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791.
Sustained dexamethasone administration to horses results in insulin resistance, which may predispose them to laminitis. A single dose of dexamethasone is commonly used as a diagnostic aid, yet the effect of a single dose of dexamethasone on glucose homeostasis in horses is not well defined. The objective of this study was to characterize the change in glucose dynamics over time in response to a single dose of dexamethasone. A combined glucose-insulin tolerance test (CGIT) was performed on 6 adult geldings before and at 2, 24, and 72 h postdexamethasone (40 microg/kg of BW, i.v.); a minimum of 1 wk of rest was allowed between treatments. Before any treatment, the CGIT resulted in a hyperglycemic phase followed by a hypoglycemic phase. Dexamethasone affected glucose dynamics in 3 ways: 1) at 2 h, dexamethasone shortened the ascending branch of the negative phase (P < 0.001) of the test, indicating moderate insulin resistance; 2) at 24 h, dexamethasone impaired glucose clearance by extending the positive phase and eliminating the negative phase while insulin was elevated before the CGIT, indicating a decreased response to insulin; and 3) at 72 h, dexamethasone caused a deeper nadir value (P < 0.001) compared with predexamethasone, indicating an increased response to insulin. It was concluded that dexamethasone decreased the response to insulin as early as 2 h and maximally at 24 h. At 72 h, dexamethasone caused an increased response to insulin, which was unexpected.  相似文献   
792.
The objective of the study is to map citizen attitudes towards pig meat production systems, and to investigate whether these attitudes associate with pork and pork product consumption. A conjoint experiment was carried out with empirical data collected from 1931 individuals in four European countries with higher-than-average per capita meat consumption (Belgium, Denmark, Poland and Germany). The experiment was based on the following pig farming characteristics: herd size, housing and floor type, efforts to reduce the impact of the production system on the environment, animal feed designed for producing pork with specific fat content, and finally the preferred quality characteristics of the pork end-product. The results of the conjoint analysis were used for a subsequent cluster analysis in order to identify European citizen clusters. Respondents' socio-demographic profile, attitudes towards issues that are expected to influence the way people evaluate pig meat production systems, and consumption frequency of various pork products are used as background information to identify segment profiles. Pork appears to play a substantial role as a part of the diet for most respondents in the four countries of this study. The results of the conjoint experiment at the sample level show that people assigned most importance to animal and environmental well-being as criteria to discriminate between “good” and “bad” pig production practices, despite the fact that their attitudes towards environmental protection, animal welfare and industrial food production were only moderately strong. Moreover, the results of the cluster analysis allowed small-sized, clear-cut clusters of citizens to appear, which pay attention to specific pig farming attributes. In conclusion, attitudes towards environment and nature, animal welfare and the need for an environment-friendly food production were indeed related to citizens' specific attitudes towards pig farming at the cluster level. However, the relationship between citizenship and consumption behaviour was found to be weak. What people think in their role as citizens related to pig production did not appear to significantly influence their pork consumption choices.  相似文献   
793.
Aimed at elucidating intense bitter-tasting molecules in coffee, various bean ingredients were thermally treated in model experiments and evaluated for their potential to produce bitter compounds. As caffeic acid was found to generate intense bitterness reminiscent of the bitter taste of a strongly roasted espresso-type coffee, the reaction products formed were screened for bitter compounds by means of taste dilution analysis, and the most bitter tastants were isolated and purified. LC-MS/MS as well as 1-D/2-D NMR experiments enabled the identification of 10 bitter compounds with rather low recognition threshold concentrations ranging between 23 and 178 micromol/L. These bitter compounds are the previously unreported 1,3-bis(3',4'-dihydroxyphenyl) butane, trans-1,3-bis(3',4'-dihydroxyphenyl)-1-butene, and eight multiply hydroxylated phenylindanes, among which five derivatives are reported for the first time. In addition, the occurrence of each of these bitter compounds in a coffee brew was verified by means of LC-MS/MS (ESI-) operating in the multiple reaction monitoring (MRM) mode. The structures of these bitter compounds show strong evidence that they are generated by oligomerization of 4-vinylcatechol released from caffeic acid moieties upon roasting.  相似文献   
794.
Linking age-specific vital rates to population growth through demographic matrix models can enhance our understanding of crucial population processes, vital in a conservation context. The white-tailed eagle (Haliaeetus albicilla) population in the Federal State of Schleswig-Holstein, Germany, has been monitored since re-colonisation in 1947 and provides a well-documented example of a recovery. We test how demographic models capture growth trajectories of a recovering population and how applicable they are in guiding population management of endangered species. From 1947 to 1974, the population was stable but the growth rate predicted by an age-structured matrix model was −6.1% per annum. The small but stable population must have been maintained by immigration. From 1975 to 2008, observed and predicted population growths were very similar (6.7% and 4% per annum respectively). Elasticity and life-stage simulation analyses identified adult and pre-breeding survival as key vital rate elements. While the prospective analyses identified survival as the key vital rate influencing population growth, the increasing reproduction rate allowed the recovery to take place; thus caution is needed when prospective modelling makes management recommendations. Nevertheless, conservation efforts should address key mortality factors such as lead poisoning and collision with wind turbines. A logistic model predicted a maximum carrying capacity of 255 pairs for the Federal State, but using the highest currently observed density (1.4 pairs per 100 km2) and differences in habitat suitability, a more likely carrying capacity was estimated at 122 pairs. Under both scenarios, current population growth should slow soon.  相似文献   
795.
Introduction of wildlife for game restocking is one major pathway of genetic homogenization. The red-legged partridge (Alectoris rufa, Phasianidae), a small game bird native to south-western Europe, is in high demand by hunters and natural populations are constantly supplemented by commercial stocks of captive-bred individuals. Also, in recent years human-mediated hybridization with congeneric chukar partridges (Alectoris chukar: Greece, Cyprus, from Middle East to East Asia) has been frequently documented in the wild and in captivity. This study attempts to evaluate the genetic consequences of intensive captive breeding and restocking in the A. rufa species. We investigated A. rufa genetic diversity by making comparisons in both a spatial (across the entire species’ range) and a temporal framework. We accomplished this latter by comparing modern vs. ancient partridges resident in museums and collected 1856-1934, well before supplemental stocking became common. Using mtDNA we found significant changes in the haplotype profile of modern vs. ancient A. rufa, and widespread introgression with chukar genes across the entire species range only in modern representatives, with the relevant exception of Corsican populations. However, Random Amplified Polymorphic DNA (RAPD), as opposed to microsatellite DNA markers, showed also modern Corsican populations to harbour many A. rufa × A. chukar hybrids. We conclude that captive breeding programs should make strict use of time-saving and comparatively low cost DNA barcodes to minimize genetic pollution, such as those provided by diagnostic RAPD markers. We also recommend that the active ban on import of exotics and/or hybrids be extended to non-local populations. Altogether this would represent a substantial step forward to preserve A. rufa as well as other game species subjected to similar intensive management.  相似文献   
796.
This study describes the identification of six allyl esters in a garlic cheese preparation and in a commercial cream cheese. The extracts were prepared by liquid/liquid extraction and concentrated by the SAFE process. The identification of the allyl esters of acetic, butyric, hexanoic, heptanoic, octanoic, and decanoic acids is based on the correlation of their mass spectrometric data and chromatographic retention time data obtained from the extracts with those of authentic standards. In addition to the gas chromatography (GC)/mass spectrometry analysis, the flavor ingredients were characterized by GC sniffing by a trained flavorist. Some of the esters were isolated by preparative GC.  相似文献   
797.
Salmonella enterica subspecies enterica serovar Choleraesuis is rarely detected in Europe, but the clinical disease has been reported in wild boars. We describe here the clinical findings, pathologic changes, and microbiologic features of swine salmonellosis caused by S. enterica serovar Choleraesuis in weaned piglets in Serbia. In April 2019, on a large farrow-to-finish pig farm, increased mortality was reported in weaned piglets, marked by lethargy, anorexia, pyrexia, and respiratory distress. Gross pathology revealed dermal cyanosis, mesenteric lymphadenopathy, splenomegaly, hepatomegaly, interstitial pneumonia, and colitis. By direct culturing of lung, liver, spleen, and lymph nodes, S. enterica ser. Choleraesuis variant Kunzendorf was isolated after years of absence of the disease in pig farms in Europe. The source of this salmonellosis outbreak caused by S. enterica ser. Choleraesuis remains unknown.  相似文献   
798.
从牙鲆(Paralichthys olivaceus)海水循环养殖系统中移动床生物滤器载体生物膜上获取异养细菌、氨化细菌和硝化细菌样本.异养细菌用平板涂布法计数,其代谢活性以培养8 h的氧吸收速率表示.氨化细菌、氨氧化细菌(AOB)和亚硝酸氧化细菌(NOB)用MPN法计数,其代谢活性分别以培养24h NH+<4>-N浓度的增加、NH+<4>-N浓度的减少和NO-<2>-N浓度的减少表示.结果表明,生物膜成熟之后,4种生理类群细菌的数量和代谢活性基本保持稳定.异养细菌数量为10-7~108CFU·m-2(载体),氨化细菌、AOB和NOB数量分别为107~108MPN·m-2(载体)、105~106MPN·m-2(载体)和105~106MPN·m-2(载体).分批培养测得异养细菌的氧吸收速率、氨化细菌的氨化速率、AOB的氨氧化速率和NOB的亚硝酸氧化速率分别是0.591~0.738g(O2)·m-2·d-1、0.081~0.135 g(Nh+4-N)·m-2.d-1、0.017~0.031 g(Nh+4-N)·m-2·d-1和0.020~0.038 g(NO-2N)·m-2·d-1.异养细菌的氧吸收速率、氨化细菌的氨化速率和AOB的氨氧化速率与异养细菌、氨化细菌和AOB的数量呈正相关.移动床生物滤器生物膜的平均氨和亚硝酸盐去除速率为(0.121±0.076)g(NH+4-N)·m-2·d-1和(0.139±0.181)g(NO-2-N)·m-2·d-1.同时测定了底物浓度和pH对氨化细菌、AOB和NOB代谢活性的影响.结果显示,氨化细菌的氨化速率、AOB的氨氧化速率和NOB的哑硝酸氧化速率与底物浓度(蛋门胨、NH+4-N和NO-2-N)呈线性相关,pH为8.0时3种生理类群细菌的代谢活性较pH6.5或pH9.5时高.[中国水产科学,2009,16(1):97-103]  相似文献   
799.
To better understand the role of lactic acid (LA) in corn wet‐milling, steeping studies were performed on different yellow dent corn hybrids using four different solutions containing LA, sulfur dioxide (SO2), a combination of LA and SO2, or no added chemicals. Although there was variation in protein solubilization among the hybrids, protein release was consistently higher when LA was included in the steepwater than when it was excluded (both with and without SO2). Several groups have reported that starch recoveries are improved when steepwater contains LA. To explore the relationship between protein solubilization and starch yield as effected by LA, several yellow dent hybrids were steeped in 0.20% SO2 and 0.50% LA‐0.20% SO2 solutions and milled to recover starch by a 100‐g laboratory corn wet‐milling procedure. In all instances, both starch yields and protein solubilization were enhanced in solutions containing LA. These results support the hypothesis that direct dissolution of the endosperm protein matrix by LA contributes to the improved starch recoveries.  相似文献   
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