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31.
SUMMARY: Linear regression analysis was used to describe the decline in numbers of Culicoides brevitarsis Kieffer into winter with monthly maximum, average and minimum temperatures at the southern limits to its distribution in New South Wales. From this, low temperature thresholds were derived when C brevitarsis would be absent from the field. The low minimum threshold ± 2 SE (95% Confidence Interval) of 8.1 ± 0.3°C was used with historical temperature data to estimate the last month that the species should occur (March to June) and the mean number of months (2 to 6.5) below the threshold at 17 selected sites. Probability for survival during winter at these sites was estimated from years when the number of consecutive months below the threshold was ≤ 2 months. This varied from zero to 51% depending on the location of the site. Last occurrence was 0.7 months later on average and absolute probabilities for survival ranged from zero to 100% when the temperatures were increased by an arbitrary 2°C. 相似文献
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JENNIFER L. MCILWAIN EUAN S. HARVEY SIMON GROVE GLENN SHIELL HAMED AL OUFI NASR AL JARDANI 《Fisheries Oceanography》2011,20(6):497-516
The coastal shelf of the Gulf of Oman experiences periodic upwelling events during the summer months that are driven by the southwest monsoon. It is unclear what role these events play in the spatial and temporal distribution of the region’s fish assemblage. We carried out trials on two different video techniques to characterize the habitat and fish assemblage along the continental shelf margin near Muscat, Oman. Exploratory surveys with a drift stereo‐video revealed three main habitat types: Sand, Reef and Megabenthos. Three areas were chosen for additional sampling using stereo‐BRUVS (‘baited’ remote underwater‐video systems). On two separate occasions (November 2005 and March 2006) replicate stereo‐BRUVS were deployed in each area stratified by the main habitat types. For each teleost and elasmobranch species encountered on the video, an estimate of total body length and the relative abundance (MaxNi) was made. The stereo‐BRUVS recorded a wide range of demersal and pelagic teleosts including species of conservation interest such as sharks, rays and groupers. The drift stereo‐video recorded significantly fewer species than the stereo‐BRUVS (N = 15 versus N = 43). Species diversity from the stereo‐BRUVS increased by 96% in March 2006 (N = 41) compared to November 2005 (N = 23), a pattern consistent at all three areas. The structure of the overall fish assemblage (using canonical analysis of principal coordinates analysis) was highly variable both in time and space. There was ample evidence of strong habitat associations, particularly with depth and seasonal shifts in abundance and diversity. We argue the upward migration of oxygen‐depleted water into the shallow depths during the late monsoon displaces the demersal fish community along this coast. 相似文献
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AL. Polizu Hildegard Greger Al. V. Alexandri 《Plant foods for human nutrition (Dordrecht, Netherlands)》1971,20(3):215-220
Summary The paper deals with studies on the dynamics of Carbaryl residue loss on apples, plums and peaches.The initial toxicant deposit ranges between 8 and 13 ppm on peaches, 2, 3 and 3, 4 ppm on apples and up to 1.5 ppm on plums. According to the dynamics of Carbaryl residue loss on fruit results a rest period of 2 days for plums, 7 days for apples and 21 days for peaches, on admitting a 2 ppm tolerance.
Presented at the Congress of Chemistry in Agriculture, Bratislava, Sept. 1969. 相似文献
Zusammenfassung Unter Berücksichtigung der Witterungsbedingungen wurde die Geschwindigkeit des Abbaus von Carbaryl-Rückständen bei Äpfeln, Pflaumen und Pfirsichen untersucht. Die anfängliche Höhe der Rückstände betrug bei Pfirsichen zwischen 8 und 13 ppm, bei Äpfeln 2,3 und 3,4 ppm und bei Pflaumen bis zu 1,5 ppm. Wird eine Toleranz von 2 ppm zugrundegelegt, ergibt sich entsprechend der Abbau-Geschwindigkeit von Carbaryl bei Früchten eine Wartezeit von 2 Tagen bei Pflaumen, 7 Tagen bei Äpfeln und 21 Tagen bei Pfirsichen.
Resume On présente de données sur la dynamique de la dégradation des résidus de Carbaryl sur pommes, prunes et pêches. Le résidu initial atteint 8–13 ppm chez les pêches, 2,3–3,4 ppm chez les pommes et 1,5 ppm chez les prunes.De cette dynamique de la dégradation des résidue sur fruits il résulte que pour les prunes l'intervalle de pause de deur jours, pour les pommes de 7 jours et pour les pêches de 25 jours dans les conditions climatiques de Roumanie.
Presented at the Congress of Chemistry in Agriculture, Bratislava, Sept. 1969. 相似文献
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Abstract HISTORY: A similar episodic neurological disorder occurred in new born lambs on two unrelated properties involving disparate breeds of sheep. Because of the number of lambs born, cross-breeding and the fact it occurred in some mating groups and not others, a dominant mode of inheritance was, initially and separately, suspected in each case. The sires of affected lambs were apparently normal. Whereas one was New Zealand Romney, the other was a composite breed with East Friesian genetics, but both rams originated from the same source property. To investigate the pathogenesis of the disorder these two rams were acquired and mated with unrelated sheep, under experimental conditions in a more controlled environment. CLINICAL FINDINGS: A proportion of lambs born to both sires exhibited a similar neurological disorder. Some lambs were noted to be abnormal at birth, both on home properties and in the experimental flock. They tended to adopt a head and neck extended posture and were slow to get to their feet and suckle when they then became more or less normal. When forced to move, they and other more robust lambs elicited an asymmetric gait, base-wide extensor hypertonia (hypometria) of thoracic limbs and flexor hypertonia (hypermetria) of pelvic limbs. In some there was nystagmus. After several metres of asymmetric ataxic gait they would fall to one side, sometimes adopting a sitting position. Recovery usually occurred in one to several minutes. As lambs aged, it became more difficult to elicit the episodes of dysfunction and by 6 months of age they appeared normal. DIAGNOSIS: The disorder was diagnosed as a dominant familial episodic cerebellovestibular ataxia inherited as a dominant trait, with incomplete penetration of observed clinical signs and variable expressivity. CLINICAL RELEVANCE: A proportion of affected lambs are likely to die in the neonatal period so the specific nature of the disorder may go unrecognised. Because of incomplete penetrance and varying expressivity, many of the lambs carrying this mutation will survive without showing clinical signs and may enter breeding flocks, where the disorder may be perpetuated and contribute to neonatal deaths. 相似文献
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本研究从哈尔滨郊区某鸡场肿头综合征( S H S)鸡分离出 3 株血清型为 O78 的埃希氏大肠杆菌( E.coli),从鞍山 S H S病料分离出 1 株血清型为 O8 的 E.coli。并证实这 4 株 E.coli 能够对 Vero 细胞产生毒性作用,与产 Vero 毒素的 E.coli一致。对哈尔滨市郊 S H S病鸡做病理组织学观察,主要变化为头部皮下组织,头盖骨气室及鼻粘膜下纤维素性化脓性炎症,水肿和大肠杆菌性肉芽肿,心、肝、肾等器官炎症变化并有大量异嗜性粒细胞和细菌团块。 相似文献