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Negative consequences of positive feedbacks in US wild-fire management

Forest Ecosystems 2015年第2期2卷 57-66页

作者： David E calkin Matthew P thompson Mark A Finney Forestry Sciences Laboratory US Forest Service Rocky Mountain Research Station Fire Sciences Laboratory US Forest Service Rocky Mountain Research Station

Over the last two decades wildfire activity, damage, and management cost within the US have increased substantially. These increases have been associated with a number of factors including climate change and fuel accumulation due to a century of active fire suppression. The increased fire activity has occurred during a time of significant ex-urban development of the Wildland Urban Interface （WUI） along with increased demand on water resources originating on forested landscapes. These increased demands have put substantial pressure on federal agencies charged with wildfire management to continue and expand the century old policy of aggressive wildfire suppression. However, aggressive wildfire suppression is one of the major factors that drive the increased extent, intensity, and damage associated with the small number of large wildfires that are unable to be suppressed. In this paper we discuss the positive feedback loops that lead to demands for increasing suppression response while simultaneously increasing wildfire risk in the future. Despite a wealth of scientific research that demonstrates the limitations of the current management paradigm pressure to maintain the existing system are well entrenched and driven by the existing social systems that have evolved under our current management practice. Interestingly, US federal wildland fire policy provides considerable discretion for managers to pursue a range of management objectives however, societal expectations and existing management incentive structures result in policy implementation that is straining the resilience of fire adapted ecosystems and the communities that reside in and adjacent to them.

关键词： Wildfire suppression Wildfire paradox Wildland urban interface Resilience

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Microstructure and mechanical properties of cocrFeMnNi high entropy alloy with ultrasonic nanocrystal surface modification process

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Journal of Materials Science & Technology 2020年第22期54卷 123-130页

作者： timothy Alexander Listyawan Hyunjong Lee Nokeun Park Unhae Lee School of Materials Science and Engineering Yeungnam University280 Daehak-roCyeongsanGyeongsangbuk-do 38541Republic of Korea Advanced Process and Materials R&D Group Korea Institute of Industrial TechnologyIncheon 21999Republic of Korea Institute of Materials Technology Yeungnam University280 Daehak-roGyeongsanGyeongsangbuk-do 38541Republic of Korea POScO Technical Research Laboratories Gwangyang 57807Republic of Korea

In this study, mechanical properties improvement of equiatomic cocrFeMnNi treated with an ultrasonic nanocrystal surface modification(UNSM) was studied. The applied UNSM treatment with static loads of 10 N, 20 N, and 60 N provided a severe plastic deformation, which produced a gradient structure. The nearsurface area exhibited a high number of dislocation densities and deformation twin interaction, leading to a surface strengthening and hardness improvement of up to 112% than the deformation-free interior region. Increment of dislocation densities and deformation twin formation on the surface also enhanced the yield and ultimate tensile strength of the UNSM-treated specimens. Furthermore, the combination of hard nanocrystallites layer on the surface and ductile coarse grain in the specimen interior as a result of the UNSM treatment successfully maintained the strength–ductility balance of the cocrFeMnNi.

关键词： High-entropy alloy Ultrasonic nanocrystal surface modification Severe plastic deformation Microstructures Mechanical properties

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Alternative uses of lumen apposing metal stents

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World Journal of Gastroenterology 2020年第21期26卷 2715-2728页

作者： Prabin Sharma Thomas R Mccarty Ankit chhoda Antonio costantino caroline Loeser Thiruvengadam Muniraj Marvin Ryou christopher c.thompson Department of Gastroenterology and Hepatology Yale-New Haven Health-Bridgeport HospitalBridgeportCT 06610United States Division of Gastroenterology Hepatology and EndoscopyBrigham and Women’s HospitalHarvard Medical SchoolBostonMA 02115United States Department of Internal Medicine Yale-New Haven Health-Bridgeport HospitalBridgeportCT 06708United States Section of Digestive Diseases Yale University School of MedicineNew HavenCT 06520United States

The advent of lumen apposing metal stents(LAMS)has revolutionized the management of many complex gastroenterological conditions that previously required surgical or radiological *** procedures have garnered popularity due to their minimally invasive nature,higher technical and clinical success rate and lower rate of adverse *** virtue of their unique design,LAMS provide more efficient drainage,serve as conduit for endoscopic access,are associated with lower rates of leakage and are easy to be *** used for drainage of pancreatic fluid collections,the use of LAMS has been extended to gallbladder and biliary drainage,treatment of luminal strictures,creation of gastrointestinal fistulae,pancreaticobiliary drainage,improved access for surgically altered anatomy,and drainage of intra-abdominal and pelvic abscesses as well as post-surgical fluid *** new indications of endosonographic techniques and LAMS continue to evolve,this review summarizes the current role of LAMS in the management of these various complex conditions and also highlights clinical pearls to guide successful placement of LAMS.

关键词： Lumen apposing metal stents Walled off necrosis Gallbladder drainage Biliary drainage Gastric access temporary for endoscopy Gastric outlet obstruction Therapeutic endoscopy

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In vivo measurement of NADH fluorescence lifetime in skeletal muscle via -ber-coupled time-correlated single photon counting

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Journal of Innovative Optical Health Sciences 2024年第1期17卷 121-134页

作者： Kathryn M.Priest Jacob V.Schluns Nathania Nischal colton L.Gattis Jeffrey c.Wolchok timothy J.Muldoon Department of Biomedical Engineering University of Arkansas FayettevilleARUSA

Nicotinamide adenine dinucleotide(NADH)is a cofactor that serves to shuttle electrons during metabolic processes such as glycolysis,the tricarboxylic acid cycle,and oxidative phosphorylation(OXPHOS).NADH is autofluorescent,and itsfluorescence lifetime can be used to infer metabolic dynamics in living ***-coupled time-correlated single photon counting(TcSPc)equipped with an implantable needle probe can be used to measure NADH lifetime in vivo,enabling investigation of changing metabolic demand during muscle contraction or tissue *** study illustrates a proof of concept for point-based,minimally-invasive NADHfluorescence lifetime measurement in *** muscle loss(VML)injuries were created in the left tibialis anterior(TA)muscle of male Sprague Dawley *** lifetime measurements were collected before,during,and after a 30 s tetanic contraction in the injured and uninjured TA muscles,which was subsequently-t to a biexponential decay model to yield a metric of NADH utilization(cytoplasmic vs protein-bound NADH,the A11/A22 ratio).On average,this ratio was higher during and after contraction in uninjured muscle compared to muscle at rest,suggesting higher levels of free NADH in contracting and recovering muscle,indicating increased rates of *** injured muscle,this ratio was higher than uninjured muscle overall but decreased over time,which is consistent with current knowledge of inflammatory response to injury,suggesting tissue regeneration has *** data suggest that-ber-coupled TcSPc has the potential to measure changes in NADH binding in vivo in a minimally invasive manner that requires further investigation.

关键词： Glycolysis oxidative phosphorylation energy metabolism volumetric muscle loss

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Effect of best management practice implementation on sediment and phosphorus load reductions at subwatershed and watershed scale using SWAT model

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International Journal of Sediment Research 2016年第4期31卷 386-394页

作者： Jasmeet Lamba Anita M.thompson K.G.Karthikeyan John c.Panuska Laura W.Good Biosystems Engineering Department Auburn University Department of Soil Science University of Wisconsin-Madison Department of Biological Systems Engineering University of Wisconsin-Madison

Identification of areas contributing disproportionately high amount of pollutants(i.e.,critical source areas(cSAs)) to streams is important to efficiently and effectively target best management practices(BMPs).Process-based models are commonly used to identify cSAs and evaluate the impact of alternative management practices on pollutant load *** objective of this study was to use the Soil and Watershed Assessment Tool(SWAT) to identify cSAs at the subwatershed level and evaluate the impact of alternative BMPs on sediment and total phosphorus(TP) load reductions in the Pleasant Valley watershed(50 km~2) in South central Wisconsin(USA).The Nash-Sutcliffe efficiency,percent bias,and coefficient of determination ranged from 0.58 to 0.71,-12.87 to 38.33,and 0.67 to 0.79,respectively,indicating that SWAT was able to predict stream flow,sediment and TP loadings at a monthly time-step with sufficient *** on the SWAT simulation results,annual average(2006-2012) subwatershed yield for sediment and TP ranged from 0.06 to 3.14 tons hayrand 0.04 to1.9 kg hayr,*** croplands were the major source ofsediment and TP in this watershed(> 84%).Reduction in sediment and TP loading ranged from 66%to 99%at the subwatershed level after conversion of croplands to conservation Reserve Program(cRP) grasslands in subwatersheds identified as *** the other hand,reduction in sediment and TP loading with implementation of no-till practices ranged from only 14%to 25%.At the watershed outlet,sediment and TP loading reduction wasconversion of croplands to cRP grasslands and implementation of no-till practices because only about 8%of the watershed area was targeted for BMPs and/or resuspension of sediment deposited on the stream bed masked the downstream improvements in water quality.

关键词： SWAT critical source areas Phosphorus Sediment Tillage Watershed modeling

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New achievements in glaciology in Tibet,china

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chinese Science Bulletin 1998年第14期43卷 1231-1232页

作者： L.G.thompson

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Laser-induced Fluorescence Spectroscopy of Uranium Monofluoride

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chinese Journal of chemical Physics 2022年第5期35卷 754-763,I0011页

作者： Xi-lin Bai You-long Wang timothy c.Steimle School of Physics and Information Engineering Key Laboratory of Spectral Measurement and Analysis of Shanxi ProvinceShanxi Normal UniversityLinfen 041004China .School of Molecular Science Arizona State UniversityTempe 85287USA

The laser-induced fluorescence excitation spectra of uranium monofluoride have been recorded in the range of17000-19000 cm^(-1) using twodimensional *** resolution dispersed fluorescence spectra and time-resolved fluorescence spectroscopy were also *** rotationally resolved bands were intensively analyzed,and all bands were found to be derived from the ground state X(1)4.5 with a rotational constant of 0.23421 cm^(-1).The low-lying electronic states were observed near 435 and 651 cm^(-1) in the dispersed fluorescence spectra,which were assigned as?′=3.5 and 2.5,*** vibrational constants for the X(1)4.5 and X(1)3.5 states were *** branching ratios of the dispersed fluorescence spectra for the[18.62]3.5,[17.72]4.5,and[17.65]4.5 states were *** lifetime of332(9)ns,825(49)ns,and 433(15)ns for the[18.62]3.5,[17.72]4.5,and[17.65]4.5 states were obtained by fitting the time-resolved fluorescence spectroscopy,*** dipole moments were performed using the branching ratios and the radiative lifetimes.

关键词： Laser-induced fluorescence Uranium monofluoride Two-dimensional spectroscopy

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Physical and chemical processes promoting dominance of the toxic cyanobacterium cylindrospermopsis raciborskii

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chinese Journal of Oceanology and Limnology 2011年第4期29卷 883-891页

作者： Michele A. BURFORD timothy W. DAVIS Australian Rivers Institute Griffith University Nathan Qld. 4111 Australia

The freshwater cyanobacterium, cylindrospermopsis raciborskii （Woloszyflska） Seenayya and Subba Raju is a common species in lakes and reservoirs globally. In some areas of the world it can produce cytoand hepatotoxins （cylindrospermopsins, saxitoxins）, making blooms of this species a serious health concern for humans. In the last 10 15 years, there has been a considerable body of research conducted on the ecology, physiology and toxin production of this species and this paper reviews these studies with a focus on the cylindrospermopsin （cYN）-producing strains. c. raciborskii has low light requirements, close to neutral buoyancy, and a wide temperature tolerance, giving it the capacity to grow in many lentic waterbodies. It also has a flexible strategy with respect to nitrogen （N） utilisation; being able to switch between utilising fixed and atmospheric N as sources of N fluctuate. Additionally this species has a high phosphate （DIP） affinity and storage capacity. Like many cyanobacteria, it also has the capacity to use dissolved organic phosphorus （DOP）. changes in nutrient concentrations, light levels and temperature have also been found to affect production of the toxin cYN by this species. However, optimal toxin production does not necessarily occur when growth rates are optimal. Additionally, different strains of c. raciborskii vary in their cell quota of cYN, making it difficult to predict toxin concentrations, based on c. raciborskii cell densities. In summary, the ecological flexibility of this organism means that controlling blooms of c. raciborskii is a difficult undertaking. However, improved understanding of factors promoting the species and toxin production by genetically capable strains will lead to improved predictive models of blooms.

关键词： cyanobacteria freshwater algal toxins nutrients light temperature

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Safety of direct endoscopic necrosectomy in patients with gastric varices

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World Journal of Gastrointestinal Endoscopy 2016年第10期8卷 402-408页

作者： Andrew c Storm christopher c.thompson Department of Medicine Division of Gastroenterology Hepatology and Endoscopy Brigham and Women’s Hospital

AIM: To determine the feasibility and safety of transgastric direct endoscopic necrosectomy(DEN) in patients with walled-off necrosis(WON) and gastric varices. METHODS: A single center retrospective study of consecutive DEN for WON was performed from 2012 to 2015. All DEN cases with gastric fundal varices noted on endoscopy, computed tomography(cT) or magnetic resonance imaging(MRI) during the admission for DEN were collected for analysis. In all cases, external urethral sphincter(EUS) with doppler was used to exclude the presence of intervening gastric varices or other vascular structures prior to 19 gauge fine-needle aspiration(FNA) needle access into the cavity. The tract was serially dilated to 20 mm and was entered with an endoscope for DEN. Pigtail stents were placed to facilitate drainage of the cavity. Procedure details were recorded. comprehensive chart review was performed to evaluate for complications and WON recurrence. RESULTS: Fifteen patients who underwent DEN for WON had gastric varices at the time of their procedure. All patients had an INR 50. Of these patients, 11 had splenic vein thrombosis and 2 had portal vein thrombosis. Two patients had isolated gastric varices, type 1 and the remaining 13 had > 5 mm gastric submucosal varices on imaging by cT, MRI or EUS. No procedures were terminated without completing the DEN for any reason. One patient had self-limited intraprocedural bleeding related to balloon dilation of the tract. Two patients experienced delayed bleeding at 2 and 5 d post-op respectively. One required no therapy or intervention and the other received 1unit transfusion and had an EGD which revealed no active bleeding. Resolution rate of WON was 100%(after up to 2 additional DEN in one patient) and no patients required interventional radiology or surgical interventions. cONcLUSION: In patients with WON and gastric varices, DEN using EUS and doppler guidance may be performed safely. Successful resolution of WON doe

关键词： Necrosectomy Pancreatic necrosis Endoscopy Necrotizing pancreatitis Gastric varices Varices Walled off necrosis Walled-off necrosis Gastrointestinal hemorrhage Endoscopic ultrasound

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How territoriality affects the density of an egg predator： Habitat renovation and reintroduction as a method of conserving two endangered desert spring fish

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current Zoology 2014年第4期60卷 527-533页

作者： timothy PAcIOREK Layla AL-SHAER Murray ITZKOWITZ Department of Biological Sciences Lehigh University Bethlehem PA 18015 USA

conservation of endangered sympatric species must be carefully executed to ensure that the protection of one species does not negatively impact the survival of another. critically endangered Pecos gambusia Gambusia nobilis and Leon Springs pupfish cyprinodon bovinus, which are endemic to a threatened desert spring habitat, exemplify one such scenario. Recently, this habitat has been expanded, and captively bred c. bovinus were released to repopulate an area historically known to contain this species. A previous study suggested that G. nobilis are detrimental to c. bovinus populations, due to their tendency to congregate near spawning pairs and feed on their eggs. Whether G. nobilis are attracted to territorial c. bovinus, regardless of spawning behavior, remains unclear. To determine this, the number of G. nobilis in occupied and unoccupied breeding territories of both wild and captively bred c. bovinus was measured. Gambusia nobilis densities were similar between unoccupied and occupied territorial sites, suggesting that they do not show a preference for c. bovinus territories. Regardless of habitat location or prior captivity, territorial c. bovinus significantly excluded G. nobilis within their direct vicinity （5 cm）, but not from their entire territory. Decreased G. nobilis density within the habitat may allow c. bovinus to defend their breeding territories more readily during the summer spawning season. This study provides empirical evidence of captively raised individuals behaving similarly to wild indi- viduals upon reintroduction to their natural habitat and support for conservation methods that focus on common limiting factors between endangered species [current Zoology 60 （4）： 527-533, 2014].

关键词： Pupfish Gambusia Habitat conservation Territory Density

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