A post-perovskite lens and D' heat flux beneath the central Pacific     

Lay T  Hernlund J  Garnero EJ  Thorne MS 《Science (New York, N.Y.)》2006,314(5803):1272-1276

Temperature gradients in a low-shear-velocity province in the lowermost mantle (D' region) beneath the central Pacific Ocean were inferred from the observation of a rapid S-wave velocity increase overlying a rapid decrease. These paired seismic discontinuities are attributed to a phase change from perovskite to post-perovskite and then back to perovskite as the temperature increases with depth. Iron enrichment could explain the occurrence of post-perovskite several hundred kilometers above the core-mantle boundary in this warm, chemically distinct province. The double phase-boundary crossing directly constrains the lowermost mantle temperature gradients. Assuming a standard but unconstrained choice of thermal conductivity, the regional core-mantle boundary heat flux (approximately 85 +/- 25 milliwatts per square meter), comparable to the average at Earth's surface, was estimated, along with a lower bound on global core-mantle boundary heat flow in the range of 13 +/- 4 terawatts. Mapped velocity-contrast variations indicate that the lens of post-perovskite minerals thins and vanishes over 1000 kilometers laterally toward the margin of the chemical distinct region as a result of a approximately 500-kelvin temperature increase.  相似文献   

Tibial dyschondroplasia-associated proteomic changes in chicken growth plate cartilage     

Rasaputra KS  Liyanage AB  Lay JO  McCarthy FM  Rath NC 《Avian diseases》2010,54(4):1166-1171

Tibial dyschondroplasia (TD) is a poultry leg problem that affects the proximal growth plate of the tibia, preventing its transition to bone. To understand the disease-induced proteomic changes, we compared the protein extracts of cartilage from normal and TD-affected growth plates. TD was induced by feeding thiram to chickens 2 wk before tissue harvest. Proteins were extracted from whole tissues and from conditioned media (CM) prepared by incubating appropriate growth plate tissues in serum-free culture medium for 48 hr. The extracts were prefractionated to contain proteins ranging between 10 and 100 kD. Equal amounts of proteins were subjected to 2D gel electrophoresis with three individual samples per group. The gels were silver stained, and digital images were compared and analyzed with Melanie software to determine differentially expressed protein spots. On comparison of two sets of gels, 47 matching spots were detected in tissue extracts and 27 in CM extracts. Among the matching spots, 12 were determined to be down-regulated in tissue extracts (P < or = 0.05) and two in CM extracts (P < or = 0.05) of TD-affected growth plates. Altogether, 32 protein spots could be identified in both tissue and CM extracts by in-gel trypsin digestion, followed by peptide mass fingerprinting and mass spectrometry (MS)/MS fragmentation. The down-regulated proteins included alpha-enolase, G protein, origin recognition complex, peptidyl prolyl isomerase, calumenin, type II collagen precursor, and the expressed sequence tag pgm2n.pk014.f20, a protein with homology to human reticulocalbin-3 (RCN3). Most of the downregulated proteins are associated with signal transduction, energy metabolism, and secretory functions that are integral to cell viability. Consistent with our earlier findings that the TD chondrocytes are nonviable, the current results suggest that thiram very likely interferes with basic metabolic functions of chondrocytes, leading to their death and, consequently, to the pathogenesis of TD.  相似文献   

Ellagitannin composition of blackberry as determined by HPLC-ESI-MS and MALDI-TOF-MS     

Hager TJ  Howard LR  Liyanage R  Lay JO  Prior RL 《Journal of agricultural and food chemistry》2008,56(3):661-669

Blackberries ( Rubus sp.) were evaluated by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) to identify the ellagitannins present in flesh, torus (receptacle tissue), and seeds. Most ellagitannins were present (or detectable) only in seed tissues. Ellagitannins identified by HPLC-ESI-MS in the seeds included pedunculagin, casuarictin/potentillin, castalagin/vescalagin, lambertianin A/sanguiin H-6, lambertianin C, and lambertianin D. For several of the ellagitannins, isomeric separation was also obtained. The MALDI-TOF-MS analysis was primarily utilized to evaluate and identify high molecular mass (>1000 Da) ellagitannins. The MALDI analysis verified the presence of the ellagitannins identified by HPLC-ESI-MS including lambertianin A/sanguiin H-6, lambertianin C, and lambertianin D, but the analysis also indicated the presence of several other compounds that were most likely ellagitannins based on the patterns observed in the masses (i.e., loss or addition of a gallic acid moiety to a known ellagitannin). This study determined the presence of several possible isomeric forms of ellagitannins previously unidentified in fruit and presents a possible analytical HPLC method for the analysis of the major ellagitannins present in the fruit.  相似文献   

Selection of probiotic bacteria for use in shrimp larviculture     

Jiin-Ju Guo  Kuan-Fu Liu  Shin-Hong Cheng  Chin-I Chang  Jiunn-Jyi Lay  Yueh-O Hsu  Jan-Yen Yang  & Tzyy-Ing Chen 《Aquaculture Research》2009,40(5):609-618

Three candidate probiotics, Bacillus foraminis, Bacillus cereus biovar toyoi and Bacillus fusiformis , were isolated from hydrogen-producing fermented solution and identified using 16S rRNA sequence analysis. Bacillus foraminis and B. cereus biovar toyoi exhibited strong antagonism against Streptococcus iniae and Photobacterium damselae subsp. piscicida in in vitro co-culture for competitive exclusion assay and then were conducted in the larviculture system of Penaeus monodon reared from zoea 1 to postlarva 1. The daily addition of B. cereus biovar toyoi resulted in significantly deleterious effects on survival ( P <0.01) whereas the daily addition of B. fusiformis showed highest survival rate (88.7±0.7%) but no statistically significant difference from control (73.3±12.1%). Bacillus fusiformis was continuously applied in the larviculture system of Litopenaeus vannamei . Administration of B. fusiformis significantly increased survival ( P <0.01) in both treatments added daily (87.9±1.7%) and every other day (54.7±1.2%), respectively, at a concentration of 10⁵ CFU mL⁻¹ over control (41.2±1.3%).  相似文献   

断奶前死亡的原因错综复杂     

仇新泉 《国外畜牧学(猪与禽)》2002,(6):32-34

由于错综复杂的原因围绕着几乎每一例断奶前死亡，所以断奶前死亡率多年来一直徘徊在10％上下。养猪者为减少断奶前死亡所能采取的措施，最重要的就是要做到母猪分娩时不离人。作者在2002北卡罗来那养猪会议上发表了本文。  相似文献   

Preliminary investigations on the effects of a Strongylus vulgaris larval extract,mononuclear factors and platelet factors on equine smooth muscle cells in vitro     

S. J. Morgan  R. W. Storts  P. C. Stromberg  B. A. Sowa  J. C. Lay 《Veterinary research communications》1989,13(6):479-489

Factors involved in the proliferation of equine vascular smooth muscle cells were studied in vitro. The most prominent proliferative responses in cultured vascular smooth muscle cells were induced by Strongylus vulgaris larval antigen extract (LAE) and platelet-derived factors. Less significant proliferative responses were obtained with conditioned media from S. vulgaris LAE stimulated and from unstimulated equine mononuclear leukocytes. Additionally, vascular smooth muscle cells exposed to S. vulgaris LAE developed numerous perinuclear vacuoles and were more spindle-shaped than control or smooth muscle cells exposed to other factors. Equine mononuclear leukocytes exposed to LAE developed prominent morphological changes, including enlargement, clumping and increased numbers of mitotic figures.  相似文献   

Effects of Newcastle disease virus infection on the binding, phagocytic, and bactericidal activities of respiratory macrophages of the turkey     

M D Ficken  J F Edwards  J C Lay 《Avian diseases》1987,31(4):888-894

Effects of Newcastle disease virus (NDV) infection on the binding, phagocytic, and bactericidal activities of turkey respiratory macrophages were studied. Respiratory macrophages of the turkey demonstrated the presence of immunoglobulin (Ig) G and complement receptors but lacked IgM receptors. Respiratory macrophages from NDV-infected turkeys showed little or no depression of binding of sheep erythrocyte-IgG complexes and sheep erythrocyte-IgM-complement complexes to their appropriate membrane receptors. In contrast, respiratory macrophages from NDV-infected turkeys showed significant (P less than or equal to 0.05) depression of phagocytosis of similar complexes. Bacterial killing by respiratory macrophages from NDV-infected turkeys was significantly (P less than or equal to 0.05) inhibited.  相似文献   

Experimental bovine respiratory syncytial virus infection in conventional calves: light microscopic lesions, microbiology, and studies on lavaged lung cells   总被引：6，自引：0，他引：6  

W L Castleman  J C Lay  E J Dubovi  D O Slauson 《American journal of veterinary research》1985,46(3):547-553

Conventionally raised male Holstein calves, 1 month of age, were infected by intranasal and intratracheal inoculation with bovine respiratory syncytial virus. Viral antigen was identified by fluorescence microscopy most commonly in the cytoplasm of tracheal and bronchial epithelial cells 3 to 5 days after inoculation. Cytoplasmic viral antigen was identified also in nasal, nasopharyngeal, bronchiolar, and alveolar epithelial cells and in alveolar macrophages. Bronchitis and tracheitis, characterized in part by epithelial necrosis, formation of syncytial epithelial cells and epithelial hyperplasia, were the most common lesions observed histologically. Rhinitis, bronchiolitis, and interstitial pneumonia were observed less frequently. Alterations were not detected in the numbers of cells recovered by bronchoalveolar lavage after inoculation. An increase in the phagocytic rate of latex beads occurred in macrophages 5 days after inoculation. Viral-induced lesions were resolved by 30 days after inoculation. The results indicated that bovine respiratory syncytial virus inoculation of calves results in reversible alterations in airway epithelial structure and in the phagocytic function of alveolar macrophages.  相似文献   

Infiltrating Foxp3+ Regulatory T cells and Histopathological Features in Canine Classical and Spermatocytic Seminomas     

JH Kim  SK Chon  KS Im  NH Kim  KW Cho  JH Sur 《Reproduction in domestic animals》2013,48(2):218-222

In humans, regulatory T (T reg) cells are known to play a critical role in both the regulation of immune homoeostasis and the progression of cancer. However, there is little information about the identification, characterization and the function of T reg cells in canine tumours. We identified T reg cells in 28 canine seminoma samples using a Forkhead box P3 (Foxp3) antibody and investigated the relationship between T reg cell infiltration and histopathological features of classical and spermatocytic seminomas (SE and SS, respectively). The Foxp3 protein showed nuclear immunostaining in infiltrating lymphocytes, and Foxp3+ cells were diffused or focally distributed in seminoma tissues. Foxp3+ cells were frequently present in the SS histotype, in seminomas that showed no evidence of tumour cell invasion into the vessels and in seminomas showing a diffuse growth pattern with three cell types. Neither the SE/SS histotype nor the histopathological features of the tumour correlated with Foxp3+ cell counts. These results indicate that Foxp3+ T reg cells may be associated with a less malignant histological phenotype or may not play a critical role in the immune response of canine seminomas. Moreover, Foxp3+ T reg cells may be associated with SS seminoma, but further studies, involving a larger number of samples, are required to better understand whether these cells play a critical role in the immune response in canine seminomas. This is the first report to demonstrate the characteristics of T reg cell infiltration in canine seminoma.  相似文献   

2004～2006年加拿大安大略省和魁北克省猪出现与严重猪圆环病毒相关疾病有关的猪圆环病毒2型新毒株     

Carman S  Cai H Y  De.Lay J  吴硕显 《国外畜牧学(猪与禽)》2009,29(3):50-51

2004年晚秋,加拿大安大略省保育和生长育肥猪发生了比通常猪圆环病毒2型（PCV-2）感染更严重的PCV-2相关疾病（PCVAD）。病变空前严重,包括弥散性支气管间质性肺炎、肉芽肿性肠炎、脉管炎、间质性肾炎和新病变脾梗塞。一些感染猪群的死亡率高达50%。此病与突然出现的聚合酶链反应（PCR）限制性片段长度多态性（RFLP）321型PCV-2变种有关。开放阅读框（ORF2）和全基因组序列的种系发生比较,显示为与以前占优势的RFLP422型病毒不同的新变种,与曾发生在法国和其他欧洲国家及亚洲国家的相似。随后的回顾性研究,与较早的RFLP422型毒株相比,猪自然感染RFLP321型的淋巴结、脾、肺、小肠和肾的组织学病变发生率有统计学的明显增加。基于淋巴结免疫组织化学（IHC）染色,猪感染RFLP321型毒株,与较早的RFLP422型毒株相比,病毒载负量也显示统计学的明显增加。RFLP321型毒株感染猪后的毒力增强,可能与新PCV-2毒株的遗传差异有关,此病毒目前为安大略和魁北克省猪占优势的PCV-2毒株。  相似文献