To see the other types of publications on this topic, follow the link: Anatomy and physiology of the skin.
Dissertations / Theses on the topic 'Anatomy and physiology of the skin'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Anatomy and physiology of the skin.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Chou, Kuang-Yi. "Sodium channel regulatory mechanisms : current fluctuation analysis on frog skin epithelium." Doctoral thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/27148.
Full textAbstract:
This project examined the role of the cytoskeleton in regulatory mechanisms of the amiloride-sensitive Na⁺ channels in isolated frog skin epithelium. The epithelium from ventral frog skin is a model tissue which has proved significant in our understanding of the basic principles involved in water and Na⁺ homeostasis. In particular, this project examines ways in which local (non-hormonal) and hormonal regulatory mechanisms adjust the Na⁺ permeability of apical membranes of frog skin epithelium. Both mechanisms contain factors that are known to increase the apical membrane Na⁺ permeability mainly by increases in the number of open channels. The origin of these new open channels is unknown but, it is postulated that they could arise either by activation of quiescent channels already present in the apical membrane, or by recruitment of channels from cytoplasmic stores. Regarding the latter hypothesis, we also examined the idea that the cytoskeleton might somehow be involved in the insertion of Na⁺ channels within vesicles, into the apical membrane. This is based on the fact that the cytoskeleton is involved in a similar mechanism whereby, in the toad urinary bladder, anti-diuretic hormone (ADH) causes the insertion of aggregates with water channels. Much current interest focuses on the role of the cytoskeleton in the regulation of epithelial Na⁺ channels. To test this hypothesis, we used noise analysis to examine the effects of disrupting the cytoskeleton, on two different mechanisms which bring about changes in open channel densities. The mechanisms are: (1) lowering mucosal Na⁺ concentration (non-hormonal), and (2) addition of arginine-vasopressin (A VP) (hormonal). Non-hormonal, autoregulatory changes in apical membrane Na⁺ conductance were examined by investigating the effects of reducing the mucosal Na⁺ concentration. Our results showed that lowering the mucosal Na⁺ concentration induced large increases in the open channel density in order to stabilise the transport rate. In addition, we observed an average 55-60% increase in the open channel probability, which implies that in epithelium from Rana fuscigula, changes of channel open probability are also an important mechanism in the autoregulation of channel densities in response to a reduction in mucosal Na⁺. The hormonal control of Na⁺ channels by A VP has been intensively studied by noise analysis and the patch clamp. Our results confirmed previous reports that A VP increases the Na⁺ transport rate by increasing the number of open Na⁺ channels, primarily through large changes in the total number of channels, without a significant change in open probability. Regarding the role of the cytoskeleton in regulation of Na⁺ channels and/or its possible role in control of inserting putative vesicles with Na⁺ channels, we studied the effects of disrupting the cytoskeleton on the two regulatory mechanisms. Disrupting microtubules with colchicine had no, or very little effect on either of the regulatory mechanisms. On the other hand, the integrity of the microfilaments was very important for the autoregulatory changes in the number of open channels. After cytochalasin B treatment, lowering the mucosal Na⁺ concentration did not result in the usual compensatory changes in channel densities. There was no prior evidence that cytochalasin B had any actual effect on the F-actin network in the frog skin epithelium. Accordingly, modified cytochemical techniques were designed to demonstrate and localise F-actin in the epithelial granular cells. The direct immunofluorescent method proved useful, but did not allow sufficient resolution to examine the changes to different populations of actin in the cells. We then modified an immunogold method to suit our conditions, and the results demonstrated the localisation of different pools of F-actin and showed the effects of the cytochalasin B and vasopressin.
2
Kafri, Ilan. "Skin breaking strength in broiler chickens." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/54306.
Full textAbstract:
A procedure was developed to examine factors contributing to skin strength of meat-type chickens. Skin breaking strength was initially measured in lines of chickens divergently selected for high (H) and low (L) juvenile body weight, their reciprocal crosses (HL and LH), and an F₂ generation derived from HL and LH matings. Skin of chicks from the LL line was weakest, that from the HH and LH matings strongest, and that from HL and F₂ matings was intermediate. Percentage heterosis for breaking strength was significantly positive while percentage recombination was not significant.
Skin breaking strength and protein, fat, moisture, and total collagen concentrations of skin from the breast, thigh, and back of male and female commercial broilers were then examined in response to diets containing relatively wide or narrow ratios of calories to protein (C:P). Comparisons were made at 28, 42, and 56 days of age. Chickens fed diets containing wider C:P ratios had weaker skin than those fed diets with narrower C:P ratios, with the differences being greater at older than at younger ages. Males had stronger skin than females. Among body sites, breast skin was stronger than thigh skin with that from the back being intermediate in strength. Skin breaking strength did not appear to be consistently associated with either the protein, fat, or collagen concentrations in the skin.
Skin from broiler chicks fed diets with differing C:P ratios was also examined histologically. Males had stronger and thinner skin than females, with the differences in thickness due primarily to differences in the thickness of the hypodermis. Regardless of sex, feeding diets containing wider C:P ratios resulted in weaker and thicker skin. The thicker skin was associated with an increase in the thickness of the hypodermis and a decrease in the thickness of the dermis and epidermis. With the exception of differences between back and thigh skin, increases in breaking strength occurring between skin from different sites were associated with a reduction in total skin thickness and in the thickness of the hypodermis. It was concluded that increased hypodermis thickness and/or decreased thickness of the dermis and epidermis reduced skin strength.
Two experiments were conducted in which skin strength was examined in relation to heat stress and supplemental ascorbic acid. In the first experiment, chicks fed diets containing 0 or 100 mg of ascorbic acid per kg of diet were subjected to either a constant ambient temperature of 23C, a constant ambient temperature of 32C, or a treatment consisting of 32C from 1600 to 1200 hr and 400 from 1200 to 1600 hr (32/400). Both heat stress and supplemental ascorbic acid tended to increase collagen concentrations in the skin, but differences in breaking strength were inconsistent in response to these treatments. Supplemental ascorbic acid, however, partially alleviated reductions in body weight due to heat stress but did not decrease body temperatures of heat-stressed chicks.
In the final experiment, diets containing either 0, 200, or 400 mg/kg of supplemental ascorbic acid were fed to chicks maintained at ambient temperatures of 23 and 34C. Contrary to previous observations, ascorbic acid failed to ameliorate the depressive effect of heat stress on body weight. Supplemental ascorbic acid tended to reduce adrenal, bursa of Fabricius, and spleen weights but had no effect on heterophil and lymphocyte numbers or ratios. Adrenal ascorbic acid concentrations were not significantly affected by supplemental ascorbic acid and plasma ascorbic acid levels were inconsistent among treatment groups. Neither supplemental ascorbic acid nor heat stress significantly influenced skin strength. It was concluded that supplemental ascorbic acid was not beneficial in improving skin strength in commercial broiler chicks.Ph. D.
3
Castellanos, Amber. "The Role of IGF-1 In Geriatric Skin." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1588759288275605.
Full text
4
Slouka, Petr. "Laboratorní měření kožní vodivosti." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221356.
Full textAbstract:
This thesis contains an introduction to anatomy and physiology of the skin highlighting its barrier function. The barrier function of the skin enables it to separate internal organism from external environment. thermore, the electrical properties of the skin are described and possibilities of skin conductance measurement are discussed. The thesis presents a design of a device for the skin conductance measurement as the method of evaluation for barrier function. Alternating current is used for measurement during iontophoresis for evaluation of skin conductance. Circuit design and circuit board are included with a list of parts. The designed device was realized and in the end it was tested and the results were discussed.
5
Brown, Patrick J. P. "Anatomy and Physiology: A Guided Inquiry." Digital Commons @ East Tennessee State University, 2015. http://amzn.com/1119175259.
Full textAbstract:
Students Learn when they are actively engaged and thinking in class. The activities in this book are the primary classroom materials for teaching Anatomy and Physiology, sing the POGIL method. The result is an "I can do this" attitude, increased retention, and a feeling of ownership over the material.https://dc.etsu.edu/etsu_books/1027/thumbnail.jpg
6
RODRIGUES, PRISCILA ANDRADE MAGALHAES. "ANATOMY E PHYSIOLOGY OF AN APPRENTICESHIP." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=14119@1.
Full textAbstract:
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOA pesquisa procura investigar como um estágio supervisionado na formação de professores acontece em uma escola de educação básica. Este estudo tem como base o projeto O estágio nos cursos de formação de professores como uma via de mão dupla entre universidade e escola, que buscou juntar todos os envolvidos no estágio - estagiários, professores supervisores de estágio e professores regentes - para a discussão conjunta sobre o papel do estágio na formação de futuros docentes. Os sujeitos centrais desta pesquisa são aqueles envolvidos nesse projeto, em seu primeiro semestre de desenvolvimento, ao redor de dois cursos de formação de professores da PUC-Rio, Geografia e Letras (Português-Inglês), e de uma escola municipal do Rio de Janeiro. Foram entrevistados oito estagiários, quatro professores supervisores de estágio, dois professores regentes e a diretora da escola. Durante dois meses, as aulas dos dois professores regentes, das respectivas licenciaturas, foram observadas com e sem a presença de seus estagiários. Além disso, as reuniões e encontros com todos os envolvidos foram acompanhados, na tentativa de entender como o estágio se desenvolvia em todas as suas dimensões. A literatura que entende a escola como espaço real da formação inicial e continuada e do desenvolvimento profissional de professores, como se observa em Nóvoa, Perrenoud, Canário, Roldão, Tardif, Lüdke, entre outros, dá sustentação à pesquisa, juntamente com a literatura sobre estágio de Ghedin, Pimenta e Lima. A análise do estágio já foi feita pelos trabalhos de Cardozo (2003) e Albuquerque (2007), um pela ótica dos alunos estagiários, outro pela ótica dos professores regentes. A presente dissertação analisa o estágio supervisionado pela ótica da escola, contribuindo, assim, para sua análise do estágio em três diferentes perspectivas. As constatações indicam que o estágio, no contexto aqui estudado, constitui rica possibilidade de troca entre os envolvidos, mobilizando todos, inclusive os alunos da escola, ou seja, provocando algum tipo de movimento interno de cada sujeito. O estágio observado revelou-se também como mais significativo e menos burocrático para os estudantes, favorecendo a imersão desses futuros professores em seu contexto de trabalho. Constata-se ainda que a aproximação entre todos os sujeitos, estagiários, supervisores de estágio e professores da escola, em uma proposta conjunta de estágio, permite entender o cruzamento de saberes entre universidade e escola. A adesão de todos os envolvidos no estágio a um projeto comum abre possibilidades para se pensar em futuras propostas de formação docente em real colaboração entre estas duas instituições formadoras de professores.
This research seeks to investigate how a supervised teaching practice occurs at a secondary school during teacher education. The study is based on the project Teaching practice in courses for teacher education as a two-way road between university and school, which has sought to bring together those who are involved in teaching practice, such as future teachers, teacher trainers and school teachers, in order to discuss with the group the role of teaching practice in the training of future teachers. The central subjects of this research are those who are involved in the above mentioned project, mainly in its first six months. They come from two teacher education degree courses for teachers in PUC-Rio - Geography and Languages (Portuguese-English) - and from a public sector secondary school in Rio de Janeiro. We interviewed eight future teachers, four teacher trainers, two school teachers and the principal of the school involved. During two months, we observed the classes with or without the presence of future teachers. Besides, we have participated in every meeting with the people involved in the project, in the attempt to understand how the teaching practice would develop as a whole. Our bibliographical support is the literature on school as a real space of initial and continual training and of teacher professional development, as it is possible to learn from Nóvoa, Perrenoud, Canário, Roldão, Tardif and Lüdke among others. We also based our study on the literature on teaching practice taken from Ghedin, Pimenta and Lima as well as on the analysis of teaching practice that has already been carried out by Cardozo (2003) and Albuquerque (2007), the former from the perspective of future teachers, and the latter from that of the school teachers. This dissertation analyzes teaching practice departing from the school, contributing to the analysis of supervised teaching practice from three different perspectives. The analyses indicates that teaching practice, in the context in which we have studied, constitutes a rich opportunity for interchange between those who are involved in it, mobilizing everyone, including the students attending the school; that is, leading to some kind of internal movement of every subject. The observed teaching practice also reveals itself as more significant and less bureaucratic for the trainees, contributing to the immersion of these future teachers in their job context. It is also possible to observe that the approximation between the subjects of the teaching practice, such as future teachers, teacher trainers and school teachers, allows us to understand the movement of knowledge between university and school. The engagement of everyone involved in the current teaching practice process in a common project opens possibilities for thinking about future proposals for teacher education in real collaboration between both teaching institutions.
7
Finch, Catherine Vanessa. "Chemical modification of skin mimic systems." Thesis, University of Huddersfield, 2017. http://eprints.hud.ac.uk/id/eprint/34645/.
Full textAbstract:
This thesis investigates the effect of various physical and chemical surface modification methods on the permeation of topically applied pharmaceutical compounds through poly(dimethylsiloxane) (PDMS), a polymer frequently employed as a model barrier in in vitro skin permeation studies. Such studies are essential for safety, risk assessment, and quality control purposes, in addition to assisting in the design and development of efficacious topically applied medicines. The commercial availability, legal status, ease of handling, and the reproducibility of the permeation data associated with polymeric skin mimics renders them an attractive alternative to biological tissue. However, over-predictions of percutaneous absorption observed following the use of such membranes are a significant disadvantage when attempting to obtain quantitative toxicological data. Accordingly, the aims of the work presented in this thesis were to both reduce the permeability of PDMS to pharmaceutical compounds, and to increase correlation between permeation data obtained using the synthetic substitute and data obtained similarly using suitable biological tissue. Primarily, the potential of an air plasma pre-treatment to produce a lamellae-type structure in PDMS, endeavouring to more accurately model the architectural, physical, and chemical properties of the human stratum corneum, was investigated. Reductions in the permeability coefficient of up to 54.4 % were observed, rendering the modified system promising. Correlation analysis revealed an increase in correlation between the data collected using the modified synthetic substitute (R 2 = 0.86) and a selfcollated library of literature-derived epidermal tissue permeability data, relating to eighteen compounds and spanning a range of typical penetrants, compared to similar analysis using data obtained using the native substitute ( R 2 = 0.75), suggesting an increase in the predictive capability. It was hypothesised that an N2 plasma treatment may provide suitable surface functional groups on the PDMS substrate, namely amine groups, for the covalent attachment of biomolecules via an N,N'- dicylohexylcarbodiimide (DCC) coupling reaction, enabling the production of a skin mimic displaying enhanced biorelevance. Therefore, the effect of an N2 plasma pre-treatment on the permeation of a subset of the eighteen compounds investigated. It was found that the N2 plasma pre-treatment was advantageous in terms of offering a greater reduction in permeability, since longer treatment times could be employed i.e. reductions of up to 61.8 % were observed. However, significant surface oxidation was still observed, with only a marginal increase in nitrogen containing functionalities compared with the air plasma analogue i.e. 0.31 %. Furthermore, the treatment did not offer any additional increase in correlation between epidermal-derived data than previously observed. Further chemical methods of biomolecule attachment were pursued for use in the development of a lipidproteinaceous bilayer model, initiated in both cases by surface amination using an alkoxysilane. This was followed by a DCC coupling to an amino acid in the former approach, and use of a glutaraldehyde III linker molecule to attach the same amino acid, namely lysine, in the latter approach. In either case, no further reductions in the permeation of the pharmaceutical compounds tested were observed, with respect to that through plasma treated PDMS. In summary, the air plasma treatment of PDMS was found to be a promising approach to simultaneously reducing the permeability of a silicone skin mimic and increasing correlation with data obtained in similar studies employing biological tissue. Further, the covalent coupling of biomolecules to the surface of PDMS following surface amine group generation, via both plasma and wet chemical methods, appeared not to compromise the integrity the PDMS membranes relating to such applications, rendering the techniques compatible with the production of biorelevant semi-synthetic skin mimics.
8
Paulet, Julia. "MATURATION OF THE CAROTID BODY OXYGEN-SENSOR DURING RAT DEVELOPMENT." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1337703804.
Full text
9
Schulz, Leslie. "Anatomy and Physiology Syllabus for Community Colleges." Thesis, University of North Texas, 2000. https://digital.library.unt.edu/ark:/67531/metadc2500/.
Full textAbstract:
This syllabus includes both lecture notes and laboratory activities for a two-semester anatomy and physiology community college course. The syllabus is based on a 16-week semester that is comprised of a three-hour lecture section and a one-hour laboratory class each week. Both the lecture course and laboratory are necessary to fulfill the requirement for anatomy and physiology. Laboratory activities coincide with lectures to enhance understanding of each topic by providing visual and hands-on experiments for the concepts learned in the lecture. Laboratory quizzes will be given each week to help students maintain a working knowledge of the material learned in the laboratory. This course is appropriate for the typical anatomy and physiology student and should benefit both students who plan to major in biology and also those who are non-biology majors. Because subject matter in anatomy and physiology is quite difficult, the importance of attendance and good study skills is stressed.
10
Nasimi, Seerous Ghulam Abbas Ali. "Analysis of skin blood flow signals." Thesis, University of Bradford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305700.
Full text
11
Poscher, Elisabeth. "Salinity Effects on Guayule Leaf Anatomy and Physiology." Diss., The University of Arizona, 2005. http://hdl.handle.net/10150/194362.
Full textAbstract:
Salinity usually reduces plant growth in terms of height and biomass, but can increase secondary metabolite production. This frequently reported observation in guayule (Parthenium argentatum Gray, Asteraceae) was investigated for possible mechanisms.Osmotic and specific ion effects of four chloride salts (CaCl2, MgCl2, KCl, and NaCl) on leaf anatomical and plant physiological parameters were studied. One-year-old plants of guayule line AZ 2 were grown under two salt concentrations (750 ppm and 1500 ppm) for each salt type (plus a control) in sand culture (semi-hydroponic) for eight weeks under controlled greenhouse conditions in Tucson, Arizona.Growth in height decreased with increasing salt concentration. Shoot dry weight, rubber, and resin contents, however, showed no significant differences between treatments, indicating no effect from either salt concentration or salt type. There was a trend for increasing rubber content with increasing salt concentration, although not statistically significant. At the same time, net CO2 gas exchange rates decreased significantly with increasing salinity.With increasing salt concentration, guayule showed osmotic effects in terms of height, indicating a lower hydraulic conductivity. Although plants of higher salt concentrations utilized significantly less water, they had the same shoot dry weights, rubber, and resin contents. Salt-stressed plants therefore achieved higher water use efficiencies. The diurnal net CO2 gas exchange rates were significantly reduced with increasing salinity; the nocturnal net CO2 gas exchange rates showed no significant difference between the treatments.Anatomically, it was found that the stomata were raised or elevated above the epidermis, and supported by upwardly curving cells. When guayule was grown under salt treatments, the trichomes were found to include deposits of material. Trichomes might act as a detoxification repository for excess ions. Although the physiological significance of raised stomata is unknown, it is hypothesized that the unique combination of raised stomata, indumentum, and multiple layers of palisade parenchyma allows for an overall high photosynthetic capacity and performance. During stress conditions such as salinity or drought, guayule might activate an internal CO2 concentrating mechanism, i.e., bicarbonate/CO2 pump, internal CO2 recycling, or PEP carboxylation activity.
12
Norlén, Lars Petter Oskar. "The skin barrier : structure and physical function /." Stockholm, 1999. http://diss.kib.ki.se/1999/91-628-3533-5/.
Full text
13
Sanders, Theresa A. "Quantitation of Teratogenic Effects of 5-fluorouracil Administered to Mice in Vivo or in Submerged Limb Culture." Digital Commons @ East Tennessee State University, 1987. https://dc.etsu.edu/etd/2786.
Full textAbstract:
This study demonstrates the use of submerged limb culture in teratologic testing. Pregnant mice were treated on day 11 of gestation (E11, plug date = E0) with 10, 20 or 40 mg of 5-fluorouracil (FU) per kg body weight. On E17, treated and untreated fetuses were examined for gross malformations and were fixed in 95% ethanol. Reduction of limb size and digital defects, including ectrodactyly (ED), syndactyly (SD), microdactyly and polydactyly were dose-dependent. In parallel studies, pregnant mice were treated on the morning of E11 and embryos were removed either 7h (E11) or 24h (E12) later for submerged limb culture. Changes in limb area showed a dose-response relationship while treatment had little effect on the shape of individual bones. This indicates the relatively unspecific nature of FU-induced embryotoxicity. E11 studies revealed a dose dependent response of ED, SD and fusion of the metacarpals/metatarsals (MC/MT) to the proximal phalanges. Unlike E11 cultures, middle phalanges were present but decreased in number as dosage increased. Limbs from embryos of untreated females were cultured (E11) in the presence of 0.002, 0.02, 0.2 or 2.0 mg FU/ml culture medium. The percentage of limbs void of paw cartilage or with decreased numbers of MC/MT was dose-dependent. A dose-dependent decrease in the deleterious effects of 0.02 mg FU/ml was observed when 0.2 or 0.02 mg thymine/ml was added to the cultures. In both culture and non-culture studies, hindlimbs (HL) were more affected than forelimbs (FL) and distal regions were more affected than proximal ones. In addition to the morphometric analyses, biochemical parameters of growth and differentiation were examined at 0, 36 and 72h of culture in untreated and treated limbs. Both DNA and protein of FU treated limbs were decreased compared to untreated controls. FL demonstrated greater capacity for regulation of losses in protein content, HL for DNA content. Submerged limb culture provides a useful model for the examination of xenobiotic effects on limb development and allows some comparative evaluation among in vivo, in vivo/in vitro and in vitro studies. (Abstract shortened with permission of author.)
14
Kardegar, Nadia. "Electrical Brain Stimulation and Depressive-like Behavior in Guinea Pigs." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1342408797.
Full text
15
Garza, Chelsea Raye. "Analysis of Frontal and Maxillary Sinus Dimensions by Computed Tomography scans for Sex Determination." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1503234651997034.
Full text
16
Slominski, Tara. "Drawing on Student Knowledge in Human Anatomy and Physiology." Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/27280.
Full textAbstract:
Prior to instruction, students may have developed alternative conceptions about the mechanics behind human physiology. To help students re-shape these ideas into correct reasoning, the faulty characteristics reinforcing the alternative conceptions need to made explicit. This study used student-generated drawings to expose alternative conceptions Human Anatomy and Physiology students had prior to instruction on neuron physiology. Specifically, we investigated how students thought about neuron communication across a synapse (n=355) and how neuron activity can be modified (n=311). When asked to depict basic communication between two neurons, at least 80% of students demonstrated incorrect ideas about synaptic transmission. When targeting spatial and temporal summation, only eleven students (3.5%) were able to accurately depict at least one form of summation. In response to both drawing questions, student drawings revealed multiple alternative conceptions that resulted in a deeper analysis and characterization of the wide variation of student ideas.North Dakota State University. Department of Biological Sciences
National Science Foundation (NSF DUE-0833268)
17
Findlay, Robin. "The anatomy and physiology of the crab balancing organ." Thesis, University of Aberdeen, 1985. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU362771.
Full textAbstract:
This thesis examines the way in which the crab balancing organ detects low frequency angular accelerations and vibrations. Anatomical studies using light and electron microscopy have confirmed that the statocyst comprises two fluid-filled orthogonal canals in which the sensory elements are long thin hairs (thread hairs) or short hooked hairs (free hook hairs and statolith hairs) which poke into the lumen of the canals. The thread hairs are innervated by two bipolar neurones which send their dendritic processes into modified chordotonal organs; these are characterised by the presence of scolopidial elements accompanied by chitinous strands which link scolopidia with thread hairs. A linear systems technique, namely sinusoidal oscillation of the statocyst was used to examine the frequency response of the statocyst hair receptors in the range 0.6-78Hz. The thread hair/statocyst system is shown to behave as a velocity transducer in the range 0.6-4Hz. Free hook hair receptors also respond to low frequency sinusoids but their output is non-linear. Other nonlinearities exhibited by both receptors include gain adaptation and rectification of the response. In addition a marked position sensitivity is shown by the thread hair receptors. It is concluded that both types of receptor contribute to the detection of low frequency angular accelerations. A response to vibration is demonstrated by both types of receptor although the thread hairs respond only in a very transient way to frequencies above 30Hz. By contrast the free hook hair receptors respond throughout the vibration range tested and are suited to the detection of substrate and water borne signals. They have a best frequency between 30 and 40Hz.
18
Gaten, Edward. "The anatomy and physiology of selected reflecting superposition eyes." Thesis, University of Leicester, 1992. http://hdl.handle.net/2381/34352.
Full textAbstract:
Aspects of the morphology and optical physiology of reflecting superposition eyes have been investigated using species from various decapod crustacean taxa. The eyes all have the same basic structure of a distal dioptric layer and a proximal retinula layer, separated by an unpigmented clear zone. In the eyes of shrimps, lobsters and crayfish the clear zone is crossed by crystalline cone cell extensions. In squat lobsters this region is crossed by rhabdomeric lightguides. Porcelain crabs possess an eye intermediate in design. The superposition ray path, the action of corneal lenses and the presence of lightguides have been demonstrated and the refractive indices of several optical elements determined. These results have been used to produce ray tracing diagrams showing the optical pathways within these eyes. All of the eyes function by redirecting light across the clear zone by reflection within a mirrored crystalline cone. In squat lobsters a rhabdomeric lightguide transmits axial light to the rhabdoms. The eyes have a small f-number resulting in good light-gathering power and maximum sensitivity. However, intracellular electrophysiological determinations of retinula cell angular sensitivity show that these eyes have poor resolution. Variations in morphology and optics represent adaptations to the underwater light field, especially in the tapeta and in the light- sensitive rhabdoms. In oceanic species the tapetum varies in both structure and reflectivity along a dorso-ventral gradient within each eye and also interspecifically. It is proposed that the need to remain well-camouflaged in the low-contrast oceanic environment leads to tapetal modifications. Where sufficient light is available the rhabdoms are adapted to maximize resolution and permit sensitivity to polarized light. In deeper water, where little light remains, the rhabdoms are adapted to increase sensitivity at the expense of resolution. The dorsal region of the eye retains apposition optics for the purpose of detecting small objects in silhouette against the downwelling light.
19
Ade-Ademilua, Omobolanle Elizabeth. "Plastochron index - an indicator of plant structure and function a case study using Pisum sativum L." Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1003751.
Full textAbstract:
The use of chronological age for example, using days after sowing (DAS), or days after germination (DAG) as a time variable may result in the inherent variability between plants resulting in differences which can be large enough to obscure subtle developmental trends that become evident among plants sown at the same time. An alternative to DAS or DAG is the plastochron index (PI), first used by Erickson and Michelini (1957) as a morphological time scale and numerical index; which to according to the authors suggested and represented a more accurate reflection of the developmental status of a plant. The research presented in this thesis was therefore aimed specifically at utilizing the index in qualitative and quantitative analyses, to confirm its usefulness in analyzing and predicting plant growth and development. Specifically this research focused on investigating various morphological and physiological events that together, hopefully, would serve as a template for the prediction of the growth, development and reactions of Pisum sativum L. to different growth conditions. In Chapter 3, the use of the average length of the first pair of leaflets on each node as a suitable parameter for calculating PI in P. sativum is suggested. The results presented in Chapter 3 suggest that plant age is best expressed using the plastochron index, as this reflects the time interval between the initiations of successive pairs of leaflets. This section of the research has been published as “Ade-Ademilua OE, Botha CEJ (2005) A re-evaluation of plastochron index in peas - a case for using leaflet length. South African Journal of Botany 71: 76-80”. The PI formula developed was subsequently used in this research to conduct qualitative and quantitative investigations of plant growth and development in which all data and observations were related directly to the plastochron index. In Chapter 4, the sink to source transition in Pisum sativum L. leaves at different plastochron ages in nodulating plants was investigated using the phloem-mobile fluorescent marker, 5,6-carboxyfluorescein (5,6-CF). The results demonstrated that young leaves remained strong sinks up until LPI 0, after which sink-source transition occurred up to LPI 1.8 and leaflets transitioned to strong source systems by LPI 2.0. A well-developed cross-connected phloem system between paired leaflets in peas, and the petiole and the stem vascular supply was observed. The data presented in the second part of Chapter 4 suggest that the phloem transport between leaflet pairs is independent of the sink/source state of the leaflets, or of movement along the source to sink gradient. The data support the presence of a modular transport system which may ensure re-allocation and balancing between leaflets of the same physiological age and photosynthetic and transport status, thereby load-balancing the local transport system, before exporting to other younger (sink) regions. The investigation of leaf development using the plastochron index (Chapter 5) revealed that the formation of air spaces in the palisade and spongy mesophyll, one of the preparatory events for transition from sink to source state in developing leaves, occurs between LPI 0 and LPI 1 in pea leaflets. Results of the anatomical and ultrastructural study related to PI are presented in Chapter 5. The density of wall ingrowths in transfer cells of minor veins increased with LPI and appeared to be associated with the probable transition to source state and the related potential increase in the production of assimilates for export. The onset of wall ingrowth development in leaflets at LPI 0 provided evidence that sink-to-source transition commences at LPI 0 in P. sativum. Presumably-functional plasmodesmata as well as a few mature sieve elements were evident in class IV veins in the apical region of young and older leaflets at LPI 0. The number of mature sieve elements per vein however, increased with increasing LPI. Most class V veins were still undergoing division at LPI 0 and their sieve elements did not show signs of maturity until LPI 1. The increase in the number of mature metaphloem sieve elements in young, supposedly importing tissue at LPI 0 to older, supposedly exporting tissues at LPI 2 is evidence of the association between phloem maturation and transition from importing to exporting status. In Chapter 6, I report on the effects of elevated CO[subscript 2] on the growth and leaf development of nodulating and non-nodulating Pisum sativum L var. Greenfeast grown under controlled environment of the same nitrogen (6mM) and nitrogen- free nutrient solution conditions. Shortterm exposure to elevated CO[subscript 2] induced rapid plant growth, irrespective of treatment. However, long-term elevated CO[subscript 2] treatment did not affect rate of leaf appearance (RLA) in nodulated plants, irrespective of mineral N supply but enhanced RLA in non- nodulating plants supplied with mineral N. Supplied N resulted in a significant increase in leaflet elongation rate (LfER) under both ambient and elevated CO[subscript 2], but LfER was not significantly affected by nodulation but was increased by high CO[subscript 2]. This suggested that the growth of nodulating P. sativum L may not be significantly affected under CO[subscript 2] levels as high as 1000 μmol mol[superscript -1]. The data suggest that elevated CO[subscript 2] will enhance canopy size, provided adequate soil N is available and more so in non-nodulating plants. This section of the research has been published as “Ade-Ademilua OE, Botha CEJ (2004) The effects of elevated CO[subscript 2] and nitrogen availability supersedes the need for nodulation in peas grown under controlled environmental conditions. South African Journal of Botany 70: 816 – 823”. This thesis demonstrates that the similarity in the qualitative analyses results obtained from plants from different CO[subscript 2], nitrogen and nodulation treatment conditions, highlights the fact that plants of same PI value are at the same developmental state, irrespective of the growth condition. Furthermore, changes in plant structure and function observed under different growth conditions can be related simply to changes in plastochron index. The work presented in this thesis demonstrate that changes in plant structure and function analyzed are related to changes in PI. An important finding of this thesis is that with the use of PI, results can be compiled as a template for predicting the structure- function state of pea plants at any plastochron age, under any growth conditions, before using small representative sample populations.
20
Muir, Eric R. "Magnetic resonance imaging of retinal physiology and anatomy in mice." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37268.
Full textAbstract:
MRI can provide anatomical, functional, and physiological images at relatively high spatial resolution and is non-invasive and does not have depth limitation. However, the application of MRI to study the retina is difficult due to the very small size of the retina. This thesis details the development of MRI methods to image blood flow (BF), anatomy, and function of the retina and choroid, and their application to two diseases of the retina: diabetic retinopathy and retinal degeneration.
A unique continuous arterial spin labeling technique was developed to image BF in mice and tested by imaging cerebral BF. This method was then applied to image layer-specific BF of the retina and choroid in mice, and to acquire BF functional MRI of the retina and choroid in response to hypoxic challenge. Additionally blood oxygen level dependent functional MRI of the mouse retina and choroid in response to hypoxic challenge was obtained using a balanced steady state free precession sequence which provides fast acquisition, has high signal to noise ratio, and does not have geometric distortion or signal dropout artifacts.
In a mouse model of diabetic retinopathy, MRI detected reduced retinal BF in diabetic animals. Visual function in the diabetic mice, as determined by psychophysical tests, was also reduced. Finally, in a mouse model of retinal degeneration, BF and anatomical MRI detected reductions of retinal BF and the thickness of the retina. The studies detailed in this thesis demonstrate the feasibility of layer-specific MRI to study BF, anatomy, and function, in the mouse retina. Further, these methods were shown to provide a novel means of studying animal models of retinal disease in vivo.
21
Bountra, Charanjit. "Physiology of fertilization of mammalian eggs." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/29937.
Full text
22
Damato, Elaine. "Automated analysis in reflectance confocal microscopy images of skin anatomy and pathologies." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/automated-analysis-in-reflectance-confocal-microscopy-images-of-skin-anatomy-and-pathologies(6bff8c67-0b66-4f5e-9f3e-7e885df92977).html.
Full textAbstract:
This thesis contributes to knowledge by developing algorithms that automatically detect and quantify structures of clinical interest in reflectance confocal microscopy (RCM) images, captured in-vivo and from excised skin tissue. The first part of the thesis presents an algorithm that detects the dermalepidermal junction (DEJ), characterised by papillae, in cubes of RCM images of in-vivo skin. A cube of images is a number of mosaic images captured at different depths parallel to the skin surface. A classifier, which makes use of texture and anatomical-based features was designed. The anatomical-based features are parameters that quantify the absence and presence of papillae across different images of the cube. The second part of the thesis analyses RCM images of excised tissue collected during Mohs surgery. These tissue samples include basal cell carcinoma (BCC) and non-diseased samples. An algorithm was developed to differentiate between (i) cancerous regions, (ii) regions of inflammation, and (iii) non-diseased regions. A classifier based on texture and nuclei-concentration features was designed. The nuclei concentration in cancerous sites is different from that in nondiseased sites and thus can be used to distinguish the two. The third part of the thesis analyses RCM video sequences of in-vivo skin imaged at the level of the DEJ. The boundaries of superficial skin capillaries can be delineated by visually observing the highly reflective red blood cells (RBCs) passing through the capillaries. An algorithm that automatically detects skin capillaries in RCM video sequences was developed. Additionally, an algorithm that quantifies the velocity of RBCs in cross-sectionally imaged capillaries is devised. The change in total capillary area (per unit frame area), individual capillary parameters and RBC velocity due to incremental ultra-violet radiation (UVR) doses are analysed in both fair and dark skinned volunteers. The work presented in this thesis has the potential to increase the acceptance of RCM in the dermatology clinic, both for diagnosis and for assessing treatment response of skin conditions located at (or above) the DEJ. Additionally, the thesis enhances the potential of using RCM images of excised samples instead of preparing the tissue for histological examinations during surgery.
23
Al, Hadi Mouafak. "Motion of the foot inside a hockey skate: As measured from bone, skin, and skate markers." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6210.
Full textAbstract:
In filming and digitizing human segmental motion, external markers do not necessarily represent a true picture of the actual bone movement. When surface markers are placed on the skin or skate boot (in ice hockey) they move according to skin or boot movement, which does not exactly match bone movement. This results in a misrepresentation of the joint axes of rotation and a greater margin of error in motion measurement and analysis. This problem occurs for ankle and foot movements as their motion is quantified about the ankle joint complex (talocrural and subtalar joints). Hockey skates are vastly more rigid than regular shoes and their restriction of foot movement is greater. Therefore, shoes and hockey skates cannot be considered identical. The present study aims at exploring differences amongst bone, skin, and skate marker based motions of the foot during skating. (Abstract shortened by UMI.)
24
Ragland, Mary C. "The Velocity of Hyolaryngeal Excursion in Normal Swallowing." Ohio University Honors Tutorial College / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1400521302.
Full text
25
Boue, Jenna E. "Sex Differences in Thrombosis with Canine Basilar Artery and Murine Middle Cerebral Artery Thromboembolic Stroke Models." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587048703654416.
Full text
26
De, Boef Maria Elizabeth. "Effects of phylogeny, physiology, and function on bone microstructure in extant endothermic vertebrates." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86513.
Full textAbstract:
A strong relationship between bone macrostructural morphology and bone mechanical function has been well documented and is an essential component of many vertebrate biomechanical studies. However, a vastly richer data set could be had if the relationship between bone microstructure and bone function were as well understood. This thesis enumerates the bone microstructure-function relationship in a statistically consistent manor in extant endotherms.Phylogeny, physiology and function have been shown to independently contribute to bone microstructure morphology. However, rarely have two or more of these factors been examined in combination. In this work the author used various statistical and experimental techniques to quantify the contribution of each of these factors to bone microstructure.
This work is organized into four parts: First, a review of methods used to quantify bone microstructure is given and a new method for quantifying vascular orientation proposed. This method allows the researcher to observe vascular orientation as an unbiased continuous measure and therefore complete more extensive statistical testing. Second, an analysis of the use of skeletochronology for aging three species of extant carnivores is given. This technique, although rarely used in extant endotherms, is commonly used for aging specimens from palaeontological findings. Upon discovering a significant discordance between organismal age and skeletochronology in the carnivorans studied here, I discuss the validity of its use in palaeontology. Third, using a sample of seven carnivoran species, the impact of phylogeny, function and physiology on bone microstructure was tested using a variance partitioning method. It was found that phylogeny has a large and significant impact on bone microstructural characteristics but only in conjunction with functional and physiological variables. When considering the effects of the three "pure" factors I found that physiological factors are the major drivers of bone microstructure. To further explore these findings, the final chapter presents an experimental study on the effects of biomechanical function and repeated loading on the humerus and tibiotarsus in Helmeted GuineaFowl. It was found that the type of strain and the repetition of strain from exercise both significantly impact bone microstructure but the relationship between tensile, compressive and shear strains to microstructure is complex with no obvious correlation.
Il existe une forte relation entre la morphologie de la structure macroscopique des os et leurs caractéristiques fonctionnelles au niveau mécanique. Cette relation est bien documentée et est un aspect essentiel de plusieurs études sur la biomécanique des vertébrés. Cependant, un ensemble de données beaucoup plus étoffé serait disponible si la relation entre la morphologie de la microstructure des os et leur fonction était mieux comprise. La présente thèse comporte une énumération des relations entre la microstructure des os et leurs caractéristiques fonctionnelles chez certaines espèces actuelles d'endothermes, en suivant une approche statistique cohérente.
Il a été démontré que la phylogénie, la fonction et la physiologie contribuent séparément à la morphologie de la microstructure des os. Cependant, les effets combinés de deux ou plusieurs de ces facteurs ont rarement été examinés. Dans la présente étude, l'auteur a utilisé plusieurs méthodes statistiques et expérimentales afin de quantifier l'impact respectif de chacun de ces facteurs sur la microstructure des os.
Cette thèse est organisée en quatre parties. D'abord, une revue des méthodes utilisées pour quantifier la microstructure des os est présentée et une nouvelle méthode pour quantifier l'orientation vasculaire est proposée. Cette nouvelle méthode permet d'observer l'orientation vasculaire d'une manière continue et non-biaisée, et permet donc une analyse statistique plus approfondie. Ensuite, l'utilisation de la squelettochronologie pour la détermination de l'âge de trois espèces de carnivores est analysée. Cette technique, bien que rarement utilisée pour déterminer l'âge chez les endothermes actuels, est communément employée pour les espèces paléontologiques. À la suite de la découverte d'une discordance significative entre l'âge des organismes et la squelettochronologie chez les carnivores étudiés ici, la validité de cette technique en paléontologie est discutée. En troisième partie, à partir d'un échantillon de sept espèces de carnivores et au moyen d'une analyse de partition de variance, l'impact de la phylogénie, de la fonction et de la physiologie sur la microstructure des os a été testé. Il a été découvert que la phylogénie avait un impact important sur la microstructure des os, mais seulement en conjonction avec les variables liées à la fonction et à la physiologie. Lorsque les effets des trois facteurs « purs » étaient considérés, la physiologie était le facteur qui contribuait le plus à la variabilité observée dans la microstructure des os. Afin d'examiner ces résultats plus en détail, le chapitre final présente une expérience investiguant les effets d'une charge répétée et de la fonction biomécanique sur l'humérus et le tibiotarse de la pintade de Numidie (Numida meleagris). Le type d'effort et la répétition de l'effort imposé par l'exercice avaient tous les deux un impact significatif sur la microstructure des os, mais les relations entre les forces de tension, de compression et de cisai
27
Nguyen, Quant. "The myofibrillar and connective tissue content of selected bovine muscles and porcine cardiac and skin tissues /." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66137.
Full text
28
Lazic, Tamara. ""Anatomy, physiology and management of patients with diffuse pulmonary arteriovenous malformations"." [New Haven, Conn. : s.n.], 2008. http://ymtdl.med.yale.edu/theses/available/etd-12092008-103910/.
Full text
29
St, Aubin Helen. "Implementing a Virtual Reality Paradigm in Human Anatomy/Physiology College Curricula." NSUWorks, 2000. http://nsuworks.nova.edu/gscis_etd/393.
Full textAbstract:
Modes of instruction in the college course called Human Anatomy/Physiology are changing. Due to ethical concerns and the ever-increasing source of new physiological data, there is a need for enhancements to assist the instructor and student. The computer science of virtual reality (VR) provides a method to electronically educate, train, prototype, and test and evaluate new enhancements to the college curricula. This study detailed the modeling and simulation of a skeletal human hand with degrees of freedom of movement, which provided the students with a physiological representation of some of the movements of the hand. The primary objectives of the study were to assess the use of the VR simulation by college students and to assess the potential learning outcomes of students in their use of the VR simulation. The simulation was implemented into classes of Human Anatomy/Physiology are as an adjunct enhancement for the students' use. The expectation centered on the constructivist theory that students develop an analytic outlook to the various articulations of the human skeleton. Positive results were shown based on the answers to the questionnaire, summary and post -test taken by the students, after their use of the VR simulation. The results supported the constructivist theory that critical thinking took place. The results showed that the virtual reality simulation enhanced the learning ability of the students. The recommendations of the study include future experimentation to be done on increasing the number of VR simulations, incorporating the VR simulations into undergraduate courses, testing the outcomes, and following the progression of students into graduate programs that are using VR simulations. Faculty and administration are advised to consider implementing the paradigm of VR simulations in undergraduate courses of Human Anatomy/Physiology are.
30
Viessmann, Olivia. "Magnetic resonance imaging of cerebrovascular anatomy and physiology at 7 Tesla." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:6439960f-0da1-44c0-a67d-489cc36cdd40.
Full textAbstract:
Magnetic Resonance Imaging (MRI) can study the cerebrovasculature non-invasively in humans. It can image the vascular anatomy, as well as functional attributes such as flow and perfusion. This multi-modal capability renders MRI one of the most favourable imaging techniques to study the cerebrovasculature in research and in clinical settings. The advent of human 7 Tesla (7T) MRI offers further benefits to existing methods. Most evidently, the higher signal-to-noise ratio (SNR) can be used to improve resolution. However concomitant changes in contrast mechanisms, an increase in the specific absorption rate (SAR) and transmit B1-field inhomogeneity need to be addressed when transitioning to higher field. Vessel wall imaging (VWI) is an exemplar application that benefits from higher resolution but is based on SAR intense methods. In the first part of this thesis the implementation of a VWI method, DANTE-SPACE, is described. The readout scheme was specifically optimised for high resolution wall depiction and enhanced suppression of cerebrospinal fluid to produce vessel wall contrast in the major intracranial arteries at 7T. Besides refining spatial scales, recent technical developments have accelerated information content in the temporal domain. In-slice acceleration and simultaneous excitation of multiple slices substantially reduced acquisition times for many applications. In particular, multiband techniques have pushed sampling speeds in functional MRI (fMRI) to sub-second regimes. Traditionally, fMRI is used to study low frequency neuro-vascular signals below 0.1Hz. Aliases of cardio-respiratory-induced signals have been regarded as "physiological noise". Sufficiently fast sampling resolves the spectrum beyond the cardiac frequency, thus transforming noise into valuable signal. In the second part of this thesis strategies to map and quantify signal fluctuations at the cardiac frequency are described using echo-planar imaging (EPI). Potential age-related difference in the cardiac EPI signal power were studied. Also, an investigation was made into the underlying MR-mechanisms that form these fluctuations by decomposing the EPI-signal over the cardiac cycle into S0 and T2* waveforms. Ultimately this research aims to foster the understanding of the vascular origins of cardiac-induced EPI signals. This will hopefully serve future research into how EPI data can be exploited to study cerebrovascular properties in healthy and diseased states.
31
Levee, Kathryn E. "Gross and Histological Features of a Myofascial Trigger Point in the Upper Trapezius." Digital Commons @ East Tennessee State University, 1996. https://dc.etsu.edu/etd/2938.
Full textAbstract:
The purpose of this study was to precisely locate, in living humans, a myofascial trigger point associated with the upper portion of the trapezius muscle (TrP1) that refers pain to the head and neck and to determine if this point is associated with anatomical structures. This study is descriptive and utilizes data from measurements of the location of TrP1 in relation to anatomical landmarks, of pressure sensitivity overlying the trigger point and electromyography recordings in localizing the trigger point. Information obtained from living humans was used to determine anatomical correlation to structures in cadavers. Results indicated there is little variability in the location of TrP1 among individuals or from one extremity to the other, and this point may be associated with structures of the skin. A neurovascular supply (NAV) emerging from the upper trapezius to the skin was located in cadavers resembling the location of TrP1 in living humans. This NAV contained only small diameter nociceptive nerve fibers. Conclusion from the study show that TrP1 in living humans can be precisely located and that the mechanism of pain referral may involve structures of the skin. Future studies to precisely locate other myofascial trigger points may aid in identifying mechanisms of trigger point activation as well as aid clinicians in more precisely locating trigger points for treatment.
32
Joung, Hyojee. "Changes in copper and zinc metabolism after trauma." The Ohio State University, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=osu1382028154.
Full text
33
Jaggers, Robert Maxwell. "Is Polyvinylidene diflouride (PVDF) film biocompatible in the Murine Cochlea?" Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1440944212.
Full text
34
Nicander, Ingrid. "Electrical impedance related to experimentally induced changes of human skin and oral mucosa /." Stockholm, 1998. http://diss.kib.ki.se/search/diss.se.cfm?19980907nica.
Full text
35
Watson, Patricia A. "The biochemistry and physiology of the immature cereal pericarp." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/27625.
Full text
36
VanBuren, Collin. "Assessing sources of variation in amphibian skin thickness : ecological and evolutionary implications." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/267899.
Full textAbstract:
The skin is the largest organ of the body and provides many functions. Among tetrapod vertebrates, amphibian skin is semi-permeable and responsible for a greater proportion of water absorption and gas exchange. Myriad factors affect the physiological performance of amphibian skin. Morphological traits linked with amphibian skin physiology or ecology have remained difficult to discern because of a lack of quantitative comparative research and the discovery of sources of intraspecific variation that are mostly ignored in study designs. This thesis aims to address the effects of these sources of variation using a trait that is known to vary between sexes, among seasons, and among body regions and thought to be linked with physiology or ecology, skin thickness. The first source of variation addressed is sexual dimorphism. Specimens of the white-lipped treefrog, Litoria infrafrenata, that display sexual dimorphism in body size and skin thickness were used to test if body size was the main determinate of sexually dimorphic skin thickness. Size corrected values did not significantly differ between males and females, although the sample size was small. Seasonal variation in skin thickness has also been documented in some species, so the American bullfrog (Lithobates catesbeianus), the Northern leopard frog (L. pipiens), and the spring peeper (Pseudacris crucifer) from multiple months of the year were sampled to determine if skin thickness increased in the autumn or winter months. Seasonal skin thickening was only detected in L. catesbeianus, and skin from autumn and winter was significantly thicker than from earlier in the year. This pattern was also detectable in museum specimens collected 80 years ago, although the signal was damped, possibly due to preservation. Using a dataset of 10 species and published data, a general pattern was uncovered whereby the dorsal skin is the thickest region and the ventral thigh region is the thinnest. However, this pattern is not always true for every individual of every species (L. pipiens and P. crucifer) and in some species the dorsal skin is thinnest (Bokermannohyla alvarengai and Litoria infrafrenata). The same dataset found that skin thickness is significantly related to body size, as was found in the chapter on Litoria infrafrenata. Summer specimens of Lithobates catesbeianus were outliers below the interspecific regression line and winter specimens fell within the range of variation of other species, hinting that seasonal skin thickening could be renamed seasonal skin thinning in this species. Finally, a link between ecology and skin thickness was tested using the 10 species from previous analyses and data from the literature. At a phylogenetially broad scale, body size explained a greater amount of the variation in environmental parameters than skin thickness. At smaller taxonomic scales, skin thickness appears more closely linked with ecology. It is concluded that amphibians generally follow an allometric trend for skin thickness and when faced with suboptimal conditions over long periods of time, evolve integumentary structures like iridiophores to compensate for any physiological disadvantage of an ‘ideal’ skin thickness. In the interim, however, skin thickness may change, thus sacrificing e.g. mechanical support.
37
Montplaisir, Lisa Marie. "Opportunities for learning in an introductory undergraduate human anatomy and physiology course." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/280438.
Full textAbstract:
The purpose of this study was to explore the course conditions that support the development of meaningful student learning in an introductory undergraduate human anatomy and physiology course. The study was conducted during an 8-week summer-session at a small mid-western university. Classroom observations and taped recordings of class sessions were used to determine content episodes within the instructional unit, opportunities for learning created by the instructor, demonstrations of information processing by the students, and the ways in which the instructor used the Personal Response System (PRS). Student interviews were used to determine students' level of understanding of pre-test and post-test items. Student interviews and a questionnaire were used to determine students' perceptions of the PRS as a learning tool. Findings reveal that the instructor had different expectations of students when posing verbal questions in-class than he had when posing PRS questions. The use of verbal questions did not permit demonstrations of student understanding; however, the use of the PRS did result in demonstrations of student understanding. Questions posed via the use of the PRS were categorized according to cognitive level. The cognitive level of the questions increased with time over the instructional unit and within the content episodes. Students demonstrated deeper understanding of the topics after instruction than they did before instruction. Students reported more in-class thinking about the content, more discussion of the content with their neighbors, more regular class attendance, more opportunities for deeper learning, and a general preference for the PRS over traditional lectures. Findings of the study indicate that the instructional decisions about the use of questions influences the opportunities for students to process information and demonstrate their understanding of the content and that students valued these opportunities. A better understanding of the conditions that promote meaningful student learning may help us make decisions that result in improved student learning in our own classes.
38
Levy, Jacqueline Anita. "Causal-comparative study analyzing student success in hybrid anatomy and physiology courses." Thesis, Northern Arizona University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3606821.
Full textAbstract:
In the biological sciences, higher student success levels are achieved in traditionally formatted, face-to-face coursework than in hybrid courses. The methodologies used to combine hybrid and in-person elements to the course need to be applied to the biological sciences to emulate the success seen in the traditional courses since the number of hybrid course offerings at community colleges are rapidly increasing.
Research has delineated that creating online collaborative communities and increasing student engagement all function to increase student successful outcomes. This causal-comparative study was conducted using student data from four sections of hybrid, introductory anatomy and physiology courses over the 2011 and 2012 calendar years. The study included two sources of data: unit exam scores and student surveys. Analysis of the unit exam scores determined that there were statistically significant differences in student success and achievement by the implementation of the following web-enhanced technologies: a) discussion boards, b) Breeze, and c) Wiki tools. In the scope of this study, student success and achievement was defined as a student earning a C (70%) or higher at the completion of the course.
There were a total of 29 surveys conducted per each unit during the 2012 semesters that related to the web-enhanced technologies implemented into the course: Discussion boards, Breeze®, and Wiki tools. Demographic data was also compiled on all of the students enrolled in the classes during this study to demonstrate that there is no specified niche or trend seen in the students enrolling for this particular course. Unit 1 was used as a baseline to compare the students from the two years. It was determined that the students were not significantly different in aptitude levels at the beginning of the courses based on their Unit 1 exam scores.
Inferential statistical analysis was done to examine student success and achievement using the following tools: t-test of independent means of the variables, mean, standard deviation, and magnitude of effect. The findings of this study indicate that the web-enhanced technology Wiki tools provided the largest increase in student success and achievement in the hybrid, introductory anatomy and physiology course. Descriptive analysis of the surveys revealed that more than a third of each class felt that the implemented web-enhanced technology functioned to increase collaboration amongst the students and helped to emulate a traditional, face-to-face formatted course.
The study included four recommendations for practice and nine recommendations for further research. A couple of recommendations for practice included using a single web-enhanced technology for the duration of the semester and having instructors and students complete tutorial sessions for the chosen technology being implemented. Examples of recommendations for research include replicating this study at other institutions and comparing face-to-face, traditional classes to hybrid courses within the same STEM discipline.
39
Pagani, Angelo. "The Effects of Raspberry Ketone Supplementation on Body Composition." Ohio Dominican University Honors Theses / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=oduhonors1430845300.
Full text
40
Quinn, Melissa Marie. "Learning Styles of Undergraduate Students and Its Influence on the Preference of Lecture Delivery Method in a Large Enrollment Undergraduate Gross Anatomy Course." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1440146297.
Full text
41
Formenti, Federico. "The role of hypoxia-inducible factor in systemic human physiology." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:421232a5-1bab-4612-a6d4-30bdb35beb7a.
Full textAbstract:
This thesis summarizes a research programme on the role of hypoxia-inducible factor (HIF) and its 2alpha subunit in systemic human physiology. Experiments were performed to assess the role of HIF in the regulation of skeletal muscle metabolism, cardiac anatomy, function and energy metabolism, and in cardiopulmonary physiology. Patients with different genetic mutations affecting the HIF pathway were recruited for each main study. Chapter 1 presents an overview of human physiological responses to hypoxia in a historical perspective, with particular attention to the areas of human physiology that are relevant for the studies presented in the experimental chapters. Chapter 1 also presents a summary of the HIF pathway and the novel findings presented in this thesis. Chapter 2 illustrates the methods used to perform the experiments. Chapter 3 investigates skeletal muscle metabolism, cardiac anatomy, function and energy metabolism in patients with Chuvash polycythaemia, who have mildly elevated levels of HIF, associated with a mutation in von Hippel-Lindau gene, at whole body level. Chapter 3 shows major abnormalities associated with HIF pathway alterations in skeletal muscle energy metabolism, especially in conditions of metabolic stress such as during exercise and digestion of a meal. Chapter 4 shows that patients with Chuvash polycythaemia also have small hearts and reduced cardiac energy levels. Chapter 5 explores cardiopulmonary abnormalities in patients with gain-of-function mutations specifically in HIF-2alpha subunit; these patients are polycythaemic like patients with Chuvash polycythaemia. Observed abnormalities include pulmonary hypertension, elevated heart rate, cardiac output, ventilation, and the increment in pulmonary blood pressure in response to moderate hypoxia. Chapter 6 presents results from experiments in patients with classic von Hippel- Lindau disease, who are not usually polycythaemic. However, some degree of haploinsufficiency was observed in their neutrophils, suggesting a pseudo-hypoxic phenotype. Chapter 6 shows that von Hippel-Lindau disease is not associated with major cardiopulmonary abnormalities. Overall, the research reported in this thesis presents original experimental evidence for the effects of alterations in the HIF pathway on human physiology.
42
Kalyanaraman, Balaji. "Bioreactors to Demonstrate Process Automation and Regulate Physiology of Engineered Skin Substitutes." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1210506859.
Full text
43
Narayanaswamy, Variankaval. "Characterization of phase transitions in transdermal drug delivery systems." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/8645.
Full text
44
Everard, J. D. "The physiology of plants subjected to oxygen deficient rooting environments." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355689.
Full text
45
Haubert, Lisa Marie. "Surgical Clinical Correlates in Anatomy: Implementation of a First-Year Medical School Program." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1253374287.
Full text
46
Magee, Corin Wolfgang. "EFFICACY OF MASTERY-BASED AND AUTONOMY-SUPPORTIVE NEUROANATOMY CURRICULUM IN GRADUATE LEVEL HUMAN NEUROBIOLOGY COURSE." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1431086741.
Full text
47
Starr, Nichola. "Investigating native and exogenous compounds within skin tissue." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/39139/.
Full textAbstract:
The skin is the most extensive and accessible organ in the human body. It efficiently provides a barrier to an external hostile environment whilst maintaining and regulating fundamental physiological functions. The sophisticated and complex nature of this natural barrier requires continued analytical advancement to offer further insight into both its biological mechanisms and how to target the delivery of compounds through it. This work presents the use of a recently emerging technique in the field of skin research, time of flight - secondary ion mass spectrometry (ToF-SIMS), to investigate the presence of both native and exogenous compounds in skin tissue from samples collected both in vivo and ex vivo. Subtle changes to the stratum corneum lipid composition have been shown to exert significant effects on the barrier properties of the skin and are associated with numerous skin disorders. The analysis of these lipid species and factors affecting their composition, both internal and external, is therefore a vital area of research. Using ToF-SIMS, this work has conducted an examination of changes to this lipid composition that have resulted from aging of the skin. This has been achieved by undertaking extensive development of a recently proposed surface analysis method to analyse sequential tape strips of stratum corneum. This study was unprecedented in demonstrating that ToF-SIMS could obtain information on human skin from samples collected in vivo. Changes in the levels of both cholesterol sulfate and long chain fatty acids were observed as a consequence of both intrinsic and extrinsic aging, offering confirmatory evidence to previously theorised skin aging mechanisms. Research relating to the effective permeation of compounds across this skin barrier is also of upmost importance, both to the pharmaceutical and cosmetic industries, to enable the design of new topical formulations for skin delivery. Currently employed methods to assess the permeation of a compound are heavily focused on dermal delivery, with limited information obtained on the effectiveness of a compound to permeate into the upper layers of the skin. This research has therefore pioneered a dynamic SIMS method to conduct depth profile analysis of ex vivo porcine skin tissue, enabling the permeation of exogenous compounds to be monitored as a function of skin depth. This work is novel in successfully producing 3D spatially resolved chemical profiles of exogenous compounds within biological tissue using ToF-SIMS. The permeation of four different vitamin C related compounds, popular ingredients in anti-aging cosmetic formulations, were assessed using this method, highlighting a significant difference in permeation efficiency between them. An investigation into the delivery of ascorbic acid to the skin from various different formulations was also achieved, highlighting a permeation enhancing effect from delivery via a novel supramolecular gel formulation. The method developed for surface analysis was also successfully applied to monitor the permeation of ascorbic acid through human stratum corneum following in vivo application of an ‘off-the-shelf’ cosmetic product.
48
Kätzel, Dennis. "Optogenetic analysis of inhibitory circuits in the neocortex." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:b6b39ccc-25e9-49d2-aa1d-ef7ff6abb486.
Full text
49
Shih, Michelle. "Dgat1 modulates hair cycling and is essential for retinoid homeostasis in the skin." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3261244.
Full text
50
Crook, Tracy. "The functional anatomy of equine hind limb muscles and their activation patterns during different locomotor tasks." Thesis, Royal Veterinary College (University of London), 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572457.
Full text