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101.
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Abstract

The blood marker iophenoxic acid, and the fluorescent dye rhodamine B, were evaluated as means of assessing bait consumption in the ferret, Mustela furo. Iophenoxic acid was elevated above baseline concentrations for a minimum of 28 days after dosing, indicating that it is a suitable medium‐term marker. Rhodamine B marked ferrets for a maximum of 7 days, and would therefore have limited operational use with feral ferrets. Iophenoxic acid was used in a field trial to assess the effectiveness of a newly developed baiting strategy for control of wild ferrets. All 21 ferrets captured after field baiting with iophenoxic acid had elevated levels of serum iodine, indicating that the newly developed baiting strategy is highly effective for marking ferrets.  相似文献   
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Eighty crossbred beef heifers were randomly allocated to four groups to evaluate the efficacy of vaccination in preventing development of calves persistently infected with bovine viral diarrhea virus (BVDV). Group 1 (n = 11) was non-vaccinated controls, whereas three groups were vaccinated with commercially available multivalent BVDV vaccines at weaning (∼7 mo of age), 28 d post-weaning, ∼1 y of age, and 28 d later. Groups 2 (n = 23) and 3 (n = 23) were given a modified-live BVDV vaccine, whereas Group 4 was given an inactivated BVDV vaccine. Heifers were bred by AI and subsequently exposed to two bulls. At 61 d after AI, 70 heifers were pregnant (n = 10 for Group 1 and n = 20/group for Groups 2, 3, and 4). Three cattle persistently infected with BVDV were commingled with the pregnant heifers (in an isolated pasture) from 68 to 126 d after AI. Thereafter, viremias were detected in pregnant heifers from Groups 1, 3, and 4 (10/10, 1/20, and 10/20, respectively), but not in pregnant heifers from Group 2 (0/20). Resulting calves were assessed for persistent infection using serum PCR, ear notch antigen capture-ELISA, and immunohistochemistry. Persistently infected calves were only produced in Group 1 (10/10) and Group 4 (2/18). In conclusion, commercial vaccines provided effective fetal protection despite prolonged natural exposure to BVDV. Given that viremias were detected in 11 vaccinated heifers after BVDV exposure, and two vaccinated heifers gave birth to persistently infected calves, there is continued need for biosecurity and diagnostic surveillance, in addition to vaccination, to ensure effective BVDV control.  相似文献   
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Despite the fact that elucidating the mechanisms of cardiac vulnerability to electric shocks is crucial to understanding why defibrillation shocks fail, important aspects of cardiac vulnerability remain unknown. This research utilizes a novel anatomically based bidomain finite-element model of the rabbit ventricles to investigate the effect of shock polarity reversal on the reentrant activity induced by an external defibrillation-strength shock in the paced ventricles. The specific goal of the study is to examine how differences between left and right ventricular chamber anatomy result in differences in the types of reentrant circuits established by the shock. Truncated exponential monophasic shocks of duration 8 ms were delivered via two external electrodes at various timings. Vulnerability grids were constructed for shocks of reversed polarity (referred to as RV- or LV- when either the RV or the LV electrode is a cathode). Our results demonstrate that reversing electrode polarity from RV- to LV- changes the dominant type of post-shock reentry: it is figure-of-eight for RV- and quatrefoil for LV- shocks. Differences in secondary types of post-shock arrhythmia also occur following shock polarity reversal. These effects of polarity reversal are primarily due to the fact that the LV wall is thicker than the RV, resulting in a post-shock excitable gap that is predominantly within the LV wall for RV- shocks and in the septum for LV- shocks.  相似文献   
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The morphology and anatomy of fruits ofCoccocypselum condalia, C. geophiloides andLipostoma capitatum are discussed and illustrated. Except for the presence of a thin layer of sclerenchymatic endocarp inLipostoma, there are no significant differences in the anatomical structure of these fruits. Therefore,Lipostoma is placed under the synonymy ofCoccocypselum and the new combinationCoccocypselum capitatum is provided. The remaining species,Lipostoma sericeum, is of uncertain status.  相似文献   
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Past researchers have often considered neighbors to be beneficial to territorial residents, particularly compared with non‐neighbor conspecific competitors. However, neighbors have the potential to be costly to residents in terms of both defensive costs and lost resources. In this study, we assessed the relative costs of defending a mating territory against neighbors and non‐neighbors for the dragonfly Perithemis tenera, comparing across males with different numbers of contiguous neighbors; we also examined the possibility that the presence of contiguous neighbors might reduce the detection of potential mates. When neighbors were present, residents experienced a greater total number of intrusions by males; this increase in intrusions was due to higher numbers of intrusions by neighbors, as the number of intrusions by non‐neighbor males did not differ. Residents with immediately adjacent neighbors also made more sorties toward neighbors than did residents whose nearest neighbors’ territories were not immediately adjacent. Interestingly, although the number of visits by females did not vary with the presence of neighbors, residents with neighbors made fewer sorties toward females than did residents without neighbors. Our results suggest that defensive costs increased when neighbors were present, that residents with neighbors may have missed opportunities to acquire mates, and thus that living with neighbors can be costly in this species.  相似文献   
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