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Stress, hippocampal neurogenesis and cognition： functional correlations

Frontiers in Biology 2016年第3期11卷 182-192页

作者： paul j. Lucassen Charlotte A. Oomen Centre for Neuroscienee Swammerdam Institute for Life Sciences University of Amsterdam Science Park 904 1098 XH Amsterdam The Netherlands Department of Molecular and Cellular Neurobiology Center for Neurogenomics and Cognitive ResearchNeuroscience Campus Amsterdam VU University Amsterdam De Boelelaan 1085 1081 HV Amsterdam The Netherlands

The brain of many species including humans, harbors stem cells that continue to generate new neurons up into adulthood. This form of structural plasticity occurs in a limited number of brain regions, i.e. the subventricular zone and the hippocampal dentate gyrus and is regulated by environmental and hormonal factors. In this minireview, we provide an overview of the effects of stress and glucocorticoid hormones on adult hippocampal neurogenesis and discuss how these effects may be relevant for cognitive function and possibly, brain disease. While its exact functional role remains elusive, adult neurogenesis has been implicated in learning and memory, fear and mood regulation and recently, adult-born neurons were found to be involved in specific cognitive functions such as pattern separation （i.e. the ability to form unique memory representations） and cognitive flexibility. The process of adult neurogenesis is influenced by several factors; whereas e.g. exercise stimulates, exposure to stress and stress hormones generally inhibit neurogenesis. Effects of acute, mild stress are generally short-lasting and recover quickly, but chronic or severe forms of stress can induce lasting reductions in adult neurogenesis. Some of the inhibitory effects of stress can be rescued by exercise, by allowing a period of recovery from stress, by drugs that target the stress system, or by some, but not all, antidepressants. Stress may, partly through its effects on adult neurogenesis, alter structure and plasticity of the hippocampal circuit. This can lead to subsequent changes in stress responsivity and aspects of memory processing, which may be particularly relevant for stress related psychopathology or brain diseases that involve perturbed memory processing.

关键词： adult neurogenesis stem cells hippocampus stress memory pattern separation cognition

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Endoscopic Management of Pediatric Cholesteatoma

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j.urnal of Otology 2020年第1期15卷 17-26页

作者： Peter j.ryan Nirmal P.Patel Department of Otolaryngology and Head and Neck Surgery Royal North Shore HospitalSt LeonardsNSWAustralia Kolling Deafness Research Centre Macquarie University and University of SydneyNSWAustralia

Pediatric cholesteatoma occurs in one of two forms:congenital cholesteatoma,developing from embryonic epidermal cell rests or acquired cholesteatoma,associated with a focal defect in the tympanic *** disease has been traditionally managed with the operating microscope,often requiring mastoidectomy for adequate visualization of and access to the middle ear and mastoid ***,advances in endoscopic equipment have enabled otologists to manage most cases of pediatric cholesteatoma via a minimally-invasive,transcanal endoscopic *** review discusses the current literature relating to the etiopathogenesis,assessment and endoscopic management of pediatric *** outcomes of endoscopic treatment,emerging trends and technologies are also reviewed.

关键词： Cholesteatoma Pediatric Endoscopic Minimally-invasive Middle ear Mastoid

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How Do Sugars Regulate Plant Growth and Development？ New Insight into the Role of Treha Iose-6-Phosphate

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Molecular Plant 2013年第2期6卷 261-274页

作者： Liam E. O'Hara Matthew j. paul Astrid Wingler Genetics Evolution and Environment University College London Gower Street London WCl E 6BT UK Plant Science Rothamsted Research Harpenden Hertfordshire AL5 2JQ UK

Plant growth and development are tightly controlled in response to environmental conditions that influence the availability of photosynthetic carbon in the form of sucrose. Trehalose-6-phosphate （T6P）, the precursor of trehalose in the biosynthetic pathway, is an important signaling metabolite that is involved in the regulation of plant growth and development in response to carbon availability. In addition to the plant＇s own pathway for trehalose synthesis, formation of T6P or trehalose by pathogens can result in the reprogramming of plant metabolism and development. Developmental processes that are regulated by T6P range from embryo development to leaf senescence. Some of these processes are regulated in interaction with phytohormones, such as auxin. A key interacting factor of T6P signaling in response to the environment is the protein kinase sucrose non-fermenting related kinase-1 （SnRK1）, whose catalytic activity is inhibited by T6R SnRK1 is most likely involved in the adj.stment of metabolism and growth in response to starvation. The transcription factor bZlP11 has recently been identified as a new player in the T6P/SnRK1 regulatory pathway. By inhibiting SnRK1, T6P promotes biosynthetic reactions. This regulation has important consequences for crop production, for example, in the developing wheat grain and during the growth of potato tubers.

关键词： bZlP11 carbon availability plant development starvation sucrose non-fermenting related kinase-1 (SnRK1) trehalose trehalose-6-phosphate.

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Measurement of in-plane deformations of microsystems by digital holography and speckle interferometry(Invited Paper)

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Chinese Optics Letters 2009年第12期7卷 1109-1112页

作者： G. Pedrini j. Gaspar O. paul W. Osten Institut fr Technische Optik Universitt Stuttgart Department of Microsystems Engineering-IMTEK Universitt Freiburg

The reliability of microsystems is an important issue and for their quality inspection, it is necessary to know the displacements or deformations due to the applied mechanical, thermal, or electrostatic loads. We show how interferometrical techniques like digital holography and speckle interferometry can be used for the measurement of in plane deformations of microsystems with nanometric accuracy and we give a description of the measurement uncertainties.

关键词： Invited Paper Measurement of in-plane deformations of microsystems by digital holography and speckle interferometry

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Vibration induced flow in hoppers:DEM 2D polygon model

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Particuology 2008年第6期6卷 455-466页

作者： Feras Y. Fraige paul A. Langston Andrew j. Matchett j.hn Dodds Faculty of Mining and Environmental Engineering Al-Hussein Bin Talal University Jordan Chemical and Environmental Engineering Nottingham University University Park Chemical Engineering University of Teesside Centre RAPSODEE Ecole Des Mines

A two-dimensional discrete element model （DEM） simulation of cohesive polygonal particles has been developed to assess the benefit of point source vibration to induce flow in wedge-shaped hoppers. The particle-particle interaction model used is based on a multi-contact principle. The first part of the study investigated particle discharge under gravity without vibration to determine the critical orifice size （Bc） to j.st sustain flow as a function of particle shape. It is shown that polygonal-shaped particles need a larger orifice than circular particles. It is also shown that Bc decreases as the number of particle vertices increases. Addition of circular particles promotes flow of polygons in a linear manner. The second part of the study showed that vibration could enhance flow, effectively reducing Bc. The model demonstrated the importance of vibrator location （height）, consistent with previous continuum model results, and vibration amplitude in enhancing flow.

关键词： Bulk solids Vibration DEM Hoppers Materials handling Polygon

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Cardiac remodeling as a consequence of atrial fibrillation： An anatomical study of perfusion-fixed human heart specimens

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j.urnal of Geriatric Cardiology 2011年第3期8卷 141-146页

作者： Christopher D Rolfes Stephen A Howard ryan P Golf paul A Iaizzo Department of Biomedical Engineering University of Minnesota Minneapolis MAr 55455 USA Department of Surgery University of Minnesota Minneapolis MN55455 USA Department of Integrative Biology and Physiology University of Minnesota Minneapolis MN 55455 USA

Background Atrial fibrillation （AF） causes a continuum of atrial anatomical remodeling. Methods Using a library of perfusion-fixed human hearts, specimens with AF were compared to controls. During this preliminary assessment study, direct measurements were taken of atrial volume, pulmonary vein （PV） circumference, and left atrial （LA） wall thicknesses. Results Hearts with AF typically had larger atrial volumes, as well as a much larger variation in volume compared to controls （range of 59.6-227.1 mL in AF hearts compared to 65.1-115.9 mL in controls）. For all hearts, right PVs were larger than left PVs （mean： 171.4 ± 84.6 mm^2 for right and 1182 ± 50.1 mm^2 for left, P 〈 0.005）. LA wall thicknesses ranged from 0.7 mm to 3.1 mm for both AF and control hearts. Conclusions Hearts with AF had a large range of sizes which is consistent with the progression of atrial remodeling during AF. The large range of thicknesses will influence the amount of energy needed to create transmural lesions during ablation procedures.

关键词： left atrial dimensions volumes pulmonary vein ostia atrial fibrillation

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The role of latitudinal, genetic and temperature variation in the induction of diapause of Papilio glaucus （Lepidoptera： Papilionidae）

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Insect Science 2018年第2期25卷 328-336页

作者： Sean F. ryan Patti Valella Gabrielle Thivierge Matthew L. Aardema j. Mark Scriber Department of Biological Sciences University of Notre Dame Notre Dame Indiana USA USDA-ARS Center for Medical Agricultural and Veterinary Entomology 1600/1700 Southwest 23rd Drive Gainesville Florida USA Department of Entomology Michigan State University East Lansing Michigan USA Life Science Department Long Beach City College Long Beach California USA Sackler Institute for Comparative Genomics American Museum of Natural History New York New York USA McGuire Centerfor Lepidoptera and Diversity University of Florida Gainesville Florida US

A key adaptation in insects for dealing with variable environmental conditions is the ability to diapause. The tiger swallowtail butterflies, Papilio glaucus and P. canadensis are ideal species to explore the genetic causes and population genetic consequences of diapause because divergence in this trait is believed to be a salient factor in maintaining a hybrid zone between these species. Yet little is known about the factors that influence diapause induction in this system. Here we explored how spatial （latitudinal）, environmental （temperature） and genetic （hybridization） factors affect diapause induction in this system. Specifically, a series of growth chamber experiments using wild caught individuals from across the eastern United States were performed to：（1） evaluate how critical photoperiod varies with latitude, （2） isolate the stage in which induction occurs, （3） test whether changes in temperature affected rates of diapause induction, and （4） explore how the incidence of diapause is affected in hybrid offspring. We find that induction occurs in the larval stage, is not sensitive to a relatively broad range of temperatures, appears to have a complex genetic basis （i.e., is not simply a dominant trait following a Mendelian inheritance pattern） and that the critical photoperiod increases by 0.4 h with each increasing degree in latitude. This work deepens our understanding of how spatial, environmental and genetic variation influences a key seasonal adaptation （diapause induction） in a well-developed ecological model system and will make possible future studies that explore how climatic variation affects the population dynamics and genetics of this system.

关键词： adaptation critical photoperiod development diapauses facultative hybridization

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Robust Filtration Techniques in Geometrical Metrology and Their Comparison

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International j.urnal of Automation and computing 2013年第1期10卷 1-8页

作者： Shan Lou Wen-Han Zeng Xiang-Qian j.ang paul j. Scott EPSRC Centre for Innovative Manufacturing in Advanced Metrology University of Huddersfield

Filtration is one of the core elements of analysis tools in geometrical metrology. Filtration techniques are progressing along with the advancement of manufacturing technology. Modern filtration techniques are required to be robust against outliers, applicable to surfaces with complex geometry and reliable in whole range of measurement data. A comparison study is conducted to evaluate commonly used robust filtration techniques in the field of geometrical metrology, including the two-stage Gaussian filter, the robust Gaussian regression filter, the robust spline filter and morphological filters. They are compared in terms of four aspects： functionality, mathematical computation, capability and characterization parameters. As a result, this study offers metrologists a guideline to choose the appropriate filter for various applications.

关键词： Geometrical metrology robust Gaussian regression filter robust spline filter morphological filters surface roughness

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Scales of snow depth variability in high elevation rangeland sagebrush

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Frontiers of Earth Science 2017年第3期11卷 469-481页

作者： Molly E. TEDESCHE Steven R. FASSNACHT paul j. MEIMAN Watershed Science Department of Ecosystem Science and Sustainability Colorado State University Fort Collins CO 80523-1476 USA Intemational Arctic Research Center Water & Environmental Research Center Institute of Northern Engineering University of Alaska Fairbanks Fairbanks AK 99775 USA Cooperative Institute for Research in the Atmosphere Fort Collins CO 80523-1375 USA Natural Resources Ecology Laboratory Fort Collins CO 80523-1499 USA Abt. Kartographie GIS & Femerkundung Geographisches Institut Georg-August-Universitat Gottingen 37077 Gottingen Germany Rangeland Ecosystem Science Department of Forest and Rangeland Stewardship Colorado State University Fort Collins CO 80523 USA

In high elevation semi-arid rangelands, sage- brush and other shrubs can affect transport and deposition of wind-blown snow, enabling the formation of snowdrifts. Datasets from three field experiments were used to investigate the scales of spatial variability of snow depth around big mountain sagebrush （Artemisia tridentata Nutt.） at a high elevation plateau rangeland in North Park, Colorado, during the winters of 2002, 2003, and 2008. Data were collected at multiple resolutions （0.05 to 25 m） and extents （2 to 1000 m）. Finer scale data were collected specifically for this study to examine the correlation between snow depth; sagebrush microtopogra- phy, the ground surface, and the snow surface, as well as the temporal consistency of snow depth patterns. Vario- grams were used to identify the spatial structure and the Moran＇s I statistic was used to determine the spatial correlation. Results show some temporal consistency in snow depth at several scales. Plot scale snow depth variability is partly a function of the nature of individual shrubs, as there is some correlation between the spatial structure of snow depth and sagebrush, as well as between the ground and snow depth. The optimal sampling resolution appears to be 25-cm, but over a large area, this would require a multitude of samples, and thus a random stratified approach is recommended with a fine measurement resolution of 5-cm.

关键词： snow hydrology high elevation rangelands,spatial statistics variograms snow pack spatial variability,snow drifts

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Dominance network structure across reproductive contexts in the cooperatively breeding cichlid fish Neolamprologus pulcher

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Current Zoology 2015年第1期61卷 45-54页

作者： Cody j. DEY Q.Y. j.anne TAN Constance M. O'CONNOR Adam R. REDDON j. ryan CALDWELL Sigal BALSHINE Department of Biology McMaster University Hamilton Ontario ON L8S 4K1 Canada Department of Psychology Neuroscience and Behaviour McMaster University Hamilton Ontario L8S 4L8 Canada

While a large number of studies have described animal social networks, we have a poor understanding of how these networks vary with ecological and social conditions. For example, reproductive periods are an important life-history stage that may involve changes in dominance relationships among individuals, yet no study to date has compared social networks of do- minance interactions （i.e. dominance networks） across reproductive contexts. We first analyzed a long-term dataset on captive so- cial groups of the cooperatively breeding cichlid Neolamprologuspulcher, and found that eviction events were significantly more common around reproduction than expected by chance. Next, we compared the structure of dominance networks during early pa- rental care and non-reproductive periods, using one of the first applications of exponential random graph models in behavioral biology. Contrary to our predictions, we found that dominance networks showed few changes between early parental care and non-reproductive periods. We found no evidence that dominance interactions became more skewed towards larger individuals, became more frequent between similar-sized individuals, or became more biased towards a particular sex during parental care. However, we did find that there were relatively more dominance interactions between opposite-sex dyads in the early parental care period, which may be a by-product of increased sexual interactions during this time. This is the first study in behavioral ecology to compare social networks using exponential random graph modeling, and demonstrates a powerful analytical framework for future studies in the field [Current Zoology 61 （1）： 45-54, 2015].

关键词： Social network Aggression Submissive Hierarchy Parental care P* model

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