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1.
Gillian D Alton David L Pearl Ken G Bateman W Bruce McNab Olaf Berke 《BMC veterinary research》2010,6(1):42
Background
Ontario provincial abattoirs have the potential to be important sources of syndromic surveillance data for emerging diseases of concern to animal health, public health and food safety. The objectives of this study were to: (1) describe provincially inspected abattoirs processing cattle in Ontario in terms of the number of abattoirs, the number of weeks abattoirs process cattle, geographical distribution, types of whole carcass condemnations reported, and the distance animals are shipped for slaughter; and (2) identify various seasonal, secular, disease and non-disease factors that might bias the results of quantitative methods, such as cluster detection methods, used for food animal syndromic surveillance. 相似文献2.
Karen L. Lindsay Christian Hellmuth Olaf Uhl Claudia Buss Pathik D. Wadhwa Berthold Koletzko Sonja Entringer 《PloS one》2015,10(12)
Pregnancy is characterized by a complexity of metabolic processes that may impact fetal development and ultimately, infant health outcomes. However, our understanding of whole body maternal and fetal metabolism during this critical life stage remains incomplete. The objective of this study is to utilize metabolomics to profile longitudinal patterns of fasting maternal metabolites among a cohort of non-diabetic, healthy pregnant women in order to advance our understanding of changes in protein and lipid concentrations across gestation, the biochemical pathways by which they are metabolized and to describe variation in maternal metabolites between ethnic groups. Among 160 pregnant women, amino acids, tricarboxylic acid (TCA) cycle intermediates, keto-bodies and non-esterified fatty acids were detected by liquid chromatography coupled with mass spectrometry, while polar lipids were detected through flow-injected mass spectrometry. The maternal plasma concentration of several essential and non-essential amino acids, long-chain polyunsaturated fatty acids, free carnitine, acetylcarnitine, phosphatidylcholines and sphingomyelins significantly decreased across pregnancy. Concentrations of several TCA intermediates increase as pregnancy progresses, as well as the keto-body β-hydroxybutyrate. Ratios of specific acylcarnitines used as indicators of metabolic pathways suggest a decreased beta-oxidation rate and increased carnitine palmitoyltransferase-1 enzyme activity with advancing gestation. Decreasing amino acid concentrations likely reflects placental uptake and tissue biosynthesis. The absence of any increase in plasma non-esterified fatty acids is unexpected in the catabolic phase of later pregnancy and may reflect enhanced placental fatty acid uptake and utilization for fetal tissue growth. While it appears that energy production through the TCA cycle increases as pregnancy progresses, decreasing patterns of free carnitine and acetylcarnitine as well as increased carnitine palmitoyltransferase-1 rate and β-hydroxybutyrate levels suggest a concomitant upregulation of ketogenesis to ensure sufficient energy supply in the fasting state. Several differences in metabolomic profiles between Hispanic and non-Hispanic women demonstrate phenotypic variations in prenatal metabolism which should be considered in future studies. 相似文献
3.
Productivity-diversity relationships for plants, bryophytes, lichens, and polypore fungi in six northern forest landscapes 总被引:1,自引:0,他引:1
Ivar Gjerde Magne Stersdal Jrund Rolstad Ken Olaf Storaunet Hans H. Blom Vegard Gundersen Einar Heegaard 《Ecography》2005,28(6):705-720
We investigated the relationship between site productivity and diversity of vascular plants, bryophytes, lichens, and polypore fungi in forests based on species richness data in 0.25 ha forest plots (grain size), selected from six 150–200 ha study areas (focus), and spanning over a latitudinal distance of 1350 km (extent) in Norway. We 1) searched for prevailing productivity-diversity relationships (PDRs), 2) compared PDRs among taxonomic groups and species found in different micro-habitats, and 3) investigated the effect of increasing plot (grain) size on PDRs. Using vegetation types as a surrogate for site productivity, we found a general pattern of increasing species richness with site productivity. On average total species richness doubled with a ten-fold increase in productivity. Lichens PDRs stood out as less pronounced and more variable than for other species groups investigated. PDRs of species associated with downed logs tended to level off at high-productive sites, a pattern interpreted as an effect of disturbance. Increasing the grain size >10-fold did not change the proportional difference in species richness between sites with high and low productivity. 相似文献
4.
5.
The embryonic development of total specific activities as well as of molecular forms of acetylcholinesterase (AChE, EC 3.1.1.7) and of butyrylcholinesterase (BChE, EC 3.1.1.8) have been studied in the chick brain. A comparison of the development in different brain parts shows that cholinesterases first develop in diencephalon, then in tectum and telencephalon; cholinesterase development in retina is delayed by about 2-3 days; and the development in rhombencephalon [not studied until embryonic day 6 (E6)] and cerebellum is last. Both enzymes show complex and independent developmental patterns. During the early period (E3-E7) first BChE expresses high specific activities that decline rapidly, but in contrast AChE increases more or less constantly with a short temporal delay. Thereafter the developmental courses approach a late phase (E14-E20), during which AChE reaches very high specific activities and BChE follows at much lower but about parallel levels. By extraction of tissues from brain and retina in high salt plus 1% Triton X-100, we find that both cholinesterases are present in two major molecular forms, AChE sedimenting at 5.9S and 11.6S (corresponding to G2 and G4 globular forms) and BChE at 2.9S and 10.3S (G1 and G4, globular). During development there is a continuous increase of G4 over G2 AChE, the G4 form reaching 80% in brain but only 30% in retina. The proportion of G1 BChE in brain remains almost constant at 55%, but in retina there is a drastic shift from 65% G1 before E5 to 70% G4 form at E7.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
6.
Olaf Breidbach 《Development genes and evolution》1987,196(7):450-459
Summary The fate of ascending projections of thoracic interneurons in the metamorphosing brain of Tenebrio molitor is described. Persistent brain neurons were identified and their fate is described during metamorphosis. The projection sites of ascending elements are invariable throughout metamorphosis both in quantitative and in qualitative terms. Some of these ascending neurons are serotonin-immunoreactive and this set of neurons maintains a constant projection site within the metamorphosing brain. The alterations in the projection sites of these and other ascending neurons in the ventral nerve cord were analysed experimentally. The central projection sites of these persistent ascending neurons are not important for the maintenance of their nerve cord projections throughout metamorphosis. Experimental deletion of ascending neurons which project into the suboesophageal ganglion varies the shape of persistent central neurons. 相似文献
7.
Studies to characterize the pharmacokinetics of the enantiomers of MDMA were conducted in rats using the iliac arterial cannulation. Two routes of administration, intravenous and subcutaneous, were evaluated at two dose levels for each route [20 and 40 mg/kg (+/-)-MDMA for subcutaneous, 10 and 20 mg/kg (+/-)-MDMA for intravenous administrations]. The average half-life (+/- SD) for all dosing groups was 2.5 +/- 0.8 h for (-)-(R)-MDMA and 2.2 +/- 0.8 h for (+)-(S)-MDMA. The more rapid clearance of (+)-(S)-MDMA compared with (-)-(R)-MDMA is consistent with the area under the curve (AUC) data of the parent drug and its primary metabolite MDA. The mean (+/- SD) AUC S/R ratios of MDMA and MDA were 0.70 +/- 0.05 and 3.1 +/- 0.8, respectively. Following a 20 mg/kg dose of racemic MDMA iv the mean (+/- SD) of the percent dose excreted as (-)-(R)-MDMA, (+)-(S)-MDMA, (-)-(R)-MDA, and (+)-(S)-MDA were 20 +/- 10, 12 +/- 6, 3 +/- 1, and 6 +/- 2, respectively. 相似文献
8.
Summary By use of an antiserum against the crustacean cardioactive peptide (CCAP) several types of bilaterally symmetrical neurons have been mapped quantitatively in the ventral nerve cord and in the brain of the meal beetle, Tenebrio molitor. The general architecture of these neurons was reconstructed from peroxidase-antiperoxidase-labelled whole-mount preparations. From the subesophageal to the seventh abdominal ganglia two types of neurons show a repetitive organization of contralateral projection patterns in each neuromere. The first type has few branches in the central neuropil and a distinct peripheral projection. The second type is characterized by an elaborate central branching pattern, which includes ascending and descending processes. Some of its peripheral branches were found to supply peripheral neurohemal areas. In the protocerebrum, 10 CCAP-immunoreactive neurons occur with projections into the superior median protocerebrum and the tritocerebrum. Immunopositive neurons were mapped in larval and various pupal stages, as well as in the adult. All types of identified neurons were found to persist throughout metamorphosis maintaining their essential structural and topological characteristics. The CCAP-immunoreactive neurons of T. molitor are compared with those described for the locust. Putative structural homologies of subsets of neurons in both species are discussed. 相似文献
9.
Hans Fricke Karen Hissmann Jürgen Schauer Olaf Reinicke Lutz Kasang Raphael Plante 《Environmental Biology of Fishes》1991,32(1-4):287-300
Synopsis In 1987 and 1989 coelacanths were observed for the first time in their natural habitat with the help of submersibles. Coelacanths were found between 150–253 m depth, their preferential depth seems to be around 200 m; the water temperature ranged between 16.5–22.8° C. During the day coelacanths aggregate in small non-aggressive groups in sheltered lava-caves. Caves might be a limiting factor for distribution. At night they leave the caves for hunting by drifting singly along the steep lava slopes. They migrate between different caves located within a large home range covering more than 8 km coastline. Coelacanths are site-attached, some for a period of at least 2 years. Our own observations and earlier catch records show that only the west coast of Grand Comoro is a suitable coelacanth habitat with more structural complexity and prey fish abundance than other coastlines of the island. From our survey we estimated a total coelacanth population off Grand Comoro to be 150–210 individuals; a saturated population would be 370–510 individuals. This small relict population seems to be stable. International protection of coelacanths against commercial interests is needed 相似文献
10.
Expression of monoclonal antibody-defined cell surface antigens during rat brain development 总被引:1,自引:0,他引:1
Andrea Kinder-Röhrborn Olaf Ahrens Ursula Liepelt Manfred F. Rajewsky 《Differentiation; research in biological diversity》1985,30(1):53-60
Using single-cell suspensions of mechanically dissociated, prenatal BDIX-rat brain cells (13th, 15th, and 21st days after fertilization) for immunization, we have established a collection of 37 monoclonal antibodies (Mabs) directed against neural cell surface determinants. The developmental-stage-dependent expression of cell-surface antigens recognized by these Mabs was analyzed both on plasma membranes isolated from whole brains of BDIX rats (prenatal days 13-22 and adults) using an indirect 125I solid-phase radioimmunoassay, and on intact BDIX-rat brain cells (prenatal days 13-22) using a fluorescence-activated cell sorter. Different types of developmental stage-dependent profiles of Mab binding were found, these being indicative of the presence of neural cell surface determinants whose expression increases, decreases, or does not change with brain development. Some of the Mab-binding profiles showed transient changes as a function of developmental stage. These Mabs are currently being used for the characterization, reproducible identification, and isolation of neural cell subpopulations of the developing rat brain, with the aim of investigating the cell type dependence and developmental (differentiation) stage dependence of malignant transformation following pulse exposure to the carcinogen N-ethyl-N-nitrosourea at defined stages of brain development. 相似文献