Segui questo link per vedere altri tipi di pubblicazioni sul tema: Physiological.
Tesi sul tema "Physiological"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Physiological".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Brauns, Seth Clint Aron. "Physiological and non-physiological induction of gastrointestinal differentiation". Thesis, University of Port Elizabeth, 1999. http://hdl.handle.net/10948/d1015521.
Testo completoAbstract (sommario):
The human colonic carcinoma cell lines HT-29 and Caco-2 both exhibit structural and functional differentiation under appropriate culture conditions. HT-29 can be induced to differentiate by treatment with short-chain fatty acids or acetoacetate. Caco-2 cells differentiate spontaneously upon contact inhibition. In this study HT-29 cells were treated with 5 mM acetate, propionate, butyrate and acetoacetate (physiological inducers) to assess their effects on the expression of carbonic anhydrase 1, sucrase-isomaltase and alkaline phosphatase which are reported to be markers of gastrointestinal differentiation. The maturation induction observed was compared to that of the spontaneous differentiation observed in Caco-2 cells. Assays were performed over an 18 day period. Results showed a close correlation (p < 0.05) between HT-29 and Caco-2 cell on days 4 and 12. These results indicate that differentiation reported in both cell lines is comparable and can be used as a basis for further comparative studies. In addition, parallel experiments to the above were conducted using a selection of nine rationally designed cyclic dipeptides (CDPs) potential drug entities which were chosen as non-physiological inducers. The results showed that the cyclic dipeptides were able to induce the gastrointestinal phenotype as observed in HT-29 cells treated with physiological inducers. Studies on the effects of energy-related metabolism in HT-29 and Caco-2 cells as induced by physiological and non-physiological inducers indicated that energy metabolism is a significant role player in gastrointestinal differentiation. The results reported show a decrease in ATP concentrations indicating that the cyclic dipeptides, like physiological inducers, affect the energy state of the HT-29 cells and thus may effect the differentiation of these cells. A positive correlation was found between histone phsophorylation and differentiation confirming that histone phsophorylation was partly responsible for the decrease in ATP concentrations. It is suggested that the induction of differentiation in HT- 29 cells could be either due to non-specific transcription of genes by activation of a chromatin switch or specific by the activation of signal transduction pathways based on the flux of ATP through the cells. Differential display RT-PCR is probably the most sensitive method that could be used to validate the suggestion of either a nonspecific transcription of genes or a specific differentiation reported for HT-29 cells.
2
Andersson, Kennet. "Effects of Physiological Variations". Thesis, Umeå universitet, Institutionen för matematik och matematisk statistik, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-51310.
Testo completoAbstract (sommario):
Heart ischemia, the precursor to an infarction, is one of the most common diseases in the western world. Today, the electrocardiogram or ECG is the most widely used tool to diagnose the disease. However, it often fails to detect the ischemia or to give an adequate picture of the size and location. Therefore, the potential of increasing knowledge obtained through mathe- matical models is very high. In this thesis the bidomain model is used to describe the electrical activity in the heart and body with ischemia incorporated into the model. To solve the equations set up by the bidomain model, the finite element method is used. Different physiological variations have been made to the body, these include changing the location of the heart and varying the conductivities in the body. The solution to the equations is then studied at the body surface. The main question asked is whether it is possible to detect the location and size of different types of ischemia by analyzing the solution. The methods used for this have been Singular Value Decomposition and Su- pervised learning. The different vectors obtained from the decomposition are used to distinguish the location and size of the ischemia for different physiolog- ical variations. The results show that it is possible to distinguish the location of the ischemia but that it probably will be more difficult to find the correct size since the change in size is harder to separate from other physiological variations, such as the conductivity of the body. Although relatively simple methods have been used, they indicate that, with further development, they can be used for the purpose of detecting the different ischemia.
3
Aiken, Simon Piers. "Physiological transport of zinc". Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278677.
Testo completo
4
Lørup, Lise. "Physiological patterns in pregnancy". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:d14b1507-140e-4647-889f-d6b98237100d.
Testo completoAbstract (sommario):
The Confidential Enquiries into Maternal Deaths in the UK have highlighted an urgent need for development of a national Modified Early Obstetric Warning System (MEOWS) to aid the more timely recognition and treatment of complications in pregnancy. Six vital signs are used to assess the clinical status of women presenting acutely during and immediately after pregnancy: heart rate, oxygen saturation, systolic and diastolic blood pressure, temperature and respiratory rate. In the case of MEOWS, these define the thresholds that determine if a woman requires further medical review. Dynamic changes in maternal vital sign physiology associated with pregnancy complicate the use of vital signs to detect physiological deterioration. These changes are currently poorly described in the literature. The aim of this work is to establish the normal physiological response to pregnancy in low-risk pregnant women, in terms of expected changes in vital signs. Using this knowledge, we will propose the first evidence-based, gestation-specific MEOWS chart. To achieve this, we have set up the Prediction of Physiological Patterns in Pregnancy (4P) study. Using a custom-designed digital health system, healthcare professionals and women self-monitoring at home collect large numbers of vital sign measurements electronically. In particular, as respiratory rate currently is the only vital sign measured manually in routine clinical care, we propose two methods for electronic measurement of respiratory rate: using the in-built accelerometer of a smartphone and using the photoplethysmogram signal output by a pulse oximeter. These methods are validated against the current reference standard derived from a 15-second nurse count of breaths. This thesis uses a dataset of 2,645 sets of vital sign measurements, collected from 439 women during pregnancy, in the 4P study. Using the electronic methods for measurement of respiratory rate, we obtain respiratory rate estimates with a mean absolute error of 2.9 respirations per minute compared to the reference measurement. From these data, we design reference ranges for changes in all six vital signs conditional on gestational age. Using a centile-based approach, we propose gestation-specific thresholds of normality for each vital sign, which will form the basis of a new MEOWS score to alert for physiological deterioration. Defining normality is the first step in recognising abnormality.
5
Laubacher, Timothy Charles. "Physiological measures of presence". The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1407237660.
Testo completo
6
Pratt, David Andrew. "Physiological studies of thrombospondin". Thesis, University of Edinburgh, 1991. http://hdl.handle.net/1842/20119.
Testo completoAbstract (sommario):
Thrombospondin (TSP), a glycoprotein of wide cellular distribution, exhibits several activities important in platelet aggregation, haemostasis and cell adhesion. The aim of this project was to investigate the production and role of TSP in human tissues and fluids; particularly its source in the breast and relation to malignant disease. Most circulating TSP was contained within platelet α-granules and released upon activation of these cells. Infused TSP appeared to be rapidly bound, whilst its clearance from the circulation was relatively slow. Extra-platelet sources contributed substantially to basal plasma levels; platelet-associated TSP may therefore be a better indicator of platelet activation than plasma concentration. TSP concentration in breast cyst fluids varied according to cyst type and correlated inversely with epidermal growth factor. TSP was present in milk at high levels compared with plasma and its pattern of secretion resembled that of IgA; it may be that white cells which infiltrate the mammary gland are a major source of TSP in breast secretions. Very high levels of TSP were found in malignant breast tissue compared with non-malignant breast and were associated with the centre of the tumour mass. Positive correlation between TSP and von Willebrand factor suggested that endothelium contributes to the high levels of both proteins in malignant breast, whereas lack of correlation between TSP and tissue plasminogen activator argued against epithelium being the source of TSP in breast cancer. In conclusion, the results presented in this thesis support current knowledge of TSP as an adhesive glycoprotein of platelets, vessel walls and connective tissues. Novel studies in the breast have revealed a marked association of TSP with cancerous tissue and some cyst fluids, which could be due to production by vascular endothelium and certain white blood cells. Whilst the role of TSP in the breast remains to be defined, its relation to disease states may be of particular physiological significance.
7
Ramsey, Michael W. "Physiological Technology for Coaches". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etsu-works/4105.
Testo completo
8
Schadock, Ines Claudia. "Physiological role of prolylcarboxypeptidase". Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2011. http://dx.doi.org/10.18452/16412.
Testo completoAbstract (sommario):
Prolylcarboxypeptidase (PRCP, EC3.4.16.2) ist ein ubiquitär exprimiertes Enzym, mit höchster Expression im Maushirn. Es spaltet spezifisch die letzte carboxyterminale Aminosäure von Substraten, deren vorletzte Aminosäure ein Prolin ist. Seine bisher publizierten Substrate Angiotensin II (AngII) und alpha Melanocortin Stimulierendes Hormone (alphaMSH) legen eine Rolle von PRCP in der Entwicklung von kardiovaskulären und metabolischen Krankheiten nahe. Um die in vivo Funktion von PRCP zu studieren, wurde eine Knockout Maus generiert (PRCP-/-). Metabolischer Phänotyp: PRCP-/- Mäuse zeigten generell ein reduziertes Körpergewicht, selbst wenn sie über Monate mit einer Hochfettdiät versorgt wurden. Erhöhte Plasmaleptin Werte und Proopiomelanocortin (pomc) Expression in knockout Hypothalami wiesen auf eine wichtige Rolle von PRCP in der Regulation von Futteraufnahme und Energiehomöostase hin. Eines der Genprodukte von pomc ist alphaMSH, welches im Hypothalamus die Futteraufnahme terminiert. Die carboxyterminale Struktur dieses Neuropeptids erfüllt alle Voraussetzungen, um von PRCP gespalten zu werden. Zudem konnte prcp Promotoraktivität in den selben Hirnstrukturen gezeigt werden, in denen auch alphaMSH-Wirkung beschrieben wurde. Eine mögliche Funktion von PRCP wäre somit die Inaktivierung des Appetitzüglers alphaMSH im Hypothalamus. Kardiovasculärer Phänotyp: Zunächst erwiesen sich zirkulierende Ang-Peptide in PRCP-/- Mäusen als unverändert. Jedoch konnte ein erhöhtes Niveau des Degradationsproduktes Ang1-7 in der Niere gezeigt werden. Die Entdeckung einer erhöhten Enzymaktivität von Angiotensin Converting Enzyme 2 (ACE2) in PRCP-/- Nieren, wurde als Kompensation der fehlenden PRCP Aktivität in PRCP-/- Nieren interpretiert. bot einen Erklärungsansatz für dieses Ergebnisse. Es wird davon ausgegangen, daß ACE2 die fehlende PRCP Aktivität in knockout Mäusen kompensiert. Das es sich hierbei um eine lokale begrenzte Kompensation handeln muß, zeigten der erhöhte Blutdruck und Herzrate, sowie die milde Herzhypertrophie. Da spezifische prcp Promotoraktivität in Hirnnuclei gefunden wurde, die in die Kontrolle der Herzfrequenz und des Blutdrucks involviert sind, wird eine regulatorische Funktion von Hirnstamm-PRCP auf Herzrhytmus und Blutdruck vermutet.Prolylcarboxypeptidase (PRCP, EC3.4.16.2) is an enzyme specifically cleaving the last carboxy-terminal amino acid from substrates containing a penultimate proline. Its known potential substrates are linked to cardiovascular and metabolic phenomenon. To analyse the in vivo function of this enzyme a PRCP knockout mouse was generated. Homozygous knockout mice are viable but show tendency of decreased life span. In mice prcp expression is present in all tissues tested with very specific localizations of prcp promotor activity to distinct brain areas within the cortex, hippocampus, hypothalamus and the brain stem. The metabolic phenotype of PRCP deficient mice is characterized by low body weight even when feeding the animals a high fat diet. The increased plasma leptin levels and elevated expression of proopiomelanocortin gene (pomc) found in knockout hypothalami suggests an involvement of PRCP in the regulation of food intake and energy homeostasis. One of the gene products of pomc is alpha-melanocortin stimulating hormone (alphaMSH) that is terminating feeding when released from hypothalamic POMC neurons. Its carboxy-terminal structure is fitting the cleavage preferences of PRCP. Prcp promotor activities are localized in arcuate nucleus and paraventricular nucleus, brain areas of known alphaMSH signalling, supporting a role of PRCP in the degradation of central alphaMSH. The impact of PRCP on angiotensin II (AngII) metabolism was studied by determining the level of AngII and its degradation product Ang1-7 in blood and tissues. But instead of increased AngII levels due to the missing degradation enzyme in knockout mice, Ang1-7 levels were increased in kidney. These results were explainable by the increased activity of angiotensin converting enzyme 2 (ACE2) found in kidney. Probably ACE2 is compensating the lack of PRCP in the knockout mouse. Nevertheless, blood pressure and heart rate of PRCP knockout mice was increased. The mild hypertension was accompanied by mild hypertrophy of the hearts. Prcp promotor activity was found in brain stem an area important for regulation of blood pressure and heart rate suggesting that central PRCP regulates blood pressure.
9
Veluvolu, Kalyana [Verfasser]. "Real-time Filtering of Physiological Tremor for Microsurgery. Physiological Tremor Robotic Compensation / Kalyana Veluvolu". München : GRIN Verlag, 2020. http://d-nb.info/1220832847/34.
Testo completo
10
Carrithers, John A. "Effects of post-exercise carbohydrate-protein feedings on muscle glycogen restoration". Virtual Press, 1999. http://liblink.bsu.edu/uhtbin/catkey/1133741.
Testo completoAbstract (sommario):
The purpose of this investigation was to determine the effects of post-exercise carbohydrate-protein feedings on muscle glycogen restoration following exhaustive cycle ergometer exercise. Seven male collegiate cyclist (age=25.6±3.3y, ht.=180.9±8.5cm, wt.=75.4±10.7kg, VO2max=4.20±0.4 1•miri 1) performed three trials, each separated by -lwk, 1) 100% (x-D glucose (CHO), 2) 70% carbohydrate-20% protein-10% fat (CHOPRO), and 3) 86% carbohdyrate-14% amino acid (CHO-AA). All feedings were eucaloric, based upon 1.0 g•kgb.W.'1•hr"1 of carbohydrate, and administered every half hour during a four hour muscle glycogen restoration period in an 18% wt./vol. solution. Muscle biopsies were obtained immediately and four hours post exercise. Following the exhaustive exercise and every half hour for four hours a blood sample was drawn. Muscle glycogen concentrations increased 53%, 47%, and 57% for the CHO, CHO-PRO, and CHO-AA feedings, respectively, however no differences among the feedings were apparent in muscle glycogen restoration. The plasma glucose and insulin concentrations demonstrated no differences throughout the restoration period among the three feedings. These results suggest that muscle glycogen restoration does not appear to be enhanced with the addition of either protein or amino acids to an eucaloric carbohydrate feeding following an exhaustive cycle exercise. However, it appears that if adequate amounts of carbohydrates are consumed (greater than 0.70 g•kgb,W,."'•hf' carbohydrate) following exhaustive exercise, maximal muscle glycogen restoration occurs.School of Physical Education
11
Elkins, Amanda N. "Physiological compliance during team performance". Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202410308/.
Testo completo
12
O'Neill, Mark. "Cardiovascular regulation under physiological stress". Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294358.
Testo completo
13
Mohan, Ravi Michael. "Cardiac regulation during physiological stress". Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393468.
Testo completo
14
Baker, Jonathan Paul. "Physiological gradients in oral biofilms". Thesis, Cardiff University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582603.
Testo completo
15
Williams, Elizabeth R. "Network contributors to physiological tremor". Thesis, University of Newcastle Upon Tyne, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.500953.
Testo completoAbstract (sommario):
This thesis investigates circuits within the brain and spinal cord that contribute to -10 Hz physiological tremor and slow finger movement discontinuities. Electrophysiological recordings were made from the motor areas of two macaque monkeys trained to perform index finger flexion movements whilst tracking a moving target. We recorded local field potentials and single units from the primary motor cortex (Ml), deep cerebellar nuclei (DCN), pontomedullary reticular formation (PMRF) and the intermediate zone of the spinal cord (SC). Activity for all areas was coherent with finger acceleration at -10 Hz.
16
Drew, P. J. T. "Physiological studies with arginine vasopressin". Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598650.
Testo completo
17
Beltz, John D. "Physiological response to interval training". Virtual Press, 1987. http://liblink.bsu.edu/uhtbin/catkey/486191.
Testo completoAbstract (sommario):
The purpose of this study was to examine the effect of swimming distance and rest interval on the intensity of swimming (relative to VO2 max) and the contributions of the three energy systems (aerobic, anaerobic, and alactic) during these interval sets. Nine male college swimmers performed fourteen different interval training sets. Distances were 25, 50, 100, or 200 yards with rest intervals of 10 seconds, 1, and 3 minutes. During these sets only the distance to be swum and the rest interval for the set was given. No qualitative information from the coach was provided. These interval sets were performed by the swimmers with the influence from timers being kept minimal. Oxygen cost during the swim was determined from the velocity of the swim based on a linear regression for swimming velocity and oxygen uptake for each swimmer. The same interval sets were completed with pace controled where venous blood samples were obtained 1, 3, 5, and 7 minutes after the completion of each training set. 81ood samples were analyzed for lactate accumulation, blood pH, p0.,, pCO2, and hemoglobin. From these values bicarbonate, base excess, and blood oxygen saturation were calculated using equations developed by Siggard-Anderson. The results of this study do indicate that there is a predictable relationship between swimming distance and rest interval on swimming intensity (relative to VO., max). There was a curvilinear L relationship between swimming intensity (relative to VO max) and rest interval for 50, 100, and 200 yard interval sets. The correlation at these distances were r-0.96, 0.93, and 0.94 respectively. There was a linear relationship between intensity and the distance swum for the 10 second, 1, and 3 minute rest intervals. The correlation for these rest intervals were r= 0.99, 0.99, and 1.00 respectively. There was an increase in the relative contribution of aerobic energy as the distance of the swim increased for all three rest intervals. At a given swiming distance there was a greater contribution of non-aerobic energy as the rest interval increased. Contrary to continuous swimming, greater swimming velocity does not directly correspond to greater contributions of anaerobic energy during intermittent swimming. The distance and rest interval during intermittent training greatly effect the relative contributions of the three energy systems. The intensity of the swim and the relative contributions of each energy system should be considered when planning specific training regimens.
18
O'Hagan, C. E. "Physiological catalysts of LDL oxidation". Thesis, Queen's University Belfast, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396887.
Testo completo
19
Creagh, Una B. "Physiological stresses in female orienteering". Thesis, Liverpool John Moores University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319849.
Testo completo
20
Hodgson, Emily. "Physiological variation in crustacean haemocyanins". Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299680.
Testo completo
21
Syed, Zeeshan Hassan 1980. "Computational methods for physiological data". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/54671.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2009.Author is also affiliated with the MIT Dept. of Electrical Engineering and Computer Science. Cataloged from PDF version of thesis.
Includes bibliographical references (p. 177-188).
Large volumes of continuous waveform data are now collected in hospitals. These datasets provide an opportunity to advance medical care, by capturing rare or subtle phenomena associated with specific medical conditions, and by providing fresh insights into disease dynamics over long time scales. We describe how progress in medicine can be accelerated through the use of sophisticated computational methods for the structured analysis of large multi-patient, multi-signal datasets. We propose two new approaches, morphologic variability (MV) and physiological symbolic analysis, for the analysis of continuous long-term signals. MV studies subtle micro-level variations in the shape of physiological signals over long periods. These variations, which are often widely considered to be noise, can contain important information about the state of the underlying system. Symbolic analysis studies the macro-level information in signals by abstracting them into symbolic sequences. Converting continuous waveforms into symbolic sequences facilitates the development of efficient algorithms to discover high risk patterns and patients who are outliers in a population. We apply our methods to the clinical challenge of identifying patients at high risk of cardiovascular mortality (almost 30% of all deaths worldwide each year). When evaluated on ECG data from over 4,500 patients, high MV was strongly associated with both cardiovascular death and sudden cardiac death. MV was a better predictor of these events than other ECG-based metrics. Furthermore, these results were independent of information in echocardiography, clinical characteristics, and biomarkers.
(cont.) Our symbolic analysis techniques also identified groups of patients exhibiting a varying risk of adverse outcomes. One group, with a particular set of symbolic characteristics, showed a 23 fold increased risk of death in the months following a mild heart attack, while another exhibited a 5 fold increased risk of future heart attacks.
by Zeeshan Hassan Syed.
Ph.D.
22
Wäsle, Barbara. "The physiological function of syncollin". Thesis, University of Cambridge, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.615785.
Testo completo
23
Bridge, Craig. "Physiological demands of competitive Taekwondo". Thesis, Edge Hill University, 2011. http://repository.edgehill.ac.uk/6165/.
Testo completoAbstract (sommario):
Taekwondo has evolved from a traditional martial art into a modern-day Olympic combat sport. Despite this transition, knowledge of the physiological demands of this combat sport is in its infancy. This thesis investigates the physiological demands of competitive Taekwondo using experienced male international Taekwondo competitors. Physiological measures and activity profile information were initially collected in championship Taekwondo competition to determine the fundamental physiological demands of this combat sport. The activity profile of championship Taekwondo combat elicited near-maximal heart rate (HR) responses and high blood lactate concentrations. The activity levels and physiological responses (e.g. HR and blood lactate) increased significantly between round 1 and 3 of combat. These data collectively suggest that the activity pattern of Taekwondo combat imposes high aerobic and anaerobic demands on the competitors, and these energetic requirements are increased as the rounds progress. The activity profile in championship combat was also modulated by a competitor’s weight division. Most notably, the data highlighted a predominance of fighting activity for heavy weights, and longer preparatory actions and less frequent fighting exchanges for feather weights. A Taekwondo competition simulation was devised and implemented to examine the physiological and hormonal responses to Taekwondo combat in simulated and championship settings. The championship Taekwondo combats elevated the physiological (e.g. HR, plasma lactate, glucose and glycerol) and hormonal responses (e.g. plasma adrenaline and noradrenaline) in comparison to simulated combats performed in a controlled setting. These divergent responses were evident even though both combat settings exhibited comparable activity profiles. This suggests that the contrasting physiological and hormonal responses were mediated by the stress responses to fighting in championship events. The physiological and hormonal responses to performing successive Taekwondo combats were examined during a simulated championship event. Performing four combats in an ecologically valid competition time-structure modulated the physiological and hormonal responses to combat and perturbed homeostasis between the combats. Most notably, the successive combats resulted in reduced plasma noradrenaline and lactate responses to combat and increased HR responses earlier in combat. These responses may reflect a change in the activity of the competitors’ and/or altered metabolic function in favour of an increased reliance on aerobic metabolism and diminished anaerobic energy yield as the combats are repeated. Importantly, the HR and plasma concentrations II of glycerol, NEFA and lactate remained elevated above baseline levels between a number of the repeated combats. This suggests that the recovery processes were often incomplete between the combats. The collective findings of these investigations demonstrate that Taekwondo is an intermittent combat sport that elicits high demands upon both aerobic and anaerobic metabolism. The physiological requirements of Taekwondo combat may be regulated by a multitude of competition factors including a competitor’s weight division, the round of combat and performing successive combats with different recovery intervals. Taekwondo combat also activates the sympathetic-adrenal-medulla promoting the release of stress hormones (catecholamines) into the circulation. The stress-hormonal responses are mediated by the specific combat environment and the requirement to perform repeated combats within a single day. These original findings may serve as a valuable ergonomic framework to prepare competitors’ for the specific requirements of Taekwondo competition.
24
Tivey, Hannah S. E. "Physiological responses to genomic instability". Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/54394/.
Testo completoAbstract (sommario):
Abnormalities in the cellular senescence programme may contribute to premature ageing and cancer predisposition. Primary human cells have a limited proliferative capacity, entering a state of irreversible growth arrest/senescence arising from telomere attrition (replicative senescence). Stress-induced premature senescence (SIPS) can additionally limit cellular lifespan and there are several human genomic instability (Gl) disorders—cancer-prone/premature ageing syndromes—in which SIPS may prematurely limit cellular lifespan. The hypothesis is that increased Gl is a critical factor in limiting the lifespan of somatic cells by activating common pathways leading to SIPS. This study examines the extent to which Gl cells present restraints on cellular proliferation with a focus on the degree to which they share similar properties—not least a common dependence on the p38 mitogen-activated protein kinase (MAPK) mediated stress response pathway. The study utilised a panel of normal (N) and a Gl panel of fibroblasts comprising: Rothmund Thomson syndrome (RTS), Bloom syndrome (BS), Cockayne syndrome A (CSA), Hutchinson-Gilford Progeria syndrome (HGPS), Nijmegen Breakage syndrome (NBS), Werner syndrome (WS), Seckel syndrome (SS), Dyskeratosis Congenita (DKC) and Ligase 4 syndrome (LIG4). The study revealed a commonality of response to p38 inhibitors—increased clonogenicity and lifespan—for normal and Gl syndrome cells, suggesting that all cells undergo some degree of p38-mediated proliferation restraint/SIPS. A degree of inter-strain heterogeneity for reduced replicative potential and/or altered morphology was apparent for both normal and Gl syndrome primary fibroblasts. This study revealed truncated lifespans for LIG4, SS, HGPS, BS, RTS, DKC and NBS cells. GM18366(SS) and GM07166(NBS) cell strains show an altered morphology and increased p38 inhibitor responses suggesting elevated SIPS operation. Growth and DNA damage studies using a newly created bank of hTert-immortalised cell strains AG16409(N), AG18371(RTS), GM02548(BS), GM07166(NBS), GM01856(CSA), AG11498(HGPS) and GM17523(LIG4) showed that Gl syndrome cells, alleviated from the stress of telomere attrition, remain susceptible to SIPS. Of these RTS cells were hTert-immortalised for the first time, showing that senescence in these strains is telomere-dependent. Cell cycle analysis revealed a common p38- associated mechanism that limits retention in cycle. The specific p38 inhibitor BIRB796 was found to increase clonogenic potential of both normal and Gl syndrome cells. The findings suggest that both RTS and WS cells show a higher proportion of cells that are non-dividing. Furthermore, the study suggests that WS cells have an altered cell cycle transit time that is reduced by BIRB796 treatment. Overall, the study highlights successful single cell analysis approaches for testing the impact of p38 inhibitors by teasing out the nature of cellular heterogeneity arising from different sources for specific cell strains. These findings support and expand previous evidence that WS cells undergo higher levels of SIPS compared to normal cells and provide new evidence that RTS cells may also show an increased propensity for SIPS.
25
McGuinness, Kevin. "Cough detection. a physiological approach". Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.528494.
Testo completo
26
Guazzi, Alessandro. "Revealing physiological changes through colour". Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:9f3dd3e1-ca10-4bdb-aff5-370daa1b0e7a.
Testo completoAbstract (sommario):
This dissertation extends remote vital sign monitoring by examining whether it is possible to track oxygen saturation with visible-light video cameras by filming an exposed skin region (the face). Two further questions are also investigated as part of the presentation of this thesis: the in uence of skin melanin on the ability of video cameras to track oxygen saturation, and the ability of video cameras to assess the absolute value of oxygen saturation at any given point in time. A study involving human volunteers was designed to answer these research questions in a controlled environment, and 46 subjects were recruited. The subjects were divided into six different skin phenotype groups (Fitzpatrick Scale I{VI). For a period of up to one hour, the volunteers' oxygen saturation was varied between 80% and 100% and videos of their faces were recorded in that time. The volunteers' reference oxygen saturation was recorded using two pulse oximeters placed on the index fingers of each hand. Another study was carried out in a neonatal high-dependency unit to test the algorithms for remote vital sign monitoring in a challenging clinical setting. A theoretical basis for the derivation of oxygen saturation monitoring algorithms is developed throughout the dissertation, and two methods (baseline and RoR) were built upon this. The baseline method has parallels with oximetry and is based on tracking overall changes in the colour of the skin while minimising the effect of lighting, while the RoR method mimics pulse oximetry in form and assesses the relative change in amplitude as measured by each colour channel while oxygen saturation changes. Both methods are found to work well for subjects of Fitzpatrick phenotypes I{IV (average coeficient of determination r2 of 0.79 and 0.71 for baseline and RoR respectively across all Type I{IV subjects), variably for Type V subjects (average r2 values of 0.64 and 0.48), and not work for Type VI subjects (average r2 values of 0.19 and 0.01). Although the RoR method yields noisier results than the baseline method, it was found that the timecourse of the latter varied with respect to the oxygen saturation. A simple linear model used to derive oxygen saturation directly from the video camera data was thus devised using the RoR method only, and applied to Type I{V subjects. The subjects were divided into randomly generated but equally split training sets and test sets and the model parameters learned from the training set were evaluated in the test set. This was repeated over 10 iterations and the overall mean absolute error between the estimated oxygen saturation using the video camera data and the reference oxygen saturation using the pulse oximeters was, for Type I{V subjects respectively: 3.0%, 2.3%, 2.5%, 2.5%, and 4.6%.
27
Neal, Jeremy L. "Physiological Factors Influencing Labor Length". The Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=osu1218220309.
Testo completo
28
Gibb, Gregory Donald. "Physiological regulation of Streptomycete Proteases /". The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487327695620921.
Testo completo
29
Kessler, Jeffrey C. (Jeffrey Charles). "Physiological Effects of Monetary Consequences". Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc278141/.
Testo completoAbstract (sommario):
Electrodermal responding (EDR) and heart rate (HR) were assessed for seven subjects participating in a reaction time task consequated with monetary bonuses (250, 100, and 10), monetary penalties (250,100, and 10), and a monetary neutral value (00). Unlike previous research employing group designs and a tonic measure (i.e., mean over long periods of time), this study utilized a single-subject design and a phasic measure (i.e., mean over 2-s intervals). Heart rate data was too variable for meaningful analysis. EDR data showed that the peak levels of EDR were higher for penalties than for the corresponding values of bonuses (e.g., -250 vs. +250) for most subjects. Similarly, peak levels of EDR were generally higher during sessions in which consequences were presented than in sessions during which consequences were absent.
30
Matsumoto, Hitoshi. "Physiological Effects of Blackcurrant Anthocyanins". Kyoto University, 2003. http://hdl.handle.net/2433/149024.
Testo completo
31
Tahk, Samuel H. "The physiological role of PIASy". Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1619606731&sid=4&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Testo completo
32
Nourbakhsh, Nargess. "Multimodal Physiological Cognitive Load Measurement". Thesis, The University of Sydney, 2015. http://hdl.handle.net/2123/14294.
Testo completoAbstract (sommario):
Monitoring users’ cognitive load in real-time allows the system to adjust its interface and improve the interaction experience and user performance. Physiological signals are relatively reliable, real-time measures of cognitive load. Measurement robustness can be improved by taking account of confounding factors, and multimodality has the potential to enhance mental load prediction. This thesis investigates cognitive load measurement by means of physiological data and machine learning techniques. Skin response and eye blink are economical, conveniently-captured physiological measures that were studied. Multiple datasets were used to increase the reliability of the results which confirmed that the explored features can significantly measure different cognitive load levels. Confounding factors can distort cognitive load measurement results. Emotional fluctuations have profound impacts on physiological signals. Therefore to examine the robustness of the explored features, they were evaluated for cognitive load measurement with affective interference in different datasets. The results showed that they can measure multiple cognitive load levels with high accuracy even under emotional changes. Different modalities can impart complementary information. Hence we tried to improve the accuracy by means of multimodal cognitive load measurement. Two fusion techniques were used and different combinations of classifiers and features were examined. Multimodality proved to improve the cognitive load classification accuracy and the studied feature fusions performed well both in the absence and presence of affective stimuli. This thesis proposes frameworks for monitoring cognitive load using physiological data and machine learning techniques. The system was tested during affective fluctuations and modality fusion was performed. The outcomes of this research show that the explored features and methods could be used as means for objective, robust, accurate cognitive load measurement.
33
Hogan, Kyla B. "The hemostatic responses to exercise in hot and cold temperatures". Virtual Press, 2008. http://liblink.bsu.edu/uhtbin/catkey/1398717.
Testo completoAbstract (sommario):
Purpose: The impact of temperature on the coagulative response to exercise has not been well described. The purpose of this study was to assess the response of plasma thrombin-antithrombin (TAT) to exercise during exposure to both hot and cold temperatures, and to compare those responses to exercise under normal, temperate conditions. Methods: Fifteen healthy male subjects (25.3 + 4.3 years) volunteered to participate in this study. Subjects completed maximal cycle ergometer exercise tests in three different temperatures (20°C, 5° or 8° C, and 30°C) in an environmental chamber. All tests were conducted in random order and separated by at least seven days. Blood samples were obtained before and immediately after exercise and analyzed by Elisa to determine plasma concentrations of thrombin-antithrombin complex (TAT). Results: Subjects demonstrated significantly elevated plasma levels of TAT in all three temperatures immediately after exercise (normal =1.04 ± 0.44 ng/ml, cold =1.34 ± 0.79 ng/ml, hot =1.18 + 0.95 ng/ml) when compared to baseline measures (normal = 0.45 ± 0.26 ng/ml, cold = 0.88 + 0.57 ng/ml, hot = 0.64 + g/ml). Subjects also showed significant elevations in TAT concentrations both before and after exercise in the cold temperature when compared with the normal temperature. There was no significant difference between the hot and normal temperatures. Conclusion: An individual's coagulation potential is increased following maximal physical exertion and may be further increased by exposure to colder temperature. Key Words: coagulation, physical exertion, temperature, thrombosis.School of Physical Education, Sport, and Exercise Science
34
Gohil, Risha. "Short term physiological changes secondary to exercise in intermittent claudication : short term physiological changes in claudication". Thesis, University of Hull, 2013. http://hydra.hull.ac.uk/resources/hull:10090.
Testo completoAbstract (sommario):
Background: In patients with intermittent claudication (IC), supervised exercise programmes (SEP) improve walking distance and quality of life (QoL); however the mechanisms by which these benefits are achieved remain unclear. Endothelial dysfunction is recognised as a trigger of the atheroinflammatory cascade and subsequent cardiovascular disease. In health, training improves cardiorespiratory physiology, inflammation and endothelial function. Changes in cardiorespiratory physiology, inflammatory markers and endothelial function are contradictory in IC. Objectives: This thesis aimed to assess the impact of SEP on cardiopulmonary physiology, endothelial function and athero-inflammatory markers in patients with IC. Methods: Following local research ethics committee and R & D approval, patients with IC were recruited from outpatient clinic. After providing informed written consent, patients underwent baseline assessment on two separate days. Session 1: participants completed a constant load treadmill test with pre and post exercise ankle brachial pressure indices. Session 2: measured QoL, endothelial function (EndoPAT2000, Itamar, Israel), venepuncture and a cardiopulmonary exercise test (CPET) using cycle ergometry. Participants then underwent a 12 week period of SEP which consisted of circuit training, with re-assessments at six and twelve weeks. The primary outcome measure was a 1.5ml/kg/min improvement in peak VO₂ after six weeks of exercise. Secondary outcomes included changes in endothelial function, quality of life, walking distance and inflammatory markers at both six and twelve weeks. Results: No significant improvements in CPET measurements, endothelial function or inflammation were demonstrated at any time point. Traditional markers of walking ability and QoL demonstrated an improvement by 12 weeks. Conclusions: The underlying mechanism through which exercise improves walking distance remains un-identified. Further work regarding the changes at the cellular level within the muscle is of importance.
35
Young, Ingrid Victoria. "The energy demands of a 2,000 meter race simulation for national level oarswomen". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28542.
Testo completoAbstract (sommario):
The purpose of this study was to assess the energy demands of a 2,000 meter race simulation (RS) for national level oarswomen; as evaluated on a rowing ergometer (RE). A Progressive Intensity Test (P.I.T.) was also performed on the RE to further evaluate the RS. Six national level oarswomen (X values: age= 24.5 yrs., ht= 179 cm, wt= 75 kg), all current national team candidates (1988), participated in this investigation. A 6 1/2 minute tape recorded water race was used to execute a 2,000 meter RS on a Dr. Gjessing Ergorow ergometer. The tape recording was an actual race tape that was respliced to last exactly 6 1/2 minutes. Metabolic and respiratory exchange variables were continuously monitored by an open circuit method, utilizing a Beckman Metabolic Measurement Cart interfaced on-line with a Hewlitt Packard 3052A data acquisition system. The energy demands were calculated from metabolic variables, total oxygen cost and the analysis of excess post-exercise oxygen consumption (recovery V0₂).Results indicated a mean V0₂max. of 3.85 1.min⁻¹ , mean net V0₂ of 24.48 1 and a mean recovery V0₂ of 4.92 1. This represented the aerobic cost of the event at approximately 80% or 4/5ths of the total energy cost while the anaerobic contribution was approximately 20% of l/5th of the total energy cost. During the RS, V0₂ values rapidly increased to 90% of mean V0₂max. (3.85 l.min⁻¹) in the first two minutes. Mean max. VE (BTPS) RS value was 122.4 1.min⁻¹. VE plateaued after two minutes and remained around 90% of P.I.T. mean max. VE for the final 4 1/2 minutes. Mean max. excess C0₂ for RS was 19.81 ml.kg⁻¹.min⁻¹. The average maximal heart rate, as recorded in the RS was 192.8 bpm. The results of this study indicate the high aerobic demands and tremendous exercise intensity involved in the 2,000 meter RS.Education, Faculty of
Curriculum and Pedagogy (EDCP), Department of
Graduate
36
Anderson, Dawn E. "Effects of caffeine on the metabolic and catecholamine responses to exercise in 5 and 28p0sC environments". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/833465.
Testo completoAbstract (sommario):
The influence of caffeine on the metabolic and catecholamine responses to mild exercise in a cold and a warm environment was studied in eight healthy males. The subjects performed 60 minutes of cycling at 50% VO2max in a cold environment (5°C and 70% relative humidity) and a warm environment (28°C and 50% relative humidity) 30 minutes after ingesting caffeine (5mg/kg body weight) or placebo (dextrose). Caffeine ingestion prior to exercise in the warm environment resulted in increased plasma epinephrine, with no effect on plasma norepinephrine. Neither lipid nor carbohydrate metabolism was altered by caffeine in the warm trial. Exercise in the cold environment (placebo) produced increased oxygen consumption and carbohydrate metabolism, decreased lipid metabolism, and no difference in plasma catecholamines compared with the warm-placebo trial. Responses to the combination of caffeine ingestion and the cold environment did not differ from cold-placebo responses in oxygen consumption or respiratory exchange ratio during the cycling bout. However, in the cold-caffeine trial plasma epinephrine was elevated. In addition, fat oxidation, serum free fatty acids, and serum glycerol were elevated in the cold-caffeine condition. Carbohydrate oxidation was depressed, while serum glucose and blood lactate were elevated in this trial. The results of this study indicate that caffeine increases plasma epinephrine; cold increases oxygen consumption and carbohydrate metabolism, while decreasing lipid metabolism; and the combination of caffeine and cold during exercise increases plasma epinephrine and lipid metabolism, but decreases carbohydrate metabolism.Human Performance Laboratory
37
Kerr, Chadwick G. "Hypothermia during Olympic triathlon : influence of body heat storage during the swimming stage". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1014852.
Testo completoAbstract (sommario):
The purpose of this study was to determine if mild heat stress induced by wearing a wet suit while swimming in relatively warm water (25.4 ± 0.1°C) increases the risk of heat injury during the subsequent cycling and running stages. Specificlly, during an Olympic distance triathlon in a hot and humid environment (32°C & 65% RH). Five male triathletes randomly completed two simulated triathlons (Swim=30 min; Bike=40 km; Run=10 km) in the laboratory using a swimming flume, cycle ergometer, and running treadmill. In both trials, all conditions were identical, except for the swimming portion in which a full length, sleeveless neoprene wet suit was worn during one trial (WS) and a competitive brief swimming suit during the other (SS). The swim portion consisted of a 30 min standardized swim in which oxygen consumption (V02) was replicated, regardless of WS or SS. During the cycling and running stages, however, the subjects were asked to complete the distances as fast as possible. Core Temperature (T) was not significantly different between the SS and WS trials at any time point during the triathlon. However, mean skin temperature (TSk) and mean body temperature (Tb) were higher (p<0.05) in the WS at 15 (TSk=+4.1°C, Tb=+1.5°C) and 30 min (TSk=+4°C, Tb=+1.6°C) of the swim. These TSk and Tb differences were eliminated by 15 min of the cycling stage and remained similar (p>0.05) through the end of the triathlon. Moreover, there were no differences (p>0.05) in V02, heart rate (HR), rating of perceived exertion (RPE), or thermal sensation (TS) between the WS and SS. Additionally, no significant differences were found in cycling (SS=1:14:46 ± 2:48 vs. WS=1:14:37 ± 2:54 min), running (SS=55:40 ± 1:49 vs. WS=57:20 ± 4:00 min) or total triathlon times (SS=2:40:26 ± 1:58 vs. WS=2:41:57 ± 1:37 min). Therefore, the primary finding was that wearing a wet suit during the swimming stage of an Olympic distance triathlon in 25.4°C water does not adversely affect the thermal responses or the triathlete's ability to perform on the subsequent cycling and running stages.School of Physical Education
38
Martin, David E. "The effect of heat stress on excess post exercise oxygen consumption". Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834623.
Testo completoAbstract (sommario):
While a great deal of research has been directed towards the phenomena of excess post exercise oxygen consumption (EPOC), the effect of thermal stress on EPOC is not well defined. To assess the effect of heat stress on EPOC, seven healthy, active subjects (4 female, 3 male; 23.9 ± 2.0 years of age) performed 4 trials: one control (quiet rest) and one exercise (45 minutes of cycling at 65% VO2max workload) trial in moderate (23° C, 50% humidity) and hot (35° C, 50% humidity) environments. Oxygen consumption (V02), heart rate (HR) and rectal temperature (RT) were assessed pre, during and post control or exercise. Subjects were monitored until post exercise VO2 had returned to within ±2% of baseline. EPOC was determined by subtracting baseline VO2 from total V02 during the post exercise period. During the first 15 minutes (acute) post exercise, a significant EPOC (p = 0.0019) was seen in both exercise conditions over both control conditions. During the slow phase (> 15 minutes post exercise to baseline), there was no significant difference between the hot control (HC), moderate exercise (ME), or hot exercise (HE) EPOC. Total time post exercise until baseline was achieved was 35, 44, and 51 minutes for HC, ME, and HE respectively. HR was significantly elevated in both exercise conditions. During the acute post exercise period, HR in HE was elevated above MC, ME and HC (p < 0.05). RT was elevated in both exercise conditions during and post exercise. The present data indicate that heat stress does not have a significant effect on the magnitude or duration of EPOC.School of Physical Education
39
Shi, Xiaocai. "Effect of sodium and water intake on plasma aldosterone during prolonged exercise in warm environment". Virtual Press, 1990. http://liblink.bsu.edu/uhtbin/catkey/722232.
Testo completoAbstract (sommario):
Eight well-trained male and female cyclists were studied to determine the effect of sodium and/or water intake on plasma aldosterone during six hours of cycling (55% VO2max) in a warm environment (Tdb = 350C WBGT = 30°C). Each subject randomly completed three trials (water = W; saline = S and no fluid = NF) at one week intervals. Venous blood samples were obtained before dehydration, at 2, 4, 5 and 6 hours during exercise, and also after dehydration. Plasma samples were analyzed for hemoglobin, sodium, potassium, aldosterone and osmolality. Sweat and urine samples were also collected and analyzed for sodium content. Plasma volume based on hemoglobin decreased significantly ( P < 0.01 ) at 15 min in all three trials (Trial W = -7.6%±1.12%; Trial S = -8.6%±1.42% and Trial NF = -6.7%±0.88%) and continued to decrease significantly in Trial NF during exercise ( -10.99% ± 1.3% at the 2th hr; -15.5% ±1.3% at the 4th hr and -16.8%±1.32% at the 5th hr).No significant differences were found betwee trials. Plasma sodium concentration [Na+] decreased over time in Trials W and S and increased in Trial NF due to plasma volume loss. Significant differences in [ Na+ ] were found between Trial NF and Trials W or S. Plasma sodium [Na+ ] adjusted by plasma volume change decreased significantly at 2 hours ( P < 0.01) in the three trials. Average total sodium content of plasma decreased by 125.9 mEq during Trial S, 223.1 mEq during Trial W and 147.1 mEq during Trial NF. Plasma potassium increased significantly (P < 0.01) at 2 hours in all three trials. Plasma osmolality increased significantly (P < 0.01) during prolonged exercise (Trial W = 287.1±2.4 mEq/l; Trial S = 289.4±1.17 mEq/1 and Trial NF = 306±1.6 mEq/1). No significant differences were found between Trials W and S although osmolality was lower in Trial W than in Trial S. A significant difference in osmolality was obtained between Trial NF and Trials W and S (P < 0.01). Plasma aldosterone increased significantly (P < 0.01) during exercise and decreased after exercise. No significant differences existed between Trials W and S although aldosterone levels were lower in Trial S than in Trial W. However, a significant difference was found between Trial NF and Trials W or S. The results of this study suggest that plasma aldosterone has an inverse relationship with plasma volume changes and total sodium concentrations. An increase in plasma potassium and a decrease in plasma sodium during prolonged exercise in a warm environment significantly enhanced plasma aldosterone concentration. The intake of water significantly decreased plasma aldosterone during prolonged exercise in a warm environment, but the intake of sodium had no significant effect in this study.School of Physical Education
40
Macvanin, Mirjana. "The Physiological Cost of Antibiotic Resistance". Doctoral thesis, Uppsala University, Department of Cell and Molecular Biology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3761.
Testo completoAbstract (sommario):
Becoming antibiotic resistant is often associated with fitness costs for the resistant bacteria. This is seen as a loss of competitiveness against the antibiotic-sensitive wild-type in an antibiotic-free environment. In this study, the physiological alterations associated with fitness cost of antibiotic resistance in vitro (in the laboratory medium), and in vivo (in a mouse infection model), are identified in the model system of fusidic acid resistant (FusR) Salmonella enterica serovar Typhimurium.
FusR mutants have mutations in fusA, the gene that encodes translation elongation factor G (EF-G). FusR EF-G has a slow rate of regeneration of active EF-G·GTP off the ribosome, resulting in a slow rate of protein synthesis. The low fitness of FusR mutants in vitro, and in vivo, can be explained in part by a slow rate of protein synthesis and resulting slow growth. However, some FusR mutants with normal rates of protein synthesis still suffer from reduced fitness in vivo. We observed that FusR mutants have perturbed levels of the global regulatory molecule ppGpp. One consequence of this is an inefficient induction of RpoS, a regulator of general stress reponse and an important virulence factor for Salmonella. In addition, we found that FusR mutants have reduced amounts of heme, a co-factor of catalases and cytochromes. As a consequence of the heme defect, FusR mutants have a reduced ability to withstand oxidative stress and a low rate of aerobic respiration.
The pleiotropic phenotypes of FusR mutants suggest that antibiotic resistance can be associated with broad changes in bacterial physiology. Knowledge of physiological alterations that reduce the fitness of antibiotic-resistant mutants can be useful in identifying novel targets for antimicrobial agents. Drugs that alter the levels of global transcriptional regulators such as ppGpp or RpoS deserve attention as potential antimicrobial agents. Finally, the observation that FusR mutants have increased sensitivity to several unrelated classes of antibiotics suggests that the identification of physiological cost of resistance can help in optimizing treatment of resistant bacterial populations.
41
Schroeder, Andreas. "Software engineering perspectives on physiological computing". Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-139294.
Testo completo
42
Nilsson, Björn. "Physiological Aberrations in Patients with Schizophrenia". Doctoral thesis, Uppsala universitet, Institutionen för neurovetenskap, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-9521.
Testo completoAbstract (sommario):
In schizophrenia, subtle aberrations in the brain cause functional disturbances like psychotic symptoms and social disability. There are, however, also disturbances outside the CNS indicating a systemic manifestation in the disease. The aim of the present thesis was to gain deeper understanding of the pathophysiological mechanisms underlying schizophrenia with a particular interest in peripheral and systemic manifestations with relevance for the increased risk of obesity and metabolic complications seen in the disease. Therefore, resting energy expenditure (REE), physical capacity, and relevant body composition variables were measured in patients with schizophrenia and in healthy controls. Also niacin skin flush response and electrodermal activity (EDA) were studied. Patients with schizophrenia exhibited significantly lower REE expressed as kJ/kg, and also lower values compared with predicted levels than the controls. The difference could not be attributed to medication or variations in body composition between the two groups. There was a gender difference with the lowest levels found in male patients. Male patients exhibited significantly lower physical capacity in terms of predicted maximal oxygen uptake capacity and faster increase in respiratory quotient than male controls. The oral niacin test revealed a significantly delayed skin flush reaction in patients compared with controls. The patients also exhibited lower EDA response. There was a significant association in response patterns for the niacin and the EDA tests in the patients, but not in controls. In a test-retest study in patients there was acceptable stability for EDA measures but low test-retest stability for niacin variables. The previously found association in responses for the two tests was, however, replicated. The results gain support for the concept of schizophrenia as a disease with systemic manifestations including metabolic dysregulation. The findings add to the understanding of the weight gain and the increased risk for cardiovascular morbidity seen in this condition.
43
Cole, Simon John. "Physiological studies in irritable bowel syndrome". Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408422.
Testo completo
44
Nelson, Paul Christian. "Physiological correlates of temporal envelope perception". Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2006. http://proquest.umi.com/login?COPT=REJTPTU0NWQmSU5UPTAmVkVSPTI=&clientId=3739.
Testo completo
45
Mačvanin, Mirjana. "The physiological cost of antibiotic resistance /". Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-3761.
Testo completo
46
Chen, Jianhe. "Some physiological studies of Fusobacterium nucleatum /". Title page, summary and contents only, 1994. http://web4.library.adelaide.edu.au/theses/09DSM/09dsmc518.pdf.
Testo completo
47
Ryder, Kelsey. "Influence of media on physiological arousal". [Ames, Iowa : Iowa State University], 2008.
Cerca il testo completo
48
Hellgren, Charlotte. "Physiological Stress Reactivity in Late Pregnancy". Doctoral thesis, Uppsala universitet, Obstetrik & gynekologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-197441.
Testo completoAbstract (sommario):
During pregnancy, the basal activity is increased in both of our major stress response systems: the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis. At the same time, the reactivity towards stressors is reduced. These alterations sustain maternal and fetal homeostasis, and are involved in the regulation of gestational length. Although the feto-placental hormone synthesis produces the main endocrinological changes, also the central nervous system undergoes adaptation. Together, these profound adjustments have been suggested to make women’s mental health more vulnerable during pregnancy and postpartum period. The aim of this thesis was to examine factors connected to physiological stress responses during the late pregnancy in relation to pain, labour onset, emotional reactivity, and mental health. The first study examined the pain and sympathetic response during cold stress, in relation to time to delivery. Women with fewer days to spontaneous delivery had lower sympathetic reactivity, while no pain measure was associated with time to delivery. In the second study, acoustic startle response modulation was employed to study emotional reactivity during late gestation, and at four to six weeks postpartum. The startle response was measured by eye-blink electromyography, while the participants watched pleasant and unpleasant pictures, and positive and negative anticipation stimuli. A significant reduction in startle modulation by anticipation was found during the postpartum assessment. However, no startle modulation by pleasant, or unpleasant, pictures was detected at either time-point. The serum level of allopregnanolone, a neurosteroid implied in pregnancy-induced hyporeactivity, was analysed in relation to self-reported symptoms of anxiety and depression. Although the participants reported low levels of depression, the women with the highest depression scores had significantly lower levels of serum allopregnanolone. There was no correlation between allopregnanolone and anxiety scores. In the fourth study, the cortisol awakening response was compared between women with depression during pregnancy, women with depression prior to pregnancy, and women who had never suffered from depression. No group differences in cortisol awakening response during late pregnancy were found. The results are in line with the previously described pregnancy-induced hyporesponsiveness, and add to the knowledge on maternal stress hyporeactivity, gestational length, and maternal mental health.
49
Horowitz, Melissa. "Physiological profile of Montreal fire fighters". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60074.
Testo completoAbstract (sommario):
The purpose was to compare the physical fitness level of male fire fighters to the average Canadian population of similar age and sex. Subjects were 1303 fire fighters between the ages of 19 and 58 years, categorized into the following four age groups: 19-29 years (n = 351), 30-39 years (n = 408), 40-49 years (n = 408) and 50-59 years (n = 136). Subjects participated in the Canadian Standardized Test of Fitness including (1) pre-test screening; (2) anthropometric; (3) cardiovascular; (4) flexibility and; (5) muscular endurance measurements. It was hypothesized that there would be no significant differences between the body composition, flexibility, cardiovascular fitness and muscular endurance levels of fire fighters compared to the average Canadian of similar age. Fire fighters had significantly lower VO$ sb2$max values and significantly greater scores for sit-ups, push-ups and flexibility for all age categories, compared to their counterparts. The fire fighters' lower aerobic capacity was attributed to elevated body mass and possible long-term effects of exposure to carbon monoxide and vapours from combustible chemicals.
50
Gladman, Marc Antony. "Rectal hypersensitivity : clinical and physiological studies". Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420797.
Testo completo