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81.
Changing climate and fuel accumulation are increasing wildfire risks across the western United States. This has led to calls for fire management reform, including the systematic use of prescribed fire. Although use of prescribed fire by private landowners in the southern Great Plains has increased during the past 30 yr, studies have determined that liability concerns are a major reason why many landowners do not use or promote the use of prescribed fire. Generally, perceptions of prescribed fire ? related liability are based on concerns over legal repercussions for escaped fire. This paper reviews the history and current legal liability standards used in the United States for prescribed fire, it examines how perceived and acceptable risk decisions about engagement in prescribed burning and other activities differ, and it presents unanticipated outcomes in two cases of prescribed fire insurance aimed at promoting the use of prescribed fire. We demonstrate that the empirical risk of liability from escaped fires is minimal (< 1%) and that other underlying factors may be leading to landowners’ exaggerated concerns of risk of liability when applying prescribed fire. We conclude that providing liability insurance may not be the most effective approach for increasing the use of prescribed fire by private landowners. Clearly differentiating the risks of applying prescribed fire from those of catastrophic wildfire damages, changing state statutes to reduce legal liability for escaped fire, and expanding landowner membership in prescribed burn associations may be more effective alternatives for attaining this goal. Fear of liability is a major deterrent to the use of prescribed fire; however, an evaluation of the risks from escaped fire does not support perceptions that using prescribed fire as a land management tool is risky. Prescribed burning associations and agencies that support land management improvement have an important role to play in spreading this message.  相似文献   
82.
We studied the influence of surveyed area size on density estimates by means of camera‐trapping in a low‐density felid population (1–2 individuals/100 km2). We applied non‐spatial capture–recapture (CR) and spatial CR (SCR) models for Eurasian lynx during winter 2005/2006 in the northwestern Swiss Alps by sampling an area divided into 5 nested plots ranging from 65 to 760 km2. CR model density estimates (95% CI) for models M0 and Mh decreased from 2.61 (1.55–3.68) and 3.6 (1.62–5.57) independent lynx/100 km2, respectively, in the smallest to 1.20 (1.04–1.35) and 1.26 (0.89–1.63) independent lynx/100 km2, respectively, in the largest area surveyed. SCR model density estimates also decreased with increasing sampling area but not significantly. High individual range overlaps in relatively small areas (the edge effect) is the most plausible reason for this positive bias in the CR models. Our results confirm that SCR models are much more robust to changes in trap array size than CR models, thus avoiding overestimation of density in smaller areas. However, when a study is concerned with monitoring population changes, large spatial efforts (area surveyed ≥760 km2) are required to obtain reliable and precise density estimates with these population densities and recapture rates.  相似文献   
83.
禾谷缢管蚜在越冬寄主植物上的行为研究   总被引:1,自引:0,他引:1  
通过室内饲养观察、田间调查和利用微型昆虫显微摄影技术,研究了禾谷缢管蚜越冬卵在越冬寄主稠李(Prunus padis)上孵化,干母、干雌取食、生长发育和繁殖等行为过程,以及形态和体色变异特点。结果表明,禾谷缢管蚜越冬卵在室内的孵化率为88.68%-92.51%;在德国北部吕贝克附近田间孵化率为24.2%。越冬卵孵化起点温度低于4℃。在室温22℃下卵孵化历期为5-7d,孵化高峰在卵孵化始期后第3-4天。一日内最佳孵化时间在05:00-07:30。在室内饲养条件下,将越冬卵孵化的干母直接移植到麦苗上,蚜虫几乎都不能存活。  相似文献   
84.
85.
OBJECTIVE: To identify the prevalence of DNA of Mycoplasma haemofelis; 'Candidatus Mycoplasma haemominutum'; Anaplasma phagocytophilum; and species of Bartonella, Neorickettsia, and Ehrlichia in blood of cats used as blood donors in the United States. DESIGN: Prospective study. ANIMALS: 146 cats that were active blood donors. PROCEDURES: Environmental history was requested for each blood-donor cat from which a blood sample (mixed with EDTA) was available. Polymerase chain reaction assays capable of amplifying the DNA of the microorganisms of interest following DNA extraction from blood were performed. RESULTS: Overall, DNA of one or more of the infectious agents was detected in blood samples from 16 of 146 (11%) feline blood donors. Twenty-eight laboratory-reared cats housed in a teaching hospital had negative results for DNA of all organisms investigated. The DNA of at least 1 infectious agent was amplified from blood samples collected from 16 of 118 (13.6%) community-source cats; assay results were positive for 'Candidatus M haemominutum,' M haemofelis, or Bartonella henselae alone or in various combinations. Of the community-source cats allowed outdoors (n = 61) or with known flea exposure (44), DNA for a hemoplasma or B henselae was detected in 21.3% and 22.7%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: When community-source cats, cats allowed outdoors, or cats exposed to fleas are to be used as blood donors, they should be regularly assessed for infection with M haemofelis, 'Candidatus M haemominutum,' and Bartonella spp, and flea-control treatment should be regularly provided.  相似文献   
86.
Severe adverse cutaneous reactions were documented in two dogs with acute skin lesions and systemic signs after exposure to several oral and injectable drugs. Because of the high morbidity and mortality rates of many severe cutaneous drug reactions and a poor response to supportive care, wound management, and conventional immunosuppressive therapy, human intravenous immunoglobulin (IVIG) was infused on 2 consecutive days (1 g/kg per day) after informed consent was received. Human IVIG, with supportive care, resulted in rapid resolution of dermatological and systemic signs in both dogs; this treatment may be considered in other cases of severe cutaneous drug reactions.  相似文献   
87.
Abstract: Two male castrated Whippet littermates were presented at 1 year of age for pallor, tachycardia, systolic heart murmur, dark yellow to orange feces, intermittent lethargy, pigmenturia, and muscle shivering or cramping after exercise. Persistent macrocytic hypochromic anemia with marked reticulocytosis and metarubricytosis was found when CBC results were compared with reference values for Whippets. Increased serum creatine kinase activity and hyperkalemia also were sometimes present over the 4‐year period of evaluation. Progressively increasing serum concentrations of N‐terminal prohormone brain natriuretic peptide suggested cardiac disease. Erythrocytes from the whippets were less osmotically fragile but more alkaline fragile than those from control dogs. Erythrocyte phosphofructokinase (PFK) activities and 2,3‐diphosphoglycerate concentrations were decreased. Restriction enzyme‐based DNA test screening and DNA sequencing revealed the same mutation in the muscle‐PFK gene of the Whippets as seen in English Springer Spaniel dogs with PFK deficiency. This is the first report of PFK deficiency in Whippet dogs. In addition to causing hemolysis and exertional myopathy, heart disease may be a prominent clinical component of PFK deficiency in this breed and has not been previously recognized in PFK‐deficient English Springer Spaniels.  相似文献   
88.
K. Vijayan    P. P. Srivatsava    C. V. Nair    A. K. Awasthi    A. Tikader    B. Sreenivasa    S. R. Urs 《Plant Breeding》2006,125(3):298-301
Mulberry (Morus indica L.) is an important tree crop being exploited for feeding the silk‐producing insect Bombyx mori L. In order to identify parents suitable for breeding to raise high‐yielding varieties for the non‐traditional areas of Kerala, India and also to identify markers associated with leaf yield attributing traits, the present study was undertaken with 44 mulberry genotypes. Variability on morpho‐biometric traits and molecular markers, generated with 12 selected ISSR primers, was estimated. Significant differences between genotypes were observed for all the traits. The dendrogram generated with morpho‐biometric characters clustered the genotypes into three distinct groups and one isolate, while the same using Inter simple sequence repeat (ISSR) markers clustered the genotypes into five groups and six isolates. The greater resolving power of the ISSR markers was evident form the dendrograms. Using step‐wise multiple regression analysis, a number of markers associated with number of branches, total shoot length, leaf weight, internodal distance, leaf chlorophyll, protein, leaf moisture percentage were identified. These markers could be of much use in Marker assisted selection (MAS) breeding programmes in mulberry, especially when no genetic information in terms of linkage maps and Quantitative Trait Locis (QTLs) is available a plant with high heterozygosity and a long juvenile period.  相似文献   
89.
As a consequence of the BSE crisis, alternatives for fertilizers derived from animal residues are being sought for use in organic horticulture. Grain legumes (milled seeds of pea, yellow lupine, and faba bean) and organic fertilizers of industrially processed plant and microbial residues (Maltaflor®‐spezial, Phytoperls®, Agrobiosol®, Rizi‐Korn) were investigated as to their suitability as a replacement fertilizer. With four soils, incubation studies were conducted to determine net N mineralization of the organic fertilizers, and pot experiments were used to measure the apparent N utilization by perennial ryegrass. The objectives of this study were (1) to determine simple fertilizer characteristics that describe their N release and (2) to compare the suitability of both experimental setups to predict fertilizer N release. At the end of all experiments, net N mineralization and apparent N utilization from Rizi‐Korn was highest compared to all the other organic fertilizers, while pea performed relatively poor. This differentiation between the fertilizers developed during the first 2 weeks. Nitrogen release from the organic fertilizers as described by net N mineralization or apparent N utilization was significantly related to the N content of the fertilizers. Different soils modified this relationship. Two industrially processed fertilizers (Phytoperls®, Agrobiosol®) could not be included into a generalized relationship because N release from these fertilizers was low compared to their N content. It is discussed that the quality of fertilizer C and N affected the N release from the fertilizers. Both experimental setups, incubation and pot experiments, were suitable to describe the release of plant‐available N from the organic fertilizers. However, N release of fertilizers with a low net N mineralization in the incubation experiments was underestimated compared to plant N uptake of ryegrass in the pot experiments. It is concluded that the N content of organic fertilizers indicates, but not predicts their N release.  相似文献   
90.
Crop management can be optimized and nitrogen (N) losses can be reduced with a better knowledge of soil‐nitrogen availability, especially if this information becomes directly available on‐site in a fast and cost‐effective way. In this paper, simple on‐farm methods to determine nitrate‐N in field‐moist soil samples immediately after sampling are described. The procedures include volumetric soil sampling, extraction based on manual shaking with tap water as universally available extractant, filtering soil/extractant mixtures on‐site, on‐site determination of the soil water content, and reflectometric nitrate measurements based on test strips. Using correction factors can compensate the impact of the temperature during the final nitrate measurement. An excellent agreement was found between the developed quick‐test procedures and the standard laboratory procedure. The proposed quick‐test has great potential to enable economical savings for farmers as well as benefiting the environment.  相似文献   
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