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排序方式: 共有1667条查询结果,搜索用时 171 毫秒
1.
Michael G. G. Foreman Ming Guo Kyle A. Garver Dario Stucchi Peter Chandler Di Wan John Morrison Darren Tuele 《PloS one》2015,10(6)
Finite volume ocean circulation and particle tracking models are used to simulate water-borne transmission of infectious hematopoietic necrosis virus (IHNV) among Atlantic salmon (Salmo salar) farms in the Discovery Islands region of British Columbia, Canada. Historical simulations for April and July 2010 are carried out to demonstrate the seasonal impact of river discharge, wind, ultra-violet (UV) radiation, and heat flux conditions on near-surface currents, viral dispersion and survival. Numerical particles released from infected farm fish in accordance with IHNV shedding rates estimated through laboratory experiments are dispersed by model oceanic flows. Viral particles are inactivated by ambient UV radiation levels and by the natural microbial community at rates derived through laboratory studies. Viral concentration maps showing temporal and spatial changes are produced and combined with lab-determined minimum infectious dosages to estimate the infective connectivity among farms. Results demonstrate that neighbouring naïve farms can become exposed to IHNV via water-borne transport from an IHNV diseased farm, with a higher risk in April than July, and that many events in the sequence of farm outbreaks in 2001-2002 are consistent with higher risks in our farm connectivity matrix. Applications to other diseases, transfers between farmed and wild fish, and the effect of vaccinations are also discussed. 相似文献
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F Cicirata A Scrofani R Biondi A Papale 《Bollettino della Società italiana di biologia sperimentale》1983,59(9):1357-1363
Sleep spindle activity was studied on four subjects affected by pallesthesic deficit due to injury the posterior funiculi of the cord. The spindle activity was studied as density (number of spindles min.), duration and percent of sleep time utilized in spindle activity. The polygraph sleep records included EOG, EMG and 6 monopolar EEG recordings, 3 for each side, on the frontal, parietal and occipital regions. The records showed a spindle activity which was similar in different subjects and that was significantly higher than the physiological values. In fact, the spindle density was about 250%, the duration was about 130% and the spindle percent was about 280%, with respect to the physiological values assumed to be 100%. 相似文献
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G Scannapieco P Pauletto A Semplicini C Dario G Vescovo A Mazzucato A Angelini A C Pessina 《Bollettino della Società italiana di biologia sperimentale》1983,59(9):1265-1271
Male Broad Breasted White Turkeys (BBWT) represent an experimental model of arterial hypertension characterized by high levels of circulating and tissue catecholamines. We thought interesting to evaluate the efficacy of the long term treatment with different antihypertensive drugs. 59 male BBWT were studied, divided in five groups. The first group (13 animals) was treated with placebo; the second (14 animals) with oxprenolol 4 mg/Kg/q.d.; the third (10 animals) with labetalol 25 mg/Kg/q.d.; the fourth (11 animals) with verapamil 15 mg/Kg/ q.d.; the fifth (11 animals) with captopril 8 mg/Kg/ q.d. and furosemide 2,5 mg/Kg/q.d. All drugs were given p.o, from the 8th to the 33rd week of age. Weekly or every two weeks Blood Pressure (BP) and Heart Rate (HR) were measured by an indirect method. In all animals BP progressively increased and HR progressively decreased with age. Only the labetalol-treated animals showed a significant reduction of BP and HR through the study period as compared with the placebo-treated animals. These results confirm the preminent role played by the high levels of circulating catecholamines in determining and maintaining the arterial hypertension. 相似文献
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zge Karayel Francesca Tonelli Sebastian Virreira Winter Phillip E. Geyer Ying Fan Esther M. Sammler Dario R. Alessi Martin Steger Matthias Mann 《Molecular & cellular proteomics : MCP》2020,19(9):1546-1560
Highlights
- •MS-based clinical assay that accurately determines phospho Rab10 occupancy.
- •Stable isotope labeled phosphopeptide injected as a standard with endogenous tryptic phospho Rab peptide for accurate ratio determination.
- •Determination of pRab levels in neutrophils of Parkinson disease patients.
- •Relevance of pRab levels as marker of PD.
8.
Dario Cova Leonardo DE Angelis Elena Monti Francesco Piccinini 《Free radical research》1992,15(6):353-360
Previous investigations, performed on isolated rat atria, showed that the lipophylic spin-trapping agent N-tert-butyl-alpha-phenylnitrone (PBN) is able to prevent the acute cardiotoxic effects produced by doxorubicin (DXR), whereas the hydrophylic compound 5,5-dimethyl-pyrroline-N-oxide (DMPO) is inactive. The present study was designed to ascertain whether differences in the pharmacological effects of the two spin traps are related to their different subcellular distribution. Langendorff rat hearts were perfused for 60 minutes with [I4C]-DXR and either PBN or DMPO. The subcellular mapping of the three compounds was performed by measuring DXR by liquid scintillation counting, PBN by GC/MS, and DMPO by HPLC in the following isolated fractions: nuclei, mitochondria, sarcoplasmic reticulum, sarcolemma, cytosol. DMPO was shown to accumulate in the cytosolic compartment; both PBM and DXR are taken up by nuclei and mitochondria, while only trace amounts of DXR were detected in the sarcoplasmic reticulum. These results suggest that mitochondrial (and not sarcoplasmic) enzymes are mainly involved in DXR-induced free radical production, which is thought to cause the acute cardiotoxic effects of DXR. An involvement of DXR-induced free radical generation in the nuclear compartment seems unlikely in the short-term “in vitro” effects observed with the experimental model adopted for these studies, although it may play a role in the delayed pathology. 相似文献
9.
Dario L. Ringach 《Biological cybernetics》1995,73(6):561-568
A new model of smooth pursuit eye movements is presented. We begin
by formally analyzing the stability of the proportional-derivative
(PD) model of smooth pursuit eye movements using Pontryagin's
theory. The PD model is the linearized version of the nonlinear
Krauzlis-Lisberger (KL) model. We show that the PD model fails to
account for the experimentally observed dependence of the eye
velocity damping ratio and the oscillation period on the total delay
in the feedback loop. To explain the data, a new `tachometer'
feedback model, based on an efference copy signal of eye
acceleration, is proposed and analyzed by computer simulation. The
model predicts some salient features of monkey pursuit data and
suggests a functional role for the extraretinal input to the medial
superior temporal area (MST).
Received:
9 February 1995 / Accepted in revised form: 13 June
1995 相似文献
10.
We used nuclear and mitochondrial genes to generate a phylogenetic hypothesis for the Palearctic–Oriental starlings and mynas (genera Sturnus , Acridotheres , Leucopsar , Creatophora and Fregilupus : Sturnidae). Our results indicate that the group has undergone a rapid diversification in Asia since the late Miocene. A reassessment of the morphological and ecological characters used in previous taxonomic revisions shows that all characters are highly homoplastic. We suggest that the elevated morphological and ecological plasticity favoured the adaptation of starlings and mynas to the local environment, the exploitation of all niches and their successful radiation in south-east Asia. Under the current limits the genera Sturnus and Acridotheres are not monophyletic, and we propose a revised phylogenetic taxonomy for the entire clade. We confirm that the extinct Fregilupus varius is a starling and it colonized Réunion Island (Mascarenes) by transoceanic dispersal from Asia. 相似文献