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21.
Three 25- to 30-kg adult mongrel dogs had nonsurgical experimentally induced unilateral renal artery perforations produced by a rotating guide wire tip. The guide wire was introduced via a percutaneous femoral artery puncture. Baseline arteriograms were compared with serial postperforation arteriograms made over a three-month peirod, and the natural history and healing rate of these lesions were assessed. In the three-dog study, the renal artery perforations were self-limiting. The dogs'healing processes alone seemed adequate in preserving both renal and renal artery function.  相似文献   
22.
Johne's disease is one of the main causes of economic losses in ruminants and a major health hazard in the developing and developed world. Up till now, many microbiological, serological and molecular methods have been tried for the detection of Mycobacterium avium subsp. paratuberculosis (MAP). In this study, we attempt a PCR-based detection of IS900, distinct insertion sequences of MAP from the buffy coat of cattle (n=262) and sheep (n=78), and direct genotyping by single strand conformational polymorphism (SSCP). A total of 30 (11.45%) cattle and one sheep (1.28%) were positive for MAP-IS900. This IS900-based PCR detection proved highly specific, particularly when tested on other non-MAP strains. SSCP analysis grouped the MAP-IS900 into four distinct clusters based on different band patterns. Nucleotide sequence variability between MAPs detected from sheep (GenBank accession ) and cattle (GenBank accession -) was noticed in the study. Although, in recent years IS900-PCR-based detection of MAP from WBCs is being used in human, its use in animals is still limited. Our work not only supports its use in animals but also suggests further IS900-SSCP-based MAP-genotyping, coupled with DNA sequencing, as a promising tool for rapid and effective Johne's disease surveillance.  相似文献   
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The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 105 tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34th and 35th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.  相似文献   
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This paper will examine the augmentation of oxytocin (OT) secretion in the final day before parturition in the pig, and review the key endocrine systems of influence. Recent experiments have shown that increases in plasma OT above baseline secretion were not seen until 7 hours prior to the birth of the first piglet. Progesterone release begins to decline some days before birth and is unlikely to provide such acute control of OT release immediately before birth. The involvement of relaxin is complex but it is possible that the prepartum relaxin surge, which ends close to the OT rise, attenuates OT secretion to prevent excessive myometrial activity until cervical softening has occurred. Increasing myometrial electromyographic activity appears to be seen as relaxin concentrations decline and OT increase. Endogenous opioid peptides within the hypothalamus exert a profound influence upon OT secretion during birth, and some effects are also seen prepartum. It has been proposed that this system may allow parturition to be interrupted or slowed in response to changes in environment. The therapeutic choice of exogenous injections of OT to control the onset time of parturition will be discussed in the light of current physiological knowledge.  相似文献   
27.

Background  

Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO2 concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor) in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness.  相似文献   
28.
Our objectives were to determine the effects of early ovulation on fertility and uterine health of dairy cows. Four hundred and forty‐five Holstein cows (185 primiparous and 260 multiparous) from five herds were used. Blood samples were collected at 21, 35 and 49 days in milk (DIM) and cows were considered to be cyclic at 21 DIM (Cyc21) if serum progesterone (P4) concentration was above 1 ng/ml, cyclic by 49 DIM (Cyc49) if P4 concentration was above 1 ng/ml at 35 or 49 DIM, or not cyclic (NotCyc) if P4 concentration was below 1 ng/ml at all sample times. Endometrial cytology for diagnosis of subclinical endometritis was examined at 49 DIM in a subset of 414 cows. Cows in the group Cyc21 had increased hazard of insemination, for the first service, compared with cows in Cyc49 [hazard ratio (HR) = 1.40; 95% CI = 1.10–1.79; p = 0.006] and NotCyc (HR = 2.07; 95% CI = 1.52–2.82; p < 0.001). Cows in the Cyc49 group also had increased hazard of insemination compared with cows in the NotCyc group (HR = 1.47; 95% CI = 1.13–1.93; p = 0.005). Median days to insemination were, respectively, 71, 76 and 96 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in Cyc21 had greater first service pregnancy per AI than Cyc49 [38.6 vs 28.1%; adjusted odds ratio (AOR) = 1.67; 95% CI = 1.01–2.75; p = 0.04] and NotCyc (38.6 vs 23.6%; AOR = 2.08; 95% CI = 1.08–4.00; p = 0.03). Pregnancy per AI was similar in Cyc49 and NotCyc cows (28.1 vs 23.6%; AOR = 1.25; 95% CI = 0.70–2.24; p = 0.45). Cows in Cyc21 had increased hazard of pregnancy up to 300 DIM compared with Cyc49 (HR = 1.52; 95% CI = 1.17–1.96; p = 0.002) and NotCyc (HR = 1.98; 95% CI = 1.41–2.78; p < 0.001). Cows in Cyc49 tended to have increased hazard of pregnancy compared with NotCyc (HR = 1.31; 95% CI = 0.96–1.77; p = 0.09). Median days to pregnancy were, respectively, 103, 147 and 173 for cows in Cyc21, Cyc49 and NotCyc groups. Cows in the Cyc21 group had decreased prevalence of subclinical endometritis compared with cows in the NotCyc group (29.9 vs 43.7%; AOR = 0.53; 95% CI = 0.29–0.97; p = 0.04); however, the prevalence did not differ from the Cyc49 group (29.9 vs 39.1%; AOR = 0.68; 95% CI = 0.41–1.14; p = 0.15). Cyc49 cows had similar prevalence of subclinical endometritis compared with NotCyc cows (AOR = 0.77; 95% CI = 0.46–1.29; p = 0.32). Early postpartum ovulation was associated with improved uterine health and fertility.  相似文献   
29.
Computational experiments with the ROMUL mathematical model were performed for studying the dynamics of soil organic matter (SOM) in spruce forests of northeastern Czechia that were disturbed because of the atmospheric sulfur deposition in the second half of the 20th century. The effect of the soil acidification on the decomposition dynamics of the forest die-back in the model is of importance. Conditions of the forest productivity were found under which the SOM pool could be preserved. It was shown that, later on, the content of the litter will decrease because of the forest degradation, and the succession changes due to the effect of the contamination will affect the type of vegetation, as well as the type of soil organic matter. The total SOM content will decrease in this case. However, the maintenance of the grass productivity can slow down this process. It was noted that the quantitative prediction of the SOM dynamics requires measurements of the productivity parameters of the forest as a whole and the living ground cover, including the content of root litter, and the hydrothermal regime of the soil determining the transformation of the litter and humus.  相似文献   
30.
Abstract

TERMITES THEIR RECOGNITION AND CONTROL. W. Victor Harris. Second edition. Longman, London, 1971. pp.186, pl. 56. Price £4.50

INTEGRATED CONTROL OF PESTS IN FARM AND GARDEN. S. P. Simmonds. Devon Trust for Nature Conservation, 1972. pp. 15. Price £0.20.

CHEMICALS CONTROLLING INSECT BEHAVIOUR. Edited by Morton Beroza. Academic Press, New York and London, 1970. pp. 170. Price £4.65.

PHYTOTOXINS IN PLANT DISEASES. Edited by R. K. S. Wood, A. Ballio, and A. Graniti. Academic Press, London and New York, 1972. pp. xiii + 530. Price £8.50

HOT-WATER TREATMENT OF PLANT MATERIAL. Second Edition. Bulletin 201. Ministry of Agriculture, Fisheries and Food. HMSO, London, 1972. pp. iv + 46, pl. 4. Price £0.42.

KENYA BUSH CONTROL. Prepared by E. C. S. Little for the Government of Kenya. Funded by UNDP, FAO. Nairobi, 1972. pp. 88.

PROCEEDINGS OF THE FIRST INDONESIAN WEED SCIENCE CONFERENCE. Edited by M. Soerjani. Contribution No. 1, Weed Science Society of Indonesia, 1971. pp. 215. Price for student members of WSSI US$ 1.25; for members US$ 2.50; for non-members US$ 3.50.

PESTICIDES IN THE ENVIRONMENT. VOLUME 1, PARTS I AND II. Edited by R. White-Stevens. Marcel Dekker, Inc., New York, 1971. Part I: pp. 270, refs 655. Price £9.50. Part II: pp. 629, refs 1378. Price £13.60.

THE PROBLEMS OF PERSISTENT CHEMICALS. IMPLICATIONS OF PESTICIDES AND OTHER CHEMICALS IN THE ENVIRONMENT. Organisation for Economic Cooperation and Development, Paris, 1971. pp. 113. Price £0.92.

PESTICIDE CHEMISTRY. VOLUMES I-VI.* Proceedings of the Second International IUPAC Congress of Pesticide Chemistry, Tel-Aviv, February 1971. Edited by A. S. Tahori. Gordon and Breach Scientific Publishers Inc., London, 1972. Price for six-volume set £41.65. VOLUME I. INSECTICIDES. pp. 496. Price £8.35.

VOLUME III. CHEMICAL RELEASERS IN INSECTS. pp. viii + 227. Price £5.20.

VOLUME IV. METHODS IN RESIDUE ANALYSIS. pp. xi + 605. Price £10.40.  相似文献   
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