排序方式: 共有50条查询结果,搜索用时 10 毫秒
1.
Phongpa-Ngan P Grider A Mulligan JH Aggrey SE Wicker L 《Journal of agricultural and food chemistry》2011,59(24):13181-13187
Chickens from a randomly bred genetic line were segregated into high and low growth rates and high and low water-holding capacities (WHCs). The objective of this study was to identify protein markers associated with slow and fast growth rates and low and high WHCs from water-soluble protein (WSP) and crude myofibrillar protein (CMP) extracts of chicken breast muscle. Proteins were fractionated using two-dimensional electrophoresis, and a total of 22 protein spots were selected, excised, and analyzed by in-gel tryptic digestion and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Proteins expressed in extracts from slow and fast growth rates and low and high WHCs included metabolic enzymes, such as creatine kinase, pyruvate kinase, triosephosphate isomerase, and ubiqitin; housekeeping proteins, such as heat shock protein; contractile proteins, such as myosin heavy chain; actin; and also MHC isoforms and actin isoforms. The mass spectra of 20 protein spots significantly matched (protein score >83; P < 0.05) an online database. In CMP, there were unique proteins that were present only in the fast-growth population: gi|118099530 , gi|20664362 , gi|71895043 , gi|114794125 , gi|297343122 , and gi|71895043 . This information identified protein markers associated with growth rate and water holding capacity. Some of those protein markers could be added to the chicken database. 相似文献
2.
研究了各种营养成分和培养参数(pH,温度,氮源可利用性,C∶N,搅拌速度,接种量)对在生物反应器可控条件下利用合成培养基深层培养灵芝生产多糖的影响.所生产的多糖大部分(通常80%以上)为胞外多糖(EPS),分泌到培养液中,菌丝多糖(MAP)只占不到20%.在pH5.0条件下,总多糖(EPS和MAP)生产量和菌丝生长量最高.在28~34℃范围内,多糖产量在34℃培养条件下最高,并随着温度降低而下降.低氮条件下,菌丝生长较弱,多糖产量较低.多糖生产量(主要是胞外多糖)随着接种量的增加而提高,菌丝多糖的生产则相反.利用高效液相色谱(HPLC)凝胶层析法分离出两个胞外多糖组分,其洗脱时间为26.5和36.5 min,分子量分别为137和4.7 kDa;菌丝多糖有一个大的峰(40 min)和一个很小的峰(28 min),其分子量分别为1.57和76.6 kDa.菌丝多糖的HPLC凝胶层析色谱和从灵芝子实体中提取的多糖相似.本研究所采用的各种培养条件下生产的多糖(EPS和MAP)具有可重复性的HPLC色谱. 相似文献
3.
Huston’s Dynamic Equilibrium Hypothesis predicts that the response of biodiversity to disturbance varies with productivity.
Because disturbance is thought to break competitive advantage of dominant species in productive ecosystems, species richness
is predicted to increase with disturbance frequency in productive systems. Recovery of plant biomass following disturbance
is also predicted to be faster in productive systems. Here we provide the first test of Huston’s hypothesis in the context
of setting harvest rates in managed forests for achieving biodiversity objectives. We examined predictions relating to vegetation
and bird response to disturbance and succession in productive and less productive forests in western Oregon and Washington,
USA. We found that measurements of understory cover and shrub diversity were higher in young, productive stands than less
productive stands of similar age. Later-seral forests in productive environments (mean age = 67 years) had less variable and
more complete canopy closure than similar-age forests in less favorable settings. At the stand scale, bird abundance and richness
decreased with canopy closure in highly productive forests whereas bird abundance and richness increased with canopy closure
in less productive forests. At the landscape scale, bird abundance and richness within stands increased with increasing levels
of disturbance in the surrounding landscape within highly productive forests, whereas bird abundance and richness decreased
with increasing disturbance in the surrounding landscape within less productive forests. Our results indicate that bird response
to disturbance varies across levels of productivity and suggest that bird species abundance and associated species richness
will be maximized through relatively more frequent disturbance in highly productive systems. 相似文献
4.
5.
High field magnetic resonance imaging contributes to diagnosis of equine distal tarsus and proximal metatarsus lesions: 103 horses
下载免费PDF全文
![点击此处可从《Veterinary radiology & ultrasound》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Myra F. Barrett Kurt T. Selberg Sherry A. Johnson Jake Hersman David D. Frisbie 《Veterinary radiology & ultrasound》2018,59(5):587-596
Injury of the distal tarsus and proximal metatarsus commonly causes lameness. Magnetic resonance imaging (MRI) allows concurrent assessment of both the distal tarsal joints and suspensory ligament origin, and aids identification of lesions that may otherwise go undetected by other modalities. In this retrospective observational study, the medical records of a veterinary imaging center were searched for MRI exams of the distal tarsus and proximal metatarsus for the years 2012 through 2014. Studies for 125 limbs of 103 horses were identified and retrospectively evaluated by two board‐certified veterinary radiologists. Soft tissue and osseous changes were characterized and graded by degree of severity. The patients’ signalment, lameness severity, and results of diagnostic analgesia were recorded. Osteoarthritic changes of the distal intertarsal and tarsometatarsal joints were the most common findings. Other findings included bone marrow lesions, degenerative changes of the small cuboidal bones, subchondral cystic lesions, and intertarsal desmopathy. Suspensory ligament desmopathy was found in 53% of limbs. Fourty‐seven percent of limbs that responded to analgesia of the proximal suspensory ligament had more severe lesions in the distal tarsus. Bone marrow lesions of the third tarsal bone were the only MRI finding that correlated with grade of lameness in patients for which lameness grade was reported. The grade of lameness has a poor correlation with the severity of lesions found on MRI. The findings support the use of MRI for simultaneous evaluation of the proximal metatarsus and distal tarsus, particularly given the difficulty of lesion localization with diagnostic analgesia. 相似文献
6.
7.
良好的生物安全措施是保护母猪群免遭传染性胃肠炎危害和减轻已受该病感染猪场遭受更大损失的重要武器。 相似文献
8.
Stephen R Carpenter William A Brock Gretchen J A Hansen Jonathan F Hansen Joseph M Hennessy Daniel A Isermann Eric J Pedersen K Martin Perales Andrew L Rypel Greg G Sass Tyler D Tunney M Jake Vander Zanden 《Fish and Fisheries》2017,18(6):1150-1160
The Safe Operating Space (SOS) of a recreational fishery is the multidimensional region defined by levels of harvest, angler effort, habitat, predation and other factors in which the fishery is sustainable into the future. SOS boundaries exhibit trade‐offs such that decreases in harvest can compensate to some degree for losses of habitat, increases in predation and increasing value of fishing time to anglers. Conversely, high levels of harvest can be sustained if habitat is intact, predation is low, and value of fishing effort is moderate. The SOS approach recognizes limits in several dimensions: at overly high levels of harvest, habitat loss, predation, or value of fishing effort, the stock falls to a low equilibrium biomass. Recreational fisheries managers can influence harvest and perhaps predation, but they must cope with trends that are beyond their control such as changes in climate, loss of aquatic habitat or social factors that affect the value of fishing effort for anglers. The SOS illustrates opportunities to manage harvest or predation to maintain quality fisheries in the presence of trends in climate, social preferences or other factors that are not manageable. 相似文献
9.
Smallwood CL Hinton JP Jozwiak C Zhang W Koralek JD Eisaki H Lee DH Orenstein J Lanzara A 《Science (New York, N.Y.)》2012,336(6085):1137-1139
In high-temperature superconductivity, the process that leads to the formation of Cooper pairs, the fundamental charge carriers in any superconductor, remains mysterious. We used a femtosecond laser pump pulse to perturb superconducting Bi(2)Sr(2)CaCu(2)O(8+δ) and studied subsequent dynamics using time- and angle-resolved photoemission and infrared reflectivity probes. Gap and quasiparticle population dynamics revealed marked dependencies on both excitation density and crystal momentum. Close to the d-wave nodes, the superconducting gap was sensitive to the pump intensity, and Cooper pairs recombined slowly. Far from the nodes, pumping affected the gap only weakly, and recombination processes were faster. These results demonstrate a new window into the dynamical processes that govern quasiparticle recombination and gap formation in cuprates. 相似文献
10.