WorldWideScience

Sample records for optics physiological

  1. A Fibre Optic Sensor Of Physiological Parameters

    Science.gov (United States)

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

    1986-11-01

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

  2. Intrinsic optical signal imaging of retinal physiology: a review

    Science.gov (United States)

    Yao, Xincheng; Wang, Benquan

    2015-09-01

    Intrinsic optical signal (IOS) imaging promises to be a noninvasive method for high-resolution examination of retinal physiology, which can advance the study and diagnosis of eye diseases. While specialized optical instruments are desirable for functional IOS imaging of retinal physiology, in depth understanding of multiple IOS sources in the complex retinal neural network is essential for optimizing instrument designs. We provide a brief overview of IOS studies and relationships in rod outer segment suspensions, isolated retinas, and intact eyes. Recent developments of line-scan confocal and functional optical coherence tomography (OCT) instruments have allowed in vivo IOS mapping of photoreceptor physiology. Further improvements of the line-scan confocal and functional OCT systems may provide a feasible solution to pursue functional IOS mapping of human photoreceptors. Some interesting IOSs have already been detected in inner retinal layers, but better development of the IOS instruments and software algorithms is required to achieve optimal physiological assessment of inner retinal neurons.

  3. Marius Tscherning (1854-1939): his life and work in optical physiology

    DEFF Research Database (Denmark)

    Norn, Mogens; Jensen, O.A.

    2004-01-01

    Ophthalmology, Marius Tscherning, accommodation, colour vision, dark vision, entopic phenomena, medical history, ophthalmophacometer, optic physiology, photometric glasses, spectacle lenses......Ophthalmology, Marius Tscherning, accommodation, colour vision, dark vision, entopic phenomena, medical history, ophthalmophacometer, optic physiology, photometric glasses, spectacle lenses...

  4. Fiber optic biofluorometer for physiological research on muscle slices

    Science.gov (United States)

    Belz, Mathias; Dendorfer, Andreas; Werner, Jan; Lambertz, Daniel; Klein, Karl-Friedrich

    2016-03-01

    A focus of research in cell physiology is the detection of Ca2+, NADH, FAD, ATPase activity or membrane potential, only to name a few, in muscle tissues. In this work, we report on a biofluorometer using ultraviolet light emitting diodes (UV-LEDs), optical fibers and two photomultipliers (PMTs) using synchronized fluorescence detection with integrated background correction to detect free calcium, Ca2+, in cardiac muscle tissue placed in a horizontal tissue bath and a microscope setup. Fiber optic probes with imaging optics have been designed to transport excitation light from the biofluorometer's light output to a horizontal tissue bath and to collect emission light from a tissue sample of interest to two PMTs allowing either single excitation / single emission or ratiometric, dual excitation / single emission or single excitation / dual emission fluorescence detection of indicator dyes or natural fluorophores. The efficient transport of light from the excitation LEDs to the tissue sample, bleaching effects of the excitation light in both, polymer and fused silica-based fibers will be discussed. Furthermore, a new approach to maximize light collection of the emission light using high NA fibers and high NA coupling optics will be shown. Finally, first results on Ca2+ measurements in cardiac muscle slices in a traditional microscope setup and a horizontal tissue bath using fiber optic probes will be introduced and discussed.

  5. Physiology

    Science.gov (United States)

    Kay, Ian

    2008-01-01

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

  6. Application of optical non-invasive methods in skin physiology

    Science.gov (United States)

    Lademann, J.; Patzelt, A.; Darvin, M.; Richter, H.; Antoniou, C.; Sterry, W.; Koch, S.

    2008-05-01

    In the present paper the application of optical non-invasive methods in dermatology and cosmetology is discussed. Laser scanning microscopy (LSM) and optical coherent tomography (OCT) are the most promising methods for this application. Using these methods, the analysis of different skin parameters like dryness and oiliness of the skin, the barrier function and the structure of furrows and wrinkles are discussed. Additionally the homogeneity of distribution of topically applied creams, as well as their penetration into the skin were investigated. It is shown that these methods are highly valuable in dermatology for diagnostic and therapy control and for basic research, for instance in the field of structure analysis of hair follicles and sweat glands. The vertical images of the tissue produced by OCT can be easily compared with histological sections. Unfortunately, the resolution of the OCT technique is not high enough to carry out measurements on a cellular level, as is possible by LSM. LSM has the advantage that it can be used for the investigation of penetration and storage processes of topically applied substances, if these substances have fluorescent properties or if they are fluorescent-labelled.

  7. A novel noninvasive all optical technique to monitor physiology of an exercising muscle

    Science.gov (United States)

    Saxena, Vishal; Marcu, Laura; Karunasiri, Gamani

    2008-11-01

    An all optical technique based on near-infrared spectroscopy and mid-infrared imaging (MIRI) is applied as a noninvasive, in vivo tool to monitor the vascular status of skeletal muscle and the physiological changes that occur during exercise. A near-infrared spectroscopy (NIRS) technique, namely, steady state diffuse optical spectroscopy (SSDOS) along with MIRI is applied for monitoring the changes in the values of tissue oxygenation and thermometry of an exercising muscle. The NIRS measurements are performed at five discrete wavelengths in a spectral window of 650-850 nm and MIRI is performed in a spectral window of 8-12 µm. The understanding of tissue oxygenation status and the behavior of the physiological parameters derived from thermometry may provide a useful insight into muscle physiology, therapeutic response and treatment.

  8. [INVITED] Non-intrusive optical imaging of face to probe physiological traits in Autism Spectrum Disorder

    Science.gov (United States)

    Samad, Manar D.; Bobzien, Jonna L.; Harrington, John W.; Iftekharuddin, Khan M.

    2016-03-01

    Autism Spectrum Disorders (ASD) can impair non-verbal communication including the variety and extent of facial expressions in social and interpersonal communication. These impairments may appear as differential traits in the physiology of facial muscles of an individual with ASD when compared to a typically developing individual. The differential traits in the facial expressions as shown by facial muscle-specific changes (also known as 'facial oddity' for subjects with ASD) may be measured visually. However, this mode of measurement may not discern the subtlety in facial oddity distinctive to ASD. Earlier studies have used intrusive electrophysiological sensors on the facial skin to gauge facial muscle actions from quantitative physiological data. This study demonstrates, for the first time in the literature, novel quantitative measures for facial oddity recognition using non-intrusive facial imaging sensors such as video and 3D optical cameras. An Institutional Review Board (IRB) approved that pilot study has been conducted on a group of individuals consisting of eight participants with ASD and eight typically developing participants in a control group to capture their facial images in response to visual stimuli. The proposed computational techniques and statistical analyses reveal higher mean of actions in the facial muscles of the ASD group versus the control group. The facial muscle-specific evaluation reveals intense yet asymmetric facial responses as facial oddity in participants with ASD. This finding about the facial oddity may objectively define measurable differential markers in the facial expressions of individuals with ASD.

  9. Ambulatory diffuse optical tomography and multimodality physiological monitoring system for muscle and exercise applications

    Science.gov (United States)

    Hu, Gang; Zhang, Quan; Ivkovic, Vladimir; Strangman, Gary E.

    2016-09-01

    Ambulatory diffuse optical tomography (aDOT) is based on near-infrared spectroscopy (NIRS) and enables three-dimensional imaging of regional hemodynamics and oxygen consumption during a person's normal activities. Although NIRS has been previously used for muscle assessment, it has been notably limited in terms of the number of channels measured, the extent to which subjects can be ambulatory, and/or the ability to simultaneously acquire synchronized auxiliary data such as electromyography (EMG) or electrocardiography (ECG). We describe the development of a prototype aDOT system, called NINscan-M, capable of ambulatory tomographic imaging as well as simultaneous auxiliary multimodal physiological monitoring. Powered by four AA size batteries and weighing 577 g, the NINscan-M prototype can synchronously record 64-channel NIRS imaging data, eight channels of EMG, ECG, or other analog signals, plus force, acceleration, rotation, and temperature for 24+ h at up to 250 Hz. We describe the system's design, characterization, and performance characteristics. We also describe examples of isometric, cycle ergometer, and free-running ambulatory exercise to demonstrate tomographic imaging at 25 Hz. NINscan-M represents a multiuse tool for muscle physiology studies as well as clinical muscle assessment.

  10. Inflammatory stimulation preserves physiological properties of retinal ganglion cells after optic nerve injury

    Directory of Open Access Journals (Sweden)

    Henrike eStutzki

    2014-02-01

    Full Text Available Axonal injury in the optic nerve is associated with retinal ganglion cell (RGC degeneration and irreversible loss of vision. However, inflammatory stimulation (IS by intravitreal injection of Pam3Cys transforms RGCs into an active regenerative state enabling these neurons to survive injury and to regenerate axons into the injured optic nerve. Although morphological changes have been well studied, the functional correlates of RGCs transformed either into a de- or regenerating state at a sub-cellular level remain unclear. In the current study, we investigated the signal propagation in single intraretinal axons as well as characteristic activity features of RGCs in a naive, a degenerative or a regenerative state in ex vivo retinae one week after either optic nerve cut alone (ONC or additional inflammatory stimulation (ONC+IS. Recordings of single RGCs using high-density microelectrode arrays demonstrate that the mean intraretinal axonal conduction velocity significantly decreased within the first week after ONC. In contrast, when ONC was accompanied by regenerative Pam3Cys treatment the mean intraretinal velocity was undistinguishable from control RGCs, indicating a protective effect on the proximal axon. Spontaneous RGC activity decreased for the two most numerous RGC types (ON- and OFF-sustained cells within one post-operative week, but did not significantly increase in RGCs after inflammatory stimulation. The analysis of light-induced activity revealed that RGCs in ONC animals respond on average later and with fewer spikes than control RGCs. IS significantly improved the responsiveness of the two studied RGC types.These results show that the transformation into a regenerative state by IS preserves, at least transiently, the physiological functional properties of injured RGCs.

  11. Repetitive Measurements of Physiological pH by Implantable Optical Sensors in Muscles of adult Danio rerio: Preliminary Results

    OpenAIRE

    E.V. Borvinskaya; A.N. Gurkov; E.P. Shchapova; B.K. Baduev; I.A. Belousova; Meglinski, I. V.; M.A. Timofeyev

    2016-01-01

    Encapsulated optical sensors are promising tool for measurements of physiological parameters inside living organisms. In the present study we tested the possibility to apply encapsulated fluorescent sensors to measure pH in muscles of adult Danio rerio. Right after injection, the sensors detect slightly acidic pH, while after 3 h pH becomes significantly more alkaline. These fluctuations are probably related to cell damage during the injection and further wound repair. After 20 h pH of inters...

  12. In vivo optical imaging of physiological responses to photostimulation in human photoreceptors

    CERN Document Server

    Hillmann, Dierck; Pfäffle, Clara; Sudkamp, Helge; Franke, Gesa; Hüttmann, Gereon

    2016-01-01

    Non-invasive functional imaging of molecular and cellular processes of vision is expected to have immense impact on research and clinical diagnostics. Although suitable intrinsic optical signals (IOS) have been observed ex vivo and in immobilized animals in vivo, it was so far not possible to obtain convincing IOS of photoreceptor activity in humans in vivo. Here, we observed spatially and temporally clearly resolved changes in the optical path length of the photoreceptor outer segment as response to an optical stimulus in living human. To obtain these changes, we evaluated phase data of a parallelized and computationally aberration-corrected optical coherence tomography (OCT) system. The non-invasive detection of optical path length changes shows the neuronal photoreceptor activity of single cones in living human retina, and, more importantly, it provides a new diagnostic option in ophthalmology and neurology and could give new insights into visual phototransduction in humans.

  13. Diffuse optical systems and methods to image physiological changes of the brain in response to focal TBI (Conference Presentation)

    Science.gov (United States)

    Abookasis, David; Volkov, Boris; Kofman, Itamar

    2017-02-01

    During the last four decades, various optical techniques have been proposed and intensively used for biomedical diagnosis and therapy both in animal model and in human. These techniques have several advantages over the traditional existing methods: simplicity in structure, low-cost, easy to handle, portable, can be used repeatedly over time near the patient bedside for continues monitoring, and offer high spatiotemporal resolution. In this work, we demonstrate the use of two optical imaging modalities namely, spatially modulated illumination and dual-wavelength laser speckle to image the changes in brain tissue chromophores, morphology, and metabolic before, during, and after the onset of focal traumatic brain injury in intact mouse head (n=15). Injury was applied in anesthetized mice by weight-drop apparatus using 50gram metal rod striking the mouse's head. Following data analysis, we show a series of hemodynamic and structural changes over time including higher deoxyhemoglobin, reduction in oxygen saturation and blood flow, cell swelling, etc., in comparison with baseline measurements. In addition, to validate the monitoring of cerebral blood flow by the imaging system, measurements with laser Doppler flowmetry were also performed (n=5), which confirmed reduction in blood flow following injury. Overall, our result demonstrates the capability of diffuse optical modalities to monitor and map brain tissue optical and physiological properties following brain trauma.

  14. Automated segmentation of the optic disc from stereo color photographs using physiologically plausible features

    NARCIS (Netherlands)

    Abramoff, M.D.; Alward, W.L.M.; Greenlee, E.C.; Shuba, L.; Kim, Chan Y.; Fingert, J.H.; Kwon, Y.H.

    2007-01-01

    PURPOSE. To evaluate a novel automated segmentation algorithm for cup-to-disc segmentation from stereo color photographs of patients with glaucoma for the measurement of glaucoma progression. METHODS. Stereo color photographs of the optic disc were obtained by using a fixed stereo-base fundus

  15. Comparison of cobinamide to hydroxocobalamin in reversing cyanide physiologic effects in rabbits using diffuse optical spectroscopy monitoring

    Science.gov (United States)

    Brenner, Matthew; Mahon, Sari B.; Lee, Jangwoen; Kim, Jae; Mukai, David; Goodman, Seth; Kreuter, Kelly A.; Ahdout, Rebecca; Mohammad, Othman; Sharma, Vijay S.; Blackledge, William; Boss, Gerry R.

    2010-01-01

    Our purpose is to compare cobinamide to hydroxocobalamin in reversing cyanide (CN)-induced physiologic effects in an animal model using diffuse optical spectroscopy (DOS). Cyanide poisoning is a major threat worldwide. Cobinamide is a novel molecule that can bind two molecules of cyanide, has a much higher binding affinity than hydroxocobalamin, and is more water soluble. We investigated the ability of equimolar doses of cobinamide and hydroxocobalamin to reverse the effects of cyanide exposure in an animal model monitored continuously by DOS. Cyanide toxicity was induced in 16 New Zealand white rabbits by intravenous infusion. Animals were divided into three groups: controls (n=5) received saline following cyanide, hydroxocobalamin (N=6) following cyanide, and cobinamide (N=5) following cyanide. Cobinamide caused significantly faster and more complete recovery of oxy- and deoxyhemoglobin concentrations in cyanide-exposed animals than hydroxocobalamin- or saline-treated animals, with a recovery time constant of 13.8+/-7.1 min compared to 75.4+/-25.1 and 76.4+/-42.7 min, for hydroxocobalamin- and saline-treated animals, respectively (p<0.0001). This study indicates that cobinamide more rapidly and completely reverses the physiologic effects of cyanide than equimolar doses of cobalamin at the dose used in this study, and CN effects and response can be followed noninvasively using DOS.

  16. Physiologic aspects of designing hidden information systems based on visible optical radiation

    Directory of Open Access Journals (Sweden)

    Brailovskii V. V.

    2015-02-01

    Full Text Available The paper presents the methodology and experimental results of the study of human eye sensitivity in central and peripheral vision field to the visible light pulses. The experimental results show that transmission systems based on visible rays can work in hidden mode. Conditions providing hidden transmission differ significantly for day and night light levels. At low light levels (at night the non-perceptive nature of the pulsed light which is applied in the information transfer process should be used. In this case an optical transmitter is perceived as «usual» illuminant. In daylight, light pulse can be invisible at certain values of duration and frequency of the light pulses for central and peripheral vision. For example, light pulses with the duration of 5•10–6 s in the range from 20 to 200 Hz are «invisible».

  17. Physiological optics, cognition and emotion: a novel look at the early work of Wilhelm Wundt.

    Science.gov (United States)

    Wassmann, Claudia

    2009-04-01

    The German physiologist Wilhelm Wundt, who later founded experimental psychology, arguably developed the first modern scientific conception of emotion. In the first edition of Vorlesungen über die Menschen- und Thierseele (Lectures on human and animal psychology), which was published in 1863, Wundt tried to establish that emotions were essential parts of rational thought. In fact, he considered them unconscious steps of decision-making that were implied in all processes of conscious thought. His early work deserves attention not only because it is the attempt to conceptualize cognition and emotion strictly from a neural point of view but also because it represents the very foundation of the debate about the nature of emotion that revolved around William James' theory of emotion during the 1890s. However, this aspect of his work is little known because scholars who have analyzed Wundt's work focused on his late career. Furthermore, historical analysis interpreted Wundt's work within a philosophical framework, rather than placing it in the context of German medical and physiological research in which it belongs. In addition, Wundt's early works are hardly available to an English speaking audience because they were never translated.

  18. Ultrasensitive detection in optically dense physiological media: applications to fast reliable biological assays

    Science.gov (United States)

    Matveeva, Evgenia G.; Gryczynski, Ignacy; Berndt, Klaus W.; Lakowicz, Joseph R.; Goldys, Ewa; Gryczynski, Zygmunt

    2006-02-01

    We present a novel approach for performing fluorescence immunoassay in serum and whole blood using fluorescently labeled anti-rabbit IgG. This approach, which is based on Surface Plasmon-Coupled Emission (SPCE), provides increased sensitivity and substantial background reduction due to exclusive selection of the signal from the fluorophores located near a bio-affinity surface. Effective coupling range for SPCE is only couple of hundred nanometers from the metallic surface. Excited fluorophores outside the coupling layer do not contribute to SPCE, and their free-space emission is not transmitted through the opaque metallic film into the glass substrate. An antigen (rabbit IgG) was adsorbed to a slide covered with a thin silver metal layer, and the SPCE signal from the fluorophore-labeled anti-rabbit antibody, binding to the immobilized antigen, was detected. The effect of the sample matrix (buffer, human serum, or human whole blood) on the end-point immunoassay SPCE signal is discussed. The kinetics of binding could be monitored directly in whole blood or serum. The results showed that human serum and human whole blood attenuate the SPCE end-point signal and the immunoassay kinetic signal only approximately 2- and 3-fold, respectively (compared to buffer), resulting in signals that are easily detectable even in whole blood. The high optical absorption of the hemoglobin can be tolerated because only fluorophores within a couple of hundred nanometers from the metallic film contribute to SPCE. Both glass and plastic slides can be used for SPCE-based assays. We believe that SPCE has the potential of becoming a powerful approach for performing immunoassays based on surface-bound analytes or antibodies for many biomarkers directly in dense samples such as whole blood, without any need for washing steps.

  19. Arctic Tundra Vegetation Functional Types Based on Photosynthetic Physiology and Optical Properties

    Science.gov (United States)

    Huemmrich, Karl Fred; Gamon, John A.; Tweedie, Craig E.; Campbell, Petya K. Entcheva; Landis, David R.; Middleton, Elizabeth M.

    2013-01-01

    Non-vascular plants (lichens and mosses) are significant components of tundra landscapes and may respond to climate change differently from vascular plants affecting ecosystem carbon balance. Remote sensing provides critical tools for monitoring plant cover types, as optical signals provide a way to scale from plot measurements to regional estimates of biophysical properties, for which spatial-temporal patterns may be analyzed. Gas exchange measurements were collected for pure patches of key vegetation functional types (lichens, mosses, and vascular plants) in sedge tundra at Barrow, AK. These functional types were found to have three significantly different values of light use efficiency (LUE) with values of 0.013 plus or minus 0.0002, 0.0018 plus or minus 0.0002, and 0.0012 plus or minus 0.0001 mol C mol (exp -1) absorbed quanta for vascular plants, mosses and lichens, respectively. Discriminant analysis of the spectra reflectance of these patches identified five spectral bands that separated each of these vegetation functional types as well as nongreen material (bare soil, standing water, and dead leaves). These results were tested along a 100 m transect where midsummer spectral reflectance and vegetation coverage were measured at one meter intervals. Along the transect, area-averaged canopy LUE estimated from coverage fractions of the three functional types varied widely, even over short distances. The patch-level statistical discriminant functions applied to in situ hyperspectral reflectance data collected along the transect successfully unmixed cover fractions of the vegetation functional types. The unmixing functions, developed from the transect data, were applied to 30 m spatial resolution Earth Observing-1 Hyperion imaging spectrometer data to examine variability in distribution of the vegetation functional types for an area near Barrow, AK. Spatial variability of LUE was derived from the observed functional type distributions. Across this landscape, a

  20. Comparison of cobinamide to hydroxocobalamin in reversing cyanide physiologic effects in rabbits using diffuse optical spectroscopy monitoring

    Science.gov (United States)

    Brenner, Matthew; Mahon, Sari B.; Lee, Jangwoen; Kim, Jae; Mukai, David; Goodman, Seth; Kreuter, Kelly A.; Ahdout, Rebecca; Mohammad, Othman; Sharma, Vijay S.; Blackledge, William; Boss, Gerry R.

    2010-01-01

    Our purpose is to compare cobinamide to hydroxocobalamin in reversing cyanide (CN)–induced physiologic effects in an animal model using diffuse optical spectroscopy (DOS). Cyanide poisoning is a major threat worldwide. Cobinamide is a novel molecule that can bind two molecules of cyanide, has a much higher binding affinity than hydroxocobalamin, and is more water soluble. We investigated the ability of equimolar doses of cobinamide and hydroxocobalamin to reverse the effects of cyanide exposure in an animal model monitored continuously by DOS. Cyanide toxicity was induced in 16 New Zealand white rabbits by intravenous infusion. Animals were divided into three groups: controls (n=5) received saline following cyanide, hydroxocobalamin (N=6) following cyanide, and cobinamide (N=5) following cyanide. Cobinamide caused significantly faster and more complete recovery of oxy- and deoxyhemoglobin concentrations in cyanide-exposed animals than hydroxocobalamin- or saline-treated animals, with a recovery time constant of 13.8±7.1 min compared to 75.4±25.1 and 76.4±42.7 min, for hydroxocobalamin- and saline-treated animals, respectively (pcyanide than equimolar doses of cobalamin at the dose used in this study, and CN effects and response can be followed noninvasively using DOS. PMID:20210475

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  2. [Diagnostic Precision of the Confocal Scanning Laser Ophthalmoscopy in the Large Optic Disc with Physiological Excavation - a Long-Term Study].

    Science.gov (United States)

    Koch, Eva Charlotte; Plange, Niklas; Fuest, Matthias; Schimitzek, Hannah; Kuerten, David

    2017-07-06

    We repeatedly examined 17 subjects with presumed bilateral physiological excavation labeled as pathological and/or borderline via HRT to verify the diagnosis of physiological cupping or to monitor the long-term progression into normal tension glaucoma. Patients and Methods 17 Subjects with presumed bilateral physiological cupping and large optic discs were included in this long-term follow-up study. All subjects underwent regular detailed ophthalmologic examinations, including intraocular pressure measurement via Goldmann applanation tonometry (GAT), retinal nerve fiber layer imaging via optical coherence tonometry (OCT) and visual field testing and optic disc imaging using the HRT. Glaucomatous progression was identified using the HRT's tools (stereometric trend analysis [STA] and topographic change analysis [TCA]). Results In the initial examination, all 17 subjects were classified as "pathological", by the HRT's Moorfield's Regression Analysis (MRA). Over the observation period of 9.2 ± 5 years, only 1 of the 17 subjects showed an ensured conversion to normal tension glaucoma with glaucomatous visual field defects. The remaining 16 subjects show no visual field defects to date. STA showed significant changes in 3 subjects alone, in 1 subject TCA showed a significant change alone, and in 1 subject both analyses showed a progressive change. Conclusion After 9 years of regular examinations, 16 of the 17 subjects that were classified as "pathological" using MRA showed no glaucomatous visual field defects. In 5 out of these 16 subjects, progressive changes of the optic disc could be recorded via HRT. Therefore, the diagnostic precision of the HRT measurements seems to be limited in patients with large discs and physiological cupping. Georg Thieme Verlag KG Stuttgart · New York.

  3. Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures.

    Science.gov (United States)

    Dziuda, Łukasz

    2015-01-01

    The issues involved with recording vital functions in the magnetic resonance imaging (MRI) environment using fiber-optic sensors are considered in this paper. Basic physiological parameters, such as respiration and heart rate, are fundamental for predicting the risk of anxiety, panic, and claustrophobic episodes in patients undergoing MRI examinations. Electronic transducers are generally hazardous to the patient and are prone to erroneous operation in heavily electromagnetically penetrated MRI environments; however, nonmetallic fiber-optic sensors are inherently immune to electromagnetic effects and will be crucial for acquiring the above-mentioned physiological parameters. Forty-seven MRI-tested or potentially MRI-compatible sensors have appeared in the literature over the last 20 years. The author classifies these sensors into several categories and subcategories, depending on the sensing element placement, method of application, and measure and type. The author includes five in-house-designed fiber Bragg grating based sensors and shares experience in acquiring physiological measurements during MRI scans. This paper aims to systematize the knowledge of fiber-optic techniques for recording life functions and to indicate the current directions of development in this area.

  4. Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures

    Science.gov (United States)

    Dziuda, Łukasz

    2015-01-01

    The issues involved with recording vital functions in the magnetic resonance imaging (MRI) environment using fiber-optic sensors are considered in this paper. Basic physiological parameters, such as respiration and heart rate, are fundamental for predicting the risk of anxiety, panic, and claustrophobic episodes in patients undergoing MRI examinations. Electronic transducers are generally hazardous to the patient and are prone to erroneous operation in heavily electromagnetically penetrated MRI environments; however, nonmetallic fiber-optic sensors are inherently immune to electromagnetic effects and will be crucial for acquiring the above-mentioned physiological parameters. Forty-seven MRI-tested or potentially MRI-compatible sensors have appeared in the literature over the last 20 years. The author classifies these sensors into several categories and subcategories, depending on the sensing element placement, method of application, and measurand type. The author includes five in-house-designed fiber Bragg grating based sensors and shares experience in acquiring physiological measurements during MRI scans. This paper aims to systematize the knowledge of fiber-optic techniques for recording life functions and to indicate the current directions of development in this area.

  5. Construction of optical glucose nanobiosensor with high sensitivity and selectivity at physiological pH on the basis of organic-inorganic hybrid microgels.

    Science.gov (United States)

    Wu, Weitai; Zhou, Ting; Aiello, Michael; Zhou, Shuiqin

    2010-08-15

    A new class of optical glucose nanobiosensors with high sensitivity and selectivity at physiological pH is described. To construct these glucose nanobiosensors, the fluorescent CdS quantum dots (QDs), serving as the optical code, were incorporated into the glucose-sensitive poly(N-isopropylacrylamide-acrylamide-2-acrylamidomethyl-5-fluorophenylboronic acid) copolymer microgels, via both in situ growth method and "breathing in" method, respectively. The polymeric gel can adapt to surrounding glucose concentrations, and regulate the fluorescence of the embedded QDs, converting biochemical signals into optical signals. The gradual swelling of the gel would lead to the quenching of the fluorescence at the elevated glucose concentrations. The hybrid microgels displayed high selectivity to glucose over the potential primary interferents of lactate and human serum albumin in the physiologically important glucose concentration range. The stability, reversibility, and sensitivity of the organic-inorganic hybrid microgel-based biosensors were also systematically studied. These general properties of our nanobiosensors are well tunable under appropriate tailor on the hybrid microgels, in particular, simply through the change in the crosslinking degree of the microgels. The optical glucose nanobiosensors based on the organic-inorganic hybrid microgels have shown the potential for a third generation fluorescent biosensor.

  6. Study the efficacy of neuroprotective drugs on brain physiological properties during focal head injury using optical spectroscopy data analysis

    Science.gov (United States)

    Abookasis, David; Shochat, Ariel

    2016-03-01

    We present a comparative evaluation of five different neuroprotective drugs in the early phase following focal traumatic brain injury (TBI) in mouse intact head. The effectiveness of these drugs in terms of changes in brain tissue morphology and hemodynamic properties was experimentally evaluated through analysis of the optical absorption coefficient and spectral reduced scattering parameters in the range of 650-1000 nm. Anesthetized male mice (n=50 and n=10 control) were subjected to weight drop model mimics real life focal head trauma. Monitoring the effect of injury and neuroprotective drugs was obtained by using a diffuse reflectance spectroscopy system utilizing independent source-detector separation and location. Result indicates that administration of minocycline improve hemodynamic and reduced the level of tissue injury at an early phase post-injury while hypertonic saline treatment decrease brain water content. These findings highlight the heterogeneity between neuroprotective drugs and the ongoing controversy among researchers regarding which drug therapy is preferred for treatment of TBI. On the other hand, our results show the capability of optical spectroscopy technique to noninvasively study brain function following injury and drug therapy.

  7. Nasal Physiology

    Science.gov (United States)

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

  8. Biochemical and Physiological Characterization: Development & Apply Optical Methods for Charaterizing Biochemical Protein-Protein Interactions in MR-1

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Shimon

    2006-08-30

    The objectives of this report are to: Develop novel site-specific protein labeling chemistries for assaying protein-protein interactions in MR-1; and development of a novel optical acquisition and data analysis method for characterizing protein-protein interactions in MR-1 model systems. Our work on analyzing protein-protein interactions in MR-1 is divided in four areas: (1) expression and labeling of MR-1 proteins; (2) general scheme for site-specific fluorescent labeling of expressed proteins; (3) methodology development for monitoring protein-protein interactions; and (4) study of protein-protein interactions in MR-1. In this final report, we give an account for our advances in all areas.

  9. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  10. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  11. Adsorption of proteins at physiological concentrations on pegylated surfaces and the compatibilizing role of adsorbed albumin with respect to other proteins according to optical waveguide lightmode spectroscopy (OWLS).

    Science.gov (United States)

    Leclercq, Laurent; Modena, Enrico; Vert, Michel

    2013-01-01

    In literature, contacts between pegylated compounds and blood proteins are generally discussed in terms of excluded volume-related repulsions although adsorption and compatibility have been reported for some of these proteins occasionally. The major problem to investigate the behavior of blood in contact with pegylated surfaces is the complexity of the medium and especially the presence of albumin in large excess. In a model approach, optical waveguide lightmode spectroscopy (OWLS) was used to monitor the fate of albumin, fibrinogen, and γ-globulins at physiological concentrations in pH = 7.4 isotonic HEPES buffer after contact with SiTiO2 chips coated with diblock poly(DL-lactic acid)-block-poly(ethylene oxide)s and triblock poly(DL-lactic acid)-block-poly(ethylene oxide)-block-poly(DL-lactic acid) copolymers. Corresponding homopolymers were used as controls. The three protein systems were investigated separately, as a mixture and when added successively according to different orders of addition. OWLS gave access to the mass and the thickness of adhering protein layers that resist washing with HEPES buffer. Protein depositions were detected regardless of the presence of poly(ethylene glycol) segments on surfaces. Adsorption depended on the protein, on the surface and also on the presence of the other proteins. Unexpectedly any surface coated with a layer of adsorbed albumin prevented deposition of other proteins, including albumin itself. This outstanding finding suggests that it was the presence of albumin adsorbed on a surface, pegylated or not, that made that surface compatible with other proteins. As a consequence, dipping a device to be in contact with the blood of a patient in a solution of albumin could be a very simple means to avoid further protein deposition and maybe platelets adhesion after in vivo implantation.

  12. Physiological Networks: towards systems physiology

    Science.gov (United States)

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

    2012-02-01

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

  13. Mathematical physiology

    CERN Document Server

    Sneyd, James

    2009-01-01

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

  14. Reproductive physiology

    Science.gov (United States)

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

    1996-01-01

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

  15. Exercise physiology

    DEFF Research Database (Denmark)

    Kiens, Bente; Richter, Erik; Wojtaszewski, Jørgen

    2014-01-01

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

  16. Occupational physiology

    CERN Document Server

    Toomingas, Allan; Tornqvist, Ewa Wigaeus

    2011-01-01

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

  17. Physiological Acoustics

    Science.gov (United States)

    Young, Eric D.

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

  18. Space Physiology within an Exercise Physiology Curriculum

    Science.gov (United States)

    Carter, Jason R.; West, John B.

    2013-01-01

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

  19. Potassium physiology.

    Science.gov (United States)

    Thier, S O

    1986-04-25

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

  20. SERS detection of Biomolecules at Physiological pH via aggregation of Gold Nanorods mediated by Optical Forces and Plasmonic Heating

    Science.gov (United States)

    Fazio, Barbara; D'Andrea, Cristiano; Foti, Antonino; Messina, Elena; Irrera, Alessia; Donato, Maria Grazia; Villari, Valentina; Micali, Norberto; Maragò, Onofrio M.; Gucciardi, Pietro G.

    2016-06-01

    Strategies for in-liquid molecular detection via Surface Enhanced Raman Scattering (SERS) are currently based on chemically-driven aggregation or optical trapping of metal nanoparticles in presence of the target molecules. Such strategies allow the formation of SERS-active clusters that efficiently embed the molecule at the “hot spots” of the nanoparticles and enhance its Raman scattering by orders of magnitude. Here we report on a novel scheme that exploits the radiation pressure to locally push gold nanorods and induce their aggregation in buffered solutions of biomolecules, achieving biomolecular SERS detection at almost neutral pH. The sensor is applied to detect non-resonant amino acids and proteins, namely Phenylalanine (Phe), Bovine Serum Albumin (BSA) and Lysozyme (Lys), reaching detection limits in the μg/mL range. Being a chemical free and contactless technique, our methodology is easy to implement, fast to operate, needs small sample volumes and has potential for integration in microfluidic circuits for biomarkers detection.

  1. Single Cell Physiology

    Science.gov (United States)

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

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

  2. [Human physiology: kidney].

    Science.gov (United States)

    Natochin, Iu V

    2010-01-01

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

  3. Physiological effects in aromatherapy

    OpenAIRE

    2004-01-01

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

  4. Physiological Information Database (PID)

    Science.gov (United States)

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

  5. Chewing Over Physiology Integration

    Science.gov (United States)

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

    2005-01-01

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

  6. Chewing Over Physiology Integration

    Science.gov (United States)

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

    2005-01-01

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

  7. Physiological effects in aromatherapy

    Directory of Open Access Journals (Sweden)

    Tapanee Hongratanaworakit

    2004-01-01

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

  8. Doppler radar physiological sensing

    CERN Document Server

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

    2016-01-01

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

  9. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  10. [Adaptive optics for ophthalmology].

    Science.gov (United States)

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy.

  11. Three-dimensional printing physiology laboratory technology.

    Science.gov (United States)

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

    2013-12-01

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

  12. Advances in physiological computing

    CERN Document Server

    Fairclough, Stephen H

    2014-01-01

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

  13. Phun Week: Understanding Physiology

    Science.gov (United States)

    Limson, Mel; Matyas, Marsha Lakes

    2009-01-01

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

  14. Physiology of sport.

    Science.gov (United States)

    Maughan, Ron

    2007-07-01

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

  15. Physiological changes in pregnancy

    OpenAIRE

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

    2016-01-01

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

  16. [Principles of photoplethysmography and its applications in physiological measurements].

    Science.gov (United States)

    Shi, Ping; Yu, Hongliu

    2013-08-01

    The electro-optic technique of measuring the cardiovascular pulse wave, known as photoplethysmography (PPG), is clinically utilised for noninvasive characterisation of physiological components by dynamic monitoring of tissue optical absorption. Non-invasive PPG technology has been used in a wide range of individual, home or public health monitoring. The application of PPG has become one of the hot topics in the fields of biomedical engineering recently. This paper reviews the optical origins of PPG signal, the feature of PPG technology, the applications of PPG in physiological measurements and its development in the future.

  17. Fetal cardiovascular physiology.

    Science.gov (United States)

    Rychik, J

    2004-01-01

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

  18. Reproduction, physiology and biochemistry

    Science.gov (United States)

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

  19. Physiological mechanisms of prosociality.

    Science.gov (United States)

    Miller, Jonas G

    2017-08-12

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

  20. Optic glioma

    Science.gov (United States)

    Glioma - optic; Optic nerve glioma; Juvenile pilocytic astrocytoma; Brain cancer - optic glioma ... Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing ...

  1. Neuropeptide physiology in helminths.

    Science.gov (United States)

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

    2010-01-01

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

  2. Human physiology in space

    Science.gov (United States)

    Vernikos, J.

    1996-01-01

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

  3. Circadian physiology of metabolism.

    Science.gov (United States)

    Panda, Satchidananda

    2016-11-25

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

  4. Plant Physiology and Development

    DEFF Research Database (Denmark)

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

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

  5. The Face of Physiology

    Directory of Open Access Journals (Sweden)

    Paul White

    2008-10-01

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

  6. Starting Physiology: Bioelectrogenesis

    Science.gov (United States)

    Baptista, Vander

    2015-01-01

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

  7. Physiology of Sleep.

    Science.gov (United States)

    Carley, David W; Farabi, Sarah S

    2016-02-01

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

  8. Integrative Physiology of Fasting.

    Science.gov (United States)

    Secor, Stephen M; Carey, Hannah V

    2016-03-15

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

  9. Avian reproductive physiology

    Science.gov (United States)

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

    1995-01-01

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

  10. Physiological attributes of triathletes.

    Science.gov (United States)

    Suriano, R; Bishop, D

    2010-05-01

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

  11. Tuna comparative physiology.

    Science.gov (United States)

    Graham, Jeffrey B; Dickson, Kathryn A

    2004-11-01

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

  12. Neonatal cardiovascular physiology.

    Science.gov (United States)

    Hines, Michael H

    2013-11-01

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

  13. Vasogenic shock physiology

    Directory of Open Access Journals (Sweden)

    Sotiria Gkisioti

    2011-01-01

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

  14. Physiology of bile secretion

    Institute of Scientific and Technical Information of China (English)

    Alejandro Esteller

    2008-01-01

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

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

    Science.gov (United States)

    Ivanov, Plamen Ch.; Bartsch, Ronny P.

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

  16. [Physiology of the neuropeptides].

    Science.gov (United States)

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

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

  17. Physiology for engineers applying engineering methods to physiological systems

    CERN Document Server

    Chappell, Michael

    2016-01-01

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

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

    CERN Document Server

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

    2012-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

  20. Cardiovascular physiology and sleep.

    Science.gov (United States)

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

    2003-05-01

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

  1. Physiology of vitreous surgery.

    Science.gov (United States)

    Stefánsson, Einar

    2009-02-01

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

  2. Procedures of Exercise Physiology Laboratories

    Science.gov (United States)

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

    1998-01-01

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

  3. Conservation physiology of marine fishes

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  4. Starting physiology: bioelectrogenesis.

    Science.gov (United States)

    Baptista, Vander

    2015-12-01

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

  5. Hypertension: physiology and pathophysiology.

    Science.gov (United States)

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

    2012-10-01

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

  6. Physiology in Modelica

    Directory of Open Access Journals (Sweden)

    Marek Mateják

    2014-05-01

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

  7. Smolt physiology and endocrinology

    Science.gov (United States)

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

    2013-01-01

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

  8. Polyamines in plant physiology

    Science.gov (United States)

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

    1990-01-01

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

  9. DOSHIC PHYSIOLOGY OF SKIN

    Directory of Open Access Journals (Sweden)

    Shivprasad Chiplunkar

    2013-06-01

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

  10. Physiology of Volition

    Science.gov (United States)

    Hallett, Mark

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

  11. Optical processing

    Science.gov (United States)

    Gustafson, S. C.

    1985-12-01

    The technical contributions were as follows: (1) Optical parallel 2-D neighborhood processor and optical processor assessment technique; (2) High accuracy with moderately accurate components and optical fredkin gate architectures; (3) Integrated optical threshold computing, pipelined polynomial processor, and all optical analog/digital converter; (4) Adaptive optical associative memory model with attention; (5) Effectiveness of parallelism and connectivity in optical computers; (6) Optical systolic array processing using an integrated acoustooptic module; (7) Optical threshold elements and networks, holographic threshold processors, adaptive matched spatial filtering, and coherence theory in optical computing; (8) Time-varying optical processing for sub-pixel targets, optical Kalman filtering, and adaptive matched filtering; (9) Optical degrees of freedom, ultra short optical pulses, number representations, content-addressable-memory processors, and integrated optical Givens rotation devices; (10) Optical J-K flip flop analysis and interfacing for optical computers; (11) Matrix multiplication algorithms and limits of incoherent optical computers; (12) Architecture for machine vision with sensor fusion, pattern recognition functions, and neural net implementations; (13) Optical computing algorithms, architectures, and components; and (14) Dynamic optical interconnections, advantages and architectures.

  12. Optical highlighter molecules in neurobiology.

    Science.gov (United States)

    Datta, Sandeep Robert; Patterson, George H

    2012-02-01

    The development of advanced optical methods has played a key role in propelling progress in neurobiology. Genetically-encoded fluorescent molecules found in nature have enabled labeling of individual neurons to study their physiology and anatomy. Here we discuss the recent use of both native and synthetic optical highlighter proteins to address key problems in neurobiology, including questions relevant to synaptic function, neuroanatomy, and the organization of neural circuits.

  13. Causality in physiological signals.

    Science.gov (United States)

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

    2016-05-01

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

  14. Applied physiology of cycling.

    Science.gov (United States)

    Faria, I E

    1984-01-01

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

  15. Physiology of Visceral Pain.

    Science.gov (United States)

    Gebhart, G F; Bielefeldt, Klaus

    2016-09-15

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

  16. Assessing prebaccalaureate human physiology courses.

    Science.gov (United States)

    McCleary, V L

    1998-12-01

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

  17. Applied physiology of swimming.

    Science.gov (United States)

    Lavoie, J M; Montpetit, R R

    1986-01-01

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

  18. Cassava biology and physiology.

    Science.gov (United States)

    El-Sharkawy, Mabrouk A

    2004-11-01

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

  19. Understanding the physiology of schizophrenia.

    Science.gov (United States)

    Kirkpatrick, Brian

    2013-03-01

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

  20. Modern optics

    CERN Document Server

    Guenther, B D

    2015-01-01

    Modern Optics is a fundamental study of the principles of optics using a rigorous physical approach based on Maxwell's Equations. The treatment provides the mathematical foundations needed to understand a number of applications such as laser optics, fiber optics and medical imaging covered in an engineering curriculum as well as the traditional topics covered in a physics based course in optics. In addition to treating the fundamentals in optical science, the student is given an exposure to actual optics engineering problems such as paraxial matrix optics, aberrations with experimental examples, Fourier transform optics (Fresnel-Kirchhoff formulation), Gaussian waves, thin films, photonic crystals, surface plasmons, and fiber optics. Through its many pictures, figures, and diagrams, the text provides a good physical insight into the topics covered. The course content can be modified to reflect the interests of the instructor as well as the student, through the selection of optional material provided in append...

  1. Pregnancy: Comparison among Physiological and Pathological States

    Directory of Open Access Journals (Sweden)

    Angela Lucariello

    2014-01-01

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

  2. Medical electronics and physiological measurement

    Science.gov (United States)

    Cochrane, T.

    1989-07-01

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

  3. Survey of Departments of Physiology

    Science.gov (United States)

    Ganong, William F.

    1977-01-01

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

  4. Physiology of the fetal circulation.

    Science.gov (United States)

    Kiserud, Torvid

    2005-12-01

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

  5. Olfaction: anatomy, physiology and behavior

    OpenAIRE

    Benignus, Vernon A.; Prah, James D.

    1982-01-01

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

  6. Survey of Departments of Physiology

    Science.gov (United States)

    Ganong, William F.

    1977-01-01

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

  7. Optic Neuritis

    OpenAIRE

    1989-01-01

    Demyelinating optic neuritis is the most common cause of unilateral painful visual loss in the United States. Although patients presenting with demyelinating optic neuritis have favorable long-term visual prognosis, optic neuritis is the initial clinical manifestation of multiple sclerosis in 20% of patients. The Optic Neuritis Treatment Trial (ONTT) has helped stratify the risk of developing multiple sclerosis after the first episode of optic neuritis based on abnormal findings on brain MRI....

  8. Physiological Control of Germline Development

    OpenAIRE

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

    2013-01-01

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

  9. Seasonal changes in reindeer physiology

    OpenAIRE

    A. Reeta Pösö

    2005-01-01

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

  10. Physiologically relevant organs on chips.

    Science.gov (United States)

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

    2014-01-01

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

  11. Engineering Optics

    CERN Document Server

    Iizuka, Keigo

    2008-01-01

    Engineering Optics is a book for students who want to apply their knowledge of optics to engineering problems, as well as for engineering students who want to acquire the basic principles of optics. It covers such important topics as optical signal processing, holography, tomography, holographic radars, fiber optical communication, electro- and acousto-optic devices, and integrated optics (including optical bistability). As a basis for understanding these topics, the first few chapters give easy-to-follow explanations of diffraction theory, Fourier transforms, and geometrical optics. Practical examples, such as the video disk, the Fresnel zone plate, and many more, appear throughout the text, together with numerous solved exercises. There is an entirely new section in this updated edition on 3-D imaging.

  12. Wearable Optical Sensors

    KAUST Repository

    Ballard, Zachary S.

    2017-07-12

    The market for wearable sensors is predicted to grow to $5.5 billion by 2025, impacting global health in unprecedented ways. Optics and photonics will play a key role in the future of these wearable technologies, enabling highly sensitive measurements of otherwise invisible information and parameters about our health and surrounding environment. Through the implementation of optical wearable technologies, such as heart rate, blood pressure, and glucose monitors, among others, individuals are becoming more empowered to generate a wealth of rich, multifaceted physiological and environmental data, making personalized medicine a reality. Furthermore, these technologies can also be implemented in hospitals, clinics, point-of-care offices, assisted living facilities or even in patients’ homes for real-time, remote patient monitoring, creating more expeditious as well as resource-efficient systems. Several key optical technologies make such sensors possible, including e.g., optical fiber textiles, colorimetric, plasmonic, and fluorometric sensors, as well as Organic Light Emitting Diode (OLED) and Organic Photo-Diode (OPD) technologies. These emerging technologies and platforms show great promise as basic sensing elements in future wearable devices and will be reviewed in this chapter along-side currently existing fully integrated wearable optical sensors.

  13. Conservation physiology of animal migration.

    Science.gov (United States)

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

    2016-01-01

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

  14. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  15. Physiological Studies of Lactococcus lactis

    DEFF Research Database (Denmark)

    Hansen, Gunda

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

  16. Optical Solitons

    Science.gov (United States)

    Taylor, J. R.

    2005-08-01

    1. Optical solitons in fibres: theoretical review A. Hasegawa; 2. Solitons in optical fibres: an experimental account L. F. Mollenauer; 3. All-optical long-distance soliton-based transmission systems K. Smith and L. F. Mollenauer; 4. Nonlinear propagation effects in optical fibres: numerical studies K. J. Blow and N. J. Doran; 5. Soliton-soliton interactions C. Desem and P. L. Chu; 6. Soliton amplification in erbium-doped fibre amplifiers and its application to soliton communication M. Nakazawa; 7. Nonlinear transformation of laser radiation and generation of Raman solitons in optical fibres E. M. Dianov, A. B. Grudinin, A. M. Prokhorov and V. N. Serkin; 8. Generation and compression of femtosecond solitons in optical fibers P. V. Mamyshev; 9. Optical fibre solitons in the presence of higher order dispersion and birefringence C. R. Menyuk and Ping-Kong A. Wai; 10. Dark optical solitons A. M. Weiner; 11. Soliton Raman effects J. R. Taylor; Bibliography; Index.

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

    Science.gov (United States)

    Cheng, Hwee-Ming

    2010-01-01

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

  18. Optical biosensors

    OpenAIRE

    Damborský, Pavel; Švitel, Juraj; Katrlík, Jaroslav

    2016-01-01

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biose...

  19. Optical keyboard

    Science.gov (United States)

    Veligdan, James T.; Feichtner, John D.; Phillips, Thomas E.

    2001-01-01

    An optical keyboard includes an optical panel having optical waveguides stacked together. First ends of the waveguides define an inlet face, and opposite ends thereof define a screen. A projector transmits a light beam outbound through the waveguides for display on the screen as a keyboard image. A light sensor is optically aligned with the inlet face for sensing an inbound light beam channeled through the waveguides from the screen upon covering one key of the keyboard image.

  20. Optical developments for optogenetics.

    Science.gov (United States)

    Papagiakoumou, Eirini

    2013-10-01

    Brain intricacies and the difficulty that scientists encounter in revealing its function with standard approaches such as electrical stimulation of neurons have led to the exploration of new tools that enable the study of neural circuits in a remote and non-invasive way. To this end, optogenetics has initialised a revolution for neuroscience in the last decade by enabling simultaneous monitoring and stimulation of specific neuronal populations in intact brain preparations through genetically targeted expression of light sensitive proteins and molecular photoswitches. In addition to ongoing molecular probe development and optimisation, novel optical techniques hold immense potential to amplify and diversify the utility of optogenetic methods. Importantly, by improving the spatio-temporal resolution of light stimulation, neural circuits can be photoactivated in patterns mimicking endogenous physiological processes. The following synopsis addresses the possibilities and limitations of optical stimulation methods applied to and developed for activation of neuronal optogenetic tools.

  1. Optical interconnects

    CERN Document Server

    Chen, Ray T

    2006-01-01

    This book describes fully embedded board level optical interconnect in detail including the fabrication of the thin-film VCSEL array, its characterization, thermal management, the fabrication of optical interconnection layer, and the integration of devices on a flexible waveguide film. All the optical components are buried within electrical PCB layers in a fully embedded board level optical interconnect. Therefore, we can save foot prints on the top real estate of the PCB and relieve packaging difficulty reduced by separating fabrication processes. To realize fully embedded board level optical

  2. Optical fibres

    CERN Document Server

    Geisler, J; Boutruche, J P

    1986-01-01

    Optical Fibers covers numerous research works on the significant advances in optical fibers, with particular emphasis on their application.This text is composed of three parts encompassing 15 chapters. The first part deals with the manufacture of optical fibers and the materials used in their production. The second part describes optical-fiber connectors, terminals and branches. The third part is concerned with the major optoelectronic components encountered in optical-communication systems.This book will be of value to research scientists, engineers, and patent workers.

  3. Nonlinear optics

    CERN Document Server

    Boyd, Robert W

    2013-01-01

    Nonlinear Optics is an advanced textbook for courses dealing with nonlinear optics, quantum electronics, laser physics, contemporary and quantum optics, and electrooptics. Its pedagogical emphasis is on fundamentals rather than particular, transitory applications. As a result, this textbook will have lasting appeal to a wide audience of electrical engineering, physics, and optics students, as well as those in related fields such as materials science and chemistry.Key Features* The origin of optical nonlinearities, including dependence on the polarization of light* A detailed treatment of the q

  4. Electronic Textbook in Human Physiology.

    Science.gov (United States)

    Broering, Naomi C.; Lilienfield, Lawrence S.

    1994-01-01

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

  5. Exercise Effects on Sleep Physiology

    Directory of Open Access Journals (Sweden)

    Sunao eUchida

    2012-04-01

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

  6. Physiological aspects of paired stimulation

    NARCIS (Netherlands)

    Meijler, F.L.; Durrer, D.

    1966-01-01

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

  7. The Limits of Exercise Physiology

    DEFF Research Database (Denmark)

    Gabriel, Brendan M; Zierath, Juleen R

    2017-01-01

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

  8. Physiological specialization of Stagonospora nodorum

    Science.gov (United States)

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

  9. Physiological adaptation in desert birds

    NARCIS (Netherlands)

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

    2005-01-01

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

  10. Reproductive Physiology in Cetaceans (Review)

    OpenAIRE

    1996-01-01

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

  11. Applied physiology of water polo.

    Science.gov (United States)

    Smith, H K

    1998-11-01

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

  12. PHYSIOLOGIC BASIS OF NASAL OPERATIONS

    Science.gov (United States)

    Hilding, A. C.

    1950-01-01

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

  13. Physiological Monitoring in Diving Mammals

    Science.gov (United States)

    2015-09-30

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

  14. Network Physiology: Mapping interactions between complex physiological systems

    OpenAIRE

    Ivanov, Plamen Ch.

    2016-01-01

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

  15. Applied optics and optical design

    CERN Document Server

    Conrady, A E

    2011-01-01

    ""For the optical engineer it is an indispensable work."" - Journal, Optical Society of America""As a practical guide this book has no rival."" - Transactions, Optical Society""A noteworthy contribution,"" - Nature (London)Part I covers all ordinary ray-tracing methods, together with the complete theory of primary aberrations and as much of higher aberration as is needed for the design of telescopes, low-power microscopes and simple optical systems. Chapters: Fundamental Equations, Spherical Aberration, Physical Aspect of Optical Images, Chromatic Aberration, Design of Achromatic Object-Glass

  16. On optics of human meridians

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A new concept and its methodology for studying human meridians are presented based on rigorous and scientific observation on the objective existence of human meridians in view of biomedical optics. According to this methodology,the infrared radiant characteristics of acupuncture meridians over human body and the optical transport properties of light propagating along the meridian are reported. This study,thus,confirms the existence of acupuncture meridians,sheds new light on an approach to investigation of human meridians and offers a new perspective in understanding the potential meridian functions such as energy and information transfer and physiological regulation.

  17. On optics of human meridians

    Institute of Scientific and Technical Information of China (English)

    YANG HongQin; XIE ShuSen; LI Hui; WANG YuHua

    2009-01-01

    A new concept and its methodology for studying human meridians are presented based on rigorous and scientific observation on the objective existence of human meridians in view of biomedical optics. According to this methodology, the infrared radiant characteristics of acupuncture meridians over human body and the optical transport properties of light propagating along the meridian are reported. This study, thus, confirms the existence of acupuncture meridians, sheds new light on an approach to investigation of human meridians and offers a new perspective in understanding the potential meridian functions such as energy and information transfer and physiological regulation.

  18. PHYSIOLOGY OF ACID BASE BALANCE

    Directory of Open Access Journals (Sweden)

    Awati

    2014-12-01

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

  19. Anatomy and physiology of cisternostomy

    Institute of Scientific and Technical Information of China (English)

    Iype Cherian; Giovanni Grasso; Antonio Bernardo; Sunil Munakomi

    2016-01-01

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

  20. Optical electronics

    CERN Document Server

    Yariv, Amnon

    1991-01-01

    This classic text introduces engineering students to the first principles of major phenomena and devices of optoelectronics and optical communication technology. Yariv's "first principles" approach employs real-life examples and extensive problems. The text includes separate chapters on quantum well and semiconductor lasers, as well as phase conjugation and its applications. Optical fiber amplification, signal and noise considerations in optical fiber systems, laser arrays and distributed feedback lasers all are covered extensively in major sections within chapters.

  1. [Optic neuritis].

    Science.gov (United States)

    Wilhelm, H; Heine, C; Tonagel, F

    2014-11-01

    Optic neuritis is a frequent neuro-ophthalmological disease in which the diagnosis can be based on just a few symptoms and findings. It is not only important to differentiate from other optic nerve disorders but also to recognise special types of optic neuritis, which is mostly only possible during the course of the disease. This article presents a review of the current state in diagnosis and therapy from the authors' personal point of view.

  2. [C-peptide physiological effects].

    Science.gov (United States)

    Shpakov, A O; Granstrem, O K

    2013-02-01

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

  3. Neuronal responses to physiological stress

    Directory of Open Access Journals (Sweden)

    Konstantinos eKagias

    2012-10-01

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

  4. Physiology of psychogenic movement disorders.

    Science.gov (United States)

    Hallett, Mark

    2010-08-01

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

  5. Physiology of in vitro culture

    Directory of Open Access Journals (Sweden)

    Maria Jesús Cañal

    2001-01-01

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

  6. Physiological and pathological cardiac hypertrophy.

    Science.gov (United States)

    Shimizu, Ippei; Minamino, Tohru

    2016-08-01

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

  7. Dynamical compensation in physiological circuits.

    Science.gov (United States)

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

    2016-11-08

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

  8. Physiological Responses to Thermal Stress and Exercise

    Science.gov (United States)

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

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

  9. Opto-physiological modeling applied to photoplethysmographic cardiovascular assessment.

    Science.gov (United States)

    Hu, Sijung; Azorin-Peris, Vicente; Zheng, Jia

    2013-01-01

    This paper presents opto-physiological (OP) modeling and its application in cardiovascular assessment techniques based on photoplethysmography (PPG). Existing contact point measurement techniques, i.e., pulse oximetry probes, are compared with the next generation non-contact and imaging implementations, i.e., non-contact reflection and camera-based PPG. The further development of effective physiological monitoring techniques relies on novel approaches to OP modeling that can better inform the design and development of sensing hardware and applicable signal processing procedures. With the help of finite-element optical simulation, fundamental research into OP modeling of photoplethysmography is being exploited towards the development of engineering solutions for practical biomedical systems. This paper reviews a body of research comprising two OP models that have led to significant progress in the design of transmission mode pulse oximetry probes, and approaches to 3D blood perfusion mapping for the interpretation of cardiovascular performance.

  10. Opto-Physiological Modeling Applied to Photoplethysmographic Cardiovascular Assessment

    Directory of Open Access Journals (Sweden)

    Sijung Hu

    2013-01-01

    Full Text Available This paper presents opto-physiological (OP modeling and its application in cardiovascular assessment techniques based on photoplethysmography (PPG. Existing contact point measurement techniques, i.e., pulse oximetry probes, are compared with the next generation non-contact and imaging implementations, i.e., non-contact reflection and camera-based PPG. The further development of effective physiological monitoring techniques relies on novel approaches to OP modeling that can better inform the design and development of sensing hardware and applicable signal processing procedures. With the help of finite-element optical simulation, fundamental research into OP modeling of photoplethysmography is being exploited towards the development of engineering solutions for practical biomedical systems. This paper reviews a body of research comprising two OP models that have led to significant progress in the design of transmission mode pulse oximetry probes, and approaches to 3D blood perfusion mapping for the interpretation of cardiovascular performance.

  11. Optical Detectors

    Science.gov (United States)

    Tabbert, Bernd; Goushcha, Alexander

    Optical detectors are applied in all fields of human activities from basic research to commercial applications in communication, automotive, medical imaging, homeland security, and other fields. The processes of light interaction with matter described in other chapters of this handbook form the basis for understanding the optical detectors physics and device properties.

  12. Optic neuritis

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke; Roed, H; Sellebjerg, F

    2004-01-01

    To study the involvement of the chemokine receptor CXCR3 and its ligands (CXCL9/Mig, CXCL10/IP-10, CXCL11/ITAC) in optic neuritis (ON).......To study the involvement of the chemokine receptor CXCR3 and its ligands (CXCL9/Mig, CXCL10/IP-10, CXCL11/ITAC) in optic neuritis (ON)....

  13. Physiological Parameters Database for Older Adults

    Data.gov (United States)

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

  14. Optical biosensors

    Science.gov (United States)

    Damborský, Pavel; Švitel, Juraj

    2016-01-01

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biosensors, as well as interferometric, ellipsometric and reflectometric interference spectroscopy and surface-enhanced Raman scattering biosensors. The optical biosensors discussed here allow the sensitive and selective detection of a wide range of analytes including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. PMID:27365039

  15. Lagrangian optics

    CERN Document Server

    Lakshminarayanan, Vasudevan; Thyagarajan, K

    2002-01-01

    Ingeometrical optics, light propagation is analyzed in terms of light rays which define the path of propagation of light energy in the limitofthe optical wavelength tending to zero. Many features oflight propagation can be analyzed in terms ofrays,ofcourse, subtle effects near foci, caustics or turning points would need an analysis based on the wave natureoflight. Allofgeometric optics can be derived from Fermat's principle which is an extremum principle. The counterpart in classical mechanics is of course Hamilton's principle. There is a very close analogy between mechanics ofparticles and optics oflight rays. Much insight (and useful results) can be obtained by analyzing these analogies. Asnoted by H. Goldstein in his book Classical Mechanics (Addison Wesley, Cambridge, MA, 1956), classical mechanics is only a geometrical optics approximation to a wave theory! In this book we begin with Fermat's principle and obtain the Lagrangian and Hamiltonian pictures of ray propagation through various media. Given the ...

  16. Upper gastrointestinal physiology and diseases.

    Science.gov (United States)

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

    2015-06-01

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

  17. Fish cardiovascular physiology and disease.

    Science.gov (United States)

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

    2009-01-01

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

  18. Physiologic mastectomy via flank laparotomy.

    Science.gov (United States)

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

    2008-11-01

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

  19. Bengt Saltin and exercise physiology: a perspective.

    Science.gov (United States)

    Joyner, Michael J

    2017-01-01

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

  20. Electrocyte physiology: 50 years later.

    Science.gov (United States)

    Markham, Michael R

    2013-07-01

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

  1. The glycemic index: physiological significance.

    Science.gov (United States)

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

    2009-08-01

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

  2. Physiological Effects of Touching Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

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

  3. Nonlinear optics

    CERN Document Server

    Bloembergen, Nicolaas

    1996-01-01

    Nicolaas Bloembergen, recipient of the Nobel Prize for Physics (1981), wrote Nonlinear Optics in 1964, when the field of nonlinear optics was only three years old. The available literature has since grown by at least three orders of magnitude.The vitality of Nonlinear Optics is evident from the still-growing number of scientists and engineers engaged in the study of new nonlinear phenomena and in the development of new nonlinear devices in the field of opto-electronics. This monograph should be helpful in providing a historical introduction and a general background of basic ideas both for expe

  4. Optical holography

    CERN Document Server

    Collier, Robert

    2013-01-01

    Optical Holography deals with the use of optical holography to solve technical problems, with emphasis on the properties of holograms formed with visible light. Topics covered include the Fourier transform, propagation and diffraction, pulsed-laser holography, and optical systems with spherical lenses. A geometric analysis of point-source holograms is also presented, and holograms and hologram spatial filters formed with spatially modulated reference waves are described. This book is comprised of 20 chapters and begins with an introduction to concepts that are basic to understanding hologr

  5. Tunable nanowire nonlinear optical probe

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yuri; Pauzauskie, Peter J.; Radenovic, Aleksandra; Onorato, Robert M.; Saykally, Richard J.; Liphardt, Jan; Yang, Peidong

    2008-02-18

    One crucial challenge for subwavelength optics has been thedevelopment of a tunable source of coherent laser radiation for use inthe physical, information, and biological sciences that is stable at roomtemperature and physiological conditions. Current advanced near-fieldimaging techniques using fiber-optic scattering probes1,2 have alreadyachieved spatial resolution down to the 20-nm range. Recently reportedfar-field approaches for optical microscopy, including stimulatedemission depletion (STED)3, structured illumination4, and photoactivatedlocalization microscopy (PALM)5, have also enabled impressive,theoretically-unlimited spatial resolution of fluorescent biomolecularcomplexes. Previous work with laser tweezers6-8 has suggested the promiseof using optical traps to create novel spatial probes and sensors.Inorganic nanowires have diameters substantially below the wavelength ofvisible light and have unique electronic and optical properties9,10 thatmake them prime candidates for subwavelength laser and imagingtechnology. Here we report the development of an electrode-free,continuously-tunable coherent visible light source compatible withphysiological environments, from individual potassium niobate (KNbO3)nanowires. These wires exhibit efficient second harmonic generation(SHG), and act as frequency converters, allowing the local synthesis of awide range of colors via sum and difference frequency generation (SFG,DFG). We use this tunable nanometric light source to implement a novelform of subwavelength microscopy, in which an infrared (IR) laser is usedto optically trap and scan a nanowire over a sample, suggesting a widerange of potential applications in physics, chemistry, materials science,and biology.

  6. Network Physiology: How Organ Systems Dynamically Interact.

    Science.gov (United States)

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

    2015-01-01

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

  7. Network Physiology: How Organ Systems Dynamically Interact.

    Directory of Open Access Journals (Sweden)

    Ronny P Bartsch

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

  8. Optical Spectroscopy

    DEFF Research Database (Denmark)

    Thyrhaug, Erling

    The work presented in this thesis is broadly concerned with how complexation reactions and molecular motion can be characterized with the standard techniques in optical spectroscopy. The thesis aims to show a relatively broad range of methods for probing physico-chemical properties in fluorophore...... containing systems and are characterized using techniques in optical spectroscopy. Of the standard techniques in optical spectroscopy, particular attention has been paid to those based on time-resolved measurements and polarization, which is reflected in the experiment design in the projects. Not all...... reactions by optical spectroscopy. In project 1 simple steady-state absorption and fluorescence spectroscopy is used to determine the stoichiometries and equilibrium constants in the inclusion complex formation between cyclodextrins and derivatives of the water-insoluble oligo(phenylene vinylene) in aqueous...

  9. Optical medical imaging: from glass to man

    Science.gov (United States)

    Bradley, Mark

    2016-11-01

    A formidable challenge in modern respiratory healthcare is the accurate and timely diagnosis of lung infection and inflammation. The EPSRC Interdisciplinary Research Collaboration (IRC) `Proteus' seeks to address this challenge by developing an optical fibre based healthcare technology platform that combines physiological sensing with multiplexed optical molecular imaging. This technology will enable in situ measurements deep in the human lung allowing the assessment of tissue function and characterization of the unique signatures of pulmonary disease and is illustrated here with our in-man application of Optical Imaging SmartProbes and our first device Versicolour.

  10. Quantum optics

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund

    2013-01-01

    Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves.......Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves....

  11. Quantum optics

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund

    2013-01-01

    Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves.......Further sensitivity improvements are required before advanced optical interferometers will be able to measure gravitational waves. A team has now shown that introducing quantum squeezing of light may help to detect these elusive waves....

  12. Ocean optics

    Energy Technology Data Exchange (ETDEWEB)

    Spinard, R.W.; Carder, K.L.; Perry, M.J.

    1994-12-31

    This volume is the twenty fifth in the series of Oxford Monographs in Geology and Geophysics. The propagation off light in the hydra-atmosphere systems is governed by the integral-differential Radiative Transfer Equation (RTE). Closure and inversion are the most common techniques in optical oceanography to understand the most basic principles of natural variability. Three types of closure are dealt with: scale closure, experimental closure, and instrument closure. The subject is well introduced by Spinard et al. in the Preface while Howard Gordon in Chapter 1 provides an in-depth introduction to the RTE and its inherent problems. Inherent and apparent optical properties are dealt with in Chapter 2 by John Kirk and the realities of optical closure are presented in the following chapter by Ronald Zaneveld. The balance of the papers in this volume is quite varied. The early papers deal in a very mathematical manner with the basics of radiative transfer and the relationship between inherent and optical properties. Polarization of sea water is discussed in a chapter that contains a chronological listing of discoveries in polarization, starting at about 1000 AD with the discovery of dichroic properties of crystals by the Vikings and ending with the demonstration of polarotaxis in certain marine organisms by Waterman in 1972. Chapter 12 on Raman scattering in pure water and the pattern recognition techniques presented in Chapter 13 on the optical effects of large particles may be of relevance to fields outside ocean optics.

  13. Neuronal responses to physiological stress

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  14. CH2 - Lighting and Physiology

    Directory of Open Access Journals (Sweden)

    Sergio Altomonte

    2012-11-01

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

  15. Children's physiological responses to childcare.

    Science.gov (United States)

    Vermeer, Harriet J; Groeneveld, Marleen G

    2017-06-01

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

  16. CH2 - Lighting and Physiology

    Directory of Open Access Journals (Sweden)

    Sergio Altomonte

    2012-11-01

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

  17. Optic nerve atrophy

    Science.gov (United States)

    Optic atrophy; Optic neuropathy ... There are many causes of optic atrophy. The most common is poor blood flow. This is called ischemic optic neuropathy. The problem most often affects older adults. The optic ...

  18. Ventricular hypertrophy--physiological mechanisms.

    Science.gov (United States)

    Vaughan Williams, E M

    1986-01-01

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

  19. Fruit Calcium: Transport and Physiology

    Directory of Open Access Journals (Sweden)

    Bradleigh eHocking

    2016-04-01

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

  20. Translational physiology: from molecules to public health.

    Science.gov (United States)

    Seals, Douglas R

    2013-07-15

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

  1. Multimodal optical phenotyping of cancer cells

    Science.gov (United States)

    Kastl, Lena; Budde, Björn; Isbach, Michael; Rommel, Christina; Kemper, Björn; Schnekenburger, Jürgen

    2015-03-01

    There is a growing interest in label-free, optical techniques like digital holographic microscopy (DHM) and optical cell stretching, since the interaction with samples is minimized. Because optical manipulation strongly depends on the optical and physiological properties of the investigated material, we combined the usage of these methods for the characterization of pancreatic tumor cells. Our results demonstrate that cells of distinct differentiation levels, or different expression in only one protein, show differences in their deformability. Additionally, the DHM results showed only few variations in the refractive index, indicating that it does not significantly influence the results of the optical cell stretching. Thus, the combined usage of the two technologies represents a promising new approach for tumor cell characterization.

  2. Intragroup Emotions: Physiological Linkage and Social Presence

    Science.gov (United States)

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

    2016-01-01

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

  3. Intragroup emotions: physiological linkage and social presence

    Directory of Open Access Journals (Sweden)

    Simo eJärvelä

    2016-02-01

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

  4. Wireless Sensor Network for Wearable Physiological Monitoring

    OpenAIRE

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

    2008-01-01

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

  5. Optical memory

    Science.gov (United States)

    Mao, Samuel S; Zhang, Yanfeng

    2013-07-02

    Optical memory comprising: a semiconductor wire, a first electrode, a second electrode, a light source, a means for producing a first voltage at the first electrode, a means for producing a second voltage at the second electrode, and a means for determining the presence of an electrical voltage across the first electrode and the second electrode exceeding a predefined voltage. The first voltage, preferably less than 0 volts, different from said second voltage. The semiconductor wire is optically transparent and has a bandgap less than the energy produced by the light source. The light source is optically connected to the semiconductor wire. The first electrode and the second electrode are electrically insulated from each other and said semiconductor wire.

  6. Semiconductor Optics

    CERN Document Server

    Klingshirn, Claus F

    2012-01-01

    This updated and enlarged new edition of Semiconductor Optics provides an introduction to and an overview of semiconductor optics from the IR through the visible to the UV, including linear and nonlinear optical properties, dynamics, magneto and electrooptics, high-excitation effects and laser processes, some applications, experimental techniques and group theory. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered extend from physics to materials science and optoelectronics. Significantly updated chapters add coverage of current topics such as electron hole plasma, Bose condensation of excitons and meta materials. Over 120 problems, chapter introductions and a detailed index make it the key textbook for graduate students in physics. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered ...

  7. CODEX optics

    Science.gov (United States)

    Delabre, Bernard; Manescau, Antonio

    2010-07-01

    CODEX is a high resolution spectrograph for the ESO E-ELT. A classical spectrograph can only achieve a resolution of about 120.000 on a 42 m telescope with extremely large echelle gratings and cameras. This paper describes in detail the optical concept of CODEX, which uses only optical elements size similar to those in current high resolution spectrographs. This design is based on slicers, anamorphic beams and slanted VPHG as cross dispersers. In this new version of the CODEX design, no special expensive materials as calcium fluoride or abnormal dispersion glasses are needed. The optical quality is excellent and compatible with 10K x 10K detectors with 10 μm pixels.

  8. Auditory pathways: anatomy and physiology.

    Science.gov (United States)

    Pickles, James O

    2015-01-01

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

  9. Virtual physiological human: training challenges.

    Science.gov (United States)

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

    2010-06-28

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

  10. Physiologic amputation: a case study.

    Science.gov (United States)

    Long, Jeri; Hall, Virginia

    2014-03-01

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

  11. Physiological demands of competitive basketball.

    Science.gov (United States)

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

    2009-06-01

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

  12. Seasonal changes in reindeer physiology

    Directory of Open Access Journals (Sweden)

    A. Reeta Pösö

    2005-04-01

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

  13. Obesity and Asthma: Physiological Perspective

    Directory of Open Access Journals (Sweden)

    Bill Brashier

    2013-01-01

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

  14. Statistical optics

    CERN Document Server

    Goodman, Joseph W

    2015-01-01

    This book discusses statistical methods that are useful for treating problems in modern optics, and the application of these methods to solving a variety of such problems This book covers a variety of statistical problems in optics, including both theory and applications.  The text covers the necessary background in statistics, statistical properties of light waves of various types, the theory of partial coherence and its applications, imaging with partially coherent light, atmospheric degradations of images, and noise limitations in the detection of light. New topics have been introduced i

  15. Reflective optics

    CERN Document Server

    Korsch, Dietrich

    1991-01-01

    This is the first book dedicated exclusively to all-reflective imaging systems. It is a teaching tool as well as a practical design tool for anyone who specializes in optics, particularly for those interested in telescopes, infrared, and grazing-incidence systems. The first part of the book describes a unified geometric optical theory of all-reflective imaging systems (from near-normal to grazing incidence) developed from basic principles. The second part discusses correction methods and a multitude of closed-form solutions of well-corrected systems, supplemented with many conventional and unc

  16. Optical profilometer

    Science.gov (United States)

    Wieloszyńska, Aleksandra; StrÄ kowski, Marcin

    2016-09-01

    The profilometry plays a huge role in the most fields of science and technology. It allows to measure the profile of the surface with high-resolution. This technique is used in the fields like optic, electronic, medicine, automotive, and much more. The aim of the current work was to design and build optical profilometer based on the interference phenomena. The developed device has been working with He-Ne laser (632.8 nm). The optical parts have been chosen in order to reach the sized 2.0 mm x 1.6 mm of scanning area. The setup of the profilometer is based on Twyman-Green interferometer. Therefore, the phase distribution of the backreflected light from measured surface is recorded. The measurements are carried out with the aid of multiframe algorithms. In this approach we have used the Hariharan algorithm to obtain the exact value of the recorded phase. During tests, which have been carried out in order to check the functionality of the device, the interference patterns have been recoded and processed in order to obtain the 3D profile of measured surface. In this contribution the setup of the optical system, as well as signal processing methods are going to be presented. The brief discussion about the advantages and disadvantages, and usefulness of this approach will be carried out.

  17. Diophantine Optics

    Science.gov (United States)

    Rouan, D.

    2016-09-01

    What I call Diophantine optics is the exploitation in optics of some remarkable algebraic relations between powers of integers. The name comes from Diophantus of Alexandria, a greek mathematician, known as the father of algebra. He studied polynomial equations with integer coefficients and integer solutions, called diophantine equations. Since constructive or destructive interferences are playing with optical path differences which are multiple integer (odd or even) of λ/2 and that the complex amplitude is a highly non-linear function of the optical path difference (or equivalently of the phase), one can understand that any Taylor development of this amplitude implies powers of integers. This is the link with Diophantine equations. We show how, especially in the field of interferometry, remarkable relations between powers of integers can help to solve several problems, such as achromatization of a phase shifter or deep nulling efficiency. It appears that all the research that was conducted in this frame of thinking, relates to the field of detection of exoplanets, a very active domain of astrophysics today.

  18. Optical Processing.

    Science.gov (United States)

    1985-12-31

    34perceptron" (F. Rosenblatt, Principles of Neurodynamics ), workers in the neural network field have been seeking to understand how neural networks can perform...Moscow). 13. F. Rosenblatt, Principles of Neurodynamics , (Spartan, 1962). 14. W. Stoner "Incoherent optical processing via spatially offset pupil

  19. Optical correlation

    NARCIS (Netherlands)

    Boden, J.A.

    1974-01-01

    A survey is given of the most common types of coherent optical correlators, which are classified as spatial plane correlators, frequency plane correlators and special reference correlators. Only the spatial plane correlators are dealt with rather thoroughly. Basic principles, some special features,

  20. Optical metrology

    CERN Document Server

    Gåsvik, Kjell J

    2003-01-01

    New material on computerized optical processes, computerized ray tracing, and the fast Fourier transform, Bibre-Bragg sensors, and temporal phase unwrapping.* New introductory sections to all chapters.* Detailed discussion on lasers and laser principles, including an introduction to radiometry and photometry.* Thorough coverage of the CCD camera.

  1. Pulsed Optics

    Science.gov (United States)

    Hirlimann, C.

    Optics is the field of physics which comprises knowledge on the interaction between light and matter. When the superposition principle can be applied to electromagnetic waves or when the properties of matter do not depend on the intensity of light, one speaks of linear optics. This situation occurs with regular light sources such as light bulbs, low-intensity light-emitting diodes and the sun. With such low-intensity sources the reaction of matter to light can be characterized by a set of parameters such as the index of refraction, the absorption and reflection coefficients and the orientation of the medium with respect to the polarization of the light. These parameters depend only on the nature of the medium. The situation changed dramatically after the development of lasers in the early sixties, which allowed the generation of light intensities larger than a kilowatt per square centimeter. Actual large-scale short-pulse lasers can generate peak powers in the petawatt regime. In that large-intensity regime the optical parameters of a material become functions of the intensity of the impinging light. In 1818 Fresnel wrote a letter to the French Academy of Sciences in which he noted that the proportionality between the vibration of the light and the subsequent vibration of matter was only true because no high intensities were available. The intensity dependence of the material response is what usually defines nonlinear optics.

  2. Physiological factors influencing capillary growth.

    Science.gov (United States)

    Egginton, S

    2011-07-01

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

  3. Aristotle on physiology of logos

    Directory of Open Access Journals (Sweden)

    Benéitez Prudencio, José Javier

    2011-06-01

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

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

  4. Optical Coherence and Quantum Optics

    CERN Document Server

    Mandel, Leonard

    1995-01-01

    This book presents a systematic account of optical coherence theory within the framework of classical optics, as applied to such topics as radiation from sources of different states of coherence, foundations of radiometry, effects of source coherence on the spectra of radiated fields, coherence theory of laser modes, and scattering of partially coherent light by random media. The book starts with a full mathematical introduction to the subject area and each chapter concludes with a set of exercises. The authors are renowned scientists and have made substantial contributions to many of the topi

  5. Cardiac anatomy and physiology: a review.

    Science.gov (United States)

    Gavaghan, M

    1998-04-01

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

  6. Design Projects in Human Anatomy & Physiology

    Science.gov (United States)

    Polizzotto, Kristin; Ortiz, Mary T.

    2008-01-01

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

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

    Science.gov (United States)

    Cooper, Michael; Dhawale, Shree; Mustafa, Ahmed

    2009-01-01

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

  8. Physiological Coping: A Model for Teaching Pathophysiology

    Science.gov (United States)

    Porth, Carol M.

    1977-01-01

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

  9. Physiology and biochemistry of honey bees

    Science.gov (United States)

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

  10. Towards Individualized Physiology Lecturing in Africa

    African Journals Online (AJOL)

    Dr Olaleye Samuel

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

  11. Physiological Bases of Bulimia, and Antidepressant Treatment.

    Science.gov (United States)

    Getzfeld, Andrew R.

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

  12. Design Projects in Human Anatomy & Physiology

    Science.gov (United States)

    Polizzotto, Kristin; Ortiz, Mary T.

    2008-01-01

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

  13. Wireless Sensor Network for Wearable Physiological Monitoring

    Directory of Open Access Journals (Sweden)

    P. S. Pandian

    2008-05-01

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

  14. Physiological Activity and Attitudes toward Disabled Persons.

    Science.gov (United States)

    Wesolowski, Michael D.; Deichmann, John

    1980-01-01

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

  15. Physiological characteristics of an aging Olympic athlete

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  16. Diffractive Optical Elements for Dynamic Optical Coupling

    Institute of Scientific and Technical Information of China (English)

    Changhe Zhou; Xin Zhao; Liren Liu

    2003-01-01

    Diffractive optical elements such as the complementary Dammann gratings are incorporated for dynamic optical fiber splitting and combining. Experimental results of 1′8 dynamic optical couplings are presented.

  17. Diffractive Optical Elements for Dynamic Optical Coupling

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Diffractive optical elements such as the complementary Dammann gratings are incorporated for dynamic optical fiber splitting and combining. Experimental results of 1×8 dynamic optical couplings are presented.

  18. Alterations in physiology and anatomy during pregnancy.

    Science.gov (United States)

    Tan, Eng Kien; Tan, Eng Loy

    2013-12-01

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

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

    Science.gov (United States)

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

    2002-01-01

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

  20. Visual-servoing optical microscopy

    Science.gov (United States)

    Callahan, Daniel E.; Parvin, Bahram

    2009-06-09

    The present invention provides methods and devices for the knowledge-based discovery and optimization of differences between cell types. In particular, the present invention provides visual servoing optical microscopy, as well as analysis methods. The present invention provides means for the close monitoring of hundreds of individual, living cells over time: quantification of dynamic physiological responses in multiple channels; real-time digital image segmentation and analysis; intelligent, repetitive computer-applied cell stress and cell stimulation; and the ability to return to the same field of cells for long-term studies and observation. The present invention further provides means to optimize culture conditions for specific subpopulations of cells.

  1. Applied optics and optical engineering v.9

    CERN Document Server

    Shannon, Robert

    1983-01-01

    Applied Optics and Optical Engineering, Volume IX covers the theories and applications of optics and optical engineering. The book discusses the basic algorithms for optical engineering; diffraction gratings, ruled and holographic; and recording and reading of information on optical disks. The text also describes the perfect point spread function; the multiple aperture telescope diffraction images; and the displays and simulators. Ophthalmic optics, as well as the canonical and real-space coordinates used in the theory of image formation are also encompassed. Optical engineers and students tak

  2. Soft optics in intelligent optical networks

    Science.gov (United States)

    Shue, Chikong; Cao, Yang

    2001-10-01

    In addition to the recent advances in Hard-optics that pushes the optical transmission speed, distance, wave density and optical switching capacity, Soft-optics provides the necessary intelligence and control software that reduces operational costs, increase efficiency, and enhances revenue generating services by automating optimal optical circuit placement and restoration, and enabling value-added new services like Optical VPN. This paper describes the advances in 1) Overall Hard-optics and Soft-optics 2) Layered hierarchy of Soft-optics 3) Component of Soft-optics, including hard-optics drivers, Management Soft-optics, Routing Soft-optics and System Soft-optics 4) Key component of Routing and System Soft-optics, namely optical routing and signaling (including UNI/NNI and GMPLS signaling). In summary, the soft-optics on a new generation of OXC's enables Intelligent Optical Networks to provide just-in-time service delivery and fast restoration, and real-time capacity management that eliminates stranded bandwidth. It reduces operational costs and provides new revenue opportunities.

  3. Optical aeronomy

    Science.gov (United States)

    Solomon, Stanley C.

    1991-01-01

    Optical measurements of thermospheric and ionospheric processes and their interpretation are reviewed and the chemical reactions and their effects on emissions are discussed. Also included are the phenomena which excite the airglow and aurora, i.e., the solar UV/EUV flux and auroral particle precipitation. Consideration is given to solar flux, atomic emissions, molecular emissions, hydrogen geocorona, and molecular oxygen and the green line nightglow.

  4. Applied Optics

    OpenAIRE

    Han, M; Wang, Anbo

    2004-01-01

    A straightforward theory is presented to accurately model the light inferences in a low-finesse multimode fiber extrinsic Fabry-Perot (FP) interferometer. The effect on the fringe visibility of the gap length, sensor structure imperfections, and modal power distributions is explored. The analysis is particularly useful in the design and optimization of sensors that use an extrinsic FP cavity as the sensing element. (C) 2004 Optical Society of America.

  5. Proposal of optical farming: development of several optical sensing instruments for agricultural use

    Science.gov (United States)

    Saito, Y.; Kobayashi, K.

    2013-05-01

    We propose the use of "Optical Farming," which is the leading application of all types of optical technologies, in agriculture and agriculture-related industries. This paper focuses on the optical sensing instruments named "Agriserver," "Agrigadget" and "LIFS Monitor" developed in our laboratory. They are considered major factors in utilizing Optical Farming. Agriserver is a sensor network system that uses the Internet to collect information on agricultural products growing in fields. Agrigadget contains several optical devices, such as a smartphone-based spectroscopic device and a hand framing camera. LIFS Monitor is an advanced monitoring instrument that makes it possible to obtain physiological information of living plants. They are strongly associated with information communication technology. Their field and data usage performance in agricultural industries are reported.

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

    Directory of Open Access Journals (Sweden)

    Brittany E Evans

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

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

    Science.gov (United States)

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

    2007-06-01

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

  8. Native spider silk as a biological optical fiber

    Science.gov (United States)

    Huby, N.; Vié, V.; Renault, A.; Beaufils, S.; Lefèvre, T.; Paquet-Mercier, F.; Pézolet, M.; Bêche, B.

    2013-03-01

    In this study, we demonstrate the use of eco-friendly native spider silk as an efficient optical fiber in air, highly bent fibers, and physiological liquid. We also integrated the silk filament in a photonic chip made of polymer microstructures fabricated by UV lithography. The molding process is non-destructive for silk and leads to an efficient micro-optical coupling between silk and synthetic optical structures. These optical performances combined with the unique biocompatibility, bioresorbability, flexibility, and tensile strength of silk filaments pave the way for new applications in biological media and for original biophotonic purposes.

  9. Conceptual Learning: Enhancing Student Understanding of Physiology

    Science.gov (United States)

    Waltz, Micah J.

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

  10. Power optics

    Energy Technology Data Exchange (ETDEWEB)

    Apollonov, V V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2014-02-28

    By using the theory we developed in the early 1970s, a broad range of phenomena is considered for an optical surface of a solid body that is exposed to radiation arbitrarily varying in time and producing temperature fields, thermoelastic stresses and thermal deformations on the surface layer. The examination is based on the relations (which are similar to Duhamel's integral formula from the theory of heat conduction) between the quantities characterising the thermal stress state in any nonstationary regimes of energy input into a solid. A peculiar feature of the analysis of the thermal stress state in this case consists in the fact that this relation comprises time as a parameter, which in turn is a consequence of incoherence of the quasi-stationary problem of thermoelasticity. This phenomenon is particularly important for the optics of high-power, high-pulse repetition rate lasers, which are being actively developed. In the review, we have recently published in Laser Physics, the thermal stress state of a solid is analysed. In this state, time is treated as an independent variable used in differentiation. Such an approach greatly reduces the applicability of the method. The review published contains data on the use of capillary porous structures made of various materials with different degrees of the surface development. Moreover, such structures can be efficiently employed to increase the heat exchange at a temperature below the boiling point of the coolant. In the present review we discuss the dependences of the limiting laser intensities on the duration of a pulse or a pulse train, corresponding to the three stages of the state of the reflecting surface and leading to unacceptable elastic deformations of the surface, to the plastic yield of the material accompanied by the formation of residual stresses and to the melting of the surface layer. We also analyse the problem of heat exchange in the surface layer with a liquid metal coolant pumped through it

  11. Power optics

    Science.gov (United States)

    Apollonov, V. V.

    2014-02-01

    By using the theory we developed in the early 1970s, a broad range of phenomena is considered for an optical surface of a solid body that is exposed to radiation arbitrarily varying in time and producing temperature fields, thermoelastic stresses and thermal deformations on the surface layer. The examination is based on the relations (which are similar to Duhamel's integral formula from the theory of heat conduction) between the quantities characterising the thermal stress state in any nonstationary regimes of energy input into a solid. A peculiar feature of the analysis of the thermal stress state in this case consists in the fact that this relation comprises time as a parameter, which in turn is a consequence of incoherence of the quasi-stationary problem of thermoelasticity. This phenomenon is particularly important for the optics of high-power, high-pulse repetition rate lasers, which are being actively developed. In the review, we have recently published in Laser Physics, the thermal stress state of a solid is analysed. In this state, time is treated as an independent variable used in differentiation. Such an approach greatly reduces the applicability of the method. The review published contains data on the use of capillary porous structures made of various materials with different degrees of the surface development. Moreover, such structures can be efficiently employed to increase the heat exchange at a temperature below the boiling point of the coolant. In the present review we discuss the dependences of the limiting laser intensities on the duration of a pulse or a pulse train, corresponding to the three stages of the state of the reflecting surface and leading to unacceptable elastic deformations of the surface, to the plastic yield of the material accompanied by the formation of residual stresses and to the melting of the surface layer. We also analyse the problem of heat exchange in the surface layer with a liquid metal coolant pumped through it. The

  12. Parallel optical sampler

    Energy Technology Data Exchange (ETDEWEB)

    Tauke-Pedretti, Anna; Skogen, Erik J; Vawter, Gregory A

    2014-05-20

    An optical sampler includes a first and second 1.times.n optical beam splitters splitting an input optical sampling signal and an optical analog input signal into n parallel channels, respectively, a plurality of optical delay elements providing n parallel delayed input optical sampling signals, n photodiodes converting the n parallel optical analog input signals into n respective electrical output signals, and n optical modulators modulating the input optical sampling signal or the optical analog input signal by the respective electrical output signals, and providing n successive optical samples of the optical analog input signal. A plurality of output photodiodes and eADCs convert the n successive optical samples to n successive digital samples. The optical modulator may be a photodiode interconnected Mach-Zehnder Modulator. A method of sampling the optical analog input signal is disclosed.

  13. Optical imaging probes in oncology.

    Science.gov (United States)

    Martelli, Cristina; Lo Dico, Alessia; Diceglie, Cecilia; Lucignani, Giovanni; Ottobrini, Luisa

    2016-07-26

    Cancer is a complex disease, characterized by alteration of different physiological molecular processes and cellular features. Keeping this in mind, the possibility of early identification and detection of specific tumor biomarkers by non-invasive approaches could improve early diagnosis and patient management.Different molecular imaging procedures provide powerful tools for detection and non-invasive characterization of oncological lesions. Clinical studies are mainly based on the use of computed tomography, nuclear-based imaging techniques and magnetic resonance imaging. Preclinical imaging in small animal models entails the use of dedicated instruments, and beyond the already cited imaging techniques, it includes also optical imaging studies. Optical imaging strategies are based on the use of luminescent or fluorescent reporter genes or injectable fluorescent or luminescent probes that provide the possibility to study tumor features even by means of fluorescence and luminescence imaging. Currently, most of these probes are used only in animal models, but the possibility of applying some of them also in the clinics is under evaluation.The importance of tumor imaging, the ease of use of optical imaging instruments, the commercial availability of a wide range of probes as well as the continuous description of newly developed probes, demonstrate the significance of these applications. The aim of this review is providing a complete description of the possible optical imaging procedures available for the non-invasive assessment of tumor features in oncological murine models. In particular, the characteristics of both commercially available and newly developed probes will be outlined and discussed.

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

    Science.gov (United States)

    Ren, Y; Li, X; Xu, W

    2001-07-01

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

  15. Biochemical and physiological basis of medical near-infrared spectroscopy

    Science.gov (United States)

    Joebsis-vander Vliet, Frans F.; Joebsis, Paul

    1999-10-01

    Near infrared spectroscopy (NIRS) can monitor both the redox status of Cytochrome c oxidase located in the mitochondria within the cell and the oxygenation of the blood in the tissue being monitored. Since the enzyme catalyzes more than 90% of oxygen utilization, it is the sink for the oxygen while the hemoglobin in the capillaries is the oxygen source. In order to evaluate the oxidative metabolic status of a tissue the optical data obtained from both molecules are commonly interpreted in the basis of test tube experiments with purified preparations. We are concerned that the validity of this practice may not have been tested sufficiently and raise four basic questions that have not yet been answered. Citing some examples of in vitro versus in vivo differences we conclude that more effort should be expended on the in vivo testing of the range of the signals, their natural variability, and the physiological and pathological meaning of their deviations from norm.

  16. Hamilton optics: transformational theory of optics

    Science.gov (United States)

    Winston, Roland; Ge, Wenjun

    2013-09-01

    In 1824 William Rowan Hamilton presented a memoir to the Royal Irish Academy on Optics(Trans. R. Irish. Acacamy, XV, 1828), which was the foundation for transformational optics, classical mechanics, nonimaging optics and thermodynamical foundation of nonimaging optics,etc. It is useful for us even in 2013 to revisit the Hamilton resolution.

  17. Quantitative imaging of basic functions in renal (patho)physiology.

    Science.gov (United States)

    Kang, Jung Julie; Toma, Ildiko; Sipos, Arnold; McCulloch, Fiona; Peti-Peterdi, Janos

    2006-08-01

    Multiphoton fluorescence microscopy offers the advantages of deep optical sectioning of living tissue with minimal phototoxicity and high optical resolution. More importantly, dynamic processes and multiple functions of an intact organ can be visualized in real time using noninvasive methods, and quantified. These studies aimed to extend existing methods of multiphoton fluorescence imaging to directly observe and quantify basic physiological parameters of the kidney including glomerular filtration rate (GFR) and permeability, blood flow, urinary concentration/dilution, renin content and release, as well as more integrated and complex functions like the tubuloglomerular feedback (TGF)-mediated oscillations in glomerular filtration and tubular flow. Streptozotocin-induced diabetes significantly increased single-nephron GFR (SNGFR) from 32.4 +/- 0.4 to 59.5 +/- 2.5 nl/min and glomerular permeability to a 70-kDa fluorophore approximately eightfold. The loop diuretic furosemide 2-fold diluted and increased approximately 10-fold the volume of distal tubular fluid, while also causing the release of 20% of juxtaglomerular renin content. Significantly higher speeds of individual red blood cells were measured in intraglomerular capillaries (16.7 +/- 0.4 mm/s) compared with peritubular vessels (4.7 +/- 0.2 mm/s). Regular periods of glomerular contraction-relaxation were observed, resulting in oscillations of filtration and tubular flow rate. Oscillations in proximal and distal tubular flow showed similar cycle times ( approximately 45 s) to glomerular filtration, with a delay of approximately 5-10 and 25-30 s, respectively. These innovative technologies provide the most complex, immediate, and dynamic portrayal of renal function, clearly depicting the components and mechanisms involved in normal physiology and pathophysiology.

  18. Advances in renal (patho)physiology using multiphoton microscopy.

    Science.gov (United States)

    Sipos, A; Toma, I; Kang, J J; Rosivall, L; Peti-Peterdi, J

    2007-11-01

    Multiphoton excitation fluorescence microscopy is a state-of-the-art confocal imaging technique ideal for deep optical sectioning of living tissues. It is capable of performing ultrasensitive, quantitative imaging of organ functions in health and disease with high spatial and temporal resolution which other imaging modalities cannot achieve. For more than a decade, multiphoton microscopy has been successfully used with various in vitro and in vivo experimental approaches to study many functions of different organs, including the kidney. This study focuses on recent advances in our knowledge of renal (patho)physiological processes made possible by the use of this imaging technology. Visualization of cellular variables like cytosolic calcium, pH, cell-to-cell communication and signal propagation, interstitial fluid flow in the juxtaglomerular apparatus (JGA), real-time imaging of tubuloglomerular feedback (TGF), and renin release mechanisms are reviewed. A brief summary is provided of kidney functions that can be measured by in vivo quantitative multiphoton imaging including glomerular filtration and permeability, concentration, dilution, and activity of the intrarenal renin-angiotensin system using this minimally invasive approach. New visual data challenge a number of existing paradigms in renal (patho)physiology. Also, quantitative imaging of kidney function with multiphoton microscopy has tremendous potential to eventually provide novel non-invasive diagnostic and therapeutic tools for future applications in clinical nephrology.

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

    Science.gov (United States)

    Guyton, Arthur C.

    1998-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

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

    Science.gov (United States)

    Nettar, Kartik; Maas, Corey

    2011-12-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  4. Some Recent Advances in Plant Physiology

    Science.gov (United States)

    Stafford, G. A.

    1972-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  6. PHYSIOLOGICAL RESPONSES OF MEN DURING SLEEP DEPRIVATION,

    Science.gov (United States)

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

  7. Physiology of the fetal and transitional circulation.

    Science.gov (United States)

    Finnemore, Anna; Groves, Alan

    2015-08-01

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

  8. Reproductive physiology of the male camelid.

    Science.gov (United States)

    Bravo, P W; Johnson, L W

    1994-07-01

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

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

    Science.gov (United States)

    Guyton, Arthur C.

    1998-01-01

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

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  11. Physiological responses induced by pleasant stimuli.

    Science.gov (United States)

    Watanuki, Shigeki; Kim, Yeon-Kyu

    2005-01-01

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

  12. Physiological, Psychological, and Social Effects of Noise

    Science.gov (United States)

    Kryter, K. D.

    1984-01-01

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

  13. Physiological and Growth Characteristics of Shewanella Species

    Science.gov (United States)

    2016-05-01

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

  14. Phage Therapy: Eco-Physiological Pharmacology

    OpenAIRE

    Abedon, Stephen T.

    2014-01-01

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

  15. Computers in Some Branches of Applied Physiology .

    Directory of Open Access Journals (Sweden)

    S.S. Verma

    1994-04-01

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

  16. Coronary physiology assessment in the catheterization laboratory

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  17. Anatomy and physiology of the stomach.

    Science.gov (United States)

    Soybel, David I

    2005-10-01

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

  18. Cloud optics

    CERN Document Server

    Kokhanovsky, A

    2006-01-01

    Clouds affect the climate of the Earth, and they are an important factor in the weather. Therefore, their radiative properties must be understood in great detail. This book summarizes current knowledge on cloud optical properties, for example their ability to absorb, transmit, and reflect light, which depends on the clouds' geometrical and microphysical characteristics such as sizes of droplets and crystals, their shapes, and structures. In addition, problems related to the image transfer through clouds and cloud remote sensing are addressed in this book in great detail. This book can be an im

  19. Quantum Optics

    CERN Document Server

    Garrison, J C

    2008-01-01

    Quantum optics, i.e. the interaction of individual photons with matter, began with the discoveries of Planck and Einstein, but in recent years it has expanded beyond pure physics to become an important driving force for technological innovation. This book serves the broader readership growing out of this development by starting with an elementary description of the underlying physics and then building up a more advanced treatment. The reader is led from the quantum theory of thesimple harmonic oscillator to the application of entangled states to quantum information processing. An equally impor

  20. Optical devices

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, Julio C.; Falicoff, Waqidi; Minano, Juan C.; Benitez, Pablo; Dross, Oliver; Parkyn, Jr., William A.

    2010-07-13

    An optical manifold for efficiently combining a plurality of blue LED outputs to illuminate a phosphor for a single, substantially homogeneous output, in a small, cost-effective package. Embodiments are disclosed that use a single or multiple LEDs and a remote phosphor, and an intermediate wavelength-selective filter arranged so that backscattered photoluminescence is recycled to boost the luminance and flux of the output aperture. A further aperture mask is used to boost phosphor luminance with only modest loss of luminosity. Alternative non-recycling embodiments provide blue and yellow light in collimated beams, either separately or combined into white.

  1. EDITORIAL: Optical orientation Optical orientation

    Science.gov (United States)

    SAME ADDRESS *, Yuri; Landwehr, Gottfried

    2008-11-01

    priority of the discovery in the literature, which was partly caused by the existence of the Iron Curtain. I had already enjoyed contact with Boris in the 1980s when the two volumes of Landau Level Spectroscopy were being prepared [2]. He was one of the pioneers of magneto-optics in semiconductors. In the 1950s the band structure of germanium and silicon was investigated by magneto-optical methods, mainly in the United States. No excitonic effects were observed and the band structure parameters were determined without taking account of excitons. However, working with cuprous oxide, which is a direct semiconductor with a relative large energy gap, Zakharchenya and his co-worker Seysan showed that in order to obtain correct band structure parameters, it is necessary to take excitons into account [3]. About 1970 Boris started work on optical orientation. Early work by Hanle in Germany in the 1920s on the depolarization of luminescence in mercury vapour by a transverse magnetic field was not appreciated for a long time. Only in the late 1940s did Kastler and co-workers in Paris begin a systematic study of optical pumping, which led to the award of a Nobel prize. The ideas of optical pumping were first applied by Georges Lampel to solid state physics in 1968. He demonstrated optical orientation of free carriers in silicon. The detection method was nuclear magnetic resonance; optically oriented free electrons dynamically polarized the 29Si nuclei of the host lattice. The first optical detection of spin orientation was demonstrated by with the III-V semiconductor GaSb by Parsons. Due to the various interaction mechanisms of spins with their environment, the effects occurring in semiconductors are naturally more complex than those in atoms. Optical detection is now the preferred method to detect spin alignment in semiconductors. The orientation of spins in crystals pumped with circularly polarized light is deduced from the degree of circular polarization of the recombination

  2. Physiologically activated phase transition systems for improved ocular retention of ketorolac tromethamine

    OpenAIRE

    Sunil Thakor; Imran Vhora; Jagruti Desai; Sneha Thakkar; Hetal Thakkar

    2012-01-01

    In present investigation, novel physiologically activated phase transition systems for Ketorolac Tromethamine was developed. In-situ gelling systems: pH sensitive gel using carbopol 980 and HPMC K100LV, ion sensitive gel using gallan gum and temperature sensitive gel using Poloxamer 407 and Poloxamer 188 were developed. The drug content, content uniformity, pH, optical transmittance, rheological property, bioadhesive strength, in-vitro drug release, ocular irritation and stability study were ...

  3. Optical Backplane Interconnection

    Science.gov (United States)

    Hendricks, Herbert D.

    1991-01-01

    Optical backplane interconnection (OBIT), method of optically interconnecting many parallel outputs from data processor to many parallel inputs of other data processors by optically changing wavelength of output optical beam. Requires only one command: exact wavelength necessary to make connection between two desired processors. Many features, including smallness advantageous to incorporate OBIT into integrated optical device. Simplifies or eliminates wiring and speeds transfer of data over existing electrical or optical interconnections. Computer hookups and fiber-optical communication networks benefit from concept.

  4. Optical Instruments

    Science.gov (United States)

    1990-01-01

    Precision Lapping and Optical Co. has developed a wide variety of hollow retroreflector systems for applications involving the entire optical spectrum; they are, according to company literature, cheaper, more accurate, lighter and capable of greater size than solid prisms. Precision Lapping's major customers are aerospace and defense companies, government organizations, R&D and commercial instrument companies. For example, Precision Lapping supplies hollow retroreflectors for the laser fire control system of the Army's Abrams tank, and retroreflectors have been and are being used in a number of space tests relative to the Air Force's Strategic Defense Initiative research program. An example of a customer/user is Chesapeake Laser Systems, producer of the Laser Tracker System CMS-2000, which has applications in SDI research and industrial robotics. Another customer is MDA Scientific, Inc., manufacturer of a line of toxic gas detection systems used to monitor hazardous gases present in oil fields, refineries, offshore platforms, chemical plants, waste storage sites and other locations where gases are released into the environment.

  5. Simultaneous measurement of time-domain fNIRS and physiological signals during a cognitive task

    Science.gov (United States)

    Jelzow, A.; Tachtsidis, I.; Kirilina, E.; Niessing, M.; Brühl, R.; Wabnitz, H.; Heine, A.; Ittermann, B.; Macdonald, R.

    2011-07-01

    Functional near-infrared spectroscopy (fNIRS) is a commonly used technique to measure the cerebral vascular response related to brain activation. It is known that systemic physiological processes, either independent or correlated with the stimulation task, can influence the optical signal making its interpretation challenging. The aim of the present work is to investigate the impact of task-evoked changes in the systemic physiology on fNIRS measurements for a cognitive paradigm. For this purpose we carried out simultaneous measurements of time-domain fNIRS on the forehead and systemic physiological signals, i.e. mean blood pressure, heart rate, respiration, galvanic skin response, scalp blood flow (flux) and red blood cell (RBC) concentration changes. We performed measurements on 15 healthy volunteers during a semantic continuous performance task (CPT). The optical data was analyzed in terms of depth-selective moments of distributions of times of flight of photons through the tissue. In addition, cerebral activation was localized by a subsequent fMRI experiment on the same subject population using the same task. We observed strong non-cerebral task-evoked changes in concentration changes of oxygenated hemoglobin in the forehead. We investigated the temporal behavior and mutual correlations between hemoglobin changes and the systemic processes. Mean blood pressure (BP), galvanic skin response (GSR) and heart rate exhibited significant changes during the activation period, whereby BP and GSR showed the highest correlation with optical measurements.

  6. Genetic and physiologic dissection of the vertebrate cardiac conduction system.

    Directory of Open Access Journals (Sweden)

    Neil C Chi

    2008-05-01

    Full Text Available Vertebrate hearts depend on highly specialized cardiomyocytes that form the cardiac conduction system (CCS to coordinate chamber contraction and drive blood efficiently and unidirectionally throughout the organism. Defects in this specialized wiring system can lead to syncope and sudden cardiac death. Thus, a greater understanding of cardiac conduction development may help to prevent these devastating clinical outcomes. Utilizing a cardiac-specific fluorescent calcium indicator zebrafish transgenic line, Tg(cmlc2:gCaMP(s878, that allows for in vivo optical mapping analysis in intact animals, we identified and analyzed four distinct stages of cardiac conduction development that correspond to cellular and anatomical changes of the developing heart. Additionally, we observed that epigenetic factors, such as hemodynamic flow and contraction, regulate the fast conduction network of this specialized electrical system. To identify novel regulators of the CCS, we designed and performed a new, physiology-based, forward genetic screen and identified for the first time, to our knowledge, 17 conduction-specific mutations. Positional cloning of hobgoblin(s634 revealed that tcf2, a homeobox transcription factor gene involved in mature onset diabetes of the young and familial glomerulocystic kidney disease, also regulates conduction between the atrium and the ventricle. The combination of the Tg(cmlc2:gCaMP(s878 line/in vivo optical mapping technique and characterization of cardiac conduction mutants provides a novel multidisciplinary approach to further understand the molecular determinants of the vertebrate CCS.

  7. A Brief History of Bacterial Growth Physiology

    Directory of Open Access Journals (Sweden)

    Moselio eSchaechter

    2015-04-01

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

  8. A brief history of bacterial growth physiology.

    Science.gov (United States)

    Schaechter, Moselio

    2015-01-01

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

  9. Advances in nonlinear optics

    CERN Document Server

    Chen, Xianfeng; Zeng, Heping; Guo, Qi; She, Weilong

    2015-01-01

    This book presents an overview of the state of the art of nonlinear optics from weak light nonlinear optics, ultrafast nonlinear optics to electro-optical theory and applications. Topics range from the fundamental studies of the interaction between matter and radiation to the development of devices, components, and systems of tremendous commercial interest for widespread applications in optical telecommunications, medicine, and biotechnology.

  10. Congenital optic tract hypoplasia.

    Science.gov (United States)

    Hatsukawa, Yoshikazu; Fujio, Takahiro; Nishikawa, Masanori; Taylor, David

    2015-08-01

    We report a case of isolated unilateral optic tract hypoplasia, described only twice previously. Bilateral optic disk hypoplasia was seen ophthalmoscopically and visual field studies showed an incongruous right homonymous hemianopia. Magnetic resonance imaging showed bilateral hypoplasia of both optic nerves and the left optic tract. Spectral domain optical coherence tomography mapping correlated well with the visual field studies.

  11. In Vivo Diffuse Optical Tomography and Fluorescence Molecular Tomography

    Directory of Open Access Journals (Sweden)

    Mingze Li

    2010-01-01

    Full Text Available Diffuse optical tomography (DOT and fluorescence molecular tomography (FMT are two attractive imaging techniques for in vivo physiological and psychological research. They have distinct advantages such as non-invasiveness, non-ionizing radiation, high sensitivity and longitudinal monitoring. This paper reviews the key components of DOT and FMT. Light propagation model, mathematical reconstruction algorithm, imaging instrumentation and medical applications are included. Future challenges and perspective on optical tomography are discussed.

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

    Data.gov (United States)

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

  13. Optical manifold

    Science.gov (United States)

    Falicoff, Waqidi; Chaves, Julio C.; Minano, Juan Carlos; Benitez, Pablo; Dross, Oliver; Parkyn, Jr., William A.

    2010-02-23

    Optical systems are described that have at least one source of a beam of blue light with divergence under 15.degree.. A phosphor emits yellow light when excited by the blue light. A collimator is disposed with the phosphor and forms a yellow beam with divergence under 15.degree.. A dichroic filter is positioned to transmit the beam of blue light to the phosphor and to reflect the beam of yellow light to an exit aperture. In different embodiments, the beams of blue and yellow light are incident upon said filter with central angles of 15.degree., 22.degree., and 45.degree.. The filter may reflect all of one polarization and part of the other polarization, and a polarization rotating retroreflector may then be provided to return the unreflected light to the filter.

  14. Physiological responses to daily light exposure

    Science.gov (United States)

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

    2016-04-01

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

  15. Epigenetics and transgenerational transfer: a physiological perspective.

    Science.gov (United States)

    Ho, D H; Burggren, W W

    2010-01-01

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

  16. Comparison of optic area measurement using fundus photography and optical coherence tomography between optic nerve head drusen and control subjects.

    Science.gov (United States)

    Flores-Rodríguez, Patricia; Gili, Pablo; Martín-Ríos, María Dolores; Grifol-Clar, Eulalia

    2013-03-01

    To compare optic disc area measurement between optic nerve head drusen (ONHD) and control subjects using fundus photography, time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT). We also made a comparison between each of the three techniques. We performed our study on 66 eyes (66 patients) with ONHD and 70 healthy control subjects (70 controls) with colour ocular fundus photography at 20º (Zeiss FF 450 IR plus), TD-OCT (Stratus OCT) with the Fast Optic Disc protocol and SD-OCT (Cirrus OCT) with the Optic Disc Cube 200 × 200 protocol for measurement of the optic disc area. The measurements were made by two observers and in each measurement a correction of the image magnification factor was performed. Measurement comparison using the Student's t-test/Mann-Whitney U test, the intraclass correlation coefficient, Pearson/Spearman rank correlation coefficient and the Bland-Altman plot was performed in the statistical analysis. Mean and standard deviation (SD) of the optic disc area in ONHD and in controls was 2.38 (0.54) mm(2) and 2.54 (0.42) mm(2), respectively with fundus photography; 2.01 (0.56) mm(2) and 1.66 (0.37) mm(2), respectively with TD-OCT, and 2.03 (0.49) mm(2) and 1.75 (0.38) mm(2), respectively with SD-OCT. In ONHD and controls, repeatability of optic disc area measurement was excellent with fundus photography and optical coherence tomography (TD-OCT and SD-OCT), but with a low degree of agreement between both techniques. Optic disc area measurement is smaller in ONHD compared to healthy subjects with fundus photography, unlike time-domain and spectral-domain optical coherence tomography in which the reverse is true. Both techniques offer good repeatability, but a low degree of correlation and agreement, which means that optic disc area measurement is not interchangeable or comparable between techniques. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  17. Fiber optics engineering

    CERN Document Server

    Azadeh, Mohammad

    2009-01-01

    Covering fiber optics from an engineering perspective, this text emphasizes data conversion between electrical and optical domains. Techniques to improve the fidelity of this conversion (from electrical to optical domain, and vice versa) are also covered.

  18. Coding for optical channels

    CERN Document Server

    Djordjevic, Ivan; Vasic, Bane

    2010-01-01

    This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.

  19. Quantum optics for experimentalists

    CERN Document Server

    Ou, Zhe-Yu Jeff

    2017-01-01

    This book on quantum optics is from the point of view of an experimentalist. It approaches the theory of quantum optics with the language of optical modes of classical wave theory, with which experimentalists are most familiar.

  20. Cell volume regulation: physiology and pathophysiology

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  1. Financial Anxiety, Physiological Arousal, and Planning Intention

    Directory of Open Access Journals (Sweden)

    John Grable

    2014-12-01

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

  2. From growth physiology to systems biology.

    Science.gov (United States)

    Schaechter, Moselio

    2006-09-01

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

  3. Physiological assessment of long pepper seeds

    Directory of Open Access Journals (Sweden)

    Francisco Pacheco Júnior

    2015-12-01

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

  4. New concept of physiologic anchorage control

    Directory of Open Access Journals (Sweden)

    Tian-Min Xu

    2015-01-01

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

  5. Improving the physiological realism of experimental models.

    Science.gov (United States)

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

    2016-04-06

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

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

    Science.gov (United States)

    2006-04-01

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

  7. Physiologic basis for understanding quantitative dehydration assessment.

    Science.gov (United States)

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

    2013-03-01

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

  8. Applied optics and optical design, part two

    CERN Document Server

    Conrady, A E

    2014-01-01

    Classic detailed treatment for practical designer. Fundamental concepts, systematic study and design of all types of optical systems. Reader can then design simpler optical systems without aid. Part Two of Two.

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

    Science.gov (United States)

    Damas, J

    2001-07-01

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

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

    Science.gov (United States)

    Rall, Jack A.

    2016-01-01

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

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

    Science.gov (United States)

    Navas, Carlos A

    2002-11-01

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

  12. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

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

    Science.gov (United States)

    Lazorthes, G

    1989-06-01

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

  14. Signal Processing of Random Physiological Signals

    CERN Document Server

    Lessard, Charles

    2006-01-01

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

  15. Physiological Disorders in Closed, Controlled Environment Crops

    Science.gov (United States)

    Wheeler, Raymond M.; Morrow, Robert C.

    2010-01-01

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

  16. Cardiovascular physiology and diseases of amphibians.

    Science.gov (United States)

    Heinz-Taheny, Kathleen M

    2009-01-01

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

  17. Concepts of Human Physiology in Ayurveda

    OpenAIRE

    Patwardhan, Dr. Kishor

    2008-01-01

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

  18. Intelligent Optics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Intelligent Optics Laboratory supports sophisticated investigations on adaptive and nonlinear optics; advancedimaging and image processing; ground-to-ground and...

  19. Fibre-optic communications

    CERN Document Server

    Lecoy, Pierre

    2010-01-01

    This book describes in a comprehensive manner the components and systems of fiber optic communications and networks. The first section explains the theory of multimode and single-mode fibers, then the technological features, including manufacturing, cabling, and connecting. The second section describes the various components (passive and active optical components, integrated optics, opto-electronic transmitters and receivers, and optical amplifiers) used in fiber optic systems. Finally, the optical transmission system design is explained, and applications to optical networks and fiber optic se

  20. Optical Remote Sensing Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optical Remote Sensing Laboratory deploys rugged, cutting-edge electro-optical instrumentation for the collection of various event signatures, with expertise in...

  1. Investigation of Optical Fibers for Nonlinear Optics.

    Science.gov (United States)

    1984-04-17

    Northwestern University, 1970. Experience Dr. Harrington has 13 years of research experi- ence in the area of optical properties of solids . Since joining...dynamics, and optical properties of solids . 34 34I ANTONIO C. PASTOR, Member of the Technical Staff, Optical Physics Department, Hughes Research

  2. Nanoscale optical interferometry with incoherent light

    Science.gov (United States)

    Li, Dongfang; Feng, Jing; Pacifici, Domenico

    2016-01-01

    Optical interferometry has empowered an impressive variety of biosensing and medical imaging techniques. A widely held assumption is that devices based on optical interferometry require coherent light to generate a precise optical signature in response to an analyte. Here we disprove that assumption. By directly embedding light emitters into subwavelength cavities of plasmonic interferometers, we demonstrate coherent generation of surface plasmons even when light with extremely low degrees of spatial and temporal coherence is employed. This surprising finding enables novel sensor designs with cheaper and smaller light sources, and consequently increases accessibility to a variety of analytes, such as biomarkers in physiological fluids, or even airborne nanoparticles. Furthermore, these nanosensors can now be arranged along open detection surfaces, and in dense arrays, accelerating the rate of parallel target screening used in drug discovery, among other high volume and high sensitivity applications. PMID:26880171

  3. Illusion optics

    Science.gov (United States)

    Lai, Yun; Ng, Jack; Chen, Huan-Yang; Zhang, Zhao-Qing; Chan, C. T.

    2010-09-01

    The technique of “transformation optics” establishes a correspondence between coordinate transformation and material constitutive parameters. Most of the transformation optics mappings give metamaterials that have graded positive refractive indices that can steer light in curves defined by the coordinate transformation. We will focus on those “folded-geometry mappings” that give negative refractive index materials that have special wave scattering properties. One interesting example is a kind of remote illusion device that can transform the stereoscopic image of an object into the illusion of some other object of our choice. The conceptual device can create the illusion without touching or encircling the object. For any incident wave, the device transforms the scattered waves of the original object into that of the object chosen for illusion outside a virtual boundary. We will illustrate some possible applications of this type of metamaterial remote device, including “cloaking at a distance,” partial cloaking, cloaking from an embedded device, revealing a hidden object inside a container, turning the image of one object into that of another object, and seeing through a wall. The feasibility of building this remote illusion device by metamaterials will also be discussed.

  4. Combining calcium imaging with other optical techniques.

    Science.gov (United States)

    Canepari, Marco; Zecevic, Dejan; Vogt, Kaspar E; Ogden, David; De Waard, Michel

    2013-12-01

    Ca(2+) imaging is a commonly used approach for measuring Ca(2+) signals at high spatial resolution. The method is often combined with electrode recordings to correlate electrical and chemical signals or to investigate Ca(2+) signals following an electrical stimulation. To obtain information on electrical activity at the same spatial resolution, Ca(2+) imaging must be combined with membrane potential imaging. Similarly, stimulation of subcellular compartments requires photostimulation. Thus, combining Ca(2+) imaging with an additional optical technique facilitates the study of a number of physiological questions. The aim of this article is to introduce some basic principles regarding the combination of Ca(2+) imaging with other optical techniques. We discuss the design of the optics, the design of experimental protocols, the optical characteristics of Ca(2+) indicators used in combination with an optical probe, and the affinity of the Ca(2+) indicator in relation to the type of measurement. This information will enable the reader to devise an optimal strategy for combined optical experiments.

  5. Light Optics for Optical Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Andorf, Matthew [NICADD, DeKalb; Lebedev, Valeri [Fermilab; Piot, Philippe [NICADD, DeKalb; Ruan, Jinhao [Fermilab

    2016-06-01

    In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.

  6. Task Differences, Stylistic Characteristics and Physiological Arousal.

    Science.gov (United States)

    1983-08-01

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

  7. The Physiology of Fear and Sound

    DEFF Research Database (Denmark)

    Garner, Tom Alexander; Grimshaw, Mark

    2013-01-01

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

  8. Physiologic and pharmacokinetic changes in pregnancy.

    Science.gov (United States)

    Costantine, Maged M

    2014-01-01

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

  9. The concept of function in modern physiology.

    Science.gov (United States)

    Roux, Etienne

    2014-06-01

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

  10. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY:

    Science.gov (United States)

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

  11. Anatomy and physiology of genital organs - women.

    Science.gov (United States)

    Graziottin, Alessandra; Gambini, Dania

    2015-01-01

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

  12. Physiologic and Pharmacokinetic Changes in Pregnancy

    Directory of Open Access Journals (Sweden)

    Maged eCostantine

    2014-04-01

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

  13. Electromyography physiology engineering and noninvasive applications

    CERN Document Server

    Parker, Philip; John Wiley & Sons

    2004-01-01

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

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

    Science.gov (United States)

    Khaitov, R M; Alekseev, L P

    2012-09-01

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

  15. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

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

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

  16. Physiological Disorders of Pear Shoot Cultures

    Science.gov (United States)

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

  17. Physiological considerations in radionuclide urodynamic studies

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-01-01

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

  18. FISH PHYSIOLOGY, TOXICOLOGY, AND WATER QUALITY

    Science.gov (United States)

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

  19. Supporting Placement Supervision in Clinical Exercise Physiology

    Science.gov (United States)

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

    2015-01-01

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

  20. Preparing Prospective Physical Educators in Exercise Physiology.

    Science.gov (United States)

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

    2000-01-01

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

  1. Myths and Truths from Exercise Physiology

    Science.gov (United States)

    Kieffer, H. Scott

    2008-01-01

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

  2. Challenges in Exercise Physiology Research and Education

    Science.gov (United States)

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

    2008-01-01

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

  3. Teaching Physics in a Physiologically Meaningful Manner

    Science.gov (United States)

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

    2010-01-01

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

  4. Experienced and physiological fatigue in neuromuscular disorders.

    NARCIS (Netherlands)

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

    2007-01-01

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

  5. Mechanisms of physiological and epileptic HFO generation

    NARCIS (Netherlands)

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

    2012-01-01

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

  6. Improving the physiological realism of experimental models

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    NARCIS (Netherlands)

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

    2000-01-01

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

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

    Science.gov (United States)

    Cheuvront, Samuel N; Kenefick, Robert W

    2014-01-01

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

  9. The concept of function in modern physiology

    Science.gov (United States)

    Roux, Etienne

    2014-01-01

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

  10. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

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

    2008-01-01

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

  11. Physiology and molecular biology of petal senescence

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    Science.gov (United States)

    Yeo, In-Sok

    2009-12-01

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

  13. Anatomy and Physiology. Revised Teacher Edition.

    Science.gov (United States)

    Hartman, Danene; And Others

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

  14. Physiological functions of MTA family of proteins.

    Science.gov (United States)

    Sen, Nirmalya; Gui, Bin; Kumar, Rakesh

    2014-12-01

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

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

    Science.gov (United States)

    Kutschera, Ulrich; Niklas, Karl J.

    2009-11-01

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

  16. Physiological Sociology. Endocrine Correlates of Status Behaviors,

    Science.gov (United States)

    1975-01-01

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

  17. From Dietary Fiber to Host Physiology

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  18. Physiological basis for residual feed intake

    National Research Council Canada - National Science Library

    Herd, R. M; Arthur, P. F

    2009-01-01

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

  19. Physiology of Exercise in the Cold

    Science.gov (United States)

    1991-01-01

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

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

    Science.gov (United States)

    Mendenhall, Alexander; Driscoll, Monica; Brent, Roger

    2016-02-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

    Borges, Sidnei; Mello-Carpes, Pâmela Billig

    2014-01-01

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

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

    Science.gov (United States)

    Borges, Sidnei; Mello-Carpes, Pâmela Billig

    2014-01-01

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

  4. Transformation optics and metamaterials

    Science.gov (United States)

    Chen, Huanyang; Chan, C. T.; Sheng, Ping

    2010-05-01

    Underpinned by the advent of metamaterials, transformation optics offers great versatility for controlling electromagnetic waves to create materials with specially designed properties. Here we review the potential of transformation optics to create functionalities in which the optical properties can be designed almost at will. This approach can be used to engineer various optical illusion effects, such as the invisibility cloak.

  5. Optical image encryption topology.

    Science.gov (United States)

    Yong-Liang, Xiao; Xin, Zhou; Qiong-Hua, Wang; Sheng, Yuan; Yao-Yao, Chen

    2009-10-15

    Optical image encryption topology is proposed based on the principle of random-phase encoding. Various encryption topological units, involving peer-to-peer, ring, star, and tree topologies, can be realized by an optical 6f system. These topological units can be interconnected to constitute an optical image encryption network. The encryption and decryption can be performed in both digital and optical methods.

  6. Introduction to ocean optics

    Science.gov (United States)

    Gordon, H. R.; Smith, R. C.; Zaneveld, J. R. V.

    1984-01-01

    In this introductory survey of optical oceanography, the fundamental inherent and apparent optical properties of natural waters are presented. Relationships between these inherent and apparent optical properties, as related through the radiative transfer equation, are then examined. Following the first three theoretical sections, brief discussions describing the application of ocean optics to geophysics, biological oceanography, and ocean remote sensing are then presented.

  7. A Multi-Scale Sampling Strategy for Detecting Physiologically Significant Signals in AVIRIS Imagery

    Science.gov (United States)

    Gamon, John A.; Lee, Lai-Fun; Qiu, Hong-Lie; Davis, Stephen; Roberts, Dar A.; Ustin, Susan L.

    1998-01-01

    Reflectance Index (PRI). Because the xanthophyll cycle pigments are photoregulatory pigments closely linked to photosynthetic function, this index can be used to derive relative photosynthetic rates. An additional signal with physiological significance is the 970 nm water absorption band, which provides a measure of liquid water content. This feature has been quantified both using a simple 2-band ratio (900/970 nm, here referred to as the "Water Band Index" or WBI;), and using the "continuum removal" method. Current atmospheric correction methods for AVIRIS imagery also obtain quantitative expressions of surface liquid water absorption based on the 970 nm water band and may be comparable to ground-based estimates of water content using this feature. However, physiological interpretations of both the PRI and the WBI are best understood at the leaf and canopy scales, where complications of atmospheric interference and complex stand and landscape features can be minimized, and where experimental manipulations can be readily applied. Currently it is not known whether these physiological indices can be used to derive meaningful physiological information from AVIRIS imagery. In addition to the problem of atmospheric interference, another challenge is that any simple physiological index can be confounded by multiple factors unrelated to physiology, and this problem can become more severe at progressively larger spatial scales. For example, previous work has suggested that both the PRI and the WBI, are strongly correlated with other optical measures of canopy structure (e.g., the Normalized Difference Vegetation Index or green vegetation fraction), indicating a confounding effect of structure on physiological signals at the larger, landscape scale. Furthermore, the normal operating mode of most imaging spectrometers does not allow simultaneous, ground truthing at a level of detail needed for physiological sampling. Additionally, manipulative experiments of physiology are difficult to

  8. Nonlinear Optical Rectennas

    CERN Document Server

    Stolz, A; Markey, L; Francs, G Colas des; Bouhelier, A

    2013-01-01

    We introduce strongly-coupled optical gap antennas to interface optical radiation with current-carrying electrons at the nanoscale. The transducer relies on the nonlinear optical and electrical properties of an optical antenna operating in the tunneling regime. We discuss the underlying physical mechanisms controlling the conversion and demonstrate that a two-wire optical antenna can provide advanced optoelectronic functionalities beyond tailoring the electromagnetic response of a single emitter. Interfacing an electronic command layer with a nanoscale optical device may thus be facilitated by the optical rectennas discussed here.

  9. Optics for dummies

    CERN Document Server

    Duree, Galen C

    2011-01-01

    The easy way to shed light on Optics In general terms, optics is the science of light. More specifically, optics is a branch of physics that describes the behavior and properties of light?including visible, infrared, and ultraviolet?and the interaction of light with matter. Optics For Dummies gives you an approachable introduction to optical science, methods, and applications. You'll get plain-English explanations of the nature of light and optical effects; reflection, refraction, and diffraction; color dispersion; optical devices, industrial, medical, and military applicatio

  10. [Hereditary optic neuropathies].

    Science.gov (United States)

    Milea, D; Verny, C

    2012-10-01

    Hereditary optic neuropathies are a group of heterogeneous conditions affecting both optic nerves, with an autosomal dominant, autosomal recessive, X-related or mitochondrial transmission. The two most common non-syndromic hereditary optic neuropathies (Leber's hereditary optic neuropathy and autosomal dominant optic atrophy) are very different in their clinical presentation and their genetic transmission, leading however to a common, non-specific optic nerve atrophy. Beyond the optic atrophy-related visual loss, which is the clinical hallmark of this group of diseases, other associated neurological signs are increasingly recognized.

  11. Principles of adaptive optics

    CERN Document Server

    Tyson, Robert

    2010-01-01

    History and BackgroundIntroductionHistoryPhysical OpticsTerms in Adaptive OpticsSources of AberrationsAtmospheric TurbulenceThermal BloomingNonatmospheric SourcesAdaptive Optics CompensationPhase ConjugationLimitations of Phase ConjugationArtificial Guide StarsLasers for Guide StarsCombining the LimitationsLinear AnalysisPartial Phase ConjugationAdaptive Optics SystemsAdaptive Optics Imaging SystemsBeam Propagation Syst

  12. Optical imaging and spectroscopy

    CERN Document Server

    Brady, David J

    2009-01-01

    An essential reference for optical sensor system design This is the first text to present an integrated view of the optical and mathematical analysis tools necessary to understand computational optical system design. It presents the foundations of computational optical sensor design with a focus entirely on digital imaging and spectroscopy. It systematically covers: Coded aperture and tomographic imaging Sampling and transformations in optical systems, including wavelets and generalized sampling techniques essential to digital system analysis Geometric, wave, and statis

  13. Full scattering profile of circular optical phantoms mimicking biological tissue

    Science.gov (United States)

    Feder, Idit; Wróbel, Maciej S.; Duadi, Hamootal; Fixler, Dror; Jedrzejewska-Szczerska, Malgorzata

    2017-02-01

    Human tissue is one of the most complex optical media since it is turbid and nonhomogeneous. In our poster, we suggest a new type of skin phantom and an optical method for sensing physiological tissue condition, basing on the collection of the ejected light at all exit angles, to receive the full scattering profile. Conducted experiments were carried out on an unique set-up for noninvasive encircled measurement. Set-up consisted of a laser, a photodetector and new tissues-like phantoms made with a polyvinyl chloride-plastisol (PVCP), silicone elastomer polydimethylsiloxane (PDMS) and PDMS with glycerol mixture. Our method reveals an isobaric point, which is independent of the optical properties. Furthermore, we present the angular distribution of cylindrical phantoms, in order to sense physiological tissue state.

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

    Science.gov (United States)

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

    2015-01-01

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

  15. Design of optical switches by illusion optics

    Science.gov (United States)

    Shoorian, H. R.; Abrishamian, M. S.

    2013-05-01

    In this paper, illusion optics theory is employed to form Bragg gratings in an optical waveguide in order to design an optical switch. By using an illusion device at a certain distance from the waveguide, the effective refractive index of the waveguide is remotely modulated, turning the waveguide into a distributed Bragg reflector (DBR) which blocks the waves at a stop band. By removing the illusion device, the waves propagate through the waveguide again. In addition, this method is used to remotely tune DBR optical properties such as resonant frequency and bandwidth in a wide range, which leads to a tunable filter for optical switching applications. Finally, using an illusion device at a distance, an optical cavity is created by inserting defects remotely in a DBR without any physical damage in the primary device.

  16. Distinguishing hyperhidrosis and normal physiological sweat production

    DEFF Research Database (Denmark)

    Thorlacius, Linnea; Gyldenløve, Mette; Zachariae, Claus

    2015-01-01

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

  17. Ventricular assist device in univentricular heart physiology.

    Science.gov (United States)

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

    2013-04-01

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

  18. Predictors of success in undergraduate human physiology.

    Science.gov (United States)

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

    1999-12-01

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

  19. Tissue physiology and the response to heat

    DEFF Research Database (Denmark)

    Horsman, Michael Robert

    2006-01-01

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

  20. A Physiologically Inspired Method for Audio Classification

    Directory of Open Access Journals (Sweden)

    David V. Anderson

    2005-06-01

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

  1. MEGen: A Physiologically Based Pharmacokinetic Model Generator

    Directory of Open Access Journals (Sweden)

    George D Loizou

    2011-11-01

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

  2. Hearables: Multimodal physiological in-ear sensing

    CERN Document Server

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

    2016-01-01

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

  3. Polydextrose: Physiological Function, and Effects on Health

    Directory of Open Access Journals (Sweden)

    Mariane Moreira Ramiro do Carmo

    2016-09-01

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

  4. Obesity: physiologic changes and challenges during laparoscopy.

    Science.gov (United States)

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

    2004-08-01

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

  5. Bioactive lipids in kidney physiology and pathophysiology

    Directory of Open Access Journals (Sweden)

    Daria Sałata

    2014-01-01

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

  6. Fostering improved anatomy and physiology instructor pedagogy.

    Science.gov (United States)

    Mattheis, Allison; Jensen, Murray

    2014-12-01

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

  7. Application of molecular biology in exercise physiology.

    Science.gov (United States)

    Booth, F W

    1989-01-01

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

  8. Model parameters for simulation of physiological lipids

    Science.gov (United States)

    McGlinchey, Nicholas

    2016-01-01

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

  9. Polydextrose: Physiological Function, and Effects on Health

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-09-08

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

  11. Tissue physiology and the response to heat

    DEFF Research Database (Denmark)

    Horsman, Michael Robert

    2006-01-01

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

  12. Didactic tools for understanding respiratory physiology

    Science.gov (United States)

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

    2007-11-01

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

  13. Didactic tools for understanding respiratory physiology

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-11-15

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

  14. Physiological phenotyping of plants for crop improvement.

    Science.gov (United States)

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

    2015-03-01

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

  15. Surface electromyography physiology, engineering and applications

    CERN Document Server

    Farina, Dario

    2016-01-01

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

  16. The physiological roles of primary phospholipase C.

    Science.gov (United States)

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

    2013-09-01

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

  17. Physiologic and pharmacokinetic changes in pregnancy

    OpenAIRE

    2014-01-01

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

  18. Physiology of yeasts in alcoholic fermentation processes

    OpenAIRE

    Guimarães, Pedro M. R.

    2008-01-01

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

  19. Anatomy and physiology of the upper airway.

    Science.gov (United States)

    Sahin-Yilmaz, Asli; Naclerio, Robert M

    2011-03-01

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

  20. Physiological roles of mitochondrial reactive oxygen species

    OpenAIRE

    Sena, Laura A.; Chandel, Navdeep S.

    2012-01-01

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

  1. Chromatin remodeling in cardiovascular development and physiology

    OpenAIRE

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

    2011-01-01

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

  2. Status of Research in Underwater Physiology

    Science.gov (United States)

    1956-03-01

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

  3. Language learning - physiological and psychological aspects

    Directory of Open Access Journals (Sweden)

    Dorina Tarnoveanu

    2010-06-01

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

  4. PHYSIOLOGIC TRANSFUSION TRIGGERS AND MASSIVE TRANSFUSION

    OpenAIRE

    Tánczos Krisztián; Molnár Zsolt

    2013-01-01

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

  5. Physiological Demands of Flat Horse Racing Jockeys.

    Science.gov (United States)

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

    2015-11-01

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

  6. Agreeableness, Extraversion, Stressor and Physiological Stress Response

    OpenAIRE

    Xiaoyuan Chu; Zhentao Ma; Yuan Li; Jing Han

    2015-01-01

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

  7. Physiologie de la reproduction = Physiology of reproduction

    OpenAIRE

    Legendre, Marc; JALABERT, B.

    1988-01-01

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

  8. Ecstasy from a physiological point of view

    OpenAIRE

    Kaj Björkqvist

    1982-01-01

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

  9. Physiological Acceptance Criteria for Cold Weather Clothing

    Science.gov (United States)

    1991-04-01

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

  10. Physiologically important metal nanoparticles and their toxicity.

    Science.gov (United States)

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

    2014-01-01

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

  11. Context-aware sensing of physiological signals.

    Science.gov (United States)

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

    2007-01-01

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

  12. Cardiovascular anatomy and physiology in the female.

    Science.gov (United States)

    Wingate, S

    1997-12-01

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

  13. Physiological roles of small RNA molecules.

    Science.gov (United States)

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

    2014-06-01

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

  14. Physical and physiological profiles of taekwondo athletes.

    Science.gov (United States)

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

    2014-06-01

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

  15. New concepts in white adipose tissue physiology

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-03-03

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

  16. Physiological investigation of dysarthria: recent advances.

    Science.gov (United States)

    Murdoch, Bruce E

    2011-02-01

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

  17. Ecological correlates of anuran exercise physiology.

    Science.gov (United States)

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

    1982-01-01

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

  18. Integrated circuits and electrode interfaces for noninvasive physiological monitoring.

    Science.gov (United States)

    Ha, Sohmyung; Kim, Chul; Chi, Yu M; Akinin, Abraham; Maier, Christoph; Ueno, Akinori; Cauwenberghs, Gert

    2014-05-01

    This paper presents an overview of the fundamentals and state of the-art in noninvasive physiological monitoring instrumentation with a focus on electrode and optrode interfaces to the body, and micropower-integrated circuit design for unobtrusive wearable applications. Since the electrode/optrode-body interface is a performance limiting factor in noninvasive monitoring systems, practical interface configurations are offered for biopotential acquisition, electrode-tissue impedance measurement, and optical biosignal sensing. A systematic approach to instrumentation amplifier (IA) design using CMOS transistors operating in weak inversion is shown to offer high energy and noise efficiency. Practical methodologies to obviate 1/f noise, counteract electrode offset drift, improve common-mode rejection ratio, and obtain subhertz high-pass cutoff are illustrated with a survey of the state-of-the-art IAs. Furthermore, fundamental principles and state-of-the-art technologies for electrode-tissue impedance measurement, photoplethysmography, functional near-infrared spectroscopy, and signal coding and quantization are reviewed, with additional guidelines for overall power management including wireless transmission. Examples are presented of practical dry-contact and noncontact cardiac, respiratory, muscle and brain monitoring systems, and their clinical applications.

  19. Environmental Nanoparticles Interactions with Plants: Morphological, Physiological, and Genotoxic Aspects

    Directory of Open Access Journals (Sweden)

    C. Remédios

    2012-01-01

    Full Text Available Nanoparticles (NPs are characterized by their small size (less than 100 nm and large surface area, which confer specific physicochemical properties as strength, electrical, and optical features. NPs can be derived from natural or anthropic sources, such as engineered or unwanted/incidental NPs. The composition, dimension, and morphology of engineered NPs enable their use in a variety of areas, such as electronic, biomedical, pharmaceutical, cosmetic, energy, environmental, catalysis, and materials science. As nanotechnology is an innovative and scientific growth area with an exponential production, more information is needed concerning the impacts of these nanomaterials (NMs in the environment and, particularly, in animals/humans health and in plants performance. So, research on NPs as emerging contaminants is therefore a new field in environmental health. This minireview describes, briefly, the NPs characterization and their occurrence in the environment stating air, water, and soil. Finally, particular emphasis is given to the interaction of NPs with plants at different levels: morphology, physiology, and genotoxicity. By analyzing this compiled information, it is evident that research on NPs phytotoxicity is in the beginning, and more comprehensive studies are needed not only on NPs cytotoxicity and genotoxicity but also on the best and the most reliable methods of assessing NPs toxicity.

  20. Nonlinear fiber optics

    CERN Document Server

    Agrawal, Govind P

    2001-01-01

    The Optical Society of America (OSA) and SPIE - The International Society for Optical Engineering have awarded Govind Agrawal with an honorable mention for the Joseph W. Goodman Book Writing Award for his work on Nonlinear Fiber Optics, 3rd edition.Nonlinear Fiber Optics, 3rd Edition, provides a comprehensive and up-to-date account of the nonlinear phenomena occurring inside optical fibers. It retains most of the material that appeared in the first edition, with the exception of Chapter 6, which is now devoted to the polarization effects relevant for light propagation in optical

  1. Introduction to nonimaging optics

    CERN Document Server

    Chaves, Julio

    2015-01-01

    Introduction to Nonimaging Optics covers the theoretical foundations and design methods of nonimaging optics, as well as key concepts from related fields. This fully updated, revised, and expanded Second Edition: Features a new and intuitive introduction with a basic description of the advantages of nonimaging opticsAdds new chapters on wavefronts for a prescribed output (irradiance or intensity), infinitesimal étendue optics (generalization of the aplanatic optics), and Köhler optics and color mixingIncorporates new material on the simultaneous multiple surface (SMS) design method in 3-D, int

  2. Organic nonlinear optical materials

    Science.gov (United States)

    Umegaki, S.

    1987-01-01

    Recently, it became clear that organic compounds with delocalized pi electrons show a great nonlinear optical response. Especially, secondary nonlinear optical constants of more than 2 digits were often seen in the molecular level compared to the existing inorganic crystals such as LiNbO3. The crystallization was continuously tried. Organic nonlinear optical crystals have a new future as materials for use in the applied physics such as photomodulation, optical frequency transformation, opto-bistabilization, and phase conjugation optics. Organic nonlinear optical materials, e.g., urea, O2NC6H4NH2, I, II, are reviewed with 50 references.

  3. Latching micro optical switch

    Science.gov (United States)

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

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

    Science.gov (United States)

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

    2016-12-01

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

  5. Active optical zoom system

    Science.gov (United States)

    Wick, David V.

    2005-12-20

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  6. Achromatic optical diode in fiber optics

    CERN Document Server

    Berent, Michal; Vitanov, Nikolay V

    2013-01-01

    We propose a broadband optical diode, which is composed of one achromatic reciprocal quarter-wave plate and one non-reciprocal quarter-wave plate, both placed between two crossed polarizers. The presented design of achromatic wave plates relies on an adiabatic evolution of the Stokes vector, thus, the scheme is robust and efficient. The possible simple implementation using fiber optics is suggested.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  8. Monitoring the Physiology of Animals in the Wild.

    Science.gov (United States)

    Arehart-Treichel, Joan

    1979-01-01

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

  9. Biomechanics and physiology in active manual wheelchair propulsion

    NARCIS (Netherlands)

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

    2001-01-01

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

  10. Towards ambulatory mental stress measurement from physiological parameters

    NARCIS (Netherlands)

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

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

  11. The importance of engineering physiological functionality into microbes

    NARCIS (Netherlands)

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

    2009-01-01

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

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

    African Journals Online (AJOL)

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

  13. Biomechanics and physiology in active manual wheelchair propulsion

    NARCIS (Netherlands)

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

    2001-01-01

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

  14. Towards ambulatory mental stress measurement from physiological parameters

    NARCIS (Netherlands)

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

    2013-01-01

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

  15. Acousto-optic laser optical feedback imaging

    CERN Document Server

    Jacquin, Olivier; Lacot, Eric; Hugon, Olivier; De Chatellus, Hugues Guillet; François, Ramaz

    2012-01-01

    We present a photon noise and diffraction limited imaging method combining the imaging laser and ultrasonic waves. The laser optical feedback imaging (LOFI) technique is an ultrasensitive imaging method for imaging objects through or embedded within a scattering medium. However, LOFI performances are dramatically limited by parasitic optical feedback occurring in the experimental setup. In this work, we have tagged the ballistic photons by an acousto-optic effect in order to filter the parasitic feedback effect and to reach the theoretical and ultimate sensitivity of the LOFI technique. We present the principle and the experimental setup of the acousto-optic laser optical feedback imaging (AO-LOFI) technique, and we demonstrate the suppression of the parasitic feedback.

  16. Optical Quantum Computing

    National Research Council Canada - National Science Library

    Jeremy L. O'Brien

    2007-01-01

    In 2001, all-optical quantum computing became feasible with the discovery that scalable quantum computing is possible using only single-photon sources, linear optical elements, and single-photon detectors...

  17. Fiber Optics Technology.

    Science.gov (United States)

    Burns, William E.

    1986-01-01

    Discusses various applications of fiber optics technology: information systems, industrial robots, medicine, television, transportation, and training. Types of jobs that will be available with fiber optics training (such as electricians and telephone cable installers and splicers) are examined. (CT)

  18. Fiber Optics Instrumentation Development

    Science.gov (United States)

    Chan, Patrick Hon Man; Parker, Allen R., Jr.; Richards, W. Lance

    2010-01-01

    This is a general presentation of fiber optics instrumentation development work being conducted at NASA Dryden for the past 10 years and recent achievements in the field of fiber optics strain sensors.

  19. Optical solenoid beams

    National Research Council Canada - National Science Library

    Lee, Sang-Hyuk; Roichman, Yohai; Grier, David G

    2010-01-01

    We introduce optical solenoid beams, diffractionless solutions of the Helmholtz equation whose diffraction-limited in-plane intensity peak spirals around the optical axis, and whose wavefronts carry...

  20. Plasmonic antennas and zero mode waveguides to enhance single molecule fluorescence detection and fluorescence correlation spectroscopy towards physiological concentrations

    CERN Document Server

    Punj, Deep; Moparthi, Satish Babu; de Torres, Juan; Grigoriev, Victor; Rigneault, Hervé; Wenger, Jérôme

    2014-01-01

    Single-molecule approaches to biology offer a powerful new vision to elucidate the mechanisms that underpin the functioning of living cells. However, conventional optical single molecule spectroscopy techniques such as F\\"orster fluorescence resonance energy transfer (FRET) or fluorescence correlation spectroscopy (FCS) are limited by diffraction to the nanomolar concentration range, far below the physiological micromolar concentration range where most biological reaction occur. To breach the diffraction limit, zero mode waveguides and plasmonic antennas exploit the surface plasmon resonances to confine and enhance light down to the nanometre scale. The ability of plasmonics to achieve extreme light concentration unlocks an enormous potential to enhance fluorescence detection, FRET and FCS. Single molecule spectroscopy techniques greatly benefit from zero mode waveguides and plasmonic antennas to enter a new dimension of molecular concentration reaching physiological conditions. The application of nano-optics...

  1. Investigating expectation effects using multiple physiological measures

    Directory of Open Access Journals (Sweden)

    Alexander eSiller

    2015-10-01

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

  2. Investigating expectation effects using multiple physiological measures.

    Science.gov (United States)

    Siller, Alexander; Ambach, Wolfgang; Vaitl, Dieter

    2015-01-01

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

  3. Elements of plant physiology in theophrastus' botany.

    Science.gov (United States)

    Pennazio, Sergio

    2014-01-01

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

  4. Evolution and physiology of neural oxygen sensing

    Directory of Open Access Journals (Sweden)

    Kauê Machado Costa

    2014-08-01

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

  5. Physiologic and Acoustic Effects of Opera Performance.

    Science.gov (United States)

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

    2017-01-01

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

  6. STUDY OF PHYSIOLOGICAL PROFILE OF INDIAN BOXERS

    Directory of Open Access Journals (Sweden)

    Gulshan Lal Khanna

    2006-07-01

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

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

    Science.gov (United States)

    Lange, K. A.

    1980-01-01

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

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

    Science.gov (United States)

    Claggett, Shalyn

    2011-01-01

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

  9. Statistical physics approaches to understanding physiological fluctuations

    Science.gov (United States)

    Hu, Kun

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

  10. [The ethical aspects of physiological experiment].

    Science.gov (United States)

    Al'bertin, S V

    2014-01-01

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

  11. Symbiotic physiology promotes homeostasis in Daisyworld.

    Science.gov (United States)

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

    2011-04-07

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

  12. Role of quercetin in vascular physiology.

    Science.gov (United States)

    Chirumbolo, Salvatore

    2012-12-01

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

  13. Bile acids in regulation of intestinal physiology.

    LENUS (Irish Health Repository)

    Keating, Niamh

    2009-10-01

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

  14. Rho kinases in cardiovascular physiology and pathophysiology.

    Science.gov (United States)

    Loirand, Gervaise; Guérin, Patrice; Pacaud, Pierre

    2006-02-17

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

  15. Modeling noisy time series Physiological tremor

    CERN Document Server

    Timmer, J

    1998-01-01

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

  16. Processing of physiological signals in automotive research.

    Science.gov (United States)

    Dambier, Michael; Altmüller, Tobias; Ladstätter, Ulrich

    2006-12-01

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

  17. The Cardiovascular Physiology of Sports and Exercise.

    Science.gov (United States)

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

    2015-07-01

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

  18. Space Physiology and Operational Space Medicine

    Science.gov (United States)

    Scheuring, Richard A.

    2009-01-01

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

  19. Conjoined twins: scientific cinema and Pavlovian physiology.

    Science.gov (United States)

    Krementsov, Nikolai

    2015-01-01

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

  20. A virtual laboratory system for physiology teaching

    Directory of Open Access Journals (Sweden)

    KArl Bohme

    1995-12-01

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

  1. Intracellular pH in sperm physiology.

    Science.gov (United States)

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

    2014-08-01

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

  2. Calcium signaling in physiology and pathophysiology

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  3. Basic Shock Physiology and Critical Care.

    Science.gov (United States)

    Roberts, Brian K

    2016-05-01

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

  4. Integrative physiology of orexins and orexin receptors.

    Science.gov (United States)

    Mieda, Michihiro; Sakurai, Takeshi

    2009-08-01

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

  5. Optical antennas and plasmonics

    OpenAIRE

    Park, Q-Han

    2009-01-01

    Optical antenna is a nanoscale miniaturization of radio or microwave antennas that is also governed by the rule of plasmonics. We introduce various types of optical antenna and make an overview of recent developments in optical antenna research. The role of local and surface plasmons in optical antenna is explained through antenna resonance and resonance conditions for specific metal structures are explicitly obtained. Strong electric field is shown to exist within a highly localized region o...

  6. Fibre-Optic Gyroscope

    Directory of Open Access Journals (Sweden)

    V. N. Saxena

    1983-04-01

    Full Text Available Comparative study of mechanical, ring-laser and fibre-optic gyroscopes has been made. The single mode fibre-optic gyroscope having a large number of turns of the optical fibre in the spool, replacing He-Ne gas laser by a GaAs laser diode, there by reducing the noise level, and using fully integrated fibre-optics, works out to be the best in the final analysis, for safe navigation and homing of the guided missiles.

  7. Giant optical manipulation.

    Science.gov (United States)

    Shvedov, Vladlen G; Rode, Andrei V; Izdebskaya, Yana V; Desyatnikov, Anton S; Krolikowski, Wieslaw; Kivshar, Yuri S

    2010-09-10

    We demonstrate a new principle of optical trapping and manipulation increasing more than 1000 times the manipulation distance by harnessing strong thermal forces while suppressing their stochastic nature with optical vortex beams. Our approach expands optical manipulation of particles into a gas media and provides a full control over trapped particles, including the optical transport and pinpoint positioning of ∼100  μm objects over a meter-scale distance with ±10  μm accuracy.

  8. Photonic crystal optical memory

    Science.gov (United States)

    Lima, A. Wirth; Sombra, A. S. B.

    2011-06-01

    After several decades pushing the technology and the development of the world, the electronics is giving space for technologies that use light. We propose and analyze an optical memory embedded in a nonlinear photonic crystal (PhC), whose system of writing and reading data is controlled by an external command signal. This optical memory is based on optical directional couplers connected to a shared optical ring. Such a device can work over the C-Band of ITU (International Telecommunication Union).

  9. Progress in optics

    CERN Document Server

    Wolf, Emil

    2009-01-01

    In the fourty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. The volumes in this series which have appeared up to now contain more than 300 review articles by distinguished research workers, which have become permanent records for many important developments.- Backscattering and Anderson localization of light- Advances in oliton manipulation in optical lattices- Fundamental quantum noise in optical amplification- Invisibility cloaks

  10. Emerging Correlation Optics

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Gbur, Gregory J.; Polyanskii, Peter;

    2012-01-01

    This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques.......This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques....

  11. Ternary optical computer principle

    Institute of Scientific and Technical Information of China (English)

    金翊; 何华灿; 吕养天

    2003-01-01

    The fundamental principle and the characteristics of ternary optical computer, using horizontal polarized light, vertical polarized light and no-intensity to express information, are propounded in thispaper. The practicability to make key parts of the ternary optical computer from modern micro or integrated optical devices, opto-electronic and electro-photonic elements is discussed. The principle can be applied in three-state optical fiber communication via horizontal and vertical polarized light.

  12. Advanced digital optical communications

    CERN Document Server

    Binh, Le Nguyen

    2015-01-01

    This book provides a fundamental understanding of digital communication applications in optical communication technologies. Emphasizing operation principles versus mathematical analysis, the Second Edition includes new coverage of superchannel optical transmission systems, metropolitan and long-haul optical systems and networks, and Nyquist pulse shaping and high spectral efficiency of optical transmission systems, as well as new homework problems and examples. Featuring theoretical foundations as well as practical case studies, the text focuses on enhancements to digital technologies that are

  13. Measuring Dynamic Kidney Function in an Undergraduate Physiology Laboratory

    Science.gov (United States)

    Medler, Scott; Harrington, Frederick

    2013-01-01

    Most undergraduate physiology laboratories are very limited in how they treat renal physiology. It is common to find teaching laboratories equipped with the capability for high-resolution digital recordings of physiological functions (muscle twitches, ECG, action potentials, respiratory responses, etc.), but most urinary laboratories still rely on…

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

    Science.gov (United States)

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

    1989-01-01

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

  15. Adaptive optical zoom sensor.

    Energy Technology Data Exchange (ETDEWEB)

    Sweatt, William C.; Bagwell, Brett E.; Wick, David Victor

    2005-11-01

    In order to optically vary the magnification of an imaging system, continuous mechanical zoom lenses require multiple optical elements and use fine mechanical motion to precisely adjust the separations between individual or groups of lenses. By incorporating active elements into the optical design, we have designed and demonstrated imaging systems that are capable of variable optical magnification with no macroscopic moving parts. Changing the effective focal length and magnification of an imaging system can be accomplished by adeptly positioning two or more active optics in the optical design and appropriately adjusting the optical power of those elements. In this application, the active optics (e.g. liquid crystal spatial light modulators or deformable mirrors) serve as variable focal-length lenses. Unfortunately, the range over which currently available devices can operate (i.e. their dynamic range) is relatively small. Therefore, the key to this concept is to create large changes in the effective focal length of the system with very small changes in the focal lengths of individual elements by leveraging the optical power of conventional optical elements surrounding the active optics. By appropriately designing the optical system, these variable focal-length lenses can provide the flexibility necessary to change the overall system focal length, and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses.

  16. All-optical repeater.

    Science.gov (United States)

    Silberberg, Y

    1986-06-01

    An all-optical device containing saturable gain, saturable loss, and unsaturable loss is shown to transform weak, distorted optical pulses into uniform standard-shape pulses. The proposed device performs thresholding, amplification, and pulse shaping as required from an optical repeater. It is shown that such a device could be realized by existing semiconductor technology.

  17. Integrated Optical Sensors

    NARCIS (Netherlands)

    Lambeck, Paul; Hoekstra, Hugo

    2003-01-01

    The optical (tele-) communication is the main driving force for the worldwide R&D on integrated optical devices and microsystems. lO-sensors have to compete with many other sensor types both within the optical domain (fiber sensors) and outside that domain, where sensors based on measurand induced c

  18. Integrated Optical Sensors

    NARCIS (Netherlands)

    Lambeck, Paul V.; Hoekstra, Hugo

    2003-01-01

    The optical (tele-) communication is the main driving force for the worldwide R&D on integrated optical devices and microsystems. lO-sensors have to compete with many other sensor types both within the optical domain (fiber sensors) and outside that domain, where sensors based on measurand induced c

  19. Optical Disk Technology.

    Science.gov (United States)

    Abbott, George L.; And Others

    1987-01-01

    This special feature focuses on recent developments in optical disk technology. Nine articles discuss current trends, large scale image processing, data structures for optical disks, the use of computer simulators to create optical disks, videodisk use in training, interactive audio video systems, impacts on federal information policy, and…

  20. Progress in optics

    CERN Document Server

    Wolf, Emil

    2015-01-01

    The Progress in Optics series contains more than 300 review articles by distinguished research workers, which have become permanent records for many important developments, helping optical scientists and optical engineers stay abreast of their fields. Comprehensive, in-depth reviewsEdited by the leading authority in the field

  1. Integrated Optics Some Aspects

    Directory of Open Access Journals (Sweden)

    R. Hradaynath

    1990-01-01

    Full Text Available Status of some key individual integrated optics components, their application in the field of telecommunications, integrated optoelectronic circuits, fibre optics sensors, optical interconnects and logic devices are highlighted in this paper. Possibilities of opto-opto processors in the computers field are also outlined.

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

    Science.gov (United States)

    Grundy, David

    2015-07-01

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

  3. Physiological regulation of NEFA availability: lipolysis pathway.

    Science.gov (United States)

    Stich, V; Berlan, M

    2004-05-01

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

  4. Gut Melatonin in Vertebrates: Chronobiology and Physiology.

    Science.gov (United States)

    Mukherjee, Sourav; Maitra, Saumen Kumar

    2015-01-01

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

  5. The conservation physiology of seed dispersal.

    Science.gov (United States)

    Ruxton, Graeme D; Schaefer, H Martin

    2012-06-19

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

  6. Is physiological glucocorticoid replacement important in children?

    Science.gov (United States)

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

    2017-01-01

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

  7. Misophonia: physiological investigations and case descriptions

    Directory of Open Access Journals (Sweden)

    Miren eEdelstein

    2013-06-01

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

  8. Physiological and phytosanitary potential of rocket seeds

    Directory of Open Access Journals (Sweden)

    Jucilayne Fernandes Vieira

    2015-02-01

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

  9. Physiological and psychological assessment of sound

    Science.gov (United States)

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

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

  10. Biotin: biochemical, physiological and clinical aspects.

    Science.gov (United States)

    Said, Hamid M

    2012-01-01

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

  11. Auxin physiology of the tomato mutant diageotropica

    Science.gov (United States)

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

    1989-01-01

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

  12. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

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

  13. Physiological characteristics of international female soccer players.

    Science.gov (United States)

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

    2014-02-01

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

  14. Undergraduate students' misconceptions about respiratory physiology.

    Science.gov (United States)

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

    1999-12-01

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

  15. Structure and Physiological Actions of Ghrelin

    Directory of Open Access Journals (Sweden)

    Christine Delporte

    2013-01-01

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

  16. Metabolic methanol: molecular pathways and physiological roles.

    Science.gov (United States)

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

    2015-04-01

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

  17. Physiological functions of plant cell coverings.

    Science.gov (United States)

    Hoson, Takayuki

    2002-08-01

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

  18. Ecstasy from a physiological point of view

    Directory of Open Access Journals (Sweden)

    Kaj Björkqvist

    1982-01-01

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

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

    Science.gov (United States)

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

  20. The conservation physiology of seed dispersal

    Science.gov (United States)

    Ruxton, Graeme D.; Schaefer, H. Martin

    2012-01-01

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

  1. Gut Melatonin in Vertebrates: Chronobiology and Physiology

    Directory of Open Access Journals (Sweden)

    Dr. Saumen Kumar Maitra

    2015-07-01

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

  2. Amateur boxing: physical and physiological attributes.

    Science.gov (United States)

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

    2015-03-01

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

  3. Physiological Effects of Touching Coated Wood

    Directory of Open Access Journals (Sweden)

    Harumi Ikei

    2017-07-01

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

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

    Science.gov (United States)

    Subhan, M. M. F.

    2013-01-01

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

  5. Optics and optical instruments an introduction

    CERN Document Server

    Johnson, B K

    2011-01-01

    This book illustrates basic practical applications of optical principle. Working models of telescopes, microscopes, photographic lenses, and optical projection systems are diagrammed and explained in full, as are the basic experiments for determining accuracy, power, angular field of view, amount of aberration, and all other necessary facts about the instrument. Throughout the book, only elementary mathematics is used, for the benefit of the student and the beginner in the field of optics.The author, an assistant professor at the Imperial College of Science and Technology in London, shows ho

  6. Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

    Science.gov (United States)

    Lugnani, Franco; Macchioro, Matteo

    2017-01-01

    Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that interface. Conclusion

  7. Cryoelectrolysis—electrolytic processes in a frozen physiological saline medium

    Directory of Open Access Journals (Sweden)

    Franco Lugnani

    2017-01-01

    Full Text Available Background Cryoelectrolysis is a new minimally invasive tissue ablation surgical technique that combines the ablation techniques of electrolytic ablation with cryosurgery. The goal of this study is to examine the hypothesis that electrolysis can take place in a frozen aqueous saline solution. Method To examine the hypothesis we performed a cryoelectrolytic ablation protocol in which electrolysis and cryosurgery are delivered simultaneously in a tissue simulant made of physiological saline gel with a pH dye. We measured current flow, voltage and extents of freezing and pH dye staining. Results Using optical measurements and measurements of currents, we have shown that electrolysis can occur in frozen physiological saline, at high subzero freezing temperatures, above the eutectic temperature of the frozen salt solution. It was observed that electrolysis occurs when the tissue resides at high subzero temperatures during the freezing stage and essentially throughout the entire thawing stage. We also found that during thawing, the frozen lesion temperature raises rapidly to high subfreezing values and remains at those values throughout the thawing stage. Substantial electrolysis occurs during the thawing stage. Another interesting finding is that electro-osmotic flows affect the process of cryoelectrolysis at the anode and cathode, in different ways. Discussion The results showing that electrical current flow and electrolysis occur in frozen saline solutions imply a mechanism involving ionic movement in the fluid concentrated saline solution channels between ice crystals, at high subfreezing temperatures. Temperatures higher than the eutectic are required for the brine to be fluid. The particular pattern of temperature and electrical currents during the thawing stage of frozen tissue, can be explained by the large amounts of energy that must be removed at the outer edge of the frozen lesion because of the solid/liquid phase transformation on that

  8. Optical Flashes Preceding GRBs

    CERN Document Server

    Paczynski, B

    2001-01-01

    Only one optical flash associated with a gamma-ray burst has been detected so far by ROTSE. There are also upper limits obtained by several groups for several bursts. Recent model calculations indicate a possibility that optical flash may precede the GRB. Such flashes are undetectable in the currently popular observing mode, with optical instruments responding to GRB triggers. There is a need to develop all sky optical monitoring system capable of recognizing flashes in real time, and more powerful instruments that could respond robotically to optical triggers and carry out follow up observations.

  9. Optical modulator including grapene

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  10. Paraxial Ray Optics Cloaking

    CERN Document Server

    Choi, Joseph S

    2014-01-01

    Despite much interest and progress in optical spatial cloaking, a three-dimensional (3D), transmitting, continuously multidirectional cloak in the visible regime has not yet been demonstrated. Here we experimentally demonstrate such a cloak using ray optics, albeit with some edge effects. Our device requires no new materials, uses isotropic off-the-shelf optics, scales easily to cloak arbitrarily large objects, and is as broadband as the choice of optical material, all of which have been challenges for current cloaking schemes. In addition, we provide a concise formalism that quantifies and produces perfect optical cloaks in the small-angle (`paraxial') limit, and must be satisfied by any good cloaks.

  11. Progress in optics

    CERN Document Server

    Wolf, Emil

    1977-01-01

    In the thirty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. At the time of inception of this series, the first lasers were only just becoming operational, holography was in its infancy, subjects such as fiber optics, integrated optics and optoelectronics did not exist and quantum optics was the domain of only a few physicists. The term photonics had not yet been coined. Today these fields are flourishing and have become areas of specialisation for many science and engineering students and n

  12. Optic disc oedema

    DEFF Research Database (Denmark)

    Nielsen, Marianne Kromann; Hamann, Steffen

    2014-01-01

    Optic disc oedema describes the nonspecific, localized swelling of the optic nerve head regardless of aetiology. Therefore, differentiating among the various aetiologies depends on a thorough history and knowledge of the clinical characteristics of the underlying conditions. Papilloedema strictly...... refers to optic disc oedema as a consequence of elevated intracranial pressure. It is usually a bilateral condition and visual function is preserved until late. Optic disc oedema caused by an anterior optic neuropathy is usually unilateral and accompanied by the loss of visual function....

  13. Optics in aircraft engines

    Science.gov (United States)

    Vachon, James; Malhotra, Subhash

    The authors describe optical IR&D (independent research and development) programs designed to demonstrate and evaluate optical technologies for incorporation into next-generation military and commercial aircraft engines. Using a comprehensive demonstration program to validate this technology in an on-engine environment, problems encountered can be resolved early and risk can be minimized. In addition to specific activities related to the optics demonstration on the fighter engine, there are other optical programs underway, including a solenoid control system, a light off detection system, and an optical communication link. Research is also underway in simplifying opto-electronics and exploiting multiplexing to further reduce cost and weight.

  14. Magneto-optical metamaterial

    CERN Document Server

    Sadatgol, Mehdi; Forati, Ebrahim; Levy, Miguel; Guney, Durdu O

    2015-01-01

    We propose a new class of metamaterials called magneto-optical metamaterials that offer enhanced angle of rotation in polarization compared to bulk magneto-optical materials. In the proposed approach, the permittivity tensor of a magneto-optical material is tailored by embedded wire meshes behaving as artificial plasma. We have shown that the angle of rotation in the magneto-optical metamaterial can be enhanced up to 9 times compared to bulk magneto-optical material alone while the polarization extinction ratio remains below -20dB and insertion loss is less than 1.5dB.

  15. Small scale optics

    CERN Document Server

    Yupapin, Preecha

    2013-01-01

    The behavior of light in small scale optics or nano/micro optical devices has shown promising results, which can be used for basic and applied research, especially in nanoelectronics. Small Scale Optics presents the use of optical nonlinear behaviors for spins, antennae, and whispering gallery modes within micro/nano devices and circuits, which can be used in many applications. This book proposes a new design for a small scale optical device-a microring resonator device. Most chapters are based on the proposed device, which uses a configuration know as a PANDA ring resonator. Analytical and nu

  16. Progress in optics

    CERN Document Server

    Wolf, Emil

    2006-01-01

    In the thirty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. At the time of inception of this series, the first lasers were only just becoming operational, holography was in its infancy, subjects such as fiber optics, integrated optics and optoelectronics did not exist and quantum optics was the domain of only a few physicists. The term photonics had not yet been coined. Today these fields are flourishing and have become areas of specialisation for many science and engineering students and n

  17. [Aspheric optics: physical fundamentals].

    Science.gov (United States)

    Mrochen, M; Büeler, M

    2008-03-01

    Especially regarding intraocular lenses and refractive corneal surgery, one finds numerous concepts on how to improve the optical quality of the human eye through aspheric optics. Aspheric optics consists of optical surfaces in which at least one surface (for example, the corneal surface) deviates from the spherical shape. An aspheric (that is, not spherical) surface enables the correction of aberrations, especially the spherical aberration, by freely shaping the optical surface. The optical aberrations of the human eye can theoretically be minimized through the use of aspheric optics; however, the results are always affected by the optical properties of the cornea and the lens. Aspheric intraocular lenses allow a reduction of postoperative spherical aberrations of the patient's eye, but an optimal individualized conformation can result only when the shape of the cornea (asphericity) is considered. By the same token, the ideal corneal asphericity after refractive surgery for an individual eye cannot be defined without knowing the optical properties of the intraocular structure. Theoretical observations of aspheric optics in refractive surgery show that with aspheric approaches, a higher optical quality for the human eye can be attained. These theoretical advantages must, however, prove themselves in everyday clinical routine.

  18. Optical system design

    CERN Document Server

    Fischer, Robert F

    2008-01-01

    Honed for more than 20 years in an SPIE professional course taught by renowned optical systems designer Robert E. Fischer, Optical System Design, Second Edition brings you the latest cutting-edge design techniques and more than 400 detailed diagrams that clearly illustrate every major procedure in optical design. This thoroughly updated resource helps you work better and faster with computer-aided optical design techniques, diffractive optics, and the latest applications, including digital imaging, telecommunications, and machine vision. No need for complex, unnecessary mathematical derivations-instead, you get hundreds of examples that break the techniques down into understandable steps. For twenty-first century optical design without the mystery, the authoritative Optical Systems Design, Second Edition features: Computer-aided design use explained through sample problems Case studies of third-millennium applications in digital imaging, sensors, lasers, machine vision, and more New chapters on optomechanic...

  19. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch

    2005-01-01

    at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...... glaucoma patients is six times higher at a perfusion pressure of 30 mmHg, which corresponds to a level where the optic nerve is hypoxic in experimental animals, as compared to perfusion pressure levels above 50 mmHg where the optic nerve is normoxic. Medical intervention can affect optic nerve oxygen......-oxygenase inhibitor, indomethacin, which indicates that prostaglandin metabolism plays a role. Laboratory studies suggest that carbonic anhydrase inhibitors might be useful for medical treatment of optic nerve and retinal ischemia, potentially in diseases such as glaucoma and diabetic retinopathy. However, clinical...

  20. Nonlinear optical systems

    CERN Document Server

    Lugiato, Luigi; Brambilla, Massimo

    2015-01-01

    Guiding graduate students and researchers through the complex world of laser physics and nonlinear optics, this book provides an in-depth exploration of the dynamics of lasers and other relevant optical systems, under the umbrella of a unitary spatio-temporal vision. Adopting a balanced approach, the book covers traditional as well as special topics in laser physics, quantum electronics and nonlinear optics, treating them from the viewpoint of nonlinear dynamical systems. These include laser emission, frequency generation, solitons, optically bistable systems, pulsations and chaos and optical pattern formation. It also provides a coherent and up-to-date treatment of the hierarchy of nonlinear optical models and of the rich variety of phenomena they describe, helping readers to understand the limits of validity of each model and the connections among the phenomena. It is ideal for graduate students and researchers in nonlinear optics, quantum electronics, laser physics and photonics.