Autosomal dominant hypocalcemia with Bartter syndrome due to a novel activating mutation of calcium sensing receptor, Y829C

PubMed Central

Choi, Keun Hee; Yang, Sei Won; Cheong, Hae Il

2015-01-01

The calcium sensing receptor (CaSR) plays an important role in calcium homeostasis. Activating mutations of CaSR cause autosomal dominant hypocalcemia by affecting parathyroid hormone secretion in parathyroid gland and calcium resorption in kidney. They can also cause a type 5 Bartter syndrome by inhibiting the apical potassium channel in the thick ascending limb of the loop of Henle in the kidney. This study presents a patient who had autosomal dominant hypocalcemia with Bartter syndrome due to an activating mutation Y829C in the transmembrane domain of the CaSR. Symptoms of hypocalcemia occurred 12 days after birth and medication was started immediately. Medullary nephrocalcinosis and basal ganglia calcification were found at 7 years old and at 17 years old. Three hypercalcemic episodes occurred, one at 14 years old and two at 17 years old. The Bartter syndrome was not severe while the serum calcium concentration was controlled, but during hypercalcemic periods, the symptoms of Bartter syndrome were aggravated. PMID:25932037

Airborne Carbon Dioxide Laser Absorption Spectrometer for IPDA Measurements of Tropospheric CO2: Recent Results

NASA Technical Reports Server (NTRS)

Spiers, Gary D.; Menzies, Robert T.

2008-01-01

The National Research Council's decadal survey on Earth Science and Applications from Space[1] recommended the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission for launch in 2013-2016 as a logical follow-on to the Orbiting Carbon Observatory (OCO) which is scheduled for launch in late 2008 [2]. The use of a laser absorption measurement technique provides the required ability to make day and night measurements of CO2 over all latitudes and seasons. As a demonstrator for an approach to meeting the instrument needs for the ASCENDS mission we have developed the airborne Carbon Dioxide Laser Absorption Spectrometer (CO2LAS) which uses the Integrated Path Differential Absorption (IPDA) Spectrometer [3] technique operating in the 2 micron wavelength region.. During 2006 a short engineering checkout flight of the CO2LAS was conducted and the results presented previously [4]. Several short flight campaigns were conducted during 2007 and we report results from these campaigns.

Ascending and Descending in Virtual Reality: Simple and Safe System Using Passive Haptics.

PubMed

Nagao, Ryohei; Matsumoto, Keigo; Narumi, Takuji; Tanikawa, Tomohiro; Hirose, Michitaka

2018-04-01

This paper presents a novel interactive system that provides users with virtual reality (VR) experiences, wherein users feel as if they are ascending/descending stairs through passive haptic feedback. The passive haptic stimuli are provided by small bumps under the feet of users; these stimuli are provided to represent the edges of the stairs in the virtual environment. The visual stimuli of the stairs and shoes, provided by head-mounted displays, evoke a visuo-haptic interaction that modifies a user's perception of the floor shape. Our system enables users to experience all types of stairs, such as half-turn and spiral stairs, in a VR setting. We conducted a preliminary user study and two experiments to evaluate the proposed technique. The preliminary user study investigated the effectiveness of the basic idea associated with the proposed technique for the case of a user ascending stairs. The results demonstrated that the passive haptic feedback produced by the small bumps enhanced the user's feeling of presence and sense of ascending. We subsequently performed an experiment to investigate an improved viewpoint manipulation method and the interaction of the manipulation and haptics for both the ascending and descending cases. The experimental results demonstrated that the participants had a feeling of presence and felt a steep stair gradient under the condition of haptic feedback and viewpoint manipulation based on the characteristics of actual stair walking data. However, these results also indicated that the proposed system may not be as effective in providing a sense of descending stairs without an optimization of the haptic stimuli. We then redesigned the shape of the small bumps, and evaluated the design in a second experiment. The results indicated that the best shape to present haptic stimuli is a right triangle cross section in both the ascending and descending cases. Although it is necessary to install small protrusions in the determined direction, by using this optimized shape the users feeling of presence of the stairs and the sensation of walking up and down was enhanced.

Resveratrol increases nitric oxide production in the rat thick ascending limb via Ca2+/calmodulin.

PubMed

Gonzalez-Vicente, Agustin; Cabral, Pablo D; Garvin, Jeffrey L

2014-01-01

The thick ascending limb of the loop of Henle reabsorbs 30% of the NaCl filtered through the glomerulus. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl absorption by this segment. Resveratrol, a polyphenol, has beneficial cardiovascular and renal effects, many of which are mediated by NO. Resveratrol increases intracellular Ca2+ (Cai) and AMP kinase (AMPK) and NAD-dependent deacetylase sirtuin1 (SIRT1) activities, all of which could activate NO production. We hypothesized that resveratrol stimulates NO production by thick ascending limbs via a Ca2+/calmodulin-dependent mechanism. To test this, the effect of resveratrol on NO bioavailability was measured in thick ascending limb suspensions. Cai was measured in single perfused thick ascending limbs. SIRT1 activity and expression were measured in thick ascending limb lysates. Resveratrol (100 µM) increased NO bioavailability in thick ascending limb suspensions by 1.3±0.2 AFU/mg/min (p<0.03). The NOS inhibitor L-NAME blunted resveratrol-stimulated NO bioavailability by 96±11% (p<0.03). The superoxide scavenger tempol had no effect. Resveratrol elevated Cai from 48±7 to 135±24 nM (p<0.01) in single tubules. In Ca2+-free media, the resveratrol-induced increase in NO was blunted by 60±20% (p<0.05) and the rise in Cai reduced by 80%. Calmodulin inhibition prevented the resveratrol-induced increase in NO (p<0.002). AMPK inhibition had no effect. Resveratrol did not increase SIRT1 activity. We conclude that resveratrol increases NO production in thick ascending limbs via a Ca2+/calmodulin dependent mechanism, and SIRT1 and AMPK do not participate. Resveratrol-stimulated NO production in thick ascending limbs may account for part of its beneficial effects.

Carbon Flux Signal Detection for the ASCENDS mission

NASA Astrophysics Data System (ADS)

Hammerling, D.; Michalak, A. M.; Kawa, S. R.; Doney, S. C.; Schaefer, K. M.

2012-12-01

Emerging satellite observations of carbon dioxide (CO2) offer novel and distinctive opportunities for quantifying the carbon cycle, which is an important scientific and societal challenge with anthropogenic CO2 emissions and accumulation rates in the atmosphere still on the rise. One mission in the planning stage is the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission, which is a laser CO2 sensing mission with an anticipated launch date around 2022. Notable features of this mission include the ability to sample at night and at high latitudes, which passive missions cannot do because of their reliance on reflected sunlight. In this work we present findings from signal detection studies, i.e. experiments that investigate if perturbations in carbon fluxes can be detected in the ASCENDS observations of atmospheric CO2 concentrations. The experiments employ a realistic synthetic-data setup using the PCTM/GEOS-5/CASA GFED CO2 flux and transport model in combination with CALIPSO and MODIS measurements. The signal detection approach applied uses a geostatistical mapping methodology that can leverage the information content of nearby observations, thereby potentially facilitating enhanced signal detection. The specific perturbation scenarios investigated are: carbon release from the melting of permafrost in the high Northern latitudes, the shifting of fossil fuel emissions from Europe to P.R. China, and natural variability in the CO2 fluxes in the Southern Ocean. Results indicate that the permafrost carbon release is comparatively easy to detect, while the Southern Ocean change is more challenging. The ability to detect a shift in fossil fuel emissions strongly depends on its magnitude: a 50% decrease in Europe is easily detectible, while a 20% decrease is only marginally so. A key conclusion is that the optimal signal detection strategy is intrinsically linked to how the carbon flux perturbations translate into atmospheric CO2 concentrations, which varies significantly among the investigated scenarios.

Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

NASA Technical Reports Server (NTRS)

Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jianping; Kawa, Stephen R.; Weaver, Clark J.

2010-01-01

We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

Atmospheric Airborne Pressure Measurements Using the Oxygen A Band for the ASCENDS Mission

NASA Technical Reports Server (NTRS)

Riris, Haris; Rodriguez, Mike; Stephen, Mark; Hasselbrack, William; Allan, Graham; Mao, Jiamping,; Kawa, Stephan R.; Weaver, Clark J.

2011-01-01

We report on airborne atmospheric pressure measurements using new fiber-based laser technology and the oxygen A-band at 765 nm. Remote measurements of atmospheric temperature and pressure are required for a number of NASA Earth science missions and specifically for the Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve predictions on any future climate change. The ultimate goal of a CO2 remote sensing mission, such as ASCENDS, is to derive the CO2 concentration in the atmosphere in terms of mole fraction in unit of parts-per-million (ppmv) with regard to dry air. Therefore, both CO2 and the dry air number of molecules in the atmosphere are needed in deriving this quantity. O2 is a stable molecule and uniformly mixed in the atmosphere. Measuring the O2 absorption in the atmosphere can thus be used to infer the dry air number of molecules and then used to calculate CO2 concentration. With the knowledge of atmospheric water vapor, we can then estimate the total surface pressure needed for CO2 retrievals. Our work, funded by the ESTO IIP program, uses fiber optic technology and non-linear optics to generate 765 nm laser radiation coincident with the Oxygen A-band. Our pulsed, time gated technique uses several on- and off-line wavelengths tuned to the O2 absorption line. The choice of wavelengths allows us to measure the pressure by using two adjacent O2 absorptions in the Oxygen A-band. Our retrieval algorithm fits the O2 lineshapes and derives the pressure. Our measurements compare favorably with a local weather monitor mounted outside our laboratory and a local weather station.

Low SWaP Semiconductor Laser Transmitter Modules For ASCENDS Mission Applications

NASA Technical Reports Server (NTRS)

Prasad, Narasimha S.; Rosiewicz, Alex; Coleman, Steven M.

2012-01-01

The National Research Council's (NRC) Decadal Survey (DS) of Earth Science and Applications from Space has identified the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as an important atmospheric science mission. NASA Langley Research Center, working with its partners, is developing fiber laser architecture based intensity modulated CW laser absorption spectrometer for measuring XCO2 in the 1571 nm spectral band. In support of this measurement, remote sensing of O2 in the 1260 nm spectral band for surface pressure measurements is also being developed. In this paper, we will present recent progress made in the development of advanced transmitter modules for CO2 and O2 sensing. Advanced DFB seed laser modules incorporating low-noise variable laser bias current supply and low-noise variable temperature control circuit have been developed. The 1571 nm modules operate at >80 mW and could be tuned continuously over the wavelength range of 1569-1574nm at a rate of 2 pm/mV. Fine tuning was demonstrated by adjusting the laser drive at a rate of 0.7 pm/mV. Heterodyne linewidth measurements have been performed showing linewidth 200 kHz and frequency jitter 75 MHz. In the case of 1260 nm DFB laser modules, we have shown continuous tuning over a range of 1261.4 - 1262.6 nm by changing chip operating temperature and 1261.0 - 1262.0 nm by changing the laser diode drive level. In addition, we have created a new laser package configuration which has been shown to improve the TEC coefficient of performance by a factor of 5 and improved the overall efficiency of the laser module by a factor of 2.

Technology Advancement for Active Remote Sensing of Carbon Dioxide from Space Using the ASCENDS CarbonHawk Experiment Simulator: First Results

NASA Technical Reports Server (NTRS)

Obland, Michael D.; Nehrir, Amin R.; Lin, Bing; Harrison, F. Wallace; Kooi, Susan; Choi, Yonghoon; Plant, James; Yang, Melissa; Antill, Charles; Campbell, Joel;

Lidar Observations of Atmospheric CO2 Column During 2014 Summer Flight Campaigns

NASA Technical Reports Server (NTRS)

Lin, Bing; Harrison, F. Wallace; Fan, Tai-Fang

2015-01-01

Advanced knowledge in atmospheric CO2 is critical in reducing large uncertainties in predictions of the Earth' future climate. Thus, Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) from space was recommended by the U.S. National Research Council to NASA. As part of the preparation for the ASCENDS mission, NASA Langley Research Center (LaRC) and Exelis, Inc. have been collaborating in development and demonstration of the Intensity-Modulated Continuous-Wave (IM-CW) lidar approach for measuring atmospheric CO2 column from space. Airborne laser absorption lidars such as the Multi-Functional Fiber Laser Lidar (MFLL) and ASCENDS CarbonHawk Experiment Simulator (ACES) operating in the 1.57 micron CO2 absorption band have been developed and tested to obtain precise atmospheric CO2 column measurements using integrated path differential absorption technique and to evaluate the potential of the space ASCENDS mission. This presentation reports the results of our lidar atmospheric CO2 column measurements from 2014 summer flight campaign. Analysis shows that for the 27 Aug OCO-2 under flight over northern California forest regions, significant variations of CO2 column approximately 2 ppm) in the lower troposphere have been observed, which may be a challenge for space measurements owing to complicated topographic condition, heterogeneity of surface reflection and difference in vegetation evapotranspiration. Compared to the observed 2011 summer CO2 drawdown (about 8 ppm) over mid-west, 2014 summer drawdown in the same region measured was much weak (approximately 3 ppm). The observed drawdown difference could be the results of the changes in both meteorological states and the phases of growing seasons. Individual lidar CO2 column measurements of 0.1-s integration were within 1-2 ppm of the CO2 estimates obtained from on-board in-situ sensors. For weak surface reflection conditions such as ocean surfaces, the 1- s integrated signal-to-noise ratio (SNR) of lidar measurements at 11 km altitude reached 376, which was equivalent to a 10-s CO2 error 0.33 ppm. For the entire processed 2014 summer flight campaign data, the mean differences between lidar remote sensed and in-situ estimated CO2 values were about -0.013 ppm. These results indicate that current laser absorption lidar approach could meet space measurement requirements for CO2 science goals.

Resveratrol Increases Nitric Oxide Production in the Rat Thick Ascending Limb via Ca2+/Calmodulin

PubMed Central

Gonzalez-Vicente, Agustin; Cabral, Pablo D.; Garvin, Jeffrey L.

2014-01-01

The thick ascending limb of the loop of Henle reabsorbs 30% of the NaCl filtered through the glomerulus. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl absorption by this segment. Resveratrol, a polyphenol, has beneficial cardiovascular and renal effects, many of which are mediated by NO. Resveratrol increases intracellular Ca2+ (Cai) and AMP kinase (AMPK) and NAD-dependent deacetylase sirtuin1 (SIRT1) activities, all of which could activate NO production. We hypothesized that resveratrol stimulates NO production by thick ascending limbs via a Ca2+/calmodulin-dependent mechanism. To test this, the effect of resveratrol on NO bioavailability was measured in thick ascending limb suspensions. Cai was measured in single perfused thick ascending limbs. SIRT1 activity and expression were measured in thick ascending limb lysates. Resveratrol (100 µM) increased NO bioavailability in thick ascending limb suspensions by 1.3±0.2 AFU/mg/min (p<0.03). The NOS inhibitor L-NAME blunted resveratrol-stimulated NO bioavailability by 96±11% (p<0.03). The superoxide scavenger tempol had no effect. Resveratrol elevated Cai from 48±7 to 135±24 nM (p<0.01) in single tubules. In Ca2+-free media, the resveratrol-induced increase in NO was blunted by 60±20% (p<0.05) and the rise in Cai reduced by 80%. Calmodulin inhibition prevented the resveratrol-induced increase in NO (p<0.002). AMPK inhibition had no effect. Resveratrol did not increase SIRT1 activity. We conclude that resveratrol increases NO production in thick ascending limbs via a Ca2+/calmodulin dependent mechanism, and SIRT1 and AMPK do not participate. Resveratrol-stimulated NO production in thick ascending limbs may account for part of its beneficial effects. PMID:25314136

Bacterial Hyaluronidase Promotes Ascending GBS Infection and Preterm Birth.

PubMed

Vornhagen, Jay; Quach, Phoenicia; Boldenow, Erica; Merillat, Sean; Whidbey, Christopher; Ngo, Lisa Y; Adams Waldorf, K M; Rajagopal, Lakshmi

2016-06-28

Preterm birth increases the risk of adverse birth outcomes and is the leading cause of neonatal mortality. A significant cause of preterm birth is in utero infection with vaginal microorganisms. These vaginal microorganisms are often recovered from the amniotic fluid of preterm birth cases. A vaginal microorganism frequently associated with preterm birth is group B streptococcus (GBS), or Streptococcus agalactiae However, the molecular mechanisms underlying GBS ascension are poorly understood. Here, we describe the role of the GBS hyaluronidase in ascending infection and preterm birth. We show that clinical GBS strains associated with preterm labor or neonatal infections have increased hyaluronidase activity compared to commensal strains obtained from rectovaginal swabs of healthy women. Using a murine model of ascending infection, we show that hyaluronidase activity was associated with increased ascending GBS infection, preterm birth, and fetal demise. Interestingly, hyaluronidase activity reduced uterine inflammation but did not impact placental or fetal inflammation. Our study shows that hyaluronidase activity enables GBS to subvert uterine immune responses, leading to increased rates of ascending infection and preterm birth. These findings have important implications for the development of therapies to prevent in utero infection and preterm birth. GBS are a family of bacteria that frequently colonize the vagina of pregnant women. In some cases, GBS ascend from the vagina into the uterine space, leading to fetal injury and preterm birth. Unfortunately, little is known about the mechanisms underlying ascending GBS infection. In this study, we show that a GBS virulence factor, HylB, shows higher activity in strains isolated from cases of preterm birth than those isolates from rectovaginal swabs of healthy women. We discovered that GBS rely on HylB to avoid immune detection in uterine tissue, but not placental tissue, which leads to increased rates of fetal injury and preterm birth. These studies provide novel insight into the underlying mechanisms of ascending infection. Copyright © 2016 Vornhagen et al.

Bacterial Hyaluronidase Promotes Ascending GBS Infection and Preterm Birth

PubMed Central

Vornhagen, Jay; Quach, Phoenicia; Boldenow, Erica; Merillat, Sean; Whidbey, Christopher; Ngo, Lisa Y.; Adams Waldorf, K. M.

2016-01-01

ABSTRACT Preterm birth increases the risk of adverse birth outcomes and is the leading cause of neonatal mortality. A significant cause of preterm birth is in utero infection with vaginal microorganisms. These vaginal microorganisms are often recovered from the amniotic fluid of preterm birth cases. A vaginal microorganism frequently associated with preterm birth is group B streptococcus (GBS), or Streptococcus agalactiae. However, the molecular mechanisms underlying GBS ascension are poorly understood. Here, we describe the role of the GBS hyaluronidase in ascending infection and preterm birth. We show that clinical GBS strains associated with preterm labor or neonatal infections have increased hyaluronidase activity compared to commensal strains obtained from rectovaginal swabs of healthy women. Using a murine model of ascending infection, we show that hyaluronidase activity was associated with increased ascending GBS infection, preterm birth, and fetal demise. Interestingly, hyaluronidase activity reduced uterine inflammation but did not impact placental or fetal inflammation. Our study shows that hyaluronidase activity enables GBS to subvert uterine immune responses, leading to increased rates of ascending infection and preterm birth. These findings have important implications for the development of therapies to prevent in utero infection and preterm birth. PMID:27353757

The Effects on Muscle Activation of Flatfoot during Gait According to the Velocity on an Ascending Slope.

PubMed

Lee, Chang-Ryeol; Kim, Myoung-Kwon

2014-05-01

[Purpose] This study determined the difference between flatfeet and normal feet in humans on an ascending slope using electromyography (EMG). [Subjects] This study was conducted on 30 adults having normal feet (n=15) and flatfeet (n=15), all of whom were 21 to 30 years old. [Methods] A treadmill (AC5000M, SCIFIT,) was used to analyze kinematic features during gait. These features were analyzed at slow, normal, and fast gait velocities on an ascending slope. A surface electromyogram (TeleMyo 2400T, Noraxon Co., USA) was used to measure muscle activity changes. [Results] The activities of most muscles in the subjects with flatfeet were significantly different from the muscle activities in the subjects with normal feet at different gait velocities on an ascending slope. There were significant differences in the vastus medialis and abductor hallucis muscles. [Conclusion] Because muscle activation of the vastus medialis in relation to stability of the lower extremity has a tendency to increase with an increase in gait velocity on an ascending slope, we hypothesized that higher impact transfer to the knee joints occurs in subjects with flatfeet due to the lack of a medial longitudinal arch and that the abductor halluces muscles, which provide dynamic stability to the medial longitudinal arches, do not activate well when they are needed in subjects with flatfeet.

Aneurysmal subarachnoid hemorrhage causes injury of the ascending reticular activating system: relation to consciousness.

PubMed

Jang, S H; Kim, H S

2015-04-01

Little is known about the pathogenetic mechanism of impaired consciousness following subarachnoid hemorrhage. Using diffusion tensor imaging, we attempted to investigate the presence of injury of the lower portion of the ascending reticular activating system between the pontine reticular formation and the intralaminar thalamic nuclei, and the relation between this injury and consciousness level in patients with SAH. We recruited 24 consecutive patients with spontaneous SAH following aneurysmal rupture and 21 healthy control subjects. Consciousness level was rated by using the Glasgow Coma Scale. Using diffusion tensor tractography, we reconstructed the lower portion of the ascending reticular activating system between the pontine reticular formation and the intralaminar thalamic nuclei. Values of fractional anisotropy, apparent diffusion coefficient, and tract number of the ascending reticular activating system were measured. A significant difference in the tract number was observed between the patient and control groups (P < .05); however, there was no significant difference in terms of fractional anisotropy and apparent diffusion coefficient values (P > .05). In addition, regarding the tract number of the patient group, the Glasgow Coma Scale showed strong positive correlations with the tract number on the more affected side (r = 0.890, P < .05), the less affected side (r = 0.798, P < .05), and both sides (r = 0.919, P < .05), respectively. We found injury of the lower portion of the ascending reticular activating system between the pontine reticular formation and the thalamus in patients with SAH. In addition, we observed a close association between injury of the lower portion of the ascending reticular activating system and impaired consciousness in patients with SAH. © 2015 by American Journal of Neuroradiology.

Development of a Coherent Differential Absorption Lidar for Range Resolved Atmospheric CO2 Measurements

NASA Technical Reports Server (NTRS)

Yu, Jirong; Petros, Mulgueta; Chen, Songsheng; Bai, Yingxin; Petzar, Paul J.; Trieu, Bo. C.; Koch, Grady J.; Beyon, Jeffery J.; Singh, Upendra N.

2010-01-01

A pulsed, 2-m coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument will measure atmospheric CO2 profiles (by DIAL) initially from a ground platform, and then be prepared for aircraft installation to measure the atmospheric CO2 column densities in the atmospheric boundary layer (ABL) and lower troposphere. The airborne prototype CO2 lidar can measure atmospheric CO2 column density in a range bin of 1km with better than 1.5% precision at horizontal resolution of less than 50km. It can provide the image of the pooling of CO2 in lowlying areas and performs nighttime mass balance measurements at landscape scale. This sensor is unique in its capability to study the vertical ABL-free troposphere exchange of CO2 directly. It will allow the investigators to pursue subsequent in science-driven deployments, and provides a unique tool for Active Sensing of CO2 Emissions over Night, Days, and Seasons (ASCENDS) validation that was strongly advocated in the recent ASCENDS Workshop.

A Novel Triple-Pulsed 2-micrometer Lidar for Simultaneous and Independent CO2 and H2O Column Measurement

NASA Technical Reports Server (NTRS)

Yu, Jirong; Singh, Upendra; Petros, Mulugeta; Refaat, Tamer

2015-01-01

The study of global warming needs precisely and accurately measuring greenhouse gases concentrations in the atmosphere. CO2 and H2O are important greenhouse gases that significantly contribute to the carbon cycle and global radiation budget on Earth. NRC Decadal Survey recommends a mission for Active Sensing of Carbon Dioxide (CO2) over Nights, Days and Seasons (ASCENDS). 2 micron laser is a viable IPDA transmitter to measure CO2 and H2O column density from space. The objective is to demonstrate a first airborne direct detection 2 micron IPDA lidar for CO2 and H2O measurements.

High-Speed On-Board Data Processing Platform for LIDAR Projects at NASA Langley Research Center

NASA Astrophysics Data System (ADS)

Beyon, J.; Ng, T. K.; Davis, M. J.; Adams, J. K.; Lin, B.

2015-12-01

The project called High-Speed On-Board Data Processing for Science Instruments (HOPS) has been funded by NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program during April, 2012 - April, 2015. HOPS is an enabler for science missions with extremely high data processing rates. In this three-year effort of HOPS, Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) and 3-D Winds were of interest in particular. As for ASCENDS, HOPS replaces time domain data processing with frequency domain processing while making the real-time on-board data processing possible. As for 3-D Winds, HOPS offers real-time high-resolution wind profiling with 4,096-point fast Fourier transform (FFT). HOPS is adaptable with quick turn-around time. Since HOPS offers reusable user-friendly computational elements, its FPGA IP Core can be modified for a shorter development period if the algorithm changes. The FPGA and memory bandwidth of HOPS is 20 GB/sec while the typical maximum processor-to-SDRAM bandwidth of the commercial radiation tolerant high-end processors is about 130-150 MB/sec. The inter-board communication bandwidth of HOPS is 4 GB/sec while the effective processor-to-cPCI bandwidth of commercial radiation tolerant high-end boards is about 50-75 MB/sec. Also, HOPS offers VHDL cores for the easy and efficient implementation of ASCENDS and 3-D Winds, and other similar algorithms. A general overview of the 3-year development of HOPS is the goal of this presentation.

High-Speed On-Board Data Processing for Science Instruments: HOPS

NASA Technical Reports Server (NTRS)

Beyon, Jeffrey

2015-01-01

The project called High-Speed On-Board Data Processing for Science Instruments (HOPS) has been funded by NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program during April, 2012 â€" April, 2015. HOPS is an enabler for science missions with extremely high data processing rates. In this three-year effort of HOPS, Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) and 3-D Winds were of interest in particular. As for ASCENDS, HOPS replaces time domain data processing with frequency domain processing while making the real-time on-board data processing possible. As for 3-D Winds, HOPS offers real-time high-resolution wind profiling with 4,096-point fast Fourier transform (FFT). HOPS is adaptable with quick turn-around time. Since HOPS offers reusable user-friendly computational elements, its FPGA IP Core can be modified for a shorter development period if the algorithm changes. The FPGA and memory bandwidth of HOPS is 20 GB/sec while the typical maximum processor-to-SDRAM bandwidth of the commercial radiation tolerant high-end processors is about 130-150 MB/sec. The inter-board communication bandwidth of HOPS is 4 GB/sec while the effective processor-to-cPCI bandwidth of commercial radiation tolerant high-end boards is about 50-75 MB/sec. Also, HOPS offers VHDL cores for the easy and efficient implementation of ASCENDS and 3-D Winds, and other similar algorithms. A general overview of the 3-year development of HOPS is the goal of this presentation.

In Vivo Patellar Tracking and Patellofemoral Cartilage Contacts during Dynamic Stair Ascending

PubMed Central

Suzuki, Takashi; Hosseini, Ali; Li, Jing-Sheng; Gill, Thomas J; Li, Guoan

2012-01-01

The knowledge of normal patellar tracking is essential for understanding of the knee joint function and for diagnosis of patellar instabilities. This paper investigated the patellar tracking and patellofemoral joint contact locations during a stair ascending activity using a validated dual-fluoroscopic imaging system. The results showed that the patellar flexion angle decreased from 41.9° to 7.5° with the knee extension during stair ascending. During first 80% of the activity, the patella shifted medially about 3.9 mm and then slightly shifted laterally during the last 20% of the ascending activity. Anterior translation of 13 mm of the patella was measured at the early 80% of the activity and then slightly moved posteriorly by about 2 mm at the last 20% of the activity. The path of the cartilage contact points was slightly lateral on the cartilage surfaces of patella and femur. On the patellar cartilage surface, the cartilage contact locations were about 2 mm laterally from heel strike to 60% of the stair ascending activity and moved laterally and reached 5.3 mm at full extension. However, the cartilage contact locations were relatively constant on the femoral cartilage surface (~5 mm lateral). The patellar tracking pattern was consistent with the patellofemoral cartilage contact location pattern. These data could provide baseline knowledge for understanding of normal physiology of the patellofemoral joint and can be used as a reference for clinical evaluation of patellofemoral disorder symptoms. PMID:22840488

Bio-chemo-mechanics of thoracic aortic aneurysms.

PubMed

Wagenseil, Jessica E

2018-03-01

Most thoracic aortic aneurysms (TAAs) occur in the ascending aorta. This review focuses on the unique bio-chemo-mechanical environment that makes the ascending aorta susceptible to TAA. The environment includes solid mechanics, fluid mechanics, cell phenotype, and extracellular matrix composition. Advances in solid mechanics include quantification of biaxial deformation and complex failure behavior of the TAA wall. Advances in fluid mechanics include imaging and modeling of hemodynamics that may lead to TAA formation. For cell phenotype, studies demonstrate changes in cell contractility that may serve to sense mechanical changes and transduce chemical signals. Studies on matrix defects highlight the multi-factorial nature of the disease. We conclude that future work should integrate the effects of bio-chemo-mechanical factors for improved TAA treatment.

A Regional CO2 Observing System Simulation Experiment for the ASCENDS Satellite Mission

NASA Technical Reports Server (NTRS)

Wang, J. S.; Kawa, S. R.; Eluszkiewicz, J.; Baker, D. F.; Mountain, M.; Henderson, J.; Nehrkorn, T.; Zaccheo, T. S.

2014-01-01

Top-down estimates of the spatiotemporal variations in emissions and uptake of CO2 will benefit from the increasing measurement density brought by recent and future additions to the suite of in situ and remote CO2 measurement platforms. In particular, the planned NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) satellite mission will provide greater coverage in cloudy regions, at high latitudes, and at night than passive satellite systems, as well as high precision and accuracy. In a novel approach to quantifying the ability of satellite column measurements to constrain CO2 fluxes, we use a portable library of footprints (surface influence functions) generated by the WRF-STILT Lagrangian transport model in a regional Bayesian synthesis inversion. The regional Lagrangian framework is well suited to make use of ASCENDS observations to constrain fluxes at high resolution, in this case at 1 degree latitude x 1 degree longitude and weekly for North America. We consider random measurement errors only, modeled as a function of mission and instrument design specifications along with realistic atmospheric and surface conditions. We find that the ASCENDS observations could potentially reduce flux uncertainties substantially at biome and finer scales. At the 1 degree x 1 degree, weekly scale, the largest uncertainty reductions, on the order of 50 percent, occur where and when there is good coverage by observations with low measurement errors and the a priori uncertainties are large. Uncertainty reductions are smaller for a 1.57 micron candidate wavelength than for a 2.05 micron wavelength, and are smaller for the higher of the two measurement error levels that we consider (1.0 ppm vs. 0.5 ppm clear-sky error at Railroad Valley, Nevada). Uncertainty reductions at the annual, biome scale range from 40 percent to 75 percent across our four instrument design cases, and from 65 percent to 85 percent for the continent as a whole. Our uncertainty reductions at various scales are substantially smaller than those from a global ASCENDS inversion on a coarser grid, demonstrating how quantitative results can depend on inversion methodology. The a posteriori flux uncertainties we obtain, ranging from 0.01 to 0.06 Pg C yr-1 across the biomes, would meet requirements for improved understanding of long-term carbon sinks suggested by a previous study.

Research activity of the greenhouse gas measurements using optical remote sensing in Japan (Invited)

NASA Astrophysics Data System (ADS)

Asai, K.

2009-12-01

Japan might be one of the most active countries dedicating themselves to studying the greenhouse gas (GHG) measurements using optical remote sensing not only on the ground but also from space. There are two reasons; one of them ascends to the Kyoto Protocol, agreed in December 1997 in Kyoto, an ancient city of Japan until 19th centuries, was designed to address the international response to serious climate change due to greenhouse gases. The other reason is due to a revision of the Basic Environment Law of Japan in order to meet the Kyoto Protocol in 1998. The State makes efforts to ensure international collaboration so as to effectively promote the monitoring, observation and measurement of the environmental situation with regard to global warming. Main activities are listed in a Table1. They are divided into two categories, i.e. the Greenhouse gases Observing SATellite (GOSAT), launched on Jan.23, 2009 and active remote sensing using lidar technology. In case of GOSAT, an initial analysis of carbon dioxide and methane concentrations was obtained for clear-sky scenes over land. In the future, after further calibration and validation of the data, observation data and corresponding analyzed products will be made available. On the other hand, studies of the laser remote sensing for measuring GHG have been actively carrying out to achieve reliable data with a higher accuracy at wavelengths of 1.6micron meter (Tokyo Metropolitan University, JAXA, Mitsubishi Electric Co.) and 2 micron meter (National Institute of Information and Communications Technology). As well-known, one of the most interests regarding atmospheric CO2 measurements is that carbon dioxide molecule measured are due to anthropological emission from fossil fuel burning or due to natural one from forest fires etc. We proposed a newly advanced CO2/CO DIAL using a hybrid of pulsed Tm,Ho:YLF and pulsed OPO pumped by it for better understanding them. Now, our effort is directed to find out the most suitable wavelength pairs to be selected.Activities of optical remote sensing for GHG in Japan

Advanced intensity-modulation continuous-wave lidar techniques for ASCENDS CO2 column measurements

NASA Astrophysics Data System (ADS)

Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. W.; Obland, Michael D.; Meadows, Byron

2015-10-01

Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

Advanced IMCW Lidar Techniques for ASCENDS CO2 Column Measurements

NASA Astrophysics Data System (ADS)

Campbell, Joel; lin, bing; nehrir, amin; harrison, fenton; obland, michael

2015-04-01

Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation.

Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for ASCENDS O2 Column Measurements

NASA Technical Reports Server (NTRS)

Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. Wallace; Obland, Michael D.; Meadows, Byron

2015-01-01

Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

A Comparison of Potential IM-CW Lidar Modulation Techniques for ASCENDS CO2 Column Measurements From Space

NASA Technical Reports Server (NTRS)

Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. Wallace; Obland, Michael D.; Ismail, Syed

2014-01-01

Global atmospheric carbon dioxide (CO2) measurements through the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) Decadal Survey recommended space mission are critical for improving our understanding of CO2 sources and sinks. IM-CW (Intensity Modulated Continuous Wave) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS science requirements. In previous laboratory and flight experiments we have successfully used linear swept frequency modulation to discriminate surface lidar returns from intermediate aerosol and cloud contamination. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate clouds, which is a requirement for the inversion of the CO2 column-mixing ratio from the instrument optical depth measurements, has been demonstrated with the linear swept frequency modulation technique. We are concurrently investigating advanced techniques to help improve the auto-correlation properties of the transmitted waveform implemented through physical hardware to make cloud rejection more robust in special restricted scenarios. Several different carrier based modulation techniques are compared including orthogonal linear swept, orthogonal non-linear swept, and Binary Phase Shift Keying (BPSK). Techniques are investigated that reduce or eliminate sidelobes. These techniques have excellent auto-correlation properties while possessing a finite bandwidth (by way of a new cyclic digital filter), which will reduce bias error in the presence of multiple scatterers. Our analyses show that the studied modulation techniques can increase the accuracy of CO2 column measurements from space. A comparison of various properties such as signal to noise ratio (SNR) and time-bandwidth product are discussed.

Simulation Studies for a Space-Based CO2 Lidar Mission

NASA Technical Reports Server (NTRS)

Kawa, S. R.; Mao, J.; Abshire, J. B.; Collatz, G. J.; Sun, X.; Weaver, C. J.

2010-01-01

We report results of initial space mission simulation studies for a laser-based, atmospheric CO2 sounder, which are based on real-time carbon cycle process modelling and data analysis. The mission concept corresponds to the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) recommended by the US National Academy of Sciences' Decadal Survey. As a pre-requisite for meaningful quantitative evaluation, we employ a CO2 model that has representative spatial and temporal gradients across a wide range of scales. In addition, a relatively complete description of the atmospheric and surface state is obtained from meteorological data assimilation and satellite measurements. We use radiative transfer calculations, an instrument model with representative errors and a simple retrieval approach to quantify errors in 'measured' CO2 distributions, which are a function of mission and instrument design specifications along with the atmospheric/surface state. Uncertainty estimates based on the current instrument design point indicate that a CO2 laser sounder can provide data consistent with ASCENDS requirements and will significantly enhance our ability to address carbon cycle science questions. Test of a dawn/dusk orbit deployment, however, shows that diurnal differences in CO2 column abundance, indicative of plant photosynthesis and respiration fluxes, will be difficult to detect

Real-Time On-Board Airborne Demonstration of High-Speed On-Board Data Processing for Science Instruments (HOPS)

NASA Technical Reports Server (NTRS)

Beyon, Jeffrey Y.; Ng, Tak-Kwong; Davis, Mitchell J.; Adams, James K.; Bowen, Stephen C.; Fay, James J.; Hutchinson, Mark A.

2015-01-01

The project called High-Speed On-Board Data Processing for Science Instruments (HOPS) has been funded by NASA Earth Science Technology Office (ESTO) Advanced Information Systems Technology (AIST) program since April, 2012. The HOPS team recently completed two flight campaigns during the summer of 2014 on two different aircrafts with two different science instruments. The first flight campaign was in July, 2014 based at NASA Langley Research Center (LaRC) in Hampton, VA on the NASA's HU-25 aircraft. The science instrument that flew with HOPS was Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) CarbonHawk Experiment Simulator (ACES) funded by NASA's Instrument Incubator Program (IIP). The second campaign was in August, 2014 based at NASA Armstrong Flight Research Center (AFRC) in Palmdale, CA on the NASA's DC-8 aircraft. HOPS flew with the Multifunctional Fiber Laser Lidar (MFLL) instrument developed by Excelis Inc. The goal of the campaigns was to perform an end-to-end demonstration of the capabilities of the HOPS prototype system (HOPS COTS) while running the most computationally intensive part of the ASCENDS algorithm real-time on-board. The comparison of the two flight campaigns and the results of the functionality tests of the HOPS COTS are presented in this paper.

Present day vertical deformation of Pico and Faial islands revealed by merged INSAR and GPS data

NASA Astrophysics Data System (ADS)

Catalao, Joao; Nico, Giovanni; Catita, Cristina

2010-05-01

In this paper we investigate the problem of the integration of repeated GPS geodetic measurements and interferometric Synthetic Aperture Radar (SAR) observations for the determination of high resolution vertical deformation maps. The Faial and Pico islands in the Azores archipelago were chosen as study area. These islands are characterized by a intense volcanic and seismic activity. Both islands are covered by huge vegetation and have very unstable atmospheric conditions which negatively influence the interferometric processing. In this work, we apply the advanced interferometric SAR processing based on Persistent Scatterers. However, the small number of man made structures reduces the density of Persistent Scatterers. Furthermore, the different ascending and descending acquisition geometries give different sets of Persistent Scatterers, with complementary spatial coverage, and different line-of-sight velocities. The estimated velocities are relative to the master image (different from ascending and descending) and must be referred to an absolute velocity (in the sense of referred to a geodetic reference frame). The strategy used to overcome the aforementioned problems is based on the combination of sparse GPS 3D-velocities with two sets of Persistent Scatterers determined from ascending and descending passes. The input data are: a set of GPS - 3D velocities relative to ITRF05 (18 Stations) and two sets of Persistent Scatterers corresponding to the descending and ascending orbits. A dataset of 60 interferometric repeat-pass ASAR/ENVISAT images were acquired over the Faial and Pico islands, from 2006 to 2008, along ascending and descending passes. Each interferogram obtained by this dataset was corrected for atmospheric artefacts using a Weather Forecasting model. Initially, the horizontal velocity component (east and north) is assigned to each PS from interpolation of available GPS observations. Then, the vertical component of the velocity is determined from the SAR line-of-sight velocity and the GPS horizontal velocity component. Later, the vertical velocity offsets are numerically determined by comparison between GPS (ITRF velocities) and PS (the two ascending and descending sets) measurements. These values are then used to create the vertical deformation map of Faial and Pico islands with considerably better resolution and accuracy than using a single set of observations. The vertical deformation map has identified a large continuous area of subsidence on the west of Faial island, on the flank of Capelinhos eruption cone, with a maximum subsidence range of 10 mm/yr. It has also revealed the subsidence of the summit crater of Pico island (9 mm/yr) and a large area of subsidence on the west of the island, corresponding mostly to creep movement. Key words: SAR Interferometry, GPS-INSAR integration, Volcano, subsidence

Space-based Lidar Measurements of Greenhouse Gases and Their Projected Impact on Quantification of Surface Sources and Sinks

NASA Astrophysics Data System (ADS)

Kawa, S. R.; Baker, D. F.; Chatterjee, A.; Crowell, S.

2016-12-01

The measurement of atmospheric greenhouse gases (GHG), principally CO2 and CH4, from space using active (lidar) sensing techniques has several potentially significant advantages in comparison to missions using passive instrument approaches. A great deal of progress has been made in development of the active methods since the US National Academy of Sciences (NAS) 2007 Decadal Survey recommended the ASCENDS mission (Active Sensing of Carbon Emissions, Nights, Days, and Seasons) for NASA's next generation CO2 observing system. Active GHG missions remain in consideration by the current NAS Decadal Survey for Earth Science 2017. In this presentation, we update the measurement characteristics expected for active GHG sensing, test how these measurements will enhance our ability to quantify GHG surface fluxes, and examine the potential role of active sensing to address carbon cycle issues as required for confident projection of carbon-climate interactions. Over the past decade, laser CO2 instrument concepts, retrieval approaches, and measurement techniques have matured significantly, driven by technology advances and by analysis of data from airborne simulators. Performance simulations updated to match the latest developments show substantially lower random errors, better spatial resolution, and more information content for global XCO2 data than just a few years ago. Observing System Simulation Experiments using global flux inversion models show corresponding improvements in resolving surface fluxes and reducing flux uncertainties for the expected lidar data. Simulations including prospective systematic (bias) errors, which are expected to be lesser for the lidar system compared to passive measurements, provide guidance for instrument design requirements. We will comment on the impact of errors in knowledge of the atmospheric state including the need for coincident measurements of O2 column in order to normalize the column abundances to dry air mole fraction. We will also comment on the potential impact of future active missions for CH4. The results indicate that active systems will provide GHG measurements of high quality and spatial sampling that will contribute substantially to knowledge of carbon flux distributions and their dependence on underlying physical processes in critical regions.

NADPH oxidase 4-derived superoxide mediates flow-stimulated NKCC2 activity in thick ascending limbs.

PubMed

Saez, Fara; Hong, Nancy J; Garvin, Jeffrey L

2018-05-01

Luminal flow augments Na + reabsorption in the thick ascending limb more than can be explained by increased ion delivery. This segment reabsorbs 30% of the filtered load of Na + , playing a key role in its homeostasis. Whether flow elevations enhance Na + -K + -2Cl - cotransporter (NKCC2) activity and the second messenger involved are unknown. We hypothesized that raising luminal flow augments NKCC2 activity by enhancing superoxide ([Formula: see text]) production by NADPH oxidase 4 (NOX4). NKCC2 activity was measured in thick ascending limbs perfused at either 5 or 20 nl/min with and without inhibitors of [Formula: see text] production. Raising luminal flow from 5 to 20 nl/min enhanced NKCC2 activity from 4.8 ± 0.9 to 6.3 ± 1.2 arbitrary fluorescent units (AFU)/s. Maintaining flow at 5 nl/min did not alter NKCC2 activity. The superoxide dismutase mimetic manganese (III) tetrakis (4-benzoic acid) porphyrin chloride blunted NKCC2 activity from 3.5 ± 0.4 to 2.5 ± 0.2 AFU/s when flow was 20 nl/min but not 5 nl/min. When flow was 20 nl/min, NKCC2 activity showed no change with time. The selective NOX1/4 inhibitor GKT-137831 blunted NKCC2 activity when thick ascending limbs were perfused at 20 nl/min from 7.2 ± 1.1 to 4.5 ± 0.8 AFU/s but not at 5 nl/min. The inhibitor also prevented luminal flow from elevating [Formula: see text] production. Allopurinol, a xanthine oxidase inhibitor, had no effect on NKCC2 activity when flow was 20 nl/min. Tetanus toxin prevents flow-induced stimulation of NKCC2 activity. We conclude that elevations in luminal flow enhance NaCl reabsorption in thick ascending limbs by stimulating NKCC2 via NOX4 activation and increased [Formula: see text]. NKCC2 activation is primarily the result of insertion of new transporters in the membrane.

Aortic remodeling after transverse aortic constriction in mice is attenuated with AT1 receptor blockade.

PubMed

Kuang, Shao-Qing; Geng, Liang; Prakash, Siddharth K; Cao, Jiu-Mei; Guo, Steven; Villamizar, Carlos; Kwartler, Callie S; Peters, Andrew M; Brasier, Allan R; Milewicz, Dianna M

2013-09-01

Although hypertension is the most common risk factor for thoracic aortic diseases, it is not understood how increased pressures on the ascending aorta lead to aortic aneurysms. We investigated the role of angiotensin II type 1 receptor activation in ascending aortic remodeling in response to increased biomechanical forces using a transverse aortic constriction (TAC) mouse model. Two weeks after TAC, the increased biomechanical pressures led to ascending aortic dilatation and thickening of the medial and adventitial layers of the aorta. There was significant adventitial hyperplasia and inflammatory responses in TAC ascending aortas were accompanied by increased adventitial collagen, elevated inflammatory and proliferative markers, and increased cell density attributable to accumulation of myofibroblasts and macrophages. Treatment with losartan significantly blocked TAC-induced vascular inflammation and macrophage accumulation. However, losartan only partially prevented TAC-induced adventitial hyperplasia, collagen accumulation, and ascending aortic dilatation. Increased Tgfb2 expression and phosphorylated-Smad2 staining in the medial layer of TAC ascending aortas were effectively blocked with losartan. In contrast, the increased Tgfb1 expression and adventitial phospho-Smad2 staining were only partially attenuated by losartan. In addition, losartan significantly blocked extracellular signal-regulated kinase activation and reactive oxygen species production in the TAC ascending aorta. Inhibition of the angiotensin II type 1 receptor using losartan significantly attenuated the vascular remodeling associated with TAC but did not completely block the increased transforming growth factor-β1 expression, adventitial Smad2 signaling, and collagen accumulation. These results help to delineate the aortic transforming growth factor-β signaling that is dependent and independent of the angiotensin II type 1 receptor after TAC.

[Changes of wetland landscape pattern in Dayang River Estuary based on high-resolution remote sensing image].

PubMed

Wu, Tao; Zhao, Dong-zhi; Zhang, Feng-shou; Wei, Bao-quan

2011-07-01

Based on the comprehensive consideration of the high resolution characteristics of remote sensing data and the current situation of land cover and land use in Dayang River Estuary wetland, a classification system with different resolutions of wetland landscape in the Estuary was established. The landscape pattern indices and landscape transition matrix were calculated by using the high resolution remote sensing data, and the dynamic changes of the landscape pattern from 1984 to 2008 were analyzed. In the study period, the wetland landscape components changed drastically. Wetland landscape transferred from natural wetland into artificial wetland, and wetland core regional area decreased. Natural wetland's largest patch area index descended, and the fragmentation degree ascended; while artificial wetland area expanded, its patch number decreased, polymerization degree increased, and the maximum patch area index had an obvious increasing trend. Increasing human activities, embankment construction, and reclamation for aquaculture were the main causes for the decrease of wetland area and the degradation of the ecological functions of Dayang River Estuary. To constitute long-term scientific and reasonable development plan, establish wetland nature reserves, protect riverway, draft strict inspective regimes for aquaculture reclamation, and energetically develop resource-based tourism industry would be the main strategies for the protection of the estuarine wetland.

Technology advancement for the ASCENDS mission using the ASCENDS CarbonHawk Experiment Simulator (ACES)

NASA Astrophysics Data System (ADS)

Obland, M. D.; Antill, C.; Browell, E. V.; Campbell, J. F.; CHEN, S.; Cleckner, C.; Dijoseph, M. S.; Harrison, F. W.; Ismail, S.; Lin, B.; Meadows, B. L.; Mills, C.; Nehrir, A. R.; Notari, A.; Prasad, N. S.; Kooi, S. A.; Vitullo, N.; Dobler, J. T.; Bender, J.; Blume, N.; Braun, M.; Horney, S.; McGregor, D.; Neal, M.; Shure, M.; Zaccheo, T.; Moore, B.; Crowell, S.; Rayner, P. J.; Welch, W.

2013-12-01

The ASCENDS CarbonHawk Experiment Simulator (ACES) is a NASA Langley Research Center project funded by NASA's Earth Science Technology Office that seeks to advance technologies critical to measuring atmospheric column carbon dioxide (CO2) mixing ratios in support of the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The technologies being advanced are: (1) multiple transmitter and telescope-aperture operations, (2) high-efficiency CO2 laser transmitters, (3) a high bandwidth detector and transimpedance amplifier (TIA), and (4) advanced algorithms for cloud and aerosol discrimination. The instrument architecture is being developed for ACES to operate on a high-altitude aircraft, and it will be directly scalable to meet the ASCENDS mission requirements. The above technologies are critical for developing an airborne simulator and spaceborne instrument with lower platform consumption of size, mass, and power, and with improved performance. This design employs several laser transmitters and telescope-apertures to demonstrate column CO2 retrievals with alignment of multiple laser beams in the far-field. ACES will transmit five laser beams: three from commercial lasers operating near 1.57-microns, and two from the Exelis atmospheric oxygen (O2) fiber laser amplifier system operating near 1.26-microns. The Master Oscillator Power Amplifier at 1.57-microns measures CO2 column concentrations using an Integrated-Path Differential Absorption (IPDA) lidar approach. O2 column amounts needed for calculating the CO2 mixing ratio will be retrieved using the Exelis laser system with a similar IPDA approach. The three aperture telescope design was built to meet the constraints of the Global Hawk high-altitude unmanned aerial vehicle (UAV). This assembly integrates fiber-coupled transmit collimators for all of the laser transmitters and fiber-coupled optical signals from the three telescopes to the aft optics and detector package. The detector/TIA effort has improved the existing detector subsystem by: increasing its bandwidth to 5.4 MHz, exceeding the original goal of 5 MHz; reducing the overall mass from 18 lbs to <10 lbs; and increasing the duration of autonomous, service-free operation periods from 4 hrs to >24 hrs. The new detector subsystem will permit higher laser modulation rates, which provides greater flexibility for implementing thin-cloud discrimination algorithms as well as improving range resolution and error reduction, and will enable long-range flights on the Global Hawk. The cloud/aerosol discrimination work features development of new algorithms by Langley and Exelis for the avoidance of bias errors in the retrieval of column CO2 induced by the presence of thin clouds.

An Instrument to Enable Identification of Anthropogenic CO2 Emissions Using Concurrent CO Measurements

NASA Technical Reports Server (NTRS)

Cook, William B.; Crawford, James H.; Diskin, Glenn S.; Gordley, Larry L.; Rubio, Manuel; Sachse, Glen W.

2008-01-01

We have developed an instrument concept that will enable the measurement of CO from the top of the atmosphere to the Earth's surface with very high sensitivity and at the high spatial and temporal resolutions required by the NRC Decadal Survey mission Active Sensing of Carbon Dioxide (CO2) over Nights, Days and Seasons (ASCENDS). We are developing an innovative CO sensor that will enable the ASCENDS mission to differentiate between anthropogenic and natural sources and sinks of global carbon. The NRC Decadal Survey places particular emphasis on retrieving CO information for the planetary boundary layer. Measurement made using both the 2.3 micron and 4.7 micron channels are needed to achieve the sensitivity required in the lower atmosphere where the degree of CO - CO2 correlation is indicative of anthropogenic sources of CO2. Measurements made using only the 4.7 micron channel cannot provide sufficient sensitivity to CO in the very lowest layers of the atmosphere. The fundamental method we use is Gas Filter Correlation Radiometry (GFCR), a highly successful technique used in other airborne and space-based missions for detecting trace species in the Earth's atmosphere. Our version of GFCR overcomes many of the limitations encountered by prior and existing instruments, allowing us to measure weak signals from small targets very quickly and with extremely high specificity by employing a new dual beam radiometer concept using a focal plane array. Our design will provide a means to make the desired CO measurements for the ASCENDS mission. A simple change in gas filter cell contents would allow the same hardware to measure CH4 with high precision under the nominal ASCENDS mission spatial and temporal constraints. All critical components in the sensor design are mature, many subsystems tested, and the system has been extensively modeled, bringing it to a present Technology Readiness Level (TRL) of 3 (though some individual components are at TRLs 6-9). We are presently developing critical components for the new spectrometer and advancing our understanding of the measurement requirements for both CO and CH4. This new GFCR technique/sensor will enable measurements of trace gases with high sensitivity while maintaining the inherent robustness and simplicity of the more traditional radiometer hardware. Initial estimates of cost/risk of a spacebased 2-channel GFCR indicate that our design is extremely cost effective and will fit within existing ASCENDS mission budget constraints as determined by the NRC Decadal Survey and a NASA-sponsored mission study.

Remote sensing/global change. A special bibliography

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

Not Available

1994-11-01

The first portion of this bibliography contains citations (with abstracts, when available) to unclassified literature contained in the NASA STI Database. These citations also appeared in issues of the abstract journal 'Scientific and Technical Aerospace Reports (STAR)', or in other announcement products offered by the NASA STI Program. The citations appear in ascending accession number order. A second section provides several indexes to the citations. They are subject term, personal author, report number, and accession number. The citations are included for the following disciplines as they relate to remote sensing and global change: astronautics, engineering, geosciences, life sciences, mathematical andmore » computer sciences, social sciences, and space sciences.« less

Remote sensing/global change. A special bibliography

NASA Technical Reports Server (NTRS)

1994-01-01

The first portion of this bibliography contains citations (with abstracts, when available) to unclassified literature contained in the NASA STI Database. These citations also appeared in issues of the abstract journal 'Scientific and Technical Aerospace Reports (STAR)', or in other announcement products offered by the NASA STI Program. The citations appear in ascending accession number order. A second section provides several indexes to the citations. They are subject term, personal author, report number, and accession number. The citations are included for the following disciplines as they relate to remote sensing and global change: astronautics, engineering, geosciences, life sciences, mathematical and computer sciences, social sciences, and space sciences.

The Calcium-Sensing Receptor Increases Activity of the Renal NCC through the WNK4-SPAK Pathway.

PubMed

Bazúa-Valenti, Silvana; Rojas-Vega, Lorena; Castañeda-Bueno, María; Barrera-Chimal, Jonatan; Bautista, Rocío; Cervantes-Pérez, Luz G; Vázquez, Norma; Plata, Consuelo; Murillo-de-Ozores, Adrián R; González-Mariscal, Lorenza; Ellison, David H; Riccardi, Daniela; Bobadilla, Norma A; Gamba, Gerardo

2018-05-30

Background Hypercalciuria can result from activation of the basolateral calcium-sensing receptor (CaSR), which in the thick ascending limb of Henle's loop controls Ca 2+ excretion and NaCl reabsorption in response to extracellular Ca 2+ However, the function of CaSR in the regulation of NaCl reabsorption in the distal convoluted tubule (DCT) is unknown. We hypothesized that CaSR in this location is involved in activating the thiazide-sensitive NaCl cotransporter (NCC) to prevent NaCl loss. Methods We used a combination of in vitro and in vivo models to examine the effects of CaSR on NCC activity. Because the KLHL3-WNK4-SPAK pathway is involved in regulating NaCl reabsorption in the DCT, we assessed the involvement of this pathway as well. Results Thiazide-sensitive 22 Na + uptake assays in Xenopus laevis oocytes revealed that NCC activity increased in a WNK4-dependent manner upon activation of CaSR with Gd 3+ In HEK293 cells, treatment with the calcimimetic R-568 stimulated SPAK phosphorylation only in the presence of WNK4. The WNK4 inhibitor WNK463 also prevented this effect. Furthermore, CaSR activation in HEK293 cells led to phosphorylation of KLHL3 and WNK4 and increased WNK4 abundance and activity. Finally, acute oral administration of R-568 in mice led to the phosphorylation of NCC. Conclusions Activation of CaSR can increase NCC activity via the WNK4-SPAK pathway. It is possible that activation of CaSR by Ca 2+ in the apical membrane of the DCT increases NaCl reabsorption by NCC, with the consequent, well known decrease of Ca 2+ reabsorption, further promoting hypercalciuria. Copyright © 2018 by the American Society of Nephrology.

Stress axis regulation during social ascension in a group-living cichlid fish.

PubMed

Culbert, Brett M; Gilmour, Kathleen M; Balshine, Sigal

2018-06-19

Animals living in groups often form social hierarchies, with characteristic behaviours and physiologies associated with rank. However, when social opportunities arise and a subordinate ascends into a dominant position, quick adjustments are necessary to secure this position. Such periods of social transition are typically associated with elevated glucocorticoid production, but the precise regulation of the stress axis during these occasions is not well understood. Using the group-living cichlid, Neolamprologus pulcher, the effects of social ascension on the stress axis were assessed. Ascenders rapidly filled experimentally created vacancies, adopting a dominant behavioural phenotype within 72 h-elevating aggression, activity, and workload, while receiving high rates of affiliative behaviours from their group members. Despite assuming behavioural dominance within their groups, ascenders displayed higher cortisol levels than dominants three days post-ascension. Additionally, compared to subordinates, ascenders had increased transcript abundance of steroidogenic acute regulatory protein (star) and cytochrome p450 side-chain cleavage enzyme (p450scc) in the head kidney, indicating activation of the stress axis. Cortisol levels were lowest in ascenders that displayed low rates of aggression, potentially reflecting the reestablishment of social stability in these groups. Increased transcript abundance of both glucocorticoid receptors (gr1 and gr2) in the brain's preoptic area (POA) of ascenders compared to dominants suggested an enhanced capacity for cortisol regulation via negative feedback. Our results reveal a regulatory cascade of behavioural and physiological interactions and highlight the importance of investigating the underlying mechanisms regulating the stress axis. Copyright © 2018. Published by Elsevier Inc.

Investigating the constraint imposed by column averaged PBL CO2 data within an atmospheric inversion framework

NASA Astrophysics Data System (ADS)

Schuh, A. E.; Kawa, S. R.; Denning, A. S.; Baker, D. F.; Ramanathan, A. K.

2014-12-01

It was initially hoped that the proposed Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) NASA mission could rectify diurnal fluxes through it's ability to measure during both days and nights. However, initial simulation results (Kawa et al 2010) showed limited skill at identifying diurnal differences in fluxes. We investigate the possibility of (1) supplementing ASCENDS with well chosen in-situ surface sites and/or (2) adding distinct column measurements for the PBL and free troposphere into the inversion framework to determine the impact on recovering net ecosystem exchange (NEE), as well as distinct gross primary production (GPP) and respiration fluxes. In particular, we run forward simulations and inversions with distinct respiration and GPP fluxes calculated from the SiB model (Baker et al 2008) and test the ability of an EnKF based inversion framework to recover a hypothetical tropical CO2 fertilization effect resulting in enhanced GPP. Baker, I. T.; Prihodko, L.; Denning, A. S.; Goulden, M.; Miller, S. & da Rocha, H. R. (2008), 'Seasonal drought stress in the Amazon: Reconciling 3 models and observations', Journal of Geophysical Research 113. Kawa, S. R.; MAO, J.; ABSHIRE, J. B.; J., C. G.; SUN, X. & WEAVER, C. J. (2010), 'Simulation studies for a space-based CO2 lidar mission.', Tellus B 62, 759-769.

Listening to Another Sense: Somatosensory Integration in the Auditory System

PubMed Central

Wu, Calvin; Stefanescu, Roxana A.; Martel, David T.

2014-01-01

Conventionally, sensory systems are viewed as separate entities, each with its own physiological process serving a different purpose. However, many functions require integrative inputs from multiple sensory systems, and sensory intersection and convergence occur throughout the central nervous system. The neural processes for hearing perception undergo significant modulation by the two other major sensory systems, vision and somatosensation. This synthesis occurs at every level of the ascending auditory pathway: the cochlear nucleus, inferior colliculus, medial geniculate body, and the auditory cortex. In this review, we explore the process of multisensory integration from 1) anatomical (inputs and connections), 2) physiological (cellular responses), 3) functional, and 4) pathological aspects. We focus on the convergence between auditory and somatosensory inputs in each ascending auditory station. This review highlights the intricacy of sensory processing, and offers a multisensory perspective regarding the understanding of sensory disorders. PMID:25526698

Lidar measurements of the column CO2 mixing ratio made by NASA Goddard's CO2 Sounder during the NASA ASCENDS 2014 Airborne campaign.

NASA Astrophysics Data System (ADS)

Ramanathan, A. K.; Mao, J.; Abshire, J. B.; Kawa, S. R.

2015-12-01

Remote sensing measurements of CO2 from space can help improve our understanding of the carbon cycle and help constrain the global carbon budget. However, such measurements need to be sufficiently accurate to detect small (1 ppm) changes in the CO2 mixing ratio (XCO2) against a large background (~ 400 ppm). Satellite measurements of XCO2 using passive spectrometers, such as those from the Japanese GOSAT (Greenhouse gas Observing Satellite) and the NASA OCO-2 (Orbiting Carbon Observatory-2) are limited to daytime sunlit portions of the Earth and are susceptible to biases from clouds and aerosols. For this reason, NASA commissioned the formulation study of ASCENDS a space-based lidar mission. NASA Goddard Space Flight Center's CO2 Sounder lidar is one candidate approach for the ASCENDS mission. The NASA GSFC CO2 Sounder measures the CO2 mixing ratio using a pulsed multi-wavelength integrated path differential absorption (IPDA) approach. The CO2 Sounder has flown in the 2011, 2013 and 2014 ASCENDS airborne campaigns over the continental US, and has produced measurements in close agreement with in situ measurements of the CO2 column. In 2014, the CO2 Sounder upgraded its laser with a precision step-locked diode laser source to improve the lidar wavelength position accuracy. It also improved its optical receiver with a low-noise, high efficiency, HgCdTe avalanche photo diode detector. The combination of these two technologies enabled lidar XCO2 measurements with unprecedented accuracy. In this presentation, we show analysis from the ASCENDS 2014 field campaign, exploring: (1) Horizontal XCO2 gradients measured by the lidar, (2) Comparisons of lidar XCO2 measurements against the Parameterized Chemistry Transport Model (PCTM), and (3) Lidar column water vapor measurements using a HDO absorption line that occurs next to the CO2 absorption line. This can reduce the uncertainty in the dry air column used in XCO2 retrievals.

The effects of changes in response-independent pay upon human masseter EMG. M.A. Thesis

NASA Technical Reports Server (NTRS)

Proni, T. J.

1973-01-01

Electromyographic activity of the masseter muscle was recorded in five human subjects who were presented with systematically varied rates of non-contingent pay. Rates of pay were varied between sessions in either a descending or an ascending series. The number of masseter contractions was found to be greater during the descending series than during the ascending series, especially when a descending series of pay changes followed an ascending series. Verbal physical displays of anger and aggression were noted during descending series. These data indicated a possible relation between masseter contractions and aggression.

Intensity Modulation Techniques for Continuous-Wave Lidar for Column CO2 Measurements

NASA Astrophysics Data System (ADS)

Campbell, J. F.; Lin, B.; Obland, M. D.; Kooi, S. A.; Fan, T. F.; Meadows, B.; Browell, E. V.; Erxleben, W. H.; McGregor, D.; Dobler, J. T.; Pal, S.; O'Dell, C.

2017-12-01

Global and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and the Atmospheric Carbon and Transport (ACT) - America project are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the ASCENDS and ACT-America science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) and Linear Swept Frequency modulations to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that take advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques and provides very high (at sub-meter level) range resolution. We compare BPSK to linear swept frequency and introduce a new technique to eliminate sidelobes in situations from linear swept frequency where the SNR is high with results that rival BPSK. We also investigate the effects of non-linear modulators, which can in some circumstances degrade the orthogonality of the waveforms, and show how to avoid this. These techniques are used in a new data processing architecture written in the C language to support the ASCENDS CarbonHawk Experiment Simulator (ACES) and ACT-America programs.

Regional and Global Atmospheric CO2 Measurements Using 1.57 Micron IM-CW Lidar

NASA Technical Reports Server (NTRS)

Lin, Bing; Obland, Michael; Nehrir, Amin; Browell, Edward; Harrison, F. Wallace; Dobler, Jeremy; Campbell, Joel; Kooi, Susan; Meadows, Byron; Fan, Tai-Fang;

An entrepreneurial training model to enhance undergraduate training in biomedical research.

PubMed

Kamangar, Farin; Silver, Gillian; Hohmann, Christine; Hughes-Darden, Cleo; Turner-Musa, Jocelyn; Haines, Robert Trent; Jackson, Avis; Aguila, Nelson; Sheikhattari, Payam

2017-01-01

Undergraduate students who are interested in biomedical research typically work on a faculty member's research project, conduct one distinct task (e.g., running gels), and, step by step, enhance their skills. This "apprenticeship" model has been helpful in training many distinguished scientists over the years, but it has several potential drawbacks. For example, the students have limited autonomy, and may not understand the big picture, which may result in students giving up on their goals for a research career. Also, the model is costly and may greatly depend on a single mentor. The NIH Building Infrastructure Leading to Diversity (BUILD) Initiative has been established to fund innovative undergraduate research training programs and support institutional and faculty development of the recipient university. The training model at Morgan State University (MSU), namely " A S tudent- C entered En trepreneurship D evelopment training model" (ASCEND), is one of the 10 NIH BUILD-funded programs, and offers a novel, experimental "entrepreneurial" training approach. In the ASCEND training model, the students take the lead. They own the research, understand the big picture, and experience the entire scope of the research process, which we hypothesize will lead to a greater sense of self-efficacy and research competency, as well as an enhanced sense of science identity. They are also immersed in environments with substantial peer support, where they can exchange research ideas and share experiences. This is important for underrepresented minority students who might have fewer role models and less peer support in conducting research. In this article, we describe the MSU ASCEND entrepreneurial training model's components, rationale, and history, and how it may enhance undergraduate training in biomedical research that may be of benefit to other institutions. We also discuss evaluation methods, possible sustainability solutions, and programmatic challenges that can affect all types of science training interventions.

Activation of the Ca2+-sensing receptor increases renal claudin-14 expression and urinary Ca2+ excretion

PubMed Central

Dimke, Henrik; Desai, Prajakta; Borovac, Jelena; Lau, Alyssa; Pan, Wanling; Alexander, R. Todd

2016-01-01

Kidney stones are a prevalent clinical condition imposing a large economic burden on the health-care system. Hypercalciuria remains the major risk factor for development of a Ca2+-containing stone. The kidney’s ability to alter Ca2+ excretion in response to changes in serum Ca2+ is in part mediated by the Ca2+-sensing receptor (CaSR). Recent studies revealed renal claudin-14 (Cldn14) expression localized to the thick ascending limb (TAL) and its expression to be regulated via the CaSR. We find that Cldn14 expression is increased by high dietary Ca2+ intake and by elevated serum Ca2+ levels induced by prolonged 1,25-dihydroxyvitamin D3 administration. Consistent with this, activation of the CaSR in vivo via administration of the calcimimetic cinacalcet hydrochloride led to a 40-fold increase in Cldn14 mRNA. Moreover, overexpression of Cldn14 in two separate cell culture models decreased paracellular Ca2+ flux by preferentially decreasing cation permeability, thereby increasing transepithelial resistance. These data support the existence of a mechanism whereby activation of the CaSR in the TAL increases Cldn14 expression, which in turn blocks the paracellular reabsorption of Ca2+. This molecular mechanism likely facilitates renal Ca2+ losses in response to elevated serum Ca2+. Moreover, dys-regulation of the newly described CaSR-Cldn14 axis likely contributes to the development of hypercalciuria and kidney stones. PMID:23283989

Where size does matter: foldable telescope design for microsat application

NASA Astrophysics Data System (ADS)

Segert, Tom; Danziger, Björn; Lieder, Matthias

2017-11-01

The DOBSON SPACE TELESCOPE Project (DST) at the Technical University of Berlin (TUB) believes that micro satellites can be a challenging competitor in the high resolution remote sensing market. Using a micro satellite as basis for a remote sensing platform will dramatically reduce the cost for the end users thereby initiating the predicted remote sensing boom. The Challenging task is that an optic required for a GSD smaller than 1m is much bigger than the given room for secondary payload. In order to break the volume limits of hitchhiker payloads the DST team develops an optical telescope with deployable structures. The core piece of DST is a 20 inch modified Cassegrain optic. Stored during ascend the instrument fits in a box measuring 60 x 60 x 30cm (including telescope and optical plane assembly). After the satellite was released into free space the telescope unfolds and collimates automatically.

Future Plans in US Flight Missions: Using Laser Remote Sensing for Climate Science Observations

NASA Technical Reports Server (NTRS)

Callahan, Lisa W.

2010-01-01

Laser Remote Sensing provides critical climate science observations necessary to better measure, understand, model and predict the Earth's water, carbon and energy cycles. Laser Remote Sensing applications for studying the Earth and other planets include three dimensional mapping of surface topography, canopy height and density, atmospheric measurement of aerosols and trace gases, plume and cloud profiles, and winds measurements. Beyond the science, data from these missions will produce new data products and applications for a multitude of end users including policy makers and urban planners on local, national and global levels. NASA Missions in formulation including Ice, Cloud, and land Elevation Satellite (ICESat 2) and the Deformation, Ecosystem Structure, and Dynamics of Ice (DESDynI), and future missions such as the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS), will incorporate the next generation of LIght Detection And Ranging (lidar) instruments to measure changes in the surface elevation of the ice, quantify ecosystem carbon storage due to biomass and its change, and provide critical data on CO 2 in the atmosphere. Goddard's plans for these instruments and potential uses for the resulting data are described below. For the ICESat 2 mission, GSFC is developing a micro-pulse multi-beam lidar. This instrument will provide improved ice elevation estimates over high slope and very rough areas and result in improved lead detection for sea ice estimates. Data about the sea ice and predictions related to sea levels will continue to help inform urban planners as the changes in the polar ice accelerate. DESDynI is planned to be launched in 2017 and includes both lidar and radar instruments. GSFC is responsible for the lidar portion of the DESDynI mission and is developing a scanning laser altimeter that will measure the Earth's topography, the structure of tree canopies, biomass, and surface roughness. The DESDynI lidar will also measure and predict the response of ice masses to climate change and impact on sea level. Data from the lidar will ultimately be fused with radar data products with heretofore unseen results and applications. The 3-D structure of forests is critical to understanding the impact of land use and associated landscape changes on the habitat of life forms and consequently on their biodiversity. Lidar instruments are also under development to measure trace gases in the atmospheric such as CO2 and methane. GSFC is developing an active measurement approach to determine the CO2 column density and surface pressure for the proposed ASCENDS mission. The objective of this approach is to produce data on the amounts of anthropogenic and organic CO2 in the atmosphere with sufficient accuracy to meet the needs of target users including state, federal and international users as well as policy-related legislative, regulatory, and voluntary carbon-related management groups local to international interests. In summary, NASA will continue to rely on laser remote sensing for critical climate science observations and is committed to the development of the next generation of lidar instruments for a range of applications.

Detectability of CO2 Flux Signals by a Space-Based Lidar Mission

NASA Technical Reports Server (NTRS)

Hammerling, Dorit M.; Kawa, S. Randolph; Schaefer, Kevin; Doney, Scott; Michalak, Anna M.

2015-01-01

Satellite observations of carbon dioxide (CO2) offer novel and distinctive opportunities for improving our quantitative understanding of the carbon cycle. Prospective observations include those from space-based lidar such as the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. Here we explore the ability of such a mission to detect regional changes in CO2 fluxes. We investigate these using three prototypical case studies, namely the thawing of permafrost in the Northern High Latitudes, the shifting of fossil fuel emissions from Europe to China, and changes in the source-sink characteristics of the Southern Ocean. These three scenarios were used to design signal detection studies to investigate the ability to detect the unfolding of these scenarios compared to a baseline scenario. Results indicate that the ASCENDS mission could detect the types of signals investigated in this study, with the caveat that the study is based on some simplifying assumptions. The permafrost thawing flux perturbation is readily detectable at a high level of significance. The fossil fuel emission detectability is directly related to the strength of the signal and the level of measurement noise. For a nominal (lower) fossil fuel emission signal, only the idealized noise-free instrument test case produces a clearly detectable signal, while experiments with more realistic noise levels capture the signal only in the higher (exaggerated) signal case. For the Southern Ocean scenario, differences due to the natural variability in the ENSO climatic mode are primarily detectable as a zonal increase.

High-Speed On-Board Data Processing for Science Instruments

NASA Technical Reports Server (NTRS)

Beyon, Jeffrey Y.; Ng, Tak-Kwong; Lin, Bing; Hu, Yongxiang; Harrison, Wallace

2014-01-01

A new development of on-board data processing platform has been in progress at NASA Langley Research Center since April, 2012, and the overall review of such work is presented in this paper. The project is called High-Speed On-Board Data Processing for Science Instruments (HOPS) and focuses on a high-speed scalable data processing platform for three particular National Research Council's Decadal Survey missions such as Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS), Aerosol-Cloud-Ecosystems (ACE), and Doppler Aerosol Wind Lidar (DAWN) 3-D Winds. HOPS utilizes advanced general purpose computing with Field Programmable Gate Array (FPGA) based algorithm implementation techniques. The significance of HOPS is to enable high speed on-board data processing for current and future science missions with its reconfigurable and scalable data processing platform. A single HOPS processing board is expected to provide approximately 66 times faster data processing speed for ASCENDS, more than 70% reduction in both power and weight, and about two orders of cost reduction compared to the state-of-the-art (SOA) on-board data processing system. Such benchmark predictions are based on the data when HOPS was originally proposed in August, 2011. The details of these improvement measures are also presented. The two facets of HOPS development are identifying the most computationally intensive algorithm segments of each mission and implementing them in a FPGA-based data processing board. A general introduction of such facets is also the purpose of this paper.

Calpain-2 Compensation Promotes Angiotensin II-Induced Ascending and Abdominal Aortic Aneurysms in Calpain-1 Deficient Mice

PubMed Central

Subramanian, Venkateswaran; Moorleghen, Jessica J.; Balakrishnan, Anju; Howatt, Deborah A.; Chishti, Athar H.; Uchida, Haruhito A.

2013-01-01

Background and Objective Recently, we demonstrated that angiotensin II (AngII)-infusion profoundly increased both aortic protein and activity of calpains, calcium-activated cysteine proteases, in mice. In addition, pharmacological inhibition of calpain attenuated AngII-induced abdominal aortic aneurysm (AA) in mice. Recent studies have shown that AngII infusion into mice leads to aneurysmal formation localized to the ascending aorta. However, the precise functional contribution of calpain isoforms (-1 or -2) in AngII-induced abdominal AA formation is not known. Similarly, a functional role of calpain in AngII-induced ascending AA remains to be defined. Using BDA-410, an inhibitor of calpains, and calpain-1 genetic deficient mice, we examined the relative contribution of calpain isoforms in AngII-induced ascending and abdominal AA development. Methodology/Results To investigate the relative contribution of calpain-1 and -2 in development of AngII-induced AAs, male LDLr −/− mice that were either calpain-1 +/+ or −/− were fed a saturated fat-enriched diet and infused with AngII (1,000 ng/kg/min) for 4 weeks. Calpain-1 deficiency had no significant effect on body weight or blood pressure during AngII infusion. Moreover, calpain-1 deficiency showed no discernible effects on AngII-induced ascending and abdominal AAs. Interestingly, AngII infusion induced increased expression of calpain-2 protein, thus compensating for total calpain activity in aortas of calpain-1 deficient mice. Oral administration of BDA-410, a calpain inhibitor, along with AngII-infusion significantly attenuated AngII-induced ascending and abdominal AA formation in both calpain-1 +/+ and −/− mice as compared to vehicle administered mice. Furthermore, BDA-410 administration attenuated AngII-induced aortic medial hypertrophy and macrophage accumulation. Western blot and immunostaining analyses revealed BDA-410 administration attenuated AngII-induced C-terminal fragmentation of filamin A, an actin binding cytoskeletal protein in aorta. Conclusion Calpain-2 compensates for loss of calpain-1, and both calpain isoforms are involved in AngII-induced aortic aneurysm formation in mice. PMID:23977256

Using the Inflection Points and Rates of Growth and Decay to Predict Levels of Solar Activity

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2008-01-01

The ascending and descending inflection points and rates of growth and decay at specific times during the sunspot cycle are examined as predictors for future activity. On average, the ascending inflection point occurs about 1-2 yr after sunspot minimum amplitude (Rm) and the descending inflection point occurs about 6-7 yr after Rm. The ascending inflection point and the inferred slope (including the 12-mo moving average (12-mma) of (Delta)R (the month-to-month change in the smoothed monthly mean sunspot number (R)) at the ascending inflection point provide strong indications as to the expected size of the ongoing cycle s sunspot maximum amplitude (RM), while the descending inflection point appears to provide an indication as to the expected length of the ongoing cycle. The value of the 12-mma of (Delta)R at elapsed time T = 27 mo past the epoch of RM (E(RM)) seems to provide a strong indication as to the expected size of Rm for the following cycle. The expected Rm for cycle 24 is 7.6 +/- 4.4 (the 90-percent prediction interval), occurring before September 2008. Evidence is also presented for secular rises in selected cycle-related parameters and for preferential grouping of sunspot cycles by amplitude and/or period.

Assessment of meteorological uncertainties as they apply to the ASCENDS mission

NASA Astrophysics Data System (ADS)

Snell, H. E.; Zaccheo, S.; Chase, A.; Eluszkiewicz, J.; Ott, L. E.; Pawson, S.

2011-12-01

Many environment-oriented remote sensing and modeling applications require precise knowledge of the atmospheric state (temperature, pressure, water vapor, surface pressure, etc.) on a fine spatial grid with a comprehensive understanding of the associated errors. Coincident atmospheric state measurements may be obtained via co-located remote sensing instruments or by extracting these data from ancillary models. The appropriate technique for a given application depends upon the required accuracy. State-of-the-art mesoscale/regional numerical weather prediction (NWP) models operate on spatial scales of a few kilometers resolution, and global scale NWP models operate on scales of tens of kilometers. Remote sensing measurements may be made on spatial scale comparable to the measurement of interest. These measurements normally require a separate sensor, which increases the overall size, weight, power and complexity of the satellite payload. Thus, a comprehensive understanding of the errors associated with each of these approaches is a critical part of the design/characterization of a remote-sensing system whose measurement accuracy depends on knowledge of the atmospheric state. One of the requirements as part of the overall ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission development is to develop a consistent set of atmospheric state variables (vertical temperature and water vapor profiles, and surface pressure) for use in helping to constrain overall retrieval error budget. If the error budget requires tighter uncertainties on ancillary atmospheric parameters than can be provided by NWP models and analyses, additional sensors may be required to reduce the overall measurement error and meet mission requirements. To this end we have used NWP models and reanalysis information to generate a set of atmospheric profiles which contain reasonable variability. This data consists of a "truth" set and a companion "measured" set of profiles. The truth set contains climatologically-relevant profiles of pressure, temperature and humidity with an accompanying surface pressure. The measured set consists of some number of instances of the truth set which have been perturbed to represent realistic measurement uncertainty for the truth profile using measurement error covariance matrices. The primary focus has been to develop matrices derived using information about the profile retrieval accuracy as documented for on-orbit sensor systems including AIRS, AMSU, ATMS, and CrIS. Surface pressure variability and uncertainty was derived from globally-compiled station pressure information. We generated an additional measurement set of profiles which represent the overall error within NWP models. These profile sets will allow for comprehensive trade studies for sensor system design and provide a basis for setting measurement requirements for co-located temperature, humidity sounders, determine the utility of NWP data to either replace or supplement collocated measurements, and to assess the overall end-to-end system performance of the sensor system. In this presentation we discuss the process by which we created these data sets and show their utility in performing trade studies for sensor system concepts and designs.

Satellite SAR imagery for site discovery, change detection and monitoring activities in cultural heritage sites: experiments on the Nasca region, Peru

NASA Astrophysics Data System (ADS)

Tapete, D.; Cigna, F.; Masini, N.; Lasaponara, R.

2012-04-01

Besides their suitability for multi-temporal and spatial deformation analysis, the Synthetic Aperture Radar (SAR) image archives acquired by space-borne radar sensors can be exploited to support archaeological investigations over huge sites, even those partially or totally buried and still to be excavated. Amplitude information is one of the main properties of SAR data from which it is possible to retrieve evidences of buried structures, using feature extraction and texture analysis. Multi-temporality allows the reconstruction of past and recent evolution of both landscape and built-up environment, with the possibility to detect natural and/or anthropogenic changes, including human-induced damages to the conservation of cultural heritage. We present the methodology and first results of the experiments currently undertaken using SAR data in the Nasca region (Southern Peru), where two important civilizations such as Paracas and Nasca developed and flourished from 4th century BC to the 6th century AD. The study areas include a wide spectrum of archaeological and environmental elements to be preserved, among which: the archaeological site of Cahuachi and its surroundings, considered the largest adobe Ceremonial Centre in the World; the Nasca lines and geoglyphs in the areas of Palpa, Atarco and Nasca; the ancient networks of aqueducts and drainage galleries in the Puquios area, built by Nasca in the 1st-6th centuries AD. Archaeological prospection and multi-purpose remote sensing activities are currently carried out in the framework of the Italian mission of heritage Conservation and Archaeogeophysics (ITACA), with the direct involvement of researchers from the Institute for Archaeological and Monumental Heritage and the Institute of Methodologies for Environmental Analysis, Italian National Research Council. In this context, C- and L-band SAR images covering the Nasca region since 2001 were identified for the purposes of this research and, in particular, the following data stacks were selected: ERS-2 ascending data acquired in 2001-2011, ENVISAT ASAR ascending and descending data acquired in 2003-2007, and ALOS PALSAR descending and ascending data acquired in 2007 and 2008. The feature extraction was specifically addressed to the recognition of buried structures, archaeological deposits and the study of the buried networks of aqueducts, as well as the morphological study of the Nasca geoglyphs. Change detection analysis also included the multi-temporal reconstruction of the evolution of the Rio Nasca catchment basin, while specific tests were performed to demonstrate the usefulness of SAR imagery for monitoring looting activities. The results of the radar-interpretation compared and integrated with the field investigations will support the archaeological activities and contribute to the monitoring and enhancement of archaeological heritage and cultural landscape of the Nasca region.

Ionospheric winter anomaly and annual anomaly observed from Formosat-3/COSMIC Radio Occultation observations during the ascending phase of solar cycle 24

NASA Astrophysics Data System (ADS)

Sai Gowtam, V.; Tulasi Ram, S.

2017-10-01

Ionospheric winter and annual anomalies have been investigated during the ascending phase of solar cycle 24 using high-resolution global 3D - data of the FORMOSAT - 3/COSMIC (Formosa satellite - 3/Constellation Observing System for Meterology, Ionosphere and Climate) radio occultation observations. Our detailed analysis shows that the occurrence of winter anomaly at low-latitudes is confined only to the early morning to afternoon hours, whereas, the winter anomaly at mid-latitudes is almost absent at all local times during the ascending phase of solar cycle 24. Further, in the topside ionosphere (altitudes of 400 km and above), the winter anomaly is completely absent at all local times. In contrast, the ionospheric annual anomaly is consistently observed at all local times and altitudes during this ascending phase of solar cycle 24. The annual anomaly exhibits strong enhancements over southern EIA crest latitudes during day time and around Weddle Sea Anomaly (WSA) region during night times. The global mean annual asymmetry index is also computed to understand the altitudinal variation. The global mean AI maximizes around 300-500 km altitudes during the low solar active periods (2008-10), whereas it extends up to 600 km during moderate to high (2011) solar activity period. These findings from our study provide new insights to the current understanding of the annual anomaly.

Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

NASA Astrophysics Data System (ADS)

Campbell, J. F.; Lin, B.; Obland, M. D.; Liu, Z.; Kooi, S. A.; Fan, T. F.; Nehrir, A. R.; Meadows, B.; Browell, E. V.

2016-12-01

Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 MeasurementsJoel F. Campbell1, Bing Lin1, Michael D. Obland1, Zhaoyan Liu1, Susan Kooi2, Tai-Fang Fan2, Amin R. Nehrir1, Byron Meadows1, Edward V. Browell31NASA Langley Research Center, Hampton, VA 23681 2SSAI, NASA Langley Research Center, Hampton, VA 23681 3STARSS-II Affiliate, NASA Langley Research Center, Hampton, VA 23681 AbstractGlobal and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and the Atmospheric Carbon and Transport (ACT) - America project are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the ASCENDS and ACT-America science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby minimizing bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new sub-meter hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. These techniques are used in a new data processing architecture written in the C language to support the ASCENDS CarbonHawk Experiment Simulator (ACES) and ACT-America programs. This software is about an order of magnitude faster than the Mathematica code previously used and uses multithreaded parallel processing code that takes advantage of multicore processors.

A Round Robin evaluation of AMSR-E soil moisture retrievals

NASA Astrophysics Data System (ADS)

Mittelbach, Heidi; Hirschi, Martin; Nicolai-Shaw, Nadine; Gruber, Alexander; Dorigo, Wouter; de Jeu, Richard; Parinussa, Robert; Jones, Lucas A.; Wagner, Wolfgang; Seneviratne, Sonia I.

2014-05-01

Large-scale and long-term soil moisture observations based on remote sensing are promising data sets to investigate and understand various processes of the climate system including the water and biochemical cycles. Currently, the ESA Climate Change Initiative for soil moisture develops and evaluates a consistent global long-term soil moisture data set, which is based on merging passive and active remotely sensed soil moisture. Within this project an inter-comparison of algorithms for AMSR-E and ASCAT Level 2 products was conducted separately to assess the performance of different retrieval algorithms. Here we present the inter-comparison of AMSR-E Level 2 soil moisture products. These include the public data sets from University of Montana (UMT), Japan Aerospace and Space Exploration Agency (JAXA), VU University of Amsterdam (VUA; two algorithms) and National Aeronautics and Space Administration (NASA). All participating algorithms are applied to the same AMSR-E Level 1 data set. Ascending and descending paths of scaled surface soil moisture are considered and evaluated separately in daily and monthly resolution over the 2007-2011 time period. Absolute values of soil moisture as well as their long-term anomalies (i.e. removing the mean seasonal cycle) and short-term anomalies (i.e. removing a five weeks moving average) are evaluated. The evaluation is based on conventional measures like correlation and unbiased root-mean-square differences as well as on the application of the triple collocation method. As reference data set, surface soil moisture of 75 quality controlled soil moisture sites from the International Soil Moisture Network (ISMN) are used, which cover a wide range of vegetation density and climate conditions. For the application of the triple collocation method, surface soil moisture estimates from the Global Land Data Assimilation System are used as third independent data set. We find that the participating algorithms generally display a better performance for the descending compared to the ascending paths. A first classification of the sites defined by geographical locations show that the algorithms have a very similar average performance. Further classifications of the sites by land cover types and climate regions will be conducted which might result in a more diverse performance of the algorithms.

Atmospheric CO2 Column Measurements with an Airborne Intensity-Modulated Continuous-Wave 1.57-micron Fiber Laser Lidar

NASA Technical Reports Server (NTRS)

Dobler, Jeremy T.; Harrison, F. Wallace; Browell, Edward V.; Lin, Bing; McGregor, Doug; Kooi, Susan; Choi, Yonghoon; Ismail, Syed

2013-01-01

The 2007 National Research Council (NRC) Decadal Survey on Earth Science and Applications from Space recommended Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) as a mid-term, Tier II, NASA space mission. ITT Exelis, formerly ITT Corp., and NASA Langley Research Center have been working together since 2004 to develop and demonstrate a prototype Laser Absorption Spectrometer for making high-precision, column CO2 mixing ratio measurements needed for the ASCENDS mission. This instrument, called the Multifunctional Fiber Laser Lidar (MFLL), operates in an intensity-modulated, continuous-wave mode in the 1.57- micron CO2 absorption band. Flight experiments have been conducted with the MFLL on a Lear-25, UC-12, and DC-8 aircraft over a variety of different surfaces and under a wide range of atmospheric conditions. Very high-precision CO2 column measurements resulting from high signal-to-noise (great than 1300) column optical depth measurements for a 10-s (approximately 1 km) averaging interval have been achieved. In situ measurements of atmospheric CO2 profiles were used to derive the expected CO2 column values, and when compared to the MFLL measurements over desert and vegetated surfaces, the MFLL measurements were found to agree with the in situ-derived CO2 columns to within an average of 0.17% or approximately 0.65 ppmv with a standard deviation of 0.44% or approximately 1.7 ppmv. Initial results demonstrating ranging capability using a swept modulation technique are also presented.

Laser Sounder for Measuring Atmospheric CO2 Concentrations: Progress Toward Ascends

NASA Technical Reports Server (NTRS)

Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Sun, X.; Stephen, M. A.; Wilson, E.; Burris, J. F.; Mao, J.

2008-01-01

The next generation of space-based, active remote sensing instruments for measurement of tropospheric CO2 promises a capability to quantify global carbon sources and sinks at regional scales. Active (laser) methods will extend CO2 measurement coverage in time, space, and perhaps precision such that the underlying mechanisms for carbon exchange at the surface can be understood with .sufficient detail to confidently project the future of carbon-climate interaction and the influence of remediative policy actions. The recent Decadal Survey for Earth Science by the US National Research Council has recommended such a mission called the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) for launch in 2013-2016. We have been developing a laser technique for measurement of tropospheric CO2 for a number of years. Our immediate goal is to develop and demonstrate the method and instrument technology that will permit measurements of the CO2 column abundance over a horizontal path and from aircraft at the few-ppmv level. Our longer-term goal is to demonstrate the required capabilities of the technique, develop a space mission approach, and design the instrument for an ASCENDS-type mission. Our approach is to use a dual channel laser absorption spectrometer (i.e., differential absorption in altimeter mode), which continuously measures from a near-polar circular orbit. We use several co-aligned tunable fiber laser transmitters allowing simultaneous measurement of the absorption from a CO2 line in the 1570 nm band, O2 extinction in the oxygen A-band (near 765 nm), and aerosol backscatter in the same measurement path. We measure the energy of the laser echoes at nadir reflected from land and water surfaces, day and night. The lasers have spectral widths much narrower than the gas absorption lines and are turned on and off the selected CO2 and O2 lines at kHz rates. The gas extinction and column densities for the CO2 and O2 gases are estimated from the ratio of the on and off-line singnals via the DIAL technique. We used pulsed laser signals, photon counting detectors, and time gating to isolate the laser returns from the surface, and to reject photons scattered from thin clouds and aerosols. High signal-to-noise ratios are required and the CO2 estimates can be sensitive to small drifts or other errors in the instrument, so the absorption estimates need to be quite stable for hours. We have constructed a breadboard version of the CO2 sensor that uses a low power fiber laser and a 20 cm diameter telescope. We have used it to make measurements of CO2 absorption in the laboratory and over 200-m to 2-km long open horizontal paths. These have been done in several sessions extending over multiple days, which allows us to assess the measurement stability and to compare absorption variations to readings from an external in situ CO2 sensor. We have also calculated characteristics of the technique for space including its expected measurement performance for different modulation types, and have performed an initial space mission accommodation study. We sill describe these results in the presentation.

Integrated Path Differential Absorption Lidar Optimizations Based on Pre-Analyzed Atmospheric Data for ASCENDS Mission Applications

NASA Technical Reports Server (NTRS)

Pliutau, Denis; Prasad, Narasimha S.

2012-01-01

In this paper a modeling method based on data reductions is investigated which includes pre analyzed MERRA atmospheric fields for quantitative estimates of uncertainties introduced in the integrated path differential absorption methods for the sensing of various molecules including CO2. This approach represents the extension of our existing lidar modeling framework previously developed and allows effective on- and offline wavelength optimizations and weighting function analysis to minimize the interference effects such as those due to temperature sensitivity and water vapor absorption. The new simulation methodology is different from the previous implementation in that it allows analysis of atmospheric effects over annual spans and the entire Earth coverage which was achieved due to the data reduction methods employed. The effectiveness of the proposed simulation approach is demonstrated with application to the mixing ratio retrievals for the future ASCENDS mission. Independent analysis of multiple accuracy limiting factors including the temperature, water vapor interferences, and selected system parameters is further used to identify favorable spectral regions as well as wavelength combinations facilitating the reduction in total errors in the retrieved XCO2 values.

Motor cortex stimulation and neuropathic pain: how does motor cortex stimulation affect pain-signaling pathways?

PubMed

Kim, Jinhyung; Ryu, Sang Baek; Lee, Sung Eun; Shin, Jaewoo; Jung, Hyun Ho; Kim, Sung June; Kim, Kyung Hwan; Chang, Jin Woo

2016-03-01

Neuropathic pain is often severe. Motor cortex stimulation (MCS) is used for alleviating neuropathic pain, but the mechanism of action is still unclear. This study aimed to understand the mechanism of action of MCS by investigating pain-signaling pathways, with the expectation that MCS would regulate both descending and ascending pathways. Neuropathic pain was induced in Sprague-Dawley rats. Surface electrodes for MCS were implanted in the rats. Tactile allodynia was measured by behavioral testing to determine the effect of MCS. For the pathway study, immunohistochemistry was performed to investigate changes in c-fos and serotonin expression; micro-positron emission tomography (mPET) scanning was performed to investigate changes of glucose uptake; and extracellular electrophysiological recordings were performed to demonstrate brain activity. MCS was found to modulate c-fos and serotonin expression. In the mPET study, altered brain activity was observed in the striatum, thalamic area, and cerebellum. In the electrophysiological study, neuronal activity was increased by mechanical stimulation and suppressed by MCS. After elimination of artifacts, neuronal activity was demonstrated in the ventral posterolateral nucleus (VPL) during electrical stimulation. This neuronal activity was effectively suppressed by MCS. This study demonstrated that MCS effectively attenuated neuropathic pain. MCS modulated ascending and descending pain pathways. It regulated neuropathic pain by affecting the striatum, periaqueductal gray, cerebellum, and thalamic area, which are thought to regulate the descending pathway. MCS also appeared to suppress activation of the VPL, which is part of the ascending pathway.

Altered Cav1.2 function in the Timothy syndrome mouse model produces ascending serotonergic abnormalities.

PubMed

Ehlinger, Daniel G; Commons, Kathryn G

2017-10-01

Polymorphism in the gene CACNA1C, encoding the pore-forming subunit of Cav1.2 L-type calcium channels, has one of the strongest genetic linkages to schizophrenia, bipolar disorder and major depressive disorder: psychopathologies in which serotonin signaling has been implicated. Additionally, a gain-of-function mutation in CACNA1C is responsible for the neurodevelopmental disorder Timothy syndrome that presents with prominent behavioral features on the autism spectrum. Given an emerging role for serotonin in the etiology of autism spectrum disorders (ASD), we investigate the relationship between Cav1.2 and the ascending serotonin system in the Timothy syndrome type 2 (TS2-neo) mouse, which displays behavioral features consistent with the core triad of ASD. We find that TS2-neo mice exhibit enhanced serotonin tissue content and axon innervation of the dorsal striatum, as well as decreased serotonin turnover in the amygdala. These regionally specific alterations are accompanied by an enhanced active coping response during acute stress (forced swim), serotonin neuron Fos activity in the caudal dorsal raphe, and serotonin type 1A receptor-dependent feedback inhibition of the rostral dorsal raphe nuclei. Collectively, these results suggest that the global gain-of-function Cav1.2 mutation associated with Timothy syndrome has pleiotropic effects on the ascending serotonin system including neuroanatomical changes, regional differences in forebrain serotonin metabolism and feedback regulatory control mechanisms within the dorsal raphe. Altered activity of the ascending serotonin system continues to emerge as a common neural signature across several ASD mouse models, and the capacity for Cav1.2 L-type calcium channels to impact both serotonin structure and function has important implications for several neuropsychiatric conditions. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Simulation Studies of Satellite Laser CO2 Mission Concepts

NASA Technical Reports Server (NTRS)

Kawa, Stephan Randy; Mao, J.; Abshire, J. B.; Collatz, G. J.; Sun X.; Weaver, C. J.

2011-01-01

Results of mission simulation studies are presented for a laser-based atmospheric CO2 sounder. The simulations are based on real-time carbon cycle process modeling and data analysis. The mission concept corresponds to ASCENDS as recommended by the US National Academy of Sciences Decadal Survey. Compared to passive sensors, active (lidar) sensing of CO2 from space has several potentially significant advantages that hold promise to advance CO2 measurement capability in the next decade. Although the precision and accuracy requirements remain at unprecedented levels of stringency, analysis of possible instrument technology indicates that such sensors are more than feasible. Radiative transfer model calculations, an instrument model with representative errors, and a simple retrieval approach complete the cycle from "nature" run to "pseudodata" CO2. Several mission and instrument configuration options are examined, and the sensitivity to key design variables is shown. Examples are also shown of how the resulting pseudo-measurements might be used to address key carbon cycle science questions.

Finland Validation of the New Blended Snow Product

NASA Technical Reports Server (NTRS)

Kim, E. J.; Casey, K. A.; Hallikainen, M. T.; Foster, J. L.; Hall, D. K.; Riggs, G. A.

2008-01-01

As part of an ongoing effort to validate satellite remote sensing snow products for the recentlydeveloped U.S. Air Force Weather Agency (AFWA) - NASA blended snow product, Satellite and in-situ data for snow extent and snow water equivalent (SWE) are evaluated in Finland for the 2006-2007 snow season Finnish Meteorological Institute (FMI) daily weather station data and Finnish Environment Institute (SYKE) bi-monthly snow course data are used as ground truth. Initial comparison results display positive agreement between the AFWA NASA Snow Algorithm (ANSA) snow extent and SWE maps and in situ data, with discrepancies in accordance with known AMSR-E and MODIS snow mapping limitations. Future ANSA product improvement plans include additional validation and inclusion of fractional snow cover in the ANSA data product. Furthermore, the AMSR-E 19 GHz (horizontal channel) with the difference between ascending and descending satellite passes (Diurnal Amplitude Variations, DAV) will be used to detect the onset of melt, and QuikSCAT scatterometer data (14 GHz) will be used to map areas of actively melting snow.

Spatial and Temporal Variability of Carbon Dioxide Using Structure Functions in Urban Areas: Insights for Future Active Remote CO2 Sensors

NASA Technical Reports Server (NTRS)

Choi, Yonghoon; Yang, Melissa; Kooi, Susan A.; Browell, Edward V.; DiGangi, Joshua P.

2015-01-01

High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaigns during July 2011 over Washington DC/Baltimore, MD; January-February 2013 over the San Joaquin Valley, CA; September 2013 over Houston, TX; and July-August 2014 over Denver, CO. Each of these campaigns have approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 kilometers) at 6-8 different sites in each of the urban areas. In this study, we used structure function analysis, which is a useful way to quantify spatial and temporal variability, by displaying differences with average observations, to evaluate the variability of CO2 in the 0-2 kilometers range (representative of the planetary boundary layer). These results can then be used to provide guidance in the development of science requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) mission to measure near-surface CO2 variability in different urban areas. We also compare the observed in-situ CO2 variability with the variability of the CO2 column-averaged optical depths in the 0-1 kilometer and 0-3.5 kilometers altitude ranges in the four geographically different urban areas, using vertical weighting functions for potential future ASCENDS lidar CO2 sensors operating in the 1.57 and 2.05 millimeter measurement regions. In addition to determining the natural variability of CO2 near the surface and in the column, radiocarbon method using continuous CO2 and CO measurements are used to examine the variation of emission quantification between anthropogenic and biogenic sources in the DC/Maryland urban site.

Integrating ambient noise with GIS for a new perspective on volcano imaging and monitoring: The case study of Mt. Etna

NASA Astrophysics Data System (ADS)

Guardo, R.; De Siena, L.

2017-11-01

The timely estimation of short- and long-term volcanic hazard relies on the availability of detailed 3D geophysical images of volcanic structures. High-resolution seismic models of the absorbing uppermost conduit systems and highly-heterogeneous shallowest volcanic layers, while particularly challenging to obtain, provide important data to locate feasible eruptive centres and forecast flank collapses and lava ascending paths. Here, we model the volcanic structures of Mt. Etna (Sicily, Italy) and its outskirts using the Horizontal to Vertical Spectral Ratio method, generally applied to industrial and engineering settings. The integration of this technique with Web-based Geographic Information System improves precision during the acquisition phase. It also integrates geological and geophysical visualization of 3D surface and subsurface structures in a queryable environment representing their exact three-dimensional geographic position, enhancing interpretation. The results show high-resolution 3D images of the shallowest volcanic and feeding systems, which complement (1) deeper seismic tomography imaging and (2) the results of recent remote sensing imaging. The study recovers a vertical structure that divides the pre-existing volcanic complexes of Ellittico and Cuvigghiuni. This could be interpreted as a transitional phase between the two systems. A comparison with recent remote sensing and geological results, however, shows that anomalies are generally related to volcano-tectonic structures active during the last 17 years. We infer that seismic noise measurements from miniaturized instruments, when combined with remote sensing techniques, represent an important resource to monitor volcanoes in unrest, reducing the risk of loss of human lives and instrumentation.

Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity

NASA Astrophysics Data System (ADS)

Markovitz, Craig D.; Hogan, Patrick S.; Wesen, Kyle A.; Lim, Hubert H.

2015-04-01

Objective. The corticofugal system can alter coding along the ascending sensory pathway. Within the auditory system, electrical stimulation of the auditory cortex (AC) paired with a pure tone can cause egocentric shifts in the tuning of auditory neurons, making them more sensitive to the pure tone frequency. Since tinnitus has been linked with hyperactivity across auditory neurons, we sought to develop a new neuromodulation approach that could suppress a wide range of neurons rather than enhance specific frequency-tuned neurons. Approach. We performed experiments in the guinea pig to assess the effects of cortical stimulation paired with broadband noise (PN-Stim) on ascending auditory activity within the central nucleus of the inferior colliculus (CNIC), a widely studied region for AC stimulation paradigms. Main results. All eight stimulated AC subregions induced extensive suppression of activity across the CNIC that was not possible with noise stimulation alone. This suppression built up over time and remained after the PN-Stim paradigm. Significance. We propose that the corticofugal system is designed to decrease the brain’s input gain to irrelevant stimuli and PN-Stim is able to artificially amplify this effect to suppress neural firing across the auditory system. The PN-Stim concept may have potential for treating tinnitus and other neurological disorders.

A subcortical inhibitory signal for behavioral arrest in the thalamus

PubMed Central

Dugué, Guillaume P.; Bokor, Hajnalka; Rousseau, Charly V.; Maglóczky, Zsófia; Havas, László; Hangya, Balázs; Wildner, Hendrik; Zeilhofer, Hanns Ulrich; Dieudonné, Stéphane; Acsády, László

2016-01-01

Organization of behavior requires rapid coordination of brainstem and forebrain activity. The exact mechanisms of effective communication between these regions are presently unclear. The intralaminar thalamus (IL) probably serves as a central hub in this circuit by connecting the critical brainstem and forebrain areas. Here we found that GABAergic/glycinergic fibers ascending from the pontine reticular formation (PRF) of the brainstem evoke fast and reliable inhibition in the IL thalamus via large, multisynaptic terminals. This inhibition was fine-tuned through heterogeneous GABAergic/glycinergic receptor ratios expressed at individual synapses. Optogenetic activation of PRF axons in the IL of freely moving mice led to behavioral arrest and transient interruption of awake cortical activity. An afferent system with comparable morphological features was also found in the human IL. These data reveal an evolutionarily conserved ascending system which gates forebrain activity through fast and powerful synaptic inhibition of the IL thalamus. PMID:25706472

Natural history of the ascending aorta after aortic valve replacement: risk factor analysis for late aortic complications after aortic valve replacement.

PubMed

Tsutsumi, Koji; Hashizume, Kenichi; Inoue, Yoshito

2016-05-01

The purpose of this study was to clarify the natural history of the ascending aorta and to identify risk factors for late ascending aortic events after first isolated aortic valve replacement (AVR). A total of 287 patients undergoing AVR were enrolled. The patients were categorized into two groups based on the diameter of the ascending aorta at the time of AVR, as determined by computed tomography: Group A (n = 233) was defined as an ascending aortic diameter <40 mm, and Group B (n = 54) was defined as an ascending aortic diameter ≥40 mm. The mean follow-up period was 7.6 years. The baseline diameter of the ascending aorta was 31.4 ± 4.8 mm in Group A and 44.7 ± 4.2 mm in Group B. These values increased to 35.9 ± 7.4 mm in Group A and 50.1 ± 7.3 mm in Group B during the follow-up period (P < 0.001). Ten patients had acute type A aortic dissection (Group A: 1 patient vs. Group B: 9 patients; P < 0.001), and three patients had enlargement of the ascending aorta to ≥55 mm in diameter (Group A: 1 patient vs. Group B: 2 patients). Multivariate analysis revealed that the baseline ascending aortic diameter was the only significant risk factor for developing late ascending aortic events (P < 0.001). AVR alone may not prevent further enlargement of the ascending aorta. An ascending aorta ≥40 mm in diameter at the time of AVR increased the risk of late ascending aortic events.

Development of a Pulsed 2-micron Laser Transmitter for CO2 Sensing from Space

NASA Technical Reports Server (NTRS)

Singh, Upendra N.; Yu, Jirong; Bai, Yingxin; Petros, Mulugeta; Menzies, Robert T.

2011-01-01

NASA Langley Research Center (LaRC), in collaboration with NASA Jet Propulsion Laboratory (JPL), is engaged in the development and demonstration of a highly efficient, versatile, 2-micron pulsed laser that can be used in a pulsed Differential Absorption Lidar (DIAL)/Integrated Path Differential Absorption (IPDA) instrument to make precise, high-resolution CO2 measurements to investigate sources, sinks, and fluxes of CO2. This laser transmitter will feature performance characteristics needed for an ASCENDS system that will be capable of delivering the CO2 measurement precision required by the Earth Science Decadal Survey (DS).

Fusion of Cross-Track TerraSAR-X PS Point Clouds over Las Vegas

NASA Astrophysics Data System (ADS)

Wang, Ziyun; Balz, Timo; Wei, Lianhuan; Liao, Mingsheng

2014-11-01

Persistent scatterer interferometry (PS-InSAR) is widely used in radar remote sensing. However, because the surface motion is estimated in the line-of-sight (LOS) direction, it is not possible to differentiate between vertical and horizontal surface motions from a single stack. Cross-track data, i.e. the combination of data from ascending and descending orbits, allows us to better analyze the deformation and to obtain 3d motion information. We implemented a cross-track fusion of PS-InSAR point cloud data, making it possible to separate the vertical and horizontal components of the surface motion.

Wall stress on ascending thoracic aortic aneurysms with bicuspid compared with tricuspid aortic valve.

PubMed

Xuan, Yue; Wang, Zhongjie; Liu, Raymond; Haraldsson, Henrik; Hope, Michael D; Saloner, David A; Guccione, Julius M; Ge, Liang; Tseng, Elaine

2018-03-08

Guidelines for repair of bicuspid aortic valve-associated ascending thoracic aortic aneurysms have been changing, most recently to the same criteria as tricuspid aortic valve-ascending thoracic aortic aneurysms. Rupture/dissection occurs when wall stress exceeds wall strength. Recent studies suggest similar strength of bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms; thus, comparative wall stress may better predict dissection in bicuspid aortic valve versus tricuspid aortic valve-ascending thoracic aortic aneurysms. Our aim was to determine whether bicuspid aortic valve-ascending thoracic aortic aneurysms had higher wall stresses than their tricuspid aortic valve counterparts. Patients with bicuspid aortic valve- and tricuspid aortic valve-ascending thoracic aortic aneurysms (bicuspid aortic valve = 17, tricuspid aortic valve = 19) greater than 4.5 cm underwent electrocardiogram-gated computed tomography angiography. Patient-specific 3-dimensional geometry was reconstructed and loaded to systemic pressure after accounting for prestress geometry. Finite element analyses were performed using the LS-DYNA solver (LSTC Inc, Livermore, Calif) with user-defined fiber-embedded material model to determine ascending thoracic aortic aneurysm wall stress. Bicuspid aortic valve-ascending thoracic aortic aneurysms 99th-percentile longitudinal stresses were 280 kPa versus 242 kPa (P = .028) for tricuspid aortic valve-ascending thoracic aortic aneurysms in systole. These stresses did not correlate to diameter for bicuspid aortic valve-ascending thoracic aortic aneurysms (r = -0.004) but had better correlation to tricuspid aortic valve-ascending thoracic aortic aneurysms diameter (r = 0.677). Longitudinal stresses on sinotubular junction were significantly higher in bicuspid aortic valve-ascending thoracic aortic aneurysms than in tricuspid aortic valve-ascending thoracic aortic aneurysms (405 vs 329 kPa, P = .023). Bicuspid aortic valve-ascending thoracic aortic aneurysm 99th-percentile circumferential stresses were 548 kPa versus 462 kPa (P = .033) for tricuspid aortic valve-ascending thoracic aortic aneurysms, which also did not correlate to bicuspid aortic valve-ascending thoracic aortic aneurysm diameter (r = 0.007). Circumferential and longitudinal stresses were greater in bicuspid aortic valve- than tricuspid aortic valve-ascending thoracic aortic aneurysms and were more pronounced in the sinotubular junction. Peak wall stress did not correlate with bicuspid aortic valve-ascending thoracic aortic aneurysm diameter, suggesting diameter alone in this population may be a poor predictor of dissection risk. Our results highlight the need for patient-specific aneurysm wall stress analysis for accurate dissection risk prediction. Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

NASA Astrophysics Data System (ADS)

Campbell, J. F.; Lin, B.; Nehrir, A. R.; Obland, M. D.; Liu, Z.; Browell, E. V.; Chen, S.; Kooi, S. A.; Fan, T. F.

2015-12-01

Global and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and Atmospheric Carbon and Transport (ACT) - America airborne investigation are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are being investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the mission science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of intervening optically thin clouds, thereby minimizing bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the Earth's surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques and provides very high (at sub-meter level) range resolution. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These techniques are used in a new data processing architecture to support the ASCENDS CarbonHawk Experiment Simulator (ACES) and ACT-America programs.

Leadership is associated with lower levels of stress

PubMed Central

Sherman, Gary D.; Lee, Jooa J.; Cuddy, Amy J. C.; Renshon, Jonathan; Oveis, Christopher; Gross, James J.; Lerner, Jennifer S.

2012-01-01

As leaders ascend to more powerful positions in their groups, they face ever-increasing demands. As a result, there is a common perception that leaders have higher stress levels than nonleaders. However, if leaders also experience a heightened sense of control—a psychological factor known to have powerful stress-buffering effects—leadership should be associated with reduced stress levels. Using unique samples of real leaders, including military officers and government officials, we found that, compared with nonleaders, leaders had lower levels of the stress hormone cortisol and lower reports of anxiety (study 1). In study 2, leaders holding more powerful positions exhibited lower cortisol levels and less anxiety than leaders holding less powerful positions, a relationship explained significantly by their greater sense of control. Altogether, these findings reveal a clear relationship between leadership and stress, with leadership level being inversely related to stress. PMID:23012416

Intense Geomagnetic Storms of Solar Cycle 24 and Associated Energetics

NASA Astrophysics Data System (ADS)

Rawat, R.; Echer, E.; Gonzalez, W. D.

2013-12-01

Solar cycle 24 commenced in November 2008 following a deep solar minimum. The solar activity picked up gradually and consequently led to increase in geomagnetic activity during the ascending phase of new cycle. From the start of this cycle till July 2013, only 12 intense geomagnetic storms (Dst < -100 nT) have occurred. We investigate the solar wind-interplanetary drivers for these intense geomagnetic storms using satellite data. Total energy Poynting flux (ɛ) representing the fraction of solar wind energy transferred into the magnetosphere during different storms will be calculated. Solar cycle 24 is weaker as compared to previous solar cycle (23). In this work, a comparative study of solar and geomagnetic signatures during the ascending phase of the two cycles will be carried out.

Ross procedure for ascending aortic replacement.

PubMed

Elkins, R C; Lane, M M; McCue, C

1999-06-01

Patients with aortic valve disease and aneurysm or dilatation of the ascending aorta require both aortic valve replacement and treatment of their ascending aortic disease. In children and young adults, the Ross operation is preferred when the aortic valve requires replacement, but the efficacy of extending this operation to include replacement of the ascending aorta or reduction of the dilated aorta has not been tested. We reviewed the medical records of 18 (5.9%) patients with aortic valve disease and an ascending aortic aneurysm and 26 (8.5%) patients with dilation of the ascending aorta, subgroups of 307 patients who had a Ross operation between August 1986 and February 1998. We examined operative and midterm results, including recent echocardiographic assessment of autograft valve function and ability of the autograft root and ascending aortic repair or replacement to maintain normal structural integrity. There was one operative death (2%) related to a perioperative stroke. Forty-two of 43 survivors have normal autograft valve function, with trace to mild autograft valve insufficiency, and one patient has moderate insufficiency at the most recent echocardiographic evaluation. None of the patients has dilatation of the autograft root or of the replaced or reduced ascending aorta. Early results with extension of the Ross operation to include replacement of an ascending aortic aneurysm or vertical aortoplasty for reduction of a dilated ascending aorta are excellent, with autograft valve function equal to that seen in similar patients without ascending aortic disease.

Activation of Anterior Insula during Self-Reflection

PubMed Central

Modinos, Gemma; Ormel, Johan; Aleman, André

2009-01-01

Background Functional neuroimaging studies have suggested activation of midline frontoparietal brain regions to be at the core of self-related processes. However, although some studies reported involvement of the insula, little attention has been paid to this region as forming part of the “self”-network. Methodology/Principal Findings Using functional magnetic resonance imaging (fMRI), we aimed at replicating and extending previous studies by scanning subjects whilst reflecting upon their own personal qualities as compared to those of an acquaintance. A third condition with statements about general knowledge was used to control for attention, semantic processing and decision making processes. The results showed a significant effect of task in brain activity, consistent with previous findings, by which both person conditions recruited a common set of medial prefrontal and posterior regions, yet significant differences between self and other were found in the medial prefrontal cortex (MPFC) and the anterior cingulate cortex (ACC). Notably, significant neural activation in the left anterior insula was observed as uniquely associated with self-reflection. Conclusions/Significance The results provide further evidence for the specific recruitment of anterior MPFC and ACC regions for self-related processing, and highlight a role for the insula in self-reflection. As the insula is closely connected with ascending internal body signals, this may indicate that the accumulation of changes in affective states that might be implied in self-processing may contribute to our sense of self. PMID:19242539

Activation of anterior insula during self-reflection.

PubMed

Modinos, Gemma; Ormel, Johan; Aleman, André

2009-01-01

Functional neuroimaging studies have suggested activation of midline frontoparietal brain regions to be at the core of self-related processes. However, although some studies reported involvement of the insula, little attention has been paid to this region as forming part of the "self"-network. Using functional magnetic resonance imaging (fMRI), we aimed at replicating and extending previous studies by scanning subjects whilst reflecting upon their own personal qualities as compared to those of an acquaintance. A third condition with statements about general knowledge was used to control for attention, semantic processing and decision making processes. The results showed a significant effect of task in brain activity, consistent with previous findings, by which both person conditions recruited a common set of medial prefrontal and posterior regions, yet significant differences between self and other were found in the medial prefrontal cortex (MPFC) and the anterior cingulate cortex (ACC). Notably, significant neural activation in the left anterior insula was observed as uniquely associated with self-reflection. The results provide further evidence for the specific recruitment of anterior MPFC and ACC regions for self-related processing, and highlight a role for the insula in self-reflection. As the insula is closely connected with ascending internal body signals, this may indicate that the accumulation of changes in affective states that might be implied in self-processing may contribute to our sense of self.

Ascending thoracic aortic aneurysms protect against myocardial infarctions.

PubMed

Chau, Katherine; Elefteriades, John A

2014-09-01

There has been increasing evidence that ascending thoracic aortic aneurysms (TAAs) protect against atherosclerosis. However, there have been no studies examining the relationship between ascending TAAs and clinical endpoints of atherosclerosis, such as stroke or peripheral arterial disease. In this study, we aim to characterize the relationship between TAAs and a specific clinical endpoint of atherosclerosis, myocardial infarction (MI). We compared prevalence of coronary artery disease (CAD) and MIs in 487 patients who underwent surgical repair for ascending TAAs to 500 control patients who did not have an ascending TAA. Multivariate binary logistic regression was used to calculate the odds of having MI if a patient had an ascending TAA versus any of several MI risk factors. There was a significantly lower prevalence of CAD and MI in the ascending TAA group than in the control TAA group. The odds of having a MI if a patient had a MI risk factor were all > 1 (more likely to have a MI), with the lowest statistically significant odds ratio being 1.54 (age; p = 0.001) and the highest being 14.9 (family history of MI; p < 0.001). The odds ratio of having a MI if a patient had an ascending TAA, however, was near 0 at 0.05 (p < 0.001). This study provides evidence that ascending TAAs protect against MIs, adding further support to the hypothesis that ascending TAAs protect against atherosclerotic disease.

Kinematic alterations of the lower limbs and pelvis during an ascending stairs task are associated with the degree of knee osteoarthritis severity.

PubMed

Gonçalves, Glaucia Helena; Selistre, Luiz Fernando Approbato; Petrella, Marina; Mattiello, Stela Márcia

2017-03-01

Individuals with knee osteoarthritis (OA) generally demonstrate great difficulty in ascending stairs. The strategies and compensations used by these individuals in stair activities have not been fully established. The purpose of this study was to investigate the joint kinematics of the pelvis, hip, knee and ankle throughout the gait cycle, in the sagittal and frontal planes, in individuals with mild and moderate knee OA, during an ascending stairs task. Thirty-one individuals with knee OA and 19 controls were subjected to clinical and radiographic analysis, divided into three groups: control, mild knee OA, and moderate knee OA. Participants answered a self-reported questionnaire, carried out performance-based tests, and their kinematic data were recorded during an ascending stairs task using an eight-camera Qualisys 3D-Motion analysis system. The individuals with moderate degrees of knee OA demonstrated kinematic alterations in the pelvis, hip, knee, and ankle in the sagittal plane. The individuals with mild degrees of knee OA demonstrated kinematic alterations of the hip in the frontal plane, and kinematic alterations of the ankle in the sagittal plane. The ascending stairs task allowed verification of meaningful information regarding gait strategies used by individuals with mild and moderate knee OA. The strategies of these two groups of individuals are different for this task, although more pronounced in individuals with moderate knee OA. The findings should be taken into account in the development of rehabilitation programs. Copyright © 2017 Elsevier B.V. All rights reserved.

Angiotensin II-induced hypertension blunts thick ascending limb NO production by reducing NO synthase 3 expression and enhancing threonine 495 phosphorylation

PubMed Central

Ramseyer, Vanesa D.; Gonzalez-Vicente, Agustin; Carretero, Oscar A.

2014-01-01

Thick ascending limbs reabsorb 30% of the filtered NaCl load. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl transport by this segment. In contrast, chronic angiotensin II (ANG II) infusion increases net thick ascending limb transport. NOS3 activity is regulated by changes in expression and phosphorylation at threonine 495 (T495) and serine 1177 (S1177), inhibitory and stimulatory sites, respectively. We hypothesized that NO production by thick ascending limbs is impaired by chronic ANG II infusion, due to reduced NOS3 expression, increased phosphorylation of T495, and decreased phosphorylation of S1177. Rats were infused with 200 ng·kg−1·min−1 ANG II or vehicle for 1 and 5 days. ANG II infusion for 5 days decreased NOS3 expression by 40 ± 12% (P < 0.007; n = 6) and increased T495 phosphorylation by 147 ± 26% (P < 0.008; n = 6). One-day ANG II infusion had no significant effect. NO production in response to endothelin-1 was blunted in thick ascending limbs from ANG II-infused animals [ANG II −0.01 ± 0.06 arbitrary fluorescence units (AFU)/min vs. 0.17 ± 0.02 AFU/min in controls; P < 0.01]. This was not due to reduced endothelin-1 receptor expression. Phosphatidylinositol 3,4,5-triphosphate (PIP3)-induced NO production was also reduced in ANG II-infused rats (ANG II −0.07 ± 0.06 vs. 0.13 ± 0.04 AFU/min in controls; P < 0.03), and this correlated with an impaired ability of PIP3 to increase S1177 phosphorylation. We conclude that in ANG II-induced hypertension NO production by thick ascending limbs is impaired due to decreased NOS3 expression and altered phosphorylation. PMID:25377910

Angiotensin II-induced hypertension blunts thick ascending limb NO production by reducing NO synthase 3 expression and enhancing threonine 495 phosphorylation.

PubMed

Ramseyer, Vanesa D; Gonzalez-Vicente, Agustin; Carretero, Oscar A; Garvin, Jeffrey L

2015-01-15

Thick ascending limbs reabsorb 30% of the filtered NaCl load. Nitric oxide (NO) produced by NO synthase 3 (NOS3) inhibits NaCl transport by this segment. In contrast, chronic angiotensin II (ANG II) infusion increases net thick ascending limb transport. NOS3 activity is regulated by changes in expression and phosphorylation at threonine 495 (T495) and serine 1177 (S1177), inhibitory and stimulatory sites, respectively. We hypothesized that NO production by thick ascending limbs is impaired by chronic ANG II infusion, due to reduced NOS3 expression, increased phosphorylation of T495, and decreased phosphorylation of S1177. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 1 and 5 days. ANG II infusion for 5 days decreased NOS3 expression by 40 ± 12% (P < 0.007; n = 6) and increased T495 phosphorylation by 147 ± 26% (P < 0.008; n = 6). One-day ANG II infusion had no significant effect. NO production in response to endothelin-1 was blunted in thick ascending limbs from ANG II-infused animals [ANG II -0.01 ± 0.06 arbitrary fluorescence units (AFU)/min vs. 0.17 ± 0.02 AFU/min in controls; P < 0.01]. This was not due to reduced endothelin-1 receptor expression. Phosphatidylinositol 3,4,5-triphosphate (PIP3)-induced NO production was also reduced in ANG II-infused rats (ANG II -0.07 ± 0.06 vs. 0.13 ± 0.04 AFU/min in controls; P < 0.03), and this correlated with an impaired ability of PIP3 to increase S1177 phosphorylation. We conclude that in ANG II-induced hypertension NO production by thick ascending limbs is impaired due to decreased NOS3 expression and altered phosphorylation. Copyright © 2015 the American Physiological Society.

Integrating passive seismicity with Web-Based GIS for a new perspective on volcano imaging and monitoring: the case study of Mt. Etna

NASA Astrophysics Data System (ADS)

Guardo, Roberto; De Siena, Luca

2017-04-01

The timely estimation of short- and long-term volcanic hazard relies on the existence of detailed 3D geophysical images of volcanic structures. High-resolution seismic models of the absorbing uppermost conduit systems and highly-heterogeneous shallowest volcanic layers, while particularly challenging to obtain, provide important data to locate feasible eruptive centers and forecast flank collapses and lava ascending paths. Here, we model the volcanic structures of Mt. Etna (Sicily, Italy) and its outskirts using the Horizontal to Vertical Spectral Ratio method, generally applied to industrial and engineering settings. The integration of this technique with Web-based Geographic Information System improves precision during the acquisition phase. It also integrates geological and geophysical visualization of 3D surface and subsurface structures in a queryable environment representing their exact three-dimensional geographic position, enhancing interpretation. The results show high-resolution 3D images of the shallowest volcanic and feeding systems, which complement (1) deeper seismic tomography imaging and (2) the results of recent remote sensing imaging. The main novelty with respect to previous model is the presence of a vertical structure that divides the pre-existing volcanic complexes of Ellittico and Cuvigghiuni. This could be interpreted as a transitional phase between the two systems. A comparison with recent remote sensing and geological results, however, shows clear connections between the anomaly and dynamic active during the last 15 years. We infer that seismic noise measurements from miniaturized instruments, when combined with remote sensing techniques, represent an important resource when monitoring volcanic media and eruptions, reducing the risk of loss of human lives and instrumentation.

Spatial Variability in Column CO2 Inferred from High Resolution GEOS-5 Global Model Simulations: Implications for Remote Sensing and Inversions

NASA Technical Reports Server (NTRS)

Ott, L.; Putman, B.; Collatz, J.; Gregg, W.

2012-01-01

Column CO2 observations from current and future remote sensing missions represent a major advancement in our understanding of the carbon cycle and are expected to help constrain source and sink distributions. However, data assimilation and inversion methods are challenged by the difference in scale of models and observations. OCO-2 footprints represent an area of several square kilometers while NASA s future ASCENDS lidar mission is likely to have an even smaller footprint. In contrast, the resolution of models used in global inversions are typically hundreds of kilometers wide and often cover areas that include combinations of land, ocean and coastal areas and areas of significant topographic, land cover, and population density variations. To improve understanding of scales of atmospheric CO2 variability and representativeness of satellite observations, we will present results from a global, 10-km simulation of meteorology and atmospheric CO2 distributions performed using NASA s GEOS-5 general circulation model. This resolution, typical of mesoscale atmospheric models, represents an order of magnitude increase in resolution over typical global simulations of atmospheric composition allowing new insight into small scale CO2 variations across a wide range of surface flux and meteorological conditions. The simulation includes high resolution flux datasets provided by NASA s Carbon Monitoring System Flux Pilot Project at half degree resolution that have been down-scaled to 10-km using remote sensing datasets. Probability distribution functions are calculated over larger areas more typical of global models (100-400 km) to characterize subgrid-scale variability in these models. Particular emphasis is placed on coastal regions and regions containing megacities and fires to evaluate the ability of coarse resolution models to represent these small scale features. Additionally, model output are sampled using averaging kernels characteristic of OCO-2 and ASCENDS measurement concepts to create realistic pseudo-datasets. Pseudo-data are averaged over coarse model grid cell areas to better understand the ability of measurements to characterize CO2 distributions and spatial gradients on both short (daily to weekly) and long (monthly to seasonal) time scales

Laser-induced retinal nerve fiber layer injury in the nonhuman primate

NASA Astrophysics Data System (ADS)

Zwick, Harry; Belkin, Michael; Zuclich, Joseph A.; Lund, David J.; Schuschereba, Steven T.; Scales, David K.

1996-04-01

We have evaluated the acute effects of Argon laser injury to the retinal nerve fiber layer (NFL) in the non-human primate. Single Argon laser exposures of 150 millijoules were employed to induce retinal NFL injury. Retinal NFL injury is not acute; unlike its parallel in retinal disease it has two components that emanate from the acute retinal injury site. The ascending component is more visible, primarily because it is ascending toward the disk, representing ganglion cell axons cut off from their nutrient base, the ganglion cell body; the descending component may require up to 3 weeks to develop. Its characterization depends on the distribution of retinal NFL and the slower degeneration of the ganglion cell bodies. Fluorescein angiography suggest a retinal capillary loss that occurs in the capillary bed of the retinal NFL defect. It may reflect a reduced capillary vascular requirement of the NFL as well as a possible reduction of activity in the axonal transport mechanisms in the ascending NFL defect.

Numerical Study on 4-1 Coal Seam of Xiaoming Mine in Ascending Mining

PubMed Central

Tianwei, Lan; Hongwei, Zhang; Sheng, Li; Weihua, Song; Batugin, A. C.; Guoshui, Tang

2015-01-01

Coal seams ascending mining technology is very significant, since it influences the safety production and the liberation of dull coal, speeds up the construction of energy, improves the stability of stope, and reduces or avoids deep hard rock mining induced mine disaster. Combined with the Xiaoming ascending mining mine 4-1, by numerical calculation, the paper analyses ascending mining 4-1 factors, determines the feasibility of ascending mining 4-1 coalbed, and proposes roadway layout program about working face, which has broad economic and social benefits. PMID:25866840

Hydrogeology of an ancient arid closed basin: implications for tabular sandstone-hosted uranium deposits

USGS Publications Warehouse

Sanford, R.F.

1990-01-01

Hydrogeologic modeling shows that tabular-type uranium deposits in the Grants uranium region of the San Juan basin, New Mexico, formed in zones of ascending and discharging regional ground-water flow. The association of either lacustrine mudstone or actively subsiding structures and uranium deposits can best be explained by the occurrence of lakes at topographic depressions where ground water having different sources and compositions is likely to converge, mix, and discharge. Ascending and discharging flow also explains the association of uranium deposits with underlying evaporites and suggests a brine interface. The simulations contradict previous suggestions that ground water moved downward in the mudflat. -Author

Comparison of metabolic cost and cardiovascular response to stair ascending and descending with walkers and canes in older adults.

PubMed

Foley, Michael; Bowen, Brett

2014-09-01

To compare oxygen cost (mL·kg(-1)·m(-1)) and cardiovascular response (beats/m) and oxygen consumption (mL·kg(-1)·min(-1)) and heart rate (beats/min) to stair ascending and descending with walkers, with canes, and without assistive devices (ADs) in older adults. Descriptive, repeated measures. Indoor stairway. Convenience sample of able-bodied volunteers, non-AD users (N=14; mean age, 63.71 ± 11.7 y; mean body mass, 72.7 ± 14.1 kg; mean height, 165.7 ± 9.2 cm). Participants performed 4 randomized trials of stair ascending and descending at their own self-selected speed with 3 ADs: single-point cane, standard walker (SW), and wheeled walker (WW). They also performed unassisted stair ascending and descending. Each trial consisted of a 5-minute steady-state session followed by a 2-minute data collection period. Steady-state expired ventilations were collected in Douglas bags for metabolic analysis. Oxygen cost (mL·kg(-1)·m(-1)), heart rate (HR) response (beats/m), oxygen consumption (mL·kg(-1)·min(-1)), and HR (beats/min) were compared for each trial of stair ascending and descending using analysis of variance repeated measures (P<.05). Greater oxygen cost (per meter) was found for stair ascending and descending using the single-point cane (121%), SW (217%), and WW (232%) compared with unassisted stair ascending and descending (P<.05). Increased HR response (per meter) was found for stair ascending and descending using the single-point cane (116%), SW (126%), and WW (147%) compared with unassisted stair ascending and descending (P<.05). However, oxygen consumption (per minute) and HR (per minute) were not significantly increased during stair ascending and descending with the ADs compared with unassisted stair ascending and descending. Participants stair ascended and descended at significantly (P<.05) reduced speeds during trials with the ADs. This research should aid clinicians by providing evidence to base recommendations on regarding AD usage when encountering stairs during home and community ambulation. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Aortic Cross-Sectional Area/Height Ratio and Outcomes in Patients With Bicuspid Aortic Valve and a Dilated Ascending Aorta.

PubMed

Masri, Ahmad; Kalahasti, Vidyasagar; Svensson, Lars G; Alashi, Alaa; Schoenhagen, Paul; Roselli, Eric E; Johnston, Douglas R; Rodriguez, L Leonardo; Griffin, Brian P; Desai, Milind Y

2017-06-01

In patients with bicuspid aortic valve and dilated proximal ascending aorta, we sought to assess (1) factors associated with increased longer-term cardiovascular mortality and (2) incremental prognostic use of indexing aortic root to patient height. We studied 969 consecutive bicuspid aortic valve patients (50±13 years; 87% men) with proximal aorta ≥4 cm, who also had a gated contrast-enhanced thoracic computed tomography or magnetic resonance angiography. A ratio of ascending aortic area/height was calculated on tomography, and ≥10 cm 2 /m was considered abnormal, as previously reported. Society of Thoracic Surgeons score and cardiovascular death were recorded. Greater than or equal to III+ aortic regurgitation and severe aortic stenosis were seen in 37% and 10%, respectively. Society of Thoracic Surgeons score and right ventricular systolic pressure were 2±3 and 15±16 mm Hg, respectively. Abnormal ascending aortic area/height ratio was noted in 33%; 44% underwent ascending aortic surgery at 34 days. At 10.8 years (interquartile range, 9.6-12.3), 82 (9%) died (0.4% in-hospital postoperative mortality). On multivariable Cox survival analysis, ascending aortic area/height ratio (hazard ratio, 2; 95% confidence interval, 1.20-3.35) was associated with cardiovascular death, whereas aortic surgery (hazard ratio, 0.46; confidence interval, 0.26-0.80) was associated with improved survival (both P <0.01). Of the 405 patients with ascending aortic diameter of 4.5 to 5.5 cm, 64% had an abnormal ascending aortic area/height ratio, and 70% deaths occurred in patients with an abnormal ratio. In bicuspid aortic valve patients with dilated proximal ascending aorta, ascending aortic area/height ratio was independently associated with cardiovascular death. © 2017 American Heart Association, Inc.

Purinergic and cholinergic neuro-neuronal transmission underlying reflexes activated by mucosal stimulation in the isolated guinea-pig ileum

PubMed Central

Spencer, Nick J; Walsh, Michelle; Smith, Terence K

2000-01-01

We present evidence that adenosine triphosphate (ATP) plays a major role in excitatory neuro-neuronal transmission in ascending and descending reflex pathways to the longitudinal (LM) and circular muscle (CM). A partitioned bath was used for the pharmacological isolation of a segment of guinea-pig ileum (∼6 cm in length), allowing drugs to be selectively applied to an intermediate region between the region where mucosal stimulation was applied and that where mechanical recordings were made. Brush stroking the mucosa (3 strokes) elicited a synchronous contraction of the LM and CM both above (ascending excitation) and below (descending excitation) the site of stimulation. All reflexes were abolished when tetrodotoxin (1 μm) was applied to the intermediate chamber. Hexamethonium (300 μm) added to the intermediate chamber abolished the ascending contraction in 15 % of oral preparations (from 26 preparations, 18 animals) and the descending contraction in 13 % of anal preparations studied (from 53 preparations, 48 animals). In the remaining 85 % of oral preparations, hexamethonium usually attenuated the oral contraction of the LM and CM. However, in the remaining 87 % of anal preparations, hexamethonium had no effect on the anal contraction of the LM and CM. Oral and anal reflexes that were hexamethonium resistant were either abolished or attenuated by the further addition of the P2 purinergic receptor antagonist pyridoxal phosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS, 10 μm) or α,β-methylene ATP (50–100 μm) to the intermediate chamber. 1,1-Dimethyl-4-phenyl-piperazinium iodide (DMPP, 20 μm) or α,β-methylene ATP (50–100 μm) stimulated both ascending and descending excitatory pathways, when applied to the intermediate chamber. In conclusion, ascending and descending neuro-neuronal transmission in excitatory nervous pathways to the LM and CM is complex and clearly involves neurotransmitter(s) other than acetylcholine (ACh). We suggest mucosal stimulation releases ACh and ATP in both ascending and descending excitatory reflex pathways that synapse with excitatory motoneurons to the LM and CM. PMID:10639107

[Application of a tape-like bandage for the ascending aorta in its poststenotic dilation and correction of the aortal valve stenosis].

PubMed

Popov, V V; Bol'shak, A A

2014-06-01

The aortal valve prosthesis in combination with a tape-like bandage of ascending aorta application was performed in 106 patients, suffering a failure with predominance of the aortal valve stenosis in conjunction with the ascending aorta poststenotic dilation, in a 2005 - 2014 yrs period in the clinic. The hospital lethality have constituted 0.9%. In accordance to echocardiography, the ascending aorta diameter preoperatively have constituted (48.7 +/- 1.4) mm at average, before discharge from the hospital--(40.1 +/- 1.2) mm, in late follow-up period--(41.3 +/- 1.2) mm. It is expedient to recommend the original method of a tape-like bandage of ascending aorta from the base of noncoronary sinus in the aortal sinuses dilation (45 mm and more) in combination with the aortal valve prosthesis in poststenotic dilation of ascending aorta.

Electromyography of the quadriceps in patellofemoral pain with patellar subluxation.

PubMed

Mohr, Karen J; Kvitne, Ronald S; Pink, Marilyn M; Fideler, Bradley; Perry, Jacquelin

2003-10-01

This study compared muscle activity and timing of gait phases during functional activities in 13 subjects with patellofemoral pain associated with lateral subluxation and in 11 subjects with healthy knees. Fine wire electromyography recorded activity in the vastus lateralis and vastus medialis oblique during walking and ascending and descending stairs. Subjects were filmed to divide the activities into phases and determine timing. The vastus medialis oblique and vastus lateralis had similar patterns during all activities. Subjects with patellofemoral pain had significantly increased activity in the vastus medialis oblique and vastus lateralis compared with the healthy subjects during the most demanding phases of the gait cycle, suggesting a generalized quadriceps weakness in the patients with patellofemoral pain. Timing differences were seen in walking and stair ascending with the subjects with patellofemoral pain spending significantly more time in stance compared with the healthy subjects. This may be an attempt to reduce the load on weak quadriceps. These data reflect a generalized quadriceps muscle weakness, rather than the prevailing theory of quadriceps muscle imbalance as an etiology of patellofemoral pain. Therefore, we support the practice of strengthening the entire quadriceps muscle group, rather than attempting to specifically target the vastus medialis oblique.

Motivational signage increases physical activity on a college campus.

PubMed

Ford, M Allison; Torok, Donald

2008-01-01

The authors evaluated whether motivational signage influenced rates of stair use relative to elevator use on a college campus. In March and April 2004, the authors observed students, faculty, staff, and any visitors accessing a college campus building. During Phase I, the authors monitored ascending stair and elevator use at the same time each weekday (Monday-Friday). During Phase II, the authors placed motivational signs encouraging stair use at the bottom of the stairs and outside and inside the elevators. During the third week (Phase III), the authors removed the signs. The authors observed 18,389 ascending trips during the 3 weeks of the study. Motivational signs significantly contributed to an 18.6% increase in stair use in the second week, which was maintained in the following week. The signage intervention successfully enhanced physical activity on a college campus by providing educational health tips that may have served as motivation to choose the stairs.

COMBINED REPLACEMENT OF THE AORTIC VALVE AND ASCENDING AORTA IN JEHOVAH'S WITNESSES: REPORT OF TWO CASES

PubMed Central

Beddermann, Christoph; Norman, John C.; Cooley, Denton A.

1979-01-01

Two Jehovah's Witnesses with large ascending thoracic aortic aneurysms and aortic insufficiency secondary to annuloaortic ectasia underwent successful combined replacement of the aortic valve and the ascending aorta. One patient received a composite graft containing an aortic valve prosthesis, which necessitated supravalvular coronary ostia reimplantation; the other patient underwent separate aortic valve and left supracoronary ascending aneurysm replacement, with reimplantation of the right coronary ostium into the graft. No blood or blood derivatives were administered. Both patients had uneventful recoveries and continue to do well. To our knowledge, they represent the first reported cases of successful combined replacement of the aortic valve and ascending aorta in Jehovah's Witnesses. Images PMID:15216324

The ascending reticular activating system from pontine reticular formation to the thalamus in the human brain.

PubMed

Yeo, Sang Seok; Chang, Pyung Hun; Jang, Sung Ho

2013-01-01

Action of the ascending reticular activating system (ARAS) on the cerebral cortex is responsible for achievement of consciousness. In this study, we attempted to reconstruct the lower single component of the ARAS from the reticular formation (RF) to the thalamus in the normal human brain using diffusion tensor imaging (DTI). Twenty six normal healthy subjects were recruited for this study. A 1.5-T scanner was used for scanning of diffusion tensor images, and the lower single component of the ARAS was reconstructed using FMRIB software. We utilized two ROIs for reconstruction of the lower single component of the ARAS: the seed ROI - the RF of the pons at the level of the trigeminal nerve entry zone, the target ROI - the intralaminar nuclei of the thalamus at the level of the commissural plane. The reconstructed ARAS originated from the pontine RF, ascended through the mesencephalic tegmentum just posterior to the red nucleus, and then terminated on the intralaminar nuclei of the thalamus. No significant differences in fractional anisotropy, mean diffusivity, and tract number were observed between hemispheres (p > 0.05). We reconstructed the lower single component of the ARAS from the RF to the thalamus in the human brain using DTI. The results of this study might be of value for the diagnosis and prognosis of patients with impaired consciousness.

Ascending paralysis associated with HIV infection

PubMed Central

Afzal, Aasim; Benjamin, Mina; Gummelt, Kyle L.; Afzal, Sadaf; Tribble, Marc

2015-01-01

We present two patients with a high viral load of HIV-1 who developed symptoms of ascending paralysis leading to respiratory failure and autonomic instability. One patient had symptom improvement with highly active antiretroviral therapy (HAART) and a subsequent decrease in viral load. The other patient improved with intravenous immunoglobulin therapy and did not show much improvement on HAART alone. There are several proposed mechanisms for peripheral neuropathies seen in HIV-infected patients, including a direct action of HIV on the nerve by neurotropic strains or formation of autoantibodies against nerve elements. The comparison of the response to different therapies in these two cases highlights the importance of understanding different pathophysiologies, as the treatment modality may differ. PMID:25552790

The cardiovascular macrophage: a missing link between gut microbiota and cardiovascular diseases?

PubMed

Chen, X; Zheng, L; Zheng, Y-Q; Yang, Q-G; Lin, Y; Ni, F-H; Li, Z-H

2018-03-01

The prevalence of cardiovascular diseases is on the rise. Interventions that would aid prevention or treatment of these diseases are essential. The microbes residing in the gut, collectively called "gut microbiota", produce a plethora of compounds that enter the bloodstream and affect the cardiovascular system. Signals ascending from gut microbiome are believed to modulate differentiation and functional activity of macrophages residing in perivascular tissue, atherosclerotic plaques, and perivascular areas of the brain. Cardiovascular macrophages may be the key players that transform the signals ascending from gut microbiome into increased predisposition to cardiovascular diseases. The present review summarizes the knowledge to date on potential relationships between gut microbiota, cardiovascular macrophages, and cardiovascular diseases.

Space-Based CO2 Active Optical Remote Sensing using 2-μm Triple-Pulse IPDA Lidar

NASA Astrophysics Data System (ADS)

Singh, Upendra; Refaat, Tamer; Ismail, Syed; Petros, Mulugeta

2017-04-01

Sustained high-quality column CO2 measurements from space are required to improve estimates of regional and global scale sources and sinks to attribute them to specific biogeochemical processes for improving models of carbon-climate interactions and to reduce uncertainties in projecting future change. Several studies show that space-borne CO2 measurements offer many advantages particularly over high altitudes, tropics and southern oceans. Current satellite-based sensing provides rapid CO2 monitoring with global-scale coverage and high spatial resolution. However, these sensors are based on passive remote sensing, which involves limitations such as full seasonal and high latitude coverage, poor sensitivity to the lower atmosphere, retrieval complexities and radiation path length uncertainties. CO2 active optical remote sensing is an alternative technique that has the potential to overcome these limitations. The need for space-based CO2 active optical remote sensing using the Integrated Path Differential Absorption (IPDA) lidar has been advocated by the Advanced Space Carbon and Climate Observation of Planet Earth (A-Scope) and Active Sensing of CO2 Emission over Nights, Days, and Seasons (ASCENDS) studies in Europe and the USA. Space-based IPDA systems can provide sustained, high precision and low-bias column CO2 in presence of thin clouds and aerosols while covering critical regions such as high latitude ecosystems, tropical ecosystems, southern ocean, managed ecosystems, urban and industrial systems and coastal systems. At NASA Langley Research Center, technology developments are in progress to provide high pulse energy 2-μm IPDA that enables optimum, lower troposphere weighted column CO2 measurements from space. This system provides simultaneous ranging; information on aerosol and cloud distributions; measurements over region of broken clouds; and reduces influences of surface complexities. Through the continual support from NASA Earth Science Technology Office, current efforts are focused on developing an aircraft-based 2-μm triple-pulse IPDA lidar for independent and simultaneous monitoring of CO2 and water vapor (H2O). Triple-pulse IPDA design, development and integration is based on the knowledge gathered from the successful demonstration of the airborne CO2 2-μm double-pulse IPDA lidar. IPDA transmitter enhancements include generating high-energy (80 mJ) and high repetition rate (50Hz) three successive pulses using a single pump pulse. IPDA receiver enhancement include an advanced, low noise (1 fW/Hz1/2) MCT e-APD detection system for improved measurement sensitivity. In place of H2O sensing, the triple-pulse IPDA can be tuned to measure CO2 with two different weighting functions using two on-lines and a common off-line. Modeling of a space-based high-energy 2-µm triple-pulse IPDA lidar was conducted to demonstrate CO2 measurement capability and to evaluate random and systematic errors. Projected performance shows <0.12% random error and <0.07% residual systematic error. These translate to near-optimum 0.5 ppm precision and 0.3 ppm bias in low-tropospheric column CO2 mixing ratio measurements from space for 10 second signal averaging over Railroad Valley reference surface using US Standard atmospheric model. In addition, measurements can be optimized by tuning on-lines based upon ground target scenarios, environment and science objectives. With 10 MHz detection bandwidth, surface ranging with an uncertainty of <3 m can be achieved as demonstrated from earlier airborne flights.

Reciprocal functional interactions between the brainstem and the lower spinal cord

PubMed Central

Yazawa, Itaru

2014-01-01

The interplay of the neuronal discharge patterns regarding respiration and locomotion was investigated using electrophysiological techniques in a decerebrate and arterially perfused in situ mouse preparation. The phrenic, tibial, and/or peroneal nerve discharge became clearly organized into discharge episodes of increasing frequency and duration, punctuated by periods of quiescence as the perfusion flow rate increased at room temperature. The modulated sympathetic tone induced by the hyperoxic/normocapnic state was found to activate the locomotor pattern generator (LPG) via descending pathways and generate a left and right alternating discharge during discharge episodes in the motor nerves. The rhythm coupling of respiration and locomotion occurred at a 1:1 frequency ratio. Although the phrenic discharge synchronized with the tibial discharge at all flow rates tested, the time lag between peaks of the two discharges during locomotion was ≈400 ms rather than ≈200 ms, suggesting spinal feedback via ascending pathways. The incidence of the phrenic and tibial discharge episodes decreased by ≈50% after spinalization at the twelfth thoracic cord and the respiratory rhythm was more regular. These results indicate that: (i) locomotion can be generated in a hyperoxic/normocapnic state induced by specific respiratory conditions, (ii) the central mechanism regarding entrainment of respiratory and locomotor rhythms relies on spinal feedback via ascending pathways, initiated by the activated LPG generating locomotion, and (iii) the increase in respiratory rate seen during locomotion is caused not only by afferent mechanical and nociceptive inputs but also by impulses from the activated spinal cord producing a locomotor-like discharge via ascending pathways. PMID:24910591

Spinal cord neuron classes in embryos of the smooth newt Triturus vulgaris: a horseradish peroxidase and immunocytochemical study.

PubMed

Harper, C E; Roberts, A

1993-04-29

Spinal cord neurons were investigated in embryos of Triturus vulgaris, the smooth newt, just prior to hatching. These embryos can swim if freed from their egg membranes. Horseradish peroxidase (HRP) labelling, together with GABA and glycine immunocytochemistry (ICC), revealed nine distinct anatomical classes of neuron. 1. Ventrolateral motoneurons with mainly dorsal dendrites, sometimes a descending central axon and peripheral axon innervating the trunk muscles. 2. Dorsal primary sensory Rohon-Beard neurons innervating skin and with dorsal ascending and descending axons in spinal cord. 3. Commissural interneurons with mid-cord unipolar soma, glycine-like immunoreactivity, dendrites on initial segment of ventral axon which crosses cord to ascend or branch. 4. Dorsolateral commissural interneurons with multipolar soma in dorsolateral position with dorsal dendrites and ventral axon which crosses and ascends or branches. 5. Giant dorsolateral commissural interneurons with large dorsolateral somata widely spaced (130-250 microns spacing) with process projecting dorsally to other side, dorsolateral dendrites and ventral axon which crosses to ascend and branch. 6. Dorsolateral ascending interneurons in dorsolateral position with multipolar soma and ascending axon on same side. 7. Ascending interneurons with unipolar soma, GABA-like immunoreactivity and ascending axon on same side. 8. Descending interneurons with bi- or multi-polar soma, extensive dorsal and ventral dendrites, and descending axon on same side. They may also have ascending axons. 9. Kolmer-Agduhr cerebrospinal fluid contacting neurons with cilia and microvilli in lateral corners of neural canal. GABA-like immunoreactivity, no dendrites and ascending axon. Eight of the nine cells classes were found to bear a marked resemblance to neurons previously described in zebrafish and Xenopus embryos in terms of their anatomy, distribution and immunoreactivity to GABA and glycine. Homologies and possible functions are discussed. Giant dorsolateral commissural neurons, were not found in Xenopus or teleosts but were present in Ambystoma mexicanum and Neoceratodus. The regular, possibly segmental longitudinal distribution pattern of these cells within the cord is unusual among amphibian spinal neurons.

Dilatation of the initially non-aneurysmal ascending aorta after replacement of a bicuspid versus tricuspid aortic valve.

PubMed

Zhang, Jing; Fan, Guangpu; Zhao, Hui; Wang, Xu; Wang, Zhiwei; Zhang, Peide; Wang, Wei

2016-12-01

Objective To compare the aortic diameter after isolated aortic valve replacement (AVR) in patients with a bicuspid (BAV) or tricuspid aortic valve (TAV) and an initially normal ascending aorta. Methods Patients with an ascending aortic diameter of < 45 mm who had undergone isolated AVR were studied. Ultrasonic cardiographic measurements of the ascending aortic diameter made pre- and postoperatively and follow-up data concerning adverse aortic events and death were analyzed. Results A total of 613 patients were included in this retrospective study; of these, 211 had a BAV and 402 had a TAV. In both groups, the ascending aorta significantly expanded but was non-aneurysmal during follow-up; however, the difference between the two groups was not significant. Cox regression analysis showed no significant effect associated with the presence of a BAV on adverse aortic events or death. Conclusion Dilatation of the ascending aorta was observed after AVR in both groups, but was not more pronounced in patients with a BAV. Long-term follow-up for ascending aortic aneurysm is necessary after AVR in both patients with a BAV and those with a TAV.

Dilatation of the initially non-aneurysmal ascending aorta after replacement of a bicuspid versus tricuspid aortic valve

PubMed Central

Zhang, Jing; Fan, Guangpu; Zhao, Hui; Wang, Xu; Wang, Zhiwei; Zhang, Peide

2016-01-01

Objective To compare the aortic diameter after isolated aortic valve replacement (AVR) in patients with a bicuspid (BAV) or tricuspid aortic valve (TAV) and an initially normal ascending aorta. Methods Patients with an ascending aortic diameter of < 45 mm who had undergone isolated AVR were studied. Ultrasonic cardiographic measurements of the ascending aortic diameter made pre- and postoperatively and follow-up data concerning adverse aortic events and death were analyzed. Results A total of 613 patients were included in this retrospective study; of these, 211 had a BAV and 402 had a TAV. In both groups, the ascending aorta significantly expanded but was non-aneurysmal during follow-up; however, the difference between the two groups was not significant. Cox regression analysis showed no significant effect associated with the presence of a BAV on adverse aortic events or death. Conclusion Dilatation of the ascending aorta was observed after AVR in both groups, but was not more pronounced in patients with a BAV. Long-term follow-up for ascending aortic aneurysm is necessary after AVR in both patients with a BAV and those with a TAV. PMID:27484890

Airborne Measurements of Atmospheric Pressure made Using an IPDA Lidar Operating in the Oxygen A-Band

NASA Technical Reports Server (NTRS)

Riris, Haris; Abshire, James B.; Stephen, Mark; Rodriquez, Michael; Allan, Graham; Hasselbrack, William; Mao, Jianping

2012-01-01

We report airborne measurements of atmospheric pressure made using an integrated path differential absorption (IPDA) lidar that operates in the oxygen A-band near 765 nm. Remote measurements of atmospheric temperature and pressure are needed for NASA s Active Sensing of CO2 Emissions Over Nights, Days, and Seasons (ASCENDS) mission to measure atmospheric CO2. Accurate measurements of tropospheric CO2 on a global scale are very important in order to better understand its sources and sinks and to improve our predictions of climate change. The goal of ASCENDS is to determine the CO2 dry mixing ratio with lidar measurements from space at a level of 1 ppm. Analysis to date shows that with current weather models, measurements of both the CO2 column density and the column density of dry air are needed. Since O2 is a stable molecule that uniformly mixed in the atmosphere, measuring O2 absorption in the atmosphere can be used to infer the dry air density. We have developed an airborne (IPDA) lidar for Oxygen, with support from the NASA ESTO IIP program. Our lidar uses DFB-based seed laser diodes, a pulsed modulator, a fiber laser amplifier, and a non-linear crystal to generate wavelength tunable 765 nm laser pulses with a few uJ/pulse energy. The laser pulse rate is 10 KHz, and average transmitted laser power is 20 mW. Our lidar steps laser pulses across a selected line O2 doublet near 764.7 nm in the Oxygen A-band. The direct detection lidar receiver uses a 20 cm diameter telescope, a Si APD detector in Geiger mode, and a multi-channel scalar to detect and record the time resolved laser backscatter in 40 separate wavelength channels. Subsequent analysis is used to estimate the transmission line shape of the doublet for the laser pulses reflected from the ground. Ground based data analysis allows averaging from 1 to 60 seconds to increase SNR in the transmission line shape of the doublet. Our retrieval algorithm fits the expected O2 lineshapes against the measurements and determines the atmospheric pressure by minimizing the error between the observations and model. We first demonstrated our airborne lidar during flights during summer 2010. We made several improvements and made measurements during the Ascends flights during July 2011. More information about the technique, lidar instrument, airborne measurements, and pressure estimates will be described in the presentation.

Study of the Blood Supply Fraction of the Ascending Aorta and Its Effect in Diagnosing Early Ascending Aortic Atherosclerosis.

PubMed

Wang, Kun; Cao, Tiesheng; Zhao, Lianbi; Yang, Yong; Feng, Yang; Duan, Yunyou; Yuan, Lijun; Xing, Changyang; Ren, Huari

2016-03-01

To investigate the capacity of blood storage of certain large arteries during diastole, we first studied the ascending aorta by echocardiography. The concept of the blood supply fraction of the ascending aorta was then introduced to evaluate elastic retraction of the ascending aortic wall and determine its role in diagnosing early atherosclerosis of the ascending aorta. First, we enrolled 120 healthy volunteers and divided them into 3 groups according to age: 20 to 35 years (B1 group), 36 to 50 years (B2 group), and 51 to 65 years (B3 group); there were 40 volunteers in each group. We used echocardiography to measure the blood supply fraction in each volunteer and compared the results for each group. Then we enrolled 40 patients (51-65 years) with early atherosclerosis of the ascending aorta, measured the blood supply fraction of each, and compared the results with the B3 group. The mean blood supply fractions ± SD in the B1, B2, and B3 groups were 21.75% ± 1.53%, 20.76% ± 1.62%, and 18.44% ± 1.19%, respectively. The fraction in the B3 group was significantly lower than those in the B1 and B2 groups (P < .01). The fraction in the patients with early atherosclerosis was 14.92% ± 1.01%, which was obviously lower than that in the B3 group (P < .01). The blood supply fraction of the ascending aorta decreases with age, and it could be used as a parameter for diagnosis of early atherosclerosis of the ascending aorta. © 2016 by the American Institute of Ultrasound in Medicine.

Second messenger production in avian medullary nephron segments in response to peptide hormones.

PubMed

Goldstein, D L; Reddy, V; Plaga, K

1999-03-01

We examined the sites of peptide hormone activation within medullary nephron segments of the house sparrow (Passer domesticus) kidney by measuring rates of hormone-induced generation of cyclic nucleotide second messenger. Thin descending limbs, thick ascending limbs, and collecting ducts had baseline activity of adenylyl cyclase that resulted in cAMP accumulation of 207 +/- 56, 147 +/- 31, and 151 +/- 41 fmol. mm-1. 30 min-1, respectively. In all segments, this activity increased 10- to 20-fold in response to forskolin. Activity of adenylyl cyclase in the thin descending limb was stimulated approximately twofold by parathyroid hormone (PTH) but not by any of the other hormones tested [arginine vasotocin (AVT), glucagon, atrial natriuretic peptide (ANP), or isoproterenol, each at 10(-6) M]. Thick ascending limb was stimulated two- to threefold by both AVT and PTH; however, glucagon and isoproterenol had no effect, and ANP stimulated neither cAMP nor cGMP accumulation. Adenylyl cyclase activity in the collecting duct was stimulated fourfold by AVT but not by the other hormones; likewise, ANP did not stimulate cGMP accumulation in this segment. These data support a tubular action of AVT and PTH in the avian renal medulla.

Study of seismic activity during the ascending and descending phases of solar activity

NASA Astrophysics Data System (ADS)

Sukma, Indriani; Abidin, Zamri Zainal

2017-06-01

The study of the solar cycle and geomagnetic index associated with the seismic activity from the year 1901 to the end of 2015 has been done for an area that covers the majority of China and its bordering countries. Data of sunspot number, solar wind speed, daily storm time index and earthquake number are collected from NOAA, NASA, WDC, OMNI and USGS databases and websites. The earthquakes are classified into small (M < 5) and large (M ≥ 5) magnitudes (in Richter scale). We investigated the variation of earthquake activities with the geomagnetic storm index due to the solar wind. We focused on their variation in the ascending and descending phases of solar cycle. From our study, we conclude that there is a correlation between the phases' geomagnetic index and solar wind speed. We have also suggested that there is a certain degree of correlation between solar activity and seismicity in these phases. For every solar cycle, we find that there is a trend for earthquakes to occur in greater numbers during the descending phase. This can be explained by the increment in the solar wind speed and geomagnetic storm index during this phase.

Case report and review of the literature total endovascular repair of acute ascending aortic rupture: a case report and review of the literature.

PubMed

McCallum, John C; Limmer, Karl K; Perricone, Anthony; Bandyk, Dennis; Kansal, Nikhil

2013-07-01

Thoracic aortic endografting has been successfully implemented to treat aneurysmal disease of the distal aortic arch and descending thoracic aorta. Although there are reports of ascending aortic endovascular interventions, the total endovascular repair of a ruptured ascending aorta secondary to a Type A dissection has not been described. We report the case of a 77-year-old patient who presented with a ruptured ascending aortic aneurysm secondary to degeneration of a Stanford type A aortic dissection. His surgical history was significant for orthotropic heart transplant 19 years prior. The dissection, aneurysm, and rupture occurred in the native aorta distal to the ascending aortic suture line. At presentation, he was hemodynamically unstable with a right hemothorax. We placed 3 Medtronic Talent Thoracic Stent Graft devices (Medtronic Inc, Minneapolis, MN) across the suture line in the ascending aorta, excluding the rupture. The patient survived and has been followed to 25 months.

Impact of renal medullary three-dimensional architecture on oxygen transport.

PubMed

Fry, Brendan C; Edwards, Aurélie; Sgouralis, Ioannis; Layton, Anita T

2014-08-01

We have developed a highly detailed mathematical model of solute transport in the renal medulla of the rat kidney to study the impact of the structured organization of nephrons and vessels revealed in anatomic studies. The model represents the arrangement of tubules around a vascular bundle in the outer medulla and around a collecting duct cluster in the upper inner medulla. Model simulations yield marked gradients in intrabundle and interbundle interstitial fluid oxygen tension (PO2), NaCl concentration, and osmolality in the outer medulla, owing to the vigorous active reabsorption of NaCl by the thick ascending limbs. In the inner medulla, where the thin ascending limbs do not mediate significant active NaCl transport, interstitial fluid composition becomes much more homogeneous with respect to NaCl, urea, and osmolality. Nonetheless, a substantial PO2 gradient remains, owing to the relatively high oxygen demand of the inner medullary collecting ducts. Perhaps more importantly, the model predicts that in the absence of the three-dimensional medullary architecture, oxygen delivery to the inner medulla would drastically decrease, with the terminal inner medulla nearly completely deprived of oxygen. Thus model results suggest that the functional role of the three-dimensional medullary architecture may be to preserve oxygen delivery to the papilla. Additionally, a simulation that represents low medullary blood flow suggests that the separation of thick limbs from the vascular bundles substantially increases the risk of the segments to hypoxic injury. When nephrons and vessels are more homogeneously distributed, luminal PO2 in the thick ascending limb of superficial nephrons increases by 66% in the inner stripe. Furthermore, simulations predict that owing to the Bohr effect, the presumed greater acidity of blood in the interbundle regions, where thick ascending limbs are located, relative to that in the vascular bundles, facilitates the delivery of O2 to support the high metabolic requirements of the thick limbs and raises NaCl reabsorption. Copyright © 2014 the American Physiological Society.

[Endovascular repair of primary retrograde Stanford type A aortic dissection].

PubMed

Wu, H W; Sun, L; Li, D M; Jing, H; Xu, B; Wang, C T; Zhang, L

2016-10-01

Objective: To summarize the short- and mid-term results on endovascular repair of primary retrograde Stanford type A aortic dissection with an entry tear in distal aortic arch or descending aorta. Methods: Between December 2009 and December 2014, 21 male patients of primary retrograde Stanford type A aortic dissection with a mean age of (52±9) years received endovascular repair in Department of Cardiothoracic Surgery, Jinling Hospital. Among the 21 cases, 17 patients were presented as ascending aortic intramural hematoma, 4 patients as active blood flow in false lumen and partial thrombosis, 8 patients as ulcer on descending aorta combined intramural hematoma in descending aorta, and 13 patients as typical dissection changes. All patients received endovascular stent-graft repair successfully, with 15 cases in acute phase and 6 cases in chronic phase. Results: Cone stent was implanted in 13 cases, while straight stent in 8 cases, including 1 case of left common carotid-left subclavian artery bypass surgery and 1 case of restrictive bare-metal stent implantation. No perioperative stroke, paraplegia, stent fracture or displacement, limbs or abdominal organ ischemia or other severe complications occured, except for tracheotomy in 2 patients. Active blood flow in ascending aorta or aortic arch disappeared, and intramural hematoma started being absorbed on CT angiography images before discharge. All patients were alive during follow-up (6 to 72 months), and intramural hematoma in ascending aorta and aortic arch was absorbed thoroughly. Type Ⅰ endoleak and ulcer expansion were found in 1 patient, and type Ⅳ endoleak in distal stent was found in another one patient. Secondary ascending aortic dissection was found in 1 case two years later, which was cured by hybrid procedure with cardiopulmonary bypass. Conclusion: Endovascular repair of primary retrograde Stanford type A aortic dissection was safe and effective, which correlated with favorable short- and mid-term results.

Multiple Oxygen Tension Environments Reveal Diverse Patterns of Transcriptional Regulation in Primary Astrocytes

PubMed Central

Zhou, Yu; Wang, Liyun; Park, Sung-Soo; Martin, Bronwen; Wang, Rui; Becker, Kevin G.; Wood, William H.; Zhang, Yongqing; Peers, Chris; Maudsley, Stuart

2011-01-01

The central nervous system normally functions at O2 levels which would be regarded as hypoxic by most other tissues. However, most in vitro studies of neurons and astrocytes are conducted under hyperoxic conditions without consideration of O2-dependent cellular adaptation. We analyzed the reactivity of astrocytes to 1, 4 and 9% O2 tensions compared to the cell culture standard of 20% O2, to investigate their ability to sense and translate this O2 information to transcriptional activity. Variance of ambient O2 tension for rat astrocytes resulted in profound changes in ribosomal activity, cytoskeletal and energy-regulatory mechanisms and cytokine-related signaling. Clustering of transcriptional regulation patterns revealed four distinct response pattern groups that directionally pivoted around the 4% O2 tension, or demonstrated coherent ascending/decreasing gene expression patterns in response to diverse oxygen tensions. Immune response and cell cycle/cancer-related signaling pathway transcriptomic subsets were significantly activated with increasing hypoxia, whilst hemostatic and cardiovascular signaling mechanisms were attenuated with increasing hypoxia. Our data indicate that variant O2 tensions induce specific and physiologically-focused transcript regulation patterns that may underpin important physiological mechanisms that connect higher neurological activity to astrocytic function and ambient oxygen environments. These strongly defined patterns demonstrate a strong bias for physiological transcript programs to pivot around the 4% O2 tension, while uni-modal programs that do not, appear more related to pathological actions. The functional interaction of these transcriptional ‘programs’ may serve to regulate the dynamic vascular responsivity of the central nervous system during periods of stress or heightened activity. PMID:21738745

Surgical exclusion of postsurgical pseudoaneurysm of the ascending aorta

PubMed Central

Barik, Ramachandra; Patnaik, Amar Narayana; Kumar, Ravintula Venkata; Mohapatra, Rudra Prasad; Medep, Vikas; Nemani, Lalita

2014-01-01

Pseudoaneurysm of ascending aorta after cardiac surgery is rare in children. We report a case of successful surgical exclusion of ascending aortic pseudoaneurysm in a 15-year-old boy. The neck of the aneurysm was in close proximity to the right coronary artery (RCA). PMID:24987261

ATP mediates flow-induced NO production in thick ascending limbs

PubMed Central

Hong, Nancy J.; Garvin, Jeffrey L.

2012-01-01

Mechanical stimulation caused by increasing flow induces nucleotide release from many cells. Luminal flow and extracellular ATP stimulate production of nitric oxide (NO) in thick ascending limbs. However, the factors that mediate flow-induced NO production are unknown. We hypothesized that luminal flow stimulates thick ascending limb NO production via ATP. We measured NO in isolated, perfused rat thick ascending limbs using the fluorescent dye DAF FM. The rate of increase in dye fluorescence reflects NO accumulation. Increasing luminal flow from 0 to 20 nl/min stimulated NO production from 17 ± 16 to 130 ± 37 arbitrary units (AU)/min (P < 0.02). Increasing flow from 0 to 20 nl/min raised ATP release from 4 ± 1 to 21 ± 6 AU/min (P < 0.04). Hexokinase (10 U/ml) plus glucose, which consumes ATP, completely prevented the measured increase in ATP. Luminal flow did not increase NO production in the presence of luminal and basolateral hexokinase (10 U/ml). When flow was increased with the ATPase apyrase in both luminal and basolateral solutions (5 U/ml), NO levels did not change significantly. The P2 receptor antagonist suramin (300 μmol/l) reduced flow-induced NO production by 83 ± 25% (P < 0.03) when added to both and basolateral sides. Luminal hexokinase decreased flow-induced NO production from 205.6 ± 85.6 to 36.6 ± 118.6 AU/min (P < 0.02). Basolateral hexokinase also reduced flow-induced NO production. The P2X receptor-selective antagonist NF023 (200 μmol/l) prevented flow-induced NO production when added to the basolateral side but not the luminal side. We conclude that ATP mediates flow-induced NO production in the thick ascending limb likely via activation of P2Y receptors in the luminal and P2X receptors in the basolateral membrane. PMID:22496412

Rice Crop Monitoring Using Microwave and Optical Remotely Sensed Image Data

NASA Astrophysics Data System (ADS)

Suga, Y.; Konishi, T.; Takeuchi, S.; Kitano, Y.; Ito, S.

Hiroshima Institute of Technology HIT is operating the direct down-links of microwave and optical satellite data in Japan This study focuses on the validation for rice crop monitoring using microwave and optical remotely sensed image data acquired by satellites referring to ground truth data such as height of crop ratio of crop vegetation cover and leaf area index in the test sites of Japan ENVISAT-1 ASAR data has a capability to capture regularly and to monitor during the rice growing cycle by alternating cross polarization mode images However ASAR data is influenced by several parameters such as landcover structure direction and alignment of rice crop fields in the test sites In this study the validation was carried out combined with microwave and optical satellite image data and ground truth data regarding rice crop fields to investigate the above parameters Multi-temporal multi-direction descending and ascending and multi-angle ASAR alternating cross polarization mode images were used to investigate rice crop growing cycle LANDSAT data were used to detect landcover structure direction and alignment of rice crop fields corresponding to the backscatter of ASAR As the result of this study it was indicated that rice crop growth can be precisely monitored using multiple remotely sensed data and ground truth data considering with spatial spectral temporal and radiometric resolutions

Ascending aortic aneurysm causing hoarse voice: a variant of Ortner's syndrome

PubMed Central

Eccles, Sinan Robert; Banks, John; Kumar, Pankaj

2012-01-01

A 68-year-old man with a persistent hoarse voice was found to have a left vocal cord paralysis. Clinical examination revealed signs consistent with aortic regurgitation. Subsequent investigation revealed an ascending aortic aneurysm. He underwent aortic root and ascending aorta replacement and his hoarseness improved. Ortner's syndrome refers to hoarseness due to recurrent laryngeal nerve palsy secondary to a cardiovascular abnormality. Recurrent laryngeal nerve palsy due to aneurysmal dilation of the ascending aorta is extremely rare, with aneurysms of the aortic arch being a more common cause. PMID:23060380

Biaxial tensile tests of the porcine ascending aorta.

PubMed

Deplano, Valérie; Boufi, Mourad; Boiron, Olivier; Guivier-Curien, Carine; Alimi, Yves; Bertrand, Eric

2016-07-05

One of the aims of this work is to develop an original custom built biaxial set-up to assess mechanical behavior of soft tissues. Stretch controlled biaxial tensile tests are performed and stereoscopic digital image correlation (SDIC) is implemented to measure the 3D components of the generated displacements. Using this experimental device, the main goal is to investigate the mechanical behavior of porcine ascending aorta in the more general context of human ascending aorta pathologies. The results highlight that (i) SDIC arrangement allows accurate assessment of displacements and so stress strain curves, (ii) porcine ascending aorta has a nearly linear and anisotropic mechanical behavior until 30% of strain, (iii) porcine ascending aorta is stiffer in the circumferential direction than in the longitudinal one, (iv) the material coefficient representing the interaction between the two loading directions is thickness dependent, (v) taking into account the variability of the samples the stress values are independent of the stretch rate in the range of values from 10(-3) to 10(-1)s(-1) and finally, (vi) unlike other segments of the aorta, 4-month-old pigs ascending aorta is definitely not a relevant model to investigate the mechanical behavior of the human ascending aorta. Copyright © 2016 Elsevier Ltd. All rights reserved.

Inventory and state of activity of rockglaciers in the Ile and Kungöy Ranges of Northern Tien Shan from satellite SAR interferometry

NASA Astrophysics Data System (ADS)

Strozzi, Tazio; Caduff, Rafael; Kääb, Andreas; Bolch, Tobias

2017-04-01

The best visual expression of mountain permafrost are rockglaciers, which, in contrast to the permafrost itself, can be mapped and monitored directly using remotely sensed data. Studies carried out in various parts of the European Alps have shown surface acceleration of rockglaciers and even destabilization of several such landforms over the two last decades, potentially related to the changing permafrost creep conditions. Changes in rockglacier motion are therefore believed to be the most indicative short- to medium-term response of rockglaciers to environmental changes and thus an indicator of mountain permafrost conditions in general. The ESA DUE GlobPermafrost project develops, validates and implements EO products to support research communities and international organizations in their work on better understanding permafrost characteristics and dynamics. Within this project we are building up a worldwide long-term monitoring network of active rockglacier motion investigated using remote sensing techniques. All sites are analysed through a uniform set of data and methods, and results are thus comparable. In order to quantify the rate of movement and the relative changes over time we consider two remote sensing methods: (i) matching of repeat optical data and (ii) satellite radar interferometry. In this contribution, we focus on the potential of recent high spatial resolution SAR data for the analysis of periglacial processes in mountain environments with special attention to the Ile and Kungöy Ranges of Northern Tien Shan at the border between Kazakhstan and Kyrgyzstan, an area which contains a high number of large and comparably fast (> 1m/yr) rockglaciers and is of interest as dry-season water resource and source of natural hazards. As demonstrated in the past with investigations conducted in the Swiss Alps, the visual analysis of differential SAR interferograms can be employed for the rough estimation of the surface deformation rates of rockglaciers and other slope instabilities into different classes (e.g. cm/day, dm/month, cm/month and cm/yr). More sophisticated SAR interferometric approaches like Persistent Scatterer Interferometry (PSI) or Short Baseline Interferometry (SBAS) are only able to detect points moving with velocities below a few cm/yr respectively several dm/yr in the Line-Of-Sight (LOS) direction, because of phase unwrapping issues. For our analysis in the Tien Shan we considered SAR interferograms with short baselines and acquisition time intervals between 1 day and approximately one year. Satellite images from the ERS-1/2 tandem mission in 1998-1999, ALOS-1 PALSAR-1 between 2006-2010 (46 days nominal repeat cycle), ALOS-2 PALSAR-2 between 2014 and 2016 (14 days nominal repeat cycle), and Sentinel-1 between 2015 and 2016 (12 days nominal repeat cycle) were used. Images acquired along both ascending and descending geometries and during summer (snow-free) and winter (frozen snow) conditions were employed. For topographic reference and orthorectification we computed in-house a Digital Elevation Model from TanDEM-X acquisitions of ascending and descending orbits. Phase unwrapping to derive the LOS displacement was attempted only locally for selected landforms with a moderate (e.g. < 50 cm/yr) rate of motion. Our inventory of rockglaciers and other periglacial processes in the Northern Tien Shan includes so far more than 500 objects over an area of more than 3000 km2. In future, our inventory will be compared to other existing inventories compiled in field or with air photos. In addition, the long-term monitoring of rockglacier motion will be performed taking advantage of the synergies between repeat optical and radar satellite data. The combined approach is useful for the confirmation of the activity, filling spatial and/or temporal gaps, computing the historical fast motion of rockglaciers from optical data and the slow motion from SAR interferometry, and to compare multi-annual rates of motion (optical data) with seasonal activities (SAR interferometry).

Sleep neurobiology from a clinical perspective.

PubMed

España, Rodrigo A; Scammell, Thomas E

2011-07-01

Many neurochemical systems interact to generate wakefulness and sleep. Wakefulness is promoted by neurons in the pons, midbrain, and posterior hypothalamus that produce acetylcholine, norepinephrine, dopamine, serotonin, histamine, and orexin/hypocretin. Most of these ascending arousal systems diffusely activate the cortex and other forebrain targets. NREM sleep is mainly driven by neurons in the preoptic area that inhibit the ascending arousal systems, while REM sleep is regulated primarily by neurons in the pons, with additional influence arising in the hypothalamus. Mutual inhibition between these wake- and sleep-regulating regions likely helps generate full wakefulness and sleep with rapid transitions between states. This up-to-date review of these systems should allow clinicians and researchers to better understand the effects of drugs, lesions, and neurologic disease on sleep and wakefulness.

Limitations of oxygen uptake and leg muscle activity during ascending evacuation in stairways.

PubMed

Halder, Amitava; Kuklane, Kalev; Gao, Chuansi; Miller, Michael; Delin, Mattias; Norén, Johan; Fridolf, Karl

2018-01-01

Stair ascending performance is critical during evacuation from buildings and underground infrastructures. Healthy subjects performed self-paced ascent in three settings: 13 floor building, 31 floor building, 33 m stationary subway escalator. To investigate leg muscle and cardiorespiratory capacities and how they constrain performance, oxygen uptake (VO 2 ), heart rate (HR) and ascending speed were measured in all three; electromyography (EMG) in the first two. The VO 2 and HR ranged from 89 to 96% of the maximum capacity reported in the literature. The average highest VO 2 and HR ranged from 39 to 41 mL·kg -1 ·min -1 and 162 to 174 b·min -1 , respectively. The subjects were able to sustain their initial preferred maximum pace for a short duration, while the average step rate was 92-95 steps·min -1 . In average, VO 2 reached relatively stable values at ≈37 mL·kg -1 ·min -1 . EMG amplitudes decreased significantly and frequencies were unchanged. Speed reductions indicate that climbing capacity declined in the process of fatigue development. In the two buildings, the reduction of muscle power allowed the subjects to extend their tolerance and complete ascents in the 48 m and 109 m high stairways in 2.9 and 7.8 min, respectively. Muscle activity interpretation squares were developed and proved advantageous to observe fatigue and recovery over time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Carbachol-induced volume adaptation in mouse bladder and length adaptation via rhythmic contraction in rabbit detrusor.

PubMed

Speich, John E; Wilson, Cameron W; Almasri, Atheer M; Southern, Jordan B; Klausner, Adam P; Ratz, Paul H

2012-10-01

The length-tension (L-T) relationships in rabbit detrusor smooth muscle (DSM) are similar to those in vascular and airway smooth muscles and exhibit short-term length adaptation characterized by L-T curves that shift along the length axis as a function of activation and strain history. In contrast to skeletal muscle, the length-active tension (L-T(a)) curve for rabbit DSM strips does not have a unique peak tension value with a single ascending and descending limb. Instead, DSM can exhibit multiple ascending and descending limbs, and repeated KCl-induced contractions at a particular muscle length on an ascending or descending limb display increasingly greater tension. In the present study, mouse bladder strips with and without urothelium exhibited KCl-induced and carbachol-induced length adaptation, and the pressure-volume relationship in mouse whole bladder displayed short-term volume adaptation. Finally, prostaglandin-E(2)-induced low-level rhythmic contraction produced length adaptation in rabbit DSM strips. A likely role of length adaptation during bladder filling is to prepare DSM cells to contract efficiently over a broad range of volumes. Mammalian bladders exhibit spontaneous rhythmic contraction (SRC) during the filling phase and SRC is elevated in humans with overactive bladder (OAB). The present data identify a potential physiological role for SRC in bladder adaptation and motivate the investigation of a potential link between short-term volume adaptation and OAB with impaired contractility.

The ascending reticular activating system from pontine reticular formation to the hypothalamus in the human brain: a diffusion tensor imaging study.

PubMed

Jang, Sung Ho; Kwon, Hyeok Gyu

2015-03-17

The ascending reticular activating system (ARAS) is responsible for regulation of consciousness. Precise evaluation of the ARAS is important for diagnosis and management of patients with impaired consciousness. In the current study, we attempted to reconstruct the portion of the ARAS from the pontine reticular formation (RF) to the hypothalamus in normal subjects, using diffusion tensor imaging (DTI). A total of 31 healthy subjects were recruited for this study. DTI scanning was performed using 1.5-T, and the ARAS from the pontine RF to the hypothalamus was reconstructed. Values of fractional anisotropy, mean diffusivity, and tract volume of the ARAS from the pontine RF to the hypothalamus were measured. In all subjects, the ARAS from the pontine RF to the hypothalamus originated from the RF at the level of the mid-pons, where the trigeminal nerve could be seen, ascended through the periaqueductal gray matter of the midbrain anterolaterally to the anterior commissure level, and then terminated into the hypothalamus. No significant differences in DTI parameters were observed between the left and right hemispheres and between males and females (p<0.05). We identified the ARAS between the pontine RF and the hypothalamus in normal subjects using DTI. We believe that the reconstruction methodology and the results of this study would be useful to clinicians involved in the care of patients with impaired consciousness and researchers in studies of the ARAS. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The Role of Wave Cyclones in Transporting Boundary Layer Air to the Free Troposphere During the Spring 2001 NASA / TRACE-P Experiment

NASA Technical Reports Server (NTRS)

Fuelberg, Henry E.; Hannan, J. R.; Crawford, J. H.; Sachse, G. W.; Blake, D. R.

2003-01-01

Transport of boundary layer air to the free troposphere by cyclones during NASA's Transport and Chemical Evolution over the Pacific (TRACE-P) experiment is investigated. Airstreams responsible for boundary layer venting are diagnosed using results from a high-resolution meteorological model (MM5) together with in situ and remotely sensed chemical data. Hourly wind data from the MM5 are used to calculate three-dimensional grids of backward air trajectories. A reverse domain filling (RDF) technique then is employed to examine the characteristics of airstreams over the computational domain, and to isolate airstreams ascending from the boundary layer to the free troposphere during the previous 36 hours. Two cases are examined in detail. Results show that airstreams responsible for venting the boundary layer differ considerably from those described by classic conceptual models and in the recent literature. In addition, airstreams sampled by the TRACE-P aircraft are found to exhibit large variability in chemical concentrations. This variability is due to differences in the boundary layer histories of individual airstreams with respect to anthropogenic sources over continental Asia and Japan. Complex interactions between successive wave cyclones also are found to be important in determining the chemical composition of the airstreams. Particularly important is the process of post-cold frontal boundary layer air being rapidly transported offshore and recirculated into ascending airstreams of upstream cyclones.

Spontaneous rupture of the ascending aorta.

PubMed

Bin Mahmood, Syed Usman; Ulrich, Andrew; Safdar, Basmah; Geirsson, Arnar; Mangi, Abeel A

2018-02-01

Nontraumatic, spontaneous rupture of the ascending aorta is rare and the etiology is largely unknown. We reviewed seven patients from our institution, with no known aortic disease or hereditary connective tissue disorder that presented with spontaneous ascending aortic rupture from 2012 to 2017. Most patients presented with non-radiating chest pain along with hypertension (71.4%). The mean ascending aortic diameter at rupture was 4.60 ± 0.62 cm. The median door-to-operating room time was 2.58 h, resulting from effective implementation of an aortic emergency protocol. There were no operative mortalities. In patients with ascending aortic rupture, aortic diameter may not always correlate with the risk of rupture. Rapid diagnosis combined with a multidisciplinary approach is vital for the successful management of these high-risk patients. © 2018 Wiley Periodicals, Inc.

Temporal integration at consecutive processing stages in the auditory pathway of the grasshopper.

PubMed

Wirtssohn, Sarah; Ronacher, Bernhard

2015-04-01

Temporal integration in the auditory system of locusts was quantified by presenting single clicks and click pairs while performing intracellular recordings. Auditory neurons were studied at three processing stages, which form a feed-forward network in the metathoracic ganglion. Receptor neurons and most first-order interneurons ("local neurons") encode the signal envelope, while second-order interneurons ("ascending neurons") tend to extract more complex, behaviorally relevant sound features. In different neuron types of the auditory pathway we found three response types: no significant temporal integration (some ascending neurons), leaky energy integration (receptor neurons and some local neurons), and facilitatory processes (some local and ascending neurons). The receptor neurons integrated input over very short time windows (<2 ms). Temporal integration on longer time scales was found at subsequent processing stages, indicative of within-neuron computations and network activity. These different strategies, realized at separate processing stages and in parallel neuronal pathways within one processing stage, could enable the grasshopper's auditory system to evaluate longer time windows and thus to implement temporal filters, while at the same time maintaining a high temporal resolution. Copyright © 2015 the American Physiological Society.

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

Ahn, Cheol Hyoun; Hee Kim, So; Gu Yun, Myeong

In this study, we proposed the artificially designed channel structure in oxide thin-film transistors (TFTs) called a “step-composition gradient channel.” We demonstrated Al step-composition gradient Al-Zn-O (AZO) channel structures consisting of three AZO layers with different Al contents. The effects of stacking sequence in the step-composition gradient channel on performance and electrical stability of bottom-gate TFT devices were investigated with two channels of inverse stacking order (ascending/descending step-composition). The TFT with ascending step-composition channel structure (5 → 10 → 14 at. % Al composition) showed relatively negative threshold voltage (−3.7 V) and good instability characteristics with a reduced threshold voltage shift (Δmore » 1.4 V), which was related to the alignment of the conduction band off-set within the channel layer depending on the Al contents. Finally, the reduced Al composition in the initial layer of ascending step-composition channel resulted in the best field effect mobility of 4.5 cm{sup 2}/V s. We presented a unique active layer of the “step-composition gradient channel” in the oxide TFTs and explained the mechanism of adequate channel design.« less

Comparative Analysis of Alternative Spectral Bands of CO2 and O2 for the Sensing of CO2 Mixing Ratios

NASA Technical Reports Server (NTRS)

Pliutau, Denis; Prasad, Narasimha S.

2013-01-01

We performed comparative studies to establish favorable spectral regions and measurement wavelength combinations in alternative bands of CO2 and O2, for the sensing of CO2 mixing ratios (XCO2) in missions such as ASCENDS. The analysis employed several simulation approaches including separate layers calculations based on pre-analyzed atmospheric data from the modern-era retrospective analysis for research and applications (MERRA), and the line-byline radiative transfer model (LBLRTM) to obtain achievable accuracy estimates as a function of altitude and for the total path over an annual span of variations in atmospheric parameters. Separate layer error estimates also allowed investigation of the uncertainties in the weighting functions at varying altitudes and atmospheric conditions. The parameters influencing the measurement accuracy were analyzed independently and included temperature sensitivity, water vapor interferences, selection of favorable weighting functions, excitations wavelength stabilities and other factors. The results were used to identify favorable spectral regions and combinations of on / off line wavelengths leading to reductions in interferences and the improved total accuracy.

Biomechanical Analyses of Stair-climbing while Dual-tasking

PubMed Central

Vallabhajosula, Srikant; Tan, Chi Wei; Mukherjee, Mukul; Davidson, Austin J.; Stergiou, Nicholas

2015-01-01

Stair-climbing while doing a concurrent task like talking or holding an object is a common activity of daily living which poses high risk for falls. While biomechanical analyses of overground walking during dual-tasking have been studied extensively, little is known on the biomechanics of stair-climbing while dual-tasking. We sought to determine the impact of performing a concurrent cognitive or motor task during stair-climbing. We hypothesized that a concurrent cognitive task will have a greater impact on stair climbing performance compared to a concurrent motor task and that this impact will be greater on a higher-level step. Ten healthy young adults performed 10 trials of stair-climbing each under four conditions: stair ascending only, stair ascending and performing subtraction of serial sevens from a three-digit number, stair ascending and carrying an empty opaque box and stair ascending, performing subtraction of serial sevens from a random three-digit number and carrying an empty opaque box. Kinematics (lower extremity joint angles and minimum toe clearance) and kinetics (ground reaction forces and joint moments and powers) data were collected. We found that a concurrent cognitive task impacted kinetics but not kinematics of stair-climbing. The effect of dual-tasking during stair ascent also seemed to vary based on the different phases of stair ascent stance and seem to have greater impact as one climbs higher. Overall, the results of the current study suggest that the association between the executive functioning and motor task (like gait) becomes stronger as the level of complexity of the motor task increases. PMID:25773590

Fully automated contour detection of the ascending aorta in cardiac 2D phase-contrast MRI.

PubMed

Codari, Marina; Scarabello, Marco; Secchi, Francesco; Sforza, Chiarella; Baselli, Giuseppe; Sardanelli, Francesco

2018-04-01

In this study we proposed a fully automated method for localizing and segmenting the ascending aortic lumen with phase-contrast magnetic resonance imaging (PC-MRI). Twenty-five phase-contrast series were randomly selected out of a large population dataset of patients whose cardiac MRI examination, performed from September 2008 to October 2013, was unremarkable. The local Ethical Committee approved this retrospective study. The ascending aorta was automatically identified on each phase of the cardiac cycle using a priori knowledge of aortic geometry. The frame that maximized the area, eccentricity, and solidity parameters was chosen for unsupervised initialization. Aortic segmentation was performed on each frame using active contouring without edges techniques. The entire algorithm was developed using Matlab R2016b. To validate the proposed method, the manual segmentation performed by a highly experienced operator was used. Dice similarity coefficient, Bland-Altman analysis, and Pearson's correlation coefficient were used as performance metrics. Comparing automated and manual segmentation of the aortic lumen on 714 images, Bland-Altman analysis showed a bias of -6.68mm 2 , a coefficient of repeatability of 91.22mm 2 , a mean area measurement of 581.40mm 2 , and a reproducibility of 85%. Automated and manual segmentation were highly correlated (R=0.98). The Dice similarity coefficient versus the manual reference standard was 94.6±2.1% (mean±standard deviation). A fully automated and robust method for identification and segmentation of ascending aorta on PC-MRI was developed. Its application on patients with a variety of pathologic conditions is advisable. Copyright © 2017 Elsevier Inc. All rights reserved.

Structure-activity relationships of selected phenazines against Mycobacterium leprae in vitro.

PubMed Central

Franzblau, S G; O'Sullivan, J F

1988-01-01

Structure-activity relationships of phenazines against Mycobacterium leprae were investigated by using an in vitro radiorespirometric assay. In general, activity in ascending order was observed in compounds containing no chlorine atoms, a monochlorinated phenazine nucleus, and chlorines in the para positions of both the anilino and phenyl rings. The most active compounds contained a 2,2,6,6-tetramethylpiperidine substitution at the imino nitrogen. Most of these chlorinated phenazines were considerably more active in vitro than clofazimine (B663). PMID:3056241

Decreased expression of fibulin-4 in aortic wall of aortic dissection.

PubMed

Huawei, P; Qian, C; Chuan, T; Lei, L; Laing, W; Wenlong, X; Wenzhi, L

2014-02-01

In this research, we will examine the expression of Fibulin-4 in aortic wall to find out its role in aortic dissection development. The samples of aortic wall were obtained from 10 patients operated for acute ascending aortic dissection and five patients for chronic ascending aortic dissection. Another 15 pieces of samples from patients who had coronary artery bypass were as controls. The aortic samples were stained with aldehyde magenta dyeing to evaluate the arrangement of elastic fibers. The Fibulin-4 protein and mRNA expression were both determined by Western blot and realtime quantitative polymerase chain reaction. Compared with the control group, both in acute and chronic ascending aortic dissection, elastic fiber fragments increased and the expression of fibulin-4 protein significantly decreased (P= 0.045 < 0.05). The level of fibulin-4 mRNA decreased in acute ascending aortic dissection (P= 0.034 < 0.05), while it increased in chronic ascending aortic dissection (P=0.004 < 0.05). The increased amounts of elastic fiber fragments were negatively correlated with the expression of fibulin-4 mRNA in acute ascending aortic dissection. In conclusion, in aortic wall of ascending aortic dissection, the expression of fibulin-4 protein decreased and the expression of fibulin-4 mRNA was abnormal. Fibulin-4 may play an important role in the pathogenesis of aortic dissection.

Catching a floating thrombus; a case report on the treatment of a large thrombus in the ascending aorta.

PubMed

de Maat, Gijs Eduard; Vigano, Giorgio; Mariani, Massimo Alessandro; Natour, Ehsan

2017-05-19

The ascending aorta is an uncommon site for non-infective thrombus. In non-aneurysmal and non-atherosclerotic vessels this condition becomes extremely rare, while it represents a source of potential cerebral and peripheral embolic events. Currently, there is no consensus in the guidelines on how to treat a free floating thrombus in ascending aorta, therefore we present our decision making process and therapeutic strategy. A healthy 48-year-old man was hospital admitted with acute abdominal pain. CT-scan showed a right renal embolism in presence of a defect in the distal ascending aorta suggestive for thrombus. After heart team discussion the patient was scheduled for surgery and successfully underwent an emergent thrombus removal. Also, owing to multiple aortic wall insertions, the ascending aorta was replaced. The patient's recovery was uneventful and histological examination showed no signs of connective tissue disorders of aortic wall while confirmed the thrombotic nature of the mass. We present a patient with a floating thrombus in the ascending aorta who underwent an ascending aorta replacement. While angio-CT scan led to a prompt diagnosis, intraoperative epi-aortic echocardiography allowed to define precise location of thrombus, minimizing operative risk. This case demonstrates that multi-disciplinary heart team discussion is essential to define a successful strategy, that surgical treatment is feasible with specific tools such as epi-aortic echocardiography.

Mapping Muscles Activation to Force Perception during Unloading

PubMed Central

Toma, Simone; Lacquaniti, Francesco

2016-01-01

It has been largely proved that while judging a force humans mainly rely on the motor commands produced to interact with that force (i.e., sense of effort). Despite of a large bulk of previous investigations interested in understanding the contributions of the descending and ascending signals in force perception, very few attempts have been made to link a measure of neural output (i.e., EMG) to the psychophysical performance. Indeed, the amount of correlation between EMG activity and perceptual decisions can be interpreted as an estimate of the contribution of central signals involved in the sensation of force. In this study we investigated this correlation by measuring the muscular activity of eight arm muscles while participants performed a quasi-isometric force detection task. Here we showed a method to quantitatively describe muscular activity (“muscle-metric function”) that was directly comparable to the description of the participants' psychophysical decisions about the stimulus force. We observed that under our experimental conditions, muscle-metric absolute thresholds and the shape of the muscle-metric curves were closely related to those provided by the psychophysics. In fact a global measure of the muscles considered was able to predict approximately 60% of the perceptual decisions total variance. Moreover the inter-subjects differences in psychophysical sensitivity showed high correlation with both participants' muscles sensitivity and participants' joint torques. Overall, our findings gave insights into both the role played by the corticospinal motor commands while performing a force detection task and the influence of the gravitational muscular torque on the estimation of vertical forces. PMID:27032087

Mapping Muscles Activation to Force Perception during Unloading.

PubMed

Toma, Simone; Lacquaniti, Francesco

2016-01-01

It has been largely proved that while judging a force humans mainly rely on the motor commands produced to interact with that force (i.e., sense of effort). Despite of a large bulk of previous investigations interested in understanding the contributions of the descending and ascending signals in force perception, very few attempts have been made to link a measure of neural output (i.e., EMG) to the psychophysical performance. Indeed, the amount of correlation between EMG activity and perceptual decisions can be interpreted as an estimate of the contribution of central signals involved in the sensation of force. In this study we investigated this correlation by measuring the muscular activity of eight arm muscles while participants performed a quasi-isometric force detection task. Here we showed a method to quantitatively describe muscular activity ("muscle-metric function") that was directly comparable to the description of the participants' psychophysical decisions about the stimulus force. We observed that under our experimental conditions, muscle-metric absolute thresholds and the shape of the muscle-metric curves were closely related to those provided by the psychophysics. In fact a global measure of the muscles considered was able to predict approximately 60% of the perceptual decisions total variance. Moreover the inter-subjects differences in psychophysical sensitivity showed high correlation with both participants' muscles sensitivity and participants' joint torques. Overall, our findings gave insights into both the role played by the corticospinal motor commands while performing a force detection task and the influence of the gravitational muscular torque on the estimation of vertical forces.

Stenting of the ascending aorta revisited.

PubMed

Moiduddin, Nasser J; Rios, Rodrigo; El-Said, Howaida; Moore, John W

2017-10-01

Despite few institutions stenting the ascending aorta, it has been discouraged because of the proximity of the aortic valve, the coronary artery orifices, and the aortic arch branches. We describe a small case series of patients having acquired stenosis of the ascending that was relieved successfully by stenting. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Neuropsychiatry of complex visual hallucinations.

PubMed

Mocellin, Ramon; Walterfang, Mark; Velakoulis, Dennis

2006-09-01

To describe the phenomenology and pathophysiology of complex visual hallucinations (CVH) in various organic states, in particular Charles Bonnet syndrome and peduncular hallucinosis. Three cases of CVH in the setting of pontine infarction, thalamic infarction and temporoparietal epileptiform activity are presented and the available psychiatric, neurological and biological literature on the structures of the central nervous system involved in producing hallucinatory states is reviewed. Complex visual hallucinations can arise from a variety of processes involving the retinogeniculocalcarine tract, or ascending brainstem modulatory structures. The cortical activity responsible for hallucinations results from altered or reduced input into these regions, or a loss of ascending inhibition of their afferent pathways. A significant degree of overlaps exists between the concepts of Charles Bonnet syndrome and peduncular hallucinosis. The fluidity of these eponymous syndromes reduces their validity and meaning, and may result in an inappropriate attribution of the underlying pathology. An understanding of how differing pathologies may produce CVH allows for the appropriate tailoring of treatment, depending on the site and nature of the lesion and content of perceptual disturbance.

A penetrating atherosclerotic ulcer rupture in the ascending aorta with hemopericardium: a case report.

PubMed

Liu, Yuan-Hao; Ke, Hung-Yen; Lin, Yi-Chang; Tsai, Chien-Sung

2016-07-11

Acute aortic syndrome, including classic aortic dissection, intramural aortic hematoma, and penetrating atherosclerotic ulcer (PAU), is a term used to describe a group of conditions with similar clinical symptoms, but with different pathophysiological mechanisms. PAU is a lesion that penetrates the internal elastic lamina through the media. It is usually located in the descending aorta and rarely observed in the ascending aorta. A 76-year-old man with a history of essential hypertension was brought to the emergency department (ED) because of a sudden-onset chest pain at rest. He had not been taking his medication as ordered. His vital signs in the ED were a blood pressure of 82/60 mmHg, heart rate of 158 beats per min, respiratory rate of 22 breaths per min, and a body temperature of 37.2 °C. An electrocardiogram did not show an ST segment elevation, and cardiac enzymes were within normal limits. No widening mediastinum was found on chest radiography, but a large pericardial effusion with an impending cardiac tamponade was revealed on echocardiography. The diagnosis of PAU rupture in the ascending aorta with hemopericardium was made with chest computed tomography. An emergent sternotomy and ascending aorta reconstruction were performed. A ruptured ulcerative plaque through the intima to the adventitia without flap dissection in the ascending aorta was confirmed. The patient was discharged 18 days after the operation. Although PAU in the ascending aorta is uncommon, it is commonly lethal when it ruptures. With the current advances in endovascular techniques and devices, endovascular repair of PAU in the ascending aorta is currently recommended only for high-risk patients unsuitable for open repair. However, we anticipate that endovascular repair may become feasible in patients with PAU in the ascending aorta in the future.

Pulmonary arterial hypertension in children: diagnosis using ratio of main pulmonary artery to ascending aorta diameter as determined by multi-detector computed tomography.

PubMed

Caro-Domínguez, Pablo; Compton, Gregory; Humpl, Tilman; Manson, David E

2016-09-01

The ratio of the transverse diameter of the main pulmonary artery (MPA) to ascending aorta as determined at multi-detector CT is a tool that can be used to assess the pulmonary arterial size in cases of pulmonary arterial hypertension in children. To establish a ratio of MPA to ascending aorta diameter using multi-detector CT imaging suggestive of pulmonary arterial hypertension in children. We hypothesize that a defined ratio of MPA to ascending aorta is identifiable on multi-detector CT and that higher ratios can be used to reliably diagnose the presence of pulmonary arterial hypertension in children. We calculated the multi-detector CT ratio of MPA to ascending aorta diameter in 44 children with documented pulmonary arterial hypertension by right heart catheterization and in 44 age- and gender-matched control children with no predisposing factors for pulmonary arterial hypertension. We compared this multi-detector-CT-determined ratio with the MPA pressure in the study group, as well as with the ratio of MPA to ascending aorta in the control group. A threshold ratio value was calculated to accurately identify children with pulmonary arterial hypertension. Children with documented primary pulmonary arterial hypertension have a significantly higher ratio of MPA to ascending aorta (1.46) than children without pulmonary arterial hypertension (1.11). A ratio of 1.3 carries a positive likelihood of 34 and a positive predictive value of 97% for the diagnosis of pulmonary arterial hypertension. The pulmonary arteries were larger in children with pulmonary arterial hypertension than in a control group of normal children. A CT-measured ratio of MPA to ascending aorta of 1.3 should raise the suspicion of pulmonary arterial hypertension in children.

Complications at the Proximal Landing Zone of Endovascular Stent Grafts Deployed in Surgically Replaced Ascending Aorta.

PubMed

Kotha, Vamshi K; Herget, Eric J; Appoo, Jehangir J

2016-11-01

The ascending aorta, with its hostile angulations and forces, is the next frontier in the evolution of endovascular surgery. Type II hybrid arch repair, involving surgical replacement of the ascending aorta, arch debranching, and stent graft deployment in the ascending aortic graft, offers an opportunity to study the behavior of an endovascular prosthesis in the ascending aorta. We report complications seen at the proximal landing zone after type II hybrid arch repair. A dedicated imaging protocol was used to monitor 20 consecutive patients who underwent type II hybrid arch repair at a single center from June 2009 to July 2014. Mean age was 66 years (range, 47 to 82 years). Mean imaging follow-up was 34 months (range, 12 to 64 months). There was 1 operative death (5%). Bird beaking (>5 mm of nonapposition) of the stent graft at the proximal landing zone occurred in 12 patients, and >20 mm of bird beaking occurred in 7 patients. Proximal landing zone complications occurred in 4 patients (20%), comprising 2 type Ia endoleaks, 1 graft migration, and 1 graft infolding detected on postoperative days 4, 11, 5, and 755, respectively. Three patients underwent endovascular reintervention for proximal landing zone complications. There were no late deaths. Thoracic aortic stent grafts may be prone to proximal landing zone complications when deployed in the ascending aorta. Bird beaking is common when endografts are deployed in the Dacron (DuPont, Wilmington, DE) ascending aorta. Angulation issues will likely need to be overcome by stent graft refinement to enable future closed chest approaches to the ascending aorta. Copyright © 2016 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Trigeminal, Visceral and Vestibular Inputs May Improve Cognitive Functions by Acting through the Locus Coeruleus and the Ascending Reticular Activating System: A New Hypothesis

PubMed Central

De Cicco, Vincenzo; Tramonti Fantozzi, Maria P.; Cataldo, Enrico; Barresi, Massimo; Bruschini, Luca; Faraguna, Ugo; Manzoni, Diego

2018-01-01

It is known that sensory signals sustain the background discharge of the ascending reticular activating system (ARAS) which includes the noradrenergic locus coeruleus (LC) neurons and controls the level of attention and alertness. Moreover, LC neurons influence brain metabolic activity, gene expression and brain inflammatory processes. As a consequence of the sensory control of ARAS/LC, stimulation of a sensory channel may potential influence neuronal activity and trophic state all over the brain, supporting cognitive functions and exerting a neuroprotective action. On the other hand, an imbalance of the same input on the two sides may lead to an asymmetric hemispheric excitability, leading to an impairment in cognitive functions. Among the inputs that may drive LC neurons and ARAS, those arising from the trigeminal region, from visceral organs and, possibly, from the vestibular system seem to be particularly relevant in regulating their activity. The trigeminal, visceral and vestibular control of ARAS/LC activity may explain why these input signals: (1) affect sensorimotor and cognitive functions which are not directly related to their specific informational content; and (2) are effective in relieving the symptoms of some brain pathologies, thus prompting peripheral activation of these input systems as a complementary approach for the treatment of cognitive impairments and neurodegenerative disorders. PMID:29358907

Aortic valve stenosis and aortic diameters determine the extent of increased wall shear stress in bicuspid aortic valve disease.

PubMed

Farag, Emile S; van Ooij, Pim; Planken, R Nils; Dukker, Kayleigh C P; de Heer, Frederiek; Bouma, Berto J; Robbers-Visser, Danielle; Groenink, Maarten; Nederveen, Aart J; de Mol, Bas A J M; Kluin, Jolanda; Boekholdt, S Matthijs

2018-02-16

Use of 4-dimensional flow magnetic resonance imaging (4D-flow MRI) derived wall shear stress (WSS) heat maps enables identification of regions in the ascending aorta with increased WSS. These regions are subject to dysregulation of the extracellular matrix and elastic fiber degeneration, which is associated with aortic dilatation and dissection. To evaluate the effect of the presence of aortic valve stenosis and the aortic diameter on the peak WSS and surface area of increased WSS in the ascending aorta. Prospective. In all, 48 bicuspid aortic valve (BAV) patients (38.1 ± 12.4 years) and 25 age- and gender-matched healthy individuals. Time-resolved 3D phase contrast MRI with three-directional velocity encoding at 3.0T. Peak systolic velocity, WSS, and aortic diameters were assessed in the ascending aorta and 3D heat maps were used to identify regions with elevated WSS. Comparisons between groups were performed by t-tests. Correlations were investigated by univariate and multivariate regression analysis. Elevated WSS was present in 15 ± 11% (range; 1-35%) of the surface area of the ascending aorta of BAV patients with aortic valve stenosis (AS) (n = 10) and in 6 ± 8% (range; 0-31%) of the ascending aorta of BAV patients without AS (P = 0.005). The mid-ascending aortic diameter negatively correlated with the peak ascending aortic WSS (R = -0.413, P = 0.004) and the surface area of elevated WSS (R = -0.419, P = 0.003). Multivariate linear regression analysis yielded that the height of peak WSS and the amount of elevated WSS depended individually on the presence of aortic valve stenosis and the diameter of the ascending aorta. The extent of increased WSS in the ascending aorta of BAV patients depends on the presence of aortic valve stenosis and aortic dilatation and is most pronounced in the presence of AS and a nondilated ascending aorta. 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018. © 2018 The Authors Journal of Magnetic Resonance Imaging published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

The effect of proximal anastomosis on the expansion rate of a dilated ascending aorta in coronary artery bypass surgery: a prospective study

PubMed Central

Balcı, Ahmet Yavuz; Vural, Unsal; Özdemir, MD Fatih; Kızılay, Mehmet; Şenocak, Mutlu; Kayacıoğlu, Ilyas; Yekeler, Ibrahim; Aksoy, Rezan; Satılmış,, Seçkin; Şaşkın, Huseyin

2017-01-01

Summary Background: This study was designed to determine the short- and long-term effects of proximal aortic anastomosis, performed during isolated coronary artery bypass grafting (CABG) in patients with dilatation of the ascending aorta who did not require surgical intervention. Methods: The study was performed on 192 (38 female and 160 male patients; mean age, 62.1 ± 9.2 years; range, 42–80 years) patients with dilatation of the ascending aorta who underwent CABG surgery between 1 June 2006 and 31 May 2014. In group 1 (n = 114), the saphenous vein and left internal mammarian artery grafts were used, and proximal anastomosis was performed on the ascending aorta. In group 2 (n = 78), left and right internal mammarian artery grafts were used, and proximal aortic anastomosis was not performed. Pre-operatively and in the first and third years postoperatively, the ascending aortic diameter was measured and recorded using transthoracic echocardiography at four different regions (annulus, sinus of Valsalva, sinotubular junction and tubular aorta). Results: A statistically significant difference was found between the groups for the number of grafts used and the duration of aortic cross-clamping and cardiopulmonary bypass. No significant intergroup difference was seen for the mean diameter of the ascending aorta (p > 0.05). Annual changes in the aortic diameter were found to be extremely significantly different in both groups (p = 0.0001). Mean values of the aortic diameter at the level of the sinotubular junction and tubular ascending aorta, mean aortic diameters (p = 0.002 and p = 0.0001, respectively), annual increase in diameter (p = 0.0001 and p = 0.0001, respectively), and mean annual difference in diameter (p = 0.0001 and p = 0.0001, respectively) at one and three years postoperatively were statistically significantly different between the groups. Conclusion: In patients with ascending aortic dilatation who did not require surgical intervention and who had proximal anastomosis of the ascending aorta and underwent only CABG, we detected statistically significant increases in the diameter of the sinotubular junction and tubular aorta up to three years postoperatively. PMID:27701487

International experience with endovascular therapy of the ascending aorta with a dedicated endograft.

PubMed

Tsilimparis, Nikolaos; Debus, E Sebastian; Oderich, Gustavo S; Haulon, Stephan; Terp, Kim Allan; Roeder, Blayne; Detter, Christian; Kölbel, Tilo

2016-06-01

The objective of this study was to evaluate the safety and feasibility of a novel stent graft specifically designed for treatment of the ascending aorta. This was a multicenter, retrospective analysis of all consecutive patients treated with the dedicated Zenith Ascend TAA Endovascular Graft (William Cook Europe, Bjaeverskov, Denmark) for pathologic processes requiring stent grafting of the ascending aorta. The graft is short (6.5 cm), with a delivery system designed for transfemoral placement in the ascending aorta. In 10 patients (five men; age, 67 years; range, 26-90 years), the Zenith Ascend graft was implanted for the following indications: dissection (n = 5) and aneurysm (n = 4) of the ascending aorta and fixation of an intraprocedural dislocated aortic valve (n = 1). All patients were judged to be at high risk for open surgery (nine patients were classified as American Society of Anesthesiologists class 3 or class 4). A transfemoral approach was selected in eight cases and a transapical approach in two. All endografts were successfully deployed without intraoperative adverse events at the targeted landing zone. Clinical success in coverage of the lesions was achieved in all cases with the exception of an attempted treatment of an intraprocedural aortic valve implantation dissection that resulted in early mortality. The 30-day survival was 90%. Early neurologic events included one patient with stroke and paraplegia and one patient with a transient ischemic attack. One patient underwent early evacuation of a hemopericardium. There were two late reinterventions for persisting endoleaks. At a mean follow-up of 10 months (range, 1-36 months), three late deaths occurred, with one treatment related, as a result of graft infection. Despite the fact that in this first published series the graft was frequently used as a "rescue tool" outside its intended indication, treatment with the Zenith Ascend graft in this early experience appears to be safe and feasible for repair of ascending aorta pathologic processes in high-risk patients unsuitable for open repair. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

The effect of proximal anastomosis on the expansion rate of a dilated ascending aorta in coronary artery bypass surgery: a prospective study.

PubMed

Yavuz Balci, Ahmet; Vural, Unsal; Aksoy, Rezan; Özdemir, M Fatih; Satilmiş, Seçkin; Kizilay, Mehmet; Şenocak, Mutlu; Şaşkin, Huseyin; Kayacioğlu, Ilyas; Yekeler, Ibrahim

This study was designed to determine the short- and long-term effects of proximal aortic anastomosis, performed during isolated coronary artery bypass grafting (CABG) in patients with dilatation of the ascending aorta who did not require surgical intervention. The study was performed on 192 (38 female and 160 male patients; mean age, 62.1 ± 9.2 years; range, 42-80 years) patients with dilatation of the ascending aorta who underwent CABG surgery between 1 June 2006 and 31 May 2014. In group 1 (n = 114), the saphenous vein and left internal mammarian artery grafts were used, and proximal anastomosis was performed on the ascending aorta. In group 2 (n = 78), left and right internal mammarian artery grafts were used, and proximal aortic anastomosis was not performed. Pre-operatively and in the first and third years postoperatively, the ascending aortic diameter was measured and recorded using transthoracic echocardiography at four different regions (annulus, sinus of Valsalva, sinotubular junction and tubular aorta). A statistically significant difference was found between the groups for the number of grafts used and the duration of aortic cross-clamping and cardiopulmonary bypass. No significant intergroup difference was seen for the mean diameter of the ascending aorta (p > 0.05). Annual changes in the aortic diameter were found to be extremely significantly different in both groups (p = 0.0001). Mean values of the aortic diameter at the level of the sinotubular junction and tubular ascending aorta, mean aortic diameters (p = 0.002 and p = 0.0001, respectively), annual increase in diameter (p = 0.0001 and p = 0.0001, respectively), and mean annual difference in diameter (p = 0.0001 and p = 0.0001, respectively) at one and three years postoperatively were statistically significantly different between the groups. In patients with ascending aortic dilatation who did not require surgical intervention and who had proximal anastomosis of the ascending aorta and underwent only CABG, we detected statistically significant increases in the diameter of the sinotubular junction and tubular aorta up to three years postoperatively.

Gendered Patterns in International Research Collaborations in Academia

ERIC Educational Resources Information Center

Uhly, K. M.; Visser, L. M.; Zippel, K. S.

2017-01-01

Although women's representation in higher education nears parity with men at the undergraduate level, this representation diminishes as one ascends the academic ranks. Because gender gaps in the "elite" activity of international research collaborations might contribute to the underrepresentation of women in the upper ranks, we ask if…

Control of a simulated arm using a novel combination of Cerebellar learning mechanisms

NASA Technical Reports Server (NTRS)

Assad, C.; Hartmann, M.; Paulin, M. G.

2001-01-01

We present a model of cerebellar cortex that combines two types of learning: feedforward predicitve association based on local Hebbian-type learning between granule cell ascending branch and parallel fiber inputs, and reinforcement learning with feedback error correction based on climbing fiber activity.

Botulism in 2 urban dogs

PubMed Central

Uriarte, Ane; Thibaud, Jean-Laurent; Blot, Stéphane

2010-01-01

Two dogs from the same owner were referred for ascending weakness and paresis of 2 to 3 days duration. Electromyography and electroneurography determined that there were normal F-waves, decreased compound action potential, and decreased activity on repetitive nerve stimulation. These findings were valuable in diagnosing botulism in the dogs. PMID:21197207

Motivational Signage Increases Physical Activity on a College Campus

ERIC Educational Resources Information Center

Ford, M. Allison; Torok, Donald

2008-01-01

Objective: The authors evaluated whether motivational signage influenced rates of stair use relative to elevator use on a college campus. Participants: In March and April 2004, the authors observed students, faculty, staff, and any visitors accessing a college campus building. Methods: During Phase I, the authors monitored ascending stair and…

Assessment of nevirapine bioavailability from targeted sites in the human gastrointestinal tract.

PubMed

Macha, Sreeraj; Yong, Chan-Loi; MacGregor, Thomas R; Castles, Mark; Quinson, Anne-Marie; Rouyrre, Nicolas; Wilding, Ian

2009-12-01

This study investigated absorption of nevirapine (NVP) from targeted sites of the gastrointestinal tract using remotely activated capsules and gamma scintigraphy. A total of 24 participants were randomized to receive 50 mg NVP orally as a suspension or via remotely activated capsules for release into the ascending colon. The 24 participants were then rerandomized into parallel groups of n = 8 for drug release into the ileum, jejunum, or descending colon. The mean gastric emptying time of capsules ranged from 0.88 to 3.35 hours. The small intestinal and colon transit time ranged from 4.08 to 7.76 hours and 17.6 to 21.2 hours, respectively, and capsule recovery time ranged from 27.6 to 34.4 hours. The relative bioavailability ratio of NVP in the jejunum was 1.06 (90% confidence interval [CI]: 1.00-1.12) compared to suspension. In the ileum, ascending colon, and descending colon, bioavailability decreased to 0.89 (0.80-0.99), 0.82 (0.71-0.95), and 0.58 (0.22-1.53), respectively. The absorption rate decreased by approximately 10-fold from the jejunum (3.83 h(-1)) to the descending colon (0.338 h(-1)), and t(max) increased from 2.42 hours (jejunum) to 16.3 hours (descending colon). Overall, NVP is absorbed from all 4 sites of the gastrointestinal tract, and the rate of absorption decreased from the jejunum to the descending colon. Relative bioavailability of NVP was in the order of jejunum > ileum > ascending colon > descending colon.

Tibial rotation under combined in vivo loading after single- and double-bundle anterior cruciate ligament reconstruction.

PubMed

Tsarouhas, Alexander; Iosifidis, Michael; Spyropoulos, Giannis; Kotzamitelos, Dimitrios; Tsatalas, Themistoklis; Giakas, Giannis

2011-12-01

To evaluate in vivo the differences in tibial rotation between single- and double-bundle anterior cruciate ligament (ACL)-reconstructed knees under combined loading conditions. An 8-camera optoelectronic system and a force plate were used to collect kinematic and kinetic data from 14 patients with double-bundle ACL reconstruction, 14 patients with single-bundle reconstruction, 12 ACL-deficient subjects, and 12 healthy control individuals while performing 2 tasks. The first included walking, 60° pivoting, and stair ascending, and the second included stair descending, 60° pivoting, and walking. The 2 variables evaluated were the maximum range of internal-external tibial rotation and the maximum knee rotational moment. Tibial rotation angles were not significantly different across the 4 groups (P = .331 and P = .851, respectively) or when side-to-side differences were compared within groups (P = .216 and P = .371, respectively) for the ascending and descending maneuvers, nor were rotational moments among the 4 groups (P = .418 and P = .290, respectively). Similarly, for the descending maneuver, the rotational moments were not significantly different between sides (P = .192). However, for the ascending maneuver, rotational moments of the affected sides were significantly lower by 20.5% and 18.7% compared with their intact counterparts in the single-bundle (P = .015) and double-bundle (P = .05) groups, respectively. High-intensity activities combining stair ascending or descending with pivoting produce similar tibial rotation in single- and double-bundle ACL-reconstructed patients. During such maneuvers, the reconstructed knee may be subjected to significantly lower rotational loads compared with the intact knee. Level III, retrospective comparative study. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

What if the Diatoms of the Deep Chlorophyll Maximum Can Ascend?

NASA Astrophysics Data System (ADS)

Villareal, T. A.

2016-02-01

Buoyancy regulation is an integral part of diatom ecology via its role in sinking rates and is fundamental to understanding their distribution and abundance. Numerous studies have documented the effects of size and nutrition on sinking rates. Many pelagic diatoms have low intrinsic sinking rates when healthy and nutrient-replete (< 1-2 meters per day). Physiological control of buoyancy via ion regulation and osmolyte control can easily result in cell sap densities less than seawater, resulting in near-zero sinking rates across a large size spectrum of diatoms as well as positive buoyancy in giant diatoms with their low surface:volume ratio. Ascent by smaller diatoms is much less described although predicted in cells as small as 200 cubic microns. Decreased sedimentation rates have long been linked to formation of layers in the water column, particularly at the low light and nutricline conditions of the deep chlorophyll maximum. The potential for ascending behavior adds an additional layer of complexity by allowing both active depth regulation similar to that observed in flagellated taxa and upward transport by some fraction of deep euphotic zone diatom blooms supported by nutrient injection. In this talk, I review the data documenting positive buoyancy in small diatoms, offer direct visual evidence of ascending behavior in common diatoms typical of both oceanic and coastal zones, and note the characteristics of sinking rate distributions within a single species. Buoyancy control leads to bidirectional movement at similar rates across a wide size spectrum of diatoms although the frequency of ascending behavior may be only a small portion of the individual species' abundance. While much remains to be learned, the paradigm of unidirectional downward movement by diatoms is both inaccurate and an oversimplification.

Does it pay to have a damper in a powered ankle prosthesis? A power-energy perspective.

PubMed

Eslamy, Mahdy; Grimmer, Martin; Rinderknecht, Stephan; Seyfarth, Andre

2013-06-01

In this paper we investigated on peak power (PP) and energy (ER) requirements for different active ankle actuation concepts that can have both elasticity and damping characteristics. A lower PP or ER requirement is an important issue because it will lead to a smaller motor or battery. In addition to spring, these actuation concepts are assumed to have (passive) damper in series (series elastic-damper actuator SEDA) or parallel (parallel elastic-damper actuator PEDA) to the motor. For SEA (series elastic actuator), SEDA and PEDA, we calculated the required minimum motor PP and ER in different human gaits: normal level walking, ascending and descending the stairs. We found that for level walking and ascending the stairs, the SEA concept, and for descending, the SEDA, were the favorable concepts to reduce required minimum PP and ER in comparison to a DD (direct drive) concept. In SEDA concept, the minimum PP could be reduced to half of what SEA would require. Nevertheless, it was found that spring was always required, however damper showed 'task specific' advantages. As a result, if a simple design perspective is in mind, from PP-ER viewpoint, SEA could be the best compromise to be used for different above-mentioned gaits. For SEDA or PEDA concepts, a controllable damper should be used. In addition, our results show that it is beneficial to select spring stiffness in SEA, based on level walking gait. The PP and ER requirements would increase very slightly for stairs ascending, and to some extent (10.5%) for descending as a consequence of this selection. In contrast, stiffness selection based on stair ascending or descending, increases the PP requirements of level walking more noticeably (17-24%).

[Hypobaric chamber as a test of the aircrew of Russain Air Forces].

PubMed

Shishov, A A; Olenev, N I; Shishkin, A N; Filatov, V N

2014-04-01

Authors research clinical medical importance of hypobaric ascends to an attitude of 5000 meters for 20 minutes for detection of latent forms of diseases and assessment of professional health and ascends to an attitude of 5000 and 6000 meters for 5 minutes when performing psychophysiological training for high altitude flying. According to test of 1326 pilots of Russian Air Forces, including pilots with different diseases, hypobaric ascends showed high diagnostic effectiveness for the professional health assessment. By using of both methods it was revealed that frequency of detection of decreased tolerance to hypoxia is the same (in average in 2,7 and 3,1% of total number of patients). By ascends in 38 patients (2,9%) was revealed decreased tolerance to hypoxia of medium level. It indicated about low functional state and space capacity of pilots. It was proved that hypobaric ascends of 5000 and 6000 meters for 5 minutes could be considered as an effective method of checkup of aircrew for the aviation physical examination.

Ascending aortic injuries following blunt trauma.

PubMed

Sun, Xiumei; Hong, Jenny; Lowery, Robert; Goldstein, Steven; Wang, Zuyue; Lindsay, Joseph; Hill, Peter C; Corso, Paul J

2013-11-01

The diagnosis and the management of traumatic thoracic aortic injuries have undergone significant changes due to new technology and improved prehospital care. Most of the discussions have focused on descending aortic injuries. In this review, we discuss the recent management of ascending aortic injuries. We found 5 cohort studies on traumatic aortic injuries and 11 case reports describing ascending aortic injuries between 1998 to the present through Medline research. Among case reports, 78.9% of cases were caused by motor vehicle accidents (MVA). 42.1% of patients underwent emergent open repair and the operative mortality was 12.5%. 36.8% underwent delayed repair. Associated injuries occurred in 84.2% of patients. Aortic valve injury was concurrent in 26.3% of patients. The incidence of ascending aortic injury ranged 1.9-20% in cohort studies. Traumatic injuries to the ascending aorta are relatively uncommon among survivors following blunt trauma. Aortography has been replaced by computed tomography and echocardiography as a diagnostic tool. Open repair, either emergent or delayed, remains the treatment of choice. © 2013 Wiley Periodicals, Inc.

Francis Bacon: constructing natural histories of the invisible.

PubMed

Rusu, Doina-Cristina

2012-01-01

The natural histories contained in Francis Bacon's Historia naturalis et experimentalis seem to differ from the model presented in De augmentis scientiarum and the Descriptio globi intellectualis in that they are focused on the defining properties of matter, its primary schematisms and the spirits. In this respect, they are highly speculative. In this paper I aim to describe the Historia naturalis et experimentalis as a text about matter theory, the histories of which are ascending from what is most evident to the senses to what is least accessible to them. Moreover, the Latin natural histories are parts of a methodological procedure in which the provisional rules and axioms obtained in one history can be used as theoretical assumptions for another history, thereby permitting one to delve ever more profoundly into the structure of nature.

Left Ventricular Assist Device Implantation with Concomitant Aortic Valve and Ascending Aortic Replacement

PubMed Central

Panholzer, Bernd; Cremer, Jochen; Haneya, Assad

2018-01-01

Left ventricular assist device (LVAD) is nowadays a routine therapy for patients with advanced heart failure. We present the case of a 74-year-old male patient who was admitted to our center with terminal heart failure in dilated cardiomyopathy and ascending aortic aneurysm with aortic valve regurgitation. The LVAD implantation with simultaneous aortic valve and supracoronary ascending aortic replacement was successfully performed. PMID:29552039

Left Ventricular Assist Device Implantation with Concomitant Aortic Valve and Ascending Aortic Replacement.

PubMed

Huenges, Katharina; Panholzer, Bernd; Cremer, Jochen; Haneya, Assad

2018-01-01

Left ventricular assist device (LVAD) is nowadays a routine therapy for patients with advanced heart failure. We present the case of a 74-year-old male patient who was admitted to our center with terminal heart failure in dilated cardiomyopathy and ascending aortic aneurysm with aortic valve regurgitation. The LVAD implantation with simultaneous aortic valve and supracoronary ascending aortic replacement was successfully performed.

Carbon dioxide and ethanol release from champagne glasses, under standard tasting conditions.

PubMed

Liger-Belair, Gérard; Beaumont, Fabien; Bourget, Marielle; Pron, Hervé; Parvitte, Bertrand; Zéninari, Virginie; Polidori, Guillaume; Cilindre, Clara

2012-01-01

A simple glass of champagne or sparkling wine may seem like the acme of frivolity to most people, but in fact, it may rather be considered as a fantastic playground for any fluid physicist or physicochemist. In this chapter, results obtained concerning various steps where the CO₂ molecule plays a role (from its ingestion in the liquid phase during the fermentation process to its progressive release in the headspace above the tasting glass) are gathered and synthesized to propose a self-consistent and global overview of how gaseous and dissolved CO₂ impact champagne and sparkling wine science. Some recent investigations, conducted through laser tomography techniques, on ascending bubbles and ascending-bubble-driven flow patterns found in champagne glasses are reported, which illustrate the fine interplay between ascending bubbles and the fluid around under standard tasting conditions. The simultaneous monitoring of gaseous CO₂ and ethanol in the headspace of both a flute and a coupe filled with champagne was reported, depending on whether or not the glass shows effervescence. Both gaseous CO₂ and ethanol were found to be enhanced by the presence of ascending bubbles, thus confirming the close link between ascending bubbles, ascending-bubble-driven flow patterns, and the release of gaseous CO₂ and volatile organic compounds. Copyright © 2012 Elsevier Inc. All rights reserved.

Convergence of Cortical and Sensory Driver Inputs on Single Thalamocortical Cells

PubMed Central

Groh, Alexander; Bokor, Hajnalka; Mease, Rebecca A.; Plattner, Viktor M.; Hangya, Balázs; Stroh, Albrecht; Deschenes, Martin; Acsády, László

2014-01-01

Ascending and descending information is relayed through the thalamus via strong, “driver” pathways. According to our current knowledge, different driver pathways are organized in parallel streams and do not interact at the thalamic level. Using an electron microscopic approach combined with optogenetics and in vivo physiology, we examined whether driver inputs arising from different sources can interact at single thalamocortical cells in the rodent somatosensory thalamus (nucleus posterior, POm). Both the anatomical and the physiological data demonstrated that ascending driver inputs from the brainstem and descending driver inputs from cortical layer 5 pyramidal neurons converge and interact on single thalamocortical neurons in POm. Both individual pathways displayed driver properties, but they interacted synergistically in a time-dependent manner and when co-activated, supralinearly increased the output of thalamus. As a consequence, thalamocortical neurons reported the relative timing between sensory events and ongoing cortical activity. We conclude that thalamocortical neurons can receive 2 powerful inputs of different origin, rather than only a single one as previously suggested. This allows thalamocortical neurons to integrate raw sensory information with powerful cortical signals and transfer the integrated activity back to cortical networks. PMID:23825316

Aortic valve dysfunction and aortic dilation in adults with coarctation of the aorta.

PubMed

Clair, Mathieu; Fernandes, Susan M; Khairy, Paul; Graham, Dionne A; Krieger, Eric V; Opotowsky, Alexander R; Singh, Michael N; Colan, Steven D; Meijboom, Erik J; Landzberg, Michael J

2014-01-01

To determine the prevalence of aortic valve dysfunction, aortic dilation, and aortic valve and ascending aortic intervention in adults with coarctation of the aorta (CoA). Aortic valve dysfunction and aortic dilation are rare among children and adolescents with CoA. With longer follow-up, adults may be more likely to have progressive disease. We retrospectively reviewed all adults with CoA, repaired or unrepaired, seen at our center between 2004 and 2010. Two hundred sixteen adults (56.0% male) with CoA were identified. Median age at last evaluation was 28.3 (range 18.0 to 75.3) years. Bicuspid aortic valve (BAV) was present in 65.7%. At last follow-up, 3.2% had moderate or severe aortic stenosis, and 3.7% had moderate or severe aortic regurgitation. Dilation of the aortic root or ascending aorta was present in 28.0% and 41.6% of patients, respectively. Moderate or severe aortic root or ascending aortic dilation (z-score > 4) was present in 8.2% and 13.7%, respectively. Patients with BAV were more likely to have moderate or severe ascending aortic dilation compared with those without BAV (19.5% vs. 0%; P < 0.001). Age was associated with ascending aortic dilation (P = 0.04). At most recent follow-up, 5.6% had undergone aortic valve intervention, and 3.2% had aortic root or ascending aortic replacement. In adults with CoA, significant aortic valve dysfunction and interventions during early adulthood were uncommon. However, aortic dilation was prevalent, especially of the ascending aorta, in patients with BAV. © 2013 Wiley Periodicals, Inc.

Augmentation of the Ascending Component of the Peristaltic Reflex and Substance P Release by Glial Cell Line-Derived Neurotrophic Factor (GDNF)

PubMed Central

Grider, JR; Heuckeroth, RO; Kuemmerle, JF; Murthy, KS

2010-01-01

Glial cell line derived neurotrophic factor (GDNF) is present in adult gut although its role in the mature enteric nervous system is not well defined. The aim of the present study was to examine the role of GDNF as neuromodulator of the ascending phase of the peristaltic reflex. Colonic segments were prepared as flat sheets and placed in compartmented chambers so as to separate the sensory and motor limbs of the reflex. Ascending contraction was measured in the orad compartment and mucosal stroking stimuli (2-8 strokes) were applied in the caudad compartment. GDNF and substance P release were measured and the effects of GDNF and GDNF antibody on contraction and release were determined. Mice with reduced levels of GDNF (Gdnf+/-) and wild type littermates were also examined. GDNF was released in a stimulus-dependent manner into the orad motor but not caudad sensory compartment. Addition of GDNF to the orad motor but not caudad sensory compartment augmented ascending contraction and substance P release. Conversely, addition of GDNF antibody to the orad motor but not caudad sensory compartment reduced ascending contraction and substance P release. Similarly, the ascending contraction and substance P release into the orad motor compartment was reduced in Gdnf+/- mice as compared to wild type littermates. The results suggest that endogenous GDNF is released during the ascending contraction component of the peristaltic reflex where it acts as a neuromodulator to augment substance P release from motor neurons thereby augmenting contraction of circular muscle orad to the site of stimulation. PMID:20331804

Augmentation of the ascending component of the peristaltic reflex and substance P release by glial cell line-derived neurotrophic factor.

PubMed

Grider, J R; Heuckeroth, R O; Kuemmerle, J F; Murthy, K S

2010-07-01

Glial cell line-derived neurotrophic factor (GDNF) is present in adult gut although its role in the mature enteric nervous system is not well defined. The aim of the present study was to examine the role of GDNF as neuromodulator of the ascending phase of the peristaltic reflex. Colonic segments were prepared as flat sheets and placed in compartmented chambers so as to separate the sensory and motor limbs of the reflex. Ascending contraction was measured in the orad compartment and mucosal stroking stimuli (two to eight strokes) were applied in the caudad compartment. GDNF and substance P (SP) release were measured and the effects of GDNF and GDNF antibody on contraction and release were determined. Mice with reduced levels of GDNF (Gdnf(+/-)) and wild type littermates were also examined. GDNF was released in a stimulus-dependent manner into the orad motor but not caudad sensory compartment. Addition of GDNF to the orad motor but not caudad sensory compartment augmented ascending contraction and SP release. Conversely, addition of GDNF antibody to the orad motor but not caudad sensory compartment reduced ascending contraction and SP release. Similarly, the ascending contraction and SP release into the orad motor compartment was reduced in Gdnf(+/-) mice as compared to wild type littermates. The results suggest that endogenous GDNF is released during the ascending contraction component of the peristaltic reflex where it acts as a neuromodulator to augment SP release from motor neurons thereby augmenting contraction of circular muscle orad to the site of stimulation.

Longitudinal and Circumferential Strain of the Proximal Aorta

PubMed Central

Bell, Vanessa; Mitchell, William A.; Sigurðsson, Sigurður; Westenberg, Jos J. M.; Gotal, John D.; Torjesen, Alyssa A.; Aspelund, Thor; Launer, Lenore J.; de Roos, Albert; Gudnason, Vilmundur; Harris, Tamara B.; Mitchell, Gary F.

2014-01-01

Background Accurate assessment of mechanical properties of the proximal aorta is a requisite first step for elucidating the pathophysiology of isolated systolic hypertension. During systole, substantial proximal aortic axial displacement produces longitudinal strain, which we hypothesize causes variable underestimation of ascending aortic circumferential strain compared to values in the longitudinally constrained descending aorta. Methods and Results To assess effects of longitudinal strain, we performed magnetic resonance imaging in 375 participants (72 to 94 years old, 204 women) in the Age, Gene/Environment Susceptibility‐Reykjavik Study and measured aortic circumferential and longitudinal strain. Circumferential ascending aortic area strain uncorrected for longitudinal strain was comparable in women and men (mean [95% CI], 8.3 [7.8, 8.9] versus 7.9 [7.4, 8.5]%, respectively, P=0.3). However, longitudinal strain was greater in women (8.5±2.5 versus 7.0±2.5%, P<0.001), resulting in greater longitudinally corrected circumferential ascending aortic strain (14.4 [13.6, 15.2] versus 13.0 [12.4, 13.7]%, P=0.010). Observed circumferential descending aortic strain, which did not require correction (women: 14.0 [13.2, 14.8], men: 12.4 [11.6, 13.2]%, P=0.005), was larger than uncorrected (P<0.001), but comparable to longitudinally corrected (P=0.12) circumferential ascending aortic strain. Carotid‐femoral pulse wave velocity did not correlate with uncorrected ascending aortic strain (R=−0.04, P=0.5), but was inversely related to longitudinally corrected ascending and observed descending aortic strain (R=−0.15, P=0.004; R=−0.36, P<0.001, respectively). Longitudinal strain was also inversely related to carotid‐femoral pulse wave velocity and other risk factors for higher aortic stiffness including treated hypertension. Conclusions Longitudinal strain creates substantial and variable errors in circumferential ascending aortic area strain measurements, particularly in women, and should be considered to avoid misclassification of ascending aortic stiffness. PMID:25523153

Loss of pulse pressure amplification between the ascending and descending aorta in patients after an aortic arch repair.

PubMed

Murakami, Tomoaki; Shiraishi, Masahiro; Nawa, Tomohiro; Takeda, Atsuhito

2017-03-01

One of the most important problems in patients with an aortic coarctation after an aortic arch repair is future cardiovascular disease. We previously reported the enhancement of the aortic pressure wave reflection in patients and hypothesized that the enhancement was caused by a new pressure wave reflection generated from the repaired site. To prove the hypothesis, we analyzed the pressure waveform in the ascending and descending aorta and examined their pulse pressure (PP) amplification. Fifteen patients after an aortic arch repair without a recoarctation were enrolled. The ascending and descending aorta pressure waveforms were recorded by a pressure sensor mounted catheter. The pressures were compared with those of age-matched controls. The patient's age was 7.3 ± 2.7 years, and they underwent the aortic arch repair at 30.1 ± 29.0 days. The ascending aorta SBP (106.1 ± 12.7 mmHg) was higher than in the control patients (97.9 ± 14.3) (P = 0.015). The PP at the ascending aorta in the patients (41.3 ± 7.8) was wider than that in the controls (36.4 ± 5.0) (P = 0.010). There was no difference concerning the PP at the descending aorta between the patients (41.0 ± 7.7) and controls (40.5 ± 6.5). The difference in the PP between the descending and ascending aorta (PP at the descending aorta - PP at the ascending aorta) in the patients was -0.3 ± 1.7 and 5.1 ± 2.9 in the controls (P < 0.0001). The ascending aortic PP was augmented in the patients after the aortic arch repair. It could be one of the causes of future cardiovascular disease.

Diagnostic performance of focused cardiac ultrasound performed by emergency physicians for the assessment of ascending aorta dilation and aneurysm.

PubMed

Nazerian, Peiman; Vanni, Simone; Morello, Fulvio; Castelli, Matteo; Ottaviani, Maddalena; Casula, Claudia; Petrioli, Alessandra; Bartolucci, Maurizio; Grifoni, Stefano

2015-05-01

The diagnostic performance of transthoracic focused cardiac ultrasound (FoCUS) performed by emergency physicians (EP) to estimate ascending aorta dimensions in the acute setting has not been prospectively studied. The diagnostic accuracy and the interobserver variability of EP-performed FoCUS were investigated to estimate thoracic aortic dilation and aneurysm compared with the results of computed tomography angiography (CTA). This was a prospective single-center cohort study of a convenience sample of patients who underwent CTA in the emergency department for suspected aortic pathology. FoCUS was performed before CTA, and the maximum ascending aorta diameter evaluated in parasternal long-axis view. Aorta diameter < 40 mm by visual estimation or by diameter measurement was considered normal. Measurements were recorded in all patients with aorta diameter ≥ 40 mm. Diagnostic accuracy of FoCUS for detection of aortic dilation (diameter ≥ 40 mm) and aneurysm (diameter ≥ 45 mm) were calculated considering the CTA result as reference standard. In a subgroup of patients, a second EP-sonographer performed FoCUS to evaluate interobserver agreement for the diagnosis of ascending aorta dilation. A total of 140 patients were enrolled in the study. Ascending aorta dilation and aneurysm were detected with FoCUS in 50 (35.7%) and in 27 (17.8%) patients, respectively. Sensitivity and specificity of FoCUS were 78.6% (95% confidence interval [CI] = 65.6% to 88.4%) and 92.9% (95% CI = 85.1% to 97.3%), respectively, for ascending aorta dilation and 64.7% (95% CI = 46.5% to 80.2%) and 95.3% (95% CI = 89.3% to 98.4%), respectively, for ascending aorta aneurysm. Interobserver agreement of FoCUS was k = 0.82. FoCUS performed by EP is specific for ascending aorta dilation and aneurysm when compared to CTA and appears a reproducible technique. © 2015 by the Society for Academic Emergency Medicine.

Seismic evidence for a possible deep crustal hot zone beneath Southwest Washington.

PubMed

Flinders, Ashton F; Shen, Yang

2017-08-07

Crustal pathways connecting deep sources of melt and the active volcanoes they supply are poorly understood. Beneath Mounts St. Helens, Adams, and Rainier these pathways connect subduction-induced ascending melts to shallow magma reservoirs. Petrogenetic modeling predicts that when these melts are emplaced as a succession of sills into the lower crust they generate deep crustal hot zones. While these zones are increasingly recognized as a primary site for silicic differentiation at a range of volcanic settings globally, imaging them remains challenging. Near Mount Rainier, ascending melt has previously been imaged ~28 km northwest of the volcano, while to the south, the volcano lies on the margin of a broad conductive region in the deep crust. Using 3D full-waveform tomography, we reveal an expansive low-velocity zone, which we interpret as a possible hot zone, linking ascending melts and shallow reservoirs. This hot zone may supply evolved magmas to Mounts St. Helens and Adams, and possibly Rainier, and could contain approximately twice the melt volume as the total eruptive products of all three volcanoes combined. Hot zones like this may be the primary reservoirs for arc volcanism, influencing compositional variations and spatial-segmentation along the entire 1100 km-long Cascades Arc.

Seismic evidence for a possible deep crustal hot zone beneath Southwest Washington

USGS Publications Warehouse

Flinders, Ashton; Shen, Yang

2017-01-01

Crustal pathways connecting deep sources of melt and the active volcanoes they supply are poorly understood. Beneath Mounts St. Helens, Adams, and Rainier these pathways connect subduction-induced ascending melts to shallow magma reservoirs. Petrogenetic modeling predicts that when these melts are emplaced as a succession of sills into the lower crust they generate deep crustal hot zones. While these zones are increasingly recognized as a primary site for silicic differentiation at a range of volcanic settings globally, imaging them remains challenging. Near Mount Rainier, ascending melt has previously been imaged ~28 km northwest of the volcano, while to the south, the volcano lies on the margin of a broad conductive region in the deep crust. Using 3D full-waveform tomography, we reveal an expansive low-velocity zone, which we interpret as a possible hot zone, linking ascending melts and shallow reservoirs. This hot zone may supply evolved magmas to Mounts St. Helens and Adams, and possibly Rainier, and could contain approximately twice the melt volume as the total eruptive products of all three volcanoes combined. Hot zones like this may be the primary reservoirs for arc volcanism, influencing compositional variations and spatial-segmentation along the entire 1100 km-long Cascades Arc.

The Association of Clinic-Based Mobility Tasks and Measures of Community Performance and Risk.

PubMed

Callisaya, Michele L; Verghese, Joe

2018-01-10

Gait speed is recognized as an important predictor of adverse outcomes in older people. However, it is unknown whether other more complex mobility tasks are better predictors of such outcomes. To examine a range of clinic-based mobility tests and determine which were most strongly associated with measures of community performance and risk (CP&R). Cross-sectional study. Central Control Mobility and Aging Study, Westchester County, New York. Aged ≥65 years (n = 424). Clinic-based mobility measures included gait speed measured during normal and dual-task conditions, the Floor Maze Immediate and Delay tasks, and stair ascending and descending. CP&R measures were self-reported by the use of standardized questionnaires and classified into measures of performance (distance walked, travel outside one's home [life space], activities of daily living, and participation in cognitive leisure activities) or risk (balance confidence, fear of falling, and past falls). Linear and logistic regression were used to examine associations between the clinic-based mobility measures and CP&R measures adjusting for covariates. The mean age of the sample was 77.8 (SD 6.4) years, and 55.2% (n = 234) were female. In final models, faster normal walking speed was most strongly associated with 5 of the 7 community measures (greater distance walked, greater life space, better activities of daily living function, higher balance confidence, and less fear of falling; all P < .05). More complex tasks (walking while talking and maze immediate) were associated with cognitive leisure activity (P < .05), and ascending stairs was the only measure associated with a history of falls (P < .05). Normal walking speed is a simple and inexpensive clinic-based mobility test that is associated with a wide range of CP&R measures. In addition, poorer performance ascending stairs may assist in identifying those at risk of falls. Poorer performance in more complex mobility tasks (walking while talking and maze immediate) may suggest inability to participate in cognitive leisure activities. III. Copyright © 2018 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Interrater and intrarater reliability of the Semmes Weinstein aesthesiometer to assess touch pressure threshold in burn scars.

PubMed

Meirte, J; Moortgat, P; Truijen, S; Maertens, K; Lafaire, C; De Cuyper, L; Hubens, G; Van Daele, U

2015-09-01

Burn scars are frequently accompanied with sensory deficits often remaining present months or even years after injury. Clinimetric properties of assessment tools remain understudied within burn literature. Tactile sense of touch can be examined with the touch pressure threshold (TPT) method using the Semmes Weinstein monofilament test (SWMT). There is in recent research no consensus on the exact measurement procedure when using the SWMT. The aim of this paper was to determine the interrater and intrarater reliability of TPT within burn scars and healthy controls using the 'ascending descending' measurement procedure. We used the newly developed guidelines for reporting reliability and agreement studies (GRRAS) as a basis to report this reliability study. In total 36 individuals were tested; a healthy control group and a scar group. The interrater reliability was excellent in the scar group (ICC=0.908/SEM=0.21) and fair to good in the control group (ICC=0.731/SEM=0.12). In the scar group intrarater ICC value was excellent (ICC=0.822/SEM=0.33). Within the control group also an excellent intrarater reliability (ICC=0.807/SEM=0.27) was found. In conclusion this study shows that the SWMT with the 'ascending descending' measurement procedure is a feasible and reliable objective measure to evaluate TPT in (older) upper extremities burn scars as well as in healthy skin. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Concentrations and loads of cadmium, lead, and zinc measured on the ascending and descending limbs of the 1999 snowmelt-runoff hydrographs for nine water-quality stations, Coeur d'Alene River basin, Idaho

USGS Publications Warehouse

Woods, Paul F.

2001-01-01

Hysteresis effects on concentrations and loads over the ascending and descending limbs of the snowmelt-runoff hydrograph were quite apparent, especially for whole-water recoverable constituents. Hysteresis is present when a property, such as constituent concentration or load, has different values for a given discharge over the ascending and descending limbs of a hydrograph. During this study, loads of whole-water recoverable constituents on the ascending limb were between 1.5 and 3.6 times larger than those mea- sured on the descending limb at nearly equal discharge. In contrast, dissolved constituents showed minimal hysteresis effects.

Investigation of Land Subsidence using ALOS PALSAR data: a case study in Mentougou (Beijing, China)

NASA Astrophysics Data System (ADS)

Chen, Jianping; Xiang, Jie; Xie, Shuai; Liu, Jing; Tarolli, Paolo

2017-04-01

Mining activities have been documented for centuries in Mentougou, and land subsidence resulting from mining operations has already been known over the past few decades. However, there has been ongoing concern that excessive groundwater extraction may lead to further subsidence. Therefore it is critical to map the land cover changes to understand the actual impact of these activities. So, the land cover changes from 2006 to 2011 were examined based on multi-source remote sensing imageries( including ALOS and landsat-7) by using object-oriented classifications combined with a decision tree and retrospective approaches. Also, land subsidence in Mentougou between 2006 and 2011 has been mapped using the interferometric synthetic aperture radar (InSAR) time-series analysis with the ALOS L-band SAR data. We processed 14 ascending SAR images during May 2006 to July 2011. Comparison of InSAR measurements with the land cover changes and pre-existing faults suggest that mining activities is the main cause of land subsidence. The land subsidence observed from InSAR data are approximately up to 15 mm/year in open-pit mining area and up to 24 mm/year in underground mining areas. The InSAR result are validated by the ground survey data in several areas, and the comparison between the InSAR result with the mining schedule showed there were some correlations between them. The result underline the potential use of InSAR measurements to provide better investigation for land subsidence, and also suggest that the most influential factors for land subsidence is underground coal mine.

Behavioral Specifications of Reward-Associated Long-Term Memory Enhancement in Humans

ERIC Educational Resources Information Center

Wittmann, Bianca C.; Dolan, Raymond J.; Duzel, Emrah

2011-01-01

Recent functional imaging studies link reward-related activation of the midbrain substantia nigra-ventral tegmental area (SN/VTA), the site of origin of ascending dopaminergic projections, with improved long-term episodic memory. Here, we investigated in two behavioral experiments how (1) the contingency between item properties and reward, (2) the…

Natural history of moderately dilated tubular ascending aorta: implications for determining the optimal imaging interval.

PubMed

Park, Kay-Hyun; Chung, Suryeun; Kim, Dong Jung; Kim, Jun Sung; Lim, Cheong

2017-05-01

For a moderately dilated ascending aorta (diameter 35-54 mm), current guidelines recommend continuous annual or semi-annual examinations with computed tomography or magnetic resonance imaging. However, few data have shown the yield and benefit of such a protocol. This study aimed to investigate the fate of a moderately dilated ascending aorta and thereby determine the adequate imaging interval. In our institutional database, we identified adult patients having an ascending aortic diameter ≥40 mm in contrast-enhanced computed tomography and follow-up imaging(s) after ≥1 year. Of the 509 patients (mean age 67.2 ± 10.4 years) enrolled in the study, the maximal diameter of the ascending aorta was compared between the first and last images. Also, their medical records were reviewed to investigate the associated illness and clinical events. The mean growth rate of the patients with a 40-44 mm ( n  = 321), 45-49 mm ( n  = 142) and ≥50 mm ( n  = 46) ascending aorta was 0.3 ± 0.5, 0.3 ± 0.5 and 0.7 ± 0.9 mm/year, respectively. During the mean interval of 4.3 ± 2.4 years, significant progression (diameter increase by ≥5 mm) occurred in 3.4, 5.6 and 21.7%, respectively. The 3- to 5-year rates of freedom from significant progression were 99.1%-96.5% (40-44 mm) and 97.8%-96.4% (45-49 mm). In multivariate analysis, initial ascending aortic diameter ≥45 mm and aortic valve regurgitation were significantly associated with significant progression. Acute type A aortic dissection occurred in 5 patients (1%), before the maximal diameter of the ascending aorta reached 55 mm or significant progression was observed. For a moderately dilated ascending aorta not exceeding 45 mm in maximal diameter and stable in the first annual follow-up image, a 3- to 4-year interval would be reasonable before subsequent imaging. More frequent imaging may be warranted in patients with aortic valve insufficiency or with an aortic diameter ≥45 mm. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Restoration of the ascending reticular activating system compressed by hematoma in a stroke patient

PubMed Central

Jang, Sung Ho; Seo, Jeong Pyo

2017-01-01

Abstract Rationale: We report on restoration of the ascending reticular activating system (ARAS), compressed by an intracerebral hematoma and perihematomal edema following a stroke. The restoration of the ARAS was demonstrated by diffusion tensor tractography (DTT). Patient concerns: In a 60-year-old male, a brain MRI taken at 2 weeks after the surgery showed a hematoma and perihematomal edema in the left posterolateral pons and cerebellum, which were markedly resolved on a brain MRI after 5 weeks. Diagnoses: Intraventricular hemorrhage. Interventions: Navigation-guided stereotactic drainage of a hematoma in the left cerebellum, comprehensive rehabilitative therapy, including hypersomnia medication (modafinil), physical therapy, and occupational therapy. Outcomes: His hypersomnia improved significantly with rehabilitation, with no daytime hypersomnia beginning 3 weeks after the surgery. On 2-week DTT, neither the neural tract of the left lower dorsal or ventral ARAS were reconstructed, but these neural tracts were wellreconstructed on 5-week DTT. Lessons: In conclusion, restoration of nonreconstructed neural tracts of the lower ARAS with the resolution of the hematoma and perihematomal edema was demonstrated in a stroke patient, using DTT. PMID:28207526

Hypersomnia due to injury of the ventral ascending reticular activating system following cerebellar herniation: A case report.

PubMed

Jang, Sung Ho; Chang, Chul Hoon; Jung, Young Jin; Kwon, Hyeok Gyu

2017-01-01

We report on a patient with hypersomnia who showed injury of the lower ascending reticular activating system (ARAS) following cerebellar herniation due to a cerebellar infarct, detected on diffusion tensor tractography (DTT). A 53-year-old male patient was diagnosed as a left cerebellar infarct, and underwent decompressive suboccipital craniectomy due to brain edema at 2 days after the onset of a cerebellar infarct. Three weeks after onset when the patient started rehabilitation, he showed hypersomnia without impairment of consciousness; he fell asleep most of daytime without external stimulation and showed an abnormal score on the Epworth Sleepiness Scale: 15 (full score: 24, cut off for hypersomnia: 10). On 3-week DTT, narrowing of the upper portion of the lower ventral ARAS between the pontine reticular formation and the hypothalamus was observed on both sides. In addition, partial tearing was observed in the middle portion of the right lower ventral ARAS. In conclusion, we found injury of the lower ventral ARAS in a patient with hypersomnia following cerebellar herniation due to a cerebellar infarct.

Machine-learning phenotypic classification of bicuspid aortopathy.

PubMed

Wojnarski, Charles M; Roselli, Eric E; Idrees, Jay J; Zhu, Yuanjia; Carnes, Theresa A; Lowry, Ashley M; Collier, Patrick H; Griffin, Brian; Ehrlinger, John; Blackstone, Eugene H; Svensson, Lars G; Lytle, Bruce W

2018-02-01

Bicuspid aortic valves (BAV) are associated with incompletely characterized aortopathy. Our objectives were to identify distinct patterns of aortopathy using machine-learning methods and characterize their association with valve morphology and patient characteristics. We analyzed preoperative 3-dimensional computed tomography reconstructions for 656 patients with BAV undergoing ascending aorta surgery between January 2002 and January 2014. Unsupervised partitioning around medoids was used to cluster aortic dimensions. Group differences were identified using polytomous random forest analysis. Three distinct aneurysm phenotypes were identified: root (n = 83; 13%), with predominant dilatation at sinuses of Valsalva; ascending (n = 364; 55%), with supracoronary enlargement rarely extending past the brachiocephalic artery; and arch (n = 209; 32%), with aortic arch dilatation. The arch phenotype had the greatest association with right-noncoronary cusp fusion: 29%, versus 13% for ascending and 15% for root phenotypes (P < .0001). Severe valve regurgitation was most prevalent in root phenotype (57%), followed by ascending (34%) and arch phenotypes (25%; P < .0001). Aortic stenosis was most prevalent in arch phenotype (62%), followed by ascending (50%) and root phenotypes (28%; P < .0001). Patient age increased as the extent of aneurysm became more distal (root, 49 years; ascending, 53 years; arch, 57 years; P < .0001), and root phenotype was associated with greater male predominance compared with ascending and arch phenotypes (94%, 76%, and 70%, respectively; P < .0001). Phenotypes were visually recognizable with 94% accuracy. Three distinct phenotypes of bicuspid valve-associated aortopathy were identified using machine-learning methodology. Patient characteristics and valvular dysfunction vary by phenotype, suggesting that the location of aortic pathology may be related to the underlying pathophysiology of this disease. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Ascending-ramp biphasic waveform has a lower defibrillation threshold and releases less troponin I than a truncated exponential biphasic waveform.

PubMed

Huang, Jian; Walcott, Gregory P; Ruse, Richard B; Bohanan, Scott J; Killingsworth, Cheryl R; Ideker, Raymond E

2012-09-11

We tested the hypothesis that the shape of the shock waveform affects not only the defibrillation threshold but also the amount of cardiac damage. Defibrillation thresholds were determined for 11 waveforms-3 ascending-ramp waveforms, 3 descending-ramp waveforms, 3 rectilinear first-phase biphasic waveforms, a Gurvich waveform, and a truncated exponential biphasic waveform-in 6 pigs with electrodes in the right ventricular apex and superior vena cava. The ascending, descending, and rectilinear waveforms had 4-, 8-, and 16-millisecond first phases and a 3.5-millisecond rectilinear second phase that was half the voltage of the first phase. The exponential biphasic waveform had a 60% first-phase and a 50% second-phase tilt. In a second study, we attempted to defibrillate after 10 seconds of ventricular fibrillation with a single ≈30-J shock (6 pigs successfully defibrillated with 8-millisecond ascending, 8-millisecond rectilinear, and truncated exponential biphasic waveforms). Troponin I blood levels were determined before and 2 to 10 hours after the shock. The lowest-energy defibrillation threshold was for the 8-milliseconds ascending ramp (14.6±7.3 J [mean±SD]), which was significantly less than for the truncated exponential (19.6±6.3 J). Six hours after shock, troponin I was significantly less for the ascending-ramp waveform (0.80±0.54 ng/mL) than for the truncated exponential (1.92±0.47 ng/mL) or the rectilinear waveform (1.17±0.45 ng/mL). The ascending ramp has a significantly lower defibrillation threshold and at ≈30 J causes 58% less troponin I release than the truncated exponential biphasic shock. Therefore, the shock waveform affects both the defibrillation threshold and the amount of cardiac damage.

Cerebral and Renal Oxygen Saturation Are Not Compromised in the Presence of Retrograde Blood Flow in either the Ascending or Descending Aorta in Term or Near-Term Infants with Left-Sided Obstructive Lesions.

PubMed

van der Laan, Michelle E; Mebius, Mirthe J; Roofthooft, Marcus T R; Bos, Arend F; Berger, Rolf M F; Kooi, Elisabeth M W

2017-01-01

In infants with left-sided obstructive lesions (LSOL), the presence of retrograde blood flow in either the ascending or descending aorta may lead to diminished cerebral and renal blood flow, respectively. Our aim was to compare cerebral and renal tissue oxygen saturation (rSO2) between infants with LSOL with antegrade and retrograde blood flow in the ascending aorta and with and without diastolic backflow in the descending aorta. Based on 2 echocardiograms, the study group was categorized according to the direction of blood flow in the ascending and descending aorta. We measured cerebral and renal rSO2 using near-infrared spectroscopy and calculated fractional tissue oxygen extraction (FTOE). Nineteen infants with LSOL, admitted to the NICU between 0 and 28 days after birth, were included. Infants with antegrade blood flow (n = 12) and infants with retrograde blood flow in the ascending aorta (n = 7) had similar cerebral rSO2 and FTOE during both echocardiograms. Only during the first echocardiogram, infants with retrograde blood flow in the ascending aorta had lower renal FTOE (0.14 vs. 0.32, p = 0.04) and tended to have higher renal rSO2 (80 vs. 65%, p = 0.09). The presence of diastolic backflow in the descending aorta was not associated with cerebral or renal rSO2 and FTOE during the first (n = 8) as well as the second echocardiogram (n = 10). Retrograde blood flow in the ascending aorta was not associated with cerebral oxygenation, while diastolic backflow in the descending aorta was not associated with renal oxygenation in infants with LSOL. © 2017 S. Karger AG, Basel.

Hemiarch Reconstruction Vs Clamped Aortic Anastomosis for Concomitant Ascending Aortic Aneurysm.

PubMed

Sultan, Ibrahim; Bianco, Valentino; Yajzi, Ibrahim; Kilic, Arman; Dufendach, Keith; Cardounel, Arturo; Althouse, Andrew D; Masri, Ahmad; Navid, Forozan; Gleason, Thomas G

2018-05-03

Deep hypothermic circulatory arrest (DHCA) is often avoided in patients with concomitant ascending aortic pathology when treating other cardiac disease to avoid increased risk of morbidity and mortality. We hypothesized that the use of DHCA with retrograde cerebral perfusion (RCP) does not add incremental risk to ascending aortic replacement alone in the setting of concomitant cardiac surgery. 408 ascending aortic ± hemiarch replacements and aortic (root)/mitral/tricuspid valve(s), CABG, or MAZE procedures were performed for concomitant cardiac disease. DHCA with RCP was used for all hemiarch replacements or the ascending aorta was replaced with an aortic cross-clamp proximal to the innominate artery. Propensity-score matching was used to match similar ascending patients vs. hemiarch patients; the final propensity score matched patients on age, gender, BMI, previous heart surgery, pre-op aortic insufficiency, pre-op aortic stenosis, pre-op EF, and operative variables. Propensity-score matching yielded 116 pairs of Non-hemiarch patients vs. 116 hemiarch patients. Within the propensity-score matched cohort, there were no differences in postoperative stroke (1.7% vs. 3.4%, p = 0.41), new postoperative dialysis (6.0% vs. 5.2%, p = 0.78), postoperative renal insufficiency (27.6% vs. 19.8%, p = 0.16), 30-day mortality (2.6% vs. 3.4%, p = 0.701), or 1-year mortality (4.3% vs. 4.3%, p = 1.00) CONCLUSIONS: Hemiarch replacement using DHCA with RCP does not increase the risk of operative complications compared to a normothermic, clamped-distal aortic anastomosis, and therefore its use should not be limited when planning complex multi-procedural reconstructions during elective ascending thoracic aortic replacement with concomitant cardiac surgery. Copyright © 2018. Published by Elsevier Inc.

Structure-activity relationships of tetramethylpiperidine-substituted phenazines against Mycobacterium leprae in vitro.

PubMed Central

Franzblau, S G; White, K E; O'Sullivan, J F

1989-01-01

In a previous study of structure-activity relationships of selected phenazines against Mycobacterium leprae in vitro, compounds containing a 2,2,6,6-tetramethylpiperidine substitution at the imino nitrogen were most active. Therefore, the effect of substitution at the para positions of the phenyl and anilino groups in tetramethylpiperidine-substituted phenazines was assessed. As determined by radiorespirometry, activity in ascending order was observed in compounds substituted with hydrogens or fluorines, ethoxy groups, methyl groups, chlorines, and bromines and correlated with partition coefficients in octanol-water. PMID:2692516

SPARKy - Spring Ankle with Regenerative Kinetics to Build a New Generation of Transtibial Prostheses

DTIC Science & Technology

2010-07-01

walking on inclines/declines, and ascending/descending stairs We are able to walk continuously over ground and can walk up and down slopes and... stairs . Walking up a slope and ascending stairs needs to be improved, adding extra propulsion. The propulsion walking down stairs needs to be...bodied subjects walking on flat even surfaces, inclines/declines, and ascending/descending stairs – In Process 4. Using able bodied test data, a

Ascending aorta dilatation in patients with bicuspid aortic valve stenosis: a prospective CMR study.

PubMed

Rossi, Alexia; van der Linde, Denise; Yap, Sing Chien; Lapinskas, Thomas; Kirschbaum, Sharon; Springeling, Tirza; Witsenburg, Maarten; Cuypers, Judith; Moelker, Adriaan; Krestin, Gabriel P; van Dijk, Arie; Johnson, Mark; van Geuns, Robert-Jan; Roos-Hesselink, Jolien W

2013-03-01

The aim of this study was to evaluate the natural progression of aortic dilatation and its association with aortic valve stenosis (AoS) in patients with bicuspid aortic valve (BAV). Prospective study of aorta dilatation in patients with BAV and AoS using cardiac magnetic resonance (CMR). Aortic root, ascending aorta, aortic peak velocity, left ventricular systolic and diastolic function and mass were assessed at baseline and at 3-year follow-up. Of the 33 enrolled patients, 5 needed surgery, while 28 patients (17 male; mean age: 31 ± 8 years) completed the study. Aortic diameters significantly increased at the aortic annulus, sinus of Valsalva and tubular ascending aorta levels (P < 0.050). The number of patients with dilated tubular ascending aortas increased from 32 % to 43 %. No significant increase in sino-tubular junction diameter was observed. Aortic peak velocity, ejection fraction and myocardial mass significantly increased while the early/late filling ratio significantly decreased at follow-up (P < 0.050). The progression rate of the ascending aorta diameter correlated weakly with the aortic peak velocity at baseline (R (2) = 0.16, P = 0.040). BAV patients with AoS showed a progressive increase of aortic diameters with maximal expression at the level of the tubular ascending aorta. The progression of aortic dilatation correlated weakly with the severity of AoS.

Correlation of ascending aorta elasticity and the severity of coronary artery stenosis in hypertensive patients with coronary heart disease assessed by M-mode and tissue Doppler echocardiography.

PubMed

Lu, Qixiu; Liu, Houlin

2015-03-01

The main objective of this study is to investigate the relationship between ascending aorta elasticity and the severity of coronary artery stenosis in essential hypertensive patients with coronary heart disease (CHD) using M-mode and tissue Doppler echocardiography. A total of 184 hypertensive patients with CHD were enrolled. Patients were divided into three groups based on the severity of coronary stenosis measured by coronary arteriography (CAG): slight stenosis (group 1), moderate stenosis (group 2) and serious stenosis (group 3). M-mode and tissue Doppler echocardiography were performed, and elasticity indexes of ascending aorta including stiffness index, distensibility index, and S wave speed of anterior wall were calculated and correlated with the severity of coronary stenosis. Ascending aorta stiffness index was increased, whereas distensibility index and S wave speed of anterior wall were decreased in moderate and severe stenosis groups compared with slight stenosis group (P < 0.01). Elasticity indexes change in a stepwise pattern with the narrowness of coronary artery, and there was a significant correlation between aortic elasticity and severity of coronary artery by Pearson correlation analysis (P < 0.01). Elasticity indexes of ascending aorta correlate well with severity of coronary stenosis. Elasticity indexes of ascending aorta can serve as predictors for coronary arterial lesion in hypertensive patients.

Implementation of a Fiber Raman Amplifier for CW-IM Measurements of Atmospheric Oxygen at 1.26 Microns

NASA Astrophysics Data System (ADS)

Dobler, J. T.; Nagel, J.; Temyanko, V.; Zaccheo, S.; Browell, E. V.; Kooi, S. A.

2011-12-01

Starting in February 2009 ITT, along with our partners at TIPD, AER and NASA LaRC, has been working to develop a fiber Raman amplifier at a wavelength near 1.26 microns, and evaluate its performance for measuring atmospheric O2 remotely. Two prototype amplifiers have been built and integrated into an existing continuous wave (CW) intensity modulated (IM) engineering development unit (EDU), developed at ITT for the measurement of CO2, in order to demonstrate the CW-IM measurement of atmospheric O2. The CO2 and O2 measurements are being evaluated for application to the active sensing of CO2 emissions over nights days and seasons (ASCENDS) mission described in the 2007 National Research Council's Decadal Survey. The O2 measurement takes advantage of the fact that O2 is a well mixed gas to allow the determination of the CO2 dry air mixing ratio, which is the required product for the ASCENDS mission. The Raman amplifier development has been focused on optimizing fiber designs to limit stimulated Brillouin scattering (SBS), which is a nonlinear process typically limiting this type of amplifier from generating high power narrow linewidth outputs. This work has centered around two approaches, varying the fiber core diameter to broaden the Brillouin gain curve and designing transverse fiber doping profiles which serve to separate the acoustic and optical wave overlap responsible for SBS. The most recent amplifier is producing 1.5 Watts of average power while maintaining the narrow linewidth of the seed laser (~3 MHz). The latest amplifier has been integrated with the CO2 EDU and initial ground testing was performed at the ITT ground test facility in New Haven, Indiana. The transmitter has subsequently been integrated into a NASA DC-8 rack and is currently being flown on the NASA DC-8. We discuss results from these ground and flight measurements in addition to the discussion of the amplifier design and our plans for scaling the design to space. This document is not subject to the controls of the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR).

The 2014 ASCENDS Field Campaign - a Carbon Dioxide Laser Absorption Spectrometer Perspective

NASA Astrophysics Data System (ADS)

Spiers, G. D.; Menzies, R. T.; Jacob, J. C.; Geier, S.; Fregoso, S. F.

2014-12-01

NASA's ASCENDS mission has been flying several candidate lidar instruments on board the NASA DC-8 aircraft to obtain column integrated measurements of Carbon Dioxide. Each instrument uses a different approach to making the measurement and combined they have allowed for the informed development of the ASCENDS mission measurement requirements(1). The JPL developed Carbon Dioxide Laser Absorption Spectrometer, CO2LAS is one of these instruments. The CO2LAS measures the weighted, column averaged carbon dioxide between the aircraft and the ground using a continuous-wave heterodyne technique. The instrument operates at a 2.05 micron wavelength optimized for enhancing sensitivity to boundary layer carbon dioxide. Since the 2013 field campaign the instrument has undergone significant upgrades that improve the data collection efficiency and instrument stability and has recently been re-integrated onto the NASA DC-8 for the August 2014 ASCENDS field campaign. This presentation will summarize the instrument and algorithm improvements and review the 2014 field campaign flights and preliminary results. (1) Abshire, J.B. et al., "An overview of NASA's ASCENDS Mission lidar measurement requirements", submitted to 2014 Fall AGU Conference.

Hemolytic anemia caused by aortic flap and inversion of felt strip after ascending aorta replacement.

PubMed

Sakaguchi, Masayuki; Takano, Tamaki

2016-08-02

Hemolysis related to a kinked prosthetic graft or inner felt strip is a very rare complication after aortic surgery. We describe herein a case of hemolytic anemia that developed due to aortic flap of the dissection and inversion of an inner felt strip that was applied at the proximal anastomosis of a replaced ascending aorta 10 years previously. A 74-year-old woman presented with consistent hemolytic anemia 10 years after replacement of the ascending aorta to treat Stanford type A acute aortic dissection. The cause of hemolysis was attributed to mechanical injury of red blood cells at a site of stenosis caused by aortic flap of the dissection and inversion of the felt strip used for the proximal anastomosis. Repeated resection of the strip and graft replacement of the ascending aorta resolved this problem. We considered that blood flow disrupted by a jet of blood at the site of the proximal inner felt strip was the cause of severe hemolysis, we describe rare hemolytic anemia at the site of aortic flap and inverted felt strip after replacement of the ascending aorta.

EphrinB3/EphA4-mediated guidance of ascending and descending spinal tracts.

PubMed

Paixão, Sónia; Balijepalli, Aarathi; Serradj, Najet; Niu, Jingwen; Luo, Wenqin; Martin, John H; Klein, Rüdiger

2013-12-18

The spinal cord contains many descending and ascending longitudinal tracts whose development appears to be controlled by distinct guidance systems. We identified a population of dorsal spinal neurons marked by coexpression of the transcription factor Zic2 and the guidance receptor EphA4. Zic2+;EphA4+ neurons are surrounded by mechanosensory terminals, suggesting innervation by mechanoreceptor afferents. Their axons form an ipsilateral ascending pathway that develops during embryogenesis and projects within the ventral aspect of the dorsal funiculus, the same location as the descending corticospinal tract (CST), which develops postnatally. Interestingly, the same guidance mechanism, namely, ephrinB3-induced EphA4 forward signaling, is required for the guidance of both ascending and descending axon tracts. Our analysis of conditional EphA4 mutant mice also revealed that the development of the dorsal funiculus occurs independently of EphA4 expression in descending CST axons and is linked to the distribution of Zic2+;EphA4+ spinal neurons and the formation of the ascending pathway. Copyright © 2013 Elsevier Inc. All rights reserved.

Deformation of the Augustine Volcano, Alaska, 1992-2005, measured by ERS and ENVISAT SAR interferometry

USGS Publications Warehouse

Lee, Chang-Wook; Lu, Zhong; Kwoun, Oh-Ig; Won, Joong-Sun

2008-01-01

The Augustine Volcano is a conical-shaped, active stratovolcano located on an island of the same name in Cook Inlet, about 290 km southwest of Anchorage, Alaska. Augustine has experienced seven significant explosive eruptions - in 1812, 1883, 1908, 1935, 1963, 1976, 1986, and in January 2006. To measure the ground surface deformation of the Augustine Volcano before the 2006 eruption, we applied satellite radar interferometry using Synthetic Aperture Radar (SAR) images from three descending and three ascending satellite tracks acquired by European Remote Sensing Satellite (ERS) 1 and 2 and the Environment Satellite (ENVISAT). Multiple interferograms were stacked to reduce artifacts caused by atmospheric conditions, and we used a singular value decomposition method to retrieve the temporal deformation history from several points on the island. Interferograms during 1992 and 2005 show a subsidence of about 1-3 cm/year, caused by the contraction of pyroclastic flow deposits from the 1986 eruption. Subsidence has decreased exponentially with time. Multiple interferograms between 1992 and 2005 show no significant inflation around the volcano before the 2006 eruption. The lack of a pre-eruption deformation signal suggests that the deformation signal from 1992 to August 2005 must have been very small and may have been obscured by atmospheric delay artifacts. 

NASA scientists are flying over Alaska

NASA Image and Video Library

2017-08-29

As part of the Arctic Boreal Vulnerability Experiment (ABoVE), NASA scientists are flying over Alaska and Canada, measuring the elevation of rivers and lakes to study how thawing permafrost affects hydrology in the landscape. This view of was taken from NASA’s DC-8 “flying laboratory” as part of the Active Sensing of CO2 Emissions over Nights, Days and Seasons (ASCENDS) experiment. Scientists on NASA’s Air Surface, Water and Ocean Topography (AirSWOT) mission have been flying over the same location, investigating how water levels in the Arctic landscape change as permafrost thaws. Under typical conditions, the frozen layer of soil keeps water from sinking into the ground and percolating away. As permafrost thaws, the water has new ways to move between rivers and lakes, which can raise or lower the elevation of the bodies of water. These changes in water levels will have effects on Arctic life— plants, animals, and humans—in the near future. Credit: NASA/Peter Griffith NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Anterior insula coordinates hierarchical processing of tactile mismatch responses

PubMed Central

Allen, Micah; Fardo, Francesca; Dietz, Martin J.; Hillebrandt, Hauke; Friston, Karl J.; Rees, Geraint; Roepstorff, Andreas

2016-01-01

The body underlies our sense of self, emotion, and agency. Signals arising from the skin convey warmth, social touch, and the physical characteristics of external stimuli. Surprising or unexpected tactile sensations can herald events of motivational salience, including imminent threats (e.g., an insect bite) and hedonic rewards (e.g., a caressing touch). Awareness of such events is thought to depend upon the hierarchical integration of body-related mismatch responses by the anterior insula. To investigate this possibility, we measured brain activity using functional magnetic resonance imaging, while healthy participants performed a roving tactile oddball task. Mass-univariate analysis demonstrated robust activations in limbic, somatosensory, and prefrontal cortical areas previously implicated in tactile deviancy, body awareness, and cognitive control. Dynamic Causal Modelling revealed that unexpected stimuli increased the strength of forward connections along a caudal to rostral hierarchy—projecting from thalamic and somatosensory regions towards insula, cingulate and prefrontal cortices. Within this ascending flow of sensory information, the AIC was the only region to show increased backwards connectivity to the somatosensory cortex, augmenting a reciprocal exchange of neuronal signals. Further, participants who rated stimulus changes as easier to detect showed stronger modulation of descending PFC to AIC connections by deviance. These results suggest that the AIC coordinates hierarchical processing of tactile prediction error. They are interpreted in support of an embodied predictive coding model where AIC mediated body awareness is involved in anchoring a global neuronal workspace. PMID:26584870

A systematic review of primary endovascular repair of the ascending aorta.

PubMed

Muetterties, Corbin E; Menon, Rohan; Wheatley, Grayson H

2018-01-01

Endovascular repair of the ascending aorta is currently limited to patients at high surgical risk with aortic diseases originating above the sinotubular junction. A number of different endovascular technologies and approaches have been used, although no consensus exists regarding a standardized technique. To better understand real-world endovascular approaches to the ascending aorta, we performed a comprehensive review of the types of endovascular aortic stents and associated vascular access used in repair of the ascending aorta. A search of the MEDLINE database was conducted from January 1, 1995, through January 31, 2017, with the search term "ascending aortic stent." Studies involving endovascular stenting in which the primary therapy was confined exclusively to the ascending aorta were included. Studies involving hybrid arch procedures and surgical replacement of the ascending aorta associated with aortic stenting were excluded. The type of aortic stent, underlying aortic disease, and surgical approach were recorded along with outcomes, need for reinterventions, and follow-up. A total of 46 publications that focused on primary endovascular repair of the ascending aorta were identified. Thirteen different aortic stent grafts of various designs were used in 118 total patients. The most commonly used device types were thoracic stents (n = 84 [71.2%]) along with abdominal cuffs (n = 13 [11%]) and custom-made grafts (n = 12 [10.2%]). The most commonly treated aortic disease was type A aortic dissection (n = 59 [50%]), followed by aortic pseudoaneurysm (n = 35 [29.7%]), aortic aneurysm (n = 6 [5.1%]), penetrating atherosclerotic ulcer (n = 5 [4.2%]), and acute aortic rupture (n = 3 [2.5%]). Femoral arterial access was used in 62.7% of patients (n = 74); transapical (n = 17 [14.4%]), carotid (n = 15 [12.7%]), and axillary (n = 8 [6.8%]) approaches were also used. The overall type I endoleak rate was 18.6% (n = 22), with 11 patients (9.3%) requiring reintervention. Other complications included all-cause mortality (n = 18 [15.2%]), conversions to open surgery (n = 4 [3.4%]), and cerebrovascular complications (n = 4 [3.4%]). Aorta-related mortality was 5% (n = 6), and average follow-up was 17.2 months. Despite the absence of a dedicated aortic stent graft for the ascending aorta, patients with a range of ascending aortic diseases are being successfully treated by endovascular technologies. For optimal outcomes, patient selection is critical to align aortic anatomy with the limited device sizing options, and it should be reserved for patients at high surgical risk. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Does three-dimensional transesophageal echocardiography provide incremental value in percutaneous closure of ascending aortic pseudoaneurysm?

PubMed

Elkaryoni, Ahmed; Hsiung, Ming C; Arisha, Mohammed J; Ahmad, Amier; Nanda, Navin C; Mohamed, Ahmed H; Attia, Doaa; Sachdeva, Ankush; Singh, Lovepreet; Yin, Wei-Hsian

2017-07-01

Ascending aortic pseudoaneurysms (AO PSAs), if left untreated, are complicated by a high rate of rupture resulting in significant morbidity and mortality. New transcatheter modalities have emerged as acceptable surgical alternatives for their management. We present a case of an ascending aortic PSA in which intraoperative two- and three-dimensional transesophageal echocardiography (2DTEE and 3DTEE) provided a comprehensive assessment of the PSA in pre- and postclosure settings. © 2017, Wiley Periodicals, Inc.

Case report: Open replacement of incomplete semi-circular traumatic ruptures of the ascending and descending aorta.

PubMed

Mytsyk, Miroslawa; Grapow, Martin T R; Shahinian, Jasmin; Maurer, Markus; Gurke, Lorenz; Eckstein, Friedrich S

2016-07-16

An incomplete traumatic rupture of the ascending aorta is a rare but life-threatening condition. Hence, the assessment of the extent of the injury prior to therapy is crucial. We report a case of a 50-year-old male with traumatic aortic rupture who underwent emergency surgery after the evaluation of computed tomography scan (CT-scan). The surgical treatment involved replacement of the ascending aorta and stent implantation in descending aorta due to its covered rupture.

A Theory of Fundamentalism: An Inquiry Into the Origin and Development of the Movement.

DTIC Science & Technology

1995-09-28

Also see Mitchell, The Society of Muslim Brothers. 55. See Ehud Sprinzak, The Ascendance of Israel’s Radical Right , Oxford: Oxford University Press...accepted the proposal. 57. Sprinzak, The Ascendancy of Israel’s Radical Right , writes (p. 65): A most significant response to the crisis of the Yom...to achieve interim agreements with Egypt and Syria. 58. Lustick, For the Land and the Lord, p. 42. 59. Sprinzak, The Ascendancy of Israel’s Radical

Seawifs Technical Report Series. Volume 2: Analysis of Orbit Selection for Seawifs: Ascending Versus Descending Node

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Gregg, Watson W.

1992-01-01

Due to range safety considerations, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color instrument may be required to be launched into a near-noon descending node, as opposed to the ascending node used by the predecessor sensor, the Coastal Zone Color Scanner (CZCS). The relative importance of ascending versus descending near-noon orbits was assessed here to determine if descending node will meet the scientific requirements of SeaWiFS. Analyses focused on ground coverage, local times of coverage, solar and viewing geometries (zenith and azimuth angles), and sun glint. Differences were found in the areas covered by individual orbits, but were not important when taken over a 16 day repeat time. Local time of coverage was also different: for ascending node orbits the Northern Hemisphere was observed in the morning and the Southern Hemisphere in the afternoon, while for descending node orbits the Northern Hemisphere was observed in the afternoon and the Southern in the morning. There were substantial differences in solar azimuth and spacecraft azimuth angles both at equinox and at the Northern Hemisphere summer solstice. Negligible differences in solar and spacecraft zenith angles, relative azimuth angles, and sun glint were obtained at the equinox. However, large differences were found in solar zenith angles, relative azimuths, and sun glint for the solstice. These differences appeared to compensate across the scan, however, an increase in sun glint in descending node over that in ascending node on the western part of the scan was compensated by a decrease on the eastern part of the scan. Thus, no advantage or disadvantage could be conferred upon either ascending node or descending node for noon orbits. Analyses were also performed for ascending and descending node orbits that deviated from a noon equator crossing time. For ascending node, afternoon orbits produced the lowest mean solar zenith angles in the Northern Hemisphere, and morning orbits produced the lowest angles for the Southern Hemisphere. For descending node, morning orbits produced the lowest mean solar zenith angles for the Northern Hemisphere; afternoon orbits produced the lowest angles for the Southern Hemisphere.

Sleep Neurobiology from a Clinical Perspective

PubMed Central

España, Rodrigo A.; Scammell, Thomas E.

2011-01-01

Many neurochemical systems interact to generate wakefulness and sleep. Wakefulness is promoted by neurons in the pons, midbrain, and posterior hypothalamus that produce acetylcholine, norepinephrine, dopamine, serotonin, histamine, and orexin/hypocretin. Most of these ascending arousal systems diffusely activate the cortex and other forebrain targets. NREM sleep is mainly driven by neurons in the preoptic area that inhibit the ascending arousal systems, while REM sleep is regulated primarily by neurons in the pons, with additional influence arising in the hypothalamus. Mutual inhibition between these wake- and sleep-regulating regions likely helps generate full wakefulness and sleep with rapid transitions between states. This up-to-date review of these systems should allow clinicians and researchers to better understand the effects of drugs, lesions, and neurologic disease on sleep and wakefulness. Citation: España RA; Scammell TE. Sleep neurobiology from a clinical perspective. SLEEP 2011;34(7):845-858. PMID:21731134

Risk and panic in late modernity: implications of the converging sites of social anxiety.

PubMed

Hier, Sean P

2003-03-01

Comparing moral panic with the potential catastrophes of the risk society, Sheldon Ungar contends that new sites of social anxiety emerging around nuclear, medical, environmental and chemical threats have thrown into relief many of the questions motivating moral panic research agendas. He argues that shifting sites of social anxiety necessitate a rethinking of theoretical, methodological and conceptual issues related to processes of social control, claims making and general perceptions of public safety. This paper charts an alternative trajectory, asserting that analytic priority rests not with an understanding of the implications of changing but converging sites of social anxiety. Concentrating on the converging sites of social anxiety in late modernity, the analysis forecasts a proliferation of moral panics as an exaggerated symptom of the heightened sense of uncertainty purported to accompany the ascendency of the risk society.

Observations of Convective and Dynamical Instabilities in Tropopause Folds and their Contribution to Stratosphere-Troposphere Exchange

NASA Technical Reports Server (NTRS)

Cho, John Y. N.; Newell, Reginald E.; Bui, T. Paul; Browell, Edward V.; Fenn, Martha A.; Gary, Bruce L.; Mahoney, Michael J.; Gregory, Gerald L.; Sachse, Glen W.; Vay, Stephanie A.

1999-01-01

With aircraft-mounted in-situ and remote sensing instruments for dynamical, thermal. and chemical measurements, we studied two cases of tropopause folding. In both folds we found Kelvin-Helmholtz billows with horizontal wavelength of about 900 m and thickness of about 120 m. In one case the instability was effectively mixing the bottomside of the fold, leading to the transfer of stratospheric air into the troposphere. Also we discovered in both cases small-scale secondary ozone maxima shortly after the aircraft ascended past the topside of the fold that corresponded to regions of convective instability. We interpreted this phenomenon as convectively breaking gravity waves. Therefore, we posit that convectively breaking gravity waves acting on tropopause folds must be added to the list of important irreversible mixing mechanisms leading to stratosphere-troposphere exchange.

Ideological Think Tanks in the States: An Inventory of Their Prevalence, Networks, and Higher Education Policy Activity

ERIC Educational Resources Information Center

Ness, Erik C.; Gándara, Denisa

2014-01-01

This study takes an inventory of a particular type of intermediary organization ascendant within the state-level higher education policy: ideological think tanks. Our inventory identifies 99 think tanks: 59 affiliated with the conservative State Policy Network and 40 with the Progressive States Network. The analysis shows that state-level…

Adaptation to Altitude as a Vehicle for Experiential Learning of Physiology by University Undergraduates

ERIC Educational Resources Information Center

Weigle, David S.; Buben, Amelia; Burke, Caitlin C.; Carroll, Nels D.; Cook, Brett M.; Davis, Benjamin S.; Dubowitz, Gerald; Fisher, Rian E.; Freeman, Timothy C.; Gibbons, Stephen M.; Hansen, Hale A.; Heys, Kimberly A.; Hopkins, Brittany; Jordan, Brittany L.; McElwain, Katherine L.; Powell, Frank L.; Reinhart, Katherine E.; Robbins, Charles D.; Summers, Cameron C.; Walker, Jennifer D.; Weber, Steven S.; Weinheimer, Caroline J.

2007-01-01

In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation.…

Dependence of energy characteristics of ascending swirling air flow on velocity of vertical blowing

NASA Astrophysics Data System (ADS)

Volkov, R. E.; Obukhov, A. G.; Kutrunov, V. N.

2018-05-01

In the model of a compressible continuous medium, for the complete Navier-Stokes system of equations, an initial boundary problem is proposed that corresponds to the conducted and planned experiments and describes complex three-dimensional flows of a viscous compressible heat-conducting gas in ascending swirling flows that are initiated by a vertical cold blowing. Using parallelization methods, three-dimensional nonstationary flows of a polytropic viscous compressible heat-conducting gas are constructed numerically in different scaled ascending swirling flows under the condition when gravity and Coriolis forces act. With the help of explicit difference schemes and the proposed initial boundary conditions, approximate solutions of the complete system of Navier-Stokes equations are constructed as well as the velocity and energy characteristics of three-dimensional nonstationary gas flows in ascending swirling flows are determined.

Comparison of the structure of the aortic valve and ascending aorta in adults having aortic valve replacement for aortic stenosis versus for pure aortic regurgitation and resection of the ascending aorta for aneurysm.

PubMed

Roberts, William Clifford; Vowels, Travis James; Ko, Jong Mi; Filardo, Giovanni; Hebeler, Robert Frederick; Henry, Albert Carl; Matter, Gregory John; Hamman, Baron Lloyd

2011-03-01

There is debate concerning whether an aneurysmal ascending aorta should be replaced when associated with a dysfunctioning aortic valve that is to be replaced. To examine this issue, we divided the patients by type of aortic valve dysfunction-either aortic stenosis (AS) or pure aortic regurgitation (AR)-something not previously undertaken. Of 122 patients with ascending aortic aneurysm (unassociated with aortitis or acute dissection), the aortic valve was congenitally malformed (unicuspid or bicuspid) in 58 (98%) of the 59 AS patients, and in 38 (60%) of the 63 pure AR patients. Ascending aortic medial elastic fiber loss (EFL) (graded 0 to 4+) was zero or 1+ in 53 (90%) of the AS patients, in 20 (53%) of the 38 AR patients with bicuspid valves, and in all 12 AR patients with tricuspid valves unassociated with the Marfan syndrome. An unadjusted analysis showed that, among the 96 patients with congenitally malformed valves, the 38 AR patients had a significantly higher likelihood of 2+ to 4+ EFL than the 58 AS patients (crude odds ratio: 8.78; 95% confidence interval: 2.95, 28.13). These data strongly suggest that the type of aortic valve dysfunction-AS versus pure AR-is very helpful in predicting loss of aortic medial elastic fibers in patients with ascending aortic aneurysms and aortic valve disease.

Endogenous flow-induced nitric oxide reduces superoxide-stimulated Na/H exchange activity via PKG in thick ascending limbs

PubMed Central

Garvin, Jeffrey L.

2014-01-01

Luminal flow stimulates endogenous nitric oxide (NO) and superoxide (O2−) production by renal thick ascending limbs (TALs). The delicate balance between these two factors regulates Na transport in TALs; NO enhances natriuresis, whereas O2− augments Na absorption. Endogenous, flow-stimulated O2− enhances Na/H exchange (NHE). Flow-stimulated NO reduces flow-induced O2−, a process mediated by cGMP-dependent protein kinase (PKG). However, whether flow-stimulated, endogenously-produced NO diminishes O2−-stimulated NHE activity and the signaling pathway involved are unknown. We hypothesized that flow-induced NO reduces the stimulation of NHE activity caused by flow-induced O2− via PKG in TALs. Intracellular pH recovery after an acid load was measured as an indicator of NHE activity in isolated, perfused rat TALs. l-Arginine, the NO synthase substrate, decreased NHE activity by 34 ± 5% (n = 5; P < 0.04). The O2− scavenger tempol decreased NHE activity by 46 ± 8% (n = 6; P < 0.004) in the absence of NO. In the presence of l-arginine, the inhibitory effect of tempol on NHE activity was reduced to −19 ± 6% (n = 6; P < 0.03). The soluble guanylate cyclase inhibitor LY-83583 blocked the effect of l-arginine thus restoring tempol's effect on NHE activity to −42 ± 4% (n = 6; P < 0.0005). The PKG inhibitor KT-5823 also inhibited l-arginine's effect on tempol-reduced NHE activity (−43 ± 5%; n = 5; P < 0.03). We conclude that flow-induced NO reduces the stimulatory effect of endogenous, flow-induced O2− on NHE activity in TALs via an increase in cGMP and PKG activation. PMID:25503735

Deriving temporally continuous soil moisture estimations at fine resolution by downscaling remotely sensed product

NASA Astrophysics Data System (ADS)

Jin, Yan; Ge, Yong; Wang, Jianghao; Heuvelink, Gerard B. M.

2018-06-01

Land surface soil moisture (SSM) has important roles in the energy balance of the land surface and in the water cycle. Downscaling of coarse-resolution SSM remote sensing products is an efficient way for producing fine-resolution data. However, the downscaling methods used most widely require full-coverage visible/infrared satellite data as ancillary information. These methods are restricted to cloud-free days, making them unsuitable for continuous monitoring. The purpose of this study is to overcome this limitation to obtain temporally continuous fine-resolution SSM estimations. The local spatial heterogeneities of SSM and multiscale ancillary variables were considered in the downscaling process both to solve the problem of the strong variability of SSM and to benefit from the fusion of ancillary information. The generation of continuous downscaled remote sensing data was achieved via two principal steps. For cloud-free days, a stepwise hybrid geostatistical downscaling approach, based on geographically weighted area-to-area regression kriging (GWATARK), was employed by combining multiscale ancillary variables with passive microwave remote sensing data. Then, the GWATARK-estimated SSM and China Soil Moisture Dataset from Microwave Data Assimilation SSM data were combined to estimate fine-resolution data for cloudy days. The developed methodology was validated by application to the 25-km resolution daily AMSR-E SSM product to produce continuous SSM estimations at 1-km resolution over the Tibetan Plateau. In comparison with ground-based observations, the downscaled estimations showed correlation (R ≥ 0.7) for both ascending and descending overpasses. The analysis indicated the high potential of the proposed approach for producing a temporally continuous SSM product at fine spatial resolution.

NP001 regulation of macrophage activation markers in ALS: A phase I clinical and biomarker study

PubMed Central

MILLER, ROBERT G.; ZHANG, RONGZHEN; BLOCK, GILBERT; KATZ, JONATHAN; BAROHN, RICHARD; KASARSKIS, EDWARD; FORSHEW, DALLAS; GOPALAKRISHNAN, VIDHYA; MCGRATH, MICHAEL S.

2017-01-01

This is a phase I, placebo-controlled, single ascending dose safety and tolerability study of NP001 in patients with ALS. NP001 is a novel regulator of inflammatory macrophages and monocytes. As ALS progression is thought to be related to neuroinflammation, an additional objective of the study was to assess the effects of NP001 administration on monocyte activation markers. Thirty-two ALS patients were enrolled and received either placebo (eight) or one of four (six at each dose) ascending single i.v. doses (0.2, 0.8, 1.6 and 3.2 mg/kg NP001). Patients were monitored for safety, and blood monocyte immune activation markers CD16 and HLA-DR were assessed pre- and 24 h post-dosing. Changes from baseline were calculated. Results showed that NP001 was generally safe and well tolerated. Importantly, a single dose of NP001 caused a dose-dependent reduction in expression of monocyte CD16, a marker of monocyte activation/inflammation. Additionally, monocyte HLA-DR expression was also decreased in those patients with elevated values at baseline. In conclusion, these data indicate that NP001 has an acute effect on inflammatory monocytes in ALS patient blood. The potential for modulation of inflammation in the context of ALS disease progression will require further study with long-term follow-up. PMID:25192333

The role of the dopaminergic projections in MFB self-stimulation.

PubMed

Gallistel, C R

1986-11-01

Psychophysical experiments indicate that the first stage of the reward pathway in medial forebrain bundle self-stimulation consists of small myelinated descending axons. Pharmacological experiments show that neuroleptics attenuate or abolish the rewarding effect. This had led to the hypothesis that the descending myelinated axons synapse on an ascending dopaminergic second stage projection. 2-Deoxy-[14C]glucose autoradiography in self-stimulating animals or animals receiving automatically administered rewarding stimulation after treatment with reward-blocking doses of pimozide reveals activation of a descending myelinated system but no stimulation-produced activation of an ascending dopaminergic projection system, even though the autoradiographic method reveals the mild elevations and depressions of activity in dopaminergic terminal fields consequent upon injections of neuroleptics and amphetamine, respectively, and the strong activation of the nigrostriatal projection produced by stimulating directly in the substantia nigra. When the effects of neuroleptics and clonidine are measured by the psychophysical method (that is, by lateral shifts in the rate-frequency function), it is found that both drugs produce only gradual and rather small attenuations of rewarding efficacy up to doses at which it is no longer possible to measure their effects. It is suggested that, for neuroleptics at least, the rewarding effect abruptly fails at these doses. It is further suggested that these drugs do not act on the rewarding pathway itself, but on the process by which the rewarding signal is converted to an enduring rewarding effect.

The role of the dopaminergic projections in MFB self-stimulation.

PubMed

Gallistel, C R

1986-06-01

Psychophysical experiments indicate that the first stage of the reward pathway in medial forebrain bundle self-stimulation consists of small myelinated descending axons. Pharmacological experiments show that neuroleptics attenuate or abolish the rewarding effect. This had led to the hypothesis that the descending myelinated axons synapse on an ascending dopaminergic second stage projection. 2-Deoxy-[14C]glucose autoradiography in self-stimulating animals or animals receiving automatically administered rewarding stimulation after treatment with reward-blocking doses of pimozide reveals activation of a descending myelinated system but no stimulation-produced activation of an ascending dopaminergic projection system, even though the autoradiographic method reveals the mild elevations and depressions of activity in dopaminergic terminal fields consequent upon injections of neuroleptics and amphetamine, respectively, and the strong activation of the nigrostriatal projection produced by stimulating directly in the substantia nigra. When the effects of neuroleptics and clonidine are measured by the psychophysical method (that is, by lateral shifts in the rate-frequency function), it is found that both drugs produce only gradual and rather small attenuations of rewarding efficacy up to doses at which it is no longer possible to measure their effects. It is suggested that, for neuroleptics at least, the rewarding effect abruptly fails at these doses. It is further suggested that these drugs do not act on the rewarding pathway itself, but on the process by which the rewarding signal is converted to an enduring rewarding effect.

Effect of short-term vs. long-term elevation of dietary protein intake on responsiveness of rat thick ascending limbs to peptide hormones.

PubMed

Goldstein, David L; Plaga, Kimberly

2002-10-01

We compared the renal responses of rats on three diet regimens. Rats received either 8% protein food (low-protein, LP) for 10 weeks following weaning, 8% protein for 9 weeks followed by 1 week on 30% protein (short-term high-protein, SHP), or 30% protein for 10 weeks (high-protein, HP). Kidneys from HP rats were enlarged by approximately 50%, or 20% when corrected for body mass. Most of this hypertrophy resulted from enlargement of the inner stripe of the outer medulla, site of the thick ascending limbs (TAL), and TAL from HP rats were larger in diameter. SHP rats had TAL diameters similar to HP rats, but changes in renal mass or height of renal zones did not reach statistical significance. The activity of adenylyl cyclase (AC) in TAL, measured from the accumulation of cAMP in isolated tubules, increased with dose of both arginine vasopressin (AVP) and glucagon in all rats. However, HP rats had significantly higher hormone-induced AC activity than LP or SHP rats, which were not different from each other. Our results suggest that tubule hypertrophy may precede up-regulation of hormone-sensitive AC activity during the progression of renal response to elevated dietary protein.

Fight for your breeding right: hierarchy re-establishment predicts aggression in a social queue

PubMed Central

Wong, Marian; Balshine, Sigal

2011-01-01

Social aggression is one of the most conspicuous features of animal societies, yet little is known about the causes of individual variation in aggression within social hierarchies. Recent theory suggests that when individuals form queues for breeding, variation in social aggression by non-breeding group members is related to their probability of inheriting breeding status. However, levels of aggression could also vary as a temporary response to changes in the hierarchy, with individuals becoming more aggressive as they ascend in rank, in order to re-establish dominance relationships. Using the group-living fish, Neolamprologus pulcher, we show that subordinates became more aggressive after they ascended in rank. Female ascenders exhibited more rapid increases in aggression than males, and the increased aggression was primarily directed towards group members of adjacent rather than non-adjacent rank, suggesting that social aggression was related to conflict over rank. Elevated aggression by ascenders was not sustained over time, there was no relationship between rank and aggression in stable groups, and aggression given by ascenders was not sex-biased. Together, these results suggest that the need to re-establish dominance relationships following rank ascension is an important determinant of variation in aggression in animal societies. PMID:20880857

Fight for your breeding right: hierarchy re-establishment predicts aggression in a social queue.

PubMed

Wong, Marian; Balshine, Sigal

2011-04-23

Social aggression is one of the most conspicuous features of animal societies, yet little is known about the causes of individual variation in aggression within social hierarchies. Recent theory suggests that when individuals form queues for breeding, variation in social aggression by non-breeding group members is related to their probability of inheriting breeding status. However, levels of aggression could also vary as a temporary response to changes in the hierarchy, with individuals becoming more aggressive as they ascend in rank, in order to re-establish dominance relationships. Using the group-living fish, Neolamprologus pulcher, we show that subordinates became more aggressive after they ascended in rank. Female ascenders exhibited more rapid increases in aggression than males, and the increased aggression was primarily directed towards group members of adjacent rather than non-adjacent rank, suggesting that social aggression was related to conflict over rank. Elevated aggression by ascenders was not sustained over time, there was no relationship between rank and aggression in stable groups, and aggression given by ascenders was not sex-biased. Together, these results suggest that the need to re-establish dominance relationships following rank ascension is an important determinant of variation in aggression in animal societies.

Endovascular approach to treat ascending aortic pseudoaneurysm in a patient with previous CABG and very high surgical risk.

PubMed

Zago, Alexandre C; Saadi, Eduardo K; Zago, Alcides J

2011-10-01

Pseudoaneurysm of the ascending aorta is an uncommon pathology and a challenge in high-risk patients who undergo conventional surgery because of high operative morbidity and mortality. Endovascular exclusion of an aortic pseudoaneurysm using an endoprosthesis is a less invasive approach, but few such cases have been reported. Moreover, the use of this approach poses unique therapeutic challenges because there is no specific endoprosthesis for ascending aortic repair, particularly to treat patients with previous coronary artery bypass graft (CABG). We describe the case of a 74-year-old patient who had undergone CABG and later presented with an iatrogenic ascending aortic pseudoaneurysm that occurred during an angiography. This patient was at very high risk for surgical treatment and, therefore, an endovascular approach was adopted: percutaneous coronary intervention for the left main coronary artery, left anterior descending and left circumflex native coronary arteries followed by endovascular endoprosthesis deployment in the ascending aorta to exclude the pseudoaneurysm. Both procedures were successfully performed, and the patient was discharged without complications 4 days later. At 5 months' clinical follow-up, his clinical condition was good and he had no complications. Copyright © 2011 Wiley-Liss, Inc.

Cannabinoid-1 (CB1) receptors regulate colonic propulsion by acting at motor neurons within the ascending motor pathways in mouse colon.

PubMed

Sibaev, Andrei; Yüce, Birol; Kemmer, Markus; Van Nassauw, Luc; Broedl, Ulli; Allescher, Hans D; Göke, Burkhard; Timmermans, Jean-Pierre; Storr, Martin

2009-01-01

Cannabinoid-1 (CB(1)) receptors on myenteric neurons are involved in the regulation of intestinal motility. Our aim was to investigate CB(1) receptor involvement in ascending neurotransmission in mouse colon and to characterize the involved structures by functional and morphological means. Presence of the CB(1) receptor was investigated by RT-PCR, and immunohistochemistry was used for colabeling studies. Myenteric reflex responses were initiated by electrical stimulation (ES) at different distances, and junction potentials (JP) were recorded from circular smooth muscle cells by intracellular recording in an unpartitioned and a partitioned recording chamber. In vivo colonic propulsion was tested in wild-type and CB(1)(-/-) mice. Immunostaining with the cytoskeletal marker peripherin showed CB(1) immunoreactivity both on Dogiel type I and type II neurons. Further neurochemical characterization revealed CB(1) on choline acetyltransferase-, calretinin-, and 5-HT-immunopositive myenteric neurons, but nitrergic neurons appeared immunonegative for CB(1) immunostaining. Solitary spindle-shaped CB(1)-immunoreactive cells in between smooth muscle cells lacked specific markers for interstitial cells of Cajal or glial cells. ES elicited neuronally mediated excitatory JP (EJP) and inhibitory JP. Gradual increases in distance resulted in a wave-like EJP with EJP amplitudes being maximal at the location of stimulating electrode 6 and a maximal EJP projection distance of approximately 18 mm. The CB(1) receptor agonist WIN 55,212-2 reduced the amplitude of EJP and was responsible for shortening the oral spreading of the excitatory impulse. In a partitioned chamber, WIN 55,212-2 reduced EJP at the separated oral sites, proving that CB(1) activation inhibits interneuron-mediated neurotransmission. These effects were absent in the presence of the CB(1) antagonist SR141716A, which, when given alone, had no effect. WIN 55,212-2 inhibited colonic propulsion in wild-type mice but not in SR141716A-pretreated wild-type or CB(1)(-/-) mice. Activation of the CB(1) receptor modulates excitatory cholinergic neurotransmission in mouse colon by reducing amplitude and spatial spreading of the ascending electrophysiological impulses. This effect on electrophysiological spreading involves CB(1)-mediated effects on motor neurons and ascending interneurons and is likely to underlie the here reported in vivo reduction in colonic propulsion.

Single coronary artery with bicuspid aortic valve stenosis and aneurysm of the ascending aorta: report of a case.

PubMed

Ishida, Narihiro; Shimabukuro, Katsuya; Matsuno, Yukihiro; Ogura, Hiroki; Takemura, Hirofumi

2014-03-01

A 73-year-old man with a severely stenosed bicuspid valve and an aneurysm of the ascending aorta underwent valve and aortic surgery. Preoperative imaging revealed a single coronary artery arising from the right side of the sinus of Valsalva and a branch that perfused into the left side of the heart to pass through the front of the pulmonary artery. We replaced the aortic valve and ascending aorta, painstakingly avoiding damage to the coronary artery and obstruction of the sole coronary ostium.

Percutaneous closure of a large ascending aortic pseudoaneurysm.

PubMed

Nogueira, Marta Afonso; Fiarresga, António; de Sousa, Lídia; Galrinho, Ana; Santos, Ninel; Nobre, Isabel; Laranjeira, Álvaro; Cruz Ferreira, Rui

2016-02-01

Pseudoaneurysm of the ascending aorta is a rare complication, usually after thoracic surgery or trauma. Since surgical repair is associated with very high morbidity and mortality, percutaneous closure has been described as an alternative. In this regard, we present a case in which a symptomatic large pseudoaneurysm of the ascending aorta was treated percutaneously due to the high surgical risk. Despite the technical difficulties, this procedure had a good final result followed by clinical success. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Pathologic aneurysmal dilation of the ascending aorta and dilation of the main pulmonary artery in patients with Kabuki syndrome: valve-sparing aortic root replacement.

PubMed

Dyamenahalli, Umesh; Abraham, Boban; Fontenot, Eudice; Prasad, Vinay; Imamura, Michiaki

2007-01-01

We report the aneurysmal dilation of the ascending aorta and the main pulmonary artery in 2 children with Kabuki syndrome. In 1 patient, there was progressive aneurysmal dilation of the ascending aorta necessitating aortoplasty. Histologic examination of the resected aorta revealed disrupted and fragmented elastic fibers in the medial layer, along with mucinous degeneration of the aortic wall. This is the first recognition and report of these findings as part of the Kabuki syndrome.

Patella height is not altered by descending medial open-wedge high tibial osteotomy (HTO) compared to ascending HTO.

PubMed

Krause, Matthias; Drenck, Tobias Claus; Korthaus, Alexander; Preiss, Achim; Frosch, Karl-Heinz; Akoto, Ralph

2018-06-01

The primary purpose of the study was to gain insight into geometric changes of the patellar height (PH) and posterior tibial slope (PTS) after a biplanar ascending medial open-wedge high tibial osteotomy (HTO) compared to biplanar descending medial open-wedge HTO in patients with genu varum. Sixty-four patients (mean age 45.2 ± 8.7 years, females n = 24, males n = 40) with varus malalignment and medial gonarthrosis were retrospectively studied. Patients received either a biplanar ascending or descending medial open-wedge HTO. Radiographic analysis included the assessment of standing total leg axis, PH, and PTS prior to and after surgery. In the ascending HTO group, PH decreased significantly by 4.0% (p = 0.037, Caton-Deschamps index) after an average leg axis valgus-producing correction of 7.1° ± 2.8°. In the descending HTO group, with an average leg axis correction of 7.0° ± 3.7°, there were no significant PH changes. There were no significant differences between the ascending and descending HTO groups regarding PTS or leg axis. The mean post-operative leg axis between ascending (1.6° ± 1.9°) and descending HTO (1.9° ± 2.4°) was not significantly different. Compared to the biplanar ascending medial open-wedge HTO, the descending HTO did not influence patella height or increase the posterior tibial slope. In order to respect patellofemoral and slope-related knee kinematics, a biplanar descending medial open-wedge HTO has proven useful to control patella height and posterior tibial slope. These findings underscore the importance of the preoperative patella height assessment in the osteotomy planning and subsequent choice of the biplanar osteotomy direction. IV.

Three-dimensional, high-resolution skeletal kinematics of the avian wing and shoulder during ascending flapping flight and uphill flap-running.

PubMed

Baier, David B; Gatesy, Stephen M; Dial, Kenneth P

2013-01-01

Past studies have shown that birds use their wings not only for flight, but also when ascending steep inclines. Uphill flap-running or wing-assisted incline running (WAIR) is used by both flight-incapable fledglings and flight-capable adults to retreat to an elevated refuge. Despite the broadly varying direction of travel during WAIR, level, and descending flight, recent studies have found that the basic wing path remains relatively invariant with reference to gravity. If so, joints undergo disparate motions to maintain a consistent wing path during those specific flapping modes. The underlying skeletal motions, however, are masked by feathers and skin. To improve our understanding of the form-functional relationship of the skeletal apparatus and joint morphology with a corresponding locomotor behavior, we used XROMM (X-ray Reconstruction of Moving Morphology) to quantify 3-D skeletal kinematics in chukars (Alectoris chukar) during WAIR (ascending with legs and wings) and ascending flight (AF, ascending with wings only) along comparable trajectories. Evidence here from the wing joints demonstrates that the glenohumeral joint controls the vast majority of wing movements. More distal joints are primarily involved in modifying wing shape. All bones are in relatively similar orientations at the top of upstroke during both behaviors, but then diverge through downstroke. Total excursion of the wing is much smaller during WAIR and the tip of the manus follows a more vertical path. The WAIR stroke appears "truncated" relative to ascending flight, primarily stemming from ca. 50% reduction in humeral depression. Additionally, the elbow and wrist exhibit reduced ranges of angular excursions during WAIR. The glenohumeral joint moves in a pattern congruent with being constrained by the acrocoracohumeral ligament. Finally, we found pronounced lateral bending of the furcula during the wingbeat cycle during ascending flight only, though the phasic pattern in chukars is opposite of that observed in starlings (Sturnus vulgaris).

Safety and pharmacodynamics of venetoclax (ABT-199) in a randomized single and multiple ascending dose study in women with systemic lupus erythematosus.

PubMed

Lu, P; Fleischmann, R; Curtis, C; Ignatenko, S; Clarke, S H; Desai, M; Wong, S L; Grebe, K M; Black, K; Zeng, J; Stolzenbach, J; Medema, J K

2018-02-01

Objective The anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) may contribute to the pathogenesis of systemic lupus erythematosus. The safety, tolerability, and pharmacodynamics of the selective Bcl-2 inhibitor venetoclax (ABT-199) were assessed in women with systemic lupus erythematosus. Methods A phase 1, double-blind, randomized, placebo controlled study evaluated single ascending doses (10, 30, 90, 180, 300, and 500 mg) and multiple ascending doses (2 cycles; 30, 60, 120, 240, 400, and 600 mg for 1 week, and then 3 weeks off per cycle) of orally administered venetoclax. Eligible participants were aged 18-65 years with a diagnosis of systemic lupus erythematosus for 6 months or more receiving stable therapy for systemic lupus erythematosus (which could have included corticosteroids and/or stable antimalarials). Results All patients (48/48) completed the single ascending dose, 25 continued into the multiple ascending dose, and 44/50 completed the multiple ascending dose; two of the withdrawals (venetoclax 60 mg and 600 mg cohorts) were due to adverse events. Adverse event incidences were slightly higher in the venetoclax groups compared with the placebo groups, with no dose dependence. There were no serious adverse events with venetoclax. The most common adverse events were headache, nausea, and fatigue. Venetoclax 600 mg multiple ascending dose treatment depleted total lymphocytes and B cells by approximately 50% and 80%, respectively. Naive, switched memory, and memory B-cell subsets enriched in autoreactive B cells exhibited dose-dependent reduction of up to approximately 80%. There were no consistent or marked changes in neutrophils, natural killer cells, hemoglobin, or platelets. Conclusions Venetoclax was generally well tolerated in women with systemic lupus erythematosus and reduced total lymphocytes and disease-relevant subsets of antigen-experienced B cells. Registration ClinicalTrials.gov: NCT01686555.

Analysis for orbital rendezvous of Chang'E-5 using SBI technique

NASA Astrophysics Data System (ADS)

Huang, Y.; Shan, Q.; Li, P.

2016-12-01

Chang'E-5 will be launched in later 2017/early 2018 using a new generation rocket from Wenchang satellite launch center, Hainan, China. It is a lunar sampling return mission, and it is the first time for China to carry out orbital rendezvous and docking in the Moon. How to achieve orbital rendezvous successfully in the Moon is very important in Chang'E-5 mission. Orbital rendezvous will be implemented between an orbiter and an ascender 200 km above the Moon. The ground tracking techniques include range, Doppler and VLBI, and they will be used to track the orbiter and the ascender when the ascender is about 70 km farther away from the orbiter. Later the ascender will approach the orbiter automatically. As a successful example, in Chang'E-3, the differential phase delay (delta delay) data between the rover and the lander are obtained with a random error of about 1 ps, and the relative position of the rover is determined with an accuracy of several meters by using same beam VLBI (SBI) technique. Here the application of the SBI technique for Chang'E-5 orbital rendezvous is discussed. SBI technique can be used to track the orbiter and the ascender simultaneously when they are in the same beam. Delta delay of the two probes can be derived, and the measurement accuracy is much higher than that of the traditional VLBI data because of the cancelation of common errors. Theoretically it can result in a more accurate relative orbit between the two probes. In the simulation, different strategies are discussed to analyze the contribution of SBI data to the orbit accuracy improvement especially relative orbit between the orbiter and ascender. The simulation results show that the relative position accuracy of the orbiter and ascender can reach about 1 m with delta delay data of 10 ps.

[Ascending one-dimensional thin layer chromatography in specific blood diagnosis (author's transl)].

PubMed

Bernardelli, B; Masotti, G

1976-01-01

A brief review of the literature on chromatography in forensic haematology is followed by a report of the results obtained by using ascending one-dimensional thin layer chromatography in specific blood diagnosis.

A case of granuloma of the ascending colon due to penetration of Trichuris trichiura.

PubMed

Kojima, Y; Sakuma, H; Izumi, R; Nakagawara, G; Miyazaki, I; Yoshimura, H

1981-01-01

A 33 year-old woman was admitted with chief complaint of abdominal pain and high fever. A barium-enema showed serration and a tumor was seen in the proximal ascending colon. At laparotomy, a localized tumor about 5 cm in diameter was located in the proximal portion of the ascending colon. The operation was made according to the ileoceal resection. On the macroscopic examination of the resected specimen, a small hole penetrating into the subserosa of the ascending colon was noticed and a tumor measuring approximately 3 x 1.2 x 1 cm was located under the hole. A female worm, Trichuris trichiura, was found to be harbored in the adjacent site of the lesion. Histopathologic examination revealed granulomatous tissue reaction due to penetrating of Trichuris trichiura. The patient is in good health now 20 months after operation.

Functional anatomy of the hair follicle: The Secondary Hair Germ.

PubMed

Panteleyev, Andrey A

2018-07-01

The secondary hair germ (SHG)-a transitory structure in the lower portion of the mouse telogen hair follicle (HF)-is directly involved in anagen induction and eventual HF regrowth. Some crucial aspects of SHG functioning and ontogenetic relations with other HF parts, however, remain undefined. According to recent evidence (in contrast to previous bulge-centric views), the SHG is the primary target of anagen-inducing signalling and a source of both the outer root sheath (ORS) and ascending HF layers during the initial (morphogenetic) anagen subphase. The SHG is comprised of two functionally distinct cell populations. Its lower portion (originating from lower HF cells that survived catagen) forms all ascending HF layers, while the upper SHG (formed by bulge-derived cells) builds up the ORS. The predetermination of SHG cells to a specific morphogenetic fate contradicts their attribution to the "stem cell" category and supports SHG designation as a "germinative" or a "founder" cell population. The mechanisms of this predetermination driving transition of the SHG from "refractory" to the "competent" state during the telogen remain unknown. Functionally, the SHG serves as a barrier, protecting the quiescent bulge stem cell niche from the extensive follicular papilla/SHG signalling milieu. The formation of the SHG is a prerequisite for efficient "precommitment" of these cells and provides for easier sensing and a faster response to anagen-inducing signals. In general, the formation of the SHG is an evolutionary adaptation, which allowed the ancestors of modern Muridae to acquire a specific, highly synchronized pattern of hair cycling. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dynamics of two-dimensional bubbles.

PubMed

Piedra, Saúl; Ramos, Eduardo; Herrera, J Ramón

2015-06-01

The dynamics of two-dimensional bubbles ascending under the influence of buoyant forces is numerically studied with a one-fluid model coupled with the front-tracking technique. The bubble dynamics are described by recording the position, shape, and orientation of the bubbles as functions of time. The qualitative properties of the bubbles and their terminal velocities are described in terms of the Eötvos (ratio of buoyancy to surface tension) and Archimedes numbers (ratio of buoyancy to viscous forces). The terminal Reynolds number result from the balance of buoyancy and drag forces and, consequently, is not an externally fixed parameter. In the cases that yield small Reynolds numbers, the bubbles follow straight paths and the wake is steady. A more interesting behavior is found at high Reynolds numbers where the bubbles follow an approximately periodic zigzag trajectory and an unstable wake with properties similar to the Von Karman vortex street is formed. The dynamical features of the motion of single bubbles are compared to experimental observations of air bubbles ascending in a water-filled Hele-Shaw cell. Although the comparison is not strictly valid in the sense that the effect of the lateral walls is not incorporated in the model, most of the dynamical properties observed are in good qualitative agreement with the numerical calculations. Hele-Shaw cells with different gaps have been used to determine the degree of approximation of the numerical calculation. It is found that for the relation between the terminal Reynolds number and the Archimedes number, the numerical calculations are closer to the observations of bubble dynamics in Hele-Shaw cells of larger gaps.

Atmospheric CO2 Concentration Measurements with Clouds from an Airborne Lidar

NASA Astrophysics Data System (ADS)

Mao, J.; Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.; Numata, K.; Chen, J. R.; Sun, X.; DiGangi, J. P.; Choi, Y.

2017-12-01

Globally distributed atmospheric CO2 concentration measurements with high precision, low bias and full seasonal sampling are crucial to advance carbon cycle sciences. However, two thirds of the Earth's surface is typically covered by clouds, and passive remote sensing approaches from space are limited to cloud-free scenes. NASA Goddard is developing a pulsed, integrated-path differential absorption (IPDA) lidar approach to measure atmospheric column CO2 concentrations, XCO2, from space as a candidate for NASA's ASCENDS mission. Measurements of time-resolved laser backscatter profiles from the atmosphere also allow this technique to estimate XCO2 and range to cloud tops in addition to those to the ground with precise knowledge of the photon path-length. We demonstrate this measurement capability using airborne lidar measurements from summer 2017 ASCENDS airborne science campaign in Alaska. We show retrievals of XCO2 to ground and to a variety of cloud tops. We will also demonstrate how the partial column XCO2 to cloud tops and cloud slicing approach help resolving vertical and horizontal gradient of CO2 in cloudy conditions. The XCO2 retrievals from the lidar are validated against in situ measurements and compared to the Goddard Parameterized Chemistry Transport Model (PCTM) simulations. Adding this measurement capability to the future lidar mission for XCO2 will provide full global and seasonal data coverage and some information about vertical structure of CO2. This unique facility is expected to benefit atmospheric transport process studies, carbon data assimilation in models, and global and regional carbon flux estimation.

L-band nighttime scintillations at the northern edge of the EIA along 95°E during the ascending half of the solar cycle 24

NASA Astrophysics Data System (ADS)

Dutta, Barsha; Kalita, Bitap Raj; Bhuyan, Pradip Kumar

2018-04-01

The characteristics of nighttime ionospheric scintillations measured at the L-band frequency of 1.575 GHz over Dibrugarh (27.5°N, 95°E, MLAT ∼ 17°N, 43° dip) during the ascending half of the solar cycle 24 from 2010 to 2014 have been investigated and the results are presented in this paper. The measurement location is within or outside the zone of influence of the equatorial ionization anomaly depending on solar and geomagnetic activity. Maximum scintillation is observed in the equinoxes irrespective of solar activity with clear asymmetry between March and September. The occurrence frequency in the solstices shifts from minimum in the June solstice in low solar activity to a minimum in the December solstice in high solar activity years. A significant positive correlation of occurrence of scintillations in the June solstice with solar activity has been observed. However, earlier reports from the Indian zone (∼75°E) indicate negative or no correlation of scintillation in June solstice with solar activity. Scintillations activity/occurrence in solstices indicates a clear positive correlation with Es recorded simultaneously by a collocated Ionosonde. In equinoxes, maximum scintillations occur in the pre-midnight hours while in solstices the occurrence frequency peaks just after sunset. The incidence of strong scintillations (S4 ≥ 0.4) increases with increase in solar activity. Strong (S4 ≥ 0.4) ionospheric scintillations accompanied by TEC depletions in the pre-midnight period is attributed to equatorial irregularities whereas the dusk period scintillations are related to the sporadic-E activity. Present results thus indicate that the current location at the northern edge of the EIA behaves as low as well as mid-latitude location.

Aortic wrapping for a dilated ascending aorta in bicuspid aortic stenosis.

PubMed

Choi, Min Suk; Jeong, Dong Seop; Lee, Hae Young; Sung, Kiick; Kim, Wook Sung; Lee, Young Tak; Park, Pyo Won

2015-01-01

Ascending aorta wrapping is rarely recommended for the management of dilated aorta, because of late complications. The aim of the present study was to analyze the early and late outcomes of the aortic wrapping technique at the time of aortic valve replacement (AVR) for bicuspid aortic stenosis (BAS). Among patients who underwent primary AVR for BAS between 2002 and 2011, 79 who underwent ascending aortic wrapping (wrapping group) were compared with 144 patients who underwent AVR alone. The preoperative ascending aortic diameters were larger in the wrapping group (40.9±4.2 mm vs. 48.6±4.0 mm, P<0.001). Operative technique was to wrap the ascending aorta transversely with a semi-elliptically resected Dacron graft. The follow-up for the wrapping group was 76.5±35.5 (median 71.1) months. There were no early deaths. Early and late morbidity did not differ between groups. The 24 late deaths, including 10 cardiac-related deaths, occurred in the entire group; 3 sudden deaths occurred only in the AVR group. The 10-year overall survival in the wrapping group was higher than the AVR group (88.1±6.8% vs. 80.0±4.6%, P=0.048). No late aortic complications were detected. The aortic diameter was reduced from 49.5±4.1 mm to 45.3±5.0 mm after wrapping (P<0.001). The aortic wrapping technique may be an option for treating a moderately dilated ascending aorta in selected patients undergoing AVR for BAS. Longer follow-up, however, is necessary to verify later complications.

Aortic expansion rate in patients with dilated post-stenotic ascending aorta submitted only to aortic valve replacement long-term follow-up.

PubMed

Gaudino, Mario; Anselmi, Amedeo; Morelli, Mauro; Pragliola, Claudio; Tsiopoulos, Vasileios; Glieca, Franco; Possati, Gianfederico

2011-08-02

This study was conceived to describe the evolution of aortic dimensions in patients with moderate post-stenotic ascending aorta dilation (50 to 59 mm) submitted to aortic valve replacement (AVR) alone. The appropriate treatment of post-stenotic ascending aorta dilation has been poorly investigated. Ninety-three patients affected by severe isolated calcific aortic valve stenosis in the tricuspid aortic valve accompanied by moderate dilation of the ascending aorta (50 to 59 mm) were submitted to AVR only. All patients were followed for a mean of 14.7 ± 4.8 years by means of periodic clinical evaluations and echocardiography and tomography scans of the thorax. Operative mortality was 1.0% (1 patient). During the follow-up, 16 patients died and 2 had to be reoperated for valve dysfunction. No patients experienced acute aortic events (rupture, dissection, pseudoaneurysm), and no patient had to be reoperated on the aorta. There was not a substantial increase in aortic dimensions: mean aortic diameter was 57 ± 11 mm at the end of the follow-up versus 56 ± 02 mm pre-operatively (p = NS). The mean ascending aorta expansion rate was 0.3 ± 0.2 mm/year. In the absence of connective tissue disorders, AVR alone is sufficient to prevent further aortic expansion in patients with moderate post-stenotic dilation of the ascending aorta. Aortic replacement can probably be reserved for patients with a long life expectancy. Copyright © 2011 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Elastic properties of the young aorta: ex vivo perfusion experiments in a porcine model.

PubMed

Krüger, Tobias; Grigoraviciute, Akvile; Veseli, Kujtim; Schibilsky, David; Wendel, Hans P; Schneider, Wilke; Schlensak, Christian

2015-08-01

To investigate the regional and directional compliance/distensibility of the healthy aorta. Complete fresh porcine aortas (n = 11) were perfused ex vivo under defined haemodynamic parameters using a custom-made pulse duplicator. Both circumferential and longitudinal compliance were measured optically. The pulse duplicator was able to perfuse the entire aorta with arbitrary haemodynamic parameters, generating a physiological pulse curve. Aortic compliance is pressure dependent, as we observed a linear relationship between pressure and distension in the range of 5-200 mmHg; however, above 200 mmHg, the porcine aorta behaved in an inelastic manner. Circumferential compliance was highest in the ascending aorta (24%/100 mmHg) but significantly (P < 0.05) decreased in both the arch (18%/100 mmHg) and the descending aorta (15%/100 mmHg). Longitudinal compliance was highest in the ascending aorta and clearly exceeded circumferential compliance. Compliance was significantly (P < 0.05) higher in the outer curvatures of the ascending aorta and the aortic arch compared with the compliance of the inner curvature at these locations (30%/100 vs 23%/100 mmHg in the ascending aorta and 20%/100 vs 9%/100 mmHg in the arch, respectively). Longitudinal compliance of the ascending aorta, particularly the outer curvature, is predominantly responsible for the 'Windkessel effect'. Pathological changes such as elongation and pronounced angulation of the ascending aorta increase stress on the outer curvature and may be important factors in the development of aortic dissection. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Blood flow characteristics in the ascending aorta after TAVI compared to surgical aortic valve replacement.

PubMed

Trauzeddel, Ralf Felix; Löbe, Ulrike; Barker, Alex J; Gelsinger, Carmen; Butter, Christian; Markl, Michael; Schulz-Menger, Jeanette; von Knobelsdorff-Brenkenhoff, Florian

2016-03-01

Ascending aortic blood flow characteristics are altered after aortic valve surgery, but the effect of transcatheter aortic valve implantation (TAVI) is unknown. Abnormal flow may be associated with aortic and cardiac remodeling. We analyzed blood flow characteristics in the ascending aorta after TAVI in comparison to conventional stented aortic bioprostheses (AVR) and healthy subjects using time-resolved three-dimensional flow-sensitive cardiovascular magnetic resonance imaging (4D-flow MRI). Seventeen patients with TAVI (Edwards Sapien XT), 12 with AVR and 9 healthy controls underwent 4D-flow MRI of the ascending aorta. Target parameters were: severity of vortical and helical flow pattern (semiquantitative grading from 0 = none to 3 = severe) and the local distribution of systolic wall shear stress (WSSsystole). AVR revealed significantly more extensive vortical and helical flow pattern than TAVI (p = 0.042 and p = 0.002) and controls (p < 0.001 and p = 0.001). TAVI showed significantly more extensive vortical flow than controls (p < 0.001). Both TAVI and AVR revealed marked blood flow eccentricity (64.7 and 66.7%, respectively), whereas controls showed central blood flow (88.9%). TAVI and AVR exhibited an asymmetric distribution of WSSsystole in the mid-ascending aorta with local maxima at the right anterior aortic wall and local minima at the left posterior wall. In contrast, controls showed a symmetric distribution of WSSsystole along the aortic circumference. Blood flow was significantly altered in the ascending aorta after TAVI and AVR. Changes were similar regarding WSSsystole distribution, while TAVI resulted in less helical and vortical blood flow.

Differences in the Thoracic Aorta by Region and Sex in a Murine Model of Marfan Syndrome.

PubMed

Jiménez-Altayó, Francesc; Siegert, Anna-Maria; Bonorino, Fabio; Meirelles, Thayna; Barberà, Laura; Dantas, Ana P; Vila, Elisabet; Egea, Gustavo

2017-01-01

Marfan syndrome (MFS) is a hereditary disorder of the connective tissue that causes life-threatening aortic aneurysm, which initiates at the aortic root and can progress into the ascending portion. However, analysis of ascending aorta reactivity in animal models of MFS has remained elusive. Epidemiologic evidence suggests that although MFS is equally prevalent in men and women, men are at a higher risk of aortic complications than non-pregnant women. Nevertheless, there is no experimental evidence to support this hypothesis. The aim of this study was to explore whether there are regional and sex differences in the thoracic aorta function of mice heterozygous for the fibrillin 1 ( Fbn1 ) allele encoding a missense mutation ( Fbn1 C1039G/+ ), the most common class of mutation in MFS. Ascending and descending thoracic aorta reactivity was evaluated by wire myography. Ascending aorta mRNA and protein levels, and elastic fiber integrity were assessed by qRT-PCR, Western blotting, and Verhoeff-Van Gieson histological staining, respectively. MFS differently altered reactivity in the ascending and descending thoracic aorta by either increasing or decreasing phenylephrine contractions, respectively. When mice were separated by sex, contractions to phenylephrine increased progressively from 3 to 6 months of age in MFS ascending aortas of males, whereas contractions in females were unchanged. Endothelium-dependent relaxation was unaltered in the MFS ascending aorta of either sex; an effect related to augmented endothelium-dependent hyperpolarization-type dilations. In MFS males, the non-selective cyclooxygenase (COX) inhibitor indomethacin prevented the MFS-induced enhancement of phenylephrine contractions linked to increased COX-2 expression. In MFS mice of both sexes, the non-selective nitric oxide synthase inhibitor L-NAME revealed negative feedback of nitric oxide on phenylephrine contractions, which was associated with upregulation of eNOS in females. Finally, MFS ascending aortas showed a greater number of elastic fiber breaks than the wild-types, and males exhibited more breaks than females. These results show regional and sex differences in Fbn1 C1039G/+ mice thoracic aorta contractility and aortic media injuries. The presence of more pronounced aortic alterations in male mice provides experimental evidence to support that male MFS patients are at increased risk of suffering aortic complications.

Differences in the Thoracic Aorta by Region and Sex in a Murine Model of Marfan Syndrome

PubMed Central

Jiménez-Altayó, Francesc; Siegert, Anna-Maria; Bonorino, Fabio; Meirelles, Thayna; Barberà, Laura; Dantas, Ana P.; Vila, Elisabet; Egea, Gustavo

2017-01-01

Marfan syndrome (MFS) is a hereditary disorder of the connective tissue that causes life-threatening aortic aneurysm, which initiates at the aortic root and can progress into the ascending portion. However, analysis of ascending aorta reactivity in animal models of MFS has remained elusive. Epidemiologic evidence suggests that although MFS is equally prevalent in men and women, men are at a higher risk of aortic complications than non-pregnant women. Nevertheless, there is no experimental evidence to support this hypothesis. The aim of this study was to explore whether there are regional and sex differences in the thoracic aorta function of mice heterozygous for the fibrillin 1 (Fbn1) allele encoding a missense mutation (Fbn1C1039G/+), the most common class of mutation in MFS. Ascending and descending thoracic aorta reactivity was evaluated by wire myography. Ascending aorta mRNA and protein levels, and elastic fiber integrity were assessed by qRT-PCR, Western blotting, and Verhoeff-Van Gieson histological staining, respectively. MFS differently altered reactivity in the ascending and descending thoracic aorta by either increasing or decreasing phenylephrine contractions, respectively. When mice were separated by sex, contractions to phenylephrine increased progressively from 3 to 6 months of age in MFS ascending aortas of males, whereas contractions in females were unchanged. Endothelium-dependent relaxation was unaltered in the MFS ascending aorta of either sex; an effect related to augmented endothelium-dependent hyperpolarization-type dilations. In MFS males, the non-selective cyclooxygenase (COX) inhibitor indomethacin prevented the MFS-induced enhancement of phenylephrine contractions linked to increased COX-2 expression. In MFS mice of both sexes, the non-selective nitric oxide synthase inhibitor L-NAME revealed negative feedback of nitric oxide on phenylephrine contractions, which was associated with upregulation of eNOS in females. Finally, MFS ascending aortas showed a greater number of elastic fiber breaks than the wild-types, and males exhibited more breaks than females. These results show regional and sex differences in Fbn1C1039G/+ mice thoracic aorta contractility and aortic media injuries. The presence of more pronounced aortic alterations in male mice provides experimental evidence to support that male MFS patients are at increased risk of suffering aortic complications. PMID:29187826

Effectiveness of Total Contact Orthosis for Plantar Pressure Redistribution in Neuropathic Diabetic Patients During Different Walking Activities.

PubMed

Nouman, Muhammad; Leelasamran, Wipawan; Chatpun, Surapong

2017-08-01

Using a total contact orthosis (TCO) is an effective method to offload in diabetic patients with foot neuropathy. However, the redistribution of peak plantar pressure is mostly observed during level walking, which may differ from other walking activities. The aim of this study was to investigate the plantar pressure from 4 regions of the foot during different walking activities (level walking, ramp ascending, ramp descending, stair ascending, and stair descending) in neuropathic diabetic patients with and without a TCO. Sixteen neuropathic diabetic patients aged 40 to 60 years with calluses and hallux valgus were included in this study and were provided with TCOs made up of multifoam, Plastazote, and microcellular rubber. The plantar pressure and contact area with the TCO and without the TCO were recorded using the Pedar X system during different walking activities. A significant reduction of plantar pressure during different walking activities at the toes and forefoot regions was observed while walking with the TCO compared with walking without the TCO (control condition). Plantar pressure increased at the midfoot region when walking with the TCO, and no significant difference was observed at the hindfoot region between the control and TCO conditions. Furthermore, maximum contact area was observed during level walking with the TCO compared with other walking activities. The TCO significantly reduced and redistributed the peak plantar pressure from the sites where the ulceration rate is higher at the toes and forefoot compared with the other regions of the foot. Therapeutic level II, lesser quality randomized controlled trial.

Diverticular colitis of the ascending colon preceding the onset of ulcerative colitis.

PubMed

Maeshiro, Tatsuji; Hokama, Akira; Kinjo, Tetsu; Fujita, Jiro

2014-06-30

We present a case of diverticular colitis of the ascending colon preceding the onset of ulcerative colitis. A 58-year-old man presented with positive faecal occult blood test. Colonoscopy disclosed diverticular colitis of the ascending colon. After a year's follow-up, typical ulcerative colitis developed and diverticular colitis improved. Diverticular colitis is a newly established disorder of chronic segmental mucosal inflammation affected by diverticular disease. There is increasing recognition of such cases with diverticular colitis preceding ulcerative colitis. There may be a possible pathogenic relationship between the two diseases. 2014 BMJ Publishing Group Ltd.

The use of a stentless porcine bioprosthesis to repair an ascending aortic aneurysm in combination with aortic valve regurgitation.

PubMed Central

Akpinar, B; Sanisoğlu, I; Konuralp, C; Akay, H; Güden, M; Sönmez, B

1999-01-01

Over the years, many surgical methods have evolved for the treatment of ascending aortic aneurysm in combination with aortic valve regurgitation; however, precise guidelines for optimal surgical techniques for varying presentations have not been defined. We describe the use of a stentless porcine bioprosthesis (Medtronic Freestyle) in a patient with an ascending aortic aneurysm and aortic regurgitation. We used the complete root replacement method, and anastomosed a Dacron graft (Hemashield) between the bioprosthetic valve and the native aorta to replace the distal part of the aneurysm. Images PMID:10524742

Activation of anorexigenic pro-opiomelanocortin neurones during refeeding is independent of vagal and brainstem inputs.

PubMed

Fekete, C; Zséli, G; Singru, P S; Kádár, A; Wittmann, G; Füzesi, T; El-Bermani, W; Lechan, R M

2012-11-01

After fasting, satiety is observed within 2 h after reintroducing food, accompanied by activation of anorexigenic, pro-opiomelanocortin (POMC)-synthesising neurones in the arcuate nucleus (ARC), indicative of the critical role that α-melanocyte-stimulating hormone has in the regulation of meal size during refeeding. To determine whether refeeding-induced activation of POMC neurones in the arcuate is dependent upon the vagus nerve and/or ascending brainstem pathways, bilateral subdiaphragmatic vagotomy or transection of the afferent brainstem input to one side of the ARC was performed. One day after vagotomy or 2 weeks after brain surgery, animals were fasted and then refed for 2 h. Sections containing the ARC from vagotomised animals or animals with effective transection were immunostained for c-Fos and POMC to detect refeeding-induced activation of POMC neurones. Quantitative analyses of double-labelled preparations demonstrated that sham-operated and vagotomised animals markedly increased the number of c-Fos-immunoreactive (-IR) POMC neurones with refeeding. Furthermore, transection of the ascending brainstem pathway had no effect on diminishing c-Fos-immunoreactivity in POMC neurones on either side of the ARC, although it did diminish activation in a separate, subpopulation of neurones in the dorsomedial posterior ARC (dmpARC) on the transected side. We conclude that inputs mediated via the vagus nerve and/or arising from the brainstem do not have a primary role in refeeding-induced activation of POMC neurones in the ARC, and propose that these neurones may be activated solely by direct effects of circulating hormones/metabolites during refeeding. Activation of the dmpARC by refeeding indicates a previously unrecognised role for these neurones in appetite regulation in the rat. © 2012 The Authors. Journal of Neuroendocrinology © 2012 British Society for Neuroendocrinology.

Coronary Sinus Activation and ECG Characteristics of Roof-Dependent Left Atrial Flutter After Pulmonary Vein Isolation.

PubMed

Casado Arroyo, Ruben; Laţcu, Decebal Gabriel; Maeda, Shingo; Kubala, Maciej; Santangeli, Pasquale; Garcia, Fermin Carlos; Enache, Bogdan; Eljamili, Mohammed; Hayashi, Tatsuya; Zado, Erica S; Saoudi, Nadir; Marchlinski, Francis E

2018-06-01

The electrocardiographic and intracardiac activation features of left atrial roof-dependent macroreentrant flutter have been incompletely characterized. Patients post-pulmonary vein (PV) isolation with roof-dependent atrial flutter based on activation and entrainment mapping were included. ECG and coronary sinus activation were compared with mitral annular (MA) flutter. The roof-dependent left atrial flutter circled the right PVs in 32 of 33 cases. Two forms of roof flutters were identified, posteroanterior, ascendant on posterior wall and descendant on anterior wall (n=24); and anteroposterior, ascendant on the anterior wall and descendent on the posterior wall (n=9). Both forms had positive large amplitude P waves in V 1 through V 2 with decreasing amplitude in V 3 through V 6 . Posteroanterior roof flutters had positive P wave in the inferior and negative P wave in leads I and aVL similar to counterclockwise MA flutter, but coronary sinus activation was simultaneous for roof and proximal to distal for counterclockwise. Anteroposterior roof flutters were similar to clockwise MA flutter with negative P in inferior leads and transition to flat or negative P in V 3 through V 6 . Coronary sinus activation time ≤39 ms identified roof versus MA flutter (sensitivity: 100% and specificity: 97%). Roof-dependent flutter around right PVs is more common than around left PVs. The ECG pattern for roof-dependent flutter around right PVs is similar to MA flutter with frontal plane axis dictated by septal activation. Roof-dependent flutter can be distinguished from MA flutter by more simultaneous rather than sequential coronary sinus activation. © 2018 American Heart Association, Inc.

Sodium Chloride and Water Transport in the Medullary Thick Ascending Limb of Henle. EVIDENCE FOR ACTIVE CHLORIDE TRANSPORT

PubMed Central

Rocha, Antonino S.; Kokko, Juha P.

1973-01-01

Transport of NaCl and water was examined in the rabbit medullary thick ascending limb of Henle (ALH) by perfusing isolated segments of these nephrons in vitro. Osmotic water permeability was evaluated by perfusing tubules against imposed osmotic gradients. In these experiments the net transport of fluid remained at zero when segments of thick ALH were perfused with isotonic ultrafiltrate in a bath of rabbit serum in which the serum osmolality was increased by the addition of either 239±8 mosmol/liter of raffinose or 232±17 mosmol of NaCl indicating that the thick ascending limb of Henle is impermeant to osmotic flow of water. When these tubules were perfused at slow rates with isosmolal ultrafiltrate of same rabbit serum as used for the bath, the effluent osmolality was consistently lowered to concentrations less than the perfusate and the bath. That this decrease in collected fluid osmolality represented salt transport was demonstrated in a separate set of experiments in which it was shown that the sodium and chloride concentrations decreased to 0.79±0.02 and 0.77±0.02 respectively when compared with the perfusion fluid concentrations. In each instance the simultaneously determined transtubular potential difference (PD) revealed the lumen to be positive with the magnitude dependent on the perfusion rate. At flow rates above 2 nl·min-1, the mean transtubular PD was stable and equal to 6.70±0.34 mv. At stop-flow conditions this PD became more positive. Ouabain and cooling reversibly decreased the magnitude of this PD. The transtubular PD remained positive, 3.3±0.2 mV, when complete substitution of Na by choline was carried out in both the perfusion fluid and the bathing media. These results are interpreted to indicate that the active transport process is primarily an electrogenic chloride mechanism. The isotopic permeability coefficient for Na was 6.27±0.38 × 10-5 cm·s-1 indicating that the thick ALH is approximately as permeable to Na as the proximal convoluted tubule. The chloride permeability coefficient for the thick ALH was 1.06±0.12 × 10-5 cm·s-1 which is significantly less than the chloride permeability of the proximal tubule. These data demonstrate that the medullary thick ascending limb of Henle is water impermeable while having the capacity for active outward solute transport as a consequence of an electrogenic chloride pump. The combination of these characteristics allows this segment to generate a dilute tubular fluid and participate as the principal energy source for the overall operation of the countercurrent multiplication system. Images PMID:4685086

Sensing of blood pressure increase by transient receptor potential vanilloid 1 receptors on baroreceptors.

PubMed

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N; Pan, Hui-Lin

2009-12-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis.

Sensing of Blood Pressure Increase by Transient Receptor Potential Vanilloid 1 Receptors on Baroreceptors

PubMed Central

Sun, Hao; Li, De-Pei; Chen, Shao-Rui; Hittelman, Walter N.

2009-01-01

The arterial baroreceptor is critically involved in the autonomic regulation of homoeostasis. The transient receptor potential vanilloid 1 (TRPV1) receptor is expressed on both somatic and visceral sensory neurons. Here, we examined the TRPV1 innervation of baroreceptive pathways and its functional significance in the baroreflex. Resiniferatoxin (RTX), an ultrapotent analog of capsaicin, was used to ablate TRPV1-expressing afferent neurons and fibers in adult rats. Immunofluorescence labeling revealed that TRPV1 immunoreactivity was present on nerve fibers and terminals in the adventitia of the ascending aorta and aortic arch, the nodose ganglion neurons, and afferent fibers in the solitary tract of the brainstem. RTX treatment eliminated TRPV1 immunoreactivities in the aorta, nodose ganglion, and solitary tract. Renal sympathetic nerve activity, blood pressure, and heart rate were recorded in anesthetized rats. The baroreflex was triggered by lowering and raising blood pressure through intravenous infusion of sodium nitroprusside and phenylephrine, respectively. Inhibition of sympathetic nerve activity and heart rate by the phenylephrine-induced increase in blood pressure was largely impaired in RTX-treated rats. The maximum gain of the baroreflex function was significantly lower in RTX-treated than vehicle-treated rats. Furthermore, blocking of TRPV1 receptors significantly blunted the baroreflex and decreased the maximum gain of baroreflex function in the high blood pressure range. Our findings provide important new information that TRPV1 is expressed along the entire baroreceptive afferent pathway. TRPV1 receptors expressed on baroreceptive nerve endings can function as mechanoreceptors to detect the increase in blood pressure and maintain the homoeostasis. PMID:19726694

Initial medical management in acute type A aortic dissection patients with a thrombosed false lumen in the ascending aorta combining intramural hematoma and retrograde dissection from the descending to the ascending aorta.

PubMed

Sadamatsu, Kenji; Takase, Susumu; Sagara, Shuichiro; Ohe, Kensuke; Nishi, Jun-Ichiro; Tashiro, Hideki; Kosuga, Tomokazu; Yasunaga, Hiroshi

2018-05-01

The feasibility of medical management for select patients with acute type A aortic dissection has been reported from a few institutions. In this study, we retrospectively investigated the safety and feasibility of our conservative approach for patients with type A aortic dissection in daily practice. From January 2013 to December 2017, 131 consecutive patients were admitted to our institution for acute aortic dissection, including 58 patients of type A. Initial medical management was attempted in select patients who were clinically stable and had a thrombosed false lumen of the ascending aorta without ulcer-like projections in the ascending aorta. Except for nine patients contraindicated for surgery, urgent surgery was performed in 26 patients (SRG group), while 23 patients (MED group) were treated with the initial medical management. The maximum diameter of the ascending aorta was significantly larger in the SRG group than in the MED group. In the MED group, the heart rate and blood pressures were well-controlled at admission to the intensive-care unit, and the systolic blood pressure was further reduced at 24 h after. The in-hospital mortality rates of the MED and SRG groups were 0% and 15%, respectively. During the follow-up period, the survival rate was significantly higher in the MED group than in the SRG group, and the aortic event-free survival at one year was 80%. The initial medical management for select patients with a thrombosed false lumen in the ascending aorta was a safe and feasible strategy in real-world practice.

Ascending aortic curvature as an independent risk factor for type A dissection, and ascending aortic aneurysm formation: a mathematical model.

PubMed

Poullis, Michael P; Warwick, Richard; Oo, Aung; Poole, Robert J

2008-06-01

To develop a mathematical model to demonstrate that ascending aortic curvature is an independent risk factor for type A dissections, in addition to hypertension, bicuspid aortic valve, aneurysm of ascending aorta, and intrinsic aortic tissue abnormalities, like Marfan's syndrome. A steady state one-dimensional flow analysis was performed, utilising Newton's third law of motion. Five different clinical scenarios were evaluated: (1) effect of aortic curvature; (2) effect of beta-blockers, (3) effect of patient size, (4) forces on a Marfan's aorta, and (5) site of entry flap in aortic dissection. Aortic curvature increases the forces exerted on the ascending aorta by a factor of over 10-fold. Aortic curvature can cause patients with a systolic blood pressure of 8 0mmHg to have greater forces exerted on their aorta despite smaller diameters and lower cardiac outputs, than patients with systolic blood pressures of 120 mmHg. In normal diameter aortas, beta-blockers have minimal effect compared with aortic curvature. Aortic curvature may help to explain why normal diameter aortas can dissect, and also that the point of the entry tear may be potentially predictable. Aortic curvature has major effects on the forces exerted on the aorta in patients with Marfan's syndrome. Aortic curvature is relatively more important that aortic diameter, blood pressure, cardiac output, beta-blocker use, and patient size with regard to the force acting on the aortic wall. This may explain why some patients with normal diameter ascending aortas with or without Marfan's syndrome develop type A dissections and aneurysms. Aortic curvature may also help to explain the site of entry tear in acute type A dissection. Further clinical study is needed to validate this study's finding.

Synchronized epiaortic two-dimensional and color Doppler echocardiographic guidance enables routine ascending aortic cannulation in type A acute aortic dissection.

PubMed

Inoue, Yoshito; Takahashi, Ryuichi; Ueda, Toshihiko; Yozu, Ryohei

2011-02-01

Preference for arterial inflow during surgery for type A acute aortic dissection remains controversial. Antegrade central perfusion prevents malperfusion and retrograde embolism, and the ascending aorta provides arterial access for rapid establishment of systemic perfusion, especially if there is hemodynamic instability. It has not been used routinely, however, because of the disruption caused to the aorta. We evaluated the safety and efficacy of routine cannulation of the dissected aorta for the repair of type A dissection. Surgical results were analyzed for 83 consecutive patients with type A acute aortic dissection between 2002 and 2009. They were treated surgically by prosthetic graft replacement under hypothermic circulatory arrest. The ascending aorta was routinely cannulated using the Seldinger technique with epiaortic echocardiographic guidance; antegrade systemic perfusion was evaluated by color Doppler ultrasound. Systemic antegrade perfusion via the dissected ascending aorta was performed safely in all cases. There was no malperfusion or thromboembolism as a result of ascending aortic cannulation. Epiaortic 2-dimensional and color Doppler imaging provided real-time monitoring adequate for the placement and for proper systemic perfusion. There were 5 in-hospital deaths (5/83=6.0%) and 8 strokes (preoperative 6/83=7.2%, postoperative 2/83=2.4%). A total of 78 patients (78/83=94%) were discharged and have been followed up without major adverse cardiac events for a mean duration of 31.8 months. Ascending aortic cannulation is a simple and safe technique that provides a rapid and reliable route of antegrade central systemic perfusion in type A aortic dissection. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

Roof Plate-Derived Radial Glial-like Cells Support Developmental Growth of Rapidly Adapting Mechanoreceptor Ascending Axons.

PubMed

Kridsada, Kim; Niu, Jingwen; Haldipur, Parthiv; Wang, Zhiping; Ding, Long; Li, Jian J; Lindgren, Anne G; Herrera, Eloisa; Thomas, Gareth M; Chizhikov, Victor V; Millen, Kathleen J; Luo, Wenqin

2018-06-05

Spinal cord longitudinal axons comprise some of the longest axons in our body. However, mechanisms that drive this extra long-distance axonal growth are largely unclear. We found that ascending axons of rapidly adapting (RA) mechanoreceptors closely abut a previously undescribed population of roof plate-derived radial glial-like cells (RGLCs) in the spinal cord dorsal column, which form a network of processes enriched with growth-promoting factors. In dreher mutant mice that lack RGLCs, the lengths of ascending RA mechanoreceptor axon branches are specifically reduced, whereas their descending and collateral branches, and other dorsal column and sensory pathways, are largely unaffected. Because the number and intrinsic growth ability of RA mechanoreceptors are normal in dreher mice, our data suggest that RGLCs provide critical non-cell autonomous growth support for the ascending axons of RA mechanoreceptors. Together, our work identifies a developmental mechanism specifically required for long-range spinal cord longitudinal axons. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Development and Implementation for Calculation Model of Measuring Co-Seismic Deformation Field by Using Ascending and Descending Orbit SAR Data

NASA Astrophysics Data System (ADS)

Xue, Tengfei; Chang, Zhanqiang; Zhang, Jingfa

2016-08-01

Interferometry Synthetic Aperture Radar (InSAR)can only measure one component of the surface deformation in the satellite's line of sight (LOS) instead of that in vertical and horizontal directions, i.e. LOS Amphibious. In view of this problem, we analyzed and summarized some methods that can measure the three-dimensional deformation of ground surface by using D-InSAR, developed the calculation model of measuring the three-dimensional co-seismic deformation filed by using the ascending and descending orbit SAR data. The Formula of left-looking (both ascending and descending orbit data), right-looking (both ascending and descending orbit data) and general expression were proposed. The model was applied on L'Aquila earthquake, and the results reveal that the earthquake has caused displacement in both vertical and horizontal directions, and the earthquake made the area down lift 16.8cm along the vertical direction. The characters of the surface reflected by the results are very consistent with the geological exploration.

Epiaortic fat pad area: A novel index for the dimensions of the ascending aorta.

PubMed

Toufan, Mehrnoush; Pourafkari, Leili; Boudagh, Shabnam; Nader, Nader D

2016-06-01

We sought to investigate the possible association between the area of the epiaortic fat pad (EAFP) and dimensions of the ascending aorta. A total of 193 individuals underwent transthoracic echocardiography (TTE) prospectively. The area of the EAFP was traced anterior to the aortic root and correlated with the diameter of the aorta. The mean area of the EAFP was 5.16 ± 2.28 cm(2) Absolute and indexed dimensions of the ascending aorta had a significant correlation with the area of the EAFP (p <0.001 for all). In a multivariate linear regression model, age >65 (p <0.001), body mass index >30 kg/m(2) (p = 0.02) and a history of hyperlipidemia (p = 0.003) were identified as independent predictors of the area for EAFP. In conclusion, both the absolute and indexed diameters of the ascending aorta at the different segments that directly come into contact with the EAFP linearly correlate with the area of the EAFP measured by TTE. © The Author(s) 2016.

Effect of Fatigue Upon Performance and Electromyographic Activity in 6-RM Bench Press

PubMed Central

van den Tillaar, Roland; Saeterbakken, Atle

2014-01-01

The aim of this study was to examine the effect of fatigue during one set of 6-RM bench pressing upon the muscle patterning and performance. Fourteen resistance-trained males (age 22.5±2.0 years, stature 1.82±0.07 m, body mass 82.0±7.8 kg) conducted a 6-RM bench press protocol. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were measured in each repetition during the 6-RM bench press. Total lifting time increased and the velocity in the ascending movement decreased (p≤0.001). However, the kinematics in the descending phase deferred: the time decreased and velocity increased during the 6-RM (p≤0.001). Generally, muscles increased their EMG amplitude during the six repetitions in the ascending movement, while only three of the seven measured muscles showed an increase over the six repetitions in the descending part in 6-RM bench pressing. It was concluded that the bench pressing performance decreased (lower barbell velocities and longer lifting times) with increasing fatigue in the 6-RM execution. Furthermore EMG increased in the prime movers and the trunk stabilizers (abdominal and spine), while the antagonist muscle (biceps) activity was not affected by fatigue during the lifting phase in a single set of 6-RM bench pressing PMID:25031673

Effect of Fatigue Upon Performance and Electromyographic Activity in 6-RM Bench Press.

PubMed

van den Tillaar, Roland; Saeterbakken, Atle

2014-03-27

The aim of this study was to examine the effect of fatigue during one set of 6-RM bench pressing upon the muscle patterning and performance. Fourteen resistance-trained males (age 22.5±2.0 years, stature 1.82±0.07 m, body mass 82.0±7.8 kg) conducted a 6-RM bench press protocol. Barbell kinematics and EMG activity of pectoralis major, deltoid anterior, biceps brachii, triceps brachii, rectus abdominis, oblique external and erector spinae were measured in each repetition during the 6-RM bench press. Total lifting time increased and the velocity in the ascending movement decreased (p≤0.001). However, the kinematics in the descending phase deferred: the time decreased and velocity increased during the 6-RM (p≤0.001). Generally, muscles increased their EMG amplitude during the six repetitions in the ascending movement, while only three of the seven measured muscles showed an increase over the six repetitions in the descending part in 6-RM bench pressing. It was concluded that the bench pressing performance decreased (lower barbell velocities and longer lifting times) with increasing fatigue in the 6-RM execution. Furthermore EMG increased in the prime movers and the trunk stabilizers (abdominal and spine), while the antagonist muscle (biceps) activity was not affected by fatigue during the lifting phase in a single set of 6-RM bench pressing.

[Pain information pathways from the periphery to the cerebral cortex].

PubMed

Kuroda, Ryotaro; Kawabata, Atsufumi

2003-07-01

A recent PET study revealed that the first and second somatosensory cortices (SI, SII), and the anterior cingulate cortex are activated by painful peripheral stimulation in humans. It has become clear that painful signals (nociceptive information) evoked at the periphery are transmitted via various circuits to the multiple cerebral cortices where pain signals are processed and perceived. Human or clinical pain is not merely a modality of somatic sensation, but associated with the affect that accompanies sensation. Consequently, pain has a somatosensory-discriminative aspect and an affective-cognitive aspect that are processed in different but correlated brain structures in the ascending circuits. Considering the physiologic characteristics and fiber connections, the SI and SII cortices appear to be involved in somatosensory-discriminative pain, and the anterior cingulate cortex (area 24) in the affective-cognitive aspect of pain. This paper deals with the ascending pain pathways from the periphery to these cortices and their interconnections. Our recent findings on the protease-activated receptors 1 and 2 (PAR-1, and -2), which are confirmed to exist in the dorsal root ganglion cells, are also described. Activation of PAR-2 during inflammation or tissue injury at the periphery is pronociceptive, while PAR-1 appears to be antinociceptive. Based on the these findings, PAR-1 and PAR-2 are attracting interest as target molecules for new drug development.

Fabrication of thin ZnO films with wide-range tuned optical properties by reactive magnetron sputtering

NASA Astrophysics Data System (ADS)

Davydova, A.; Tselikov, G.; Dilone, D.; Rao, K. V.; Kabashin, A. V.; Belova, L.

2018-02-01

We report the manufacturing of thin zinc oxide films by reactive magnetron sputtering at room temperature, and examine their structural and optical properties. We show that the partial oxygen pressure in DC mode can have dramatic effect on absorption and refractive index (RI) of the films in a broad spectral range. In particular, the change of the oxygen pressure from 7% to 5% can lead to either conventional crystalline ZnO films having low absorption and characteristic descending dependence of RI from 2.4-2.7 RIU in the visible to 1.8-2 RIU in the near-infrared (1600 nm) range, or to untypical films, composed of ZnO nano-crystals embedded into amorphous matrix, exhibiting unexpectedly high absorption in the visible-infrared region and ascending dependence of RI with values varying from 1.5 RIU in the visible to 4 RIU in the IR (1600 nm), respectively. Untypical optical characteristics in the second case are explained by defects in ZnO structure arising due to under-oxidation of ZnO crystals. We also show that the observed defect-related film structure remains stable even after annealing of films under relatively high temperatures (30 min under 450 °C). We assume that both types of films can be of importance for photovoltaic (as contact or active layers, respectively), as well as for chemical or biological sensing, optoelectronics etc.

A Broad Bank Lidar for Precise Atmospheric CO2 Column Absorption Measurement from Space

NASA Technical Reports Server (NTRS)

Georgieva, E. M.; Heaps, W. S.; Huang, W.

2010-01-01

Accurate global measurement of carbon dioxide column with the aim of discovering and quantifying unknown sources and sinks has been a high priority for the last decade. In order to uncover the "missing sink" that is responsible for the large discrepancies in the budget the critical precision for a measurement from space needs to be on the order of 1 ppm. To better understand the CO2 budget and to evaluate its impact on global warming the National Research Council (NRC) in its recent decadal survey report (NACP) to NASA recommended a laser based total CO2 mapping mission in the near future. That's the goal of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission - to significantly enhance the understanding of the role of CO2 in the global carbon cycle. Our current goal is to develop an ultra precise, inexpensive new lidar system for column measurements of CO2 changes in the lower atmosphere that uses a Fabry-Perot interferometer based system as the detector portion of the instrument and replaces the narrow band laser commonly used in lidars with a high power broadband source. This approach reduces the number of individual lasers used in the system and considerably reduces the risk of failure. It also tremendously reduces the requirement for wavelength stability in the source putting this responsibility instead on the Fabry- Perot subsystem.

Mission Simulation of Space Lidar Measurements for Seasonal and Regional CO2 Variations

NASA Technical Reports Server (NTRS)

Kawa, Stephan; Collatz, G. J.; Mao, J.; Abshire, J. B.; Sun, X.; Weaver, C. J.

2010-01-01

Results of mission simulation studies are presented for a laser-based atmospheric [82 sounder. The simulations are based on real-time carbon cycle process modeling and data analysis. The mission concept corresponds to the Active Sensing of [82 over Nights, Days, and Seasons (ASCENDS) recommended by the US National Academy of Sciences Decadal Survey of Earth Science and Applications from Space. One prerequisite for meaningful quantitative sensor evaluation is realistic CO2 process modeling across a wide range of scales, i.e., does the model have representative spatial and temporal gradients? Examples of model comparison with data will be shown. Another requirement is a relatively complete description of the atmospheric and surface state, which we have obtained from meteorological data assimilation and satellite measurements from MODIS and [ALIPS0. We use radiative transfer model calculations, an instrument model with representative errors ' and a simple retrieval approach to complete the cycle from "nature" run to "pseudo-data" CO2, Several mission and instrument configuration options are examined/ and the sensitivity to key design variables is shown. We use the simulation framework to demonstrate that within reasonable technological assumptions for the system performance, relatively high measurement precision can be obtained, but errors depend strongly on environmental conditions as well as instrument specifications. Examples are also shown of how the resulting pseudo - measurements might be used to address key carbon cycle science questions.

Systolic ventricular filling.

PubMed

Torrent-Guasp, Francisco; Kocica, Mladen J; Corno, Antonio; Komeda, Masashi; Cox, James; Flotats, A; Ballester-Rodes, Manel; Carreras-Costa, Francesc

2004-03-01

The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles involved in this action. This contraction occurs during the last part of classical systole and the first part of diastole. Therefore, the most important part of ventricular diastole (i.e. the rapid filling phase), in which it receives >70% of the stroke volume, belongs to the active muscular contraction of the ascendent segment. We hope that these facts will give rise to new understanding of the principal mechanisms involved in normal and abnormal diastolic heart function.

Angiotensin II stimulates basolateral 50-pS K channels in the thick ascending limb.

PubMed

Wang, Mingxiao; Luan, Haiyan; Wu, Peng; Fan, Lili; Wang, Lijun; Duan, Xinpeng; Zhang, Dandan; Wang, Wen-Hui; Gu, Ruimin

2014-03-01

We used the patch-clamp technique to examine the effect of angiotensin II (ANG II) on the basolateral K channels in the thick ascending limb (TAL) of the rat kidney. Application of ANG II increased the channel activity and the current amplitude of the basolateral 50-pS K channel. The stimulatory effect of ANG II on the K channels was completely abolished by losartan, an inhibitor of type 1 angiotensin receptor (AT1R), but not by PD123319, an AT2R antagonist. Moreover, inhibition of phospholipase C (PLC) and protein kinase C (PKC) also abrogated the stimulatory effect of ANG II on the basolateral K channels in the TAL. This suggests that the stimulatory effect of ANG II on the K channels was induced by activating PLC and PKC pathways. Western blotting demonstrated that ANG II increased the phosphorylation of c-Src at tyrosine residue 416, an indication of c-Src activation. This effect was mimicked by PKC stimulator but abolished by calphostin C. Moreover, inhibition of NADPH oxidase (NOX) also blocked the effect of ANG II on c-Src tyrosine phosphorylation. The role of Src-family protein tyrosine kinase (SFK) in mediating the effect of ANG II on the basolateral K channel was further suggested by the experiments in which inhibition of SFK abrogated the stimulatory effect of ANG II on the basolateral 50-pS K channel. We conclude that ANG II increases basolateral 50-pS K channel activity via AT1R and that activation of AT1R stimulates SFK by a PLC-PKC-NOX-dependent mechanism.

[Graft Pseudoaneurysm after Ascending to Abdominal Aorta Bypass for Atypical Coarctation Due to Aortitis Syndrome;Report of a Case].

PubMed

Yada, Masashi; Yamanaka, Kazuo; Miwa, Senri; Hirose, Keiichi; Sakaguchi, Hisashi; Yoshida, Yukiyo; Onga, Youhei; Tara, Yuichi

2017-05-01

We present a case of a 44-year-old woman, with pseudoaneurysm formation at the middle of the prosthetic graft, 60 mm in diameter. She had been diagnosed with atypical coarctation due to aortitis 27 years before, and had undergone a bypass operation with 14 mm-diameter Cooley double velour graft from the ascending aorta to the abdominal aorta. This time, endovascular aortic repair was performed to prevent rupture of the pseudoaneurysm. Though a knitted Dacron graft has a risk of psuedaneurysm formation long patency could be obtained when used in ascending aorta-abdominal aorta bypass.

Monozygotic twins with Marfan's syndrome and ascending aortic aneurysm.

PubMed

Redruello, Héctor Jorge; Cianciulli, Tomas Francisco; Rostello, Eduardo Fernandez; Recalde, Barbara; Lax, Jorge Alberto; Picone, Victorio Próspero; Belforte, Sandro Mario; Prezioso, Horacio Alberto

2007-08-01

Marfan's syndrome is a hereditary connective tissue disease, in which cardiovascular abnormalities (especially aortic root dilatation) are the most important cause of morbidity and mortality. In this report, we describe two 24-year-old twins, with a history of surgery for lens subluxation and severe cardiovascular manifestations secondary to Marfan's syndrome. One of the twins suffered a type A aortic dissection, which required replacement of the ascending aorta, and the other twin had an aneurysmal dilatation of the ascending aorta (46mm) and was prescribed medical treatment with atenolol and periodic controls to detect the presence of a critical diameter (50mm) that would indicate the need for prophylactic surgery.

[Re-operation for Saccular Aneurysm after Ascending Aortic Replacement with Homograft;Report of a Case].

PubMed

Ikeda, Masahiro; Asakura, Toshihisa; Uwabe, Kazuhiko; Morita, Kozo; Iguchi, Atsushi; Niinami, Hiroshi

2017-09-01

A 62-years-old female had undergone ascending aortic replacement with homograft for graft infection and mediastinitis after initial replacement of ascending aorta due to acute type A dissection. Ten years after homograft replacement, follow up computed tomography showed acute growing saccular aneurysm of the homograft without infectious symptoms. We urgently performed Bentall procedure and hemiarch replacement successfully. Pathological diagnosis was true aneurysm of the homograft. She was discharged from hospital without any complication and has been quite uneventful 7 years after surgery. True aneurysm of the homograft is very rare and our case is the 1st report of successful reoperation.

Aortic annulus and ascending aorta: comparison of preoperative and periooperative measurement in patients with aortic stenosis.

PubMed

Smíd, Michal; Ferda, Jirí; Baxa, Jan; Cech, Jakub; Hájek, Tomás; Kreuzberg, Boris; Rokyta, Richard

2010-04-01

Precise determination of the aortic annulus size constitutes an integral part of the preoperative evaluation prior to aortic valve replacement. It enables the estimation of the size of prosthesis to be implanted. Knowledge of the size of the ascending aorta is required in the preoperative analysis and monitoring of its dilation enables the precise timing of the operation. Our goal was to compare the precision of measurement of the aortic annulus and ascending aorta using magnetic resonance (MR), multidetector-row computed tomography (MDCT), transthoracic echocardiography (TTE), and transoesophageal echocardiography (TEE) in patients with degenerative aortic stenosis. A total of 15 patients scheduled to have aortic valve replacement were enrolled into this prospective study. TTE was performed in all patients and was supplemented with TEE, CT and MR in the majority of patients. The values obtained were compared with perioperative measurements. For the measurement of aortic annulus, MR was found to be the most precise technique, followed by MDCT, TTE, and TEE. For the measurement of ascending aorta, MR again was found to be the most precise technique, followed by MDCT, TEE, and TTE. In our study, magnetic resonance was found to be the most precise technique for the measurement of aortic annulus and ascending aorta in patients with severe degenerative aortic stenosis. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Effects of ascending and descending climbers on space elevator cable dynamics

NASA Astrophysics Data System (ADS)

Ishikawa, Yoji; Otsuka, Kiyotoshi; Yamagiwa, Yoshiki; Doi, Hinata

2018-04-01

Based on a mass-point model, the cable dynamics of a space elevator during a climber's travel motion are examined. The cable response during a single operation of one ascending or descending climber is analyzed first, and then, based on the results, the cable dynamics for simultaneous operation of an ascending and a descending climber are evaluated. For the single operation, bending is significant when the climber is traveling near the Earth's surface. The cable also inclines with periodic oscillation as a result of a Coriolis force corresponding to the climber velocity. However, simultaneous operation of ascending and descending climbers can suppress the inclination of the cable by almost a factor of ten. In simultaneous operation, compared to single operation, a descending climber has a smaller amplitude of libration angle and less cable bending, while an ascending climber has a smaller amplitude when the climber is traveling at a higher altitude with climber velocities of 200 km/h and 400 km/h. The phase of the oscillation of the overall cable is found to be close to that of the descending climber. Cable bending is suppressed for any examined climber velocity, but the dependency of this suppression of displacement on climber velocity is not found. In summary, simultaneous operation can surely suppress the inclination of the cable via the cancellation of Coriolis forces by the two climbers.

The effect of a probiotic drink with Lactobacillus plantarum 299v on the bacterial composition in faeces and mucosal biopsies of rectum and ascending colon.

PubMed

Goossens, D A M; Jonkers, D M A E; Russel, M G V M; Stobberingh, E E; Stockbrügger, R W

2006-01-15

Studies on probiotics mainly base their results on faecal samples, which may not represent the situation in the mucosa of distal and proximal colon. In a placebo-controlled study, to assess the effect of Lactobacillus plantarum 299v on the bacterial composition of faecal vs. mucosal samples. Twenty-nine patients undergoing colonoscopic examination for polyps consumed a twice-daily drink with or without L. plantarum 299v (10(11) CFU/day) for 2 weeks. Faecal samples were collected before and after consumption. During colonoscopy, biopsies were collected from the ascending colon and rectum. The faecal and mucosal bacterial concentrations and prevalence were determined. L. plantarum 299v significantly increased the concentration of faecal lactic acid bacteria, lactobacilli and clostridia, and was identified in two rectal biopsies but not in the ascending colon biopsies of probiotic-treated subjects. Concentrations and prevalence in ascending colon and rectum biopsies were comparable, but were significantly lower compared with faecal samples. After probiotic consumption, a significant increase in the faecal concentration of lactobacilli was found but concentrations were low in biopsies. The bacterial composition in biopsies of the ascending colon and rectum did not differ based on culture techniques. To further elucidate the modes of action of probiotics, it might be necessary to study differences in colonization with molecular techniques.

Gross anatomy of the intestine and its mesentery in the nutria (Myocastor coypus).

PubMed

Pérez, W; Lima, M; Bielli, A

2008-11-01

The intestines and mesentery of the nutria (Myocastor coypus) have not been fully described. In the present study 30 adult nutrias were studied using gross dissection. The small intestine was divided into the duodenum, jejunum and ileum as usual. The duodenum started at the pylorus with a cranial portion, which dilated forming a duodenal ampulla. The ileum was located within the concavity of the caecum and attached to the coiled caecum by means of the iliocaecal fold. The ascending colon had two ansae, one proximal and one distal. The proximal ansa was fixed to the caecum by the caecocolic fold. The base of the caecum and a short proximal part of the ascending colon belonging to the proximal ansa were attached to the mesoduodenum descendens. The distal ansa of the ascending colon had a proximal part which was sacculated and a distal part which was smooth. The two parts of the distal ansa of the ascending colon were parallel and joined by a flexure of variable localisation. The smooth part of the distal ansa of the ascending colon was attached to the initial portion of the descending colon by a peritoneal fold. The short transverse colon was directly attached to the mesoduodenum and greater omentum. In conclusion, we have described the anatomy of the intestines of the nutria and its mesentery in detail, and provided a nomenclature list adapted to the Nomina Anatomica Veterinaria.

Observations on the macroscopic anatomy of the intestinal tract and its mesenteric folds in the pampas deer (Ozotoceros bezoarticus, Linnaeus 1758).

PubMed

Pérez, W; Clauss, M; Ungerfeld, R

2008-08-01

We described the macroscopic anatomy of the intestines and their peritoneal folds of five adult pampas deer (Ozotoceros bezoarticus), a cervid species considered to ingest a high proportion of grass in its natural diet. The mean (+/-SD) body weight was 17 (+/-2) kg. The small intestine and the caecocolon measured 495 (+/-37) cm and 237 (+/-24) cm in length, respectively, with an average ratio (small intestine:caecocolon) of 1.9 (+/-0.1). The ascending colon had two and a half centripetal gyri, a central flexure and two centrifugal gyri. The spiral ansa, which was similar to an ellipse, was fixed to the whole left face of the mesenterium. Apart from the peritoneal folds described in the Nomina Anatomica Veterinaria, three additional, hitherto not described folds were found: a fold that fixed the caecum to the proximal ansa of the ascending colon, one that joined the terminal part of the proximal ansa to the last centrifugal gyrus of the spiral ansa of the ascending colon, and one that linked the ascending duodenum to the proximal ansa of the ascending colon. When compared with published data from other cervids of different feeding niches, it appears that, among cervids, the ratio of small intestine to the caecocolon length does not reflect the natural diet.

Orexin A affects ascending contraction depending on downstream cholinergic neurons and descending relaxation through independent pathways in mouse jejunum.

PubMed

Satoh, Yuji; Okishio, Yutaka; Azuma, Yasu-Taka; Nakajima, Hidemitsu; Hata, Fumiaki; Takeuchi, Tadayoshi

2006-09-01

The involvement of orexin in neural pathways for peristalsis was examined in mouse jejunal segments. Localized distension of the segments using a small balloon resulted in ascending contraction and descending relaxation. Ascending contraction was abolished by atropine and tetrodotoxin. Desensitization to orexin A (OXA) and SB-334867-A, an orexin-1 receptor antagonist, significantly inhibited ascending contraction. Hexamethonium also produced a significant inhibition. Exogenous administration of either OXA or nicotine induced a transient contraction that was completely inhibited by atropine and tetrodotoxin. The OXA-induced contraction was significantly inhibited by hexamethonium and SB-334867-A, whereas the nicotine-induced contraction was not inhibited by SB-334867-A. Descending relaxation was either partially or completely inhibited by l-nitroarginine and tetrodotoxin, respectively. Both SB-334867-A and hexamethonium partially inhibited descending relaxation. A combination of SB-334867-A and hexamethonium had an additive inhibitory effect on descending relaxation. Exogenous OXA, in the presence of atropine, induced a relaxation that was significantly inhibited by both l-nitroarginine and SB-334867-A, but not by hexamethonium. Nicotine in the presence of atropine relaxed the jejunal segment. SB-334867-A, unlike hexamethonium, did not affect nicotine-induced relaxation. These results suggest that OXA plays an important role in the ascending and descending neural reflexes in the mouse jejunum.

Micro-arousals during nocturnal sleep.

PubMed

Halász, P; Kundra, O; Rajna, P; Pál, I; Vargha, M

1979-01-01

In 8 young adult human subjects EEG- and polygraphic characteristics of transient shifts towards arousal (micro-arousal, MA) have been studied during sleep under five different experimental conditions in 40 night sessions. Out of the five applied experimental situations, two (psychostimulant application and sensory stimulation) resulted in a shift of the balance between the systems of sleep and arousal towards an increased activity of the arousal system, while an other condition (rebound following partial sleep deprivation) led to an opposite change to a rise in "sleep pressure". An inverse correlation has been found between the frequency of MA and the depth of sleep, a finding consistently observed in every subject and in every experimental situation. During the process of sleep periodic changes in the dispersity of MA could be seen; the number of MA-s decreased and increased according to the descending and ascending slope of the sleep cycles. During the ascending slope of cycles there was a coupling between the occurence of MA-s and the changes of phases. Increases in the level of activation and in sleep pressure did not influence the occurrence of MA-s. Increasing the tone of the arousal system in chemical way, or by means of enhancing the phasic sensory input resulted in a reduction of the difference between the number of MA on the descending and ascending slopes of cycles. During the phases of sleep, the spontaneous occurrence of MA-s went parallel with the possibility to evoke MA-s by sensory stimuli. These data show that MA is a regular phenomenon of nocturnal sleep; MA manifests itself as a result of phasic functioning of the reticular arousal system and plays a role in the organization of those periods of the sleep cycle, which tend toward arousal. It is suggested that MA-phenomenon is considered a standard measure of sleep and that it could represent an indicator of the function of the arousal system controlled by external or internal mechanisms during sleep.

Locus coeruleus phasic discharge is essential for stimulus-induced gamma oscillations in the prefrontal cortex.

PubMed

Neves, Ricardo M; van Keulen, Silvia; Yang, Mingyu; Logothetis, Nikos K; Eschenko, Oxana

2018-03-01

The locus coeruleus (LC) noradrenergic (NE) neuromodulatory system is critically involved in regulation of neural excitability via its diffuse ascending projections. Tonic NE release in the forebrain is essential for maintenance of vigilant states and increases the signal-to-noise ratio of cortical sensory responses. The impact of phasic NE release on cortical activity and sensory processing is less explored. We previously reported that LC microstimulation caused a transient desynchronization of population activity in the medial prefrontal cortex (mPFC), similar to noxious somatosensory stimuli. The LC receives nociceptive information from the medulla and therefore may mediate sensory signaling to its forebrain targets. Here we performed extracellular recordings in LC and mPFC while presenting noxious stimuli in urethane-anesthetized rats. A brief train of foot shocks produced a robust phasic response in the LC and a transient change in the mPFC power spectrum, with the strongest modulation in the gamma (30-90 Hz) range. The LC phasic response preceded prefrontal gamma power increase, and cortical modulation was proportional to the LC excitation. We also quantitatively characterized distinct cortical states and showed that sensory responses in both LC and mPFC depend on the ongoing cortical state. Finally, cessation of the LC firing by bilateral local iontophoretic injection of clonidine, an α 2 -adrenoreceptor agonist, completely eliminated sensory responses in the mPFC without shifting cortex to a less excitable state. Together, our results suggest that the LC phasic response induces gamma power increase in the PFC and is essential for mediating sensory information along an ascending noxious pathway. NEW & NOTEWORTHY Our study shows linear relationships between locus coeruleus phasic excitation and the amplitude of gamma oscillations in the prefrontal cortex. Results suggest that the locus coeruleus phasic response is essential for mediating sensory information along an ascending noxious pathway.

HV1 acts as a sodium sensor and promotes superoxide production in medullary thick ascending limb of Dahl salt-sensitive rats.

PubMed

Jin, Chunhua; Sun, Jingping; Stilphen, Carly A; Smith, Susan M E; Ocasio, Hiram; Bermingham, Brent; Darji, Sandip; Guha, Avirup; Patel, Roshan; Geurts, Aron M; Jacob, Howard J; Lambert, Nevin A; O'Connor, Paul M

2014-09-01

We previously characterized a H(+) transport pathway in medullary thick ascending limb nephron segments that when activated stimulated the production of superoxide by nicotinamide adenine dinucleotide phosphate oxidase. Importantly, the activity of this pathway was greater in Dahl salt-sensitive rats than salt-resistant (SS.13(BN)) rats, and superoxide production was enhanced in low Na(+) media. The goal of this study was to determine the molecular identity of this pathway and its relationship to Na(+). We hypothesized that the voltage-gated proton channel, HV1, was the source of superoxide-stimulating H(+) currents. To test this hypothesis, we developed HV1(-/-) null mutant rats on the Dahl salt-sensitive rat genetic background using zinc-finger nuclease gene targeting. HV1 could be detected in medullary thick limb from wild-type rats. Intracellular acidification using an NH4Cl prepulse in 0 sodium/BaCl2 containing media resulted in superoxide production in thick limb from wild-type but not HV1(-/-) rats (P<0.05) and more rapid recovery of intracellular pH in wild-type rats (ΔpHI 0.005 versus 0.002 U/s, P=0.046, respectively). Superoxide production was enhanced by low intracellular sodium (<10 mmol/L) in both thick limb and peritoneal macrophages only when HV1 was present. When fed a high-salt diet, blood pressure, outer medullary renal injury (tubular casts), and oxidative stress (4-hydroxynonenal staining) were significantly reduced in HV1(-/-) rats compared with wild-type Dahl salt-sensitive rats. We conclude that HV1 is expressed in medullary thick ascending limb and promotes superoxide production in this segment when intracellular Na(+) is low. HV1 contributes to the development of hypertension and renal disease in Dahl salt-sensitive rats. © 2014 American Heart Association, Inc.

Herpes simplex virus meningitis complicated by ascending paralysis

PubMed Central

Benjamin, Mina M.; Gummelt, Kyle L.; Zaki, Rabeea; Afzal, Aasim; Sloan, Louis

2013-01-01

A case of herpes simplex virus (HSV) meningitis complicated by ascending paralysis with almost complete recovery following antiviral treatment is reported. We present this case to illustrate the importance of including HSV-induced neuropathy in the differential diagnosis of acute neurologic symptoms following the viral illness. PMID:23814385

Endogenous flow-induced superoxide stimulates Na/H exchange activity via PKC in thick ascending limbs

PubMed Central

Garvin, Jeffrey L.

2014-01-01

Luminal flow stimulates Na reabsorption along the nephron and activates protein kinase C (PKC) which enhances endogenous superoxide (O2−) production by thick ascending limbs (TALs). Exogenously-added O2− augments TAL Na reabsorption, a process also dependent on PKC. Luminal Na/H exchange (NHE) mediates NaHCO3 reabsorption. However, whether flow-stimulated, endogenously-produced O2− enhances luminal NHE activity and the signaling pathway involved are unclear. We hypothesized that flow-induced production of endogenous O2− stimulates luminal NHE activity via PKC in TALs. Intracellular pH recovery was measured as an indicator of NHE activity in isolated, perfused rat TALs. Increasing luminal flow from 5 to 20 nl/min enhanced total NHE activity from 0.104 ± 0.031 to 0.167 ± 0.036 pH U/min, 81%. The O2− scavenger tempol decreased total NHE activity by 0.066 ± 0.011 pH U/min at 20 nl/min but had no significant effect at 5 nl/min. With the NHE inhibitor EIPA in the bath to block basolateral NHE, tempol reduced flow-enhanced luminal NHE activity by 0.029 ± 0.010 pH U/min, 30%. When experiments were repeated with staurosporine, a nonselective PKC inhibitor, tempol had no effect. Because PKC could mediate both induction of O2− by flow and the effect of O2− on luminal NHE activity, we used hypoxanthine/xanthine oxidase to elevate O2−. Hypoxanthine/xanthine oxidase increased luminal NHE activity by 0.099 ± 0.020 pH U/min, 137%. Staurosporine and the PKCα/β1-specific inhibitor Gö6976 blunted this effect. We conclude that flow-induced O2− stimulates luminal NHE activity in TALs via PKCα/β1. This accounts for part of flow-stimulated bicarbonate reabsorption by TALs. PMID:25080525

Why we forget our dreams: Acetylcholine and norepinephrine in wakefulness and REM sleep.

PubMed

Becchetti, Andrea; Amadeo, Alida

2016-01-01

The ascending fibers releasing norepinephrine and acetylcholine are highly active during wakefulness. In contrast, during rapid-eye-movement sleep, the neocortical tone is sustained mainly by acetylcholine. By comparing the different physiological features of the norepinephrine and acetylcholine systems in the light of the GANE (glutamate amplifies noradrenergic effects) model, we suggest how to interpret some functional differences between waking and rapid-eye-movement sleep.

Improvements of CO2 and O2 Transmission Modeling for ASCENDS Mission Applications

NASA Technical Reports Server (NTRS)

Pliutau, Denis; Prasad, Narashimha S.

2011-01-01

Simulations using the HITRAN database and other data have been carried out to select the optimum laser wavelengths for the measurements of CO2 and O2 concentrations with the application to the ASCENDS mission. The accuracy set forth for the ASCENDS mission requires accurate line-by-line calculations involving the use of non-Voigt line shapes. To aid in achieving this goal, improved CO2 and O2 transmission calculation methods are being developed. In particular, line-by-line transmission modeling of CO2 was improved by implementing non-Voigt spectral lineshapes. Ongoing work involves extending this approach to the O2 molecule 1.26-1.27micron spectral band.

Comparison of trunk acceleration ratios during stair negotiation in old-old females.

PubMed

Shin, Sun-Shil; Yoo, Won-Gyu

2016-06-01

[Purpose] This study compared trunk acceleration ratios in old-old adult females during stair negotiation. [Subjects and Methods] Twelve old-old adult females who could walk independently volunteered for this study. This study measured gait time and trunk acceleration ratios using an accelerometer during ascending and descending stairs [Results] The trunk acceleration ratio when descending stairs was significantly higher than that when ascending stairs. [Conclusion] These findings suggest that old-old females have greater deterioration of upper trunk control function for descending than for ascending stairs, regardless of task time. In addition, the trunk acceleration ratio during stair negotiation is a useful clinical marker to predict function and balance control ability in old-old females.

Time course of pressure and flow in ascending aorta during ejection.

PubMed

Perlini, S; Soldà, P L; Piepoli, M; Calciati, A; Paro, M; Marchetti, G; Meno, F; Finardi, G; Bernardi, L

1991-02-01

To analyze aortic flow and pressure relationships, 10 closed-chest anaesthetised dogs were instrumented with electromagnetic aortic flow probes and micromanometers in the left ventricle and ascending aorta. Left ventricular ejection time was divided into: time to peak flow (T1) (both pressure and flow rising), peak flow to peak pressure time (T2) (pressure rising, flow decreasing), and peak pressure to dicrotic notch time (T3) (pressure and flow both decreasing). These time intervals were expressed as percent of total ejection time. Load-active interventions rose markedly T2 (from 4.2 +/- 5.5 to 19.4 +/- 3.5 after phenylephrine (p less than 0.02); from 4.2 +/- 6.5 to 21.2 +/- 5.3 after dextran (p less than 0.02)). Conversely, dobutamine reduced T2 from 4.4 +/- 5.9 to -2.5 +/- 6.5 (p less than 0.05). Thus, during load-active interventions aortic pressure increases for a longer T2 time although forward flow is decreasing, as a result of higher aortic elastic recoil during ejection. Conversely, beta 1-adrenergic stimulation significantly shortens T2. Dynamic pressure-flow relationship is thus continuously changing during ejection. T2 seems to be inversely related to the efficiency of left ventricular ejection dynamics.

Expression of Heme Oxygenase-1 in Thick Ascending Loop of Henle Attenuates Angiotensin II-Dependent Hypertension

PubMed Central

Drummond, Heather A.; Gousette, Monette U.; Storm, Megan V.; Abraham, Nader G.; Csongradi, Eva

2012-01-01

Kidney-specific induction of heme oxygenase-1 (HO-1) attenuates the development of angiotensin II (Ang II) -dependent hypertension, but the relative contribution of vascular versus tubular induction of HO-1 is unknown. To determine the specific contribution of thick ascending loop of Henle (TALH) -derived HO-1, we generated a transgenic mouse in which the uromodulin promoter controlled expression of human HO-1. Quantitative RT-PCR and confocal microscopy confirmed successful localization of the HO-1 transgene to TALH tubule segments. Medullary HO activity, but not cortical HO activity, was significantly higher in transgenic mice than control mice. Enhanced TALH HO-1 attenuated the hypertension induced by Ang II delivered by an osmotic minipump for 10 days (139±3 versus 153±2 mmHg in the transgenic and control mice, respectively; P<0.05). The lower blood pressure in transgenic mice associated with a 60% decrease in medullary NKCC2 transporter expression determined by Western blot. Transgenic mice also exhibited a 36% decrease in ouabain-sensitive sodium reabsorption and a significantly attenuated response to furosemide in isolated TALH segments,. In summary, these results show that increased levels of HO-1 in the TALH can lower blood pressure by a mechanism that may include alterations in NKCC2-dependent sodium reabsorption. PMID:22323644

SPAK and OSR1 play essential roles in potassium homeostasis through actions on the distal convoluted tubule

PubMed Central

Ferdaus, Mohammed Z.; Barber, Karl W.; López‐Cayuqueo, Karen I.; Terker, Andrew S.; Argaiz, Eduardo R.; Gassaway, Brandon M.; Chambrey, Régine; Gamba, Gerardo; Rinehart, Jesse

2016-01-01

Key points STE20 (Sterile 20)/SPS‐1 related proline/alanine‐rich kinase (SPAK) and oxidative stress‐response kinase‐1 (OSR1) phosphorylate and activate the renal Na+–K+–2Cl− cotransporter 2 (NKCC2) and Na+Cl− cotransporter (NCC).Mouse models suggest that OSR1 mainly activates NKCC2‐mediated sodium transport along the thick ascending limb, while SPAK mainly activates NCC along the distal convoluted tubule, but the kinases may compensate for each other. We hypothesized that disruption of both kinases would lead to polyuria and severe salt‐wasting, and generated SPAK/OSR1 double knockout mice to test this.Despite a lack of SPAK and OSR1, phosphorylated NKCC2 abundance was still high, suggesting the existence of an alternative activating kinase.Compensatory changes in SPAK/OSR1‐independent phosphorylation sites on both NKCC2 and NCC and changes in sodium transport along the collecting duct were also observed.Potassium restriction revealed that SPAK and OSR1 play essential roles in the emerging model that NCC activation is central to sensing changes in plasma [K+]. Abstract STE20 (Sterile 20)/SPS‐1 related proline/alanine‐rich kinase (SPAK) and oxidative stress‐response kinase‐1 (OSR1) activate the renal cation cotransporters Na+–K+–2Cl− cotransporter (NKCC2) and Na+–Cl− cotransporter (NCC) via phosphorylation. Knockout mouse models suggest that OSR1 mainly activates NKCC2, while SPAK mainly activates NCC, with possible cross‐compensation. We tested the hypothesis that disrupting both kinases causes severe polyuria and salt‐wasting by generating SPAK/OSR1 double knockout (DKO) mice. DKO mice displayed lower systolic blood pressure compared with SPAK knockout (SPAK‐KO) mice, but displayed no severe phenotype even after dietary salt restriction. Phosphorylation of NKCC2 at SPAK/OSR1‐dependent sites was lower than in SPAK‐KO mice, but still significantly greater than in wild type mice. In the renal medulla, there was significant phosphorylation of NKCC2 at SPAK/OSR1‐dependent sites despite a complete absence of SPAK and OSR1, suggesting the existence of an alternative activating kinase. The distal convoluted tubule has been proposed to sense plasma [K+], with NCC activation serving as the primary effector pathway that modulates K+ secretion, by metering sodium delivery to the collecting duct. Abundance of phosphorylated NCC (pNCC) is dramatically lower in SPAK‐KO mice than in wild type mice, and the additional disruption of OSR1 further reduced pNCC. SPAK‐KO and kidney‐specific OSR1 single knockout mice maintained plasma [K+] following dietary potassium restriction, but DKO mice developed severe hypokalaemia. Unlike mice lacking SPAK or OSR1 alone, DKO mice displayed an inability to phosphorylate NCC under these conditions. These data suggest that SPAK and OSR1 are essential components of the effector pathway that maintains plasma [K+]. PMID:27068441

High sodium intake increases HCO3− absorption in medullary thick ascending limb through adaptations in basolateral and apical Na+/H+ exchangers

PubMed Central

George, Thampi; Watts, Bruns A.

2011-01-01

A high sodium intake increases the capacity of the medullary thick ascending limb (MTAL) to absorb HCO3−. Here, we examined the role of the apical NHE3 and basolateral NHE1 Na+/H+ exchangers in this adaptation. MTALs from rats drinking H2O or 0.28 M NaCl for 5–7 days were perfused in vitro. High sodium intake increased HCO3− absorption rate by 60%. The increased HCO3− absorptive capacity was mediated by an increase in apical NHE3 activity. Inhibiting basolateral NHE1 with bath amiloride eliminated 60% of the adaptive increase in HCO3− absorption. Thus the majority of the increase in NHE3 activity was dependent on NHE1. A high sodium intake increased basolateral Na+/H+ exchange activity by 89% in association with an increase in NHE1 expression. High sodium intake increased apical Na+/H+ exchange activity by 30% under conditions in which basolateral Na+/H+ exchange was inhibited but did not change NHE3 abundance. These results suggest that high sodium intake increases HCO3− absorptive capacity in the MTAL through 1) an adaptive increase in basolateral NHE1 activity that results secondarily in an increase in apical NHE3 activity; and 2) an adaptive increase in NHE3 activity, independent of NHE1 activity. These studies support a role for NHE1 in the long-term regulation of renal tubule function and suggest that the regulatory interaction whereby NHE1 enhances the activity of NHE3 in the MTAL plays a role in the chronic regulation of HCO3− absorption. The adaptive increases in Na+/H+ exchange activity and HCO3− absorption in the MTAL may play a role in enabling the kidneys to regulate acid-base balance during changes in sodium and volume balance. PMID:21613418

Pathogenetic Basis of Aortopathy and Aortic Valve Disease

ClinicalTrials.gov

2018-02-19

Aortopathies; Thoracic Aortic Aneurysm; Aortic Valve Disease; Thoracic Aortic Disease; Thoracic Aortic Dissection; Thoracic Aortic Rupture; Ascending Aortic Disease; Descending Aortic Disease; Ascending Aortic Aneurysm; Descending Aortic Aneurysm; Marfan Syndrome; Loeys-Dietz Syndrome; Ehlers-Danlos Syndrome; Shprintzen-Goldberg Syndrome; Turner Syndrome; PHACE Syndrome; Autosomal Recessive Cutis Laxa; Congenital Contractural Arachnodactyly; Arterial Tortuosity Syndrome

Dual-task interference effects on cross-modal numerical order and sound intensity judgments: the more the louder?

PubMed

Alards-Tomalin, Doug; Walker, Alexander C; Nepon, Hillary; Leboe-McGowan, Launa C

2017-09-01

In the current study, cross-task interactions between number order and sound intensity judgments were assessed using a dual-task paradigm. Participants first categorized numerical sequences composed of Arabic digits as either ordered (ascending, descending) or non-ordered. Following each number sequence, participants then had to judge the intensity level of a target sound. Experiment 1 emphasized processing the two tasks independently (serial processing), while Experiments 2 and 3 emphasized processing the two tasks simultaneously (parallel processing). Cross-task interference occurred only when the task required parallel processing and was specific to ascending numerical sequences, which led to a higher proportion of louder sound intensity judgments. In Experiment 4 we examined whether this unidirectional interaction was the result of participants misattributing enhanced processing fluency experienced on ascending sequences as indicating a louder target sound. The unidirectional finding could not be entirely attributed to misattributed processing fluency, and may also be connected to experientially derived conceptual associations between ascending number sequences and greater magnitude, consistent with conceptual mapping theory.

Ascending neural pathways in the rat ileum in vitro--effect of capsaicin and involvement of nitric oxide.

PubMed

Allescher, H D; Sattler, D; Piller, C; Schusdziarra, V; Classen, M

1992-07-07

The aim of the present study was to develop and characterize an in vitro model of the rat ileum in which activation of the orally projecting neural excitatory pathway of the myenteric reflex is produced by electrical field stimulation anally to the recording site. The motility of a 10-cm segment of rat ileum was recorded using a perfused manometric assembly with side holes 2 and 4 cm orally to the stimulation site. Electrical field stimulation caused a contractile response in the oral but not in the aboral direction of the stimulation site. The contractile response, which was maximal using low stimulus frequencies (3 or 5 pulses per second (pps)) and decreased with higher frequencies (10 or 20 pps), was blocked by atropine (10(-6) M) at all frequencies tested after acute and after prolonged (greater than 30 min) treatment. The maximal contractile response at 3 pps was abolished by hexamethonium (10(-4) M), tetrodotoxin (5 x 10(-7) M) and by complete transection of the muscular wall between the stimulation and the recording site. Acute administration of capsaicin (8 x 10(-7) M) to the bath reduced the lag between the start of the electrical stimulation and the onset of the contractile response. Higher concentrations of capsaicin (10(-5) M) reduced the contractile response, but this was partly due to an unspecific effect of capsaicin. Blockade of nitric oxide (NO) synthesis by L-NG-nitro-arginine-methyl ester (L-NAME) (3 x 10(-4) M) augmented the contractile response to anal stimulation by 222.4% and reduced the lag period by 54.5%, whereas the stereoisomer D-NAME had no significant effect. The potentiating effects of L-NAME were reversed in the presence of L-arginine (3 x 10(-3) M) but not in the presence of the stereoisomer D-arginine (3 x 10(-3) M). This model can be used to study ascending neural pathways in the rat small intestine. The ascending excitatory response is abolished by atropine and hexamethonium and is modulated by capsicin-sensitive fibers. The ascending pathway is under tonic inhibition of metabolites of the L-arginine-NO pathway.

Comparison of Surface and Column Variations of CO2 Over Urban Areas for Future Active Remote CO2 Sensors

NASA Technical Reports Server (NTRS)

Choi, Yonghoon; Yang, Melissa; Kooi, Susan; Browell, Edward

2015-01-01

High resolution in-situ CO2 measurements were recorded onboard the NASA P-3B during the DISCOVER-AQ (Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality) Field Campaign, to investigate the ability of space-based observations to accurately assess near surface conditions related to air quality. This campaign includes, Washington DC/Baltimore, MD (July 2011), San Joaquin Valley, CA (January - February 2013), Houston, TX (September 2013), and Denver, CO (July-August 2014). Each of these campaigns consisted of missed approaches and approximately two hundred vertical soundings of CO2 within the lower troposphere (surface to about 5 km). In this study, surface (0 - 1 km) and column-averaged (0 - 3.5 km) CO2 mixing ratio values from the vertical soundings in the four geographically different urban areas are used to investigate the temporal and spatial variability of CO2 within the different urban atmospheric emission environments. Tracers such as CO, CH2O, NOx, and NMHCs are used to identify the source of CO2 variations in the urban sites. Additionally, we apply nominal CO2 column weighting functions for potential future active remote CO2 sensors operating in the 1.57-microns and 2.05-microns measurement regions to convert the in situ CO2 vertical mixing ratio profiles to variations in CO2 column optical depths, which is what the active remote sensors actually measure. Using statistics calculated from the optical depths at each urban site measured during the DISCOVER-AQ field campaign and for each nominal weighting function, we investigate the natural variability of CO2 columns in the lower troposphere; relate the CO2 column variability to the urban surface emissions; and show the measurement requirements for the future ASCENDS (Active Sensing of CO2 Emissions over Nights, Days, and Seasons) in the continental U.S. urban areas.

Asymmetric top-down modulation of ascending visual pathways in pigeons.

PubMed

Freund, Nadja; Valencia-Alfonso, Carlos E; Kirsch, Janina; Brodmann, Katja; Manns, Martina; Güntürkün, Onur

2016-03-01

Cerebral asymmetries are a ubiquitous phenomenon evident in many species, incl. humans, and they display some similarities in their organization across vertebrates. In many species the left hemisphere is associated with the ability to categorize objects based on abstract or experience-based behaviors. Using the asymmetrically organized visual system of pigeons as an animal model, we show that descending forebrain pathways asymmetrically modulate visually evoked responses of single thalamic units. Activity patterns of neurons within the nucleus rotundus, the largest thalamic visual relay structure in birds, were differently modulated by left and right hemispheric descending systems. Thus, visual information ascending towards the left hemisphere was modulated by forebrain top-down systems at thalamic level, while right thalamic units were strikingly less modulated. This asymmetry of top-down control could promote experience-based processes within the left hemisphere, while biasing the right side towards stimulus-bound response patterns. In a subsequent behavioral task we tested the possible functional impact of this asymmetry. Under monocular conditions, pigeons learned to discriminate color pairs, so that each hemisphere was trained on one specific discrimination. Afterwards the animals were presented with stimuli that put the hemispheres in conflict. Response patterns on the conflicting stimuli revealed a clear dominance of the left hemisphere. Transient inactivation of left hemispheric top-down control reduced this dominance while inactivation of right hemispheric top-down control had no effect on response patterns. Functional asymmetries of descending systems that modify visual ascending pathways seem to play an important role in the superiority of the left hemisphere in experience-based visual tasks. Copyright © 2015. Published by Elsevier Ltd.

Frontal Joint Dynamics when Initiating Stair Ascent from a Walk versus a Stand

PubMed Central

Vallabhajosula, Srikant; Yentes, Jennifer M.; Stergiou, Nicholas

2011-01-01

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42±0.21m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). PMID:22172606

Reassessment of the structural basis of the ascending arousal system

PubMed Central

Fuller, Patrick M.; Sherman, David; Pedersen, Nigel P.; Saper, Clifford B.; Lu, Jun

2011-01-01

The “ascending reticular activating system” theory proposed that neurons in the upper brainstem reticular formation projected to forebrain targets that promoted wakefulness. More recent formulations have emphasized that most neurons at the pontomesencepahlic junction that participate in these pathways are actually in monoaminergic and cholinergic cell groups. However, cell-specific lesions of these cell groups have never been able to reproduce the deep coma seen after acute paramedian midbrain lesions that transect ascending axons at the caudal midbrain level. To determine whether the cortical afferents from the thalamus or the basal forebrain were more important in maintaining arousal, we first place large cell-body specific lesions in these targets. Surprisingly, extensive thalamic lesions had little effect on EEG or behavioral measures of wakefulness or on c-Fos expression by cortical neurons during wakefulness. In contrast, animals with large basal forebrain lesions were behaviorally unresponsive, had a monotonous sub-1 Hz EEG, and little cortical c-Fos expression during continuous gentle handling. We then retrogradely labeled inputs to the basal forebrain from the upper brainstem, and found a substantial input from glutamatergic neurons in the parabrachial nucleus and adjacent pre-coeruleus area. Cell specific lesions of the parabrachial-precoeruleus complex produced behavioral unresponsiveness, a monotonous sub-1Hz cortical EEG, and loss of cortical c-Fos expression during gentle handling. These experiments indicate that in rats the reticulo-thalamo-cortical pathway may play a very limited role in behavioral or electrocortical arousal, while the projection from the parabrachial nucleus and precoeruleus region, relayed by the basal forebrain to the cerebral cortex, may be critical for this process. PMID:21280045

Expression of platelet-derived growth factor B is upregulated in patients with thoracic aortic dissection.

PubMed

Meng, Weixin; Liu, Shangdian; Li, Dandan; Liu, Zonghong; Yang, Hui; Sun, Bo; Liu, Hongyu

2018-04-20

Thoracic aortic dissection (TAD) is a serious condition requiring urgent treatment to avoid catastrophic consequences. The inflammatory response is involved in the occurrence and development of TAD, possibly potentiated by platelet-derived growth factors (PDGFs). This study aimed to determine whether expression of PDGF-B (a subunit of PDGF-BB) was increased in TAD patients and to explore the factors responsible for its upregulation and subsequent effects on TAD. Full-thickness ascending aorta wall specimens from TAD patients (n = 15) and control patients (n = 10) were examined for expression of PDGF-B and its receptor (PDGFRB) and in terms of morphology, inflammation, and fibrosis. Blood samples from TAD and control patients were collected to detect plasma levels of PDGF-BB and soluble elastins. Expression levels of PDGF-B, PDGFRB, and collagen I were significantly enhanced in ascending aorta wall specimens from TAD patients compared with controls. Furthermore, soluble elastic fragments and PDGF-BB were significantly increased in plasma from TAD patients compared with controls, and numerous irregular elastic fibers and macrophages were seen in the ascending aorta wall in TAD patients. An increase in elastic fragments in the aorta wall might be responsible for inducing the activation and migration of macrophages to injured sites, leading to elevated expression of PDGF-B, which in turn induces deposition of collagen, disrupts extracellular matrix homeostasis, and increases the stiffness of the aorta wall, resulting in compromised aorta compliance. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Septal projections to nucleus incertus in the rat: bidirectional pathways for modulation of hippocampal function.

PubMed

Sánchez-Pérez, Ana M; Arnal-Vicente, Isabel; Santos, Fabio N; Pereira, Celia W; ElMlili, Nisrin; Sanjuan, Julio; Ma, Sherie; Gundlach, Andrew L; Olucha-Bordonau, Francisco E

2015-03-01

Projections from the nucleus incertus (NI) to the septum have been implicated in the modulation of hippocampal theta rhythm. In this study we describe a previously uncharacterized projection from the septum to the NI, which may provide feedback modulation of the ascending circuitry. Fluorogold injections into the NI resulted in retrograde labeling in the septum that was concentrated in the horizontal diagonal band and areas of the posterior septum including the septofimbrial and triangular septal nuclei. Double-immunofluorescent staining indicated that the majority of NI-projecting septal neurons were calretinin-positive and some were parvalbumin-, calbindin-, or glutamic acid decarboxylase (GAD)-67-positive. Choline acetyltransferase-positive neurons were Fluorogold-negative. Injection of anterograde tracers into medial septum, or triangular septal and septofimbrial nuclei, revealed fibers descending to the supramammillary nucleus, median raphe, and the NI. These anterogradely labeled varicosities displayed synaptophysin immunoreactivity, indicating septal inputs form synapses on NI neurons. Anterograde tracer also colocalized with GAD-67-positive puncta in labeled fibers, which in some cases made close synaptic contact with GAD-67-labeled NI neurons. These data provide evidence for the existence of an inhibitory descending projection from medial and posterior septum to the NI that provides a "feedback loop" to modulate the comparatively more dense ascending NI projections to medial septum and hippocampus. Neural processes and associated behaviors activated or modulated by changes in hippocampal theta rhythm may depend on reciprocal connections between ascending and descending pathways rather than on unidirectional regulation via the medial septum. © 2014 Wiley Periodicals, Inc.

Asymmetric variations in the tropical ascending branches of Hadley circulations and the associated mechanisms and effects

NASA Astrophysics Data System (ADS)

Sun, Bo

2018-03-01

This study investigates the variations in the tropical ascending branches (TABs) of Hadley circulations (HCs) during past decades, using a variety of reanalysis datasets. The northern tropical ascending branch (NTAB) and the southern tropical ascending branch (STAB), which are defined as the ascending branches of the Northern Hemisphere HC and Southern Hemisphere HC, respectively, are identified and analyzed regarding their trends and variability. The reanalysis datasets consistently show a persistent increase in STAB during past decades, whereas they show less consistency in NTAB regarding its decadalto multidecadal variability, which generally features a decreasing trend. These asymmetric trends in STAB and NTAB are attributed to asymmetric trends in the tropical SSTs. The relationship between STAB/NTAB and tropical SSTs is further examined regarding their interannual and decadal- to multidecadal variability. On the interannual time scale, the STAB and NTAB are essentially modulated by the eastern-Pacific type of ENSO, with a strengthened (weakened) STAB (NTAB) under an El Niño condition. On the decadal- to multidecadal time scale, the variability of STAB and NTAB is closely related to the southern tropical SSTs and the meridional asymmetry of global tropical SSTs, respectively. The tropical eastern Pacific SSTs (southern tropical SSTs) dominate the tropical SST-NTAB/STAB relationship on the interannual (decadal- to multidecadal) scale, whereas the NTAB is a passive factor in this relationship. Moreover, a cross-hemispheric relationship between the NTAB/STAB and the HC upper-level meridional winds is revealed.

Alcohol affects executive cognitive functioning differentially on the ascending versus descending limb of the blood alcohol concentration curve.

PubMed

Pihl, Robert O; Paylan, Sheila S; Gentes-Hawn, Alyson; Hoaken, Peter N S

2003-05-01

Executive cognitive functioning (ECF), a construct that includes cognitive abilities such as planning, abstract reasoning, and the capacity to govern self-directed behavior, has been recently researched as an antecedent to many forms of psychopathology and has been implicated in alcohol-related aggression. This study was designed to examine whether differential ECF impairments can be noted on the ascending versus the descending limbs of the blood alcohol concentration curve. Forty-one male university students participated in this study. Twenty-one subjects were given 1.32 ml of 95% alcohol per kilogram of body weight, mixed with orange juice, and the remaining 20 were given a placebo. Participants were randomly assigned to either an ascending or descending blood alcohol group and were tested on six tests of ECF on their assigned limb. Subjective mood data were also collected. Intoxicated participants on both limbs demonstrated ECF impairment; the descending-limb group showed greater impairment than their ascending-limb counterparts. Intoxicated subjects were significantly more anxious at baseline than placebo subjects. The introduction of this covariate nullified any significant differences in subjective mood found on either limb of the blood alcohol concentration curve, but ECF impairments remained robust. Our results support the conclusion that alcohol negatively affects cognitive performance and has a differential effect on the descending versus the ascending limb of the blood alcohol concentration curve. The latter finding may have important ramifications relating to the detrimental consequences of alcohol intoxication.

Regional Differences in Stem and Transit Cell Proliferation and Apoptosis in the Terminal Ileum and Colon of Mice After 12 Gy

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

Gandara, Ricardo M.C.; Mahida, Yashwant R., E-mail: yash.mahida@nottingham.ac.uk; Potten, Christopher S.

2012-03-01

Purpose: The intestinal epithelium has a high rate of cell turnover, which is regulated by stem cells located near the base of crypts. We aimed to investigate stem cell-dependent characteristics of cell proliferation, apoptosis, and crypt size in terminal ileum and different regions of the colon. Methods and Materials: Mice were studied under steady-state conditions and after radiation-induced stem cell apoptosis. Percentage of proliferating or apoptotic cells at a particular cell position (cp) along the crypt axis was expressed as labeling or apoptotic index. Results: Under steady-state conditions: crypt size was smallest in the ascending colon. In contrast to othermore » regions of the colon, the distribution profile of proliferating cells in ascending colon showed some similarity to that in the terminal ileum. Postirradiation: apoptotic cells were prominent at the bottom of the crypt of mid- and descending colon but in the ascending colon, they were seen with similar frequency from cp 1 to 4. During regeneration, a constant proliferative capacity was seen above Paneth cells in the terminal ileum. In the ascending (but not mid- or descending) colon, the profile of proliferating cells over the first 4 days after irradiation showed a similarity to that in the terminal ileum. Conclusions: Profiles of proliferating epithelial cells (under steady-state conditions and postirradiation) and apoptotic cells (postirradiation) suggest similarities in the location of stem cells in the ascending colon and terminal ileum.« less

Transcardiac endograft delivery for endovascular treatment of the ascending aorta: a feasibility study in pigs.

PubMed

Wipper, Sabine; Lohrenz, Christina; Ahlbrecht, Oliver; Carpenter, Sebastian W; Tsilimparis, Nikolaos; Kersten, Jan Felix; Detter, Christian; Debus, Eike S; Kölbel, Tilo

2015-06-01

To compare the technical feasibility and hemodynamic alterations during antegrade transcardiac access routes vs conventional transfemoral access (TFA) for endovascular treatment of the ascending aorta in a porcine model. Antegrade transseptal access (TSA), transapical access (TAA), and TFA were used for implantation of custom-made endografts into the ascending aorta under fluoroscopy (6 pigs each). Hemodynamic parameters, myocardial and cerebral blood flow, and carotid artery blood flow were evaluated during baseline (T1), sheath advancement (T2), after sheath retraction (T3), and after endograft deployment (T4). Endograft deployment was feasible in all animals; all coronary arteries remained patent. Hemodynamic parameters were comparable in all 3 study groups during all measurements. During T2, transient hemodynamic alteration occurred in all groups, with transient severe valve insufficiency in TSA and TAA reflected by the higher pulmonary to mean arterial pressure ratio (p<0.05) as compared with TFA. Values stabilized again at T3 and remained stable until T4. The innominate artery was partially occluded in 4 (TSA), 3 (TAA), and 5 (TFA) animals. There was no deterioration of myocardial or cerebral perfusion during the procedures. Endograft deployment and fluoroscopy times during TAA were shorter than in TSA and TFA. TSA, TFA, and TAA to the ascending aorta are feasible for endograft delivery to the ascending aorta in a porcine model. Transient hemodynamic instability in TSA and TAA recovered to near preoperative values. TAA appeared technically easier. © The Author(s) 2015.

Shear stress increases nitric oxide production in thick ascending limbs

PubMed Central

Cabral, Pablo D.; Hong, Nancy J.

2010-01-01

We showed that luminal flow stimulates nitric oxide (NO) production in thick ascending limbs. Ion delivery, stretch, pressure, and shear stress all increase when flow is enhanced. We hypothesized that shear stress stimulates NO in thick ascending limbs, whereas stretch, pressure, and ion delivery do not. We measured NO in isolated, perfused rat thick ascending limbs using the NO-sensitive dye DAF FM-DA. NO production rose from 21 ± 7 to 58 ± 12 AU/min (P < 0.02; n = 7) when we increased luminal flow from 0 to 20 nl/min, but dropped to 16 ± 8 AU/min (P < 0.02; n = 7) 10 min after flow was stopped. Flow did not increase NO in tubules from mice lacking NO synthase 3 (NOS 3). Flow stimulated NO production by the same extent in tubules perfused with ion-free solution and physiological saline (20 ± 7 vs. 24 ± 6 AU/min; n = 7). Increasing stretch while reducing shear stress and pressure lowered NO generation from 42 ± 9 to 17 ± 6 AU/min (P < 0.03; n = 6). In the absence of shear stress, increasing pressure and stretch had no effect on NO production (2 ± 8 vs. 8 ± 8 AU/min; n = 6). Similar results were obtained in the presence of tempol (100 μmol/l), a O2− scavenger. Primary cultures of thick ascending limb cells subjected to shear stresses of 0.02 and 0.55 dyne/cm2 produced NO at rates of 55 ± 10 and 315 ± 93 AU/s, respectively (P < 0.002; n = 7). Pretreatment with the NOS inhibitor l-NAME (5 mmol/l) blocked the shear stress-induced increase in NO production. We concluded that shear stress rather than pressure, stretch, or ion delivery mediates flow-induced stimulation of NO by NOS 3 in thick ascending limbs. PMID:20719980

Aortic Dissection in Patients With Bicuspid Aortic Valve–Associated Aneurysms

PubMed Central

Wojnarski, Charles M.; Svensson, Lars G.; Roselli, Eric E.; Idrees, Jay J.; Lowry, Ashley M.; Ehrlinger, John; Pettersson, Gösta B.; Gillinov, A. Marc; Johnston, Douglas R.; Soltesz, Edward G.; Navia, Jose L.; Hammer, Donald F.; Griffin, Brian; Thamilarasan, Maran; Kalahasti, Vidyasagar; Sabik, Joseph F.; Blackstone, Eugene H.; Lytle, Bruce W.

2016-01-01

Background Data regarding the risk of aortic dissection in patients with bicuspid aortic valve and large ascending aortic diameter are limited, and appropriate timing of prophylactic ascending aortic replacement lacks consensus. Thus our objectives were to determine the risk of aortic dissection based on initial cross-sectional imaging data and clinical variables and to isolate predictors of aortic intervention in those initially prescribed serial surveillance imaging. Methods From January 1995 to January 2014, 1,181 patients with bicuspid aortic valve underwent cross-sectional computed tomography (CT) or magnetic resonance imaging (MRI) to ascertain sinus or tubular ascending aortic diameter greater than or equal to 4.7 cm. Random Forest classification was used to identify risk factors for aortic dissection, and among patients undergoing surveillance, time-related analysis was used to identify risk factors for aortic intervention. Results Prevalence of type A dissection that was detected by imaging or was found at operation or on follow-up was 5.3% (n = 63). Probability of type A dissection increased gradually at a sinus diameter of 5.0 cm—from 4.1% to 13% at 7.2 cm—and then increased steeply at an ascending aortic diameter of 5.3 cm—from 3.8% to 35% at 8.4 cm—corresponding to a cross-sectional area to height ratio of 10 cm2/m for sinuses of Valsalva and 13 cm2/m for the tubular ascending aorta. Cross-sectional area to height ratio was the best predictor of type A dissection (area under the curve [AUC] = 0.73). Conclusions Early prophylactic ascending aortic replacement in patients with bicuspid aortic valve should be considered at high-volume aortic centers to reduce the high risk of preventable type A dissection in those with aortas larger than approximately 5.0 cm or with a cross-sectional area to height ratio greater than approximately 10 cm2/m. PMID:26209494

Aortic elongation and the risk for dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project†.

PubMed

Krüger, Tobias; Oikonomou, Alexandre; Schibilsky, David; Lescan, Mario; Bregel, Katharina; Vöhringer, Luise; Schneider, Wilke; Lausberg, Henning; Blumenstock, Gunnar; Bamberg, Fabian; Schlensak, Christian

2017-06-01

We measured aortic dimensions, particularly length parameters, using 3D imaging with the aim of refining the risk-morphology for Stanford type A aortic dissection (TAD). Computer tomography angiography studies were analysed using the curved multiplanar reformats. At defined landmarks, the diameters and lengths of aortic segments were recorded. Three groups were compared retrospectively: patients actually suffering from a TAD (TAD-group; n  = 150), patients before suffering a TAD (preTAD-group n  = 15) and a healthy control group ( n  = 215). Receiver operating characteristic curves (ROCs) were analysed (control versus preTAD) to study the diagnostic value of the individual variables. Median diameters of preTAD (43 mm) and TAD (50 mm) aortas were significantly ( P  < 0.001) larger than those of the control group (35 mm). Ninety-three percent of preTAD and 68% of TAD aortas were less than 55 mm in the mid-ascending aorta. The ascending aorta and the aortic arch were significantly longer in both preTAD and TAD aortas compared to control aortas ( P  < 0.001); in the control aortas the central line distance from the aortic valve to the brachiocephalic trunk was 93 mm. In preTAD aortas, it was 111 mm, and it was 117 mm in TAD aortas ( P  < 0.001). In ROC analysis, the area under the curve was 0.912 for the ascending diameter and 0.787 for the ascending and arch lengths. TAD-prediction based on the aortic diameter is ineffective. Besides circumferential dilatation, ascending aorta elongation precedes TAD and appears to be a useful additional parameter for prognostication. We propose a diagnostic score involving ascending aorta diameter and length. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Aortic elongation in aortic aneurysm and dissection: the Tübingen Aortic Pathoanatomy (TAIPAN) project.

PubMed

Krüger, Tobias; Sandoval Boburg, Rodrigo; Lescan, Mario; Oikonomou, Alexandre; Schneider, Wilke; Vöhringer, Luise; Lausberg, Henning; Bamberg, Fabian; Blumenstock, Gunnar; Schlensak, Christian

2018-01-24

To study the lengths and diameters of aortic segments in healthy and diseased aortas and to assess the role of aortic elongation in Type A aortic dissection (TAD) prediction. Ectasia and aneurysm were defined by ascending aorta diameters of 45-54 mm and ≥55 mm, respectively. Computed tomography angiography studies of 256 healthy, 102 ectasia, 38 aneurysm, 17 pre-TAD and 166 TAD aortas were analysed using curved multiplanar reformats. The study groups were structurally equal. The diameter of the ascending aorta was 35 mm in the control group and was larger (P < 0.001) in the pre-TAD (43 mm) and TAD (56 mm) groups. The length of the ascending aorta from the aortic annulus to the brachiocephalic trunk was 92 mm in the control group, 113 mm in the ectasia group, 120 mm in the aneurysm group and 111 mm and 118 mm in the pre-TAD and TAD groups (all P < 0.001 compared with the control group). An ascending aorta length of 120 mm was exceeded in 2% of the control group, 31% of the ectasia group, 50% of the aneurysm group, 24% of the pre-TAD group and 48% of the TAD group. The correlation between the diameter and the length of the ascending aorta was r = 0.752; therefore, both parameters must be examined separately. A score considering both parameters identified 23.5% of pre-TAD patients, significantly more than the diameter alone, and 31.4% of ectasia aortas were elongated. Patients with ectatic (45-54 mm diameter) and elongated (≥120 mm) ascending aortas represent a high-risk subpopulation for TAD. © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Pathways of volatile migration in the crust beneath Harrat Lunayyir (Saudi Arabia) during the unrest in 2009 revealed by attenuation tomography

NASA Astrophysics Data System (ADS)

Sychev, Ilya; Koulakov, Ivan; El Khrepy, Sami; Al-Arifi, Nassir

2017-01-01

Harrat Lunayyir is a relatively young basaltic field in Saudi Arabia located at the western margin of the Arabian Peninsula. In April-June 2009, strong seismic activity and ground deformations at this site marked the activation of the magma system beneath Harrat Lunayyir. In this study, we present new three-dimensional models of the attenuation of P and S waves during the unrest in 2009 based on the analysis of t*. We measured 1658 and 3170 values of t* for P and S waves, respectively, for the same earthquakes that were previously used for travel time tomography. The resulting anomalies of the P and S wave attenuation look very similar. In the center of the study area, we observe a prominent high-attenuation pattern, which coincides with the most active seismicity at shallow depths and maximum ground deformations. This high-attenuation zone may represent a zone of accumulation and ascending of gases, which originated at depths of 5-7 km due to the decompression of ascending liquid volatiles. Based on these findings and previous tomography studies, we propose that the unrest at Harrat Lunayyir in 2009 was triggered by a sudden injection of unstable liquid volatiles from deeper magma sources. At some depths, they were transformed to gases, which caused the volume to increase, and this led to seismic activation in the areas of phase transformations. The overpressurized gases ultimately found the weakest point in the rigid basaltic cover at the junction of several tectonic faults and escaped to the surface.

Pathways of volatile migration in the crust beneath Harrat Lunayyir (Saudi Arabia) during the unrest in 2009 revealed by attenuation tomography

NASA Astrophysics Data System (ADS)

El Khrepy, Sami; Koulakov, Ivan; Al-Arifi, Nassir; Sychev, Ilya

2017-04-01

Harrat Lunayyir is a relatively young basaltic field in Saudi Arabia located at the western margin of the Arabian Peninsula. In April-June 2009, strong seismic activity and ground deformations at this site marked the activation of the magma system beneath Harrat Lunayyir. In this study, we present new three-dimensional models of the attenuation of P and S waves during the unrest in 2009 based on the analysis of t*. We measured 1658 and 3170 values of t* for P and S waves, respectively, for the same earthquakes that were previously used for travel time tomography. The resulting anomalies of the P and S wave attenuation look very similar. In the center of the study area, we observe a prominent high-attenuation pattern, which coincides with the most active seismicity at shallow depths and maximum ground deformations. This high-attenuation zone may represent a zone of accumulation and ascending of gases, which originated at depths of 5-7 km due to the decompression of ascending liquid volatiles. Based on these findings and previous tomography studies, we propose that the unrest at Harrat Lunayyir in 2009 was triggered by a sudden injection of unstable liquid volatiles from deeper magma sources. At some depths, they were transformed to gases, which caused the volume to increase, and this led to seismic activation in the areas of phase transformations. The overpressurized gases ultimately found the weakest point in the rigid basaltic cover at the junction of several tectonic faults and escaped to the surface.

Adaptation of the length-active tension relationship in rabbit detrusor

PubMed Central

Almasri, Atheer M.; Bhatia, Hersch; Klausner, Adam P.; Ratz, Paul H.

2009-01-01

Studies have shown that the length-tension (L-T) relationships in airway and vascular smooth muscles are dynamic and can adapt to length changes over a period of time. Our prior studies have shown that the passive L-T relationship in rabbit detrusor smooth muscle (DSM) is also dynamic and that DSM exhibits adjustable passive stiffness (APS) characterized by a passive L-T curve that can shift along the length axis as a function of strain history and activation history. The present study demonstrates that the active L-T curve for DSM is also dynamic and that the peak active tension produced at a particular muscle length is a function of both strain and activation history. More specifically, this study reveals that the active L-T relationship, or curve, does not have a unique peak tension value with a single ascending and descending limb, but instead reveals that multiple ascending and descending limbs can be exhibited in the same DSM strip. This study also demonstrates that for DSM strips not stretched far enough to reveal a descending limb, the peak active tension produced by a maximal KCl-induced contraction at a short, passively slack muscle length of 3 mm was reduced by 58.6 ± 4.1% (n = 15) following stretches to and contractions at threefold the original muscle length, 9 mm. Moreover, five subsequent contractions at the short muscle length displayed increasingly greater tension; active tension produced by the sixth contraction was 91.5 ± 9.1% of that produced by the prestretch contraction at that length. Together, these findings indicate for the first time that DSM exhibits length adaptation, similar to vascular and airway smooth muscles. In addition, our findings demonstrate that preconditioning, APS and adaptation of the active L-T curve can each impact the maximum total tension observed at a particular DSM length. PMID:19675182

Volcanism, Iron, and Phytoplankton in the Heard and McDonald Islands Region, Southern Indian Ocean

NASA Astrophysics Data System (ADS)

Coffin, M. F.; Arculus, R. J.; Bowie, A. R.; Chase, Z.; Robertson, R.; Trull, T. W.; Heobi in2016 v01 Shipboard Party, T.

2016-12-01

Phytoplankton supply approximately half of the oxygen in Earth's atmosphere, and iron supply limits the growth of phytoplankton in the anemic Southern Ocean. Situated entirely within the Indian Ocean sector of the Southern Ocean are Australia's only active subaerial volcanoes, Heard and McDonald islands (HIMI) on the central Kerguelen Plateau, a large igneous province. Widespread fields of submarine volcanoes, some of which may be active, extend for distances of up to several hundred kilometers from the islands. The predominantly eastward-flowing Antarctic Circumpolar Current sweeps across the central Kerguelen Plateau, and extensive blooms of phytoplankton are observed on the Plateau down-current of HIMI. The goal of RV Investigator voyage IN2016_V01, conducted in January/February 2016, is to test the hypothesis that hydrothermal fluids, which cool active submarine volcanoes in the HIMI region, ascend from the seafloor and fertilise surface waters with iron, thereby enhancing biological productivity beginning with phytoplankton. Significant initial shipboard results include: Documentation, for the first time, of the role of active HIMI and nearby submarine volcanoes in supplying iron to the Southern Ocean. Nearshore waters had elevated dissolved iron levels. Although biomass was not correspondingly elevated, fluorescence induction data indicated highly productive resident phytoplankton. Discovery of >200 acoustic plumes emanating from the seafloor and ascending up to tens of meters into the water column near HIMI. Deep tow camera footage shows bubbles rising from the seafloor in an acoustic plume field north of Heard Island. Mapping 1,000 km2 of uncharted seafloor around HIMI. Submarine volcanic edifices punctuate the adjacent seafloor, and yielded iron-rich rocks similar to those found on HIMI, respectively. Acoustic plumes emanating from some of these features suggest active seafloor hydrothermal systems.

Molecular regulation of NKCC2 in the thick ascending limb

PubMed Central

Ares, Gustavo R.; Caceres, Paulo S.

2011-01-01

The kidney plays an essential role in blood pressure regulation by controlling short-term and long-term NaCl and water balance. The thick ascending limb of the loop of Henle (TAL) reabsorbs 25–30% of the NaCl filtered by the glomeruli in a process mediated by the apical Na+-K+-2Cl− cotransporter NKCC2, which allows Na+ and Cl− entry from the tubule lumen into TAL cells. In humans, mutations in the gene coding for NKCC2 result in decreased or absent activity characterized by severe salt and volume loss and decreased blood pressure (Bartter syndrome type 1). Opposite to Bartter's syndrome, enhanced NaCl absorption by the TAL is associated with human hypertension and animal models of salt-sensitive hypertension. TAL NaCl reabsorption is subject to exquisite control by hormones like vasopressin, parathyroid, glucagon, and adrenergic agonists (epinephrine and norepinephrine) that stimulate NaCl reabsorption. Atrial natriuretic peptides or autacoids like nitric oxide and prostaglandins inhibit NaCl reabsorption, promoting salt excretion. In general, the mechanism by which hormones control NaCl reabsorption is mediated directly or indirectly by altering the activity of NKCC2 in the TAL. Despite the importance of NKCC2 in renal physiology, the molecular mechanisms by which hormones, autacoids, physical factors, and intracellular ions regulate NKCC2 activity are largely unknown. During the last 5 years, it has become apparent that at least three molecular mechanisms determine NKCC2 activity. As such, membrane trafficking, phosphorylation, and protein-protein interactions have recently been described in TALs and heterologous expression systems as mechanisms that modulate NKCC2 activity. The focus of this review is to summarize recent data regarding NKCC2 regulation and discuss their potential implications in physiological control of TAL function, renal physiology, and blood pressure regulation. PMID:21900458

Effects of distraction on magnetoencephalographic responses ascending through C-fibers in humans.

PubMed

Qiu, Yunhai; Inui, Koji; Wang, Xiaohong; Nguyen, Binh Thi; Tran, Tuan Diep; Kakigi, Ryusuke

2004-03-01

Using magnetoencephalography (MEG), we evaluated the cerebral regions relating to second pain perception ascending through C-fibers and investigated the effect of distraction on each region. Thirteen normal subjects participated in this study. CO2 laser pulses were delivered to the dorsum of the left hand to selectively activate C-fibers. The MEG responses were analyzed using a multi-dipole model. (1) primary somatosensory cortex (SI), and (2) secondary somatosensory cortex (SII)--insula were the main generators for the primary component, 1M, whose mean peak latency was 744 ms. In addition to (1) and (2), (3) cingulate cortex and (4) medial temporal area (MT) were also activated for the subsequent component, 2M, whose mean peak latency was 947 ms. During a mental calculation task (Distraction), all 6 sources were significantly reduced in amplitude, but the SII-insula (P < 0.01) and cingulate cortex (P < 0.001) were more sensitive than the SI (P < 0.05) and MT (P < 0.05). We confirmed that SI in the contralateral hemisphere and SII-insula, cingulate cortex and MT in bilateral hemispheres play a major role in second pain perception, and all sites were much affected by a change of attention, indicating that these regions are related to the cognitive aspect of second pain perception. The SI, SII, cingulate and MT were activated during the C-fiber-related MEG response, and responses in these regions were significantly diminished during mental distraction.

Dynamics and functional model of the 2012-13 flank fissure eruption of Tolbachik volcano in Kamchatka, Russia

NASA Astrophysics Data System (ADS)

Belousov, Alexander; Belousova, Marina; Edwards, Benjamin

2017-04-01

The 2012-13 flank fissure eruption of Tolbachik in Kamchatka Peninsula lasted more than nine months and discharged 0.55 cub.km DRE of basaltic trachyandesite magma. It is one of the most voluminous historical eruptions of mafic magma at subduction-related volcano globally, and is the second largest in Kamchatka. We present a broad overview of the eruption as well as a model for the magma storage and transport system of Plosky Tolbachik Volcano. The 2012-13 eruption was preceded by five months of elevated seismicity and ground inflation, both of which peaked a day before the eruption commenced on 27 November 2012. The batch of high-Al magma ascended from depths of 5-10 km; its apical part contained 54-55 wt.% SiO2, and the main body 52-53 wt.% SiO2. The eruption started by the opening of a 6 km-long radial fissure on the southwestern slope of the volcano that fed multi-vent phreatomagmatic and magmatic explosive activity, as well as intensive effusion of lava with an initial discharge of 440 cub.m/s. After 10 days the eruption continued only at the lower part of the fissure, where explosive and effusive activity of Hawaiian-Strombolian type occurred from a lava pond in the crater of the main growing scoria cone. The discharge rate for the nine month long, effusion-dominated eruption gradually declined from 140 to 18 cub.m/s and formed a compound lava field with a total area of 36 sq.km; the effusive activity evolved from high-discharge channel-fed 'a'a lavas to dominantly low-discharge tube-fed pahoehoe lavas. On 23 August, the effusion of lava ceased and the intra-crater lava pond drained. Weak Strombolian-type explosions continued for several more days on the crater bottom until the end of the eruption around 5 September 2013. The volcanic system, comprising the stratovolcano Plosky Tolbachik and its two radial volcanic rifts, produces alternating eruptions of two genetically related magma types: high-Al basalt (eruptions at the summit and along both rift zones) and high-Mg basalt (eruptions only along the southwest rift). The high-Al magma ascends to the surface from a magma storage zone at a depth of about 5 km below the summit of Plosky Tolbachik. During the 2012-13 eruption the high-Al magma first ascended along the central conduit of the volcano. Then the feeding dyke deviated from the conduit and propagated sub-horizontally along the southwest rift at a depth about 1 km below sea level. The 1975-76 Southern Breakthrough of the volcano was fed in a similar way. In contrast, the 1975-76 Northern Breakthrough of the volcano was fed by vertical dyke of high-Mg magma that ascended to the ground surface from the magma storage zone located directly below the area of the Breakthrough at a depth of approximately 20 km.

Response of the Cardiovascular System to Vibration and Combined Stresses

DTIC Science & Technology

1975-08-31

Canines were chronically instrumented for continuous measurements of ascending aortic flow ( Zepeda ), left ventricular pressure (Konigsberg), circum- flex...different animals. Each dog was chronically instrumented for continuous measuremernt of ascending aortic flow ( Zepeda ), left ventricular pressure...vibration protocol as those animals restrained vertically. METHODS Canines (16 to 22 kg) were chronically instrumented with electromagnetic flow cuffs ( Zepeda

Draft Genome Sequences of Three Escherichia coli Strains with Different In Vivo Pathogenicities in an Avian (Ascending) Infection Model of the Oviduct

PubMed Central

Thøfner, Ida Cecilie Naundrup; Pors, Susanne Elisabeth; Christensen, Henrik; Bisgaard, Magne; Christensen, Jens Peter

2015-01-01

Here, we present three draft genome sequences of Escherichia coli strains that experimentally were proven to possess low (strain D2-2), intermediate (Chronic_salp), or high virulence (Cp6salp3) in an avian (ascending) infection model of the oviduct. PMID:25953185

Analytical Description of Ascending Motion of Rockets in the Atmosphere

ERIC Educational Resources Information Center

Rodrigues, H.; de Pinho, M. O.; Portes, D., Jr.; Santiago, A.

2009-01-01

In continuation of a previous work, we present an analytic study of ascending vertical motion of a rocket subjected to a quadratic drag for the case where the mass-variation law is a linear function of time. We discuss the detailed analytical solution of the model differential equations in closed form. Examples of application are presented and…

Case report of an unusual combination of purulent pericarditis and false aneurysm of the ascending aorta.

PubMed

Meier, David; Kirsch, Matthias; Qanadli, Salah Dine; Muller, Olivier; Fishman, Daniel; Trana, Catalina

2018-01-29

Purulent pericarditis is an uncommon entity, which is, in very rare cases, associated to infection of the aorta. We present the case of a 42-year-old male patient, who was admitted to hospital complaining of tiredness, diarrhea and leg edema. Clinical examination revealed a hypotensive and obviously shocked patient. He was ultimately diagnosed with a rare combination of purulent pericarditis followed by false aneurysm of the ascending aorta. He was successfully treated by surgical pericardial drainage, replacement of the ascending aorta and antibiotics. Mycotic aneurysms can rarely be associated with purulent pericarditis. Our literature review shows that there are two mechanisms explaining this association and that in most of the published cases infective endocarditis could not be demonstrated.

Airborne Laser CO2 Column Measurements: Evaluation of Precision and Accuracy Under a Wide Range of Surface and Atmospheric Conditions

NASA Astrophysics Data System (ADS)

Browell, E. V.; Dobler, J. T.; Kooi, S. A.; Fenn, M. A.; Choi, Y.; Vay, S. A.; Harrison, F. W.; Moore, B.

2011-12-01

This paper discusses the latest flight test results of a multi-frequency intensity-modulated (IM) continuous-wave (CW) laser absorption spectrometer (LAS) that operates near 1.57 μm for remote CO2 column measurements. This IM-LAS system is under development for a future space-based mission to determine the global distribution of regional-scale CO2 sources and sinks, which is the objective of the NASA Active Sensing of CO2 Emissions during Nights, Days, and Seasons (ASCENDS) mission. A prototype of the ASCENDS system, called the Multi-frequency Fiber Laser Lidar (MFLL), has been flight tested in eleven airborne campaigns since May 2005. This paper compares the most recent results obtained during the 2010 and 2011 UC-12 and DC-8 flight tests, where MFLL remote CO2 column measurements were evaluated against airborne in situ CO2 profile measurements traceable to World Meteorological Organization standards. The major change to the MFLL system in 2011 was the implementation of several different IM modes, which could be quickly changed in flight, to directly compare the precision and accuracy of MFLL CO2 measurements in each mode. The different IM modes that were evaluated included "fixed" IM frequencies near 50, 200, and 500 kHz; frequencies changed in short time steps (Stepped); continuously swept frequencies (Swept); and a pseudo noise (PN) code. The Stepped, Swept, and PN modes were generated to evaluate the ability of these IM modes to desensitize MFLL CO2 column measurements to intervening optically thin aerosols/clouds. MFLL was flown on the NASA Langley UC-12 aircraft in May 2011 to evaluate the newly implemented IM modes and their impact on CO2 measurement precision and accuracy, and to determine which IM mode provided the greatest thin cloud rejection (TCR) for the CO2 column measurements. Within the current hardware limitations of the MFLL system, the "fixed" 50 kHz results produced similar SNR values to those found previously. The SNR decreased as expected with increasing IM frequency with the SNR(500 kHz) equal to 31% of SNR(50 kHz). The absolute accuracy of the 50 kHz CO2 measurement showed a previously observed altitude-dependent trend that was greatly reduced at 200 kHz. Laboratory experiments have duplicated this effect which results mainly from IM frequency cross talk between LAS wavelengths in the erbium-doped fiber amplifier (EDFA) and which is reduced when operating at higher IM frequencies. Performance of the Stepped, Swept, and PN modes were evaluated in close time proximity to each other, and these results will be discussed in this paper. A second series of ASCENDS flight tests were conducted on the NASA DC-8 from 25 July to 12 August 2011 over similar local land and ocean targets as in 2010 and with additional long-range flights planned over the corn fields of Iowa, forests in northern Wisconsin, and ice fields of southeastern Alaska. MFLL CO2 measurement results from this field campaign will also be presented.

PSP SAR interferometry monitoring of ground and structure deformations applied to archaeological sites

NASA Astrophysics Data System (ADS)

Costantini, Mario; Francioni, Elena; Trillo, Francesco; Minati, Federico; Margottini, Claudio; Spizzichino, Daniele; Trigila, Alessandro; Iadanza, Carla

2017-04-01

Archaeological sites and cultural heritage are considered as critical assets for the society, representing not only the history of region or a culture, but also contributing to create a common identity of people living in a certain region. In this view, it is becoming more and more urgent to preserve them from climate changes effect and in general from their degradation. These structures are usually just as precious as fragile: remote sensing technology can be useful to monitor these treasures. In this work, we will focus on ground deformation measurements obtained by satellite SAR interferometry and on the methodology adopted and implemented in order to use the results operatively for conservation policies in a Italian archaeological site. The analysis is based on the processing of COSMO-SkyMed Himage data by the e-GEOS proprietary Persistent Scatterer Pair (PSP) SAR interferometry technology. The PSP technique is a proven SAR interferometry technology characterized by the fact of exploiting in the processing only the relative properties between close points (pairs) in order to overcome atmospheric artefacts (which are one of the main problems of SAR interferometry). Validations analyses [Costantini et al. 2015] settled that this technique applied to COSMO-SkyMed Himage data is able to retrieve very dense (except of course on vegetated or cultivated areas) millimetric deformation measurements with sub-metric localization. Considering the limitations of all the interferometric techniques, in particular the fact that the measurement are along the line of sight (LOS) and the geometric distortions, in order to obtain the maximum information from interferometric analysis, both ascending and descending geometry have been used. The ascending analysis allows selecting measurements points over the top and, approximately, South-West part of the structures, while the descending one over the top and the South-East part of the structures. The interferometric techniques needs to use a stack of SAR images to separate the deformation phase contributions from other spurious components (atmospheric, orbital, etc.). Historical/reference analyses of the period 2011-2014 have been performed to obtain such deformations and to have a start point for the next updates. In fact, starting from the reference analyses the deformation monitoring has then continued with monthly updates of the PSP analysis with new COSMO-SkyMed acquisitions both in ascending and descending geometry. In addition to this traditional monitoring service, the satellite interferometry analysis has been realized over specific time frame that have been selected on the bases of some important events (damages to structures, collapses, works etc.) and the analysis have been correlated with additional site information as weather conditions, critical meteorological events, historical information of the site, etc. The objective is to find a nominal behaviour of the site in response to critical events and/or related to natural degradation of infrastructures in order to prevent damages and guide maintenance activities. The first results of this cross correlated analysis showed that some deformation phenomena are identifiable by SAR satellite interferometric analysis and it has also been possible to validate them on field through a direct survey.

Energy from solar balloons

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

Grena, Roberto

2010-04-15

Solar balloons are hot air balloons in which the air is heated directly by the sun, by means of a black absorber. The lift force of a tethered solar balloon can be used to produce energy by activating a generator during the ascending motion of the balloon. The hot air is then discharged when the balloon reaches a predefined maximum height. A preliminary study is presented, along with an efficiency estimation and some considerations on possible realistic configurations. (author)

Supramammillary serotonin reduction alters place learning and concomitant hippocampal, septal, and supramammillar theta activity in a Morris water maze.

PubMed

Hernández-Pérez, J Jesús; Gutiérrez-Guzmán, Blanca E; López-Vázquez, Miguel Á; Olvera-Cortés, María E

2015-01-01

Hippocampal theta activity is related to spatial information processing, and high-frequency theta activity, in particular, has been linked to efficient spatial memory performance. Theta activity is regulated by the synchronizing ascending system (SAS), which includes mesencephalic and diencephalic relays. The supramamillary nucleus (SUMn) is located between the reticularis pontis oralis and the medial septum (MS), in close relation with the posterior hypothalamic nucleus (PHn), all of which are part of this ascending system. It has been proposed that the SUMn plays a role in the modulation of hippocampal theta-frequency; this could occur through direct connections between the SUMn and the hippocampus or through the influence of the SUMn on the MS. Serotonergic raphe neurons prominently innervate the hippocampus and several components of the SAS, including the SUMn. Serotonin desynchronizes hippocampal theta activity, and it has been proposed that serotonin may regulate learning through the modulation of hippocampal synchrony. In agreement with this hypothesis, serotonin depletion in the SUMn/PHn results in deficient spatial learning and alterations in CA1 theta activity-related learning in a Morris water maze. Because it has been reported that SUMn inactivation with lidocaine impairs the consolidation of reference memory, we asked whether changes in hippocampal theta activity related to learning would occur through serotonin depletion in the SUMn, together with deficiencies in memory. We infused 5,7-DHT bilaterally into the SUMn in rats and evaluated place learning in the standard Morris water maze task. Hippocampal (CA1 and dentate gyrus), septal and SUMn EEG were recorded during training of the test. The EEG power in each region and the coherence between the different regions were evaluated. Serotonin depletion in the SUMn induced deficient spatial learning and altered the expression of hippocampal high-frequency theta activity. These results provide evidence in support of a role for serotonin as a modulator of hippocampal learning, acting through changes in the synchronicity evoked in several relays of the SAS.

Rapid and slow: Varying magma ascent rates as a mechanism for Vulcanian explosions

NASA Astrophysics Data System (ADS)

Cassidy, Mike; Cole, Paul. D.; Hicks, Kelby E.; Varley, Nick R.; Peters, Nial; Lerner, Allan H.

2015-06-01

Vulcanian explosions are one of the most common types of volcanic activity observed at silicic volcanoes. Magma ascent rates are often invoked as being the fundamental control on their explosivity, yet this factor is poorly constrained for low magnitude end-member Vulcanian explosions, which are particularly poorly understood, partly due to the rarity of ash samples and low gas fluxes. We describe ash generated by small Vulcanian explosions at Volcán de Colima in 2013, where we document for the first time marked differences in the vesicularity, crystal characteristics (volume fraction, size and shape) and glass compositions in juvenile material from discrete events. We interpret these variations as representing differing ascent styles and speeds of magma pulses within the conduit. Heterogeneous degassing during ascent leads to fast ascending, gas-rich magma pulses together with slow ascending gas-poor magma pulses within the same conduit. This inferred heterogeneity is complemented by SO2 flux data, which show transient episodes of both open and closed system degassing, indicating efficient shallow fracture sealing mechanisms, which allows for gas overpressure to generate small Vulcanian explosions.

Ascending Aortic Dimensions in Former National Football League Athletes.

PubMed

Gentry, James L; Carruthers, David; Joshi, Parag H; Maroules, Christopher D; Ayers, Colby R; de Lemos, James A; Aagaard, Philip; Hachamovitch, Rory; Desai, Milind Y; Roselli, Eric E; Dunn, Reginald E; Alexander, Kezia; Lincoln, Andrew E; Tucker, Andrew M; Phelan, Dermot M

2017-11-01

Ascending aortic dimensions are slightly larger in young competitive athletes compared with sedentary controls, but rarely >40 mm. Whether this finding translates to aortic enlargement in older, former athletes is unknown. This cross-sectional study involved a sample of 206 former National Football League (NFL) athletes compared with 759 male subjects from the DHS-2 (Dallas Heart Study-2; mean age of 57.1 and 53.6 years, respectively, P <0.0001; body surface area of 2.4 and 2.1 m 2 , respectively, P <0.0001). Midascending aortic dimensions were obtained from computed tomographic scans performed as part of a NFL screening protocol or as part of the DHS. Compared with a population-based control group, former NFL athletes had significantly larger ascending aortic diameters (38±5 versus 34±4 mm; P <0.0001). A significantly higher proportion of former NFL athletes had an aorta of >40 mm (29.6% versus 8.6%; P <0.0001). After adjusting for age, race, body surface area, systolic blood pressure, history of hypertension, current smoking, diabetes mellitus, and lipid profile, the former NFL athletes still had significantly larger ascending aortas ( P <0.0001). Former NFL athletes were twice as likely to have an aorta >40 mm after adjusting for the same parameters. Ascending aortic dimensions were significantly larger in a sample of former NFL athletes after adjusting for their size, age, race, and cardiac risk factors. Whether this translates to an increased risk is unknown and requires further evaluation. © 2017 American Heart Association, Inc.

Over length quantification of the multiaxial mechanical properties of the ascending, descending and abdominal aorta using Digital Image Correlation.

PubMed

Peña, Juan A; Corral, Victoria; Martínez, Miguel A; Peña, Estefanía

2018-01-01

In this paper, we hypothesize that the biaxial mechanical properties of the aorta may be dependent on arterial location. To demonstrate any possible position-related difference, our study analyzed and compared the biaxial mechanical properties of the ascending thoracic aorta, descending thoracic aorta and infrarenal abdominal aorta stemming from the same porcine subjects, and reported values of constitutive parameters for well-known strain energy functions, showing how these mechanical properties are affected by location along the aorta. When comparing ascending thoracic aorta, descending thoracic aorta and infrarenal abdominal aorta, abdominal tissues were found to be stiffer and highly anisotropic. We found that the aorta changed from a more isotropic to a more anisotropic tissue and became progressively less compliant and stiffer with the distance to the heart. We observed substantial differences in the anisotropy parameter between aortic samples where abdominal samples were more anisotropic and nonlinear than the thoracic samples. The phenomenological model was not able to capture the passive biaxial properties of each specific porcine aorta over a wide range of biaxial deformations, showing the best prediction root mean square error ε=0.2621 for ascending thoracic samples and, especially, the worst for the infrarenal abdominal samples ε=0.3780. The micro-structured model with Bingham orientation density function was able to better predict biaxial deformations (ε=0.1372 for ascending thoracic aorta samples). The root mean square error of the micro-structural model and the micro-structured model with von Mises orientation density function were similar for all positions. Copyright © 2017 Elsevier Ltd. All rights reserved.

It's Lonely at the Top: Winning Climbing Fibers Ascend Dendrites Solo

PubMed Central

Draft, Ryan W.; Lichtman, Jeff W.

2009-01-01

In mammals, climbing fiber axons compete for sole innervation at each Purkinje cell. At the same time, synapses disappear from Purkinje somata and appear in great numbers on the dendrites. In this issue of Neuron, Hashimoto et al. show that, by the time climbing fibers ascend the dendrites, the winner and losers are already decided. PMID:19607787

Sustainability, Participatory Culture, and the Performance of Democracy: Ascendant Sites of Theory and Practice in Art Education

ERIC Educational Resources Information Center

Blandy, Doug

2011-01-01

Art education is a systemic and extensive network within which children, youth, and adults make and learn about material culture. This lecture considers three sites of theory and practice that I see as ascendant in circulating through this network. These sites are sustainability, participatory culture, and performing democracy. I argue that…

Draft Genome Sequences of Three Escherichia coli Strains with Different In Vivo Pathogenicities in an Avian (Ascending) Infection Model of the Oviduct.

PubMed

Olsen, Rikke Heidemann; Thøfner, Ida Cecilie Naundrup; Pors, Susanne Elisabeth; Christensen, Henrik; Bisgaard, Magne; Christensen, Jens Peter

2015-05-07

Here, we present three draft genome sequences of Escherichia coli strains that experimentally were proven to possess low (strain D2-2), intermediate (Chronic_salp), or high virulence (Cp6salp3) in an avian (ascending) infection model of the oviduct. Copyright © 2015 Olsen et al.

An Exploratory Study of the Ascendancy of Women to the Position of K-12 Superintendent

ERIC Educational Resources Information Center

Hanson, Karen M.

2011-01-01

Despite earning over half of the doctoral degrees in education, women are underrepresented in the position of K-12 superintendent. In 2000, although 72% of all classroom teachers were female, only 14% of all superintendents in the United States were women. Research indicates that women experience barriers in their ascendancy to superintendent.…

Retrograde Ascending Dissection After Thoracic Endovascular Aortic Repair Combined With the Chimney Technique and Successful Open Repair Using the Frozen Elephant Trunk Technique.

PubMed

Hirano, Koji; Tokui, Toshiya; Nakamura, Bun; Inoue, Ryosai; Inagaki, Masahiro; Maze, Yasumi; Kato, Noriyuki

2018-01-01

The chimney technique can be combined with thoracic endovascular aortic repair (TEVAR) to both obtain an appropriate landing zone and maintain blood flow of the arch vessels. However, surgical repair becomes more complicated if retrograde type A aortic dissection occurs after TEVAR with the chimney technique. We herein report a case involving a 73-year-old woman who developed a retrograde ascending dissection 3 months after TEVAR for acute type B aortic dissection. To ensure an adequate proximal sealing distance, the proximal edge of the stent graft was located at the zone 2 level and an additional bare stent was placed at the left subclavian artery (the chimney technique) at the time of TEVAR. Enhanced computed tomography revealed an aortic dissection involving the ascending aorta and aortic arch. Surgical aortic repair using the frozen elephant trunk technique was urgently performed. The patient survived without stroke, paraplegia, renal failure, or other major complications. Retrograde ascending dissection can occur after TEVAR combined with the chimney technique. The frozen elephant trunk technique is useful for surgical repair in such complicated cases.

Laparoscopic resection of adult colon duplication causing intussusception

PubMed Central

Kyo, Kennoki; Azuma, Masaki; Okamoto, Kazuya; Nishiyama, Motohiro; Shimamura, Takahiro; Maema, Atsushi; Shirakawa, Motoaki; Nakamura, Toshio; Koda, Kenji; Yokoyama, Hidetaro

2016-01-01

Gastrointestinal duplications are uncommon congenital malformations that can occur anywhere along the gastrointestinal tract. Most cases are recognized before the age of 2 years, and those encountered in adults are rare. We describe here a case of ascending colon duplication in a 20-year-old male that caused intussusception and was treated laparoscopically. Although computed tomography revealed a cystic mass filled with stool-like material, the preoperative diagnosis was a submucosal tumor of the ascending colon. We performed a laparoscopic right colectomy, and the postoperative pathological diagnosis was duplication of the ascending colon, both cystic and tubular components. We conclude that gastrointestinal duplications, although rare, should be considered in the differential diagnosis of all abdominal and submucosal cystic lesions and that laparoscopy is a preferred approach for the surgical treatment of gastrointestinal duplications. PMID:26900303

Rupture of an ascending and descending thoracic aortic aneurysm causing tension hemothorax: a case report.

PubMed

Pizon, Anthony; Bissell, Brad J; Gilmore, Nathan

2012-10-01

A ruptured thoracic aortic aneurysm is a life-threatening condition and can lead to a tension hemothorax. To describe the presentation and management of a case of a tension hemothorax. An 84-year-old woman presented in respiratory distress and was found to have a tension hemothorax. The cause was the rupture of an ascending and descending thoracic aortic aneurysm. She was managed with intubation, mechanical ventilation, and chest tube placement with stabilization. Definitive operative repair was deferred due to the patient's comorbidities and wishes of the family. A tension hemothorax can result from an ascending and descending thoracic aneurysm, as this case describes. Emergent therapy is necessary as this is a life-threatening condition. Copyright © 2012 Elsevier Inc. All rights reserved.

Ascending Aortic Stenting for Acute Supraaortic Stenosis From Graft Collapse.

PubMed

Lader, Joshua M; Smith, Deane E; Staniloae, Cezar; Fallahi, Arzhang; Iqbal, Sohah N; Galloway, Aubrey C; Williams, Mathew R

2018-06-01

A 78-year-old man with remote type-A dissection presented with acute-onset dyspnea. Twenty-two years prior, treatment for his aortic disease required replacement of ascending and arch aneurysms with a polyester graft (Dacron) using the graft inclusion technique. He presented currently in cardiogenic shock. Echocardiography demonstrated new severe hypokinesis of all apical segments. Left-heart catheterization revealed a 120 mm Hg intragraft gradient. Computed tomography arteriography was unrevealing, but intraaortic ultrasound demonstrated critical intragraft stenosis. A balloon expandable stent (Palmaz stent, Cordis, Milpitas, CA) was deployed in the stenotic region with gradient resolution. The patient later underwent aortic root replacement and ascending aneurysm repair (Bio-Bentall technique) and is doing well at 24 months. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Intrapericardial Denervation: Responses to Water Immersion in Rhesus Monkeys

NASA Technical Reports Server (NTRS)

McKeever, Kenneth H.; Keil, Lanny C.; Sandler, Harold

1995-01-01

Eleven anesthetized rhesus monkeys were used to study cardiovascular, renal, and endocrine alterations associated with 120 min of head-out water immersion. Five animals underwent complete intrapericardial denervation using the Randall technique, while the remaining six monkeys served as intact controls. Each animal was chronically instrumented with an electromagnetic flow probe on the ascending aorta, a strain gauge pressure transducer implanted in the apex of the left ventricle (LV), and electrocardiogram leads anchored to the chest wall and LV. During immersion, LV end-diastolic pressure, urine flow, glomerular filtration rate, sodium excretion, and circulating atrial natriuretic peptide (ANP) each increased (P less than 0.05) for intact and denervated monkeys. There were no alterations in free water clearance in either group during immersion, yet fractional excretion of free water increased (P less than 0.05) in the intact monkeys. Plasma renin activity (PRA) decreased (P less than 0.05) during immersion in intact monkeys but not the denervated animals. Plasma vasopressin (PVP) concentration decreased (P less than 0.05) during the first 30 min of immersion in both groups but was not distinguishable from control by 60 min of immersion in denervated monkeys. These data demonstrate that complete cardiac denervation does not block the rise in plasma ANP or prevent the natriuresis associated with head-out water immersion. The suppression of PVP during the first minutes of immersion after complete cardiac denervation suggests that extracardiac sensing mechanisms associated with the induced fluid shifts may be responsible for the findings.

Central circuitries for body temperature regulation and fever.

PubMed

Nakamura, Kazuhiro

2011-11-01

Body temperature regulation is a fundamental homeostatic function that is governed by the central nervous system in homeothermic animals, including humans. The central thermoregulatory system also functions for host defense from invading pathogens by elevating body core temperature, a response known as fever. Thermoregulation and fever involve a variety of involuntary effector responses, and this review summarizes the current understandings of the central circuitry mechanisms that underlie nonshivering thermogenesis in brown adipose tissue, shivering thermogenesis in skeletal muscles, thermoregulatory cardiac regulation, heat-loss regulation through cutaneous vasomotion, and ACTH release. To defend thermal homeostasis from environmental thermal challenges, feedforward thermosensory information on environmental temperature sensed by skin thermoreceptors ascends through the spinal cord and lateral parabrachial nucleus to the preoptic area (POA). The POA also receives feedback signals from local thermosensitive neurons, as well as pyrogenic signals of prostaglandin E(2) produced in response to infection. These afferent signals are integrated and affect the activity of GABAergic inhibitory projection neurons descending from the POA to the dorsomedial hypothalamus (DMH) or to the rostral medullary raphe region (rMR). Attenuation of the descending inhibition by cooling or pyrogenic signals leads to disinhibition of thermogenic neurons in the DMH and sympathetic and somatic premotor neurons in the rMR, which then drive spinal motor output mechanisms to elicit thermogenesis, tachycardia, and cutaneous vasoconstriction. Warming signals enhance the descending inhibition from the POA to inhibit the motor outputs, resulting in cutaneous vasodilation and inhibited thermogenesis. This central thermoregulatory mechanism also functions for metabolic regulation and stress-induced hyperthermia.

From golden hills to sycamore trees: pastoral homelands and ethnic identity in Irish immigrant fiction, 1860-75.

PubMed

Corporaal, Marguérite

2010-01-01

The prose fiction that remembers the trials of starvation and eviction of the Great Famine (1845-50) often juxtaposes representations of blasted, infertile land with images of a green, idyllic Erin. Through a discussion of Mary Anne Sadlier's Bessy Conway (1861), Elizabeth Hely Walshe's Golden Hills: A Tale of the Irish Famine (1865) and John McElgun's Annie Reilly (1873), this article reveals that immigrant writers of the Famine generation often negotiate depictions of Famine-stricken wasteland with evocations of a pastoral homeland. In the case of the two Catholic novels, Bessy Conway and Annie Reilly, the pastoral becomes a point of ethnic identification through which the immigrants can recollect and reconstruct a sense of Irishness in exile. By contrast, Golden Hills, which focuses on the Anglo-Irish ascendancy, does not lament the mass exodus of afflicted Irish: the novel rather envisions emigration as a way to regenerate Ireland as locus amoenus.

The role of sense of coherence and physical activity in positive and negative affect of Turkish adolescents.

PubMed

Oztekin, Ceyda; Tezer, Esin

2009-01-01

This study investigated the role of sense of coherence and total physical activity in positive and negative affect. Participants were 376 (169 female, 206 male, and 1 missing value) student volunteers from different faculties of Middle East Technical University. Three questionnaires: Sense of Coherence Scale (SOC), Physical Activity Assessment Questionnaire (PAAQ), and Positive and Negative Affect Schedule (PANAS) were administered to the students together with the demographic information sheet. Two separate stepwise multiple linear regression analyses were conducted to examine the predictive power of sense of coherence and total physical activity on positive and negative affect scores. Results revealed that both sense of coherence and total physical activity predicted the positive affect whereas only the sense of coherence predicted the negative affect on university students. Findings are discussed in light of sense of coherence, physical activity, and positive and negative affect literature.

Frontal joint dynamics when initiating stair ascent from a walk versus a stand.

PubMed

Vallabhajosula, Srikant; Yentes, Jennifer M; Stergiou, Nicholas

2012-02-02

Ascending stairs is a challenging activity of daily living for many populations. Frontal plane joint dynamics are critical to understand the mechanisms involved in stair ascension as they contribute to both propulsion and medio-lateral stability. However, previous research is limited to understanding these dynamics while initiating stair ascent from a stand. We investigated if initiating stair ascent from a walk with a comfortable self-selected speed could affect the frontal plane lower-extremity joint moments and powers as compared to initiating stair ascent from a stand and if this difference would exist at consecutive ipsilateral steps on the stairs. Kinematics data using a 3-D motion capture system and kinetics data using two force platforms on the first and third stair treads were recorded simultaneously as ten healthy young adults ascended a custom-built staircase. Data were collected from two starting conditions of stair ascent, from a walk (speed: 1.42 ± 0.21 m/s) and from a stand. Results showed that subjects generated greater peak knee abductor moment and greater peak hip abductor moment when initiating stair ascent from a walk. Greater peak joint moments and powers at all joints were also seen while ascending the second ipsilateral step. Particularly, greater peak hip abductor moment was needed to avoid contact of the contralateral limb with the intermediate step by counteracting the pelvic drop on the contralateral side. This could be important for therapists using stair climbing as a testing/training tool to evaluate hip strength in individuals with documented frontal plane abnormalities (i.e. knee and hip osteoarthritis, ACL injury). Copyright © 2011 Elsevier Ltd. All rights reserved.

Active touch sensing

PubMed Central

Prescott, Tony J.; Diamond, Mathew E.; Wing, Alan M.

2011-01-01

Active sensing systems are purposive and information-seeking sensory systems. Active sensing usually entails sensor movement, but more fundamentally, it involves control of the sensor apparatus, in whatever manner best suits the task, so as to maximize information gain. In animals, active sensing is perhaps most evident in the modality of touch. In this theme issue, we look at active touch across a broad range of species from insects, terrestrial and marine mammals, through to humans. In addition to analysing natural touch, we also consider how engineering is beginning to exploit physical analogues of these biological systems so as to endow robots with rich tactile sensing capabilities. The different contributions show not only the varieties of active touch—antennae, whiskers and fingertips—but also their commonalities. They explore how active touch sensing has evolved in different animal lineages, how it serves to provide rapid and reliable cues for controlling ongoing behaviour, and even how it can disintegrate when our brains begin to fail. They demonstrate that research on active touch offers a means both to understand this essential and primary sensory modality, and to investigate how animals, including man, combine movement with sensing so as to make sense of, and act effectively in, the world. PMID:21969680

Mid-term results of zone 0 thoracic endovascular aneurysm repair after ascending aorta wrapping and supra-aortic debranching in high-risk patients.

PubMed

Pecoraro, Felice; Lachat, Mario; Hofmann, Michael; Cayne, Neal S; Chaykovska, Lyubov; Rancic, Zoran; Puippe, Gilbert; Pfammatter, Thomas; Mangialardi, Nicola; Veith, Frank J; Bettex, Dominique; Maisano, Francesco; Neff, Thomas A

2017-06-01

Surgical repair of aneurysmal disease involving the ascending aorta, aortic arch and eventually the descending aorta is generally associated with significant morbidity and mortality. A less invasive approach with the ascending wrapping technique (WT), supra-aortic vessel debranching (SADB) and thoracic endovascular aneurysm repair (TEVAR) in zone 0 was developed to reduce the associated risk in these patients. During a 10-year period, consecutive patients treated by the ascending WT, SADB and TEVAR in zone 0 were included. All patients were considered at high risk for conventional surgery. Measured outcomes included perioperative deaths and morbidity, maximal aortic transverse diameter (TD) and its postoperative evolution, endoleak, survival, freedom from cardiovascular reinterventions, SADB freedom from occlusion and aortic valve function during follow-up. Median follow-up was 37.4 [mean = 34; range, 0-65; standard deviation (SD) = 20] months. Twenty-six cases were included with a mean age of 71.88 ( r  = 56-87; SD = 8) years. A mean of 2.9 supra-aortic vessels (75) per patient was debranched from the ascending aorta. The mean time interval from WT/SADB and TEVAR was 29 ( r  = 0-204; SD = 48) days. TEVAR was associated with chimney and/or periscope grafts in 6 (23%) patients, and extra-anatomical supra-aortic bypasses were performed in 6 (23%) patients. Perioperative mortality was 7.7% (2/26). Neurological events were registered in 3 (11.5%) cases, and a reintervention was required in 3 (11.5%) cases. After the WT, the ascending diameter remained stable during the follow-up period in all cases. At mean follow-up, significant shrinkage of the arch/descending aorta diameter was observed. A type I/III endoleak occurred in 3 cases. At 5 years, the rates of survival, freedom from cardiovascular reinterventions and SADB freedom from occlusion were 71.7, 82.3 and 96%, respectively. The use of the ascending WT, SADB and TEVAR in selected patients with complex thoracic aorta disease is safe and shows promising mid-term results at 3 years. The combination of these techniques could represent an alternative to the standard open surgical repair, especially in older patients or in patients unfit for cardiopulmonary bypass. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Tropical Forest Backscatter Anomaly Evident in SeaWinds Scatterometer Morning Overpass Data During 2005 Drought in Amazonia

NASA Astrophysics Data System (ADS)

Frolking, S. E.; Milliman, T.; Palace, M. W.; Wisser, D.; Lammers, R. B.; Fahnestock, M. A.

2010-12-01

A severe drought occurred in many portions of Amazonia in the dry season (June-September) of 2005. We analyzed ten years (7/99-10/09) of SeaWinds active microwave Ku-band backscatter data collected over the Amazon Basin, developing a monthly climatology and monthly anomalies from that climatology in an effort to detect landscape responses to this drought. We compared these to seasonal accumulating water deficit anomalies generated using Tropical Rainfall Monitoring Mission (TRMM) precipitation data (1999-2009) and 100 mm/mo evapotranspirative demand as a water deficit threshold. There was significant interannual variability in monthly mean backscatter only for ascending (early morning) overpass data, and little interannual variability in monthly mean backscatter for descending (late afternoon) overpass data. Strong negative anomalies in both ascending-overpass backscatter and accumulating water deficit developed during July-October 2005, centered on the southwestern Amazon Basin (Acre and western Amazonas states in Brazil; Madre de Dios state in Peru; Pando state in Bolivia). During the 2005 drought, there was a strong spatial correlation between morning overpass backscatter anomalies and water deficit anomalies. We hypothesize that as the drought persisted over several months, the forest canopy was increasingly unable to recover full leaf moisture content over night, and the early morning overpass backscatter data became anomalously low. This is the first reporting of tropical wet forest seasonal drought detection by active microwave scatterometry.

Dose-dependent acute liver injury with hypersensitivity features in humans due to a novel microsomal prostaglandin E synthase 1 inhibitor.

PubMed

Jin, Yan; Regev, Arie; Kam, Jeanelle; Phipps, Krista; Smith, Claire; Henck, Judith; Campanale, Kristina; Hu, Leijun; Hall, D Greg; Yang, Xiao Yan; Nakano, Masako; McNearney, Terry Ann; Uetrecht, Jack; Landschulz, William

2018-01-01

LY3031207, a novel microsomal prostaglandin E synthase 1 inhibitor, was evaluated in a multiple ascending dose study after nonclinical toxicology studies and a single ascending dose study demonstrated an acceptable toxicity, safety and tolerability profile. Healthy subjects were randomized to receive LY3031207 (25, 75 and 275 mg), placebo or celecoxib (400 mg) once daily for 28 days. The safety, tolerability and pharmacokinetic and pharmacodynamic profiles of LY3031207 were evaluated. The study was terminated when two subjects experienced drug-induced liver injury (DILI) after they had received 225 mg LY3031207 for 19 days. Liver biopsy from these subjects revealed acute liver injury with eosinophilic infiltration. Four additional DILI cases were identified after LY3031207 dosing had been stopped. All six DILI cases shared unique presentations of hepatocellular injury with hypersensitivity features and demonstrated a steep dose-dependent trend. Prompt discontinuation of the study drug and supportive medical care resulted in full recovery. Metabolites from metabolic activation of the imidazole ring were observed in plasma and urine samples from all subjects randomized to LY3031207 dosing. This study emphasized the importance of careful safety monitoring and serious adverse events management in phase I trials. Metabolic activation of the imidazole ring may be involved in the development of hepatotoxicity of LY3031207. © 2017 The British Pharmacological Society.

The dynamics of slug trains in volcanic conduits: Evidence for expansion driven slug coalescence

NASA Astrophysics Data System (ADS)

Pering, T. D.; McGonigle, A. J. S.; James, M. R.; Capponi, A.; Lane, S. J.; Tamburello, G.; Aiuppa, A.

2017-12-01

Strombolian volcanism is a ubiquitous form of activity, driven by the ascent and bursting of bubbles of slug morphology. Whilst considerable attention has been devoted to understanding the behaviour of individual slugs in this regime, relatively little is known about how inter-slug interactions modify flow conditions. Recently, we reported on high temporal frequency strombolian activity on Etna, in which the larger erupted slug masses were followed by longer intervals before the following explosion than the smaller bursts (Pering et al., 2015). We hypothesised that this behaviour arose from the coalescence of ascending slugs causing a prolonged lag before arrival of the next distinct bubble. Here we consider the potential importance of inter-slug interactions for the dynamics of strombolian volcanism, by reporting on the first study into the behaviour of trains of ascending gas slugs, scaled to the expansion rates in volcanic conduits. This laboratory analogue study illustrates that slugs in trains rise faster than individual slugs, and can be associated with aspects of co-current flow. The work also highlights that coalescence and inter-slug interactions play an important role in modulating slug train behaviour. We also report, for the first time, on slug coalescence driven by vertical expansion of the trailing slug, a process which can occur, even where the leading slug base ascent velocity is greater than that of the trailing slug.

Technology study of quantum remote sensing imaging

NASA Astrophysics Data System (ADS)

Bi, Siwen; Lin, Xuling; Yang, Song; Wu, Zhiqiang

2016-02-01

According to remote sensing science and technology development and application requirements, quantum remote sensing is proposed. First on the background of quantum remote sensing, quantum remote sensing theory, information mechanism, imaging experiments and prototype principle prototype research situation, related research at home and abroad are briefly introduced. Then we expounds compress operator of the quantum remote sensing radiation field and the basic principles of single-mode compression operator, quantum quantum light field of remote sensing image compression experiment preparation and optical imaging, the quantum remote sensing imaging principle prototype, Quantum remote sensing spaceborne active imaging technology is brought forward, mainly including quantum remote sensing spaceborne active imaging system composition and working principle, preparation and injection compression light active imaging device and quantum noise amplification device. Finally, the summary of quantum remote sensing research in the past 15 years work and future development are introduced.

Pulsed 2-micron Laser Transmitter For Carbon Dioxide Sensing From Space

NASA Astrophysics Data System (ADS)

Singh, U. N.; Yu, J.; Bai, Y.; Petros, M.

2011-12-01

Carbon dioxide (CO2) has been recognized as one of the most important greenhouse gases. It is essential for the study of global warming to accurately measure the CO2 concentration in the atmosphere and continuously record its variation. Studies of the carbon cycle are limited by the tools available to precisely measure CO2 concentrations by remote sensing. Active sensing, using the Integrated Path Differential Absorption (IPDA) approach, permits measurements day and night, at all latitudes and seasons. The development of a high pulse energy 2-μm laser transmitter for high-precision CO2 measurements from space leverages years of NASA investment in solid-state laser technology. Under NASA Laser Risk Reduction Program, funded by Earth Science Technology Office, researchers at NASA Langley Research Center developed an injection seeded, high repetition rate, Q-switched Ho:YLF laser transmitter for CO2 Differential Absorption Lidar/IPDA (profile/column) measurements from ground and airborne platforms. This master-slave laser system has high optical-to-optical efficiency and seeding success rate. NASA LaRC's 2-micron pulsed laser transmitter possesses advantages over current passive and CW active sensors. First, the pulsed format provides a built-in means for determining range to the scattering target and effectively filtering out the scattering from thin clouds and aerosols, thus eliminating a source of measurement bias. Second, by concentrating the laser energy into a pulse, sufficient backscatter signal strength can be obtained from aerosol scattering rather than relying on a hard target at a known distance. Third, the absorption line at the 2.05 μm band is ideally suited for the CO2 concentration measurement. In particular, the weighting function of 2 μm is optimum for measurement in the lower troposphere where the sources and sinks of CO2 are located. The planned laser transmitter development will lead to a Tm:Fiber pumped Ho:YLF laser transmitter capable of delivering 65 mJ at 50 Hz at on-line wavelength and 50 mJ at 50 Hz at off-line wavelength. The planned laser technology development and performance capabilities are a major step forward in the laser transmitter requirements called out in recent comprehensive system studies, e.g., the European Space Agency (ESA) exploration mission studies, A-SCOPE, for future CO2 column density measurements from space. The planned laser technology development is relevant to NASA's earth science priorities, such as NASA ASCENDS mission for space-based CO2 column density measurements. This presentation will provide an overview of the current status of laser transmitter development and describe future technology development to meet the transmitter requirement for a space-based column averaged measurement of CO2 concentration.

Perforated Solitary Diverticulitis of the Ascending Colon

DTIC Science & Technology

2005-06-01

postoperative day 6. DISCUSSION Diverticuli of the right colon exist in approximately 1% to 5% of patients with diverticular disease .1-3 They are...ORIGINAL REPORTS Perforated Solitary Diverticulitis of the Ascending Colon CPT David S. Kauvar, MC, USA, MAJ, Jayson Aydelotte, MC, USA, and MAJ...Michael Harnisch, MC, USA Department of Surgery, Brooke Army Medical Center, Fort Sam Houston, Texas KEY WORDS: solitary colon diverticulum

Source of solutes to the coastal sabkha of Abu Dhabi

USGS Publications Warehouse

Wood, W.W.; Sanford, W.E.; Al Habshi, A.R.S.

2002-01-01

An ascending-brine model is proposed to address the observed isotope geochemistry, solute composition, and solute and water fluxes in the coastal sabkha of the Emirate of Abu Dhabi. Mass-balance measurements document that >95% of the solutes are derived from ascending continental brines; minor amounts are derived from rainfall and from groundwater entering from upgradient areas. Nearly 100% of the annual water loss is from evaporation and not lateral discharge. Direct rainfall on the sabkha and subsequent recharge to the underlying aquifer account for ~ 90% of the annual water input to the system; the remaining 10% comes from both lateral and ascending groundwater flow. Thus, the water and solutes in this system are from different sources. Solute concentrations of conservative (i.e., nonreactive) elements in the coastal, sabkha-covered aquifer are consistent with the fluid pore volumes of ascending brine calculated from hydrologic properties. Calcium to sulfate ratios and sulfur isotopes are consistent with this source of solute from the underlying Tertiary formations. Recharging rainwater dissolves halite and other soluble minerals on the surface, causing the solution to become more dense and sink to the bottom of the aquifer where it vertically mixes with less dense ascending brines. Solutes are returned to the surface by capillary forces and recycled or lost from the system by eolian or fluvial processes. Thus, the system becomes vertically mixed, consistent with the presence of tritium throughout the aquifer; but there is essentially no horizontal mixing of seawater with groundwater. The observed seawater solutes in the supratidal zone come from interstitial seawater trapped by the rapid progradation of the sediments into the Arabian Gulf and are not refluxed or laterally mixed. The ascending-brine model contrasts significantly with both the seawater-flooding and evaporative-pumping models previously proposed as a source of solutes to the coastal sabkha of the Emirate of Abu Dhabi. Use of these earlier models leads to incorrect conclusions and raises serious questions about their applicability in the evaluation of sabkhat in the geologic record.

Electromyographic Comparison of Squats Using Constant or Variable Resistance.

PubMed

Andersen, Vidar; Steiro Fimland, Marius; Knutson Kolnes, Maria; Jensen, Susanne; Laume, Martine; Hole Saeterbakken, Atle

2016-12-01

Andersen, V, Fimland, MS, Kolnes, MK, Jensen, S, Laume, M and Saeterbakken, AH. Electromyographic comparison of squats using constant or variable resistance. J Strength Cond Res 30(12): 3456-3463, 2016-The aim of the study was to compare the electromyographic (EMG) activity of vastus lateralis, vastus medialis, rectus femoris, and biceps femoris when performing the squat with constant resistance or variable resistance with 2 or 4 elastic bands, respectively, contributing with a mean of 39 and 73% of the total loads. Nineteen resistance-trained women performed 6 repetition maximum using 3 different experimental conditions: free weights (FW), free weights + 2 elastic bands (FW + 2EB), and free weights + 4 elastic bands (FW + 4EB). During analyses, each repetition was divided into 6 phases: upper (more extended knee), middle, and lower phase of the descending and ascending movements. Increased activation in the upper parts of the movement was observed for both variable resistance conditions compared with constant resistance (9-51%, p < 0.001-0.050). Further, a dose-response effect of variable resistance was observed in the upper ascending movement, with 4 elastic bands increasing muscle activation more than 2 elastic bands (7-28%, p = 0.003-0.007). For the whole movement, a 12% higher activation of the biceps femoris was observed for FW + 4EB compared with FW (p = 0.005). There were no differences between the other conditions in any of the muscles (p = 0.077-1.000). In conclusion, performing the squat using free weights in combination with elastic bands seems to be preferable compared with free weights alone and more so with a high contribution from variable resistance to the total load.

Concomitant replacement of the dilated ascending aorta during aortic valve replacement; does it increase the perioperative morbidity and mortality risks?

PubMed

Lim, Ju Y; Jung, Sung H; Kim, Joon B; Kim, Dong K; Chung, Cheol H; Song, Hyun; Lee, Jae W; Choo, Suk J

2013-05-01

Concerns of increased surgical risks with ascending aortic replacement have led surgeons to manage post-stenotic aortic dilatation more conservatively during aortic valve replacement (AVR). The present study aimed to assess the prognostic implications and surgical risks of replacing the dilated aorta during AVR. Between January 1999 and March 2010, 134 patients who received surgery for aortic stenosis and post-stenotic dilatation (aorta size ≥40 mm) were included in the present study. AVR was performed in 92 patients (AVR group) while aortic valve and ascending aorta replacement (AVR + aorta group) were performed in 42 patients. Overall survival was compared between the two groups using Cox proportional hazard model after adjustment with inverse-probability-of-treatment weighting. The mean follow-up duration was 3.5 ± 3 years. There were no significant differences in the operative mortality and morbidity between the two groups. The late cardiac deaths were also not significantly different between the two groups (p = 1.00). In the AVR group, the ascending aortic expansion rate which was 0.18 mm/year over a mean follow-up duration of 2.3 ± 2.2 years by echocardiography showed a positive correlation with time (r = 0.3, p = 0.08). A relatively greater aortic expansion rate was identified as a risk factor for late mortality (p = 0.015, HR 1.08 (CI: 1.02 to 1.15). Concomitant replacement of the dilated ascending aorta during AVR did not increase the immediate postoperative morbidity or mortality risks and tended to exert a long-term beneficial effect on the risk of late mortality. © 2013 Wiley Periodicals, Inc.

[Simultaneous interventions on the ascending portion, arch of the aorta and cardiac valves in patients with Marfan's syndrome].

PubMed

Belov, Iu V; Stepanenko, A B; Gens, A P; Charchian, E R; Savichev, D D

2007-01-01

Simultaneous surgical interventions on the aorta and valvular system of the heart were performed in four patients presenting with aortic dissections and aneurysms conditioned by Marfan's syndrome. The following reconstructive operations were carried out: 1) prosthetic repair of the aortic valve and the ascending portion of the aorta by means of a valve-containing conduit with replantation of the openings of the coronary arteries into the side of the prosthesis according to the Benthall - De Bono technique, annuloplasty of the tricuspid valve according to the De Vega technique, valvuloplasty of the mitral valve by the Alferi technique; 2) grafting of the aortic valve and the ascending portion of the aorta by means of a valve-containing conduit with replantation of the openings of the coronary arteries according to the Kabrol's technique, plasty of the tricuspid valve by the De Vega technique; 3) prosthetic repair of the aortic arch with distal wedge-like excision of the membrane of the dissection and directing the blood flow along the both channels, plasty of the mitral valve, plasty of the aortic valve and the ascending portion of the aorta with a valve-containing conduit, accompanied by replantation of the openings of the coronary arteries into the side of the graft according to the Benthall - De Bono technique; (4) plasty of the mitral valve with a disk graft through the fibrous ring of the aortic valve, prosthetic repair of the aortic valve and the ascending portion of the aorta with a valve-containing conduit, accompanied by replantation of the openings of the coronary arteries into the side according to the Benthall-De Bono technique.

Modelling atherosclerosis by proteomics: Molecular changes in the ascending aortas of cholesterol-fed rabbits.

PubMed

Xu, Jingshu; Jüllig, Mia; Middleditch, Martin J; Cooper, Garth J S

2015-09-01

The cholesterol-fed rabbit is commonly used as a model to study the vascular effects of hypercholesterolemia and resulting atherosclerotic lesions. Here we undertook a proteomic case-control investigation of ascending aortas from male New Zealand White rabbits after 10 weeks on a high-cholesterol (2% w/w) diet (HCD, n = 5) or control diet (n = 5), in order to determine the changes in response to the HCD. Histology confirmed intimal thickening in the HCD group consistent with atherosclerosis, and LC-MS/MS analysis of individually-obtained ascending aortic extracts labelled with isobaric (iTRAQ) tags enabled the identification and quantitation of 453 unique proteins above the 1% false discovery rate threshold. Of 67 proteins showing significant differences in relative abundance (p < 0.05), 62 were elevated and five decreased in ascending aortas from HCD-fed rabbits compared to controls. Six proteins were selected for validation using Multiple Reaction Monitoring, which confirmed the iTRAQ results. Many of the observed protein changes are consistent with known molecular perturbations in the ascending aorta that occur in response to hypercholesterolemia, e.g. elevation of tissue levels of apolipoproteins, extracellular matrix adhesion proteins, glycolytic enzymes, heat shock proteins and proteins involved in immune defense. We also made a number of novel observations, including a 15-fold elevation of glycoprotein (trans-membrane) nmb-like (Gpnmb) in response to HCD. Gpnmb has previously been linked to angiogenesis but not to atherosclerosis. This and additional novel observations merit further investigation as these perturbations may play important and as yet undiscovered roles in the pathogenesis of atherosclerosis in rabbits as well as humans. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Advanced atherosclerosis is associated with increased medial degeneration in sporadic ascending aortic aneurysms.

PubMed

Albini, Paul T; Segura, Ana Maria; Liu, Guanghui; Minard, Charles G; Coselli, Joseph S; Milewicz, Dianna M; Shen, Ying H; LeMaire, Scott A

2014-02-01

The pathogenesis of non-familial, sporadic ascending aortic aneurysms (SAAA) is poorly understood, and the relationship between ascending aortic atherosclerosis and medial degeneration is unclear. We evaluated the prevalence and severity of aortic atherosclerosis and its association with medial degeneration in SAAA. Atherosclerosis was characterized in ascending aortic tissues collected from 68 SAAA patients (mean age, 62.9 ± 12.0 years) and 15 controls (mean age, 56.6 ± 11.4 years [P = 0.07]) by using a modified American Heart Association classification system. Upon histologic examination, 97% of SAAA patients and 73% of controls showed atherosclerotic changes. Most SAAA samples had intermediate (types 2 and 3, 35%) or advanced atherosclerosis (types ≥ 4; 40%), whereas most control samples showed minimal atherosclerosis (none or type 1, 80%; P < 0.001 after adjusting for age). In a separate analysis, we examined the total incidence and grade distribution of medial degenerative changes among SAAA samples according to atherosclerosis grade. Advanced atherosclerosis was associated with higher grades of smooth muscle cell depletion (P < 0.001), elastic fiber depletion (P = 0.02), elastic fiber fragmentation (P < 0.001), and mucopolysaccharide accumulation (P = 0.04). Aortic diameter was larger in SAAA patients with advanced atherosclerosis than in patients with minimal (P = 0.04) or intermediate atherosclerosis (P = 0.04). Immunostaining showed marked CD3+ T-cell and CD68+ macrophage infiltration, MMP-2 and MMP-9 production, and cryopyrin expression in the medial layer adjacent to atherosclerotic plaque. SAAA tissues exhibited advanced atherosclerosis that was associated with severe medial degeneration and increased aortic diameter. Our findings suggest a role for atherosclerosis in the progression of sporadic ascending aortic aneurysms. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

The complementary role of magnetic resonance imaging, Doppler echocardiography, and computed tomography in the diagnosis of dissecting thoracic aneurysms.

PubMed

Goldman, A P; Kotler, M N; Scanlon, M H; Ostrum, B; Parameswaran, R; Parry, W R

1986-05-01

Non-ECG gated MRI was compared with 2DE and/or CT scans in 10 patients with dissecting aneurysms proven by angiography and/or surgery. Patient ages ranged from 48 to 85 years (mean 69.6). Six had DeBakey type I dissections and four had DeBakey type III dissections. MRI was diagnostic for aortic dissection in nine cases and suggestive in the tenth. 2DE was diagnostic in six out of nine patients, suggestive in two patients, and nondiagnostic in one patient. CT was diagnostic in the three cases in which it was employed. MRI demonstrated a dilated ascending aorta with thickened walls in all type I dissections as well as an intimal flap and slow flow in the false channel in four patients. In the other two patients with type I dissection, MRI detected the intimal flap in the descending aorta but not in the ascending aorta, whereas 2DE revealed the ascending aortic intimal flap in both of these patients and CT showed it in one of them. In the type III dissections, MRI demonstrated a thickened wall and thrombus in the lumen in all four cases, and the intimal flap in three out of the four. 2DE excluded ascending aortic involvement in all three type III dissections. Six other patients with fusiform dilated ascending aortas had no evidence of dissection by MRI, 2DE, and aortography. Thus, non-ECG gated MRI alone or in combination with 2DE and/or CT is useful in the diagnosis of dissecting thoracic aneurysm and in assessing the extent of the dissection. In addition, the differentiation of dissecting aneurysms of the aorta from fusiform dilatation of the aorta is made possible by these noninvasive techniques.

Percutaneous valved stent implantation in the ascending aorta for the treatment of very high-risk aortic regurgitation: an animal study.

PubMed

Zong, Gang-Jun; Jiang, Hai-Bin; Bai, Yuan; Wu, Gang-Yong; Ye, Guang-Ming; Chen, Jing-Kai; Qin, Yong-Wen; Zhao, Xian-xian

2013-12-01

We investigated the effects of percutaneous valved stent implantation in the ascending aorta as an alternative treatment for aortic regurgitation in a canine model. A total of 16 healthy dogs weighing an average of 18.3 ± 2.1 kg were used for the establishment of animal models of chronic aortic regurgitation by percutaneous aortic valve perforation and balloon dilation. At 2 mo after successful model establishment, all experimental animals underwent valved stent implantation in the ascending aorta and then were followed up for 3 mo. Experimental models of chronic aortic regurgitation were successfully established in 10 dogs. Surviving dogs underwent successful valved stent implantation in the ascending aorta and were subsequently followed up for 3 mo. The level of instantaneous aortic regurgitation at 3-mo follow-up was significantly reduced compared with that before valved stent implantation (2.4 ± 0.9 versus 10.6 ± 2.1 mL/s, P < 0.05). The left ventricular ejection fraction was significantly increased (53.8 ± 4.2% versus 37.8 ± 3.7%, P < 0.05), and the left ventricular end-diastolic volume was also significantly reduced (30.3 ± 2.2 versus 40.1 ± 3.6 mL, P < 0.05). No paravalvular leak, stroke, atrioventricular block, or other complications occurred in dogs undergoing valved stent implantation. Percutaneous valved stent implantation in the ascending aorta is feasible, effective, and safe as an alternative treatment for very high-risk aortic regurgitation in a canine model. Copyright © 2013 Elsevier Inc. All rights reserved.

Patterns in the knee flexion-extension moment profile during stair ascent and descent in patients with total knee arthroplasty.

PubMed

McClelland, Jodie A; Feller, Julian A; Menz, Hylton B; Webster, Kate E

2014-06-03

The aim of this study was to investigate the prevalence of abnormal knee biomechanical patterns in 40 patients with a modern TKA prosthesis, compared to 40 matched control participants when ascending and descending stairs. Fewer patients were able to ascend (65%) or descend stairs (53%) unassisted than controls (83%). Of the participants who could ascend and descend, cluster analysis classified most patients (up to 77%) as demonstrating a similar knee moment pattern as all controls. A small subgroup of patients who completed the tasks did so with distinctly abnormal biomechanics compared to other patients and controls. These findings suggest that recovery of normal stair climbing is possible. However, rehabilitation might be more effective if it were tailored to account for these differences between patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

Geodesic Distance Algorithm for Extracting the Ascending Aorta from 3D CT Images

PubMed Central

Jang, Yeonggul; Jung, Ho Yub; Hong, Youngtaek; Cho, Iksung; Shim, Hackjoon; Chang, Hyuk-Jae

2016-01-01

This paper presents a method for the automatic 3D segmentation of the ascending aorta from coronary computed tomography angiography (CCTA). The segmentation is performed in three steps. First, the initial seed points are selected by minimizing a newly proposed energy function across the Hough circles. Second, the ascending aorta is segmented by geodesic distance transformation. Third, the seed points are effectively transferred through the next axial slice by a novel transfer function. Experiments are performed using a database composed of 10 patients' CCTA images. For the experiment, the ground truths are annotated manually on the axial image slices by a medical expert. A comparative evaluation with state-of-the-art commercial aorta segmentation algorithms shows that our approach is computationally more efficient and accurate under the DSC (Dice Similarity Coefficient) measurements. PMID:26904151

Ascending control of arousal and motivation: role of nucleus incertus and its peptide neuromodulators in behavioural responses to stress.

PubMed

Ma, S; Gundlach, A L

2015-06-01

Arousal is a process that involves the activation of ascending neural pathways originating in the rostral pons that project to the forebrain through the midbrain reticular formation to promote the activation of key cortical, thalamic, hypothalamic and limbic centres. Established modulators of arousal include the cholinergic, serotonergic, noradrenergic and dopaminergic networks originating in the pons and midbrain. Recent data indicate that a population of largely GABAergic projection neurones located in the nucleus incertus (NI) are also involved in arousal and motivational processes. The NI has prominent efferent connections with distinct hypothalamic, amygdalar and thalamic nuclei, in addition to dense projections to key brain regions associated with the generation and pacing of hippocampal activity. The NI receives strong inputs from the prefrontal cortex, lateral habenula and the interpeduncular and median raphe nuclei, suggesting it is highly integrated in circuits regulating higher cognitive behaviours (hippocampal theta rhythm) and emotion. Anatomical and functional studies have revealed that the NI is a rich source of multiple peptide neuromodulators, including relaxin-3, and may mediate extra-hypothalamic effects of the stress hormone corticotrophin-releasing factor, as well as other key modulators such as orexins and oxytocin. This review provides an overview of earlier studies and highlights more recent research that implicates this neural network in the integration of arousal and motivated behaviours and has begun to identify the associated mechanisms. Future research that should help to better clarify the connectivity and function of the NI in major experimental species and humans is also discussed. © 2015 British Society for Neuroendocrinology.

Trunk and lower limb biomechanics during stair climbing in people with and without symptomatic femoroacetabular impingement.

PubMed

Hammond, Connor A; Hatfield, Gillian L; Gilbart, Michael K; Garland, S Jayne; Hunt, Michael A

2017-02-01

Femoroacetabular impingement is a pathomechanical hip condition leading to pain and impaired physical function. It has been shown that those with femoroacetabular impingement exhibit altered gait characteristics during level walking and stair climbing, and decreased muscle force production during isometric muscle contractions. However, no studies to-date have looked at trunk kinematics or muscle activation during dynamic movements such as stair climbing in this patient population. The purpose of this study was to compare biomechanical outcomes (trunk and lower limb kinematics as well as lower limb kinetics and muscle activation) during stair climbing in those with and without symptomatic femoroacetabular impingement. Trunk, hip, knee and ankle kinematics, as well as hip, knee and ankle kinetics and muscle activity of nine lower limb muscles were collected during stair climbing for 20 people with clinical and radiographic femoroacetabular impingement and compared to 20 age- and sex-matched pain-free individuals. Those with femoroacetabular impingement ascended the stairs slower (effect size=0.82), had significantly increased peak trunk forward flexion angles (effect size=0.99) and external hip flexion moments (effect size=0.94) and had decreased peak external knee flexion moments (effect size=0.90) compared to the control group. Findings from this study indicate that while those with and without femoroacetabular impingement exhibit many biomechanical similarities when ascending stairs, differences in trunk forward flexion and joint kinetics indicate some important differences. Further longitudinal research is required to elucidate the cause of these differences as well as the clinical relevance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Connectivity of Pacemaker Neurons in the Neonatal Rat Superficial Dorsal Horn

PubMed Central

Ford, Neil C.; Arbabi, Shahriar; Baccei, Mark L.

2014-01-01

Pacemaker neurons with an intrinsic ability to generate rhythmic burst-firing have been characterized in lamina I of the neonatal spinal cord, where they are innervated by high-threshold sensory afferents. However, little is known about the output of these pacemakers, as the neuronal populations which are targeted by pacemaker axons have yet to be identified. The present study combines patch clamp recordings in the intact neonatal rat spinal cord with tract-tracing to demonstrate that lamina I pacemaker neurons contact multiple spinal motor pathways during early life. Retrograde labeling of premotor interneurons with the trans-synaptic virus PRV-152 revealed the presence of burst-firing in PRV-infected lamina I neurons, thereby confirming that pacemakers are synaptically coupled to motor networks in the spinal ventral horn. Notably, two classes of pacemakers could be distinguished in lamina I based on cell size and the pattern of their axonal projections. While small pacemaker neurons possessed ramified axons which contacted ipsilateral motor circuits, large pacemaker neurons had unbranched axons which crossed the midline and ascended rostrally in the contralateral white matter. Recordings from identified spino-parabrachial and spino-PAG neurons indicated the presence of pacemaker activity within neonatal lamina I projection neurons. Overall, these results show that lamina I pacemakers are positioned to regulate both the level of activity in developing motor circuits as well as the ascending flow of nociceptive information to the brain, thus highlighting a potential role for pacemaker activity in the maturation of pain and sensorimotor networks in the CNS. PMID:25380417

Formation of a solar Hα filament from orphan penumbrae

NASA Astrophysics Data System (ADS)

Buehler, D.; Lagg, A.; van Noort, M.; Solanki, S. K.

2016-05-01

Aims: The formation and evolution of an Hα filament in active region (AR) 10953 is described. Methods: Observations from the Solar Optical Telescope (SOT) aboard the Hinode satellite starting from UT 18:09 on 27th April 2007 until UT 06:08 on 1st May 2007 were analysed. 20 scans of the 6302 Å Fe I line pair recorded by SOT/SP were inverted using the spatially coupled version of the SPINOR code. The inversions were analysed together with co-spatial SOT/BFI G-band and Ca II H and SOT/NFI Hα observations. Results: Following the disappearance of an initial Hα filament aligned along the polarity inversion line (PIL) of the AR, a new Hα filament formed in its place some 20 h later, which remained stable for, at least, another 1.5 days. The creation of the new Hα filament was driven by the ascent of horizontal magnetic fields from the photosphere into the chromosphere at three separate locations along the PIL. The magnetic fields at two of these locations were situated directly underneath the initial Hα filament and formed orphan penumbrae already aligned along the Hα filament channel. The 700 G orphan penumbrae were stable and trapped in the photosphere until the disappearance of the overlying initial Hα filament, after which they started to ascend into the chromosphere at 10 ± 5 m/s. Each ascent was associated with a simultaneous magnetic flux reduction of up to 50% in the photosphere. The ascended orphan penumbrae formed dark seed structures in Hα in parallel with the PIL, which elongated and merged to form an Hα filament. The filament channel featured horizontal magnetic fields of on average 260 G at log (τ) = -2 suspended above the nearly field-free lower photosphere. The fields took on an overall inverse configuration at log (τ) = -2 suggesting a flux rope topology for the new Hα filament. The destruction of the initial Hα filament was likely caused by the flux emergence at the third location along the PIL. Conclusions: We present a new interpretation of the Hα filament formation in AR 10953 whereby the mainly horizontal fields of orphan penumbrae, aligned along the Hα filament channel, ascend into the chromosphere, forming seed fragments for a new, second Hα filament. The orphan penumbral fields ascend into the chromosphere ~9-24 h before the Hα filament is fully formed.

Aortic microcalcification is associated with elastin fragmentation in Marfan syndrome.

PubMed

Wanga, Shaynah; Hibender, Stijntje; Ridwan, Yanto; van Roomen, Cindy; Vos, Mariska; van der Made, Ingeborg; van Vliet, Nicole; Franken, Romy; van Riel, Luigi Amjg; Groenink, Maarten; Zwinderman, Aeilko H; Mulder, Barbara Jm; de Vries, Carlie Jm; Essers, Jeroen; de Waard, Vivian

2017-11-01

Marfan syndrome (MFS) is a connective tissue disorder in which aortic rupture is the major cause of death. MFS patients with an aortic diameter below the advised limit for prophylactic surgery (<5 cm) may unexpectedly experience an aortic dissection or rupture, despite yearly monitoring. Hence, there is a clear need for improved prognostic markers to predict such aortic events. We hypothesize that elastin fragments play a causal role in aortic calcification in MFS, and that microcalcification serves as a marker for aortic disease severity. To address this hypothesis, we analysed MFS patient and mouse aortas. MFS patient aortic tissue showed enhanced microcalcification in areas with extensive elastic lamina fragmentation in the media. A causal relationship between medial injury and microcalcification was revealed by studies in vascular smooth muscle cells (SMCs); elastin peptides were shown to increase the activity of the calcification marker alkaline phosphatase (ALP) and reduce the expression of the calcification inhibitor matrix GLA protein in human SMCs. In murine Fbn1 C1039G/+ MFS aortic SMCs, Alpl mRNA and activity were upregulated as compared with wild-type SMCs. The elastin peptide-induced ALP activity was prevented by incubation with lactose or a neuraminidase inhibitor, which inhibit the elastin receptor complex, and a mitogen-activated protein kinase kinase-1/2 inhibitor, indicating downstream involvement of extracellular signal-regulated kinase-1/2 (ERK1/2) phosphorylation. Histological analyses in MFS mice revealed macrocalcification in the aortic root, whereas the ascending aorta contained microcalcification, as identified with the near-infrared fluorescent bisphosphonate probe OsteoSense-800. Significantly, microcalcification correlated strongly with aortic diameter, distensibility, elastin breaks, and phosphorylated ERK1/2. In conclusion, microcalcification co-localizes with aortic elastin degradation in MFS aortas of humans and mice, where elastin-derived peptides induce a calcification process in SMCs via the elastin receptor complex and ERK1/2 activation. We propose microcalcification as a novel imaging marker to monitor local elastin degradation and thus predict aortic events in MFS patients. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Bilateral anomalous origins of the posterior meningeal artery from the ascending pharyngeal arteries.

PubMed

Hsu, C Y; Sheu, J J; Huang, K M; Li, Y W

2001-06-01

We present a rare case of angiographically confirmed dural arteriovenous fistula supplied mainly by the posterior meningeal artery with bilateral anomalous origins from the bilateral ascending pharyngeal arteries. The bilaterality of the origins of the posterior meningeal artery is important in the angiographic diagnosis and management of a dural vascular malformation in the posterior fossa or the posterior part of the falx cerebri.

Endovascular closure of ascending aortic pseudoaneurysm with a type II Amplatzer vascular plug.

PubMed

De Boo, Diederick W; Mott, Nigel; Kavnoudias, Helen; Walton, Antony; Lyon, Stuart M

2014-05-01

A 71-year-old man initially presented with an asymptomatic, incidentally detected ascending aortic pseudoaneurysm 25 years following aortic root repair with mechanical aortic valve replacement. This pseudoaneurysm was previously treated with coil embolization but due to coil impaction it reopened 8 years later. Endovascular closure of the pseudoaneurysm was achieved with the off-label use of a type II Amplatzer vascular plug.

Functional anatomy of the sleep-wakefulness cycle: wakefulness.

PubMed

Reinoso-Suárez, Fernando; de Andrés, Isabel; Garzón, Miguel

2011-01-01

Sleep is a necessary, diverse, periodic, and an active condition circadian and homeostatically regulated and precisely meshed with waking time into the sleep-wakefulness cycle (SWC). Photic retinal stimulation modulates the suprachiasmatic nucleus, which acts as the pacemaker for SWC rhythmicity. Both the light period and social cues adjust the internal clock, making the SWC a circadian, 24-h period in the adult human. Bioelectrical and behavioral parameters characterize the different phases of the SWC. For a long time, lesions and electrical stimulation of brain structures, as well as connection studies, were the main methods used to decipher the foundations of the functional anatomy of the SWC. That is why the first section of this review presents these early historical studies to then discuss the current state of our knowledge based on our understanding of the functional anatomy of the structures underlying the SWC. Supported by this description, we then present a detailed review and update of the structures involved in the phase of wakefulness (W), including their morphological, functional, and chemical characteristics, as well as their anatomical connections. The structures for W generation are known as the "ascending reticular activating system", and they keep and maintain the "thalamo-cerebral cortex unit" awake. This system originates from the neuronal groups located within the brainstem, hypothalamus, and basal forebrain, which use known neurotransmitters and whose neurons are more active during W than during the other SWC states. Thus, synergies among several of these neurotransmitters are necessary to generate the cortical and thalamic activation that is characteristic of the W state, with all the plastic qualities and nuances present in its different behavioral circumstances. Each one of the neurotransmitters exerts powerful influences on the information and cognitive processes as well as attentional, emotional, motivational, behavioral, and arousal states. The awake "thalamo-cerebral cortex unit" controls and adjusts the activation pattern through a top-down action on the subcortical cellular groups that are the origin of the "ascending reticular activating system".

Effective connectivity of ascending and descending frontal-thalamic pathways during sustained attention: Complex brain network interactions in adolescence

PubMed Central

Jagtap, Pranav; Diwadkar, Vaibhav A.

2016-01-01

Frontal-thalamic interactions are crucial for bottom-up gating and top-down control, yet have not been well studied from brain network perspectives. We applied network modeling of fMRI signals (Dynamic Causal Modeling; DCM) to investigate frontal-thalamic interactions during an attention task with parametrically varying levels of demand. fMRI was collected while subjects participated in a sustained continuous performance task with low and high attention demands. 162 competing model architectures were employed in DCM to evaluate hypotheses on bilateral frontal-thalamic connections and their modulation by attention demand, selected at a second level using Bayesian Model Selection. The model architecture evinced significant contextual modulation by attention of ascending (thalamus → dPFC) and descending (dPFC → thalamus) pathways. However, modulation of these pathways was asymmetric: While positive modulation of the ascending pathway was comparable across attention demand, modulation of the descending pathway was significantly greater when attention demands were increased. Increased modulation of the (dPFC → thalamus) pathway in response to increased attention demand constitutes novel evidence of attention-related gain in the connectivity of the descending attention pathway. By comparison demand-independent modulation of the ascending (thalamus → dPFC) pathway suggests unbiased thalamic inputs to the cortex in the context of the paradigm. PMID:27145923

Volcanic conduit failure as a trigger to magma fragmentation

NASA Astrophysics Data System (ADS)

Lavallée, Y.; Benson, P. M.; Heap, M. J.; Flaws, A.; Hess, K.-U.; Dingwell, D. B.

2012-01-01

In the assessment of volcanic risk, it is often assumed that magma ascending at a slow rate will erupt effusively, whereas magma ascending at fast rate will lead to an explosive eruption. Mechanistically viewed, this assessment is supported by the notion that the viscoelastic nature of magma (i.e., the ability of magma to relax at an applied strain rate), linked via the gradient of flow pressure (related to discharge rate), controls the eruption style. In such an analysis, the physical interactions between the magma and the conduit wall are commonly, to a first order, neglected. Yet, during ascent, magma must force its way through the volcanic edifice/structure, whose presence and form may greatly affect the stress field through which the magma is trying to ascend. Here, we demonstrate that fracturing of the conduit wall via flow pressure releases an elastic shock resulting in fracturing of the viscous magma itself. We find that magma fragmentation occurred at strain rates seven orders of magnitude slower than theoretically anticipated from the applied axial strain rate. Our conclusion, that the discharge rate cannot provide a reliable indication of ascending magma rheology without knowledge of conduit wall stability, has important ramifications for volcanic hazard assessment. New numerical simulations are now needed in order to integrate magma/conduit interaction into eruption models.

Helping early career research scientists ascend the professional ladder.

PubMed

King, Laina

2013-08-01

The Keystone Symposia Early Career Investigator Travel Award initiative is a unique successful research mentoring program tailored for 'end of the pipeline' life and biomedical scientists from academia and industry. Using targeted educational, mentoring, and networking activities, the program benefits early career scientists in solving a specific laboratory-based research question that is limiting their evolving research and could increase their ability to obtain new grants and improve their career progression. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Advance research on association between environmental compound and parkinson's disease].

PubMed

Li, X T; Cai, D F

2016-10-06

Parkinson's disease(PD)was the second most common neurodegenerative disorder after Alzheimer's disease. Incidence of PD was ascending year by year. The etiology of PD is poorly understood, involving aging, genetic and environmental factors. Recently, environmental compound had attracted more and more research interest. Studies and extrapolation from epidemiology, animal experiments and cell culture suggested that environmental compound had involved in the molecular mechanisms including mitochondrial dysfunction, oxidative stress, microglia activation, abnormal aggregation of α-synuclein and autophagy damage ,which seemed to increase PD risk.

Ultrasound Produces Extensive Brain Activation via a Cochlear Pathway.

PubMed

Guo, Hongsun; Hamilton, Mark; Offutt, Sarah J; Gloeckner, Cory D; Li, Tianqi; Kim, Yohan; Legon, Wynn; Alford, Jamu K; Lim, Hubert H

2018-06-06

Ultrasound (US) can noninvasively activate intact brain circuits, making it a promising neuromodulation technique. However, little is known about the underlying mechanism. Here, we apply transcranial US and perform brain mapping studies in guinea pigs using extracellular electrophysiology. We find that US elicits extensive activation across cortical and subcortical brain regions. However, transection of the auditory nerves or removal of cochlear fluids eliminates the US-induced activity, revealing an indirect auditory mechanism for US neural activation. Our findings indicate that US activates the ascending auditory system through a cochlear pathway, which can activate other non-auditory regions through cross-modal projections. This cochlear pathway mechanism challenges the idea that US can directly activate neurons in the intact brain, suggesting that future US stimulation studies will need to control for this effect to reach reliable conclusions. Copyright © 2018 Elsevier Inc. All rights reserved.

Research on active imaging information transmission technology of satellite borne quantum remote sensing

NASA Astrophysics Data System (ADS)

Bi, Siwen; Zhen, Ming; Yang, Song; Lin, Xuling; Wu, Zhiqiang

2017-08-01

According to the development and application needs of Remote Sensing Science and technology, Prof. Siwen Bi proposed quantum remote sensing. Firstly, the paper gives a brief introduction of the background of quantum remote sensing, the research status and related researches at home and abroad on the theory, information mechanism and imaging experiments of quantum remote sensing and the production of principle prototype.Then, the quantization of pure remote sensing radiation field, the state function and squeezing effect of quantum remote sensing radiation field are emphasized. It also describes the squeezing optical operator of quantum light field in active imaging information transmission experiment and imaging experiments, achieving 2-3 times higher resolution than that of coherent light detection imaging and completing the production of quantum remote sensing imaging prototype. The application of quantum remote sensing technology can significantly improve both the signal-to-noise ratio of information transmission imaging and the spatial resolution of quantum remote sensing .On the above basis, Prof.Bi proposed the technical solution of active imaging information transmission technology of satellite borne quantum remote sensing, launched researches on its system composition and operation principle and on quantum noiseless amplifying devices, providing solutions and technical basis for implementing active imaging information technology of satellite borne Quantum Remote Sensing.

Origins of serotonin innervation of forebrain structures

NASA Technical Reports Server (NTRS)

Kellar, K. J.; Brown, P. A.; Madrid, J.; Bernstein, M.; Vernikos-Danellis, J.; Mehler, W. R.

1977-01-01

The tryptophan hydroxylase activity and high-affinity uptake of (3H) serotonin ((3H)5-HT) were measured in five discrete brain regions of rats following lesions of the dorsal or median raphe nuclei. Dorsal raphe lesions reduced enzyme and uptake activity in the striatum only. Median raphe lesions reduced activities in the hippocampus, septal area, frontal cortex, and, to a lesser extent, in the hypothalamus. These data are consistent with the suggestion that the dorsal and median raphe nuclei are the origins of two separate ascending serotonergic systems - one innervating striatal structures and the other mesolimbic structures, predominantly. In addition, the data suggest that measurements of high-affinity uptake of (3H)5-HT may be a more reliable index of innervation than either 5-HT content or tryptophan hydroxylase activity.

Novel three-sinus enlargement technique for supravalvular aortic stenosis without aortic transection.

PubMed

Yokoyama, Shinya; Nagato, Hisao; Yoshida, Yuichi; Nagasaka, Shigeo; Kaneda, Kozo; Nishiwaki, Noboru

2016-01-16

Although repair of a supravalvular aortic stenosis (SVAS) can be performed with low mortality rates, surgery for the complex form of SVAS continues to be associated with a high incidence of residual stenosis. The patient was referred to our hospital at 1 month of age and was diagnosed with aortic valve stenosis (AS) by using echocardiography. Cardiac catheterization revealed moderate AS, and subsequent left ventriculography revealed discrete stenosis of the sino-tubular junction and a narrowed proximal ascending aorta. We performed a reconstructive operation for such heart defects involving novel three-sinus and ascending aorta enlargement without aortic root transection in a 6-month-old boy. Our novel three-sinus enlargement technique is suitable for treating each type of SVAS and is a useful method for a baby particularly less than 10 kg without disturbing the growth of the ascending aorta.

Phase transformations in an ascending adiabatic mixed-phase cloud volume

NASA Astrophysics Data System (ADS)

Pinsky, M.; Khain, A.; Korolev, A.

2015-04-01

Regimes of liquid-ice coexistence that may form in an adiabatic parcel ascending at constant velocity at freezing temperatures are investigated. Four zones with different microphysical structures succeeding one another along the vertical direction have been established. On the basis of a novel balance equation, analytical expressions are derived to determine the conditions specific for each of these zones. In particular, the necessary and sufficient conditions for formation of liquid water phase within an ascending parcel containing only ice particles are determined. The results are compared to findings reported in earlier studies. The role of the Wegener-Bergeron-Findeisen mechanism in the phase transformation is analyzed. The dependence of the phase relaxation time on height in the four zones is investigated on the basis of a novel analytical expression. The results obtained in the study can be instrumental for analysis and interpretation of observed mixed-phase clouds.

Control and Evaluation of a Powered Transfemoral Prosthesis for Stair Ascent.

PubMed

Ledoux, Elissa D; Goldfarb, Michael

2017-07-01

This paper assesses the metabolic effort exerted by three transfemoral amputees, when using a powered knee and ankle prosthesis for stair ascent, relative to ascending stairs with passive knee and ankle prostheses. The paper describes a controller that provides step-over stair ascent behavior reflective of healthy stair ascent biomechanics, and describes its implementation in a powered prosthesis prototype. Stair ascent experiments were performed with three unilateral transfemoral amputee subjects, comparing the oxygen consumption required to ascend stairs using the powered prosthesis (with a step-over gait), relative to using their daily-use energetically passive prostheses (with a step-to gait). Results indicate on average a 24% reduction in oxygen consumption and a 30% reduction in stair ascent timewhen using the powered prosthesis, relative to when using the passive prostheses. All subjects expressed a strong preference for ascending stairs using the powered prosthesis.

Evidence against bicarbonate reabsorption in the ascending limb, particularly as disclosed by free-water clearance studies.

PubMed Central

Seldin, D. W.; Rosin, J. M.; rector, F. C.

1975-01-01

Bicarbonate reabsorption in the thick ascending limb of Henle's loop was examined by studies of free-water clearance (CH2O) and free-water reabsorption (TcH2O). During maximal water diuresis in the dog, CH2O/GFR was taken as an indes of sodium reabsorption in, and urine flow (V/GFR) as an index of delivery of filtrate to, this scarbonate, infusion of a nonreabsorbable solute (hypotonic mannitol) and administration of an inhibitor of bicarbonate reabsorption (acetaent, but less than that achieved with hypotonic saline infusion. This suggests that sodium that sodium bicarbonate is not reabsorbed in the ascending limb. Rather, it is the sodium chloride, swept out of the proximal tubule by osmotic diuresis due to nonreabsorbed mannitol or sodium bicarbonate, that is reabsorbed in the ascending limb thereby increasing CH2O, whereas the nonreabsorption of mannitol and sodium bicarbonate results in a depressed CH20 per unit V when compared with hypotonic saline. V/GFR is not a satisfactory index of delivery to the ascending limb during osmotic diuresis, since it includes water obligated by nonreabsorbable solutes. When a better index of delivery, the sum of the clearances of chloride (CC1) and free-water (CH2O) is used, hypotonic bicarbonate infusion, hypotonic mannitol infusion and acetazolamide administration increase CH2O/GFR per unit delivery to the same extent as odes hypotonic saline infusion. Studies in dogs and rats on TcH2O also indicate that sodium bicarbonate is an impermeant solute in the ascending limb. Osmotic diuresis due to sodium bicarbonate diuresis, produced either by inhibition of sodium bicarbonate reabsorption (acetazolamide, L-lysine mono-hydrochloride) or infusion of sodium bicarbonate, or mannitol diuresis both produced marked chloruresis and increased TcH2O to the same extent as did hypertonic saline infusion. If chloride excretion was almost eliminated by hemodialysis against a chloride-free dialysate (dogs) or prolonged feeding of a salt-free diet (rats), TcH2O formation was unimpaired if hypertonic saline was infused but virtually obliterated during mannitol or sodium bicarbonate diuresis. Sodium reabsorption in the ascending limb, therefore, appears to be dependent upon chloride as the accompanying anion. At any given rate of bicarbonate excretion, more cloride is delivered out of the proximal tubule (as estimated from CC1 + CH2O) with hypotonic sodium bicarbonate infusion than with acetazolamide administration. This suggests that magnitude of the chlorutesis accompanying bicarbonate diuresis depends, not only on osmotic diuresis due to nonreabsorbed sodium bicarbonate, but also on the extent to which concomitant changes in effective extracellular volume influence overall sodium chloride reabsorption. PMID:1202762

Ascending aortic blood flow velocity is increased in children with primary snoring/mild sleep-disordered breathing and associated with an increase in CD8 +  T cells expressing TNFα and IFNγ.

PubMed

Kontos, Anna; Willoughby, Scott; van den Heuvel, Cameron; Kennedy, Declan; Martin, James; Hodge, Greg; Worthley, Matthew; Chin, Adelene Kaihui; Nelson, Adam; Teo, Karen; Baumert, Mathias; Pamula, Yvonne; Lushington, Kurt

2018-05-01

Sleep-disordered breathing (SDB) is associated with cardiovascular disease and systemic inflammation in adults but this remains to be explored in children, especially in children with the most common form of SDB, i.e. primary snoring/mild SDB. This pilot study investigated the relationship between the cardiovascular function and inflammation in children with mild SDB. Nineteen participants aged 5-14 years underwent overnight polysomnography, cardiac magnetic resonance imaging (aortic blood flow velocity and left and right ventricular systolic function) and assessment for inflammatory markers (intracellular cytokine analysis of T cells by flow cytometry). Parents also completed the Sleep Disturbances Scale for Children (SDSC). Children with mild SDB exhibited increased ascending aortic peak systolic velocity compared to controls (SDB 119.95 m/s vs. control 101.49 m/s, p < 0.05). No significant group differences were observed for left and right ventricular ejection fraction or mean aortic blood flow velocity from either the ascending aorta or pulmonary artery. Children with mild SDB had increased inflammatory markers as demonstrated by elevated T cell interferon gamma (IFNγ) (SDB 52 ± 4% vs. control 25 ± 3% positive cells, p < 0.005) and tumour necrosis factor alpha (TNFα) (SDB 39 ± 4% vs. control 20 ± 2% positive cells, p < 0.005) expression from CD8 + cells. A strong positive correlation was observed between ascending aorta peak blood flow velocity and both TNFα and IFNγ (TNFα, r = 0.54, p < 0.03; IFNγ, r = 0.63, p < 0.005, respectively). Polysomnography revealed that oxygen saturation (SaO 2 ) nadir was significantly lower in children with mild SDB compared to controls (SDB 92.3 ± 2.7% vs. control 94.4 ± 1.6%, p < 0.05). A lower SaO 2 nadir was associated with an increased ascending aorta peak systolic velocity (r = - 0.48, p < 0.05). As well, both a lower SaO 2 nadir and an increased ascending aorta peak systolic velocity were associated with higher SDSC Sleep-Disordered Breathing and Disorder of Initiating and Maintaining Sleep subscale scores but not the polysomnographic-derived Obstructive Apnea-Hypopnea Index. The finding of elevated ascending aortic peak systolic blood flow velocity and its association with increased inflammatory markers suggests that the profile of cardiovascular changes noted in adult SDB may also occur in children with mild SDB.

Function of a large biarticular hip and knee extensor during walking and running in guinea fowl (Numida meleagris).

PubMed

Carr, Jennifer A; Ellerby, David J; Marsh, Richard L

2011-10-15

Physiological and anatomical evidence suggests that in birds the iliotibialis lateralis pars postacetabularis (ILPO) is functionally important for running. Incorporating regional information, we estimated the mean sarcomere strain trajectory and electromyographic (EMG) amplitude of the ILPO during level and incline walking and running. Using these data and data in the literature of muscle energy use, we examined three hypotheses: (1) active lengthening will occur on the ascending limb of the length-tension curve to avoid potential damage caused by stretch on the descending limb; (2) the active strain cycle will shift to favor active shortening when the birds run uphill and shortening will occur on the plateau and shallow ascending limb of the length-tension curve; and (3) measures of EMG intensity will correlate with energy use when the mechanical function of the muscle is similar. Supporting the first hypothesis, we found that the mean sarcomere lengths at the end of active lengthening during level locomotion were smaller than the predicted length at the start of the plateau of the length-tension curve. Supporting the second hypothesis, the magnitude of active lengthening decreased with increasing slope, whereas active shortening increased. In evaluating the relationship between EMG amplitude and energy use (hypothesis 3), we found that although increases in EMG intensity with speed, slope and loading were positively correlated with muscle energy use, the quantitative relationships between these variables differed greatly under different conditions. The relative changes in EMG intensity and energy use by the muscle probably varied because of changes in the mechanical function of the muscle that altered the ratio of muscle energy use to active muscle volume. Considering the overall function of the cycle of active lengthening and shortening of the fascicles of the ILPO, we conclude that the function of active lengthening is unlikely to be energy conservation and may instead be related to promoting stability at the knee. The work required to lengthen the ILPO during stance is provided by co-contracting knee flexors. We suggest that this potentially energetically expensive co-contraction serves to stabilize the knee in early stance by increasing the mechanical impedance of the joint.

Cost-effective flow-through nanohole array-based biosensing platform for the label-free detection of uropathogenic E. coli in real time.

PubMed

Gomez-Cruz, Juan; Nair, Srijit; Manjarrez-Hernandez, Angel; Gavilanes-Parra, Sandra; Ascanio, Gabriel; Escobedo, Carlos

2018-05-30

Rapid, inexpensive and sensitive detection of uropathogenic Escherichia coli (UPEC), a common cause of ascending urinary tract infections (UTIs) including cystitis and pyelonephritis, is critical given the increasing number of cases and its recurrence worldwide. In this paper, we present a label-free nanoplasmonic sensing platform, built with off-the-shelf optical and electronic components, which can detect intact UPEC at concentrations lower than the physiological limit for UTI diagnosis, in real time. The sensing platform consists of a red LED light source, lens assembly, CMOS detector, Raspberry Pi interface in conjugation with a metallic flow-through nanohole array-based sensor. Detection is achieved exploiting nanoplasmonic phenomena from the nanohole arrays through surface plasmon resonance imaging (SPRi) technique. The platform has a bulk sensitivity of 212 pixel intensity unit (PIU)/refractive index unit (RIU), and a resolution in the order of 10 -6 RIU. We demonstrate capture and detection of UPEC with a detection limit of ~100 CFU/ml - a concentration well below the threshold limit for UTI diagnosis in clinical samples. We also demonstrate detection of UPEC in spiked human urine samples for two different concentrations of bacteria. This work is particularly relevant for point-of-care applications, especially for regions around the world where accessibility to medical facilities is heavily dependent upon economy, and availability. Copyright © 2018 Elsevier B.V. All rights reserved.

Ankle and Midfoot Power During Walking and Stair Ascent in Healthy Adults.

PubMed

DiLiberto, Frank E; Nawoczenski, Deborah A; Houck, Jeff

2018-02-27

Ankle power dominates forward propulsion of gait, but midfoot power generation is also important for successful push off. However, it is unclear if midfoot power generation increases or stays the same in response to propulsive activities that induce larger external loads and require greater ankle power. The purpose of this study was to examine ankle and midfoot power in healthy adults during progressively more demanding functional tasks. Multi-segment foot motion (tibia, calcaneus, forefoot) and ground reaction forces were recorded as participants (N=12) walked, ascended a standard step, and ascended a high step. Ankle and midfoot positive peak power and total power, and the proportion of midfoot to ankle total power were calculated. One-way repeated measures ANOVAs were conducted to evaluate differences across tasks. Main effects were found for ankle and midfoot peak and total powers (all p < .001), but not for the proportion of midfoot to ankle total power (p = .331). Ankle and midfoot power significantly increased across each task. Midfoot power increased in proportion to ankle power and in congruence to the external load of a task. Study findings may serve to inform multi-segment foot modeling applications and internal mechanistic theories of normal and pathological foot function.

Experimental Validation of Motor Primitive-Based Control for Leg Exoskeletons during Continuous Multi-Locomotion Tasks

PubMed Central

Ruiz Garate, Virginia; Parri, Andrea; Yan, Tingfang; Munih, Marko; Molino Lova, Raffaele; Vitiello, Nicola; Ronsse, Renaud

2017-01-01

An emerging approach to design locomotion assistive devices deals with reproducing desirable biological principles of human locomotion. In this paper, we present a bio-inspired controller for locomotion assistive devices based on the concept of motor primitives. The weighted combination of artificial primitives results in a set of virtual muscle stimulations. These stimulations then activate a virtual musculoskeletal model producing reference assistive torque profiles for different locomotion tasks (i.e., walking, ascending stairs, and descending stairs). The paper reports the validation of the controller through a set of experiments conducted with healthy participants. The proposed controller was tested for the first time with a unilateral leg exoskeleton assisting hip, knee, and ankle joints by delivering a fraction of the computed reference torques. Importantly, subjects performed a track involving ground-level walking, ascending stairs, and descending stairs and several transitions between these tasks. These experiments highlighted the capability of the controller to provide relevant assistive torques and to effectively handle transitions between the tasks. Subjects displayed a natural interaction with the device. Moreover, they significantly decreased the time needed to complete the track when the assistance was provided, as compared to wearing the device with no assistance. PMID:28367121

Shilajit: A panacea for high-altitude problems

PubMed Central

Meena, Harsahay; Pandey, H. K.; Arya, M. C.; Ahmed, Zakwan

2010-01-01

High altitude problems like hypoxia, acute mountain sickness, high altitude cerebral edema, pulmonary edema, insomnia, tiredness, lethargy, lack of appetite, body pain, dementia, and depression may occur when a person or a soldier residing in a lower altitude ascends to high-altitude areas. These problems arise due to low atmospheric pressure, severe cold, high intensity of solar radiation, high wind velocity, and very high fluctuation of day and night temperatures in these regions. These problems may escalate rapidly and may sometimes become life-threatening. Shilajit is a herbomineral drug which is pale-brown to blackish-brown, is composed of a gummy exudate that oozes from the rocks of the Himalayas in the summer months. It contains humus, organic plant materials, and fulvic acid as the main carrier molecules. It actively takes part in the transportation of nutrients into deep tissues and helps to overcome tiredness, lethargy, and chronic fatigue. Shilajit improves the ability to handle high altitudinal stresses and stimulates the immune system. Thus, Shilajit can be given as a supplement to people ascending to high-altitude areas so that it can act as a “health rejuvenator” and help to overcome high-altitude related problems. PMID:20532096

Shilajit: A panacea for high-altitude problems.

PubMed

Meena, Harsahay; Pandey, H K; Arya, M C; Ahmed, Zakwan

2010-01-01

High altitude problems like hypoxia, acute mountain sickness, high altitude cerebral edema, pulmonary edema, insomnia, tiredness, lethargy, lack of appetite, body pain, dementia, and depression may occur when a person or a soldier residing in a lower altitude ascends to high-altitude areas. These problems arise due to low atmospheric pressure, severe cold, high intensity of solar radiation, high wind velocity, and very high fluctuation of day and night temperatures in these regions. These problems may escalate rapidly and may sometimes become life-threatening. Shilajit is a herbomineral drug which is pale-brown to blackish-brown, is composed of a gummy exudate that oozes from the rocks of the Himalayas in the summer months. It contains humus, organic plant materials, and fulvic acid as the main carrier molecules. It actively takes part in the transportation of nutrients into deep tissues and helps to overcome tiredness, lethargy, and chronic fatigue. Shilajit improves the ability to handle high altitudinal stresses and stimulates the immune system. Thus, Shilajit can be given as a supplement to people ascending to high-altitude areas so that it can act as a "health rejuvenator" and help to overcome high-altitude related problems.

Brazil's remote sensing activities in the Eighties

NASA Technical Reports Server (NTRS)

Raupp, M. A.; Pereiradacunha, R.; Novaes, R. A.

1985-01-01

Most of the remote sensing activities in Brazil have been conducted by the Institute for Space Research (INPE). This report describes briefly INPE's activities in remote sensing in the last years. INPE has been engaged in research (e.g., radiance studies), development (e.g., CCD-scanners, image processing devices) and applications (e.g., crop survey, land use, mineral resources, etc.) of remote sensing. INPE is also responsible for the operation (data reception and processing) of the LANDSATs and meteorological satellites. Data acquisition activities include the development of CCD-Camera to be deployed on board the space shuttle and the construction of a remote sensing satellite.

Ascending aortic elongation and the risk of dissection.

PubMed

Krüger, Tobias; Forkavets, Oksana; Veseli, Kujtim; Lausberg, Henning; Vöhringer, Luise; Schneider, Wilke; Bamberg, Fabian; Schlensak, Christian

2016-08-01

Unlike aneurysm formation, the role of ascending aortic elongation in the pathogenesis of Type A aortic dissection (TAD) is largely unclear. We investigated the morphology of healthy, dissected and predissection aortas with a focus on ascending aortic length. We retrospectively compared clinical and computer tomography angiography (CTA) data from TAD patients (n = 130), patients who developed a TAD in the further clinical course (preTAD, n = 16) and healthy control patients who received a CTA for non-aortic emergencies (n = 165). The length of the ascending aorta was defined as the distance between the sinotubular junction (STJ) and the brachiocephalic trunk (BCT) at the central line, the outer and inner curvature as well as the direct distance in the frontal and sagittal planes. Additionally, the aortic diameters were analysed. In the healthy controls, we found a positive correlation of age with the aortic diameter (r = 0.57) and aortic length (r = 0.42). The correlation of the respective parameters with the body size was negligible (r < 0.2). The median ascending aortic diameter at the height of the pulmonary artery in TAD (50 mm) was significantly (P < 0.001) larger compared with the respective diameter of the healthy aortas (34 mm). The diameter of the preTAD aortas (40 mm) was also significantly larger compared with the healthy controls. These proportions were similar in all the aortic diameters. The midline length of the healthy ascending aortas was 71 mm. In the preTAD and TAD aortas, the same values were 81 mm and 92 mm, respectively (both P < 0.001). We evaluated the linear distance between the STJ and the BCT in the frontal plane as an easy-to-measure parameter of aortic length. In the TAD aortas (108 mm) and preTAD aortas (97 mm), this distance was significantly longer compared with the healthy aortas (84 mm). Aortic diameter might not be an optimal parameter to predict dissection. Most aortas dissect at diameters below 55 mm. Both the TAD and preTAD aortas were elongated compared with the healthy controls. Thus, aortic elongation may play a role in the pathogenesis of and may be a risk factor for TAD. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Angiotensin II stimulates superoxide production by nitric oxide synthase in thick ascending limbs.

PubMed

Gonzalez-Vicente, Agustin; Saikumar, Jagannath H; Massey, Katherine J; Hong, Nancy J; Dominici, Fernando P; Carretero, Oscar A; Garvin, Jeffrey L

2016-02-01

Angiotensin II (Ang II) causes nitric oxide synthase (NOS) to become a source of superoxide (O2 (-)) via a protein kinase C (PKC)-dependent process in endothelial cells. Ang II stimulates both NO and O2 (-) production in thick ascending limbs. We hypothesized that Ang II causes O2 (-) production by NOS in thick ascending limbs via a PKC-dependent mechanism. NO production was measured in isolated rat thick ascending limbs using DAF-FM, whereas O2 (-) was measured in thick ascending limb suspensions using the lucigenin assay. Consistent stimulation of NO was observed with 1 nmol/L Ang II (P < 0.001; n = 9). This concentration of Ang II-stimulated O2 (-) production by 50% (1.77 ± 0.26 vs. 2.62 ± 0.36 relative lights units (RLU)/s/μg protein; P < 0.04; n = 5). In the presence of the NOS inhibitor L-NAME, Ang II-stimulated O2 (-) decreased from 2.02 ± 0.29 to 1.10 ± 0.11 RLU/s/μg protein (P < 0.01; n = 8). L-arginine alone did not change Ang II-stimulated O2 (-) (2.34 ± 0.22 vs. 2.29 ± 0.29 RLU/s/μg protein; n = 5). In the presence of Ang II plus the PKC α/β1 inhibitor Gö 6976, L-NAME had no effect on O2 (-) production (0.78 ± 0.23 vs. 0.62 ± 0.11 RLU/s/μg protein; n = 7). In the presence of Ang II plus apocynin, a NADPH oxidase inhibitor, L-NAME did not change O2 (-) (0.59 ± 0.04 vs. 0.61 ± ×0.08 RLU/s/μg protein; n = 5). We conclude that: (1) Ang II causes NOS to produce O2 (-) in thick ascending limbs via a PKC- and NADPH oxidase-dependent process; and (2) the effect of Ang II is not due to limited substrate. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Signature of a possible relationship between the maximum CME speed index and the critical frequencies of the F1 and F2 ionospheric layers: Data analysis for a mid-latitude ionospheric station during the solar cycles 23 and 24

NASA Astrophysics Data System (ADS)

Kilcik, Ali; Ozguc, Atila; Yiǧit, Erdal; Yurchyshyn, Vasyl; Donmez, Burcin

2018-06-01

We analyze temporal variations of two solar indices, the monthly mean Maximum CME Speed Index (MCMESI) and the International Sunspot Number (ISSN) as well as the monthly median ionospheric critical frequencies (foF1, and foF2) for the time period of 1996-2013, which covers the entire solar cycle 23 and the ascending branch of the cycle 24. We found that the maximum of foF1 and foF2 occurred respectively during the first and second maximum of the ISSN solar activity index in the solar cycle 23. We compared these data sets by using the cross-correlation and hysteresis analysis and found that both foF1 and foF2 show higher correlation with ISSN than the MCMESI during the investigated time period, but when significance levels are considered correlation coefficients between the same indices become comparable. Cross-correlation analysis showed that the agreement between these data sets (solar indices and ionospheric critical frequencies) is better pronounced during the ascending phases of solar cycles, while they display significant deviations during the descending phase. We conclude that there exists a signature of a possible relationship between MCMESI and foF1 and foF2, which means that MCMESI could be used as a possible indicator of solar and geomagnetic activity, even though other investigations are needed.

Diminutive Porcelain Ascending Aorta With Supravalvular Aortic Stenosis.

PubMed

Houmsse, Mustafa; McDavid, Asia; Kilic, Ahmet

2018-05-01

This report describes the case of a 49-year-old man with a medical history significant for congenital aortic stenosis. The patient presented with progressive shortness of breath and decreased stamina and was found to have a concentric, diminutive porcelain ascending aorta with diffuse supravalvular aortic stenosis. We describe treatment with an aortic root augmentation and Bentall procedure using hypothermic circulatory arrest. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Ascending Stairway Modeling: A First Step Toward Autonomous Multi-Floor Exploration

DTIC Science & Technology

2012-10-01

Many robotics platforms are capable of ascending stairways, but all existing approaches for autonomous stair climbing use stairway detection as a...the rich potential of an autonomous ground robot that can climb stairs while exploring a multi-floor building. Our proposed solution to this problem is...over several steps. However, many ground robots are not capable of traversing tight spiral stairs , and so we do not focus on these types. The stairway is

High precision triangular waveform generator

DOEpatents

Mueller, Theodore R.

1983-01-01

An ultra-linear ramp generator having separately programmable ascending and descending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

High-precision triangular-waveform generator

DOEpatents

Mueller, T.R.

1981-11-14

An ultra-linear ramp generator having separately programmable ascending and decending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

Ascending aortic aneurysm and diaphragmatic hernia in a case of Marfan syndrome.

PubMed

Kothari, Jignesh; Hinduja, Manish; Baria, Kinnaresh; Pandya, Himani

2017-06-01

Marfan syndrome commonly affects the skeletal, ocular, and cardiovascular systems. Involvement of the gastrointestinal system is known but uncommon. Intervention depends upon the system involved and the severity of symptoms. Special awareness is required for the diagnosis and management of gastrointestinal involvement in these patients. We report a rare case of simultaneous surgical repair of an ascending aortic aneurysm and a type IV hiatal hernia in a 35-year-old man with Marfan syndrome.

Repair of an aneurysm of the ascending aorta and arch in an infant with Loeys-Dietz syndrome.

PubMed

Jaiswal, Pratiksha; Shetty, Varun; Patel, Ebrahim; Shetty, Deviprasad

2018-05-01

Aortic aneurysms in childhood are rare disease entities and are usually seen in patients with genetic connective tissue disorders such as Marfans, Ehler-Danlos, and Loeys-Dietz syndrome (LDS). Patients affected with LDS present early in life and have a rapid disease progression. We report a case of repair of an ascending and aortic arch aneurysm in an infant with Loeys-Dietz syndrome. © 2018 Wiley Periodicals, Inc.

Astronaut Brian Duffy, mission commander for the STS-72 mission, prepares to ascend stairs to the

NASA Technical Reports Server (NTRS)

1996-01-01

STS-72 TRAINING VIEW --- Astronaut Brian Duffy, mission commander for the STS-72 mission, prepares to ascend stairs to the flight deck of the fixed base Shuttle Mission Simulator (SMS) at the Johnson Space Center (JSC). Duffy will be joined by four other NASA astronauts and an international mission specialist aboard the Space Shuttle Endeavour for a scheduled nine-day mission, now set for the winter of this year.

Modelling and numerical simulation of the in vivo mechanical response of the ascending aortic aneurysm in Marfan syndrome.

PubMed

García-Herrera, Claudio M; Celentano, Diego J; Herrera, Emilio A

2017-03-01

Marfan syndrome (MFS) is a genetic disorder that affects connective tissue, impairing cardiovascular structures and function, such as heart valves and aorta. Thus, patients with Marfan disease have a higher risk of developing circulatory problems associated with mitral and aortic valves prolapse, manifested as dilated aorta and aortic aneurysm. However, little is known about the biomechanical characteristics of these structures affected with MFS. This study presents the modelling and simulation of the mechanical response of human ascending aortic aneurysms in MFS under in vivo conditions with intraluminal pressures within normotensive and hypertensive ranges. We obtained ascending aortic segments from five adults with MFS subjected to a vascular prosthesis implantation replacing an aortic aneurysm. We characterised the arterial samples via ex vivo tensile test measurements that enable fitting the material parameters of a hyperelastic isotropic constitutive model. Then, these material parameters were used in a numerical simulation of an ascending aortic aneurysm subjected to in vivo normotensive and hypertensive conditions. In addition, we assessed different constraints related to the movement of the aortic root. Overall, our results provide not only a realistic description of the mechanical behaviour of the vessel, but also useful data about stress/stretch-based criteria to predict vascular rupture. This knowledge may be included in the clinical assessment to determine risk and indicate surgical intervention.

Cross-cultural adaptation and validation of the Arabic version of the knee outcome survey-activities for daily living scale.

PubMed

Bouzubar, Fawzi F; Aljadi, Sameera H; Alotaibi, Naser M; Irrgang, James J

2018-07-01

The purpose of this study is to cross-culturally adapt the Knee Outcome Survey-Activities of Daily Living Scale into Arabic and to assess its psychometric properties (internal consistency, reliability, validity, and responsiveness) in patients with knee disorders. The cross-cultural adaptation process for the Knee Outcome Survey-Activities of Daily Living Scale into Arabic was performed consistent with the published guidelines. The psychometric properties of this Arabic version were then evaluated. Participants completed this version three times: at baseline, 2-4 days later, and 4 weeks later. Correlations between the Arabic version of Knee Outcome Survey-Activities of Daily Living Scale and the Arabic version of the Short Form-36 Health Survey, Get Up and Go, and Ascending/Descending stairs tests were evaluated. Linguistic and cultural issues were addressed. The Arabic version of the Knee Outcome Survey-Activities of Daily Living Scale demonstrated excellent internal consistency (Cronbach's alpha = 0.97) and excellent test-retest reliability (intraclass correlation coefficient = 0.97). Construct validity of the Arabic version of the Knee Outcome Survey-Activities of Daily Living Scale with the Arabic version of Short Form-36 Health Survey subscales ranged from r = 0.28 to 0.53, p < 0.001. Criterion validity with the Get Up and Go and Ascending/Descending stairs tests ranged from r = -0.47 to -0.60, p < 0.01. This Arabic version was able to detect changes 4 weeks later (effect size = 1.12 and minimum clinically important difference = 14 points). The Arabic version of the Knee Outcome Survey-Activities of Daily Living Scale is a reliable, valid and responsive measure for assessing knee-related symptoms and functional limitations Implications for rehabilitation The Knee Outcome Survey-Activities of Daily Living Scale-Arabic is a reliable, valid and responsive measure for assessing knee-related functional limitations. This Arabic version can be used in clinical practice and for research purposes to assess symptoms and functional limitations in Arabic-speaking patients with knee disorders. This scale is responsive to track therapeutic outcome of Arabic-speaking patients with knee disorders.

Supramammillary serotonin reduction alters place learning and concomitant hippocampal, septal, and supramammillar theta activity in a Morris water maze

PubMed Central

Hernández-Pérez, J. Jesús; Gutiérrez-Guzmán, Blanca E.; López-Vázquez, Miguel Á.; Olvera-Cortés, María E.

2015-01-01

Hippocampal theta activity is related to spatial information processing, and high-frequency theta activity, in particular, has been linked to efficient spatial memory performance. Theta activity is regulated by the synchronizing ascending system (SAS), which includes mesencephalic and diencephalic relays. The supramamillary nucleus (SUMn) is located between the reticularis pontis oralis and the medial septum (MS), in close relation with the posterior hypothalamic nucleus (PHn), all of which are part of this ascending system. It has been proposed that the SUMn plays a role in the modulation of hippocampal theta-frequency; this could occur through direct connections between the SUMn and the hippocampus or through the influence of the SUMn on the MS. Serotonergic raphe neurons prominently innervate the hippocampus and several components of the SAS, including the SUMn. Serotonin desynchronizes hippocampal theta activity, and it has been proposed that serotonin may regulate learning through the modulation of hippocampal synchrony. In agreement with this hypothesis, serotonin depletion in the SUMn/PHn results in deficient spatial learning and alterations in CA1 theta activity-related learning in a Morris water maze. Because it has been reported that SUMn inactivation with lidocaine impairs the consolidation of reference memory, we asked whether changes in hippocampal theta activity related to learning would occur through serotonin depletion in the SUMn, together with deficiencies in memory. We infused 5,7-DHT bilaterally into the SUMn in rats and evaluated place learning in the standard Morris water maze task. Hippocampal (CA1 and dentate gyrus), septal and SUMn EEG were recorded during training of the test. The EEG power in each region and the coherence between the different regions were evaluated. Serotonin depletion in the SUMn induced deficient spatial learning and altered the expression of hippocampal high-frequency theta activity. These results provide evidence in support of a role for serotonin as a modulator of hippocampal learning, acting through changes in the synchronicity evoked in several relays of the SAS. PMID:26578960

76 FR 65529 - Agency Information Collection Activities: Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-21

... National Land Remote Sensing Education, Outreach and Research Activity (NLRSEORA). As required by the... Drive MS 517, Reston, VA, 20192 (mail) . SUPPLEMENTARY INFORMATION: Title: National Land Remote Sensing... Remote Sensing Program, therefore it is more appropriate to refer to this effort as an activity rather...

Active/Passive Remote Sensing of the Ocean Surface at Microwave Frequencies

DTIC Science & Technology

1999-09-30

This report summarizes research activities and results obtained under grant N000l4-99-1-0627 "Active/Passive Remote Sensing of the Ocean Surface at...Measurements were completed during April 1999 by the Microwave Remote Sensing Laboratory at the University of Massachusetts.

Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae.

PubMed

Defoirdt, Tom; Sorgeloos, Patrick

2012-12-01

Quorum sensing, bacterial cell-to-cell communication, has been linked to the virulence of pathogenic bacteria. Indeed, in vitro experiments have shown that many bacterial pathogens regulate the expression of virulence genes by this cell-to-cell communication process. Moreover, signal molecules have been detected in samples retrieved from infected hosts and quorum sensing disruption has been reported to result in reduced virulence in different host-pathogen systems. However, data on in vivo quorum sensing activity of pathogens during infection of a host are currently lacking. We previously reported that quorum sensing regulates the virulence of Vibrio harveyi in a standardised model system with gnotobiotic brine shrimp (Artemia franciscana) larvae. Here, we monitored quorum sensing activity in Vibrio harveyi during infection of the shrimp, using bioluminescence as a read-out. We found that wild-type Vibrio harveyi shows a strong increase in quorum sensing activity early during infection. In this respect, the bacteria behave remarkably similar in different larvae, despite the fact that only half of them survive the infection. Interestingly, when expressed per bacterial cell, Vibrio harveyi showed around 200-fold higher maximal quorum sensing-regulated bioluminescence when associated with larvae than in the culture water. Finally, the in vivo quorum sensing activity of mutants defective in the production of one of the three signal molecules is consistent with their virulence, with no detectable in vivo quorum sensing activity in AI-2- and CAI-1-deficient mutants. These results indicate that AI-2 and CAI-1 are the dominant signals during infection of brine shrimp.

Monitoring of Vibrio harveyi quorum sensing activity in real time during infection of brine shrimp larvae

PubMed Central

Defoirdt, Tom; Sorgeloos, Patrick

2012-01-01

Quorum sensing, bacterial cell-to-cell communication, has been linked to the virulence of pathogenic bacteria. Indeed, in vitro experiments have shown that many bacterial pathogens regulate the expression of virulence genes by this cell-to-cell communication process. Moreover, signal molecules have been detected in samples retrieved from infected hosts and quorum sensing disruption has been reported to result in reduced virulence in different host–pathogen systems. However, data on in vivo quorum sensing activity of pathogens during infection of a host are currently lacking. We previously reported that quorum sensing regulates the virulence of Vibrio harveyi in a standardised model system with gnotobiotic brine shrimp (Artemia franciscana) larvae. Here, we monitored quorum sensing activity in Vibrio harveyi during infection of the shrimp, using bioluminescence as a read-out. We found that wild-type Vibrio harveyi shows a strong increase in quorum sensing activity early during infection. In this respect, the bacteria behave remarkably similar in different larvae, despite the fact that only half of them survive the infection. Interestingly, when expressed per bacterial cell, Vibrio harveyi showed around 200-fold higher maximal quorum sensing-regulated bioluminescence when associated with larvae than in the culture water. Finally, the in vivo quorum sensing activity of mutants defective in the production of one of the three signal molecules is consistent with their virulence, with no detectable in vivo quorum sensing activity in AI-2- and CAI-1-deficient mutants. These results indicate that AI-2 and CAI-1 are the dominant signals during infection of brine shrimp. PMID:22673627

High-resolution DEM generation from multiple remote sensing data sources for improved volcanic hazard assessment - a case study from Nevado del Ruiz, Colombia

NASA Astrophysics Data System (ADS)

Deng, Fanghui; Dixon, Timothy H.; Rodgers, Mel; Charbonnier, Sylvain J.; Gallant, Elisabeth A.; Voss, Nicholas; Xie, Surui; Malservisi, Rocco; Ordoñez, Milton; López, Cristian M.

2017-04-01

Eruptions of active volcanoes in the presence of snow and ice can cause dangerous floods, avalanches and lahars, threatening millions of people living close to such volcanoes. Colombia's deadliest volcanic hazard in recorded history was caused by Nevado del Ruiz Volcano. On November 13, 1985, a relatively small eruption triggered enormous lahars, killing over 23,000 people in the city of Armero and 2,000 people in the town of Chinchina. Meltwater from a glacier capping the summit of the volcano was the main contributor to the lahars. From 2010 to present, increased seismicity, surface deformation, ash plumes and gas emissions have been observed at Nevado del Ruiz. The DEM is a key parameter for accurate prediction of the pathways of lava flows, pyroclastic flows, and lahars. While satellite coverage has greatly improved the quality of DEMs around the world, volcanoes remain a challenging target because of extremely rugged terrain with steep slopes and deeply cut valleys. In this study, three types of remote sensing data sources with different spatial scales (satellite radar interferometry, terrestrial radar interferometry (TRI), and structure from motion (SfM)) were combined to generate a high resolution DEM (10 m) of Nevado del Ruiz. 1) Synthetic aperture radar (SAR) images acquired by TSX/TDX satellites were applied to generate DEM covering most of the study area. To reduce the effect of geometric distortion inherited from SAR images, TSX/TDX DEMs from ascending and descending orbits were merged to generate a 10×10 m DEM. 2) TRI is a technique that uses a scanning radar to measure the amplitude and phase of a backscattered microwave signal. It provides a more flexible and reliable way to generate DEMs in steep-slope terrain compared with TSX/TDX satellites. The TRI was mounted at four different locations to image the upper slopes of the volcano. A DEM with 5×5 m resolution was generated by TRI. 3) SfM provides an alternative for shadow zones in both TSX/TDX and TRI images. It is a low-cost and effective method to generate high-quality DEMs in relatively small spatial scales. More than 2000 photos were combined to create a DEM of the deep valley in the shadow zones. DEMs from the above three remote sensing data sources were merged into a final DEM with 10×10 m resolution. The effect of this improved DEM on hazard assessment can be evaluated using numerical flow models.

Characterizing seasonal and diel vertical movement and habitat use of lake whitefish (Coregonus clupeaformis) in Clear Lake, Maine

USGS Publications Warehouse

Zydlewski, Joseph D.; Gorsky, Dimitry; Balsey, David

2016-01-01

Seasonal and daily vertical activity of lake whitefish Coregonus clupeaformis was studied in Clear Lake, Maine (253 ha), using acoustic telemetry from November 2004 to June 2009. Twenty adult lake whitefish were tagged with acoustic tags that had either a depth sensor or both depth and temperature sensors to assess vertical habitat use at a seasonal and daily resolution. Vertical habitat selection varied seasonally and was strongly influenced by temperature. Between December and April, when the lake was covered with ice, surface temperature was below 2°C and tagged individuals occupied deep areas of the lake (∼15 m). After ice-out, fish ascended into shallow waters (∼5 m), responding to increased water temperature and possibly to greater foraging opportunity. When surface water temperatures exceeded 20°C, fish descended below the developing thermocline (∼9 m), where they remained until surface temperatures fell below 20°C; fish then ascended into shallower depths, presumably for feeding and spawning. Through the winter, fish remained in thermal habitats that were warmer than the surface temperatures; in the summer, they selected depths with thermal habitats below 15°C. Though the amplitude varied greatly across seasons, lake whitefish displayed a strong diurnal pattern of activity as measured by vertical velocities. Fish were twofold more active during spring, summer, and fall than during winter. Lake whitefish exhibited diel vertical migrations, rising in the water column during nighttime and occupying deeper waters during the day. This pattern was more pronounced in the spring and fall and far less prominent during winter and summer. The strong linkage between temperature and habitat use may limit the current range of lake whitefish and may be directly impacted by climatic change.

Adjusting the light in the limit conditions of consciousness by the means of ascending reticular activating system (ARAS) and of subordinated systems

PubMed Central

Aliu, Octavian Florin

2014-01-01

Background: In our activity in the Ambulance Service of Bucharest Municipality during March 2002 – March 2003 we studied a casuistry of patients who had fallen in a coma of varying degrees. To aid better understanding of coma, the concept of “pre-coma stage” or “diencephalic 0 stage” was introduced. This concept complements the Arseni classification already used in medical practice, because some doctors alternatively use the term of “inaugural coma” for the same condition that we call diencephalic “0 stage”. In the median hypothalamus and on the retino-hypothalamic path (SCN - AN) optical waves are transmitted, probably in the near infrared spectral range (800–1000 nm) in what we term the ascending reticular activating system (ARAS). These waves would constitute a means of transmitting information via the ARAS about the infradian biorhythm of coordination (frequencies below 1 cycle/28 hours), essential for the modulation and pre-processing of the consciousness and wakefulness, a fact which has already been demonstrated in animals. Methods: The current work is based on observations made on a group of 51 patients with the precoma and coma conditions, and on a thorough study of the specialized (especially Romanian) literature. Also, we used validated scientific proof of torture in conditions of lack of light. Results: We found a perfect interpenetration between the ARAS and the following two complementary subsystems: 1. The hypothalamic suprachiasmatic nucleus, that has the role of coordinating the periodicity of some biological functions depending on the circadian rhythm; and 2. The main photoperiodic organ, the pineal gland (epiphysis), which together with the ARAS has a role in the photoperiodicity modulation of some biological functions during the state of vigilance. PMID:25071308

Acute Noxious Stimulation Modifies Morphine Effect in Serotonergic but not Dopaminergic Midbrain Areas

PubMed Central

Bajic, Dusica; Commons, Kathryn G.

2010-01-01

It is poorly understood if and how pain may modify the effect of opioids on neural systems that contribute to reward and addictive behavior. We hypothesized that the activation of ascending dopaminergic and serotonergic nuclei by morphine is modified by the presence of noxious stimulation. Immunohistochemical double-labeling technique with Fos was used to examine if an intraplantar formalin injection, an acute noxious input, changed the effect of morphine on dopaminergic neurons of the ventral tegmental area (VTA), and serotonergic neurons of the dorsal raphe nucleus (DR). Four groups of rats were analyzed: (1) CONTROL injected with normal saline subcutaneously, (2) rats treated with FORMALIN into the hind paw 30 minutes after normal saline injection, (3) rats injected with MORPHINE sulfate subcutaneously, and (4) rats treated with formalin into the hind paw 30 minutes after morphine injection (MORPHINE/FORMALIN). Following morphine injection, there was an increase in the number of dopaminergic neurons in the VTA with Fos immunolabeling. However, noxious stimulation did not detectably change morphine's effect on Fos expression in VTA dopamine neurons. In contrast, the number of serotonergic neurons containing Fos was increased in the morphine/formalin group compared to all other groups and this effect was topographically selective for the dorsal area of the DR at mid rostro-caudal levels. Therefore, morphine's activation of the VTA, which is associated with motivated behavior and reward seeking, appears similar in the context of pain. However, activation of the ascending serotonin system, which influences mood and has the capacity to modify reward pathways, appears different. In addition, these findings reveal interactions between nociceptive signaling and opioids that contrasts with the notion that opioids simply block access of nociceptive signaling to supraspinal structures. PMID:20026253

Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

NASA Technical Reports Server (NTRS)

Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

2014-01-01

NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

Effects of Simvastatin Beyond Dyslipidemia: Exploring Its Antinociceptive Action in an Animal Model of Complex Regional Pain Syndrome-Type I

PubMed Central

Vieira, Graziela; Cavalli, Juliana; Gonçalves, Elaine C. D.; Gonçalves, Tainara R.; Laurindo, Larissa R.; Cola, Maíra; Dutra, Rafael C.

2017-01-01

Simvastatin is a lipid-lowering agent that blocks the production of cholesterol through inhibition of 3-hydroxy-methyl-glutaryl coenzyme A (HMG-CoA) reductase. In addition, recent evidence has suggested its anti-inflammatory and antinociceptive actions during inflammatory and pain disorders. Herein, we investigated the effects of simvastatin in an animal model of complex regional pain syndrome-type I, and its underlying mechanisms. Chronic post-ischemia pain (CPIP) was induced by ischemia and reperfusion (IR) injury of the left hind paw. Our findings showed that simvastatin inhibited mechanical hyperalgesia induced by CPIP model in single and repeated treatment schedules, respectively; however simvastatin did not alter inflammatory signs during CPIP model. The mechanisms underlying those actions are related to modulation of transient receptor potential (TRP) channels, especially TRMP8. Moreover, simvastatin oral treatment was able to reduce the nociception induced by acidified saline [an acid-sensing ion channels (ASICs) activator] and bradykinin (BK) stimulus, but not by TRPA1, TRPV1 or prostaglandin-E2 (PGE2). Relevantly, the antinociceptive effects of simvastatin did not seem to be associated with modulation of the descending pain circuits, especially noradrenergic, serotoninergic and dopaminergic systems. These results indicate that simvastatin consistently inhibits mechanical hyperalgesia during neuropathic and inflammatory disorders, possibly by modulating the ascending pain signaling (TRPM8/ASIC/BK pathways expressed in the primary sensory neuron). Thus, simvastatin open-up new standpoint in the development of innovative analgesic drugs for treatment of persistent pain, including CRPS-I. PMID:28928655

Intrapericardial denervation: Responses to water immersion in rhesus monkeys

NASA Technical Reports Server (NTRS)

McKeever, Kenneth H.; Keil, Lanny C.; Sandler, Harold

1995-01-01

Eleven anesthetized rhesus monkeys were used to study cardiovascular, renal, and endocrine alterations associated with 120 min of head-out water immersion. Five animals underwent complete intrapericardial denervation using the Randall technique, while the remaining six monkeys served as intact controls. Each animal was chronically instrumented with an electromagnetic flow probe on the ascending aorta, a strain gauge pressure transducer implanted in the apex of the left ventricle (LV), and electrocardiogram leads anchored to the chest wall and LV. During immersion, LV end-diastolic pressure, urine flow, glomerular filtration rate, sodium excretion, and circulating atrial natriuretic peptide (ANP) each increased (P less than 0.05) for intact and denervated monkeys. There were no alterations in free water clearance in either group during immersion, yet fractional excretion of free water increased (P less than 0.05) in the intact monkeys. Plasma renin activity (PRA) decreased (P less than 0.05) during immersion in intact monkeys but not the denervated animals. Plasma vasopressin (PVP) concentration decreased (P less than 0.05) during the first 30 min of immersion in both groups but was not distinguishable from control by 60 min of immersion in denervated monkeys. These data demonstrate that complete cardiac denervation does not block the rise in plasma ANP or prevent the natriuresis associated with head-out water immersion. The suppression of PVP during the first minutes of immersion after complete cardiac denervation suggests that extracardiac sensing mechanisms associated with the induced fluid shifts may be responsible for the findings. water immersion; natriuresis; vasopressin; eardiae denervation; monkey

Improved characterization of slow-moving landslides by means of adaptive NL-InSAR filtering

NASA Astrophysics Data System (ADS)

Albiol, David; Iglesias, Rubén.; Sánchez, Francisco; Duro, Javier

2014-10-01

Advanced remote sensing techniques based on space-borne Synthetic Aperture Radar (SAR) have been developed during the last decade showing their applicability for the monitoring of surface displacements in landslide areas. This paper presents an advanced Persistent Scatterer Interferometry (PSI) processing based on the Stable Point Network (SPN) technique, developed by the company Altamira-Information, for the monitoring of an active slowmoving landslide in the mountainous environment of El Portalet, Central Spanish Pyrenees. For this purpose, two TerraSAR-X data sets acquired in ascending mode corresponding to the period from April to November 2011, and from August to November 2013, respectively, are employed. The objective of this work is twofold. On the one hand, the benefits of employing Nonlocal Interferomtric SAR (NL-InSAR) adaptive filtering techniques over vegetated scenarios to maximize the chances of detecting natural distributed scatterers, such as bare or rocky areas, and deterministic point-like scatterers, such as man-made structures or poles, is put forward. In this context, the final PSI displacement maps retrieved with the proposed filtering technique are compared in terms of pixels' density and quality with classical PSI, showing a significant improvement. On the other hand, since SAR systems are only sensitive to detect displacements in the line-of-sight (LOS) direction, the importance of projecting the PSI displacement results retrieved along the steepest gradient of the terrain slope is discussed. The improvements presented in this paper are particularly interesting in these type of applications since they clearly allow to better determine the extension and dynamics of complex landslide phenomena.

Synthetic Aperture Radar Interferometry Analysis of Ground Deformation within the Coso Geothermal Site, California

NASA Astrophysics Data System (ADS)

Brawner, Erik

Earth's surface movement may cause as a potential hazard to infrastructure and people. Associated earthquake hazards pose a potential side effect of geothermal activity. Modern remote sensing techniques known as Interferometric Synthetic Aperture Radar (InSAR) can measure surface change with a high degree of precision to mm scale movements. Previous work has identified a deformation anomaly within the Coso Geothermal site in eastern California. Surface changes have not been analyzed since the 1990s, allowing a decade of geothermal production impact to occur since previously assessed. In this study, InSAR data was acquired and analyzed between the years 2005 and 2010. Acquired by the ENVISAT satellite from both ascending and descending modes. This provides an independent dataset from previous work. Incorporating data generated from a new sensor covering a more modern temporal study period. Analysis of this time period revealed a subsidence anomaly in correlation with the extents of the geothermal production area under current operation. Maximum subsidence rates in the region reached approximately 3.8 cm/yr. A similar rate assessed from previous work throughout the 1990s. The correlation of subsidence patterns suggests a linear source of deformation from measurements spanning multiple decades. Regions of subsidence branch out from the main anomaly to the North-Northeast and to the South where additional significant peaks of subsidence occurring. The extents of the deformation anomaly directly correlate with the dispersal of geothermal production well site locations. Depressurization within the geothermal system provides a leading cause to surface subsidence from excessive extraction of hydrothermal fluids. As a result of minimal reinjection of production fluids.

Characteristics of aortic valve dysfunction and ascending aorta dimensions according to bicuspid aortic valve morphology.

PubMed

Shin, Hong Ju; Shin, Je Kyoun; Chee, Hyun Kun; Kim, Jun Suk; Ko, Sung Min

2015-07-01

To characterize aortic valve dysfunction and ascending aorta dimensions according to bicuspid aortic valve (BAV) morphology using computed tomography (CT) and surgical findings. We retrospectively enrolled 209 patients with BAVs who underwent transthoracic echocardiography (TTE) and CT. BAVs were classified as anterior-posterior (BAV-AP) or lateral (BAV-LA) orientation of the cusps and divided according to the presence (raphe+) or absence (raphe-) of a raphe. Ascending aortic dimensions were measured by CT at four levels. BAV-AP was present in 129 patients (61.7%) and raphe+ in 120 (57.4%). Sixty-nine patients (33.0%) had aortic regurgitation (AR), 70 (33.5%) had aortic stenosis (AS), and 58 (27.8%) had combined AS and AR. AR was more common in patients with BAV-AP and raphe+; AS was more common with BAV-LA and raphe-.Annulus/body surface area and tubular portion/body surface area diameters in patients with BAV-AP (17.1 ± 2.3 mm/m(2) and 24.2 ± 5.3 mm/m(2), respectively) and raphe+ (17.3 ± 2.2 mm/m(2) and 24.2 ± 5.5 mm/m(2), respectively) were significantly different from those with BAV-LA (15.8 ± 1.9 mm/m(2) and 26.4 ± 5.5 mm/m(2), respectively) and raphe- (15.7 ± 1.9 mm/m(2) and 26.2 ± 5.4 mm/m(2), respectively). The morphological characteristics of BAV might be associated with the type of valvular dysfunction, and degree and location of an ascending aorta dilatation. • The BAV-AP type had more frequent aortic regurgitation, raphe, and a larger aortic annulus. • BAV without raphe had more frequent aortic stenosis and mid-ascending aorta dilatation. • CT allows assessment of the morphological characteristics of BAV and associated aortopathy.

The value of transthoracic echocardiography in the diagnosis of anomalous origin of the right pulmonary artery from the ascending aorta: A single center experience from China.

PubMed

Wang, Jing; Song, Yue; Cheng, Tsung O; Xie, Mingxing; Wang, Xinfang; Yuan, Li; Yang, Yali; Wang, Lei

2015-04-01

Anomalous origin of pulmonary artery (AOPA) from the ascending aorta is a rare but serious congenital cardiac malformation, which frequently involves the right pulmonary artery (RPA). We retrospectively analyzed the echocardiographic characteristics of 9 cases with anomalous origin of the right pulmonary artery from the ascending aorta (AORPA) studied from 2007 to 2014 in our institution. The results were compared with the findings at surgery. The corrective surgery was performed in all 9 cases with AORPA. The diagnosis by transthoracic echocardiography (TTE) of 8 cases with AORPA was confirmed at surgery. The coincidence rate for TTE and surgical findings was 88.9%. One case was misdiagnosed as anomalous origin of the left pulmonary artery from the ascending aorta. The anomalous RPA in all cases had a proximal origin from the posterior or lateral part of the ascending aorta in our series. The mean distance from the aortic valve to the site of origin of pulmonary artery was 16.1 ± 6.6 mm (range: 7.0 mm-24.0 mm). The mean diameter of the anomalous pulmonary artery was 9.6 ± 4.5 mm (range: 4.5 mm-17.0 mm). In 4 of 9 (44.5%) cases there were associated aortopulmonary septal defect, intact ventricular septum, patent ductus arteriosus and interruption of aortic arch (Type A), also known as the Berry's syndrome. Other associated cardiovascular abnormalities included patent ductus arteriosus, ventricular septal defect and atrial septal defect. Severe pulmonary arterial hypertension was noted in all cases. TTE plays an important role in the non-invasive and accurate diagnosis of AORPA. TTE can clearly display its site of origin and course, as well as other associated malformations and hemodynamic changes. TTE also plays an important role in the preoperative diagnosis of AORPA. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Increased plasma asymmetric dimethylarginine level is associated with ascending aorta dilatation: a case-control study.

PubMed

Satılmışoğlu, Muhammet Hulusi; Örnek Diker, Vesile; Taşbulak, Ömer; Diker, Mustafa; Birand, Ali; Kaya, Mehmet; İyigün, Taner; Eksik, Abdurrahman

2017-01-01

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase. We aimed to determine plasma ADMA levels in patients with ascending aorta dilatation in comparison to those without aorta dilatation, and to evaluate the diagnostic, predictive, and prognostic value of serum ADMA level for aorta dilatation. This was a cross-sectional case-control study. A total of 104 consecutive patients (female/male, 35/69; mean age, 62.75 ± 13.11 years) diagnosed with ascending aorta dilatation (≥ 4.5 cm) on echocardiography (case group), and 52 age-and gender-matched patients (female/male, 17/35; mean age, 63.44 ± 7.56 years) with normal aorta dimensions (≤ 3.8 cm) (control group) were included. Routine biochemical and haematological analysis in addition to measurement of serum ADMA level were performed. The mean diameter of ascending aorta measured on echocardiography was 4.95 ± 0.57 cm and 3.34 ± 0.36 cm in patients with aorta dilatation and those without aorta dilatation, respectively (p < 0.001). Serum ADMA level was significantly higher in patients with aorta dilatation than in the control group (1.70 ± 1.12 μmol/L vs. 0.79 ± 0.76 μmol/L, respectively, p < 0.001). There was significant positive correlation between ADMA level and aortic diameter in Spearman correlation analysis (r = 0.317, p < 0.001). In linear regression analysis, ADMA was found to be a significant independent predictor of aorta diameter (Beta = 0.26, p < 0.001). Receiver-operator characteristic curve analysis also revealed that serum ADMA cut-off level over 0.29 μmol/L predicts aorta dilatation (≥ 4.5 cm) with 94% sensitivity and 92% specificity and with high ac-curacy (area under curve: 0.786; 95% confidence interval: 0.709-0.863, p < 0.001). Serum ADMA level is diagnostic for ascending aorta dilatation with high sensitivity and specificity, and should be considered for use in clinical diagnosis of aorta dilatation.

Trans-apical aortic valve implantation in patients with severe calcification of the ascending aorta.

PubMed

Buz, Semih; Pasic, Miralem; Unbehaun, Axel; Drews, Thorsten; Dreysse, Stephan; Kukucka, Marian; Mladenow, Alexander; Hetzer, Roland

2011-08-01

In patients with calcification of the ascending aorta, postoperative stroke and mortality rates remain high after conventional aortic valve replacement, but the results of trans-apical aortic valve implantation in these patients are not known. We evaluate the outcome of trans-apical aortic valve implantation in patients with severely calcified ascending aorta in a single center with expanded procedural experience. Between April 2008 and July 2010, 258 patients underwent trans-apical aortic valve implantation using Edwards Sapien valve. By computed tomography (CT) scan, we identified 46 (18%) patients with severe calcification of the ascending aorta (16 with porcelain aorta and 30 with severe, but not complete, calcification). Of 46 patients (mean age 77 ± 10 years, range 63-90 years; EuroSCORE (European System for Cardiac Operative Risk Evaluation) 45 ± 22%; STS (Society of Thoracic Surgeons) score 23 ± 13) with calcified aorta, 15 received 23-mm valves and 31 patients 26-mm valves. Primary valve implantation was successful in 44 patients and a second valve was implanted (valve-in-valve) in two. Six patients underwent concomitant interventions (three elective percutaneous coronary intervention (PCI), one off-pump coronary artery bypass (OPCAB), one tricuspid valve reconstruction, and one left-ventricular (LV) aneurysmectomy). The final procedural results showed valve incompetence (trace or grade 1) in 17 (37%) patients and paravalvular leak in 15 (32.6%) (trace in 10 and grade 1 in five). There was no 30-day mortality. Postoperatively, cranial CT showed new cerebral ischemia areas in three patients (6.2%), but only one patient (2.1%) experienced postoperative neurological deficit (temporary aphasia). Survival at 6 and 12 months was 88% and 85.2%, respectively. Trans-apical aortic valve implantation can be performed safely in patients with aortic valve stenosis and severe calcification of the ascending aorta. Copyright © 2010 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.

Argon plasma coagulation in the right and left colon: safety-risk profile of the 60W-1.2 l/min setting.

PubMed

Panos, Marios Z; Koumi, Andriani

2014-05-01

The 40W-0.8 l/min setting is widely recommended for argon plasma coagulation (APC) in the right colon. Until March 2012, we used the 60W-1.2 l/min setting for all sites of the colon. By auditing our experience, we assessed the safety-risk profile of the 60W-1.2 l/min setting in the right and left colon. All cases treated with APC by a single endoscopist, using the 60W-1.2 l/min setting for all sites of the colon between October 2001 and December 2007 were identified retrospectively and site, type, number of lesions, and complications were recorded. Between January 2008 and March 2012, information was recorded prospectively. In the retrospective audit, 290 lesions (101 cecum/ascending, 120 sigmoid/descending, 69 transverse) were treated in 241 patient endoscopies. There were no perforations. In the prospective audit, 156 lesions (83 cecum/ascending, 47 sigmoid/descending, 26 transverse) were treated in 132 patient endoscopies. There was 1/83 (1.2%) perforation in the cecum/ascending colon and none in the transverse or sigmoid/descending (n.s.). Combined, the results yield a cecal/ascending perforation rate of 1/153 (0.6%) patient endoscopies, 1/184 (0.5%) lesions treated and overall perforation rate for all sites of the colon of 1/373 (0.3%) patient endoscopies and 1/446 (0.2%) lesions. Post-polypectomy syndrome and delayed bleeding each occurred in 3/373 (0.8%) patient endoscopies and 3/446 (0.7%) lesions. There were no deaths. In the cecum and ascending colon, the APC perforation rate at the 60W-1.2 l/min setting was no higher than in the left colon and is similar to that reported in previously published series. Therefore, it appears safe, provided the precautions we describe are strictly followed.

77 FR 14951 - Delegations of Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-14

... reflect changes in the coordination of Departmental remote sensing activities. These responsibilities are... responsible for coordinating USDA remote sensing activities (7 CFR 2.29(a)(6)). Within the Office of the Chief... Outlook Board (WAOB) (7 CFR 2.72(a)(4)). WAOB coordinates USDA remote sensing activities by chairing the...

Active and Passive Remote Sensing of Ice.

DTIC Science & Technology

1985-01-01

This is a report on the progress that has been made in the study of active and passive remote sensing of ice during the period of August 1, 1984...active and passive microwave remote sensing , (2) used the strong fluctuation theory and the fluctuation-dissipation theorem to calculate the brightness

Mechanisms controlling nucleic acid-sensing Toll-like receptors.

PubMed

Miyake, Kensuke; Shibata, Takuma; Ohto, Umeharu; Shimizu, Toshiyuki; Saitoh, Shin-Ichiroh; Fukui, Ryutaro; Murakami, Yusuke

2018-03-08

Nucleic acid (NA)-sensing Toll-like receptors (TLRs) respond to DNA/RNA derived from pathogens and dead cells. Structural studies have revealed a variety of molecular mechanisms by which TLRs sense NAs. Double-stranded RNA and single-stranded DNA directly bind to TLR3 and TLR9, respectively, whereas TLR7 and TLR8 bind to nucleosides and oligoribonucleotides derived from RNAs. Activation of ligand-bound TLRs is influenced by the functional status of TLRs. Proteolytic cleavage of NA-sensing TLRs enables ligand-dependent TLR dimerization. Trafficking of ligand-activated TLRs in endosomal and lysosomal compartments is requisite for production of type I interferons. Activation of NA-sensing TLRs is required for the control of viruses such as herpes simplex virus and endogenous retroviruses. On the other hand, excessive activation of NA-sensing TLRs drives disease progression in a variety of inflammatory diseases including systemic lupus erythematosus, heart failure, arthritis and non-alcoholic steatohepatitis. NA-sensing TLRs are targets for therapeutic intervention in these diseases. We here focus on our recent progresses in our understanding of NA-sensing TLRs.

Ascending Facial Necrotizing Fasciitis in a Patient Taking a Bisphosphonate.

PubMed

Kim, Dong Hwi; Lee, Ji Sung; Pyo, Sung Woon; Lee, Jung Ho

2017-02-01

Facial necrotizing fasciitis (NF) is a rare fulminant infection of the soft and connective tissues that spreads along the fascial planes of the face. Its origins most commonly involve odontogenic infection and it is usually associated with a history of dentoalveolar surgery, such as tooth extraction or implant placement. We present a case of ascending facial NF with odontogenic origin in a patient taking a bisphosphonate. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

[Fatal outcome of bilateral pulmonary embolism combined with ascending varicophlebitis of the lower limb: case report].

PubMed

Nagy, Imre; Skribek, Levente; Dienes, Anna Barbara; Rédei, Csaba; Tar, Márton

2015-04-19

The authors review the history and risk factors of thrombophlebitis of the lower limb, and describe the main points of surgical and conservative treatment of varicophlebitis. They present the case of a 71-year-old woman who had ascending varicophlebitis and bilateral pulmonary embolism. The authors draw attention to important points: patients must be followed after phlebitis of the lower limb, and their thrombotic factors must be examined to prevent the new thromboembolic events.

Huge ascending aortic aneurysm with an intraluminal thrombus in an embolic event-free patient

PubMed Central

Parato, Vito Maurizio; Pezzuoli, Franco; Labanti, Benedetto; Baboci, Arben

2015-01-01

We present a case of an 87-year-old male patient with a huge ascending aortic aneurysm, filled by a huge thrombus most probably due to previous dissection. This finding was detected by two-dimensional transthoracic echocardiography and contrast-enhanced computed tomography (CT) angiography scan. The patient refused surgical treatment and was medically treated. Despite the huge and mobile intraluminal thrombus, the patient remained embolic event-free up to 6 years later, and this makes the case unique. PMID:25838924

The Elephant in the Room: Religious Extremism in the Israeli-Palestinian Conflict

DTIC Science & Technology

2006-03-01

86 Kook, Orot, 99; also, see Is. 2:4, JPS. 87 Aran, 331. 88 Ibid. 89 Ehud Sprinzak, The Ascendance of Israel’s Radical Right . (Oxford...corroborated the existence of “hundreds of thousands of Israelis who share the beliefs and orientations of the radical right , almost all,” he said, were...Conflict, 5th ed. (New York: St. Martin’s, 2004). Sprinzak, Ehud. The Ascendance of Israel’s Radical Right . (Oxford; New York: Oxford University Press

Anatomy of the bovine ascending aorta and brachiocephalic artery found unfavorable for total artificial heart implant.

PubMed

Karimov, Jamshid H; Sunagawa, Gengo; Such, Kimberly A; Sale, Shiva; Golding, Leonard A R; Moazami, Nader; Fukamachi, Kiyotaka

2015-12-01

The biocompatibility assessment of the Cleveland Clinic continuous-flow total artificial heart is an important part of the device developmental program. Surgical and postoperative management are key factors in achieving optimal outcomes. However, the presence of vascular anatomical abnormalities in experimental animal models is often unpredictable and may worsen the expected outcomes. We report a technical impediment encountered during total artificial heart implantation complicated by unfavorable bovine anatomy of the ascending aorta and brachiocephalic arterial trunk.

Computed tomography findings mimicking appendicitis as a manifestation of colorectal cancer☆

PubMed Central

Watchorn, Richard E.; Poder, Liina; Wang, Zhen J.; Yeh, Benjamin M.; Webb, Emily M.; Coakley, Fergus V.

2009-01-01

The primary computed tomography (CT) signs of appendicitis can also be seen with other inflammatory or neoplastic processes. We report on two cases in which appendiceal dilatation and peri-appendiceal fluid or stranding were the dominant imaging manifestations of colorectal carcinoma in the ascending colon. This study highlights the need to closely examine the ascending colon in patients with a suspected CT diagnosis of acute appendicitis, since these findings may be secondary to an inconspicuous colorectal carcinoma. PMID:19857802

Salicylate-induced changes in auditory thresholds of adolescent and adult rats.

PubMed

Brennan, J F; Brown, C A; Jastreboff, P J

1996-01-01

Shifts in auditory intensity thresholds after salicylate administration were examined in postweanling and adult pigmented rats at frequencies ranging from 1 to 35 kHz. A total of 132 subjects from both age levels were tested under two-way active avoidance or one-way active avoidance paradigms. Estimated thresholds were inferred from behavioral responses to presentations of descending and ascending series of intensities for each test frequency value. Reliable threshold estimates were found under both avoidance conditioning methods, and compared to controls, subjects at both age levels showed threshold shifts at selective higher frequency values after salicylate injection, and the extent of shifts was related to salicylate dose level.

Health-related quality of life, sense of coherence and leisure-time physical activity in women after an acute myocardial infarction.

PubMed

Løvlien, Mona; Mundal, Liv; Hall-Lord, Marie-Louise

2017-04-01

To examine the relationship between leisure-time physical activity, health-related quality of life and sense of coherence in women after an acute myocardial infarction, and further to investigate whether these aspects were associated with age. Physical activity and health-related quality of life are vital aspects for patients after an acute myocardial infarction. Cross-sectional. All eligible women diagnosed with acute myocardial infarction received a postal questionnaire two to three months after hospital discharge, and 142 women were included. To measure health-related quality of life and sense of coherence, The MacNew Heart disease questionnaire and the Sense of coherence-13 scale was used. Respondents reporting at least one type of physical activity had significantly higher health-related quality of life as compared to respondents reporting no kind of physical activity. Respondents reporting physical activity for at least 30 minutes twice a week had significantly higher health-related quality of life scores than respondents being active less than twice a week. A weak association was found between physical activity level and sense of coherence. Reduction in physical activity after the acute myocardial infarction was associated with reduced health-related quality of life and sense of coherence. Sense of coherence was significantly associated with age, as respondents 75 years and older had significantly higher scores than respondents younger than 75 years. Physical activity, even at a low level, is significantly associated with increased health-related quality of life and to some extent to sense of coherence. Tailoring women after an acute myocardial infarction about lifestyle changes must include knowledge about the benefits of leisure-time physical activity, and that even a small amount of activity is associated with a better health-related quality of life. The utmost important assignment is to motivate the women for regular physical activity in their leisure-time. Older women need special attention. © 2016 John Wiley & Sons Ltd.

Basolateral LPS inhibits NHE3 and HCO3− absorption through TLR4/MyD88-dependent ERK activation in medullary thick ascending limb

PubMed Central

Watts, Bruns A.; George, Thampi; Sherwood, Edward R.

2011-01-01

Sepsis is associated with defects in renal tubule function, but the underlying mechanisms are incompletely understood. Recently, we demonstrated that Gram-negative bacterial lipopolysaccharide (LPS) inhibits HCO3− absorption in the medullary thick ascending limb (MTAL) through activation of Toll-like receptor 4 (TLR4). Here, we examined the mechanisms responsible for inhibition of HCO3− absorption by basolateral LPS. Adding LPS to the bath decreased HCO3− absorption by 30% in rat and mouse MTALs perfused in vitro. The inhibition of HCO3− absorption was eliminated by the mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK)/ERK inhibitors U0126 and PD98059. LPS induced a rapid (<15 min) and sustained (up to 60 min) increase in ERK phosphorylation in microdissected MTALs that was blocked by PD98059. The effects of basolateral LPS to activate ERK and inhibit HCO3− absorption were eliminated in MTALs from TLR4−/− and myeloid differentiation factor 88 (MyD88)−/− mice but were preserved in MTALs from TIR (Toll/interleukin-1 receptor) domain-containing adapter-inducing interferon-β (Trif)−/− mice. Basolateral LPS decreased apical Na+/H+ exchanger 3 NHE3 activity through a decrease in maximal velocity (Vmax). The inhibition of NHE3 by LPS was eliminated by MEK/ERK inhibitors. LPS inhibited HCO3− absorption despite the presence of physiological stimuli that activate ERK in the MTAL. We conclude that basolateral LPS inhibits HCO3− absorption in the MTAL through activation of a TLR4/MyD88/MEK/ERK pathway coupled to inhibition of NHE3. These studies identify NHE3 as a target of TLR4 signaling in the MTAL and show that bacterial molecules can impair the absorptive functions of renal tubules through inhibition of this exchanger. The ERK pathway links TLR4 to downstream modulation of ion transport proteins and represents a potential target for treatment of sepsis-induced renal tubule dysfunction. PMID:21881005

Zone zero thoracic endovascular aortic repair: A proposed modification to the classification of landing zones.

PubMed

Roselli, Eric E; Idrees, Jay J; Johnston, Douglas R; Eagleton, Matthew J; Desai, Milind Y; Svensson, Lars G

2018-04-01

Endovascular stent-grafting provides an alternative treatment option for high-risk patients with ascending aortic disease. The feasibility of this approach has been demonstrated before. We assess the updated experience with ascending thoracic endovascular aortic repair and propose a modification of the landing zone classification based on the outcomes. From 2006 to 2016, 39 patients deemed very high risk for open replacement underwent endovascular repair of ascending aorta for acute type A dissection (12, 31%), intramural hematoma (2, 5%), pseudoaneurysm (22, 56%), and chronic dissection suture line entry tear (3, 8%). Ascending thoracic endovascular aortic repair was performed in 36 patients. In 3 patients with pseudoaneurysm, occluder devices were used. Computed tomography imaging analysis was performed, and the extent of aortic pathology was designated by segmental proximity to the left ventricle. Segmental anatomy of the proximal aorta was designed as zone 0A from the annulus to the distal margin of highest coronary, 0B extends from above the coronary to the distal margin of right pulmonary artery, and 0C extends from the right pulmonary artery border to the innominate artery. Multivariable time to event Cox regression analysis was performed to predict mortality, and long-term survival was estimated using the Kaplan-Meier method. Operative mortality was 13%; all 5 deaths occurred after emergency ascending thoracic endovascular aortic repair for type A dissection. Other complications included stroke in 4 patients (10%), myocardial infarction in 2 patients (5%), tracheostomy in 2 patients (5%), and dialysis in 2 patients (5%). In patients with acute type A dissection, the ascending pathology extended into zone 0A in 10 (71%) and 0B in 4 (29%). Among those with pseudoaneurysm, the location of the defect was in 0B in 11 (50%), 0C in 10 (45%), and 0A in 1. Among the patients with chronic dissection, the defect was located in 0C in all 3 (100%). After multivariable adjustment, Cox regression predicted significantly higher hazard of mortality with disease involving zone 0A versus 0C (P = .020) and older age (P = .026). Kaplan-Meier estimate of survival was also significantly worse in patients with disease extension into 0A versus 0C (P = .0018). At 30 days, 1 year, and 5 years, the overall survival was 81%, 74%, and 64% and freedom from reintervention was 85%, 77%, and 68%, respectively. The modified zone zero classification is useful for characterizing extent of ascending aortic pathology and assessing prognosis. Location of the defect varies by pathology, and the presence of 0A disease predicts worse outcomes. Design of endovascular devices should be tailored to the aortic pathology and zone characteristics. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Conceptions of scientific literacy: Reactionaries in ascendency in the state of Victoria

NASA Astrophysics Data System (ADS)

Cross, Rober

1995-06-01

Schooling as much as any other social activity is determined by ideology. The introduction of the Victorian Curriculum & Standards Framework is a case in point. The alliance between the new Victorian State government and traditionalists has “reformed” the schooling of science. Evidence is presented that points to a return to a conception of scientific literacy in which the central mythology of value-free science is the guiding principle. Here is a vision for an “educated” Australia, which begs the question: Whose Australia?

Correlation of neural activity with behavioral kinematics reveals distinct sensory encoding and evidence accumulation processes during active tactile sensing.

PubMed

Delis, Ioannis; Dmochowski, Jacek P; Sajda, Paul; Wang, Qi

2018-07-15

Many real-world decisions rely on active sensing, a dynamic process for directing our sensors (e.g. eyes or fingers) across a stimulus to maximize information gain. Though ecologically pervasive, limited work has focused on identifying neural correlates of the active sensing process. In tactile perception, we often make decisions about an object/surface by actively exploring its shape/texture. Here we investigate the neural correlates of active tactile decision-making by simultaneously measuring electroencephalography (EEG) and finger kinematics while subjects interrogated a haptic surface to make perceptual judgments. Since sensorimotor behavior underlies decision formation in active sensing tasks, we hypothesized that the neural correlates of decision-related processes would be detectable by relating active sensing to neural activity. Novel brain-behavior correlation analysis revealed that three distinct EEG components, localizing to right-lateralized occipital cortex (LOC), middle frontal gyrus (MFG), and supplementary motor area (SMA), respectively, were coupled with active sensing as their activity significantly correlated with finger kinematics. To probe the functional role of these components, we fit their single-trial-couplings to decision-making performance using a hierarchical-drift-diffusion-model (HDDM), revealing that the LOC modulated the encoding of the tactile stimulus whereas the MFG predicted the rate of information integration towards a choice. Interestingly, the MFG disappeared from components uncovered from control subjects performing active sensing but not required to make perceptual decisions. By uncovering the neural correlates of distinct stimulus encoding and evidence accumulation processes, this study delineated, for the first time, the functional role of cortical areas in active tactile decision-making. Copyright © 2018 Elsevier Inc. All rights reserved.

The Effect of Active-Participant Experiments upon the Skills of Nursery Class Students to Recognize Measuring Instruments

ERIC Educational Resources Information Center

Sapsaglam, Ozkan; Bozdogan, Aykut Emre

2017-01-01

Preschool children learn through their senses. Children learn language, daily life skills, concepts and many other things through their senses. Thus, preschool educational environments and preschool educational activities should stimulate children's senses. In this context, preschool science activities and experiments have positive effects upon…

ZBP1/DAI ubiquitination and sensing of influenza vRNPs activate programmed cell death

PubMed Central

Kuriakose, Teneema; Malireddi, R.K. Subbarao; Mishra, Ashutosh

2017-01-01

Innate sensing of influenza virus infection induces activation of programmed cell death pathways. We have recently identified Z-DNA–binding protein 1 (ZBP1) as an innate sensor of influenza A virus (IAV). ZBP1-mediated IAV sensing is critical for triggering programmed cell death in the infected lungs. Surprisingly, little is known about the mechanisms regulating ZBP1 activation to induce programmed cell death. Here, we report that the sensing of IAV RNA by retinoic acid inducible gene I (RIG-I) initiates ZBP1-mediated cell death via the RIG-I–MAVS–IFN-β signaling axis. IAV infection induces ubiquitination of ZBP1, suggesting potential regulation of ZBP1 function through posttranslational modifications. We further demonstrate that ZBP1 senses viral ribonucleoprotein (vRNP) complexes of IAV to trigger cell death. These findings collectively indicate that ZBP1 activation requires RIG-I signaling, ubiquitination, and vRNP sensing to trigger activation of programmed cell death pathways during IAV infection. The mechanism of ZBP1 activation described here may have broader implications in the context of virus-induced cell death. PMID:28634194

Large-scale patterns formed by solar active regions during the ascending phase of cycle 21

NASA Astrophysics Data System (ADS)

Gaizauskas, V.; Harvey, K. L.; Harvey, J. W.; Zwaan, C.

1983-02-01

Synoptic maps of photospheric magnetic fields prepared at the Kitt Peak National Observatory are used in investigating large-scale patterns in the spatial and temporal distribution of solar active regions for 27 solar rotations between 1977 and 1979. The active regions are found to be distributed in 'complexes of activity' (Bumba and Howard, 1965). With the working definition of a complex of activity based on continuity and proximity of the constituent active regions, the phenomenology of complexes is explored. It is found that complexes of activity form within one month and that they are typically maintained for 3 to 6 solar rotations by fresh injections of magnetic flux. During the active lifetime of a complex of activity, the total magnetic flux in the complex remains steady to within a factor of 2. The magnetic polarities are closely balanced, and each complex rotates about the sun at its own special, constant rate. In certain cases, the complexes form two diverging branches.

Some steps toward a central theory of ecosystem dynamics.

PubMed

Ulanowicz, Robert E

2003-12-01

Ecology is said by many to suffer for want of a central theory, such as Newton's laws of motion provide for classical mechanics or Schroedinger's wave equation provides for quantum physics. From among a plurality of contending laws to govern ecosystem behavior, the principle of increasing ascendency shows some early promise of being able to address the major questions asked of a theory of ecosystems, including, "How do organisms come to be distributed in time and space?, what accounts for the log-normal distribution of species numbers?, and how is the diversity of ecosystems related to their stability, resilience and persistence?" While some progress has been made in applying the concept of ascendency to the first issue, more work is needed to articulate exactly how it relates to the latter two. Accordingly, seven theoretical tasks are suggested that could help to establish these connections and to promote further consideration of the ascendency principle as the kernel of a theory of ecosystems.

Long Term Mean Local Time of the Ascending Node Prediction

NASA Technical Reports Server (NTRS)

McKinley, David P.

2007-01-01

Significant error has been observed in the long term prediction of the Mean Local Time of the Ascending Node on the Aqua spacecraft. This error of approximately 90 seconds over a two year prediction is a complication in planning and timing of maneuvers for all members of the Earth Observing System Afternoon Constellation, which use Aqua's MLTAN as the reference for their inclination maneuvers. It was determined that the source of the prediction error was the lack of a solid Earth tide model in the operational force models. The Love Model of the solid Earth tide potential was used to derive analytic corrections to the inclination and right ascension of the ascending node of Aqua's Sun-synchronous orbit. Additionally, it was determined that the resonance between the Sun and orbit plane of the Sun-synchronous orbit is the primary driver of this error. The analytic corrections have been added to the operational force models for the Aqua spacecraft reducing the two-year 90-second error to less than 7 seconds.

"Optimal" application of ventilatory assist in Cheyne-Stokes respiration: a simulation study.

PubMed

Khoo, M C; Benser, M E

2005-01-01

Although a variety of ventilator therapies have been employed to treat Cheyne-Stokes respiration (CSR), these modalities do not completely eliminate CSR. As well, most current strategies require that ventilatory assist be provided continuously. We used a computer model of the respiratory control system to determine whether a ventilatory assist strategy could be found that would substantially reduce the severity of CSR while minimizing the application of positive airway pressure. We assessed the effects of different levels of ventilatory assist applied during breaths that fell below selected hypopneic thresholds. These could be applied during the descending, ascending, or both phases of the CSR cycle. We found that ventilatory augmentation equal to 30-40% of eupneic drive, applied whenever ventilation fell below 70% of the eupneic level during the ascending or descending-and-ascending phases of CSR led to the greatest regularization of breathing with minimal ventilator intervention. Application of ventilatory assist during the descending phase produced little effect.

The herbal medicine Dai-Kenchu-To directly stimulates colonic motility.

PubMed

Kawahara, Hidejiro; Yanaga, Katsuhiko

2009-01-01

Dai-kenchu-to (DKT) has attracted attention as a drug that improves the symptoms of postoperative ileus. However, the detailed mechanism of its action still remains unknown. The effect of DKT on colonic motility was herein evaluated using an original method. Eight healthy male volunteers who understood the purpose of this study were enrolled. Dai-kenchu-to (5 g) was dissolved in saline and administered into the cecum using a colonoscope until the ascending colon became distended. Colonic motility was observed by extrasomatic ultrasonography for 30 min. Colonic contractions were observed 129.4 (range 110-145) s after DKT administration into the ascending colon. Every segment in the right colon divided by the crescentic folds contracted independently. On the other hand, no colonic contractions were observed in the right colon after saline solution alone was administered to the ascending colon. In conclusion, DKT stimulates colonic motility immediately after administration, in the same manner as it does for the upper alimentary tract.

Metastasis to the appendix from adenocarcinoma of the ascending colon: A case report.

PubMed

Li, Yingjie; Li, Mingshan; Li, Xiaoxia; Sang, Haiquan

2017-03-01

Metastasis of cancer cells involves shedding from the primary tumor through various means to distant tissues and organs with continued growth and formation of new metastatic tumors of the same cancer type as the original tumor. The common sites for colon cancer metastases include the pelvis, retroperitoneal lymph nodes, liver, and lungs; Colon cancer metastases to the appendix are rare, as reported in this case. A 45-year-old man was admitted to our department with a 24-hour history of abdominal distension and incomplete obstruction. Colonoscopy showed an elevated lesion in the ascending colon and the pathologic diagnosis was adenocarcinoma. This patient underwent a radical right hemi-colectomy. The post-operative pathologic examination revealed metastatic adenocarcinoma in all layers of the appendix, especially the muscularis mucosae. The diagnosis was adenocarcinoma of the ascending colon (pT4bN2bM0 stage IIIC) with metastatic adenocarcinoma of the appendix. An absent right colic artery with lymph node fusion might increase the risk of appendiceal cancer metastasis.

Novel techniques for optical sensor using single core multi-layer structures for electric field detection

NASA Astrophysics Data System (ADS)

Ali, Amir R.; Kamel, Mohamed A.

2017-05-01

This paper studies the effect of the electrostriction force on the single optical dielectric core coated with multi-layers based on whispering gallery mode (WGM). The sensing element is a dielectric core made of polymeric material coated with multi-layers having different dielectric and mechanical properties. The external electric field deforming the sensing element causing shifts in its WGM spectrum. The multi-layer structures will enhance the body and the pressure forces acting on the core of the sensing element. Due to the gradient on the dielectric permittivity; pressure forces at the interface between every two layers will be created. Also, the gradient on Young's modulus will affect the overall stiffness of the optical sensor. In turn the sensitivity of the optical sensor to the electric field will be increased when the materials of each layer selected properly. A mathematical model is used to test the effect for that multi-layer structures. Two layering techniques are considered to increase the sensor's sensitivity; (i) Pressure force enhancement technique; and (ii) Young's modulus reduction technique. In the first technique, Young's modulus is kept constant for all layers, while the dielectric permittivity is varying. In this technique the results will be affected by the value dielectric permittivity of the outer medium surrounding the cavity. If the medium's dielectric permittivity is greater than that of the cavity, then the ascending ordered layers of the cavity will yield the highest sensitivity (the core will have the smallest dielectric permittivity) to the applied electric field and vice versa. In the second technique, Young's modulus is varying along the layers, while the dielectric permittivity has a certain constant value per layer. On the other hand, the descending order will enhance the sensitivity in the second technique. Overall, results show the multi-layer cavity based on these techniques will enhance the sensitivity compared to the typical polymeric optical sensor.

Objective assessment of physical activity and sedentary behaviour in knee osteoarthritis patients - beyond daily steps and total sedentary time.

PubMed

Sliepen, Maik; Mauricio, Elsa; Lipperts, Matthijs; Grimm, Bernd; Rosenbaum, Dieter

2018-02-23

Knee osteoarthritis patients may become physically inactive due to pain and functional limitations. Whether physical activity exerts a protective or harmful effect depends on the frequency, intensity, time and type (F.I.T.T.). The F.I.T.T. dimensions should therefore be assessed during daily life, which so far has hardly been feasible. Furthermore, physical activity should be assessed within subgroups of patients, as they might experience different activity limitations. Therefore, this study aimed to objectively describe physical activity, by assessing the F.I.T.T. dimensions, and sedentary behaviour of knee osteoarthritis patients during daily life. An additional goal was to determine whether activity events, based on different types and durations of physical activity, were able to discriminate between subgroups of KOA patients based on risk factors. Clinically diagnosed knee osteoarthritis patients (according to American College of Rheumatology criteria) were monitored for 1 week with a tri-axial accelerometer. Furthermore, they performed three functional tests and completed the Knee Osteoarthritis Outcome Score. Physical activity levels were described for knee osteoarthritis patients and compared between subgroups. Sixty-one patients performed 7303 mean level steps, 319 ascending and 312 descending steps and 601 bicycle crank revolutions per day. Most waking hours were spent sedentary (61%), with 4.6 bouts of long duration (> 30 min). Specific events, particularly ascending and descending stairs/slopes, brief walking and sedentary bouts and prolonged walking bouts, varied between subgroups. From this sample of KOA patients, the most common form of activity was level walking, although cycling and stair climbing activities occurred frequently, highlighting the relevance of distinguishing between these types of PA. The total active time encompassed a small portion of their waking hours, as they spent most of their time sedentary, which was exacerbated by frequently occurring prolonged bouts. In this study, event-based parameters, such as stair climbing or short bouts of walking or sedentary time, were found more capable of discriminating between subgroups of KOA patients compared to overall levels of PA and sedentary time. Thereby, subtle limitations in physical behaviour of KOA-subgroups were revealed, which might ultimately be targeted in rehabilitation programs. German Clinical Trials Registry under ' DRKS00008735 ' at 02.12.2015.

Mini-Bentall: An Interesting Approach for Selected Patients.

PubMed

Mikus, Elisa; Micari, Antonio; Calvi, Simone; Salomone, Maria; Panzavolta, Marco; Paris, Marco; Del Giglio, Mauro

Minimally invasive surgery through an upper hemisternotomy for aortic valve replacement has become the routine approach with excellent results. Actually, the same minimally invasive access is used for complex ascending aorta procedures only in few centers. We report our experience with minimally invasive approach for aortic valve and ascending aorta replacement using Bentall technique. From January 2010 to November 2015, a total of 238 patients received ascending aorta and aortic valve replacement using Bentall De Bono procedure at our institution. Low- and intermediate-risk patients underwent elective surgery with a minimally invasive approach. The "J"-shaped partial upper sternotomy was performed through a 6-cm skin incision from the notch to the third right intercostal space. Patients who had previous cardiac surgery or affected by active endocarditis were excluded. The study included 53 patients, 44 male (83 %) with a median age of 63 years [interquartile range (IQR), 51-73 years]. A bicuspid aortic valve was diagnosed in 27 patients (51%). A biological Bentall using a pericardial Mitroflow or Crown bioprosthesis implanted in a Valsalva graft was performed in 49 patents. The remaining four patients were treated with a traditional mechanical conduit. Median cardiopulmonary bypass time and median cross-clamp time were respectively 84 (IQR, 75-103) minutes and 73 (IQR, 64-89) minutes. Hospital mortality was zero as well as 30-day mortality. Median intensive care unit and hospital stay were 1.9 and 8 days, respectively. The study population compared with patients treated with standard full sternotomy and similar preoperative characteristics showed similar results in terms of postoperative outcomes with a slightly superiority of minimally invasive group mainly regarding operative times, incidence of atrial fibrillation, and postoperative ventilation times. A partial upper sternotomy is considered a safe option for aortic valve replacement. Our experience confirms that a minimally invasive approach using a partial upper J-shaped sternotomy can be a safe alternative approach to the standard in selected patients presenting with complex aortic root pathology.

Active and Passive Remote Sensing of Ice

DTIC Science & Technology

1993-01-26

92 4. TITLE AND SUBTITLE S. FUNDING NUMBERS Active and Passive Remote Sensing of Ice NO0014-89-J-l 107 6. AUTHOR(S) 425f023-08 Prof. J.A. Kong 7... REMOTE SENSING OF ICE Sponsored by: Department of the Navy Office of Naval Research Contract number: N00014-89-J-1107 Research Organization: Center for...J. A. Kong Period covered: October 1, 1988 - November 30, 1992 St ACTIVE AND PASSIVE REMOTE SENSING OF ICE FINAL REPORT This annual report covers

A resected case of medullary carcinoma of the ascending colon followed by infarction of the greater omentum mimicking anastomotic leakage.

PubMed

Wakasugi, Masaki; Kono, Hiroshi; Yasuhara, Yumiko; Tsujimura, Naoto; Nakahara, Yujiro; Matsumoto, Takashi; Takemoto, Hiroyoshi; Takachi, Ko; Nishioka, Kiyonori; Yoshida, Kyotaro; Oshima, Satoshi

2017-01-01

Medullary carcinoma is a rare type of colorectal adenocarcinoma, and omental infarction is a rare cause of acute abdomen. A 72-year-old woman underwent single-incision laparoscopic right hemicolectomy for ascending colon cancer. Pathological examination showed a medullary carcinoma (MC) of T4aN0M0 Stage IIB. Her postoperative course was uneventful, and she was discharged on postoperative day (POD) 6. From POD 7, she suffered from fever, and she returned to the hospital on POD 9. Plain computed tomography showed free air beside the anastomotic site around the elevated density of fat tissue and gallbladder wall thickening with a gallstone. Suspecting anastomotic leakage with acute cholecystitis, probe laparotomy was performed. Intraoperative observation confirmed omental infarction with acute cholecystitis, and no leakage was found at the anastomotic site. Therefore, the necrotic part of the greater omentum was resected, and cholecystectomy was performed. She has remained well, with no evidence of recurrent cancer during the 12 months of follow-up without chemotherapy after the surgery for MC of the ascending colon. MC should be distinguished from other more aggressive, non-glandular tumors of the colon because MC appears to have a better survival outcome than undifferentiated colon adenocarcinoma. Omental infarction should be considered in the differential diagnosis of acute abdomen after surgery. A rare case of medullary carcinoma of the ascending colon followed by infarction of the greater omentum mimicking anastomotic leakage is presented.

Biphasic Effects of Alcohol on Delay and Probability Discounting

PubMed Central

Bidwell, L. Cinnamon; MacKillop, James; Murphy, James G.; Grenga, Andrea; Swift, Robert M.; McGeary, John E.

2014-01-01

Delay discounting and probability discounting are behavioral economic indices of impulsive and risky decision making that have been associated with addictive behavior, but the acute biphasic effects of alcohol on these decision-making processes are not well understood. This study sought to investigate the biphasic effects of alcohol on delay and probability discounting across the ascending and descending limbs of the breath alcohol concentration (BAC) curve, which are respectively characterized by the stimulant and sedative effects of alcohol. Delay and probability discounting were measured at four time points (Baseline, Ascending, Descending, and Endpoint) across the BAC curve at two target alcohol doses (40 mg/dl and 80 mg/dl) in healthy adults (N = 23 and 27, for both doses, respectively). There was no significant effect of alcohol on delay discounting at either dose. Alcohol significantly affected probability discounting, such that reduced discounting for uncertain rewards was evident during the descending limb of the BAC curve at the lower dose (p<.05) and during both the ascending and descending limb of the BAC curve at the higher dose (p<.05). Thus, alcohol resulted in increased risky decision making, particularly during the descending limb which is primarily characterized by the sedative effects of alcohol. These findings suggest that the biphasic effects of alcohol across the ascending and descending limbs of the BAC have differential effects on behavior related to decision-making for probabilistic, but not delayed, rewards. Parallels to and distinctions from previous findings are discussed. PMID:23750692

Stair Descending Exercise Using a Novel Automatic Escalator: Effects on Muscle Performance and Health-Related Parameters

PubMed Central

Paschalis, Vassilis; Theodorou, Anastasios A.; Panayiotou, George; Kyparos, Antonios; Patikas, Dimitrios; Grivas, Gerasimos V.; Nikolaidis, Michalis G.; Vrabas, Ioannis S.

2013-01-01

A novel automatic escalator was designed, constructed and used in the present investigation. The aim of the present investigation was to compare the effect of two repeated sessions of stair descending versus stair ascending exercise on muscle performance and health-related parameters in young healthy men. Twenty males participated and were randomly divided into two equal-sized groups: a stair descending group (muscle-damaging group) and a stair ascending group (non-muscle-damaging group). Each group performed two sessions of stair descending or stair ascending exercise on the automatic escalator while a three week period was elapsed between the two exercise sessions. Indices of muscle function, insulin sensitivity, blood lipid profile and redox status were assessed before and immediately after, as well as at day 2 and day 4 after both exercise sessions. It was found that the first bout of stair descending exercise caused muscle damage, induced insulin resistance and oxidative stress as well as affected positively blood lipid profile. However, after the second bout of stair descending exercise the alterations in all parameters were diminished or abolished. On the other hand, the stair ascending exercise induced only minor effects on muscle function and health-related parameters after both exercise bouts. The results of the present investigation indicate that stair descending exercise seems to be a promising way of exercise that can provoke positive effects on blood lipid profile and antioxidant status. PMID:23437093

Organization of ascending spinal projections in Caiman crocodilus.

PubMed

Ebbesson, S O; Goodman, D C

1981-01-01

Ascending spinal projections in the caiman (Caiman crocodilus) were demonstrated with Nauta and Fink-Heimer methods following hemisections of the third spinal segment in a series of twelve animals. These results were compared with earlier data in the literature obtained from a turtle, a snake, and a lizard using the same experimental and histological procedures. The results show remarkable similarities considering that each species represents a different reptilian order with different evolutionary history and habitat. However, the caiman displays several important peculiarities. Although the dorsal funiculus of the caiman contains the largest number of ascending spinal projections of the four species examined, this funiculus has not differentiated into cuneate and gracile fasciculi as is the case in the tegu lizard. The ventro-lateral ascending spinal projections follow a fundamentally similar general morphologic pattern in the four species with only minor variations. The anatomical arrangement in the caiman and tegu lizard appears most similar in the high cervical and the medullary regions; however, this is not the case in midbrain and thalamic regions where considerably more extensive projections are seen in the caiman. In the caiman an extensive spinal connection to the ventro-lateral nucleus of the dorsal thalamus is present; this connection is reminiscent of the mammalian spinal projection to the ventro-basal complex. The caiman has in common with the other three reptilian species a small projection to another dorsal thalamic region that is apparently homologous to the mammalian intralaminar nuclei, which are the destination of the mammalian paleospinothalamic tract.

Effective connectivity of ascending and descending frontalthalamic pathways during sustained attention: Complex brain network interactions in adolescence.

PubMed

Jagtap, Pranav; Diwadkar, Vaibhav A

2016-07-01

Frontal-thalamic interactions are crucial for bottom-up gating and top-down control, yet have not been well studied from brain network perspectives. We applied network modeling of fMRI signals [dynamic causal modeling (DCM)] to investigate frontal-thalamic interactions during an attention task with parametrically varying levels of demand. fMRI was collected while subjects participated in a sustained continuous performance task with low and high attention demands. 162 competing model architectures were employed in DCM to evaluate hypotheses on bilateral frontal-thalamic connections and their modulation by attention demand, selected at a second level using Bayesian model selection. The model architecture evinced significant contextual modulation by attention of ascending (thalamus → dPFC) and descending (dPFC → thalamus) pathways. However, modulation of these pathways was asymmetric: while positive modulation of the ascending pathway was comparable across attention demand, modulation of the descending pathway was significantly greater when attention demands were increased. Increased modulation of the (dPFC → thalamus) pathway in response to increased attention demand constitutes novel evidence of attention-related gain in the connectivity of the descending attention pathway. By comparison demand-independent modulation of the ascending (thalamus → dPFC) pathway suggests unbiased thalamic inputs to the cortex in the context of the paradigm. Hum Brain Mapp 37:2557-2570, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

[Exoprosthetic repair of the ascending portion of the aorta: midterm results].

PubMed

Cherniavskiĭ, A M; Sirota, D A; Liashenko, M M; Al'sov, S A; Khvan, D S

The authors analyse herein their experience gained in performing the operation of exoprosthetic repair of the ascending portion of the aorta in patients presenting with an ascending aortic aneurysm. This is followed by assessing the results in the remote period. Over the period of follow up from 2012 to 2016 a total of 23 interventions were performed. The average duration of postoperative follow up amounted to 27±9.4 (2-40) months. In the remote period we managed to obtain the data for 20 (90.1%) patients. The patients were interviewed by means of either remote or face-to-face consultations during which we performed assessment of the dimensions of the thoracic portion of the aorta by the findings of MSCT angiography of the aorta. Health-related quality of life was evaluated by means of the Short Form Health Survey Questionnaire SF-36. No statistically significant changes of the aortic sizes were revealed in the remote period as compared with the findings at discharge from hospital. Neither were there repeat interventions related to the operation performed. According to the findings of the SF-36 questionnaire, patients mainly reported improved well-being as compared with that at discharge, including patients having endured coronary artery bypass grafting or prosthetic repair of the aortic valve. Experience shows that using the technique of exoprosthetic repair of the ascending portion of the aorta makes it possible to eliminate dilatation with satisfactory remote results. However, fuller and more reliable assessment of the results requires further studies.

Biphasic effects of alcohol as a function of circadian phase.

PubMed

Van Reen, Eliza; Rupp, Tracy L; Acebo, Christine; Seifer, Ronald; Carskadon, Mary A

2013-01-01

To assess how alcohol affects multiple sleep latency tests (MSLT) and subjective measures of stimulation/sedation when alcohol is given at different circadian phases. Twenty-seven healthy young adults (age 21-26 yr) were studied. Double-blind placebo and alcohol (vodka tonic targeting 0.05 g% concentration) beverages were each administered three times during the 20-h forced desynchrony protocol. Sleep latency tests and Biphasic Effects of Alcohol Scale (BAES) were administered on each forced desynchrony day. The outcome variables for this study include sleep onset latency (SOL) and stimulation and sedation value (from the BAES). Each outcome variable was associated with the ascending or descending limb of the breath alcohol concentration (BrAC) curve and assigned a circadian phase within a 90° bin. BrAC confirmed targeted maximal levels. Only outcome variables associated with the ascending and descending limb of the alcohol curve were analyzed for this article. Alcohol administered at a circadian time associated with greatest sleepiness showed longer SOL compared with placebo when measured on the ascending limb of the BrAC curve. We also found longer SOL with alcohol on the ascending limb of the BrAC curve in a circadian bin that favors greatest alertness. We observed shorter SOLs on the descending limb of the BrAC curve, but with no circadian phase interaction. The subjective data were partially consistent with the objective data. The physiologic findings in this study support the biphasic stimulating and sedating properties of alcohol, but limit the effect to specific circadian times.

Active Sensing System with In Situ Adjustable Sensor Morphology

PubMed Central

Nurzaman, Surya G.; Culha, Utku; Brodbeck, Luzius; Wang, Liyu; Iida, Fumiya

2013-01-01

Background Despite the widespread use of sensors in engineering systems like robots and automation systems, the common paradigm is to have fixed sensor morphology tailored to fulfill a specific application. On the other hand, robotic systems are expected to operate in ever more uncertain environments. In order to cope with the challenge, it is worthy of note that biological systems show the importance of suitable sensor morphology and active sensing capability to handle different kinds of sensing tasks with particular requirements. Methodology This paper presents a robotics active sensing system which is able to adjust its sensor morphology in situ in order to sense different physical quantities with desirable sensing characteristics. The approach taken is to use thermoplastic adhesive material, i.e. Hot Melt Adhesive (HMA). It will be shown that the thermoplastic and thermoadhesive nature of HMA enables the system to repeatedly fabricate, attach and detach mechanical structures with a variety of shape and size to the robot end effector for sensing purposes. Via active sensing capability, the robotic system utilizes the structure to physically probe an unknown target object with suitable motion and transduce the arising physical stimuli into information usable by a camera as its only built-in sensor. Conclusions/Significance The efficacy of the proposed system is verified based on two results. Firstly, it is confirmed that suitable sensor morphology and active sensing capability enables the system to sense different physical quantities, i.e. softness and temperature, with desirable sensing characteristics. Secondly, given tasks of discriminating two visually indistinguishable objects with respect to softness and temperature, it is confirmed that the proposed robotic system is able to autonomously accomplish them. The way the results motivate new research directions which focus on in situ adjustment of sensor morphology will also be discussed. PMID:24416094

Activation of the umami taste receptor (T1R1/T1R3) initiates the peristaltic reflex and pellet propulsion in the distal colon.

PubMed

Kendig, Derek M; Hurst, Norman R; Bradley, Zachary L; Mahavadi, Sunila; Kuemmerle, John F; Lyall, Vijay; DeSimone, John; Murthy, Karnam S; Grider, John R

2014-12-01

Intraluminal nutrients in the gut affect the peristaltic reflex, although the mechanism is not well defined. Recent evidence supports the presence of taste receptors and their signaling components in enteroendocrine cells, although their function is unclear. This study aimed to determine if nutrients modify colonic motility through activation of taste receptors. Colonic sections were immunostained for the umami taste receptor T1R1/T1R3, which mediates the response to umami ligands, such as monosodium glutamate (MSG), in taste cells. Ascending contraction, descending relaxation, and calcitonin gene-related peptide release were measured in three-chamber flat-sheet preparations of rat colon in response to MSG alone or with inosine 5'-monophosphate (IMP). Velocity of artificial fecal pellet propulsion was measured by video recording in guinea pig distal colon. T1R1/T1R3 receptors were present in enteroendocrine cells of colonic sections from human, rat, mouse, and guinea pig. MSG initiated ascending contraction and descending relaxation components of the peristaltic reflex and calcitonin gene-related peptide release in flat-sheet preparations. IMP augmented the MSG-induced effects, suggesting activation of T1R1/T1R3 receptors. In T1R1(-/-) mice, mucosal stroking, but not MSG, elicited a peristaltic reflex. Intraluminal perfusion of MSG enhanced the velocity of artificial fecal pellet propulsion, which was also augmented by IMP. Propulsion was also increased by l-cysteine, but not l-tryptophan, supporting a role of T1R1/T1R3 receptors. We conclude that T1R1/T1R3 activation by luminal MSG or l-cysteine elicits a peristaltic reflex and CGRP release and increases the velocity of pellet propulsion in distal colon. This mechanism may explain how nutrients regulate colonic propulsion. Copyright © 2014 the American Physiological Society.

Activation of the umami taste receptor (T1R1/T1R3) initiates the peristaltic reflex and pellet propulsion in the distal colon

PubMed Central

Kendig, Derek M.; Hurst, Norman R.; Bradley, Zachary L.; Mahavadi, Sunila; Kuemmerle, John F.; Lyall, Vijay; DeSimone, John; Murthy, Karnam S.

2014-01-01

Intraluminal nutrients in the gut affect the peristaltic reflex, although the mechanism is not well defined. Recent evidence supports the presence of taste receptors and their signaling components in enteroendocrine cells, although their function is unclear. This study aimed to determine if nutrients modify colonic motility through activation of taste receptors. Colonic sections were immunostained for the umami taste receptor T1R1/T1R3, which mediates the response to umami ligands, such as monosodium glutamate (MSG), in taste cells. Ascending contraction, descending relaxation, and calcitonin gene-related peptide release were measured in three-chamber flat-sheet preparations of rat colon in response to MSG alone or with inosine 5′-monophosphate (IMP). Velocity of artificial fecal pellet propulsion was measured by video recording in guinea pig distal colon. T1R1/T1R3 receptors were present in enteroendocrine cells of colonic sections from human, rat, mouse, and guinea pig. MSG initiated ascending contraction and descending relaxation components of the peristaltic reflex and calcitonin gene-related peptide release in flat-sheet preparations. IMP augmented the MSG-induced effects, suggesting activation of T1R1/T1R3 receptors. In T1R1−/− mice, mucosal stroking, but not MSG, elicited a peristaltic reflex. Intraluminal perfusion of MSG enhanced the velocity of artificial fecal pellet propulsion, which was also augmented by IMP. Propulsion was also increased by l-cysteine, but not l-tryptophan, supporting a role of T1R1/T1R3 receptors. We conclude that T1R1/T1R3 activation by luminal MSG or l-cysteine elicits a peristaltic reflex and CGRP release and increases the velocity of pellet propulsion in distal colon. This mechanism may explain how nutrients regulate colonic propulsion. PMID:25324508

Oxidative stress in deep scattering layers: Heat shock response and antioxidant enzymes activities of myctophid fishes thriving in oxygen minimum zones

NASA Astrophysics Data System (ADS)

Lopes, Ana Rita; Trübenbach, Katja; Teixeira, Tatiana; Lopes, Vanessa M.; Pires, Vanessa; Baptista, Miguel; Repolho, Tiago; Calado, Ricardo; Diniz, Mário; Rosa, Rui

2013-12-01

Diel vertical migrators, such as myctophid fishes, are known to encounter oxygen minimum zones (OMZ) during daytime in the Eastern Pacific Ocean and, therefore, have to cope with temperature and oxidative stress that arise while ascending to warmer, normoxic surface waters at night-time. The aim of this study was to investigate the antioxidant defense strategies and heat shock response (HSR) in two myctophid species, namely Triphoturus mexicanus and Benthosema panamense, at shallow and warm surface waters (21 kPa, 20-25 °C) and at hypoxic, cold (≤1 kPa, 10 °C) mesopelagic depths. More specifically, we quantified (i) heat shock protein concentrations (HSP70/HSC70) (ii) antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], and (iii) lipid peroxidation [malondialdehyde (MDA) levels]. HSP70/HSC70 levels increased in both myctophid species at warmer, well-oxygenated surface waters probably to prevent cellular damage (oxidative stress) due to increased oxygen demand under elevated temperatures and reactive oxygen species (ROS) formation. On the other hand, CAT and GST activities were augmented under hypoxic conditions, probably as preparatory response to a burst of oxyradicals during the reoxygenation phase (while ascending). SOD activity decreased under hypoxia in B. panamense, but was kept unchanged in T. mexicanus. MDA levels in B. panamense did not change between the surface and deep-sea conditions, whereas T. mexicanus showed elevated MDA and HSP70/HSC70 concentrations at warmer surface waters. This indicated that T. mexicanus seems to be not so well tuned to temperature and oxidative stress associated to diel vertical migrations. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how different species might respond to the impacts of environmental stressors (e.g. expanding mesopelagic hypoxia) coupled with global climate change.

From genetics to response to injury: vascular smooth muscle cells in aneurysms and dissections of the ascending aorta.

PubMed

Michel, Jean-Baptiste; Jondeau, Guillaume; Milewicz, Dianna M

2018-03-15

Vascular smooth muscle cells (vSMCs) play a crucial role in both the pathogenesis of Aneurysms and Dissections of the ascending thoracic aorta (TAAD) in humans and in the associated adaptive compensatory responses, since thrombosis and inflammatory processes are absent in the majority of cases. Aneurysms and dissections share numerous characteristics, including aetiologies and histopathological alterations: vSMC disappearance, medial areas of mucoid degeneration, and extracellular matrix (ECM) breakdown. Three aetiologies predominate in TAAD in humans: (i) genetic causes in heritable familial forms, (ii) an association with bicuspid aortic valves, and (iii) a sporadic degenerative form linked to the aortic aging process. Genetic forms include mutations in vSMC genes encoding for molecules of the ECM or the TGF-β pathways, or participating in vSMC tone. On the other hand, aneurysms and dissections, whatever their aetiologies, are characterized by an increase in wall permeability leading to transmural advection of plasma proteins which could interact with vSMCs and ECM components. In this context, blood-borne plasminogen appears to play an important role, because its outward convection through the wall is increased in TAAD, and it could be converted to active plasmin at the vSMC membrane. Active plasmin can induce vSMC disappearance, proteolysis of adhesive proteins, activation of MMPs and release of TGF-β from its ECM storage sites. Conversely, vSMCs could respond to aneurysmal biomechanical and proteolytic injury by an epigenetic phenotypic switch, including constitutional overexpression and nuclear translocation of Smad2 and an increase in antiprotease and ECM protein synthesis. In contrast, such an epigenetic phenomenon is not observed in dissections. In this context, dysfunction of proteins involved in vSMC tone are interesting to study, particularly in interaction with plasma protein transport through the wall and TGF-β activation, to establish the relationship between these dysfunctions and ECM proteolysis.

Classification of occupational activity categories using accelerometry: NHANES 2003-2004.

PubMed

Steeves, Jeremy A; Tudor-Locke, Catrine; Murphy, Rachel A; King, George A; Fitzhugh, Eugene C; Harris, Tamara B

2015-06-30

An individual's occupational activity (OA) may contribute significantly to daily physical activity (PA) and sedentary behavior (SB). However, there is little consensus about which occupational categories involve high OA or low OA, and the majority of categories are unclassifiable with current methods. The purpose of this study was to present population estimates of accelerometer-derived PA and SB variables for adults (n = 1112, 20-60 years) working the 40 occupational categories collected during the 2003-2004 National Health and Nutrition Examination Survey (NHANES). ActiGraph accelerometer-derived total activity counts/day (TAC), activity counts/minute, and proportion of wear time spent in moderate-to-vigorous PA [MVPA], lifestyle, and light PA organized by occupational category were ranked in ascending order and SB was ranked in descending order. Summing the ranks of the six accelerometer-derived variables generated a summary score for each occupational category, which was re-ranked in ascending order. Higher rankings indicated higher levels of OA, lower rankings indicated lower levels of OA. Tertiles of the summary score were used to establish three mutually exclusive accelerometer-determined OA groupings: high OA, intermediate OA, and low OA. According to their summary score, 'farm and nursery workers' were classified as high OA and 'secretaries, stenographers, and typists' were classified as low OA. Consistent with previous research, some low OA occupational categories (e.g., 'engineers, architects, and scientists', 'technicians and related support occupations', 'management related occupations', 'executives, administrators, and managers', 'protective services', and 'writers, artists, entertainers, and athletes') associated with higher education and income had relatively greater amounts of MVPA compared to other low OA occupational categories, likely due to the greater percentage of men in those occupations and/or the influence of higher levels of leisure time PA. Men had more TAC, activity counts/minute and time in MVPA, but similar proportions of SB compared to women in all three OA groupings. Objectively measured PA allowed for a more precise estimate of the amount of PA and SB associated with different occupations and facilitated systematic classification of the 40 different occupational categories into three distinct OA groupings. This information provides new opportunities to explore the relationship between OA and health outcomes.

High-mobility group box 1 inhibits HCO3− absorption in the medullary thick ascending limb through RAGE-Rho-ROCK-mediated inhibition of basolateral Na+/H+ exchange

PubMed Central

Watts, Bruns A.; George, Thampi; Badalamenti, Andrew

2016-01-01

High-mobility group box 1 (HMGB1) is a nuclear protein released extracellularly in response to infection or injury, where it activates immune responses and contributes to the pathogenesis of kidney dysfunction in sepsis and sterile inflammatory disorders. Recently, we demonstrated that HMGB1 inhibits HCO3− absorption in perfused rat medullary thick ascending limbs (MTAL) through a basolateral receptor for advanced glycation end products (RAGE)-dependent pathway that is additive to Toll-like receptor 4 (TLR4)-ERK-mediated inhibition by LPS (Good DW, George T, Watts BA III. Am J Physiol Renal Physiol 309: F720–F730, 2015). Here, we examined signaling and transport mechanisms that mediate inhibition by HMGB1. Inhibition of HCO3− absorption by HMGB1 was eliminated by the Rho-associated kinase (ROCK) inhibitor Y27632 and by a specific inhibitor of Rho, the major upstream activator of ROCK. HMGB1 increased RhoA and ROCK1 activity. HMGB1-induced ROCK1 activation was eliminated by the RAGE antagonist FPS-ZM1 and by inhibition of Rho. The Rho and ROCK inhibitors had no effect on inhibition of HCO3− absorption by bath LPS. Inhibition of HCO3− absorption by HMGB1 was eliminated by bath amiloride, 0 Na+ bath, and the F-actin stabilizer jasplakinolide, three conditions that selectively prevent inhibition of MTAL HCO3− absorption mediated through NHE1. HMGB1 decreased basolateral Na+/H+ exchange activity through activation of ROCK. We conclude that HMGB1 inhibits HCO3− absorption in the MTAL through a RAGE-RhoA-ROCK1 signaling pathway coupled to inhibition of NHE1. The HMGB1-RAGE-RhoA-ROCK1 pathway thus represents a potential target to attenuate MTAL dysfunction during sepsis and other inflammatory disorders. HMGB1 and LPS inhibit HCO3− absorption through different receptor signaling and transport mechanisms, which enables these pathogenic mediators to act directly and independently to impair MTAL function. PMID:27358052

Acetylcholine-dependent upregulation of TASK-1 channels in thalamic interneurons by a smooth muscle-like signalling pathway.

PubMed

Leist, Michael; Rinné, Susanne; Datunashvili, Maia; Aissaoui, Ania; Pape, Hans-Christian; Decher, Niels; Meuth, Sven G; Budde, Thomas

2017-09-01

The ascending brainstem transmitter acetylcholine depolarizes thalamocortical relay neurons while it induces hyperpolarization in local circuit inhibitory interneurons. Sustained K + currents are modulated in thalamic neurons to control their activity modes; for the interneurons the molecular nature of the underlying ion channels is as yet unknown. Activation of TASK-1 K + channels results in hyperpolarization of interneurons and suppression of their action potential firing. The modulation cascade involves a non-receptor tyrosine kinase, c-Src. The present study identifies a novel pathway for the activation of TASK-1 channels in CNS neurons that resembles cholinergic signalling and TASK-1 current modulation during hypoxia in smooth muscle cells. The dorsal part of the lateral geniculate nucleus (dLGN) is the main thalamic site for state-dependent transmission of visual information. Non-retinal inputs from the ascending arousal system and inhibition provided by γ-aminobutyric acid (GABA)ergic local circuit interneurons (INs) control neuronal activity within the dLGN. In particular, acetylcholine (ACh) depolarizes thalamocortical relay neurons by inhibiting two-pore domain potassium (K 2P ) channels. Conversely, ACh also hyperpolarizes INs via an as-yet-unknown mechanism. By using whole cell patch-clamp recordings in brain slices and appropriate pharmacological tools we here report that stimulation of type 2 muscarinic ACh receptors induces IN hyperpolarization by recruiting the G-protein βγ subunit (Gβγ), class-1A phosphatidylinositol-4,5-bisphosphate 3-kinase, and cellular and sarcoma (c-Src) tyrosine kinase, leading to activation of two-pore domain weakly inwardly rectifying K + channel (TWIK)-related acid-sensitive K + (TASK)-1 channels. The latter was confirmed by the use of TASK-1-deficient mice. Furthermore inhibition of phospholipase Cβ as well as an increase in the intracellular level of phosphatidylinositol-3,4,5-trisphosphate facilitated the muscarinic effect. Our results have uncovered a previously unknown role of c-Src tyrosine kinase in regulating IN function in the brain and identified a novel mechanism by which TASK-1 channels are activated in neurons. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Remote sensing education in NASA's technology transfer program

NASA Technical Reports Server (NTRS)

Weinstein, R. H.

1981-01-01

Remote sensing is a principal focus of NASA's technology transfer program activity with major attention to remote sensing education the Regional Program and the University Applications Program. Relevant activities over the past five years are reviewed and perspective on future directions is presented.

7 CFR 2.72 - Chairman, World Agricultural Outlook Board.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Commodity Estimates Committees prior to any release outside the Department. (4) Related to remote sensing..., developing, and carrying out satellite remote sensing activities to assure full consideration and evaluation... to the Department's remote sensing activities including: (A) Inter- and intra-agency meetings...

Drinking sucrose enhances quinpirole-induced yawning in rats

PubMed Central

Baladi, Michelle G; Newman, Amy H; Thomas, Yvonne M; France, Charles P

2011-01-01

Food and drugs can activate brain dopamine systems and sensitivity to the effects of drugs acting on those systems is influenced by amount and content of food consumed. This study examined the effects of drinking sucrose on behavioral effects of the directly-acting dopamine receptor agonist quinpirole. Male Sprague-Dawley rats (n=6/group) had free access to water or 10% sucrose and quinpirole dose-response curves (yawning and hypothermia) were generated weekly for 8 weeks. Subsequently, all rats drank water for 8 weeks with quinpirole dose-response curves determined on weeks 9, 10, and 16. In rats drinking sucrose, the ascending (D3 receptor-mediated), but not descending (D2 receptor-mediated), limb of the yawning dose-response curve shifted leftward. The D3 receptor-selective antagonist PG01037 shifted the ascending limb of the dose-response curve to the right in all rats. When rats that previously drank sucrose drank water, their sensitivity to quinpirole did not return to normal. Quinpirole-induced hypothermia was not different between groups. These data show that drinking sucrose increases sensitivity to a dopamine D3, but not D2, receptor-mediated effect and that this change is long lasting. Dopamine receptors mediate the effects of many drugs and the actions of those drugs are likely impacted by dietary factors. PMID:21979833

Drinking sucrose enhances quinpirole-induced yawning in rats.

PubMed

Baladi, Michelle G; Newman, Amy H; Thomas, Yvonne M; France, Charles P

2011-12-01

Food and drugs can activate brain dopamine systems and sensitivity to the effects of drugs acting on those systems is influenced by amount and content of food consumed. This study examined the effects of drinking sucrose on behavioral effects of the direct-acting dopamine receptor agonist quinpirole. Male Sprague-Dawley rats (n=6/group) had free access to water or 10% sucrose and quinpirole dose-response curves (yawning and hypothermia) were generated weekly for 8 weeks. Subsequently, all rats drank water for 8 weeks with quinpirole dose-response curves determined on weeks 9, 10, and 16. In rats drinking sucrose, the ascending (D3 receptor-mediated), but not descending (D2 receptor-mediated), limb of the yawning dose-response curve shifted leftward. The D3 receptor-selective antagonist PG01037 shifted the ascending limb of the dose-response curve to the right in all rats. When rats that previously drank sucrose drank water, their sensitivity to quinpirole did not return to normal. Quinpirole-induced hypothermia was not different between groups. These data show that drinking sucrose increases sensitivity to a dopamine D3, but not D2, receptor-mediated effect and that this change is long lasting. Dopamine receptors mediate the effects of many drugs and the actions of those drugs are likely impacted by dietary factors.

Nitric oxide-mediated intersegmental modulation of cycle frequency in the crayfish swimmeret system.

PubMed

Yoshida, Misaki; Nagayama, Toshiki; Newland, Philip

2018-05-21

Crayfish swimmerets are paired appendages located on the ventral side of each abdominal segment that show rhythmic beating during forward swimming produced by central pattern generators in most abdominal segments. For animals with multiple body segments and limbs, intersegmental coordination of central pattern generators in each segment is crucial for the production of effective movements. Here we develop a novel pharmacological approach to analyse intersegmental modulation of swimmeret rhythm by selectively elevating nitric oxide levels and reducing them with pharmacological agents, in specific ganglia. Bath application of L-arginine, the substrate NO synthesis, increased the cyclical spike responses of the power-stroke motor neurons. By contrast the NOS inhibitor, L-NAME decreased them. To determine the role of the different local centres in producing and controlling the swimmeret rhythm, these two drugs were applied locally to two separate ganglia following bath application of carbachol. Results revealed that there was both ascending and descending intersegmental modulation of cycle frequency of the swimmeret rhythm in the abdominal ganglia and that synchrony of cyclical activity between segments of segments was maintained. We also found that there were gradients in the strength effectiveness in modulation, that ascending modulation of the swimmeret rhythm was stronger than descending modulation. © 2018. Published by The Company of Biologists Ltd.

Neuroanatomic connectivity of the human ascending arousal system critical to consciousness and its disorders.

PubMed

Edlow, Brian L; Takahashi, Emi; Wu, Ona; Benner, Thomas; Dai, Guangping; Bu, Lihong; Grant, Patricia Ellen; Greer, David M; Greenberg, Steven M; Kinney, Hannah C; Folkerth, Rebecca D

2012-06-01

The ascending reticular activating system (ARAS) mediates arousal, an essential component of human consciousness. Lesions of the ARAS cause coma, the most severe disorder of consciousness. Because of current methodological limitations, including of postmortem tissue analysis, the neuroanatomic connectivity of the human ARAS is poorly understood. We applied the advanced imaging technique of high angular resolution diffusion imaging (HARDI) to elucidate the structural connectivity of the ARAS in 3 adult human brains, 2 of which were imaged postmortem. High angular resolution diffusion imaging tractography identified the ARAS connectivity previously described in animals and also revealed novel human pathways connecting the brainstem to the thalamus, the hypothalamus, and the basal forebrain. Each pathway contained different distributions of fiber tracts from known neurotransmitter-specific ARAS nuclei in the brainstem. The histologically guided tractography findings reported here provide initial evidence for human-specific pathways of the ARAS. The unique composition of neurotransmitter-specific fiber tracts within each ARAS pathway suggests structural specializations that subserve the different functional characteristics of human arousal. This ARAS connectivity analysis provides proof of principle that HARDI tractography may affect the study of human consciousness and its disorders, including in neuropathologic studies of patients dying in coma and the persistent vegetative state.

Supravalvular aortic stenosis after arterial switch operation.

PubMed

Maeda, Takuya; Koide, Masaaki; Kunii, Yoshifumi; Watanabe, Kazumasa; Kanzaki, Tomohito; Ohashi, Yuko

2016-07-01

Supravalvular aortic stenosis as a late complication of transposition of the great arteries is very rare, and only a few cases have been reported. We describe the case of a 14-year-old girl who developed supravalvular aortic stenosis as a late complication of the arterial switch operation for transposition of the great arteries. The narrowed ascending aorta was replaced with a graft. The right pulmonary artery was transected to approach the ascending aorta which adhered severely to the main pulmonary trunk, and we obtained a good operative field. © The Author(s) 2015.

Incidence and diagnosis of deep vein thrombosis associated with pregnancy.

PubMed

Kierkegaard, A

1983-01-01

The incidence of deep vein thrombosis (DVT), diagnosed by ascending phlebography, has been calculated retrospectively in a group of 14 869 obstetrical patients. The incidence was calculated to 0.13 per thousand antepartum and 0.61 per thousand postpartum. The study revealed that clinical signs and symptoms of thrombosis are very unreliable in pregnant women but more reliable in puerperal women. It is concluded that objective diagnosis of thrombosis is important in pregnant women, and ascending phlebography is a rewarding objective method to use in pregnant women.

Tsugaru Iwaki Skyline, Japan

NASA Image and Video Library

2018-05-03

The Tsugaru Iwaki Skyline is a toll road in northern Japan, which partially ascends Mount Iwaki stratovolcano, and is notable for its steep gradient and 69 hairpin turns. The road ascends 806 meters over an average gradient of 8.66%, with some sections going up to 10%. The Tsugaru Iwaki Skyline has been considered one of the most dangerous mountain roads in the world. (Wikipedia) The image was acquired May 26, 2015, and is located at 40.6 degrees north, 140.3 degrees east. https://photojournal.jpl.nasa.gov/catalog/PIA22385

Recovery of Hypersomnia Concurrent With Recovery of an Injured Ascending Reticular Activating System in a Stroke Patient

PubMed Central

Jang, Sung Ho; Lee, Han Do; Chang, Chul Hoon; Jung, Young Jin

2016-01-01

Abstract We report on a stroke patient who showed recovery of hypersomnia concurrent with the recovery of an injured ascending reticular activating system (ARAS), which was demonstrated by diffusion tensor tractography (DTT). A 70-year-old female patient underwent coiling of the left ruptured posterior communicating artery after subarachnoid hemorrhage and both extraventricular drainage for management of an intraventricular hemorrhage. At 2 months after onset, when she started rehabilitation, she exhibited intact consciousness, with the full score on the Glasgow Coma Scale: 15. However, she showed severe hypersomnia: she always fell asleep without external stimulation and the Epworth Sleepiness Scale (EPS) score was 24 (full score: 24, cut off for hypersomnia: 10). She underwent comprehensive rehabilitative therapy, including neurotropic drugs, physical therapy, and occupational therapy. Her hypersomnia has shown improvement as 14 (3 months after onset), 11 (4 months after onset), 7 (12 months after onset), and 6 (24 months after onset), respectively. On 2-month DTT, narrowing of both lower dorsal and ventral ARASs was observed on both sides: in particular, among 4 neural tracts of the lower ARAS, the right lower ventral ARAS was the narrowest. By contrast, on 24-month DTT, the 4 narrowed neural tracts of both lower dorsal and ventral ARASs were thickened compared with those of 2-month DTT. Recovery of hypersomnia with recovery of an injured lower ARAS on DTT was observed in a stroke patient. Our results suggest that evaluation of the lower ARAS using DTT might be useful for stroke patients with hypersomnia. PMID:26765455

Spinal and pontine relay pathways mediating respiratory rhythm entrainment by limb proprioceptive inputs in the neonatal rat.

PubMed

Giraudin, Aurore; Le Bon-Jégo, Morgane; Cabirol, Marie-Jeanne; Simmers, John; Morin, Didier

2012-08-22

The coordination of locomotion and respiration is widespread among mammals, although the underlying neural mechanisms are still only partially understood. It was previously found in neonatal rat that cyclic electrical stimulation of spinal cervical and lumbar dorsal roots (DRs) can fully entrain (1:1 coupling) spontaneous respiratory activity expressed by the isolated brainstem/spinal cord. Here, we used a variety of preparations to determine the type of spinal sensory inputs responsible for this respiratory rhythm entrainment, and to establish the extent to which limb movement-activated feedback influences the medullary respiratory networks via direct or relayed ascending pathways. During in vivo overground locomotion, respiratory rhythm slowed and became coupled 1:1 with locomotion. In hindlimb-attached semi-isolated preparations, passive flexion-extension movements applied to a single hindlimb led to entrainment of fictive respiratory rhythmicity recorded in phrenic motoneurons, indicating that the recruitment of limb proprioceptive afferents could participate in the locomotor-respiratory coupling. Furthermore, in correspondence with the regionalization of spinal locomotor rhythm-generating circuitry, the stimulation of DRs at different segmental levels in isolated preparations revealed that cervical and lumbosacral proprioceptive inputs are more effective in this entraining influence than thoracic afferent pathways. Finally, blocking spinal synaptic transmission and using a combination of electrophysiology, calcium imaging and specific brainstem lesioning indicated that the ascending entraining signals from the cervical or lumbar limb afferents are transmitted across first-order synapses, probably monosynaptic, in the spinal cord. They are then conveyed to the brainstem respiratory centers via a brainstem pontine relay located in the parabrachial/Kölliker-Fuse nuclear complex.

Distribution of activity at the solar active longitudes between 1979 - 2011 in the northern hemisphere

NASA Astrophysics Data System (ADS)

Gyenge, N.; Baranyi, T.; Ludmány, A.

The solar active longitudes were studied in the northern hemisphere in cycles 22 and 23 by using data of DPD sunspot catalogue. The active longitudes are not fixed in the Carrington system, they have a well recognizable migration path between the descending phase of cycle 21 (from about 1984) and ascending phase of cycle 23 (until about 1996), out of this interval the migration path is ambiguous. The longitudinal distribution on both sides of the path has been computed and averaged for the length of the path. The so-called flip-flop phenomenon, when the activity temporarily gets to the opposite longitude, can also be recognized. The widths of the active domains are fairly narrow in the increasing and decaying phases of cycle 22, their half widths are about 20°-30° for both the main and secondary active belts but it is more flat and stretched around the maximum with a half width of about 60°.

Indicators of international remote sensing activities

NASA Technical Reports Server (NTRS)

Spann, G. W.

1977-01-01

The extent of worldwide remote sensing activities, including the use of satellite and high/medium altitude aircraft data was studied. Data were obtained from numerous individuals and organizations with international remote sensing responsibilities. Indicators were selected to evaluate the nature and scope of remote sensing activities in each country. These indicators ranged from attendance at remote sensing workshops and training courses to the establishment of earth resources satellite ground stations and plans for the launch of earth resources satellites. Results indicate that this technology constitutes a rapidly increasing component of environmental, land use, and natural resources investigations in many countries, and most of these countries rely on the LANDSAT satellites for a major portion of their data.

Darcy-Forchheimer flow of Maxwell nanofluid flow with nonlinear thermal radiation and activation energy

NASA Astrophysics Data System (ADS)

Sajid, T.; Sagheer, M.; Hussain, S.; Bilal, M.

2018-03-01

The present article is about the study of Darcy-Forchheimer flow of Maxwell nanofluid over a linear stretching surface. Effects like variable thermal conductivity, activation energy, nonlinear thermal radiation is also incorporated for the analysis of heat and mass transfer. The governing nonlinear partial differential equations (PDEs) with convective boundary conditions are first converted into the nonlinear ordinary differential equations (ODEs) with the help of similarity transformation, and then the resulting nonlinear ODEs are solved with the help of shooting method and MATLAB built-in bvp4c solver. The impact of different physical parameters like Brownian motion, thermophoresis parameter, Reynolds number, magnetic parameter, nonlinear radiative heat flux, Prandtl number, Lewis number, reaction rate constant, activation energy and Biot number on Nusselt number, velocity, temperature and concentration profile has been discussed. It is viewed that both thermophoresis parameter and activation energy parameter has ascending effect on the concentration profile.

A visual pathway links brain structures active during magnetic compass orientation in migratory birds.

PubMed

Heyers, Dominik; Manns, Martina; Luksch, Harald; Güntürkün, Onur; Mouritsen, Henrik

2007-09-26

The magnetic compass of migratory birds has been suggested to be light-dependent. Retinal cryptochrome-expressing neurons and a forebrain region, "Cluster N", show high neuronal activity when night-migratory songbirds perform magnetic compass orientation. By combining neuronal tracing with behavioral experiments leading to sensory-driven gene expression of the neuronal activity marker ZENK during magnetic compass orientation, we demonstrate a functional neuronal connection between the retinal neurons and Cluster N via the visual thalamus. Thus, the two areas of the central nervous system being most active during magnetic compass orientation are part of an ascending visual processing stream, the thalamofugal pathway. Furthermore, Cluster N seems to be a specialized part of the visual wulst. These findings strongly support the hypothesis that migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds "see" the reference compass direction provided by the geomagnetic field.

Specialized sugar sensing in diverse fungi.

PubMed

Brown, Victoria; Sabina, Jeffrey; Johnston, Mark

2009-03-10

S. cerevisiae senses glucose and galactose differently. Glucose is detected through sensors that reside in the cellular plasma membrane. When activated, the sensors initiate a signal-transduction cascade that ultimately inactivates the Rgt1 transcriptional repressor by causing degradation of its corepressors Mth1 and Std1. This results in the expression of many HXT genes encoding glucose transporters. The ensuing flood of glucose into the cell activates Mig1, a transcriptional repressor that mediates "glucose repression" of many genes, including the GAL genes; hence, glucose sensing hinders galactose utilization. Galactose is sensed in the cytoplasm via Gal3. Upon binding galactose (and ATP), Gal3 sequesters the Gal80 protein, thereby emancipating the Gal4 transcriptional activator of the GAL genes. Gal4 also activates expression of MTH1, encoding a corepressor critical for Rgt1 function. Thus, galactose inhibits glucose assimilation by encouraging repression of HXT genes. C. albicans senses glucose similarly to S. cerevisiae but does not sense galactose through Gal3-Gal80-Gal4. Its genome harbors no GAL80 ortholog, and the severely truncated CaGal4 does not regulate CaGAL genes. We present evidence that C. albicans senses galactose with its Hgt4 glucose sensor, a capability that is enabled by transcriptional "rewiring" of its sugar-sensing signal-transduction pathways. We suggest that galactose sensing through Hgt4 is ancestral in fungi.

The effects of wine-processing on ascending and descending: The distribution of flavonoids in rat tissues after oral administration of crude and wine-processed Radix scutellariae.

PubMed

Huang, Ping; Tan, Shanzhong; Zhang, Yong-xin; Li, Jun-song; Chai, Chuan; Li, Jin-ji; Cai, Bao-chang

2014-08-08

Ascending and descending theory is a core principle of traditional Chinese medicine (TCM) theories. It plays an essential role in TCM clinical applications. Some TCM medicine has specific properties, which could alter the inclination and direction of their actions. The properties of the ascending and floating process of one herbal medicine are affected by means of herb processing. Wine-processing, which is sautéing with rice wine, is one of the most popular technologies of herb processing. Wine-processing increases the inclination and direction of its actions, thereby producing or strengthening their efficacy in cleaning the upper-energizer heat. Radix scutellariae, the dried roots of Scutellaria baicalensis Georgi, is a well-known TCM used for the treatment of inflammation, pyrexia, jaundice, etc. Recently, wine-processed Radix scutellariae was normally applied in clinical studies for the treatment of upper-energizer syndrome. In order to investigate the effects of wine-processing on ascending and descending of Radix scutellariae, the comparative study of distribution of flavonoids in rat tissues of triple energizers (SanJiao-upper, middle, lower jiao) after oral administration of crude and wine-processed Radix scutellariae aqueous extracts was carried out. The rats were randomly assigned to two groups and orally administered with crude and wine-processed Radix scutellariae aqueous extracts, respectively. At different pre-determined time points after administration, the concentrations of compounds in rat tissue homogenate were determined, and the main tissue pharmacokinetic parameters were investigated. Tissue pharmacokinetic parameters including AUC0-t, t1/2, Tmax and Cmax were calculated using DAS 2.0. An unpaired Student t-test was used to compare the differences in tissue pharmacokinetic parameters between the two groups. All the results were expressed as arithmetic mean±S.D. The parameters of Cmax and AUC0-t of some flavonoids in wine-processed Radix scutellariae were remarkably increased (p<0.05, p<0.01, p<0.001) in the rat upper-energizer tissues (lung and heart) compared with those of the crude group. However, in the rat middle- and lower-energizer tissues (spleen, liver and kidney), the Cmax and AUC0-t of some flavonoids were significantly decreased (p<0.05, p<0.01) compared with the crude group. The main explanation for these differences seems to the effects of wine-processing on ascending and descending theory. All of these differences in the distribution of triple energizers after oral administration of crude and wine-processed Radix scutellariae aqueous extracts may lead to the increase of efficacy on the upper-energizer tissues and were in compliance with the ascending and descending theory. Therefore, wine-processing was recommended when Radix scutellariae was used for cleaning the upper-energizer heat and humidity. The obtained knowledge can be used to evaluate the impact of these differences on the efficacy of both the drugs in clinical applications and might be helpful in explaining the effects of wine-processing on ascending and descending theory. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Sexual Differentiation of Motivation: a novel mechanism?

PubMed Central

Becker, Jill B.

2009-01-01

Sex differences in motivation are apparent for the motivation to engage in sexual behavior, the motivation to take drugs of abuse, and the motivation to engage in parental behavior. In both males and females there is an increase in NAcc DA associated with motivated behaviors. Here it proposed that sex differences in the regulation of DA activity in the ascending mesolimbic projections may underlie sex differences in motivation. In particular, sex differences in the neuroendocrine regulation of this brain system plays a role in the expression of sex differences in motivated behaviors. Here it is proposed that sexual differentiation of motivation is mediated, at least in part, by a novel mechanism in which ovarian hormones secreted at puberty in the female actively feminize the DA system. PMID:19446081

Active microwave remote sensing of oceans, chapter 3

NASA Technical Reports Server (NTRS)

1975-01-01

A rationale is developed for the use of active microwave sensing in future aerospace applications programs for the remote sensing of the world's oceans, lakes, and polar regions. Summaries pertaining to applications, local phenomena, and large-scale phenomena are given along with a discussion of orbital errors.

Anatomy of the Le Fort I segment: Are arterial variations a potential risk factor for avascular bone necrosis in Le Fort I osteotomies?

PubMed

Bruneder, Simon; Wallner, Jürgen; Weiglein, Andreas; Kmečová, Ĺudmila; Egger, Jan; Pilsl, Ulrike; Zemann, Wolfgang

2018-05-02

Osteotomies of the Le Fort I segment are routine operations with low complication rates. Ischemic complications are rare, but can have severe consequences that may lead to avascular bone necrosis of the Le Fort I segment. Therefore the aim of this study was to investigate the blood supply and special arterial variants of the Le Fort I segment responsible for arterial hypoperfusion or ischemic avascular necrosis after surgery. The arterial anatomy of the Le Fort I segment's blood supply using 30 halved human cadaver head specimens was analyzed after complete dissection until the submicroscopic level. In all specimens the arterial variants of the Le Fort I segment and also the arterial diameters measured at two points were evaluated. The typical known vascularization pattern was apparent in 90% of all specimens, in which the ascending palatine (D1: 1,2 mm ± 0,34 mm; D2: 0,8 mm ± 0,34 mm) and ascending pharyngeal artery (D1: 1,3 mm ± 0,58 mm; D2: <0,4 mm) were both supplying the Le Fort I segment. However in 10% of all specimens, the Le Fort I segment was dependent on the ascending pharyngeal artery alone and the missing ascending palatine artery was replaced with the anterior branch of the ascending pharyngeal artery (D1: 1,9 mm ± 0,32; D2: 1,0 mm ± 0,3 mm). This study is the first description of a special type of arterial variation of the Le Fort I segment. The type of this arterial variation, its clinical relevance and potential consequences are explained. Individuals with this special arterial anatomy may clinically be at a high risk for hypoperfusion and avascular segment necrosis after surgery. An individualized operation plan may prevent ischemic complications in at-risk patients. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Obtaining the biomechanical behavior of ascending aortic aneurysm via the use of novel speckle tracking echocardiography.

PubMed

Alreshidan, Mohammed; Shahmansouri, Nastaran; Chung, Jennifer; Lash, Vynka; Emmott, Alexander; Leask, Richard L; Lachapelle, Kevin

2017-04-01

Ex vivo measurement of ascending aortic biomechanical properties may help understand the risk for rupture or dissection of dilated ascending aortas. A validated in vivo method that can predict aortic biomechanics does not exist. Speckle tracking transesophageal echocardiography (TEE) has been used to measure ventricular stiffness; we sought to determine whether speckle TEE could be adapted to estimate aortic stiffness in vivo and compare these findings with those obtained by ex vivo tissue measurements. A total of 17 patients undergoing ascending aortic resection were recruited to with a mean aortic diameter was 56.16 ± 15 mm. Intraoperative speckle TEE tracking analysis was used to calculate aortic stiffness index using the following equation: β2=ln(SBP/DBP)/AoS, where β2 is the stiffness index; SBP is systolic blood pressure; DBP is diastolic blood pressure; and AoS is the circumferential strain. Ex vivo stiffness was obtained by mechanical tissue testing according to previously described methods. The aortic ring at the pulmonary trunk was divided into 4 equal quadrants. The in vivo stiffness index for the inner curvature, anterior wall, outer curvature, and posterior wall were 0.0544 ± 0.0490, 0.0295 ± 0.0199, 0.0411 ± 0.0328, and 0.0502 ± 0.0320, respectively. The mean ex vivo 25% apparent stiffness for inner curvature, anterior wall, outer curvature, and posterior wall were 0.0616 ± 0.0758 MPa, 0.0352 ± 0.00992 MPa, 0.0405 ± 0.0199 MPa, and 0.0327 ± 0.0106 MPa, respectively. The patient-matched ex vivo 25% apparent stiffness and in vivo stiffness index were not significantly different (P = .8617, 2-way analysis of variance with repeated measures). The use of speckle TEE appears to be a promising technique to estimate ex vivo mechanical properties of the ascending aortic tissue. Copyright © 2016 The American Association for Thoracic Surgery. All rights reserved.

Regional and directional compliance of the healthy aorta: an ex vivo study in a porcine model.

PubMed

Krüger, Tobias; Veseli, Kujtim; Lausberg, Henning; Vöhringer, Luise; Schneider, Wilke; Schlensak, Christian

2016-07-01

To gain differential knowledge about the physiological compliance and wall strength of the different regions of the aorta, including the ascending aorta, arch and descending aorta in both the circumferential and longitudinal directions, and to generate a hypothesis on the pathophysiological mechanisms that lead to Type A aortic dissection. Fresh tissue specimens from 22 ex vivo porcine aortas were analysed on a tensile tester. Regional and directional compliance, failure stress and failure strain were recorded. Aortic compliance appeared as a linear function of the natural logarithm (ln) of wall stress. Compliance significantly decreased along the length of the aorta. In the ascending aorta, longitudinal compliance significantly (P = 0.003) exceeded circumferential compliance, and the outer curvature was more compliant than the inner curvature (P = 0.03). In the descending aorta, this relationship is reversed: the circumferential compliance exceeded the longitudinal compliance, and the outer aspect was more compliant (P = 0.003). The median circumferential failure stress of all aortic segments was in the range of 2000-2750 kPa, whereas the longitudinal failure stress in the ascending aorta and the arch had values of 750-1000 kPa, which were significantly lower (P < 0.05). Surprisingly, the longitudinal failure stress of the inner aspect of the descending aorta was extraordinarily high (2000 kPa). Failure strain, similar to compliance, was highest in the ascending aorta and decreased along the aorta. The aorta appears to be a complex organ with distinct regional and directional differences in compliance and wall strength that is designed to effectively absorb the kinetic energy of cardiac systole and to cushion the momentum of systolic impact. Under normotensive conditions and a preconditioned physiological morphology, the aortic wall works in the steep part of the logarithmic strain-stress function; under hypertensive conditions and pathological morphology, the wall reacts in an non-compliant manner. The high longitudinal compliance and low failure stress of the ascending aorta and subsequent pathological changes may be the main determinants of the recurrent patho-anatomy of Type A aortic dissection. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Regional and directional compliance of the healthy aorta: an ex vivo study in a porcine model†

PubMed Central

Krüger, Tobias; Veseli, Kujtim; Lausberg, Henning; Vöhringer, Luise; Schneider, Wilke; Schlensak, Christian

2016-01-01

OBJECTIVES To gain differential knowledge about the physiological compliance and wall strength of the different regions of the aorta, including the ascending aorta, arch and descending aorta in both the circumferential and longitudinal directions, and to generate a hypothesis on the pathophysiological mechanisms that lead to Type A aortic dissection. METHODS Fresh tissue specimens from 22 ex vivo porcine aortas were analysed on a tensile tester. Regional and directional compliance, failure stress and failure strain were recorded. RESULTS Aortic compliance appeared as a linear function of the natural logarithm (ln) of wall stress. Compliance significantly decreased along the length of the aorta. In the ascending aorta, longitudinal compliance significantly (P = 0.003) exceeded circumferential compliance, and the outer curvature was more compliant than the inner curvature (P = 0.03). In the descending aorta, this relationship is reversed: the circumferential compliance exceeded the longitudinal compliance, and the outer aspect was more compliant (P = 0.003). The median circumferential failure stress of all aortic segments was in the range of 2000–2750 kPa, whereas the longitudinal failure stress in the ascending aorta and the arch had values of 750–1000 kPa, which were significantly lower (P < 0.05). Surprisingly, the longitudinal failure stress of the inner aspect of the descending aorta was extraordinarily high (2000 kPa). Failure strain, similar to compliance, was highest in the ascending aorta and decreased along the aorta. CONCLUSION The aorta appears to be a complex organ with distinct regional and directional differences in compliance and wall strength that is designed to effectively absorb the kinetic energy of cardiac systole and to cushion the momentum of systolic impact. Under normotensive conditions and a preconditioned physiological morphology, the aortic wall works in the steep part of the logarithmic strain–stress function; under hypertensive conditions and pathological morphology, the wall reacts in an non-compliant manner. The high longitudinal compliance and low failure stress of the ascending aorta and subsequent pathological changes may be the main determinants of the recurrent patho-anatomy of Type A aortic dissection. PMID:26993474

Endovascular stent grafting for ascending aorta diseases.

PubMed

Baikoussis, Nikolaos G; Antonopoulos, Constantine N; Papakonstantinou, Nikolaos A; Argiriou, Mihalis; Geroulakos, George

2017-11-01

Conventional open surgery encompassing cardiopulmonary bypass has been traditionally used for the treatment of ascending aorta diseases. However, more than one in five of these patients will be finally considered unfit for open repair. We conducted a systematic review and meta-analysis to investigate the role of thoracic endovascular aortic repair (TEVAR) for aortic diseases limited to the ascending aorta. The current meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We investigated patients' baseline characteristics along with early (30 days/in-hospital stay) and late (beyond 30 days/in-hospital stay) outcomes after TEVAR limited to the ascending aorta and not involving the arch vessels. Separate analyses for case reports and case series were conducted, and pooled proportions with 95% confidence intervals (CIs) of outcome rates were calculated. Approximately 67% of the patients had a prior cardiac operation. TEVAR was performed mainly for acute or chronic Stanford type A dissection (49%) or pseudoaneurysm (28%). The device was usually delivered through the femoral artery (67%), and rapid ventricular pacing was used in nearly half of the patients. Technical success of the method was 95.5% (95% CI, 87.8-99.8). Among the early outcomes, conversion to open repair was 0.7% (95% CI, 0.1-4.8), whereas mortality was 2.9% (95% CI, 0.02-8.6). We estimated a pooled rate of 1.8% (95% CI, 0.1-7.0) for neurologic events (stroke or transient ischemic attack) and 0.8% (95% CI, 0.1-5.6) for myocardial infarction. Late endoleak was recorded in 16.4% (95% CI, 8.2-26.0), and 4.4% (95% CI, 0.1-12.4) of the population died in the postoperative period. Finally, reoperation was recorded in 8.9% (95% CI, 3.1-16.4) of the study sample. TEVAR in the ascending aorta seems to be safe and feasible for selected patients with various aortic diseases, although larger studies are required. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Emergence of Spatial Stream Segregation in the Ascending Auditory Pathway.

PubMed

Yao, Justin D; Bremen, Peter; Middlebrooks, John C

2015-12-09

Stream segregation enables a listener to disentangle multiple competing sequences of sounds. A recent study from our laboratory demonstrated that cortical neurons in anesthetized cats exhibit spatial stream segregation (SSS) by synchronizing preferentially to one of two sequences of noise bursts that alternate between two source locations. Here, we examine the emergence of SSS along the ascending auditory pathway. Extracellular recordings were made in anesthetized rats from the inferior colliculus (IC), the nucleus of the brachium of the IC (BIN), the medial geniculate body (MGB), and the primary auditory cortex (A1). Stimuli consisted of interleaved sequences of broadband noise bursts that alternated between two source locations. At stimulus presentation rates of 5 and 10 bursts per second, at which human listeners report robust SSS, neural SSS is weak in the central nucleus of the IC (ICC), it appears in the nucleus of the brachium of the IC (BIN) and in approximately two-thirds of neurons in the ventral MGB (MGBv), and is prominent throughout A1. The enhancement of SSS at the cortical level reflects both increased spatial sensitivity and increased forward suppression. We demonstrate that forward suppression in A1 does not result from synaptic inhibition at the cortical level. Instead, forward suppression might reflect synaptic depression in the thalamocortical projection. Together, our findings indicate that auditory streams are increasingly segregated along the ascending auditory pathway as distinct mutually synchronized neural populations. Listeners are capable of disentangling multiple competing sequences of sounds that originate from distinct sources. This stream segregation is aided by differences in spatial location between the sources. A possible substrate of spatial stream segregation (SSS) has been described in the auditory cortex, but the mechanisms leading to those cortical responses are unknown. Here, we investigated SSS in three levels of the ascending auditory pathway with extracellular unit recordings in anesthetized rats. We found that neural SSS emerges within the ascending auditory pathway as a consequence of sharpening of spatial sensitivity and increasing forward suppression. Our results highlight brainstem mechanisms that culminate in SSS at the level of the auditory cortex. Copyright © 2015 Yao et al.

Extracellular acidification activates ovarian cancer G-protein-coupled receptor 1 and GPR4 homologs of zebra fish

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

Mochimaru, Yuta; Azuma, Morio; Oshima, Natsuki

2015-02-20

Mammalian ovarian G-protein-coupled receptor 1 (OGR1) and GPR4 are identified as a proton-sensing G-protein-coupled receptor coupling to multiple intracellular signaling pathways. In the present study, we examined whether zebra fish OGR1 and GPR4 homologs (zOGR1 and zGPR4) could sense protons and activate the multiple intracellular signaling pathways and, if so, whether the similar positions of histidine residue, which is critical for sensing protons in mammalian OGR and GPR4, also play a role to sense protons and activate the multiple signaling pathways in the zebra fish receptors. We found that extracellular acidic pH stimulated CRE-, SRE-, and NFAT-promoter activities in zOGR1more » overexpressed cells and stimulated CRE- and SRE- but not NFAT-promoter activities in zGPR4 overexpressed cells. The substitution of histidine residues at the 12th, 15th, 162th, and 264th positions from the N-terminal of zOGR1 with phenylalanine attenuated the proton-induced SRE-promoter activities. The mutation of the histidine residue at the 78th but not the 84th position from the N-terminal of zGPR4 to phenylalanine attenuated the proton-induced SRE-promoter activities. These results suggest that zOGR1 and zGPR4 are also proton-sensing G-protein-coupled receptors, and the receptor activation mechanisms may be similar to those of the mammalian receptors. - Highlights: • Zebra fish OGR1 and GPR4 homologs (zOGR1, zGPR4) are proton-sensing receptors. • The signaling pathways activated by zOGR1 and zGPR4 are different. • Histidine residues critical for sensing protons are conserved.« less

A viscous-to-brittle transition in eruptions through clay suspensions

NASA Astrophysics Data System (ADS)

Schmid, Diana; Scheu, Bettina; Wadsworth, Fabian B.; Kennedy, Ben M.; Jolly, Arthur; Dingwell, Donald B.

2017-05-01

Volcanic lakes are often associated with active geothermal circulation, mineral alteration, and precipitation, each of which can complicate the analysis of shallow magma physics, geophysical signals, and chemical signals. The rheology of the lake and associated hydrothermal system affects the eruptive activity as bubbles ascend and burst through the lake producing distinct ejection behavior. We investigate such phenomena by conducting scaled experiments in which heated water-clay suspensions are decompressed rapidly from relevant pressures. After a jet phase of expanding vapor, the suspensions break up into ejecta that are either angular or droplet geometry. We parameterize these regimes and find a universal clay volume fraction of 0.28 below which the ejecta are form droplets and above which the ejecta are angular. We propose a regime diagram for optical observations of active lakes, which allows rheological characterization and informs volcanic monitoring.

Patient-related factors influencing detectability of coronary arteries in 320-row CT angiography in infants with complex congenital heart disease.

PubMed

Yamasaki, Yuzo; Kawanami, Satoshi; Kamitani, Takeshi; Sagiyama, Koji; Shin, Seitaro; Hino, Takuya; Nagata, Hazumu; Yabuuchi, Hidetake; Nagao, Michinobu; Honda, Hiroshi

2018-05-05

To investigate the performance of second-generation 320-row computed tomographic (CT) angiography (CTA) in detecting coronary arteries and identify factors influencing visibility of the coronary arteries in infants with complex congenital heart disease (CHD). Data of 60 infants (aged 0-2 years, median 2 months) with complex CHD who underwent examination using 320-row CTA with low-dose prospective electrocardiogram-triggered volume target scanning were reviewed. The coronary arteries of each infant were assessed using a 0-4-point scoring system based on the number of coronary segments with a visible course. Clinical parameters, the CT value in the ascending aorta, image noise, and the radiation dose were subjected to univariate and multivariate analyses. The mean coronary score for all examinations was 2.6 ± 1.5 points. The mean attenuation in the ascending aorta was 306.7 ± 66.2 HU and the mean standard deviation was 21.7 ± 4.4. The mean effective radiation dose was 1.27 ± 0.39 mSv. Multivariate regression analysis showed significant correlations between coronary score and body weight (p < 0.05) and between coronary score and the CT value in the ascending aorta (p < 0.02). Second-generation 320-row CTA with prospective electrocardiogram-triggered volume target scanning and hybrid iterative reconstruction allows good visibility of the coronary arteries in infants with complex CHD. Body weight and the CT value in the ascending aorta are important factors influencing the visibility of the coronary arteries in infants.

Selection of Reference Genes for Quantitative Real Time PCR (qPCR) Assays in Tissue from Human Ascending Aorta

PubMed Central

Rueda-Martínez, Carmen; Lamas, Oscar; Mataró, María José; Robledo-Carmona, Juan; Sánchez-Espín, Gemma; Jiménez-Navarro, Manuel; Such-Martínez, Miguel; Fernández, Borja

2014-01-01

Dilatation of the ascending aorta (AAD) is a prevalent aortopathy that occurs frequently associated with bicuspid aortic valve (BAV), the most common human congenital cardiac malformation. The molecular mechanisms leading to AAD associated with BAV are still poorly understood. The search for differentially expressed genes in diseased tissue by quantitative real-time PCR (qPCR) is an invaluable tool to fill this gap. However, studies dedicated to identify reference genes necessary for normalization of mRNA expression in aortic tissue are scarce. In this report, we evaluate the qPCR expression of six candidate reference genes in tissue from the ascending aorta of 52 patients with a variety of clinical and demographic characteristics, normal and dilated aortas, and different morphologies of the aortic valve (normal aorta and normal valve n = 30; dilated aorta and normal valve n = 10; normal aorta and BAV n = 4; dilated aorta and BAV n = 8). The expression stability of the candidate reference genes was determined with three statistical algorithms, GeNorm, NormFinder and Bestkeeper. The expression analyses showed that the most stable genes for the three algorithms employed were CDKN1β, POLR2A and CASC3, independently of the structure of the aorta and the valve morphology. In conclusion, we propose the use of these three genes as reference genes for mRNA expression analysis in human ascending aorta. However, we suggest searching for specific reference genes when conducting qPCR experiments with new cohort of samples. PMID:24841551

Intra- and inter-reader reproducibility of blood flow measurements on the ascending aorta and pulmonary artery using cardiac magnetic resonance.

PubMed

Di Leo, Giovanni; D'Angelo, Ida Daniela; Alì, Marco; Cannaò, Paola Maria; Mauri, Giovanni; Secchi, Francesco; Sardanelli, Francesco

2017-03-01

The aim of our study was to estimate the intra- and inter-reader reproducibility of blood flow measurements in the ascending aorta and main pulmonary artery using cardiac magnetic resonance (CMR) and a semi-automated segmentation method. The ethics committee approved this retrospective study. A total of 50 consecutive patients (35 males and 15 females; mean age±standard deviation 27±13 years) affected by congenital heart disease were reviewed. They underwent CMR for flow analysis of the ascending aorta and main pulmonary artery (1.5 T, through-plane phase-contrast sequences). Two independent readers (R1, trained radiology resident; R2, lower-trained technician student) obtained segmented images twice (>10-day interval), using a semi-automated method of segmentation. Peak velocity, forward and backward flows were obtained. Bland-Altman analysis was used and reproducibility was reported as complement to 100% of the ratio between the coefficient of repeatability and the mean. R1 intra-reader reproducibility for the aorta was 99% (peak velocity), 95% (forward flow) and 49% (backward flow); for the pulmonary artery, 99%, 91% and 90%, respectively. R2 intra-reader reproducibility was 92%, 91% and 38%; 98%, 86% and 87%, respectively. Inter-reader reproducibility for the aorta was 91%, 85% and 20%; for the pulmonary artery 96%, 75%, and 82%, respectively. Our results showed a good to excellent reproducibility of blood flow measurements of CMR together with a semiautomated method of segmentation, for all variables except the backward flow of the ascending aorta, with a limited impact of operator's training.

Bicuspid aortic valves are associated with increased wall and turbulence shear stress levels compared to trileaflet aortic valves.

PubMed

Saikrishnan, Neelakantan; Mirabella, Lucia; Yoganathan, Ajit P

2015-06-01

Congenital bicuspid aortic valves (BAVs) are associated with accelerated disease progression, such as leaflet calcification and ascending aorta dilatation. Although common underlying genetic factors have been implicated in accelerated disease in BAV patients, several studies have suggested that altered hemodynamics also play a role in this disease process. The present study compares turbulence and wall shear stress (WSS) measurements between various BAV and trileaflet aortic valve (TAV) models to provide information for mechanobiological models of BAV disease. BAV and TAV models were constructed from excised porcine aortic valves to simulate parametric variations in BAV stenosis, hemodynamics and geometry. Particle image velocimetry experiments were conducted at physiological pressure conditions to characterize velocity fields in the ascending aorta. The velocity fields were post-processed to calculate turbulence, viscous and wall shear stresses in the ascending aorta. Stenosed BAV models showed the presence of eccentric systolic jets, causing increased WSS. Lower cardiac output resulted in a narrower jet, lower turbulence and lower viscous shear stress (VSS). The specific severe stenosis BAV model studied here showed reduced WSS due to reduction in non-fused leaflet mobility. Dilation of the aorta did not affect any turbulence or VSS, but reduced the WSS. In comparison with BAVs, TAVs have similar VSS values, but much smaller WSS and turbulence levels. These increased turbulence  and WSS levels in BAVs may play a key role in amplifying the biological responses of the ascending aorta wall and valvular leaflets, and support the hemodynamic underpinnings of BAV disease processes.

Reliability and validity of a brief method to assess nociceptive flexion reflex (NFR) threshold.

PubMed

Rhudy, Jamie L; France, Christopher R

2011-07-01

The nociceptive flexion reflex (NFR) is a physiological tool to study spinal nociception. However, NFR assessment can take several minutes and expose participants to repeated suprathreshold stimulations. The 4 studies reported here assessed the reliability and validity of a brief method to assess NFR threshold that uses a single ascending series of stimulations (Peak 1 NFR), by comparing it to a well-validated method that uses 3 ascending/descending staircases of stimulations (Staircase NFR). Correlations between the NFR definitions were high, were on par with test-retest correlations of Staircase NFR, and were not affected by participant sex or chronic pain status. Results also indicated the test-retest reliabilities for the 2 definitions were similar. Using larger stimulus increments (4 mAs) to assess Peak 1 NFR tended to result in higher NFR threshold estimates than using the Staircase NFR definition, whereas smaller stimulus increments (2 mAs) tended to result in lower NFR threshold estimates than the Staircase NFR definition. Neither NFR definition was correlated with anxiety, pain catastrophizing, or anxiety sensitivity. In sum, a single ascending series of electrical stimulations results in a reliable and valid estimate of NFR threshold. However, caution may be warranted when comparing NFR thresholds across studies that differ in the ascending stimulus increments. This brief method to assess NFR threshold is reliable and valid; therefore, it should be useful to clinical pain researchers interested in quickly assessing inter- and intra-individual differences in spinal nociceptive processes. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

Cardiovascular Involvement in Children with Osteogenesis Imperfecta

PubMed Central

Karamifar, Hamdollah; Ilkhanipoor, Homa; Ajami, Gholamhossein; Karamizadeh, Zohreh; Amirhakimi, Gholamhossein; Shakiba, Ali-Mohammad

2013-01-01

Objective Osteogenesis imperfecta is a hereditary disease resulting from mutation in type I procollagen genes. One of the extra skeletal manifestations of this disease is cardiac involvement. The prevalence of cardiac involvement is still unknown in the children with osteogenesis imperfecta. The present study aimed to investigate the prevalence of cardiovascular abnormalities in these patients. Methods 24 children with osteogenesis imperfecta and 24 normal children who were matched with the patients regarding sex and age were studied. In both groups, standard echocardiography was performed, and heart valves were investigated. Dimensions of left ventricle, aorta annulus, sinotubular junction, ascending and descending aorta were measured and compared between the two groups. Findings The results revealed no significant difference between the two groups regarding age, sex, ejection fraction, shortening fraction, mean of aorta annulus, sinotubular junction, ascending and descending aorta, but after correction based on the body surface area, dimensions of aorta annulus, sinotubular junction, ascending and descending aorta in the patients were significantly higher than those in the control group (P<0.05). Two (8.3%) patients had aortic insufficiency and five (20%) patients had tricuspid regurgitation, three of whom had gradient >25 mmHg and one patient had pulmonary insufficiency with indirect evidence of pulmonary hypertension. According to Z scores of aorta annulus, sinotubular junction and ascending aorta, 5, 3, and 1 out of 24 patients had Z scores >2 respectively. Conclusion The prevalence of valvular heart diseases and aortic root dilation was higher in children with osteogenesis imperfecta. In conclusion, cardiovascular investigation is recommended in these children. PMID:24800009

Why rainfall response to El Niño over Maritime Continent is weaker and non-uniform in boreal winter than in boreal summer

NASA Astrophysics Data System (ADS)

Jiang, Leishan; Li, Tim

2017-11-01

Why rainfall response to El Niño is uniform and stronger over the Maritime Continent (MC) during El Niño developing summer and fall but is weaker and non-uniform during El Niño mature winter is investigated through the diagnosis of anomalous large-scale circulation patterns and a local moisture budget analysis. It is found that when anomalous Walker cells across the equatorial Pacific and Indian Ocean are strengthened toward El Niño mature winter, a low-level ascending motion anomaly starts to develop over western MC in northern fall due to topographic lifting (near Sumatra) and anomalous wind convergence (near west Kalimantan). Easterly anomalies, as a part of an anomalous anticyclone in South China Sea (SCS) that is developed during El Niño and a part of the south-easterly from Java Sea associated with anomalous Walker Circulation, bump into the mountain ridge of Sumatra and induce ascending motion anomalies near Sumatra. Meanwhile, the anomalous north-easterly in the southern flank of the anomalous anticyclone over SCS and south-easterly over Java Sea converge into west Kalimantan, leading to ascending motion there. The anomalous ascending motion tend to advect mean moisture upward to moisten lower troposphere in situ. This low-level moistening eventually sets up a convectively unstable stratification and induces a positive precipitation anomaly in the western MC. How the mechanism discussed here is relevant to previous hypotheses and how processes during El Niño might differ during La Niña are discussed.

Blunt traumatic aortic injuries of the ascending aorta and aortic arch: a clinical multicentre study.

PubMed

Mosquera, Victor X; Marini, Milagros; Muñiz, Javier; Gulias, Daniel; Asorey-Veiga, Vanesa; Adrio-Nazar, Belen; Herrera, José M; Pradas-Montilla, Gonzalo; Cuenca, José J

2013-09-01

To report the clinical and radiological characteristics, management and outcomes of traumatic ascending aorta and aortic arch injuries. Historic cohort multicentre study including 17 major trauma patients with traumatic aortic injury from January 2000 to January 2011. The most common mechanism of blunt trauma was motor-vehicle crash (47%) followed by motorcycle crash (41%). Patients sustaining traumatic ascending aorta or aortic arch injuries presented a high proportion of myocardial contusion (41%); moderate or greater aortic valve regurgitation (12%); haemopericardium (35%); severe head injuries (65%) and spinal cord injury (23%). The 58.8% of the patients presented a high degree aortic injury (types III and IV). Expected in-hospital mortality was over 50% as defined by mean TRISS 59.7 (SD 38.6) and mean ISS 48.2 (SD 21.6) on admission. Observed in-hospital mortality was 53%. The cause of death was directly related to the ATAI in 45% of cases, head and abdominal injuries being the cause of death in the remaining 55% cases. Long-term survival was 46% at 1 year, 39% at 5 years, and 19% at 10 years. Traumatic aortic injuries of the ascending aorta/arch should be considered in any major thoracic trauma patient presenting cardiac tamponade, aortic valve regurgitation and/or myocardial contusion. These aortic injuries are also associated with a high incidence of neurological injuries, which can be just as lethal as the aortic injury, so treatment priorities should be modulated on an individual basis. Copyright © 2012 Elsevier Ltd. All rights reserved.

Quorum sensing control of Type VI secretion factors restricts the proliferation of quorum-sensing mutants

PubMed Central

Majerczyk, Charlotte; Schneider, Emily; Greenberg, E Peter

2016-01-01

Burkholderia thailandensis uses acyl-homoserine lactone-mediated quorum sensing systems to regulate hundreds of genes. Here we show that cell-cell contact-dependent type VI secretion (T6S) toxin-immunity systems are among those activated by quorum sensing in B. thailandensis. We also demonstrate that T6S is required to constrain proliferation of quorum sensing mutants in colony cocultures of a BtaR1 quorum-sensing signal receptor mutant and its parent. However, the BtaR1 mutant is not constrained by and outcompetes its parent in broth coculture, presumably because no cell contact occurs and there is a metabolic cost associated with quorum sensing gene activation. The increased fitness of the wild type over the BtaR1 mutant during agar surface growth is dependent on an intact T6SS-1 apparatus. Thus, quorum sensing activates B. thailandensis T6SS-1 growth inhibition and this control serves to police and constrain quorum-sensing mutants. This work defines a novel role for T6SSs in intraspecies mutant control. DOI: http://dx.doi.org/10.7554/eLife.14712.001 PMID:27183270

Active and Passive Remote Sensing of Ice.

DTIC Science & Technology

1984-09-01

This is a report on the progress that has been made in the study of active and passive remote sensing of ice during the period of February 1, 1984...the emissivities as functions of viewing angles and polarizations. They are used to interpret the passive microwave remote sensing data from

Six Degrees-of-Freedom Ascent Control for Small-Body Touch and Go

NASA Technical Reports Server (NTRS)

Blackmore, Lars James C.

2011-01-01

A document discusses a method of controlling touch and go (TAG) of a spacecraft to correct attitude, while ensuring a safe ascent. TAG is a concept whereby a spacecraft is in contact with the surface of a small body, such as a comet or asteroid, for a few seconds or less before ascending to a safe location away from the small body. The report describes a controller that corrects attitude and ensures that the spacecraft ascends to a safe state as quickly as possible. The approach allocates a certain amount of control authority to attitude control, and uses the rest to accelerate the spacecraft as quickly as possible in the ascent direction. The relative allocation to attitude and position is a parameter whose optimal value is determined using a ground software tool. This new approach makes use of the full control authority of the spacecraft to correct the errors imparted by the contact, and ascend as quickly as possible. This is in contrast to prior approaches, which do not optimize the ascent acceleration.

Trainable multiscript orientation detection

NASA Astrophysics Data System (ADS)

Van Beusekom, Joost; Rangoni, Yves; Breuel, Thomas M.

2010-01-01

Detecting the correct orientation of document images is an important step in large scale digitization processes, as most subsequent document analysis and optical character recognition methods assume upright position of the document page. Many methods have been proposed to solve the problem, most of which base on ascender to descender ratio computation. Unfortunately, this cannot be used for scripts having no descenders nor ascenders. Therefore, we present a trainable method using character similarity to compute the correct orientation. A connected component based distance measure is computed to compare the characters of the document image to characters whose orientation is known. This allows to detect the orientation for which the distance is lowest as the correct orientation. Training is easily achieved by exchanging the reference characters by characters of the script to be analyzed. Evaluation of the proposed approach showed accuracy of above 99% for Latin and Japanese script from the public UW-III and UW-II datasets. An accuracy of 98.9% was obtained for Fraktur on a non-public dataset. Comparison of the proposed method to two methods using ascender / descender ratio based orientation detection shows a significant improvement.

A Case of Echinostoma cinetorchis (Trematoda: Echinostomatidae) Infection Diagnosed by Colonoscopy

PubMed Central

Jung, Woon Tae; Lee, Kyeong Ju; Kim, Hong Jun; Kim, Tae Hyo; Na, Byoung-Kuk

2014-01-01

Human cases of echinostomiasis have been sporadically diagnosed by extracting worms in the endoscopy in Korea and Japan. Most of these were caused by Echinostoma hortense infection. However, in the present study, we detected 2 live worms of Echinostoma cinetorchis in the ascending colon of a Korean man (68-year old) admitted to the Gyeongsang National University Hospital with complaint of intermittent right lower quadrant abdominal pain for 5 days. Under colonoscopy, 1 worm was found attached on the edematous and hyperemic mucosal surface of the proximal ascending colon and the other was detected on the mid-ascending colon. Both worms were removed from the mucosal surface with a grasping forceps, and morphologically identified as E. cinetorchis by the characteristic head crown with total 37 collar spines including 5 end-group ones on both sides, disappearance of testes, and eggs of 108×60 µm with abopercular wrinkles. The infection source of this case seems to be the raw frogs eaten 2 months ago. This is the first case of endoscopy-diagnosed E. cinetorchis infection in Korea. PMID:25031469