A 200-second quasi-periodicity after the tidal disruption of a star by a dormant black hole     

RC Reis  JM Miller  MT Reynolds  K Gültekin  D Maitra  AL King  TE Strohmayer 《Science (New York, N.Y.)》2012,337(6097):949-951

Supermassive black holes (SMBHs; mass is greater than or approximately 10(5) times that of the Sun) are known to exist at the center of most galaxies with sufficient stellar mass. In the local universe, it is possible to infer their properties from the surrounding stars or gas. However, at high redshifts we require active, continuous accretion to infer the presence of the SMBHs, which often comes in the form of long-term accretion in active galactic nuclei. SMBHs can also capture and tidally disrupt stars orbiting nearby, resulting in bright flares from otherwise quiescent black holes. Here, we report on a ~200-second x-ray quasi-periodicity around a previously dormant SMBH located in the center of a galaxy at redshift z = 0.3534. This result may open the possibility of probing general relativity beyond our local universe.  相似文献   

Effects of nutritional plane and selenium supply during gestation on visceral organ mass and indices of intestinal growth and vascularity in primiparous ewes at parturition and during early lactation     

Meyer AM  Reed JJ  Neville TL  Taylor JB  Reynolds LP  Redmer DA  Vonnahme KA  Caton JS 《Journal of animal science》2012,90(8):2733-2749

Objectives were to investigate effects of nutritional plane and Se supply during gestation on visceral organ mass and intestinal growth and vascularization in ewes at parturition and during early lactation. Primiparous Rambouillet ewes (n = 84) were allocated to 2 × 3 × 2 factorial arrangement of treatments. Factors included dietary Se [adequate Se (ASe, 11.5 μg/kg BW) or high Se (HSe, 77.0 μg/kg BW)], nutritional plane [60% (restricted; RES), 100% (control; CON), or 140% (high; HIH)], and physiological stage at necropsy (parturition or d 20 of lactation). At parturition, lambs were removed and 42 ewes (7 per treatment) were necropsied. Remaining ewes were transitioned to a common diet which met lactation requirements and mechanically milked for 20 d. In the absence of interactions (P > 0.10), main effects are reported. At parturition, stomach complex and liver masses were greatest for HIH, intermediate for CON, and least for RES (P < 0.02). Small intestinal mass was greater (P ≤ 0.002) for HIH than RES and CON, and greater (P < 0.01) for ASe than HSe. During early lactation, RES and CON gastrointestinal masses increased disproportionally to BW (P < 0.05). At parturition, jejunal mucosal density was less (P ≤ 0.01) for RES than CON and HIH, whereas CON had greater (P < 0.003) jejunal mucosal RNA concentration and RNA:DNA than RES and HIH. Although there were no differences (P > 0.17) at parturition, jejunal cell percent proliferation was greatest in RES, intermediate in CON, and least in HIH (P ≤ 0.09) at d 20 lactation. At both stages, RES had less (P = 0.01) jejunal capillary area density than HIH and less (P ≤ 0.03) capillary surface density than CON and HIH. During lactation, jejunal capillary size was greater (P = 0.04) for ewes previously fed HSe compared with ASe. At parturition, ASe-HIH had greater (P < 0.02) jejunal mucosal endothelial nitric oxide synthase 3 mRNA than all other treatments and greater (P = 0.10) vascular endothelial growth factor (VEGF) than all treatments, except ASe-RES. In addition, CON had less (P ≤ 0.08) jejunal VEGF receptor-1 (FLT1) mRNA compared with RES and HIH, and ASe had greater (P = 0.003) FLT1 than HSe at parturition. Ewes fed HIH had greater (P = 0.04) jejunal VEGF receptor-2 mRNA compared with RES. Results indicate that maternal intestinal growth and vascularization are responsive to nutritional plane and dietary Se during gestation and undergo changes postpartum when under similar lactational management.  相似文献   

Effects of glucose, propionate and splanchnic hormones on neuropeptide mRNA concentrations in the ovine hypothalamus     

Relling AE  Lee K  Loerch SC  Reynolds CK 《Journal of animal physiology and animal nutrition》2012,96(4):648-654

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Evaluation of shock waveform configuration on the defibrillation capacity of implantable cardioverter defibrillators in dogs     

Romain Pariaut  Carley Saelinger  Jorge Vila  William Deforge  Patricia Queiroz-Williams  Hugues Beaufrère  Michael Zimmerman  Katrin Saile  Caryn A. Reynolds 《Journal of Veterinary Cardiology》2012,14(3):389-398

BackgroundImplantable cardioverter defibrillators (ICD) are programmed to detect ventricular arrhythmias and terminate them by delivering an electrical shock. A defibrillation threshold (DFT) at least 10 J below the maximum device output is recommended for successful therapy. Shock waveform configuration is a programmable parameter used to achieve a low DFT. It is hypothesized that a fixed-pulse configuration results in lower defibrillation energy requirements than a fixed-tilt configuration.Animals10 mongrel dogs.Materials and methodsICD generator and transvenous lead were surgically implanted. Defibrillation threshold was determined using a protocol guided by the upper limit of vulnerability. Fixed-pulse and fixed-tilt (50%/50%) waveform configurations were tested in a random order. Plasma cardiac troponin I (cTnI) was measured for signs of myocardial injury.ResultsThe experiment was completed in 9 dogs. Overall mean DFT value was 424 ± 88 V (9.2 ± 3.9 J). Mean differences among voltage, energy and impedance at the DFT for fixed-pulse (422 ± 97 V, 9.1 ± 4.2 J, 62.6 ± 13.8 Ω) and fixed-tilt (426 ± 83 V, 9.3 ± 3.8 J, 62.8 ± 18.5 Ω) configurations were not statistically significant (All P > 0.21). Cardiac TnI concentration changed from 0.03 ng/mL (95% CI: 0.02–0.04) at baseline to 0.11 ng/mL (95 CI: 0.08–0.16) after DFT was obtained with the first waveform configuration and 0.19 ng/mL (95% CI: 0.13–0.28) at the end of the study period. There were no significant changes in heart rate, end-tidal CO2 and blood pressure over time (all P > 0.09).ConclusionThe tested ICD device and lead placement reliably produced acceptable DFT values, based on a 10-J safety margin below the maximum device output. A benefit of fixed-pulse configuration could not be demonstrated over the standard fixed-tilt waveform. Signs of acute myocardial damage from repeated high-voltage shocks and episodes of ventricular fibrillation seemed of limited clinical significance.  相似文献   

Extraocular lymphoma in the horse     

Allison T. Schnoke  Dennis E. Brooks  David A. Wilkie  Ann E. Dwyer  Andrew G. Matthews  Brian C. Gilger  Diane V. H. Hendrix  Phillip Pickett  Magda Grauwels  Christine Monroe  Caryn E. Plummer 《Veterinary ophthalmology》2013,16(1):35-42

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Corneal stromal abscessation in two horses treated with intracorneal and subconjunctival injection of 1% voriconazole solution     

Hiroki Tsujita  Caryn E. Plummer 《Veterinary ophthalmology》2013,16(6):451-458

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Mammary gland growth and vascularity at parturition and during lactation in primiparous ewes fed differing levels of selenium and nutritional plane during gestation     

Tammi  L  Neville Allison  M  Meyer Arshi  Reyaz Pawel  B  Borowicz Dale  A  Redmer Lawrence  P  Reynolds Joel  S  Caton Kimberly  A  Vonnahme 《畜牧与生物技术杂志(英文版)》2013,(4):287-293

Background： Objectives were to examine the effects of selenium （Se） supply and maternal nutritional plane during gestation on mammary gland growth, cellular proliferation, and vascularity at parturition and d 20 of lactation. Rambouillet primiparous ewes （n = 84） were allocated to treatments in a 2 x 3 factorial. Factors were dietary Se （adequate Se [ASe, 11.5 μg/kg BW] or high Se [HSe, 77.0 μg/kg BVV]） and nutritional plane （60% IRES], 100% [CON], or 140% [EXC]）. At parturition, lambs were removed and 42 ewes （7/treatment） were necropsied. Remaining ewes were fed a common diet meeting requirements for lactation and mechanically milked twice daily until necropsy on d 20. At both necropsy periods, mammary glands were dissected and tissues harvested. Samples were analyzed for RNA, DNA, and protein content, cell proliferation, and vascularity. Where interactions were present （P 〈 0.05）, least squares means from the highest-order interaction are presented. Results： Final body weight of ewes was least （P 〈 0.002） in RES, intermediate for CON, and greatest for EXC, regardless of stage of the ewe at necropsy （parturition or d 20 of lactation）. In ewes necropsied at parturition, mammary glands were heavier （P = 0.02） in EXC compared to RES, with CON intermediate. Concentration of RNA （rag/g） was decreased （P= 0.01） in EXC compared to CON at parturition. There was a tendency （P= 0.07） for a Se by nutrition interaction in percentage of cells proliferating where ASe-EXC ewes had greater （P_〈 0.02） number of proliferating cells then all other treatments. Mammary vascular area tended （P = 0.08） to be affected by a Se by nutrition interaction where ASe-CON had less （P= 0.007） vascular area than HSe-CON ewes. In ewes necropsied at d 20 of lactation, the number of alveoli per area was decreased （P 〈- 0.05） in RES compared to CON and EXC-fed ewes. Conclusions： Results of this study indicate that proper maternal nutritional plane during gestation is important for mammary gland development, even out to d 20 of lactation.  相似文献   

Food supplementation: A tool to increase reproductive output? A case study in the threatened Florida Scrub-Jay     

Stephan J. Schoech  Eli S. Bridge  S. James Reynolds  Jonathan W. Atwell 《Biological conservation》2008,141(1):162-173

The federally threatened Florida Scrub-Jay (Aphelocoma coerulescens) has suffered dramatic losses in recent years primarily because of overdevelopment of its unique scrub habitat. Ensuring the survival of this species will require not only measures to reduce habitat loss, but also efforts to increase the numbers of birds in small scattered populations to a point at which they are resilient to extinction from stochastic population fluctuations. Here we evaluate the utility of providing supplementary food during the pre-breeding season as a means of increasing the reproductive output of Florida Scrub-Jays. Data collected from 2000 to 2007 at Archbold Biological Station in south-central Florida indicate a marked effect of supplemental feeding on reproductive output. This increased output appeared to result primarily from larger clutch sizes produced by supplemented female breeders as a result of their advanced laying. Supplementation also increased offspring survival probabilities and the early laying permitted more renesting attempts. Furthermore, annual variation in several reproductive measures was dampened in supplemented birds, suggesting that supplemental feeding may reduce environmental or stochastic effects on reproductive output. Although a number of potential problems may be associated with supplemental feeding (e.g., predator entrainment and increased opportunity for disease transmission), it can serve as a valuable tool for management agencies that wish to rapidly increase local carrying capacity. In addition, food supplementation might benefit translocation efforts both by increasing the number of potential translocation candidates from a donor population and then by supplementing the newly established population to promote rapid growth.  相似文献   

Comparison of a new blood sampling device with the vacuum tube system for plasma and hematological analyses in healthy dogs     

Reynolds BS  Boudet KG  Faucher MR  Geffre A  Germain C  Lefebvre HP 《Journal of the American Animal Hospital Association》2008,44(2):51-59

Pediatric devices based on a capillary system may provide an alternative to vacuum tubes for canine blood sampling. The potential advantages are absence of vein collapse, limited blood volume sampled, and improved safety. The aim of this study was to compare routine plasma and hematological variables in seven healthy dogs using both techniques. Five biochemical analytes were measured, and a complete hematological examination and plasma exogenous creatinine clearance test were performed. No clinically relevant difference between the two techniques was observed for any variable or functional test assessed.  相似文献   

Calf welfare.   总被引：1，自引：0，他引：1  

Carolyn Stull  Jim Reynolds 《Veterinary Clinics of North America: Food Animal Practice》2008,24(1):191-203

Many factors contribute to the well-being of calves on the commercial dairy including housing and environment; nutritional and health programs; handling and caretaker interactions; herd dynamics; and the common management practices of transportation, euthanasia, dehorning, and teat removal. Ensuring and assessing the welfare of calves on commercial dairies is a complex challenge, especially because the terminology and factors contributing to assessing animal welfare in agricultural animals, such as dairy calves, has not been clearly defined within the scientific community.  相似文献