Two phases of aging separated by the Smurf transition as a public path to death.

PubMed

Dambroise, E; Monnier, L; Ruisheng, L; Aguilaniu, H; Joly, J-S; Tricoire, H; Rera, M

2016-03-22

Aging's most obvious characteristic is the time dependent increase of an individual's probability to die. This lifelong process is accompanied by a large number of molecular and physiological changes. Although numerous genes involved in aging have been identified in the past decades its leading factors have yet to be determined. To identify the very processes driving aging we have developed in the past years an assay to identify physiologically old individuals in a synchronized population of Drosophila melanogaster. Those individuals show an age-dependent increase of intestinal permeability followed by a high risk of death. Here we show that this physiological marker of aging is conserved in 3 invertebrate species Drosophila mojavensis, Drosophila virilis, Caenorhabditis elegans as well as in 1 vertebrate species Danio rerio. Our findings suggest that intestinal barrier dysfunction may be an important event in the aging process conserved across a broad range of species, thus raising the possibility that it may also be the case in Homo sapiens.

Intestinal mucosal atrophy and adaptation

PubMed Central

Shaw, Darcy; Gohil, Kartik; Basson, Marc D

2012-01-01

Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes. PMID:23197881

Deep sequencing reveals complex mechanisms of diapause preparation in the invasive mosquito, Aedes albopictus.

PubMed

Poelchau, Monica F; Reynolds, Julie A; Elsik, Christine G; Denlinger, David L; Armbruster, Peter A

2013-05-22

Seasonal environments present fundamental physiological challenges to a wide range of insects. Many temperate insects surmount the exigencies of winter by undergoing photoperiodic diapause, in which photoperiod provides a token cue that initiates an alternative developmental programme leading to dormancy. Pre-diapause is a crucial preparatory phase of this process, preceding developmental arrest. However, the regulatory and physiological mechanisms of diapause preparation are largely unknown. Using high-throughput gene expression profiling in the Asian tiger mosquito, Aedes albopictus, we reveal major shifts in endocrine signalling, cell proliferation, metabolism, energy production and cellular structure across pre-diapause development. While some hallmarks of diapause, such as insulin signalling and stress response, were not important at the transcriptional level, two genes, Pepck and PCNA, appear to show diapause-induced transcriptional changes across insect taxa. These processes demonstrate physiological commonalities between Ae. albopictus pre-diapause and diapause strategies across insects, and support the idea of a genetic 'toolkit' for diapause. Observations of gene expression trends from a comparative developmental perspective suggest that individual physiological processes are delayed against a background of a fixed morphological ontogeny. Our results demonstrate how deep sequencing can provide new insights into elusive molecular bases of complex ecological adaptations.

'Multimorbidity' as the manifestation of network disturbances.

PubMed

Sturmberg, Joachim P; Bennett, Jeanette M; Martin, Carmel M; Picard, Martin

2017-02-01

We argue that 'multimorbidity' is the manifestation of interconnected physiological network processes within an individual in his or her socio-cultural environment. Networks include genomic, metabolomic, proteomic, neuroendocrine, immune and mitochondrial bioenergetic elements, as well as social, environmental and health care networks. Stress systems and other physiological mechanisms create feedback loops that integrate and regulate internal networks within the individual. Minor (e.g. daily hassles) and major (e.g. trauma) stressful life experiences perturb internal and social networks resulting in physiological instability with changes ranging from improved resilience to unhealthy adaptation and 'clinical disease'. Understanding 'multimorbidity' as a complex adaptive systems response to biobehavioural and socio-environmental networks is essential. Thus, designing integrative care delivery approaches that more adequately address the underlying disease processes as the manifestation of a state of physiological dysregulation is essential. This framework can shape care delivery approaches to meet the individual's care needs in the context of his or her underlying illness experience. It recognizes 'multimorbidity' and its symptoms as the end product of complex physiological processes, namely, stress activation and mitochondrial energetics, and suggests new opportunities for treatment and prevention. The future of 'multimorbidity' management might become much more discerning by combining the balancing of physiological dysregulation with targeted personalized biotechnology interventions such as small molecule therapeutics targeting specific cellular components of the stress response, with community-embedded interventions that involve addressing psycho-socio-cultural impediments that would aim to strengthen personal/social resilience and enhance social capital. © 2016 John Wiley & Sons, Ltd.

Perioperative abstinence from cigarettes: physiologic and clinical consequences.

PubMed

Warner, David O

2006-02-01

Chronic exposure to cigarette smoke produces profound changes in physiology that may alter responses to perioperative interventions and contribute to perioperative morbidity. Because of smoke-free policies in healthcare facilities, all smokers undergoing surgery are abstinent from cigarettes for at least some period of time so that all are in various stages of recovery from the effects of smoke. Understanding this recovery process will help perioperative physicians better treat these patients. This review examines current knowledge regarding how both short-term (duration ranging from hours to weeks) and long-term smoking cessation affects selected physiology and pathophysiology of particular relevance to perioperative outcomes and how these changes affect perioperative risk. It will also consider current evidence regarding how nicotine replacement therapy, a valuable adjunct to help patients maintain abstinence, may affect perioperative physiology.

Exploring the Limits of Cell Adhesion under Shear Stress within Physiological Conditions and beyond on a Chip.

PubMed

Stamp, Melanie E M; Jötten, Anna M; Kudella, Patrick W; Breyer, Dominik; Strobl, Florian G; Geislinger, Thomas M; Wixforth, Achim; Westerhausen, Christoph

2016-10-21

Cell adhesion processes are of ubiquitous importance for biomedical applications such as optimization of implant materials. Here, not only physiological conditions such as temperature or pH, but also topographical structures play crucial roles, as inflammatory reactions after surgery can diminish osseointegration. In this study, we systematically investigate cell adhesion under static, dynamic and physiologically relevant conditions employing a lab-on-a-chip system. We screen adhesion of the bone osteosarcoma cell line SaOs-2 on a titanium implant material for pH and temperature values in the physiological range and beyond, to explore the limits of cell adhesion, e.g., for feverish and acidic conditions. A detailed study of different surface roughness R q gives insight into the correlation between the cells' abilities to adhere and withstand shear flow and the topography of the substrates, finding a local optimum at R q = 22 nm. We use shear stress induced by acoustic streaming to determine a measure for the ability of cell adhesion under an external force for various conditions. We find an optimum of cell adhesion for T = 37 °C and pH = 7.4 with decreasing cell adhesion outside the physiological range, especially for high T and low pH. We find constant detachment rates in the physiological regime, but this behavior tends to collapse at the limits of 41 °C and pH 4.

Use of a latitudinal gradient in bald cypress (Taxodium distichum) production to examine physiological controls of biotic boundaries and potential responses to environment change

USGS Publications Warehouse

Middleton, B.A.; McKee, K.L.

2004-01-01

Aim: Predictions of vegetation change with global warming require models that accurately reflect physiological processes underlying growth limitations and species distributions. However, information about environmental controls on physiology and consequent effects on species boundaries and ecosystem functions such as production is limited, especially for forested wetlands that are potentially important carbon sinks. Location: The bald cypress (Taxodium distichum) region of the south-eastern United States was studied to examine how production of an important forested wetland varies with latitude and temperature as well as local hydrology. Methods: We used published data to analyse litter production across a latitudinal gradient from 26.2 to 37.8?? N to determine how bald cypress swamps might respond to alternate climate conditions and what changes might occur throughout the distributional range. Results: Litterfall rates followed a bell shaped curve, indicating that production was more limited at the distributional boundaries (c. 225 g/m2 year-1) compared to the mid-range (795-1126 g/m2 year-1). This pattern suggests that conditions are sub-optimal near both boundaries and that the absence of populations outside this latitudinal range may be largely due to physiological constraints on the carbon balance of dominant species. While dispersal limitations cannot be totally discounted, competition with other wetland types at the extremes of the range does not seem likely to be important because the relative basal area of bald cypress does not decrease near the edges of the range. Impaired hydrology depressed production across the entire range, but more in the south than the north. Main conclusions: Our findings suggest that (1) physiological limitations constrain biotic boundaries of bald cypress swamps; (2) future changes in global temperature would affect litter production in a nonlinear manner across the distributional range; (3) local changes in hydrology may interact with climate to further reduce litter production, particularly at lower latitudes; and (4) southernmost forests could be extirpated if environmental conditions compromise carbon balance and water-use efficiency of trees. ?? 2004 Blackwell Publishing Ltd.

Physiological and behavioural responses to weaning conflict in free-ranging primate infants

PubMed Central

Mandalaywala, Tara M.; Higham, James P.; Heistermann, Michael; Parker, Karen J.; Maestripieri, Dario

2014-01-01

Weaning, characterized by maternal reduction of resources, is both psychologically and energetically stressful to mammalian offspring. Despite the importance of physiology in this process, previous studies have reported only indirect measures of weaning stress from infants, because of the difficulties of collecting physiological measures from free-ranging mammalian infants. Here we present some of the first data on the relationship between weaning and energetic and psychological stress in infant mammals. We collected data on 47 free-ranging rhesus macaque infants on Cayo Santiago, Puerto Rico, showing that faecal glucocorticoid metabolite (fGCM) concentrations were directly related to the frequency of maternal rejection, with fGCM concentrations increasing as rates of rejection increased. Infants with higher fGCM concentrations also engaged in higher rates of mother following, and mother following was associated with increased time on the nipple, suggesting that infants that experienced greater weaning-related stress increased their efforts to maintain proximity and contact with their mothers. Infants experiencing more frequent rejection uttered more distress vocalizations when being rejected; however, there was no relationship between rates of distress vocalizations and fGCM concentrations, suggesting a disassociation between behavioural and physiological stress responses to weaning. Elevated glucocorticoid concentrations during weaning may function to mobilize energy reserves and prepare the infant for continued maternal rejection and shortage of energetic resources. PMID:25431499

Phenotypic Variability in the Coccolithophore Emiliania huxleyi.

PubMed

Blanco-Ameijeiras, Sonia; Lebrato, Mario; Stoll, Heather M; Iglesias-Rodriguez, Debora; Müller, Marius N; Méndez-Vicente, Ana; Oschlies, Andreas

2016-01-01

Coccolithophores are a vital part of oceanic phytoplankton assemblages that produce organic matter and calcium carbonate (CaCO3) containing traces of other elements (i.e. Sr and Mg). Their associated carbon export from the euphotic zone to the oceans' interior plays a crucial role in CO2 feedback mechanisms and biogeochemical cycles. The coccolithophore Emiliania huxleyi has been widely studied as a model organism to understand physiological, biogeochemical, and ecological processes in marine sciences. Here, we show the inter-strain variability in physiological and biogeochemical traits in 13 strains of E. huxleyi from various biogeographical provinces obtained from culture collections commonly used in the literature. Our results demonstrate that inter-strain genetic variability has greater potential to induce larger phenotypic differences than the phenotypic plasticity of single strains cultured under a broad range of variable environmental conditions. The range of variation found in physiological parameters and calcite Sr:Ca highlights the need to reconsider phenotypic variability in paleoproxy calibrations and model parameterizations to adequately translate findings from single strain laboratory experiments to the real ocean.

Validation of an in vitro digestive system for studying macronutrient decomposition in humans.

PubMed

Kopf-Bolanz, Katrin A; Schwander, Flurina; Gijs, Martin; Vergères, Guy; Portmann, Reto; Egger, Lotti

2012-02-01

The digestive process transforms nutrients and bioactive compounds contained in food to physiologically active compounds. In vitro digestion systems have proven to be powerful tools for understanding and monitoring the complex transformation processes that take place during digestion. Moreover, the investigation of the physiological effects of certain nutrients demands an in vitro digestive process that is close to human physiology. In this study, human digestion was simulated with a 3-step in vitro process that was validated in depth by choosing pasteurized milk as an example of a complex food matrix. The evolution and decomposition of the macronutrients was followed over the entire digestive process to the level of intestinal enterocyte action, using protein and peptide analysis by SDS-PAGE, reversed-phase HPLC, size exclusion HPLC, and liquid chromatography-MS. The mean peptide size after in vitro digestion of pasteurized milk was 5-6 amino acids (AA). Interestingly, mostly essential AA (93.6%) were released during in vitro milk digestion, a significantly different relative distribution compared to the total essential AA concentration of bovine milk (44.5%). All TG were degraded to FFA and monoacylglycerols. Herein, we present a human in vitro digestion model validated for its ability to degrade the macronutrients of dairy products comparable to physiological ranges. It is suited to be used in combination with a human intestinal cell culture system, allowing ex vivo bioavailability measurements and assessment of the bioactive properties of food components.

A luminescent Lanthanide-free MOF nanohybrid for highly sensitive ratiometric temperature sensing in physiological range.

PubMed

Zhou, You; Zhang, Denan; Zeng, Jin; Gan, Ning; Cuan, Jing

2018-05-01

Luminescent MOF materials with tunable emissions and energy/charge transfer processes have been extensively explored as ratiometric temperature sensors. However, most of the ratiometric MOF thermometers reported thus far are based on the MOFs containing photoactive lanthanides, which are potentially facing cost issue and serious supply shortage. Here, we present a ratiometric luminescent thermometer based on a dual-emitting lanthanide-free MOF hybrid, which is developed by encapsulation of a fluorescent dye into a robust nanocrystalline zirconium-based MOF through a one-pot synthesis approach. The structure and morphology of the hybrid product was characterized by Powder X-ray diffraction (PXRD), N 2 adsorption-desorption measurement and Scanning electron microscopy (SEM). The pore confinement effect well isolates the guest dye molecules and therefore suppresses the nonradiative energy transfer process between dye molecules. The incorporated dye emission is mainly sensitized by the organic linkers within MOF through fluorescence resonance energy transfer. The ratiometric luminescence of the MOF hybrid shows a significant response to temperature due to the thermal-related back energy transfer process from dye molecules and organic linkers, thus can be exploited for self-calibrated temperature sensing. The maximum thermometric sensitivity is 1.19% °C -1 in the physiological temperature range, which is among the highest for the ratiomtric MOF thermometers that operating in 25-45°C. The temperature resolution is better than 0.1°C over the entire operative range (20-60°C). By integrating the advantages of excellent stability, nanoscale nature, and high sensitivity and precision in the physiological temperature range, this dye@MOF hybrid might have potential application in biomedical diagnosis. What' more, this work has expanded the possibility of non-lanthanide luminescent MOF materials for the development of ratiometric temperature sensors. Copyright © 2018 Elsevier B.V. All rights reserved.

FACTORS AFFECTING THINKING AND COMPREHENSION SKILLS.

ERIC Educational Resources Information Center

ABRAMS, JULES C.

INTELLECTUAL, EDUCATIONAL, NEUROLOGICAL, PHYSIOLOGICAL, PSYCHOLOGICAL, AND SOCIOLOGICAL FACTORS IN VARIOUS PATTERNS OF INTERRELATIONSHIPS INFLUENCE THE THINKING PROCESS. INDIVIDUALS DIFFER IN THE CONCEPTS THEY HOLD AND IN THEIR USE OF THESE CONCEPTS BECAUSE OF VARIATIONS IN INTELLIGENCE AND BACKGROUND OF EXPERIENCE. THE RANGE AND LEVEL OF CONCEPTS…

Development of sensitive holographic devices for physiological metal ion detection

NASA Astrophysics Data System (ADS)

Sabad-e.-Gul; Martin, Suzanne; Cassidy, John; Naydenova, Izabela

2017-08-01

The development of selective alkali metal ions sensors in particular is a subject of significant interest. In this respect, the level of blood electrolytes, particularly H+, Na+, K+ and Cl- , is widely used to monitor aberrant physiologies associated with pulmonary emphysema, acute and chronic renal failure, heart failure, diabetes. The sensors reported in this paper are created by holographic recording of surface relief structures in a self-processing photopolymer material. The structures are functionalized by ionophores dibenzo-18-crown-6 (DC) and tetraethyl 4-tert-butylcalix[4]arene (TBC) in plasticised polyvinyl chloride (PVC) matrix. Interrogation of these structures by light allows indirect measurements of chemical analytes' concentration in real time. We present results on the optimisation and testing of the holographic sensor. A self-processing acrylamide-based photopolymer was used to fabricate the required photonic structures. The performance of the sensors for detection of K+ and Na+ was investigated. It was observed that the functionalisation with DC provides a selective response of the devices to K+ over Na+ and TBC coated surface structures are selectively sensitive to Na+. The sensor responds to Na+ within the physiological ranges. Normal levels of Na+ and K+ in human serum lie within the ranges 135-148mM and 3.5-5.3 mM respectively.

Coupled soil respiration and transpiration dynamics from tree-scale to catchment scale in dry Rocky Mountain pine forests and the role of snowpack

NASA Astrophysics Data System (ADS)

Berryman, E.; Barnard, H. R.; Brooks, P. D.; Adams, H.; Burns, M. A.; Wilson, W.; Stielstra, C. M.

2013-12-01

A current ecohydrological challenge is quantifying the exact nature of carbon (C) and water couplings across landscapes. An emerging framework of understanding places plant physiological processes as a central control over soil respiration, the largest source of CO2 to the atmosphere. In dry montane forests, spatial and temporal variability in forest physiological processes are governed by hydrological patterns. Critical feedbacks involving respiration, moisture supply and tree physiology are poorly understood and must be quantified at the landscape level to better predict carbon cycle implications of regional drought under future climate change. We present data from an experiment designed to capture landscape variability in key coupled hydrological and C processes in forests of Colorado's Front Range. Sites encompass three catchments within the Boulder Creek watershed, range from 1480 m to 3021 m above sea level and are co-located with the DOE Niwot Ridge Ameriflux site and the Boulder Creek Critical Zone Observatory. Key hydrological measurements (soil moisture, transpiration) are coupled with soil respiration measurements within each catchment at different landscape positions. This three-dimensional study design also allows for the examination of the role of water subsidies from uplands to lowlands in controlling respiration. Initial findings from 2012 reveal a moisture threshold response of the sensitivity of soil respiration to temperature. This threshold may derive from tree physiological responses to variation in moisture availability, which in turn is controlled by the persistence of snowpack. Using data collected in 2013, first, we determine whether respiration moisture thresholds represent triggers for transpiration at the individual tree level. Next, using stable isotope ratios of soil respiration and xylem and soil water, we compare the depths of respiration to depths of water uptake to assign tree vs. understory sources of respiration. This will help determine whether tree root-zone respiration exhibits a similar moisture threshold. Lastly, we examine whether moisture thresholds to temperature sensitivity are consistent across a range of snowpack persistence. Findings are compared to data collected from sites in Arizona and New Mexico to better establish the role of winter precipitation in governing growing season respiration rates. The outcome of this study will contribute to a better understanding of linkages among water, tree physiology, and soil respiration with the ultimate goal of scaling plot-level respiration fluxes to entire catchments.

Computational Model of Adrenal Steroidogenesis to Predict Biochemical Response to Endocrine Disruptors

EPA Science Inventory

Steroids, which have an important role in a wide range of physiological processes, are synthesized primarily in the gonads and adrenal glands through a series of enzyme mediated reactions. The activity of steroidogenic enzymes can be altered by various endocrine disrupters (ED), ...

The TRP channel superfamily: insights into how structure, protein-lipid interactions and localization influence function.

PubMed

Reaves, B J; Wolstenholme, A J

2007-02-01

TRP (transient receptor potential) cationic channels are key molecules that are involved in a variety of diverse biological processes ranging from fertility to osmosensation and nociception. Increasing our knowledge of these channels will help us to understand a range of physiological and pathogenic processes, as well as highlighting potential therapeutic drug targets. The founding members of the TRP family, Drosophila TRP and TRPL (TRP-like) proteins, were identified within the last two decades and there has been a subsequent explosion in the number and type of TRP channel described. Although information is accumulating as to the function of some of the TRP channels, the activation and inactivation mechanisms, structure, and interacting proteins of many, if not most, are awaiting elucidation. The Cell and Molecular Biology of TRP Channels Meeting held at the University of Bath included speakers working on a number of the different subfamilies of TRP channels and provided a basis for highlighting both similarities and differences between these groups. As the TRP channels mediate diverse functions, this meeting also brought together an audience with wide-ranging research interests, including biochemistry, cell biology, physiology and neuroscience, and inspired lively discussion on the issues reviewed herein.

Beauty and the brain: culture, history and individual differences in aesthetic appreciation.

PubMed

Jacobsen, Thomas

2010-02-01

Human aesthetic processing entails the sensation-based evaluation of an entity with respect to concepts like beauty, harmony or well-formedness. Aesthetic appreciation has many determinants ranging from evolutionary, anatomical or physiological constraints to influences of culture, history and individual differences. There are a vast number of dynamically configured neural networks underlying these multifaceted processes of aesthetic appreciation. In the current challenge of successfully bridging art and science, aesthetics and neuroanatomy, the neuro-cognitive psychology of aesthetics can approach this complex topic using a framework that postulates several perspectives, which are not mutually exclusive. In this empirical approach, objective physiological data from event-related brain potentials and functional magnetic resonance imaging are combined with subjective, individual self-reports.

Beauty and the brain: culture, history and individual differences in aesthetic appreciation

PubMed Central

Jacobsen, Thomas

2010-01-01

Human aesthetic processing entails the sensation-based evaluation of an entity with respect to concepts like beauty, harmony or well-formedness. Aesthetic appreciation has many determinants ranging from evolutionary, anatomical or physiological constraints to influences of culture, history and individual differences. There are a vast number of dynamically configured neural networks underlying these multifaceted processes of aesthetic appreciation. In the current challenge of successfully bridging art and science, aesthetics and neuroanatomy, the neuro-cognitive psychology of aesthetics can approach this complex topic using a framework that postulates several perspectives, which are not mutually exclusive. In this empirical approach, objective physiological data from event-related brain potentials and functional magnetic resonance imaging are combined with subjective, individual self-reports. PMID:19929909

Syllabic (~2-5 Hz) and fluctuation (~1-10 Hz) ranges in speech and auditory processing

PubMed Central

Edwards, Erik; Chang, Edward F.

2013-01-01

Given recent interest in syllabic rates (~2-5 Hz) for speech processing, we review the perception of “fluctuation” range (~1-10 Hz) modulations during listening to speech and technical auditory stimuli (AM and FM tones and noises, and ripple sounds). We find evidence that the temporal modulation transfer function (TMTF) of human auditory perception is not simply low-pass in nature, but rather exhibits a peak in sensitivity in the syllabic range (~2-5 Hz). We also address human and animal neurophysiological evidence, and argue that this bandpass tuning arises at the thalamocortical level and is more associated with non-primary regions than primary regions of cortex. The bandpass rather than low-pass TMTF has implications for modeling auditory central physiology and speech processing: this implicates temporal contrast rather than simple temporal integration, with contrast enhancement for dynamic stimuli in the fluctuation range. PMID:24035819

Drought stress limits the geographic ranges of two tree species via different physiological mechanisms.

PubMed

Anderegg, Leander D L; HilleRisLambers, Janneke

2016-03-01

Range shifts are among the most ubiquitous ecological responses to anthropogenic climate change and have large consequences for ecosystems. Unfortunately, the ecophysiological forces that constrain range boundaries are poorly understood, making it difficult to mechanistically project range shifts. To explore the physiological mechanisms by which drought stress controls dry range boundaries in trees, we quantified elevational variation in drought tolerance and in drought avoidance-related functional traits of a widespread gymnosperm (ponderosa pine - Pinus ponderosa) and angiosperm (trembling aspen - Populus tremuloides) tree species in the southwestern USA. Specifically, we quantified tree-to-tree variation in growth, water stress (predawn and midday xylem tension), drought avoidance traits (branch conductivity, leaf/needle size, tree height, leaf area-to-sapwood area ratio), and drought tolerance traits (xylem resistance to embolism, hydraulic safety margin, wood density) at the range margins and range center of each species. Although water stress increased and growth declined strongly at lower range margins of both species, ponderosa pine and aspen showed contrasting patterns of clinal trait variation. Trembling aspen increased its drought tolerance at its dry range edge by growing stronger but more carbon dense branch and leaf tissues, implying an increased cost of growth at its range boundary. By contrast, ponderosa pine showed little elevational variation in drought-related traits but avoided drought stress at low elevations by limiting transpiration through stomatal closure, such that its dry range boundary is associated with limited carbon assimilation even in average climatic conditions. Thus, the same climatic factor (drought) may drive range boundaries through different physiological mechanisms - a result that has important implications for process-based modeling approaches to tree biogeography. Further, we show that comparing intraspecific patterns of trait variation across ranges, something rarely done in a range-limit context, helps elucidate a mechanistic understanding of range constraints. © 2015 John Wiley & Sons Ltd.

[THE STATUS OF CERTAIN PHYSIOLOGICAL ADRENERGIC RESPONSES IN ALBINO RATS DURING DEVELOPMENT OF EXPERIMENTAL HYPERTHYROIDISM].

PubMed

Osman, Nizar Salim; Ismail, Mohsen

2015-01-01

In this paper we investigated the effects of thyroid hormones on the expression of physiological reactions during adrenergic stimulation (20 min at a dose of 2.0 mg x kg(-1) x min(-1)) during the development of experimental hyperthyroidism. Rats were divided into two groups. The animals in Group 1 were injected woth triiodothyronine. The duration of injection ranged from 1 to 12 days. Consequently, 12 subgroups were formed. The second group was the control group. It is shown that in the process of development of experimental hyperthyroidism all physiological responses vary in accordance with the law, which can be described by a parabola of general form with the value of the degree in the equation equal to three.

Understanding diffusion theory and Fick's law through food and cooking.

PubMed

Zhou, Larissa; Nyberg, Kendra; Rowat, Amy C

2015-09-01

Diffusion is critical to physiological processes ranging from gas exchange across alveoli to transport within individual cells. In the classroom, however, it can be challenging to convey the concept of diffusion on the microscopic scale. In this article, we present a series of three exercises that use food and cooking to illustrate diffusion theory and Fick's first law. These exercises are part of a 10-wk undergraduate course that uses food and cooking to teach fundamental concepts in physiology and biophysics to students, including nonscience majors. Consistent demonstration of practical applications in a classroom setting has the potential to fundamentally change how students view the role of science in their lives (15). Copyright © 2015 The American Physiological Society.

When galectins recognize glycans: from biochemistry to physiology and back again.

PubMed

Di Lella, Santiago; Sundblad, Victoria; Cerliani, Juan P; Guardia, Carlos M; Estrin, Dario A; Vasta, Gerardo R; Rabinovich, Gabriel A

2011-09-20

In the past decade, increasing efforts have been devoted to the study of galectins, a family of evolutionarily conserved glycan-binding proteins with multifunctional properties. Galectins function, either intracellularly or extracellularly, as key biological mediators capable of monitoring changes occurring on the cell surface during fundamental biological processes such as cellular communication, inflammation, development, and differentiation. Their highly conserved structures, exquisite carbohydrate specificity, and ability to modulate a broad spectrum of biological processes have captivated a wide range of scientists from a wide spectrum of disciplines, including biochemistry, biophysics, cell biology, and physiology. However, in spite of enormous efforts to dissect the functions and properties of these glycan-binding proteins, limited information about how structural and biochemical aspects of these proteins can influence biological functions is available. In this review, we aim to integrate structural, biochemical, and functional aspects of this bewildering and ancient family of glycan-binding proteins and discuss their implications in physiologic and pathologic settings. © 2011 American Chemical Society

Nitric Oxide-Dependent Posttranslational Modification in Plants: An Update

PubMed Central

Astier, Jeremy; Lindermayr, Christian

2012-01-01

Nitric oxide (NO) has been demonstrated as an essential regulator of several physiological processes in plants. The understanding of the molecular mechanism underlying its critical role constitutes a major field of research. NO can exert its biological function through different ways, such as the modulation of gene expression, the mobilization of second messengers, or interplays with protein kinases. Besides this signaling events, NO can be responsible of the posttranslational modifications (PTM) of target proteins. Several modifications have been identified so far, whereas metal nitrosylation, the tyrosine nitration and the S-nitrosylation can be considered as the main ones. Recent data demonstrate that these PTM are involved in the control of a wide range of physiological processes in plants, such as the plant immune system. However, a great deal of effort is still necessary to pinpoint the role of each PTM in plant physiology. Taken together, these new advances in proteomic research provide a better comprehension of the role of NO in plant signaling. PMID:23203119

Scale-Free Neural and Physiological Dynamics in Naturalistic Stimuli Processing

PubMed Central

Lin, Amy

2016-01-01

Abstract Neural activity recorded at multiple spatiotemporal scales is dominated by arrhythmic fluctuations without a characteristic temporal periodicity. Such activity often exhibits a 1/f-type power spectrum, in which power falls off with increasing frequency following a power-law function: P(f)∝1/fβ, which is indicative of scale-free dynamics. Two extensively studied forms of scale-free neural dynamics in the human brain are slow cortical potentials (SCPs)—the low-frequency (<5 Hz) component of brain field potentials—and the amplitude fluctuations of α oscillations, both of which have been shown to carry important functional roles. In addition, scale-free dynamics characterize normal human physiology such as heartbeat dynamics. However, the exact relationships among these scale-free neural and physiological dynamics remain unclear. We recorded simultaneous magnetoencephalography and electrocardiography in healthy subjects in the resting state and while performing a discrimination task on scale-free dynamical auditory stimuli that followed different scale-free statistics. We observed that long-range temporal correlation (captured by the power-law exponent β) in SCPs positively correlated with that of heartbeat dynamics across time within an individual and negatively correlated with that of α-amplitude fluctuations across individuals. In addition, across individuals, long-range temporal correlation of both SCP and α-oscillation amplitude predicted subjects’ discrimination performance in the auditory task, albeit through antagonistic relationships. These findings reveal interrelations among different scale-free neural and physiological dynamics and initial evidence for the involvement of scale-free neural dynamics in the processing of natural stimuli, which often exhibit scale-free dynamics. PMID:27822495

Aberdeen polygons: computer displays of physiological profiles for intensive care.

PubMed

Green, C A; Logie, R H; Gilhooly, K J; Ross, D G; Ronald, A

1996-03-01

The clinician in an intensive therapy unit is presented regularly with a range of information about the current physiological state of the patients under care. This information typically comes from a variety of sources and in a variety of formats. A more integrated form of display incorporating several physiological parameters may be helpful therefore. Three experiments are reported that explored the potential use of analogue, polygon diagrams to display physiological data from patients undergoing intensive therapy. Experiment 1 demonstrated that information can be extracted readily from such diagrams comprising 8- or 10-sided polygons, but with an advantage for simpler polygons and for information displayed at the top of the diagram. Experiment 2 showed that colour coding removed these biases for simpler polygons and the top of the diagram, together with speeding the processing time. Experiment 3 used polygons displaying patterns of physiological data that were consistent with typical conditions observed in the intensive care unit. It was found that physicians can readily learn to recognize these patterns and to diagnose both the nature and severity of the patient's physiological state. These polygon diagrams appear to have some considerable potential for use in providing on-line summary information of a patient's physiological state.

Phenotypic plasticity in the range-margin population of the lycaenid butterfly Zizeeria maha

PubMed Central

2010-01-01

Background Many butterfly species have been experiencing the northward range expansion and physiological adaptation, probably due to climate warming. Here, we document an extraordinary field case of a species of lycaenid butterfly, Zizeeria maha, for which plastic phenotypes of wing color-patterns were revealed at the population level in the course of range expansion. Furthermore, we examined whether this outbreak of phenotypic changes was able to be reproduced in a laboratory. Results In the recently expanded northern range margins of this species, more than 10% of the Z. maha population exhibited characteristic color-pattern modifications on the ventral wings for three years. We physiologically reproduced similar phenotypes by an artificial cold-shock treatment of a normal southern population, and furthermore, we genetically reproduced a similar phenotype after selective breeding of a normal population for ten generations, demonstrating that the cold-shock-induced phenotype was heritable and partially assimilated genetically in the breeding line. Similar genetic process might have occurred in the previous and recent range-margin populations as well. Relatively minor modifications expressed in the tenth generation of the breeding line together with other data suggest a role of founder effect in this field case. Conclusions Our results support the notion that the outbreak of the modified phenotypes in the recent range-margin population was primed by the revelation of plastic phenotypes in response to temperature stress and by the subsequent genetic process in the previous range-margin population, followed by migration and temporal establishment of genetically unstable founders in the recent range margins. This case presents not only an evolutionary role of phenotypic plasticity in the field but also a novel evolutionary aspect of range expansion at the species level. PMID:20718993

Mechanistic species distribution modelling as a link between physiology and conservation.

PubMed

Evans, Tyler G; Diamond, Sarah E; Kelly, Morgan W

2015-01-01

Climate change conservation planning relies heavily on correlative species distribution models that estimate future areas of occupancy based on environmental conditions encountered in present-day ranges. The approach benefits from rapid assessment of vulnerability over a large number of organisms, but can have poor predictive power when transposed to novel environments and reveals little in the way of causal mechanisms that define changes in species distribution or abundance. Having conservation planning rely largely on this single approach also increases the risk of policy failure. Mechanistic models that are parameterized with physiological information are expected to be more robust when extrapolating distributions to future environmental conditions and can identify physiological processes that set range boundaries. Implementation of mechanistic species distribution models requires knowledge of how environmental change influences physiological performance, and because this information is currently restricted to a comparatively small number of well-studied organisms, use of mechanistic modelling in the context of climate change conservation is limited. In this review, we propose that the need to develop mechanistic models that incorporate physiological data presents an opportunity for physiologists to contribute more directly to climate change conservation and advance the field of conservation physiology. We begin by describing the prevalence of species distribution modelling in climate change conservation, highlighting the benefits and drawbacks of both mechanistic and correlative approaches. Next, we emphasize the need to expand mechanistic models and discuss potential metrics of physiological performance suitable for integration into mechanistic models. We conclude by summarizing other factors, such as the need to consider demography, limiting broader application of mechanistic models in climate change conservation. Ideally, modellers, physiologists and conservation practitioners would work collaboratively to build models, interpret results and consider conservation management options, and articulating this need here may help to stimulate collaboration.

Phenotypic Variability in the Coccolithophore Emiliania huxleyi

PubMed Central

Lebrato, Mario; Stoll, Heather M.; Iglesias-Rodriguez, Debora; Müller, Marius N.; Méndez-Vicente, Ana; Oschlies, Andreas

2016-01-01

Coccolithophores are a vital part of oceanic phytoplankton assemblages that produce organic matter and calcium carbonate (CaCO3) containing traces of other elements (i.e. Sr and Mg). Their associated carbon export from the euphotic zone to the oceans' interior plays a crucial role in CO2 feedback mechanisms and biogeochemical cycles. The coccolithophore Emiliania huxleyi has been widely studied as a model organism to understand physiological, biogeochemical, and ecological processes in marine sciences. Here, we show the inter-strain variability in physiological and biogeochemical traits in 13 strains of E. huxleyi from various biogeographical provinces obtained from culture collections commonly used in the literature. Our results demonstrate that inter-strain genetic variability has greater potential to induce larger phenotypic differences than the phenotypic plasticity of single strains cultured under a broad range of variable environmental conditions. The range of variation found in physiological parameters and calcite Sr:Ca highlights the need to reconsider phenotypic variability in paleoproxy calibrations and model parameterizations to adequately translate findings from single strain laboratory experiments to the real ocean. PMID:27348427

Conservation Physiology and Conservation Pathogens: White-Nose Syndrome and Integrative Biology for Host-Pathogen Systems.

PubMed

Willis, Craig K R

2015-10-01

Conservation physiology aims to apply an understanding of physiological mechanisms to management of imperiled species, populations, or ecosystems. One challenge for physiologists hoping to apply their expertise to conservation is connecting the mechanisms we study, often in the laboratory, with the vital rates of populations in the wild. There is growing appreciation that infectious pathogens can threaten populations and species, and represent an important issue for conservation. Conservation physiology has much to offer in terms of addressing the threat posed to some host species by infectious pathogens. At the same time, the well-developed theoretical framework of disease ecology could provide a model to help advance the application of physiology to a range of other conservation issues. Here, I use white-nose syndrome (WNS) in hibernating North American bats as an example of a conservation problem for which integrative physiological research has been a critical part of research and management. The response to WNS highlights the importance of a well-developed theoretical framework for the application of conservation physiology to a particular threat. I review what is known about physiological mechanisms associated with mortality from WNS and emphasize the value of combining a strong theoretical background with integrative physiological studies in order to connect physiological mechanisms with population processes and thereby maximize the potential benefits of conservation physiology. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Pioneer in Behavioral Pharmacology: A Tribute to Joseph V. Brady

ERIC Educational Resources Information Center

Barrett, James E.

2008-01-01

The contributions of Joseph V. Brady to behavioral pharmacology span more than 50 years and range from early studies using the Estes-Skinner ("conditioned emotional response") procedure to examine drug effects and various physiological processes in experimental animals to the implementation of mobile methadone treatment services and to small group…

Understanding Diffusion Theory and Fick's Law through Food and Cooking

ERIC Educational Resources Information Center

Zhou, Larissa; Nyberg, Kendra; Rowat, Amy C.

2015-01-01

Diffusion is critical to physiological processes ranging from gas exchange across alveoli to transport within individual cells. In the classroom, however, it can be challenging to convey the concept of diffusion on the microscopic scale. In this article, we present a series of three exercises that use food and cooking to illustrate diffusion…

Computational Steroidogenesis Model To Predict Biochemical Responses to Endocrine Active Chemicals: Model Development and Cross Validation

EPA Science Inventory

Steroids, which have an important role in a wide range of physiological processes, are synthesized primarily in the gonads and adrenal glands through a series of enzyme-mediated reactions. The activity of steroidogenic enzymes can be altered by a variety of endocrine active chem...

Effects of exercise on tumor physiology and metabolism.

PubMed

Pedersen, Line; Christensen, Jesper Frank; Hojman, Pernille

2015-01-01

Exercise is a potent regulator of a range of physiological processes in most tissues. Solid epidemiological data show that exercise training can reduce disease risk and mortality for several cancer diagnoses, suggesting that exercise training may directly regulate tumor physiology and metabolism. Here, we review the body of literature describing exercise intervention studies performed in rodent tumor models and elaborate on potential mechanistic effects of exercise on tumor physiology. Exercise has been shown to reduce tumor incidence, tumor multiplicity, and tumor growth across numerous different transplantable, chemically induced or genetic tumor models. We propose 4 emerging mechanistic effects of exercise, including (1) vascularization and blood perfusion, (2) immune function, (3) tumor metabolism, and (4) muscle-to-cancer cross-talk, and discuss these in details. In conclusion, exercise training has the potential to be a beneficial and integrated component of cancer management, but has yet to fully elucidate its potential. Understanding the mechanistic effects of exercise on tumor physiology is warranted. Insight into these mechanistic effects is emerging, but experimental intervention studies are still needed to verify the cause-effect relationship between these mechanisms and the control of tumor growth.

Wearable physiological sensors and real-time algorithms for detection of acute mountain sickness.

PubMed

Muza, Stephen R

2018-03-01

This is a minireview of potential wearable physiological sensors and algorithms (process and equations) for detection of acute mountain sickness (AMS). Given the emerging status of this effort, the focus of the review is on the current clinical assessment of AMS, known risk factors (environmental, demographic, and physiological), and current understanding of AMS pathophysiology. Studies that have examined a range of physiological variables to develop AMS prediction and/or detection algorithms are reviewed to provide insight and potential technological roadmaps for future development of real-time physiological sensors and algorithms to detect AMS. Given the lack of signs and nonspecific symptoms associated with AMS, development of wearable physiological sensors and embedded algorithms to predict in the near term or detect established AMS will be challenging. Prior work using [Formula: see text], HR, or HRv has not provided the sensitivity and specificity for useful application to predict or detect AMS. Rather than using spot checks as most prior studies have, wearable systems that continuously measure SpO 2 and HR are commercially available. Employing other statistical modeling approaches such as general linear and logistic mixed models or time series analysis to these continuously measured variables is the most promising approach for developing algorithms that are sensitive and specific for physiological prediction or detection of AMS.

The Role of Cholesterol Utilization in a Computational Adrenal Steroidogenesis Model to Improve Predictability of Biochemical Responses to Endocrine Active Chemicals

EPA Science Inventory

Steroids, which have an important role in a wide range of physiological processes, are synthesized primarily in the gonads and adrenal glands through a series of enzyme-mediated reactions. The activity of steroidogenic enzymes can be altered by a variety of endocrine active chem...

The Role of Oxysterols in a Computational Steroidogenesis Model of Human H295R Cells to Improve Predictability of Biochemical Responses to Endocrine Disruptors

EPA Science Inventory

Steroids, which have an important role in a wide range of physiological processes, are synthesized primarily in the gonads and adrenal glands through a series of enzyme mediated reactions. The activity of steroidogenic enzymes can be altered by a variety of endocrine disruptors (...

Never at rest: insights into the conformational dynamics of ion channels from cryo-electron microscopy.

PubMed

Lau, Carus; Hunter, Mark J; Stewart, Alastair; Perozo, Eduardo; Vandenberg, Jamie I

2018-04-01

The tightly regulated opening and closure of ion channels underlies the electrical signals that are vital for a wide range of physiological processes. Two decades ago the first atomic level view of ion channel structures led to a detailed understanding of ion selectivity and conduction. In recent years, spectacular developments in the field of cryo-electron microscopy have resulted in cryo-EM superseding crystallography as the technique of choice for determining near-atomic resolution structures of ion channels. Here, we will review the recent developments in cryo-EM and its specific application to the study of ion channel gating. We will highlight the advantages and disadvantages of the current technology and where the field is likely to head in the next few years. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

What Are the bona fide GSK3 Substrates?

PubMed

Sutherland, Calum

2011-01-01

Nearly 100 proteins are proposed to be substrates for GSK3, suggesting that this enzyme is a fundamental regulator of almost every process in the cell, in every tissue in the body. However, it is not certain how many of these proposed substrates are regulated by GSK3 in vivo. Clearly, the identification of the physiological functions of GSK3 will be greatly aided by the identification of its bona fide substrates, and the development of GSK3 as a therapeutic target will be highly influenced by this range of actions, hence the need to accurately establish true GSK3 substrates in cells. In this paper the evidence that proposed GSK3 substrates are likely to be physiological targets is assessed, highlighting the key cellular processes that could be modulated by GSK3 activity and inhibition.

Carbon dioxide-sensing in organisms and its implications for human disease

PubMed Central

Cummins, Eoin P.; Selfridge, Andrew C.; Sporn, Peter H.; Sznajder, Jacob I.; Taylor, Cormac T.

2013-01-01

The capacity of organisms to sense changes in the levels of internal and external gases and to respond accordingly is central to a range of physiologic and pathophysiologic processes. Carbon dioxide, a primary product of oxidative metabolism is one such gas that can be sensed by both prokaryotic and eukaryotic cells and in response to altered levels, elicit the activation of multiple adaptive pathways. The outcomes of activating CO2-sensitive pathways in various species include increased virulence of fungal and bacterial pathogens, prey-seeking behavior in insects as well as taste perception, lung function, and the control of immunity in mammals. In this review, we discuss what is known about the mechanisms underpinning CO2 sensing across a range of species and consider the implications of this for physiology, disease progression, and the possibility of developing new therapeutics for inflammatory and infectious disease. PMID:24045706

Physiology modulates social flexibility and collective behaviour in equids and other large ungulates.

PubMed

Gersick, Andrew S; Rubenstein, Daniel I

2017-08-19

Though morphologically very similar, equids across the extant species occupy ecological niches that are surprisingly non-overlapping. Occupancy of these distinct niches appears related to subtle physiological and behavioural adaptations which, in turn, correspond to significant differences in the social behaviours and emergent social systems characterizing the different species. Although instances of intraspecific behavioural variation in equids demonstrate that the same body plan can support a range of social structures, each of these morphologically similar species generally shows robust fidelity to its evolved social system. The pattern suggests a subtle relationship between physiological phenotypes and behavioural flexibility. While environmental conditions can vary widely within relatively short temporal or spatial scales, physiological changes and changes to the behaviours that regulate physiological processes, are constrained to longer cycles of adaptation. Physiology is then the limiting variable in the interaction between ecological variation and behavioural and socio-structural flexibility. Behavioural and socio-structural flexibility, in turn, will generate important feedbacks that will govern physiological function, thus creating a coupled web of interactions that can lead to changes in individual and collective behaviour. Longitudinal studies of equid and other large-bodied ungulate populations under environmental stress, such as those discussed here, may offer the best opportunities for researchers to examine, in real time, the interplay between individual behavioural plasticity, socio-structural flexibility, and the physiological and genetic changes that together produce adaptive change.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'. © 2017 The Author(s).

Responses to salinity stress in bivalves: Evidence of ontogenetic changes in energetic physiology on Cerastoderma edule.

PubMed

Peteiro, Laura G; Woodin, Sarah A; Wethey, David S; Costas-Costas, Damian; Martínez-Casal, Arantxa; Olabarria, Celia; Vázquez, Elsa

2018-05-29

Estuarine bivalves are especially susceptible to salinity fluctuations. Stage-specific sensibilities may influence the structure and spatial distribution of the populations. Here we investigate differences on the energetic strategy of thread drifters (3-4 mm) and sedentary settlers (9-10 mm) of Cerastoderma edule over a wide range of salinities. Several physiological indicators (clearance, respiration and excretion rates, O:N) were measured during acute (2 days) and acclimated responses (7 days of exposure) for both size classes. Our results revealed a common lethal limit for both developmental stages (Salinity 15) but a larger physiological plasticity of thread drifters than sedentary settlers. Acclimation processes in drifters were initiated after 2 days of exposure and they achieved complete acclimation by day 7. Sedentary settlers delay acclimation and at day 7 feeding activity had not resumed and energetic losses through respiration and excretion were higher at the lowest salinity treatment. Different responses facing salinity stress might be related to differences in habitat of each stage. For sedentary settlers which occupy relatively stable niches, energy optimisation include delaying the initiation of the energetically expensive acclimation processes while drifters which occupy less stable environments require a more flexible process which allow them to optimize energy acquisition as fast as possible.

Ecophysiology of avian migration in the face of current global hazards

PubMed Central

Klaassen, Marcel; Hoye, Bethany J.; Nolet, Bart A.; Buttemer, William A.

2012-01-01

Long-distance migratory birds are often considered extreme athletes, possessing a range of traits that approach the physiological limits of vertebrate design. In addition, their movements must be carefully timed to ensure that they obtain resources of sufficient quantity and quality to satisfy their high-energy needs. Migratory birds may therefore be particularly vulnerable to global change processes that are projected to alter the quality and quantity of resource availability. Because long-distance flight requires high and sustained aerobic capacity, even minor decreases in vitality can have large negative consequences for migrants. In the light of this, we assess how current global change processes may affect the ability of birds to meet the physiological demands of migration, and suggest areas where avian physiologists may help to identify potential hazards. Predicting the consequences of global change scenarios on migrant species requires (i) reconciliation of empirical and theoretical studies of avian flight physiology; (ii) an understanding of the effects of food quality, toxicants and disease on migrant performance; and (iii) mechanistic models that integrate abiotic and biotic factors to predict migratory behaviour. Critically, a multi-dimensional concept of vitality would greatly facilitate evaluation of the impact of various global change processes on the population dynamics of migratory birds. PMID:22566678

A physiology-based model describing heterogeneity in glucose metabolism: the core of the Eindhoven Diabetes Education Simulator (E-DES).

PubMed

Maas, Anne H; Rozendaal, Yvonne J W; van Pul, Carola; Hilbers, Peter A J; Cottaar, Ward J; Haak, Harm R; van Riel, Natal A W

2015-03-01

Current diabetes education methods are costly, time-consuming, and do not actively engage the patient. Here, we describe the development and verification of the physiological model for healthy subjects that forms the basis of the Eindhoven Diabetes Education Simulator (E-DES). E-DES shall provide diabetes patients with an individualized virtual practice environment incorporating the main factors that influence glycemic control: food, exercise, and medication. The physiological model consists of 4 compartments for which the inflow and outflow of glucose and insulin are calculated using 6 nonlinear coupled differential equations and 14 parameters. These parameters are estimated on 12 sets of oral glucose tolerance test (OGTT) data (226 healthy subjects) obtained from literature. The resulting parameter set is verified on 8 separate literature OGTT data sets (229 subjects). The model is considered verified if 95% of the glucose data points lie within an acceptance range of ±20% of the corresponding model value. All glucose data points of the verification data sets lie within the predefined acceptance range. Physiological processes represented in the model include insulin resistance and β-cell function. Adjusting the corresponding parameters allows to describe heterogeneity in the data and shows the capabilities of this model for individualization. We have verified the physiological model of the E-DES for healthy subjects. Heterogeneity of the data has successfully been modeled by adjusting the 4 parameters describing insulin resistance and β-cell function. Our model will form the basis of a simulator providing individualized education on glucose control. © 2014 Diabetes Technology Society.

Knowledge of the physiology of spore-forming bacteria can explain the origin of spores in the food environment.

PubMed

Gauvry, Emilie; Mathot, Anne-Gabrielle; Leguérinel, Ivan; Couvert, Olivier; Postollec, Florence; Broussolle, Véronique; Coroller, Louis

2017-05-01

Spore-forming bacteria are able to grow under a wide range of environmental conditions, to form biofilms and to differentiate into resistant forms: spores. This resistant form allows their dissemination in the environment; consequently, they may contaminate raw materials. Sporulation can occur all along the food chain, in raw materials, but also in food processes, leading to an increase in food contamination. However, the problem of sporulation during food processing is poorly addressed and sporulation niches are difficult to identify from the farm to the fork. Sporulation is a survival strategy. Some environmental factors are required to trigger this differentiation process and others act by modulating it. The efficiency of sporulation is the result of the combined effects of these two types of factors on vegetative cell metabolism. This paper aims to explain and help identify sporulation niches in the food chain, based on features of spore-former physiology. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Understanding the Logics of Pheromone Processing in the Honeybee Brain: From Labeled-Lines to Across-Fiber Patterns

PubMed Central

Sandoz, Jean-Christophe; Deisig, Nina; de Brito Sanchez, Maria Gabriela; Giurfa, Martin

2007-01-01

Honeybees employ a very rich repertoire of pheromones to ensure intraspecific communication in a wide range of behavioral contexts. This communication can be complex, since the same compounds can have a variety of physiological and behavioral effects depending on the receiver. Honeybees constitute an ideal model to study the neurobiological basis of pheromonal processing, as they are already one of the most influential animal models for the study of general odor processing and learning at behavioral, cellular and molecular levels. Accordingly, the anatomy of the bee brain is well characterized and electro- and opto-physiological recording techniques at different stages of the olfactory circuit are possible in the laboratory. Here we review pheromone communication in honeybees and analyze the different stages of olfactory processing in the honeybee brain, focusing on available data on pheromone detection, processing and representation at these different stages. In particular, we argue that the traditional distinction between labeled-line and across-fiber pattern processing, attributed to pheromone and general odors respectively, may not be so clear in the case of honeybees, especially for social-pheromones. We propose new research avenues for stimulating future work in this area. PMID:18958187

Distinctive receptive field and physiological properties of a wide-field amacrine cell in the macaque monkey retina

PubMed Central

Puller, Christian; Rieke, Fred; Neitz, Jay; Neitz, Maureen

2015-01-01

At early stages of visual processing, receptive fields are typically described as subtending local regions of space and thus performing computations on a narrow spatial scale. Nevertheless, stimulation well outside of the classical receptive field can exert clear and significant effects on visual processing. Given the distances over which they occur, the retinal mechanisms responsible for these long-range effects would certainly require signal propagation via active membrane properties. Here the physiology of a wide-field amacrine cell—the wiry cell—in macaque monkey retina is explored, revealing receptive fields that represent a striking departure from the classic structure. A single wiry cell integrates signals over wide regions of retina, 5–10 times larger than the classic receptive fields of most retinal ganglion cells. Wiry cells integrate signals over space much more effectively than predicted from passive signal propagation, and spatial integration is strongly attenuated during blockade of NMDA spikes but integration is insensitive to blockade of NaV channels with TTX. Thus these cells appear well suited for contributing to the long-range interactions of visual signals that characterize many aspects of visual perception. PMID:26133804

Genetics of Mitochondrial Disease.

PubMed

Saneto, Russell P

2017-01-01

Mitochondria are intracellular organelles responsible for adenosine triphosphate production. The strict control of intracellular energy needs require proper mitochondrial functioning. The mitochondria are under dual controls of mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). Mitochondrial dysfunction can arise from changes in either mtDNA or nDNA genes regulating function. There are an estimated ∼1500 proteins in the mitoproteome, whereas the mtDNA genome has 37 proteins. There are, to date, ∼275 genes shown to give rise to disease. The unique physiology of mitochondrial functioning contributes to diverse gene expression. The onset and range of phenotypic expression of disease is diverse, with onset from neonatal to seventh decade of life. The range of dysfunction is heterogeneous, ranging from single organ to multisystem involvement. The complexity of disease expression has severely limited gene discovery. Combining phenotypes with improvements in gene sequencing strategies are improving the diagnosis process. This chapter focuses on the interplay of the unique physiology and gene discovery in the current knowledge of genetically derived mitochondrial disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Thermal dependence of locomotor performance in two cool-temperate lizards.

PubMed

Gaby, Mya J; Besson, Anne A; Bezzina, Chalene N; Caldwell, Amanda J; Cosgrove, Sarai; Cree, Alison; Haresnape, Steff; Hare, Kelly M

2011-09-01

Temperate-zone ectotherms experience varying or very low ambient temperatures and may have difficulty in attaining preferred body temperatures. Thus, adaptations to reduce the thermal dependence of physiological processes may be present. We measured the optimal temperature range for sprint speed and compared it with the selected body temperatures (T (sel)) of two sympatric, cool-temperate lizards: the diurnal skink Oligosoma maccanni and the primarily nocturnal gecko Woodworthia (previously Hoplodactylus) "Otago/Southland". We also investigated whether time-of-day influenced sprint speed. Contrary to results for other reptiles, we found that time-of-day did not influence speed in either species. For each species, the optimal temperature range for sprinting and T (sel) overlapped, supporting the 'thermal coadaptation' hypothesis. However, the optimal range of temperatures for speed is not always attainable during activity by either species, which have limited opportunities to attain T (sel) in the field. The thermal sensitivity of sprint speed in these two species does not appear to have evolved to fully match their current thermal environment. More data on cold-adapted species are needed to fully understand physiological adaptation in ectotherms.

Environmental and Intrinsic Correlates of Stress in Free-Ranging Wolves

PubMed Central

Molnar, Barbara; Fattebert, Julien; Palme, Rupert; Ciucci, Paolo; Betschart, Bruno; Smith, Douglas W.; Diehl, Peter-Allan

2015-01-01

Background When confronted with a stressor, animals react with several physiological and behavioral responses. Although sustained or repeated stress can result in severe deleterious physiological effects, the causes of stress in free-ranging animals are yet poorly documented. In our study, we aimed at identifying the main factors affecting stress levels in free-ranging wolves (Canis lupus). Methodology/Principal Findings We used fecal cortisol metabolites (FCM) as an index of stress, after validating the method for its application in wolves. We analyzed a total of 450 fecal samples from eleven wolf packs belonging to three protected populations, in Italy (Abruzzo), France (Mercantour), and the United States (Yellowstone). We collected samples during two consecutive winters in each study area. We found no relationship between FCM concentrations and age, sex or social status of individuals. At the group level, our results suggest that breeding pair permanency and the loss of pack members through processes different from dispersal may importantly impact stress levels in wolves. We measured higher FCM levels in comparatively small packs living in sympatry with a population of free-ranging dogs. Lastly, our results indicate that FCM concentrations are associated with endoparasitic infections of individuals. Conclusions/Significance In social mammals sharing strong bonds among group members, the death of one or several members of the group most likely induces important stress in the remainder of the social unit. The potential impact of social and territorial stability on stress levels should be further investigated in free-ranging populations, especially in highly social and in territorial species. As persistent or repeated stressors may facilitate or induce pathologies and physiological alterations that can affect survival and fitness, we advocate considering the potential impact of anthropogenic causes of stress in management and conservation programs regarding wolves and other wildlife. PMID:26398784

Environmental and Intrinsic Correlates of Stress in Free-Ranging Wolves.

PubMed

Molnar, Barbara; Fattebert, Julien; Palme, Rupert; Ciucci, Paolo; Betschart, Bruno; Smith, Douglas W; Diehl, Peter-Allan

2015-01-01

When confronted with a stressor, animals react with several physiological and behavioral responses. Although sustained or repeated stress can result in severe deleterious physiological effects, the causes of stress in free-ranging animals are yet poorly documented. In our study, we aimed at identifying the main factors affecting stress levels in free-ranging wolves (Canis lupus). We used fecal cortisol metabolites (FCM) as an index of stress, after validating the method for its application in wolves. We analyzed a total of 450 fecal samples from eleven wolf packs belonging to three protected populations, in Italy (Abruzzo), France (Mercantour), and the United States (Yellowstone). We collected samples during two consecutive winters in each study area. We found no relationship between FCM concentrations and age, sex or social status of individuals. At the group level, our results suggest that breeding pair permanency and the loss of pack members through processes different from dispersal may importantly impact stress levels in wolves. We measured higher FCM levels in comparatively small packs living in sympatry with a population of free-ranging dogs. Lastly, our results indicate that FCM concentrations are associated with endoparasitic infections of individuals. In social mammals sharing strong bonds among group members, the death of one or several members of the group most likely induces important stress in the remainder of the social unit. The potential impact of social and territorial stability on stress levels should be further investigated in free-ranging populations, especially in highly social and in territorial species. As persistent or repeated stressors may facilitate or induce pathologies and physiological alterations that can affect survival and fitness, we advocate considering the potential impact of anthropogenic causes of stress in management and conservation programs regarding wolves and other wildlife.

Focus on the emerging new fields of network physiology and network medicine

NASA Astrophysics Data System (ADS)

Ivanov, Plamen Ch; Liu, Kang K. L.; Bartsch, Ronny P.

2016-10-01

Despite the vast progress and achievements in systems biology and integrative physiology in the last decades, there is still a significant gap in understanding the mechanisms through which (i) genomic, proteomic and metabolic factors and signaling pathways impact vertical processes across cells, tissues and organs leading to the expression of different disease phenotypes and influence the functional and clinical associations between diseases, and (ii) how diverse physiological systems and organs coordinate their functions over a broad range of space and time scales and horizontally integrate to generate distinct physiologic states at the organism level. Two emerging fields, network medicine and network physiology, aim to address these fundamental questions. Novel concepts and approaches derived from recent advances in network theory, coupled dynamical systems, statistical and computational physics show promise to provide new insights into the complexity of physiological structure and function in health and disease, bridging the genetic and sub-cellular level with inter-cellular interactions and communications among integrated organ systems and sub-systems. These advances form first building blocks in the methodological formalism and theoretical framework necessary to address fundamental problems and challenges in physiology and medicine. This ‘focus on’ issue contains 26 articles representing state-of-the-art contributions covering diverse systems from the sub-cellular to the organism level where physicists have key role in laying the foundations of these new fields.

Orientation dependent modulation of apparent speed: a model based on the dynamics of feed-forward and horizontal connectivity in V1 cortex.

PubMed

Seriès, Peggy; Georges, Sébastien; Lorenceau, Jean; Frégnac, Yves

2002-11-01

Psychophysical and physiological studies suggest that long-range horizontal connections in primary visual cortex participate in spatial integration and contour processing. Until recently, little attention has been paid to their intrinsic temporal properties. Recent physiological studies indicate, however, that the propagation of activity through long-range horizontal connections is slow, with time scales comparable to the perceptual scales involved in motion processing. Using a simple model of V1 connectivity, we explore some of the implications of this slow dynamics. The model predicts that V1 responses to a stimulus in the receptive field can be modulated by a previous stimulation, a few milliseconds to a few tens of milliseconds before, in the surround. We analyze this phenomenon and its possible consequences on speed perception, as a function of the spatio-temporal configuration of the visual inputs (relative orientation, spatial separation, temporal interval between the elements, sequence speed). We show that the dynamical interactions between feed-forward and horizontal signals in V1 can explain why the perceived speed of fast apparent motion sequences strongly depends on the orientation of their elements relative to the motion axis and can account for the range of speed for which this perceptual effect occurs (Georges, Seriès, Frégnac and Lorenceau, this issue).

Translational applications of evaluating physiologic variability in human endotoxemia

PubMed Central

Scheff, Jeremy D.; Mavroudis, Panteleimon D.; Calvano, Steve E.; Androulakis, Ioannis P.

2012-01-01

Dysregulation of the inflammatory response is a critical component of many clinically challenging disorders such as sepsis. Inflammation is a biological process designed to lead to healing and recovery, ultimately restoring homeostasis; however, the failure to fully achieve those beneficial results can leave a patient in a dangerous persistent inflammatory state. One of the primary challenges in developing novel therapies in this area is that inflammation is comprised of a complex network of interacting pathways. Here, we discuss our approaches towards addressing this problem through computational systems biology, with a particular focus on how the presence of biological rhythms and the disruption of these rhythms in inflammation may be applied in a translational context. By leveraging the information content embedded in physiologic variability, ranging in scale from oscillations in autonomic activity driving short-term heart rate variability (HRV) to circadian rhythms in immunomodulatory hormones, there is significant potential to gain insight into the underlying physiology. PMID:23203205

[The role of endocannabinoid system in physiological and pathological processes in the eye].

PubMed

Nadolska, Krystyna; Goś, Roman

2008-01-01

Plant of Cannabis sativa/ marihuana except for its psychotropic effects possesses a range of pharmacological properties, that has been utilized for medical purposes over a period of millenia. Investigations concerning biochemical mechanism of action of the main and most active pharmacological compound of Cannabis sativa, cannabinoid 9-THC, contributed to the discovery of cannabinoid receptors both in the central nervous system (CNS) and peripheral tissues, that mediated actions of this substance. The discovery made possible identification of a new, endogenous signaling system reffered to as the endocannabinoid system. Besides cannabinoid receptors CB1 and CB2, the system includes it's endogenic ligands (endocannabinoids) and compounds that participate in their biosynthesis and inactivation. Structure and functioning of the endocannabinoid system is conservative in all vertebrates. It's activation with plant, synthetic and endogenous cannabinoids has an influence on multiple physiological and pathological processes within the eye.

Spatial Autocorrelation Can Generate Stronger Correlations between Range Size and Climatic Niches Than the Biological Signal - A Demonstration Using Bird and Mammal Range Maps.

PubMed

Boucher-Lalonde, Véronique; Currie, David J

2016-01-01

Species' geographic ranges could primarily be physiological tolerances drawn in space. Alternatively, geographic ranges could be only broadly constrained by physiological climatic tolerances: there could generally be much more proximate constraints on species' ranges (dispersal limitation, biotic interactions, etc.) such that species often occupy a small and unpredictable subset of tolerable climates. In the literature, species' climatic tolerances are typically estimated from the set of conditions observed within their geographic range. Using this method, studies have concluded that broader climatic niches permit larger ranges. Similarly, other studies have investigated the biological causes of incomplete range filling. But, when climatic constraints are measured directly from species' ranges, are correlations between species' range size and climate necessarily consistent with a causal link? We evaluated the extent to which variation in range size among 3277 bird and 1659 mammal species occurring in the Americas is statistically related to characteristics of species' realized climatic niches. We then compared how these relationships differed from the ones expected in the absence of a causal link. We used a null model that randomizes the predictor variables (climate), while retaining their broad spatial autocorrelation structure, thereby removing any causal relationship between range size and climate. We found that, although range size is strongly positively related to climatic niche breadth, range filling and, to a lesser extent, niche position in nature, the observed relationships are not always stronger than expected from spatial autocorrelation alone. Thus, we conclude that equally strong relationships between range size and climate would result from any processes causing ranges to be highly spatially autocorrelated.

Spatial Autocorrelation Can Generate Stronger Correlations between Range Size and Climatic Niches Than the Biological Signal — A Demonstration Using Bird and Mammal Range Maps

PubMed Central

Boucher-Lalonde, Véronique; Currie, David J.

2016-01-01

Species’ geographic ranges could primarily be physiological tolerances drawn in space. Alternatively, geographic ranges could be only broadly constrained by physiological climatic tolerances: there could generally be much more proximate constraints on species’ ranges (dispersal limitation, biotic interactions, etc.) such that species often occupy a small and unpredictable subset of tolerable climates. In the literature, species’ climatic tolerances are typically estimated from the set of conditions observed within their geographic range. Using this method, studies have concluded that broader climatic niches permit larger ranges. Similarly, other studies have investigated the biological causes of incomplete range filling. But, when climatic constraints are measured directly from species’ ranges, are correlations between species’ range size and climate necessarily consistent with a causal link? We evaluated the extent to which variation in range size among 3277 bird and 1659 mammal species occurring in the Americas is statistically related to characteristics of species’ realized climatic niches. We then compared how these relationships differed from the ones expected in the absence of a causal link. We used a null model that randomizes the predictor variables (climate), while retaining their broad spatial autocorrelation structure, thereby removing any causal relationship between range size and climate. We found that, although range size is strongly positively related to climatic niche breadth, range filling and, to a lesser extent, niche position in nature, the observed relationships are not always stronger than expected from spatial autocorrelation alone. Thus, we conclude that equally strong relationships between range size and climate would result from any processes causing ranges to be highly spatially autocorrelated. PMID:27855201

Gene regulation by noncoding RNAs

PubMed Central

Patil, Veena S.; Zhou, Rui; Rana, Tariq M.

2015-01-01

The past two decades have seen an explosion in research on noncoding RNAs and their physiological and pathological functions. Several classes of small (20–30 nucleotides) and long (>200 nucleotides) noncoding RNAs have been firmly established as key regulators of gene expression in myriad processes ranging from embryonic development to innate immunity. In this review, we focus on our current understanding of the molecular mechanisms underlying the biogenesis and function of small interfering RNAs (siRNAs), microRNAs (miRNAs), and Piwi-interacting RNAs (piRNAs). In addition, we briefly review the relevance of small and long noncoding RNAs to human physiology and pathology and their potential to be exploited as therapeutic agents. PMID:24164576

Advanced Doppler radar physiological sensing technique for drone detection

NASA Astrophysics Data System (ADS)

Yoon, Ji Hwan; Xu, Hao; Garcia Carrillo, Luis R.

2017-05-01

A 24 GHz medium-range human detecting sensor, using the Doppler Radar Physiological Sensing (DRPS) technique, which can also detect unmanned aerial vehicles (UAVs or drones), is currently under development for potential rescue and anti-drone applications. DRPS systems are specifically designed to remotely monitor small movements of non-metallic human tissues such as cardiopulmonary activity and respiration. Once optimized, the unique capabilities of DRPS could be used to detect UAVs. Initial measurements have shown that DRPS technology is able to detect moving and stationary humans, as well as largely non-metallic multi-rotor drone helicopters. Further data processing will incorporate pattern recognition to detect multiple signatures (motor vibration and hovering patterns) of UAVs.

Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis.

PubMed

Gao, Wei; Emaminejad, Sam; Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; Lien, Der-Hsien; Brooks, George A; Davis, Ronald W; Javey, Ali

2016-01-28

Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual's state of health. Sampling human sweat, which is rich in physiological information, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications.

Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

NASA Astrophysics Data System (ADS)

Gao, Wei; Emaminejad, Sam; Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M.; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; Lien, Der-Hsien; Brooks, George A.; Davis, Ronald W.; Javey, Ali

2016-01-01

Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual’s state of health. Sampling human sweat, which is rich in physiological information, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications.

Meta-analysis of digital game and study characteristics eliciting physiological stress responses.

PubMed

van der Vijgh, Benny; Beun, Robbert-Jan; Van Rood, Maarten; Werkhoven, Peter

2015-08-01

Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We have therefore conducted a meta-analysis that analyzes the effects of characteristics of digital game stressors and study design on heart rate, systolic and diastolic blood pressure, in studies carried out from 1976 to 2012. In order to assess the differing quality between study designs, a new scale is developed and presented, coined reliability of effect size. The results show specific and consistent moderating functions of both game and study characteristics, on average accounting for around 43%, and in certain cases up to 57% of the variance found in physiological stress responses. Possible cognitive and physiological processes underlying these moderating functions are discussed, and a new model integrating these processes with the moderating functions is presented. These findings indicate that a digital game stressor does not act as a stressor by virtue of being a game, but rather derives its stressor function from its characteristics and the methodology in which it is used. This finding, together with the size of the associated moderations, indicates the need for a standardization of digital game stressors. © 2015 Society for Psychophysiological Research.

Hydrogen Sulfide in Renal Physiology and Disease.

PubMed

Feliers, Denis; Lee, Hak Joo; Kasinath, Balakuntalam S

2016-11-01

Hydrogen sulfide (H2S) has only recently gained recognition for its physiological effects. It is synthesized widely in the mammalian tissues and regulates several biologic processes ranging from development, angiogenesis, neurotransmission to protein synthesis. Recent Advances: The aim of this review is to critically evaluate the evidence for a role for H2S in kidney function and disease. H2S regulates fundamental kidney physiologic processes such as glomerular filtration and sodium reabsorption. In kidney disease states H2S appears to play a complex role in a context-dependent manner. In some disease states such as ischemia-reperfusion and diabetic kidney disease it can serve as an agent that ameliorates kidney injury. In other diseases such as cis-platinum-induced kidney disease it may mediate kidney injury although more investigation is needed. Recent studies have revealed that the actions of nitric oxide and H2S may be integrated in kidney cells. Further studies are needed to understand the full impact of H2S on kidney physiology. As it is endowed with the properties of regulating blood flow, oxidative stress, and inflammation, H2S should be investigated for its role in inflammatory and toxic diseases of the kidney. Such in-depth exploration may identify specific kidney diseases in which H2S may constitute a unique target for therapeutic intervention. Antioxid. Redox Signal. 25, 720-731.

Physiological mechanisms drive differing foliar calcium content in ferns and angiosperms.

PubMed

Funk, Jennifer L; Amatangelo, Kathryn L

2013-09-01

Recent evidence points to ferns containing significantly lower contents of foliar calcium and other cations than angiosperms. This is especially true of more ancient 'non-polypod' fern lineages, which predate the diversification of angiosperms. Calcium is an important plant nutrient, the lack of which can potentially slow plant growth and litter decomposition, and alter soil invertebrate communities. The physiological mechanisms limiting foliar calcium (Ca) content in ferns are unknown. While there is a lot we do not know about Ca uptake and transport in plants, three physiological processes are likely to be important. We measured transpiration rate, cation exchange capacity, and leaching loss to determine which process most strongly regulates foliar Ca content in a range of fern and co-occurring understory angiosperm species from a montane Hawaiian rainforest. We found higher instantaneous and lifetime (corrected for leaf lifespan) transpiration rates in angiosperms relative to ferns. Ferns preferentially incorporated Ca into leaves relative to strontium, which suggests that root or stem cation exchange capacity differs between ferns and angiosperms, potentially affecting calcium transport in plants. There were no differences in foliar Ca leaching loss between groups. Among the physiological mechanisms measured, foliar Ca was most strongly correlated with leaf-level transpiration rate and leaf lifespan. This suggests that inter-specific differences in a leaf's lifetime transpiration may play a significant role in determining plant nutrition.

No Evidence for Emotional Empathy in Chickens Observing Familiar Adult Conspecifics

PubMed Central

Edgar, Joanne L.; Paul, Elizabeth S.; Harris, Lauren; Penturn, Sarah; Nicol, Christine J.

2012-01-01

The capacity of animals to empathise is of high potential relevance to the welfare of group-housed domestic animals. Emotional empathy is a multifaceted and multilayered phenomenon which ranges from relatively simple processes such as emotional matching behaviour to more complex processes involving interaction between emotional and cognitive perspective taking systems. Our previous research has demonstrated that hens show clear behavioural and physiological responses to the mild distress of their chicks. To investigate whether this capacity exists outside the mother/offspring bond, we conducted a similar experiment in which domestic hens were exposed to the mild distress of unrelated, but familiar adult conspecifics. Each observer hen was exposed to two replicates of four conditions, in counterbalanced order; control (C); control with noise of air puff (CN); air puff to conspecific hen (APC); air puff to observer hen (APH). During each test, the observer hens' behaviour and physiology were measured throughout a 10 min pre-treatment and a 10 min treatment period. Despite showing signs of distress in response to an aversive stimulus directed at themselves (APH), and using methodology sufficiently sensitive to detect empathy-like responses previously, observer hens showed no behavioural or physiological responses to the mild distress of a familiar adult conspecific. The lack of behavioural and physiological response indicates that hens show no basis for emotional empathy in this context. PMID:22348100

Principal processes within the estuarine salinity gradient: a review.

PubMed

Telesh, Irena V; Khlebovich, Vladislav V

2010-01-01

The salinity gradient is one of the main features characteristic of any estuarine ecosystem. Within this gradient in a critical salinity range of 5-8 PSU the major biotic and abiotic processes demonstrate non-linear dynamics of change in rates and directions. In estuaries, this salinity range acts as both external ecological factor and physiological characteristics of internal environment of aquatic organisms; it divides living conditions appropriate for freshwater and marine faunas, separates invertebrate communities with different osmotic regulation types, and defines the distribution range of high taxa. In this paper, the non-linearity of biotic processes within the estuarine salinity gradient is illustrated by the data on zooplankton from the Baltic estuaries. The non-tidal Baltic Sea provides a good demonstration of the above phenomena due to gradual changes of environmental factors and relatively stable isohalines. The non-linearity concept coupled with the ecosystem approach served the basis for a new definition of an estuary proposed by the authors. Copyright 2010 Elsevier Ltd. All rights reserved.

A modular, programmable measurement system for physiological and spaceflight applications

NASA Technical Reports Server (NTRS)

Hines, John W.; Ricks, Robert D.; Miles, Christopher J.

1993-01-01

The NASA-Ames Sensors 2000! Program has developed a small, compact, modular, programmable, sensor signal conditioning and measurement system, initially targeted for Life Sciences Spaceflight Programs. The system consists of a twelve-slot, multi-layer, distributed function backplane, a digital microcontroller/memory subsystem, conditioned and isolated power supplies, and six application-specific, physiological signal conditioners. Each signal condition is capable of being programmed for gains, offsets, calibration and operate modes, and, in some cases, selectable outputs and functional modes. Presently, the system has the capability for measuring ECG, EMG, EEG, Temperature, Respiration, Pressure, Force, and Acceleration parameters, in physiological ranges. The measurement system makes heavy use of surface-mount packaging technology, resulting in plug in modules sized 125x55 mm. The complete 12-slot system is contained within a volume of 220x150x70mm. The system's capabilities extend well beyond the specific objectives of NASA programs. Indeed, the potential commercial uses of the technology are virtually limitless. In addition to applications in medical and biomedical sensing, the system might also be used in process control situations, in clinical or research environments, in general instrumentation systems, factory processing, or any other applications where high quality measurements are required.

A modular, programmable measurement system for physiological and spaceflight applications

NASA Astrophysics Data System (ADS)

Hines, John W.; Ricks, Robert D.; Miles, Christopher J.

1993-02-01

The NASA-Ames Sensors 2000] Program has developed a small, compact, modular, programmable, sensor signal conditioning and measurement system, initially targeted for Life Sciences Spaceflight Programs. The system consists of a twelve-slot, multi-layer, distributed function backplane, a digital microcontroller/memory subsystem, conditioned and isolated power supplies, and six application-specific, physiological signal conditioners. Each signal condition is capable of being programmed for gains, offsets, calibration and operate modes, and, in some cases, selectable outputs and functional modes. Presently, the system has the capability for measuring ECG, EMG, EEG, Temperature, Respiration, Pressure, Force, and Acceleration parameters, in physiological ranges. The measurement system makes heavy use of surface-mount packaging technology, resulting in plug in modules sized 125x55 mm. The complete 12-slot system is contained within a volume of 220x150x70mm. The system's capabilities extend well beyond the specific objectives of NASA programs. Indeed, the potential commercial uses of the technology are virtually limitless. In addition to applications in medical and biomedical sensing, the system might also be used in process control situations, in clinical or research environments, in general instrumentation systems, factory processing, or any other applications where high quality measurements are required.

Light during darkness and cancer: relationships in circadian photoreception and tumor biology.

PubMed

Jasser, Samar A; Blask, David E; Brainard, George C

2006-05-01

The relationship between circadian phototransduction and circadian-regulated processes is poorly understood. Melatonin, commonly a circadian phase marker, may play a direct role in a myriad of physiologic processes. The circadian rhythm for pineal melatonin secretion is regulated by the hypothalamic suprachiasmatic nucleus (SCN). Its neural source of light input is a unique subset of intrinsically photosensitive retinal ganglion cells expressing melanopsin, the primary circadian photopigment in rodents and primates. Action spectra of melatonin suppression by light have shown that light in the 446-477 nm range, distinct from the visual system's peak sensitivity, is optimal for stimulating the human circadian system. Breast cancer is the oncological disease entity whose relationship to circadian rhythm fluctuations has perhaps been most extensively studied. Empirical data has increasingly supported the hypothesis that higher risk of breast cancer in industrialized countries is partly due to increased exposure to light at night. Studies of tumor biology implicate melatonin as a potential mediator of this effect. Yet, causality between lifestyle factors and circadian tumor biology remains elusive and likely reflects significant variability with physiologic context. Continued rigorous empirical inquiry into the physiology and clinical implications of these habitual, integrated aspects of life is highly warranted at this time.

Seeing double: visual physiology of double-retina eye ontogeny in stomatopod crustaceans.

PubMed

Feller, Kathryn D; Cohen, Jonathan H; Cronin, Thomas W

2015-03-01

Stomatopod eye development is unusual among crustaceans. Just prior to metamorphosis, an adult retina and associated neuro-processing structures emerge adjacent to the existing material in the larval compound eye. Depending on the species, the duration of this double-retina eye can range from a few hours to several days. Although this developmental process occurs in all stomatopod species observed to date, the retinal physiology and extent to which each retina contributes to the animal's visual sensitivity during this transition phase is unknown. We investigated the visual physiology of stomatopod double retinas using microspectrophotometry and electroretinogram recordings from different developmental stages of the Western Atlantic species Squilla empusa. Though microspectrophotometry data were inconclusive, we found robust ERG responses in both larval and adult retinas at all sampled time points indicating that the adult retina responds to light from the very onset of its emergence. We also found evidence of an increase in the response dynamics with ontogeny as well as an increase in sensitivity of retinal tissue during the double-retina phase relative to single retinas. These data provide an initial investigation into the ontogeny of vision during stomatopod double-retina eye development.

Autophagy wins the 2016 Nobel Prize in Physiology or Medicine: Breakthroughs in baker's yeast fuel advances in biomedical research

PubMed Central

Levine, Beth; Klionsky, Daniel J.

2017-01-01

Autophagy is an ancient pathway in which parts of eukaryotic cells are self-digested within the lysosome or vacuole. This process has been studied for the past seven decades; however, we are only beginning to gain a molecular understanding of the key steps required for autophagy. Originally characterized as a hormonal and starvation response, we now know that autophagy has a much broader role in biology, including organellar remodeling, protein and organelle quality control, prevention of genotoxic stress, tumor suppression, pathogen elimination, regulation of immunity and inflammation, maternal DNA inheritance, metabolism, and cellular survival. Although autophagy is usually a degradative pathway, it also participates in biosynthetic and secretory processes. Given that autophagy has a fundamental role in many essential cellular functions, it is not surprising that autophagic dysfunction is associated with a wide range of human diseases. Genetic studies in various fungi, particularly Saccharomyces cerevisiae, provided the key initial breakthrough that led to an explosion of research on the basic mechanisms and the physiological connections of autophagy to health and disease. The Nobel Committee has recognized this breakthrough by the awarding of the 2016 Nobel Prize in Physiology or Medicine for research in autophagy. PMID:28039434

Integrating Cellular Metabolism into a Multiscale Whole-Body Model

PubMed Central

Krauss, Markus; Schaller, Stephan; Borchers, Steffen; Findeisen, Rolf; Lippert, Jörg; Kuepfer, Lars

2012-01-01

Cellular metabolism continuously processes an enormous range of external compounds into endogenous metabolites and is as such a key element in human physiology. The multifaceted physiological role of the metabolic network fulfilling the catalytic conversions can only be fully understood from a whole-body perspective where the causal interplay of the metabolic states of individual cells, the surrounding tissue and the whole organism are simultaneously considered. We here present an approach relying on dynamic flux balance analysis that allows the integration of metabolic networks at the cellular scale into standardized physiologically-based pharmacokinetic models at the whole-body level. To evaluate our approach we integrated a genome-scale network reconstruction of a human hepatocyte into the liver tissue of a physiologically-based pharmacokinetic model of a human adult. The resulting multiscale model was used to investigate hyperuricemia therapy, ammonia detoxification and paracetamol-induced toxication at a systems level. The specific models simultaneously integrate multiple layers of biological organization and offer mechanistic insights into pathology and medication. The approach presented may in future support a mechanistic understanding in diagnostics and drug development. PMID:23133351

Meeting Report: The Role of Environmental Lighting and Circadian Disruption in Cancer and Other Diseases

PubMed Central

Stevens, Richard G.; Blask, David E.; Brainard, George C.; Hansen, Johnni; Lockley, Steven W.; Provencio, Ignacio; Rea, Mark S.; Reinlib, Leslie

2007-01-01

Light, including artificial light, has a range of effects on human physiology and behavior and can therefore alter human physiology when inappropriately timed. One example of potential light-induced disruption is the effect of light on circadian organization, including the production of several hormone rhythms. Changes in light–dark exposure (e.g., by nonday occupation or transmeridian travel) shift the timing of the circadian system such that internal rhythms can become desynchronized from both the external environment and internally with each other, impairing our ability to sleep and wake at the appropriate times and compromising physiologic and metabolic processes. Light can also have direct acute effects on neuroendocrine systems, for example, in suppressing melatonin synthesis or elevating cortisol production that may have untoward long-term consequences. For these reasons, the National Institute of Environmental Health Sciences convened a workshop of a diverse group of scientists to consider how best to conduct research on possible connections between lighting and health. According to the participants in the workshop, there are three broad areas of research effort that need to be addressed. First are the basic biophysical and molecular genetic mechanisms for phototransduction for circadian, neuroendocrine, and neurobehavioral regulation. Second are the possible physiologic consequences of disrupting these circadian regulatory processes such as on hormone production, particularly melatonin, and normal and neoplastic tissue growth dynamics. Third are effects of light-induced physiologic disruption on disease occurrence and prognosis, and how prevention and treatment could be improved by application of this knowledge. PMID:17805428

Development and evaluation of spatial point process models for epidermal nerve fibers.

PubMed

Olsbo, Viktor; Myllymäki, Mari; Waller, Lance A; Särkkä, Aila

2013-06-01

We propose two spatial point process models for the spatial structure of epidermal nerve fibers (ENFs) across human skin. The models derive from two point processes, Φb and Φe, describing the locations of the base and end points of the fibers. Each point of Φe (the end point process) is connected to a unique point in Φb (the base point process). In the first model, both Φe and Φb are Poisson processes, yielding a null model of uniform coverage of the skin by end points and general baseline results and reference values for moments of key physiologic indicators. The second model provides a mechanistic model to generate end points for each base, and we model the branching structure more directly by defining Φe as a cluster process conditioned on the realization of Φb as its parent points. In both cases, we derive distributional properties for observable quantities of direct interest to neurologists such as the number of fibers per base, and the direction and range of fibers on the skin. We contrast both models by fitting them to data from skin blister biopsy images of ENFs and provide inference regarding physiological properties of ENFs. Copyright © 2013 Elsevier Inc. All rights reserved.

Contextual processing in unpredictable auditory environments: the limited resource model of auditory refractoriness in the rhesus

PubMed Central

Gurnsey, Kate; Salisbury, Dean; Sweet, Robert A.

2016-01-01

Auditory refractoriness refers to the finding of smaller electroencephalographic (EEG) responses to tones preceded by shorter periods of silence. To date, its physiological mechanisms remain unclear, limiting the insights gained from findings of abnormal refractoriness in individuals with schizophrenia. To resolve this roadblock, we studied auditory refractoriness in the rhesus, one of the most important animal models of auditory function, using grids of up to 32 chronically implanted cranial EEG electrodes. Four macaques passively listened to sounds whose identity and timing was random, thus preventing animals from forming valid predictions about upcoming sounds. Stimulus onset asynchrony ranged between 0.2 and 12.8 s, thus encompassing the clinically relevant timescale of refractoriness. Our results show refractoriness in all 8 previously identified middle- and long-latency components that peaked between 14 and 170 ms after tone onset. Refractoriness may reflect the formation and gradual decay of a basic sensory memory trace that may be mirrored by the expenditure and gradual recovery of a limited physiological resource that determines generator excitability. For all 8 components, results were consistent with the assumption that processing of each tone expends ∼65% of the available resource. Differences between components are caused by how quickly the resource recovers. Recovery time constants of different components ranged between 0.5 and 2 s. This work provides a solid conceptual, methodological, and computational foundation to dissect the physiological mechanisms of auditory refractoriness in the rhesus. Such knowledge may, in turn, help develop novel pharmacological, mechanism-targeted interventions. PMID:27512021

The Physiological Role of Abscisic Acid in Eliciting Turion Morphogenesis.

PubMed Central

Smart, C. C.; Fleming, A. J.; Chaloupkova, K.; Hanke, D. E.

1995-01-01

The exogenous application of hormones has led to their implication in a number of processes within the plant. However, proof of their function in vivo depends on quantitative data demonstrating that the exogenous concentration used to elicit a response leads to tissue hormone levels within the physiological range. Such proof is often lacking in many investigations. We are using abscisic acid (ABA)-induced turion formation in Spirodela polyrrhiza L. to investigate the mechanism by which a hormone can trigger a morphogenic switch. In this paper, we demonstrate that the exogenous concentration of ABA used to induce turions leads to tissue concentrations of ABA within the physiological range, as quantified by both enzyme-linked immunosorbent assay and high-performance liquid chromatography/gas chromatography-electron capture detection analysis. These results are consistent with ABA having a physiological role in turion formation, and they provide an estimate of the changes in endogenous ABA concentration required if environmental effectors of turion formation (e.g. nitrate deficiency, cold) act via an increased level of ABA. In addition, we show that the (+)- and (-)-enantiomers of ABA are equally effective in inducing turions. Moreover, comparison of the ABA; levels attained after treatment with (+)-, (-)-, and ([plus or minus])-ABA and their effect on turion induction and comparison of the effectiveness of ABA on turion induction under different pH regimes suggest that ABA most likely interacts with a plasmalemma-located receptor system to induce turion formation. PMID:12228499

Effects of Social Isolation on Glucocorticoid Regulation in Social Mammals

PubMed Central

Hawkley, Louise C.; Cole, Steve W.; Capitanio, John P.; Norman, Greg J.; Cacioppo, John T.

2012-01-01

The regulation and function of the hypothalamic-pituitary-adrenocortical (HPA) axis and glucocorticoids have been well conserved across vertebrate species. Glucocorticoids influence a wide range of physiological functions that include glucose regulation, metabolism, inflammatory control, as well as cardiovascular, reproductive, and neuronal effects. Some of these are relatively quick-acting non-genomic effects, but most are slower-acting genomic effects. Thus, any stimulus that affects HPA function has the potential to exert wide-ranging short-term and long-term effects on much of vertebrate physiology. Here, we review the effects of social isolation on the functioning of the HPA axis in social species, and on glucocorticoid physiology in social mammals in particular. Evidence indicates that objective and perceived social isolation alter HPA regulation, although the nature and direction of the HPA response differs among species and across age. The inconsistencies in the direction and nature of HPA effects have implications for drawing cross-species conclusions about the effects of social isolation, and are particularly problematic for understanding HPA-related physiological processes in humans. The animal and human data are incommensurate because, for example, animal studies of objective isolation have typically not been modeled on, or for comparability with, the subjective experience of isolation in humans. An animal model of human isolation must be taken more seriously if we want to advance our understanding of the mechanisms for the effects of objective and perceived isolation in humans. PMID:22663934

Review of Stress and the Measurement of Stress in Marine Mammals

DTIC Science & Technology

2013-09-30

massey.ac.nz Award Number: N000141110434 LONG-TERM GOALS Physiological indicators of stress in wild marine mammals, the interrelationships between...hormones (GC), aldosterone (A), thyroid hormones (TH), and catecholamines within a free-ranging northern elephant seal population and its dependence upon...individuals per year). Serum samples will be processed for ACTH, cortisol, aldosterone , catecholamines (epinephrine, norepinephrine), and TH (T3

Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-Sectional Sample of Elephant Seals

DTIC Science & Technology

2011-09-30

massey.ac.nz Award Number: N000141110434 LONG-TERM GOALS Physiological indicators of stress in wild marine mammals, the interrelationships between...hormones (GC), aldosterone (A), thyroid hormones (TH), and catecholamines within a free-ranging northern elephant seal population and its...additional individuals per year). Serum samples will be processed for ACTH, cortisol, aldosterone , catecholamines (epinephrine, norepinephrine), and

Climate warming causes life-history evolution in a model for Atlantic cod (Gadus morhua).

PubMed

Holt, Rebecca E; Jørgensen, Christian

2014-01-01

Climate change influences the marine environment, with ocean warming being the foremost driving factor governing changes in the physiology and ecology of fish. At the individual level, increasing temperature influences bioenergetics and numerous physiological and life-history processes, which have consequences for the population level and beyond. We provide a state-dependent energy allocation model that predicts temperature-induced adaptations for life histories and behaviour for the North-East Arctic stock (NEA) of Atlantic cod (Gadus morhua) in response to climate warming. The key constraint is temperature-dependent respiratory physiology, and the model includes a number of trade-offs that reflect key physiological and ecological processes. Dynamic programming is used to find an evolutionarily optimal strategy of foraging and energy allocation that maximizes expected lifetime reproductive output given constraints from physiology and ecology. The optimal strategy is then simulated in a population, where survival, foraging behaviour, growth, maturation and reproduction emerge. Using current forcing, the model reproduces patterns of growth, size-at-age, maturation, gonad production and natural mortality for NEA cod. The predicted climate responses are positive for this stock; under a 2°C warming, the model predicted increased growth rates and a larger asymptotic size. Maturation age was unaffected, but gonad weight was predicted to more than double. Predictions for a wider range of temperatures, from 2 to 7°C, show that temperature responses were gradual; fish were predicted to grow faster and increase reproductive investment at higher temperatures. An emergent pattern of higher risk acceptance and increased foraging behaviour was also predicted. Our results provide important insight into the effects of climate warming on NEA cod by revealing the underlying mechanisms and drivers of change. We show how temperature-induced adaptations of behaviour and several life-history traits are not only mediated by physiology but also by trade-offs with survival, which has consequences for conservation physiology.

Climate warming causes life-history evolution in a model for Atlantic cod (Gadus morhua)

PubMed Central

Holt, Rebecca E.; Jørgensen, Christian

2014-01-01

Climate change influences the marine environment, with ocean warming being the foremost driving factor governing changes in the physiology and ecology of fish. At the individual level, increasing temperature influences bioenergetics and numerous physiological and life-history processes, which have consequences for the population level and beyond. We provide a state-dependent energy allocation model that predicts temperature-induced adaptations for life histories and behaviour for the North-East Arctic stock (NEA) of Atlantic cod (Gadus morhua) in response to climate warming. The key constraint is temperature-dependent respiratory physiology, and the model includes a number of trade-offs that reflect key physiological and ecological processes. Dynamic programming is used to find an evolutionarily optimal strategy of foraging and energy allocation that maximizes expected lifetime reproductive output given constraints from physiology and ecology. The optimal strategy is then simulated in a population, where survival, foraging behaviour, growth, maturation and reproduction emerge. Using current forcing, the model reproduces patterns of growth, size-at-age, maturation, gonad production and natural mortality for NEA cod. The predicted climate responses are positive for this stock; under a 2°C warming, the model predicted increased growth rates and a larger asymptotic size. Maturation age was unaffected, but gonad weight was predicted to more than double. Predictions for a wider range of temperatures, from 2 to 7°C, show that temperature responses were gradual; fish were predicted to grow faster and increase reproductive investment at higher temperatures. An emergent pattern of higher risk acceptance and increased foraging behaviour was also predicted. Our results provide important insight into the effects of climate warming on NEA cod by revealing the underlying mechanisms and drivers of change. We show how temperature-induced adaptations of behaviour and several life-history traits are not only mediated by physiology but also by trade-offs with survival, which has consequences for conservation physiology. PMID:27293671

Ways to be different: foraging adaptations that facilitate higher intake rates in a northerly-wintering shorebird compared to a low-latitude conspecific

USGS Publications Warehouse

Ruthrauff, Daniel R.; Dekinga, Anne; Gill, Robert E.; van Gils, Jan A.; Piersma, Theunis

2015-01-01

At what phenotypic level do closely related subspecies that live in different environments differ with respect to food detection, ingestion, and processing? This question motivated an experimental study on rock sandpipers (Calidris ptilocnemis). The species' nonbreeding range spans 20 degrees of latitude, the extremes of which are inhabited by two subspecies: Calidris p. ptilocnemis that winters primarily in upper Cook Inlet, Alaska (61°N), and C. p. tschuktschorum that overlaps slightly with C. p. ptilocnemis but whose range extends much farther south (~40°N). In view of the strongly contrasting energetic demands of their distinct nonbreeding distributions, we conducted experiments to assess the behavioural, physiological, and sensory aspects of foraging, and we used the bivalve Macoma balthica for all trials. Ptilocnemis consumed a wider range of prey sizes, had higher maximum rates of energy intake, processed shell waste at higher maximum rates, and handled prey more quickly. Notably, however, the two subspecies did not differ in their abilities to find buried prey. The subspecies were similar in size and had equally sized gizzards, but the more northern ptilocnemis individuals were 10-14% heavier than their same-sex tschuktschorum counterparts. The higher body mass in ptilocnemis likely resulted from hypertrophy of digestive organs (e.g. intestine, liver) related to digestion and nutrient assimilation. Given the previously established equality of the two subspecies' metabolic capacities, we propose that the high-latitude nonbreeding range of ptilocnemis rock sandpipers is primarily facilitated by digestive (i.e. physiological) aspects of their foraging ecology rather than behavioural or sensory aspects.

Light and Cognition: Roles for Circadian Rhythms, Sleep, and Arousal

PubMed Central

Fisk, Angus S.; Tam, Shu K. E.; Brown, Laurence A.; Vyazovskiy, Vladyslav V.; Bannerman, David M.; Peirson, Stuart N.

2018-01-01

Light exerts a wide range of effects on mammalian physiology and behavior. As well as synchronizing circadian rhythms to the external environment, light has been shown to modulate autonomic and neuroendocrine responses as well as regulating sleep and influencing cognitive processes such as attention, arousal, and performance. The last two decades have seen major advances in our understanding of the retinal photoreceptors that mediate these non-image forming responses to light, as well as the neural pathways and molecular mechanisms by which circadian rhythms are generated and entrained to the external light/dark (LD) cycle. By contrast, our understanding of the mechanisms by which lighting influences cognitive processes is more equivocal. The effects of light on different cognitive processes are complex. As well as the direct effects of light on alertness, indirect effects may also occur due to disrupted circadian entrainment. Despite the widespread use of disrupted LD cycles to study the role circadian rhythms on cognition, the different experimental protocols used have subtly different effects on circadian function which are not always comparable. Moreover, these protocols will also disrupt sleep and alter physiological arousal, both of which are known to modulate cognition. Studies have used different assays that are dependent on different cognitive and sensory processes, which may also contribute to their variable findings. Here, we propose that studies addressing the effects of different lighting conditions on cognitive processes must also account for their effects on circadian rhythms, sleep, and arousal if we are to fully understand the physiological basis of these responses. PMID:29479335

Physiology undergraduate degree requirements in the U.S.

PubMed

VanRyn, Valerie S; Poteracki, James M; Wehrwein, Erica A

2017-12-01

Course-level learning objectives and core concepts for undergraduate physiology teaching exist. The next step is to consider how these resources fit into generalizable program-level guidelines for Bachelor of Science (BS) degrees in Physiology. In the absence of program-level guidelines for Physiology degree programs, we compiled a selective internal report to review degree requirements from 18 peer BS programs entitled "Physiology" in the United States (U.S.). There was a range of zero to three required semesters of math, physics, physics laboratory, general biology, biology laboratory, general chemistry, chemistry laboratory, organic chemistry, organic chemistry laboratory, biochemistry, biochemistry laboratory, anatomy, anatomy laboratory, core systems physiology, and physiology laboratory. Required upper division credits ranged from 11 to 31 and included system-specific, exercise and environmental, clinically relevant, pathology/disease-related, and basic science options. We hope that this information will be useful for all programs that consider themselves to be physiology, regardless of name. Reports such as this can serve as a starting point for collaboration among BS programs to improve physiology undergraduate education and best serve our students. Copyright © 2017 the American Physiological Society.

An instructional design process based on expert knowledge for teaching students how mechanisms are explained.

PubMed

Trujillo, Caleb M; Anderson, Trevor R; Pelaez, Nancy J

2016-06-01

In biology and physiology courses, students face many difficulties when learning to explain mechanisms, a topic that is demanding due to the immense complexity and abstract nature of molecular and cellular mechanisms. To overcome these difficulties, we asked the following question: how does an instructor transform their understanding of biological mechanisms and other difficult-to-learn topics so that students can comprehend them? To address this question, we first reviewed a model of the components used by biologists to explain molecular and cellular mechanisms: the MACH model, with the components of methods (M), analogies (A), context (C), and how (H). Next, instructional materials were developed and the teaching activities were piloted with a physical MACH model. Students who used the MACH model to guide their explanations of mechanisms exhibited both improvements and some new difficulties. Third, a series of design-based research cycles was applied to bring the activities with an improved physical MACH model into biology and biochemistry courses. Finally, a useful rubric was developed to address prevalent student difficulties. Here, we present, for physiology and biology instructors, the knowledge and resources for explaining molecular and cellular mechanisms in undergraduate courses with an instructional design process aimed at realizing pedagogical content knowledge for teaching. Our four-stage process could be adapted to advance instruction with a range of models in the life sciences. Copyright © 2016 The American Physiological Society.

Performance in physiology evaluation: possible improvement by active learning strategies.

PubMed

Montrezor, Luís H

2016-12-01

The evaluation process is complex and extremely important in the teaching/learning process. Evaluations are constantly employed in the classroom to assist students in the learning process and to help teachers improve the teaching process. The use of active methodologies encourages students to participate in the learning process, encourages interaction with their peers, and stimulates thinking about physiological mechanisms. This study examined the performance of medical students on physiology over four semesters with and without active engagement methodologies. Four activities were used: a puzzle, a board game, a debate, and a video. The results show that engaging in activities with active methodologies before a physiology cognitive monitoring test significantly improved student performance compared with not performing the activities. We integrate the use of these methodologies with classic lectures, and this integration appears to improve the teaching/learning process in the discipline of physiology and improves the integration of physiology with cardiology and neurology. In addition, students enjoy the activities and perform better on their evaluations when they use them. Copyright © 2016 The American Physiological Society.

Predictability of physiological testing and the role of maturation in talent identification for adolescent team sports.

PubMed

Pearson, D T; Naughton, G A; Torode, M

2006-08-01

Entrepreneurial marketing of sport increases demands on sport development officers to identify talented individuals for specialist development at the youngest possible age. Talent identification results in the streamlining of resources to produce optimal returns from a sports investment. However, the process of talent identification for team sports is complex and success prediction is imperfect. The aim of this review is to describe existing practices in physiological tests used for talent identification in team sports and discuss the impact of maturity-related differences on the long term outcomes particularly for male participants. Maturation is a major confounding variable in talent identification during adolescence. A myriad of hormonal changes during puberty results in physical and physiological characteristics important for sporting performance. Significant changes during puberty make the prediction of adult performance difficult from adolescent data. Furthermore, for talent identification programs to succeed, valid and reliable testing procedures must be accepted and implemented in a range of performance-related categories. Limited success in scientifically based talent identification is evident in a range of team sports. Genetic advances challenge the ethics of talent identification in adolescent sport. However, the environment remains a significant component of success prediction in sport. Considerations for supporting talented young male athletes are discussed.

Source-sink-storage relationships of conifers

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

Luxmoore, R.J.; Oren, R.; Sheriff, D.W.

1995-07-01

Irradiance, air temperature, saturation vapor pressure deficit, and soil temperature vary in association with Earth`s daily rotation, inducing significant hourly changes in the rates of plant physiological processes. These processes include carbon fixation in photosynthesis, sucrose translocation, and carbon utilization in growth, storage, and respiration. The sensitivity of these physiological processes to environmental factors such as temperature, soil water availability, and nutrient supply reveals differences that must be viewed as an interactive whole in order to comprehend whole-plant responses to the environment. Integrative frameworks for relationships between plant physiological processes are needed to provide syntheses of plant growth and development.more » Source-sink-storage relationships, addressed in this chapter, provide one framework for synthesis of whole-plant responses to external environmental variables. To address this issue, some examples of carbon assimilation and utilization responses of five conifer species to environmental factors from a range of field environments are first summarized. Next, the interactions between sources, sinks, and storages of carbon are examined at the leaf and tree scales, and finally, the review evaluates the proposition that processes involved with carbon utilization (sink activity) are more sensitive to the supply of water and nutrients (particularly nitrogen) than are the processes of carbon gain (source activity) and carbon storage. The terms {open_quotes}sink{close_quotes} and {open_quotes}source{close_quotes} refer to carbon utilization and carbon gain, respectively. The relative roles of stored carbon reserves and of current photosynthate in meeting sink demand are addressed. Discussions focus on source-sink-storage relationships within the diurnal, wetting-drying, and annual cycles of conifer growth and development, and some discussion of life cycle aspects is also presented.« less

Physiological changes in neurodegeneration - mechanistic insights and clinical utility.

PubMed

Ahmed, Rebekah M; Ke, Yazi D; Vucic, Steve; Ittner, Lars M; Seeley, William; Hodges, John R; Piguet, Olivier; Halliday, Glenda; Kiernan, Matthew C

2018-05-01

The effects of neurodegenerative syndromes extend beyond cognitive function to involve key physiological processes, including eating and metabolism, autonomic nervous system function, sleep, and motor function. Changes in these physiological processes are present in several conditions, including frontotemporal dementia, amyotrophic lateral sclerosis, Alzheimer disease and the parkinsonian plus conditions. Key neural structures that mediate physiological changes across these conditions include neuroendocrine and hypothalamic pathways, reward pathways, motor systems and the autonomic nervous system. In this Review, we highlight the key changes in physiological processing in neurodegenerative syndromes and the similarities in these changes between different progressive neurodegenerative brain conditions. The changes and similarities between disorders might provide novel insights into the human neural correlates of physiological functioning. Given the evidence that physiological changes can arise early in the neurodegenerative process, these changes could provide biomarkers to aid in the early diagnosis of neurodegenerative diseases and in treatment trials.

Dietary fibers from mushroom Sclerotia: 2. In vitro mineral binding capacity under sequential simulated physiological conditions of the human gastrointestinal tract.

PubMed

Wong, Ka-Hing; Cheung, Peter C K

2005-11-30

The in vitro mineral binding capacity of three novel dietary fibers (DFs) prepared from mushroom sclerotia, namely, Pleurotus tuber-regium, Polyporous rhinocerus, and Wolfiporia cocos, to Ca, Mg, Cu, Fe, and Zn under sequential simulated physiological conditions of the human stomach, small intestine, and colon was investigated and compared. Apart from releasing most of their endogenous Ca (ranged from 96.9 to 97.9% removal) and Mg (ranged from 95.9 to 96.7% removal), simulated physiological conditions of the stomach also attenuated the possible adverse binding effect of the three sclerotial DFs to the exogenous minerals by lowering their cation-exchange capacity (ranged from 20.8 to 32.3%) and removing a substantial amount of their potential mineral chelators including protein (ranged from 16.2 to 37.8%) and phytate (ranged from 58.5 to 64.2%). The in vitro mineral binding capacity of the three sclerotial DF under simulated physiological conditions of small intestine was found to be low, especially for Ca (ranged from 4.79 to 5.91% binding) and Mg (ranged from 3.16 to 4.18% binding), and was highly correlated (r > 0.97) with their residual protein contents. Under simulated physiological conditions of the colon with slightly acidic pH (5.80), only bound Ca was readily released (ranged from 34.2 to 72.3% releasing) from the three sclerotial DFs, and their potential enhancing effect on passive Ca absorption in the human large intestine was also discussed.

Challenges of ambulatory physiological sensing.

PubMed

Healey, Jennifer

2004-01-01

Applications for ambulatory monitoring span the spectrum from fitness optimization to cardiac defibrillation. This range of applications is associated with a corresponding range of required detection accuracies and a range of inconvenience and discomfort that wearers are willing to tolerate. This paper describes a selection of physiological sensors and how they might best be worn in the unconstrained ambulatory environment to provide the most robust measurements and the greatest comfort to the wearer. Using wireless mobile computing devices, it will be possible to record, analyze and respond to changes in the wearers' physiological signals in real time using these sensors.

Rice Physiology

Treesearch

P.A. Counce; Davidi R. Gealy; Shi-Jean Susana Sung

2002-01-01

Physiology occurs tn physical space through chemical reactions constrained by anatomy and morphology, yet guided by genetics. Physiology has been called the logic of life. Genes encode structural and fimcdonal proteins. These proteins are subsequently processed to produce enzymes that direct and govern the biomechanical processes involved in the physiology of the...

Kinetic Theory and Simulation of Single-Channel Water Transport

NASA Astrophysics Data System (ADS)

Tajkhorshid, Emad; Zhu, Fangqiang; Schulten, Klaus

Water translocation between various compartments of a system is a fundamental process in biology of all living cells and in a wide variety of technological problems. The process is of interest in different fields of physiology, physical chemistry, and physics, and many scientists have tried to describe the process through physical models. Owing to advances in computer simulation of molecular processes at an atomic level, water transport has been studied in a variety of molecular systems ranging from biological water channels to artificial nanotubes. While simulations have successfully described various kinetic aspects of water transport, offering a simple, unified model to describe trans-channel translocation of water turned out to be a nontrivial task.

A simple and fast representation space for classifying complex time series

NASA Astrophysics Data System (ADS)

Zunino, Luciano; Olivares, Felipe; Bariviera, Aurelio F.; Rosso, Osvaldo A.

2017-03-01

In the context of time series analysis considerable effort has been directed towards the implementation of efficient discriminating statistical quantifiers. Very recently, a simple and fast representation space has been introduced, namely the number of turning points versus the Abbe value. It is able to separate time series from stationary and non-stationary processes with long-range dependences. In this work we show that this bidimensional approach is useful for distinguishing complex time series: different sets of financial and physiological data are efficiently discriminated. Additionally, a multiscale generalization that takes into account the multiple time scales often involved in complex systems has been also proposed. This multiscale analysis is essential to reach a higher discriminative power between physiological time series in health and disease.

Excitatory amino acid neurotoxicity and neurodegenerative disease.

PubMed

Meldrum, B; Garthwaite, J

1990-09-01

The progress over the last 30 years in defining the role of excitatory amino acids in normal physiological function and in the abnormal neuronal activity of epilepsy has been reviewed in earlier articles in this series. In the last five years it has become clear that excitatory amino acids also play a role in a wide range of neurodegenerative processes. The evidence is clearest where the degenerative process is acute, but is more controversial for slow degenerative processes. In this article Brian Meldrum and John Garthwaite review in vivo and in vitro studies of the cytotoxicity of amino acids and summarize the contribution of such toxicity to acute and chronic neurodegenerative disorders.

The role of thermal physiology in recent declines of birds in a biodiversity hotspot.

PubMed

Milne, Robyn; Cunningham, Susan J; Lee, Alan T K; Smit, Ben

2015-01-01

We investigated whether observed avian range contractions and population declines in the Fynbos biome of South Africa were mechanistically linked to recent climate warming. We aimed to determine whether there were correlations between preferred temperature envelope, or changes in temperature within species' ranges, and recent changes in range and population size, for 12 Fynbos-resident bird species, including six that are endemic to the biome. We then measured the physiological responses of each species at air temperatures ranging from 24 to 42°C to determine whether physiological thermal thresholds could provide a mechanistic explanation for observed population trends. Our data show that Fynbos-endemic species occupying the coolest regions experienced the greatest recent reductions in range and population size (>30% range reduction between 1991 and the present). In addition, species experiencing the largest increases in air temperature within their ranges showed the greatest declines. However, evidence for a physiological mechanistic link between warming and population declines was equivocal, with only the larger species showing low thermal thresholds for their body mass, compared with other birds globally. In addition, some species appear more vulnerable than others to air temperatures in their ranges above physiological thermal thresholds. Of these, the high-altitude specialist Cape rockjumper (Chaetops frenatus) seems most at risk from climate warming. This species showed: (i) the lowest threshold for increasing evaporative water loss at high temperatures; and (ii) population declines specifically in those regions of its range recording significant warming trends. Our findings suggest that caution must be taken when attributing causality explicitly to thermal stress, even when population trends are clearly correlated with rates of warming. Studies explicitly investigating the mechanisms underlying such correlations will be key to appropriate conservation planning.

The role of thermal physiology in recent declines of birds in a biodiversity hotspot

PubMed Central

Milne, Robyn; Cunningham, Susan J; Lee, Alan T K

2015-01-01

Abstract We investigated whether observed avian range contractions and population declines in the Fynbos biome of South Africa were mechanistically linked to recent climate warming. We aimed to determine whether there were correlations between preferred temperature envelope, or changes in temperature within species' ranges, and recent changes in range and population size, for 12 Fynbos-resident bird species, including six that are endemic to the biome. We then measured the physiological responses of each species at air temperatures ranging from 24 to 42°C to determine whether physiological thermal thresholds could provide a mechanistic explanation for observed population trends. Our data show that Fynbos-endemic species occupying the coolest regions experienced the greatest recent reductions in range and population size (>30% range reduction between 1991 and the present). In addition, species experiencing the largest increases in air temperature within their ranges showed the greatest declines. However, evidence for a physiological mechanistic link between warming and population declines was equivocal, with only the larger species showing low thermal thresholds for their body mass, compared with other birds globally. In addition, some species appear more vulnerable than others to air temperatures in their ranges above physiological thermal thresholds. Of these, the high-altitude specialist Cape rockjumper (Chaetops frenatus) seems most at risk from climate warming. This species showed: (i) the lowest threshold for increasing evaporative water loss at high temperatures; and (ii) population declines specifically in those regions of its range recording significant warming trends. Our findings suggest that caution must be taken when attributing causality explicitly to thermal stress, even when population trends are clearly correlated with rates of warming. Studies explicitly investigating the mechanisms underlying such correlations will be key to appropriate conservation planning. PMID:27293732

Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

PubMed Central

Nyein, Hnin Yin Yin; Challa, Samyuktha; Chen, Kevin; Peck, Austin; Fahad, Hossain M.; Ota, Hiroki; Shiraki, Hiroshi; Kiriya, Daisuke; Lien, Der-Hsien; Brooks, George A.; Davis, Ronald W.; Javey, Ali

2016-01-01

Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual's state of health1–12. Sampling human sweat, which is rich in physiological information13, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state14–18. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications. PMID:26819044

Cell-derived microparticles in haemostasis and vascular medicine.

PubMed

Burnier, Laurent; Fontana, Pierre; Kwak, Brenda R; Angelillo-Scherrer, Anne

2009-03-01

Considerable interest for cell-derived microparticles has emerged, pointing out their essential role in haemostatic response and their potential as disease markers, but also their implication in a wide range of physiological and pathological processes. They derive from different cell types including platelets - the main source of microparticles - but also from red blood cells, leukocytes and endothelial cells, and they circulate in blood. Despite difficulties encountered in analyzing them and disparities of results obtained with a wide range of methods, microparticle generation processes are now better understood. However, a generally admitted definition of microparticles is currently lacking. For all these reasons we decided to review the literature regarding microparticles in their widest definition, including ectosomes and exosomes, and to focus mainly on their role in haemostasis and vascular medicine.

Exercise, physiological function, and the selection of participants for aging research.

PubMed

Lazarus, Norman R; Harridge, Stephen D R

2010-08-01

Regular and vigorous exercisers appear to be the logical choice for studying the inherent aging process as they are essentially free from the complications of disuse. Cross-sectional studies of aging tend to depict an essentially smooth and progressive decrement of physiological function with increasing chronological age. On closer examination of such data, it is seen that although the young have high functional values and the very old low, between these limits, values are widely scattered. We have reevaluated published data from a meta-analysis of 242 studies on men and from a similar study on women. From both data sets, where VO2max was plotted against chronological age, we stratified the VO2max values into bandwidth intervals of 5 ml/kg/minute and then allocated data points to their respective bandwidth irrespective of chronological age. When replotted into bandwidths of functional equivalence, these data show that at the extremes of function, the young are separated from the old. Between these values, each functional bandwidth accommodates a wide age range. The decrement in function with chronological age is not smooth or well defined. We suggest that participants for research into healthy aging should be initially segregated into bands of functionally equivalent VO2max values irrespective of their chronological age. Subsequently, other physiological measurements should be made on every participant in the band in order to begin to define the physiological profile of the participants. By conducting longitudinal studies on every individual, it will be possible to chart the physiological history of each participant through various ages. Segregating participants into cohorts of functional equivalence with data handling blinded to chronological age may be of great utility in increasing our understanding of the inherent aging process.

Scale dependency of forest functional diversity assessed using imaging spectroscopy and airborne laser scanning

NASA Astrophysics Data System (ADS)

Schneider, F. D.; Morsdorf, F.; Schmid, B.; Petchey, O. L.; Hueni, A.; Schimel, D.; Schaepman, M. E.

2016-12-01

Forest functional traits offer a mechanistic link between ecological processes and community structure and assembly rules. However, measuring functional traits of forests in a continuous and consistent way is particularly difficult due to the complexity of in-situ measurements and geo-referencing. New imaging spectroscopy measurements overcome these limitations allowing to map physiological traits on broad spatial scales. We mapped leaf chlorophyll, carotenoids and leaf water content over 900 ha of temperate mixed forest (Fig. 1a). The selected traits are functionally important because they are indicating the photosynthetic potential of trees, leaf longevity and protection, as well as tree water and drought stress. Spatially continuous measurements on the scale of individual tree crowns allowed to assess functional diversity patterns on a range of ecological extents. We used indexes of functional richness, divergence and evenness to map different aspects of diversity. Fig. 1b shows an example of physiological richness at an extent of 240 m radius. We compared physiological to morphological diversity patterns, derived based on plant area index, canopy height and foliage height diversity. Our results show that patterns of physiological and morphological diversity generally agree, independently measured by airborne imaging spectroscopy and airborne laser scanning, respectively. The occurrence of disturbance areas and mixtures of broadleaf and needle trees were the main drivers of the observed diversity patterns. Spatial patterns at varying extents and richness-area relationships indicated that environmental filtering is the predominant community assembly process. Our results demonstrate the potential for mapping physiological and morphological diversity in a temperate mixed forest between and within species on scales relevant to study community assembly and structure from space and test the corresponding measurement schemes.

Direct spectrophotometric measurement of supra-physiological levels of ascorbate in plasma.

PubMed

Witmer, Jordan R; Wetherell, Bailey J; Wagner, Brett A; Du, Juan; Cullen, Joseph J; Buettner, Garry R

2016-08-01

Supra-physiological concentrations of ascorbate, vitamin C, in blood, greater than 1mM, achieved through intravenous administration (IV), are being tested in clinical trials to treat human disease, e.g. cancer. These trials need information on the high levels of ascorbate achieved in blood upon IV administration of pharmacological ascorbate so appropriate clinical decisions can be made. Here we demonstrate that in the complex matrix of human blood plasma supra-physiological levels of ascorbate can be quantified by direct UV spectroscopy with use of a microvolume UV-vis spectrophotometer. Direct quantitation of ascorbate in plasma in the range of 2.9mM, lower limit of detection, up to at least 35mM can be achieved without any sample processing, other than centrifugation. This approach is rapid, economical, and can be used to quantify supraphysiological blood levels of ascorbate associated with the use of IV administration of pharmacological ascorbate to treat disease. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Hippocampal mechanisms for the context-dependent retrieval of episodes

PubMed Central

Hasselmo, Michael E.; Eichenbaum, Howard B.

2008-01-01

Behaviors ranging from delivering newspapers to waiting tables depend on remembering previous episodes to avoid incorrect repetition. Physiologically, this requires mechanisms for long-term storage and selective retrieval of episodes based on time of occurrence, despite variable intervals and similarity of events in a familiar environment. Here, this process has been modeled based on physiological properties of the hippocampal formation, including mechanisms for sustained activity in entorhinal cortex and theta rhythm oscillations in hippocampal subregions. The model simulates the context-sensitive firing properties of hippocampal neurons including trial specific firing during spatial alternation and trial by trial changes in theta phase precession on a linear track. This activity is used to guide behavior, and lesions of the hippocampal network impair memory-guided behavior. The model links data at the cellular level to behavior at the systems level, describing a physiologically plausible mechanism for the brain to recall a given episode which occurred at a specific place and time. PMID:16263240

Precooling treatments induce resistance of Anastrepha ludens eggs to quarantine treatments of high-pressure processing combined with cold.

PubMed

Castañón-Rodríguez, J F; Velazquez, G; Montoya, P; Vázquez, M; Ramírez, J A

2014-04-01

High-pressure processing (HPP) combined with heat or cold has been proposed as an alternative quarantine process for Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae). HPP conditions at levels higher than 100 MPa applied to destroy eggs and larvae can also affect the postharvest physiology of the fruits. HPP at pressure levels in the range of 50-100 MPa is recommended. Eggs have been reported as being more resistant to HPP than larvae. Therefore, the objective of this study was to assess the effect of a precooling treatment on the biological viability of A. ludens eggs treated by HPP at 0 degrees C. The capability of nondestroyed eggs to develop and reproduce was also evaluated. One-, 2-, 3-, and 4-d-old eggs were precooled in ice water for 0 (control) 3, 6, 12, or 24 h and then pressurized at 50, 70, or 90 MPa for 0, 3, 6, or 9 min at 0 degrees C. The hatching capability of pressurized eggs was evaluated. The most lethal effect of HPP on nonprecooled eggs (0 h) was obtained at 90 MPa for 9 min, destroying all eggs except for the 3-d-old ones, which showed an 11.8% hatch rate. Precooling treatment improved the hatch rate of eggs ranging from 4 to 50% depending on precooling conditions. The main effect was observed after 6 h. These results suggest that precooling modified the biochemistry and physiology of eggs, improving their resistance to HPP treatments.

68Ga-DOTA-TOC uptake in neuroendocrine tumour and healthy tissue: differentiation of physiological uptake and pathological processes in PET/CT.

PubMed

Kroiss, A; Putzer, D; Decristoforo, C; Uprimny, C; Warwitz, B; Nilica, B; Gabriel, M; Kendler, D; Waitz, D; Widmann, G; Virgolini, I J

2013-04-01

We wanted to establish the range of (68)Ga-DOTA-TOC uptake in liver and bone metastases of patients with neuroendocrine tumours (NET) and to establish the range of its uptake in pancreatic NET. This would allow differentiation between physiological uptake and tumour-related somatostatin receptor expression in the pancreas (including the uncinate process), liver and bone. Finally, we wanted to test for differences in patients with NET, either treated or not treated with peptide receptor radionuclide therapy (PRRT). In 249 patients, 390 (68)Ga-DOTA-TOC PET/CT studies were performed. The clinical indications for PET/CT were gastroenteropancreatic NET (194 studies), nongastroenteropancreatic NET (origin in the lung and rectum; 46 studies), NET of unknown primary (111 studies), phaeochromocytoma/glomus tumours (18 studies), and radioiodine-negative metastatic thyroid carcinoma (21 studies). SUVmax (mean ± standard deviation) values of (68)Ga-DOTA-TOC were 29.8 ± 16.5 in 162 liver metastases, 19.8 ± 18.8 in 89 bone metastases and 34.6 ± 17.1 in 43 pancreatic NET (33.6 ± 14.3 in 30 tumours of the uncinate process and 36.3 ± 21.5 in 13 tumours of the pancreatic tail). A significant difference in SUVmax (p < 0.02) was found in liver metastases of NET patients treated with PRRT. There were significant differences in SUVmax between nonmalignant and malignant tissue for both bone and liver metastases and for pancreatic NET including the uncinate process (p < 0.0001). At a cut-off value of 17.1 the specificity and sensitivity of SUVmax for differentiating tumours in the uncinate process were 93.6 % and 90.0 %, respectively (p < 0.0001). (68)Ga-DOTA-TOC is an excellent tracer for the imaging of tumours expressing somatostatin receptors on the tumour cell surface, facilitating the detection of even small tumour lesions. The noninvasive PET/CT approach by measurement of regional SUVmax can offer important clinical information to distinguish between physiological and pathological somatostatin receptor expression, especially in the uncinate process. PRRT does not significantly influence SUVmax, except in liver metastases of patients with NET.

Multimodal Regulation of Circadian Glucocorticoid Rhythm by Central and Adrenal Clocks.

PubMed

Son, Gi Hoon; Cha, Hyo Kyeong; Chung, Sooyoung; Kim, Kyungjin

2018-05-01

Adrenal glucocorticoids (GCs) control a wide range of physiological processes, including metabolism, cardiovascular and pulmonary activities, immune and inflammatory responses, and various brain functions. During stress responses, GCs are secreted through activation of the hypothalamic-pituitary-adrenal axis, whereas circulating GC levels in unstressed states follow a robust circadian oscillation with a peak around the onset of the active period of a day. A recent advance in chronobiological research has revealed that multiple regulatory mechanisms, along with classical neuroendocrine regulation, underlie this GC circadian rhythm. The hierarchically organized circadian system, with a central pacemaker in the suprachiasmatic nucleus of the hypothalamus and local oscillators in peripheral tissues, including the adrenal gland, mediates periodicities in physiological processes in mammals. In this review, we primarily focus on our understanding of the circadian regulation of adrenal GC rhythm, with particular attention to the cooperative actions of the suprachiasmatic nucleus central and adrenal local clocks, and the clinical implications of this rhythm in human diseases.

Multimodal Regulation of Circadian Glucocorticoid Rhythm by Central and Adrenal Clocks

PubMed Central

Son, Gi Hoon; Cha, Hyo Kyeong; Chung, Sooyoung; Kim, Kyungjin

2018-01-01

Abstract Adrenal glucocorticoids (GCs) control a wide range of physiological processes, including metabolism, cardiovascular and pulmonary activities, immune and inflammatory responses, and various brain functions. During stress responses, GCs are secreted through activation of the hypothalamic–pituitary–adrenal axis, whereas circulating GC levels in unstressed states follow a robust circadian oscillation with a peak around the onset of the active period of a day. A recent advance in chronobiological research has revealed that multiple regulatory mechanisms, along with classical neuroendocrine regulation, underlie this GC circadian rhythm. The hierarchically organized circadian system, with a central pacemaker in the suprachiasmatic nucleus of the hypothalamus and local oscillators in peripheral tissues, including the adrenal gland, mediates periodicities in physiological processes in mammals. In this review, we primarily focus on our understanding of the circadian regulation of adrenal GC rhythm, with particular attention to the cooperative actions of the suprachiasmatic nucleus central and adrenal local clocks, and the clinical implications of this rhythm in human diseases. PMID:29713692

High-speed AFM for scanning the architecture of living cells

NASA Astrophysics Data System (ADS)

Li, Jing; Deng, Zhifeng; Chen, Daixie; Ao, Zhuo; Sun, Quanmei; Feng, Jiantao; Yin, Bohua; Han, Li; Han, Dong

2013-08-01

We address the modelling of tip-cell membrane interactions under high speed atomic force microscopy. Using a home-made device with a scanning area of 100 × 100 μm2, in situ imaging of living cells is successfully performed under loading rates from 1 to 50 Hz, intending to enable detailed descriptions of physiological processes in living samples.We address the modelling of tip-cell membrane interactions under high speed atomic force microscopy. Using a home-made device with a scanning area of 100 × 100 μm2, in situ imaging of living cells is successfully performed under loading rates from 1 to 50 Hz, intending to enable detailed descriptions of physiological processes in living samples. Electronic supplementary information (ESI) available: Movie of the real-time change of inner surface within fresh blood vessel. The movie was captured at a speed of 30 Hz in the range of 80 μm × 80 μm. See DOI: 10.1039/c3nr01464a

Ways to be different: Foraging adaptations that facilitate higher intake rates in a northerly wintering shorebird compared with a low-latitude conspecific

USGS Publications Warehouse

Ruthrauff, Daniel R.; Dekinga, Anne; Gill, Robert E.; van Gils, Jan A.; Piersma, Theunis

2015-01-01

At what phenotypic level do closely related subspecies that live in different environments differ with respect to food detection, ingestion and processing? This question motivated an experimental study on rock sandpipers (Calidris ptilocnemis). The species' nonbreeding range spans 20 deg of latitude, the extremes of which are inhabited by two subspecies: C. p. ptilocnemis that winters primarily in upper Cook Inlet, Alaska (61°N) and C. p. tschuktschorum that overlaps slightly with C. p. ptilocnemis but whose range extends much farther south (∼40°N). In view of the strongly contrasting energetic demands of their distinct nonbreeding distributions, we conducted experiments to assess the behavioral, physiological and sensory aspects of foraging and we used the bivalve Macoma balthica for all trials. C. p. ptilocnemis consumed a wider range of prey sizes, had higher maximum rates of energy intake, processed shell waste at higher maximum rates and handled prey more quickly. Notably, however, the two subspecies did not differ in their abilities to find buried prey. The subspecies were similar in size and had equally sized gizzards, but the more northern ptilocnemis individuals were 10–14% heavier than their same-sex tschuktschorum counterparts. The higher body mass in ptilocnemis probably resulted from hypertrophy of digestive organs (e.g. intestine, liver) related to digestion and nutrient assimilation. Given the previously established equality of the metabolic capacities of the two subspecies, we propose that the high-latitude nonbreeding range of ptilocnemis rock sandpipers is primarily facilitated by digestive (i.e. physiological) aspects of their foraging ecology rather than behavioral or sensory aspects.

The micro and macro of nutrients across biological scales.

PubMed

Warne, Robin W

2014-11-01

During the past decade, we have gained new insights into the profound effects that essential micronutrients and macronutrients have on biological processes ranging from cellular function, to whole-organism performance, to dynamics in ecological communities, as well as to the structure and function of ecosystems. For example, disparities between intake and organismal requirements for specific nutrients are known to strongly affect animal physiological performance and impose trade-offs in the allocations of resources. However, recent findings have demonstrated that life-history allocation trade-offs and even microevolutionary dynamics may often be a result of molecular-level constraints on nutrient and metabolic processing, in which limiting reactants are routed among competing biochemical pathways. In addition, recent work has shown that complex ecological interactions between organismal physiological states such as exposure to environmental stressors and infectious pathogens can alter organismal requirements for, and, processing of, nutrients, and even alter subsequent nutrient cycling in ecosystems. Furthermore, new research is showing that such interactions, coupled with evolutionary and biogeographical constraints on the biosynthesis and availability of essential nutrients and micronutrients play an important, but still under-studied role in the structuring and functioning of ecosystems. The purpose of this introduction to the symposium "The Micro and Macro of Nutrient Effects in Animal Physiology and Ecology" is to briefly review and highlight recent research that has dramatically advanced our understanding of how nutrients in their varied forms profoundly affect and shape ecological and evolutionary processes. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

GLIS1-3 transcription factors: critical roles in the regulation of multiple physiological processes and diseases.

PubMed

Jetten, Anton M

2018-05-19

Krüppel-like zinc finger proteins form one of the largest families of transcription factors. They function as key regulators of embryonic development and a wide range of other physiological processes, and are implicated in a variety of pathologies. GLI-similar 1-3 (GLIS1-3) constitute a subfamily of Krüppel-like zinc finger proteins that act either as activators or repressors of gene transcription. GLIS3 plays a critical role in the regulation of multiple biological processes and is a key regulator of pancreatic β cell generation and maturation, insulin gene expression, thyroid hormone biosynthesis, spermatogenesis, and the maintenance of normal kidney functions. Loss of GLIS3 function in humans and mice leads to the development of several pathologies, including neonatal diabetes and congenital hypothyroidism, polycystic kidney disease, and infertility. Single nucleotide polymorphisms in GLIS3 genes have been associated with increased risk of several diseases, including type 1 and type 2 diabetes, glaucoma, and neurological disorders. GLIS2 plays a critical role in the kidney and GLIS2 dysfunction leads to nephronophthisis, an end-stage, cystic renal disease. In addition, GLIS1-3 have regulatory functions in several stem/progenitor cell populations. GLIS1 and GLIS3 greatly enhance reprogramming efficiency of somatic cells into induced embryonic stem cells, while GLIS2 inhibits reprogramming. Recent studies have obtained substantial mechanistic insights into several physiological processes regulated by GLIS2 and GLIS3, while a little is still known about the physiological functions of GLIS1. The localization of some GLIS proteins to the primary cilium suggests that their activity may be regulated by a downstream primary cilium-associated signaling pathway. Insights into the upstream GLIS signaling pathway may provide opportunities for the development of new therapeutic strategies for diabetes, hypothyroidism, and other diseases.

Two-photon fluorescent sensor for K+ imaging in live cells (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sui, Binglin; Yue, Xiling; Kim, Bosung; Belfield, Kevin D.

2016-03-01

It is difficult to overstate the physiological importance of potassium for life as its indispensable roles in a variety of biological processes are widely known. As a result, efficient methods for determining physiological levels of potassium are of paramount importance. Despite this, relatively few K+ fluorescence sensors have been reported, with only one being commercially available. A new two-photon excited fluorescent K+ sensor is reported. The sensor is comprised of three moieties, a highly selective K+ chelator as the K+ recognition unit, a boron-dipyrromethene (BODIPY) derivative modified with phenylethynyl groups as the fluorophore, and two polyethylene glycol chains to afford water solubility. The sensor displays very high selectivity (<52-fold) in detecting K+ over other physiological metal cations. Upon binding K+, the sensor switches from non-fluorescent to highly fluorescent, emitting red to near-IR (NIR) fluorescence. The sensor exhibited a good two-photon absorption cross section, 500 GM at 940 nm. Moreover, it is not sensitive to pH in the physiological pH range. Time-dependent cell imaging studies via both one- and two-photon fluorescence microscopy demonstrate that the sensor is suitable for dynamic K+ sensing in living cells.

Integrating multi-scale data to create a virtual physiological mouse heart.

PubMed

Land, Sander; Niederer, Steven A; Louch, William E; Sejersted, Ole M; Smith, Nicolas P

2013-04-06

While the virtual physiological human (VPH) project has made great advances in human modelling, many of the tools and insights developed as part of this initiative are also applicable for facilitating mechanistic understanding of the physiology of a range of other species. This process, in turn, has the potential to provide human relevant insights via a different scientific path. Specifically, the increasing use of mice in experimental research, not yet fully complemented by a similar increase in computational modelling, is currently missing an important opportunity for using and interpreting this growing body of experimental data to improve our understanding of cardiac function. This overview describes our work to address this issue by creating a virtual physiological mouse model of the heart. We describe the similarities between human- and mouse-focused modelling, including the reuse of VPH tools, and the development of methods for investigating parameter sensitivity that are applicable across species. We show how previous results using this approach have already provided important biological insights, and how these can also be used to advance VPH heart models. Finally, we show an example application of this approach to test competing multi-scale hypotheses by investigating variations in length-dependent properties of cardiac muscle.

Integrating multi-scale data to create a virtual physiological mouse heart

PubMed Central

Land, Sander; Niederer, Steven A.; Louch, William E.; Sejersted, Ole M.; Smith, Nicolas P.

2013-01-01

While the virtual physiological human (VPH) project has made great advances in human modelling, many of the tools and insights developed as part of this initiative are also applicable for facilitating mechanistic understanding of the physiology of a range of other species. This process, in turn, has the potential to provide human relevant insights via a different scientific path. Specifically, the increasing use of mice in experimental research, not yet fully complemented by a similar increase in computational modelling, is currently missing an important opportunity for using and interpreting this growing body of experimental data to improve our understanding of cardiac function. This overview describes our work to address this issue by creating a virtual physiological mouse model of the heart. We describe the similarities between human- and mouse-focused modelling, including the reuse of VPH tools, and the development of methods for investigating parameter sensitivity that are applicable across species. We show how previous results using this approach have already provided important biological insights, and how these can also be used to advance VPH heart models. Finally, we show an example application of this approach to test competing multi-scale hypotheses by investigating variations in length-dependent properties of cardiac muscle. PMID:24427525

Stress response physiology of thermophiles.

PubMed

Ranawat, Preeti; Rawat, Seema

2017-04-01

Thermo (or hyperthermo) philic microorganisms are ubiquitous having a wide range of habitats from freshly fallen snow to pasteurized milk to geothermal areas like hot springs. The variations in physicochemical conditions, viz., temperature, pH, nutrient availability and light intensity in the habitats always pose stress conditions for the inhabitants leading to slow growth or cell death. The industrial processes used for harvesting secondary metabolites such as enzymes, toxins and organic acids also create stressed environments for thermophiles. The production of DNA-binding proteins, activation of reactive oxygen species detoxification system, compatible solute accumulation, expression of heat shock proteins and alterations in morphology are a few examples of physiological changes demonstrated by these microscopic lifeforms in stress. These microorganisms exhibit complex genetic and physiological changes to minimize, adapt to and repair damage caused by extreme environmental disturbances. These changes are termed as 'stress responses' which enable them to stabilize their homeostasis. The exploration of important thermophilic factors would pave the way in engineering the microbial strains for various biotechnological applications. This review article presents a picture of physiological responses of thermophiles against various stress conditions as their mechanisms to respond to stress make them model organisms to further explore them for basic and applied biology purposes.

Zinc: physiology, deficiency, and parenteral nutrition.

PubMed

Livingstone, Callum

2015-06-01

The essential trace element zinc (Zn) has a large number of physiologic roles, in particular being required for growth and functioning of the immune system. Adaptive mechanisms enable the body to maintain normal total body Zn status over a wide range of intakes, but deficiency can occur because of reduced absorption or increased gastrointestinal losses. Deficiency impairs physiologic processes, leading to clinical consequences that include failure to thrive, skin rash, and impaired wound healing. Mild deficiency that is not clinically overt may still cause nonspecific consequences, such as susceptibility to infection and poor growth. The plasma Zn concentration has poor sensitivity and specificity as a test of deficiency. Consequently, diagnosis of deficiency requires a combination of clinical assessment and biochemical tests. Patients receiving parenteral nutrition (PN) are susceptible to Zn deficiency and its consequences. Nutrition support teams should have a strategy for assessing Zn status and optimizing this by appropriate supplementation. Nutrition guidelines recommend generous Zn provision from the start of PN. This review covers the physiology of Zn, the consequences of its deficiency, and the assessment of its status, before discussing its role in PN. © 2015 American Society for Parenteral and Enteral Nutrition.

Metal ion transport quantified by ICP-MS in intact cells

PubMed Central

Figueroa, Julio A. Landero; Stiner, Cory A.; Radzyukevich, Tatiana L.; Heiny, Judith A.

2016-01-01

The use of ICP-MS to measure metal ion content in biological tissues offers a highly sensitive means to study metal-dependent physiological processes. Here we describe the application of ICP-MS to measure membrane transport of Rb and K ions by the Na,K-ATPase in mouse skeletal muscles and human red blood cells. The ICP-MS method provides greater precision and statistical power than possible with conventional tracer flux methods. The method is widely applicable to studies of other metal ion transporters and metal-dependent processes in a range of cell types and conditions. PMID:26838181

Metal ion transport quantified by ICP-MS in intact cells.

PubMed

Figueroa, Julio A Landero; Stiner, Cory A; Radzyukevich, Tatiana L; Heiny, Judith A

2016-02-03

The use of ICP-MS to measure metal ion content in biological tissues offers a highly sensitive means to study metal-dependent physiological processes. Here we describe the application of ICP-MS to measure membrane transport of Rb and K ions by the Na,K-ATPase in mouse skeletal muscles and human red blood cells. The ICP-MS method provides greater precision and statistical power than possible with conventional tracer flux methods. The method is widely applicable to studies of other metal ion transporters and metal-dependent processes in a range of cell types and conditions.

A near infrared luminescent metal-organic framework for temperature sensing in the physiological range.

PubMed

Lian, Xiusheng; Zhao, Dian; Cui, Yuanjing; Yang, Yu; Qian, Guodong

2015-12-28

A near infrared pumped luminescent metal-organic framework thermometer Nd(0.577)Yb(0.423)BDC-F4, with near infrared fluorescence and excellent sensitivity in the physiological temperature range (293-313 K), has been first realized, and might be potentially applied for biomedical systems.

Light-evoked S-nitrosylation in the retina

PubMed Central

Tooker, Ryan E; Vigh, Jozsef

2015-01-01

Nitric oxide (NO) synthesis in the retina is triggered by light stimulation. NO has been shown to modulate visual signal processing at multiple sites in the vertebrate retina, via activation of the most sensitive target of NO signaling, soluble guanylate cyclase. NO can also alter protein structure and function and exert biological effects directly by binding to free thiol groups of cysteine residues in a chemical reaction called S-nitrosylation. However, in the central nervous system, including the retina, this reaction has not been considered to be significant under physiological conditions. Here we provide immunohistochemical evidence for extensive S-nitrosylation that takes place in the goldfish and mouse retinas under physiologically relevant light intensities, in an intensity-dependent manner, with a strikingly similar pattern in both species. Pre-treatment with NEM, which occludes S-nitrosylation, or with TRIM, an inhibitor of neuronal NO synthase, eliminated the light-evoked increase in S-nitrosylated protein immunofluorescence (SNI) in the retinas of both species. Similarly, light did not increase SNI, above basal levels, in retinas of transgenic mice lacking neuronal NO synthase. Qualitative analysis of the light-adapted mouse retina with mass spectrometry revealed more than 300 proteins that were S-nitrosylated upon illumination, many of which are known to participate directly in retinal signal processing. Our data strongly suggest that in the retina, light-evoked NO production leads to extensive S-nitrosylation and that this process is a significant post-translational modification affecting a wide range of proteins under physiological conditions. PMID:25823749

Infrared thermography: A non-invasive window into thermal physiology.

PubMed

Tattersall, Glenn J

2016-12-01

Infrared thermography is a non-invasive technique that measures mid to long-wave infrared radiation emanating from all objects and converts this to temperature. As an imaging technique, the value of modern infrared thermography is its ability to produce a digitized image or high speed video rendering a thermal map of the scene in false colour. Since temperature is an important environmental parameter influencing animal physiology and metabolic heat production an energetically expensive process, measuring temperature and energy exchange in animals is critical to understanding physiology, especially under field conditions. As a non-contact approach, infrared thermography provides a non-invasive complement to physiological data gathering. One caveat, however, is that only surface temperatures are measured, which guides much research to those thermal events occurring at the skin and insulating regions of the body. As an imaging technique, infrared thermal imaging is also subject to certain uncertainties that require physical modelling, which is typically done via built-in software approaches. Infrared thermal imaging has enabled different insights into the comparative physiology of phenomena ranging from thermogenesis, peripheral blood flow adjustments, evaporative cooling, and to respiratory physiology. In this review, I provide background and guidelines for the use of thermal imaging, primarily aimed at field physiologists and biologists interested in thermal biology. I also discuss some of the better known approaches and discoveries revealed from using thermal imaging with the objective of encouraging more quantitative assessment. Copyright © 2016 Elsevier Inc. All rights reserved.

Protein O-GlcNAcylation: emerging mechanisms and functions

PubMed Central

Yang, Xiaoyong; Qian, Kevin

2017-01-01

O-GlcNAcylation—the attachment of O-linked N-acetylglucosamine (O-GlcNAc) moieties to cytoplasmic, nuclear and mitochondrial proteins—is a post-translational modification that regulates fundamental cellular processes in metazoans. A single pair of enzymes—O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA)—controls the dynamic cycling of this post-translational modification in a nutrient- and stress-responsive manner. Recent years have seen remarkable advances in our understanding of O-GlcNAcylation at levels ranging from structural and molecular biology to cell signalling and gene regulation to physiology and disease. Emerging from these recent developments are new mechanisms and functions of O-GlcNAcylation that enable us to begin constructing a unified conceptual framework through which to understand the significance of this modification in cellular and organismal physiology. PMID:28488703

Identifying and quantifying main components of physiological noise in functional near infrared spectroscopy on the prefrontal cortex.

PubMed

Kirilina, Evgeniya; Yu, Na; Jelzow, Alexander; Wabnitz, Heidrun; Jacobs, Arthur M; Tachtsidis, Ilias

2013-01-01

Functional Near-Infrared Spectroscopy (fNIRS) is a promising method to study functional organization of the prefrontal cortex. However, in order to realize the high potential of fNIRS, effective discrimination between physiological noise originating from forehead skin haemodynamic and cerebral signals is required. Main sources of physiological noise are global and local blood flow regulation processes on multiple time scales. The goal of the present study was to identify the main physiological noise contributions in fNIRS forehead signals and to develop a method for physiological de-noising of fNIRS data. To achieve this goal we combined concurrent time-domain fNIRS and peripheral physiology recordings with wavelet coherence analysis (WCA). Depth selectivity was achieved by analyzing moments of photon time-of-flight distributions provided by time-domain fNIRS. Simultaneously, mean arterial blood pressure (MAP), heart rate (HR), and skin blood flow (SBF) on the forehead were recorded. WCA was employed to quantify the impact of physiological processes on fNIRS signals separately for different time scales. We identified three main processes contributing to physiological noise in fNIRS signals on the forehead. The first process with the period of about 3 s is induced by respiration. The second process is highly correlated with time lagged MAP and HR fluctuations with a period of about 10 s often referred as Mayer waves. The third process is local regulation of the facial SBF time locked to the task-evoked fNIRS signals. All processes affect oxygenated haemoglobin concentration more strongly than that of deoxygenated haemoglobin. Based on these results we developed a set of physiological regressors, which were used for physiological de-noising of fNIRS signals. Our results demonstrate that proposed de-noising method can significantly improve the sensitivity of fNIRS to cerebral signals.

A student-centered approach for developing active learning: the construction of physical models as a teaching tool in medical physiology.

PubMed

Rezende-Filho, Flávio Moura; da Fonseca, Lucas José Sá; Nunes-Souza, Valéria; Guedes, Glaucevane da Silva; Rabelo, Luiza Antas

2014-09-15

Teaching physiology, a complex and constantly evolving subject, is not a simple task. A considerable body of knowledge about cognitive processes and teaching and learning methods has accumulated over the years, helping teachers to determine the most efficient way to teach, and highlighting student's active participation as a means to improve learning outcomes. In this context, this paper describes and qualitatively analyzes an experience of a student-centered teaching-learning methodology based on the construction of physiological-physical models, focusing on their possible application in the practice of teaching physiology. After having Physiology classes and revising the literature, students, divided in small groups, built physiological-physical models predominantly using low-cost materials, for studying different topics in Physiology. Groups were followed by monitors and guided by teachers during the whole process, finally presenting the results in a Symposium on Integrative Physiology. Along the proposed activities, students were capable of efficiently creating physiological-physical models (118 in total) highly representative of different physiological processes. The implementation of the proposal indicated that students successfully achieved active learning and meaningful learning in Physiology while addressing multiple learning styles. The proposed method has proved to be an attractive, accessible and relatively simple approach to facilitate the physiology teaching-learning process, while facing difficulties imposed by recent requirements, especially those relating to the use of experimental animals and professional training guidelines. Finally, students' active participation in the production of knowledge may result in a holistic education, and possibly, better professional practices.

A Microbial Perspective on the Grand Challenges in Comparative Animal Physiology

PubMed Central

2018-01-01

ABSTRACT Interactions with microbial communities can have profound influences on animal physiology, thereby impacting animal performance and fitness. Therefore, it is important to understand the diversity and nature of host-microbe interactions in various animal groups (invertebrates, fish, amphibians, reptiles, birds, and mammals). In this perspective, I discuss how the field of host-microbe interactions can be used to address topics that have been identified as grand challenges in comparative animal physiology: (i) horizontal integration of physiological processes across organisms, (ii) vertical integration of physiological processes across organizational levels within organisms, and (iii) temporal integration of physiological processes during evolutionary change. Addressing these challenges will require the use of a variety of animal models and the development of systems approaches that can integrate large, multiomic data sets from both microbial communities and animal hosts. Integrating host-microbe interactions into the established field of comparative physiology represents an exciting frontier for both fields. PMID:29556549

RNA-sequencing elucidates the regulation of behavioural transitions associated with the mating process in honey bee queens.

PubMed

Manfredini, Fabio; Brown, Mark J F; Vergoz, Vanina; Oldroyd, Benjamin P

2015-07-31

Mating is a complex process, which is frequently associated with behavioural and physiological changes. However, understanding of the genetic underpinnings of these changes is limited. Honey bees are both a model system in behavioural genomics, and the dominant managed pollinator of human crops; consequently understanding the mating process has both pure and applied value. We used next-generation transcriptomics to probe changes in gene expression in the brains of honey bee queens, as they transition from virgin to mated reproductive status. In addition, we used CO2-narcosis, which induces oviposition without mating, to isolate the process of reproductive maturation. The mating process produced significant changes in the expression of vision, chemo-reception, metabolic, and immune-related genes. Differential expression of these genes maps clearly onto known behavioural and physiological changes that occur during the transition from being a virgin queen to a newly-mated queen. A subset of these changes in gene expression were also detected in CO2-treated queens, as predicted from previous physiological studies. In addition, we compared our results to previous studies that used microarray techniques across a range of experimental time-points. Changes in expression of immune- and vision-related genes were common to all studies, supporting an involvement of these groups of genes in the mating process. Our study is an important step in understanding the molecular mechanisms regulating post-mating behavioural transitions in a natural system. The weak overlap in patterns of gene expression with previous studies demonstrates the high sensitivity of genome-wide approaches. Thus, while we build on previous microarray studies that explored post-mating changes in honey bees, the broader experimental design, use of RNA-sequencing, and focus on Australian honey bees, which remain free from the devastating parasite Varroa destructor, in the current study, provide unique insights into the biology of the mating process in honey bees.

A physiological perspective on the neuroscience of eating.

PubMed

Geary, Nori

2014-09-01

I present the thesis that 'being physiological,' i.e., analyzing eating under conditions that do not perturb, or minimally perturb, the organism's endogenous processes, should be a central goal of the neuroscience of eating. I describe my understanding of 'being physiological' based on [i] the central neural-network heuristic of CNS function that traces back to Cajal and Sherrington, [ii] research on one of the simpler problems in the neuroscience of eating, identification of endocrine signals that control eating. In this context I consider natural meals, physiological doses and ranges, and antagonist studies. Several examples involve CCK. Next I describe my view of the cutting edge in the molecular neuroscience of eating as it has evolved from the discovery of leptin signaling through the application of optogenetic and pharmacogenetic methods. Finally I describe some novel approaches that may advance the neuroscience of eating in the foreseeable future. I conclude that [i] the neuroscience of eating may soon be able to discern 'physiological' function in the operation of CNS networks mediating eating, [ii] the neuroscience of eating should capitalize on methods developed in other areas of neuroscience, e.g., improved methods to record and manipulate CNS function in behaving animals, identification of canonical regional circuits, use of population electrophysiology, etc., and [iii] subjective aspects of eating are crucial aspects of eating science, but remain beyond mechanistic understanding. Copyright © 2014 Elsevier Inc. All rights reserved.

Histolocalization and physico-chemical characterization of dihydrochalcones: Insight into the role of apple major flavonoids.

PubMed

Gaucher, Matthieu; Dugé de Bernonville, Thomas; Lohou, David; Guyot, Sylvain; Guillemette, Thomas; Brisset, Marie-Noëlle; Dat, James F

2013-06-01

Flavonoids, like other metabolites synthesized via the phenylpropanoid pathway, possess a wide range of biological activities including functions in plant development and its interaction with the environment. Dihydrochalcones (mainly phloridzin, sieboldin, trilobatin, phloretin) represent the major flavonoid subgroup in apple green tissues. Although this class of phenolic compounds is found in very large amounts in some tissues (≈200mg/g of leaf DW), their physiological significance remains unclear. In the present study, we highlight their tissue-specific localization in young growing shoots suggesting a specific role in important physiological processes, most notably in response to biotic stress. Indeed, dihydrochalcones could constitute a basal defense, in particular phloretin which exhibits a strong broad-range bactericidal and fungicidal activity. Our results also indicate that sieboldin forms complexes with iron with strong affinity, reinforcing its antioxidant properties and conferring to this dihydrochalcone a potential for iron seclusion and/or storage. The importance of localization and biochemical properties of dihydrochalcones are discussed in view of the apple tree defense strategy against both biotic and abiotic stresses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of humic acids on the metabolism of Chlorella vulgaris in a model experiment

NASA Astrophysics Data System (ADS)

Toropkina, M. A.; Ryumin, A. G.; Kechaikina, I. O.; Chukov, S. N.

2017-11-01

The effect of humic acids (HAs) on physiological processes (photosynthesis, respiration, and abundance) of green microalga Chlorella vulgaris has been studied, and the relationships between the physiological activity of HAs and their structural parameters have been investigated. It has been found that the optimum range of HA concentrations for the growth of C. vulgaris is 0.01-0.03%. In this range, the highest positive effect on total photosynthesis increment is due to hydrophilic HA preparations from fallow soddypodzolic soil (Albic Retisol) and virgin gray soil (Luvic Greyzemic Phaeozem). The minimum stimulation of respiration is noted for all HA preparations in the region of the maximum photosynthesis stimulation. At concentrations above 0.003%, all HA preparations have a negative effect: the rate of photosynthesis in C. vulgaris cells decreases, and their respiration is strongly enhanced. The abundance of C. vulgaris under the effect of all of the studied preparations under illumination increases more rapidly than in the dark. A high positive coefficient of correlation is found between the hydrophilicity of HAs calculated from 13C NMR data and the photosynthesis rate in C. vulgaris.

Hot and Bothered: Changes in Microclimate Alter Chlorophyll Fluorescence Measures and Increase Stress Levels in Tropical Epiphytic Orchids

Treesearch

Benjamin J. Crain; Raymond L. Tremblay

2017-01-01

Premise of research. Tropical epiphytes are susceptible to climatic changes, as evidenced by documented population declines, range contractions, and range shifts; however, physiological changes in individual plants may also be indicative of deteriorating climate conditions. Consequently, physiological analyses of tropical epiphytes whose natural habitats are...

Measurement of Physiologic Glucose Levels Using Raman Spectroscopy in a Rabbit Aqueous Humor Model

NASA Technical Reports Server (NTRS)

Lambert, J.; Storrie-Lombardi, M.; Borchert, M.

1998-01-01

We have elecited a reliable glucose signature in mammalian physiological ranges using near infrared Raman laser excitation at 785 nm and multivariate analysis. In a recent series of experiments we measured glucose levels in an artificial aqueous humor in the range from 0.5 to 13X normal values.

Sensitivity of Physiological Emotional Measures to Odors Depends on the Product and the Pleasantness Ranges Used

PubMed Central

Pichon, Aline M.; Coppin, Géraldine; Cayeux, Isabelle; Porcherot, Christelle; Sander, David; Delplanque, Sylvain

2015-01-01

Emotions are characterized by synchronized changes in several components of an organism. Among them, physiological variations provide energy support for the expression of approach/avoid action tendencies induced by relevant stimuli, while self-reported subjective pleasantness feelings integrate all other emotional components and are plastic. Consequently, emotional responses evoked by odors should be highly differentiated when they are linked to different functions of olfaction (e.g., avoiding environmental hazards). As this differentiation has been observed for contrasted odors (very pleasant or unpleasant), we questioned whether subjective and physiological emotional response indicators could still disentangle subtle affective variations when no clear functional distinction is made (mildly pleasant or unpleasant fragrances). Here, we compared the sensitivity of behavioral and physiological [respiration, skin conductance, facial electromyography (EMG), and heart rate] indicators in differentiating odor-elicited emotions in two situations: when a wide range of odor families was presented (e.g., fruity, animal), covering different functional meanings; or in response to a restricted range of products in one particular family (fragrances). Results show clear differences in physiological indicators to odors that display a wide range of reported pleasantness, but these differences almost entirely vanish when fragrances are used even though their subjective pleasantness still differed. Taken together, these results provide valuable information concerning the ability of classic verbal and psychophysiological measures to investigate subtle differences in emotional reactions to a restricted range of similar olfactory stimuli. PMID:26648888

An Approximation to the Adaptive Exponential Integrate-and-Fire Neuron Model Allows Fast and Predictive Fitting to Physiological Data.

PubMed

Hertäg, Loreen; Hass, Joachim; Golovko, Tatiana; Durstewitz, Daniel

2012-01-01

For large-scale network simulations, it is often desirable to have computationally tractable, yet in a defined sense still physiologically valid neuron models. In particular, these models should be able to reproduce physiological measurements, ideally in a predictive sense, and under different input regimes in which neurons may operate in vivo. Here we present an approach to parameter estimation for a simple spiking neuron model mainly based on standard f-I curves obtained from in vitro recordings. Such recordings are routinely obtained in standard protocols and assess a neuron's response under a wide range of mean-input currents. Our fitting procedure makes use of closed-form expressions for the firing rate derived from an approximation to the adaptive exponential integrate-and-fire (AdEx) model. The resulting fitting process is simple and about two orders of magnitude faster compared to methods based on numerical integration of the differential equations. We probe this method on different cell types recorded from rodent prefrontal cortex. After fitting to the f-I current-clamp data, the model cells are tested on completely different sets of recordings obtained by fluctuating ("in vivo-like") input currents. For a wide range of different input regimes, cell types, and cortical layers, the model could predict spike times on these test traces quite accurately within the bounds of physiological reliability, although no information from these distinct test sets was used for model fitting. Further analyses delineated some of the empirical factors constraining model fitting and the model's generalization performance. An even simpler adaptive LIF neuron was also examined in this context. Hence, we have developed a "high-throughput" model fitting procedure which is simple and fast, with good prediction performance, and which relies only on firing rate information and standard physiological data widely and easily available.

The Bottlenose Dolphin (Tursiops truncatus) as a Model to Understand Variation in Stress and Reproductive Hormone Measures in Relation to Sampling Matrix, Demographics, and Environmental Factors

DTIC Science & Technology

2015-09-30

ranging individuals support the existence of these same stress response pathways in marine mammals. 2 While the HPA axis and physiological processes...relying upon methods which include capture-release health assessments. Stress and reproductive hormones (cortisol, aldosterone , thyroid, testosterone...Analyses Hormone concentrations (cortisol, aldosterone , reproductive and thyroid hormones) in serum samples were analyzed by Cornell’s Animal Health

Impact of Diurnal Temperature Fluctuations during Larval Development on Adult Life History Traits and Insecticide Susceptibility in Two Vectors; Anopheles gambiae and Aedes aegypti

DTIC Science & Technology

2014-04-30

105 x CHAPTER 1: General Introduction THE THERMAL ENVIRONMENT The ambient temperature at which an organism must function can...forces an organism to operate outside the optimal temperature range for which its physiological processes are optimized to function under. Thermal...a specific insecticide. Some of these influences are relatively intuitive. For instance, larval development in the presence of adequate nutritional

The big and intricate dreams of little organelles: Embracing complexity in the study of membrane traffic.

PubMed

Liu, Allen P; Botelho, Roberto J; Antonescu, Costin N

2017-09-01

Compartmentalization of eukaryotic cells into dynamic organelles that exchange material through regulated membrane traffic governs virtually every aspect of cellular physiology including signal transduction, metabolism and transcription. Much has been revealed about the molecular mechanisms that control organelle dynamics and membrane traffic and how these processes are regulated by metabolic, physical and chemical cues. From this emerges the understanding of the integration of specific organellar phenomena within complex, multiscale and nonlinear regulatory networks. In this review, we discuss systematic approaches that revealed remarkable insight into the complexity of these phenomena, including the use of proximity-based proteomics, high-throughput imaging, transcriptomics and computational modeling. We discuss how these methods offer insights to further understand molecular versatility and organelle heterogeneity, phenomena that allow a single organelle population to serve a range of physiological functions. We also detail on how transcriptional circuits drive organelle adaptation, such that organelles may shift their function to better serve distinct differentiation and stress conditions. Thus, organelle dynamics and membrane traffic are functionally heterogeneous and adaptable processes that coordinate with higher-order system behavior to optimize cell function under a range of contexts. Obtaining a comprehensive understanding of organellar phenomena will increasingly require combined use of reductionist and system-based approaches. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Identification, Expression and IAA-Amide Synthetase Activity Analysis of Gretchen Hagen 3 in Papaya Fruit (Carica papaya L.) during Postharvest Process

PubMed Central

Liu, Kaidong; Wang, Jinxiang; Li, Haili; Zhong, Jundi; Feng, Shaoxian; Pan, Yaoliang; Yuan, Changchun

2016-01-01

Auxin plays essential roles in plant development. Gretchen Hagen 3 (GH3) genes belong to a major auxin response gene family and GH3 proteins conjugate a range of acylsubstrates to alter the levels of hormones. Currently, the role of GH3 genes in postharvest physiological regulation of ripening and softening processes in papaya fruit is unclear. In this study, we identified seven CpGH3 genes in a papaya genome database. The CpGH3.1a, CpGH3.1b, CpGH3.5, CpGH3.6, and CpGH3.9 proteins were identified as indole-3-acetic acid (IAA)-specific amido synthetases. We analyzed the changes in IAA-amido synthetase activity using aspartate as a substrate for conjugation and found a large increase (over 5-fold) during the postharvest stages. Ascorbic acid (AsA) application can extend the shelf life of papaya fruit. Our data showed that AsA treatment regulates postharvest fruit maturation processes by promoting endogenous IAA levels. Our findings demonstrate the important role of GH3 genes in the regulation of auxin-associated postharvest physiology in papaya. PMID:27812360

Using energy budgets to combine ecology and toxicology in a mammalian sentinel species

NASA Astrophysics Data System (ADS)

Desforges, Jean-Pierre W.; Sonne, Christian; Dietz, Rune

2017-04-01

Process-driven modelling approaches can resolve many of the shortcomings of traditional descriptive and non-mechanistic toxicology. We developed a simple dynamic energy budget (DEB) model for the mink (Mustela vison), a sentinel species in mammalian toxicology, which coupled animal physiology, ecology and toxicology, in order to mechanistically investigate the accumulation and adverse effects of lifelong dietary exposure to persistent environmental toxicants, most notably polychlorinated biphenyls (PCBs). Our novel mammalian DEB model accurately predicted, based on energy allocations to the interconnected metabolic processes of growth, development, maintenance and reproduction, lifelong patterns in mink growth, reproductive performance and dietary accumulation of PCBs as reported in the literature. Our model results were consistent with empirical data from captive and free-ranging studies in mink and other wildlife and suggest that PCB exposure can have significant population-level impacts resulting from targeted effects on fetal toxicity, kit mortality and growth and development. Our approach provides a simple and cross-species framework to explore the mechanistic interactions of physiological processes and ecotoxicology, thus allowing for a deeper understanding and interpretation of stressor-induced adverse effects at all levels of biological organization.

Understanding auditory distance estimation by humpback whales: a computational approach.

PubMed

Mercado, E; Green, S R; Schneider, J N

2008-02-01

Ranging, the ability to judge the distance to a sound source, depends on the presence of predictable patterns of attenuation. We measured long-range sound propagation in coastal waters to assess whether humpback whales might use frequency degradation cues to range singing whales. Two types of neural networks, a multi-layer and a single-layer perceptron, were trained to classify recorded sounds by distance traveled based on their frequency content. The multi-layer network successfully classified received sounds, demonstrating that the distorting effects of underwater propagation on frequency content provide sufficient cues to estimate source distance. Normalizing received sounds with respect to ambient noise levels increased the accuracy of distance estimates by single-layer perceptrons, indicating that familiarity with background noise can potentially improve a listening whale's ability to range. To assess whether frequency patterns predictive of source distance were likely to be perceived by whales, recordings were pre-processed using a computational model of the humpback whale's peripheral auditory system. Although signals processed with this model contained less information than the original recordings, neural networks trained with these physiologically based representations estimated source distance more accurately, suggesting that listening whales should be able to range singers using distance-dependent changes in frequency content.

Spectral convergence in tapping and physiological fluctuations: coupling and independence of 1/f noise in the central and autonomic nervous systems

PubMed Central

Rigoli, Lillian M.; Holman, Daniel; Spivey, Michael J.; Kello, Christopher T.

2014-01-01

When humans perform a response task or timing task repeatedly, fluctuations in measures of timing from one action to the next exhibit long-range correlations known as 1/f noise. The origins of 1/f noise in timing have been debated for over 20 years, with one common explanation serving as a default: humans are composed of physiological processes throughout the brain and body that operate over a wide range of timescales, and these processes combine to be expressed as a general source of 1/f noise. To test this explanation, the present study investigated the coupling vs. independence of 1/f noise in timing deviations, key-press durations, pupil dilations, and heartbeat intervals while tapping to an audiovisual metronome. All four dependent measures exhibited clear 1/f noise, regardless of whether tapping was synchronized or syncopated. 1/f spectra for timing deviations were found to match those for key-press durations on an individual basis, and 1/f spectra for pupil dilations matched those in heartbeat intervals. Results indicate a complex, multiscale relationship among 1/f noises arising from common sources, such as those arising from timing functions vs. those arising from autonomic nervous system (ANS) functions. Results also provide further evidence against the default hypothesis that 1/f noise in human timing is just the additive combination of processes throughout the brain and body. Our findings are better accommodated by theories of complexity matching that begin to formalize multiscale coordination as a foundation of human behavior. PMID:25309389

Physiology and growth of redwood and Douglas-fir planted after variable density retention outside redwood’s range

Treesearch

Lucy Kerhoulas; Nicholas Kerhoulas; Wade Polda; John-Pascal Berrill

2017-01-01

Reforestation following timber harvests is an important topic throughout the coast redwood (Sequoia sempervirens (D. Don) Endl.) range. Furthermore, as drought-induced mortality spreads across many of California’s forests, it is important to understand how physiology and stand structure influence reforestation success. Finally, as climate...

Evaluating the Significance of Paleophylogeographic Species Distribution Models in Reconstructing Quaternary Range-Shifts of Nearctic Chelonians

PubMed Central

Flecks, Morris; Ahmadzadeh, Faraham; Dambach, Johannes; Engler, Jan O.; Habel, Jan Christian; Hartmann, Timo; Hörnes, David; Ihlow, Flora; Schidelko, Kathrin; Stiels, Darius; Polly, P. David

2013-01-01

The climatic cycles of the Quaternary, during which global mean annual temperatures have regularly changed by 5–10°C, provide a special opportunity for studying the rate, magnitude, and effects of geographic responses to changing climates. During the Quaternary, high- and mid-latitude species were extirpated from regions that were covered by ice or otherwise became unsuitable, persisting in refugial retreats where the environment was compatible with their tolerances. In this study we combine modern geographic range data, phylogeny, Pleistocene paleoclimatic models, and isotopic records of changes in global mean annual temperature, to produce a temporally continuous model of geographic changes in potential habitat for 59 species of North American turtles over the past 320 Ka (three full glacial-interglacial cycles). These paleophylogeographic models indicate the areas where past climates were compatible with the modern ranges of the species and serve as hypotheses for how their geographic ranges would have changed in response to Quaternary climate cycles. We test these hypotheses against physiological, genetic, taxonomic and fossil evidence, and we then use them to measure the effects of Quaternary climate cycles on species distributions. Patterns of range expansion, contraction, and fragmentation in the models are strongly congruent with (i) phylogeographic differentiation; (ii) morphological variation; (iii) physiological tolerances; and (iv) intraspecific genetic variability. Modern species with significant interspecific differentiation have geographic ranges that strongly fluctuated and repeatedly fragmented throughout the Quaternary. Modern species with low genetic diversity have geographic distributions that were highly variable and at times exceedingly small in the past. Our results reveal the potential for paleophylogeographic models to (i) reconstruct past geographic range modifications, (ii) identify geographic processes that result in genetic bottlenecks; and (iii) predict threats due to anthropogenic climate change in the future. PMID:24130664

Normal male sexual function: emphasis on orgasm and ejaculation

PubMed Central

Alwaal, Amjad; Breyer, Benjamin N.; Lue, Tom F.

2016-01-01

Orgasm and ejaculation are two separate physiological processes that are sometimes difficult to distinguish. Orgasm is an intense transient peak sensation of intense pleasure creating an altered state of consciousness associated with reported physical changes. Antegrade ejaculation is a complex physiological process that is composed of two phases (emission and expulsion), and is influenced by intricate neurological and hormonal pathways. Despite the many published research projects dealing with the physiology of orgasm and ejaculation, much about this topic is still unknown. Ejaculatory dysfunction is a common disorder, and currently has no definitive cure. Understanding the complex physiology of orgasm and ejaculation allows the development of therapeutic targets for ejaculatory dysfunction. In this article, we summarize the current literature on the physiology of orgasm and ejaculation, starting with a brief description of the anatomy of sex organs and the physiology of erection. Then, we describe the physiology of orgasm and ejaculation detailing the neuronal, neurochemical, and hormonal control of the ejaculation process. PMID:26385403

Fractal Physiology and the Fractional Calculus: A Perspective

PubMed Central

West, Bruce J.

2010-01-01

This paper presents a restricted overview of Fractal Physiology focusing on the complexity of the human body and the characterization of that complexity through fractal measures and their dynamics, with fractal dynamics being described by the fractional calculus. Not only are anatomical structures (Grizzi and Chiriva-Internati, 2005), such as the convoluted surface of the brain, the lining of the bowel, neural networks and placenta, fractal, but the output of dynamical physiologic networks are fractal as well (Bassingthwaighte et al., 1994). The time series for the inter-beat intervals of the heart, inter-breath intervals and inter-stride intervals have all been shown to be fractal and/or multifractal statistical phenomena. Consequently, the fractal dimension turns out to be a significantly better indicator of organismic functions in health and disease than the traditional average measures, such as heart rate, breathing rate, and stride rate. The observation that human physiology is primarily fractal was first made in the 1980s, based on the analysis of a limited number of datasets. We review some of these phenomena herein by applying an allometric aggregation approach to the processing of physiologic time series. This straight forward method establishes the scaling behavior of complex physiologic networks and some dynamic models capable of generating such scaling are reviewed. These models include simple and fractional random walks, which describe how the scaling of correlation functions and probability densities are related to time series data. Subsequently, it is suggested that a proper methodology for describing the dynamics of fractal time series may well be the fractional calculus, either through the fractional Langevin equation or the fractional diffusion equation. A fractional operator (derivative or integral) acting on a fractal function, yields another fractal function, allowing us to construct a fractional Langevin equation to describe the evolution of a fractal statistical process. Control of physiologic complexity is one of the goals of medicine, in particular, understanding and controlling physiological networks in order to ensure their proper operation. We emphasize the difference between homeostatic and allometric control mechanisms. Homeostatic control has a negative feedback character, which is both local and rapid. Allometric control, on the other hand, is a relatively new concept that takes into account long-time memory, correlations that are inverse power law in time, as well as long-range interactions in complex phenomena as manifest by inverse power-law distributions in the network variable. We hypothesize that allometric control maintains the fractal character of erratic physiologic time series to enhance the robustness of physiological networks. Moreover, allometric control can often be described using the fractional calculus to capture the dynamics of complex physiologic networks. PMID:21423355

Physiological studies of the brain: Implications for science teaching

NASA Astrophysics Data System (ADS)

Esler, William K.

Physiological changes resulting from repeated, long-term stimulation have been observed in the brains of both humans and laboratory animals. It may be speculated that these changes are related to short-term and long-term memory processes. A physiologically based model for memory processing (PBMMP) can serve to explain the interrelations of various areas of the brain as they process new stimuli and recall past events. The model can also serve to explain many current principles of learning theory and serve as a foundation for developing new theories of learning based upon the physiology of the brain.

Arachidonic-acid-derived eicosanoids: roles in biology and immunopathology.

PubMed

Harizi, Hedi; Corcuff, Jean-Benoît; Gualde, Norbert

2008-10-01

Arachidonic acid (AA)-derived eicosanoids belong to a complex family of lipid mediators that regulate a wide variety of physiological responses and pathological processes. They are produced by various cell types through distinct enzymatic pathways and act on target cells via specific G-protein-coupled receptors. Although originally recognized for their capacity to elicit biological responses such as vascular homeostasis, protection of the gastric mucosa and platelet aggregation, eicosanoids are now understood to regulate immunopathological processes ranging from inflammatory responses to chronic tissue remodelling, cancer, asthma, rheumatoid arthritis and autoimmune disorders. Here, we review the major properties of eicosanoids and their expanding roles in biology and medicine.

Salinity and High Temperature Tolerance in Mungbean [Vigna radiata (L.) Wilczek] from a Physiological Perspective

PubMed Central

HanumanthaRao, Bindumadhava; Nair, Ramakrishnan M.; Nayyar, Harsh

2016-01-01

Biotic and abiotic constraints seriously affect the productivity of agriculture worldwide. The broadly recognized benefits of legumes in cropping systems—biological nitrogen fixation, improving soil fertility and broadening cereal-based agro-ecologies, are desirable now more than ever. Legume production is affected by hostile environments, especially soil salinity and high temperatures (HTs). Among legumes, mungbean has acceptable intrinsic tolerance mechanisms, but many agro-physiological characteristics of the Vigna species remain to be explored. Mungbean has a distinct advantage of being short-duration and can grow in wide range of soils and environments (as mono or relay legume). This review focuses on salinity and HT stresses on mungbean grown as a fallow crop (mungbean-rice-wheat to replace fallow-rice-wheat) and/or a relay crop in cereal cropping systems. Salinity tolerance comprises multifaceted responses at the molecular, physiological and plant canopy levels. In HTs, adaptation of physiological and biochemical processes gradually may lead to improvement of heat tolerance in plants. At the field level, managing or manipulating cultural practices can mitigate adverse effects of salinity and HT. Greater understanding of physiological and biochemical mechanisms regulating these two stresses will contribute to an evolving profile of the genes, proteins, and metabolites responsible for mungbean survival. We focus on abiotic stresses in legumes in general and mungbean in particular, and highlight gaps that need to be bridged through future mungbean research. Recent findings largely from physiological and biochemical fronts are examined, along with a few agronomic and farm-based management strategies to mitigate stress under field conditions. PMID:27446183

The paranasal sinuses: the last frontier in craniofacial biology.

PubMed

Márquez, Samuel

2008-11-01

This special issue of the Anatomical Record explores the presence and diversity of paranasal sinuses in distinct vertebrate groups. The following topics are addressed in particular: dinosaur physiology; development; physiology; adaptation; imaging; and primate systematics. A variety of approaches and techniques are used to examine and characterize the diversity of paranasal sinus pneumatization in a wide spectrum of vertebrates. These range from dissection to histology, from plain X-rays to computer tomography, from comparative anatomy to natural experimental settings, from mathematical computation to computer model simulation, and 2D to 3D reconstructions. The articles in this issue are a combination of literature review and new, hypothesis-driven anatomical research that highlights the complexities of paranasal sinus growth and development; ontogenetic and disease processes; physiology; paleontology; primate systematics; and human evolution. The issue incorporates a wide variety of vertebrates, encompassing a period of over 65 million years, in an effort to offer insight into the diversity of the paranasal sinus complexes through time and space, and thereby providing a greater understanding and appreciation of these special spaces within the cranium. Copyright 2008 Wiley-Liss, Inc.

Brassinosteroids

PubMed Central

Clouse, Steven D.

2011-01-01

Brassinosteroids (BRs) are endogenous plant hormones essential for the proper regulation of multiple physiological processes required for normal plant growth and development. Since their discovery more than 30 years ago, extensive research on the mechanisms of BR action using biochemistry, mutant studies, proteomics and genome-wide transcriptome analyses, has helped refine the BR biosynthetic pathway, identify the basic molecular components required to relay the BR signal from perception to gene regulation, and expand the known physiological responses influenced by BRs. These mechanistic advances have helped answer the intriguing question of how BRs can have such dramatic pleiotropic effects on a broad range of diverse developmental pathways and have further pointed to BR interactions with other plant hormones and environmental cues. This chapter briefly reviews historical aspects of BR research and then summarizes the current state of knowledge on BR biosynthesis, metabolism and signal transduction. Recent studies uncovering novel phosphorelays and gene regulatory networks through which BR influences both vegetative and reproductive development are examined and placed in the context of known BR physiological responses including cell elongation and division, vascular differentiation, flowering, pollen development and photomorphogenesis. PMID:22303275

The Role of Ambulatory Assessment in Psychological Science.

PubMed

Trull, Timothy J; Ebner-Priemer, Ulrich

2014-12-01

We describe the current use and future promise of an innovative methodology, ambulatory assessment (AA), that can be used to investigate psychological, emotional, behavioral, and biological processes of individuals in their daily life. The term AA encompasses a wide range of methods used to study people in their natural environment, including momentary self-report, observational, and physiological. We emphasize applications of AA that integrate two or more of these methods, discuss the smart phone as a hub or access point for AA, and discuss future applications of AA methodology to the science of psychology. We pay particular attention to the development and application of Wireless Body Area Networks (WBANs) that can be implemented with smart phones and wireless physiological monitoring devices, and we close by discussing future applications of this approach to matters relevant to psychological science.

Aloe vera: a valuable ingredient for the food, pharmaceutical and cosmetic industries--a review.

PubMed

Eshun, Kojo; He, Qian

2004-01-01

Scientific investigations on Aloe vera have gained more attention over the last several decades due to its reputable medicinal properties. Some publications have appeared in reputable Scientific Journals that have made appreciable contributions to the discovery of the functions and utilizations of Aloe--"nature's gift." Chemical analysis reveals that Aloe vera contains various carbohydrate polymers, notably glucomannans, along with a range of other organic and inorganic components. Although many physiological properties of Aloe vera have been described, it still remains uncertain as to which of the component(s) is responsible for these physiological properties. Further research needs to be done to unravel the myth surrounding the biological activities and the functional properties of A. vera. Appropriate processing techniques should be employed during the stabilization of the gel in order to affect and extend its field of utilization.

Physiology, ecology and industrial applications of aroma formation in yeast

PubMed Central

Dzialo, Maria C; Park, Rahel; Steensels, Jan; Lievens, Bart; Verstrepen, Kevin J

2017-01-01

Abstract Yeast cells are often employed in industrial fermentation processes for their ability to efficiently convert relatively high concentrations of sugars into ethanol and carbon dioxide. Additionally, fermenting yeast cells produce a wide range of other compounds, including various higher alcohols, carbonyl compounds, phenolic compounds, fatty acid derivatives and sulfur compounds. Interestingly, many of these secondary metabolites are volatile and have pungent aromas that are often vital for product quality. In this review, we summarize the different biochemical pathways underlying aroma production in yeast as well as the relevance of these compounds for industrial applications and the factors that influence their production during fermentation. Additionally, we discuss the different physiological and ecological roles of aroma-active metabolites, including recent findings that point at their role as signaling molecules and attractants for insect vectors. PMID:28830094

Experience Modulates the Reproductive Response to Heat Stress in C. elegans via Multiple Physiological Processes

PubMed Central

Gouvêa, Devin Y.; Aprison, Erin Z.; Ruvinsky, Ilya

2015-01-01

Natural environments are considerably more variable than laboratory settings and often involve transient exposure to stressful conditions. To fully understand how organisms have evolved to respond to any given stress, prior experience must therefore be considered. We investigated the effects of individual and ancestral experience on C. elegans reproduction. We documented ways in which cultivation at 15°C or 25°C affects developmental time, lifetime fecundity, and reproductive performance after severe heat stress that exceeds the fertile range of the organism but is compatible with survival and future fecundity. We found that experience modulates multiple aspects of reproductive physiology, including the male and female germ lines and the interaction between them. These responses vary in their environmental sensitivity, suggesting the existence of complex mechanisms for coping with unpredictable and stressful environments. PMID:26713620

Aging and magnetism: Presenting a possible new holistic paradigm for ameliorating the aging process and the effects thereof, through externally applied physiologic PicoTesla magnetic fields.

PubMed

Jacobson, Jerry; Sherlag, Benjamin

2015-09-01

A new holistic paradigm is proposed for slowing our genomic-based biological clocks (e.g. regulation of telomere length), and decreasing heat energy exigencies for maintenance of physiologic homeostasis. Aging is considered the result of a progressive slow burn in small volumes of tissues with increase in the quantum entropic states; producing desiccation, microscopic scarring, and disruption of cooperative coherent states. Based upon piezoelectricity, i.e. photon-phonon transductions, physiologic PicoTesla range magnetic fields may decrease the production of excessive heat energy through target specific, bio molecular resonant interactions, renormalization of intrinsic electromagnetic tissue profiles, and autonomic modulation. Prospectively, we hypothesize that deleterious effects of physical trauma, immunogenic microbiological agents, stress, and anxiety may be ameliorated. A particle-wave equation is cited to ascertain magnetic field parameters for application to the whole organism thereby achieving desired homeostasis; secondary to restoration of structure and function on quantum levels. We hypothesize that it is at the atomic level that physical events shape the flow of signals and the transmission of energy in bio molecular systems. References are made to experimental data indicating the aspecific efficacy of non-ionizing physiologic magnetic field profiles for treatment of various pathologic states. Copyright © 2015 Elsevier Ltd. All rights reserved.

Regulation of Mammalian Physiology by Interconnected Circadian and Feeding Rhythms

PubMed Central

Atger, Florian; Mauvoisin, Daniel; Weger, Benjamin; Gobet, Cédric; Gachon, Frédéric

2017-01-01

Circadian clocks are endogenous timekeeping systems that adapt in an anticipatory fashion the physiology and behavior of most living organisms. In mammals, the master pacemaker resides in the suprachiasmatic nucleus and entrains peripheral clocks using a wide range of signals that differentially schedule physiology and gene expression in a tissue-specific manner. The peripheral clocks, such as those found in the liver, are particularly sensitive to rhythmic external cues like feeding behavior, which modulate the phase and amplitude of rhythmic gene expression. Consequently, the liver clock temporally tunes the expression of many genes involved in metabolism and physiology. However, the circadian modulation of cellular functions also relies on multiple layers of posttranscriptional and posttranslational regulation. Strikingly, these additional regulatory events may happen independently of any transcriptional oscillations, showing that complex regulatory networks ultimately drive circadian output functions. These rhythmic events also integrate feeding-related cues and adapt various metabolic processes to food availability schedules. The importance of such temporal regulation of metabolism is illustrated by metabolic dysfunctions and diseases resulting from circadian clock disruption or inappropriate feeding patterns. Therefore, the study of circadian clocks and rhythmic feeding behavior should be of interest to further advance our understanding of the prevention and therapy of metabolic diseases. PMID:28337174

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

PubMed

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.

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

PubMed Central

PSIKUTA, Agnes; KOELBLEN, Barbara; MERT, Emel; FONTANA, Piero; ANNAHEIM, Simon

2017-01-01

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. PMID:28966294

Beyond Fractals and 1/f Noise: Multifractal Analysis of Complex Physiological Time Series

NASA Astrophysics Data System (ADS)

Ivanov, Plamen Ch.; Amaral, Luis A. N.; Ashkenazy, Yosef; Stanley, H. Eugene; Goldberger, Ary L.; Hausdorff, Jeffrey M.; Yoneyama, Mitsuru; Arai, Kuniharu

2001-03-01

We investigate time series with 1/f-like spectra generated by two physiologic control systems --- the human heartbeat and human gait. We show that physiological fluctuations exhibit unexpected ``hidden'' structures often described by scaling laws. In particular, our studies indicate that when analyzed on different time scales the heartbeat fluctuations exhibit cascades of branching patterns with self-similar (fractal) properties, characterized by long-range power-law anticorrelations. We find that these scaling features change during sleep and wake phases, and with pathological perturbations. Further, by means of a new wavelet-based technique, we find evidence of multifractality in the healthy human heartbeat even under resting conditions, and show that the multifractal character and nonlinear properties of the healthy heart are encoded in the Fourier phases. We uncover a loss of multifractality for a life-threatening condition, congestive heart failure. In contrast to the heartbeat, we find that the interstride interval time series of healthy human gait, a voluntary process under neural regulation, is described by a single fractal dimension (such as classical 1/f noise) indicating monofractal behavior. Thus our approach can help distinguish physiological and physical signals with comparable frequency spectra and two-point correlations, and guide modeling of their control mechanisms.

Bioaccessibility of selenium, selenomethionine and selenocysteine from foods and influence of heat processing on the same.

PubMed

Khanam, Anjum; Platel, Kalpana

2016-03-01

Selenium (Se) is an essential nutrient with diverse physiological functions. The selenium content of commonly consumed cereals, pulses and green leafy vegetables (GLV) was determined. Bioaccessibility of Se, and its organic forms selenomethionine (SeMet), and selenocysteine (SeCys2) was also examined, and the effect of heat processing on the same was studied. The bioaccessibility of Se in cereals ranged from 10% to 24%, that of pulses was between 12% and 29%, and of GLV, 10-31%. The concentration of SeMet in the dialysates of the cereals, pulses and GLV ranged from 5.15 to 28.7, 2.7 to 36.2, and 0.03 to 5ngg(-1), respectively. The concentration of SeCys2 in the dialysates of the foods examined was negligible. Heat processing significantly decreased the bioaccessibility of Se, SeMet and SeCys2. This is the first report on the bioaccessibility of Se and its major organic forms from commonly consumed staples, and the effect of heat processing on the same. Copyright © 2015 Elsevier Ltd. All rights reserved.

Awakening of a Dormant Cyanobacterium from Nitrogen Chlorosis Reveals a Genetically Determined Program.

PubMed

Klotz, Alexander; Georg, Jens; Bučinská, Lenka; Watanabe, Satoru; Reimann, Viktoria; Januszewski, Witold; Sobotka, Roman; Jendrossek, Dieter; Hess, Wolfgang R; Forchhammer, Karl

2016-11-07

The molecular and physiological mechanisms involved in the transition of microbial cells from a resting state to the active vegetative state are critically relevant for solving problems in fields ranging from microbial ecology to infection microbiology. Cyanobacteria that cannot fix nitrogen are able to survive prolonged periods of nitrogen starvation as chlorotic cells in a dormant state. When provided with a usable nitrogen source, these cells re-green within 48 hr and return to vegetative growth. Here we investigated the resuscitation of chlorotic Synechocystis sp. PCC 6803 cells at the physiological and molecular levels with the aim of understanding the awakening process of a dormant bacterium. Almost immediately upon nitrate addition, the cells initiated a highly organized resuscitation program. In the first phase, they suppressed any residual photosynthetic activity and activated respiration to gain energy from glycogen catabolism. Concomitantly, they restored the entire translational apparatus, ATP synthesis, and nitrate assimilation. After only 12-16 hr, the cells re-activated the synthesis of the photosynthetic apparatus and prepared for metabolic re-wiring toward photosynthesis. When the cells reached full photosynthetic capacity after ∼48 hr, they resumed cell division and entered the vegetative cell cycle. An analysis of the transcriptional dynamics during the resuscitation process revealed a perfect match to the observed physiological processes, and it suggested that non-coding RNAs play a major regulatory role during the lifestyle switch in awakening cells. This genetically encoded program ensures rapid colonization of habitats in which nitrogen starvation imposes a recurring growth limitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

A needle-type sensor for monitoring glucose in whole blood.

PubMed

Yang, Q; Atanasov, P; Wilkins, E

1997-01-01

A new surface-process technology employing electrochemical fixation of a bioactive substance (enzyme and heparin) to a sensor electrode was developed to provide biocompatability and functionality. The fabrication process includes electroentrapment of glucose oxidase and heparin on a platinum electrode by using 1,3-phenylenediamine codeposition. Electrochemically grown 1,3-phenylenediamine was also used as the outer coating of the sensor's enzyme electrode in order to extend the linear range. The sensor shows a sensitivity of 3 nA/mM and a linear range from 40 to 400 mg/dL at 37 degrees C when tested in whole blood. This sensor is characterized by a fast response. The sensor shows a minimum change in its performance when stored inactive in buffer for 12 weeks. When tested at physiologic glucose levels, the sensor demonstrates satisfactory low interference from common interfering substances. This technology seems promising for the preparation of implantable intravascular biosensors.

A review of signals used in sleep analysis

PubMed Central

Roebuck, A; Monasterio, V; Gederi, E; Osipov, M; Behar, J; Malhotra, A; Penzel, T; Clifford, GD

2014-01-01

This article presents a review of signals used for measuring physiology and activity during sleep and techniques for extracting information from these signals. We examine both clinical needs and biomedical signal processing approaches across a range of sensor types. Issues with recording and analysing the signals are discussed, together with their applicability to various clinical disorders. Both univariate and data fusion (exploiting the diverse characteristics of the primary recorded signals) approaches are discussed, together with a comparison of automated methods for analysing sleep. PMID:24346125

To develop a spectral analyzer for physiological and medical use

NASA Technical Reports Server (NTRS)

Iberall, A.; Cardon, S.; Weinberg, M.; Schindler, A.

1971-01-01

Scientific requirements necessary to develop a spectral analyzer for monitoring mammalian subjects, are discussed. The analyzer measures dynamic or time dependent data as a measure of the subjects operating status. Measurable data include metabolic rate, body temperature, and blood constituents like glucose, oxygen, and carbon dioxide, and lactic acid. Metabolic cycles were found with periodicities in the range of minutes and hours; longer cycles in body weight (3 1/2 days and 60 days), indicative of metabolic processes, were also found.

Climate change and evolutionary adaptation.

PubMed

Hoffmann, Ary A; Sgrò, Carla M

2011-02-24

Evolutionary adaptation can be rapid and potentially help species counter stressful conditions or realize ecological opportunities arising from climate change. The challenges are to understand when evolution will occur and to identify potential evolutionary winners as well as losers, such as species lacking adaptive capacity living near physiological limits. Evolutionary processes also need to be incorporated into management programmes designed to minimize biodiversity loss under rapid climate change. These challenges can be met through realistic models of evolutionary change linked to experimental data across a range of taxa.

Making useful gadgets with miniaturized G proteins

PubMed Central

Martemyanov, Kirill A.; Garcia-Marcos, Mikel

2018-01-01

G protein–coupled receptors (GPCRs) relay information from extracellular stimuli to intracellular responses in a wide range of physiological and pathological processes, but understanding their complex effects in live cells is a daunting task. In this issue of JBC, Wan et al. repurpose “mini G proteins”—previously used as affinity tools for structural studies—to develop a suite of probes to visualize GPCR activation in live cells. The approach is expected to revolutionize our understanding of the spatiotemporal control and mechanisms of GPCR signaling. PMID:29752421

Human Responses to Exercise-Heat Stress

DTIC Science & Technology

1993-11-01

temperature Is usually regulated within a narrowv range (350 to 41 * G ). This is accomplished through two parallel processes: behaviora’ temperature...min (245 kJ.°C"+38.4 kJ.min"). Since the latent heat of evaporation for sweat is 2.43 kJ- g ", this man would need to evaporate -16 g of sweat per min...wgT reduce physiological strain and improve exercise performance during subsequent heat exposures’. Exercise in the heat is the most 4Ac& g to a

Low-Temperature Solution Processable Electrodes for Piezoelectric Sensors Applications

NASA Astrophysics Data System (ADS)

Tuukkanen, Sampo; Julin, Tuomas; Rantanen, Ville; Zakrzewski, Mari; Moilanen, Pasi; Lupo, Donald

2013-05-01

Piezoelectric thin-film sensors are suitable for a wide range of applications from physiological measurements to industrial monitoring systems. The use of flexible materials in combination with high-throughput printing technologies enables cost-effective manufacturing of custom-designed, highly integratable piezoelectric sensors. This type of sensor can, for instance, improve industrial process control or enable the embedding of ubiquitous sensors in our living environment to improve quality of life. Here, we discuss the benefits, challenges and potential applications of piezoelectric thin-film sensors. The piezoelectric sensor elements are fabricated by printing electrodes on both sides of unmetallized poly(vinylidene fluoride) film. We show that materials which are solution processable in low temperatures, biocompatible and environmental friendly are suitable for use as electrode materials in piezoelectric sensors.

Dispositional Mindfulness Uncouples Physiological and Emotional Reactivity to a Laboratory Stressor and Emotional Reactivity to Executive Functioning Lapses in Daily Life

PubMed Central

Feldman, Greg; Lavalle, Jayne; Gildawie, Kelsea; Greeson, Jeffrey M.

2016-01-01

Both dispositional mindfulness and mindfulness training may help to uncouple the degree to which distress is experienced in response to aversive internal experience and external events. Because emotional reactivity is a transdiagnostic process implicated in numerous psychological disorders, dispositional mindfulness and mindfulness training could exert mental health benefits, in part, by buffering emotional reactivity. The present studies examine whether dispositional mindfulness moderates two understudied processes in stress reactivity research: the degree of concordance between subjective and physiological reactivity to a laboratory stressor (Study 1); and the degree of dysphoric mood reactivity to lapses in executive functioning in daily life (Study 2). In both studies, lower emotional reactivity to aversive experiences was observed among individuals scoring higher in mindfulness, particularly non-judging, relative to those scoring lower in mindfulness. These findings support the hypothesis that higher dispositional mindfulness fosters lower emotional reactivity. Results are discussed in terms of implications for applying mindfulness-based interventions to a range of psychological disorders in which people have difficulty regulating emotional reactions to stress. PMID:27087863

Inhibition of pectin methyl esterase activity by green tea catechins.

PubMed

Lewis, Kristin C; Selzer, Tzvia; Shahar, Chen; Udi, Yael; Tworowski, Dmitry; Sagi, Irit

2008-10-01

Pectin methyl esterases (PMEs) and their endogenous inhibitors are involved in the regulation of many processes in plant physiology, ranging from tissue growth and fruit ripening to parasitic plant haustorial formation and host invasion. Thus, control of PME activity is critical for enhancing our understanding of plant physiological processes and regulation. Here, we report on the identification of epigallocatechin gallate (EGCG), a green tea component, as a natural inhibitor for pectin methyl esterases. In a gel assay for PME activity, EGCG blocked esterase activity of pure PME as well as PME extracts from citrus and from parasitic plants. Fluorometric tests were used to determine the IC50 for a synthetic substrate. Molecular docking analysis of PME and EGCG suggests close interaction of EGCG with the catalytic cleft of PME. Inhibition of PME by the green tea compound, EGCG, provides the means to study the diverse roles of PMEs in cell wall metabolism and plant development. In addition, this study introduces the use of EGCG as natural product to be used in the food industry and agriculture.

Dispositional Mindfulness Uncouples Physiological and Emotional Reactivity to a Laboratory Stressor and Emotional Reactivity to Executive Functioning Lapses in Daily Life.

PubMed

Feldman, Greg; Lavalle, Jayne; Gildawie, Kelsea; Greeson, Jeffrey M

2016-04-01

Both dispositional mindfulness and mindfulness training may help to uncouple the degree to which distress is experienced in response to aversive internal experience and external events. Because emotional reactivity is a transdiagnostic process implicated in numerous psychological disorders, dispositional mindfulness and mindfulness training could exert mental health benefits, in part, by buffering emotional reactivity. The present studies examine whether dispositional mindfulness moderates two understudied processes in stress reactivity research: the degree of concordance between subjective and physiological reactivity to a laboratory stressor (Study 1); and the degree of dysphoric mood reactivity to lapses in executive functioning in daily life (Study 2). In both studies, lower emotional reactivity to aversive experiences was observed among individuals scoring higher in mindfulness, particularly non-judging, relative to those scoring lower in mindfulness. These findings support the hypothesis that higher dispositional mindfulness fosters lower emotional reactivity. Results are discussed in terms of implications for applying mindfulness-based interventions to a range of psychological disorders in which people have difficulty regulating emotional reactions to stress.

TRPP2 ion channels: Critical regulators of organ morphogenesis in health and disease.

PubMed

Busch, Tilman; Köttgen, Michael; Hofherr, Alexis

2017-09-01

Ion channels control the membrane potential and mediate transport of ions across membranes. Archetypical physiological functions of ion channels include processes such as regulation of neuronal excitability, muscle contraction, or transepithelial ion transport. In that regard, transient receptor potential ion channel polycystin 2 (TRPP2) is remarkable, because it controls complex morphogenetic processes such as the establishment of properly shaped epithelial tubules and left-right-asymmetry of organs. The fascinating question of how an ion channel regulates morphogenesis has since captivated the attention of scientists in different disciplines. Four loosely connected key insights on different levels of biological complexity ranging from protein to whole organism have framed our understanding of TRPP2 physiology: 1) TRPP2 is a non-selective cation channel; 2) TRPP2 is part of a receptor-ion channel complex; 3) TRPP2 localizes to primary cilia; and 4) TRPP2 is required for organ morphogenesis. In this review, we will discuss the current knowledge in these key areas and highlight some of the challenges ahead. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Classical Renin-Angiotensin System in Kidney Physiology

PubMed Central

Sparks, Matthew A.; Crowley, Steven D.; Gurley, Susan B.; Mirotsou, Maria; Coffman, Thomas M.

2014-01-01

The renin-angiotensin system has powerful effects in control of the blood pressure and sodium homeostasis. These actions are coordinated through integrated actions in the kidney, cardio-vascular system and the central nervous system. Along with its impact on blood pressure, the renin-angiotensin system also influences a range of processes from inflammation and immune responses to longevity. Here, we review the actions of the “classical” renin-angiotensin system, whereby the substrate protein angiotensinogen is processed in a two-step reaction by renin and angiotensin converting enzyme, resulting in the sequential generation of angiotensin I and angiotensin II, the major biologically active renin-angiotensin system peptide, which exerts its actions via type 1 and type 2 angiotensin receptors. In recent years, several new enzymes, peptides, and receptors related to the renin-angiotensin system have been identified, manifesting a complexity that was previously unappreciated. While the functions of these alternative pathways will be reviewed elsewhere in this journal, our focus here is on the physiological role of components of the “classical” renin-angiotensin system, with an emphasis on new developments and modern concepts. PMID:24944035

A Skin-attachable Flexible Piezoelectric Pulse Wave Energy Harvester

NASA Astrophysics Data System (ADS)

Yoon, Sunghyun; Cho, Young-Ho

2014-11-01

We present a flexible piezoelectric generator, capable to harvest energy from human arterial pulse wave on the human wrist. Special features and advantages of the flexible piezoelectric generator include the multi-layer device design with contact windows and the simple fabrication process for the higher flexibility with the better energy harvesting efficiency. We have demonstrated the design effectiveness and the process simplicity of our skin- attachable flexible piezoelectric pulse wave energy harvester, composed of the sensitive P(VDF-TrFE) piezoelectric layer on the flexible polyimide support layer with windows. We experimentally characterize and demonstrate the energy harvesting capability of 0.2~1.0μW in the Human heart rate range on the skin contact area of 3.71cm2. Additional physiological and/or vital signal monitoring devices can be fabricated and integrated on the skin attachable flexible generator, covered by an insulation layer; thus demonstrating the potentials and advantages of the present device for such applications to the flexible multi-functional selfpowered artificial skins, capable to detect physiological and/or vital signals on Human skin using the energy harvested from arterial pulse waves.

Bioactive Peptides in Animal Food Products.

PubMed

Albenzio, Marzia; Santillo, Antonella; Caroprese, Mariangela; Della Malva, Antonella; Marino, Rosaria

2017-05-09

Proteins of animal origin represent physiologically active components in the human diet; they exert a direct action or constitute a substrate for enzymatic hydrolysis upon food processing and consumption. Bioactive peptides may descend from the hydrolysis by digestive enzymes, enzymes endogenous to raw food materials, and enzymes from microorganisms added during food processing. Milk proteins have different polymorphisms for each dairy species that influence the amount and the biochemical characteristics (e.g., amino acid chain, phosphorylation, and glycosylation) of the protein. Milk from other species alternative to cow has been exploited for their role in children with cow milk allergy and in some infant pathologies, such as epilepsy, by monitoring the immune status. Different mechanisms concur for bioactive peptides generation from meat and meat products, and their functionality and application as functional ingredients have proven effects on consumer health. Animal food proteins are currently the main source of a range of biologically-active peptides which have gained special interest because they may also influence numerous physiological responses in the organism. The addition of probiotics to animal food products represent a strategy for the increase of molecules with health and functional properties.

An End-to-End Model of Plant Pheromone Channel for Long Range Molecular Communication.

PubMed

Unluturk, Bige D; Akyildiz, Ian F

2017-01-01

A new track in molecular communication is using pheromones which can scale up the range of diffusion-based communication from μm meters to meters and enable new applications requiring long range. Pheromone communication is the emission of molecules in the air which trigger behavioral or physiological responses in receiving organisms. The objective of this paper is to introduce a new end-to-end model which incorporates pheromone behavior with communication theory for plants. The proposed model includes both the transmission and reception processes as well as the propagation channel. The transmission process is the emission of pheromones from the leaves of plants. The dispersion of pheromones by the flow of wind constitutes the propagation process. The reception process is the sensing of pheromones by the pheromone receptors of plants. The major difference of pheromone communication from other molecular communication techniques is the dispersion channel acting under the laws of turbulent diffusion. In this paper, the pheromone channel is modeled as a Gaussian puff, i.e., a cloud of pheromone released instantaneously from the source whose dispersion follows a Gaussian distribution. Numerical results on the performance of the overall end-to-end pheromone channel in terms of normalized gain and delay are provided.

Physiological and behavioural assessment of pain in ruminants: principles and caveats.

PubMed

Mellor, David J; Stafford, Kevin J

2004-06-01

Pain elicits a range of physiological and behavioural responses. These are commonly used to assess the impact of pain-inducing stimuli on animals, to determine whether or not significant pain is experienced and to devise strategies for alleviating pain. This paper outlines a range of principles and caveats to guide the evaluation of physiological and behavioural responses to painful stimuli, so that they can be better used to minimise pain in the experimental context. Although this advice is based on studies of farm animals responding to painful husbandry practices, it is more generally applicable.

Sex-specific ecophysiological responses to environmental fluctuations of free-ranging Hermann's tortoises: implication for conservation.

PubMed

Sibeaux, Adélaïde; Michel, Catherine Louise; Bonnet, Xavier; Caron, Sébastien; Fournière, Kévin; Gagno, Stephane; Ballouard, Jean-Marie

2016-01-01

Physiological parameters provide indicators to evaluate how organisms respond to conservation actions. For example, individuals translocated during reinforcement programmes may not adapt to their novel host environment and may exhibit elevated chronic levels of stress hormones and/or decreasing body condition. Conversely, successful conservation actions should be associated with a lack of detrimental physiological perturbation. However, physiological references fluctuate over time and are influenced by various factors (e.g. sex, age, reproductive status). It is therefore necessary to determine the range of natural variations of the selected physiological metrics to establish useful baselines. This study focuses on endangered free-ranging Hermann's tortoises ( Testudo hermanni hermanni ), where conservation actions have been preconized to prevent extinction of French mainland populations. The influence of sex and of environmental factors (site, year and season) on eight physiological parameters (e.g. body condition, corticosterone concentrations) was assessed in 82 individuals from two populations living in different habitats. Daily displacements were monitored by radio-tracking. Most parameters varied between years and seasons and exhibited contrasting sex patterns but with no or limited effect of site. By combining behavioural and physiological traits, this study provides sex-specific seasonal baselines that can be used to monitor the health status of Hermann's tortoises facing environmental threats (e.g. habitat changes) or during conservation actions (e.g. translocation). These results might also assist in selection of the appropriate season for translocation.

A Macrophysiological Analysis of Energetic Constraints on Geographic Range Size in Mammals

PubMed Central

Ceballos, Gerardo; Steele, Michael A.

2013-01-01

Physiological processes are essential for understanding the distribution and abundance of organisms, and recently, with widespread attention to climate change, physiology has been ushered back to the forefront of ecological thinking. We present a macrophysiological analysis of the energetics of geographic range size using combined data on body size, basal metabolic rate (BMR), phylogeny and range properties for 574 species of mammals. We propose three mechanisms by which interspecific variation in BMR should relate positively to geographic range size: (i) Thermal Plasticity Hypothesis, (ii) Activity Levels/Dispersal Hypothesis, and (iii) Energy Constraint Hypothesis. Although each mechanism predicts a positive correlation between BMR and range size, they can be further distinguished based on the shape of the relationship they predict. We found evidence for the predicted positive relationship in two dimensions of energetics: (i) the absolute, mass-dependent dimension (BMR) and (ii) the relative, mass-independent dimension (MIBMR). The shapes of both relationships were similar and most consistent with that expected from the Energy Constraint Hypothesis, which was proposed previously to explain the classic macroecological relationship between range size and body size in mammals and birds. The fact that this pattern holds in the MIBMR dimension indicates that species with supra-allometric metabolic rates require among the largest ranges, above and beyond the increasing energy demands that accrue as an allometric consequence of large body size. The relationship is most evident at high latitudes north of the Tropics, where large ranges and elevated MIBMR are most common. Our results suggest that species that are most vulnerable to extinction from range size reductions are both large-bodied and have elevated MIBMR, but also, that smaller species with elevated MIBMR are at heightened risk. We also provide insights into the global latitudinal trends in range size and MIBMR and more general issues of phylogenetic and geographic scale. PMID:24058444

On the Essence of the Mind and the Object of Psychology

DTIC Science & Technology

1960-07-26

a simple reflectional process. At one time, Wundt , unable to discriminate between the object of psychology and the object of physiology, intro...duced the new term "physiological psychology." As the objects of this science Wundt lists those vital processes which have an external as well as an...physiology alone." According to Wundt perception represents, on the one hand, only a psychological fact and, on the other hand, only a physiological act. It

Relationship between behavioral and physiological spectral-ripple discrimination.

PubMed

Won, Jong Ho; Clinard, Christopher G; Kwon, Seeyoun; Dasika, Vasant K; Nie, Kaibao; Drennan, Ward R; Tremblay, Kelly L; Rubinstein, Jay T

2011-06-01

Previous studies have found a significant correlation between spectral-ripple discrimination and speech and music perception in cochlear implant (CI) users. This relationship could be of use to clinicians and scientists who are interested in using spectral-ripple stimuli in the assessment and habilitation of CI users. However, previous psychoacoustic tasks used to assess spectral discrimination are not suitable for all populations, and it would be beneficial to develop methods that could be used to test all age ranges, including pediatric implant users. Additionally, it is important to understand how ripple stimuli are processed in the central auditory system and how their neural representation contributes to behavioral performance. For this reason, we developed a single-interval, yes/no paradigm that could potentially be used both behaviorally and electrophysiologically to estimate spectral-ripple threshold. In experiment 1, behavioral thresholds obtained using the single-interval method were compared to thresholds obtained using a previously established three-alternative forced-choice method. A significant correlation was found (r = 0.84, p = 0.0002) in 14 adult CI users. The spectral-ripple threshold obtained using the new method also correlated with speech perception in quiet and noise. In experiment 2, the effect of the number of vocoder-processing channels on the behavioral and physiological threshold in normal-hearing listeners was determined. Behavioral thresholds, using the new single-interval method, as well as cortical P1-N1-P2 responses changed as a function of the number of channels. Better behavioral and physiological performance (i.e., better discrimination ability at higher ripple densities) was observed as more channels added. In experiment 3, the relationship between behavioral and physiological data was examined. Amplitudes of the P1-N1-P2 "change" responses were significantly correlated with d' values from the single-interval behavioral procedure. Results suggest that the single-interval procedure with spectral-ripple phase inversion in ongoing stimuli is a valid approach for measuring behavioral or physiological spectral resolution.

Environmental stressors alter relationships between physiology and behaviour.

PubMed

Killen, Shaun S; Marras, Stefano; Metcalfe, Neil B; McKenzie, David J; Domenici, Paolo

2013-11-01

Although correlations have frequently been observed between specific physiological and behavioural traits across a range of animal taxa, the nature of these associations has been shown to vary. Here we argue that a major source of this inconsistency is the influence of environmental stressors, which seem capable of revealing, masking, or modulating covariation in physiological and behavioural traits. These effects appear to be mediated by changes in the observed variation of traits and differential sensitivity to stressors among phenotypes. Considering that wild animals routinely face a range of biotic and abiotic stressors, increased knowledge of these effects is imperative for understanding the causal mechanisms of a range of ecological phenomena and evolutionary responses to stressors associated with environmental change. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

All or nothing: Survival, reproduction and oxidative balance in Spotted Wing Drosophila (Drosophila suzukii) in response to cold.

PubMed

Plantamp, Christophe; Salort, Katleen; Gibert, Patricia; Dumet, Adeline; Mialdea, Gladys; Mondy, Nathalie; Voituron, Yann

2016-06-01

Winter severity and overwintering capacity are key ecological factors in successful invasions, especially in ectotherms. The integration of physiological approaches into the study of invasion processes is emerging and promising. Physiological information describes the mechanisms underlying observed survival and reproductive capacities, and it can be used to predict an organism's response to environmental perturbations such as cold temperatures. We investigated the effects of various cold treatments on life history and physiological traits of an invasive pest species, Drosophila suzukii, such as survival, fertility and oxidative balance. This species, a native of temperate Asian areas, is known to survive where cold temperatures are particularly harsh and has been recently introduced into Europe and North America. We found that cold treatments had a strong impact on adult survival but no effect on female's fertility. Although only minor changes were observed after cold treatment on studied physiological traits, a strong sex-based difference was observed in both survival and physiological markers (antioxidant defences and oxidative markers). Females exhibited higher survival, reduced oxidative defences, less damage to nucleic acids, and more damage to lipids. These results suggest that D. suzukii relies on a pathway other than oxidative balance to resist cold injury. Altogether, our results provide information concerning the mechanisms of successful invasion by D. suzukii. These findings may assist in the development of population models that predict the current and future geographic ranges of this species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Century long assessment of herbaceous plants' physiological responses to climate change in Switzerland

NASA Astrophysics Data System (ADS)

Moreno-Gutierrez, Cristina; Kahmen, Ansgar

2017-04-01

The isotopic analysis of archived plant material offers the exceptional opportunity to reconstruct the physiological activity of plants over long time periods and thus, to assess plant responses to environmental changes during the last centuries. In addition, the stable isotope analysis of herbarium samples offers the opportunity to reconstruct the physiological processes of a large range of different plant species and from different environments. Interestingly, only few studies have to date assessed these archives. We will present a novel analysis of leaf nitrogen, oxygen and carbon isotope ratios of more than a thousand herbarium specimens collected since 1800 until present from the unique herbaria hold at the University of Basel. The objective of our study was to assess century-long physiological responses of herbaceous plant species from different plant functional groups and along an altitudinal gradient in Switzerland. The goal of our study was to determine with our investigations the long-term responses of plants to climate change. Such investigations are important as they allow to assess long-term processes of acclimation and adaptation in plants to global enviromental change. In our study we found that herbaceous plants have increased their intrinsic water use efficiency in response to increasing atmospheric CO2 concentration but this increment was higher in plants from higher altitudes, due to the higher efficiency of CO2 assimilation of alpine plants compared to plants from lowlands. There were also differences among functional groups, with grasses and forbs showing the highest increments. In addition, herbaceous plants showed a decreasing trend with time in their N isotopic composition, which may indicate progressive N limitation due to higher biological activity with increasing atmospheric CO2 concentration.

Conceptual analysis of Physiology of vision in Ayurveda.

PubMed

Balakrishnan, Praveen; Ashwini, M J

2014-07-01

The process by which the world outside is seen is termed as visual process or physiology of vision. There are three phases in this visual process: phase of refraction of light, phase of conversion of light energy into electrical impulse and finally peripheral and central neurophysiology. With the advent of modern instruments step by step biochemical changes occurring at each level of the visual process has been deciphered. Many investigations have emerged to track these changes and helping to diagnose the exact nature of the disease. Ayurveda has described this physiology of vision based on the functions of vata and pitta. Philosophical textbook of ayurveda, Tarka Sangraha, gives certain basics facts of visual process. This article discusses the second and third phase of visual process. Step by step analysis of the visual process through the spectacles of ayurveda amalgamated with the basics of philosophy from Tarka Sangraha has been analyzed critically to generate a concrete idea regarding the physiology and hence thereby interpret the pathology on the grounds of ayurveda based on the investigative reports.

[Sociophysiology: basic processes of empathy].

PubMed

Haker, Helene; Schimansky, Jenny; Rössler, Wulf

2010-01-01

The aim of this review is to describe sociophysiological and social cognitive processes that underlie the complex phenomenon of human empathy. Automatic reflexive processes such as physiological contagion and action mirroring are mediated by the mirror neuron system. They are a basis for further processing of social signals and a physiological link between two individuals. This link comprises simultaneous activation of shared motor representations. Shared representations lead implicitly via individual associations in the limbic and vegetative system to a shared affective state. These processes are called sociophysiology. Further controlled- reflective, self-referential processing of those social signals leads to explicit, conscious representations of others' minds. Those higher-order processes are called social cognition. The interaction of physiological and cognitive social processes lets arise the phenomenon of human empathy.

Normal male sexual function: emphasis on orgasm and ejaculation.

PubMed

Alwaal, Amjad; Breyer, Benjamin N; Lue, Tom F

2015-11-01

Orgasm and ejaculation are two separate physiological processes that are sometimes difficult to distinguish. Orgasm is an intense transient peak sensation of intense pleasure creating an altered state of consciousness associated with reported physical changes. Antegrade ejaculation is a complex physiological process that is composed of two phases (emission and expulsion), and is influenced by intricate neurological and hormonal pathways. Despite the many published research projects dealing with the physiology of orgasm and ejaculation, much about this topic is still unknown. Ejaculatory dysfunction is a common disorder, and currently has no definitive cure. Understanding the complex physiology of orgasm and ejaculation allows the development of therapeutic targets for ejaculatory dysfunction. In this article, we summarize the current literature on the physiology of orgasm and ejaculation, starting with a brief description of the anatomy of sex organs and the physiology of erection. Then, we describe the physiology of orgasm and ejaculation detailing the neuronal, neurochemical, and hormonal control of the ejaculation process. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Cellular metabolic rates from primary dermal fibroblast cells isolated from birds of different body masses.

PubMed

Jimenez, Ana Gabriela; Williams, Joseph B

2014-10-01

The rate of metabolism is the speed at which organisms use energy, an integration of energy transformations within the body; it governs biological processes that influence rates of growth and reproduction. Progress at understanding functional linkages between whole organism metabolic rate and underlying mechanisms that influence its magnitude has been slow despite the central role this issue plays in evolutionary and physiological ecology. Previous studies that have attempted to relate how cellular processes translate into whole-organism physiology have done so over a range of body masses of subjects. However, the data still remains controversial when observing metabolic rates at the cellular level. To bridge the gap between these ideas, we examined cellular metabolic rate of primary dermal fibroblasts isolated from 49 species of birds representing a 32,000-fold range in body masses to test the hypothesis that metabolic rate of cultured cells scales with body size. We used a Seahorse XF-96 Extracellular flux analyzer to measure cellular respiration in fibroblasts. Additionally, we measured fibroblast size and mitochondrial content. We found no significant correlation between cellular metabolic rate, cell size, or mitochondrial content and body mass. Additionally, there was a significant relationship between cellular basal metabolic rate and proton leak in these cells. We conclude that metabolic rate of cells isolated in culture does not scale with body mass, but cellular metabolic rate is correlated to growth rate in birds. Copyright © 2014 Elsevier Inc. All rights reserved.

Theory of Inpatient Circadian Care (TICC): A Proposal for a Middle-Range Theory

PubMed Central

Camargo-Sanchez, Andrés; Niño, Carmen L; Sánchez, Leonardo; Echeverri, Sonia; Gutiérrez, Diana P; Duque, Andrés F; Pianeta, Oscar; Jaramillo-Gómez, Jenny A; Pilonieta, Martin A; Cataño, Nhora; Arboleda, Humberto; Agostino, Patricia V; Alvarez-Baron, Claudia P; Vargas, Rafael

2015-01-01

The circadian system controls the daily rhythms of a variety of physiological processes. Most organisms show physiological, metabolic and behavioral rhythms that are coupled to environmental signals. In humans, the main synchronizer is the light/dark cycle, although non-photic cues such as food availability, noise, and work schedules are also involved. In a continuously operating hospital, the lack of rhythmicity in these elements can alter the patient’s biological rhythms and resilience. This paper presents a Theory of Inpatient Circadian Care (TICC) grounded in circadian principles. We conducted a literature search on biological rhythms, chronobiology, nursing care, and middle-range theories in the databases PubMed, SciELO Public Health, and Google Scholar. The search was performed considering a period of 6 decades from 1950 to 2013. Information was analyzed to look for links between chronobiology concepts and characteristics of inpatient care. TICC aims to integrate multidisciplinary knowledge of biomedical sciences and apply it to clinical practice in a formal way. The conceptual points of this theory are supported by abundant literature related to disease and altered biological rhythms. Our theory will be able to enrich current and future professional practice. PMID:25767632

Model of head-neck joint fast movements in the frontal plane.

PubMed

Pedrocchi, A; Ferrigno, G

2004-06-01

The objective of this work is to develop a model representing the physiological systems driving fast head movements in frontal plane. All the contributions occurring mechanically in the head movement are considered: damping, stiffness, physiological limit of range of motion, gravitational field, and muscular torques due to voluntary activation as well as to stretch reflex depending on fusal afferences. Model parameters are partly derived from the literature, when possible, whereas undetermined block parameters are determined by optimising the model output, fitting to real kinematics data acquired by a motion capture system in specific experimental set-ups. The optimisation for parameter identification is performed by genetic algorithms. Results show that the model represents very well fast head movements in the whole range of inclination in the frontal plane. Such a model could be proposed as a tool for transforming kinematics data on head movements in 'neural equivalent data', especially for assessing head control disease and properly planning the rehabilitation process. In addition, the use of genetic algorithms seems to fit well the problem of parameter identification, allowing for the use of a very simple experimental set-up and granting model robustness.

Pressure and Temperature Changes in In Vitro Applications with the Laser and Their Implications for Middle Ear Surgery

PubMed Central

Schwab, Burkard; Kontorinis, Georgios

2010-01-01

Background. The purpose of this study was to evaluate the thermal and pressure effects using a Titan Sapphire chirped-pulse amplifier system configured to deliver ultrashort pulses of 180 femtoseconds (fs) in an inner ear model. Materials and Methods. Temperature increases and heat exchange processes in the fluid (physiological saline) were examined in a calorically and physiologically approximated cochlea model for applying laser parameters effective in the creation of footplate perforations. Results. In the effective energy density range, the highest temperature increases achieved with the Carbon dioxide (CO2) laser were about 11 degrees C. The lowest temperature maxima were 6 degrees C with the Er:YAG laser (Yttrium-Aluminum-Oxide doted with Erbium3+-ions) and <5 degrees C with the femtosecond laser. Comparison of the laser-induced pressure with the limit graph published by Pfander indicated that the use of the fs laser is unobjectionable for fluences <1 J/cm2. Conclusions. Our investigations demonstrated that the application of the fs laser in middle ear surgery presents a new and promising addition to the range of ultrashort wavelength lasers used for this purpose. PMID:20953354

The influence of age, anxiety and concern about falling on postural sway when standing at an elevated level.

PubMed

Sturnieks, Daina L; Delbaere, Kim; Brodie, Matthew A; Lord, Stephen R

2016-10-01

Psychological processes may influence balance and contribute to the risk of falls in older people. While a self-reported fear of falling is associated with increased postural sway, inducing fear using an elevated platform can lead to reduced sway, suggesting different underlying mechanisms whereby fear may influence balance control. This study examined changes in postural sway, muscle activity and physiological measures of arousal while standing on a 65cm elevated platform, compared to floor level, in young and older adults. The older adults were classified as fall concerned or not fall concerned based on the Falls Efficacy Scale-International and anxious or not anxious based on the Goldberg Anxiety Scale. Fall concern did not affect the physiological and sway response to the elevated platform. In response to the postural threat, the anxious participants increased their sway frequency (p=0.001) but did not reduce sway range (p=0.674). Conversely, non-anxious participants showed an adaptive tightening of balance control, effectively reducing sway range in the elevated condition (p<0.001). Generalised anxiety in older adults appears to differentially affect postural control strategies under threatening conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Ecological and physiological thermal niches to understand distribution of Chagas disease vectors in Latin America.

PubMed

DE LA Vega, G J; Schilman, P E

2018-03-01

In order to assess how triatomines (Hemiptera, Reduviidae), Chagas disease vectors, are distributed through Latin America, we analysed the relationship between the ecological niche and the limits of the physiological thermal niche in seven species of triatomines. We combined two methodological approaches: species distribution models, and physiological tolerances. First, we modelled the ecological niche and identified the most important abiotic factor for their distribution. Then, thermal tolerance limits were analysed by measuring maximum and minimum critical temperatures, upper lethal temperature, and 'chill-coma recovery time'. Finally, we used phylogenetic independent contrasts to analyse the link between limiting factors and the thermal tolerance range for the assessment of ecological hypotheses that provide a different outlook for the geo-epidemiology of Chagas disease. In triatomines, thermo-tolerance range increases with increasing latitude mainly due to better cold tolerances, suggesting an effect of thermal selection. In turn, physiological analyses show that species reaching southernmost areas have a higher thermo-tolerance than those with tropical distributions, denoting that thermo-tolerance is limiting the southern distribution. Understanding the latitudinal range along its physiological limits of disease vectors may prove useful to test ecological hypotheses and improve strategies and efficiency of vector control at the local and regional levels. © 2017 The Royal Entomological Society.

How can the study of physiological reactivity contribute to our understanding of adversity and resilience processes in development?

PubMed

Obradović, Jelena

2012-05-01

The focus of this article is to present current progress in understanding the interplay among adversity, physiological sensitivity to context, and adaptive functioning, with an emphasis on implications and future directions for resilience researchers. It includes a review of current literature that demonstrates (a) links between various levels of adversity exposure and variability in physiological reactivity, (b) how the interplay between children's physiological reactivity and different sources of risk and adversity relates to variability in adaptive functioning, and (c) various approaches for capturing a more dynamic nature of physiological reactivity and related processes. Throughout, important conceptual and empirical issues are highlighted.

The Core Principles ("Big Ideas") of Physiology: Results of Faculty Surveys

ERIC Educational Resources Information Center

Michael, Joel; McFarland, Jenny

2011-01-01

Physiology faculty members at a wide range of institutions (2-yr colleges to medical schools) were surveyed to determine what core principles of physiology they want their students to understand. From the results of the first survey, 15 core principles were described. In a second survey, respondents were asked to rank order these 15 core…

Optical properties of in-vitro biomineralised silica.

PubMed

Polini, Alessandro; Pagliara, Stefano; Camposeo, Andrea; Cingolani, Roberto; Wang, Xiaohong; Schröder, Heinz C; Müller, Werner E G; Pisignano, Dario

2012-01-01

Silicon is the second most common element on the Earth's crust and its oxide (SiO(2)) the most abundant mineral. Silica and silicates are widely used in medicine and industry as well as in micro- and nano-optics and electronics. However, the fabrication of glass fibres and components requires high temperature and non-physiological conditions, in contrast to biosilica structures in animals and plants. Here, we show for the first time the use of recombinant silicatein-α, the most abundant subunit of sponge proteins catalyzing biosilicification reactions, to direct the formation of optical waveguides in-vitro through soft microlithography. The artificial biosilica fibres mimic the natural sponge spicules, exhibiting refractive index values suitable for confinement of light within waveguides, with optical losses in the range of 5-10 cm(-1), suitable for application in lab-on-chips systems. This method extends biosilicification to the controlled fabrication of optical components by physiological processing conditions, hardly addressed by conventional technologies.

The mechanical response of talin

NASA Astrophysics Data System (ADS)

Yao, Mingxi; Goult, Benjamin T.; Klapholz, Benjamin; Hu, Xian; Toseland, Christopher P.; Guo, Yingjian; Cong, Peiwen; Sheetz, Michael P.; Yan, Jie

2016-07-01

Talin, a force-bearing cytoplasmic adapter essential for integrin-mediated cell adhesion, links the actin cytoskeleton to integrin-based cell-extracellular matrix adhesions at the plasma membrane. Its C-terminal rod domain, which contains 13 helical bundles, plays important roles in mechanosensing during cell adhesion and spreading. However, how the structural stability and transition kinetics of the 13 helical bundles of talin are utilized in the diverse talin-dependent mechanosensing processes remains poorly understood. Here we report the force-dependent unfolding and refolding kinetics of all talin rod domains. Using experimentally determined kinetics parameters, we determined the dynamics of force fluctuation during stretching of talin under physiologically relevant pulling speeds and experimentally measured extension fluctuation trajectories. Our results reveal that force-dependent stochastic unfolding and refolding of talin rod domains make talin a very effective force buffer that sets a physiological force range of only a few pNs in the talin-mediated force transmission pathway.

Ethane-Bridged Bisporphyrin Conformational Changes As an Effective Analytical Tool for Nonenzymatic Detection of Urea in the Physiological Range.

PubMed

Buccolieri, Alessandro; Hasan, Mohammed; Bettini, Simona; Bonfrate, Valentina; Salvatore, Luca; Santino, Angelo; Borovkov, Victor; Giancane, Gabriele

2018-06-05

Conformational switching induced in ethane-bridged bisporphyrins was used as a sensitive transduction method for revealing the presence of urea dissolved in water via nonenzymatic approach. Bisporphyrins were deposited on solid quartz slides by means of the spin-coating method. Molecular conformations of Zn and Ni monometalated bis-porphyrins were influenced by water solvated urea molecules and their fluorescence emission was modulated by the urea concentration. Absorption, fluorescence and Raman spectroscopies allowed the identification of supramolecular processes, which are responsible for host-guest interaction between the active layers and urea molecules. A high selectivity of the sensing mechanism was highlighted upon testing the spectroscopic responses of bis-porphyrin films to citrulline and glutamine used as interfering agents. Additionally, potential applicability was demonstrated by quantifying the urea concentration in real physiological samples proposing this new approach as a valuable alternative analytical procedure to the traditionally used enzymatic methods.

Neurons for hunger and thirst transmit a negative-valence teaching signal.

PubMed

Betley, J Nicholas; Xu, Shengjin; Cao, Zhen Fang Huang; Gong, Rong; Magnus, Christopher J; Yu, Yang; Sternson, Scott M

2015-05-14

Homeostasis is a biological principle for regulation of essential physiological parameters within a set range. Behavioural responses due to deviation from homeostasis are critical for survival, but motivational processes engaged by physiological need states are incompletely understood. We examined motivational characteristics of two separate neuron populations that regulate energy and fluid homeostasis by using cell-type-specific activity manipulations in mice. We found that starvation-sensitive AGRP neurons exhibit properties consistent with a negative-valence teaching signal. Mice avoided activation of AGRP neurons, indicating that AGRP neuron activity has negative valence. AGRP neuron inhibition conditioned preference for flavours and places. Correspondingly, deep-brain calcium imaging revealed that AGRP neuron activity rapidly reduced in response to food-related cues. Complementary experiments activating thirst-promoting neurons also conditioned avoidance. Therefore, these need-sensing neurons condition preference for environmental cues associated with nutrient or water ingestion, which is learned through reduction of negative-valence signals during restoration of homeostasis.

Chemotaxis of Cell Populations through Confined Spaces at Single-Cell Resolution

PubMed Central

Tong, ZiQiu; Balzer, Eric M.; Dallas, Matthew R.; Hung, Wei-Chien; Stebe, Kathleen J.; Konstantopoulos, Konstantinos

2012-01-01

Cell migration is crucial for both physiological and pathological processes. Current in vitro cell motility assays suffer from various drawbacks, including insufficient temporal and/or optical resolution, or the failure to include a controlled chemotactic stimulus. Here, we address these limitations with a migration chamber that utilizes a self-sustaining chemotactic gradient to induce locomotion through confined environments that emulate physiological settings. Dynamic real-time analysis of both population-scale and single-cell movement are achieved at high resolution. Interior surfaces can be functionalized through adsorption of extracellular matrix components, and pharmacological agents can be administered to cells directly, or indirectly through the chemotactic reservoir. Direct comparison of multiple cell types can be achieved in a single enclosed system to compare inherent migratory potentials. Our novel microfluidic design is therefore a powerful tool for the study of cellular chemotaxis, and is suitable for a wide range of biological and biomedical applications. PMID:22279529

Fraction of Electrons Consumed in Electron Acceptor Reduction and Hydrogen Thresholds as Indicators of Halorespiratory Physiology

PubMed Central

Löffler, Frank E.; Tiedje, James M.; Sanford, Robert A.

1999-01-01

Measurements of the hydrogen consumption threshold and the tracking of electrons transferred to the chlorinated electron acceptor (fe) reliably detected chlororespiratory physiology in both mixed cultures and pure cultures capable of using tetrachloroethene, cis-1,2-dichloroethene, vinyl chloride, 2-chlorophenol, 3-chlorobenzoate, 3-chloro-4-hydroxybenzoate, or 1,2-dichloropropane as an electron acceptor. Hydrogen was consumed to significantly lower threshold concentrations of less than 0.4 ppmv compared with the values obtained for the same cultures without a chlorinated compound as an electron acceptor. The fe values ranged from 0.63 to 0.7, values which are in good agreement with theoretical calculations based on the thermodynamics of reductive dechlorination as the terminal electron-accepting process. In contrast, a mixed methanogenic culture that cometabolized 3-chlorophenol exhibited a significantly lower fe value, 0.012. PMID:10473415

Near-Infrared Fluorescent Nanoprobes for Revealing the Role of Dopamine in Drug Addiction.

PubMed

Feng, Peijian; Chen, Yulei; Zhang, Lei; Qian, Cheng-Gen; Xiao, Xuanzhong; Han, Xu; Shen, Qun-Dong

2018-02-07

Brain imaging techniques enable visualizing the activity of central nervous system without invasive neurosurgery. Dopamine is an important neurotransmitter. Its fluctuation in brain leads to a wide range of diseases and disorders, like drug addiction, depression, and Parkinson's disease. We designed near-infrared fluorescence dopamine-responsive nanoprobes (DRNs) for brain activity imaging during drug abuse and addiction process. On the basis of light-induced electron transfer between DRNs and dopamine and molecular wire effect of the DRNs, we can track the dynamical change of the neurotransmitter level in the physiological environment and the releasing of the neurotransmitter in living dopaminergic neurons in response to nicotine stimulation. The functional near-infrared fluorescence imaging can dynamically track the dopamine level in the mice midbrain under normal or drug-activated condition and evaluate the long-term effect of addictive substances to the brain. This strategy has the potential for studying neural activity under physiological condition.

Source-based neurofeedback methods using EEG recordings: training altered brain activity in a functional brain source derived from blind source separation

PubMed Central

White, David J.; Congedo, Marco; Ciorciari, Joseph

2014-01-01

A developing literature explores the use of neurofeedback in the treatment of a range of clinical conditions, particularly ADHD and epilepsy, whilst neurofeedback also provides an experimental tool for studying the functional significance of endogenous brain activity. A critical component of any neurofeedback method is the underlying physiological signal which forms the basis for the feedback. While the past decade has seen the emergence of fMRI-based protocols training spatially confined BOLD activity, traditional neurofeedback has utilized a small number of electrode sites on the scalp. As scalp EEG at a given electrode site reflects a linear mixture of activity from multiple brain sources and artifacts, efforts to successfully acquire some level of control over the signal may be confounded by these extraneous sources. Further, in the event of successful training, these traditional neurofeedback methods are likely influencing multiple brain regions and processes. The present work describes the use of source-based signal processing methods in EEG neurofeedback. The feasibility and potential utility of such methods were explored in an experiment training increased theta oscillatory activity in a source derived from Blind Source Separation (BSS) of EEG data obtained during completion of a complex cognitive task (spatial navigation). Learned increases in theta activity were observed in two of the four participants to complete 20 sessions of neurofeedback targeting this individually defined functional brain source. Source-based EEG neurofeedback methods using BSS may offer important advantages over traditional neurofeedback, by targeting the desired physiological signal in a more functionally and spatially specific manner. Having provided preliminary evidence of the feasibility of these methods, future work may study a range of clinically and experimentally relevant brain processes where individual brain sources may be targeted by source-based EEG neurofeedback. PMID:25374520

The Brassinosteroid Signaling Pathway—New Key Players and Interconnections with Other Signaling Networks Crucial for Plant Development and Stress Tolerance

PubMed Central

Gruszka, Damian

2013-01-01

Brassinosteroids (BRs) are a class of steroid hormones regulating a wide range of physiological processes during the plant life cycle from seed development to the modulation of flowering and senescence. The last decades, and recent years in particular, have witnessed a significant advance in the elucidation of the molecular mechanisms of BR signaling from perception by the transmembrane receptor complex to the regulation of transcription factors influencing expression of the target genes. Application of the new approaches shed light on the molecular functions of the key players regulating the BR signaling cascade and allowed identification of new factors. Recent studies clearly indicated that some of the components of BR signaling pathway act as multifunctional proteins involved in other signaling networks regulating diverse physiological processes, such as photomorphogenesis, cell death control, stomatal development, flowering, plant immunity to pathogens and metabolic responses to stress conditions, including salinity. Regulation of some of these processes is mediated through a crosstalk between BR signalosome and the signaling cascades of other hormones, including auxin, abscisic acid, ethylene and salicylic acid. Unravelling the complicated mechanisms of BR signaling and its interconnections with other molecular networks may be of great importance for future practical applications in agriculture. PMID:23615468

The influence of different loads on the remodeling process of a bone and bioresorbable material mixture with voids

NASA Astrophysics Data System (ADS)

Giorgio, Ivan; Andreaus, Ugo; Madeo, Angela

2016-03-01

A model of a mixture of bone tissue and bioresorbable material with voids was used to numerically analyze the physiological balance between the processes of bone growth and resorption and artificial material resorption in a plate-like sample. The adopted model was derived from a theory for the behavior of porous solids in which the matrix material is linearly elastic and the interstices are void of material. The specimen—constituted by a region of bone living tissue and one of bioresorbable material—was acted by different in-plane loading conditions, namely pure bending and shear. Ranges of load magnitudes were identified within which physiological states become possible. Furthermore, the consequences of applying different loading conditions are examined at the end of the remodeling process. In particular, maximum value of bone and material mass densities, and extensions of the zones where bone is reconstructed were identified and compared in the two different load conditions. From the practical view point, during surgery planning and later rehabilitation, some choice of the following parameters is given: porosity of the graft, material characteristics of the graft, and adjustment of initial mixture tissue/bioresorbable material and later, during healing and remodeling, optimal loading conditions.

A high performance biometric signal and image processing method to reveal blood perfusion towards 3D oxygen saturation mapping

NASA Astrophysics Data System (ADS)

Imms, Ryan; Hu, Sijung; Azorin-Peris, Vicente; Trico, Michaël.; Summers, Ron

2014-03-01

Non-contact imaging photoplethysmography (PPG) is a recent development in the field of physiological data acquisition, currently undergoing a large amount of research to characterize and define the range of its capabilities. Contact-based PPG techniques have been broadly used in clinical scenarios for a number of years to obtain direct information about the degree of oxygen saturation for patients. With the advent of imaging techniques, there is strong potential to enable access to additional information such as multi-dimensional blood perfusion and saturation mapping. The further development of effective opto-physiological monitoring techniques is dependent upon novel modelling techniques coupled with improved sensor design and effective signal processing methodologies. The biometric signal and imaging processing platform (bSIPP) provides a comprehensive set of features for extraction and analysis of recorded iPPG data, enabling direct comparison with other biomedical diagnostic tools such as ECG and EEG. Additionally, utilizing information about the nature of tissue structure has enabled the generation of an engineering model describing the behaviour of light during its travel through the biological tissue. This enables the estimation of the relative oxygen saturation and blood perfusion in different layers of the tissue to be calculated, which has the potential to be a useful diagnostic tool.

Optimizing Performance Through Sleep-Wake Homeostasis: Integrating Physiological and Neurobehavioral Data via Ambulatory Acquisition in Laboratory and Field Environments

DTIC Science & Technology

2009-04-18

intake and sophisticated signal processing of electroencephalographic (EEG), electrooculographic ( EOG ), electrocardiographic (ECG), and...electroencephalographic (EEG), electrooculographic ( EOG ), electrocardiographic (ECG), and electromyographic (EMG) physiological signals . It also has markedly...ambulatory physiological acquisition and quantitative signal processing; (2) Brain Amp MR Plus 32 and BrainVision Recorder Professional Software Package for

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

PubMed

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.

Influences of thermal acclimation and acute temperature change on the motility of epithelial wound-healing cells (keratocytes) of tropical, temperate and Antarctic fish.

PubMed

Ream, Rachael A; Theriot, Julie A; Somero, George N

2003-12-01

The ability to heal superficial wounds is an important element in an organism's repertoire of adaptive responses to environmental stress. In fish, motile cells termed keratocytes are thought to play important roles in the wound-healing process. Keratocyte motility, like other physiological rate processes, is likely to be dependent on temperature and to show adaptive variation among differently thermally adapted species. We have quantified the effects of acute temperature change and thermal acclimation on actin-based keratocyte movement in primary cultures of keratocytes from four species of teleost fish adapted to widely different thermal conditions: two eurythermal species, the longjaw mudsucker Gillichthys mirabilis (environmental temperature range of approximately 10-37 degrees C) and a desert pupfish, Cyprinodon salinus (10-40 degrees C), and two species from stable thermal environments, an Antarctic notothenioid, Trematomus bernacchii (-1.86 degrees C), and a tropical clownfish, Amphiprion percula (26-30 degrees C). For all species, keratocyte speed increased with increasing temperature. G. mirabilis and C. salinus keratocytes reached maximal speeds at 25 degrees C and 35 degrees C, respectively, temperatures within the species' normal thermal ranges. Keratocytes of the stenothermal species continued to increase in speed as temperature increased above the species' normal temperature ranges. The thermal limits of keratocyte motility appear to exceed those of whole-organism thermal tolerance, notably in the case of T. bernacchii. Keratocytes of T. bernacchii survived supercooling to -6 degrees C and retained motility at temperatures as high as 20 degrees C. Mean keratocyte speed was conserved at physiological temperatures for the three temperate and tropical species, which suggests that a certain rate of motility is advantageous for wound healing. However, there was no temperature compensation in speed of movement for keratocytes of the Antarctic fish, which have extremely slow rates of movement at physiological temperatures. Keratocytes from all species moved in a persistent, unidirectional manner at low temperatures but at higher temperatures began to take more circular or less-persistent paths. Thermal acclimation affected the persistence and turning magnitude of keratocytes, with warmer acclimations generally yielding more persistent cells that followed straighter paths. However, acclimation did not alter the effect of experimental temperature on cellular speed. These findings suggest that more than one temperature-sensitive mechanism may govern cell motility: the rate-limiting process(es) responsible for speed is distinct from the mechanism(s) underlying directionality and persistence. Keratocytes represent a useful study system for evaluating the effects of temperature at the cellular level and for studying adaptive variation in actin-based cellular movement and capacity for wound healing.

Physiological, ecological, and behavioural correlates of the size of the geographic ranges of sea kraits (Laticauda; Elapidae, Serpentes): A critique

NASA Astrophysics Data System (ADS)

Heatwole, Harold; Lillywhite, Harvey; Grech, Alana

2016-09-01

Recent, more accurate delineation of the distributions of sea kraits and prior dubious use of proxy temperatures and mean values in correlative studies requires re-assessment of the relationships of temperature and salinity as determinants of the size of the geographic ranges of sea kraits. Correcting the sizes of geographic ranges resolved the paradox of lack of correspondence of size of range with degree of terrestrialism, but did not form a definitive test of the theory. Recent ecological, physiological, and behavioural studies provide an example of the kind of approach likely to either validate or refute present theory.

Increased anxiety and synaptic plasticity in estrogen receptor -deficient mice

NASA Astrophysics Data System (ADS)

Krel, Wojciech; Dupont, Sonia; Krust, Andrée; Chambon, Pierre; Chapman, Paul F.

2001-10-01

Estrogens are powerful modulators of neuronal physiology and in humans may affect a broad range of functions, including reproductive, emotional, and cognitive behaviors. We studied the contribution of estrogen receptors (ERs) in modulation of emotional processes and analyzed the effects of deleting ER or ER in mice. Behavior consistent with increased anxiety was observed principally in ER mutant females and was associated with a reduced threshold for the induction of synaptic plasticity in the basolateral amygdala. Local increase of 5-hydroxytryptamine 1a receptor expression inmedial amygdala may contribute to these changes. Our data show that, particularly in females, there is an important role for ERβ-mediated estrogen signaling in the processing of emotional behavior.

A comprehensive glossary of autophagy-related molecules and processes.

PubMed

Klionsky, Daniel J; Codogno, Patrice; Cuervo, Ana Maria; Deretic, Vojo; Elazar, Zvulun; Fueyo-Margareto, Juan; Gewirtz, David A; Kroemer, Guido; Levine, Beth; Mizushima, Noboru; Rubinsztein, David C; Thumm, Michael; Tooze, Sharon A

2010-05-01

Autophagy is a rapidly expanding field in the sense that our knowledge about the molecular mechanism and its connections to a wide range of physiological processes has increased substantially in the past decade. Similarly, the vocabulary associated with autophagy has grown concomitantly. This fact makes it difficult for readers, even those who work in the field, to keep up with the ever-expanding terminology associated with the various autophagy-related processes. Accordingly, we have developed a comprehensive glossary of autophagy-related terms that is meant to provide a quick reference for researchers who need a brief reminder of the regulatory effects of transcription factors or chemical agents that induce or inhibit autophagy, the function of the autophagy-related proteins, or the role of accessory machinery or structures that are associated with autophagy.

A comprehensive glossary of autophagy-related molecules and processes (2nd edition).

PubMed

Klionsky, Daniel J; Baehrecke, Eric H; Brumell, John H; Chu, Charleen T; Codogno, Patrice; Cuervo, Ana Marie; Debnath, Jayanta; Deretic, Vojo; Elazar, Zvulun; Eskelinen, Eeva-Liisa; Finkbeiner, Steven; Fueyo-Margareto, Juan; Gewirtz, David; Jäättelä, Marja; Kroemer, Guido; Levine, Beth; Melia, Thomas J; Mizushima, Noboru; Rubinsztein, David C; Simonsen, Anne; Thorburn, Andrew; Thumm, Michael; Tooze, Sharon A

2011-11-01

The study of autophagy is rapidly expanding, and our knowledge of the molecular mechanism and its connections to a wide range of physiological processes has increased substantially in the past decade. The vocabulary associated with autophagy has grown concomitantly. In fact, it is difficult for readers--even those who work in the field--to keep up with the ever-expanding terminology associated with the various autophagy-related processes. Accordingly, we have developed a comprehensive glossary of autophagy-related terms that is meant to provide a quick reference for researchers who need a brief reminder of the regulatory effects of transcription factors and chemical agents that induce or inhibit autophagy, the function of the autophagy-related proteins, and the roles of accessory components and structures that are associated with autophagy.

Psycho-physiological training approach for amputee rehabilitation.

PubMed

Dhal, Chandan; Wahi, Akshat

2015-01-01

Electromyography (EMG) signals are very noisy and difficult to acquire. Conventional techniques involve amplification and filtering through analog circuits, which makes the system very unstable. The surface EMG signals lie in the frequency range of 6Hz to 600Hz, and the dominant range is between the ranges from 20Hz to 150Hz. 1 Our project aimed to analyze an EMG signal effectively over its complete frequency range. To remove these defects, we designed what we think is an easy, effective, and reliable signal processing technique. We did spectrum analysis, so as to perform all the processing such as amplification, filtering, and thresholding on an Arduino Uno board, hence removing the need for analog amplifiers and filtering circuits, which have stability issues. The conversion of time domain to frequency domain of any signal gives a detailed data of the signal set. Our main aim is to use this useful data for an alternative methodology for rehabilitation called a psychophysiological approach to rehabilitation in prosthesis, which can reduce the cost of the myoelectric arm, as well as increase its efficiency. This method allows the user to gain control over their muscle sets in a less stressful environment. Further, we also have described how our approach is viable and can benefit the rehabilitation process. We used our DSP EMG signals to play an online game and showed how this approach can be used in rehabilitation.

A Physiologically Based Pharmacokinetic Model for Pregnant Women to Predict the Pharmacokinetics of Drugs Metabolized Via Several Enzymatic Pathways.

PubMed

Dallmann, André; Ince, Ibrahim; Coboeken, Katrin; Eissing, Thomas; Hempel, Georg

2017-09-18

Physiologically based pharmacokinetic modeling is considered a valuable tool for predicting pharmacokinetic changes in pregnancy to subsequently guide in-vivo pharmacokinetic trials in pregnant women. The objective of this study was to extend and verify a previously developed physiologically based pharmacokinetic model for pregnant women for the prediction of pharmacokinetics of drugs metabolized via several cytochrome P450 enzymes. Quantitative information on gestation-specific changes in enzyme activity available in the literature was incorporated in a pregnancy physiologically based pharmacokinetic model and the pharmacokinetics of eight drugs metabolized via one or multiple cytochrome P450 enzymes was predicted. The tested drugs were caffeine, midazolam, nifedipine, metoprolol, ondansetron, granisetron, diazepam, and metronidazole. Pharmacokinetic predictions were evaluated by comparison with in-vivo pharmacokinetic data obtained from the literature. The pregnancy physiologically based pharmacokinetic model successfully predicted the pharmacokinetics of all tested drugs. The observed pregnancy-induced pharmacokinetic changes were qualitatively and quantitatively reasonably well predicted for all drugs. Ninety-seven percent of the mean plasma concentrations predicted in pregnant women fell within a twofold error range and 63% within a 1.25-fold error range. For all drugs, the predicted area under the concentration-time curve was within a 1.25-fold error range. The presented pregnancy physiologically based pharmacokinetic model can quantitatively predict the pharmacokinetics of drugs that are metabolized via one or multiple cytochrome P450 enzymes by integrating prior knowledge of the pregnancy-related effect on these enzymes. This pregnancy physiologically based pharmacokinetic model may thus be used to identify potential exposure changes in pregnant women a priori and to eventually support informed decision making when clinical trials are designed in this special population.

Physiological correlates of mental workload

NASA Technical Reports Server (NTRS)

Zacharias, G. L.

1980-01-01

A literature review was conducted to assess the basis of and techniques for physiological assessment of mental workload. The study findings reviewed had shortcomings involving one or more of the following basic problems: (1) physiologic arousal can be easily driven by nonworkload factors, confounding any proposed metric; (2) the profound absence of underlying physiologic models has promulgated a multiplicity of seemingly arbitrary signal processing techniques; (3) the unspecified multidimensional nature of physiological "state" has given rise to a broad spectrum of competing noncommensurate metrics; and (4) the lack of an adequate definition of workload compels physiologic correlations to suffer either from the vagueness of implicit workload measures or from the variance of explicit subjective assessments. Using specific studies as examples, two basic signal processing/data reduction techniques in current use, time and ensemble averaging are discussed.

21 CFR 882.1845 - Physiological signal conditioner.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Physiological signal conditioner. 882.1845 Section... signal conditioner. (a) Identification. A physiological signal conditioner is a device such as an integrator or differentiator used to modify physiological signals for recording and processing. (b...

21 CFR 882.1845 - Physiological signal conditioner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Physiological signal conditioner. 882.1845 Section... signal conditioner. (a) Identification. A physiological signal conditioner is a device such as an integrator or differentiator used to modify physiological signals for recording and processing. (b...

Bioprocess development workflow: Transferable physiological knowledge instead of technological correlations.

PubMed

Reichelt, Wieland N; Haas, Florian; Sagmeister, Patrick; Herwig, Christoph

2017-01-01

Microbial bioprocesses need to be designed to be transferable from lab scale to production scale as well as between setups. Although substantial effort is invested to control technological parameters, usually the only true constant parameter is the actual producer of the product: the cell. Hence, instead of solely controlling technological process parameters, the focus should be increasingly laid on physiological parameters. This contribution aims at illustrating a workflow of data life cycle management with special focus on physiology. Information processing condenses the data into physiological variables, while information mining condenses the variables further into physiological descriptors. This basis facilitates data analysis for a physiological explanation for observed phenomena in productivity. Targeting transferability, we demonstrate this workflow using an industrially relevant Escherichia coli process for recombinant protein production and substantiate the following three points: (1) The postinduction phase is independent in terms of productivity and physiology from the preinduction variables specific growth rate and biomass at induction. (2) The specific substrate uptake rate during induction phase was found to significantly impact the maximum specific product titer. (3) The time point of maximum specific titer can be predicted by an easy accessible physiological variable: while the maximum specific titers were reached at different time points (19.8 ± 7.6 h), those maxima were reached all within a very narrow window of cumulatively consumed substrate dSn (3.1 ± 0.3 g/g). Concluding, this contribution provides a workflow on how to gain a physiological view on the process and illustrates potential benefits. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:261-270, 2017. © 2016 American Institute of Chemical Engineers.

Conceptual analysis of Physiology of vision in Ayurveda

PubMed Central

Balakrishnan, Praveen; Ashwini, M. J.

2014-01-01

The process by which the world outside is seen is termed as visual process or physiology of vision. There are three phases in this visual process: phase of refraction of light, phase of conversion of light energy into electrical impulse and finally peripheral and central neurophysiology. With the advent of modern instruments step by step biochemical changes occurring at each level of the visual process has been deciphered. Many investigations have emerged to track these changes and helping to diagnose the exact nature of the disease. Ayurveda has described this physiology of vision based on the functions of vata and pitta. Philosophical textbook of ayurveda, Tarka Sangraha, gives certain basics facts of visual process. This article discusses the second and third phase of visual process. Step by step analysis of the visual process through the spectacles of ayurveda amalgamated with the basics of philosophy from Tarka Sangraha has been analyzed critically to generate a concrete idea regarding the physiology and hence thereby interpret the pathology on the grounds of ayurveda based on the investigative reports. PMID:25336853

Can Computer-Based Visual-Spatial Aids Lead to Increased Student Performance in Anatomy & Physiology?

ERIC Educational Resources Information Center

Kesner, Michael H.; Linzey, Alicia V.

2005-01-01

InterActive Physiology (IAP) is one of a new generation of anatomy and physiology learning aids with a broader range of sensory inputs than is possible from a static textbook or moderately dynamic lecture. This best-selling software has modules covering the muscular, respiratory, urinary, cardiovascular, and nervous systems plus a module on fluids…

Smart Vest: wearable multi-parameter remote physiological monitoring system.

PubMed

Pandian, P S; Mohanavelu, K; Safeer, K P; Kotresh, T M; Shakunthala, D T; Gopal, Parvati; Padaki, V C

2008-05-01

The wearable physiological monitoring system is a washable shirt, which uses an array of sensors connected to a central processing unit with firmware for continuously monitoring physiological signals. The data collected can be correlated to produce an overall picture of the wearer's health. In this paper, we discuss the wearable physiological monitoring system called 'Smart Vest'. The Smart Vest consists of a comfortable to wear vest with sensors integrated for monitoring physiological parameters, wearable data acquisition and processing hardware and remote monitoring station. The wearable data acquisition system is designed using microcontroller and interfaced with wireless communication and global positioning system (GPS) modules. The physiological signals monitored are electrocardiogram (ECG), photoplethysmogram (PPG), body temperature, blood pressure, galvanic skin response (GSR) and heart rate. The acquired physiological signals are sampled at 250samples/s, digitized at 12-bit resolution and transmitted wireless to a remote physiological monitoring station along with the geo-location of the wearer. The paper describes a prototype Smart Vest system used for remote monitoring of physiological parameters and the clinical validation of the data are also presented.

Insights into the role of neuronal glucokinase.

PubMed

De Backer, Ivan; Hussain, Sufyan S; Bloom, Stephen R; Gardiner, James V

2016-07-01

Glucokinase is a key component of the neuronal glucose-sensing mechanism and is expressed in brain regions that control a range of homeostatic processes. In this review, we detail recently identified roles for neuronal glucokinase in glucose homeostasis and counterregulatory responses to hypoglycemia and in regulating appetite. We describe clinical implications from these advances in our knowledge, especially for developing novel treatments for diabetes and obesity. Further research required to extend our knowledge and help our efforts to tackle the diabetes and obesity epidemics is suggested. Copyright © 2016 the American Physiological Society.

Orphan Nuclear Receptors as Targets for Drug Development

PubMed Central

Mukherjee, Subhajit

2012-01-01

Orphan nuclear receptors regulate diverse biological processes. These important molecules are ligand-activated transcription factors that act as natural sensors for a wide range of steroid hormones and xenobiotic ligands. Because of their importance in regulating various novel signaling pathways, recent research has focused on identifying xenobiotics targeting these receptors for the treatment of multiple human diseases. In this review, we will highlight these receptors in several physiologic and pathophysiologic actions and demonstrate how their functions can be exploited for the successful development of newer drugs. PMID:20372994

Development of a simple intensified fermentation strategy for growth of Magnetospirillum gryphiswaldense MSR-1: Physiological responses to changing environmental conditions.

PubMed

Fernández-Castané, Alfred; Li, Hong; Thomas, Owen R T; Overton, Tim W

2018-06-01

The development of a simple pH-stat fed-batch fermentation strategy for the production of Magnetospirillum gryphiswaldense MSR-1 and magnetosomes (nanoscale magnetic organelles with biotechnological applications) is described. Flow cytometry was exploited as a powerful analytical tool for process development, enabling rapid monitoring of cell morphology, physiology and polyhydroxyalkanoate production. The pH-stat fed-batch growth strategy was developed by varying the concentrations of the carbon source (lactic acid) and the alternative electron acceptor (sodium nitrate) in the feed. Growth conditions were optimized on the basis of biomass concentration, cellular magnetism (indicative of magnetosome production), and intracellular iron concentration. The highest biomass concentration and cellular iron content achieved were an optical density at 565 nm of 15.5 (equivalent to 4.2 g DCW·L -1 ) and 33.1 mg iron·g -1 DCW, respectively. This study demonstrates the importance of analyzing bacterial physiology during fermentation development and will potentially aid the industrial production of magnetosomes, which can be used in a wide range of biotechnology and healthcare applications. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Effects on Physiology and Performance of Wearing the Aviator NBC ensemble While Flying the UH-60 Helicopter Flight Simulator in a Controlled Heat Environment.

DTIC Science & Technology

1992-09-01

and collecting and processing data. They were at the front line in interacting with the subjects and maintaining morale. They did an excellent job. They...second for 16 parameter channels, and the data were processed to produce a single root mean square (RMS) error value for each channel appropriate to...represented in the final analysis. Physiological data The physiological data on the VAX were processed by sampling them at 5-minute intervals throughout the

Integrating physiological regulation with stem cell and tissue homeostasis

PubMed Central

Nakada, Daisuke; Levi, Boaz P.; Morrison, Sean J.

2015-01-01

Summary Stem cells are uniquely able to self-renew, to undergo multilineage differentiation, and to persist throughout life in a number of tissues. Stem cells are regulated by a combination of shared and tissue-specific mechanisms and are distinguished from restricted progenitors by differences in transcriptional and epigenetic regulation. Emerging evidence suggests that other aspects of cellular physiology, including mitosis, signal transduction, and metabolic regulation also differ between stem cells and their progeny. These differences may allow stem cells to be regulated independently of differentiated cells in response to circadian rhythms, changes in metabolism, diet, exercise, mating, aging, infection, and disease. This allows stem cells to sustain homeostasis or to remodel relevant tissues in response to physiological change. Stem cells are therefore not only regulated by short-range signals that maintain homeostasis within their tissue of origin, but also by long-range signals that integrate stem cell function with systemic physiology. PMID:21609826

The Dendritic Cell Major Histocompatibility Complex II (MHC II) Peptidome Derives from a Variety of Processing Pathways and Includes Peptides with a Broad Spectrum of HLA-DM Sensitivity*

PubMed Central

Clement, Cristina C.; Becerra, Aniuska; Yin, Liusong; Zolla, Valerio; Huang, Liling; Merlin, Simone; Follenzi, Antonia; Shaffer, Scott A.; Stern, Lawrence J.; Santambrogio, Laura

2016-01-01

The repertoire of peptides displayed in vivo by MHC II molecules derives from a wide spectrum of proteins produced by different cell types. Although intracellular endosomal processing in dendritic cells and B cells has been characterized for a few antigens, the overall range of processing pathways responsible for generating the MHC II peptidome are currently unclear. To determine the contribution of non-endosomal processing pathways, we eluted and sequenced over 3000 HLA-DR1-bound peptides presented in vivo by dendritic cells. The processing enzymes were identified by reference to a database of experimentally determined cleavage sites and experimentally validated for four epitopes derived from complement 3, collagen II, thymosin β4, and gelsolin. We determined that self-antigens processed by tissue-specific proteases, including complement, matrix metalloproteases, caspases, and granzymes, and carried by lymph, contribute significantly to the MHC II self-peptidome presented by conventional dendritic cells in vivo. Additionally, the presented peptides exhibited a wide spectrum of binding affinity and HLA-DM susceptibility. The results indicate that the HLA-DR1-restricted self-peptidome presented under physiological conditions derives from a variety of processing pathways. Non-endosomal processing enzymes add to the number of epitopes cleaved by cathepsins, altogether generating a wider peptide repertoire. Taken together with HLA-DM-dependent and-independent loading pathways, this ensures that a broad self-peptidome is presented by dendritic cells. This work brings attention to the role of “self-recognition” as a dynamic interaction between dendritic cells and the metabolic/catabolic activities ongoing in every parenchymal organ as part of tissue growth, remodeling, and physiological apoptosis. PMID:26740625

Bovine somatotropin and lactation: from basic science to commercial application.

PubMed

Bauman, D E

1999-10-01

Bovine somatotropin (bST) results in increased milk yield and an unprecedented improvement in efficiency. Beginning in the 1930s to present day, investigations have examined animal-related factors such as nutrition, bioenergetics, metabolism, health and well being and consumer-related factors such as milk quality, manufacturing characteristics, and product safety. Overall, bST is a homeorhetic control involved in orchestrating many physiological processes. Direct effects involve adaptations in many tissues and the metabolism of all nutrient classes--carbohydrates, lipids, protein, and minerals. Mechanisms include alterations in key enzymes, intracellular signal transduction systems, and tissue response to homeostatic signals. Indirect effects involve the mammary gland and are thought to be mediated by the insulin-like growth factor (IGF) system. Specific changes include increased cellular rates of milk synthesis and enhanced maintenance of secretory cells. Indirect effects are modulated by environment and management factors, especially nutritional status. This modulation is a central component in allowing ST to play a key role in regulating nutrient utilization across a range of physiological situations. U.S. commercial use began in 1994, and adoption has been extensive. From a consumer perspective, bST was unique, and special interest groups loudly predicted dire consequences. However, introduction of bST had no impact on milk consumption, and milk labeled as recombinant bST-free occupies a minor niche market. From a producer perspective, commercial use verified scientific studies and enhanced net farm income. Overall, ST is a key homeorhetic control regulating nutrient partitioning, and the ST/IGF system plays a key role in animal performance and well being across a range of physiological situations.

First-Year Medical Students' Naïve Beliefs about Respiratory Physiology

ERIC Educational Resources Information Center

Badenhorst, Elmi; Mamede, Silvia; Abrahams, Amaal; Bugarith, Kishor; Friedling, Jacqui; Gunston, Geney; Kelly-Laubscher, Roisin; Schmidt, Henk G.

2016-01-01

The present study explored the nature and frequency of physiology naïve beliefs by investigating novices' understanding of the respiratory system. Previous studies have shown considerable misconceptions related to physiology but focused mostly on specific physiological processes of normal respiration. Little is known about novices' broader…

Novel climates reverse carbon uptake of atmospherically dependent epiphytes: Climatic constraints on the iconic boreal forest lichen Evernia mesomorpha.

PubMed

Smith, Robert J; Nelson, Peter R; Jovan, Sarah; Hanson, Paul J; McCune, Bruce

2018-02-01

Changing climates are expected to affect the abundance and distribution of global vegetation, especially plants and lichens with an epiphytic lifestyle and direct exposure to atmospheric variation. The study of epiphytes could improve understanding of biological responses to climatic changes, but only if the conditions that elicit physiological performance changes are clearly defined. We evaluated individual growth performance of the epiphytic lichen Evernia mesomorpha, an iconic boreal forest indicator species, in the first year of a decade-long experiment featuring whole-ecosystem warming and drying. Field experimental enclosures were located near the southern edge of the species' range. Mean annual biomass growth of Evernia significantly declined 6 percentage points for every +1°C of experimental warming after accounting for interactions with atmospheric drying. Mean annual biomass growth was 14% in ambient treatments, 2% in unheated control treatments, and -9% to -19% (decreases) in energy-added treatments ranging from +2.25 to +9.00°C above ambient temperatures. Warming-induced biomass losses among persistent individuals were suggestive evidence of an extinction debt that could precede further local mortality events. Changing patterns of warming and drying would decrease or reverse Evernia growth at its southern range margins, with potential consequences for the maintenance of local and regional populations. Negative carbon balances among persisting individuals could physiologically commit these epiphytes to local extinction. Our findings illuminate the processes underlying local extinctions of epiphytes and suggest broader consequences for range shrinkage if dispersal and recruitment rates cannot keep pace. © 2018 Botanical Society of America.

Novel climates reverse carbon uptake of atmospherically dependent epiphytes: Climatic constraints on the iconic boreal forest lichen Evernia mesomorpha

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

Smith, Robert J.; Nelson, Peter R.; Jovan, Sarah

Premise of the Study: Changing climates are expected to affect the abundance and distribution of global vegetation, especially plants and lichens with an epiphytic lifestyle and direct exposure to atmospheric variation. The study of epiphytes could improve understanding of biological responses to climatic changes, but only if the conditions that elicit physiological performance changes are clearly defined.Methods: We evaluated individual growth performance of the epiphytic lichen Evernia mesomorpha, an iconic boreal forest indicator species, in the first year of a decade-long experiment featuring whole-ecosystem warming and drying. Field experimental enclosures were located near the southern edge of the species’ range.Keymore » Results: Mean annual biomass growth of Evernia significantly declined 6 percentage points for every +1°C of experimental warming after accounting for interactions with atmospheric drying. Mean annual biomass growth was 14% in ambient treatments, 2% in unheated control treatments, and -9% to -19% (decreases) in energy-added treatments ranging from +2.25 to +9.00°C above ambient temperatures. Warming-induced biomass losses among persistent individuals were suggestive evidence of an extinction debt that could precede further local mortality events.Conclusions: Changing patterns of warming and drying would decrease or reverse Evernia growth at its southern range margins, with potential consequences for the maintenance of local and regional populations. Negative carbon balances among persisting individuals could physiologically commit these epiphytes to local extinction. Our findings illuminate the processes underlying local extinctions of epiphytes and suggest broader consequences for range shrinkage if dispersal and recruitment rates cannot keep pace.« less

Optimal physiological structure of small neurons to guarantee stable information processing

NASA Astrophysics Data System (ADS)

Zeng, S. Y.; Zhang, Z. Z.; Wei, D. Q.; Luo, X. S.; Tang, W. Y.; Zeng, S. W.; Wang, R. F.

2013-02-01

Spike is the basic element for neuronal information processing and the spontaneous spiking frequency should be less than 1 Hz for stable information processing. If the neuronal membrane area is small, the frequency of neuronal spontaneous spiking caused by ion channel noise may be high. Therefore, it is important to suppress the deleterious spontaneous spiking of the small neurons. We find by simulation of stochastic neurons with Hodgkin-Huxley-type channels that the leakage system is critical and extremely efficient to suppress the spontaneous spiking and guarantee stable information processing of the small neurons. However, within the physiological limit the potassium system cannot do so. The suppression effect of the leakage system is super-exponential, but that of the potassium system is quasi-linear. With the minor physiological cost and the minimal consumption of metabolic energy, a slightly lower reversal potential and a relatively larger conductance of the leakage system give the optimal physiological structure to suppress the deleterious spontaneous spiking and guarantee stable information processing of small neurons, dendrites and axons.

High-dynamic-range scene compression in humans

NASA Astrophysics Data System (ADS)

McCann, John J.

2006-02-01

Single pixel dynamic-range compression alters a particular input value to a unique output value - a look-up table. It is used in chemical and most digital photographic systems having S-shaped transforms to render high-range scenes onto low-range media. Post-receptor neural processing is spatial, as shown by the physiological experiments of Dowling, Barlow, Kuffler, and Hubel & Wiesel. Human vision does not render a particular receptor-quanta catch as a unique response. Instead, because of spatial processing, the response to a particular quanta catch can be any color. Visual response is scene dependent. Stockham proposed an approach to model human range compression using low-spatial frequency filters. Campbell, Ginsberg, Wilson, Watson, Daly and many others have developed spatial-frequency channel models. This paper describes experiments measuring the properties of desirable spatial-frequency filters for a variety of scenes. Given the radiances of each pixel in the scene and the observed appearances of objects in the image, one can calculate the visual mask for that individual image. Here, visual mask is the spatial pattern of changes made by the visual system in processing the input image. It is the spatial signature of human vision. Low-dynamic range images with many white areas need no spatial filtering. High-dynamic-range images with many blacks, or deep shadows, require strong spatial filtering. Sun on the right and shade on the left requires directional filters. These experiments show that variable scene- scenedependent filters are necessary to mimic human vision. Although spatial-frequency filters can model human dependent appearances, the problem still remains that an analysis of the scene is still needed to calculate the scene-dependent strengths of each of the filters for each frequency.

Neuroendocrine tumor imaging with 68Ga-DOTA-NOC: physiologic and benign variants.

PubMed

Kagna, Olga; Pirmisashvili, Natalia; Tshori, Sagi; Freedman, Nanette; Israel, Ora; Krausz, Yodphat

2014-12-01

Imaging with (68)Ga-labeled 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-octreotide analogs has become an important modality in patients with neuroendocrine tumors (NETs). In addition to high uptake in NET lesions, prominent physiologic radiotracer activity has been reported in the pituitary gland, pancreas, adrenal glands, liver, and spleen, and faint activity has been reported in the thyroid and gastrointestinal tract. This article describes previously unknown sites of 68Ga-DOTA-1-NaI3-octreotide (NOC) uptake unrelated to NETs. One hundred eighty-two patients (96 female and 86 male patients; age range, 4-89 years) with documented (n=156) or suspected (n=26) NETs underwent 207 68Ga-DOTA-NOC PET/CT studies. Studies were retrospectively reviewed for the presence, intensity, and localization of foci of increased uptake that were further correlated with findings on additional imaging studies and clinical follow-up for a period of 4-32 months. Uptake of 68Ga-DOTA-NOC not identified as NET or known physiologic activity was detected in 297 sites with confirmation in 149 of 207 studies (72%). The most common location of non-NET-related 68Ga-DOTA-NOC-avid sites was in small lymph nodes, followed by prostate, uterus, breasts, lungs, brown fat, musculoskeletal system, and other sites, including oropharynx, pineal body, thymus, aortic plaque, genitalia, surgical bed, and subcutaneous granuloma. Intensity of uptake in non-NET-related 68Ga-DOTA-NOC-avid sites ranged in maximum standardized uptake value from 0.8 to 10.5. Previously unreported benign sites of 68Ga-DOTA-NOC uptake were found in the majority of studies, suggesting the presence of somatostatin receptors in physiologic variants or processes with no evidence of tumor. Knowledge of increased tracer uptake in non-NET-related sites is important for accurate interpretation and for avoiding potential pitfalls of 68Ga-DOTA-NOC PET/CT.

The development of contour processing: evidence from physiology and psychophysics

PubMed Central

Taylor, Gemma; Hipp, Daniel; Moser, Alecia; Dickerson, Kelly; Gerhardstein, Peter

2014-01-01

Object perception and pattern vision depend fundamentally upon the extraction of contours from the visual environment. In adulthood, contour or edge-level processing is supported by the Gestalt heuristics of proximity, collinearity, and closure. Less is known, however, about the developmental trajectory of contour detection and contour integration. Within the physiology of the visual system, long-range horizontal connections in V1 and V2 are the likely candidates for implementing these heuristics. While post-mortem anatomical studies of human infants suggest that horizontal interconnections reach maturity by the second year of life, psychophysical research with infants and children suggests a considerably more protracted development. In the present review, data from infancy to adulthood will be discussed in order to track the development of contour detection and integration. The goal of this review is thus to integrate the development of contour detection and integration with research regarding the development of underlying neural circuitry. We conclude that the ontogeny of this system is best characterized as a developmentally extended period of associative acquisition whereby horizontal connectivity becomes functional over longer and longer distances, thus becoming able to effectively integrate over greater spans of visual space. PMID:25071681

Exploration of a physiologically-inspired hearing-aid algorithm using a computer model mimicking impaired hearing.

PubMed

Jürgens, Tim; Clark, Nicholas R; Lecluyse, Wendy; Meddis, Ray

2016-01-01

To use a computer model of impaired hearing to explore the effects of a physiologically-inspired hearing-aid algorithm on a range of psychoacoustic measures. A computer model of a hypothetical impaired listener's hearing was constructed by adjusting parameters of a computer model of normal hearing. Absolute thresholds, estimates of compression, and frequency selectivity (summarized to a hearing profile) were assessed using this model with and without pre-processing the stimuli by a hearing-aid algorithm. The influence of different settings of the algorithm on the impaired profile was investigated. To validate the model predictions, the effect of the algorithm on hearing profiles of human impaired listeners was measured. A computer model simulating impaired hearing (total absence of basilar membrane compression) was used, and three hearing-impaired listeners participated. The hearing profiles of the model and the listeners showed substantial changes when the test stimuli were pre-processed by the hearing-aid algorithm. These changes consisted of lower absolute thresholds, steeper temporal masking curves, and sharper psychophysical tuning curves. The hearing-aid algorithm affected the impaired hearing profile of the model to approximate a normal hearing profile. Qualitatively similar results were found with the impaired listeners' hearing profiles.

Separation of aflatoxin B1 from synthetic physiological fluids using talc and diatomite: Kinetic and isotherm aspects.

PubMed

Sprynskyy, Myroslav; Krzemień-Konieczka, Iwona; Gadzała-Kopciuch, Renata; Buszewski, Bogusław

2018-01-01

The objective of the study was to examine adsorption of the aflatoxin B1 from synthetic gastric fluid and synthetic intestinal fluid by talc, raw and calcined diatomite. The kinetic and equilibrium adsorption processes were studied in the batch adsorption experiments applying high performance liquid chromatography for the aflatoxin B1 determination. The kinetic study showed a very fast adsorption of the aflatoxin B1 onto the selected adsorbents from the both physiological fluids with reaching equilibrium within 1-15min. The aflatoxin B1 was almost completely adsorbed in initial linear step of the kinetic process that can be described well by the zero-order kinetics model. The experimental data of the equilibrium adsorption were characterized using the Langmuir and Freundlich isotherm models. The high adsorption effectiveness was found in a range of 90%-100% and 60%-100% for the diatomite samples and the talc respectively at the initial concentrations of the aflatoxin B1 as 31-300ng/mL. The possible mechanisms of the aflatoxin adsorption onto the used mineral adsorbents are also discussed in the work. Copyright © 2017 Elsevier B.V. All rights reserved.

Effort Deficits and Depression: The Influence of Anhedonic Depressive Symptoms on Cardiac Autonomic Activity During a Mental Challenge

PubMed Central

Silvia, Paul J.; Nusbaum, Emily C.; Eddington, Kari M.; Beaty, Roger E.; Kwapil, Thomas R.

2014-01-01

Motivational approaches to depression emphasize the role of dysfunctional motivational dynamics, particularly diminished reward and incentive processes associated with anhedonia. A study examined how anhedonic depressive symptoms, measured continuously across a wide range of severity, influenced the physiological mobilization of effort during a cognitive task. Using motivational intensity theory as a guide, we expected that the diminished incentive value associated with anhedonic depressive symptoms would reduce effort during a “do your best” challenge (also known as an unfixed or self-paced challenge), in which effort is a function of the value of achieving the task’s goal. Using impedance cardiography, two cardiac autonomic responses were assessed: pre-ejection period (PEP), a measure of sympathetic activity and our primary measure of interest, and respiratory sinus arrhythmia (RSA), a measure of parasympathetic activity. As expected, PEP slowed from baseline to task as anhedonic depressive symptoms increased (as measured with the DASS Depression scale), indicating diminished effort-related sympathetic activity. No significant effects appeared for RSA. The findings support motivational intensity theory as a translational model of effort processes in depression and clarify some inconsistent effects of depressive symptoms on effort-related physiology found in past work. PMID:25431505

Developmental model of static allometry in holometabolous insects.

PubMed

Shingleton, Alexander W; Mirth, Christen K; Bates, Peter W

2008-08-22

The regulation of static allometry is a fundamental developmental process, yet little is understood of the mechanisms that ensure organs scale correctly across a range of body sizes. Recent studies have revealed the physiological and genetic mechanisms that control nutritional variation in the final body and organ size in holometabolous insects. The implications these mechanisms have for the regulation of static allometry is, however, unknown. Here, we formulate a mathematical description of the nutritional control of body and organ size in Drosophila melanogaster and use it to explore how the developmental regulators of size influence static allometry. The model suggests that the slope of nutritional static allometries, the 'allometric coefficient', is controlled by the relative sensitivity of an organ's growth rate to changes in nutrition, and the relative duration of development when nutrition affects an organ's final size. The model also predicts that, in order to maintain correct scaling, sensitivity to changes in nutrition varies among organs, and within organs through time. We present experimental data that support these predictions. By revealing how specific physiological and genetic regulators of size influence allometry, the model serves to identify developmental processes upon which evolution may act to alter scaling relationships.

Wall Shear Stress Distribution in a Patient-Specific Cerebral Aneurysm Model using Reduced Order Modeling

NASA Astrophysics Data System (ADS)

Han, Suyue; Chang, Gary Han; Schirmer, Clemens; Modarres-Sadeghi, Yahya

2016-11-01

We construct a reduced-order model (ROM) to study the Wall Shear Stress (WSS) distributions in image-based patient-specific aneurysms models. The magnitude of WSS has been shown to be a critical factor in growth and rupture of human aneurysms. We start the process by running a training case using Computational Fluid Dynamics (CFD) simulation with time-varying flow parameters, such that these parameters cover the range of parameters of interest. The method of snapshot Proper Orthogonal Decomposition (POD) is utilized to construct the reduced-order bases using the training CFD simulation. The resulting ROM enables us to study the flow patterns and the WSS distributions over a range of system parameters computationally very efficiently with a relatively small number of modes. This enables comprehensive analysis of the model system across a range of physiological conditions without the need to re-compute the simulation for small changes in the system parameters.

[The Influence of Different Ionic Concentration in Cell Physiological Solution on Temperature Measurement by Near Infrared].

PubMed

Zheng, Yu; Chen, Xiong; Zhou, Mei; Wang, Meng-jun; Wang, Jin-hai; Li, Gang; Cui, Jun

2015-10-01

It is important to real-timely monitor and control the temperature of cell physiological solution in patch clamp experiments, which can eliminate the uncertainty due to temperature and improve the measurement accuracy. This paper studies the influence of different ions at different concentrations in the physiological solution on precision of a temperature model by using near infrared spectroscopy and chemometrics method. Firstly, we prepared twelve sample solutions respectively with the solutes of CaCl2, KCl and NaCl at four kinds of concentrations, and collected the spectra of different solutions at the setting temperature range 20-40 degrees C, the range of the spectra is 9 615-5 714 cm(-1). Then we divided the spectra of each solution at different temperatures into two parts (a training set and a prediction set) by three methods. Interval partial least squares method was used to select an effective wavelength range and develop calibration models between the spectra in the selected range and temperature velues. The experimental results show that RMSEP of CaCl2 solution with 0.25 g x mL(-1) is maximum, the result of the three tests are 0.386 3, 0.303 7 and 0.337 2 degrees C, RMSEP of NaCl with 0.005 g x mL(-1) solution is minimum, the result of the three tests are 0.220 8, 0.155 3 and 0.145 2 degrees C. The experimental results indicate that Ca2+ has the greatest influence on the accuracy of the temperature model of the cell physiological solution, then K+, and Na+ has the least influence. And with the ionic concentration increasing, the model accuracy decreases. Therefore; when we build the temperature model of cell physiological solution, it is necessary to change the proportion of the three kinds of main ions in cell physiological solution reasonably in order to correct the effects of different ionic concentrations in physiological solution and improve the accuracy of temperature measurements by near infrared spectroscopy.

Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications

NASA Astrophysics Data System (ADS)

Grochowska, Katarzyna; Siuzdak, Katarzyna; Karczewski, Jakub; Śliwiński, Gerard

2015-12-01

The production and properties of the indium-tin-oxide (ITO) electrodes functionalized by Au nanoparticle (NP) arrays of a relatively large area formed by pulsed laser nanostructuring of thin gold films are reported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearly spherical and disc-shaped particles of dimensions in the range of 40-120 nm. The NP-array geometry can be controlled by selection of the laser processing conditions. It is shown that particle size and packing density of the array are important factors which determine the electrode performance. In the case of NP-modified electrodes the peak current corresponding to the glucose direct oxidation process shows rise with increasing glucose concentration markedly higher comparing to the reference Au disc electrode. The detection limit reaches 12 μM and linear response of the sensor is observed from 0.1 to 47 mM that covers the normal physiological range of the blood sugar detection.

Synaptic dynamics contribute to long-term single neuron response fluctuations.

PubMed

Reinartz, Sebastian; Biro, Istvan; Gal, Asaf; Giugliano, Michele; Marom, Shimon

2014-01-01

Firing rate variability at the single neuron level is characterized by long-memory processes and complex statistics over a wide range of time scales (from milliseconds up to several hours). Here, we focus on the contribution of non-stationary efficacy of the ensemble of synapses-activated in response to a given stimulus-on single neuron response variability. We present and validate a method tailored for controlled and specific long-term activation of a single cortical neuron in vitro via synaptic or antidromic stimulation, enabling a clear separation between two determinants of neuronal response variability: membrane excitability dynamics vs. synaptic dynamics. Applying this method we show that, within the range of physiological activation frequencies, the synaptic ensemble of a given neuron is a key contributor to the neuronal response variability, long-memory processes and complex statistics observed over extended time scales. Synaptic transmission dynamics impact on response variability in stimulation rates that are substantially lower compared to stimulation rates that drive excitability resources to fluctuate. Implications to network embedded neurons are discussed.

A neural model of hierarchical reinforcement learning.

PubMed

Rasmussen, Daniel; Voelker, Aaron; Eliasmith, Chris

2017-01-01

We develop a novel, biologically detailed neural model of reinforcement learning (RL) processes in the brain. This model incorporates a broad range of biological features that pose challenges to neural RL, such as temporally extended action sequences, continuous environments involving unknown time delays, and noisy/imprecise computations. Most significantly, we expand the model into the realm of hierarchical reinforcement learning (HRL), which divides the RL process into a hierarchy of actions at different levels of abstraction. Here we implement all the major components of HRL in a neural model that captures a variety of known anatomical and physiological properties of the brain. We demonstrate the performance of the model in a range of different environments, in order to emphasize the aim of understanding the brain's general reinforcement learning ability. These results show that the model compares well to previous modelling work and demonstrates improved performance as a result of its hierarchical ability. We also show that the model's behaviour is consistent with available data on human hierarchical RL, and generate several novel predictions.

Hyperspectral remote sensing of plant pigments.

PubMed

Blackburn, George Alan

2007-01-01

The dynamics of pigment concentrations are diagnostic of a range of plant physiological properties and processes. This paper appraises the developing technologies and analytical methods for quantifying pigments non-destructively and repeatedly across a range of spatial scales using hyperspectral remote sensing. Progress in deriving predictive relationships between various characteristics and transforms of hyperspectral reflectance data are evaluated and the roles of leaf and canopy radiative transfer models are reviewed. Requirements are identified for more extensive intercomparisons of different approaches and for further work on the strategies for interpreting canopy scale data. The paper examines the prospects for extending research to the wider range of pigments in addition to chlorophyll, testing emerging methods of hyperspectral analysis and exploring the fusion of hyperspectral and LIDAR remote sensing. In spite of these opportunities for further development and the refinement of techniques, current evidence of an expanding range of applications in the ecophysiological, environmental, agricultural, and forestry sciences highlights the growing value of hyperspectral remote sensing of plant pigments.

Interoception and stress

PubMed Central

Schulz, André; Vögele, Claus

2015-01-01

Afferent neural signals are continuously transmitted from visceral organs to the brain. Interoception refers to the processing of visceral-afferent neural signals by the central nervous system, which can finally result in the conscious perception of bodily processes. Interoception can, therefore, be described as a prominent example of information processing on the ascending branch of the brain–body axis. Stress responses involve a complex neuro-behavioral cascade, which is elicited when the organism is confronted with a potentially harmful stimulus. As this stress cascade comprises a range of neural and endocrine pathways, stress can be conceptualized as a communication process on the descending branch of the brain–body axis. Interoception and stress are, therefore, associated via the bi-directional transmission of information on the brain–body axis. It could be argued that excessive and/or enduring activation (e.g., by acute or chronic stress) of neural circuits, which are responsible for successful communication on the brain–body axis, induces malfunction and dysregulation of these information processes. As a consequence, interoceptive signal processing may be altered, resulting in physical symptoms contributing to the development and/or maintenance of body-related mental disorders, which are associated with stress. In the current paper, we summarize findings on psychobiological processes underlying acute and chronic stress and their interaction with interoception. While focusing on the role of the physiological stress axes (hypothalamic-pituitary-adrenocortical axis and autonomic nervous system), psychological factors in acute and chronic stress are also discussed. We propose a positive feedback model involving stress (in particular early life or chronic stress, as well as major adverse events), the dysregulation of physiological stress axes, altered perception of bodily sensations, and the generation of physical symptoms, which may in turn facilitate stress. PMID:26257668

Physiological asymmetry of trunk ranging and pelvis motility: an anatomo-functional study in 80 healthy subjects.

PubMed

Macchi, Claudio; Biricolti, Claudia; Cappelli, Lorenza; Galli, Francesca; Molino-Lova, Raffaele; Cecchi, Francesca; Corigliano, Alvaro; Miniati, Benedetta; Conti, Andrea A; Gulisano, Massimo; Catini, Claudio; Gensini, Gian Franco

2002-01-01

A key feature in physiotherapeutic treatment of patients with motion disturbances is the appropriate ranging of the trunk and pelvis motility. Eighty subjects randomly selected and free from known pathology of the muscular-skeletal and/or of the neurological system classed into four groups according to the age and the sex have been assessed, by using a new, simple and easy administrable tool. Our results demonstrate that the new measurement tool showed a very low intra- and inter-observer variability, that healthy subjects showed a more adduced and elevated right scapula if compared to the contralateral one and, as regard as the pelvic motion, a broader joint excursion in passive motion compared with active motion in the overall group, a broader joint excursion in young subjects compared with elderly ones, and a broader joint excursion in female subjects compared with males subjects. In conclusion our study allowed to identify a range of physiological asymmetry and pelvis motility. Such a range of physiological asymmetry might be useful as a reference for the physiotherapists.

Mg-isotopic fractionation in the manila clam (Ruditapes philippinarum): New insights into Mg incorporation pathway and calcification process of bivalves

NASA Astrophysics Data System (ADS)

Planchon, Frédéric; Poulain, Céline; Langlet, Denis; Paulet, Yves-Marie; André, Luc

2013-11-01

We estimate the magnesium stable isotopic composition (δ26Mg) of the major compartments involved in the biomineralisation process of euryhaline bivalve, the manila clam Ruditapes philippinarum. Our aim is to identify the fractionation processes associated with Mg uptake and its cycling/transport in the bivalve organism, in order to better assess the controlling factors of the Mg isotopic records in bivalve shells. δ26Mg were determined in seawater, in hemolymph, extrapallial fluid (EPF), soft tissues and aragonitic shell of adult clams collected along the Auray River estuary (Gulf of Morbihan, France) at two sites showing contrasted salinity regimes. The large overall δ26Mg variations (4.16‰) demonstrate that significant mass-dependent Mg isotopic fractionations occur during Mg transfer from seawater to the aragonitic shell. Soft tissues span a range of fractionation factors relative to seawater (Δ26Mgsoft tissue-seawater) of 0.42 ± 0.12‰ to 0.76 ± 0.12‰, and show evidence for biological isotopic fractionation of Mg. Hemolymph and EPF are on average isotopically close to seawater (Δ26Mghemolymph-seawater = -0.20 ± 0.27‰; 2 sd; n = 5 and Δ26MgEPF-seawater = -0.23 ± 0.25‰; 2 sd; n = 5) indicating (1) a predominant seawater origin for Mg in the intercellular medium and (2) a relatively passive transfer route through the bivalve organism into the calcifying fluid. The lightest isotopic composition is found in shell, with δ26Mg ranging from -1.89 ± 0.07‰ to -4.22 ± 0.06‰. This range is the largest in the dataset and is proposed to result from a combination of abiotic and biologically-driven fractionation processes. Abiotic control includes fractionation during precipitation of aragonite and accounts for Δ26Mgaragonite-seawater ≈ 1000 ln αaragonite-seawater = -1.13 ± 0.28‰ at 20 °C based on literature data. Deviations from inorganic precipitate (expressed as Δ26MgPhysiol) appear particularly variable in the clam shell, ranging from 0.03‰ to -2.20‰, which indicates that bivalve shell formation can proceed either under fractionation similar to inorganically-precipitated aragonite or under variable physiological influences. These physiological isotopic effects may be consistent with a regulation of dissolved Mg content in hemolymph and/or EPF due to Mg incorporation into soft tissue and/or Mg fixation by organic macromolecules. Using closed- and open-system models we estimate that Δ26MgPhysiol can be satisfactorily resolved with a remaining Mg fraction in hemolymph and/or EPF of 74% down to 2%. However, this feature is not reflected in our hemolymph and EPF data and may indicate that regulation processes and isotopic fractionation may take place in self-contained spaces located close to calcification sites. The potential role of the shell organic matrix, which may host non-lattice-bound Mg in the shell, is also discussed but remains difficult to assess with our data. Regarding the large physiological effects, the δ26Mg record in the Manila clam shell offers limited potential as a proxy of temperature or seawater Mg isotopic composition. In contrast, the sensitivity of its δ26Mg to the salinity regime may offer an interesting tool to track changes in clam biological activity in estuarine environments.

Design of a framework for modeling, integration and simulation of physiological models.

PubMed

Erson, E Zeynep; Cavuşoğlu, M Cenk

2012-09-01

Multiscale modeling and integration of physiological models carry challenges due to the complex nature of physiological processes. High coupling within and among scales present a significant challenge in constructing and integrating multiscale physiological models. In order to deal with such challenges in a systematic way, there is a significant need for an information technology framework together with related analytical and computational tools that will facilitate integration of models and simulations of complex biological systems. Physiological Model Simulation, Integration and Modeling Framework (Phy-SIM) is an information technology framework providing the tools to facilitate development, integration and simulation of integrated models of human physiology. Phy-SIM brings software level solutions to the challenges raised by the complex nature of physiological systems. The aim of Phy-SIM, and this paper is to lay some foundation with the new approaches such as information flow and modular representation of the physiological models. The ultimate goal is to enhance the development of both the models and the integration approaches of multiscale physiological processes and thus this paper focuses on the design approaches that would achieve such a goal. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Intergenerational Transmission of Aggression: Physiological Regulatory Processes

PubMed Central

Margolin, Gayla; Ramos, Michelle C.; Timmons, Adela C.; Miller, Kelly F.; Han, Sohyun C.

2015-01-01

Children who grow up in aggressive households are at risk of having problems with physiological regulation, but researchers have not investigated physiology as a mechanism in the intergenerational transmission of aggression. In this article, we posit that physiological regulation, particularly during stressful interpersonal interactions, may shed light on sensitivity to conflict, It can also inform our understanding of associations between childhood exposure to aggression in families of origin and aggression against partners in adolescence or adulthood. In support of this model, we highlight findings showing that childhood exposure to family aggression relates to physiological regulation across the life span, and that reactions to physiological stress concurrently relate to aggression against intimate partners. Emerging evidence from research on biological processes during stressful interpersonal interactions raises questions about what is adaptive for individuals from aggressive families, particularly as past family experiences intersect with the challenges of new relationships. PMID:26929773

Use of concept mapping in an undergraduate introductory exercise physiology course.

PubMed

Henige, Kim

2012-09-01

Physiology is often considered a challenging course for students. It is up to teachers to structure courses and create learning opportunities that will increase the chance of student success. In an undergraduate exercise physiology course, concept maps are assigned to help students actively process and organize information into manageable and meaningful chunks and to teach them to recognize the patterns and regularities of physiology. Students are first introduced to concept mapping with a commonly relatable nonphysiology concept and are then assigned a series of maps that become more and more complex. Students map the acute response to a drop in blood pressure, the causes of the acute increase in stroke volume during cardiorespiratory exercise, and the factors contributing to an increase in maximal O(2) consumption with cardiorespiratory endurance training. In the process, students draw the integrative nature of physiology, identify causal relationships, and learn about general models and core principles of physiology.

Neutral temperature range in incubators: performance of equipment in current use and new developments.

PubMed

Libert, J P; Bach, V; Farges, G

1997-01-01

Low-birth-weight neonates should be nursed at thermoneutrality inside incubators. Thermoneutrality control is essential to enhance body growth and to reduce neonatal illnesses and mortality. Guidelines have been published to provide the thermoneutral range, but the recommendations did not always take into account all ambient and physiological parameters influencing thermoneutrality. In most marketed incubators, the heat supply is controlled through convective air flow (closed incubators) or through radiant power density (radiant warmer beds). The heating unit (on/off cycling or adjustable proportional control) is activated by an error signal calculated from the difference between a controlled temperature and a reference value preset by the clinician. The controlled variable can be either the incubator air or the skin temperature of the anterior abdominal region of the neonate. The neonate's size, thermal properties of the mattress and of incubator walls, air temperature and humidity, air velocity, incubator wall temperatures all influence the heat exchanges between the neonate and the surroundings, and, consequently, modify the obtention of thermoneutrality. Moreover, studies of the physiological mechanisms by which the neonate regulates body heat storage suggest that metabolic rate, behavior, vigilance level, nursing care, and heater control processes should also be taken into account. Little attention has been paid to these factors, and incubator performances are often disappointing. This article reviews the different factors that modify thermoneutral condition. An attempt is made to suggest new ways to design equipment incorporating these factors in algorithms controlling heater processes in order to reach the optimal thermal environment in which the neonate should be nursed.

Quantification of angiotensin-converting-enzyme-mediated degradation of human chemerin 145-154 in plasma by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry.

PubMed

John, Harald; Hierer, Jessica; Haas, Olga; Forssmann, Wolf-Georg

2007-03-01

Chemerin is a chemoattractive protein acting as a ligand for the G-protein-coupled receptor ChemR23/CMKLR1 and plays an important role in the innate and adaptive immunity. Proteolytic processing of its C terminus is essential for receptor binding and physiological activity. Therefore, we investigated the plasma stability of the decapeptide chemerin 145-154 (P(145)-F(154)) corresponding to the C terminus of the physiologically active chemerin variant E(21)-F(154) from human hemofiltrate. For monitoring concentration-time profiles and degradation products we developed a novel matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry procedure using an internal peptide standard (hemorphin LVV-H7) for quantification. The linear range covers 2.5 orders of magnitude in the lower micromolar concentration range (lower limit of quantification 0.312 microg/ml, 0.25 microM) characterized by satisfactory reproducibility (CV < or =9%), accuracy (< or =10%), ruggedness, and recovery (98%). We found that chemerin 145-154 is C-terminally truncated in human citrate plasma by the cleavage of the penultimate dipeptidyl residue. N-terminal truncation was not observed. In contrast to citrate plasma, no degradation was detected in ethylenediammetetraacetate (EDTA) plasma. We identified angiotensin-converting-enzyme (ACE) to be responsible for C-terminal truncation, which could be completely inhibited by EDTA and captopril. These results are relevant to clarify the natural processing of chemerin and the potential involvement of ACE in mediating the immune response.

The importance of retaining a phylogenetic perspective in traits-based community analyses

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

Poteat, Monica D.; Buchwalter, David B.; Jacobus, Luke M.

1) Many environmental stressors manifest their effects via physiological processes (traits) that can differ significantly among species and species groups. We compiled available data for three traits related to the bioconcentration of the toxic metal cadmium (Cd) from 42 aquatic insect species representing orders Ephemeroptera (mayfly), Plecoptera (stonefly), and Trichoptera (caddisfly). These traits included the propensity to take up Cd from water (uptake rate constant, ku), the ability to excrete Cd (efflux rate constant, ke), and the net result of these two processes (bioconcentration factor, BCF). 2) Ranges in these Cd bioaccumulation traits varied in magnitude across lineages (some lineagesmore » had a greater tendency to bioaccumulate Cd than others). Overlap in the ranges of trait values among different lineages was common and highlights situations where species from different lineages can share a similar trait state, but represent the high end of possible physiological values for one lineage and the low end for another. 3) Variance around the mean trait state differed widely across clades, suggesting that some groups (e.g., Ephemerellidae) are inherently more variable than others (e.g., Perlidae). Thus, trait variability/lability is at least partially a function of lineage. 4) Akaike information criterion (AIC) comparisons of statistical models were more often driven by clade than by other potential biological or ecological explanation tested. Clade-driven models generally improved with increasing taxonomic resolution. 5) Altogether, these findings suggest that lineage provides context for the analysis of species traits, and that failure to consider lineage in community-based analysis of traits may obscure important patterns of species responses to environmental change.« less

The importance of retaining a phylogenetic perspective in traits-based community analyses

DOE PAGES

Poteat, Monica D.; Buchwalter, David B.; Jacobus, Luke M.

2015-04-08

1) Many environmental stressors manifest their effects via physiological processes (traits) that can differ significantly among species and species groups. We compiled available data for three traits related to the bioconcentration of the toxic metal cadmium (Cd) from 42 aquatic insect species representing orders Ephemeroptera (mayfly), Plecoptera (stonefly), and Trichoptera (caddisfly). These traits included the propensity to take up Cd from water (uptake rate constant, ku), the ability to excrete Cd (efflux rate constant, ke), and the net result of these two processes (bioconcentration factor, BCF). 2) Ranges in these Cd bioaccumulation traits varied in magnitude across lineages (some lineagesmore » had a greater tendency to bioaccumulate Cd than others). Overlap in the ranges of trait values among different lineages was common and highlights situations where species from different lineages can share a similar trait state, but represent the high end of possible physiological values for one lineage and the low end for another. 3) Variance around the mean trait state differed widely across clades, suggesting that some groups (e.g., Ephemerellidae) are inherently more variable than others (e.g., Perlidae). Thus, trait variability/lability is at least partially a function of lineage. 4) Akaike information criterion (AIC) comparisons of statistical models were more often driven by clade than by other potential biological or ecological explanation tested. Clade-driven models generally improved with increasing taxonomic resolution. 5) Altogether, these findings suggest that lineage provides context for the analysis of species traits, and that failure to consider lineage in community-based analysis of traits may obscure important patterns of species responses to environmental change.« less

pH sensitive quantum dot-anthraquinone nanoconjugates

NASA Astrophysics Data System (ADS)

Ruedas-Rama, Maria Jose; Hall, Elizabeth A. H.

2014-05-01

Semiconductor quantum dots (QDs) have been shown to be highly sensitive to electron or charge transfer processes, which may alter their optical properties. This feature can be exploited for different sensing applications. Here, we demonstrate that QD-anthraquinone conjugates can function as electron transfer-based pH nanosensors. The attachment of the anthraquinones on the surface of QDs results in the reduction of electron hole recombination, and therefore a quenching of the photoluminescence intensity. For some anthraquinone derivatives tested, the quenching mechanism is simply caused by an electron transfer process from QDs to the anthraquinone, functioning as an electron acceptor. For others, electron transfer and energy transfer (FRET) processes were found. A detailed analysis of the quenching processes for CdSe/ZnS QD of two different sizes is presented. The photoluminescence quenching phenomenon of QDs is consistent with the pH sensitive anthraquinone redox chemistry. The resultant family of pH nanosensors shows pKa ranging ˜5-8, being ideal for applications of pH determination in physiological samples like blood or serum, for intracellular pH determination, and for more acidic cellular compartments such as endosomes and lysosomes. The nanosensors showed high selectivity towards many metal cations, including the most physiologically important cations which exist at high concentration in living cells. The reversibility of the proposed systems was also demonstrated. The nanosensors were applied in the determination of pH in samples mimicking the intracellular environment. Finally, the possibility of incorporating a reference QD to achieve quantitative ratiometric measurements was investigated.

Photoacoustic spectroscopy of CO2 laser in the detection of gaseous molecules

NASA Astrophysics Data System (ADS)

Lima, G. R.; Sthel, M. S.; da Silva, M. G.; Schramm, D. U. S.; de Castro, M. P. P.; Vargas, H.

2011-01-01

The detection of trace gases is very important for a variety of applications, including the monitoring of atmospheric pollutants, industrial process control, measuring air quality in workplaces, research into fruits physiological processes and medical diagnosis of diseases through the analysis of exhaled gases. The implementation of these and many other applications requiring gas sensors able to meet high sensitivity and selectivity. In this work, a photoacoustic laser spectrometer with CO2 emission in the infrared range and a resonant photoacoustic cell was used. We obtain the resonance frequency of 2.4 kHz to photoacoustic cell, was estimated detection limit of the spectrometer for molecules of ethylene (C2H4), 16 ppbV and ammonia (NH3) 42 ppbV.

Sensitivity analysis of physiological factors in space habitat design

NASA Technical Reports Server (NTRS)

Billingham, J.

1982-01-01

The costs incurred by design conservatism in space habitat design are discussed from a structural standpoint, and areas of physiological research into less than earth-normal conditions that offer the greatest potential decrease in habitat construction and operating costs are studied. The established range of human tolerance limits is defined for those physiological conditions which directly affect habitat structural design. These entire ranges or portions thereof are set as habitat design constraints as a function of habitat population and degree of ecological closure. Calculations are performed to determine the structural weight and cost associated with each discrete population size and its selected environmental conditions, on the basis of habitable volume equivalence for four basic habitat configurations: sphere, cylinder with hemispherical ends, torus, and crystal palace.

Androgen Metabolism in Progression to Androgen-Independent Prostate Cancer

DTIC Science & Technology

2011-06-01

confirming that AKR1C3 was mediating the synthesis of physiologically significant levels of testosterone from androstenedione. Although not selective, the... physiologically significant levels of androgen synthesis and AR reactivation (Figure 6D). While our data indicate that CYP17A1 mRNA is not...the micromolar range [14]. The low affinity of these antagonists compared to physiological ligands, in conjunction with adaptations that appear

Interspecies physiological variation as a tool for cross-species assessments of global warming-induced endangerment: validation of an intrinsic determinant of macroecological and phylogeographic structure.

PubMed

Bernardo, Joseph; Ossola, Ryan J; Spotila, James; Crandall, Keith A

2007-12-22

Global warming is now recognized as the dominant threat to biodiversity because even protected populations and habitats are susceptible. Nonetheless, current criteria for evaluating species' relative endangerment remain purely ecological, and the accepted conservation strategies of habitat preservation and population management assume that species can mount ecological responses if afforded protection. The insidious threat from climate change is that it will attenuate or preclude ecological responses by species that are physiologically constrained; yet, quantitative, objective criteria for assessing relative susceptibility of diverse taxa to warming-induced stress are wanting. We explored the utility of using interspecies physiological variation for this purpose by relating species' physiological phenotypes to landscape patterns of ecological and genetic exchange. Using a salamander model system in which ecological, genetic and physiological diversity are well characterized, we found strong quantitative relationships of basal metabolic rates (BMRs) to both macroecological and phylogeographic patterns, with decreasing BMR leading to dispersal limitation (small contemporary ranges with marked phylogeographic structure). Measures of intrinsic physiological tolerance, which vary systematically with macroecological and phylogeographic patterns, afford objective criteria for assessing endangerment across a wide range of species and should be incorporated into conservation assessment criteria that currently rely exclusively upon ecological predictors.

Present and future of membrane protein structure determination by electron crystallography.

PubMed

Ubarretxena-Belandia, Iban; Stokes, David L

2010-01-01

Membrane proteins are critical to cell physiology, playing roles in signaling, trafficking, transport, adhesion, and recognition. Despite their relative abundance in the proteome and their prevalence as targets of therapeutic drugs, structural information about membrane proteins is in short supply. This chapter describes the use of electron crystallography as a tool for determining membrane protein structures. Electron crystallography offers distinct advantages relative to the alternatives of X-ray crystallography and NMR spectroscopy. Namely, membrane proteins are placed in their native membranous environment, which is likely to favor a native conformation and allow changes in conformation in response to physiological ligands. Nevertheless, there are significant logistical challenges in finding appropriate conditions for inducing membrane proteins to form two-dimensional arrays within the membrane and in using electron cryo-microscopy to collect the data required for structure determination. A number of developments are described for high-throughput screening of crystallization trials and for automated imaging of crystals with the electron microscope. These tools are critical for exploring the necessary range of factors governing the crystallization process. There have also been recent software developments to facilitate the process of structure determination. However, further innovations in the algorithms used for processing images and electron diffraction are necessary to improve throughput and to make electron crystallography truly viable as a method for determining atomic structures of membrane proteins. Copyright © 2010 Elsevier Inc. All rights reserved.

Present and future of membrane protein structure determination by electron crystallography

PubMed Central

Ubarretxena-Belandia, Iban; Stokes, David L.

2011-01-01

Membrane proteins are critical to cell physiology, playing roles in signaling, trafficking, transport, adhesion, and recognition. Despite their relative abundance in the proteome and their prevalence as targets of therapeutic drugs, structural information about membrane proteins is in short supply. This review describes the use of electron crystallography as a tool for determining membrane protein structures. Electron crystallography offers distinct advantages relative to the alternatives of X-ray crystallography and NMR spectroscopy. Namely, membrane proteins are placed in their native membranous environment, which is likely to favor a native conformation and allow changes in conformation in response to physiological ligands. Nevertheless, there are significant logistical challenges in finding appropriate conditions for inducing membrane proteins to form two-dimensional arrays within the membrane and in using electron cryo-microscopy to collect the data required for structure determination. A number of developments are described for high-throughput screening of crystallization trials and for automated imaging of crystals with the electron microscope. These tools are critical for exploring the necessary range of factors governing the crystallization process. There have also been recent software developments to facilitate the process of structure determination. However, further innovations in the algorithms used for processing images and electron diffraction are necessary to improve throughput and to make electron crystallography truly viable as a method for determining atomic structures of membrane proteins. PMID:21115172

An instructional design process based on expert knowledge for teaching students how mechanisms are explained

PubMed Central

Anderson, Trevor R.; Pelaez, Nancy J.

2016-01-01

In biology and physiology courses, students face many difficulties when learning to explain mechanisms, a topic that is demanding due to the immense complexity and abstract nature of molecular and cellular mechanisms. To overcome these difficulties, we asked the following question: how does an instructor transform their understanding of biological mechanisms and other difficult-to-learn topics so that students can comprehend them? To address this question, we first reviewed a model of the components used by biologists to explain molecular and cellular mechanisms: the MACH model, with the components of methods (M), analogies (A), context (C), and how (H). Next, instructional materials were developed and the teaching activities were piloted with a physical MACH model. Students who used the MACH model to guide their explanations of mechanisms exhibited both improvements and some new difficulties. Third, a series of design-based research cycles was applied to bring the activities with an improved physical MACH model into biology and biochemistry courses. Finally, a useful rubric was developed to address prevalent student difficulties. Here, we present, for physiology and biology instructors, the knowledge and resources for explaining molecular and cellular mechanisms in undergraduate courses with an instructional design process aimed at realizing pedagogical content knowledge for teaching. Our four-stage process could be adapted to advance instruction with a range of models in the life sciences. PMID:27231262

How is physiology relevant to behavior analysis?

PubMed Central

Reese, Hayne W.

1996-01-01

Physiology is an important biological science; but behavior analysis is not a biological science, and behavior analysts can safely ignore biological processes. However, ignoring products of biological processes might be a serious mistake. The important products include behavior, instinctive drift, behavior potentials, hunger, and many developmental milestones and events. Physiology deals with the sources of such products; behavior analysis can deal with how the products affect behavior, which can be understood without understanding their sources. PMID:22478240

Ocean Acidification Portends Acute Habitat Compression for Atlantic Cod (Gadus morhua) in a Physiologically-informed Metabolic Rate Model

NASA Astrophysics Data System (ADS)

Del Raye, G.; Weng, K.

2011-12-01

Ocean acidification affects organisms on a biochemical scale, yet its societal impacts manifest from changes that propagate through entire populations. Successful forecasting of the effects of ocean acidification therefore depends on at least two steps: (1) deducing systemic physiology based on subcellular stresses and (2) scaling individual physiology up to ecosystem processes. Predictions that are based on known biological processes (process-based models) may fare better than purely statistical models in both these steps because the latter are less robust to novel environmental conditions. Here we present a process-based model that uses temperature, pO2, and pCO2 to predict maximal aerobic scope in Atlantic cod. Using this model, we show that (i) experimentally-derived physiological parameters are sufficient to capture the response of cod aerobic scope to temperature and oxygen, and (ii) subcellular pH effects can be used to predict the systemic physiological response of cod to an acidified ocean. We predict that acute pH stress (on a scale of hours) could limit the mobility of Atlantic cod during diel vertical migration across a pCO2 gradient, promoting habitat compression. Finally, we use a global sensitivity analysis to identify opportunities for the improvement of model uncertainty as well as some physiological adaptations that could mitigate climate stresses on cod in the future.

Diffuse correlation spectroscopy (DCS) study of blood flow changes during low level laser therapy (LLLT): a preliminary report

NASA Astrophysics Data System (ADS)

Soni, Sagar; Wang, Xinlong; Liu, Hanli; Tian, Fenghua

2017-02-01

Photobiomodulation with low-power, high-fluence light in the near-infrared range (600-1100nm), also known as low level laser therapy (LLLT), has been used for promoting healing of wounds, reducing pain, and so on. Understanding its physiological effect is essential for treatment optimization and evaluation. In this study, we used diffuse correlation spectroscopy (DCS) to investigate the changes of regional blood flow in skeletal muscle induced by a single session of LLLT. DCS is an emerging optical modality to probe microvascular blood flow in human tissues in vivo. We have developed a software-based autocorrelator system with the benefits such as flexibility in raw photon count data processing, portability and low cost. LLLT was administered at the human forearm with a 1064-nm, continuous-wave laser. The emitting power was 3.4 W in an area of 13.6 cm2, corresponding to 0.25W/cm2 irradiance. The emitting duration was 10 minutes. Eight healthy adults of any ethnic background, in an age range of 18-40 years old were included. The results indicate that LLLT causes reliable changes in regional blood flow. However, it remains unclear whether these changes are physiological or attributed to the heating effect of the stimulation laser.

Calibration of the physiological equivalent temperature index for three different climatic regions

NASA Astrophysics Data System (ADS)

Krüger, E.; Rossi, F.; Drach, P.

2017-07-01

In human biometeorology, the integration of several microclimatic variables as a combined index facilitates the understanding of how users perceive thermal environments. Indices, such as the physiological equivalent temperature (PET) index, translate the combined effects of meteorological variables on humans in terms of thermal stress or comfort and serve as important aids to climate-responsive urban and regional planning as well as heat stress and thermal comfort analyses. However, there is a need for adjusting proposed comfort/stress ranges of a given index when using it in different climatic contexts. The purpose of this study is to present a preliminary calibration procedure for the PET index for three different climatic regions: Curitiba, Brazil, a subtropical location; Rio de Janeiro, Brazil, a tropical city; and Glasgow, UK, a high-latitude location. Field studies have been carried out by the authors according to a similar protocol and using similar equipment, yielding actual thermal sensation votes and microclimate data, post-processed as PET data. The calibration procedure uses exclusively thermal sensation data as reported by pedestrians during outdoor comfort campaigns and concurrent microclimatic data recorded during the interviews. PET comfort/stress classes differ among the three locations and, in general, are less restrictive as in the original ranges proposed by the index developers.

Movement Complexity and Neuromechanical Factors Affect the Entropic Half-Life of Myoelectric Signals

PubMed Central

Hodson-Tole, Emma F.; Wakeling, James M.

2017-01-01

Appropriate neuromuscular functioning is essential for survival and features underpinning motor control are present in myoelectric signals recorded from skeletal muscles. One approach to quantify control processes related to function is to assess signal variability using measures such as Sample Entropy. Here we developed a theoretical framework to simulate the effect of variability in burst duration, activation duty cycle, and intensity on the Entropic Half-Life (EnHL) in myoelectric signals. EnHLs were predicted to be <40 ms, and to vary with fluctuations in myoelectric signal amplitude and activation duty cycle. Comparison with myoelectic data from rats walking and running at a range of speeds and inclines confirmed the range of EnHLs, however, the direction of EnHL change in response to altered locomotor demand was not correctly predicted. The discrepancy reflected different associations between the ratio of the standard deviation and mean signal intensity (Ist:It¯) and duty factor in simulated and physiological data, likely reflecting additional information in the signals from the physiological data (e.g., quiescent phase content; variation in action potential shapes). EnHL could have significant value as a novel marker of neuromuscular responses to alterations in perceived locomotor task complexity and intensity. PMID:28974932

Seed priming: state of the art and new perspectives.

PubMed

Paparella, S; Araújo, S S; Rossi, G; Wijayasinghe, M; Carbonera, D; Balestrazzi, Alma

2015-08-01

Priming applied to commercial seed lots is widely used by seed technologists to enhance seed vigour in terms of germination potential and increased stress tolerance. Priming can be also valuable to seed bank operators who need improved protocols of ex situ conservation of germplasm collections (crop and native species). Depending on plant species, seed morphology and physiology, different priming treatments can be applied, all of them triggering the so-called 'pre-germinative metabolism'. This physiological process takes place during early seed imbibition and includes the seed repair response (activation of DNA repair pathways and antioxidant mechanisms), essential to preserve genome integrity, ensuring proper germination and seedling development. The review provides an overview of priming technology, describing the range of physical-chemical and biological treatments currently available. Optimised priming protocols can be designed using the 'hydrotime concept' analysis which provides the theoretical bases for assessing the relationship between water potential and germination rate. Despite the efforts so far reported to further improve seed priming, novel ideas and cutting-edge investigations need to be brought into this technological sector of agri-seed industry. Multidisciplinary translational research combining digital, bioinformatic and molecular tools will significantly contribute to expand the range of priming applications to other relevant commercial sectors, e.g. the native seed market.

Attention modifies sound level detection in young children.

PubMed

Sussman, Elyse S; Steinschneider, Mitchell

2011-07-01

Have you ever shouted your child's name from the kitchen while they were watching television in the living room to no avail, so you shout their name again, only louder? Yet, still no response. The current study provides evidence that young children process loudness changes differently than pitch changes when they are engaged in another task such as watching a video. Intensity level changes were physiologically detected only when they were behaviorally relevant, but frequency level changes were physiologically detected without task relevance in younger children. This suggests that changes in pitch rather than changes in volume may be more effective in evoking a response when sounds are unexpected. Further, even though behavioral ability may appear to be similar in younger and older children, attention-based physiologic responses differ from automatic physiologic processes in children. Results indicate that 1) the automatic auditory processes leading to more efficient higher-level skills continue to become refined through childhood; and 2) there are different time courses for the maturation of physiological processes encoding the distinct acoustic attributes of sound pitch and sound intensity. The relevance of these findings to sound perception in real-world environments is discussed.

Gut feedback mechanisms and food intake: a physiological approach to slow carbohydrate bioavailability.

PubMed

Zhang, Genyi; Hasek, Like Y; Lee, Byung-Hoo; Hamaker, Bruce R

2015-04-01

Glycemic carbohydrates in foods are an important macronutrient providing the biological fuel of glucose for a variety of physiological processes. A classification of glycemic carbohydrates into rapidly digestible carbohydrate (RDC) and slowly digestible carbohydrate (SDC) has been used to specify their nutritional quality related to glucose homeostasis that is essential to normal functioning of the brain and critical to life. Although there have been many studies and reviews on slowly digestible starch (SDS) and SDC, the mechanisms of their slow digestion and absorption were mostly investigated from the material side without considering the physiological processes of their in vivo digestion, absorption, and most importantly interactions with other food components and the gastrointestinal tract. In this article, the physiological processes modulating the bioavailability of carbohydrates, specifically the rate and extent of their digestion and absorption as well as the related locations, in a whole food context, will be discussed by focusing on the activities of the gastrointestinal tract including glycolytic enzymes and glucose release, sugar sensing, gut hormones, and neurohormonal negative feedback mechanisms. It is hoped that a deep understanding of these physiological processes will facilitate the development of innovative dietary approaches to achieve desired carbohydrate or glucose bioavailability for improved health.

[Natural factors influencing sleep].

PubMed

Jurkowski, Marek K; Bobek-Billewicz, Barbara

2007-01-01

Sleep is a universal phenomenon of human and animal lives, although the importance of sleep for homeo-stasis is still unknown. Sleep disturbances influence many behavioral and physiologic processes, leading to health complications including death. On the other hand, sleep improvement can beneficially influence the course of healing of many disorders and can be a prognostic of health recovery. The factors influencing sleep have different biological and chemical origins. They are classical hormones, hypothalamic releasing and inhibitory hormones, neuropeptides, peptides and others as cytokines, prostaglandins, oleamid, adenosine, nitric oxide. These factors regulate most physiologic processes and are likely elements integrating sleep with physiology and physiology with sleep in health and disorders.

[Construction and analysis of a monitoring system with remote real-time multiple physiological parameters based on cloud computing].

PubMed

Zhu, Lingyun; Li, Lianjie; Meng, Chunyan

2014-12-01

There have been problems in the existing multiple physiological parameter real-time monitoring system, such as insufficient server capacity for physiological data storage and analysis so that data consistency can not be guaranteed, poor performance in real-time, and other issues caused by the growing scale of data. We therefore pro posed a new solution which was with multiple physiological parameters and could calculate clustered background data storage and processing based on cloud computing. Through our studies, a batch processing for longitudinal analysis of patients' historical data was introduced. The process included the resource virtualization of IaaS layer for cloud platform, the construction of real-time computing platform of PaaS layer, the reception and analysis of data stream of SaaS layer, and the bottleneck problem of multi-parameter data transmission, etc. The results were to achieve in real-time physiological information transmission, storage and analysis of a large amount of data. The simulation test results showed that the remote multiple physiological parameter monitoring system based on cloud platform had obvious advantages in processing time and load balancing over the traditional server model. This architecture solved the problems including long turnaround time, poor performance of real-time analysis, lack of extensibility and other issues, which exist in the traditional remote medical services. Technical support was provided in order to facilitate a "wearable wireless sensor plus mobile wireless transmission plus cloud computing service" mode moving towards home health monitoring for multiple physiological parameter wireless monitoring.

Impacts of climate change on marine top predators: Advances and future challenges

NASA Astrophysics Data System (ADS)

Hobday, Alistair J.; Arrizabalaga, Haritz; Evans, Karen; Nicol, Simon; Young, Jock W.; Weng, Kevin C.

2015-03-01

Oceanic top predators are the subject of studies by researchers under the international Climate Impacts on Oceanic Top Predators (CLIOTOP) program. A wide range of data sets have shown that environmental conditions, such as temperature and marine productivity, affect the distribution and biological processes of these species, and thus the activities of the humans that depend on them. In this special issue, 25 papers arising from the 2nd CLIOTOP symposium, held in Noumea, New Caledonia in February 2013 report the importance of realistic physical descriptions of oceanic processes for climate change projections, demonstrate a wide range of predator responses to historical climate variability, describe new analytical approaches for understanding the physiology, behaviour and trophodynamics, and project future distributions for a range of species. Several contributions discuss the implications for conservation and fisheries and show that resolving ecosystem management challenges and conflicts in the face of climate change is possible, but will require attention by decision-makers to issues that are broader than their traditional mandate. In the coming years, an increased focus on the development of management options to reduce the impacts of climate change on top predators and their dependent industries is needed.

Nearshore Satellite Data as Relative Indicators of Intertidal Organism Physiological Stress

NASA Astrophysics Data System (ADS)

Matzelle, A.; Helmuth, B.; Lakshmi, V.

2011-12-01

The physiological performance of intertidal and shallow subtidal invertebrates and algae is significantly affected by water temperature, and so the ability to measure and model onshore water temperatures is critical for ecological and biogeographic studies. Because of the localized influences of processes such as upwelling, mixing, and surface heating from solar radiation, nearshore water temperatures can differ from those measured directly offshore by buoys and satellites. It remains an open question what the magnitude of the differences in these temperatures are, and whether "large pixel" measurements can serve as an effective proxy for onshore processes, particularly when extrapolating from laboratory physiological studies to field conditions. We compared 9 years of nearshore (~10km) MODIS (Terra and Aqua overpasses) SST data against in situ measurements of water temperature conducted at two intertidal sites in central Oregon- Boiler Bay and Strawberry Hill. We collapsed data into increasingly longer temporal averages to address the correlation and absolute differences between onshore and nearshore temperatures over daily, weekly and monthly timescales. Results indicate that nearshore SST is a reasonable proxy for onshore water temperature, and that the strength of the correlation increases with decreasing temporal resolution. Correlations between differences in maxima are highest, followed by average and minima, and were lower at a site with regular upwelling. While average differences ranged from ~0.199-1.353°C, absolute differences across time scales were ~0.446-6.906°C, and were highest for cold temperatures. The results suggest that, at least at these two sites, SST can be used as a relative proxy for general trends only, especially over longer time scales.

High frequency oscillations are associated with cognitive processing in human recognition memory.

PubMed

Kucewicz, Michal T; Cimbalnik, Jan; Matsumoto, Joseph Y; Brinkmann, Benjamin H; Bower, Mark R; Vasoli, Vincent; Sulc, Vlastimil; Meyer, Fred; Marsh, W R; Stead, S M; Worrell, Gregory A

2014-08-01

High frequency oscillations are associated with normal brain function, but also increasingly recognized as potential biomarkers of the epileptogenic brain. Their role in human cognition has been predominantly studied in classical gamma frequencies (30-100 Hz), which reflect neuronal network coordination involved in attention, learning and memory. Invasive brain recordings in animals and humans demonstrate that physiological oscillations extend beyond the gamma frequency range, but their function in human cognitive processing has not been fully elucidated. Here we investigate high frequency oscillations spanning the high gamma (50-125 Hz), ripple (125-250 Hz) and fast ripple (250-500 Hz) frequency bands using intracranial recordings from 12 patients (five males and seven females, age 21-63 years) during memory encoding and recall of a series of affectively charged images. Presentation of the images induced high frequency oscillations in all three studied bands within the primary visual, limbic and higher order cortical regions in a sequence consistent with the visual processing stream. These induced oscillations were detected on individual electrodes localized in the amygdala, hippocampus and specific neocortical areas, revealing discrete oscillations of characteristic frequency, duration and latency from image presentation. Memory encoding and recall significantly modulated the number of induced high gamma, ripple and fast ripple detections in the studied structures, which was greater in the primary sensory areas during the encoding (Wilcoxon rank sum test, P = 0.002) and in the higher-order cortical association areas during the recall (Wilcoxon rank sum test, P = 0.001) of memorized images. Furthermore, the induced high gamma, ripple and fast ripple responses discriminated the encoded and the affectively charged images. In summary, our results show that high frequency oscillations, spanning a wide range of frequencies, are associated with memory processing and generated along distributed cortical and limbic brain regions. These findings support an important role for fast network synchronization in human cognition and extend our understanding of normal physiological brain activity during memory processing. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Physiology and quality of fresh-cut produce in CA/MA storage

USDA-ARS?s Scientific Manuscript database

Fresh-cut fruits and vegetables have exposed injured tissues due to the mechanical processes of peeling, slicing and/or cutting. Such processing consequently renders the produce highly susceptible to physiological breakdown and microbial spoilage. Product deterioration is usually accompanied with ph...

21 CFR 315.5 - Evaluation of effectiveness.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 601.34 - Evaluation of effectiveness.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 315.5 - Evaluation of effectiveness.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 315.5 - Evaluation of effectiveness.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 601.34 - Evaluation of effectiveness.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 601.34 - Evaluation of effectiveness.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 315.5 - Evaluation of effectiveness.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 601.34 - Evaluation of effectiveness.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 601.34 - Evaluation of effectiveness.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

21 CFR 315.5 - Evaluation of effectiveness.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., physiological, or biochemical assessment is established by demonstrating in a defined clinical setting reliable measurement of function(s) or physiological, biochemical, or molecular process(es). (3) The claim of disease... demonstrating in a defined clinical setting that the test is useful in diagnostic or therapeutic patient...

Physiological mechanisms underlying animal social behaviour.

PubMed

Seebacher, Frank; Krause, Jens

2017-08-19

Many species of animal live in groups, and the group represents the organizational level within which ecological and evolutionary processes occur. Understanding these processes, therefore, relies on knowledge of the mechanisms that permit or constrain group formation. We suggest that physiological capacities and differences in physiology between individuals modify fission-fusion dynamics. Differences between individuals in locomotor capacity and metabolism may lead to fission of groups and sorting of individuals into groups with similar physiological phenotypes. Environmental impacts such as hypoxia can influence maximum group sizes and structure in fish schools by altering access to oxygenated water. The nutritional environment determines group cohesion, and the increase in information collected by the group means that individuals should rely more on social information and form more cohesive groups in uncertain environments. Changing environmental contexts require rapid responses by individuals to maintain group coordination, which are mediated by neuroendocrine signalling systems such as nonapeptides and steroid hormones. Brain processing capacity may constrain social complexity by limiting information processing. Failure to evaluate socially relevant information correctly limits social interactions, which is seen, for example, in autism. Hence, functioning of a group relies to a large extent on the perception and appropriate processing of signals from conspecifics. Many if not all physiological systems are mechanistically linked, and therefore have synergistic effects on social behaviour. A challenge for the future lies in understanding these interactive effects, which will improve understanding of group dynamics, particularly in changing environments.This article is part of the themed issue 'Physiological determinants of social behaviour in animals'. © 2017 The Author(s).

Physiological mechanisms underlying animal social behaviour

PubMed Central

2017-01-01

Many species of animal live in groups, and the group represents the organizational level within which ecological and evolutionary processes occur. Understanding these processes, therefore, relies on knowledge of the mechanisms that permit or constrain group formation. We suggest that physiological capacities and differences in physiology between individuals modify fission–fusion dynamics. Differences between individuals in locomotor capacity and metabolism may lead to fission of groups and sorting of individuals into groups with similar physiological phenotypes. Environmental impacts such as hypoxia can influence maximum group sizes and structure in fish schools by altering access to oxygenated water. The nutritional environment determines group cohesion, and the increase in information collected by the group means that individuals should rely more on social information and form more cohesive groups in uncertain environments. Changing environmental contexts require rapid responses by individuals to maintain group coordination, which are mediated by neuroendocrine signalling systems such as nonapeptides and steroid hormones. Brain processing capacity may constrain social complexity by limiting information processing. Failure to evaluate socially relevant information correctly limits social interactions, which is seen, for example, in autism. Hence, functioning of a group relies to a large extent on the perception and appropriate processing of signals from conspecifics. Many if not all physiological systems are mechanistically linked, and therefore have synergistic effects on social behaviour. A challenge for the future lies in understanding these interactive effects, which will improve understanding of group dynamics, particularly in changing environments. This article is part of the themed issue ‘Physiological determinants of social behaviour in animals’. PMID:28673909

Electrocardiographic consequences of a peripatetic lifestyle in gray wolves (Canis lupus)

USGS Publications Warehouse

Constable, Peter; Hinchcliff, Ken; Demma, Nick; Callahan, Margaret; Dale, Bruce W.; Fox, Kevin; Adams, Layne G.; Wack, Ray; Kramer, Lynn

1998-01-01

Cardiac chamber enlargement and hypertrophy are normal physiologic responses to repetitive endurance exercise activity in human beings and domestic dogs. Whether similar changes occur in wild animals as a consequence of increased activity is unknown. We found that free-ranging gray wolves (Canis lupus, n=11), the archetypical endurance athlete, have electrocardiographic evidence of cardiac chamber enlargement and hypertrophy relative to sedentary captive gray wolves (n=20), as demonstrated by significant increases in QRS duration, QT interval, and QT interval corrected for heart rate, a tendency towards increased Q, R, and S wave voltages in all leads, and a significant decrease in heart rate. We conclude that exercise activity level and therefore lifestyle affects physiologic variables in wild animals. An immediate consequence of this finding is that physiologic measurements obtained from a captive wild-animal population with reduced exercise activity level may not accurately reflect the normal physiologic state for free-ranging members of the same species.

Effects of Recurrent Stress and a Music Intervention on Tumor Progression and Indices of Distress in an MNU-induced Mammary Cancer in Rats

DTIC Science & Technology

2011-03-04

through negative emotions, behavioral disruptions, and/or physiological reactions (Grunberg & Singer, 1990; Baum, Gatchel, & Krantz, 1997; Park...biological responses that range from activation of the HPA axis to 14 altering the physiology of internal organs and organ systems (Kvetnansky, Weise...Females consistently show greater physiological response to both acute and chronic stressors, which many investigators attribute to sex hormone

Optical coherence tomography for the quantitative study of cerebrovascular physiology

PubMed Central

Srinivasan, Vivek J; Atochin, Dmitriy N; Radhakrishnan, Harsha; Jiang, James Y; Ruvinskaya, Svetlana; Wu, Weicheng; Barry, Scott; Cable, Alex E; Ayata, Cenk; Huang, Paul L; Boas, David A

2011-01-01

Doppler optical coherence tomography (DOCT) and OCT angiography are novel methods to investigate cerebrovascular physiology. In the rodent cortex, DOCT flow displays features characteristic of cerebral blood flow, including conservation along nonbranching vascular segments and at branch points. Moreover, DOCT flow values correlate with hydrogen clearance flow values when both are measured simultaneously. These data validate DOCT as a noninvasive quantitative method to measure tissue perfusion over a physiologic range. PMID:21364599

Physiological Monitoring of Optically Trapped Cells: Studying the Effects of Confinement by 1064 NM Lazer Tweezers Using Microfluorometry

NASA Astrophysics Data System (ADS)

Liu, Yagang

A novel technique that combines microfluorometric detection and optical laser trapping has been developed for in-situ assessing the physiological state of an optically trapped biological sample. This optical diagnostic technique achieves high sensitivity (>30 dB signal -to-noise ratio) and high spatial resolution (~ 1 μm) over a broad spectral range (>400 nm). The fluorescence spectra derived from exogenous fluorescent probes, including laurdan, acridine orange, propidium iodide and Snarf, are used to assess the effects of optical confinement with respect to temperature, DNA structure, cell viability, and intracellular pH, respectively. In the latter three cases, fluorescence is excited via a two-photon absorption process, using the cw laser trap itself as the fluorescence excitation source. This enables the cw near infrared laser trapping beam to be used simultaneously as an optical diagnostic probe as well as an optical micromanipulator. Using microfluorometry, a temperature increase of less than several degrees centigrade was measured for test samples, including liposomes, Chinese hamster ovary (CHO) cells and human sperm cells that were held stationary by 1064 nm optical tweezers having a power density of ~10^7 W/cm^2. Additional physiological monitoring experiments indicated that there is no observable denaturation of DNA, or change of intracellular pH under typical continuous wave laser trapping conditions (P <= 400 mW). Under some circumstances, however, it was possible to achieve a decrease in cell viability with cw trapping, as monitored by a live/dead vital stain. In comparison, significant DNA denaturation and cellular physiological changes (e.g. cell death) were observed when a Q-switched pulsed laser at a threshold of ~30mu J/pulse was used as trapping source. These results generally support the conclusion that cw laser trapping at 1064 nm wavelength is a safe, non-invasive process and should prove to be of great value for understanding the mechanisms of laser microirradiation effects on living cells held stationary in a near-infrared trapping beam.

Virtual physiological human: training challenges.

PubMed

Lawford, Patricia V; Narracott, Andrew V; McCormack, Keith; Bisbal, Jesus; Martin, Carlos; Bijnens, Bart; Brook, Bindi; Zachariou, Margarita; Freixa, Jordi Villà I; Kohl, Peter; Fletcher, Katherine; Diaz-Zuccarini, Vanessa

2010-06-28

The virtual physiological human (VPH) initiative encompasses a wide range of activities, including structural and functional imaging, data mining, knowledge discovery tool and database development, biomedical modelling, simulation and visualization. The VPH community is developing from a multitude of relatively focused, but disparate, research endeavours into an integrated effort to bring together, develop and translate emerging technologies for application, from academia to industry and medicine. This process initially builds on the evolution of multi-disciplinary interactions and abilities, but addressing the challenges associated with the implementation of the VPH will require, in the very near future, a translation of quantitative changes into a new quality of highly trained multi-disciplinary personnel. Current strategies for undergraduate and on-the-job training may soon prove insufficient for this. The European Commission seventh framework VPH network of excellence is exploring this emerging need, and is developing a framework of novel training initiatives to address the predicted shortfall in suitably skilled VPH-aware professionals. This paper reports first steps in the implementation of a coherent VPH training portfolio.

Optical properties of in-vitro biomineralised silica

PubMed Central

Polini, Alessandro; Pagliara, Stefano; Camposeo, Andrea; Cingolani, Roberto; Wang, Xiaohong; Schröder, Heinz C.; Müller, Werner E. G.; Pisignano, Dario

2012-01-01

Silicon is the second most common element on the Earth's crust and its oxide (SiO2) the most abundant mineral. Silica and silicates are widely used in medicine and industry as well as in micro- and nano-optics and electronics. However, the fabrication of glass fibres and components requires high temperature and non-physiological conditions, in contrast to biosilica structures in animals and plants. Here, we show for the first time the use of recombinant silicatein-α, the most abundant subunit of sponge proteins catalyzing biosilicification reactions, to direct the formation of optical waveguides in-vitro through soft microlithography. The artificial biosilica fibres mimic the natural sponge spicules, exhibiting refractive index values suitable for confinement of light within waveguides, with optical losses in the range of 5–10 cm−1, suitable for application in lab-on-chips systems. This method extends biosilicification to the controlled fabrication of optical components by physiological processing conditions, hardly addressed by conventional technologies. PMID:22934130

Stress corrosion cracking of an aluminum alloy used in external fixation devices.

PubMed

Cartner, Jacob L; Haggard, Warren O; Ong, Joo L; Bumgardner, Joel D

2008-08-01

Treatment for compound and/or comminuted fractures is frequently accomplished via external fixation. To achieve stability, the compositions of external fixators generally include aluminum alloy components due to their high strength-to-weight ratios. These alloys are particularly susceptible to corrosion in chloride environments. There have been several clinical cases of fixator failure in which corrosion was cited as a potential mechanism. The aim of this study was to evaluate the effects of physiological environments on the corrosion susceptibility of aluminum 7075-T6, since it is used in orthopedic external fixation devices. Electrochemical corrosion curves and alternate immersion stress corrosion cracking tests indicated aluminum 7075-T6 is susceptible to corrosive attack when placed in physiological environments. Pit initiated stress corrosion cracking was the primary form of alloy corrosion, and subsequent fracture, in this study. Anodization of the alloy provided a protective layer, but also caused a decrease in passivity ranges. These data suggest that once the anodization layer is disrupted, accelerated corrosion processes occur. (c) 2007 Wiley Periodicals, Inc.

Neurons for hunger and thirst transmit a negative-valence teaching signal

PubMed Central

Gong, Rong; Magnus, Christopher J.; Yu, Yang; Sternson, Scott M.

2015-01-01

Homeostasis is a biological principle for regulation of essential physiological parameters within a set range. Behavioural responses due to deviation from homeostasis are critical for survival, but motivational processes engaged by physiological need states are incompletely understood. We examined motivational characteristics and dynamics of two separate neuron populations that regulate energy and fluid homeostasis by using cell type-specific activity manipulations in mice. We found that starvation-sensitive AGRP neurons exhibit properties consistent with a negative-valence teaching signal. Mice avoided activation of AGRP neurons, indicating that AGRP neuron activity has negative valence. AGRP neuron inhibition conditioned preference for flavours and places. Correspondingly, deep-brain calcium imaging revealed that AGRP neuron activity rapidly reduced in response to food-related cues. Complementary experiments activating thirst-promoting neurons also conditioned avoidance. Therefore, these need-sensing neurons condition preference for environmental cues associated with nutrient or water ingestion, which is learned through reduction of negative-valence signals during restoration of homeostasis. PMID:25915020

Translating Metabolomics to Cardiovascular Biomarkers

PubMed Central

Senn, Todd; Hazen, Stanley L.; Tang, W. H. Wilson

2012-01-01

Metabolomics is the systematic study of the unique chemical fingerprints of small-molecules, or metabolite profiles, that are related to a variety of cellular metabolic processes in a cell, organ, or organism. While mRNA gene expression data and proteomic analyses do not tell the whole story of what might be happening in a cell, metabolic profiling provides direct and indirect physiologic insights that can potentially be detectable in a wide range of biospecimens. Although not specific to cardiac conditions, translating metabolomics to cardiovascular biomarkers has followed the traditional path of biomarker discovery from identification and confirmation to clinical validation and bedside testing. With technological advances in metabolomic tools (such as nuclear magnetic resonance spectroscopy and mass spectrometry) and more sophisticated bioinformatics and analytical techniques, the ability to measure low-molecular-weight metabolites in biospecimens provides a unique insight into established and novel metabolic pathways. Systemic metabolomics may provide physiologic understanding of cardiovascular disease states beyond traditional profiling, and may involve descriptions of metabolic responses of an individual or population to therapeutic interventions or environmental exposures. PMID:22824112

The impact of physiological crowding on the diffusivity of membrane bound proteins.

PubMed

Houser, Justin R; Busch, David J; Bell, David R; Li, Brian; Ren, Pengyu; Stachowiak, Jeanne C

2016-02-21

Diffusion of transmembrane and peripheral membrane-bound proteins within the crowded cellular membrane environment is essential to diverse biological processes including cellular signaling, endocytosis, and motility. Nonetheless we presently lack a detailed understanding of the influence of physiological levels of crowding on membrane protein diffusion. Utilizing quantitative in vitro measurements, here we demonstrate that the diffusivities of membrane bound proteins follow a single linearly decreasing trend with increasing membrane coverage by proteins. This trend holds for homogenous protein populations across a range of protein sizes and for heterogeneous mixtures of proteins of different sizes, such that protein diffusivity is controlled by the total coverage of the surrounding membrane. These results demonstrate that steric exclusion within the crowded membrane environment can fundamentally limit the diffusive rate of proteins, regardless of their size. In cells this "speed limit" could be modulated by changes in local membrane coverage, providing a mechanism for tuning the rate of molecular interaction and assembly.

Species-specific control of external superoxide levels by the coral holobiont during a natural bleaching event

NASA Astrophysics Data System (ADS)

Diaz, Julia M.; Hansel, Colleen M.; Apprill, Amy; Brighi, Caterina; Zhang, Tong; Weber, Laura; McNally, Sean; Xun, Liping

2016-12-01

The reactive oxygen species superoxide (O2.-) is both beneficial and detrimental to life. Within corals, superoxide may contribute to pathogen resistance but also bleaching, the loss of essential algal symbionts. Yet, the role of superoxide in coral health and physiology is not completely understood owing to a lack of direct in situ observations. By conducting field measurements of superoxide produced by corals during a bleaching event, we show substantial species-specific variation in external superoxide levels, which reflect the balance of production and degradation processes. Extracellular superoxide concentrations are independent of light, algal symbiont abundance and bleaching status, but depend on coral species and bacterial community composition. Furthermore, coral-derived superoxide concentrations ranged from levels below bulk seawater up to ~120 nM, some of the highest superoxide concentrations observed in marine systems. Overall, these results unveil the ability of corals and/or their microbiomes to regulate superoxide in their immediate surroundings, which suggests species-specific roles of superoxide in coral health and physiology.

Calcitonin and calcitonin receptors: bone and beyond

PubMed Central

Pondel, Marc

2000-01-01

Calcitonin (CT), a 32 amino acid peptide hormone produced primarily by the thyroid, and its receptor (CTR) are well known for their ability to regulate osteoclast mediated bone resorption and enhance Ca2+ excretion by the kidney. However, recent studies now suggest that CT and CTRs may play an important role in a variety of processes as wide ranging as embryonic/foetal development and sperm function/physiology. In this review article, CT and CTR gene transcription, signal transduction and function are addressed. The effects of CT on the physiology of a variety of organ systems are discussed and the relationship between polymorphisms in the CTR gene and bone mineral density (BMD)/osteoporosis is examined. Recent studies demonstrating the ability of receptor activity modifying proteins (RAMPs) to post-translationally modify the calcitonin receptor-like receptor (CRLR) are detailed and studies employing transgenic mouse technology to determine the temporal and tissue specific transcriptional activity of the CTR gene in vivo are discussed. PMID:11298188

Analysis of cerebral vessels dynamics using experimental data with missed segments

NASA Astrophysics Data System (ADS)

Pavlova, O. N.; Abdurashitov, A. S.; Ulanova, M. V.; Shihalov, G. M.; Semyachkina-Glushkovskaya, O. V.; Pavlov, A. N.

2018-04-01

Physiological signals often contain various bad segments that occur due to artifacts, failures of the recording equipment or varying experimental conditions. The related experimental data need to be preprocessed to avoid such parts of recordings. In the case of few bad segments, they can simply be removed from the signal and its analysis is further performed. However, when there are many extracted segments, the internal structure of the analyzed physiological process may be destroyed, and it is unclear whether such signal can be used in diagnostic-related studies. In this paper we address this problem for the case of cerebral vessels dynamics. We perform analysis of simulated data in order to reveal general features of quantifying scaling features of complex signals with distinct correlation properties and show that the effects of data loss are significantly different for experimental data with long-range correlations and anti-correlations. We conclude that the cerebral vessels dynamics is significantly less sensitive to missed data fragments as compared with signals with anti-correlated statistics.

The Role of Inhibitory Control in Behavioral and Physiological Expressions of Toddler Executive Function

PubMed Central

Morasch, Katherine C.; Bell, Martha Ann

2010-01-01

Eighty-one toddlers (ranging from 24 to 27 months) participated in a biobehavioral investigation of inhibitory control. Maternal-report measures of inhibitory control were related to laboratory tasks assessing inhibitory abilities under conditions of conflict, delay, and compliance challenge as well as toddler verbal ability. Additionally, unique variance in inhibitory control was explained by task-related changes in brain electrical activity at lateral frontal scalp sites as well as concurrent inhibitory task performance. Implications regarding neural correlates of executive function in early development and a central, organizing role of inhibitory processing in toddlerhood are discussed. PMID:20719337

[Prescribing monitoring in clinical practice: from enlightened empiricism to rational strategies].

PubMed

Buclin, Thierry; Herzig, Lilli

2013-05-15

Monitoring of a medical condition is the periodic measurement of one or several physiological or biological variables to detect a signal regarding its clinical progression or its response to treatment. We distinguish different medical situations between diagnostic, clinical and therapeutic process to apply monitoring. Many clinical, variables can be used for monitoring, once their intrinsic properties (normal range, critical difference, kinetics, reactivity) and external validity (pathophysiological importance, predictive power for clinical outcomes) are established. A formal conceptualization of monitoring is being developed and should support the rational development of monitoring strategies and their validation through appropriate clinical trials.

The role of microRNAs in skeletal muscle health and disease

PubMed Central

Kirby, Tyler J.; Chaillou, Thomas; McCarthy, John J.

2016-01-01

Over the last decade non-coding RNAs have emerged as importance regulators of gene expression. In particular, microRNAs are a class of small RNAs of ~ 22 nucleotides that repress gene expression through a post-transcriptional mechanism. MicroRNAs have been shown to be involved in a broader range of biological processes, both physiological and pathological, including myogenesis, adaptation to exercise and various myopathies. The purpose of this review is to provide a comprehensive summary of what is currently known about the role of microRNAs in skeletal muscle health and disease. PMID:25553440

Long-distance transport of phytohormones through the plant vascular system.

PubMed

Lacombe, Benoit; Achard, Patrick

2016-12-01

Phytohormones are a group of low abundance molecules that activate various metabolic and developmental processes in response to environmental and endogenous signals. Like animal hormones, plant hormones often have distinct source and target tissues, hence ensuring long-range communication at the whole-plant level. Plants rely on various hormone distribution mechanisms depending on the distance and the direction of the transport. Here, we highlight the recent findings on the long-distance movement of plant hormones within the vasculature, from the physiological role to the molecular mechanism of the transport. Copyright © 2016 Elsevier Ltd. All rights reserved.

Piezo2 in Cutaneous and Proprioceptive Mechanotransduction in Vertebratesa

PubMed Central

Anderson, E.O.; Schneider, E.R.; Bagriantsev, S.N.

2017-01-01

Mechanosensitivity is a fundamental physiological capacity, which pertains to all life forms. Progress has been made with regard to understanding mechanosensitivity in bacteria, flies, and worms. In vertebrates, however, the molecular identity of mechanotransducers in somatic and neuronal cells has only started to appear. The Piezo family of mechanogated ion channels marks a pivotal milestone in understanding mechanosensitivity. Piezo1 and Piezo2 have now been shown to participate in a number of processes, ranging from arterial modeling to sensing muscle stretch. In this review, we focus on Piezo2 and its role in mediating mechanosensation and proprioception in vertebrates. PMID:28728817

Cross spectral, active and passive approach to face recognition for improved performance

NASA Astrophysics Data System (ADS)

Grudzien, A.; Kowalski, M.; Szustakowski, M.

2017-08-01

Biometrics is a technique for automatic recognition of a person based on physiological or behavior characteristics. Since the characteristics used are unique, biometrics can create a direct link between a person and identity, based on variety of characteristics. The human face is one of the most important biometric modalities for automatic authentication. The most popular method of face recognition which relies on processing of visual information seems to be imperfect. Thermal infrared imagery may be a promising alternative or complement to visible range imaging due to its several reasons. This paper presents an approach of combining both methods.

Water-soluble triazabutadienes that release diazonium species upon protonation under physiologically relevant conditions.

PubMed

Kimani, Flora W; Jewett, John C

2015-03-23

Triazabutadienes are an understudied structural motif that have remarkable reactivity once rendered water-soluble. It is shown that these molecules readily release diazonium species in a pH-dependent manner in a series of buffer solutions with pH ranges similar to those found in cells. Upon further development, we expect that this process will be well suited to cargo-release strategies and organelle-specific bioconjugation reactions. These compounds offer one of the mildest ways of generating diazonium species in aqueous solutions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Are more complex physiological models of forest ecosystems better choices for plot and regional predictions?

Treesearch

Wenchi Jin; Hong S. He; Frank R. Thompson

2016-01-01

Process-based forest ecosystem models vary from simple physiological, complex physiological, to hybrid empirical-physiological models. Previous studies indicate that complex models provide the best prediction at plot scale with a temporal extent of less than 10 years, however, it is largely untested as to whether complex models outperform the other two types of models...

Declining performance of master athletes: silhouettes of the trajectory of healthy human ageing?

PubMed

Lazarus, Norman R; Harridge, Stephen D R

2017-05-01

Analysis of world record performances by master athletes suggests an essentially linear decline with age until around the eighth decade after which performance decline accelerates. Because these records are obtained from highly trained individuals they can be viewed as being reflective of the diminution of integrative physiological prowess that occurs solely as a result of ageing, unaffected by the confounding effects of inactivity. It can also be argued that these performance profiles mirror and provide an insight into the trajectory of the physiology of the human ageing process. Here we propose a set point theory that hypothesises that a given threshold of physical activity is needed to age optimally and to maximise the 'healthspan'. Exercising at levels below the set point will result in ageing being contaminated by the unpredictable and pathological effects of inactivity. Exercise above this threshold stimulates adaptations towards maximising athletic performance, but is unlikely to have further beneficial effects on health. Thus the decades-long, controlled diminution in athletic performance, should not be seen as a disease process. The ageing process is separate from, and independent of, exercise-mediated processes that maintain or adapt physiological function. Whether an understanding of these mechanisms will also help uncover mechanisms underpinning the ageing process itself is open to question. However, any model which does not take into account the effects of activity will not adequately describe the inherent ageing process. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

Stimulatory effects of calcium on respiration and NAD(P)H synthesis in intact rat heart mitochondria utilizing physiological substrates cannot explain respiratory control in vivo.

PubMed

Vinnakota, Kalyan C; Dash, Ranjan K; Beard, Daniel A

2011-09-02

Mitochondrial TCA cycle dehydrogenase enzymes have been shown to be stimulated by Ca(2+) under various substrate and ADP incubation conditions in an attempt to determine and understand the role of Ca(2+) in maintaining energy homeostasis in working hearts. In this study, we tested the hypothesis that, at physiological temperature and 1 mM extramitochondrial free magnesium, Ca(2+) can stimulate the overall mitochondrial NAD(P)H generation flux in rat heart mitochondria utilizing pyruvate and malate as substrates at both subsaturating and saturating concentrations. In both cases, we found that, in the physiological regime of mitochondrial oxygen consumption observed in the intact animal and in the physiological range of cytosolic Ca(2+) concentration averaged per beat, Ca(2+) had no observable stimulatory effect. A modest apparent stimulatory effect (22-27%) was observable at supraphysiological maximal ADP-stimulated respiration at 2.5 mM initial phosphate. The stimulatory effects observed over the physiological Ca(2+) range are not sufficient to make a significant contribution to the control of oxidative phosphorylation in the heart in vivo.

Stimulatory Effects of Calcium on Respiration and NAD(P)H Synthesis in Intact Rat Heart Mitochondria Utilizing Physiological Substrates Cannot Explain Respiratory Control in Vivo*

PubMed Central

Vinnakota, Kalyan C.; Dash, Ranjan K.; Beard, Daniel A.

2011-01-01

Mitochondrial TCA cycle dehydrogenase enzymes have been shown to be stimulated by Ca2+ under various substrate and ADP incubation conditions in an attempt to determine and understand the role of Ca2+ in maintaining energy homeostasis in working hearts. In this study, we tested the hypothesis that, at physiological temperature and 1 mm extramitochondrial free magnesium, Ca2+ can stimulate the overall mitochondrial NAD(P)H generation flux in rat heart mitochondria utilizing pyruvate and malate as substrates at both subsaturating and saturating concentrations. In both cases, we found that, in the physiological regime of mitochondrial oxygen consumption observed in the intact animal and in the physiological range of cytosolic Ca2+ concentration averaged per beat, Ca2+ had no observable stimulatory effect. A modest apparent stimulatory effect (22–27%) was observable at supraphysiological maximal ADP-stimulated respiration at 2.5 mm initial phosphate. The stimulatory effects observed over the physiological Ca2+ range are not sufficient to make a significant contribution to the control of oxidative phosphorylation in the heart in vivo. PMID:21757763

pH and chloride recordings in living cells using two-photon fluorescence lifetime imaging microscopy

NASA Astrophysics Data System (ADS)

Lahn, Mattes; Hille, Carsten; Koberling, Felix; Kapusta, Peter; Dosche, Carsten

2010-02-01

Today fluorescence lifetime imaging microscopy (FLIM) has become an extremely powerful technique in life sciences. The independency of the fluorescence decay time on fluorescence dye concentration and emission intensity circumvents many artefacts arising from intensity based measurements. To minimize cell damage and improve scan depth, a combination with two-photon (2P) excitation is quite promising. Here, we describe the implementation of a 2P-FLIM setup for biological applications. For that we used a commercial fluorescence lifetime microscope system. 2P-excitation at 780nm was achieved by a non-tuneable, but inexpensive and easily manageable mode-locked fs-fiber laser. Time-resolved fluorescence image acquisition was performed by objective-scanning with the reversed time-correlated single photon counting (TCSPC) technique. We analyzed the suitability of the pH-sensitive dye BCECF and the chloride-sensitive dye MQAE for recordings in an insect tissue. Both parameters are quite important, since they affect a plethora of physiological processes in living tissues. We performed a straight forward in situ calibration method to link the fluorescence decay time with the respective ion concentration and carried out spatially resolved measurements under resting conditions. BCECF still offered only a limited dynamic range regarding fluorescence decay time changes under physiologically pH values. However, MQAE proofed to be well suited to record chloride concentrations in the physiologically relevant range. Subsequently, several chloride transport pathways underlying the intracellular chloride homeostasis were investigated pharmacologically. In conclusion, 2P-FLIM is well suited for ion detection in living tissues due to precise and reproducible decay time measurements in combination with reduced cell and dye damages.

ATM activation in normal human tissues and testicular cancer.

PubMed

Bartkova, Jirina; Bakkenist, Christopher J; Rajpert-De Meyts, Ewa; Skakkebaek, Niels E; Sehested, Maxwell; Lukas, Jiri; Kastan, Michael B; Bartek, Jiri

2005-06-01

The ATM kinase is a tumor suppressor and key regulator of biological responses to DNA damage. Cultured cells respond to genotoxic insults that induce DNA double-strand breaks by prompt activation of ATM through its autophosphorylation on serine 1981. However, whether ATM-S1981 becomes phosphorylated in vivo, for example during physiological processes that generate DSBs, is unknown. Here we produced phospho-specific monoclonal antibodies against S1981-phosphorylated ATM (pS-ATM), and applied them to immunohistochemical analyses of a wide range of normal human tissues and testicular tumors. Our data show that regardless of proliferation and differentiation, most human tissues contain only the S1981-nonphosphorylated, inactive form of ATM. In contrast, nuclear staining for pS-ATM was detected in subsets of bone-marrow lymphocytes and primary spermatocytes in the adult testes, cell types in which DSBs are generated during physiological V(D)J recombination and meiotic recombination, respectively. Among testicular germ-cell tumors, an aberrant constitutive pS-ATM was observed especially in embryonal carcinomas, less in seminomas, and only modestly in teratomas and the pre-invasive carcinoma-in-situ stage. Compared with pS-ATM, phosphorylated histone H2AX (gammaH2AX), another DNA damage marker and ATM substrate, was detected in a higher proportion of cancer cells, and also in normal fetal gonocytes, and a wider range of adult spermatocyte differentiation stages. Collectively, our results strongly support the physiological relevance of the recently proposed model of ATM autoactivation, and provide further evidence for constitutive activation of the DNA damage machinery during cancer development. The new tools characterized here should facilitate monitoring of ATM activation in clinical specimens, and help develop future treatment strategies.

[Variability patterns of nest construction, physiological state, and morphometric traits in honey bee].

PubMed

Es'kov, E K; Es'kova, M D

2014-01-01

High variability of cells size is used selectively for reproduction of working bees and drones. A decrease in both distance between cells and cells size themselves causes similar effects to body mass and morphometric traits of developing individuals. Adaptation of honey bees to living in shelters has led to their becoming tolerant to hypoxia. Improvement of ethological and physiological mechanisms of thermal regulation is associated with limitation of ecological valence and acquiring of stenothermic features by breed. Optimal thermal conditions for breed are limited by the interval 33-34.5 degrees C. Deviations of temperature by 3-4 degrees C beyond this range have minimum lethal effect at embryonic stage of development and medium effect at the stage of pre-pupa and pupa. Developing at the low bound of the vital range leads to increasing, while developing at the upper bound--to decreasing of body mass, mandibular and hypopharyngeal glands, as well as other organs, which, later, affects the variability of these traits during the adult stage of development. Eliminative and teratogenic efficiency of ecological factors that affect a breed is most often manifested in underdevelopment of wings. However, their size (in case of wing laminas formation). is characterized by relatively low variability and size-dependent asymmetry. Asymmetry variability of wings and other pair organs is expressed through realignment of size excess from right- to left-side one with respect to their increase. Selective elimination by those traits whose emerging probability increases as developmental conditions deviate from the optimal ones promotes restrictions on individual variability. Physiological mechanisms that facilitate adaptability enhancement under conditions of increasing anthropogenic contamination of eivironment and trophic substrates consumed by honey bees, arrear to be toxicants accumulation in rectum and crops' ability to absorb contaminants from nectar in course of its processing to honey.

Physiological performance of the cold-water coral Dendrophyllia cornigera reveals its preference for temperate environments

NASA Astrophysics Data System (ADS)

Gori, Andrea; Reynaud, Stephanie; Orejas, Covadonga; Gili, Josep-Maria; Ferrier-Pagès, Christine

2014-09-01

Cold-water corals (CWCs) are key ecosystem engineers in deep-sea benthic communities around the world. Their distribution patterns are related to several abiotic and biotic factors, of which seawater temperature is arguably one of the most important due to its role in coral physiological processes. The CWC Dendrophyllia cornigera has the particular ability to thrive in several locations in which temperatures range from 11 to 17 °C, but to be apparently absent from most CWC reefs at temperatures constantly below 11 °C. This study thus aimed to assess the thermal tolerance of this CWC species, collected in the Mediterranean Sea at 12 °C, and grown at the three relevant temperatures of 8, 12, and 16 °C. This species displayed thermal tolerance to the large range of seawater temperatures investigated, but growth, calcification, respiration, and total organic carbon (TOC) fluxes severely decreased at 8 °C compared to the in situ temperature of 12 °C. Conversely, no significant differences in calcification, respiration, and TOC fluxes were observed between corals maintained at 12 and 16 °C, suggesting that the fitness of this CWC is higher in temperate rather than cold environments. The capacity to maintain physiological functions between 12 and 16 °C allows D. cornigera to be the most abundant CWC species in deep-sea ecosystems where temperatures are too warm for other CWC species (e.g., Canary Islands). This study also shows that not all CWC species occurring in the Mediterranean Sea (at deep-water temperatures of 12-14 °C) are currently living at their upper thermal tolerance limit.

Physiological spacecraft environment data documentation

NASA Technical Reports Server (NTRS)

1977-01-01

The physiological limits of exposure to environmental parameters encountered during space flight was documented. The environmental limits which have been previously established were described in terms of acceptable physiological changes. The process of coordinating data and assembling the completed data book is described in this report.

Real-time physiological monitoring with distributed networks of sensors and object-oriented programming techniques

NASA Astrophysics Data System (ADS)

Wiesmann, William P.; Pranger, L. Alex; Bogucki, Mary S.

1998-05-01

Remote monitoring of physiologic data from individual high- risk workers distributed over time and space is a considerable challenge. This is often due to an inadequate capability to accurately integrate large amounts of data into usable information in real time. In this report, we have used the vertical and horizontal organization of the 'fireground' as a framework to design a distributed network of sensors. In this system, sensor output is linked through a hierarchical object oriented programing process to accurately interpret physiological data, incorporate these data into a synchronous model and relay processed data, trends and predictions to members of the fire incident command structure. There are several unique aspects to this approach. The first includes a process to account for variability in vital parameter values for each individual's normal physiologic response by including an adaptive network in each data process. This information is used by the model in an iterative process to baseline a 'normal' physiologic response to a given stress for each individual and to detect deviations that indicate dysfunction or a significant insult. The second unique capability of the system orders the information for each user including the subject, local company officers, medical personnel and the incident commanders. Information can be retrieved and used for training exercises and after action analysis. Finally this system can easily be adapted to existing communication and processing links along with incorporating the best parts of current models through the use of object oriented programming techniques. These modern software techniques are well suited to handling multiple data processes independently over time in a distributed network.

A conceptual framework for the emerging discipline of conservation physiology

PubMed Central

Coristine, Laura E.; Robillard, Cassandra M.; Kerr, Jeremy T.; O'Connor, Constance M.; Lapointe, Dominique; Cooke, Steven J.

2014-01-01

Current rates of biodiversity decline are unprecedented and largely attributed to anthropogenic influences. Given the scope and magnitude of conservation issues, policy and management interventions must maximize efficiency and efficacy. The relatively new field of conservation physiology reveals the physiological mechanisms associated with population declines, animal–environment relationships and population or species tolerance thresholds, particularly where these relate to anthropogenic factors that necessitate conservation action. We propose a framework that demonstrates an integrative approach between physiology, conservation and policy, where each can inform the design, conduct and implementation of the other. Each junction of the conservation physiology process has the capacity to foster dialogue that contributes to effective implementation, monitoring, assessment and evaluation. This approach enables effective evaluation and implementation of evidence-based conservation policy and management decisions through a process of ongoing refinement, but may require that scientists (from the disciplines of both physiology and conservation) and policy-makers bridge interdisciplinary knowledge gaps. Here, we outline a conceptual framework that can guide and lead developments in conservation physiology, as well as promote innovative research that fosters conservation-motivated policy. PMID:27293654

Quantitative modeling of multiscale neural activity

NASA Astrophysics Data System (ADS)

Robinson, Peter A.; Rennie, Christopher J.

2007-01-01

The electrical activity of the brain has been observed for over a century and is widely used to probe brain function and disorders, chiefly through the electroencephalogram (EEG) recorded by electrodes on the scalp. However, the connections between physiology and EEGs have been chiefly qualitative until recently, and most uses of the EEG have been based on phenomenological correlations. A quantitative mean-field model of brain electrical activity is described that spans the range of physiological and anatomical scales from microscopic synapses to the whole brain. Its parameters measure quantities such as synaptic strengths, signal delays, cellular time constants, and neural ranges, and are all constrained by independent physiological measurements. Application of standard techniques from wave physics allows successful predictions to be made of a wide range of EEG phenomena, including time series and spectra, evoked responses to stimuli, dependence on arousal state, seizure dynamics, and relationships to functional magnetic resonance imaging (fMRI). Fitting to experimental data also enables physiological parameters to be infered, giving a new noninvasive window into brain function, especially when referenced to a standardized database of subjects. Modifications of the core model to treat mm-scale patchy interconnections in the visual cortex are also described, and it is shown that resulting waves obey the Schroedinger equation. This opens the possibility of classical cortical analogs of quantum phenomena.

Physiologic Reference Ranges for Captive Black-Tailed Prairie Dogs (Cynomys ludovicianus)

PubMed Central

Keckler, M Shannon; Gallardo-Romero, Nadia F; Langham, Gregory L; Damon, Inger K; Karem, Kevin L; Carroll, Darin S

2010-01-01

The black-tailed prairie dog (Cynomys ludovicianus) is a member of the order Rodentia and the family Sciuridae. Ecologically, prairie dogs are a keystone species in prairie ecology. This species is used as an animal model for human gallbladder disease and diseases caused by infection with Clostridium difficile, Yersinia pestis, Francisella tularensis, and most recently, Orthopoxvirus. Despite increasing numbers of prairie dogs used in research and kept as pets, few data are available on their baseline physiology in animal facility housing conditions. To establish baseline physiologic reference ranges, we designed a study using 18 wild-caught black-tailed prairie dogs. Telemetry data were analyzed to establish circadian rhythms for activity and temperature. In addition, hematologic and serum chemistry analyses were performed. Baseline measurements were used to establish the mean for each animal, which then were compiled and analyzed to determine the reference ranges. Here we present physiologic data on serum chemistry and hematology profiles, as well as weight, core body temperature, and daily activity patterns for black-tailed prairie dogs. These results reflect the use of multiple measurements from species- and age-matched prairie dogs and likely will be useful to ecologists, scientists interested in using this animal model in research, and veterinarians caring for pet prairie dogs. PMID:20587156

The physiological origin of task-evoked systemic artefacts in functional near infrared spectroscopy.

PubMed

Kirilina, Evgeniya; Jelzow, Alexander; Heine, Angela; Niessing, Michael; Wabnitz, Heidrun; Brühl, Rüdiger; Ittermann, Bernd; Jacobs, Arthur M; Tachtsidis, Ilias

2012-05-15

A major methodological challenge of functional near-infrared spectroscopy (fNIRS) is its high sensitivity to haemodynamic fluctuations in the scalp. Superficial fluctuations contribute on the one hand to the physiological noise of fNIRS, impairing the signal-to-noise ratio, and may on the other hand be erroneously attributed to cerebral changes, leading to false positives in fNIRS experiments. Here we explore the localisation, time course and physiological origin of task-evoked superficial signals in fNIRS and present a method to separate them from cortical signals. We used complementary fNIRS, fMRI, MR-angiography and peripheral physiological measurements (blood pressure, heart rate, skin conductance and skin blood flow) to study activation in the frontal lobe during a continuous performance task. The General Linear Model (GLM) was applied to analyse the fNIRS data, which included an additional predictor to account for systemic changes in the skin. We found that skin blood volume strongly depends on the cognitive state and that sources of task-evoked systemic signals in fNIRS are co-localized with veins draining the scalp. Task-evoked superficial artefacts were mainly observed in concentration changes of oxygenated haemoglobin and could be effectively separated from cerebral signals by GLM analysis. Based on temporal correlation of fNIRS and fMRI signals with peripheral physiological measurements we conclude that the physiological origin of the systemic artefact is a task-evoked sympathetic arterial vasoconstriction followed by a decrease in venous volume. Since changes in sympathetic outflow accompany almost any cognitive and emotional process, we expect scalp vessel artefacts to be present in a wide range of fNIRS settings used in neurocognitive research. Therefore a careful separation of fNIRS signals originating from activated brain and from scalp is a necessary precondition for unbiased fNIRS brain activation maps. Copyright © 2012 Elsevier Inc. All rights reserved.

A Modern Understanding of the Traditional and Nontraditional Biological Functions of Angiotensin-Converting Enzyme

PubMed Central

Ong, Frank S.; Blackwell, Wendell-Lamar B.; Shah, Kandarp H.; Giani, Jorge F.; Gonzalez-Villalobos, Romer A.; Shen, Xiao Z.; Fuchs, Sebastien

2013-01-01

Angiotensin-converting enzyme (ACE) is a zinc-dependent peptidase responsible for converting angiotensin I into the vasoconstrictor angiotensin II. However, ACE is a relatively nonspecific peptidase that is capable of cleaving a wide range of substrates. Because of this, ACE and its peptide substrates and products affect many physiologic processes, including blood pressure control, hematopoiesis, reproduction, renal development, renal function, and the immune response. The defining feature of ACE is that it is composed of two homologous and independently catalytic domains, the result of an ancient gene duplication, and ACE-like genes are widely distributed in nature. The two ACE catalytic domains contribute to the wide substrate diversity of ACE and, by extension, the physiologic impact of the enzyme. Several studies suggest that the two catalytic domains have different biologic functions. Recently, the X-ray crystal structure of ACE has elucidated some of the structural differences between the two ACE domains. This is important now that ACE domain-specific inhibitors have been synthesized and characterized. Once widely available, these reagents will undoubtedly be powerful tools for probing the physiologic actions of each ACE domain. In turn, this knowledge should allow clinicians to envision new therapies for diseases not currently treated with ACE inhibitors. PMID:23257181

Energy Expenditure and Metabolic Changes of Free-Flying Migrating Northern Bald Ibis.

PubMed

Bairlein, Franz; Fritz, Johannes; Scope, Alexandra; Schwendenwein, Ilse; Stanclova, Gabriela; van Dijk, Gertjan; Meijer, Harro A J; Verhulst, Simon; Dittami, John

2015-01-01

Many migrating birds undertake extraordinary long flights. How birds are able to perform such endurance flights of over 100-hour durations is still poorly understood. We examined energy expenditure and physiological changes in Northern Bald Ibis Geronticus eremite during natural flights using birds trained to follow an ultra-light aircraft. Because these birds were tame, with foster parents, we were able to bleed them immediately prior to and after each flight. Flight duration was experimentally designed ranging between one and almost four hours continuous flights. Energy expenditure during flight was estimated using doubly-labelled-water while physiological properties were assessed through blood chemistry including plasma metabolites, enzymes, electrolytes, blood gases, and reactive oxygen compounds. Instantaneous energy expenditure decreased with flight duration, and the birds appeared to balance aerobic and anaerobic metabolism, using fat, carbohydrate and protein as fuel. This made flight both economic and tolerable. The observed effects resemble classical exercise adaptations that can limit duration of exercise while reducing energetic output. There were also in-flight benefits that enable power output variation from cruising to manoeuvring. These adaptations share characteristics with physiological processes that have facilitated other athletic feats in nature and might enable the extraordinary long flights of migratory birds as well.

Comparison of PIV with 4D-Flow in a physiological accurate flow phantom

NASA Astrophysics Data System (ADS)

Sansom, Kurt; Balu, Niranjan; Liu, Haining; Aliseda, Alberto; Yuan, Chun; Canton, Maria De Gador

2016-11-01

Validation of 4D MRI flow sequences with planar particle image velocimetry (PIV) is performed in a physiologically-accurate flow phantom. A patient-specific phantom of a carotid artery is connected to a pulsatile flow loop to simulate the 3D unsteady flow in the cardiovascular anatomy. Cardiac-cycle synchronized MRI provides time-resolved 3D blood velocity measurements in clinical tool that is promising but lacks a robust validation framework. PIV at three different Reynolds numbers (540, 680, and 815, chosen based on +/- 20 % of the average velocity from the patient-specific CCA waveform) and four different Womersley numbers (3.30, 3.68, 4.03, and 4.35, chosen to reflect a physiological range of heart rates) are compared to 4D-MRI measurements. An accuracy assessment of raw velocity measurements and a comparison of estimated and measureable flow parameters such as wall shear stress, fluctuating velocity rms, and Lagrangian particle residence time, will be presented, with justification for their biomechanics relevance to the pathophysiology of arterial disease: atherosclerosis and intimal hyperplasia. Lastly, the framework is applied to a new 4D-Flow MRI sequence and post processing techniques to provide a quantitative assessment with the benchmarked data. Department of Education GAANN Fellowship.

Comparative Proteomic Analysis of Differentially Expressed Proteins Induced by Hydrogen Sulfide in Spinacia oleracea Leaves

PubMed Central

Chen, Juan; Liu, Ting-Wu; Hu, Wen-Jun; Simon, Martin; Wang, Wen-Hua; Chen, Juan; Liu, Xiang; Zheng, Hai-Lei

2014-01-01

Hydrogen sulfide (H2S), as a potential gaseous messenger molecule, has been suggested to play important roles in a wide range of physiological processes in plants. The aim of present study was to investigate which set of proteins is involved in H2S-regulated metabolism or signaling pathways. Spinacia oleracea seedlings were treated with 100 µM NaHS, a donor of H2S. Changes in protein expression profiles were analyzed by 2-D gel electrophoresis coupled with MALDI-TOF MS. Over 1000 protein spots were reproducibly resolved, of which the abundance of 92 spots was changed by at least 2-fold (sixty-five were up-regulated, whereas 27 were down-regulated). These proteins were functionally divided into 9 groups, including energy production and photosynthesis, cell rescue, development and cell defense, substance metabolism, protein synthesis and folding, cellular signal transduction. Further, we found that these proteins were mainly localized in cell wall, plasma membrane, chloroplast, mitochondria, nucleus, peroxisome and cytosol. Our results demonstrate that H2S is involved in various cellular and physiological activities and has a distinct influence on photosynthesis, cell defense and cellular signal transduction in S. oleracea leaves. These findings provide new insights into proteomic responses in plants under physiological levels of H2S. PMID:25181351

Sensor Systems for Space Life Sciences

NASA Technical Reports Server (NTRS)

Somps, Chris J.; Hines, John W.; Connolly, John P. (Technical Monitor)

1995-01-01

Sensors 2000! (S2K!) is a NASA Ames Research Center engineering initiative designed to provide biosensor and bio-instrumentation systems technology expertise to NASA's life sciences spaceflight programs. S2K! covers the full spectrum of sensor technology applications, ranging from spaceflight hardware design and fabrication to advanced technology development, transfer and commercialization. S2K! is currently developing sensor systems for space biomedical applications on BION (a Russian biosatellite focused on Rhesus Monkey physiology) and NEUROLAB (a Space Shuttle flight devoted to neuroscience). It's Advanced Technology Development-Biosensors (ATD-B) project focuses efforts in five principle areas: biotelemetry Systems, chemical and biological sensors, physiological sensors, advanced instrumentation architectures, and data and information management. Technologies already developed and tested included, application-specific sensors, preamplifier hybrids, modular programmable signal conditioners, power conditioning and distribution systems, and a fully implantable dual channel biotelemeter. Systems currently under development include a portable receiver system compatible with an off-the-shelf analog biotelemeter, a 4 channel digital biotelemetry system which monitors pH, a multichannel, g-processor based PCM biotelemetry system, and hand-held personal monitoring systems. S2K! technology easily lends itself to telescience and telemedicine applications as a front-end measurement and data acquisition device, suitable for obtaining and configuring physiological information, and processing that information under control from a remote location.

Energy Expenditure and Metabolic Changes of Free-Flying Migrating Northern Bald Ibis

PubMed Central

Bairlein, Franz; Fritz, Johannes; Scope, Alexandra; Schwendenwein, Ilse; Stanclova, Gabriela; van Dijk, Gertjan; Meijer, Harro A. J.; Verhulst, Simon

2015-01-01

Many migrating birds undertake extraordinary long flights. How birds are able to perform such endurance flights of over 100-hour durations is still poorly understood. We examined energy expenditure and physiological changes in Northern Bald Ibis Geronticus eremite during natural flights using birds trained to follow an ultra-light aircraft. Because these birds were tame, with foster parents, we were able to bleed them immediately prior to and after each flight. Flight duration was experimentally designed ranging between one and almost four hours continuous flights. Energy expenditure during flight was estimated using doubly-labelled-water while physiological properties were assessed through blood chemistry including plasma metabolites, enzymes, electrolytes, blood gases, and reactive oxygen compounds. Instantaneous energy expenditure decreased with flight duration, and the birds appeared to balance aerobic and anaerobic metabolism, using fat, carbohydrate and protein as fuel. This made flight both economic and tolerable. The observed effects resemble classical exercise adaptations that can limit duration of exercise while reducing energetic output. There were also in-flight benefits that enable power output variation from cruising to manoeuvring. These adaptations share characteristics with physiological processes that have facilitated other athletic feats in nature and might enable the extraordinary long flights of migratory birds as well. PMID:26376193

Physiological changes induced in bacteria following pH stress as a model for space research

NASA Astrophysics Data System (ADS)

Baatout, Sarah; Leys, Natalie; Hendrickx, Larissa; Dams, Annik; Mergeay, Max

2007-02-01

The physiology of the environmental bacterium Cupriavidus metallidurans CH34 (previously Ralstonia metallidurans) is being studied in comparison to the clinical model bacterium Escherichia coli in order to understand its behaviour and resistance under extreme conditions (pH, temperature, etc.). This knowledge is of importance in the light of the potential use and interest of this strain for space biology and bioremediation. Flow cytometry provides powerful means to measure a wide range of cell characteristics in microbiological research. In order to estimate physiological changes associated with pH stress, flow cytometry was employed to estimate the extent of damage on cell size, membrane integrity and potential, and production of superoxides in the two bacterial strains. Suspensions of C. metallidurans and E. coli were submitted to a 1-h pH stress (2 to 12). For flow cytometry, fluorochromes, including propidium iodide, 3, 3'-dihexyloxacarbocyanine iodide and hydroethidine were chosen as analytical parameters for identifying the physiological state and the overall fitness of individual cells. A physiologic state of the bacterial population was assessed with a Coulter EPICS XL analyser based on the differential uptakes of these fluorescent stains. C. metallidurans cells exhibited a different staining intensity than E. coli cells. For both bacterial strains, the physiological status was only slightly affected between pH 6 and 8 in comparison with pH 7 which represents the reference pH. Moderate physiological damage could be observed at pH 4 and 5 as well as at pH 9 in both strains. At pH 2, 10 and 12, membrane permeability and potential and superoxide anion production were increased to high levels showing dramatic physiological changes. It is apparent that a range of significant physiological alterations occurs after pH stress. Fluorescent staining methods coupled with flow cytometry are useful and complementary for monitoring physiological changes induced not only by pH stress but also temperature and oxidative stress, radiation, pressure as well as space stress.

In Vitro Measurements of Metabolism for Application in Pharmacokinetic Modeling

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

Lipscomb, John C.; Poet, Torka S.

2008-04-01

Abstract Human risk and exposure assessments require dosimetry information. Species-specific tissue dose response will be driven by physiological and biochemical processes. While metabolism and pharmacokinetic data are often not available in humans, they are much more available in laboratory animals; metabolic rate constants can be readily derived in vitro. The physiological differences between laboratory animals and humans are known. Biochemical processes, especially metabolism, can be measured in vitro and extrapolated to account for in vivo metabolism through clearance models or when linked to a physiologically based biological (PBPK) model to describe the physiological processes, such as drug delivery to themore » metabolic organ. This review focuses on the different organ, cellular, and subcellular systems that can be used to measure in vitro metabolic rate constants and how that data is extrapolated to be used in biokinetic modeling.« less

Physiological mechanisms of thermoregulation in reptiles: a review.

PubMed

Seebacher, Frank; Franklin, Craig E

2005-11-01

The thermal dependence of biochemical reaction rates means that many animals regulate their body temperature so that fluctuations in body temperature are small compared to environmental temperature fluctuations. Thermoregulation is a complex process that involves sensing of the environment, and subsequent processing of the environmental information. We suggest that the physiological mechanisms that facilitate thermoregulation transcend phylogenetic boundaries. Reptiles are primarily used as model organisms for ecological and evolutionary research and, unlike in mammals, the physiological basis of many aspects in thermoregulation remains obscure. Here, we review recent research on regulation of body temperature, thermoreception, body temperature set-points, and cardiovascular control of heating and cooling in reptiles. The aim of this review is to place physiological thermoregulation of reptiles in a wider phylogenetic context. Future research on reptilian thermoregulation should focus on the pathways that connect peripheral sensing to central processing which will ultimately lead to the thermoregulatory response.

Neural and neurochemical basis of reinforcement-guided decision making.

PubMed

Khani, Abbas; Rainer, Gregor

2016-08-01

Decision making is an adaptive behavior that takes into account several internal and external input variables and leads to the choice of a course of action over other available and often competing alternatives. While it has been studied in diverse fields ranging from mathematics, economics, ecology, and ethology to psychology and neuroscience, recent cross talk among perspectives from different fields has yielded novel descriptions of decision processes. Reinforcement-guided decision making models are based on economic and reinforcement learning theories, and their focus is on the maximization of acquired benefit over a defined period of time. Studies based on reinforcement-guided decision making have implicated a large network of neural circuits across the brain. This network includes a wide range of cortical (e.g., orbitofrontal cortex and anterior cingulate cortex) and subcortical (e.g., nucleus accumbens and subthalamic nucleus) brain areas and uses several neurotransmitter systems (e.g., dopaminergic and serotonergic systems) to communicate and process decision-related information. This review discusses distinct as well as overlapping contributions of these networks and neurotransmitter systems to the processing of decision making. We end the review by touching on neural circuitry and neuromodulatory regulation of exploratory decision making. Copyright © 2016 the American Physiological Society.

Control of the exercise hyperpnoea in humans: a modeling perspective.

PubMed

Ward, S A

2000-09-01

Models of the exercise hyperpnoea have classically incorporated elements of proportional feedback (carotid and medullary chemosensory) and feedforward (central and/or peripheral neurogenic) control. However, the precise details of the control process remain unresolved, reflecting in part both technical and interpretational limitations inherent in isolating putative control mechanisms in the intact human, and also the challenges to linear control theory presented by multiple-input integration, especially with regard to the ventilatory and gas-exchange complexities encountered at work rates which engender a metabolic acidosis. While some combination of neurogenic, chemoreflex and circulatory-coupled processes are likely to contribute to the control, the system appears to evidence considerable redundancy. This, coupled with the lack of appreciable error signals in the mean levels of arterial blood gas tensions and pH over a wide range of work rates, has motivated the formulation of innovative control models that reflect not only spatial interactions but also temporal interactions (i.e. memory). The challenge is to discriminate between robust competing control models that: (a) integrate such processes within plausible physiological equivalents; and (b) account for both the dynamic and steady-state system response over a range of exercise intensities. Such models are not yet available.

DigitalHuman (DH): An Integrative Mathematical Model ofHuman Physiology

NASA Technical Reports Server (NTRS)

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

Physiological responses to social and nonsocial stimuli in neurotypical adults with high and low levels of autistic traits: implications for understanding nonsocial drive in autism spectrum disorders.

PubMed

Singleton, Clarence J; Ashwin, Chris; Brosnan, Mark

2014-12-01

Researchers have suggested that the two primary cognitive features of autism spectrum disorder (ASD), a drive toward nonsocial processing and a reduced drive toward social processing, may be unrelated to each other in the neurotypical (NT) population and may therefore require separate explanations. Drive toward types of processing may be related to physiological arousal to categories of stimuli, such as social (e.g., faces) or nonsocial (e.g., trains). This study investigated how autistic traits in an NT population might relate to differences in physiological responses to nonsocial compared with social stimuli. NT participants were recruited to examine these differences in those with high vs. low degrees of ASD traits. Forty-six participants (21 male, 25 female) completed the Autism Spectrum Quotient (AQ) to measure ASD traits before viewing a series of 24 images while skin conductance response (SCR) was recorded. Images included six nonsocial, six social, six face-like cartoons, and six nonsocial (relating to participants' personal interests). Analysis revealed that those with a higher AQ had significantly greater SCR arousal to nonsocial stimuli than those with a low AQ, and the higher the AQ, the greater the difference between SCR arousal to nonsocial and social stimuli. This is the first study to identify the relationship between AQ and physiological response to nonsocial stimuli, and a relationship between physiological response to both social and nonsocial stimuli, suggesting that physiological response may underlie the atypical drive toward nonsocial processing seen in ASD, and that at the physiological level at least the social and nonsocial in ASD may be related to one another. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.

Effect of saliva on physical food properties in fat texture perception.

PubMed

Kupirovič, Urška Pivk; Elmadfa, Ibrahim; Juillerat, Marcel-Alexandre; Raspor, Peter

2017-04-13

Sensory properties of food drive our food choices and it is generally accepted that lipids greatly contribute to the sensory properties of many foods and consequently to eating pleasure. Many studies have investigated the mechanisms of the fat perception. Unfortunately they used a variety of methods and products, thereby making generalization very difficult. The mechanism of fat perception in oral cavity is combined of several processes. Lipid composition and its properties strongly influence food structure. During consumption food is exposed to a range of in-mouth processing steps. Oral sensation of fat texture changes with time, from a first bite to chewing, while mixing with saliva, up to swallowing and even after swallowing. The present work reviews many aspects of fat texture perception from physical chemistry to physiology. Understanding the underlying mechanisms of in-mouth lipid processing would provide new concepts to produce low-fat food products with full-fat perception.

Multiscale analysis of information dynamics for linear multivariate processes.

PubMed

Faes, Luca; Montalto, Alessandro; Stramaglia, Sebastiano; Nollo, Giandomenico; Marinazzo, Daniele

2016-08-01

In the study of complex physical and physiological systems represented by multivariate time series, an issue of great interest is the description of the system dynamics over a range of different temporal scales. While information-theoretic approaches to the multiscale analysis of complex dynamics are being increasingly used, the theoretical properties of the applied measures are poorly understood. This study introduces for the first time a framework for the analytical computation of information dynamics for linear multivariate stochastic processes explored at different time scales. After showing that the multiscale processing of a vector autoregressive (VAR) process introduces a moving average (MA) component, we describe how to represent the resulting VARMA process using statespace (SS) models and how to exploit the SS model parameters to compute analytical measures of information storage and information transfer for the original and rescaled processes. The framework is then used to quantify multiscale information dynamics for simulated unidirectionally and bidirectionally coupled VAR processes, showing that rescaling may lead to insightful patterns of information storage and transfer but also to potentially misleading behaviors.

[Acidophilic methanogens and their applications in anaerobic digestion].

PubMed

Guo, Xiao-Hui; Wu, Wei-Xiang; Han, Zhi-Ying; Shi, De-Zhi

2011-02-01

Methanogens play an important role in global carbon cycle. There exists a range of unknown methanogenic archaea in acidic peat lands, among which, acidophilic methanogens have attracted increasing research interests because of their special metabolic characteristics. To introduce acidophilic methanogens in the anaerobic digestion process of high concentration organic wastes or waste water could essentially overcome the inhibition of acid accumulation on the methanogens and help reduce the operation cost, broadening the industrial application of anaerobic bio-treatment technology. In this paper, we reviewed the recent researches on acidophilic methanogens, with the focus on enrichment and isolation methods, physiological and biochemical characters, metabolic characteristics, and application of molecular biology. The potential applications of acidophilic methanogens in anaerobic digestion process were analyzed and proposed, and the directions for further researches were suggested.

Emerging Role of Sensory Perception in Aging and Metabolism.

PubMed

Riera, Celine E; Dillin, Andrew

2016-05-01

Sensory perception comprises gustatory (taste) and olfactory (smell) modalities as well as somatosensory (pain, heat, and tactile mechanosensory) inputs, which are detected by a multitude of sensory receptors. These sensory receptors are contained in specialized ciliated neurons where they detect changes in environmental conditions and participate in behavioral decisions ranging from food choice to avoiding harmful conditions, thus insuring basic survival in metazoans. Recent genetic studies, however, indicate that sensory perception plays additional physiological functions, notably influencing energy homeostatic processes and longevity through neuronal circuits originating from sensory tissues. Here we review how these findings are redefining metabolic signaling and establish a prominent role of sensory neuroendocrine processes in controlling health span and lifespan, with a goal of translating this knowledge towards managing age-associated diseases. Copyright © 2016. Published by Elsevier Ltd.

Spinning Disk Confocal Imaging of Neutrophil Migration in Zebrafish

PubMed Central

Lam, Pui-ying; Fischer, Robert S; Shin, William D.; Waterman, Clare M; Huttenlocher, Anna

2014-01-01

Live-cell imaging techniques have been substantially improved due to advances in confocal microscopy instrumentation coupled with ultrasensitive detectors. The spinning disk confocal system is capable of generating images of fluorescent live samples with broad dynamic range and high temporal and spatial resolution. The ability to acquire fluorescent images of living cells in vivo on a millisecond timescale allows the dissection of biological processes that have not previously been visualized in a physiologically relevant context. In vivo imaging of rapidly moving cells such as neutrophils can be technically challenging. In this chapter, we describe the practical aspects of imaging neutrophils in zebrafish embryos using spinning disk confocal microscopy. Similar setups can also be applied to image other motile cell types and signaling processes in translucent animals or tissues. PMID:24504955

[Climatic factors influencing the performance of cattle and buffalos in Egypt].

PubMed

Legel, S

1979-01-01

Previous analogous investigations of climatic factors influencing the performance of cattle in Syria were continued for Egypt between August 1975 and July 1977. Temperature and humidity data were recorded and related to standard physiological compatibility ranges for cattle and buffalos, respectively. The values found for the two test years largely agreed. 23.3% of the average temperatures of the two years were above the 0 to 24 degrees C temperature range, which is physiologically compatible. Only 28.8% of the total hours were within the optimum temperature range for cattle and buffalos. The values of the relative humidity in the first year were up to 38.5% within the optimum compatibility range, whereas 11.0% were within the too dry and 50.5% within the too moist range. The percentage increased when the animals were in direct sunshine, which reduced their performance.

Microparticles: A New Perspective in Central Nervous System Disorders

PubMed Central

Schindler, Stephanie M.; Little, Jonathan P.

2014-01-01

Microparticles (MPs) are a heterogeneous population of small cell-derived vesicles, ranging in size from 0.1 to 1 μm. They contain a variety of bioactive molecules, including proteins, biolipids, and nucleic acids, which can be transferred between cells without direct cell-to-cell contact. Consequently, MPs represent a novel form of intercellular communication, which could play a role in both physiological and pathological processes. Growing evidence indicates that circulating MPs contribute to the development of cancer, inflammation, and autoimmune and cardiovascular diseases. Most cell types of the central nervous system (CNS) have also been shown to release MPs, which could be important for neurodevelopment, CNS maintenance, and pathologies. In disease, levels of certain MPs appear elevated; therefore, they may serve as biomarkers allowing for the development of new diagnostic tools for detecting the early stages of CNS pathologies. Quantification and characterization of MPs could also provide useful information for making decisions on treatment options and for monitoring success of therapies, particularly for such difficult-to-treat diseases as cerebral malaria, multiple sclerosis, and Alzheimer's disease. Overall, studies on MPs in the CNS represent a novel area of research, which promises to expand the knowledge on the mechanisms governing some of the physiological and pathophysiological processes of the CNS. PMID:24860829

Metabolic and functional characterization of effects of developmental temperature in Drosophila melanogaster.

PubMed

Schou, Mads F; Kristensen, Torsten N; Pedersen, Anders; Karlsson, B Göran; Loeschcke, Volker; Malmendal, Anders

2017-02-01

The ability of ectotherms to respond to changes in their thermal environment through plastic mechanisms is central to their adaptive capability. However, we still lack knowledge on the physiological and functional responses by which ectotherms acclimate to temperatures during development, and in particular, how physiological stress at extreme temperatures may counteract beneficial acclimation responses at benign temperatures. We exposed Drosophila melanogaster to 10 developmental temperatures covering their entire permissible temperature range. We obtained metabolic profiles and reaction norms for several functional traits: egg-to-adult viability, developmental time, and heat and cold tolerance. Females were more heat tolerant than males, whereas no sexual dimorphism was found in cold tolerance. A group of metabolites, mainly free amino acids, had linear reaction norms. Several energy-carrying molecules, as well as some sugars, showed distinct inverted U-shaped norms of reaction across the thermal range, resulting in a positive correlation between metabolite intensities and egg-to-adult viability. At extreme temperatures, low levels of these metabolites were interpreted as a response characteristic of costs of homeostatic perturbations. Our results provide novel insights into a range of metabolites reported to be central for the acclimation response and suggest several new candidate metabolites. Low and high temperatures result in different adaptive physiological responses, but they also have commonalities likely to be a result of the failure to compensate for the physiological stress. We suggest that the regulation of metabolites that are tightly connected to the performance curve is important for the ability of ectotherms to cope with variation in temperature. Copyright © 2017 the American Physiological Society.

Physiology, Biochemistry, and Applications of F420- and Fo-Dependent Redox Reactions

PubMed Central

Ahmed, F. Hafna; Mohamed, A. Elaaf; Lee, Brendon M.; Pandey, Gunjan; Warden, Andrew C.; Scott, Colin; Oakeshott, John G.; Taylor, Matthew C.

2016-01-01

SUMMARY 5-Deazaflavin cofactors enhance the metabolic flexibility of microorganisms by catalyzing a wide range of challenging enzymatic redox reactions. While structurally similar to riboflavin, 5-deazaflavins have distinctive and biologically useful electrochemical and photochemical properties as a result of the substitution of N-5 of the isoalloxazine ring for a carbon. 8-Hydroxy-5-deazaflavin (Fo) appears to be used for a single function: as a light-harvesting chromophore for DNA photolyases across the three domains of life. In contrast, its oligoglutamyl derivative F420 is a taxonomically restricted but functionally versatile cofactor that facilitates many low-potential two-electron redox reactions. It serves as an essential catabolic cofactor in methanogenic, sulfate-reducing, and likely methanotrophic archaea. It also transforms a wide range of exogenous substrates and endogenous metabolites in aerobic actinobacteria, for example mycobacteria and streptomycetes. In this review, we discuss the physiological roles of F420 in microorganisms and the biochemistry of the various oxidoreductases that mediate these roles. Particular focus is placed on the central roles of F420 in methanogenic archaea in processes such as substrate oxidation, C1 pathways, respiration, and oxygen detoxification. We also describe how two F420-dependent oxidoreductase superfamilies mediate many environmentally and medically important reactions in bacteria, including biosynthesis of tetracycline and pyrrolobenzodiazepine antibiotics by streptomycetes, activation of the prodrugs pretomanid and delamanid by Mycobacterium tuberculosis, and degradation of environmental contaminants such as picrate, aflatoxin, and malachite green. The biosynthesis pathways of Fo and F420 are also detailed. We conclude by considering opportunities to exploit deazaflavin-dependent processes in tuberculosis treatment, methane mitigation, bioremediation, and industrial biocatalysis. PMID:27122598

Physiology, Biochemistry, and Applications of F420- and Fo-Dependent Redox Reactions.

PubMed

Greening, Chris; Ahmed, F Hafna; Mohamed, A Elaaf; Lee, Brendon M; Pandey, Gunjan; Warden, Andrew C; Scott, Colin; Oakeshott, John G; Taylor, Matthew C; Jackson, Colin J

2016-06-01

5-Deazaflavin cofactors enhance the metabolic flexibility of microorganisms by catalyzing a wide range of challenging enzymatic redox reactions. While structurally similar to riboflavin, 5-deazaflavins have distinctive and biologically useful electrochemical and photochemical properties as a result of the substitution of N-5 of the isoalloxazine ring for a carbon. 8-Hydroxy-5-deazaflavin (Fo) appears to be used for a single function: as a light-harvesting chromophore for DNA photolyases across the three domains of life. In contrast, its oligoglutamyl derivative F420 is a taxonomically restricted but functionally versatile cofactor that facilitates many low-potential two-electron redox reactions. It serves as an essential catabolic cofactor in methanogenic, sulfate-reducing, and likely methanotrophic archaea. It also transforms a wide range of exogenous substrates and endogenous metabolites in aerobic actinobacteria, for example mycobacteria and streptomycetes. In this review, we discuss the physiological roles of F420 in microorganisms and the biochemistry of the various oxidoreductases that mediate these roles. Particular focus is placed on the central roles of F420 in methanogenic archaea in processes such as substrate oxidation, C1 pathways, respiration, and oxygen detoxification. We also describe how two F420-dependent oxidoreductase superfamilies mediate many environmentally and medically important reactions in bacteria, including biosynthesis of tetracycline and pyrrolobenzodiazepine antibiotics by streptomycetes, activation of the prodrugs pretomanid and delamanid by Mycobacterium tuberculosis, and degradation of environmental contaminants such as picrate, aflatoxin, and malachite green. The biosynthesis pathways of Fo and F420 are also detailed. We conclude by considering opportunities to exploit deazaflavin-dependent processes in tuberculosis treatment, methane mitigation, bioremediation, and industrial biocatalysis. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

A stand-alone tree demography and landscape structure module for Earth system models: integration with global forest data

NASA Astrophysics Data System (ADS)

Haverd, V.; Smith, B.; Nieradzik, L. P.; Briggs, P. R.

2014-02-01

Poorly constrained rates of biomass turnover are a key limitation of Earth system models (ESM). In light of this, we recently proposed a new approach encoded in a model called Populations-Order-Physiology (POP), for the simulation of woody ecosystem stand dynamics, demography and disturbance-mediated heterogeneity. POP is suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any ESM. POP bridges the gap between first generation Dynamic Vegetation Models (DVMs) with simple large-area parameterisations of woody biomass (typically used in current ESMs) and complex second generation DVMs, that explicitly simulate demographic processes and landscape heterogeneity of forests. The key simplification in the POP approach, compared with second-generation DVMs, is to compute physiological processes such as assimilation at grid-scale (with CABLE or a similar land surface model), but to partition the grid-scale biomass increment among age classes defined at sub grid-scale, each subject to its own dynamics. POP was successfully demonstrated along a savanna transect in northern Australia, replicating the effects of strong rainfall and fire disturbance gradients on observed stand productivity and structure. Here, we extend the application of POP to a range of forest types around the globe, employing paired observations of stem biomass and density from forest inventory data to calibrate model parameters governing stand demography and biomass evolution. The calibrated POP model is then coupled to the CABLE land surface model and the combined model (CABLE-POP) is evaluated against leaf-stem allometry observations from forest stands ranging in age from 3 to 200 yr. Results indicate that simulated biomass pools conform well with observed allometry. We conclude that POP represents a preferable alternative to large-area parameterisations of woody biomass turnover, typically used in current ESMs.

The Central Role of PhEIN2 in Ethylene Responses throughout Plant Development in Petunia1

PubMed Central

Shibuya, Kenichi; Barry, Kristin G.; Ciardi, Joseph A.; Loucas, Holly M.; Underwood, Beverly A.; Nourizadeh, Saeid; Ecker, Joseph R.; Klee, Harry J.; Clark, David G.

2004-01-01

The plant hormone ethylene regulates many aspects of growth and development. Loss-of-function mutations in ETHYLENE INSENSITIVE2 (EIN2) result in ethylene insensitivity in Arabidopsis, indicating an essential role of EIN2 in ethylene signaling. However, little is known about the role of EIN2 in species other than Arabidopsis. To gain a better understanding of EIN2, a petunia (Petunia × hybrida cv Mitchell Diploid [MD]) homolog of the Arabidopsis EIN2 gene (PhEIN2) was isolated, and the role of PhEIN2 was analyzed in a wide range of plant responses to ethylene, many that do not occur in Arabidopsis. PhEIN2 mRNA was present at varying levels in tissues examined, and the PhEIN2 expression decreased after ethylene treatment in petals. These results indicate that expression of PhEIN2 mRNA is spatially and temporally regulated in petunia during plant development. Transgenic petunia plants with reduced PhEIN2 expression were compared to wild-type MD and ethylene-insensitive petunia plants expressing the Arabidopsis etr1-1 gene for several physiological processes. Both PhEIN2 and etr1-1 transgenic plants exhibited significant delays in flower senescence and fruit ripening, inhibited adventitious root and seedling root hair formation, premature death, and increased hypocotyl length in seedling ethylene response assays compared to MD. Moderate or strong levels of reduction in ethylene sensitivity were achieved with expression of both etr1-1 and PhEIN2 transgenes, as measured by downstream expression of PhEIL1. These results demonstrate that PhEIN2 mediates ethylene signals in a wide range of physiological processes and also indicate the central role of EIN2 in ethylene signal transduction. PMID:15466231

Ontology of physics for biology: representing physical dependencies as a basis for biological processes.

PubMed

Cook, Daniel L; Neal, Maxwell L; Bookstein, Fred L; Gennari, John H

2013-12-02

In prior work, we presented the Ontology of Physics for Biology (OPB) as a computational ontology for use in the annotation and representations of biophysical knowledge encoded in repositories of physics-based biosimulation models. We introduced OPB:Physical entity and OPB:Physical property classes that extend available spatiotemporal representations of physical entities and processes to explicitly represent the thermodynamics and dynamics of physiological processes. Our utilitarian, long-term aim is to develop computational tools for creating and querying formalized physiological knowledge for use by multiscale "physiome" projects such as the EU's Virtual Physiological Human (VPH) and NIH's Virtual Physiological Rat (VPR). Here we describe the OPB:Physical dependency taxonomy of classes that represent of the laws of classical physics that are the "rules" by which physical properties of physical entities change during occurrences of physical processes. For example, the fluid analog of Ohm's law (as for electric currents) is used to describe how a blood flow rate depends on a blood pressure gradient. Hooke's law (as in elastic deformations of springs) is used to describe how an increase in vascular volume increases blood pressure. We classify such dependencies according to the flow, transformation, and storage of thermodynamic energy that occurs during processes governed by the dependencies. We have developed the OPB and annotation methods to represent the meaning-the biophysical semantics-of the mathematical statements of physiological analysis and the biophysical content of models and datasets. Here we describe and discuss our approach to an ontological representation of physical laws (as dependencies) and properties as encoded for the mathematical analysis of biophysical processes.

Normal range of human dietary sodium intake: a perspective based on 24-hour urinary sodium excretion worldwide.

PubMed

McCarron, David A; Kazaks, Alexandra G; Geerling, Joel C; Stern, Judith S; Graudal, Niels A

2013-10-01

The recommendation to restrict dietary sodium for management of hypertensive cardiovascular disease assumes that sodium intake exceeds physiologic need, that it can be significantly reduced, and that the reduction can be maintained over time. In contrast, neuroscientists have identified neural circuits in vertebrate animals that regulate sodium appetite within a narrow physiologic range. This study further validates our previous report that sodium intake, consistent with the neuroscience, tracks within a narrow range, consistent over time and across cultures. Peer-reviewed publications reporting 24-hour urinary sodium excretion (UNaV) in a defined population that were not included in our 2009 publication were identified from the medical literature. These datasets were combined with those in our previous report of worldwide dietary sodium consumption. The new data included 129 surveys, representing 50,060 participants. The mean value and range of 24-hour UNaV in each of these datasets were within 1 SD of our previous estimate. The combined mean and normal range of sodium intake of the 129 datasets were nearly identical to that we previously reported (mean = 158.3±22.5 vs. 162.4±22.4 mmol/d). Merging the previous and new datasets (n = 190) yielded sodium consumption of 159.4±22.3 mmol/d (range = 114-210 mmol/d; 2,622-4,830mg/d). Human sodium intake, as defined by 24-hour UNaV, is characterized by a narrow range that is remarkably reproducible over at least 5 decades and across 45 countries. As documented here, this range is determined by physiologic needs rather than environmental factors. Future guidelines should be based on this biologically determined range.

High pressure thermal inactivation of Clostridium botulinum type E endospores – kinetic modeling and mechanistic insights

PubMed Central

Lenz, Christian A.; Reineke, Kai; Knorr, Dietrich; Vogel, Rudi F.

2015-01-01

Cold-tolerant, neurotoxigenic, endospore forming Clostridium (C.) botulinum type E belongs to the non-proteolytic physiological C. botulinum group II, is primarily associated with aquatic environments, and presents a safety risk for seafood. High pressure thermal (HPT) processing exploiting the synergistic effect of pressure and temperature can be used to inactivate bacterial endospores. We investigated the inactivation of C. botulinum type E spores by (near) isothermal HPT treatments at 300–1200 MPa at 30–75°C for 1 s to 10 min. The occurrence of heat and lysozyme susceptible spore fractions after such treatments was determined. The experimental data were modeled to obtain kinetic parameters and represented graphically by isoeffect lines. In contrast to findings for spores of other species and within the range of treatment parameters applied, zones of spore stabilization (lower inactivation than heat treatments alone), large heat susceptible (HPT-induced germinated) or lysozyme-dependently germinable (damaged coat layer) spore fractions were not detected. Inactivation followed first order kinetics. Dipicolinic acid release kinetics allowed for insights into possible inactivation mechanisms suggesting a (poorly effective) physiologic-like (similar to nutrient-induced) germination at ≤450 MPa/≤45°C and non-physiological germination at >500 MPa/>60–70°C. Results of this study support the existence of some commonalities in the HPT inactivation mechanism of C. botulinum type E spores and Bacillus spores although both organisms have significantly different HPT resistance properties. The information presented here contributes to closing the gap in knowledge regarding the HPT inactivation of spore formers relevant to food safety and may help industrial implementation of HPT processing. The markedly lower HPT resistance of C. botulinum type E spores compared with the resistance of spores from other C. botulinum types could allow for the implementation of milder processes without endangering food safety. PMID:26191048

The Physiology of Exercise and the Process of Aging.

ERIC Educational Resources Information Center

Mravetz, Patricia

A physical fitness plan is considered desirable for young people, young adults, and especially older adults. This program for secondary level students focuses on the physiology of exercise and the process of aging, and stresses the need for physical fitness. Specific objectives include the following: (1) to let students become evaluators of their…

Laboratory Exercise: Study of Digestive and Regulatory Processes through the Exploration of Fasted and Postprandial Blood Glucose

ERIC Educational Resources Information Center

Hopper, Mari K.; Maurer, Luke W.

2013-01-01

Digestive physiology laboratory exercises often explore the regulation of enzyme action rather than systems physiology. This laboratory exercise provides a systems approach to digestive and regulatory processes through the exploration of postprandial blood glucose levels. In the present exercise, students enrolled in an undergraduate animal…

Effect of monitoring technique on quality of conservation science.

PubMed

Jewell, Zoe

2013-06-01

Monitoring free-ranging animals in their natural habitat is a keystone of ecosystem conservation and increasingly important in the context of current rates of loss of biological diversity. Data collected from individuals of endangered species inform conservation policies. Conservation professionals assume that these data are reliable-that the animals from whom data are collected are representative of the species in their physiology, ecology, and behavior and of the populations from which they are drawn. In the last few decades, there has been an enthusiastic adoption of invasive techniques for gathering ecological and conservation data. Although these can provide impressive quantities of data, and apparent insights into animal ranges and distributions, there is increasing evidence that these techniques can result in animal welfare problems, through the wide-ranging physiological effects of acute and chronic stress and through direct or indirect injuries or compromised movement. Much less commonly, however, do conservation scientists consider the issue of how these effects may alter the behavior of individuals to the extent that the data they collect could be unreliable. The emerging literature on the immediate and longer-term effects of capture and handling indicate it can no longer be assumed that a wild animal's survival of the process implies the safety of the procedure, that the procedure is ethical, or the scientific validity of the resulting data. I argue that conservation professionals should routinely assess study populations for negative effects of their monitoring techniques and adopt noninvasive approaches for best outcomes not only for the animals, but also for conservation science. © 2013 Society for Conservation Biology.

Exploring the range of climate biome projections for tropical South America: The role of CO2 fertilization and seasonality

NASA Astrophysics Data System (ADS)

Lapola, David M.; Oyama, Marcos D.; Nobre, Carlos A.

2009-09-01

Tropical South America vegetation cover projections for the end of the century differ considerably depending on climate scenario and also on how physiological processes are considered in vegetation models. In this paper we use a potential vegetation model (CPTEC-PVM2) to analyze biome distribution in tropical South America under a range of climate projections and a range of estimates about the effects of increased atmospheric CO2. We show that if the CO2 "fertilization effect" indeed takes place and is maintained in the long term in tropical forests, then it will avoid biome shifts in Amazonia in most of the climate scenarios, even if the effect of CO2 fertilization is halved. However, if CO2 fertilization does not play any important role on tropical forests in the future or if dry season is longer than 4 months (projected by 2/14 GCMs), then there is replacement of large portions of Amazonia by tropical savanna.

Second Generation Crop Yield Models Review

NASA Technical Reports Server (NTRS)

Hodges, T. (Principal Investigator)

1982-01-01

Second generation yield models, including crop growth simulation models and plant process models, may be suitable for large area crop yield forecasting in the yield model development project. Subjective and objective criteria for model selection are defined and models which might be selected are reviewed. Models may be selected to provide submodels as input to other models; for further development and testing; or for immediate testing as forecasting tools. A plant process model may range in complexity from several dozen submodels simulating (1) energy, carbohydrates, and minerals; (2) change in biomass of various organs; and (3) initiation and development of plant organs, to a few submodels simulating key physiological processes. The most complex models cannot be used directly in large area forecasting but may provide submodels which can be simplified for inclusion into simpler plant process models. Both published and unpublished models which may be used for development or testing are reviewed. Several other models, currently under development, may become available at a later date.

Erroneous Arrhenius: Modified Arrhenius model best explains the temperature dependence of ectotherm fitness

PubMed Central

Knies, Jennifer L.; Kingsolver, Joel G.

2013-01-01

The initial rise of fitness that occurs with increasing temperature is attributed to Arrhenius kinetics, in which rates of reaction increase exponentially with increasing temperature. Models based on Arrhenius typically assume single rate-limiting reaction(s) over some physiological temperature range for which all the rate-limiting enzymes are in 100% active conformation. We test this assumption using datasets for microbes that have measurements of fitness (intrinsic rate of population growth) at many temperatures and over a broad temperature range, and for diverse ectotherms that have measurements at fewer temperatures. When measurements are available at many temperatures, strictly Arrhenius kinetics is rejected over the physiological temperature range. However, over a narrower temperature range, we cannot reject strictly Arrhenius kinetics. The temperature range also affects estimates of the temperature dependence of fitness. These results indicate that Arrhenius kinetics only apply over a narrow range of temperatures for ectotherms, complicating attempts to identify general patterns of temperature dependence. PMID:20528477

Erroneous Arrhenius: modified arrhenius model best explains the temperature dependence of ectotherm fitness.

PubMed

Knies, Jennifer L; Kingsolver, Joel G

2010-08-01

The initial rise of fitness that occurs with increasing temperature is attributed to Arrhenius kinetics, in which rates of reaction increase exponentially with increasing temperature. Models based on Arrhenius typically assume single rate-limiting reactions over some physiological temperature range for which all the rate-limiting enzymes are in 100% active conformation. We test this assumption using data sets for microbes that have measurements of fitness (intrinsic rate of population growth) at many temperatures and over a broad temperature range and for diverse ectotherms that have measurements at fewer temperatures. When measurements are available at many temperatures, strictly Arrhenius kinetics are rejected over the physiological temperature range. However, over a narrower temperature range, we cannot reject strictly Arrhenius kinetics. The temperature range also affects estimates of the temperature dependence of fitness. These results indicate that Arrhenius kinetics only apply over a narrow range of temperatures for ectotherms, complicating attempts to identify general patterns of temperature dependence.

A neural model of hierarchical reinforcement learning

PubMed Central

Rasmussen, Daniel; Eliasmith, Chris

2017-01-01

We develop a novel, biologically detailed neural model of reinforcement learning (RL) processes in the brain. This model incorporates a broad range of biological features that pose challenges to neural RL, such as temporally extended action sequences, continuous environments involving unknown time delays, and noisy/imprecise computations. Most significantly, we expand the model into the realm of hierarchical reinforcement learning (HRL), which divides the RL process into a hierarchy of actions at different levels of abstraction. Here we implement all the major components of HRL in a neural model that captures a variety of known anatomical and physiological properties of the brain. We demonstrate the performance of the model in a range of different environments, in order to emphasize the aim of understanding the brain’s general reinforcement learning ability. These results show that the model compares well to previous modelling work and demonstrates improved performance as a result of its hierarchical ability. We also show that the model’s behaviour is consistent with available data on human hierarchical RL, and generate several novel predictions. PMID:28683111

Contrasting extremes in water-related stresses determine species survival

NASA Astrophysics Data System (ADS)

Bartholomeus, R. P.; Witte, J. P. M.; van Bodegom, P. M.; van Dam, J. C.; Aerts, R.

2012-04-01

In temperate climates, soil moisture, in concert with nutrient availability and soil acidity, is the most important environmental filter in determining local plant species composition, as it determines the availability of both oxygen and water to plant roots. These resources are indispensable for meeting the physiological demands of plants. Especially the occurrence of both excessive dry and wet moisture conditions at a particular site has strong implications for the survival of species, because plants need traits that allow them to respond to such counteracting conditions. However, adapting to one stress may go at the cost of the other, i.e. there exists a trade-off in the tolerance for wet conditions and the tolerance for dry conditions. Until now, both large-scale (global) and plot-scale effects of soil moisture conditions on plant species composition have mostly been investigated through indirect environmental measures, which do not include the key soil physical and plant physiological processes in the soil-plant-atmosphere system. Moreover, researchers only determined effects of one of the water-related stresses, i.e. either oxygen or drought stress. In order to quantify both oxygen and drought stress with causal measures, we focused on interacting meteorological, soil physical, microbial, and plant physiological processes in the soil-plant-atmosphere system. We simulated these plant stresses with a novel, process-based approach, incorporating in detail the interacting processes in the soil-plant-atmosphere interface. High variability and extremes in resource availability can be highly detrimental to plant species ('you can only die once'). We show that co-occurrence of oxygen and drought stress reduces the percentage of specialists within a vegetation plot. The percentage of non-specialists within a vegetation plot, however, decreases significantly with increasing stress as long as only one of the stresses prevails, but increases significantly with an increased co-occurrence of oxygen and drought stress. These results confirm earlier suggestions that species that are simultaneously tolerant to multiple stresses, lack full adaptation to each potential stress. Specific adaptations to either oxygen or drought stress thus reduce the adaptive ability to the other stress and increase the impact of the other stress. We further show that the combination of stresses is detrimental particularly to endangered species, while the number of common species within a vegetation plot does not decline with increasing co-occurrence and intensification of oxygen and drought stress. Additionally, our results show significantly smaller tolerance ranges for oxygen and drought stress for endangered species than for common species. Variability in the availability of resources is thus especially detrimental to species with narrow physiological tolerance ranges. Finally, we found that increased rainfall variability in interaction with predicted changes in temperature and CO2, may affect soil moisture conditions and plant oxygen and water demands such, that both oxygen stress and drought stress will intensify due to climate change. Moreover, these stresses will increasingly coincide, causing variable stress conditions. Consequently, more variable and extreme meteorological conditions may decrease the future habitat suitability, especially for specialists and plant species that are presently endangered, which has direct implications for policies to maintain species.

A creatinine biosensor based on admittance measurement

NASA Astrophysics Data System (ADS)

Ching, Congo Tak-Shing; Sun, Tai-Ping; Jheng, Deng-Yun; Tsai, Hou-Wei; Shieh, Hsiu-Li

2015-08-01

Regular check of blood creatinine level is very important as it is a measurement of renal function. Therefore, the objective of this study is to develop a simple and reliable creatinine biosensor based on admittance measurement for precise determination of creatinine. The creatinine biosensor was fabricated with creatinine deiminase immobilized on screen-printed carbon electrodes. Admittance measurement at a specific frequency ranges (22.80 - 84.71 Hz) showed that the biosensor has an excellent linear (r2 > 0.95) response range (50 - 250 uM), which covers the normal physiological and pathological ranges of blood creatinine levels. Intraclass correlation coefficient (ICC) showed that the biosensor has excellent reliability and validity (ICC = 0.98). In conclusion, a simple and reliable creatinine biosensor was developed and it is capable of precisely determining blood creatinine levels in both the normal physiological and pathological ranges.

The effects of host size and temperature on the emergence of Echinoparyphium recurvatum cercariae from Lymnaea peregra under natural light conditions.

PubMed

Morley, N J; Adam, M E; Lewis, J W

2010-09-01

The production of cercariae from their snail host is a fundamental component of transmission success in trematodes. The emergence of Echinoparyphium recurvatum (Trematoda: Echinostomatidae) cercariae from Lymnaea peregra was studied under natural sunlight conditions, using naturally infected snails of different sizes (10-17 mm) within a temperature range of 10-29 degrees C. There was a single photoperiodic circadian cycle of emergence with one peak, which correlated with the maximum diffuse sunlight irradiation. At 21 degrees C the daily number of emerging cercariae increased with increasing host snail size, but variations in cercarial emergence did occur between both individual snails and different days. There was only limited evidence of cyclic emergence patterns over a 3-week period, probably due to extensive snail mortality, particularly those in the larger size classes. Very few cercariae emerged in all snail size classes at the lowest temperature studied (10 degrees C), but at increasingly higher temperatures elevated numbers of cercariae emerged, reaching an optimum between 17 and 25 degrees C. Above this range emergence was reduced. At all temperatures more cercariae emerged from larger snails. Analysis of emergence using the Q10 value, a measure of physiological processes over temperature ranges, showed that between 10 and 21 degrees C (approximately 15 degrees C) Q10 values exceeded 100 for all snail size classes, indicating a substantially greater emergence than would be expected for normal physiological rates. From 14 to 25 degrees C (approximately 20 degrees C) cercarial emergence in most snail size classes showed little change in Q10, although in the smallest size class emergence was still substantially greater than the typical Q10 increase expected over this temperature range. At the highest range of 21-29 degrees C (approximately 25 degrees C), Q10 was much reduced. The importance of these results for cercarial emergence under global climate change is discussed.

The physiological diversity and similarity of ten Quercus species

Treesearch

Shi-Jean S. Sung; M.N. Angelov; R.R. Doong; W.R. Harms; Paul P. Kormanik; C.C. Black

1994-01-01

Based on anatomical, photosynthetic, and biochemical data, the range of physiological differences and similarities was defined for ten Quercus species. There were no correlations between species' site adaptability, leaf anatomy and photosynthetic rate (A). It is concluded from these data that each oak species must be treated individually when incorporated into...

Physiological-Cognitive-Emotional Responses to Defense-Arousing Communication: Overview and Sex Differences.

ERIC Educational Resources Information Center

Gordon, Ronald D.

A 328-item checklist, suitable for the self-reporting of responses to any stimulus event, was administered to 107 upper division college students in an attempt to investigate the physiological-cognitive-emotional responses to defense arousing communication and to discover a greater range of the key features of the phenomena of…

Using time-series intervention analysis to model cow heart rate affected by programmed audio and environmental/physiological

USDA-ARS?s Scientific Manuscript database

This research is the first use of the Box-Jenkins time-series models to describe changes in heart rate (HR) of free-ranging crossbred cows (Bos taurus) receiving both programmed audio cues from directional virtual fencing (DVFTM) devices and non-programmed environmental/physiological cues. The DVFT...

A Proteomic Study of Brassinosteroid Response in Arabidopsis

PubMed Central

Deng, Zhiping; Zhang, Xin; Tang, Wenqiang; Oses-Prieto, Juan A; Suzuki, Nagi; Gendron, Joshua M; Chen, Huanjing; Guan, Shenheng; Chalkley, Robert J.; Peterman, T. Kaye; Burlingame, Alma L.; Wang, Zhi-Yong

2010-01-01

Summary The plant steroid hormones brassinosteroids (BRs) play an important role in a wide range of developmental and physiological processes. How BR signaling regulates diverse processes remains unclear. To understand the molecular details of BR responses, we have performed a proteomic study of BR-regulated proteins in Arabidopsis using two-dimensional difference gel electrophoresis (2-D DIGE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). We identified 42 BR-regulated proteins, which are predicted to play potential roles in BR regulation of specific cellular processes, such as signaling, cytoskeleton rearrangement, vesicle trafficking, and biosynthesis of hormones and vitamins. Analyses of the BR insensitive mutant bri1-116 and BR hypersensitive mutant bzr1-1D identified 5 proteins (PATL1, PATL2, THI1, AtMDAR3 and NADP-ME2) affected by both BR-treatment and in the mutants, suggesting their importance in BR action. Selected proteins were further studied using insertion knockout mutants or immunoblotting. Interestingly, about 80% of the BR-responsive proteins were not identified in previous microarray studies, and direct comparison between protein- and RNA changes in BR mutants revealed a very weak correlation. RT-PCR analysis of selected genes revealed gene-specific kinetic relationships between RNA and protein responses. Furthermore, BR-regulated posttranslational modification of BiP2 protein was detected as spot shifts in 2-D DIGE. This study provides novel insights into the molecular networks that link BR signaling to specific cellular and physiological responses. PMID:17848588

Time to Death after Terminal Withdrawal of Mechanical Ventilation: Specific Respiratory and Physiologic Parameters May Inform Physician Predictions.

PubMed

Long, Ann C; Muni, Sarah; Treece, Patsy D; Engelberg, Ruth A; Nielsen, Elizabeth L; Fitzpatrick, Annette L; Curtis, J Randall

2015-12-01

Discussions about withdrawal of life-sustaining therapies often include family members of critically ill patients. These conversations should address essential components of the dying process, including expected time to death after withdrawal. The study objective was to aid physician communication about the dying process by identifying predictors of time to death after terminal withdrawal of mechanical ventilation. We conducted an observational analysis from a single-center, before-after evaluation of an intervention to improve palliative care. We studied 330 patients who died after terminal withdrawal of mechanical ventilation. Predictors included patient demographics, laboratory, respiratory, and physiologic variables, and medication use. The median time to death for the entire cohort was 0.58 hours (interquartile range (IQR) 0.22-2.25 hours) after withdrawal of mechanical ventilation. Using Cox regression, independent predictors of shorter time to death included higher positive end-expiratory pressure (per 1 cm H2O hazard ratio [HR], 1.07; 95% CI 1.04-1.11); higher static pressure (per 1 cm H2O HR, 1.03; 95% CI 1.01-1.04); extubation prior to death (HR, 1.41; 95% CI 1.06-1.86); and presence of diabetes (HR, 1.75; 95% CI 1.25-2.44). Higher noninvasive mean arterial pressure predicted longer time to death (per 1 mmHg HR, 0.98; 95% CI 0.97-0.99). Comorbid illness and key respiratory and physiologic parameters may inform physician predictions of time to death after withdrawal of mechanical ventilation. An understanding of the predictors of time to death may facilitate discussions with family members of dying patients and improve communication about end-of-life care.

Time to Death after Terminal Withdrawal of Mechanical Ventilation: Specific Respiratory and Physiologic Parameters May Inform Physician Predictions

PubMed Central

Muni, Sarah; Treece, Patsy D.; Engelberg, Ruth A.; Nielsen, Elizabeth L.; Fitzpatrick, Annette L.; Curtis, J. Randall

2015-01-01

Abstract Background: Discussions about withdrawal of life-sustaining therapies often include family members of critically ill patients. These conversations should address essential components of the dying process, including expected time to death after withdrawal. Objectives: The study objective was to aid physician communication about the dying process by identifying predictors of time to death after terminal withdrawal of mechanical ventilation. Methods: We conducted an observational analysis from a single-center, before–after evaluation of an intervention to improve palliative care. We studied 330 patients who died after terminal withdrawal of mechanical ventilation. Predictors included patient demographics, laboratory, respiratory, and physiologic variables, and medication use. Results: The median time to death for the entire cohort was 0.58 hours (interquartile range (IQR) 0.22–2.25 hours) after withdrawal of mechanical ventilation. Using Cox regression, independent predictors of shorter time to death included higher positive end-expiratory pressure (per 1 cm H2O hazard ratio [HR], 1.07; 95% CI 1.04–1.11); higher static pressure (per 1 cm H2O HR, 1.03; 95% CI 1.01–1.04); extubation prior to death (HR, 1.41; 95% CI 1.06–1.86); and presence of diabetes (HR, 1.75; 95% CI 1.25–2.44). Higher noninvasive mean arterial pressure predicted longer time to death (per 1 mmHg HR, 0.98; 95% CI 0.97–0.99). Conclusions: Comorbid illness and key respiratory and physiologic parameters may inform physician predictions of time to death after withdrawal of mechanical ventilation. An understanding of the predictors of time to death may facilitate discussions with family members of dying patients and improve communication about end-of-life care. PMID:26555010

The effect of water temperature and flow on respiration in barnacles: patterns of mass transfer versus kinetic limitation.

PubMed

Nishizaki, Michael T; Carrington, Emily

2014-06-15

In aquatic systems, physiological processes such as respiration, photosynthesis and calcification are potentially limited by the exchange of dissolved materials between organisms and their environment. The nature and extent of physiological limitation is, therefore, likely to be dependent on environmental conditions. Here, we assessed the metabolic sensitivity of barnacles under a range of water temperatures and velocities, two factors that influence their distribution. Respiration rates increased in response to changes in temperature and flow, with an interaction where flow had less influence on respiration at low temperatures, and a much larger effect at high temperatures. Model analysis suggested that respiration is mass transfer limited under conditions of low velocity (<7.5 cm (-1)) and high temperature (20-25°C). In contrast, limitation by uptake reaction kinetics, when the biotic capacity of barnacles to absorb and process oxygen is slower than its physical delivery by mass transport, prevailed at high flows (40-150 cm s(-1)) and low temperatures (5-15°C). Moreover, there are intermediate flow-temperature conditions where both mass transfer and kinetic limitation are important. Behavioral monitoring revealed that barnacles fully extend their cirral appendages at low flows and display abbreviated 'testing' behaviors at high flows, suggesting some form of mechanical limitation. In low flow-high temperature treatments, however, barnacles displayed distinct 'pumping' behaviors that may serve to increase ventilation. Our results suggest that in slow-moving waters, respiration may become mass transfer limited as temperatures rise, whereas faster flows may serve to ameliorate the effects of elevated temperatures. Moreover, these results underscore the necessity for approaches that evaluate the combined effects of multiple environmental factors when examining physiological and behavioral performance. © 2014. Published by The Company of Biologists Ltd.

A physiological and genetic approach to the improvement of tomato (Lycopersicon esculentum Mill. ) fruit soluble solids

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

Damon, S.E.

Physiological processes and the genetic basis determining soluble solids content (SSC) of processing tomato fruit were addressed. Analysis of ({sup 3}H)-(fructosyl)-sucrose translocation in tomato indicates that phloem unloading in the fruit occurs, at least in part, to the apoplast. Apoplastic sucrose, glucose and fructose concentrations were estimated as 1 to 7, 12 to 49 and 8 to 63 millimolar, respectively in tomato fruit pericarp. Short-term uptake of ({sup 14}C)sucrose, -glucose and -fructose in tomato pericarp discs showes first order kinetics over the physiologically relevant concentration range. The uptake of ({sup 14}C)-(glycosyl)-1{prime}fluorosucrose was identical to the rate of ({sup 14}C) sucrosemore » uptake suggesting sucrose may be taken up directly without prior extracellular hydrolysis. Short-term uptake of all three sugars was insensitive to 10 micromolar carbonyl cyanide m-chlorophenylhydrazone and to 10 micromolar p-chloromercuribenzene sulfonic acid. However, long-term accumulation of glucose was sensitive to carbonyl cyanide m-chlorophenylhydrazone. Sugar uptake across the plasmamembrane does not appear to be energy dependent, suggesting that sugar accumulation in the tomato is driven by subsequent intracellular metabolism and/or active uptake at the tonoplast. Fourteen genomic DNA probes and ten restriction endonucleases were used to identify restriction fragment length polymorphisms (RFLPs) useful in the linkage analysis of quantitative trait loci controlling the expression of SSC in a segregating F{sub 2} population from a cross between L. esculentum (UC204B) and L. cheesmanii f. minor, a wild species with high fruit soluble solids. RFLPs were detected between the DNAs of the two tomato species with all 14 probes.« less

Response of ammonium removal to growth and transpiration of Juncus effusus during the treatment of artificial sewage in laboratory-scale wetlands.

PubMed

Wiessner, A; Kappelmeyer, U; Kaestner, M; Schultze-Nobre, L; Kuschk, P

2013-09-01

The correlation between nitrogen removal and the role of the plants in the rhizosphere of constructed wetlands are the subject of continuous discussion, but knowledge is still insufficient. Since the influence of plant growth and physiological activity on ammonium removal has not been well characterized in constructed wetlands so far, this aspect is investigated in more detail in model wetlands under defined laboratory conditions using Juncus effusus for treating an artificial sewage. Growth and physiological activity, such as plant transpiration, have been found to correlate with both the efficiency of ammonium removal within the rhizosphere of J. effusus and the methane formation. The uptake of ammonium by growing plant stocks is within in a range of 45.5%, but under conditions of plant growth stagnation, a further nearly complete removal of the ammonium load points to the likely existence of additional nitrogen removal processes. In this way, a linear correlation between the ammonium concentration inside the rhizosphere and the transpiration of the plant stocks implies that an influence of plant physiological activity on the efficiency of N-removal exists. Furthermore, a linear correlation between methane concentration and plant transpiration has been estimated. The findings indicate a fast response of redox processes to plant activities. Accordingly, not only the influence of plant transpiration activity on the plant-internal convective gas transport, the radial oxygen loss by the plant roots and the efficiency of nitrification within the rhizosphere, but also the nitrogen gas released by phytovolatilization are discussed. The results achieved by using an unplanted control system are different in principle and characterized by a low efficiency of ammonium removal and a high methane enrichment of up to a maximum of 72.7% saturation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Adrenocortical stress responses influence an invasive vertebrate's fitness in an extreme environment

PubMed Central

Jessop, Tim S.; Letnic, Mike; Webb, Jonathan K.; Dempster, Tim

2013-01-01

Continued range expansion into physiologically challenging environments requires invasive species to maintain adaptive phenotypic performance. The adrenocortical stress response, governed in part by glucocorticoid hormones, influences physiological and behavioural responses of vertebrates to environmental stressors. However, any adaptive role of this response in invasive populations that are expanding into extreme environments is currently unclear. We experimentally manipulated the adrenocortical stress response of invasive cane toads (Rhinella marina) to investigate its effect on phenotypic performance and fitness at the species' range front in the Tanami Desert, Australia. Here, toads are vulnerable to overheating and dehydration during the annual hot–dry season and display elevated plasma corticosterone levels indicative of severe environmental stress. By comparing unmanipulated control toads with toads whose adrenocortical stress response was manipulated to increase acute physiological stress responsiveness, we found that control toads had significantly reduced daily evaporative water loss and higher survival relative to the experimental animals. The adrenocortical stress response hence appears essential in facilitating complex phenotypic performance and setting fitness trajectories of individuals from invasive species during range expansion. PMID:23945686

Master of all trades: thermal acclimation and adaptation of cardiac function in a broadly distributed marine invasive species, the European green crab, Carcinus maenas.

PubMed

Tepolt, Carolyn K; Somero, George N

2014-04-01

As global warming accelerates, there is increasing concern about how ecosystems may change as a result of species loss and replacement. Here, we examined the thermal physiology of the European green crab (Carcinus maenas Linnaeus 1758), a globally invasive species, along three parallel thermal gradients in its native and invasive ranges. At each site, we assessed cardiac physiology to determine heat and cold tolerance and acclimatory plasticity. We found that, overall, the species is highly tolerant of both heat and cold, and that it survives higher temperatures than co-occurring native marine crustaceans. Further, we found that both heat and cold tolerance are plastic in response to short-term acclimation (18-31 days at either 5 or 25°C). Comparing patterns within ranges, we found latitudinal gradients in thermal tolerance in the native European range and in the invasive range in eastern North America. This pattern is strongest in the native range, and likely evolved there. Because of a complicated invasion history, the latitudinal pattern in the eastern North American invasive range may be due either to rapid adaptation post-invasion or to adaptive differences between the ancestral populations that founded the invasion. Overall, the broad thermal tolerance ranges of green crabs, which may facilitate invasion of novel habitats, derive from high inherent eurythermality and acclimatory plasticity and potentially adaptive differentiation among populations. The highly flexible physiology that results from these capacities may represent the hallmark of a successful invasive species, and may provide a model for success in a changing world.

Measuring salivary analytes from free-ranging monkeys

PubMed Central

Higham, James P.; Vitale, Alison; Rivera, Adaris Mas; Ayala, James E.; Maestripieri, Dario

2014-01-01

Studies of large free-ranging mammals have been revolutionized by non-invasive methods for assessing physiology, which usually involve the measurement of fecal or urinary biomarkers. However, such techniques are limited by numerous factors. To expand the range of physiological variables measurable non-invasively from free-ranging primates, we developed techniques for sampling monkey saliva by offering monkeys ropes with oral swabs sewn on the ends. We evaluated different attractants for encouraging individuals to offer samples, and proportions of individuals in different age/sex categories willing to give samples. We tested the saliva samples we obtained in three commercially available assays: cortisol, Salivary Alpha Amylase, and Secretory Immunoglobulin A. We show that habituated free-ranging rhesus macaques will give saliva samples voluntarily without training, with 100% of infants, and over 50% of adults willing to chew on collection devices. Our field methods are robust even for analytes that show poor recovery from cotton, and/or that have concentrations dependent on salivary flow rate. We validated the cortisol and SAA assays for use in rhesus macaques by showing aspects of analytical validation, such as that samples dilute linearly and in parallel to assay standards. We also found that values measured correlated with biologically meaningful characteristics of sampled individuals (age and dominance rank). The SIgA assay tested did not react to samples. Given the wide range of analytes measurable in saliva but not in feces or urine, our methods considerably improve our ability to study physiological aspects of the behavior and ecology of free-ranging primates, and are also potentially adaptable to other mammalian taxa. PMID:20837036

Ratiometric near infrared luminescent thermometer based on lanthanide metal-organic frameworks

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

Yue, Dan; Zhang, Jun; Zhao, Dian

2016-09-15

A near infrared luminescent MOFs thermometer (Nd{sub 0.676}Yb{sub 0.324}BTC) was prepared via a simple solvothermal method using Ln{sup 3+} (Ln=Nd, Yb) ions and 1, 3, 5-benznenetricarboxylic acid (H{sub 3}BTC), and characterized by PXRD, TGA, ICP, and photoluminescence (PL) spectrum. These results indicate that the Nd{sub 0.676}Yb{sub 0.324}BTC displays high relative sensitivity and excellent repeatability in the physiological temperature range (288–323 K), and the maximum relative sensitivity is determined to be 1.187% K{sup −1} at 323 K. These NIR luminescent MOFs may have potential applications in physiological temperature sensing. - Graphical abstract: A near infrared luminescent MOFs thermometer (Nd{sub 0.054}Yb{sub 0.946}BTCmore » ) displays high relative sensitivity and excellent repeatability in the physiological temperature range (288–323 K). Display Omitted - Highlights: • A ratiometric near infrared luminescent MOFs thermometer (Nd{sub 0.676}Yb{sub 0.324}BTC) was prepared via a simple solvothermal method. • The maximum relative sensitivity of Nd{sub 0.676}Yb{sub 0.324}BTC is determined to be 1.187% K{sup −1} at 323 K. • Nd{sub 0.676}Yb{sub 0.324}BTC showed excellent repeatability in the physiological temperature range (288–323 K).« less

Water depth effects on impact loading, kinematic and physiological variables during water treadmill running.

PubMed

Macdermid, Paul W; Wharton, Josh; Schill, Carina; Fink, Philip W

2017-07-01

The purpose of this study was to compare impact loading, kinematic and physiological responses to three different immersion depths (mid-shin, mid-thigh, and xiphoid process) while running at the same speed on a water based treadmill. Participants (N=8) ran on a water treadmill at three depths for 3min. Tri-axial accelerometers were used to identify running dynamics plus measures associated with impact loading rates, while heart rate data were logged to indicate physiological demand. Participants had greater peak impact accelerations (p<0.01), greater impact loading rates (p<0.0001), greater stride frequency (p<0.05), shorter stride length (p<0.01), and greater rate of acceleration development at toe-off (p<0.0001) for the mid-shin and mid-thigh compared to running immersed to the xiphoid process. Physiological effort determined by heart rate was also significantly less (p<0.0001) when running immersed to the xiphoid process. Water immersed treadmill running above the waistline alters kinematics of gait, reduces variables associated with impact, while decreasing physiological demand compared to depths below the waistline. Copyright © 2017 Elsevier B.V. All rights reserved.

Expanding the range of free calcium regulation in biological solutions.

PubMed

Dweck, David; Reyes-Alfonso, Avelino; Potter, James D

2005-12-15

Many biological systems use ethylene glycol bis (beta-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA) to regulate the free calcium concentration ([Ca(2+)](free)) in the presence of physiological levels of free Mg(2+) ([Mg(2+)](free)). Frequently, it is necessary to work at [Ca(2+)](free) beyond EGTA's buffering capabilities. Therefore, we have developed methods to extend the buffering range by adding nitrilotriacetic acid (NTA) to solutions containing EGTA. This extension results from NTA having a lower K'(dCa) than EGTA. Such equilibria are solved by pCa Calculator, a computer program designed to aid in the study of Ca(2+)-dependent physiological processes while accounting for the effects of pH, temperature, and ionic strength. With multiple chelators and pH buffers from which to choose, pCa Calculator calculates the total concentration of each species required to achieve specified free concentrations of Ca(2+), ATP, and Mg(2+). The program is intuitive, user-friendly, and flexible enough to fix or vary the [Mg-ATP(2-)] and ionic strength. Moreover, it can account for increases in experimental volume from calcium addition. A comparative analysis is reported for testing solutions in the presence and absence of NTA by measuring the calcium binding affinity of fluorescent cardiac troponin C. These findings demonstrate that EGTA, when used in conjunction with NTA, improves and expands the regulation of free calcium in solution.

Paving a Path to Understanding Metabolic Responses to Iron Bioavailability: Global Proteomic Analysis of Crocosphaera watsonii

NASA Astrophysics Data System (ADS)

Gauglitz, J.; McIlvin, M. R.; Moran, D. M.; Waterbury, J. B.; Saito, M. A.

2016-02-01

Marine diazotrophic cyanobacteria provide a key source of new nitrogen into the oceans and are important contributors to primary production. The geographic distribution of these cyanobacteria is impacted by available iron and phosphorus as well as environmental conditions such as temperature, however available iron concentrations are thought to be particularly critical due to the high demand for iron in cellular processes. Iron bioavailability and microorganismal adaptations to low iron environments may thus play a key role in dictating community structure, however the mechanisms by which cyanobacteria acquire iron and regulate its uptake are not well defined. In this study, the unicellular diazotroph, Crocosphaera watsonii WH8501, was acclimated to a range of bioavailable iron concentrations (from 0.001nM to 8.13nM Fe') using trace metal clean culturing techniques and the proteomes were analyzed by LC/MS-MS. Physiological and proteomic data indicate three distinct phenotypic ranges: iron-replete, iron-limited, and iron-starved. Trends in photosynthetic, carbon fixation and iron storage proteins across the iron gradient indicate that the C. watsonii proteome responds directly to iron availability. Further analysis of relative protein expression, which describes the physiological state of the cell, will lead to insights into how C. watsonii is able to adapt to iron-limited conditions and the resulting biogeochemical implications will be discussed.

Does greater thermal plasticity facilitate range expansion of an invasive terrestrial anuran into higher latitudes?

PubMed

Winwood-Smith, Hugh S; Alton, Lesley A; Franklin, Craig E; White, Craig R

2015-01-01

Temperature has pervasive effects on physiological processes and is critical in setting species distribution limits. Since invading Australia, cane toads have spread rapidly across low latitudes, but slowly into higher latitudes. Low temperature is the likely factor limiting high-latitude advancement. Several previous attempts have been made to predict future cane toad distributions in Australia, but understanding the potential contribution of phenotypic plasticity and adaptation to future range expansion remains challenging. Previous research demonstrates the considerable thermal metabolic plasticity of the cane toad, but suggests limited thermal plasticity of locomotor performance. Additionally, the oxygen-limited thermal tolerance hypothesis predicts that reduced aerobic scope sets thermal limits for ectotherm performance. Metabolic plasticity, locomotor performance and aerobic scope are therefore predicted targets of natural selection as cane toads invade colder regions. We measured these traits at temperatures of 10, 15, 22.5 and 30°C in low- and high-latitude toads acclimated to 15 and 30°C, to test the hypothesis that cane toads have adapted to cooler temperatures. High-latitude toads show increased metabolic plasticity and higher resting metabolic rates at lower temperatures. Burst locomotor performance was worse for high-latitude toads. Other traits showed no regional differences. We conclude that increased metabolic plasticity may facilitate invasion into higher latitudes by maintaining critical physiological functions at lower temperatures.

Current knowledge on the sensitivity of the (68)Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours.

PubMed

Virgolini, Irene; Gabriel, Michael; Kroiss, Alexander; von Guggenberg, Elisabeth; Prommegger, Rupert; Warwitz, Boris; Nilica, Bernhard; Roig, Llanos Geraldo; Rodrigues, Margarida; Uprimny, Christian

2016-10-01

Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three (68)Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these (68)Ga-sstr-binding peptides in the imaging setting. On (68)Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake values (SUVmax) reported for the normal pancreas as well as for pancreatic neuroendocrine tumour (PNET) lesions may be related to several factors, including (a) differences in the peptide binding affinities as well as differences in sstr subtype expression of pancreatic α- and β-cells, and heterogeneity / density of tumour cells, (b) differences in scanner resolution, image reconstruction techniques and acquisition protocols, (c) mostly retrospective study designs, (d) mixed patient populations, or (e) interference with medications such as treatment with long-acting sst analogues. The major limitation in most of the studies lies in the lack of histopathological confirmation of abnormal findings. There is a significant overlap between the calculated SUVmax-values for physiological pancreas and PNET-lesions of the head/uncinate process that do not favour the use of quantitative parameters in the clinical setting. Anecdotal long-term follow-up studies have even indicated that increased uptake in the head/uncinate process still can turn out to be malignant over years of follow up. SUVmax-data for the pancreatic body and tail are limited. Therefore, any visible focal tracer uptake in the pancreas must be considered as suspicious for malignancy irrespective of quantitative parameters. In general, sstr-PET/CT has significant implications for the management of NET patients leading to a change in treatment decision in about one-third of patients. Therefore, follow-up with (68)Ga-sstr-PET/CT is mandatory in the clinical setting if uptake in the head/uncinate process is observed.

Use of Concept Mapping in an Undergraduate Introductory Exercise Physiology Course

ERIC Educational Resources Information Center

Henige, Kim

2012-01-01

Physiology is often considered a challenging course for students. It is up to teachers to structure courses and create learning opportunities that will increase the chance of student success. In an undergraduate exercise physiology course, concept maps are assigned to help students actively process and organize information into manageable and…

Leaf proteome characterization in the context of physiological and morphological changes in response to copper stress in sorghum

USDA-ARS?s Scientific Manuscript database

Copper (Cu) is an essential micronutrient required for the growth and development of plants. However, at elevated concentrations in soil, copper is very toxic to plant cells due to its inhibitory effects against many physiological and biochemical processes. In spite of its potential physiological an...

Evaluation of Physiology Lectures Conducted by Students: Comparison between Evaluation by Staff and Students

ERIC Educational Resources Information Center

Kommalage, Mahinda; Gunawardena, Sampath

2011-01-01

As a peer-assisted learning process, minilectures on physiology were conducted by students. During this process, students lecture to their colleagues in the presence of faculty staff members. These lectures were evaluated by faculty staff and students simultaneously. The aim of this study was to compare feedback from faculty members and students…

Individual Differences in Trajectories of Emotion Regulation Processes: The Effects of Maternal Depressive Symptomatology and Children's Physiological Regulation

ERIC Educational Resources Information Center

Blandon, Alysia Y.; Calkins, Susan D.; Keane, Susan P.; O'Brien, Marion

2008-01-01

Trajectories of emotion regulation processes were examined in a community sample of 269 children across the ages of 4 to 7 using hierarchical linear modeling. Maternal depressive symptomatology (Symptom Checklist-90) and children's physiological reactivity (respiratory sinus arrhythmia [RSA]) and vagal regulation ([delta]RSA) were explored as…

Emotion, Emotional Expression, and the Cognitive-Physiological Interaction: A Readout View.

ERIC Educational Resources Information Center

Buck, Ross

A basic tenet of this paper is that, from the time of the ancient Greeks, Western thought has distinguished between rational processes unique to humans and the processes governing animal behavior. A model of motivation, emotion, and the cognitive/physiological interaction that can be applied to both animals and humans is presented. The special…

Abnormal aldosterone physiology and cardiometabolic risk factors.

PubMed

Vaidya, Anand; Underwood, Patricia C; Hopkins, Paul N; Jeunemaitre, Xavier; Ferri, Claudio; Williams, Gordon H; Adler, Gail K

2013-04-01

Abnormal aldosterone physiology has been implicated in the pathogenesis of cardiometabolic diseases. Single aldosterone measurements capture only a limited range of aldosterone physiology. New methods of characterizing aldosterone physiology may provide a more comprehensive understanding of its relationship with cardiometabolic disease. We evaluated whether novel indices of aldosterone responses to dietary sodium modulation, the sodium-modulated aldosterone suppression-stimulation index (SASSI for serum and SAUSSI for urine), could predict cardiometabolic risk factors. We performed cross-sectional analyses on 539 subjects studied on liberal and restricted sodium diets with serum and urinary aldosterone measurements. SASSI and SAUSSI were calculated as the ratio of aldosterone on liberal (maximally suppressed aldosterone) to the aldosterone on restricted (stimulated aldosterone) diets and associated with risk factors using adjusted regression models. Cardiometabolic risk factors associated with either impaired suppression of aldosterone on liberal diet, or impaired stimulation on restricted diet, or both; in all of these individual cases, these risk factors associated with higher SASSI or SAUSSI. In the context of abnormalities that constitute the metabolic syndrome, there was a strong positive association between the number of metabolic syndrome components (0-4) and both SASSI and SAUSSI (P<0.0001) that was independent of known aldosterone secretagogues (angiotensin II, corticotropin, potassium). SASSI and SAUSSI exhibited a high sensitivity in detecting normal individuals with zero metabolic syndrome components (86% for SASSI and 83% for SAUSSI). Assessing the physiological range of aldosterone responses may provide greater insights into adrenal pathophysiology. Dysregulated aldosterone physiology may contribute to, or result from, early cardiometabolic abnormalities.

A novel hydrogel based piezoresistive pressure sensor platform for chemical sensing

NASA Astrophysics Data System (ADS)

Orthner, Michael P.

New hydrogel-based micropressure sensor arrays for use in the fields of chemical sensing, physiological monitoring, and medical diagnostics are developed and demonstrated. This sensor technology provides reliable, linear, and accurate measurements of hydrogel swelling pressures, a function of ambient chemical concentrations. For the first time, perforations were implemented into the pressure sensors piezoresistive diaphragms, used to simultaneously increase sensor sensitivity and permit diffusion of analytes into the hydrogel cavity. It was shown through analytical and numerical (finite element) methods that pore shape, location, and size can be used to modify the diaphragm mechanics and concentrate stress within the piezoresistors, thus improving electrical output (sensitivity). An optimized pore pattern was chosen based on these numerical calculations. Fabrication was performed using a 14-step semiconductor fabrication process implementing a combination of potassium hydroxide (KOH) and deep reactive ion etching (DRIE) to create perforations. The sensor arrays (2x2) measure approximately 3 x 5 mm2 and used to measure full scale pressures of 50, 25, and 5 kPa, respectively. These specifications were defined by the various swelling pressures of ionic strength, pH and glucose specific hydrogels that were targeted in this work. Initial characterization of the sensor arrays was performed using a custom built bulge testing apparatus that simultaneously measured deflection (optical profilometry), pressure, and electrical output. The new perforated diaphragm sensors were found to be fully functional with sensitivities ranging from 23 to 252 muV/V-kPa with full scale output (FSO) ranging from 5 to 80 mV. To demonstrate proof of concept, hydrogels sensitive to changes in ionic strength were synthesized using hydroxypropyl-methacrylate (HPMA), N,N-dimethylaminoethyl-methacrylate (DMA) and a tetra-ethyleneglycol-dimethacrylate (TEGDMA) crosslinker. This hydrogel quickly and reversibly swells when placed environments of physiological buffer solutions (PBS) with ionic strengths ranging from 0.025 to 0.15 M. Chemical testing showed sensors with perforated diaphragms have higher sensitivity than those with solid diaphragms, and sensitivities ranging from 53.3+/-6.5 to 271.47+/-27.53 mV/V-M, depending on diaphragm size. Additionally, recent experiments show sensors utilizing Ultra Violet (UV) polymerized glucose sensitive hydrogels respond reversibly to physiologically relevant glucose concentrations from 0 to 20 mM.

Physiological expression of pancreatic somatostatin receptors in 99mTc-HYNIC-TOC scintigraphy.

PubMed

de la Cueva, L; Lloro, P; Sangrós, M J; López Vélez, L; Navarro, P; Sarria, L; Álvarez, S; Abós, D

2017-07-01

To describe the frequency of head and/or pancreas uncinate process uptake of 99mTc-HYNIC-TOC, to study its nature, and analyze its diagnostic value. Retrospective evaluation of 47 consecutive 99mTc-HYNIC-TOC examinations was conducted. Head and/or pancreas uncinate process uptake was considered to be physiological in patients with normal CT at the same episode and in follow-up. It was analyzed if age or diabetes mellitus was justifying the existence or not of uptake. 32.5% patients showed uptake; 73% of them were mild. 84.6% patients with uptake have no pathology and 4% had neuroendocrine pancreatic disease at CT. Neither the age nor the diabetes mellitus established differences in patients without lesion. Near one-third of patients show physiological uptake by head and/or pancreas uncinate process at 99mTc-HYNIC-TOC scintigraphy. It seems that neither the diabetes nor the ages are factors that determine this physiological uptake.

Engineering cells for cell culture bioprocessing--physiological fundamentals.

PubMed

Seth, Gargi; Hossler, Patrick; Yee, Joon Chong; Hu, Wei-Shou

2006-01-01

In the past decade, we have witnessed a tremendous increase in the number of mammalian cell-derived therapeutic proteins with clinical applications. The success of making these life-saving biologics available to the public is partly due to engineering efforts to enhance process efficiency. To further improve productivity, much effort has been devoted to developing metabolically engineered producing cells, which possess characteristics favorable for large-scale bioprocessing. In this article we discuss the fundamental physiological basis for cell engineering. Different facets of cellular mechanisms, including metabolism, protein processing, and the balancing pathways of cell growth and apoptosis, contribute to the complex traits of favorable growth and production characteristics. We present our assessment of the current state of the art by surveying efforts that have already been undertaken in engineering cells for a more robust process. The concept of physiological homeostasis as a key determinant and its implications on cell engineering is emphasized. Integrating the physiological perspective with cell culture engineering will facilitate attainment of dream cells with superlative characteristics.

Influences of thermal environment on fish growth.

PubMed

Boltaña, Sebastián; Sanhueza, Nataly; Aguilar, Andrea; Gallardo-Escarate, Cristian; Arriagada, Gabriel; Valdes, Juan Antonio; Soto, Doris; Quiñones, Renato A

2017-09-01

Thermoregulation in ectothermic animals is influenced by the ability to effectively respond to thermal variations. While it is known that ectotherms are affected by thermal changes, it remains unknown whether physiological and/or metabolic traits are impacted by modifications to the thermal environment. Our research provides key evidence that fish ectotherms are highly influenced by thermal variability during development, which leads to important modifications at several metabolic levels (e.g., growth trajectories, microstructural alterations, muscle injuries, and molecular mechanisms). In Atlantic salmon ( Salmo salar ), a wide thermal range (Δ T 6.4°C) during development (posthatch larvae to juveniles) was associated with increases in key thermal performance measures for survival and growth trajectory. Other metabolic traits were also significantly influenced, such as size, muscle cellularity, and molecular growth regulators possibly affected by adaptive processes. In contrast, a restricted thermal range (Δ T 1.4°C) was detrimental to growth, survival, and cellular microstructure as muscle growth could not keep pace with increased metabolic demands. These findings provide a possible basic explanation for the effects of thermal environment during growth. In conclusion, our results highlight the key role of thermal range amplitude on survival and on interactions with major metabolism-regulating processes that have positive adaptive effects for organisms.

International collaboration on Russian spacecraft and the case for free flyer biosatellites

NASA Technical Reports Server (NTRS)

Grindeland, Richard E.; Ilyin, Eugene A.; Holley, Daniel C.; Skidmore, Michael G.

2005-01-01

Animal research has been critical to the initiation and progress of space exploration. Animals were the original explorers of "space" two centuries ago and have played a crucial role by demonstrating that the space environment, with precautions, is compatible with human survival. Studies of mammals have yielded much of our knowledge of space physiology. As spaceflights to other planets are anticipated, animal research will continue to be essential to further reveal space physiology and to enable the longer missions. Much of the physiology data collected from space was obtained from the Cosmos (Bion) spaceflights, a series of Russian (Soviet)-International collaborative flights, over a 22 year period, which employed unmanned, free flyer biosatellites. Begun as a Soviet-only program, after the second flight the Russians invited American and other foreign scientists to participate. This program filled the 10 year hiatus between the last US biosatellite and the first animal experiments on the shuttles. Of the 11 flights in the Cosmos program nine of them were international; the flights continued over the years regardless of political differences between the Soviet Union and the Western world. The science evolved from sharing tissues to joint international planning and development, and from rat postmortem tissue analysis to in vivo measurements of a host of monkey physiological parameters during flight. Many types of biological specimens were carried on the modified Vostok spacecraft, but only the mammalian studies are discussed herein. The types of studies done encompass the full range of physiology and have begun to answer "critical" questions of space physiology posed by various ad hoc committees. The studies have not only yielded a prodigious and significant body of data, they have also introduced some new perspectives in physiology. A number of the physiological insights gained are relevant to physiology on Earth. The Cosmos flights also added significantly to flight-related technology, some of which also has application on our planet. In summary, the Cosmos biosatellite flights were extremely productive and of low cost. The Bion vehicles are versatile in that they can be placed into a variety of orbits and altitudes, and can carry radiation sources or other hazardous material which cannot be carried on manned vehicles. With recent advances in sensor, robotic, and data processing technology, future free flyers will be even more productive, and will largely preclude the need to fly animal experiments on manned vehicles. Currently, mammalian researchers do not have access to space for an unknown time, seriously impeding the advancement and understanding of space physiology during long duration missions. Initiation of a new, international program of free flyer biosatellites is critical to our further understanding of space physiology, and essential to continued human exploration of space.

Alarmins and immunity.

PubMed

Yang, De; Han, Zhen; Oppenheim, Joost J

2017-11-01

More than a decade has passed since the conceptualization of the "alarmin" hypothesis. The alarmin family has been expanding in terms of both number and the concept. It has recently become clear that alarmins play important roles as initiators and participants in a diverse range of physiological and pathophysiological processes such as host defense, regulation of gene expression, cellular homeostasis, wound healing, inflammation, allergy, autoimmunity, and oncogenesis. Here, we provide a general view on the participation of alarmins in the induction of innate and adaptive immune responses, as well as their contribution to tumor immunity. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Putting Neutrophils in Motion | Center for Cancer Research

Cancer.gov

During chemotaxis, immune cells such as neutrophils orient themselves and move along a chemical gradient that is induced by chemicals called chemoattractants. Chemoattractants bind to specific G-protein linked receptors to put things in motion. The binding triggers the dissociation of the Gα-subunit from the Gβγ-subunit, which activate several downstream signaling cascades. This ultimately leads to the polarization of actin and myosin filament networks at the front and back of cells, respectively. The end result is directed cell migration, which is important in a wide range of physiological responses including wound healing and leukocyte trafficking, as well as in pathological processes such as metastasis.

A sole multi-analyte receptor responds with three distinct fluorescence signals: traffic signal like sensing of Al(3+), Zn(2+) and F(-).

PubMed

Datta, Barun Kumar; Thiyagarajan, Durairaj; Ramesh, Aiyagari; Das, Gopal

2015-08-07

A dialdehyde-based multi-analyte sensor renders distinctive emission spectra for Al(3+), Zn(2+) and F(-) ions. The ligand exhibited different types of interactions with these three different ions resulting in the enhancement of fluorescence intensity at three different wavelengths. All the sensing processes were studied in detail by absorption spectroscopy, emission spectroscopy and (1)H-NMR titration experiment. The ligand has the working ability in a wide pH range including the physiological pH. The ligand is non-toxic and amicable for sensing intracellular Al(3+) and Zn(2+) in live HeLa cells.

Ferritin for the Clinician

PubMed Central

Knovich, Mary Ann; Storey, Jonathan A.; Coffman, Lan G.; Torti, Suzy V.

2009-01-01

Ferritin, a major iron storage protein, is essential to iron homeostasis and is involved in a wide range of physiologic and pathologic processes. In clinical medicine, ferritin is predominantly utilized as a serum marker of total body iron stores. In cases of iron deficiency and overload, serum ferritin serves a critical role in both diagnosis and management. Elevated serum and tissue ferritin are linked to coronary artery disease, malignancy, and poor outcomes following stem cell transplantation. Ferritin is directly implicated in less common but potentially devastating human diseases including sideroblastic anemias, neurodegenerative disorders, and hemophagocytic syndrome. Additionally, recent research describes novel functions of ferritin independent of iron storage. PMID:18835072

Coronary microvascular dysfunction in diabetes mellitus

PubMed Central

Selthofer-Relatic, Kristina; Drenjancevic, Ines; Bacun, Tatjana; Bosnjak, Ivica; Kibel, Dijana; Gros, Mario

2017-01-01

The significance, mechanisms and consequences of coronary microvascular dysfunction associated with diabetes mellitus are topics into which we have insufficient insight at this time. It is widely recognized that endothelial dysfunction that is caused by diabetes in various vascular beds contributes to a wide range of complications and exerts unfavorable effects on microcirculatory regulation. The coronary microcirculation is precisely regulated through a number of interconnected physiological processes with the purpose of matching local blood flow to myocardial metabolic demands. Dysregulation of this network might contribute to varying degrees of pathological consequences. This review discusses the most important findings regarding coronary microvascular dysfunction in diabetes from pre-clinical and clinical perspectives. PMID:28643578

Probabilistic brains: knowns and unknowns

PubMed Central

Pouget, Alexandre; Beck, Jeffrey M; Ma, Wei Ji; Latham, Peter E

2015-01-01

There is strong behavioral and physiological evidence that the brain both represents probability distributions and performs probabilistic inference. Computational neuroscientists have started to shed light on how these probabilistic representations and computations might be implemented in neural circuits. One particularly appealing aspect of these theories is their generality: they can be used to model a wide range of tasks, from sensory processing to high-level cognition. To date, however, these theories have only been applied to very simple tasks. Here we discuss the challenges that will emerge as researchers start focusing their efforts on real-life computations, with a focus on probabilistic learning, structural learning and approximate inference. PMID:23955561

The interaction of psychological and physiological homeostatic drives and role of general control principles in the regulation of physiological systems, exercise and the fatigue process - The Integrative Governor theory.

PubMed

St Clair Gibson, A; Swart, J; Tucker, R

2018-02-01

Either central (brain) or peripheral (body physiological system) control mechanisms, or a combination of these, have been championed in the last few decades in the field of Exercise Sciences as how physiological activity and fatigue processes are regulated. In this review, we suggest that the concept of 'central' or 'peripheral' mechanisms are both artificial constructs that have 'straight-jacketed' research in the field, and rather that competition between psychological and physiological homeostatic drives is central to the regulation of both, and that governing principles, rather than distinct physical processes, underpin all physical system and exercise regulation. As part of the Integrative Governor theory we develop in this review, we suggest that both psychological and physiological drives and requirements are underpinned by homeostatic principles, and that regulation of the relative activity of each is by dynamic negative feedback activity, as the fundamental general operational controller. Because of this competitive, dynamic interplay, we propose that the activity in all systems will oscillate, that these oscillations create information, and comparison of this oscillatory information with either prior information, current activity, or activity templates create efferent responses that change the activity in the different systems in a similarly dynamic manner. Changes in a particular system are always the result of perturbations occurring outside the system itself, the behavioural causative 'history' of this external activity will be evident in the pattern of the oscillations, and awareness of change occurs as a result of unexpected rather than planned change in physiological activity or psychological state.

Genetic approaches in comparative and evolutionary physiology.

PubMed

Storz, Jay F; Bridgham, Jamie T; Kelly, Scott A; Garland, Theodore

2015-08-01

Whole animal physiological performance is highly polygenic and highly plastic, and the same is generally true for the many subordinate traits that underlie performance capacities. Quantitative genetics, therefore, provides an appropriate framework for the analysis of physiological phenotypes and can be used to infer the microevolutionary processes that have shaped patterns of trait variation within and among species. In cases where specific genes are known to contribute to variation in physiological traits, analyses of intraspecific polymorphism and interspecific divergence can reveal molecular mechanisms of functional evolution and can provide insights into the possible adaptive significance of observed sequence changes. In this review, we explain how the tools and theory of quantitative genetics, population genetics, and molecular evolution can inform our understanding of mechanism and process in physiological evolution. For example, lab-based studies of polygenic inheritance can be integrated with field-based studies of trait variation and survivorship to measure selection in the wild, thereby providing direct insights into the adaptive significance of physiological variation. Analyses of quantitative genetic variation in selection experiments can be used to probe interrelationships among traits and the genetic basis of physiological trade-offs and constraints. We review approaches for characterizing the genetic architecture of physiological traits, including linkage mapping and association mapping, and systems approaches for dissecting intermediary steps in the chain of causation between genotype and phenotype. We also discuss the promise and limitations of population genomic approaches for inferring adaptation at specific loci. We end by highlighting the role of organismal physiology in the functional synthesis of evolutionary biology. Copyright © 2015 the American Physiological Society.

Ontology of physics for biology: representing physical dependencies as a basis for biological processes

PubMed Central

2013-01-01

Background In prior work, we presented the Ontology of Physics for Biology (OPB) as a computational ontology for use in the annotation and representations of biophysical knowledge encoded in repositories of physics-based biosimulation models. We introduced OPB:Physical entity and OPB:Physical property classes that extend available spatiotemporal representations of physical entities and processes to explicitly represent the thermodynamics and dynamics of physiological processes. Our utilitarian, long-term aim is to develop computational tools for creating and querying formalized physiological knowledge for use by multiscale “physiome” projects such as the EU’s Virtual Physiological Human (VPH) and NIH’s Virtual Physiological Rat (VPR). Results Here we describe the OPB:Physical dependency taxonomy of classes that represent of the laws of classical physics that are the “rules” by which physical properties of physical entities change during occurrences of physical processes. For example, the fluid analog of Ohm’s law (as for electric currents) is used to describe how a blood flow rate depends on a blood pressure gradient. Hooke’s law (as in elastic deformations of springs) is used to describe how an increase in vascular volume increases blood pressure. We classify such dependencies according to the flow, transformation, and storage of thermodynamic energy that occurs during processes governed by the dependencies. Conclusions We have developed the OPB and annotation methods to represent the meaning—the biophysical semantics—of the mathematical statements of physiological analysis and the biophysical content of models and datasets. Here we describe and discuss our approach to an ontological representation of physical laws (as dependencies) and properties as encoded for the mathematical analysis of biophysical processes. PMID:24295137

Multiorgan insulin sensitivity in lean and obese subjects.

PubMed

Conte, Caterina; Fabbrini, Elisa; Kars, Marleen; Mittendorfer, Bettina; Patterson, Bruce W; Klein, Samuel

2012-06-01

To provide a comprehensive assessment of multiorgan insulin sensitivity in lean and obese subjects with normal glucose tolerance. The hyperinsulinemic-euglycemic clamp procedure with stable isotopically labeled tracer infusions was performed in 40 obese (BMI 36.2 ± 0.6 kg/m(2), mean ± SEM) and 26 lean (22.5 ± 0.3 kg/m(2)) subjects with normal glucose tolerance. Insulin was infused at different rates to achieve low, medium, and high physiological plasma concentrations. In obese subjects, palmitate and glucose R(a) in plasma decreased with increasing plasma insulin concentrations. The decrease in endogenous glucose R(a) was greater during low-, medium-, and high-dose insulin infusions (69 ± 2, 74 ± 2, and 90 ± 2%) than the suppression of palmitate R(a) (52 ± 4, 68 ± 1, and 79 ± 1%). Insulin-mediated increase in glucose disposal ranged from 24 ± 5% at low to 253 ± 19% at high physiological insulin concentrations. The suppression of palmitate R(a) and glucose R(a) were greater in lean than obese subjects during low-dose insulin infusion but were the same in both groups during high-dose insulin infusion, whereas stimulation of glucose R(d) was greater in lean than obese subjects across the entire physiological range of plasma insulin. Endogenous glucose production and adipose tissue lipolytic rate are both very sensitive to small increases in circulating insulin, whereas stimulation of muscle glucose uptake is minimal until high physiological plasma insulin concentrations are reached. Hyperinsulinemia within the normal physiological range can compensate for both liver and adipose tissue insulin resistance, but not skeletal muscle insulin resistance, in obese people who have normal glucose tolerance.

Baseline Physiologic and Psychosocial Characteristics of Transgender Youth Seeking Care for Gender Dysphoria

PubMed Central

Olson, Johanna; Schrager, Sheree M.; Belzer, Marvin; Simons, Lisa K.; Clark, Leslie F.

2016-01-01

Purpose The purpose of this study was to describe baseline characteristics of participants in a prospective observational study of transgender youth (aged 12–24 years) seeking care for gender dysphoria at a large, urban transgender youth clinic. Methods Eligible participants presented consecutively for care at between February 2011 and June 2013 and completed a computer-assisted survey at their initial study visit. Physiologic data were abstracted from medical charts. Data were analyzed by descriptive statistics, with limited comparisons between transmasculine and transfeminine participants. Results A total of 101 youth were evaluated for physiologic parameters, 96 completed surveys assessing psychosocial parameters. About half (50.5%) of the youth were assigned a male sex at birth. Baseline physiologic values were within normal ranges for assigned sex at birth. Youth recognized gender incongruence at a mean age of 8.3 years (standard deviation = 4.5), yet disclosed to their family much later (mean = 17.1; standard deviation = 4.2). Gender dysphoria was high among all participants. Thirty-five percent of the participants reported depression symptoms in the clinical range. More than half of the youth reported having thought about suicide at least once in their lifetime, and nearly a third had made at least one attempt. Conclusions Baseline physiologic parameters were within normal ranges for assigned sex at birth. Transgender youth are aware of the incongruence between their internal gender identity and their assigned sex at early ages. Prevalence of depression and suicidality demonstrates that youth may benefit from timely and appropriate intervention. Evaluation of these youth over time will help determine the impact of medical intervention and mental health therapy. PMID:26208863

A pseudo-three-dimensional model for quantification of oxygen diffusion from preglomerular arteries to renal tissue and renal venous blood.

PubMed

Lee, Chang-Joon; Ngo, Jennifer P; Kar, Saptarshi; Gardiner, Bruce S; Evans, Roger G; Smith, David W

2017-08-01

To assess the physiological significance of arterial-to-venous (AV) oxygen shunting, we generated a new pseudo-three-dimensional computational model of oxygen diffusion from intrarenal arteries to cortical tissue and veins. The model combines the 11 branching levels (known as "Strahler" orders) of the preglomerular renal vasculature in the rat, with an analysis of an extensive data set obtained using light microscopy to estimate oxygen mass transfer coefficients for each Strahler order. Furthermore, the AV shunting model is now set within a global oxygen transport model that includes transport from arteries, glomeruli, peritubular capillaries, and veins to tissue. While a number of lines of evidence suggest AV shunting is significant, most importantly, our AV oxygen shunting model predicts AV shunting is small under normal physiological conditions (~0.9% of total renal oxygen delivery; range 0.4-1.4%), but increases during renal ischemia, glomerular hyperfiltration (~2.1% of total renal oxygen delivery; range 0.84-3.36%), and some cardiovascular disease states (~3.0% of total renal oxygen delivery; range 1.2-4.8%). Under normal physiological conditions, blood Po 2 is predicted to fall by ~16 mmHg from the root of the renal artery to glomerular entry, with AV oxygen shunting contributing ~40% and oxygen diffusion from arteries to tissue contributing ~60% of this decline. Arterial Po 2 is predicted to fall most rapidly from Strahler order 4 , under normal physiological conditions. We conclude that AV oxygen shunting normally has only a small impact on renal oxygenation, but may exacerbate renal hypoxia during renal ischemia, hyperfiltration, and some cardiovascular disease states. Copyright © 2017 the American Physiological Society.

Baseline Physiologic and Psychosocial Characteristics of Transgender Youth Seeking Care for Gender Dysphoria.

PubMed

Olson, Johanna; Schrager, Sheree M; Belzer, Marvin; Simons, Lisa K; Clark, Leslie F

2015-10-01

The purpose of this study was to describe baseline characteristics of participants in a prospective observational study of transgender youth (aged 12-24 years) seeking care for gender dysphoria at a large, urban transgender youth clinic. Eligible participants presented consecutively for care at between February 2011 and June 2013 and completed a computer-assisted survey at their initial study visit. Physiologic data were abstracted from medical charts. Data were analyzed by descriptive statistics, with limited comparisons between transmasculine and transfeminine participants. A total of 101 youth were evaluated for physiologic parameters, 96 completed surveys assessing psychosocial parameters. About half (50.5%) of the youth were assigned a male sex at birth. Baseline physiologic values were within normal ranges for assigned sex at birth. Youth recognized gender incongruence at a mean age of 8.3 years (standard deviation = 4.5), yet disclosed to their family much later (mean = 17.1; standard deviation = 4.2). Gender dysphoria was high among all participants. Thirty-five percent of the participants reported depression symptoms in the clinical range. More than half of the youth reported having thought about suicide at least once in their lifetime, and nearly a third had made at least one attempt. Baseline physiologic parameters were within normal ranges for assigned sex at birth. Transgender youth are aware of the incongruence between their internal gender identity and their assigned sex at early ages. Prevalence of depression and suicidality demonstrates that youth may benefit from timely and appropriate intervention. Evaluation of these youth over time will help determine the impact of medical intervention and mental health therapy. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

A feasiblity study of an ultrasonic test phantom arm

NASA Astrophysics Data System (ADS)

Schneider, Philip

This thesis is a feasibility study for the creation of a test phantom that replicates the physiological features, from an acoustic and mechanical standpoint, of that of a human arm. Physiological feature set includes; Heart, Arteries, Veins, Bone, Muscle, Fat, Skin, and Dermotographic Features (finger prints). Mechanical Aspects include, vascular compression and distention, elasticity of tissue layers, mechanics of human heart. The end goal of which to have a working understanding of each component in order to create a controllable, real time, physiologically accurate, test phantom for a wide range of ultrasonic based applications. These applications can range from devices like wearable technologies to medical training, to biometric "Liveness" detection methods. The proposed phantom would allow for a number of natural bodily functions to be measured including but not limited to vascular mapping, blood pressure, heart rate, subdermal imaging, and general ultrasonic imaging.

Real-time processing of EMG signals for bionic arm purposes

NASA Astrophysics Data System (ADS)

Olid Dominguez, Ferran; Wawrzyniak, Zbigniew M.

2016-09-01

This paper is connected with the problem of prostheses, that have always been a necessity for the human being. Bio-physiological signals from muscles, electromyographic signals have been collected, analyzed and processed in order to implement a real-time algorithm which is capable of differentiation of two different states of a bionic hand: open and closed. An algorithm for real-time electromyographic signal processing with almost no false positives is presented and it is explained that in bio-physiological experiments proper signal processing is of great importance.

Body Composition and Physiological Responses of Masters Female Swimmers 20 to 70 Years of Age.

ERIC Educational Resources Information Center

Vaccaro, Paul; And Others

1984-01-01

Female masters swimmers ranging in age from 20 to 69 were chosen for a study of their body composition and physiological responses at rest and during exercise. Two training groups were formed that differed on the basis of frequency, duration, and intensity of swimming workouts. Results are discussed. (Author/DF)

Using time-series intervention analysis to model cow heart rate affected by programmed audio and environmental/physiological cues

USDA-ARS?s Scientific Manuscript database

This research is the first use of the Box-Jenkins time-series models to describe changes in heart rate (HR) of free-ranging crossbred cows (Bos taurus) receiving both programmed audio cues from directional virtual fencing (DVFTM) devices and non-programmed environmental/physiological cues. The DVFT...

Stream computing for biomedical signal processing: A QRS complex detection case-study.

PubMed

Murphy, B M; O'Driscoll, C; Boylan, G B; Lightbody, G; Marnane, W P

2015-01-01

Recent developments in "Big Data" have brought significant gains in the ability to process large amounts of data on commodity server hardware. Stream computing is a relatively new paradigm in this area, addressing the need to process data in real time with very low latency. While this approach has been developed for dealing with large scale data from the world of business, security and finance, there is a natural overlap with clinical needs for physiological signal processing. In this work we present a case study of streams processing applied to a typical physiological signal processing problem: QRS detection from ECG data.

LC3- and p62-based biochemical methods for the analysis of autophagy progression in mammalian cells.

PubMed

Jiang, Peidu; Mizushima, Noboru

2015-03-01

Autophagy is an intracellular degradation system that delivers cytoplasmic materials to the lysosome or vacuole. This system plays a crucial role in various physiological and pathological processes in living organisms ranging from yeast to mammals. Thus, an accurate and reliable measure of autophagic activity is necessary. However, autophagy involves dynamic and complicated processes that make it difficult to analyze. The term "autophagic flux" is used to denote overall autophagic degradation (i.e., delivery of autophagic cargo to the lysosome) rather than autophagosome formation. Immunoblot analysis of LC3 and p62/SQSTM1, among other proteins, has been widely used to monitor autophagic flux. Here, we describe basic protocols to measure the levels of endogenous LC3 and p62 by immunoblotting in cultured mammalian cells. Copyright © 2014 Elsevier Inc. All rights reserved.

Response of salt marsh and mangrove wetlands to changes in atmospheric CO2, climate, and sea-level

USGS Publications Warehouse

Mckee, Karen L.; Rogers, Kerrylee; Saintilan, Neil; Middleton, Beth A.

2012-01-01

Coastal salt marsh and mangrove ecosystems are particularly vulnerable to changes in atmospheric CO2 concentrations and associated climate and climate-induced changes. We provide a review of the literature detailing theoretical predictions and observed responses of coastal wetlands to a range of climate change stressors, including CO2, temperature, rainfall, and sea-level rise. This review incorporates a discussion of key processes controlling responses in different settings and thresholds of resilience derived from experimental and observational studies. We specifically consider the potential and observed effects on salt marsh and mangrove vegetation of changes in (1) elevated [CO2] on physiology, growth, and distribution; (2) temperature on distribution and diversity; (3) rainfall and salinity regimes on growth and competitive interactions; and (4) sea level on geomorphological, hydrological, and biological processes.

Students' Conceptions of Underlying Principles in Medical Physiology: An Interview Study of Medical Students' Understanding in a PBL Curriculum

ERIC Educational Resources Information Center

Fyrenius, Anna; Silen, Charlotte; Wirell, Staffan

2007-01-01

Medical physiology is known to be a complex area where students develop significant errors in conceptual understanding. Students' knowledge is often bound to situational descriptions rather than underlying principles. This study explores how medical students discern and process underlying principles in physiology. Indepth interviews, where…

Physiological Factors in Adult Learning and Instruction. Research to Practice Series.

ERIC Educational Resources Information Center

Verner, Coolie; Davison, Catherine V.

The physiological condition of the adult learner as related to his learning capability is discussed. The design of the instructional process, the selection of learning tasks, the rate at which instruction occurs, and the nature of the instructional setting may all be modified by the instructor to accomodate the variable physiological conditions of…

Research on human physiological parameters intelligent clothing based on distributed Fiber Bragg Grating

NASA Astrophysics Data System (ADS)

Miao, Changyun; Shi, Boya; Li, Hongqiang

2008-12-01

A human physiological parameters intelligent clothing is researched with FBG sensor technology. In this paper, the principles and methods of measuring human physiological parameters including body temperature and heart rate in intelligent clothing with distributed FBG are studied, the mathematical models of human physiological parameters measurement are built; the processing method of body temperature and heart rate detection signals is presented; human physiological parameters detection module is designed, the interference signals are filtered out, and the measurement accuracy is improved; the integration of the intelligent clothing is given. The intelligent clothing can implement real-time measurement, processing, storage and output of body temperature and heart rate. It has accurate measurement, portability, low cost, real-time monitoring, and other advantages. The intelligent clothing can realize the non-contact monitoring between doctors and patients, timely find the diseases such as cancer and infectious diseases, and make patients get timely treatment. It has great significance and value for ensuring the health of the elders and the children with language dysfunction.

Structure and Kinetic Analysis of H2S Production by Human Mercaptopyruvate Sulfurtransferase*

PubMed Central

Yadav, Pramod Kumar; Yamada, Kazuhiro; Chiku, Taurai; Koutmos, Markos; Banerjee, Ruma

2013-01-01

Mercaptopyruvate sulfurtransferase (MST) is a source of endogenous H2S, a gaseous signaling molecule implicated in a wide range of physiological processes. The contribution of MST versus the other two H2S generators, cystathionine β-synthase and γ-cystathionase, has been difficult to evaluate because many studies on MST have been conducted at high pH and have used varied reaction conditions. In this study, we have expressed, purified, and crystallized human MST in the presence of the substrate 3-mercaptopyruvate (3-MP). The kinetics of H2S production by MST from 3-MP was studied at pH 7.4 in the presence of various physiological persulfide acceptors: cysteine, dihydrolipoic acid, glutathione, homocysteine, and thioredoxin, and in the presence of cyanide. The crystal structure of MST reveals a mixture of the product complex containing pyruvate and an active site cysteine persulfide (Cys248-SSH) and a nonproductive intermediate in which 3-MP is covalently linked via a disulfide bond to an active site cysteine. The crystal structure analysis allows us to propose a detailed mechanism for MST in which an Asp-His-Ser catalytic triad is positioned to activate the nucleophilic cysteine residue and participate in general acid-base chemistry, whereas our kinetic analysis indicates that thioredoxin is likely to be the major physiological persulfide acceptor for MST. PMID:23698001

Oxygen diffusion and consumption in extracellular matrix gels: implications for designing three-dimensional cultures.

PubMed

Colom, Adai; Galgoczy, Roland; Almendros, Isaac; Xaubet, Antonio; Farré, Ramon; Alcaraz, Jordi

2014-08-01

Three-dimensional (3D) cultures are increasingly used as tissue surrogates to study many physiopathological processes. However, to what extent current 3D culture protocols provide physiologic oxygen tension conditions remains ill defined. To address this limitation, oxygen tension was measured in a panel of acellular or cellularized extracellular matrix (ECM) gels with A549 cells, and analyzed in terms of oxygen diffusion and consumption. Gels included reconstituted basement membrane, fibrin and collagen. Oxygen diffusivity in acellular gels was up to 40% smaller than that of water, and the lower values were observed in the denser gels. In 3D cultures, physiologic oxygen tension was achieved after 2 days in dense (≥3 mg/mL) but not sparse gels, revealing that the latter gels are not suitable tissue surrogates in terms of oxygen distribution. In dense gels, we observed a dominant effect of ECM composition over density in oxygen consumption. All diffusion and consumption data were used in a simple model to estimate ranges for gel thickness, seeding density and time-window that may support physiologic oxygen tension. Thus, we identified critical variables for oxygen tension in ECM gels, and introduced a model to assess initial values of these variables, which may short-cut the optimization step of 3D culture studies. © 2013 Wiley Periodicals, Inc.

An Advanced Bio-Inspired PhotoPlethysmoGraphy (PPG) and ECG Pattern Recognition System for Medical Assessment

PubMed Central

Rundo, Francesco; Ortis, Alessandro

2018-01-01

Physiological signals are widely used to perform medical assessment for monitoring an extensive range of pathologies, usually related to cardio-vascular diseases. Among these, both PhotoPlethysmoGraphy (PPG) and Electrocardiography (ECG) signals are those more employed. PPG signals are an emerging non-invasive measurement technique used to study blood volume pulsations through the detection and analysis of the back-scattered optical radiation coming from the skin. ECG is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin. In the present paper we propose a physiological ECG/PPG “combo” pipeline using an innovative bio-inspired nonlinear system based on a reaction-diffusion mathematical model, implemented by means of the Cellular Neural Network (CNN) methodology, to filter PPG signal by assigning a recognition score to the waveforms in the time series. The resulting “clean” PPG signal exempts from distortion and artifacts is used to validate for diagnostic purpose an EGC signal simultaneously detected for a same patient. The multisite combo PPG-ECG system proposed in this work overpasses the limitations of the state of the art in this field providing a reliable system for assessing the above-mentioned physiological parameters and their monitoring over time for robust medical assessment. The proposed system has been validated and the results confirmed the robustness of the proposed approach. PMID:29385774

An Advanced Bio-Inspired PhotoPlethysmoGraphy (PPG) and ECG Pattern Recognition System for Medical Assessment.

PubMed

Rundo, Francesco; Conoci, Sabrina; Ortis, Alessandro; Battiato, Sebastiano

2018-01-30

Physiological signals are widely used to perform medical assessment for monitoring an extensive range of pathologies, usually related to cardio-vascular diseases. Among these, both PhotoPlethysmoGraphy (PPG) and Electrocardiography (ECG) signals are those more employed. PPG signals are an emerging non-invasive measurement technique used to study blood volume pulsations through the detection and analysis of the back-scattered optical radiation coming from the skin. ECG is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin. In the present paper we propose a physiological ECG/PPG "combo" pipeline using an innovative bio-inspired nonlinear system based on a reaction-diffusion mathematical model, implemented by means of the Cellular Neural Network (CNN) methodology, to filter PPG signal by assigning a recognition score to the waveforms in the time series. The resulting "clean" PPG signal exempts from distortion and artifacts is used to validate for diagnostic purpose an EGC signal simultaneously detected for a same patient. The multisite combo PPG-ECG system proposed in this work overpasses the limitations of the state of the art in this field providing a reliable system for assessing the above-mentioned physiological parameters and their monitoring over time for robust medical assessment. The proposed system has been validated and the results confirmed the robustness of the proposed approach.

A Review of Physiological and Psychological Changes in Aging and Their Implications for Teachers of Adults.

ERIC Educational Resources Information Center

Hand, Samuel E.

This review of literature on the aging process points out primary physiological and psychological changes in maturing adults which have implications for teachers of adults. Visual acuity and hearing decline during adult years and there is a general slowing down process of most bodily activities. Teachers should be aware of the need for good…

Physiological Aspects of Aging. Module A-5. Block A. Basic Knowledge of the Aging Process.

ERIC Educational Resources Information Center

Harvey, Dexter; Cap, Orest

This instructional module on physiological aspects of aging is one in a block of 10 modules designed to provide the human services worker who works with older adults with basic information regarding the aging process. An introduction provides an overview of the module content. A listing of general objectives follows. Nine sections present…

Social Support and Heart Failure: Differing Effects by Race

DTIC Science & Technology

2015-05-11

responses. These compensatory physiologic responses include increased sympathetic nervous system activity, inflammation, and constriction of blood vessels... physiological differences between African Americans and Caucasians. For instance the process by which sodium is processed in the body may vary between...associated cardiovascular and inflammatory diseases (76). One important hormone at work in the cardiovascular system is aldosterone and it may have a

Shape and shear guide sperm cells spiraling upstream

NASA Astrophysics Data System (ADS)

Kantsler, Vasily; Dunkel, Jorn; Goldstein, Raymond E.

2014-11-01

A major puzzle in biology is how mammalian sperm determine and maintain the correct swimming direction during the various phases of the sexual reproduction process. Currently debated mechanisms for sperm long range travel vary from peristaltic pumping to temperature sensing (thermotaxis) and direct response to fluid flow (rheotaxis), but little is known quantitatively about their relative importance. Here, we report the first quantitative experimental study of mammalian sperm rheotaxis. Using microfluidic devices, we investigate systematically the swimming behavior of human and bull sperm over a wide range of physiologically relevant shear rates and viscosities. Our measurements show that the interplay of fluid shear, steric surface-interactions and chirality of the flagellar beat leads to a stable upstream spiraling motion of sperm cells, thus providing a generic and robust rectification mechanism to support mammalian fertilization. To rationalize these findings, we identify a minimal mathematical model that is capable of describing quantitatively the experimental observations.

Evaluation of the biological effects of police radar RAMER 7F

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

Rotkovska, D.; Kautska, J.; Bartonickova, A.

1993-06-01

This paper presents results of experiments on the effects of electromagnetic radiation in the millimeter range (frequency 34.0 [+-] 0.1 GHz, power density 20 [mu]W/cm[sup 2]) emitted by a police radar device. Considering the physical properties of the radiation in millimeter range (skin effects), the experiments were carried out on hairless mice. The main physiological parameters tested were body mass, body temperature, peripheral blood, and mass and cellularity of several important organs. Critical organs, the skin, and cornea were examined by electron microscopy. Differentiation ability of hematopoietic cells, progenitors of granulocytes and macrophages, and DNA synthesis in the cornea weremore » compared in irradiated and nonirradiated animals. None of the parameters tested was affected to an extent that would indicate the start of a pathological process or the risk of damage to genetic material.« less

Four-point bending protocols to study the effects of dynamic strain in osteoblastic cells in vitro.

PubMed

Galea, Gabriel L; Price, Joanna S

2015-01-01

Strain engendered within bone tissue by mechanical loading of the skeleton is a major influence on the processes of bone modeling and remodeling and so a critical determinant of bone mass and architecture. The cells best placed to respond to strain in bone tissue are the resident osteocytes and osteoblasts. To address the mechanisms of strain-related responses in osteoblast-like cells, our group uses both in vivo and in vitro approaches, including a system of four-point bending of the substrate on which cells are cultured. A range of cell lines can be studied using this system but we routinely compare their responses to those in primary cultures of osteoblast-like cells derived from explants of mouse long bones. These cells show a range of well-characterized responses to physiological levels of strain, including increased proliferation, which in vivo is a feature of the osteogenic response.

Personal health technologies, micropolitics and resistance: A new materialist analysis.

PubMed

Fox, Nick J

2017-03-01

Personal health technologies are near-body devices or applications designed for use by a single individual, principally outside healthcare facilities. They enable users to monitor physiological processes or body activity, are frequently communication-enabled and sometimes also intervene therapeutically. This article explores a range of personal health technologies, from blood pressure or blood glucose monitors purchased in pharmacies and fitness monitors such as Fitbit and Nike+ Fuelband to drug pumps and implantable medical devices. It applies a new materialist analysis, first reverse engineering a range of personal health technologies to explore their micropolitics and then forward engineering personal health technologies to meet, variously, public health, corporate, patient and resisting-citizen agendas. This article concludes with a critical discussion of personal health technologies and the possibilities of designing devices and apps that might foster subversive micropolitics and encourage collective and resisting 'citizen health'.

Psychosocial versus physiological stress – meta-analyses on deactivations and activations of the neural correlates of stress reactions

PubMed Central

Kogler, Lydia; Mueller, Veronika I.; Chang, Amy; Eickhoff, Simon B.; Fox, Peter T.; Gur, Ruben C.; Derntl, Birgit

2015-01-01

Stress is present in everyday life in various forms and situations. Two stressors frequently investigated are physiological and psychosocial stress. Besides similar subjective and hormonal responses, it has been suggested that they also share common neural substrates. The current study used activation-likelihood-estimation meta-analysis to test this assumption by integrating results of previous neuroimaging studies on stress processing. Reported results are cluster-level FWE corrected. The inferior frontal gyrus (IFG) and the anterior insula (AI) were the only regions that demonstrated overlapping activation for both stressors. Analysis of physiological stress showed consistent activation of cognitive and affective components of pain processing such as the insula, striatum, or the middle cingulate cortex. Contrarily, analysis across psychosocial stress revealed consistent activation of the right superior temporal gyrus and deactivation of the striatum. Notably, parts of the striatum appeared to be functionally specified: the dorsal striatum was activated in physiological stress, whereas the ventral striatum was deactivated in psychosocial stress. Additional functional connectivity and decoding analyses further characterized this functional heterogeneity and revealed higher associations of the dorsal striatum with motor regions and of the ventral striatum with reward processing. Based on our meta-analytic approach, activation of the IFG and the AI seems to indicate a global neural stress reaction. While physiological stress activates a motoric fight-or-flight reaction, during psychosocial stress attention is shifted towards emotion regulation and goal-directed behavior, and reward processing is reduced. Our results show the significance of differentiating physiological and psychosocial stress in neural engagement. Furthermore, the assessment of deactivations in addition to activations in stress research is highly recommended. PMID:26123376

Measuring dynamic kidney function in an undergraduate physiology laboratory.

PubMed

Medler, Scott; Harrington, Frederick

2013-12-01

Most undergraduate physiology laboratories are very limited in how they treat renal physiology. It is common to find teaching laboratories equipped with the capability for high-resolution digital recordings of physiological functions (muscle twitches, ECG, action potentials, respiratory responses, etc.), but most urinary laboratories still rely on a "dipstick" approach of urinalysis. Although this technique can provide some basic insights into the functioning of the kidneys, it overlooks the dynamic processes of filtration, reabsorption, and secretion. In the present article, we provide a straightforward approach of using renal clearance measurements to estimate glomerular filtration rate, fractional water reabsorption, glucose clearance, and other physiologically relevant parameters. The estimated values from our measurements in laboratory are in close agreement with those anticipated based on textbook parameters. For example, we found glomerular filtration rate to average 124 ± 45 ml/min, serum creatinine to be 1.23 ± 0.4 mg/dl, and fractional water reabsorption to be ∼96.8%. Furthermore, analyses for the class data revealed significant correlations between parameters like fractional water reabsorption and urine concentration, providing opportunities to discuss urine concentrating mechanisms and other physiological processes. The procedures outlined here are general enough that most undergraduate physiology laboratory courses should be able to implement them without difficulty.

Visualization and classification of physiological failure modes in ensemble hemorrhage simulation

NASA Astrophysics Data System (ADS)

Zhang, Song; Pruett, William Andrew; Hester, Robert

2015-01-01

In an emergency situation such as hemorrhage, doctors need to predict which patients need immediate treatment and care. This task is difficult because of the diverse response to hemorrhage in human population. Ensemble physiological simulations provide a means to sample a diverse range of subjects and may have a better chance of containing the correct solution. However, to reveal the patterns and trends from the ensemble simulation is a challenging task. We have developed a visualization framework for ensemble physiological simulations. The visualization helps users identify trends among ensemble members, classify ensemble member into subpopulations for analysis, and provide prediction to future events by matching a new patient's data to existing ensembles. We demonstrated the effectiveness of the visualization on simulated physiological data. The lessons learned here can be applied to clinically-collected physiological data in the future.

Applying standardized uptake values in gallium-67-citrate single-photon emission computed tomography/computed tomography studies and their correlation with blood test results in representative organs.

PubMed

Toriihara, Akira; Daisaki, Hiromitsu; Yamaguchi, Akihiro; Yoshida, Katsuya; Isogai, Jun; Tateishi, Ukihide

2018-05-21

Recently, semiquantitative analysis using standardized uptake value (SUV) has been introduced in bone single-photon emission computed tomography/computed tomography (SPECT/CT). Our purposes were to apply SUV-based semiquantitative analytic method for gallium-67 (Ga)-citrate SPECT/CT and to evaluate correlation between SUV of physiological uptake and blood test results in representative organs. The accuracy of semiquantitative method was validated using an National Electrical Manufacturers Association body phantom study (radioactivity ratio of sphere : background=4 : 1). Thereafter, 59 patients (34 male and 25 female; mean age, 66.9 years) who had undergone Ga-citrate SPECT/CT were retrospectively enrolled in the study. A mean SUV of physiological uptake was calculated for the following organs: the lungs, right atrium, liver, kidneys, spleen, gluteal muscles, and bone marrow. The correlation between physiological uptakes and blood test results was evaluated using Pearson's correlation coefficient. The phantom study revealed only 1% error between theoretical and actual SUVs in the background, suggesting the sufficient accuracy of scatter and attenuation corrections. However, a partial volume effect could not be overlooked, particularly in small spheres with a diameter of less than 28 mm. The highest mean SUV was observed in the liver (range: 0.44-4.64), followed by bone marrow (range: 0.33-3.60), spleen (range: 0.52-2.12), and kidneys (range: 0.42-1.45). There was no significant correlation between hepatic uptake and liver function, renal uptake and renal function, or bone marrow uptake and blood cell count (P>0.05). The physiological uptake in Ga-citrate SPECT/CT can be represented as SUVs, which are not significantly correlated with corresponding blood test results.

A High Performance Pulsatile Pump for Aortic Flow Experiments in 3-Dimensional Models.

PubMed

Chaudhury, Rafeed A; Atlasman, Victor; Pathangey, Girish; Pracht, Nicholas; Adrian, Ronald J; Frakes, David H

2016-06-01

Aortic pathologies such as coarctation, dissection, and aneurysm represent a particularly emergent class of cardiovascular diseases. Computational simulations of aortic flows are growing increasingly important as tools for gaining understanding of these pathologies, as well as for planning their surgical repair. In vitro experiments are required to validate the simulations against real world data, and the experiments require a pulsatile flow pump system that can provide physiologic flow conditions characteristic of the aorta. We designed a newly capable piston-based pulsatile flow pump system that can generate high volume flow rates (850 mL/s), replicate physiologic waveforms, and pump high viscosity fluids against large impedances. The system is also compatible with a broad range of fluid types, and is operable in magnetic resonance imaging environments. Performance of the system was validated using image processing-based analysis of piston motion as well as particle image velocimetry. The new system represents a more capable pumping solution for aortic flow experiments than other available designs, and can be manufactured at a relatively low cost.

Relationship between physiological measurements (SFG -scope for growth-) and the functionality of the digestive gland in Mytilus galloprovincialis.

PubMed

Albentosa, Marina; Sánchez-Hernández, Miriam; Campillo, Juan Antonio; Moyano, Francisco Javier

2012-11-01

The present study was aimed to establish the relationship between the functionality of the digestive gland and physiological rates including SFG (scope for growth) in wild mussels, Mytilus galloprovincilis. The experimental set-up consisted in the evaluation of changes in the morphology of the gland, as well as in the activity of some key digestive enzymes (amylase, laminarinase, cellulase and protease) within a broad range of SFG obtained through manipulation of food ration. The higher SFG values were correlated to an increase in both the size of the digestive gland and the activities of enzymes when expressed in relation to individual. In contrast, no clear relations were observed when the activity of enzymes was expressed in relation to soluble protein, with the exception to amylase. The higher protease activities measured in mussels showing lower SFG may reflect an initial stage of catabolic processes intended to compensate the energy deficit produced by food restriction. The potential use of parameters measured in digestive glands in studies of marine pollution was discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

Molecular cell biology and physiology of solute transport

PubMed Central

Caplan, Michael J.; Seo-Mayer, Patricia; Zhang, Li

2010-01-01

Purpose of review An enormous body of research has been focused on exploring the mechanisms through which epithelial cells establish their characteristic polarity. It is clear that under normal circumstances cell–cell contacts mediated by the calcium-dependent adhesion proteins of the intercellular adhesion junctions are required to initiate complete polarization. Furthermore, formation of the tight, or occluding, junctions that limit paracellular permeability has long been thought to help to establish polarity by preventing the diffusion of membrane proteins between the two plasmalemmal domains. This review will discuss several selected kinases and protein complexes and highlight their relevance to transporting epithelial cell polarization. Recent findings Recent work has shed new light on the roles of junctional complexes in establishing and maintaining epithelial cell polarity. In addition, work from several laboratories, suggests that the formation of these junctions is tied to processes that regulate cellular energy metabolism. Summary Junctional complexes and energy sensing kinases constitute a novel class of machinery whose capacity to generate and modulate epithelial cell polarity is likely to have wide ranging and important physiological ramifications. PMID:18695392

Should modulation of p50 be a therapeutic target in the critically ill?

PubMed

Srinivasan, Amudan J; Morkane, Clare; Martin, Daniel S; Welsby, Ian J

2017-05-01

A defining feature of human hemoglobin is its oxygen binding affinity, quantified by the partial pressure of oxygen at which hemoglobin is 50% saturated (p50), and the variability of this parameter over a range of physiological and environmental states. Modulation of this property of hemoglobin can directly affect the degree of peripheral oxygen offloading and tissue oxygenation. Areas covered: This review summarizes the role of hemoglobin oxygen affinity in normal and abnormal physiology and discusses the current state of the literature regarding artificial modulation of p50. Hypoxic tumors, sickle cell disease, heart failure, and transfusion medicine are discussed in the context of recent advances in hemoglobin oxygen affinity manipulation. Expert commentary: Of particular clinical interest is the possibility of maintaining adequate end-organ oxygen availability in patients with anemia or compromised cardiac function via an increase in systemic p50. This increase in systemic p50 can be achieved with small molecule drugs or a packed red blood cell unit processing variant called rejuvenation, and human trials are needed to better understand the potential clinical benefits to modulating p50.

Structural plasticity and dynamic selectivity of acid-sensing ion channel-spider toxin complexes

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

Baconguis, Isabelle; Gouaux, Eric

2012-07-29

Acid-sensing ion channels (ASICs) are voltage-independent, amiloride-sensitive channels involved in diverse physiological processes ranging from nociception to taste. Despite the importance of ASICs in physiology, we know little about the mechanism of channel activation. Here we show that psalmotoxin activates non-selective and Na +-selective currents in chicken ASIC1a at pH7.25 and 5.5, respectively. Crystal structures of ASIC1a–psalmotoxin complexes map the toxin binding site to the extracellular domain and show how toxin binding triggers an expansion of the extracellular vestibule and stabilization of the open channel pore. At pH7.25 the pore is approximately 10Å in diameter, whereas at pH5.5 the poremore » is largely hydrophobic and elliptical in cross-section with dimensions of approximately 5 by 7Å, consistent with a barrier mechanism for ion selectivity. These studies define mechanisms for activation of ASICs, illuminate the basis for dynamic ion selectivity and provide the blueprints for new therapeutic agents.« less

Glycomics: revealing the dynamic ecology and evolution of sugar molecules.

PubMed

Springer, Stevan A; Gagneux, Pascal

2016-03-01

Sugars are the most functionally and structurally diverse molecules in the biological world. Glycan structures range from tiny single monosaccharide units to giant chains thousands of units long. Some glycans are branched, their monosaccharides linked together in many different combinations and orientations. Some exist as solitary molecules; others are conjugated to proteins and lipids and alter their collective functional properties. In addition to structural and storage roles, glycan molecules participate in and actively regulate physiological and developmental processes. Glycans also mediate cellular interactions within and between individuals. Their roles in ecology and evolution are pivotal, but not well studied because glycan biochemistry requires different methods than standard molecular biology practice. The properties of glycans are in some ways convenient, and in others challenging. Glycans vary on organismal timescales, and in direct response to physiological and ecological conditions. Their mature structures are physical records of both genetic and environmental influences during maturation. We describe the scope of natural glycan variation and discuss how studying glycans will allow researchers to further integrate the fields of ecology and evolution. Copyright © 2015 Elsevier B.V. All rights reserved.

Mechanisms of Metal Resistance and Homeostasis in Haloarchaea

PubMed Central

Srivastava, Pallavee; Kowshik, Meenal

2013-01-01

Haloarchaea are the predominant microflora of hypersaline econiches such as solar salterns, soda lakes, and estuaries where the salinity ranges from 35 to 400 ppt. Econiches like estuaries and solar crystallizer ponds may contain high concentrations of metals since they serve as ecological sinks for metal pollution and also as effective traps for river borne metals. The availability of metals in these econiches is determined by the type of metal complexes formed and the solubility of the metal species at such high salinity. Haloarchaea have developed specialized mechanisms for the uptake of metals required for various key physiological processes and are not readily available at high salinity, beside evolving resistance mechanisms for metals with high solubility. The present paper seeks to give an overview of the main molecular mechanisms involved in metal tolerance in haloarchaea and focuses on factors such as salinity and metal speciation that affect the bioavailability of metals to haloarchaea. Global transcriptomic analysis during metal stress in these organisms will help in determining the various factors differentially regulated and essential for metal physiology. PMID:23533331

Progress and challenges in understanding planar cell polarity signaling.

PubMed

Axelrod, Jeffrey D

2009-10-01

During development, epithelial cells in some tissues acquire a polarity orthogonal to their apical-basal axis. This polarity, referred to as planar cell polarity (PCP), or tissue polarity, is essential for the normal physiological function of many epithelia. Early studies of PCP focused on insect epithelia (Lawrence, 1966 [1]), and the earliest genetic analyses were carried out in Drosophila (Held et al., 1986; Gubb and Garcia-Bellido, 1982 [2,3]). Indeed, most of our mechanistic understanding of PCP derives from the ongoing use of Drosophila as a model system. However, a range of medically important developmental defects and physiological processes are under the control of PCP mechanisms that appear to be at least partially conserved, driving considerable interest in studying PCP both in Drosophila and in vertebrate model systems. Here, I present a model of the PCP signaling mechanism based on studies in Drosophila. I highlight two areas in which our understanding is deficient, and which lead to current confusion in the literature. Future studies that shed light on these areas will substantially enhance our understanding of the fascinating yet challenging problem of understanding the mechanisms that generate PCP.

Sensory reception of the primer pheromone ethyl oleate

NASA Astrophysics Data System (ADS)

Muenz, Thomas S.; Maisonnasse, Alban; Plettner, Erika; Le Conte, Yves; Rössler, Wolfgang

2012-05-01

Social work force distribution in honeybee colonies critically depends on subtle adjustments of an age-related polyethism. Pheromones play a crucial role in adjusting physiological and behavioral maturation of nurse bees to foragers. In addition to primer effects of brood pheromone and queen mandibular pheromone—both were shown to influence onset of foraging—direct worker-worker interactions influence adult behavioral maturation. These interactions were narrowed down to the primer pheromone ethyl oleate, which is present at high concentrations in foragers, almost absent in young bees and was shown to delay the onset of foraging. Based on chemical analyses, physiological recordings from the antenna (electroantennograms) and the antennal lobe (calcium imaging), and behavioral assays (associative conditioning of the proboscis extension response), we present evidence that ethyl oleate is most abundant on the cuticle, received by olfactory receptors on the antenna, processed in glomeruli of the antennal lobe, and learned in olfactory centers of the brain. The results are highly suggestive that the primer pheromone ethyl oleate is transmitted and perceived between individuals via olfaction at close range.

Molecular Mechanisms of Fibroblast Growth Factor Signaling in Physiology and Pathology

PubMed Central

Belov, Artur A.; Mohammadi, Moosa

2013-01-01

Fibroblast growth factors (FGFs) signal in a paracrine or endocrine fashion to mediate a myriad of biological activities, ranging from issuing developmental cues, maintaining tissue homeostasis, and regulating metabolic processes. FGFs carry out their diverse functions by binding and dimerizing FGF receptors (FGFRs) in a heparan sulfate (HS) cofactor- or Klotho coreceptor-assisted manner. The accumulated wealth of structural and biophysical data in the past decade has transformed our understanding of the mechanism of FGF signaling in human health and development, and has provided novel concepts in receptor tyrosine kinase (RTK) signaling. Among these contributions are the elucidation of HS-assisted receptor dimerization, delineation of the molecular determinants of ligand–receptor specificity, tyrosine kinase regulation, receptor cis-autoinhibition, and tyrosine trans-autophosphorylation. These structural studies have also revealed how disease-associated mutations highjack the physiological mechanisms of FGFR regulation to contribute to human diseases. In this paper, we will discuss the structurally and biophysically derived mechanisms of FGF signaling, and how the insights gained may guide the development of therapies for treatment of a diverse array of human diseases. PMID:23732477

Molecular mechanisms of fibroblast growth factor signaling in physiology and pathology.

PubMed

Belov, Artur A; Mohammadi, Moosa

2013-06-01

Fibroblast growth factors (FGFs) signal in a paracrine or endocrine fashion to mediate a myriad of biological activities, ranging from issuing developmental cues, maintaining tissue homeostasis, and regulating metabolic processes. FGFs carry out their diverse functions by binding and dimerizing FGF receptors (FGFRs) in a heparan sulfate (HS) cofactor- or Klotho coreceptor-assisted manner. The accumulated wealth of structural and biophysical data in the past decade has transformed our understanding of the mechanism of FGF signaling in human health and development, and has provided novel concepts in receptor tyrosine kinase (RTK) signaling. Among these contributions are the elucidation of HS-assisted receptor dimerization, delineation of the molecular determinants of ligand-receptor specificity, tyrosine kinase regulation, receptor cis-autoinhibition, and tyrosine trans-autophosphorylation. These structural studies have also revealed how disease-associated mutations highjack the physiological mechanisms of FGFR regulation to contribute to human diseases. In this paper, we will discuss the structurally and biophysically derived mechanisms of FGF signaling, and how the insights gained may guide the development of therapies for treatment of a diverse array of human diseases.

Physiological and environmental control of yeast prions

PubMed Central

Chernova, Tatiana A.; Wilkinson, Keith D.; Chernoff, Yury O.

2014-01-01

Prions are self-perpetuating protein isoforms that cause fatal and incurable neurodegenerative disease in mammals. Recent evidence indicates that a majority of human proteins involved in amyloid and neural inclusion disorders possess at least some prion properties. In lower eukaryotes, such as yeast, prions act as epigenetic elements, which increase phenotypic diversity by altering a range of cellular processes. While some yeast prions are clearly pathogenic, it is also postulated that prion formation could be beneficial in variable environmental conditions. Yeast and mammalian prions have similar molecular properties. Crucial cellular factors and conditions influencing prion formation and propagation were uncovered in the yeast models. Stress-related chaperones, protein quality control deposits, degradation pathways and cytoskeletal networks control prion formation and propagation in yeast. Environmental stresses trigger prion formation and loss, supposedly acting via influencing intracellular concentrations of the prion-inducing proteins, and/or by localizing prionogenic proteins to the prion induction sites via heterologous ancillary helpers. Physiological and environmental modulation of yeast prions points to new opportunities for pharmacological intervention and/or prophylactic measures targeting general cellular systems rather than the properties of individual amyloids and prions. PMID:24236638

System Theory and Physiological Processes.

PubMed

Jones, R W

1963-05-03

Engineers and physiologists working together in experimental and theoretical studies predict that the application of system analysis to biological processes will increase understanding of these processes and broaden the base of system theory. Richard W. Jones, professor of electrical engineering at Northwestern University, Evanston, Illinois, and John S. Gray, professor of physiology at Northwestern's Medical School, discuss these developments. Their articles are adapted from addresses delivered in Chicago in November 1962 at the 15th Annual Conference on Engineering in Medicine and Biology.

Effects of Microclimate Cooling on Physiology and Performance While Flying the UH-60 Helicopter Simulator in NBC Conditions in a Controlled Heat Environment

DTIC Science & Technology

1992-08-01

including instrumenting and dressing the subjects, monitoring the physiological parameters in the simulator, and collecting and processing data. They...also was decided to extend the recruiting process to include all helicopter aviators, even if not UH-60 qualified. There is little in the flight profile...parameter channels, and the data were processed to produce a single root mean square (RMS) error value for each channel appropriate to each of the 9

Physiology and pathophysiology of apoptosis in epithelial cells of the liver, pancreas, and intestine.

PubMed

Jones, B A; Gores, G J

1997-12-01

Cell death of gastrointestinal epithelial cells occurs by a process referred to as apoptosis. In this review, we succinctly define apoptosis and summarize the role of apoptosis in the physiology and pathophysiology of epithelial cells in the liver, pancreas, and small and large intestine. The physiological mediators regulating apoptosis in gastrointestinal epithelial cells, when known, are discussed. Selected pathophysiological consequences of excessive apoptosis and inhibition of apoptosis are used to illustrate the significance of apoptosis in disease processes. These examples demonstrate that excessive apoptosis may result in epithelial cell atrophy, injury, and dysfunction, whereas inhibition of apoptosis results in hyperplasia and promotes malignant transformation. The specific cellular mechanisms responsible for dysregulation of epithelial cell apoptosis during pathophysiological disturbances are emphasized. Potential future areas of physiological research regarding apoptosis in gastrointestinal epithelia are highlighted when appropriate.

Reintrepreting the cardiovascular system as a mechanical model

NASA Astrophysics Data System (ADS)

Lemos, Diogo; Machado, José; Minas, Graça; Soares, Filomena; Barros, Carla; Leão, Celina Pinto

2013-10-01

The simulation of the different physiological systems is very useful as a pedagogical tool, allowing a better understanding of the mechanisms and the functions of the processes. The observation of the physiological phenomena through mechanical simulators represents a great asset. Furthermore, the development of these simulators allows reinterpreting physiological systems, with the advantage of using the same transducers and sensors that are commonly used in diagnostic and therapeutic cardiovascular procedures for the monitoring of system' parameters. The cardiovascular system is one of the most important systems of the human body and has been the target of several biomedical studies. The present work describes a mechanical simulation of the cardiovascular system, in particularly, the systemic circulation, which can be described in terms of its hemodynamic variables. From the mechanical process and parameters, physiological system's behavior was reproduced, as accurately as possible.

Functions and Mechanisms of Sleep

PubMed Central

Zielinski, Mark R.; McKenna, James T.; McCarley, Robert W.

2017-01-01

Sleep is a complex physiological process that is regulated globally, regionally, and locally by both cellular and molecular mechanisms. It occurs to some extent in all animals, although sleep expression in lower animals may be co-extensive with rest. Sleep regulation plays an intrinsic part in many behavioral and physiological functions. Currently, all researchers agree there is no single physiological role sleep serves. Nevertheless, it is quite evident that sleep is essential for many vital functions including development, energy conservation, brain waste clearance, modulation of immune responses, cognition, performance, vigilance, disease, and psychological state. This review details the physiological processes involved in sleep regulation and the possible functions that sleep may serve. This description of the brain circuitry, cell types, and molecules involved in sleep regulation is intended to further the reader’s understanding of the functions of sleep. PMID:28413828

Free fatty acid receptors and their role in regulation of energy metabolism.

PubMed

Hara, Takafumi; Kimura, Ikuo; Inoue, Daisuke; Ichimura, Atsuhiko; Hirasawa, Akira

2013-01-01

The free fatty acid receptor (FFAR) is a G protein-coupled receptor (GPCR) activated by free fatty acids (FFAs), which play important roles not only as essential nutritional components but also as signaling molecules in numerous physiological processes. In the last decade, FFARs have been identified by the GPCR deorphanization strategy derived from the human genome database. To date, several FFARs have been identified and characterized as critical components in various physiological processes. FFARs are categorized according to the chain length of FFA ligands that activate each FFAR; FFA2 and FFA3 are activated by short chain FFAs, GPR84 is activated by medium-chain FFAs, whereas FFA1 and GPR120 are activated by medium- or long-chain FFAs. FFARs appear to act as physiological sensors for food-derived FFAs and digestion products in the gastrointestinal tract. Moreover, they are considered to be involved in the regulation of energy metabolism mediated by the secretion of insulin and incretin hormones and by the regulation of the sympathetic nerve systems, taste preferences, and inflammatory responses related to insulin resistance. Therefore, because FFARs can be considered to play important roles in physiological processes and various pathophysiological processes, FFARs have been targeted in therapeutic strategies for the treatment of metabolic disorders including type 2 diabetes and metabolic syndrome. In this review, we present a summary of recent progress regarding the understanding of their physiological roles in the regulation of energy metabolism and their potential as therapeutic targets.

The Impact of Climate Trends on a Tick Affecting Public Health: A Retrospective Modeling Approach for Hyalomma marginatum (Ixodidae)

PubMed Central

Estrada-Peña, Agustín; de la Fuente, José; Latapia, Tamara; Ortega, Carmelo

2015-01-01

The impact of climate trends during the period 1901–2009 on the life cycle of Hyalomma marginatum in Europe was modeled to assess changes in the physiological processes of this threat to public health. Monthly records of temperature and water vapour at a resolution of 0.5° and equations describing the life cycle processes of the tick were used. The climate in the target region affected the rates of the life cycle processes of H. marginatum: development rates increased, mortality rates in molting stages decreased, and the survival rates of questing ticks decreased in wide territories of the Mediterranean basin. The modeling framework indicated the existence of critical areas in the Balkans, central Europe, and the western coast of France, where the physiological processes of the tick improved to extents that are consistent with the persistence of populations if introduced. A spatially explicit risk assessment was performed to detect candidate areas where active surveys should be performed to monitor changes in tick density or persistence after a hypothetical introduction. We detected areas where the critical abiotic (climate) and biotic (host density) factors overlap, including most of the Iberian peninsula, the Mediterranean coast of France, eastern Turkey, and portions of the western Black Sea region. Wild ungulate densities are unavailable for large regions of the territory, a factor that might affect the outcome of the study. The risk of successfully establishing H. marginatum populations at northern latitudes of its current colonization range seems to be still low, even if the climate has improved the performance of the tick in these areas. PMID:25955315

The Impact of Climate Trends on a Tick Affecting Public Health: A Retrospective Modeling Approach for Hyalomma marginatum (Ixodidae).

PubMed

Estrada-Peña, Agustín; de la Fuente, José; Latapia, Tamara; Ortega, Carmelo

2015-01-01

The impact of climate trends during the period 1901-2009 on the life cycle of Hyalomma marginatum in Europe was modeled to assess changes in the physiological processes of this threat to public health. Monthly records of temperature and water vapour at a resolution of 0.5° and equations describing the life cycle processes of the tick were used. The climate in the target region affected the rates of the life cycle processes of H. marginatum: development rates increased, mortality rates in molting stages decreased, and the survival rates of questing ticks decreased in wide territories of the Mediterranean basin. The modeling framework indicated the existence of critical areas in the Balkans, central Europe, and the western coast of France, where the physiological processes of the tick improved to extents that are consistent with the persistence of populations if introduced. A spatially explicit risk assessment was performed to detect candidate areas where active surveys should be performed to monitor changes in tick density or persistence after a hypothetical introduction. We detected areas where the critical abiotic (climate) and biotic (host density) factors overlap, including most of the Iberian peninsula, the Mediterranean coast of France, eastern Turkey, and portions of the western Black Sea region. Wild ungulate densities are unavailable for large regions of the territory, a factor that might affect the outcome of the study. The risk of successfully establishing H. marginatum populations at northern latitudes of its current colonization range seems to be still low, even if the climate has improved the performance of the tick in these areas.

Molecular and Chemical Genetic Approaches to Developmental Origins of Aging and Disease in Zebrafish

PubMed Central

Sasaki, Tomoyuki; Kishi, Shuji

2013-01-01

The incidence of diseases increases rapidly with age, accompanied by progressive deteriorations of physiological functions in organisms. Aging-associated diseases are sporadic but mostly inevitable complications arising from senescence. Senescence is often considered the antithesis of early development, but yet there may be factors and mechanisms in common between these two phenomena over the dynamic process of aging. The association between early development and late-onset disease with advancing age is thought to come from a consequence of developmental plasticity, the phenomenon by which one genotype can give rise to a range of physiologically and/or morphologically adaptive states in response to different environmental or genetic perturbations. On the one hand, we hypothesized that the future aging process can be predictive based on adaptivity during the early developmental period. Modulating the thresholds of adaptive plasticity by chemical genetic approaches, we have been investigating whether any relationship exists between the regulatory mechanisms that function in early development and in senescence using the zebrafish (Danio rerio), a small freshwater fish and a useful model animal for genetic studies. We have successfully conducted experiments to isolate zebrafish mutants expressing apparently altered senescence phenotypes during embryogenesis (“embryonic senescence”), subsequently showing shortened lifespan in adulthoods. We anticipate that previously uncharacterized developmental genes may mediate the aging process and play a pivotal role in senescence. On the other hand, unexpected senescence-related genes might also be involved in the early developmental process and regulation. The ease of manipulation using the zebrafish system allows us to conduct an exhaustive exploration of novel genes and small molecular compounds that can be linked to the senescence phenotype, and thereby facilitates searching for the evolutionary and developmental origins of aging in vertebrates. PMID:23660559

Biological effects of exposure to static electric fields in humans and vertebrates: a systematic review.

PubMed

Petri, Anne-Kathrin; Schmiedchen, Kristina; Stunder, Dominik; Dechent, Dagmar; Kraus, Thomas; Bailey, William H; Driessen, Sarah

2017-04-17

High-voltage direct current (HVDC) lines are the technology of choice for the transport of large amounts of energy over long distances. The operation of these lines produces static electric fields (EF), but the data reviewed in previous assessments were not sufficient to assess the need for any environmental limit. The aim of this systematic review was to update the current state of research and to evaluate biological effects of static EF. Using the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) recommendations, we collected and evaluated experimental and epidemiological studies examining biological effects of exposure to static EF in humans (n = 8) and vertebrates (n = 40). There is good evidence that humans and animals are able to perceive the presence of static EF at sufficiently high levels. Hair movements caused by electrostatic forces may play a major role in this perception. A large number of studies reported responses of animals (e.g., altered metabolic, immunologic or developmental parameters) to a broad range of static EF strengths as well, but these responses are likely secondary physiological responses to sensory stimulation. Furthermore, the quality of many of the studies reporting physiological responses is poor, which raises concerns about confounding. The weight of the evidence from the literature reviewed did not indicate that static EF have adverse biological effects in humans or animals. The evidence strongly supported the role of superficial sensory stimulation of hair and skin as the basis for perception of the field, as well as reported indirect behavioral and physiological responses. Physical considerations also preclude any direct effect of static EF on internal physiology, and reports that some physiological processes are affected in minor ways may be explained by other factors. While this literature does not support a level of concern about biological effects of exposure to static EF, the conditions that affect thresholds for human detection and possible annoyance at suprathreshold levels should be investigated.

Effects of aging and Parkinson's disease on motor unit remodeling: influence of resistance exercise training.

PubMed

Kelly, Neil A; Hammond, Kelley G; Bickel, C Scott; Windham, Samuel T; Tuggle, S Craig; Bamman, Marcas M

2018-04-01

Aging muscle atrophy is in part a neurodegenerative process revealed by denervation/reinnervation events leading to motor unit remodeling (i.e., myofiber type grouping). However, this process and its physiological relevance are poorly understood, as is the wide-ranging heterogeneity among aging humans. Here, we attempted to address 1) the relation between myofiber type grouping and molecular regulators of neuromuscular junction (NMJ) stability; 2) the impact of motor unit remodeling on recruitment during submaximal contractions; 3) the prevalence and impact of motor unit remodeling in Parkinson's disease (PD), an age-related neurodegenerative disease; and 4) the influence of resistance exercise training (RT) on regulators of motor unit remodeling. We compared type I myofiber grouping, molecular regulators of NMJ stability, and the relative motor unit activation (MUA) requirement during a submaximal sit-to-stand task among untrained but otherwise healthy young (YA; 26 yr, n = 27) and older (OA; 66 yr, n = 91) adults and OA with PD (PD; 67 yr, n = 19). We tested the effects of RT on these outcomes in OA and PD. PD displayed more motor unit remodeling, alterations in NMJ stability regulation, and a higher relative MUA requirement than OA, suggesting PD-specific effects. The molecular and physiological outcomes tracked with the severity of type I myofiber grouping. Together these findings suggest that age-related motor unit remodeling, manifested by type I myofiber grouping, 1) reduces MUA efficiency to meet submaximal contraction demand, 2) is associated with disruptions in NMJ stability, 3) is further impacted by PD, and 4) may be improved by RT in severe cases. NEW & NOTEWORTHY Because the physiological consequences of varying amounts of myofiber type grouping are unknown, the current study aims to characterize the molecular and physiological correlates of motor unit remodeling. Furthermore, because exercise training has demonstrated neuromuscular benefits in aged humans and improved innervation status and neuromuscular junction integrity in animals, we provide an exploratory analysis of the effects of high-intensity resistance training on markers of neuromuscular degeneration in both Parkinson's disease (PD) and age-matched older adults.

Multidimensional Characterization and Differentiation of Neurons in the Anteroventral Cochlear Nucleus

PubMed Central

Typlt, Marei; Englitz, Bernhard; Sonntag, Mandy; Dehmel, Susanne; Kopp-Scheinpflug, Cornelia; Ruebsamen, Rudolf

2012-01-01

Multiple parallel auditory pathways ascend from the cochlear nucleus. It is generally accepted that the origin of these pathways are distinct groups of neurons differing in their anatomical and physiological properties. In extracellular in vivo recordings these neurons are typically classified on the basis of their peri-stimulus time histogram. In the present study we reconsider the question of classification of neurons in the anteroventral cochlear nucleus (AVCN) by taking a wider range of response properties into account. The study aims at a better understanding of the AVCN's functional organization and its significance as the source of different ascending auditory pathways. The analyses were based on 223 neurons recorded in the AVCN of the Mongolian gerbil. The range of analysed parameters encompassed spontaneous activity, frequency coding, sound level coding, as well as temporal coding. In order to categorize the unit sample without any presumptions as to the relevance of certain response parameters, hierarchical cluster analysis and additional principal component analysis were employed which both allow a classification on the basis of a multitude of parameters simultaneously. Even with the presently considered wider range of parameters, high number of neurons and more advanced analytical methods, no clear boundaries emerged which would separate the neurons based on their physiology. At the current resolution of the analysis, we therefore conclude that the AVCN units more likely constitute a multi-dimensional continuum with different physiological characteristics manifested at different poles. However, more complex stimuli could be useful to uncover physiological differences in future studies. PMID:22253838

Assessing formal teaching of ethics in physiology: an empirical survey, patterns, and recommendations.

PubMed

Goswami, Nandu; Batzel, Jerry Joseph; Hinghofer-Szalkay, Helmut

2012-09-01

Ethics should be an important component of physiological education. In this report, we examined to what extent teaching of ethics is formally being incorporated into the physiology curriculum. We carried out an e-mail survey in which we asked the e-mail recipients whether their institution offered a course or lecture on ethics as part of the physiology teaching process at their institution, using the following query: "We are now doing an online survey in which we would like to know whether you offer a course or a lecture on ethics as part of your physiology teaching curriculum." The response rate was 53.3%: we received 104 responses of a total of 195 sent out. Our responses came from 45 countries. While all of our responders confirmed that there was a need for ethics during medical education and scientific training, the degree of inclusion of formal ethics in the physiology curriculum varied widely. Our survey showed that, in most cases (69%), including at our Medical University of Graz, ethics in physiology is not incorporated into the physiology curriculum. Given this result, we suggest specific topics related to ethics and ethical considerations that could be integrated into the physiology curriculum. We present here a template example of a lecture "Teaching Ethics in Physiology" (structure, content, examples, and references), which was based on guidelines and case reports provided by experts in this area (e.g., Benos DJ. Ethics revisited. Adv Physiol Educ 25: 189-190, 2001). This lecture, which we are presently using in Graz, could be used as a base that could lead to greater awareness of important ethical issues in students at an early point in the educational process.

Physiology and pathogenesis of gastroesophageal reflux disease.

PubMed

Mikami, Dean J; Murayama, Kenric M

2015-06-01

Gastroesophageal reflux disease (GERD) is one of the most common problems treated by primary care physicians. Almost 20% of the population in the United States experiences occasional regurgitation, heartburn, or retrosternal pain because of GERD. Reflux disease is complex, and the physiology and pathogenesis are still incompletely understood. However, abnormalities of any one or a combination of the three physiologic processes, namely, esophageal motility, lower esophageal sphincter function, and gastric motility or emptying, can lead to GERD. There are many diagnostic and therapeutic approaches to GERD today, but more studies are needed to better understand this complex disease process. Copyright © 2015 Elsevier Inc. All rights reserved.

ABNORMAL ALDOSTERONE PHYSIOLOGY AND CARDIO-METABOLIC RISK FACTORS

PubMed Central

Vaidya, Anand; Underwood, Patricia C.; Hopkins, Paul N.; Jeunemaitre, Xavier; Ferri, Claudio; Williams, Gordon H.; Adler, Gail K.

2013-01-01

Abnormal aldosterone physiology has been implicated in the pathogenesis of cardio-metabolic diseases. Single aldosterone measurements capture only a limited range of aldosterone physiology. New methods of characterizing aldosterone physiology may provide a more comprehensive understanding of its relationship with cardio-metabolic disease. We evaluated whether novel indices of aldosterone responses to dietary sodium modulation, the Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI for serum and SAUSSI for urine), could predict cardio-metabolic risk factors. We performed cross-sectional analyses on 539 subjects studied on liberal (LIB) and restricted (RES) sodium diets with serum and urinary aldosterone measurements. SASSI and SAUSSI were calculated as the ratio of aldosterone on LIB (maximally suppressed aldosterone) to aldosterone on RES (stimulated aldosterone) diets, and associated with risk factors using adjusted regression models. Cardio-metabolic risk factors associated with either impaired suppression of aldosterone on LIB diet, or impaired stimulation on RES diet, or both; in all of these individual cases, these risk factors associated with higher SASSI or SAUSSI. In the context of abnormalities that comprise the metabolic syndrome (MetS), there was a strong positive association between the number of MetS components (0–4) and both SASSI and SAUSSI (P<0.0001) that was independent of known aldosterone secretagogues (angiotensin II, corticotropin, potassium). SASSI and SAUSSI exhibited a high sensitivity in detecting normal individuals with zero MetS components (86% for SASSI and 83% for SAUSSI). Assessing the physiologic range of aldosterone responses may provide greater insights into adrenal pathophysiology. Dysregulated aldosterone physiology may contribute to, and/or result from, early cardio-metabolic abnormalities. PMID:23399714

A theoretical individual-based model of Brown Ring Disease in Manila clams, Venerupis philippinarum

NASA Astrophysics Data System (ADS)

Paillard, Christine; Jean, Fred; Ford, Susan E.; Powell, Eric N.; Klinck, John M.; Hofmann, Eileen E.; Flye-Sainte-Marie, Jonathan

2014-08-01

An individual-based mathematical model was developed to investigate the biological and environmental interactions that influence the prevalence and intensity of Brown Ring Disease (BRD), a disease, caused by the bacterial pathogen, Vibrio tapetis, in the Manila clam (Venerupis (= Tapes, = Ruditapes) philippinarum). V. tapetis acts as an external microparasite, adhering at the surface of the mantle edge and its secretion, the periostracal lamina, causing the symptomatic brown deposit. Brown Ring Disease is atypical in that it leaves a shell scar that provides a unique tool for diagnosis of either live or dead clams. The model was formulated using laboratory and field measurements of BRD development in Manila clams, physiological responses of the clam to the pathogen, and the physiology of V. tapetis, as well as theoretical understanding of bacterial disease progression in marine shellfish. The simulation results obtained for an individual Manila clam were expanded to cohorts and populations using a probability distribution that prescribed a range of variability for parameters in a three dimensional framework; assimilation rate, clam hemocyte activity rate (the number of bacteria ingested per hemocyte per day), and clam calcification rate (a measure of the ability to recover by covering over the symptomatic brown ring deposit), which sensitivity studies indicated to be processes important in determining BRD prevalence and intensity. This approach allows concurrent simulation of individuals with a variety of different physiological capabilities (phenotypes) and hence by implication differing genotypic composition. Different combinations of the three variables provide robust estimates for the fate of individuals with particular characteristics in a population that consists of mixtures of all possible combinations. The BRD model was implemented using environmental observations from sites in Brittany, France, where Manila clams routinely exhibit BRD signs. The simulated annual cycle of BRD prevalence and intensity agrees with observed disease cycles in cultured clam populations from this region, with maximum disease prevalence and intensity occurring from December to April. Sensitivity analyses of modeled physiological processes showed that the level of hemocyte activity is the primary intrinsic determinant of recovery of infected clams. Simulations designed to investigate environmental effects on BRD suggested that the outcome of the host-parasite interaction is dependent on food supply (high values being favorable for the host) and temperature. Results of simulations illustrate the complex interaction of temperature effects on propagation and viability of the bacterium, on the phagocytic activity of the hemocytes, and on other physiological processes of the host clam. Simulations using 1 °C and 2 °C increases in temperature generally favored disease development, indicating that climate warming might favor the spread of BRD.

The physiological ecology of the supratidal amphipod Talorchestia longicornis.

PubMed

Ramus, Aaron P; Forward, Richard B

2012-02-01

Physiology, behavior, habitat, and morphology are used to determine the degree of adaptation to life on land for amphipod species and systemization within the four functional groups of the family talitridae. Talorchestia longicornis is a semi-terrestrial amphipod found in the supratidal zone of estuaries. The present study investigates the physiological adaptations of this species to life on land through measurements of osmoregulation and respiration. Over the salinity range of 1-40‰, T. longicornis regulated its hemolymph hyperosmotically at low salinities and hypoosmotically at high salinities. The isosmotic point was about 27‰. Analogously, hemolymph chloride levels were well regulated being hyperionic at low salinities and hypoionic at high salinities. This species is capable of respiration in both air and water. Slopes (b values) of the relationship between weight and oxygen uptake rates ranged from 0.316 to 0.590. Oxygen uptake rates were higher in air than water and at night versus day. Q(10) values were slightly below 2.0 for respiration in air for amphipods, irrespective of weight. These physiological adaptations, along with its behaviors, habitat, and morphology, place T. longicornis within the Group III sandhoppers of the Talitridae. Copyright © 2011. Published by Elsevier Inc.

Genetic approaches in comparative and evolutionary physiology

PubMed Central

Bridgham, Jamie T.; Kelly, Scott A.; Garland, Theodore

2015-01-01

Whole animal physiological performance is highly polygenic and highly plastic, and the same is generally true for the many subordinate traits that underlie performance capacities. Quantitative genetics, therefore, provides an appropriate framework for the analysis of physiological phenotypes and can be used to infer the microevolutionary processes that have shaped patterns of trait variation within and among species. In cases where specific genes are known to contribute to variation in physiological traits, analyses of intraspecific polymorphism and interspecific divergence can reveal molecular mechanisms of functional evolution and can provide insights into the possible adaptive significance of observed sequence changes. In this review, we explain how the tools and theory of quantitative genetics, population genetics, and molecular evolution can inform our understanding of mechanism and process in physiological evolution. For example, lab-based studies of polygenic inheritance can be integrated with field-based studies of trait variation and survivorship to measure selection in the wild, thereby providing direct insights into the adaptive significance of physiological variation. Analyses of quantitative genetic variation in selection experiments can be used to probe interrelationships among traits and the genetic basis of physiological trade-offs and constraints. We review approaches for characterizing the genetic architecture of physiological traits, including linkage mapping and association mapping, and systems approaches for dissecting intermediary steps in the chain of causation between genotype and phenotype. We also discuss the promise and limitations of population genomic approaches for inferring adaptation at specific loci. We end by highlighting the role of organismal physiology in the functional synthesis of evolutionary biology. PMID:26041111

Multiscale mechanistic modeling in pharmaceutical research and development.

PubMed

Kuepfer, Lars; Lippert, Jörg; Eissing, Thomas

2012-01-01

Discontinuation of drug development projects due to lack of efficacy or adverse events is one of the main cost drivers in pharmaceutical research and development (R&D). Investments have to be written-off and contribute to the total costs of a successful drug candidate receiving marketing authorization and allowing return on invest. A vital risk for pharmaceutical innovator companies is late stage clinical failure since costs for individual clinical trials may exceed the one billion Euro threshold. To guide investment decisions and to safeguard maximum medical benefit and safety for patients recruited in clinical trials, it is therefore essential to understand the clinical consequences of all information and data generated. The complexity of the physiological and pathophysiological processes and the sheer amount of information available overcharge the mental capacity of any human being and prevent a prediction of the success in clinical development. A rigorous integration of knowledge, assumption, and experimental data into computational models promises a significant improvement of the rationalization of decision making in pharmaceutical industry. We here give an overview of the current status of modeling and simulation in pharmaceutical R&D and outline the perspectives of more recent developments in mechanistic modeling. Specific modeling approaches for different biological scales ranging from intracellular processes to whole organism physiology are introduced and an example for integrative multiscale modeling of therapeutic efficiency in clinical oncology trials is showcased.

Contributions of Nonhuman Primates to Research on Aging

PubMed Central

Didier, E. S.; MacLean, A. G.; Mohan, M.; Didier, P. J.; Lackner, A. A.; Kuroda, M. J.

2016-01-01

Aging is the biological process of declining physiologic function associated with increasing mortality rate during advancing age. Humans and higher nonhuman primates exhibit unusually longer average life spans as compared with mammals of similar body mass. Furthermore, the population of humans worldwide is growing older as a result of improvements in public health, social services, and health care systems. Comparative studies among a wide range of organisms that include nonhuman primates contribute greatly to our understanding about the basic mechanisms of aging. Based on their genetic and physiologic relatedness to humans, nonhuman primates are especially important for better understanding processes of aging unique to primates, as well as for testing intervention strategies to improve healthy aging and to treat diseases and disabilities in older people. Rhesus and cynomolgus macaques are the predominant monkeys used in studies on aging, but research with lower nonhuman primate species is increasing. One of the priority topics of research about aging in nonhuman primates involves neurologic changes associated with cognitive decline and neurodegenerative diseases. Additional areas of research include osteoporosis, reproductive decline, caloric restriction, and their mimetics, as well as immune senescence and chronic inflammation that affect vaccine efficacy and resistance to infections and cancer. The purpose of this review is to highlight the findings from nonhuman primate research that contribute to our understanding about aging and health span in humans. PMID:26869153

Hydrodynamics in Cell Studies

PubMed Central

2018-01-01

Hydrodynamic phenomena are ubiquitous in living organisms and can be used to manipulate cells or emulate physiological microenvironments experienced in vivo. Hydrodynamic effects influence multiple cellular properties and processes, including cell morphology, intracellular processes, cell–cell signaling cascades and reaction kinetics, and play an important role at the single-cell, multicellular, and organ level. Selected hydrodynamic effects can also be leveraged to control mechanical stresses, analyte transport, as well as local temperature within cellular microenvironments. With a better understanding of fluid mechanics at the micrometer-length scale and the advent of microfluidic technologies, a new generation of experimental tools that provide control over cellular microenvironments and emulate physiological conditions with exquisite accuracy is now emerging. Accordingly, we believe that it is timely to assess the concepts underlying hydrodynamic control of cellular microenvironments and their applications and provide some perspective on the future of such tools in in vitro cell-culture models. Generally, we describe the interplay between living cells, hydrodynamic stressors, and fluid flow-induced effects imposed on the cells. This interplay results in a broad range of chemical, biological, and physical phenomena in and around cells. More specifically, we describe and formulate the underlying physics of hydrodynamic phenomena affecting both adhered and suspended cells. Moreover, we provide an overview of representative studies that leverage hydrodynamic effects in the context of single-cell studies within microfluidic systems. PMID:29420889

Method to investigate temporal dynamics of ganglion and other retinal cells in the living human eye

NASA Astrophysics Data System (ADS)

Kurokawa, Kazuhiro; Liu, Zhuolin; Crowell, James; Zhang, Furu; Miller, Donald T.

2018-02-01

The inner retina is critical for visual processing, but much remains unknown about its neural circuitry and vulnerability to disease. A major bottleneck has been our inability to observe the structure and function of the cells composing these retinal layers in the living human eye. Here, we present a noninvasive method to observe both structural and functional information. Adaptive optics optical coherence tomography (AO-OCT) is used to resolve the inner retinal cells in all three dimensions and novel post processing algorithms are applied to extract structure and physiology down to the cellular level. AO-OCT captured the 3D mosaic of individual ganglion cell somas, retinal nerve fiber bundles of micron caliber, and microglial cells, all in exquisite detail. Time correlation analysis of the AO-OCT videos revealed notable temporal differences between the principal layers of the inner retina. The GC layer was more dynamic than the nerve fiber and inner plexiform layers. At the cellular level, we applied a customized correlation method to individual GCL somas, and found a mean time constant of activity of 0.57 s and spread of +/-0.1 s suggesting a range of physiological dynamics even in the same cell type. Extending our method to slower dynamics (from minutes to one year), time-lapse imaging and temporal speckle contrast revealed appendage and soma motion of resting microglial cells at the retinal surface.

Contributions of Nonhuman Primates to Research on Aging.

PubMed

Didier, E S; MacLean, A G; Mohan, M; Didier, P J; Lackner, A A; Kuroda, M J

2016-03-01

Aging is the biological process of declining physiologic function associated with increasing mortality rate during advancing age. Humans and higher nonhuman primates exhibit unusually longer average life spans as compared with mammals of similar body mass. Furthermore, the population of humans worldwide is growing older as a result of improvements in public health, social services, and health care systems. Comparative studies among a wide range of organisms that include nonhuman primates contribute greatly to our understanding about the basic mechanisms of aging. Based on their genetic and physiologic relatedness to humans, nonhuman primates are especially important for better understanding processes of aging unique to primates, as well as for testing intervention strategies to improve healthy aging and to treat diseases and disabilities in older people. Rhesus and cynomolgus macaques are the predominant monkeys used in studies on aging, but research with lower nonhuman primate species is increasing. One of the priority topics of research about aging in nonhuman primates involves neurologic changes associated with cognitive decline and neurodegenerative diseases. Additional areas of research include osteoporosis, reproductive decline, caloric restriction, and their mimetics, as well as immune senescence and chronic inflammation that affect vaccine efficacy and resistance to infections and cancer. The purpose of this review is to highlight the findings from nonhuman primate research that contribute to our understanding about aging and health span in humans. © The Author(s) 2016.

Hydrogen Peroxide Signaling in Plant Development and Abiotic Responses: Crosstalk with Nitric Oxide and Calcium

PubMed Central

Niu, Lijuan; Liao, Weibiao

2016-01-01

Hydrogen peroxide (H2O2), as a reactive oxygen species, is widely generated in many biological systems. It has been considered as an important signaling molecule that mediates various physiological and biochemical processes in plants. Normal metabolism in plant cells results in H2O2 generation, from a variety of sources. Also, it is now clear that nitric oxide (NO) and calcium (Ca2+) function as signaling molecules in plants. Both H2O2 and NO are involved in plant development and abiotic responses. A wide range of evidences suggest that NO could be generated under similar stress conditions and with similar kinetics as H2O2. The interplay between H2O2 and NO has important functional implications to modulate transduction processes in plants. Moreover, close interaction also exists between H2O2 and Ca2+ in response to development and abiotic stresses in plants. Cellular responses to H2O2 and Ca2+ signaling systems are complex. There is quite a bit of interaction between H2O2 and Ca2+ signaling in responses to several stimuli. This review aims to introduce these evidences in our understanding of the crosstalk among H2O2, NO, and Ca2+ signaling which regulates plant growth and development, and other cellular and physiological responses to abiotic stresses. PMID:26973673

Critical issues in trace gas biogeochemistry and global change.

PubMed

Beerling, David J; Nicholas Hewitt, C; Pyle, John A; Raven, John A

2007-07-15

The atmospheric composition of trace gases and aerosols is determined by the emission of compounds from the marine and terrestrial biospheres, anthropogenic sources and their chemistry and deposition processes. Biogenic emissions depend upon physiological processes and climate, and the atmospheric chemistry is governed by climate and feedbacks involving greenhouse gases themselves. Understanding and predicting the biogeochemistry of trace gases in past, present and future climates therefore demands an interdisciplinary approach integrating across physiology, atmospheric chemistry, physics and meteorology. Here, we highlight critical issues raised by recent findings in all of these key areas to provide a framework for better understanding the past and possible future evolution of the atmosphere. Incorporating recent experimental and observational findings, especially the influence of CO2 on trace gas emissions from marine algae and terrestrial plants, into earth system models remains a major research priority. As we move towards this goal, archives of the concentration and isotopes of N2O and CH4 from polar ice cores extending back over 650,000 years will provide a valuable benchmark for evaluating such models. In the Pre-Quaternary, synthesis of theoretical modelling with geochemical and palaeontological evidence is also uncovering the roles played by trace gases in episodes of abrupt climatic warming and ozone depletion. Finally, observations and palaeorecords across a range of timescales allow assessment of the Earth's climate sensitivity, a metric influencing our ability to decide what constitutes 'dangerous' climate change.

Bridging different perspectives of the physiological and mathematical disciplines.

PubMed

Batzel, Jerry Joseph; Hinghofer-Szalkay, Helmut; Kappel, Franz; Schneditz, Daniel; Kenner, Thomas; Goswami, Nandu

2012-12-01

The goal of this report is to discuss educational approaches for bridging the different perspectives of the physiological and mathematical disciplines. These approaches can enhance the learning experience for physiology, medical, and mathematics students and simultaneously act to stimulate mathematical/physiological/clinical interdisciplinary research. While physiology education incorporates mathematics, via equations and formulas, it does not typically provide a foundation for interdisciplinary research linking mathematics and physiology. Here, we provide insights and ideas derived from interdisciplinary seminars involving mathematicians and physiologists that have been conducted over the last decade. The approaches described here can be used as templates for giving physiology and medical students insights into how sophisticated tools from mathematics can be applied and how the disciplines of mathematics and physiology can be integrated in research, thereby fostering a foundation for interdisciplinary collaboration. These templates are equally applicable to linking mathematical methods with other life and health sciences in the educational process.

Physiological responses to dyadic interactions are influenced by neurotypical adults' levels of autistic and empathy traits.

PubMed

Truzzi, Anna; Setoh, Peipei; Shinohara, Kazuyuki; Esposito, Gianluca

2016-10-15

Autistic traits are distributed on a continuum that ranges from non-clinical to clinical condition. Atypical responses to social situations represent a core feature of the Autism Spectrum Disorders phenotype. Here, we hypothesize that atypical physiological responses to social stimuli may predict non-clinical autistic and empathy traits levels. We measured physiological responses (heart rate, facial temperature) of 40 adults (20F) while showing them 24 movies representing dyadic interactions. Autistic traits were assessed through Autism Quotient questionnaire (AQ), while empathy traits were measured using the Empathy Quotient questionnaire (EQ). Opposite correlations between AQ and EQ scores and physiological responses were found. Analysis of physiological responses revealed that individuals with better social abilities, low AQ and high EQ, show opposite activation patterns compared to people with high AQ and low EQ. Findings show that physiological responses could be biomarkers for people's autistic traits and social abilities. Copyright © 2016 Elsevier Inc. All rights reserved.

The physiology of spacecraft and space suit atmosphere selection

NASA Astrophysics Data System (ADS)

Waligora, J. M.; Horrigan, D. J.; Nicogossian, A.

The majority of the environmental factors which comprise the spacecraft and space suit environments can be controlled at "Earth normal" values, at optimum values, or at other values decided upon by spacecraft designers. Factors which are considered in arriving at control values and control ranges of these parameters include physiological, engineering, operational cost, and safety considerations. Several of the physiologic considerations, including hypoxia and hyperoxia, hypercapnia, temperature regulation, and decompression sickness are identified and their impact on space craft and space suit atmosphere selection are considered. The past experience in controlling these parameters in U.S. and Soviet spacecraft and space suits and the associated physiological responses are reviewed. Current areas of physiological investigation relating to environmental factors in spacecraft are discussed, particularly decompression sickness which can occur as a result of change in pressure from Earth to spacecraft or spacecraft to space suit. Physiological considerations for long-term lunar or Martian missions will have different impacts on atmosphere selection and may result in the selection of atmospheres different than those currently in use.

Age-related alterations in the fractal scaling of cardiac interbeat interval dynamics

NASA Technical Reports Server (NTRS)

Iyengar, N.; Peng, C. K.; Morin, R.; Goldberger, A. L.; Lipsitz, L. A.

1996-01-01

We postulated that aging is associated with disruption in the fractallike long-range correlations that characterize healthy sinus rhythm cardiac interval dynamics. Ten young (21-34 yr) and 10 elderly (68-81 yr) rigorously screened healthy subjects underwent 120 min of continuous supine resting electrocardiographic recording. We analyzed the interbeat interval time series using standard time and frequency domain statistics and using a fractal measure, detrended fluctuation analysis, to quantify long-range correlation properties. In healthy young subjects, interbeat intervals demonstrated fractal scaling, with scaling exponents (alpha) from the fluctuation analysis close to a value of 1.0. In the group of healthy elderly subjects, the interbeat interval time series had two scaling regions. Over the short range, interbeat interval fluctuations resembled a random walk process (Brownian noise, alpha = 1.5), whereas over the longer range they resembled white noise (alpha = 0.5). Short (alpha s)- and long-range (alpha 1) scaling exponents were significantly different in the elderly subjects compared with young (alpha s = 1.12 +/- 0.19 vs. 0.90 +/- 0.14, respectively, P = 0.009; alpha 1 = 0.75 +/- 0.17 vs. 0.99 +/- 0.10, respectively, P = 0.002). The crossover behavior from one scaling region to another could be modeled as a first-order autoregressive process, which closely fit the data from four elderly subjects. This implies that a single characteristic time scale may be dominating heartbeat control in these subjects. The age-related loss of fractal organization in heartbeat dynamics may reflect the degradation of integrated physiological regulatory systems and may impair an individual's ability to adapt to stress.

A conceptual framework for homeostasis: development and validation.

PubMed

McFarland, Jenny; Wenderoth, Mary Pat; Michael, Joel; Cliff, William; Wright, Ann; Modell, Harold

2016-06-01

We have developed and validated a conceptual framework for understanding and teaching organismal homeostasis at the undergraduate level. The resulting homeostasis conceptual framework details critical components and constituent ideas underlying the concept of homeostasis. It has been validated by a broad range of physiology faculty members from community colleges, primarily undergraduate institutions, research universities, and medical schools. In online surveys, faculty members confirmed the relevance of each item in the framework for undergraduate physiology and rated the importance and difficulty of each. The homeostasis conceptual framework was constructed as a guide for teaching and learning of this critical core concept in physiology, and it also paves the way for the development of a concept inventory for homeostasis. Copyright © 2016 The American Physiological Society.

Literature Review and Annotated Bibliography: Water Requirements of Desert Ungulates

USGS Publications Warehouse

Cain, James W.; Krausman, Paul R.; Rosenstock, Steven S.; Turner, Jack C.

2005-01-01

Executive Summary Ungulates adapted to desert areas are able to survive extreme temperatures and limited water availability. This ability is largely due to behavioral, morphological, and physiological adaptations that allow these animals to avoid or tolerate extreme environmental conditions. The physiological adaptations possessed by ungulates for thermoregulation and maintenance of water balance have been the subject of numerous studies involving a wide range of species. In this report we review the behavioral, morphological, and physiological mechanisms used by ungulates and other desert mammals to maintain water and temperature balance in arid environments. We also review some of the more commonly used methods for studying the physiological mechanisms involved in water balance and thermoregulation, and the influence of dehydration on these mechanisms.

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

PubMed

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.

Do sex, body size and reproductive condition influence the thermal preferences of a large lizard? A study in Tupinambis merianae.

PubMed

Cecchetto, Nicolas Rodolfo; Naretto, Sergio

2015-10-01

Body temperature is a key factor in physiological processes, influencing lizard performances; and life history traits are expected to generate variability of thermal preferences in different individuals. Gender, body size and reproductive condition may impose specific requirements on preferred body temperatures. If these three factors have different physiological functions and thermal requirements, then the preferred temperature may represent a compromise that optimizes these physiological functions. Therefore, the body temperatures that lizards select in a controlled environment may reflect a temperature that maximizes their physiological needs. The tegu lizard Tupinambis merianae is one of the largest lizards in South America and has wide ontogenetic variation in body size and sexual dimorphism. In the present study we evaluate intraspecific variability of thermal preferences of T. merianae. We determined the selected body temperature and the rate at which males and females attain their selected temperature, in relation to body size and reproductive condition. We also compared the behavior in the thermal gradient between males and females and between reproductive condition of individuals. Our study show that T. merianae selected body temperature within a narrow range of temperatures variation in the laboratory thermal gradient, with 36.24±1.49°C being the preferred temperature. We observed no significant differences between sex, body size and reproductive condition in thermal preferences. Accordingly, we suggest that the evaluated categories of T. merianae have similar thermal requirements. Males showed higher rates to obtain heat than females and reproductive females, higher rates than non-reproductive ones females. Moreover, males and reproductive females showed a more dynamic behavior in the thermal gradient. Therefore, even though they achieve the same selected temperature, they do it differentially. Copyright © 2015 Elsevier Ltd. All rights reserved.

Different phase delays of peripheral input to primate motor cortex and spinal cord promote cancellation at physiological tremor frequencies.

PubMed

Koželj, Saša; Baker, Stuart N

2014-05-01

Neurons in the spinal cord and motor cortex (M1) are partially phase-locked to cycles of physiological tremor, but with opposite phases. Convergence of spinal and cortical activity onto motoneurons may thus produce phase cancellation and a reduction in tremor amplitude. The mechanisms underlying this phase difference are unknown. We investigated coherence between spinal and M1 activity with sensory input. In two anesthetized monkeys, we electrically stimulated the medial, ulnar, deep radial, and superficial radial nerves; stimuli were timed as independent Poisson processes (rate 10 Hz). Single units were recorded from M1 (147 cells) or cervical spinal cord (61 cells). Ninety M1 cells were antidromically identified as pyramidal tract neurons (PTNs); M1 neurons were additionally classified according to M1 subdivision (rostral/caudal, M1r/c). Spike-stimulus coherence analysis revealed significant coupling over a broad range of frequencies, with the strongest coherence at <50 Hz. Delays implied by the slope of the coherence phase-frequency relationship were greater than the response onset latency, reflecting the importance of late response components for the transmission of oscillatory inputs. The spike-stimulus coherence phase over the 6-13 Hz physiological tremor band differed significantly between M1 and spinal cells (phase differences relative to the cord of 2.72 ± 0.29 and 1.72 ± 0.37 radians for PTNs from M1c and M1r, respectively). We conclude that different phases of the response to peripheral input could partially underlie antiphase M1 and spinal cord activity during motor behavior. The coordinated action of spinal and cortical feedback will act to reduce tremulous oscillations, possibly improving the overall stability and precision of motor control. Copyright © 2014 the American Physiological Society.

Different profiles of decision making and physiology under varying levels of stress in trained military personnel.

PubMed

Gamble, Katherine R; Vettel, Jean M; Patton, Debra J; Eddy, Marianna D; Caroline Davis, F; Garcia, Javier O; Spangler, Derek P; Thayer, Julian F; Brooks, Justin R

2018-03-23

Decision making is one of the most vital processes we use every day, ranging from mundane decisions about what to eat to life-threatening choices such as how to avoid a car collision. Thus, the context in which our decisions are made is critical, and our physiology enables adaptive responses that account for how environmental stress influences our performance. The relationship between stress and decision making can additionally be affected by one's expertise in making decisions in high-threat environments, where experts can develop an adaptive response that mitigates the negative impacts of stress. In the present study, 26 male military personnel made friend/foe discriminations in an environment where we manipulated the level of stress. In the high-stress condition, participants received a shock when they incorrectly shot a friend or missed shooting a foe; in the low-stress condition, participants received a vibration for an incorrect decision. We characterized performance using signal detection theory to investigate whether a participant changed their decision criterion to avoid making an error. Results showed that under high-stress, participants made more false alarms, mistaking friends as foes, and this co-occurred with increased high frequency heart rate variability. Finally, we examined the relationship between decision making and physiology, and found that participants exhibited adaptive behavioral and physiological profiles under different stress levels. We interpret this adaptive profile as a marker of an expert's ingrained training that does not require top down control, suggesting a way that expert training in high-stress environments helps to buffer negative impacts of stress on performance. Published by Elsevier B.V.

Physiological responses and lipid storage of the coral Lophelia pertusa at varying food density.

PubMed

Baussant, Thierry; Nilsen, Marianne; Ravagnan, Elisa; Westerlund, Stig; Ramanand, Sreerekha

2017-01-01

Despite the importance of the cold-water coral Lophelia pertusa to deep-sea reef ecosystem functioning, current knowledge of key physiological responses to available food resources is scarce. Scenarios with varying food density may help to understand how corals deal with seasonal variations in the dark ocean and might be used to study consequences of anthropogenic activities potentially affecting food availability. Thus, the physiological responses of L. pertusa to varying food (Artemia salina nauplii) concentration, ranging from 20% to 300% of carbon equivalent turned over by basal coral respiration, were investigated. A starvation group was also included. Measurements of respiration, growth, mucus production, and energy reserves (storage fatty acids) were performed at several time intervals over 26 weeks. In general, data showed a stronger effect of experimental time on measured responses, but no significant influence of food density treatment. In starved corals, respiration rate declined to 52% of initial respiration, while skeleton growth rate was maintained at the same rate as Artemia-fed corals throughout the investigation. Mucus production measured as the sum of dissolved organic carbon (DOC) and particulate organic carbon (POC) was also similar across food treatments, but POC production exceeded that of DOC at the highest food density. No marked effect was observed on storage fatty acids. These results confirm that L. pertusa is highly resilient to environmental conditions with suboptimal food densities over a time scale of months. Regulation of several physiological processes, including respiration and mucus production, possibly in combination with an opportunistic feeding strategy, contributed to this tolerance to maintain viable corals. Thus, it appears that L. pertusa is well adapted to life in the deep sea.

Physiological (antioxidant) responses of estuarine fishes to variability in dissolved oxygen.

PubMed

Ross, S W; Dalton, D A; Kramer, S; Christensen, B L

2001-11-01

Cycles of dissolved oxygen (DO) in estuaries can range from anoxia to various levels of supersaturation (200-300%) over short time periods. Aerobic metabolism causes formation of damaging reactive oxygen species (ROS), a process exacerbated by high or low DO. Fish can generate physiological defenses (e.g. antioxidant enzymes) against ROS, however, there are little data tying this to environmental conditions. We investigated physiological defenses generated by estuarine fishes in response to high DO and various DO cycles. We hypothesized that chemical defenses and/or oxidative damage are related to patterns of DO supersaturation. Specific activities of antioxidants in fish tissues should be positively correlated with increasing levels of DO, if high DO levels are physiologically stressful. We caged common benthic fishes (longjaw mudsucker, Gillichthys mirabilis, and staghorn sculpin, Leptocottus armatus, in CA and spot, Leiostomus xanthurus and pinfish, Lagodon rhomboides, in NC) during summer 1998 in two estuarine sites in southern North Carolina and two in central California. At each site a water quality meter measured bottom DO, salinity, temperature, depth, pH and turbidity at 30 min intervals throughout the study. These sites exhibited a wide variety of dissolved oxygen patterns. After 2 weeks in the cages, fish gills and livers were analyzed for antioxidant enzymes (glutathione peroxidase, catalase and superoxide dismutase) and the metabolite glutathione. All fish exhibited antioxidant enzyme activity. There was a significant site-dependent effect on all enzyme activities at the NC sites, with the most activity at the site with the highest DO cycling and the most DO supersaturation. There was a trend towards higher enzyme activities under high DO levels at the CA sites.

Promoting the translation of intentions into action by implementation intentions: behavioral effects and physiological correlates

PubMed Central

Wieber, Frank; Thürmer, J. Lukas; Gollwitzer, Peter M.

2015-01-01

The present review addresses the physiological correlates of planning effects on behavior. Although intentions to act qualify as predictors of behavior, accumulated evidence indicates that there is a substantial gap between even strong intentions and subsequent action. One effective strategy to reduce this intention–behavior gap is the formation of implementation intentions that specify when, where, and how to act on a given goal in an if-then format (“If I encounter situation Y, then I will initiate action Z!”). It has been proposed that implementation intentions render the mental representation of the situation highly accessible and establish a strong associative link between the mental representations of the situation and the action. These process assumptions have been examined in behavioral research, and in physiological research, a field that has begun to investigate the temporal dynamics of and brain areas involved in implementation intention effects. In the present review, we first summarize studies on the cognitive processes that are central to the strategic automation of action control by implementation intentions. We then examine studies involving critical samples with impaired self-regulation. Lastly, we review studies that have applied physiological measures such as heart rate, cortisol level, and eye movement, as well as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) studies on the neural correlates of implementation intention effects. In support of the assumed processes, implementation intentions increased goal attainment in studies on cognitive processes and in critical samples, modulated brain waves related to perceptual and decision processes, and generated less activity in brain areas associated with effortful action control. In our discussion, we reflect on the status quo of physiological research on implementation intentions, methodological and conceptual issues, related research, and propose future directions. PMID:26236214

Chronic alcoholism: insights from neurophysiology.

PubMed

Campanella, S; Petit, G; Maurage, P; Kornreich, C; Verbanck, P; Noël, X

2009-01-01

Increasing knowledge of the anatomical structures and cellular processes underlying psychiatric disorders may help bridge the gap between clinical signs and basic physiological processes. Accordingly, considerable insight has been gained in recent years into a common psychiatric condition, i.e., chronic alcoholism. We reviewed various physiological parameters that are altered in chronic alcoholic patients compared to healthy individuals--continuous electroencephalogram, oculomotor measures, cognitive event-related potentials and event-related oscillations--to identify links between these physiological parameters, altered cognitive processes and specific clinical symptoms. Alcoholic patients display: (1) high beta and theta power in the resting electroencephalogram, suggesting hyperarousal of their central nervous system; (2) abnormalities in smooth pursuit eye movements, in saccadic inhibition during antisaccade tasks, and in prepulse inhibition, suggesting disturbed attention modulation and abnormal patterns of prefrontal activation that may stem from the same prefrontal "inhibitory" cortical dysfunction; (3) decreased amplitude for cognitive event-related potentials situated along the continuum of information-processing, suggesting that alcoholism is associated with neurophysiological deficits at the level of the sensory cortex and not only disturbances involving associative cortices and limbic structures; and (4) decreased theta, gamma and delta oscillations, suggesting cognitive disinhibition at a functional level. The heterogeneity of alcoholic disorders in terms of symptomatology, course and outcome is the result of various pathophysiological processes that physiological parameters may help to define. These alterations may be related to precise cognitive processes that could be easily monitored neurophysiologically in order to create more homogeneous subgroups of alcoholic individuals.