Fat mobilization in adipose tissue is promoted by adipose triglyceride lipase   总被引：3，自引：0，他引：3  

Zimmermann R  Strauss JG  Haemmerle G  Schoiswohl G  Birner-Gruenberger R  Riederer M  Lass A  Neuberger G  Eisenhaber F  Hermetter A  Zechner R 《Science (New York, N.Y.)》2004,306(5700):1383-1386

Mobilization of fatty acids from triglyceride stores in adipose tissue requires lipolytic enzymes. Dysfunctional lipolysis affects energy homeostasis and may contribute to the pathogenesis of obesity and insulin resistance. Until now, hormone-sensitive lipase (HSL) was the only enzyme known to hydrolyze triglycerides in mammalian adipose tissue. Here, we report that a second enzyme, adipose triglyceride lipase (ATGL), catalyzes the initial step in triglyceride hydrolysis. It is interesting that ATGL contains a "patatin domain" common to plant acyl-hydrolases. ATGL is highly expressed in adipose tissue of mice and humans. It exhibits high substrate specificity for triacylglycerol and is associated with lipid droplets. Inhibition of ATGL markedly decreases total adipose acyl-hydrolase activity. Thus, ATGL and HSL coordinately catabolize stored triglycerides in adipose tissue of mammals.  相似文献   

The puzzle of the missing meat:Food away from home and China’s meat statistics     

XIAO Hong-bo  CHEN Qiong  WANG Ji-min  Les Oxley  MA Heng-yun 《中国农业科学(英文版)》2015,(6)

From 1985, an increasing gap has emerged between the ofifcial statistical measures of meat production and meat con-sumption in China, which has raised concerns from many researchers using such data. In...  相似文献   

Effect of repeated heating and cooling cycles on the pasting properties of starch     

Hayfa Salman  Les Copeland 《Journal of Cereal Science》2010

The properties of starch and starch–lipid pastes have been explored using a novel extended Rapid Visco Analyser (RVA) profile, in which the heating and cooling cycles are repeated five times. Starches from four wheat varieties with amylose content ranging from 23 to 27%, and waxy starches of wheat, rice and maize were tested, alone and in mixtures with lauric acid and monopalmitin (glyceryl-1-monopalmitin). Gels of all of the starches formed and melted reproducibly during repeated heating and cooling in the RVA. The addition of lauric acid to the waxy starches had no effect on the multiple RVA profile. Monopalmitin caused an increase in viscosity during the heating stage of the second to the fifth cycles with the waxy starches, which was attributed to the presence of monopalmitin aggregates. Changes in the multiple cycle viscosity traces observed when monopalmitin or lauric acid was added to the amylose-containing starches were complex. It was concluded that RVA paste viscosities were determined by starch–lipid interactions, as well as by free lipid in the starch mixtures. The water solubility of the lipid and association of proteins with starch granules influence these interactions.  相似文献   

Amylolysis of wheat starches. II. Degradation patterns of native starch granules with varying functional properties     

Jaroslav Blazek  Les Copeland 《Journal of Cereal Science》2010

Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were employed to investigate degradation patterns of native starch granules from wheat (Triticum aestivum L.) by different starch-degrading enzymes. The starches examined were from a waxy wheat and four varieties with slightly elevated amylose content, but with different functional properties. Differences in the digestion patterns after partial α-amylolysis of starch granules were noted between the starches. The waxy starch seemed to be degraded by endocorrosion, whereas the amylose-rich starches followed a slower mode of hydrolysis starting from the granular surface. X-ray diffractograms of the amylose-rich starches were not significantly altered by 2 h of α-amylolysis, whereas partial hydrolysis of the waxy starch decreased scattering intensity at higher 2θ angles, consistent with a different mode of attack by α-amylase in the initial digestion stages of granules of waxy and amylose-rich starches. We propose these differences are due to the combined effects of the change in packing density and partial preference for hydrolysis of amorphous material. The native starch granules were also attacked by beta-amylase, isoamylase and amyloglucosidase, which indicates that α-amylase is not the only starch-degrading enzyme that is able to initiate starch hydrolysis of native granules.  相似文献   

Effect of reduced risk pesticides for use in greenhouse vegetable production on Bombus impatiens (Hymenoptera: Apidae)     

Angela E Gradish  Cynthia D Scott‐Dupree  Les Shipp  C Ron Harris  Gillian Ferguson 《Pest management science》2010,66(2):142-146

BACKGROUND: Bumble bees [Bombus impatiens (Cresson)] are widely used for supplemental pollination of greenhouse vegetables and are at risk of pesticide exposure while foraging. The objective of this study was to determine the lethal and sub‐lethal effects of four insecticides (imidacloprid, abamectin, metaflumizone and chlorantraniliprole) and three fungicides (myclobutanil, potassium bicarbonate and cyprodinil + fludioxonil) used or with potential for use in Ontario greenhouse vegetable production to B. impatiens. RESULTS: Imidacloprid, abamectin, and metaflumizone were harmful to worker bees following direct contact, while chlorantraniliprole and all fungicides tested were harmless. Worker bees fed imidacloprid‐contaminated pollen had shortened life spans and were unable to produce brood. Worker bees consumed less pollen contaminated with abamectin. Metaflumizone, chlorantraniliprole and all fungicides tested caused no sub‐lethal effects in bumble bee micro‐colonies. CONCLUSION: We conclude that the new reduced risk insecticides metaflumizone and chlorantraniliprole and the fungicides myclobutanil, potassium bicarbonate and cyprodinil + fludioxonil are safe for greenhouse use in the presence of bumble bees. This information can be used preserve greenhouse pollination programs while maintaining acceptable pest management. Copyright © 2009 Society of Chemical Industry  相似文献   

Monocephalic thoracopagus tetrabrachius in twin lambs     

Spiers ZB  Biddle AJ  Gabor MJ  Lee E  Gabor LJ 《The Canadian veterinary journal. La revue veterinaire canadienne》2010,51(9):1037-1039

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Effect of reduced risk pesticides on greenhouse vegetable arthropod biological control agents     

Gradish AE  Scott-Dupree CD  Shipp L  Harris CR  Ferguson G 《Pest management science》2011,67(1):82-86

BACKGROUND: Arthropod biological control agents (BCAs) are commonly released for greenhouse vegetable insect pest management. Nevertheless, chemicals remain a necessary control tactic for certain insect pests and diseases and they can have negative impacts on BCAs. The compatibility of some formulated reduced risk insecticides (abamectin, metaflumizone and chlorantraniliprole) and fungicides (myclobutanil, potassium bicarbonate and cyprodinil + fludioxonil) used, or with promise for use, in Canadian greenhouses with Orius insidiosus (Say), Amblyseius swirskii (Athias‐Henriot) and Eretmocerus eremicus (Rose & Zolnerovich) was determined through laboratory and greenhouse bioassays. RESULTS: Overall, the insecticides and fungicides were harmless as residues to adult BCAs. However, abamectin was slightly to moderately harmful to O. insidiosus and A. swirskii in laboratory bioassays, whereas metaflumizone was slightly harmful to E. eremicus. CONCLUSIONS: In general, these products appear safe to use prior to establishment/release of these adult BCAs. Copyright © 2010 Society of Chemical Industry  相似文献   

Estimating the importance of maternal age, size, and spawning experience to recruitment of Atlantic cod (Gadus morhua)     

Julie Palakovich Carr  Les Kaufman 《Biological conservation》2009,142(3):477-487

Empirical studies have demonstrated the importance of maternal characteristics to egg and larval viability in Atlantic cod (Gadus morhua) and other marine teleosts. The effects of these advantages on total reproductive output of individual fish have not yet been studied. A model of an Atlantic cod population was constructed to determine the contribution of offspring by spawners of different spawning experience. First-, second-, and third-time spawners consisted of cod ages 1-9 years old and experienced spawners consisted of ages 10 and 11. Experienced spawners contributed 10.1-12.4 times more offspring surviving to age 1 than did less experienced spawners. Reproductive efforts by first- and second-time spawners were relatively unimportant. These insights are at odds with traditional maximum sustainable yield based management and lax management, both of which favor a population dominated by young breeders and ignore the large per capita production of recruits by experienced spawners. To be managed for biological survival and commercial viability, northwest Atlantic cod will require legal protection to prevent the harvest of these oldest ages of cod.  相似文献   

What determines irrigation efficiency when farmers face extreme weather events? A field survey of the major wheat producing regions in China     

Chun-xiao SONG  Les Oxley  Heng-yun MA 《农业科学学报》2018,17(8):1888-1899

Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.  相似文献   

Genetic diversity and genotypic stability in <Emphasis Type="Italic">Prunus avium</Emphasis> L. at the northern parts of species distribution range     

Albin Lobo  Erik Dahl Kjær  Ditte Christina Olrik  Lars-Göran Stener  Jon Kehlet Hansen 《Annals of Forest Science》2018,75(2):62

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