HuPSON: the human physiology simulation ontology.

Science.gov (United States)

Gündel, Michaela; Younesi, Erfan; Malhotra, Ashutosh; Wang, Jiali; Li, Hui; Zhang, Bijun; de Bono, Bernard; Mevissen, Heinz-Theodor; Hofmann-Apitius, Martin

2013-11-22

Large biomedical simulation initiatives, such as the Virtual Physiological Human (VPH), are substantially dependent on controlled vocabularies to facilitate the exchange of information, of data and of models. Hindering these initiatives is a lack of a comprehensive ontology that covers the essential concepts of the simulation domain. We propose a first version of a newly constructed ontology, HuPSON, as a basis for shared semantics and interoperability of simulations, of models, of algorithms and of other resources in this domain. The ontology is based on the Basic Formal Ontology, and adheres to the MIREOT principles; the constructed ontology has been evaluated via structural features, competency questions and use case scenarios.The ontology is freely available at: http://www.scai.fraunhofer.de/en/business-research-areas/bioinformatics/downloads.html (owl files) and http://bishop.scai.fraunhofer.de/scaiview/ (browser). HuPSON provides a framework for a) annotating simulation experiments, b) retrieving relevant information that are required for modelling, c) enabling interoperability of algorithmic approaches used in biomedical simulation, d) comparing simulation results and e) linking knowledge-based approaches to simulation-based approaches. It is meant to foster a more rapid uptake of semantic technologies in the modelling and simulation domain, with particular focus on the VPH domain.

Nanoparticle-based capillary electroseparation of proteins in polymer capillaries under physiological conditions

DEFF Research Database (Denmark)

Nilsson, C.; Harwigsson, I.; Becker, K.

2010-01-01

Totally porous lipid-based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas (R), 6.7 cm effective length). In the absence of n...... at protein friendly conditions. The developed capillary-based method facilitates future electrochromatography of proteins on polymer-based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development....

Investigation of endothelial growth using a sensors-integrated microfluidic system to simulate physiological barriers

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Rajabi Taleieh

2015-09-01

Full Text Available In this paper we present a microfluidic system based on transparent biocompatible polymers with a porous membrane as substrate for various cell types which allows the simulation of various physiological barriers under continuous laminar flow conditions at distinct tunable shear rates. Besides live cell and fluorescence microscopy, integrated electrodes enable the investigation of the permeability and barrier function of the cell layer as well as their interaction with external manipulations using the Electric Cell-substrate Impedance Sensing (ECIS method.

Simulated Summer Rainfall Variability Effects on Loblolly Pine (Pinus taeda Seedling Physiology and Susceptibility to Root-Infecting Ophiostomatoid Fungi

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Jeff Chieppa

2017-03-01

Full Text Available Seedlings from four families of loblolly pine (Pinus taeda L. were grown in capped open-top chambers and exposed to three different weekly moisture regimes for 13 weeks. Moisture regimes varied in intensity and frequency of simulated rainfall (irrigation events; however, the total amounts were comparable. These simulated treatments were chosen to simulate expected changes in rainfall variability associated with climate change. Seedlings were inoculated with two root-infecting ophiostomatoid fungi associated with Southern Pine Decline. We found susceptibility of loblolly pine was not affected by water stress; however, one family that was most sensitive to inoculation was also most sensitive to changes in moisture availability. Many studies have examined the effects of drought (well-watered vs. dry conditions on pine physiology and host-pathogen interactions but little is known about variability in moisture supply. This study aimed to elucidate the effects of variability in water availability, pathogen inoculation and their interaction on physiology of loblolly pine seedlings.

Magnesium degradation under physiological conditions - Best practice.

Science.gov (United States)

Gonzalez, Jorge; Hou, Rui Qing; Nidadavolu, Eshwara P S; Willumeit-Römer, Regine; Feyerabend, Frank

2018-06-01

This review focusses on the application of physiological conditions for the mechanistic understanding of magnesium degradation. Despite the undisputed relevance of simplified laboratory setups for alloy screening purposes, realistic and predictive in vitro setups are needed. Due to the complexity of these systems, the review gives an overview about technical measures, defines some caveats and can be used as a guideline for the establishment of harmonized laboratory approaches.

Role of hypoxia and hypoxia inducible factor in physiological and pathological conditions

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Mozhgan Jahani

2017-11-01

Full Text Available Introduction: Organisms are exposed to oxygen deprivation (Hypoxia in various physiological and pathological conditions. There are different conserve evolutionary responses to counterview with this stress that primary transcriptional response to stress related to hypoxia is interceded by hypoxia-inducible factor (HIF-1 in mammals. This factor can regulate different genes that have essential roles in adaptation to this condition. In this review, the role of this factor in physiological and pathological conditions under hypoxic condition has been evaluated after examining structural features and regulation characteristics of HIF-1. Methods: First, articles related to the keywords of hypoxia and HIF-1 (from 1991-2016 were searched from valid databases such as Springer Link, Google Scholar, PubMed and Science direct. Then, the articles correlated with hypoxia, HIF-1 and their roles in physiological and pathological conditions (120 articles were searched and just 64 articles were selected for this study. Result: According to studies, there are different genes in cells and organs that can be regulated by HIF-1. Activation of genes expression by this protein occurs through its linkage to cis-acting of 50 base pair hypoxia response element (HRE region located in their promotor and enhancer. Depending on circumstances, activation of these genes can be beneficial or harmful. Conclusion: Activation of different genes in hypoxia by HIF-1 has different effects on physiological and pathological conditions. Therefore, HIF-1, as a hypoxia-inducible factor in hypoxic conditions, plays an essential role in the adaptation of cells and organs to changes related to the presence of oxygen.

Adding sleep restriction to the equation: impact on wildland firefighters' work performance and physiology in hot conditions.

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Vincent, Grace E; Ferguson, Sally; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Aisbett, Brad

2018-04-06

To examine the effects of sleep restriction on firefighters' physical task performance, physical activity, and physiological and perceived exertion during simulated hot wildfire conditions. 31 firefighters were randomly allocated to either the hot (n = 18, HOT; 33 °C, 8-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Intermittent, self-paced work circuits of six firefighting tasks were performed for 3 days. Firefighters self-reported ratings of perceived exertion. Heart rate, core temperature, and physical activity were measured continuously. Fluids were consumed ad libitum, and all food and fluids consumed were recorded. Urine volume and urine specific gravity (USG) were analysed and sleep was assessed using polysomnography (PSG). There were no differences between the HOT and HOT + SR groups in firefighters' physical task performance, heart rate, core temperature, USG, or fluid intake. Ratings of perceived exertion were higher (p HOT + SR group for two of the six firefighting tasks. The HOT group spent approximately 7 min more undertaking moderate physical activity throughout the 2-h work circuits compared to the HOT + SR group. Two nights of sleep restriction did not influence firefighters' physical task performance or physiological responses during 3 days of simulated wildfire suppression. Further research is needed to explore firefighters' pacing strategies during real wildfire suppression.

Host physiological condition regulates parasitic plant performance: Arceuthobium vaginatum subsp. cryptopodum on Pinus ponderosa.

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Bickford, Christopher P; Kolb, Thomas E; Geils, Brian W

2005-12-01

Much research has focused on effects of plant parasites on host-plant physiology and growth, but little is known about effects of host physiological condition on parasite growth. Using the parasitic dwarf mistletoe Arceuthobium vaginatum subsp. cryptopodum (Viscaceae) and its host Pinus ponderosa, we investigated whether changes in host physiological condition influenced mistletoe shoot development in northern Arizona forests. We conducted two studies in two consecutive years and used forest thinning (i.e., competitive release) to manipulate host physiological condition. We removed dwarf mistletoe shoots in April, before the onset of the growing season, and measured the amount of regrowth in the first season after forest thinning (Study I: n=38 trees; Study II: n=35 trees). Thinning increased tree uptake of water and carbon in both studies, but had no effect on leaf N concentration or delta13C. Mistletoe shoot growth was greater on trees with high uptake of water and carbon in thinned stands than trees with low uptake in unthinned stands. These findings show that increased resource uptake by host trees increases resources to these heterotrophic dwarf mistletoes, and links mistletoe performance to changes in host physiological condition.

PHYSIOLOGICAL AND SANITARY QUALITIES OF MAIZE LANDRACE SEEDS STORED UNDER TWO CONDITIONS

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Raquel Stefanello

2015-08-01

Full Text Available The preservation of seed quality during the storage period depends not only on the conditions during production and harvesting but also on the storage and maintenance of appropriate storage product conditions. Thus, the aim of this study was to evaluate the physiological and sanitary qualities of maize landrace seeds stored under two conditions. The maize seed batch varieties Oito carreiras, Cabo roxo and Lombo baio were used. Tests included germination, first count, cold test, accelerated aging and sanity. Based on the results it was concluded that the physiological quality of these seed varieties decreased with the storage period. The major fungi identified in the maize seeds during storage were from the genera Aspergillus, Fusarium and Penicillium, which caused deterioration and reduction of the physiological quality. Storage using a paper bag at a temperature of 10 °C did not prevent the deterioration of maize seeds but was more effective at preserving the quality of the seed compared with a plastic bag at room temperature.

Use of an iPad App to simulate pressure-volume loops and cardiovascular physiology.

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Leisman, Staci; Burkhoff, Daniel

2017-09-01

The purpose of this laboratory exercise is to model the changes in preload, afterload, and contractility on a simulated pressure-volume loop and to correlate those findings with common measurements of clinical cardiovascular physiology. Once students have modeled these changes on a healthy heart, the students are asked to look at a simulated case of cardiogenic shock. Effects on preload, contractility, and afterload are explored, as well as the hemodynamic effects of a number of student-suggested treatment strategies. Copyright © 2017 the American Physiological Society.

Real-time Continuous Assessment Method for Mental and Physiological Condition using Heart Rate Variability

Science.gov (United States)

Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

It is necessary to monitor the daily health condition for preventing stress syndrome. In this study, it was proposed the method assessing the mental and physiological condition, such as the work stress or the relaxation, using heart rate variability at real time and continuously. The instantanuous heart rate (HR), and the ratio of the number of extreme points (NEP) and the number of heart beats were calculated for assessing mental and physiological condition. In this method, 20 beats heart rate were used to calculate these indexes. These were calculated in one beat interval. Three conditions, which are sitting rest, performing mental arithmetic and watching relaxation movie, were assessed using our proposed algorithm. The assessment accuracies were 71.9% and 55.8%, when performing mental arithmetic and watching relaxation movie respectively. In this method, the mental and physiological condition was assessed using only 20 regressive heart beats, so this method is considered as the real time assessment method.

Elbow helical axes of motion are not the same in physiologic and kinetic joint simulators.

Science.gov (United States)

Muriuki, Muturi G; Mohagheh-Motlagh, Amin; Smolinski, Patrick J; Miller, Mark Carl

2012-08-31

Physiologic and kinetic joint simulators have been widely used for investigations of joint mechanics. The two types of simulator differ in the way joint motion is achieved; through prescribed motions and/or forces in kinetic joint simulators and by tendon loads in physiologic joint simulators. These two testing modalities have produced important insights, as in elucidating the importance of soft tissue structures to joint stability. However, the equivalence of the modalities has not been tested. This study sequentially tested five cadaveric elbows using both a physiologic simulator and a robot/6DOF system. Using position data from markers on the humerus and ulna, we calculated and compared the helical axes of motion of the specimens as the elbows were flexed from full extension. Six step size increments were used in the helical axis calculation. Marker position data at each test's full extension and full flexion point were also used to calculate a datum (overall) helical axis. The angles between the datum axis and step-wise movements were computed and stored. Increasing step size monotonically decreased the variability and the average conical angle encompassing the helical axes; a repeated measures ANOVA using test type (robot or physiologic simulator) and step size found that both type and step caused statistically significant differences (p<0.001). The large changes in helical axis angle observed for small changes in elbow flexion angle, especially in the robot tests, are a caveat for investigators using similar control algorithms. Controllers may need to include increased joint compliance and/or C(1) continuity to reduce variability. Copyright © 2012 Elsevier Ltd. All rights reserved.

Magnesium degradation under physiological conditions – Best practice

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Jorge Gonzalez

2018-06-01

Full Text Available This review focusses on the application of physiological conditions for the mechanistic understanding of magnesium degradation. Despite the undisputed relevance of simplified laboratory setups for alloy screening purposes, realistic and predictive in vitro setups are needed. Due to the complexity of these systems, the review gives an overview about technical measures, defines some caveats and can be used as a guideline for the establishment of harmonized laboratory approaches.

Physiological pattern changes in response to a simulated competition in elite women artistic gymnasts.

Science.gov (United States)

Isacco, Laurie; Ennequin, Gaël; Cassirame, Johan; Tordi, Nicolas

2017-08-04

The outstanding progress in women's artistic gymnastics in recent decades has led to increased technical and physiological demands. The aim of this study was to investigate i) the physiological demands of elite French gymnasts and ii) the impact of a competitive routine on physiological pattern changes. Fourteen French elite female gymnasts performed anthropometric measurements, physical fitness tests and a simulated four event competition. Heart rate (HR) was continuously recorded throughout the duration of the simulated competition. Blood lactate concentrations were assessed at rest, before the beginning and at 2, 4 and 10 min after completion of the routine on each apparatus. Isometric handgrip strength and anaerobic endurance and power were assessed during the simulated competition. The highest values of HR and blood lactate concentrations were reached during the floor and uneven bar exercises. Blood lactate concentrations and HR kinetics were apparatus dependent and values remained significantly increased at 10 min of recovery compared with resting data. Anaerobic endurance and power decreased significantly as the competition progressed (P <0.001). The present results show specifically cardiorespiratory and anaerobic apparatus- dependent responses throughout a simulated competition. Recovery approaches appear relevant to prevent and/or minimize fatigue and optimize performance in these athletes.

Method and Apparatus for Encouraging Physiological Self-Regulation Through Modulation of an Operator's Control Input to a Video Game or Training Simulator

Science.gov (United States)

Palsson, Olafur S. (Inventor); Harris, Randall L., Sr. (Inventor); Pope, Alan T. (Inventor)

2002-01-01

Apparatus and methods for modulating the control authority (i.e., control function) of a computer simulation or game input device (e.g., joystick, button control) using physiological information so as to affect the user's ability to impact or control the simulation or game with the input device. One aspect is to use the present invention, along with a computer simulation or game, to affect physiological state or physiological self-regulation according to some programmed criterion (e.g., increase, decrease, or maintain) in order to perform better at the game task. When the affected physiological state or physiological self-regulation is the target of self-regulation or biofeedback training, the simulation or game play reinforces therapeutic changes in the physiological signal(s).

Effects of steering demand on lane keeping behaviour, self-reports, and physiology. A simulator study.

Science.gov (United States)

Dijksterhuis, Chris; Brookhuis, Karel A; De Waard, Dick

2011-05-01

In this study a driving simulator was used to determine changes in mental effort in response to manipulations of steering demand. Changes in mental effort were assessed by using subjective effort ratings, physiology, and the standard deviation of the lateral position. Steering demand was increased by exposure to narrow lane widths and high density oncoming traffic while speed was fixed in all conditions to prevent a compensatory reaction. Results indicated that both steering demand factors influence mental effort expenditure and using multiple measures contributes to effort assessment. Application of these outcomes for adaptive automation is envisaged. Copyright © 2010 Elsevier Ltd. All rights reserved.

[Physiological aspects of altitude training and the use of altitude simulators].

Science.gov (United States)

Ranković, Goran; Radovanović, Dragan

2005-01-01

Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatisation, which improves oxygen transport and/or utilisation, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training through hypoxia), and live high and train low (the new trend). In an effort to reduce the financial and logistical challenges of travelling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters). Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarised.

Physiological aspects of altitude training and the use of altitude simulators

Directory of Open Access Journals (Sweden)

Ranković Goran

2005-01-01

Full Text Available Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training, live low and train high (training through hypoxia, and live high and train low (the new trend. In an effort to reduce the financial and logistical challenges of traveling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters. Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarized.

The corrosion resistance of Nitinol alloy in simulated physiological solutions

International Nuclear Information System (INIS)

Milošev, Ingrid; Kapun, Barbara

2012-01-01

The corrosion behaviour of Nitinol alloy containing nearly equi-atomic composition of nickel and titanium and its constituent metals (nickel and titanium) was investigated in simulated Hanks physiological solution (pH value 7.5) and pH modified simulated Hanks physiological solution (pH values 4.5 and 6.5) and by electrochemical method of anodic potentiodynamic polarization at 37 °C. In this chloride-rich medium the corrosion stability of Nitinol is limited by the susceptibility to localized corrosion and is in that sense more similar to nickel than to titanium. The corrosion stability of Nitinol is strongly dependent on the surface preparation—grinding, polishing or chemical etching. Whereas a ground surface is not resistant to localized corrosion, polished and chemically etched surfaces are resistant to this type of corrosion attack. The reasons for this behaviour were investigated through metallurgical, topographical and chemical properties of the surface as a function of surface preparation. For that purpose, scanning electron microscopy combined with chemical analysis, confocal microscopy and X-ray photoelectron spectroscopy were used. The surface roughness decreased in the following order: chemically etched > ground > polished surface. Besides differences in topography, distinct differences in the chemical composition of the outermost surface are observed. Ground, rough surfaces comprised mainly titanium oxides and small amounts of nickel metal. Chemically etched and, especially, polished surfaces are composed of a mixture of titanium, nickel and titanium oxides, as studied by angle resolved X-ray photoelectron spectroscopy. These results emphasize the importance of detailed investigation of the metal surface since small differences in surface preparation may induce large differences in corrosion stability of material when exposed to corrosive environments. - Highlights: ► The corrosion resistance of Nitinol is dependent on the surface preparation. �

Study of Physiological Responses to Acute Carbon Monoxide Exposure with a Human Patient Simulator

Science.gov (United States)

Cesari, Whitney A.; Caruso, Dominique M.; Zyka, Enela L.; Schroff, Stuart T.; Evans, Charles H., Jr.; Hyatt, Jon-Philippe K.

2006-01-01

Human patient simulators are widely used to train health professionals and students in a clinical setting, but they also can be used to enhance physiology education in a laboratory setting. Our course incorporates the human patient simulator for experiential learning in which undergraduate university juniors and seniors are instructed to design,…

The effect of biomolecules on the behaviour of CoCrMo alloy in various simulated physiological solutions

International Nuclear Information System (INIS)

Milošev, Ingrid

2012-01-01

Highlights: ► The behaviour of CoCrMo alloy is investigated in four simulated physiological solutions. ► The effect of synovial fluid significantly differs from the effect of organic components hitherto studied. ► In the presence of organic components carbon and nitrogen containing species are formed. ► Composition, structure and thickness of surface layers were determined by XPS. - Abstract: CoCrMo orthopaedic alloy was oxidized potentiostatically in various simulated physiological solutions in order to reveal differences in the composition, thickness and structure of the surface layers formed as a function of solution composition. X-ray photoelectron spectroscopy, combined with angle-resolved measurements and depth profiling, was used for the purpose. The following simulated physiological solutions were used: (1) 0.9% NaCl, (2) simulated Hanks physiological solution containing various inorganic salts, (3) simulated Hanks physiological solution containing an aliquot of synovial fluid retrieved at a primary operation, and (4) minimum essential medium containing various inorganic salts, amino acids and vitamins. No significant differences between alloy treated in these solutions were observed after oxidation in the passive region; the oxide films are a few nanometres thick and, except in NaCl solution, contain a small amount of calcium phosphate. After oxidation at a potential in the transpassive range, however, the oxide thickness increases considerably due to incorporation of cobalt and molybdenum oxides. Further, the concentration of calcium phosphate increases. The layers formed in minimum essential medium and Hanks solution containing synovial fluid comprise nitrogen and carbon containing species. The addition of synovial fluid significantly affects the behaviour in Hanks solution.

Assessment of physiological performance and perception of pushing different wheelchairs on indoor modular units simulating a surface roughness often encountered in under-resourced settings.

Science.gov (United States)

Sasaki, Kotaro; Rispin, Karen

2017-01-01

In under-resourced settings where motorized wheelchairs are rarely available, manual wheelchair users with limited upper-body strength and functionalities need to rely on assisting pushers for their mobility. Because traveling surfaces in under-resourced settings are often unpaved and rough, wheelchair pushers could experience high physiological loading. In order to evaluate pushers' physiological loading and to improve wheelchair designs, we built indoor modular units that simulate rough surface conditions, and tested a hypothesis that pushing different wheelchairs would result in different physiological performances and pushers' perception of difficulty on the simulated rough surface. Eighteen healthy subjects pushed two different types of pediatric wheelchairs (Moti-Go manufactured by Motivation, and KidChair by Hope Haven) fitted with a 50-kg dummy on the rough and smooth surfaces at self-selected speeds. Oxygen uptake, traveling distance for 6 minutes, and the rating of difficulty were obtained. The results supported our hypothesis, showing that pushing Moti-Go on the rough surface was physiologically less loading than KidChair, but on the smooth surface, the two wheelchairs did not differ significantly. These results indicate wheelchair designs to improve pushers' performance in under-resourced settings should be evaluated on rough surfaces.

Habitat and sex differences in physiological condition of breeding Southwestern Willow Flycatchers (Empidonax traillii extimus)

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Owen, J.C.; Sogge, M.K.; Kern, M.D.

2005-01-01

The Southwestern Willow Flycatcher (Empidonax traillii extimus; here- after “flycatcher”) is a federally listed endangered species that breeds in densely vegetated riparian habitats dominated by native and exotic plants, including introduced monotypic saltcedar (Tamarix ramosissima). Some workers have theorized that saltcedar is unsuitable habitat for the flycatcher, primarily because it generally supports a smaller and less diverse invertebrate community (the flycatcher's food base) than native habitats (e.g. Salix spp.). However, differences in insect communities between native and saltcedar habitats are not proof that saltcedar habitats are inferior. The only way to evaluate whether the habitats differ in dietary or energetic quality is to document actual food limitation or its manifestations. Measurements of an individual's body condition and metabolic state can serve as indicators of environmental stressors, such as food limitation and environmental extremes. We captured 130 flycatchers breeding in native and saltcedar habitats in Arizona and New Mexico and measured 12 variables of physiological condition. These variables included body mass, fat level, body condition index, hematocrit, plasma triglycerides, plasma free fatty acids and glycerol, plasma glucose and beta-hydroxybutyrate, plasma uric acid, total leukocyte count, and heterophil-to-lymphocyte ratio. We found substantial sex-based differences in the condition of male and female flycatchers. Ten of the 12 measures of physiological condition differed significantly between the sexes. In all cases where male and female condition differed (except mass), the differences suggest that males were in poorer condition than females. We found few habitat-based differences in flycatcher condition. Only 3 of the 12 physiological condition indices differed significantly between habitats. Our data show that, at least in some parts of the flycatcher's range, there is no evidence that flycatchers breeding in

PHYSIOLOGICAL MONITORING OPERATORS ACS IN AUDIO-VISUAL SIMULATION OF AN EMERGENCY

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S. S. Aleksanin

2010-01-01

Full Text Available In terms of ship simulator automated control systems we have investigated the information content of physiological monitoring cardiac rhythm to assess the reliability and noise immunity of operators of various specializations with audio-visual simulation of an emergency. In parallel, studied the effectiveness of protection against the adverse effects of electromagnetic fields. Monitoring of cardiac rhythm in a virtual crash it is possible to differentiate the degree of voltage regulation systems of body functions of operators on specialization and note the positive effect of the use of means of protection from exposure of electromagnetic fields.

Simulated physiological stretch increases expression of extracellular matrix proteins in human bladder smooth muscle cells via integrin α4/αv-FAK-ERK1/2 signaling pathway.

Science.gov (United States)

Chen, Shulian; Peng, Chuandu; Wei, Xin; Luo, Deyi; Lin, Yifei; Yang, Tongxin; Jin, Xi; Gong, Lina; Li, Hong; Wang, Kunjie

2017-08-01

To investigate the effect of simulated physiological stretch on the expression of extracellular matrix (ECM) proteins and the role of integrin α4/αv, focal adhesion kinase (FAK), extracellular regulated protein kinases 1/2 (ERK1/2) in the stretch-induced ECM protein expression of human bladder smooth muscle cells (HBSMCs). HBSMCs were seeded onto silicone membrane and subjected to simulated physiological stretch at the range of 5, 10, and 15% elongation. Expression of primary ECM proteins in HBSMCs was analyzed by real-time polymerase chain reaction and Western blot. Specificity of the FAK and ERK1/2 was determined by Western blot with FAK inhibitor and ERK1/2 inhibitor (PD98059). Specificity of integrin α4 and integrin αv was determined with small interfering ribonucleic acid (siRNA) transfection. The expression of collagen I (Col1), collagen III (Col3), and fibronectin (Fn) was increased significantly under the simulated physiological stretch of 10 and 15%. Integrin α4 and αv, FAK, ERK1/2 were activated by 10% simulated physiological stretch compared with the static condition. Pretreatment of ERK1/2 inhibitor, FAK inhibitor, integrin α4 siRNA, or integrin αv siRNA reduced the stretch-induced expression of ECM proteins. And FAK inhibitor decreased the stretch-induced ERK1/2 activity and ECM protein expression. Integrin α4 siRNA or integrin αv siRNA inhibited the stretch-induced activity of FAK. Simulated physiological stretch increases the expression of ECM proteins in HBSMCs, and integrin α4/αv-FAK-ERK1/2 signaling pathway partly modulates the mechano-transducing process.

Pathways of the Maillard reaction under physiological conditions.

Science.gov (United States)

Henning, Christian; Glomb, Marcus A

2016-08-01

Initially investigated as a color formation process in thermally treated foods, nowadays, the relevance of the Maillard reaction in vivo is generally accepted. Many chronic and age-related diseases such as diabetes, uremia, atherosclerosis, cataractogenesis and Alzheimer's disease are associated with Maillard derived advanced glycation endproducts (AGEs) and α-dicarbonyl compounds as their most important precursors in terms of reactivity and abundance. However, the situation in vivo is very challenging, because Maillard chemistry is paralleled by enzymatic reactions which can lead to both, increases and decreases in certain AGEs. In addition, mechanistic findings established under the harsh conditions of food processing might not be valid under physiological conditions. The present review critically discusses the relevant α-dicarbonyl compounds as central intermediates of AGE formation in vivo with a special focus on fragmentation pathways leading to formation of amide-AGEs.

Single-sector thermophysiological human simulator

International Nuclear Information System (INIS)

Psikuta, Agnieszka; Richards, Mark; Fiala, Dusan

2008-01-01

Thermal sweating manikins are used to analyse the heat and mass transfer phenomena in the skin–clothing–environment system. However, the limiting factor of present thermal manikins is their inability to simulate adequately the human thermal behaviour, which has a significant effect on the clothing microenvironment. A mathematical model of the human physiology was, therefore, incorporated into the system control to simulate human thermoregulatory responses and the perception of thermal comfort over a wide range of environmental and personal conditions. Thereby, the computer model provides the physiological intelligence, while the hardware is used to measure the required calorimetric states relevant to the human heat exchange with the environment. This paper describes the development of a single-sector thermophysiological human simulator, which consists of a sweating heated cylinder 'Torso' coupled with the iesd-Fiala multi-node model of human physiology and thermal comfort. Validation tests conducted for steady-state and, to some extent, transient conditions ranging from cold to hot revealed good agreement with the corresponding experimental results obtained for semi-nude subjects. The new coupled system enables overall physiological and comfort responses, health risk and survival conditions to be predicted for adult humans for various scenarios

Homologous Basal Ganglia Network Models in Physiological and Parkinsonian Conditions

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Jyotika Bahuguna

2017-08-01

Full Text Available The classical model of basal ganglia has been refined in recent years with discoveries of subpopulations within a nucleus and previously unknown projections. One such discovery is the presence of subpopulations of arkypallidal and prototypical neurons in external globus pallidus, which was previously considered to be a primarily homogeneous nucleus. Developing a computational model of these multiple interconnected nuclei is challenging, because the strengths of the connections are largely unknown. We therefore use a genetic algorithm to search for the unknown connectivity parameters in a firing rate model. We apply a binary cost function derived from empirical firing rate and phase relationship data for the physiological and Parkinsonian conditions. Our approach generates ensembles of over 1,000 configurations, or homologies, for each condition, with broad distributions for many of the parameter values and overlap between the two conditions. However, the resulting effective weights of connections from or to prototypical and arkypallidal neurons are consistent with the experimental data. We investigate the significance of the weight variability by manipulating the parameters individually and cumulatively, and conclude that the correlation observed between the parameters is necessary for generating the dynamics of the two conditions. We then investigate the response of the networks to a transient cortical stimulus, and demonstrate that networks classified as physiological effectively suppress activity in the internal globus pallidus, and are not susceptible to oscillations, whereas parkinsonian networks show the opposite tendency. Thus, we conclude that the rates and phase relationships observed in the globus pallidus are predictive of experimentally observed higher level dynamical features of the physiological and parkinsonian basal ganglia, and that the multiplicity of solutions generated by our method may well be indicative of a natural

A simulated avalanche search and rescue mission induces temporary physiological and behavioural changes in military dogs.

Science.gov (United States)

Diverio, Silvana; Barbato, Olimpia; Cavallina, Roberta; Guelfi, Gabriella; Iaboni, Martina; Zasso, Renato; Di Mari, Walter; Santoro, Michele Matteo; Knowles, Toby G

2016-09-01

Saving human lives is of paramount importance in avalanche rescue missions. Avalanche military dogs represent an invaluable resource in these operations. However, their performance can be influenced by several environmental, social and transport challenges. If too severe, these are likely to activate a range of responses to stress, which might put at risk the dogs' welfare. The aim of this study was to assess the physiological and behavioural responses of a group of military dogs to a Simulated Avalanche Search and Rescue mission (SASR). Seventeen avalanche dogs from the Italian Military Force Guardia di Finanza (SAGF dogs) were monitored during a simulated search for a buried operator in an artificial avalanche area (SASR). Heart rate (HR), body temperature (RBT) and blood samples were collected at rest the day before the trial (T0), immediately after helicopter transport at the onset of the SASR (T1), after the discovery of the buried operator (T2) and 2h later (T3). Heart rate (HR), rectal body temperature (RBT), cortisol, aspartate aminotransferase (AST), creatine kinase (CK), non-esterified fatty acids (NEFA) and lactate dehydrogenase (LDH) were measured. During the search mission the behaviour of each SAGF dog was measured by focal animal sampling and qualitatively assessed by its handler and two observers. Inter-rater agreement was evaluated. Snow and environmental variables were also measured. All dogs successfully completed their search for the buried, simulated victim within 10min. The SASR was shown to exert significant increases on RBT, NEFA and cortisol (Pdog's search mission ability was found only for motivation, signalling behaviour, signs of stress and possessive reward playing. More time signalling was related to shorter search time. In conclusion, despite extreme environmental and training conditions only temporary physiological and behavioural changes were recorded in the avalanche dogs. Their excellent performance in successful simulated SASR

Comparative study; physiological and biochemical parameters of normal and induced dehydrated condition of rabbits

International Nuclear Information System (INIS)

Bashir, S.; Bukhari, I.

2008-01-01

Biochemical and physiological parameters like body weight, blood pH. Blood glucose, total lipids total protein, globulin, albumin and albumin/globulin ratio were determined in twelve rabbits each normal and after the induction of diseased condition i.e. dehydration. Statistically significant differences were identified when the comparison made between normal rabbits and their respective dehydrated group. Blood glucose total lipid packed cell. Volume and globulin increased significantly where where as body weight, albumin and albumin/globulin ratio decreased significantly. These differences in the physiological and biochemical parameters in disease induced condition require the necessity for analyzing this condition for the changes in the pharmacokinetics parameter like, absorption distribution metabolism and excretion leading to alteration in the pharmacokinetics of drug. (author)

Physiological basis of barley yield under near optimal and stress conditions

Directory of Open Access Journals (Sweden)

Pržulj Novo

2004-01-01

Full Text Available Average barley yield fall below its potential due to incidence of stresses. Water stress is the main environmental factor limiting yield. The component a priori more sensitive to most stresses is the amount of radiation absorbed. The effect of stresses influence on the total amount of radiation absorbed by barley crop during its vegetation and the photosynthetic efficiency of radiation conversion. Growth inhibition is accompanied by reductions in leaf and cell wall extensibility. Grain yield under drought conditions is source limited. Supply of assimilates to the developing inflorescence plays a critical role in establishing final grain number and grain size. Grain weight is negatively affected by drought, high temperature, and any other factors that may reduce grain filling duration and grain filling rate. Awns and glaucousness confer better performance of barley under drought stress conditions. Barley responds with an increased accumulation of a number of proteins when subjected to different stress inducing cell dehydration. Screening techniques that are able to identify desirable genotypes based on the evaluation of physiological traits related to stress evasion and stress resistance maybe useful in breeding barley for resistance to stress, particularly drought stress. Crop management and breeding can reduce the incidence of stress on yield. The effect of these practices is sustained by an understanding of their physiology. In this paper the physiological basis of the processes determining barley yield and the incidence of stresses on photosynthetic metabolism that determine grain yield of barley is discussed. .

Psychological and physiological human responses to simulated and real environments: A comparison between Photographs, 360° Panoramas, and Virtual Reality.

Science.gov (United States)

Higuera-Trujillo, Juan Luis; López-Tarruella Maldonado, Juan; Llinares Millán, Carmen

2017-11-01

Psychological research into human factors frequently uses simulations to study the relationship between human behaviour and the environment. Their validity depends on their similarity with the physical environments. This paper aims to validate three environmental-simulation display formats: photographs, 360° panoramas, and virtual reality. To do this we compared the psychological and physiological responses evoked by simulated environments set-ups to those from a physical environment setup; we also assessed the users' sense of presence. Analysis show that 360° panoramas offer the closest to reality results according to the participants' psychological responses, and virtual reality according to the physiological responses. Correlations between the feeling of presence and physiological and other psychological responses were also observed. These results may be of interest to researchers using environmental-simulation technologies currently available in order to replicate the experience of physical environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physiological responses to simulated stair climbing in professional firefighters wearing rubber and leather boots.

Science.gov (United States)

Huang, Chun-Jung; Garten, Ryan S; Wade, Chip; Webb, Heather E; Acevedo, Edmund O

2009-09-01

No studies have considered whether a firefighter's boots are a factor influencing physiological responses. The purpose of this study was to examine physiological responses to a fire simulation activity (stair climb) in professional firefighters wearing rubber boots (RB) and leather boots (LB). Twelve professional firefighters participated in two counterbalanced simulated firefighter stair climb (SFSC) sessions, one wearing RB and the other wearing LB. Heart rate, oxygen uptake (VO(2)), expiratory ventilation (V(E)), blood lactate (BLa), salivary cortisol (SCORT), and leg strength were assessed prior to and following a SFSC. LB elicited significantly greater SCORT values and knee flexion time to peak torque. Furthermore, RB revealed significantly greater ankle dorsiflexion peak torque after SFSC. BLa was positively related to knee flexion peak torque after SFSC in the RB. Firefighters when wearing the RB may be more effective at resisting fatigue and increase more force production.

Investigation of an alternative generic model for predicting pharmacokinetic changes during physiological stress.

Science.gov (United States)

Peng, Henry T; Edginton, Andrea N; Cheung, Bob

2013-10-01

Physiologically based pharmacokinetic models were developed using MATLAB Simulink® and PK-Sim®. We compared the capability and usefulness of these two models by simulating pharmacokinetic changes of midazolam under exercise and heat stress to verify the usefulness of MATLAB Simulink® as a generic PBPK modeling software. Although both models show good agreement with experimental data obtained under resting condition, their predictions of pharmacokinetics changes are less accurate in the stressful conditions. However, MATLAB Simulink® may be more flexible to include physiologically based processes such as oral absorption and simulate various stress parameters such as stress intensity, duration and timing of drug administration to improve model performance. Further work will be conducted to modify algorithms in our generic model developed using MATLAB Simulink® and to investigate pharmacokinetics under other physiological stress such as trauma. © The Author(s) 2013.

Developing Physiologic Models for Emergency Medical Procedures Under Microgravity

Science.gov (United States)

Parker, Nigel; O'Quinn, Veronica

2012-01-01

Several technological enhancements have been made to METI's commercial Emergency Care Simulator (ECS) with regard to how microgravity affects human physiology. The ECS uses both a software-only lung simulation, and an integrated mannequin lung that uses a physical lung bag for creating chest excursions, and a digital simulation of lung mechanics and gas exchange. METI s patient simulators incorporate models of human physiology that simulate lung and chest wall mechanics, as well as pulmonary gas exchange. Microgravity affects how O2 and CO2 are exchanged in the lungs. Procedures were also developed to take into affect the Glasgow Coma Scale for determining levels of consciousness by varying the ECS eye-blinking function to partially indicate the level of consciousness of the patient. In addition, the ECS was modified to provide various levels of pulses from weak and thready to hyper-dynamic to assist in assessing patient conditions from the femoral, carotid, brachial, and pedal pulse locations.

Physiological responses of astronaut candidates to simulated +Gx orbital emergency re-entry.

Science.gov (United States)

Wu, Bin; Xue, Yueying; Wu, Ping; Gu, Zhiming; Wang, Yue; Jing, Xiaolu

2012-08-01

We investigated astronaut candidates' physiological and pathological responses to +Gx exposure during simulated emergency return from a running orbit to advance astronaut +Gx tolerance training and medical support in manned spaceflight. There were 13 male astronaut candidates who were exposed to a simulated high +Gx acceleration profile in a spacecraft during an emergency return lasting for 230 s. The peak value was 8.5 G. Subjective feelings and symptoms, cardiovascular and respiratory responses, and changes in urine component before, during, and after +Gx exposure were investigated. Under high +Gx exposure, 15.4% of subjects exhibited arrhythmia. Heart rate (HR) increased significantly and four different types of HR response curves were distinguished. The ratio of QT to RR interval on the electrocardiograms was significantly increased. Arterial oxygen saturation (SaO2) declined with increasing G value and then returned gradually. SaO2 reached a minimum (87.7%) at 3 G during the decline phase of the +Gx curve. Respiratory rate increased significantly with increasing G value, while the amplitude and area of the respiratory waves were significantly reduced. The overshoot appeared immediately after +Gx exposure. A few subjects suffered from slight injuries, including positive urine protein (1/13), positive urinary occult blood (1/13), and a large area of petechiae on the back (1/13). Astronaut candidates have relatively good tolerance to the +Gx profile during a simulation of spacecraft emergent ballistic re-entry. However, a few subjects exhibited adverse physiological responses and slight reversible pathological injuries.

A DYNAMIC PHYSIOLOGICALLY-BASED TOXICOKINETIC (DPBTK) MODEL FOR SIMULATION OF COMPLEX TOLUENE EXPOSURE SCENARIOS IN HUMANS

Science.gov (United States)

A GENERAL PHYSIOLOGICAL AND TOXICOKINETIC (GPAT) MODEL FOR SIMULATION OF COMPLEX TOLUENE EXPOSURE SCENARIOS IN HUMANS. E M Kenyon1, T Colemen2, C R Eklund1 and V A Benignus3. 1U.S. EPA, ORD, NHEERL, ETD, PKB, RTP, NC, USA; 2Biological Simulators, Inc., Jackson MS, USA, 3U.S. EP...

Salt- and pH-Triggered Helix-Coil Transition of Ionic Polypeptides under Physiology Conditions.

Science.gov (United States)

Yuan, Jingsong; Zhang, Yi; Sun, Yue; Cai, Zhicheng; Yang, Lijiang; Lu, Hua

2018-06-11

Controlling the helix-coil transition of polypeptides under physiological conditions is an attractive way toward smart functional materials. Here, we report the synthesis of a series of tertiary amine-functionalized ethylene glycol (EG x )-linked polypeptide electrolytes with their secondary structures tunable under physiological conditions. The resultant polymers, denoted as P(EG x DMA-Glu) ( x = 1, 2, and 3), show excellent aqueous solubility (>20 mg/mL) regardless of their charge states. Unlike poly-l-lysine that can form a helix only at pH above 10, P(EG x DMA-Glu) undergo a pH-dependent helix-coil switch with their transition points within the physiological range (pH ∼5.3-6.5). Meanwhile, P(EG x DMA-Glu) exhibit an unusual salt-induced helical conformation presumably owing to the unique properties of EG x linkers. Together, the current work highlights the importance of fine-tuning the linker chemistry in achieving conformation-switchable polypeptides and represents a facile approach toward stimuli-responsive biopolymers for advanced biological applications.

Thermal Simulations, Open Boundary Conditions and Switches

Science.gov (United States)

Burnier, Yannis; Florio, Adrien; Kaczmarek, Olaf; Mazur, Lukas

2018-03-01

SU(N) gauge theories on compact spaces have a non-trivial vacuum structure characterized by a countable set of topological sectors and their topological charge. In lattice simulations, every topological sector needs to be explored a number of times which reflects its weight in the path integral. Current lattice simulations are impeded by the so-called freezing of the topological charge problem. As the continuum is approached, energy barriers between topological sectors become well defined and the simulations get trapped in a given sector. A possible way out was introduced by Lüscher and Schaefer using open boundary condition in the time extent. However, this solution cannot be used for thermal simulations, where the time direction is required to be periodic. In this proceedings, we present results obtained using open boundary conditions in space, at non-zero temperature. With these conditions, the topological charge is not quantized and the topological barriers are lifted. A downside of this method are the strong finite-size effects introduced by the boundary conditions. We also present some exploratory results which show how these conditions could be used on an algorithmic level to reshuffle the system and generate periodic configurations with non-zero topological charge.

Thermal Simulations, Open Boundary Conditions and Switches

Directory of Open Access Journals (Sweden)

Burnier Yannis

2018-01-01

Full Text Available SU(N gauge theories on compact spaces have a non-trivial vacuum structure characterized by a countable set of topological sectors and their topological charge. In lattice simulations, every topological sector needs to be explored a number of times which reflects its weight in the path integral. Current lattice simulations are impeded by the so-called freezing of the topological charge problem. As the continuum is approached, energy barriers between topological sectors become well defined and the simulations get trapped in a given sector. A possible way out was introduced by Lüscher and Schaefer using open boundary condition in the time extent. However, this solution cannot be used for thermal simulations, where the time direction is required to be periodic. In this proceedings, we present results obtained using open boundary conditions in space, at non-zero temperature. With these conditions, the topological charge is not quantized and the topological barriers are lifted. A downside of this method are the strong finite-size effects introduced by the boundary conditions. We also present some exploratory results which show how these conditions could be used on an algorithmic level to reshuffle the system and generate periodic configurations with non-zero topological charge.

The effect of physiological conditions on the surface structure of proteins: Setting the scene for human digestion of emulsions

Science.gov (United States)

Maldonado-Valderrama, J.; Gunning, A. P.; Ridout, M. J.; Wilde, P. J.; Morris, V. J.

2009-10-01

Understanding and manipulating the interfacial mechanisms that control human digestion of food emulsions is a crucial step towards improved control of dietary intake. This article reports initial studies on the effects of the physiological conditions within the stomach on the properties of the film formed by the milk protein ( β -lactoglobulin) at the air-water interface. Atomic force microscopy (AFM), surface tension and surface rheology techniques were used to visualize and examine the effect of gastric conditions on the network structure. The effects of changes in temperature, pH and ionic strength on a pre-formed interfacial structure were characterized in order to simulate the actual digestion process. Changes in ionic strength had little effect on the surface properties. In isolation, acidification reduced both the dilatational and the surface shear modulus, mainly due to strong repulsive electrostatic interactions within the surface layer and raising the temperature to body temperature accelerated the rearrangements within the surface layer, resulting in a decrease of the dilatational response and an increase of surface pressure. Together pH and temperature display an unexpected synergism, independent of the ionic strength. Thus, exposure of a pre-formed interfacial β -lactoglobulin film to simulated gastric conditions reduced the surface dilatational modulus and surface shear moduli. This is attributed to a weakening of the surface network in which the surface rearrangements of the protein prior to exposure to gastric conditions might play a crucial role.

Estimation of the physiological mechanical conditioning in vascular tissue engineering by a predictive fluid-structure interaction approach.

Science.gov (United States)

Tresoldi, Claudia; Bianchi, Elena; Pellegata, Alessandro Filippo; Dubini, Gabriele; Mantero, Sara

2017-08-01

The in vitro replication of physiological mechanical conditioning through bioreactors plays a crucial role in the development of functional Small-Caliber Tissue-Engineered Blood Vessels. An in silico scaffold-specific model under pulsatile perfusion provided by a bioreactor was implemented using a fluid-structure interaction (FSI) approach for viscoelastic tubular scaffolds (e.g. decellularized swine arteries, DSA). Results of working pressures, circumferential deformations, and wall shear stress on DSA fell within the desired physiological range and indicated the ability of this model to correctly predict the mechanical conditioning acting on the cells-scaffold system. Consequently, the FSI model allowed us to a priori define the stimulation pattern, driving in vitro physiological maturation of scaffolds, especially with viscoelastic properties.

Quantitative Circulatory Physiology: an integrative mathematical model of human physiology for medical education.

Science.gov (United States)

Abram, Sean R; Hodnett, Benjamin L; Summers, Richard L; Coleman, Thomas G; Hester, Robert L

2007-06-01

We have developed Quantitative Circulatory Physiology (QCP), a mathematical model of integrative human physiology containing over 4,000 variables of biological interactions. This model provides a teaching environment that mimics clinical problems encountered in the practice of medicine. The model structure is based on documented physiological responses within peer-reviewed literature and serves as a dynamic compendium of physiological knowledge. The model is solved using a desktop, Windows-based program, allowing students to calculate time-dependent solutions and interactively alter over 750 parameters that modify physiological function. The model can be used to understand proposed mechanisms of physiological function and the interactions among physiological variables that may not be otherwise intuitively evident. In addition to open-ended or unstructured simulations, we have developed 30 physiological simulations, including heart failure, anemia, diabetes, and hemorrhage. Additional stimulations include 29 patients in which students are challenged to diagnose the pathophysiology based on their understanding of integrative physiology. In summary, QCP allows students to examine, integrate, and understand a host of physiological factors without causing harm to patients. This model is available as a free download for Windows computers at http://physiology.umc.edu/themodelingworkshop.

Simulated Exercise Physiology Laboratories.

Science.gov (United States)

Morrow, James R., Jr.; Pivarnik, James M.

This book consists of a lab manual and computer disks for either Apple or IBM hardware. The lab manual serves as "tour guide" for the learner going through the various lab experiences. The manual contains definitions, proper terminology, and other basic information about physiological principles. It is organized so a step-by-step procedure may be…

Automated Boundary Conditions for Wind Tunnel Simulations

Science.gov (United States)

Carlson, Jan-Renee

2018-01-01

Computational fluid dynamic (CFD) simulations of models tested in wind tunnels require a high level of fidelity and accuracy particularly for the purposes of CFD validation efforts. Considerable effort is required to ensure the proper characterization of both the physical geometry of the wind tunnel and recreating the correct flow conditions inside the wind tunnel. The typical trial-and-error effort used for determining the boundary condition values for a particular tunnel configuration are time and computer resource intensive. This paper describes a method for calculating and updating the back pressure boundary condition in wind tunnel simulations by using a proportional-integral-derivative controller. The controller methodology and equations are discussed, and simulations using the controller to set a tunnel Mach number in the NASA Langley 14- by 22-Foot Subsonic Tunnel are demonstrated.

Effects of Ionizing Irradiation on Mushrooms as Influenced by Physiological and Environmental Conditions

DEFF Research Database (Denmark)

Skou, Jens-Peder; Bech, K.; Lundsten, K.

1974-01-01

The effects of irradiation with β (10 MeV fast electrons)- and γ-rays were studied on several characters in strains of the cultured mushroom under different physiological and environmental conditions, including uncut and cut mushrooms, tightness of packing, and relative humidity. Weight loss was ...

The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

International Nuclear Information System (INIS)

Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun

2013-01-01

The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta power ratio is

Experience with simulator training for emergency conditions

International Nuclear Information System (INIS)

1987-12-01

The training of operators by the use of simulators is common to most countries with nuclear power plants. Simulator training programmes are generally well developed, but their value can be limited by the age, type, size and capability of the simulator. Within these limits, most full scope simulators have a capability of training operators for a range of design basis accidents. It is recognized that human performance under accident conditions is difficult to predict or analyse, particularly in the area of severe accidents. These are rare events and by their very nature, unpredictable. Of importance, therefore, is to investigate the training of operators for severe accident conditions, and to examine ways in which simulators may be used in this task. The International Nuclear Safety Advisory Group (INSAG) has reviewed this field and the associated elements of human behaviour. It has recommended that activities are concentrated on this area. Initially it is encouraging the following objectives: i) To train operators for accident conditions including severe accidents and to strongly encourage the development and use of simulators for this purpose; ii) To improve the man-machine interface by the use of computer aids to the operator; iii) To develop human performance requirements for plant operating staff. As part of this work, the IAEA convened a technical committee on 15-19 September 1986 to review the experience with simulator training for emergency conditions, to review simulator modelling for severe accident training, to examine the role of human cognitive behaviour modelling, and to review guidance on accident scenarios. A substantial deviation may be a major fuel failure, a Loss of Coolant Accident (LOCA), etc. Examples of engineered safety features are: an Emergency Core Cooling System (ECCS), and Containment Systems. This report was prepared by the participants during the meeting and reviewed further in a Consultant's Meeting. It also includes papers which were

Custom AFM for X-ray beamlines: in situ biological investigations under physiological conditions

Energy Technology Data Exchange (ETDEWEB)

Gumí-Audenis, B. [ESRF, The European Synchrotron, Grenoble (France); Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Carlà, F. [ESRF, The European Synchrotron, Grenoble (France); Vitorino, M. V. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Panzarella, A. [ESRF, The European Synchrotron, Grenoble (France); Porcar, L. [Institut Laue-Langevin, Grenoble (France); Boilot, M. [ORTEC, Marseille (France); Guerber, S. [CEA, LETI Grenoble (France); Bernard, P. [ESRF, The European Synchrotron, Grenoble (France); Rodrigues, M. S. [University of Lisboa, Falculty of Science, Biosystems and Integrative Sciences Institute - BIOISI, Lisbon (Portugal); Sanz, F.; Giannotti, M. I. [Institute for Bioengineering of Catalonia (IBEC), Barcelona (Spain); Physical Chemistry Department, Universitat de Barcelona, Barcelona (Spain); Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain); Costa, L., E-mail: luca.costa@esrf.fr [ESRF, The European Synchrotron, Grenoble (France)

2015-09-30

The performance of a custom atomic force microscope for grazing-incidence X-ray experiments on hydrated soft and biological samples is presented. A fast atomic force microscope (AFM) has been developed that can be installed as a sample holder for grazing-incidence X-ray experiments at solid/gas or solid/liquid interfaces. It allows a wide range of possible investigations, including soft and biological samples under physiological conditions (hydrated specimens). The structural information obtained using the X-rays is combined with the data gathered with the AFM (morphology and mechanical properties), providing a unique characterization of the specimen and its dynamics in situ during an experiment. In this work, lipid monolayers and bilayers in air or liquid environment have been investigated by means of AFM, both with imaging and force spectroscopy, and X-ray reflectivity. In addition, this combination allows the radiation damage induced by the beam on the sample to be studied, as has been observed on DOPC and DPPC supported lipid bilayers under physiological conditions.

The link between antioxidant enzymes catalase and glutathione S-transferase and physiological condition of a control population of terrestrial isopod (Porcellio scaber).

Science.gov (United States)

Jemec, Anita; Lešer, Vladka; Drobne, Damjana

2012-05-01

The aim of this work was to investigate if the activities of catalase and glutathione S-transferase in a control population of terrestrial isopods (Porcellio scaber) are correlated with the physiological condition of the isopods. For this purpose, the activities of these enzymes were analysed in isopods from a stock population and in parallel, the physiological condition of the same specimens was assessed using a histological approach based on epithelial thickness and lipid droplets. We found a correlation between antioxidant enzymes and the physiological condition of the isopods. This implies that these enzymes could be used as predictive indicators of the physiological condition in a stock population before comprehensive toxicological studies are conducted and also in control group after the experiment. When a control group is found to be very heterogeneous in terms of physiological condition, the experiment should be repeated with a larger number of experimental animals. The findings of this study will contribute to more accurate experimental design of toxicity tests when using biomarkers. This should encourage other researchers to increase their effort to know the physiological state of their test organisms. Copyright © 2011 Elsevier Inc. All rights reserved.

An integrated approach to develop, validate and operate thermo-physiological human simulator for the development of protective clothing.

Science.gov (United States)

Psikuta, Agnes; Koelblen, Barbara; Mert, Emel; Fontana, Piero; Annaheim, Simon

2017-12-07

Following the growing interest in the further development of manikins to simulate human thermal behaviour more adequately, thermo-physiological human simulators have been developed by coupling a thermal sweating manikin with a thermo-physiology model. Despite their availability and obvious advantages, the number of studies involving these devices is only marginal, which plausibly results from the high complexity of the development and evaluation process and need of multi-disciplinary expertise. The aim of this paper is to present an integrated approach to develop, validate and operate such devices including technical challenges and limitations of thermo-physiological human simulators, their application and measurement protocol, strategy for setting test scenarios, and the comparison to standard methods and human studies including details which have not been published so far. A physical manikin controlled by a human thermoregulation model overcame the limitations of mathematical clothing models and provided a complementary method to investigate thermal interactions between the human body, protective clothing, and its environment. The opportunities of these devices include not only realistic assessment of protective clothing assemblies and equipment but also potential application in many research fields ranging from biometeorology, automotive industry, environmental engineering, and urban climate to clinical and safety applications.

Effects of steering demand on lane keeping behaviour, self-reports, and physiology : A simulator study

NARCIS (Netherlands)

Dijksterhuis, Chris; Brookhuis, Karel A.; De Waard, Dick

In this study a driving simulator was used to determine changes in mental effort in response to manipulations of steering demand. Changes in mental effort were assessed by using subjective effort ratings, physiology, and the standard deviation of the lateral position. Steering demand was increased

Simulations of QCD and QED with C* boundary conditions

Science.gov (United States)

Hansen, Martin; Lucini, Biagio; Patella, Agostino; Tantalo, Nazario

2018-03-01

We present exploratory results from dynamical simulations of QCD in isolation, as well as QCD coupled to QED, with C* boundary conditions. In finite volume, the use of C* boundary conditions allows for a gauge invariant and local formulation of QED without zero modes. In particular we show that the simulations reproduce known results and that masses of charged mesons can be extracted in a completely gauge invariant way. For the simulations we use a modified version of the HiRep code. The primary features of the simulation code are presented and we discuss some details regarding the implementation of C* boundary conditions and the simulated lattice action. Preprint: CP3-Origins-2017-046 DNRF90, CERN-TH-2017-214

Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

Science.gov (United States)

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological responses

Response of HEPA filters to simulated-accident conditions

International Nuclear Information System (INIS)

Gregory, W.S.; Martin, R.A.; Smith, P.R.; Fenton, D.E.

1982-01-01

High-efficiency particulate air (HEPA) filters have been subjected to simulated accident conditions to determine their response to abnormal operating events. Both domestic and European standard and high-capacity filters have been evaluated to determine their response to simulated fire, explosion, and tornado conditions. The HEPA filter structural limitations for tornado and explosive loadings are discussed. In addition, filtration efficiencies during these accident conditions are reported for the first time. Our data indicate efficiencies between 80% and 90% for shock loadings below the structural limit level. We describe two types of testing for ineffective filtration - clean filters exposed to pulse-entrained aerosol and dirty filters exposed to tornado and shock pulses. Efficiency and material loss data are described. Also, the resonse of standard HEPA filters to simulated fire conditions is presented. We describe a unique method of measuring accumulated combustion products on the filter. Additionally, data relating to pressure drop vs accumulated mass during plugging are reported for simulated combustion aerosols. The effects of concentration and moisture levels on filter plugging were evaluated. We are obtaining all of the above data so that mathematical models can be developed for fire, explosion, and tornado accident analysis computer codes. These computer codes can be used to assess the response of nuclear air cleaning systems to accident conditions

Milk Production, Physiological Condition and Performance of Etawa Crossbreed Goats Feed by Ration Supplemented with Mangosteen Peel Flour

Science.gov (United States)

Dzarnisa; Rachmadi, D.; Azhar, A.; Fakhrur Riza, R.; Hidayati, A.

2018-02-01

Study on the effect of the addition of mangosteen (Garcinia mangostana L.) peel flour on physiological condition and performance of Etawa crossbreed goats was done. This was to grant the use of mangosteen peel flour that rich of antioxidants and has variety good benefits for health as feed additive for cattle. This study used a Complete Randomized Block Design consisting of 4 treatment groups and 4 replications each. Subjects were 16 female Etawa crossbreed goats randomly designed into treatments group based on lactation periods. Subjects were feed with traditional rations (control, A), traditional rations and 2.5% mangosteen peel flour (B), tradition rations and 5% mangosteen peel flour (C), and traditional rations and 7,5 % mangosteen peel flour (D). Data on performance (milk production) and physiological condition (respiratory frequency, rectal temperature, and heart rate) obtained were analyzed using analysis of variance (ANOVA). The results showed that the addition of mangosteen peel flour as food additive in the rations resulted in variations in the milk production, physiological condition (rectal temperature, heart rate and respiration frequency) and performances (daily weigh gain, food consumption, ration conversion and breast volume) of Etawa crossbreed goats, but significant effect was only observed in the respiration frequency. The addition of 2.5% mangosteen peel flour in the ration caused the best, expected effects on milk production physiological condition and performance of Etawa crossbreed goats.

Physiologically Modulating Videogames or Simulations which Use Motion-Sensing Input Devices

Science.gov (United States)

Pope, Alan T. (Inventor); Stephens, Chad L. (Inventor); Blanson, Nina Marie (Inventor)

2017-01-01

New types of controllers allow a player to make inputs to a video game or simulation by moving the entire controller itself or by gesturing or by moving the player's body in whole or in part. This capability is typically accomplished using a wireless input device having accelerometers, gyroscopes, and a camera. The present invention exploits these wireless motion-sensing technologies to modulate the player's movement inputs to the videogame based upon physiological signals. Such biofeedback-modulated video games train valuable mental skills beyond eye-hand coordination. These psychophysiological training technologies enhance personal improvement, not just the diversion, of the user.

The energetic, physiological, and behavioral response of lemon sharks (Negaprion brevirostris) to simulated longline capture.

Science.gov (United States)

Bouyoucos, Ian A; Suski, Cory D; Mandelman, John W; Brooks, Edward J

2017-05-01

Commercial fisheries bycatch is a considerable threat to elasmobranch population recovery, and techniques to mitigate sub-lethal consequences can be improved with data on the energetic, physiological, and behavioral response of individuals to capture. This study sought to estimate the effects of simulated longline capture on the behavior, energy use, and physiological stress of juvenile lemon sharks (Negaprion brevirostris). Captive sharks equipped with acceleration biologgers were subjected to 1h of simulated longline capture. Swimming behaviors were identified from acceleration data using a machine-learning algorithm, energetic costs were estimated using accelerometer-calibrated relationships and respirometry, and physiological stress was quantified with point-of-care blood analyzers. During capture, sharks exhibited nine-fold increases in the frequency of burst swimming, 98% reductions in resting, and swam as often as unrestrained sharks. Aerobic metabolic rates during capture were 8% higher than for unrestrained sharks, and accounted for a 57.7% increase in activity costs when excess post-exercise oxygen consumption was included. Lastly, sharks exhibited significant increases in blood lactate and glucose, but no change in blood pH after 1h of capture. Therefore, these results provide preliminary insight into the behavioral and energetic responses of sharks to capture, and have implications for mitigating sub-lethal consequences of capture for sharks as commercial longline bycatch. Copyright © 2017 Elsevier Inc. All rights reserved.

The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2013-05-15

The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation.

Directory of Open Access Journals (Sweden)

Garth Herring

Full Text Available The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba and white ibises (Eudocimus albus to changing prey availability, hydrology (water depth, recession rate, and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index and fecal corticosterone levels (medium-term were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70 in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A.; Gawlik, Dale E.; Beerens, James M.; Ackerman, Joshua T.

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

Physiological condition of juvenile wading birds in relation to multiple landscape stressors in the Florida Everglades: effects of hydrology, prey availability, and mercury bioaccumulation.

Science.gov (United States)

Herring, Garth; Eagles-Smith, Collin A; Gawlik, Dale E; Beerens, James M; Ackerman, Joshua T

2014-01-01

The physiological condition of juvenile birds can be influenced by multiple ecological stressors, and few studies have concurrently considered the effects of environmental contaminants in combination with ecological attributes that can influence foraging conditions and prey availability. Using three temporally distinct indices of physiological condition, we compared the physiological response of nestling great egrets (Ardea alba) and white ibises (Eudocimus albus) to changing prey availability, hydrology (water depth, recession rate), and mercury exposure in the Florida Everglades. We found that the physiological response of chicks varied between species and among environmental variables. Chick body condition (short-term index) and fecal corticosterone levels (medium-term) were influenced by wetland water depth, prey availability, region, and age, but not by mercury contamination. However, mercury exposure did influence heat shock protein 70 (HSP70) in egret chicks, indicating a longer-term physiological response to contamination. Our results indicate that the physiological condition of egret and ibis chicks were influenced by several environmental stressors, and the time frame of the effect may depend on the specialized foraging behavior of the adults provisioning the chicks.

DISAIN SIMULATOR AUTOMOTIVE AIR CONDITIONING UNTUK MENINGKATKAN KOMPETENSI MAHASISWA

Directory of Open Access Journals (Sweden)

Kamin Sumardi

2015-08-01

Full Text Available Perkembangan teknologi automotive air conditioning dan aplikasinya sangat cepat, salah satunya dengan menerapkan green technology. Penerapan green technology pada teknologi air conditioning, karena masih menggunakan refrigeran yang mengandung unsur kimia yang merusak lapisan ozon dan pemanasan global. Alih teknologi bidang air conditioning yang ramah lingkungan, belum dibarengi dengan ketersediaan tenaga kerja pada tingkat SMK dan perguruan tinggi yang memadai, baik kuantitas maupun kompetensinya. Pada level SMK dan perguruan tinggi, kompetensi akademik dan vokasional bidang automotive air conditioning harus terus ditingkatkan dan diperbaharui sesuai dengan perkembangan teknologinya. Penelitian ini bertujuan untuk menghasilkan simulator automotive air conditioner dan model pembelajaran tata udara pada otomotif berwawasan teknologi ramah lingkungan. Penelitian menggunakan metode research and development dengan langkah-langkah: studi pendahuluan, perencanaan, pengembangan melalui uji coba simulator, validasi, dan produk akhir. Simulator dibuat sesuai dengan kondisi di dunia kerja agar tidak terjadi miskonsepsi dan mala-praktek automotive air conditioning. Simulator ini dibuat secara kompak dan mobile atau dapat dipindah dan dibawa. Model pembelajaran disesuaikan dengan kebutuhan kompetensi yang dipersyaratkan. Hasil penelitian menunjukkan bahwa dengan bantuan simulator automotive air conditioner dan model pembelajaran yang tepat mahasiswa mampu menyerap konsep dan praktek lebih cepat 85%. Hasil belajar pada ranah afektif, kognitif, psikomotor dan kompetensi meningkat secara signifikan.

Chemical method of labelling proteins with the radionuclides of technetium at physiological condition

International Nuclear Information System (INIS)

Wong, D.W.

1983-01-01

A novel rapid chemical method of labeling plasma proteins, other compounds and/or substances containing protein with radionuclides of technetium such as sup(95m)Tc, sup(99m)Tc or sup(99)Tc at physiologic pH 7.4 condition, producing a sterile non-pyrogenic radioactive tracer material suitable for biological and medical uses. These radiolabeled protein substances are not denatured by the labeling process but retain their natural physiological and immunological properties. This novel labeling technique provides a simple and rapid means of labeling plasma proteins such as human serum albumin, fibrinogen, antibodies, hormones and enzymes with sup(95m)Tc or sup(99m)Tc for scintigraphic imaging which may allow visualization of thrombi, emboli, myocardial infarcts, infectious lesions or tumors

Intraspecific Variation in Physiological Condition of Reef-Building Corals Associated with Differential Levels of Chronic Disturbance

Science.gov (United States)

Pisapia, Chiara; Anderson, Kristen; Pratchett, Morgan S.

2014-01-01

Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density) through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis), subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, pzooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, p<0.02, B =  −7386077, p = 0.01). Conversely, P. damicornis exhibited very limited intraspecific variation in physiological condition, despite marked differences in levels of partial mortality. This is the first study to relate intraspecific variation in the condition of corals to localized differences in chronic disturbance regimes. The next step is to ascertain whether these differences have further ramifications for susceptibility to periodic acute disturbances, such as climate-induced coral bleaching. PMID:24626395

Relativistic initial conditions for N-body simulations

Energy Technology Data Exchange (ETDEWEB)

Fidler, Christian [Catholic University of Louvain—Center for Cosmology, Particle Physics and Phenomenology (CP3) 2, Chemin du Cyclotron, B-1348 Louvain-la-Neuve (Belgium); Tram, Thomas; Crittenden, Robert; Koyama, Kazuya; Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth PO1 3FX (United Kingdom); Rampf, Cornelius, E-mail: christian.fidler@uclouvain.be, E-mail: thomas.tram@port.ac.uk, E-mail: rampf@thphys.uni-heidelberg.de, E-mail: robert.crittenden@port.ac.uk, E-mail: kazuya.koyama@port.ac.uk, E-mail: david.wands@port.ac.uk [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, D–69120 Heidelberg (Germany)

2017-06-01

Initial conditions for (Newtonian) cosmological N-body simulations are usually set by re-scaling the present-day power spectrum obtained from linear (relativistic) Boltzmann codes to the desired initial redshift of the simulation. This back-scaling method can account for the effect of inhomogeneous residual thermal radiation at early times, which is absent in the Newtonian simulations. We analyse this procedure from a fully relativistic perspective, employing the recently-proposed Newtonian motion gauge framework. We find that N-body simulations for ΛCDM cosmology starting from back-scaled initial conditions can be self-consistently embedded in a relativistic space-time with first-order metric potentials calculated using a linear Boltzmann code. This space-time coincides with a simple ''N-body gauge'' for z < 50 for all observable modes. Care must be taken, however, when simulating non-standard cosmologies. As an example, we analyse the back-scaling method in a cosmology with decaying dark matter, and show that metric perturbations become large at early times in the back-scaling approach, indicating a breakdown of the perturbative description. We suggest a suitable ''forwards approach' for such cases.

Physiological responses and performance in a simulated trampoline gymnastics competition in elite male gymnasts

DEFF Research Database (Denmark)

Jensen, Peter; Scott, Suzanne; Krustrup, Peter

2013-01-01

Abstract Physiological responses and performance were examined during and after a simulated trampoline competition (STC). Fifteen elite trampoline gymnasts participated, of which whereas eight completed two routines (EX1 and EX2) and a competition final (EX3). Trampoline-specific activities were...... gymnastic competition includes a high number of repeated explosive and energy demanding jumps, which impairs jump performance during and 24 h post-competition....

Dynamics of food availability, body condition and physiological stress response in breeding Black-legged Kittiwakes

Science.gov (United States)

Kitaysky, A.S.; Wingfield, J.C.; Piatt, John F.

1999-01-01

1. The seasonal dynamics of body condition (BC), circulating corticosterone levels (baseline, BL) and the adrenocortical response to acute stress (SR) were examined in long-lived Black-legged Kittiwakes, Rissa tridactyla, breeding at Duck (food-poor colony) and Gull (food-rich colony) Islands in lower Cook Inlet, Alaska. It was tested whether the dynamics of corticosterone levels reflect a seasonal change in bird physiological condition due to reproduction and/or variation in foraging conditions. 2. BC declined seasonally, and the decline was more pronounced in birds at the food-poor colony. BL and SR levels of corticosterone rose steadily through the reproductive season, and BL levels were significantly higher in birds on Duck island compared with those on Gull Island. During the egg-laying and chick-rearing stages, birds had lower SR on Duck Island than on Gull Island. 3. The results suggest that, in addition to a seasonal change in bird physiology during reproduction, local ecological factors such as food availability affect circulating levels of corticosterone and adrenal response to acute stress.

Physiological responses of genotypes soybean to simulated drought stress

Directory of Open Access Journals (Sweden)

Eleonóra Krivosudská

2016-12-01

Full Text Available The objective of this research was to investigate possible genetic variation in the sensitivity of soybean cultivars for nitrogen fixation rates in response to soil drying. The work confirmed that the selected physiological characteristics (RWC, osmotic potential, stress index and created nodules on roots are good evaluating parameters for the determination of water stress in plant. In the floricultural year 2014 an experiment with four genetic resources of soybean was launched. Sowing of Maverick (USA, Drina (HRV, Nigra (SVK and Polanka (CZK genotypes was carried out in the containers of 15 l capacity. This stress had a negative impact on the physiological parameters. By comparing the RWC values, the decrease was more significant at the end of dehydration, which was monitored in Maverick and Drina genotypes using the Nitrazon inoculants and water stress effect. Inoculated stressed Nigra and Polanka genotypes have kept higher water content till the end of dehydration period. Also the proline accumulation was monitored during the water stress, whilst higher content of free proline reached of Maverick. More remarkable decrease of osmotic potential was again registered in a foreign Drina and Maverick genotypes in the inoculated variations. Nigra and Polanka genotypes responses not so significant in the given conditions.

Exercise physiology with a left ventricular assist device: Analysis of heart-pump interaction with a computational simulator.

Science.gov (United States)

Fresiello, Libera; Rademakers, Frank; Claus, Piet; Ferrari, Gianfranco; Di Molfetta, Arianna; Meyns, Bart

2017-01-01

Patients with a Ventricular Assist Device (VAD) are hemodynamically stable but show an impaired exercise capacity. Aim of this work is to identify and to describe the limiting factors of exercise physiology with a VAD. We searched for data concerning exercise in heart failure condition and after VAD implantation from the literature. Data were analyzed by using a cardiorespiratory simulator that worked as a collector of inputs coming from different papers. As a preliminary step the simulator was used to reproduce the evolution of hemodynamics from rest to peak exercise (ergometer cycling) in heart failure condition. Results evidence an increase of cardiac output of +2.8 l/min and a heart rate increase to 67% of the expected value. Then, we simulated the effect of a continuous-flow VAD at both rest and exercise. Total cardiac output increases of +3.0 l/min (+0.9 l/min due to the VAD and +2.1 l/min to the native ventricle). Since the left ventricle works in a non-linear portion of the diastolic stiffness line, we observed a consistent increase of pulmonary capillary wedge pressure (from 14 to 20 mmHg) for a relatively small increase of end-diastolic volume (from 182 to 189 cm3). We finally increased VAD speed during exercise to the maximum possible value and we observed a reduction of wedge pressure (-4.5 mmHg), a slight improvement of cardiac output (8.0 l/min) and a complete unloading of the native ventricle. The VAD can assure a proper hemodynamics at rest, but provides an insufficient unloading of the left ventricle and does not prevent wedge pressure from rising during exercise. Neither the VAD provides major benefits during exercise in terms of total cardiac output, which increases to a similar extend to an unassisted heart failure condition. VAD speed modulation can contribute to better unload the ventricle but the maximal flow reachable with the current devices is below the cardiac output observed in a healthy heart.

Numerical simulation of meteorological conditions for peak pollution in Paris

Energy Technology Data Exchange (ETDEWEB)

Carissimo, B. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

1997-06-01

Results obtained on the simulation of meteorological conditions during two episodes of peak pollution in Paris are presented, one in the winter, the other in the summer. The A3UR air quality modelling system is first described followed by the MERCURE mesoscale meteorological model. The conditions of simulation are described. The results obtained on these two causes show satisfactory agreement, for example on the magnitude of the urban heat island which is correctly reproduced. In this study, several areas of progress have been identified: improvement of the altitude measurement network around cities, the simulation of light wind conditions and the simulation of formation and dissipation of fog. (author) 24 refs.

An Integrated Simulation Tool for Modeling the Human Circulatory System

Science.gov (United States)

Asami, Ken'ichi; Kitamura, Tadashi

This paper presents an integrated simulation of the circulatory system in physiological movement. The large circulatory system model includes principal organs and functional units in modules in which comprehensive physiological changes such as nerve reflexes, temperature regulation, acid/base balance, O2/CO2 balance, and exercise are simulated. A beat-by-beat heart model, in which the corresponding electrical circuit problems are solved by a numerical analytic method, enables calculation of pulsatile blood flow to the major organs. The integration of different perspectives on physiological changes makes this simulation model applicable for the microscopic evaluation of blood flow under various conditions in the human body.

A Simulated Heat Wave Has Diverse Effects on Immune Function and Oxidative Physiology in the Corn Snake (Pantherophis guttatus).

Science.gov (United States)

Stahlschmidt, Z R; French, S S; Ahn, A; Webb, A; Butler, M W

Animals will continue to encounter increasingly warm environments, including more frequent and intense heat waves. Yet the physiological consequences of heat waves remain equivocal, potentially because of variation in adaptive plasticity (reversible acclimation) and/or aspects of experimental design. Thus, we measured a suite of physiological variables in the corn snake (Pantherophis guttatus) after exposure to field-parameterized, fluctuating temperature regimes (moderate temperature and heat wave treatments) to address two hypotheses: (1) a heat wave causes physiological stress, and (2) thermal performance of immune function exhibits adaptive plasticity in response to a heat wave. We found little support for our first hypothesis because a simulated heat wave had a negative effect on body mass, but it also reduced oxidative damage and did not affect peak performance of three immune metrics. Likewise, we found only partial support for our second hypothesis. After exposure to a simulated heat wave, P. guttatus exhibited greater performance breadth and reduced temperature specialization (the standardized difference between peak performance and performance breadth) for only one of three immune metrics and did so in a sex-dependent manner. Further, a simulated heat wave did not elicit greater performance of any immune metric at higher temperatures. Yet a heat wave likely reduced innate immune function in P. guttatus because each metric of innate immune performance in this species (as in most vertebrates) was lower at elevated temperatures. Together with previous research, our study indicates that a heat wave may have complex, modest, and even positive physiological effects in some taxa.

On the role of numerical simulations in studies of reduced gravity-induced physiological effects in humans. Results from NELME.

Science.gov (United States)

Perez-Poch, Antoni

Computer simulations are becoming a promising research line of work, as physiological models become more and more sophisticated and reliable. Technological advances in state-of-the-art hardware technology and software allow nowadays for better and more accurate simulations of complex phenomena, such as the response of the human cardiovascular system to long-term exposure to microgravity. Experimental data for long-term missions are difficult to achieve and reproduce, therefore the predictions of computer simulations are of a major importance in this field. Our approach is based on a previous model developed and implemented in our laboratory (NELME: Numercial Evaluation of Long-term Microgravity Effects). The software simulates the behaviour of the cardiovascular system and different human organs, has a modular archi-tecture, and allows to introduce perturbations such as physical exercise or countermeasures. The implementation is based on a complex electrical-like model of this control system, using inexpensive development frameworks, and has been tested and validated with the available experimental data. The objective of this work is to analyse and simulate long-term effects and gender differences when individuals are exposed to long-term microgravity. Risk probability of a health impairement which may put in jeopardy a long-term mission is also evaluated. . Gender differences have been implemented for this specific work, as an adjustment of a number of parameters that are included in the model. Women versus men physiological differences have been therefore taken into account, based upon estimations from the physiology bibliography. A number of simulations have been carried out for long-term exposure to microgravity. Gravity varying continuosly from Earth-based to zero, and time exposure are the two main variables involved in the construction of results, including responses to patterns of physical aerobic ex-ercise and thermal stress simulating an extra

NMR spectroscopic studies of intrinsically disordered proteins at near-physiological conditions

International Nuclear Information System (INIS)

Gil, S.; Kummerle, S.; Hosek, T.; Pierattelli, R.; Felli, I.C.; Solyom, Z.; Brutscher, B.

2013-01-01

We have shown here that 13 C-start 13 -C detected experiments do not suffer from fast hydrogen exchange between amide and solvent protons in IDP samples studied at close to physiological conditions, thus enabling us to recover information that would be difficult or even impossible to obtain through amide 1 H-detected experiments. Furthermore, in favourable cases the fast hydrogen exchange rates can even be turned into a spectroscopic advantage. By combining longitudinal 1 H relaxation optimized BEST-type techniques with 13 C-direct detection pulse schemes, important sensitivity improvements can be achieved, and experimental times can be significantly reduced. This opens up new applications for monitoring chemical shift changes in IDPs upon interaction to a binding partner, chemical modification, or by changing the environment, under sample conditions that were inaccessible by conventional techniques. (authors)

Effects of the initial conditions on cosmological $N$-body simulations

OpenAIRE

L'Huillier, Benjamin; Park, Changbom; Kim, Juhan

2014-01-01

Cosmology is entering an era of percent level precision due to current large observational surveys. This precision in observation is now demanding more accuracy from numerical methods and cosmological simulations. In this paper, we study the accuracy of $N$-body numerical simulations and their dependence on changes in the initial conditions and in the simulation algorithms. For this purpose, we use a series of cosmological $N$-body simulations with varying initial conditions. We test the infl...

Life under Multiple Extreme Conditions: Diversity and Physiology of the Halophilic Alkalithermophiles

Science.gov (United States)

Wiegel, Juergen

2012-01-01

Around the world, there are numerous alkaline, hypersaline environments that are heated either geothermally or through intense solar radiation. It was once thought that such harsh environments were inhospitable and incapable of supporting a variety of life. However, numerous culture-dependent and -independent studies revealed the presence of an extensive diversity of aerobic and anaerobic bacteria and archaea that survive and grow under these multiple harsh conditions. This diversity includes the halophilic alkalithermophiles, a novel group of polyextremophiles that require for growth and proliferation the multiple extremes of high salinity, alkaline pH, and elevated temperature. Life under these conditions undoubtedly involves the development of unique physiological characteristics, phenotypic properties, and adaptive mechanisms that enable control of membrane permeability, control of intracellular osmotic balance, and stability of the cell wall, intracellular proteins, and other cellular constituents. This minireview highlights the ecology and growth characteristics of the extremely halophilic alkalithermophiles that have been isolated thus far. Biochemical, metabolic, and physiological properties of the extremely halophilic alkalithermophiles are described, and their roles in resistance to the combined stressors of high salinity, alkaline pH, and high temperature are discussed. The isolation of halophilic alkalithermophiles broadens the physicochemical boundaries for life and extends the boundaries for the combinations of the maximum salinity, pH, and temperature that can support microbial growth. PMID:22492435

Study on human physiological parameters for monitoring of mental works in the nuclear power plant

International Nuclear Information System (INIS)

Takano, Ken-ichi; Yoshino, Kenji; Ishii, Keiichiro; Nakasa, Hiroyasu; Shigeta, Sadayoshi.

1982-01-01

To prevent outbreaks of the wrong operation and judgement in the nuclear power plant, human conditions of body and mind should be taken into consideration particularly for the mental works such as inspection and monitoring. To estimate human conditions quantitatively by the measurement of human physiological parameters, this paper presents the following experimental results. (1) Physiological parameters are estimated from both sides of biological meanings and the applicability to field works. (2) Time variation of the parameters is investigated in mental simulation tests in order to select a good indicator of mental fatigue. (3) Correlation analysis between mental fatigue indexes and physiological parameters shows that the heart rate is a best indicator. (author)

Discretely Integrated Condition Event (DICE) Simulation for Pharmacoeconomics.

Science.gov (United States)

Caro, J Jaime

2016-07-01

Several decision-analytic modeling techniques are in use for pharmacoeconomic analyses. Discretely integrated condition event (DICE) simulation is proposed as a unifying approach that has been deliberately designed to meet the modeling requirements in a straightforward transparent way, without forcing assumptions (e.g., only one transition per cycle) or unnecessary complexity. At the core of DICE are conditions that represent aspects that persist over time. They have levels that can change and many may coexist. Events reflect instantaneous occurrences that may modify some conditions or the timing of other events. The conditions are discretely integrated with events by updating their levels at those times. Profiles of determinant values allow for differences among patients in the predictors of the disease course. Any number of valuations (e.g., utility, cost, willingness-to-pay) of conditions and events can be applied concurrently in a single run. A DICE model is conveniently specified in a series of tables that follow a consistent format and the simulation can be implemented fully in MS Excel, facilitating review and validation. DICE incorporates both state-transition (Markov) models and non-resource-constrained discrete event simulation in a single formulation; it can be executed as a cohort or a microsimulation; and deterministically or stochastically.

Multiple Days of Heat Exposure on Firefighters' Work Performance and Physiology.

Directory of Open Access Journals (Sweden)

Brianna Larsen

Full Text Available This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36 were matched and allocated to either the CON (19°C or HOT (33°C condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc, and skin temperature (Tsk were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants' doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants' work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of

Multiple Days of Heat Exposure on Firefighters’ Work Performance and Physiology

Science.gov (United States)

Larsen, Brianna; Snow, Rod; Vincent, Grace; Tran, Jacqueline; Wolkow, Alexander; Aisbett, Brad

2015-01-01

This study assessed the accumulated effect of ambient heat on the performance of, and physiological and perceptual responses to, intermittent, simulated wildfire fighting tasks over three consecutive days. Firefighters (n = 36) were matched and allocated to either the CON (19°C) or HOT (33°C) condition. They performed three days of intermittent, self-paced simulated firefighting work, interspersed with physiological testing. Task repetitions were counted (and converted to distance or area) to determine work performance. Participants were asked to rate their perceived exertion and thermal sensation after each task. Heart rate, core temperature (Tc), and skin temperature (Tsk) were recorded continuously throughout the simulation. Fluids were consumed ad libitum. Urine volume was measured throughout, and urine specific gravity (USG) analysed, to estimate hydration. All food and fluid consumption was recorded. There was no difference in work output between experimental conditions. However, significant variation in performance responses between individuals was observed. All measures of thermal stress were elevated in the HOT, with core and skin temperature reaching, on average, 0.24 ± 0.08°C and 2.81 ± 0.20°C higher than the CON group. Participants’ doubled their fluid intake in the HOT condition, and this was reflected in the USG scores, where the HOT participants reported significantly lower values. Heart rate was comparable between conditions at nearly all time points, however the peak heart rate reached each circuit was 7 ± 3% higher in the CON trial. Likewise, RPE was slightly elevated in the CON trial for the majority of tasks. Participants’ work output was comparable between the CON and HOT conditions, however the performance change over time varied significantly between individuals. It is likely that the increased fluid replacement in the heat, in concert with frequent rest breaks and task rotation, assisted with the regulation of physiological

Interactions between sleep, stress, and metabolism: From physiological to pathological conditions

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Camila Hirotsu

2015-11-01

Full Text Available Poor sleep quality due to sleep disorders and sleep loss is highly prevalent in the modern society. Underlying mechanisms show that stress is involved in the relationship between sleep and metabolism through hypothalamic–pituitary–adrenal (HPA axis activation. Sleep deprivation and sleep disorders are associated with maladaptive changes in the HPA axis, leading to neuroendocrine dysregulation. Excess of glucocorticoids increase glucose and insulin and decrease adiponectin levels. Thus, this review provides overall view of the relationship between sleep, stress, and metabolism from basic physiology to pathological conditions, highlighting effective treatments for metabolic disturbances.

The use of thermovision camera to observe physiological and pathological conditions of oral cavity mucous membrane

Science.gov (United States)

Dąbrowski, M.; Dulski, R.; Żmuda, S.; Zaborowski, P.; Pogorzelski, C.

2002-06-01

This article presents initial results of investigations of the temperature distribution changes in oral cavity mucous membrane. The investigations aimed to prepare a model of temperature changes existing within mucosal membrane in physiological conditions and to compare those changes with those under pathological conditions. Our investigations were carried out using an infrared imaging system. A representative group of patients was tested.

EXAMINATION OF THE SIMULATED THERMAL CONDITIONS IN A POPULAR PLAYGROUND RELATED TO THE HUMAN REACTIONS AND THE JUDGMENT OF THE AREA DESIGN

Directory of Open Access Journals (Sweden)

L.A. ÉGERHÁZI

2013-03-01

Full Text Available In the field of urban bioclimatology an important and timely research direction today is to examine the thermal conditions of public places. In our study, human thermal comfort analysis was performed in a modern and well-attended children playground located in Szeged (Hungary. The aim of the paper is to reveal the changes in the thermal comfort conditions between two seasons and also the resulting subjective thermal reactions of visitors in this relatively small area. Thermal comfort conditions were quantified by the Physiologically Equivalent Temperature (PET. For typical summer and autumn days of 2011 numerical simulations of thermal comfort conditions in the playground were carried out by means of the urban microclimate model ENVI-met. Spatial distribution of the simulated PET, i.e. thermal stress maps were created in two different times of the selected days in order to characterize the distinct microclimatological conditions appearing in the area. The relationship between the momentary spatial patterns of visitors and the thermal conditions was also under investigation. Additionally, onsite questionnaire survey was implemented which highlights the people’s subjective evaluation related to the design of the playground.

Multiple point statistical simulation using uncertain (soft) conditional data

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Hansen, Thomas Mejer; Vu, Le Thanh; Mosegaard, Klaus; Cordua, Knud Skou

2018-05-01

Geostatistical simulation methods have been used to quantify spatial variability of reservoir models since the 80s. In the last two decades, state of the art simulation methods have changed from being based on covariance-based 2-point statistics to multiple-point statistics (MPS), that allow simulation of more realistic Earth-structures. In addition, increasing amounts of geo-information (geophysical, geological, etc.) from multiple sources are being collected. This pose the problem of integration of these different sources of information, such that decisions related to reservoir models can be taken on an as informed base as possible. In principle, though difficult in practice, this can be achieved using computationally expensive Monte Carlo methods. Here we investigate the use of sequential simulation based MPS simulation methods conditional to uncertain (soft) data, as a computational efficient alternative. First, it is demonstrated that current implementations of sequential simulation based on MPS (e.g. SNESIM, ENESIM and Direct Sampling) do not account properly for uncertain conditional information, due to a combination of using only co-located information, and a random simulation path. Then, we suggest two approaches that better account for the available uncertain information. The first make use of a preferential simulation path, where more informed model parameters are visited preferentially to less informed ones. The second approach involves using non co-located uncertain information. For different types of available data, these approaches are demonstrated to produce simulation results similar to those obtained by the general Monte Carlo based approach. These methods allow MPS simulation to condition properly to uncertain (soft) data, and hence provides a computationally attractive approach for integration of information about a reservoir model.

A suitable boundary condition for bounded plasma simulation without sheath resolution

International Nuclear Information System (INIS)

Parker, S.E.; Procassini, R.J.; Birdsall, C.K.; Cohen, B.I.

1993-01-01

We have developed a technique that allows for a sheath boundary layer without having to resolve the inherently small space and time scales of the sheath region. We refer to this technique as the logical sheath boundary condition. This boundary condition, when incorporated into a direct-implicit particle code, permits large space- and time-scale simulations of bounded systems, which would otherwise be impractical on current supercomputers. The lack of resolution of the collector sheath potential drop obtained from conventional implicit simulations at moderate values of ω pe Δt and Δz/λ De provides the motivation for the development of the logical sheath boundary condition. The algorithm for use of the logical sheath boundary condition in a particle simulation is presented. Results from simulations which use the logical sheath boundary condition are shown to compare reasonably well with those from an analytic theory and simulations in which the sheath is resolved

Using immersive healthcare simulation for physiology education: initial experience in high school, college, and graduate school curricula.

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Oriol, Nancy E; Hayden, Emily M; Joyal-Mowschenson, Julie; Muret-Wagstaff, Sharon; Faux, Russell; Gordon, James A

2011-09-01

In the natural world, learning emerges from the joy of play, experimentation, and inquiry as part of everyday life. However, this kind of informal learning is often difficult to integrate within structured educational curricula. This report describes an educational program that embeds naturalistic learning into formal high school, college, and graduate school science class work. Our experience is based on work with hundreds of high school, college, and graduate students enrolled in traditional science classes in which mannequin simulators were used to teach physiological principles. Specific case scenarios were integrated into the curriculum as problem-solving exercises chosen to accentuate the basic science objectives of the course. This report also highlights the historic and theoretical basis for the use of mannequin simulators as an important physiology education tool and outlines how the authors' experience in healthcare education has been effectively translated to nonclinical student populations. Particular areas of focus include critical-thinking and problem-solving behaviors and student reflections on the impact of the teaching approach.

Physiological Response of Wheat to Chemical Desiccants Used to Simulate Post-Anthesis Drought Stress

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Nasrein Mohamed Kamal

2018-04-01

Full Text Available Post-anthesis drought stress is one of the main constraints on the production of wheat (Triticum aestivum L.. Because field screening for post-anthesis drought tolerance is difficult, effective and validated methods to simulate drought in order to identify sources of tolerance can facilitate screening of breeding materials. Chemical desiccants are widely used to simulate post-anthesis drought stress. We aimed to identify physiological traits that respond to desiccants as they do to drought. We examined the responses of ‘Norin 61’ to six treatments in a greenhouse: irrigated control, drought after anthesis, and 2% or 4% potassium chlorate (KClO3 at anthesis (A or grain filling (GF. We measured δ13C in leaves, aboveground fresh biomass, stomatal conductance, chlorophyll content, harvest index, and grain yield. Both 2% and 4% KClO3 at both A and GF simulated the effect of drought stress. Selection of drought-tolerant genotypes can be aided by chlorophyll content and δ13C measurement of leaves when 2% or 4% KClO3 is used to simulate drought.

Interoception: the sense of the physiological condition of the body.

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Craig, A D

2003-08-01

Converging evidence indicates that primates have a distinct cortical image of homeostatic afferent activity that reflects all aspects of the physiological condition of all tissues of the body. This interoceptive system, associated with autonomic motor control, is distinct from the exteroceptive system (cutaneous mechanoreception and proprioception) that guides somatic motor activity. The primary interoceptive representation in the dorsal posterior insula engenders distinct highly resolved feelings from the body that include pain, temperature, itch, sensual touch, muscular and visceral sensations, vasomotor activity, hunger, thirst, and 'air hunger'. In humans, a meta-representation of the primary interoceptive activity is engendered in the right anterior insula, which seems to provide the basis for the subjective image of the material self as a feeling (sentient) entity, that is, emotional awareness.

Exact simulation of conditioned Wright-Fisher models.

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Zhao, Lei; Lascoux, Martin; Waxman, David

2014-12-21

Forward and backward simulations play an increasing role in population genetics, in particular when inferring the relative importance of evolutionary forces. It is therefore important to develop fast and accurate simulation methods for general population genetics models. Here we present an exact simulation method that generates trajectories of an allele׳s frequency in a finite population, as described by a general Wright-Fisher model. The method generates conditioned trajectories that start from a known frequency at a known time, and which achieve a specific final frequency at a known final time. The simulation method applies irrespective of the smallness of the probability of the transition between the initial and final states, because it is not based on rejection of trajectories. We illustrate the method on several different populations where a Wright-Fisher model (or related) applies, namely (i) a locus with 2 alleles, that is subject to selection and mutation; (ii) a locus with 3 alleles, that is subject to selection; (iii) a locus in a metapopulation consisting of two subpopulations of finite size, that are subject to selection and migration. The simulation method allows the generation of conditioned trajectories that can be used for the purposes of visualisation, the estimation of summary statistics, and the development/testing of new inferential methods. The simulated trajectories provide a very simple approach to estimating quantities that cannot easily be expressed in terms of the transition matrix, and can be applied to finite Markov chains other than the Wright-Fisher model. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of acclimation on poststocking dispersal and physiological condition of age-1 pallid sturgeon

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Oldenburg, E.W.; Guy, C.S.; Cureton, E.S.; Webb, M.A.H.; Gardner, W.M.

2011-01-01

The objective of this study was to evaluate the effects of acclimation to flow and site-specific physicochemical water conditions on poststocking dispersal and physiological condition of age-1 hatchery-reared pallid sturgeon. Fish from three acclimation treatments were radio-tagged, released at two locations (Missouri River and Marias River), and monitored using passive telemetry stations. Marias treatment was acclimated to flow and site-specific physicochemical conditions, Bozeman treatment was acclimated to flow only, and controls had no acclimation (reared under traditional conservation propagation protocol). During both years, fish released in the Missouri River dispersed less than fish released in the Marias River. In 2005, Marias treatment dispersed less and nearly twice as many fish remained in the Missouri River reach as compared to control fish. In 2006, pallid sturgeon dispersed similarly among treatments and the number of fish remaining in the Missouri River reach was similar among all treatments. Differences in poststocking dispersal between years were related to fin curl which was present in all fish in 2005 and only 26% in 2006. Pallid sturgeon from all treatments in both years had a greater affinity for the lower reaches of the Missouri River than the upper reaches. Thus, release site influenced poststocking dispersal more than acclimation treatment. No difference was observed in relative growth rate among treatments. However, acclimation to flow (i.e., exercise conditioning) prevented fat accumulation from rupturing hepatocytes. Acclimation conditions used in this study did not benefit pallid sturgeon unless physiological maladies were present. Overriding all treatment effects was stocking location; thus, natural resource agencies need to consider stocking location carefully to reduce poststocking dispersal. ?? 2011 Blackwell Verlag, Berlin.

Semi-physiologic model validation and bioequivalence trials simulation to select the best analyte for acetylsalicylic acid.

Science.gov (United States)

Cuesta-Gragera, Ana; Navarro-Fontestad, Carmen; Mangas-Sanjuan, Victor; González-Álvarez, Isabel; García-Arieta, Alfredo; Trocóniz, Iñaki F; Casabó, Vicente G; Bermejo, Marival

2015-07-10

The objective of this paper is to apply a previously developed semi-physiologic pharmacokinetic model implemented in NONMEM to simulate bioequivalence trials (BE) of acetyl salicylic acid (ASA) in order to validate the model performance against ASA human experimental data. ASA is a drug with first-pass hepatic and intestinal metabolism following Michaelis-Menten kinetics that leads to the formation of two main metabolites in two generations (first and second generation metabolites). The first aim was to adapt the semi-physiological model for ASA in NOMMEN using ASA pharmacokinetic parameters from literature, showing its sequential metabolism. The second aim was to validate this model by comparing the results obtained in NONMEM simulations with published experimental data at a dose of 1000 mg. The validated model was used to simulate bioequivalence trials at 3 dose schemes (100, 1000 and 3000 mg) and with 6 test formulations with decreasing in vivo dissolution rate constants versus the reference formulation (kD 8-0.25 h (-1)). Finally, the third aim was to determine which analyte (parent drug, first generation or second generation metabolite) was more sensitive to changes in formulation performance. The validation results showed that the concentration-time curves obtained with the simulations reproduced closely the published experimental data, confirming model performance. The parent drug (ASA) was the analyte that showed to be more sensitive to the decrease in pharmaceutical quality, with the highest decrease in Cmax and AUC ratio between test and reference formulations. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation by fluorescence resonance energy transfer of the stability of nonviral gene delivery vectors under physiological conditions.

Science.gov (United States)

Itaka, Keiji; Harada, Atsushi; Nakamura, Kozo; Kawaguchi, Hiroshi; Kataoka, Kazunori

2002-01-01

The stability in physiological medium of polyplex- and lipoplex-type nonviral gene vectors was evaluated by detecting the conformational change of complexed plasmid DNA (pDNA) labeled simultaneously with fluorescein (energy donor) and X-rhodamine (energy acceptor) through fluorescence resonance energy transfer (FRET). Upon mixing with cationic components, such as LipofectAMINE, poly(L-lysine), and poly(ethylene glycol)-poly(L-lysine) block copolymer (PEG-PLys), the fluorescence spectrum of doubly labeled pDNA underwent a drastic change due to the occurrence of FRET between the donor-acceptor pair on pDNA taking a globular conformation (condensed state) through complexation. The measurement was carried out also in the presence of 20% serum, under which conditions FRET from condensed pDNA was clearly monitored without interference from coexisting components in the medium, allowing evaluation of the condensed state of pDNA in nonviral gene vectors under physiological conditions. Serum addition immediately induced a sharp decrease in FRET for the LipofectAMINE/pDNA (lipoplex) system, which was consistent with the sharp decrease in the transfection efficiency of the lipoplex system in serum-containing medium. In contrast, the PEG-PLys/pDNA polyplex (polyion complex micelle) system maintained appreciable transfection efficiency even in serum-containing medium, and FRET efficiency remained constant for up to 12 h, indicating the high stability of the polyion complex micelle under physiological conditions.

Intraspecific variation in physiological condition of reef-building corals associated with differential levels of chronic disturbance.

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Chiara Pisapia

Full Text Available Even in the absence of major disturbances (e.g., cyclones, bleaching, corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis, subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, p<0.02, B =  -121255, p = 0.03 and total lipid content increased (r2 = 14, df = 5,42, p = 0.01, B = 0.9, p = 0.01 with increasing distance from exposed crests. Moreover, zooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, p<0.02, B =  -7386077, p = 0.01. Conversely, P. damicornis exhibited very limited intraspecific variation in physiological condition, despite marked differences in levels of partial mortality. This is the first study to relate intraspecific variation in the condition of corals to localized differences in chronic disturbance regimes. The next step is to ascertain whether these differences have further ramifications for susceptibility to periodic acute disturbances, such as climate-induced coral bleaching.

Extremophiles survival to simulated space conditions: an astrobiology model study.

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Mastascusa, V; Romano, I; Di Donato, P; Poli, A; Della Corte, V; Rotundi, A; Bussoletti, E; Quarto, M; Pugliese, M; Nicolaus, B

2014-09-01

In this work we investigated the ability of four extremophilic bacteria from Archaea and Bacteria domains to resist to space environment by exposing them to extreme conditions of temperature, UV radiation, desiccation coupled to low pressure generated in a Mars' conditions simulator. All the investigated extremophilic strains (namely Sulfolobus solfataricus, Haloterrigena hispanica, Thermotoga neapolitana and Geobacillus thermantarcticus) showed a good resistance to the simulation of the temperature variation in the space; on the other hand irradiation with UV at 254 nm affected only slightly the growth of H. hispanica, G. thermantarcticus and S. solfataricus; finally exposition to Mars simulated condition showed that H. hispanica and G. thermantarcticus were resistant to desiccation and low pressure.

Selecting boundary conditions in physiological strain analysis of the femur: Balanced loads, inertia relief method and follower load.

Science.gov (United States)

Heyland, Mark; Trepczynski, Adam; Duda, Georg N; Zehn, Manfred; Schaser, Klaus-Dieter; Märdian, Sven

2015-12-01

Selection of boundary constraints may influence amount and distribution of loads. The purpose of this study is to analyze the potential of inertia relief and follower load to maintain the effects of musculoskeletal loads even under large deflections in patient specific finite element models of intact or fractured bone compared to empiric boundary constraints which have been shown to lead to physiological displacements and surface strains. The goal is to elucidate the use of boundary conditions in strain analyses of bones. Finite element models of the intact femur and a model of clinically relevant fracture stabilization by locking plate fixation were analyzed with normal walking loading conditions for different boundary conditions, specifically re-balanced loading, inertia relief and follower load. Peak principal cortex surface strains for different boundary conditions are consistent (maximum deviation 13.7%) except for inertia relief without force balancing (maximum deviation 108.4%). Influence of follower load on displacements increases with higher deflection in fracture model (from 3% to 7% for force balanced model). For load balanced models, follower load had only minor influence, though the effect increases strongly with higher deflection. Conventional constraints of fixed nodes in space should be carefully reconsidered because their type and position are challenging to justify and for their potential to introduce relevant non-physiological reaction forces. Inertia relief provides an alternative method which yields physiological strain results. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Simulation of forest growth, applied to douglas fir stands in the Netherlands

NARCIS (Netherlands)

Mohren, G.M.J.

1987-01-01

Forest growth in relation to weather and soils is studied using a physiological simulation model. Growth potential depends on physiological characteristics of the plant species in combination with ambient weather conditions (mainly temperature and incoming radiation). For a given site, growth may be

Local air gap thickness and contact area models for realistic simulation of human thermo-physiological response

Science.gov (United States)

Psikuta, Agnes; Mert, Emel; Annaheim, Simon; Rossi, René M.

2018-02-01

To evaluate the quality of new energy-saving and performance-supporting building and urban settings, the thermal sensation and comfort models are often used. The accuracy of these models is related to accurate prediction of the human thermo-physiological response that, in turn, is highly sensitive to the local effect of clothing. This study aimed at the development of an empirical regression model of the air gap thickness and the contact area in clothing to accurately simulate human thermal and perceptual response. The statistical model predicted reliably both parameters for 14 body regions based on the clothing ease allowances. The effect of the standard error in air gap prediction on the thermo-physiological response was lower than the differences between healthy humans. It was demonstrated that currently used assumptions and methods for determination of the air gap thickness can produce a substantial error for all global, mean, and local physiological parameters, and hence, lead to false estimation of the resultant physiological state of the human body, thermal sensation, and comfort. Thus, this model may help researchers to strive for improvement of human thermal comfort, health, productivity, safety, and overall sense of well-being with simultaneous reduction of energy consumption and costs in built environment.

Electrochemical characterization of AISI 316L stainless steel in contact with simulated body fluid under infection conditions.

Science.gov (United States)

López, Danián Alejandro; Durán, Alicia; Ceré, Silvia Marcela

2008-05-01

Titanium and cobalt alloys, as well as some stainless steels, are among the most frequently used materials in orthopaedic surgery. In industrialized countries, stainless steel devices are used only for temporary implants due to their lower corrosion resistance in physiologic media when compared to other alloys. However, due to economical reasons, the use of stainless steel alloys for permanent implants is very common in developing countries. The implantation of foreign bodies is sometimes necessary in the modern medical practice. However, the complex interactions between the host and the can implant weaken the local immune system, increasing the risk of infections. Therefore, it is necessary to further study these materials as well as the characteristics of the superficial film formed in physiologic media in infection conditions in order to control their potential toxicity due to the release of metallic ions in the human body. This work presents a study of the superficial composition and the corrosion resistance of AISI 316L stainless steel and the influence of its main alloying elements when they are exposed to an acidic solution that simulates the change of pH that occurs when an infection develops. Aerated simulated body fluid (SBF) was employed as working solution at 37 degrees C. The pH was adjusted to 7.25 and 4 in order to reproduce normal body and disease state respectively. Corrosion resistance was measured by means of electrochemical impedance spectroscopy (EIS) and anodic polarization curves.

The Effects of Exercising in Different Natural Environments on Psycho-Physiological Outcomes in Post-Menopausal Women: A Simulation Study

Directory of Open Access Journals (Sweden)

Mathew P. White

2015-09-01

Full Text Available The current study examined potential psycho-physiological benefits from exercising in simulated natural environments among a sample of post-menopausal women using a laboratory based protocol. Participants cycled on a stationary exercise bike for 15 min while facing either a blank wall (Control or while watching one of three videos: Urban (Grey, Countryside (Green, Coast (Blue. Blood pressure, heart rate and affective responses were measured pre-post. Heart rate, affect, perceived exertion and time perception were also measured at 5, 10 and 15 min during exercise. Experience evaluation was measured at the end. Replicating most earlier findings, affective, but not physiological, outcomes were more positive for exercise in the simulated Green and, for the first time, Blue environment, compared to Control. Moreover, only the simulated Blue environment was associated with shorter perceived exercise duration than Control and participants were most willing to repeat exercise in the Blue setting. The current research extended earlier work by exploring the effects of “blue exercise” and by using a demographic with relatively low average levels of physical activity. That this sample of postmenopausal women were most willing to repeat a bout of exercise in a simulated Blue environment may be important for physical activity promotion in this cohort.

The Effects of Exercising in Different Natural Environments on Psycho-Physiological Outcomes in Post-Menopausal Women: A Simulation Study

Science.gov (United States)

White, Mathew P.; Pahl, Sabine; Ashbullby, Katherine J.; Burton, Francesca; Depledge, Michael H.

2015-01-01

The current study examined potential psycho-physiological benefits from exercising in simulated natural environments among a sample of post-menopausal women using a laboratory based protocol. Participants cycled on a stationary exercise bike for 15 min while facing either a blank wall (Control) or while watching one of three videos: Urban (Grey), Countryside (Green), Coast (Blue). Blood pressure, heart rate and affective responses were measured pre-post. Heart rate, affect, perceived exertion and time perception were also measured at 5, 10 and 15 min during exercise. Experience evaluation was measured at the end. Replicating most earlier findings, affective, but not physiological, outcomes were more positive for exercise in the simulated Green and, for the first time, Blue environment, compared to Control. Moreover, only the simulated Blue environment was associated with shorter perceived exercise duration than Control and participants were most willing to repeat exercise in the Blue setting. The current research extended earlier work by exploring the effects of “blue exercise” and by using a demographic with relatively low average levels of physical activity. That this sample of postmenopausal women were most willing to repeat a bout of exercise in a simulated Blue environment may be important for physical activity promotion in this cohort. PMID:26404351

Human experimental anxiety: actual public speaking induces more intense physiological responses than simulated public speaking.

Science.gov (United States)

Zuardi, Antonio Waldo; Crippa, José Alexandre de Souza; Hallak, Jaime Eduardo Cecílio; Gorayeb, Ricardo

2013-01-01

a) To perform a systematic and meta-analytic review to verify whether the Simulated Public Speaking Task (SPST) leads to a greater increase in self-rated anxiety than in physiological correlates of anxiety; and b) to compare the results obtained with the SPST with an actual public speaking task involving healthy volunteers. a) The PubMed and ISI Web of Knowledge databases were searched for studies involving the SPST prior to 2012. Eleven publications were eligible and provided data from 143 healthy volunteers for meta-analysis; b) 48 university students without somatic or psychiatric disorders were divided into three experimental groups of 16 subjects to undergo one of the following: SPST, real-world public speaking task (real-world), and control situation (control). The meta-analysis showed that the SPST induced a significant increase in the Visual Analogue Mood Scale (VAMS) anxiety factor, but no significant increases in systolic blood pressure or heart rate. The empirical study showed that the real-world public speaking task increased heart rate, systolic blood pressure and diastolic blood pressure significantly more than the control and SPST conditions. These results suggest that real public speaking might be better than SPST in inducing experimental anxiety.

BrainSignals Revisited: Simplifying a Computational Model of Cerebral Physiology.

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Matthew Caldwell

Full Text Available Multimodal monitoring of brain state is important both for the investigation of healthy cerebral physiology and to inform clinical decision making in conditions of injury and disease. Near-infrared spectroscopy is an instrument modality that allows non-invasive measurement of several physiological variables of clinical interest, notably haemoglobin oxygenation and the redox state of the metabolic enzyme cytochrome c oxidase. Interpreting such measurements requires the integration of multiple signals from different sources to try to understand the physiological states giving rise to them. We have previously published several computational models to assist with such interpretation. Like many models in the realm of Systems Biology, these are complex and dependent on many parameters that can be difficult or impossible to measure precisely. Taking one such model, BrainSignals, as a starting point, we have developed several variant models in which specific regions of complexity are substituted with much simpler linear approximations. We demonstrate that model behaviour can be maintained whilst achieving a significant reduction in complexity, provided that the linearity assumptions hold. The simplified models have been tested for applicability with simulated data and experimental data from healthy adults undergoing a hypercapnia challenge, but relevance to different physiological and pathophysiological conditions will require specific testing. In conditions where the simplified models are applicable, their greater efficiency has potential to allow their use at the bedside to help interpret clinical data in near real-time.

The wettability modification of bio-grade stainless steel in contact with simulated physiological liquids by the means of laser irradiation

International Nuclear Information System (INIS)

Hao, L.; Lawrence, J.; Li, L.

2005-01-01

Early surface events that occur rapidly upon implantation of a biomaterial into biological fluids determine the subsequent response. These involve wetting by physiological liquids followed by adsorption of proteins and cells to the biomaterials surface. A CO 2 laser and high power diode laser (HPDL) were used to modify the surface properties of the material and thus manipulate the wettability of the material and its interaction with physiological liquids. The contact angles, θ, of selected test liquids including simulated physiological liquids shows that the wettability of the stainless steel improved after CO 2 and HPDL treatment. The determined adhesion work of stainless steel towards stimulated physiological fluid enhanced after laser treatment, implying better interaction with the biological liquids. It is demonstrated that the laser could be a novel and controllable technique for enhancing the biocompatibility of bio-grade stainless steel

Assessment of bioclimatic comfort conditions based on Physiologically Equivalent Temperature (PET) using the RayMan Model in Iran

Science.gov (United States)

Daneshvar, Mohammad Reza Mansouri; Bagherzadeh, Ali; Tavousi, Taghi

2013-03-01

In this study thermal comfort conditions are analyzed to determine possible thermal perceptions during different months in Iran through the Physiologically Equivalent Temperature (PET). The monthly PET values produced using the RayMan Model ranged from -7.6°C to 46.8°C. Over the winter months the thermal comfort condition (18-23°C) were concentrated in southern coastal areas along the Persian Gulf and Oman Sea. Most of the country experienced comfort conditions during the spring months, in particular in April, while during the summer months of July and August no thermal comfort conditions were observed. In November coastal areas of the Caspian Sea had the same physiological stress level of thermal comfort as April. The map produced showing mean annual PET conditions demonstrated the greatest spatial distribution of comfortable levels in the elevation range from 1000 to 2000 meter a.s.l., with annual temperatures of 12-20°C and annual precipitation of under 200 mm. The statistical relationship between PET conditions and each controlling parameter revealed a significant correlation in areas above 2000 meter, annual temperature over 20°C and annual precipitation of 200-400 mm with a correlation coefficient ( R 2) of 0.91, 0.97 and 0.96, respectively.

Physico-chemical changes of ZnO nanoparticles with different size and surface chemistry under physiological pH conditions.

Science.gov (United States)

Gwak, Gyeong-Hyeon; Lee, Won-Jae; Paek, Seung-Min; Oh, Jae-Min

2015-03-01

We studied the physico-chemical properties of ZnO nanoparticles under physiological pH conditions (gastric, intestinal and plasma) as functions of their size (20 and 70 nm) and surface chemistry (pristine, L-serine, or citrate coating). ZnO nanoparticles were dispersed in phosphate buffered saline under physiological pH conditions and aliquots were collected at specific time points (0.5, 1, 4, 10 and 24 h) for further characterization. The pH values of the aqueous ZnO colloids at each condition were in the neutral to slightly basic range and showed different patterns depending on the original size and surface chemistry of the ZnO nanoparticles. The gastric pH condition was found to significantly dissolve ZnO nanoparticles up to 18-30 wt%, while the intestinal or plasma pH conditions resulted in much lower dissolution amounts than expected. Based on the X-ray diffraction patterns and X-ray absorption spectra, we identified partial phase transition of the ZnO nanoparticles from wurtzite to Zn(OH)2 under the intestinal and plasma pH conditions. Using scanning electron microscopy, we verified that the overall particle size and morphology of all ZnO nanoparticles were maintained regardless of the pH. Copyright © 2015 Elsevier B.V. All rights reserved.

Five Conditions Commonly Used to Down-regulate Tor Complex 1 Generate Different Physiological Situations Exhibiting Distinct Requirements and Outcomes*

Science.gov (United States)

Tate, Jennifer J.; Cooper, Terrance G.

2013-01-01

Five different physiological conditions have been used interchangeably to establish the sequence of molecular events needed to achieve nitrogen-responsive down-regulation of TorC1 and its subsequent regulation of downstream reporters: nitrogen starvation, methionine sulfoximine (Msx) addition, nitrogen limitation, rapamycin addition, and leucine starvation. Therefore, we tested a specific underlying assumption upon which the interpretation of data generated by these five experimental perturbations is premised. It is that they generate physiologically equivalent outcomes with respect to TorC1, i.e. its down-regulation as reflected by TorC1 reporter responses. We tested this assumption by performing head-to-head comparisons of the requirements for each condition to achieve a common outcome for a downstream proxy of TorC1 inactivation, nuclear Gln3 localization. We demonstrate that the five conditions for down-regulating TorC1 do not elicit physiologically equivalent outcomes. Four of the methods exhibit hierarchical Sit4 and PP2A phosphatase requirements to elicit nuclear Gln3-Myc13 localization. Rapamycin treatment required Sit4 and PP2A. Nitrogen limitation and short-term nitrogen starvation required only Sit4. G1 arrest-correlated, long-term nitrogen starvation and Msx treatment required neither PP2A nor Sit4. Starving cells of leucine or treating them with leucyl-tRNA synthetase inhibitors did not elicit nuclear Gln3-Myc13 localization. These data indicate that the five commonly used nitrogen-related conditions of down-regulating TorC1 are not physiologically equivalent and minimally involve partially differing regulatory mechanisms. Further, identical requirements for Msx treatment and long-term nitrogen starvation raise the possibility that their effects are achieved through a common regulatory pathway with glutamine, a glutamate or glutamine metabolite level as the sensed metabolic signal. PMID:23935103

Microwave tomography of extremities: 1. Dedicated 2D system and physiological signatures

International Nuclear Information System (INIS)

Semenov, Serguei; Nair, Bindu; Kellam, James; Williams, Thomas; Quinn, Michael; Sizov, Yuri; Nazarov, Alexei; Pavlovsky, Andrey; Posukh, Vitaly

2011-01-01

Microwave tomography (MWT) is a novel imaging modality which might be applicable for non-invasive assessment of functional and pathological conditions of biological tissues. Imaging of the soft tissue of extremities is one of its potential applications. The feasibility of this technology for such applications was demonstrated earlier. This is the first of two companion papers focused on an application of MWT for imaging of the extremity's soft tissues. The goal of this study is to assess the technical performance of the developed 2D MWT system dedicated for imaging of functional and pathological conditions of the extremity's soft tissues. Specifically, the system's performance was tested by its ability to detect signals associated with physiological activity and soft tissue interventions (circulatory related changes, blood flow reduction and a simulated compartmental syndrome)-the so-called physiological signatures. The developed 2D MWT system dedicated to the imaging of animal extremities demonstrates good technical performance allowing for stable and predictable data acquisition with reasonable agreement between the experimentally measured electromagnetic (EM) field and the simulated EM field within a measurement domain. Using the system, we were able to obtain physiological signatures associated with systolic versus diastolic phases of circulation in an animal extremity, reperfusion versus occlusion phases of the blood supply to the animal's extremity and a compartment syndrome. The imaging results are presented and discussed in the second companion paper.

Dynamic simulation of variable capacity refrigeration systems under abnormal conditions

International Nuclear Information System (INIS)

Liang Nan; Shao Shuangquan; Tian Changqing; Yan Yuying

2010-01-01

There are often abnormal working conditions at evaporator outlet of a refrigeration system, such as two-phase state in transient process, and it is essential to investigate such transient behaviours for system design and control strategy. In this paper, a dynamic lumped parameter model is developed to simulate the transient behaviours of refrigeration system with variable capacity in both normal and abnormal working conditions. The appropriate discriminant method is adopted to switch the normal and abnormal conditions smoothly and to eliminate the simulated data oscillation. In order to verify the dynamic model, we built a test system with variable frequency compressor, water-cooling condenser, evaporator and electronic expansion valve. Calculated values from the mathematical model show reasonable agreement with the experimental data. The simulation results show that the transient behaviours of the variable capacity refrigeration system in the abnormal working conditions can be calculated reliably with the dynamic model when the compressor rotary speed or the opening of electronic expansion valve changes abruptly.

The relationships between environmental and physiological heat stress indices in Muslim women under the controlled thermal conditions

Directory of Open Access Journals (Sweden)

Peymaneh Habibi

2015-01-01

Full Text Available Aims: The aim of this study was to evaluate the relationship between environmental and physiological heat stress indices based on heart rate (HR, oral temperature for the estimation of heat strain, in veiled women in hot-dry condition in the climate chamber. Materials and Methods: The experimental study was carried out on 36 healthy Muslim women in hot-dry climatic conditions (wet bulb globe temperature (WBGT = 22-32°C in low workload for 2 h. The HR, oral temperature and WBGT index were measured. The obtained data were analyzed using descriptive statistics and Pearson correlation tests. Results: The results of the Pearson test indicated that physiological strain index was a high correlation (r = 0.975 with WBGT index (P < 0.05. Also, there was a good correlation among WBGT and HR (r = 0.779 and oral temperature (r = 0.981. Conclusion: The findings of this study illustrated that there is a good correlation between environmental and physiological heat stress indices in veiled women with Islamic clothing at the low workload over the action limit (WBGT = 31°C. So that it can be concluded that the WBGT 22-32°C is a good indicator of the heat strain in veiled women with Islamic clothing.

Ecto-ATPase inhibition: ATP and adenosine release under physiological and ischemic in vivo conditions in the rat striatum.

Science.gov (United States)

Melani, Alessia; Corti, Francesca; Stephan, Holger; Müller, Christa E; Donati, Chiara; Bruni, Paola; Vannucchi, Maria Giuliana; Pedata, Felicita

2012-01-01

In the central nervous system (CNS) ATP and adenosine act as transmitters and neuromodulators on their own receptors but it is still unknown which part of extracellular adenosine derives per se from cells and which part is formed from the hydrolysis of released ATP. In this study extracellular concentrations of adenosine and ATP from the rat striatum were estimated by the microdialysis technique under in vivo physiological conditions and after focal ischemia induced by medial cerebral artery occlusion. Under physiological conditions, adenosine and ATP concentrations were in the range of 130 nmol/L and 40 nmol/L, respectively. In the presence of the novel ecto-ATPase inhibitor, PV4 (100 nmol/L), the extracellular concentration of ATP increased 12-fold to ~360 nmol/L but the adenosine concentration was not altered. This demonstrates that, under physiological conditions, adenosine is not a product of extracellular ATP. In the first 4h after ischemia, adenosine increased to ~690 nmol/L and ATP to ~50 nmol/L. In the presence of PV4 the extracellular concentration of ATP was in the range of 450 nmol/L and a significant decrease in extracellular adenosine (to ~270 nmol/L) was measured. The contribution of extracellular ATP to extracellular adenosine was maximal in the first 20 min after ischemia onset. Furthermore we demonstrated, by immunoelectron microscopy, the presence of the concentrative nucleoside transporter CNT2 on plasma and vesicle membranes isolated from the rat striatum. These results are in favor that adenosine is transported in vesicles and is released in an excitation-secretion manner under in vivo physiological conditions. Early after ischemia, extracellular ATP is hydrolyzed by ecto-nucleotidases which significantly contribute to the increase in extracellular adenosine. To establish the contribution of extracellular ATP to adenosine might constitute the basis for devising a correct putative purinergic strategy aimed at protection from ischemic damage

Investigating the Effects of Simulated Space conditions on Novel Extremely Halophilic Archaea: Halovarius Luteus gen. nov., sp. nov.

Science.gov (United States)

Feshangsaz, Niloofar; Van Loon, ing.. Jack J. W. A.; Nazmi, Kamran; Semsarha, Farid

2016-07-01

Studying halophiles from different environments of Earth provide new insights into our search for life in the universe. Haloarchaea show some unique characteristics and physiological adaptations like acidic proteins against harsh environments such as natural brine with salt concentration approaching saturation (5 M) and regions with low active water. These properties make haloarchaea interesting candidate for astrobiological studies. Halovarius luteus gen. nov., sp. nov. a novel extremely halophilic archaeon from Urmia salt lake, in Iran has been chosen to explore its resistance against a series of extreme conditions. The aim of this study is to assess the resistance of strain DA50T under the effects of simulated space conditions like simulated microgravity, hypergravity, and desiccation. In this paper we will discuss the results of these studies where we specifically focus on changes in carotenoid pigments production and whole cell proteome. This is the first report of very novel Iranian archaea in response to extreme space conditions. The pigments were extracted by acetone and methanol. Pigments were analyzed by scanning the absorbance spectrum in the UV-VIS spectrophotometer. And they were separated by TLC. Whole protein from cell lysate supernatant was extracted after lysis with Bacterial Protein Extraction Reagent and fractionated by RP-HPLC using C18 column. Proteome analyzed by electrophoresis (SDS-PAGE), and MALDI-TOF. Carotenoid pigments are formed under different extreme conditions such as dry environment and gravitational changes. Also the protein composition exhibits alterations after exposure to the same conditions. Our conclusion is that pigments and proteins formation depend on the growth circumstances. Halophiles use this as an adaptation to survive under different environmental conditions.

Low-dose ionizing radiation limitations to seed germination: Results from a model linking physiological characteristics and developmental-dynamics simulation strategy.

Science.gov (United States)

Liu, Hui; Hu, Dawei; Dong, Chen; Fu, Yuming; Liu, Guanghui; Qin, Youcai; Sun, Yi; Liu, Dianlei; Li, Lei; Liu, Hong

2017-08-01

There is much uncertainty about the risks of seed germination after repeated or protracted environmental low-dose ionizing radiation exposure. The purpose of this study is to explore the influence mechanism of low-dose ionizing radiation on wheat seed germination using a model linking physiological characteristics and developmental-dynamics simulation. A low-dose ionizing radiation environment simulator was built to investigate wheat (Triticum aestivum L.) seeds germination process and then a kinetic model expressing the relationship between wheat seed germination dynamics and low-dose ionizing radiation intensity variations was developed by experimental data, plant physiology, relevant hypotheses and system dynamics, and sufficiently validated and accredited by computer simulation. Germination percentages were showing no differences in response to different dose rates. However, root and shoot lengths were reduced significantly. Plasma governing equations were set up and the finite element analysis demonstrated H 2 O, CO 2 , O 2 as well as the seed physiological responses to the low-dose ionizing radiation. The kinetic model was highly valid, and simultaneously the related influence mechanism of low-dose ionizing radiation on wheat seed germination proposed in the modeling process was also adequately verified. Collectively these data demonstrate that low-dose ionizing radiation has an important effect on absorbing water, consuming O 2 and releasing CO 2 , which means the risk for embryo and endosperm development was higher. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physiological and behavioral responses to an exposure of pitch illusion in the simulator.

Science.gov (United States)

Cheung, Bob; Hofer, Kevin; Heskin, Raquel; Smith, Andrew

2004-08-01

It has been suggested that a pilot's physiological and behavioral responses during disorientation can provide a real-time model of pilot state in order to optimize performance. We investigated whether there were consistent behavioral or physiological "markers" that can be monitored during a single episode of disorientation. An Integrated Physiological Trainer with a closed loop interactive aircraft control and point of gaze/eye-tracking device was employed. There were 16 subjects proficient in maintaining straight and level flight and with procedures in changing attitude who were exposed to yaw rotation and a brief head roll to 35 +/- 2 degrees. On return to upright head position, subjects were required to initiate either an ascent or descent to a prescribed attitude. BP, HR, skin conductance, eye movements, and point of gaze were monitored throughout the onset, duration, and immediately after the disorientation insult. Simultaneously, airspeed and power settings were recorded. Compared with the control condition, a significant increase (p decrement was reflected by a significant delay in setting power for attitude change and deviation in maintaining airspeed (p decrement is consistent with our previous findings. Further study is required to determine whether these findings can be extrapolated to repeated exposures and to other disorientation scenarios.

Synchronized mammalian cell culture: part I--a physical strategy for synchronized cultivation under physiological conditions.

Science.gov (United States)

Barradas, Oscar Platas; Jandt, Uwe; Becker, Max; Bahnemann, Janina; Pörtner, Ralf; Zeng, An-Ping

2015-01-01

Conventional analysis and optimization procedures of mammalian cell culture processes mostly treat the culture as a homogeneous population. Hence, the focus is on cell physiology and metabolism, cell line development, and process control strategy. Impact on cultivations caused by potential variations in cellular properties between different subpopulations, however, has not yet been evaluated systematically. One main cause for the formation of such subpopulations is the progress of all cells through the cell cycle. The interaction of potential cell cycle specific variations in the cell behavior with large-scale process conditions can be optimally determined by means of (partially) synchronized cultivations, with subsequent population resolved model analysis. Therefore, it is desirable to synchronize a culture with minimal perturbation, which is possible with different yield and quality using physical selection methods, but not with frequently used chemical or whole-culture methods. Conventional nonsynchronizing methods with subsequent cell-specific, for example, flow cytometric analysis, can only resolve cell-limited effects of the cell cycle. In this work, we demonstrate countercurrent-flow centrifugal elutriation as a useful physical method to enrich mammalian cell populations within different phases of a cell cycle, which can be further cultivated for synchronized growth in bioreactors under physiological conditions. The presented combined approach contrasts with other physical selection methods especially with respect to the achievable yield, which makes it suitable for bioreactor scale cultivations. As shown with two industrial cell lines (CHO-K1 and human AGE1.HN), synchronous inocula can be obtained with overall synchrony degrees of up to 82% in the G1 phase, 53% in the S phase and 60% in the G2/M phase, with enrichment factors (Ysync) of 1.71, 1.79, and 4.24 respectively. Cells are able to grow with synchrony in bioreactors over several cell cycles. This

Intraspecific variation in physiological condition of reef-building corals associated with differential levels of chronic disturbance.

Science.gov (United States)

Pisapia, Chiara; Anderson, Kristen; Pratchett, Morgan S

2014-01-01

Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density) through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis), subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, pzooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, pclimate-induced coral bleaching.

The role of performing life support courses in rural areas in improving pre-hospital physiologic condition of patients with penetrating injuries

International Nuclear Information System (INIS)

Naffisi, N.; Mohebbi, H.A.; Moharamzadeh, Y.

2008-01-01

To evaluate the impact of animal model based medical training courses for village healthcare workers on prehospital physiologic condition and prognosis of patients with penetrating injuries. Seventy-six village healthcare workers were trained and equipped to deliver in-field medical first cares. First group (226 patients) consisted of those who received this cares by the trained group and second group (245 patients) were those who received no in-field cares and were transported directly to the trauma center in provincial capital, Ilam. Physiologic Severity Score (PSS) was calculated to determine the physiologic condition of patients in both groups. Results: The most prevalent cause of trauma in both groups was car accidents (61.6%). Controlling of hemorrhage was the most frequent provided initial medical care (40.6%). A significant improvement regarding the PSS score was observed in the first group of patients compared to the second group (7.505 vs. 6.799, 95% CI for difference: 0.3 to 0.9). The mortality rates of the first and second group of patients were 3% and 7.3%, respectively (p=0.051). Performing life support courses in rural areas of low-income countries where there is no pre-hospital triage and emergency medical system and provision of classic resuscitative measures are limited, has a significant impact on improvement of pre-hospital physiologic condition and prognosis of patients with penetrating injuries. (author)

Role of Boundary Conditions in Monte Carlo Simulation of MEMS Devices

Science.gov (United States)

Nance, Robert P.; Hash, David B.; Hassan, H. A.

1997-01-01

A study is made of the issues surrounding prediction of microchannel flows using the direct simulation Monte Carlo method. This investigation includes the introduction and use of new inflow and outflow boundary conditions suitable for subsonic flows. A series of test simulations for a moderate-size microchannel indicates that a high degree of grid under-resolution in the streamwise direction may be tolerated without loss of accuracy. In addition, the results demonstrate the importance of physically correct boundary conditions, as well as possibilities for reducing the time associated with the transient phase of a simulation. These results imply that simulations of longer ducts may be more feasible than previously envisioned.

Conditional truncated plurigaussian simulation; Simulacao plurigaussiana truncada com condicionamento

Energy Technology Data Exchange (ETDEWEB)

Simon, Vitor Hugo

1997-12-01

The goal of this work was a development of an algorithm for the Truncated Plurigaussian Stochastic Simulation and its validation in a complex geologic model. The reservoir data comes from Aux Vases Zone at Rural Hill Field in Illinois, USA, and from the 2D geological interpretation, described by WEIMER et al. (1982), three sets of samples, with different grid densities ware taken. These sets were used to condition the simulation and to refine the estimates of the non-stationary matrix of facies proportions, used to truncate the gaussian random functions (RF). The Truncated Plurigaussian Model is an extension of the Truncated Gaussian Model (TG). In this new model its possible to use several facies with different spatial structures, associated with the simplicity of TG. The geological interpretation, used as a validation model, was chosen because it shows a set of NW/SE elongated tidal channels cutting the NE/SW shoreline deposits interleaved by impermeable facies. These characteristics of spatial structures of sedimentary facies served to evaluate the simulation model. Two independent gaussian RF were used, as well as an 'erosive model' as the truncation strategy. Also, non-conditional simulations were proceeded, using linearly combined gaussian RF with varying correlation coefficients. It was analyzed the influence of some parameters like: number of gaussian RF,correlation coefficient, truncations strategy, in the outcome of simulation, and also the physical meaning of these parameters under a geological point of view. It was showed, step by step, using an example, the theoretical model, and how to construct an algorithm to simulate with the Truncated Plurigaussian Model. The conclusion of this work was that even with a plain algorithm of the Conditional Truncated Plurigaussian and a complex geological model it's possible to obtain a usefulness product. (author)

Early Developmental Conditioning of Later Health and Disease: Physiology or Pathophysiology?

Science.gov (United States)

Hanson, M. A.; Gluckman, P. D.

2014-01-01

Extensive experimental animal studies and epidemiological observations have shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic, especially noncommunicable, disease (NCD). This field is recognized as the developmental origins of health and disease (DOHaD). We discuss the extent to which DOHaD represents the result of the physiological processes of developmental plasticity, which may have potential adverse consequences in terms of NCD risk later, or whether it is the manifestation of pathophysiological processes acting in early life but only becoming apparent as disease later. We argue that the evidence suggests the former, through the operation of conditioning processes induced across the normal range of developmental environments, and we summarize current knowledge of the physiological processes involved. The adaptive pathway to later risk accords with current concepts in evolutionary developmental biology, especially those concerning parental effects. Outside the normal range, effects on development can result in nonadaptive processes, and we review their underlying mechanisms and consequences. New concepts concerning the underlying epigenetic and other mechanisms involved in both disruptive and nondisruptive pathways to disease are reviewed, including the evidence for transgenerational passage of risk from both maternal and paternal lines. These concepts have wider implications for understanding the causes and possible prevention of NCDs such as type 2 diabetes and cardiovascular disease, for broader social policy and for the increasing attention paid in public health to the lifecourse approach to NCD prevention. PMID:25287859

Human Estimation of Slope, Distance, and Height of Terrain in Simulated Lunar Conditions

National Research Council Canada - National Science Library

Oravetz, Christopher

2009-01-01

.... These unique lunar conditions are expected to affect human perception: the lack of an atmosphere, the non-Lambertian regolith reflectance properties, the lack of familiar objects, and the physiological effects of reduced gravity...

Gonadotropins studies in female egyptian subjects under different physiological conditions

International Nuclear Information System (INIS)

El-Nabarawy, F.S.; Megahed, Y.M.; Ibrahim, M.

2002-01-01

This study is concerned with the role of the hypothalamic hypophyseal regulatory hormonal mechanisms in the control of gonadal secretions in a selected normal egyptian female subjects with varying ages under different physiological conditions. The study allowed precise definition of the modulator influence of a number of key factors triggering appropriate alteration in circulating serum levels of FSH and LH determined by IRMA technique in pre-pubertal female children (9-11), post-pubertal adolescents females (13-16). Adult married females (27-33) and post-menopausal (58-63). The levels of FSH and LH were increased markedly with age but children less than 11 years old had only nocturnal increase in levels of FSH (p.O.I) and LH(P< 0.001). post-pubertal aged girls had significant nocturnal elevation only of LH levels (P< 0.001), adult married females did not exhibit significant difference in gonadotropin concentrations. whereas significant elevation in FSH and LH levels (P<0.001) in post-menopausal females were observed

Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.

Science.gov (United States)

Taylor, Nigel A S; Burdon, Catriona A; van den Heuvel, Anne M J; Fogarty, Alison L; Notley, Sean R; Hunt, Andrew P; Billing, Daniel C; Drain, Jace R; Silk, Aaron J; Patterson, Mark J; Peoples, Gregory E

2016-02-01

This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.

Effect of Propolis Oral Intake on Physiological Condition of Young Worker Honey Bees, Apis Mellifera L.

Directory of Open Access Journals (Sweden)

Damiani Natalia

2017-12-01

Full Text Available Honey bees collect resin from various plant species and transform it into propolis that is incorporated into the nest. The role of resins in the bee health field is poorly understood. The aim was to evaluate the effects of forced consumption of propolis on the physiological condition and short-term survival of Apis mellifera worker bees. It was tested if the number of circulating hemocytes in hemolymph, the abdominal fat bodies and the hypopharyngeal glands development were affected by the feeding with propolis extracts in laboratory conditions during the warm and the cold seasons. Propolis added to sugar candy was consumed by workers for fourteen days without affecting the bee survival. The number of circulating hemocytes in hemolymph remained constant despite the differential diet during the experiment. However, the development of fat bodies and hypopharyngeal glands was altered by propolis ingestion. The abdominal fat body development in winter bees diminished after fourteen days of propolis consumption, while it increased in summer bees. The hypopharyngeal gland development decreased for the assayed period in workers from both seasons. Our results encourage us to continue exploring this research field and learn how long-term forced ingestion of a plant-derived compound, a non-nutritive substance, can modify physiological bee parameters. A broader understanding of the multiple roles of propolis in the health of the honey bee colonies could be obtained by studying the ways in which it is processed and metabolized and the effect that generates in another physiological responses.

Limestone attrition under simulated oxyfiring Fluidized-Bed combustion conditions

Energy Technology Data Exchange (ETDEWEB)

Scala, F. [Istituto di Ricerche sulla Combustione - CNR, Napoli (Italy); Salatino, P. [Dipartimento di Ingegneria Chimica - Universita degli Studi di Napoli Federico II, Napoli (Italy)

2009-03-15

Limestone attrition by surface wear was studied during the flue gas desulfurization under simulated fluidized-bed (FB) oxyfiring conditions and hindered calcination. Bench-scale experimental tests were carried out using well-established techniques previously developed for the characterization of sulfation and attrition of sorbents in air-blown atmospheric FB combustors. The experimental limestone conversion and attrition results were compared with those previously obtained with the same limestone under simulated air-blown combustion conditions. The differences in the conversion and attrition extents and patterns associated with oxyfiring as compared to air-blown atmospheric combustion were highlighted and related to the different particle morphologies and thicknesses of the sulfate layer. It was noted that attrition could play an important role in practical circulating FB combustor operation, by effectively enhancing particle sulfation under both oxyfiring and air-blown combustion conditions. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Diffuse optical tomography with physiological and spatial a priori constraints

International Nuclear Information System (INIS)

Intes, Xavier; Maloux, Clemence; Guven, Murat; Yazici, Birzen; Chance, Britton

2004-01-01

Diffuse optical tomography is a typical inverse problem plagued by ill-condition. To overcome this drawback, regularization or constraining techniques are incorporated in the inverse formulation. In this work, we investigate the enhancement in recovering functional parameters by using physiological and spatial a priori constraints. More accurate recovery of the two main functional parameters that are the blood volume and the relative saturation is demonstrated through simulations by using our method compared to actual techniques. (note)

Visible implant elastomer (VIE) tagging and simulated predation risk elicit similar physiological stress responses in three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Fürtbauer, I; King, A J; Heistermann, M

2015-05-01

The effect of visible implant elastomer (VIE) tagging on the immediate physiological stress response was tested in female three-spined stickleback Gasterosteus aculeatus, using non-invasive waterborne cortisol analysis. Post-tagging cortisol levels were significantly higher compared with pretreatment baseline concentrations; however, when comparing post-tagging cortisol levels with cortisol levels after exposure to a simulated aerial predator, no significant differences were found. This study indicates that VIE tagging elicits a physiological stress response similar to those occurring in the everyday lives of this important biological model organism. © 2015 The Fisheries Society of the British Isles.

Temperature-induced physiological stress and reproductive characteristics of the migratory seahorse Hippocampus erectus during a thermal stress simulation.

Science.gov (United States)

Qin, Geng; Johnson, Cara; Zhang, Yuan; Zhang, Huixian; Yin, Jianping; Miller, Glen; Turingan, Ralph G; Guisbert, Eric; Lin, Qiang

2018-05-15

Inshore-offshore migration occurs frequently in seahorse species either because of prey opportunities or because it is driven by reproduction, and variations in water temperature may dramatically change migratory seahorse behavior and physiology. The present study investigated the behavioral and physiological responses of the lined seahorse Hippocampus erectus under thermal stress and evaluated the potential effects of different temperatures on its reproduction. The results showed that the thermal tolerance of the seahorses was time dependent. Acute thermal stress (30°C, 2-10 hours) increased the basal metabolic rate (breathing rate) and the expression of stress response genes ( Hsp genes) significantly and further stimulated seahorse appetite. Chronic thermal treatment (30°C, 4 weeks) led to a persistently higher basal metabolic rate, higher stress response gene expression, and higher mortality, indicating that the seahorses could not acclimate to chronic thermal stress and might experience massive mortality due to excessive basal metabolic rates and stress damage. Additionally, no significant negative effects on gonad development or reproductive endocrine regulation genes were observed in response to chronic thermal stress, suggesting that seahorse reproductive behavior could adapt to higher-temperature conditions during migration and within seahorse breeding grounds. In conclusion, this simulation experiment indicated that temperature variations during inshore-offshore migration have no effect on reproduction but promote basal metabolic rates and stress responses significantly. Therefore, we suggest that the high observed tolerance of seahorse reproduction was in line with the inshore-offshore reproductive migration pattern of lined seahorse. © 2018. Published by The Company of Biologists Ltd.

Hydrogen deflagration simulations under typical containment conditions for nuclear safety

Energy Technology Data Exchange (ETDEWEB)

Yanez, J., E-mail: jorge.yanez@kit.edu [Institute for Energy and Nuclear Technology, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe (Germany); Kotchourko, A.; Lelyakin, A. [Institute for Energy and Nuclear Technology, Karlsruhe Institute of Technology, Kaiserstrasse 12, 76131 Karlsruhe (Germany)

2012-09-15

Highlights: Black-Right-Pointing-Pointer Lean H{sub 2}-air combustion experiments highly relevant to typical NPP simulated. Black-Right-Pointing-Pointer Analyzed effect of temperature, concentration of H{sub 2}, and steam concentration. Black-Right-Pointing-Pointer Similar conditions and H{sub 2} concentration yielded different combustion regimes. Black-Right-Pointing-Pointer Flame instabilities (FIs) were the effect driving divergences. Black-Right-Pointing-Pointer Model developed for acoustic FI in simulations. Agreement experiments obtained. - Abstract: This paper presents the modeling of low-concentration hydrogen deflagrations performed with the recently developed KYLCOM model specially created to perform calculations in large scale domains. Three experiments carried out in THAI facility (performed in the frames of international OECD THAI experimental program) were selected to be analyzed. The tests allow studying lean mixture hydrogen combustion at normal ambient, elevated temperature and superheated and saturated conditions. The experimental conditions considered together with the facility size and shape grant a high relevance degree to the typical NPP containment conditions. The results of the simulations were thoroughly compared with the experimental data, and the comparison was supplemented by the analysis of the combustion regimes taking place in the considered tests. Results of the analysis demonstrated that despite the comparatively small difference in mixture properties, three different combustion regimes can be definitely identified. The simulations of one of the cases required of the modeling of the acoustic-parametric instability which was carefully undertaken.

Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines.

Science.gov (United States)

Deikumah, Justus P; McAlpine, Clive A; Maron, Martine

2015-01-01

Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L) ratios (an indicator of elevated chronic stress) to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.

Effects of Uncertainties in Electric Field Boundary Conditions for Ring Current Simulations

Science.gov (United States)

Chen, Margaret W.; O'Brien, T. Paul; Lemon, Colby L.; Guild, Timothy B.

2018-01-01

Physics-based simulation results can vary widely depending on the applied boundary conditions. As a first step toward assessing the effect of boundary conditions on ring current simulations, we analyze the uncertainty of cross-polar cap potentials (CPCP) on electric field boundary conditions applied to the Rice Convection Model-Equilibrium (RCM-E). The empirical Weimer model of CPCP is chosen as the reference model and Defense Meteorological Satellite Program CPCP measurements as the reference data. Using temporal correlations from a statistical analysis of the "errors" between the reference model and data, we construct a Monte Carlo CPCP discrete time series model that can be generalized to other model boundary conditions. RCM-E simulations using electric field boundary conditions from the reference model and from 20 randomly generated Monte Carlo discrete time series of CPCP are performed for two large storms. During the 10 August 2000 storm main phase, the proton density at 10 RE at midnight was observed to be low (Dst index is bounded by the simulated Dst values. In contrast, the simulated Dst values during the recovery phases of the 10 August 2000 and 31 August 2005 storms tend to underestimate systematically the observed late Dst recovery. This suggests a need to improve the accuracy of particle loss calculations in the RCM-E model. Application of this technique can aid modelers to make efficient choices on either investing more effort on improving specification of boundary conditions or on improving descriptions of physical processes.

Plasticity in physiological condition of female brown bears across diverse ecosystems

Science.gov (United States)

Hilderbrand, Grant V.; Gustine, David; Mangipane, Buck A.; Joly, Kyle; Leacock, William; Mangipane, Lindsey; Erlenbach, Joy; Sorum, Mathew; Cameron, Matthew; Belant, Jerrold L.; Cambier, Troy

2018-01-01

Variation in life history strategies facilitates the near global distribution of mammals by expanding realized niche width. We investigated physiological plasticity in the spring body composition of adult female brown bears (Ursus arctos) across 4 diverse Alaskan ecosystems. Brown bears are a highly intelligent omnivore with a historic range spanning much of North America, Europe, and Asia. We hypothesized that body mass, fat mass, lean mass, and total caloric content would increase across populations with increasing food resource availability. Throughout their range, brown bears enter a period of torpor during winter months, decreasing their metabolic rate as an adaptation to this period of reduced food availability. They also give birth to and nourish offspring during this time. Due to this specific life history strategy, we further hypothesized that proportional body fat and the proportion of total calories derived from fat would be consistent across populations. Our results supported our first hypothesis: body, fat, and lean masses, and caloric content of bears across populations increased with the quality and abundance of available food. However, the proportional body fat content and proportion of calories from fat differed across populations indicating population-specific strategies to meet the demands of reduced seasonal food availability, offspring production and rearing, and climate as well as some plasticity to respond to environmental change or ecosystem perturbations. Investigations of body condition and energetics benefit from combined assessments of absolute, proportional, and caloric metrics to understand the nuances of brown bear physiological dynamics across and within populations.

Slamming Simulations in a Conditional Wave

DEFF Research Database (Denmark)

Seng, Sopheak; Jensen, Jørgen Juncher

2012-01-01

A study of slamming events in conditional waves is presented in this paper. The ship is sailing in head sea and the motion is solved for under the assumption of rigid body motion constrained to two degree-of-freedom i.e. heave and pitch. Based on a time domain non-linear strip theory most probable...... surface NS/VOF CFD simulations under the same wave conditions. In moderate seas and no occurrence of slamming the structural responses predicted by the methods agree well. When slamming occurs the strip theory overpredicts VBM but the peak values of VBM occurs at approximately the same time as predicted...... by the CFD method implying the possibility to use the more accurate CFD results to improve the estimation of slamming loads in the strip theory through a rational correction coefficient....

Plasma-material interaction under simulated disruption conditions

International Nuclear Information System (INIS)

Arkhipov, N.I.; Bakhtin, V.P.; Safronov, V.M.; Toporkov, D.A.; Vasenin, S.G.; Wurz, H.; Zhitlukhin, A.M.

1995-01-01

Sudden evaporation of divertor plate surface under high heat load during tokamak plasma disruption instantaneously produces a vapor shield. The cloud of vaporized material prevents the divertor plates from the bulk of incoming energy flux and thus reduces the further material erosion. Dynamics and effectiveness of the vapor shield are studied experimentally at the 2MK-200 facility under simulated disruption conditions. (orig.)

Gender differences in exerted forces and physiological load during pushing and pulling of wheeled cages by postal workers

NARCIS (Netherlands)

Van Der Beek, Allard J.; Kluver, B.D.R.; Frings-Dresen, M. H. W.; Hoozemans, M. J M

The aim was to determine gender differences regarding exerted forces and physiological load during push/pull tasks simulating the daily working practice of postal workers. Eight female and four male workers handled four-wheeled cages under eight conditions corresponding to the cage weight (130, 250,

Training for Translocation: Predator Conditioning Induces Behavioral Plasticity and Physiological Changes in Captive Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis (Cryptobranchidae, Amphibia

Directory of Open Access Journals (Sweden)

Erin K. Kenison

2018-03-01

Full Text Available Translocations are stressful, especially when captive animals are naïve to natural stimuli. Captive eastern hellbenders (Cryptobranchus alleganiensis alleganiensis identify predatory fish as threats, but may be more vulnerable to predation and stress because of inexperience with them. We investigated the use of predator conditioning to prepare hellbenders, behaviorally and physiologically, for the presence of a common predator, largemouth bass (Micropterus salmoides. We reared hellbenders for 30 d with and without continuous exposure to largemouth bass kairomones and heterospecific alarm cues and found conditioned hellbenders became less active compared to unconditioned individuals (p = 0.017. After conditioning, we exposed hellbenders to water, a low concentration of kairomones, or a high concentration of kairomones in a closed respirometer system. We measured activity within respirometer chambers and routine metabolic rate. We found unconditioned hellbenders exposed to low and high concentrations of kairomones were 41% and 119% more active than conditioned animals (p = 0.002 and p < 0.001. Moreover, conditioned individuals had on average 6.5% lower metabolic rates across all three kairomone concentrations compared to unconditioned individuals (p = 0.017. Our data suggest that predator conditioning induces behavioral avoidance tactics and physiological changes that could improve future translocation efforts for hellbenders and other imperiled species.

Development of simulation technology on full auto air conditioning system; Auto eakon no simulation gijutsu no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Fujita, N; Otsubo, Y; Matsumura, K; Sako, H [Mazda Motor Corp., Hiroshima (Japan)

1997-10-01

Mazda has developed simulation technology on control of full auto air conditioning system. We have developed the development tool based on the technology, aiming at higher controllability of full auto air conditioning system and shorter development period. The tool performs simulation on control, on-vehicle evaluation of actual load operation, collecting data and analyzing them by personal computer. This paper reports our verification results on effectiveness of the technology/ and the tool. 4 refs., 9 figs.

Simulation study on the maximum continuous working condition of a power plant boiler

Science.gov (United States)

Wang, Ning; Han, Jiting; Sun, Haitian; Cheng, Jiwei; Jing, Ying'ai; Li, Wenbo

2018-05-01

First of all, the boiler is briefly introduced to determine the mathematical model and the boundary conditions, then the boiler under the BMCR condition numerical simulation study, and then the BMCR operating temperature field analysis. According to the boiler actual test results and the hot BMCR condition boiler output test results, the simulation results are verified. The main conclusions are as follows: the position and size of the inscribed circle in the furnace and the furnace temperature distribution and test results under different elevation are compared and verified; Accuracy of numerical simulation results.

The role of performing life support courses in rural areas in improving pre-hospital physiologic conditions of patients with penetrating injuries.

Science.gov (United States)

Nia, Masoud Saghafi; Naffisi, Nahid; Mohebbi, Hassan Ali; Moharamzadeh, Yashar

2008-09-01

To evaluate the impact of animal model based medical training courses for village healthcare workers on prehospital physiologic condition and prognosis of patients with penetrating injuries. Experimental study. This study was carried out in Mehran city and its neighbouring rural districts in western part of Iran from 2002 to 2004. Seventy-six village healthcare workers were trained and equipped to deliver in-field medical first cares. First group (226 patients) consisted of those who received this cares by the trained group and second group (245 patients) were those who received no in-field cares and were transported directly to the trauma center in provincial capital, Ilam. Physiologic Severity Score (PSS) was calculated to determine the physiologic condition of patients in both groups. The most prevalent cause of trauma in both groups was car accidents (61.6%). Controlling of hemorrhage was the most frequent provided initial medical care (40.6%). A significant improvement regarding the PSS score was observed in the first group of patients compared to the second group (7.505 vs. 6.799, 95% CI for difference: 0.3 to 0.9). The mortality rates of the first and second group of patients were 3% and 7.3%, respectively (p=0.051). Performing life support courses in rural areas of low-income countries where there is no pre-hospital triage and emergency medical system and provision of classic resuscitative measures are limited, has a significant impact on improvement of pre-hospital physiologic condition and prognosis of patients with penetrating injuries.

Dynamics Modeling and Simulation of Large Transport Airplanes in Upset Conditions

Science.gov (United States)

Foster, John V.; Cunningham, Kevin; Fremaux, Charles M.; Shah, Gautam H.; Stewart, Eric C.; Rivers, Robert A.; Wilborn, James E.; Gato, William

2005-01-01

As part of NASA's Aviation Safety and Security Program, research has been in progress to develop aerodynamic modeling methods for simulations that accurately predict the flight dynamics characteristics of large transport airplanes in upset conditions. The motivation for this research stems from the recognition that simulation is a vital tool for addressing loss-of-control accidents, including applications to pilot training, accident reconstruction, and advanced control system analysis. The ultimate goal of this effort is to contribute to the reduction of the fatal accident rate due to loss-of-control. Research activities have involved accident analyses, wind tunnel testing, and piloted simulation. Results have shown that significant improvements in simulation fidelity for upset conditions, compared to current training simulations, can be achieved using state-of-the-art wind tunnel testing and aerodynamic modeling methods. This paper provides a summary of research completed to date and includes discussion on key technical results, lessons learned, and future research needs.

Conditional flood frequency and catchment state: a simulation approach

Science.gov (United States)

Brettschneider, Marco; Bourgin, François; Merz, Bruno; Andreassian, Vazken; Blaquiere, Simon

2017-04-01

Catchments have memory and the conditional flood frequency distribution for a time period ahead can be seen as non-stationary: it varies with the catchment state and climatic factors. From a risk management perspective, understanding the link of conditional flood frequency to catchment state is a key to anticipate potential periods of higher flood risk. Here, we adopt a simulation approach to explore the link between flood frequency obtained by continuous rainfall-runoff simulation and the initial state of the catchment. The simulation chain is based on i) a three state rainfall generator applied at the catchment scale, whose parameters are estimated for each month, and ii) the GR4J lumped rainfall-runoff model, whose parameters are calibrated with all available data. For each month, a large number of stochastic realizations of the continuous rainfall generator for the next 12 months are used as inputs for the GR4J model in order to obtain a large number of stochastic realizations for the next 12 months. This process is then repeated for 50 different initial states of the soil moisture reservoir of the GR4J model and for all the catchments. Thus, 50 different conditional flood frequency curves are obtained for the 50 different initial catchment states. We will present an analysis of the link between the catchment states, the period of the year and the strength of the conditioning of the flood frequency compared to the unconditional flood frequency. A large sample of diverse catchments in France will be used.

Do downscaled general circulation models reliably simulate historical climatic conditions?

Science.gov (United States)

Bock, Andrew R.; Hay, Lauren E.; McCabe, Gregory J.; Markstrom, Steven L.; Atkinson, R. Dwight

2018-01-01

The accuracy of statistically downscaled (SD) general circulation model (GCM) simulations of monthly surface climate for historical conditions (1950–2005) was assessed for the conterminous United States (CONUS). The SD monthly precipitation (PPT) and temperature (TAVE) from 95 GCMs from phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5) were used as inputs to a monthly water balance model (MWBM). Distributions of MWBM input (PPT and TAVE) and output [runoff (RUN)] variables derived from gridded station data (GSD) and historical SD climate were compared using the Kolmogorov–Smirnov (KS) test For all three variables considered, the KS test results showed that variables simulated using CMIP5 generally are more reliable than those derived from CMIP3, likely due to improvements in PPT simulations. At most locations across the CONUS, the largest differences between GSD and SD PPT and RUN occurred in the lowest part of the distributions (i.e., low-flow RUN and low-magnitude PPT). Results indicate that for the majority of the CONUS, there are downscaled GCMs that can reliably simulate historical climatic conditions. But, in some geographic locations, none of the SD GCMs replicated historical conditions for two of the three variables (PPT and RUN) based on the KS test, with a significance level of 0.05. In these locations, improved GCM simulations of PPT are needed to more reliably estimate components of the hydrologic cycle. Simple metrics and statistical tests, such as those described here, can provide an initial set of criteria to help simplify GCM selection.

Matrix Intensification Affects Body and Physiological Condition of Tropical Forest-Dependent Passerines.

Directory of Open Access Journals (Sweden)

Justus P Deikumah

Full Text Available Matrix land-use intensification is a relatively recent and novel landscape change that can have important influences on the biota within adjacent habitat patches. While there are immediate local changes that it brings about, the influences on individual animals occupying adjacent habitats may be less evident initially. High-intensity land use could induce chronic stress in individuals in nearby remnants, leading ultimately to population declines. We investigated how physiological indicators and body condition measures of tropical forest-dependent birds differ between forest adjacent to surface mining sites and that near farmlands at two distances from remnant edge in southwest Ghana. We used mixed effects models of several condition indices including residual body mass and heterophil to lymphocyte (H/L ratios (an indicator of elevated chronic stress to explore the effect of matrix intensity on forest-dependent passerines classed as either sedentary area-sensitive habitat specialists or nomadic generalists. Individual birds occupying tropical forest remnants near surface mining sites were in poorer condition, as indicated by lower residual body mass and elevated chronic stress, compared to those in remnants near agricultural lands. The condition of the sedentary forest habitat specialists white-tailed alethe, Alethe diademata and western olive sunbird, Cyanomitra obscura was most negatively affected by high-intensity surface mining land-use adjacent to remnants, whereas generalist species were not affected. Land use intensification may set in train a new trajectory of faunal relaxation beyond that expected based on habitat loss alone. Patterns of individual condition may be useful in identifying habitats where species population declines may occur before faunal relaxation has concluded.

Analysis and simulation of mobile air conditioning system coupled with engine cooling system

International Nuclear Information System (INIS)

Qi, Zhao-gang; Chen, Jiang-ping; Chen, Zhi-jiu

2007-01-01

Many components of the mobile air conditioning system and engine cooling system are closely interrelated and make up the vehicle climate control system. In the present paper, a vehicle climate control system model including air conditioning system and engine cooling system has been proposed under different operational conditions. All the components have been modeled on the basis of experimental data. Based on the commercial software, a computer simulation procedure of the vehicle climate control system has been developed. The performance of the vehicle climate control system is simulated, and the calculational data have good agreement with experimental data. Furthermore, the vehicle climate control simulation results have been compared with an individual air conditioning system and engine cooling system. The influences between the mobile air conditioning system and the engine cooling system are discussed

Physiological responses and performance in a simulated trampoline gymnastics competition in elite male gymnasts.

Science.gov (United States)

Jensen, Peter; Scott, Suzanne; Krustrup, Peter; Mohr, Magni

2013-01-01

Physiological responses and performance were examined during and after a simulated trampoline competition (STC). Fifteen elite trampoline gymnasts participated, of which eight completed two routines (EX1 and EX2) and a competition final (EX3). Trampoline-specific activities were quantified by video-analysis. Countermovement jump (CMJ) and 20 maximal trampoline jump (20-MTJ) performances were assessed. Heart rate (HR) and quadriceps muscle temperature (Tm) were recorded and venous blood was drawn. A total of 252 ± 16 jumps were performed during the STC. CMJ performance declined (P trampoline gymnastic competition includes a high number of repeated explosive and energy demanding jumps, which impairs jump performance during and 24 h post-competition.

Simulation of hydrocephalus condition in infant head

Science.gov (United States)

Wijayanti, Erna; Arif, Idam

2014-03-01

Hydrocephalus is a condition of an excessive of cerebrospinal fluid in brain. In this paper, we try to simulate the behavior of hydrocephalus conditions in infant head by using a hydro-elastic model which is combined with orthotropic elastic skull and with the addition of suture that divide the skull into two lobes. The model then gives predictions for the case of stenosis aqueduct by varying the cerebral aqueduct diameter, time constant and brain elastic modulus. The hydrocephalus condition which is shown by the significant value of ventricle displacement, as the result shows, is occurred when the aqueduct is as resistant as brain parenchyma for the flow of cerebrospinal fluid. The decrement of brain elastic modulus causes brain parenchyma displacement value approach ventricle displacement value. The smaller of time constant value causes the smaller value of ventricle displacement.

Protein patterns of black fungi under simulated Mars-like conditions.

Science.gov (United States)

Zakharova, Kristina; Marzban, Gorji; de Vera, Jean-Pierre; Lorek, Andreas; Sterflinger, Katja

2014-05-29

Two species of microcolonial fungi - Cryomyces antarcticus and Knufia perforans - and a species of black yeasts-Exophiala jeanselmei - were exposed to thermo-physical Mars-like conditions in the simulation chamber of the German Aerospace Center. In this study the alterations at the protein expression level from various fungi species under Mars-like conditions were analyzed for the first time using 2D gel electrophoresis. Despite of the expectations, the fungi did not express any additional proteins under Mars simulation that could be interpreted as stress induced HSPs. However, up-regulation of some proteins and significant decreasing of protein number were detected within the first 24 hours of the treatment. After 4 and 7 days of the experiment protein spot number was increased again and the protein patterns resemble the protein patterns of biomass from normal conditions. It indicates the recovery of the metabolic activity under Martian environmental conditions after one week of exposure.

The physiology of ex vitro pineapple (Ananas comosus L. Merr. var MD-2) as CAM or C3 is regulated by the environmental conditions.

Science.gov (United States)

Aragón, C; Carvalho, L; González, J; Escalona, M; Amancio, S

2012-04-01

Many plant species grown under in vitro controlled conditions can be used as models for the study of physiological processes. Adult pineapple can display CAM physiology while in vitro it functions as a C3 plant. Ex vitro Ananas comosus has plastic morphology and physiology, both easy to modify from C3 to CAM by changing the environmental conditions. The yield of survival for a rentable propagation protocol of pineapple is closely related with the C3/CAM shift and the associated physiological characteristics. In the present work, ex vitro pineapple plants were divided in two sets and subjected to C3 and CAM-inducing environmental conditions, determined by light intensity and relative humidity, respectively, 40 μmol m(-2) s(-1)/85% and 260 μmol m(-2) s(-1)/50%. The results demonstrated that the stress imposed by the environmental conditions switched pineapple plants from C3 to CAM behavior. Comparing to CAM induced, C3-induced pineapple plants showed substandard growth parameters and morphological leaf characteristics but a better rooting process and a higher ABA production, a phenotype closer to adult plants, which are expected to produce fruits in a normal production cycle. We conclude that the upholding of these characteristics is conditioned by low light intensity plus high relative humidity, especially during the first 8 weeks of ex vitro growth. It is expected that the better understanding of pineapple acclimatization will contribute to the design of a protocol to apply as a rentable tool in the pineapple agronomic industry. © Springer-Verlag 2011

Integration of an optical coherence tomography (OCT) system into an examination incubator to facilitate in vivo imaging of cardiovascular development in higher vertebrate embryos under stable physiological conditions

DEFF Research Database (Denmark)

Happel, Christoph M.; Thrane, Lars; Thommes, Jan

2011-01-01

High-resolution in vivo imaging of higher vertebrate embryos over short or long time periods under constant physiological conditions is a technically challenging task for researchers working on cardiovascular development. In chick embryos, for example, various studies have shown that without...... significance, should be documented under physiological conditions. However, previous studies were mostly carried out outside of an incubator or under suboptimal environmental conditions. Here we present, to the best of our knowledge, the first detailed description of an optical coherence tomography (OCT......) system integrated into an examination incubator to facilitate real-time in vivo imaging of cardiovascular development under physiological environmental conditions. We demonstrate the suitability of this OCT examination incubator unit for use in cardiovascular development studies by examples of proof...

Influence of Contact Angle Boundary Condition on CFD Simulation of T-Junction

Science.gov (United States)

Arias, S.; Montlaur, A.

2018-03-01

In this work, we study the influence of the contact angle boundary condition on 3D CFD simulations of the bubble generation process occurring in a capillary T-junction. Numerical simulations have been performed with the commercial Computational Fluid Dynamics solver ANSYS Fluent v15.0.7. Experimental results serve as a reference to validate numerical results for four independent parameters: the bubble generation frequency, volume, velocity and length. CFD simulations accurately reproduce experimental results both from qualitative and quantitative points of view. Numerical results are very sensitive to the gas-liquid-wall contact angle boundary conditions, confirming that this is a fundamental parameter to obtain accurate CFD results for simulations of this kind of problems.

Simulating Physiological Response with a Passive Sensor Manikin and an Adaptive Thermal Manikin to Predict Thermal Sensation and Comfort

Energy Technology Data Exchange (ETDEWEB)

Rugh, John P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chaney, Larry [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hepokoski, Mark [ThermoAnalytics Inc.; Curran, Allen [ThermoAnalytics Inc.; Burke, Richard [Measurement Technology NW; Maranville, Clay [Ford Motor Company

2015-04-14

Reliable assessment of occupant thermal comfort can be difficult to obtain within automotive environments, especially under transient and asymmetric heating and cooling scenarios. Evaluation of HVAC system performance in terms of comfort commonly requires human subject testing, which may involve multiple repetitions, as well as multiple test subjects. Instrumentation (typically comprised of an array of temperature sensors) is usually only sparsely applied across the human body, significantly reducing the spatial resolution of available test data. Further, since comfort is highly subjective in nature, a single test protocol can yield a wide variation in results which can only be overcome by increasing the number of test replications and subjects. In light of these difficulties, various types of manikins are finding use in automotive testing scenarios. These manikins can act as human surrogates from which local skin and core temperatures can be obtained, which are necessary for accurately predicting local and whole body thermal sensation and comfort using a physiology-based comfort model (e.g., the Berkeley Comfort Model). This paper evaluates two different types of manikins, i) an adaptive sweating thermal manikin, which is coupled with a human thermoregulation model, running in real-time, to obtain realistic skin temperatures; and, ii) a passive sensor manikin, which is used to measure boundary conditions as they would act on a human, from which skin and core temperatures can be predicted using a thermophysiological model. The simulated physiological responses and comfort obtained from both of these manikin-model coupling schemes are compared to those of a human subject within a vehicle cabin compartment transient heat-up scenario.

Alternate furrow irrigation of four fresh-market tomato cultivars under semi-arid condition of Ethiopia – Part II: Physiological response

Directory of Open Access Journals (Sweden)

Ashinie Bogale

2016-11-01

Full Text Available Understanding the variation in physiological response to deficit irrigation together with better knowledge on physiological characteristics of different genotypes that contribute to drought adaptation mechanisms would be helpful in transferring different irrigation technologies to farmers. A field experiment was carried to investigate the physiological response of four tomato cultivars (Fetan, Chali, Cochoro and ARP Tomato d2 to moderate water deficit induced by alternate furrow irrigation (AFI and deficit irrigation (DI under semi-arid condition of Ethiopia during 2013 and 2014. The study also aimed at identifying physiological attributes to the fruit yield of tomato under different deficit irrigation techniques. A factorial combination of irrigation treatments and cultivar were arranged in a complete randomized design with three replicates. Results showed that stomatal conductance (g_s was significantly reduced while photosynthetic performance measured as chlorophyll fluorescence (Fv’/Fm’, relative water content (RWC and leaf ash content remained unaffected under deficit irrigations. Significant differences among cultivars were found for water use efficiency (WUE, g_s, chlorophyll content (Chl_SPAD, normal difference vegetation index (NDVI, leaf ash content and fruit growth rate. However, cultivar differences in WUE were more accounted for by the regulation of g_s, therefore, g_s could be useful for breeders for screening large numbers of genotypes with higher WUE under deficit irrigation condition. The study result also demonstrated that cultivar with traits that contribute to achieve higher yields under deficit irrigation strategies has the potential to increase WUE.

Qualidade fisiológica de sementes de soja submetidas ao hidrocondicionamento = Soybean seed physiological quality after hydro-conditioning

Directory of Open Access Journals (Sweden)

Maria Izabel Krüger Giurizatto

2008-12-01

Full Text Available A técnica de hidratação controlada de sementes vem sendo utilizada como método de condicionamento fisiológico, tanto para sementes deterioradas como para sementes altamente sensíveis à embebição rápida, ou a interação entre ambas, objetivando melhorar o desempenho destas no campo. A hidratação pode ser seguida por secagem, se assementes não tiverem atingido a fase III da germinação, facilitando, assim, o subseqüente manuseio, armazenamento e semeadura no campo. O objetivo do presente trabalho foi avaliar os efeitos do hidrocondicionamento na qualidade fisiológica de sementes de soja,sendo estas sementes hidrocondicionadas por períodos de 0, 20 e 24h, secas e armazenadas por 0, 90, 180 e 270 dias em câmara seca, com umidade e temperatura controladas. O hidrocondicionamento teve efeito benéfico na qualidade fisiológica das sementes de soja,suas vantagens se tornaram mais evidentes com o envelhecimento natural das sementes durante o armazenamento.Controlled hydration of seeds has been used as a physiological conditioning method, both for deteriorated seeds as well as seeds that are highly sensitive to soaking, or an interaction among both, aiming to improving their performance after sowing in the field. Thehydration must be followed by drying, in case the seeds have not reached yet phase III of germination, thus facilitating subsequent handling, storage and sowing operations. This work aimed to evaluate the hydro-conditioning effect (0, 20 and 24 hours, followed by seeddrying on the physiological quality of soybean seeds, stored in dry chamber under controlled conditions (relative humidity and temperature during 0, 90, 180 and 270 days. Hydro-conditioning has revealed positive effects on the physiological quality of those seedsand its advantage became more evident according to natural aging of the seeds during the storage.

Using High-Resolution Hyperspectral and Thermal Airborne Imagery to Assess Physiological Condition in the Context of Wheat Phenotyping

Directory of Open Access Journals (Sweden)

Victoria Gonzalez-Dugo

2015-10-01

Full Text Available There is a growing need for developing high-throughput tools for crop phenotyping that would increase the rate of genetic improvement. In most cases, the indicators used for this purpose are related with canopy structure (often acquired with RGB cameras and multispectral sensors allowing the calculation of NDVI, but using approaches related with the crop physiology are rare. High-resolution hyperspectral remote sensing imagery provides optical indices related to physiological condition through the quantification of photosynthetic pigment and chlorophyll fluorescence emission. This study demonstrates the use of narrow-band indicators of stress as a potential tool for phenotyping under rainfed conditions using two airborne datasets acquired over a wheat experiment with 150 plots comprising two species and 50 varieties (bread and durum wheat. The flights were performed at the early stem elongation stage and during the milking stage. Physiological measurements made at the time of flights demonstrated that the second flight was made during the terminal stress, known to largely determine final yield under rainfed conditions. The hyperspectral imagery enabled the extraction of thermal, radiance, and reflectance spectra from 260 spectral bands from each plot for the calculation of indices related to photosynthetic pigment absorption in the visible and red-edge regions, the quantification of chlorophyll fluorescence emission, as well as structural indices related to canopy structure. Under the conditions of this study, the structural indices (i.e., NDVI did not show a good performance at predicting yield, probably because of the large effects of terminal water stress. Thermal indices, indices related to chlorophyll fluorescence (calculated using the FLD method, and carotenoids pigment indices (PRI and CAR demonstrated to be better suited for screening complex traits such as crop yield. The study concludes that the indicators derived from high

A graphical simulation software for instruction in cardiovascular mechanics physiology

Directory of Open Access Journals (Sweden)

Wenger Roland H

2011-01-01

Full Text Available Abstract Background Computer supported, interactive e-learning systems are widely used in the teaching of physiology. However, the currently available complimentary software tools in the field of the physiology of cardiovascular mechanics have not yet been adapted to the latest systems software. Therefore, a simple-to-use replacement for undergraduate and graduate students' education was needed, including an up-to-date graphical software that is validated and field-tested. Methods Software compatible to Windows, based on modified versions of existing mathematical algorithms, has been newly developed. Testing was performed during a full term of physiological lecturing to medical and biology students. Results The newly developed CLabUZH software models a reduced human cardiovascular loop containing all basic compartments: an isolated heart including an artificial electrical stimulator, main vessels and the peripheral resistive components. Students can alter several physiological parameters interactively. The resulting output variables are printed in x-y diagrams and in addition shown in an animated, graphical model. CLabUZH offers insight into the relations of volume, pressure and time dependency in the circulation and their correlation to the electrocardiogram (ECG. Established mechanisms such as the Frank-Starling Law or the Windkessel Effect are considered in this model. The CLabUZH software is self-contained with no extra installation required and runs on most of today's personal computer systems. Conclusions CLabUZH is a user-friendly interactive computer programme that has proved to be useful in teaching the basic physiological principles of heart mechanics.

Simulating reservoir lithologies by an actively conditioned Markov chain model

Science.gov (United States)

Feng, Runhai; Luthi, Stefan M.; Gisolf, Dries

2018-06-01

The coupled Markov chain model can be used to simulate reservoir lithologies between wells, by conditioning them on the observed data in the cored wells. However, with this method, only the state at the same depth as the current cell is going to be used for conditioning, which may be a problem if the geological layers are dipping. This will cause the simulated lithological layers to be broken or to become discontinuous across the reservoir. In order to address this problem, an actively conditioned process is proposed here, in which a tolerance angle is predefined. The states contained in the region constrained by the tolerance angle will be employed for conditioning in the horizontal chain first, after which a coupling concept with the vertical chain is implemented. In order to use the same horizontal transition matrix for different future states, the tolerance angle has to be small. This allows the method to work in reservoirs without complex structures caused by depositional processes or tectonic deformations. Directional artefacts in the modeling process are avoided through a careful choice of the simulation path. The tolerance angle and dipping direction of the strata can be obtained from a correlation between wells, or from seismic data, which are available in most hydrocarbon reservoirs, either by interpretation or by inversion that can also assist the construction of a horizontal probability matrix.

A modular open platform for systematic functional studies under physiological conditions

Science.gov (United States)

Mulholland, Christopher B.; Smets, Martha; Schmidtmann, Elisabeth; Leidescher, Susanne; Markaki, Yolanda; Hofweber, Mario; Qin, Weihua; Manzo, Massimiliano; Kremmer, Elisabeth; Thanisch, Katharina; Bauer, Christina; Rombaut, Pascaline; Herzog, Franz; Leonhardt, Heinrich; Bultmann, Sebastian

2015-01-01

Any profound comprehension of gene function requires detailed information about the subcellular localization, molecular interactions and spatio-temporal dynamics of gene products. We developed a multifunctional integrase (MIN) tag for rapid and versatile genome engineering that serves not only as a genetic entry site for the Bxb1 integrase but also as a novel epitope tag for standardized detection and precipitation. For the systematic study of epigenetic factors, including Dnmt1, Dnmt3a, Dnmt3b, Tet1, Tet2, Tet3 and Uhrf1, we generated MIN-tagged embryonic stem cell lines and created a toolbox of prefabricated modules that can be integrated via Bxb1-mediated recombination. We used these functional modules to study protein interactions and their spatio-temporal dynamics as well as gene expression and specific mutations during cellular differentiation and in response to external stimuli. Our genome engineering strategy provides a versatile open platform for efficient generation of multiple isogenic cell lines to study gene function under physiological conditions. PMID:26007658

Transient analysis of multifailure conditions by using PWR plant simulator

International Nuclear Information System (INIS)

Morisaki, Hidetoshi; Yokobayashi, Masao.

1984-11-01

This report describes results of the analysis of abnormal transients caused by multifailures using a PWR plant simulator. The simulator is based on an existing 822MWe power plant with 3 loops, and designed to cover wide range of plant operation from cold shutdown to full power at the end of life. Various malfunctions to simulate abnormal conditions caused by equipment failures are provided. In this report, features of abnormal transients caused by concurrence of malfunctions are discussed. The abnormal conditions studied are leak of primary coolant, loss of charging and feedwater flows, and control systems failure. From the results, it was observed that transient responses caused by some of the malfunctions are almost same as the addition of behaviors caused by each single malfunction. Therefore, it can be said that kinds of malfunctions which are concurrent may be estimated from transient characteristics of each single malfunction. (author)

ANALYSIS OF OPERATING INSTRUMENT LANDING SYSTEM ACCURACY UNDER SIMULATED CONDITIONS

Directory of Open Access Journals (Sweden)

Jerzy MERKISZ

2017-03-01

Full Text Available The instrument landing system (ILS is the most popular landing aid in the world. It is a distance-angled support system for landing in reduced visibility, while its task is the safe conduct of the aircraft from the prescribed course landing on the approach path. The aim of this study is to analyse the correctness of the ILS in simulated conditions. The study was conducted using a CKAS MotionSim5 flight simulator in the Simulation Research Laboratory of the Institute of Combustion Engines and Transport at Poznan University of Technology. With the advancement of technical equipment, it was possible to check the operation of the system in various weather conditions. Studies have shown that the impact of fog, rain and snow on the correct operation of the system is marginal. Significant influence has been observed, however, during landing in strong winds.

Simulation Study of Flap Effects on a Commercial Transport Airplane in Upset Conditions

Science.gov (United States)

Cunningham, Kevin; Foster, John V.; Shah, Gautam H.; Stewart, Eric C.; Ventura, Robin N.; Rivers, Robert A.; Wilborn, James E.; Gato, William

2005-01-01

As part of NASA's Aviation Safety and Security Program, a simulation study of a twinjet transport airplane crew training simulation was conducted to address fidelity for upset or loss of control conditions and to study the effect of flap configuration in those regimes. Piloted and desktop simulations were used to compare the baseline crew training simulation model with an enhanced aerodynamic model that was developed for high-angle-of-attack conditions. These studies were conducted with various flap configurations and addressed the approach-to-stall, stall, and post-stall flight regimes. The enhanced simulation model showed that flap configuration had a significant effect on the character of departures that occurred during post-stall flight. Preliminary comparisons with flight test data indicate that the enhanced model is a significant improvement over the baseline. Some of the unrepresentative characteristics that are predicted by the baseline crew training simulation for flight in the post-stall regime have been identified. This paper presents preliminary results of this simulation study and discusses key issues regarding predicted flight dynamics characteristics during extreme upset and loss-of-control flight conditions with different flap configurations.

specsim: A Fortran-77 program for conditional spectral simulation in 3D

Science.gov (United States)

Yao, Tingting

1998-12-01

A Fortran 77 program, specsim, is presented for conditional spectral simulation in 3D domains. The traditional Fourier integral method allows generating random fields with a given covariance spectrum. Conditioning to local data is achieved by an iterative identification of the conditional phase information. A flowchart of the program is given to illustrate the implementation procedures of the program. A 3D case study is presented to demonstrate application of the program. A comparison with the traditional sequential Gaussian simulation algorithm emphasizes the advantages and drawbacks of the proposed algorithm.

Numerical simulation of controlled directional solidification under microgravity conditions

Science.gov (United States)

Holl, S.; Roos, D.; Wein, J.

The computer-assisted simulation of solidification processes influenced by gravity has gained increased importance during the previous years regarding ground-based as well as microgravity research. Depending on the specific needs of the investigator, the simulation model ideally covers a broad spectrum of applications. These primarily include the optimization of furnace design in interaction with selected process parameters to meet the desired crystallization conditions. Different approaches concerning the complexity of the simulation models as well as their dedicated applications will be discussed in this paper. Special emphasis will be put on the potential of software tools to increase the scientific quality and cost-efficiency of microgravity experimentation. The results gained so far in the context of TEXUS, FSLP, D-1 and D-2 (preparatory program) experiments, highlighting their simulation-supported preparation and evaluation will be discussed. An outlook will then be given on the possibilities to enhance the efficiency of pre-industrial research in the Columbus era through the incorporation of suitable simulation methods and tools.

Psycho-physiological response of soldiers in urban combat

Directory of Open Access Journals (Sweden)

Vicente J. Clemente-Suárez

2013-05-01

Full Text Available Current armed conflicts are asymmetrical and are developed m urban areas. These new requirements have not been studied for current literature. The aim of this study was to analyse changes in cortical arousal, blood lactate, muscle strength, autonomic modulation and rate of perceived exertion in a simulated urban combat. We analyzed 20 soldiers before and after an urban combat simulation. The results showed how urban combat produced high sympathetic nervous system activation, increasing the muscle strength, heart rate and blood lactate concentration of the soldiers. Despite this effort, rate of perceived exertion were not consistent with the physiological response that soldiers presented, the rate of perceived exertion was lower than the physiological response evaluated. Furthermore, the information processing and cortical arousal decreased after the urban combat simulation. These results have showed the psycho-physiological response of soldiers in combat, helping to better understanding and enabling an improvement of current training methods of soldiers.

Simulation of Artificial Intelligence for Automotive Air-conditioning System

Institute of Scientific and Technical Information of China (English)

YUAN Xiao-mei; CHEN You-hua; CHEN Zhi-jiu

2002-01-01

The artificial intelligence is applied to the simulation of the automotive air-conditioning system ( AACS )According to the system's characteristics a model of AACS, based on neural network, is developed. Different control methods of AACS are discussed through simulation based on this model. The result shows that the neural- fuzzy control is the best one compared with the on-off control and conventional fuzzy control method.It can make the compartment's temperature descend rapidly to the designed temperature and the fluctuation is small.

Physiological responses to ocean acidification and warming synergistically reduce condition of the common cockle Cerastoderma edule.

Science.gov (United States)

Ong, E Z; Briffa, M; Moens, T; Van Colen, C

2017-09-01

The combined effect of ocean acidification and warming on the common cockle Cerastoderma edule was investigated in a fully crossed laboratory experiment. Survival of the examined adult organisms remained high and was not affected by elevated temperature (+3 °C) or lowered pH (-0.3 units). However, the morphometric condition index of the cockles incubated under high pCO 2 conditions (i.e. combined warming and acidification) was significantly reduced after six weeks of incubation. Respiration rates increased significantly under low pH, with highest rates measured under combined warm and low pH conditions. Calcification decreased significantly under low pH while clearance rates increased significantly under warm conditions and were generally lower in low pH treatments. The observed physiological responses suggest that the reduced food intake under hypercapnia is insufficient to support the higher energy requirements to compensate for the higher costs for basal maintenance and growth in future high pCO 2 waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

CFD simulation of a four-loop PWR at asymmetric operation conditions

Energy Technology Data Exchange (ETDEWEB)

Cheng, Jian-Ping; Yan, Li-Ming; Li, Feng-Chen, E-mail: lifch@hit.edu.cn

2016-04-15

Highlights: • A CFD numerical simulation procedure was established for simulating RPV of VVER-1000. • The established CFD approach was validated by comparing with available data. • Thermal hydraulic characteristics under asymmetric operation condition were investigated. • Apparent influences of the shutdown loop on its neighboring loops were obtained. - Abstract: The pressurized water reactor (PWR) with multiple loops may have abnormal working conditions with coolant pumps out of running in some loops. In this paper, a computational fluid dynamics (CFD) numerical study of the four-loop VVER-1000 PWR pressure vessel model was presented. Numerical simulations of the thermohydrodynamic characteristics in the pressure vessel were carried out at different inlet conditions with four and three loops running, respectively. At normal stead-state condition (four-loop running), different parameters were obtained for the full fluid domain, including pressure losses across different parts, pressure, velocity and temperature distributions in the reactor pressure vessel (RPV) and mass flow distribution of the coolant at the inlet of reactor core. The obtained results for pressure losses matched with the experimental reference values of the VVER-1000 PWR at Tianwan nuclear power plant (NPP). For most fuel assemblies (FAs), the inlet flow rates presented a symmetrical distribution about the center under full-loop operation conditions, which accorded with the practical distribution. These results indicate that it is now possible to study the dynamic transition process between different asymmetric operation conditions in a multi-loop PWR using the established CFD method.

Evaluation of Rankine cycle air conditioning system hardware by computer simulation

Science.gov (United States)

Healey, H. M.; Clark, D.

1978-01-01

A computer program for simulating the performance of a variety of solar powered Rankine cycle air conditioning system components (RCACS) has been developed. The computer program models actual equipment by developing performance maps from manufacturers data and is capable of simulating off-design operation of the RCACS components. The program designed to be a subroutine of the Marshall Space Flight Center (MSFC) Solar Energy System Analysis Computer Program 'SOLRAD', is a complete package suitable for use by an occasional computer user in developing performance maps of heating, ventilation and air conditioning components.

Mechanical measurement of hydrogen bonded host-guest systems under non-equilibrium, near-physiological conditions.

Science.gov (United States)

Naranjo, Teresa; Cerrón, Fernando; Nieto-Ortega, Belén; Latorre, Alfonso; Somoza, Álvaro; Ibarra, Borja; Pérez, Emilio M

2017-09-01

Decades after the birth of supramolecular chemistry, there are many techniques to measure noncovalent interactions, such as hydrogen bonding, under equilibrium conditions. As ensembles of molecules rapidly lose coherence, we cannot extrapolate bulk data to single-molecule events under non-equilibrium conditions, more relevant to the dynamics of biological systems. We present a new method that exploits the high force resolution of optical tweezers to measure at the single molecule level the mechanical strength of a hydrogen bonded host-guest pair out of equilibrium and under near-physiological conditions. We utilize a DNA reporter to unambiguously isolate single binding events. The Hamilton receptor-cyanuric acid host-guest system is used as a test bed. The force required to dissociate the host-guest system is ∼17 pN and increases with the pulling rate as expected for a system under non-equilibrium conditions. Blocking one of the hydrogen bonding sites results in a significant decrease of the force-to-break by 1-2 pN, pointing out the ability of the method to resolve subtle changes in the mechanical strength of the binding due to the individual H-bonding components. We believe the method will prove to be a versatile tool to address important questions in supramolecular chemistry.

A physiological model for the investigation of esophageal motility in healthy and pathologic conditions.

Science.gov (United States)

Carniel, Emanuele Luigi; Frigo, Alessandro; Costantini, Mario; Giuliani, Tommaso; Nicoletti, Loredana; Merigliano, Stefano; Natali, Arturo N

2016-07-15

Recent technological advances in esophageal manometry allowed the definition of new classification methods for the diagnosis of disorders of esophageal motility and the implementation of innovative computational tools for the autonomic, reliable and unbiased detection of different disorders. Computational models can be developed aiming to interpret the mechanical behavior and functionality of the gastrointestinal tract and to summarize the results from clinical measurements, as high-resolution manometry pressure plots, into model parameters. A physiological model was here developed to interpret data from esophageal high-resolution manometry. Such model accounts for parameters related to specific physiological properties of the biological structures involved in the peristaltic mechanism. The identification of model parameters was performed by minimizing the discrepancy between clinical data from high-resolution manometry and model results. Clinical data were collected from both healthy volunteers (n = 35) and patients with different motor disorders, such as achalasia patterns 1 (n = 13), 2 (n = 20) and 3 (n = 5), distal esophageal spasm (n = 69), esophago-gastric junction outflow obstruction (n = 25), nutcracker esophagus (n = 11) and normal motility (n = 42). The physiological model that was formulated in this work can properly explain high-resolution manometry data, as confirmed by the evaluation of the coefficient of determination R 2  = 0.83 - 0.96. The study finally led to identify the statistical distributions of model parameters for each healthy or pathologic conditions considered, addressing the applicability of the achieved results for the implementation of autonomic diagnosis procedures to support the medical staff during the traditional diagnostic process. © IMechE 2016.

Flow behavior of Daqing waxy crude oil under simulated pipelining conditions

Energy Technology Data Exchange (ETDEWEB)

Ding, Jianlin [China University of Petroleum, Beijing (China); PetroChina Company Ltd. (China); Zhang, Jinjun; Li, Hongying; Zhang, Fan; Yang, Xiaojing [China University of Petroleum, Beijing (China)

2005-07-01

Daqing oil field is the largest oil field in China. This crude oil is a typical waxy crude oil, with a wax content of 26% and a gel point of 32 deg C. Flow behaviors of waxy crude oils at temperatures near the gel point/pour point are vital for both pipeline hydraulic calculation and evaluation on restartability of a shutdown pipeline. In this study, experimental simulation was conducted by using a stirred vessel with the energy dissipation of viscous flow as the shear simulation parameter. The viscosity, gel point, yield stress and thixotropy were measured by sampling from the simulation vessel. The viscosity under simulated pipelining condition was found less than that measured under quiescent cooling condition. The gel point decreased with decreasing temperature of sampling, i.e. the end temperature of the dynamic cooling process. At sampling temperatures above 35 deg C, that is 3 deg C above the gel point measured under quiescent cooling condition, both the yield stresses and the thixotropic parameters showed little dependence on the shear history. However, at lower sampling temperatures, remarkable shear history dependence was found. Empirical correlations were developed between the yield stress and the sampling temperature as well as the measurement temperature, and between the thixotropic parameters and the sampling temperature. (author)

Comparative study of Newtonian physiological blood flow through normal and stenosed carotid artery

Science.gov (United States)

Rahman, Mohammad Matiur; Hossain, Md. Anwar; Mamun, Khairuzzaman; Akhter, Most. Nasrin

2017-06-01

A numerical simulation is performed to investigate Newtonian physiological flows behavior on three dimensional idealized carotid artery (CA) and single stenosed (75% by area) carotid artery(SCA). The wall vessel is set as rigid during simulation. Bifurcated blood vessel are simulated by using three-dimensional flow analysis. Physiological and parabolic velocity profiles are set out to fix the conditions of inlet boundaries of artery. In other hand, physiological waveform is an important part of compilation and it is successfully done by utilization of Fourier series having sixteen harmonics. The investigation has a Reynolds number range of 94 to 1120. Low Reynolds number k — ω model has been used as governing equation. The investigation has been carried out to characterize the flow behavior of blood in two geometry, namely, (i) Normal carotid artery (CA) and (ii) Stenosed carotid artery (SCA). The Newtonian model has been used to study the physics of fluid. The findings of the two models are thoroughly compared in order to observe there behavioral sequence of flows. The numerical results were presented in terms of velocity, pressure, wall shear stress distributions and cross sectional velocities as well as the streamlines contour. Stenosis disturbs the normal pattern of blood flow through the artery as reduced area. At stenosis region velocity and peak Reynolds number rapidly increase and Reynolds number reach transitional and turbulent region. These flow fluctuation and turbulence have bad effect to the blood vessel which makes to accelerate the progress of stenosis.

Positive impact of bio-stimulators on growth and physiological activity of willow in climate change conditions

Science.gov (United States)

Piotrowski, Krzysztof; Romanowska-Duda, Zdzisława

2018-04-01

The aim of this research was to evaluate the physiological activity and growth of willow (Salix viminalis L.) plants cultivated under the conditions of adverse temperature and soil moisture content, and to assess the effect of the foliar application of Biojodis (1.0%) and Asahi SL (0.03%) bio-stimulators, or a mixture of Microcistis aeruginosa MKR 0105 and Anabaena PCC 7120 cyanobacteria under such changing growth conditions. The obtained results showed different reactions to the applied constant or periodically changed temperature and soil moisture content. The plants which grew at periodically changed adverse temperature (from -5 to 40oC) or in scantily (20% m.c.) or excessively (60% m.c.) watered soils, grew slowly, in comparison with those growing at 20oC and in optimally moistened soil (30% m.c.). Foliar application of Biojodis and Asahi SL cyanobacteria increased the growth of willow at optimal and adverse temperature or in scantily and excessively moistened soil. The changes in plant growth were associated with the changes in electrolyte leakage, activity of acid or alkaline phosphatases, RNase, index of chlorophyll content in leaves and gas exchange. The above indicates that the foliar application of the studied cyanobacteria and bio-stimulators partly alleviates the harmful impact of adverse temperature and water stress on growth and physiological activity of willow plants

The Baltimore Therapeutic Equipment work simulator: biomechanical and physiological norms for three attachments in healthy men.

Science.gov (United States)

Bhambhani, Y; Esmail, S; Brintnell, S

1994-01-01

The Baltimore Therapeutic Equipment (BTE) work simulator is routinely used by occupational therapists in functional capacity evaluation. Currently, there is a lack of normative data for various attachments on this instrument. The purposes of this study were to (a) establish norms for the biomechanical and physiological responses during three tasks on the BTE work simulator, namely, wheel-turn, push-pull, and overhead-reach; (b) compare these responses during the three tasks, and (c) examine the interrelationships of these responses during the tasks. Twenty healthy men completed five testing sessions: (a) task familiarization on the BTE work simulator to identify the work intensity, which was perceived as hard on the Borg scale; (b) an incremental arm ergometer exercise test to determine their peak oxygen uptake (pVO2) and peak heart rate (pHR); and (c) one of the three tasks on the BTE work simulator for 4 min in each of the next three sessions. Analysis of variance indicated that torque, work, and power during the overhead-reach were significantly higher (p = .000) compared with the wheel-turn and push-pull tasks. However, no significant differences (p > .05) were observed among the tasks for the VO2 and HR, which were approximately 50% and 70% of pVO2 and pHR respectively. Although there was a significant relationship (p batteries, and that there is no consistent relationship between cardiorespiratory fitness and performance of various tasks on the BTE work simulator.

Analysis of three-phase equilibrium conditions for methane hydrate by isometric-isothermal molecular dynamics simulations

Science.gov (United States)

Yuhara, Daisuke; Brumby, Paul E.; Wu, David T.; Sum, Amadeu K.; Yasuoka, Kenji

2018-05-01

To develop prediction methods of three-phase equilibrium (coexistence) conditions of methane hydrate by molecular simulations, we examined the use of NVT (isometric-isothermal) molecular dynamics (MD) simulations. NVT MD simulations of coexisting solid hydrate, liquid water, and vapor methane phases were performed at four different temperatures, namely, 285, 290, 295, and 300 K. NVT simulations do not require complex pressure control schemes in multi-phase systems, and the growth or dissociation of the hydrate phase can lead to significant pressure changes in the approach toward equilibrium conditions. We found that the calculated equilibrium pressures tended to be higher than those reported by previous NPT (isobaric-isothermal) simulation studies using the same water model. The deviations of equilibrium conditions from previous simulation studies are mainly attributable to the employed calculation methods of pressure and Lennard-Jones interactions. We monitored the pressure in the methane phase, far from the interfaces with other phases, and confirmed that it was higher than the total pressure of the system calculated by previous studies. This fact clearly highlights the difficulties associated with the pressure calculation and control for multi-phase systems. The treatment of Lennard-Jones interactions without tail corrections in MD simulations also contributes to the overestimation of equilibrium pressure. Although improvements are still required to obtain accurate equilibrium conditions, NVT MD simulations exhibit potential for the prediction of equilibrium conditions of multi-phase systems.

Analysis of three-phase equilibrium conditions for methane hydrate by isometric-isothermal molecular dynamics simulations.

Science.gov (United States)

Yuhara, Daisuke; Brumby, Paul E; Wu, David T; Sum, Amadeu K; Yasuoka, Kenji

2018-05-14

To develop prediction methods of three-phase equilibrium (coexistence) conditions of methane hydrate by molecular simulations, we examined the use of NVT (isometric-isothermal) molecular dynamics (MD) simulations. NVT MD simulations of coexisting solid hydrate, liquid water, and vapor methane phases were performed at four different temperatures, namely, 285, 290, 295, and 300 K. NVT simulations do not require complex pressure control schemes in multi-phase systems, and the growth or dissociation of the hydrate phase can lead to significant pressure changes in the approach toward equilibrium conditions. We found that the calculated equilibrium pressures tended to be higher than those reported by previous NPT (isobaric-isothermal) simulation studies using the same water model. The deviations of equilibrium conditions from previous simulation studies are mainly attributable to the employed calculation methods of pressure and Lennard-Jones interactions. We monitored the pressure in the methane phase, far from the interfaces with other phases, and confirmed that it was higher than the total pressure of the system calculated by previous studies. This fact clearly highlights the difficulties associated with the pressure calculation and control for multi-phase systems. The treatment of Lennard-Jones interactions without tail corrections in MD simulations also contributes to the overestimation of equilibrium pressure. Although improvements are still required to obtain accurate equilibrium conditions, NVT MD simulations exhibit potential for the prediction of equilibrium conditions of multi-phase systems.

Corrosion of pure OFHC-copper in simulated repository conditions

International Nuclear Information System (INIS)

Aaltonen, P.

1990-04-01

The research program 'Corrosion of pure OFHC-copper in simulated repository conditions' was planned to provide an experimental evaluation with respect to the theoretical calculations and forecasts made for the corrosion behaviour of pure copper in bentonite groundwater environments at temperatures between 20-80 deg C. The aim of this study in the first place is to evaluate the effects of groundwater composition, bentonite and temperature on the equilibrium and possible corrosion reactions between pure copper and the simulated repository environment. The progress report includes the results obtained after 36 months exposure time

Evaluation of type II thyroplasty on phonatory physiology in an excised canine larynx model

Science.gov (United States)

Devine, Erin E.; Hoffman, Matthew R.; McCulloch, Timothy M.; Jiang, Jack J.

2016-01-01

Objective Type II thyroplasty is an alternative treatment for spasmodic dysphonia, addressing hyperadduction by incising and lateralizing the thyroid cartilage. We quantified the effect of lateralization width on phonatory physiology using excised canine larynges. Methods Normal closure, hyperadduction, and type II thyroplasty (lateralized up to 5mm at 1mm increments with hyperadducted arytenoids) were simulated in excised larynges (N=7). Aerodynamic, acoustic, and videokymographic data were recorded at three subglottal pressures relative to phonation threshold pressure (PTP). One-way repeated measures ANOVA assessed effect of condition on aerodynamic parameters. Random intercepts linear mixed effects models assessed effects of condition and subglottal pressure on acoustic and videokymographic parameters. Results PTP differed across conditions (p<0.001). Condition affected percent shimmer (p<0.005) but not percent jitter. Both pressure (p<0.03) and condition (p<0.001) affected fundamental frequency. Pressure affected vibratory amplitude (p<0.05) and intra-fold phase difference (p<0.05). Condition affected phase difference between the vocal folds (p<0.001). Conclusions Hyperadduction increased PTP and worsened perturbation compared to normal, with near normal physiology restored with 1mm lateralization. Further lateralization deteriorated voice quality and increased PTP. Acoustic and videokymographic results indicate that normal physiologic relationships between subglottal pressure and vibration are preserved at optimal lateralization width, but then degrade with further lateralization. The 1mm optimal width observed here is due to the small canine larynx size. Future human trials would likely demonstrate a greater optimal width, with patient-specific value potentially determined based on larynx size and symptom severity. PMID:27223665

Applying Dynamic Energy Budget (DEB) theory to simulate growth and bio-energetics of blue mussels under low seston conditions

Science.gov (United States)

Rosland, R.; Strand, Ø.; Alunno-Bruscia, M.; Bacher, C.; Strohmeier, T.

2009-08-01

A Dynamic Energy Budget (DEB) model for simulation of growth and bioenergetics of blue mussels ( Mytilus edulis) has been tested in three low seston sites in southern Norway. The observations comprise four datasets from laboratory experiments (physiological and biometrical mussel data) and three datasets from in situ growth experiments (biometrical mussel data). Additional in situ data from commercial farms in southern Norway were used for estimation of biometrical relationships in the mussels. Three DEB parameters (shape coefficient, half saturation coefficient, and somatic maintenance rate coefficient) were estimated from experimental data, and the estimated parameters were complemented with parameter values from literature to establish a basic parameter set. Model simulations based on the basic parameter set and site specific environmental forcing matched fairly well with observations, but the model was not successful in simulating growth at the extreme low seston regimes in the laboratory experiments in which the long period of negative growth caused negative reproductive mass. Sensitivity analysis indicated that the model was moderately sensitive to changes in the parameter and initial conditions. The results show the robust properties of the DEB model as it manages to simulate mussel growth in several independent datasets from a common basic parameter set. However, the results also demonstrate limitations of Chl a as a food proxy for blue mussels and limitations of the DEB model to simulate long term starvation. Future work should aim at establishing better food proxies and improving the model formulations of the processes involved in food ingestion and assimilation. The current DEB model should also be elaborated to allow shrinking in the structural tissue in order to produce more realistic growth simulations during long periods of starvation.

Effect of Salicylic Acid on the Growth and Physiological Characteristics of Maize under Stress Conditions

International Nuclear Information System (INIS)

Manzoor, K.; Ilyas, N.; Batool, N.; Arshad, M.; Ahmad, B.

2015-01-01

Salicylic acid (SA) is a naturally occurring signaling molecule and growth regulator that enhances plant growth particularly in stress conditions. The present study was planned to evaluate the effects of different levels of SA on maize growth under drought and salt stress conditions. An experiment was conducted to test the morphological, physiological and biochemical changes in two cultivar of maize D-1184 and TG-8250. Varying levels of salicylic acid, i.e. 5mM, 10mM and 15mM were applied through foliar method. Exogenous applications of salicylic acid were done after 20 days of germination of the maize plants. Salicylic acid significantly affects root and shoot dry matter under drought and salt stress. Foliar application of SA significantly increased proline concentration (11 percentage and 12 percentage), amino acid accumulation (25 percentage and 18 percentage), relative water (17 percentage and 14 percentage) and Chlorophyll content. Overall, it can be concluded that SA at lower concentration is effective to minimize the effect of stress conditions. Maize cultivar TG-8250 showed better tolerance under drought and salt stress condition as compared to D-1184 cultivar. (author)

Cholesterol as a modifying agent of the neurovascular unit structure and function under physiological and pathological conditions.

Science.gov (United States)

Czuba, Ewelina; Steliga, Aleksandra; Lietzau, Grażyna; Kowiański, Przemysław

2017-08-01

The brain, demanding constant level of cholesterol, precisely controls its synthesis and homeostasis. The brain cholesterol pool is almost completely separated from the rest of the body by the functional blood-brain barrier (BBB). Only a part of cholesterol pool can be exchanged with the blood circulation in the form of the oxysterol metabolites such, as 27-hydroxycholesterol (27-OHC) and 24S-hydroxycholesterol (24S-OHC). Not only neurons but also blood vessels and neuroglia, constituting neurovascular unit (NVU), are crucial for the brain cholesterol metabolism and undergo precise regulation by numerous modulators, metabolites and signal molecules. In physiological conditions maintaining the optimal cholesterol concentration is important for the energetic metabolism, composition of cell membranes and myelination. However, a growing body of evidence indicates the consequences of the cholesterol homeostasis dysregulation in several pathophysiological processes. There is a causal relationship between hypercholesterolemia and 1) development of type 2 diabetes due to long-term high-fat diet consumption, 2) significance of the oxidative stress consequences for cerebral amyloid angiopathy and neurodegenerative diseases, 3) insulin resistance on progression of the neurodegenerative brain diseases. In this review, we summarize the current state of knowledge concerning the cholesterol influence upon functioning of the NVU under physiological and pathological conditions.

[Autonomic regulation at emotional stress under hypoxic conditions in the elderly with physiological and accelerated aging: effect of hypoxic training].

Science.gov (United States)

Os'mak, E D; Asanov, É O

2014-01-01

The effect of hypoxic training on autonomic regulation in psycho-emotional stress conditions in hypoxic conditions in older people with physiological (25 people) and accelerated (28 people) aging respiratory system. It is shown that hypoxic training leads to an increase in vagal activity indicators (HF) and reduced simpatovagal index (LF/HF), have a normalizing effect on the autonomic balance during stress loads in older people with different types of aging respiratory system.

Quantification of discreteness effects in cosmological N-body simulations: Initial conditions

International Nuclear Information System (INIS)

Joyce, M.; Marcos, B.

2007-01-01

The relation between the results of cosmological N-body simulations, and the continuum theoretical models they simulate, is currently not understood in a way which allows a quantification of N dependent effects. In this first of a series of papers on this issue, we consider the quantification of such effects in the initial conditions of such simulations. A general formalism developed in [A. Gabrielli, Phys. Rev. E 70, 066131 (2004).] allows us to write down an exact expression for the power spectrum of the point distributions generated by the standard algorithm for generating such initial conditions. Expanded perturbatively in the amplitude of the input (i.e. theoretical, continuum) power spectrum, we obtain at linear order the input power spectrum, plus two terms which arise from discreteness and contribute at large wave numbers. For cosmological type power spectra, one obtains as expected, the input spectrum for wave numbers k smaller than that characteristic of the discreteness. The comparison of real space correlation properties is more subtle because the discreteness corrections are not as strongly localized in real space. For cosmological type spectra the theoretical mass variance in spheres and two-point correlation function are well approximated above a finite distance. For typical initial amplitudes this distance is a few times the interparticle distance, but it diverges as this amplitude (or, equivalently, the initial redshift of the cosmological simulation) goes to zero, at fixed particle density. We discuss briefly the physical significance of these discreteness terms in the initial conditions, in particular, with respect to the definition of the continuum limit of N-body simulations

Physiological responses to variations in grazing and light conditions in native and invasive fucoids.

Science.gov (United States)

Olabarria, Celia; Arenas, Francisco; Fernández, Ángela; Troncoso, Jesús S; Martínez, Brezo

2018-08-01

Poor physiological acclimatization to climate change has led to shifts in the distributional ranges of various species and to biodiversity loss. However, evidence also suggests the relevance of non-climatic physical factors, such as light, and biotic factors, which may act in interactive or additive way. We used a mechanistic approach to evaluate the ecophysiological responses of four seaweed species (three dominant intertidal fucoids, Fucus serratus, Ascophyllum nodosum, Bifurcaria bifurcata, and the invasive Sargassum muticum) to different conditions of grazing, light irradiance and ultraviolet (UV) radiation. We performed a large-scale mesocosm experiment with a total of 800 individual thalli of macroalgae. The factorial experimental design included major algal traits, photoacclimation, nutrient stoichiometry and chemical defence as response variables. Few significant effects of the factors acting alone or in combination were observed, suggesting a good capacity for acclimatization in all four species. The significant effects were generally additive and there were no potentially deleterious synergistic effects between factors. Fucus serratus, a species currently undergoing a drastic contraction of its southern distribution limit in Europe, was the most strongly affected species, showing overall lower photosynthetic efficiency than the other species. The growth rate of F. serratus decreased when UV radiation was filtered out, but only in the presence of grazers. Moreover, more individuals of this species tended to reach maturity in the absence of grazers, and the nitrogen content of tissues decreased under full-spectrum light. Only the phlorotannin content of tissues of B. bifurcata and of exudates of A. nodosum, both slow-growing species, were positively affected by respectively removal of UVB radiation and the presence of grazers. The findings for S. muticum, a well-established invasive seaweed across European coasts, suggested similar physiological response of

Helicobacter pylori colonization critically depends on postprandial gastric conditions

Science.gov (United States)

Bücker, Roland; Azevedo-Vethacke, Marina; Groll, Claudia; Garten, Désirée; Josenhans, Christine; Suerbaum, Sebastian; Schreiber, Sören

2012-01-01

The risk of Helicobacter pylori infection is highest in childhood, but the colonization process of the stomach mucosa is poorly understood. We used anesthetized Mongolian gerbils to study the initial stages of H. pylori colonization. Prandial and postprandial gastric conditions characteristic of humans of different ages were simulated. The fraction of bacteria that reached the deep mucus layer varied strongly with the modelled postprandial conditions. Colonization success was weak with fast gastric reacidification typical of adults. The efficiency of deep mucus entry was also low with a slow pH decrease as seen in pH profiles simulating the situation in babies. Initial colonization was most efficient under conditions simulating the postprandial reacidification and pepsin activation profiles in young children. In conclusion, initial H. pylori colonization depends on age-related gastric physiology, providing evidence from an in vivo infection model that suggests an explanation why the bacterium is predominantly acquired in early childhood. PMID:23251780

Modeling of hydrologic conditions and solute movement in processed oil shale waste embankments under simulated climatic conditions

International Nuclear Information System (INIS)

Reeves, T.L.; Turner, J.P.; Hasfurther, V.R.; Skinner, Q.D.

1992-06-01

The scope of this program is to study interacting hydrologic, geotechnical, and chemical factors affecting the behavior and disposal of combusted processed oil shale. The research combines bench-scale testing with large scale research sufficient to describe commercial scale embankment behavior. The large scale approach was accomplished by establishing five lysimeters, each 7.3 x 3.0 x 3.0 m deep, filled with processed oil shale that has been retorted and combusted by the Lurgi-Ruhrgas (Lurgi) process. Approximately 400 tons of Lurgi processed oil shale waste was provided by RBOSC to carry out this study. Research objectives were designed to evaluate hydrologic, geotechnical, and chemical properties and conditions which would affect the design and performance of large-scale embankments. The objectives of this research are: assess the unsaturated movement and redistribution of water and the development of potential saturated zones and drainage in disposed processed oil shale under natural and simulated climatic conditions; assess the unsaturated movement of solubles and major chemical constituents in disposed processed oil shale under natural and simulated climatic conditions; assess the physical and constitutive properties of the processed oil shale and determine potential changes in these properties caused by disposal and weathering by natural and simulated climatic conditions; assess the use of previously developed computer model(s) to describe the infiltration, unsaturated movement, redistribution, and drainage of water in disposed processed oil shale; evaluate the stability of field scale processed oil shale solid waste embankments using computer models

Biochemical and physiological characterization of three rice cultivars under different daytime temperature conditions

Directory of Open Access Journals (Sweden)

Alefsi David Sanchez-Reinoso

2014-12-01

Full Text Available Heat stress due to high daytime temperatures is one of the main limiting factors in rice (Oryza sativa L. yield in Colombia. Thus, the objective of the present research was to analyze the effect of three different daytime temperatures (25, 35, and 40 °C on the physiological responses of three Colombian rice cultivars (F60, F733, and F473, thereby contributing to the knowledge of rice acclimation mechanisms. For 10 d, eight plants of each of the three cultivars were subjected daily to 5 h periods of 35 and 40 °C. The control treatment corresponded to normal growth conditions (25 °C. Thermal stress was assessed based on a series of physiological and biochemical parameters. The 35 °C treatment produced photosynthetic and respiratory differences in all three cultivars. At 40 °C, 'F60' displayed the lowest photosynthetic rate and the highest respiratory rate. Although this cultivar experienced particularly strong electrolyte leakage and changes in proline when subjected to the high-temperature treatments, similar trends were observed in 'F733' and 'F473'. At 40 °C, the concentration of malondialdehyde (MDA was lower in 'F473' than in the other cultivars. These results may explain the poor agronomic performance of 'F60' in the field under daytime heat stress. The methodologies employed in the present work may be useful in Colombian rice breeding programs, particularly for the selection of heat-tolerant breeding stocks.

Pyrite oxidation under simulated acid rain weathering conditions.

Science.gov (United States)

Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

2017-09-01

We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

Lifting simulation of an offshore supply vessel considering various operating conditions

Directory of Open Access Journals (Sweden)

Dong-Hoon Jeong

2016-06-01

Full Text Available Recently, an offshore support vessel is being widely used to install an offshore structure such as a subsea equipment which is laid on its deck. The lifting operation which is one of the installation operations includes lifting off, lifting in the air, splash zone crossing, deep submerging, and finally landing of the structure with an offshore support vessel crane. There are some major considerations during this operation. Especially, when lifting off the structure, if operating conditions such as ocean environmental loads and hoisting (or lowering speed are bad, the excess of tension of wire ropes of the crane and the collision between the offshore support vessel and the structure can be occurred due to the relative motion between them. To solve this problem, this study performs the lifting simulation while the offshore support vessel installs the structure. The simulation includes the calculation of dynamic responses of the offshore support vessel and the equipment, including the wire tension and the collision detection. To check the applicability of the simulation, it is applied to some lifting steps by varying operating conditions. As a result, it is confirmed that the conditions affect the operability of those steps.

Survival, physical and physiological changes of Taenia hydatigena eggs under different conditions of water stress.

Science.gov (United States)

Sánchez Thevenet, Paula; Alvarez, Hector Manuel; Basualdo, Juan Angel

2017-06-01

Taenia hydatigena eggs were investigated for morphological and physiological changes under water stress conditions. Fresh eggs were exposed at 31%, 47% and 89% of relative humidity (RH), and survival, size and ultrastructural changes were accounted up to 365 days of exposition. The article shows how each RH environment affects the vitality of the eggs. Results of this study suggest that T. hydatigena eggs have mechanisms to withstand water stress, indicating that the eggs clustering improves protection against desiccation, and that endogenous metabolism using triacylglycerols play an important role in the maintenance of embryo vitality under low, medium and high relative humidity conditions. This contributes to understanding the water stress resistance mechanism in eggs belonging to Taeniidae family. The findings shown herein have provided a basis to better comprehend basic biology and epidemiology of the cysticercosis caused by T. hydatigena. Copyright © 2017 Elsevier Inc. All rights reserved.

Activity and stability of a complex bacterial soil community under simulated Martian conditions

Science.gov (United States)

Hansen, Aviaja Anna; Merrison, Jonathan; Nørnberg, Per; Aagaard Lomstein, Bente; Finster, Kai

2005-04-01

A simulation experiment with a complex bacterial soil community in a Mars simulation chamber was performed to determine the effect of Martian conditions on community activity, stability and survival. At three different depths in the soil core short-term effects of Martian conditions with and without ultraviolet (UV) exposure corresponding to 8 Martian Sol were compared. Community metabolic activities and functional diversity, measured as glucose respiration and versatility in substrate utilization, respectively, decreased after UV exposure, whereas they remained unaffected by Martian conditions without UV exposure. In contrast, the numbers of culturable bacteria and the genetic diversity were unaffected by the simulated Martian conditions both with and without UV exposure. The genetic diversity of the soil community and of the colonies grown on agar plates were evaluated by denaturant gradient gel electrophoresis (DGGE) on DNA extracts. Desiccation of the soil prior to experimentation affected the functional diversity by decreasing the versatility in substrate utilization. The natural dominance of endospores and Gram-positive bacteria in the investigated Mars-analogue soil may explain the limited effect of the Mars incubations on the survival and community structure. Our results suggest that UV radiation and desiccation are major selecting factors on bacterial functional diversity in terrestrial bacterial communities incubated under simulated Martian conditions. Furthermore, these results suggest that forward contamination of Mars is a matter of great concern in future space missions.

Toward the Computational Representation of Individual Cultural, Cognitive, and Physiological State: The Sensor Shooter Simulation; TOPICAL

International Nuclear Information System (INIS)

RAYBOURN, ELAINE M.; FORSYTHE, JAMES C.

2001-01-01

This report documents an exploratory FY 00 LDRD project that sought to demonstrate the first steps toward a realistic computational representation of the variability encountered in individual human behavior. Realism, as conceptualized in this project, required that the human representation address the underlying psychological, cultural, physiological, and environmental stressors. The present report outlines the researchers' approach to representing cognitive, cultural, and physiological variability of an individual in an ambiguous situation while faced with a high-consequence decision that would greatly impact subsequent events. The present project was framed around a sensor-shooter scenario as a soldier interacts with an unexpected target (two young Iraqi girls). A software model of the ''Sensor Shooter'' scenario from Desert Storm was developed in which the framework consisted of a computational instantiation of Recognition Primed Decision Making in the context of a Naturalistic Decision Making model[1]. Recognition Primed Decision Making was augmented with an underlying foundation based on our current understanding of human neurophysiology and its relationship to human cognitive processes. While the Gulf War scenario that constitutes the framework for the Sensor Shooter prototype is highly specific, the human decision architecture and the subsequent simulation are applicable to other problems similar in concept, intensity, and degree of uncertainty. The goal was to provide initial steps toward a computational representation of human variability in cultural, cognitive, and physiological state in order to attain a better understanding of the full depth of human decision-making processes in the context of ambiguity, novelty, and heightened arousal

Successes and Challenges of Interprofessional Physiologic Birth and Obstetric Emergency Simulations in a Nurse-Midwifery Education Program.

Science.gov (United States)

Shaw-Battista, Jenna; Belew, Cynthia; Anderson, Deborah; van Schaik, Sandrijn

2015-01-01

This article describes childbirth simulation design and implementation within the nurse-midwifery education program at the University of California, San Francisco. Nurse-midwife and obstetrician faculty coordinators were supported by faculty from multiple professions and specialties in curriculum review and simulation development and implementation. The primary goal of the resulting technology-enhanced simulations of normal physiologic birth and obstetric emergencies was to assist learners' development of interprofessional competencies related to communication, teamwork, and patient-centered care. Trainees included nurse-midwifery students; residents in obstetrics, pediatrics, and family medicine; medical students; and advanced practice nursing students in pediatrics. The diversity of participant types and learning levels provided benefits and presented challenges to effective scenario-based simulation design among numerous other theoretical and logistical considerations. This project revealed practical solutions informed by emerging health sciences and education research literature, faculty experience, and formal course evaluations by learners. Best practices in simulation development and implementation were incorporated, including curriculum revision grounded in needs assessment, case- and event-based clinical scenarios, optimization of fidelity, and ample time for participant debriefing. Adequate preparation and attention to detail increased the immersive experience and benefits of simulation. Suggestions for fidelity enhancement are provided with examples of simulation scenarios, a timeline for preparations, and discussion topics to facilitate meaningful learning by maternity and newborn care providers and trainees in clinical and academic settings. Pre- and postsimulation measurements of knowledge, skills, and attitudes are ongoing and not reported. This article is part of a special series of articles that address midwifery innovations in clinical practice

Effects of earthquake rupture shallowness and local soil conditions on simulated ground motions

International Nuclear Information System (INIS)

Apsel, Randy J.; Hadley, David M.; Hart, Robert S.

1983-03-01

The paucity of strong ground motion data in the Eastern U.S. (EUS), combined with well recognized differences in earthquake source depths and wave propagation characteristics between Eastern and Western U.S. (WUS) suggests that simulation studies will play a key role in assessing earthquake hazard in the East. This report summarizes an extensive simulation study of 5460 components of ground motion representing a model parameter study for magnitude, distance, source orientation, source depth and near-surface site conditions for a generic EUS crustal model. The simulation methodology represents a hybrid approach to modeling strong ground motion. Wave propagation is modeled with an efficient frequency-wavenumber integration algorithm. The source time function used for each grid element of a modeled fault is empirical, scaled from near-field accelerograms. This study finds that each model parameter has a significant influence on both the shape and amplitude of the simulated response spectra. The combined effect of all parameters predicts a dispersion of response spectral values that is consistent with strong ground motion observations. This study provides guidelines for scaling WUS data from shallow earthquakes to the source depth conditions more typical in the EUS. The modeled site conditions range from very soft soil to hard rock. To the extent that these general site conditions model a specific site, the simulated response spectral information can be used to either correct spectra to a site-specific environment or used to compare expected ground motions at different sites. (author)

Effects of Dietary Nitrate Supplementation on Physiological Responses, Cognitive Function, and Exercise Performance at Moderate and Very-High Simulated Altitude

Directory of Open Access Journals (Sweden)

Oliver M. Shannon

2017-06-01

Full Text Available Purpose: Nitric oxide (NO bioavailability is reduced during acute altitude exposure, contributing toward the decline in physiological and cognitive function in this environment. This study evaluated the effects of nitrate (NO3− supplementation on NO bioavailability, physiological and cognitive function, and exercise performance at moderate and very-high simulated altitude.Methods:Ten males (mean (SD: V˙O2max: 60.9 (10.1 ml·kg−1·min−1 rested and performed exercise twice at moderate (~14.0% O2; ~3,000 m and twice at very-high (~11.7% O2; ~4,300 m simulated altitude. Participants ingested either 140 ml concentrated NO3−-rich (BRJ; ~12.5 mmol NO3− or NO3−-deplete (PLA; 0.01 mmol NO3− beetroot juice 2 h before each trial. Participants rested for 45 min in normobaric hypoxia prior to completing an exercise task. Exercise comprised a 45 min walk at 30% V˙O2max and a 3 km time-trial (TT, both conducted on a treadmill at a 10% gradient whilst carrying a 10 kg backpack to simulate altitude hiking. Plasma nitrite concentration ([NO2−], peripheral oxygen saturation (SpO2, pulmonary oxygen uptake (V˙O2, muscle and cerebral oxygenation, and cognitive function were measured throughout.Results: Pre-exercise plasma [NO2−] was significantly elevated in BRJ compared with PLA (p = 0.001. Pulmonary V˙O2 was reduced (p = 0.020, and SpO2 was elevated (p = 0.005 during steady-state exercise in BRJ compared with PLA, with similar effects at both altitudes. BRJ supplementation enhanced 3 km TT performance relative to PLA by 3.8% [1,653.9 (261.3 vs. 1718.7 (213.0 s] and 4.2% [1,809.8 (262.0 vs. 1,889.1 (203.9 s] at 3,000 and 4,300 m, respectively (p = 0.019. Oxygenation of the gastrocnemius was elevated during the TT consequent to BRJ (p = 0.011. The number of false alarms during the Rapid Visual Information Processing Task tended to be lower with BRJ compared with PLA prior to altitude exposure (p = 0.056. Performance in all other cognitive tasks

Cellular Responses of the Lichen Circinaria gyrosa in Mars-Like Conditions

Directory of Open Access Journals (Sweden)

Rosa de la Torre Noetzel

2018-03-01

Full Text Available Lichens are extremely resistant organisms that colonize harsh climatic areas, some of them defined as “Mars-analog sites.” There still remain many unsolved questions as to how lichens survive under such extreme conditions. Several studies have been performed to test the resistance of various lichen species under space and in simulated Mars-like conditions. The results led to the proposal that Circinaria gyrosa (Lecanoromycetes, Ascomycota is one of the most durable astrobiological model lichens. However, although C. gyrosa has been exposed to Mars-like environmental conditions while in a latent state, it has not been exposed in its physiologically active mode. We hypothesize that the astrobiological test system “Circinaria gyrosa,” could be able to be physiologically active and to survive under Mars-like conditions in a simulation chamber, based on previous studies performed at dessicated-dormant stage under simulated Mars-like conditions, that showed a complete recover of the PSII activity (Sánchez et al., 2012. Epifluorescence and confocal laser scanning microscopy (CLSM showed that living algal cells were more abundant in samples exposed to niche conditions, which simulated the conditions in micro-fissures and micro-caves close to the surface that have limited scattered or time-dependent light exposure, than in samples exposed to full UV radiation. The medulla was not structurally affected, suggesting that the niche exposure conditions did not disturb the lichen thalli structure and morphology as revealed by field emission scanning electron microscopy (FESEM. In addition, changes in the lichen thalli chemical composition were determined by analytical pyrolysis. The chromatograms resulting from analytical pyrolysis at 500°C revealed that lichen samples exposed to niche conditions and full UV radiation consisted primarily of glycosidic compounds, lipids, and sterols, which are typical constituents of the cell walls. However, specific

Cellular Responses of the Lichen Circinaria gyrosa in Mars-Like Conditions.

Science.gov (United States)

de la Torre Noetzel, Rosa; Miller, Ana Z; de la Rosa, José M; Pacelli, Claudia; Onofri, Silvano; García Sancho, Leopoldo; Cubero, Beatriz; Lorek, Andreas; Wolter, David; de Vera, Jean P

2018-01-01

Lichens are extremely resistant organisms that colonize harsh climatic areas, some of them defined as "Mars-analog sites." There still remain many unsolved questions as to how lichens survive under such extreme conditions. Several studies have been performed to test the resistance of various lichen species under space and in simulated Mars-like conditions. The results led to the proposal that Circinaria gyrosa (Lecanoromycetes, Ascomycota) is one of the most durable astrobiological model lichens. However, although C . gyrosa has been exposed to Mars-like environmental conditions while in a latent state, it has not been exposed in its physiologically active mode. We hypothesize that the astrobiological test system " Circinaria gyrosa ," could be able to be physiologically active and to survive under Mars-like conditions in a simulation chamber, based on previous studies performed at dessicated-dormant stage under simulated Mars-like conditions, that showed a complete recover of the PSII activity (Sánchez et al., 2012). Epifluorescence and confocal laser scanning microscopy (CLSM) showed that living algal cells were more abundant in samples exposed to niche conditions, which simulated the conditions in micro-fissures and micro-caves close to the surface that have limited scattered or time-dependent light exposure, than in samples exposed to full UV radiation. The medulla was not structurally affected, suggesting that the niche exposure conditions did not disturb the lichen thalli structure and morphology as revealed by field emission scanning electron microscopy (FESEM). In addition, changes in the lichen thalli chemical composition were determined by analytical pyrolysis. The chromatograms resulting from analytical pyrolysis at 500°C revealed that lichen samples exposed to niche conditions and full UV radiation consisted primarily of glycosidic compounds, lipids, and sterols, which are typical constituents of the cell walls. However, specific differences could be

Using numeric simulation in an online e-learning environment to teach functional physiological contexts.

Science.gov (United States)

Christ, Andreas; Thews, Oliver

2016-04-01

Mathematical models are suitable to simulate complex biological processes by a set of non-linear differential equations. These simulation models can be used as an e-learning tool in medical education. However, in many cases these mathematical systems have to be treated numerically which is computationally intensive. The aim of the study was to develop a system for numerical simulation to be used in an online e-learning environment. In the software system the simulation is located on the server as a CGI application. The user (student) selects the boundary conditions for the simulation (e.g., properties of a simulated patient) on the browser. With these parameters the simulation on the server is started and the simulation result is re-transferred to the browser. With this system two examples of e-learning units were realized. The first one uses a multi-compartment model of the glucose-insulin control loop for the simulation of the plasma glucose level after a simulated meal or during diabetes (including treatment by subcutaneous insulin application). The second one simulates the ion transport leading to the resting and action potential in nerves. The student can vary parameters systematically to explore the biological behavior of the system. The described system is able to simulate complex biological processes and offers the possibility to use these models in an online e-learning environment. As far as the underlying principles can be described mathematically, this type of system can be applied to a broad spectrum of biomedical or natural scientific topics. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Biogeochemical Reactions Under Simulated Europa Ocean Conditions

Science.gov (United States)

Amashukeli, X.; Connon, S. A.; Gleeson, D. F.; Kowalczyk, R. S.; Pappalardo, R. T.

2007-12-01

Galileo data have demonstrated the probable presence of a liquid water ocean on Europa, and existence of salts and carbon dioxide in the satellite's surface ice (e.g., Carr et al., 1998; McCord et al., 1999, Pappalardo et al., 1999; Kivelson et al., 2000). Subsequently, the discovery of chemical signatures of extinct or extant life in Europa's ocean and on its surface became a distinct possibility. Moreover, understanding of Europa's potential habitability is now one of the major goals of the Europa Orbiter Flagship mission. It is likely, that in the early stages of Europa's ocean formation, moderately alkaline oceanic sulfate-carbonate species and a magnetite-silicate mantel could have participated in low-temperature biogeochemical sulfur, iron and carbon cycles facilitated by primitive organisms (Zolotov and Shock, 2004). If periodic supplies of fresh rock and sulfate-carbonate ions are available in Europa's ocean, then an exciting prospect exists that life may be present in Europa's ocean today. In our laboratory, we began the study of the plausible biogeochemical reactions under conditions appropriate to Europa's ocean using barophilic psychrophilic organisms that thrive under anaerobic conditions. In the near absence of abiotic synthetic pathways due to low Europa's temperatures, the biotic synthesis may present a viable opportunity for the formation of the organic and inorganic compounds under these extreme conditions. This work is independent of assumptions regarding hydrothermal vents at Europa's ocean floor or surface-derived oxidant sources. For our studies, we have fabricated a high-pressure (5,000 psi) reaction vessel that simulates aqueous conditions on Europa. We were also successful at reviving barophilic psychrophilic strains of Shewanella bacterium, which serve as test organisms in this investigation. Currently, facultative barophilic psychrophilic stains of Shewanella are grown in the presence of ferric food source; the strains exhibiting iron

Evaluation of the Virtual Physiology of Exercise Laboratory Program

Science.gov (United States)

Dobson, John L.

2009-01-01

The Virtual Physiology of Exercise Laboratory (VPEL) program was created to simulate the test design, data collection, and analysis phases of selected exercise physiology laboratories. The VPEL program consists of four modules: (1) cardiovascular, (2) maximal O[subscript 2] consumption [Vo[subscript 2max], (3) lactate and ventilatory thresholds,…

Comparison of fabric skins for the simulation of sweating on thermal manikins

Science.gov (United States)

Koelblen, Barbara; Psikuta, Agnes; Bogdan, Anna; Annaheim, Simon; Rossi, René M.

2017-09-01

Sweating is an important thermoregulatory process helping to dissipate heat and, thus, to prevent overheating of the human body. Simulations of human thermo-physiological responses in hot conditions or during exercising are helpful for assessing heat stress; however, realistic sweating simulation and evaporative cooling is needed. To this end, thermal manikins dressed with a tight fabric skin can be used, and the properties of this skin should help human-like sweat evaporation simulation. Four fabrics, i.e., cotton with elastane, polyester, polyamide with elastane, and a skin provided by a manikin manufacturer (Thermetrics) were compared in this study. The moisture management properties of the fabrics have been investigated in basic tests with regard to all phases of sweating relevant for simulating human thermo-physiological responses, namely, onset of sweating, fully developed sweating, and drying. The suitability of the fabrics for standard tests, such as clothing evaporative resistance measurements, was evaluated based on tests corresponding to the middle phase of sweating. Simulations with a head manikin coupled to a thermo-physiological model were performed to evaluate the overall performance of the skins. The results of the study showed that three out of four evaluated fabrics have adequate moisture management properties with regard to the simulation of sweating, which was confirmed in the coupled simulation with the head manikin. The presented tests are helpful for comparing the efficiency of different fabrics to simulate sweat-induced evaporative cooling on thermal manikins.

Artificial Boundary Conditions for the Numerical Simulation of Unsteady Acoustic Waves

National Research Council Canada - National Science Library

Tsynkov, S. V

2003-01-01

We construct non-local artificial boundary conditions (ABCs) for the numerical simulation of genuinely time-dependent acoustic waves that propagate from a compact source in an unbounded unobstructed space...

Didactic tools for understanding respiratory physiology

International Nuclear Information System (INIS)

Kehoe, P Donnelly; Bratovich, C; Perrone, Ms; Castells, L Mendez

2007-01-01

The challenges in Bioengineering are not only the application of engineering knowledge to the measurement of physiological variables, but also the simulation of biological systems. Experience has shown that the physiology of the respiratory system involves a set of concepts that cannot be effectively taught without the help of a group of didactic tools that contribute to the measurement of characteristic specific variables and to the simulation of the system itself. This article describes a series of tools designed to optimize the teaching of the respiratory system, including the use of spirometers and software developed entirely by undergraduate Bioengineering students from Universidad Nacional de Entre Rios (UNER). The impact these resources have caused on the understanding of the topic and how each of them has facilitated the interpretation of the concepts by the students is also discussed

Hemodynamic Simulations in Dialysis Access Fistulae

Science.gov (United States)

McGah, Patrick; Leotta, Daniel; Beach, Kirk; Riley, James; Aliseda, Alberto

2010-11-01

Arteriovenous fistulae are created surgically to provide adequate access for dialysis in patients with End-Stage Renal Disease. It has long been hypothesized that the hemodynamic and mechanical forces (such as wall shear stress, wall stretch, or flow- induced wall vibrations) constitute the primary external influence on the remodeling process. Given that nearly 50% of fistulae fail after one year, understanding fistulae hemodynamics is an important step toward improving patency in the clinic. We perform numerical simulations of the flow in patient-specific models of AV fistulae reconstructed from 3D ultrasound scans with physiologically-realistic boundary conditions also obtained from Doppler ultrasound. Comparison of the flow features in different geometries and configurations e.g. end-to-side vs. side-to-side, with the in vivo longitudinal outcomes will allow us to hypothesize which flow conditions are conducive to fistulae success or failure. The flow inertia and pulsatility in the simulations (mean Re 700, max Re 2000, Wo 4) give rise to complex secondary flows and coherent vortices, further complicating the spatio- temporal variability of the wall pressure and shear stresses. Even in mature fistulae, the anastomotic regions are subjected to non-physiological shear stresses (>10.12pcPa) which may potentially lead to complications.

Comments on ''Use of conditional simulation in nuclear waste site performance assessment'' by Carol Gotway

International Nuclear Information System (INIS)

Downing, D.J.

1993-01-01

This paper discusses Carol Gotway's paper, ''The Use of Conditional Simulation in Nuclear Waste Site Performance Assessment.'' The paper centers on the use of conditional simulation and the use of geostatistical methods to simulate an entire field of values for subsequent use in a complex computer model. The issues of sampling designs for geostatistics, semivariogram estimation and anisotropy, turning bands method for random field generation, and estimation of the comulative distribution function are brought out

Monte Carlo simulation of liquid bridge rupture: Application to lung physiology

Science.gov (United States)

Alencar, Adriano M.; Wolfe, Elie; Buldyrev, Sergey V.

2006-08-01

In the course of certain lung diseases, the surface properties and the amount of fluids coating the airways changes and liquid bridges may form in the small airways blocking the flow of air, impairing gas exchange. During inhalation, these liquid bridges may rupture due to mechanical instability and emit a discrete sound event called pulmonary crackle, which can be heard using a simple stethoscope. We hypothesize that this sound is a result of the acoustical release of energy that had been stored in the surface of liquid bridges prior to its rupture. We develop a lattice gas model capable of describing these phenomena. As a step toward modeling this process, we address a simpler but related problem, that of a liquid bridge between two planar surfaces. This problem has been analytically solved and we use this solution as a validation of the lattice gas model of the liquid bridge rupture. Specifically, we determine the surface free energy and critical stability conditions in a system containing a liquid bridge of volume Ω formed between two parallel planes, separated by a distance 2h , with a contact angle Θ using both Monte Carlo simulation of a lattice gas model and variational calculus based on minimization of the surface area with the volume and the contact angle constraints. In order to simulate systems with different contact angles, we vary the parameters between the constitutive elements of the lattice gas. We numerically and analytically determine the phase diagram of the system as a function of the dimensionless parameters hΩ-1/3 and Θ . The regions of this phase diagram correspond to the mechanical stability and thermodynamical stability of the liquid bridge. We also determine the conditions for the symmetrical versus asymmetrical rupture of the bridge. We numerically and analytically compute the release of free energy during rupture. The simulation results are in agreement with the analytical solution. Furthermore, we discuss the results in connection

CHANGES IN PHYSIOLOGICAL TREMOR RESULTING FROM SLEEP DEPRIVATION UNDER CONDITIONS OF INCREASING FATIGUE DURING PROLONGED MILITARY TRAINING

OpenAIRE

A. Tomczak; J. Gajewski; J Mazur–Różycka

2015-01-01

The aim of the study was to define the changes of the characteristics of physiological postural tremor under conditions of increasing fatigue and lack of sleep during prolonged military training (survival).The subjects of the study were 15 students of the Polish Air Force Academy in Dęblin. The average age was 19.9±1.3 years. During the 36-hour-long continuous military training (survival) the subjects were deprived of sleep. Four tremor measurements were carried out for each of the subjects: ...

Physiological responses and physical performance during football in the heat

DEFF Research Database (Denmark)

Mohr, Magni; Nybo, Lars; Grantham, Justin

2012-01-01

To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play.......To examine the impact of hot ambient conditions on physical performance and physiological responses during football match-play....

Physiological constrains on Sverdrup's Critical-Depth-Hypothesis: the influences of dark respiration and sinking

DEFF Research Database (Denmark)

Lindemann, Christian; Backhaus, Jan O.; St. John, Michael

2015-01-01

of the spring bloom. However, they neglect the cells ability to modify vital rates in response to changes in the external environment. In this study, we use a non-hydrostatic convection model coupled to an Individual-Based-Model to simulate changes phytoplankton cells during the transition from winter...... conditions as driven by convective mixing, and the onset of thermal stratification resulting in the spring bloom. The comparison between a simulation using a standard fixed rate approach in line with the original Sverdrup hypothesis and a simulation parameterized to include variable respiration and sinking...... replicate field observations when employing unrealistic parameter values. These results highlight the necessity to consider not only the physical and biological external controls determining phytoplankton dynamics but also the cells ability to modify critical physiological rates in response to external...

Effect of Olive Pulpe Levels in The Diet of Buffalo Calves on Physiological Body Functions and Productive Traits Under Heat Stress Conditions

International Nuclear Information System (INIS)

Gad, A.E.

2013-01-01

The present study was planned to investigate the changes that occur in growth and some physiological traits in buffalo calves as a result of using olive pulp levels (20 or 40%) under different conditions in Egypt. The study was carried out on 30 male growing buffalo calves aged 14-16 months with average body weight 309 kg and including two experiments; the 1st was carried out under mild climate in winter season on 15 calves while the 2nd was conducted during heat stress conditions of summer season on another 15 calves. In each of the two periods, animals were divided into three equal groups (5 buffalo calves in each). The first group was considered as control to olive pulp levels of 0% . The second and third groups receive olive pulp with 20 and 40% of the ingredient ration, respectively. The results showed that heat stress conditions of hot period induced significant decreases in the levels of final live body weight (FLBW), daily body weight gain (DBWG), total body weight gain (TBWG), total protein, albumin, total lipids, total cholesterol, Ca, inorganic P and thyroid hormones level (T4 and T3). On the other hand, significant increase in urea-N, creatinine, GOT and GPT as compared with animals under mild conditions was recorded. Olive pulp levels in the diet affected significantly the total body gain, daily body weight gain, total cholesterol and thyroid hormones (T4 or T3). The values were lower in the group received 40% olive pulp than in the two groups received 0 and 20.0 % olive pulp. In addition, animals received 40% olive pulp showed significant increase in urea-N, creatinine, GPT, total lipids and Ca. It could be concluded that heat stress conditions of summer period induced significant depression in daily body weight gain and changed most blood components and thyroid hormones which related to physiological functions in buffalo calves. Concerning added olive pulp to the ration of buffalo calves, it could be concluded that daily body gain of buffalo calves

Simulation of gas turbines operating in off-design condition

Energy Technology Data Exchange (ETDEWEB)

Walter, Arnaldo [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: walter@fem.unicamp.br

2000-07-01

In many countries thermal power plants based on gas turbines have been the main option for new investment into the electric system due to their relatively high efficiency and low capital cost. Cogeneration systems based on gas turbines have also been an important option for the electric industry. Feasibility studies of power plants based on gas turbine should consider the effect of atmospheric conditions and part-load operation on the machine performance. Doing this, an off-design procedure is required. A G T off-design simulation procedure is described in this paper. Ruston R M was used to validate the simulation procedure that, general sense, presents deviations lower than 2.5% in comparison to manufacturer's data. (author)

Simulation-Based Planning of Optimal Conditions for Industrial Computed Tomography

DEFF Research Database (Denmark)

Reisinger, S.; Kasperl, S.; Franz, M.

2011-01-01

We present a method to optimise conditions for industrial computed tomography (CT). This optimisation is based on a deterministic simulation. Our algorithm finds task-specific CT equipment settings to achieve optimal exposure parameters by means of an STL-model of the specimen and a raytracing...

Simulated Fission Gas Behavior in Silicide Fuel at LWR Conditions

Energy Technology Data Exchange (ETDEWEB)

Miao, Yinbin [Argonne National Lab. (ANL), Argonne, IL (United States); Mo, Kun [Argonne National Lab. (ANL), Argonne, IL (United States); Yacout, Abdellatif [Argonne National Lab. (ANL), Argonne, IL (United States); Harp, Jason [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-15

As a promising candidate for the accident tolerant fuel (ATF) used in light water reactors (LWRs), the fuel performance of uranium silicide (U₃Si₂) at LWR conditions needs to be well-understood. However, existing experimental post-irradiation examination (PIE) data are limited to the research reactor conditions, which involve lower fuel temperature compared to LWR conditions. This lack of appropriate experimental data significantly affects the development of fuel performance codes that can precisely predict the microstructure evolution and property degradation at LWR conditions, and therefore evaluate the qualification of U₃Si₂ as an AFT for LWRs. Considering the high cost, long timescale, and restrictive access of the in-pile irradiation experiments, this study aims to utilize ion irradiation to simulate the inpile behavior of the U₃Si₂ fuel. Both in situ TEM ion irradiation and ex situ high-energy ATLAS ion irradiation experiments were employed to simulate different types of microstructure modifications in U₃Si₂. Multiple PIE techniques were used or will be used to quantitatively analyze the microstructure evolution induced by ion irradiation so as to provide valuable reference for the development of fuel performance code prior to the availability of the in-pile irradiation data.

Coupling of the Models of Human Physiology and Thermal Comfort

Science.gov (United States)

Pokorny, J.; Jicha, M.

2013-04-01

A coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. A coupling combines a modified Tanabe model of human physiology and thermal comfort model developed by Zhang. The Coupled model allows predicting the thermal sensation and comfort of both local and overall from local boundary conditions representing ambient and personal factors. The aim of this study was to compare prediction of the Coupled model with the Fiala model prediction and experimental data. Validation data were taken from the literature, mainly from the validation manual of software Theseus-FE [1]. In the paper validation of the model for very light physical activities (1 met) indoor environment with temperatures from 12 °C up to 48 °C is presented. The Coupled model predicts mean skin temperature for cold, neutral and warm environment well. However prediction of core temperature in cold environment is inaccurate and very affected by ambient temperature. Evaluation of thermal comfort in warm environment is supplemented by skin wettedness prediction. The Coupled model is designed for non-uniform and transient environmental conditions; it is also suitable simulation of thermal comfort in vehicles cabins. The usage of the model is limited for very light physical activities up to 1.2 met only.

Coupling of the Models of Human Physiology and Thermal Comfort

Directory of Open Access Journals (Sweden)

Jicha M.

2013-04-01

Full Text Available A coupled model of human physiology and thermal comfort was developed in Dymola/Modelica. A coupling combines a modified Tanabe model of human physiology and thermal comfort model developed by Zhang. The Coupled model allows predicting the thermal sensation and comfort of both local and overall from local boundary conditions representing ambient and personal factors. The aim of this study was to compare prediction of the Coupled model with the Fiala model prediction and experimental data. Validation data were taken from the literature, mainly from the validation manual of software Theseus–FE [1]. In the paper validation of the model for very light physical activities (1 met indoor environment with temperatures from 12 °C up to 48 °C is presented. The Coupled model predicts mean skin temperature for cold, neutral and warm environment well. However prediction of core temperature in cold environment is inaccurate and very affected by ambient temperature. Evaluation of thermal comfort in warm environment is supplemented by skin wettedness prediction. The Coupled model is designed for non-uniform and transient environmental conditions; it is also suitable simulation of thermal comfort in vehicles cabins. The usage of the model is limited for very light physical activities up to 1.2 met only.

Physicochemical characterization of engineered nanoparticles under physiological conditions: effect of culture media components and particle surface coating.

Science.gov (United States)

Fatisson, Julien; Quevedo, Ivan R; Wilkinson, Kevin J; Tufenkji, Nathalie

2012-03-01

The use of engineered nanoparticles (ENPs) in commercial products has increased substantially over the last few years. Some research has been conducted in order to determine whether or not such materials are cytotoxic, but questions remain regarding the role that physiological media and sera constituents play in ENP aggregation or stabilization. In this study, several characterization methods were used to evaluate the particle size and surface potential of 6 ENPs suspended in a number of culture media and in the presence of different culture media constituents. Dynamic light scattering (DLS) and fluorescence correlation spectroscopy (FCS) were employed for size determinations. Results were interpreted on the basis of ENP surface potentials evaluated from particle electrophoretic mobilities (EPM). Measurements made after 24h of incubation at 37°C showed that the cell culture medium constituents had only moderate impact on the physicochemical properties of the ENP, although incubation in bovine serum albumin destabilized the colloidal system. In contrast, most of the serum proteins increased colloidal stabilization. Moreover, the type of ENP surface modification played a significant role in ENP behavior whereby the complexity of interactions between the ENPs and the medium components generally decreased with increasing complexity of the particle surface. This investigation emphasizes the importance of ENP characterization under conditions that are representative of cell culture media or physiological conditions for improved assessments of nanoparticle cytotoxicity. Copyright © 2011 Elsevier B.V. All rights reserved.

A counterpoint between computer simulations and biological experiments to train new members of a laboratory of physiological sciences.

Science.gov (United States)

Ozu, Marcelo; Dorr, Ricardo A; Gutiérrez, Facundo; Politi, M Teresa; Toriano, Roxana

2012-12-01

When new members join a working group dedicated to scientific research, several changes occur in the group's dynamics. From a teaching point of view, a subsequent challenge is to develop innovative strategies to train new staff members in creative thinking, which is the most complex and abstract skill in the cognitive domain according to Bloom's revised taxonomy. In this sense, current technological and digital advances offer new possibilities in the field of education. Computer simulation and biological experiments can be used together as a combined tool for teaching and learning sometimes complex physiological and biophysical concepts. Moreover, creativity can be thought of as a social process that relies on interactions among staff members. In this regard, the acquisition of cognitive abilities coexists with the attainment of other skills from psychomotor and affective domains. Such dynamism in teaching and learning stimulates teamwork and encourages the integration of members of the working group. A practical example, based on the teaching of biophysical subjects such as osmosis, solute transport, and membrane permeability, which are crucial in understanding the physiological concept of homeostasis, is presented.

Anatomic and physiological modifications in seedlings of Coffea arabica cultivar Siriema under drought conditions

Directory of Open Access Journals (Sweden)

Emanuelle Ferreira Melo

2014-02-01

Full Text Available Due to the weather changes prognostic for the coming years, the understanding of water deficit and physiological responses of plants to drought becomes an important requirement in order to develop technologies such as mechanisms to assist plants to cope with longer drought periods, which will be essential to maintenance of Brazilian and worldwide production. This study aimed to evaluate ecophysiological and anatomical aspects as well as the nitrate reductase activity in Siriema coffee seedlings subjected to four treatments: Daily irrigated, non-irrigated, re-irrigated 24 hours and re-irrigated 48 hours after different stress periods. Non-irrigation promoted a reduction in leaf water potential being accented from the ninth day of evaluation onwards. Re-irrigation promoted a partial recovery of the plant water potential. Non-irrigated plants showed an increase in stomatal resistance and reduction of transpiration and nitrate reductase activity. In the roots, there was a decrease in nitrate reductase activity under water stress. Leaf anatomical modifications were significant only for the adaxial surface epidermis and palisade parenchyma thickness, this latter characteristic being higher in control plants. Stomatal density and polar and equatorial diameter ratios showed the highest values in plants under water stress. In the roots, differences only in the cortex thickness being bigger in the non-irrigated treatment could be observed. Therefore, Siriema coffee plants under water stress show physiological, biochemical and anatomical modifications that contribute to the tolerance of this genotype to these conditions.

A Simulation of Strategic Decision Making in Situational Stereotype Conditions for Entrepreneurial Companies.

Science.gov (United States)

West, G. Page, III; Wilson, E. Vance

1995-01-01

Examines simulation in entrepreneurial research, reviews cognitive structures and theories, and presents a computerized simulation of strategic decision-making in situational stereotype conditions for entrepreneurial companies. The study suggests repeated exposure to a pattern recognition issue in entrepreneurship may lead to a broader…

21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological signal...

Physiological and behavioral responses to the social environment

International Nuclear Information System (INIS)

Davis, D.E.

1978-01-01

Physiological and behavioral reactions to the social environment are mediated in nature principally through aggressive interactions, although in some cases other aspects of the environment such as temperature or predators are important. Observations from 1946-50 of changes in populations of rats after alteration of social conditions suggested the hypothesis that changes in birth and mortality rates followed aggressive interactions. The pituitary-adrenal-gonadal mechanism provided a process that could be tested in three types of conditions: laboratory, simulated field, and field. Changes in social environment can result from: seasonal changes in conditions; appearance of transients; habitat changes due to succession; and increase of population. It became apparent from laboratory research that a physiological feedback from aggressive behavior could reduce birth rates and increase mortality rates. Studies in nature showed that a reduction of Norway rat population by 38 percent was followed by a reduction of adrenal weight by 32 percent. Also as the population of rats increased the weight of the adrenals increased. A comprehensive study of woodchucks, started in 1957, showed that the alteration of age composition and the increase in immigration was associated with increased adrenal function. Research by others on lemmings shows that the adrenals at the peak of a population fluctuation are larger and produce more hormones than at the low point. No evidence was obtained to support the hypothesis that genetic selection for aggressive behavior within the population occurs during the increase or decline of a population. The changes occur within an individual. The future of studies of responses to the social environment will require experimental programs in nature that last for a decade or more, long enough to monitor changes in numbers under a variety of conditions

Surface analysis and electrochemical behavior of Ti–20Zr alloy in simulated physiological fluids

Energy Technology Data Exchange (ETDEWEB)

Calderon Moreno, Jose Maria; Vasilescu, Ecaterina; Drob, Paula; Osiceanu, Petre; Vasilescu, Cora; Drob, Silviu Iulian, E-mail: sidrob@chimfiz.icf.ro; Popa, Monica

2013-11-01

Highlights: • The advanced Ti–20Zr alloy shows fully lamellar α + β microstructure. • The alloy passive film improves its properties by deposition of HA (XPS, SEM, EDX, Raman, FT-IR). • Alloy revealed lower corrosion rates and higher polarization resistances than Ti. • EIS spectra depicted a more protective passive film on the alloy surface than on Ti. • The passive film is formed by two layers: an inner barrier and an outer porous layer. -- Abstract: An advanced Ti–20Zr alloy was obtained by double vacuum melting in a semi-levitation furnace with cold crucible. The alloy shows fully lamellar α + β microstructure. Cyclic potentiodynamic polarization curves revealed that the alloy passivated easier, more rapid than Ti, having a more stable passive film in Ringer solutions of different pH values, simulating severe functional conditions of an implant. In neutral and alkaline Ringer solutions, the alloy passive film improved its properties in time (1500 h) by the deposition of protective hydroxyapatite, as was demonstrated by XPS, SEM, EDX, Raman and FT-IR measurements. Alloy presented lower corrosion rates and higher polarization resistances (from linear polarization measurements) than those of Ti (tens of times) proving a more resistant passive film. Alloy open circuit potentials had more electropositive values in comparison with Ti and tended to nobler values in time, which denote better passive state and its enhancement in time, due to the new depositions from the physiological solutions. Nyquist and Bode spectra depicted a more protective passive film on the alloy surface than on Ti surface. The passive film is formed by two layers: an inner barrier layer and an outer porous layer. An electric equivalent circuit with two time constants was modeled.

Surface analysis and electrochemical behavior of Ti–20Zr alloy in simulated physiological fluids

International Nuclear Information System (INIS)

Calderon Moreno, Jose Maria; Vasilescu, Ecaterina; Drob, Paula; Osiceanu, Petre; Vasilescu, Cora; Drob, Silviu Iulian; Popa, Monica

2013-01-01

Highlights: • The advanced Ti–20Zr alloy shows fully lamellar α + β microstructure. • The alloy passive film improves its properties by deposition of HA (XPS, SEM, EDX, Raman, FT-IR). • Alloy revealed lower corrosion rates and higher polarization resistances than Ti. • EIS spectra depicted a more protective passive film on the alloy surface than on Ti. • The passive film is formed by two layers: an inner barrier and an outer porous layer. -- Abstract: An advanced Ti–20Zr alloy was obtained by double vacuum melting in a semi-levitation furnace with cold crucible. The alloy shows fully lamellar α + β microstructure. Cyclic potentiodynamic polarization curves revealed that the alloy passivated easier, more rapid than Ti, having a more stable passive film in Ringer solutions of different pH values, simulating severe functional conditions of an implant. In neutral and alkaline Ringer solutions, the alloy passive film improved its properties in time (1500 h) by the deposition of protective hydroxyapatite, as was demonstrated by XPS, SEM, EDX, Raman and FT-IR measurements. Alloy presented lower corrosion rates and higher polarization resistances (from linear polarization measurements) than those of Ti (tens of times) proving a more resistant passive film. Alloy open circuit potentials had more electropositive values in comparison with Ti and tended to nobler values in time, which denote better passive state and its enhancement in time, due to the new depositions from the physiological solutions. Nyquist and Bode spectra depicted a more protective passive film on the alloy surface than on Ti surface. The passive film is formed by two layers: an inner barrier layer and an outer porous layer. An electric equivalent circuit with two time constants was modeled

Properties of Lactobacillus reuteri chitosan-calcium-alginate encapsulation under simulated gastrointestinal conditions.

Science.gov (United States)

Huang, Hui-Ying; Tang, Yi-Ju; King, V An-Erl; Chou, Jen-Wei; Tsen, Jen-Horng

2015-03-01

The protective effects of encapsulation on the survival of Lactobacillus reuteri and the retention of the bacterium's probiotic properties under simulated gastrointestinal conditions were investigated. Viable counts and the remaining probiotic properties of calcium (Ca)-alginate encapsulated (A group), chitosan-Ca-alginate encapsulated (CA group), and unencapsulated, free L. reuteri (F group) were determined. Encapsulation improved the survival of L. reuteri subjected to simulated gastrointestinal conditions, with the greatest protective effect achieved in the CA group. The degree of cell membrane injury increased with increasing bile salt concentrations at constant pH, but the extent of injury was less in the encapsulated than in the free cells. Adherence rates were, in descending order: CA (0.524%)>A (0.360%)>F (0.275%). Lactobacillus reuteri cells retained their antagonistic activity toward Listeria monocytogenes even after incubation of the lactobacilli under simulated gastrointestinal conditions. Displacement of the pathogen by cells released from either of the encapsulation matrices was higher than that by free cells. The safety of L. reuteri was demonstrated in an in vitro invasion assay. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

Physiological Responses to Two Hypoxic Conditioning Strategies in Healthy Subjects.

Science.gov (United States)

Chacaroun, Samarmar; Borowik, Anna; Morrison, Shawnda A; Baillieul, Sébastien; Flore, Patrice; Doutreleau, Stéphane; Verges, Samuel

2016-01-01

Objective: Hypoxic exposure can be used as a therapeutic tool by inducing various cardiovascular, neuromuscular, and metabolic adaptations. Hypoxic conditioning strategies have been evaluated in patients with chronic diseases using either sustained (SH) or intermittent (IH) hypoxic sessions. Whether hypoxic conditioning via SH or IH may induce different physiological responses remains to be elucidated. Methods: Fourteen healthy active subjects (7 females, age 25 ± 8 years, body mass index 21.5 ± 2.5 kg·m -2 ) performed two interventions in a single blind, randomized cross-over design, starting with either 3 x SH (48 h apart), or 3 x IH (48 h apart), separated by a 2 week washout period. SH sessions consisted of breathing a gas mixture with reduced inspiratory oxygen fraction (FiO 2 ), continuously adjusted to reach arterial oxygen saturations (SpO 2 ) of 70-80% for 1 h. IH sessions consisted of 5 min with reduced FiO 2 (SpO 2 = 70-80%), followed by 3-min normoxia, repeated seven times. During the first (S1) and third (S3) sessions of each hypoxic intervention, cardiorespiratory parameters, and muscle and pre-frontal cortex oxygenation (near infrared spectroscopy) were assessed continuously. Results : Minute ventilation increased significantly during IH sessions (+2 ± 2 L·min -1 ) while heart rate increased during both SH (+11 ± 4 bpm) and IH (+13 ± 5 bpm) sessions. Arterial blood pressure increased during all hypoxic sessions, although baseline normoxic systolic blood pressure was reduced from S1 to S3 in IH only (-8 ± 11 mmHg). Muscle oxygenation decreased significantly during S3 but not S1, for both hypoxic interventions (S3: SH -6 ± 5%, IH -3 ± 4%); pre-frontal oxygenation decreased in S1 and S3, and to a greater extent in SH vs. IH (-13 ± 3% vs. -6 ± 6%). Heart rate variability indices indicated a significantly larger increase in sympathetic activity in SH vs. IH (lower SDNN, PNN50, and RMSSD values in SH). From S1 to S3, further reduction in heart

Interaction of oxides of nitrogen and aromatic hydrocarbons under simulated atmospheric conditions

International Nuclear Information System (INIS)

Obrien, R.J.; Green, P.J.; Doty, R.A.; Vanderzanden, J.W.; Easton, R.R.; Irwin, R.P.

1979-01-01

The reactions of nitrogen oxides with aromatic hydrocarbons under simulated atmospheric conditions are investigated. Gaseous reaction products formed when toluene is irradiated under simulated atmospheric conditions in the presence of nitrogen oxides were analyzed by gas chromatography. Reaction products detected include acetylene, water, acetaldehyde, acetone, toluene, benzaldehyde, ortho-, meta- and para-cresol, benzyl nitrate and meta- and para-nitrotoluene. Reaction mechanisms yielding the various products are illustrated. The assumption that all the nitrogen oxides observed to be lost from the reaction products can be accounted for by nitric acid formation in the absence of ozone formation is verified by a model in which the hydroxyl radical is assumed to be the only means of removing toluene. Under conditions in which ozone is formed, nitrogen oxide loss is accounted for by ozone formation in addition to nitric acid formation

Emotion of Physiological Signals Classification Based on TS Feature Selection

Institute of Scientific and Technical Information of China (English)

Wang Yujing; Mo Jianlin

2015-01-01

This paper propose a method of TS-MLP about emotion recognition of physiological signal.It can recognize emotion successfully by Tabu search which selects features of emotion’s physiological signals and multilayer perceptron that is used to classify emotion.Simulation shows that it has achieved good emotion classification performance.

Physiological and subjective responses in the elderly when using floor heating and air conditioning systems.

Science.gov (United States)

Hashiguchi, Nobuko; Tochihara, Yutaka; Ohnaka, Tadakatsu; Tsuchida, Chiaki; Otsuki, Tamio

2004-11-01

The purpose of this study was to investigate the effects of a floor heating and air conditioning system on thermal responses of the elderly. Eight elderly men and eight university students sat for 90 minutes in a chair under the following 3 conditions: air conditioning system (A), floor heating system (F) and no heating system (C). The air temperature of sitting head height for condition A was 25 degrees C, and the maximum difference in vertical air temperature was 4 degrees C. The air and floor temperature for condition F were 21 and 29 degrees C, respectively. The air temperature for condition C was 15 degrees C. There were no significant differences in rectal temperature and mean skin temperature between condition A and F. Systolic blood pressure of the elderly men in condition C significantly increased compared to those in condition A and F. No significant differences in systolic blood pressure between condition A and F were found. The percentage of subjects who felt comfortable under condition F was higher than that of those under condition A in both age groups, though the differences between condition F and A was not significant. Relationships between thermal comfort and peripheral (e.g., instep, calf, hand) skin temperature, and the relationship between thermal comfort and leg thermal sensation were significant for both age groups. However, the back and chest skin temperature and back thermal sensation for the elderly, in contrast to that for the young, was not significantly related to thermal comfort. These findings suggested that thermal responses and physiological strain using the floor heating system did not significantly differ from that using the air conditioning system, regardless of the subject age and despite the fact that the air temperature with the floor heating system was lower. An increase in BP for elderly was observed under the condition in which the air temperature was 15 degrees C, and it was suggested that it was necessary for the elderly

Effects of hydroxocobalamin on carboxyhemoglobin measured under physiologic and pathologic conditions.

Science.gov (United States)

Pace, R; Bon Homme, M; Hoffman, R S; Lugassy, D

2014-08-01

Pre-hospital administration of hydroxocobalamin (B12a) is used for empiric treatment of cyanide poisoning because cyanide poisoning is difficult to identify and requires immediate treatment. B12a interferes with the accuracy of several blood laboratory tests. This study aimed to explore how B12a affects carboxyhemoglobin (COHb) measurements in human blood at both physiologic and pathologic COHb levels. Several clinically relevant concentrations of B12a were added to human blood samples containing physiologic (∼ 3%) and pathologic (30% and 50%) COHb levels. We then measured the COHb levels of the samples using two different co-oximeters, the Radiometer ABL 700 and the Rapidpoint 500, and compared to their actual baseline COHb levels. B12a had minimal effects on the COHb measured at both physiologic and pathologic levels when measured on the Radiometer. In contrast, the Rapidpoint B12a caused a dose-dependent decrease in the COHb measured, especially of pathologic COHb levels (∼ 30 and 50%). The magnitude of B12a interference on measured COHb is dependent upon the specific co-oximeter used, the actual COHb level and the serum B12a concentration. These errors may potentially influence clinical decision making and thus affect patient outcomes. Our findings emphasize the importance of measuring COHb levels on blood samples collected prior to B12a administration.

Physiological age at harvest regulates the variability in postharvest ripening, sensory and nutritional characteristics of mango (Mangifera indica L.) cv. Coghshall due to growing conditions.

Science.gov (United States)

Joas, Jacques; Vulcain, Emmanuelle; Desvignes, Claire; Morales, Emeline; Léchaudel, Mathieu

2012-04-01

Climacteric fruits are harvested at the green-mature stage and ripen during their marketing cycle. However, growing conditions induce variability into the maturity stage of mangoes at harvest, with an impact on their final quality. Assuming that the physiological age can be correctly evaluated by a criterion based on the variable chlorophyll fluorescence of the skin (F(v)) and that differences in physiological age depend on growing conditions, controlled stress experiments were carried out on mango fruit by manipulating either the leaf/fruit ratio or the light environment. Delays from 9 to 30 days were observed, depending on stress level and harvest stage, to obtain the same F(v) value. For moderate stress, fruit composition after ripening was partially compensated for, with little or no difference in sugar, dry matter, carotenoid and aroma contents. For more pronounced stress, the major metabolites were not particularly affected, but the synthesis capacity of carotenoids and aromas was lower after maturity. The ripening ability of a fruit is acquired on the tree and defines its postharvest changes. Control of the physiological age at harvest can minimise the variability observed under natural conditions and guarantee fruit batches whose postharvest changes will be relatively homogeneous. Copyright © 2011 Society of Chemical Industry.

The influence of antioxidants 'TIOFAN' and 'FANTOX 11-1' on physiological growth of broilers in conditions of intoxication with lead and cadmium salts

International Nuclear Information System (INIS)

Koval, Yu.I.; Bokova, T.I.; Kandalintseva, N.V.

2008-01-01

The purpose of research is to study the influence of antioxidants 'TIOFAN' and 'FANTOX 11-1' on physiological growth of broilers in conditions of intoxication with lead and cadmium salts. The growth and development of bird in conditions of intoxication with heavy metals and by using of antioxidants as detoxicant is studied. The biochemical blood values on application of antioxidants and without them in conditions of intoxication are determined. The most effective preparation raising of birds productivity and it's optimal concentration is established.

Physiological responses of batsmen during a simulated One Day ...

African Journals Online (AJOL)

Background: There is a limited amount of literature on the physiological cost of batting. Of the studies that have been completed, most have used protocols that are of short duration and high intensity, and it has been questioned whether this represents actual game play. Furthermore, it is difficult to study sports such as cricket ...

Simulators IV

International Nuclear Information System (INIS)

Fairchild, B.T.

1987-01-01

These proceedings contain papers on simulators with artificial intelligence, and the human decision making process; visuals for simulators: human factors, training, and psycho-physical impacts; the role of institutional structure on simulation projects; maintenance trainers for economic value and safety; biomedical simulators for understanding nature, for medical benefits, and the physiological effects of simulators; the mathematical models and numerical techniques that drive today's simulators; and the demography of simulators, with census papers identifying the population of real-time simulator training devices; nuclear reactors

Simulation based planning of surgical interventions in pediatric cardiology

Science.gov (United States)

Marsden, Alison L.

2013-10-01

Hemodynamics plays an essential role in the progression and treatment of cardiovascular disease. However, while medical imaging provides increasingly detailed anatomical information, clinicians often have limited access to hemodynamic data that may be crucial to patient risk assessment and treatment planning. Computational simulations can now provide detailed hemodynamic data to augment clinical knowledge in both adult and pediatric applications. There is a particular need for simulation tools in pediatric cardiology, due to the wide variation in anatomy and physiology in congenital heart disease patients, necessitating individualized treatment plans. Despite great strides in medical imaging, enabling extraction of flow information from magnetic resonance and ultrasound imaging, simulations offer predictive capabilities that imaging alone cannot provide. Patient specific simulations can be used for in silico testing of new surgical designs, treatment planning, device testing, and patient risk stratification. Furthermore, simulations can be performed at no direct risk to the patient. In this paper, we outline the current state of the art in methods for cardiovascular blood flow simulation and virtual surgery. We then step through pressing challenges in the field, including multiscale modeling, boundary condition selection, optimization, and uncertainty quantification. Finally, we summarize simulation results of two representative examples from pediatric cardiology: single ventricle physiology, and coronary aneurysms caused by Kawasaki disease. These examples illustrate the potential impact of computational modeling tools in the clinical setting.

Automatic duress alarms through physiological response monitoring

International Nuclear Information System (INIS)

Roehrig, S.C.

1977-07-01

Physiological response monitoring under controlled conditions can provide an effective means for passively determining if the wearer is under moderate to severe stresses. By monitoring the heart rate (HR) and galvanic skin response (GSR) of an individual, it is possible to detect in real time the increase in heart rate and GSR levels due to physiological reactions to mental duress. With existing physiological monitoring equipment, however, the work load of the wearer must be well defined since it is impossible, without additional data, to distinguish mental duress responses from those resulting from moderate physical exertion. Similarly, environmental conditions should be constrained within set limits to avoid masking increases in GSR levels due to metntal stress from those associated with increased perspiration. These constraints should not prove overly restrictive and would allow an integrated security system utilizing physiological monitoring equipment to provide an effective real time, automated early warning system for detection of mental duress or death of the wearer

Simulation of worst-case operating conditions for integrated circuits operating in a total dose environment

International Nuclear Information System (INIS)

Bhuva, B.L.

1987-01-01

Degradations in the circuit performance created by the radiation exposure of integrated circuits are so unique and abnormal that thorough simulation and testing of VLSI circuits is almost impossible, and new ways to estimate the operating performance in a radiation environment must be developed. The principal goal of this work was the development of simulation techniques for radiation effects on semiconductor devices. The mixed-mode simulation approach proved to be the most promising. The switch-level approach is used to identify the failure mechanisms and critical subcircuits responsible for operational failure along with worst-case operating conditions during and after irradiation. For precise simulations of critical subcircuits, SPICE is used. The identification of failure mechanisms enables the circuit designer to improve the circuit's performance and failure-exposure level. Identification of worst-case operating conditions during and after irradiation reduces the complexity of testing VLSI circuits for radiation environments. The results of test circuits for failure simulations using a conventional simulator and the new simulator showed significant time savings using the new simulator. The savings in simulation time proved to be circuit topology-dependent. However, for large circuits, the simulation time proved to be orders of magnitude smaller than simulation time for conventional simulators

Interactions between vegetation, atmospheric turbulence and clouds under a wide range of background wind conditions

NARCIS (Netherlands)

Sikma, M.; Ouwersloot, H.G.; Pedruzo-Bagazgoitia, X.; Heerwaarden, van C.C.; Vilà-Guerau de Arellano, J.

2018-01-01

The effects of plant responses to cumulus (Cu) cloud shading are studied from free convective to shear-driven boundary-layer conditions. By using a large-eddy simulation (LES) coupled to a plant physiology embedded land-surface submodel, we study the vegetation-cloud feedbacks for a wide range (44)

Second order bounce back boundary condition for the lattice Boltzmann fluid simulation

International Nuclear Information System (INIS)

Kim, In Chan

2000-01-01

A new bounce back boundary method of the second order in error is proposed for the lattice Boltzmann fluid simulation. This new method can be used for the arbitrarily irregular lattice geometry of a non-slip boundary. The traditional bounce back boundary condition for the lattice Boltzmann simulation is of the first order in error. Since the lattice Boltzmann method is the second order scheme by itself, a boundary technique of the second order has been desired to replace the first order bounce back method. This study shows that, contrary to the common belief that the bounce back boundary condition is unilaterally of the first order, the second order bounce back boundary condition can be realized. This study also shows that there exists a generalized bounce back technique that can be characterized by a single interpolation parameter. The second order bounce back method can be obtained by proper selection of this parameter in accordance with the detailed lattice geometry of the boundary. For an illustrative purpose, the transient Couette and the plane Poiseuille flows are solved by the lattice Boltzmann simulation with various boundary conditions. The results show that the generalized bounce back method yields the second order behavior in the error of the solution, provided that the interpolation parameter is properly selected. Coupled with its intuitive nature and the ease of implementation, the bounce back method can be as good as any second order boundary method

Mycorrhizal association between the desert truffle Terfezia boudieri and Helianthemum sessiliflorum alters plant physiology and fitness to arid conditions.

Science.gov (United States)

Turgeman, Tidhar; Ben Asher, Jiftach; Roth-Bejerano, Nurit; Kagan-Zur, Varda; Kapulnik, Yoram; Sitrit, Yaron

2011-10-01

The host plant Helianthemum sessiliflorum was inoculated with the mycorrhizal desert truffle Terfezia boudieri Chatin, and the subsequent effects of the ectomycorrhizal relationship on host physiology were determined. Diurnal measurements revealed that mycorrhizal (M) plants had higher rates of photosynthesis (35%), transpiration (18%), and night respiration (49%) than non-mycorrhizal (NM) plants. Consequently, M plants exhibited higher biomass accumulation, higher shoot-to-root ratios, and improved water use efficiency compared to NM plants. Total chlorophyll content was higher in M plants, and the ratio between chlorophyll a to chlorophyll b was altered in M plants. The increase in chlorophyll b content was significantly higher than the increase in chlorophyll a content (2.58- and 1.52-fold, respectively) compared to control. Calculation of the photosynthetic activation energy indicated lower energy requirements for CO(2) assimilation in M plants than in NM plants (48.62 and 61.56 kJ mol(-1), respectively). Continuous measurements of CO(2) exchange and transpiration in M plants versus NM plants provided a complete picture of the daily physiological differences brought on by the ectomycorrhizal relationships. The enhanced competence of M plants to withstand the harsh environmental conditions of the desert is discussed in view of the mycorrhizal-derived alterations in host physiology. © Springer-Verlag 2011

Multi-Scale Initial Conditions For Cosmological Simulations

Energy Technology Data Exchange (ETDEWEB)

Hahn, Oliver; /KIPAC, Menlo Park; Abel, Tom; /KIPAC, Menlo Park /ZAH, Heidelberg /HITS, Heidelberg

2011-11-04

We discuss a new algorithm to generate multi-scale initial conditions with multiple levels of refinements for cosmological 'zoom-in' simulations. The method uses an adaptive convolution of Gaussian white noise with a real-space transfer function kernel together with an adaptive multi-grid Poisson solver to generate displacements and velocities following first- (1LPT) or second-order Lagrangian perturbation theory (2LPT). The new algorithm achieves rms relative errors of the order of 10{sup -4} for displacements and velocities in the refinement region and thus improves in terms of errors by about two orders of magnitude over previous approaches. In addition, errors are localized at coarse-fine boundaries and do not suffer from Fourier-space-induced interference ringing. An optional hybrid multi-grid and Fast Fourier Transform (FFT) based scheme is introduced which has identical Fourier-space behaviour as traditional approaches. Using a suite of re-simulations of a galaxy cluster halo our real-space-based approach is found to reproduce correlation functions, density profiles, key halo properties and subhalo abundances with per cent level accuracy. Finally, we generalize our approach for two-component baryon and dark-matter simulations and demonstrate that the power spectrum evolution is in excellent agreement with linear perturbation theory. For initial baryon density fields, it is suggested to use the local Lagrangian approximation in order to generate a density field for mesh-based codes that is consistent with the Lagrangian perturbation theory instead of the current practice of using the Eulerian linearly scaled densities.

Use of animal models for space flight physiology studies, with special focus on the immune system

Science.gov (United States)

Sonnenfeld, Gerald

2005-01-01

Animal models have been used to study the effects of space flight on physiological systems. The animal models have been used because of the limited availability of human subjects for studies to be carried out in space as well as because of the need to carry out experiments requiring samples and experimental conditions that cannot be performed using humans. Experiments have been carried out in space using a variety of species, and included developmental biology studies. These species included rats, mice, non-human primates, fish, invertebrates, amphibians and insects. The species were chosen because they best fit the experimental conditions required for the experiments. Experiments with animals have also been carried out utilizing ground-based models that simulate some of the effects of exposure to space flight conditions. Most of the animal studies have generated results that parallel the effects of space flight on human physiological systems. Systems studied have included the neurovestibular system, the musculoskeletal system, the immune system, the neurological system, the hematological system, and the cardiovascular system. Hindlimb unloading, a ground-based model of some of the effects of space flight on the immune system, has been used to study the effects of space flight conditions on physiological parameters. For the immune system, exposure to hindlimb unloading has been shown to results in alterations of the immune system similar to those observed after space flight. This has permitted the development of experiments that demonstrated compromised resistance to infection in rodents maintained in the hindlimb unloading model as well as the beginning of studies to develop countermeasures to ameliorate or prevent such occurrences. Although there are limitations to the use of animal models for the effects of space flight on physiological systems, the animal models should prove very valuable in designing countermeasures for exploration class missions of the future.

[Nursing students assessment in simulated conditions : in search of meaning and ethics].

Science.gov (United States)

Homerin, Marie-Pierre; Roumanet, Marie-Cécile

2014-10-01

A thought about the assessment in simulated conditions is at the origin of this research-action conducted at the Institute of Nursing Education of Chambery, France. Indeed, the differences in the assessment procedures between units that require this kind of validation and the disappointing rate of success at the examinations in simulated situations have led the trainers to raise the following question : « How can these assessments be meaningful and consistent with the goal of training (help to become autonomous and reflexive practitioners) » ?This issue was addressed with concepts such as socioconstructivism, simulation in health, assessment and ethical principles. The change of practices has been the application of the principles of ?educative? assessment according to G. Nunziatti which strongly involves the students in the assessment?s process.In order to estimate the impact of these changes of practices, an unidentified online survey was offered to all students who benefited from this kind of assessment. The results between two classes of students having had different evaluation procedures have also been compared.The objectives were, after the implementation of this new kind of evaluation, to assess the students? satisfaction, to compare the failure rate at the tests in simulated conditions and to verify the compliance with the ethical principles.This study has shown the students? satisfaction about these new forms of assessment in simulated conditions, an increased success rate in the tests and the applicability of the ethical principles with this way of proceeding. However, the principles of justice and non-maleficence are difficult to implement. Nevertheless, this critical thinking on the procedures of assessment in simulated conditions has helped to change the practices and the assessment design by the teachers.

Study on operational condition of electro-decontamination by computer simulation

International Nuclear Information System (INIS)

Amamoto, Ippei; Sato, Koji; Kawabe, Akihiro; Fujita, Reiko; Terai, Takayuki

2005-01-01

The molten-salt electro-decontamination method can be taken up as adecontamination method for contaminated metal systems generated in the reprocessing using the fluoride volatility method, etc. This method makes a small amount of secondary waste and is able to construct a small-size process in which a critical state is easily controlled. It can be further expected that an electrolytic current penetrates inside contaminated substances of complex shape. In this report, an appropriate operational condition was theoretically obtained by the simulation on the applicability of this method to decontamination of metal materials, and it was confirmed by a fundamental testing that the simulation result is reasonable. (M.H.)

Stochastic simulation of PWR vessel integrity for pressurized thermal shock conditions

International Nuclear Information System (INIS)

Jackson, P.S.; Moelling, D.S.

1984-01-01

A stochastic simulation methodology is presented for performing probabilistic analyses of Pressurized Water Reactor vessel integrity. Application of the methodology to vessel-specific integrity analyses is described in the context of Pressurized Thermal Shock (PTS) conditions. A Bayesian method is described for developing vessel-specific models of the density of undetected volumetric flaws from ultrasonic inservice inspection results. Uncertainty limits on the probabilistic results due to sampling errors are determined from the results of the stochastic simulation. An example is provided to illustrate the methodology

Influence of Spanwise Boundary Conditions on Slat Noise Simulations

Science.gov (United States)

Lockard, David P.; Choudhari, Meelan M.; Buning, Pieter G.

2015-01-01

The slat noise from the 30P/30N high-lift system is being investigated through computational fluid dynamics simulations with the OVERFLOW code in conjunction with a Ffowcs Williams-Hawkings acoustics solver. In the present study, two different spanwise grids are being used to investigate the effect of the spanwise extent and periodicity on the near-field unsteady structures and radiated noise. The baseline grid with periodic boundary conditions has a short span equal to 1/9th of the stowed chord, whereas the other, longer span grid adds stretched grids on both sides of the core, baseline grid to allow inviscid surface boundary conditions at both ends. The results indicate that the near-field mean statistics obtained using the two grids are similar to each other, as are the directivity and spectral shapes of the radiated noise. However, periodicity forces all acoustic waves with less than one wavelength across the span to be two-dimensional, without any variation in the span. The spanwise coherence of the acoustic waves is what is needed to make estimates of the noise that would be radiated from realistic span lengths. Simulations with periodic conditions need spans of at least six slat chords to allow spanwise variation in the low-frequencies associated with the peak of broadband slat noise. Even then, the full influence of the periodicity is unclear, so employing grids with a fine, central region and highly stretched meshes that go to slip walls may be a more efficient means of capturing the spanwise decorrelation of low-frequency acoustic phenomena.

From inverse problems in mathematical physiology to quantitative differential diagnoses.

Directory of Open Access Journals (Sweden)

Sven Zenker

2007-11-01

Full Text Available The improved capacity to acquire quantitative data in a clinical setting has generally failed to improve outcomes in acutely ill patients, suggesting a need for advances in computer-supported data interpretation and decision making. In particular, the application of mathematical models of experimentally elucidated physiological mechanisms could augment the interpretation of quantitative, patient-specific information and help to better target therapy. Yet, such models are typically complex and nonlinear, a reality that often precludes the identification of unique parameters and states of the model that best represent available data. Hypothesizing that this non-uniqueness can convey useful information, we implemented a simplified simulation of a common differential diagnostic process (hypotension in an acute care setting, using a combination of a mathematical model of the cardiovascular system, a stochastic measurement model, and Bayesian inference techniques to quantify parameter and state uncertainty. The output of this procedure is a probability density function on the space of model parameters and initial conditions for a particular patient, based on prior population information together with patient-specific clinical observations. We show that multimodal posterior probability density functions arise naturally, even when unimodal and uninformative priors are used. The peaks of these densities correspond to clinically relevant differential diagnoses and can, in the simplified simulation setting, be constrained to a single diagnosis by assimilating additional observations from dynamical interventions (e.g., fluid challenge. We conclude that the ill-posedness of the inverse problem in quantitative physiology is not merely a technical obstacle, but rather reflects clinical reality and, when addressed adequately in the solution process, provides a novel link between mathematically described physiological knowledge and the clinical concept of

From Inverse Problems in Mathematical Physiology to Quantitative Differential Diagnoses

Science.gov (United States)

Zenker, Sven; Rubin, Jonathan; Clermont, Gilles

2007-01-01

The improved capacity to acquire quantitative data in a clinical setting has generally failed to improve outcomes in acutely ill patients, suggesting a need for advances in computer-supported data interpretation and decision making. In particular, the application of mathematical models of experimentally elucidated physiological mechanisms could augment the interpretation of quantitative, patient-specific information and help to better target therapy. Yet, such models are typically complex and nonlinear, a reality that often precludes the identification of unique parameters and states of the model that best represent available data. Hypothesizing that this non-uniqueness can convey useful information, we implemented a simplified simulation of a common differential diagnostic process (hypotension in an acute care setting), using a combination of a mathematical model of the cardiovascular system, a stochastic measurement model, and Bayesian inference techniques to quantify parameter and state uncertainty. The output of this procedure is a probability density function on the space of model parameters and initial conditions for a particular patient, based on prior population information together with patient-specific clinical observations. We show that multimodal posterior probability density functions arise naturally, even when unimodal and uninformative priors are used. The peaks of these densities correspond to clinically relevant differential diagnoses and can, in the simplified simulation setting, be constrained to a single diagnosis by assimilating additional observations from dynamical interventions (e.g., fluid challenge). We conclude that the ill-posedness of the inverse problem in quantitative physiology is not merely a technical obstacle, but rather reflects clinical reality and, when addressed adequately in the solution process, provides a novel link between mathematically described physiological knowledge and the clinical concept of differential diagnoses

Numerical simulations of unsteady flows past two-bladed rotors in forward-flight conditions

Energy Technology Data Exchange (ETDEWEB)

Xu, H.; Mamou, M.; Khalid, M. [National Research Council, Inst. for Aerospace Research, Ottawa, Ontario (Canada)]. E-mail: Hongyi.Xu@nrc.ca

2004-07-01

The current paper presents time-accurate numerical simulations of compressible flows past two-bladed rotor configurations using a Chimera moving grid approach. The simulations are performed for a variety of flow conditions and various blade aspect ratios. The rotor blades are rectangular, untapered and untwisted planforms. Their cross-sections are built using the NACA 0012 airfoil profile. The aerodynamic performance of the rotor is investigated using the Euler equations. The CFD-FASTRAN code was used for the computations. The pressure distributions are benchmarked against the experimental data from Caradonna and Tung and a number of previous Euler calculations by Agarwal and Deese and Chen et al. The comparisons indicate that the current simulations for the forward flight conditions can reproduce the pressure distributions on the blade surfaces and the prediction of shockwave locations with reasonably good accuracy. (author)

Numerical simulations of unsteady flows past two-bladed rotors in forward-flight conditions

International Nuclear Information System (INIS)

Xu, H.; Mamou, M.; Khalid, M.

2004-01-01

The current paper presents time-accurate numerical simulations of compressible flows past two-bladed rotor configurations using a Chimera moving grid approach. The simulations are performed for a variety of flow conditions and various blade aspect ratios. The rotor blades are rectangular, untapered and untwisted planforms. Their cross-sections are built using the NACA 0012 airfoil profile. The aerodynamic performance of the rotor is investigated using the Euler equations. The CFD-FASTRAN code was used for the computations. The pressure distributions are benchmarked against the experimental data from Caradonna and Tung and a number of previous Euler calculations by Agarwal and Deese and Chen et al. The comparisons indicate that the current simulations for the forward flight conditions can reproduce the pressure distributions on the blade surfaces and the prediction of shockwave locations with reasonably good accuracy. (author)

Developing a tool for observing group critical thinking skills in first-year medical students: a pilot study using physiology-based, high-fidelity patient simulations.

Science.gov (United States)

Nguyen, Khoa; Ben Khallouq, Bertha; Schuster, Amanda; Beevers, Christopher; Dil, Nyla; Kay, Denise; Kibble, Jonathan D; Harris, David M

2017-12-01

Most assessments of physiology in medical school use multiple choice tests that may not provide information about a student's critical thinking (CT) process. There are limited performance assessments, but high-fidelity patient simulations (HFPS) may be a feasible platform. The purpose of this pilot study was to determine whether a group's CT process could be observed over a series of HFPS. An instrument [Critical Thinking Skills Rating Instrument CTSRI)] was designed with the IDEAS framework. Fifteen groups of students participated in three HFPS that consisted of a basic knowledge quiz and introduction, HFPS session, and debriefing. HFPS were video recorded, and two raters reviewed and scored all HFPS encounters with the CTSRI independently. Interrater analysis suggested good reliability. There was a correlation between basic knowledge scores and three of the six observations on the CTSRI providing support for construct validity. The median CT ratings significantly increased for all observations between the groups' first and last simulation. However, there were still large percentages of video ratings that indicated students needed substantial prompting during the HFPS. The data from this pilot study suggest that it is feasible to observe CT skills in HFPS using the CTSRI. Based on the findings from this study, we strongly recommend that first-year medical students be competent in basic knowledge of the relevant physiology of the HFPS before participating, to minimize the risk of a poor learning experience. Copyright © 2017 the American Physiological Society.

Thermal, physiological strain index and perceptual responses in Iranian Muslim women under Thermal Condition in order to Guide in Prevention of Heat Stress

Directory of Open Access Journals (Sweden)

Peymaneh Habibi

2014-09-01

Full Text Available Heat stress risk assessment, as a harmful agent at workplace, is essential for controlling heat strain. The purpose of this study was relation between physiological and perceptual heat strain responses in Iranian veiled women under laboratory thermal conditions. This experimental study was carried out on 36 healthy females (age 22.3 ± 2.0 yr, height 162.76±5. 57cm, weight 55.82 ± 9.27kg in sitting state under thermal conditions (27 - 38° C in the hot-dry climatic condition for 120 min. In order to calculate the physiological strain index (PSI, oral temperature and heart rate were measured every 5 min. Physiological factors, and Heat Strain Score Index (HSSI questionnaires are simultaneous measurements taken at any 5 min during the exposure and physiological factors, and Heat Strain Score Index (HSSI questionnaires are the initial measurements. The data were analyzed using correlation and line regression by test spss16. The results showed that the average heart rate and oral temperature at resting and sitting were between 83.06 ±9.41bpm, 87.91 ±7.87 bpm and 36.7° C, 37. 1° C respectively. Also, the results have revealed a direct and significant and direct correlation among HSSI with WBGT (R2 = 0.97, P< 0.001, PSI (R2 = 0.96, P< 0.001, oral temperature (R2 = 0.96, P< 0.001 and heart rate (R2 = 0.62, P< 0.01 indices. The results have shown that simultaneously with the increase in valid indices of heat stress evaluation such as WBGT and PSI indices, the amount of HSSI index has also increased with high power. Therefore, it can be conclude that when there is no access to a reliable heat stress method such as WBGT or PSI indices, HSSI index, an objective and subjective heat strain method, can be used as a simple, fast and inexpensive method for evaluating the heat strain in women.

Intragroup Emotions: Physiological Linkage and Social Presence.

Science.gov (United States)

Järvelä, Simo; Kätsyri, Jari; Ravaja, Niklas; Chanel, Guillaume; Henttonen, Pentti

2016-01-01

We investigated how technologically mediating two different components of emotion-communicative expression and physiological state-to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression) and visualization of group level physiological heart rates and their dyadic linkage (physiology) was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member's physiological components of emotion by technological means to enhance mediated communication and strengthen social presence.

An Automatic Approach to the Stabilization Condition in a HIx Distillation Simulation

International Nuclear Information System (INIS)

Chang, Ji Woon; Shin, Young Joon; Lee, Ki Young; Kim, Yong Wan; Chang, Jong Hwa; Youn, Cheung

2010-01-01

In the Sulfur-Iodine(SI) thermochemical process to produce nuclear hydrogen, an H 2 O-HI-I 2 ternary mixture solution discharged from the Bunsen reaction is primarily concentrated by electro-electrodialysis. The concentrated solution is distillated in the HIx distillation column to generate a high purity HI vapor. The pure HI vapor is obtained at the top of the HIx distillation column and the diluted HIx solution is discharged at the bottom of the column. In order to simulate the steady-state HIx distillation column, a vapor-liquid equilibrium (VLE) model of the H 2 O-HI-I 2 ternary system is required and the subprogram to calculate VLE concentrations has been already introduced by KAERI research group in 2006. The steady state simulation code for the HIx distillation process was also developed in 2007. However, the intrinsic phenomena of the VLE data such as the steep slope of a T-x-y diagram caused the instability of the simulation calculation. In this paper, a computer program to automatically find a stabilization condition in the steady state simulation of the HIx distillation column is introduced. A graphic user interface (GUI) function to monitor an approach to the stabilization condition was added in this program

Survival of a microbial soil community under Martian conditions

Science.gov (United States)

Hansen, A. A.; Noernberg, P.; Merrison, J.; Lomstein, B. Aa.; Finster, K. W.

2003-04-01

Because of the similarities between Earth and Mars early history the hypothesis was forwarded that Mars is a site where extraterrestrial life might have and/or may still occur(red). Sample-return missions are planned by NASA and ESA to test this hypothesis. The enormous economic costs and the logistic challenges of these missions make earth-based model facilities inevitable. The Mars simulation system at University of Aarhus, Denmark allows microbiological experiments under Mars analogue conditions. Thus detailed studies on the effect of Mars environmental conditions on the survival and the activity of a natural microbial soil community were carried out. Changes in the soil community were determined with a suite of different approaches: 1) total microbial respiration activity was investigated with 14C-glucose, 2) the physiological profile was investigated by the EcoLog-system, 3) colony forming units were determined by plate counts and 4) the microbial diversity on the molecular level was accessed with Denaturing Gradient Gel Electrophoresis. The simulation experiments showed that a part of the bacterial community survived Martian conditions corresponding to 9 Sol. These and future simulation experiments will contribute to our understanding of the possibility for extraterrestrial and terrestrial life on Mars.

An effective absorbing layer for the boundary condition in acoustic seismic wave simulation

Science.gov (United States)

Yao, Gang; da Silva, Nuno V.; Wu, Di

2018-04-01

Efficient numerical simulation of seismic wavefields generally involves truncating the Earth model in order to keep computing time and memory requirements down. Absorbing boundary conditions, therefore, are applied to remove the boundary reflections caused by this truncation, thereby allowing for accurate modeling of wavefields. In this paper, we derive an effective absorbing boundary condition for both acoustic and elastic wave simulation, through the simplification of the damping term of the split perfectly matched layer (SPML) boundary condition. This new boundary condition is accurate, cost-effective, and easily implemented, especially for high-performance computing. Stability analysis shows that this boundary condition is effectively as stable as normal (non-absorbing) wave equations for explicit time-stepping finite differences. We found that for full-waveform inversion (FWI), the strengths of the effective absorbing layer—a reduction of the computational and memory cost coupled with a simplistic implementation—significantly outweighs the limitation of incomplete absorption of outgoing waves relative to the SPML. More importantly, we demonstrate that this limitation can easily be overcome through the use of two strategies in FWI, namely variable cell size and model extension thereby fully compensating for the imperfectness of the proposed absorbing boundary condition.

Physiological and Perceived Effects of Forearm or Head Cooling During Simulated Firefighting Activity and Rehabilitation

Science.gov (United States)

Yeargin, Susan; McKenzie, Amy L.; Eberman, Lindsey E.; Kingsley, J. Derek; Dziedzicki, David J.; Yoder, Patrick

2016-01-01

Context: Cooling devices aim to protect firefighters by attenuating a rise in body temperature. Devices for head cooling (HC) while firefighting and forearm cooling (FC) during rehabilitation (RHB) intervals are commonly marketed, but research regarding their efficacy is limited. Objective: To investigate the physiological and perceived effects of HC and FC during firefighting drills and RHB. Design: Randomized controlled clinical trial. Setting: Firefighter training center. Patients or Other Participants: Twenty-seven male career firefighters (age = 39 ± 7 years; height = 169 ± 7 cm; weight = 95.4 ± 16.8 kg). Intervention(s): Firefighters were randomly assigned to 1 condition: HC (n = 9), in which participants completed drills wearing a cold gel pack inside their helmet; FC (n = 8), in which participants sat on a collapsible chair with water-immersion arm troughs during RHB; or control (n = 10), in which participants used no cooling devices. Firefighters completed four 15-minute drills (D1−D4) wearing full bunker gear and breathing apparatus. Participants had a 15-min RHB after D2 (RHB1) and D4 (RHB2). Main Outcome Measure(s): Change (Δ) in gastrointestinal temperature (TGI), heart rate (HR), physiological strain index, and perceived thermal sensation. Results: The TGI increased similarly in the HC and control groups, respectively (D1: 0.57°C ± 0.41°C, 0.73°C ± 0.30°C; D2: 0.92°C ± 0.28°C, 0.85°C ± 0.27°C; D3: −0.37°C ± 0.34°C, −0.01°C ± 0.72°C; D4: 0.25°C ± 0.42°C, 0.57°C ± 0.26°C; P > .05). The ΔHR, Δ physiological strain index, and Δ thermal sensation were similar between the HC and control groups during drills (P > .05). The FC group demonstrated a decreased TGI compared with the control group after RHB1 (−1.61°C ± 0.35°C versus −0.23°C ± 0.34°C; P .05). Conclusions: The HC did not attenuate rises in physiological or perceptual variables during firefighting drills. The FC effectively reduced TGI and the

Simulation of CHF Condition using an Electroplating System

Energy Technology Data Exchange (ETDEWEB)

Ohk, Seung-Min; Park, Hae-Kyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

2016-10-15

Heat transfer is enhanced when the bubbles are generated on the heated surface at the nucleate boiling regime since vigorous mixing of the liquid occurs near the heated surface due to the buoyancy force of the bubbles. As this phenomenon intensified, vapor film can be formed on the heated surface and it impairs heat transfer disturbing the heat exchange between the surface and the bulk liquid. And thus, the heat flux has the certain maximum value. This maximum value, Critical Heat Flux (CHF) is generally exhibits in the pool boiling condition in non-film boiling mode. Actually, the higher heat flux could be generated at the film boiling mode with extremely high surface temperature, which may unendurable for the system structure. CHF phenomena is simulated by hydrogen gas using electroplating system in mass transfer experiment. Vapor behavior on mass transfer experiment was visualized, and it was similar to that of on the heat transfer. CHF value was simulated by hydrogen gas with isovolumetric concept. Thus, virtual heat flux was estimated by mass flux, which is a non-heating process. Difference of gas density from heat transfer and mass transfer systems were considered and revised for the simulated heat flux. Despite of the simple parametric analysis, estimated CHF value of this study was 6.6 times smaller than Zuber's.

Simulating the Probability of Grain Sorghum Maturity before the First Frost in Northeastern Colorado

Directory of Open Access Journals (Sweden)

Gregory S. McMaster

2016-09-01

Full Text Available Expanding grain sorghum [Sorghum bicolor (L. Moench] production northward from southeastern Colorado is thought to be limited by shorter growing seasons due to lower temperatures and earlier frost dates. This study used a simulation model for predicting crop phenology (PhenologyMMS to estimate the probability of reaching physiological maturity before the first fall frost for a variety of agronomic practices in northeastern Colorado. Physiological maturity for seven planting dates (1 May to 12 June, four seedbed moisture conditions affecting seedling emergence (from Optimum to Planted in Dust, and three maturity classes (Early, Medium, and Late were simulated using historical weather data from nine locations for both irrigated and dryland phenological parameters. The probability of reaching maturity before the first frost was slightly higher under dryland conditions, decreased as latitude, longitude, and elevation increased, planting date was delayed, and for later maturity classes. The results provide producers with estimates of the reliability of growing grain sorghum in northeastern Colorado.

Simulating low-flow conditions in an arctic watershed using WaSiM

Science.gov (United States)

Daanen, R. P.; Gaedeke, A.; Liljedahl, A. K.; Arp, C. D.; Whitman, M. S.; Jones, B. M.; Cai, L.; Alexeev, V. A.

2017-12-01

The goal of this study is to identify the magnitude, timing, and duration of low-flow conditions under scenarios of summer drought throughout the 4500-km2 Fish Creek watershed, which is set entirely on the Arctic Coastal Plain of northern Alaska. The hydrologic response of streams in this region to drought conditions is not well understood, but likely varies by stream size, upstream lake extent, and geologic setting. We used a physically based model, Water Balance Simulation Model (WaSiM) to simulate river discharge, surface runoff, active layer depth, soil temperatures, water levels, groundwater levels, groundwater flow, and snow distribution. We found that 7-day low flows were strongly affected by scenarios of drought or wet conditions. The 10-year-period scenarios were generated by selecting dry or wet years from a reanalysis dataset. Starting conditions for the simulations were based on a control run with average atmospheric conditions. Connectivity of lakes with better feeding conditions for fish significantly decreased in the scenarios of both summer and winter drought. The overall memory of the hydrologic network seems to be on the order of two to three years, based on the time to reach equilibrium hydrological conditions. This suggests that lake level fluctuation and water harvest could have a long-term effect on the connectivity of lakes. Climate change could strongly affect this system, and increased future water use could add more pressure on fish populations. Snowmelt is a major component of the water balance in a typical Arctic watershed and fish tend to migrate to their summer feeding lakes during the spring. Mid-summer periods without significant rainfall prove most limiting on fish movement, and during this time headwater lakes supply the majority of streamflow and are often the habitat destination for foraging fish. Models that predict connectivity of these lakes to downstream networks during low-flow conditions will help identify where lake water

Signals and Systems in Biomedical Engineering Signal Processing and Physiological Systems Modeling

CERN Document Server

Devasahayam, Suresh R

2013-01-01

The use of digital signal processing is ubiquitous in the field of physiology and biomedical engineering. The application of such mathematical and computational tools requires a formal or explicit understanding of physiology. Formal models and analytical techniques are interlinked in physiology as in any other field. This book takes a unitary approach to physiological systems, beginning with signal measurement and acquisition, followed by signal processing, linear systems modelling, and computer simulations. The signal processing techniques range across filtering, spectral analysis and wavelet analysis. Emphasis is placed on fundamental understanding of the concepts as well as solving numerical problems. Graphs and analogies are used extensively to supplement the mathematics. Detailed models of nerve and muscle at the cellular and systemic levels provide examples for the mathematical methods and computer simulations. Several of the models are sufficiently sophisticated to be of value in understanding real wor...

Extended survival of several organisms and amino acids under simulated martian surface conditions

Science.gov (United States)

Johnson, A. P.; Pratt, L. M.; Vishnivetskaya, T.; Pfiffner, S.; Bryan, R. A.; Dadachova, E.; Whyte, L.; Radtke, K.; Chan, E.; Tronick, S.; Borgonie, G.; Mancinelli, R. L.; Rothschild, L. J.; Rogoff, D. A.; Horikawa, D. D.; Onstott, T. C.

2011-02-01

Recent orbital and landed missions have provided substantial evidence for ancient liquid water on the martian surface as well as evidence of more recent sedimentary deposits formed by water and/or ice. These observations raise serious questions regarding an independent origin and evolution of life on Mars. Future missions seek to identify signs of extinct martian biota in the form of biomarkers or morphological characteristics, but the inherent danger of spacecraft-borne terrestrial life makes the possibility of forward contamination a serious threat not only to the life detection experiments, but also to any extant martian ecosystem. A variety of cold and desiccation-tolerant organisms were exposed to 40 days of simulated martian surface conditions while embedded within several centimeters of regolith simulant in order to ascertain the plausibility of such organisms' survival as a function of environmental parameters and burial depth. Relevant amino acid biomarkers associated with terrestrial life were also analyzed in order to understand the feasibility of detecting chemical evidence for previous biological activity. Results indicate that stresses due to desiccation and oxidation were the primary deterrent to organism survival, and that the effects of UV-associated damage, diurnal temperature variations, and reactive atmospheric species were minimal. Organisms with resistance to desiccation and radiation environments showed increased levels of survival after the experiment compared to organisms characterized as psychrotolerant. Amino acid analysis indicated the presence of an oxidation mechanism that migrated downward through the samples during the course of the experiment and likely represents the formation of various oxidizing species at mineral surfaces as water vapor diffused through the regolith. Current sterilization protocols may specifically select for organisms best adapted to survival at the martian surface, namely species that show tolerance to radical

Comparative investigation of physiological responses of field-grown ...

African Journals Online (AJOL)

An important consideration in designing and managing forage systems is the knowledge of the physiological response mechanisms to cutting, especially when water deficit conditions are prevailing. The objective of this study was to determine the physiological response of Medicago sativa and Festuca arundinacea to ...

Physiological intracellular crowdedness is defined by perimeter to area ratio of subcellular compartments

Directory of Open Access Journals (Sweden)

Noriko eHiroi

2012-07-01

Full Text Available The intracellular environment is known to be a crowded and inhomogeneous space. Such an in vivo environment differs from a well-diluted, homogeneous environment for biochemical reactions. However, the effects of both crowdedness and the inhomogeneity of environment on the behavior of a mobile particle have not yet been investigated sufficiently. As described in this paper, we constructed artificial reaction spaces with fractal models, which are assumed to be non-reactive solid obstacles in a reaction space with crevices that function as operating ranges for mobile particles threading the space. Because of the homogeneity of the structures of artificial reaction spaces, the models succeeded in reproducing the physiological fractal dimension of solid structures with a smaller number of non-reactive obstacles than in the physiological condition. This incomplete compatibility was mitigated when we chose a suitable condition of a perimeter-to-area ratio of the operating range to our model. Our results also show that a simulation space is partitioned into convenient reaction compartments as an in vivo environment with the exact amount of solid structures estimated from TEM images. The characteristics of these compartments engender larger mean square displacement of a mobile particle than that of particles in smaller compartments. Subsequently, the particles start to show confined particle-like behavior. These results are compatible with our previously presented results, which predicted that a physiological environment would produce quick-response and slow-exhaustion reactions.

Effects of simulated domestic and international air travel on sleep, performance, and recovery for team sports.

Science.gov (United States)

Fowler, P; Duffield, R; Vaile, J

2015-06-01

The present study examined effects of simulated air travel on physical performance. In a randomized crossover design, 10 physically active males completed a simulated 5-h domestic flight (DOM), 24-h simulated international travel (INT), and a control trial (CON). The mild hypoxia, seating arrangements, and activity levels typically encountered during air travel were simulated in a normobaric, hypoxic altitude room. Physical performance was assessed in the afternoon of the day before (D - 1 PM) and in the morning (D + 1 AM) and afternoon (D + 1 PM) of the day following each trial. Mood states and physiological and perceptual responses to exercise were also examined at these time points, while sleep quantity and quality were monitored throughout each condition. Sleep quantity and quality were significantly reduced during INT compared with CON and DOM (P  0.05). Compared with baseline, physiological and perceptual responses to exercise, and mood states were exacerbated following the INT trial (P sleep disruption during travel and the subsequent exacerbated physiological and perceptual markers of fatigue. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Generalized Sheet Transition Condition FDTD Simulation of Metasurface

Science.gov (United States)

Vahabzadeh, Yousef; Chamanara, Nima; Caloz, Christophe

2018-01-01

We propose an FDTD scheme based on Generalized Sheet Transition Conditions (GSTCs) for the simulation of polychromatic, nonlinear and space-time varying metasurfaces. This scheme consists in placing the metasurface at virtual nodal plane introduced between regular nodes of the staggered Yee grid and inserting fields determined by GSTCs in this plane in the standard FDTD algorithm. The resulting update equations are an elegant generalization of the standard FDTD equations. Indeed, in the limiting case of a null surface susceptibility ($\\chi_\\text{surf}=0$), they reduce to the latter, while in the next limiting case of a time-invariant metasurface $[\\chi_\\text{surf}\

The physiological effects of oil, dispersant and dispersed oil on the bay mussel, Mytilus trossulus, in Arctic/Subarctic conditions.

Science.gov (United States)

Counihan, Katrina L

2018-06-01

Increasing oil development around Alaska and other Arctic regions elevates the risk for another oil spill. Dispersants are used to mitigate the impact of an oil spill by accelerating natural degradation processes, but the reduced hydrophobicity of dispersed oil may increase its bioavailability to marine organisms. There is limited research on the effect of dispersed oil on cold water species and ecosystems. Therefore, spiked exposure tests were conducted with bay mussels (Mytilus trossulus) in seawater with non-dispersed oil, Corexit 9500 and oil dispersed with different concentrations of Corexit 9500. After three weeks of exposure, acute and chronic physiological impacts were determined. The majority of physiological responses occurred during the first seven days of exposure, with mussels exhibiting significant cytochrome P450 activity, superoxide dismutase activity and heat shock protein levels. Mussels exposed to non-dispersed oil also experienced immune suppression, reduced transcription and higher levels of mortality. After 21 days, mussels in all treatments exhibited evidence of genetic damage, tissue loss and a continued stress response. Bay mussels are useful as indicators of ecosystem health and recovery, and this study was an important step in understanding how non-dispersed oil, dispersant and dispersed oil affect the physiology of this sentinel species in Arctic/subarctic conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

The Impact of Preparation: Conditions for Developing Professional Knowledge through Simulations

Science.gov (United States)

Sjöberg, David; Karp, Staffan; Söderström, Tor

2015-01-01

This article examines simulations of critical incidents in police education by investigating how activities in the preparation phase influence participants' actions and thus the conditions for learning professional knowledge. The study is based on interviews in two stages (traditional and stimulated recall interviews) with six selected students…

Intragroup emotions: physiological linkage and social presence

Directory of Open Access Journals (Sweden)

Simo eJärvelä

2016-02-01

Full Text Available We investigated how technologically mediating two different components of emotion – communicative expression and physiological state – to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression and visualization of group level physiological heart rates and their dyadic linkage (physiology was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member’s physiological components of emotion by technological means to enhance mediated communication and strengthen social presence.

Intragroup Emotions: Physiological Linkage and Social Presence

Science.gov (United States)

Järvelä, Simo; Kätsyri, Jari; Ravaja, Niklas; Chanel, Guillaume; Henttonen, Pentti

2016-01-01

We investigated how technologically mediating two different components of emotion—communicative expression and physiological state—to group members affects physiological linkage and self-reported feelings in a small group during video viewing. In different conditions the availability of second screen text chat (communicative expression) and visualization of group level physiological heart rates and their dyadic linkage (physiology) was varied. Within this four person group two participants formed a physically co-located dyad and the other two were individually situated in two separate rooms. We found that text chat always increased heart rate synchrony but HR visualization only with non-co-located dyads. We also found that physiological linkage was strongly connected to self-reported social presence. The results encourage further exploration of the possibilities of sharing group member's physiological components of emotion by technological means to enhance mediated communication and strengthen social presence. PMID:26903913

Physiological and Environmental Sensor Skin Stamp

Data.gov (United States)

National Aeronautics and Space Administration — Future exploration missions will require astronauts to autonomously monitor physiological and atmospheric conditions. Recent technological advances in the developing...

CFD simulation of pressure and discharge surge in Francis turbine at off-design conditions

International Nuclear Information System (INIS)

Chirkov, D; Avdyushenko, A; Panov, L; Bannikov, D; Cherny, S; Skorospelov, V; Pylev, I

2012-01-01

A hybrid 1D-3D CFD model is developed for the numerical simulation of pressure and discharge surge in hydraulic power plants. The most essential part – the turbine itself – is simulated directly using 3D unsteady equations of turbulent motion of fluid-vapor mixture, while the rest of the hydraulic system is simulated in frames of 1D hydro-acoustic model. Thus the model accounts for the main factors responsible for excitation and propagation of pressure and discharge waves in hydraulic power plant. Boundary conditions at penstock inlet and draft tube outlet are discussed in detail. Then simulations of dynamic behavior at part load and full load operating points are performed. It is shown that the numerical model is able to capture self-excited oscillations in full load conditions. The influence of penstock length and flow structure behind the runner are investigated. The presented approach seems to be a promising tool for prediction and investigation the dynamic behavior in hydraulic power plants.

Forty years experience in developing and using rainfall simulators under tropical and Mediterranean conditions

Science.gov (United States)

Pla-Sentís, Ildefonso; Nacci, Silvana

2010-05-01

Rainfall simulation has been used as a practical tool for evaluating the interaction of falling water drops on the soil surface, to measure both stability of soil aggregates to drop impact and water infiltration rates. In both cases it is tried to simulate the effects of natural rainfall, which usually occurs at very different, variable and erratic rates and intensities. One of the main arguments against the use of rainfall simulators is the difficulty to reproduce the size, final velocity and kinetic energy of the drops in natural rainfall. Since the early 70´s we have been developing and using different kinds of rainfall simulators, both at laboratory and field levels, and under tropical and Mediterranean soil and climate conditions, in flat and sloping lands. They have been mainly used to evaluate the relative effects of different land use and management, including different cropping systems, tillage practices, surface soil conditioning, surface covers, etc. on soil water infiltration, on runoff and on erosion. Our experience is that in any case it is impossible to reproduce the variable size distribution and terminal velocity of raindrops, and the variable changes in intensity of natural storms, under a particular climate condition. In spite of this, with the use of rainfall simulators it is possible to obtain very good information, which if it is properly interpreted in relation to each particular condition (land and crop management, rainfall characteristics, measurement conditions, etc.) may be used as one of the parameters for deducing and modelling soil water balance and soil moisture regime under different land use and management and variable climate conditions. Due to the possibility for a better control of the intensity of simulated rainfall and of the size of water drops, and the possibility to make more repeated measurements under very variable soil and land conditions, both in the laboratory and specially in the field, the better results have been

Equilibrium Dynamics of β-N-Methylamino-L-Alanine (BMAA) and Its Carbamate Adducts at Physiological Conditions

Science.gov (United States)

Zimmerman, David; Goto, Joy J.; Krishnan, Viswanathan V

2016-01-01

Elevated incidences of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia complex (ALS/PDC) is associated with β-methylamino-L-alanine (BMAA), a non-protein amino acid. In particular, the native Chamorro people living in the island of Guam were exposed to BMAA by consuming a diet based on the cycad seeds. Carbamylated forms of BMAA are glutamate analogues. The mechanism of neurotoxicity of the BMAA is not completely understood, and BMAA acting as a glutamate receptor agonist may lead to excitotoxicity that interferes with glutamate transport systems. Though the interaction of BMAA with bicarbonate is known to produce carbamate adducts, here we demonstrate that BMAA and its primary and secondary adducts coexist in solution and undergoes a chemical exchange among them. Furthermore, we determined the rates of formation/cleavage of the carbamate adducts under equilibrium conditions using two-dimensional proton exchange NMR spectroscopy (EXSY). The coexistence of the multiple forms of BMAA at physiological conditions adds to the complexity of the mechanisms by which BMAA functions as a neurotoxin. PMID:27513925

Equilibrium Dynamics of β-N-Methylamino-L-Alanine (BMAA and Its Carbamate Adducts at Physiological Conditions.

Directory of Open Access Journals (Sweden)

David Zimmerman

Full Text Available Elevated incidences of Amyotrophic Lateral Sclerosis/Parkinsonism Dementia complex (ALS/PDC is associated with β-methylamino-L-alanine (BMAA, a non-protein amino acid. In particular, the native Chamorro people living in the island of Guam were exposed to BMAA by consuming a diet based on the cycad seeds. Carbamylated forms of BMAA are glutamate analogues. The mechanism of neurotoxicity of the BMAA is not completely understood, and BMAA acting as a glutamate receptor agonist may lead to excitotoxicity that interferes with glutamate transport systems. Though the interaction of BMAA with bicarbonate is known to produce carbamate adducts, here we demonstrate that BMAA and its primary and secondary adducts coexist in solution and undergoes a chemical exchange among them. Furthermore, we determined the rates of formation/cleavage of the carbamate adducts under equilibrium conditions using two-dimensional proton exchange NMR spectroscopy (EXSY. The coexistence of the multiple forms of BMAA at physiological conditions adds to the complexity of the mechanisms by which BMAA functions as a neurotoxin.

Survival of Lactobacillus delbrueckii UFV H2b20 in fermented milk under simulated gastric and intestinal conditions.

Science.gov (United States)

da Conceição, L L; Leandro, E S; Freitas, F S; de Oliveira, M N V; Ferreira-Machado, A B; Borges, A C; de Moraes, C A

2013-09-01

The survival of Lactobacillus delbrueckii UFV H2b20 was assessed in fermented milk, both during the storage period and after exposure to simulated gastric and intestinal juices, as well the detection of the gene fbpA involved in adherence to human gastrointestinal tract. L. delbrueckii UFV H2b20 remained stable and viable for 28 days under refrigerated storage conditions. After one day of storage, that strain exhibited a one-log population reduction following exposure in tandem to simulated gastric and intestinal juices. After 14 days of storage, a two-log reduction was observed following 90 min of exposure to the simulated gastric conditions. However, the strain did not survive following exposure to the simulated intestinal juice. The observed tolerance to storage conditions and resistance to the simulated gastric and intestinal conditions confirm the potential use of L. delbrueckii UFV H2b20 as a probiotic, which is further reinforced by the detection of fbpA in this strain.

Effects of baseline conditions on the simulated hydrologic response to projected climate change

Science.gov (United States)

Koczot, Kathryn M.; Markstrom, Steven L.; Hay, Lauren E.

2011-01-01

Changes in temperature and precipitation projected from five general circulation models, using one late-twentieth-century and three twenty-first-century emission scenarios, were downscaled to three different baseline conditions. Baseline conditions are periods of measured temperature and precipitation data selected to represent twentieth-century climate. The hydrologic effects of the climate projections are evaluated using the Precipitation-Runoff Modeling System (PRMS), which is a watershed hydrology simulation model. The Almanor Catchment in the North Fork of the Feather River basin, California, is used as a case study. Differences and similarities between PRMS simulations of hydrologic components (i.e., snowpack formation and melt, evapotranspiration, and streamflow) are examined, and results indicate that the selection of a specific time period used for baseline conditions has a substantial effect on some, but not all, hydrologic variables. This effect seems to be amplified in hydrologic variables, which accumulate over time, such as soil-moisture content. Results also indicate that uncertainty related to the selection of baseline conditions should be evaluated using a range of different baseline conditions. This is particularly important for studies in basins with highly variable climate, such as the Almanor Catchment.

Numerical ductile tearing simulation of circumferential cracked pipe tests under dynamic loading conditions

Energy Technology Data Exchange (ETDEWEB)

Nam, Hyun Suk; Kim, Ji Soo; Ryu, Ho Wan; Kim, Yun Jae [Dept. of Mechanical Engineering, Korea University, Seoul (Korea, Republic of); Kim, Jin Weon [Dept. of Nuclear Engineering, Chosun University, Gwangju (Korea, Republic of)

2016-10-15

This paper presents a numerical method to simulate ductile tearing in cracked components under high strain rates using finite element damage analysis. The strain rate dependence on tensile properties and multiaxial fracture strain is characterized by the model developed by Johnson and Cook. The damage model is then defined based on the ductility exhaustion concept using the strain rate dependent multiaxial fracture strain concept. The proposed model is applied to simulate previously published three cracked pipe bending test results under two different test speed conditions. Simulated results show overall good agreement with experimental results.

Effect of heat on firefighters' work performance and physiology.

Science.gov (United States)

Larsen, Brianna; Snow, Rodney; Aisbett, Brad

2015-10-01

Wildland firefighters often perform their duties under both hot and mild ambient temperatures. However, the direct impact of different ambient temperatures on firefighters' work performance has not been quantified. This study compared firefighters' work performance and physiology during simulated wildland firefighting work in hot (HOT; 32°C, 43% RH) and temperate (CON; 19°C, 56% RH) conditions. Firefighters (n=38), matched and allocated to either the CON (n=18) or HOT (n=20) condition, performed simulated self-paced wildland fire suppression tasks (e.g., hose rolling/dragging, raking) in firefighting clothing for six hours, separated by dedicated rest breaks. Task repetitions were counted (and converted to distance or area). Core temperature (Tc), skin temperature (Tsk), and heart rate were recorded continuously throughout the protocol. Urine output was measured before and during the protocol, and urine specific gravity (USG) analysed, to estimate hydration. Ad libitum fluid intake was also recorded. There were no differences in overall work output between conditions for any physical task. Heart rate was higher in the HOT (55±2% HRmax) compared to the CON condition (51±2% HRmax) for the rest periods between bouts, and for the static hose hold task (69±3% HRmax versus 65±3% HRmax). Tc and Tsk were 0.3±0.1°C and 3.1±0.2°C higher in the HOT compared to the CON trial. Both pre- and within- shift fluid intake were increased two-fold in the heat, and participants in the heat recorded lower USG results than their CON counterparts. There was no difference between the CON and HOT conditions in terms of their work performance, and firefighters in both experimental groups increased their work output over the course of the simulated shift. Though significantly hotter, participants in the heat also managed to avoid excessive cardiovascular and thermal strain, likely aided by the frequent rest breaks in the protocol, and through doubling their fluid intake. Therefore

An alternative phase-space distribution to sample initial conditions for classical dynamics simulations

International Nuclear Information System (INIS)

Garcia-Vela, A.

2002-01-01

A new quantum-type phase-space distribution is proposed in order to sample initial conditions for classical trajectory simulations. The phase-space distribution is obtained as the modulus of a quantum phase-space state of the system, defined as the direct product of the coordinate and momentum representations of the quantum initial state. The distribution is tested by sampling initial conditions which reproduce the initial state of the Ar-HCl cluster prepared by ultraviolet excitation, and by simulating the photodissociation dynamics by classical trajectories. The results are compared with those of a wave packet calculation, and with a classical simulation using an initial phase-space distribution recently suggested. A better agreement is found between the classical and the quantum predictions with the present phase-space distribution, as compared with the previous one. This improvement is attributed to the fact that the phase-space distribution propagated classically in this work resembles more closely the shape of the wave packet propagated quantum mechanically

Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

International Nuclear Information System (INIS)

Wang, Haitao; Han, En-Hou

2017-01-01

The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

Numerical Simulation of Interactions between Corrosion Pits on Stainless Steel under Loading Conditions

Energy Technology Data Exchange (ETDEWEB)

Wang, Haitao; Han, En-Hou [Chinese Academy of Sciences, Shenyang (China)

2017-04-15

The interactions between corrosion pits on stainless steel under loading conditions are studied by using a cellular automata model coupled with finite element method at a mesoscopic scale. The cellular automata model focuses on a metal/film/electrolyte system, including anodic dissolution, passivation, diffusion of hydrogen ions and salt film hydrolysis. The Chopard block algorithm is used to improve the diffusion simulation efficiency. The finite element method is used to calculate the stress concentration on the pit surface during pit growth, and the effect of local stress and strain on anodic current is obtained by using the Gutman model, which is used as the boundary conditions of the cellular automata model. The transient current characteristics of the interactions between corrosion pits under different simulation factors including the breakdown of the passive film at the pit mouth and the diffusion of hydrogen ions are analyzed. The analysis of the pit stability product shows that the simulation results are close to the experimental conclusions.

Evaluating the Effect of Seed Treatment with Hydrogen Peroxide on Anatomical and Physiological Characteristics of Wheat under Dry Condition

Directory of Open Access Journals (Sweden)

T Jafarian

2017-12-01

Full Text Available Introduction Water deficit is the major abiotic factor limiting plant growth and crop productivity around the world. In all agricultural regions, yields of rain-fed crops are periodically reduced by drought. Among various strategies, pre-sowing treatment and priming of seeds are easy, low cost, low risk and effective approaches to overcome the environmental stress problems. Various priming strategies include osmopriming, halopriming, hormonal priming or hydropriming, etc. Hydrogen peroxide, a stress signal molecule, was evaluated as seed treatment to produce the metabolic changes, which could lead to improved drought tolerance in wheat. The interaction of signals conferring stress tolerance in accomplishing better crop growth and yield is a priority area of research. Here we report some anatomical, physiological and biochemical changes induced by Hydrogen peroxide during seed treatment and their involvement in conferring drought tolerance upon wheat. Materials and Methods A field study was conducted out at the research farm of agricultural collage of Ilam university during 2014-2015 cropping season. This study was aimed to investigate the priming seed with hydrogen peroxide on two wheat genotypes (Cross Sabalan (bread wheat and Saji (durum wheat, under dryland farming system condition. Experimental design was factorial, arranged in randomized complete block, with three replications. Two main factors were wheat genotypes and four soaking treatments of seeds with different concentration (zero, 25, 50 and 80 Mm of Hydrogen Peroxide. Seeds of each genotype were sown at 6 rows of 3 m length with lines space of 20 cm in depth 5 cm. At heading stage physiological traits were measured on selected leaves and then samples were taken to determine leaf area, Leaf rolling, number and length of Stomata on the epidermis, RWC, electrolyte leakage, photosynthetic pigments concentrations (Chla, b and carotenoid and antioxidant enzyme contents (catalase, ascorbate

Physiological Studies of Arctic Carnivores.

Science.gov (United States)

1982-12-01

All transmitters were maintained in a cold sterilant ( benzalkonium chloride ) until implanted in a bear. Radio-transmitters for monitoring temperature...body was unknown, particularly during the winter when bears are in dens and there is a generalized reduction in metabolism and other physiological... reduction in core body temperature from summer to winter closely agrees with those reported earlier for bears maintained in captivity under simulated

Physiological responses and energy cost during a simulation of a Muay Thai boxing match.

Science.gov (United States)

Crisafulli, Antonio; Vitelli, Stefano; Cappai, Ivo; Milia, Raffaele; Tocco, Filippo; Melis, Franco; Concu, Alberto

2009-04-01

Muay Thai is a martial art that requires complex skills and tactical excellence for success. However, the energy demand during a Muay Thai competition has never been studied. This study was devised to obtain an understanding of the physiological capacities underlying Muay Thai performance. To that end, the aerobic energy expenditure and the recruitment of anaerobic metabolism were assessed in 10 male athletes during a simulation match of Muay Thai. Subjects were studied while wearing a portable gas analyzer, which was able to provide data on oxygen uptake, carbon dioxide production, and heart rate (HR). The excess of CO2 production (CO2 excess) was also measured to obtain an index of anaerobic glycolysis. During the match, group energy expenditure was, on average (mean +/- standard error of the mean), 10.75 +/- 1.58 kcal.min-1, corresponding to 9.39 +/- 1.38 metabolic equivalents. Oxygen uptake and HRs were always above the level of the anaerobic threshold assessed in a preliminary incremental test. CO2 excess showed an abrupt increase in the first round, and reached a value of 636 +/- 66.5 mL.min-1. This parameter then gradually decreased throughout the simulation match. These data suggest that Muay Thai is a physically demanding activity with great involvement of both the aerobic metabolism and anaerobic glycolysis. In particular, it appears that, after an initial burst of anaerobic glycolysis, there was a progressive increase in the aerobic energy supply. Thus, training protocols should include exercises that train both aerobic and anaerobic energetic pathways.

Uropathogenic Escherichia coli Express Type 1 Fimbriae Only in Surface Adherent Populations Under Physiological Growth Conditions

DEFF Research Database (Denmark)

Stærk, Kristian; Kolmos, Hans Jørn; Khandige, Surabhi

2016-01-01

were correlated with the ability to adhere to and invade cultured human bladder cells. RESULTS:  Although inactive during planktonic growth in urine, T1F expression occurs when UPEC settles on and infects bladder epithelial cells or colonizes catheters. As a result, UPEC in these sessile populations...... with increased expression during surface growth adaptation and infection of uroepithelial cells. This leads to separation of UPEC into low-expression planktonic populations and high-expression sessile populations....... enhances bladder cell adhesion and invasion potential. Only T1F-negative UPEC are subsequently released to the urine, thus limiting T1F expression to surface-associated UPEC alone. CONCLUSION:  Our results demonstrate that T1F expression is strictly regulated under physiological growth conditions...

Proton-coupled electron transfer promotes the reduction of ferrylmyoglobin by uric acid under physiological conditions

DEFF Research Database (Denmark)

de Zawadzki, Andressa; Cardoso, Daniel R.; Skibsted, Leif Horsfelt

2017-01-01

The hypervalent muscle pigment ferrylmyoglobin, MbFe(IV)]O, is not reduced by urate monoanions at physiological conditions despite a strong driving force of around 30 kJ mol1 while for low pH, uric acid was found to reduce protonated ferrylmyoglobin, MbFe(IV)]O,H+, efficiently in a bimolecular...... reaction with k1 ¼ 1.1 0.1 103 L mol1 s1, DH‡ ¼ 66.1 0.1 kJ mol1 and DS‡ ¼ 35.2 0.2 J mol1 K1. For intermediate pH, like for anaerobic muscles and for meat, proton-oupled electron transfer occurs in a transition state, {MbFe(IV)]O/H+/urate}‡, which is concluded to be formed from uric acid and Mb...... in uric acid concentration may serve as an inherent protection against radical formation by ferrylmyoglobin...

Effect of microgravity simulation using 3D clinostat on cavendish banana (Musa acuminata AAA Group) ripening process

Science.gov (United States)

Dwivany, Fenny Martha; Esyanti, Rizkita R.; Prapaisie, Adeline; Puspa Kirana, Listya; Latief, Chunaeni; Ginaldi, Ari

2016-11-01

The objective of the research was to determine the effect of microgravity simulation by 3D clinostat on Cavendish banana (Musa acuminata AAA group) ripening process. In this study, physical, physiological changes as well as genes expression were analysed. The result showed that in microgravity simulation condition ripening process in banana was delayed and the MaACOl, MaACSl and MaACS5 gene expression were affected.

Pilot points method for conditioning multiple-point statistical facies simulation on flow data

Science.gov (United States)

Ma, Wei; Jafarpour, Behnam

2018-05-01

We propose a new pilot points method for conditioning discrete multiple-point statistical (MPS) facies simulation on dynamic flow data. While conditioning MPS simulation on static hard data is straightforward, their calibration against nonlinear flow data is nontrivial. The proposed method generates conditional models from a conceptual model of geologic connectivity, known as a training image (TI), by strategically placing and estimating pilot points. To place pilot points, a score map is generated based on three sources of information: (i) the uncertainty in facies distribution, (ii) the model response sensitivity information, and (iii) the observed flow data. Once the pilot points are placed, the facies values at these points are inferred from production data and then are used, along with available hard data at well locations, to simulate a new set of conditional facies realizations. While facies estimation at the pilot points can be performed using different inversion algorithms, in this study the ensemble smoother (ES) is adopted to update permeability maps from production data, which are then used to statistically infer facies types at the pilot point locations. The developed method combines the information in the flow data and the TI by using the former to infer facies values at selected locations away from the wells and the latter to ensure consistent facies structure and connectivity where away from measurement locations. Several numerical experiments are used to evaluate the performance of the developed method and to discuss its important properties.

Realizability conditions for the turbulent stress tensor in large-eddy simulation

NARCIS (Netherlands)

Vreman, A.W.; Geurts, Bernardus J.; Kuerten, Johannes G.M.

1994-01-01

The turbulent stress tensor in large-eddy simulation is examined from a theoretical point of view. Realizability conditions for the components of this tensor are derived, which hold if and only if the filter function is positive. The spectral cut-off, one of the filters frequently used in large-eddy

Highly Integrated MEMS-ASIC Sensing System for Intracorporeal Physiological Condition Monitoring.

Science.gov (United States)

Xue, Ning; Wang, Chao; Liu, Cunxiu; Sun, Jianhai

2018-01-02

In this paper, a highly monolithic-integrated multi-modality sensor is proposed for intracorporeal monitoring. The single-chip sensor consists of a solid-state based temperature sensor, a capacitive based pressure sensor, and an electrochemical oxygen sensor with their respective interface application-specific integrated circuits (ASICs). The solid-state-based temperature sensor and the interface ASICs were first designed and fabricated based on a 0.18-μm 1.8-V CMOS (complementary metal-oxide-semiconductor) process. The oxygen sensor and pressure sensor were fabricated by the standard CMOS process and subsequent CMOS-compatible MEMS (micro-electromechanical systems) post-processing. The multi-sensor single chip was completely sealed by the nafion, parylene, and PDMS (polydimethylsiloxane) layers for biocompatibility study. The size of the compact sensor chip is only 3.65 mm × 1.65 mm × 0.72 mm. The functionality, stability, and sensitivity of the multi-functional sensor was tested ex vivo. Cytotoxicity assessment was performed to verify that the bio-compatibility of the device is conforming to the ISO 10993-5:2009 standards. The measured sensitivities of the sensors for the temperature, pressure, and oxygen concentration are 10.2 mV/°C, 5.58 mV/kPa, and 20 mV·L/mg, respectively. The measurement results show that the proposed multi-sensor single chip is suitable to sense the temperature, pressure, and oxygen concentration of human tissues for intracorporeal physiological condition monitoring.

Detailed simulations of lighting conditions in office rooms lit by daylight and artificial light

DEFF Research Database (Denmark)

Iversen, Anne

In this thesis the effect on the annual artificial lighting demand is investigated by employing detailed simulations of lighting conditions in office rooms lit by daylight and artificial. The simulations of the artificial lighting demand is accomplished through daylight simulations in Radiance....... The detailed simulations includes studies of the resolution of different weather data sets in climate-based daylight modeling. Furthermore, influence of the electrical lighting demand by simulating with dynamic occupancy patterns is studied. Finally the thesis explores the influence of obstructions in an urban...... canyon on the daylight availability within the buildings, and hence on the energy consumption for artificial lights. The results from the thesis demonstrates that the effect on the outcome of the daylight simulations when simulating with typical weather data files for the location of Copenhagen...

Physiological responses in barley to applications of lanthanum

International Nuclear Information System (INIS)

Reddy, N.; Maheswaran, J.; Peverill, K.; Meehan, B.

1998-01-01

Full text: Chinese research and glasshouse investigations carried out in Victoria by the authors have shown that several plant species, when treated with Rare Earth Elements (REEs), retain greater amounts of moisture under water stressed conditions. The physiological adaptation of the plant to retain moisture in response to REE treatment however, has not been investigated. A glasshouse trial is currently in progress to study the physiological and agronomic responses of barley (cv. Schooner) grown in pots to application of lanthanum (0, 5 and 10 kg/ha), at a concentration of 0.05%, under well-watered (field capacity) and water-deficit (25 - 30% field capacity) conditions. Lanthanum was applied both directly to the soil and as a foliar spray. The physiological measurements include, photosynthetic rate, leaf water potential, osmotic potential, relative water content, stomatal conductance and water use efficiency. Measured agronomic parameters include plant height, tiller production, leaf area development, total grain weight, total biomass, root and shoot ratio and harvest index. Analysis of plant tissue for N, P, K, Ca, Mg, Zn and La to study the relationship between application of REE and nutrient uptake is also being carried out. The paper discusses physiological and agronomic changes in barley plants in response to treatment with lanthanum, under conditions of water stress

Perinatal broiler physiology between hatching and chick collection in 2 hatching systems

NARCIS (Netherlands)

Ven, van de L.J.F.; Wagenberg, van A.V.; Decuypere, E.; Kemp, B.; Brand, van den H.

2013-01-01

Little is known about physiological responses of early- versus late-hatching chicks to early posthatch conditions in broiler practice. We investigated effects of hatching time on perinatal broiler physiology in 2 hatching systems, differing in conditions: a conventional hatcher, where chicks are

Electroformation of Giant Unilamellar Vesicles from Native Membranes and Organic Lipid Mixtures for the Study of Lipid Domains under Physiological Ionic-Strength Conditions

DEFF Research Database (Denmark)

Montes, Ruth; Ahyayauch, Hasna; Ibarguren, Maitane

2010-01-01

Giant unilamellar vesicles (GUVs) constitute a cell-sized model membrane system that allows direct visualization of particular membrane-related phenomena, such as domain formation, at the level of single vesicles using fluorescence microscopy-related techniques. Currently available protocols...... for the preparation of GUVs work only at very low salt concentrations, thus precluding experimentation under physiological conditions. In addition, the GUVs thus obtained lack membrane compositional asymmetry. Here we show how to prepare GUVs using a new protocol based on the electroformation method either from...... native membranes or organic lipid mixtures at physiological ionic strength. Additionally, we describe methods to test whether membrane proteins and glycosphingolipids preserve their natural orientation after electroformation of GUVs composed of native membranes...

Perturbations in the initial soil moisture conditions: Impacts on hydrologic simulation in a large river basin

Science.gov (United States)

Niroula, Sundar; Halder, Subhadeep; Ghosh, Subimal

2018-06-01

Real time hydrologic forecasting requires near accurate initial condition of soil moisture; however, continuous monitoring of soil moisture is not operational in many regions, such as, in Ganga basin, extended in Nepal, India and Bangladesh. Here, we examine the impacts of perturbation/error in the initial soil moisture conditions on simulated soil moisture and streamflow in Ganga basin and its propagation, during the summer monsoon season (June to September). This provides information regarding the required minimum duration of model simulation for attaining the model stability. We use the Variable Infiltration Capacity model for hydrological simulations after validation. Multiple hydrologic simulations are performed, each of 21 days, initialized on every 5th day of the monsoon season for deficit, surplus and normal monsoon years. Each of these simulations is performed with the initial soil moisture condition obtained from long term runs along with positive and negative perturbations. The time required for the convergence of initial errors is obtained for all the cases. We find a quick convergence for the year with high rainfall as well as for the wet spells within a season. We further find high spatial variations in the time required for convergence; the region with high precipitation such as Lower Ganga basin attains convergence at a faster rate. Furthermore, deeper soil layers need more time for convergence. Our analysis is the first attempt on understanding the sensitivity of hydrological simulations of Ganga basin on initial soil moisture conditions. The results obtained here may be useful in understanding the spin-up requirements for operational hydrologic forecasts.

Better Than Nothing: A Rational Approach for Minimizing the Impact of Outflow Strategy on Cerebrovascular Simulations.

Science.gov (United States)

Chnafa, C; Brina, O; Pereira, V M; Steinman, D A

2018-02-01

Computational fluid dynamics simulations of neurovascular diseases are impacted by various modeling assumptions and uncertainties, including outlet boundary conditions. Many studies of intracranial aneurysms, for example, assume zero pressure at all outlets, often the default ("do-nothing") strategy, with no physiological basis. Others divide outflow according to the outlet diameters cubed, nominally based on the more physiological Murray's law but still susceptible to subjective choices about the segmented model extent. Here we demonstrate the limitations and impact of these outflow strategies, against a novel "splitting" method introduced here. With our method, the segmented lumen is split into its constituent bifurcations, where flow divisions are estimated locally using a power law. Together these provide the global outflow rate boundary conditions. The impact of outflow strategy on flow rates was tested for 70 cases of MCA aneurysm with 0D simulations. The impact on hemodynamic indices used for rupture status assessment was tested for 10 cases with 3D simulations. Differences in flow rates among the various strategies were up to 70%, with a non-negligible impact on average and oscillatory wall shear stresses in some cases. Murray-law and splitting methods gave flow rates closest to physiological values reported in the literature; however, only the splitting method was insensitive to arbitrary truncation of the model extent. Cerebrovascular simulations can depend strongly on the outflow strategy. The default zero-pressure method should be avoided in favor of Murray-law or splitting methods, the latter being released as an open-source tool to encourage the standardization of outflow strategies. © 2018 by American Journal of Neuroradiology.

Physiological and behavioral reactions elicited by simulated and real-life visual and acoustic helicopter stimuli in dairy goats

Science.gov (United States)

2011-01-01

Background Anecdotal reports and a few scientific publications suggest that flyovers of helicopters at low altitude may elicit fear- or anxiety-related behavioral reactions in grazing feral and farm animals. We investigated the behavioral and physiological stress reactions of five individually housed dairy goats to different acoustic and visual stimuli from helicopters and to combinations of these stimuli under controlled environmental (indoor) conditions. The visual stimuli were helicopter animations projected on a large screen in front of the enclosures of the goats. Acoustic and visual stimuli of a tractor were also presented. On the final day of the study the goats were exposed to two flyovers (altitude 50 m and 75 m) of a Chinook helicopter while grazing in a pasture. Salivary cortisol, behavior, and heart rate of the goats were registered before, during and after stimulus presentations. Results The goats reacted alert to the visual and/or acoustic stimuli that were presented in their room. They raised their heads and turned their ears forward in the direction of the stimuli. There was no statistically reliable rise of the average velocity of moving of the goats in their enclosure and no increase of the duration of moving during presentation of the stimuli. Also there was no increase in heart rate or salivary cortisol concentration during the indoor test sessions. Surprisingly, no physiological and behavioral stress responses were observed during the flyover of a Chinook at 50 m, which produced a peak noise of 110 dB. Conclusions We conclude that the behavior and physiology of goats are unaffected by brief episodes of intense, adverse visual and acoustic stimulation such as the sight and noise of overflying helicopters. The absence of a physiological stress response and of elevated emotional reactivity of goats subjected to helicopter stimuli is discussed in relation to the design and testing schedule of this study. PMID:21496239

Cognitive, physical and physiological responses of school boy cricketers to a 30-over batting simulation.

Science.gov (United States)

Goble, David; Christie, Candice Jo-Anne

2017-06-01

The purpose of this study was to assess how cognitive and physical performance are affected during a prolonged, fatigue-inducing cricket-batting simulation. Fifteen amateur batters from three Eastern Cape schools in South Africa were recruited (mean ± SD: age 17 ± 0.92 years; stature 1.75 ± 0.07 m; body mass 78.3 ± 13.2 kg). Participants completed a 6-stage, 30-over batting simulation (BATEX © ). During the protocol, there were five periods of cognitive assessment (CogState brief test battery, Melbourne, Australia). The primary outcome measures from each cognitive task were speed and accuracy/error rates. Physiological (heart rate) and physical (sprint times) responses were also recorded. Sprint times deteriorated (d = 0.84; P attention and vigilance (d = 0.56; P = 0.21) and attention and working memory (d = 0.61; P = 0.11), reducing task performance after 30 overs. Therefore, prolonged batting with repeated shuttle running fatigues amateur batters and adversely affects higher-order cognitive function. This will affect decision-making, response selection, response execution and other batting-related executive processes. We recommend that training should incorporate greater proportions of centre-wicket batting with repeated, high-intensity shuttle running. This will improve batting-related skills and information processing when fatigued, making practice more representative of competition.

Physiological Indicators of Workload in a Remotely Piloted Aircraft Simulation

Science.gov (United States)

2015-10-01

cognitive workload. That is, both cognitive underload and overload can negatively impact performance (Young & Stanton, 2002). One solution to...Report contains color. 14. ABSTRACT Toward preventing performance decrements associated with mental overload in remotely piloted aircraft (RPA...operations, the current research investigated the feasibility of using physiological measures to assess cognitive workload. Two RPA operators were

Accurate initial conditions in mixed Dark Matter--Baryon simulations

CERN Document Server

Valkenburg, Wessel

2017-06-01

We quantify the error in the results of mixed baryon--dark-matter hydrodynamic simulations, stemming from outdated approximations for the generation of initial conditions. The error at redshift 0 in contemporary large simulations, is of the order of few to ten percent in the power spectra of baryons and dark matter, and their combined total-matter power spectrum. After describing how to properly assign initial displacements and peculiar velocities to multiple species, we review several approximations: (1) {using the total-matter power spectrum to compute displacements and peculiar velocities of both fluids}, (2) scaling the linear redshift-zero power spectrum back to the initial power spectrum using the Newtonian growth factor ignoring homogeneous radiation, (3) using longitudinal-gauge velocities with synchronous-gauge densities, and (4) ignoring the phase-difference in the Fourier modes for the offset baryon grid, relative to the dark-matter grid. Three of these approximations do not take into account that ...

Space Physiology within an Exercise Physiology Curriculum

Science.gov (United States)

Carter, Jason R.; West, John B.

2013-01-01

Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

Simulation Evaluation of Controller-Managed Spacing Tools under Realistic Operational Conditions

Science.gov (United States)

Callantine, Todd J.; Hunt, Sarah M.; Prevot, Thomas

2014-01-01

Controller-Managed Spacing (CMS) tools have been developed to aid air traffic controllers in managing high volumes of arriving aircraft according to a schedule while enabling them to fly efficient descent profiles. The CMS tools are undergoing refinement in preparation for field demonstration as part of NASA's Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1). System-level ATD-1 simulations have been conducted to quantify expected efficiency and capacity gains under realistic operational conditions. This paper presents simulation results with a focus on CMS-tool human factors. The results suggest experienced controllers new to the tools find them acceptable and can use them effectively in ATD-1 operations.

Lymphocytes Mitochondrial Physiology as Biomarker of Energy Metabolism during Fasted and Fed Conditions

Directory of Open Access Journals (Sweden)

Erika Cortez

2012-01-01

Full Text Available Mitochondria are central coordinators of energy metabolism, and changes of their physiology have long been associated with metabolic disorders. Thus, observations of energy dynamics in different cell types are of utmost importance. Therefore, tools with quick and easy handling are needed for consistent evaluations of such interventions. In this paper, our main hypothesis is that during different nutritional situations lymphocytes mitochondrial physiology could be associated with the metabolism of other cell types, such as cardiomyocytes, and consequently be used as metabolic biomarker. Blood lymphocytes and heart muscle fibers were obtained from both fed and 24 h-fasted mice, and mitochondrial analysis was assessed by high-resolution respirometry and western blotting. Carbohydrate-linked oxidation and fatty acid oxidation were significantly higher after fasting. Carnitine palmitoil transferase 1 and uncouple protein 2 contents were increased in the fasted group, while the glucose transporters 1 and 4 and the ratio phosphorylated AMP-activated protein kinase/AMPK did not change between groups. In summary, under a nutritional status modification, mitochondria demonstrated earlier adaptive capacity than other metabolic sensors such as glucose transporters and AMPK, suggesting the accuracy of mitochondria physiology of lymphocytes as biomarker for metabolic changes.

Physical robustness of canopy temperature models for crop heat stress simulation across environments and production conditions

DEFF Research Database (Denmark)

Webber, Heidi; White, Jeffrey W; Kimball, Bruce

2018-01-01

to simulate Tc. Model performance in predicting Tc was evaluated for two experiments in continental North America with various water, nitrogen and CO2 treatments. An empirical model fit to one dataset had the best performance, followed by the EBSC models. Stability conditions explained much of the differences...... between modeling approaches. More accurate simulation of heat stress will likely require use of energy balance approaches that consider atmospheric stability conditions....

Long-term durability experiments with concrete-based waste packages in simulated repository conditions

International Nuclear Information System (INIS)

Ipatti, A.

1993-03-01

Two extensive experiments on long-term durability of waste packages in simulated repository conditions are described. The first one is a 'half-scale experiment' comprising radioactive waste product and half-scale concrete containers in site specific groundwater conditions. The second one is 'full-scale experiment' including simulated inactive waste product and full-scale concrete container stored in slowly flowing fresh water. The scope of the experiments is to demonstrate long-term behaviour of the designed waste packages in contact with moderately concrete aggressive groundwater, and to evaluate the possible interactions between the waste product, concrete container and ground water. As the waste packages are made of high-quality concrete, provisions have been made to continue the experiments for several years

Research Article: Effects of long-term simulated Martian conditions on a freeze-dried and homogenized bacterial permafrost community

DEFF Research Database (Denmark)

Hansen, Aviaja Anna; Jensen, Lars Liengård; Kristoffersen, Tommy

2009-01-01

Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation......, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead......, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core...

A conditional stochastic weather generator for seasonal to multi-decadal simulations

Science.gov (United States)

Verdin, Andrew; Rajagopalan, Balaji; Kleiber, William; Podestá, Guillermo; Bert, Federico

2018-01-01

We present the application of a parametric stochastic weather generator within a nonstationary context, enabling simulations of weather sequences conditioned on interannual and multi-decadal trends. The generalized linear model framework of the weather generator allows any number of covariates to be included, such as large-scale climate indices, local climate information, seasonal precipitation and temperature, among others. Here we focus on the Salado A basin of the Argentine Pampas as a case study, but the methodology is portable to any region. We include domain-averaged (e.g., areal) seasonal total precipitation and mean maximum and minimum temperatures as covariates for conditional simulation. Areal covariates are motivated by a principal component analysis that indicates the seasonal spatial average is the dominant mode of variability across the domain. We find this modification to be effective in capturing the nonstationarity prevalent in interseasonal precipitation and temperature data. We further illustrate the ability of this weather generator to act as a spatiotemporal downscaler of seasonal forecasts and multidecadal projections, both of which are generally of coarse resolution.

Simulation of concrete deterioration in Finnish rock cavern conditions for final disposal of nuclear waste

International Nuclear Information System (INIS)

Kari, O.P.; Puttonen, J.

2014-01-01

Highlights: • Concrete deterioration in Finnish rock cavern disposal conditions was simulated. • Simulation requires advanced models instead of traditional linear diffusion models. • Concrete analysed performed moderately during the period of 500 years. • Corrosion of steel reinforcement cannot be excluded during the period analysed. - Abstract: A simulation of concrete ageing in Finnish rock cavern disposal conditions showed that the concrete undergoes complex deterioration processes during the period required for lowering the level of radiation. In respect of the concrete ageing, the life time of the disposal facilities shall be divided into the periods before and after the closing of the caverns. Generally, the sulphate-resistant type of concrete analysed performed moderately during the analysed period of 500 years contrary to the corrosion of steel reinforcement, which cannot be excluded. Simulation of ageing clearly requires thermodynamical methods instead of linear diffusion models based on Fick’s law, which are traditionally used in construction industry. The study proves that the thermodynamical simulation method developed with adequate experimental data also makes it possible to observe latent factors of concrete deterioration

High resolution NMR spectroscopy of physiological fluids: from metabolism to physiology

International Nuclear Information System (INIS)

Vion-Dury, J.; Nicoli, F.; Torri, G.; Torri, J.; Kriat, M.; Sciaky, M.; Davin, A.; Viout, P.; Confort-Gouny, S.; Cozzone, P.J.

1992-01-01

High resolution NMR spectroscopy of physiological fluids provides quantitative, qualitative and dynamic information on the metabolic status of the interstitial and plasma compartments under a variety of pathophysiological conditions. The simultaneous detection and quantitation by NMR spectroscopy of numerous compounds of the intermediary metabolism offers a new insight in the understanding of the 'milieu interieur'.NMR spectroscopy of physiological fluids offers a unique way to define and monitor the global metabolic homeostasis in humans. The development of this analytical approach is still limited by the scarcity of pluridisciplinary teams able to fully exploit the wealth of information present on the NMR spectrum of a fluid. While application in pharmacology and toxicology is already established, the main areas of current development are cancer, hereditary metabolic disorders, organ transplantation and neurological diseases

Growth and physiological responses to water and nutrient stress in ...

African Journals Online (AJOL)

Growth and physiological responses to water and nutrient stress in oil palm. ... changes in growth, physiology and nutrient concentration in response to two watering regimes (well-watered and water-stress conditions) and ... from 32 Countries:.

Development of a comprehensive database of scattering environmental conditions and simulation constraints for offshore wind turbines

Directory of Open Access Journals (Sweden)

C. Hübler

2017-10-01

Full Text Available For the design and optimisation of offshore wind turbines, the knowledge of realistic environmental conditions and utilisation of well-founded simulation constraints is very important, as both influence the structural behaviour and power output in numerical simulations. However, real high-quality data, especially for research purposes, are scarcely available. This is why, in this work, a comprehensive database of 13 environmental conditions at wind turbine locations in the North and Baltic Sea is derived using data of the FINO research platforms. For simulation constraints, like the simulation length and the time of initial simulation transients, well-founded recommendations in the literature are also rare. Nevertheless, it is known that the choice of simulation lengths and times of initial transients fundamentally affects the quality and computing time of simulations. For this reason, studies of convergence for both parameters are conducted to determine adequate values depending on the type of substructure, the wind speed, and the considered loading (fatigue or ultimate. As the main purpose of both the database and the simulation constraints is to compromise realistic data for probabilistic design approaches and to serve as a guidance for further studies in order to enable more realistic and accurate simulations, all results are freely available and easy to apply.

Durability of cemented waste in repository and under simulated conditions

International Nuclear Information System (INIS)

Dragolici, F.; Nicu, M.; Lungu, L.; Turcanu, C.; Rotarescu, Gh.

2000-01-01

The Romanian Radioactive Waste National Repository for low level and intermediate level radioactive waste was built in Baita - Bihor county, in an extinct uranium exploitation. The site is at 840 m above sea level and the host rock is crystalline with a low porosity, a good chemical homogeneity and impermeability, keeping these qualities over a considerable horizontal and vertical spans. To obtain the experimental data necessary for the waste form and package characterization together with the back-filling material behaviour in the repository environment, a medium term research programme (1996 - 2010) was implemented. The purpose of this experimental programme is to obtain a part of the data base necessary for the approach of medium and long term assessment of the safety and performance of Baita - Bihor Repository. The programme will provide: a deeper knowledge of the chemical species and reaction mechanisms, the structure, properties and performances of the final products. For safety reasons the behaviour of waste package, which is a main barrier, must be properly known in terms of long term durability in real repository conditions. Characterization of the behaviour includes many interactions between the waste package itself and the surrounding near field conditions such as mineralogy, hydrogeology and groundwater chemistry. To obtain a more deeper knowledge of the species and physical-chemical reactions participating in the matrix formation, as well as their future behaviour during the disposal period, a thorough XRD study started in 1998. For Romanian Radioactive Waste National Repository (DNDR) Baita - Bihor the following steps are planned for the conditioned waste matrix characterization in simulated and real conditions: - preparation and characterization of normal reference matrices based on different cement formulations; - preparation of reference simulated sludge cemented matrices containing iron hydroxide and iron phosphate; - selection of real and

Rate Theory Modeling and Simulation of Silicide Fuel at LWR Conditions

Energy Technology Data Exchange (ETDEWEB)

Miao, Yinbin [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Ye, Bei [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Hofman, Gerard [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Yacout, Abdellatif [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Gamble, Kyle [Idaho National Lab. (INL), Idaho Falls, ID (United States). Fuel Modeling and Simulation; Mei, Zhi-Gang [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

2016-08-29

As a promising candidate for the accident tolerant fuel (ATF) used in light water reactors (LWRs), the fuel performance of uranium silicide (U₃Si₂) at LWR conditions needs to be well understood. In this report, rate theory model was developed based on existing experimental data and density functional theory (DFT) calculations so as to predict the fission gas behavior in U₃Si₂ at LWR conditions. The fission gas behavior of U₃Si₂ can be divided into three temperature regimes. During steady-state operation, the majority of the fission gas stays in intragranular bubbles, whereas the dominance of intergranular bubbles and fission gas release only occurs beyond 1000 K. The steady-state rate theory model was also used as reference to establish a gaseous swelling correlation of U₃Si₂ for the BISON code. Meanwhile, the overpressurized bubble model was also developed so that the fission gas behavior at LOCA can be simulated. LOCA simulation showed that intragranular bubbles are still dominant after a 70 second LOCA, resulting in a controllable gaseous swelling. The fission gas behavior of U₃Si₂ at LWR conditions is benign according to the rate theory prediction at both steady-state and LOCA conditions, which provides important references to the qualification of U₃Si₂ as a LWR fuel material with excellent fuel performance and enhanced accident tolerance.

Simulation of KAEVER experiments on aerosol behavior in a nuclear power plant containment at accident conditions with the ASTEC code

International Nuclear Information System (INIS)

Kljenak, I.; Mavko, B.

2006-01-01

Experiments on aerosol behaviour in saturated and non-saturated atmosphere, which were performed in the KAEVER experimental facility, were simulated with the severe accident computer code ASTEC CPA V1.2. The specific purpose of the work was to assess the capability of the code to model aerosol condensation and deposition in the containment of a light-water-reactor nuclear power plant at severe accident conditions, if the atmosphere saturation conditions are simulated adequately. Five different tests were first simulated with boundary conditions, obtained from the experiments. In all five tests, a non-saturated atmosphere was simulated, although, in four tests, the atmosphere was allegedly saturated. The simulations were repeated with modified boundary conditions, to obtain a saturated atmosphere in all tests. Results of dry and wet aerosol concentrations in the test vessel atmosphere for both sets of simulations are compared to experimental results. (author)

The Physiology of Adventitious Roots1

Science.gov (United States)

Steffens, Bianka; Rasmussen, Amanda

2016-01-01

Adventitious roots are plant roots that form from any nonroot tissue and are produced both during normal development (crown roots on cereals and nodal roots on strawberry [Fragaria spp.]) and in response to stress conditions, such as flooding, nutrient deprivation, and wounding. They are important economically (for cuttings and food production), ecologically (environmental stress response), and for human existence (food production). To improve sustainable food production under environmentally extreme conditions, it is important to understand the adventitious root development of crops both in normal and stressed conditions. Therefore, understanding the regulation and physiology of adventitious root formation is critical for breeding programs. Recent work shows that different adventitious root types are regulated differently, and here, we propose clear definitions of these classes. We use three case studies to summarize the physiology of adventitious root development in response to flooding (case study 1), nutrient deficiency (case study 2), and wounding (case study 3). PMID:26697895

Physiologic changes associated with violence and abuse exposure: an examination of related medical conditions.

Science.gov (United States)

Keeshin, Brooks R; Cronholm, Peter F; Strawn, Jeffrey R

2012-01-01

Although the extant evidence is replete with data supporting linkages between exposure to violence or abuse and the subsequent development of medical illnesses, the underlying mechanisms of these relationships are poorly defined and understood. Physiologic changes occurring in violence- or abuse-exposed individuals point to potentially common biological pathways connecting traumatic exposures with medical outcomes. Herein, the evidence describing the long-term physiologic changes in abuse- and violence-exposed populations and associated medical illnesses are reviewed. Current data support that (a) specific neurobiochemical changes are associated with exposure to violence and abuse; (b) several biological pathways have the potential to lead to the development of future illness; and (c) common physiologic mechanisms may moderate the severity, phenomenology, or clinical course of medical illnesses in individuals with histories of exposure to violence or abuse. Importantly, additional work is needed to advance our emerging understanding of the biological mechanisms connecting exposure to violence and abuse and negative health outcomes.

PHYSIOLOGY OF ACID BASE BALANCE

Directory of Open Access Journals (Sweden)

Awati

2014-12-01

Full Text Available Acid-base, electrolyte, and metabolic disturbances are common in the intensive care unit. Almost all critically ill patients often suffer from compound acid-base and electrolyte disorders. Successful evaluation and management of such patients requires recognition of common patterns (e.g., metabolic acidosis and the ability to dissect one disorder from another. The intensivists needs to identify and correct these condition with the easiest available tools as they are the associated with multiorgan failure. Understanding the elements of normal physiology in these areas is very important so as to diagnose the pathological condition and take adequate measures as early as possible. Arterial blood gas analysis is one such tool for early detection of acid base disorder. Physiology of acid base is complex and here is the attempt to simplify it in our day to day application for the benefit of critically ill patients.

Physiological responses at short distances from a parametric speaker

Directory of Open Access Journals (Sweden)

Lee Soomin

2012-06-01

Full Text Available Abstract In recent years, parametric speakers have been used in various circumstances. In our previous studies, we verified that the physiological burden of the sound of parametric speaker set at 2.6 m from the subjects was lower than that of the general speaker. However, nothing has yet been demonstrated about the effects of the sound of a parametric speaker at the shorter distance between parametric speakers the human body. Therefore, we studied this effect on physiological functions and task performance. Nine male subjects participated in this study. They completed three consecutive sessions: a 20-minute quiet period as a baseline, a 30-minute mental task period with general speakers or parametric speakers, and a 20-minute recovery period. We measured electrocardiogram (ECG photoplethysmogram (PTG, electroencephalogram (EEG, systolic and diastolic blood pressure. Four experiments, one with a speaker condition (general speaker and parametric speaker, the other with a distance condition (0.3 m and 1.0 m, were conducted respectively at the same time of day on separate days. To examine the effects of the speaker and distance, three-way repeated measures ANOVA (speaker factor x distance factor x time factor were conducted. In conclusion, we found that the physiological responses were not significantly different between the speaker condition and the distance condition. Meanwhile, it was shown that the physiological burdens increased with progress in time independently of speaker condition and distance condition. In summary, the effects of the parametric speaker at the 2.6 m distance were not obtained at the distance of 1 m or less.

Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product.

Science.gov (United States)

Crum, Alia J; Phillips, Damon J; Goyer, J Parker; Akinola, Modupe; Higgins, E Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, "AquaCharge Energy Water," falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water.

Influence of physiological sources on the impedance cardiogram analyzed using 4D FEM simulations

International Nuclear Information System (INIS)

Ulbrich, Mark; Leonhardt, Steffen; Walter, Marian; Mühlsteff, Jens

2014-01-01

Impedance cardiography is a simple and inexpensive method to acquire data on hemodynamic parameters. This study analyzes the influence of four dynamic physiological sources (aortic expansion, heart contraction, lung perfusion and erythrocyte orientation) on the impedance signal using a model of the human thorax with a high temporal resolution (125 Hz) based on human MRI data. Simulations of electromagnetic fields were conducted using the finite element method. The ICG signal caused by these sources shows very good agreement with the measured signals (r = 0.89). Standard algorithms can be used to extract characteristic points to calculate left ventricular ejection time and stroke volume (SV). In the presented model, the calculated SV equals the implemented left ventricular volume change of the heart. It is shown that impedance changes due to lung perfusion and heart contraction compensate themselves, and that erythrocyte orientation together with the aortic impedance basically form the ICG signal while taking its characteristic morphology from the aortic signal. The model is robust to conductivity changes of tissues and organ displacements. In addition, it reflects the multi-frequency behavior of the thoracic impedance. (paper)

Measurement of palmitoylethanolamide and other N-acylethanolamines during physiological and pathological conditions

NARCIS (Netherlands)

Balvers, M.G.J.; Verhoeckx, K.C.M.; Meijerink, J.; Wortelboer, H.M.; Witkamp, R.F.

2013-01-01

Palmitoylethanolamide (PEA) belongs to the N-acyl ethanolamines (NAEs), a group of endogenous compounds involved in a variety of physiological processes, including energy homeostasis and inflammation. This review focuses on the analysis of PEA in plasma and tissues and discusses effects of diet and

Cavitation Simulation on Conventional and Highly-Skewed Propellers in the Behind Condition

DEFF Research Database (Denmark)

Shin, Keun Woo; Andersen, Poul; Mikkelsen, Robert Flemming

2011-01-01

The cavitating flows around conventional and highly-skewed propellers in the behind-hull condition are simulated by an in-house RANS solver, EllipSys (Sørensen 2003), with the cavitation model, based on the homogeneous equilibrium modeling (HEM) approach and a vapor transport equation. The valida...

Studies on the survival of Ascaris suum eggs under laboratory and simulated field conditions

NARCIS (Netherlands)

Gaasenbeek, C.P.H.; Borgsteede, F.H.M.

1998-01-01

A series of four experiments was carried out to study the survival of Ascaris suum eggs: in a pig slurry unit on a farm, in the laboratory under anaerobic conditions and different relative humidities (rH), and under simulated field conditions. Survival of eggs in the pig slurry unit was 20% after

Isobaric-isothermal Monte Carlo simulations from first principles: Application to liquid water at ambient conditions

Energy Technology Data Exchange (ETDEWEB)

McGrath, M; Siepmann, J I; Kuo, I W; Mundy, C J; VandeVondele, J; Hutter, J; Mohamed, F; Krack, M

2004-12-02

A series of first principles Monte Carlo simulations in the isobaric-isothermal ensemble were carried out for liquid water at ambient conditions (T = 298 K and p = 1 atm). The Becke-Lee-Yang-Parr (BLYP) exchange and correlation energy functionals and norm-conserving Goedecker-Teter-Hutter (GTH) pseudopotentials were employed with the CP2K simulation package to examine systems consisting of 64 water molecules. The fluctuations in the system volume encountered in simulations in the isobaric-isothermal ensemble requires a reconsideration of the suitability of the typical charge density cutoff and the regular grid generation method previously used for the computation of the electrostatic energy in first principles simulations in the microcanonical or canonical ensembles. In particular, it is noted that a much higher cutoff is needed and that the most computationally efficient method of creating grids can result in poor simulations. Analysis of the simulation trajectories using a very large charge density cutoff at 1200 Ry and four different grid generation methods point to a substantially underestimated liquid density of about 0.85 g/cm{sup 3} resulting in a somewhat understructured liquid (with a value of about 2.7 for the height of the first peak in the oxygen/oxygen radial distribution function) for BLYP-GTH water at ambient conditions.

Influence of changes in initial conditions for the simulation of dynamic systems

Energy Technology Data Exchange (ETDEWEB)

Kotyrba, Martin [Department of Informatics and Computers, University of Ostrava, 30 dubna 22, Ostrava (Czech Republic)

2015-03-10

Chaos theory is a field of study in mathematics, with applications in several disciplines including meteorology, sociology, physics, engineering, economics, biology, and philosophy. Chaos theory studies the behavior of dynamical systems that are highly sensitive to initial conditions—a paradigm popularly referred to as the butterfly effect. Small differences in initial conditions field widely diverging outcomes for such dynamical systems, rendering long-term prediction impossible in general. This happens even though these systems are deterministic, meaning that their future behavior is fully determined by their initial conditions, with no random elements involved. In this paperinfluence of changes in initial conditions will be presented for the simulation of Lorenz system.

Avian reproductive physiology

Science.gov (United States)

Gee, G.F.; Gibbons, Edward F.; Durrant, Barbara S.; Demarest, Jack

1995-01-01

Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos

Surrogate fuel assembly multi-axis shaker tests to simulate normal conditions of rail and truck transport

Energy Technology Data Exchange (ETDEWEB)

McConnell, Paul E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Koenig, Greg John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Uncapher, William Leonard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grey, Carissa [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Engelhardt, Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Saltzstein, Sylvia J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorenson, Ken B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-05-01

This report describes the third set of tests (the “DCLa shaker tests”) of an instrumented surrogate PWR fuel assembly. The purpose of this set of tests was to measure strains and accelerations on Zircaloy-4 fuel rods when the PWR assembly was subjected to rail and truck loadings simulating normal conditions of transport when affixed to a multi-axis shaker. This is the first set of tests of the assembly simulating rail normal conditions of transport.

Simulated conditions of microgravity suppress progesterone production by luteal cells of the pregnant rat

Science.gov (United States)

Bhat, G. K.; Yang, H.; Sridaran, R.

2001-01-01

The purpose of this study was to assess whether simulated conditions of microgravity induce changes in the production of progesterone by luteal cells of the pregnant rat ovary using an in vitro model system. The microgravity environment was simulated using either a high aspect ratio vessel (HARV) bioreactor with free fall or a clinostat without free fall of cells. A mixed population of luteal cells isolated from the corpora lutea of day 8 pregnant rats was attached to cytodex microcarrier beads (cytodex 3). These anchorage dependent cells were placed in equal numbers in the HARV or a spinner flask control vessel in culture conditions. It was found that HARV significantly reduced the daily production of progesterone from day 1 through day 8 compared to controls. Scanning electron microscopy showed that cells attached to the microcarrier beads throughout the duration of the experiment in both types of culture vessels. Cells cultured in chamber slide flasks and placed in a clinostat yielded similar results when compared to those in the HARV. Also, when they were stained by Oil Red-O for lipid droplets, the clinostat flasks showed a larger number of stained cells compared to control flasks at 48 h. Further, the relative amount of Oil Red-O staining per milligram of protein was found to be higher in the clinostat than in the control cells at 48 h. It is speculated that the increase in the level of lipid content in cells subjected to simulated conditions of microgravity may be due to a disruption in cholesterol transport and/or lesions in the steroidogenic pathway leading to a fall in the synthesis of progesterone. Additionally, the fall in progesterone in simulated conditions of microgravity could be due to apoptosis of luteal cells.

Mental Simulation of Painful Situations Has an Impact on Posture and Psychophysiological Parameters

Directory of Open Access Journals (Sweden)

Thierry Lelard

2017-11-01

Full Text Available Embodiment is made possible by the ability to imagine ourselves in a particular situation (mental simulation. Postural changes have been demonstrated in response to painful situations, but the effect of an implicit instruction has not been studied. The present study was designed to record differential responses according to whether or not subjects were instructed to imagine themselves in a painful or non-painful situation. Painful stimuli and instructions to mentally simulate the displayed situation were hypothesized to induce postural changes that could be demonstrated by changes in the center of pressure (COP trajectory compared to viewing the same stimuli with no instructions. We hypothesized that mental simulation of a painful situation would induce embodiment of the emotional situation as reflected by posterior displacement of the COP and physiological responses as compared to passive observation of the same visual scene. Thirty-one subjects participated in this study while standing quietly on a posturographic platform with presentation of visual stimuli depicting scenes defining three experimental conditions (painful, non-painful and neutral situations for 12 s. Physiological measurements [heart rate (HR and electrodermal activity] and postural responses (COP displacements were recorded in response to the stimuli with or without instructions to imagine themselves in the situation. Time-course analyses (1 s sliding window were conducted for several postural parameters, HR and electrodermal response. An interaction effect (instruction × stimuli × time demonstrated that mental simulation induced posterior displacement of the mean position of the COP at different times during presentation of visual stimuli (4 s; 9–12 s. An effect of instruction was reported for HR (HR was higher in the mental simulation condition, while a stimulation effect was reported only for HR (lower for painful stimuli than for non-painful stimuli. The results of

Modelling and simulation of concrete leaching under outdoor exposure conditions

International Nuclear Information System (INIS)

Schiopu, Nicoleta; Tiruta-Barna, Ligia; Jayr, Emmanuel; Mehu, Jacques; Moszkowicz, Pierre

2009-01-01

Recently, a demand regarding the assessment of release of dangerous substances from construction products was raised by European Commission which has issued the Mandate M/366 addressed to CEN. This action is in relation with the Essential Requirement No. 3 'Hygiene, Health and Environment' of the Construction Products Directive (89/106/EC). The potential hazard for environment and health may arise in different life cycle stages of a construction product. During the service life stage, the release of substances due to contact with the rain water is the main potential hazard source, as a consequence of the leaching phenomenon. The objective of this paper is to present the development of a coupled chemical-transport model for the case of a concrete based construction product, i.e. concrete paving slabs, exposed to rain water under outdoor exposure conditions. The development of the model is based on an iterative process of comparing the experimental results with the simulated results up to an acceptable fit. The experiments were conducted at laboratory scale (equilibrium and dynamic leaching tests) and field scale. The product was exposed for one year in two types of leaching scenarios under outdoor conditions, 'runoff' and 'stagnation', and the element release was monitored. The model was calibrated using the experimental data obtained at laboratory scale and validated against measured field data, by taking into account the specific rain water balance and the atmospheric CO 2 uptake as input parameters. The numerical tool used in order to model and simulate the leaching behaviour was PHREEQC, coupled with the Lawrence Livermore National Laboratory (LLNL) thermodynamic data base. The simulation results are satisfying and the paper demonstrates the feasibility of the modelling approach for the leaching behaviour assessment of concrete type construction materials

Identification of intestinal loss of a drug through physiologically based pharmacokinetic simulation of plasma concentration-time profiles.

Science.gov (United States)

Peters, Sheila Annie

2008-01-01

Despite recent advances in understanding of the role of the gut as a metabolizing organ, recognition of gut wall metabolism and/or other factors contributing to intestinal loss of a compound has been a challenging task due to the lack of well characterized methods to distinguish it from first-pass hepatic extraction. The implications of identifying intestinal loss of a compound in drug discovery and development can be enormous. Physiologically based pharmacokinetic (PBPK) simulations of pharmacokinetic profiles provide a simple, reliable and cost-effective way to understand the mechanisms underlying pharmacokinetic processes. The purpose of this article is to demonstrate the application of PBPK simulations in bringing to light intestinal loss of orally administered drugs, using two example compounds: verapamil and an in-house compound that is no longer in development (referred to as compound A in this article). A generic PBPK model, built in-house using MATLAB software and incorporating absorption, metabolism, distribution, biliary and renal elimination models, was employed for simulation of concentration-time profiles. Modulation of intrinsic hepatic clearance and tissue distribution parameters in the generic PBPK model was done to achieve a good fit to the observed intravenous pharmacokinetic profiles of the compounds studied. These optimized clearance and distribution parameters are expected to be invariant across different routes of administration, as long as the kinetics are linear, and were therefore employed to simulate the oral profiles of the compounds. For compounds with reasonably good solubility and permeability, an area under the concentration-time curve for the simulated oral profile that far exceeded the observed would indicate some kind of loss in the intestine. PBPK simulations applied to compound A showed substantial loss of the compound in the gastrointestinal tract in humans but not in rats. This accounted for the lower bioavailability of the

Importance of Physical and Physiological Parameters in Simulated Particle Transport in the Alveolar Zone of the Human Lung

Directory of Open Access Journals (Sweden)

Dogan Ciloglu

2017-01-01

Full Text Available The trajectory and deposition efficiency of micron-sized (1–5 µm particles, inhaled into the pulmonary system, are accurately determined with the aid of a newly developed model and modified simulation techniques. This alveolar model, which has a simple but physiologically appropriate geometry, and the utilized fluid structure interaction (FSI methods permit the precise simulation of tissue wall deformation and particle fluid interactions. The relation between tissue movement and airflow in the alveolated duct is solved by a two-way fluid structure interaction simulation technique, using ANSYS Workbench (Release 16.0, ANSYS INC., Pittsburgh, PA, USA, 2015. The dynamic transport of particles and their deposition are investigated as a function of aerodynamic particle size, tissue visco-elasticity, tidal breathing period, gravity orientation and particle–fluid interactions. It is found that the fluid flows and streamlines differ between the present flexible model and rigid models, and the two-way coupling particle trajectories vary relative to one-way particle coupling. In addition, the results indicate that modelling the two-way coupling particle system is important because the two-way discrete phase method (DPM approach despite its complexity provides more extensive particle interactions and is more reliable than transport results from the one-way DPM approach. The substantial difference between the results of the two approaches is likely due to particle–fluid interactions, which re-suspend the sediment particles in the airway stream and hence pass from the current generation.

Simulation of snow distribution and melt under cloudy conditions in an Alpine watershed

Directory of Open Access Journals (Sweden)

H.-Y. Li

2011-07-01

Full Text Available An energy balance method and remote-sensing data were used to simulate snow distribution and melt in an alpine watershed in northwestern China within a complete snow accumulation-melt period. The spatial energy budgets were simulated using meteorological observations and a digital elevation model of the watershed. A linear interpolation method was used to estimate the daily snow cover area under cloudy conditions, using Moderate Resolution Imaging Spectroradiometer (MODIS data. Hourly snow distribution and melt, snow cover extent and daily discharge were included in the simulated results. The root mean square error between the measured snow-water equivalent samplings and the simulated results is 3.2 cm. The Nash and Sutcliffe efficiency statistic (NSE between the measured and simulated discharges is 0.673, and the volume difference (Dv is 3.9 %. Using the method introduced in this article, modelling spatial snow distribution and melt runoff will become relatively convenient.

Extracellular Membrane Vesicles as Vehicles for Brain Cell-to-Cell Interactions in Physiological as well as Pathological Conditions

Directory of Open Access Journals (Sweden)

Gabriella Schiera

2015-01-01

Full Text Available Extracellular vesicles are involved in a great variety of physiological events occurring in the nervous system, such as cross talk among neurons and glial cells in synapse development and function, integrated neuronal plasticity, neuronal-glial metabolic exchanges, and synthesis and dynamic renewal of myelin. Many of these EV-mediated processes depend on the exchange of proteins, mRNAs, and noncoding RNAs, including miRNAs, which occurs among glial and neuronal cells. In addition, production and exchange of EVs can be modified under pathological conditions, such as brain cancer and neurodegeneration. Like other cancer cells, brain tumours can use EVs to secrete factors, which allow escaping from immune surveillance, and to transfer molecules into the surrounding cells, thus transforming their phenotype. Moreover, EVs can function as a way to discard material dangerous to cancer cells, such as differentiation-inducing proteins, and even drugs. Intriguingly, EVs seem to be also involved in spreading through the brain of aggregated proteins, such as prions and aggregated tau protein. Finally, EVs can carry useful biomarkers for the early diagnosis of diseases. Herein we summarize possible roles of EVs in brain physiological functions and discuss their involvement in the horizontal spreading, from cell to cell, of both cancer and neurodegenerative pathologies.

CME Simulations with Boundary Conditions Derived from Multiple Viewpoints of STEREO

Science.gov (United States)

Singh, T.; Yalim, M. S.; Pogorelov, N. V.

2017-12-01

Coronal Mass Ejections (CMEs) are major drivers of extreme space weather conditions, which is a matter of huge concern for our modern technologically dependent society. Development of numerical approaches that would reproduce CME propagation through the interplanetary space is an important step towards our capability to predict CME arrival time at Earth and their geo-effectiveness. It is also important that CMEs are propagating through a realistic, data-driven background solar wind (SW). In this study, we use a version of the flux-rope-driven Gibson-Low (GL) model to simulate CMEs. We derive inner boundary conditions for the GL flux rope model using the Graduate Cylindrical Shell (GCS) method. This method uses viewpoints from STEREO A and B, and SOHO/LASCO coronagraphs to determine the size and orientation of a CME flux rope as it starts to erupt from Sun. A flux rope created this way is inserted into an SDO/HMI vector magnetogram driven SW background obtained with the Multi-Scale Fluid-Kinetic Simulation Suite (MS-FLUKSS). Numerical results are compared with STEREO, SDO/AIA and SOHO/LASCO observations in particular in terms of the CME speed, acceleration and magnetic field structure.

Aspect of ECMWF downscaled Regional Climate Modeling in simulating Indian summer monsoon rainfall and dependencies on lateral boundary conditions

Science.gov (United States)

Ghosh, Soumik; Bhatla, R.; Mall, R. K.; Srivastava, Prashant K.; Sahai, A. K.

2018-03-01

Climate model faces considerable difficulties in simulating the rainfall characteristics of southwest summer monsoon. In this study, the dynamical downscaling of European Centre for Medium-Range Weather Forecast's (ECMWF's) ERA-Interim (EIN15) has been utilized for the simulation of Indian summer monsoon (ISM) through the Regional Climate Model version 4.3 (RegCM-4.3) over the South Asia Co-Ordinated Regional Climate Downscaling EXperiment (CORDEX) domain. The complexities of model simulation over a particular terrain are generally influenced by factors such as complex topography, coastal boundary, and lack of unbiased initial and lateral boundary conditions. In order to overcome some of these limitations, the RegCM-4.3 is employed for simulating the rainfall characteristics over the complex topographical conditions. For reliable rainfall simulation, implementations of numerous lower boundary conditions are forced in the RegCM-4.3 with specific horizontal grid resolution of 50 km over South Asia CORDEX domain. The analysis is considered for 30 years of climatological simulation of rainfall, outgoing longwave radiation (OLR), mean sea level pressure (MSLP), and wind with different vertical levels over the specified region. The dependency of model simulation with the forcing of EIN15 initial and lateral boundary conditions is used to understand the impact of simulated rainfall characteristics during different phases of summer monsoon. The results obtained from this study are used to evaluate the activity of initial conditions of zonal wind circulation speed, which causes an increase in the uncertainty of regional model output over the region under investigation. Further, the results showed that the EIN15 zonal wind circulation lacks sufficient speed over the specified region in a particular time, which was carried forward by the RegCM output and leads to a disrupted regional simulation in the climate model.

Physiological and Biochemical Responses of Saltmarsh Plant Spartina alterniflora to Long-term Wave Exposure

Science.gov (United States)

Zhou, W.

2017-12-01

In recent years, ecosystem-based flood defence, i.e., eco-shoreline or living shoreline, that is more sustainable and cost-effective than conventional coastal engineering structures has been brought into large-scale practice. Numerous laboratory experiments have been performed to explore the wave-attenuation effects of saltmarsh plants that are widely used in eco-shoreline, and yet no study has ever been conducted on the physiological and biochemical responses of saltmarsh plants to long-term wave exposure, presumably due to the constraint that traditional wave generator fails to provide long-term stable wave conditions necessary for physiological experiments. In this study, a long-term shallow water wave environment simulator using crank-yoke mechanism was built in the laboratory to address this gap. Experiments using the wave simulator were conducted for 8 weeks in a greenhouse and the temperature was maintained at 24-30°C. 5‰ artificial sea water was filled in the test tank, and the water was changed every week. After being acclimatized, nine S. alterniflora individual plants (initial height 30 cm) were planted in each of the three streamlined cuboid containers (12cm×12cm×20cm), which were partially submerged in a test tank, and undertook horizontal sinusoidal motion imposed by the crank-yoke mechanism to mimic plants exposed to shallow water waves. The substrate filled in the containers were soils collected from the Yellow River Delta, so were the S. alterniflora plants. A realistic stem density of 400 stems/m2 was tested, which corresponded to a grid spacing of 5.0 cm. Shallow water waves with six wave heights (H: 0.041, 0.055, 0.069, 0.033, 0.044 and 0.056m), one plants submerged depth (0.1m) and two wave periods (2s and 3s) were simulated in the experiments. A no wave condition was also tested as control. Key physiological and biochemical parameters, such as stem length, peroxidase activity, catalase, superoxide dismutase, ascorbate peroxidase, etc

Surrogate fuel assembly multi-axis shaker tests to simulate normal conditions of rail and truck transport

Energy Technology Data Exchange (ETDEWEB)

McConnell, Paul E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Koenig, Greg John [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Uncapher, William Leonard [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grey, Carissa [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Engelhardt, Charles [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Saltzstein, Sylvia J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorenson, Ken B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-05-12

This report describes the third set of tests (the “DCL^a shaker tests”) of an instrumented surrogate PWR fuel assembly. The purpose of this set of tests was to measure strains and accelerations on Zircaloy-4 fuel rods when the PWR assembly was subjected to rail and truck loadings simulating normal conditions of transport when affixed to a multi-axis shaker. This is the first set of tests of the assembly simulating rail normal conditions of transport.

Discussion on boundary conditions for simplified numerical simulation of swirl velocity in a cylinder of engine; Engine nai swirl no kan`i suchi simulation ni okeru kyokai joken no kento

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, K; Tasaka, H; Tan, H [Miyazaki University, Miyazaki (Japan)

1997-10-01

A simplified and quantitative simulation to calculate a swirl velocity in a cylinder with short time and low cost was offered by one of the authors. But the discussion on boundary conditions for the simulation was not enough. In this paper, measurements of diminution of the swirl velocity in a vessel packed with a fluid and simulations corresponding to the measurements were carried out varying aspect ratio of the vessel. From the measurement and calculating results, boundary conditions were obtained. The validity of the obtained boundary conditions was discussed and the adequate boundary conditions were determined. 4 refs., 6 figs., 2 tabs.

Highly stable and degradable multifunctional microgel for self-regulated insulin delivery under physiological conditions

Science.gov (United States)

Zhang, Xinjie; Lü, Shaoyu; Gao, Chunmei; Chen, Chen; Zhang, Xuan; Liu, Mingzhu

2013-06-01

The response to glucose, pH and temperature, high drug loading capacity, self-regulated drug delivery and degradation in vivo are simultaneously probable by applying a multifunctional microgel under a rational design in a colloid chemistry method. Such multifunctional microgels are fabricated with N-isopropylacrylamide (NIPAAm), (2-dimethylamino)ethyl methacrylate (DMAEMA) and 3-acrylamidephenylboronic acid (AAPBA) through a precipitation emulsion method and cross-linked by reductive degradable N,N'-bis(arcyloyl)cystamine (BAC). This novel kind of microgel with a narrow size distribution (~250 nm) is suitable for diabetes because it can adapt to the surrounding medium of different glucose concentrations over a clinically relevant range (0-20 mM), control the release of preloaded insulin and is highly stable under physiological conditions (pH 7.4, 0.15 M NaCl, 37 °C). When synthesized multifunctional microgels regulate drug delivery, they gradually degrade as time passes and, as a result, show enhanced biocompatibility. This exhibits a new proof-of-concept for diabetes treatment that takes advantage of the properties of each building block from a multifunctional micro-object. These highly stable and versatile multifunctional microgels have the potential to be used for self-regulated therapy and monitoring of the response to treatment, or even simultaneous diagnosis as nanobiosensors.The response to glucose, pH and temperature, high drug loading capacity, self-regulated drug delivery and degradation in vivo are simultaneously probable by applying a multifunctional microgel under a rational design in a colloid chemistry method. Such multifunctional microgels are fabricated with N-isopropylacrylamide (NIPAAm), (2-dimethylamino)ethyl methacrylate (DMAEMA) and 3-acrylamidephenylboronic acid (AAPBA) through a precipitation emulsion method and cross-linked by reductive degradable N,N'-bis(arcyloyl)cystamine (BAC). This novel kind of microgel with a narrow size

Physiology of in vitro culture

Directory of Open Access Journals (Sweden)

Maria Jesús Cañal

2001-01-01

Full Text Available The culture procedures described up to the eighties, did not made any mention to the environmental control of in vitro plant development. However, growth rate, development and many of the physiologic-morphologic features of the in vitro grown plants are influenced by the culture vessel. The increasing knowledge about the environmental control of culture vessels under sterile conditions, is helping to change micorpropagation procedures. The in vitro environment with lower rate ventilation, brings about low flow rates of matter and energy, with minimum variations of temperature, high relative humidity and large daily changes of the concentration of CO2 inside the culture vessel. The type of culture vessel (size, shape, fabric and closing system can influence the evolution of the atmosphere along the time of culture. Although submitted to different stresses factors plant can be grown in vitro, but plants can be faulty in their anatomy, morphology and physiology. As a consequence, these plants shown a phenotype unable to survive to ex vitro conditions. Different strategies can be used to control the atmosphere along the different phases of micropropagation, in heterotrophic, mixotrophic or autotrophic cultures. The election of the best strategy will be based on different factors as species, number of transplantes required, or quality-price relationship. enviromental control, tissue culture, micropropagation Keywords: in vitro enviromental, characteristic physiology,

Implantable Nanosensors: Towards Continuous Physiologic Monitoring

OpenAIRE

Ruckh, Timothy T.; Clark', Heather A.

2013-01-01

Continuous physiologic monitoring would add greatly to both home and clinical medical treatment for chronic conditions. Implantable nanosensors are a promising platform for designing continuous monitoring systems. This feature reviews design considerations and current approaches towards such devices.

3-D simulations to investigate initial condition effects on the growth of Rayleigh-Taylor mixing

Energy Technology Data Exchange (ETDEWEB)

Andrews, Malcolm J [Los Alamos National Laboratory

2008-01-01

The effect of initial conditions on the growth rate of turbulent Rayleigh-Taylor (RT) mixing has been studied using carefully formulated numerical simulations. An integrated large-eddy simulation (ILES) that uses a finite-volume technique was employed to solve the three-dimensional incompressible Euler equations with numerical dissipation. The initial conditions were chosen to test the dependence of the RT growth parameters ({alpha}{sub b}, {alpha}{sub s}) on variations in (a) the spectral bandwidth, (b) the spectral shape, and (c) discrete banded spectra. Our findings support the notion that the overall growth of the RT mixing is strongly dependent on initial conditions. Variation in spectral shapes and bandwidths are found to have a complex effect of the late time development of the RT mixing layer, and raise the question of whether we can design RT transition and turbulence based on our choice of initial conditions. In addition, our results provide a useful database for the initialization and development of closures describing RT transition and turbulence.

Effect of encapsulation of selected probiotic cell on survival in simulated gastrointestinal tract condition

Directory of Open Access Journals (Sweden)

Hasiah Ayama

2014-06-01

Full Text Available The health benefits of probiotic bacteria have been led to their increasing use in foods. Encapsulation has been investigated to improve their survival. In this study, the selection, encapsulation and viability of lactic acid bacteria (LAB with probiotic properties in simulated gastrointestinal tract (GIT condition were investigated. One hundred and fifty isolates of LAB were obtained from 30 samples of raw cow and goat milk and some fermented foods. Nine isolates could survive under GIT condition and only 3 isolates exhibited an antimicrobial activity against all food-borne pathogenic bacteria. Among them, 2 isolates (CM21 and CM53 exhibited bile salt hydrolase activity on glycocholate and glycodeoxycholate agar plates and were identified as Lactobacillus plantarum. CM53 was selected for encapsulation using 1-3% alginate and 2% Hi-maize resistant starch by emulsion system. Viability and releasing ability of encapsulated CM53 in simulated GIT condition was increased in accordance to the alginate concentration and incubation time, respectively.

Interactive Dynamic-System Simulation

CERN Document Server

Korn, Granino A

2010-01-01

Showing you how to use personal computers for modeling and simulation, Interactive Dynamic-System Simulation, Second Edition provides a practical tutorial on interactive dynamic-system modeling and simulation. It discusses how to effectively simulate dynamical systems, such as aerospace vehicles, power plants, chemical processes, control systems, and physiological systems. Written by a pioneer in simulation, the book introduces dynamic-system models and explains how software for solving differential equations works. After demonstrating real simulation programs with simple examples, the author

Sublethal effects of catch-and-release fishing: measuring capture stress, fish impairment, and predation risk using a condition index

Science.gov (United States)

Campbell, Matthew D.; Patino, Reynaldo; Tolan, J.M.; Strauss, R.E.; Diamond, S.

2009-01-01

The sublethal effects of simulated capture of red snapper (Lutjanus campechanus) were analysed using physiological responses, condition indexing, and performance variables. Simulated catch-and-release fishing included combinations of depth of capture and thermocline exposure reflective of environmental conditions experienced in the Gulf of Mexico. Frequency of occurrence of barotrauma and lack of reflex response exhibited considerable individual variation. When combined into a single condition or impairment index, individual variation was reduced, and impairment showed significant increases as depth increased and with the addition of thermocline exposure. Performance variables, such as burst swimming speed (BSS) and simulated predator approach distance (AD), were also significantly different by depth. BSSs and predator ADs decreased with increasing depth, were lowest immediately after release, and were affected for up to 15 min, with longer recovery times required as depth increased. The impairment score developed was positively correlated with cortisol concentration and negatively correlated with both BSS and simulated predator AD. The impairment index proved to be an efficient method to estimate the overall impairment of red snapper in the laboratory simulations of capture and shows promise for use in field conditions, to estimate release mortality and vulnerability to predation.

RANS simulation of cavitation and hull pressure fluctuation for marine propeller operating behind-hull condition

Science.gov (United States)

Paik, Kwang-Jun; Park, Hyung-Gil; Seo, Jongsoo

2013-12-01

Simulations of cavitation flow and hull pressure fluctuation for a marine propeller operating behind a hull using the unsteady Reynolds-Averaged Navier-Stokes equations (RANS) are presented. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. Simulations are performed in design and ballast draught conditions to study the effect of cavitation number. And two propellers with slightly different geometry are simulated to validate the detectability of the numerical simulation. All simulations are performed using a commercial CFD software FLUENT. Cavitation patterns of the simulations show good agreement with the experimental results carried out in Samsung CAvitation Tunnel (SCAT). The simulation results for the hull pressure fluctuation induced by a propeller are also compared with the experimental results showing good agreement in the tendency and amplitude, especially, for the first blade frequency.

A simulation Model of the Reactor Hall Ventilation and air Conditioning Systems of ETRR-2

International Nuclear Information System (INIS)

Abd El-Rahman, M.F.

2004-01-01

Although the conceptual design for any system differs from one designer to another. each of them aims to achieve the function of the system required. the ventilation and air conditioning system of reactors hall is one of those systems that really differs but always dose its function for which it is designed. thus, ventilation and air conditioning in some reactor hall constitute only one system whereas in some other ones, they are separate systems. the Egypt Research Reactor-2 (ETRR-2)represents the second type. most studies conducted on ventilation and air conditioning simulation models either in traditional building or for research rectors show that those models were not designed similarly to the model of the hall of ETRR-2 in which ventilation and air conditioning constitute two separate systems.besides, those studies experimented on ventilation and air conditioning simulation models of reactor building predict the temperature and humidity inside these buildings at certain outside condition and it is difficult to predict when the outside conditions are changed . also those studies do not discuss the influences of reactor power changes. therefore, the present work deals with a computational study backed by infield experimental measurements of the performance of the ventilation and air conditioning systems of reactor hall during normal operation at different outside conditions as well as at different levels of reactor power

Study on Driver Visual Physiological Characteristics in Urban Traffic

Directory of Open Access Journals (Sweden)

Fengyuan Wang

2014-01-01

Full Text Available In the integrated traffic environment, human factor is always a main factor of the three elementary factors, besides the vehicle and road factor. The driver physiological and psychological characteristics have an important impact especially on traffic safety in urban road traffic conditions. Some typical traffic scenes in condition of urban road, such as light signal control at intersection, overtaking, and passing, are selected for condition analysis. An eye movement apparatus was used to obtain driver eye closure, blink frequency, and other visual physiological indicators in the traffic conditions of urban road. The regular patterns of driver visual characteristics in the corresponding scenes were analyzed in detail to provide data and theoretical support for the further research on traffic safety of urban environment from the viewpoint of driver psychology and behavior.

Physiological response of invasive mussel Limnoperna fortunei (Dunker, 1857 (Bivalvia: Mytilidae submitted to transport and experimental conditions

Directory of Open Access Journals (Sweden)

N. I. S. Cordeiro

Full Text Available Abstract Successful animal rearing under laboratory conditions for commercial processes or laboratory experiments is a complex chain that includes several stressors (e.g., sampling and transport and incurs, as a consequence, the reduction of natural animal conditions, economic losses and inconsistent and unreliable biological results. Since the invasion of the bivalve Limnoperna fortunei (Dunker, 1857 in South America, several studies have been performed to help control and manage this fouling pest in industrial plants that use raw water. Relatively little attention has been given to the laboratory rearing procedure of L. fortunei, its condition when exposed to a stressor or its acclimation into laboratory conditions. Considering this issue, the aims of this study are to (i investigate L. fortunei physiological responses when submitted to the depuration process and subsequent air transport (without water/dry condition at two temperatures, based on glycogen concentrations, and (ii monitor the glycogen concentrations in different groups when maintained for 28 days under laboratory conditions. Based on the obtained results, depuration did not affect either of the groups when they were submitted to approximately eight hours of transport. The variation in glycogen concentration among the specimens that were obtained from the field under depurated and non-depurated conditions was significant only in the first week of laboratory growth for the non-depurated group and in the second week for the depurated group. In addition, the tested temperature did not affect either of the groups that were submitted to transport. The glycogen concentrations were similar to those of the specimens that were obtained from the field in third week, which suggests that the specimens acclimated to laboratory conditions during this period of time. Thus, the results indicate that the air transport and acclimation time can be successfully incorporated into experimental studies

Morpho-physiological characterization of Indian wheat genotypes ...

African Journals Online (AJOL)

SAM

2014-05-14

May 14, 2014 ... Key words: Wheat, morphological parameters, physiological growth attributes, proline. INTRODUCTION ... few years, climatic conditions have been drastically changed and ..... Poster presented in the XXVIIIth Meeting of the.

The effect of box shape on the dynamic properties of proteins simulated under periodic boundary conditions

NARCIS (Netherlands)

Wassenaar, T.A.; Mark, A.E.

The effect of the box shape on the dynamic behavior of proteins simulated under periodic boundary conditions is evaluated. In particular, the influence of simulation boxes defined by the near-densest lattice packing (NDLP) in conjunction with rotational constraints is compared to that of standard

Tidal flushing restores the physiological condition of fish residing in degraded salt marshes.

Directory of Open Access Journals (Sweden)

Kimberly L Dibble

Full Text Available Roads, bridges, and dikes constructed across salt marshes can restrict tidal flow, degrade habitat quality for nekton, and facilitate invasion by non-native plants including Phragmites australis. Introduced P. australis contributes to marsh accretion and eliminates marsh surface pools thereby adversely affecting fish by reducing access to intertidal habitats essential for feeding, reproduction, and refuge. Our study assessed the condition of resident fish populations (Fundulus heteroclitus at four tidally restricted and four tidally restored marshes in New England invaded by P. australis relative to adjacent reference salt marshes. We used physiological and morphological indicators of fish condition, including proximate body composition (% lipid, % lean dry, % water, recent daily growth rate, age class distributions, parasite prevalence, female gravidity status, length-weight regressions, and a common morphological indicator (Fulton's K to assess impacts to fish health. We detected a significant increase in the quantity of parasites infecting fish in tidally restricted marshes but not in those where tidal flow was restored to reduce P. australis cover. Using fish length as a covariate, we found that unparasitized, non-gravid F. heteroclitus in tidally restricted marshes had significantly reduced lipid reserves and increased lean dry (structural mass relative to fish residing in reference marshes. Fish in tidally restored marshes were equivalent across all metrics relative to those in reference marshes indicating that habitat quality was restored via increased tidal flushing. Reference marshes adjacent to tidally restored sites contained the highest abundance of young fish (ages 0-1 while tidally restricted marshes contained the lowest. Results indicate that F. heteroclitus residing in physically and hydrologically altered marshes are at a disadvantage relative to fish in reference marshes but the effects can be reversed through ecological

PAVA: Physiological and Anatomical Visual Analytics for Mapping of Tissue-Specific Concentration and Time-Course Data

Science.gov (United States)

We describe the development and implementation of a Physiological and Anatomical Visual Analytics tool (PAVA), a web browser-based application, used to visualize experimental/simulated chemical time-course data (dosimetry), epidemiological data and Physiologically-Annotated Data ...

A Method of High Throughput Monitoring Crop Physiology Using Chlorophyll Fluorescence and Multispectral Imaging.

Science.gov (United States)

Wang, Heng; Qian, Xiangjie; Zhang, Lan; Xu, Sailong; Li, Haifeng; Xia, Xiaojian; Dai, Liankui; Xu, Liang; Yu, Jingquan; Liu, Xu

2018-01-01

We present a high throughput crop physiology condition monitoring system and corresponding monitoring method. The monitoring system can perform large-area chlorophyll fluorescence imaging and multispectral imaging. The monitoring method can determine the crop current condition continuously and non-destructively. We choose chlorophyll fluorescence parameters and relative reflectance of multispectral as the indicators of crop physiological status. Using tomato as experiment subject, the typical crop physiological stress, such as drought, nutrition deficiency and plant disease can be distinguished by the monitoring method. Furthermore, we have studied the correlation between the physiological indicators and the degree of stress. Besides realizing the continuous monitoring of crop physiology, the monitoring system and method provide the possibility of machine automatic diagnosis of the plant physiology. Highlights: A newly designed high throughput crop physiology monitoring system and the corresponding monitoring method are described in this study. Different types of stress can induce distinct fluorescence and spectral characteristics, which can be used to evaluate the physiological status of plants.

Physiological correlates and emotional specificity of human piloerection.

Science.gov (United States)

Benedek, Mathias; Kaernbach, Christian

2011-03-01

Piloerection is known as an indicator of strong emotional experiences. However, little is known about the physiological and emotional specificity of this psychophysiological response. In the presented study, piloerection was elicited by audio stimuli taken from music and film episodes. The physiological response accompanying the incidence of piloerection was recorded with respect to electrodermal, cardiovascular and respiratory measures and compared to a matched control condition. The employment of an optical recording system allowed for a direct and objective assessment of visible piloerection. The occurrence of piloerection was primarily accompanied by an increase of phasic electrodermal activity and increased respiration depth as compared to a matched control condition. This physiological response pattern is discussed in the context of dominant theories of human piloerection. Consideration of all available evidence suggests that emotional piloerection represents a valuable indicator of the state of being moved or touched. Copyright © 2011 Elsevier B.V. All rights reserved.

Thermal comfort, physiological responses and performance during exposure to a moderate temperature drift

DEFF Research Database (Denmark)

Schellen, Lisje; van Marken Lichtenbelt, Wouter; de Wit, Martin

2008-01-01

The objective of this research was to study the effects of a moderate temperature drift on human thermal comfort, physiological responses, productivity and performance. A dynamic thermophysiological model was used to examine the possibility of simulating human thermal responses and thermal comfort...... temperature corresponding with a neutral thermal sensation (control situation). During the experiments both physiological responses and thermal sensation were measured. Productivity and performance were assessed with a ‘Remote Performance Measurement’ (RPM) method. Physiological and thermal sensation data...

Human factors estimation methods using physiological informations

International Nuclear Information System (INIS)

Takano, Ken-ichi; Yoshino, Kenji; Nakasa, Hiroyasu

1984-01-01

To enhance the operational safety in the nuclear power plant, it is necessary to decrease abnormal phenomena due to human errors. Especially, it is essential to basically understand human behaviors under the work environment for plant maintenance workers, inspectors, and operators. On the above stand point, this paper presents the results of literature survey on the present status of human factors engineering technology applicable to the nuclear power plant and also discussed the following items: (1) Application fields where the ergonomical evaluation is needed for workers safety. (2) Basic methodology for investigating the human performance. (3) Features of the physiological information analysis among various types of ergonomical techniques. (4) Necessary conditions for the application of in-situ physiological measurement to the nuclear power plant. (5) Availability of the physiological information analysis. (6) Effectiveness of the human factors engineering methodology, especially physiological information analysis in the case of application to the nuclear power plant. The above discussions lead to the demonstration of high applicability of the physiological information analysis to nuclear power plant, in order to improve the work performance. (author)

Multiphysical Simulation of PT-CT Contact with Outer Boundary Condition

Energy Technology Data Exchange (ETDEWEB)

Chang, Se-Myong [Kunsan National Univ., Gunsan (Korea, Republic of); Kim, Hyoung Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The present study is about preliminary calculation results for these ICSP activity works, where the COMSOL Multiphysics code is used to simulate plastic deformation of a pressure tube as a result of the interaction of stress and temperature. It is shown that the thermal stress model of COMSOL is compatible to simulate the multiple heat transfers (including the radiation heat transfer and heat conduction) and stress strain in the simplified 2-D problem. The benchmark test result for radiation heat transfer is in good agreement with the analytical solution for the concentric configuration of PT(pressure tube) and CT(calandria tube). In this paper, the authors did an open computation of these multi-physical phenomena by changing the outer boundary condition of CT according to the experimental result of ICSP. A series of simulation has been done based on the benchmark test proposed by IAEA/ICSP. The unsteady multi-physics was treated some numerical models with COMSOL. The comparison with CATHENA code is verified as a good agreement as we increase the accuracy of numerical method, Gaussian quadrature. The open computation for the validation of this numerical code is still on-going, and the temperature inside and outside the PT shows a very good agreement.

Multiphysical Simulation of PT-CT Contact with Outer Boundary Condition

International Nuclear Information System (INIS)

Chang, Se-Myong; Kim, Hyoung Tae

2016-01-01

The present study is about preliminary calculation results for these ICSP activity works, where the COMSOL Multiphysics code is used to simulate plastic deformation of a pressure tube as a result of the interaction of stress and temperature. It is shown that the thermal stress model of COMSOL is compatible to simulate the multiple heat transfers (including the radiation heat transfer and heat conduction) and stress strain in the simplified 2-D problem. The benchmark test result for radiation heat transfer is in good agreement with the analytical solution for the concentric configuration of PT(pressure tube) and CT(calandria tube). In this paper, the authors did an open computation of these multi-physical phenomena by changing the outer boundary condition of CT according to the experimental result of ICSP. A series of simulation has been done based on the benchmark test proposed by IAEA/ICSP. The unsteady multi-physics was treated some numerical models with COMSOL. The comparison with CATHENA code is verified as a good agreement as we increase the accuracy of numerical method, Gaussian quadrature. The open computation for the validation of this numerical code is still on-going, and the temperature inside and outside the PT shows a very good agreement

Verification of the machinery condition monitoring technology by fault simulation tests

International Nuclear Information System (INIS)

Maehara, Takafumi; Watanabe, Yukio; Osaki, Kenji; Higuma, Koji; Nakano, Tomohito

2009-01-01

This paper shows the test items and equipments introduced by Japan Nuclear Energy Safety Organization to establish the monitoring technique for machinery conditions. From the result of vertical pump simulation tests, it was confirmed that fault analysis was impossible by measuring the accelerations on both motor and pump column pipes, however, was possible by measuring of pump shaft vibrations. Because hydraulic whirls by bearing wear had significant influences over bearing misalignments and flow rates, the monitoring trends must be done under the same condition (on bearing alignments and flow rates). We have confirmed that malfunctions of vertical pumps can be diagnosed using measured shaft vibration by ultrasonic sensors from outer surface of pump casing on the floor. (author)

Physiological system integrations with emphasis on the respiratory-cardiovascular system

Science.gov (United States)

Gallagher, R. R.

1975-01-01

The integration of two types of physiological system simulations is presented. The long term model is a circulatory system model which simulates long term blood flow variations and compartmental fluid shifts. The short term models simulate transient phenomena of the respiratory, thermoregulatory, and pulsatile cardiovascular systems as they respond to stimuli such as LBNP, exercise, and environmental gaseous variations. An overview of the interfacing approach is described. Descriptions of the variable interface for long term to short term and between the three short term models are given.

Folding and self-assembly of polypeptides: Dynamics and thermodynamics from molecular simulation

Science.gov (United States)

Fluitt, Aaron Michael

Empowered by their exquisite three-dimensional structures, or "folds," proteins carry out biological tasks with high specificity, efficiency, and fidelity. The fold that optimizes biological function represents a stable configuration of the constituent polypeptide molecule(s) under physiological conditions. Proteins and polypeptides are not static, however: battered by thermal motion, they explore a distribution of folds that is determined by the sequence of amino acids, the presence and identity of other molecules, and the thermodynamic conditions. In this dissertation, we apply molecular simulation techniques to the study of two polypeptides that have unusually diffuse distributions of folds under physiological conditions: polyglutamine (polyQ) and islet amyloid polypeptide (IAPP). Neither polyQ nor IAPP adopts a predominant fold in dilute aqueous solution, but at sufficient concentrations, both are prone to self-assemble into stable, periodic, and highly regular aggregate structures known as amyloid. The appearance of amyloid deposits of polyQ in the brain, and of IAPP in the pancreas, are associated with Huntington's disease and type 2 diabetes, respectively. A molecular view of the mechanism(s) by which polyQ and IAPP fold and self-assemble will enhance our understanding of disease pathogenesis, and it has the potential to accelerate the development of therapeutics that target early-stage aggregates. Using molecular simulations with spatial and temporal resolution on the atomic scale, we present analyses of the structural distributions of polyQ and IAPP under various conditions, both in and out of equilibrium. In particular, we examine amyloid fibers of polyQ, the IAPP dimer in solution, and single IAPP fragments at a lipid bilayer. We also benchmark the molecular models, or "force fields," available for such studies, and we introduce a novel simulation algorithm.

RANS simulation of cavitation and hull pressure fluctuation for marine propeller operating behind-hull condition

Directory of Open Access Journals (Sweden)

Kwang-Jun Paik

2013-12-01

Full Text Available Simulations of cavitation flow and hull pressure fluctuation for a marine propeller operating behind a hull using the unsteady Reynolds-Averaged Navier-Stokes equations (RANS are presented. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. Simulations are performed in design and ballast draught conditions to study the effect of cavitation number. And two propellers with slightly different geometry are simulated to validate the detectability of the numerical simulation. All simulations are performed using a commercial CFD software FLUENT. Cavitation patterns of the simulations show good agreement with the experimental results carried out in Samsung CAvitation Tunnel (SCAT. The simulation results for the hull pressure fluctuation induced by a propeller are also compared with the experimental results showing good agreement in the tendency and amplitude, especially, for the first blade frequency.

Simulation of Entropy Generation under Stall Conditions in a Centrifugal Fan

Directory of Open Access Journals (Sweden)

Lei Zhang

2014-06-01

Full Text Available Rotating stalls are generally the first instability met in turbomachinery, before surges. This 3D phenomenon is characterized by one or more stalled flow cells which rotate at a fraction of the impeller speed. The goal of the present work is to shed some light on the entropy generation in a centrifugal fan under rotating stall conditions. A numerical simulation of entropy generation is carried out with the ANSYS Fluent software which solves the Navier-Stokes equations and user defined function (UDF. The entropy generation characteristics in the centrifugal fan for five typical conditions are presented and discussed, involving the design condition, conditions on occurrence and development of stall inception, the rotating stall conditions with two throttle coefficients. The results show that the entropy generation increases after the occurrence of stall inception. The high entropy generation areas move along the circumferential and axial directions, and finally merge into one stall cell. The entropy generation rate during circumferential propagation of the stall cell is also discussed, showing that the entropy generation history is similar to sine curves in impeller and volute, and the volute tongue has a great influence on entropy generation in the centrifugal fan.

DigitalHuman (DH): An Integrative Mathematical Model ofHuman Physiology

Science.gov (United States)

Hester, Robert L.; Summers, Richard L.; lIescu, Radu; Esters, Joyee; Coleman, Thomas G.

2010-01-01

Mathematical models and simulation are important tools in discovering the key causal relationships governing physiological processes and improving medical intervention when physiological complexity is a central issue. We have developed a model of integrative human physiology called DigitalHuman (DH) consisting of -5000 variables modeling human physiology describing cardiovascular, renal, respiratory, endocrine, neural and metabolic physiology. Users can view time-dependent solutions and interactively introduce perturbations by altering numerical parameters to investigate new hypotheses. The variables, parameters and quantitative relationships as well as all other model details are described in XML text files. All aspects of the model, including the mathematical equations describing the physiological processes are written in XML open source, text-readable files. Model structure is based upon empirical data of physiological responses documented within the peer-reviewed literature. The model can be used to understand proposed physiological mechanisms and physiological interactions that may not be otherwise intUitively evident. Some of the current uses of this model include the analyses of renal control of blood pressure, the central role of the liver in creating and maintaining insulin resistance, and the mechanisms causing orthostatic hypotension in astronauts. Additionally the open source aspect of the modeling environment allows any investigator to add detailed descriptions of human physiology to test new concepts. The model accurately predicts both qualitative and more importantly quantitative changes in clinically and experimentally observed responses. DigitalHuman provides scientists a modeling environment to understand the complex interactions of integrative physiology. This research was supported by.NIH HL 51971, NSF EPSCoR, and NASA

Study and simulation of irradiated zirconium alloys fracture under type RIA accidental loading conditions; Comprehension et modelisation de la rupture d'alliages de zirconium irradies en conditions accidentelles de type RIA

Energy Technology Data Exchange (ETDEWEB)

Le Saux, M. [CEA Saclay, Dept. des Materiaux pour le Nucleaire (DEN/DANS/DMN/SEMI), 91 - Gif-sur-Yvette (France)

2008-07-01

The thesis aims to study and simulate the mechanical behavior under Reactivity Initiated Accident loading conditions, of the Zircaloy 4 fuel claddings, irradiated or not. It also aims to characterize and simulate the behavior and the fracture under RIA loading conditions of hydrided Zircaloy 4 non irradiated. This study proposes an experimental approach and a simulation. (A.L.B.)

Physiological indices of seawater readiness in postspawning steelhead kelts

Science.gov (United States)

Buelow, Jessica; Moffitt, Christine M.

2015-01-01

Management goals to improve the recovery of steelhead (Oncorhynchus mykiss) stocks at risk of extinction include increasing the proportion of postspawning fish that survive and spawn again. To be successful, postspawning steelhead (kelts) migrating downstream to the ocean must prepare physiologically and physically for a seawater transition. We sampled blood, gill filaments, and evaluated the external condition of migrating kelts from an ESA-listed population in the Snake/Columbia River system over two consecutive years to evaluate their physiological readiness for transition to seawater. We chose attributes often considered as measures of preparation for seawater in juveniles, including gill Na+,K+ ATPase activity, plasma electrolytes and hormones to consider factors related to external condition, size and sex. We found kelts in good external condition had plasma profiles similar to downstream-migrating smolts. In addition, we found more than 80% of kelts ranked in good external condition had smolt-like body silvering. We compared measures from migrating kelts with samples obtained from hatchery fish at the time of spawning to confirm that Na+, K+ ATPase activity in kelts was significantly elevated over spawning fish. We found significant differences in gill Na+, K+ ATPase activity in migrating kelts between the years of sampling, but little indication of influence of fish condition. We conclude that the postspawning steelhead sampled exhibited a suite of behaviours, condition and physiology characteristic of fish prepared for successful transition to a seawater environment.

DSMC Simulation of Separated Flows About Flared Bodies at Hypersonic Conditions

Science.gov (United States)

Moss, James N.

2000-01-01

This paper describes the results of a numerical study of interacting hypersonic flows at conditions that can be produced in ground-based test facilities. The computations are made with the direct simulation Monte Carlo (DSMC) method of Bird. The focus is on Mach 10 flows about flared axisymmetric configurations, both hollow cylinder flares and double cones. The flow conditions are those for which experiments have been or will be performed in the ONERA R5Ch low-density wind tunnel and the Calspan-University of Buffalo Research Center (CUBRC) Large Energy National Shock (LENS) tunnel. The range of flow conditions, model configurations, and model sizes provides a significant range of shock/shock and shock/boundary layer interactions at low Reynolds number conditions. Results presented will highlight the sensitivity of the calculations to grid resolution, contrast the differences in flow structure for hypersonic cold flows and those of more energetic but still low enthalpy flows, and compare the present results with experimental measurements for surface heating, pressure, and extent of separation.

Leaching behavior of a simulated bituminized radioactive waste form under deep geological conditions

International Nuclear Information System (INIS)

Nakayama, Shinichi; Iida, Yoshihisa; Nagano, Tetsushi; Akimoto, Toshiyuki

2003-01-01

The leaching behavior of a simulated bituminized waste form was studied to acquire data for the performance assessment of the geologic disposal of bituminized radioactive waste. Laboratory-scale leaching tests were performed for radioactive and non-radioactive waste specimens simulating bituminized waste of a French reprocessing company, COGEMA. The simulated waste was contacted with deionized water, an alkaline solution (0.03-mol/l KOH), and a saline solution (0.5-mol/l KCl) under atmospheric and anoxic conditions. The concentrations of Na, Ba, Cs, Sr, Np, Pu, NO 3 , SO 4 and I in the leachates were determined. Swelling of the bituminized waste progressed in deionized water and KOH. The release of the soluble components, Na and Cs, was enhanced by the swelling, and considered to be diffusion-controlled in the swelled layers of the specimens. The release of sparingly soluble components such as Ba and Np was solubility-limited in addition to the progression of leaching. Neptunium, a redox-sensitive element, showed a distinct difference in release between anoxic and atmospheric conditions. The elemental release from the bituminized waste specimens leached in the KCl was very low, which is likely due to the suppression of swelling of the specimens at high ionic strength. (author)

From physiological psychology to psychological physiology: Postnonclassical approach to ethnocultural phenomena.

Directory of Open Access Journals (Sweden)

Asmolov, A.G.

2015-07-01

Full Text Available In modern science, along with the “classic” and “non-classical” approach to solving fundamental and applied problems, there is an actively developing “postnonclassical” research paradigm. This renovation of general scientific methodology has been accompanied by the emergence of new experimental technologies and new scientific research directions based on them. “Social psychophysiology” is one such direction. It is formed within the frame of postnonclassical methodology at the intersection of neuroscience and psychology. This work is devoted to the analytical review of the methods, achievements and prospects of contemporary social neuroscience and social psychophysiology studying brain structures that are specifically related to the implementation of social forms of behavior and intercultural communication. Physiological studies of brain activity during social interaction processes, which are simulated using virtual reality environments, are analyzed, and the physiological approach to the study of the brain mechanisms associated with social perception, social cognition and social behavior is used. Along with the analysis of psychophysiological studies of the mechanisms of social perception and social cognition, we discuss the theories of “Brain Reading” and “Theory of Mind” and the underlying data concerning “Gnostic neurons recognition of persons and recognition of emotional facial expressions”, “mirror neurons”, “emotional resonance” and “cognitive resonance”. Particular emphasis is placed on the discussion of a fundamentally new trend in the study of the relationship between the brain and culture (i.e., “cultural neuroscience”. Related to this connection, the following topics are raised: physiological mechanisms protecting the “individual distance” in communication between members of a personified community, psychophysiological approaches to the study of cross-cultural differences, physiological

Direct numerical simulation of turbulent flows over superhydrophobic surfaces with gas pockets using linearized boundary conditions

Science.gov (United States)

Seo, Jongmin; Bose, Sanjeeb; Garcia-Mayoral, Ricardo; Mani, Ali

2012-11-01

Superhydrophobic surfaces are shown to be effective for surface drag reduction under laminar regime by both experiments and simulations (see for example, Ou and Rothstein, Phys. Fluids 17:103606, 2005). However, such drag reduction for fully developed turbulent flow maintaining the Cassie-Baxter state remains an open problem due to high shear rates and flow unsteadiness of turbulent boundary layer. Our work aims to develop an understanding of mechanisms leading to interface breaking and loss of gas pockets due to interactions with turbulent boundary layers. We take advantage of direct numerical simulation of turbulence with slip and no-slip patterned boundary conditions mimicking the superhydrophobic surface. In addition, we capture the dynamics of gas-water interface, by deriving a proper linearized boundary condition taking into account the surface tension of the interface and kinematic matching of interface deformation and normal velocity conditions on the wall. We will show results from our simulations predicting the dynamical behavior of gas pocket interfaces over a wide range of dimensionless surface tensions. Supported by the Office of Naval Research and the Kwanjeong Educational Scholarship Foundation.

Clinical usefulness of physiological components obtained by factor analysis

International Nuclear Information System (INIS)

Ohtake, Eiji; Murata, Hajime; Matsuda, Hirofumi; Yokoyama, Masao; Toyama, Hinako; Satoh, Tomohiko.

1989-01-01

The clinical usefulness of physiological components obtained by factor analysis was assessed in 99m Tc-DTPA renography. Using definite physiological components, another dynamic data could be analyzed. In this paper, the dynamic renal function after ESWL (Extracorporeal Shock Wave Lithotripsy) treatment was examined using physiological components in the kidney before ESWL and/or a normal kidney. We could easily evaluate the change of renal functions by this method. The usefulness of a new analysis using physiological components was summarized as follows: 1) The change of a dynamic function could be assessed in quantity as that of the contribution ratio. 2) The change of a sick condition could be morphologically evaluated as that of the functional image. (author)

2D simulation and performance evaluation of bifacial rear local contact c-Si solar cells under variable illumination conditions

KAUST Repository

Katsaounis, Theodoros; Kotsovos, Konstantinos; Gereige, Issam; Al-Saggaf, Ahmed; Tzavaras, Athanasios

2017-01-01

A customized 2D computational tool has been developed to simulate bifacial rear local contact PERC type PV structures based on the numerical solution of the transport equations through the finite element method. Simulations were performed under various device material parameters and back contact geometry configurations in order to optimize bifacial solar cell performance under different simulated illumination conditions. Bifacial device maximum power output was also compared with the monofacial equivalent one and the industrial standard Al-BSF structure. The performance of the bifacial structure during highly diffused irradiance conditions commonly observed in the Middle East region due to high concentrations of airborne dust particles was also investigated. Simulation results demonstrated that such conditions are highly favorable for the bifacial device because of the significantly increased diffuse component of the solar radiation which enters the back cell surface.

2D simulation and performance evaluation of bifacial rear local contact c-Si solar cells under variable illumination conditions

KAUST Repository

Katsaounis, Theodoros

2017-09-18

A customized 2D computational tool has been developed to simulate bifacial rear local contact PERC type PV structures based on the numerical solution of the transport equations through the finite element method. Simulations were performed under various device material parameters and back contact geometry configurations in order to optimize bifacial solar cell performance under different simulated illumination conditions. Bifacial device maximum power output was also compared with the monofacial equivalent one and the industrial standard Al-BSF structure. The performance of the bifacial structure during highly diffused irradiance conditions commonly observed in the Middle East region due to high concentrations of airborne dust particles was also investigated. Simulation results demonstrated that such conditions are highly favorable for the bifacial device because of the significantly increased diffuse component of the solar radiation which enters the back cell surface.

The emergence of Applied Physiology within the discipline of Physiology.

Science.gov (United States)

Tipton, Charles M

2016-08-01

Despite the availability and utilization of the physiology textbooks authored by Albrecht von Haller during the 18th century that heralded the modern age of physiology, not all physicians or physiologists were satisfied with its presentation, contents, or application to medicine. Initial reasons were fundamental disagreements between the "mechanists," represented by Boerhaave, Robinson, and von Haller, and the "vitalists," represented by the faculty and graduates of the Montpellier School of Medicine in France, notably, Bordeu and Barthez. Subsequently, objections originated from Europe, United Kingdom, and the United States in publications that focused not only on the teaching of physiology to medical and secondary students, but on the specific applications of the content of physiology to medicine, health, hygiene, pathology, and chronic diseases. At the turn of the 20th century, texts began to appear with applied physiology in their titles and in 1926, physician Samson Wright published a textbook entitled Applied Physiology that was intended for both medical students and the medical profession. Eleven years later, physicians Best and Taylor published The Physiological Basis of Medical Practice: A University of Toronto Texbook in Applied Physiology Although both sets of authors defined the connection between applied physiology and physiology, they failed to define the areas of physiology that were included within applied physiology. This was accomplished by the American Physiological Society (APS) Publications Committee in 1948 with the publication of the Journal of Appplied Physiology, that stated the word "applied" would broadly denote human physiology whereas the terms stress and environment would broadly include work, exercise, plus industrial, climatic and social factors. NIH established a study section (SS) devoted to applied physiology in 1964 which remained active until 2001 when it became amalgamated into other SSs. Before the end of the 20th century when

Influence of different process settings conditions on the accuracy of micro injection molding simulations: an experimental validation

DEFF Research Database (Denmark)

Tosello, Guido; Gava, Alberto; Hansen, Hans Nørgaard

2009-01-01

Currently available software packages exhibit poor results accuracy when performing micro injection molding (µIM) simulations. However, with an appropriate set-up of the processing conditions, the quality of results can be improved. The effects on the simulation results of different and alternative...... process conditions are investigated, namely the nominal injection speed, as well as the cavity filling time and the evolution of the cavity injection pressure as experimental data. In addition, the sensitivity of the results to the quality of the rheological data is analyzed. Simulated results...... are compared with experiments in terms of flow front position at part and micro features levels, as well as cavity injection filling time measurements....

Cosmological Simulations with Scale-Free Initial Conditions. I. Adiabatic Hydrodynamics

International Nuclear Information System (INIS)

Owen, J.M.; Weinberg, D.H.; Evrard, A.E.; Hernquist, L.; Katz, N.

1998-01-01

We analyze hierarchical structure formation based on scale-free initial conditions in an Einstein endash de Sitter universe, including a baryonic component with Ω bary = 0.05. We present three independent, smoothed particle hydrodynamics (SPH) simulations, performed at two resolutions (32 3 and 64 3 dark matter and baryonic particles) and with two different SPH codes (TreeSPH and P3MSPH). Each simulation is based on identical initial conditions, which consist of Gaussian-distributed initial density fluctuations that have a power spectrum P(k) ∝ k -1 . The baryonic material is modeled as an ideal gas subject only to shock heating and adiabatic heating and cooling; radiative cooling and photoionization heating are not included. The evolution is expected to be self-similar in time, and under certain restrictions we identify the expected scalings for many properties of the distribution of collapsed objects in all three realizations. The distributions of dark matter masses, baryon masses, and mass- and emission-weighted temperatures scale quite reliably. However, the density estimates in the central regions of these structures are determined by the degree of numerical resolution. As a result, mean gas densities and Bremsstrahlung luminosities obey the expected scalings only when calculated within a limited dynamic range in density contrast. The temperatures and luminosities of the groups show tight correlations with the baryon masses, which we find can be well represented by power laws. The Press-Schechter (PS) approximation predicts the distribution of group dark matter and baryon masses fairly well, though it tends to overestimate the baryon masses. Combining the PS mass distribution with the measured relations for T(M) and L(M) predicts the temperature and luminosity distributions fairly accurately, though there are some discrepancies at high temperatures/luminosities. In general the three simulations agree well for the properties of resolved groups, where a group

Physiologically based pharmacokinetics model for estimating urinary excretion of short half-life nuclides in nuclear medicine

International Nuclear Information System (INIS)

Akahane, K.; Kai, M.; Konishi, E.; Kusama, T.; Aoki, Y.

1995-01-01

The biokinetic model in ICRP 53 is used for calculating absorbed dose to each organ of a patient in nuclear medicine. The ICRP model is a simple compartment model based on human data; however, the model cannot produce the biokinetics of radiopharmaceuticals under various physiological conditions. On the other hand, a physiologically based pharmacokinetics model (PBPK model) can describe the flow of radiopharmaceuticals as a compartment model for any physiological conditions theoretically. The PBPK model was applied especially for the kidney-bladder dynamics, and similar results obtained compared with the ICRP model. This suggests the possibility of the PBPK model for predicting the biokinetics of radiopharmaceuticals under various physiological conditions. (Author)

PyMUS: Python-Based Simulation Software for Virtual Experiments on Motor Unit System.

Science.gov (United States)

Kim, Hojeong; Kim, Minjung

2018-01-01

We constructed a physiologically plausible computationally efficient model of a motor unit and developed simulation software that allows for integrative investigations of the input-output processing in the motor unit system. The model motor unit was first built by coupling the motoneuron model and muscle unit model to a simplified axon model. To build the motoneuron model, we used a recently reported two-compartment modeling approach that accurately captures the key cell-type-related electrical properties under both passive conditions (somatic input resistance, membrane time constant, and signal attenuation properties between the soma and the dendrites) and active conditions (rheobase current and afterhyperpolarization duration at the soma and plateau behavior at the dendrites). To construct the muscle unit, we used a recently developed muscle modeling approach that reflects the experimentally identified dependencies of muscle activation dynamics on isometric, isokinetic and dynamic variation in muscle length over a full range of stimulation frequencies. Then, we designed the simulation software based on the object-oriented programing paradigm and developed the software using open-source Python language to be fully operational using graphical user interfaces. Using the developed software, separate simulations could be performed for a single motoneuron, muscle unit and motor unit under a wide range of experimental input protocols, and a hierarchical analysis could be performed from a single channel to the entire system behavior. Our model motor unit and simulation software may represent efficient tools not only for researchers studying the neural control of force production from a cellular perspective but also for instructors and students in motor physiology classroom settings.

Numerical Simulation of single-stage axial fan operation under dusty flow conditions

Science.gov (United States)

Minkov, L. L.; Pikushchak, E. V.

2017-11-01

Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

Effects of Long-Term Simulated Martian Conditions on a Freeze-Dried and Homogenized Bacterial Permafrost Community

Science.gov (United States)

Hansen, Aviaja A.; Jenson, Lars L.; Kristoffersen, Tommy; Mikkelsen, Karina; Merrison, Jonathan; Finster, Kai W.; Lomstein, Bente Aa.

2009-03-01

Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation, freeze-thaw cycles, the atmospheric gas composition, and pressure. The homogenized permafrost cores were subjected to repeated cycles of UV radiation for 3 h followed by 27 h without irradiation. The effects of the simulation conditions on the concentrations of biomolecules; numbers of viable, dead, and cultured bacteria; as well as the community structure were determined. Simulated martian conditions resulted in a significant reduction of the concentrations of DNA and amino acids in the uppermost 1.5 mm of the soil core. The total number of bacterial cells was reduced in the upper 9 mm of the soil core, while the number of viable cells was reduced in the upper 15 mm. The number of cultured aerobic bacteria was reduced in the upper 6 mm of the soil core, whereas the community structure of cultured anaerobic bacteria was relatively unaffected by the exposure conditions. As explanations for the observed changes, we propose three causes that might have been working on the biological material either individually or synergistically: (i) UV radiation, (ii) UV-generated reactive oxygen species, and (iii) freeze-thaw cycles. Currently, the production and action of reactive gases is only hypothetical and will be a central subject in future investigations. Overall, we conclude that in a stable environment (no wind-/pressure-induced mixing) biological material is efficiently shielded by a 2 cm thick layer of dust, while it is relatively rapidly destroyed in the surface layer, and that biomolecules like proteins and polynucleotides are more resistant to destruction than living biota.

Extraction of Plant Physiological Status from Hyperspectral Signatures Using Machine Learning Methods

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Daniel Doktor

2014-12-01

Full Text Available The machine learning method, random forest (RF, is applied in order to derive biophysical and structural vegetation parameters from hyperspectral signatures. Hyperspectral data are, among other things, characterized by their high dimensionality and autocorrelation. Common multivariate regression approaches, which usually include only a limited number of spectral indices as predictors, do not make full use of the available information. In contrast, machine learning methods, such as RF, are supposed to be better suited to extract information on vegetation status. First, vegetation parameters are extracted from hyperspectral signatures simulated with the radiative transfer model, PROSAIL. Second, the transferability of these results with respect to laboratory and field measurements is investigated. In situ observations of plant physiological parameters and corresponding spectra are gathered in the laboratory for summer barley (Hordeum vulgare. Field in situ measurements focus on winter crops over several growing seasons. Chlorophyll content, Leaf Area Index and phenological growth stages are derived from simulated and measured spectra. RF performs very robustly and with a very high accuracy on PROSAIL simulated data. Furthermore, it is almost unaffected by introduced noise and bias in the data. When applied to laboratory data, the prediction accuracy is still good (C\\(_{ab}\\: \\(R^2\\ = 0.94/ LAI: \\(R^2\\ = 0.80/BBCH (Growth stages of mono-and dicotyledonous plants : \\(R^2\\ = 0.91, but not as high as for simulated spectra. Transferability to field measurements is given with prediction levels as high as for laboratory data (C\\(_{ab}\\: \\(R^2\\ = 0.89/LAI: \\(R^2\\ = 0.89/BBCH: \\(R^2\\ = \\(\\sim\\0.8. Wavelengths for deriving plant physiological status based on simulated and measured hyperspectral signatures are mostly selected from appropriate spectral regions (both field and laboratory: 700–800 nm regressing on C\\(_{ab}\\ and 800–1300

Numerical simulation of hydrodynamic performance of ship under oblique conditions

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CHEN Zhiming

2018-02-01

Full Text Available [Objectives] This paper is intended to study the viscous flow field around a ship under oblique conditions and provide a research basis for ship maneuverability. [Methods] Using commercial software STRA-CCM+, the SST k-ω turbulence model is selected to predict the hydrodynamic performance of the KVLCC2 model at different drift angles, and predict the hull flow field. The pressure distribution of the ship model at different drift angles is observed and the vortex shedding of the ship's hull and constraint streamlines on the hull's surface are also observed. [Results] The results show that numerical simulation can satisfy the demands of engineering application in the prediction of the lateral force, yaw moment and hull surface pressure distribution of a ship. [Conclusions] The research results of this paper can provide valuable references for the study of the flow separation phenomenon under oblique conditions.

Simulations of the design basis accident at conditions of power increase and the o transient of MSIV at overpressure conditions of the Laguna Verde Power Station

International Nuclear Information System (INIS)

Araiza M, E.; Nunez C, A.

2001-01-01

This document presents the analysis of the simulation of the loss of coolant accident at uprate power conditions, that is 2027 MWt (105% of the current rated power of 1931MWt). This power was reached allowing an increase in the turbine steam flow rate without changing the steam dome pressure value at its rated conditions (1020 psiaJ. There are also presented the results of the simulation of the main steam isolation va/ve transient at overpressure conditions 1065 psia and 1067 MWt), for Laguna Verde Nuclear Power Station. Both simulations were performed with the best estimate computer code TRA C BF1. The results obtained in the loss of coolant accident show that the emergency core coolant systems can recover the water level in the core before fuel temperature increases excessively, and that the peak pressure reached in the drywell is always below its design pressure. Therefore it is concluded that the integrity of the containment is not challenged during a loss of coolant accident at uprate power conditions.The analysis of the main steam isolation valve transients at overpressure conditions, and the analysis of the particular cases of the failure of one to six safety relief valves to open, show that the vessel peak pressures are below the design pressure and have no significant effect on vessel integrity. (Author)

[Effects of simulated acid rain on water physiological characteristics of Myrica rubra seedlings].

Science.gov (United States)

Yaho, Zhao-bin; Jiang, Hong; Yu, Shu-quan; Lu, Mei-juan

2011-08-01

Taking the seedlings of typical subtropical economic tree species Myrica rubra in Zhejiang Province as test materials, a pot experiment was conducted to study their water physiological characteristics under effects of simulated acid rain (pH 2.5 and pH 4.0), with water (pH 5.6) as the control. Season, year, and acid rain all had significant effects on the photosynthetic rate (Pn). Among the treatments, the Pn had a greater difference in summer than in spring and autumn, and was higher in treatment acid rain (pH 4.0). Season, year, acid rain, and the interactions of season and year and of the three factors had significant effects on the stomata conductance (Gs), and also, the Gs had a greater difference among the treatments in summer than in spring and autumn. Acid rain had inhibitory effect on Gs. Season, year, acid rain, and the interactions of season and year and of season and acid rain affected the transpiration rate (Tr) significantly. Same as Pn and Gs, the Tr had a greater difference among the treatments in summer than in spring and autumn. Acid rain (pH 2.5) had the strongest inhibitory effect on Tr. Acid rain and the interactions of season and year and of season and acid rain had significant effects on the water use efficiency (WUE), and acid rain (pH 2.5) had definitely positive effect on the WUE.

Physiological and biochemical response to Omega-3 plus as a dietary supplement to growing goats under hot summer conditions

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Fatma Edrees Ibrahim Teama

2016-04-01

Full Text Available ABSTRACT The objective of the present study was to assess the effect of dietary supplementation of Omega-3 plus on some the physiological and biochemical traits in growing Baladi goats under hot summer conditions. Thirty-four growing male goats (4-5 months old were randomly divided into two equal groups. Animals in group 1 were fed a concentrate feed mixture (CFM, which was the control group. Goats in group 2 (the experimental group were offered Omega-3 plus (1,000 mg/animal day-1 (30% fish oil, containing 18% eicosapentaenoic acid and 12% docosahexaenoic acid + 100 mg wheat germ oil (0.22% tocopherols daily in addition to the basal diet for four months (the experimental period during the hot summer season. Body weight (BW changes of both groups were recorded monthly during the experiment. Blood samples were collected monthly, and total protein, immunoglobulin G (IgG, total cholesterol, triglycerides, liver enzymes (AST and ALT, blood urea nitrogen, serum creatinine, and thyroid hormones (T3 and T4 were estimated. A significant increase in the live BW of growing goats was recorded as a result of dietary supplementation of Omega-3 plus. Total protein, IgG, and T3 levels were higher than those obtained with control. In contrast, total cholesterol, triglycerides, urea, ALT, and AST levels were significantly reduced. The serum concentration of creatinine and T4 levels was indistinguishable from those of control. Addition of Omega-3 plus as a dietary supplement to growing goats under hot summer conditions increases their daily weight gain and improves their general physiological and biochemical status by decreasing total cholesterol, triglycerides, urea, ALT, and AST. It is thus suggested that Omega-3 plus should be used as a supplement in the growth period of goats.

Anatomical physiology of spatial extinction.

Science.gov (United States)

Ciçek, Metehan; Gitelman, Darren; Hurley, Robert S E; Nobre, Anna; Mesulam, Marsel

2007-12-01

Neurologically intact volunteers participated in a functional magnetic resonance imaging experiment that simulated the unilateral (focal) and bilateral (global) stimulations used to elicit extinction in patients with hemispatial neglect. In peristriate areas, attentional modulations were selectively sensitive to contralaterally directed attention. A higher level of mapping was observed in the intraparietal sulcus (IPS), inferior parietal lobule (IPL), and inferior frontal gyrus (IFG). In these areas, there was no distinction between contralateral and ipsilateral focal attention, and the need to distribute attention globally led to greater activity than either focal condition. These physiological characteristics were symmetrically distributed in the IPS and IFG, suggesting that the effects of unilateral lesions in these 2 areas can be compensated by the contralateral hemisphere. In the IPL, the greater activation by the bilateral attentional mode was seen only in the right hemisphere. Its contralateral counterpart displayed equivalent activations when attention was distributed to the right, to the left, or bilaterally. Within the context of this experiment, the IPL of the right hemisphere emerged as the one area where unilateral lesions can cause the most uncompensated and selective impairment of global attention (without interfering with unilateral attention to either side), giving rise to the phenomenon of extinction.

Effect of fabric stuff of work clothing on the physiological strain index at hot conditions in the climatic chamber

Directory of Open Access Journals (Sweden)

Habibollah Dehghan

2014-01-01

Full Text Available Aims: The purpose of the present study was to evaluate the effect of fabric stuff of work clothing that are widely used in Iran industries on the physiological strain index (PSI at hot conditions in the climatic chamber. Materials and Methods: This interventional study was performed upon 18 male students in 16 trials, which included combination of four kinds of work clothing (13.7% viscose (VIS 86.3% polyester(PES, 30.2% cotton [CT]-69.8% PES, 68.5% CT-31.5% PES, 100% CT, two activity levels (light and moderate and two kinds of climatic conditions included hot-wet (T a = 35, RH = 70% and hot-dry (T a = 38, RH = 40%. During each trial, the RH and core temperature was recorded once a minute and then PSI was calculated. Data were analyzed by using SPSS-16 software. Results: The results showed that in hot-wet conditions, the least value of PSI in light and moderate activities was related to 100% CT clothing and 30.2% CT-69.8% PES clothing, respectively. In hot-dry conditions, the least value of PSI in both of activities was related to 30.2% CT-69.8% PES clothing. The mean value of PSI in hot-wet conditions, during moderate activity had significant difference for various clothing types (P = 0.044. Conclusion: The research findings showed that for a heat strain reduction in hot-wet conditions at light activity level, 100% CT clothing is suitable. Furthermore, at moderate activity level, 30.2% CT-69.8% PES clothing and in hot-dry conditions, 30.2% CT-69.8% PES is suitable.

Transients from initial conditions based on Lagrangian perturbation theory in N-body simulations II: the effect of the transverse mode

International Nuclear Information System (INIS)

Tatekawa, Takayuki

2014-01-01

We study the initial conditions for cosmological N-body simulations for precision cosmology. In general, Zel'dovich approximation has been applied for the initial conditions of N-body simulations for a long time. These initial conditions provide incorrect higher-order growth. These error caused by setting up the initial conditions by perturbation theory is called transients. We investigated the impact of transient on non-Gaussianity of density field by performing cosmological N-body simulations with initial conditions based on first-, second-, and third-order Lagrangian perturbation theory in previous paper. In this paper, we evaluates the effect of the transverse mode in the third-order Lagrangian perturbation theory for several statistical quantities such as power spectrum and non-Gaussianty. Then we clarified that the effect of the transverse mode in the third-order Lagrangian perturbation theory is quite small

Simulation of experiment on aerosol behaviour at severe accident conditions in the LACE experimental facility with the ASTEC CPA code

International Nuclear Information System (INIS)

Kljenak, I.; Mavko, B.

2007-01-01

The experiment LACE LA4 on thermal-hydraulics and aerosol behavior in a nuclear power plant containment, which was performed in the LACE experimental facility, was simulated with the ASTEC CPA module of the severe accident computer code ASTEC V1.2. The specific purpose of the work was to assess the capability of the module (code) to simulate thermal-hydraulic conditions and aerosol behavior in the containment of a light-water-reactor nuclear power plant at severe accident conditions. The test was simulated with boundary conditions, described in the experiment report. Results of thermal-hydraulic conditions in the test vessel, as well as dry aerosol concentrations in the test vessel atmosphere, are compared to experimental results and analyzed. (author)

Physiological and lactation responses of Egyptian dairy Baladi goats to natural thermal stress under subtropical environmental conditions.

Science.gov (United States)

El-Tarabany, Mahmoud S; El-Tarabany, Akram A; Atta, Mostafa A

2017-01-01

The objective of this study was to evaluate the impact of thermal stress on milk production and physiological traits of Baladi goats under subtropical Egyptian conditions. Sixty dairy Baladi goats were exposed to three different levels of temperature-humidity index (THI), including low (less than 70), moderate (over 70 and up to 80), and high levels (over 80). The influence of THI on the milk composition and physiological, hematological, and biochemical traits was investigated. Rectal temperature and respiration rate were significantly greater at the higher THI than at low and moderate THI (p = 0.016 and 0.002, respectively). Baladi goats had decreased daily milk yield in a rate of 27.3 and 19.3 % at high THI level, compared with low and moderate THI, respectively (p = 0.031). On the contrary, no significant differences have been reported in protein, fat, and total solids percentages at different THI levels. Total leucocyte count, serum glucose, and total protein were significantly reduced at high THI in comparison with low and moderate THI levels (p = 0.043, 0.001, and 0.001, respectively). However, dairy goats maintained relatively stable estimates for erythrocytes count, hemoglobin, serum triglycerides, cholesterol, catalase, total antioxidant capacity, and triiodothyronine at different THI levels. Our results indicate that dairy Baladi goats can tolerate THI levels up to 80; however, variable reduction in milk yield and few biochemical (serum total protein and glucose) and hematological (leucocytes count) parameters have been reported at a THI level higher than 80.

Employee subjective well-being and physiological functioning: An integrative model

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Lauren Kuykendall

2015-06-01

Full Text Available Research shows that worker subjective well-being influences physiological functioning—an early signal of poor health outcomes. While several theoretical perspectives provide insights on this relationship, the literature lacks an integrative framework explaining the relationship. We develop a conceptual model explaining the link between subjective well-being and physiological functioning in the context of work. Integrating positive psychology and occupational stress perspectives, our model explains the relationship between subjective well-being and physiological functioning as a result of the direct influence of subjective well-being on physiological functioning and of their common relationships with work stress and personal resources, both of which are influenced by job conditions.

Employee subjective well-being and physiological functioning: An integrative model.

Science.gov (United States)

Kuykendall, Lauren; Tay, Louis

2015-01-01

Research shows that worker subjective well-being influences physiological functioning-an early signal of poor health outcomes. While several theoretical perspectives provide insights on this relationship, the literature lacks an integrative framework explaining the relationship. We develop a conceptual model explaining the link between subjective well-being and physiological functioning in the context of work. Integrating positive psychology and occupational stress perspectives, our model explains the relationship between subjective well-being and physiological functioning as a result of the direct influence of subjective well-being on physiological functioning and of their common relationships with work stress and personal resources, both of which are influenced by job conditions.

The Effect of Simulated Microgravity Environment of RWV Bioreactors on Surface Reactions and Adsorption of Serum Proteins on Bone-bioactive Microcarriers

Science.gov (United States)

Radin, Shula; Ducheyne, P.; Ayyaswamy, P. S.

2003-01-01

Biomimetically modified bioactive materials with bone-like surface properties are attractive candidates for use as microcarriers for 3-D bone-like tissue engineering under simulated microgravity conditions of NASA designed rotating wall vessel (RWV) bioreactors. The simulated microgravity environment is attainable under suitable parametric conditions of the RWV bioreactors. Ca-P containing bioactive glass (BG), whose stimulatory effect on bone cell function had been previously demonstrated, was used in the present study. BG surface modification via reactions in solution, resulting formation of bone-like minerals at the surface and adsorption of serum proteins is critical for obtaining the stimulatory effect. In this paper, we report on the major effects of simulated microgravity conditions of the RWV on the BG reactions surface reactions and protein adsorption in physiological solutions. Control tests at normal gravity were conducted at static and dynamic conditions. The study revealed that simulated microgravity remarkably enhanced reactions involved in the BG surface modification, including BG dissolution, formation of bone-like minerals at the surface and adsorption of serum proteins. Simultaneously, numerical models were developed to simulate the mass transport of chemical species to and from the BG surface under normal gravity and simulated microgravity conditions. The numerical results showed an excellent agreement with the experimental data at both testing conditions.

Effect of weather data aggregation on regional crop simulation for different crops, production conditions, and response variables

NARCIS (Netherlands)

Zhao, Gang; Hoffmann, Holger; Bussel, Van L.G.J.; Enders, Andreas; Specka, Xenia; Sosa, Carmen; Yeluripati, Jagadeesh; Tao, Fulu; Constantin, Julie; Raynal, Helene; Teixeira, Edmar; Grosz, Balázs; Doro, Luca; Zhao, Zhigan; Nendel, Claas; Kiese, Ralf; Eckersten, Henrik; Haas, Edwin; Vanuytrecht, Eline; Wang, Enli; Kuhnert, Matthias; Trombi, Giacomo; Moriondo, Marco; Bindi, Marco; Lewan, Elisabet; Bach, Michaela; Kersebaum, Kurt Christian; Rötter, Reimund; Roggero, Pier Paolo; Wallach, Daniel; Cammarano, Davide; Asseng, Senthold; Krauss, Gunther; Siebert, Stefan

2015-01-01

We assessed the weather data aggregation effect (DAE) on the simulation of cropping systems for different crops, response variables, and production conditions. Using 13 processbased crop models and the ensemble mean, we simulated 30 yr continuous cropping systems for 2 crops (winter wheat and

Impact of Different Personal Protective Clothing on Wildland Firefighters' Physiological Strain.

Science.gov (United States)

Carballo-Leyenda, Belén; Villa, José G; López-Satué, Jorge; Rodríguez-Marroyo, Jose A

2017-01-01

Wildfire firefighting is an extremely demanding occupation performed under hot environment. The use of personal protective clothing (PPC) is needed to protect subjects from the thermal exposure. However, the additional use of PPC may increase the wildland firefighters' physiological strain, and consequently limit their performance. The aim of this study was to analyze the effect of four different PPC on the physiological strain of wildland firefighters under moderate conditions (30°C and 30% RH). Eight active and healthy wildland firefighters performed a submaximal walking test wearing a traditional short sports gear and 4 different PPC. The materials combination (viscose, Nomex, Kevlar, P-140 and fire resistant cotton) used during the PPC manufacturing process was different. During all tests, to simulate a real scenario subjects wore a backpack pump (20 kg). Heart rate, respiratory gas exchange, gastrointestinal temperature, blood lactate concentration, perceived exertion and temperature and humidity underneath the PPC were recorded throughout tests. Additionally, parameters of heat balance were estimated. Wearing a PPC did not cause a significant increase in the subjects' physiological response. The gastrointestinal temperature increment, the relative humidity of the microclimate underneath the PPC, the sweat residue in PPC, the sweat efficiency, the dry heat exchange and the total clothing insulation were significantly affected according to the PPC fabric composition. These results suggest that the PPC composition affect the moisture management. This might be taken into account to increase the wildland firefighters' protection in real situations, when they have to work close to the flames.

Impact of Different Personal Protective Clothing on Wildland Firefighters' Physiological Strain

Directory of Open Access Journals (Sweden)

Belén Carballo-Leyenda

2017-08-01

Full Text Available Wildfire firefighting is an extremely demanding occupation performed under hot environment. The use of personal protective clothing (PPC is needed to protect subjects from the thermal exposure. However, the additional use of PPC may increase the wildland firefighters' physiological strain, and consequently limit their performance. The aim of this study was to analyze the effect of four different PPC on the physiological strain of wildland firefighters under moderate conditions (30°C and 30% RH. Eight active and healthy wildland firefighters performed a submaximal walking test wearing a traditional short sports gear and 4 different PPC. The materials combination (viscose, Nomex, Kevlar, P-140 and fire resistant cotton used during the PPC manufacturing process was different. During all tests, to simulate a real scenario subjects wore a backpack pump (20 kg. Heart rate, respiratory gas exchange, gastrointestinal temperature, blood lactate concentration, perceived exertion and temperature and humidity underneath the PPC were recorded throughout tests. Additionally, parameters of heat balance were estimated. Wearing a PPC did not cause a significant increase in the subjects' physiological response. The gastrointestinal temperature increment, the relative humidity of the microclimate underneath the PPC, the sweat residue in PPC, the sweat efficiency, the dry heat exchange and the total clothing insulation were significantly affected according to the PPC fabric composition. These results suggest that the PPC composition affect the moisture management. This might be taken into account to increase the wildland firefighters' protection in real situations, when they have to work close to the flames.

Yield gap analysis of Chickpea under semi-arid conditions: A simulation study

Directory of Open Access Journals (Sweden)

seyed Reza Amiri Deh ahmadi

2016-05-01

Full Text Available Yield gap analysis provides an essential framework to prioritize research and policy efforts aimed at reducing yield constraints. To identify options for increasing chickpea yield, the SSM-chickpea model was parameterized and evaluated to analyze yield potentials, water limited yields and yield gaps for nine regions representing major chickpea-growing areas of Razavi Khorasan province. The average potential yield of chickpea for the locations was 2251 kg ha-1, while the water limited yield was 1026 kg ha-1 indicating a 54% reduction in yield due to adverse soil moisture conditions. Also, the average irrigated and rainfed actual yields were respectively 64% and 79% less than simulated potential and water limited yields. Maximum and minimum yield gap between potential yield and actual yield were observed in Quchan and Torbat-jam respectively. Generally, yield gap showed an increasing trend from the north (including Nishabur, Mashhad, Quchan and Daregaz regions to the south of the province (Torbat- Jam and Gonabad. In addition, yield gap between simulated water limited potential yield and rainfed actual yield were very low because both simulated water limiting potential and average rainfed actual yields were low in these regions. Yield gap analysis provides an essential framework to prioritize research and policy efforts aimed at reducing yield constraints. To identify options for increasing chickpea yield, the SSM-chickpea model was parameterized and evaluated to analyze yield potentials, water limited yields and yield gaps for nine regions representing major chickpea-growing areas of Razavi Khorasan province. The average potential yield of chickpea for the locations was 2251 kg ha-1, while the water limited yield was 1026 kg ha-1 indicating a 54% reduction in yield due to adverse soil moisture conditions. Also, the average irrigated and rainfed actual yields were respectively 64% and 79% less than simulated potential and water limited yields

Environmental Challenges and Physiological Solutions: Comparative Energetic Daily Rhythms of Field Mice Populations from Different Ecosystems

Science.gov (United States)

Scantlebury, Michael; Haim, Abraham

2012-01-01

Daily and seasonal variations in physiological characteristics of mammals can be considered adaptations to temporal habitat variables. Across different ecosystems, physiological adjustments are expected to be sensitive to different environmental signals such as changes in photoperiod, temperature or water and food availability; the relative importance of a particular signal being dependent on the ecosystem in question. Energy intake, oxygen consumption (VO2) and body temperature (Tb) daily rhythms were compared between two populations of the broad-toothed field mouse Apodemus mystacinus, one from a Mediterranean and another from a sub-Alpine ecosystem. Mice were acclimated to short-day (SD) ‘winter’ and long-day (LD) ‘summer’ photoperiods under different levels of salinity simulating osmotic challenges. Mediterranean mice had higher VO2 values than sub-Alpine mice. In addition, mice exposed to short days had higher VO2 values when given water with a high salinity compared with mice exposed to long days. By comparison, across both populations, increasing salinity resulted in a decreased Tb in SD- but not in LD-mice. Thus, SD-mice may conserve energy by decreasing Tb during (‘winter’) conditions which are expected to be cool, whereas LD-mice might do the opposite and maintain a higher Tb during (‘summer’) conditions which are expected to be warm. LD-mice behaved to reduce energy expenditure, which might be considered a useful trait during ‘summer’ conditions. Overall, increasing salinity was a clear signal for Mediterranean-mice with resultant effects on VO2 and Tb daily rhythms but had less of an effect on sub-Alpine mice, which were more responsive to changes in photoperiod. Results provide an insight into how different populations respond physiologically to various environmental challenges. PMID:23251469

Deriving appropriate boundary conditions, and accelerating position-jump simulations, of diffusion using non-local jumping

International Nuclear Information System (INIS)

Taylor, P R; Baker, R E; Yates, C A

2015-01-01

In this paper we explore lattice-based position-jump models of diffusion, and the implications of introducing non-local jumping; particles can jump to a range of nearby boxes rather than only to their nearest neighbours. We begin by deriving conditions for equivalence with traditional local jumping models in the continuum limit. We then generalize a previously postulated implementation of the Robin boundary condition for a non-local process of arbitrary maximum jump length, and present a novel implementation of flux boundary conditions, again generalized for a non-local process of arbitrary maximum jump length. In both these cases we validate our results using stochastic simulation. We then proceed to consider two variations on the basic diffusion model: a hybrid local/non-local scheme suitable for models involving sharp concentration gradients, and the implementation of biased jumping. In all cases we show that non-local jumping can deliver substantial time savings for stochastic simulations. (paper)

Spectrophotometric analysis of flavonoid-DNA binding interactions at physiological conditions

Science.gov (United States)

Janjua, Naveed Kausar; Siddiqa, Asima; Yaqub, Azra; Sabahat, Sana; Qureshi, Rumana; Haque, Sayed ul

2009-12-01

Mode of interactions of three flavonoids [morin (M), quercetin (Q), and rutin (R)] with chicken blood ds.DNA (ck.DNA) has been investigated spectrophotometrically at different temperatures including body temperature (310 K) and at two physiological pH values, i.e. 7.4 (human blood pH) and 4.7 (stomach pH). The binding constants, Kf, evaluated using Benesi-Hildebrand equation showed that the flavonoids bind effectively through intercalation at both pH values and body temperature. Quercetin, somehow, showed greater binding capabilities with DNA. The free energies of flavonoid-DNA complexes indicated the spontaneity of their binding. The order of binding constants of three flavonoids at both pH values were found to be Kf(Q) > Kf(R) > Kf(M) and at 310 K.

Physiological Plausibility and Boundary Conditions of Theories of Risk Sensitivity

DEFF Research Database (Denmark)

Marchiori, Davide; Elqayam, Shira

2012-01-01

dilatation, which in turn positively correlates with a risk aversion behavior. They hypothesize that participants’ attention is increased in decision problems involving losses, which trigger an innate prudent behavior in situations entailing danger and/or hazard. Interestingly, Y&T find that the nature...... of attention is not selective, i.e., when losses are present, participants are shown to devote more attention to the task as a whole rather than to the single negative outcomes, in contrast to Prospect Theory's loss aversion....... and physiological underpinnings of one of the central topics in judgment and decision-making (JDM) research – choice behavior in decisions from experience. Y&T successfully contributes to this goal by demonstrating a novel effect that losses increase experimental participants’ arousal as measured by pupil...

Evaluation Physiological Characteristics and Grain Yield Canola Cultivars under end Seasonal Drought Stress in Weather Condition of Ahvaz

Directory of Open Access Journals (Sweden)

A Seyed Ahmadi

2015-07-01

Full Text Available To evaluate canola cultivars response to physiological characteristics and grain yield end seasonal drought stress in weather condition of Ahvaz, farm experiments were done at research farm of Khuzestan agriculture and natural resources center. During 2007-2008 and 2008-2009 crop years. Farm test comprised drought stress was done as split plot form with randomize complete block design with four replication, treatments consist of drought stress (main factor including 50, 60 and 70 percent of water use content, which was applied from early heading stage until physiological maturity, and three spring canola cultivar including Shirali, Hayola 401 and R.G.S. were considered as sub plots. Measurements include biological yield, grain yield, harvesting index, number of pod per plant 1000 grain weight, number of grain in pod, plant height, and stem diameter, oil and protein percentage. Results showed that drought stress reduced significantly grain yield, biological yield, harvest index and the average of reduction of them during 2 years for per unit reduce moisture from 50% to 70% were 2, 1.35, and 0.81 percent, respectively. During two years, 1000 grain weight, number of pods per plant and number of grain per pod reduced 27, 36 and 20 percent, respectively. Terminal Drought stress reduced significantly plant height, stem diameter, stem number per plant and pod length, this reduced were 12, 46, 36 and 14 percent, respectively. Stem diameter, and stem number per plant reduced more than other characteristics. In this study oil grain decreased 12 % and protein grain increased 18.5% but oil and protein yield decreased 44.9% and 27.1% respectively..Finally, in weather condition of Khuzestan, terminal drought stress on February and March in which has simultaneous with early flowering stage and filling seed, significantly, reduced yield and compounded yield and affects on stem growth and qualities oil and protein negatively. Therefore, with irrigation

Conceptual design of wearpack with physiology detector feature based on wearable instrumentation

Science.gov (United States)

Sukirman, Melani; Laksono, Pringgo Widyo; Priadythama, Ilham; Susmartini, Susy; Suhardi, Bambang

2017-11-01

Every company in Indonesia is responsible for their worker health and safety condition as mentioned in UU No I year 1970. In manufacturing industries, there are many manual tasks dealing with high work load and risk, so that they require excellent concentration and physical condition. There is no ideal way to guarantee worker safety without a real time physiological monitoring. This paper reports our ongoing study in conceptual design development of worker's clothing which is equipped with a wearable instrumentation system. The system is designed to detect and measure body temperature and pulse in real time. Some electrical components such as, LCD (liquid crystal display), LEDs (light emitting diode), batteries, and physiological sensors were assembled. All components are controlled by a wearable on board controller. LEDs is used as alert which can indicate abnormal physical conditions. The LCD was added to provide more detail information. TMP 36 and XD-58C were selected as the physiological sensors. Finally, an Arduino Lilypad was chosen for the controller. This instrumentation system was verified by accurately detected and inform physiological condition of 3 subjects. Further we are going to attach the system to a worker's clothing which was specifically designed to simplify and comfortable usage.

Large eddy simulation of cooling flows in underground subway station according to different PSD operating conditions

Energy Technology Data Exchange (ETDEWEB)

Jang, Yong Jun; Kim, Jin Ho; Park, Sung Huk; Koo, Dong Hoe [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2015-11-15

Large eddy simulation (LES) method is applied to systematically investigate the cooling fluid flow and the temperature distribution under the operating of air conditioning in the deeply underground subway station. The Shin-Gum-Ho subway station in Seoul which is the 8{sup th} floor and 43.6 m deep is selected for this analysis. The entire station is covered for simulation. The ventilation mode for air conditioning is kept as ordinary state. Different operating conditions for Platform screen door (PSD) are applied. First one is PSD is completely close and second one is PSD is regularly open and close which imitate the actual circumstances in the platform. The ventilation diffusers are modeled as 95 square shapes in the lobby and 222 squares in the platform. The temperature variations and flow behaviors are numerically simulated after operating of air conditioning for the whole station and the calculated results are compared with experimental data. LES method solves the momentum and thermal equations. Werner-Wengle wall law is applied to viscous sub layers for near wall resolution. The total grid numbers are 7.5 million and the whole domain is divided to 22 blocks. Multi blocks are computed in parallel using MPI. The results show the temperature difference in the platform between PSD-close and PSD-regularly open and close cases is 3-4 .deg. C.

Large eddy simulation of cooling flows in underground subway station according to different PSD operating conditions

International Nuclear Information System (INIS)

Jang, Yong Jun; Kim, Jin Ho; Park, Sung Huk; Koo, Dong Hoe

2015-01-01

Large eddy simulation (LES) method is applied to systematically investigate the cooling fluid flow and the temperature distribution under the operating of air conditioning in the deeply underground subway station. The Shin-Gum-Ho subway station in Seoul which is the 8"t"h floor and 43.6 m deep is selected for this analysis. The entire station is covered for simulation. The ventilation mode for air conditioning is kept as ordinary state. Different operating conditions for Platform screen door (PSD) are applied. First one is PSD is completely close and second one is PSD is regularly open and close which imitate the actual circumstances in the platform. The ventilation diffusers are modeled as 95 square shapes in the lobby and 222 squares in the platform. The temperature variations and flow behaviors are numerically simulated after operating of air conditioning for the whole station and the calculated results are compared with experimental data. LES method solves the momentum and thermal equations. Werner-Wengle wall law is applied to viscous sub layers for near wall resolution. The total grid numbers are 7.5 million and the whole domain is divided to 22 blocks. Multi blocks are computed in parallel using MPI. The results show the temperature difference in the platform between PSD-close and PSD-regularly open and close cases is 3-4 .deg. C