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91.
92.
Journal of Plant Diseases and Protection - Echinochloa crus-galli (L.) Pal. Beauv. is one of the most noxious weeds in maize cultivation and has evolved target-site resistance to ALS-inhibiting...  相似文献   
93.
AIMS: To assess the feasibility of applying animal-based welfare assessments developed for use in Europe on New Zealand dairy farms; in particular, to identify measures which could be evaluated during a single visit at milking time alongside whole herd locomotion scoring.

METHODS: A protocol for animal welfare assessment, developed in the United Kingdom (UK), was evaluated. Measures that were suitable for use on pasture-based dairy farms in New Zealand were then assessed for practicability on 59 farms across New Zealand, during and immediately after milking, alongside whole herd locomotion scoring. Where data were collected the results were compared to those from a UK study of 53 dairy farms.

RESULTS: Thirteen observations of the physical condition of cows were considered suitable for measurement, excluding observations related to hock lesions as they are rarely observed on pasture-based farms. Five of these measures were not assessed as there was not time to do so during milking alongside whole herd locomotion scoring. Thus, the prevalence of dirty flanks, hind limbs and udders, dull coat, thick hairy coat, significant hair loss, very fat cows (body condition score (BCS) ≥7 on 1–10 scale) and very thin cows (BCS≤3), were recorded. Three measures of behaviour were considered suitable for measurement on-farm, but only locomotion score was practicable and was measured. Farmer-estimates for the incidence of mastitis, lameness, sudden death, milk fever and other diseases were also obtained.Overall, dirty flanks, dirty udders and estimated milk fever incidence were more prevalent in this study than in the UK. The prevalence of thin and fat cows, lame cows and estimated mastitis incidence were much lower in the present study than on UK farms.

CONCLUSIONS AND CLINICAL RELEVANCE: Animal-based assessments can be used on dairy farms in New Zealand, but need to be modified from those developed for housed cows.Welfare on these farms was generally good compared to those in the UK, but these results need to be confirmed on more farms using a wider range of assessments than proved practicable in this study.  相似文献   

94.
ABSTRACT The use of partially resistant cultivars should become an essential component of a sustainable management strategy of potato late blight, caused by Phytophthora infestans. It is therefore important to determine to what extent P. infestans populations can be selected for increased aggressiveness by potato cultivars with different levels of partial resistance. To this end, we sampled P. infestans populations from France and Morocco, chosen as locations where late blight occurs regularly but which differ in the distribution of potato cultivars. Cross-inoculation experiments were used to determine the aggressiveness of all populations to potato cvs. Bintje (prevalent in France but not grown in Morocco) and Désirée (popular in Morocco but cultivated to a very small extent in France). French populations were more aggressive on cv. Bintje than on cv. Désirée, irrespective of the site they were sampled from. Their aggressiveness increased between early and late samplings, suggesting that both cultivars selected for increased aggressiveness during epidemics. By contrast, Moroccan populations were more aggressive on Désirée, regarded as partially resistant in Europe, than on Bintje, highly susceptible under European conditions. These data indicate that P. infestans populations adapt to locally dominant cultivars, irrespective of their resistance levels, and can therefore overcome polygenic, partial resistance. This adaptive pattern may render partial resistance nondurable if not properly managed.  相似文献   
95.
96.
Inferior parietal lobule (IPL) neurons were studied when monkeys performed motor acts embedded in different actions and when they observed similar acts done by an experimenter. Most motor IPL neurons coding a specific act (e.g., grasping) showed markedly different activations when this act was part of different actions (e.g., for eating or for placing). Many motor IPL neurons also discharged during the observation of acts done by others. Most responded differentially when the same observed act was embedded in a specific action. These neurons fired during the observation of an act, before the beginning of the subsequent acts specifying the action. Thus, these neurons not only code the observed motor act but also allow the observer to understand the agent's intentions.  相似文献   
97.
Data availability, and unreported and unregulated fishing are significant obstacles to evaluating stock status, especially in tropical areas. Limitations in data quantity and quality can lead to model misspecification and erroneous data treatments, potentially causing important changes in model outputs and subsequent management implications. Red snapper Lutjanus purpureus (Poey) in French Guiana provides an example of a stock with a long-time series of fishery-dependent data subject to large uncertainty. A flexible catch-at-age model (Stock Synthesis) was applied to the available data and compared to an historically applied assessment approach. Inter-model variability based on different model specifications and data treatments were compared to identify better the status of the resource. Results showed that a major source of uncertainty in the model was the inclusion of a catch-per-unit-effort abundance index with questionable ability to track abundance. The Stock Synthesis model provided a more flexible and viable method than the virtual population analysis approach. Despite large uncertainty, models depicted a similar trend with a notable stock depletion in the late 1990s but with two distinct biomass trends in more recent years depending on the treatment. To reduce uncertainty and preserve this important economic resource, new data collection programmes and management policies are needed.  相似文献   
98.
99.
Bremia lactucae is one of the most devastating and widespread pathogens in lettuce production worldwide. Despite its economical importance, uncertainty prevails about the species delimitation in the genus Bremia. Commonly, Bremia is considered to be monotypic, containing only Bremia lactucae, while taxonomists have described additional species, and molecular phylogenetic studies have shown significant sequence divergence between accessions from different hosts. Here, we report that several previously described species are genetically highly distinct from Bremia lactucae parasitic to Lactuca sativa. These include Bremia lapsanae, Bremia sonchicola, and Bremia taraxaci. In addition to these host-specific species, a plurivorous species is revealed, which infects hosts from three different tribes in the Asteraceae subfamilies Asteroideae and Carduoideae. The broad host range of clade 1 is exceptional for downy mildews and only paralleled by Pseudoperonospora cubensis, which infects a broad range of Cucurbitaceae. The taxonomic status of Bremia cirsii and of Bremia centaureae remains unresolved, as the accessions from Cirsium and Centaurea, respectively, did not form a monophylum but were partly contained in the plurivorous clade 1. Bremia lactucae was found to be restricted to Lactuca sativa and Lactuca serriola. Thus, it can be assumed that Bremia infections on weeds apart from Lactuca species do not pose a significant risk for lettuce production. However, it is unlikely that breeding resistance genes from Lactuca serriola into Lactuca sativa will result in durable resistance of lettuce to downy mildew disease, because the current study provides additional evidence that Bremia accessions from both hosts form a population continuum.  相似文献   
100.
We investigated the effect of distinct genotypes on growth performance, DM and N digestibilities, serum metabolite and hormonal profiles, and carcass and meat quality of pigs. Eight control-line and eight select-line pigs with an equal number of gilts and castrated males per genotype were chosen from the group of pigs subjected to selection for lean growth efficiency. Pigs were housed individually and allowed ad libitum access to common grower, finisher 1, and finisher 2 diets when they reached approximately 20, 50, and 80 kg, respectively, and water throughout the study. Although genotype had no effect on growth performance during the finisher 2 phase and overall, select-line pigs grew faster and more efficiently (P < 0.05) during the grower and finisher 1 phases than did control-line pigs. Dry matter and N digestibilities during the grower phase were lower (P < 0.05) in select-line pigs compared with control-line pigs. Select-line pigs had less ultrasound backfat (P < 0.05) at the end of the grower and finisher 2 phases. Serum urea N (P < 0.05) and leptin concentrations were lower in select-line pigs than in control-line pigs, but the effect of genotype on serum glucose, triglyceride, or insulin concentration was rather inconsistent. Select-line pigs had heavier heart (P < 0.05), liver (P = 0.08), and kidneys (P < 0.01), implying a higher metabolic activity. Less 10th-rib carcass backfat (P < 0.01) and a trend for larger carcass longissimus muscle area (P = 0.10) were reflected in the greater (P < 0.01) rate and efficiency of lean accretion in select-line pigs. Select-line pigs had lower subjective meat color (P < 0.01), marbling (P < 0.05), and firmness (P < 0.01) scores. Final serum leptin concentration was correlated positively with carcass backfat thickness (r = 0.73; P < 0.01) and negatively with overall feed intake (r = -0.77; P < 0.01). These results indicate that pigs with distinct genotypes exhibited differences in the growth rate, metabolite and hormonal profiles, and body composition. Further research is necessary to determine whether pigs with distinct genotypes respond differently to dietary manipulations, which would have an effect on developing optimal feeding strategies for efficient and sustainable pig production.  相似文献   
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