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本研究以云杉属(Picea)8个物种幼苗为例, 通过系统测定其地上、地下呼吸速率, 年均净生产力, 叶生物量以及总生物量, 研究各特性相互间的异速比例关系(Allometric Scaling Relationship)。结果表明, 1)在异化速率方面, 云杉8个物种经温度修正的平均单株地上、地下呼吸速率与相应生物量的异速指数分别为0.876和0.817;2)在同化速率方面, 平均单株叶生物量与平均单株年净生产力的异速指数为1.191, 平均单株叶生物量与其平均总生物量的异速指数为0.940, 两者的异速指数非常接近代谢异速理论对植物小个体代谢速率指数为1的预测;3)不论是植物个体平均地上生物量与地下生物量间的异速指数(1.090), 还是经温度修正的平均单株地上呼吸速率与地下呼吸速率的异速指数(1.168) 均很接近理论预测值1。  相似文献   

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The purpose of this study was to examine the allometric analysis of ciprofloxacin and enrofloxacin using pharmacokinetic data from the literature. The pharmacokinetic parameters used were half-life, clearance and volume of distribution. Relationships between body weight and the pharmacokinetic parameter were based on the empirical formula Y = aW(b), where Y is half-life, clearance or volume of distribution, W the body weight and a is an allometric coefficient (intercept) that is constant for a given drug. The exponential term b is a proportionality constant that describes the relationship between the pharmacokinetic parameter of interest and body weight. A total of 21 different species of animals were studied. Results of the allometric analyses indicated similarity between clearance and volume of distribution as they related to body weight for both drugs. Results of the current analyses indicate it is possible to use allometry to predict pharmacokinetic variables of enrofloxacin or ciprofloxacin based on body size of species. This could provide information on appropriate doses of ciprofloxacin and enrofloxacin for all species.  相似文献   

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This paper summarises the clinical findings of 9 cases of disseminated alimentary mycobacteriosis in horses presented at a Finnish referral equine hospital 2009–2014. Four of 9 horses were Standardbreds and 8/9 horses were male. The median age was 2 years, ranging from 6 months to 15 years. The duration of clinical signs before admission ranged from 2 weeks to 6 months. All horses demonstrated deterioration of the clinical signs after a protracted period of the disease and were finally subjected to euthanasia after poor response to multiple medical therapies. The most common complaints on admission were weight loss and diarrhoea (9/9), pyrexia (7/9), ventral oedema (7/9), lethargy (7/9) and inappetance (6/9). The most common clinicopathological abnormalities were hypoalbuminaemia and hyperfibrinogenaemia, which were present in all horses. Rectal biopsy specimens were examined from 5/9 horses and specimens were stained with Ziehl‐Nielsen (ZN). At rectal biopsy, mild multifocal neutrophilic or mild granulomatous proctitis was recognised in all 5 horses, but the ZN stain for mycobacteria was positive in only one biopsy. A liver biopsy was taken from one horse in which hepatomegaly was observed clinically and revealed marked granulomatous hepatitis with the presence of mycobacteria. The rectal biopsy from this horse was ZN negative. At post mortem examination, chronic, multifocal to coalescing granulomatous typhlocolitis and lymphadenitis were found in all horses with the small intestine less frequently involved. At histopathological examination of post mortem samples, a ZN stain was performed and intracellular acid‐fast bacilli were identified in macrophages and multinucleated giant cells in the large intestine, liver and lymph nodes in 9/9 horses and in the small intestine in 5/9 horses. Mycobacterium avium ssp. hominissuis was isolated in 5/9 horses from post mortem samples.  相似文献   

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Scaling in biology is usually allometric, and therefore, the size of the heart may be expressed as a power function of body weight (BW). The present research analyses the echocardiographic measurements in 68 healthy Spanish foals weighed between 70 and 347 kg in order to determine the correct scaling exponent for the allometric equation. The echocardiographic parameters measured were: left ventricular internal dimensions (LVID), free wall thickness (LVFWT), interventricular septum thickness (IVST) at systole (s) and diastole (d), EPSS (distance between the point E of the mitral valve and the interventricular septum), and aorta diameters at the level of the aortic valve (AOD), base of valve leaflets (ABS), sinus of Valsalva (ASV) and sino-tubular junction (AJT). Indices of left ventricular performance were calculated. It was found that LVIDd, IVSTs, AOD, and ASV have a relationship to BW raised to 0.300-0.368 power, whereas left ventricular end-diastolic volume and stroke volume scaled to BW raised to 0.731-0.712 power. With these data, appropriate values can be calculated for normal Spanish foals.  相似文献   

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The characteristics, history, clinical signs, treatment and outcome of nine horses with abscesses caused by Actinomyces species were reviewed. dna sequencing was used to determine the species of one of the isolates. The horses were one to 11 years of age, and the abscesses were most commonly located in the submandibular and retropharyngeal regions. The bacterium was usually cultured as the sole isolate and the horses were most often affected in the autumn. Most of the abscesses were treated with antimicrobials and drainage, but some of them recurred. The horses with submandibular abscesses had residual scar tissue that in some cases did not resolve.  相似文献   

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The amounts of specific substances needed per day that are generally thought to be nutritionally essential or conditionally important are similar among animal species when expressed per unit of energy consumed or per metabolic body size. Accordingly, a case is made that in addition to basal daily energy utilization, allometric scaling based on metabolic body size (3/4 power of mass or weight in kg) may be used to predict and compare basal nutrient requirements among widely varied species, as well as make comparative toxicological and other biological assessments and predictions. Furthermore, given the increasing evidence for allometric scaling for a broad range of biological phenomena (both empirical and theoretical) there is usually a good biological question to be answered when an organismal process deviates markedly from an allometric scale.  相似文献   

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Allometric analysis of doxycycline pharmacokinetic parameters   总被引:1,自引:0,他引:1  
Doxycycline serum concentration-time profiles and elimination half-lives in several species were evaluated by allometric techniques. Doxycycline elimination half-life increased with body weight. Interspecies scaling of total or free doxycycline serum concentration-time profiles was possible by use of Dedrick plots with the exception of doxycycline total concentrations in cats. The observed difference in cats was attributed to more extensive binding to plasma proteins.  相似文献   

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Congenital cardiac diseases in dogs: a retrospective analysis   总被引:1,自引:0,他引:1  
In a time period of 6 years, 158 congenital cardiac defects were diagnosed in 146 dogs at the Clinic for Small Animal Medicine University of Zurich. In respect to all dogs with cardiac disease, these were 23.5% of the cases. Most common defects were subaortic stenosis (SAS, 31.5%), pulmonic stenosis (PS, 23.3%), ventricular septal defect (VSD, 14.4%), patent ductus arteriosus (PDA, 13.7%) and tricuspid dysplasia (TD, 7.5%). Complex defects were found in 8.2% of the dogs. Although single dogs per breed were affected by various defects, some breed-related tendencies could be observed. We found PS more numerously in boxers and Jack Russell Terriers whereas SAS, VSD and TD were also found in breeds reported to be predisposed. Congenital cardiac defects are an important clinical entity, and knowledge of prevalence is helpful when considering the differential diagnosis and for making a tentative diagnosis in an individual case.  相似文献   

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The assessment of cutaneous microcirculation by laser-Doppler velocimetry (LDV) has been primarily limited to human studies. The purpose of this investigation was to establish normal values in various species and anatomic sites for blood flow, velocity, and volume as determined by LDV. Microcirculation was measured with a laser-Doppler velocimeter in 54 animals, 6 healthy animals from each of 9 species. The standard sites used were the buttocks, convex surface of the ear, metacarpal pad, humeroscapular junction, thoracolumbar junction, ventral portion of the abdomen, dorsal metacarpus (hooved animals), and ventral surface of the tail (horse). Significant differences in blood flow, velocity, and volume were measured between species and sites within species. The ventral portion of the abdomen consistently had the highest relative blood flow across all species except the monkey. Measurements in the canine metacarpal pad had a high SD, possibly indicating the stratum corneum and epidermis to be too thick for LDV. Our findings provide baseline data in several species, with application of LDV in comparative dermatologic research.  相似文献   

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A review of the published literature indicates that marine mammal neoplasia includes the types and distributions of tumors seen in domestic species. A routine collection of samples from marine mammal species is hampered, and, hence, the literature is principally composed of reports from early whaling expeditions, captive zoo mammals, and epizootics that affect larger numbers of animals from a specific geographic location. The latter instances are most important, because many of these long-lived, free-ranging marine mammals may act as environmental sentinels for the health of the oceans. Examination of large numbers of mortalities reveals incidental proliferative and neoplastic conditions and, less commonly, identifies specific malignant cancers that can alter population dynamics. The best example of these is the presumptive herpesvirus-associated metastatic genital carcinomas found in California sea lions. Studies of tissues from St. Lawrence estuary beluga whales have demonstrated a high incidence of neoplasia and produced evidence that environmental contamination with high levels of polychlorinated biphenols and dichlorophenyl trichloroethane might be the cause. In addition, viruses are suspected to be the cause of gastric papillomas in belugas and cutaneous papillomas in Florida manatees and harbor porpoises. While experimental laboratory procedures can further elucidate mechanisms of neoplasia, continued pathologic examination of marine mammals will also be necessary to follow trends in wild populations.  相似文献   

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To document the frequency of the different acquired cardiac diseases in the referring area of the University of Zurich, records of 474 dogs were retrospectively analysed. Most common were valvular diseases, predominantly atrioventricular valve endocardiosis (49.4%), myocardial diseases, predominantly dilated cardiomyopathy (21.1%), pericardial effusion (12.4%), mainly due to neoplasia or idiopathic pericarditis, and cardiac neoplasia without pericardial effusion (7.0%). Rare to very rare diagnoses were dirofilariosis (2.5%), endocarditis (1.1%, only 2 of these valvular), hypertrophic cardiomyopathy (0.6%) and infectious pericarditis (0.4%). Arrhythmias were found in 145 dogs, mainly tachyarrhythmias, and most commonly associated with dilated cardiomyopathy. Relevant concomitant diseases were tracheobronchial collapse and hyperadrenocorticism in dogs with mitral endocardiosis. Knowing prevalence and causes of the various cardiac and the complicating non-cardiac diseases with clinical similarities is important for formulating diagnosis and differential diagnosis.  相似文献   

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Five novel DNA-dependent DNA polymerase (Dpol) herpesviral sequences were generated using nested consensus polymerase chain reaction (PCR) in clinical samples from a harbor seal (Phoca vitulina), bottlenose dolphin (Tursiops truncatus), orca (Orcinus orca), California sea lion (Zalophus californianus), and a Phocid herpesvirus 2 (PhHV-2) isolate from a harbor seal (used as positive control). These novel sequences and other representative herpesvirus sequences were included in Bayesian and Maximum Likelihood analyses to illustrate the phylogeny of herpesviruses amongst the marine mammal host species and in comparison to those of other animals. All 19 novel and known marine mammal herpesviruses included in the analyses aligned with members of the Alphaherpesvirinae or Gammaherpesvirinae subfamilies. The novel harbor seal herpesvirus clustered with members of the Macavirus genus, subfamily Gammaherpesvirinae. The novel bottlenose dolphin herpesvirus clustered together in a monophyletic group with another delphinid alphaherpesvirus but could not be associated with an established genus. The orca herpesvirus also clustered with a delphinid alphaherpesvirus and formed a separate clade. The sea lion herpesvirus clustered with PhHV-2. PhHV-1 clustered with varicelloviruses and PhHV-2 clustered strongly in the Gammaherpesvirinae genus Percavirus. All cetacean gammaherpesviruses formed a monophyletic clade and could not be associated with an established gammaherpesviral genus.  相似文献   

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The allometric equations relating the half-life, the volume of distribution and the total body clearance of gentamicin, amikacin, tobramycin, kanamycin and apramycin to body weight for mammalian and mammalian + avian species were defined. Literature data were used as a source of comparative pharmacokinetic data. For all antibiotics examined half-life intercepts ranged from 0.49 to 1.66, slopes from 0.05 to 0.45, volume of distribution intercepts--0.13-0.75, slope-- 0.77-1.41, total body clearance intercepts--0.88-8.8 and slope--0.62-1.04. A better relationship between pharmacokinetic parameters and body weight was shown when all values were included in the allometric analysis. Different values of intercept and slope between birds and mammals were found in gentamicin and apramycin studies. In some cases, slopes and intercepts changed when all values of pharmacokinetic parameters were included. We conclude that small difference exist between pharmacokinetics of gentamicin, amikacin, tobramycin, kanamycin and apramycin. The allometric equations shown in our study provide a basis to estimate dose intervals for mammals and birds for which specific information is lacking.  相似文献   

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Thirty-six dogs were diagnosed with pancreatic abscess by the presence of purulent exudate within the parenchyma of the pancreas during exploratory laparotomy. Data regarding history, physical examination findings, clinicopathological data, diagnostic imaging findings, bacteriological culture results, abdominal drainage technique, and perioperative treatment were evaluated for factors predictive of survival. Elevated blood urea nitrogen, serum alkaline phosphatase activity, and rising bicarbonate ion concentration were each found to have statistically significant (P<0.05) influences on survival to discharge. Twenty-two (71%) of 36 dogs died or were euthanized prior to discharge from the hospital.  相似文献   

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选取了南方地区常见的暖季型草坪草和具有较优良潜质昀野生草共9种,利用自然低温霜冻的田间试验方法,通过测定生理反应指标与受寒害观察相结合。结果表明,在低温条件下,相对电导率和可溶性糖含量升高,光合速率下降,寒害率增加。并对革种抗寒性进行综合比较,作出初步评价:野生假俭草11号抗寒性强,海滨雀稗、野生假俭草6号抗寒性较强,台湾草、兰引3号、钝叶草抗寒性中等,野生狗牙根5号和天堂419号抗寒性较弱,地毯草抗寒性弱。  相似文献   

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The study objective was to determine the effect of oral orbifloxacin (ORB) onantimicrobial susceptibility and composition of fecal coliforms in cats. Nine cats wererandomized to two groups administered a daily oral dose of 2.5 and 5.0 mg ORB/kg for 7days and a control group (three cats per group). Coliforms were isolated from stoolsamples and were tested for susceptibilities to ORB and 5 other drugs. ORB concentrationin feces was measured using high-performance liquid chromatography (HPLC). The coliformswere undetectable after 2 days of ORB administration, and their number increased in mostcats after termination of the administration. Furthermore, only isolates ofEscherichia coli were detected in all cats before administration, andthose of Citrobacter freundii were detected after termination of theadministration. E. coli isolates exhibited high ORB susceptibility[Minimum inhibitory concentration (MIC), ≤0.125 µg/ml]or relatively low susceptibility (MIC, 1−2 µg/ml) with asingle gyrA mutation. C. freundii isolates largelyexhibited intermediate ORB susceptibility (MIC, 4µg/ml), in addition to resistance to ampicillin andcefazolin, and harbored qnrB, but not a gyrA mutation.HPLC revealed that the peaks of mean concentration were 61.3 and 141.0µg/g in groups receiving 2.5 and 5.0 mg/kg, respectively. Our findingssuggest that oral ORB may alter the total counts and composition of fecal coliform, but isunlikely to yield highly fluoroquinolone-resistant mutants of E. coli andC. freundii in cats, possibly because of the high drug concentration infeces.  相似文献   

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