Acute Toxicity of Synthetic Pyrethroid Cypermethrin on the Common Carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.) Embryos and Larvae     

Rahmi?Ayd?nEmail author  Kenan?K?prücü  Mustafa?D?rücü  Sibel??im?ek?K?prücü  Murat?Pala 《Aquaculture International》2005,13(5):451-458

In this study, the toxic effects on the embryos and larvae of the common carp were used as a model to investigate the synthetic pyrethroid pesticide, cypermethrin, which contaminates aquatic ecosystems. Data obtained from the cypermethrin acute toxicity tests were evaluated using the Probit Analysis Statistical Method. The control and eight test experiments were repeated five times. The number of dead embryos significantly increased in response to cypermethrin concentrations 0.0001, 0.001, 0.01, 0.1, 1, 2, 4 and 8 μg l⁻¹ (p<0.05 for each case). The 48 h LC₅₀ value (with 95% confidence limits) of cypermethrin for common carp embryos was estimated at 0.909 (0.256–5.074) μg l⁻¹. Dose–response decreases in hatching success were recorded as 87.4, 85.0, 80.2, 71.4, 56.3, 48.6, 38.8 and 23.5%, respectively. The lowest concentration of cypermethrin (0.0001 μg l⁻¹) produced a significant increase in the number of dead larvae compared to the control group (p<0.05). The number of dead larvae significantly increased with increasing cypermethrin concentrations exposed for 1–96 h (p<0.05). The highest concentration (8 μg l⁻¹) showed the highest larvae mortality. The 96 h LC₅₀ value (with 95% confidence limits) of cypermethrin for common carp larvae was estimated at 0.809 (0.530–1.308) μg l⁻¹. The results of the study suggest that low levels of cypermethrin in the aquatic environment may have a significant effect on the reproduction and development of carp.  相似文献   

The effect of cypermethrin on some haematological parameters of Cyprinus carpio     

Mustafa Dörücü  Asiye Girgin 《Aquaculture International》2001,9(2):183-187

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Evaluation of VI-alpha and PIT-tagging of the seahorse <Emphasis Type="Italic">Hippocampus abdominalis</Emphasis>     

Chris?M.?C.?WoodsEmail author 《Aquaculture International》2005,13(3):175-186

The suitability of visible implant alphanumeric (VI-alpha) and passive integrated transponder (PIT)-tagging to individually identify seahorses (Hippocampus abdominalis) was assessed in two trials. For each trial, 24 seahorses were tagged and mortality, growth, tag retention and tag visibility/readability assessed, together with 24 control seahorses, over a period of 3 months. For VI-alpha tagging, a single tag was inserted under the skin between the first two anterior lateral tail rings of the seahorses. There was no difference in final seahorse length, wet weight, or mean SGR in tagged seahorses, compared with control seahorses, after 3 months. Tag retention was 100%, as was survival, in both treatments. Tag detection with the naked eye was generally poor but improved using LED blue light. However, readability of tag codes was highly variable and insufficiently reliable for VI-alpha to be suitable for identification of individual seahorses. In PIT-tagged seahorses, a single FDX-B transponder was inserted into the abdominal cavity of seahorses. There was also no difference in final seahorse length, wet weight, or mean SGR, compared with control seahorses, after 3 months. Tag retention was also 100%, as was survival in both treatments. Readability of transponders was reliable and quick using a compact reader. PIT-tagging is considered suitable for individual identification of large H. abdominalis.  相似文献   

Characterization of molecular variants of GnRH, induction of spermiation and sex reversal using salmon GnRH-A and domperidone in the protogynous diandric fish, Synbranchus marmoratus Bloch, (Teleostei, Synbranchidae)     

M.A. Ravaglia  F.L. Lo Nostro  M.C. Maggese  G.A. Guerrero  G.M. Somoza 《Fish physiology and biochemistry》1997,16(5):425-436

This paper studies the molecular variants of gonadotropin-releasing hormone (GnRH) present in the brain of the protogynous swamp eel, Synbranchus marmoratus, and the effects of the administration of salmon GnRH analogue (sGnRH-A) and the dopamine receptor antagonist, domperidone (DOM) on final maturation and gamete release in this species. Evidence for the presence of two GnRH variants, sGnRH and cIIGnRH were obtained by reverse phase high-pressure liquid chromatography (RP-HPLC) and radioimmunoassay with different antisera. The effects of treatment with sGnRH-A+DOM were checked by three ways: oocyte and milt release by stripping, histological analysis of the gonadal tissue, and androgen serum levels at different times throughout the experiment. In males, spermiation was induced after three weeks of treatment. In the female group, sGnRH-A+DOM did not induce ovulation at the end of the experiment. Histological analysis of the gonads from the female group showed evidence of sex reversal. All the treated fish had elevated androgen serum levels from the third week, with respect to control fish. In all cases, serum estradiol levels were undetectable. These results suggest that treatment with sGnRH analog and DOM induce sex reversal in female and spermiation in males. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Antibody response of glass eels,Anguilla japonica Temminck & Schlegel, to Pleistophora anguillarum Hoshina (Microspora) infection     

H-W Hung  C-F Lo  C-C Tseng  & G-H Kou 《Journal of fish diseases》1997,20(3):237-239

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Integration of independent component analysis with near infrared spectroscopy for evaluation of rice freshness   总被引：1，自引：0，他引：1  

Yung-Kun Chuang  Yi-Ping Hu  I-Chang Yang  Stephen R. Delwiche  Yangming Martin Lo  Chao-Yin Tsai  Suming Chen 《Journal of Cereal Science》2014

The storage time and conditions of rice has an enormous effect on its appearance, flavor, and quality of the nutrients; and the acidity of rice usually increases with prolonged storage. Therefore, evaluation of freshness is an important issue for rice quality. In this study, the NIR (near infrared) spectra combined with independent component analysis (ICA) technique was used to evaluate the rice freshness. A total of 180 white rice samples were collected from 6 crop seasons for the purpose of developing an ICA-NIR based procedure for rice freshness as quantified by pH values. Values of pH were determined by a BTB-MR (bromothymol blue – methyl red) method. The best calibration model of white rice was developed using the smoothed first derivative spectra, five ICs and cross-validation; the results indicated that r² (coefficient of determination) = 0.924, and in units of pH, SEC (standard error of calibration) = 0.145, SEP (standard error of prediction) = 0.146, bias = 0.001, and RPD (residual predictive deviation) = 3.65. Freshness of white rice could be distinguished either visually by a 3-dimensional diagram composed from ICs 2, 3 and 4, or statistically by a calibration model. The results show that ICA with NIR has the potential to be adopted as an effective method for evaluating rice freshness.  相似文献   

Pharmacokinetic studies of ivermectin: effects of formulation     

P K Lo  D W Fink  J B Williams  J Blodinger 《Veterinary research communications》1985,9(4):251-268

Studies are reported which describe the effects of formulation, animal species, and route of administration on the pharmacokinetics of ivermectin. Biological half-life t1/2 increases in the order: swine (0.5 day) less than dogs (1.8 day) less than cattle approximately equal to sheep (2.8 day). Formulation modifications, based upon the solubility properties of the drug, have been directed towards the development of a nonaqueous injectable formulation for cattle and an aqueous vehicle for horses. Bioavailability following subcutaneous injection in cattle can be regulated by control of injection solvent composition: a vehicle composed of a mixed aqueous-organic solvent exhibits pharmacokinetic properties (i.e., Cp, t1/2, AUC, and F) intermediate between those furnished by an aqueous formulation and via a purely nonaqueous solvent. The longer apparent biological half-life from this latter vehicle (t1/2 = 8.3 days) confirms that a slow absorption process dominates the pharmacokinetics in the nonaqueous injectable product to produce an effective controlled-release formulation. These bioavailability results illustrate the increase in the concentration of an organic solvent and a concomitant decrease in surfactant concentration in a micellar aqueous system for prolonged drug delivery via injection.  相似文献   

Die Bringung als wirtschaftlicher faktor in der forsteinrichtung     

Forstrat h. c. Dr. Hans Wodera 《European Journal of Forest Research》1936,58(10):339-348

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Immigrants Doing Business in a Mid‐sized Canadian City: Challenges,Opportunities, and Local Strategies in Kelowna,British Columbia          下载免费PDF全文

Lucia Lo  Carlos Teixeira 《Growth and change》2015,46(4):631-653

Lacking a tradition of settling immigrants and the appropriate infrastructure to integrate them, small‐ and medium‐sized cities often face the challenge of attracting and retaining immigrants. Using a mixed methods approach, this study compares the experiences of immigrant and non‐immigrant entrepreneurs in a mid‐sized Canadian city, Kelowna, British Columbia. A survey reveals different experiences between these two groups, with immigrants facing more challenges. In the absence of institutionally complete communities or strong ethnic economies, immigrants do not rely extensively on their own community resources, an element considered instrumental for immigrant business development in large cities. Compared to non‐immigrants, immigrant entrepreneurs have a more optimistic outlook on doing business in Kelowna; this is encouraging for a city trying hard to attract immigrant investment. Key informants recommended transforming the city into a more welcoming community, establishing appropriate support infrastructure, and removing potential institutional offsets. This paper adds new theoretical insights to the literature on immigrant entrepreneurship; all socio‐cultural, political‐institutional, and economic‐structural considerations are embedded in geography. The findings also have implications for growth strategies in small‐ and medium‐sized cities.  相似文献   

Molecular genetic and chemical assessment of radix Angelica (Danggui) in China   总被引：5，自引：0，他引：5  

Zhao KJ  Dong TT  Tu PF  Song ZH  Lo CK  Tsim KW 《Journal of agricultural and food chemistry》2003,51(9):2576-2583

The roots of Angelica sinensis (Danggui), a traditional Chinese medicine, have been used for invigorating blood circulation for over 2000 years in China. Three common species of Angelica roots are found in Asia: A. sinensis from China, A. acutiloba from Japan, and A. gigas from Korea. By using a molecular genetic approach, the 5S-rRNA spacer domains of the three species of Angelica were amplified, and their nucleotide sequences were determined. Diversity in DNA sequences among various species was found in their 5S-rRNA spacer domains, which could serve as markers for authentic identification of Angelica roots. In chemical analyses, the main constituents of Angelica roots including ferulic acid and Z-ligustilide were determined by HPLC; roots of A. sinensis were clearly distinct in that they contained approximately 10-fold higher levels of ferulic acid and Z-ligustilide as compared to roots of A. acutiloba and A. gigas. In addition, the amounts of main constituents in roots of A. sinensis varied according to different regions of cultivation and different methods of preservation. The chemical profile determined by HPLC therefore could serve as a fingerprint for quality control of Angelica roots.  相似文献