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Sample records for pulsus paradoxus physiology

  1. Medical image of the week: pulsus paradoxus

    Directory of Open Access Journals (Sweden)

    Thao C

    2015-09-01

    Full Text Available A 75 year-old man was admitted for suspected septic shock and acute renal failure requiring hemodialysis. He did not required mechanical ventilation. An arterial line was placed and he was found to have pulsus paradoxus (Figure 1. A transthoracic echocardiogram showed early right atrial diastolic collapse consistent with cardiac tamponade and he underwent a pericardial window. Pulsus paradoxus is the drop in more than 10 mm Hg of systolic pressure during the inspiratory phase (1. Causes of pulsus paradoxus include cardiac tamponade, constrictive pericarditis, severe asthma and chronic obstructive pulmonary disease, restrictive cardiomyopathy, tension pneumothorax, tracheal compression, and circulatory shock (2. With early recognition of this clinical sign, prompt treatment of the underlying etiology can produce a more desirable outcome.

  2. Noninvasive assessment of asthma severity using pulse oximeter plethysmograph estimate of pulsus paradoxus physiology

    Directory of Open Access Journals (Sweden)

    Jenkins Cathy A

    2010-03-01

    Full Text Available Abstract Background Pulsus paradoxus estimated by dynamic change in area under the oximeter plethysmograph waveform (PEP might provide a measure of acute asthma severity. Our primary objective was to determine how well PEP correlates with forced expiratory volume in 1-second (%FEV1 (criterion validity and change of %FEV1 (responsiveness during treatment in pediatric patients with acute asthma exacerbations. Methods We prospectively studied subjects 5 to 17 years of age with asthma exacerbations. PEP, %FEV1, airway resistance and accessory muscle use were recorded at baseline and at 2 and 4 hours after initiation of corticosteroid and bronchodilator treatments. Statistical associations were tested with Pearson or Spearman rank correlations, logistic regression using generalized estimating equations, or Wilcoxon rank sum tests. Results We studied 219 subjects (median age 9 years; male 62%; African-American 56%. Correlation of PEP with %FEV1 demonstrated criterion validity (r = - 0.44, 95% confidence interval [CI], - 0.56 to - 0.30 and responsiveness at 2 hours (r = - 0.31, 95% CI, - 0.50 to - 0.09 and 4 hours (r = - 0.38, 95% CI, - 0.62 to - 0.07. PEP also correlated with airway resistance at baseline (r = 0.28 for ages 5 to 10; r = 0.45 for ages 10 to 17, but not with change over time. PEP was associated with accessory muscle use (OR 1.16, 95% CI, 1.11 to 1.21, P Conclusions PEP demonstrates criterion validity and responsiveness in correlations with %FEV1. PEP correlates with airway resistance at baseline and is associated with accessory muscle use at baseline and at 2 and 4 hours after initiation of treatment. Incorporation of this technology into contemporary pulse oximeters may provide clinicians improved parameters with which to make clinical assessments of asthma severity and response to treatment, particularly in patients who cannot perform spirometry because of young age or severity of illness. It might also allow for earlier recognition

  3. Mechanism study of pulsus paradoxus using mechanical models.

    Directory of Open Access Journals (Sweden)

    Chang-yang Xing

    Full Text Available Pulsus paradoxus is an exaggeration of the normal inspiratory decrease in systolic blood pressure. Despite a century of attempts to explain this sign consensus is still lacking. To solve the controversy and reveal the exact mechanism, we reexamined the characteristic anatomic arrangement of the circulation system in the chest and designed these mechanical models based on related hydromechanic principles. Model 1 was designed to observe the primary influence of respiratory intrathoracic pressure change (RIPC on systemic and pulmonary venous return systems (SVR and PVR respectively. Model 2, as an equivalent mechanical model of septal swing, was to study the secondary influence of RIPC on the motion of the interventriclar septum (IVS, which might be the direct cause for pulsus paradoxus. Model 1 demonstrated that the simulated RIPC had different influence on the simulated SVR and PVR. It increased the volume of the simulated right ventricle (SRV when the internal pressure was kept constant (8.16 cmH2O, while it had the opposite effect on PVR. Model 2 revealed the three major factors determining the respiratory displacement of IVS in normal and different pathophysiological conditions: the magnitude of RIPC, the pressure difference between the two ventricles and the intrapericardial pressure. Our models demonstrate that the different anatomical arrangement of the two venous return systems leads to a different effect of RIPC on right and left ventricles, and thus a pressure gradient across IVS that tends to shift IVS left- and rightwards. When the leftward displacement of IVS reaches a considerable amplitude in some pathologic condition such as cardiac tamponade, the pulsus paradoxus occurs.

  4. Using a human cardiovascular-respiratory model to characterize cardiac tamponade and pulsus paradoxus

    Science.gov (United States)

    Ramachandran, Deepa; Luo, Chuan; Ma, Tony S; Clark, John W

    2009-01-01

    competition for fixed filling space. We find that simulating active septal contraction is important in modeling ventricular interaction. The model predicts increased arterio-venous CO2 due to hypoperfusion, and we explore implications of respiratory pattern in tamponade. Conclusion Our modeling study of cardiac tamponade dissects the roles played by septal motion, atrioventricular and right-left ventricular interactions, pulmonary blood pooling, and the depth of respiration. The study fully describes the physiological basis of pulsus paradoxus. Our detailed analysis provides biophysically-based insights helpful for future experimental and clinical study of cardiac tamponade and related pericardial diseases. PMID:19656411

  5. Biventricular Pulsus Alternans

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    Param Vidwan

    2009-01-01

    Full Text Available Pulsus alternans is a rare hemodynamic condition characterized by beat-to-beat variability in systolic pressure. It is attributed to variations in stroke volume with alternate cardiac cycles and is typically seen in patients with advanced myopathic conditions. Left ventricular pulsus alternans is rare, and right ventricular pulsus alternans is even less common. There are only a few reports of biventricular pulsus alternans. We report the case of a 62-year-old female with a recent anterior wall myocardial infarction who had biventricular pulsus alternans at the time of cardiac catheterization.

  6. Coordinated surface activities in Variovorax paradoxus EPS

    Directory of Open Access Journals (Sweden)

    Gregory Glenn A

    2009-06-01

    with methionine, arginine, or tyrosine. Large effects of mineral content on swarming were seen with tyrosine and methionine as nitrogen sources. Biofilms form readily under various culture circumstances, and show wide variance in structure under different conditions. The amount of biofilm as measured by crystal violet retention was dependent on carbon source, but not nitrogen source. Filamentous growth in the biofilm depends on shear stress, and is enhanced by continuous input of nutrients in chemostat culture. Conclusion Our studies have established that the beta-proteobacterium Variovorax paradoxus displays a number of distinct physiologies when grown on surfaces, indicative of a complex response to several growth parameters. We have identified a number of factors that drive sessile and motile surface phenotypes. This work forms a basis for future studies using this genetically tractable soil bacterium to study the regulation of microbial development on surfaces.

  7. Coordinated surface activities in Variovorax paradoxus EPS.

    Science.gov (United States)

    Jamieson, W David; Pehl, Michael J; Gregory, Glenn A; Orwin, Paul M

    2009-06-12

    effects of mineral content on swarming were seen with tyrosine and methionine as nitrogen sources. Biofilms form readily under various culture circumstances, and show wide variance in structure under different conditions. The amount of biofilm as measured by crystal violet retention was dependent on carbon source, but not nitrogen source. Filamentous growth in the biofilm depends on shear stress, and is enhanced by continuous input of nutrients in chemostat culture. Our studies have established that the beta-proteobacterium Variovorax paradoxus displays a number of distinct physiologies when grown on surfaces, indicative of a complex response to several growth parameters. We have identified a number of factors that drive sessile and motile surface phenotypes. This work forms a basis for future studies using this genetically tractable soil bacterium to study the regulation of microbial development on surfaces.

  8. Pulsus Group, the Canadian Association of Gastroenterology and CDDW

    Directory of Open Access Journals (Sweden)

    2004-01-01

    Full Text Available At the recent Canadian Digestive Diseases Week in Banff, Alberta, the third annual Dr ABR Thomson - Dr CN Williams Award was presented to Dr Krikor Kichian. This Award was initiated in 2002 by Pulsus Group in honour of Drs Alan Thomson and Noel Williams, the founding Co- Editors-in-Chief of The Canadian Journal of Gastroenterology, who served from 1987 to 2000. Robert Kalina, publisher of The Canadian Journal of Gastroenterology, invited Dr Williams to present the award to Dr Kichian.

  9. Final Critical Habitat for the Pecos Sunflower (Helianthus paradoxus)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To provide the user with a general idea of areas where final critical habitat for Pecos Sunflower (Helianthus paradoxus) occur. The geographic extent includes...

  10. Cultural Characteristics of Shimizuomyces paradoxus Collected from Korea.

    Science.gov (United States)

    Sung, Gi-Ho; Shrestha, Bhushan; Park, Ki-Byung; Sung, Jae-Mo

    2010-09-01

    This study investigated the cultural characteristics of Shimizuomyces paradoxus in different nutritional and environmental conditions. The highest mycelial growth was observed in Schizophyllum (mushroom) genetics complete medium plus yeast extract agar medium, and the optimal temperature and pH were 25℃ and pH 8.0, respectively. The optimal carbon and nitrogen sources were 1% dextrose and 1% peptone in agar. However, in liquid culture the highest dry mycelium weight was found for the potato dextrose agar and potato sucrose agar broths. The optimum inoculum size was five mycelial discs (5 mm) per 100 mL of broth, and the optimum liquid culture period was 25 days. This is the first ever report of S. paradoxus cultural characteristics.

  11. Cultural Characteristics of Shimizuomyces paradoxus Collected from Korea

    OpenAIRE

    2010-01-01

    This study investigated the cultural characteristics of Shimizuomyces paradoxus in different nutritional and environmental conditions. The highest mycelial growth was observed in Schizophyllum (mushroom) genetics complete medium plus yeast extract agar medium, and the optimal temperature and pH were 25℃ and pH 8.0, respectively. The optimal carbon and nitrogen sources were 1% dextrose and 1% peptone in agar. However, in liquid culture the highest dry mycelium weight was found for the potato d...

  12. Point-of-Care Diagnosis of Cardiac Tamponade Identified by the Flow Velocity Paradoxus.

    Science.gov (United States)

    Shyy, William; Knight, Roneesha S; Kornblith, Aaron; Teismann, Nathan A

    2017-05-15

    The presentation of cardiac tamponade is a spectrum from occult to extreme. The clinical history, physical exam, electrocardiogram, and radiographic findings of tamponade have poor sensitivities and even worse specificities. We use a clinical scenario to demonstrate how point-of-care cardiac ultrasound can diagnose impending cardiac tamponade in a clinically stable patient. The ultrasound finding we recommend is the flow velocity paradoxus, in which respiratory variation causes significant changes in transvalvular inflow velocities, which are exaggerated when tamponade is present. The management of a pericardial effusion depends on its physiologic effect, and point-of-care ultrasound directly measures that effect and expedites patient care. © 2017 by the American Institute of Ultrasound in Medicine.

  13. Multiple impacts of the plant growth-promoting rhizobacterium Variovorax paradoxus 5C-2 on nutrient and ABA relations of Pisum sativum

    OpenAIRE

    Jiang, Fan; Chen, Lin; Belimov, Andrey A; Shaposhnikov, Alexander I.; Gong, Fan; Meng, Xu; Hartung, Wolfram; Jeschke, Dieter W.; Davies, William J.; Dodd, Ian C.

    2012-01-01

    Resolving the physiological mechanisms by which rhizobacteria enhance plant growth is difficult, since many such bacteria contain multiple plant growth-promoting properties. To understand further how the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCd)-containing rhizobacterium Variovorax paradoxus 5C-2 affects plant growth, the flows and partitioning of mineral nutrients and abscisic acid (ABA) and ABA metabolism were studied in pea (Pisum sativum) plants following rhizosphere bacter...

  14. The interaction of Saccharomyces paradoxus with its natural competitors on oak bark.

    Science.gov (United States)

    Kowallik, Vienna; Miller, Eric; Greig, Duncan

    2015-04-01

    The natural history of the model yeast Saccharomyces cerevisiae is poorly understood and confounded by domestication. In nature, S. cerevisiae and its undomesticated relative S. paradoxus are usually found on the bark of oak trees, a habitat very different from wine or other human fermentations. It is unclear whether the oak trees are really the primary habitat for wild yeast, or whether this apparent association is due to biased sampling. We use culturing and high-throughput environmental sequencing to show that S. paradoxus is a very rare member of the oak bark microbial community. We find that S. paradoxus can grow well on sterile medium made from oak bark, but that its growth is strongly suppressed when the other members of the community are present. We purified a set of twelve common fungal and bacterial species from the oak bark community and tested how each affected the growth of S. paradoxus in direct competition on oak bark medium at summer and winter temperatures, identifying both positive and negative interactions. One Pseudomonas species produces a diffusible toxin that suppresses S. paradoxus as effectively as either the whole set of twelve species together or the complete community present in nonsterilized oak medium. Conversely, one of the twelve species, Mucilaginibacter sp., had the opposite effect and promoted S. paradoxus growth at low temperatures. We conclude that, in its natural oak tree habitat, S. paradoxus is a rare species whose success depends on the much more abundant microbial species surrounding it.

  15. Biochemical Properties and Crystal Structure of a β-Phenylalanine Aminotransferase from Variovorax paradoxus

    NARCIS (Netherlands)

    Crismaru, Ciprian G.; Wybenga, Gjalt G.; Szymanski, Wiktor; Wijma, Hein J.; Wu, Bian; Bartsch, Sebastian; de Wildeman, Stefaan; Poelarends, Gerrit J.; Feringa, Ben L.; Dijkstra, Bauke; Janssen, Dick B.

    2013-01-01

    By selective enrichment, we isolated a bacterium that can use beta-phenylalanine as a sole nitrogen source. It was identified by 16S rRNA gene sequencing as a strain of Variovorax paradoxus. Enzyme assays revealed an aminotransferase activity. Partial genome sequencing and screening of a cosmid DNA

  16. A new record for Limnobatodes paradoxus Hussey, 1925 from Guyana (Hemiptera: Heteroptera: Hydrometridae: Limnobatodinae).

    Science.gov (United States)

    Cianferoni, Fabio

    2014-06-04

    Limnobatodes paradoxus Hussey, 1925 is a primitive hydrometrid, described from a single female specimen collected in 1923 at Tela, Honduras (Hussey 1925). Following the original description, very few records of this species have been reported in literature, and locality indications are not detailed: Brazil (Cobben 1968), Peru (Andersen 1977), and French Guiana (Polhemus & Polhemus 1995). Andersen (1977, 1982) quoted "British Honduras" [= Belize] instead of Honduras, and this mistake was subsequently repeated by Schuh and Slater (1995) (see Moreira, 2014). This taxon was not listed by Heckman (2011) in his monograph on the Heteroptera of South America. Excellent illustrations of this species, in comparison with those of other Heteroptera, have been provided by several authors (cf. Hussey 1925; Cobben 1968, 1978; Andersen 1977, 1982). Nothing is known about the habitat and life history of Limnobatodes paradoxus (Andersen 1977; Polhemus & Polhemus 1995).

  17. Exploring the northern limit of the distribution of Saccharomyces cerevisiae and Saccharomyces paradoxus in North America.

    Science.gov (United States)

    Charron, Guillaume; Leducq, Jean-Baptiste; Bertin, Chloé; Dubé, Alexandre K; Landry, Christian R

    2014-03-01

    We examined the northern limit of Saccharomyces cerevisiae and Saccharomyces paradoxus in northeast America. We collected 876 natural samples at 29 sites and applied enrichment methods for the isolation of mesophilic yeasts. We uncovered a large diversity of yeasts, in some cases, associated with specific substrates. Sequencing of the ITS1, 5.8S and ITS2 loci allowed to assign 226 yeast strains at the species level, including 41 S. paradoxus strains. Our intensive sampling suggests that if present, S. cerevisiae is rare at these northern latitudes. Our sampling efforts spread across several months of the year revealed that successful sampling increases throughout the summer and diminishes significantly at the beginning of the fall. The data obtained on the ecological context of yeasts corroborate what was previously reported on Pichiaceae, Saccharomycodaceae, Debaryomycetaceae and Phaffomycetaceae yeast families. We identified 24 yeast isolates that could not be assigned to any known species and that may be of taxonomic, medical, or biotechnological importance. Our study reports new data on the taxonomic diversity of yeasts and new resources for studying the evolution and ecology of S. paradoxus.

  18. Physiology

    Science.gov (United States)

    Kay, Ian

    2008-01-01

    Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

  19. Multiple impacts of the plant growth-promoting rhizobacterium Variovorax paradoxus 5C-2 on nutrient and ABA relations of Pisum sativum.

    Science.gov (United States)

    Jiang, Fan; Chen, Lin; Belimov, Andrey A; Shaposhnikov, Alexander I; Gong, Fan; Meng, Xu; Hartung, Wolfram; Jeschke, Dieter W; Davies, William J; Dodd, Ian C

    2012-11-01

    Resolving the physiological mechanisms by which rhizobacteria enhance plant growth is difficult, since many such bacteria contain multiple plant growth-promoting properties. To understand further how the 1-aminocyclopropane-1-carboxylate (ACC) deaminase (ACCd)-containing rhizobacterium Variovorax paradoxus 5C-2 affects plant growth, the flows and partitioning of mineral nutrients and abscisic acid (ABA) and ABA metabolism were studied in pea (Pisum sativum) plants following rhizosphere bacterial inoculation. Although root architecture was not affected, inoculation increased root and shoot biomass, and stomatal conductance, by 20, 15, and 24%, respectively, and increased N, P, K, Ca, and Mg uptake by 16, 81, 50, 46, and 58%, respectively. P deposition in inoculated plant roots was 4.9 times higher than that in uninoculated controls. Rhizobacterial inoculation increased root to shoot xylem flows and shoot to root phloem flows of K by 1.8- and 2.1-fold, respectively. In control plants, major sinks for K deposition were the roots and upper shoot (43% and 49% of total uptake, respectively), while rhizobacterial inoculation increased K distribution to the lower shoot at the expense of other compartments (xylem, phloem, and upper shoot). Despite being unable to metabolize ABA in vitro, V. paradoxus 5C-2 decreased root ABA concentrations and accumulation by 40-60%. Although inoculation decreased xylem ABA flows, phloem ABA flows increased. Whether bacterial ACCd attenuates root to shoot ABA signalling requires further investigation, since ABA is critical to maintain growth of droughted plants, and ACCd-containing organisms have been advocated as a means of minimizing growth inhibition of plants in drying soil.

  20. Chemical Strategies of the Beetle Metoecus Paradoxus, Social Parasite of the Wasp Vespula Vulgaris.

    Science.gov (United States)

    Van Oystaeyen, Annette; van Zweden, Jelle S; Huyghe, Hilde; Drijfhout, Falko; Bonckaert, Wim; Wenseleers, Tom

    2015-12-01

    The parasitoid beetle Metoecus paradoxus frequently parasitizes colonies of the common wasp, Vespula vulgaris. It penetrates a host colony as a larva that attaches itself onto a foraging wasp's body and, once inside the nest, it feeds on a wasp larva inside a brood cell and then pupates. Avoiding detection by the wasp host is crucial when the beetle emerges. Here, we tested whether adult M. paradoxus beetles avoid detection by mimicking the cuticular hydrocarbon profile of their host. The beetles appear to be chemically adapted to their main host species, the common wasp, because they share more hydrocarbon compounds with it than they do with the related German wasp, V. germanica. In addition, aggression tests showed that adult beetles were attacked less by common wasp workers than by German wasp workers. Our results further indicated that the host-specific compounds were, at least partially, produced through recycling of the prey's hydrocarbons, and were not acquired through contact with the adult host. Moreover, the chemical profile of the beetles shows overproduction of the wasp queen pheromone, nonacosane (n-C29), suggesting that beetles might mimic the queen's pheromonal bouquet.

  1. Selection of Variovorax paradoxus-like bacteria in the mycosphere and the role of fungal-released compounds

    NARCIS (Netherlands)

    Boersma, F.G.H.; Otten, Renee; Warmink, J.A.; Nazir, R.; van Elsas, J.D.

    2010-01-01

    At two occasions (2004 and 2006), a similar cluster of culturable bacteria was found to be selected in the mycosphere of the basidiomycetous fungus Laccaria proximo (Agaricales, Tricholomataceae) in the field. The bacteria, identified as related to Variovorax paradoxus, comprised 7.3-9% of the total

  2. Selection of Variovorax paradoxus-like bacteria in the mycosphere and the role of fungal-released compounds

    NARCIS (Netherlands)

    Boersma, F.G.H.; Otten, Renee; Warmink, J.A.; Nazir, R.; van Elsas, J.D.

    2010-01-01

    At two occasions (2004 and 2006), a similar cluster of culturable bacteria was found to be selected in the mycosphere of the basidiomycetous fungus Laccaria proximo (Agaricales, Tricholomataceae) in the field. The bacteria, identified as related to Variovorax paradoxus, comprised 7.3-9% of the total

  3. Biochemical properties and crystal structure of a β-phenylalanine aminotransferase from Variovorax paradoxus.

    Science.gov (United States)

    Crismaru, Ciprian G; Wybenga, Gjalt G; Szymanski, Wiktor; Wijma, Hein J; Wu, Bian; Bartsch, Sebastian; de Wildeman, Stefaan; Poelarends, Gerrit J; Feringa, Ben L; Dijkstra, Bauke W; Janssen, Dick B

    2013-01-01

    By selective enrichment, we isolated a bacterium that can use β-phenylalanine as a sole nitrogen source. It was identified by 16S rRNA gene sequencing as a strain of Variovorax paradoxus. Enzyme assays revealed an aminotransferase activity. Partial genome sequencing and screening of a cosmid DNA library resulted in the identification of a 1,302-bp aminotransferase gene, which encodes a 46,416-Da protein. The gene was cloned and overexpressed in Escherichia coli. The recombinant enzyme was purified and showed a specific activity of 17.5 U mg(-1) for (S)-β-phenylalanine at 30°C and 33 U mg(-1) at the optimum temperature of 55°C. The β-specific aminotransferase exhibits a broad substrate range, accepting ortho-, meta-, and para-substituted β-phenylalanine derivatives as amino donors and 2-oxoglutarate and pyruvate as amino acceptors. The enzyme is highly enantioselective toward (S)-β-phenylalanine (enantioselectivity [E], >100) and derivatives thereof with different substituents on the phenyl ring, allowing the kinetic resolution of various racemic β-amino acids to yield (R)-β-amino acids with >95% enantiomeric excess (ee). The crystal structures of the holoenzyme and of the enzyme in complex with the inhibitor 2-aminooxyacetate revealed structural similarity to the β-phenylalanine aminotransferase from Mesorhizobium sp. strain LUK. The crystal structure was used to rationalize the stereo- and regioselectivity of V. paradoxus aminotransferase and to define a sequence motif with which new aromatic β-amino acid-converting aminotransferases may be identified.

  4. Gains and Losses of Transcription Factor Binding Sites in Saccharomyces cerevisiae and Saccharomyces paradoxus.

    Science.gov (United States)

    Schaefke, Bernhard; Wang, Tzi-Yuan; Wang, Chuen-Yi; Li, Wen-Hsiung

    2015-07-27

    Gene expression evolution occurs through changes in cis- or trans-regulatory elements or both. Interactions between transcription factors (TFs) and their binding sites (TFBSs) constitute one of the most important points where these two regulatory components intersect. In this study, we investigated the evolution of TFBSs in the promoter regions of different Saccharomyces strains and species. We divided the promoter of a gene into the proximal region and the distal region, which are defined, respectively, as the 200-bp region upstream of the transcription starting site and as the 200-bp region upstream of the proximal region. We found that the predicted TFBSs in the proximal promoter regions tend to be evolutionarily more conserved than those in the distal promoter regions. Additionally, Saccharomyces cerevisiae strains used in the fermentation of alcoholic drinks have experienced more TFBS losses than gains compared with strains from other environments (wild strains, laboratory strains, and clinical strains). We also showed that differences in TFBSs correlate with the cis component of gene expression evolution between species (comparing S. cerevisiae and its sister species Saccharomyces paradoxus) and within species (comparing two closely related S. cerevisiae strains).

  5. Idiopathic pericardial effusion in 2 year old labrador managed with ...

    African Journals Online (AJOL)

    HP USER

    intolerance. At presentation, rectal temperature was 38.5oC, pulse rate was135 beats per minute (but weak). ... The heart sound was muffled and pulsus paradoxus was very mild. ... patient returned to gradual exercise during hospitalization.

  6. Spawning patterns of shallow-water hake (Merluccius capensis) and deep-water hake (M. paradoxus) in the Benguela Current Large Marine Ecosystem inferred from gonadosomatic indices

    DEFF Research Database (Denmark)

    Jansen, Teunis; Kainge, Paulus Inekela; Singh, Larvika

    2015-01-01

    . In the southern Benguela, peaks in the proportions of spawning M. capensis were observed in two areas off the South African West Coast (31.0-32.5°S and 34.5-36.0°S), whereas spawning females off the South African South Coast (east of 20°E) appeared to be more evenly distributed in space. Seasonality differed....... In the northern Benguela, spawning M. paradoxus were observed as far north as 25°S in August. The proportion of spawning females peaked between 34.5°S and 36.5°S off the West Coast, and between 23.0°E and 26.5 °E off the South Coast. It was suggested that M. paradoxus spawn throughout the year off the South...

  7. [Lipid profile analysis of two species of hake "merluccius capensis and merluccius paradoxus" and its contribution to cardiovascular disease prevention].

    Science.gov (United States)

    Piñeiro Corrales, Guadalupe; Lago Rivero, N; Olivera Fernández, R; Culebras-Fernandez, Jesus M

    2013-01-01

    Introducción: En los últimos 2013s se ha demostrado que los AGPI omega-3 presentan múltiples efectos protectores cardiovasculares. Actualmente, el pescado constituye la principal y la más importante fuente de ácidos grasos Omega-3. Objetivo: Analizar la composición en ácidos grasos en dos especies de merluza, determinar su contenido en ácidos grasos omega-3 y estudiar su aportación en la prevención de enfermedades cardiovasculares. Material y métodos: Se han analizado muestras de dos especies de merluza (Merluccius capensis y Merluccius paradoxus) en su estado natural y congeladas, cocinadas al microondas y muestras hervidas. Se ha estudiado el contenido en humedad, contenido lipídico y el análisis, composición e identificación de ácidos grasos. Resultados: Se observó que el contenido de AGPI w-3 fue mayor que el de AGPI w-6. Los ácidos grasos omega-3 DHA y EPA fueron los más representativos de la familia omega-3, destacando el contenido de DHA en todas lasmuestras analizadas. Asimismo, se ha demostrado la seguridad de los métodos de cocción «microondas» y «hervido» como métodos que aseguran la integridad de los AGPI w-3. Conclusión: Las muestras de merluza analizadas presentan un óptimo perfil lipídico. Su contenido en AGPI w-3 y sus propiedades, hacen que la merluza se distinga como pescado de referencia en dietas cardiosaludables.

  8. The genome of Variovorax paradoxus strain TBEA6 provides new understandings for the catabolism of 3,3'-thiodipropionic acid and hence the production of polythioesters.

    Science.gov (United States)

    Wübbeler, Jan Hendrik; Hiessl, Sebastian; Meinert, Christina; Poehlein, Anja; Schuldes, Jörg; Daniel, Rolf; Steinbüchel, Alexander

    2015-09-10

    The betaproteobacterium Variovorax paradoxus strain TBEA6 is capable of using 3,3'-thiodipropionic acid (TDP) as sole carbon and energy source for growth. This thioether is employed for several industrial applications. It can be applied as precursor for the biotechnical production of polythioesters (PTE), which represent persistent bioplastics. Consequently, the genome of V. paradoxus strain TBEA6 was sequenced. The draft genome sequence comprises approximately 7.2Mbp and 6852 predicted open reading frames. Furthermore, transposon mutagenesis to unravel the catabolism of TDP in strain TBEA6 was performed. Screening of 20,000 mutants mapped the insertions of Tn5::mob in 32 mutants, which all showed no growth with TDP as sole carbon source. Based on the annotated genome sequence together with transposon-induced mutagenesis, defined gene deletions, in silico analyses and comparative genomics, a comprehensive pathway for the catabolism of TDP is proposed: TDP is imported via the tripartite tricarboxcylate transport system and/or the TRAP-type dicarboxylate transport system. The initial cleavage of TDP into 3-hydroxypropionic acid (3HP) and 3-mercaptopropionic acid (3MP), which serves as precursor substrate for PTE synthesis, is most probably performed by the FAD-dependent oxidoreductase Fox. 3HP is presumably catabolized via malonate semialdehyde, whereas 3MP is oxygenated by the 3MP-dioxygenase Mdo yielding 3-sulfinopropionic acid (3SP). Afterwards, 3SP is linked to coenzyme A. The next step is the abstraction of sulfite by a desulfinase, and the resulting propionyl-CoA enters the central metabolism. Sulfite is oxidized to sulfate by the sulfite-oxidizing enzyme SoeABC and is subsequently excreted by the cells by the sulfate exporter Pse.

  9. Optimization of a Cytochrome-P450-Monooxygenase-1A-Mediated EROD Assay in the Cape Hake Species Merluccius capensis and Merluccius paradoxus (Pisces

    Directory of Open Access Journals (Sweden)

    Louise De Almeida

    2011-01-01

    Full Text Available Cytochrome P450 monooxygenase 1A (CYP1A is induced by several planar toxic compounds, for example, polychlorinated biphenyls (PCBs and the induction of this protein is often measured in terms of CYP1A-mediated 7-ethoxyresorufin-O-deethylase (EROD activity. This study was aimed at developing this assay in the Cape hake species Merluccius capensis and Merluccius paradoxus (considered one stock. Microsomal fractions were obtained from frozen fish liver samples by differential centrifugation. Fluorimetric and spectrophotometric analysis of the EROD assay resulted in the spectrophotometric (at 572 nm detection method being selected, as this method resulted in a lower degree of variability and demonstrated higher reproducibility. The activity in the EROD assay was enhanced in the presence of NADPH, and the addition of dicumarol (phase II enzyme inhibitor to the reaction mixtures prevented the underestimation of this assay by the inhibition of DT-diaphorase. In summary, an EROD assay was established for use in Cape hake species.

  10. Nasal Physiology

    Science.gov (United States)

    ... Caregivers Contact ARS HOME ANATOMY Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy Skull Base Anatomy Virtual Anatomy Disclosure ... Patient Education About this Website Font Size + - Home > ANATOMY > Nasal Physiology Nasal Anatomy Sinus Anatomy Nasal Physiology Nasal Endoscopy ...

  11. Physiological Networks: towards systems physiology

    Science.gov (United States)

    Bartsch, Ronny P.; Bashan, Amir; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

    2012-02-01

    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate new dimensions to the field of systems physiology.

  12. Mathematical physiology

    CERN Document Server

    Sneyd, James

    2009-01-01

    There has been a long history of interaction between mathematics and physiology. This book looks in detail at a wide selection of mathematical models in physiology, showing how physiological problems can be formulated and studied mathematically, and how such models give rise to interesting and challenging mathematical questions. With its coverage of many recent models it gives an overview of the field, while many older models are also discussed, to put the modern work in context. In this second edition the coverage of basic principles has been expanded to include such topics as stochastic differential equations, Markov models and Gibbs free energy, and the selection of models has also been expanded to include some of the basic models of fluid transport, respiration/perfusion, blood diseases, molecular motors, smooth muscle, neuroendrocine cells, the baroreceptor loop, turboglomerular oscillations, blood clotting and the retina. Owing to this extensive coverage, the second edition is published in two volumes. ...

  13. Reproductive physiology

    Science.gov (United States)

    Gee, G.F.; Russman, S.E.; Ellis, David H.; Gee, George F.; Mirande, Claire M.

    1996-01-01

    Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

  14. Exercise physiology

    DEFF Research Database (Denmark)

    Kiens, Bente; Richter, Erik; Wojtaszewski, Jørgen

    2014-01-01

    The passing of Professor Bengt Saltin on September 12, 2014 truly marks the end of an era. As editor of the Journal of Applied Physiology and one of Bengt’s many collaborators and colleagues, I wanted the Journal to celebrate his many seminal contributions by means of an Editorial. Professor Bent...

  15. Occupational physiology

    CERN Document Server

    Toomingas, Allan; Tornqvist, Ewa Wigaeus

    2011-01-01

    In a clear and accessible presentation, Occupational Physiology focuses on important issues in the modern working world. Exploring major public health problems-such as musculoskeletal disorders and stress-this book explains connections between work, well-being, and health based on up-to-date research in the field. It provides useful methods for risk assessment and guidelines on arranging a good working life from the perspective of the working individual, the company, and society as a whole.The book focuses on common, stressful situations in different professions. Reviewing bodily demands and r

  16. Physiological Acoustics

    Science.gov (United States)

    Young, Eric D.

    The analysis of physiological sound in the peripheral auditory system solves three important problems. First, sound energy impinging on the head must be captured and presented to the transduction apparatus in the ear as a suitable mechanical signal; second, this mechanical signal needs to be transduced into a neural representation that can be used by the brain; third, the resulting neural representation needs to be analyzed by central neurons to extract information useful to the animal. This chapter provides an overview of some aspects of the first two of these processes. The description is entirely focused on the mammalian auditory system, primarily on human hearing and on the hearing of a few commonly used laboratory animals (mainly rodents and carnivores). Useful summaries of non-mammalian hearing are available [1]. Because of the large size of the literature, review papers are referenced wherever possible.

  17. Space Physiology within an Exercise Physiology Curriculum

    Science.gov (United States)

    Carter, Jason R.; West, John B.

    2013-01-01

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

  18. Potassium physiology.

    Science.gov (United States)

    Thier, S O

    1986-04-25

    Potassium is the most abundant exchangeable cation in the body. It exists predominantly in the intracellular fluid at concentrations of 140 to 150 meq/liter and in the extracellular fluid at concentrations of 3.5 to 5 meq/liter. The maintenance of the serum potassium concentration is a complex bodily function and results from the balance between intake, excretion, and distribution between intracellular and extracellular space. Ingested potassium is virtually completely absorbed from and minimally excreted through the intestine under nonpathologic circumstances. Renal excretion of potassium, which is the major chronic protective mechanism against abnormalities in potassium balance, depends on filtration, reabsorption, and a highly regulated distal nephron secretory process. Factors regulating potassium secretion include prior potassium intake, intracellular potassium, delivery of sodium chloride and poorly reabsorbable anions to the distal nephron, the urine flow rate, hormones such as aldosterone and beta-catecholamines, and the integrity of the renal tubular cell. The maintenance of distribution between the inside and outside of cells depends on the integrity of the cell membrane and its pumps, osmolality, pH, and the hormones insulin, aldosterone, beta 2-catecholamines, alpha-catecholamines, and prostaglandins. Both distribution across cell membranes and/or renal excretion of potassium may be altered by pharmacologic agents such as diuretics, alpha- and beta-catechol antagonists and agonists, depolarizing agents, and digitalis. Problems with hypokalemia and hyperkalemia can be analyzed on the basis of potassium physiology and pharmacology; proper treatment depends on an accurate analysis.

  19. Análisis del perfil lipídico de dos especies de merluza "Merluccius capensis y Merluccius paradoxus" y su aportación a la prevención de enfermedades cardiovasculares

    Directory of Open Access Journals (Sweden)

    Guadalupe Piñeiro Corrales

    2013-02-01

    Full Text Available Introducción: En los últimos años se ha demostrado que los AGPI omega-3 presentan múltiples efectos protectores cardiovasculares. Actualmente, el pescado constituye la principal y la más importante fuente de ácidos grasos Omega-3. Objetivo: Analizar la composición en ácidos grasos en dos especies de merluza, determinar su contenido en ácidos grasos omega-3 y estudiar su aportación en la prevención de enfermedades cardiovasculares. Material y Métodos: Se han analizado muestras de dos especies de merluza (Merluccius capensis y Merluccius paradoxus en su estado natural y congeladas, cocinadas al microondas y muestras hervidas. Se ha estudiado el contenido en humedad, contenido lipídico y el análisis, composición e identificación de ácidos grasos. Resultados: Se observó que el contenido de AGPI w-3 fue mayor que el de AGPI w-6. Los ácidos grasos omega-3 DHA y EPA fueron los más representativos de la familia omega-3, destacando el contenido de DHA en todas las muestras analizadas. Asimismo, se ha demostrado la seguridad de los métodos de cocción "microondas" y "hervido" como métodos que aseguran la integridad de los AGPI w-3. Conclusión: Las muestras de merluza analizadas presentan un óptimo perfil lipídico. Su contenido en AGPI w-3 y sus propiedades, hacen que la merluza se distinga como pescado de referencia en dietas cardiosaludables.

  20. [Human physiology: kidney].

    Science.gov (United States)

    Natochin, Iu V

    2010-01-01

    The content of human physiology as an independent part of current physiology is discussed. Substantiated is the point that subjects of human physiology are not only special sections of physiology where functions are inherent only in human (physiology of intellectual activity, speech, labor, sport), but also in peculiarities of functions, specificity of regulation of each of physiological systems. By the example of physiology of kidney and water-salt balance there are shown borders of norm, peculiarities of regulation in human, new chapters of renal physiology which have appeared in connection with achievements of molecular physiology.

  1. Physiological effects in aromatherapy

    OpenAIRE

    2004-01-01

    The effects of aromas on humans are divided into physiological and psychological effects. The physiological effect acts directly on the physical organism, the psychological effect acts via the sense of smell or olfactory system, which in turn may cause a physiological effect. This paper reviews on the physiological effects which are used for the evaluation of the effects of aromas. Physiological parameters, i.e. heart rate blood pressure, electrodermal activity, electroencephalogram, slow pot...

  2. Physiological Information Database (PID)

    Science.gov (United States)

    EPA has developed a physiological information database (created using Microsoft ACCESS) intended to be used in PBPK modeling. The database contains physiological parameter values for humans from early childhood through senescence as well as similar data for laboratory animal spec...

  3. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  4. Chewing Over Physiology Integration

    Science.gov (United States)

    Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

    2005-01-01

    An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

  5. Physiological effects in aromatherapy

    Directory of Open Access Journals (Sweden)

    Tapanee Hongratanaworakit

    2004-01-01

    Full Text Available The effects of aromas on humans are divided into physiological and psychological effects. The physiological effect acts directly on the physical organism, the psychological effect acts via the sense of smell or olfactory system, which in turn may cause a physiological effect. This paper reviews on the physiological effects which are used for the evaluation of the effects of aromas. Physiological parameters, i.e. heart rate blood pressure, electrodermal activity, electroencephalogram, slow potential brain waves (contingent negativevariation, and eye blink rate or pupil functions, are used as indices for the measurement of the aroma effects

  6. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  7. Advances in physiological computing

    CERN Document Server

    Fairclough, Stephen H

    2014-01-01

    This edited collection will provide an overview of the field of physiological computing, i.e. the use of physiological signals as input for computer control. It will cover a breadth of current research, from brain-computer interfaces to telemedicine.

  8. Phun Week: Understanding Physiology

    Science.gov (United States)

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

    Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

  9. Physiology of sport.

    Science.gov (United States)

    Maughan, Ron

    2007-07-01

    The elite athlete represents the extreme of the human gene pool, where genetic endowment is developed by an intensive training programme. Sport encompasses many different activities, calling for different physical and mental attributes. Understanding the physiology of exercise provides insights into normal physiological function.

  10. Physiological changes in pregnancy

    OpenAIRE

    SOMA-PILLAY, Priya; Catherine, Nelson-Piercy; Tolppanen, Heli; Mebazaa, Alexandre

    2016-01-01

    Abstract Physiological changes occur in pregnancy to nurture the developing foetus and prepare the mother for labour and delivery. Some of these changes influence normal biochemical values while others may mimic symptoms of medical disease. It is important to differentiate between normal physiological changes and disease pathology. This review highlights the important changes that take place during normal pregnancy.

  11. Fetal cardiovascular physiology.

    Science.gov (United States)

    Rychik, J

    2004-01-01

    The cardiovascular system of the fetus is physiologically different than the adult, mature system. Unique characteristics of the myocardium and specific channels of blood flow differentitate the physiology of the fetus from the newborn. Conditions of increased preload and afterload in the fetus, such as sacrococcygeal teratoma and twin-twin transfusion syndrome, result in unique and complex pathophysiological states. Echocardiography has improved our understanding of human fetal cadiovasvular physiology in the normal and diseased states, and has expanded our capability to more effectively treat these disease processes.

  12. Reproduction, physiology and biochemistry

    Science.gov (United States)

    This chapter summarizes fundamental knowledge and recent discoveries about the reproduction, physiology and biochemistry of plant-parasitic nematodes. Various types of reproduction are reviewed, including sexual reproduction and mitotic and meiotic parthenogenesis. Although much is known about the p...

  13. Physiological mechanisms of prosociality.

    Science.gov (United States)

    Miller, Jonas G

    2017-08-12

    Psychophysiological perspectives can provide unique insights into the nature and motivations of children's prosociality and inform our understanding of individual differences. Here, I review current research on prosociality involving some of the most common physiological measures in developmental psychology, including cortisol, various sympathetic nervous system measures, and high-frequency heart rate variability. The literature has been quite mixed, in part because the link between physiology and prosociality is context-dependent and person-dependent. However, recent advances are refining our understanding of the basic physiological mechanisms of prosociality. Resting physiology that contributes to a balance of regulation and vigilance prepares children to effectively cope with future social challenges, like noticing and attending to the needs of others. Experiencing some arousal is an important aspect of empathy-related responding, but physiological patterns of both heightened and hypoarousal can undermine prosociality. Physiological flexibility in response to others' needs may support emotional and behavioral flexibility important for prosociality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Neuropeptide physiology in helminths.

    Science.gov (United States)

    Mousley, Angela; Novozhilova, Ekaterina; Kimber, Michael J; Day, Tim A

    2010-01-01

    Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete with neuropeptides and there is ample physiological evidence that these neuropeptides control vital aspects of worm biology. In each phyla, the physiological evidence for critical roles for helminth neuropeptides is derived from both parasitic and free-living members. In the nematodes, the intestinal parasite Ascaris suum and the free-living Caenorhabditis elegans have yielded most of the data; in the platyhelminths, the most physiological data has come from the blood fluke Schistosoma mansoni. FMRFamide-like peptides (FLPs) have many varied effects (excitation, relaxation, or a combination) on somatic musculature, reproductive musculature, the pharynx and motor neurons in nematodes. Insulin-like peptides (INSs) play an essential role in nematode dauer formation and other developmental processes. There is also some evidence for a role in somatic muscle control for the somewhat heterogeneous grouping ofpeptides known as neuropeptide-like proteins (NLPs). In platyhelminths, as in nematodes, FLPs have a central role in somatic muscle function. Reports of FLP physiological action in platyhelminths are limited to a potent excitation of the somatic musculature. Platyhelminths are also abundantly endowed with neuropeptide Fs (NPFs), which appear absent from nematodes. There is not yet any data linking platyhelminth NPF to any particular physiological outcome, but this neuropeptide does potently and specifically inhibit cAMP accumulation in schistosomes. In nematodes and platyhelminths, there is an abundance of physiological evidence demonstrating that neuropeptides play critical roles in the biology of both free-living and parasitic helminths. While it is certainly true that there remains a great deal to learn about the biology of neuropeptides in both phyla, physiological evidence presently available points

  15. Human physiology in space

    Science.gov (United States)

    Vernikos, J.

    1996-01-01

    The universality of gravity (1 g) in our daily lives makes it difficult to appreciate its importance in morphology and physiology. Bone and muscle support systems were created, cellular pumps developed, neurons organised and receptors and transducers of gravitational force to biologically relevant signals evolved under 1g gravity. Spaceflight provides the only microgravity environment where systematic experimentation can expand our basic understanding of gravitational physiology and perhaps provide new insights into normal physiology and disease processes. These include the surprising extent of our body's dependence on perceptual information, and understanding the effect and importance of forces generated within the body's weightbearing structures such as muscle and bones. Beyond this exciting prospect is the importance of this work towards opening the solar system for human exploration. Although both appear promising, we are only just beginning to taste what lies ahead.

  16. Circadian physiology of metabolism.

    Science.gov (United States)

    Panda, Satchidananda

    2016-11-25

    A majority of mammalian genes exhibit daily fluctuations in expression levels, making circadian expression rhythms the largest known regulatory network in normal physiology. Cell-autonomous circadian clocks interact with daily light-dark and feeding-fasting cycles to generate approximately 24-hour oscillations in the function of thousands of genes. Circadian expression of secreted molecules and signaling components transmits timing information between cells and tissues. Such intra- and intercellular daily rhythms optimize physiology both by managing energy use and by temporally segregating incompatible processes. Experimental animal models and epidemiological data indicate that chronic circadian rhythm disruption increases the risk of metabolic diseases. Conversely, time-restricted feeding, which imposes daily cycles of feeding and fasting without caloric reduction, sustains robust diurnal rhythms and can alleviate metabolic diseases. These findings highlight an integrative role of circadian rhythms in physiology and offer a new perspective for treating chronic diseases in which metabolic disruption is a hallmark.

  17. Plant Physiology and Development

    DEFF Research Database (Denmark)

    Taiz, Lincoln; Zeiger, Eduardo; Møller, Ian Max

    Physiology and Development. As before, Unit III begins with updated chapters on Cell Walls and Signals and Signal Transduction. The latter chapter has been expanded to include a discussion of major signaling molecules, such as calcium ions and plant hormones. A new, unified chapter entitled Signals from......Throughout its twenty-two year history, the authors of Plant Physiology have continually updated the book to incorporate the latest advances in plant biology and implement pedagogical improvements requested by adopters. This has made Plant Physiology the most authoritative, comprehensive......, and widely used upper-division plant biology textbook. In the Sixth Edition, the Growth and Development section (Unit III) has been reorganized and expanded to present the complete life cycle of seed plants from germination to senescence. In recognition of this enhancement, the text has been renamed Plant...

  18. Cough induced syncope: A hint to cardiac tamponade diagnosis.

    Science.gov (United States)

    Ramirez, Roberto; Lasam, Glenmore

    2017-05-26

    We report a case of a 75-year-old male with history of lung adenocarcinoma who presented with shortness of breath and frequent episodes of cough-induced syncope. A large pericardial effusion was found on echocardiogram suggestive of cardiac tamponade. Pericardiocentesis was done which improved the dyspnea and eventually resolved the syncope. There are only two other cases reported in the literature with cough-induced syncope in the setting of pericardial effusion or cardiac tamponade. Our clinical vignette also highlights the importance of pulsus paradoxus identification in patients with cough induced syncope to rule out cardiac tamponade since this is the most sensitive physical finding for its diagnosis.

  19. Cough induced syncope: A hint to cardiac tamponade diagnosis

    Science.gov (United States)

    Ramirez, Roberto; Lasam, Glenmore

    2017-01-01

    We report a case of a 75-year-old male with history of lung adenocarcinoma who presented with shortness of breath and frequent episodes of cough-induced syncope. A large pericardial effusion was found on echocardiogram suggestive of cardiac tamponade. Pericardiocentesis was done which improved the dyspnea and eventually resolved the syncope. There are only two other cases reported in the literature with cough-induced syncope in the setting of pericardial effusion or cardiac tamponade. Our clinical vignette also highlights the importance of pulsus paradoxus identification in patients with cough induced syncope to rule out cardiac tamponade since this is the most sensitive physical finding for its diagnosis. PMID:28603595

  20. The Face of Physiology

    Directory of Open Access Journals (Sweden)

    Paul White

    2008-10-01

    Full Text Available This article explores the relationship between the physiology of the emotions and the display of character in Victorian Britain. Charles Bell and others had begun to link certain physiological functions, such as respiration, with the expression of feelings such as fear, regarding the heart and other internal organs as instruments by which the emotions were made visible. But a purely functional account of the emotions, which emerged through the development of reflex physiology during the second half of the century, would dramatically alter the nature of feelings and the means of observing them. At the same time, instinctual or acquired sympathy, which had long underpinned the accurate reading of expressions, became a problem to be surmounted by new 'objectively'. Graphic recording instruments measuring a variety of physiological functions and used with increasing frequency in clinical diagnostics became of fundamental importance for tracing the movement of feelings during the period prior to the development of cinematography. They remained, in the form of devices such as the polygraph, a crucial and controversial means of measuring affective states, beneath the potentially deceptive surface of the body.

  1. Starting Physiology: Bioelectrogenesis

    Science.gov (United States)

    Baptista, Vander

    2015-01-01

    From a Cartesian perspective of rational analysis, the electric potential difference across the cell membrane is one of the fundamental concepts for the study of physiology. Unfortunately, undergraduate students often struggle to understand the genesis of this energy gradient, which makes the teaching activity a hard task for the instructor. The…

  2. Physiology of Sleep.

    Science.gov (United States)

    Carley, David W; Farabi, Sarah S

    2016-02-01

    IN BRIEF Far from a simple absence of wakefulness, sleep is an active, regulated, and metabolically distinct state, essential for health and well-being. In this article, the authors review the fundamental anatomy and physiology of sleep and its regulation, with an eye toward interactions between sleep and metabolism.

  3. Integrative Physiology of Fasting.

    Science.gov (United States)

    Secor, Stephen M; Carey, Hannah V

    2016-03-15

    Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting.

  4. Avian reproductive physiology

    Science.gov (United States)

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

    1995-01-01

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

  5. Physiological attributes of triathletes.

    Science.gov (United States)

    Suriano, R; Bishop, D

    2010-05-01

    Triathlons of all distances can be considered endurance events and consist of the individual disciplines of swimming, cycling and running which are generally completed in this sequential order. While it is expected that elite triathletes would possess high values for submaximal and maximal measures of aerobic fitness, little is known about how these values compare with those of single-sport endurance athletes. Earlier reviews, conducted in the 1980s, concluded that triathletes possessed lower V(O2(max)) values than other endurance athletes. An update of comparisons is of interest to determine if the physiological capacities of elite triathletes now reflect those of single-sport athletes or whether these physiological capacities are compromised by the requirement to cross-train for three different disciplines. It was found that although differences in the physiological attributes during swimming, cycling and running are evident among triathletes, those who compete at an international level possess V(O2(max)) values that are indicative of success in endurance-based individual sports. Furthermore, various physiological parameters at submaximal workloads have been used to describe the capacities of these athletes. Only a few studies have reported the lactate threshold among triathletes with the majority of studies reporting the ventilatory threshold. Although observed differences among triathletes for both these submaximal measures are complicated by the various methods used to determine them, the reported values for triathletes are similar to those for trained cyclists and runners. Thus, from the limited data available, it appears that triathletes are able to obtain similar physiological values as single-sport athletes despite dividing their training time among three disciplines.

  6. Tuna comparative physiology.

    Science.gov (United States)

    Graham, Jeffrey B; Dickson, Kathryn A

    2004-11-01

    Thunniform swimming, the capacity to conserve metabolic heat in red muscle and other body regions (regional endothermy), an elevated metabolic rate and other physiological rate functions, and a frequency-modulated cardiac output distinguish tunas from most other fishes. These specializations support continuous, relatively fast swimming by tunas and minimize thermal barriers to habitat exploitation, permitting niche expansion into high latitudes and to ocean depths heretofore regarded as beyond their range.

  7. Clustering and Symbolic Analysis of Cardiovascular Signals: Discovery and Visualization of Medically Relevant Patterns in Long-Term Data Using Limited Prior Knowledge

    Directory of Open Access Journals (Sweden)

    Syed Zeeshan

    2007-01-01

    Full Text Available This paper describes novel fully automated techniques for analyzing large amounts of cardiovascular data. In contrast to traditional medical expert systems our techniques incorporate no a priori knowledge about disease states. This facilitates the discovery of unexpected events. We start by transforming continuous waveform signals into symbolic strings derived directly from the data. Morphological features are used to partition heart beats into clusters by maximizing the dynamic time-warped sequence-aligned separation of clusters. Each cluster is assigned a symbol, and the original signal is replaced by the corresponding sequence of symbols. The symbolization process allows us to shift from the analysis of raw signals to the analysis of sequences of symbols. This discrete representation reduces the amount of data by several orders of magnitude, making the search space for discovering interesting activity more manageable. We describe techniques that operate in this symbolic domain to discover rhythms, transient patterns, abnormal changes in entropy, and clinically significant relationships among multiple streams of physiological data. We tested our techniques on cardiologist-annotated ECG data from forty-eight patients. Our process for labeling heart beats produced results that were consistent with the cardiologist supplied labels 98.6 of the time, and often provided relevant finer-grained distinctions. Our higher level analysis techniques proved effective at identifying clinically relevant activity not only from symbolized ECG streams, but also from multimodal data obtained by symbolizing ECG and other physiological data streams. Using no prior knowledge, our analysis techniques uncovered examples of ventricular bigeminy and trigeminy, ectopic atrial rhythms with aberrant ventricular conduction, paroxysmal atrial tachyarrhythmias, atrial fibrillation, and pulsus paradoxus.

  8. Clustering and Symbolic Analysis of Cardiovascular Signals: Discovery and Visualization of Medically Relevant Patterns in Long-Term Data Using Limited Prior Knowledge

    Directory of Open Access Journals (Sweden)

    Collin Stultz

    2007-01-01

    Full Text Available This paper describes novel fully automated techniques for analyzing large amounts of cardiovascular data. In contrast to traditional medical expert systems our techniques incorporate no a priori knowledge about disease states. This facilitates the discovery of unexpected events. We start by transforming continuous waveform signals into symbolic strings derived directly from the data. Morphological features are used to partition heart beats into clusters by maximizing the dynamic time-warped sequence-aligned separation of clusters. Each cluster is assigned a symbol, and the original signal is replaced by the corresponding sequence of symbols. The symbolization process allows us to shift from the analysis of raw signals to the analysis of sequences of symbols. This discrete representation reduces the amount of data by several orders of magnitude, making the search space for discovering interesting activity more manageable. We describe techniques that operate in this symbolic domain to discover rhythms, transient patterns, abnormal changes in entropy, and clinically significant relationships among multiple streams of physiological data. We tested our techniques on cardiologist-annotated ECG data from forty-eight patients. Our process for labeling heart beats produced results that were consistent with the cardiologist supplied labels 98.6% of the time, and often provided relevant finer-grained distinctions. Our higher level analysis techniques proved effective at identifying clinically relevant activity not only from symbolized ECG streams, but also from multimodal data obtained by symbolizing ECG and other physiological data streams. Using no prior knowledge, our analysis techniques uncovered examples of ventricular bigeminy and trigeminy, ectopic atrial rhythms with aberrant ventricular conduction, paroxysmal atrial tachyarrhythmias, atrial fibrillation, and pulsus paradoxus.

  9. Neonatal cardiovascular physiology.

    Science.gov (United States)

    Hines, Michael H

    2013-11-01

    The pediatric surgeon deals with a large number and variety of congenital defects in neonates that frequently involve early surgical intervention and care. Because the neonatal cardiac physiology is unique, starting with the transition from fetal circulation and including differences in calcium metabolism and myocardial microscopic structure and function, it serves the pediatric surgeon well to have a sound understanding of these principles and how they directly and indirectly affect their plans and treatments. In addition, many patients will have associated congenital heart disease that can also dramatically influence not only the surgical and anesthetic care but also the timing and planning of procedures. Finally, the pediatric surgeon is often called upon to treat conditions and complications associated with complex congenital heart disease such as feeding difficulties, bowel perforations, and malrotation in heterotaxy syndromes. In this article, we will review several unique aspects of neonatal cardiac physiology along with the basic physiology of the major groups of congenital heart disease to better prepare the training and practicing pediatric surgeon for care of these complex and often fragile patients.

  10. Vasogenic shock physiology

    Directory of Open Access Journals (Sweden)

    Sotiria Gkisioti

    2011-01-01

    Full Text Available Sotiria Gkisioti, Spyros D MentzelopoulosDepartment of Intensive Care Medicine, University of Athens Medical School, Evaggelismos General Hospital, Athens, GreeceAbstract: Shock means inadequate tissue perfusion by oxygen-carrying blood. In vasogenic shock, this circulatory failure results from vasodilation and/or vasoplegia. There is vascular hyporeactivity with reduced vascular smooth muscle contraction in response to α1 adrenergic agonists. Considering vasogenic shock, one can understand its utmost importance, not only because of its association with sepsis but also because it can be the common final pathway for long-lasting, severe shock of any cause, even postresuscitation states. The effective management of any patient in shock requires the understanding of its underlying physiology and pathophysiology. Recent studies have provided new insights into vascular physiology by revealing the interaction of rather complicated and multifactorial mechanisms, which have not been fully elucidated yet. Some of these mechanisms, such as the induction of nitric oxide synthases, the activation of adenosine triphosphate-sensitive potassium channels, and vasopressin deficiency, have gained general acceptance and are considered to play an important role in the pathogenesis of vasodilatory shock. The purpose of this review is to provide an update on the pathogenesis of vasogenic shock.Keywords: nitric oxide synthases, KATP channels, vasopressin, H2S, vasoplegic syndrome

  11. Physiology of bile secretion

    Institute of Scientific and Technical Information of China (English)

    Alejandro Esteller

    2008-01-01

    The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment,in different situations,results in the syndrome of cholestasis.The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed.Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane.This review summarizes recent data on the molecular determinants of this primary bile formation.The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bileduct epithelial cells (cholangiocytes) as bile passes through bile ducts.The mechanisms of fluid and solute transport in cholangiocytes will also be discussed.In contrast to hepatocytes where secretion is constant and poorly controlled,cholangiocyte secretion is regulated by hormones and nerves.A short section dedicated to these regulatory mechanisms of bile secretion has been included.The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

  12. Network Physiology: Mapping Interactions Between Networks of Physiologic Networks

    Science.gov (United States)

    Ivanov, Plamen Ch.; Bartsch, Ronny P.

    The human organism is an integrated network of interconnected and interacting organ systems, each representing a separate regulatory network. The behavior of one physiological system (network) may affect the dynamics of all other systems in the network of physiologic networks. Due to these interactions, failure of one system can trigger a cascade of failures throughout the entire network. We introduce a systematic method to identify a network of interactions between diverse physiologic organ systems, to quantify the hierarchical structure and dynamics of this network, and to track its evolution under different physiologic states. We find a robust relation between network structure and physiologic states: every state is characterized by specific network topology, node connectivity and links strength. Further, we find that transitions from one physiologic state to another trigger a markedly fast reorganization in the network of physiologic interactions on time scales of just a few minutes, indicating high network flexibility in response to perturbations. This reorganization in network topology occurs simultaneously and globally in the entire network as well as at the level of individual physiological systems, while preserving a hierarchical order in the strength of network links. Our findings highlight the need of an integrated network approach to understand physiologic function, since the framework we develop provides new information which can not be obtained by studying individual systems. The proposed system-wide integrative approach may facilitate the development of a new field, Network Physiology.

  13. Single Cell Physiology

    Science.gov (United States)

    Neveu, Pierre; Sinha, Deepak Kumar; Kettunen, Petronella; Vriz, Sophie; Jullien, Ludovic; Bensimon, David

    The possibility to control at specific times and specific places the activity of biomolecules (enzymes, transcription factors, RNA, hormones, etc.) is opening up new opportunities in the study of physiological processes at the single cell level in a live organism. Most existing gene expression systems allow for tissue specific induction upon feeding the organism with exogenous inducers (e.g., tetracycline). Local genetic control has earlier been achieved by micro-injection of the relevant inducer/repressor molecule, but this is an invasive and possibly traumatic technique. In this chapter, we present the requirements for a noninvasive optical control of the activity of biomolecules and review the recent advances in this new field of research.

  14. [Physiology of the neuropeptides].

    Science.gov (United States)

    García-López, M J; Martínez-Martos, J M; Mayas, M D; Carrera, M P; Ramírez- Expósito, M J

    In the present review, the characteristics of mammalian neuropeptides have been studied. Neuropeptides are widely distributed not only in the nervous system but also in the periphery. They are synthesised by neurons as large precursor molecules (pre propeptides) which have to be cleaved and modified in order to form the mature neuropeptides. Neuropeptides may exert actions as neurotransmitters, neuromodulators and/or neurohormones. In the neurons, they coexist with classic transmitters and often with other peptides. After their releasing, they bind to especific receptors to exert their action in the target cell. Most of these receptors belongs to a family of G protein coupled receptors. Finally, peptidases are the enzymes involved in the degradation of neuropeptides. Conclusions. In the last years, the number of known neuropeptides and the understanding of their functions have been increased. With these data, present investigations are looking for the treatment of different pathologies associated with alterations in the physiology of neuropeptides.

  15. Physiology for engineers applying engineering methods to physiological systems

    CERN Document Server

    Chappell, Michael

    2016-01-01

    This book provides an introduction to qualitative and quantitative aspects of human physiology. It looks at biological and physiological processes and phenomena, including a selection of mathematical models, showing how physiological problems can be mathematically formulated and studied. It also illustrates how a wide range of engineering and physics topics, including electronics, fluid dynamics, solid mechanics and control theory can be used to describe and understand physiological processes and systems. Throughout the text there are introductions to measuring and quantifying physiological processes using both signal and imaging technologies. Physiology for Engineers describes the basic structure and models of cellular systems, the structure and function of the cardiovascular system, the electrical and mechanical activity of the heart and provides an overview of the structure and function of the respiratory and nervous systems. It also includes an introduction to the basic concepts and applications of reacti...

  16. Network Physiology reveals relations between network topology and physiological function

    CERN Document Server

    Bashan, Amir; Kantelhardt, Jan W; Havlin, Shlomo; Ivanov, Plamen Ch; 10.1038/ncomms1705

    2012-01-01

    The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate the development of a new field, Network Physiology.

  17. Network physiology reveals relations between network topology and physiological function

    OpenAIRE

    Bashan, Amir; Bartsch, Ronny P.; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

    2012-01-01

    The human organism is an integrated network where complex physiological systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here we develop a framework to probe interactions among diverse systems, and we identify a physiological network. We find that each physiological state is...

  18. Cardiovascular physiology and sleep.

    Science.gov (United States)

    Murali, Narayana S; Svatikova, Anna; Somers, Virend K

    2003-05-01

    Sleep is a natural periodic suspension of consciousness during which processes of rest and restoration occur. The cognitive, reparative and regenerative accompaniments of sleep appear to be essential for maintenance of health and homeostasis. This brief overview will examine the cardiovascular responses to normal and disordered sleep, and their physiologic and pathologic implications. In the past, sleep was believed to be a passive state. The tableau of sleep as it unfolds is anything but a passive process. The brain's activity is as complex as wakefulness, never "resting" during sleep. Following the demise of the 'passive theory of sleep' (the reticular activating system is fatigued during the waking day and hence becomes inactive), there arose the 'active theory of sleep' (sleep is due to an active general inhibition of the brain) (1). Hess demonstrated the active nature of sleep in cats, inducing "physiological sleep" with electrical stimulation of the diencephalon (2). Classical experiments of transection of the cat brainstem (3) at midpontine level inhibited sleep completely, implying that centers below this level were involved in the induction of sleep (1, 4). For the first time, measurement of sleep depth without awakening the sleeper using the electroencephalogram (EEG) was demonstrated in animals by Caton and in humans, by Berger (1). This was soon followed by discovery of the rapid eye movement sleep periods (REM) by Aserinski and Kleitman (5), demonstration of periodical sleep cycles and their association with REM sleep (6, 7). Multiple studies and steady discoveries (4) made polysomnography, with its ability to perform simultaneous whole night recordings of EEG, electromyogram (EMG), and electrooculogram (EOC), a major diagnostic tool in study of sleep disorders. This facility has been of further critical importance in allowing evaluation of the interaction between sleep and changes in hemodynamics and autonomic cardiovascular control. Consequently the

  19. Physiology of vitreous surgery.

    Science.gov (United States)

    Stefánsson, Einar

    2009-02-01

    Vitreous surgery has various physiological and clinical consequences, both beneficial and harmful. Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The laws of Fick, Stokes-Einstein and Hagen-Poiseuille state that molecular transport by diffusion or convection is inversely related to the viscosity of the medium. When the vitreous gel is replaced with less viscous saline, the transport of all molecules, including oxygen and cytokines, is facilitated. Oxygen transport to ischemic retinal areas is improved, as is clearance of VEGF and other cytokines from these areas, thus reducing edema and neovascularization. At the same time, oxygen is transported faster down a concentration gradient from the anterior to the posterior segment, while VEGF moves in the opposite direction, making the anterior segment less oxygenated and with more VEGF, stimulating iris neovascularization. Silicone oil is the exception that proves the rule: it is more viscous than vitreous humour, re-establishes the transport barrier to oxygen and VEGF, and reduces the risk for iris neovascularization in the vitrectomized-lentectomized eye. Modern vitreous surgery involves a variety of treatment options in addition to vitrectomy itself, such as photocoagulation, anti-VEGF drugs, intravitreal steroids and release of vitreoretinal traction. A full understanding of these treatment modalities allows sensible combination of treatment options. Retinal photocoagulation has repeatedly been shown to improve retinal oxygenation, as does vitrectomy. Oxygen naturally reduces VEGF production and improves retinal hemodynamics. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and the permeability effect of VEGF reduced with corticosteroids

  20. Procedures of Exercise Physiology Laboratories

    Science.gov (United States)

    Bishop, Phillip A.; Fortney, Suzanne; Greenisen, Michael; Siconolfi, Steven F.; Bamman, Marcas M.; Moore, Alan D., Jr.; Squires, William

    1998-01-01

    This manual describes the laboratory methods used to collect flight crew physiological performance data at the Johnson Space Center. The Exercise Countermeasures Project Laboratory is a standard physiology laboratory; only the application to the study of human physiological adaptations to spaceflight is unique. In the absence of any other recently published laboratory manual, this manual should be a useful document staffs and students of other laboratories.

  1. Conservation physiology of marine fishes

    DEFF Research Database (Denmark)

    Jørgensen, Christian; Peck, Myron A.; Antognarelli, Fabio

    2012-01-01

    At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology...... to different extents, ranging from no explicit consideration to detailed physiological mechanisms, and across scales from a single fish to global fishery resources. Biologists from different sub-disciplines are collaborating to rise to the challenge of projecting future changes in distribution and productivity...

  2. Starting physiology: bioelectrogenesis.

    Science.gov (United States)

    Baptista, Vander

    2015-12-01

    From a Cartesian perspective of rational analysis, the electric potential difference across the cell membrane is one of the fundamental concepts for the study of physiology. Unfortunately, undergraduate students often struggle to understand the genesis of this energy gradient, which makes the teaching activity a hard task for the instructor. The topic of bioelectrogenesis encompasses multidisciplinary concepts, involves several mechanisms, and is a dynamic process, i.e., it never turns off during the lifetime of the cell. Therefore, to improve the transmission and acquisition of knowledge in this field, I present an alternative didactic model. The design of the model assumes that it is possible to build, in a series of sequential steps, an assembly of proteins within the membrane of an isolated cell in a simulated electrophysiology experiment. Initially, no proteins are inserted in the membrane and the cell is at a baseline energy state; the extracellular and intracellular fluids are at thermodynamic equilibrium. Students are guided through a sequence of four steps that add key membrane transport proteins to the model cell. The model is simple at the start and becomes progressively more complex, finally producing transmembrane chemical and electrical gradients. I believe that this didactic approach helps instructors with a more efficient tool for the teaching of the mechanisms of resting membrane potential while helping students avoid common difficulties that may be encountered when learning this topic.

  3. Hypertension: physiology and pathophysiology.

    Science.gov (United States)

    Hall, John E; Granger, Joey P; do Carmo, Jussara M; da Silva, Alexandre A; Dubinion, John; George, Eric; Hamza, Shereen; Speed, Joshua; Hall, Michael E

    2012-10-01

    Despite major advances in understanding the pathophysiology of hypertension and availability of effective and safe antihypertensive drugs, suboptimal blood pressure (BP) control is still the most important risk factor for cardiovascular mortality and is globally responsible for more than 7 million deaths annually. Short-term and long-term BP regulation involve the integrated actions of multiple cardiovascular, renal, neural, endocrine, and local tissue control systems. Clinical and experimental observations strongly support a central role for the kidneys in the long-term regulation of BP, and abnormal renal-pressure natriuresis is present in all forms of chronic hypertension. Impaired renal-pressure natriuresis and chronic hypertension can be caused by intrarenal or extrarenal factors that reduce glomerular filtration rate or increase renal tubular reabsorption of salt and water; these factors include excessive activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, increased formation of reactive oxygen species, endothelin, and inflammatory cytokines, or decreased synthesis of nitric oxide and various natriuretic factors. In human primary (essential) hypertension, the precise causes of impaired renal function are not completely understood, although excessive weight gain and dietary factors appear to play a major role since hypertension is rare in nonobese hunter-gathers living in nonindustrialized societies. Recent advances in genetics offer opportunities to discover gene-environment interactions that may also contribute to hypertension, although success thus far has been limited mainly to identification of rare monogenic forms of hypertension. © 2012 American Physiological Society

  4. Physiology in Modelica

    Directory of Open Access Journals (Sweden)

    Marek Mateják

    2014-05-01

    Full Text Available Modelica is an object-oriented language, in which models can be created and graphically represented by connecting instances of classes from libraries. These connections are not only assignments of values; they can also represent acausal equality. Even more, they can model Kirchhoff’s laws of circuits. In Modelica it is possible to develop library classes which are an analogy of electrical circuit components. The result of our work in this field is Physiolibrary (www.physiolibrary.org – a free, open-source Modelica library for human physiology. By graphical joining instances of Physiolibrary classes, user can create models of cardiovascular circulation, thermoregulation, metabolic processes, nutrient distribution, gas transport, electrolyte regulation, water distribution, hormonal regulation and pharmacological regulation. After simple setting of the parameters, the models are ready to simulate. After simulation, the user can examine variables as their values change over time. Representing the model as a diagram has also great educational advantages, because students are able to better understand physical principles when they see them modeled graphically.

  5. Smolt physiology and endocrinology

    Science.gov (United States)

    McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

    2013-01-01

    Hormones play a critical role in maintaining body fluid balance in euryhaline fishes during changes in environmental salinity. The neuroendocrine axis senses osmotic and ionic changes, then signals and coordinates tissue-specific responses to regulate water and ion fluxes. Rapid-acting hormones, e.g. angiotensins, cope with immediate challenges by controlling drinking rate and the activity of ion transporters in the gill, gut, and kidney. Slow-acting hormones, e.g. prolactin and growth hormone/insulin-like growth factor-1, reorganize the body for long-term acclimation by altering the abundance of ion transporters and through cell proliferation and differentiation of ionocytes and other osmoregulatory cells. Euryhaline species exist in all groups of fish, including cyclostomes, and cartilaginous and teleost fishes. The diverse strategies for responding to changes in salinity have led to differential regulation and tissue-specific effects of hormones. Combining traditional physiological approaches with genomic, transcriptomic, and proteomic analyses will elucidate the patterns and diversity of the endocrine control of euryhalinity.

  6. Polyamines in plant physiology

    Science.gov (United States)

    Galston, A. W.; Sawhney, R. K.

    1990-01-01

    The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their chemistry and pathways of biosynthesis and metabolism are well characterized. They occur in the free form as cations, but are often conjugated to small molecules like phenolic acids and also to various macromolecules. Their titer varies from approximately micromolar to more than millimolar, and depends greatly on environmental conditions, especially stress. In cereals, the activity of one of the major polyamine biosynthetic enzymes, arginine decarboxylase, is rapidly and dramatically increased by almost every studied external stress, leading to 50-fold or greater increases in putrescine titer within a few hours. The physiological significance of this increase is not yet clear, although most recent work suggests an adaptive, protective role. Polyamines produced through the action of ornithine decarboxylase, by contrast, seem essential for DNA replication and cell division. The application of exogenous polyamines produces effects on patterns of senescence and morphogenesis, suggesting but not proving a regulatory role for polyamines in these processes. The evidence for such a regulatory role is growing.

  7. DOSHIC PHYSIOLOGY OF SKIN

    Directory of Open Access Journals (Sweden)

    Shivprasad Chiplunkar

    2013-06-01

    Full Text Available The balance of dosha  represents the healthy state and imbalance will cause various diseases. In normalcy doshas will be performing their own functions and individual doshas will be having their own specific sites. By telling the various sthana of each dosha, different function that is taken up by individual dosha in different sites has been highlighted.By mentioning ‘sparshanendriyam’ as one of the sthana of vata dosha the sensory functions of skin to vata dosha has been emphasised. By mentioning ‘sparshanam’ as one of the sthana of pittadosha, the function of colouring/pigmentation of skin, which is majorly carried out  by melanocytes by secreting melanin pigment has been highlighted. Meda is one among the sthanas of kapha dosha; this can be considered as the adipose tissue of skin/below skin. Since sweda is mala of meda it can be also considered as the secretions from the eccrine glands.With respect to skin, sensory functions, both tactile and thermal is carried out by vata dosha more specifically vyana vata, pigmentation to the skin carried out by meloncytes by secreting melanin, it is nothing but function of pitta dosha more specifically brajaka pitta with the help of udana vata and finally production of sweat in sweat glands is the function of kapha. So there is the need for further study and research regarding the sthanas of all three doshas in different structures/organs in the body and its physiology.

  8. Physiology of Volition

    Science.gov (United States)

    Hallett, Mark

    The idea of free will is a conscious awareness of the brain concerning the nature of the movement that it produces. There is no evidence for it to be a driving force in movement generation. This review considers the physiology of movement generation and how the concepts of willing and agency might arise. Both the anatomical substrates and the timing of events are considered. Movement initiation and volition are not necessarily linked, and one line of evidence comes from consideration of patients with disorders of volition. Movement is generated subconsciously, and the conscious sense of willing the movement comes later, but the exact time of this event is difficult to assess because of the potentially illusory nature of introspection. The evidence suggests that movement is initiated in frontal lobe, particularly the mesial areas, and the sense of volition arises as the result of a corollary discharge from premotor and motor areas likely involving the parietal lobe. Agency probably involves a similar region in the parietal lobe and requires both the sense of volition and movement feedback.

  9. Causality in physiological signals.

    Science.gov (United States)

    Müller, Andreas; Kraemer, Jan F; Penzel, Thomas; Bonnemeier, Hendrik; Kurths, Jürgen; Wessel, Niels

    2016-05-01

    Health is one of the most important non-material assets and thus also has an enormous influence on material values, since treating and preventing diseases is expensive. The number one cause of death worldwide today originates in cardiovascular diseases. For these reasons the aim of understanding the functions and the interactions of the cardiovascular system is and has been a major research topic throughout various disciplines for more than a hundred years. The purpose of most of today's research is to get as much information as possible with the lowest possible effort and the least discomfort for the subject or patient, e.g. via non-invasive measurements. A family of tools whose importance has been growing during the last years is known under the headline of coupling measures. The rationale for this kind of analysis is to identify the structure of interactions in a system of multiple components. Important information lies for example in the coupling direction, the coupling strength, and occurring time lags. In this work, we will, after a brief general introduction covering the development of cardiovascular time series analysis, introduce, explain and review some of the most important coupling measures and classify them according to their origin and capabilities in the light of physiological analyses. We will begin with classical correlation measures, go via Granger-causality-based tools, entropy-based techniques (e.g. momentary information transfer), nonlinear prediction measures (e.g. mutual prediction) to symbolic dynamics (e.g. symbolic coupling traces). All these methods have contributed important insights into physiological interactions like cardiorespiratory coupling, neuro-cardio-coupling and many more. Furthermore, we will cover tools to detect and analyze synchronization and coordination (e.g. synchrogram and coordigram). As a last point we will address time dependent couplings as identified using a recent approach employing ensembles of time series. The

  10. Applied physiology of cycling.

    Science.gov (United States)

    Faria, I E

    1984-01-01

    Historically, the bicycle has evolved through the stages of a machine for efficient human transportation, a toy for children, a finely-tuned racing machine, and a tool for physical fitness development, maintenance and testing. Recently, major strides have been made in the aerodynamic design of the bicycle. These innovations have resulted in new land speed records for human powered machines. Performance in cycling is affected by a variety of factors, including aerobic and anaerobic capacity, muscular strength and endurance, and body composition. Bicycle races range from a 200m sprint to approximately 5000km. This vast range of competitive racing requires special attention to the principle of specificity of training. The physiological demands of cycling have been examined through the use of bicycle ergometers, rollers, cycling trainers, treadmill cycling, high speed photography, computer graphics, strain gauges, electromyography, wind tunnels, muscle biopsy, and body composition analysis. These techniques have been useful in providing definitive data for the development of a work/performance profile of the cyclist. Research evidence strongly suggests that when measuring the cyclist's aerobic or anaerobic capacity, a cycling protocol employing a high pedalling rpm should be used. The research bicycle should be modified to resemble a racing bicycle and the cyclist should wear cycling shoes. Prolonged cycling requires special nutritional considerations. Ingestion of carbohydrates, in solid form and carefully timed, influences performance. Caffeine appears to enhance lipid metabolism. Injuries, particularly knee problems which are prevalent among cyclists, may be avoided through the use of proper gearing and orthotics. Air pollution has been shown to impair physical performance. When pollution levels are high, training should be altered or curtailed. Effective training programmes simulate competitive conditions. Short and long interval training, blended with long

  11. Physiology of Visceral Pain.

    Science.gov (United States)

    Gebhart, G F; Bielefeldt, Klaus

    2016-09-15

    Pain involving thoracic, abdominal, or pelvic organs is a common cause for physician consultations, including one-third of chronic pain patients who report that visceral organs contribute to their suffering. Chronic visceral pain conditions are typically difficult to manage effectively, largely because visceral sensory mechanisms and factors that contribute to the pathogenesis of visceral pain are poorly understood. Mechanistic understanding is particularly problematic in "functional" visceral diseases where there is no apparent pathology and pain typically is the principal complaint. We review here the anatomical organization of the visceral sensory innervation that distinguishes the viscera from innervation of all other tissues in the body. The viscera are innervated by two nerves that share overlapping functions, but also possess notably distinct functions. Additionally, the visceral innervation is sparse relative to the sensory innervation of other tissues. Accordingly, visceral sensations tend to be diffuse in character, are typically referred to nonvisceral somatic structures and thus are difficult to localize. Early arguments about whether the viscera were innervated ("sensate") and later, whether innervated by nociceptors, were resolved by advances reviewed here in the anatomical and functional attributes of receptive endings in viscera that contribute to visceral pain (i.e., visceral nociceptors). Importantly, the contribution of plasticity (i.e., sensitization) of peripheral and central visceral nociceptive mechanisms is considered in the context of persistent, chronic visceral pain conditions. The review concludes with an overview of the functional anatomy of visceral pain processing. © 2016 American Physiological Society. Compr Physiol 6:1609-1633, 2016. Copyright © 2016 John Wiley & Sons, Inc.

  12. Assessing prebaccalaureate human physiology courses.

    Science.gov (United States)

    McCleary, V L

    1998-12-01

    Two surveys were conducted between 1994 and 1996. The purpose of the initial survey was to obtain demographic information about prebaccaulareate human physiology courses. Of the 117 responding physiology departments, 50% offered human physiology at the prebaccalaureate level to 14,185 students during the 1994-1995 academic year. The mean was 245 students per year (+/- 30 SE). Class size was limited by 44% of the respondents. Prebaccaluareate human physiology was offered as a separate course from anatomy by 93% of the departments. Sixty-one percent scheduled the course once a year. The purpose of the second survey was to determine how physiology departments evaluated prebaccalaureate physiology courses and faculty. All responding departments utilized student feedback; 38% of the departments included physiology chair review, 38% peer review, and 9% allied health faculty review. Twenty-eight percent of allied health programs evaluated the course. Results indicated that, whereas a significant number of undergraduate students are enrolled in prebaccaluareate physiology courses annually, those courses appear to lack formal, consistent formative evaluation.

  13. Applied physiology of swimming.

    Science.gov (United States)

    Lavoie, J M; Montpetit, R R

    1986-01-01

    Scientific research in swimming over the past 10 to 15 years has been oriented toward multiple aspects that relate to applied and basic physiology, metabolism, biochemistry, and endocrinology. This review considers recent findings on: 1) specific physical characteristics of swimmers; 2) the energetics of swimming; 3) the evaluation of aerobic fitness in swimming; and 4) some metabolic and hormonal aspects related to swimmers. Firstly, the age of finalists in Olympic swimming is not much different from that of the participants from other sports. They are taller and heavier than a reference population of the same age. The height bias in swimming may be the reason for lack of success from some Asian and African countries. Experimental data point toward greater leanness, particularly in female swimmers, than was seen 10 years ago. Overall, female swimmers present a range of 14 to 19% body fat whereas males are much lower (5 to 10%). Secondly, the relationship between O2 uptake and crawl swimming velocity (at training and competitive speeds) is thought to be linear. The energy cost varies between strokes with a dichotomy between the 2 symmetrical and the 2 asymmetrical strokes. Energy expenditure in swimming is represented by the sum of the cost of translational motion (drag) and maintenance of horizontal motion (gravity). The cost of the latter decreases as speed increases. Examination of the question of size-associated effects on the cost of swimming using Huxley's allometric equation (Y = axb) shows an almost direct relationship with passive drag. Expressing energy cost in litres of O2/m/kg is proposed as a better index of technical swimming ability than the traditional expression of VO2/distance in L/km. Thirdly, maximal direct conventional techniques used to evaluate maximal oxygen consumption (VO2 max) in swimming include free swimming, tethered swimming, and flume swimming. Despite the individual peculiarities of each method, with similar experimental conditions

  14. Cassava biology and physiology.

    Science.gov (United States)

    El-Sharkawy, Mabrouk A

    2004-11-01

    Cassava or manioc (Manihot esculenta Crantz), a perennial shrub of the New World, currently is the sixth world food crop for more than 500 million people in tropical and sub-tropical Africa, Asia and Latin America. It is cultivated mainly by resource-limited small farmers for its starchy roots, which are used as human food either fresh when low in cyanogens or in many processed forms and products, mostly starch, flour, and for animal feed. Because of its inherent tolerance to stressful environments, where other food crops would fail, it is often considered a food-security source against famine, requiring minimal care. Under optimal environmental conditions, it compares favorably in production of energy with most other major staple food crops due to its high yield potential. Recent research at the Centro Internacional de Agricultura Tropical (CIAT) in Colombia has demonstrated the ability of cassava to assimilate carbon at very high rates under high levels of humidity, temperature and solar radiation,which correlates with productivity across all environments whether dry or humid. When grown on very poor soils under prolonged drought for more than 6 months, the crop reduce both its leaf canopy and transpiration water loss, but its attached leaves remain photosynthetically active, though at greatly reduced rates. The main physiological mechanism underlying such a remarkable tolerance to drought was rapid stomatal closure under both atmospheric and edaphic water stress, protecting the leaf against dehydration while the plant depletes available soil water slowly during long dry periods. This drought tolerance mechanism leads to high crop water use efficiency values. Although the cassava fine root system is sparse, compared to other crops, it can penetrate below 2 m soil,thus enabling the crop to exploit deep water if available. Leaves of cassava and wild Manihot possess elevated activities of the C4 enzyme PEP carboxylase but lack the leaf Kranz anatomy typical of C4

  15. Understanding the physiology of schizophrenia.

    Science.gov (United States)

    Kirkpatrick, Brian

    2013-03-01

    The physiology of schizophrenia includes complex genetic and environmental interactions. Current treatment largely focuses on positive symptoms, but many patients with schizophrenia present with additional symptoms and conditions that hinder their social and occupational functioning. The study of the physiology of this disorder has expanded beyond dopamine dysfunction to include the glutamate, serotonin, and nicotinic/acetylcholine systems, as well as physiologic abnormalities such as diabetes and inflammation. Clinicians who understand these additional problem areas can incorporate them into their assessment and treatment plans for patients with schizophrenia. © Copyright 2013 Physicians Postgraduate Press, Inc.

  16. Medical electronics and physiological measurement

    Science.gov (United States)

    Cochrane, T.

    1989-07-01

    This article describes some recent developments in physiological measurement since the last `special issue' in 1978. Nine examples are given covering mature applications, new techniques and some `ideas for the future'. The need for good scientists in this interesting and challenging area is stressed. Physiological measurement is challenging because human physiology is complex. The examples described in this article illustrate some areas where cooperation between basic scientists, engineers, clinicians and, not least, patients has led to remarkable advances in our understanding of man and his physiology. Many challenges still lie ahead. There is no doubt that good quality graduates, with fresh minds and fresh enthusiasm, are needed to build on the foundation that has already been laid.

  17. Survey of Departments of Physiology

    Science.gov (United States)

    Ganong, William F.

    1977-01-01

    Presents data of the 1976 survey of departments of physiology. Includes comparison to 1974 and 1975 data for number of academic positions available, department budgets, graduate students and post doctoral fellows, and salaries. (SL)

  18. Physiology of the fetal circulation.

    Science.gov (United States)

    Kiserud, Torvid

    2005-12-01

    Our understanding of fetal circulatory physiology is based on experimental animal data, and this continues to be an important source of new insight into developmental mechanisms. A growing number of human studies have investigated the human physiology, with results that are similar but not identical to those from animal studies. It is time to appreciate these differences and base more of our clinical approach on human physiology. Accordingly, the present review focuses on distributional patterns and adaptational mechanisms that were mainly discovered by human studies. These include cardiac output, pulmonary and placental circulation, fetal brain and liver, venous return to the heart, and the fetal shunts (ductus venosus, foramen ovale and ductus arteriosus). Placental compromise induces a set of adaptational and compensational mechanisms reflecting the plasticity of the developing circulation, with both short- and long-term implications. Some of these aspects have become part of the clinical physiology of today with consequences for surveillance and treatment.

  19. Olfaction: anatomy, physiology and behavior

    OpenAIRE

    Benignus, Vernon A.; Prah, James D.

    1982-01-01

    The anatomy, physiology and function of the olfactory system are reviewed, as are the normal effects of olfactory stimulation. It is speculated that olfaction may have important but unobtrusive effects on human behavior.

  20. Survey of Departments of Physiology

    Science.gov (United States)

    Ganong, William F.

    1977-01-01

    Presents data of the 1976 survey of departments of physiology. Includes comparison to 1974 and 1975 data for number of academic positions available, department budgets, graduate students and post doctoral fellows, and salaries. (SL)

  1. Physiological Control of Germline Development

    OpenAIRE

    Hubbard, E. Jane Albert; Korta, Dorota Z.; Dalfó, Diana

    2013-01-01

    The intersection between developmental programs and environmental conditions that alter physiology is a growing area of research interest. The C. elegans germ line is emerging as a particularly sensitive and powerful model for these studies. The germ line is subject to environmentally regulated diapause points that allow worms to withstand harsh conditions both prior to and after reproduction commences. It also responds to more subtle changes in physiological conditions. Recent studies demons...

  2. Seasonal changes in reindeer physiology

    OpenAIRE

    A. Reeta Pösö

    2005-01-01

    The seasonal changes in the photoperiod, temperature and availability of food need to be converted to hormonal signals in order to induce adaptations in the physiology of the reindeer. The most reliable of the seasonal changes in the environment is the photoperiod, which affects the reindeer physiology through pineal gland and its hormone, melatonin. Usually there are large diurnal changes in the concentration of melatonin, but in the reindeer the daily rhythm disappears during the arctic sum...

  3. Physiologically relevant organs on chips.

    Science.gov (United States)

    Yum, Kyungsuk; Hong, Soon Gweon; Healy, Kevin E; Lee, Luke P

    2014-01-01

    Recent advances in integrating microengineering and tissue engineering have generated promising microengineered physiological models for experimental medicine and pharmaceutical research. Here we review the recent development of microengineered physiological systems, or also known as "ogans-on-chips", that reconstitute the physiologically critical features of specific human tissues and organs and their interactions. This technology uses microengineering approaches to construct organ-specific microenvironments, reconstituting tissue structures, tissue-tissue interactions and interfaces, and dynamic mechanical and biochemical stimuli found in specific organs, to direct cells to assemble into functional tissues. We first discuss microengineering approaches to reproduce the key elements of physiologically important, dynamic mechanical microenvironments, biochemical microenvironments, and microarchitectures of specific tissues and organs in microfluidic cell culture systems. This is followed by examples of microengineered individual organ models that incorporate the key elements of physiological microenvironments into single microfluidic cell culture systems to reproduce organ-level functions. Finally, microengineered multiple organ systems that simulate multiple organ interactions to better represent human physiology, including human responses to drugs, is covered in this review. This emerging organs-on-chips technology has the potential to become an alternative to 2D and 3D cell culture and animal models for experimental medicine, human disease modeling, drug development, and toxicology.

  4. Conservation physiology of animal migration.

    Science.gov (United States)

    Lennox, Robert J; Chapman, Jacqueline M; Souliere, Christopher M; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D; Cooke, Steven J

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  5. Physiological Studies of Lactococcus lactis

    DEFF Research Database (Denmark)

    Hansen, Gunda

    industrial production by employing flow cytometry for viability assessment, cell size comparison, intracellular pH (pHi) determination and cell sorting. The physiological studies of L. lactis were complemented by examining the growth behavior, glucose consumption, lactate production, culturability on solid...... was found to facilitate the differentiation and accurate quantification of L. lactis cells in different physiological states, which agreed with the reproductive viability of reference samples and of exponential cells. The high viability of one particular L. lactis strain demonstrated its robustness during......, cell size comparison and pHi determination reflected the increasing physiological impairment during this accelerated stability test, while a preincubation in buffer led to inconsistent flow cytometric results. The comparison of reproductive and growth-independent viability suggested the presence...

  6. Stimulating Student Interest in Physiology: The Intermedical School Physiology Quiz

    Science.gov (United States)

    Cheng, Hwee-Ming

    2010-01-01

    The Intermedical School Physiology Quiz (IMSPQ) was initiated in 2003 during the author's last sabbatical from the University of Malaya. At this inaugural event, there were just seven competing teams from Malaysian medical schools. The challenge trophy for the IMSPQ is named in honor of Prof. A. Raman, who was the first Malaysian Professor of…

  7. Electronic Textbook in Human Physiology.

    Science.gov (United States)

    Broering, Naomi C.; Lilienfield, Lawrence S.

    1994-01-01

    Describes the development of an electronic textbook in human physiology at the Georgetown University Medical Center Library that was designed to enhance learning and visualization through a prototype knowledge base of core instructional materials stored in digital format on Macintosh computers. The use of computers in the medical curriculum is…

  8. Exercise Effects on Sleep Physiology

    Directory of Open Access Journals (Sweden)

    Sunao eUchida

    2012-04-01

    Full Text Available This mini-review focuses on the effects of exercise on sleep. In its early days, sleep research largely focused on central nervous system (CNS physiology using standardized tabulations of several sleep-specific landmark electroencephalogram (EEG waveforms. Though coarse, this method has enabled the observation and inspection of numerous uninterrupted sleep phenomena. Thus, research on the effects of exercise on sleep began, in the 1960’s, with a focus primarily on sleep EEG (CNS sleep changes. Those early studies found only small effects of exercise on sleep. More recent sleep research has explored not only CNS functioning, but somatic physiology as well. As physical exercise mostly affects somatic functions, endocrine and autonomic nervous system (ANS changes that occur during sleep should be affected by daytime exercise. Since endocrinological, metabolic and autonomic changes can be measured during sleep, it should be possible to assess exercise effects on somatic physiology in addition to CNS sleep quality, building from standard polysomnographic (PSG techniques. Incorporating measures of somatic physiology in the quantitative assessment of sleep could further our understanding of sleep's function as an auto-regulatory, global phenomenon.

  9. Physiological aspects of paired stimulation

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1966-01-01

    Starling's law of the heart states that "the energy of contraction, however measured, is a function of the length of the muscle fibre" (Starling, 1915). This physiological property of myocardial and skeletal muscle enables the heart, within certain limits, to eject during each systole the amount

  10. The Limits of Exercise Physiology

    DEFF Research Database (Denmark)

    Gabriel, Brendan M; Zierath, Juleen R

    2017-01-01

    Many of the established positive health benefits of exercise have been documented by historical discoveries in the field of exercise physiology. These investigations often assess limits: the limits of performance, or the limits of exercise-induced health benefits. Indeed, several key findings have...

  11. Physiological specialization of Stagonospora nodorum

    Science.gov (United States)

    Septoriosis is a harmful disease of wheat, widespread all over the world, including Russia. Stagonospora nodorum (Berk.) Castellani and E.G. Germano is one of the main agents of Septoria wheat diseases. There is no information on physiological specialization of this pathogen. Not many authors stud...

  12. Physiological adaptation in desert birds

    NARCIS (Netherlands)

    Williams, JB; Tieleman, BI; Williams, Joseph B.

    2005-01-01

    We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement

  13. Reproductive Physiology in Cetaceans (Review)

    OpenAIRE

    1996-01-01

    This paper briefly reviews some works on reproductive physiology in cetaceans with special reference to dolphins from the following aspects: estrous cycle in female dolphins, hormonal profiles during pregnancy, testosterone levels and seasonality in testicular activity, ovulation induction and sperm collection and freezing.

  14. Applied physiology of water polo.

    Science.gov (United States)

    Smith, H K

    1998-11-01

    Water polo has been played for over a century. While the rules of the game have evolved considerably over this time, the sport has consistently remained, physiologically, a highly demanding activity. Much attention has been paid to the technical and strategic elements of the game; however, despite the potential for improvements in athletic performance and the maintenance of athletes' health, there are few published studies (particularly in English) on the physical and physiological demands and adaptations to water polo training and competition. Game analyses have demonstrated that water polo is an 'intermittent' sport comprised of intense bursts of activity of movements required for playing water polo also place considerable demands on the neuromuscular system. Observations of the frequency and duration of the different activities, and of the physiological responses to participating in a water polo match, are initial sources of information for designing training programmes specific to the game and to the different playing positions. The physical and physiological attributes of elite water polo players offer some insight into the minimum requirements for participation and the adaptations that result from training and competition. Further systematic documentation and experimentation are required to facilitate the design and specification of individual training programmes and to better understand the long term effects of water polo on athletes' health.

  15. PHYSIOLOGIC BASIS OF NASAL OPERATIONS

    Science.gov (United States)

    Hilding, A. C.

    1950-01-01

    To be successful, intranasal operations must be so designed as to restore the normal physiologic function of the nose. It is impossible with impunity to operate upon the interior of the nose as though it were simply an air flue and on the sinuses as though they were boxes. PMID:15400563

  16. Physiological Monitoring in Diving Mammals

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Physiological Monitoring in Diving Mammals Andreas...825-2025 email: andreas.fahlman@tamucc.edu Peter L. Tyack School of Biology Sea Mammal Research Unit Scottish Oceans Institute...OBJECTIVES This project is separated into three aims: Aim 1: Develop a new generation of tags/data logger for marine mammals that will

  17. Network Physiology: Mapping interactions between complex physiological systems

    OpenAIRE

    Ivanov, Plamen Ch.

    2016-01-01

    The human organism is an integrated network where multi-component organ systems, each with its own regulatory mechanisms, continuously interact to optimize and coordinate their function. Organ-to-organ interactions occur at multiple levels and spatiotemporal time scales to produce distinct physiologic states: wake and sleep; light and deep sleep; consciousness and unconsciousness. Disrupting organ communications can lead to dysfunction of individual systems or to collapse of the entire organ...

  18. PHYSIOLOGY OF ACID BASE BALANCE

    Directory of Open Access Journals (Sweden)

    Awati

    2014-12-01

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

  19. Anatomy and physiology of cisternostomy

    Institute of Scientific and Technical Information of China (English)

    Iype Cherian; Giovanni Grasso; Antonio Bernardo; Sunil Munakomi

    2016-01-01

    Cisternostomy is defined as opening the basal cisterns to atmospheric pressure.This technique helps to reduce the intracranial pressure in severe head trauma as well as other conditions when the so-called sudden "brain swelling" troubles the surgeon.We elaborated the surgical anatomy of this procedure as well as the proposed physiology of how cisternostomy works.This novel technique may change the current trends in neurosurgery.

  20. [C-peptide physiological effects].

    Science.gov (United States)

    Shpakov, A O; Granstrem, O K

    2013-02-01

    In the recent years there were numerous evidences that C-peptide, which was previously considered as a product of insulin biosynthesis, is one of the key regulators of physiological processes. C-peptide via heterotrimeric G(i/o) protein-coupled receptors activates a wide range of intracellular effector proteins and transcription factors and, thus, controls the inflammatory and neurotrophic processes, pain sensitivity, cognitive function, macro- and microcirculation, glomerular filtration. These effects of C-peptide are mainly expressed in its absolute or relative deficiency occurred in type 1 diabetes mellitus and they are less pronounced when the level of C-peptide is close to normal. Replacement therapy with C-peptide prevents many complications of type 1 diabetes, such as atherosclerosis, diabetic peripheral neuropathy, and nephropathy. C-peptide interacts with the insulin hexamer complexes and induces their dissociation and, as a result, regulates the functional activity of the insulin signaling system. At the same time, C-peptide at the concentrations above physiological may demonstrate pro-inflammatory effects on the endothelial cells and cause atherosclerotic changes in the vessels, which should be considered in the study of pathogenic mechanisms of complications of type 2 diabetes mellitus, where the level of C peptide is increased, as well as in the development of approaches for C-peptide application in clinic. This review is devoted contemporary achievements and unsolved problems in the study of C-peptide, as an important regulator of physiological and biochemical processes.

  1. Neuronal responses to physiological stress

    Directory of Open Access Journals (Sweden)

    Konstantinos eKagias

    2012-10-01

    Full Text Available Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. Physiological stress can be divided into three different aspects: environmental stress, intrinsic developmental stress and aging. Throughout life all living organisms are challenged by changes in the environment. Fluctuations in oxygen levels, temperature and redox state for example, trigger molecular events that enable an organism to adapt, survive and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner chemistry during normal development. For example, conditions such as intrinsic hypoxia and oxidative stress, which result from an increase in tissue mass, have to be confronted by developing embryos in order to complete their development. Finally, organisms face the challenge of stochastic accumulation of molecular damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review the responses of neurons to various physiological stressors at the molecular and cellular level.

  2. Physiology of psychogenic movement disorders.

    Science.gov (United States)

    Hallett, Mark

    2010-08-01

    Psychogenic movement disorders (PMDs) are common, but their physiology is largely unknown. In most situations, the movement is involuntary, but in a minority, when the disorder is malingering or factitious, the patient is lying and the movement is voluntary. Physiologically, we cannot tell the difference between voluntary and involuntary. The Bereitschaftspotential (BP) is indicative of certain brain mechanisms for generating movement, and is seen with ordinarily voluntary movements, but by itself does not indicate that a movement is voluntary. There are good clinical neurophysiological methods available to determine whether myoclonus or tremor is a PMD. For example, psychogenic myoclonus generally has a BP, and psychogenic stimulus-sensitive myoclonus has a variable latency with times similar to normal reaction times. Psychogenic tremor will have variable frequency over time, be synchronous in the two arms, and might well be entrained with voluntary rhythmic movements. These facts suggest that PMDs share voluntary mechanisms for movement production. There are no definitive tests to differentiate psychogenic dystonia from organic dystonia, although one has been recently reported. Similar physiological abnormalities are seen in both groups. The question arises as to how a movement can be produced with voluntary mechanisms, but not be considered voluntary.

  3. Physiology of in vitro culture

    Directory of Open Access Journals (Sweden)

    Maria Jesús Cañal

    2001-01-01

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

  4. Physiological and pathological cardiac hypertrophy.

    Science.gov (United States)

    Shimizu, Ippei; Minamino, Tohru

    2016-08-01

    The heart must continuously pump blood to supply the body with oxygen and nutrients. To maintain the high energy consumption required by this role, the heart is equipped with multiple complex biological systems that allow adaptation to changes of systemic demand. The processes of growth (hypertrophy), angiogenesis, and metabolic plasticity are critically involved in maintenance of cardiac homeostasis. Cardiac hypertrophy is classified as physiological when it is associated with normal cardiac function or as pathological when associated with cardiac dysfunction. Physiological hypertrophy of the heart occurs in response to normal growth of children or during pregnancy, as well as in athletes. In contrast, pathological hypertrophy is induced by factors such as prolonged and abnormal hemodynamic stress, due to hypertension, myocardial infarction etc. Pathological hypertrophy is associated with fibrosis, capillary rarefaction, increased production of pro-inflammatory cytokines, and cellular dysfunction (impairment of signaling, suppression of autophagy, and abnormal cardiomyocyte/non-cardiomyocyte interactions), as well as undesirable epigenetic changes, with these complex responses leading to maladaptive cardiac remodeling and heart failure. This review describes the key molecules and cellular responses involved in physiological/pathological cardiac hypertrophy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Dynamical compensation in physiological circuits.

    Science.gov (United States)

    Karin, Omer; Swisa, Avital; Glaser, Benjamin; Dor, Yuval; Alon, Uri

    2016-11-08

    Biological systems can maintain constant steady-state output despite variation in biochemical parameters, a property known as exact adaptation. Exact adaptation is achieved using integral feedback, an engineering strategy that ensures that the output of a system robustly tracks its desired value. However, it is unclear how physiological circuits also keep their output dynamics precise-including the amplitude and response time to a changing input. Such robustness is crucial for endocrine and neuronal homeostatic circuits because they need to provide a precise dynamic response in the face of wide variation in the physiological parameters of their target tissues; how such circuits compensate their dynamics for unavoidable natural fluctuations in parameters is unknown. Here, we present a design principle that provides the desired robustness, which we call dynamical compensation (DC). We present a class of circuits that show DC by means of a nonlinear feedback loop in which the regulated variable controls the functional mass of the controlling endocrine or neuronal tissue. This mechanism applies to the control of blood glucose by insulin and explains several experimental observations on insulin resistance. We provide evidence that this mechanism may also explain compensation and organ size control in other physiological circuits.

  6. Physiological Parameters Database for Older Adults

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Physiological Parameters Database for Older Adults is available for download and contains physiological parameters values for healthy older human adults (age 60...

  7. Upper gastrointestinal physiology and diseases.

    Science.gov (United States)

    Waldum, Helge L; Kleveland, Per M; Fossmark, Reidar

    2015-06-01

    Nordic research on physiology and pathophysiology of the upper gastrointestinal tract has flourished during the last 50 years. Swedish surgeons and physiologists were in the frontline of research on the regulation of gastric acid secretion. This research finally led to the development of omeprazole, the first proton pump inhibitor. When Swedish physiologists developed methods allowing the assessment of acid secretion in isolated oxyntic glands and isolated parietal cells, the understanding of mechanisms by which gastric acid secretion is regulated took a great step forward. Similarly, in Trondheim, Norway, the acid producing isolated rat stomach model combined with a sensitive and specific method for determination of histamine made it possible to evaluate this regulation qualitatively as well as quantitatively. In Lund, Sweden, the identification of the enterochromaffin-like cell as the cell taking part in the regulation of acid secretion by producing and releasing histamine was of fundamental importance both physiologically and clinically. Jorpes and Mutt established a center at Karolinska Institutet in Stockholm for the purification of gastrointestinal hormones in the 1960s, and Danes followed up this work by excelling in the field of determination and assessment of biological role of gastrointestinal hormones. A Finnish group was for a long period in the forefront of research on gastritis, and the authors' own studies on the classification of gastric cancer and the role of gastrin in the development of gastric neoplasia are of importance. It can, accordingly, be concluded that Nordic researchers have been central in the research on area of the upper gastrointestinal physiology and diseases.

  8. Fish cardiovascular physiology and disease.

    Science.gov (United States)

    Sherrill, Johanna; Weber, E Scott; Marty, Gary D; Hernandez-Divers, Stephen

    2009-01-01

    Fish patients with cardiovascular disorders present a challenge in terms of diagnostic evaluation and therapeutic options. Veterinarians can approach these cases in fish using methods similar to those employed for other companion animals. Clinicians who evaluate and treat fish in private, aquarium, zoologic, or aquaculture settings need to rely on sound clinical judgment after thorough historical and physical evaluation. Pharmacokinetic data and treatments specific to cardiovascular disease in fish are limited; thus, drug types and dosages used in fish are largely empiric. Fish cardiovascular anatomy, physiology, diagnostic evaluation, monitoring, common diseases, cardiac pathologic conditions, formulary options, and comprehensive references are presented with the goal of providing fish veterinarians with clinically relevant tools.

  9. Physiologic mastectomy via flank laparotomy.

    Science.gov (United States)

    Allen, Andrew J; Barrington, George M; Parish, Steve M

    2008-11-01

    Physiologic mastectomy can be used as a salvage procedure in cases of chronic suppurative mastitis, gangrenous mastitis, or chronic, severe mastitis associated with organisms liberating endotoxin or exotoxin. The surgical technique involves ligation of the major arterial blood supply (external pudendal artery) to the corresponding half of the mammary gland, which results in decreased systemic absorption of toxins and gland atrophy. The technique is performed with the cow standing, and it is relatively atraumatic. This procedure is a simple, yet effective alternative to radical mastectomy for unresponsive mastitis cases in genetically or otherwise valuable cattle.

  10. Bengt Saltin and exercise physiology: a perspective.

    Science.gov (United States)

    Joyner, Michael J

    2017-01-01

    This perspective highlights some of the key contributions of Professor Bengt Saltin (1935-2014) to exercise physiology. The emergence of exercise physiology from work physiology as his career began is discussed as are his contributions in a number of areas. Saltin's open and question-based style of leadership is a model for the future of our field.

  11. Electrocyte physiology: 50 years later.

    Science.gov (United States)

    Markham, Michael R

    2013-07-01

    Weakly electric gymnotiform and mormyrid fish generate and detect weak electric fields to image their worlds and communicate. These multi-purpose electric signals are generated by electrocytes, the specialized electric organ (EO) cells that produce the electric organ discharge (EOD). Just over 50 years ago the first experimental analyses of electrocyte physiology demonstrated that the EOD is produced and shaped by the timing and waveform of electrocyte action potentials (APs). Electrocytes of some species generate a single AP from a distinct region of excitable membrane, and this AP waveform determines EOD waveform. In other species, electrocytes possess two independent regions of excitable membrane that generate asynchronous APs with different waveforms, thereby increasing EOD complexity. Signal complexity is further enhanced in some gymnotiforms by the spatio-temporal activation of distinct EO regions with different electrocyte properties. For many mormyrids, additional EOD waveform components are produced by APs that propagate along stalks that connect postsynaptic regions to the main body of the electrocyte. I review here the history of research on electrocyte physiology in weakly electric fish, as well as recent discoveries of key phenomena not anticipated during early work in this field. Recent areas of investigation include the regulation of electrocyte activity by steroid and peptide hormones, the molecular evolution of electrocyte ion channels, and the evolutionary selection of ion channels expressed in excitable cells. These emerging research areas have generated renewed interest in electrocyte function and clear future directions for research addressing a broad range of new and important questions.

  12. The glycemic index: physiological significance.

    Science.gov (United States)

    Esfahani, Amin; Wong, Julia M W; Mirrahimi, Arash; Srichaikul, Korbua; Jenkins, David J A; Kendall, Cyril W C

    2009-08-01

    The glycemic index (GI) is a physiological assessment of a food's carbohydrate content through its effect on postprandial blood glucose concentrations. Evidence from trials and observational studies suggests that this physiological classification may have relevance to those chronic Western diseases associated with overconsumption and inactivity leading to central obesity and insulin resistance. The glycemic index classification of foods has been used as a tool to assess potential prevention and treatment strategies for diseases where glycemic control is of importance, such as diabetes. Low GI diets have also been reported to improve the serum lipid profile, reduce C-reactive protein (CRP) concentrations, and aid in weight control. In cross-sectional studies, low GI or glycemic load diets (mean GI multiplied by total carbohydrate) have been associated with higher levels of high-density lipoprotein cholesterol (HDL-C), with reduced CRP concentrations, and, in cohort studies, with decreased risk of developing diabetes and cardiovascular disease. In addition, some case-control and cohort studies have found positive associations between dietary GI and risk of various cancers, including those of the colon, breast, and prostate. Although inconsistencies in the current findings still need to be resolved, sufficient positive evidence, especially with respect to renewed interest in postprandial events, suggests that the glycemic index may have a role to play in the treatment and prevention of chronic diseases.

  13. Physiological Effects of Touching Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

    Full Text Available This study aimed to clarify the physiological effects of touching wood with the palm, in comparison with touching other materials on brain activity and autonomic nervous activity. Eighteen female university students (mean age, 21.7  ±  1.6 years participated in the study. As an indicator of brain activity, oxyhemoglobin (oxy-Hb concentrations were measured in the left/right prefrontal cortex using near-infrared time-resolved spectroscopy. Heart rate variability (HRV was used as an indicator of autonomic nervous activity. The high-frequency (HF component of HRV, which reflected parasympathetic nervous activity, and the low-frequency (LF/HF ratio, which reflected sympathetic nervous activity, were measured. Plates of uncoated white oak, marble, tile, and stainless steel were used as tactile stimuli. After sitting at rest with their eyes closed, participants touched the materials for 90 s. As a result, tactile stimulation with white oak significantly (1 decreased the oxy-Hb concentration in the left/right prefrontal cortex relative to marble, tile, and stainless steel and (2 increased ln(HF-reflected parasympathetic nervous activity relative to marble and stainless steel. In conclusion, our study revealed that touching wood with the palm calms prefrontal cortex activity and induces parasympathetic nervous activity more than other materials, thereby inducing physiological relaxation.

  14. Network Physiology: How Organ Systems Dynamically Interact.

    Science.gov (United States)

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

    2015-01-01

    We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS), we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  15. Network Physiology: How Organ Systems Dynamically Interact.

    Directory of Open Access Journals (Sweden)

    Ronny P Bartsch

    Full Text Available We systematically study how diverse physiologic systems in the human organism dynamically interact and collectively behave to produce distinct physiologic states and functions. This is a fundamental question in the new interdisciplinary field of Network Physiology, and has not been previously explored. Introducing the novel concept of Time Delay Stability (TDS, we develop a computational approach to identify and quantify networks of physiologic interactions from long-term continuous, multi-channel physiological recordings. We also develop a physiologically-motivated visualization framework to map networks of dynamical organ interactions to graphical objects encoded with information about the coupling strength of network links quantified using the TDS measure. Applying a system-wide integrative approach, we identify distinct patterns in the network structure of organ interactions, as well as the frequency bands through which these interactions are mediated. We establish first maps representing physiologic organ network interactions and discover basic rules underlying the complex hierarchical reorganization in physiologic networks with transitions across physiologic states. Our findings demonstrate a direct association between network topology and physiologic function, and provide new insights into understanding how health and distinct physiologic states emerge from networked interactions among nonlinear multi-component complex systems. The presented here investigations are initial steps in building a first atlas of dynamic interactions among organ systems.

  16. Neuronal responses to physiological stress

    DEFF Research Database (Denmark)

    Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger David John

    2012-01-01

    by changes in the environment. Fluctuations in oxygen levels, temperature, and redox state for example, trigger molecular events that enable an organism to adapt, survive, and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner...... include changes in the expression of molecules such as transcription factors and microRNAs that regulate stress resistance and adaptation. Moreover, both intrinsic and extrinsic stresses have a tremendous impact on neuronal development and maintenance with implications in many diseases. Here, we review......Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. It can be divided into three different aspects: environmental stress, intrinsic developmental stress, and aging. Throughout life all living organisms are challenged...

  17. CH2 - Lighting and Physiology

    Directory of Open Access Journals (Sweden)

    Sergio Altomonte

    2012-11-01

    Full Text Available This paper explains the designed performances of the new CH2 building in Melbourne, Australia. CH2 is an environmentally significant project that involves biomimicry of natural systems to produce indoor conditions that are conducive to user comfort, health and productivity. This paper focuses on lighting and physiology and examines the solutions chosen for artificial and natural lighting and the likely effects these will have on building occupants. The purpose of the paper is to critically comment on the adopted strategy and, cognisance of contemporary thinking in lighting design, to judge the effectiveness of this aspect of the project with a view to later verification and post-occupancy review. The paper concludes that CH2 is an exemplar of lighting innovation that provides valuable lessons to designers of office buildings, particularly in the Melbourne CSD.

  18. Children's physiological responses to childcare.

    Science.gov (United States)

    Vermeer, Harriet J; Groeneveld, Marleen G

    2017-06-01

    This review focuses on children's physiological responses to out-of-home childcare. The finding that children's cortisol levels are higher at childcare than at home has been well-replicated. Here we summarize recent evidence examining possible correlates of elevated cortisol levels. Reviewed studies suggest that childcare quality matters, whereas group sizes and type of care do not. As for child characteristics, elevated cortisol at childcare is more pronounced in toddlers than in infants, and in inhibited and aggressive children. We discuss recent advances focusing on hair cortisol analysis and immunomarkers of stress, and suggest that there is a need for experimental and longitudinal studies to examine causal relations and possible negative long-term consequences for children's health and development. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. CH2 - Lighting and Physiology

    Directory of Open Access Journals (Sweden)

    Sergio Altomonte

    2012-11-01

    Full Text Available This paper explains the designed performances of the new CH2 building in Melbourne, Australia. CH2 is an environmentally significant project that involves biomimicry of natural systems to produce indoor conditions that are conducive to user comfort, health and productivity. This paper focuses on lighting and physiology and examines the solutions chosen for artificial and natural lighting and the likely effects these will have on building occupants. The purpose of the paper is to critically comment on the adopted strategy and, cognisance of contemporary thinking in lighting design, to judge the effectiveness of this aspect of the project with a view to later verification and post-occupancy review. The paper concludes that CH2 is an exemplar of lighting innovation that provides valuable lessons to designers of office buildings, particularly in the Melbourne CSD.

  20. Ventricular hypertrophy--physiological mechanisms.

    Science.gov (United States)

    Vaughan Williams, E M

    1986-01-01

    Adult cardiac myocytes are incapable of mitosis. Dead cells are replaced by connective tissue so that after myocardial infarction (MI), function can only be restored by compensatory hypertrophy of the surviving myocardium. In physiological hypertrophy in response to exercise, high altitude, or mild hypertension, additional myoplasm expands cell diameter in an orderly fashion; Z-lines are in register and the normal ratio of volume densities of contractile elements, mitochondria, and capillaries is conserved. In hypertrophy induced by aortic or pulmonary artery banding or by experimental or congenital hypertension, the borderline between physiological and pathological hypertrophy may be crossed, causing disorganization of fibers and an unfavourable contractile element to capillary ratio. There was, therefore, a need for a graded model of hypertrophy, which involves simulating an altitude of 6,000 m at sea level by supplying rabbits with appropriate nitrogen/oxygen mixtures. In this environment, 50% right ventricular hypertrophy can be achieved without alteration of left ventricular weight or hematocrit. Longer exposures produced 100% right ventricular hypertrophy, with only moderate increases in hematocrit and left ventricular weight. It is well known that adrenergic stimulation causes cardiac hypertrophy, and it has been suggested that release of a trophic factor from sympathetic nerves, either noradrenaline or a protein, might be a necessary stimulus for growth. If so, long-term treatment of post-MI patients with beta-adrenergic blocking agents could inhibit a desirable compensatory hypertrophy of the surviving myocardium. In the above model it has been found, however, that neither beta-blockade nor chemical sympathectomy with guanethidine or 6-hydroxydopamine had any effect on the hypertrophy, nor did treatment with verapamil or nifedipine.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Fruit Calcium: Transport and Physiology

    Directory of Open Access Journals (Sweden)

    Bradleigh eHocking

    2016-04-01

    Full Text Available Calcium has well-documented roles in plant signaling, water relations and cell wall interactions. Significant research into how calcium impacts these individual processes in various tissues has been carried out; however, the influence of calcium on fruit ripening has not been thoroughly explored. Here, we review the current state of knowledge on how calcium may impact fruit development, physical traits and disease susceptibility through facilitating developmental and stress response signaling, stabilizing membranes, influencing water relations and modifying cell wall properties through cross-linking of de-esterified pectins. We explore the involvement of calcium in hormone signaling integral to ripening and the physiological mechanisms behind common disorders that have been associated with fruit calcium deficiency (e.g. blossom end rot in tomatoes or bitter pit in apples. This review works towards an improved understanding of how the many roles of calcium interact to influence fruit ripening, and proposes future research directions to fill knowledge gaps. Specifically, we focus mostly on grapes and present a model that integrates existing knowledge around these various functions of calcium in fruit, which provides a basis for understanding the physiological impacts of sub-optimal calcium nutrition in grapes. Calcium accumulation and distribution in fruit is shown to be highly dependent on water delivery and cell wall interactions in the apoplasm. Localized calcium deficiencies observed in particular species or varieties can result from differences in xylem morphology, fruit water relations and pectin composition, and can cause leaky membranes, irregular cell wall softening, impaired hormonal signaling and aberrant fruit development. We propose that the role of apoplasmic calcium-pectin crosslinking, particularly in the xylem, is an understudied area that may have a key influence on fruit water relations. Furthermore, we believe that improved

  2. Perbandingan Anestesi Xylazin-Ketamin Hidroklorida dengan Anestesi Tiletamin- Zolazepam terhadap Frekuensi Denyut Jantung dan Pulsus Anjing Lokal

    Directory of Open Access Journals (Sweden)

    Anak Agung Gde Oka Darmayudha

    2012-02-01

    Full Text Available A study to determine the effect of anesthesia xylazine- ketamine hydrochlorida withanesthesia tiletamine-zolazepam administration to heart pulse frequency and pulse duringanesthetion. The experimental was carried duct on local dog. The experimental design usewas a splite in time with 2 treatment : treatment I xylazin-ketamin ( 2 mg/Kg Body weightof xylazine ; 15 ing/Kg Body weight ketarnine and treatment II tiletamine-zolazepam ( 20mg/Kg Body weight. Each treatment use 5 dogs as refrain so we use 10 dogs for all of thetreatment. Obtain data is analized by various investigated test. Result of this study indicatedthat difference of treatment there were no significance, but time of the observed duringanesthesion showed more highly significance and significant to pulse frequency.

  3. Translational physiology: from molecules to public health.

    Science.gov (United States)

    Seals, Douglas R

    2013-07-15

    The term 'translational research' was coined 20 years ago and has become a guiding influence in biomedical research. It refers to a process by which the findings of basic research are extended to the clinical research setting (bench to bedside) and then to clinical practice and eventually health policy (bedside to community). It is a dynamic, multidisciplinary research approach. The concept of translational physiology applies the translational research model to the physiological sciences. It differs from the traditional areas of integrative and clinical physiology by its broad investigative scope of basic research to community health. Translational physiology offers exciting opportunities, but presently is under-developed and -utilized. A key challenge will be to expand physiological research by extending investigations to communities of patients and healthy (or at risk) individuals. This will allow bidirectional physiological investigation throughout the translational continuum: basic research observations can be studied up to the population level, and mechanisms can be assessed by 'reverse translation' in clinical research settings and preclinical models based on initial observations made in populations. Examples of translational physiology questions, experimental approaches, roadblocks and strategies for promotion are discussed. Translational physiology provides a novel framework for physiology programs and an investigational platform for physiologists to study function from molecular events to public health. It holds promise for enhancing the completeness and societal impact of our work, while further solidifying the critical role of physiology in the biomedical research enterprise.

  4. Early Cardiac Tamponade in a Patient with Postsurgical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Archana Sinha

    2015-01-01

    Full Text Available Pericardial effusion is a common cardiac manifestation of hypothyroidism, but effusion resulting in cardiac tamponade is extremely rare. We present a case of a 56-year-old African American woman with slurred speech and altered mental status that was initially suspected to have stroke. Her chest X-ray revealed cardiomegaly and subsequent echocardiogram showed a large pericardial effusion with echocardiographic evidence of cardiac tamponade. Clinically, patient did not have pulsus paradoxus or hypotension. Further questioning revealed a history of total surgical thyroidectomy and noncompliance with thyroid replacement therapy. Pericardiocentesis was performed promptly and thyroxine replacement therapy was started. Thereafter, her mental status improved significantly. The management of pericardial effusion associated with hypothyroidism varies depending on size of effusion and hemodynamic stability of the patient. The management strategy ranges from conservative management with close monitoring and thyroxine replacement to pericardiocentesis or creation of a pericardial window.

  5. Clinical diagnosis of tamponade in Malawi.

    Science.gov (United States)

    Round, A; Hamilton, W

    1990-07-01

    A consecutive series of 25 Malawian patients with tamponade secondary to tuberculosis were compared to 25 patients with congestive cardiac failure, without pericardial effusion in a retrospective study. More patients with tamponade had an impalpable apex beat (21/1), pulsus paradoxus (13/0), soft heart sounds (13/2), paradoxical rise in jugular venous pressure (6/0), and fewer had a murmur (1/14). All these results are significant (p less than 0.05) by the chi 2 test with Yates' correction. The presence of two or more of these discriminating physical signs has a positive predictive value of 75 per cent, and a negative predictive value of 99.5 per cent for the diagnosis of tamponade. Clinical diagnosis of tamponade by primary health care personnel in Malawi should be possible, and lead to earlier treatment.

  6. Intragroup Emotions: Physiological Linkage and Social Presence

    Science.gov (United States)

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

    2016-01-01

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

  7. Intragroup emotions: physiological linkage and social presence

    Directory of Open Access Journals (Sweden)

    Simo eJärvelä

    2016-02-01

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

  8. Wireless Sensor Network for Wearable Physiological Monitoring

    OpenAIRE

    P. S. Pandian; K. P. Safeer; Pragati Gupta; D. T. Shakunthala; B. S. Sundersheshu; V. C. Padaki

    2008-01-01

    Wearable physiological monitoring system consists of an array of sensors embedded into the fabric of the wearer to continuously monitor the physiological parameters and transmit wireless to a remote monitoring station. At the remote monitoring station the data is correlated to study the overall health status of the wearer. In the conventional wearable physiological monitoring system, the sensors are integrated at specific locations on the vest and are interconnected to the wearable data acqui...

  9. Auditory pathways: anatomy and physiology.

    Science.gov (United States)

    Pickles, James O

    2015-01-01

    This chapter outlines the anatomy and physiology of the auditory pathways. After a brief analysis of the external, middle ears, and cochlea, the responses of auditory nerve fibers are described. The central nervous system is analyzed in more detail. A scheme is provided to help understand the complex and multiple auditory pathways running through the brainstem. The multiple pathways are based on the need to preserve accurate timing while extracting complex spectral patterns in the auditory input. The auditory nerve fibers branch to give two pathways, a ventral sound-localizing stream, and a dorsal mainly pattern recognition stream, which innervate the different divisions of the cochlear nucleus. The outputs of the two streams, with their two types of analysis, are progressively combined in the inferior colliculus and onwards, to produce the representation of what can be called the "auditory objects" in the external world. The progressive extraction of critical features in the auditory stimulus in the different levels of the central auditory system, from cochlear nucleus to auditory cortex, is described. In addition, the auditory centrifugal system, running from cortex in multiple stages to the organ of Corti of the cochlea, is described.

  10. Virtual physiological human: training challenges.

    Science.gov (United States)

    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.

  11. Physiologic amputation: a case study.

    Science.gov (United States)

    Long, Jeri; Hall, Virginia

    2014-03-01

    Acute limb ischemia is a complication of severe peripheral arterial disease that can be a threatening limb as well as life. Multiple procedures exist today to help revascularize extremities; however, even with the latest technologies, surgical amputation of the limb may still be necessary. Cryoamputation, or physiologic amputation, is a method used to treat patients who are hemodynamically unstable for the operating room and who are in need of urgent amputation owing to arterial ischemia. This procedure is used in the rare instance where not only a persons' limb is threatened, but also their life. This is a case study regarding one patient who presented to the hospital with limb-threatening ischemia who became hemodynamically unstable owing to the rhabdomyolysis associated with the ischemia of his lower extremity. Cryoamputation was used to stabilize the patient and prevent further deterioration, so that he could safely undergo surgical amputation of the limb without an increase in mortality risk. Cryoamputation must be followed by formal surgical amputation when the patient is hemodynamically stabilized. It is not a limb salvaging, procedure but it is a life-saving procedure. This case study demonstrates the usefulness of the procedure and discusses the technique used for cryoamputation.

  12. Physiological demands of competitive basketball.

    Science.gov (United States)

    Narazaki, K; Berg, K; Stergiou, N; Chen, B

    2009-06-01

    The aim of this study was to assess physiological demands of competitive basketball by measuring oxygen consumption (VO2) and other variables during practice games. Each of 12 players (20.4 +/- 1.1 years) was monitored in a 20-min practice game, which was conducted in the same way as actual games with the presence of referees and coaches. VO2 was measured by a portable system during the game and blood lactate concentration (LA) was measured in brief breaks. Subjects were also videotaped for time-motion analysis. Female and male players demonstrated respective VO2 of 33.4 +/- 4.0 and 36.9 +/- 2.6 mL/kg/min and LA of 3.2 +/- 0.9 and 4.2 +/- 1.3 mmol/L in the practice games (P>0.05). They spent 34.1% of play time running and jumping, 56.8% walking, and 9.0% standing. Pre-obtained VO(2max) was correlated to VO(2) during play (r=0.673) and to percent of duration for running and jumping (r=0.935 and 0.962 for females and males, respectively). This study demonstrated a greater oxygen uptake for competitive basketball than that estimated based on a previous compendium. The correlation between aerobic capacity and activity level suggests the potential benefit of aerobic conditioning in basketball.

  13. Seasonal changes in reindeer physiology

    Directory of Open Access Journals (Sweden)

    A. Reeta Pösö

    2005-04-01

    Full Text Available The seasonal changes in the photoperiod, temperature and availability of food need to be converted to hormonal signals in order to induce adaptations in the physiology of the reindeer. The most reliable of the seasonal changes in the environment is the photoperiod, which affects the reindeer physiology through pineal gland and its hormone, melatonin. Usually there are large diurnal changes in the concentration of melatonin, but in the reindeer the daily rhythm disappears during the arctic summer to return again in the autumn. Seasonal changes in melatonin secretion are involved in the regulation of reproduction, the growth of pelage, thermogenesis, body mass and immune function. Melatonin may exert its effects through gene activation, but the mechanisms are not completely understood. Other hormones that show seasonality are thyroid hormones, insulin and leptin. Thus the observed physiological changes are a result of actions of several hormones. Appetite, energy production and thermogenesis are all vital for survival. During winter, when energy balance is negative, the reindeer uses mainly body fat for energy production. The use of fat stores is economical as the rate of lipolysis is controlled and the use of fatty acids in tissues such as muscle decreases. Only in severe starvation the rate of lipolysis increases enough to give rise to accumulation of ketone bodies. The protein mass is maintained and only in starved individuals muscle protein is used for energy production. The winter feed of the reindeer, the lichens, is poor in nitrogen and the nitrogen balance during winter is strongly negative. Reindeer responds to limited availability of nitrogen by increasing the recycling of urea into rumen. In general the adaptation of reindeer physiology enables the reindeer to survive the winter and although several aspects are known many others require further studies.Abstract in Finnish / Tiivistelmä: Valaistus, lämpötila ja ravinnon saatavuus

  14. Obesity and Asthma: Physiological Perspective

    Directory of Open Access Journals (Sweden)

    Bill Brashier

    2013-01-01

    Full Text Available Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC. Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma.

  15. Physiological factors influencing capillary growth.

    Science.gov (United States)

    Egginton, S

    2011-07-01

    (1) Angiogenesis (growth of new capillaries from an existing capillary bed) may result from a mismatch in microvascular supply and metabolic demand (metabolic error signal). Krogh examined the distribution and number of capillaries to explore the correlation between O(2) delivery and O(2) consumption. Subsequently, the heterogeneity in angiogenic response within a muscle has been shown to reflect either differences in fibre type composition or mechanical load. However, local control leads to targetted angiogenesis in the vicinity of glycolytic fibre types following muscle stimulation, or oxidative fibres following endurance training, while heterogeneity of capillary spacing is maintained during ontogenetic growth. (2) Despite limited microscopy resolution and lack of specific markers, Krogh's interest in the structure of the capillary wall paved the way for understanding the mechanisms of capillary growth. Angiogenesis may be influenced by the response of perivascular or stromal cells (fibroblasts, macrophages and pericytes) to altered activity, likely acting as a source for chemical signals modulating capillary growth such as vascular endothelial growth factor. In addition, haemodynamic factors such as shear stress and muscle stretch play a significant role in adaptive remodelling of the microcirculation. (3) Most indices of capillarity are highly dependent on fibre size, resulting in possible bias because of scaling. To examine the consequences of capillary distribution, it is therefore helpful to quantify the area of tissue supplied by individual capillaries. This allows the spatial limitations inherent in most models of tissue oxygenation to be overcome generating an alternative approach to Krogh's tissue cylinder, the capillary domain, to improve descriptions of intracellular oxygen diffusion. © 2010 The Author. Acta Physiologica © 2010 Scandinavian Physiological Society.

  16. Aristotle on physiology of logos

    Directory of Open Access Journals (Sweden)

    Benéitez Prudencio, José Javier

    2011-06-01

    Full Text Available This paper presents a view of Aristotle’s understanding of the relation of human intellect to human body. Given that for Aristotle intellect is a ‘psychic’ capacity or power: does Aristotle think of human understanding as a part or aspect of form (ειδος of the human body, in the way that the other powers (i.e. sensitive and nutritive are both parts of the form of an animal body? This question is still in dispute, but the objective in my inquiry is to justify the possibilities of an Aristotelian’s physiology of mind or thought.

    El presente artículo trata de estudiar la relación del entendimiento humano con el cuerpo en el pensamiento aristotélico. Dado que para Aristóteles la inteligencia constituye una capacidad o facultad ‘psíquica’, podríamos preguntarnos si no piensa, entonces, que sea una parte o un aspecto de la forma (ειδος del cuerpo humano, de la misma manera que se da esta relación con los otras facultades (así, por ejemplo, con la sensación y la nutrición. La cuestión es motivo todavía de disputa. El objetivo de mi investigación radica en justificar las posibilidades de una fisiología aristotélica de la mente o del pensamiento.

  17. Cardiac anatomy and physiology: a review.

    Science.gov (United States)

    Gavaghan, M

    1998-04-01

    This article reviews the normal anatomy and physiology of the heart. Understanding the normal anatomic and physiologic relationships described in this article will help perioperative nurses care for patients who are undergoing cardiac procedures. Such knowledge also assists nurses in educating patients about cardiac procedures and about activities that can prevent, reverse, or improve cardiac illness.

  18. Design Projects in Human Anatomy & Physiology

    Science.gov (United States)

    Polizzotto, Kristin; Ortiz, Mary T.

    2008-01-01

    Very often, some type of writing assignment is required in college entry-level Human Anatomy and Physiology courses. This assignment can be anything from an essay to a research paper on the literature, focusing on a faculty-approved topic of interest to the student. As educators who teach Human Anatomy and Physiology at an urban community college,…

  19. Teaching Stress Physiology Using Zebrafish ("Danio Rerio")

    Science.gov (United States)

    Cooper, Michael; Dhawale, Shree; Mustafa, Ahmed

    2009-01-01

    A straightforward and inexpensive laboratory experiment is presented that investigates the physiological stress response of zebrafish after a 5 degree C increase in water temperature. This experiment is designed for an undergraduate physiology lab and allows students to learn the scientific method and relevant laboratory techniques without causing…

  20. Physiological Coping: A Model for Teaching Pathophysiology

    Science.gov (United States)

    Porth, Carol M.

    1977-01-01

    The author discusses the use of a teaching model she developed for use in a pathophysiology. The model is based on the physiological component of C. Roy's adaptation model, which encourages students to look for physiological cues and apply relevant knowledge in patient care through a problem-solving approach. (TA)

  1. Physiology and biochemistry of honey bees

    Science.gov (United States)

    Despite their tremendous economic importance, honey bees are not a typical model system for studying general questions of insect physiology. This is primarily due to the fact that honey bees live in complex social settings which impact their physiological and biochemical characteristics. Not surpris...

  2. Towards Individualized Physiology Lecturing in Africa

    African Journals Online (AJOL)

    Dr Olaleye Samuel

    physiology slides, animations, diagrams and problem illustrations and real life case films in digital form. ... Patient-based physiology learning. Ripatti and Hänninen ... source leaving still a deeper cognitive understanding aside. This is to ... throughout the whole school time. ... now the on-line computerized systems provide.

  3. Physiological Bases of Bulimia, and Antidepressant Treatment.

    Science.gov (United States)

    Getzfeld, Andrew R.

    This paper reviews the literature on the physiological causes of bulimia and investigates the rationale behind the usage of antidepressant medication in the treatment of bulimia nervosa. No definite conclusions can be stated regarding the physiology of bulimia, but a number of hypotheses are suggested. It appears that the hypothalamus is involved…

  4. Design Projects in Human Anatomy & Physiology

    Science.gov (United States)

    Polizzotto, Kristin; Ortiz, Mary T.

    2008-01-01

    Very often, some type of writing assignment is required in college entry-level Human Anatomy and Physiology courses. This assignment can be anything from an essay to a research paper on the literature, focusing on a faculty-approved topic of interest to the student. As educators who teach Human Anatomy and Physiology at an urban community college,…

  5. Wireless Sensor Network for Wearable Physiological Monitoring

    Directory of Open Access Journals (Sweden)

    P. S. Pandian

    2008-05-01

    Full Text Available Wearable physiological monitoring system consists of an array of sensors embedded into the fabric of the wearer to continuously monitor the physiological parameters and transmit wireless to a remote monitoring station. At the remote monitoring station the data is correlated to study the overall health status of the wearer. In the conventional wearable physiological monitoring system, the sensors are integrated at specific locations on the vest and are interconnected to the wearable data acquisition hardware by wires woven into the fabric. The drawbacks associated with these systems are the cables woven in the fabric pickup noise such as power line interference and signals from nearby radiating sources and thereby corrupting the physiological signals. Also repositioning the sensors in the fabric is difficult once integrated. The problems can be overcome by the use of physiological sensors with miniaturized electronics to condition, process, digitize and wireless transmission integrated into the single module. These sensors are strategically placed at various locations on the vest. Number of sensors integrated into the fabric form a network (Personal Area Network and interacts with the human system to acquire and transmit the physiological data to a wearable data acquisition system. The wearable data acquisition hardware collects the data from various sensors and transmits the processed data to the remote monitoring station. The paper discusses wireless sensor network and its application to wearable physiological monitoring and its applications. Also the problems associated with conventional wearable physiological monitoring are discussed.

  6. Physiological Activity and Attitudes toward Disabled Persons.

    Science.gov (United States)

    Wesolowski, Michael D.; Deichmann, John

    1980-01-01

    Investigated whether physiological reactions of college students viewing videotapes showing three scene types (disabled people, able-bodied people, and neutral scenes) could be discriminated by scene type. Participants for the study were selected by their scores on the Attitudes toward Disabled Persons (ATDP) Scale. Physiological measures showed…

  7. Physiological characteristics of an aging Olympic athlete

    DEFF Research Database (Denmark)

    Nybo, Lars; Schmidt, Jakob Friis; Fritzdorf, Stephen;

    2014-01-01

    To investigate the physiological basis of continued world-class performance of a world-class rower who won medals (3 gold and 2 bronze) at five consecutive Olympic Games.......To investigate the physiological basis of continued world-class performance of a world-class rower who won medals (3 gold and 2 bronze) at five consecutive Olympic Games....

  8. Alterations in physiology and anatomy during pregnancy.

    Science.gov (United States)

    Tan, Eng Kien; Tan, Eng Loy

    2013-12-01

    Pregnant women undergo profound anatomical and physiological changes so that they can cope with the increased physical and metabolic demands of their pregnancies. The cardiovascular, respiratory, haematological, renal, gastrointestinal and endocrine systems all undergo important physiological alterations and adaptations needed to allow development of the fetus and to allow the mother and fetus to survive the demands of childbirth. Such alterations in anatomy and physiology may cause difficulties in interpreting signs, symptoms, and biochemical investigations, making the clinical assessment of a pregnant woman inevitably confusing but challenging. Understanding these changes is important for every practicing obstetrician, as the pathological deviations from the normal physiological alterations may not be clear-cut until an adverse outcome has resulted. Only with a sound knowledge of the physiology and anatomy changes can the care of an obstetric parturient be safely optimized for a better maternal and fetal outcome.

  9. The Effects Of An Exercise Physiology Program on Physical Fitness Variables, Body Satisfaction, and Physiology Knowledge.

    Science.gov (United States)

    Perry, Arlette C.; Rosenblatt, Evelyn S.; Kempner, Lani; Feldman, Brandon B.; Paolercio, Maria A.; Van Bemden, Angie L.

    2002-01-01

    Examined the effects of an exercise physiology program on high school students' physical fitness, body satisfaction, and physiology knowledge. Intervention students received exercise physiology theory and active aerobic and resistance exercise within their biology course. Data from student surveys and measurements indicated that the integrated…

  10. Determinants of physiological and perceived physiological stress reactivity in children and adolescents.

    Directory of Open Access Journals (Sweden)

    Brittany E Evans

    Full Text Available AIMS: Abnormal physiological stress reactivity is increasingly investigated as a vulnerability marker for various physical and psychological health problems. However, studies are inconsistent in taking into account potential covariates that may influence the developing stress system. We systematically tested determinants (individual, developmental, environmental and substance use-related of physiological and perceived physiological stress reactivity. We also examined the relation between physiological and perceived physiological stress reactivity. METHOD: In a stratified sample of 363 children (7-12 years and 344 adolescents (13-20 years from the general population, we examined cortisol, heart rate, respiratory sinus arrhythmia and perceived physiological stress reactivity to a psychosocial stress procedure. RESULTS: Using multivariate linear regression models, we found that individual, developmental, environmental and substance use-related factors were related to each of the stress response indices. These determinant factors were different for each of the stress reactivity indices, and different in children versus adolescents. Perceived physiological stress reactivity predicted cortisol reactivity in adolescents only. All other relations between perceived physiological and physiological stress reactivity were not significant. CONCLUSIONS: As physiological stress variables are often examined as vulnerability markers for the development of health problems, we maintain that it is essential that future studies take into consideration factors that may account for found relations. Our study provides an overview and indication of which variables should be considered in the investigation of the relation between physiological stress indices and illness.

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

    Science.gov (United States)

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

    2007-06-01

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

  12. Conceptual Learning: Enhancing Student Understanding of Physiology

    Science.gov (United States)

    Waltz, Micah J.

    Students are leaving undergraduate science programs without the knowledge and skills they are expected to have. This is apparent in professional programs, such as medical and veterinary school, where students do not possess the critical thinking skills necessary to be successful. Physiology is a required discipline for these professional programs and often before, as a pre-requisite. Physiology classrooms are an excellent place to teach critical thinking skills because the content consists of integrated processes. Therefore, in one study, it was investigated whether focusing on physiological concepts improved student understanding of physiology in both a non-physiological science course, Invertebrate Zoology, and in an undergraduate physiology course. An educational intervention was used in Invertebrate Zoology, where students were exposed to human physiology concepts that were similar to comparative physiology concepts they had learned during the semester. A pre-/post-test was used to assess learning gains. In a second study, the use of multimedia file usage was correlated to student exam scores in a physiology course. This was done to see if providing additional study materials that focused on specific concepts improved student understanding, as assessed using exam scores. Overall these studies indicate that encouraging assimilation of new concepts that expand upon material from lecture may help students gain a more complete understanding of a concept. The integration of these concepts into pre-existing conceptual frameworks may serve to teach students valuable critical thinking skills such as evaluation of new ideas within their current understanding and synthesizing the new content with the existing information. Focusing on this type of conceptual learning may enable students to apply content knowledge and think through problems. Additionally, focusing on concepts may enable students to improve their understanding of material without being overwhelmed by

  13. [Claude Bernard, founder of experimental physiology].

    Science.gov (United States)

    Ren, Y; Li, X; Xu, W

    2001-07-01

    Claude Bernard was a famous French physiologist and philosopher in the 19th century. His experimental researches almost involved all fields of physiology. It is generally recognized by physiologists that in the research of Bernard in the digestion of pancreas, glucogenesis in the liver, and the vasomotor mechanism and the mechanism of action of curari and carbon monoxide were all at the lead. His researches established the foundation for modern physiology, modern biochemistry and the works of Pavlov, and were the initiation of experimental physiology.

  14. An Author's Philosophy of Physiology Textbook Writing.

    Science.gov (United States)

    Guyton, Arthur C.

    1998-01-01

    Discusses the factors that have determined the author's approach to writing medical physiology textbooks. Reviews the author's career and the events surrounding the development of each textbook. Explains the motivation behind critical decisions made during the authoring process. (DDR)

  15. Three-dimensional printing physiology laboratory technology.

    Science.gov (United States)

    Sulkin, Matthew S; Widder, Emily; Shao, Connie; Holzem, Katherine M; Gloschat, Christopher; Gutbrod, Sarah R; Efimov, Igor R

    2013-12-01

    Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories.

  16. Neuroticism, Extraversion, Conscientiousness and Stress: Physiological Correlates

    NARCIS (Netherlands)

    Brouwer, Anne-Marie; van Schaik, Martin G.; Korteling, J.E. (Hans); van Erp, Johannes Bernardus Fransiscus; Toet, Alexander

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  17. Neuroticism, extraversion, conscientiousness and stress : Physiological correlates

    NARCIS (Netherlands)

    Brouwer, A.M.; Schaik, M.G. van; Korteling, J.E.; Erp, J.B.F. van; Toet, A.

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  18. Neuromodulators: available agents, physiology, and anatomy.

    Science.gov (United States)

    Nettar, Kartik; Maas, Corey

    2011-12-01

    Neuromodulators have risen to the forefront of aesthetic medicine. By reversibly relaxing target muscles, neuromodulators exhibit their effect by softening hyperfunctional lines. An understanding of their physiology, relevant facial anatomy, and current agents is imperative for a successful aesthetic practice.

  19. Neuroticism, extraversion, conscientiousness and stress : Physiological correlates

    NARCIS (Netherlands)

    Brouwer, A.M.; Schaik, M.G. van; Korteling, J.E.; Erp, J.B.F. van; Toet, A.

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  20. Some Recent Advances in Plant Physiology

    Science.gov (United States)

    Stafford, G. A.

    1972-01-01

    A popular review of plant physiological research, emphasizing those apsects of plant metabolism where there has been a recent shift in emphasis that is not yet reflected in secondary school advanced texts. (AL)

  1. Neuroticism, Extraversion, Conscientiousness and Stress: Physiological Correlates

    NARCIS (Netherlands)

    Brouwer, Anne-Marie; Schaik, van Martin G.; Korteling, J.E. (Hans); Erp, van Jan B.F.; Toet, Alexander

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming perf

  2. PHYSIOLOGICAL RESPONSES OF MEN DURING SLEEP DEPRIVATION,

    Science.gov (United States)

    The effects of 84 hours of sleep deprivation were examined in a group of six young men and compared with a group of six controls. Subjects were... sleep deprivation , physiological regulating systems are relatively unaffected by sleep loss. (Author)

  3. Physiology of the fetal and transitional circulation.

    Science.gov (United States)

    Finnemore, Anna; Groves, Alan

    2015-08-01

    The fetal circulation is an entirely transient event, not replicated at any point in later life, and functionally distinct from the pediatric and adult circulations. Understanding of the physiology of the fetal circulation is vital for accurate interpretation of hemodynamic assessments in utero, but also for management of circulatory compromise in premature infants, who begin extrauterine life before the fetal circulation has finished its maturation. This review summarizes the key classical components of circulatory physiology, as well as some of the newer concepts of physiology that have been appreciated in recent years. The immature circulation has significantly altered function in all aspects of circulatory physiology. The mechanisms and significance of these differences are also discussed, as is the impact of these alterations on the circulatory transition of infants born prematurely.

  4. Reproductive physiology of the male camelid.

    Science.gov (United States)

    Bravo, P W; Johnson, L W

    1994-07-01

    The physiology of reproduction with emphasis on endocrinology of llamas and alpacas is addressed. Information regarding male anatomy, puberty, testicular function, semen description, and sexual behavior is also included.

  5. An Author's Philosophy of Physiology Textbook Writing.

    Science.gov (United States)

    Guyton, Arthur C.

    1998-01-01

    Discusses the factors that have determined the author's approach to writing medical physiology textbooks. Reviews the author's career and the events surrounding the development of each textbook. Explains the motivation behind critical decisions made during the authoring process. (DDR)

  6. Neuroticism, Extraversion, Conscientiousness and Stress: Physiological Correlates

    NARCIS (Netherlands)

    Brouwer, Anne-Marie; van Schaik, Martin G.; Korteling, J.E. (Hans); van Erp, Johannes Bernardus Fransiscus; Toet, Alexander

    2015-01-01

    High extraversion and conscientiousness and low neuroticism predict successful performance during and after stressful conditions. We investigated whether these personality factors are linked to stress sensitivity and to baseline physiology. Stress was induced through negative feedback on gaming

  7. Physiological responses induced by pleasant stimuli.

    Science.gov (United States)

    Watanuki, Shigeki; Kim, Yeon-Kyu

    2005-01-01

    The specific physiological responses induced by pleasant stimuli were investigated in this study. Various physiological responses of the brain (encephaloelectrogram; EEG), autonomic nervous system (ANS), immune system and endocrine system were monitored when pleasant stimuli such as odors, emotional pictures and rakugo, a typical Japanese comical story-telling, were presented to subjects. The results revealed that (i) EEG activities of the left frontal brain region were enhanced by a pleasant odor; (ii) emotional pictures related to primitive element such as nudes and erotic couples elevated vasomotor sympathetic nervous activity; and (iii) an increase in secretory immunoglobulin A (s-IgA) and a decrease in salivary cortisol (s-cortisol) were induced by rakugo-derived linguistic pleasant emotion. Pleasant emotion is complicated state. However, by considering the evolutionary history of human being, it is possible to assess and evaluate pleasant emotion from certain physiological responses by appropriately summating various physiological parameters.

  8. Physiological, Psychological, and Social Effects of Noise

    Science.gov (United States)

    Kryter, K. D.

    1984-01-01

    The physiological, and behavioral effects of noise on man are investigated. Basic parameters such as definitions of noise, measuring techniques of noise, and the physiology of the ear are presented prior to the development of topics on hearing loss, speech communication in noise, social effects of noise, and the health effects of noise pollution. Recommendations for the assessment and subsequent control of noise is included.

  9. Physiological and Growth Characteristics of Shewanella Species

    Science.gov (United States)

    2016-05-01

    282–287. 29. Dawood B. 1998. Corrosion-enhancing potential of Shewanella putrefaciens isolated from industrial cooling waters. J Appl Microbiol. 84...AFCEC-CX-TY-TR-2016-0016 PHYSIOLOGICAL AND GROWTH CHARACTERISTICS OF SHEWANELLA SPECIES Karen Farrington, D. Matthew Eby, Susan Sizemore...Technical Report 01 March 2012 - 01 March 2014 Physiological and growth characteristics of Shewanella species FA4819-11-C-0003 Karen Farrington (1

  10. Phage Therapy: Eco-Physiological Pharmacology

    OpenAIRE

    Abedon, Stephen T.

    2014-01-01

    Bacterial virus use as antibacterial agents, in the guise of what is commonly known as phage therapy, is an inherently physiological, ecological, and also pharmacological process. Physiologically we can consider metabolic properties of phage infections of bacteria and variation in those properties as a function of preexisting bacterial states. In addition, there are patient responses to pathogenesis, patient responses to phage infections of pathogens, and also patient responses to phage virio...

  11. Computers in Some Branches of Applied Physiology .

    Directory of Open Access Journals (Sweden)

    S.S. Verma

    1994-04-01

    Full Text Available This paper reviews the applications of computers in the evaluation of different types of problems occuring in some branches of applied physiology. The recent applications of computers to perform advanced multivariate regression analysis for developing regression models in applied physiology are also highlighted. The regression models are practical significance for screening personnel in defence services, mines, industrial works, sports and the like.

  12. Coronary physiology assessment in the catheterization laboratory

    Institute of Scientific and Technical Information of China (English)

    Felipe; Díez-delhoyo; Enrique; Gutiérrez-Iba?es; Gerard; Loughlin; Ricardo; Sanz-Ruiz; María; Eugenia; Vázquez-álvarez; Fernando; Sarnago-Cebada; Rocío; Angulo-Llanos; Ana; Casado-Plasencia; Jaime; Elízaga; Francisco; Fernández; Avilés; Diáz

    2015-01-01

    Physicians cannot rely solely on the angiographic appearance of epicardial coronary artery stenosis when evaluating patients with myocardial ischemia. Instead, sound knowledge of coronary vascular physiology and of the methods currently available for its characterization can improve the diagnostic and prognostic accuracy of invasive assessment of the coronary circulation, and help improve clinical decision-making. In this article we summarize the current methods available for a thorough assessment of coronary physiology.

  13. Anatomy and physiology of the stomach.

    Science.gov (United States)

    Soybel, David I

    2005-10-01

    In this article, key concepts in gastric anatomy and physiology are reviewed. Attention is given to historical development of concepts of acid secretion, to the role of stomach in digestion, and to the mechanisms that protect gastric mucosa from acid and hostile luminal conditions. Evolving ideas that may influence understand-ing of the physiologic consequences of emerging therapeutics, and procedures that target anatomy or function of the stomach are also reviewed.

  14. A Brief History of Bacterial Growth Physiology

    Directory of Open Access Journals (Sweden)

    Moselio eSchaechter

    2015-04-01

    Full Text Available Arguably, microbial physiology started when Leeuwenhoek became fascinated by observing a Vorticella beating its cilia, my point being that almost any observation of microbes has a physiological component. With the advent of modern microbiology in the mid 19th century, the field became recognizably distinctive with such discoveries as anaerobiosis, fermentation as a biological phenomenon, and the nutritional requirements of microbes. Soon came the discoveries of Winogradsky and his followers of the chemical changes in the environment that result from microbial activities. Later, during the first half of the 20th century, microbial physiology became the basis for much of the elucidation of central metabolism.Bacterial physiology then became a handmaiden of molecular biology and was greatly influenced by the discovery of cellular regulatory mechanisms. Microbial growth, which had come of age with the early work of Hershey, Monod, and others, was later pursued by studies on a whole cell level by what became known as the Copenhagen School. During this time, the exploration of physiological activities became coupled to modern inquiries into the structure of the bacterial cell.Recent years have seen the development of a further phase in microbial physiology, one seeking a deeper quantitative understanding of phenomena on a whole cell level. This pursuit is exemplified by the emergence of systems biology, which is made possible by the development of technologies that permit the gathering of information in huge amounts. As has been true through history, the research into microbial physiology continues to be guided by the development of new methods of analysis. Some of these developments may well afford the possibility of making stunning breakthroughs.

  15. A brief history of bacterial growth physiology.

    Science.gov (United States)

    Schaechter, Moselio

    2015-01-01

    Arguably, microbial physiology started when Leeuwenhoek became fascinated by observing a Vorticella beating its cilia, my point being that almost any observation of microbes has a physiological component. With the advent of modern microbiology in the mid-19th century, the field became recognizably distinctive with such discoveries as anaerobiosis, fermentation as a biological phenomenon, and the nutritional requirements of microbes. Soon came the discoveries of Winogradsky and his followers of the chemical changes in the environment that result from microbial activities. Later, during the first half of the 20th century, microbial physiology became the basis for much of the elucidation of central metabolism. Bacterial physiology then became a handmaiden of molecular biology and was greatly influenced by the discovery of cellular regulatory mechanisms. Microbial growth, which had come of age with the early work of Hershey, Monod, and others, was later pursued by studies on a whole cell level by what became known as the "Copenhagen School." During this time, the exploration of physiological activities became coupled to modern inquiries into the structure of the bacterial cell. Recent years have seen the development of a further phase in microbial physiology, one seeking a deeper quantitative understanding of phenomena on a whole cell level. This pursuit is exemplified by the emergence of systems biology, which is made possible by the development of technologies that permit the gathering of information in huge amounts. As has been true through history, the research into microbial physiology continues to be guided by the development of new methods of analysis. Some of these developments may well afford the possibility of making stunning breakthroughs.

  16. Database of Physiological Parameters for Early Life Rats and Mice

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Database of Physiological Parameters for Early Life Rats and Mice provides information based on scientific literature about physiological parameters. Modelers...

  17. Physiological responses to daily light exposure

    Science.gov (United States)

    Yang, Yefeng; Yu, Yonghua; Yang, Bo; Zhou, Hong; Pan, Jinming

    2016-04-01

    Long daylength artificial light exposure associates with disorders, and a potential physiological mechanism has been proposed. However, previous studies have examined no more than three artificial light treatments and limited metabolic parameters, which have been insufficient to demonstrate mechanical responses. Here, comprehensive physiological response curves were established and the physiological mechanism was strengthened. Chicks were illuminated for 12, 14, 16, 18, 20, or 22 h periods each day. A quadratic relationship between abdominal adipose weight (AAW) and light period suggested that long-term or short-term light exposure could decrease the amount of AAW. Quantitative relationships between physiological parameters and daily light period were also established in this study. The relationships between triglycerides (TG), cholesterol (TC), glucose (GLU), phosphorus (P) levels and daily light period could be described by quadratic regression models. TG levels, AAW, and BW positively correlated with each other, suggesting long-term light exposure significantly increased AAW by increasing TG thus resulting in greater BW. A positive correlation between blood triiodothyronine (T3) levels and BW suggested that daily long-term light exposure increased BW by thyroid hormone secretion. Though the molecular pathway remains unknown, these results suggest a comprehensive physiological mechanism through which light exposure affects growth.

  18. Epigenetics and transgenerational transfer: a physiological perspective.

    Science.gov (United States)

    Ho, D H; Burggren, W W

    2010-01-01

    Epigenetics, the transgenerational transfer of phenotypic characters without modification of gene sequence, is a burgeoning area of study in many disciplines of biology. However, the potential impact of this phenomenon on the physiology of animals is not yet broadly appreciated, in part because the phenomenon of epigenetics is not typically part of the design of physiological investigations. Still enigmatic and somewhat ill defined is the relationship between the overarching concept of epigenetics and interesting transgenerational phenomena (e.g. 'maternal/parental effects') that alter the physiological phenotype of subsequent generations. The lingering effect on subsequent generations of an initial environmental disturbance in parent animals can be profound, with genes continuing to be variously silenced or expressed without an associated change in gene sequence for many generations. Known epigenetic mechanisms involved in this phenomenon include chromatin remodeling (DNA methylation and histone modification), RNA-mediated modifications (non-coding RNA and microRNA), as well as other less well studied mechanisms such as self-sustaining loops and structural inheritance. In this review we: (1) discuss how the concepts of epigenetics and maternal effects both overlap with, and are distinct from, each other; (2) analyze examples of existing animal physiological studies based on these concepts; and (3) offer a construct by which to integrate these concepts into the design of future investigations in animal physiology.

  19. Cell volume regulation: physiology and pathophysiology

    DEFF Research Database (Denmark)

    Lambert, I H; Hoffmann, E K; Pedersen, Stine Helene Falsig

    2008-01-01

    not only under physiological conditions, e.g. following accumulation of nutrients, during epithelial absorption/secretion processes, following hormonal/autocrine stimulation, and during induction of apoptosis, but also under pathophysiological conditions, e.g. hypoxia, ischaemia and hyponatremia....../hypernatremia. On the other hand, it has recently become clear that an increase or reduction in cell volume can also serve as a specific signal in the regulation of physiological processes such as transepithelial transport, cell migration, proliferation and death. Although the mechanisms by which cell volume perturbations...... are sensed are still far from clear, significant progress has been made with respect to the nature of the sensors, transducers and effectors that convert a change in cell volume into a physiological response. In the present review, we summarize recent major developments in the field, and emphasize...

  20. Financial Anxiety, Physiological Arousal, and Planning Intention

    Directory of Open Access Journals (Sweden)

    John Grable

    2014-12-01

    Full Text Available Results from this exploratory clinical study indicate that financial anxiety—holding an unhealthy attitude about one’s financial situation—and physiological arousal—the physical precursor to behavior—play important roles in shaping consumer intention to engage in future financial planning activity. Findings suggest that those who are most likely to engage the services of a financial adviser exhibit low levels of financial anxiety and moderate to high levels of physiological arousal. The least likely to seek the help of a financial adviser are those who exhibit high financial anxiety and low physiological arousal. Results support findings documented in the literature that high anxiety levels often lead to a form of self-imposed helplessness. In order to move those experiencing financial anxiety towards financial solutions, financial advisers ought to take steps to simultaneously reduce financial stressors and stimulate arousal as a way to promote behavioral change and help seeking.

  1. From growth physiology to systems biology.

    Science.gov (United States)

    Schaechter, Moselio

    2006-09-01

    As it focuses on the integrated behavior of the entire cell, systems biology is a powerful extension of growth physiology. Here, I briefly trace some of the origins of modern-day bacterial growth physiology and its relevance to systems biology. I describe how growth physiology emerged from the foggy picture of the growth curve as a self-contained entity. For this insight, we can thank Henrici, Hershey, Monod, Maaløe, and others. As a result of their work, growth rate is understood to be the unitary manifestation of the response to nutritional conditions and to the control condition for studies on the effect of environmental stresses. For this response to be usefully reproducible, cultures must be in the steady state known as balanced growth. I point out that present-day experimenters are not always aware of this imperative and thus do not always use conditions that ensure the balanced growth of their control cultures.

  2. Physiological assessment of long pepper seeds

    Directory of Open Access Journals (Sweden)

    Francisco Pacheco Júnior

    2015-12-01

    Full Text Available The environmental and economic potential of long pepper (Piper hispidinervum requires the development of methodology to evaluate seed potential physiological. The work aimed to evaluate the physiological potential of long pepper seeds (Piper hispidinervum C. DC. through different tests and accelerated aging. Seeds were harvested in four different commercial planting and evaluated to water content (%, germination (G%, germination speed index (GSI, seedling emergence (SE%, emergence rate index (ERI and accelerated aging (AA 41 and 45 °C during 24, 48, 72 and 96 hours. The experimental design was completely randomized with a simple scheme for G, GSI, SE and ERI, and 4 x 4 factorial (lots and times at each temperature for AA. Physiological potential of long pepper seeds can be evaluated by germination test, germination speed index, seedling emergence, seedlings emergence speed index and accelerated aging at 41 °C during 24 hours.

  3. New concept of physiologic anchorage control

    Directory of Open Access Journals (Sweden)

    Tian-Min Xu

    2015-01-01

    Full Text Available Molar anchorage loss in extraction case is believed due to the reaction of mechanical force applied to retract anterior teeth. While it may be close to truth in adult patients, it is certainly not true in adolescents. Studies on molar growth show upper molar move forward as mandible growing forward, probably through intercuspation force. Hence, for adolescents, molar anchorage loss shall consist of two parts. One is from retraction force - mechanical anchorage loss; another from biologic force - physiologic anchorage loss. Since physiologic anchorage loss is caused by the continuous biologic force, the strategy of physiologic anchorage control (PAC is different from the strategy of mechanical anchorage control. A new PAC method is introduced in this article that can reduce the headgear and temporary anchorage device used as sagittal anchorage dramatically in orthodontic clinic.

  4. Improving the physiological realism of experimental models.

    Science.gov (United States)

    Vinnakota, Kalyan C; Cha, Chae Y; Rorsman, Patrik; Balaban, Robert S; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A; Jeneson, Jeroen A L

    2016-04-06

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these models rely on the analysis and integration of experimental data. As such, the success of VPH depends on the availability of physiologically realistic experimental models (E-Models) of human organ function that can be parametrized to test the numerical models. Here, the current state of suitable E-models, ranging from in vitro non-human cell organelles to in vivo human organ systems, is discussed. Specifically, challenges and recent progress in improving the physiological realism of E-models that may benefit the VPH project are highlighted and discussed using examples from the field of research on cardiovascular disease, musculoskeletal disorders, diabetes and Parkinson's disease.

  5. [The role of physiology in modern surgery].

    Science.gov (United States)

    2006-04-01

    Through the analysis of recent achievements in the field of surgery we have demonstrated convincingly that physiological studies in both humans and animal models are the keystone of modern surgery. Physiological studies of blood circulation, respiration, digestion and other functions have laid the foundations for major fields of surgery. Their role is the most evident in the development of cardiac surgery. Notably, one of the outstanding breakthroughs in the medical science of the 20th century--the extracorporeal blood circulation--was made by the Russian physiologist S. S. Bryukhovenko. We have shown that noninvasive diagnostic procedures such as echocardiography are of outmost significance on all stages of the surgical treatment (pre- and intraoperational diagnostics and medical rehabilitation). The great impact of physiology on the development of surgery has also led to the progress of related fields of medicine--anesthesiology, intensive care, functional diagnostics, transplantation, rehabilitation, and many others.

  6. Physiologic basis for understanding quantitative dehydration assessment.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W; Charkoudian, Nisha; Sawka, Michael N

    2013-03-01

    Dehydration (body water deficit) is a physiologic state that can have profound implications for human health and performance. Unfortunately, dehydration can be difficult to assess, and there is no single, universal gold standard for decision making. In this article, we review the physiologic basis for understanding quantitative dehydration assessment. We highlight how phenomenologic interpretations of dehydration depend critically on the type (dehydration compared with volume depletion) and magnitude (moderate compared with severe) of dehydration, which in turn influence the osmotic (plasma osmolality) and blood volume-dependent compensatory thresholds for antidiuretic and thirst responses. In particular, we review new findings regarding the biological variation in osmotic responses to dehydration and discuss how this variation can help provide a quantitative and clinically relevant link between the physiology and phenomenology of dehydration. Practical measures with empirical thresholds are provided as a starting point for improving the practice of dehydration assessment.

  7. [Autopharmacology, sloths and physiology. Opinions on certain historical aspects and potential developments in physiology in Liege].

    Science.gov (United States)

    Damas, J

    2001-07-01

    We recall the works of Bacq, Lecomte and Goffart, three physiologists from the University of Liège, on neurohumoral transmission, autacoids, sloths and monkeys in order to stress first that Physiology is a natural science of its own, and secondly that physiological studies aim at the understanding of the general mechanisms concurring to homeostasis.

  8. The XIIIth International Physiological Congress in Boston in 1929: American Physiology Comes of Age

    Science.gov (United States)

    Rall, Jack A.

    2016-01-01

    In the 19th century, the concept of experimental physiology originated in France with Claude Bernard, evolved in Germany stimulated by the teaching of Carl Ludwig, and later spread to Britain and then to the United States. The goal was to develop a physicochemical understanding of physiological phenomena. The first International Physiological…

  9. Herpetological diversity along Andean elevational gradients: links with physiological ecology and evolutionary physiology.

    Science.gov (United States)

    Navas, Carlos A

    2002-11-01

    A well-defined macroecological pattern is the decline in biodiversity with altitude. However, this decline is taxa-specific. For example, amphibians are more diverse than squamates at extreme elevations in the tropical Andes, but this pattern is reversed at extreme elevations in the southern latitudes. Several ecophysiological and evolutionary factors may be related to this difference. At high-elevations in southern latitudes temperature differs dramatically among seasons and dry soils dominate, characteristics that appear to favor lizard physiological ecology. Tropical high altitudes, in contrast, are humid and offer abundant and diverse water resources. These characteristics allow for a richer anuran community but might complicate lizard egg development through temperature and oxygen constrains. Differences in strategies of thermal adaptation might also modulate diversity patterns. The thermal physiology of anurans is extremely labile so that behavioral and physiological performance is maintained despite an altitudinal decrease in field body temperature. Lizards, in contrast, exhibit a conservative thermal physiology and rely on behavioral thermoregulation to face cold and variable temperatures. Both, lizard behavioral strategies and anuran physiological adjustments seem equally efficient in allowing ecological success and diversification for both groups in the tropics up to approximately 3000 m. At higher elevations physiological thermal adaptation is required, and lizards are ecologically constrained, perhaps at various ontogenetic stages. Patterns of biodiversity along environmental clines can be better understood through a physiological approach, and can help to refine and propose hypotheses in evolutionary physiology.

  10. [Space physiology and psychology: long missions].

    Science.gov (United States)

    Lazorthes, G

    1989-06-01

    Until now spatial physiology and medicine concern mainly disturbances caused by life in microgravity during short stay (days, weeks). Neuro-sensorial, cardiovascular, osteo-muscular manifestations are well known; their prophylaxis is in great part established. It is shortly speak of them. Consequence of long stay (months or years) are not so well known; they are physiologic and psychologic. These long flights are now rare but they would probably be more numerous in next future. Authors present successively physics dangers: radiations, meteorites, composition of screw, number and selective tests, alimentation, fry time, habitation, biologic rhythms, psychism... We meet the same psychologic problems as great explorations have known.

  11. Signal Processing of Random Physiological Signals

    CERN Document Server

    Lessard, Charles

    2006-01-01

    Signal Processing of Random Physiological Signals presents the most widely used techniques in signal and system analysis. Specifically, the book is concerned with methods of characterizing signals and systems. Author Charles Lessard provides students and researchers an understanding of the time and frequency domain processes which may be used to evaluate random physiological signals such as brainwave, sleep, respiratory sounds, heart valve sounds, electromyograms, and electro-oculograms.Another aim of the book is to have the students evaluate actual mammalian data without spending most or all

  12. Physiological Disorders in Closed, Controlled Environment Crops

    Science.gov (United States)

    Wheeler, Raymond M.; Morrow, Robert C.

    2010-01-01

    This slide presentation reviews some of the physiological disorders that affect crops grown in closed controlled environments. A physiological disorder is understood to be a problem resulting from the influence of environmental and horticultural factors on plan development other than a problem caused by a pathogen or some other abiotic cause. The topics that are addressed are: (1) Calcium-Related Disorders (2) Oedema (Intumescence) (3) Long-Photoperiod Injury (4) Light Spectral Quality Effects (5) Super-Elevated CO2 Injuries (6) Ethylene (7) Other Disorders (8) Considerations for Closed Space Environments. Views of plant with the disorders are shown.

  13. Cardiovascular physiology and diseases of amphibians.

    Science.gov (United States)

    Heinz-Taheny, Kathleen M

    2009-01-01

    The class Amphibia includes three orders of amphibians: the anurans (frogs and toads), urodeles (salamanders, axolotls, and newts), and caecilians. The diversity of lifestyles across these three orders has accompanying differences in the cardiovascular anatomy and physiology allowing for adaptations to aquatic or terrestrial habitats, pulmonic or gill respiration, hibernation, and body elongation (in the caecilian). This article provides a review of amphibian cardiovascular anatomy and physiology with discussion of unique species adaptations. In addition, amphibians as cardiovascular animal models and commonly encountered natural diseases are covered.

  14. Concepts of Human Physiology in Ayurveda

    OpenAIRE

    Patwardhan, Dr. Kishor

    2008-01-01

    ‘Human Physiology’, or the study of functional aspects of human body, is designated by the term ‘Śarīra Vicaya’ in Ayurvedic literature. The word ‘Vicaya’ means the special or detailed knowledge. Detailed knowledge of normal human body i.e., ‘Śarīra’, is considered helpful in understanding the factors influencing the health. Though most of the basic concepts of human physiology explained in Ayurveda are strikingly similar to the concepts of modern physiology, some concepts like ‘Ātmā’, ‘Ma...

  15. Task Differences, Stylistic Characteristics and Physiological Arousal.

    Science.gov (United States)

    1983-08-01

    responses in Type A and B subjects. Journal of Applied Social Psychology , 1979, 9, 209-228. Dembroski, T. M., MacDougall, J. M. and Shields, J. L...C. and Denson, A. L. Information load stress, risk taking and physiological responsivity in a visual-motor task. Journal of Applied Social Psychology , 1983

  16. The Physiology of Fear and Sound

    DEFF Research Database (Denmark)

    Garner, Tom Alexander; Grimshaw, Mark

    2013-01-01

    The potential value of a looping biometric feedback system as a key component of adaptive computer video games is significant. Psychophysiological measures are essential to the development of an automated emotion recognition program, capable of interpreting physiological data into models of affec...

  17. Physiologic and pharmacokinetic changes in pregnancy.

    Science.gov (United States)

    Costantine, Maged M

    2014-01-01

    Physiologic changes in pregnancy induce profound alterations to the pharmacokinetic properties of many medications. These changes affect distribution, absorption, metabolism, and excretion of drugs, and thus may impact their pharmacodynamic properties during pregnancy. Pregnant women undergo several adaptations in many organ systems. Some adaptations are secondary to hormonal changes in pregnancy, while others occur to support the gravid woman and her developing fetus. Some of the changes in maternal physiology during pregnancy include, for example, increased maternal fat and total body water, decreased plasma protein concentrations, especially albumin, increased maternal blood volume, cardiac output, and blood flow to the kidneys and uteroplacental unit, and decreased blood pressure. The maternal blood volume expansion occurs at a larger proportion than the increase in red blood cell mass, which results in physiologic anemia and hemodilution. Other physiologic changes include increased tidal volume, partially compensated respiratory alkalosis, delayed gastric emptying and gastrointestinal motility, and altered activity of hepatic drug metabolizing enzymes. Understating these changes and their profound impact on the pharmacokinetic properties of drugs in pregnancy is essential to optimize maternal and fetal health.

  18. The concept of function in modern physiology.

    Science.gov (United States)

    Roux, Etienne

    2014-06-01

    An overview of the scientific literature shows that the concept of function is central in physiology. However, the concept itself is not defined by physiologists. On the other hand, the teleological, namely, the 'goal-directed' dimension of function, and its subsequent explanatory relevance, is a philosophical problem. Intuitively, the function of a trait in a system explains why this trait is present, but, in the early 1960s, Ernest Nagel and Carl Hempel have shown that this inference cannot be logically founded. However, they showed that self-regulated systems are teleological. According to the selectionist theories, the function of an item is its effect that has been selected by natural selection, a process that explains its presence. As they restrict the functional attribution of a trait to its past selective value and not its current properties, these theories are inconsistent with the concept of function in physiology. A more adequate one is the causal role theory, for which a function of a trait in a system is its causal contribution to the functional capacity of the system. However, this leaves unsolved the question of the 'surplus meaning' of the teleological dimension of function. The significance of considering organisms as 'purpose-like' (teleological) systems may reside not in its explanatory power but in its methodological fruitfulness in physiology. In this view, the teleological dimension of physiological functions is convergent to but not imported from, the teleological dimension of evolutionary biology.

  19. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY:

    Science.gov (United States)

    Twenty-one participants from Europe, North America and China convened in Chongqing, China, October 12-14, 2005, for the Eighth International Symposium in Fish Physiology, Toxicology and Water Quality. The subject of the meeting was "Hypoxia in vertebrates: Comparisons of terrestr...

  20. Anatomy and physiology of genital organs - women.

    Science.gov (United States)

    Graziottin, Alessandra; Gambini, Dania

    2015-01-01

    "Anatomy is destiny": Sigmund Freud viewed human anatomy as a necessary, although not a sufficient, condition for understanding the complexity of human sexual function with a solid biologic basis. The aim of the chapter is to describe women's genital anatomy and physiology, focusing on women's sexual function with a clinically oriented vision. Key points include: embryology, stressing that the "female" is the anatomic "default" program, differentiated into "male" only in the presence of androgens at physiologic levels for the gestational age; sex determination and sex differentiation, describing the interplay between anatomic and endocrine factors; the "clitoral-urethral-vaginal" complex, the most recent anatomy reading of the corpora cavernosa pattern in women; the controversial G spot; the role of the pelvic floor muscles in modulating vaginal receptivity and intercourse feelings, with hyperactivity leading to introital dyspareunia and contributing to provoked vestibulodynia and recurrent postcoital cystitis, whilst lesions during delivery reduce vaginal sensations, genital arousability, and orgasm; innervation, vessels, bones, ligaments; and the physiology of women's sexual response. Attention to physiologic aging focuses on "low-grade inflammation," genital and systemic, with its impact on women sexual function, especially after the menopause, if the woman does not or cannot use hormone replacement therapy.

  1. Physiologic and Pharmacokinetic Changes in Pregnancy

    Directory of Open Access Journals (Sweden)

    Maged eCostantine

    2014-04-01

    Full Text Available Physiologic changes in pregnancy induce profound alterations to the pharmacokinetic properties of many medications. These changes affect distribution, absorption, metabolism, and excretion of drugs, and thus may impact their pharmacodynamic properties during pregnancy. Pregnant women undergo several adaptations in many organ systems. Some adaptations are secondary to hormonal changes in pregnancy, while others occur to support the gravid woman and her developing fetus. Some of the changes in maternal physiology during pregnancy include, for example, increased maternal fat and total body water, decreased plasma protein concentrations, especially albumin, increased maternal blood volume, cardiac output and blood flow to the kidneys and uteroplacental unit, and decreased blood pressure. The maternal blood volume expansion occurs at a larger proportion than the increase in red blood cell mass, which results in physiologic anemia and hemodilution. Other physiologic changes include increased tidal volume, partially compensated respiratory alkalosis, delayed gastric emptying and gastrointestinal motility, and altered activity of hepatic drug metabolizing enzymes. Understating these changes and their profound impact on the pharmacokinetic properties of drugs in pregnancy is essential to optimize maternal and fetal health.

  2. Electromyography physiology engineering and noninvasive applications

    CERN Document Server

    Parker, Philip; John Wiley & Sons

    2004-01-01

    "Featuring contributions from key innovators working in the field today, Electromyography reveals the broad applications of EMG data in areas as diverse as neurology, ergonomics, exercise physiology, rehabilitation, movement analysis, biofeedback, and myoelectric control of prostheses." "Electromyography offers physiologists, medical professionals, and students in biomedical engineering a new window into the possibilities of this technology."--Jacket.

  3. [Immune response genes products in human physiology].

    Science.gov (United States)

    Khaitov, R M; Alekseev, L P

    2012-09-01

    Current data on physiological role of human immune response genes' proteomic products (antigens) are discussed. The antigens are specified by a very high level of diversity that mediates a wide specter ofphysiological functions. They actually provide integrity and biological stability of human as species. These data reveal new ideas on many pathological processes as well as drafts new approaches for prophylaxis and treatment.

  4. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

    Vinnakota, Kalyan C.; Cha, Chae Y.; Rorsman, Patrik; Balaban, Robert S.; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A.; Jeneson, Jeroen A. L.

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these

  5. Physiological Disorders of Pear Shoot Cultures

    Science.gov (United States)

    Physiological disorders are some of the most difficult challenges in micropropagation. Little is known of the causes of plant growth disorders which include callus formation, hyperhydricity, shoot tip necrosis, leaf lesions, epinasty, fasciation and hypertrophy. During our study of mineral nutritio...

  6. Physiological considerations in radionuclide urodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, T.K.; Fink, S.; Burger, R.H.; Netto, I.C.; Palmer, J.D. (V.A. Medical Center, Hamptom, VA (USA))

    1989-01-01

    Radionuclear imaging of micturition (RNIM) (Nuclear Uroflowmetry, Voiding Nuclear Cystogram) measures bladder volumes, bladder emptying times, and urinary flow rates. These data help to differentiate normal subjects from those with obstructive uropathy or neuromuscular failure and to quantify the deficit. We discuss the physiological considerations of importance to physicians ordering and interpreting this convenient and noninvasive diagnostic procedure. 39 references.

  7. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY

    Science.gov (United States)

    Scientists from ten countries presented papers at the Fifth International Symposium on Fish Physiology, Toxicology, and Water Quality, which was held on the campus of the city University of Hong Kong on November 10-13, 1998. These Proceedings include 23 papers presented in sessi...

  8. Supporting Placement Supervision in Clinical Exercise Physiology

    Science.gov (United States)

    Sealey, Rebecca M.; Raymond, Jacqueline; Groeller, Herb; Rooney, Kieron; Crabb, Meagan; Watt, Kerrianne

    2015-01-01

    The continued engagement of the professional workforce as supervisors is critical for the sustainability and growth of work-integrated learning activities in university degrees. This study investigated factors that influence the willingness and ability of clinicians to continue to supervise clinical exercise physiology work-integrated learning…

  9. Preparing Prospective Physical Educators in Exercise Physiology.

    Science.gov (United States)

    Bulger, Sean M.; Mohr, Derek J.; Carson, Linda M.; Robert, Darren L.; Wiegand, Robert L.

    2000-01-01

    Addresses the need for continued assessment of course content and instructional methods employed within physical education teacher education programs to deliver theoretical and applied information from the foundational subdiscipline of exercise physiology, describing an innovative course at one university (Exercise for School-Aged Children) which…

  10. Myths and Truths from Exercise Physiology

    Science.gov (United States)

    Kieffer, H. Scott

    2008-01-01

    This article addresses some of the common myths in the field of exercise physiology. Some of the myths are misconstrued facts that have developed over time, such as the myth of localized fat reduction. Other myths are unproved or collective beliefs used to justify a social institution; we see this occur in the form of "fitness fads." Society is…

  11. Challenges in Exercise Physiology Research and Education

    Science.gov (United States)

    Ji, Li Li; Diffee, Gary; Schrage, William

    2008-01-01

    Similar to other subdisciplines in kinesiology, exercise physiology (EP) as a field is facing challenges in both research (creation and dissemination of new knowledge) and education (classroom instruction and student mentoring). In the current communication, we will learn from the history, analyze the current status of the field, and provide some…

  12. Teaching Physics in a Physiologically Meaningful Manner

    Science.gov (United States)

    Plomer, Michael; Jessen, Karsten; Rangelov, Georgi; Meyer, Michael

    2010-01-01

    The learning outcome of a physics laboratory course for medical students was examined in an interdisciplinary field study and discussed for the electrical physiology ("Propagation of Excitation and Nerve Cells"). At the Ludwig-Maximilians-University of Munich (LMU) at a time about 300 medicine students were assessed in two successive…

  13. Experienced and physiological fatigue in neuromuscular disorders.

    NARCIS (Netherlands)

    Schillings, M.L.; Kalkman, J.S.; Janssen, H.M.; Engelen, B.G.M. van; Bleijenberg, G.; Zwarts, M.J.

    2007-01-01

    OBJECTIVE: Fatigue has been described as a typical symptom of neurological diseases. It might be caused both by changes at the peripheral and at the central level. This study measured the level of experienced fatigue and physiological correlates of fatigue in three genetically defined neuromuscular

  14. Mechanisms of physiological and epileptic HFO generation

    NARCIS (Netherlands)

    Jefferys, J.G.; Menendez de la Prida, L.; Wendling, F.; Bragin, A.; Avoli, M.; Timofeev, I.; Lopes da Silva, F.H.

    2012-01-01

    High frequency oscillations (HFO) have a variety of characteristics: band-limited or broad-band, transient burst-like phenomenon or steady-state. HFOs may be encountered under physiological or under pathological conditions (pHFO). Here we review the underlying mechanisms of oscillations, at the leve

  15. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

    Vinnakota, Kalyan C.; Cha, Chae Y.; Rorsman, Patrik; Balaban, Robert S.; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A.; Jeneson, Jeroen A. L.

    2016-01-01

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these m

  16. Physiological consequences : Cardiopulmonary, vestibular, and sensory aspects

    NARCIS (Netherlands)

    Welsch, H.; Albery, W.; Banks, R.D.; Bles, W.

    2000-01-01

    Discussing the physiological consequences of enhanced fighter manoeuvrability (EFM), aspects of cardiopulmonary reactions will be seen during high G manoeuvres, especially the combination of negative G-load followed by high G-onset manoeuvres ("push-pull"). The aircraft's capability to reach high al

  17. Dehydration: physiology, assessment, and performance effects.

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W

    2014-01-01

    This article provides a comprehensive review of dehydration assessment and presents a unique evaluation of the dehydration and performance literature. The importance of osmolality and volume are emphasized when discussing the physiology, assessment, and performance effects of dehydration. The underappreciated physiologic distinction between a loss of hypo-osmotic body water (intracellular dehydration) and an iso-osmotic loss of body water (extracellular dehydration) is presented and argued as the single most essential aspect of dehydration assessment. The importance of diagnostic and biological variation analyses to dehydration assessment methods is reviewed and their use in gauging the true potential of any dehydration assessment method highlighted. The necessity for establishing proper baselines is discussed, as is the magnitude of dehydration required to elicit reliable and detectable osmotic or volume-mediated compensatory physiologic responses. The discussion of physiologic responses further helps inform and explain our analysis of the literature suggesting a ≥ 2% dehydration threshold for impaired endurance exercise performance mediated by volume loss. In contrast, no clear threshold or plausible mechanism(s) support the marginal, but potentially important, impairment in strength, and power observed with dehydration. Similarly, the potential for dehydration to impair cognition appears small and related primarily to distraction or discomfort. The impact of dehydration on any particular sport skill or task is therefore likely dependent upon the makeup of the task itself (e.g., endurance, strength, cognitive, and motor skill).

  18. The concept of function in modern physiology

    Science.gov (United States)

    Roux, Etienne

    2014-01-01

    An overview of the scientific literature shows that the concept of function is central in physiology. However, the concept itself is not defined by physiologists. On the other hand, the teleological, namely, the ‘goal-directed’ dimension of function, and its subsequent explanatory relevance, is a philosophical problem. Intuitively, the function of a trait in a system explains why this trait is present, but, in the early 1960s, Ernest Nagel and Carl Hempel have shown that this inference cannot be logically founded. However, they showed that self-regulated systems are teleological. According to the selectionist theories, the function of an item is its effect that has been selected by natural selection, a process that explains its presence. As they restrict the functional attribution of a trait to its past selective value and not its current properties, these theories are inconsistent with the concept of function in physiology. A more adequate one is the causal role theory, for which a function of a trait in a system is its causal contribution to the functional capacity of the system. However, this leaves unsolved the question of the ‘surplus meaning’ of the teleological dimension of function. The significance of considering organisms as ‘purpose-like’ (teleological) systems may reside not in its explanatory power but in its methodological fruitfulness in physiology. In this view, the teleological dimension of physiological functions is convergent to but not imported from, the teleological dimension of evolutionary biology. PMID:24882809

  19. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

    Doorn, van W.G.; Woltering, E.J.

    2008-01-01

    Petal senescence is reviewed, with the main emphasis on gene expression in relation to physiological functions. Autophagy seems to be the major mechanism for large-scale degradation of macromolecules, but it is still unclear if it contributes to cell death. Depending on the species, petal senescence

  20. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

    Doorn, van W.G.; Woltering, E.J.

    2008-01-01

    Petal senescence is reviewed, with the main emphasis on gene expression in relation to physiological functions. Autophagy seems to be the major mechanism for large-scale degradation of macromolecules, but it is still unclear if it contributes to cell death. Depending on the species, petal senescence

  1. [Heat and Fever in ancient Greek physiology].

    Science.gov (United States)

    Yeo, In-Sok

    2009-12-01

    This paper aims at clarifying the relationship of physiological heat and pathological heat(fever) using the theoretical scheme of Georges Canguilhem as is argued in his famous book The Normal and the Pathologic. Ancient authors had presented various views on the innate heat and pathological heat. Some argued that there is only pathological heat while others, like Galen, distinguished two different kinds of heat. Galen was the first medial author who had the clear notion of the relationship between the normal heat and the pathological heat. He conceptualized their difference as the heat conforming to nature (kata phusin) and the heat against nature (para phusin). However, the Peripatetic authors, such as ps-Alexander Aphrodisias, who laid more emphasis on physiology tended to regard pathology in continuation with physiology as Claude Bernard attempted to do it. Therefore, Canguilhem's theoretical scheme turns out to be very useful in analysing the relationship of normal heat and pathological heat as is manifested in ancient Greek physiology.

  2. Anatomy and Physiology. Revised Teacher Edition.

    Science.gov (United States)

    Hartman, Danene; And Others

    This curriculum guide contains 14 units of instruction for a course in anatomy and physiology for surgical technology students. The units cover the following topics: (1) organization of the body; (2) cells, tissues, and membranes; (3) integumentary system; (4) skeletal system; (5) muscular system; (6) nervous system; (7) special sense organs; (8)…

  3. Physiological functions of MTA family of proteins.

    Science.gov (United States)

    Sen, Nirmalya; Gui, Bin; Kumar, Rakesh

    2014-12-01

    Although the functional significance of the metastasic tumor antigen (MTA) family of chromatin remodeling proteins in the pathobiology of cancer is fairly well recognized, the physiological role of MTA proteins continues to be an understudied research area and is just beginning to be recognized. Similar to cancer cells, MTA1 also modulates the expression of target genes in normal cells either by acting as a corepressor or coactivator. In addition, physiological functions of MTA proteins are likely to be influenced by its differential expression, subcellular localization, and regulation by upstream modulators and extracellular signals. This review summarizes our current understanding of the physiological functions of the MTA proteins in model systems. In particular, we highlight recent advances of the role MTA proteins play in the brain, eye, circadian rhythm, mammary gland biology, spermatogenesis, liver, immunomodulation and inflammation, cellular radio-sensitivity, and hematopoiesis and differentiation. Based on the growth of knowledge regarding the exciting new facets of the MTA family of proteins in biology and medicine, we speculate that the next burst of findings in this field may reveal further molecular regulatory insights of non-redundant functions of MTA coregulators in the normal physiology as well as in pathological conditions outside cancer.

  4. Evolutionary plant physiology: Charles Darwin's forgotten synthesis

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J.

    2009-11-01

    Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin’s son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin’s work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.

  5. Physiological Sociology. Endocrine Correlates of Status Behaviors,

    Science.gov (United States)

    1975-01-01

    Behavior. J. Spuhler (Ed.). Chicago: Aldine Press, pp. 135-170, 1967. Hare, R. D. Psychopathy ’ Theory and Research. New York: Wiley-Interscience, 1970...Hare, R. D. Psychophathy and physiological responses to adrenalin. J. Abnorm. Psychol. 79:138-147, 1972. Hare, R. D. and Quinn, M. J. Psychopathy and

  6. From Dietary Fiber to Host Physiology

    DEFF Research Database (Denmark)

    Koh, Ara; De Vadder, Filipe; Kovatcheva-Datchary, Petia

    2016-01-01

    A compelling set of links between the composition of the gut microbiota, the host diet, and host physiology has emerged. Do these links reflect cause-and-effect relationships, and what might be their mechanistic basis? A growing body of work implicates microbially produced metabolites as crucial...

  7. Physiological basis for residual feed intake

    National Research Council Canada - National Science Library

    Herd, R. M; Arthur, P. F

    2009-01-01

    ...{at}dpi.nsw.gov.au Residual feed intake (RFI) is a measure of feed efficiency that is independent of level of production, such as size and growth rate in beef cattle, and thus is a useful new trait for studying the physiological mechanisms...

  8. Physiology of Exercise in the Cold

    Science.gov (United States)

    1991-01-01

    working i 25.5"C water, Rapp GM. Convection coefficients of man in a forensic area ofbreathing air or helium tri-mix. Jourial of Applied Physiology thermal...Jones RJ, Lahiri A, Cashman PMM, Dore C, Raftery EB. Left man at rest and during exercise. Medicina dello Sport 24: 223- ventricular function during

  9. Using measures of single-cell physiology and physiological state to understand organismic aging.

    Science.gov (United States)

    Mendenhall, Alexander; Driscoll, Monica; Brent, Roger

    2016-02-01

    Genetically identical organisms in homogeneous environments have different lifespans and healthspans. These differences are often attributed to stochastic events, such as mutations and 'epimutations', changes in DNA methylation and chromatin that change gene function and expression. But work in the last 10 years has revealed differences in lifespan- and health-related phenotypes that are not caused by lasting changes in DNA or identified by modifications to DNA or chromatin. This work has demonstrated persistent differences in single-cell and whole-organism physiological states operationally defined by values of reporter gene signals in living cells. While some single-cell states, for example, responses to oxygen deprivation, were defined previously, others, such as a generally heightened ability to make proteins, were, revealed by direct experiment only recently, and are not well understood. Here, we review technical progress that promises to greatly increase the number of these measurable single-cell physiological variables and measureable states. We discuss concepts that facilitate use of single-cell measurements to provide insight into physiological states and state transitions. We assert that researchers will use this information to relate cell level physiological readouts to whole-organism outcomes, to stratify aging populations into groups based on different physiologies, to define biomarkers predictive of outcomes, and to shed light on the molecular processes that bring about different individual physiologies. For these reasons, quantitative study of single-cell physiological variables and state transitions should provide a valuable complement to genetic and molecular explanations of how organisms age.

  10. "Physiology in the News": Using Press Releases to Enhance Lay Communication and Introduce Current Physiology Research to Undergraduates

    Science.gov (United States)

    Kelly, Kevin L.; Poteracki, James M.; Steury, Michael D.; Wehrwein, Erica A.

    2015-01-01

    Michigan State University's senior-level undergraduate physiology capstone laboratory uses a simple exercise termed "Physiology in the News," to help students explore the current research within the field of physiology while also learning to communicate science in lay terms. "Physiology in the News" is an activity that charges…

  11. Physiology Applied to Everyday: The Practice of Professional Contextualization of Physiology Concepts as a Way of Facilitating Learning

    Science.gov (United States)

    Borges, Sidnei; Mello-Carpes, Pâmela Billig

    2014-01-01

    The teaching of Physiology is indispensable in many biological and health disciplines. Physiology is one of the major components of the curriculum in a number of life science courses, including the study of life, cells, tissues, and organisms as well as their functions. A bigger challenge for physiology teachers is to make physiological concepts…

  12. Physiology Applied to Everyday: The Practice of Professional Contextualization of Physiology Concepts as a Way of Facilitating Learning

    Science.gov (United States)

    Borges, Sidnei; Mello-Carpes, Pâmela Billig

    2014-01-01

    The teaching of Physiology is indispensable in many biological and health disciplines. Physiology is one of the major components of the curriculum in a number of life science courses, including the study of life, cells, tissues, and organisms as well as their functions. A bigger challenge for physiology teachers is to make physiological concepts…

  13. The Open Physiology workflow: modeling processes over physiology circuitboards of interoperable tissue units

    Science.gov (United States)

    de Bono, Bernard; Safaei, Soroush; Grenon, Pierre; Nickerson, David P.; Alexander, Samuel; Helvensteijn, Michiel; Kok, Joost N.; Kokash, Natallia; Wu, Alan; Yu, Tommy; Hunter, Peter; Baldock, Richard A.

    2015-01-01

    A key challenge for the physiology modeling community is to enable the searching, objective comparison and, ultimately, re-use of models and associated data that are interoperable in terms of their physiological meaning. In this work, we outline the development of a workflow to modularize the simulation of tissue-level processes in physiology. In particular, we show how, via this approach, we can systematically extract, parcellate and annotate tissue histology data to represent component units of tissue function. These functional units are semantically interoperable, in terms of their physiological meaning. In particular, they are interoperable with respect to [i] each other and with respect to [ii] a circuitboard representation of long-range advective routes of fluid flow over which to model long-range molecular exchange between these units. We exemplify this approach through the combination of models for physiology-based pharmacokinetics and pharmacodynamics to quantitatively depict biological mechanisms across multiple scales. Links to the data, models and software components that constitute this workflow are found at http://open-physiology.org/. PMID:25759670

  14. Distinguishing hyperhidrosis and normal physiological sweat production

    DEFF Research Database (Denmark)

    Thorlacius, Linnea; Gyldenløve, Mette; Zachariae, Claus

    2015-01-01

    BACKGROUND: Hyperhidrosis is a condition in which the production of sweat is abnormally increased. No objective criteria for the diagnosis of hyperhidrosis exist, mainly because reference intervals for normal physiological sweat production at rest are unknown. OBJECTIVE: The main objective...... of this study was to establish reference intervals for normal physiological axillary and palmar sweat production. METHODS: Gravimetric testing was performed in 75 healthy control subjects. Subsequently, these results were compared with findings in a cohort of patients with hyperhidrosis and with the results...... derived from a review of data on hyperhidrosis published between 1980 and 2013. RESULTS: Approximately 90% of the controls had axillary and palmar sweat production rates of below 100 mg/5 min. In all except one of the axillary and palmar hyperhidrosis studies reviewed, average sweat production exceeded...

  15. Ventricular assist device in univentricular heart physiology.

    Science.gov (United States)

    Brancaccio, Gianluca; Gandolfo, Fabrizio; Carotti, Adriano; Amodeo, Antonio

    2013-04-01

    The use of mechanical cardiac assistance is well established as a bridge to orthotopic heart transplantation (OHT) or to recovery for patients with congestive heart failure, however, the experience in single ventricle (SV) physiology is still limited. We report two cases of mechanical assistance in patients with SV physiology: a 2-year old male with hypoplastic left heart syndrome who underwent Norwood Stage I and II followed by HF and a 4-year old female with a univentricular heart who developed a severe right ventricular dysfunction 2 years after a cavopulmonary shunt. Mechanical support utilizing ventricular assist devices (VADs) is considered a valid tool to bridge patients with congestive heart failure to either OHT or to recovery. Increasing experience and improved outcomes utilizing this technology in children with biventricular hearts have led to considering employing these devices in failing SV treatment. We present 2 cases of terminally ill children with SV who were assisted with a VAD.

  16. Predictors of success in undergraduate human physiology.

    Science.gov (United States)

    McCleary, V L; Aasen, G; Slotnick, H B

    1999-12-01

    This study tested the hypothesis that measurable attributes in students' backgrounds are related to their successful completion of an undergraduate human physiology course. Demographic, general academic performance, and science achievement data were obtained from student records for students enrolled during the 1995-1996 academic year, and additional demographic data were obtained from students enrolled during the 1996-1998 academic years. A hierarchical logistic regression analysis explored the relationship fo these variables to the percentage of students passing the human physiology course. Predicted passing versus failing showed a sensitivity of 85.5% and specificity of 69.7%. Two independent validations of the logistical regression equation correctly predicted the performance of subsequent groups of students 75.9% and 77.6% of the time.

  17. Tissue physiology and the response to heat

    DEFF Research Database (Denmark)

    Horsman, Michael Robert

    2006-01-01

    heating is terminated, perfusion and oxygenation commonly recover, although how quickly this occurs appears to be tumour-specific. While these effects are unlikely to have any anti-tumour activity they can be exploited to improve the combination of heat with other therapies. However, since similar......The most important physiological parameter influencing tissue response to heat is blood flow. At mild hyperthermia temperatures blood perfusion increases in many tumours and this effect is heating time-, temperature- and tumour-dependent. These flow increases can improve tumour oxygenation. When...... physiological effects should occur in normal tissues, such combination therapies must be carefully applied. Heating tumours to higher temperatures typically causes a transient increase in perfusion during heating, followed by vascular collapse which if sufficient will increase tumour necrosis. The speed...

  18. A Physiologically Inspired Method for Audio Classification

    Directory of Open Access Journals (Sweden)

    David V. Anderson

    2005-06-01

    Full Text Available We explore the use of physiologically inspired auditory features with both physiologically motivated and statistical audio classification methods. We use features derived from a biophysically defensible model of the early auditory system for audio classification using a neural network classifier. We also use a Gaussian-mixture-model (GMM-based classifier for the purpose of comparison and show that the neural-network-based approach works better. Further, we use features from a more advanced model of the auditory system and show that the features extracted from this model of the primary auditory cortex perform better than the features from the early auditory stage. The features give good classification performance with only one-second data segments used for training and testing.

  19. MEGen: A Physiologically Based Pharmacokinetic Model Generator

    Directory of Open Access Journals (Sweden)

    George D Loizou

    2011-11-01

    Full Text Available Physiologically based pharmacokinetic models are being used in an increasing number of different areas. These not only include the human safety assessment of pharmaceuticals, pesticides, biocides and environmental chemicals but also for food animal, wild mammal and avian risk assessment. The value of PBPK models is that they are tools for estimating tissue dosimetry by integrating in vitro and in vivo mechanistic, pharmacokinetic and toxicological information through their explicit mathematical description of important anatomical, physiological and biochemical determinants of chemical uptake, disposition and elimination. However, PBPK models are perceived as complex, data hungry, resource intensive and time consuming. In addition, model validation and verification are hindered by the relative complexity of the equations. To begin to address these issues a freely available web application for the rapid construction and documentation of bespoke PBPK models is under development. Here we present an overview of the current capabilities of MEGen, a model equation generator and parameter database and discuss future developments.

  20. Hearables: Multimodal physiological in-ear sensing

    CERN Document Server

    Goverdovsky, Valentin; Nakamura, Takashi; Looney, David; Sharp, David J; Papavassiliou, Christos; Morrell, Mary J; Mandic, Danilo P

    2016-01-01

    Future health systems require the means to assess and track the neural and physiological function of a user over long periods of time and in the community. Human body responses are manifested through multiple modalities, such as the mechanical, electrical and chemical; yet current physiological monitors (actigraphy, heart rate) largely lack in both the desired cross-modal and non-stigmatizing aspects. We address these challenges through an inconspicuous and comfortable earpiece, equipped with miniature multimodal sensors, which benefits from the relatively stable position of the ear canal with respect to vital organs to robustly measure the brain, cardiac and respiratory functions. Comprehensive experiments validate each modality within the proposed earpiece, while its potential in health monitoring is illustrated through case studies. We further demonstrate how combining data from multiple sensors within such an integrated wearable device improves both the accuracy of measurements and the ability to deal wit...

  1. Polydextrose: Physiological Function, and Effects on Health

    Directory of Open Access Journals (Sweden)

    Mariane Moreira Ramiro do Carmo

    2016-09-01

    Full Text Available Polydextrose (PDX is a non-digestible oligosaccharide used widely across most sectors of the food industry. It is a randomly linked glucose oligomer containing small amounts of sorbitol and citric acid. The random bonds in PDX prevent mammalian digestive enzymes from readily hydrolyzing the molecule and it has a reported energy value of 1 kcal/g. These properties have led to the acceptance in many countries that PDX provides similar physiological effects as other dietary fibers and has shown prebiotic potential. Dietary intervention with prebiotics has been shown to selectively stimulate the growth and/or activity of one or a limited number of intestinal bacteria associated with several physiological benefits on health. Therefore, the objective of this review was a survey of the literature on the effect of supplementation with PDX in health, and to list the benefits for maintaining health and/or reducing the development of diseases.

  2. Obesity: physiologic changes and challenges during laparoscopy.

    Science.gov (United States)

    Lamvu, Georgine; Zolnoun, Denniz; Boggess, John; Steege, John F

    2004-08-01

    The purpose of this report was to describe the evidence for the benefits of laparoscopic surgery in obese patients, to review the physiologic abnormalities that are associated with obesity, and to explore surgical techniques that will enable surgeons to perform laparoscopy successfully in obese patients. This article is a review of the available literature on obesity, the physiologic changes that occur in obese patients, and the impact of these changes on laparoscopy outcomes. Obesity is associated with sudden death and a wide range of morbid conditions such as hypertension, atherosclerosis, angina, chronic obstructive disease, and diabetes mellitus. Recent studies have demonstrated that obese patients who undergo laparoscopy have shorter hospital stays, less postoperative pain, and fewer wound infections when compared with obese patients who undergo laparotomy. Laparoscopy patients also have fewer postoperative ileus and fevers. With thorough preparation and careful preoperative evaluation, laparoscopy can be performed safely and is the preferred surgical method in obese patients.

  3. Bioactive lipids in kidney physiology and pathophysiology

    Directory of Open Access Journals (Sweden)

    Daria Sałata

    2014-01-01

    Full Text Available Lipids not only have structural functions, but also play an important role as signaling and regulatory molecules and participate in many cellular processes such as proliferation, differentiation, migration, and apoptosis. Bioactive lipids act both as extracellular mediators, which are associated with receptors on the surface of cells, and intracellular mediators triggering different signal pathways. They are present and active in physiological conditions, and are also involved in the pathogenesis of inflammation, asthma, cancer, diabetes, and hypertension. Bioactive lipids such as derivatives of arachidonic acid and sphingolipids have an important role in renal development, physiology and in many renal diseases. Some of them are potential indicators of kidney damage degree and/or function of the transplanted kidneys.

  4. Fostering improved anatomy and physiology instructor pedagogy.

    Science.gov (United States)

    Mattheis, Allison; Jensen, Murray

    2014-12-01

    Despite widespread calls for reform in undergraduate science, technology, engineering, and mathematics education, effecting lasting change in instructor practice is challenging to achieve. This article describes the results of a 2-yr research study that involved efforts to develop the pedagogical expertise of a group of anatomy and physiology instructors at the college level. Data were collected through a series of individual interviews that included the use of the Teacher Beliefs Inventory questionnaire (23) along with observations onsite in participants' college classrooms and at process-oriented guided inquiry learning (POGIL) curriculum writing workshops. Findings indicated attitudinal shifts on the part of participants from teacher-centered to more student-centered pedagogy and supported the benefits of long-term professional development for instructors. Here, we documented the successful progress of these professors as they participated in a curriculum development process that emphasized student-centered teaching with the goal of promoting broader change efforts in introductory anatomy and physiology.

  5. Application of molecular biology in exercise physiology.

    Science.gov (United States)

    Booth, F W

    1989-01-01

    Past progress in exercise biochemical research has often depended on the use of knowledge and techniques which were originally reported from other disciplines. With the advent of newer methodologies in molecular biology, the purpose of this review has been to document the status of information gained from the application of molecular biological techniques to questions in exercise physiology. Furthermore, this review has speculated how new methods in molecular biology might be employed to answer classic questions in exercise physiology. A powerful revolution in science, that is, molecular biology, will provide new information about exercise mechanisms, which ideally will improve the training programs for elite athletes as well as continue to be associated with the public's interest in exercise training.

  6. Model parameters for simulation of physiological lipids

    Science.gov (United States)

    McGlinchey, Nicholas

    2016-01-01

    Coarse grain simulation of proteins in their physiological membrane environment can offer insight across timescales, but requires a comprehensive force field. Parameters are explored for multicomponent bilayers composed of unsaturated lipids DOPC and DOPE, mixed‐chain saturation POPC and POPE, and anionic lipids found in bacteria: POPG and cardiolipin. A nonbond representation obtained from multiscale force matching is adapted for these lipids and combined with an improved bonding description of cholesterol. Equilibrating the area per lipid yields robust bilayer simulations and properties for common lipid mixtures with the exception of pure DOPE, which has a known tendency to form nonlamellar phase. The models maintain consistency with an existing lipid–protein interaction model, making the force field of general utility for studying membrane proteins in physiologically representative bilayers. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26864972

  7. Polydextrose: Physiological Function, and Effects on Health

    Science.gov (United States)

    do Carmo, Mariane Moreira Ramiro; Walker, Julia Clara Leite; Novello, Daiana; Caselato, Valeria Maria; Sgarbieri, Valdemiro Carlos; Ouwehand, Arthur C.; Andreollo, Nelson Adami; Hiane, Priscila Aiko; dos Santos, Elisvânia Freitas

    2016-01-01

    Polydextrose (PDX) is a non-digestible oligosaccharide used widely across most sectors of the food industry. It is a randomly linked glucose oligomer containing small amounts of sorbitol and citric acid. The random bonds in PDX prevent mammalian digestive enzymes from readily hydrolyzing the molecule and it has a reported energy value of 1 kcal/g. These properties have led to the acceptance in many countries that PDX provides similar physiological effects as other dietary fibers and has shown prebiotic potential. Dietary intervention with prebiotics has been shown to selectively stimulate the growth and/or activity of one or a limited number of intestinal bacteria associated with several physiological benefits on health. Therefore, the objective of this review was a survey of the literature on the effect of supplementation with PDX in health, and to list the benefits for maintaining health and/or reducing the development of diseases. PMID:27618093

  8. Polydextrose: Physiological Function, and Effects on Health.

    Science.gov (United States)

    do Carmo, Mariane Moreira Ramiro; Walker, Julia Clara Leite; Novello, Daiana; Caselato, Valeria Maria; Sgarbieri, Valdemiro Carlos; Ouwehand, Arthur C; Andreollo, Nelson Adami; Hiane, Priscila Aiko; Dos Santos, Elisvânia Freitas

    2016-09-08

    Polydextrose (PDX) is a non-digestible oligosaccharide used widely across most sectors of the food industry. It is a randomly linked glucose oligomer containing small amounts of sorbitol and citric acid. The random bonds in PDX prevent mammalian digestive enzymes from readily hydrolyzing the molecule and it has a reported energy value of 1 kcal/g. These properties have led to the acceptance in many countries that PDX provides similar physiological effects as other dietary fibers and has shown prebiotic potential. Dietary intervention with prebiotics has been shown to selectively stimulate the growth and/or activity of one or a limited number of intestinal bacteria associated with several physiological benefits on health. Therefore, the objective of this review was a survey of the literature on the effect of supplementation with PDX in health, and to list the benefits for maintaining health and/or reducing the development of diseases.

  9. Tissue physiology and the response to heat

    DEFF Research Database (Denmark)

    Horsman, Michael Robert

    2006-01-01

    The most important physiological parameter influencing tissue response to heat is blood flow. At mild hyperthermia temperatures blood perfusion increases in many tumours and this effect is heating time-, temperature- and tumour-dependent. These flow increases can improve tumour oxygenation. When...... heating is terminated, perfusion and oxygenation commonly recover, although how quickly this occurs appears to be tumour-specific. While these effects are unlikely to have any anti-tumour activity they can be exploited to improve the combination of heat with other therapies. However, since similar...... physiological effects should occur in normal tissues, such combination therapies must be carefully applied. Heating tumours to higher temperatures typically causes a transient increase in perfusion during heating, followed by vascular collapse which if sufficient will increase tumour necrosis. The speed...

  10. Didactic tools for understanding respiratory physiology

    Science.gov (United States)

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

    2007-11-01

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

  11. Didactic tools for understanding respiratory physiology

    Energy Technology Data Exchange (ETDEWEB)

    Kehoe, P Donnelly; Bratovich, C; Perrone, Ms; Castells, L Mendez [Catedra de FisiologIa y BiofIsica - Facultad de Ingenieria - Universidad Nacional de Entre Rios - Ruta Provincial N011 Km. 10, 5 - Oro Verde C.P. 3101 - Entre Rios (Argentina)

    2007-11-15

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

  12. Physiological phenotyping of plants for crop improvement.

    Science.gov (United States)

    Ghanem, Michel Edmond; Marrou, Hélène; Sinclair, Thomas R

    2015-03-01

    Future progress in crop breeding requires a new emphasis in plant physiological phenotyping for specific, well-defined traits. Success in physiological phenotyping to identify parents for use in breeding efforts for improved cultivars has been achieved by employing a multi-tier screening approach with different levels of sophistication and trait resolution. Subsequently, cultivar development required an integrated mix of classical breeding approaches and one or more tiers of phenotyping to identify genotypes expressing the desired trait. The role of high throughput systems can be useful; here, we emphasize that this approach is likely to offer useful results at an initial tier of phenotyping and will need to be complemented with more directed tiers of phenotyping. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Surface electromyography physiology, engineering and applications

    CERN Document Server

    Farina, Dario

    2016-01-01

    The book presents a quantitative approach to the study and use of noninvasively detected electromyographic (EMG) signals, as well as their numerous applications in various aspects of the life sciences. Surface Electromyography: Physiology, Engineering, and Applications is an update of Electromyography: Physiology, Engineering, and Noninvasive Applications (Wiley-IEEE Press, 2004) and focuses on the developments that have taken place over the last decade. The first nine chapters deal with the generation, detection, understanding, interpretation, and modeling of EMG signals. Detection technology, with particular focus on EMG imaging techniques that are based on two-dimensional electrode arrays are also included in the first half of the book. The latter 11 chapters deal with applications, which range fro monitoring muscle fatigue, electrically elicited contractions, posture analysis, prevention of work-related and child-delivery-related neuromuscular disorders, ergonomics, movement analysis, physical therapy, ex...

  14. The physiological roles of primary phospholipase C.

    Science.gov (United States)

    Yang, Yong Ryoul; Follo, Matilde Y; Cocco, Lucio; Suh, Pann-Ghill

    2013-09-01

    The roles of phosphoinositide-specific phospholipase C (PLC) have been extensively investigated in diverse cell lines and pathological conditions. Among the PLC isozmes, primary PLCs, PLC-β and PLC-γ, are directly activated by receptor activation, unlike other secondary PLCs (PLC-ɛ, PLC-δ1, and PLC-η1). PLC-β isozymes are activated by G protein couple receptor and PLC-γ isozymes are activated by receptor tyrosine kinase (RTK). Primary PLCs are differentially expressed in different tissues, suggesting their specific roles in diverse tissues and regulate a variety of physiological and pathophysiological functions. Thus, dysregulation of phospholipases contributes to a number of human diseases and primary PLCs have been identified as therapeutic targets for prevention and treatment of diseases. Here we review the roles of primary PLCs in physiology and their impact in pathology. Copyright © 2012. Published by Elsevier Ltd.

  15. Physiologic and pharmacokinetic changes in pregnancy

    OpenAIRE

    2014-01-01

    Physiologic changes in pregnancy induce profound alterations to the pharmacokinetic properties of many medications. These changes affect distribution, absorption, metabolism, and excretion of drugs, and thus may impact their pharmacodynamic properties during pregnancy. Pregnant women undergo several adaptations in many organ systems. Some adaptations are secondary to hormonal changes in pregnancy, while others occur to support the gravid woman and her developing fetus. Some of the changes in ...

  16. Physiology of yeasts in alcoholic fermentation processes

    OpenAIRE

    Guimarães, Pedro M. R.

    2008-01-01

    Tese de Doutoramento em Engenharia Química e Biológica This thesis is focused on physiological aspects of the yeasts used in two alcoholic fermentation processes: primary brewing fermentation and fermentation of lactose (particularly lactose derived from cheese whey) to ethanol by recombinant Saccharomyces cerevisiae flocculent strains. The brewing fermentation is probably the most extensively studied alcoholic fermentation process. Nevertheless, developments in brewing tech...

  17. Anatomy and physiology of the upper airway.

    Science.gov (United States)

    Sahin-Yilmaz, Asli; Naclerio, Robert M

    2011-03-01

    The nose is the major portal of air exchange between the internal and external environment. The nose participates in the vital functions of conditioning inspired air toward a temperature of 37°C and 100% relative humidity, providing local defense and filtering inhaled particulate matter and gases. It also functions in olfaction, which provides both a defense and pleasure for the individual. Understanding normal physiology provides the basis for recognizing abnormalities.

  18. Physiological roles of mitochondrial reactive oxygen species

    OpenAIRE

    Sena, Laura A.; Chandel, Navdeep S.

    2012-01-01

    Historically, mitochondrial reactive oxygen species (mROS) were thought to exclusively cause cellular damage and lack a physiological function. Accumulation of ROS and oxidative damage have been linked to multiple pathologies, including neurodegenerative diseases, diabetes, cancer, and premature aging. Thus, mROS were originally envisioned as a necessary evil of oxidative metabolism, a product of an imperfect system. Yet few biological systems possess such flagrant imperfections, thanks to th...

  19. Chromatin remodeling in cardiovascular development and physiology

    OpenAIRE

    Han, Pei; Hang, Calvin T.; Yang, Jin; Chang, Ching-Pin

    2011-01-01

    Chromatin regulation provides an important means of controlling cardiac gene expression under different physiological and pathological conditions. Processes that direct the development of normal embryonic hearts and pathology of stressed adult hearts may share general mechanisms that govern cardiac gene expression by chromatin-regulating factors. These common mechanisms may provide a framework for us to investigate the interactions among diverse chromatin remodelers/modifiers and various tran...

  20. Status of Research in Underwater Physiology

    Science.gov (United States)

    1956-03-01

    9 2.3.1 Individual Differences in Susceptibility to Nitrogen Narcosis ...................... 9 2.3.2 Central Nervous System Effects...oxygen toxicity and nitrogen narcosis at higher pressures should be investigated. This report describing problems not yet solved in the broad field of...even convulsions, but also to the pharmacology of oxygeu toxicity and nitrogen narcosis , the physiology of respira- tory resistance and exercise, and

  1. Language learning - physiological and psychological aspects

    Directory of Open Access Journals (Sweden)

    Dorina Tarnoveanu

    2010-06-01

    Full Text Available There are several stages in the linguistic development of a child; he will not merely reproduce the sentences he hears, but a personal production is often noticed. Children do not acquire the grammar of their native language through theoretical teaching; exposure to the speaking community will lead to the acquisition of the grammatical structures of their language. Little is known about how little children acquire the rules of their native language; yet, we may distinguish between physiological and psychological aspects.

  2. PHYSIOLOGIC TRANSFUSION TRIGGERS AND MASSIVE TRANSFUSION

    OpenAIRE

    Tánczos Krisztián; Molnár Zsolt

    2013-01-01

    Blood transfusion is often a life saving intervention, but can also be harmful. Restrictive transfusion protocols have recently been developed with a post transfusion target haemoglobin level of 70–100 g/l. Whether haemoglobin level on its own is enough to guide our transfusion policy is an important issue. This review was aimed to look at other possible, so called physiological indicators of blood transfusion what clinicians can be used in addition to haemoglobin during their everyday practi...

  3. Physiological Demands of Flat Horse Racing Jockeys.

    Science.gov (United States)

    Cullen, SarahJane; OʼLoughlin, Gillian; McGoldrick, Adrian; Smyth, Barry; May, Gregory; Warrington, Giles D

    2015-11-01

    The physiological demands of jockeys during competition remain largely unknown, thereby creating challenges when attempting to prescribe sport-specific nutrition and training guidelines. The purpose of this study was to evaluate the physiological demands and energy requirements of jockeys during flat racing. Oxygen uptake (V[Combining Dot Above]O2) and heart rate (HR) were assessed in 18 male trainee jockeys during a race simulation trial on a mechanical horse racing simulator for the typical time duration to cover a common flat race distance of 1,400 m. In addition, 8 male apprentice jockeys participated in a competitive race, over distances ranging from 1,200 to 1,600 m, during which HR and respiratory rate (RR) were assessed. All participants performed a maximal incremental cycle ergometer test. During the simulated race, peak V[Combining Dot Above]O2 was 42.74 ± 5.6 ml·kg·min (75 ± 11% of V[Combining Dot Above]O2peak) and below the mean ventilatory threshold (81 ± 5% of V[Combining Dot Above]O2peak) reported in the maximal incremental cycle test. Peak HR was 161 ± 16 b·min (86 ± 7% of HRpeak). Energy expenditure was estimated as 92.5 ± 18.8 kJ with an associated value of 9.4 metabolic equivalents. During the competitive race trial, peak HR reached 189 ± 5 b·min (103 ± 4% of HRpeak) and peak RR was 50 ± 7 breaths per minute. Results suggest that horse racing is a physically demanding sport, requiring jockeys to perform close to their physiological limit to be successful. These findings may provide a useful insight when developing sport-specific nutrition and training strategies to optimally equip and prepare jockeys physically for the physiological demands of horse racing.

  4. Agreeableness, Extraversion, Stressor and Physiological Stress Response

    OpenAIRE

    Xiaoyuan Chu; Zhentao Ma; Yuan Li; Jing Han

    2015-01-01

    Based on the theoretical analysis, with first-hand data collection and using multiple regression models, this study explored the relationship between agreeableness, extraversion, stressor and stress response and figured out interactive effect of agreeableness, extraversion, and stressor on stress response. We draw on the following conclusions: (1) the interaction term of stressor (work) and agreeableness can negatively predict physiological stress response; (2) the interaction term of stresso...

  5. Physiologie de la reproduction = Physiology of reproduction

    OpenAIRE

    Legendre, Marc; JALABERT, B.

    1988-01-01

    Apart from a few species on which specific studies have been conducted (e.g. on the sexual cycle), most research on the physiology of reproduction in African inland waters fishes deals with four families : Cichlidae, Mugilidae, Clariidae and Anguillidae, due to their economic importance in fisheries and fishiculture. A detailed review of date on these four families is given after a brief summary of general knowledge concerning Teleostean fishes

  6. Ecstasy from a physiological point of view

    OpenAIRE

    Kaj Björkqvist

    1982-01-01

    The biological study of man is one of today's most rapidly advancing sciences. There is no reason for not utilizing these methodologies of research and the knowledge already gained when studying ecstasy and other similar religious phenomena. Drugs have been used in all parts of the world as an ecstasy technique. Since mental states and physiological correlates always accompany each other, it is obvious that the human mind can be affected by external means, for instance by drugs. But the oppos...

  7. Physiological Acceptance Criteria for Cold Weather Clothing

    Science.gov (United States)

    1991-04-01

    been shown to decrease (3, 8, 11, 17, 23, 29, 33). Fanger describes this relationship mathematically as: ts M 35.7 - 0.032(H/AD), where ts - mean...1982. 6. Fanger , P. 0. Conditions for thermal comfort. Introducticn of a general comfort equation. In: Physiological and Behavioral Temperature...Regulation, edited by J. D. Hardy, A. P. Gagge, and J. A. J. Stolwijk. Springfield, Il.- Charles C. Thomas, 1970, p. 152-176. 7. Fanger , P. 0. Ansessment of

  8. Physiologically important metal nanoparticles and their toxicity.

    Science.gov (United States)

    Sengupta, Jayeeta; Ghosh, Sourav; Datta, Poulami; Gomes, Aparna; Gomes, Antony

    2014-01-01

    Nanotechnology has been setting benchmarks for the last two decades, but the origins of this technology reach back to ancient history. Today, nanoparticles of both metallic and non-metallic origin are under research and development for applications in various fields of biology/therapeutics. Physiologically important metals are of concern because they are compatible with the human system in terms of absorption, assimilation, excretion, and side effects. There are several physiologically inorganic metals that are present in the human body with a wide range of biological activities. Some of these metals are magnesium, chromium, manganese, iron, cobalt, copper, zinc, selenium and molybdenum. These metals are synthesized in the form of nanoparticles by different physical and chemical methods. Physiologically important nanoparticles are currently under investigation for their bio-medical applications as well as for therapeutics. Along with the applicative aspects of nanoparticles, another domain that is of great concern is the risk assessment of these nanoparticles to avoid unnecessary hazards. It has been seen that these nanoparticles have been shown to possess toxicity in biological systems. Conventional physical and chemical methods of metal nanoparticle synthesis may be one possible reason for nanoparticle toxicity that can be overcome by synthesis of nanoparticles from biological sources. This review is an attempt to establish metal nanoparticles of physiological importance to be the best candidates for future nanotechnological tools and medicines, owing to the acceptability and safety in the human body. This can only be successful if these particles are synthesized with a better biocompatibility and low or no toxicity.

  9. Context-aware sensing of physiological signals.

    Science.gov (United States)

    Wu, Winston H; Batalin, Maxim A; Au, Lawrence K; Bui, Alex A T; Kaiser, William J

    2007-01-01

    Recent advancement in microsensor technology permits miniaturization of conventional physiological sensors. Combined with low-power, energy-aware embedded systems and low power wireless interfaces, these sensors now enable patient monitoring in home and workplace environments in addition to the clinic. Low energy operation is critical for meeting typical long operating lifetime requirements. Some of these physiological sensors, such as electrocardiographs (ECG), introduce large energy demand because of the need for high sampling rate and resolution, and also introduce limitations due to reduced user wearability. In this paper, we show how context-aware sensing can provide the required monitoring capability while eliminating the need for energy-intensive continuous ECG signal acquisition. We have implemented a wearable system based on standard widely-used handheld computing hardware components. This system relies on a new software architecture and an embedded inference engine developed for these standard platforms. The performance of the system is evaluated using experimental data sets acquired for subjects wearing this system during an exercise sequence. This same approach can be used in context-aware monitoring of diverse physiological signals in a patient's daily life.

  10. Cardiovascular anatomy and physiology in the female.

    Science.gov (United States)

    Wingate, S

    1997-12-01

    Important differences in male and female cardiovascular anatomy and physiology may account for many of the gender differences seen in various cardiac disease states. Predominant influences on female disease manifestations include (1) women's smaller body size, hence smaller hearts and smaller coronary vessels and (2) women's fluctuating levels of estrogen throughout their lifespan. Understanding these critical anatomic and physiologic differences allows the clinician to better predict and plan care for women. For example, knowing that women generally have a smaller body surface area than men allows one to better understand why men have higher creatine kinase (CK) values than do women--an important distinction when interpreting these values in the acute care setting. The fact that women's hearts and coronary vessels are generally smaller than men's also helps one understand why women have a higher in-hospital mortality than men post-coronary artery bypass graft surgery (see article by Allen in this issue for more detailed information on revascularization). These are only a few examples of the many opportunities that acute care nurses have to integrate their knowledge of anatomy and physiology into proactive planning for their female cardiac patients.

  11. Physiological roles of small RNA molecules.

    Science.gov (United States)

    Michaux, Charlotte; Verneuil, Nicolas; Hartke, Axel; Giard, Jean-Christophe

    2014-06-01

    Unlike proteins, RNA molecules have emerged lately as key players in regulation in bacteria. Most reviews hitherto focused on the experimental and/or in silico methods used to identify genes encoding small RNAs (sRNAs) or on the diverse mechanisms of these RNA regulators to modulate expression of their targets. However, less is known about their biological functions and their implications in various physiological responses. This review aims to compile what is known presently about the diverse roles of sRNA transcripts in the regulation of metabolic processes, in different growth conditions, in adaptation to stress and in microbial pathogenesis. Several recent studies revealed that sRNA molecules are implicated in carbon metabolism and transport, amino acid metabolism or metal sensing. Moreover, regulatory RNAs participate in cellular adaptation to environmental changes, e.g. through quorum sensing systems or development of biofilms, and analyses of several sRNAs under various physiological stresses and culture conditions have already been performed. In addition, recent experiments performed with Gram-positive and Gram-negative pathogens showed that regulatory RNAs play important roles in microbial virulence and during infection. The combined results show the diversity of regulation mechanisms and physiological processes in which sRNA molecules are key actors.

  12. Physical and physiological profiles of taekwondo athletes.

    Science.gov (United States)

    Bridge, Craig A; Ferreira da Silva Santos, Jonatas; Chaabène, Helmi; Pieter, Willy; Franchini, Emerson

    2014-06-01

    Taekwondo has evolved into a modern-day Olympic combat sport. The physical and physiological demands of modern-day taekwondo competition require athletes to be competent in several aspects of fitness. This review critically explores the physical and physiological characteristics of taekwondo athletes and presents implications for training and research. International taekwondo athletes possess low levels of body fat and a somatotype that characterises a blend of moderate musculoskeletal tissue and relative body linearity. While there is some variation in the maximum oxygen uptake of taekwondo athletes, moderate to high levels of cardio-respiratory fitness are necessary to support the metabolic demands of fighting and to facilitate recovery between consecutive matches. Taekwondo athletes demonstrate high peak anaerobic power characteristics of the lower limbs and this attribute appears to be conducive to achieving success in international competition. The ability to generate and sustain power output using both concentric and 'stretch-shortening cycle' muscle actions of the lower limbs may be important to support the technical and tactical actions in combat. Taekwondo competitors also display moderate to high maximum dynamic strength characteristics of the lower and upper extremities, and moderate endurance properties of the trunk and hip flexor musculature. The dynamic nature of the technical and tactical actions in the sport demand high flexibility of the lower limbs. More extensive research is required into the physical and physiological characteristics of taekwondo athletes to extend existing knowledge and to permit specialised conditioning for different populations within the sport.

  13. New concepts in white adipose tissue physiology

    Energy Technology Data Exchange (ETDEWEB)

    Proença, A.R.G. [Universidade Estadual de Campinas, Laboratório de Biotecnologia, Faculdade de Ciências Aplicadas, Limeira, SP, Brasil, Laboratório de Biotecnologia, Faculdade de Ciências Aplicadas, Universidade Estadual de Campinas, Limeira, SP (Brazil); Sertié, R.A.L. [Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Fisiologia e Biofísica, São Paulo, SP, Brasil, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil); Oliveira, A.C. [Universidade Estadual do Ceará, Instituto Superior de Ciências Biomédicas, Fortaleza, CE, Brasil, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE (Brazil); Campaãa, A.B.; Caminhotto, R.O.; Chimin, P.; Lima, F.B. [Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Fisiologia e Biofísica, São Paulo, SP, Brasil, Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil)

    2014-03-03

    Numerous studies address the physiology of adipose tissue (AT). The interest surrounding the physiology of AT is primarily the result of the epidemic outburst of obesity in various contemporary societies. Briefly, the two primary metabolic activities of white AT include lipogenesis and lipolysis. Throughout the last two decades, a new model of AT physiology has emerged. Although AT was considered to be primarily an abundant energy source, it is currently considered to be a prolific producer of biologically active substances, and, consequently, is now recognized as an endocrine organ. In addition to leptin, other biologically active substances secreted by AT, generally classified as cytokines, include adiponectin, interleukin-6, tumor necrosis factor-alpha, resistin, vaspin, visfatin, and many others now collectively referred to as adipokines. The secretion of such biologically active substances by AT indicates its importance as a metabolic regulator. Cell turnover of AT has also recently been investigated in terms of its biological role in adipogenesis. Consequently, the objective of this review is to provide a comprehensive critical review of the current literature concerning the metabolic (lipolysis, lipogenesis) and endocrine actions of AT.

  14. Physiological investigation of dysarthria: recent advances.

    Science.gov (United States)

    Murdoch, Bruce E

    2011-02-01

    Recent years have seen the development and introduction of a range of new physiological instruments for investigating various aspects of articulatory function in persons with dysarthria. Included among these techniques are electromagnetic articulography (EMA), electropalatography (EPG), and pressure-sensing EPG. The aim of this paper is to describe and evaluate these techniques, highlighting their relative advantages, disadvantages, and specific applications in assessing articulation in speakers with dysarthria associated with a variety of neurological disorders. Emphasis will be given to those instruments that enable researchers and clinicians to examine articulatory functions in 3-dimensions, such as 3D-EMA (AG500) and 3D-EPG. In addition the application of pressure-sensing EPG and ultrasonography will be outlined. Each of these physiological techniques will be fully described in terms of their component hardware and underlying principles of operation. The use of each technique in the assessment of dysarthria will be illustrated wherever possible by reference to specific case examples, and especially cases drawn from various neuropathological groups. Research findings reported to date based on each of the above physiological instruments will be reviewed and the research summarized.

  15. Ecological correlates of anuran exercise physiology.

    Science.gov (United States)

    Taigen, Theodore L; Emerson, Sharon B; Pough, F Harvey

    1982-01-01

    Studies of exercise physiology of anuran amphibians have led to the suggestion that there is a dichotomy between species that depend upon movement to escape from predators and species that utilize static defenses. This generalization has been based upon a limited taxonomic survey and it contrasts with morphological, ecological, and behavioral studies that have revealed diverse and complex interrelationships among these features of anuran biology. We tested the hypothesis of a dichotomy of physiological types among anurans by measuring aerobic and anaerobic metabolism during maximum exercise for 17 species representing seven families and a variety of ecological types and locomotor modes. All degrees of dependence upon aerobic and anaerobic power input were found among the 17 species and the variation did not follow phylogenetic divisions. No single, simple prediction of the predominant source of power utilized for activity by the anurans we studied is possible. Predator avoidance behavior was not significantly correlated with the metabolic pattern. Predatory mode (active versus passive searchers) and mode of locomotion (non-jumpers versus jumpers) were correlated with dependence upon aerobic energy production and with each other. Reproductive behavior is probably another associated factor. The diversity of modes of power input among anurans is great and is intimately linked with numerous features of a species' biology. Single-factor explanations of this physiological characteristic are not appropriate.

  16. Status of physiology education in US Doctor of Pharmacy programs.

    Science.gov (United States)

    Islam, Mohammed A; Khan, Seher A; Talukder, Rahmat M

    2016-12-01

    The purpose of the present study was to assess the current status of physiology education in US Doctor of Pharmacy (PharmD) programs. A survey instrument was developed and distributed through SurveyMonkey to American Association of Colleges of Pharmacy (AACP) Biological Sciences section members of 132 PharmD programs. Survey items focused on soliciting qualitative and quantitative information on the delivery of physiology curricular contents and faculty perceptions of physiology education. A total of 114 programs responded to the survey, resulting in a response rate of 86%. Out of 114 schools/colleges, 61 programs (54%) offered standalone physiology courses, and 53 programs (46%) offered physiology integrated with other courses. When integrated, the average contact hours for physiology contents were significantly reduced compared with standalone courses (30 vs. 84 h, P physiology contents. Eighty percent of the responding faculty (n = 204) agree/strongly agree that physiology is underemphasized in PharmD curriculum. Moreover, 67% of the respondents agree/strongly agree that physiology should be taught as a standalone foundational course. A wide variation in the depth and breadth of physiology course offerings in US PharmD programs remains. The reduction of physiology contents is evident when physiology is taught as a component of integrated courses. Given current trends that favor integrated curricula, these data suggest that additional collaboration among basic and clinical science faculty is required to ensure that physiology contents are balanced and not underemphasized in a PharmD curriculum.

  17. Physiological responses and physical performance during football in the heat

    DEFF Research Database (Denmark)

    Mohr, Magni; Nybo, Lars; Grantham, Justin;

    2012-01-01

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

  18. Monitoring the Physiology of Animals in the Wild.

    Science.gov (United States)

    Arehart-Treichel, Joan

    1979-01-01

    The use of radio telemetry as a research tool for studying the physiology of animals under natural conditions is described. Unexpected insights into animals' physiology, particularly the interaction of heart rates and breathing rates, are detailed. (BT)

  19. Biomechanics and physiology in active manual wheelchair propulsion

    NARCIS (Netherlands)

    van der Woude, L H; Veeger, DirkJan (H. E. J.); Dallmeijer, A J; Janssen, T W; Rozendaal, L A

    2001-01-01

    Manual wheelchair propulsion in daily life and sports is increasingly being studied. Initially, an engineering and physiological perspective was taken. More recently a concomitant biomechanics interest is seen. Themes of biomechanical and physiological studies today are performance enhancing aspects

  20. Towards ambulatory mental stress measurement from physiological parameters

    NARCIS (Netherlands)

    Wijsman, J.L.P; Vullers, Ruud; Polito, Salvatore; Agell, Carlos; Penders, Julien; Hermens, Hermanus J.

    Ambulatory mental stress monitoring requires longterm physiological measurements. This paper presents a data collection protocol for ambulatory recording of physiological parameters for stress measurement purposes. We present a wearable sensor system for ambulatory recording of ECG, EMG, respiration

  1. The importance of engineering physiological functionality into microbes

    NARCIS (Netherlands)

    Zhang, Y.; Zhu, Y.; Zhu, Y.; Li, Y.

    2009-01-01

    Good physiological performance of industrial microbes is crucial for successful bioprocesses. Conventional metabolism-oriented engineering strategies often fail to obtain expected phenotypes owing to focusing narrowly on targeted metabolic capabilities while neglecting microbial physiological respon

  2. Fatality of salt stress to plants: Morphological, physiological and ...

    African Journals Online (AJOL)

    Fatality of salt stress to plants: Morphological, physiological and biochemical aspects. ... African Journal of Biotechnology ... Soil salinity affects various physiological and biochemical processes which result in reduced biomass production.

  3. Biomechanics and physiology in active manual wheelchair propulsion

    NARCIS (Netherlands)

    van der Woude, L H; Veeger, DirkJan (H. E. J.); Dallmeijer, A J; Janssen, T W; Rozendaal, L A

    2001-01-01

    Manual wheelchair propulsion in daily life and sports is increasingly being studied. Initially, an engineering and physiological perspective was taken. More recently a concomitant biomechanics interest is seen. Themes of biomechanical and physiological studies today are performance enhancing aspects

  4. Towards ambulatory mental stress measurement from physiological parameters

    NARCIS (Netherlands)

    Wijsman, Jacqueline; Vullers, Ruud; Polito, Salvatore; Agell, Carlos; Penders, Julien; Hermens, Hermie

    2013-01-01

    Ambulatory mental stress monitoring requires longterm physiological measurements. This paper presents a data collection protocol for ambulatory recording of physiological parameters for stress measurement purposes. We present a wearable sensor system for ambulatory recording of ECG, EMG, respiration

  5. Investigating expectation effects using multiple physiological measures

    Directory of Open Access Journals (Sweden)

    Alexander eSiller

    2015-10-01

    Full Text Available The study aimed at experimentally investigating whether the human body can anticipate future events under improved methodological conditions. Previous studies have reported contradictory results for the phenomenon typically called presentiment. If the positive findings are accurate, they call into doubt our views about human perception, and if they are inaccurate, a plausible conventional explanation might be based on the experimental design of the previous studies, in which expectation due to item sequences was misinterpreted as presentiment. To address these points, we opted to collect several physiological variables, to test different randomization types and to manipulate subjective significance individually. For the latter, we combined a mock crime scenario, in which participants had to steal specific items, with a concealed information test (CIT, in which the participants had to conceal their knowledge when interrogated about items they had stolen or not stolen. We measured electrodermal activity, respiration, finger pulse, heart rate, and reaction times. The participants (n=154 were assigned randomly to four different groups. Items presented in the CIT were either drawn with replacement (full or without replacement (pseudo and were either presented category-wise (cat or regardless of categories (nocat. To understand how these item sequences influence expectation and modulate physiological reactions, we compared the groups with respect to effect sizes for stolen vs. not stolen items. Group pseudo_cat yielded the highest effect sizes, and pseudo_nocat yielded the lowest. We could not find any evidence of presentiment but did find evidence of physiological correlates of expectation. Due to the design differing fundamentally from previous studies, these findings do not allow for conclusions on the question whether the expectation bias is being confounded with presentiment.

  6. Investigating expectation effects using multiple physiological measures.

    Science.gov (United States)

    Siller, Alexander; Ambach, Wolfgang; Vaitl, Dieter

    2015-01-01

    The study aimed at experimentally investigating whether the human body can anticipate future events under improved methodological conditions. Previous studies have reported contradictory results for the phenomenon typically called presentiment. If the positive findings are accurate, they call into doubt our views about human perception, and if they are inaccurate, a plausible conventional explanation might be based on the experimental design of the previous studies, in which expectation due to item sequences was misinterpreted as presentiment. To address these points, we opted to collect several physiological variables, to test different randomization types and to manipulate subjective significance individually. For the latter, we combined a mock crime scenario, in which participants had to steal specific items, with a concealed information test (CIT), in which the participants had to conceal their knowledge when interrogated about items they had stolen or not stolen. We measured electrodermal activity, respiration, finger pulse, heart rate (HR), and reaction times. The participants (n = 154) were assigned randomly to four different groups. Items presented in the CIT were either drawn with replacement (full) or without replacement (pseudo) and were either presented category-wise (cat) or regardless of categories (nocat). To understand how these item sequences influence expectation and modulate physiological reactions, we compared the groups with respect to effect sizes for stolen vs. not stolen items. Group pseudo_cat yielded the highest effect sizes, and pseudo_nocat yielded the lowest. We could not find any evidence of presentiment but did find evidence of physiological correlates of expectation. Due to the design differing fundamentally from previous studies, these findings do not allow for conclusions on the question whether the expectation bias is being confounded with presentiment.

  7. Elements of plant physiology in theophrastus' botany.

    Science.gov (United States)

    Pennazio, Sergio

    2014-01-01

    For thousands of years the plants were considered only as a source of food and medicine, and as ornamental objects. Only from the fifth century BC, some philosophers of Ancient Greece realized that the plants were living organisms but, unfortunately, their works have come to us as fragments that we often know from the biological works of Aristotle. This eminent philosopher and man of science, however, did not give us a complete work on the plants, which he often promised to write. From scattered fragments of his conspicuous biological work, it emerges a concept of nutritive soul that, in the presence of heat and moisture, allows plants to grow and reproduce. The task of writing a comprehensive botanical work was delegated to his first pupil, Theophrastus, who left us two treatises over time translated into the various languages up to the current versions (Enquiry into plants, On the causes of plants). The plant life is described and interpreted on the basis of highly accurate observations. The physiological part of his botany is essentially the nutrition: According to Theophrastus, plants get matter and moisture from the soil through root uptake and process the absorbed substances transforming them into food, thanks to the heat. The processing (pepsis, coction) of matter into the food represents an extraordinary physiological intuition because individual organs of a plant appear to perform its specific transformation. Despite that Theophrastus did not do scientific experiments or use special methods other than the sharpness of his observations, he can be considered the forerunner of a plant physiology that would take rebirth only after two millennia.

  8. Evolution and physiology of neural oxygen sensing

    Directory of Open Access Journals (Sweden)

    Kauê Machado Costa

    2014-08-01

    Full Text Available Major evolutionary trends in animal physiology have been heavily influenced by atmospheric O2 levels. Amongst other important factors, the increase in atmospheric O2 which occurred in the Pre-Cambrian and the development of aerobic respiration beckoned the evolution of animal organ systems that were dedicated to the absorption and transportation of O2, e.g., the respiratory and cardiovascular systems of vertebrates. Global variations of O2 levels in post-Cambrian periods have also been correlated with evolutionary changes in animal physiology, especially cardiorespiratory function. Oxygen transportation systems are, in our view, ultimately controlled by the brain related mechanisms, which senses changes in O2 availability and regulates autonomic and respiratory responses that ensure the survival of the organism in the face of hypoxic challenges. In vertebrates, the major sensorial system for oxygen sensing and responding to hypoxia is the peripheral chemoreflex neuronal pathways, which includes the oxygen chemosensitive glomus cells and several brainstem regions involved in the autonomic regulation to the cardiovascular system and respiratory control. In this review we discuss the concept that regulating O2 homeostasis was one of the primordial roles of the nervous system. We also review the physiology of the peripheral chemoreflex, focusing on the integrative repercussions of chemoreflex activation and the evolutionary importance of this system, which is essential for the survival of complex organisms such as vertebrates. The contribution of hypoxia and peripheral chemoreflex for the development of diseases associated to the cardiovascular and respiratory systems is also discussed in an evolutionary context.

  9. Physiologic and Acoustic Effects of Opera Performance.

    Science.gov (United States)

    Kwak, Paul E; Stasney, C Richard; Hathway, Jeremy R; Guffey, Danielle; Minard, Charles G; Ongkasuwan, Julina

    2017-01-01

    Opera performance is physiological and emotional, and singing performers utilize their larynges in often strenuous ways. Historically, the training of a classical voice has been considered the paragon of healthy singing. However, the natural history of a performing larynx has not been studied systematically. There is paucity of scientific studies to guide practice patterns, particularly with regard to the course and extent of post-performance physiologic and acoustic changes. A prospective case series was carried out. Principal singers in the Houston Grand Opera's 2012-2013 repertory were enlisted, for a total of seven singers. Stroboscopy was performed prior to the start of rehearsals, and at the completion of the opera's run. Data points included erythema, edema, masses or lesions, mucosal waveform, supraglottic posture; acoustic measurements were also performed. There were statistically significant differences (P < 0.05) in the mucosal wave on pre- and postperformance stroboscopic examinations. Acoustical measures did not achieve statistical significance, but there was a trend toward increased harmonic-to-noise ratio in postperformance measures, as well as decreased frequency range and reading F0. Measures of intra- and inter-rater reliability indicated varying levels of intra-rater reliability, and generally poor inter-rater reliability. This pilot study describes physiologic and acoustic changes that may occur over the course of a series of rehearsals and performances in the operatic larynx. In so doing, it highlights a need for larger studies with increased frequency of serial examinations to study in a systematized way what may be natural reactive changes that occur during performance. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  10. STUDY OF PHYSIOLOGICAL PROFILE OF INDIAN BOXERS

    Directory of Open Access Journals (Sweden)

    Gulshan Lal Khanna

    2006-07-01

    Full Text Available The present study was conducted to study the morphological, physiological and biochemical characteristics of Indian National boxers as well as to assess the cardiovascular adaptation to graded exercise and actual boxing round. Two different studies were conducted. In the first study [N = 60, (junior boxers below-19 yrs, n = 30, (senior boxers-20-25 yrs, n = 30] different morphological, physiological and biochemical parameters were measured. In the second study (N = 21, Light Weight category- <54 kg, n = 7; Medium weight category <64 kg, n = 7 and Medium heavy weight category <75 kg, n = 7 cardiovascular responses were studied during graded exercise protocol and actual boxing bouts. Results showed a significantly higher (p < 0.05 stature, body mass, LBM, body fat and strength of back and grip in senior boxers compared to juniors. Moreover, the senior boxers possessed mesomorphic body conformation where as the juniors' possessed ectomorphic body conformation. Significantly lower (p < 0.05 aerobic capacity and anaerobic power were noted in junior boxers compared to seniors. Further, significantly higher (p < 0.05 maximal heart rates and recovery heart rates were observed in the seniors as compared to the juniors. Significantly higher maximum heart rates were noted during actual boxing compared to graded exercise. Blood lactate concentration was found to increase with the increase of workload during both graded exercise and actual boxing round. The senior boxers showed a significantly elevated (p < 0.05 levels of hemoblobin, blood urea, uric acid and peak lactate as compared to junior boxers. In the senior boxers significantly lower levels of total cholesterol, triglyceride and LDLC were observed as compared to junior boxers. No significant change has been noted in HDLC between the groups. The age and level of training in boxing has significant effect on Aerobic, anaerobic component. The study of physiological responses during graded exercise

  11. Physiology of man and animals in the Tenth Five-Year Plan: Proceedings of the Thirteenth Congress of the I. P. Pavlov All-Union Physiological Society

    Science.gov (United States)

    Lange, K. A.

    1980-01-01

    Research in the field of animal and human physiology is reviewed. The following topics on problems of physiological science and related fields of knowledge are discussed: neurophysiology and higher nervous activity, physiology of sensory systems, physiology of visceral systems, evolutionary and ecological physiology, physiological cybernetics, computer application in physiology, information support of physiological research, history and theory of development of physiology. Also discussed were: artificial intelligence, physiological problems of reflex therapy, correlation of structure and function of the brain, adaptation and activity, microcirculation, and physiological studies in nerve and mental diseases.

  12. George Eliot's interrogation of physiological future knowledge.

    Science.gov (United States)

    Claggett, Shalyn

    2011-01-01

    This essay tracks George Eliot's sustained interest in the epistemological problems surrounding the Victorian tendency to envision the future through the body's materiality. It argues that her nuanced criticism of phrenology in "The Lifted Veil" (1859) and "A Minor Prophet" (1865) addresses the delimiting psychological and social effects that attend an applied theory of physiological determinism. Returning to this problem in Daniel Deronda (1876), Eliot offers Mordecai's plan to posit Deronda's body as a living emblem as a radical alternative to racial iconography and typological meaning—a move that allowed her to reconcile the body's legibility with a future beyond socially inscribed possibilities.

  13. Statistical physics approaches to understanding physiological fluctuations

    Science.gov (United States)

    Hu, Kun

    This dissertation investigates the influences of the circadian pacemaker on the temporal structures of fluctuations in the human heartbeat and other related physiological signals. The scale-invariant properties of these physiological fluctuations are demonstrated to possess significant circadian rhythms. These findings are relevant in understanding the daily patterns of adverse cardiac events reported by epidemiological studies. Part I of this dissertation introduces the daily pattern in the onset of adverse cardiac events, the circadian pacemaker, and experimental methods of assessing the circadian influences. This part also reviews scale-invariant properties of physiological fluctuations, and scaling analyses that are used to access long-range correlations (an important scale-invariant property). Part II focuses on the effects of trends and nonstationarities---the mean value, standard deviation, and correlation function of signals are not invariant over time. In the case that trends and nonstationarities are unrelated to the underlying mechanism of a signal, simulations and analytic derivations are conducted to explore how to quantify accurately the correlations embedded in the noisy signals that have trends and nonstationarities. Part III investigates dynamics of human motor activity---a physiological function highly correlated with cardiac dynamics. Results demonstrate that apparently random forearm motion possesses previously unrecognized dynamic patterns. These are characterized by similar distribution forms, long-range correlations, and nonlinear Fourier phase interactions across separate individuals and measurements. Part IV reports circadian influences on the dynamic properties of heartbeat fluctuations and activity signals. Correlation properties of heartbeat fluctuations are found to exhibit a significant circadian rhythm that is independent of behavior-related factors including sleep/wake cycles, and random or scheduled events. This circadian rhythm is

  14. [The ethical aspects of physiological experiment].

    Science.gov (United States)

    Al'bertin, S V

    2014-01-01

    A modern classification of invasive procedures developed according to International Bioethical Principles has been presented. The experimental data convincingly demonstrate that using of noninvasive approaches and techniques give a good opportunity to reduce a number of animals recruited in experiment as well as to keep the normal (not distressful) physiological functions of animals. The data presented stress that development of noninvasive techniques is closely related both to scientific and social aspects of our life, allowing the scientists to provide high validity of experimental data obtained as well as to keep themselves as a human beings.

  15. Symbiotic physiology promotes homeostasis in Daisyworld.

    Science.gov (United States)

    Boyle, Richard A; Lenton, Timothy M; Watson, Andrew J

    2011-04-07

    A connection is hypothesized between the physiological consequences of mutualistic symbiosis and life's average long-term impact on certain highly biologically conserved environmental variables. This hypothesis is developed analytically and with a variant of the Daisyworld model. Biological homeostasis is frequently effective due to co-ordination between opposing physiological "rein" functions, which buffer an organism in response to an external (often environmental) perturbation. It is proposed that during evolutionary history the pooling of different species' physiological functions in mutualistic symbioses increased the range of suboptimal environmental conditions that could be buffered against--a mutual tolerance benefit sometimes sufficient to outweigh the cost of cooperation. A related argument is that for a small number of biologically-crucial physical variables (i) the difference between organism interiors and the life-environment interface is relatively low, and (ii) the biologically optimum level of that variable is relatively highly conserved across different species. For such variables, symbiosis tends to cause (at a cost) an increase in the number of environmental buffering functions per unit of selection, which in turn biases the overall impact of the biota on the state of the variable towards the biological optimum. When a costly but more temperature-tolerant and physiologically versatile symbiosis between one black (warming) and one white (cooling) "daisy" is added to the (otherwise unaltered) Daisyworld parable, four new results emerge: (1) The extension of habitability to a wider luminosity range, (2) resistance to the impact of "cheater" white daisies with cold optima, that derive short-term benefit from environmental destabilisation, (3) the capacity to maintain residual, oscillatory regulation in response to forcings that change more rapidly than allele frequencies and (crucially) (4) "succession"-type dynamics in which the tolerant symbiosis

  16. Role of quercetin in vascular physiology.

    Science.gov (United States)

    Chirumbolo, Salvatore

    2012-12-01

    A recent paper in the Canadian Journal of Physiology and Pharmacology has shown that quercetin has a vascular protective effect associated with eNOS up-regulation, blood GSH redox ratio, and reduction of oxidative stress. Recent reports have recommended the consumption of quercetin, as it may contribute to a reduction in the risk of cardiovascular disease. However, the mechanisms by which quercetin exerts its action have not been fully elucidated. The majority of these mechanisms have been identified with models using animals treated with quercetin, and relatively few have been corroborated in human studies, which indicates the need for further investigation.

  17. Bile acids in regulation of intestinal physiology.

    LENUS (Irish Health Repository)

    Keating, Niamh

    2009-10-01

    In addition to their roles in facilitating lipid digestion and absorption, bile acids are recognized as important regulators of intestinal function. Exposure to bile acids can dramatically influence intestinal transport and barrier properties; in recent years, they have also become appreciated as important factors in regulating cell growth and survival. Indeed, few cells reside within the intestinal mucosa that are not altered to some degree by exposure to bile acids. The past decade saw great advances in the knowledge of how bile acids exert their actions at the cellular and molecular levels. In this review, we summarize the current understanding of the role of bile acids in regulation of intestinal physiology.

  18. Rho kinases in cardiovascular physiology and pathophysiology.

    Science.gov (United States)

    Loirand, Gervaise; Guérin, Patrice; Pacaud, Pierre

    2006-02-17

    Rho kinases (ROCKs) are the first and the best-characterized effectors of the small G-protein RhoA. In addition to their effect on actin organization, or through this effect, ROCKs have been found to regulate a wide range of fundamental cell functions such as contraction, motility, proliferation, and apoptosis. Abnormal activation of the RhoA/ROCK pathway has been observed in major cardiovascular disorders such as atherosclerosis, restenosis, hypertension, pulmonary hypertension, and cardiac hypertrophy. This review, based on recent molecular, cellular, and animal studies, focuses on the current understanding of ROCK signaling and its roles in cardiovascular physiology and pathophysiology.

  19. Modeling noisy time series Physiological tremor

    CERN Document Server

    Timmer, J

    1998-01-01

    Empirical time series often contain observational noise. We investigate the effect of this noise on the estimated parameters of models fitted to the data. For data of physiological tremor, i.e. a small amplitude oscillation of the outstretched hand of healthy subjects, we compare the results for a linear model that explicitly includes additional observational noise to one that ignores this noise. We discuss problems and possible solutions for nonlinear deterministic as well as nonlinear stochastic processes. Especially we discuss the state space model applicable for modeling noisy stochastic systems and Bock's algorithm capable for modeling noisy deterministic systems.

  20. Processing of physiological signals in automotive research.

    Science.gov (United States)

    Dambier, Michael; Altmüller, Tobias; Ladstätter, Ulrich

    2006-12-01

    The development of innovative driver assistance systems requires the evaluation of the predisposed hypotheses such as acceptance and driving safety. For this purpose, the conduction of experiments with end-users as subjects is necessary. Analysis and evaluation are based on the recording of numerous sensor values and system variables. Video, gaze and physiological data are recorded for the analysis of gaze distraction and emotional reactions of subjects to system behaviour. In this paper, a modular data streaming and processing architecture is suggested and a concept for this architecture is defined for consistent data evaluation, which integrates off-the-shelf products for data analysis and evaluation.

  1. The Cardiovascular Physiology of Sports and Exercise.

    Science.gov (United States)

    Opondo, Mildred A; Sarma, Satyam; Levine, Benjamin D

    2015-07-01

    Athletes represent the extremes of human performance. Many of their remarkable abilities stem from a cardiovascular system that has adapted to meet the metabolic needs of exercising muscle. A large and compliant heart is a hallmark feature of athletes who engage in highly aerobic events. Despite high fitness levels, athletes may present with symptoms that limit performance. Understanding and dissecting these limitations requires a strong background in sports science and the factors that determine sports capabilities. This article reviews the basic principles of exercise physiology, cardiovascular adaptations unique to the "athlete's heart," and the utility of exercise testing in athletes.

  2. Space Physiology and Operational Space Medicine

    Science.gov (United States)

    Scheuring, Richard A.

    2009-01-01

    The objectives of this slide presentation are to teach a level of familiarity with: the effects of short and long duration space flight on the human body, the major medical concerns regarding future long duration missions, the environmental issues that have potential medical impact on the crew, the role and capabilities of the Space Medicine Flight Surgeon and the environmental impacts experienced by the Apollo crews. The main physiological effects of space flight on the human body reviewed in this presentation are: space motion sickness (SMS), neurovestibular, cardiovascular, musculoskeletal, immune/hematopoietic system and behavioral/psycho-social. Some countermeasures are discussed to these effects.

  3. Conjoined twins: scientific cinema and Pavlovian physiology.

    Science.gov (United States)

    Krementsov, Nikolai

    2015-01-01

    Through the lens of a 1957 documentary film, "Neural and humoral factors in the regulation of bodily functions (research on conjoined twins)," produced by the USSR Academy of Medical Sciences, this essay traces the entwined histories of Soviet physiology, studies of conjoined twins and scientific cinema. It examines the role of Ivan Pavlov and his students, including Leonid Voskresenkii, Dmitrii Fursikov and Petr Anokhin, in the development of "scientific film" as a particular cinematographic genre in Soviet Russia and explores numerous puzzles hidden behind the film's striking visuals. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  4. A virtual laboratory system for physiology teaching

    Directory of Open Access Journals (Sweden)

    KArl Bohme

    1995-12-01

    Full Text Available There exist a number of areas in the teaching of physiology which potentially lend themselves to a Computer-Based Learning approach. One such area which has been explored at Manchester Metropolitan University (MMU and elsewhere (Dewhurst, 1993; Kwan, 1993 is the use of multimedia tools to simulate aspects of experiments traditionally performed on animals. The use of real animal specimens (for example, frogs or rats for dissection and experimentation is both costly and contrary to the ethics of some students.

  5. Intracellular pH in sperm physiology.

    Science.gov (United States)

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction.

  6. Calcium signaling in physiology and pathophysiology

    Institute of Scientific and Technical Information of China (English)

    He-ping CHENG; Sheng WEI; Li-ping WEI; Alexei VERKHRATSKY

    2006-01-01

    Calcium ions are the most ubiquitous and pluripotent cellular signaling molecules that control a wide variety of cellular processes.The calcium signaling system is represented by a relatively limited number of highly conserved transporters and channels,which execute Ca2+ movements across biological membranes and by many thousands of Ca2+-sensitive effectors.Molecular cascades,responsible for the generation of calcium signals,are tightly controlled by Ca2+ ions themselves and by genetic factors,which tune the expression of different Ca2+-handling molecules according to adaptational requirements.Ca2+ ions determine normal physiological reactions and the development of many pathological processes.

  7. Basic Shock Physiology and Critical Care.

    Science.gov (United States)

    Roberts, Brian K

    2016-05-01

    Veterinarians practicing emergency medicine and/or working with exotic animals must be well versed in the pathophysiology of shock because many exotic pets present with an acute crisis or an acute manifestation of a chronic process causing poor organ perfusion. This article discusses the pathophysiology of shock and the systemic inflammatory response syndrome, which may lead to organ dysfunction, organ failure, sepsis, and death. The physiology of perfusion, perfusion measurements, categories of shock, and altered function of the immune system, gastrointestinal barrier, and coagulation system are discussed. Veterinarians providing emergency care to patients with shock must also be aware of comorbidities. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Integrative physiology of orexins and orexin receptors.

    Science.gov (United States)

    Mieda, Michihiro; Sakurai, Takeshi

    2009-08-01

    Recent studies have established that the orexin system is a critical regulator of sleep/wake states. Deficiency of orexin signaling results in the sleep disorder narcolepsy-cataplexy in humans, dogs, and rodents. These findings have brought about the possibility of novel therapies for sleep disorders including narcolepsy-cataplexy. Furthermore, accumulating evidence has indicated that the orexin system regulates sleep and wakefulness through interactions with neuronal systems that regulate emotion, reward, and energy homeostasis. This review presents and discusses the current understanding of the integrative physiology of the orexin system.

  9. Measuring Dynamic Kidney Function in an Undergraduate Physiology Laboratory

    Science.gov (United States)

    Medler, Scott; Harrington, Frederick

    2013-01-01

    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…

  10. Transferring a Classic Dog Laboratory To Videodisc: Cardiovascular Physiology

    Science.gov (United States)

    Terpstra, J.K.; Harris, T.M.

    1989-01-01

    This demonstration presents the development process and intended uses of the Classic Laboratory Experiments in Basic Health Sciences: Cardiovascular Physiology videodisc containing over thirty experiments. This interactive videodisc is designed to teach the physiological effects of procedures and drugs on the cardiovascular system. The Cardiovascular Physiology program is the first in a series of classic dog laboratory videodiscs to be developed.

  11. Principles and standards for reporting animal experiments in The Journal of Physiology and Experimental Physiology.

    Science.gov (United States)

    Grundy, David

    2015-07-01

    The Journal of Physiology and Experimental Physiology have always used UK legislation as the basis of their policy on ethical standards in experiments on non-human animals. However, for international journals with authors, editors and referees from outside the UK the policy can lack transparency and is sometimes cumbersome, requiring the intervention of a Senior Ethics Reviewer or advice from external experts familiar with UK legislation. The journals have therefore decided to set out detailed guidelines for how authors should report experimental procedures that involve animals. As well as helping authors, this new clarity will facilitate the review process and decision making where there are questions regarding animal ethics.

  12. Physiological regulation of NEFA availability: lipolysis pathway.

    Science.gov (United States)

    Stich, V; Berlan, M

    2004-05-01

    Plasma NEFA are an important energy substrate and, furthermore, play a key role in the induction of insulin resistance in the body. The availability of NEFA is determined predominantly by their mobilization from adipose tissue triacylglycerol stores by the process of lipolysis. Adipose tissue lipolysis in man is regulated by a number of hormonal and paracrine and/or autocrine signals. The main hormonal signals may be represented by catecholamines, insulin, growth hormone, natriuretic peptides and some adipocytokines. The absolute levels and relative importance and contribution of these signals vary in different physiological situations, with diet and physical exercise being the main physiological variables that affect the hormonal signalling. Thus, modulations in hormonal signals induce an increase in NEFA mobilization in the post-absorptive state and during an acute bout of exercise, and suppress NEFA mobilization in the postprandial state. In addition, hormonal regulation is modified by long-term interventions in energy balance, such as dietary restriction and/or physical training, and is disturbed in some pathological states, such as obesity or diabetes. The question that remains is whether disturbances in lipolysis regulation in obese and diabetic subjects may be 'corrected' by the long-term interventions in diet and physical activity.

  13. Gut Melatonin in Vertebrates: Chronobiology and Physiology.

    Science.gov (United States)

    Mukherjee, Sourav; Maitra, Saumen Kumar

    2015-01-01

    Melatonin, following discovery in the bovine pineal gland, has been detected in several extra-pineal sources including gastrointestinal tract or gut. Arylalkylamine N-acetyltransferase (AANAT) is the key regulator of its biosynthesis. Melatonin in pineal is rhythmically produced with a nocturnal peak in synchronization with environmental light-dark cycle. A recent study on carp reported first that melatonin levels and intensity of a ~23 kDa AANAT protein in each gut segment also exhibit significant daily variations but, unlike pineal, show a peak at midday in all seasons. Extensive experimental studies ruled out direct role of light-dark conditions in determining temporal pattern of gut melatoninergic system in carp, and opened up possible role of environmental non-photic cue(s) as its synchronizer. Based on mammalian findings, physiological significance of gut-derived melatonin also appears unique because its actions at local levels sharing paracrine and/or autocrine functions have been emphasized. The purpose of this mini review is to summarize the existing data on the chronobiology and physiology of gut melatonin and to emphasize their relation with the same hormone derived in the pineal in vertebrates including fish.

  14. The conservation physiology of seed dispersal.

    Science.gov (United States)

    Ruxton, Graeme D; Schaefer, H Martin

    2012-06-19

    At a time when plant species are experiencing increasing challenges from climate change, land-use change, harvesting and invasive species, dispersal has become a very important aspect of plant conservation. Seed dispersal by animals is particularly important because some animals disperse seeds to suitable sites in a directed fashion. Our review has two aims: (i) to highlight the various ways plant dispersal by animals can be affected by current anthropogenic change and (ii) to show the important role of plant and (particularly) animal physiology in shaping seed-dispersal interactions. We argue that large-bodied seed dispersers may be particularly important for plant conservation because seed dispersal of large-seeded plants is often more specialized and because large-bodied animals are targeted by human exploitation and have smaller population sizes. We further argue that more specialized seed-dispersal systems on island ecosystems might be particularly at risk from climate change both owing to small population sizes involved but also owing to the likely thermal specialization, particularly on tropical islands. More generally, the inherent vulnerability of seed-dispersal mutualisms to disruption driven by environmental change (as well as their ubiquity) demands that we continue to improve our understanding of their conservation physiology.

  15. Is physiological glucocorticoid replacement important in children?

    Science.gov (United States)

    Porter, John; Blair, Joanne; Ross, Richard J

    2017-01-01

    Cortisol has a distinct circadian rhythm with low concentrations at night, rising in the early hours of the morning, peaking on waking and declining over the day to low concentrations in the evening. Loss of this circadian rhythm, as seen in jetlag and shift work, is associated with fatigue in the short term and diabetes and obesity in the medium to long term. Patients with adrenal insufficiency on current glucocorticoid replacement with hydrocortisone have unphysiological cortisol concentrations being low on waking and high after each dose of hydrocortisone. Patients with adrenal insufficiency complain of fatigue, a poor quality of life and there is evidence of poor health outcomes including obesity potentially related to glucocorticoid replacement. New technologies are being developed that deliver more physiological glucocorticoid replacement including hydrocortisone by subcutaneous pump, Plenadren, a once-daily modified-release hydrocortisone and Chronocort, a delayed and sustained absorption hydrocortisone formulation that replicates the overnight profile of cortisol. In this review, we summarise the evidence regarding physiological glucocorticoid replacement with a focus on relevance to paediatrics. PMID:27582458

  16. Misophonia: physiological investigations and case descriptions

    Directory of Open Access Journals (Sweden)

    Miren eEdelstein

    2013-06-01

    Full Text Available Misophonia is a relatively unexplored chronic condition in which a person experiences autonomic arousal (analogous to an involuntary fight-or-flight response to certain innocuous or repetitive sounds such as chewing, pen clicking and lip smacking. Misophonics report anxiety, panic and rage when exposed to trigger sounds, compromising their ability to complete everyday tasks and engage in healthy and normal social interactions. Across two experiments, we measured behavioral and physiological characteristics of the condition. Interviews (Experiment 1 with misophonics showed that the most problematic sounds are generally related to other people's behavior (pen clicking, chewing sounds. Misophonics are however not bothered when they produce these trigger sounds themselves, and some report mimicry as a coping strategy. Next, (Experiment 2 we tested the hypothesis that misophonics’ subjective experiences evoke an anomalous physiological response to certain auditory stimuli. Misophonic individuals showed heightened ratings and skin conductance responses to auditory, but not visual stimuli, relative to a group of typically developed controls, supporting this general viewpoint and indicating that misophonia is a disorder that produces distinct autonomic effects not seen in typically developed individuals.

  17. Physiological and phytosanitary potential of rocket seeds

    Directory of Open Access Journals (Sweden)

    Jucilayne Fernandes Vieira

    2015-02-01

    Full Text Available The objective of this study was to evaluate the physiological and sanitary quality of seeds of rocket; the research was done at the Laboratory of Seed Analysis and greenhouse of the Department of Plant Science, Federal University of Pelotas (UFPel. Four lots of the cultivar "Antonella'' were tested for following features: initial and final moisture content, germination rate, first count of germination, accelerated aging with saline solution, dry matter contents, seedling shoot and root length, emergence speed index, emergence of seedlings in substrate, electrical conductivity and sanitary condition. A completely randomized design with four replications was used for all tests done and means were compared by Tukey test (P≤0.05. For all tests performed it was concluded that despite changes in the ranking of the best lots, there was agreement regarding the indication of the inferiority of the lot 3 in all tests and it was also observed that the incidence of fungi associated with seeds of rocket interfere with the physiological quality of the lots.

  18. Physiological and psychological assessment of sound

    Science.gov (United States)

    Yanagihashi, R.; Ohira, Masayoshi; Kimura, Teiji; Fujiwara, Takayuki

    The psycho-physiological effects of several sound stimulations were investigated to evaluate the relationship between a psychological parameter, such as subjective perception, and a physiological parameter, such as the heart rate variability (HRV). Eight female students aged 21-22 years old were tested. Electrocardiogram (ECG) and the movement of the chest-wall for estimating respiratory rate were recorded during three different sound stimulations; (1) music provided by a synthesizer (condition A); (2) birds twitters (condition B); and (3) mechanical sounds (condition C). The percentage power of the low-frequency (LF; 0.05<=0.15 Hz) and high-frequency (HF; 0.15<=0.40 Hz) components in the HRV (LF%, HF%) were assessed by a frequency analysis of time-series data for 5 min obtained from R-R intervals in the ECG. Quantitative assessment of subjective perception was also described by a visual analog scale (VAS). The HF% and VAS value for comfort in C were significantly lower than in either A and/or B. The respiratory rate and VAS value for awakening in C were significantly higher than in A and/or B. There was a significant correlation between the HF% and the value of the VAS, and between the respiratory rate and the value of the VAS. These results indicate that mechanical sounds similar to C inhibit the para-sympathetic nervous system and promote a feeling that is unpleasant but alert, also suggesting that the HRV reflects subjective perception.

  19. Biotin: biochemical, physiological and clinical aspects.

    Science.gov (United States)

    Said, Hamid M

    2012-01-01

    Significant progress has been made in our understanding of the biochemical, physiological and nutritional aspects of the water-soluble vitamin biotin (vitamin H). It is well know now that biotin plays important roles in a variety of critical metabolic reactions in the cell, and thus, is essential for normal human health, growth and development. This is underscored by the serious clinical abnormalities that occur in conditions of biotin deficiency, which include, among other things, growth retardation, neurological disorders, and dermatological abnormalities (reviewed in 1). Studies in animals have also shown that biotin deficiency during pregnancy leads to embryonic growth retardation, congenital malformation and death (Watanabe 1983; Cooper and Brown 1958; Mock et al. 2003; Zempleni and Mock 2000). The aim of this chapter is to provide coverage of current knowledge of the biochemical, physiological, and clinical aspects of biotin nutrition. Many sections of this chapter have been the subject of excellent recent reviews by others (Wolf 2001; McMahon 2002; Mock 2004; Rodriguez-Melendez and Zempleni 2003; Said 2004; Said et al. 2000; Said and Seetheram 2006), and thus, for more information the reader is advised to consider these additional sources.

  20. Auxin physiology of the tomato mutant diageotropica

    Science.gov (United States)

    Daniel, S. G.; Rayle, D. L.; Cleland, R. E.

    1989-01-01

    The tomato (Lycopersicon esculentum, Mill.) mutant diageotropica (dgt) exhibits biochemical, physiological, and morphological abnormalities that suggest the mutation may have affected a primary site of auxin perception or action. We have compared two aspects of the auxin physiology of dgt and wild-type (VFN8) seedlings: auxin transport and cellular growth parameters. The rates of basipetal indole-3-acetic acid (IAA) polar transport are identical in hypocotyl sections of the two genotypes, but dgt sections have a slightly greater capacity for IAA transport. 2,3,5-Triiodobenzoic acid and ethylene reduce transport in both mutant and wild-type sections. The kinetics of auxin uptake into VFN8 and dgt sections are nearly identical. These results make it unlikely that an altered IAA efflux carrier or IAA uptake symport are responsible for the pleiotropic effects resulting from the dgt mutation. The lack of auxin-induced cell elongation in dgt plants is not due to insufficient turgor, as the osmotic potential of dgt cell sap is less (more negative) than that of VFN8. An auxin-induced increase in wall extensibility, as measured by the Instron technique, only occurs in the VFN8 plants. These data suggest dgt hypocotyls suffer a defect in the sequence of events culminating in auxin-induced cell wall loosening.

  1. A Fibre Optic Sensor Of Physiological Parameters

    Science.gov (United States)

    Legendre, J. P.; Forester, G. V.

    1986-11-01

    This paper presents an ultraminiature fibre optic probe capable of physiological monitoring in situ. The system has been described previously where a fibre optic reflectometer was configured as a temperature sensor and as a refractometer. For the present experiments a bare fibre tip was used as sensing element. We show that we have been able to monitor cyclic physiological parameters such as heart and respiratory rates in various animal preparations. The probe has been used to obtain signals from the oesophagus, the lower gastro-intestinal tract, the abdominal cavity and from blood vessels (arteries and veins). The probe has also measured phasic activity coincident with mechanical activity of isolated heart muscle. The small physical size of the sensor (125 µm diameter), its flexibility and the fact that it is biologically inert are all very important characteristics for medical and biological considerations. Most recently, the probe has been used to monitor cardiac and respiratory rates while obtaining NMR spectra assessing metabolic activity. This was possible only because the probe is magnetically transparent.

  2. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

    Women's soccer is in its infancy as a sport and research into its physiological demands and the physical characteristics of players is somewhat limited. There is now an increasing demand for scientific investigation of the female game and of the players, match analysis and role variations requiring particular attention. Current research suggests that the demands of the game for women are similar to those placed on male players. Women are reported to cover a similar distance (mean 8471m) to their male counterparts during a game and much the same proportions of the game appear to be devoted to exercise of varying intensities. Furthermore, female and male players appear to tax the aerobic and anaerobic energy systems to a similar level. The physical and physiological characteristics of female soccer players are comparable with those of other female games players and are more favourable than average for the population. Mean body fat percentages of between 19.7 and 22.0% and VO2max values of between 47.1 and 57.6 ml/kg/min have been reported for elite female players, while faster than average sprint times are also characteristic of them.

  3. Physiological characteristics of international female soccer players.

    Science.gov (United States)

    Manson, Sarah A; Brughelli, Matt; Harris, Nigel K

    2014-02-01

    The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p velocity (ES = 0.78-2.45, p velocity (ES = 0.87, p players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players.

  4. Undergraduate students' misconceptions about respiratory physiology.

    Science.gov (United States)

    Michael, J A; Richardson, D; Rovick, A; Modell, H; Bruce, D; Horwitz, B; Hudson, M; Silverthorn, D; Whitescarver, S; Williams, S

    1999-12-01

    Approximately 700 undergraduates studying physiology at community colleges, a liberal arts college, and universities were surveyed to determine the prevalence of our misconceptions about respiratory phenomena. A misconception about the changes in breathing frequency and tidal volume (physiological variables whose changes can be directly sensed) that result in increased minute ventilation was found to be present in this population with comparable prevalence (approximately 60%) to that seen in a previous study. Three other misconceptions involving phenomena that cannot be experienced directly and therefore were most likely learned in some educational setting were found to be of varying prevalence. Nearly 90% of the students exhibited a misconception about the relationship between arterial oxygen partial pressure and hemoglobin saturation. Sixty-six percent of the students believed that increasing alveolar oxygen partial pressure leads to a decrease in alveolar carbon dioxide partial pressure. Nearly 33% of the population misunderstood the relationship between metabolism and ventilation. The possible origins of these respiratory misconceptions are discussed and suggestions for how to prevent and/or remediate them are proposed.

  5. Structure and Physiological Actions of Ghrelin

    Directory of Open Access Journals (Sweden)

    Christine Delporte

    2013-01-01

    Full Text Available Ghrelin is a gastric peptide hormone, discovered as being the endogenous ligand of growth hormone secretagogue receptor. Ghrelin is a 28 amino acid peptide presenting a unique n-octanoylation modification on its serine in position 3, catalyzed by ghrelin O-acyl transferase. Ghrelin is mainly produced by a subset of stomach cells and also by the hypothalamus, the pituitary, and other tissues. Transcriptional, translational, and posttranslational processes generate ghrelin and ghrelin-related peptides. Homo- and heterodimers of growth hormone secretagogue receptor, and as yet unidentified receptors, are assumed to mediate the biological effects of acyl ghrelin and desacyl ghrelin, respectively. Ghrelin exerts wide physiological actions throughout the body, including growth hormone secretion, appetite and food intake, gastric secretion and gastrointestinal motility, glucose homeostasis, cardiovascular functions, anti-inflammatory functions, reproductive functions, and bone formation. This review focuses on presenting the current understanding of ghrelin and growth hormone secretagogue receptor biology, as well as the main physiological effects of ghrelin.

  6. Metabolic methanol: molecular pathways and physiological roles.

    Science.gov (United States)

    Dorokhov, Yuri L; Shindyapina, Anastasia V; Sheshukova, Ekaterina V; Komarova, Tatiana V

    2015-04-01

    Methanol has been historically considered an exogenous product that leads only to pathological changes in the human body when consumed. However, in normal, healthy individuals, methanol and its short-lived oxidized product, formaldehyde, are naturally occurring compounds whose functions and origins have received limited attention. There are several sources of human physiological methanol. Fruits, vegetables, and alcoholic beverages are likely the main sources of exogenous methanol in the healthy human body. Metabolic methanol may occur as a result of fermentation by gut bacteria and metabolic processes involving S-adenosyl methionine. Regardless of its source, low levels of methanol in the body are maintained by physiological and metabolic clearance mechanisms. Although human blood contains small amounts of methanol and formaldehyde, the content of these molecules increases sharply after receiving even methanol-free ethanol, indicating an endogenous source of the metabolic methanol present at low levels in the blood regulated by a cluster of genes. Recent studies of the pathogenesis of neurological disorders indicate metabolic formaldehyde as a putative causative agent. The detection of increased formaldehyde content in the blood of both neurological patients and the elderly indicates the important role of genetic and biochemical mechanisms of maintaining low levels of methanol and formaldehyde.

  7. Physiological functions of plant cell coverings.

    Science.gov (United States)

    Hoson, Takayuki

    2002-08-01

    The cell coverings of plants have two important functions in plant life. Plant cell coverings are deeply involved in the regulation of the life cycle of plants: each stage of the life cycle, such as germination, vegetative growth, reproductive growth, and senescence, is strongly influenced by the nature of the cell coverings. Also, the apoplast, which consists of the cell coverings, is the field where plant cells first encounter the outer environment, and so becomes the major site of plant responses to the environment. In the regulation of each stage of the life cycle and the response to each environmental signal, some specific constituents of the cell coverings, such as xyloglucans in dicotyledons and 1,3,1,4-beta-glucans in Gramineae, act as the key component. The physiological functions of plant cell coverings are sustained by the metabolic turnover of these components. The components of the cell coverings are supplied from the symplast, but then they are modified or degraded in the apoplast. Thus, the metabolism of the cell coverings is regulated through the cross-talk between the symplast and the apoplast. The understanding of physiological functions of plant cell coverings will be greatly advanced by the use of genomic approaches. At the same time, we need to introduce nanobiological techniques for clarifying the minute changes in the cell coverings that occur in a small part within each cell.

  8. Ecstasy from a physiological point of view

    Directory of Open Access Journals (Sweden)

    Kaj Björkqvist

    1982-01-01

    Full Text Available The biological study of man is one of today's most rapidly advancing sciences. There is no reason for not utilizing these methodologies of research and the knowledge already gained when studying ecstasy and other similar religious phenomena. Drugs have been used in all parts of the world as an ecstasy technique. Since mental states and physiological correlates always accompany each other, it is obvious that the human mind can be affected by external means, for instance by drugs. But the opposite is also true; mental changes affect the body, as they do in the case of psychosomatic diseases. Ecstasy is often described as an extremely joyful experience; this pleasure must necessarily also have a physiological basis. It is of course too early to say anything for certain, but the discovery of pleasure centres in the brain might offer an explanation. It is not far-fetched to suggest that when a person experiences euphoric ecstasy, it might, in some way or other, be connected with a cerebral pleasure center. Can it be, for example, that religious ecstasy is attained only by some mechanism triggering off changes in the balance of the transmitter substances? Or is it reached only via a change in the hormonal balance, or only by a slowing down of the brain waves, or is a pleasure centre activated? When a person is using an ecstasy technique, he usually does so within a religious tradition. When he reaches an experience, a traditional interpretation of it already exists.

  9. Pregnancy: Comparison among Physiological and Pathological States

    Directory of Open Access Journals (Sweden)

    Angela Lucariello

    2014-01-01

    Full Text Available The WFS1 gene, encoding a transmembrane glycoprotein of the endoplasmic reticulum called wolframin, is mutated in Wolfram syndrome, an autosomal recessive disorder defined by the association of diabetes mellitus, optic atrophy, and further organ abnormalities. Disruption of the WFS1 gene in mice causes progressive β-cell loss in the pancreas and impaired stimulus-secretion coupling in insulin secretion. However, little is known about the physiological functions of this protein. We investigated the immunohistochemical expression of wolframin in human placenta throughout pregnancy in normal women and diabetic pregnant women. In normal placenta, there was a modulation of wolframin throughout pregnancy with a strong level of expression during the first trimester and a moderate level in the third trimester of gestation. In diabetic women, wolframin expression was strongly reduced in the third trimester of gestation. The pattern of expression of wolframin in normal placenta suggests that this protein may be required to sustain normal rates of cytotrophoblast cell proliferation during the first trimester of gestation. The decrease in wolframin expression in diabetic placenta suggests that this protein may participate in maintaining the physiologic glucose homeostasis in this organ.

  10. Integration of Life-Stage Physiologically Based ...

    Science.gov (United States)

    A Life-stage Physiologically-Based Pharmacokinetic (PBPK) model was developed to include descriptions of several life-stage events such as pregnancy, fetal development, the neonate and child growth. The overall modeling strategy was used for in vitro to in vivo (IVIVE) extrapolation to help contextualize activity in ToxCast assays that were mapped to an adverse outcome pathway (AOP) for embryonic vascular disruption. Using life-stage PBPK models, we estimated maternal exposures that would yield fetal blood levels equivalent to in vitro activity from ToxCast assays with critical vascular signaling targets. The resulting in vivo dose estimates were then compared to life-time exposures using literature data or exposure models (SHEDS-LITE) to derive AOP-based Margins of Exposure (ME). This computational framework was applied to a list of five chemicals with varying activity against the putative Vascular Disruption AOP. The idea of linking biological information related to toxicity (using AOPs), high throughput in vitro data (ToxCast), and age-varying physiological and biochemical information to estimate AOP-based MEs is novel and can be used to help regulators in realistically assessing chemicals based on toxicity, dosimetry, and real-life exposures. Developing fetuses and infants are especially sensitive to toxicity caused by exposure to xenobiotics. The time and dose to which a developing target tissue is exposed during pregnancy or via lactation after birth are c

  11. The conservation physiology of seed dispersal

    Science.gov (United States)

    Ruxton, Graeme D.; Schaefer, H. Martin

    2012-01-01

    At a time when plant species are experiencing increasing challenges from climate change, land-use change, harvesting and invasive species, dispersal has become a very important aspect of plant conservation. Seed dispersal by animals is particularly important because some animals disperse seeds to suitable sites in a directed fashion. Our review has two aims: (i) to highlight the various ways plant dispersal by animals can be affected by current anthropogenic change and (ii) to show the important role of plant and (particularly) animal physiology in shaping seed–dispersal interactions. We argue that large-bodied seed dispersers may be particularly important for plant conservation because seed dispersal of large-seeded plants is often more specialized and because large-bodied animals are targeted by human exploitation and have smaller population sizes. We further argue that more specialized seed-dispersal systems on island ecosystems might be particularly at risk from climate change both owing to small population sizes involved but also owing to the likely thermal specialization, particularly on tropical islands. More generally, the inherent vulnerability of seed-dispersal mutualisms to disruption driven by environmental change (as well as their ubiquity) demands that we continue to improve our understanding of their conservation physiology. PMID:22566677

  12. Gut Melatonin in Vertebrates: Chronobiology and Physiology

    Directory of Open Access Journals (Sweden)

    Dr. Saumen Kumar Maitra

    2015-07-01

    Full Text Available Melatonin, following discovery in the bovine pineal gland, has been detected in several extra-pineal sources including gastrointestinal tract or gut. Arylalkylamine N-acetyltransferase (AANAT is the key regulator of its biosynthesis. Melatonin in pineal is rhythmically produced with a nocturnal peak in synchronization with environmental light-dark cycle. A recent study on carp reported first that melatonin levels and intensity of a ~23kDa AANAT protein in each gut segment also exhibit significant daily variations but, unlike pineal, show a peak at midday in all seasons. Extensive experimental studies ruled out direct role of light-dark conditions in determining temporal pattern of gut melatoninergic system in carp, and opened up possible role of environmental non-photic cue(s as its synchronizer. Based on mammalian findings, physiological significance of gut derived melatonin also appears unique because its actions at local levels sharing paracrine and/or autocrine functions have been emphasized. The purpose of this mini-review is to summarize existing data on the chronobiology and physiology of gut melatonin and to emphasize their relation with the same hormone derived in the pineal in vertebrates including fish.

  13. Amateur boxing: physical and physiological attributes.

    Science.gov (United States)

    Chaabène, Helmi; Tabben, Montassar; Mkaouer, Bessem; Franchini, Emerson; Negra, Yassine; Hammami, Mehrez; Amara, Samiha; Chaabène, Raja Bouguezzi; Hachana, Younés

    2015-03-01

    Boxing is one of the oldest combat sports. The aim of the current review is to critically analyze the amateur boxer's physical and physiological characteristics and to provide practical recommendations for training as well as new areas of scientific research. High-level male and female boxers show a propensity for low body fat levels. Although studies on boxer somatotypes are limited, the available information shows that elite-level male boxers are characterized by a higher proportion of mesomorphy with a well-developed muscle mass and a low body fat level. To help support the overall metabolic demands of a boxing match and to accelerate the recovery process between rounds, athletes of both sexes require a high level of cardiorespiratory fitness. International boxers show a high peak and mean anaerobic power output. Muscle strength in both the upper and lower limbs is paramount for a fighter's victory and is one of the keys to success in boxing. As boxing punches are brief actions and very dynamic, high-level boxing performance requires well-developed muscle power in both the upper and lower limbs. Albeit limited, the available studies reveal that isometric strength is linked to high-level boxing performance. Future investigations into the physical and physiological attributes of boxers are required to enrich the current data set and to help create a suitable training program.

  14. Physiological Effects of Touching Coated Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

    Full Text Available This study examined the physiological effects of touching wood with various coating with the palm of the hand on brain activity and autonomic nervous activity. Participants were 18 female university students (mean age, 21.7 ± 1.6 years. As an indicator of brain activity, oxyhemoglobin concentrations were measured in the left and right prefrontal cortices using near-infrared time-resolved spectroscopy. Heart rate variability (HRV and heart rate were used as indicators of autonomic nervous activity. The high-frequency (HF component of HRV, which reflects parasympathetic nervous activity, and the low-frequency (LF/HF ratio, which reflects sympathetic nervous activity, were measured. Plates of uncoated, oil-finished, vitreous-finished, urethane-finished, and mirror-finished white oak wood were used as tactile stimuli. After sitting at rest with their eyes closed for 60 s, participants touched the stimuli with their palm for 90 s each. The results indicated that tactile stimulation with uncoated wood calmed prefrontal cortex activity (vs. urethane finish and mirror finish, increased parasympathetic nervous activity (vs. vitreous finish, urethane finish, and mirror finish, and decreased heart rate (vs. mirror finish, demonstrating a physiological relaxation effect. Further, tactile stimulation with oil- and vitreous-finished wood calmed left prefrontal cortex activity and decreased heart rate relative to mirror-finished wood.

  15. International Union of Physiological Sciences Physiology Teaching Workshop, March 31-April 1, 2012, Arabian Gulf University, Kingdom of Bahrain

    Science.gov (United States)

    Subhan, M. M. F.

    2013-01-01

    Since 2009, the Department of Physiology had planned an International Union of Physiological Sciences Physiology Teaching Workshop at Arabian Gulf University. The date was set for March 5-6, 2011; however, due to civil unrest, the workshop was postponed to March 31-April 1, 2012. The workshop was a success, bringing together 92 speakers and…

  16. Integrated imaging of cardiac anatomy, physiology, and viability.

    Science.gov (United States)

    Arrighi, James A

    2009-03-01

    Technologic developments in imaging will have a significant impact on cardiac imaging over the next decade. These advances will permit more detailed assessment of cardiac anatomy, complex assessment of cardiac physiology, and integration of anatomic and physiologic data. The distinction between anatomic and physiologic imaging is important. For assessing patients with known or suspected coronary artery disease, physiologic and anatomic imaging data are complementary. The strength of anatomic imaging rests in its ability to detect the presence of disease, whereas physiologic imaging techniques assess the impact of disease, such as whether a coronary atherosclerotic lesion limits myocardial blood flow. Research indicates that physiologic data are more prognostically important than anatomic data, but both may be important in patient management decisions. Integrated cardiac imaging is an evolving field, with many potential indications. These include assessment of coronary stenosis, myocardial viability, anatomic and physiologic characterization of atherosclerotic plaque, and advanced molecular imaging.

  17. Active learning of respiratory physiology improves performance on respiratory physiology examinations.

    Science.gov (United States)

    Rao, S P; DiCarlo, S E

    2001-12-01

    Active involvement in the learning process has been suggested to enhance creative thinking, judgement, interpretation, and problem-solving skills. Therefore, educators are encouraged to create an active-learning environment by incorporating active-learning strategies into the class. However, there is very little documentation of the effectiveness of active-learning strategies. Furthermore, faculty are often reluctant to incorporate new strategies without documentation of the effectiveness of these strategies. To address this concern, we compared the performance of two individual classes on an identical respiratory physiology examination. One class was taught respiratory physiology using active-learning strategies. The other class was taught respiratory physiology using the traditional lecture format. The results document that students who learned using active-learning strategies did significantly better (P < 0.05) on the respiratory physiology examination than students who learned by the traditional lecture format (61 +/- 2.2 vs. 86 +/- 1.0). Thus, by actively involving students in the learning process, academic performance is enhanced.

  18. Exercise Physiology and the Academy: Contributions to Physiological Concepts and Biological Systems during the Commemorative Years

    Science.gov (United States)

    Tipton, Charles M.

    2006-01-01

    To determine the contributions made by Academy Fellows during the past 75 years to concepts within the body of knowledge associated with exercise physiology, a literature search was undertaken. Of the charter Fellows, Hetherington and eight others (34%) were identified. Schneider in 1933 was the first of 18 Fellows who became authors, co-authors,…

  19. KCNK5 in Physiology and Pathophysiology

    DEFF Research Database (Denmark)

    Kirkegaard, Signe Skyum

    to study the effect on physiology and channel expression patterns (Paper II). We found that 48 h of hypotonic stimulation reduced the maximum current through the channel and likewise decreased the cells ability to perform RVD. This impairment was found to be likely due to lowered KCNK5 protein expression...... proposed to play a role in T cell activation and in multiple sclerosis. When a cell experiences swelling do to osmotic changes in the extracellular or intracellular environment most mammalian cells will regulate their volume back towards the starting point – an important feature in keeping cellular...... to be an important player in RVD in different cell types and tissue e.g. in Ehrlich cells. It has been speculated that tyrosine phosphorylation is necessary for the swelling-activation of the channel and in “Paper I” we show how acute hypotonic swelling induces a time-dependent tyrosine phosphorylation upon...

  20. Archaea: Evolution, Physiology, and Molecular Biology

    DEFF Research Database (Denmark)

    Introduced by Crafoord Prize winner Carl Woese, this volume combines reviews of the major developments in archaeal research over the past 10-15 years with more specialized articles dealing with important recent breakthroughs. Drawing on major themes presented at the June 2005 meeting held in Muni...... and technological context, and include accounts of cutting-edge research developments. The book spans archaeal evolution, physiology, and molecular and cellular biology and will be an essential reference for both graduate students and researchers....... to honor the archaea pioneers Wolfram Zillig and Karl O. Stetter, the book provides a thorough survey of the field from its controversial beginnings to its ongoing expansion to include aspects of eukaryotic biology. The editors have assembled articles from the premier researchers in this rapidly burgeoning...

  1. Review of physiological effects of cryotherapy.

    Science.gov (United States)

    Kowal, M A

    1983-01-01

    The purpose of this work is to provide the physical therapist with the research documented conclusions that he would find if he were to review the literature on the physiological effects of cold therapy. The conclusions are that the results of the studies reviewed were consistent in describing reductions in musculoskeletal pain, spasm, connective tissue distensibility, intramuscular temperature, nerve conduction velocity, and spasticity (except the initial seconds of application). Other conclusions are that the results of the studies reviewed were inconsistent in describing the changes in swelling, blood flow, heart rate, blood pressure, intraarticular temperature, rheumatoid arthritis, monosynaptic reflex, and the muscle spindle.J Orthop Sports Phys Ther 1983;5(2):66-73.

  2. Platelet mitochondrial function and dysfunction: physiological consequences

    Energy Technology Data Exchange (ETDEWEB)

    Popov, D.

    2015-07-01

    There is a general trend in revisiting mitochondria using the up-to-date technologies that uncovered novel attributes of this organelle, such as the intracellular displacement to locations where an energy supply is needed, the dynamic shape changes and turnover, the initiation of signaling to the rest of the cell, and the ability to crosstalk with other cellular organelles. The in-depth scrutiny of platelet mitochondria role in health and pathology is included within this ongoing revisiting trend. The current article puts into a nutshell the most recent data on platelet mitochondria function and disease-related ion, focusing on generation of stress- and apoptosis-related signaling molecules, overproduction of reactive oxygen species during activation and disease, on the biomarker potential of platelets mitochondria, and their prospective exploitation in translational applications. These novel findings complete the physiological profile of platelets and could have potential therapeutic effectiveness in platelet-associated disorders.

  3. Anatomy and physiology of the esophagus.

    Science.gov (United States)

    Gavaghan, M

    1999-02-01

    Modern diagnosis and treatment of esophageal disease is a result of progress in assessing the anatomy and physiology of the esophagus, as well as refinements in anesthetic and surgical techniques. Esophageal carcinoma spreads rapidly and metastasizes easily. The tendency for early spread and the absence of symptoms result in late diagnosis that reduces treatment options and cure rates. Lifestyle (i.e., use of alcohol and tobacco), nutritional deficiencies, ingestion of nitrosamines, and mutagen-inducing fungi are blamed for cancer of the esophagus. Other pathologic conditions (e.g., achalasia, Barrett's epithelium, gastric reflux, hiatal hernia) are potential contributors to the development of carcinoma. Nurses are in key positions to identify the existence of factors contributing to premalignant or malignant lesions and to educate patients and make the appropriate referrals.

  4. Physiological and cognitive effects of expressive dissonance.

    Science.gov (United States)

    Robinson, Jennifer L; Demaree, Heath A

    2007-02-01

    Emotional well-being depends in part on affect modulation. The present study extends research on emotion regulation by assessing the physiological and cognitive effects of a novel response-focused regulation strategy, termed 'expressive dissonance.' Expressive dissonance refers to the incongruence between an emotional state (e.g., sadness) and a behavioral expression (e.g., a smile). Fifty-five participants watched a series of sad film clips in which they were asked to either naturally watch or express the opposite of what they were feeling. Results suggest that persons using the expressive dissonant strategies evidenced greater sympathetic arousal and performed worse on subsequent memory tasks than persons in the natural-watch conditions.

  5. [Physiological aspects of music and longevity].

    Science.gov (United States)

    Dymnikowa, M

    2015-01-01

    The article provides an overview of the results of studies on the effect of music on the function of various physiological systems of the organism including the nervous, cardiovascular and endocrine systems, also on the effect of Mozart's music and the later mature Baroque music. Particular attention is paid to information on the influence of different kinds of music (classical, jazz and rock), of the nature and of the degree of musical activity (listeners, amateurs and professional performers) on cognitive and behavioral function, on health status, life expectancy and longevity. Structural acoustical attributes of music defining its treatment effect, are described with the comparison of aspects of rock music and of classical music. The article also considers the prospects for using of music in the treatment and prevention of age-associated diseases.

  6. Physiologic Monitoring: Improving Safety or Increasing Risk?

    Science.gov (United States)

    Durbin, Charles G

    2016-08-01

    This paper will present a focused and personal history of physiologic monitoring, beginning with the discovery of modern anesthesia and its development from a technical practice to a scientific discipline. Emphasis will be on the essence of monitoring in the anesthesia evolution, and this work will attempt to answer the question of how to evaluate the impact of monitoring on patient outcome. Understanding that monitors are passive and that only caregivers using monitors can impact outcome is at the crux of this approach to analysis. The limited quality data involving monitoring analysis, including that from pulse oximetry, will be discussed and critiqued. The invention and rapid spread of pulse oximetry will be highlighted and used as an example throughout, but the principles developed will apply to other monitors and patient monitoring in general. The problems created by monitoring alarms will also be discussed. Copyright © 2016 by Daedalus Enterprises.

  7. Physiology and behaviour of marine Thioploca

    DEFF Research Database (Denmark)

    Høgslund, Signe; Revsbech, Niels Peter; Kuenen, Gijs

    2009-01-01

    Among prokaryotes, the large vacuolated marine sulphur bacteria are unique in their ability to store, transport and metabolize significant quantities of sulphur, nitrogen, phosphorus and carbon compounds. In this study, unresolved questions of metabolism, storage management and behaviour were...... when nitrate and nitrite were externally available and when organic carbon was added to incubations. Sulphide addition did not increase carbon dioxide fixation, indicating that Thioploca use excess of sulphide to rapidly accumulate sulphur rather than to accelerate growth. This is interpreted...... as an adaptation to infrequent high sulphate reduction rates in the seabed. The physiology and behaviour of Thioploca are summarized and the adaptations to an environment, dominated by infrequent oxygen availability and periods of high sulphide abundance, are discussed....

  8. Chromatin remodeling in cardiovascular development and physiology.

    Science.gov (United States)

    Han, Pei; Hang, Calvin T; Yang, Jin; Chang, Ching-Pin

    2011-02-04

    Chromatin regulation provides an important means for controlling cardiac gene expression under different physiological and pathological conditions. Processes that direct the development of normal embryonic hearts and pathology of stressed adult hearts may share general mechanisms that govern cardiac gene expression by chromatin-regulating factors. These common mechanisms may provide a framework for us to investigate the interactions among diverse chromatin remodelers/modifiers and various transcription factors in the fine regulation of gene expression, essential for all aspects of cardiovascular biology. Aberrant cardiac gene expression, triggered by a variety of pathological insults, can cause heart diseases in both animals and humans. The severity of cardiomyopathy and heart failure correlates strongly with abnormal cardiac gene expression. Therefore, controlling cardiac gene expression presents a promising approach to the treatment of human cardiomyopathy. This review focuses on the roles of ATP-dependent chromatin-remodeling factors and chromatin-modifying enzymes in the control of gene expression during cardiovascular development and disease.

  9. Biochemistry and physiology of anaerobic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-18

    We welcome you to The Power of Anaerobes. This conference serves two purposes. One is to celebrate the life of Harry D. Peck, Jr.,who was born May 18, 1927 and would have celebrated his 73rd birthday at this conference. He died November 20, 1998. The second is to gather investigators to exchange views within the realm of anaerobic microbiology, an area in which tremendous progress has been seen during recent years. It is sufficient to mention discoveries of a new form of life (the archaea), hyper or extreme thermophiles, thermophilic alkaliphiles and anaerobic fungi. With these discoveries has come a new realization about physiological and metabolic properties of microorganisms, and this in turn has demonstrated their importance for the development, maintenance and sustenance of life on Earth.

  10. Physiology of temperature regulation: comparative aspects.

    Science.gov (United States)

    Bicego, Kênia C; Barros, Renata C H; Branco, Luiz G S

    2007-07-01

    Few environmental factors have a larger influence on animal energetics than temperature, a fact that makes thermoregulation a very important process for survival. In general, endothermic species, i.e., mammals and birds, maintain a constant body temperature (Tb) in fluctuating environmental temperatures using autonomic and behavioural mechanisms. Most of the knowledge on thermoregulatory physiology has emerged from studies using mammalian species, particularly rats. However, studies with all vertebrate groups are essential for a more complete understanding of the mechanisms involved in the regulation of Tb. Ectothermic vertebrates-fish, amphibians and reptiles-thermoregulate essentially by behavioural mechanisms. With few exceptions, both endotherms and ectotherms develop fever (a regulated increase in Tb) in response to exogenous pyrogens, and regulated hypothermia (anapyrexia) in response to hypoxia. This review focuses on the mechanisms, particularly neuromediators and regions in the central nervous system, involved in thermoregulation in vertebrates, in conditions of euthermia, fever and anapyrexia.

  11. Ozone Damages to Mediterranean Crops: Physiological Responses

    Directory of Open Access Journals (Sweden)

    Massimo Fagnano

    2011-02-01

    Full Text Available In this brief review we analyzed some aspects of tropospheric ozone damages to crop plants. Specifically, we addressed this issue to Mediterranean environments, where plant response to multiple stresses may either exacerbate or counteract deleterious ozone effects. After discussing the adequacy of current models to predict ozone damages to Mediterranean crops, we present a few examples of physiological responses to drought and salinity stress that generally overlap with seasonal ozone peaks in Southern Italy. The co-existence of multiple stresses is then analyzed in terms of stomatal vs. non-stomatal control of ozone damages. Recent results on osmoprotectant feeding experiments, as a non-invasive strategy to uncouple stomatal vs. non stomatal contribution to ozone protection, are also presented. In the final section, we discuss critical needs in ozone research and the great potential of plant model systems to unravel multiple stress responses in agricultural crops.

  12. Teaching baroreflex physiology to medical students

    DEFF Research Database (Denmark)

    Berg, Ronan M G; Plovsing, Ronni R.; Damgaard, Morten

    2012-01-01

    Quiz-based and collaborative teaching strategies have previously been found to be efficient for the improving meaningful learning of physiology during lectures. These approaches have, however, not been investigated during laboratory exercises. In the present study, we compared the impact of solving...... questions, and two integrated questions. The integrated questions were of moderate and advanced difficulty, respectively. Finally, students completed an evaluation form. Intervention group I reached the highest total test scores and proved best at answering the integrated question of advanced difficulty....... Moreover, there was an overall difference between groups for student evaluations of the quality of the teaching, which was highest for intervention group II. In conclusion, solving quizzes individually during a laboratory exercise may enhance learning, whereas solving quizzes in groups is associated...

  13. The foveal 'crowding' effect: physics or physiology?

    Science.gov (United States)

    Hess, R F; Dakin, S C; Kapoor, N

    2000-01-01

    It has been known for some time that both foveal and peripheral visual acuity is higher for single letters than for letters in a row. Early work showed that this was due to the destructive interaction of adjacent contours (termed 'crowding' or contour interaction). It has been assumed to have a neural basis and a number of competing explanations have been advanced which implicate either high-level or low-level stages of visual processing. Our results suggest a much simpler explanation, one primarily determined by the physics of the stimulus rather than the physiology of the visual system. We show that, under conditions of contour interaction or 'crowding', the most relevant physical spatial frequency band of the letter is displaced to higher spatial frequencies and that foveal vision tracks this change in spatial scale.

  14. Nonlinear Analysis of Physiological Time Series

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-fang; PENG Yu-hua; XUE Yu-li; HAN Min

    2007-01-01

    Abstract.The heart rate variability could be explained by a low-dimensional governing mechanism. There has been increasing interest in verifying and understanding the coupling between the respiration and the heart rate. In this paper we use the nonlinear detection method to detect the nonlinear deterministic component in the physiological time series by a single variable series and two variables series respectively, and use the conditional information entropy to analyze the correlation between the heart rate, the respiration and the blood oxygen concentration. The conclusions are that there is the nonlinear deterministic component in the heart rate data and respiration data, and the heart rate and the respiration are two variables originating from the same underlying dynamics.

  15. Phosphodiesterases in endocrine physiology and disease.

    Science.gov (United States)

    Vezzosi, Delphine; Bertherat, Jérôme

    2011-08-01

    The cAMP-protein kinase A pathway plays a central role in the development and physiology of endocrine tissues. cAMP mediates the intracellular effects of numerous peptide hormones. Various cellular and molecular alterations of the cAMP-signaling pathway have been observed in endocrine diseases. Phosphodiesterases (PDEs) are key regulatory enzymes of intracellular cAMP levels. Indeed, PDEs are the only known mechanism for inactivation of cAMP by catalysis to 5'-AMP. It has been suggested that disruption of PDEs could also have a role in the pathogenesis of many endocrine diseases. This review summarizes the most recent advances concerning the role of the PDEs in the physiopathology of endocrine diseases. The potential significance of this knowledge can be easily envisaged by the development of drugs targeting specific PDEs.

  16. Asthma in pregnancy: Physiology, diagnosis, and management.

    Science.gov (United States)

    Kelly, William; Massoumi, Ali; Lazarus, Angeline

    2015-05-01

    Asthma is a common, potentially serious, medical condition that affects an estimated 8% of pregnant patients, with 4% of all pregnant patients experiencing an exacerbation in the past year. Practitioners must be able to diagnose, educate, and treat such patients as they undergo significant physiological and immunologic change. But staying current can be challenging given over 3000 citations for "asthma and pregnancy" in a recent PubMed search, with 750 described as review articles. Patients have even more difficulty navigating information, with 29 million Google search results for this same query and 1.2 million alone for the question whether asthma medications are safe during pregnancy. This review provides brief answers to important management questions followed by supporting background literature.

  17. Microengineered physiological biomimicry: organs-on-chips.

    Science.gov (United States)

    Huh, Dongeun; Torisawa, Yu-suke; Hamilton, Geraldine A; Kim, Hyun Jung; Ingber, Donald E

    2012-06-21

    Microscale engineering technologies provide unprecedented opportunities to create cell culture microenvironments that go beyond current three-dimensional in vitro models by recapitulating the critical tissue-tissue interfaces, spatiotemporal chemical gradients, and dynamic mechanical microenvironments of living organs. Here we review recent advances in this field made over the past two years that are focused on the development of 'Organs-on-Chips' in which living cells are cultured within microfluidic devices that have been microengineered to reconstitute tissue arrangements observed in living organs in order to study physiology in an organ-specific context and to develop specialized in vitro disease models. We discuss the potential of organs-on-chips as alternatives to conventional cell culture models and animal testing for pharmaceutical and toxicology applications. We also explore challenges that lie ahead if this field is to fulfil its promise to transform the future of drug development and chemical safety testing.

  18. Alpha-Ketoglutarate: Physiological Functions and Applications.

    Science.gov (United States)

    Wu, Nan; Yang, Mingyao; Gaur, Uma; Xu, Huailiang; Yao, Yongfang; Li, Diyan

    2016-01-01

    Alpha-ketoglutarate (AKG) is a key molecule in the Krebs cycle determining the overall rate of the citric acid cycle of the organism. It is a nitrogen scavenger and a source of glutamate and glutamine that stimulates protein synthesis and inhibits protein degradation in muscles. AKG as a precursor of glutamate and glutamine is a central metabolic fuel for cells of the gastrointestinal tract as well. AKG can decrease protein catabolism and increase protein synthesis to enhance bone tissue formation in the skeletal muscles and can be used in clinical applications. In addition to these health benefits, a recent study has shown that AKG can extend the lifespan of adult Caenorhabditis elegans by inhibiting ATP synthase and TOR. AKG not only extends lifespan, but also delays age-related disease. In this review, we will summarize the advances in AKG research field, in the content of its physiological functions and applications.

  19. The human hair: from anatomy to physiology.

    Science.gov (United States)

    Buffoli, Barbara; Rinaldi, Fabio; Labanca, Mauro; Sorbellini, Elisabetta; Trink, Anna; Guanziroli, Elena; Rezzani, Rita; Rodella, Luigi F

    2014-03-01

    Hair is a unique character of mammals and has several functions, from protection of the skin to sexual and social communication. In literature, there are various studies about hair that take into consideration different aspects within many fields of science, including biology, dermatology, cosmetics, forensic sciences, and medicine. We carried out a search of studies published in PubMed up to 2013. In this review, we summarized the principal anatomical and physiological aspects of the different types of human hair, and we considered the clinical significance of the different structures and the distribution of the hair in the human body. This review could be the basis for improvement and progression in the field of hair research. © 2013 The International Society of Dermatology.

  20. McArdle Disease and Exercise Physiology

    Directory of Open Access Journals (Sweden)

    Yu Kitaoka

    2014-02-01

    Full Text Available McArdle disease (glycogen storage disease Type V; MD is a metabolic myopathy caused by a deficiency in muscle glycogen phosphorylase. Since muscle glycogen is an important fuel for muscle during exercise, this inborn error of metabolism provides a model for understanding the role of glycogen in muscle function and the compensatory adaptations that occur in response to impaired glycogenolysis. Patients with MD have exercise intolerance with symptoms including premature fatigue, myalgia, and/or muscle cramps. Despite this, MD patients are able to perform prolonged exercise as a result of the “second wind” phenomenon, owing to the improved delivery of extra-muscular fuels during exercise. The present review will cover what this disease can teach us about exercise physiology, and particularly focuses on the compensatory pathways for energy delivery to muscle in the absence of glycogenolysis.

  1. Archaea: Evolution, Physiology, and Molecular Biology

    DEFF Research Database (Denmark)

    Introduced by Crafoord Prize winner Carl Woese, this volume combines reviews of the major developments in archaeal research over the past 10-15 years with more specialized articles dealing with important recent breakthroughs. Drawing on major themes presented at the June 2005 meeting held in Muni...... and technological context, and include accounts of cutting-edge research developments. The book spans archaeal evolution, physiology, and molecular and cellular biology and will be an essential reference for both graduate students and researchers....... to honor the archaea pioneers Wolfram Zillig and Karl O. Stetter, the book provides a thorough survey of the field from its controversial beginnings to its ongoing expansion to include aspects of eukaryotic biology. The editors have assembled articles from the premier researchers in this rapidly burgeoning...

  2. Heartwarming memories: Nostalgia maintains physiological comfort.

    Science.gov (United States)

    Zhou, Xinyue; Wildschut, Tim; Sedikides, Constantine; Chen, Xiaoxi; Vingerhoets, Ad J J M

    2012-08-01

    Nostalgia, a sentimental longing or wistful affection for the past, is a predominantly positive and social emotion. Recent evidence suggests that nostalgia maintains psychological comfort. Here, we propose, and document in five methodologically diverse studies, a broader homeostatic function for nostalgia that also encompasses the maintenance of physiological comfort. We show that nostalgia--an emotion with a strong connotation of warmth--is triggered by coldness. Participants reported stronger nostalgia on colder (vs. warmer) days and in a cold (vs. neutral or warm) room. Nostalgia, in turn, modulates the interoceptive feeling of temperature. Higher levels of music-evoked nostalgia predicted increased physical warmth, and participants who recalled a nostalgic (vs. ordinary autobiographical) event perceived ambient temperature as higher. Finally, and consistent with the close central nervous system integration of temperature and pain sensations, participants who recalled a nostalgic (vs. ordinary autobiographical) event evinced greater tolerance to noxious cold.

  3. Physiologic assessment of coronary artery fistula

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.C.; Beauvais, J. (Creighton Univ., Omaha, NE (USA))

    1991-01-01

    Coronary artery fistula is an uncommon clinical entity. The most common coronary artery fistula is from the right coronary artery to the right side of the heart, and it is less frequent to the pulmonary artery. The effect of a coronary artery fistula may be physiologically significant because of the steal phenomenon resulting in coronary ischemia. Based on published reports, it is recommended that patients with congenital coronary artery fistulas be considered candidates for elective surgical correction to prevent complications including development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and coronary aneurysm formation with rupture or embolization. A patient is presented in whom treadmill-exercise thallium imaging was effective in determining the degree of coronary steal from a coronary artery fistula, leading to successful corrective surgery.

  4. Musculoskeletal mechanics: a foundation of motor physiology.

    Science.gov (United States)

    Nichols, T Richard

    2002-01-01

    The design of the musculoskeletal system has always been a major consideration in the interpretation of experiments on the motor system. However, as motor physiology progresses toward a more comprehensive picture of motor behaviour, the study of the musculoskeletal system has of necessity, and of interest, come to depend more and more on the quantitative methods of biomechanics. Biomechanical studies have led to new hypotheses about the design of the motor system and biomechanical considerations have provided important tests of existing hypotheses concerning the neural control of movement. These hypotheses include global issues such as redundancy and encoded variables as well as specific hypotheses such as Stiffness Regulation, Selective Recruitment and the concept of Flexor Reflex Afferents.

  5. Physiology of psychoneuroimmunology: a personal view.

    Science.gov (United States)

    Besedovsky, Hugo O; Rey, Adriana Del

    2007-01-01

    This article offers a personal view on how the concept of the existence of a network of immune-neuro-endocrine interactions has evolved in the last 30 years. The main topic addressed is the relevance of the exchange of signals between the immune, endocrine and nervous systems for immunoregulation and brain functions. Particular emphasis is given to circuits involving immune cell products, the hypothalamus-pituitary-adrenal axis and the sympathetic nervous system. The operation of these circuits can affect immune functions and the course of inflammatory, autoimmune and infectious diseases. We also discuss increasing evidence that brain-born cytokines play an important role in brain physiology and in the integration of the immune-neuro-endocrine network.

  6. Anatomy and physiology of the velopharyngeal mechanism.

    Science.gov (United States)

    Perry, Jamie L

    2011-05-01

    Understanding the normal anatomy and physiology of the velopharyngeal mechanism is the first step in providing appropriate diagnosis and treatment for children born with cleft lip and palate. The velopharyngeal mechanism consists of a muscular valve that extends from the posterior surface of the hard palate (roof of mouth) to the posterior pharyngeal wall and includes the velum (soft palate), lateral pharyngeal walls (sides of the throat), and the posterior pharyngeal wall (back wall of the throat). The function of the velopharyngeal mechanism is to create a tight seal between the velum and pharyngeal walls to separate the oral and nasal cavities for various purposes, including speech. Velopharyngeal closure is accomplished through the contraction of several velopharyngeal muscles including the levator veli palatini, musculus uvulae, superior pharyngeal constrictor, palatopharyngeus, palatoglossus, and salpingopharyngeus. The tensor veli palatini is thought to be responsible for eustachian tube function.

  7. Physiologic Status Monitoring via the Gastrointestinal Tract.

    Science.gov (United States)

    Traverso, G; Ciccarelli, G; Schwartz, S; Hughes, T; Boettcher, T; Barman, R; Langer, R; Swiston, A

    2015-01-01

    Reliable, real-time heart and respiratory rates are key vital signs used in evaluating the physiological status in many clinical and non-clinical settings. Measuring these vital signs generally requires superficial attachment of physically or logistically obtrusive sensors to subjects that may result in skin irritation or adversely influence subject performance. Given the broad acceptance of ingestible electronics, we developed an approach that enables vital sign monitoring internally from the gastrointestinal tract. Here we report initial proof-of-concept large animal (porcine) experiments and a robust processing algorithm that demonstrates the feasibility of this approach. Implementing vital sign monitoring as a stand-alone technology or in conjunction with other ingestible devices has the capacity to significantly aid telemedicine, optimize performance monitoring of athletes, military service members, and first-responders, as well as provide a facile method for rapid clinical evaluation and triage.

  8. Physiological Factors Analysis in Unpressurized Aircraft Cabins

    Science.gov (United States)

    Patrao, Luis; Zorro, Sara; Silva, Jorge

    2016-11-01

    Amateur and sports flight is an activity with growing numbers worldwide. However, the main cause of flight incidents and accidents is increasingly pilot error, for a number of reasons. Fatigue, sleep issues and hypoxia, among many others, are some that can be avoided, or, at least, mitigated. This article describes the analysis of psychological and physiological parameters during flight in unpressurized aircraft cabins. It relates cerebral oximetry and heart rate with altitude, as well as with flight phase. The study of those parameters might give clues on which variations represent a warning sign to the pilot, thus preventing incidents and accidents due to human factors. Results show that both cerebral oximetry and heart rate change along the flight and altitude in the alert pilot. The impaired pilot might not reveal these variations and, if this is detected, he can be warned in time.

  9. NASA Exercise Physiology and Countermeasures Project Overview

    Science.gov (United States)

    Loerch, Linda; Ploutz-Snyder, Lori

    2009-01-01

    Efficient exercise countermeasures are necessary to offset or minimize spaceflight-induced deconditioning and to maximize crew performance of mission tasks. These countermeasure protocols should use the fewest crew and vehicle resources. NASA s Exercise Physiology and Countermeasures (ExPC) Project works to identify, collect, interpret, and summarize evidence that results in effective exercise countermeasure protocols which protect crew health and performance during International Space Station (ISS) and future exploration-class missions. The ExPC and NASA s Human Research Program are sponsoring multiple studies to evaluate and improve the efficacy of spaceflight exercise countermeasures. First, the Project will measure maximal aerobic capacity (VO2max) during cycle ergometry before, during, and after ISS missions. Second, the Project is sponsoring an evaluation of a new prototype harness that offers improved comfort and increased loading during treadmill operations. Third, the Functional Tasks Test protocol will map performance of anticipated lunar mission tasks with physiologic systems before and after short and long-duration spaceflight, to target system contributions and the tailoring of exercise protocols to maximize performance. In addition to these studies that are actively enrolling crewmember participants, the ExPC is planning new studies that include an evaluation of a higher-intensity/lower-volume exercise countermeasure protocol aboard the ISS using the Advanced Resistive Exercise Device and second-generation treadmill, studies that evaluate bone loading during spaceflight exercise, and ground-based studies that focus on fitness for duty standards required to complete lunar mission tasks and for which exercise protocols need to protect. Summaries of these current and future studies and strategies will be provided to international colleagues for knowledge sharing and possible collaboration.

  10. Garlic: nature's protection against physiological threats.

    Science.gov (United States)

    Butt, Masood Sadiq; Sultan, Muhammad Tauseef; Butt, Mehmood S; Iqbal, Javaid

    2009-06-01

    Currently reliance on natural products is gaining popularity to combat various physiological threats including oxidative stress, cardiovascular complexities, cancer insurgence, and immune dysfunction. The use of traditional remedies may encounter more frequently due to an array of scientific evidence in their favor. Garlic (Allium sativum) holds a unique position in history and was recognized for its therapeutic potential. Recent advancements in the field of immunonutrition, physiology, and pharmacology further explored its importance as a functional food against various pathologies. Extensive research work has been carried out on the health promoting properties of garlic, often referred to its sulfur containing metabolites i.e. allicin and its derivatives. Garlic in its preparations are effective against health risks and even used as dietary supplements such as age garlic extract (AGE) and garlic oil etc. Its components/formulations can scavenge free radicals and protect membranes from damage and maintains cell integrity. It also provides cardiovascular protection mediated by lowering of cholesterol, blood pressure, anti-platelet activities, and thromboxane formation thus providing protection against atherosclerosis and associated disorders. Besides this, it possesses antimutagenic and antiproliferative properties that are interesting in chemopreventive interventions. Several mechanisms have been reviewed in this context like activation of detoxification phase-I and II enzymes, reactive oxygen species (ROS) generation, and reducing DNA damage etc. Garlic could be useful in preventing the suppression of immune response associated with increased risk of malignancy as it stimulates the proliferation of lymphocytes, macrophage phagocytosis, stimulates the release of interleukin-2, tumor necrosis factor-alpha and interferon-gamma, and enhances natural killer cells. In this paper much emphasis has been placed on garlic's ability to ameliorate oxidative stress, core role

  11. Physiological hydrostatic pressure protects endothelial monolayer integrity.

    Science.gov (United States)

    Müller-Marschhausen, K; Waschke, J; Drenckhahn, D

    2008-01-01

    Endothelial monolayer integrity is required to maintain endothelial barrier functions and has found to be impaired in several disorders like inflammatory edema, allergic shock, or artherosclerosis. Under physiologic conditions in vivo, endothelial cells are exposed to mechanical forces such as hydrostatic pressure, shear stress, and cyclic stretch. However, insight into the effects of hydrostatic pressure on endothelial cell biology is very limited at present. Therefore, in this study, we tested the hypothesis that physiological hydrostatic pressure protects endothelial monolayer integrity in vitro. We investigated the protective efficacy of hydrostatic pressure in microvascular myocardial endothelial (MyEnd) cells and macrovascular pulmonary artery endothelial cells (PAECs) by the application of selected pharmacological agents known to alter monolayer integrity in the absence or presence of hydrostatic pressure. In both endothelial cell lines, extracellular Ca(2+) depletion by EGTA was followed by a loss of vascular-endothelial cadherin (VE-caherin) immunostaining at cell junctions. However, hydrostatic pressure (15 cmH(2)O) blocked this effect of EGTA. Similarly, cytochalasin D-induced actin depolymerization and intercellular gap formation and cell detachment in response to the Ca(2+)/calmodulin antagonist trifluperazine (TFP) as well as thrombin-induced cell dissociation were also reduced by hydrostatic pressure. Moreover, hydrostatic pressure significantly reduced the loss of VE-cadherin-mediated adhesion in response to EGTA, cytochalasin D, and TFP in MyEnd cells as determined by laser tweezer trapping using VE-cadherin-coated microbeads. In caveolin-1-deficient MyEnd cells, which lack caveolae, hydrostatic pressure did not protect monolayer integrity compromised by EGTA, indicating that caveolae-dependent mechanisms are involved in hydrostatic pressure sensing and signaling.

  12. Leptin in human physiology and pathophysiology.

    Science.gov (United States)

    Mantzoros, Christos S; Magkos, Faidon; Brinkoetter, Mary; Sienkiewicz, Elizabeth; Dardeno, Tina A; Kim, Sang-Yong; Hamnvik, Ole-Petter R; Koniaris, Anastasia

    2011-10-01

    Leptin, discovered through positional cloning 15 years ago, is an adipocyte-secreted hormone with pleiotropic effects in the physiology and pathophysiology of energy homeostasis, endocrinology, and metabolism. Studies in vitro and in animal models highlight the potential for leptin to regulate a number of physiological functions. Available evidence from human studies indicates that leptin has a mainly permissive role, with leptin administration being effective in states of leptin deficiency, less effective in states of leptin adequacy, and largely ineffective in states of leptin excess. Results from interventional studies in humans demonstrate that leptin administration in subjects with congenital complete leptin deficiency or subjects with partial leptin deficiency (subjects with lipoatrophy, congenital or related to HIV infection, and women with hypothalamic amenorrhea) reverses the energy homeostasis and neuroendocrine and metabolic abnormalities associated with these conditions. More specifically, in women with hypothalamic amenorrhea, leptin helps restore abnormalities in hypothalamic-pituitary-peripheral axes including the gonadal, thyroid, growth hormone, and to a lesser extent adrenal axes. Furthermore, leptin results in resumption of menses in the majority of these subjects and, in the long term, may increase bone mineral content and density, especially at the lumbar spine. In patients with congenital or HIV-related lipoatrophy, leptin treatment is also associated with improvements in insulin sensitivity and lipid profile, concomitant with reduced visceral and ectopic fat deposition. In contrast, leptin's effects are largely absent in the obese hyperleptinemic state, probably due to leptin resistance or tolerance. Hence, another emerging area of research pertains to the discovery and/or usefulness of leptin sensitizers. Results from ongoing studies are expected to further increase our understanding of the role of leptin and the potential clinical

  13. Physiological basis for human autonomic rhythms

    Science.gov (United States)

    Eckberg, D. L.

    2000-01-01

    Oscillations of arterial pressures, heart periods, and muscle sympathetic nerve activity have been studied intensively in recent years to explore otherwise obscure human neurophysiological mechanisms. The best-studied rhythms are those occurring at breathing frequencies. Published evidence indicates that respiratory fluctuations of muscle sympathetic nerve activity and electrocardiographic R-R intervals result primarily from the action of a central 'gate' that opens during expiration and closes during inspiration. Parallel respiratory fluctuations of arterial pressures and R-R intervals are thought to be secondary to arterial baroreflex physiology: changes in systolic pressure provoke changes in the R-R interval. However, growing evidence suggests that these parallel oscillations result from the influence of respiration on sympathetic and vagal-cardiac motoneurones rather than from baroreflex physiology. There is a rapidly growing literature on the use of mathematical models of low- and high-frequency (respiratory) R-R interval fluctuations in characterizing instantaneous 'sympathovagal balance'. The case for this approach is based primarily on measurements made with patients in upright tilt. However, the strong linear relation between such measures as the ratio of low- to high-frequency R-R interval oscillations and the angle of the tilt reflects exclusively the reductions of the vagal (high-frequency) component. As the sympathetic component does not change in tilt, the low- to high-frequency R-R interval ratio provides no proof that sympathetic activity increases. Moreover, the validity of extrapolating from measurements performed during upright tilt to measurements during supine rest has not been established. Nonetheless, it is clear that measures of heart rate variability provide important prognostic information in patients with cardiovascular diseases. It is not known whether reduced heart rate variability is merely a marker for the severity of disease or a

  14. Physiology and Acoustics of Inspiratory Phonation.

    Science.gov (United States)

    Vanhecke, Françoise; Lebacq, Jean; Moerman, Mieke; Manfredi, Claudia; Raes, Godfried-Willem; DeJonckere, Philippe H

    2016-11-01

    Inspiratory phonation (IP) means phonating with inspiratory airflow. Some vocalists remarkably master this technique, to such an extent that it offers new dramatic, aesthetic, and functional possibilities in singing specific contemporary music. The present study aims to a better understanding of the physiological backgrounds of IP. A total of 51 inhaling utterances were compared with 61 exhaling utterances in a professional soprano highly skilled in inhaling singing, by means of high-speed single-line scanning and advanced acoustic analysis. Ranges of intensity and Fo were kept similar. The main differences are: (1) an inversion of the mucosal wave, (2) a smaller closed quotient in IP, (3) a larger opening/closing quotient in IP with the additional difference that in IP, the quotient is larger than 1 (opening slower than closing), whereas it is less than 1 in expiratory mode (opening faster than closing), (4) a larger vocal-fold excursion in IP, (5) higher values of adaptive normalized noise energy in IP, and (6) a steeper slope of harmonic peaks in IP. However, jitter values are similar (within normal range), as well as damping ratios and central formant frequencies. The two voicing modes cannot be differentiated by blind listening. The basic physiological mechanisms are comparable in both voicing modes, although with specific differences. IP is actually to be considered as an "extended vocal technique," a term applied to vocalization in art music, which falls outside of traditional classical singing styles, but with remarkable possibilities in skilled vocalists. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Sleep physiology and pathology: pertinence to psychiatry.

    Science.gov (United States)

    Soldatos, Constantin R; Paparrigopoulos, Thomas J

    2005-08-01

    Sleep should not be considered a behavioural state characterized by brain inertia; instead, it is a highly dynamic process involving numerous brainstem areas and all physiological systems of the body. Our understanding of the underlying mechanisms responsible for sleep regulation has considerably advanced since the discovery of rapid eye movement (REM) sleep, about half a century ago. Based on standardized electroencephalographic, electro-oculographic and electromyographic features, two distinct main states periodically alternating throughout the night have been identified: REM and non-REM sleep; the latter is further distinguished into stages 1, 2, 3 and 4. Computerized analysis of sleep recordings yielded more detailed information on sleep physiology and pathology. Although still preliminary, neuroimaging studies promise to elucidate the functional alterations of neuronal substrates during sleep. Regarding sleep disorders, which account for a substantial individual and socio-economic burden, considerable progress has been achieved in terms of their classification, assessment, clinical diagnosis and treatment. Specific sleep disorders within the three major categories, that is, 'dysomnias', 'parasomnias', and 'sleep disorders associated with mental, neurologic, or other medical conditions', exhibit characteristic clinical features; sleep laboratory recordings considerably assist to definitely diagnose several among them. Pertinence of sleep medicine for psychiatrists is obvious, taking into consideration that psychiatric disorders account for the largest diagnostic group of patients with sleep problems. In fact, the basics of this interdisciplinary field should be of special concern both to medical students and clinicians of diverse backgrounds who are interested in acquiring the necessary skills to globally and comprehensively understand and eventually effectively treat their patients.

  16. Leptin in human physiology and pathophysiology

    Science.gov (United States)

    Magkos, Faidon; Brinkoetter, Mary; Sienkiewicz, Elizabeth; Dardeno, Tina A.; Kim, Sang-Yong; Hamnvik, Ole-Petter R.; Koniaris, Anastasia

    2011-01-01

    Leptin, discovered through positional cloning 15 years ago, is an adipocyte-secreted hormone with pleiotropic effects in the physiology and pathophysiology of energy homeostasis, endocrinology, and metabolism. Studies in vitro and in animal models highlight the potential for leptin to regulate a number of physiological functions. Available evidence from human studies indicates that leptin has a mainly permissive role, with leptin administration being effective in states of leptin deficiency, less effective in states of leptin adequacy, and largely ineffective in states of leptin excess. Results from interventional studies in humans demonstrate that leptin administration in subjects with congenital complete leptin deficiency or subjects with partial leptin deficiency (subjects with lipoatrophy, congenital or related to HIV infection, and women with hypothalamic amenorrhea) reverses the energy homeostasis and neuroendocrine and metabolic abnormalities associated with these conditions. More specifically, in women with hypothalamic amenorrhea, leptin helps restore abnormalities in hypothalamic-pituitary-peripheral axes including the gonadal, thyroid, growth hormone, and to a lesser extent adrenal axes. Furthermore, leptin results in resumption of menses in the majority of these subjects and, in the long term, may increase bone mineral content and density, especially at the lumbar spine. In patients with congenital or HIV-related lipoatrophy, leptin treatment is also associated with improvements in insulin sensitivity and lipid profile, concomitant with reduced visceral and ectopic fat deposition. In contrast, leptin's effects are largely absent in the obese hyperleptinemic state, probably due to leptin resistance or tolerance. Hence, another emerging area of research pertains to the discovery and/or usefulness of leptin sensitizers. Results from ongoing studies are expected to further increase our understanding of the role of leptin and the potential clinical

  17. In silico modelling of physiologic systems.

    Science.gov (United States)

    Colquitt, Richard B; Colquhoun, Douglas A; Thiele, Robert H

    2011-12-01

    In silico modelling, in which computer models are developed to model a pharmacologic or physiologic process, is a logical extension of controlled in vitro experimentation. It is the natural result of the explosive increase in computing power available to the research scientist at continually decreasing cost. In silico modelling combines the advantages of both in vivo and in vitro experimentation, without subjecting itself to the ethical considerations and lack of control associated with in vivo experiments. Unlike in vitro experiments, which exist in isolation, in silico models allow the researcher to include a virtually unlimited array of parameters, which render the results more applicable to the organism as a whole. In silico modelling is best known for its extensive use in pharmacokinetic experimentation, the best-known example of which is the development of the three-compartment model. In addition, complex in silico models have been applied to pathophysiological problems to provide information which cannot be obtained practically or ethically by traditional clinical research methods. These experiments have led to the development of significant insights in subject matters ranging from pure physiology to congenital heart surgery, obstetric anaesthesia airway management, mechanical ventilation and cardiopulmonary bypass/ventricular support devices. The utility of these models is based on both the validity of the model framework as well as the corresponding assumptions. In vivo experimentation has validated some, but not all of the in silico strategies employed. We present a review illustrating by example how in silico modelling has been applied to a number of cardio-respiratory problems in states of health and disease, the purpose of which is to give the reader a sense of the complexity and assumptions which underlie this diverse and underappreciated research strategy, as well as an introduction to a research strategy that will likely continue to grow in

  18. Earthing the human body influences physiologic processes.

    Science.gov (United States)

    Sokal, Karol; Sokal, Pawel

    2011-04-01

    This study was designed to answer the question: Does the contact of the human organism with the Earth via a copper conductor affect physiologic processes? Subjects and experiments: Five (5) experiments are presented: experiment 1-effect of earthing on calcium-phosphate homeostasis and serum concentrations of iron (N = 84 participants); experiment 2-effect of earthing on serum concentrations of electrolytes (N = 28); experiment 3-effect of earthing on thyroid function (N = 12); experiment 4-effect of earthing on glucose concentration (N = 12); experiment 5-effect of earthing on immune response to vaccine (N = 32). Subjects were divided into two groups. One (1) group of people was earthed, while the second group remained without contact with the Earth. Blood and urine samples were examined. Earthing of an electrically insulated human organism during night rest causes lowering of serum concentrations of iron, ionized calcium, inorganic phosphorus, and reduction of renal excretion of calcium and phosphorus. Earthing during night rest decreases free tri-iodothyronine and increases free thyroxine and thyroid-stimulating hormone. The continuous earthing of the human body decreases blood glucose in patients with diabetes. Earthing decreases sodium, potassium, magnesium, iron, total protein, and albumin concentrations while the levels of transferrin, ferritin, and globulins α1, α2, β, and γ increase. These results are statistically significant. Earthing the human body influences human physiologic processes. This influence is observed during night relaxation and during physical activity. Effect of the earthing on calcium-phosphate homeostasis is the opposite of that which occurs in states of weightlessness. It also increases the activity of catabolic processes. It may be the primary factor regulating endocrine and nervous systems.

  19. Physiological conjunction of allelochemicals and desert plants.

    Science.gov (United States)

    Yosef Friedjung, Avital; Choudhary, Sikander Pal; Dudai, Nativ; Rachmilevitch, Shimon

    2013-01-01

    Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds) were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  20. Physiological conjunction of allelochemicals and desert plants.

    Directory of Open Access Journals (Sweden)

    Avital Yosef Friedjung

    Full Text Available Plants exchange signals with other physical and biological entities in their habitat, a form of communication termed allelopathy. The underlying principles of allelopathy and secondary-metabolite production are still poorly understood, especially in desert plants. The coordination and role of secondary metabolites were examined as a cause of allelopathy in plants thriving under arid and semiarid soil conditions. Desert plant species, Origanum dayi, Artemisia sieberi and Artemisia judaica from two different sources (cultivar cuttings and wild seeds were studied in their natural habitats. Growth rate, relative water content, osmotic potential, photochemical efficiency, volatile composition and vital factors of allelopathy were analyzed at regular intervals along four seasons with winter showing optimum soil water content and summer showing water deficit conditions. A comprehensive analysis of the volatile composition of the leaves, ambient air and soil in the biological niche of the plants under study was carried out to determine the effects of soil water conditions and sample plants on the surrounding flora. Significant morpho-physiological changes were observed across the seasons and along different soil water content. Metabolic analysis showed that water deficit was the key for driving selective metabolomic shifts. A. judaica showed the least metabolic shifts, while A. sieberi showed the highest shifts. All the species exhibited high allelopathic effects; A. judaica displayed relatively higher growth-inhibition effects, while O. dayi showed comparatively higher germination-inhibition effects in germination assays. The current study may help in understanding plant behavior, mechanisms underlying secondary-metabolite production in water deficit conditions and metabolite-physiological interrelationship with allelopathy in desert plants, and can help cull economic benefits from the produced volatiles.

  1. The Graphical Representation of the Digital Astronaut Physiology Backbone

    Science.gov (United States)

    Briers, Demarcus

    2010-01-01

    This report summarizes my internship project with the NASA Digital Astronaut Project to analyze the Digital Astronaut (DA) physiology backbone model. The Digital Astronaut Project (DAP) applies integrated physiology models to support space biomedical operations, and to assist NASA researchers in closing knowledge gaps related to human physiologic responses to space flight. The DA physiology backbone is a set of integrated physiological equations and functions that model the interacting systems of the human body. The current release of the model is HumMod (Human Model) version 1.5 and was developed over forty years at the University of Mississippi Medical Center (UMMC). The physiology equations and functions are scripted in an XML schema specifically designed for physiology modeling by Dr. Thomas G. Coleman at UMMC. Currently it is difficult to examine the physiology backbone without being knowledgeable of the XML schema. While investigating and documenting the tags and algorithms used in the XML schema, I proposed a standard methodology for a graphical representation. This standard methodology may be used to transcribe graphical representations from the DA physiology backbone. In turn, the graphical representations can allow examination of the physiological functions and equations without the need to be familiar with the computer programming languages or markup languages used by DA modeling software.

  2. Love-hate for man-machine metaphors in Soviet physiology: from Pavlov to "physiological cybernetics".

    Science.gov (United States)

    Gerovitch, Slava

    2002-06-01

    This article reinterprets the debate between orthodox followers of the Pavlovian reflex theory and Soviet "cybernetic physiologists" in the 1950s and 60s as a clash of opposing man-machine metaphors. While both sides accused each other of "mechanistic," reductionist methodology, they did not see anything "mechanistic" about their own central metaphors: the telephone switchboard metaphor for nervous activity (the Pavlovians), and the analogies between the human brain and a computer (the cyberneticians). I argue that the scientific utility of machine analogies was closely intertwined with their philosophical and political meanings and that new interpretations of these metaphors emerged as a result of political conflicts and a realignment of forces within the scientific community and in society at large. I suggest that the constant travel of man-machine analogies, back and forth between physiology and technology has blurred the traditional categories of the "mechanistic" and the "organic" in Soviet neurophysiology, as perhaps in the history of physiology in general.

  3. [Physiology in Relation to Anesthesia Practice: Preface and Comments].

    Science.gov (United States)

    Yamada, Yoshitsugu

    2016-05-01

    It has been long recognized that anesthesia practice is profoundly based in physiology. With the advance of the technology of imaging, measurement and information, a serious gap has emerged between anesthesia mainly handling gross systemic parameters and molecular physiology. One of the main reasons is the lack of establishment of integration approach. This special series of reviews deals with systems physiology covering respiratory, cardiovascular, and nervous systems. It also includes metabolism, and fluid, acid-base, and electrolyte balance. Each review focuses on several physiological concepts in each area, explaining current understanding and limits of the concepts based on the new findings. They reaffirm the importance of applying physiological inference in anesthesia practice and underscore the needs of advancement of systems physiology.

  4. Automatic physiological waveform processing for FMRI noise correction and analysis.

    Directory of Open Access Journals (Sweden)

    Daniel J Kelley

    Full Text Available Functional MRI resting state and connectivity studies of brain focus on neural fluctuations at low frequencies which share power with physiological fluctuations originating from lung and heart. Due to the lack of automated software to process physiological signals collected at high magnetic fields, a gap exists in the processing pathway between the acquisition of physiological data and its use in fMRI software for both physiological noise correction and functional analyses of brain activation and connectivity. To fill this gap, we developed an open source, physiological signal processing program, called PhysioNoise, in the python language. We tested its automated processing algorithms and dynamic signal visualization on resting monkey cardiac and respiratory waveforms. PhysioNoise consistently identifies physiological fluctuations for fMRI noise correction and also generates covariates for subsequent analyses of brain activation and connectivity.

  5. Biomedical Signals and Sensors I Linking Physiological Phenomena and Biosignals

    CERN Document Server

    Kaniusas, Eugenijus

    2012-01-01

    This two-volume set focuses on the interface between physiologic mechanisms and diagnostic human engineering. Today numerous biomedical sensors are commonplace in clinical practice. The registered biosignals reflect mostly vital physiologic phenomena. In order to adequately apply biomedical sensors and reasonably interpret the corresponding biosignals, a proper understanding of the involved physiologic phenomena, their influence on the registered biosignals, and the technology behind the sensors is necessary. The first volume is devoted to the interface between physiologic mechanisms and arising biosignals, whereas the second volume is focussed on the interface between biosignals and biomedical sensors. The physiologic mechanisms behind the biosignals are described from the basic cellular level up to their advanced mutual coordination level during sleep. The arising biosignals are discussed within the scope of vital physiologic phenomena to foster their understanding and comprehensive analysis.

  6. Physiological regulatory networks: ecological roles and evolutionary constraints.

    Science.gov (United States)

    Cohen, Alan A; Martin, Lynn B; Wingfield, John C; McWilliams, Scott R; Dunne, Jennifer A

    2012-08-01

    Ecological and evolutionary physiology has traditionally focused on one aspect of physiology at a time. Here, we discuss the implications of considering physiological regulatory networks (PRNs) as integrated wholes, a perspective that reveals novel roles for physiology in organismal ecology and evolution. For example, evolutionary response to changes in resource abundance might be constrained by the role of dietary micronutrients in immune response regulation, given a particular pathogen environment. Because many physiological components impact more than one process, organismal homeostasis is maintained, individual fitness is determined and evolutionary change is constrained (or facilitated) by interactions within PRNs. We discuss how PRN structure and its system-level properties could determine both individual performance and patterns of physiological evolution.

  7. Validating the effectiveness of Clinically Oriented Physiology Teaching (COPT in undergraduate physiology curriculum

    Directory of Open Access Journals (Sweden)

    Ramnarayan Komattil

    2008-07-01

    Full Text Available Abstract Background It has been proved that basic science knowledge learned in the context of a clinical case is actually better comprehended and more easily applied by medical students than basic science knowledge learned in isolation. The present study intended to validate the effectiveness of Clinically Oriented Physiology Teaching (COPT in undergraduate medical curriculum at Melaka Manipal Medical College (Manipal Campus, Manipal, India. Methods COPT was a teaching strategy wherein, students were taught physiology using cases and critical thinking questions. Three batches of undergraduate medical students (n = 434 served as the experimental groups to whom COPT was incorporated in the third block (teaching unit of Physiology curriculum and one batch (n = 149 served as the control group to whom COPT was not incorporated. The experimental group of students were trained to answer clinically oriented questions whereas the control group of students were not trained. Both the group of students undertook a block exam which consisted of clinically oriented questions and recall questions, at the end of each block. Results Comparison of pre-COPT and post-COPT essay exam scores of experimental group of students revealed that the post-COPT scores were significantly higher compared to the pre-COPT scores. Comparison of post-COPT essay exam scores of the experimental group and control group of students revealed that the experimental group of students performed better compared to the control group. Feedback from the students indicated that they preferred COPT to didactic lectures. Conclusion The study supports the fact that assessment and teaching patterns should fall in line with each other as proved by the better performance of the experimental group of students compared to the control group. COPT was also found to be a useful adjunct to didactic lectures in teaching physiology.

  8. Validating the effectiveness of Clinically Oriented Physiology Teaching (COPT) in undergraduate physiology curriculum.

    Science.gov (United States)

    Abraham, Reem; Ramnarayan, Komattil; Kamath, Asha

    2008-07-24

    It has been proved that basic science knowledge learned in the context of a clinical case is actually better comprehended and more easily applied by medical students than basic science knowledge learned in isolation. The present study intended to validate the effectiveness of Clinically Oriented Physiology Teaching (COPT) in undergraduate medical curriculum at Melaka Manipal Medical College (Manipal Campus), Manipal, India. COPT was a teaching strategy wherein, students were taught physiology using cases and critical thinking questions. Three batches of undergraduate medical students (n = 434) served as the experimental groups to whom COPT was incorporated in the third block (teaching unit) of Physiology curriculum and one batch (n = 149) served as the control group to whom COPT was not incorporated. The experimental group of students were trained to answer clinically oriented questions whereas the control group of students were not trained. Both the group of students undertook a block exam which consisted of clinically oriented questions and recall questions, at the end of each block. Comparison of pre-COPT and post-COPT essay exam scores of experimental group of students revealed that the post-COPT scores were significantly higher compared to the pre-COPT scores. Comparison of post-COPT essay exam scores of the experimental group and control group of students revealed that the experimental group of students performed better compared to the control group. Feedback from the students indicated that they preferred COPT to didactic lectures. The study supports the fact that assessment and teaching patterns should fall in line with each other as proved by the better performance of the experimental group of students compared to the control group. COPT was also found to be a useful adjunct to didactic lectures in teaching physiology.

  9. From physiological psychology to psychological physiology: Postnonclassical approach to ethnocultural phenomena.

    Directory of Open Access Journals (Sweden)

    Asmolov, A.G.

    2015-07-01

    Full Text Available In modern science, along with the “classic” and “non-classical” approach to solving fundamental and applied problems, there is an actively developing “postnonclassical” research paradigm. This renovation of general scientific methodology has been accompanied by the emergence of new experimental technologies and new scientific research directions based on them. “Social psychophysiology” is one such direction. It is formed within the frame of postnonclassical methodology at the intersection of neuroscience and psychology. This work is devoted to the analytical review of the methods, achievements and prospects of contemporary social neuroscience and social psychophysiology studying brain structures that are specifically related to the implementation of social forms of behavior and intercultural communication. Physiological studies of brain activity during social interaction processes, which are simulated using virtual reality environments, are analyzed, and the physiological approach to the study of the brain mechanisms associated with social perception, social cognition and social behavior is used. Along with the analysis of psychophysiological studies of the mechanisms of social perception and social cognition, we discuss the theories of “Brain Reading” and “Theory of Mind” and the underlying data concerning “Gnostic neurons recognition of persons and recognition of emotional facial expressions”, “mirror neurons”, “emotional resonance” and “cognitive resonance”. Particular emphasis is placed on the discussion of a fundamentally new trend in the study of the relationship between the brain and culture (i.e., “cultural neuroscience”. Related to this connection, the following topics are raised: physiological mechanisms protecting the “individual distance” in communication between members of a personified community, psychophysiological approaches to the study of cross-cultural differences, physiological

  10. Comparative approaches to the study of physiology: Drosophila as a physiological tool

    OpenAIRE

    Neckameyer, Wendi S.; Argue, Kathryn J.

    2012-01-01

    Numerous studies have detailed the extensive conservation of developmental signaling pathways between the model system, Drosophila melanogaster, and mammalian models, but researchers have also profited from the unique and highly tractable genetic tools available in this system to address critical questions in physiology. In this review, we have described contributions that Drosophila researchers have made to mathematical dynamics of pattern formation, cardiac pathologies, the way in which pai...

  11. Human physiologically based pharmacokinetic model for propofol

    Directory of Open Access Journals (Sweden)

    Schnider Thomas W

    2005-04-01

    Full Text Available Abstract Background Propofol is widely used for both short-term anesthesia and long-term sedation. It has unusual pharmacokinetics because of its high lipid solubility. The standard approach to describing the pharmacokinetics is by a multi-compartmental model. This paper presents the first detailed human physiologically based pharmacokinetic (PBPK model for propofol. Methods PKQuest, a freely distributed software routine http://www.pkquest.com, was used for all the calculations. The "standard human" PBPK parameters developed in previous applications is used. It is assumed that the blood and tissue binding is determined by simple partition into the tissue lipid, which is characterized by two previously determined set of parameters: 1 the value of the propofol oil/water partition coefficient; 2 the lipid fraction in the blood and tissues. The model was fit to the individual experimental data of Schnider et. al., Anesthesiology, 1998; 88:1170 in which an initial bolus dose was followed 60 minutes later by a one hour constant infusion. Results The PBPK model provides a good description of the experimental data over a large range of input dosage, subject age and fat fraction. Only one adjustable parameter (the liver clearance is required to describe the constant infusion phase for each individual subject. In order to fit the bolus injection phase, for 10 or the 24 subjects it was necessary to assume that a fraction of the bolus dose was sequestered and then slowly released from the lungs (characterized by two additional parameters. The average weighted residual error (WRE of the PBPK model fit to the both the bolus and infusion phases was 15%; similar to the WRE for just the constant infusion phase obtained by Schnider et. al. using a 6-parameter NONMEM compartmental model. Conclusion A PBPK model using standard human parameters and a simple description of tissue binding provides a good description of human propofol kinetics. The major advantage of a

  12. Thyroid in pregnancy: From physiology to screening.

    Science.gov (United States)

    Springer, Drahomira; Jiskra, Jan; Limanova, Zdenka; Zima, Tomas; Potlukova, Eliska

    2017-03-01

    Thyroid hormones are crucial for the growth and maturation of many target tissues, especially the brain and skeleton. During critical periods in the first trimester of pregnancy, maternal thyroxine is essential for fetal development as it supplies thyroid hormone-dependent tissues. The ontogeny of mature thyroid function involves organogenesis, and maturation of the hypothalamus, pituitary and the thyroid gland; and it is almost complete by the 12th-14th gestational week. In case of maternal hypothyroidism, substitution with levothyroxine must be started in early pregnancy. After the 14th gestational week, fetal brain development may already be irreversibly affected by lack of thyroid hormones. The prevalence of manifest hypothyroidism in pregnancy is about 0.3-0.5%. The prevalence of subclinical hypothyroidism varies between 4 and 17%, strongly depending on the definition of the upper TSH cutoff limit. Hyperthyroidism occurs in 0.1-1% of all pregnancies. Positivity for antibodies against thyroid peroxidase (TPOAb) is common in women of childbearing age with an incidence rate of 5.1-12.4%. TPOAb-positivity may be regarded as a manifestation of a general autoimmune state which may alter the fertilization and implantation processes or cause early missed abortions. Women positive for TPOAb are at a significant risk of developing hypothyroidism during pregnancy and postpartum. Laboratory diagnosis of thyroid dysfunction during pregnancy is based upon serum TSH concentration. TSH in pregnancy is physiologically lower than the non-pregnant population. Results of multiple international studies point toward creation of trimester-specific reference intervals for TSH in pregnancy. Screening for hypothyroidism in pregnancy is controversial and its implementation varies from country to country. Currently, the case-finding approach of screening high-risk women is preferred in most countries to universal screening. However, numerous studies have shown that one-third to one

  13. Biodegradation of 3-Nitrotyrosine by Burkholderia sp. Strain JS165 and Variovorax paradoxus JS171

    Science.gov (United States)

    2006-02-01

    and B. Minambres. 2004. The homogentisate pathway: a central catabolic pathway involved in the degradation of L- phenylalanine , L-tyrosine, and 3...acetate-3- hydroxylase . A two-protein component enzyme. J. Biol. Chem. 267:25848–25855. 4. Bruhn, C., H. Lenke, and H.-J. Knackmuss. 1987. Nitrosubstituted

  14. Hydration Effects on Human Physiology and Exercise-Heat Performance

    Science.gov (United States)

    1989-11-01

    AD REPORT NO T7-90 HYDRATION EFFECTS :N HUMAN PHYSIOLOGY AND EXERCISE-HEA PERFORMANCE Co U S ARMY RESEARCH INSTITUTE N OF I ENVIRONMENTAL MEDICINE...effects on human physiology and exercise.-heat performance 12 PERSONAL AUTHOR(S) Michael N. Sawka, Andrew J. Young. William A. Latzka, P. Darrell...acknowledge Ms. Patricia DeMusis for preparing the manuscript. AD Report No. HYDRATION EFFECTS ON HUMAN PHYSIOLOGY AND EXERCISE-HEAT PERFORMANCE by Michael N

  15. Evolutionary Medicine: The Ongoing Evolution of Human Physiology and Metabolism.

    Science.gov (United States)

    Rühli, Frank; van Schaik, Katherine; Henneberg, Maciej

    2016-11-01

    The field of evolutionary medicine uses evolutionary principles to understand changes in human anatomy and physiology that have occurred over time in response to environmental changes. Through this evolutionary-based approach, we can understand disease as a consequence of anatomical and physiological "trade-offs" that develop to facilitate survival and reproduction. We demonstrate how diachronic study of human anatomy and physiology is fundamental for an increased understanding of human health and disease.

  16. Physiological Employment Standards III: physiological challenges and consequences encountered during international military deployments.

    Science.gov (United States)

    Nindl, Bradley C; Castellani, John W; Warr, Bradley J; Sharp, Marilyn A; Henning, Paul C; Spiering, Barry A; Scofield, Dennis E

    2013-11-01

    Modern international military deployments in austere environments (i.e., Iraq and Afghanistan) place considerable physiological demands on soldiers. Significant physiological challenges exist: maintenance of physical fitness and body composition, rigors of external load carriage, environmental extremes (heat, cold, and altitude), medical illnesses, musculoskeletal injuries, traumatic brain injuries, post-traumatic stress disorder, and environmental exposure hazards (i.e., burn pits, vehicle exhaust, etc.). To date there is very little published research and no comprehensive reviews on the physiological effects of deployments. The purpose of this paper is to overview what is currently known from the literature related mainly to current military conflicts with regard to the challenges and consequences from deployments. Summary findings include: (1) aerobic capacity declines while muscle strength, power and muscular endurance appear to be maintained, (2) load carriage continues to tax the physical capacities of the Soldier, (3) musculoskeletal injuries comprise the highest proportion of all injury categories, (4) environmental insults occur from both terrestrial extremes and pollutant exposure, and (5) post-deployment concerns linger for traumatic brain injury and post-traumatic stress disorder. A full understanding of these responses will assist in identifying the most effective risk mitigation strategies to ensure deployment readiness and to assist in establishment of military employment standards.

  17. Physiological roles of taurine in heart and muscle

    National Research Council Canada - National Science Library

    Schaffer, Stephen W; Jong, Chian Ju; Ramila, K C; Azuma, Junichi

    2010-01-01

    .... The present review discusses several physiological functions of taurine. First, the observation that taurine depletion leads to the development of a cardiomyopathy indicates a role for taurine...

  18. American neurophysiology and two nineteenth-century American Physiological Societies.

    Science.gov (United States)

    Lazar, J Wayne

    2017-01-01

    This article contrasts two American Physiological Societies, one founded near the beginning of the nineteenth century in 1837 and the other founded near its end in 1887. The contrast allows a perspective on how much budding neuroscience had developed during the nineteenth century in America. The contrast also emphasizes the complicated structure needed in both medicine and physiology to allow neurophysiology to flourish. The objectives of the American Physiological Society of 1887 were (and are) to promote physiological research and to codify physiology as a discipline. These would be accomplished by making physiology much more inclusive than traditionally accepted by raising research standards, by giving prestige to its members, by providing members a source of professional interchange, by protecting its members from antivivisectionists, and by promoting physiology as fundamental to medicine. The quantity of neuroscientific experiments by its members was striking. The main organizers of the society were Silas Weir Mitchell, John Call Dalton, Henry Pickering Bowditch, and Henry Newell Martin. The objective of the American Physiological Society of 1837 was to disperse knowledge of the "laws of life" and to promote human health and longevity. The primary organizers were William Andrus Alcott and Sylvester Graham with the encouragement of John Benson. Its technique was to use physiological information, not create it as was the case in 1887. Its object was to disseminate the word that healthy eating will improve the quality of life.

  19. Tests for evaluating the physiological quality of pitaya seeds

    National Research Council Canada - National Science Library

    Thiago Alberto Ortiz; Aline Moritz; Lúcia Sadayo Assari Takahashi; Mariana Ragassi Urbano

    2015-01-01

    .... Thus, this study aimed to develop methodologies for conducting tests of germination, accelerated aging, and electrical conductivity for the evaluation of the physiological quality of pitaya seeds...

  20. Physicochemical and physiological basis of dichromatic colour

    Science.gov (United States)

    Kreft, Samo; Kreft, Marko

    2007-11-01

    Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

  1. Smolt physiology and endocrinology: Chapter 5

    Science.gov (United States)

    McCormick, Stephen D.; McCormick, Stephen D.; Farrell, Anthony Peter; Brauner, Colin J.

    2012-01-01

    The parr-smolt transformation of anadromous salmonids is a suite of behavioral, morphological, and physiological changes that are preparatory for downstream migration and seawater entry. The timing of smolt development varies among species, occurring soon after hatching in pink and chum salmon and after one to several years in Atlantic salmon. In many species the transformation is size dependent and occurs in spring, mediated through photoperiod and temperature cues. Smolt development is stimulated by several hormones including growth hormone, insulin-like growth factor-1, cortisol, and thyroid hormones, whereas prolactin is generally inhibitory. Increased salinity tolerance is one of the most important and tractable changes, and is caused by alteration in the function of the major osmoregulatory organs, the gill, gut, and kidney. Increased abundance of specific ion transporters (Na+/K+-ATPase, Na+/K+/Cl− cotransporter and apical Cl− channel) in gill ionocytes results in increased salt secretory capacity, increased growth and swimming performance in seawater, and higher marine survival.

  2. Early history of high-altitude physiology.

    Science.gov (United States)

    West, John B

    2016-02-01

    High-altitude physiology can be said to have begun in 1644 when Torricelli described the first mercury barometer and wrote the immortal words "We live submerged at the bottom of an ocean of the element air." Interestingly, the notion of atmospheric pressure had eluded his teacher, the great Galileo. Blaise Pascal was responsible for describing the fall in pressure with increasing altitude, and Otto von Guericke gave a dramatic demonstration of the enormous force that could be developed by atmospheric pressure. Robert Boyle learned of Guericke's experiment and, with Robert Hooke, constructed the first air pump that allowed small animals to be exposed to a low pressure. Hooke also constructed a small low-pressure chamber and exposed himself to a simulated altitude of about 2400 meters. With the advent of ballooning, humans were rapidly exposed to very low pressures, sometimes with tragic results. For example, the French balloon, Zénith, rose to over 8000 m, and two of the three aeronauts succumbed to the hypoxia. Paul Bert was the first person to clearly state that the deleterious effects of high altitude were caused by the low partial pressure of oxygen (PO2), and later research was accelerated by high-altitude stations and expeditions to high altitude.

  3. Bile acids: Chemistry, physiology, and pathophysiology

    Institute of Scientific and Technical Information of China (English)

    Maria J Monte; Jose JG Marin; Alvaro Antelo; Jose Vazquez-Tato

    2009-01-01

    The family of bile acids includes a group of molecular species of acidic steroids with very peculiar physicalchemical and biological characteristics. They are synthesized by the liver from cholesterol through several complementary pathways that are controlled by mechanisms involving fine-tuning by the levels of certain bile acid species. Although their bestknown role is their participation in the digestion and absorption of fat, they also play an important role in several other physiological processes. Thus, genetic abnormalities accounting for alterations in their synthesis, biotransformation and/or transport may result in severe alterations, even leading to lethal situations for which the sole therapeutic option may be liver transplantation. Moreover, the increased levels of bile acids reached during cholestatic liver diseases are known to induce oxidative stress and apoptosis, resulting in damage to the liver parenchyma and, ventually, extrahepatic tissues. When this occurs during pregnancy, the outcome of gestation may be challenged. In contrast, the physical-chemical and biological properties of these compounds have been used as the bases for the development of drugs and as pharmaceutical tools for the delivery of active agents.

  4. The quest for physiologic insulin replacement.

    Science.gov (United States)

    Owens, David R

    2004-11-01

    Historically, the objective of insulin replacement has been to simulate the 2 major components of insulin secretion in individuals without diabetes mellitus: the low-level basal secretion during the night and periods of fasting, and the prandial secretion in response to food intake. The variable pharmacokinetic and pharmacodynamic characteristics of conventional insulin preparations have made mimicking these physiologic profiles virtually impossible. Balancing the effects of diet, exercise, and the numerous factors contributing to intra- and inter-individual variations in insulin absorption and action, such as type, site of injection, and dosage of insulin, while avoiding the very serious side effect of hypoglycemia in seeking normoglycemia, presents a further challenge. Recently, these limitations have been addressed by recombinant DNA-mediated development of insulin analogues, such as rapid-acting insulin lispro, aspart and glulisine, and the long-acting insulin preparations, insulin glargine and detemir. The molecular structures of these analogues have produced time-action profiles that better approach prandial and basal insulin secretion, thus allowing for easier, safer, and more flexible treatment regimens.

  5. A dynamic model of human physiology

    Science.gov (United States)

    Green, Melissa; Kaplan, Carolyn; Oran, Elaine; Boris, Jay

    2010-11-01

    To study the systems-level transport in the human body, we develop the Computational Man (CMAN): a set of one-dimensional unsteady elastic flow simulations created to model a variety of coupled physiological systems including the circulatory, respiratory, excretory, and lymphatic systems. The model systems are collapsed from three spatial dimensions and time to one spatial dimension and time by assuming axisymmetric vessel geometry and a parabolic velocity profile across the cylindrical vessels. To model the actions of a beating heart or expanding lungs, the flow is driven by user-defined changes to the equilibrium areas of the elastic vessels. The equations are then iteratively solved for pressure, area, and average velocity. The model is augmented with valves and contractions to resemble the biological structure of the different systems. CMAN will be used to track material transport throughout the human body for diagnostic and predictive purposes. Parameters will be adjustable to match those of individual patients. Validation of CMAN has used both higher-dimensional simulations of similar geometries and benchmark measurement from medical literature.

  6. Leptin in human physiology and therapeutics.

    Science.gov (United States)

    Dardeno, Tina A; Chou, Sharon H; Moon, Hyun-Seuk; Chamberland, John P; Fiorenza, Christina G; Mantzoros, Christos S

    2010-07-01

    Leptin regulates energy homeostasis and reproductive, neuroendocrine, immune, and metabolic functions. In this review, we describe the role of leptin in human physiology and review evidence from recent "proof of concept" clinical trials using recombinant human leptin in subjects with congenital leptin deficiency, hypoleptinemia associated with energy-deficient states, and hyperleptinemia associated with garden-variety obesity. Since most obese individuals are largely leptin-tolerant or -resistant, therapeutic uses of leptin are currently limited to patients with complete or partial leptin deficiency, including hypothalamic amenorrhea and lipoatrophy. Leptin administration in these energy-deficient states may help restore associated neuroendocrine, metabolic, and immune function and bone metabolism. Leptin treatment is currently available for individuals with congenital leptin deficiency and congenital lipoatrophy. The long-term efficacy and safety of leptin treatment in hypothalamic amenorrhea and acquired lipoatrophy are currently under investigation. Whether combination therapy with leptin and potential leptin sensitizers will prove effective in the treatment of garden-variety obesity and whether leptin may have a role in weight loss maintenance is being greatly anticipated.

  7. Multidrug resistance: Physiological principles and nanomedical solutions.

    Science.gov (United States)

    Kunjachan, Sijumon; Rychlik, Błażej; Storm, Gert; Kiessling, Fabian; Lammers, Twan

    2013-11-01

    Multidrug resistance (MDR) is a pathophysiological phenomenon employed by cancer cells which limits the prolonged and effective use of chemotherapeutic agents. MDR is primarily based on the over-expression of drug efflux pumps in the cellular membrane. Prominent examples of such efflux pumps, which belong to the ATP-binding cassette (ABC) superfamily of proteins, are Pgp (P-glycoprotein) and MRP (multidrug resistance-associated protein), nowadays officially known as ABCB1 and ABCC1. Over the years, several strategies have been evaluated to overcome MDR, based not only on the use of low-molecular-weight MDR modulators, but also on the implementation of 1-100(0) nm-sized drug delivery systems. In the present manuscript, after introducing the most important physiological principles of MDR, we summarize prototypic nanomedical strategies to overcome multidrug resistance, including the use of carrier materials with intrinsic anti-MDR properties, the use of nanomedicines to modify the mode of cellular uptake, and the co-formulation of chemotherapeutic drugs together with low- and high-molecular-weight MDR inhibitors within a single drug delivery system. While certain challenges still need to be overcome before such constructs and concepts can be widely applied in the clinic, the insights obtained and the progress made strongly suggest that nanomedicine formulations hold significant potential for improving the treatment of multidrug-resistant malignancies.

  8. Physiological and environmental control of yeast prions.

    Science.gov (United States)

    Chernova, Tatiana A; Wilkinson, Keith D; Chernoff, Yury O

    2014-03-01

    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.

  9. Anhydrobiosis in bacteria: From physiology to applications

    Indian Academy of Sciences (India)

    Armando Hernández García

    2011-12-01

    Anhydrobiosis is a phenomenon related to the partial or total desiccation of living organisms, keeping their vital functions after rehydration. The desiccated state in prokaryotes has been widely studied, mainly due to the broad spectrum of the anhydrobiosis applications. In this review, we present the basic theoretical concepts related to anhydrobiosis, focusing on bacterial species. An update about desiccation tolerance in bacteria is given; and the general mechanisms of desiccation tolerance and desiccation damage are described. In addition, we show how the study of anhydrobiosis in prokaryotes has established the theoretical and practical basis for the development of the drying technologies. With regard to the desiccation tolerance in bacteria, although many mechanisms remain undiscovered at the molecular level, important research about the physiology of the anhydrobiotic state and its applications has been performed, and here we provide the most recent information about this subject. On the other hand, the most widely used drying technologies and their particular applications in several fields are described (e.g. medicine, agriculture and food industry). Finally, topics on the stability of desiccated bacterial cells are treated, concluding with the necessity of focusing the research on the mathematical modelling of the desiccated state in bacteria.

  10. Physiological Responses to Thermal Stress and Exercise

    Science.gov (United States)

    Iyota, Hiroyuki; Ohya, Akira; Yamagata, Junko; Suzuki, Takashi; Miyagawa, Toshiaki; Kawabata, Takashi

    The simple and noninvasive measuring methods of bioinstrumentation in humans is required for optimization of air conditioning and management of thermal environments, taking into consideration the individual specificity of the human body as well as the stress conditions affecting each. Changes in human blood circulation were induced with environmental factors such as heat, cold, exercise, mental stress, and so on. In this study, the physiological responses of human body to heat stress and exercise were investigated in the initial phase of the developmental research. We measured the body core and skin temperatures, skin blood flow, and pulse wave as the indices of the adaptation of the cardiovascular system. A laser Doppler skin blood flowmetry using an optical-sensor with a small portable data logger was employed for the measurement. These results reveal the heat-stress and exercise-induced circulatory responses, which are under the control of the sympathetic nerve system. Furthermore, it was suggested that the activity of the sympathetic nervous system could be evaluated from the signals of the pulse wave included in the signals derived from skin blood flow by means of heart rate variability assessments and detecting peak heights of velocity-plethysmogram.

  11. Fluoxetine: clinical pharmacology and physiologic disposition

    Energy Technology Data Exchange (ETDEWEB)

    Lemberger, L.; Bergstrom, R.F.; Wolen, R.L.; Farid, N.A.; Enas, G.G.; Aronoff, G.R.

    1985-03-01

    Fluoxetine (30 mg), administered for 7 days to normal volunteers, produced a 66% inhibition of tritiated serotonin uptake into platelets. Plasma concentrations of fluoxetine correlated positively with inhibition of serotonin uptake. Fluoxetine is well absorbed after oral administration in both the fed and fasted states and demonstrates dose proportionality. Fluoxetine disappears from plasma with a half-life of 1-3 days; its metabolite norfluoxetine has a plasma half-life of 7-15 days. After administration of /sup 14/C-fluoxetine, approximately 65% of the administered dose of radioactivity is recovered in urine and about 15% in feces. Fluoxetine, given as a single dose or in multiple doses over 8 days, did not produce significant effects on the plasma disappearance of warfarin, diazepam, tolbutamide, or chlorothiazide. Coadministration of fluoxetine and ethanol did not result in an increase from control values in the blood ethanol levels, nor did it produce significant changes in physiologic, psychometric, or psychomotor activity. Pharmacokinetics of fluoxetine in the elderly and normal volunteers appear to be similar. In addition, pharmacokinetic analyses in patients with varying degrees of renal impairment did not show significant differences from healthy subjects.

  12. [Adrenomedullin in the kidney: physiology and pathophysiology].

    Science.gov (United States)

    Sogbe-Díaz, Miguel Eduardo; Díaz-López, Emilia Elena

    2016-03-01

    Adrenomedullin (AM) is a potent vasodilatory 52-aminoacid peptide hormone, ubiquitous with multiple physiological effects which contribute to homeostatic responses. Significantly, it is distributed in the adrenal gland, lung, cardiovascular and renal system. The biological effects of AM are directly mediated by specific receptors as heterodimers composed of the calcitonin-receptor-like receptor (CLR) and one of two receptor activity modifying proteins (RAMP2 or RAMP3). The CLR/RAMP2 (AM1 receptor) is more highly AM-specific than The CLR/RAMP3 (AM2 receptor). Plasma levels of AM are elevated proportionately to the increase in blood pressure and degree of renal damage in patients with hypertension; likewise, these levels are correlated with the degree ofheart and arterial hypertrophy. AM has renal vasodilatory, natriuretic and diuretic actions; increased glomerular filtration rate and renal blood flow. AM inhibits proliferation and reactive oxygen species generation in mesangial cells; also inhibits aldosterone secretion in the zona glomerulosa and endothelin-1 in vascular smooth muscle cells. Therefore, it is proposed as a new marker in various diseases, especially chronic renal failure. This disease presents compensatory hypertrophy of the glomeruli and mesangial proliferation, administration of AM reduces the levels of proteinuria, suggesting that AM has an important modulator role in blood pressure and could be a therapeutic option for chronic renal failure.

  13. The Virtual Physiological Human ToolKit.

    Science.gov (United States)

    Cooper, Jonathan; Cervenansky, Frederic; De Fabritiis, Gianni; Fenner, John; Friboulet, Denis; Giorgino, Toni; Manos, Steven; Martelli, Yves; Villà-Freixa, Jordi; Zasada, Stefan; Lloyd, Sharon; McCormack, Keith; Coveney, Peter V

    2010-08-28

    The Virtual Physiological Human (VPH) is a major European e-Science initiative intended to support the development of patient-specific computer models and their application in personalized and predictive healthcare. The VPH Network of Excellence (VPH-NoE) project is tasked with facilitating interaction between the various VPH projects and addressing issues of common concern. A key deliverable is the 'VPH ToolKit'--a collection of tools, methodologies and services to support and enable VPH research, integrating and extending existing work across Europe towards greater interoperability and sustainability. Owing to the diverse nature of the field, a single monolithic 'toolkit' is incapable of addressing the needs of the VPH. Rather, the VPH ToolKit should be considered more as a 'toolbox' of relevant technologies, interacting around a common set of standards. The latter apply to the information used by tools, including any data and the VPH models themselves, and also to the naming and categorizing of entities and concepts involved. Furthermore, the technologies and methodologies available need to be widely disseminated, and relevant tools and services easily found by researchers. The VPH-NoE has thus created an online resource for the VPH community to meet this need. It consists of a database of tools, methods and services for VPH research, with a Web front-end. This has facilities for searching the database, for adding or updating entries, and for providing user feedback on entries. Anyone is welcome to contribute.

  14. Eccentric Exercise: Physiological Characteristics and Acute Responses.

    Science.gov (United States)

    Douglas, Jamie; Pearson, Simon; Ross, Angus; McGuigan, Mike

    2017-04-01

    An eccentric contraction involves the active lengthening of muscle under an external load. The molecular and neural mechanisms underpinning eccentric contractions differ from those of concentric and isometric contractions and remain less understood. A number of molecular theories have been put forth to explain the unexplained observations during eccentric contractions that deviate from the predictions of the established theories of muscle contraction. Postulated mechanisms include a strain-induced modulation of actin-myosin interactions at the level of the cross-bridge, the activation of the structural protein titin, and the winding of titin on actin. Accordingly, neural strategies controlling eccentric contractions also differ with a greater, and possibly distinct, cortical activation observed despite an apparently lower activation at the level of the motor unit. The characteristics of eccentric contractions are associated with several acute physiological responses to eccentrically-emphasised exercise. Differences in neuromuscular, metabolic, hormonal and anabolic signalling responses during, and following, an eccentric exercise bout have frequently been observed in comparison to concentric exercise. Subsequently, the high levels of muscular strain with such exercise can induce muscle damage which is rarely observed with other contraction types. The net result of these eccentric contraction characteristics and responses appears to be a novel adaptive signal within the neuromuscular system.

  15. A population model of integrative cardiovascular physiology.

    Science.gov (United States)

    Pruett, William A; Husband, Leland D; Husband, Graham; Dakhlalla, Muhammad; Bellamy, Kyle; Coleman, Thomas G; Hester, Robert L

    2013-01-01

    We present a small integrative model of human cardiovascular physiology. The model is population-based; rather than using best fit parameter values, we used a variant of the Metropolis algorithm to produce distributions for the parameters most associated with model sensitivity. The population is built by sampling from these distributions to create the model coefficients. The resulting models were then subjected to a hemorrhage. The population was separated into those that lost less than 15 mmHg arterial pressure (compensators), and those that lost more (decompensators). The populations were parametrically analyzed to determine baseline conditions correlating with compensation and decompensation. Analysis included single variable correlation, graphical time series analysis, and support vector machine (SVM) classification. Most variables were seen to correlate with propensity for circulatory collapse, but not sufficiently to effect reasonable classification by any single variable. Time series analysis indicated a single significant measure, the stressed blood volume, as predicting collapse in situ, but measurement of this quantity is clinically impossible. SVM uncovered a collection of variables and parameters that, when taken together, provided useful rubrics for classification. Due to the probabilistic origins of the method, multiple classifications were attempted, resulting in an average of 3.5 variables necessary to construct classification. The most common variables used were systemic compliance, baseline baroreceptor signal strength and total peripheral resistance, providing predictive ability exceeding 90%. The methods presented are suitable for use in any deterministic mathematical model.

  16. A population model of integrative cardiovascular physiology.

    Directory of Open Access Journals (Sweden)

    William A Pruett

    Full Text Available We present a small integrative model of human cardiovascular physiology. The model is population-based; rather than using best fit parameter values, we used a variant of the Metropolis algorithm to produce distributions for the parameters most associated with model sensitivity. The population is built by sampling from these distributions to create the model coefficients. The resulting models were then subjected to a hemorrhage. The population was separated into those that lost less than 15 mmHg arterial pressure (compensators, and those that lost more (decompensators. The populations were parametrically analyzed to determine baseline conditions correlating with compensation and decompensation. Analysis included single variable correlation, graphical time series analysis, and support vector machine (SVM classification. Most variables were seen to correlate with propensity for circulatory collapse, but not sufficiently to effect reasonable classification by any single variable. Time series analysis indicated a single significant measure, the stressed blood volume, as predicting collapse in situ, but measurement of this quantity is clinically impossible. SVM uncovered a collection of variables and parameters that, when taken together, provided useful rubrics for classification. Due to the probabilistic origins of the method, multiple classifications were attempted, resulting in an average of 3.5 variables necessary to construct classification. The most common variables used were systemic compliance, baseline baroreceptor signal strength and total peripheral resistance, providing predictive ability exceeding 90%. The methods presented are suitable for use in any deterministic mathematical model.

  17. SIRT3 in cardiac physiology and disease

    Directory of Open Access Journals (Sweden)

    Christoph Koentges

    2016-10-01

    Full Text Available Functional defects in mitochondrial biology causally contribute to various human diseases, including cardiovascular disease. Impairment in oxidative phosphorylation, mitochondrial oxidative stress and increased opening of the mitochondrial permeability transition pore add to the underlying mechanisms of heart failure or myocardial ischemia reperfusion (IR injury. Recent evidence demonstrated that the mitochondrial NAD+-dependent deacetylase sirtuin 3 (SIRT3 may regulate these mitochondrial functions by reversible protein lysine deacetylation. Loss of function studies demonstrated a role of impaired SIRT3 activity in the pathogenesis of myocardial IR injury as well as in the development of cardiac hypertrophy and the transition into heart failure. Gain of function studies and treatment approaches increasing mitochondrial NAD+ availability that ameliorate these cardiac pathologies have led to the proposal that activation of SIRT3 may represent a promising therapeutic strategy to improve mitochondrial derangements in various cardiac pathologies. In the current review, we will present and discuss the available literature on the role of SIRT3 in cardiac physiology and disease.

  18. Physiologically Based Pharmacokinetic (PBPK) Modeling of ...

    Science.gov (United States)

    Background: Quantitative estimation of toxicokinetic variability in the human population is a persistent challenge in risk assessment of environmental chemicals. Traditionally, inter-individual differences in the population are accounted for by default assumptions or, in rare cases, are based on human toxicokinetic data.Objectives: To evaluate the utility of genetically diverse mouse strains for estimating toxicokinetic population variability for risk assessment, using trichloroethylene (TCE) metabolism as a case study. Methods: We used data on oxidative and glutathione conjugation metabolism of TCE in 16 inbred and one hybrid mouse strains to calibrate and extend existing physiologically-based pharmacokinetic (PBPK) models. We added one-compartment models for glutathione metabolites and a two-compartment model for dichloroacetic acid (DCA). A Bayesian population analysis of inter-strain variability was used to quantify variability in TCE metabolism. Results: Concentration-time profiles for TCE metabolism to oxidative and glutathione conjugation metabolites varied across strains. Median predictions for the metabolic flux through oxidation was less variable (5-fold range) than that through glutathione conjugation (10-fold range). For oxidative metabolites, median predictions of trichloroacetic acid production was less variable (2-fold range) than DCA production (5-fold range), although uncertainty bounds for DCA exceeded the predicted variability. Conclusions:

  19. Diabetes mellitus, part 1: physiology and complications.

    Science.gov (United States)

    Nair, Muralitharan

    In part 1 of this 2-part article the author discusses the physiology and complications of diabetes mellitus (DM), a chronic and progressive disorder which affects all ages of the population. The number of people diagnosed with diabetes is approximately 1.8 million and an estimated further 1 million are undiagnosed (Department of Health, 2005). In the UK, 1-2% of the population have diabetes and among school children this is approximately 2 in 1000 (Watkins, 1996). There are two main types of diabetes--type 1 and type 2 (Porth, 2005). The aetiology of DM is unknown; however, genetic and environmental factors have been linked to its development. Type 1 results from the loss of insulin production in the beta cells of the pancreas, and type 2 from a lack of serum insulin or poor uptake of glucose into the cells. Diabetes causes disease in many organs in the body, which may be life-threatening if untreated. Complications such as heart disease, vascular disease, renal failure and blindness (Roberts, 2005) have all been reported. The increased prevalence may be caused by factors such as environmental aspects, diet, an ageing population and low levels of physical exercise.

  20. Physiological and pathological implications of cholesterol.

    Science.gov (United States)

    Cortes, Victor A; Busso, Dolores; Maiz, Alberto; Arteaga, Antonio; Nervi, Flavio; Rigotti, Attilio

    2014-01-01

    Cholesterol has evolved to fulfill sophisticated biophysical, cell signaling and endocrine requirements of animal systems. At a cellular level, cholesterol is found in membranes, where it increases both bilayer stiffness and impermeability to water and ions. Furthermore, cholesterol is integrated into specialized lipid-protein membrane microdomains with critical topographical and signaling functions. At an organismal level, cholesterol is the precursor for all steroid hormones, including gluco- and mineralo-corticoids, sex hormones and vitamin D, all of which regulate carbohydrate, sodium, reproductive and bone homeostasis, respectively. This sterol is also the precursor for bile acids, which are important for intestinal absorption of dietary lipids as well as energy and glucose metabolic regulation. Importantly, complex mechanisms maintain cholesterol within physiological ranges and the disregulation of these mechanisms results in embryonic or adult diseases, caused by either excessive or reduced tissue cholesterol levels. The causative role of cholesterol in these diseases has been demonstrated by diverse genetic and pharmacologic animal models that are commented in this review.

  1. Metabolism, Physiology and Biotechnological Applications of Halobacteria

    Directory of Open Access Journals (Sweden)

    Oleg Mosin

    2015-06-01

    Full Text Available Halophiles (lat. “salt-loving” is the taxonomic group of extreme aerobic obligate Gram-negative microorganisms that live in conditions of high salinity – in the seas, salt lakes, saline soils etc. These microorganisms are known to reddish patina on products, preserved with using large quantities of salt (NaCl. Halophiles were isolated for the first time at the beginning of the XX century from the marine flora estuary mud, but their systematic study was started only at the end of the second decade of the XX century. The internal environment of the human body is not suitable for existence of halobacteria, since none of them are known to have pathogenic forms. Halobacteria have great practical potential for using in molecular bioelectronics and bio-nanotechnology due to their unique ability to convert the energy of sunlight into electrochemical energy of protons H+ due to the presence in their cells a special photo transforming retinal containing integral protein – bacteriorhodopsin, the mechanism of action of which has been currently studied in detail. This article describes the characteristics of the metabolism and physiology of halophilic bacteria, as well as a method of biosynthesis and preparation of bacteriorhodopsin from purple membranes of cells of the extreme photoorganotrophic halobacterium Halobacterium halobium.

  2. Endocrine FGFs: evolution, physiology, pathophysiology, and pharmacotherapy

    Directory of Open Access Journals (Sweden)

    Nobuyuki eItoh

    2015-09-01

    Full Text Available The human fibroblast growth factor (FGF family comprises 22 structurally related polypeptides that play crucial roles in neuronal functions, development, and metabolism. FGFs are classified as intracrine, paracrine, and endocrine FGFs based on their action mechanisms. Paracrine and endocrine FGFs are secreted signaling molecules by acting via cell-surface FGF receptors (FGFRs. Paracrine FGFs require heparan sulfate as a co-factor for FGFRs. In contrast, endocrine FGFs, comprising FGF19, FGF21, and FGF23, require α−Klotho or β−Klotho as a co-factor for FGFRs. Endocrine FGFs, which are specific to vertebrates, lost heparan sulfate-binding affinity and acquired a systemic signaling system with αKlotho or βKlotho during early vertebrate evolution. The phenotypes of endocrine FGF knockout mice indicate that they play roles in metabolism including bile acid, energy, and phosphate/active vitamin D metabolism. Accumulated evidence for the involvement of endocrine FGFs in human genetic and metabolic diseases also indicates their pathophysiological roles in metabolic diseases, potential risk factors for metabolic diseases, and useful biomarkers for metabolic diseases. The therapeutic utility of endocrine FGFs is currently being developed. These findings provide new insights into the physiological and pathophysiological roles of endocrine FGFs and potential diagnostic and therapeutic strategies for metabolic diseases.

  3. Assessment of acute physiological demand for soccer

    Directory of Open Access Journals (Sweden)

    Daniel Barbosa Coelho

    2013-09-01

    Full Text Available Soccer is a sport practiced worldwide, on all continents. It is considered an intermittent activity of high intensity and long duration, in which movements that require great strength and speed, such as jumps and sprints, result in high levels of muscle microtrauma, hampering athletes’ training and recovery. The present study aimed to evaluate the magnitude of changes in different markers of physiological demand resulting from a soccer match in healthy individuals. Ten healthy male physical education students participated in the study and were evaluated in two matches: the semi-final and final games of the college tournament at the federal university where they studied. Blood samples were collected from each volunteer pre- and post-match. Cortisol, IL-6 and CK concentrations were increased after the match (p < 0.05. Testosterone and alpha-actin concentrations did not change. Our results indicate that changes in some of the acute response markers evaluated in players before and after competitive soccer matches provide important information for planning training or recovery, as well as nutritional strategies for improving performance.

  4. Physiological demands of a simulated BMX competition.

    Science.gov (United States)

    Louis, J; Billaut, F; Bernad, T; Vettoretti, F; Hausswirth, C; Brisswalter, J

    2013-06-01

    The aim of this study was to investigate the physiological demands of Supercross BMX in elite athletes. Firstly athletes underwent an incremental cycling test to determine maximal oxygen uptake (VO2max) and power at ventilatory thresholds. In a second phase, athletes performed alone a simulated competition, consisting of 6 cycling races separated by 30 min of passive recovery on an actual BMX track. Oxygen uptake, blood lactate, anion gap and base excess (BE) were measured. Results indicated that a simulated BMX performed by elite athletes induces a high solicitation of both aerobic (mean peak VO2 (VO2peak): 94.3±1.2% VO2max) and anaerobic glycolysis (mean blood lactate: 14.5±4. 5 mmol x L(-1) during every race. Furthermore, the repetition of the 6 cycling races separated by 30 min of recovery led to a significant impairment of the acid-base balance from the third to the sixth race (mean decrease in BE: -18.8±7.5%, pBMX performance. These results suggest that both oxygen-dependent and -independent fuel substrate pathways are important determinants of BMX performance.

  5. Physiology responses of Rhesus monkeys to vibration

    Science.gov (United States)

    Hajebrahimi, Zahra; Ebrahimi, Mohammad; Alidoust, Leila; Arabian Hosseinabadi, Maedeh

    Vibration is one of the important environmental factors in space vehicles that it can induce severe physiological responses in most of the body systems such as cardiovascular, respiratory, skeletal, endocrine, and etc. This investigation was to assess the effect of different vibration frequencies on heart rate variability (HRV), electrocardiograms (ECG) and respiratory rate in Rhesus monkeys. Methods: two groups of rhesus monkey (n=16 in each group) was selected as control and intervention groups. Monkeys were held in a sitting position within a specific fixture. The animals of this experiment were vibrated on a table which oscillated right and left with sinusoidal motion. Frequency and acceleration for intervention group were between the range of 1 to 2000 Hz and +0.5 to +3 G during 36 weeks (one per week for 15 min), respectively. All of the animals passed the clinical evaluation (echocardiography, sonography, radiography and blood analysis test) before vibration test and were considered healthy and these tests repeated during and at the end of experiments. Results and discussions: Our results showed that heart and respiratory rates increased significantly in response to increased frequency from 1 to 60 Hz (p monkeys passed vibration experiment successfully without any arrhythmic symptoms due to electrocardiography analysis. Conclusion: Our results indicate that vibration in low frequency can effect respiratory and cardiovascular function in rhesus monkey. Keywords: Vibration, rhesus monkey, heart rate, respiratory rate

  6. Quinohemoprotein alcohol dehydrogenases: structure, function, and physiology.

    Science.gov (United States)

    Toyama, Hirohide; Mathews, F Scott; Adachi, Osao; Matsushita, Kazunobu

    2004-08-01

    Quino(hemo)protein alcohol dehydrogenases (ADH) that have pyrroloquinoline quinone (PQQ) as the prosthetic group are classified into 3 groups, types I, II, and III. Type I ADH is a simple quinoprotein having PQQ as the only prosthetic group, while type II and type III ADHs are quinohemoprotein having heme c as well as PQQ in the catalytic polypeptide. Type II ADH is a soluble periplasmic enzyme and is widely distributed in Proteobacteria such as Pseudomonas, Ralstonia, Comamonas, etc. In contrast, type III ADH is a membrane-bound enzyme working on the periplasmic surface solely in acetic acid bacteria. It consists of three subunits that comprise a quinohemoprotein catalytic subunit, a triheme cytochrome c subunit, and a third subunit of unknown function. The catalytic subunits of all the quino(hemo)protein ADHs have a common structural motif, a quinoprotein-specific superbarrel domain, where PQQ is deeply embedded in the center. In addition, in the type II and type III ADHs this subunit contains a unique heme c domain. Various type II ADHs each have a unique substrate specificity, accepting a wide variety of alcohols, as is discussed on the basis of recent X-ray crystallographic analyses. Electron transfer within both type II and III ADHs is discussed in terms of the intramolecular reaction from PQQ to heme c and also from heme to heme, and in terms of the intermolecular reaction with azurin and ubiquinone, respectively. Unique physiological functions of both types of quinohemoprotein ADHs are also discussed.

  7. Leptin in Human Physiology and Therapeutics

    Science.gov (United States)

    Dardeno, Tina A.; Chou, Sharon H.; Moon, Hyun-Seuk; Chamberland, John P.; Fiorenza, Christina G.; Mantzoros, Christos S.

    2010-01-01

    Leptin regulates energy homeostasis and reproductive, neuroendocrine, immune, and metabolic functions. In this review, we describe the role of leptin in human physiology and review evidence from recent “proof of concept” clinical trials using recombinant human leptin in subjects with congenital leptin deficiency, hypoleptinemia associated with energy-deficient states, and hyperleptinemia associated with garden-variety obesity. Since most obese individuals are largely leptin-tolerant or -resistant, therapeutic uses of leptin are currently limited to patients with complete or partial leptin deficiency, including hypothalamic amenorrhea and lipoatrophy. Leptin administration in these energy-deficient states may help restore associated neuroendocrine, metabolic, and immune function and bone metabolism. Leptin treatment is currently available for individuals with congenital leptin deficiency and congenital lipoatrophy. The long-term efficacy and safety of leptin treatment in hypothalamic amenorrhea and acquired lipoatrophy are currently under investigation. Whether combination therapy with leptin and potential leptin sensitizers will prove effective in the treatment of garden-variety obesity and whether leptin may have a role in weight loss maintenance is being greatly anticipated. PMID:20600241

  8. Anhydrobiosis in bacteria: from physiology to applications.

    Science.gov (United States)

    García, Armando Hernández

    2011-12-01

    Anhydrobiosis is a phenomenon related to the partial or total desiccation of living organisms, keeping their vital functions after rehydration. The desiccated state in prokaryotes has been widely studied, mainly due to the broad spectrum of the anhydrobiosis applications. In this review, we present the basic theoretical concepts related to anhydrobiosis, focusing on bacterial species. An update about desiccation tolerance in bacteria is given; and the general mechanisms of desiccation tolerance and desiccation damage are described. In addition, we show how the study of anhydrobiosis in prokaryotes has established the theoretical and practical basis for the development of the drying technologies. With regard to the desiccation tolerance in bacteria, although many mechanisms remain undiscovered at the molecular level, important research about the physiology of the anhydrobiotic state and its applications has been performed, and here we provide the most recent information about this subject. On the other hand, the most widely used drying technologies and their particular applications in several fields are described (e.g. medicine, agriculture and food industry). Finally, topics on the stability of desiccated bacterial cells are treated, concluding with the necessity of focusing the research on the mathematical modelling of the desiccated state in bacteria.

  9. Sixty years in algal physiology and photosynthesis.

    Science.gov (United States)

    Pirson, A

    1994-06-01

    This personal perspective records research experiences in chemistry and biology at four German universities, two before and two after World War II. The research themes came from cytophysiology of green unicellular algae, in particular their photosynthesis. The function of inorganic ions in photosynthesis and dark respiration was investigated at different degrees of specific mineral stress (deficiencies), and the kinetics of recovery followed after the addition of the missing element. Two types of recovery of photosynthesis were observed: indirect restitution via growth processes and immediate normalisation. From the latter case (K(+), phosphate, Mn(++)) the effect of manganese was emphasized as its role in photosynthetic O2 evolution became established during our research. Other themes of our group, with some bearing on photosynthesis were: synchronization of cell growth by light-dark change and effects of blue (vs. red) light on the composition of green cells. Some experiences in connection with algal mass cultures are included. Discussion of several editorial projects shows how photosynthesis, as an orginally separated field of plant biochemistry and biophysics, became included into general cell physiology and even ecophysiology of green plants. The paper contains an appreciation of the authors' main mentor Kurt Noack (1888-1963) and of Ernst Georg Pringsheim (1881-1970), founder of experimental phycology.

  10. The Cellular Physiology of Carbonic Anhydrases

    Directory of Open Access Journals (Sweden)

    Breton S

    2001-07-01

    Full Text Available Carbonic anhydrases are zinc metalloenzymes that catalyze the reversible hydration of CO(2 to form HCO(3(- and protons according to the following reaction: CO(2 + H(2O = H(2CO(3 = HCO(3(- + H(+. The first reaction is catalyzed by carbonic anhydrase and the second reaction occurs instantaneously. The carbonic anhydrase (CA gene family includes ten enzymatically active members, which are major players in many physiological processes, including renal and male reproductive tract acidification, bone resorption, respiration, gluconeogenesis, signal transduction, and formation of gastric acid. The newly identified CA IX (previously called MN and CA XII are related to cell proliferation and oncogenesis. Carbonic anhydrase isozymes have different kinetic properties and they are present in various tissues and in various cell compartments. CA I, II, III and VII are cytoplasmic, CA V is mitochondrial, and CA VI is present in salivary secretions. CA IV, IX, XII and XIV are membrane proteins: CA IV is a glycosyl-phosphatidylinositol-anchored protein, and CA IX, XII and XIV are transmembrane proteins. The present work will focus on the roles of CA II and CA IV in transepithelial proton secretion and bicarbonate reabsorption processes. The localization of these isoforms in selected epithelia that are involved in net acid/base transport, such as kidney proximal tubules and collecting ducts, and tubules from the male reproductive tract will be reviewed.

  11. Change in physiological signals during mindfulness meditation.

    Science.gov (United States)

    Ahani, Asieh; Wahbeh, Helane; Miller, Meghan; Nezamfar, Hooman; Erdogmus, Deniz; Oken, Barry

    2013-01-01

    Mindfulness meditation (MM) is an inward mental practice, in which a resting but alert state of mind is maintained. MM intervention was performed for a population of older people with high stress levels. This study assessed signal processing methodologies of electroencephalographic (EEG) and respiration signals during meditation and control condition to aid in quantification of the meditative state. EEG and respiration data were collected and analyzed on 34 novice meditators after a 6-week meditation intervention. Collected data were analyzed with spectral analysis and support vector machine classification to evaluate an objective marker for meditation. We observed meditation and control condition differences in the alpha, beta and theta frequency bands. Furthermore, we established a classifier using EEG and respiration signals with a higher accuracy at discriminating between meditation and control conditions than one using the EEG signal only. EEG and respiration based classifier is a viable objective marker for meditation ability. Future studies should quantify different levels of meditation depth and meditation experience using this classifier. Development of an objective physiological meditation marker will allow the mind-body medicine field to advance by strengthening rigor of methods.

  12. Physiological determinants of the cycling time trial.

    Science.gov (United States)

    Støren, Øyvind; Ulevåg, Kåre; Larsen, Morten H; Støa, Eva M; Helgerud, Jan

    2013-09-01

    The purpose of this study was to examine the physiological determinants of endurance cycling time trial (TT) performance in a heterogeneous group of competitive male road cyclists. About 15 male cyclists who had all competed in cycling the preceding season were tested for the anthropometric variables height, body weight, leg length, ankle circumference, and body fat percentage. They were also tested for maximal oxygen consumption (VO2max), lactate threshold (LT), metabolic cost of cycling (CC), peak power output and average power output during a 30-second Wingate test, 1 repetition maximum and peak power in half squats, and a TT test on an ergometer. Heart rate and cadence (rounds per minute, RPM) were continuously measured during all cycle tests. Pearson Bivariate correlation tests and single linear regression tests were performed to obtain correlation coefficients (r), effect size (F), standard error of estimate (SEE), and 95% confidence interval. The single variable that correlated best with TT performance was power output at LT (r = 0.86, p equation representing both aerobic and anaerobic endurance capacity TT(w) = 0.95 ([VO2max/CC] TT%VO2max) + 0.05 (Wingate average) correlated strongly with TT laboratory performance (r = 0.93, p < 0.01, SEE = 5.7%). None of the strength, power, or anthropometric variables correlated significantly with TT laboratory performance.

  13. Physiological and molecular aspects of cobalamin transport.

    Science.gov (United States)

    Fedosov, Sergey N

    2012-01-01

    Minute doses of a complex cofactor cobalamin (Cbl, vitamin B12) are essential for metabolism. The nutritional chain for humans includes: (1) production of Cbl by bacteria in the intestinal tract of herbivores; (2) accumulation of the absorbed Cbl in animal tissues; (3) consumption of food of animal origin. Most biological sources contain both Cbl and its analogues, i.e. Cbl-resembling compounds physiologically inactive in animal cells. Selective assimilation of the true vitamin requires an interplay between three transporting proteins - haptocorrin (HC), intrinsic factor (IF), transcobalamin (TC) - and several receptors. HC is present in many biological fluids, including gastric juice, where it assists in disposal of analogues. Gastric IF selectively binds dietary Cbl and enters the intestinal cells via receptor-mediated endocytosis. Absorbed Cbl is transmitted to TC and delivered to the tissues with blood flow. The complex transport system guarantees a very efficient uptake of the vitamin, but failure at any link causes Cbl-deficiency. Early detection of a negative B12 balance is highly desirable to prevent irreversible neurological damages, anaemia and death in aggravated cases. The review focuses on the molecular mechanisms of cobalamin transport with emphasis on interaction of corrinoids with the specific proteins and protein-receptor recognition. The last section briefly describes practical aspects of recent basic research concerning early detection of B12-related disorders, medical application of Cbl-conjugates, and purification of corrinoids from biological samples.

  14. Success stories and emerging themes in conservation physiology.

    Science.gov (United States)

    Madliger, Christine L; Cooke, Steven J; Crespi, Erica J; Funk, Jennifer L; Hultine, Kevin R; Hunt, Kathleen E; Rohr, Jason R; Sinclair, Brent J; Suski, Cory D; Willis, Craig K R; Love, Oliver P

    2016-01-01

    The potential benefits of physiology for conservation are well established and include greater specificity of management techniques, determination of cause-effect relationships, increased sensitivity of health and disturbance monitoring and greater capacity for predicting future change. While descriptions of the specific avenues in which conservation and physiology can be integrated are readily available and important to the continuing expansion of the discipline of 'conservation physiology', to date there has been no assessment of how the field has specifically contributed to conservation success. However, the goal of conservation physiology is to foster conservation solutions and it is therefore important to assess whether physiological approaches contribute to downstream conservation outcomes and management decisions. Here, we present eight areas of conservation concern, ranging from chemical contamination to invasive species to ecotourism, where physiological approaches have led to beneficial changes in human behaviour, management or policy. We also discuss the shared characteristics of these successes, identifying emerging themes in the discipline. Specifically, we conclude that conservation physiology: (i) goes beyond documenting change to provide solutions; (ii) offers a diversity of physiological metrics beyond glucocorticoids (stress hormones); (iii) includes approaches that are transferable among species, locations and times; (iv) simultaneously allows for human use and benefits to wildlife; and (v) is characterized by successes that can be difficult to find in the primary literature. Overall, we submit that the field of conservation physiology has a strong foundation of achievements characterized by a diversity of conservation issues, taxa, physiological traits, ecosystem types and spatial scales. We hope that these concrete successes will encourage the continued evolution and use of physiological tools within conservation-based research and management

  15. [CNC proteins in physiology and pathology].

    Science.gov (United States)

    Gęgotek, Agnieszka; Skrzydlewska, Elżbieta

    2015-07-06

    CNC proteins consist of Bach1, Bach2 and 4 homologous transcription factors: Nrf1, Nrf2, Nrf3 and p45NF-E2. Transcription factors belonging to this group of proteins play a crucial role in protection of cells against oxidative stress. Under physiological conditions, they remain in the cytoplasm in the inactive form or are degraded. However, in oxidative stress conditions, they are translocated to the nucleus, and bind to DNA in the ARE sequence. Consequently, there is transcription of genes encoding cytoprotective proteins, such as phase II enzymes, or low molecular weight antioxidant proteins (i.e., thioredoxin, ferritin, metallothionein) responsible for protecting cells from reactive oxygen species (ROS) action. The activity of transcriptional proteins depends directly on the redox state of the cell. ROS as second messenger signals, control inhibitors of cytoplasmic CNC proteins or potentiate the activity of kinases (MAPK, PKC, PI3K, PERK), leading to phosphorylation of transcription factors. This is conducive to translocation of these molecules into the nucleus and to formation of complexes that initiate the gene expression. Disorders of regulation of the activity of transcription factors belonging to the CNC proteins caused by gene mutations, epigenetic modifications or increased activity of p62, p21, or k-Ras, B-Raf and c-Myc oncogenes, induce changes in the level of ARE-dependent gene expression, which can lead even to the development of carcinogenesis. On the other hand, Nrf transcription factors, inducing the expression of antioxidants and enzymes responsible for the detoxification of xenobiotics, can be considered as a potential target of the action of chemopreventive factors in anticancer therapy.

  16. Human Physiology in an Aquatic Environment.

    Science.gov (United States)

    Pendergast, David R; Moon, Richard E; Krasney, John J; Held, Heather E; Zamparo, Paola

    2015-09-20

    Water covers over 70% of the earth, has varying depths and temperatures and contains much of the earth's resources. Head-out water immersion (HOWI) or submersion at various depths (diving) in water of thermoneutral (TN) temperature elicits profound cardiorespiratory, endocrine, and renal responses. The translocation of blood into the thorax and elevation of plasma volume by autotransfusion of fluid from cells to the vascular compartment lead to increased cardiac stroke volume and output and there is a hyperperfusion of some tissues. Pulmonary artery and capillary hydrostatic pressures increase causing a decline in vital capacity with the potential for pulmonary edema. Atrial stretch and increased arterial pressure cause reflex autonomic responses which result in endocrine changes that return plasma volume and arterial pressure to preimmersion levels. Plasma volume is regulated via a reflex diuresis and natriuresis. Hydrostatic pressure also leads to elastic loading of the chest, increasing work of breathing, energy cost, and thus blood flow to respiratory muscles. Decreases in water temperature in HOWI do not affect the cardiac output compared to TN; however, they influence heart rate and the distribution of muscle and fat blood flow. The reduced muscle blood flow results in a reduced maximal oxygen consumption. The properties of water determine the mechanical load and the physiological responses during exercise in water (e.g. swimming and water based activities). Increased hydrostatic pressure caused by submersion does not affect stroke volume; however, progressive bradycardia decreases cardiac output. During submersion, compressed gas must be breathed which introduces the potential for oxygen toxicity, narcosis due to nitrogen, and tissue and vascular gas bubbles during decompression and after may cause pain in joints and the nervous system.

  17. Ghrelin in obesity, physiological and pharmacological considerations.

    Science.gov (United States)

    Álvarez-Castro, Paula; Pena, Lara; Cordido, Fernando

    2013-04-01

    The aim of this review is to summarize the physiological and pharmacological aspects of ghrelin. Obesity can be defined as an excess of body fat and is associated with significant disturbances in metabolic and endocrine function. Obesity has become a worldwide epidemic. In obesity there is a decreased growth hormone (GH) secretion, and the altered somatotroph secretion in obesity is functional. Ghrelin is a peptide that has a unique structure with 28 amino-acids and an n-octanoyl ester at its third serine residue, which is essential for its potent stimulatory activity on somatotroph secretion. The pathophysiological mechanism responsible for GH hyposecretion in obesity is probably multifactorial, and there is probably a defect in ghrelin secretion. Ghrelin is the only known circulating orexigenic factor, and has been found to be reduced in obese humans. Ghrelin levels in blood decrease during periods of feeding. Due to its orexigenic and metabolic effects, ghrelin has a potential benefit in antagonizing protein breakdown and weight loss in catabolic conditions such as cancer cachexia, renal and cardiac disease, and age-related frailty. Theoretically ghrelin receptor antagonists could be employed as anti-obesity drugs, blocking the orexigenic signal. By blocking the constitutive receptor activity, inverse agonists of the ghrelin receptor may lower the set-point for hunger, and could be used for the treatment of obesity. In summary, ghrelin secretion is reduced in obesity, and could be partly responsible for GH hyposecretion in obesity, ghrelin antagonist or partial inverse agonists should be considered for the treatment of obesity.

  18. [Endothelial microparticles (EMP) in physiology and pathology].

    Science.gov (United States)

    Sierko, Ewa; Sokół, Monika; Wojtukiewicz, Marek Z

    2015-08-18

    Endothelial microparticles (EMP) are released from endothelial cells (ECs) in the process of activation and/or apoptosis. They harbor adhesive molecules, enzymes, receptors and cytoplasmic structures and express a wide range of various constitutive antigens, typical for ECs, at their surface. Under physiological conditions the concentration of EMP in the blood is clinically insignificant. However, it was reported that under pathological conditions EMP concentration in the blood might slightly increase and contribute to blood coagulation, angiogenesis and inflammation. It has been shown that EMP directly and indirectly contribute to the activation of blood coagulation. Endothelial microparticles directly participate in blood coagulation through their surface tissue factor (TF) - a major initiator of blood coagulation. Furthermore, EMP exhibit procoagulant potential via expression of negatively charged phospholipids at their surface, which may promote assembly of coagulation enzymes (TF/VII, tenases and prothrombinase complexes), leading to thrombus formation. In addition, they provide a binding surface for coagulation factors: IXa, VIII, Va and IIa. Moreover, it is possible that EMP transfer TF from TF-bearing EMP to activated platelets and monocytes by binding them through adhesion molecules. Also, EMP express von Willebrand factor, which may facilitate platelet aggregation. Apart from their procoagulant properties, it was demonstrated that EMP may express adhesive molecules and metalloproteinases (MMP-2, MMP-9) at their surface and release growth factors, which may contribute to angiogenesis. Additionally, surface presence of C3 and C4 - components of the classical pathway - suggests pro-inflammatory properties of these structures. This article contains a summary of available data on the biology and pathophysiology of endothelial microparticles and their potential role in blood coagulation, angiogenesis and inflammation.

  19. Stress Physiology of Lactic Acid Bacteria.

    Science.gov (United States)

    Papadimitriou, Konstantinos; Alegría, Ángel; Bron, Peter A; de Angelis, Maria; Gobbetti, Marco; Kleerebezem, Michiel; Lemos, José A; Linares, Daniel M; Ross, Paul; Stanton, Catherine; Turroni, Francesca; van Sinderen, Douwe; Varmanen, Pekka; Ventura, Marco; Zúñiga, Manuel; Tsakalidou, Effie; Kok, Jan

    2016-09-01

    Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.

  20. Physiological Synchronization in a Vigilance Dual Task.

    Science.gov (United States)

    Guastello, Stephen J

    2016-01-01

    The synchronization of autonomic arousal levels and other physio-logical responses between people is a potentially important component of work team performance, client-therapist relationships, and other types of human interaction. This study addressed several problems: What statistical models are viable for identifying synchronization for loosely coupled human systems? How is the level of synchronization related to psychosocial variables such as empathy, subjective ratings of workload, and actual performance? Participants were 70 undergraduates who worked in pairs on a vigilance dual task in which they watched a virtual reality security camera, rang a bell when they saw the target intruder, and completed a jig-saw puzzle. Event rates either increased or decreased during the 90 min work period. The average R2 values for each person were .66, .66, .62, and .53 for the linear autoregressive model, linear autoregressive model with a synchronization component, the nonlinear autoregressive model, and the nonlinear autoregressive model with a synchronization component, respectively. All models were more accurate at a lag of 20 sec compared to 50 sec or customized lag lengths. Although the linear models were more accurate overall, the nonlinear synchronization parameters were more often related to psychological variables and performance. In particular, greater synchronization was observed with the nonlinear model when the target event rate increased, compared to when it decreased, which was expected from the general theory of synchronization. Nonlinear models were also more effective for uncovering inhibitory or dampening relationships between the co-workers as well as mutually excitatory relationships. Future research should explore the comparative model results for tasks that induce higher levels of synchronization and involve different types of internal group coordination.

  1. A semiparametric approach to physiological flow models.

    Science.gov (United States)

    Verotta, D; Sheiner, L B; Ebling, W F; Stanski, D R

    1989-08-01

    By regarding sampled tissues in a physiological model as linear subsystems, the usual advantages of flow models are preserved while mitigating two of their disadvantages, (i) the need for assumptions regarding intratissue kinetics, and (ii) the need to simultaneously fit data from several tissues. To apply the linear systems approach, both arterial blood and (interesting) tissue drug concentrations must be measured. The body is modeled as having an arterial compartment (A) distributing drug to different linear subsystems (tissues), connected in a specific way by blood flow. The response (CA, with dimensions of concentration) of A is measured. Tissues receive input from A (and optionally from other tissues), and send output to the outside or to other parts of the body. The response (CT, total amount of drug in the tissue (T) divided by the volume of T) from the T-th one, for example, of such tissues is also observed. From linear systems theory, CT can be expressed as the convolution of CA with a disposition function, F(t) (with dimensions 1/time). The function F(t) depends on the (unknown) structure of T, but has certain other constant properties: The integral integral infinity0 F(t) dt is the steady state ratio of CT to CA, and the point F(0) is the clearance rate of drug from A to T divided by the volume of T. A formula for the clearance rate of drug from T to outside T can be derived. To estimate F(t) empirically, and thus mitigate disadvantage (i), we suggest that, first, a nonparametric (or parametric) function be fitted to CA data yielding predicted values, CA, and, second, the convolution integral of CA with F(t) be fitted to CT data using a deconvolution method. By so doing, each tissue's data are analyzed separately, thus mitigating disadvantage (ii). A method for system simulation is also proposed. The results of applying the approach to simulated data and to real thiopental data are reported.

  2. The physiology of growth hormone and sport.

    LENUS (Irish Health Repository)

    Widdowson, W Matthew

    2012-02-01

    The growth hormone (GH)\\/ insulin-like growth factor-I (IGF-I) axis exerts short-and long-term metabolic effects that are potentially important during exercise. Exercise is a potent stimulus to GH release and there is some evidence that the acute increase in GH is important in regulating substrate metabolism post-exercise. Regular exercise also increases 24-hour GH secretion rates, which potentially contributes to the physiologic changes induced by training. The effects of GH replacement in GH-deficient adults provide a useful model with which to study the effects of the more long-term effects of the GH\\/ IGF-I axis. There is convincing evidence that GH replacement increases exercise capacity. Measures of exercise performance including maximal oxygen uptake (VO2max) and ventilatory threshold (VeT) are impaired in GH deficiency and improved by GH replacement, probably through some combination of increased oxygen delivery to exercising muscle, increased fatty acid availability with glycogen sparing, increased muscle strength, improved body composition and improved thermoregulation. Administration of supraphysiologic doses of GH to athletes increases fatty acid availability and reduces oxidative protein loss particularly during exercise, and increases lean body mass. It is not known whether these effects translate to improved athletic performance, although recombinant human GH is known to be widely abused in sport. The model of acromegaly provides evidence that long-term GH excess does not result in improved performance but it is possible that a "window" exists in which the protein anabolic effects of supraphysiologic GH might be advantageous.

  3. CNC proteins in physiology and pathology

    Directory of Open Access Journals (Sweden)

    Agnieszka Gęgotek

    2015-07-01

    Full Text Available CNC proteins consist of Bach1, Bach2 and 4 homologous transcription factors: Nrf1, Nrf2, Nrf3 and p45NF-E2. Transcription factors belonging to this group of proteins play a crucial role in protection of cells against oxidative stress. Under physiological conditions, they remain in the cytoplasm in the inactive form or are degraded. However, in oxidative stress conditions, they are translocated to the nucleus, and bind to DNA in the ARE sequence. Consequently, there is transcription of genes encoding cytoprotective proteins, such as phase II enzymes, or low molecular weight antioxidant proteins (i.e., thioredoxin, ferritin, metallothionein responsible for protecting cells from reactive oxygen species (ROS action. The activity of transcriptional proteins depends directly on the redox state of the cell. ROS as second messenger signals, control inhibitors of cytoplasmic CNC proteins or potentiate the activity of kinases (MAPK, PKC, PI3K, PERK, leading to phosphorylation of transcription factors. This is conducive to translocation of these molecules into the nucleus and to formation of complexes that initiate the gene expression. Disorders of regulation of the activity of transcription factors belonging to the CNC proteins caused by gene mutations, epigenetic modifications or increased activity of p62, p21, or k-Ras, B-Raf and c-Myc oncogenes, induce changes in the level of ARE-dependent gene expression, which can lead even to the development of carcinogenesis. On the other hand, Nrf transcription factors, inducing the expression of antioxidants and enzymes responsible for the detoxification of xenobiotics, can be considered as a potential target of the action of chemopreventive factors in anticancer therapy.

  4. Digestive Physiological Characteristics of the Gobiidae

    Science.gov (United States)

    Hur, Sang-Woo; Kim, Shin-Kwon; Kim, Dae-Jung; Lee, Bae-Ik; Park, Su-Jin; Hwang, Hyung-Gyu; Jun, Je-Cheon; Myeong, Jeong-In; Lee, Chi-Hoon; Lee, Young-Don

    2016-01-01

    In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portion (P<0.05), while CCK-producing cells are scattered throughout the intestine. Gluttonous goby (Chasmichthys gulosus), which is stomach fish, mucus-secreting goblet cells are most abundant in the mid intestine portion (P<0.05), whereas CCK-producing cells are observed only in the anterior and mid intestine portion. Trident goby (Tridentiger obscurus) which is stomach fish, mucus-secreting goblet cells were most abundant in the mid intestine portion (P<0.05). CCK-producing cells are found in the anterior and mid intestine portion. Giurine goby, Rhinogobius giurinus which is also stomach fish, the largest number of mucus-secreting goblet cells showed in anterior intestine portion except for esophagus (P<0.05). CCK-producing cells are present only in the anterior and mid intestine portion. In S. geneionema, digestive action occurs in the posterior intestine portion to protect and functions to activate digestion. In contrast, in C. gulosus, T. obscurus and R. giurinus, their digestive action occurs in the anterior and mid intestine portion to protect and functions to activate digestion. Further studies of the modes of food ingestion by these fish, the contents of their digestive tracts, and the staining characteristics of the goblet cells need to be carried out. PMID:27796002

  5. Claude Bernard and his revelations in physiology.

    Science.gov (United States)

    Breathnach, C S

    2014-03-01

    It was in Saint-Julien near Villefranche that Claude Bernard was born on 12 July 1813. About 20 years later he moved to Paris to become a dramatist but was directed into the study of medicine, the service at the Hôtel Dieu of Magendie that led him to the Collège de France. He entered Magendie's laboratory as a voluntary assistant and within a year became official préparateur. His early work on the chorda tympani and his MD thesis on gastric juice in 1843 set him on his lifelong discoveries in physiology. The central role of hepatic glycogenesis in the formation of sugar in animals was established around 1850, and he proceeded to show that section of the cervical fibres of the sympathetic chain led to congestion and increased temperature on that side of the face-resulting from paralysis of the vasomotor nerves. And there were vasodilator as well as vasoconstrictor fibres. After the salivary glands, the pancreas caught his attention and he discovered its ability to emulsify fatty material. Toxic and therapeutic substances were analysed: carbon monoxide paralyses carriage of oxygen by taking its place on haemoglobin; and curare abolishes voluntary movement by paralysis at the motor end-plate. But Bernard was above all a general physiologist, exemplified in 1872 and 1873 in his Lectures on the phenomena of life common to animals and plants, summarised in the aperçu 'the constancy of the internal environment is the condition of the free and independent life'. Claude Bernard died on Sunday 10 February 1878 in Paris.

  6. GFR estimation: from physiology to public health.

    Science.gov (United States)

    Levey, Andrew S; Inker, Lesley A; Coresh, Josef

    2014-05-01

    Estimating glomerular filtration rate (GFR) is essential for clinical practice, research, and public health. Appropriate interpretation of estimated GFR (eGFR) requires understanding the principles of physiology, laboratory medicine, epidemiology, and biostatistics used in the development and validation of GFR estimating equations. Equations developed in diverse populations are less biased at higher GFRs than equations developed in chronic kidney disease (CKD) populations and are more appropriate for general use. Equations that include multiple endogenous filtration markers are more precise than equations including a single filtration marker. The CKD-EPI (CKD Epidemiology Collaboration) equations are the most accurate GFR estimating equations that have been evaluated in large diverse populations and are applicable for general clinical use. The 2009 CKD-EPI creatinine equation is more accurate in estimating GFR and prognosis than the 2006 MDRD (Modification of Diet in Renal Disease) Study equation and provides lower estimates of prevalence of decreased eGFR. It is useful as a "first test" for decreased eGFR and should replace the MDRD Study equation for routine reporting of serum creatinine-based eGFR by clinical laboratories. The 2012 CKD-EPI cystatin C equation is as accurate as the 2009 CKD-EPI creatinine equation in estimating GFR, does not require specification of race, and may be more accurate in patients with decreased muscle mass. The 2012 CKD-EPI creatinine-cystatin C equation is more accurate than the 2009 CKD-EPI creatinine and 2012 CKD-EPI cystatin C equations and is useful as a confirmatory test for decreased eGFR as determined by serum creatinine-based eGFR. Further improvement in GFR estimating equations will require development in more broadly representative populations, including diverse racial and ethnic groups, use of multiple filtration markers, and evaluation using statistical techniques to compare eGFR to "true GFR."

  7. The physiological basis of bird flight.

    Science.gov (United States)

    Butler, Patrick J

    2016-09-26

    Flapping flight is energetically more costly than running, although it is less costly to fly a given body mass a given distance per unit time than it is for a similar mass to run the same distance per unit time. This is mainly because birds can fly faster than they can run. Oxygen transfer and transport are enhanced in migrating birds compared with those in non-migrators: at the gas-exchange regions of the lungs the effective area is greater and the diffusion distance smaller. Also, migrating birds have larger hearts and haemoglobin concentrations in the blood, and capillary density in the flight muscles tends to be higher. Species like bar-headed geese migrate at high altitudes, where the availability of oxygen is reduced and the energy cost of flapping flight increased compared with those at sea level. Physiological adaptations to these conditions include haemoglobin with a higher affinity for oxygen than that in lowland birds, a greater effective ventilation of the gas-exchange surface of the lungs and a greater capillary-to-muscle fibre ratio. Migrating birds use fatty acids as their source of energy, so they have to be transported at a sufficient rate to meet the high demand. Since fatty acids are insoluble in water, birds maintain high concentrations of fatty acid-binding proteins to transport fatty acids across the cell membrane and within the cytoplasm. The concentrations of these proteins, together with that of a key enzyme in the β-oxidation of fatty acids, increase before migration.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'.

  8. Liver X receptors and epididymal epithelium physiology

    Institute of Scientific and Technical Information of China (English)

    Fabrice Saez; Eléonore Chabory; Rémi Cadet; Patrick Vernet; Silvère Baron; Jean-Marc A. Lobaccaro; Jo(e)l R. Drevet

    2007-01-01

    Aim: To investigate the roles of liver X receptors (LXR) in the lipid composition and gene expression regulation in the murine caput epididymidis. LXR are nuclear receptors for oxysterols, molecules derived from cholesterol metabolism that are present in mammals as two isoforms: LXRα, which is more specifically expressed in lipid-metabolising tissues, such as liver, adipose and steroidogenic tissues, and macrophages, whereas LXRβ is ubiquitous. Their importance in reproductive physiology has been sustained by the fact that male mice in which the function of both LXR has been disrupted have fertility disturbances starting at the age of 5 months, leading to complete sterility by the age of 9 months. These defects are associated with epididymal epithelial degeneration in caput segments one and two,and with a sperm midpiece fragility, leading to the presence of isolated sperm heads and flagella when luminal contents are recovered from the canda epididymidis. Methods: The lipid composition of the caput epididymidis of wild-type and LXR-deficient mice was assessed using oil red O staining on tissue cryosections and lipid extraction followed by high performance liquid chromatography or gas chromatography. Gene expression was checked by quantitative real time polymerase chain reaction. Results: Using LXR-deficient mice, we showed an alteration of the lipid composition of the caput epididymidis as well as a significantly decreased expression of the genes encoding SREBPlc, SCD 1 and SCD2, involved in fatty acid metabolism. Conclusion: Altogether, these results show that LXR are important regulators of epididymal function, and play a critical role in the lipid maturation processes occurring during sperm epididymal maturation.

  9. The physiology of growth hormone and sport.

    Science.gov (United States)

    Widdowson, W Matthew; Healy, Marie-Louise; Sönksen, Peter H; Gibney, James

    2009-08-01

    The growth hormone (GH)/ insulin-like growth factor-I (IGF-I) axis exerts short-and long-term metabolic effects that are potentially important during exercise. Exercise is a potent stimulus to GH release and there is some evidence that the acute increase in GH is important in regulating substrate metabolism post-exercise. Regular exercise also increases 24-hour GH secretion rates, which potentially contributes to the physiologic changes induced by training. The effects of GH replacement in GH-deficient adults provide a useful model with which to study the effects of the more long-term effects of the GH/ IGF-I axis. There is convincing evidence that GH replacement increases exercise capacity. Measures of exercise performance including maximal oxygen uptake (VO2max) and ventilatory threshold (VeT) are impaired in GH deficiency and improved by GH replacement, probably through some combination of increased oxygen delivery to exercising muscle, increased fatty acid availability with glycogen sparing, increased muscle strength, improved body composition and improved thermoregulation. Administration of supraphysiologic doses of GH to athletes increases fatty acid availability and reduces oxidative protein loss particularly during exercise, and increases lean body mass. It is not known whether these effects translate to improved athletic performance, although recombinant human GH is known to be widely abused in sport. The model of acromegaly provides evidence that long-term GH excess does not result in improved performance but it is possible that a "window" exists in which the protein anabolic effects of supraphysiologic GH might be advantageous.

  10. Physiological Regulation and Infantile Anorexia: A Pilot Study

    Science.gov (United States)

    Chatoor, Irene; Ganiban, Jody; Surles, Jaclyn; Doussard-Roosevelt, Jane

    2004-01-01

    Objective: To examine whether infantile anorexia is associated with physiological dysregulation. Method: This study included eight toddlers with infantile anorexia and eight healthy eaters matched for age, race, socioeconomic status, and gender. Physiological measures of heart period and respiratory sinus arrhythmia were assessed across three…

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

    Science.gov (United States)

    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.

  12. Teaching Acid/Base Physiology in the Laboratory

    Science.gov (United States)

    Friis, Ulla G.; Plovsing, Ronni; Hansen, Klaus; Laursen, Bent G.; Wallstedt, Birgitta

    2010-01-01

    Acid/base homeostasis is one of the most difficult subdisciplines of physiology for medical students to master. A different approach, where theory and practice are linked, might help students develop a deeper understanding of acid/base homeostasis. We therefore set out to develop a laboratory exercise in acid/base physiology that would provide…

  13. Current Practices in the Delivery of Undergraduate Exercise Physiology Content

    Science.gov (United States)

    Fisher, Michele M.

    2013-01-01

    The purpose of this study was to identify current practices for the delivery of exercise physiology content at the undergraduate level. An anonymous 22-item survey was sent to instructors of exercise physiology to collect information concerning the structure of course offerings and instructional practices. One hundred ten instructors responded to…

  14. Establishing Common Course Objectives for Undergraduate Exercise Physiology

    Science.gov (United States)

    Simonson, Shawn R.

    2015-01-01

    Undergraduate exercise physiology is a ubiquitous course in undergraduate kinesiology/exercise science programs with a broad scope and depth of topics. It is valuable to explore what is taught within this course. The purpose of the present study was to facilitate an understanding of what instructors teach in undergraduate exercise physiology, how…

  15. Is Physiology the Locus of Health/Health Promotion?

    Science.gov (United States)

    Zbilut, Joseph P.

    2008-01-01

    A current trend in physiology education involves the use of clinical vignettes to demonstrate the importance of knowing normal physiology to appreciate pathophysiology. Although laudable, in effect, such tactics promote the so-called "disease" model of medicine while at the same time suggesting that the only utility for the knowledge of physiology…

  16. ACDP Survey on Use of Animals in Teaching Physiology.

    Science.gov (United States)

    Greenwald, Gilbert S.

    1985-01-01

    Association of Chairmen of Departments of Physiology (ACDP) members were surveyed to provide data on use of animals in physiology teaching. Information derived from the 88 surveys completed and returned (135 were mailed) are presented in a copy of the instrument. One question lists alternatives to using live animals. (JN)

  17. Physiological stress reactivity in human pregnancy - a review

    NARCIS (Netherlands)

    Weerth, C. de; Buitelaar, J.K.

    2005-01-01

    Prenatal maternal stress has been found to have long-lasting effects on the behavioral and physiological development of the offspring. These programming effects on the fetus would be physiologically mediated through heightened and/or abnormal activity of the maternal sympathetic-adrenal-medullary sy

  18. The physiological and biochemical bases of functional brain imaging

    OpenAIRE

    2007-01-01

    Functional brain imaging is based on the display of computer-derived images of changes in physiological and/or biochemical functions altered by activation or depression of local functional activities in the brain. This article reviews the physiological and biochemical mechanisms involved.

  19. Physiological stress reactivity in human pregnancy--a review.

    NARCIS (Netherlands)

    Weerth, C. de; Buitelaar, J.K.

    2005-01-01

    Prenatal maternal stress has been found to have long-lasting effects on the behavioral and physiological development of the offspring. These programming effects on the fetus would be physiologically mediated through heightened and/or abnormal activity of the maternal sympathetic-adrenal-medullary sy

  20. Towards a physiological feeding strategy for protein in broilers

    NARCIS (Netherlands)

    Doeschate, ten R.A.H.M.

    1995-01-01

    The present thesis describes the development of a physiological feeding strategy for protein in broilers. This project was initiated to improve the efficiency of deposition of dietary nitrogen into animal product in order to reduce nitrogen excretion to the environment. The physiological

  1. Towards a physiological feeding strategy for protein in broilers.

    NARCIS (Netherlands)

    Doeschate, ten R.A.H.M.

    1995-01-01

    The present thesis describes the development of a physiological feeding strategy for protein in broilers. This project was initiated to improve the efficiency of deposition of dietary nitrogen into animal product in order to reduce nitrogen excretion to the environment. The physiological feeding str

  2. Towards a physiological feeding strategy for protein in broilers

    NARCIS (Netherlands)

    Doeschate, ten R.A.H.M.

    1995-01-01

    The present thesis describes the development of a physiological feeding strategy for protein in broilers. This project was initiated to improve the efficiency of deposition of dietary nitrogen into animal product in order to reduce nitrogen excretion to the environment. The physiological fe

  3. Physiological stress reactivity in human pregnancy--a review.

    NARCIS (Netherlands)

    Weerth, C. de; Buitelaar, J.K.

    2005-01-01

    Prenatal maternal stress has been found to have long-lasting effects on the behavioral and physiological development of the offspring. These programming effects on the fetus would be physiologically mediated through heightened and/or abnormal activity of the maternal sympathetic-adrenal-medullary

  4. Physiological stress reactivity in human pregnancy - a review

    NARCIS (Netherlands)

    Weerth, C. de; Buitelaar, J.K.

    2005-01-01

    Prenatal maternal stress has been found to have long-lasting effects on the behavioral and physiological development of the offspring. These programming effects on the fetus would be physiologically mediated through heightened and/or abnormal activity of the maternal sympathetic-adrenal-medullary

  5. Applied Cardiovascular Physiology in Dogs with Heart Failure

    Directory of Open Access Journals (Sweden)

    Iván Álvarez Ramírez

    2011-06-01

    Full Text Available Congestive heart failure is related to abnormal ventricular contraction and relaxation. Recent publications show that the alteration of systolic and diastolic function coexists in most patients with heart diseases. There are currently several ambiguities in the daily use of clinical and physiological terms regarding this topic. This paper aims to review certain physiological concepts of the cardiovascular system.

  6. Students' Motivation toward Laboratory Work in Physiology Teaching

    Science.gov (United States)

    Dohn, Niels Bonderup; Fago, Angela; Overgaard, Johannes; Madsen, Peter Teglberg; Malte, Hans

    2016-01-01

    The laboratory has been given a central role in physiology education, and teachers report that it is motivating for students to undertake experimental work on live animals or measuring physiological responses on the students themselves. Since motivation is a critical variable for academic learning and achievement, then we must concern ourselves…

  7. Physiological responses to environmental factors related to space flight

    Science.gov (United States)

    Pace, N.; Grunbaum, B. W.; Kodama, A. M.; Mains, R. C.; Rahlmann, D. F.

    1975-01-01

    Physiological procedures and instrumentation developed for the measurement of hemodynamic and metabolic parameters during prolonged periods of weightlessness are described along with the physiological response of monkeys to weightlessness. Specific areas examined include: cardiovascular studies; thyroid function; blood oxygen transport; growth and reproduction; excreta analysis for metabolic balance studies; and electrophoretic separation of creatine phosphokinase isoenzymes in human blood.

  8. Development of a Manipulative for Nephron Physiology Education

    Science.gov (United States)

    Giffen, Zane C.; Carvalho, Helena

    2015-01-01

    Some physiological concepts, such as physiology of filtration and absorption in the different nephron segments, are so detailed that they can be a challenge to be memorized. This article describes an exercise that solidifies learning as students manipulate, using paper models, "transporters" and "electrolytes" in the…

  9. Evaluation of the Virtual Physiology of Exercise Laboratory Program

    Science.gov (United States)

    Dobson, John L.

    2009-01-01

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

  10. Emotion of Physiological Signals Classification Based on TS Feature Selection

    Institute of Scientific and Technical Information of China (English)

    Wang Yujing; Mo Jianlin

    2015-01-01

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

  11. Physiology of Women's Sexual Function : Basic Knowledge and New Findings

    NARCIS (Netherlands)

    Salonia, Andrea; Giraldi, Annamaria; Chivers, Meredith L.; Georgiadis, Janniko R.; Levin, Roy; Maravilla, Kenneth R.; McCarthy, Margaret M.

    2010-01-01

    Introduction. Data concerning the physiology of female sexual functioning are still obtained from animal studies, but an increasing amount of novel evidence comes from human studies. Aim. To gain knowledge of psychological and biologic physiology of women's sexual functioning, mainly addressing sexu

  12. Methodological Advances for Detecting Physiological Synchrony During Dyadic Interactions

    NARCIS (Netherlands)

    McAssey, M.P.; Helm, J.; Hsieh, F.; Sbarra, D.; Ferrer, E.

    2011-01-01

    A defining feature of many physiological systems is their synchrony and reciprocal influence. An important challenge, however, is how to measure such features. This paper presents two new approaches for identifying synchrony between the physiological signals of individuals in dyads. The approaches a

  13. Biomechanics, Exercise Physiology, and the 75th Anniversary of RQES

    Science.gov (United States)

    Hamill, Joseph; Haymes, Emily M.

    2005-01-01

    The purpose of this paper is to review the biomechanics and exercise physiology studies published in the Research Quarterly for Exercise and Sport (RQES) over the past 75 years. Studies in biomechanics, a relatively new subdiscipline that evolved from kinesiology, first appeared in the journal about 40 years ago. Exercise physiology studies have…

  14. Beyond the Printed Page: Physiology Education without a Textbook?

    Science.gov (United States)

    Stavrianeas, Stasinos; Stewart, Mark; Harmer, Peter

    2008-01-01

    Pedagogical innovations, ideas, and outcomes designed to enhance student learning in physiology courses are encouraged by our professional organizations and are actively discussed at conferences and in "Advances in Physiological Education." Here, we report our experiment with freely available internet-based material as a substitute for the…

  15. Teaching Acid/Base Physiology in the Laboratory

    Science.gov (United States)

    Friis, Ulla G.; Plovsing, Ronni; Hansen, Klaus; Laursen, Bent G.; Wallstedt, Birgitta

    2010-01-01

    Acid/base homeostasis is one of the most difficult subdisciplines of physiology for medical students to master. A different approach, where theory and practice are linked, might help students develop a deeper understanding of acid/base homeostasis. We therefore set out to develop a laboratory exercise in acid/base physiology that would provide…

  16. Physiology of Women's Sexual Function : Basic Knowledge and New Findings

    NARCIS (Netherlands)

    Salonia, Andrea; Giraldi, Annamaria; Chivers, Meredith L.; Georgiadis, Janniko R.; Levin, Roy; Maravilla, Kenneth R.; McCarthy, Margaret M.

    Introduction. Data concerning the physiology of female sexual functioning are still obtained from animal studies, but an increasing amount of novel evidence comes from human studies. Aim. To gain knowledge of psychological and biologic physiology of women's sexual functioning, mainly addressing

  17. Animal reproduction and physiology: from basis to application

    Institute of Scientific and Technical Information of China (English)

    GUI JianFang

    2010-01-01

    @@ Animal reproduction and physiology is one of the traditional subjects in biology, and also one of the most rapidly developing fields because it is related to human food requirements.Along with advances in the life sciences and biotechnology, animal reproduction and physiology has achieved new theoretical developments and potential applications.

  18. Towards Integration of Biological and Physiological Functions at Multiple Levels

    Directory of Open Access Journals (Sweden)

    Taishin eNomura

    2010-12-01

    Full Text Available An aim of systems physiology today can be stated as to establish logical and quantitative bridges between phenomenological attributes of physiological entities such as cells and organs and physical attributes of biological entities, i.e., biological molecules, allowing us to describe and better understand physiological functions in terms of underlying biological functions. This article illustrates possible schema that can be used for promoting systems physiology by integrating quantitative knowledge of biological and physiological functions at multiple levels of time and space with the use of information technology infrastructure. Emphasis will be made for systematic, modular, hierarchical, and standardized descriptions of mathematical models of the functions and advantages for the use of them.

  19. Regulation and function of AMPK in physiology and diseases.

    Science.gov (United States)

    Jeon, Sang-Min

    2016-07-15

    5'-adenosine monophosphate (AMP)-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that was originally identified as the key player in maintaining cellular energy homeostasis. Intensive research over the last decade has identified diverse molecular mechanisms and physiological conditions that regulate the AMPK activity. AMPK regulates diverse metabolic and physiological processes and is dysregulated in major chronic diseases, such as obesity, inflammation, diabetes and cancer. On the basis of its critical roles in physiology and pathology, AMPK is emerging as one of the most promising targets for both the prevention and treatment of these diseases. In this review, we discuss the current understanding of the molecular and physiological regulation of AMPK and its metabolic and physiological functions. In addition, we discuss the mechanisms underlying the versatile roles of AMPK in diabetes and cancer.

  20. Satellite-detected fluorescence reveals global physiology of ocean phytoplankton

    Directory of Open Access Journals (Sweden)

    M. J. Behrenfeld

    2008-11-01

    Full Text Available Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we use satellite-based fluorescence measurements to evaluate light-absorption and energy-dissipation processes influencing phytoplankton light use efficiency and demonstrate its utility as a global physiological indicator of iron-limited growth conditions. This new tool provides a path for monitoring climate-phytoplankton physiology interactions, improving descriptions of light use efficiency in ocean productivity models, evaluating nutrient-stress predictions in ocean ecosystem models, and appraising phytoplankton responses to natural iron enrichments or purposeful iron fertilizations activities.