi; Jones, William R., Jr.; Helmick, Larry S.

1993-01-01

Tribological characteristics of three PFPE's (Fomblin Z, Demnum, and Krytox) were studied under high vacuum using a four-ball apparatus with 440C steel specimens. Fomblin Z and Demnum exhibited initial scuffing-like high friction whereas Krytox did not. Steady state friction with Fomblin Z was the lowest among the three oils. Frictional values for Demnum and Krytox were almost the same. The lowest wear rate in air was provided by Krytox regardless of load, and low wear rates in vacuum at high load were achieved with Krytox and Demnum. Results are explained by reactivity and pressure-viscosity characteristics of the oils.

Lithium isotopic systematics of submarine vent fluids from arc and back-arc hydrothermal systems in the western Pacific

NASA Astrophysics Data System (ADS)

Araoka, Daisuke; Nishio, Yoshiro; Gamo, Toshitaka; Yamaoka, Kyoko; Kawahata, Hodaka

2016-10-01

The Li concentration and isotopic composition (δ7Li) in submarine vent fluids are important for oceanic Li budget and potentially useful for investigating hydrothermal systems deep under the seafloor because hydrothermal vent fluids are highly enriched in Li relative to seawater. Although Li isotopic geochemistry has been studied at mid-ocean-ridge (MOR) hydrothermal sites, in arc and back-arc settings Li isotopic composition has not been systematically investigated. Here we determined the δ7Li and 87Sr/86Sr values of 11 end-member fluids from 5 arc and back-arc hydrothermal systems in the western Pacific and examined Li behavior during high-temperature water-rock interactions in different geological settings. In sediment-starved hydrothermal systems (Manus Basin, Izu-Bonin Arc, Mariana Trough, and North Fiji Basin), the Li concentrations (0.23-1.30 mmol/kg) and δ7Li values (+4.3‰ to +7.2‰) of the end-member fluids are explained mainly by dissolution-precipitation model during high-temperature seawater-rock interactions at steady state. Low Li concentrations are attributable to temperature-related apportioning of Li in rock into the fluid phase and phase separation process. Small variation in Li among MOR sites is probably caused by low-temperature alteration process by diffusive hydrothermal fluids under the seafloor. In contrast, the highest Li concentrations (3.40-5.98 mmol/kg) and lowest δ7Li values (+1.6‰ to +2.4‰) of end-member fluids from the Okinawa Trough demonstrate that the Li is predominantly derived from marine sediments. The variation of Li in sediment-hosted sites can be explained by the differences in degree of hydrothermal fluid-sediment interactions associated with the thickness of the marine sediment overlying these hydrothermal sites.

Effect of silane dilution on intrinsic stress in glow discharge hydrogenated amorphous silicon films

NASA Astrophysics Data System (ADS)

Harbison, J. P.; Williams, A. J.; Lang, D. V.

1984-02-01

Measurements of the intrinsic stress in hydrogenated amorphous silicon (a-Si : H) films grown by rf glow discharge decomposition of silane diluted to varying degrees in argon are presented. Films are found to grow under exceedingly high compressive stress. Low values of macroscopic film density and low stress values are found to correlate with high growth rate. An abrupt drop in stress occurs between 2 and 3% silane at precisely the point where columnar growth morphology appears. No corresponding abrupt change is noted in density, growth rate, or plasma species concentrations as determined by optical emissioin spectroscopy. Finally a model of diffusive incorporation of hydrogen or some gaseous impurity during growth into the bulk of the film behind the growing interface is proposed to explain the results.

Physico-chemical quality and homogeneity of folic acid and iron in enriched flour using principal component analysis.

PubMed

Soeiro, Bruno T; Boen, Thaís R; Wagner, Roger; Lima-Pallone, Juliana A

2009-01-01

The aim of the present work was to determine parameters of the corn and wheat flour matrix, such as protein, lipid, moisture, ash and carbohydrates, folic acid and iron contents. Three principal components explained 91% of the total variance. Wheat flours were characterized by high protein and moisture content. On the other hand, the corn flours had the greater carbohydrates, lipids and folic acid levels. The concentrations of folic acid were lower than the issued value for wheat flours. Nevertheless, corn flours presented extremely high values. The iron concentration was higher than that recommended in Brazilian legislation. Poor homogenization of folic acid and iron was observed in enriched flours. This study could be useful to help the governmental authorities in the enriched food programs evaluation.

A Categorization Model for Educational Values of the History of Mathematics. An Empirical Study

NASA Astrophysics Data System (ADS)

Wang, Xiao-qin; Qi, Chun-yan; Wang, Ke

2017-11-01

There is not a clear consensus on the categorization framework of the educational values of the history of mathematics. By analyzing 20 Chinese teaching cases on integrating the history of mathematics into mathematics teaching based on the relevant literature, this study examined a new categorization framework of the educational values of the history of mathematics by combining the objectives of high school mathematics curriculum in China. This framework includes six dimensions: the harmony of knowledge, the beauty of ideas or methods, the pleasure of inquiries, the improvement of capabilities, the charm of cultures, and the availability of moral education. The results show that this framework better explained the all-educational values of the history of mathematics that all teaching cases showed. Therefore, the framework can guide teachers to better integrate the history of mathematics into teaching.

Construct validity of the abbreviated mental test in older medical inpatients.

PubMed

Antonelli Incalzi, R; Cesari, M; Pedone, C; Carosella, L; Carbonin, P U

2003-01-01

To evaluate validity and internal structure of the Abbreviated Mental Test (AMT), and to assess the dependence of the internal structure upon the characteristics of the patients examined. Cross-sectional examination using data from the Italian Group of Pharmacoepidemiology in the Elderly (GIFA) database. Twenty-four acute care wards of Geriatrics or General Medicine. Two thousand eight hundred and eight patients consecutively admitted over a 4-month period. Demographic characteristics, functional status, medical conditions and performance on AMT were collected at discharge. Sensitivity, specificity and predictive values of the AMT <7 versus a diagnosis of dementia made according to DSM-III-R criteria were computed. The internal structure of AMT was assessed by principal component analysis. The analysis was performed on the whole population and stratified for age (<65, 65-80 and >80 years), gender, education (<6 or >5 years) and presence of congestive heart failure (CHF). AMT achieved high sensitivity (81%), specificity (84%) and negative predictive value (99%), but a low positive predictive value of 25%. The principal component analysis isolated two components: the former component represents the orientation to time and space and explains 45% of AMT variance; the latter is linked to memory and attention and explains 13% of variance. Comparable results were obtained after stratification by age, gender or education. In patients with CHF, only 48.3% of the cumulative variance was explained; the factor accounting for most (34.6%) of the variance explained was mainly related to the three items assessing memory. AMT >6 rules out dementia very reliably, whereas AMT <7 requires a second level cognitive assessment to confirm dementia. AMT is bidimensional and maintains the same internal structure across classes defined by selected social and demographic characteristics, but not in CHF patients. It is likely that its internal structure depends on the type of patients. The use of a sum-score could conceal some part of the information provided by the AMT. Copyright 2003 S. Karger AG, Basel

Dijets with 2, 1 or 0 rapidity gap: factorization breaking at the Tevatron

NASA Astrophysics Data System (ADS)

Bialas, A.; Peschanski, R.

2003-11-01

Central production cross-sections of hard dijets with 2, 1 or 0 rapidity gap at Tevatron are analyzed in terms of diffractive ("a la Good-Walker") and non-diffractive fluctuations of the incident particles. The observed large factorization breaking and the unexpected high value of the 2 to 1 gap cross-section ratio are explained in terms of scattering with and between the incident particles.

Evidence for k-dependent, in-plane anisotropy of the superconducting gap in Bi2Sr2CaCu2O8+δ

NASA Astrophysics Data System (ADS)

Wells, B. O.; Shen, Z. X.; Dessau, D. S.; Spicer, W. E.; Mitzi, D. B.; Lombardo, L.; Kapitulnik, A.; Arko, A. J.

1992-11-01

We find the superconducting gap in Bi2Sr2CaCu2O8+δ single crystals is anisotropic in k space by roughly a factor of 2 using angle-resolved photoemission spectroscopy. Matching the k-space symmetry of the gap values provides a stringent constraint on theories of the mechanism of high-temperature superconductivity. A review of the literature shows that many puzzling results can be explained by anisotropic gaps in the high-Tc cuprates.

Influence of load interactions on crack growth as related to state of stress and crack closure

NASA Technical Reports Server (NTRS)

Telesman, J.

1985-01-01

Fatigue crack propagation (FCP) after an application of a low-high loading sequence was investigated as a function of specimen thickness and crack closure. No load interaction effects were detected for specimens in a predominant plane strain state. However, for the plane stress specimens, initially high FCP rates after transition to a higher stress intensity range were observed. The difference in observed behavior was explained by examining the effect of the resulting closure stress intensity values on the effective stress intensity range.

Phenanthrene sorption with heterogeneous organic matter in a landfill aquifer material

USGS Publications Warehouse

Karapanagioti, H.K.; Sabatini, D.A.; Kleineidam, S.; Grathwohl, P.; Ligouis, B.

1999-01-01

Phenanthrene was used as a model chemical to study the sorption properties of Canadian River Alluvium aquifer material. Both equilibrium and kinetic sorption processes were evaluated through batch studies. The bulk sample was divided into subsamples with varying properties such as particle size, organic content, equilibration time, etc. in order to determine the effect of these properties on resulting sorption parameters. The data have been interpreted and the effect of experimental variables was quantified using the Freundlich isotherm model and a numerical solution of Fick's 2nd law in porous media. Microscopic organic matter characterization proved to be a valuable tool for explaining the results. Different organic matter properties and sorption mechanisms were observed for each soil subsample. Samples containing coal particles presented high Koc values. Samples with organic matter dominated by organic coatings on quartz grains presented low Koc values and contained a high percentage of fast sorption sites. The numerical solution of Fick's 2ndlaw requires the addition of two terms (fast and slow) in order to fit the kinetics of these heterogeneous samples properly. These results thus demonstrate the need for soil organic matter characterization in order to predict and explain the sorption properties of a soil sample containing heterogeneous organic matter and also the difficulty and complexity of modeling sorption in such samples.

Polarization recovery in lead zirconate titanate thin films deposited on nanosheets-buffered Si (001)

NASA Astrophysics Data System (ADS)

Chopra, Anuj; Bayraktar, Muharrem; Nijland, Maarten; ten Elshof, Johan E.; Bijkerk, Fred; Rijnders, Guus

2016-12-01

Fatigue behavior of Pb(Zr,Ti)O3 (PZT) films is one of the deterrent factors that limits the use of these films in technological applications. Thus, understanding and minimization of the fatigue behavior is highly beneficial for fabricating reliable devices using PZT films. We have investigated the fatigue behavior of preferentially oriented PZT films deposited on nanosheets-buffered Si substrates using LaNiO3 bottom and top electrodes. The films show fatigue of up to 10% at 100 kHz, whereas no fatigue has been observed at 1 MHz. This frequency dependence of the fatigue behavior is found to be in accordance with Dawber-Scott fatigue model that explains the origin of the fatigue as migration of oxygen vacancies. Interestingly, a partial recovery of remnant polarization up to ˜97% of the maximum value is observed after 4×109 cycles which can be further extended to full recovery by increasing the applied electric field. This full recovery is qualitatively explained using kinetic approach as a manifestation of depinning of domains walls. The understanding of the fatigue behavior and polarization recovery that is explained in this paper can be highly useful in developing more reliable PZT devices.

More Value through Greater Differentiation: Gender Differences in Value Beliefs about Math

ERIC Educational Resources Information Center

Gaspard, Hanna; Dicke, Anna-Lena; Flunger, Barbara; Schreier, Brigitte; Häfner, Isabelle; Trautwein, Ulrich; Nagengast, Benjamin

2015-01-01

Expectancy-value theory (Eccles et al., 1983) is a prominent approach to explaining gender differences in math-related academic choices, with value beliefs acting as an important explanatory factor. Expectancy-value theory defines 4 value components: intrinsic value, attainment value, utility value, and cost. The present study followed up on…

[Nurses are not into personal marketing: do history explain why?].

PubMed

Gentil, Rosana Chami

2009-01-01

Reflection on the nurse's personal marketing based on beliefs and values explained by the history of the main characters that care for patients. It brings to the surface reflections on the ambiguity between the social image of nursing and scientific, technological and humanistic knowledge developed over the time. It recognizes that there is still a fixation on the attributes relating to attitude and moral of the professionals to the detriment of having high regard for the technical and scientific knowledge. It verifies that the History of Nursing allows understanding that the fight against prejudice in the collective imagination lends weight to the social acceptance and recognition of this profession through the promotion of Nursing Science and the demonstration of its application in the professional practice.

The healthcare off-shoring industry in developing economies--institutional and economic foundations: an Indian case.

PubMed

Kshetri, Nir

2011-01-01

Industrialized world-based healthcare providers are increasingly off-shoring low-end healthcare services such as medical transcription, billing and insurance claims. High-skill medical jobs such as tele-imaging and tele-pathology are also being sub-contracted to developing countries. Despite its importance, little theory or research exists to explain what factors affect industry growth. The article's goals, therefore, are to examine economic processes associated with developing economies' shift from low- to high-value information technology enabled healthcare services, and to investigate how these differ in terms of legitimacy from regulative, normative and cognitive institutions in the sending country and how healthcare services differ from other services. This research is conceptual and theory-building. Broadly, its approach can be described as a positivistic epistemology. Anti off-shoring regulative, normative and cognitive pressures in the sending country are likely to be stronger in healthcare than in most business process outsourcing. Moreover, such pressures are likely to be stronger in high-value rather than in low-value healthcare off-shoring. The findings also indicate that off-shoring low-value healthcare services and emergent healthcare industries in a developing economy help accumulate implicit and tacit knowledge required for off-shoring high-value healthcare services. The approach lacks primary data and empirical documentation. The article helps in understanding industry drivers and its possible future direction. The findings help in understanding the lens through which various institutional actors in a sending country view healthcare service off-shoring. The article's value stems from its analytical context, mechanisms and processes associated with developing economies' shift to high-value healthcare off-shoring services.

The Relative Value of Skills, Knowledge, and Teaching Methods in Explaining Master of Business Administration (MBA) Program Return on Investment

ERIC Educational Resources Information Center

van Auken, Stuart; Wells, Ludmilla Gricenko; Chrysler, Earl

2005-01-01

In this article, the authors provide insight into alumni perceptions of Master of Business Administration (MBA) program return on investment (ROI). They sought to assess the relative value of skills, knowledge, and teaching methods in explaining ROI. By developing insight into the drivers of ROI, the real utility of MBA program ingredients can be…

Relationship among performance, carcass, and feed efficiency characteristics, and their ability to predict economic value in the feedlot.

PubMed

Retallick, K M; Faulkner, D B; Rodriguez-Zas, S L; Nkrumah, J D; Shike, D W

2013-12-01

A 4-yr study was conducted using 736 steers of known Angus, Simmental, or Simmental × Angus genetics to determine performance, carcass, and feed efficiency factors that explained variation in economic performance. Steers were pen fed and individual DMI was recorded using a GrowSafe automated feeding system (GrowSafe Systems Ltd., Airdrie, Alberta, Canada). Steers consumed a similar diet and received similar management each year. The objectives of this study were to: 1) determine current economic value of feed efficiency and 2) identify performance, carcass, and feed efficiency characteristics that predict: carcass value, profit, cost of gain, and feed costs. Economic data used were from 2011 values. Feed efficiency values investigated were: feed conversion ratio (FCR; feed to gain), residual feed intake (RFI), residual BW gain (RG), and residual intake and BW gain (RIG). Dependent variables were carcass value ($/steer), profit ($/steer), feed costs ($/steer • d(-1)), and cost of gain ($/kg). Independent variables were year, DMI, ADG, HCW, LM area, marbling, yield grade, dam breed, and sire breed. A 10% improvement in RG (P < 0.05) yielded the lowest cost of gain at $0.09/kg and highest carcass value at $17.92/steer. Carcass value increased (P < 0.05) as feed efficiency improved for FCR, RG, and RIG. Profit increased with a 10% improvement in feed efficiency (P < 0.05) with FCR at $34.65/steer, RG at $31.21/steer, RIG at $21.66/steer, and RFI at $11.47/steer. The carcass value prediction model explained 96% of the variation among carcasses and included HCW, marbling score, and yield grade. Average daily gain, marbling score, yield grade, DMI, HCW, and year born constituted 81% of the variation for prediction of profit. Eighty-five percent of the variation in cost of gain was explained by ADG, DMI, HCW, and year. Prediction equations were developed that excluded ADG and DMI, and included feed efficiency values. Using these equations, cost of gain was explained primarily by FCR (R(2) = 0.71). Seventy-three percent of profitability was explained, with 55% being accounted for by RG and marbling. These prediction equations represent the relative importance of factors contributing to economic success in feedlot cattle based on current prices.

The development of the Professional Values Model in Nursing.

PubMed

Kaya, Ayla; Boz, İlkay

2017-01-01

One of the most important criteria for professionalism is accumulation of knowledge that is usable in professional practice. Nursing models and theories are important elements of accumulating nursing knowledge and have a chance to guarantee the ethical professional practice. In recent years, there has been an increase in the use of models in nursing research and newly created terminology has started to be used in nursing. In this study, a new model, termed as the Professional Values Model, developed by the authors was described. Concepts comprising the conceptual framework of the model and relations between the concepts were explained. It is assumed that awareness about concepts of the model will increase not only the patients' satisfaction with nursing care, but also the nurses' job satisfaction and quality of nursing care. Contemporary literature has been reviewed and synthesized to develop this theoretical paper on the Professional Values Model in nursing. Having high values in nursing increases job satisfaction, which results in the improvement of patient care and satisfaction. Also, individual characteristics are effective in the determination of individual needs, priorities, and values. This relation, proved through research about the Professional Values Model, has been explained. With development of these concepts, individuals' satisfaction with care and nurses' job satisfaction will be enhanced, which will increase the quality of nursing care. Most importantly, nurses can take proper decisions about ethical dilemmas and take ethical action when they take these values into consideration when giving care. The Professional Values Model seems suitable for nurse managers and it is expected that testing will improve it. Implementation of the Professional Values Model by nurse managers may increase motivation of nurses they work with. It is suggested that guidance by the Professional Values Model may help in enhancement of motivation efforts of the nurse managers and therefore should be taken into account.

Explanation to the difference in the ketyl radical formation yields of benzophenone and benzil

NASA Astrophysics Data System (ADS)

Okutsu, Tetsuo; Muramatsu, Hidenori; Horiuchi, Hiroaki; Hiratsuka, Hiroshi

2005-03-01

p Ka values of benzophenone ketyl and benzil ketyl radicals were determined as 9.4 and 12.4, respectively. We can successfully explain the difference in quantum yield of the proton transfer between benzophenone ketyl and benzil ketyl radicals by these values. Reaction enthalpies of the proton transfer are the same (-80 kJ mol -1) for these radicals, and the difference in p Ka value can be explained by that reaction entropies. Reaction entropies between two radicals are discussed by the possible structure of the radicals.

Analytical approach to the multi-state lasing phenomenon in quantum dot lasers

NASA Astrophysics Data System (ADS)

Korenev, V. V.; Savelyev, A. V.; Zhukov, A. E.; Omelchenko, A. V.; Maximov, M. V.

2013-03-01

We introduce an analytical approach to describe the multi-state lasing phenomenon in quantum dot lasers. We show that the key parameter is the hole-to-electron capture rate ratio. If it is lower than a certain critical value, the complete quenching of ground-state lasing takes place at high injection levels. At higher values of the ratio, the model predicts saturation of the ground-state power. This explains the diversity of experimental results and their contradiction to the conventional rate equation model. Recently found enhancement of ground-state lasing in p-doped samples and temperature dependence of the ground-state power are also discussed.

Food-related attentional bias. Word versus pictorial stimuli and the importance of stimuli calorific value in the dot probe task.

PubMed

Freijy, Tanya; Mullan, Barbara; Sharpe, Louise

2014-12-01

The primary aim of this study was to extend previous research on food-related attentional biases by examining biases towards pictorial versus word stimuli, and foods of high versus low calorific value. It was expected that participants would demonstrate greater biases to pictures over words, and to high-calorie over low-calorie foods. A secondary aim was to examine associations between BMI, dietary restraint, external eating and attentional biases. It was expected that high scores on these individual difference variables would be associated with a bias towards high-calorie stimuli. Undergraduates (N = 99) completed a dot probe task including matched word and pictorial food stimuli in a controlled setting. Questionnaires assessing eating behaviour were administered, and height and weight were measured. Contrary to predictions, there were no main effects for stimuli type (pictures vs words) or calorific value (high vs low). There was, however, a significant interaction effect suggesting a bias towards high-calorie pictures, but away from high-calorie words; and a bias towards low-calorie words, but away from low-calorie pictures. No associations between attentional bias and any of the individual difference variables were found. The presence of a stimulus type by calorific value interaction demonstrates the importance of stimuli type in the dot probe task, and may help to explain inconsistencies in prior research. Further research is needed to clarify associations between attentional bias and BMI, restraint, and external eating. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mechanisms of Habitual Approach

PubMed Central

Anderson, Brian A.; Folk, Charles L.; Garrison, Rebecca; Rogers, Leeland

2016-01-01

Reward learning has a powerful influence on the attention system, causing previously reward-associated stimuli to automatically capture attention. Difficulty ignoring stimuli associated with drug reward has been linked to addiction relapse, and the attention system of drug-dependent patients seems especially influenced by reward history. This and other evidence suggests that value-driven attention has consequences for behavior and decision-making, facilitating a bias to approach and consume the previously reward-associated stimulus even when doing so runs counter to current goals and priorities. Yet, a mechanism linking value-driven attention to behavioral responding and a general approach bias is lacking. Here we show that previously reward-associated stimuli escape inhibitory processing in a go/no-go task. Control experiments confirmed that this value-dependent failure of goal-directed inhibition could not be explained by search history or residual motivation, but depended specifically on the learned association between particular stimuli and reward outcome. When a previously high-value stimulus is encountered, the response codes generated by that stimulus are automatically afforded high priority, bypassing goal-directed cognitive processes involved in suppressing task-irrelevant behavior. PMID:27054684

Applying the Expectancy-Value Model to understand health values.

PubMed

Zhang, Xu-Hao; Xie, Feng; Wee, Hwee-Lin; Thumboo, Julian; Li, Shu-Chuen

2008-03-01

Expectancy-Value Model (EVM) is the most structured model in psychology to predict attitudes by measuring attitudinal attributes (AAs) and relevant external variables. Because health value could be categorized as attitude, we aimed to apply EVM to explore its usefulness in explaining variances in health values and investigate underlying factors. Focus group discussion was carried out to identify the most common and significant AAs toward 5 different health states (coded as 11111, 11121, 21221, 32323, and 33333 in EuroQol Five-Dimension (EQ-5D) descriptive system). AAs were measured in a sum of multiplications of subjective probability (expectancy) and perceived value of attributes with 7-point Likert scales. Health values were measured using visual analog scales (VAS, range 0-1). External variables (age, sex, ethnicity, education, housing, marital status, and concurrent chronic diseases) were also incorporated into survey questionnaire distributed by convenience sampling among eligible respondents. Univariate analyses were used to identify external variables causing significant differences in VAS. Multiple linear regression model (MLR) and hierarchical regression model were used to investigate the explanatory power of AAs and possible significant external variable(s) separately or in combination, for each individual health state and a mixed scenario of five states, respectively. Four AAs were identified, namely, "worsening your quality of life in terms of health" (WQoL), "adding a burden to your family" (BTF), "making you less independent" (MLI) and "unable to work or study" (UWS). Data were analyzed based on 232 respondents (mean [SD] age: 27.7 [15.07] years, 49.1% female). Health values varied significantly across 5 health states, ranging from 0.12 (33333) to 0.97 (11111). With no significant external variables identified, EVM explained up to 62% of the variances in health values across 5 health states. The explanatory power of 4 AAs were found to be between 13% and 28% in separate MLR models (P < 0.05). When data were analyzed for each health state, variances in health values became small and explanatory power of EVM was reduced to a range between 8% and 23%. EVM was useful in explaining variances of health values and predicting important factors. Its power to explain small variances might be restricted due to limitations of 7-point Likert scale to measure AAs accurately. With further improvement and validation of a compatible continuous scale for more accurate measurement, EVM is expected to explain health values to a larger extent.

Volatile abundances and oxygen isotopes in basaltic to dacitic lavas on mid-ocean ridges: The role of assimilation at spreading centers

USGS Publications Warehouse

Wanless, V.D.; Perfit, M.R.; Ridley, W.I.; Wallace, P.J.; Grimes, Craig B.; Klein, E.M.

2011-01-01

Most geochemical variability in MOR basalts is consistent with low- to moderate-pressure fractional crystallization of various mantle-derived parental melts. However, our geochemical data from MOR high-silica glasses, including new volatile and oxygen isotope data, suggest that assimilation of altered crustal material plays a significant role in the petrogenesis of dacites and may be important in the formation of basaltic lavas at MOR in general. MOR high-silica andesites and dacites from diverse areas show remarkably similar major element trends, incompatible trace element enrichments, and isotopic signatures suggesting similar processes control their chemistry. In particular, very high Cl and elevated H2O concentrations and relatively light oxygen isotope ratios (~ 5.8‰ vs. expected values of ~ 6.8‰) in fresh dacite glasses can be explained by contamination of magmas from a component of ocean crust altered by hydrothermal fluids. Crystallization of silicate phases and Fe-oxides causes an increase in δ18O in residual magma, but assimilation of material initially altered at high temperatures results in lower δ18O values. The observed geochemical signatures can be explained by extreme fractional crystallization of a MOR basalt parent combined with partial melting and assimilation (AFC) of amphibole-bearing altered oceanic crust. The MOR dacitic lavas do not appear to be simply the extrusive equivalent of oceanic plagiogranites. The combination of partial melting and assimilation produces a distinct geochemical signature that includes higher incompatible trace element abundances and distinct trace element ratios relative to those observed in plagiogranites.

Natural and Anthropogenic Factors Controlling the Down Profile Increase in δ13C of Soil Organic Matter

NASA Astrophysics Data System (ADS)

Serach, L.; Breecker, D.

2016-12-01

The increases in the stable C isotope ratio (δ13C) of soil organic carbon (SOC) with depth common in well-drained soils are widely accepted as being due to the C isotope fractionation between CO2 and SOC during microbial respiration. However, results from previous studies that investigate C isotope fractionation during respiration are conflicting. Respired CO2 with 13C values lower, higher and not significantly different than the associated SOC have been reported in the literature. This project aims to quantify the contribution of isotopic fractionation during microbial respiration to the down-profile shift in δ13C values by means of a long-term (2 year) incubation of topsoil (0-2cm). The topsoil used in the incubations was collected from undisturbed temperate and tropical forests. At each location, soil profiles from 0-20 cm depth were also collected and the down profile trends in concentrations and δ13C values of bulk organic carbon were measured. The CO2-SOC carbon isotope enrichment factor ɛCO2-SOM required to explain each profile was then calculated. We compared these calculated ɛCO2-SOM values with empirical values determined from soil incubations. ɛCO2-SOM values were determined from incubations as the difference between δ13C values of headspace CO2 and bulk SOC. We have thus far measured these δ13C values at 1,4 and 7 months, allowing us to track if and when empirical ɛCO2-SOM values reach the magnitude required to explain the profiles. Thus far, all empirical ɛCO2-SOM values are either too small or of the wrong sign to explain the profiles, suggesting that a mechanism other than C isotope fractionation during microbial respiration may be responsible. Therefore, we are also investigating the possibility that the anthropogenic increase in concentrations of atmospheric CO2, through its influence on δ13C values of C3 plants, explains a substantial portion of the typical down profile increase in SOC δ13C values.

Self-Interacting Dark Matter Can Explain Diverse Galactic Rotation Curves

NASA Astrophysics Data System (ADS)

Kamada, Ayuki; Kaplinghat, Manoj; Pace, Andrew B.; Yu, Hai-Bo

2017-09-01

The rotation curves of spiral galaxies exhibit a diversity that has been difficult to understand in the cold dark matter (CDM) paradigm. We show that the self-interacting dark matter (SIDM) model provides excellent fits to the rotation curves of a sample of galaxies with asymptotic velocities in the 25 - 300 km /s range that exemplify the full range of diversity. We assume only the halo concentration-mass relation predicted by the CDM model and a fixed value of the self-interaction cross section. In dark-matter-dominated galaxies, thermalization due to self-interactions creates large cores and reduces dark matter densities. In contrast, thermalization leads to denser and smaller cores in more luminous galaxies and naturally explains the flatness of rotation curves of the highly luminous galaxies at small radii. Our results demonstrate that the impact of the baryons on the SIDM halo profile and the scatter from the assembly history of halos as encoded in the concentration-mass relation can explain the diverse rotation curves of spiral galaxies.

Self-Interacting Dark Matter Can Explain Diverse Galactic Rotation Curves.

PubMed

Kamada, Ayuki; Kaplinghat, Manoj; Pace, Andrew B; Yu, Hai-Bo

2017-09-15

The rotation curves of spiral galaxies exhibit a diversity that has been difficult to understand in the cold dark matter (CDM) paradigm. We show that the self-interacting dark matter (SIDM) model provides excellent fits to the rotation curves of a sample of galaxies with asymptotic velocities in the 25-300  km/s range that exemplify the full range of diversity. We assume only the halo concentration-mass relation predicted by the CDM model and a fixed value of the self-interaction cross section. In dark-matter-dominated galaxies, thermalization due to self-interactions creates large cores and reduces dark matter densities. In contrast, thermalization leads to denser and smaller cores in more luminous galaxies and naturally explains the flatness of rotation curves of the highly luminous galaxies at small radii. Our results demonstrate that the impact of the baryons on the SIDM halo profile and the scatter from the assembly history of halos as encoded in the concentration-mass relation can explain the diverse rotation curves of spiral galaxies.

Growth and characterization of high current density, high-speed InAs/AlSb resonant tunneling diodes

NASA Technical Reports Server (NTRS)

Soderstrom, J. R.; Brown, E. R.; Parker, C. D.; Mahoney, L. J.; Yao, J. Y.

1991-01-01

InAs/AlSb double-barrier resonant tunneling diodes with peak current densities up to 370,000 A/sq cm and high peak-to-valley current ratios of 3.2 at room temperature have been fabricated. The peak current density is well-explained by a stationary-state transport model with the two-band envelope function approximation. The valley current density predicted by this model is less than the experimental value by a factor that is typical of the discrepancy found in other double-barrier structures. It is concluded that threading dislocations are largely inactive in the resonant tunneling process.

A geographical approach to tracking Escherichia coli and other water quality constituents in a Texas coastal plains watershed.

PubMed

Harclerode, C L; Gentry, T J; Aitkenhead-Peterson, J A

2013-06-01

Diffuse sources of surface water pathogens and nutrients can be difficult to isolate in larger river basins. This study used a geographical or nested approach to isolate diffuse sources of Escherichia coli and other water quality constituents in a 145.7-km(2) river basin in south central Texas, USA. Average numbers of E. coli ranged from 49 to 64,000 colony forming units (CFU) per 100 mL depending upon season and stream flow over the 1-year sampling period. Nitrate-N concentrations ranged from 48 to 14,041 μg L(-1) and orthophosphate-P from 27 to 2,721 μg L(-1). High concentrations of nitrate-N, dissolved organic nitrogen, and orthophosphate-P were observed downstream of waste water treatment plants but E. coli values were higher in a watershed draining an older part of the city. Total urban land use explained between 56 and 72 % of the variance in mean annual E. coli values (p < 0.05) in nine hydrologically disconnected creeks. Of the types of urban land use, commercial land use explained most of the variance in E. coli values in the fall and winter. Surface water sodium, alkalinity, and potassium concentrations in surface water were best described by the proportion of commercial land use in the watershed. Based on our nested approach in examining surface water, city officials are able to direct funding to specific areas of the basin in order to mitigate high surface water E. coli numbers and nutrient concentrations.

Validity of the Néel-Arrhenius model for highly anisotropic Co{sub x}Fe{sub 3−x}O{sub 4} nanoparticles

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

Torres, T. E.; Ibarra, M. R.; Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad de Zaragoza, 50009 Zaragoza

2015-11-14

We report a systematic study on the structural and magnetic properties of Co{sub x}Fe{sub 3−x}O{sub 4} magnetic nanoparticles with sizes between 5 and 25 nm, prepared by thermal decomposition of Fe(acac){sub 3} and Co(acac){sub 2}. The large magneto-crystalline anisotropy of the synthesized particles resulted in high blocking temperatures (42 K < T{sub B} < 345 K for 5 < d < 13 nm) and large coercive fields (H{sub C} ≈ 1600 kA/m for T = 5 K). The smallest particles (〈d〉=5 nm) revealed the existence of a magnetically hard, spin-disordered surface. The thermal dependence of static and dynamic magnetic properties of the whole series of samples could be explained within the Neel–Arrhenius relaxation framework by including the thermal dependencemore » of the magnetocrystalline anisotropy constant K{sub 1}(T), without the need of ad-hoc corrections. This approach, using the empirical Brükhatov-Kirensky relation, provided K{sub 1}(0) values very similar to the bulk material from either static or dynamic magnetic measurements, as well as realistic values for the response times (τ{sub 0} ≈ 10{sup −10}s). Deviations from the bulk anisotropy values found for the smallest particles could be qualitatively explained based on Zener's relation between K{sub 1}(T) and M(T)« less

Combined multifrequency EPR and DFT study of dangling bonds in a-Si:H

NASA Astrophysics Data System (ADS)

Fehr, M.; Schnegg, A.; Rech, B.; Lips, K.; Astakhov, O.; Finger, F.; Pfanner, G.; Freysoldt, C.; Neugebauer, J.; Bittl, R.; Teutloff, C.

2011-12-01

Multifrequency pulsed electron paramagnetic resonance (EPR) spectroscopy using S-, X-, Q-, and W-band frequencies (3.6, 9.7, 34, and 94 GHz, respectively) was employed to study paramagnetic coordination defects in undoped hydrogenated amorphous silicon (a-Si:H). The improved spectral resolution at high magnetic field reveals a rhombic splitting of the g tensor with the following principal values: gx=2.0079, gy=2.0061, and gz=2.0034, and shows pronounced g strain, i.e., the principal values are widely distributed. The multifrequency approach furthermore yields precise 29Si hyperfine data. Density functional theory (DFT) calculations on 26 computer-generated a-Si:H dangling-bond models yielded g values close to the experimental data but deviating hyperfine interaction values. We show that paramagnetic coordination defects in a-Si:H are more delocalized than computer-generated dangling-bond defects and discuss models to explain this discrepancy.

Incorporation of the Time-Varying Postprandial Increase in Splanchnic Blood Flow into a PBPK Model to Predict the Effect of Food on the Pharmacokinetics of Orally Administered High-Extraction Drugs.

PubMed

Rose, Rachel H; Turner, David B; Neuhoff, Sibylle; Jamei, Masoud

2017-07-01

Following a meal, a transient increase in splanchnic blood flow occurs that can result in increased exposure to orally administered high-extraction drugs. Typically, physiologically based pharmacokinetic (PBPK) models have incorporated this increase in blood flow as a time-invariant fed/fasted ratio, but this approach is unable to explain the extent of increased drug exposure. A model for the time-varying increase in splanchnic blood flow following a moderate- to high-calorie meal (TV-Q Splanch ) was developed to describe the observed data for healthy individuals. This was integrated within a PBPK model and used to predict the contribution of increased splanchnic blood flow to the observed food effect for two orally administered high-extraction drugs, propranolol and ibrutinib. The model predicted geometric mean fed/fasted AUC and C max ratios of 1.24 and 1.29 for propranolol, which were within the range of published values (within 1.0-1.8-fold of values from eight clinical studies). For ibrutinib, the predicted geometric mean fed/fasted AUC and C max ratios were 2.0 and 1.84, respectively, which was within 1.1-fold of the reported fed/fasted AUC ratio but underestimated the reported C max ratio by up to 1.9-fold. For both drugs, the interindividual variability in fed/fasted AUC and C max ratios was underpredicted. This suggests that the postprandial change in splanchnic blood flow is a major mechanism of the food effect for propranolol and ibrutinib but is insufficient to fully explain the observations. The proposed model is anticipated to improve the prediction of food effect for high-extraction drugs, but should be considered with other mechanisms.

Chlorine isotopic compositions of apatite in Apollo 14 rocks: Evidence for widespread vapor-phase metasomatism on the lunar nearside ∼4 billion years ago

NASA Astrophysics Data System (ADS)

Potts, Nicola J.; Barnes, Jessica J.; Tartèse, Romain; Franchi, Ian A.; Anand, Mahesh

2018-06-01

Compared to most other planetary materials in the Solar System, some lunar rocks display high δ37Cl signatures. Loss of Cl in a H ≪ Cl environment has been invoked to explain the heavy signatures observed in lunar samples, either during volcanic eruptions onto the lunar surface or during large scale degassing of the lunar magma ocean. To explore the conditions under which Cl isotope fractionation occurred in lunar basaltic melts, five Apollo 14 crystalline samples were selected (14053,19, 14072,13, 14073,9, 14310,171 along with basaltic clast 14321,1482) for in situ analysis of Cl isotopes using secondary ion mass spectrometry. Cl isotopes were measured within the mineral apatite, with δ37Cl values ranging from +14.6 ± 1.6‰ to +40.0 ± 2.9‰. These values expand the range previously reported for apatite in lunar rocks, and include some of the heaviest Cl isotope compositions measured in lunar samples to date. The data here do not display a trend between increasing rare earth elements contents and δ37Cl values, reported in previous studies. Other processes that can explain the wide inter- and intra-sample variability of δ37Cl values are explored. Magmatic degassing is suggested to have potentially played a role in fractionating Cl isotope in these samples. Degassing alone, however, could not create the wide variability in isotopic signatures. Our favored hypothesis, to explain small scale heterogeneity, is late-stage interaction with a volatile-rich gas phase, originating from devolatilization of lunar surface regolith rocks ∼4 billion years ago. This period coincides with vapor-induced metasomastism recorded in other lunar samples collected at the Apollo 16 and 17 landing sites, pointing to the possibility of widespread volatile-induced metasomatism on the lunar nearside at that time, potentially attributed to the Imbrium formation event.

Kinetics of acyl transfer reactions in organic media catalysed by Candida antarctica lipase B.

PubMed

Martinelle, M; Hult, K

1995-09-06

The acyl transfer reactions catalysed by Candida antartica lipase B in organic media followed a bi-bi ping-pong mechanism, with competitive substrate inhibition by the alcohols used as acyl acceptors. The effect of organic solvents on Vm and Km was investigated. The Vm values in acetonitrile was 40-50% of those in heptane. High Km values in acetonitrile compared to those in heptane could partly be explained by an increased solvation of the substrates in acetonitrile. Substrate solvation caused a 10-fold change in substrate specificity, defined as (Vm/Km)ethyl octanoate/(Vm/Km)octanoic acid, going from heptane to acetonitrile. Deacylation was the rate determining step for the acyl transfer in heptane with vinyl- and ethyl octanoate as acyl donors and (R)-2-octanol as acyl acceptor. With 1-octanol, a rate determining deacylation step in heptane was indicated using the same acyl donors. Using 1-octanol as acceptor in heptane, S-ethyl thiooctanoate had a 25- to 30-fold lower Vm/Km value and vinyl octanoate a 4-fold higher Vm/Km value than that for ethyl octanoate. The difference showed to be a Km effect for vinyl octanoate and mainly a Km effect for S-ethyl thiooctanoate. The Vm values of the esterification of octanoic acid with different alcohols was 10-30-times lower than those for the corresponding transesterification of ethyl octanoate. The low activity could be explained by a low pH around the enzyme caused by the acid or a withdrawing of active enzyme by nonproductive binding by the acid.

Values in science and risk assessment.

PubMed

Wandall, Birgitte

2004-09-25

It is a widely accepted claim that scientific practice contains value judgments, i.e. decisions made on the basis of values. This paper clarifies the concepts involved in this claim and explains its implications for risk assessment. It is explained why values are necessarily a part of science and of risk assessment. A certain type of values that contribute to the aim of science, so-called epistemic values, are identified as rationally justified as basis for judgment in science. It is argued that the aims of pure science and risk assessment differ in some aspects and that consequently pure science's epistemic values are not sufficient for risk assessment. I suggest how the epistemic values may be supplemented in order to align better with the aim of risk assessment. It is concluded that since risk assessment is no less value-laden than pure science, it is important (a) that risk assessors become aware of what values they are (often implicitly) relying on, (b) that the values are justifiable, and (c) that transparency is ensured, i.e. that the values and value-based assumptions applied in particular risk assessments are explicitly acknowledged.

Risk Aversion and the Value of Information.

ERIC Educational Resources Information Center

Eeckhoudt, Louis; Godfroid, Phillippe

2000-01-01

Explains why risk aversion does not always induce a greater information value, but instead may induce a lower information value when increased. Presents a basic model defining the concept of perfect information value and providing a numerical illustration. Includes references. (CMK)

Correction to Kreuzbauer, King, and Basu (2015).

PubMed

2015-08-01

Reports an error in "The Mind in the Object-Psychological Valuation of Materialized Human Expression" by Robert Kreuzbauer, Dan King and Shankha Basu (Journal of Experimental Psychology: General, Advanced Online Publication, Jun 15, 2015, np). In the article the labels on the X-axis of Figure 1 "Remove Variance" and "Preserve Variance" should be switched. (The following abstract of the original article appeared in record 2015-26264-001.) Symbolic material objects such as art or certain artifacts (e.g., fine pottery, jewelry) share one common element: The combination of generating an expression, and the materialization of this expression in the object. This explains why people place a much greater value on handmade over machine-made objects, and originals over duplicates. We show that this mechanism occurs when a material object's symbolic property is salient and when the creator (artist or craftsman) is perceived to have agency control over the 1-to-1 materialized expression in the object. Coactivation of these 2 factors causes the object to be perceived as having high value because it is seen as the embodied representation of the creator's unique personal expression. In 6 experiments, subjects rated objects in various object categories, which varied on the type of object property (symbolic, functional, aesthetic), the production procedure (handmade, machine-made, analog, digital) and the origin of the symbolic information (person or software). The studies showed that the proposed mechanism applies to symbolic, but not to functional or aesthetic material objects. Furthermore, they show that this specific form of symbolic object valuation could not be explained by various other related psychological theories (e.g., uniqueness, scarcity, physical touching, creative performance). Our research provides a universal framework that identifies a core mechanism for explaining judgments of value for one of our most uniquely human symbolic object categories. (c) 2015 APA, all rights reserved).

The mind in the object-Psychological valuation of materialized human expression.

PubMed

Kreuzbauer, Robert; King, Dan; Basu, Shankha

2015-08-01

[Correction Notice: An Erratum for this article was reported in Vol 144(4) of Journal of Experimental Psychology: General (see record 2015-33206-002). In the article the labels on the X-axis of Figure 1 "Remove Variance" and "Preserve Variance" should be switched.] Symbolic material objects such as art or certain artifacts (e.g., fine pottery, jewelry) share one common element: The combination of generating an expression, and the materialization of this expression in the object. This explains why people place a much greater value on handmade over machine-made objects, and originals over duplicates. We show that this mechanism occurs when a material object's symbolic property is salient and when the creator (artist or craftsman) is perceived to have agency control over the 1-to-1 materialized expression in the object. Coactivation of these 2 factors causes the object to be perceived as having high value because it is seen as the embodied representation of the creator's unique personal expression. In 6 experiments, subjects rated objects in various object categories, which varied on the type of object property (symbolic, functional, aesthetic), the production procedure (handmade, machine-made, analog, digital) and the origin of the symbolic information (person or software). The studies showed that the proposed mechanism applies to symbolic, but not to functional or aesthetic material objects. Furthermore, they show that this specific form of symbolic object valuation could not be explained by various other related psychological theories (e.g., uniqueness, scarcity, physical touching, creative performance). Our research provides a universal framework that identifies a core mechanism for explaining judgments of value for one of our most uniquely human symbolic object categories. (c) 2015 APA, all rights reserved).

A dynamic processes study of PM retention by trees under different wind conditions.

PubMed

Xie, Changkun; Kan, Liyan; Guo, Jiankang; Jin, Sijia; Li, Zhigang; Chen, Dan; Li, Xin; Che, Shengquan

2018-02-01

Particulate matter (PM) is one of the most serious environmental problems, exacerbating respiratory and vascular illnesses. Plants have the ability to reduce non-point source PM pollution through retention on leaves and branches. Studies of the dynamic processes of PM retention by plants and the mechanisms influencing this process will help to improve the efficiency of urban greening for PM reduction. We examined dynamic processes of PM retention and the major factors influencing PM retention by six trees with different branch structure characteristics in wind tunnel experiments at three different wind speeds. The results showed that the changes of PM numbers retained by plant leaves over time were complex dynamic processes for which maximum values could exceed minimum values by over 10 times. The average value of PM measured in multiple periods and situations can be considered a reliable indicator of the ability of the plant to retain PM. The dynamic processes were similar for PM 10 and PM 2.5 . They could be clustered into three groups simulated by continually-rising, inverse U-shaped, and U-shaped polynomial functions, respectively. The processes were the synthetic effect of characteristics such as species, wind speed, period of exposure and their interactions. Continually-rising functions always explained PM retention in species with extremely complex branch structure. Inverse U-shaped processes explained PM retention in species with relatively simple branch structure and gentle wind. The U-shaped processes mainly explained PM retention at high wind speeds and in species with a relatively simple crown. These results indicate that using plants with complex crowns in urban greening and decreasing wind speed in plant communities increases the chance of continually-rising or inverse U-shaped relationships, which have a positive effect in reducing PM pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of slip-area scaling on the earthquake frequency-magnitude relationship

NASA Astrophysics Data System (ADS)

Senatorski, Piotr

2017-06-01

The earthquake frequency-magnitude relationship is considered in the maximum entropy principle (MEP) perspective. The MEP suggests sampling with constraints as a simple stochastic model of seismicity. The model is based on the von Neumann's acceptance-rejection method, with b-value as the parameter that breaks symmetry between small and large earthquakes. The Gutenberg-Richter law's b-value forms a link between earthquake statistics and physics. Dependence between b-value and the rupture area vs. slip scaling exponent is derived. The relationship enables us to explain observed ranges of b-values for different types of earthquakes. Specifically, different b-value ranges for tectonic and induced, hydraulic fracturing seismicity is explained in terms of their different triggering mechanisms: by the applied stress increase and fault strength reduction, respectively.

Where do Property Rights Matter More? Explaining the Variation in Demand for Property Titles across Cities in Mexico

PubMed Central

Monkkonen, Paavo

2016-01-01

Summary This paper examines the variation in the value of property rights to housing in Mexico, focusing specifically on differences between urban housing markets. Roughly 30% of owner-occupied houses in Mexico do not have a proper deed. Houses with no deed are estimated to be five percent less valuable than otherwise similar houses with a full deed, yet this premium varies widely across cities. I match data from the 2012 and 2014 National Survey of Household Incomes and Expenditures to different sources of city-level data in order to examine hypotheses explaining this variation in a multilevel regression framework. I find that deeds are valued more in cities with more highly educated residents, more political competition, and more voting. Measures of local economic activity, degree of informality, and the regulatory bureaucracy are not associated with higher value to full property rights. Additionally, I find that more educated households value deeds more, and having a deed is more valuable for larger houses in neighborhoods with less vacancy and higher infrastructure quality. Based on these results, I suggest funds to subsidize titling should be redirected to places where titles are worth more. More broadly, I suggest policymakers reconsider framing property-titling programs as poverty alleviation. Low-income households would benefit more from subsidies for improvements to housing and residential infrastructure. At the same time, the federal government should further push to reduce the costs of transferring property. PMID:27616806

Study of electrical conductivity and memory switching in the zinc-vanadium-phosphate glasses

NASA Astrophysics Data System (ADS)

Mirzayi, M.; Hekmatshoar, M. H.

2013-07-01

Vanadium zinc phosphate glasses were prepared by the conventional melt quenching technique and effect of V2O5 concentration on d.c. conductivity of prepared samples were investigated. X-ray diffraction patterns confirmed the glassy character of the samples. The d.c. conductivity increased with increase in V2O5 content. Results showed that activation energy has a single value in the investigated range of temperature, which can be explained in accordance with Mott small pollaron hopping model. I-V characteristics at high electric field showed that switching in these glasses was memory type. The threshold field of switching was found to decrease with increase in V2O5 content. Non-linear behavior and switching phenomenon was explained by Pool-Frenkel effect and thermal model.

LUR models for particulate matters in the Taipei metropolis with high densities of roads and strong activities of industry, commerce and construction.

PubMed

Lee, Jui-Huna; Wu, Chang-Fu; Hoek, Gerard; de Hoogh, Kees; Beelen, Rob; Brunekreef, Bert; Chan, Chang-Chuan

2015-05-01

Traffic intensity, length of road, and proximity to roads are the most common traffic indicators in the land use regression (LUR) models for particulate matter in ESCAPE study areas in Europe. This study explored what local variables can improve the performance of LUR models in an Asian metropolis with high densities of roads and strong activities of industry, commerce and construction. By following the ESCAPE procedure, we derived LUR models of PM₂.₅, PM₂.₅ absorbance, PM₁₀, and PMcoarse (PM₂.₅-₁₀) in Taipei. The overall annual average concentrations of PM₂.₅, PM₁₀, and PMcoarse were 26.0 ± 5.6, 48.6 ± 5.9, and 23.3 ± 3.1 μg/m(3), respectively, and the absorption coefficient of PM₂.₅ was 2.0 ± 0.4 × 10(-5)m(-1). Our LUR models yielded R(2) values of 95%, 96%, 87%, and 65% for PM₂.₅, PM₂.₅ absorbance, PM₁₀, and PMcoarse, respectively. PM₂.₅ levels were increased by local traffic variables, industrial, construction, and residential land-use variables and decreased by rivers; while PM₂.₅ absorbance levels were increased by local traffic variables, industrial, and commercial land-use variables in the models. PMcoarse levels were increased by elevated highways. Road area explained more variance than road length by increasing the incremental value of 27% and 6% adjusted R(2) for PM₂.₅ and PM₁₀ models, respectively. In the PM₂.₅ absorbance model, road area and transportation facility explain 29% more variance than road length. In the PMcoarse model, industrial and new local variables instead of road length improved the incremental value of adjusted R(2) from 39% to 60%. We concluded that road area can better explain the spatial distribution of PM₂.₅ and PM₂.₅ absorbance concentrations than road length. By incorporating road area and other new local variables, the performance of each PM LUR model was improved. The results suggest that road area is a better indicator of traffic intensity rather than road length in a city with high density of road network and traffic. Copyright © 2015 Elsevier B.V. All rights reserved.

SU-F-BRD-16: Relative Biological Effectiveness of Double-Strand Break Induction for Modeling Cell Survival in Pristine Proton Beams of Different Dose-Averaged Linear Energy Transfers

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

Peeler, C; Bronk, L; UT Graduate School of Biomedical Sciences at Houston, Houston, TX

2015-06-15

Purpose: High throughput in vitro experiments assessing cell survival following proton radiation indicate that both the alpha and the beta parameters of the linear quadratic model increase with increasing proton linear energy transfer (LET). We investigated the relative biological effectiveness (RBE) of double-strand break (DSB) induction as a means of explaining the experimental results. Methods: Experiments were performed with two lung cancer cell lines and a range of proton LET values (0.94 – 19.4 keV/µm) using an experimental apparatus designed to irradiate cells in a 96 well plate such that each column encounters protons of different dose-averaged LET (LETd). Traditionalmore » linear quadratic survival curve fitting was performed, and alpha, beta, and RBE values obtained. Survival curves were also fit with a model incorporating RBE of DSB induction as the sole fit parameter. Fitted values of the RBE of DSB induction were then compared to values obtained using Monte Carlo Damage Simulation (MCDS) software and energy spectra calculated with Geant4. Other parameters including alpha, beta, and number of DSBs were compared to those obtained from traditional fitting. Results: Survival curve fitting with RBE of DSB induction yielded alpha and beta parameters that increase with proton LETd, which follows from the standard method of fitting; however, relying on a single fit parameter provided more consistent trends. The fitted values of RBE of DSB induction increased beyond what is predicted from MCDS data above proton LETd of approximately 10 keV/µm. Conclusion: In order to accurately model in vitro proton irradiation experiments performed with high throughput methods, the RBE of DSB induction must increase more rapidly than predicted by MCDS above LETd of 10 keV/µm. This can be explained by considering the increased complexity of DSBs or the nature of intra-track pairwise DSB interactions in this range of LETd values. NIH Grant 2U19CA021239-35.« less

Magnetic phase separation and strong enhancement of the Néel temperature at high pressures in a new multiferroic Ba3TaFe3Si2O14

NASA Astrophysics Data System (ADS)

Lyubutin, I. S.; Starchikov, S. S.; Gavriliuk, A. G.; Troyan, I. A.; Nikiforova, Yu. A.; Ivanova, A. G.; Chumakov, A. I.; Rüffer, R.

2017-01-01

The high-pressure properties of a new multiferroic of the langasite family Ba3TaFe3Si2O14 were investigated in diamond-anvil cells (DAC) in the temperature range of 4.2-295 K by a new method of synchrotron Mössbauer spectroscopy. Strong enhancement of the Néel temperature T N was observed at pressures above 20 GPa associated with the structural transformation. The highest value of T N is about 130 K which is almost five times larger than the value at ambient pressure (about 27 K). It was suggested that the high value of T N appears due to redistribution of Fe ions over 3 f and 2 d tetrahedral sites of the langasite structure. In this case, the short Fe-O distances and favorable Fe-O-Fe bond angles create conditions for strong superexchange interactions between iron ions, and effective two-dimensional (2D) magnetic ordering appears in the ( ab) plane. The separation of the sample into two magnetic phases with different T N values of about 50 and 130 K was revealed, which can be explained by the strong 2D magnetic ordering in the ab plane and 3D ordering involving inter-plane interaction.

Energy-dependent path of dissipation in nanomechanical resonators.

PubMed

Güttinger, Johannes; Noury, Adrien; Weber, Peter; Eriksson, Axel Martin; Lagoin, Camille; Moser, Joel; Eichler, Christopher; Wallraff, Andreas; Isacsson, Andreas; Bachtold, Adrian

2017-07-01

Energy decay plays a central role in a wide range of phenomena, such as optical emission, nuclear fission, and dissipation in quantum systems. Energy decay is usually described as a system leaking energy irreversibly into an environmental bath. Here, we report on energy decay measurements in nanomechanical systems based on multilayer graphene that cannot be explained by the paradigm of a system directly coupled to a bath. As the energy of a vibrational mode freely decays, the rate of energy decay changes abruptly to a lower value. This finding can be explained by a model where the measured mode hybridizes with other modes of the resonator at high energy. Below a threshold energy, modes are decoupled, resulting in comparatively low decay rates and giant quality factors exceeding 1 million. Our work opens up new possibilities to manipulate vibrational states, engineer hybrid states with mechanical modes at completely different frequencies, and to study the collective motion of this highly tunable system.

Transport of ice into the stratosphere and the humidification of the stratosphere over the 21st century.

PubMed

Dessler, A E; Ye, H; Wang, T; Schoeberl, M R; Oman, L D; Douglass, A R; Butler, A H; Rosenlof, K H; Davis, S M; Portmann, R W

2016-03-16

Climate models predict that tropical lower-stratospheric humidity will increase as the climate warms. We examine this trend in two state-of-the-art chemistry-climate models. Under high greenhouse gas emissions scenarios, the stratospheric entry value of water vapor increases by ~1 part per million by volume (ppmv) over this century in both models. We show with trajectory runs driven by model meteorological fields that the warming tropical tropopause layer (TTL) explains 50-80% of this increase. The remainder is a consequence of trends in evaporation of ice convectively lofted into the TTL and lower stratosphere. Our results further show that, within the models we examined, ice lofting is primarily important on long time scales - on interannual time scales, TTL temperature variations explain most of the variations in lower stratospheric humidity. Assessing the ability of models to realistically represent ice-lofting processes should be a high priority in the modeling community.

Transport of ice into the stratosphere and the humidification of the stratosphere over the 21st century

PubMed Central

Dessler, A.E.; Ye, H.; Wang, T.; Schoeberl, M.R.; Oman, L.D.; Douglass, A.R.; Butler, A.H.; Rosenlof, K.H.; Davis, S.M.; Portmann, R.W.

2018-01-01

Climate models predict that tropical lower-stratospheric humidity will increase as the climate warms. We examine this trend in two state-of-the-art chemistry-climate models. Under high greenhouse gas emissions scenarios, the stratospheric entry value of water vapor increases by ~1 part per million by volume (ppmv) over this century in both models. We show with trajectory runs driven by model meteorological fields that the warming tropical tropopause layer (TTL) explains 50–80% of this increase. The remainder is a consequence of trends in evaporation of ice convectively lofted into the TTL and lower stratosphere. Our results further show that, within the models we examined, ice lofting is primarily important on long time scales — on interannual time scales, TTL temperature variations explain most of the variations in lower stratospheric humidity. Assessing the ability of models to realistically represent ice-lofting processes should be a high priority in the modeling community. PMID:29551841

Transport of Ice into the Stratosphere and the Humidification of the Stratosphere over the 21st Century

NASA Technical Reports Server (NTRS)

Dessler, A. E.; Ye, H.; Wang, T.; Schoeberl, M. R.; Oman, L. D.; Douglass, A. R.; Butler, A. H.; Rosenlof, K. H.; Davis, S. M.; Portmann, R. W.

2016-01-01

Climate models predict that tropical lower-stratospheric humidity will increase as the climate warms. We examine this trend in two state-of-the-art chemistry-climate models. Under high greenhouse gas emissions scenarios, the stratospheric entry value of water vapor increases by approx. 1 part per million by volume (ppmv) over this century in both models. We show with trajectory runs driven by model meteorological fields that the warming tropical tropopause layer (TTL) explains 50-80% of this increase. The remainder is a consequence of trends in evaporation of ice convectively lofted into the TTL and lower stratosphere. Our results further show that, within the models we examined, ice lofting is primarily important on long time scales - on interannual time scales, TTL temperature variations explain most of the variations in lower stratospheric humidity. Assessing the ability of models to realistically represent ice-lofting processes should be a high priority in the modeling community.

High breakdown electric field in β-Ga2O3/graphene vertical barristor heterostructure

NASA Astrophysics Data System (ADS)

Yan, Xiaodong; Esqueda, Ivan S.; Ma, Jiahui; Tice, Jesse; Wang, Han

2018-01-01

In this work, we study the high critical breakdown field in β-Ga2O3 perpendicular to its (100) crystal plane using a β-Ga2O3/graphene vertical heterostructure. Measurements indicate a record breakdown field of 5.2 MV/cm perpendicular to the (100) plane that is significantly larger than the previously reported values on lateral β-Ga2O3 field-effect-transistors (FETs). This result is compared with the critical field typically measured within the (100) crystal plane, and the observed anisotropy is explained through a combined theoretical and experimental analysis.

Theory of High-T{sub c} Superconducting Cuprates Based on Experimental Evidence

DOE R&D Accomplishments Database

Abrikosov, A. A.

1999-12-10

A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of T{sub c}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.

High-pressure insulator-to-metal transition in Sr3Ir2O7 studied by x-ray absorption spectroscopy

NASA Astrophysics Data System (ADS)

Donnerer, C.; Sala, M. Moretti; Pascarelli, S.; Rosa, A. D.; Andreev, S. N.; Mazurenko, V. V.; Irifune, T.; Hunter, E. C.; Perry, R. S.; McMorrow, D. F.

2018-01-01

High-pressure x-ray absorption spectroscopy was performed at the Ir L3 and L2 absorption edges of Sr3Ir2O7 . The branching ratio of white-line intensities continuously decreases with pressure, reflecting a reduction in the angular part of the expectation value of the spin-orbit coupling operator, 〈L .S 〉 . Up to the high-pressure structural transition at 53 GPa, this behavior can be explained within a single-ion model, where pressure increases the strength of the cubic crystal field, which suppresses the spin-orbit induced hybridization of Jeff=3 /2 and eg levels. We observe a further reduction of the branching ratio above the structural transition, which cannot be explained within a single-ion model of spin-orbit coupling and cubic crystal fields. This change in 〈L .S 〉 in the high-pressure, metallic phase of Sr3Ir2O7 could arise from noncubic crystal fields or a bandwidth-driven hybridization of Jeff=1 /2 ,3 /2 states and suggests that the electronic ground state significantly deviates from the Jeff=1 /2 limit.

A Little Knowledge of Ground Motion: Explaining 3-D Physics-Based Modeling to Engineers

NASA Astrophysics Data System (ADS)

Porter, K.

2014-12-01

Users of earthquake planning scenarios require the ground-motion map to be credible enough to justify costly planning efforts, but not all ground-motion maps are right for all uses. There are two common ways to create a map of ground motion for a hypothetical earthquake. One approach is to map the median shaking estimated by empirical attenuation relationships. The other uses 3-D physics-based modeling, in which one analyzes a mathematical model of the earth's crust near the fault rupture and calculates the generation and propagation of seismic waves from source to ground surface by first principles. The two approaches produce different-looking maps. The more-familiar median maps smooth out variability and correlation. Using them in a planning scenario can lead to a systematic underestimation of damage and loss, and could leave a community underprepared for realistic shaking. The 3-D maps show variability, including some very high values that can disconcert non-scientists. So when the USGS Science Application for Risk Reduction's (SAFRR) Haywired scenario project selected 3-D maps, it was necessary to explain to scenario users—especially engineers who often use median maps—the differences, advantages, and disadvantages of the two approaches. We used authority, empirical evidence, and theory to support our choice. We prefaced our explanation with SAFRR's policy of using the best available earth science, and cited the credentials of the maps' developers and the reputation of the journal in which they published the maps. We cited recorded examples from past earthquakes of extreme ground motions that are like those in the scenario map. We explained the maps on theoretical grounds as well, explaining well established causes of variability: directivity, basin effects, and source parameters. The largest mapped motions relate to potentially unfamiliar extreme-value theory, so we used analogies to human longevity and the average age of the oldest person in samples of varying sizes to illustrate extreme values to non-scientists. We explained the importance of nonlinearity in the relationship between shaking and loss. This was the second time SAFRR encountered skeptics of 3-D maps among scenario consumers, so a short manuscript was prepared that would serve similar uses in the future.

Altitude-dependent changes of directional hearing in mountaineers.

PubMed Central

Rosenberg, M E; Pollard, A J

1992-01-01

This study demonstrates apparent deterioration in the ability to localize sound associated with acute exposure to high altitude in ten subjects on three mountaineering expeditions. Furthermore, the auditory localization errors improved to sea level values after a period of acclimatization. Occurring at altitudes where overt neurological symptoms are not usually seen, impairment of sensory perception may explain the increase in accidental deaths associated with altitude exposure due to disorientation and misjudgment but before hypoxia is evident. PMID:1422652

Preschool Education, Educational Attainment, and Crime Prevention: Contributions of Cognitive and Non-Cognitive Skills

PubMed Central

Reynolds, Arthur J.; Temple, Judy A.; Ou, Suh-Ruu

2016-01-01

We investigated the extent to which cognitive and noncognitive skills accounted for the measured links between participation in preschool intervention and high school completion, highest grade completed, and incarceration history in early adulthood. Using data from the Chicago Longitudinal Study, an on-going 20-year investigation of the effects of the school-based Child-Parent Center early intervention program for over 1,500 children, we assessed the contribution of school readiness and achievement test scores up to age 14 and remedial education as well as measures of social adjustment, motivation, educational expectations, problem behavior, and juvenile arrest to the estimated direct effect of preschool. Hierarchical regression analysis indicated that when assessed separately, cognitive factors accounted for 42% of the preschool effect on high school completion, 37% on highest grade completed, and 23% on incarceration history by age 24 while noncognitive factors accounted for, respectively, 36%, 45%, and 59%. Together, cognitive and noncognitive factors explained 46%, 51%, and 59% of the main effect of preschool participation. The set of cognitive skills made greater value-added contributions to educational attainment while noncognitive skills made greater value-added contributions to incarceration history. Our findings support the important role of test scores, school performance, and social and motivational factors in explaining the effect of preschool participation on economically important indicators of well-being. PMID:27667885

Emotional state and psychological flexibility in breast cancer survivors.

PubMed

González-Fernández, Sonia; Fernández-Rodríguez, Concepción; Mota-Alonso, María Jesús; García-Teijido, Paula; Pedrosa, Ignacio; Pérez-Álvarez, Marino

2017-10-01

This study analyses the premise that less time spent carrying out valuable activities and inflexible avoidance of thoughts, feelings and memories related to the oncological process may play an important role in the emotional problems of cancer survivors. Emotional state was evaluated, as was quality of life and psychological flexibility in a sample of 122 breast cancer survivors (M age  = 52.40; SD age  = 7.26). The analysis was carried out using a cross-sectional predictive study. Approximately half of those in the sample suffered from clinically significant emotional distress. The predictor variables selected explained a high percentage of the variability in emotional problems and quality of life (51.10-77.10%). Avoidance explained a high percentage of the variance in anxiety, depression and general distress. A lower degree of participation in valuable activities contributed, more specifically, to explaining variability in depression. The quantity and availability of environmental reinforcement was closely related to quality of life. A decisive contribution towards promoting emotional well-being and quality of life can be made by nursing action aimed at diminishing those avoidance strategies related to the oncological experience which may distance patients from daily activities which are gratifying and congruent with their values. Copyright © 2017 Elsevier Ltd. All rights reserved.

Vegetation greenness impacts on maximum and minimum temperatures in northeast Colorado

USGS Publications Warehouse

Hanamean, J. R.; Pielke, R.A.; Castro, C. L.; Ojima, D.S.; Reed, Bradley C.; Gao, Z.

2003-01-01

The impact of vegetation on the microclimate has not been adequately considered in the analysis of temperature forecasting and modelling. To fill part of this gap, the following study was undertaken.A daily 850–700 mb layer mean temperature, computed from the National Center for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) reanalysis, and satellite-derived greenness values, as defined by NDVI (Normalised Difference Vegetation Index), were correlated with surface maximum and minimum temperatures at six sites in northeast Colorado for the years 1989–98. The NDVI values, representing landscape greenness, act as a proxy for latent heat partitioning via transpiration. These sites encompass a wide array of environments, from irrigated-urban to short-grass prairie. The explained variance (r2 value) of surface maximum and minimum temperature by only the 850–700 mb layer mean temperature was subtracted from the corresponding explained variance by the 850–700 mb layer mean temperature and NDVI values. The subtraction shows that by including NDVI values in the analysis, the r2 values, and thus the degree of explanation of the surface temperatures, increase by a mean of 6% for the maxima and 8% for the minima over the period March–October. At most sites, there is a seasonal dependence in the explained variance of the maximum temperatures because of the seasonal cycle of plant growth and senescence. Between individual sites, the highest increase in explained variance occurred at the site with the least amount of anthropogenic influence. This work suggests the vegetation state needs to be included as a factor in surface temperature forecasting, numerical modeling, and climate change assessments.

Conductivity, A Simple Method to Probe Micellar Solutions

NASA Astrophysics Data System (ADS)

Bachofer, Steven J.

1996-09-01

A conductivity experiment on the tetradecyltrimethylammonium X-benzoate surfactants and the corresponding sodium X-benzoate salts demonstrates how this physical property can be applied to the study of the complex equilibria of ionic micellar aggregates. The surfactant CMC and fractional ionization constant (alpha) values are determined from the conductivity measurements. A student class studies the surfactants, in which a number of substituted benzoate counterions are utilized, and can be introduced to Quantitative Structure-Activity Relationships (QSAR) to explain the resulting CMC values. High quality data can be recorded with ease. The data from a student class illustrate that CMC values are sensitive to the hydrophobicity of the X-benzoate anion. However, hydrophobicity is not the only important parameter to be considered. The student class can propose other important factors with some additional reading of the colloidal literature.

Determination of Dimensionless Attenuation Coefficient in Shaped Resonators

NASA Technical Reports Server (NTRS)

Daniels, C.; Steinetz, B.; Finkbeiner, J.; Raman, G.; Li, X.

2003-01-01

The value of dimensionless attenuation coefficient is an important factor when numerically predicting high-amplitude acoustic waves in shaped resonators. Both the magnitude of the pressure waveform and the quality factor rely heavily on this dimensionless parameter. Previous authors have stated the values used, but have not completely explained their methods. This work fully describes the methodology used to determine this important parameter. Over a range of frequencies encompassing the fundamental resonance, the pressure waves were experimentally measured at each end of the shaped resonators. At the corresponding dimensionless acceleration, the numerical code modeled the acoustic waveforms generated in the resonator using various dimensionless attenuation coefficients. The dimensionless attenuation coefficient that most closely matched the pressure amplitudes and quality factors of the experimental and numerical results was determined to be the value to be used in subsequent studies.

Turbulent transport stabilization by ICRH minority fast ions in low rotating JET ILW L-mode plasmas

NASA Astrophysics Data System (ADS)

Bonanomi, N.; Mantica, P.; Di Siena, A.; Delabie, E.; Giroud, C.; Johnson, T.; Lerche, E.; Menmuir, S.; Tsalas, M.; Van Eester, D.; Contributors, JET

2018-05-01

The first experimental demonstration that fast ion induced stabilization of thermal turbulent transport takes place also at low values of plasma toroidal rotation has been obtained in JET ILW (ITER-like wall) L-mode plasmas with high (3He)-D ICRH (ion cyclotron resonance heating) power. A reduction of the gyro-Bohm normalized ion heat flux and higher values of the normalized ion temperature gradient have been observed at high ICRH power and low NBI (neutral beam injection) power and plasma rotation. Gyrokinetic simulations indicate that ITG (ion temperature gradient) turbulence stabilization induced by the presence of high-energetic 3He ions is the key mechanism in order to explain the experimental observations. Two main mechanisms have been identified to be responsible for the turbulence stabilization: a linear electrostatic wave-fast particle resonance mechanism and a nonlinear electromagnetic mechanism. The dependence of the stabilization on the 3He distribution function has also been studied.

Can high seismic b-values be explained solely by poorly applied methodology?

NASA Astrophysics Data System (ADS)

Roberts, Nick; Bell, Andrew; Main, Ian

2015-04-01

The b-value of the Gutenberg-Richter distribution quantifies the relative proportion of large to small magnitude earthquakes in a catalogue, in turn related to the population of fault rupture areas and the average slip or stress drop. Accordingly the b-value is an important parameter to consider when evaluating seismic catalogues as it has the potential to provide insight into the temporal or spatial evolution of the system, such as fracture development or changes in the local stress regime. The b-value for tectonic seismicity is commonly found to be close to 1, whereas much higher b-values are frequently reported for volcanic and induced seismicity. Understanding these differences is important for understanding the processes controlling earthquake occurrence in different settings. However, it is possible that anomalously high b-values could arise from small sample sizes, under-estimated completeness magnitudes, or other poorly applied methodologies. Therefore, it is important to establish a rigorous workflow for analyzing these datasets. Here we examine the frequency-magnitude distributions of volcanic earthquake catalogues in order to determine the significance of apparently high b-values. We first derive a workflow for computing the completeness magnitude of a seismic catalogue, using synthetic catalogues of varying shape, size, and known b-value. We find the best approach involves a combination of three methods: 'Maximum Curvature', 'b-value stability', and the 'Goodness-of-Fit test'. To calculate a reliable b-value with an error ≤0.25, the maximum curvature method is preferred for a 'sharp-peaked' discrete distribution. For a catalogue with a broader peak the b-value stability method is the most reliable with the Goodness-of-Fit test being an acceptable backup if the b-value stability method fails. We apply this workflow to earthquake catalogues from El Hierro (2011-2013) and Mt Etna (1999-2013) volcanoes. In general, we find the b-value to be equal to or slightly greater than 1, however, reliably high b-values are reported in both catalogues. We argue that many of the almost axiomatically 'high' b-values reported in the literature for volcanic and induced seismicity may be attributable to biases introduced by the methods of inference used and/or the relatively small sample sizes often available. This new methodology, although focused towards volcanic catalogues, is applicabale to all seismic catalogues.

Determination of the N2 recombination rate coefficient in the ionosphere

NASA Technical Reports Server (NTRS)

Orsini, N.; Torr, D. G.; Brinton, H. C.; Brace, L. H.; Hanson, W. B.; Hoffman, J. H.; Nier, A. O.

1977-01-01

Measurements of aeronomic parameters made by the Atmosphere Explorer-C satellite are used to determine the recombination rate coefficient of N2(+) in the ionosphere. The rate is found to increase significantly with decreasing electron density. Values obtained range from approximately 1.4 x 10 to the -7th to 3.8 x 10 to the -7th cu cm/sec. This variation is explained in a preliminary way in terms of an increase in the rate coefficient with vibrational excitation. Thus, high electron densities depopulate high vibrational levels reducing the effective recombination rate, whereas, low electron densities result in an enhancement in the population of high vibrational levels, thus, increasing the effective recombination rate.

Energy budget above a high-elevation subalpine forest in complex topography

USGS Publications Warehouse

Turnipseed, A.A.; Blanken, P.D.; Anderson, D.E.; Monson, Russell K.

2002-01-01

Components of the energy budget were measured above a subalpine coniferous forest over two complete annual cycles. Sensible and latent heat fluxes were measured by eddy covariance. Bowen ratios ranged from 0.7 to 2.5 in the summer (June-September) depending upon the availability of soil water, but were considerably higher (???3-6) during winter (December-March). Energy budget closure averaged better than 84% on a half-hourly basis in both seasons with slightly greater closure during the winter months. The energy budget showed a dependence on friction velocity (u*), approaching complete closure at u* values greater than 1 m s-1. The dependence of budget closure on u* explained why energy balance was slightly better in the winter as opposed to summer, since numerous periods of high turbulence occur in winter. It also explained the lower degree of energy closure (???10% less) during easterly upslope flow since these periods were characterized by low wind speeds (U < 4 m s-1) and friction velocities (u* < 0.5 m s-1). Co-spectral analysis suggests a shift of flux density towards higher frequencies under conditions where closure was obtained. It is suggested that low frequency contributions to the flux and advection were responsible for the lack of day-time energy budget closure. These effects were reduced at high friction velocities observed at our site. Our ability to close the energy budget at night was also highly dependent on friction velocity, approaching near closure (???90%) at u* values between 0.7 and 1.1 m s-1. Below this range, the airflow within the canopy becomes decoupled with the flow above. Above this range, insufficient temperature resolution of the sonic anemometer obscured the small temperature fluctuations, rendering measurements intractable. ?? 2002 Elsevier Science B.V. All rights reserved.

Analysis of the saturation phenomena of the neutralization rate of positively charged 218Po in water vapor.

PubMed

Tan, Yanliang; Xiao, Detao; Shan, Jian; Zhou, Qingzhi; Qu, Jingnian

2014-09-01

Generally, 88% of the freshly generated 218Po ions decayed from 222Rn are positively charged. These positive ions become neutralized by recombination with negative ions, and the main source of the negative ions is the OH- ions formed by radiolysis of water vapor. However, the neutralization rate of positively charged 218Po versus the square root of the concentration of H2O will be a constant when the concentration of H2O is sufficiently high. Since the electron affinity of the hydroxyl radical formed by water vapor is high, the authors propose that the hydroxyl radical can grab an electron to become OH-. Because the average period of collision with other positively charged ions and the average life of the OH- are much longer than those of the electron, the average concentration of negative ions will grow when the water vapor concentration increases. The authors obtained a model to describe the growth of OH- ions. From this model, it was found that the maximum value of the OH- ion concentration is limited by the square root of the radon concentration. If the radon concentration is invariant, the OH- ion concentration should be approximately a constant when the water vapor concentration is higher than a certain value. The phenomenon that the neutralization rate of positively charged 218Po versus the square root of the water vapor concentration will be saturated when the water vapor concentration is sufficiently high can be explained by this mechanism. This mechanism can be used also to explain the phenomenon that the detection efficiency of a radon monitor based on the electrostatic collection method seems to be constant when the water vapor concentration is high.

Study of molybdenum-aluminum interdiffusion kinetics and contact resistance for VLSI applications

NASA Astrophysics Data System (ADS)

Singh, R. N.; Brown, D. M.; Kim, M. J.; Smith, G. A.

1985-12-01

Interdiffusion barrier characteristics of molybdenum thin film with aluminum-1% Si is studied between 733 and 763 K via sheet and contact resistance measurements, Rutherford backscattering spectrometry, secondary ion mass spectrometry, and x-ray diffraction analysis. The results indicate that thermal annealing of Mo/Al-1% Si thin film couples leads to MoAl12 compound formation initially as a nonplanar front, but extensive annealing results in complete transformation of Al-1% Si to MoAl12 and a significant increase in contact resistance. The interdiffusion kinetics is diffusion controlled and shows parabolic time dependence, incubation periods, and extremely high activation energy value of 5.9 eV. The incubation periods and an high activation energy values are explained by the presence of silicon precipitates at the Mo/Al-1% Si interface. Implications of these observations to VLSI device characteristics are discussed and a safe time-temperature processing regime is proposed.

Relationship Between Frequency and Deflection Angle in the DNA Prism

PubMed Central

Chen, Zhen; Dorfman, Kevin D.

2013-01-01

The DNA prism is a modification of the standard pulsed-field electrophoresis protocol to provide a continuous separation, where the DNA are deflected at an angle that depends on their molecular weight. The standard switchback model for the DNA prism predicts a monotonic increase in the deflection angle as a function of the frequency for switching the field until a plateau regime is reached. However, experiments indicate that the deflection angle achieves a maximum value before decaying to a size-independent value at high frequencies. Using Brownian dynamics simulations, we show that the maximum in the deflection angle is related to the reorientation time for the DNA and the decay in deflection angle at high frequencies is due to inadequate stretching. The generic features of the dependence of the deflection angle on molecular weight, switching frequency, and electric field strength explain a number of experimental phenomena. PMID:23410375

The Value of Lung Cancer CT Screening: It Is All about Implementation.

PubMed

Goulart, Bernardo H L

2015-01-01

Hospitals have been gradually implementing new lung cancer CT screening programs following the release of the U.S. Preventive Services Task Force grade B recommendation to screen individuals at high risk for lung cancer. Policy makers have legitimately questioned whether adoption of CT screening in the community will reproduce the mortality benefits seen in the National Lung Screening Trial (NLST) and whether the benefits of screening will justify the potentially high costs. Although three annual CT screening exams proved cost-effective for the patient population enrolled in the NLST, uncertainty still exists about whether CT screening will be cost-effective in practice. The value of CT screening will depend largely on the strategies used to implement it. This manuscript reviews the current reimbursement policies for CT screening and explains the relationship between implementation strategies and screening value on the basis of the NLST cost-effectiveness analysis and other published data. A subsequent discussion ensues about the potential implementation inefficiencies that can negatively affect the value of CT screening (e.g., selection of low-risk individuals for screening, inappropriate follow-up visits for screening-detected lung nodules, failure to offer smoking cessation interventions, and overuse of medical resources for clinically irrelevant incidental findings) and the actions that can be taken to mitigate these inefficiencies and increase the value of screening.

Magnetic studies of nickel ferrite nanoparticles prepared by sol-gel technique

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

Anumol, C. N.; Chithra, M.; Sahoo, Subasa C., E-mail: subasa@cukerala.ac.in

2016-05-06

Ni-ferrite nanoparticles were synthesized by sol–gel technique by varying the solvent concentration. X-ray diffraction studies confirmed the phase purity in the samples. The lattice constant and grain size were found to be in the range of 0.833-0.834 nm and 14-26 nm respectively. There was no systematic variation in magnetization value with the solvent concentration and grain size. The highest magnetization, remanence and coercivity values of 60 emu/g, 12 emu/g and 180 Oe respectively were observed at 300K in the present study for the sample prepared in 75ml of solvent. The observed magnetization value is 20% higher than the bulk value of 50more » emu/g. The magnetization, coercivity and remanence values were enhanced at 60K compared to those at 300K. The observed high magnetization value in the nanoparticles can be explained on the basis of modified cation distribution in the lattice sites. The enhanced magnetic properties at 60K may be understood due to the reduced thermal fluctuation and increased anisotropy at low temperature.« less

The role of African dust in the formation of Quaternary soils on Mallorca, Spain and implications for the genesis of Red Mediterranean soils

USGS Publications Warehouse

Muhs, D.R.; Budahn, J.; Avila, A.; Skipp, G.; Freeman, J.; Patterson, D.

2010-01-01

African dust additions explain the origin of terra rossa soils that are common on the carbonate-platform island of Mallorca, Spain. Mineralogical and geochemical analyses indicate that Quaternary carbonate eolianites on Mallorca have a very high purity, usually composed of more than 90% carbonate minerals (calcite, dolomite, and aragonite). In contrast, terra rossa soils developed on these eolianites have lower carbonate contents and contain higher concentrations of quartz and other silicates. Analyses of immobile trace elements indicate that the non-carbonate fractions of the eolianites have distinctive Zr/Hf, La/Yb, Cr/Sc and Th/Ta values that differ from the superjacent terra rossa soils. These observations indicate that even if sufficient dissolution of the eolianite had taken place to create the soils by residual accumulation, immobile element ratios in the soils require an external source. However, Zr/Hf, La/Yb, Cr/Sc and Th/Ta values in the soils fall within the range of values for these element ratios in African dust collected on Barbados and mainland Spain. We conclude that the silicate fractions of terra rossa soils on Mallorca are derived mainly, though not wholly, from far-traveled African dust, and this process may explain the origin of other terra rossa soils found in southern Europe. ?? 2010.

Critical current density of high-quality Bi2Sr2Ca2Cu3Ox thin films prepared by metalorganic chemical-vapor deposition

NASA Astrophysics Data System (ADS)

Yamasaki, H.; Endo, K.; Nakagawa, Y.; Umeda, M.; Kosaka, S.; Misawa, S.; Yoshida, S.; Kajimura, K.

1992-10-01

Critical current densities Jc were measured in as-deposited, c-axis-oriented Bi2Sr2Ca2Cu3Ox thin films with Tc values as high as 97 K, which were prepared by metalorganic chemical-vapor deposition. These films showed high Jc (≳109 A/m2) at 77.3 K in high magnetic fields (≥1 T, H∥a-b plane). The best values are 3.3×109 A/m2 at 1 T and 9.1×108 A/m2 at 8 T, which are the highest Jc for Bi-oxide thin films among those reported so far. There were no signs of weak links in the Jc(H) behavior, and the surface morphology examined by scanning electron microscopy showed no apparent grain boundaries. The values of Jc decreased sharply when the applied field deviated from the a-b plane, and went to zero at the angles where the field component in the c direction is nearly equal to the irreversibility field Hc2* parallel to the c axis. The angular dependence of Jc of these films is most reasonably explained by the theory of intrinsic pinning.

Template-independent DNA synthesis activity associated with the reverse transcriptase of the long terminal repeat retrotransposon Tf1.

PubMed

Oz-Gleenberg, Iris; Herzig, Eytan; Hizi, Amnon

2012-01-01

Reverse transcriptases (RTs) possess a non-templated addition (NTA) activity while synthesizing DNA with blunt-ended DNA primer/templates. Interestingly, the RT of the long terminal repeat retrotransposon Tf1 has an NTA activity that is substantially higher than that of HIV-1 or murine leukemia virus RTs. By performing steady state kinetics, we found that the differences between the NTA activities of Tf1 and HIV-1 RTs can be explained by the substantially lower K(M) value for the incoming dNTP of Tf1 RT (while the differences between the apparent k(cat) values of these two RTs are relatively small). Furthermore, the K(M) values, calculated for both RTs with the same dNTP, are much lower for the template-dependent synthesis (TDS) than those of NTA. However, TDS of HIV-1 RT is higher than that of Tf1 RT. The overall relative order of the apparent k(cat)/K(M) values for dATP is: HIV-1 RT (TDS) > Tf1 RT (TDS) > Tf1 RT (NTA) > HIV-1 RT (NTA). Under the employed conditions, Tf1 RT can add up to seven nucleotides to the blunt-ended substrate, while the other RTs add mostly a single nucleotide. The NTA activity of Tf1 RT is restricted to DNA primers. Furthermore, the NTA activity of Tf1 and HIV-1 RTs is suppressed by ATP, as it competes with the incoming dATP (although ATP is not incorporated by the NTA activity of the RTs). The unusually high NTA activity of Tf1 RT can explain why, after completing cDNA synthesis, the in vivo generated Tf1 cDNA has relatively long extra sequences beyond the highly conserved CA at its 3'-ends. © 2011 The Authors Journal compilation © 2011 FEBS.

Effects of land use changes on the ecosystem service values of coastal wetlands.

PubMed

Camacho-Valdez, Vera; Ruiz-Luna, Arturo; Ghermandi, Andrea; Berlanga-Robles, César A; Nunes, Paulo A L D

2014-10-01

Changes in the coastal landscape of Southern Sinaloa (Mexico), between 2000 and 2010, were analyzed to relate spatial variations in wetlands extent with the provision and economic value of the ecosystem services (ES). Remote sensing techniques applied to Landsat TM imagery were used to evaluate land use/land cover changes while the value transfer method was used to assess the value of ES by land cover category. Five wetland types and other four land covers were found as representative of the coastal landscape. Findings reveal a 14 % decrease in the saltmarsh/forested mangrove area and a 12 % increase in the area of shrimp pond aquaculture (artificial wetland) during the study period. ES valuation shows that the total value flow increased by 9 % from $215 to $233 million (2007 USD) during the 10-year period. This increase is explained as result of the high value worldwide assigned to saltmarsh. We recognize limitations in the transfer-based approach in quantifying and mapping ES values in the region, but this method provides with value estimates spatially defined, and also provides some guidance in the preliminary screening of policies and projected development in the context of data-scarce regions.

Characterizing the variability of food waste quality: A need for efficient valorisation through anaerobic digestion.

PubMed

Fisgativa, Henry; Tremier, Anne; Dabert, Patrick

2016-04-01

In order to determine the variability of food waste (FW) characteristics and the influence of these variable values on the anaerobic digestion (AD) process, FW characteristics from 70 papers were compiled and analysed statistically. Results indicated that FW characteristics values are effectively very variable and that 24% of these variations may be explained by the geographical origin, the type of collection source and the season of the collection. Considering the whole range of values for physicochemical characteristics (especially volatile solids (VS), chemical oxygen demand (COD) and biomethane potential (BMP)), FW show good potential for AD treatment. However, the high carbohydrates contents (36.4%VS) and the low pH (5.1) might cause inhibitions by the rapid acidification of the digesters. As regards the variation of FW characteristics, FW categories were proposed. Moreover, the adequacy of FW characteristics with AD treatment was discussed. Four FW categories were identified with critical characteristics values for AD performance: (1) the high dry matter (DM) and total ammonia nitrogen (TAN) content of FW collected with green waste, (2) the high cellulose (CEL) content of FW from the organic fraction of municipal solid waste, (3) the low carbon-to-nitrogen (C/N) ratio of FW collected during summer, (4) the high value of TAN and Na of FW from Asia. For these cases, an aerobic pre-treatment or a corrective treatment seems to be advised to avoid instabilities along the digestion. Finally, the results of this review-paper provide a data basis of values for FW characteristics that could be used for AD process design and environmental assessment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of Coulomb blockade and spin-flip scattering in tunneling magnetoresistance of FeCo-Si-O nanogranular films

NASA Astrophysics Data System (ADS)

Kumar, Hardeep; Ghosh, Santanu; Bürger, Danilo; Li, Lin; Zhou, Shengqiang; Kabiraj, Debdulal; Avasthi, Devesh Kumar; Grötzschel, Rainer; Schmidt, Heidemarie

2011-04-01

In this work, we report the effect of FeCo atomic fraction (0.33 < x < 0.54) and temperature on the electrical, magnetic, and tunneling magnetoresistance (TMR) properties of FeCo-Si-O granular films prepared by atom beam sputtering technique. Glancing angle x-ray diffraction and TEM studies reveal that films are amorphous in nature. The dipole-dipole interactions (particle-matrix mixing) is evident from zero-field cooled and field-cooled magnetic susceptibility measurements and the presence of oxides (mainly Fe-related) is observed by x-ray photoelectron spectroscopy analysis. The presence of Fe-oxides is responsible for the observed reduction of saturation magnetization and rapid increase in coercivity below 50 K. TMR has been observed in a wide temperature range, and a maximum TMR of -4.25% at 300 K is observed for x = 0.39 at a maximum applied field of 60 kOe. The fast decay of maximum TMR at high temperatures and lower TMR values at 300 K when compared to PFeCo2/(1+PFeCo2), where PFeCo is the spin polarization of FeCo are in accordance with a theoretical model that includes spin-flip scattering processes. The temperature dependent study of TMR effect reveals a remarkably enhanced TMR at low temperatures. The TMR value varies from -2.1% at 300 K to -14.5% at 5 K for x = 0.54 and a large MR value of -18.5% at 5 K for x = 0.39 is explained on the basis of theoretical models involving Coulomb blockade effects. Qualitatively particle-matrix mixing and the presence of Fe-oxides seems to be the source of spin-flip scattering, responsible for fast decay of TMR at high temperatures. A combination of higher order tunneling (in Coulomb blockade regime) and spin-flip scattering (high temperature regime) explains the temperature dependent TMR of these films.

Words matter: Reframing exercise is medicine for the general population to optimize motivation and create sustainable behaviour change.

PubMed

Fortier, Michelle; Guérin, Eva; Segar, Michelle L

2016-11-01

Exercise is medicine (EIM) is grounded in strong evidence regarding the benefits of physical activity. Despite the contributions of EIM initiatives worldwide, rates of physical inactivity remain alarmingly high. We propose a reframe of EIM for the general population to improve motivation and foster sustainable behaviour change. We draw on a solid knowledge-base to explain the value of broadening the nomenclature to physical activity and of promoting a message of well-being via enjoyable physical activity.

Planning for Program Design and Assessment Using Value Creation Frameworks

ERIC Educational Resources Information Center

Whisler, Laurel; Anderson, Rachel; Brown, Jenai

2017-01-01

This article explains a program design and planning process using the Value Creation Framework (VCF) developed by Wenger, Trayner, and de Laat (2011). The framework involves identifying types of value or benefit for those involved in the program, conditions and activities that support creation of that value, data that measure whether the value was…

Math-related career aspirations and choices within Eccles et al.'s expectancy-value theory of achievement-related behaviors.

PubMed

Lauermann, Fani; Tsai, Yi-Miau; Eccles, Jacquelynne S

2017-08-01

Which occupation to pursue is one of the more consequential decisions people make and represents a key developmental task. Yet the underlying developmental processes associated with either individual or group differences in occupational choices are still not well understood. This study contributes toward filling this gap, focusing in particular on the math domain. We examined two aspects of Eccles et al.'s (1983) expectancy-value theory of achievement-related behaviors: (a) the reciprocal associations between adolescents' expectancy and subjective task value beliefs and adolescents' career plans and (b) the multiplicative association between expectancies and values in predicting occupational outcomes in the math domain. Our analyses indicate that adolescents' expectancy and subjective task value beliefs about math and their math- or science-related career plans reported at the beginning and end of high school predict each other over time, with the exception of intrinsic interest in math. Furthermore, multiplicative associations between adolescents' expectancy and subjective task value beliefs about math predict math-related career attainment approximately 15 years after graduation from high school. Gender differences emerged regarding career-related beliefs and career attainment, with male students being more likely than female to both pursue and attain math-related careers. These gender differences could not be explained by differences in beliefs about math as an academic subject. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

High-Performance Sensors Based on Resistance Fluctuations of Single-Layer-Graphene Transistors.

PubMed

Amin, Kazi Rafsanjani; Bid, Aveek

2015-09-09

One of the most interesting predicted applications of graphene-monolayer-based devices is as high-quality sensors. In this article, we show, through systematic experiments, a chemical vapor sensor based on the measurement of low-frequency resistance fluctuations of single-layer-graphene field-effect-transistor devices. The sensor has extremely high sensitivity, very high specificity, high fidelity, and fast response times. The performance of the device using this scheme of measurement (which uses resistance fluctuations as the detection parameter) is more than 2 orders of magnitude better than a detection scheme in which changes in the average value of the resistance is monitored. We propose a number-density-fluctuation-based model to explain the superior characteristics of a noise-measurement-based detection scheme presented in this article.

High Fill Factors of Si Solar Cells Achieved by Using an Inverse Connection Between MOS and PN Junctions.

PubMed

Wang, Liang-Xing; Zhou, Zhi-Quan; Zhang, Tian-Ning; Chen, Xin; Lu, Ming

2016-12-01

Fill factors (FFs) of ~0.87 have been obtained for crystalline Si (c-Si) solar cells based on Ag front contacts after rapid thermal annealing. The usual single PN junction model fails to explain the high FF result. A metal/oxide/semiconductor (MOS) junction at the emitter is found to be inversely connected to the PN one, and when its barrier height/e is close to the open-circuit voltage of the solar cell, very high FF is obtainable. In this work, although the open-circuit voltage (<580 mV) is not high here, the efficiency of c-Si solar cell still reaches the state-of-the-art value (>20 %) due to the high FF achieved.

THE ENIGMA OF ETHIOPIAN SEX RATIOS AT BIRTH.

PubMed

Garenne, Michel

2017-09-01

This study analysed sex ratios at birth (defined as the number of male births per 100 female births) using data on children ever-born from three censuses conducted in Ethiopia in 1984, 1994 and 2007. The results showed very high values by any standard, with an average of 108.4 for a sample of some 8.2 million births, with somewhat lower values in urban areas. Analysis of socioeconomic correlates revealed that the sex ratio varied very much by household wealth, from about 110 for very poor women to about 102 for wealthier women. The high value of the sex ratio at birth in Ethiopia could be explained by poverty, used as a proxy for poor nutritional status. In multivariate analysis, the effects of living in urban areas and of maternal education were less important than household wealth. Among the many ethno-linguistic groups, the Nilotic family had higher sex ratios than other groups. The results were confirmed using data from DHS surveys conducted in the country, and by the analysis of children still living at time of census.

Disgust sensitivity and the 'non-rational' aspects of a career choice in surgery.

PubMed

Consedine, Nathan S; Yu, Tzu-Chieh; Hill, Andrew G; Windsor, John A

2013-03-15

Fitting trainee physicians to career paths remains an ongoing challenge in a highly fluid health workforce environment. Studies attempting to explain low interest in surgical careers have typically examined the relative impact of career and lifestyle values. The current work argues that emotional proclivities are potentially more important and that disgust sensitivity may help explain both low surgical interest as well as the tendency for female students to avoid surgical careers. 216 medical students attending a required course in human behaviour completed measures of career intention, traditional predictors of career intention and dispositional disgust sensitivity. As predicted, logistic regression showed that greater disgust sensitivity predicted lower surgical career intention even when controlling for traditional career values (OR=0.45, 95%CI=0.21-0.95). Additionally, the gender effect indexing low female interest in surgical careers was no longer significant once disgust sensitivity was added to the model. The impact of disgust sensitivity on surgical interest was substantial and on par with established predictors of career intention. Disgust sensitivity may represent a potentially modifiable factor impacting surgical career choice, particularly among female students who are typically more disgust sensitive.

Explaining health care expenditure variation: large-sample evidence using linked survey and health administrative data.

PubMed

Ellis, Randall P; Fiebig, Denzil G; Johar, Meliyanni; Jones, Glenn; Savage, Elizabeth

2013-09-01

Explaining individual, regional, and provider variation in health care spending is of enormous value to policymakers but is often hampered by the lack of individual level detail in universal public health systems because budgeted spending is often not attributable to specific individuals. Even rarer is self-reported survey information that helps explain this variation in large samples. In this paper, we link a cross-sectional survey of 267 188 Australians age 45 and over to a panel dataset of annual healthcare costs calculated from several years of hospital, medical and pharmaceutical records. We use this data to distinguish between cost variations due to health shocks and those that are intrinsic (fixed) to an individual over three years. We find that high fixed expenditures are positively associated with age, especially older males, poor health, obesity, smoking, cancer, stroke and heart conditions. Being foreign born, speaking a foreign language at home and low income are more strongly associated with higher time-varying expenditures, suggesting greater exposure to adverse health shocks. Copyright © 2013 John Wiley & Sons, Ltd.

Matched samples logistic regression in case-control studies with missing values: when to break the matches.

PubMed

Hansson, Lisbeth; Khamis, Harry J

2008-12-01

Simulated data sets are used to evaluate conditional and unconditional maximum likelihood estimation in an individual case-control design with continuous covariates when there are different rates of excluded cases and different levels of other design parameters. The effectiveness of the estimation procedures is measured by method bias, variance of the estimators, root mean square error (RMSE) for logistic regression and the percentage of explained variation. Conditional estimation leads to higher RMSE than unconditional estimation in the presence of missing observations, especially for 1:1 matching. The RMSE is higher for the smaller stratum size, especially for the 1:1 matching. The percentage of explained variation appears to be insensitive to missing data, but is generally higher for the conditional estimation than for the unconditional estimation. It is particularly good for the 1:2 matching design. For minimizing RMSE, a high matching ratio is recommended; in this case, conditional and unconditional logistic regression models yield comparable levels of effectiveness. For maximizing the percentage of explained variation, the 1:2 matching design with the conditional logistic regression model is recommended.

Understanding the devaluation of vulnerable groups: A novel application of Institutional Anomie Theory.

PubMed

Hövermann, Andreas; Groß, Eva M; Zick, Andreas; Messner, Steven F

2015-07-01

Prejudices legitimize the discrimination against groups by declaring them to be of unequal, especially of less, worth. This legitimizing power is highly relevant in social conflicts of modern societies that are governed by market-oriented value systems. However, prejudice research has yet to be linked to sociological discourses on the marketization of society. We argue that Institutional Anomie Theory (IAT), a theory originally developed to explain crime rates, offers a fruitful macro-sociological framework for a better understanding of micro-social prejudices that emerge along with processes of marketization. Extending IAT to explain prejudices in a German study based on survey data offers a first attempt to underpin our theoretical hypotheses with empirical data. Although the results need to be interpreted with due caution, they suggest that the extended IAT model can be usefully applied to explain how a marketized mentality is related to different forms of institutional integration, and how it is conducive to specific prejudices that emerge in market-dominated societies against purported economically burdening social groups. Copyright © 2015 Elsevier Inc. All rights reserved.

UNDERSTANDING THE DEVALUATION OF VULNERABLE GROUPS: A NOVEL APPLICATION OF INSTITUTIONAL ANOMIE THEORY

PubMed Central

Groß, Eva M.; Zick, Andreas; Messner, Steven F.

2015-01-01

Prejudices legitimize the discrimination against groups by declaring them to be of unequal, especially of less, worth. This legitimizing power is highly relevant in social conflicts of modern societies that are governed by market-oriented value systems. However, prejudice research has yet to be linked to sociological discourses on the marketization of society. We argue that Institutional Anomie Theory (IAT), a theory originally developed to explain crime rates, offers a fruitful macro-sociological framework for a better understanding of micro-social prejudices that emerge along with processes of marketization. Extending IAT to explain prejudices in a German study based on survey data offers a first attempt to underpin our theoretical hypotheses with empirical data. Although the results need to be interpreted with due caution, they suggest that the extended IAT model can be usefully applied to explain how a marketized mentality is related to different forms of institutional integration, and how it is conducive to specific prejudices that emerge in market-dominated societies against purported economically burdening social groups. PMID:26004470

Benthic iron cycling in a high-oxygen environment: Implications for interpreting the Archean sedimentary iron isotope record.

PubMed

McCoy, V E; Asael, D; Planavsky, N

2017-09-01

The most notable trend in the sedimentary iron isotope record is a shift at the end of the Archean from highly variable δ 56 Fe values with large negative excursions to less variable δ 56 Fe values with more limited negative values. The mechanistic explanation behind this trend has been extensively debated, with two main competing hypotheses: (i) a shift in marine redox conditions and the transition to quantitative iron oxidation; and (ii) a decrease in the signature of microbial iron reduction in the sedimentary record because of increased bacterial sulfate reduction (BSR). Here, we provide new insights into this debate and attempt to assess these two hypotheses by analyzing the iron isotope composition of siderite concretions from the Carboniferous Mazon Creek fossil site. These concretions precipitated in an environment with water column oxygenation, extensive sediment pile dissimilatory iron reduction (DIR) but limited bacterial sulfate reduction (BSR). Most of the concretions have slightly positive iron isotope values, with a mean of 0.15‰ and limited iron isotope variability compared to the Archean sedimentary record. This limited variability in an environment with high DIR and low BSR suggests that these conditions alone are insufficient to explain Archean iron isotope compositions. Therefore, these results support the idea that the unusually variable and negative iron isotope values in the Archean are due to dissimilatory iron reduction (DIR) coupled with extensive water column iron cycling. © 2017 John Wiley & Sons Ltd.

Asymmetric behavior of the B(E2↑;0+ → 2+) values in 104-130Sn and generalized seniority

NASA Astrophysics Data System (ADS)

Maheshwari, Bhoomika; Jain, Ashok Kumar; Singh, Balraj

2016-08-01

We present freshly evaluated B (E 2 ↑ ;0+ →2+) values across the even-even Sn-isotopes which confirm the presence of an asymmetric behavior as well as a dip in the middle of the full valence space. We explain these features by using the concept of generalized seniority. The dip in the B (E 2) values near 116Sn is understood in terms of a change in the dominant orbits before and after the mid shell, which also explains the presence of asymmetric peaks in the B (E 2) values. This approach helps in deciding the most active valence spaces for a given set of isotopes, and single out the most useful truncation scheme for Large Scale Shell Model (LSSM) calculations. The LSSM calculations so guided by generalized seniority are also able to reproduce the experimental data on B (E 2) ↑ values quite well.

β Coronae Bolealis: Lithium and Cerium Contribution to the Blend at 6708 Å

NASA Astrophysics Data System (ADS)

Drake, N. A.; Hubrig, S.; Polosukhina, N. S.; de La Reza, R.

2006-06-01

We analyze the Li I 6708 Å spectral region of the chemically peculiar Ap star βCrB using high resolution, high signal-to-noise spectra obtained at different rotation phases. Our study shows that the Ce II line at 6708.099 Å is a main contributor to the spectral feature at 6708 Å. This fact explains the observed red shift of the Li I doublet of about 0.2 Å found by Hack et al. (1997). We derive the values of lithium and cerium abundances for different rotation phases and show that βCrB has ``cosmic'' Li abundance.

Thermoelectric refrigeration for temperatures below 100 K: A study of titanium sesquioxide

NASA Technical Reports Server (NTRS)

Redebaugh, R.; Linenberger, D.; Spellicy, E.

1982-01-01

Previous measurements of the specific heat of V-doped Ti2O3 at low temperatures were explained by a model which also suggested the material would have a high thermoelectric figure-of-merit. The sample preparation, experimental apparatus, and the results of measurements on the thermal conductivity, thermoelectric power, and electrical resistivity of a single crystal Ti2O3 - 4% V sample are described. The results are used to derive the thermoelectric figure-of-merit between 5 and 300 K. The figure-of-merit is much smaller than expected and of little practical value because of the very high phonon thermal conductivity.

Magnesium and iron isotopes in 2.7 Ga Alexo komatiites: Mantle signatures, no evidence for Soret diffusion, and identification of diffusive transport in zoned olivine

NASA Astrophysics Data System (ADS)

Dauphas, Nicolas; Teng, Fang-Zhen; Arndt, Nicholas T.

2010-06-01

Komatiites from Alexo, Canada, are well preserved and represent high-degree partial mantle melts (˜50%). They are thus well suited for investigating the Mg and Fe isotopic compositions of the Archean mantle and the conditions of magmatic differentiation in komatiitic lavas. High precision Mg and Fe isotopic analyses of 22 samples taken along a 15-m depth profile in a komatiite flow are reported. The δ 25Mg and δ 26Mg values of the bulk flow are -0.138 ± 0.021‰ and -0.275 ± 0.042‰, respectively. These values are indistinguishable from those measured in mantle peridotites and chondrites, and represent the best estimate of the composition of the silicate Earth from analysis of volcanic rocks. Excluding the samples affected by secondary Fe mobilization, the δ 56Fe and δ 57Fe values of the bulk flow are +0.044 ± 0.030‰, and +0.059 ± 0.044‰, respectively. These values are consistent with a near-chondritic Fe isotopic composition of the silicate Earth and minor fractionation during komatiite magma genesis. In order to explain the early crystallization of pigeonite relative to augite in slowly cooled spinifex lavas, it was suggested that magmas trapped in the crystal mush during spinifex growth differentiated by Soret effect, which should be associated with large and coupled variations in the isotopic compositions of Mg and Fe. The lack of variations in Mg and Fe isotopic ratios either rules out the Soret effect in the komatiite flow or the effect is effaced as the solidification front migrates downward through the flow crust. Olivine separated from a cumulate sample has light δ 56Fe and slightly heavy δ 26Mg values relative to the bulk flow, which modeling shows can be explained by kinetic isotope fractionation associated with Fe-Mg inter-diffusion in olivine. Such variations can be used to identify diffusive processes involved in the formation of zoned minerals.

Time perspectives and convenience food consumption among teenagers in Vietnam: The dual role of hedonic and healthy eating values.

PubMed

Olsen, Svein Ottar; Tuu, Ho Huy

2017-09-01

This study uses the subscales of Consideration of Future Consequences (CFC) to explore the effects of future (CFC-future) and immediate (CFC-immediate) on convenience food consumption among teenagers in Vietnam. Furthermore, we investigate the mediating and dual role of hedonic and healthy eating values in the relationships between CFCs and convenience food consumption. Survey data from 451 teenagers in Central Vietnam and structural equation modelling were used to test the relationships in a proposed theoretical model. The results indicate that while CFC-immediate and hedonic eating value has a positive direct effect, CFC-future and healthy eating value has a negative direct effect on convenience food consumption. The findings also reveal that both CFC-immediate and CFC-future have positive effects on hedonic and healthy eating values. However, this study argues and tests the relative importance of the direct (asymmetric) effects of time perspectives on eating values, and finds that while CFC-future dominate in explaining healthy eating values, CFC-immediate dominate in explaining hedonic eating values. Copyright © 2017 Elsevier Ltd. All rights reserved.

Integration of lead-free ferroelectric on HfO2/Si (100) for high performance non-volatile memory applications

PubMed Central

Kundu, Souvik; Maurya, Deepam; Clavel, Michael; Zhou, Yuan; Halder, Nripendra N.; Hudait, Mantu K.; Banerji, Pallab; Priya, Shashank

2015-01-01

We introduce a novel lead-free ferroelectric thin film (1-x)BaTiO3-xBa(Cu1/3Nb2/3)O3 (x = 0.025) (BT-BCN) integrated on to HfO2 buffered Si for non-volatile memory (NVM) applications. Piezoelectric force microscopy (PFM), x-ray diffraction, and high resolution transmission electron microscopy were employed to establish the ferroelectricity in BT-BCN thin films. PFM study reveals that the domains reversal occurs with 180° phase change by applying external voltage, demonstrating its effectiveness for NVM device applications. X-ray photoelectron microscopy was used to investigate the band alignments between atomic layer deposited HfO2 and pulsed laser deposited BT-BCN films. Programming and erasing operations were explained on the basis of band-alignments. The structure offers large memory window, low leakage current, and high and low capacitance values that were easily distinguishable even after ~106 s, indicating strong charge storage potential. This study explains a new approach towards the realization of ferroelectric based memory devices integrated on Si platform and also opens up a new possibility to embed the system within current complementary metal-oxide-semiconductor processing technology. PMID:25683062

Hidden symmetries in N-layer dielectric stacks

NASA Astrophysics Data System (ADS)

Liu, Haihao; Shoufie Ukhtary, M.; Saito, Riichiro

2017-11-01

The optical properties of a multilayer system with arbitrary N layers of dielectric media are investigated. Each layer is one of two dielectric media, with a thickness one-quarter the wavelength of light in that medium, corresponding to a central frequency f 0. Using the transfer matrix method, the transmittance T is calculated for all possible 2 N sequences for small N. Unexpectedly, it is found that instead of 2 N different values of T at f 0 (T 0), there are only (N/2+1) discrete values of T 0, for even N, and (N + 1) for odd N. We explain this high degeneracy in T 0 values by finding symmetry operations on the sequences that do not change T 0. Analytical formulae were derived for the T 0 values and their degeneracies as functions of N and an integer parameter for each sequence we call ‘charge’. Additionally, the bandwidth at f 0 and filter response of the transmission spectra are investigated, revealing asymptotic behavior at large N.

Growth kinetics of physical vapor transport processes: Crystal growth of the optoelectronic material mercurous chloride

NASA Technical Reports Server (NTRS)

Singh, N. B.; Duval, W. M.

1991-01-01

Physical vapor transport processes were studied for the purpose of identifying the magnitude of convective effects on the crystal growth process. The effects of convection on crystal quality were were studied by varying the aspect ratio and those thermal conditions which ultimately affect thermal convection during physical vapor transport. An important outcome of the present study was the observation that the convection growth rate increased up to a certain value and then dropped to a constant value for high aspect ratios. This indicated that a very complex transport had occurred which could not be explained by linear stability theory. Better quality crystals grown at a low Rayleigh number confirmed that improved properties are possible in convectionless environments.

Why anthropic reasoning cannot predict Lambda.

PubMed

Starkman, Glenn D; Trotta, Roberto

2006-11-17

We revisit anthropic arguments purporting to explain the measured value of the cosmological constant. We argue that different ways of assigning probabilities to candidate universes lead to totally different anthropic predictions. As an explicit example, we show that weighting different universes by the total number of possible observations leads to an extremely small probability for observing a value of Lambda equal to or greater than what we now measure. We conclude that anthropic reasoning within the framework of probability as frequency is ill-defined and that in the absence of a fundamental motivation for selecting one weighting scheme over another the anthropic principle cannot be used to explain the value of Lambda, nor, likely, any other physical parameters.

Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI.

PubMed

Colas, Jaron T; Pauli, Wolfgang M; Larsen, Tobias; Tyszka, J Michael; O'Doherty, John P

2017-10-01

Prediction-error signals consistent with formal models of "reinforcement learning" (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models-namely, "actor/critic" models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning.

Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI

PubMed Central

Pauli, Wolfgang M.; Larsen, Tobias; Tyszka, J. Michael; O’Doherty, John P.

2017-01-01

Prediction-error signals consistent with formal models of “reinforcement learning” (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models—namely, “actor/critic” models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning. PMID:29049406

Switching dynamics of TaOx-based threshold switching devices

NASA Astrophysics Data System (ADS)

Goodwill, Jonathan M.; Gala, Darshil K.; Bain, James A.; Skowronski, Marek

2018-03-01

Bi-stable volatile switching devices are being used as access devices in solid-state memory arrays and as the active part of compact oscillators. Such structures exhibit two stable states of resistance and switch between them at a critical value of voltage or current. A typical resistance transient under a constant amplitude voltage pulse starts with a slow decrease followed by a rapid drop and leveling off at a low steady state value. This behavior prompted the interpretation of initial delay and fast transition as due to two different processes. Here, we show that the entire transient including incubation time, transition time, and the final resistance values in TaOx-based switching can be explained by one process, namely, Joule heating with the rapid transition due to the thermal runaway. The time, which is required for the device in the conducting state to relax back to the stable high resistance one, is also consistent with the proposed mechanism.

Carbon-related platinum defects in silicon: An electron paramagnetic resonance study of high spin states

NASA Astrophysics Data System (ADS)

Scheerer, O.; Höhne, M.; Juda, U.; Riemann, H.

1997-10-01

In this article, we report about complexes in silicon investigated by electron paramagnetic resonance (EPR). In silicon doped with C and Pt we detected two different complexes: cr-1Pt (cr: carbon-related, 1Pt: one Pt atom) and cr-3Pt. The complexes have similar EPR properties. They show a trigonal symmetry with effective g-values geff,⊥=2g⊥≈4 and geff,‖=g‖≈2 (g⊥, g‖ true g-values). The g-values can be explained by a spin Hamiltonian with large fine-structure energy (electron spin S=3/2) and smaller Zeeman interaction. The participation of platinum in the complexes is proved by the hyperfine interaction. From experiments with varying carbon concentration we conclude that the complexes contain carbon. Atomistic models based on the Watkins vacancy-model for substitutional Pt were developed.

California Bearing Ratio (CBR) test on stabilization of clay with lime addition

NASA Astrophysics Data System (ADS)

Hastuty, I. P.; Roesyanto; Limbong, M. N.; Oberlyn, S. J.

2018-02-01

Clay is a type of soil with particles of certain minerals giving plastic properties when mixed with water. Soil has an important role in a construction, besides as a building material in a wide variety of civil engineering works, soil is also used as supporting foundation of the building. Basic properties of clay are rock-solid in dry and plastic with medium water content. In high water content, clay becomes sticky like (cohesive) and soften. Therefore, clay stabilization is necessary to repair soil’s mechanical properties. In this research, lime is use as a stabilizer that contains the Ca+ element to bond bigger particles. Lime used is slaked lime Ca(OH)2. Clay used has liquid limitation (LL) value of 47.33%, plasticity index of 29.88% and CBR value 6.29. The results explain about 10% lime mixture variation gives the optimum stabilized clay with CBR value of 8.75%.

Nutritive and health-promoting value of organic vegetables.

PubMed

Sobieralski, Krzysztof; Siwulski, Marek; Sas-Golak, Iwona

2013-01-01

In recent years in Poland we may observe a considerable development of organic vegetable production. Increased interest in organic products results from an opinion of the consumers on their high quality and health safety. However, results of research comparing nutritive value and contents of biologically active compounds in vegetables from organic and conventional farms are ambiguous. Most studies confirm higher contents of certain vitamins and antioxidants in organic vegetables, as well as their lower contents of nitrates and pesticide residue in comparison to vegetables grown in the conventional manner. There are also reports which did not confirm such differences or showed opposite trends. Research results at present do not make it possible to formulate a general conclusion on a higher health-promoting value of organic vegetables in comparison to those grown by conventional farming methods. It is necessary to continue research in order to explain the effect of organic raw materials on human health in a more comprehensive manner.

Hydrostatic compression of Fe(1-x)O wuestite

NASA Technical Reports Server (NTRS)

Jeanloz, R.; Sato-Sorensen, Y.

1986-01-01

Hydrostatic compression measurements on Fe(0.95)O wuestite up to 12 GPa yield a room temperature value for the isothermal bulk modulus of K(ot) = 157 (+ or - 10) GPa at zero pressure. This result is in accord with previous hydrostatic and nonhydrostatic measurements of K(ot) for wuestites of composition: 0.89 = Fe/O 0.95. Dynamic measurements of the bulk modulus by ultrasonic, shock-wave and neutron-scattering experiments tend to yield a larger value: K(ot) approximately 180 GPa. The discrepancy between static and dynamic values cannot be explained by the variation of K(ot) with composition, as has been proposed. This conclusion is based on high-precision compression data and on theoretical models of the effects of defects on elastic constants. Barring serious errors in the published measurements, the available data suggest that wuestite exhibits a volume relaxation under pressure.

Product Plan of New Generation System Camera "OLYMPUS PEN E-P1"

NASA Astrophysics Data System (ADS)

Ogawa, Haruo

"OLYMPUS PEN E-P1", which is new generation system camera, is the first product of Olympus which is new standard "Micro Four-thirds System" for high-resolution mirror-less cameras. It continues good sales by the concept of "small and stylish design, easy operation and SLR image quality" since release on July 3, 2009. On the other hand, the half-size film camera "OLYMPUS PEN" was popular by the concept "small and stylish design and original mechanism" since the first product in 1959 and recorded sale number more than 17 million with 17 models. By the 50th anniversary topic and emotional value of the Olympus pen, Olympus pen E-P1 became big sales. I would like to explain the way of thinking of the product plan that included not only the simple functional value but also emotional value on planning the first product of "Micro Four-thirds System".

Gas exchange on Mono Lake and Crowley Lake, California

NASA Technical Reports Server (NTRS)

Wanninkhof, Rik; Ledwell, James R.; Broecker, Wallace S.

1987-01-01

Gas exchange coefficients (k) have been determined for freshwater Crowley Lake and saline Mono Lake through the use of a man-made purposefully injected gas, SF6. The concentration decreased from an initial value of 40 to 4 pmol/L for Mono Lake and from 20 to 1 pmol/L for Crowley lake over a period of 6 wks. Wind-speed (u) records from anemometers on the shore of each lake made it possible to determine the relationship between k and u. The average u and k values for the experiment were identical for the two lakes, despite the large chemical differences. It is estimated that, for the u values observed over Mono Lake from July to December 1984, the exchange of CO2 occurred 2.5 times faster than without chemical enhancement. This is a factor of 4 lower than needed to explain the high invasion rate of C-14 produced by nuclear bomb tests.

Primordial helium entrained by the hottest mantle plumes

NASA Astrophysics Data System (ADS)

Jackson, M. G.; Konter, J. G.; Becker, T. W.

2017-02-01

Helium isotopes provide an important tool for tracing early-Earth, primordial reservoirs that have survived in the planet’s interior. Volcanic hotspot lavas, like those erupted at Hawaii and Iceland, can host rare, high 3He/4He isotopic ratios (up to 50 times the present atmospheric ratio, Ra) compared to the lower 3He/4He ratios identified in mid-ocean-ridge basalts that form by melting the upper mantle (about 8Ra; ref. 5). A long-standing hypothesis maintains that the high-3He/4He domain resides in the deep mantle, beneath the upper mantle sampled by mid-ocean-ridge basalts, and that buoyantly upwelling plumes from the deep mantle transport high-3He/4He material to the shallow mantle beneath plume-fed hotspots. One problem with this hypothesis is that, while some hotspots have 3He/4He values ranging from low to high, other hotspots exhibit only low 3He/4He ratios. Here we show that, among hotspots suggested to overlie mantle plumes, those with the highest maximum 3He/4He ratios have high hotspot buoyancy fluxes and overlie regions with seismic low-velocity anomalies in the upper mantle, unlike plume-fed hotspots with only low maximum 3He/4He ratios. We interpret the relationships between 3He/4He values, hotspot buoyancy flux, and upper-mantle shear wave velocity to mean that hot plumes—which exhibit seismic low-velocity anomalies at depths of 200 kilometres—are more buoyant and entrain both high-3He/4He and low-3He/4He material. In contrast, cooler, less buoyant plumes do not entrain this high-3He/4He material. This can be explained if the high-3He/4He domain is denser than low-3He/4He mantle components hosted in plumes, and if high-3He/4He material is entrained from the deep mantle only by the hottest, most buoyant plumes. Such a dense, deep-mantle high-3He/4He domain could remain isolated from the convecting mantle, which may help to explain the preservation of early Hadean (>4.5 billion years ago) geochemical anomalies in lavas sampling this reservoir.

How important is it to my parents? Transmission of STEM academic values: the role of parents' values and practices and children's perceptions of parental influences

NASA Astrophysics Data System (ADS)

Šimunović, Mara; Reić Ercegovac, Ina; Burušić, Josip

2018-06-01

The success of science education in classroom and out-of-school settings can be influenced by parents' behaviours and STEM-related values. The present study investigated pathways in parent-to-child transmission of STEM (science, technology, engineering, mathematics) values by examining at same time parents' values and behaviours, along with their children's perceptions of these parental influences. The study included 1071 students (Mage = 12.15) and the same number of their parents. Path analysis revealed that children's importance value of the STEM school fields was best explained by their perceptions of parental values and behaviours in STEM. On the other hand, parents' self-reported values and behaviours had a weak effect in predicting children's values, which can be explained by inaccurate children's perceptions of their parents. The results suggest that parents more easily convey beliefs about the utility than the attainment value of STEM. Namely, parents' utility value had a larger effect in predicting children's value, partly mediated through children's perception of parents' encouragement of STEM interests. The study highlights the role of children's perceptions of their parents' beliefs and behaviours and the importance of communicating STEM-related values within the family. Practical implications for parents and science educators are discussed.

Phosphofructokinase and mitochondria partially explain the high ultimate pH of broiler pectoralis major muscle.

PubMed

Matarneh, Sulaiman K; Yen, Con-Ning; Elgin, Jennifer M; Beline, Mariane; da Luz E Silva, Saulo; Wicks, Jordan C; England, Eric M; Dalloul, Rami A; Persia, Michael E; Omara, Islam I; Shi, Hao; Gerrard, David E

2018-05-01

During postmortem metabolism, muscle pH gradually declines to reach an ultimate pH near 5.6 across most meat species. Yet, broiler pectoralis major (P. major) muscle generates meat with high ultimate pH (pH ∼ 5.9). For better understanding of the underlying mechanism responsible for this phenomenon, we evaluated the involvement of breast muscle chilling on the extent of postmortem metabolism. Broiler breast muscles were either subjected to chilling treatment (control) or left at room temperature (RT) for 120 min. P. major muscle from the RT treatment had lower ultimate pH, greater glycogen degradation and lactate accumulation. While these findings suggest that carcass chilling can contribute to the premature termination of postmortem metabolism, chilling did not fully explain the high ultimate pH of P. major muscle. Our results also revealed that glucose-6-phosphate (G6P) was very low at 24 h, and therefore we hypothesized that G6P was limiting. To test this hypothesis, muscle samples from P. major and porcine longissimus lumborum (LL) muscle were homogenized into a reaction buffer that mimics postmortem glycolysis with or without 0.5 mg/mL isolated mitochondria. While samples containing porcine LL muscle reached the normal level of ultimate pH, P. major muscle samples reached a value similar to that observed in vivo even in the presence of excess G6P, indicating that G6P was not limiting. Mitochondria enhanced the glycolytic flux and pH decline in systems containing muscle from both species. More importantly, however, was that in vitro system containing chicken with mitochondria reached pH value similar to that of samples containing LL muscle without mitochondria. To investigate further, phosphofructokinase (PFK) activity was compared in broiler P. major and porcine LL muscle at different pH values. PFK activity was lower in P. major muscle at pH 7, 6.5, and 6.2 than LL muscle. In conclusion, carcass chilling can partially contribute to the high ultimate pH of broiler P. major muscle, while low PFK activity and mitochondria content limit the flux through glycolysis.

Write Procedures That Work.

ERIC Educational Resources Information Center

Cubberley, Carol W.

1991-01-01

Discusses written procedures that explain library tasks and describes methods for writing them clearly and coherently. The use of appropriate terminology and vocabulary is discussed; the value of illustrations, typography, and format to enhance the visual effect is explained; the intended audience is considered; and examples are given. (seven…

Biocultural aspects of obesity in young Mexican schoolchildren.

PubMed

Brewis, Alexandra

2003-01-01

Obesity related to over-nutrition is investigated in a sample of 219 Mexican children from affluent families, ages 6-12 years. Defined as weight-for-age at or above the 95(th) percentile, obesity rates in middle childhood are very high in this population, being 24.2% of children (29.4% of boys and 19.1% of girls). Binary logistic regression shows that children are more likely to be obese if they are boys, from small households with few or no other children, and have more permissive, less authoritarian parents. Diet at school and activity patterns, including television viewing, are not different for boys and girls and so do not explain this gender variation. The value placed on children, especially sons, in smaller middle-class families, can result in indulgent feeding because food treats are a cultural index of parental caring. Parents also value child fatness as a sign of health. These obese Mexican children have no greater social problems (peer rejection or stigma) or psychological problems (anxiety, depression, or low self esteem) than their non-obese peers. More study specifically focused on feeding practices in the home environment is required to explain very high rates of child obesity. The differences in obesity risk related to specific aspects of children's developmental microniche emphasize the importance of including a focus on gender as a socio-ecological construct in human biological studies of child growth, development, and nutrition. Copyright 2003 Wiley-Liss, Inc.

Re-Os and Lu-Hf isotopic constraints on the formation and age of mantle pyroxenites from the Bohemian Massif

NASA Astrophysics Data System (ADS)

Ackerman, Lukáš; Bizimis, Michael; Haluzová, Eva; Sláma, Jiří; Svojtka, Martin; Hirajima, Takao; Erban, Vojtěch

2016-07-01

We report on the Lu-Hf and Re-Os isotope systematics of a well-characterized suite of spinel and garnet pyroxenites from the Gföhl Unit of the Bohemian Massif (Czech Republic, Austria). Lu-Hf mineral isochrons of three pyroxenites yield undistinguishable values in the range of 336-338 Ma. Similarly, the slope of Re-Os regression for most samples yields an age of 327 ± 31 Ma. These values overlap previously reported Sm-Nd ages on pyroxenites, eclogites and associated peridotites from the Gföhl Unit, suggesting contemporaneous evolution of all these HT-HP rocks. The whole-rock Hf isotopic compositions are highly variable with initial εHf values ranging from - 6.4 to + 66. Most samples show a negative correlation between bulk rock Sm/Hf and εHf and, when taking into account other characteristics (e.g., high 87Sr/86Sr), this may be explained by the presence of recycled oceanic sediments in the source of the pyroxenite parental melts. A pyroxenite from Horní Kounice has decoupled Hf-Nd systematics with highly radiogenic initial εHf of + 66 for a given εNd of + 7.8. This decoupling is consistent with the presence of a melt derived from a depleted mantle component with high Lu/Hf. Finally, one sample from Bečváry plots close to the MORB field in Hf-Nd isotope space consistent with its previously proposed origin as metamorphosed oceanic gabbro. Some of the websterites and thin-layered pyroxenites have variable, but high Os concentrations paralleled by low initial γOs. This reflects the interaction of the parental pyroxenitic melts with a depleted peridotite wall rock. In turn, the radiogenic Os isotope compositions observed in most pyroxenite samples is best explained by mixing between unradiogenic Os derived from peridotites and a low-Os sedimentary precursor with highly radiogenic 187Os/188Os. Steep increase of 187Os/188Os at nearly uniform 187Re/188Os found in a few pyroxenites may be connected with the absence of primary sulfides, but the presence of minor late stage sulfide-bearing veinlets likely associated with HT-HP metamorphism at crustal conditions.

Tract-specific fractional anisotropy predicts cognitive outcome in a community sample of middle-aged participants with white matter lesions

PubMed Central

Soriano-Raya, Juan José; Miralbell, Júlia; López-Cancio, Elena; Bargalló, Núria; Arenillas, Juan Francisco; Barrios, Maite; Cáceres, Cynthia; Toran, Pere; Alzamora, Maite; Dávalos, Antoni; Mataró, Maria

2014-01-01

Cerebral white matter lesions (WMLs) have been consistently related to cognitive dysfunction but the role of white matter (WM) damage in cognitive impairment is not fully determined. Diffusion tensor imaging is a promising tool to explain impaired cognition related to WMLs. We investigated the separate association of high-grade periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) with fractional anisotropy (FA) in middle-aged individuals. We also assessed the predictive value to cognition of FA within specific WM tracts associated with high-grade WMLs. One hundred participants from the Barcelona-AsIA Neuropsychology Study were divided into groups based on low- and high-grade WMLs. Voxel-by-voxel FA were compared between groups, with separate analyses for high-grade PVHs and DWMHs. The mean FA within areas showing differences between groups was extracted in each tract for linear regression analyses. Participants with high-grade PVHs and participants with high-grade DWMHs showed lower FA in different areas of specific tracts. Areas showing decreased FA in high-grade DWMHs predicted lower cognition, whereas areas with decreased FA in high-grade PVHs did not. The predictive value to cognition of specific WM tracts supports the involvement of cortico-subcortical circuits in cognitive deficits only in DWMHs. PMID:24549185

Tract-specific fractional anisotropy predicts cognitive outcome in a community sample of middle-aged participants with white matter lesions.

PubMed

Soriano-Raya, Juan José; Miralbell, Júlia; López-Cancio, Elena; Bargalló, Núria; Arenillas, Juan Francisco; Barrios, Maite; Cáceres, Cynthia; Toran, Pere; Alzamora, Maite; Dávalos, Antoni; Mataró, Maria

2014-05-01

Cerebral white matter lesions (WMLs) have been consistently related to cognitive dysfunction but the role of white matter (WM) damage in cognitive impairment is not fully determined. Diffusion tensor imaging is a promising tool to explain impaired cognition related to WMLs. We investigated the separate association of high-grade periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) with fractional anisotropy (FA) in middle-aged individuals. We also assessed the predictive value to cognition of FA within specific WM tracts associated with high-grade WMLs. One hundred participants from the Barcelona-AsIA Neuropsychology Study were divided into groups based on low- and high-grade WMLs. Voxel-by-voxel FA were compared between groups, with separate analyses for high-grade PVHs and DWMHs. The mean FA within areas showing differences between groups was extracted in each tract for linear regression analyses. Participants with high-grade PVHs and participants with high-grade DWMHs showed lower FA in different areas of specific tracts. Areas showing decreased FA in high-grade DWMHs predicted lower cognition, whereas areas with decreased FA in high-grade PVHs did not. The predictive value to cognition of specific WM tracts supports the involvement of cortico-subcortical circuits in cognitive deficits only in DWMHs.

Fat and lean tissue accretion in relation to reward motivation in children.

PubMed

De Decker, Annelies; De Clercq, Bart; Verbeken, Sandra; Wells, Jonathan C K; Braet, Caroline; Michels, Nathalie; De Henauw, Stefaan; Sioen, Isabelle

2017-01-01

'Reward sensitivity' explains inter-individual differences in the motivation to obtain rewards when reward cues are perceived. This psychobiological trait has been linked to higher consumption of palatable food when exposed to palatable food cues. The current study aims to examine if reward sensitivity explains differences in patterns of fat and lean tissue accretion over time in children. A longitudinal observational study with measurement waves in 2011 (baseline), 2012, 2013, and 2015 was conducted. The sample was a population-based Flemish cohort of children (n = 446, 50% boys and 5.5-12 years at baseline; 38.8% of the baseline sample also participated in 2015). Baseline reward sensitivity of the children was assessed by parent ratings on the Drive subscale of the Behavioral Inhibition System/Behavioral Approach System scales. Age- and sex-independent Fat and Lean Mass Index z-scores (zFMI and zLMI respectively) were computed for each study wave based on air-displacement plethysmography. In girls, but not boys, reward sensitivity was positively associated with the baseline zFMI and zLMI (95% confidence intervals of unstandardized estimates: 0.01 to 0.11 and 0.01 to 0.10 respectively, P values 0.01 and 0.02 respectively). Further, reward sensitivity explained 14.8% and 11.6% of the change in girls' zFMI and zLMI respectively over four years: the zFMI and zLMI increased and decreased respectively in high reward sensitive girls (95% confidence intervals of unstandardized estimates: 0.01 to 0.11 and -0.12 to -0.01 respectively, P values 0.01 and 0.02 respectively). Hence, girls high in reward sensitivity had significantly higher adiposity gain over four years parallel with lower increase in lean mass than was expected on the basis of their age and height. These results may help to identify appropriate targets for interventions for obesity prevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Connecting Inquiry and Values in Science Education. An Approach Based on John Dewey's Philosophy

NASA Astrophysics Data System (ADS)

Lee, Eun Ah; Brown, Matthew J.

2018-03-01

Conducting scientific inquiry is expected to help students make informed decisions; however, how exactly it can help is rarely explained in science education standards. According to classroom studies, inquiry that students conduct in science classes seems to have little effect on their decision-making. Predetermined values play a large role in students' decision-making, but students do not explore these values or evaluate whether they are appropriate to the particular issue they are deciding, and they often ignore relevant scientific information. We explore how to connect inquiry and values, and how this connection can contribute to informed decision-making based on John Dewey's philosophy. Dewey argues that scientific inquiry should include value judgments and that conducting inquiry can improve the ability to make good value judgments. Value judgment is essential to informed, rational decision-making, and Dewey's ideas can explain how conducting inquiry can contribute to make an informed decision through value judgment. According to Dewey, each value judgment during inquiry is a practical judgment guiding action, and students can improve their value judgments by evaluating their actions during scientific inquiry. Thus, we suggest that students need an opportunity to explore values through scientific inquiry and that practicing value judgment will help informed decision-makings.

Pb/InAs nanowire josephson junction with high critical current and magnetic flux focusing.

PubMed

Paajaste, J; Amado, M; Roddaro, S; Bergeret, F S; Ercolani, D; Sorba, L; Giazotto, F

2015-03-11

We have studied mesoscopic Josephson junctions formed by highly n-doped InAs nanowires and superconducting Ti/Pb source and drain leads. The current-voltage properties of the system are investigated by varying temperature and external out-of-plane magnetic field. Superconductivity in the Pb electrodes persists up to ∼7 K and with magnetic field values up to 0.4 T. Josephson coupling at zero backgate voltage is observed up to 4.5 K and the critical current is measured to be as high as 615 nA. The supercurrent suppression as a function of the magnetic field reveals a diffraction pattern that is explained by a strong magnetic flux focusing provided by the superconducting electrodes forming the junction.

Sound from apollo rockets in space.

PubMed

Cotten, D; Donn, W L

1971-02-12

Low-frequency sound has been recorded on at least two occasions in Bermuda with the passage of Apollo rocket vehicles 188 kilometers aloft. The signals, which are reminiscent of N-waves from sonic booms, are (i) horizontally coherent; (ii) have extremely high (supersonic) trace velocities across the tripartite arrays; (iii) have nearly identical appearance and frequencies; (iv) have essentially identical arrival times after rocket launch; and (v) are the only coherent signals recorded over many hours. These observations seem to establish that the recorded sound comes from the rockets at high elevation. Despite this high elevation, the values of surface pressure appear to be explainable on the basis of a combination of a kinetic theory approach to shock formation in rarefied atmospheres with established gas-dynamics shock theory.

Rare earth element patterns in Archean high-grade metasediments and their tectonic significance

NASA Technical Reports Server (NTRS)

Taylor, Stuart Ross; Rudnick, Roberta L.; Mclennan, Scott M.; Eriksson, Kenneth A.

1986-01-01

REE data on metasedimentary rocks from two different types of high-grade Archean terrains are presented and analyzed. The value of REEs as indicators of crustal evolution is explained; the three geologic settings (in North America, Southern Africa, and Australia) from which the samples were obtained are described; and the data are presented in extensive tables and graphs and discussed in terms of metamorphic effects, the role of accessory phases, provenance, and tectonic implications (recycling, the previous extent of high-grade terrains, and a model of Archean crustal growth). The diversity of REE patterns in shallow-shelf metasediments is attributed to local provenance, while the Eu-depleted post-Archean patterns are associated with K-rich plutons from small, stable early Archean terrains.

A Scaled-Projective Measure of Interpersonal Values

ERIC Educational Resources Information Center

Kilmann, Ralph H.

1975-01-01

The Kilmann Insight Test is a measure of the interpersonal value constructs. That is how the individual perceives and interprets the desirable and undesirable features of interpersonal behavior. The validity of the test is investigated by explaining its relationship to a self-report measure assessing similar values. (DEP)

Changes in liver stiffness measurement using acoustic radiation force impulse elastography after antiviral therapy in patients with chronic hepatitis C.

PubMed

Chen, Sheng-Hung; Lai, Hsueh-Chou; Chiang, I-Ping; Su, Wen-Pang; Lin, Chia-Hsin; Kao, Jung-Ta; Chuang, Po-Heng; Hsu, Wei-Fan; Wang, Hung-Wei; Chen, Hung-Yao; Huang, Guan-Tarn; Peng, Cheng-Yuan

2018-01-01

To compare on-treatment and off-treatment parameters acquired using acoustic radiation force impulse elastography, the Fibrosis-4 (FIB-4) index, and aspartate aminotransferase-to-platelet ratio index (APRI) in patients with chronic hepatitis C (CHC). Patients received therapies based on pegylated interferon or direct-acting antiviral agents. The changes in paired patient parameters, including liver stiffness (LS) values, the FIB-4 index, and APRI, from baseline to sustained virologic response (SVR) visit (24 weeks after the end of treatment) were compared. Multiple regression models were used to identify significant factors that explained the correlations with LS, FIB-4, and APRI values and SVR. A total of 256 patients were included, of which 219 (85.5%) achieved SVR. The paired LS values declined significantly from baseline to SVR visit in all groups and subgroups except the nonresponder subgroup (n = 10). Body mass index (P = 0.0062) and baseline LS (P < 0.0001) were identified as independent factors that explained the LS declines. Likewise, the baseline FIB-4 (P < 0.0001) and APRI (P < 0.0001) values independently explained the declines in the FIB-4 index and APRI, respectively. Moreover, interleukin-28B polymorphisms, baseline LS, and rapid virologic response were identified as independent correlates with SVR. Paired LS measurements in patients treated for CHC exhibited significant declines comparable to those in FIB-4 and APRI values. These declines may have correlated with the resolution of necroinflammation. Baseline LS values predicted SVR.

A Brief History of Educational "Value-Added": How Did We Get to Where We Are?

ERIC Educational Resources Information Center

Saunders, Lesley

1999-01-01

Explains how and why the economics concept "value added" came to be used in an educational context, focusing on early usage in the United Kingdom. The term has been developed, used, and defined in various, conflicting ways. Some ambiguities cannot be eliminated. Value-added effectiveness measures involve value judgments. (44 references)…

Systematic survey of high-resolution b value imaging along Californian faults: Inference on asperities

NASA Astrophysics Data System (ADS)

Tormann, T.; Wiemer, S.; Mignan, A.

2014-03-01

Understanding and forecasting earthquake occurrences is presumably linked to understanding the stress distribution in the Earth's crust. This cannot be measured instrumentally with useful coverage. However, the size distribution of earthquakes, quantified by the Gutenberg-Richter b value, is possibly a proxy to differential stress conditions and could therewith act as a crude stress-meter wherever seismicity is observed. In this study, we improve the methodology of b value imaging for application to a high-resolution 3-D analysis of a complex fault network. In particular, we develop a distance-dependent sampling algorithm and introduce a linearity measure to restrict our output to those regions where the magnitude distribution strictly follows a power law. We assess the catalog completeness along the fault traces using the Bayesian Magnitude of Completeness method and systematically image b values for 243 major fault segments in California. We identify and report b value structures, revisiting previously published features, e.g., the Parkfield asperity, and documenting additional anomalies, e.g., along the San Andreas and Northridge faults. Combining local b values with local earthquake productivity rates, we derive probability maps for the annual potential of one or more M6 events as indicated by the microseismicity of the last three decades. We present a physical concept of how different stressing conditions along a fault surface may lead to b value variation and explain nonlinear frequency-magnitude distributions. Detailed spatial b value information and its physical interpretation can advance our understanding of earthquake occurrence and ideally lead to improved forecasting ability.

Silicate versus carbonate weathering in Iceland: New insights from Ca isotopes

NASA Astrophysics Data System (ADS)

Jacobson, Andrew D.; Grace Andrews, M.; Lehn, Gregory O.; Holmden, Chris

2015-04-01

Several studies have measured riverine fluxes of Ca and carbonate alkalinity in Iceland with the aim of quantifying the role of basalt weathering in the long-term carbon cycle. A major assumption is that all of the Ca and alkalinity originates from the dissolution of Ca-bearing silicate minerals, such as plagioclase and clinopyroxene. However, hydrothermal calcite occurs throughout Iceland, and even trace levels are expected to impact river geochemistry owing to the mineral's high solubility and fast dissolution rate. To test this hypothesis, we used a new, high-precision Ca isotope MC-TIMS method (δ44/40Ca; 2σSD = ± 0.04 ‰) to trace sources of Ca in Icelandic rivers. We report elemental and Ca isotope data for rivers, high- and low-temperature groundwater, basalt, hydrothermal calcite (including Iceland Spar), and stilbite and heulandite, which are two types of zeolites commonly formed during low-grade metamorphism of basalt. In agreement with previous research, we find that rivers have higher δ44/40Ca values than basalt, with a maximum difference of ∼0.40‰. This difference may reflect isotope fractionation in the weathering zone, i.e., preferential uptake of 40Ca during clay mineral formation, adsorption, and other geochemical processes that cycle Ca. However, calcite δ44/40Ca values are also up to ∼0.40‰ higher than bedrock values, and on a diagram of δ44/40Ca versus Sr/Ca, nearly all waters plot within a plausible mixing domain bounded by the measured compositions of basalt and calcite, with glacial rivers plotting closer to calcite than non-glacial rivers. Calcite and heulandite form during hydrothermal alteration of basalt in the deep lava pile and often occur together in metabasalts now exposed at the surface. Because heulandite δ44/40Ca values are ∼1-2‰ lower than basalt, we suggest that 40Ca uptake by heudlandite explains the relatively high δ44/40Ca values of calcite and that calcite weathering in turn elevates riverine δ44/40Ca values. High mechanical erosion rates are known to facilitate the exposure and weathering of calcite, which explains the isotopic contrast between glacial and non-glacial watersheds. Using a mixing model, we find that calcite weathering provides ∼0-65% of the Ca in non-glacial rivers and ∼25-90% of the Ca in glacial rivers, with silicate weathering providing the remainder. Icelandic hydrothermal calcite contains mantle carbon. Noting that zeolite facies metamorphism and hydrothermal fluid circulation are ubiquitous characteristics of basaltic eruptions and assuming that hydrothermal calcite in other basaltic settings also contains mantle carbon, we suggest that the contribution of basalt weathering to long-term CO2 drawdown and climate regulation may be less significant than previously realized.

SU(2) x U(1) vacuum and the Centauro events

NASA Technical Reports Server (NTRS)

Kazanas, D.; Balasubrahmanyan, V. K.; Streitmatter, R. E.

1985-01-01

It is proposed that the fireballs invoked to explain the Centauro events are bubbles of a metastable superdense state of nuclear matter, created in high energy (E approximately 10 to the 15th power eV) cosmic ray collisions at the top of the atmosphere. If these bubbles are created with a Lorentz factor gamma approximately equals 10 at their CM frame, the objections against the origin of these events in cosmic ray interactions are overcome. A relationship then between their lifetime, tau, and the threshold energy for bubble formation, E sub th, appears to be insensitive to the value of tau and always close to E sub th approximately 10 to 15th power eV. Finally it is speculated that these bubbles might be manifestations of the SU(2) x U(1) false vacuum excited in these collisions. The absence of in the Centauro events is then explained by the decay modes of these excitations.

Heterogeneous reactions in aircraft gas turbine engines

NASA Astrophysics Data System (ADS)

Brown, R. C.; Miake-Lye, R. C.; Lukachko, S. P.; Waitz, I. A.

2002-05-01

One-dimensional flow models and unity probability heterogeneous rate parameters are used to estimate the maximum effect of heterogeneous reactions on trace species evolution in aircraft gas turbines. The analysis includes reactions on soot particulates and turbine/nozzle material surfaces. Results for a representative advanced subsonic engine indicate the net change in reactant mixing ratios due to heterogeneous reactions is <10-6 for O2, CO2, and H2O, and <10-10 for minor combustion products such as SO2 and NO2. The change in the mixing ratios relative to the initial values is <0.01%. Since these estimates are based on heterogeneous reaction probabilities of unity, the actual changes will be even lower. Thus, heterogeneous chemistry within the engine cannot explain the high conversion of SO2 to SO3 which some wake models require to explain the observed levels of volatile aerosols. Furthermore, turbine heterogeneous processes will not effect exhaust NOx or NOy levels.

Maternal personal resources and children's socioemotional and behavioral adjustment.

PubMed

Al-Yagon, Michal

2008-09-01

The study examined the role of three maternal personal resources [sense of coherence (SOC), attachment style, and social/emotional feelings of loneliness] in explaining children's socioemotional adjustment (self-rated loneliness and SOC, and mother-rated child behavior) and children's (self-rated) secure attachment. The sample included 58 mother-child dyads (27 boys and 31 girls) aged 8-11 years. Preliminary analyses indicated significant group differences between mothers with high or low scores on the two subscales of the attachment scale (i.e., avoidance and anxiety), on their SOC, and their social/emotional loneliness. Findings revealed that maternal SOC significantly contributed to all child socioemotional adjustment measures and attachment scores. In addition, the current findings demonstrated the role of maternal anxious attachment in explaining children's externalizing behaviors. Discussion focused on the unique value of maternal characteristics for understanding social and emotional adjustment among school-age children.

'Individualism-collectivism' as an explanatory device for mental illness stigma.

PubMed

Papadopoulos, Chris; Foster, John; Caldwell, Kay

2013-06-01

The aim of this study is investigate whether the cross-cultural value paradigm 'individualism-collectivism' is a useful explanatory model for mental illness stigma on a cultural level. Using snowball sampling, a quantitative questionnaire survey of 305 individuals from four UK-based cultural groups (white-English, American, Greek/Greek Cypriot, and Chinese) was carried out. The questionnaire included the 'Community Attitudes to Mental Illness scale' and the 'vertical-horizontal individualism-collectivism scale'. The results revealed that the more stigmatizing a culture's mental illness attitudes are, the more likely collectivism effectively explains these attitudes. In contrast, the more positive a culture's mental illness attitudes, the more likely individualism effectively explains attitudes. We conclude that a consideration of the individualism-collectivism paradigm should be included in any future research aiming to provide a holistic understanding of the causes of mental illness stigma, particularly when the cultures stigmatization levels are particularly high or low.

Investigation on the porosity of zeolite NU-88 by means of positron annihilation lifetime spectroscopy

NASA Astrophysics Data System (ADS)

Consolati, G.; Mariani, M.; Millini, R.; Quasso, F.

2009-08-01

Seven well characterized zeolites were investigated by positron annihilation lifetime spectroscopy. The lifetime spectra were analysed in four discrete components. The third one was associated with ortho-positronium annihilation in the channels, framed in terms of infinite cylinders. Differences between the radii determined from the positron annihilation technique and X-ray diffraction data were found and explained in terms of the physical structure of the channel. An analogous study on a high-silica NU-88 zeolite gave a value of 0.33 nm for the corresponding radius, in agreement with Ar and N 2 adsorption data as well as with the catalytic behaviour of this zeolite in several acid catalyzed reactions. The longest lifetime component in NU-88 reveals the existence of mesopores, with average radius of about 1.8 nm, which could explain the importance of hydrogen transfer reactions in this zeolite.

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

Onić, D.; Urošević, D.; Leahy, D., E-mail: donic@matf.bg.ac.rs

Recent observations of the microwave sky, by space telescopes such as the Wilkinson Microwave Anisotropy Probe and Planck , have opened a new window into the analysis of continuum emission from supernova remnants (SNRs). In this paper, different emission models that can explain the characteristic shape of currently known integrated radio/microwave continuum spectrum of the Galactic SNR IC 443 are tested and discussed. In particular, the possibility is emphasized that the slight bump in the integrated continuum of this remnant around 20–70 GHz is genuine and that it can be explained by the contribution of an additional emission mechanism suchmore » as spinning dust. We find that adding a spinning dust component to the emission model improves the fit of the integrated spectrum of this SNR while at the same time preserving the physically probable parameter values. Finally, models that include the high-frequency synchrotron bending of the IC 443 radio to microwave continuum are favored.« less

Heritability of somatotype components: a multivariate analysis.

PubMed

Peeters, M W; Thomis, M A; Loos, R J F; Derom, C A; Fagard, R; Claessens, A L; Vlietinck, R F; Beunen, G P

2007-08-01

To study the genetic and environmental determination of variation in Heath-Carter somatotype (ST) components (endomorphy, mesomorphy and ectomorphy). Multivariate path analysis on twin data. Eight hundred and three members of 424 adult Flemish twin pairs (18-34 years of age). The results indicate the significance of sex differences and the significance of the covariation between the three ST components. After age-regression, variation of the population in ST components and their covariation is explained by additive genetic sources of variance (A), shared (familial) environment (C) and unique environment (E). In men, additive genetic sources of variance explain 28.0% (CI 8.7-50.8%), 86.3% (71.6-90.2%) and 66.5% (37.4-85.1%) for endomorphy, mesomorphy and ectomorphy, respectively. For women, corresponding values are 32.3% (8.9-55.6%), 82.0% (67.7-87.7%) and 70.1% (48.9-81.8%). For all components in men and women, more than 70% of the total variation was explained by sources of variance shared between the three components, emphasising the importance of analysing the ST in a multivariate way. The findings suggest that the high heritabilities for mesomorphy and ectomorphy reported in earlier twin studies in adolescence are maintained in adulthood. For endomorphy, which represents a relative measure of subcutaneous adipose tissue, however, the results suggest heritability may be considerably lower than most values reported in earlier studies on adolescent twins. The heritability is also lower than values reported for, for example, body mass index (BMI), which next to the weight of organs and adipose tissue also includes muscle and bone tissue. Considering the differences in heritability between musculoskeletal robustness (mesomorphy) and subcutaneous adipose tissue (endomorphy) it may be questioned whether studying the genetics of BMI will eventually lead to a better understanding of the genetics of fatness, obesity and overweight.

Adolescent-Perceived Parent and Teacher Overestimation of Mathematics Ability: Developmental Implications for Students' Mathematics Task Values

ERIC Educational Resources Information Center

Gniewosz, Burkhard; Watt, Helen M. G.

2017-01-01

This study examines whether and how student-perceived parents' and teachers' overestimation of students' own perceived mathematical ability can explain trajectories for adolescents' mathematical task values (intrinsic and utility) controlling for measured achievement, following expectancy-value and self-determination theories. Longitudinal data…

Administrating Transnational Education: A Cross-Cultural Application of Hodgkinson's Values Paradigm

ERIC Educational Resources Information Center

Eldridge, Kaye; Cranston, Neil

2009-01-01

This article reports on an exploratory study which employed Hodgkinson's values paradigm as an analytical tool for explaining how administrators of transnational education programmes understand national cultural values to affect their work and working environment. In particular, interviews with managers responsible for Australia's provision of…

The Use of Cronbach's Alpha When Developing and Reporting Research Instruments in Science Education

NASA Astrophysics Data System (ADS)

Taber, Keith S.

2017-06-01

Cronbach's alpha is a statistic commonly quoted by authors to demonstrate that tests and scales that have been constructed or adopted for research projects are fit for purpose. Cronbach's alpha is regularly adopted in studies in science education: it was referred to in 69 different papers published in 4 leading science education journals in a single year (2015)—usually as a measure of reliability. This article explores how this statistic is used in reporting science education research and what it represents. Authors often cite alpha values with little commentary to explain why they feel this statistic is relevant and seldom interpret the result for readers beyond citing an arbitrary threshold for an acceptable value. Those authors who do offer readers qualitative descriptors interpreting alpha values adopt a diverse and seemingly arbitrary terminology. More seriously, illustrative examples from the science education literature demonstrate that alpha may be acceptable even when there are recognised problems with the scales concerned. Alpha is also sometimes inappropriately used to claim an instrument is unidimensional. It is argued that a high value of alpha offers limited evidence of the reliability of a research instrument, and that indeed a very high value may actually be undesirable when developing a test of scientific knowledge or understanding. Guidance is offered to authors reporting, and readers evaluating, studies that present Cronbach's alpha statistic as evidence of instrument quality.

Os-186 and Os-187 Enrichments and High-He-3/He-4 sources in the Earth's Mantle: Evidence from Icelandic Picrites

NASA Technical Reports Server (NTRS)

Brandon, Alan D.; Graham, David W.; Waight, Tod; Gautason, Bjarni

2007-01-01

Picrites from the neovolcanic zones in Iceland display a range in Os-187/Os-188O from 0.1297 to 0.1381 ((gamma)Os = 0.0 to 6.5) and uniform Os-186/Os-188 of 0.1198375+/-32 (2 (sigma)). The value for Os-186/Os-188 is within uncertainty of the present-day value for the primitive upper mantle of 0.1198398+/-16. These Os isotope systematics are best explained by ancient recycled crust or melt enrichment in the mantle source region. If so, then the coupled enrichments displayed in Os-186/Os-188 and Os-187/Os-188 from lavas of other plume systems must result from an independent process, the most viable candidate at present remains core-mantle interaction. While some plumes with high He-3/He-4, such as Hawaii, appear to have been subjected to detectable addition of Os (and possibly He) from the outer core, others such as Iceland do not. A positive correlation between Os-187/Os-188 and He-3/He-4 from 9.6 to 19 RA in Iceland picrites is best modeled as mixtures of 500 Ma or older ancient recycled crust mixed with primitive mantle, creating a hybrid source region that subsequently mixes with the convecting MORB mantle during ascent and melting. This multistage mechanism to explain these isotope systematics is consistent with ancient recycled crust juxtaposed with more primitive, relatively He-rich mantle, in convective isolation from the upper mantle, most likely in the lowermost mantle. This is inconsistent with models that propose random mixing between heterogeneities in the convecting upper mantle as a mechanism to explain the observed isotopic variation in oceanic lavas or models that produce a high He-3/He-4 signature in melt depleted and strongly outgassed, He-poor mantle. Instead these systematics require a deep mantle source to explain the 3He/4He signature in Iceland lavas. The He-3/He-4 of lavas derived from the Iceland plume changed over time, from a maximum of 50 RA at 60 Ma, to approximately 25-27 RA at present. The changes are coupled with distinct compositional gaps between the different aged lavas when H-3/He-4 is plotted versus various geochemical parameters such as Nd-143/Nd-144 and La/Sm. These relationships can be interpreted as an increase in the proportion of ancient recycled crust in the upwelling plume over this time period.

What Drives Hydrogen Isotopic Variability Recorded by Biomarkers in Sediments of Lake Karakul, Pamir?

NASA Astrophysics Data System (ADS)

Aichner, B.; Mischke, S.; Pausata, F. S. R.; Werner, M.; Zhang, Q.; Heinecke, L.; Feakins, S. J.; Sachse, D.; Mahmoudov, Z.; Rajabov, I.

2017-12-01

Central Asia is a climate sensitive region located at the boundary of large scale atmospheric circulation systems. To examine glacial to interglacial hydrological changes in the region, we analysed the hydrogen isotopic composition (δD values) of n-alkanes in a 30-ka record from Lake Karakul, eastern Pamir (altitude: 3,915m, MAT: -3.9 °C, MAP: 82 mm). δD values of both aquatic and terrestrial compounds showed distinct trends throughout the studied time interval, with generally higher values during the glacial and lower values during the Holocene, and variability of up to 60‰. In particular shifts towards higher δD values were observed for aquatic biomarkers at ca. 30, 27, and 15 ka BP. Temperature and precipitation effects alone cannot explain the higher δD values during the glacial and the large isotopic amplitudes. To explain these observations we conducted a set of experiments using atmospheric models with embedded isotope modules (CAM3iso- and ECHAM5-wiso). We assume that terrestrial n-alkanes mainly record the isotopic signature of summer precipitation within the lower elevated parts of the Karakul Basin. Based on the model output we hypothesize that shifts between local and more distant vapour sources are the reason behind the trends within isotopic data. Data derived from aquatic biomarkers are more difficult to explain due to multiple influencing factors on δD of the lake water. Assuming that the lake water integrates an annual isotopic signal from the whole lake catchment, we suggest that a change in precipitation seasonality drives the large variability of hydrogen isotopic values. This is in agreement with the models, which suggest reduced winter (more negative δD) and slightly higher summer precipitation (more positive δD) during the glacial compared to the Holocene. Consequently, a net-increase of isotopically enriched inflow into the lake could explain the three distinct shifts towards higher δD values. Expansion of terrestrial vegetation, indicated by increasing biomarker concentrations, during these periods is another indicator for wetter summers in an arid environment. We conclude that δD values of terrestrial compounds reflect major shifts of vapour sources which are driven by insolation, while aquatic biomarkers are additionally influenced by changes of precipitation seasonality.

Hydrometeorological daily recharge assessment model (DREAM) for the Western Mountain Aquifer, Israel: Model application and effects of temporal patterns

NASA Astrophysics Data System (ADS)

Sheffer, N. A.; Dafny, E.; Gvirtzman, H.; Navon, S.; Frumkin, A.; Morin, E.

2010-05-01

Recharge is a critical issue for water management. Recharge assessment and the factors affecting recharge are of scientific and practical importance. The purpose of this study was to develop a daily recharge assessment model (DREAM) on the basis of a water balance principle with input from conventional and generally available precipitation and evaporation data and demonstrate the application of this model to recharge estimation in the Western Mountain Aquifer (WMA) in Israel. The WMA (area 13,000 km2) is a karst aquifer that supplies 360-400 Mm3 yr-1 of freshwater, which constitutes 20% of Israel's freshwater and is highly vulnerable to climate variability and change. DREAM was linked to a groundwater flow model (FEFLOW) to simulate monthly hydraulic heads and spring flows. The models were calibrated for 1987-2002 and validated for 2003-2007, yielding high agreement between calculated and measured values (R2 = 0.95; relative root-mean-square error = 4.8%; relative bias = 1.04). DREAM allows insights into the effect of intra-annual precipitation distribution factors on recharge. Although annual precipitation amount explains ˜70% of the variability in simulated recharge, analyses with DREAM indicate that the rainy season length is an important factor controlling recharge. Years with similar annual precipitation produce different recharge values as a result of temporal distribution throughout the rainy season. An experiment with a synthetic data set exhibits similar results, explaining ˜90% of the recharge variability. DREAM represents significant improvement over previous recharge estimation techniques in this region by providing near-real-time recharge estimates that can be used to predict the impact of climate variability on groundwater resources at high temporal and spatial resolution.

Evidence for increased latent heat transport during the Cretaceous (Albian) greenhouse warming

USGS Publications Warehouse

Ufnar, David F.; Gonzalez, Luis A.; Ludvigson, Greg A.; Brenner, Richard L.; Witzke, B.J.

2004-01-01

Quantitative estimates of increased heat transfer by atmospheric H 2O vapor during the Albian greenhouse warming suggest that the intensified hydrologic cycle played a greater role in warming high latitudes than at present and thus represents a viable alternative to oceanic heat transport. Sphaerosiderite ??18O values in paleosols of the North American Cretaceous Western Interior Basin are a proxy for meteoric ??18O values, and mass-balance modeling results suggest that Albian precipitation rates exceeded modern rates at both mid and high latitudes. Comparison of modeled Albian and modern precipitation minus evaporation values suggests amplification of the Albian moisture deficit in the tropics and moisture surplus in the mid to high latitudes. The tropical moisture deficit represents an average heat loss of ???75 W/m2 at 10??N paleolatitude (at present, 21 W/m2). The increased precipitation at higher latitudes implies an average heat gain of ???83 W/m2 at 45??N (at present, 23 W/m2) and of 19 W/m2 at 75??N (at present, 4 W/m2). These estimates of increased poleward heat transfer by H2O vapor during the Albian may help to explain the reduced equator-to-pole temperature gradients. ?? 2004 Geological Society of America.

Stable carbon isotopes of HCO3- in oil-field waters-implications for the origin of CO2

USGS Publications Warehouse

Carothers, W.W.; Kharaka, Y.K.

1980-01-01

The ??13C values of dissolved HCO3- in 75 water samples from 15 oil and gas fields (San Joaquin Valley, Calif., and the Houston-Galveston and Corpus Christi areas of Texas) were determined to study the sources of CO2 of the dissolved species and carbonate cements that modify the porosity and permeability of many petroleum reservoir rocks. The reservoir rocks are sandstones which range in age from Eocene through Miocene. The ??13C values of total HCO3- indicate that the carbon in the dissolved carbonate species and carbonate cements is mainly of organic origin. The range of ??13C values for the HCO3- of these waters is -20-28 per mil relative to PDB. This wide range of ??13C values is explained by three mechanisms. Microbiological degradation of organic matter appears to be the dominant process controlling the extremely low and high ??13C values of HCO3- in the shallow production zones where the subsurface temperatures are less than 80??C. The extremely low ??13C values (< -10 per mil) are obtained in waters where concentrations of SO42- are more than 25 mg/l and probably result from the degradation of organic acid anions by sulfate-reducing bacteria (SO42- + CH3COO- ??? 2HCO3- + HS-). The high ??13C values probably result from the degradation of these anions by methanogenic bacteria (CH3COO- + H2O ai HCO3- + CH4). Thermal decarboxylation of short-chain aliphatic acid anions (principally acetate) to produce CO2 and CH4 is probably the major source of CO2 for production zones with subsurface temperatures greater than 80??C. The ??13C values of HCO3- for waters from zones with temperatures greater than 100??C result from isotopic equilibration between CO2 and CH4. At these high temperatures, ??13C values of HCO3- decrease with increasing temperatures and decreasing concentrations of these acid anions. ?? 1980.

Time-resolved mapping of water diffusion coefficients in a working soft actuator device.

PubMed

Naji, Leila; Chudek, John A; Baker, Richard T

2008-08-14

Diffusion-weighted imaging was employed to spatially map the distribution of the diffusion coefficient of water, D, in bare, water-soaked, Li(+)-exchanged, cast Nafion and in an ionic polymer-metal composite (IPMC) soft actuator element, prepared from this bare Nafion by impregnation with Pt electrodes. D was evaluated in two orthogonal directions: along one of the long dimensions of the sample (Dx) and through its thickness (Dz). D-maps of the IPMC element were obtained both in the absence of an applied potential and in situ during the application of a 3 V dc potential across the thickness of the sample. In the bare Nafion, D-maps showed uniform values of both Dx and Dz of about 6 x 10 (-10) m(2) s(-1). In the IPMC two effects were observed: (i) D at the electroded surfaces of the IPMC was higher than at the center of the sample; (ii) this difference was much greater in Dz than in Dx . Both effects were explained by the influence of the impregnated Pt electrodes on polymer structure. The D-maps in the electrochemical measurements showed high values of D (up to 8 x 10(-10) m(2) s(-1)) at the cathode and low values (from 1 x 10(-10) m(2) s(-1)) at the anode. This was explained in terms of the effect on the Nafion nanostructure of the forced electro-migration of Li(H2O)x(+) species toward the cathode.

Differentiated Success: Combining Theories to Explain Learning

ERIC Educational Resources Information Center

Jorgensen, Robyn; Larkin, Kevin

2015-01-01

This paper explores the value of different paradigms to explain dispositions towards mathematics among primary school students from different social backgrounds. As part of a larger project designed to elicit students' thinking and attitudes towards mathematics, we seek to develop an explanatory model for the socially-differentiated outcomes in…

Morality, values, traditional bullying, and cyberbullying in adolescence.

PubMed

Menesini, Ersilia; Nocentini, Annalaura; Camodeca, Marina

2013-03-01

The aim of the present study was to investigate moral aspects and human values in traditional bullying and cyberbullying, in order to detect differences between the two types of bullying and to test the role of immoral and disengaged behaviours in mediating the relationships between personal values and involvement in bullying. Sample comprised 390 adolescents aged 14-18, balanced for gender, attending different high schools. Traditional and cyberbullying were detected by means of two self-report measures, while the Portrait Values Questionnaire was used to assess 10 values in four dimensions according to the value system model by Schwartz (1992): self-trascendence, self-enhancement, openness to change, and conservation. Finally, immoral and disengaged behaviours were assessed by means of five items about behavioural and personal aspects salient for morality. Results showed that, irrespective of gender, self-enhancement and self-trascendence moderately predicted cyber and traditional bullying, respectively, while immoral and disengaged behaviours predicted both. Indirect effects showed that self-enhancement and openness to change predicted both forms of bullying through immoral behaviour. Results are discussed in terms of similarities and differences between cyber and traditional bullying and with attention to the central role of morality in explaining bullying nature. © 2011 The British Psychological Society.

Adding Value by Hospital Real Estate: An Exploration of Dutch Practice.

PubMed

van der Zwart, Johan; van der Voordt, Theo J M

2016-01-01

To explore how hospital real estate can add value to the healthcare organization, which values are prioritized in practice, and why. Dutch healthcare organizations are self-responsible for the costs and benefits of their accommodation. Meanwhile, a lively debate is going on about possible added values of corporate and public real estate in the fields of corporate real estate management and facility management. This article connects both worlds and compares insights from literature with experiences from practice. Added values extracted from literature have been discussed with 15 chief executive officers and project leaders of recently newly built hospitals in the Netherlands. Interviewees were asked (1) which values are included in the design and management of their hospital and why, (2) to prioritize most important values from a list of nine predefined values, and (3) to explain how the chosen real estate decisions are supposed to support organizational objectives. Stimulating innovation, user satisfaction, and improving organizational culture are most highly valued, followed by improving productivity, reducing building costs, and creating building flexibility. Image, risk control, and financing possibilities got lower rankings. The findings have been used to develop a value-impact matrix that connects nine values to various stakeholders and possible interventions. The findings and the value-impact matrix can make different stakeholders aware of many possible added values of hospital real estate, potential synergy and conflicts between different values, and how to steer on value add in different phases of the life cycle. © The Author(s) 2015.

Structure of the midcontinent basement. Topography, gravity, seismic, and remote sensing

NASA Technical Reports Server (NTRS)

Guinness, E. A.; Strebeck, J. W.; Arvidson, R. E.; Scholz, K.; Davies, G. F.

1981-01-01

Some 600,000 discrete Bouguer gravity estimates of the continental United States were spatially filtered to produce a continuous tone image. The filtered data were also digitally painted in color coded form onto a shaded relief map. The resultant image is a colored shaded relief map where the hue and saturation of a given image element is controlled by the value of the Bouguer anomaly. Major structural features (e.g., midcontinent gravity high) are readily discernible in these data, as are a number of subtle and previously unrecognized features. A linear gravity low that is approximately 120 to 150 km wide extends from southeastern Nebraska, at a break in the midcontinent gravity high, through the Ozark Plateau, and across the Mississippi embayment. The low is also aligned with the Lewis and Clark lineament (Montana to Washington), forming a linear feature of approximately 2800 km in length. In southeastern Missouri the gravity low has an amplitude of 30 milligals, a value that is too high to be explained by simple valley fill by sedimentary rocks.

Thermal Quenching of Photoluminescence in ZnO and GaN

NASA Astrophysics Data System (ADS)

Albarakati, Nahla Mubarak

Investigation of the thermal quenching of photoluminescence (PL) in semiconductors provides valuable information on identity and characteristics of point defects in these materials, which helps to better understand and improve the properties of semiconductor materials and devices. Abrupt and tunable thermal quenching (ATQ) of PL is a relatively new phenomenon with an unusual behavior of PL. This mechanism was able to explain what a traditional model failed to explain. Usually, in traditional model used to explain "normal" quenching, the slope of PL quenching in the Arrhenius plot determines the ionization energy of the defect causing the PL band. However, in abrupt quenching when the intensity of PL decreases by several orders of magnitude within a small range of temperature, the slope in the Arrhenius plot has no relation to the ionization energy of any defect. It is not known a priori if the thermal quenching of a particular PL band is normal or abrupt and tunable. Studying new cases of unusual thermal quenching, classifying and explaining them helps to predict new cases and understand deeper the ATQ mechanism of PL thermal quenching. Very few examples of abrupt and tunable quenching of PL in semiconductors can be found in literature. The abrupt and tunable thermal quenching, reported here for the first time for high-resistivity ZnO, provides an evidence to settle the dispute concerning the energy position of the Li Zn acceptor. In high-resistivity GaN samples, the common PL bands related to defects are the yellow luminescence (YL) band and a broad band in the blue spectral region (BL2). In this work, we report for the first time the observation of abrupt and tunable thermal quenching of the YL band in GaN. The activation energies for the YL and BL2 bands calculated through the new mechanism show agreement with the reported values. From this study we predict that the ATQ phenomenon is quite common for high-resistivity semiconductors.

Ion conduction in the KcsA potassium channel analyzed with a minimal kinetic model.

PubMed

Mafé, Salvador; Pellicer, Julio

2005-02-01

We use a model by Nelson to study the current-voltage and conductance-concentration curves of bacterial potassium channel KcsA without assuming rapid ion translocation. Ion association to the channel filter is rate controlling at low concentrations, but dissociation and transport in the filter can limit conduction at high concentration for ions other than K+. The absolute values of the effective rate constants are tentative but the relative changes in these constants needed to qualitatively explain the experiments should be of significance.

Lateral variations in lower mantle seismic velocity

NASA Technical Reports Server (NTRS)

Duffy, Thomas S.; Ahrens, Thomas J.

1992-01-01

To obtain a theoretical model which provides a rationale for the observed high values of velocity variations, the effect of a 0.1 to 0.2 percent partially molten volatile-rich material in various geometries which are heterogeneously dispersed in the lower mantle is examined. Data obtained indicate that, depending on aspect ratio and geometry, 0.1-0.2 percent partial melting in conjunction with about 100 K thermal anomalies can explain the seismic variations provided the compressibility of the melt differs by less than about 20 percent from the surrounding solid.

Phase equilibria in a system of aqueous arginine with an octane solution of sulfonic acid

NASA Astrophysics Data System (ADS)

Kuvaeva, Z. I.; Koval'chuk, I. V.; Vodop'yanova, L. A.; Soldatov, V. S.

2013-05-01

The extraction of arginine (Arg) from aqueous salt (0.1 M NaCl) solutions with a sulfo extractant in a wide range of pH values and amino acid concentrations was studied. The 0.1 M solution of dinonylnaphthalenesulfonic acid (HD) in octane was used as an extractant. The degree of extraction was found to be high at pH 0.8-9.0. This can be explained by the effect of additional intermolecular interactions in the extractant phase involving the guanidine group of Arg.

Self-assessment of clinical nurse mentors as dimensions of professional development and the capability of developing ethical values at nursing students: A correlational research study.

PubMed

Skela-Savič, Brigita; Kiger, Alice

2015-10-01

Providing adequate training for mentors, fostering a positive mentorship culture and establishing the necessary operational procedures for ensuring mentorship quality are the keys to effective clinical mentoring of nursing students. The purpose of the research was to explain different dimensions of clinical mentors' professional development and their capability of developing ethical values in nursing students. A non-experimental quantitative research design was employed. Data were collected by means of a questionnaire administered to the population of clinical mentors (N=143). The total number of questions was 36. Descriptive statistics were used, and bivariate analysis, factor analysis, correlation analysis and linear regression analysis were performed. The professional development of clinical nurse mentors was explained (R(2)=0.256) by career advancement (p=0.000), research and learning (p=0.024) and having a career development plan (p=0.043). Increased professional self-confidence (R(2)=0.188) was explained by career advancement (p=0.000) and the time engaged in record keeping (p=0.028). Responsibility for the development of ethical values in nursing students (R(2)=0.145) was explained by the respondents' level of education (p=0.020) and research and learning (p=0.024). Applying ethical principles and norms into practice (R(2)=0.212) was explained by self-assessed knowledge in ethics (p=0.037) and research and learning (p=0.044). Clinical nurse mentors tended to lack a career development plan, had low work time spent on research and insufficiently participated in education and training activities, which turned out to be significant explanatory factors of their professional development and their capability of developing ethical values in nursing students. The research showed that nursing and higher education managers often failed to assume responsibility for the professional development of clinical nurse mentors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relational values resonate broadly and differently than intrinsic or instrumental values, or the New Ecological Paradigm.

PubMed

Klain, Sarah C; Olmsted, Paige; Chan, Kai M A; Satterfield, Terre

2017-01-01

Value orientations used to explain or justify conservation have been rooted in arguments about how much and in what context to emphasize the intrinsic versus instrumental value of nature. Equally prominent are characterizations of beliefs known as the New Ecological Paradigm (NEP), often used to help explain pro-environmental behaviour. A recent alternative to these positions has been identified as 'relational value'-broadly, values linking people and ecosystems via tangible and intangible relationships to nature as well as the principles, virtues and notions of a good life that may accompany these. This paper examines whether relational values are distinct from other value orientation and have potential to alleviate the intrinsic-instrumental debate. To test this possibility, we sought to operationalize the construct-relational values-by developing six relational statements. We ask: 1) Do the individual statements used to characterize relational values demonstrate internal coherence as either a single or multi-dimensional construct? 2) Do relational value statements (including those strongly stated) resonate with diverse populations? 3) Do people respond to relational value statements in a consistently different way than NEP scale statements? Data for this work is drawn from an online panel of residents of northeastern US (n = 400), as well as a sample of Costa Rican farmers (n = 253) and tourists in Costa Rica (n = 260). Results indicate relational values are distinct as a construct when compared to the NEP.

The oxygen isotope composition of Karoo and Etendeka picrites: High δ18O mantle or crustal contamination?

NASA Astrophysics Data System (ADS)

Harris, Chris; le Roux, Petrus; Cochrane, Ryan; Martin, Laure; Duncan, Andrew R.; Marsh, Julian S.; le Roex, Anton P.; Class, Cornelia

2015-07-01

Oxygen isotope compositions of Karoo and Etendeka large igneous province (LIP) picrites and picrite basalts are presented to constrain the effects of crustal contamination versus mantle source variation. Olivine and orthopyroxene phenocrysts from lavas and dykes (Mg# 64-80) from the Tuli and Mwenezi (Nuanetsi) regions of the ca 180 Ma Karoo LIP have δ18O values that range from 6.0 to 6.7 ‰. They appear to have crystallized from magmas having δ18O values about 1-1.5 ‰ higher than expected in an entirely mantle-derived magma. Olivines from picrite and picrite basalt dykes from the ca 135 Ma Etendeka LIP of Namibia and Karoo-age picrite dykes from Dronning Maud Land, Antarctica, do not have such elevated δ18O values. A range of δ18O values from 4.9 to 6.0 ‰, and good correlations between δ18O value and Sr, Nd and Pb isotope ratios for the Etendeka picrites are consistent with previously proposed models of crustal contamination. Explanations for the high δ18O values in Tuli/Mwenezi picrites are limited to (1) alteration, (2) crustal contamination, and (3) derivation from mantle with an abnormally high δ18O. Previously, a variety of models that range from crustal contamination to derivation from the `enriched' mantle lithosphere have been suggested to explain high concentrations of incompatible elements such as K, and average ɛNd and ɛSr values of -8 and +16 in Mwenezi (Nuanetsi) picrites. However, the primitive character of the magmas (Mg# 73), combined with the lack of correlation between δ18O values and radiogenic isotopic compositions, MgO content, or Mg# is inconsistent with crustal contamination. Thus, an 18O-enriched mantle source having high incompatible trace element concentration and enriched radiogenic isotope composition is indicated. High δ18O values are accompanied by negative Nb and Ta anomalies, consistent with the involvement of the mantle lithosphere, whereas the high δ18O themselves are consistent with an eclogitic source. Magma δ18O values about 1 ‰ higher than expected for mantle-derived magma are also a feature of the Bushveld mafic and ultramafic magmas, and the possibility exists that a long-lived 18O-enriched mantle source has existed beneath southern Africa. A mixed eclogite peridotite source could have developed by emplacement of oceanic lithosphere into the cratonic keel during Archaean subduction.

Dynamic Divisive Normalization Predicts Time-Varying Value Coding in Decision-Related Circuits

PubMed Central

LoFaro, Thomas; Webb, Ryan; Glimcher, Paul W.

2014-01-01

Normalization is a widespread neural computation, mediating divisive gain control in sensory processing and implementing a context-dependent value code in decision-related frontal and parietal cortices. Although decision-making is a dynamic process with complex temporal characteristics, most models of normalization are time-independent and little is known about the dynamic interaction of normalization and choice. Here, we show that a simple differential equation model of normalization explains the characteristic phasic-sustained pattern of cortical decision activity and predicts specific normalization dynamics: value coding during initial transients, time-varying value modulation, and delayed onset of contextual information. Empirically, we observe these predicted dynamics in saccade-related neurons in monkey lateral intraparietal cortex. Furthermore, such models naturally incorporate a time-weighted average of past activity, implementing an intrinsic reference-dependence in value coding. These results suggest that a single network mechanism can explain both transient and sustained decision activity, emphasizing the importance of a dynamic view of normalization in neural coding. PMID:25429145

Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides

PubMed Central

Kniss, Andrew R.; Coburn, Carl W.

2015-01-01

Various indicators of pesticide environmental risk have been proposed, and one of the most widely known and used is the environmental impact quotient (EIQ). The EIQ has been criticized by others in the past, but it continues to be used regularly in the weed science literature. The EIQ is typically considered an improvement over simply comparing the amount of herbicides applied by weight. Herbicides are treated differently compared to other pesticide groups when calculating the EIQ, and therefore, it is important to understand how different risk factors affect the EIQ for herbicides. The purpose of this work was to evaluate the suitability of the EIQ as an environmental indicator for herbicides. Simulation analysis was conducted to quantify relative sensitivity of the EIQ to changes in risk factors, and actual herbicide EIQ values were used to quantify the impact of herbicide application rate on the EIQ Field Use Rating. Herbicide use rate was highly correlated with the EIQ Field Use Rating (Spearman’s rho >0.96, P-value <0.001) for two herbicide datasets. Two important risk factors for herbicides, leaching and surface runoff potential, are included in the EIQ calculation but explain less than 1% of total variation in the EIQ. Plant surface half-life was the risk factor with the greatest relative influence on herbicide EIQ, explaining 26 to 28% of the total variation in EIQ for actual and simulated EIQ values, respectively. For herbicides, the plant surface half-life risk factor is assigned values without any supporting quantitative data, and can result in EIQ estimates that are contrary to quantitative risk estimates for some herbicides. In its current form, the EIQ is a poor measure of herbicide environmental impact. PMID:26121252

Quantitative Evaluation of the Environmental Impact Quotient (EIQ) for Comparing Herbicides.

PubMed

Kniss, Andrew R; Coburn, Carl W

2015-01-01

Various indicators of pesticide environmental risk have been proposed, and one of the most widely known and used is the environmental impact quotient (EIQ). The EIQ has been criticized by others in the past, but it continues to be used regularly in the weed science literature. The EIQ is typically considered an improvement over simply comparing the amount of herbicides applied by weight. Herbicides are treated differently compared to other pesticide groups when calculating the EIQ, and therefore, it is important to understand how different risk factors affect the EIQ for herbicides. The purpose of this work was to evaluate the suitability of the EIQ as an environmental indicator for herbicides. Simulation analysis was conducted to quantify relative sensitivity of the EIQ to changes in risk factors, and actual herbicide EIQ values were used to quantify the impact of herbicide application rate on the EIQ Field Use Rating. Herbicide use rate was highly correlated with the EIQ Field Use Rating (Spearman's rho >0.96, P-value <0.001) for two herbicide datasets. Two important risk factors for herbicides, leaching and surface runoff potential, are included in the EIQ calculation but explain less than 1% of total variation in the EIQ. Plant surface half-life was the risk factor with the greatest relative influence on herbicide EIQ, explaining 26 to 28% of the total variation in EIQ for actual and simulated EIQ values, respectively. For herbicides, the plant surface half-life risk factor is assigned values without any supporting quantitative data, and can result in EIQ estimates that are contrary to quantitative risk estimates for some herbicides. In its current form, the EIQ is a poor measure of herbicide environmental impact.

[Relation between species distribution of plant community and soil factors under grazing in alpine meadow].

PubMed

Niu, Yu Jie; Yang, Si Wei; Wang, Gui Zhen; Liu, Li; Du, Guo Zhen; Hua, Li Min

2017-12-01

The research selected the alpine meadow located in the northeastern margin of the Qinghai-Tibet Plateau to study the changes of vegetation community and soil properties under different grazing intensities, as well as the quantitative relation between the distribution patterns of plant species and the physical and chemical properties of soil. The results showed that the grazing caused the differentiation of the initial vegetation community with the dominant plants, Elymus nutans and Stipa grandis. In the plots with high and low grazing intensities, the dominant plants had changed to Kobresia humilis and Melissitus ruthenica, and E. nutans and Poa crymophila, respectively. With the increase of grazing intensity, the plant richness, importance value and biomass were significantly decreased. The sequence of plant species importance value in each plot against grazing intensity could be fitted by a logarithmic model. The number of required plant species was reduced while the importance value of the remaining plant species accounted for 50% of the importance value in the whole vegetation community. The available P, available K, soil compaction, soil water content, stable infiltration rate and large aggregate index were significantly changed with grazing intensity, however, the changes were different. The CCA ordination showed that the soil compaction was the key factor affecting the distribution pattern of the plant species under grazing. The variance decomposition indicated that the soil factors together explained 30.5% of the distribution of the plant species, in particular the soil physical properties alone explained 22.8% of the distribution of the plant species, which had the highest rate of contribution to the plant species distribution. The soil physical properties affected the distribution pattern of plant species on grazed alpine meadow.

Role of alkoxyl radicals on the fluorescein-based ORAC (Oxygen Radical Absorbance Capacity) assay.

PubMed

Dorta, E; Atala, E; Aspee, A; Speisky, H; Lissi, E; Lopez-Alarcon, C

2014-10-01

During the last decades the ORAC (Oxygen Radical Absorbance Capacity) assay has been widely employed to evaluate the in vitro antioxidant capacity of polyphenol-rich fruits, vegetables and beverages. The method employs fluorescein (FLH) as target molecule and AAPH (2,2'-azo-bis(2-amidinopropane)dihydrochloride) as the source of peroxyl radicals (ROO•). The protection of FLH, afforded by antioxidants (XH), is often characterized by kinetic profiles with clear lag times (LT), which are directly associated with the stoichiometry (n) of the XH-ROO• reaction. However, even for simple phenolic compounds, the LT measured imply large n values (defined as the number of ROO• moles trapped by each antioxidant molecule) which cannot be explained by a simple reaction mechanism. Nonetheless, they can be explained when considering the formation of alkoxyl radicals (RO•) from the recombination of two AAPH-derived ROO•. In the present work, we provide kinetic data showing that, in the zero order kinetic limit of FLH consumption, there is a low reaction rate incompatible with total trapping of ROO•. Thus, the consumption of FLH should be mostly related to its reaction with RO•. In addition, we present data regarding the assumption that in competitive measurements, the LT is due to efficient trapping of the ROO• by the added phenols, leading to high n values (1.7 to 23) for mono and polyphenols. These values are not in agreement with kinetic studies of the antioxidant consumption mediated by the presence of AAPH carried out by HPLC-DAD technique, which imply a competition by RO•. The results suggest that the use of FLH as probe at low concentrations give, for several antioxidants, ORAC values mainly related to their reaction towards RO• radicals instead of primary ROO•radicals. Copyright © 2014. Published by Elsevier Inc.

High-pressure optical studies on R-line fluorescence lifetime in Al2O3:V2+

NASA Astrophysics Data System (ADS)

Jovanić, Branislav R.; Radenković, Božidar; Despotović-Zrakić, Marijana; Bogdanović, Zorica; Barać, Dušan

2018-04-01

The effect of high hydrostatic pressure (up to 10.3 GPa) at room temperature on fluorescence lifetime τ for R line (2E→4A2 transition) in ruby Al2O3:V2+ was studied. The performed studies show the linear increase of τ with increasing pressure. At 10.3 GPa, τ is about 1.36 times higher than at ambient pressure. The obtained trend was explained by a model which considered the effect of pressure on τ through an induced change of line position, inter-ionic distance, compressibility, and molecular polarizability. A good agreement between the calculated and experimental values for τ was obtained.

Reduction of temperature rise in high-speed photography

NASA Technical Reports Server (NTRS)

Slater, Howard A.

1987-01-01

Information is provided on filtration with glass and infrared absorbing and reflecting filters. Glass and infrared filtration is a simple and effective method to reduce the radiation heat transfer associated with continuous high intensity tungsten lamps. The results of a filtration experiment are explained. The figures provide starting points for quantifying the effectiveness of various filters and associated light intensities. The combination of a spectrally selective reflector (hot or cold mirror) based on multilayer thin film principles and heat absorbing or infrared opaque glass results in the maximum reduction in temperature rise with a minimum of incident light loss. Use is recommended of a voltage regulator to further control temperature rise and incident light values.

Reduction of temperature rise in high-speed photography

NASA Technical Reports Server (NTRS)

Slater, Howard A.

1988-01-01

Information is provided on filtration with glass and infrared absorbing and reflecting filters. Glass and infrared filtration is a simple and effective method to reduce the radiation heat transfer associated with continuous high intensity tungsten lamps. The results of a filtration experiment are explained. The figures provide starting points for quantifying the effectiveness of various filters and associated light intensities. The combination of a spectrally selective reflector (hot or cold mirror) based on multilayer thin film principles and heat absorbing or infrared opaque glass results in the maximum reduction in temperature rise with a minimum of incident light loss. Use is recommended of a voltage regulator to further control temperature rise and incident light values.

Variations on an Expectancy-Value Model of Motivation in Science.

PubMed

DeBacker; Nelson

1999-04-01

Relationships among motivational variables from goal theory and expectancy-value theory were investigated in this correlational study of high school students. Self-report surveys of motivation in science were collected during biology classes from 69 males and 80 females. Outcome measures were effort, persistence, and achievement. Gender differences were noted in the pattern of zero-order correlations. Internal motivation variables were related to achievement in males but not females. Regression analyses indicated that the motivation variables explained large proportions of variance in the outcomes. However, the contribution of individual variables differed by gender. Most notable was perceived ability, which contributed significantly to predicting outcome measures for females but not males. Findings suggest that interventions may need to focus on different motivational aspects depending on gender. Copyright 1999 Academic Press.

Variability of PCB burden in 5 fish and sharks species of the French Mediterranean continental slope.

PubMed

Cresson, Pierre; Fabri, Marie Claire; Miralles, Françoise Marco; Dufour, Jean-Louis; Elleboode, Romain; Sevin, Karine; Mahé, Kelig; Bouchoucha, Marc

2016-05-01

Despite being generally located far from contamination sources, deep marine ecosystems are impacted by chemicals like PCB. The PCB contamination in five fish and shark species collected in the continental slope of the Gulf of Lions (NW Mediterranean Sea) was measured, with a special focus on intra- and interspecific variability and on the driving factors. Significant differences occurred between species. Higher values were measured in Scyliorhinus canicula, Galeus melastomus and Helicolenus dactylopterus and lower values in Phycis blennoides and Lepidorhombus boscii. These differences might be explained by specific abilities to accumulate and eliminate contaminant, mostly through cytochrome P450 pathway. Interindividual variation was also high and no correlation was observed between contamination and length, age or trophic level. Despite its major importance, actual bioaccumulation of PCB in deep fish is not as documented as in other marine ecosystems, calling for a better assessment of the factors driving individual bioaccumulation mechanisms and originating high variability in PCB contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

Barrier inhomogeneities and electronic transport of Pt contacts to relatively highly doped n-type 4H-SiC

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

Huang, Lingqin, E-mail: lqhuang@jsnu.edu.cn, E-mail: dwang121@dlut.edu.cn; Wang, Dejun, E-mail: lqhuang@jsnu.edu.cn, E-mail: dwang121@dlut.edu.cn

The barrier characteristics of Pt contacts to relatively highly doped (∼1 × 10{sup 18 }cm{sup −3}) 4H-SiC were investigated using current-voltage (I-V) and capacitance-voltage (C-V) measurements in the temperature range of 160–573 K. The barrier height and ideally factor estimated from the I-V characteristics based on the thermionic emission model are abnormally temperature-dependent, which can be explained by assuming the presence of a double Gaussian distribution (GD) of inhomogeneous barrier heights. However, in the low temperature region (160–323 K), the obtained mean barrier height according to GD is lower than the actual mean value from C-V measurement. The values of barrier height determined from themore » thermionic field emission model are well consistent with those from the C-V measurements, which suggest that the current transport process could be modified by electron tunneling at low temperatures.« less

Anisotropy Induced Switching Field Distribution in High-Density Patterned Media

NASA Astrophysics Data System (ADS)

Talapatra, A.; Mohanty, J.

We present here micromagnetic study of variation of switching field distribution (SFD) in a high-density patterned media as a function of magnetic anisotropy of the system. We consider the manifold effect of magnetic anisotropy in terms of its magnitude, tilt in anisotropy axis and random arrangements of magnetic islands with random anisotropy values. Our calculation shows that reduction in anisotropy causes linear decrease in coercivity because the anisotropy energy tries to align the spins along a preferred crystallographic direction. Tilt in anisotropy axis results in decrease in squareness of the hysteresis loop and hence facilitates switching. Finally, the experimental challenges like lithographic distribution of magnetic islands, their orientation, creation of defects, etc. demanded the distribution of anisotropy to be random along with random repetitions. We have explained that the range of anisotropy values and the number of bits with different anisotropy play a key role over SFD, whereas the position of the bits and their repetitions do not show a considerable contribution.

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb3Sn Superconductor Wires.

PubMed

Heald, Steve M; Tarantini, Chiara; Lee, Peter J; Brown, Michael D; Sung, ZuHawn; Ghosh, Arup K; Larbalestier, David C

2018-03-19

To meet critical current density, J c , targets for the Future Circular Collider (FCC), the planned replacement for the Large Hadron Collider (LHC), the high field performance of Nb 3 Sn must be improved, but champion J c values have remained static for the last 10 years. Making the A15 phase stoichiometric and enhancing the upper critical field H c2 by Ti or Ta dopants are the standard strategies for enhancing high field performance but detailed recent studies show that even the best modern wires have broad composition ranges. To assess whether further improvement might be possible, we employed Extended X-ray Absorption Fine Structure (EXAFS) to determine the lattice site location of dopants in modern high-performance Nb 3 Sn strands with J c values amongst the best so far achieved. Although Ti and Ta primarily occupy the Nb sites in the A15 structure, we also find significant Ta occupancy on the Sn site. These findings indicate that the best performing Ti-doped stand is strongly sub-stoichiometric in Sn and that antisite disorder likely explains its high average H c2 behavior. These new results suggest an important role for dopant and antisite disorder in minimizing superconducting property distributions and maximizing high field J c properties.

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb 3Sn Superconductor Wires

DOE PAGES

Heald, Steve M.; Tarantini, Chiara; Lee, Peter J.; ...

2018-03-19

To meet critical current density, Jc, targets for the Future Circular Collider (FCC), the planned replacement for the Large Hadron Collider (LHC), the high field performance of Nb 3Sn must be improved, but champion J c values have remained static for the last 10 years. Making the A15 phase stoichiometric and enhancing the upper critical field H c2 by Ti or Ta dopants are the standard strategies for enhancing high field performance but detailed recent studies show that even the best modern wires have broad composition ranges. To assess whether further improvement might be possible, we employed EXAFS to determinemore » the lattice site location of dopants in modern high-performance Nb 3Sn strands with J c values amongst the best so far achieved. Although Ti and Ta primarily occupy the Nb sites in the A15 structure, we also find significant Ta occupancy on the Sn site. These findings indicate that the best performing Ti-doped stand is strongly sub-stoichiometric in Sn and that antisite disorder likely explains its high average H c2 behavior. These new results suggest an important role for dopant and antisite disorder in minimizing superconducting property distributions and maximizing high field J c properties.« less

Evidence from EXAFS for Different Ta/Ti Site Occupancy in High Critical Current Density Nb 3Sn Superconductor Wires

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

Heald, Steve M.; Tarantini, Chiara; Lee, Peter J.

To meet critical current density, Jc, targets for the Future Circular Collider (FCC), the planned replacement for the Large Hadron Collider (LHC), the high field performance of Nb 3Sn must be improved, but champion J c values have remained static for the last 10 years. Making the A15 phase stoichiometric and enhancing the upper critical field H c2 by Ti or Ta dopants are the standard strategies for enhancing high field performance but detailed recent studies show that even the best modern wires have broad composition ranges. To assess whether further improvement might be possible, we employed EXAFS to determinemore » the lattice site location of dopants in modern high-performance Nb 3Sn strands with J c values amongst the best so far achieved. Although Ti and Ta primarily occupy the Nb sites in the A15 structure, we also find significant Ta occupancy on the Sn site. These findings indicate that the best performing Ti-doped stand is strongly sub-stoichiometric in Sn and that antisite disorder likely explains its high average H c2 behavior. These new results suggest an important role for dopant and antisite disorder in minimizing superconducting property distributions and maximizing high field J c properties.« less

The Perceived Value of Higher Education: The Voice of Chinese Students

ERIC Educational Resources Information Center

Lai, Linda S. L.; To, W. M.; Lung, Jane W. Y.; Lai, T. M.

2012-01-01

This paper describes an exploratory study on the perceived value of higher education by Chinese students in Macao SAR, Guangzhou, Shanghai, and Taipei. Using responses from 316 students, we find that the Sheth-Newman-Gross Theory of Consumption Values explains how students perceive the services offered by higher education institutions. Students…

Agreement of NP and VP Coordination in English and Korean

ERIC Educational Resources Information Center

Hong, Sung-Ryong; Na, Won-Shik

2011-01-01

There have been long argumentations about this topic and people are still having difficulty in explaining precisely what the agreement values the mother NP phrase should have from two conjunct daughters which have different AGR (Agreement) values. Especially, this could be more complicated when the values of gender, number, and person of each…

Developing Early Place-Value Understanding: A Framework for Tens Awareness

ERIC Educational Resources Information Center

Young-Loveridge, Jenny; Bicknell, Brenda

2016-01-01

This paper outlines a framework to explain the early development of place-value understanding based on an analysis of data from 84 five- to seven-year-old children from diverse cultural and linguistic backgrounds. The children were assessed individually on number knowledge tasks (recalled facts, subitizing, counting, place-value understanding) and…

An Exclusion Zone for Ca2+ Channels around Docked Vesicles Explains Release Control by Multiple Channels at a CNS Synapse

PubMed Central

Keller, Daniel; Babai, Norbert; Kochubey, Olexiy; Han, Yunyun; Markram, Henry; Schürmann, Felix; Schneggenburger, Ralf

2015-01-01

The spatial arrangement of Ca2+ channels and vesicles remains unknown for most CNS synapses, despite of the crucial importance of this geometrical parameter for the Ca2+ control of transmitter release. At a large model synapse, the calyx of Held, transmitter release is controlled by several Ca2+ channels in a "domain overlap" mode, at least in young animals. To study the geometrical constraints of Ca2+ channel placement in domain overlap control of release, we used stochastic MCell modelling, at active zones for which the position of docked vesicles was derived from electron microscopy (EM). We found that random placement of Ca2+ channels was unable to produce high slope values between release and presynaptic Ca2+ entry, a hallmark of domain overlap, and yielded excessively large release probabilities. The simple assumption that Ca2+ channels can be located anywhere at active zones, except below a critical distance of ~ 30 nm away from docked vesicles ("exclusion zone"), rescued high slope values and low release probabilities. Alternatively, high slope values can also be obtained by placing all Ca2+ channels into a single supercluster, which however results in significantly higher heterogeneity of release probabilities. We also show experimentally that high slope values, and the sensitivity to the slow Ca2+ chelator EGTA-AM, are maintained with developmental maturation of the calyx synapse. Taken together, domain overlap control of release represents a highly organized active zone architecture in which Ca2+ channels must obey a certain distance to docked vesicles. Furthermore, domain overlap can be employed by near-mature, fast-releasing synapses. PMID:25951120

Plasma lipid profiles and epidemiology of atherosclerotic diseases in Taiwan--a unique experience.

PubMed

Pan, W H; Chiang, B N

1995-12-01

Rapid economic growth in Taiwan is accompanied by changing lifestyles, and the mortality pattern has switched from predominantly infectious diseases to chronic diseases. Age-adjusted mortality from heart disease has increased slowly but steadily. However, mortality from heart disease in Taiwan remains low compared with many other countries. Mortality from the cerebrovascular diseases has decreased gradually. Current age- and sex-specific values of blood cholesterol low density lipoprotein cholesterol (LDL-C) and triglyceride (TG) are, in general, higher than values in mainland China, but lower than those in the NHANES III and PROCAM studies. From 1950 to 1987, percent dietary fat increased from 16% to 36% in Taiwan. However, a high polyunsaturated fat/saturated fat (P/S) ratio (1.3) maintained during this period may in part explain the favorable blood lipid status and low mortality from heart disease. Data from prospective studies are scarce. In case-control studies carried out in Chinese, significantly higher values of TG, CHOL LDL-C, but lower high density lipoprotein cholesterol (HDL-C) levels have often been found in coronary artery disease (CAD) patients than in controls. The percent differences in TG and HDL-C values (20%) were much greater than those of CHOL and LDL-C (3%). A few studies have identified the TG level as an independent risk factor for stroke and CAD in Taiwan, where a moderate to high fat diet with an advantageous P/S ratio is consumed.

Exploration of making date seed’s flour and its nutritional contents analysis

NASA Astrophysics Data System (ADS)

Wahini, M.

2016-04-01

The date palm (Phoenix dactylifera L) is one of the oldest fruit plants that identical with people’s lives in the Middle East including The Kingdom of Saudi Arabia since ancient times.The date palm is known and consumed by most of people in the form of fruit flesh, while its seed is discarded tough it is rich in nutrient. Therefore, need to be explored the potential of date seed through product innovation of foodstuffs with a high nutritional value. The aims of this study were to 1) know how to make flour from date seed, and 2) determine nutritional content of date seed’s flour. This study was experiment and conducted in July, 2015 at the laboratory of food technology, Family Welfare Education department. Chemical analysis was used to determine nutrients content. The results showed that 1) the flour of date seed produced from the process of washing, soaking, flushing, boiling, draining, drying, grinding, and sieving; 2) the flour of date seed’s flour have a macro nutrients value. This study explains that date seed is regarded as rubbish, in fact, it has a high value that can be an alternative substitution of wheat flour.

Drift as a mechanism for cultural change: an example from baby names.

PubMed Central

Hahn, Matthew W; Bentley, R Alexander

2003-01-01

In the social sciences, there is currently no consensus on the mechanism by which cultural elements come and go in human society. For elements that are value-neutral, an appropriate null model may be one of random copying between individuals in the population. We show that the frequency distributions of baby names used in the United States in each decade of the twentieth century, for both males and females, obey a power law that is maintained over 100 years even though the population is growing, names are being introduced and lost every decade and large changes in the frequencies of specific names are common. We show that these distributions are satisfactorily explained by a simple process in which individuals randomly copy names from each other, a process that is analogous to the infinite-allele model of population genetics with random genetic drift. By its simplicity, this model provides a powerful null hypothesis for cultural change. It further explains why a few elements inevitably become highly popular, even if they have no intrinsic superiority over alternatives. Random copying could potentially explain power law distributions in other cultural realms, including the links on the World Wide Web. PMID:12952655

Procedures to Help Program Offices with Earned Value Management

EPA Pesticide Factsheets

EPA’s Earned Value Management (EVM) Procedures describe the Agency methods for collecting and reporting performance information on major IT investments. The EVM Procedures explain how EPA Program Offices are to receive, organize, analyze, and report cost.

The Roles of Cognitive and Motivational Predictors in Explaining School Achievement in Elementary School

ERIC Educational Resources Information Center

Weber, Heike S.; Lu, Liping; Shi, Jiannong; Spinath, Frank M.

2013-01-01

The present study investigated the roles of cognitive (working memory, intelligence) and motivational variables (self-perceived ability, intrinsic value) in explaining school achievement. The sample consisted of N = 320 German elementary school children in the fourth grade. Working memory and intelligence were assessed in the classroom.…

Defining Environmental Education. Workshop Resource Manual.

ERIC Educational Resources Information Center

Disinger, John F.; Monroe, Martha C.

This booklet is one in a series of resource manuals to help teacher educators conduct environmental education (EE) teacher workshops or promote EE programs. This unit is an orientation to the field of EE. It offers a definition of EE and some ways to explain its value to educators and environmental managers. The unit explains current and…

Stay on or Drop Out? The Role of Identities in Continued Participation at Technical College in Australia

ERIC Educational Resources Information Center

Fisher, Laurel J.

2014-01-01

Identities extend standard models that explain student motivations to complete courses at technical college. A differential hypothesis was that profiles of identities (individuality, belonging and place) explain the self-concepts and task values that contribute to participation, considering demographic factors (age, gender, location, paid work).…

Explaining Human Behavior.

ERIC Educational Resources Information Center

Olson, Alton T.; And Others

The Deductive-Nomological (D-N) model of human behavior is useful and provides the most objective explanation when it is appropriate but it is not necessarily an all-inclusive statement. For instance, explaining human behavior is always an act that entails languages and theories that are value laden and reveal human choices; however the D-N model…

Developmental Change in Social Responsibility during Adolescence: An Ecological Perspective

PubMed Central

Wray-Lake, Laura; Syvertsen, Amy K.; Flanagan, Constance A.

2015-01-01

Social responsibility can be defined as a set of prosocial values representing personal commitments to contribute to community and society. Little is known about developmental change – and predictors of that change – in social responsibility during adolescence. The present study used an accelerated longitudinal research design to investigate the developmental trajectory of social responsibility values and ecological assets across family, school, community, and peer settings that predict these values. Data come from a three-year study of 3,683 U.S. adolescents enrolled in upper-level elementary, middle school, and high schools in rural, semi-urban, and urban communities. Social responsibility values significantly decreased from age 9 to 16 before leveling off in later adolescence. Family compassion messages and democratic climate, school solidarity, community connectedness, and trusted friendship positively predicted within-person change in adolescents’ social responsibility values. These findings held after accounting for other individual-level and demographic factors and provide support for the role of ecological assets in adolescents’ social responsibility development. In addition, fair society beliefs and volunteer experience had positive between- and within-person associations with social responsibility values. The manuscript discusses theoretical and practical implications of the conclusion that declines in ecological assets may partly explain age-related declines in social responsibility values. PMID:26619322

Discrepancy among acute guideline levels for emergency response.

PubMed

Oberg, Mattias; Palmen, Nicole; Johanson, Gunnar

2010-12-15

Acute guidance values are tools for public health risk assessment and management during planning, preparedness and response related to sudden airborne release of hazardous chemicals. The two most frequently used values, i.e. Acute Exposure Guidance Levels (AEGL) and Emergency Response Planning Guideline (ERPG), were compared in qualitative and quantitative terms. There was no significant difference between the general level of AEGL and ERPG values, suggesting the two systems are equally precautious. However, the guidance values diverged by a factor of 3 or more for almost 40% of the substances, including many of high production volume. These deviations could be explained by differences in selection of critical effect or critical study and in a few cases differences in interpretation of the same critical study. Diverging guidance values may hamper proper risk communication and risk management. Key factors for broad international acceptance of harmonized values include transparency of the decision process, agreement on definition of toxicological tiers, and a target population including sensitive groups of the general population. In addition, development of purely health based values is encouraged. Risk management issues, such as land use and emergency response planning should be treated separately, as these rely on national legislation and considerations. Copyright © 2010 Elsevier B.V. All rights reserved.

Developmental change in social responsibility during adolescence: An ecological perspective.

PubMed

Wray-Lake, Laura; Syvertsen, Amy K; Flanagan, Constance A

2016-01-01

Social responsibility can be defined as a set of prosocial values representing personal commitments to contribute to community and society. Little is known about developmental change-and predictors of that change-in social responsibility during adolescence. The present study used an accelerated longitudinal research design to investigate the developmental trajectory of social responsibility values and ecological assets across family, school, community, and peer settings that predict these values. Data come from a 3-year study of 3,683 U.S. adolescents enrolled in upper-level elementary, middle, and high schools in rural, semiurban, and urban communities. Social responsibility values significantly decreased from age 9 to 16 before leveling off in later adolescence. Family compassion messages and democratic climate, school solidarity, community connectedness, and trusted friendship, positively predicted within-person change in adolescents' social responsibility values. These findings held after accounting for other individual-level and demographic factors and provide support for the role of ecological assets in adolescents' social responsibility development. In addition, fair society beliefs and volunteer experience had positive between- and within-person associations with social responsibility values. The manuscript discusses theoretical and practical implications of the conclusion that declines in ecological assets may partly explain age-related declines in social responsibility values. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Aerosol-Cloud Interaction Determined by Both in Situ and Satellite Data Over a Northern High-Latitude Site

NASA Technical Reports Server (NTRS)

Lihavainen, H.; Kerminen, V.-M.; Remer, L. A.

2009-01-01

The first aerosol indirect effect over a clean, northern high-latitude site was investigated by determining the aerosol cloud interaction (ACI) using three different approaches; ground-based in situ measurements, combined ground-based in situ measurements 5 and satellite retrievals and using only satellite retrievals. The obtained values of ACI were highest for in situ ground-based data, clearly lower for combined ground-based and satellite data, and lowest for data relying solely on satellite retrievals. One of the key findings of this study was the high sensitivity of ACI to the definition of the aerosol burden. We showed that at least a part of the variability in ACI can be explained by 10 how different investigators have related dierent cloud properties to "aerosol burden".

Monte Carlo Solution to Find Input Parameters in Systems Design Problems

NASA Astrophysics Data System (ADS)

Arsham, Hossein

2013-06-01

Most engineering system designs, such as product, process, and service design, involve a framework for arriving at a target value for a set of experiments. This paper considers a stochastic approximation algorithm for estimating the controllable input parameter within a desired accuracy, given a target value for the performance function. Two different problems, what-if and goal-seeking problems, are explained and defined in an auxiliary simulation model, which represents a local response surface model in terms of a polynomial. A method of constructing this polynomial by a single run simulation is explained. An algorithm is given to select the design parameter for the local response surface model. Finally, the mean time to failure (MTTF) of a reliability subsystem is computed and compared with its known analytical MTTF value for validation purposes.

Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: Greater sage-grouse and cottontail rabbits

USGS Publications Warehouse

Fedy, B.C.; Doherty, K.E.

2011-01-01

Animal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse (Centrocercus urophasianus) and cottontail rabbits (Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles (r = 0. 77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes. ?? 2010 US Government.

The role of personal values and basic traits in perceptions of the consequences of immigration: a three-nation study.

PubMed

Vecchione, Michele; Caprara, Gianvittorio; Schoen, Harald; Castro, Josè Luis Gonzàlez; Schwartz, Shalom H

2012-08-01

Using data from Italy, Spain, and Germany (N= 1,569), this study investigated the role of basic values (universalism and security) and basic traits (openness and agreeableness) in predicting perceptions of the consequences of immigration. In line with Schwartz's (1992) theory, we conceptualized security as having two distinct components, one concerned with safety of the self (personal security) and the other with harmony and stability of larger groups and of society (group security). Structural equation modelling revealed that universalism values underlie perceptions that immigration has positive consequences and group security values underlie perceptions that it has negative consequences. Personal security makes no unique, additional contribution. Multi-group analyses revealed that these associations are invariant across the three countries except for a stronger link between universalism and perceptions of the consequences of immigration in Spain. To examine whether values mediate relations of traits to perceptions of immigration, we used the five-factor model. Findings supported a full mediation model. Individuals' traits of openness and agreeableness explained significant variance in security and universalism values. Basic values, in turn, explained perceptions of the consequences of immigration. ©2011 The British Psychological Society.

Explosive X-point collapse in relativistic magnetically dominated plasma

NASA Astrophysics Data System (ADS)

Lyutikov, Maxim; Sironi, Lorenzo; Komissarov, Serguei S.; Porth, Oliver

2017-12-01

The extreme properties of the gamma-ray flares in the Crab nebula present a clear challenge to our ideas on the nature of particle acceleration in relativistic astrophysical plasma. It seems highly unlikely that standard mechanisms of stochastic type are at work here and hence the attention of theorists has switched to linear acceleration in magnetic reconnection events. In this series of papers, we attempt to develop a theory of explosive magnetic reconnection in highly magnetized relativistic plasma which can explain the extreme parameters of the Crab flares. In the first paper, we focus on the properties of the X-point collapse. Using analytical and numerical methods (fluid and particle-in-cell simulations) we extend Syrovatsky's classical model of such collapse to the relativistic regime. We find that the collapse can lead to the reconnection rate approaching the speed of light on macroscopic scales. During the collapse, the plasma particles are accelerated by charge-starved electric fields, which can reach (and even exceed) values of the local magnetic field. The explosive stage of reconnection produces non-thermal power-law tails with slopes that depend on the average magnetization . For sufficiently high magnetizations and vanishing guide field, the non-thermal particle spectrum consists of two components: a low-energy population with soft spectrum that dominates the number census; and a high-energy population with hard spectrum that possesses all the properties needed to explain the Crab flares.

Large fluctuations in the high-redshift metagalactic ionizing background

NASA Astrophysics Data System (ADS)

D'Aloisio, Anson; McQuinn, Matthew; Davies, Frederick B.; Furlanetto, Steven R.

2018-01-01

Recent observations have shown that the scatter in opacities amongst coeval segments of the Ly α forest increases rapidly at z > 5. In this paper, we assess whether the large scatter can be explained by fluctuations in the ionizing background in the post-reionization intergalactic medium. We find that matching the observed scatter at z ≈ 5.5 requires a short spatially averaged mean free path of 〈λmfp912〉 ≲ 15 h- 1 comoving Mpc, a factor of ≳3 shorter than direct measurements at z = 5.2. We argue that such rapid evolution in the mean free path is difficult to reconcile with our measurements of the global H I photoionization rate, which stay approximately constant over the interval z ≈ 4.8-5.5. However, we also show that measurements of the mean free path at z > 5 are likely biased towards higher values by the quasar proximity effect. This bias can reconcile the short values of 〈λmfp912〉 that are required to explain the large scatter in opacities. We discuss the implications of this scenario for cosmological reionization. Finally, we investigate whether other statistics applied to the z > 5 Ly α forest can shed light on the origin of the scatter. Compared to a model with a uniform ionizing background, models that successfully account for the scatter lead to enhanced power in the line-of-sight flux power spectrum on scales k ≲0.1 h Mpc-1. We find tentative evidence for this enhancement in observations of the high-redshift Ly α forest.

Evolution of fairness and coalition formation in three-person ultimatum games.

PubMed

Nishimura, Takeshi; Okada, Akira; Shirata, Yasuhiro

2017-05-07

We consider the evolution of fairness and coalition formation in a three-person ultimatum game in which the coalition value depends on its size. Traditional game theory, which assumes selfish and rational players, predicts the largest and efficient coalition with a proposer exploiting most of the total value. In a stochastic evolutionary model (the frequency-dependent Moran process with mutations) where players make errors in estimating the payoffs and strategies of others, evolutionary selection favors the formation of a two-person subcoalition under weak selection and in the low mutation limit if and only if its coalition value exceeds a high proportion (0.7) of that of the largest coalition. Proposers offer 30-35% of the subcoalition value to a coalition member, excluding a non-member. Multilateral bargaining is critically different from the bilateral one. Coalition-forming behavior may cause economic inefficiency and social exclusion. Stochastic evolutionary game theory thus provides theoretical support to explain the behavior of human subjects in economic experiments of a three-person ultimatum game. Copyright © 2017 Elsevier Ltd. All rights reserved.

Explaining academic-track boys' underachievement in language grades: Not a lack of aptitude but students' motivational beliefs and parents' perceptions?

PubMed

Heyder, Anke; Kessels, Ursula; Steinmayr, Ricarda

2017-06-01

Boys earn lower grades in languages than girls. The expectancy-value model by Eccles et al. (, A series of books in psychology. Achievement and achievement motives. Psychological and sociological approaches, W.H. Freeman, San Francisco, CA, 76) is a comprehensive theoretical model for explaining gender differences in educational outcomes. In the past, most studies have focused on girls' disadvantage in math and science and on the role of the students' motivational beliefs. We aimed to explain boys' lower language grades by applying the expectancy-value model while taking into account students' motivational beliefs as well as their aptitude, prior achievement, and socializers' beliefs. In addition, we aimed at exploring the incremental contribution of each potential mediator. Five hundred and twenty German students (age M = 17 years; 58% female) and 374 parents (age M = 47 years). Student-reported ability self-concept (ASC) and task values, parents' perceptions of students' ability, students' prior achievement as reported by schools, and students' verbal intelligence test scores were all tested as mediators of the effect of gender on grades in German while controlling for parents' socioeconomic status. Single-mediator models and a multiple-mediator model were estimated using structural equation modelling. All variables proved to be relevant for explaining boys' underachievement in language grades. Whereas students' ASC, task values, prior achievement, and parents' perceptions mediated the gender effect, verbal intelligence was identified as a suppressor variable increasing the gender effect. Our results challenge the stereotypic belief that boys' lower grades are due to lower verbal aptitude. Rather, students' motivational beliefs and parents' perceptions seem critical factors. Implications for both future research and practice are discussed. © 2017 The British Psychological Society.

The relationship of live animal muscular and skeletal scores, ultrasound measurements and carcass classification scores with carcass composition and value in steers.

PubMed

Conroy, S B; Drennan, M J; Kenny, D A; McGee, M

2009-11-01

This study examined the relationship of muscular and skeletal scores and ultrasound measurements in the live animal, and carcass conformation and fat scores with carcass composition and value using 336 steers, slaughtered at 2 years of age. Live animal scores and measurements were recorded at 8 to 12 months of age and pre-slaughter. Following slaughter, each carcass was classified for conformation and fatness and the right side dissected into meat, fat and bone. Carcass conformation scores and fat scores were both measured on a continuous 15-point scale and ranged from 2.0 to 12.0 and from 2.8 to 13.3, respectively. Pre-slaughter muscular scores showed positive correlations (P < 0.001) ranging from 0.31 to 0.86 with carcass meat proportion, proportion of high-value cuts in the carcass, conformation score and carcass value, significant negative correlations with carcass fat (r = -0.13) and bone (r = -0.81) proportions, and generally low non-significant relationships with the proportion of high-value cuts in meat and carcass fat score. Pre-slaughter ultrasound muscle depth and carcass conformation score showed similar correlations with carcass traits to those using the pre-slaughter muscular scoring procedure. Pre-slaughter ultrasound fat depth showed positive correlations (P < 0.001) with carcass fat proportion (r = 0.59) and fat score (r = 0.63), and significant negative correlations (-0.23 to -0.50) with carcass meat and bone proportions, high-value cuts in the carcass and in meat, and carcass value. Pre-slaughter skeletal scores generally showed poor correlations ranging from -0.38 to 0.52 with the various carcass traits. Corresponding correlations (-0.26 to 0.44) involving records collected at 8 to 12 months of age were lower than those using pre-slaughter records. A one-unit increase in carcass conformation score increased carcass meat proportion and value by 11.2 g/kg and 5.6 cents/kg, respectively. Corresponding values for fat score were -8.2 g/kg and -5.1 cents/kg. In conclusion, both pre-slaughter live animal scores/measurements and carcass classification scores, explained an appreciable amount of the total variation in carcass meat, fat and bone proportions and carcass value, and a moderate amount of the variation in proportion of high-value meat cuts in the carcass.

The Value of Color in Newspaper Design.

ERIC Educational Resources Information Center

Bohle, Robert

1987-01-01

Discusses the ways in which color halftones can be used in campus newspapers to attract attention to ads, headlines, and editorial copy. Explains how to change the hue, value, and saturation of a color and the effects the changes should achieve. (AYC)

Chemostratigraphic and U-Pb geochronologic constraints on carbon cycling across the Silurian-Devonian boundary

NASA Astrophysics Data System (ADS)

Husson, Jon M.; Schoene, Blair; Bluher, Sarah; Maloof, Adam C.

2016-02-01

The Devonian Period hosts extraordinary changes to Earth's biosphere. Land plants began their rise to prominence, with early vascular vegetation beginning its colonization of near-shore environments in the latest Silurian. Across the Silurian-Devonian (Pridoli-Lochkovian) transition, carbon isotope analyses of bulk marine carbonates (δC13carb) from Laurentian and Baltic successions reveal a positive δC13carb shift. Known as the Klonk Event, values reach + 5.8 ‰, making it one of the largest carbon isotope excursions in the Phanerozoic. Assigning rates and durations to these significant events requires a robust, precise Devonian time scale. Here we present 675 micritic matrix and 357 fossil-specific δC13carb analyses from the lower Devonian Helderberg Group of New York and West Virginia that exhibit the very positive δC13carb values observed in other Silurian-Devonian basins. This chemostratigraphic dataset is coupled with 66 ID-TIMS U-Pb dates on single zircons from six ash falls intercalated within Helderberg sediments, including dates on the stratigraphically lowest Devonian ashes yet developed. In this work, we (a) demonstrate that matrix and fossil-specific δC13carb values track one another closely in the Helderberg Group, (b) estimate the Silurian-Devonian boundary age in New York to be 421.3 ± 1.2 Ma (2σ; including decay constant uncertainties), and (c) calculate the time required to evolve from baseline to peak δC13carb values at the onset of the Klonk event to be 1.00 ± 0.25 Myr. Under these constraints, a steady-state perturbation to the global carbon cycle can explain the observed excursion with modern fluxes, as long as DIC concentration in the Devonian ocean remained below ∼2× the modern value. Therefore, potential drivers, such as enhanced burial of organic carbon, need not rely on anomalously high total fluxes of carbon to explain the Klonk Event.

SETs: stand evaluation tools: II. tree value conversion standards for hardwood sawtimber

Treesearch

Joseph J. Mendel; Paul S. DeBald; Martin E. Dale

1976-01-01

Tree quatity index tables are presented for 12 important hardwood species of the oak-hickory forest. From these, tree value conversion standards are developed for each species, log grade, merchantable height, and diameter at breast height. The method of calculating tree value conversion standards and adapting them to different conditions is explained. A computer...

Determining the rate of value increase for oaks

Treesearch

Paul S. DeBald; Joseph J. Mendel

1971-01-01

A method used to develop rate of value increase is described as an aid to management decision-making. Regional rates of value increase and financial maturity diameters for ten species common to the oak-hickory type are outlined, and the economic principles involved are explained to show how they apply to either individual trees or stands.

30 CFR 206.172 - How do I value gas produced from leases in an index zone?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (b) explains how you must value the following four types of gas: (i) Gas production before processing; (ii) Gas production that you certify on Form MMS-4410, Certification for Not Performing Accounting for... gas production that is not sold under an arm's-length dedicated contract is the index-based value...

Leading Change, Adding Value.

PubMed

Evans, Nick

2016-07-01

Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It builds on Compassion in Practice (CiP), which set out the 6Cs. While CiP established the values of nursing and midwifery, the new framework explains how staff can help transform the health and care sectors to meet the aims of NHS England's Five Year Forward View.

A Neural Circuit Mechanism for the Involvements of Dopamine in Effort-Related Choices: Decay of Learned Values, Secondary Effects of Depletion, and Calculation of Temporal Difference Error

PubMed Central

2018-01-01

Abstract Dopamine has been suggested to be crucially involved in effort-related choices. Key findings are that dopamine depletion (i) changed preference for a high-cost, large-reward option to a low-cost, small-reward option, (ii) but not when the large-reward option was also low-cost or the small-reward option gave no reward, (iii) while increasing the latency in all the cases but only transiently, and (iv) that antagonism of either dopamine D1 or D2 receptors also specifically impaired selection of the high-cost, large-reward option. The underlying neural circuit mechanisms remain unclear. Here we show that findings i–iii can be explained by the dopaminergic representation of temporal-difference reward-prediction error (TD-RPE), whose mechanisms have now become clarified, if (1) the synaptic strengths storing the values of actions mildly decay in time and (2) the obtained-reward-representing excitatory input to dopamine neurons increases after dopamine depletion. The former is potentially caused by background neural activity–induced weak synaptic plasticity, and the latter is assumed to occur through post-depletion increase of neural activity in the pedunculopontine nucleus, where neurons representing obtained reward exist and presumably send excitatory projections to dopamine neurons. We further show that finding iv, which is nontrivial given the suggested distinct functions of the D1 and D2 corticostriatal pathways, can also be explained if we additionally assume a proposed mechanism of TD-RPE calculation, in which the D1 and D2 pathways encode the values of actions with a temporal difference. These results suggest a possible circuit mechanism for the involvements of dopamine in effort-related choices and, simultaneously, provide implications for the mechanisms of TD-RPE calculation. PMID:29468191

Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States.

PubMed

Steimer, Andreas; Schindler, Kaspar

2015-01-01

Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon's implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike's preceding ISI. As we show, the EIF's exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron's ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing computational theories about UP states during slow wave sleep and present possible extensions of the model in the context of spike-frequency adaptation.

Atmospheric Pressure Plasma Jet Treatment of Poly-ε-caprolactone Polymer Solutions To Improve Electrospinning.

PubMed

Grande, Silvia; Van Guyse, Joachim; Nikiforov, Anton Y; Onyshchenko, Iuliia; Asadian, Mahtab; Morent, Rino; Hoogenboom, Richard; De Geyter, Nathalie

2017-09-27

An atmospheric pressure plasma jet (APPJ) specifically designed for liquid treatment has been used in this work to improve the electrospinnability of a 5 w/v % solution of poly-ε-caprolactone (PCL) in a mixture of chloroform and N,N-dimethylformamide. Untreated PCL solutions were found to result in nonuniform fibers containing a large number of beads, whereas plasma-treated solutions (exposure time of 2-5 min) enabled the generation of beadless, uniform nanofibers with an average diameter of 450 nm. This enhanced electrospinnability was found to be mainly due to the highly increased conductivity of the plasma-modified PCL solutions. Consequently, more stretching of the polymer jet occurred during electrospinning, leading to the generation of bead-free fibers. Plasma treatment also results in an increased viscosity and decreased pH values. To explain these observed changes, optical emission spectroscopy (OES) has been used to examine the excited species present in the APPJ in contact with the PCL solution. This study revealed that the peaks attributed to H, CH, CH 2 , and C 2 species could be responsible for the degradation of solvent molecules and/or PCL structures during the plasma treatment. Size exclusion chromatography and X-ray photoelectron spectroscopy results showed that the molecular weight and the chemical composition of PCL were not significantly affected by the APPJ treatment. Plasma exposure mainly results in the degradation of the solvent molecules instead of modifying the PCL macromolecules, preserving the original polymer as much as possible. A hypothesis for the observed macroscopic changes in viscosity and pH values could be the generation of new chemical species such as HCl and/or HNO 3 . These species are characterized by their high conductivity, low pH values, and strong polarity and could enhance the solvent quality for PCL, leading to the expansion of the polymer coil, which could in turn explain the observed enhanced viscosity after plasma modification.

Educational Attainment: A Genome Wide Association Study in 9538 Australians

PubMed Central

Martin, Nicolas W.; Medland, Sarah E.; Verweij, Karin J. H.; Lee, S. Hong; Nyholt, Dale R.; Madden, Pamela A.; Heath, Andrew C.; Montgomery, Grant W.; Wright, Margaret J.; Martin, Nicholas G.

2011-01-01

Background Correlations between Educational Attainment (EA) and measures of cognitive performance are as high as 0.8. This makes EA an attractive alternative phenotype for studies wishing to map genes affecting cognition due to the ease of collecting EA data compared to other cognitive phenotypes such as IQ. Methodology In an Australian family sample of 9538 individuals we performed a genome-wide association scan (GWAS) using the imputed genotypes of ∼2.4 million single nucleotide polymorphisms (SNP) for a 6-point scale measure of EA. Top hits were checked for replication in an independent sample of 968 individuals. A gene-based test of association was then applied to the GWAS results. Additionally we performed prediction analyses using the GWAS results from our discovery sample to assess the percentage of EA and full scale IQ variance explained by the predicted scores. Results The best SNP fell short of having a genome-wide significant p-value (p = 9.77×10−7). In our independent replication sample six SNPs among the top 50 hits pruned for linkage disequilibrium (r2<0.8) had a p-value<0.05 but only one of these SNPs survived correction for multiple testing - rs7106258 (p = 9.7*10−4) located in an intergenic region of chromosome 11q14.1. The gene based test results were non-significant and our prediction analyses show that the predicted scores explained little variance in EA in our replication sample. Conclusion While we have identified a polymorphism chromosome 11q14.1 associated with EA, further replication is warranted. Overall, the absence of genome-wide significant p-values in our large discovery sample confirmed the high polygenic architecture of EA. Only the assembly of large samples or meta-analytic efforts will be able to assess the implication of common DNA polymorphisms in the etiology of EA. PMID:21694764

Anomalously high b-values in the South Flank of Kilauea volcano, Hawaii: Evidence for the distribution of magma below Kilauea's East rift zone

USGS Publications Warehouse

Wyss, M.; Klein, F.; Nagamine, K.; Wiemer, S.

2001-01-01

The pattern of b-value of the frequency-magnitude relation, or mean magnitude, varies little in the Kaoiki-Hilea area of Hawaii, and the b-values are normal, with b = 0.8 in the top 10 km and somewhat lower values below that depth. We interpret the Kaoiki-Hilea area as relatively stable, normal Hawaiian crust. In contrast, the b-values beneath Kilauea's South Flank are anomalously high (b = 1.3-1.7) at depths between 4 and 8 km, with the highest values near the East Rift zone, but extending 5-8 km away from the rift. Also, the anomalously high b-values vary along strike, parallel to the rift zone. The highest b-values are observed near Hiiaka and Pauahi craters at the bend in the rift, the next highest are near Makaopuhi and also near Puu Kaliu. The mildest anomalies occur adjacent to the central section of the rift. The locations of the three major and two minor b-value anomalies correspond to places where shallow magma reservoirs have been proposed based on analyses of seismicity, geodetic data and differentiated lava chemistry. The existence of the magma reservoirs is also supported by magnetic anomalies, which may be areas of dike concentration, and self-potential anomalies, which are areas of thermal upwelling above a hot source. The simplest explanation of these anomalously high b-values is that they are due to the presence of active magma bodies beneath the East Rift zone at depths down to 8 km. In other volcanoes, anomalously high b-values correlate with volumes adjacent to active magma chambers. This supports a model of a magma body beneath the East Rift zone, which may widen and thin along strike, and which may reach 8 km depth and extend from Kilauea's summit to a distance of at least 40 km down rift. The anomalously high b-values at the center of the South Flank, several kilometers away from the rift, may be explained by unusually high pore pressure throughout the South Flank, or by anomalously strong heterogeneity due to extensive cracking, or by both phenomena. The major b-value anomalies are located SSE of their parent reservoirs, in the direction of motion of the flank, suggesting that magma reservoirs leave an imprint in the mobile flank. We hypothesize that the extensive cracking may have been acquired when the anomalous parts of the South Flank, now several kilometers distant from the rift zone, were generated at the rift zone near persistent reservoirs. Since their generation, these volumes may have moved seaward, away from the rift, but earthquakes occurring in them still use the preexisting complex crack distribution. Along the decollement plane at 10 km depth, the b-values are exceptionally low (b = 0.5), suggesting faulting in a more homogeneous medium. ?? 2001 Elsevier Science B.V. All rights reserved.

Semen molecular and cellular features: these parameters can reliably predict subsequent ART outcome in a goat model

PubMed Central

Berlinguer, Fiammetta; Madeddu, Manuela; Pasciu, Valeria; Succu, Sara; Spezzigu, Antonio; Satta, Valentina; Mereu, Paolo; Leoni, Giovanni G; Naitana, Salvatore

2009-01-01

Currently, the assessment of sperm function in a raw or processed semen sample is not able to reliably predict sperm ability to withstand freezing and thawing procedures and in vivo fertility and/or assisted reproductive biotechnologies (ART) outcome. The aim of the present study was to investigate which parameters among a battery of analyses could predict subsequent spermatozoa in vitro fertilization ability and hence blastocyst output in a goat model. Ejaculates were obtained by artificial vagina from 3 adult goats (Capra hircus) aged 2 years (A, B and C). In order to assess the predictive value of viability, computer assisted sperm analyzer (CASA) motility parameters and ATP intracellular concentration before and after thawing and of DNA integrity after thawing on subsequent embryo output after an in vitro fertility test, a logistic regression analysis was used. Individual differences in semen parameters were evident for semen viability after thawing and DNA integrity. Results of IVF test showed that spermatozoa collected from A and B lead to higher cleavage rates (0 < 0.01) and blastocysts output (p < 0.05) compared with C. Logistic regression analysis model explained a deviance of 72% (p < 0.0001), directly related with the mean percentage of rapid spermatozoa in fresh semen (p < 0.01), semen viability after thawing (p < 0.01), and with two of the three comet parameters considered, i.e tail DNA percentage and comet length (p < 0.0001). DNA integrity alone had a high predictive value on IVF outcome with frozen/thawed semen (deviance explained: 57%). The model proposed here represents one of the many possible ways to explain differences found in embryo output following IVF with different semen donors and may represent a useful tool to select the most suitable donors for semen cryopreservation. PMID:19900288

Anaerobic Biotransformation and Mobility of Pu and of Pu-EDTA

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

Xun, Luying

2009-11-20

The enhanced mobility of radionuclides by co-disposed chelating agent, ethylenediaminetetraacetate (EDTA), is likely to occur only under anaerobic conditions. Our extensive effort to enrich and isolate anaerobic EDTA-degrading bacteria has failed. Others has tried and also failed. To explain the lack of anaerobic biodegradation of EDTA, we proposed that EDTA has to be transported into the cells for metabolism. A failure of uptake may contribute to the lack of EDTA degradation under anaerobic conditions. We demonstrated that an aerobic EDTA-degrading bacterium strain BNC1 uses an ABC-type transporter system to uptake EDTA. The system has a periplasmic binding protein that bindmore » EDTA and then interacts with membrane proteins to transport EDTA into the cell at the expense of ATP. The bind protein EppA binds only free EDTA with a Kd of 25 nM. The low Kd value indicates high affinity. However, the Kd value of Ni-EDTA is 2.4 x 10^(-10) nM, indicating much stronger stability. Since Ni and other trace metals are essential for anaerobic respiration, we conclude that the added EDTA sequestrates all trace metals and making anaerobic respiration impossible. Thus, the data explain the lack of anaerobic enrichment cultures for EDTA degradation. Although we did not obtain an EDTA degrading culture under anaerobic conditions, our finding may promote the use of certain metals that forms more stable metal-EDTA complexes than Pu(III)-EDTA to prevent the enhanced mobility. Further, our data explain why EDTA is the most dominant organic pollutant in surface waters, due to the lack of degradation of certain metal-EDTA complexes.« less

Bank Regulation: Analysis of the Failure of Superior Bank, FSB, Hinsdale, Illinois

DTIC Science & Technology

2002-02-07

statement of financial position based on the fair value . The best evidence of fair value is a quoted market price in an active market, but if there is no...market price, the value must be estimated. In estimating the fair value of retained interests, valuation techniques include estimating the present...about interest rates, default, prepayment, and volatility. In 1999, FASB explained that when estimating the fair value for 7FAS No. 140: Accounting for

Formation and structure of stable aggregates in binary diffusion-limited cluster-cluster aggregation processes

NASA Astrophysics Data System (ADS)

López-López, J. M.; Moncho-Jordá, A.; Schmitt, A.; Hidalgo-Álvarez, R.

2005-09-01

Binary diffusion-limited cluster-cluster aggregation processes are studied as a function of the relative concentration of the two species. Both, short and long time behaviors are investigated by means of three-dimensional off-lattice Brownian Dynamics simulations. At short aggregation times, the validity of the Hogg-Healy-Fuerstenau approximation is shown. At long times, a single large cluster containing all initial particles is found to be formed when the relative concentration of the minority particles lies above a critical value. Below that value, stable aggregates remain in the system. These stable aggregates are composed by a few minority particles that are highly covered by majority ones. Our off-lattice simulations reveal a value of approximately 0.15 for the critical relative concentration. A qualitative explanation scheme for the formation and growth of the stable aggregates is developed. The simulations also explain the phenomenon of monomer discrimination that was observed recently in single cluster light scattering experiments.

Highly efficient and stable ultraviolet photocathode based on nanodiamond particles

NASA Astrophysics Data System (ADS)

Velardi, L.; Valentini, A.; Cicala, G.

2016-02-01

Nanodiamond (ND) layers on silicon substrate are deposited by the pulsed spray technique starting from nanoparticles of about 250 nm dispersed in 1,2-dichloroethane solvent. The aim of this letter is to investigate the quantum efficiency (QE) of photocathodes based on ND particles in the vacuum ultraviolet spectral range. Various ND layers are examined employing as-received and hydrogenated nanoparticles. As expected, the hydrogen plasma treatment improves strongly the photoemission of the layer giving a QE of 22% at 146 nm. Indeed, this efficiency value is achieved only if the particles are treated in H2 microwave plasma before the growth of the sprayed layer rather than to hydrogenate the already formed one. These QE values are higher than those of photocathodes based on plasma chemical vapor deposition diamond films, but with the advantage of being much stable, too. The highest QE values are explained to be due to the intrinsic chemical and structural features of utilized ND particles.

The Power of Why: Connecting Curriculum to Students' Lives

ERIC Educational Resources Information Center

Egbert, Joy; Roe, Mary F.

2014-01-01

Student disengagement can be a major impediment to effective student learning. When parents and educators cannot provide adequate reasoning to explain the value of what is taught at home and in school, students can lose their motivation to learn and be engaged in classroom activities. In this article, the authors explain the importance of teacher…

Why Flies? Inexpensive Public Engagement Exercises to Explain the Value of Basic Biomedical Research on "Drosophila melanogaster"

ERIC Educational Resources Information Center

Pulver, Stefan R.; Cognigni, Paola; Denholm, Barry; Fabre, Caroline; Gu, Wendy X. W.; Linneweber, Gerit; Prieto-Godino, Lucia; Urbancic, Vasja; Zwart, Maarten; Miguel-Aliaga, Irene

2011-01-01

Invertebrate model organisms are powerful systems for uncovering conserved principles of animal biology. Despite widespread use in scientific communities, invertebrate research is often severely undervalued by laypeople. Here, we present a set of simple, inexpensive public outreach exercises aimed at explaining to the public why basic research on…

The Role of Attitudes about Vaccine Safety, Efficacy, and Value in Explaining Parents' Reported Vaccination Behavior

ERIC Educational Resources Information Center

LaVail, Katherine Hart; Kennedy, Allison Michelle

2013-01-01

Objectives: To explain vaccine confidence as it related to parents' decisions to vaccinate their children with recommended vaccines, and to develop a confidence measure to efficiently and effectively predict parents' self-reported vaccine behaviors. Method: A sample of parents with at least one child younger than 6 years ("n" = 376) was…

Individual differences in valuing mates' physical attractiveness.

PubMed

Mathes, Eugene W; Bielser, Abby; Cassell, Ticcarra; Summers, Sarah; Witowski, Aggie

2006-10-01

To investigate correlates of valuing physical attractiveness in a mate, it was hypothesized that valuing physical attractiveness in a mate would correlate with sex and valuing promiscuous sex, status, personal physical attractiveness, beauty, and order. Men and women college students completed measures of the extent to which they valued physical attractiveness in a mate and other variables. Valuing physical attractiveness in a mate was correlated with sex (men valued physical attractiveness in a mate more than did women) and valuing promiscuous sex and status, and, for women, valuing personal physical attractiveness. The results were explained in terms of evolutionary theory.

The Effects of Supply Chain Orientation, Supply Chain Management, and Collaboration on Perceived Firm Performance

DTIC Science & Technology

2012-06-01

Communalities – Factor Analysis .................................................................... 30 Table 3. Total Variance Explained – Factor Analysis...43 Table 12. Pearson Correlation...standards of corporate values and allying oneself with exchange partners having similar values, (3) communicating valuable information, including

Electrical conductivity of the plagioclase-NaCl-water system and its implication for the high conductivity anomalies in the mid-lower crust of Tibet Plateau

NASA Astrophysics Data System (ADS)

Li, Ping; Guo, Xinzhuan; Chen, Sibo; Wang, Chao; Yang, Junlong; Zhou, Xingfan

2018-02-01

In order to investigate the origin of the high conductivity anomalies geophysically observed in the mid-lower crust of Tibet Plateau, the electrical conductivity of plagioclase-NaCl-water system was measured at 1.2 GPa and 400-900 K. The relationship between electrical conductivity and temperature follows the Arrhenius law. The bulk conductivity increases with the fluid fraction and salinity, but is almost independent of temperature (activation enthalpy less than 0.1 eV). The conductivity of plagioclase-NaCl-water system is much lower than that of albite-NaCl-water system with similar fluid fraction and salinity, indicating a strong effect of the major mineral phase on the bulk conductivity of the brine-bearing system. The high conductivity anomalies of 10-1 and 100 S/m observed in the mid-lower crust of Tibet Plateau can be explained by the aqueous fluid with a volume fraction of 1 and 9%, respectively, if the fluid salinity is 25%. The anomaly value of 10-1 S/m can be explained by the aqueous fluid with a volume fraction of 6% if the salinity is 10%. In case of Southern Tibet where the heat flow is high, the model of a thin layer of brine-bearing aqueous fluid with a high salinity overlying a thick layer of partial melt is most likely to prevail.

Unsteady design-point flow phenomena in transonic compressors

NASA Technical Reports Server (NTRS)

Gertz, J. B.; Epstein, A. H.

1986-01-01

High-frequency response probes which had previously been used exclusively in the MIT Blowndown Facility were successfully employed in two conventional steady state axial flow compressor facilities to investigate the unsteady flowfields of highly loaded transonic compressors at design point operation. Laser anemometry measurements taken simultaneously with the high response data were also analyzed. The time averaged high response data of static and total pressure agreed quite well with the conventional steady state instrumentation except for flow angle which showed a large spread in values at all radii regardless of the type of instrumentation used. In addition, the time resolved measurements confirmed earlier test results obtained in the MIT Blowdown Facility for the same compressor. The results of these tests have further revealed that the flowfields of highly loaded transonic compressors are heavily influenced by unsteady flow phenomena. The high response measurements exhibited large variations in the blade to blade flow and in the blade passage flow. The observed unsteadiness in the blade wakes is explained in terms of the rotor blades' shed vorticity in periodic vortex streets. The wakes were modeled as two-dimensional vortex streets with finite size cores. The model fit the data quite well as it was able to reproduce the average wake shape and bi-modal probability density distributions seen in the laser anemometry data. The presence of vortex streets in the blade wakes also explains the large blade to blade fluctuations seen by the high response probes which is simply due to the intermittent sampling of the vortex street as it is swept past a stationary probe.

Modelling the Wind-Borne Spread of Highly Pathogenic Avian Influenza Virus between Farms

PubMed Central

Ssematimba, Amos; Hagenaars, Thomas J.; de Jong, Mart C. M.

2012-01-01

A quantitative understanding of the spread of contaminated farm dust between locations is a prerequisite for obtaining much-needed insight into one of the possible mechanisms of disease spread between farms. Here, we develop a model to calculate the quantity of contaminated farm-dust particles deposited at various locations downwind of a source farm and apply the model to assess the possible contribution of the wind-borne route to the transmission of Highly Pathogenic Avian Influenza virus (HPAI) during the 2003 epidemic in the Netherlands. The model is obtained from a Gaussian Plume Model by incorporating the dust deposition process, pathogen decay, and a model for the infection process on exposed farms. Using poultry- and avian influenza-specific parameter values we calculate the distance-dependent probability of between-farm transmission by this route. A comparison between the transmission risk pattern predicted by the model and the pattern observed during the 2003 epidemic reveals that the wind-borne route alone is insufficient to explain the observations although it could contribute substantially to the spread over short distance ranges, for example, explaining 24% of the transmission over distances up to 25 km. PMID:22348042

Modelling the wind-borne spread of highly pathogenic avian influenza virus between farms.

PubMed

Ssematimba, Amos; Hagenaars, Thomas J; de Jong, Mart C M

2012-01-01

A quantitative understanding of the spread of contaminated farm dust between locations is a prerequisite for obtaining much-needed insight into one of the possible mechanisms of disease spread between farms. Here, we develop a model to calculate the quantity of contaminated farm-dust particles deposited at various locations downwind of a source farm and apply the model to assess the possible contribution of the wind-borne route to the transmission of Highly Pathogenic Avian Influenza virus (HPAI) during the 2003 epidemic in the Netherlands. The model is obtained from a Gaussian Plume Model by incorporating the dust deposition process, pathogen decay, and a model for the infection process on exposed farms. Using poultry- and avian influenza-specific parameter values we calculate the distance-dependent probability of between-farm transmission by this route. A comparison between the transmission risk pattern predicted by the model and the pattern observed during the 2003 epidemic reveals that the wind-borne route alone is insufficient to explain the observations although it could contribute substantially to the spread over short distance ranges, for example, explaining 24% of the transmission over distances up to 25 km.

Pathway-Based Genome-Wide Association Studies for Two Meat Production Traits in Simmental Cattle.

PubMed

Fan, Huizhong; Wu, Yang; Zhou, Xiaojing; Xia, Jiangwei; Zhang, Wengang; Song, Yuxin; Liu, Fei; Chen, Yan; Zhang, Lupei; Gao, Xue; Gao, Huijiang; Li, Junya

2015-12-17

Most single nucleotide polymorphisms (SNPs) detected by genome-wide association studies (GWAS), explain only a small fraction of phenotypic variation. Pathway-based GWAS were proposed to improve the proportion of genes for some human complex traits that could be explained by enriching a mass of SNPs within genetic groups. However, few attempts have been made to describe the quantitative traits in domestic animals. In this study, we used a dataset with approximately 7,700,000 SNPs from 807 Simmental cattle and analyzed live weight and longissimus muscle area using a modified pathway-based GWAS method to orthogonalise the highly linked SNPs within each gene using principal component analysis (PCA). As a result, of the 262 biological pathways of cattle collected from the KEGG database, the gamma aminobutyric acid (GABA)ergic synapse pathway and the non-alcoholic fatty liver disease (NAFLD) pathway were significantly associated with the two traits analyzed. The GABAergic synapse pathway was biologically applicable to the traits analyzed because of its roles in feed intake and weight gain. The proposed method had high statistical power and a low false discovery rate, compared to those of the smallest P-value and SNP set enrichment analysis methods.

Ferroelectric polymer dielectrics: Emerging materials for future electrostatic energy storage applications

NASA Astrophysics Data System (ADS)

Panda, Maheswar

2018-05-01

In this manuscript, the dielectric behavior of a variety of ferroelectric polymer dielectrics (FPD), which may bethe materials for future electrostatic energy storage application shave been discussed. The variety of polymer dielectrics, comprising of ferroelectric polymer[polyvinylidene fluoride (PVDF)]/non-polarpolymer [low density polyethylene (LDPE)] and different sizes of metal particles (Ni, quasicrystal of Al-Cu-Fe) as filler, were prepared through different process conditions (cold press/hot press) and are investigated experimentally. Very high values of effective dielectric constants (ɛeff) with low loss tangent (Tan δ) were observed forall the prepared FPD at their respective percolation thresholds (fc). The enhancement of ɛeff and Tan δ at the insulator to metal transition (IMT) is explained through the boundary layer capacitor effect and the percolation theory respectively. The non-universal fc/critical exponents across the IMT have been explained through percolation theory andis attributed to the fillerparticle size& shape, interaction between the components, method of their preparation, adhesiveness, connectivity and homogeneity, etc. of the samples. Recent results on developed FPD with high ɛeff and low Tan δ prepared through cold press have proven themselves to be the better candidates for low frequency and static dielectric applications.

Social learning in cooperative dilemmas

PubMed Central

Lamba, Shakti

2014-01-01

Helping is a cornerstone of social organization and commonplace in human societies. A major challenge for the evolutionary sciences is to explain how cooperation is maintained in large populations with high levels of migration, conditions under which cooperators can be exploited by selfish individuals. Cultural group selection models posit that such large-scale cooperation evolves via selection acting on populations among which behavioural variation is maintained by the cultural transmission of cooperative norms. These models assume that individuals acquire cooperative strategies via social learning. This assumption remains empirically untested. Here, I test this by investigating whether individuals employ conformist or payoff-biased learning in public goods games conducted in 14 villages of a forager–horticulturist society, the Pahari Korwa of India. Individuals did not show a clear tendency to conform or to be payoff-biased and are highly variable in their use of social learning. This variation is partly explained by both individual and village characteristics. The tendency to conform decreases and to be payoff-biased increases as the value of the modal contribution increases. These findings suggest that the use of social learning in cooperative dilemmas is contingent on individuals' circumstances and environments, and question the existence of stably transmitted cultural norms of cooperation. PMID:24870041

Regional and local background ozone in Houston during Texas Air Quality Study 2006

NASA Astrophysics Data System (ADS)

Langford, A. O.; Senff, C. J.; Banta, R. M.; Hardesty, R. M.; Alvarez, R. J.; Sandberg, Scott P.; Darby, Lisa S.

2009-04-01

Principal Component Analysis (PCA) is used to isolate the common modes of behavior in the daily maximum 8-h average ozone mixing ratios measured at 30 Continuous Ambient Monitoring Stations in the Houston-Galveston-Brazoria area during the Second Texas Air Quality Study field intensive (1 August to 15 October 2006). Three principal components suffice to explain 93% of the total variance. Nearly 84% is explained by the first component, which is attributed to changes in the "regional background" determined primarily by the large-scale winds. The second component (6%) is attributed to changes in the "local background," that is, ozone photochemically produced in the Houston area and spatially and temporally averaged by local circulations. Finally, the third component (3.5%) is attributed to short-lived plumes containing high ozone originating from industrial areas along Galveston Bay and the Houston Ship Channel. Regional background ozone concentrations derived using the first component compare well with mean ozone concentrations measured above the Gulf of Mexico by the tunable profiler for aerosols and ozone lidar aboard the NOAA Twin Otter. The PCA regional background values also agree well with background values derived using the lowest daily 8-h maximum method of Nielsen-Gammon et al. (2005), provided the Galveston Airport data (C34) are omitted from that analysis. The differences found when Galveston is included are caused by the sea breeze, which depresses ozone at Galveston relative to sites further inland. PCA removes the effects of this and other local circulations to obtain a regional background value representative of the greater Houston area.

Inner filter effect and the onset of concentration dependent red shift of synchronous fluorescence spectra.

PubMed

Tarai, Madhumita; Mishra, Ashok Kumar

2016-10-12

The phenomenon of concentration dependent red shift, often observed in synchronous fluorescence spectra (SFS) of monofluorophoric as well as multifluorophoric systems at high chromophore concentrations, is known to have good analytical advantages. This was previously understood in terms of large inner filter effect (IFE) through the introduction of a derived absorption spectral profile that closely corresponds to the SFS profile. Using representative monofluorophoric and multifluorophoric systems, it is now explained how the SF spectral maximum changes with concentration of the fluorophore. For dilute solutions of monofluorophores the maximum is unchanged as expected. It is shown here that the onset of red shift of SFS maximum of both the mono as well as the multifluorophoric systems must occur at the derived absorption spectral parameter value of 0.32 that corresponds to the absorbance value of 0.87. This value is unique irrespective of the nature of the fluorophore under study. For monofluorophoric systems, the wavelength of derived absorption spectral maximum and the wavelength of synchronous fluorescence spectral maximum closely correspond with each other in the entire concentration range. In contrast, for multifluorophoric systems like diesel and aqueous humic acid, large deviations were noted that could be explained as to be due to the presence of non-fluorescing chromophores in the system. This work bridges the entire fluorophore concentration range over which the red shift of SFS maximum sets in; and in the process it establishes the importance of the derived absorption spectral parameter in understanding the phenomenon of concentration dependent red shift of SFS maximum. Copyright © 2016 Elsevier B.V. All rights reserved.

Values, Attitudes Toward Interpersonal Violence, and Interpersonal Violent Behavior

PubMed Central

Seddig, Daniel; Davidov, Eldad

2018-01-01

The relevance of human values for the study of the motivational sources of interpersonal violent behavior was investigated in various fields of the social sciences. However, several past studies mixed up values with other dimensions like attitudes, norms, or beliefs, and only a few systematically assessed the effect of values on violent behavior relying on a value theory. Furthermore, in other studies, violence was often analyzed as a composite index of different forms of delinquent behavior rather than as violence per se. In the current study we address these gaps in the literature by building upon Schwartz’ theory of basic human values. We use it to explain attitudes toward interpersonal violence and interpersonal violent behavior. We analyze data of young people (n = 1,810) drawn from a German study in Duisburg, Germany, which assessed various types of self-reported violent behavior as well as values and attitudes toward violence. We test structural equation models in which we explain interpersonal violent behavior with basic human values, and where attitudes toward interpersonal violent behavior mediate this relation. Results show that self-transcendence and conservation values are associated negatively and power and stimulation values positively with interpersonal violent behavior. In addition, attitudes operate as a partial mediator for the former and as a full mediator for the latter in the relation between values and violent behavior. Despite a dominant association between attitudes and behavior, values themselves can significantly contribute to the explanation of violent behavior. PMID:29867623

Values, Attitudes Toward Interpersonal Violence, and Interpersonal Violent Behavior.

PubMed

Seddig, Daniel; Davidov, Eldad

2018-01-01

The relevance of human values for the study of the motivational sources of interpersonal violent behavior was investigated in various fields of the social sciences. However, several past studies mixed up values with other dimensions like attitudes, norms, or beliefs, and only a few systematically assessed the effect of values on violent behavior relying on a value theory. Furthermore, in other studies, violence was often analyzed as a composite index of different forms of delinquent behavior rather than as violence per se . In the current study we address these gaps in the literature by building upon Schwartz' theory of basic human values. We use it to explain attitudes toward interpersonal violence and interpersonal violent behavior. We analyze data of young people ( n = 1,810) drawn from a German study in Duisburg, Germany, which assessed various types of self-reported violent behavior as well as values and attitudes toward violence. We test structural equation models in which we explain interpersonal violent behavior with basic human values, and where attitudes toward interpersonal violent behavior mediate this relation. Results show that self-transcendence and conservation values are associated negatively and power and stimulation values positively with interpersonal violent behavior. In addition, attitudes operate as a partial mediator for the former and as a full mediator for the latter in the relation between values and violent behavior. Despite a dominant association between attitudes and behavior, values themselves can significantly contribute to the explanation of violent behavior.

Moisture Management for High R-Value Walls

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

Lepage, R.; Schumacher, C.; Lukachko, A.

2013-11-01

The following report explains the moisture-related concerns for High R-value wall assemblies and discusses past Building America research work that informs this study. Hygrothermal simulations were prepared for several common approaches to High R-value wall construction in six cities (Houston, Atlanta, Seattle, St. Louis, Chicago, and International Falls) representing a range of climate zones (2, 3, 4C, 4, 5A, and 7, respectively). The simulations are informed by experience gained from past research in this area and validated by field measurement and forensic experience. The modeling program was developed to assess the moisture durability of the wall assemblies based on threemore » primary sources of moisture: construction moisture, air leakage condensation, and bulk water leakage. The peak annual moisture content of the wood based exterior sheathing was used to comparatively analyze the response to the moisture loads for each of the walls in each given city. Walls which experienced sheathing moisture contents between 20% and 28% were identified as risky, whereas those exceeding 28% were identified as very high risk. All of the wall assemblies perform well under idealized conditions. However, only the walls with exterior insulation, or cavity insulation which provides a hygrothermal function similar to exterior insulation, perform adequately when exposed to moisture loads. Walls with only cavity insulation are particularly susceptible to air leakage condensation. None of the walls performed well when a precipitation based bulk water leak was introduced to the backside of the sheathing, emphasizing the importance of proper flashing details.« less

Paleoenvironmental reconstruction of a saline lake in the Tertiary: Evidence from aragonite laminae in the northern Tibet Plateau

NASA Astrophysics Data System (ADS)

Ma, Jian; Wu, Chaodong; Wang, Yizhe; Wang, Jialin; Fang, Yanan; Zhu, Wen; Zhai, Lina; Zhou, Tianqi

2017-05-01

The origin of aragonite has long been debated because it is precipitated and preserved under specific conditions. Aragonite laminae, first found from Eocene to Miocene strata in the western Qaidam Basin, northern Tibet Plateau, contain much information on paleolake signatures. Mineralogical and geochemical analyses were conducted on alternating yellowish and grayish aragonite layers. The yellowish layers are mainly composed of aragonite crystals, while the grayish layers contain less aragonite and fewer organic remnants that accumulate among debris with sporadic framboidal pyrite. The δ13C values of yellowish layers are remarkably positive by approximately 4.01‰ (VPDB), and the δ18O values are slightly negative compared with base data of the Qaidam Basin. Considering the 12CO2 absorption of algal blooms, positive excursions of δ13C shown in aragonite indicate high 13C values in depositional water. Therefore, a seasonal algal-influenced inorganic origin is proposed to explain the formation of aragonite laminae. During warm seasons, Mg/Ca ratios are elevated because of evaporation effects. The algal blooms decrease the CO2 content, leading to high pH values. These conditions promote the rapid crystal growth of aragonite instead of other carbonate minerals. Slightly negative δ18O values in yellowish layers are interpreted as the result of intense inflow during warm seasons, which leads to less precipitation of organic matter and debris. The grayish layers in cold seasons are the opposite. From the Eocene to Oligocene, the progressively decreasing δ18O values of aragonite reflect global cooling during this time. A conspicuously positive step in δ18O values indicates an arid environment coinciding with the uplift of the Himalaya, from the Oligocene to Lower Miocene. The results from this study show that understanding of aragonite in the Qaidam Basin is essential to reconstruct the high-resolution paleoenvironment and to reveal the Tertiary evolution of paleoclimates in the northern Tibet Plateau.

When performance-approach goals predict academic achievement and when they do not: a social value approach.

PubMed

Dompnier, Benoît; Darnon, Céline; Butera, Fabrizio

2013-09-01

Research on achievement goal promotion at University has shown that performance-approach goals are perceived as a means to succeed at University (high social utility) but are not appreciated (low social desirability). We argue that such a paradox could explain why research has detected that performance-approach goals consistently predict academic grades. First-year psychology students answered a performance-approach goal scale with standard, social desirability and social utility instructions. Participants' grades were recorded at the end of the semester. Results showed that the relationship between performance-approach goals and grades was inhibited by the increase of these goals' social desirability and facilitated by the increase of their social utility, revealing that the predictive validity of performance-approach goals depends on social value. © 2013 The British Psychological Society.

Dependences of contraction/expansion of stacking faults on temperature and current density in 4H-SiC p–i–n diodes

NASA Astrophysics Data System (ADS)

Okada, Aoi; Nishio, Johji; Iijima, Ryosuke; Ota, Chiharu; Goryu, Akihiro; Miyazato, Masaki; Ryo, Mina; Shinohe, Takashi; Miyajima, Masaaki; Kato, Tomohisa; Yonezawa, Yoshiyuki; Okumura, Hajime

2018-06-01

To investigate the mechanism of contraction/expansion behavior of Shockley stacking faults (SSFs) in 4H-SiC p–i–n diodes, the dependences of the SSF behavior on temperature and injection current density were investigated by electroluminescence image observation. We investigated the dependences of both triangle- and bar-shaped SSFs on the injection current density at four temperature levels. All SSFs in this study show similar temperature and injection current density dependences. We found that the expansion of SSFs at a high current density was converted to contraction at a certain value as the current decreased and that the value is temperature-dependent. It has been confirmed that SSF behavior, which was considered complex or peculiar, might be explained mainly by the energy change caused by SSFs.

Bright color optical switching device by polymer network liquid crystal with a specular reflector.

PubMed

Lee, Gae Hwang; Hwang, Kyu Young; Jang, Jae Eun; Jin, Yong Wan; Lee, Sang Yoon; Jung, Jae Eun

2011-07-04

The color optical switching device by polymer network liquid crystal (PNLC) with color filter on a specular reflector shows excellent performance; white reflectance of 22%, color gamut of 32%, and contrast ratio up to 50:1 in reflective mode measurement. The view-angle dependence of the reflectance can be adjusted by changing the PNLC thickness. The color chromaticity shown by the device is close to the limit value of color filters, and its value nearly remains with respect to the operating voltage. These optical properties of the device can be explained from the prediction based on multiple interactions between the light and the droplets of liquid crystal. The high reflectance, vivid color image, and moderate responds time allow the PNLC device to drive good color moving image. It can widely extend the applications of the reflective device.

Working memory and spatial judgments: Cognitive load increases the central tendency bias.

PubMed

Allred, Sarah R; Crawford, L Elizabeth; Duffy, Sean; Smith, John

2016-12-01

Previous work demonstrates that memory for simple stimuli can be biased by information about the distribution of which the stimulus is a member. Specifically, people underestimate values greater than the distribution's average and overestimate values smaller than the average. This is referred to as the central tendency bias. This bias has been explained as an optimal use of both noisy sensory information and category information. In largely separate literature, cognitive load (CL) experiments attempt to manipulate the available working memory of participants in order to observe the effect on choice or judgments. In two experiments, we demonstrate that participants under high cognitive load exhibit a stronger central tendency bias than when under a low cognitive load. Although not anticipated at the outset, we also find that judgments exhibit an anchoring bias not described previously.

Natural Selection, Childrearing, and the Ethics of Marriage (and Divorce): Building a Case for the Neuroenhancement of Human Relationships.

PubMed

Earp, Brian D; Sandberg, Anders; Savulescu, Julian

2012-12-01

We argue that the fragility of contemporary marriages-and the corresponding high rates of divorce-can be explained (in large part) by a three-part mismatch: between our relationship values, our evolved psychobiological natures, and our modern social, physical, and technological environment. "Love drugs" could help address this mismatch by boosting our psychobiologies while keeping our values and our environment intact. While individual couples should be free to use pharmacological interventions to sustain and improve their romantic connection, we suggest that they may have an obligation to do so as well, in certain cases. Specifically, we argue that couples with offspring may have a special responsibility to enhance their relationships for the sake of their children. We outline an evolutionarily informed research program for identifying promising biomedical enhancements of love and commitment.

Programmable Gain Amplifiers with DC Suppression and Low Output Offset for Bioelectric Sensors

PubMed Central

Carrera, Albano; de la Rosa, Ramón; Alonso, Alonso

2013-01-01

DC-offset and DC-suppression are key parameters in bioelectric amplifiers. However, specific DC analyses are not often explained. Several factors influence the DC-budget: the programmable gain, the programmable cut-off frequencies for high pass filtering and, the low cut-off values and the capacitor blocking issues involved. A new intermediate stage is proposed to address the DC problem entirely. Two implementations were tested. The stage is composed of a programmable gain amplifier (PGA) with DC-rejection and low output offset. Cut-off frequencies are selectable and values from 0.016 to 31.83 Hz were tested, and the capacitor deblocking is embedded in the design. Hence, this PGA delivers most of the required gain with constant low output offset, notwithstanding the gain or cut-off frequency selected. PMID:24084109

Cationic composition and acid-base state of the extracellular fluid, and specific buffer value of hemoglobin from the branchiopod crustacean Triops cancriformis.

PubMed

Pirow, Ralph; Buchen, Ina; Richter, Marc; Allmer, Carsten; Nunes, Frank; Günsel, Andreas; Heikens, Wiebke; Lamkemeyer, Tobias; von Reumont, Björn M; Hetz, Stefan K

2009-04-01

Recent insights into the allosteric control of oxygen binding in the extracellular hemoglobin (Hb) of the tadpole shrimp Triops cancriformis raised the question about the physico-chemical properties of the protein's native environment. This study determined the cationic composition and acid-base state of the animal's extracellular fluid. The physiological concentrations of potential cationic effectors (calcium, magnesium) were more than one order of magnitude below the level effective to increase Hb oxygen affinity. The extracellular fluid in the pericardial space had a typical bicarbonate concentration of 7.6 mM but a remarkably high CO(2) partial pressure of 1.36 kPa at pH 7.52 and 20 degrees C. The discrepancy between this high CO(2) partial pressure and the comparably low values for water-breathing decapods could not solely be explained by the hemolymph-sampling procedure but may additionally arise from differences in cardiovascular complexity and efficiency. T. cancriformis hemolymph had a non-bicarbonate buffer value of 2.1 meq L(-1) pH(-1). Hb covered 40-60% of the non-bicarbonate buffering power. The specific buffer value of Hb of 1.1 meq (mmol heme)(-1) pH(-1) suggested a minimum requirement of two titratable histidines per heme-binding domain, which is supported by available information from N-terminal sequencing and expressed sequence tags.

Three-dimensional fluid mapping and earthquake probabilities for induced seismicity sequences

NASA Astrophysics Data System (ADS)

Bachmann, C. E.; Wiemer, S.; Woessner, J.

2010-12-01

To stimulate the reservoir for a proposed enhanced geothermal system (EGS) project in the City of Basel, approximately 11500 m3 of water were injected at high pressures into a 5 km deep well between December 2nd and 8th, 2006. A six-sensor borehole array, installed by Geothermal Explorers Limited at depths between 50 and 2700 meters around the well to monitor the induced seismicity, recorded some 15000 events during the injection phase, more than 3500 of them locatable. The induced seismicity covers an area of about two square kilometers between 3 and 5 km depth. Water injection was stopped after a widely felt ML 3.4 event that occurred on December 8th. Here, we map in space and time statistical parameters that describe the seismicity, such as the magnitude of completeness, Mc the b- and a- value of the frequency-magnitude distribution and the local probability of large events. We find that the completeness level varies from Mc= 0.5 to Mc=0.8, where the lowest completeness is observed for the shallowest seismicity. Higher b-values are located close to the initiation point of the injection at the casing shoe. With time, and with the gradual expansion of the seismicity, the b-values decrease near the edges of the seismicity cloud. The b-values range from 1.0 to above 2.0; large events occur preferentially in regions of previously low b-value. The local earthquake probabilities for a larger (M3+) event determined from the local a- and b-value show a clear correlation with the occurrence of events in this magnitude range, suggesting that by mapping the local a- and b-values, large magnitude events could be forecasted with greater accuracy than possible when using bulk values only. There are several different hypotheses how to explain induced seismicity, including increasing pore pressure, temperature decrease, volume changes and chemical alterations of fraction surfaces. All of these are linked to the fluid migration within the rock. Previously, high b-values have been shown to correlate with the presence of magma and fluids in volcanic areas and subduction zones. Additionally, b-values have been shown to be inversely proportional to the applied shear stress. Our results indicate that often-stated assumption that induced sequences are showing a high b-value is too simplistic. Rather, anomalously high values close to the casing shoe are embedded in average values further away. These zones of high b-values experience the highest changes in pore pressure, we therefore suggest a correlation between b-values and pore pressure. Towards the rim of seismicity, we find lower b-values, close to typical tectonic values, indicating that the seismicity may not primarily be caused by fluid overpressure. Based on our results, we suggest that b-values are linked to fluid migration; zones with high b-values indicate preferential fluid flow directions, zones with low b-values suggest seismicity that is not directly linked to water flow.

Dynamic divisive normalization predicts time-varying value coding in decision-related circuits.

PubMed

Louie, Kenway; LoFaro, Thomas; Webb, Ryan; Glimcher, Paul W

2014-11-26

Normalization is a widespread neural computation, mediating divisive gain control in sensory processing and implementing a context-dependent value code in decision-related frontal and parietal cortices. Although decision-making is a dynamic process with complex temporal characteristics, most models of normalization are time-independent and little is known about the dynamic interaction of normalization and choice. Here, we show that a simple differential equation model of normalization explains the characteristic phasic-sustained pattern of cortical decision activity and predicts specific normalization dynamics: value coding during initial transients, time-varying value modulation, and delayed onset of contextual information. Empirically, we observe these predicted dynamics in saccade-related neurons in monkey lateral intraparietal cortex. Furthermore, such models naturally incorporate a time-weighted average of past activity, implementing an intrinsic reference-dependence in value coding. These results suggest that a single network mechanism can explain both transient and sustained decision activity, emphasizing the importance of a dynamic view of normalization in neural coding. Copyright © 2014 the authors 0270-6474/14/3416046-12$15.00/0.

Origin of high open-circuit voltage in a planar heterojunction solar cell containing a non-fullerene acceptor

NASA Astrophysics Data System (ADS)

Cheng, Nongyi; Peng, Yuelin; Andrew, Trisha L.

2017-09-01

Vapor-deposited, planar heterojunction organic solar cells containing a periflanthene donor and either a fullerene or non-fullerene acceptor are investigated. A high VOC of 1.16 V is observed in devices containing the non-fullerene, pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(4-chlorophenyl)-2,5-dihydro acceptor, whereas analogous devices containing C60 only result in a VOC of 0.8 V. The measured band energy levels of the two different acceptors do not readily explain the observed difference. Small-perturbation transient photovoltage and transient photocurrent measurements reveal that interfacial charge recombination is comparatively slower for the non-fullerene acceptor, resulting in relatively higher Voc values.

Prosocial motivation and physicians' work attitudes. Effects of a triple synergy on prosocial orientation in a healthcare organization.

PubMed

Kim, Young Shin

2015-01-01

Employees work attitudes are key determinants to organizational performance. This article proposes a model integrating servant leadership, prosocial motivation, and corporate social responsibility (CSR) in order to explain a mechanism through which prosocial motivation plays a central role in enhanding physicians' work attitudes. A cross sectional survey from a sample of physicians indicates that (1) prosocial motivation can be shaped from servant leadership when physicians perceive high value fit with their supervisors, (2) prosocial motivation improves physicians' job satisfaction. Its effects is strengthened when physicians perceive high CSR, and (3) job satisfaction improves organizational commitment. The results provide meaningful insights that a triple synergy of prosocial orientation among physicians, supervisors and organization enhances physicians' work attitudes.

High tolerance to high-light conditions for the protected species Ariocarpus kotschoubeyanus (Cactaceae)

PubMed Central

Arroyo-Pérez, Erika; González-Salvatierra, Claudia; Matías-Palafox, María L.; Jiménez-Sierra, Cecilia

2017-01-01

Abstract We determined the seasonal ecophysiological performance under perennial plants and under high solar radiation for adult individuals from the ‘living rock’ cactus Ariocarpus kotschoubeyanus, which occurs equally under nurse plants and in open spaces. We evaluated the effective quantum yield of photosystem II (ΦPSII) and the dissipation of thermal energy [non-photochemical quenching (NPQ)] thorough the year. The maximum apparent electron transport rate (ETRmax) and the saturating photosynthetically active photon flux density for PSII (PFDsat) were also determined from rapid light curves. We found that although the ΦPSII was higher in shaded sites under potential nurse plants than in exposed sites, all values were close to the optimal value of 0.83. The high ΦPSII found for A. kotschoubeyanus plants suggests that they use a great proportion of the absorbed light for photosynthesis, under nurse plants as well as in open spaces. We also found higher NPQ values in exposed sites than in shaded ones but only in Autumn, thus reducing the risk of photoinhibition. In addition, the PFDsat was higher in exposed sites than in shaded ones in Spring, Summer and Autumn, but in Winter there were no differences between treatments. We also found high saturating light levels for ETR (PFDsat higher than 1378 μmol m−2 s−1) in all seasons but in winter for shaded and non-shaded plants. Our findings indicate that A. kotschoubeyanus plants use a great proportion of the light that they absorb for photosynthesis. This high tolerance to high-light conditions could explain why A. kotschoubeyanus do not show preferences for protected sites under nurse plants. PMID:28729902

15N and 13C abundances in the Antartic Ocean with emphasis on the biogeochemical structure of the food web

NASA Astrophysics Data System (ADS)

Wada, Eitaro; Terazaki, Makoto; Kabaya, Yuko; Nemoto, Takahisa

1987-06-01

Distributions of δ 15N and δ 13C for biogenic substances in the Antarctic Ocean were investigated to construct a biogeochemical framework for assessing the Antarctic ecosystem. Phytoplankton exhibited particularly low δ 15N (0.5%) and 13C (-26.9%) values in pelagic plankton samples. High nitrate concentrations, and high PCO 2 in the surface waters on the southern side of the polar front and the resulting slow growth rate of phytoplankton under low light intensity are suggested as possible factors in causing the low isotopic compositions. Mean fractionation factors of 1.029 and 1.006 were estimated for photosynthetic carbon fixation and for the assimilation of inorganic nitrogeneous compounds (ammonium plus nitrate) during algal growth, respectively. Enrichment of 15N with increasing trophic level was confirmed for Antarctic ecosystems: δ15N animal% = 3.3 (trophic level -1) + δ5N algae, whereas 13C content did not increase in the same manner. Differences in lipid content among animals may be the main factor in causing this δ 13C anomaly. 15N and 13C abundance of sedimentary organic nitrogen differed from phytoplankton and settling particles. An exact mechanism for explaining the high δ 15N (around 5%) is not known. The very high δ 13C value of -20.5% at Sta. 3B may originate in ice algae that had grown under CO 2-limited conditions. Particles collected by sediment traps gave characteristically low δ 15N values (-3.0 to 0.9%), strongly suggesting a phytoplankton origin. The δ 15N and δ 13C values of settling material showed similar vertical profiles with depth which might arise from temporal variation of algal growth.

CO2 outgassing in a combined fracture and conduit karst aquifer near lititz spring, Pennsylvania

USGS Publications Warehouse

Toran, L.; Roman, E.

2006-01-01

Lititz Spring in southeastern Pennsylvania and a nearby domestic well were sampled for 9 months. Although both locations are connected to conduits (as evidenced by a tracer test), most of the year they were saturated with respect to calcite, which is more typical of matrix flow. Geochemical modeling (PHREEQC) was used to explain this apparent paradox and to infer changes in matrix and conduit contribution to flow. The saturation index varied from 0.5 to 0 most of the year, with a few samples in springtime dropping below saturation. The log PCO2 value varied from -2.5 to -1.7. Lower log PCO2 values (closer to the atmospheric value of -3.5) were observed when the solutions were at or above saturation with respect to calcite. In contrast, samples collected in the springtime had high PCO2, low saturation indices, and high water levels. Geochemical modeling showed that when outgassing occurs from a water with initially high PCO2, the saturation index of calcite increases. In the Lititz Spring area, the recharge water travels through the soil zone, where it picks up CO2 from soil gas, and excess CO 2 subsequently is outgassed when this recharge water reaches the conduit. At times of high water level (pipe full), recharge with excess CO 2 enters the system but the outgassing does not occur. Instead the recharge causes dilution, reducing the calcite saturation index. Understanding the temporal and spatial variation in matrix and conduit flow in karst aquifers benefited here by geochemical modeling and calculation of PCO2 values. ?? 2006 Geological Society of America.

Properties of 5052 Aluminum For Use as Honeycomb Core in Manned Spaceflight

NASA Technical Reports Server (NTRS)

Lerch, Bradley A.

2018-01-01

This work explains that the properties of Al 5052 material used commonly for honeycomb cores in sandwich panels are highly dependent on the tempering condition. It has not been common to specify the temper when ordering HC material nor is it common for the supplier to state what the temper is. For aerospace uses, a temper of H38 or H39 is probably recommended. This temper should be stated in the bill of material and should be verified upon receipt of the core. To this end some properties provided herein can aid as benchmark values.

Nuclear clustering and the electron screening puzzle

NASA Astrophysics Data System (ADS)

Bertulani, C. A.; Spitaleri, C.

2018-01-01

Electron screening changes appreciably the magnitude of astrophysical nuclear reactions within stars. This effect is also observed in laboratory experiments on Earth, where atomic electrons are present in the nuclear targets. Theoretical models were developed over the past 30 years and experimental measurements have been carried out to study electron screening in thermonuclear reactions. None of the theoretical models were able to explain the high values of the experimentally determined screening potentials. We explore the possibility that the "electron screening puzzle" is due to nuclear clusterization and polarization e_ects in the fusion reactions. We will discuss the supporting arguments for this scenario.

Further validation of the Maudsley Marital Questionnaire (MMQ).

PubMed

Joseph, Orathinkal; Alfons, Vansteenwegen; Rob, Stroobants

2007-05-01

This study examined the Factor structure and internal consistency of the Dutch version of the Maudsley Marital Questionnaire (MMQ) for a sample of 787 respondents in Belgium. Principal components analysis, followed by varimax orthogonal rotation, identified the expected three factors (M - Marital, S - Sexual, GL - General Life), which jointly explained 53% of the variance. The Cronbach alpha for MMQ - M (.90) and MMQ - S (.80) were of high value while for MMQ - GL (.66) was lower. The MMQ scales were found significantly correlated with each other: M - S, .60; M - GL, .46 and S - GL, .33.

High-frequency magnetodielectric response in yttrium iron garnet at room temperature

NASA Astrophysics Data System (ADS)

Zhu, Jie; Liu, Yuan; Jia, Longfei; Zhang, Baoshan; Yang, Yi; Tang, Dongming

2018-05-01

Magnetic and dielectric properties of Yttrium Iron Garnet are measured over a frequency ranging from 0.5 GHz to 10 GHz with a magnetic field applied parallel to the propagation direction of the microwave. At the same time, the magnetodielectric phenomena are detected quantitatively. The maximum amplitude of the magnetodielectric coefficient is acquired at the ferromagnetic resonance frequency, and the value is up to 1.2% with the magnetic field of 1500 Oe applied. The phenomena have been explained by the Faraday's electromagnetic induction of the precession of the magnetic moments in the electromagnetic field at the ferromagnetic resonance frequency.

30 CFR 1206.112 - What adjustments and transportation allowances apply when I value oil production from my lease...

Code of Federal Regulations, 2011 CFR

2011-07-01

... representative crude oil at the market center after making the quality adjustments described in paragraphs (a... in value between your lease and the appropriate ONRR-recognized market center at which the ANS spot... this section explains how you adjust the value between the lease and the market center, and paragraph...

Leading Change, Adding Value.

PubMed

Evans, Nick

2016-07-06

Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It builds on Compassion in Practice (CiP), which set out the 6Cs. While CiP established the values of nursing and midwifery, the new framework explains how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View.

Common pitfalls in statistical analysis: “P” values, statistical significance and confidence intervals

PubMed Central

Ranganathan, Priya; Pramesh, C. S.; Buyse, Marc

2015-01-01

In the second part of a series on pitfalls in statistical analysis, we look at various ways in which a statistically significant study result can be expressed. We debunk some of the myths regarding the ‘P’ value, explain the importance of ‘confidence intervals’ and clarify the importance of including both values in a paper PMID:25878958

Geodiversity and Geoheritage: definitions, values and conservation

NASA Astrophysics Data System (ADS)

Gray, Murray

2016-04-01

Geodiversity is the abiotic equivalent of biodiversity, i.e. it describes the variety of physical processes operating on planet Earth and the resultant rocks, minerals, fossils, sediments, soils, landforms, landscapes and habitats found on the planet today. Just as biodiversity is valued, in the "ecosystem services" approach, for the benefits it brings to human societies, so geodiversity brings a great number of goods and services that have been brilliantly exploited by humans over countless generations. In fact, our modern, complex society could not exist without geodiversity. Geoheritage are those parts of geodiversity that are specifically identified as having conservation significance, i.e. that have some specific value to human society and therefore ought to be conserved, particularly if they are threatened by human activities and could therefore be lost or damaged. Geoheritage is often seen as being about identifying and designating sites that have geoscientific value, but it can represent other values and be on scales larger than small sites. This presentation will attempt to define geodiversity and geoheritage and explain the relationship between them, outline that values of geodiversity in terms of the "ecosystem services" approach, and explain how geodiversity and geoheritage can be protected by geoconservation methods.

An Overview of Environmental Attitudes, Values, and Ethics: A Symposium.

ERIC Educational Resources Information Center

1974

This series of symposium papers examines the phenomena of environmental attitudes, values, and ethics from a psychological, philosophical/religious, and Western religion perspective. The psychological view is examined from three standpoints: the internalist position, explaining behavior from events within the individual; the interactionist…

Explaining attitudes about homosexuality in Confucian and non-Confucian nations: is there a 'cultural' influence?

PubMed

Adamczyk, Amy; Cheng, Yen-hsin Alice

2015-05-01

The majority of research on attitudes about homosexuality has concentrated on the global North and on Christian and Muslim majority nations. Little research attention has been given to the factors that shape tolerance in societies with a Confucian heritage. Residents of Confucian counties are less tolerant than Europeans and Americans. One reason given for this difference is the emphasis on Confucian values in many Asian societies. Using data from the World Values Survey, we examine whether values that could be described as Confucian influence attitudes in Confucian and non-Confucian nations. We find a unique Confucian cultural effect, which can partially be explained with concerns about keeping the family intact. Conversely, in Confucian societies values related to obedience, conformity, and filial piety are unrelated to attitudes. There is also a small Buddhist contextual effect, resulting in more tolerant attitudes, and the Confucian influence cannot be reduced to an Asian regional effect. Published by Elsevier Inc.

Effects of oxygen deficiency on the transport and dielectric properties of NdSrNbO

NASA Astrophysics Data System (ADS)

Hzez, W.; Benali, A.; Rahmouni, H.; Dhahri, E.; Khirouni, K.; Costa, B. F. O.

2018-06-01

In the present study, Nd0.7Sr0.3NbO3-y (y = 0.1, 0.15, 0.2) compounds were prepared via a solid-solid reaction route. The prepared samples were characterized by electrochemical impedance spectroscopy in order to establish the effects of temperature, frequency, and oxygen vacancies on both the transport and dielectric properties of NdSrNbO. We found that both the electrical and dielectric properties were highly sensitive to the concentration of oxygen vacancies. The conduction mechanism data were explained well according to the Mott model and adiabatic small polaronic hopping model. Electrochemical impedance spectroscopy analysis showed that one relaxation process was present in the Nd0.7Sr0.3NbO2.9 system whereas two relaxation processes were observed in the Nd0.7Sr0.3NbO2.85 and Nd0.7Sr0.3NbO2.8 systems, where the latter behavior indicated the presence of many active regions (due to the contributions of different microstructures). The temperature and frequency dependences of the dielectric constant confirmed the contributions of different polarization mechanisms. In particular, the high dielectric constant values at low frequencies and high temperatures were mainly related to the presence of different Schottky barriers, whereas the low dielectric constant values at high frequencies were essentially related to the intrinsic effect. The constant dielectric values obtained for the samples are greater than those in the NdSrFeO system, which makes them interesting materials for use in applications that require high dielectric constants.

Explaining variability in first grazing season heifer growth combining individually measured parasitological and clinical indicators with exposure to gastrointestinal nematode infection based on grazing management practice.

PubMed

Merlin, Aurélie; Chauvin, Alain; Madouasse, Aurélien; Froger, Sébastien; Bareille, Nathalie; Chartier, Christophe

2016-07-30

The objective of our study was to explain the variability of average daily weight gain (ADWG) due to gastrointestinal nematode (GIN) infection for 291 non treated first grazing season (FGS) heifers, from 12 independent groups in the western part of France, by combining parasitological and clinical indicators at individual level and grazing management indicators at group level. Parasitological indicators were faecal egg count (FEC), anti Ostertagia ostertagi antibody level (Ostertagia ODR), and pepsinogen level. Clinical indicators were diarrhea score (DISCO) and breech soiling score (BSS). At group level, grazing management practice (GMP), based on three variables (supplementation, month of turnout, grazing season duration), was clustered into three categories reflecting low, medium or high exposure (EXP) to GIN. Depending on the groups, turnout was from mid-March to early July and housing was from mid-October to late November, with a FGS duration ranging from 4 to 8.4 months. At turnout, the mean age of heifers was 8 months (range: 6-16 months) and they weighed between 175 and 268kg. In each GMP category, FEC significantly decreased between the mid-season and the housing, while Ostertagia ODR and pepsinogen level increased gradually throughout the grazing season. In contrast, clinical indicators did not show any seasonal variation. In a multivariate linear model, 22% of the ADWG variability was significantly explained by two individual indicators (Ostertagia ODR: 12.6%, DISCO: 4.8%) and by the group indicator (GMP category: 4.8%). ADWG losses due to GIN exposure (Ostertagia ODR) were estimated up to 39kg per heifer for the overall grazing season. For groups within the low EXP category the difference between animals with low (<697g/day) or high (>697g/day) ADWG was explained by the clinical indicator DISCO. In contrast, for groups within the medium and high EXP categories this difference was explained by a parasitological indicator (Ostertagia ODR). This study highlighted the value of combining both grazing management (group level) and parasitological (individual level) indicators to assess the impact of GIN on ADWG of FGS heifers. As a result, this combination might allow a better discrimination of animals or groups that may be in need of treatment in a targeting selective treatment approach. Copyright © 2016 Elsevier B.V. All rights reserved.

Relational values resonate broadly and differently than intrinsic or instrumental values, or the New Ecological Paradigm

PubMed Central

Chan, Kai M. A.; Satterfield, Terre

2017-01-01

Value orientations used to explain or justify conservation have been rooted in arguments about how much and in what context to emphasize the intrinsic versus instrumental value of nature. Equally prominent are characterizations of beliefs known as the New Ecological Paradigm (NEP), often used to help explain pro-environmental behaviour. A recent alternative to these positions has been identified as ‘relational value’—broadly, values linking people and ecosystems via tangible and intangible relationships to nature as well as the principles, virtues and notions of a good life that may accompany these. This paper examines whether relational values are distinct from other value orientation and have potential to alleviate the intrinsic-instrumental debate. To test this possibility, we sought to operationalize the construct—relational values—by developing six relational statements. We ask: 1) Do the individual statements used to characterize relational values demonstrate internal coherence as either a single or multi-dimensional construct? 2) Do relational value statements (including those strongly stated) resonate with diverse populations? 3) Do people respond to relational value statements in a consistently different way than NEP scale statements? Data for this work is drawn from an online panel of residents of northeastern US (n = 400), as well as a sample of Costa Rican farmers (n = 253) and tourists in Costa Rica (n = 260). Results indicate relational values are distinct as a construct when compared to the NEP. PMID:28854227

The role of attitudes about vaccine safety, efficacy, and value in explaining parents' reported vaccination behavior.

PubMed

Lavail, Katherine Hart; Kennedy, Allison Michelle

2013-10-01

To explain vaccine confidence as it related to parents' decisions to vaccinate their children with recommended vaccines, and to develop a confidence measure to efficiently and effectively predict parents' self-reported vaccine behaviors. A sample of parents with at least one child younger than 6 years (n = 376) was analyzed using data from the HealthStyles 2010 survey. Questions were grouped into block variables to create three confidence constructs: value, safety, and efficacy. Regression equations controlling for demographic characteristics were used to identify the confidence construct(s) that best predicted parents' self-reported vaccination decisions (accept all, some, or none of the recommended childhood vaccines). Among the three constructs evaluated, confidence in the value of vaccines, that is the belief that vaccines are important and vaccinating one's children is the right thing to do, was the best predictor of parents' vaccine decisions, F(2, 351) = 119.199, p < .001. When combined into a block variable for analysis, two survey items measuring confidence in the value of vaccines accounted for 40% of the variance in parents' self-reported vaccine decisions. Confidence in the safety or efficacy of vaccines failed to account for additional significant variance in parent-reported vaccination behavior. Confidence in the value of vaccines is a helpful predictor of parent-reported vaccination behavior. Attitudinal constructs of confidence in the safety and efficacy of vaccines failed to account for additional significant variance in parents' vaccination behaviors. Future research should assess the role of vaccine knowledge and tangible barriers, such as access and cost, to further explain parents' vaccination behaviors.

Chemical characteristics of urban stormwater sediments and implications for environmental management, Maricopa County, Arizona

USGS Publications Warehouse

Parker, J.T.C.; Fossum, K.D.; Ingersoll, T.L.

2000-01-01

Investigations of the chemical characteristics of urban stormwater sediments in the rapidly growing Phoenix metropolitan area of Maricopa County, Arizona, showed that the inorganic component of these sediments generally reflects geologic background values. Some concentrations of metals were above background values, especially cadmium, copper, lead, and zinc, indicating an anthropogenic contribution of these elements to the sediment chemistry. Concentrations, however, were not at levels that would require soil remediation according to guidelines of the U.S. Environmental Protection Agency. Arsenic concentrations generally were above recommended values for remediation at a few sites, but these concentrations seem to reflect geologic rather than anthropogenic factors. Several organochlorine compounds no longer in use were ubiquitous in the Phoenix area, although concentrations generally were low. Chlordane, DDT and its decay products DDE and DDD, dieldrin, toxaphene, and PCBs were found at almost all sites sampled, although some of the pesticides in which these compounds are found have been banned for almost 30 years. A few sites showed exceptionally high concentrations of organochlorine compounds. On the basis of published guidelines, urban stormwater sediments do not appear to constitute a major regional environmental problem with respect to the chemical characteristics investigated here. At individual sites, high concentrations of organic compounds - chlordane, dieldrin, PCBs, and toxaphene - may require some attention. The possible environmental hazard presented by low-level organochlorine contamination is not addressed in this paper; however, high levels of toxicity in urban sediments are difficult to explain. Sediment toxicity varied significantly with time, which indicates that these tests should be evaluated carefully before they are used for management decisions.Investigations of the chemical characteristics of urban stormwater sediments in the rapidly growing Phoenix metropolitan area of Maricopa County, Arizona, showed that the inorganic component of these sediments generally reflects geologic background values. Some concentrations of metals were above background values, especially cadmium, copper, lead, and zinc, indicating an anthropogenic contribution of these elements to the sediment chemistry. Concentrations, however, were not at levels that would require soil remediation according to guidelines of the U.S. Environmental Protection Agency. Arsenic concentrations generally were above recommended values for remediation at a few sites, but these concentrations seem to reflect geologic rather than anthropogenic factors. Several organochlorine compounds no longer in use were ubiquitous in the Phoenix area, although concentrations generally were low. Chlordane, DDT and its decay products DDE and DDD, dieldrin, toxaphene, and PCBs were found at almost all sites sampled, although some of the pesticides in which these compounds are found have been banned for almost 30 years. A few sites showed exceptionally high concentrations of organochlorine compounds. On the basis of published guidelines, urban stormwater sediments do not appear to constitute a major regional environmental problem with respect to the chemical characteristics investigated here. At individual sites, high concentrations of organic compounds - chlordane, dieldrin, PCBs, and toxaphene - may require some attention. The possible environmental hazard presented by low-level organochlorine contamination is not addressed in this paper; however, high levels of toxicity in urban sediments are difficult to explain. Sediment toxicity varied significantly with time, which indicates that these tests should be evaluated carefully before they are used for management decisions.

Explaining Academic-Track Boys' Underachievement in Language Grades: Not a Lack of Aptitude but Students' Motivational Beliefs and Parents' Perceptions?

ERIC Educational Resources Information Center

Heyder, Anke; Kessels, Ursula; Steinmayr, Ricarda

2017-01-01

Background: Boys earn lower grades in languages than girls. The expectancy-value model by Eccles" et al." (1983, "A series of books in psychology. Achievement and achievement motives. Psychological and sociological approaches," W.H. Freeman, San Francisco, CA, 76) is a comprehensive theoretical model for explaining gender…

Influence of feedback characteristics on perceived learning value of feedback in clerkships: does culture matter?

PubMed

Suhoyo, Yoyo; Van Hell, Elisabeth A; Kerdijk, Wouter; Emilia, Ova; Schönrock-Adema, Johanna; Kuks, Jan B M; Cohen-Schotanus, Janke

2017-04-05

Various feedback characteristics have been suggested to positively influence student learning. It is not clear how these feedback characteristics contribute to students' perceived learning value of feedback in cultures classified low on the cultural dimension of individualism and high on power distance. This study was conducted to validate the influence of five feedback characteristics on students' perceived learning value of feedback in an Indonesian clerkship context. We asked clerks in Neurology (n = 169) and Internal Medicine (n = 132) to assess on a 5-point Likert scale the learning value of the feedback they received. We asked them to record whether the feedback provider (1) informed the student what went well, (2) mentioned which aspects of performance needed improvement, (3) compared the student's performance to a standard, (4) further explained or demonstrated the correct performance, and (5) prepared an action plan with the student to improve performance. Data were analyzed using multilevel regression. A total of 250 students participated in this study, 131 from Internal Medicine (response rate 99%) and 119 from Neurology (response rate 70%). Of these participants, 225 respondents (44% males, 56% females) completed the form and reported 889 feedback moments. Students perceived feedback as more valuable when the feedback provider mentioned their weaknesses (β = 0.153, p < 0.01), compared their performance to a standard (β = 0.159, p < 0.01), explained or demonstrated the correct performance (β = 0.324, p < 0.001) and prepared an action plan with the student (β =0.496, p < 0.001). Appraisal of good performance did not influence the perceived learning value of feedback. No gender differences were found for perceived learning value. In Indonesia, we could validate four out of the five characteristics for effective feedback. We argue that our findings relate to culture, in particular to the levels of individualism and power distance. The recognized characteristics of what constitutes effective feedback should be validated across cultures.

Anatomy of the thriple oxygen isotope Terrestrial Fractionatoin Line

NASA Astrophysics Data System (ADS)

Sharp, Z. D.; Pack, A.

2017-12-01

In the triple oxygen isotope system, it is well established that the δ17O value of nearly all terrestrial materials is approximately ½ that of the corresponding δ18O value. In triple isotope space then, all samples plot on a slope 1/2 line, termed the Terrestrial Fractionation Line (TFL). It has recently been recognized that subtle, but significant departures from the TFL exist, given by Δ'17O = δ'17O -λ× δ'18O + γ, where λ is the slope of the TFL (γ is the y-intercept and assumed to be zero in most studies). There have been many published λ values, ranging from 0.52 to 0.5305. λ values determined from a best-fit to rock and mineral samples range from 0.5244 to 0.5266. λ values from meteoric waters are 0.527 to 0.528 (γ = 0.007 to 0.034), explained by equilibrium and kinetic processes. Extreme polar glacial samples define a λ >0.53. As pointed out by Matsuhisia et al. (GCA, 1978), there is no single factor that controls the δ17O-δ18O slope, and clearly there is no `correct' TFL line. However, some generalities can be noted. 1) Meteoric waters generally plot with a λ = 0.528 with a Δ'17O = 0.033. At both high and low δ18O values, the Δ'17O values of meteoritic waters decrease. Mantle derived samples plot in a limited δ space, with δ18O values of 5-9‰ and a Δ'17O of -0.05‰. Rock and mineral samples falling outside this narrow range have undergone interaction with meteoric or ocean water at some point in their history, either by alteration or neoform mineral growth. The quartz-water triple isotope fractionation factor varies with temperatures, ranging from 0.5237 to 0.5266 at 0°C and 200°C, respective. A fit to published rock data gives an overall λ = 0.5237-0.5240. These results are most likely explained by the sum of hydrothermal and low-temperature mineral-water fractionations. Attempting to place any significance on a TFL from a set of data in unwarranted without understanding the processes controlling the isotopic compositions of the phases.

Observed fingerprint of a weakening Atlantic Ocean overturning circulation

NASA Astrophysics Data System (ADS)

Rahmstorf, S.; Caesar, L.; Feulner, G.; Robinson, A.; Saba, V. S.

2017-12-01

The overturning circulation of the Atlantic Ocean (AMOC) has a major impact on climate, yet its evolution over the past hundred years or so is poorly known for lack of direct measurements. We use a high-resolution global climate model to derive a characteristic spatial and seasonal fingerprint of AMOC changes and compare this to the observed linear temperature trend since 1870. Both the model and observations show a remarkably similar pattern of a cooling in the subpolar gyre region (most pronounced for the November to May season) and a warming in the Gulf Stream region which in their combination can only be explained by a reduction in the AMOC. We explain the mechanisms that link the pattern to an AMOC slowdown, and use an ensemble of CMIP5 simulations to calibrate the observed decline. This suggests a weakening of the AMOC by 3 Sv ( 16%) since the mid-20th Century. Its recent evolution is consistent with direct measurements in the RAPID project and reaches record low values in recent years.

A hybridization approach to efficient TiO2 photodegradation of aqueous benzalkonium chloride.

PubMed

Suchithra, Padmajan Sasikala; Carleer, Robert; Ananthakumar, Solaippan; Yperman, Jan

2015-08-15

TiO2 get positively charged upon UV-irradiation and repel the cationic pollutants away from the surface. Hybridization of AC onto TiO2 (ACT) tends catalyst surface negatively charged besides providing highly favorable adsorptions sites for cationic pollutants. The photodegradation of benzalkonium chloride (BKC), a quaternary ammonium surfactant and a pharmaceutical, is investigated with ACT. The surface charge of the catalyst in surfactant and non-surfactant aqueous dispersion under UV-irradiation is investigated and explained. The anomalous increase in COD values at the beginning of BKC-photodegradation is explained. The intermediate products formed are identified in both solution and solid phase. Trace amount of dodecane remained adsorbed on the catalyst surface after 1h UV-irradiation, but complete mineralization of BKC is achieved with 2h UV-irradiation. We propose that BKC photodegradation starts by central fission of benzyl CN bond followed by dealkylation, and demethylation steps. Copyright © 2015 Elsevier B.V. All rights reserved.

Validity of GRE General Test scores and TOEFL scores for graduate admission to a technical university in Western Europe

NASA Astrophysics Data System (ADS)

Zimmermann, Judith; von Davier, Alina A.; Buhmann, Joachim M.; Heinimann, Hans R.

2018-01-01

Graduate admission has become a critical process in tertiary education, whereby selecting valid admissions instruments is key. This study assessed the validity of Graduate Record Examination (GRE) General Test scores for admission to Master's programmes at a technical university in Europe. We investigated the indicative value of GRE scores for the Master's programme grade point average (GGPA) with and without the addition of the undergraduate GPA (UGPA) and the TOEFL score, and of GRE scores for study completion and Master's thesis performance. GRE scores explained 20% of the variation in the GGPA, while additional 7% were explained by the TOEFL score and 3% by the UGPA. Contrary to common belief, the GRE quantitative reasoning score showed only little explanatory power. GRE scores were also weakly related to study progress but not to thesis performance. Nevertheless, GRE and TOEFL scores were found to be sensible admissions instruments. Rigorous methodology was used to obtain highly reliable results.

Modeling Reality - How Computers Mirror Life

NASA Astrophysics Data System (ADS)

Bialynicki-Birula, Iwo; Bialynicka-Birula, Iwona

2005-01-01

The bookModeling Reality covers a wide range of fascinating subjects, accessible to anyone who wants to learn about the use of computer modeling to solve a diverse range of problems, but who does not possess a specialized training in mathematics or computer science. The material presented is pitched at the level of high-school graduates, even though it covers some advanced topics (cellular automata, Shannon's measure of information, deterministic chaos, fractals, game theory, neural networks, genetic algorithms, and Turing machines). These advanced topics are explained in terms of well known simple concepts: Cellular automata - Game of Life, Shannon's formula - Game of twenty questions, Game theory - Television quiz, etc. The book is unique in explaining in a straightforward, yet complete, fashion many important ideas, related to various models of reality and their applications. Twenty-five programs, written especially for this book, are provided on an accompanying CD. They greatly enhance its pedagogical value and make learning of even the more complex topics an enjoyable pleasure.

Switching phenomenon in a Se{70}Te{30-x}Cd{x} films

NASA Astrophysics Data System (ADS)

Afifi, M. A.; Bekheet, A. E.; Hegab, N. A.; Wahab, L. A.; Shehata, H. A.

2007-11-01

Amorphous Se{70}Te{30-x}Cd{x} (x = 0, 10) are obtained by thermal evaporation under vacuum of bulk materials on pyrographite and glass substrates. The I-V characteristic curves for the two film compositions are typical for a memory switch. They exhibited a transition from an ohmic region in the lower field followed by non-ohmic region in the high field region in the preswitching region, which has been explained by the Poole-Frenkel effect. The temperature dependence of current in the ohmic region is found to be of thermally activated process. The mean value of the threshold voltage bar{V}th increases linearly with increasing film thickness in the thickness range (100 491 nm), while it decreases exponentially with increasing temperature in the temperature range (293 343 K) for both compositions. The results are explained in accordance with the electrothermal model for the switching process. The effect of Cd on these parameters is also investigated.

On the Origin of Pulsations of Sub-THz Emission from Solar Flares

NASA Astrophysics Data System (ADS)

Zaitsev, V. V.; Stepanov, A. V.; Kaufmann, P.

2014-08-01

We propose a model to explain fast pulsations in sub-THz emission from solar flares. The model is based on the approach of a flaring loop as an equivalent electric circuit and explains the pulse-repetition rate, the high-quality factor, Q≥103, low modulation depth, pulse synchronism at different frequencies, and the dependence of the pulse-repetition rate on the emission flux, observed by Kaufmann et al. ( Astrophys. J. 697, 420, 2009). We solved the nonlinear equation for electric current oscillations using a Van der Pol method and found the steady-state value for the amplitude of the current oscillations. Using the pulse rate variation during the flare on 4 November 2003, we found a decrease of the electric current from 1.7×1012 A in the flare maximum to 4×1010 A just after the burst. Our model is consistent with the plasma mechanism of sub-THz emission suggested recently by Zaitsev, Stepanov, and Melnikov ( Astron. Lett. 39, 650, 2013).

Eddy Mediated Nutrient Pattern in the North Eastern Arabian Sea

NASA Astrophysics Data System (ADS)

Thachaparambil, M.; Moolakkal Antony, R.; B R, S.; V N, S.; N, C.; M, S.

2016-02-01

A Cold Core Eddy (CCE) mediated nutrient pattern in the North Eastern Arabian Sea (NEAS) is explained based on in situ measurments during March 2013 onboard FORV Sagar Sampada which was not reported earlier in the area. Samples for physical, chemical and biological parameters were collected in 5 stations along the diameter of the eddy and following standard protocols. The core of the CCE is identified at 21°20.38'N; 66°30.68'E with a diameter of 120Km. Earlier studies explaining the process and the forcing mechanism of the particular eddy records that, the eddy is short term (1-3 months) and is regular during the season. Surface waters were well oxygenated (>4.8 ml L-1) in the core. Surface value of nutrients viz., Nitrate, Nitrite, Silicate and phosphate in the core regions was 0.9µM, 0.01 µM, 0.5 µM and 0.7 µM respectively indicating upwelling in the core. Spring intermonsoon (SIM) is generally termed as a transition period between the active winter and summer seasons and as per earlier studies, high biological production and the regularly occurring Noctilica bloom is supported by the nutrient loading due to convective mixing during winter as well as regenerated production. However, present observations shows that, nutrient pumping due to the upwelling associated with the CCE also contributes for sustaining high biological production and are evident in the Chl a and mesozooplankton biovolume which records values of 4.35mg/m3 and 1.09ml/m3 respectively in the core. An intense Noctiluca blooms observed in the western flank of the eddy (Chl a 13.25 mg/m3; cell density 5.8×106 cells/litre), where Nitrate concentration records 1.04µM explains the role of such mesoscale processes in the sustenance of the HAB events. While eastern flank of the CCE showed typical open ocean condition of the season showing Nitrate 0.08µM; Chl a 0.23mg/m3; and phytoplankton cell density as 421 cells/litre. Keywords: Cold core eddy, nutrients, NEAS, SIM, biological production

Temperature dependent self-compensation in Al- and Ga-doped Mg0.05 Zn0.95 O thin films grown by pulsed laser deposition

NASA Astrophysics Data System (ADS)

Mavlonov, Abdurashid; Richter, Steffen; von Wenckstern, Holger; Schmidt-Grund, Rüdiger; Lorenz, Michael; Grundmann, Marius

2016-11-01

We studied the doping efficiency of Al and Ga dopants in (Mg,Zn)O alloys as a function of the growth temperature and post growth annealing times. High-temperature growth results in the highest structural quality and highest electron mobility; the doping efficiency is limited by the dopant's solubility. It was investigated in detail that a low growth temperature is needed to achieve free carrier densities above the solubility limit of the dopants. Samples grown at temperatures of 300 °C and below have a free carrier density significantly above the solubility limit yielding the minimum resistivity of ρmin=4.8 ×10-4 Ω cm for Mg0.05 Zn0.95 O:Al thin films grown on glass at 300 °C . Annealing of these samples reduces the free carrier density and the absorption edge to values similar to those of samples grown at high temperatures. The saturation of the free carrier density and the optical bandgap at their high temperature growth/annealing values is explained by the thermal creation of acceptor-like compensating defects in thermodynamic equilibrium.

Relative Deprivation and the Gender Wage Gap.

ERIC Educational Resources Information Center

Jackson, Linda A.

1989-01-01

Discusses how gender differences in the value of pay, based on relative deprivation theory, explain women's paradoxical contentment with lower wages. Presents a model of pay satisfaction to integrate value-based and comparative-referent explanations of the relationship between gender and pay satisfaction. Discusses economic approaches to the…

Implications for the Daily Variation and the Low Value of Thermal Inertia at Arabia Terra on Mars

NASA Astrophysics Data System (ADS)

Toyota, T.; Saruya, T.; Kurita, K.

2010-12-01

Active nature of the Martian surface is considered to be responsible for various styles of the atmosphere-surface interaction. Here, we propose an idea to interpret the daily variation and the low value of thermal inertia at Arabia Terra on Mars. Thermal inertia calculated with the surface temperature obtained by remote sensing exhibits daily variation and seasonal variation. Putzig and Mellon [1] suggested that horizontal or vertical heterogeneity may yield apparent thermal inertia which varies with time of day and season. However, their interpretation couldn’t completely explain the extent and the phase of the temporal variation of thermal inertia at Arabia Terra. We would like to propose another possibility to explain the characteristics of the thermal inertia at Arabia Terra. In addition, the value of thermal inertia is extremely low at Arabia Terra. Daytime thermal inertia at Arabia Terra is as low as 20 tiu [1,2], which is lower than the value of thermal inertia of 1 micron dust aggregates ( 61 tiu [3]). To explain these characteristics of Arabia Terra, we proposed an idea that condensation and sublimation of water ice at the granular surface cause the daily variation and the low value of the thermal inertia at Arabia Terra. At nighttime, water vapor condenses at the surface. Immediately after sunrise, water ice at the surface sublimates. Electric force and sublimating gas pressure could affect the porosity of the surface. We suppose that the daily variation of the thermal inertia is caused by presence of deposition/removal of water ice and the low value of the thermal inertia is caused by the higher value of the bulk porosity than random close packing. To substantiate the above model, there remain four main questions to be answered. 1) Is there sufficient water vapor at the atmosphere above Arabia Terra?, 2) Does the sufficient amount of water condense at the surface during the night?, 3) Can water vapor and other factors make the surface porosity higher? and 4) How much does the higher value of the porosity make the bulk thermal inertia lower? We investigated previous studies for question 1) and performed a numerical simulation for the sublimation/condensation of water ice for question 2). We also performed laboratory experiments to investigate question 3) and 4). We obtained results which showed 1) There are sufficient water vapor at the atmosphere above Arabia Terra, 2) It is difficult for the sufficient amount of water vapor to condense at the surface during the night in our numerical model with limited parameters, 3) Condensation/sublimation of water ice and other mechanical effects could affect the bulk porosity at the surface, and 4) The high value of the porosity make the bulk thermal inertia lower by factor of two. References [1] N. E. Putzig and M. T. Mellon, Icarus 191, 68 (2007). [2] T. Saruya, T. Toyota, D. Baratoux, and K. Kurita, 41th LPSC, 1306 (2010) [3] M. T. Mellon, R. L. Fergason, and N. E. Putzig, The Martian Surface, Cambridge University Press. (2008). [4] M. A. Presley1 and R. A. Craddock, Jour. Geophys. Res. 111, E09013 (2006).

Explaining the forgetting bias effect on value judgments: The influence of memory for a past test.

PubMed

Rhodes, Matthew G; Witherby, Amber E; Castel, Alan D; Murayama, Kou

2017-04-01

People often feel that information that was forgotten is less important than remembered information. Prior work has shown that participants assign higher importance to remembered information while undervaluing forgotten information. The current study examined two possible accounts of this finding. In three experiments, participants studied lists of words in which each word was randomly assigned a point value denoting the value of remembering the word. Following the presentation of each list participants engaged in a free recall test. After the presentation of all lists participants were shown each of the words they had studied and asked to recall the point value that was initially paired with each word. Experiment 1 tested a fluency-based account by presenting items for value judgments in a low-fluency or high-fluency format. Experiment 2 examined whether value judgments reflect attributions based on the familiarity of an item when value judgments are made. Finally, in Experiment 3, we evaluated whether participants believe that forgotten words are less important by having them judge whether an item was initially recalled or forgotten prior to making a value judgment. Manipulating the fluency of an item presented for judgment had no influence on value ratings (Experiment 1) and familiarity exerted a limited influence on value judgments (Experiment 2). More importantly, participants' value judgments appeared to reflect a theory that remembered information is more valuable than forgotten information (Experiment 3). Overall, the present work suggests that individuals may apply a theory about remembering and forgetting to retrospectively assess the value of information.

Work-related fatigue: the specific case of highly educated women in the Netherlands.

PubMed

Verdonk, Petra; Hooftman, Wendela E; van Veldhoven, Marc J P M; Boelens, Louise R M; Koppes, Lando L J

2010-03-01

This study aims to establish the prevalence of high work-related fatigue (need for recovery, NFR) among employees and to explain group differences categorized by gender, age, and education. The study particularly aims to clarify prevalence and explanatory factors in highly educated women. In 2005 and 2006, large representative samples of 80,000 Dutch employees (net response rate 33.0%; N = 47,263) received the Netherlands working conditions survey questionnaire. First, we calculated the prevalence of high NFR for men and women with different age and education levels. The average prevalence of high NFR was 28.8% and was highest among highly educated women (35.2%) in particular those aged 50-64 years (40.3%). Second, logistic regression analyses were used to compare subgroups' NFR in relation to situational factors, working conditions, and health. Three comparisons were made: (1) highly educated women versus men; (2) highly educated versus lower educated women and; (3) older highly educated versus younger highly educated women. The situational, working conditions and health factors in our model did not explain the gender differences among highly educated employees (OR = 1.37; CI = 1.3-1.5, adjusted for all factors OR = 1.32; CI = 1.2-1.5). Despite that lower autonomy and workplace violence explained highly educated women's NFR, working fewer hours counterbalanced this. Time pressure in work largely explained the differences in NFR among women at different education levels (crude OR 1.44; CI = 1.4-1.5, adjusted OR 1.14; CI = 1.0-1.3). In the age comparison, lower health ratings, more adverse working conditions, and working as a teacher explained older highly educated women's high prevalence of high NFR (crude OR 1.32; CI = 1.2-1.5, adjusted OR 0.94; CI = 0.8-1.2). NFR has high prevalence in highly educated women (35.2%) in particular those aged 50-64 years (40.3%). Our model did not explain gender differences in NFR, because working fewer hours counterbalanced the effects of lower autonomy and external workplace violence. Our model, in particular time pressure, largely explained differences in NFR between women at different education levels. Age differences in the prevalence of high NFR among highly educated women's were fully explained by our model. Main factors were lower health ratings, adverse working conditions, and working as a teacher.

Petrogenesis of low-δ18O quartz porphyry dykes, Koegel Fontein complex, South Africa

NASA Astrophysics Data System (ADS)

Harris, Chris; Mulder, Kwenidyn; Sarkar, Saheli; Whitehead, Benjamin; Roopnarain, Sherissa

2018-04-01

This paper investigates the origin of low-δ18O quartz porphyry dykes associated with the 144-133 Ma Koegel Fontein Igneous Complex, which was intruded during the initial phase of breakup of Africa and South America. The 25-km diameter Rietpoort Granite is the largest and youngest phase of activity, and is roofed by a 10-km diameter pendant of gneiss. Quartz porphyry (QP) dykes, up to 15 m in width, strike NW-SE across the complex. The QP dykes that intruded outside the granite have similar quartz phenocryst δ18O values (average 8.0‰, ± 0.7, n = 33) to the granite (average 8.3 ± 1.0, n = 7). The QP dykes that intruded the roof pendant have quartz phenocrysts with more variable δ18O values (average 1.6‰, ± 2.1, n = 55). In some cases quartz phenocrysts have δ18O values as low as - 2.5‰. The variation in δ18O value within the quartz crystal population of individual dykes is small relative to the overall range, and core and rim material from individual quartz phenocrysts in three samples are identical within error. There is no evidence that quartz phenocryst δ18O values have been affected by fluid-rock interaction. Based on a Δquartz-magma value of 0.6‰, magma δ18O values must have been as low as - 3.1‰. Samples collected along the length of the two main QP dykes that traverse the roof pendant have quartz phenocryst δ18O values that range from + 1.1 to + 4.6‰, and - 2.3 to + 5.6‰, respectively. These δ18O values correlate negatively ( r = - 0.96) with initial 87Sr/86Sr, which can be explained by the event that lowered δ18O values of the source being older than the dykes. We suggest that the QP dykes were fed by magma produced by partial melting of gneiss, which had been variably altered at high temperature by 18O-depleted meteoric water during global glaciation at 550 Ma. The early melts had variable δ18O value but as melt pockets interconnected during melting, the δ18O values approached that of average gneiss. Variable quartz phenocryst δ18O values in the same dyke can be explained by vertical emplacement, at variable rates of ascent along the dyke. The lateral variation in quartz, and hence magma δ18O value at a particular point along a single dyke would depend on the rate of ascent of magma at that point along the dyke, and the `age' of the particular magma batch.

Vulnerability and risk management of Agave species in the Tehuacán Valley, México.

PubMed

Delgado-Lemus, América; Torres, Ignacio; Blancas, José; Casas, Alejandro

2014-07-03

Our study analysed the vulnerability of the useful Agave species of the Tehuacán Valley, Mexico, considering ecological, cultural and economic aspects, and management types. We hypothesized that management intensity is proportional to the degree of risk of a species in order to decrease its vulnerability. Distribution of Agave species was monitored in 36 types of plant associations. Ethnobotanical studies were conducted in 13 villages and six markets. The vulnerability of each species was calculated by assigning risk values to the variables analysed. The vulnerability and management intensity indexes were estimated through the scores of the first principal component of PCA. Variation of management data explained by ecological, cultural and economic information were analysed through canonical correspondence analyses (CCA). A linear regression analysis identified the relation between vulnerability and management intensity. We recorded presence of agave species in 20 of 36 vegetation types. Out of 34 Agave species, 28 were recorded to have one to 16 use types; 16 species are used as food, 13 for live fences, 13 for producing 'pulque', 11 for fibre and ornamental, 9 for construction. Seven species are used for preparing mescal, activity representing the highest risk. Seven Agave species are exclusively extracted from the wild and the others receive some management type. Incipient cultivation was identified in A. potatorum whose seedlings are grown in nurseries. Intensive cultivation through vegetative propagation occurs with domesticated species of wide distribution in Mexico. The highest management intensity values were recorded in widely distributed, cultivated and domesticated species, but the regionally native species more intensively managed were those with higher demand and economic value, protected by collective regulations because of their scarcity. The regression analysis indicated significant relation (R2=0.677, P<0.001) between vulnerability and management indexes. CCA explained 61.0% of variation of management intensity, mainly by socio-cultural factors (30.32%), whereas ecological data explained 7.6% and the intersection of all factors 21.36%. The highest vulnerability was identified in wild species restrictedly distributed and/or highly extracted. Social pressures may increase the natural vulnerability of some species and these species are particularly those native species receiving some management form.

Comparative Genomics and Association Mapping Approaches for Blast Resistant Genes in Finger Millet Using SSRs

PubMed Central

Babu, B. Kalyana; Dinesh, Pandey; Agrawal, Pawan K.; Sood, S.; Chandrashekara, C.; Bhatt, Jagadish C.; Kumar, Anil

2014-01-01

The major limiting factor for production and productivity of finger millet crop is blast disease caused by Magnaporthe grisea. Since, the genome sequence information available in finger millet crop is scarce, comparative genomics plays a very important role in identification of genes/QTLs linked to the blast resistance genes using SSR markers. In the present study, a total of 58 genic SSRs were developed for use in genetic analysis of a global collection of 190 finger millet genotypes. The 58 SSRs yielded ninety five scorable alleles and the polymorphism information content varied from 0.186 to 0.677 at an average of 0.385. The gene diversity was in the range of 0.208 to 0.726 with an average of 0.487. Association mapping for blast resistance was done using 104 SSR markers which identified four QTLs for finger blast and one QTL for neck blast resistance. The genomic marker RM262 and genic marker FMBLEST32 were linked to finger blast disease at a P value of 0.007 and explained phenotypic variance (R2) of 10% and 8% respectively. The genomic marker UGEP81 was associated to finger blast at a P value of 0.009 and explained 7.5% of R2. The QTLs for neck blast was associated with the genomic SSR marker UGEP18 at a P value of 0.01, which explained 11% of R2. Three QTLs for blast resistance were found common by using both GLM and MLM approaches. The resistant alleles were found to be present mostly in the exotic genotypes. Among the genotypes of NW Himalayan region of India, VHC3997, VHC3996 and VHC3930 were found highly resistant, which may be effectively used as parents for developing blast resistant cultivars in the NW Himalayan region of India. The markers linked to the QTLs for blast resistance in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of blast resistant alleles into locally adapted cultivars. PMID:24915067

Comparative genomics and association mapping approaches for blast resistant genes in finger millet using SSRs.

PubMed

Babu, B Kalyana; Dinesh, Pandey; Agrawal, Pawan K; Sood, S; Chandrashekara, C; Bhatt, Jagadish C; Kumar, Anil

2014-01-01

The major limiting factor for production and productivity of finger millet crop is blast disease caused by Magnaporthe grisea. Since, the genome sequence information available in finger millet crop is scarce, comparative genomics plays a very important role in identification of genes/QTLs linked to the blast resistance genes using SSR markers. In the present study, a total of 58 genic SSRs were developed for use in genetic analysis of a global collection of 190 finger millet genotypes. The 58 SSRs yielded ninety five scorable alleles and the polymorphism information content varied from 0.186 to 0.677 at an average of 0.385. The gene diversity was in the range of 0.208 to 0.726 with an average of 0.487. Association mapping for blast resistance was done using 104 SSR markers which identified four QTLs for finger blast and one QTL for neck blast resistance. The genomic marker RM262 and genic marker FMBLEST32 were linked to finger blast disease at a P value of 0.007 and explained phenotypic variance (R²) of 10% and 8% respectively. The genomic marker UGEP81 was associated to finger blast at a P value of 0.009 and explained 7.5% of R². The QTLs for neck blast was associated with the genomic SSR marker UGEP18 at a P value of 0.01, which explained 11% of R². Three QTLs for blast resistance were found common by using both GLM and MLM approaches. The resistant alleles were found to be present mostly in the exotic genotypes. Among the genotypes of NW Himalayan region of India, VHC3997, VHC3996 and VHC3930 were found highly resistant, which may be effectively used as parents for developing blast resistant cultivars in the NW Himalayan region of India. The markers linked to the QTLs for blast resistance in the present study can be further used for cloning of the full length gene, fine mapping and their further use in the marker assisted breeding programmes for introgression of blast resistant alleles into locally adapted cultivars.

Psychometric Testing of the Greek Version of the Clinical Learning Environment-Teacher (CLES+T).

PubMed

Papastavrou, Evridiki; Dimitriadou, Maria; Tsangari, Haritini

2015-09-01

Clinical practice is an important part of nursing education, and robust instruments are required to evaluate the effectiveness of the hospital setting as a learning environment. The study aim is the psychometric test of the Clinical Learning Environment+Teacher (CLES+T) scale-Greek version. 463 students practicing in acute care hospitals participated in the study. The reliability of the instrument was estimated with Cronbach's alpha coefficients. The construct validity was evaluated using exploratory factor analysis (EFA) with Varimax rotation. Convergent validity was examined by measuring the bivariate correlations between the scale/subscales. Content, validity and semantic equivalence were examined through reviews by a panel of experts. The total scale showed high internal consistency (α=0.95). EFA was identical to the original scale, had eigen values larger than one and explained a total of 67.4% of the variance. The factor with the highest eigen value and the largest percentage of variance explained was "supervisory relationship", with an original eigenvalue of 13.1 (6.8 after Varimax rotation) and an explanation of around 38% of the variance (or 20% after rotation). Convergent validity was examined by measuring the bivariate correlations between the scale and a question that measured the general satisfaction. The Greek version of the CLES+T is a valid and reliable instrument that can be used to examine students' perceptions of the clinical learning environment.

Metal contamination of agricultural soils in the copper mining areas of Singhbhum shear zone in India

NASA Astrophysics Data System (ADS)

Giri, Soma; Singh, Abhay Kumar; Mahato, Mukesh Kumar

2017-06-01

The study was intended to investigate the heavy metal contamination in the agricultural soils of the copper mining areas in Singhbhum shear zone, India. The total concentrations of the metals were determined by inductively coupled plasma-mass spectrometer (ICPMS). Pollution levels were assessed by calculating enrichment factor (EF), geo-accumulation index (I_geo), contamination factors (CF), pollution load index ( PLI), Nemerow index and ecological risk index (RI). The metal concentrations in the soil samples exceeded the average shale values for almost all the metals. Principal component analysis resulted in extraction of three factors explaining 82.6% of the data variability and indicated anthropogenic contribution of Cu, Ni, Co, Cr, Mn and Pb. The EF and I_geo values indicated very high contamination with respect to Cu followed by As and Zn in the agricultural soils. The values of PLI, RI and Nemerow index, which considered the overall effect of all the studied metals on the soils, revealed that 50% of the locations were highly polluted with respect to metals. The pollution levels varied with the proximity to the copper mining and processing units. Consequently, the results advocate the necessity of periodic monitoring of the agricultural soils of the area and development of proper management strategies to reduce the metal pollution.

Reliability of an interactive computer program for advance care planning.

PubMed

Schubart, Jane R; Levi, Benjamin H; Camacho, Fabian; Whitehead, Megan; Farace, Elana; Green, Michael J

2012-06-01

Despite widespread efforts to promote advance directives (ADs), completion rates remain low. Making Your Wishes Known: Planning Your Medical Future (MYWK) is an interactive computer program that guides individuals through the process of advance care planning, explaining health conditions and interventions that commonly involve life or death decisions, helps them articulate their values/goals, and translates users' preferences into a detailed AD document. The purpose of this study was to demonstrate that (in the absence of major life changes) the AD generated by MYWK reliably reflects an individual's values/preferences. English speakers ≥30 years old completed MYWK twice, 4 to 6 weeks apart. Reliability indices were assessed for three AD components: General Wishes; Specific Wishes for treatment; and Quality-of-Life values (QoL). Twenty-four participants completed the study. Both the Specific Wishes and QoL scales had high internal consistency in both time periods (Knuder Richardson formula 20 [KR-20]=0.83-0.95, and 0.86-0.89). Test-retest reliability was perfect for General Wishes (κ=1), high for QoL (Pearson's correlation coefficient=0.83), but lower for Specific Wishes (Pearson's correlation coefficient=0.57). MYWK generates an AD where General Wishes and QoL (but not Specific Wishes) statements remain consistent over time.

Reliability of an Interactive Computer Program for Advance Care Planning

PubMed Central

Levi, Benjamin H.; Camacho, Fabian; Whitehead, Megan; Farace, Elana; Green, Michael J

2012-01-01

Abstract Despite widespread efforts to promote advance directives (ADs), completion rates remain low. Making Your Wishes Known: Planning Your Medical Future (MYWK) is an interactive computer program that guides individuals through the process of advance care planning, explaining health conditions and interventions that commonly involve life or death decisions, helps them articulate their values/goals, and translates users' preferences into a detailed AD document. The purpose of this study was to demonstrate that (in the absence of major life changes) the AD generated by MYWK reliably reflects an individual's values/preferences. English speakers ≥30 years old completed MYWK twice, 4 to 6 weeks apart. Reliability indices were assessed for three AD components: General Wishes; Specific Wishes for treatment; and Quality-of-Life values (QoL). Twenty-four participants completed the study. Both the Specific Wishes and QoL scales had high internal consistency in both time periods (Knuder Richardson formula 20 [KR-20]=0.83–0.95, and 0.86–0.89). Test-retest reliability was perfect for General Wishes (κ=1), high for QoL (Pearson's correlation coefficient=0.83), but lower for Specific Wishes (Pearson's correlation coefficient=0.57). MYWK generates an AD where General Wishes and QoL (but not Specific Wishes) statements remain consistent over time. PMID:22512830

The multiple facets of Peto's paradox: a life-history model for the evolution of cancer suppression

PubMed Central

Brown, Joel S.; Cunningham, Jessica J.; Gatenby, Robert A.

2015-01-01

Large animals should have higher lifetime probabilities of cancer than small animals because each cell division carries an attendant risk of mutating towards a tumour lineage. However, this is not observed—a (Peto's) paradox that suggests large and/or long-lived species have evolved effective cancer suppression mechanisms. Using the Euler–Lotka population model, we demonstrate the evolutionary value of cancer suppression as determined by the ‘cost’ (decreased fecundity) of suppression verses the ‘cost’ of cancer (reduced survivorship). Body size per se will not select for sufficient cancer suppression to explain the paradox. Rather, cancer suppression should be most extreme when the probability of non-cancer death decreases with age (e.g. alligators), maturation is delayed, fecundity rates are low and fecundity increases with age. Thus, the value of cancer suppression is predicted to be lowest in the vole (short lifespan, high fecundity) and highest in the naked mole rat (long lived with late female sexual maturity). The life history of pre-industrial humans likely selected for quite low levels of cancer suppression. In modern humans that live much longer, this level results in unusually high lifetime cancer risks. The model predicts a lifetime risk of 49% compared with the current empirical value of 43%. PMID:26056365

Molecular features determining different partitioning patterns of papain and bromelain in aqueous two-phase systems.

PubMed

Rocha, Maria Victoria; Nerli, Bibiana Beatriz

2013-10-01

The partitioning patterns of papain (PAP) and bromelain (BR), two well-known cysteine-proteases, in polyethyleneglycol/sodium citrate aqueous two-phase systems (ATPSs) were determined. Polyethyleneglycols of different molecular weight (600, 1000, 2000, 4600 and 8000) were assayed. Thermodynamic characterization of partitioning process, spectroscopy measurements and computational calculations of protein surface properties were also carried out in order to explain their differential partitioning behavior. PAP was observed to be displaced to the salt-enriched phase in all the assayed systems with partition coefficients (KpPAP) values between 0.2 and 0.9, while BR exhibited a high affinity for the polymer phase in systems formed by PEGs of low molecular weight (600 and 1000) with partition coefficients (KpBR) values close to 3. KpBR values resulted higher than KpPAP in all the cases. This difference could be assigned neither to the charge nor to the size of the partitioned biomolecules since PAP and BR possess similar molecular weight (23,000) and isoelectric point (9.60). The presence of highly exposed tryptophans and positively charged residues (Lys, Arg and His) in BR molecule would be responsible for a charge transfer interaction between PEG and the protein and, therefore, the uneven distribution of BR in these systems. Copyright © 2013 Elsevier B.V. All rights reserved.

Hierarchical competitions subserving multi-attribute choice

PubMed Central

Hunt, Laurence T; Dolan, Raymond J; Behrens, Timothy EJ

2015-01-01

Valuation is a key tenet of decision neuroscience, where it is generally assumed that different attributes of competing options are assimilated into unitary values. Such values are central to current neural models of choice. By contrast, psychological studies emphasize complex interactions between choice and valuation. Principles of neuronal selection also suggest competitive inhibition may occur in early valuation stages, before option selection. Here, we show behavior in multi-attribute choice is best explained by a model involving competition at multiple levels of representation. This hierarchical model also explains neural signals in human brain regions previously linked to valuation, including striatum, parietal and prefrontal cortex, where activity represents competition within-attribute, competition between attributes, and option selection. This multi-layered inhibition framework challenges the assumption that option values are computed before choice. Instead our results indicate a canonical competition mechanism throughout all stages of a processing hierarchy, not simply at a final choice stage. PMID:25306549

Effect of sample volume on metastable zone width and induction time

NASA Astrophysics Data System (ADS)

Kubota, Noriaki

2012-04-01

The metastable zone width (MSZW) and the induction time, measured for a large sample (say>0.1 L) are reproducible and deterministic, while, for a small sample (say<1 mL), these values are irreproducible and stochastic. Such behaviors of MSZW and induction time were theoretically discussed both with stochastic and deterministic models. Equations for the distribution of stochastic MSZW and induction time were derived. The average values of stochastic MSZW and induction time both decreased with an increase in sample volume, while, the deterministic MSZW and induction time remained unchanged. Such different behaviors with variation in sample volume were explained in terms of detection sensitivity of crystallization events. The average values of MSZW and induction time in the stochastic model were compared with the deterministic MSZW and induction time, respectively. Literature data reported for paracetamol aqueous solution were explained theoretically with the presented models.

The Landscape of the Liberal Arts

ERIC Educational Resources Information Center

Roche, Mark W.

2013-01-01

This chapter provides a rationale for the value of a liberal arts education, addressing briefly the recent history of the liberal arts, explaining the value of the liberal arts in diverse educational settings as opposed to simply residential liberal arts colleges, and exploring a contemporary rationale for the liberal arts.

When Benefits Are Difficult to Measure.

ERIC Educational Resources Information Center

Birdsall, William C.

1987-01-01

It is difficult to apply benefit cost analysis to human service programs. This paper explains "threshold benefit analysis," the derivation of the minimum dollar value which the benefits must attain in order for their value to equal the intervention costs. The method is applied to a mobility training program. (BS)

A Value-Added Framework for Analyzing Electronic and Print Publishing.

ERIC Educational Resources Information Center

Perritt, Henry H., Jr.

1991-01-01

Discusses changes in the publishing industry resulting from digital electronic networks and optical storage technologies, and explains attributes of information products as types of value for both print and electronic contexts. Electronic products necessary for a shift from paper to electronic formats are identified, and legal issues are…

Interpersonal Communication Behaviors and Self-Actualizing Values: A Conceptual Framework.

ERIC Educational Resources Information Center

Macklin, Thomas

This report addresses the relationship between self-actualizing values and interpersonal communication behaviors. After a discussion of behavioristic and humanistic frameworks for social science research, the paper explains Abraham Maslow's and Carl Roger's concepts of self-actualization as the tendency toward completing and perfecting one's…

Job Preferences in the Anticipatory Socialization Phase: A Comparison of Two Matching Models.

ERIC Educational Resources Information Center

Moss, Mira K.; Frieze, Irene Hanson

1993-01-01

Responses from 86 business administration graduate students tested (1) a model matching self-concept to development of job preferences and (2) an expectancy-value model. Both models significantly predicted job preferences; a higher proportion of variance was explained by the expectancy-value model. (SK)

Charting the Eccles' Expectancy-Value Model from Mothers' Beliefs in Childhood to Youths' Activities in Adolescence

ERIC Educational Resources Information Center

Simpkins, Sandra D.; Fredricks, Jennifer A.; Eccles, Jacquelynne S.

2012-01-01

The Eccles' expectancy-value model posits that a cascade of mechanisms explain associations between parents' beliefs and youths' achievement-related behaviors. Specifically, parents' beliefs predict parents' behaviors; in turn, parents' behaviors predict youths' motivational beliefs, and youths' motivational beliefs predict their behaviors. This…

Exploring Adolescent Motivations for Pursuing Maths-Related Careers

ERIC Educational Resources Information Center

Watt, Helen M. G.

2005-01-01

Adolescents from grade 9 in Sydney Australia (N = 60) were interviewed regarding why they would or would not consider pursuing maths-related careers. Open-ended interview data explored the comprehensiveness of explanations within the Expectancy-Value framework. The Expectancy-Value model is the major motivational framework for explaining students'…

Paradigm Privilege: Determining the Value of Research in Teacher Education Policy Making.

ERIC Educational Resources Information Center

Bales, Barbara L.

This paper explains that despite the long debate over the relative value of quantitative and qualitative educational research and attempts to talk across disciplines, quantitative research dominates educational policy circles. As a result, quality qualitative research may not enter into educational policy conversations. The paper discusses whether…

Introduction

NASA Astrophysics Data System (ADS)

Flomenbom, Ophir; Castañeda-Priego, Ramón; Peeters, François

2014-11-01

In this document, we present the Special Issue's projects; these include reviews and articles about mathematical solutions and formulations of single-file dynamics (SFD), yet also its computational modeling, experimental evidence, and value in explaining real life occurrences. In particular, we introduce projects focusing on electron dynamics on liquid helium in channels with changing width, on the zig-zag configuration in files with longitudinal movement, on expanding files, on both heterogeneous and slow files, on files with external forces, and on the importance of the interaction potential shape on the particle dynamics along the file. Applications of SFD are of intrinsic value in life sciences, biophysics, physics, and materials science, since they can explain a large diversity of many-body systems, e.g., biological channels, biological motors, membranes, crowding, electron motion in proteins, etc. These systems are explained in all the projects that participate in this topical issue. This Special Issue can therefore intrigue, inspire and advance scientifically young people, yet also those scientists that actively work in this field.

The variance of the locally measured Hubble parameter explained with different estimators

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

Odderskov, Io; Hannestad, Steen; Brandbyge, Jacob, E-mail: isho07@phys.au.dk, E-mail: sth@phys.au.dk, E-mail: jacobb@phys.au.dk

We study the expected variance of measurements of the Hubble constant, H {sub 0}, as calculated in either linear perturbation theory or using non-linear velocity power spectra derived from N -body simulations. We compare the variance with that obtained by carrying out mock observations in the N-body simulations, and show that the estimator typically used for the local Hubble constant in studies based on perturbation theory is different from the one used in studies based on N-body simulations. The latter gives larger weight to distant sources, which explains why studies based on N-body simulations tend to obtain a smaller variancemore » than that found from studies based on the power spectrum. Although both approaches result in a variance too small to explain the discrepancy between the value of H {sub 0} from CMB measurements and the value measured in the local universe, these considerations are important in light of the percent determination of the Hubble constant in the local universe.« less

Yogurt Is a Low-Glycemic Index Food.

PubMed

Wolever, Thomas Ms

2017-07-01

High yogurt intake is associated with a reduced risk of type 2 diabetes (T2DM). Although several mechanisms could explain this association, this paper addresses the glycemic and insulinemic impact of yogurt. There is evidence that low-glycemic index (GI) and low-glycemic load (GL) diets are associated with a reduced risk of T2DM. The 93 GI values for yogurt in the University of Sydney's GI database have a mean ± SD of 34 ± 13, and 92% of the yogurts are low-GI (≤55). The 43 plain yogurts in the database have a lower GI than the 50 sweetened yogurts, 27 ± 11 compared with 41 ± 11 ( P < 0.0001). This difference is not explained by sugar, per se, but rather by the higher protein-to-carbohydrate ratio in plain yogurt. Although yogurt has a low GI, its insulinemic index (II) is higher than its GI. High insulin responses may be deleterious because hyperinsulinemia is associated with an increased risk of T2DM. Nevertheless, this may not be a concern for yogurt because, although its II is higher than its GI, the II of yogurt is within the range of II values for nondairy low-GI foods. In addition, mixed meals containing dairy protein elicit insulin responses similar to those elicited by mixed meals of similar composition containing nondairy protein. Because the GI of yogurt is lower than that of most other carbohydrate foods, exchanging yogurt for other protein and carbohydrate sources can reduce the GI and GL of the diet, and is in line with recommended dietary patterns, which include whole grains, fruits, vegetables, nuts, legumes, fish, vegetable oils, and yogurt. © 2017 American Society for Nutrition.

Fish mucus versus parasitic gnathiid isopods as sources of energy and sunscreens for a cleaner fish

NASA Astrophysics Data System (ADS)

Eckes, Maxi; Dove, Sophie; Siebeck, Ulrike E.; Grutter, Alexandra S.

2015-09-01

The cleaning behaviour of the bluestreak cleaner wrasse Labroides dimidiatus is extensively used as a model system for understanding cooperation. It feeds mainly on blood-sucking gnathiid isopods and also on the epidermal mucus of client fish; the nutritional quality of these foods, however, is unknown. The epidermal mucus of reef fish contains ultraviolet (UV)-absorbing compounds (mycosporine-like amino acids, MAAs), which are only obtained via the diet; nevertheless, while La. dimidiatus has high amounts of MAAs in its mucus, their source is unknown. Therefore, the energetic value (calories and protein estimated using carbon and nitrogen) and MAA level in gnathiids and mucus from several clients [parrotfishes, wrasses (Labridae), and a snapper (Lutjanidae)] were determined. The energetic value of mucus and gnathiids varied among fishes. Overall, carbon, nitrogen, calories, and protein per dry weight were higher in the mucus of most client species compared to gnathiids. Thus, depending on the client species, mucus may be energetically more advantageous for cleaner wrasse to feed on than gnathiids. UV absorbance, a confirmed proxy for MAA levels, indicated high MAA levels in mucus, whereas gnathiids had no detectable MAAs. This suggests that La. dimidiatus obtain MAAs from mucus but not from gnathiids. Hence, in addition to energy, the mucus of some clients also provides La. dimidiatus with the added bonus of UV-absorbing compounds. This may explain why cleaner fish prefer to feed on mucus over gnathiid isopods. The likely costs and benefits to clients of the removal of UV protecting mucus and parasitic gnathiids, respectively, and the variation in benefits gained by cleaner fish from feeding on these foods may explain some variation in cooperation levels in cleaning interactions.

Comparative studies on Aedes aegypti and Aedes albopictus adult females trespassing commercial nets.

PubMed

Andrade, Carlos F S; Cabrini, Isaías

2010-03-01

ABSTRACT. The abilities of Aedes aegypti and Ae. albopictus females in trespassing 5 different commercial nets, 2 nets impregnated with deltamethrin or permethrin and 3 non-impregnated nets (Guarany, Perame, and Ricca), were compared. The evaluating parameters were their percent trespassing success, the median trespassing time (TT50), and the relation between mosquito wing sizes and their trespassing success. Some mosquito behavioral traits were also observed. The trespassing success, directly related to opening areas, was found to be lower with impregnated nets for both species. The differences between the mosquito species were significant among all the nets except Ricca. Aedes albopictus showed a very high success rate in trespassing the non-impregnated Perame net and a lower success rate in trespassing Guarany. Aedes albopictus also showed a very high success rate in trespassing pyrethroid-impregnated nets. The TT50 values for the Ricca and Guarany nets were not significantly different between the species, but a significantly lower TT50 value was found for the net with the largest opening (Ricca). The smaller wingspan of Ae. albopictus seems to explain the higher trespassing success of this species.

Impact of metal gates on remote phonon scattering in titanium nitride/hafnium dioxide n-channel metal-oxide-semiconductor field effect transistors-low temperature electron mobility study

NASA Astrophysics Data System (ADS)

Maitra, Kingsuk; Frank, Martin M.; Narayanan, Vijay; Misra, Veena; Cartier, Eduard A.

2007-12-01

We report low temperature (40-300 K) electron mobility measurements on aggressively scaled [equivalent oxide thickness (EOT)=1 nm] n-channel metal-oxide-semiconductor field effect transistors (nMOSFETs) with HfO2 gate dielectrics and metal gate electrodes (TiN). A comparison is made with conventional nMOSFETs containing HfO2 with polycrystalline Si (poly-Si) gate electrodes. No substantial change in the temperature acceleration factor is observed when poly-Si is replaced with a metal gate, showing that soft optical phonons are not significantly screened by metal gates. A qualitative argument based on an analogy between remote phonon scattering and high-resolution electron energy-loss spectroscopy (HREELS) is provided to explain the underlying physics of the observed phenomenon. It is also shown that soft optical phonon scattering is strongly damped by thin SiO2 interface layers, such that room temperature electron mobility values at EOT=1 nm become competitive with values measured in nMOSFETs with SiON gate dielectrics used in current high performance processors.

Petrogenesis of KREEP

NASA Technical Reports Server (NTRS)

Mckay, G. A.; Weill, D. F.

1975-01-01

Solid/liquid distribution coefficients (weight basis) were experimentally determined for a number of trace elements for olivine, orthopyroxene, plagioclase and ilmenite. Values of distribution coefficients were measured at 1200 C and a f sub O2 of 10 to the -13.0 power for liquids similar in composition to the olivine-opx-plagioclase peritectic in the pseudoternary system (Fe,Mg)2SiO4-CaAl2Si2O8-SiO2. Values were also measured at 1140 C and a f sub O2 of 10 to the -12.8 power for liquids similar in composition to high-Ti mare basalts. Major and trace element partitioning and relevant phase equilibria were used to investigate possible parent-daughter relationships between a number of highland samples and highly evolved KREEP-rich materials. Out of about 80 highlands samples tested, 33 were found to be possible parents to the KREEP-rich materials. The average composition of these samples is very similar to that of the Low-K Fra Mauro basalt (LKFM). A model is proposed to explain the production of LKFM-type material and more evolved members of the KREEP suite.

Optimization of tannase production by a novel Klebsiella pneumoniae KP715242 using central composite design.

PubMed

Kumar, Mukesh; Rana, Shiny; Beniwal, Vikas; Salar, Raj Kumar

2015-09-01

A novel tannase producing bacterial strain was isolated from rhizospheric soil of Acacia species and identified as Klebsiella pneumoniae KP715242. A 3.25-fold increase in tannase production was achieved upon optimization with central composite design using response surface methodology. Four variables namely pH, temperature, incubation period, and agitation speed were used to optimize significant correlation between the effects of these variables on tannase production. A second-order polynomial was fitted to data and validated by ANOVA. The results showed a complex relationship between variables and response given that all factors were significant and could explain 99.6% of the total variation. The maximum production was obtained at 5.2 pH, 34.97 °C temperature, 103.34 rpm agitation speed and 91.34 h of incubation time. The experimental values were in good agreement with the predicted ones and the models were highly significant with a correlation coefficient ( R 2 ) of 0.99 and a highly significant F-value of 319.37.

Structure-Activity Relationship of the Antimalarial Ozonide Artefenomel (OZ439).

PubMed

Dong, Yuxiang; Wang, Xiaofang; Kamaraj, Sriraghavan; Bulbule, Vivek J; Chiu, Francis C K; Chollet, Jacques; Dhanasekaran, Manickam; Hein, Christopher D; Papastogiannidis, Petros; Morizzi, Julia; Shackleford, David M; Barker, Helena; Ryan, Eileen; Scheurer, Christian; Tang, Yuanqing; Zhao, Qingjie; Zhou, Lin; White, Karen L; Urwyler, Heinrich; Charman, William N; Matile, Hugues; Wittlin, Sergio; Charman, Susan A; Vennerstrom, Jonathan L

2017-04-13

Building on insights gained from the discovery of the antimalarial ozonide arterolane (OZ277), we now describe the structure-activity relationship (SAR) of the antimalarial ozonide artefenomel (OZ439). Primary and secondary amino ozonides had higher metabolic stabilities than tertiary amino ozonides, consistent with their higher pK a and lower log D 7.4 values. For primary amino ozonides, addition of polar functional groups decreased in vivo antimalarial efficacy. For secondary amino ozonides, additional functional groups had variable effects on metabolic stability and efficacy, but the most effective members of this series also had the highest log D 7.4 values. For tertiary amino ozonides, addition of polar functional groups with H-bond donors increased metabolic stability but decreased in vivo antimalarial efficacy. Primary and tertiary amino ozonides with cycloalkyl and heterocycle substructures were superior to their acyclic counterparts. The high curative efficacy of these ozonides was most often associated with high and prolonged plasma exposure, but exposure on its own did not explain the presence or absence of either curative efficacy or in vivo toxicity.

Atmospheric levels of aldehydes and BTEX and their relationship with vehicular fleet changes in Rio de Janeiro urban area.

PubMed

Martins, Eduardo Monteiro; Arbilla, Graciela; Bauerfeldt, Glauco Favilla; de Paula, Murilo

2007-05-01

A comprehensive monitoring campaign to assess aldehydes and BTEX concentrations was performed during 12 months, in the Tijuca district (Rio de Janeiro), an area with commercial activities and a high flux of vehicles. The mean concentrations of formaldehyde and acetaldehyde were 151 and 30 ppb, respectively. The high formaldehyde/acetaldehyde ratio was attributed to extensive use of compressed natural gas (CNG). The number of CNG vehicles in the metropolitan Region of Rio de Janeiro increased from 23000 in January 2001 to 161000 in January 2005. Monitoring data show that, for the same period, methane and formaldehyde concentrations increased while NO(x) and CO levels diminished. Mean concentrations for benzene, toluene, ethylbenzene, m,p-xylene and o-xylene, were 1.1, 4.8, 3.6, 10.4 and 3.0 micro gm(-3), respectively. Benzene and toluene concentrations were lower than the values determined in 1996, for the same location. The levels of ethylbenzene and xylenes determined in this work are similar to values obtained in 1996. This fact may be explained as a consequence of changes in the gasoline composition.

Status of HgCdTe Barrier Infrared Detectors Grown by MOCVD in Military University of Technology

NASA Astrophysics Data System (ADS)

Kopytko, M.; Jóźwikowski, K.; Martyniuk, P.; Gawron, W.; Madejczyk, P.; Kowalewski, A.; Markowska, O.; Rogalski, A.; Rutkowski, J.

2016-09-01

In this paper we present the status of HgCdTe barrier detectors with an emphasis on technological progress in metalorganic chemical vapor deposition (MOCVD) growth achieved recently at the Institute of Applied Physics, Military University of Technology. It is shown that MOCVD technology is an excellent tool for HgCdTe barrier architecture growth with a wide range of composition, donor /acceptor doping, and without post-grown annealing. The device concept of a specific barrier bandgap architecture integrated with Auger-suppression is as a good solution for high-operating temperature infrared detectors. Analyzed devices show a high performance comparable with the state-of-the-art of HgCdTe photodiodes. Dark current densities are close to the values given by "Rule 07" and detectivities of non-immersed detectors are close to the value marked for HgCdTe photodiodes. Experimental data of long-wavelength infrared detector structures were confirmed by numerical simulations obtained by a commercially available software APSYS platform. A detailed analysis applied to explain dark current plots was made, taking into account Shockley-Read-Hall, Auger, and tunneling currents.

Low Impact of Traditional Risk Factors on Carotid Intima-Media Thickness: The ELSA-Brasil Cohort.

PubMed

Santos, Itamar S; Alencar, Airlane P; Rundek, Tatjana; Goulart, Alessandra C; Barreto, Sandhi M; Pereira, Alexandre C; Benseñor, Isabela M; Lotufo, Paulo A

2015-09-01

There is little information about how much traditional cardiovascular risk factors explain common carotid artery intima-media thickness (CCA-IMT) variance. We aimed to study to which extent CCA-IMT values are determined by traditional risk factors and which commonly used measurements of blood pressure, glucose metabolism, lipid profile, and adiposity contribute the most to this determination in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) cohort baseline. We analyzed 9792 individuals with complete data and CCA-IMT measurements. We built multiple linear regression models using mean left and right CCA-IMT as the dependent variable. All models were stratified by sex. We also analyzed individuals stratified by 10-year coronary heart disease risk and, in separate, those with no traditional risk factors. Main models' R(2) varied between 0.141 and 0.373. The major part of the explained variance in CCA-IMT was because of age and race. Indicators of blood pressure, lipid profile, and adiposity that most frequently composed the best models were pulse pressure, low-density lipoprotein/high-density lipoprotein ratio, and neck circumference. The association between neck circumference and CCA-IMT persisted significant even after further adjustment for vessel sizes and body mass index. Indicators of glucose metabolism had smaller contribution. We found that >60% of CCA-IMT were not explained by demographic and traditional cardiovascular risk factors, which highlights the need to study novel risk factors. Pulse pressure, low-density lipoprotein/high-density lipoprotein ratio, and neck circumference were the most consistent contributors. © 2015 American Heart Association, Inc.

Multiphysics modeling of two-phase film boiling within porous corrosion deposits

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

Jin, Miaomiao, E-mail: mmjin@mit.edu; Short, Michael, E-mail: hereiam@mit.edu

2016-07-01

Porous corrosion deposits on nuclear fuel cladding, known as CRUD, can cause multiple operational problems in light water reactors (LWRs). CRUD can cause accelerated corrosion of the fuel cladding, increase radiation fields and hence greater exposure risk to plant workers once activated, and induce a downward axial power shift causing an imbalance in core power distribution. In order to facilitate a better understanding of CRUD's effects, such as localized high cladding surface temperatures related to accelerated corrosion rates, we describe an improved, fully-coupled, multiphysics model to simulate heat transfer, chemical reactions and transport, and two-phase fluid flow within these deposits.more » Our new model features a reformed assumption of 2D, two-phase film boiling within the CRUD, correcting earlier models' assumptions of single-phase coolant flow with wick boiling under high heat fluxes. This model helps to better explain observed experimental values of the effective CRUD thermal conductivity. Finally, we propose a more complete set of boiling regimes, or a more detailed mechanism, to explain recent CRUD deposition experiments by suggesting the new concept of double dryout specifically in thick porous media with boiling chimneys. - Highlights: • A two-phase model of CRUD's effects on fuel cladding is developed and improved. • This model eliminates the formerly erroneous assumption of wick boiling. • Higher fuel cladding temperatures are predicted when accounting for two-phase flow. • Double-peaks in thermal conductivity vs. heat flux in experiments are explained. • A “double dryout” mechanism in CRUD is proposed based on the model and experiments.« less

Composite Quality Measures for Common Inpatient Medical Conditions

PubMed Central

Chen, Lena M.; Staiger, Douglas O.; Birkmeyer, John D.; Ryan, Andrew M.; Zhang, Wenying; Dimick, Justin B.

2014-01-01

Background Public reporting on quality aims to help patients select better hospitals. However, individual quality measures are sub-optimal in identifying superior and inferior hospitals based on outcome performance. Objective To combine structure, process, and outcome measures into an empirically-derived composite quality measure for heart failure (HF), acute myocardial infarction (AMI), and pneumonia (PNA). To assess how well the composite measure predicts future high and low performers, and explains variance in future hospital mortality. Research Design Using national Medicare data, we created a cohort of older patients treated at an acute care hospital for HF (n=1,203,595), AMI (n=625,595), or PNA (n=1,234,299). We ranked hospitals based on their July 2005 to June 2008 performance on the composite. We then estimated the odds of future (July to December 2009) 30-day, risk-adjusted mortality at the worst vs. best quintile of hospitals. We repeated this analysis using 2005-2008 performance on existing quality indicators, including mortality. Results The composite (vs. Hospital Compare) explained 68% (vs. 39%) of variation in future AMI mortality rates. In 2009, if an AMI patient had chosen a hospital in the worst vs. best quintile of performance using 2005-2008 composite (vs. Hospital Compare) rankings, he or she would have had 1.61 (vs. 1.39) times the odds of dying in 30 days (p-value for difference < 0.001). Results were similar for HF and PNA. Conclusions Composite measures of quality for HF, AMI, and PNA performed better than existing measures at explaining variation in future mortality and predicting future high and low performers. PMID:23942222

TEMPORAL VARIABILITY FROM THE TWO-COMPONENT ADVECTIVE FLOW SOLUTION AND ITS OBSERVATIONAL EVIDENCE

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

Dutta, Broja G.; Chakrabarti, Sandip K.

2016-09-10

In the propagating oscillatory shock model, the oscillation of the post-shock region, i.e., the Compton cloud, causes the observed low-frequency quasi-periodic oscillations (QPOs). The evolution of QPO frequency is explained by the systematic variation of the Compton cloud size, i.e., the steady radial movement of the shock front, which is triggered by the cooling of the post-shock region. Thus, analysis of the energy-dependent temporal properties in different variability timescales can diagnose the dynamics and geometry of accretion flows around black holes. We study these properties for the high-inclination black hole source XTE J1550-564 during its 1998 outburst and the low-inclinationmore » black hole source GX 339-4 during its 2006–07 outburst using RXTE /PCA data, and we find that they can satisfactorily explain the time lags associated with the QPOs from these systems. We find a smooth decrease of the time lag as a function of time in the rising phase of both sources. In the declining phase, the time lag increases with time. We find a systematic evolution of QPO frequency and hard lags in these outbursts. In XTE J1550-564, the lag changes from hard to soft (i.e., from a positive to a negative value) at a crossing frequency (ν {sub c}) of ∼3.4 Hz. We present possible mechanisms to explain the lag behavior of high and low-inclination sources within the framework of a single two-component advective flow model.« less

Sorption of polycyclic aromatic hydrocarbons to polystyrene nanoplastic.

PubMed

Liu, Lijing; Fokkink, Remco; Koelmans, Albert A

2016-07-01

Microplastic has become an emerging contaminant of global concern. Bulk plastic can degrade to form smaller particles down to the nanoscale (<100 nm), which are referred to as nanoplastics. Because of their high surface area, nanoplastic may bind hydrophobic chemicals very effectively, increasing their hazard when such nanoplastics are taken up by biota. The present study reports distribution coefficients for sorption of polycyclic aromatic hydrocarbons (PAHs) to 70 nm polystyrene in freshwater, and PAH adsorption isotherms spanning environmentally realistic aqueous concentrations of 10(-5)  μg/L to 1 μg/L. Nanopolystyrene aggregate state was assessed using dynamic light scattering. The adsorption isotherms were nonlinear, and the distribution coefficients at the lower ends of the isotherms were very high, with values up to 10(9) L/kg. The high and nonlinear sorption was explained from π-π interactions between the planar PAHs and the surface of the aromatic polymer polystyrene and was higher than for micrometer-sized polystyrene. Reduction of nanopolystyrene aggregate sizes had no significant effect on sorption, which suggests that the PAHs could reach the sorption sites on the pristine nanoparticles regardless of the aggregation state. Pre-extraction of the nanopolystyrene with C18 polydimethylsiloxane decreased sorption of PAHs, which could be explained by removal of the most hydrophobic fraction of the nanopolystyrene. Environ Toxicol Chem 2016;35:1650-1655. © 2015 SETAC. © 2015 SETAC.

Physical fitness predicts technical-tactical and time-motion profile in simulated Judo and Brazilian Jiu-Jitsu matches.

PubMed

Coswig, Victor S; Gentil, Paulo; Bueno, João C A; Follmer, Bruno; Marques, Vitor A; Del Vecchio, Fabrício B

2018-01-01

Among combat sports, Judo and Brazilian Jiu-Jitsu (BJJ) present elevated physical fitness demands from the high-intensity intermittent efforts. However, information regarding how metabolic and neuromuscular physical fitness is associated with technical-tactical performance in Judo and BJJ fights is not available. This study aimed to relate indicators of physical fitness with combat performance variables in Judo and BJJ. The sample consisted of Judo ( n  = 16) and BJJ ( n  = 24) male athletes. At the first meeting, the physical tests were applied and, in the second, simulated fights were performed for later notational analysis. The main findings indicate: (i) high reproducibility of the proposed instrument and protocol used for notational analysis in a mobile device; (ii) differences in the technical-tactical and time-motion patterns between modalities; (iii) performance-related variables are different in Judo and BJJ; and (iv) regression models based on metabolic fitness variables may account for up to 53% of the variances in technical-tactical and/or time-motion variables in Judo and up to 31% in BJJ, whereas neuromuscular fitness models can reach values up to 44 and 73% of prediction in Judo and BJJ, respectively. When all components are combined, they can explain up to 90% of high intensity actions in Judo. In conclusion, performance prediction models in simulated combat indicate that anaerobic, aerobic and neuromuscular fitness variables contribute to explain time-motion variables associated with high intensity and technical-tactical variables in Judo and BJJ fights.

Influence of traditional markets on plant management in the Tehuacán Valley.

PubMed

Arellanes, Yaayé; Casas, Alejandro; Arellanes, Anselmo; Vega, Ernesto; Blancas, José; Vallejo, Mariana; Torres, Ignacio; Rangel-Landa, Selene; Moreno, Ana I; Solís, Leonor; Pérez-Negrón, Edgar

2013-06-01

The Tehuacán Valley, Mexico is a region with exceptionally high biocultural richness. Traditional knowledge in this region comprises information on nearly 1,600 plant species used by local peoples to satisfy their subsistence needs. Plant resources with higher cultural value are interchanged in traditional markets. We inventoried the edible plant species interchanged in regional markets documenting economic, cultural and ecological data and about their extraction and management in order to: (1) assess how commercialization and ecological aspects influence plant management, (2) identify which species are more vulnerable, and (3) analyze how local management contributes to decrease their risk. We hypothesized that scarcer plant species with higher economic value would be under higher pressure motivating more management actions than on more abundant plants with lower economic value. However, construction of management techniques is also influenced by the time-span the management responses have taken as well as biological and ecological aspects of the plant species that limit the implementation of management practices. Plant management mitigates risk, but its absence on plant species under high risk may favor local extinction. Six traditional markets were studied through 332 semi-structured interviews to local vendors about barter, commercialization, and management types of local edible plant species. We retrieved ethnobotanical information on plant management from ten communities in a workshop and sampled regional vegetation in a total of 98 sites to estimate distribution and abundance of plant species commercialized. Through Canonical Correspondence Analysis (CCA) we analyzed the amount of variation of management types that can be explained from socioeconomic and ecological information. A risk index was calculated relating distribution, abundance, economic value and management of plant resources to identify the most vulnerable species. We recorded 122 edible plant species interchanged in the main regional markets. CCA explained significantly 24% of management variation, spatial distribution and plant parts used being particularly important in management decisions. The indeterminate 76% of variation suggests that management decisions depend on particular variables that are not explained by the ecological and socioeconomic factors studied and/or their high variation in the context at the regional scale. The risk index indicated that management was the factor that mostly influences decreasing of risk of interchanged plant species. We identified Clinopodium mexicanum, Pachycereus weberi, Dasylirion serratifolium, Disocorea sp., Ceiba aesculifolia, Neobuxbamia tetetzo, Lippia graveolens, Litsea glaucescens, L. neesiana, Jatropha neopauciflora, Agave potatorum and other agave species used for producing mescal among the more endangered plant species due to human pressure, their relative scarcity and limited or inexistent management. Spatial distribution and plant parts used are particularly meaningful factors determining risk and influencing management actions on edible plant species interchanged in the region. Limited or inexistent management may favor extinction of local populations under risk. Local management techniques synthesize knowledge and experiences crucial for designing sustainable management programs. Traditional management techniques supported by ecological information and environmental management approaches could make valuable contributions for sustainable use of plant species, particularly those becoming economically important more recently.

Influence of traditional markets on plant management in the Tehuacán Valley

PubMed Central

2013-01-01

Background The Tehuacán Valley, Mexico is a region with exceptionally high biocultural richness. Traditional knowledge in this region comprises information on nearly 1,600 plant species used by local peoples to satisfy their subsistence needs. Plant resources with higher cultural value are interchanged in traditional markets. We inventoried the edible plant species interchanged in regional markets documenting economic, cultural and ecological data and about their extraction and management in order to: (1) assess how commercialization and ecological aspects influence plant management, (2) identify which species are more vulnerable, and (3) analyze how local management contributes to decrease their risk. We hypothesized that scarcer plant species with higher economic value would be under higher pressure motivating more management actions than on more abundant plants with lower economic value. However, construction of management techniques is also influenced by the time-span the management responses have taken as well as biological and ecological aspects of the plant species that limit the implementation of management practices. Plant management mitigates risk, but its absence on plant species under high risk may favor local extinction. Methods Six traditional markets were studied through 332 semi-structured interviews to local vendors about barter, commercialization, and management types of local edible plant species. We retrieved ethnobotanical information on plant management from ten communities in a workshop and sampled regional vegetation in a total of 98 sites to estimate distribution and abundance of plant species commercialized. Through Canonical Correspondence Analysis (CCA) we analyzed the amount of variation of management types that can be explained from socioeconomic and ecological information. A risk index was calculated relating distribution, abundance, economic value and management of plant resources to identify the most vulnerable species. Results We recorded 122 edible plant species interchanged in the main regional markets. CCA explained significantly 24% of management variation, spatial distribution and plant parts used being particularly important in management decisions. The indeterminate 76% of variation suggests that management decisions depend on particular variables that are not explained by the ecological and socioeconomic factors studied and/or their high variation in the context at the regional scale. The risk index indicated that management was the factor that mostly influences decreasing of risk of interchanged plant species. We identified Clinopodium mexicanum, Pachycereus weberi, Dasylirion serratifolium, Disocorea sp., Ceiba aesculifolia, Neobuxbamia tetetzo, Lippia graveolens, Litsea glaucescens, L. neesiana, Jatropha neopauciflora, Agave potatorum and other agave species used for producing mescal among the more endangered plant species due to human pressure, their relative scarcity and limited or inexistent management. Conclusion Spatial distribution and plant parts used are particularly meaningful factors determining risk and influencing management actions on edible plant species interchanged in the region. Limited or inexistent management may favor extinction of local populations under risk. Local management techniques synthesize knowledge and experiences crucial for designing sustainable management programs. Traditional management techniques supported by ecological information and environmental management approaches could make valuable contributions for sustainable use of plant species, particularly those becoming economically important more recently. PMID:23725352

Improved explanation of human intelligence using cortical features with second order moments and regression.

PubMed

Park, Hyunjin; Yang, Jin-ju; Seo, Jongbum; Choi, Yu-yong; Lee, Kun-ho; Lee, Jong-min

2014-04-01

Cortical features derived from magnetic resonance imaging (MRI) provide important information to account for human intelligence. Cortical thickness, surface area, sulcal depth, and mean curvature were considered to explain human intelligence. One region of interest (ROI) of a cortical structure consisting of thousands of vertices contained thousands of measurements, and typically, one mean value (first order moment), was used to represent a chosen ROI, which led to a potentially significant loss of information. We proposed a technological improvement to account for human intelligence in which a second moment (variance) in addition to the mean value was adopted to represent a chosen ROI, so that the loss of information would be less severe. Two computed moments for the chosen ROIs were analyzed with partial least squares regression (PLSR). Cortical features for 78 adults were measured and analyzed in conjunction with the full-scale intelligence quotient (FSIQ). Our results showed that 45% of the variance of the FSIQ could be explained using the combination of four cortical features using two moments per chosen ROI. Our results showed improvement over using a mean value for each ROI, which explained 37% of the variance of FSIQ using the same set of cortical measurements. Our results suggest that using additional second order moments is potentially better than using mean values of chosen ROIs for regression analysis to account for human intelligence. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relationship between leaf functional traits and productivity in Aquilaria crassna (Thymelaeaceae) plantations: a tool to aid in the early selection of high-yielding trees.

PubMed

López-Sampson, Arlene; Cernusak, Lucas A; Page, Tony

2017-05-01

Physiological traits are frequently used as indicators of tree productivity. Aquilaria species growing in a research planting were studied to investigate relationships between leaf-productivity traits and tree growth. Twenty-eight trees were selected to measure isotopic composition of carbon (δ13C) and nitrogen (δ15N) and monitor six leaf attributes. Trees were sampled randomly within each of four diametric classes (at 150 mm above ground level) ensuring the variability in growth of the whole population was represented. A model averaging technique based on the Akaike's information criterion was computed to identify whether leaf traits could assist in diameter prediction. Regression analysis was performed to test for relationships between carbon isotope values and diameter and leaf traits. Approximately one new leaf per week was produced by a shoot. The rate of leaf expansion was estimated as 1.45 mm day-1. The range of δ13C values in leaves of Aquilaria species was from -25.5‰ to -31‰, with an average of -28.4 ‰ (±1.5‰ SD). A moderate negative correlation (R2 = 0.357) between diameter and δ13C in leaf dry matter indicated that individuals with high intercellular CO2 concentrations (low δ13C) and associated low water-use efficiency sustained rapid growth. Analysis of the 95% confidence of best-ranked regression models indicated that the predictors that could best explain growth in Aquilaria species were δ13C, δ15N, petiole length, number of new leaves produced per week and specific leaf area. The model constructed with these variables explained 55% (R2 = 0.55) of the variability in stem diameter. This demonstrates that leaf traits can assist in the early selection of high-productivity trees in Aquilaria species. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Reviews

NASA Astrophysics Data System (ADS)

2005-05-01

WE RECOMMEND Private Universe and Minds of Our Own This DVD for teachers addresses challenges faced in the classroom. EasySenseLink and EasySense Flash Logger These two dataloggers are fast, versatile and inexpensive. The Butthead Game, Space Rifle and Disc Shooter Together, these toys can be used to explain the photoelectric effect. Resistance and thickness boards These high-quality, value-for-money boards produce excellent results. WORTH A LOOK Einstein A to Z A useful and well researched text about EinsteinÂ's life and work. Einstein Alive Depending on how it is lit, this display can look concave or convex. Phyzzing Through Physics As PowerPoint presentations go, this one is useful and good value. HANDLE WITH CARE Pressure toadstools An overpriced tool that you could make yourself using dowelling. Parallel and series boards Easily damaged, these boards are best used in demonstrations only. WEB WATCH Educational websites that make electricity fun to learn. Applets website: an online gem for teachers.

A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician seawater temperatures and isotopic composition

NASA Astrophysics Data System (ADS)

Bergmann, Kristin D.; Finnegan, Seth; Creel, Roger; Eiler, John M.; Hughes, Nigel C.; Popov, Leonid E.; Fischer, Woodward W.

2018-03-01

The secular increase in δ18O values of both calcitic and phosphatic marine fossils through early Phanerozoic time suggests either that (1) early Paleozoic surface temperatures were high, in excess of 40 °C (tropical MAT), (2) the δ18O value of seawater has increased by 7-8‰ VSMOW through Paleozoic time, or (3) diagenesis has altered secular trends in early Paleozoic samples. Carbonate clumped isotope analysis, in combination with petrographic and elemental analysis, can deconvolve fluid composition from temperature effects and therefore determine which of these hypotheses best explain the secular δ18O increase. Clumped isotope measurements of a suite of calcitic and phosphatic marine fossils from late Cambrian- to Middle-late Ordovician-aged strata-the first paired fossil study of its kind-document tropical sea surface temperatures near modern temperatures (26-38 °C) and seawater oxygen isotope ratios similar to today's ratios.

Postinflationary Higgs relaxation and the origin of matter-antimatter asymmetry.

PubMed

Kusenko, Alexander; Pearce, Lauren; Yang, Louis

2015-02-13

The recent measurement of the Higgs boson mass implies a relatively slow rise of the standard model Higgs potential at large scales, and a possible second minimum at even larger scales. Consequently, the Higgs field may develop a large vacuum expectation value during inflation. The relaxation of the Higgs field from its large postinflationary value to the minimum of the effective potential represents an important stage in the evolution of the Universe. During this epoch, the time-dependent Higgs condensate can create an effective chemical potential for the lepton number, leading to a generation of the lepton asymmetry in the presence of some large right-handed Majorana neutrino masses. The electroweak sphalerons redistribute this asymmetry between leptons and baryons. This Higgs relaxation leptogenesis can explain the observed matter-antimatter asymmetry of the Universe even if the standard model is valid up to the scale of inflation, and any new physics is suppressed by that high scale.

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

Fahr, H. J.; Krimigis, S. M.; Fichtner, H.

The study addresses the question of the origin of low-energy electrons measured by Voyager 1 in the multi-keV range in the inner heliosheath. It intends to demonstrate that the observed keV-fluxes of electrons are consistent with their transmission through the termination shock under the influence of the associated electrostatic field. A power-law representation of the electron velocity distribution just downstream of the solar wind termination shock is motivated and formulated in terms of a so-called κ -distribution function. From this initial function spectral electron fluxes in the range 40–70 keV are derived and compared to the data. It is shownmore » that with κ -values between 7 and 8 the data can be satisfactorily explained. Given these comparatively high κ -values, it is concluded that the electron distribution just downstream of the termination shock relaxes toward but does not reach a Maxwellian shape in the inner heliosheath.« less

Observation of a thermally enhanced magnetoresistance in NiFe

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

Cao, Y.; Feng, C., E-mail: fengchun@ustb.edu.cn, E-mail: ghyu@mater.ustb.edu.cn; Liu, D. X.

2016-04-15

A thermally enhanced magnetoresistance (ThMR) was designed and obtained by simultaneously applying charge and heat currents to a NiFe thin film. From the measurement we observed that the magnetoresistance value was as high as -22600% when the input charge current and applied temperature gradient was 0.966 μA and 2.5 °C/mm, respectively. This ThMR can be controllable by adjusting the relative values of the input charge and heat currents. On increasing the input charge current from 0.85 to 1.05 μA by fixing the temperature gradient at 2.5 °C/mm, the ThMR first increased from 9% to 183% and then decreased from -259%more » to -13%, at intervals of ∼0.96 μA. This can be explained by the spin-dependent transport phenomenon i.e., scattering induced sign difference between magnetoresistance and magnetothermopower in NiFe.« less

Edge currents shunt the insulating bulk in gapped graphene

NASA Astrophysics Data System (ADS)

Zhu, M. J.; Kretinin, A. V.; Thompson, M. D.; Bandurin, D. A.; Hu, S.; Yu, G. L.; Birkbeck, J.; Mishchenko, A.; Vera-Marun, I. J.; Watanabe, K.; Taniguchi, T.; Polini, M.; Prance, J. R.; Novoselov, K. S.; Geim, A. K.; Ben Shalom, M.

2017-02-01

An energy gap can be opened in the spectrum of graphene reaching values as large as 0.2 eV in the case of bilayers. However, such gaps rarely lead to the highly insulating state expected at low temperatures. This long-standing puzzle is usually explained by charge inhomogeneity. Here we revisit the issue by investigating proximity-induced superconductivity in gapped graphene and comparing normal-state measurements in the Hall bar and Corbino geometries. We find that the supercurrent at the charge neutrality point in gapped graphene propagates along narrow channels near the edges. This observation is corroborated by using the edgeless Corbino geometry in which case resistivity at the neutrality point increases exponentially with increasing the gap, as expected for an ordinary semiconductor. In contrast, resistivity in the Hall bar geometry saturates to values of about a few resistance quanta. We attribute the metallic-like edge conductance to a nontrivial topology of gapped Dirac spectra.

Different Types of X-Ray Bursts from GRS 1915+105 and Their Origin

NASA Astrophysics Data System (ADS)

Yadav, J. S.; Rao, A. R.; Agrawal, P. C.; Paul, B.; Seetha, S.; Kasturirangan, K.

1999-06-01

We report X-ray observations of the Galactic X-ray transient source GRS 1915+105 with the pointed proportional counters of the Indian X-ray Astronomy Experiment (IXAE) onboard the Indian satellite IRS-P3, which show remarkable richness in temporal variability. The observations were carried out on 1997 June 12-29 and August 7-10, in the energy range of 2-18 keV and revealed the presence of very intense X-ray bursts. All the observed bursts have a slow exponential rise, a sharp linear decay, and broadly can be put in two classes: irregular and quasi-regular bursts in one class, and regular bursts in the other. The regular bursts are found to have two distinct timescales and to persist over extended durations. There is a strong correlation between the preceding quiescent time and the burst duration for the quasi-regular and irregular bursts. No such correlation is found for the regular bursts. The ratio of average flux during the burst time to the average flux during the quiescent phase is high and variable for the quasi-regular and irregular bursts, while it is low and constant for the regular bursts. We present a comprehensive picture of the various types of bursts observed in GRS 1915+105 in the light of the recent theories of advective accretion disks. We suggest that the peculiar bursts that we have seen are characteristic of the change of state of the source. The source can switch back and forth between the low-hard state and the high-soft state near critical accretion rates in a very short timescale, giving rise to the irregular and quasi-regular bursts. The fast timescale for the transition of the state is explained by invoking the appearance and disappearance of the advective disk in its viscous timescale. The periodicity of the regular bursts is explained by matching the viscous timescale with the cooling timescale of the postshock region. A test of the model is presented using the publicly available 13-60 keV RXTE/PCA data for irregular and regular bursts concurrent with our observations. It is found that the 13-60 keV flux relative to the 2-13 keV flux shows clear evidence for state change between the quiescent phase and the burst phase. The value of this ratio during burst is consistent with the values observed during the high-soft state seen on 1997 August 19, while its value during quiescent phase is consistent with the values observed during the low-hard state seen on 1997 May 8.

Magnetised Strings in Λ-Dominated Anisotropic Universe

NASA Astrophysics Data System (ADS)

Goswami, G. K.; Yadav, Anil Kumar; Dewangan, R. N.

2016-11-01

In this paper, we have searched the existence of Λ-dominated anisotropic universe filled with magnetized strings. The observed acceleration of universe has been explained by introducing a positive cosmological constant Λ in the Einstein's field equation which is mathematically equivalent to dark energy with equation of state (EOS) parameter set equal to -1. The present values of the matter and the dark energy parameters (Ω m )0 & (ΩΛ)0 are estimated for high red shift (.3 ≤ z ≤ 1.4) SN Ia supernova data's of observed apparent magnitude along with their possible error taken from Union 2.1 compilation. It is found that the best fit value for (Ω m )0 & (ΩΛ)0 are 0.2920 & 0.7076 respectively which are in good agreement with recent astrophysical observations in the latest surveys like WMAP and Plank. Various physical parameters such as the matter and dark energy densities, the present age of the universe and the present value of deceleration parameter have been obtained on the basis of the values of (Ω m )0 & (ΩΛ)0.Also, we have estimated that the acceleration would have begun in the past at z = 0.6845 i. e. 6.2341 Gyrs before from now.

Effect of Bimodal Grain Size Distribution on Scatter in Toughness

NASA Astrophysics Data System (ADS)

Chakrabarti, Debalay; Strangwood, Martin; Davis, Claire

2009-04-01

Blunt-notch tests were performed at -160 °C to investigate the effect of a bimodal ferrite grain size distribution in steel on cleavage fracture toughness, by comparing local fracture stress values for heat-treated microstructures with uniformly fine, uniformly coarse, and bimodal grain structures. An analysis of fracture stress values indicates that bimodality can have a significant effect on toughness by generating high scatter in the fracture test results. Local cleavage fracture values were related to grain size distributions and it was shown that the largest grains in the microstructure, with an area percent greater than approximately 4 pct, gave rise to cleavage initiation. In the case of the bimodal grain size distribution, the large grains from both the “fine grain” and “coarse grain” population initiate cleavage; this spread in grain size values resulted in higher scatter in the fracture stress than in the unimodal distributions. The notch-bend test results have been used to explain the difference in scatter in the Charpy energies for the unimodal and bimodal ferrite grain size distributions of thermomechanically controlled rolled (TMCR) steel, in which the bimodal distribution showed higher scatter in the Charpy impact transition (IT) region.

Microearthquake spectra from the Anza, California, seismic network: site response and source scaling

USGS Publications Warehouse

Frankel, Arthur D.; Wennerberg, Leif

1989-01-01

We analyzed spectra of local microearthquakes recorded by the Anza, California, seismic network to isolate the effects of site response and to investigate the scaling of source parameters for small earthquakes. Spectra of microearthquakes (M < 2; Mo< 1019 dyne-cm) at Anza have shapes characteristic of the receiver sites and are generally independent of the source region. Thus, the site response is a major conditioner of the observed spectral shape. To remove the effects of site response from the spectra of a M ∼ 3 event and isolate its source spectrum, we divided by the spectra of an adjacent aftershock used as an empirical Green's function event. The spectral ratios indicate that the apparent corner frequencies of small earthquakes (Mo < 1019dyne-cm) observed at even the high-fmax stations on hard rock are much lower than the source corner frequencies. The spectral ratios are consistent with stress drop remaining constant with decreasing seismic moment, for events with moments as small as 1018 dyne-cm. The spectral ratios display remarkable agreement between sites which showed vast differences in their original spectra, indicating that the spectral division effectively removed the site response. The source spectrum of the M ∼ 3 event has a high-frequency spectral fall-off of about ω−2. An apparent dependence of high-frequency fall-off with seismic moment in the original spectra can also be explained by the effects of site response. The difference between the P- and S-wave corner frequencies and high-frequency roll-offs in the observed spectra for these events is the result of the site response and is not a source property. The shapes of the spectra of microearthquakes at Anza can largely be explained by attenuation at shallow depth with a frequency-independent Q. For some sites, near-surface resonances are also apparent in the spectra of microearthquakes. It is indicated by t* values determined for each site that Qp ∼ Qsfor the shallow low-Q layer. Further evidence of low near-surface Q is observed in the anomalous spectra of an unusually shallow earthquake (source depth ∼ 1 km) in the network. The spectra from this shallow event are depleted in high-frequency energy at most stations, relative to those of deeper events. This observation can be explained by a low-Q surficial zone. For stations of the network situated on alluvium, this low-Q layer has a maximum thickness of about 3 km and maximum P- and S-wave Q values of 30 to 50.

Stable isotope evidence for hydrologic conditions during regional metamorphism in the Panamint Mountains, California

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

Bergfeld, D.; Nabelek, P.I.; Labotka, T.C.

1992-01-01

The Kingston Peak Formation forms part of the Panamint Mountains, California, metamorphic core-complex. Peak tremolite-grade metamorphism as exhibited in Wildrose Canyon occurred in the Jurassic; a retrograde thermal event may have occurred in the Cretaceous. The formation consists dominantly of interbedded siliceous limestones and graphitic calcareous schists. Stable isotopic analysis shows two distinct groups of data. delta O-18 values of calcite from the limestones range between 15.3 and 17.3[per thousand], probably reflecting their original Proterozoic depositional values. Likewise the delta C-13 values are also unshifted, ranging from +1% to +3.8%o. In contrast, delta O-18 values of calcite from the schistsmore » are for the most part > 20[per thousand]. These high values could reflect the original depostional conditions; however, they may be due to equilibration with silicate minerals which range from 14.9 to 17.9[per thousand]. Overall, the combined oxygen and carbon isotopic data indicate that most isotopic changes can be explained by closed-system equilibration. Only a limited amount of interaction with externally-derived fluids during metamorphism is evident in the isotopic data. The interaction may have been confined to vicinities of faults and fractures which are common in Wildrose Canyon.« less

Influence of Dense Inert Additives (W and Pb) on Detonation Conditions and Regime of Condensed Explosives

NASA Astrophysics Data System (ADS)

Imkhovik, Nikolay A.

2010-10-01

Results of experimental and theoretical studies of the unusual detonation properties of mixtures of high explosives (HEs) with high-density inert additives W and Pb were analyzed and systematized. Typical examples of the nonideal detonation of composite explosives for which the measured detonation pressure is substantially lower and the detonation velocity is higher than the values calculated within the framework of the hydrodynamic model, with the specific heat ratio for the detonation products of ∼6-8, are presented. Mechanisms of formation of anomalous pressure and mass velocity profiles, which explain the correlation between the Chapman-Jouguet pressure for HE-W and HE-Pb mixtures, the velocity of the free surface of duralumin target, and the depth of the dent imprinted in steel witness plates, are described.

Umklapp scattering as the origin of T -linear resistivity in the normal state of high- T c cuprate superconductors

DOE PAGES

Rice, T. Maurice; Robinson, Neil J.; Tsvelik, Alexei M.

2017-12-11

Here, the high-temperature normal state of the unconventional cuprate superconductors has resistivity linear in temperature T, which persists to values well beyond the Mott-Ioffe-Regel upper bound. At low temperatures, within the pseudogap phase, the resistivity is instead quadratic in T, as would be expected from Fermi liquid theory. Developing an understanding of these normal phases of the cuprates is crucial to explain the unconventional superconductivity. We present a simple explanation for this behavior, in terms of the umklapp scattering of electrons. This fits within the general picture emerging from functional renormalization group calculations that spurred the Yang-Rice-Zhang ansatz: Umklapp scatteringmore » is at the heart of the behavior in the normal phase.« less

Electron scattering in large water clusters from photoelectron imaging with high harmonic radiation.

PubMed

Gartmann, Thomas E; Hartweg, Sebastian; Ban, Loren; Chasovskikh, Egor; Yoder, Bruce L; Signorell, Ruth

2018-06-06

Low-energy electron scattering in water clusters (H2O)n with average cluster sizes of n < 700 is investigated by angle-resolved photoelectron spectroscopy using high harmonic radiation at photon energies of 14.0, 20.3, and 26.5 eV for ionization from the three outermost valence orbitals. The measurements probe the evolution of the photoelectron anisotropy parameter β as a function of cluster size. A remarkably steep decrease of β with increasing cluster size is observed, which for the largest clusters reaches liquid bulk values. Detailed electron scattering calculations reveal that neither gas nor condensed phase scattering can explain the cluster data. Qualitative agreement between experiment and simulations is obtained with scattering calculations that treat cluster scattering as an intermediate case between gas and condensed phase scattering.

Hedonic Changes in Food Choices Following Roux-en-Y Gastric Bypass.

PubMed

Hansen, Thea Toft; Jakobsen, Tine Anette; Nielsen, Mette Søndergaard; Sjödin, Anders; Le Roux, Carel W; Schmidt, Julie Berg

2016-08-01

It has been suggested that a shift in food choices leading to a diet with a lower energy density plays an important role in successful weight loss after Roux-en-Y gastric bypass (RYGB) surgery. A decreased hedonic drive to consume highly palatable foods may explain these changes in eating behavior. Here, we review the literature examining postoperative changes in mechanisms contributing to hedonic drive (food preferences, reinforcing value of food, dopamine signaling, and activity reward-related brain regions). The majority of studies reviewed support that RYGB decrease the hedonic drive to consume highly palatable foods. Still, in order to fully understand the complexity of these changes, we need studies combining sociological and psychological approaches with objective measures of actual food choices examining different measures of hedonic drive.

Early subtropical forest growth is driven by community mean trait values and functional diversity rather than the abiotic environment.

PubMed

Kröber, Wenzel; Li, Ying; Härdtle, Werner; Ma, Keping; Schmid, Bernhard; Schmidt, Karsten; Scholten, Thomas; Seidler, Gunnar; von Oheimb, Goddert; Welk, Erik; Wirth, Christian; Bruelheide, Helge

2015-09-01

While functional diversity (FD) has been shown to be positively related to a number of ecosystem functions including biomass production, it may have a much less pronounced effect than that of environmental factors or species-specific properties. Leaf and wood traits can be considered particularly relevant to tree growth, as they reflect a trade-off between resources invested into growth and persistence. Our study focussed on the degree to which early forest growth was driven by FD, the environment (11 variables characterizing abiotic habitat conditions), and community-weighted mean (CWM) values of species traits in the context of a large-scale tree diversity experiment (BEF-China). Growth rates of trees with respect to crown diameter were aggregated across 231 plots (hosting between one and 23 tree species) and related to environmental variables, FD, and CWM, the latter two of which were based on 41 plant functional traits. The effects of each of the three predictor groups were analyzed separately by mixed model optimization and jointly by variance partitioning. Numerous single traits predicted plot-level tree growth, both in the models based on CWMs and FD, but none of the environmental variables was able to predict tree growth. In the best models, environment and FD explained only 4 and 31% of variation in crown growth rates, respectively, while CWM trait values explained 42%. In total, the best models accounted for 51% of crown growth. The marginal role of the selected environmental variables was unexpected, given the high topographic heterogeneity and large size of the experiment, as was the significant impact of FD, demonstrating that positive diversity effects already occur during the early stages in tree plantations.

Breslow Density Is a Novel Prognostic Feature That Adds Value to Melanoma Staging.

PubMed

Saldanha, Gerald; Yarrow, Jeremy; Pancholi, Jay; Flatman, Katarina; Teo, Kah Wee; Elsheik, Somaia; Harrison, Rebecca; O'Riordan, Marie; Bamford, Mark

2018-06-01

Histomorphologic prognostic biomarkers that can be measured using only an hematoxylin and eosin stain are very attractive because they are simple and cheap. We conceived an entirely novel biomarker of this type, the Breslow density (BD), which measures invasive melanoma cell density at the site where Breslow thickness (BT) is measured. This study assessed BD's prognostic value. In this study, BD was measured in 1329 melanoma patients. Measurement accuracy and precision was assessed using intraclass correlation coefficient (ICC). Survival was assessed with a primary end-point of melanoma-specific survival (MSS) and also overall survival and metastasis-free survival. We found that BD measurement was accurate compared with gold standard image analysis (ICC, 0.84). Precision was excellent for 3 observers with different experience (ICC, 0.93) and for an observer using only written instructions (ICC, 0.93). BD was a highly significant predictor in multivariable analysis for overall survival, MSS, and metastasis-free survival (each, P<0.001) and it explained MSS better than BT, but BT and BD together had best explanatory capability. A BD cut point of ≥65% was trained in 970 melanomas and validated in 359. This cut point showed promise as a novel way to upstage melanoma from T stage "a" to "b." BD was combined with BT to create a targeted burden score. This was a validated as an adjunct to American Joint Committee on Cancer stage. In summary, BD can be measured accurately and precisely. It demonstrated independent prognostic value and explained MSS better than BT alone. Notably, we demonstrated ways that BD could be used with American Joint Committee on Cancer version 8 staging.

Specific ultra-violet absorbance as an indicator measurement of merucry sources in an Adirondack River basin

USGS Publications Warehouse

Burns, Douglas A.; Aiken, George R.; Bradley, Paul M.; Journey, Celeste A.; Schelker, Jakob

2013-01-01

The Adirondack region of New York has been identified as a hot spot where high methylmercury concentrations are found in surface waters and biota, yet mercury (Hg) concentrations vary widely in this region. We collected stream and groundwater samples for Hg and organic carbon analyses across the upper Hudson River, a 493 km2 basin in the central Adirondacks to evaluate and model the sources of variation in filtered total Hg (FTHg) concentrations. Variability in FTHg concentrations during the growing seasons (May-Oct) of 2007-2009 in Fishing Brook, a 66-km2 sub-basin, was better explained by specific ultra-violet absorbance at 254 nm (SUVA254), a measure of organic carbon aromaticity, than by dissolved organic carbon (DOC) concentrations, a commonly used Hg indicator. SUVA254 was a stronger predictor of FTHg concentrations during the growing season than during the dormant season. Multiple linear regression models that included SUVA254 values and DOC concentrations could explain 75 % of the variation in FTHg concentrations on an annual basis and 84 % during the growing season. A multiple linear regression landscape modeling approach applied to 27 synoptic sites across the upper Hudson basin found that higher SUVA254 values are associated with gentler slopes, and greater riparian area, and lower SUVA254 values are associated with an increasing influence of open water. We hypothesize that the strong Hg?SUVA254 relation in this basin reflects distinct patterns of FTHg and SUVA254 that are characteristic of source areas that control the mobilization of Hg to surface waters, and that the seasonal influence of these source areas varies in this heterogeneous basin landscape.

Relationship between Organizational Culture and the Use of Psychotropic Medicines in Nursing Homes: A Systematic Integrative Review.

PubMed

Sawan, Mouna; Jeon, Yun-Hee; Chen, Timothy F

2018-03-01

Psychotropic medicines are commonly used in nursing homes, despite marginal clinical benefits and association with harm in the elderly. Organizational culture is proposed as a factor explaining the high-level use of psychotropic medicines. Schein describes three levels of culture: artifacts, espoused values, and basic assumptions. This integrative review aimed to investigate the facets and role of organizational culture in the use of psychotropic medicines in nursing homes. Five databases were searched for qualitative, quantitative, and mixed method empirical studies up to 13 February 2017. Articles were included if they examined an aspect of organizational culture according to Schein's theory and the use of psychotropic medicines in nursing homes for the management of behavioral and sleep disturbances in residents. Article screening and data extraction were performed independently by one reviewer and checked by the research team. The integrative review method, an approach similar to the method of constant comparison analysis was utilized for data analysis. Twenty-four studies met the inclusion criteria: 13 used quantitative methods, 9 used qualitative methods, 1 was quasi-qualitative, and 1 used mixed methods. Included studies were found to only address two aspects of organizational culture in relation to the use of psychotropic medicines: artifacts and espoused values. No studies addressed the basic assumptions, the unsaid taken-for-granted beliefs, which provide explanations for in/consistencies between the ideal use of psychotropic medicines and the actual use of psychotropic medicines. Previous studies suggest that organizational culture influences the use of psychotropic medicines in nursing homes; however, what is known is descriptive of culture only at the surface level, that is the artifacts and espoused values. Hence, future research that explains the impact of the basic assumptions of culture on the use of psychotropic medicines is important.

Early subtropical forest growth is driven by community mean trait values and functional diversity rather than the abiotic environment

PubMed Central

Kröber, Wenzel; Li, Ying; Härdtle, Werner; Ma, Keping; Schmid, Bernhard; Schmidt, Karsten; Scholten, Thomas; Seidler, Gunnar; von Oheimb, Goddert; Welk, Erik; Wirth, Christian; Bruelheide, Helge

2015-01-01

While functional diversity (FD) has been shown to be positively related to a number of ecosystem functions including biomass production, it may have a much less pronounced effect than that of environmental factors or species-specific properties. Leaf and wood traits can be considered particularly relevant to tree growth, as they reflect a trade-off between resources invested into growth and persistence. Our study focussed on the degree to which early forest growth was driven by FD, the environment (11 variables characterizing abiotic habitat conditions), and community-weighted mean (CWM) values of species traits in the context of a large-scale tree diversity experiment (BEF-China). Growth rates of trees with respect to crown diameter were aggregated across 231 plots (hosting between one and 23 tree species) and related to environmental variables, FD, and CWM, the latter two of which were based on 41 plant functional traits. The effects of each of the three predictor groups were analyzed separately by mixed model optimization and jointly by variance partitioning. Numerous single traits predicted plot-level tree growth, both in the models based on CWMs and FD, but none of the environmental variables was able to predict tree growth. In the best models, environment and FD explained only 4 and 31% of variation in crown growth rates, respectively, while CWM trait values explained 42%. In total, the best models accounted for 51% of crown growth. The marginal role of the selected environmental variables was unexpected, given the high topographic heterogeneity and large size of the experiment, as was the significant impact of FD, demonstrating that positive diversity effects already occur during the early stages in tree plantations. PMID:26380685

Large thermoelectric power factor from crystal symmetry-protected non-bonding orbital in half-Heuslers.

PubMed

Zhou, Jiawei; Zhu, Hangtian; Liu, Te-Huan; Song, Qichen; He, Ran; Mao, Jun; Liu, Zihang; Ren, Wuyang; Liao, Bolin; Singh, David J; Ren, Zhifeng; Chen, Gang

2018-04-30

Modern society relies on high charge mobility for efficient energy production and fast information technologies. The power factor of a material-the combination of electrical conductivity and Seebeck coefficient-measures its ability to extract electrical power from temperature differences. Recent advancements in thermoelectric materials have achieved enhanced Seebeck coefficient by manipulating the electronic band structure. However, this approach generally applies at relatively low conductivities, preventing the realization of exceptionally high-power factors. In contrast, half-Heusler semiconductors have been shown to break through that barrier in a way that could not be explained. Here, we show that symmetry-protected orbital interactions can steer electron-acoustic phonon interactions towards high mobility. This high-mobility regime enables large power factors in half-Heuslers, well above the maximum measured values. We anticipate that our understanding will spark new routes to search for better thermoelectric materials, and to discover high electron mobility semiconductors for electronic and photonic applications.

Environmental Risk Assessment: Spatial Analysis of Chemical Hazards and Risks in South Korea

NASA Astrophysics Data System (ADS)

Yu, H.; Heo, S.; Kim, M.; Lee, W. K.; Jong-Ryeul, S.

2017-12-01

This study identified chemical hazard and risk levels in Korea by analyzing the spatial distribution of chemical factories and accidents. The number of chemical factories and accidents in 5-km2 grids were used as the attribute value for spatial analysis. First, semi-variograms were conducted to examine spatial distribution patterns and to identify spatial autocorrelation of chemical factories and accidents. Semi-variograms explained that the spatial distribution of chemical factories and accidents were spatially autocorrelated. Second, the results of the semi-variograms were used in Ordinary Kriging to estimate chemical hazard and risk level. The level values were extracted from the Ordinary Kriging result and their spatial similarity was examined by juxtaposing the two values with respect to their location. Six peaks were identified in both the hazard and risk estimation result, and the peaks correlated with major cities in Korea. Third, the estimated hazard and risk levels were classified with geometrical interval and could be classified into four quadrants: Low Hazard and Low Risk (LHLR), Low Hazard and High Risk (LHHR), High Hazard and Low Risk (HHLR), and High Hazard and High Risk (HHHR). The 4 groups identified different chemical safety management issues in Korea; relatively safe LHLR group, many chemical reseller factories were found in HHLR group, chemical transportation accidents were in the LHHR group, and an abundance of factories and accidents were in the HHHR group. Each quadrant represented different safety management obstacles in Korea, and studying spatial differences can support the establishment of an efficient risk management plan.

Critical Factors Explaining the Leadership Performance of High-Performing Principals

ERIC Educational Resources Information Center

Hutton, Disraeli M.

2018-01-01

The study explored critical factors that explain leadership performance of high-performing principals and examined the relationship between these factors based on the ratings of school constituents in the public school system. The principal component analysis with the use of Varimax Rotation revealed that four components explain 51.1% of the…

Nutrient digestibility and energy value of sheep rations differing in protein level, main protein source and non-forage fibre source.

PubMed

Milis, Ch; Liamadis, D

2008-02-01

Two in vivo digestion trials were conducted to evaluate the effects of diet's crude protein (CP) level, N degradability, and non-forage fibre source (NFFS) on nutrient digestibility and energy value of sheep rations. In each trial, rams were fed four isocaloric and isofibrous rations, differing in main protein and/or NFFS source. At the first trial, mean CP/metabolizable energy (ME) ratio of the diets was 17 g/MJ ME and at the second trial, 13 g/MJ ME. At both trials, the first ration contained cotton seed cake (CSC) and wheat bran (WB), the second CSC and corn gluten feed (CGF), the third corn gluten meal (CGM) and WB and the fourth CGM and CGF. Data of both trials were analysed in common as 2 x 2 x 2 factorial experimental design. Low N degradability (CGM) had positive effect on CP, neutral detergent fibre (NDF) and acid detergent fibre (ADF) digestibility of the ration. Those results suggest that an increase in rumen undegradable protein (RUP) content does not negatively affect nutrient digestibility of sheep rations. Corn gluten feed significantly elevated crude fibre (CF) digestibility, in comparison with WB. Rations having high CP/ME ratio had higher digestibility of CP in comparison with those having low CP/ME ratio; the opposite was true for ether extract, CF, NDF and ADF digestibilities. CP level x N degradability interaction negatively affected energy value of the rations that had high CP level and high N degradability. Former suggest that when CP content is high then N degradability should be low otherwise ration's ME is negatively affected. CP digestibility and coefficient q of the rations containing WB and having high N degradability (N degradability x NFFS interaction) were the lowest suggesting that the combination of CSC and WB negatively affected CP digestibility and energy value of the ration. This could be explained by a reduced microbial CP synthesis, or lower RUP digestibility or both.

Measurement of math beliefs and their associations with math behaviors in college students.

PubMed

Hendy, Helen M; Schorschinsky, Nancy; Wade, Barbara

2014-12-01

Our purpose in the present study was to expand understanding of math beliefs in college students by developing 3 new psychometrically tested scales as guided by expectancy-value theory, self-efficacy theory, and health belief model. Additionally, we identified which math beliefs (and which theory) best explained variance in math behaviors and performance by college students and which students were most likely to have problematic math beliefs. Study participants included 368 college math students who completed questionnaires to report math behaviors (attending class, doing homework, reading textbooks, asking for help) and used a 5-point rating scale to indicate a variety of math beliefs. For a subset of 84 students, math professors provided final math grades. Factor analyses produced a 10-item Math Value Scale with 2 subscales (Class Devaluation, No Future Value), a 7-item single-dimension Math Confidence Scale, and an 11-item Math Barriers Scale with 2 subscales (Math Anxiety, Discouraging Words). Hierarchical multiple regression revealed that high levels of the newly discovered class devaluation belief (guided by expectancy-value theory) were most consistently associated with poor math behaviors in college students, with high math anxiety (guided by health belief model) and low math confidence (guided by self-efficacy theory) also found to be significant. Analyses of covariance revealed that younger and male students were at increased risk for class devaluation and older students were at increased risk for poor math confidence. (c) 2014 APA, all rights reserved.

Values of Deploying a Compact Polarimetric Radar to Monitor Extreme Precipitation in a Mountainous Area: Mineral County, Colorado

NASA Astrophysics Data System (ADS)

Cheong, B. L.; Kirstetter, P. E.; Yu, T. Y.; Busto, J.; Speeze, T.; Dennis, J.

2015-12-01

Precipitation in mountainous regions can trigger flash floods and landslides especially in areas affected by wildfire. Because of the small space-time scales required for observation, they remain poorly observed. A light-weighted X-band polarimetric radar can rapidly respond to the situation and provide continuous rainfall information with high resolution for flood forecast and emergency management. A preliminary assessment of added values to the operational practice in Mineral county, Colorado was performed in Fall 2014 and Summer 2015 with a transportable polarimetric radar deployed at the Lobo Overlook. This region is one of the numerous areas in the Rocky Mountains where the WSR-88D network does not provide sufficient weather coverage due to blockages, and the limitations have impeded forecasters and local emergency managers from making accurate predictions and issuing weather warnings. High resolution observations were collected to document the precipitation characteristics and demonstrate the added values of deploying a small weather radar in such context. The analysis of the detailed vertical structure of precipitation explain the decreased signal sampled by the operational radars. The specific microphysics analyzed though polarimetry suggest that the operational Z-R relationships may not be appropriate to monitor severe weather over this wildfire affected region. Collaboration with the local emergency managers and the National Weather Service shows the critical value of deploying mobile, polarimetric and unmanned radars in complex terrain. Several selected cases are provided in this paper for illustration.

Reconstructing recent volcanic histories from high-resolution AUV sidescan sonar imagery

NASA Astrophysics Data System (ADS)

Yeo, I. A.

2016-12-01

Detecting high-resolution differences in age between young basaltic lava flows on the seafloor is notoriously difficult. However, using sediment thickness as a proxy for age it is possible to derive information on spatial extents, surface morphologies and lava flow age simultaneously using high-resolution sidescan sonar imagery. Ground truthing of this new method on cruise POS502 (July 2016) using photogrammetry from ROV cameras has provided constraints on the method allowing the detailed morphological changes and sediment cover thicknesses to be calibrated to produce reliable, quantitative ages for individual flow units. Sediment thickness is shown to be the primary controlling factor in backscatter intensity in most cases, although sediment redistribution by different flow morphologies can also affect the recorded reflection amplitudes. Seafloor lava flows were found to be very morphologically complicated on small scales, which may explain their relative unimportance when amplitude values are averaged over several tens of meters.

Observation of frequency cutoff for self-excited dust acoustic waves

NASA Astrophysics Data System (ADS)

Nosenko, V.; Zhdanov, S. K.; Morfill, G. E.; Kim, S.-H.; Heinrich, J.; Merlino, R. L.

2009-11-01

Complex (dusty) plasmas consist of fine solid particles suspended in a weakly ionized gas. Complex plasmas are excellent model systems to study wave phenomena down to the level of individual ``atoms''. Spontaneously excited dust acoustic waves were observed with high temporal resolution in a suspension of micron-size kaolin particles in a dc discharge in argon. Wave activity was found at frequencies as high as 400 Hz. At high wave numbers, the wave dispersion relation was acoustic-like (frequency proportional to wave number). At low wave numbers, the wave frequency did not tend to zero, but reached a cutoff frequency fc instead. The value of fc declined with distance from the anode. We propose a simple model that explains the observed cutoff by particle confinement in plasma. The existence of a cutoff frequency is very important for the propagation of waves: the waves excited above fc are propagating, and those below fc are evanescent.

Refractory materials for high-temperature thermoelectric energy conversion

NASA Technical Reports Server (NTRS)

Wood, C.; Emin, D.

1983-01-01

Theoretical work of two decades ago adequately explained the transport behavior and effectively guided the development of thermoelectric materials of high conversion efficiencies of conventional semiconductors (e.g., SiGe alloys). The more significant contributions involved the estimation of optimum doping concentrations, the reduction of thermal conductivity by solid solution doping and the development of a variety of materials with ZT approx. 1 in the temperature range 300 K to 1200 K. ZT approx. 1 is not a theoretical limitation although, experimentally, values in excess of one were not achieved. Work has continued with emphasis on higher temperature energy conversion. A number of promising materials have been discovered in which it appears that ZT 1 is realizable. These materials are divided into two classes: (1) the rare-earth chalcogenides which behave as itinerant highly-degenerate n-type semiconductors at room-temperature, and (2) the boron-rich borides, which exhibit p-type small-polaronic hopping conductivity.

Air Entrapment for Liquid Drops Impacting a Solid Substrate

NASA Astrophysics Data System (ADS)

Liu, Yuan; Tan, Peng; Xu, Lei

2012-11-01

Using high-speed photography coupled with optical interference, we experimentally study the air entrapment during a liquid drop impacting a solid substrate. We observe the formation of a compressed air film before the liquid touches the substrate, with internal pressure considerably higher than the atmospheric value. The degree of compression highly depends on the impact velocity, as explained by balancing the liquid deceleration with the large pressure of compressed air. After contact, the air film expands vertically at the edge, reducing its pressure within a few tens of microseconds and producing a thick rim on the perimeter. This thick-rimmed air film subsequently contracts into an air bubble, governed by the complex interaction between surface tension, inertia and viscous drag. Such a process is universally observed for impacts above a few centimeters high. Hong Kong GRF grant CUHK404211 and direct grant 2060418.

A possible high-mobility signal in bulk MoTe2: Temperature independent weak phonon decay

NASA Astrophysics Data System (ADS)

Li, Titao; Zhang, Zhaojun; Zheng, Wei; Lv, Yangyang; Huang, Feng

2016-11-01

Layered transition metal dichalcogenides (TMDs) have attracted great attention due to their non-zero bandgap for potential application in high carrier mobility devices. Recent studies demonstrate that the carrier mobility of MoTe2 would decrease by orders of magnitude when used for few-layer transistors. As phonon scattering has a significant influence on carrier mobility of layered material, here, we first reported temperature-dependent Raman spectra of bulk 2H-MoTe2 from 80 to 300 K and discovered that the phonon lifetime of both E12g and A1g vibration modes are independent with temperature. These results were explained by the weak phonon decay in MoTe2. Our results imply the existence of a carrier mobility higher than the theoretical value in intrinsic bulk 2H-MoTe2 and the feasibility to obtain MoTe2-based transistors with sufficiently high carrier mobility.

Silurian carbonate high-energy deposits of potential tsunami origin: Distinguishing lateral redeposition and time averaging using carbon isotope chemostratigraphy

NASA Astrophysics Data System (ADS)

Jarochowska, Emilia; Munnecke, Axel

2015-01-01

Stable carbon isotope curves are used as a precise stratigraphic tool in the Paleozoic, even though they are commonly based on shallow-water carbonate record, characterized by low stratigraphic completeness. Identification of episodes of large-scale redeposition and erosion may improve δ13Ccarb-based correlations. Here, a series of at least three episodes of high-energy onshore redeposition are described from the Makarivka Member (new unit) of the Ustya Formation from the Homerian (middle Silurian) of Podolia, Ukraine. The Makarivka Member is emplaced within a tidal flat succession. Its most prominent part is divided into a lower polymictic conglomerate of sand- to boulder-sized clasts representing a range of subtidal facies, and an upper heterolithic unit composed of grainstone and mudstone laminae. The aim of the study is to identify the mechanism of deposition of the allochthonous conglomeratic material in this Member. Based on analogies with recent tsunami deposits, the conglomerate is interpreted to reflect the strongest landward-directed current in the tsunami run-up phase, and the heterolith - alternating high-density landward currents, stagnant intervals allowing mud and land-derived debris to settle, and backwash flows. The tsunamite was deposited during an interval of decreasing isotopic values of the Mulde excursion, a global δ13C excursion reaching + 5.2‰ in the studied sections. Clast redeposition in an interval characterized by rapidly changing δ13Ccarb offers the opportunity to evaluate the degree of temporal and spatial averaging caused by the tsunami. The clasts in the polymictic conglomerate show scattered δ13Ccarb values (- 0.3‰ to + 2.1‰) compared to homogenous (1.3‰ to 1.6‰) values in the matrix. The presence of clasts characterized by low δ13Ccarb values is explained by their decrease with bathymetry rather than erosion of pre-excursion strata, whereas high values characterize material entrained from the sea-floor and strata directly underlying the tsunamite. Close (1.3‰ and 1.5‰) average δ13Ccarb values suggest that the matrix of the conglomerate is potentially a product of clast grinding.

Explaining outcome type interactions with frame: aspiration level and the value function.

PubMed

Bloomfield, Amber N

2008-06-01

Research on framing effects has revealed cases where the type of outcome at risk (e.g., human lives vs. animal lives) affects the magnitude of the framing effect. Some authors have appealed to the shape of the value function as predicting when framing effects will occur: The more valuable the outcome type, the more nonlinear its value function, and the larger the resulting framing effect (Levin & Chapman, 1990). However, having a more or less nonlinear value function cannot explain situations in which participants strongly prefer the same option in both frames. Another factor that may be at work in these types of outcome effects is an aspiration level (AL; Lopes, 1987; Schneider, 1992), which determines how acceptable the options are and combines (or competes) with the risk attitude encouraged by frame. The results described here indicate that differences in the shape of the value function between outcome types are evident but are inconsistent between framed losses and gains, though nonlinearity in the value function can be increased with a manipulation that also encourages framing effects. The results also demonstrate that an AL can lead to the same predominant risk preference in the positive and negative frame. These findings indicate that the shape of the value function and the AL each play a role in outcome type interactions with frame, and in some cases, a combination of the two factors may be at work.

The relative value of growth.

PubMed

Mass, Nathaniel J

2005-04-01

Most executives would say that adding a point of growth and gaining a point of operating-profit margin contribute about equally to shareholder value. Margin improvements hit the bottom line immediately, while growth compounds value over time. But the reality is that the two are rarely equivalent. Growth often is far more valuable than managers think. For some companies, convincing the market that they can grow by just one additional percentage point can be worth six, seven, or even ten points of margin improvement. This article presents a new strategic metric, called the relative value of growth (RVG), which gives managers a clear picture of how growth projects and margin improvement initiatives affect shareholder value. Using basic balance sheet and income sheet data, managers can determine their companies' RVGs, as well as those of their competitors. Calculating RVGs gives managers insights into which corporate strategies are working to deliver value and whether their companies are pulling the most powerful value-creation levers. The author examines a number of well-known companies and explains what their RVG numbers say about their strategies. He reviews the unspoken assumption that growth and profits are incompatible over the long term and shows that a fair number of companies are effective at delivering both. Finally, he explains how managers can use the RVG framework to help them define strategies that balance growth and profitability at both the corporate and business unit levels.

Place-Building Theory: A Framework for Assessing and Advancing Community Engagement in Higher Education

ERIC Educational Resources Information Center

Kimball, Michael J.; Thomas, David F.

2012-01-01

Place-building theory, originally developed to assess corporate social responsibility, explains to what degree an organization values and invests in its geographical and social location. Different lines of inquiry--descriptive, evaluative, and prescriptive--elucidate how the organization values place, which in turn suggests its type, its…

The Business Values of American Newspapers: The Nineteenth-Century Watershed.

ERIC Educational Resources Information Center

Nord, David Paul

The rejection of the "Great Forces" and "Great Man" theories of newspaper history allows a middle-range view that seeks to discover the uniqueness of the newspaper business and to explain how that uniqueness shaped the business values of the editors and proprietors. An examination of three Chicago, Illinois, newspapers--the…

Value-Added Models: What the Experts Say

ERIC Educational Resources Information Center

Amrein-Beardsley, Audrey; Pivovarova, Margarita; Geiger, Tray J.

2016-01-01

Being an expert involves explaining how things are supposed to work, and, perhaps more important, why things might not work as supposed. In this study, researchers surveyed scholars with expertise in value-added models (VAMs) to solicit their opinions about the uses and potential of VAMs for teacher-level accountability purposes (for example, in…

76 FR 697 - United States-Oman Free Trade Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-06

... OFTA sets forth the rules for determining whether an imported good qualifies as an originating good of... value-content, i.e., at least 35 percent of the good's appraised value must be attributed to the cost or....2 explains that the term ``new or different article of commerce'' means a good that has been...

The Contradiction in the "Prevent Duty": Democracy vs "British Values"

ERIC Educational Resources Information Center

Wolton, Suke

2017-01-01

The duty to monitor "the failure to uphold British Values" in the "Prevent" strategy, introduced in the Counter-Terrorism and Security Act 2015, is itself an attack on British democracy. This article explains the contradictory nature of the "Prevent Duty." First, the current state of democracy in Britain is examined…

Gender and Choosing a STEM Major in College: Femininity, Masculinity, Chilly Climate, and Occupational Values

ERIC Educational Resources Information Center

Simon, Richard M.; Wagner, Ashley; Killion, Brooke

2017-01-01

Masculinity and femininity have played a substantial role in how social scientists explain the gender gap in science, technology, engineering, and mathematics (STEM) careers. The masculine culture of science is thought to be inconsistent with occupational values associated with feminine personalities, and to create a discriminatory academic…

Combining-Ability Determinations for Incomplete Mating Designs

Treesearch

E.B. Snyder

1975-01-01

It is shown how general combining ability values (GCA's) from cross-, open-, and self-pollinated progeny can be derived in a single analysis. Breeding values are employed to facilitate explaining genetic models of the expected family means and the derivation of the GCA's. A FORTRAN computer program also includes computation of specific combining ability...

Values in Political Science Students' Contextualizations of Nationalism

ERIC Educational Resources Information Center

Murstedt, Linda; Trostek, Jonas R.; Scheja, Max

2015-01-01

Recent research on conceptual change has argued that it is insufficient to assume that prior knowledge is the only aspect relevant in order to explain the conceptual change process. In addition, "warm constructs" such as emotions, epistemological beliefs, and values have been proposed to play a determinative role. In this study, we aim…

Applying Rasch model analysis in the development of the cantonese tone identification test (CANTIT).

PubMed

Lee, Kathy Y S; Lam, Joffee H S; Chan, Kit T Y; van Hasselt, Charles Andrew; Tong, Michael C F

2017-01-01

Applying Rasch analysis to evaluate the internal structure of a lexical tone perception test known as the Cantonese Tone Identification Test (CANTIT). A 75-item pool (CANTIT-75) with pictures and sound tracks was developed. Respondents were required to make a four-alternative forced choice on each item. A short version of 30 items (CANTIT-30) was developed based on fit statistics, difficulty estimates, and content evaluation. Internal structure was evaluated by fit statistics and Rasch Factor Analysis (RFA). 200 children with normal hearing and 141 children with hearing impairment were recruited. For CANTIT-75, all infit and 97% of outfit values were < 2.0. RFA revealed 40.1% of total variance was explained by the Rasch measure. The first residual component explained 2.5% of total variance in an eigenvalue of 3.1. For CANTIT-30, all infit and outfit values were < 2.0. The Rasch measure explained 38.8% of total variance, the first residual component explained 3.9% of total variance in an eigenvalue of 1.9. The Rasch model provides excellent guidance for the development of short forms. Both CANTIT-75 and CANTIT-30 possess satisfactory internal structure as a construct validity evidence in measuring the lexical tone identification ability of the Cantonese speakers.

Electrochemical investigation of lead-calcium alloys in sulphuric acid

NASA Astrophysics Data System (ADS)

Bass, K.; Ellis, S. R.; Johnson, M.; Hampson, N. A.

The hydrogen evolution reaction from, and the cycle life (Pb /ar PbSO 4) of, a series of lead-calcium alloys (0 - 0.2 wt.% Ca) in sulphuric acid hav The exchange current density and Tafel slope for the H.R.E. increase with Ca content up to 0.05 wt.% then decrease to a value approaching that of pure The observed results are explained by: (i) preferential adsorption of calcium ions at the electrode surface; (ii) incorporation of Ca, to form a supersaturated solution, with alloys containing < 0.075 wt.% Ca; (iii) formation of an insoluble, non-conducting layer of calcium sulphate on the high content alloy.

How excluding some benefits from value assessment of new drugs impacts innovation.

PubMed

Cook, Joseph P; Golec, Joseph

2017-12-01

Payers often assess the benefits of new drugs relative to costs for reimbursement purposes, but they frequently exclude some drugs' option-related benefits, reducing their reimbursement chances, and making them less attractive R&D investments. We develop and test a real options model of R&D investment that shows that excluding option-related benefits heightens drug developers' incentives to avoid high-risk (volatile) R&D investments and instead encourages them to focus on "safer" (positively skewed) investments. Our model and empirical results could partly explain the decline in the number of risky new molecular entities. Copyright © 2017 John Wiley & Sons, Ltd.

Design-Optimization Of Cylindrical, Layered Composite Structures Using Efficient Laminate Parameterization

NASA Astrophysics Data System (ADS)

Monicke, A.; Katajisto, H.; Leroy, M.; Petermann, N.; Kere, P.; Perillo, M.

2012-07-01

For many years, layered composites have proven essential for the successful design of high-performance space structures, such as launchers or satellites. A generic cylindrical composite structure for a launcher application was optimized with respect to objectives and constraints typical for space applications. The studies included the structural stability, laminate load response and failure analyses. Several types of cylinders (with and without stiffeners) were considered and optimized using different lay-up parameterizations. Results for the best designs are presented and discussed. The simulation tools, ESAComp [1] and modeFRONTIER [2], employed in the optimization loop are elucidated and their value for the optimization process is explained.

Viewpoints of high migratory tuna species ecology. Comment on ;Physics of metabolic organization; by M. Jusup et al.

NASA Astrophysics Data System (ADS)

Kitagawa, Takashi; Aoki, Yoshinori

2017-03-01

When discussing the evolution of fish migration, it is necessary to consider the total benefit fish acquire over their entire life history. With diadromous migration, for instance, some fish species migrate from freshwater and feed in the ocean (anadromous species), and others migrate from the ocean and feed in freshwater (catadromous). These contrasting directions of migration can largely be explained by the relative availability of food resources in ocean and freshwater habitats [1]. However, there are few examples that measure or quantify total energy as a concrete value that a single fish acquires through migration.

Surface photovoltage in exciton absorption range in CdS

NASA Technical Reports Server (NTRS)

Morawski, A.; Banisch, R.; Lagowski, J.

1977-01-01

The high resolution, intrinsic spectra of surface photovoltage are reported for semiconducting n-type CdS single crystals. At reduced temperatures (120-160 K) the spectra exhibit three sharp maxima due to A, B and C free exciton transitions. Energy positions of these lines and valence band parameters (spin-orbit and crystal field splittings) estimated from surface photovoltage are in good agreement with values obtained by other methods. The excitonic transitions are very sensitive to surface treatment, i.e. polishing, etching, background illumination and surface doping. The mechanism of direct interaction of free excitons with surface states is proposed to explain exciton lines in surface photovoltage.

Multidimensional scaling for evolutionary algorithms--visualization of the path through search space and solution space using Sammon mapping.

PubMed

Pohlheim, Hartmut

2006-01-01

Multidimensional scaling as a technique for the presentation of high-dimensional data with standard visualization techniques is presented. The technique used is often known as Sammon mapping. We explain the mathematical foundations of multidimensional scaling and its robust calculation. We also demonstrate the use of this technique in the area of evolutionary algorithms. First, we present the visualization of the path through the search space of the best individuals during an optimization run. We then apply multidimensional scaling to the comparison of multiple runs regarding the variables of individuals and multi-criteria objective values (path through the solution space).

Carbon and oxygen stable isotopes in large herbivore tooth enamel illustrate a mid-Miocene precipitation increase in the interior Pacific Northwest

NASA Astrophysics Data System (ADS)

Drewicz, A.; Kohn, M. J.

2017-12-01

The mid-Miocene Climatic Optimum (MMCO; 13.75-16.9 Ma), represents the warmest period in Earth's history during the last 35 Ma, and is distinguished by low ice volume and high ocean water temperatures. The MMCO has been associated with high atmospheric CO2 (pCO2) similar to levels anticipated in the next century. Thus, understanding MMCO climate may help enlighten predictions of future climate change. Here, using new stable oxygen and carbon isotopes of fossil ungulate tooth enamel from before, during, and after the MMCO, we show that high pCO2 corresponds with warm-wet conditions, whereas low pCO2 corresponds with cool-dry conditions. We specifically show that mean annual precipitation (MAP), as inferred from tooth enamel δ13C values and corrected for atmospheric δ13C values (Δ13C), increased with increasing pCO2. Values of Δ13C > 19.5 ‰ in the lower John Day ( 27 Ma) and Mascall ( 15.3 Ma) localities imply relatively high mean annual precipitation (MAP = 550-850 mm/yr). Values of Δ 13C < 18.5 ‰ at 18 Ma and at four levels between 15 and 3 Ma imply low MAP (≤250 mm/yr), similar to modern climate. High MAP values generally correlate with high pCO2 levels, as inferred from marine records, implicating pCO2 as a principal driver of MAP in the Pacific Northwest. A climate oscillation model best explains our δ 13C data, such that warm-wet conditions during high pCO2 events alternated with cool-dry conditions during low pCO2 events on timescales of 100 kyr. The MMCO may have been more dynamic than originally considered, with wet-warm and cool-dry cycles reflecting Milankovitch cycles. High δ18O values in specimens from the John Day (21.8±0.6 ‰ V-SMOW) and Mascall (21.3±0.5 ‰) Formations may reflect lower elevations for the upwind Cascade Range prior to 7 Ma, or its proximity to the coast compared to more inland sites (δ18O = 17.7±0.9 to 19.6±1.1 ‰). Unusually high δ18O values of Dromomeryx sp. from Red Basin (27.4±0.6 ‰) most likely reflect drought tolerance. Climate models predict that as global atmospheric CO2 levels continue to increase, the Pacific Northwest will become wetter and warmer. Data collected in this study are from time periods geologically close to our own, and corroborate thes

Population Response Profiles in Early Visual Cortex Are Biased in Favor of More Valuable Stimuli

PubMed Central

Saproo, Sameer

2010-01-01

Voluntary and stimulus-driven shifts of attention can modulate the representation of behaviorally relevant stimuli in early areas of visual cortex. In turn, attended items are processed faster and more accurately, facilitating the selection of appropriate behavioral responses. Information processing is also strongly influenced by past experience and recent studies indicate that the learned value of a stimulus can influence relatively late stages of decision making such as the process of selecting a motor response. However, the learned value of a stimulus can also influence the magnitude of cortical responses in early sensory areas such as V1 and S1. These early effects of stimulus value are presumed to improve the quality of sensory representations; however, the nature of these modulations is not clear. They could reflect nonspecific changes in response amplitude associated with changes in general arousal or they could reflect a bias in population responses so that high-value features are represented more robustly. To examine this issue, subjects performed a two-alternative forced choice paradigm with a variable-interval payoff schedule to dynamically manipulate the relative value of two stimuli defined by their orientation (one was rotated clockwise from vertical, the other counterclockwise). Activation levels in visual cortex were monitored using functional MRI and feature-selective voxel tuning functions while subjects performed the behavioral task. The results suggest that value not only modulates the relative amplitude of responses in early areas of human visual cortex, but also sharpens the response profile across the populations of feature-selective neurons that encode the critical stimulus feature (orientation). Moreover, changes in space- or feature-based attention cannot easily explain the results because representations of both the selected and the unselected stimuli underwent a similar feature-selective modulation. This sharpening in the population response profile could theoretically improve the probability of correctly discriminating high-value stimuli from low-value alternatives. PMID:20410360

A clash of civilizations? Examining liberal-democratic values in Turkey and the European Union.

PubMed

Dixon, Jeffrey C

2008-12-01

Turkey's proposed entry into the European Union (EU) has been undermined by Europeans' perceptions of Turkish-European cultural differences, particularly regarding the liberal-democratic values that the EU promotes (democracy, rule of law, and respect for and appreciation of minority/human rights). Yet, cross-national research on values has not focused on Turkey, the EU, and these liberal-democratic values, leaving assumptions of cultural differences and their explanations untested. Through analyses of World and European Values Survey data (1999-2002), this article asks whether people in Turkey have the same values regarding democracy, rule of law (versus religious and authoritarian rule), and minority/human rights as people in EU member and candidate states (as of 2000)? What factors explain these values? I find that people in Turkey support democracy to the same extent as people in EU member and candidate states, but people in Turkey are more supportive of religious and authoritarian rule and are less tolerant of minorities. Although the 'clash of civilizations' thesis expects liberal values to be ordered according to countries' religious traditions, with western Christian the most supportive and Islamic the least, only for tolerance of minorities values is this pattern found. Instead, economic development most consistently explains differences between Turkey and EU member and candidate states in support for these values. I conclude with calls for theoretical refinement, particularly of the clash of civilizations thesis, along with suggestions for future research to examine more Muslim and Orthodox countries; I discuss the debate over Turkey's EU entry.

Social learning in cooperative dilemmas.

PubMed

Lamba, Shakti

2014-07-22

Helping is a cornerstone of social organization and commonplace in human societies. A major challenge for the evolutionary sciences is to explain how cooperation is maintained in large populations with high levels of migration, conditions under which cooperators can be exploited by selfish individuals. Cultural group selection models posit that such large-scale cooperation evolves via selection acting on populations among which behavioural variation is maintained by the cultural transmission of cooperative norms. These models assume that individuals acquire cooperative strategies via social learning. This assumption remains empirically untested. Here, I test this by investigating whether individuals employ conformist or payoff-biased learning in public goods games conducted in 14 villages of a forager-horticulturist society, the Pahari Korwa of India. Individuals did not show a clear tendency to conform or to be payoff-biased and are highly variable in their use of social learning. This variation is partly explained by both individual and village characteristics. The tendency to conform decreases and to be payoff-biased increases as the value of the modal contribution increases. These findings suggest that the use of social learning in cooperative dilemmas is contingent on individuals' circumstances and environments, and question the existence of stably transmitted cultural norms of cooperation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

The effect of spherical nanoparticles on rheological properties of bi-dispersed magnetorheological fluids

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

Kannappan, K. Thiruppathi, E-mail: thiruppathi.ka@gmail.com; Laherisheth, Zarana; Parekh, Kinnari

2015-06-24

In the present investigation, the rheological properties of bi-dispersed magnetorheological (MR) fluid based on Fe{sub 3}O{sub 4} nanosphere and microsphere of iron particles are experimentally investigated. The MR fluid is prepared by substituting nanosphere of 40nm Fe{sub 3}O{sub 4} particles in MR fluids having microsphere iron particles (7-8 μm). Three different weight fractions (0%, 1% and 3%) of nanosphere-microsphere MR fluids are synthesized. In the absence of the magnetic field, substitution of magnetic nanosphere decreases the viscosity lower than without substituted sample at high as well as low shear rate. Upon the application of the magnetic field, the particles alignmore » along the direction of the field, which promotes the yield stress. Here too the yield stress value decreases with magnetic nanosphere substitution. This behaviour is explain based on the inter-particle interaction as well as formation of nanosphere cloud around the magnetic microsphere, which effectively reduces the viscosity and works as weak point when chains are formed. Variation of dynamic yield stress with magnetic field is explained using microscopic model. In any event such fluid does not sediment and is not abrasive so it could be useful if not too high yield stress is needed.« less

Oil geochemistry of the northern Llanos Basin, Colombia. A model for migration

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

Ramon, J.C.; Dzou, L.

1996-12-31

The chemical composition of 23 crude oils and one oil seep from Llanos Basin, Colombia were studied in detail by geochemical methods in order to understand their genetic relationship. A filling history model is proposed to explain the observed composition variations in Llanos Basin oils. Geochemical fingerprinting indicates that there are six families of crude oils. The biomarker compositions have been used to identify characteristics of the source rocks. The Llanos oils contain marine algal- derived {open_quotes}C30 steranes{close_quotes} (i.e., 24-n-propylcholestanes), which are diagnostic for oils generated from marine Cretaceous source rocks. A significant HC-contribution from a Tertiary source is alsomore » indicated by the presence of high concentration of the {open_quotes}flowering plant{close_quotes}-markers oleanane, bicadinanes and oleanoids. Low DBT/Phen, %sulfur values and high diasteranes concentration indicate that the source rock is clay-rich. Biomarker maturity parameters indicate a wide range of source-rock thermal maturities from early to late oil window. Heavy biodegradation has been particularly common among the first oils to fill reservoirs in central Llanos oil fields. The older altered heavy oils were mixed with a second pulse of oil explaining the wide range of oil gravities measured in the central Llanos Basin.« less

Are personality differences in a small iteroparous mammal maintained by a life-history trade-off?

PubMed Central

Dammhahn, Melanie

2012-01-01

Despite increasing interest, animal personality is still a puzzling phenomenon. Several theoretical models have been proposed to explain intraindividual consistency and interindividual variation in behaviour, which have been primarily supported by qualitative data and simulations. Using an empirical approach, I tested predictions of one main life-history hypothesis, which posits that consistent individual differences in behaviour are favoured by a trade-off between current and future reproduction. Data on life-history were collected for individuals of a natural population of grey mouse lemurs (Microcebus murinus). Using open-field and novel-object tests, I quantified variation in activity, exploration and boldness for 117 individuals over 3 years. I found systematic variation in boldness between individuals of different residual reproductive value. Young males with low current but high expected future fitness were less bold than older males with high current fecundity, and males might increase in boldness with age. Females have low variation in assets and in boldness with age. Body condition was not related to boldness and only explained marginal variation in exploration. Overall, these data indicate that a trade-off between current and future reproduction might maintain personality variation in mouse lemurs, and thus provide empirical support of this life-history trade-off hypothesis. PMID:22398164

To what extent may changes in the root system architecture of Arabidopsis thaliana grown under contrasted homogenous nitrogen regimes be explained by changes in carbon supply? A modelling approach.

PubMed

Brun, François; Richard-Molard, Céline; Pagès, Loïc; Chelle, Michaël; Ney, Bertrand

2010-05-01

Root system architecture adapts to low nitrogen (N) nutrition. Some adaptations may be mediated by modifications of carbon (C) fluxes. The objective of this study was to test the hypothesis that changes in root system architecture under different N regimes may be accounted for by using simple hypotheses of C allocation within the root system of Arabidopsis thaliana. With that purpose, a model during vegetative growth was developed that predicted the main traits of root system architecture (total root length, lateral root number, and specific root length). Different experimental data sets crossing three C levels and two N homogenous nutrition levels were generated. Parameters were estimated from an experiment carried out under medium C and high N conditions. They were then checked under other CxN conditions. It was found that the model was able to simulate correctly C effects on root architecture in both high and low N nutrition conditions, with the same parameter values. It was concluded that C flux modifications explained the major part of root system adaptation to N supply, even if they were not sufficient to simulate some changes, such as specific root length.

Spatial Analysis of Gravity Data in the California, Nevada, and Utah (US)

NASA Astrophysics Data System (ADS)

Ferani, NA; Hartantyo, E.; Niasari, SW

2018-04-01

The geological condition of western North America is very complex because of the encounter of three major plates namely North America, Juan de Fuca, and Pacific Plate. The process of Juan de Fuca subduction and Pacific transform against North America plate created many mountains and produced Great Basin that we can see extending across California, Nevada, and Utah. The varied natural condition causes the varied value of gravity anomaly distribution. Using Topex free-air anomaly analyzed with second vertical derivative (SVD), we can analyze the fracture structures that occur in the Great Basin. The results show that the maximal SVD anomaly value is higher than the minimal SVD anomaly value at the western and eastern border of Great Basin. This explains that the two of Great Basin border are normal faults with trend direction NW-SE in the western boundary and NE-SW trending in the eastern boundary. This research result corresponds with the high seismicity data along the fault. Through this research, we can know that topex free-air anomaly data can be used to determine the type and trend of fault on a regional scale.

Geodesic synchrotron radiation in the Kerr geometry by the method of asymptotically factorized Green's functions

NASA Technical Reports Server (NTRS)

Chrzanowski, P. L.; Misner, C. W.

1974-01-01

The scalar, electromagnetic, and gravitational geodesic-synchrotron-radiation (GSR) spectra are determined for the case of a test particle moving on a highly relativistic circular orbit about a rotating (Kerr) black hole. It is found that the spectral shape depends only weakly on the value of the angular-momentum parameter (a/M) of the black hole, but the total radiated power drops unexpectedly for a value of at least 0.95 and vanishes as the value approaches unity. A spin-dependent factor (involving the inner product of the polarization of a radiated quantum with the source) is isolated to explain the dependence of the spectral shape on the spin of the radiated field. Although the scalar wave equation is solved by separation of variables, this procedure is avoided for the vector and tensor cases by postulating a sum-over-states expansion for the Green's function similar to that found to hold in the scalar case. The terms in this sum, significant for GSR, can then be evaluated in the geometric-optics approximation without requiring the use of vector or tensor spherical harmonics.

Competition strength influences individual preferences in an auction game

PubMed Central

Toelch, Ulf; Jubera-Garcia, Esperanza; Kurth-Nelson, Zeb; Dolan, Raymond J.

2014-01-01

Competitive interactions between individuals are ubiquitous in human societies. Auctions represent an institutionalized context for these interactions, a context where individuals frequently make non-optimal decisions. In particular, competition in auctions can lead to overbidding, resulting in the so-called winner’s curse, often explained by invoking emotional arousal. In this study, we investigated an alternative possibility, namely that competitors’ bids are construed as a source of information about the good’s common value thereby influencing an individuals’ private value estimate. We tested this hypothesis by asking participants to bid in a repeated all-pay auction game for five different real items. Crucially, participants had to rank the auction items for their preference before and after the experiment. We observed a clear relation between auction dynamics and preference change. We found that low competition reduced preference while high competition increased preference. Our findings support a view that competitors’ bids in auction games are perceived as valid social signal for the common value of an item. We suggest that this influence of social information constitutes a major cause for the frequently observed deviations from optimality in auctions. PMID:25168161

Individualism, collectivism, and Chinese adolescents' aggression: intracultural variations.

PubMed

Li, Yan; Wang, Mo; Wang, Cixin; Shi, Junqi

2010-01-01

This study examined the relations between cultural values (i.e., individualism and collectivism) and aggression among 460 (234 girls) Chinese adolescents. Conflict level and social status insecurity were examined as potential explaining mechanisms for these relations. The results showed that adolescents' endorsement of collectivism was negatively related to their use of overt and relational aggression as reported by teachers and peers, whereas positive associations were found between the endorsement of individualism and adolescent aggression. Adolescents' conflict level and social status insecurity accounted for a significant part of these associations. Findings of this study demonstrate the importance of examining intracultural variations of cultural values in relation to adolescent aggression as well as the process variables in explaining the relations. (c) 2010 Wiley-Liss, Inc.

Therapeutic Assessment of a Violent Criminal Offender: Managing the Cultural Narrative of Evil.

PubMed

Chudzik, Lionel

2016-01-01

Therapeutic Assessment (TA) emphasizes the importance of the clinical relationship and the core values of collaboration, respect, humility, compassion, and curiosity, which guide all aspects of the endeavor (Finn, 2007 ). Those values are not easy to apply with violent offenders. However, this article explains how TA can significantly contribute to the treatment of those clients by helping the therapist avoid common cultural narratives about evil. We see that these culturally based myths permit us to explain violent behaviors, but also prevent us from treating them because they lead us to a circular countertransference-transference process. Through a clinical case, I show how the TA process can help us to work empathically with violent people while addressing the dangerousness effectively.

Predictive value of dysregulation profile trajectories in childhood for symptoms of ADHD, anxiety and depression in late adolescence.

PubMed

Wang, B; Brueni, L G; Isensee, C; Meyer, T; Bock, N; Ravens-Sieberer, U; Klasen, F; Schlack, R; Becker, A; Rothenberger, A

2018-06-01

We examined whether there are certain dysregulation profile trajectories in childhood that may predict an elevated risk for mental disorders in later adolescence. Participants (N = 554) were drawn from a representative community sample of German children, 7-11 years old, who were followed over four measurement points (baseline, 1, 2 and 6 years later). Dysregulation profile, derived from the parent report of the Strengths and Difficulties Questionnaire, was measured at the first three measurement points, while symptoms of attention deficit hyperactivity disorder (ADHD), anxiety and depression were assessed at the fourth measurement point. We used latent class growth analysis to investigate developmental trajectories in the development of the dysregulation profile. The predictive value of dysregulation profile trajectories for later ADHD, anxiety and depression was examined by linear regression. For descriptive comparison, the predictive value of a single measurement (baseline) was calculated. Dysregulation profile was a stable trait during childhood. Boys and girls had similar levels of dysregulation profile over time. Two developmental subgroups were identified, namely the low dysregulation profile and the high dysregulation profile trajectory. The group membership in the high dysregulation profile trajectory (n = 102) was best predictive of later ADHD, regardless of an individual's gender and age. It explained 11% of the behavioural variance. For anxiety this was 8.7% and for depression 5.6%, including some gender effects. The single-point measurement was less predictive. An enduring high dysregulation profile in childhood showed some predictive value for psychological functioning 4 years later. Hence, it might be helpful in the preventive monitoring of children at risk.

The ortho-to-para ratio of interstellar NH2: quasi-classical trajectory calculations and new simulations

NASA Astrophysics Data System (ADS)

Le Gal, R.; Herbst, E.; Xie, C.; Li, A.; Guo, H.

2016-11-01

Based on recent Herschel results, the ortho-to-para ratio (OPR) of NH2 has been measured towards the following high-mass star-forming regions: W31C (G10.6-0.4), W49N (G43.2-0.1), W51 (G49.5-0.4), and G34.3+0.1. The OPR at thermal equilibrium ranges from the statistical limit of three at high temperatures to infinity as the temperature tends toward zero, unlike the case of H2. Depending on the position observed along the lines-of-sight, the OPR was found to lie either slightly below the high temperature limit of three (in the range 2.2-2.9) or above this limit ( 3.5, ≳ 4.2, and ≳5.0). In low temperature interstellar gas, where the H2 is para-enriched, our nearly pure gas-phase astrochemical models with nuclear-spin chemistry can account for anomalously low observed NH2-OPR values. We have tentatively explained OPR values larger than three by assuming that spin thermalization of NH2 can proceed at least partially by H-atom exchange collisions with atomic hydrogen, thus increasing the OPR with decreasing temperature. In this paper, we present quasi-classical trajectory calculations of the H-exchange reaction NH2 + H, which show the reaction to proceed without a barrier, confirming that the H-exchange will be efficient in the temperature range of interest. With the inclusion of this process, our models suggest both that OPR values below three arise in regions with temperatures ≳20-25 K, depending on time, and values above three but lower than the thermal limit arise at still lower temperatures.

Diastolic blood pressure, aortic atheroma, and prognosis in hypertension: new insights into a complex association.

PubMed

Courand, Pierre-Yves; Milon, Hugues; Bricca, Giampiero; Khettab, Fouad; Lantelme, Pierre

2014-03-01

Our study aimed at determining the interaction between the prognostic value of diastolic blood pressure (DBP) and aortic atherosclerosis (ATS). With aging, equal systolic blood pressures (SBPs) become associated with low DBPs; i.e., high pulse pressures (PPs) become associated with a high risk of cardiovascular death. This association is usually ascribed to aortic stiffening with age but the precise impact of low DBP per se is yet uncertain. 938 hypertensive patients recruited in the seventies had an aortic ATS score at pretreatment aortography. All-cause and cardiovascular deaths were assessed 20 years later. The prognostic values of DBP and SBP were assessed by a multivariate Cox regression model and their interactions with ATS examined. In the presence of ATS, an increase of 10 mmHg in DBP was associated with a protective effect: hazard ratios 0.84 [0.72-0.99] for cardiovascular death and 0.88 [0.78-1.00] for all-cause death. However, in the absence of ATS, DBP had no prognostic value: hazard ratios 1.05 [0.89-1.23] for cardiovascular death and 0.99 [0.88-1.11] for all-cause death (p for interaction: 0.061 and 0.087, respectively). No interaction was found between SBP and ATS (p for interaction > 0.40). The prognostic values of DBP and aortic atheroma are not superimposable; yet, they are tightly connected: a low DBP is disadvantageous only in the presence of a pathologic aorta. Aortic atherosclerosis may explain, at least partly, in some high risk populations, the J-shape of the already reported DBP-outcome relationship. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Predicting dynamic knee joint load with clinical measures in people with medial knee osteoarthritis.

PubMed

Hunt, Michael A; Bennell, Kim L

2011-08-01

Knee joint loading, as measured by the knee adduction moment (KAM), has been implicated in the pathogenesis of knee osteoarthritis (OA). Given that the KAM can only currently be accurately measured in the laboratory setting with sophisticated and expensive equipment, its utility in the clinical setting is limited. This study aimed to determine the ability of a combination of four clinical measures to predict KAM values. Three-dimensional motion analysis was used to calculate the peak KAM at a self-selected walking speed in 47 consecutive individuals with medial compartment knee OA and varus malalignment. Clinical predictors included: body mass; tibial angle measured using an inclinometer; walking speed; and visually observed trunk lean toward the affected limb during the stance phase of walking. Multiple linear regression was performed to predict KAM magnitudes using the four clinical measures. A regression model including body mass (41% explained variance), tibial angle (17% explained variance), and walking speed (9% explained variance) explained a total of 67% of variance in the peak KAM. Our study demonstrates that a set of measures easily obtained in the clinical setting (body mass, tibial alignment, and walking speed) can help predict the KAM in people with medial knee OA. Identifying those patients who are more likely to experience high medial knee loads could assist clinicians in deciding whether load-modifying interventions may be appropriate for patients, whilst repeated assessment of joint load could provide a mechanism to monitor disease progression or success of treatment. Copyright © 2010 Elsevier B.V. All rights reserved.

Parent and Student Guide to High School Superintendent Suspension Hearings.

ERIC Educational Resources Information Center

Advocates for Children of New York, Inc., Long Island City.

This guide has been written to help parents represent their children at New York City Board of Education hearings. The guide explains the rights of parents and children and explains the steps a parent should take in representing the child. It only applies to regular education high school suspensions. Sections of the guide explain: (1) reasons a…

Are dual isotope and isotopomer ratios of N2O useful indicators for N2O turnover during denitrification in nitrate-contaminated aquifers?

NASA Astrophysics Data System (ADS)

Well, Reinhard; Eschenbach, Wolfram; Flessa, Heinz; von der Heide, Carolin; Weymann, Daniel

2012-08-01

Denitrifying aquifers are sources of the greenhouse gas N2O. Isotopic signatures reflect processes of production and reduction of N2O, but it is not clear to which extent these can be used to quantify those processes. We investigated the spatial distribution of isotopologue values of N2O (δ18O, average δ15N, and 15N site preference, SP) in two denitrifying sandy aquifers to study N2O production and reduction and associated isotope effects in groundwater. For the first time, we combined this approach with direct estimation of N2O reduction from excess-N2 analysis. Groundwater samples were collected from 15 monitoring wells and four multilevel sampling wells and analysed for NO3-, dissolved N2O, dissolved O2, excess N2 from denitrification and isotopic signatures of NO3- and N2O. Both aquifers exhibited high NO3- concentrations with average concentrations of 22 and 15 mg N L-1, respectively. Evidence of intense denitrification with associated N2O formation was obtained from mean excess-N2 of 3.5 and 4.3 mg N L-1, respectively. Isotopic signatures of N2O were highly variable with ranges of 17.6-113.2‰ (δ18O), -55.4 to 89.4‰ (δ15Nbulk) and 1.8-97.9‰ (SP). δ15N and δ18O of NO3- ranged from -2.1‰ to 65.5‰ and from -5‰ to 33.5‰, respectively. The relationships between δ15N of NO3-, δ15Nbulk and SP were not in good agreement with the distribution predicted by a Rayleigh-model of isotope fractionation. The large ranges of δ18O and SP of N2O as well as the close correlation between these values could be explained by the fact that N2O reduction to N2 was strongly progressed but variable. We confirm and explain that a large range in SP and δ18O is typical for N2O from denitrifying aquifers, showing that this source signature can be distinguished from the isotopic fingerprint of N2O emitted from soils without water-logging. We conclude that isotopologue values of N2O in our sites were not suitable to quantify production or reduction of N2O or the contribution of different processes to the total N2O flux, apparently because these values were not only governed by individual pathways but eventually also by the spatial distribution of substrates and activity within the aquifers. These observations could be explained by the dynamics of N2O production, reduction and transport in water-saturated systems with heterogenic distribution of microbial activity and by a combination of diffusive and enzymatic isotope effects.

Cultural values: can they explain self-reported health?

PubMed

Roudijk, Bram; Donders, Rogier; Stalmeier, Peep

2017-06-01

Self-reported health (SRH) is a measure widely used in health research and population studies. Differences in SRH have been observed between countries and cultural values have been hypothesized to partly explain such differences. Cultural values can be operationalized by two cultural dimensions using the World Values Survey (WVS), namely the traditional/rational-secular and the survival/self-expression dimension. We investigate whether there is an association between the WVS cultural dimensions and SRH, both within and between countries. Data from 51 countries in the WVS is used and combined with macroeconomic data from the Worldbank database. The association between SRH and the WVS cultural dimensions is tested within each of the 51 countries and multilevel mixed models are used to test differences between these countries. Socio-demographic and macroeconomic variables are used to correct for non-cultural variables related to SRH. Within countries, the survival/self-expression dimension was positively associated with SRH, while in most countries there was a negative association for the traditional/rational-secular dimension. Values range between 4 and 17% within countries. Further analyses show that the associations within countries and between countries are similar. Controlling for macroeconomic and socio-demographic factors did not change our results. The WVS cultural dimensions predict SRH within and between countries. Contrary to our expectations, traditional/rational-secular values were negatively associated with SRH. As SRH is associated with cultural values between countries, cultural values could be considered when interpreting SRH between countries.

Detecting microRNAs of high influence on protein functional interaction networks: a prostate cancer case study

PubMed Central

2012-01-01

Background The use of biological molecular network information for diagnostic and prognostic purposes and elucidation of molecular disease mechanism is a key objective in systems biomedicine. The network of regulatory miRNA-target and functional protein interactions is a rich source of information to elucidate the function and the prognostic value of miRNAs in cancer. The objective of this study is to identify miRNAs that have high influence on target protein complexes in prostate cancer as a case study. This could provide biomarkers or therapeutic targets relevant for prostate cancer treatment. Results Our findings demonstrate that a miRNA’s functional role can be explained by its target protein connectivity within a physical and functional interaction network. To detect miRNAs with high influence on target protein modules, we integrated miRNA and mRNA expression profiles with a sequence based miRNA-target network and human functional and physical protein interactions (FPI). miRNAs with high influence on target protein complexes play a role in prostate cancer progression and are promising diagnostic or prognostic biomarkers. We uncovered several miRNA-regulated protein modules which were enriched in focal adhesion and prostate cancer genes. Several miRNAs such as miR-96, miR-182, and miR-143 demonstrated high influence on their target protein complexes and could explain most of the gene expression changes in our analyzed prostate cancer data set. Conclusions We describe a novel method to identify active miRNA-target modules relevant to prostate cancer progression and outcome. miRNAs with high influence on protein networks are valuable biomarkers that can be used in clinical investigations for prostate cancer treatment. PMID:22929553

Temperament, character and serotonin activity in the human brain: a positron emission tomography study based on a general population cohort.

PubMed

Tuominen, L; Salo, J; Hirvonen, J; Någren, K; Laine, P; Melartin, T; Isometsä, E; Viikari, J; Cloninger, C R; Raitakari, O; Hietala, J; Keltikangas-Järvinen, L

2013-04-01

The psychobiological model of personality by Cloninger and colleagues originally hypothesized that interindividual variability in the temperament dimension 'harm avoidance' (HA) is explained by differences in the activity of the brain serotonin system. We assessed brain serotonin transporter (5-HTT) density in vivo with positron emission tomography (PET) in healthy individuals with high or low HA scores using an 'oversampling' study design. Method Subjects consistently in either upper or lower quartiles for the HA trait were selected from a population-based cohort in Finland (n = 2075) with pre-existing Temperament and Character Inventory (TCI) scores. A total of 22 subjects free of psychiatric and somatic disorders were included in the matched high- and low-HA groups. The main outcome measure was regional 5-HTT binding potential (BPND) in high- and low-HA groups estimated with PET and [11C]N,N-dimethyl-2-(2-amino-4-methylphenylthio)benzylamine ([11C]MADAM). In secondary analyses, 5-HTT BPND was correlated with other TCI dimensions. 5-HTT BPND did not differ between high- and low-HA groups in the midbrain or any other brain region. This result remained the same even after adjusting for other relevant TCI dimensions. Higher 5-HTT BPND in the raphe nucleus predicted higher scores in 'self-directedness'. This study does not support an association between the temperament dimension HA and serotonin transporter density in healthy subjects. However, we found a link between high serotonin transporter density and high 'self-directedness' (ability to adapt and control one's behaviour to fit situations in accord with chosen goals and values). We suggest that biological factors are more important in explaining variability in character than previously thought.

Expelled grains from an unseen parent body around AU Microscopii

NASA Astrophysics Data System (ADS)

Sezestre, É.; Augereau, J.-C.; Boccaletti, A.; Thébault, P.

2017-11-01

Context. Recent observations of the edge-on debris disk of AU Mic have revealed asymmetric, fast outward-moving arch-like structures above the disk midplane. Although asymmetries are frequent in debris disks, no model can readily explain the characteristics of these features. Aims: We present a model aiming to reproduce the dynamics of these structures, more specifically their high projected speeds and their apparent position. We test the hypothesis of dust emitted by a point source and then expelled from the system by the strong stellar wind of this young M-type star. In this model we make the assumption that the dust grains follow the same dynamics as the structures, I.e., they are not local density enhancements. Methods: We perform numerical simulations of test particle trajectories to explore the available parameter space, in particular the radial location R0 of the dust producing parent body and the size of the dust grains as parameterized by the value of β (ratio of stellar wind and radiation pressure forces over gravitation). We consider the cases of a static and of an orbiting parent body. Results: We find that for all considered scenarios (static or moving parent body), there is always a set of (R0,β) parameters able to fit the observed features. The common characteristics of these solutions is that they all require a high value of β, of around 6. This means that the star is probably very active, and the grains composing the structures are submicronic in order for observable grains to reach such high β values. We find that the location of the hypothetical parent body is closer in than the planetesimal belt, around 8 ± 2 au (orbiting case) or 28 ± 7 au (static case). A nearly periodic process of dust emission appears, of 2 yr in the orbiting scenarios and 7 yr in the static case. Conclusions: We show that the scenario of sequential dust releases by an unseen point-source parent body is able to explain the radial behavior of the observed structures. We predict the evolution of the structures to help future observations discriminate between the different parent body configurations that have been considered. In the orbiting parent body scenario, we expect new structures to appear on the northwest side of the disk in the coming years.

Thermal maturity patterns in Pennsylvanian coal-bearing rocks in Alabama, Tennessee, Kentucky, Virginia, West Virginia, Ohio, Maryland, and Pennsylvania: Chapter F.2 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

USGS Publications Warehouse

Ruppert, Leslie F.; Trippi, Michael H.; Hower, James C.; Grady, William C.; Levine, Jeffrey R.; Ruppert, Leslie F.; Ryder, Robert T.

2014-01-01

Thermal maturation patterns of Pennsylvanian strata in the Appalachian basin and part of the Black Warrior basin were determined by compiling previously published and unpublished percent-vitrinite-reflectance (%R0) measurements and preparing isograd maps on the basis of the measurements. The isograd values range from 0.6 %R0 in Ohio and the western side of the Eastern Kentucky coal field to 5.5 %R0 in the Southern field in the Pennsylvania Anthracite region, Schuylkill County, Pa. The vitrinite-reflectance values correspond to the American Society of Testing Materials (ASTM) coal-rank classes of high-volatile C bituminous to meta-anthracite, respectively. In general, the isograds show that thermal maturity patterns of Pennsylvanian coals within the Appalachian basin generally decrease from east to west. In the Black Warrior basin of Alabama, the isograds show a circular pattern with the highest values (greater than 1.6 %R0) centered in Jefferson County, Ala. Most of the observed patterns can be explained by variations in the depth of burial, variations in geothermal gradient, or a combination of both; however, there are at least four areas of higher ranking coal in the Appalachian basin that are difficult to explain by these two processes alone: (1) a set of west- to northwest-trending salients centered in Somerset, Cambria, and Fayette Counties, Pa.; (2) an elliptically shaped, northeast-trending area centered in southern West Virginia and western Virginia; (3) the Pennsylvania Anthracite region in eastern Pennsylvania; and (4) the eastern part of the Black Warrior coal field in Alabama. The areas of high-ranking coal in southwestern Pennsylvania, the Black Warrior coal field, and the Pennsylvania Anthracite region are interpreted here to represent areas of higher paleo-heat flow related to syntectonic movement of hot fluids towards the foreland associated with Alleghanian deformation. In addition to the higher heat flow from these fluids, the Pennsylvania Anthracite region also was buried more deeply than other parts of the Appalachian basin. The area of high rank coal in southwestern Virginia probably was controlled primarily by overburden thickness, but may also have been influenced by higher geothermal gradients.

Effect of hot carcass weight on loin, ham, and belly quality from pigs sourced from a commercial processing facility,.

PubMed

Harsh, B N; Arkfeld, E K; Mohrhauser, D A; King, D A; Wheeler, T L; Dilger, A C; Shackelford, S D; Boler, D D

2017-11-01

The objective was to determine the predictive abilities of HCW for loin, ham, and belly quality of 7,684 pigs with carcass weights ranging from 53.2 to 129.6 kg. Carcass composition, subjective loin quality, and ham face color were targeted on all carcasses, whereas in-plant instrumental loin color and belly quality were assessed on 52.0 and 47.5% of carcasses, respectively. Loin chop slice shear force (SSF), cured ham quality, and adipose iodine value (IV) were evaluated on at least 10% of the population. The slope of regression lines and coefficients of determination between HCW and quality traits were computed using PROC REG of SAS and considered significant at ≤ 0.05. As HCW increased, boneless loins became darker and redder, evidenced by lower L* (β = -0.0243, < 0.001) and greater a* values (β = 0.0106, < 0.001); however, HCW accounted for only ≤0.80% of the variability in loin L* and a* values. Similarly, subjective loin color score (β = 0.0024, < 0.001) increased with increasing carcass weight, but subjective marbling score was not affected by HCW (β = -0.0022, = 0.06). After 20 d of aging, HCW explained only 0.98% of the variability in loin L* values (β = -0.0287, < 0.01). Heavier carcasses had lower SSF values (β = -0.1269, < 0.001) of LM chops, although HCW explained only 4.46% of the variability in SSF. Although heavier carcasses produced loins that exhibited lower ultimate pH values (β = -0.0018, < 0.001), HCW explained only 1.23% of the variability in ultimate loin pH. Interestingly, cook loss decreased (β = -0.0521, < 0.001) as HCW increased, with HCW accounting for 5.60% of the variability in cook loss. Heavier carcasses resulted in darker, redder ham face color ( < 0.001), but HCW accounted for only ≤2.87% of the variability in ham face L* values and 0.47% of the variability in a* values. Heavier carcasses produced thicker and firmer bellies, with HCW accounting for 37.81% of the variability in belly thickness (β = 0.0272, < 0.001), 20.35% of the variability in subjective flop score (β = 0.0406, < 0.001), and 10.35% of the variability in IV (β = -0.1263, < 0.001). Overall, the proportion of variability in loin and ham quality explained by HCW was poor (≤5.60%), suggesting that HCW is a poor predictor of the primal quality of pigs within this weight range. Nonetheless, HCW was a moderate predictor of belly quality traits. The findings of this study suggest that increasing HCW did not compromise loin, ham, or belly quality attributes.

Voluntary Consent: Why a Value-Neutral Concept Won’t Work

PubMed Central

Wertheimer, Alan

2012-01-01

Some maintain that voluntariness is a value-neutral concept. On that view, someone acts involuntarily if subject to a controlling influence or has no acceptable alternatives. I argue that a value-neutral conception of voluntariness cannot explain when and why consent is invalid and that we need a moralized account of voluntariness. On that view, most concerns about the voluntariness of consent to participate in research are not well founded. PMID:22551878

Characterization of protein folding by a Φ-value calculation with a statistical-mechanical model.

PubMed

Wako, Hiroshi; Abe, Haruo

2016-01-01

The Φ-value analysis approach provides information about transition-state structures along the folding pathway of a protein by measuring the effects of an amino acid mutation on folding kinetics. Here we compared the theoretically calculated Φ values of 27 proteins with their experimentally observed Φ values; the theoretical values were calculated using a simple statistical-mechanical model of protein folding. The theoretically calculated Φ values reflected the corresponding experimentally observed Φ values with reasonable accuracy for many of the proteins, but not for all. The correlation between the theoretically calculated and experimentally observed Φ values strongly depends on whether the protein-folding mechanism assumed in the model holds true in real proteins. In other words, the correlation coefficient can be expected to illuminate the folding mechanisms of proteins, providing the answer to the question of which model more accurately describes protein folding: the framework model or the nucleation-condensation model. In addition, we tried to characterize protein folding with respect to various properties of each protein apart from the size and fold class, such as the free-energy profile, contact-order profile, and sensitivity to the parameters used in the Φ-value calculation. The results showed that any one of these properties alone was not enough to explain protein folding, although each one played a significant role in it. We have confirmed the importance of characterizing protein folding from various perspectives. Our findings have also highlighted that protein folding is highly variable and unique across different proteins, and this should be considered while pursuing a unified theory of protein folding.

Characterization of protein folding by a Φ-value calculation with a statistical-mechanical model

PubMed Central

Wako, Hiroshi; Abe, Haruo

2016-01-01

The Φ-value analysis approach provides information about transition-state structures along the folding pathway of a protein by measuring the effects of an amino acid mutation on folding kinetics. Here we compared the theoretically calculated Φ values of 27 proteins with their experimentally observed Φ values; the theoretical values were calculated using a simple statistical-mechanical model of protein folding. The theoretically calculated Φ values reflected the corresponding experimentally observed Φ values with reasonable accuracy for many of the proteins, but not for all. The correlation between the theoretically calculated and experimentally observed Φ values strongly depends on whether the protein-folding mechanism assumed in the model holds true in real proteins. In other words, the correlation coefficient can be expected to illuminate the folding mechanisms of proteins, providing the answer to the question of which model more accurately describes protein folding: the framework model or the nucleation-condensation model. In addition, we tried to characterize protein folding with respect to various properties of each protein apart from the size and fold class, such as the free-energy profile, contact-order profile, and sensitivity to the parameters used in the Φ-value calculation. The results showed that any one of these properties alone was not enough to explain protein folding, although each one played a significant role in it. We have confirmed the importance of characterizing protein folding from various perspectives. Our findings have also highlighted that protein folding is highly variable and unique across different proteins, and this should be considered while pursuing a unified theory of protein folding. PMID:28409079

Quantifying spatial patterns in the Yakama Nation Tribal Forest and Okanogan-Wenatchee National Forest to assess forest health

NASA Astrophysics Data System (ADS)

Wilder, T. F.

2013-05-01

Over the past century western United States have experienced drastic anthropogenic land use change from practices such as agriculture, fire exclusion, and timber harvesting. These changes have complex social, cultural, economic, and ecological interactions and consequences. This research studied landscapes patterns of watersheds with similar LANDFIRE potential vegetation in the Southern Washington Cascades physiographic province, within the Yakama Nation Tribal Forest (YTF) and Okanogan-Wenatchee National Forest, Naches Ranger District (NRD). In the selected watersheds, vegetation-mapping units were delineated and populated based on physiognomy of homogeneous areas of vegetative composition and structure using high-resolution aerial photos. Cover types and structural classes were derived from the raw, photo-interpreted vegetation attributes for individual vegetation mapping units and served as individual and composite response variables to quantify and assess spatial patterns and forest health conditions between the two ownerships. Structural classes in both the NRD and YTF were spatially clustered (Z-score 3.1, p-value 0.01; Z-score 2.3, p-value 0.02, respectively), however, ownership and logging type both explained a significant amount of variance in structural class composition. Based on FRAGSTATS landscape metrics, structural classes in the NRD displayed greater clustering and fragmentation with lower interspersion relative to the YTF. The NRD landscape was comprised of 47.4% understory reinitiation structural class type and associated high FRAGASTAT class metrics demonstrated high aggregation with moderate interspersion. Stem exclusion open canopy displayed the greatest dispersal of structural class types throughout the NRD, but adjacencies were correlated to other class types. In the YTF, stem exclusion open canopy comprised 37.7% of the landscape and displayed a high degree of aggregation and interspersion about clusters throughout the YTF. Composite cover type-structural class spatial autocorrelation was clustered in the NRD (Z-score 5.1, p-value 0.01), while the YTF exhibited a random spatial pattern. After accounting for location effects, logging type was the most significant factor explaining variation in composite cover-structure composition. FRAGSTATS landscape metrics identified composite cover-structure classes in the NRD displayed greater aggregation and fragmentation with lower interspersion relative to the YTF. The NRD landscape was comprised of 30.5% Pinus ponderosa-understory reinitiation and associated class metrics demonstrated a high degree of aggregation and fragmentation with low interspersion. Pinus ponderosa-stem exclusion open canopy comprised 24.6% of the YTF landscape and associated class metrics displayed moderate aggregation and fragmentation with high interspersion. A discussion integrating the results and existing relevant literature was indited to assess management regime influences on landscape patterns and, in turn, forest health attributes. This dialog is in provision of enhancing collaboration to optimize forest-health restoration activities across ownerships throughout the study area.

Double-gated Si NW FET sensors: Low-frequency noise and photoelectric properties

NASA Astrophysics Data System (ADS)

Gasparyan, F.; Khondkaryan, H.; Arakelyan, A.; Zadorozhnyi, I.; Pud, S.; Vitusevich, S.

2016-08-01

The transport, noise, and photosensitivity properties of an array of silicon nanowire (NW) p+-p-p+ field-effect transistors (FETs) are investigated. The peculiarities of photosensitivity and detectivity are analyzed over a wide spectrum range. The absorbance of p-Si NW shifts to the short wavelength region compared with bulk Si. The photocurrent and photosensitivity reach increased values in the UV range of the spectrum at 300 K. It is shown that sensitivity values can be tuned by the drain-source voltage and may reach record values of up to 2-4 A/W at a wavelength of 300 nm at room temperature. Low-frequency noise studies allow calculating the photodetectivity values, which increase with decreasing wavelength down to 300 nm. We show that the drain current of Si NW biochemical sensors substantially depends on pH value and the signal-to-noise ratio reaches the high value of 105. Increasing pH sensitivity with gate voltage is revealed for certain source-drain currents of pH-sensors based on Si NW FETs. The noise characteristic index decreases from 1.1 to 0.7 with the growth of the liquid gate voltage. Noise behavior is successfully explained in the framework of the correlated number-mobility unified fluctuation model. pH sensitivity increases as a result of the increase in liquid gate voltage, thus giving the opportunity to measure very low proton concentrations in the electrolyte medium at certain values of the liquid gate voltage.

Random Sampling with Interspike-Intervals of the Exponential Integrate and Fire Neuron: A Computational Interpretation of UP-States

PubMed Central

Steimer, Andreas; Schindler, Kaspar

2015-01-01

Oscillations between high and low values of the membrane potential (UP and DOWN states respectively) are an ubiquitous feature of cortical neurons during slow wave sleep and anesthesia. Nevertheless, a surprisingly small number of quantitative studies have been conducted only that deal with this phenomenon’s implications for computation. Here we present a novel theory that explains on a detailed mathematical level the computational benefits of UP states. The theory is based on random sampling by means of interspike intervals (ISIs) of the exponential integrate and fire (EIF) model neuron, such that each spike is considered a sample, whose analog value corresponds to the spike’s preceding ISI. As we show, the EIF’s exponential sodium current, that kicks in when balancing a noisy membrane potential around values close to the firing threshold, leads to a particularly simple, approximative relationship between the neuron’s ISI distribution and input current. Approximation quality depends on the frequency spectrum of the current and is improved upon increasing the voltage baseline towards threshold. Thus, the conceptually simpler leaky integrate and fire neuron that is missing such an additional current boost performs consistently worse than the EIF and does not improve when voltage baseline is increased. For the EIF in contrast, the presented mechanism is particularly effective in the high-conductance regime, which is a hallmark feature of UP-states. Our theoretical results are confirmed by accompanying simulations, which were conducted for input currents of varying spectral composition. Moreover, we provide analytical estimations of the range of ISI distributions the EIF neuron can sample from at a given approximation level. Such samples may be considered by any algorithmic procedure that is based on random sampling, such as Markov Chain Monte Carlo or message-passing methods. Finally, we explain how spike-based random sampling relates to existing computational theories about UP states during slow wave sleep and present possible extensions of the model in the context of spike-frequency adaptation. PMID:26203657

Sulfur geochemistry of hydrothermal waters in Yellowstone National Park: IV Acid-sulfate waters

USGS Publications Warehouse

Nordstrom, D. Kirk; McCleskey, R. Blaine; Ball, J.W.

2009-01-01

Many waters sampled in Yellowstone National Park, both high-temperature (30-94 ??C) and low-temperature (0-30 ??C), are acid-sulfate type with pH values of 1-5. Sulfuric acid is the dominant component, especially as pH values decrease below 3, and it forms from the oxidation of elemental S whose origin is H2S in hot gases derived from boiling of hydrothermal waters at depth. Four determinations of pH were obtained: (1) field pH at field temperature, (2) laboratory pH at laboratory temperature, (3) pH based on acidity titration, and (4) pH based on charge imbalance (at both laboratory and field temperatures). Laboratory pH, charge imbalance pH (at laboratory temperature), and acidity pH were in close agreement for pH ??10%, a selection process was used to compare acidity, laboratory, and charge balance pH to arrive at the best estimate. Differences between laboratory and field pH can be explained based on Fe oxidation, H2S or S2O3 oxidation, CO2 degassing, and the temperature-dependence of pK2 for H2SO4. Charge imbalances are shown to be dependent on a speciation model for pH values 350 mg/L Cl) decrease as the Cl- concentration increases from boiling which appears inconsistent with the hypothesis of H2S oxidation as a source of hydrothermal SO4. This trend is consistent with the alternate hypothesis of anhydrite solubility equilibrium. Acid-sulfate water analyses are occasionally high in As, Hg, and NH3 concentrations but in contrast to acid mine waters they are low to below detection in Cu, Zn, Cd, and Pb concentrations. Even concentrations of SO4, Fe, and Al are much lower in thermal waters than acid mine waters of the same pH. This difference in water chemistry may explain why certain species of fly larvae live comfortably in Yellowstone's acid waters but have not been observed in acid rock drainage of the same pH.

A satellite-based 13-year climatology of net cloud radiative forcing over the Indian monsoon region

NASA Astrophysics Data System (ADS)

Saud, Trailokya; Dey, Sagnik; Das, Sushant; Dutta, Soumi

2016-12-01

We present a satellite-based 13-year (Mar. 2000-Feb. 2013) climatology of net cloud radiative forcing (CRF) over the Indian monsoon region (0-40°N, 60-100°E) using the Clouds and Earth's Radiant Energy System (CERES) radiation data and explained the net CRF variability in terms of cloud properties retrieved by Moderate Resolution Imaging Spectroradiometer (MODIS). Mean (± 1σ) seasonal shortwave (SW) CRF values averaged over the region are - 82.7 ± 24.5, - 32.1 ± 12.1, - 17.2 ± 5.3 and - 30.2 ± 16.2 W m- 2 respectively for the monsoon (JJAS), post-monsoon (ON), winter (DJF) and pre-monsoon (MAM) seasons; while the corresponding longwave (LW) CRF values are 53.7 ± 14.2, 27.9 ± 10.0, 15.8 ± 7.0 and 25.2 ± 9.1 W m- 2. Regional analysis reveals the largest (least) negative net CRF over the northeast (northwest) rainfall homogeneous zone throughout the year due to the dominance of optically thick high clouds (low cloud fraction, fc). Mean JJAS fc is found to increase (by > 0.01 per year) over large parts of the Arabian Sea, Bay of Bengal and the northwest region. Mean annual net CRF values for cumulus, stratocumulus and stratus (low level), altocumulus, altostratus and nimbostratus (mid-level clouds) and cirrus, cirrostratus and deep-convective (high level) clouds over the Indian monsoon region are estimated to be - 0.8, - 4.7, - 6.9, + 3.3, - 6.3, - 23.3, + 5.4, - 23.3 and - 42.1 W m- 2 respectively. Across a wide range of cloud optical depth (COD) and fc < 0.6, near cancellation of SW cooling by LW warming, is observed for low clouds. Net CRF drops below - 15 W m- 2 for clouds evolving above 400 hPa, mainly in the monsoon season. Our results demonstrate that net CRF variability in the Indian monsoon region can be explained by variability in Cloud Top Pressure (CTP), COD and fc. The study highlights the need for resolving a multi-layer cloud field in the future.

Theory of high-force DNA stretching and overstretching.

PubMed

Storm, C; Nelson, P C

2003-05-01

Single-molecule experiments on single- and double-stranded DNA have sparked a renewed interest in the force versus extension of polymers. The extensible freely jointed chain (FJC) model is frequently invoked to explain the observed behavior of single-stranded DNA, but this model does not satisfactorily describe recent high-force stretching data. We instead propose a model (the discrete persistent chain) that borrows features from both the FJC and the wormlike chain, and show that it resembles the data more closely. We find that most of the high-force behavior previously attributed to stretch elasticity is really a feature of the corrected entropic elasticity; the true stretch compliance of single-stranded DNA is several times smaller than that found by previous authors. Next we elaborate our model to allow coexistence of two conformational states of DNA, each with its own stretch and bend elastic constants. Our model is computationally simple and gives an excellent fit through the entire overstretching transition of nicked, double-stranded DNA. The fit gives the first value for the bend stiffness of the overstretched state. In particular, we find the effective bend stiffness for DNA in this state to be about 12 nm k(B)T, a value quite different from either the B-form or single-stranded DNA.

Fabrication of Nd3+ and Mn2+ ions Co-doped Spinal Strontium Nanoferrites for High Frequency Device Applications

NASA Astrophysics Data System (ADS)

Ahmad, Iqbal; Shah, Syed Mujtaba; Ashiq, Muhammad Naeem; Nawaz, Faisal; Shah, Afzal; Siddiq, Muhammad; Fahim, Iqra; Khan, Samiullah

2016-10-01

Microemulsion method has been used for the synthesis of high resistive spinal nanoferrites with nominal composition Sr1- x Nd x Fe2- y Mn y O4 (0.0 ≤ x ≤ 0.1, 0.0 ≤ y ≤ 1.0) for high frequency device applications. It has been confirmed by x-ray diffraction (XRD) results that these ferrites have a cubic spinal structure with a mean crystallite size ranging from 34 mm to 47 nm. The co-substitution of Nd3+ and Mn2+ ions was performed, and its effect on electrical, dielectric and impedance properties was analyzed employing direct current (DC) resistivity measurements, dielectric measurements and electrochemical impedance spectroscopy (EIS). The DC resistivity ( ρ) value was the highest for the composition Sr0.90Nd0.1FeMnO4, but for the same composition, dielectric parameters and alternating current (AC) conductivity showed their minimum values. In the lower frequency range, the magnitudes of dielectric parameters decrease with increasing frequency and show an almost independent frequency response at higher frequencies. Dielectric polarization has been employed to explain these results. It was inferred from the results of EIS that the conduction process in the studied ferrite materials is predominantly governed by grain boundary volume.

High arsenic concentrations and enriched sulfur and oxygen isotopes in a fractured-bedrock ground-water system

USGS Publications Warehouse

Lipfert, G.; Sidle, W.C.; Reeve, A.S.; Ayuso, R.A.; Boyce, A.J.

2007-01-01

Ground water with high arsenic concentrations (up to 26.6????mol L- 1) has sulfate enriched in 34S and 18O in the fractured-bedrock, ground-water system of the Kelly's Cove watershed, Northport, Maine, USA. The ranges of sulfur and oxygen isotope values in aqueous sulfate, ??34S[SO4] and ??18O[SO4], at the Kelly's Cove watershed are + 3.4 to + 4.9??? and - 2.0 to + 6.7???, respectively. These isotope values are strikingly similar to those of the Goose River, Maine watershed which has ??34S[SO4] and ??18O[SO4] ranges of + 3.7 to + 4.6 ??? and - 2.6 to + 7.5???, respectively. In both systems, high arsenic concentrations occur with high ??34S[SO4] and ??18O[SO4] values, yet redox conditions and underlying rock types are quite different. The isotope values of sulfide minerals, ??34S[min], from four bedrock cores vary over short distances and range from - 5.1 to + 7.5???. The ??34S[SO4] values are controlled by the ??34S[min] values with minor input of atmospheric SO4. The much narrower range in ??34S[SO4] values than ??34S[min] values is probably due to sufficient ground-water mixing at a scale greater than the ??34S[min] variability. The ??34S[SO4] values are about 2??? higher than the average ??34S[min] value and fall within the range of ??34S[min] values, indicating only minor fractionation due to bacterial reduction of SO4. The highest ??18O[SO4] values were measured in the downgradient, confined, arsenic-rich ground water. High ??18O[SO4] values there cannot be due to aeration by atmospheric oxygen, but may arise from reoxidation of reduced SO4 products. The enrichment factors of ??18O in SO4 compared to H2O, + 7.2 to + 15.5???, in the Kelly's Cove ground water and the negligible 34S enrichment is very similar to those derived from experimental data of anaerobic sulfide oxidation in the presence of Mn and Fe oxides. Sea level at the Kelly's Cove watershed was approximately 80??m above present sea level about 13 000??years before present, imposing reducing conditions on that area of the watershed. Sea level dropped approximately 60??m below present sea level about 11 000??years before present, allowing for possible oxidation of sulfide minerals and precipitation of arsenic in ferric oxyhydroxides during aeration of the ground-water system. Under present redox conditions, there is evidence that bacteria reduction of ferric oxyhydroxides releases arsenic. The fractionation of 18O in the SO4 during anaerobic oxidation of sulfide in the presence of Mn and Fe oxides and subsequent release of arsenic during Mn and Fe oxide reduction may explain the relationship between high arsenic concentrations and elevated 18O[SO4] at Kelly's Cove. ?? 2007 Elsevier B.V. All rights reserved.

SPATIAL LANDSCAPE INDICES IN A HEDONIC FRAMEWORK: AN ECOLOGICAL ECONOMICS ANALYSIS USING GIS. (R825309)

EPA Science Inventory

Abstract

This paper develops a spatial hedonic model to explain residential values in a region within a 30-mile radius of Washington DC. Hedonic models of housing or land values are commonplace, but are rarely estimated for non-urban problems and never using the type o...

SPATIAL LANDSCAPE INDICES IN A HEDONIC FRAMEWORK: AN ECOLOGICAL ECONOMICS ANALYSIS USING GIS. (R824766)

EPA Science Inventory

Abstract

This paper develops a spatial hedonic model to explain residential values in a region within a 30-mile radius of Washington DC. Hedonic models of housing or land values are commonplace, but are rarely estimated for non-urban problems and never using the type o...

Fidelity of Implementation in a Large-Scale, Randomized, Field Trial: Identifying the Critical Components of Values Affirmation

ERIC Educational Resources Information Center

Bradley, Dominique; Crawford, Evan; Dahill-Brown, Sara E.

2015-01-01

Several studies suggest that values-affirmation can serve as a simple, yet powerful, tool for dramatically reducing achievement gaps. Because subtle variations in implementation procedures may explain some of the variation in these findings, it is crucial for researchers to measure the fidelity with which interventions are implemented. The authors…

Creating Realistic Data Sets with Specified Properties via Simulation

ERIC Educational Resources Information Center

Goldman, Robert N.; McKenzie, John D. Jr.

2009-01-01

We explain how to simulate both univariate and bivariate raw data sets having specified values for common summary statistics. The first example illustrates how to "construct" a data set having prescribed values for the mean and the standard deviation--for a one-sample t test with a specified outcome. The second shows how to create a bivariate data…

30 CFR 206.103 - How do I value oil that is not sold under an arm's-length contract?

Code of Federal Regulations, 2010 CFR

2010-07-01

... arm's-length contract? 206.103 Section 206.103 Mineral Resources MINERALS MANAGEMENT SERVICE... oil that is not sold under an arm's-length contract? This section explains how to value oil that you... average of the gross proceeds accruing to the seller under your or your affiliates' arm's-length contracts...

Against All Odds? The Enduring Value of Liberal Education in Universities, Professions, and the Labour Market.

ERIC Educational Resources Information Center

Axelrod, Paul; Anisef, Paul; Lin, Zeng

2001-01-01

Asserting that liberal education is at risk in Canadian universities, attempts to explain why such policy shifts are occurring; points to the continuing cultural, social, and intellectual value of liberal education; and, drawing from recent census data, demonstrates that liberal education produces generally positive economic benefits to the…

Sense of place: Mount Desert Island residents and Acadia National Park

Treesearch

Nicole L. Ballinger; Robert E. Manning

1998-01-01

The framework of sense of place, developed by humanistic geographers, has been employed by researchers in their efforts to explain the range of attachments, values, and meanings assigned to natural areas. This study used an exploratory approach to address the range of values and meanings assigned by local residents to places in Acadia National Park. Qualitative...

High pCO2-induced exopolysaccharide-rich ballasted aggregates of planktonic cyanobacteria could explain Paleoproterozoic carbon burial.

PubMed

Kamennaya, Nina A; Zemla, Marcin; Mahoney, Laura; Chen, Liang; Holman, Elizabeth; Holman, Hoi-Ying; Auer, Manfred; Ajo-Franklin, Caroline M; Jansson, Christer

2018-05-29

The contribution of planktonic cyanobacteria to burial of organic carbon in deep-sea sediments before the emergence of eukaryotic predators ~1.5 Ga has been considered negligible owing to the slow sinking speed of their small cells. However, global, highly positive excursion in carbon isotope values of inorganic carbonates ~2.22-2.06 Ga implies massive organic matter burial that had to be linked to oceanic cyanobacteria. Here to elucidate that link, we experiment with unicellular planktonic cyanobacteria acclimated to high partial CO 2 pressure (pCO 2 ) representative of the early Paleoproterozoic. We find that high pCO 2 boosts generation of acidic extracellular polysaccharides (EPS) that adsorb Ca and Mg cations, support mineralization, and aggregate cells to form ballasted particles. The down flux of such self-assembled cyanobacterial aggregates would decouple the oxygenic photosynthesis from oxidative respiration at the ocean scale, drive export of organic matter from surface to deep ocean and sustain oxygenation of the planetary surface.

Optical and electrical properties of heavily indium-doped CdS around the semiconductor-metal phase transition

NASA Astrophysics Data System (ADS)

Broser, I.; Broser, R.; Birkicht, E.

1990-04-01

Heavily indium-doped CdS crystals are studied by comparing their optical and electrical properties. It is shown that in the near infrared spectral region for highly conducting crystals the correlation of electrical conductivity and optical effects can still be understood in the frame of the classical Drude-Lorentz model. Even for high doping the relaxation time τ and the effective mass m ∗ of the electrons are not markedly different from the room temperature values of "pure" crystals. At photon energies near the band gap, however, optical spectra in transmission, reflectivity, and emission show clearly the existence of band-tails and screening effects. A different situation holds for a highly compensated specimen: They are in a wide temperature region highly isolating, show activated photoconductivity and special structures in the optical spectra near the band gap. Their properties can be explained by assuming a meandering bandbending due to the combined action of donors and acceptors and the assumption of spatially isolated electron and hole droplets [6].

Intrinsic fluctuations of the proton saturation momentum scale in high multiplicity p+p collisions

DOE PAGES

McLerran, Larry; Tribedy, Prithwish

2015-11-02

High multiplicity events in p+p collisions are studied using the theory of the Color Glass Condensate. Here, we show that intrinsic fluctuations of the proton saturation momentum scale are needed in addition to the sub-nucleonic color charge fluctuations to explain the very high multiplicity tail of distributions in p+p collisions. It is presumed that the origin of such intrinsic fluctuations is non-perturbative in nature. Classical Yang Mills simulations using the IP-Glasma model are performed to make quantitative estimations. Furthermore, we find that fluctuations as large as O(1) of the average values of the saturation momentum scale can lead to raremore » high multiplicity events seen in p+p data at RHIC and LHC energies. Using the available data on multiplicity distributions we try to constrain the distribution of the proton saturation momentum scale and make predictions for the multiplicity distribution in 13 TeV p+p collisions.« less

The energy and protein value of wheat, maize and blend DDGS for cattle and evaluation of prediction methods.

PubMed

De Boever, J L; Blok, M C; Millet, S; Vanacker, J; De Campeneere, S

2014-11-01

The chemical composition inclusive amino acids (AAs) and the energy and protein value of three wheat, three maize and seven blend (mainly wheat) dried distillers grains and solubles (DDGS) were determined. The net energy for lactation (NEL) was derived from digestion coefficients obtained with sheep. The digestible protein in the intestines (DVE) and the degraded protein balance (OEB) were determined by nylon bag incubations in the rumen and the intestines of cannulated cows. Additional chemical parameters like acid-detergent insoluble CP (ADICP), protein solubility in water, in borate-phosphate buffer and in pepsin-HCl, in vitro digestibility (cellulase, protease, rumen fluid) and colour scores (L*, a*, b*) were evaluated as potential predictors of the energy and protein value. Compared to wheat DDGS (WDDGS), maize DDGS (MDDGS) had a higher NEL-value (8.49 v. 7.38 MJ/kg DM), a higher DVE-content (216 v. 198 g/kg DM) and a lower OEB-value (14 v. 66 g/kg DM). The higher energy value of MDDGS was mainly due to the higher crude fat (CFA) content (145 v. 76 g/kg DM) and also to better digestible cell-walls, whereas the higher protein value was mainly due to the higher percentage of rumen bypass protein (RBP: 69.8 v. 55.6%). The NEL-value of blend DDGS (BDDGS) was in between that of the pure DDGS-types, whereas its DVE-value was similar to MDDGS. Although lower in CP and total AAs, MDDGS provided a similar amount of essential AAs as the other DDGS-types. Lysine content was most reduced in the production of WDDGS and cysteine in MDDGS. Fat content explained 68.6% of the variation in NEL, with hemicellulose and crude ash as extra explaining variables. The best predictor for RBP as well as for OEB was the protein solubility in pepsin-HCl (R 2=77.3% and 83.5%). Intestinal digestibility of RBP could best be predicted by ADF (R 3=73.6%) and the combination of CFA and NDF could explain 60.2% of the variation in the content of absorbable microbial protein. The availability of AAs could accurately be predicted from the rumen bypass and intestinal digestibility of CP.

A discriminative test among the different theories proposed to explain the origin of the genetic code: the coevolution theory finds additional support.

PubMed

Giulio, Massimo Di

2018-05-19

A discriminative statistical test among the different theories proposed to explain the origin of the genetic code is presented. Gathering the amino acids into polarity and biosynthetic classes that are the first expression of the physicochemical theory of the origin of the genetic code and the second expression of the coevolution theory, these classes are utilized in the Fisher's exact test to establish their significance within the genetic code table. Linking to the rows and columns of the genetic code of probabilities that express the statistical significance of these classes, I have finally been in the condition to be able to calculate a χ value to link to both the physicochemical theory and to the coevolution theory that would express the corroboration level referred to these theories. The comparison between these two χ values showed that the coevolution theory is able to explain - in this strictly empirical analysis - the origin of the genetic code better than that of the physicochemical theory. Copyright © 2018 Elsevier B.V. All rights reserved.

Long-term evolution of Oort Cloud comets: capture of comets

NASA Astrophysics Data System (ADS)

Nurmi, P.; Valtonen, M. J.; Zheng, J. Q.; Rickman, H.

2002-07-01

We test different possibilities for the origin of short-period comets captured from the Oort Cloud. We use an efficient Monte Carlo simulation method that takes into account non-gravitational forces, Galactic perturbations, observational selection effects, physical evolution and tidal splittings of comets. We confirm previous results and conclude that the Jupiter family comets cannot originate in the spherically distributed Oort Cloud, since there is no physically possible model of how these comets can be captured from the Oort Cloud flux and produce the observed inclination and Tisserand constant distributions. The extended model of the Oort Cloud predicted by the planetesimal theory consisting of a non-randomly distributed inner core and a classical Oort Cloud also cannot explain the observed distributions of Jupiter family comets. The number of comets captured from the outer region of the Solar system are too high compared with the observations if the inclination distribution of Jupiter family comets is matched with the observed distribution. It is very likely that the Halley-type comets are captured mainly from the classical Oort Cloud, since the distributions in inclination and Tisserand value can be fitted to the observed distributions with very high confidence. Also the expected number of comets is in agreement with the observations when physical evolution of the comets is included. However, the solution is not unique, and other more complicated models can also explain the observed properties of Halley-type comets. The existence of Jupiter family comets can be explained only if they are captured from the extended disc of comets with semimajor axes of the comets a<5000au. The original flattened distribution of comets is conserved as the cometary orbits evolve from the outer Solar system era to the observed region.