Relative adrenal insufficiency in dogs with sepsis     

Burkitt JM  Haskins SC  Nelson RW  Kass PH 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2007,21(2):226-231

BACKGROUND: A syndrome of relative adrenal insufficiency has been identified in septic humans, and is associated with hypotension and death. Relative adrenal insufficiency is generally associated with basal serum cortisol concentration within or above the reference range and a blunted cortisol response to adrenocorticotropic hormone administration. It is unknown whether relative adrenal insufficiency occurs in septic dogs. HYPOTHESIS: That relative adrenal insufficiency occurs in septic dogs, and that relative adrenal insufficiency is associated with hypotension and mortality. ANIMALS: Thirty-three septic dogs admitted to a small animal intensive care unit. METHODS: Dogs were included in the study if they had a known or suspected infectious disease and had systemic inflammatory response syndrome. Dogs were excluded if they had disease or medication history expected to affect the hypothalamic-pituitary-adrenal axis. Serum cortisol and endogenous plasma adrenocorticotropic hormone concentrations were measured before, and serum cortisol concentration measured 1 hour after, intramuscular administration of 250 microg of cosyntropin/dog. The change in cortisol concentration (delta-cortisol) before and after cosyntropin administration was determined in each dog. RESULTS: Hypotension was associated with lower delta-cortisol values (OR 1.3; CI 1.0-1.9; P = .029). delta-Cortisol cutoff of 3.0 microg/dL was most accurate for predicting hypotension, survival to discharge, and 28-day survival. The rate of death in dogs with delta-cortisol < or = 3 microg/dL was 4.1 times that of dogs with delta-cortisol > 3 microg/dL (RR 4.1; CI 1.5-12.3; P = .01). CONCLUSIONS AND CLINICAL RELEVANCE: Delta-cortisol < or = 3 microg/dL after adrenocorticotropic hormone administration is associated with systemic hypotension and decreased survival in septic dogs.  相似文献   

铅锌尾矿中砷代谢功能基因的多样性     

LI Xiaofang  Philip L. BOND  Longbin HUANG 《土壤圈》2017,27(3):630-637

Microbial activities impact arsenic (As) transformation in mine tailings substantially,yet little is understood on the functional diversity of As metabolism genes.This study explored this issue using a metagenomic approach coupled by a local BLASTN procedure established in our recent studies.An assembled metagenome,recovered from hypersaline and sulfidic mine tailings,was screened for As metabolism genes aioA,arrA,arsC and arsM.This was done using a local BLASTN procedure against databases of the As metabolism genes built in this study.Putative As metabolism genes detected in the assembled metagenome included 11 arsM,20 arsC and 1 arrA full-length sequences.Together with the rRNA-based phylogenetic profiling results,a picture depicting microbial As cycling in the tailings to the genus level was obtained.It was found that most of the dominant genera in the tailings potentially harboured the genes for As reduction and/or methylation.In particular,a typical pyrite-eater present in the tailings,Thioalkalivibrio sp.,was found to harbour not only arsC and arsM,but also arrA.These results highlight the unexpected diversity of As metabolism genes in the tailings,especially considering the extremely low species diversity therein.The microbial As cycling picture established here has potential use for guiding the purposeful manipulation of As biogeochemistry in the tailings.  相似文献   

Competition for shifting resources in the southern Benguela upwelling: Seabirds versus purse-seine fisheries     

Nicola C. Okes  Philip A.R. Hockey  Lorien Pichegru  Carl D. van der Lingen  Robert J.M. Crawford  David Grmillet 《Biological conservation》2009,142(10):2361-2368

In the southern Benguela upwelling ecosystem off the west coast of South Africa, seabird populations are decreasing dramatically because of reduced availability of pelagic fish. We tested the hypothesis that the west coast fishing industry is competing for the remaining stocks of anchovy and sardine with the largest colony of Vulnerable Cape Gannets (Morus capensis) along the Atlantic coast. Using GPS-tracking of the birds, echo-sounding of pelagic fish, and vessel log books, we located overlap areas between bird foraging ranges, pelagic fish distribution, and fishing activities. We then compared fish catches by gannets and vessels within their joint foraging zones. In October 2007, purse-seine fishing grounds and gannet foraging areas overlapped by only 13%. However, for a 1-month period, the amount of fish removed from this area by purse-seine boats amounted to 41% of the food requirements of the 72,000 gannets breeding on Malgas Island (25% of the world population). The fishery’s catch in this area is significant in terms of its potential impact on gannets, but comprises only 3.6% of total fishery catch. Based on this finding, the rapidly decreasing size of the gannet colony and the stated objectives of South Africa’s Marine Living Resources Act of 1998, the case for considering and experimenting with at-sea ‘no-take’ areas for the purse-seine fishery is strong. Efforts to establish whether ‘no-take’ fishing zones increase food availability for top predators is an important next step in conservation of the southern Benguela Ecosystem.  相似文献   

Upscaling as ecological information transfer: a simple framework with application to Arctic ecosystem carbon exchange     

Paul C. Stoy  Mathew Williams  Mathias Disney  Ana Prieto-Blanco  Brian Huntley  Robert Baxter  Philip Lewis 《Landscape Ecology》2009,24(7):971-986

Transferring ecological information across scale often involves spatial aggregation, which alters information content and may bias estimates if the scaling process is nonlinear. Here, a potential solution, the preservation of the information content of fine-scale measurements, is highlighted using modeled net ecosystem exchange (NEE) of an Arctic tundra landscape as an example. The variance of aggregated normalized difference vegetation index (NDVI), measured from an airborne platform, decreased linearly with log(scale), resulting in a linear relationship between log(scale) and the scale-wise modeled NEE estimate. Preserving three units of information, the mean, variance and skewness of fine-scale NDVI observations, resulted in upscaled NEE estimates that deviated less than 4% from the fine-scale estimate. Preserving only the mean and variance resulted in nearly 23% NEE bias, and preserving only the mean resulted in larger error and a change in sign from CO₂ sink to source. Compressing NDVI maps by 70–75% using wavelet thresholding with the Haar and Coiflet basis functions resulted in 13% NEE bias across the study domain. Applying unique scale-dependent transfer functions between NDVI and leaf area index (LAI) decreased, but did not remove, bias in modeled flux in a smaller expanse using handheld NDVI observations. Quantifying the parameters of statistical distributions to preserve ecological information reduces bias when upscaling and makes possible spatial data assimilation to further reduce errors in estimates of ecological processes across scale.  相似文献   

Chitosan as a wall material for a microencapsulated delivery system for Macrobrachium rosenbergii (de Man) larvae     

Abdulaziz Anas  Rosamma Philip  & Isaac Sarojeni Bright Singh 《Aquaculture Research》2008,39(8):885-890

Chitosan has been widely accepted as a wall material for preparing microcapsules of various purposes in human medicine. The possibility of using chitosan as a wall material for microencapsulating nutrients and drugs for aquaculture purposes, specifically to Macrobrachium rosenbergii larvae was evaluated in this study. Two types of chitosan-coated microcapsules were prepared using either acetone (MEC-A) or NaOH (MEC-N) as the cross-linking agents. They were compared with a microbound diet relative to total leaching of nutrients and free amino acids (FAA). Among the microcapsules, MEC-N showed the lowest level of total leaching of nutrients (23.3%) during 5 h of immersion in seawater and released 65% FAA after 60 min. During laboratory trials, 75% larvae had accepted the MEC-N capsule. The results of the study suggest that chitosan can be used as a wall material for preparing microcapsules to deliver drugs and nutrients to M. rosenbergii larvae.  相似文献   

Forest succession and climate variability interacted to control fire activity over the last four centuries in an Alaskan boreal landscape     

Hoecker  Tyler J.  Higuera  Philip E. 《Landscape Ecology》2019,34(2):227-241

Context

The boreal forest is globally important for its influence on Earth’s energy balance, and its sensitivity to climate change. Ecosystem functioning in boreal forests is shaped by fire activity, so anticipating the impacts of climate change requires understanding the precedence for, and consequences of, climatically induced changes in fire regimes. Long-term records of climate, fire, and vegetation are critical for gaining this understanding.

Objectives

We investigated the relative importance of climate and landscape flammability as drivers of fire activity in boreal forests by developing high-resolution records of fire history, and characterizing their centennial-scale relationships to temperature and vegetation dynamics.

Methods

We reconstructed the timing of fire activity in interior Alaska, USA, using seven lake-sediment charcoal records spanning CE 1550–2015. We developed individual and composite records of fire activity, and used correlations and qualitative comparisons to assess relationships with existing records of vegetation and climate.

Results

Our records document a dynamic relationship between climate and fire. Fire activity and temperature showed stronger coupling after ca. 1900 than in the preceding 350 yr. Biomass burning and temperatures increased concurrently during the second half of the twentieth century, to their highest point in the record. Fire activity followed pulses in black spruce establishment.

Conclusions

Fire activity was facilitated by warm temperatures and landscape-scale dominance of highly flammable mature black spruce, with a notable increase in temperature and fire activity during the twenty-first century. The results suggest that widespread burning at landscape scales is controlled by a combination of climate and vegetation dynamics that together drive flammability.

  相似文献   

A quantitative method for measuring regional economic resilience to the great recession     

Lauryn Ringwood  Philip Watson  Paul Lewin 《Growth and change》2019,50(1):381-402

Regional economic resilience can be defined as an economy’s ability to withstand and recover quickly from shocks. The ability to measure resilience is necessary to developing our understanding of what influences resilience. In this paper, we develop a new, two‐dimensional quantitative measure of resilience using observed differences between expected and actual employment in a region following a shock and distinguish the response to the shock from random variation. We demonstrate one application of this metric to US county‐level employment data to compare county responses to the 2007–2009 national recession and discuss how different regions of the United States responded to the shock of the Great Recession in terms of resilience.  相似文献   

小麦EST—SSRs分子标记的特性及其遗传作图     

张立异  Leroy  Philip  Bernard  Michel  张庆勤  Sourdille  Pierre 《麦类作物》2008,28(1):11-20

为了解普通小麦EST来源的微卫星的多样性,从大约1000个包含微卫星的ESTs中设计了300对引物,研究和评估了它们的多态性水平,并且将多态性标记加入到现有的遗传图谱中。在五种不同类型的重复单元中,三个碱基的重复单元出现最多,占到77％。几乎所有的EST—SSRs标记（99．3％）的重复单元都含有G-C碱基对。37．4％的微卫星都是四次重复。对于扩增和多态性,300对引物中有60对没有扩增,21．3％的扩增引物没能产生预期的扩增片断。58％的标记至少在所用8个材料的一个中显示出多态性。W7984和Opata组合表现出最高的多态性水平。大多数普通小麦EST—SSRs标记的重复次数小于10,并且4次重复是最为普遍的。81个新的EST—SSR位点被添加到两个已有的参照遗传图谱中（62个加到ITMI,19个加到CTCS）。研究结果表明小麦EST-SSRs标记展示了一些不同于基因组微卫星的特异特征,在标记发展和其他遗传应用中,这就使得它们能够成为一种非常有价值的资源。  相似文献   

Review of recent literature     

F. Weiss  Philip Brierley  H. M. Steece 《American Journal of Potato Research》1926,3(9):314-318

  相似文献   

Review of recent literature     

H. M. Steece  Philip Brierley  W. Stuart  Philip Brierley  H. M. Steece  F. Weiss  T. McIntosh 《American Journal of Potato Research》1926,3(8):289-299

  相似文献