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101.
河南省5个地点中华蜜蜂的初步调查 总被引:1,自引:0,他引:1
为了摸清河南省的中华蜜蜂资源,了解其生物学特性,进一步为地方良种的选育和养蜂生产提供科学依据,我们于2004年7~9月先后在遂平、南湾、汝阳、孟津、商城等地区不同海拔的5个点采集了中蜂标本,主要从自然巢房及半人工饲养的巢房(如墙洞蜂巢和活框蜂箱)内采集。由于河南省内的中华蜜蜂很少转地饲养,所以采集的蜜蜂基本上是长期生活在当地环境的中华蜜蜂。每群采50只工蜂放入75%乙醇杀死,第二天更换一次乙醇浸泡保存。现将调查的初步结果分述如下:1 自然环境河南省地处中原,位于北纬31°23'~36°22',东经110°21'~116°39'[1];属于大陆型… 相似文献
102.
- 1. Digital hydrographic data are commonly employed in research, planning, and monitoring for freshwater conservation, but hydrographic datasets differ in spatial resolution and accuracy of spatial representation, possibly leading to inaccurate conclusions or unsuitable policies for streams and streamside areas.
- 2. To examine and illustrate the potential for different hydrographic datasets to influence in‐channel and streamside characterizations, a study area in the US Pacific Northwest was chosen because 1:100 000, 1:24 000, and densified 1:24 000 hydrography are available and widely used in research and management for several species of Pacific salmon and trout at risk. The potential was examined for differences among the digital hydrographic datasets in: (1) spatial extent to influence estimated abundances of fish habitat, streamside buffer conditions, and fish distributions; and (2) spatial position to influence estimated streamside buffer conditions and estimated stream gradient.
- 3. The analysis of spatial extent found the total stream length represented by the 1:100 000 hydrography was approximately one half that of 1:24 000 hydrography and only one fifth that of densified 1:24 000 hydrography. The 1:100 000 and 1:24 000 networks differed significantly for 13 out of 18 fish habitat attributes, and the three hydrographic datasets differed significantly for many characteristics in streamside buffers; fish distributions mapped at 1:24 000 added 6–14% of stream length to 1:100 000 distributions. The analysis of spatial position found few differences between the 1:100 000 and 1:24 000 hydrography in streamside buffer characteristics but significant differences in channel gradient.
- 4. Overall, hydrographic datasets differed only slightly in spatial position but differed in spatial extent to the point of representing different populations of streams. If species inhabiting larger streams (greater mean annual discharge) are of interest, then results derived from studies based on 1:100 000 hydrography should prove useful. However, higher‐resolution hydrography can be critical when designing and implementing strategies to protect fish and other aquatic species at risk in smaller streams.
103.
Managing fisheries presents trade‐offs between objectives, for example yields, profits, minimizing ecosystem impact, that have to be weighed against one another. These trade‐offs are compounded by interacting species and fisheries at the ecosystem level. Weighing objectives becomes increasingly challenging when managers have to consider opposing objectives from different stakeholders. An alternative to weighing incomparable and conflicting objectives is to focus on win–wins until Pareto efficiency is achieved: a state from which it is impossible to improve with respect to any objective without regressing at least one other. We investigate the ecosystem‐level efficiency of fisheries in five large marine ecosystems (LMEs) with respect to yield and an aggregate measure of ecosystem impact using a novel calibration of size‐based ecosystem models. We estimate that fishing patterns in three LMEs (North Sea, Barents Sea and Benguela Current) are nearly efficient with respect to long‐term yield and ecosystem impact and that efficiency has improved over the last 30 years. In two LMEs (Baltic Sea and North East US Continental Shelf), fishing is inefficient and win–wins remain available. We additionally examine the efficiency of North Sea and Baltic Sea fisheries with respect to economic rent and ecosystem impact, finding both to be inefficient but steadily improving. Our results suggest the following: (i) a broad and encouraging trend towards ecosystem‐level efficiency of fisheries; (ii) that ecosystem‐scale win–wins, especially with respect to conservation and profits, may still be common; and (iii) single‐species assessment approaches may overestimate the availability of win–wins by failing to account for trade‐offs across interacting species. 相似文献
104.
Increase in salinity of inland water sources is adversely affecting aquatic and terrestrial ecosystems around the world including
Australia. Inland saline water (ISW) with similar ionic profile to ocean water has potential for culturing marine species.
Gracilaria species are commercially important as they are a source of agar. One of the native species Gracilaria
cliftonii has been reported for high agar yield of 52%dw. The aim of this research was to investigate the feasibility of culturing
G. cliftonii in different ionic profiles of ISW under laboratory conditions. The growth rate of G. cliftonii under different ionic profiles ranged from 0.9 to 2.5 %day−1. Gracilaria cliftonii carbohydrate content decreased while protein content increased in culture conditions when compared to natural populations.
Agar yield, gel strength and melting point decreased while gelling temperature and sulphate content increased in culture conditions
when compared to natural populations. Strong correlation (R
2 > 0.8, P < 0.05) was observed between K+, Na+, Ca2+, and Mg2+ content in tissue and water indicating ionic regulation by G. cliftonii. This research provides basic information and presents supportive arguments for G. cliftonii as a potential species for inland saline water aquaculture. 相似文献
105.
106.
Jun Iguchi Yumiko Yamashita Ken Touhata Takeshi Yabu Michiaki Yamashita 《Fisheries Science》2013,79(3):531-536
Trace elemental composition in intermuscular bones of grilled eel fillets was analyzed to discriminate the geographic origin of eel products derived from Japan, China, and Taiwan. The intermuscular bones were decomposed with nitric acid-hydrogen peroxide, and twelve elements (Li, Ti, V, Mn, Ni, Co, Zn, Rb, Sr, Ba, Pb, and U) were analyzed by inductively coupled plasma mass spectrometry. Trace elemental composition including six elements: V, Co, Sr, Ba, Pb, and U, in intermusucular bones were significantly different between Japanese domestic eels and imported eels from China and Taiwan. The average content of lead in Japanese eels was 1/4 to 1/6 that in eels imported from China and Taiwan. The data of elemental content in intermuscular bones were used for linear discriminant analysis, and two discriminant models were constructed. In the Japan–China discriminant model, the discriminant probabilities between Japanese origin and Chinese origin were 82.5 and 93.3 %, respectively. In the Japan–Taiwan discriminant model, the discriminant probabilities between Japanese origin and Taiwanese origin were 87.5 and 87.0 %, respectively. Therefore, trace elemental analysis is effective for country-of-origin identification of eels processed as grilled eel fillets. 相似文献
107.
Mosavari N Feizabadi MM Jamshidian M Shahpouri MR Forbes KJ Pajoohi RA Keshavarz R Taheri MM Tadayon K 《Veterinary microbiology》2011,151(1-2):148-152
Restriction fragment length polymorphism (RFLP) genotyping was employed to analyze the population genetics of Mycobacterium bovis in Iran. One hundred and twenty-three isolates collected from slaughtered tuberculosis-suspect cattle and one clinically asymptomatic buffalo were subjected to RFLP analysis with probes of the polymorphic GC-rich sequence (PGRS) and the direct repeat sequence (DR) using DNA digested with PvuII and AluI. All these methods detected a large homogeneous population in which only a few isolates had variant genotypes. Only AluI-based RFLPs of both the PGRS and DR sequences were able to clearly differentiate between BCG and field strains of M. bovis. As in previous reports, these findings seem to reflect a recent dispersal of one or a few strains in Iran following the substantial expansion of Holstein-Friesian cattle over the last few decades. 相似文献
108.
Sanchez J Dohoo I Nødtvedt A Keefe G Markham F Leslie K DesCôteaux L Campbell J 《Veterinary parasitology》2002,107(3):209-226
The general objective of this study was to evaluate a crude Ostertagia ostertagi antigen enzyme-linked immunosorbent assay (ELISA) for monitoring gastrointestinal parasites in lactating dairy cattle. A longitudinal study of gastrointestinal parasites in lactating dairy cows was carried out in 38 herds in four provinces of Canada (Prince Edward Island, Quebec, Ontario and Saskatchewan) from September 1999 to October 2000. Bulk tank milk, cow milk, serum and fecal samples were collected monthly or quarterly from all these farms. Information on herd management factors was collected by a standard questionnaire and individual cow production data were obtained from an electronic database. The overall mean optical density ratio (ODR) was 0.30 and ranged from -0.05 to 1.55. Although a clear seasonal pattern was not observed, the ODR values tended to decrease during the housing period and start increasing in the spring before the cows went out to pasture. The second and third or greater lactation cows had significantly higher ODR values compared with first lactation animals. The individual cow ODR had a very low correlation with individual squared root fecal egg counts but showed a reasonably high correlation when herd averages values were computed (r=0.73). A moderate correlation (r approximately 0.50) between the bulk tank and herd average ODR was observed. Milk yield was negatively associated with individual cow milk ODR and a quadratic effect on ODR was observed for days in milk. Twenty-eight of the herds participated in a clinical trial of eprinomectin (Ivomec Eprinex) treatment at calving. The cow level ODR values determined late in the previous lactation had a marginally significant effect (P=0.07) on treatment response, suggesting that high OD cows responded better to the anthelmintic treatment. However, because of the small sample size available in this model, more research is needed to better understand this relationship. In conclusion, the indirect ELISA using an O. ostertagi crude antigen appears useful as a technique for monitoring gastrointestinal parasite burdens in adult dairy cows and holds promise as a potential predictor of response to anthelmintic treatment. 相似文献
109.
中国蜜蜂资源及自然地理区划研究 总被引:3,自引:0,他引:3
系统地论述了中国蜜蜂资源的种类、分布、区系的组成, 区系特征和自然地理区划等方面的内容, 为进一步开发利用蜜蜂资源提供科学依据. 相似文献
110.
从云南水富县太平乡(4群)和贵州六盘水市盘县(3群)共采集了7群东方蜜蜂Apis cerana样本,每群测定分析15只工蜂,每只工蜂总共有38个测定的形态特征。测定的性状特征数据进行主成分分析,聚类分析和因素分析,并与云南省内其它县东方蜜蜂A.cerana的相关数据进行比较。结果发现,水富东方蜜蜂A.cerana个体较大,体色较浅,贵州六盘水东方蜜蜂A.cerana个体较小, 体色较浅,与云南省内南部东方蜜蜂A.cerana分开,与德钦东方蜜蜂A.cerana形成一个类群。 相似文献