Coverage of Western U accreditation questioned     

Gustafsson BK  Hooper BE  Small E 《Journal of the American Veterinary Medical Association》2001,218(3):340

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Lamprey gonadotropin-releasing hormone-III selectively releases follicle stimulating hormone in the bovine     

Dees WL  Dearth RK  Hooper RN  Brinsko SP  Romano JE  Rahe H  Yu WH  McCann SM 《Domestic animal endocrinology》2001,20(4):3791-288

Recent studies have shown that lamprey gonadotropin-releasing hormone (l-GnRH) is localized in the mammalian brain, and that l-GnRH-III, can selectively induce FSH secretion in the rat both in vivo and in vitro. Consequently, the purpose of this study was to determine if l-GnRH-III could elicit selective FSH release in cattle and compare this response with that to mammalian luteinizing hormone releasing hormone (m-LHRH). Cattle were chosen as the animal model because previous studies have demonstrated that FSH and LH are secreted by separate gonadotropes in that species. For these studies, crossbred cycling heifers were implanted with jugular cannulae and l-GnRH-III was infused either between Days 9–14 or on Day 20 of the estrous cycle. Blood samples were collected both before and following peptide infusion. Our results demonstrate that during Days 9–14 of the estrous cycle (luteal phase), when progesterone levels averaged between 4 and 5 ng/ml, a dose of 0.25 mg of l-GnRH-III induced the release of FSH (P < 0.05), but not LH. A 0.5 mg dose of l-GnRH-III caused a greater release of FSH (P < 0.01), but still did not induce LH release. Higher doses of the peptide were capable of significantly releasing both gonadotropins. Importantly, during the luteal phase, doses of 0.5 and 2 mg of m-LHRH were ineffective in stimulating FSH, but did elicit marked increases (P < 0.001) in LH. Again, progesterone levels averaged 4–5 pg/ml. In order to assess gonadotropin releasing ability of l-GnRH-III at a different phase of the estrous cycle, some animals were administered the peptide on Day 20, when progesterone levels were below 1.0 pg/ml. At this time, the l-GnRH-III induced the release of LH (P < 0.01), but not FSH. Overall, our results demonstrate that l-GnRH-III can selectively induce FSH in cattle during the luteal phase, whereas m-LHRH was ineffective in that regard. Furthermore, the fact that l-GnRH-III can selectively stimulate FSH when serum progesterone is high, and LH when serum progesterone is low, suggests its actions are under strong control of this steroid. We suggest the FSH releasing capacity of l-GnRH-III in cattle could render this peptide useful for enhancement of reproductive efficiency in this species.  相似文献   

AXONAL DYSTROPHY IN THE SPINAL CORDS OF CATTLE CONSUMING THE CYCAD PALM, CYCAS MEDIA   总被引：1，自引：0，他引：1  

P. T. Hooper  M.A.C.V.Sc.  Ph. D.  Susan M.  Best  B.Sc.† A. Campbell  B.V.Sc.† 《Australian veterinary journal》1974,50(4):146-149

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Hyperammonaemia and spongy degeneration of the brain in sheep affected with hepatic necrosis     

P T Hooper  S M Best  D R Murray 《Research in veterinary science》1974,16(2):216-222

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Absence of a role for selenium deficiency in the runting syndrome of broiler chickens in Australia     

I J Smart  D H Embury  D A Barr  A J Sinclair  H Karunajeewa  I Ewing  R L Reece  W M Forsyth  P T Hooper 《Avian diseases》1985,29(4):1201-1211

The role of selenium deficiency in the etiology of the runting-stunting syndrome (RSS) of broiler chickens in Australia was investigated. Commercial broiler chickens maintained on selenium-deficient developed signs consistent with selenium deficiency of exudative diathesis and markedly reduced plasma glutathione peroxidase activity, but they did not develop pancreatic atrophy and fibrosis or elevated plasma amylase activity, which are the other lesions associated with RSS. Supplementation of the diets of birds from a RSS-susceptible flock with a mixture of selenium, vitamin E, cysteine, and sulfate had no effect on the incidence of runting in the treated birds. In field outbreaks of RSS there were no observable differences between affected and unaffected birds in the concentration of selenium in tissue samples. Furthermore, evidence is presented which suggests that in cases of RSS, pancreatic atrophy and elevations in plasma amylase precede reductions in plasma glutathione peroxidase activity.  相似文献   

THE EFFECTS OF TWO SOIL TYPES ON DIFFUSION OF SOIL STERILANTS     

J. E. Peachey  D. N. Greet    D. J. Hooper  Margaret R.  Chapman 《Plant pathology》1965,14(1):36-38

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The effect of human trampling on coral reefs   总被引：1，自引：0，他引：1  

D.J. Woodland  J.N.A. Hooper 《Biological conservation》1977,11(1):1-4

While it is generally recognised that gross interference by man such as mining and dredging can lead to major changes in coral reefs, this paper shows that the more unobtrusive human activities, such as walking and collecting, can also lead to rapid alterations to the coral formation on reefs.  相似文献   

An oral bioassay for the toxicity of hydramethylnon to individual workers and queens of Argentine ants,Linepithema humile     

Linda M Hooper‐Bi  Michael K Rust 《Pest management science》2001,57(11):1011-1016

We have developed an oral bioassay to determine the toxicity of hydramethylnon to individual workers and queens of the Argentine ant, Linepithema humile. We fed seven concentrations of hydramethylnon in suspension to individual workers or queens, determined the amount of hydramethylnon ingested and evaluated the individual ants for mortality 14 days later. At concentrations ≥0.37 g liter^?1, the amount of liquid the queens ingested decreased dramatically, indicating that Argentine ant queens may detect hydramethylnon. Significantly larger volumes of the two highest concentrations of the hydramethylnon suspension were ingested by the workers, compared to the lower concentrations, suggesting that hydramethylnon may act as a feeding stimulant for the workers. Worker mortality was higher than queen mortality at the highest concentrations tested. The highest worker mortality resulted when the ants ingested 1.03 µg of hydramethylnon per mg of ant tissue. At the highest concentration (1.0 g liter^?1) tested, workers ingested almost 12 times as much active ingredient per mg of body weight as did queens, suggesting that, in order to increase mortality of queens, multiple feedings must occur. © 2001 Society of Chemical Industry  相似文献   

Assessment of clinical reasoning skills in veterinary students prior to and after the clinical year of training     

Farnsworth CC  Herman JD  Osterstock JB  Porterpan BL  Willard MD  Hooper RN  Roussel AJ  Schmitz DG  Fogelberg K  Kochevar DT 《Journal of the American Veterinary Medical Association》2008,233(6):879-882

OBJECTIVE: To examine the effect of various clinical tracks within the veterinary medical clinical curriculum at Texas A&M University on clinical diagnostic proficiency as determined by pre- and post-training assessment. We expected that the clinical track chosen by the student would impact their measured outcome with bias toward higher scores in their chosen field. DESIGN: Prospective cohort study. STUDY POPULATION: 32 students from the College of Veterinary Medicine and Biomedical Sciences at Texas A&M University. PROCEDURES: By use of standardized, written case scenarios, clinical reasoning was assessed twice: once prior to the clinical (fourth) year of the curriculum and again at completion of the clinical year. Students demonstrated their abilities to collect and organize appropriate clinical data (history, physical examination, and laboratory findings), determine clinical diagnoses, and formulate and implement acceptable treatment modalities. Data from clinical assessments were compared for a given cohort and correlated with other measures (eg, grades, standardized test scores, and species-specific curricular track). RESULTS: Differences were detected in clinical diagnostic proficiency among students in different clinical tracks and for different species groups in the case scenarios. Tracking by species group in the clinical veterinary curriculum appeared to affect development of clinical reasoning and resulted in differential proficiency among cases for differing species groups. CONCLUSIONS AND CLINICAL RELEVANCE: Differences in clinical experiences between small animal tracks and all other track opportunities (large animal, mixed animal, and alternative) influenced the development of clinical proficiency in fourth-year veterinary students during their clinical training period.  相似文献   

柑橘CsERF1基因RNAi载体的构建及转化   总被引：1，自引：0，他引：1  

张凌云  贝学军 《湖南农业大学学报(自然科学版)》2011,37(4):385-390

用RT-PCR克降柑橘的CsERF1基因cDNA序列,并连接到TA克隆载体pMD-19T上;经限制性内切酶2次双酶切,CsERF1基因的正、反向片段被分别插入到双元质粒pFGC5941查耳酮合成酶A(CHSA)内含子的两端,构成反向重复序列;经菌液PCR和测序验证,成功构建了Cs ERF1基因的RNA干涉载体;通过农杆...  相似文献