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Discharge-Stage Relationship on Urban Streams Evaluated at USGS Gauging Stations,***,Missouri

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Journal of Earth Science 2020年第6期31卷 1133-1141页

作者： Robert E.Criss david l.nelson Department of Earth and Planetary Sciences Washington UniversitySt.Louis MO 63130USA Columbia Cir Pasadena CA 91105USA

Extensive USGS data tables and detailed,1 m2 li DAR surveys are used to determine the optimal power n that relates discharge(Q)to stage(h*)above channel bottom(ho)at 39 gauging stations on small streams in the ***,Missouri area,all of which have catchments of 0.6 to 220 *** different methodologies are employed to determine both n and ho:(1)optimizing linearity in a plot of Q1/n *** stage(hl)using USGS field measurements at each site;(2)optimizing linearity in a plot of Q1/n *** using USGS rating tables at each site;(3)a mathematical inverse method applied to the same USGS rating tables;(4)use of li DAR data on channel geometry to determine the power dependences of channel area A and hydraulic radius H on h*,combined with the Manning and rational equations to predict *** these methods,only methods 2 and 3 compare favorably,and these values compare poorly with Method 1 based on field data,and with method 4 based on theoretical and empirical *** Method 4 is predictive,it provides a useful alternative to methods 1–3 that are based on USGS field measurements,which are heavily weighted toward low *** conclude that the apparent values of n in the USGS rating tables are systematically too low for small streams.

关键词： stream gauging li DAR topography urban flooding discharge hydrology

Generation and Propagation of an Urban Flash Flood and Our Collective Responsibilities

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Journal of Earth Science 2022年第6期33卷 1624-1628页

作者： Robert E.Criss Eric M.Stein david l.nelson Department of Earth and Planetary Sciences Washington UniversitySt.LouisMO 63130USA 7427 Chamberlain Ave. University CitySt.LouisMO 63130USA 470 Columbia Circle PasadenaCA 91105USA

0 INTRODUCTION Destructive flash flooding is a growing global problem,with dangers being particularly acute in densely populated urban areas. The intensity of rainfall events is increasing, creating high runoff rates ... 详细信息

关键词： Flash flash Generation

Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina Hromada Patrick Heimel Markus Kerbl lászlóGál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.Heinzel Antal Nógrádi Andreas H.Teuschl-Woller david Hercher Department life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of Hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

Fo screen or not to screen： the prostate cancer dilemma

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Asian Journal of Andrology 2015年第1期17卷 44-45页

作者： nelson N Stone E david Crawford Departments of Urology and Radiation Oncology The Icahn School of Medicine at Mount Sinai New York NY USA Department of Surgery Division of Urology and Radiation Oncology The Anschutz Cancer Center The University of Colorado Health Sciences Center. Aurora. CO. USA.

The European Randomized Study of Screening for Prostate （ERSPC） has updated their previous seminal report on prostate cancer mortality comparing screened men to controls. Now with 13 years follow-up, the rate ratio of prostate cancer mortality was 0.79 favoring the screened population. The authors concluded that there was a ＂substantial reduction in prostate cancer mortality attributable to testing with prostate-specific antigen （PSA）＂ but they also stated that a＂quantification of harms＂ needed to be addressed. The issue of harms was not addressed by the ERSPC （at least not in this report） and hence this additional statement most likely reflects the controversy currently surrounding the risks associated with over-diagnosis and treatment of indolent diseases inadvertently detected by a screening protocol, In addition, the positive results from this trial conflict with those of the prostate, lung, colorectal and ovarian （PlCO）2 study and reouire further elaboration.

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Complement-dependent neuroinflammation in spinal cord injury:from pathology to therapeutic implications

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Neural Regeneration Research 2025年第5期20卷 1324-1335页

作者： Hassan Saad Bachar El Baba Ali Tfaily Firas Kobeissy Juanmarco Gutierrez Gonzalez Daniel Refai Gerald R.Rodts Christian Mustroph david Gimbel Jonathan Grossberg Daniel l.Barrow Matthew F.Gary Ali M.Alawieh Department of Neurosurgery Emory University School of MedicineAtlantaGAUSA Department of Neurology Yale UniversityNew HavenCTUSA Center for Neurotrauma Multiomics&Biomarkers(CNMB)Morehouse School of MedicineAtlantaGAUSA

Spinal cord injury remains a major cause of disability in young adults,and beyond acute decompression and rehabilitation,there are no pharmacological treatments to limit the progression of injury and optimize recovery in this *** the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation,a similar role for complement in spinal neuroinflammation is a focus of ongoing *** this work,we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins,triggers of complement activation,and role of effector functions in the *** study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris,and or activation via antibody binding to damage-associated molecular *** effector functions of complement have been implicated in spinal cord injury,and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord *** this pathophysiological review,we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human *** review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury,to evaluate the phases of involvement of opsonins and anaphylatoxins,and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models.

关键词： complement neuroinflammation neuroplasticity regeneration spinal cord injury targeted therapy

TOPOlOGY AND CASCADING lINE OUTAGES IN POWER GRIDS

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Journal of Systems Science and Systems Engineering 2007年第2期16卷 202-221页

作者： david l. PEPYNE University of Massachusetts Amherst MA USA

Motivated by the small world network research of Watts ＆ Strogatz, this paper studies relationships between topology and cascading line outages in electric power grids. Cascading line outages are a type of cascading collapse that can occur in power grids when the transmission network is congested. It is characterized by a self-sustaining sequence of line outages followed by grid breakup, which generally leads to widespread blackout. The main findings of this work are twofold： On one hand, the work suggests that topologies with more disorder in their interconnection topology tend to be robust with respect to cascading line outages in the sense of being able to support greater generation and demand levels than more regularly interconnected topologies. On the other hand, the work suggests that topologies with more disorder tend to be more fragile in that should a cascade get started, they tend to break apart after fewer outages than more regularly interconnected topologies. Thus, as has been observed in other complex networks, there appears to be a tradeoff between robustness and fragility. These results were established using synthetically generated power grid topologies and verified using the IEEE 57 bus and 188 bus power grid test cases.

关键词： Power grid blackout cascading line failure complex networks robust yet fragile

Plant cytochrome P450 plasticity and evolution

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Molecular Plant 2021年第10期14卷 1244-1265页

作者： Cecilie Cetti Hansen david R.nelson Birger lindberg Moller Daniele Werck-Reichhart Plant Biochemistry laboratory Department of Plant and Environ mental ScienceUniversity of CopenhagenCopenhage nDenmark VIllUM Research Center for Plant Plasticity University of CopenhagenCopenhagenDenmark Department of Microbiology Immunology and BiochemistryUniversity of Tennessee Health Science CenterMemphisTNUSA Institute of Plant Molecular Biology Centre National de la Recherche Scientifique(CNRS)University of StrasbourgStrasbourgFrance

The superfamily of cytochrome P450(CYP)enzymes plays key roles in plant evolution and metabolic *** review provides a status on the CYP Iandscape within green algae and land *** 11 conserved CYP clans known from vascular plants are all present in green algae and several green algaespecific clans are *** 71,72,and 85 remain the largest CYP clans and include many taxaspecific CYP(sub)families reflecting emergence of linage-specific *** features and dynamics of CYP plasticity and evolution are discussed and exemplified by selected biosynthetic *** substrate promiscuity is commonly observed for CYPs from large families,favoring retention of gene duplicates and neofunctionalization,thus seeding acquisition of new *** of biosynthetic pathways producing metabolites with sporadic distribution across plant phylogeny reveals multiple exampies of convergent evolution where CYPs have been independently recruited from the same or different CYP families,to adapt to similar environmental challenges or ecological *** only a single or a few mutations are required for functional interconversion.A compilation of functionally characterized plant CYPs is provided online through the Plant P450 Database(***/public/vgrid/PlantP450/).

关键词： land plants green algae diversificati on promiscuity neofunctionalization convergent evolution functionalities plant metabolism

Assessing the utility of dissolved organic matter photoreactivity as a predictor of in situ methylmercury concentration

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Journal of Environmental Sciences 2018年第6期30卷 160-168页

作者： Sara J.Klapstein Susan E.Ziegler david A.Risk nelson J.O'Driscoll Environmental Science Program Memorial University of Newfoundland Department of Earth Sciences St. Francis Xavier University Department of Earth and Environmental Science Acadia University

Methylmercury（MeHg） bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter（DOM） and other photoreactive ligands can convert MeHg into less toxic forms of mercury through photodemethylation. In this study, spectral changes and photoreactivity of DOM were measured to assess the potential to control photoreactions and predict in situ MeHg concentration. Water samples collected from a series of lakes in southwestern Nova Scotia in June, August, and September were exposed to controlled ultraviolet-A（UV-A） radiation for up to 24 hr. Dissolved organic matter photoreactivity, measured as the loss of absorbance at 350 nm at constant UV-A irradiation, was positively dependent on the initial DOM concentration in lake waters（r^2=0.94）. This relationship was consistent over time with both DOM concentration and photoreactivity increasing from summer into fall across lakes. lake in situ MeHg concentration was positively correlated with DOM concentration and likely catchment transport in June（r = 0.77） but not the other sampling months. Despite a consistent seasonal variation in both DOM and Fe, and their respective correlations with MeHg, no discernable seasonal trend in MeHg was observed. However, a 3-year dataset from the 6 study lakes revealed a positive correlation between DOM concentration and both Fe（r = 0.91） and MeHg concentrations（r = 0.51） suggesting a more dominant landscape mobility control on *** DOM-MeHg relationships observed in these lakes highlights the need to examine DOM photoreactivity controls on MeHg transport and availability in natural waters particularly given future climate perturbations.

关键词： Methylmercury Dissolved organic carbon Photoreactions Kejimkujik National Park Freshwater lakes

Neurotherapy for chronic headache following traumatic brain injury

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Journal of Medical Colleges of PlA(China) 2015年第2期30卷 91-95页

作者： david V.nelson Mary lee Esty Department of Psychology and Philosophy Box 2447Sam Houston State University Brain Wellness and Biofeedback Center of Washington

Background: Chronic headache following traumatic brain injury(TBI) sustained in military service, while common, is highly challenging to treat with existing pharmacologic and non-pharmacologic interventions, and it may be complicated by co-morbid posttraumatic stress. Recently, a novel form of brainwave-based intervention known as the Flexyx Neurotherapy System(FNS), which involves minute pulses of electromagnetic energy stimulation of brainwave activity, has been suggested as a means to address symptoms of TBI. This study reports on a clinical series of patients with chronic headache following service-connected TBI treated with ***: Nine veterans of the wars in Afghanistan and Iraq with moderate to severe chronic headaches following service-connected TBI complicated by posttraumatic stress symptoms were treated in 20 individual FNS sessions at the Brain Wellness and Biofeedback Center of Washington(in Bethesda, Maryland, USA). They periodically completed measures including the Brief Pain Inventory-Headache(BPI-HA), previous week worst and average pain ratings, the Posttraumatic Stress Disorder Checklist-Military version(PCl-M), and an individual treatment session numerical rating scale(NRS) for the degree of cognitive dysfunction. Data analyses included beginning-to-end of treatment t-test comparisons for the BPI-HA, PCl-M, and cognitive dysfunction NRS. Results: All beginning-to-end of treatment t-test comparisons for the BPI-HA, PCl-M, and cognitive dysfunction NRS indicated statistically significant decreases. All but one participant experienced a reduction in headaches along with reductions in posttraumatic stress and perceived cognitive dysfunction, with a subset experiencing the virtual elimination of headaches. One participant obtained modest headache relief but no improvements in posttraumatic stress or cognitive dysfunction. Conclusions: FNS may be a potentially efficacious treatment for chronic posttraumatic headache sustained in military service.

关键词： Chronic headache Posttraumatic headache Traumatic brain injury Neurotherapy Electroencephalograph(EEG) biofeedback Neurofeedback