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61.
Blooms of the benthic toxic dinoflagellate genus Ostreopsis have been recorded more frequently during the last two decades, particularly in warm temperate areas such as the Mediterranean Sea. The proliferation of Ostreopsis species may cause deleterious effects on ecosystems and can impact human health through skin contact or aerosol inhalation. In the eastern Atlantic Ocean, the toxic O. cf. ovata has not yet been reported to the north of Portugal, and the only species present further north was O. cf. siamensis, for which the toxic risk is considered low. During summer blooms of unidentified Ostreopsis species on the French Basque coast (Atlantic) in 2020 and 2021, people suffered from irritations and respiratory disorders, and the number of analyzed cases reached 674 in 2021. In order to investigate the causes, sampling was carried out during summer 2021 to (i) taxonomically identify Ostreopsis species present using a molecular approach, (ii) isolate strains from the bloom and culture them, and (iii) characterize the presence of known toxins which may be involved. For the first time, this study reports the presence of both O. cf. siamensis and O. cf. ovata, for which the French Basque coast is a new upper distribution limit. Furthermore, the presence of ovatoxins a, b, c, and d in the environmental sample and in a cultivated strain in culture confirmed the toxic nature of the bloom and allowed identifying O. cf. ovata as the producer. The present data identify a new health risk in the area and highlight the extended distribution of some harmful dinoflagellates, presumably in relation to climate change.  相似文献   
62.
The contents of transition metal ions iron, copper, zinc, and manganese were simultaneously determined in pig feed using an ion chromatographic technique (IC) preceded by dry ashing. Employing ion exchange, the ions were separated on an IonPac CS5A column used in combination with a pyridine-2,6-dicarboxylic acid based eluent. The separation was followed by spectrophotometric detection after postcolumn reaction with 4-(2-pyridylazo)resorcinol. Dry ashing parameters were varied to assess their role in potential analyte loss. Quantitative recoveries (>95%) were obtained for all analytes with a dry ashing method that included a moderate temperature-time regime and ash leaching support in the form of sonication and heat treatment. The use of HCl as leaching acid and the presence of alkaline earths in the matrix solution did not interfere with the chromatographic separation.  相似文献   
63.
The contribution of dimethyl sulfide (DMS) to the aroma of Syrah and Grenache Noir wines from the Rhone Valley of France was investigated by sensory analysis, and its levels in these wines were measured. The potential DMS in the corresponding grapes and wines, susceptible to release during wine aging, was evaluated. Free DMS and potential DMS assessed by a heat-alkaline treatment were measured in grape juices and wines by SPME-GC-MS using methods previously reported and slightly modified. A relationship between potential DMS from grapes and the total DMS levels in wine was demonstrated. Furthermore, a linear regression between the ratio of free DMS levels to these total DMS levels in wine and time of storage was found. Free and potential DMS levels in grapes and wines depended on grape variety, vintage, and vine location. DMS imparted a noticeable and complex contribution to the aroma of the wines investigated, depending on the mode of sensory perception used, either before or after glass swirling. It significantly enhanced the fruity notes of the wines, and additional truffle and black olive notes.  相似文献   
64.
How successful are plant species reintroductions?   总被引:1,自引:0,他引:1  
Reintroduction of native species has become increasingly important in conservation worldwide for recovery of rare species and restoration purposes. However, few studies have reported the outcome of reintroduction efforts in plant species. Using data from the literature combined with a questionnaire survey, this paper analyses 249 plant species reintroductions worldwide by assessing the methods used and the results obtained from these reintroduction experiments. The objectives were: (1) to examine how successful plant species reintroductions have been so far in establishing or significantly augmenting viable, self-sustaining populations in nature; (2) to determine the conditions under which we might expect plant species reintroductions to be most successful; (3) to make the results of this survey available for future plant reintroduction trials. Results indicate that survival, flowering and fruiting rates of reintroduced plants are generally quite low (on average 52%, 19% and 16%, respectively). Furthermore, our results show a success rate decline in individual experiments with time. Survival rates reported in the literature are also much higher (78% on average) than those mentioned by survey participants (33% on average). We identified various parameters that positively influence plant reintroduction outcomes, e.g., working in protected sites, using seedlings, increasing the number of reintroduced individuals, mixing material from diverse populations, using transplants from stable source populations, site preparation or management effort and knowledge of the genetic variation of the target species. This study also revealed shortcomings of common experimental designs that greatly limit the interpretation of plant reintroduction studies: (1) insufficient monitoring following reintroduction (usually ceasing after 4 years); (2) inadequate documentation, which is especially acute for reintroductions that are regarded as failures; (3) lack of understanding of the underlying reasons for decline in existing plant populations; (4) overly optimistic evaluation of success based on short-term results; and (5) poorly defined success criteria for reintroduction projects. We therefore conclude that the value of plant reintroductions as a conservation tool could be improved by: (1) an increased focus on species biology; (2) using a higher number of transplants (preferring seedlings rather than seeds); (3) taking better account of seed production and recruitment when assessing the success of reintroductions; (4) a consistent long-term monitoring after reintroduction.  相似文献   
65.
Decisions on biodiversity management and conservation are increasingly based on indicators. These imply, explicitly or implicitly, a number of criteria such as nativeness, rarity, endangeredness and (economic) value. We investigated to which degree such criteria matter to members of the general public and conducted a survey in eight sites across Europe (n = 2378). We explored the relationships between perceived desirability of a species’ population increase and six species-related attributes, including previous population change, rarity, vulnerability, harmfulness, value, attractiveness, and nativeness.For all three species types investigated, previous population change, followed by perceived harmfulness and value, had the strongest relationship with desirability of future increase. Perceived nativeness played only a minor role in informing a species’ desirability. A strong relationship between previous change and desirability of future increase could also be found in a number of additional species and six different habitat types, suggesting that previous change is a key criterion that the general public draws on to inform their attitudes towards biodiversity management.We compare the roles of such criteria for the general public to those used in the scientific and political discourse, and draw conclusions for the use of indicators in the conservation debate, arguing that biodiversity management that is strongly focused on nativeness might fall short of the interests of the citizenship, whereas other criteria, such as population trends, harmfulness and role and value of a species in the ecosystem strongly resonate with the views of the general public.  相似文献   
66.
The root-knot nematode Meloidogyne incognita is a polyphagous pest distributed from temperate to tropical regions. However, the lack of suitable markers leads to a poor knowledge of its population genetic structure and colonization process. Here we describe the first characterization of 15 microsatellite loci from this nematode, that were developed from an enriched genomic library. Although the variability of these microsatellites was generally low, three of them exhibited a significant level of intrapopulation polymorphism, with three to seven alleles detected. The observed and expected heterozygosities ranged from 0.025 to 0.385 and from 0.024 to 0.779, respectively. Thus, these new microsatellite markers have potential value for the implementation of genotyping experiments in this nematode. Furthermore, successful cross-amplification of the variable microsatellite loci in seven other Meloidogyne species provides the opportunity of using these markers for population genetic studies in these damaging plant-parasitic nematodes.  相似文献   
67.
Nasal colonization by methicillin-resistant Staphylococcus aureus (MRSA) was evaluated after a mupirocin treatment in a family previously colonized by MRSA sequence type ST398 and ST1, who lived close to a pig farm. Eight nasal samples were swabbed from each of the four family members on different moments after mupirocin treatment. The efficacy of treatment was low in those family members who worked in the farm, and higher in the remaining two family members with sporadic contact with pigs. In addition, nasal and skin swabs from randomly selected pigs of the farm were taken. MRSA were detected in 33% of pigs tested. All MRSA isolates obtained were characterized by Staphylococcal-Cassette-Chromosome mec (SCCmec) determination, Multilocus-Sequence-Typing (MLST), spa- and agr-typing, Pulsed-field-gel-electrophoresis (PFGE), antimicrobial susceptibility, detection of antimicrobial resistance genes, and toxin gene profiling. Spa-types t011, t1255 and t1197 were detected in humans and animals, with indistinguishable PFGE patterns, suggesting animal to human MRSA transmission. Each spa-type was ascribed to a specific pulsotype. Spa-types t127 and t108 were only detected in MRSA isolates obtained from humans, and t012 only in those from animals. MRSA ST1-t127 isolates and some ST398-t011 and ST398-t1197 isolates presented a multiantimicrobial-resistance phenotype. None of them harbored lukF/lukS, tst, eta and etb virulence genes. This study showed that the efficacy of nasal MRSA decolonization in healthy people with very close contact with pigs is especially low.  相似文献   
68.
Contrast‐enhanced ultrasound may be helpful for detecting early renal microvascular damage and dysfunction in dogs. However, before this noninvasive imaging method can be tested as an early‐stage screening tool in clinical patients, an improved understanding of long‐term variation in healthy animals is needed. In this prospective, secondary, longitudinal, serial measurements study, variability of contrast‐enhanced ultrasound renal perfusion parameters was described for eight healthy dogs, using seven time points and a period of 83 weeks. Dogs were sedated with butorphanol (0.4 mg/kg), and contrast‐enhanced ultrasound of each kidney was performed after an intravenous bolus injection of a microbubble contrast agent (0.04 mL/kg). Time‐intensity curves were created from regions‐of‐interest drawn in the renal cortex and medulla. Intensity‐related parameters representing blood volume and time‐related parameters representing blood velocity were determined. A random‐effects model using restricted maximum likelihood was used to estimate variance components. Within‐dog coefficient of variation was defined as the ratio of the standard deviation over the mean. Time‐related parameters such as time‐to‐peak, rise and fall time had lowest within‐dog variability. Intensity‐related parameters such as peak enhancement, wash‐in and wash‐out area under the curve, total area under the curve, and wash‐in and washout rates had high within‐dog variability (coefficient of variation > 45%). Authors therefore recommend the use of time‐related parameters for future studies of renal perfusion. Within‐dog variability for bilateral kidney measurements was extremely low, therefore contrast‐enhanced ultrasound may be particularly useful for detecting unilateral changes in renal perfusion. Future studies are needed to compare contrast‐enhanced ultrasound findings in healthy dogs versus dogs with renal disease.  相似文献   
69.
Random amplified polymorphic DNA (RAPD) markers were used for assessing genetic diversity and its structure in a collection of the drought-tolerant, tropical multipurpose shrub legume Flemingia macrophylla (Willd.) Merrill. The species is especially suited to low-input smallholder production systems and is used as dry season forage supplement, live soil cover, mulch and living barrier, among others. Genetic groups identified by RAPD analysis related closely to four morphotypes revealed by multivariate analysis of morphological, agronomic and forage quality characteristics. Overall genetic diversity in the collection was moderate (H T = 0.241), with 79% differentiation among and high genetic similarity (GS) within groups (0.672–0.965). Results indicate a closer relationship of the semi-erect morphotypes M3 and M4 with F. stricta rather than with the erect morphotype M1. The latter was genetically the most depauperate, followed by morphotypes M2 and M4. New evidence is provided that non-Asian accessions collected in Africa and South America are derived from introduced Southeast Asian material. Furthermore, RAPD data suggest the presence of duplicates in the collection, especially in the overrepresented erect morphotype M1.  相似文献   
70.
Using AFLPs, 71 peppers (Capsicum) accessions from the species C. chinense Jacq., C. baccatum L., C. annuum L. and C. frutescens L. from indigenous communities of the Amazon Department (Colombia) were studied to assess the genetic diversity of the collections, and delineate species gene groups. Ten additional accessions were included as a reference species group. Three clusters were identified in the Amazonian accessions by Multiple Correspondence Analyses (MCA) and a dendrogram from the UPGMA analyses of Nei – Li genetic similarity. The clusters correspond to gene groups of the species Capsicum chinense (the majority of the accessions), C. baccatum and the complex annuum - frutescens. A fourth cluster corresponds to the reference accession C. pubescens. The MCA analyses accounted for 95% of the total variation. The total genetic variation was low (Ht 0.119) and a genetic diversity index (Gst) of 0.331 was obtained. This suggests a limited genetic diversity of the accessions and a close relatedness of the species. This study is the first molecular marker assessment of genetic diversity for peppers from the Colombian Amazon, and provides information of biodiversity that can be employed in the preservation and use of Capsicum germplasm.  相似文献   
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