Role of phospholipase A2 in the induction of drip loss in porcine muscle     

Poulsen KA  Young JF  Theil P  Kolko M  Oksbjerg N  Lambert IH 《Journal of agricultural and food chemistry》2007,55(5):1970-1976

The role of phospholipase A2 in the induction of drip loss from pig muscle has been investigated. In samples from porcine M. longissimus dorsi, total PLA2 activity as well as mRNA and protein levels of the group VIA iPLA2 (iPLA2-VIA) increased during the initial 4 h post-mortem period. Morphological studies of porcine muscle showed that at 4 h post-mortem, gaps had formed between muscle fibers and that the sarcolemma membrane borders appeared blurred. At the same time iPLA2-VIA protein levels were increased inside muscle fibers and at the sarcolemma. iPLA2-VIA mRNA abundance in samples from different breeds of pigs with variations in drip loss revealed no clear correlation between drip loss level and iPLA2-VIA expression. Together, these data indicate that during the post-mortem period, iPLA2-VIA expression and activity is increased at the muscle fiber membranes. PLA2 activity may affect membrane permeability and consequently the progression of drip formation in porcine muscle.  相似文献   

The relative influence of catchment and site variables on fish and macroinvertebrate richness in cerrado biome streams     

Diego R. Macedo  Robert M. Hughes  Raphael Ligeiro  Wander R. Ferreira  Miriam A. Castro  Nara T. Junqueira  Deborah R. Oliveira  Kele R. Firmiano  Philip R. Kaufmann  Paulo S. Pompeu  Marcos Callisto 《Landscape Ecology》2014,29(6):1001-1016

Landscape and site-scale data analyses aid the interpretation of biological data and thereby help us develop more cost-effective natural resource management strategies. Our study focused on environmental influences on stream assemblages and we evaluated how three classes of environmental variables (geophysical landscape, land use and cover, and site habitat), influence fish and macroinvertebrate assemblage richness in the Brazilian Cerrado biome. We analyzed our data through use of multiple linear regression (MLR) models using the three classes of predictor variables alone and in combination. The four MLR models explained dissimilar amounts of benthic macroinvertebrate taxa richness (geophysical landscape R ² ≈ 35 %, land use and cover R ² ≈ 28 %, site habitat R ² ≈ 36 %, and combined R ² ≈ 51 %). For fish assemblages, geophysical landscape, land use and cover, site habitat, and combined models explained R ² ≈ 28 %, R ² ≈ 10 %, R ² ≈ 31 %, and R ² ≈ 47 % of the variability in fish species richness, respectively. We conclude that (1) environmental variables differed in the degree to which they explain assemblage richness, (2) the amounts of variance in assemblage richness explained by geophysical landscape and site habitat were similar, (3) the variables explained more variability in macroinvertebrate taxa richness than in fish species richness, and (4) all three classes of environmental variables studied were useful for explaining assemblage richness in Cerrado headwater streams. These results help us to understand the drivers of assemblage patterns at regional scales in tropical areas.  相似文献   

Phaseolus vulgaris L. Leaves Increase Short-Chain Fatty Acid (SCFA) Production,Ameliorating Early Metabolic Alterations     

Becerril-Campos  Adriana Araceli  Ocampo-Anguiano  Perla Viridiana  Mondragón-Jacobo  Candelario  Escobar-García  Konisgmar  Camacho-Barrón  Mariela  Anaya-Loyola  Miriam Aracely  Feregrino-Perez  Ana Angélica  García-Gasca  Teresa  Ahumada-Solórzano  Santiaga Marisela 《Plant foods for human nutrition (Dordrecht, Netherlands)》2022,77(3):421-426

Plant Foods for Human Nutrition - High-fat/high-fructose diets promote early metabolic disorders in weight and lipid and glucose metabolism. Bioactive compounds such as polyphenols and fiber...  相似文献   

Advances in the application of neuropeptides in insect control     

Miriam Altstein  Orna Ben-Aziz  Irit Schefler  Irina Zeltser  Chaim Gilon 《Crop Protection》2000,19(8-10):547-555

The development of a new approach for the generation of a novel type of putative insect control agents based on backbone cyclic peptidomimetic antagonists of insect-neuropeptides is reported. The approach, termed the backbone cyclic neuropetide based on autogonist (BBC-NBA) was applied to the insect pyrokinin/pheromone biosynthesis activating neuropeptide (PBAN) family as a model, and led to the discovery of a potent linear lead antagonist and several highly potent, metabolically stable BBC peptidomimetic antagonists, devoid of agonistic activity, which inhibited in vivo PBAN-mediated activities in moths.  相似文献   

采前与采后处理结合控制柿子贮藏过程中链格孢菌(Alternaria alternata)引起的黑斑病的研究     

Ilana Kobiler  Miriam Akerman  Leah Huberman  Dov Prusky 《保鲜与加工》2011,(5):54

由链格孢菌引起的黑斑病是导致以色列柿子(Diospyros kaki cv.Triumph)贮藏过程中果实品质下降、贮期缩短的主要因素。其病原真菌在采收前的果园中即开始侵染果实,但一直处于休眠状态。采收后,在0℃贮藏环境中病原菌开始繁殖,当贮藏2～3个月后,柿果表面出现黑斑症状。商业上采用二氯异氰尿酸钠片剂溶解后生成500 mg.L-1的氯水浸果,可在2个月的贮期内有效控制黑斑病的发生。然而,当贮期超过2个半月后,柿子果实的腐烂率则不断增加。在柿子采后出现黑斑症状之前病原真菌较长的潜伏期内,采前与采后阶段可采取一系列的综合技术措施,并与商业氯水浸果处理相结合来提高对贮藏柿果黑斑病的防控效果。采前处理包括柿子坐果30 d后,以1-(2-氯-4-吡啶)-3-苯基脲(CPPU)处理或采收前14 d以治疗性杀菌剂多抗霉素(polyoxin B)进行喷果处理。试验结果表明,与采后单独使用氯水浸果处理相比,将CPPU或polyoxin B处理与采后商业处理相结合,可使柿果黑斑浸染面积分别减小3%和60%;采收后贮藏期间二氯异氰尿酸钠喷雾处理或采后立即用二氯异氰尿酸钠喷果处理与采后商业氯水处理相结合比单独使用氯水处理可分别提高柿子好果率2%和10%。研究结果表明,对于具有较长潜伏侵染方式的采后病原菌来说,可应用采前和采后处理相结合的方法来提高果实的贮藏品质及减轻采后病害的发生。  相似文献   

5-HT4(a) receptors avert opioid-induced breathing depression without loss of analgesia     

Manzke T  Guenther U  Ponimaskin EG  Haller M  Dutschmann M  Schwarzacher S  Richter DW 《Science (New York, N.Y.)》2003,301(5630):226-229

Opiates are widely used analgesics in anesthesiology, but they have serious adverse effects such as depression of breathing. This is caused by direct inhibition of rhythm-generating respiratory neurons in the Pre-Boetzinger complex (PBC) of the brainstem. We report that serotonin 4(a) [5-HT4(a)] receptors are strongly expressed in respiratory PBC neurons and that their selective activation protects spontaneous respiratory activity. Treatment of rats with a 5-HT4 receptor-specific agonist overcame fentanyl-induced respiratory depression and reestablished stable respiratory rhythm without loss of fentanyl's analgesic effect. These findings imply the prospect of a fine-tuned recovery from opioid-induced respiratory depression, through adjustment of intracellular adenosine 3',5'-monophosphate levels through the convergent signaling pathways in neurons.  相似文献   

Eppendorf essay winner. Deconstructing C. elegans sensory mechanotransduction     

Goodman MB 《Science (New York, N.Y.)》2004,306(5695):427-428

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Effects of basal debris on glacier flow   总被引：1，自引：0，他引：1  

Iverson NR  Cohen D  Hooyer TS  Fischer UH  Jackson M  Moore PL  Lappegard G  Kohler J 《Science (New York, N.Y.)》2003,301(5629):81-84

Glacier movement is resisted partially by debris, either within glaciers or under glaciers in water-saturated layers. In experiments beneath a thick, sliding glacier, ice containing 2 to 11% debris exerted shear traction of 60 to 200 kilopascals on a smooth rock bed, comparable to the total shear traction beneath glaciers and contrary to the usual assumption that debris-bed friction is negligible. Imposed pore-water pressure that was 60 to 100% of the normal stress in a subglacial debris layer reduced shear traction on the debris sufficiently to halt its deformation and cause slip of ice over the debris. Slip resistance was thus less than debris shearing resistance.  相似文献   

Seawater sulfur isotope fluctuations in the Cretaceous     

Paytan A  Kastner M  Campbell D  Thiemens MH 《Science (New York, N.Y.)》2004,304(5677):1663-1665

The exogenic sulfur cycle is tightly coupled with the carbon and oxygen cycles, and therefore a central component of Earth's biogeochemistry. Here we present a high-resolution record of the sulfur isotopic composition of seawater sulfate for the Cretaceous. The general enrichment of isotopically light sulfur that prevailed during the Cretaceous may have been due to increased volcanic and hydrothermal activity. Two excursions toward isotopically lighter sulfur represent periods of lower rates of pyrite burial, implying a shift in the location of organic carbon burial to terrestrial or open-ocean settings. The concurrent changes in seawater sulfur and inorganic carbon isotopic compositions imply short-term variability in atmospheric oxygen partial pressure.  相似文献   

High-throughput mapping of a dynamic signaling network in mammalian cells     

Barrios-Rodiles M  Brown KR  Ozdamar B  Bose R  Liu Z  Donovan RS  Shinjo F  Liu Y  Dembowy J  Taylor IW  Luga V  Przulj N  Robinson M  Suzuki H  Hayashizaki Y  Jurisica I  Wrana JL 《Science (New York, N.Y.)》2005,307(5715):1621-1625

Signaling pathways transmit information through protein interaction networks that are dynamically regulated by complex extracellular cues. We developed LUMIER (for luminescence-based mammalian interactome mapping), an automated high-throughput technology, to map protein-protein interaction networks systematically in mammalian cells and applied it to the transforming growth factor-beta (TGFbeta) pathway. Analysis using self-organizing maps and k-means clustering identified links of the TGFbeta pathway to the p21-activated kinase (PAK) network, to the polarity complex, and to Occludin, a structural component of tight junctions. We show that Occludin regulates TGFbeta type I receptor localization for efficient TGFbeta-dependent dissolution of tight junctions during epithelial-to-mesenchymal transitions.  相似文献