Recruitment patterns of six species of cyprinid fishes in the lower River Trent, England   总被引：1，自引：0，他引：1  

A. D. Nunn  I. G. Cowx  J. P. Harvey 《Ecology of Freshwater Fish》2002,11(2):101-111

Abstract – Fisheries data were collected for six species of 0-group cyprinid fishes from eight sites in the lower reaches of the River Trent, England, between May and October 1999 inclusive, using a micromesh seine net. Recruitment and growth patterns were observed via monthly length–frequency histograms and estimations of mean length. In the cases of roach and dace, growth was approximately linear through the summer, before declining in September and October. In the cases of chub and gudgeon, and to a lesser extent bream and bleak, however, there were suggestions of multiple recruitment events. It is argued that some of the fish species examined in the present study adopt fractional or protracted spawning strategies in the lower River Trent.  相似文献   

Egg quality in rainbow trout: The relation between egg viability,selected aspects of egg composition,and time of stripping     

J.C.A. Craik  S.M. Harvey 《Aquaculture (Amsterdam, Netherlands)》1984,40(2):115-134

Batches of eggs (1 batch/female) from 17 rainbow trout in their first spawning season were stripped and reared separately, and the percentage which hatched and the percentage which reached the stage of first feeding were determined. The fertilised egg batches were analysed for egg wet weight, egg dry weight, chorion weight and levels in the eggs of free, bound and total lipid, precipitable protein, protein phosphorus, lipid phosphorus, calcium and iron. All determinations were made on single eggs, and six eggs from each batch were analysed for each variable. Results were expressed in absolute terms (as weight of component per egg) and as percentage of egg dry weight. Highly significant variations in all these aspects of egg composition were shown to occur between parent females. However, there was no significant correlation between the percentage of the original number of eggs which hatched and any one aspect of egg composition, except for a weak positive correlation (P<0.05) with the percentage of protein phosphorus in the eggs. Similarly, there was no significant correlation between the percentage of the original number of eggs which reached first feeding and any one aspect of egg composition except for weak positive correlations (P<0.05) with egg wet weight and with both the absolute level and the percentage of protein phosphorus in the egg. There was significant positive correlation (P<0.05) between the percentage of hatched eggs (alevins) surviving to first feeding and each of the following: egg wet weight, egg dry weight and absolute levels in the egg of bound lipid, precipitable protein and protein phosphorus. Egg batches with higher hatching percentage (>50%) differed significantly from those with zero hatching percentage in having (in absolute terms) higher egg weight, chorion weight, protein phosphorus (all P<0.001), egg dry weight, bound lipid and precipitable protein (all P<0.01) and (percentages) higher chorion weight (P<0.05) and protein phosphorus (P<0.001), and lower free and total lipid (both P<0.01) and iron (P<0.05). In a separate experiment to investigate the effects of allowing the eggs to be retained by the female within the abdominal cavity for increasing periods of time after ovulation, eggs were obtained from three females on three or four successive occasions 2–11 days apart. Although the above aspects of egg composition remained almost constant when the eggs were held in the female for up to 18 days after ovulation, the hatching percentage declined sharply within this period, in two females falling from over 90% to near zero. These results together indicate that the time of stripping of the eggs in relation to the date of ovulation is a much more significant determinant of egg quality than any of the chemical and physical aspects of egg composition which were investigated.  相似文献   

Using translational research to enhance farmers’ voice: a case study of the potential introduction of GM cassava in Kenya’s coast     

Corinne Valdivia  M. Kengo Danda  Dekha Sheikh  Harvey S. James Jr.  Violet Gathaara  Grace Mbure  Festus Murithi  William Folk 《Agriculture and Human Values》2014,31(4):673-681

Genetically modified (GM) cassava is currently being developed to address problems of diseases that threaten the food security of farmers in developing countries. The technologies are aimed at smallholder farmers, in hopes of reducing the vulnerability of cassava production to these diseases. In this paper we examine barriers to farmers’ voice in the development of GM cassava. We also examine the role of a translational research process to enhance farmers’ voice, to understand the sources of vulnerability farmers in a group in Kenya’s Coast face, and to determine if their concerns are consistent with those of the scientists in agriculture addressing farmers’ needs. A two-way communication participatory process provided insights into the complex vulnerability context of farmers, their primary concerns with processing and markets of cassava in order to improve livelihoods, the lack of networks with two way communication flows, and the lack of information on GM technologies. The translational research engaged farmers and scientists in an iterative process where scientists are learning what farmers need, and farmers are learning about the potential benefits and risks from GM technologies, while at the same time expressing their concerns.  相似文献   

Anthony Winson: The industrial diet: the degradation of food and the struggle for healthy eating     

Harvey S. James Jr. 《Agriculture and Human Values》2014,31(4):691-692

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Case studies on smallholder farmer voice: an introduction to a special symposium     

Harvey S. James Jr.  Iddisah Sulemana 《Agriculture and Human Values》2014,31(4):637-641

In the spring of 2013, project leaders who received funding from the John Templeton Foundation’s program “Can GM Crops Help to Feed the World?” met in England to discuss progress on funded projects and to identify common objectives and research interests. The collection of essays in this special symposium is one outcome of that meeting. This introduction provides background on the symposium’s theme of understanding the challenges to smallholder farmers having a voice. Farmer voice is important not only in debates about genetically modified crops but also for policies, technologies and other efforts designed by interests seeking ostensibly to improve the livelihoods of smallholder farmers.  相似文献   

Direct detection of soil mRNAs using targeted microarrays for genes associated with lignin degradation     

Vanessa L. Bailey  Sarah J. Fansler  Jeffrey L. Smith  Harvey Bolton 《Soil biology & biochemistry》2010,42(10):1793-1799

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Advertisers, Exhibitors, and Collaborative Ventures     

Colin E. Harvey 《Veterinary surgery : VS》1985,14(3):2A-2A

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Effect of active immunization against growth hormone-releasing factor on growth and onset of puberty in beef heifers.   总被引：1，自引：0，他引：1  

R B Simpson  J D Armstrong  R W Harvey  D C Miller  E P Heimer  R M Campbell 《Journal of animal science》1991,69(12):4914-4924

Angus and Charolais heifers (195 +/- 7 kg) were actively immunized against growth hormone-releasing factor (GRF) to evaluate the effect on concentrations of somatotropin (ST), insulin-like growth factor I (IGF-I), insulin (INS), growth, and onset of puberty. Primary immunizations were given at 184 +/- 7 d of age (d 0 of experiment) by injecting (s.c.) 1.5 mg of GRF-(1-29)-Gly-Gly-Cys-NH2 conjugated to 1.5 mg of human serum albumin (GRFi, n = 22) or 1.5 mg of human serum albumin (HSAi, n = 21). Booster immunizations of .5 mg of antigen were given on d 62, 92, 153, and 251. Antibody binding (percentage at 1:2,000 dilution) to [125I]GRF on d 69 was greater (P less than .01) in GRFi (53.7 +/- 4.5) than in HSAi (10.1 +/- .6) heifers. Serum concentration (ng/ml) and frequency (peaks/5 h) of ST release, respectively, on d 78 were lower (P less than .01) in GRFi than in HSAi heifers (3.3 +/- .1 vs 5.6 +/- .2 and .9 +/- .3 vs 2.3 +/- .2). Serum IGF-I (ng/ml) was lower (P less than .01) in GRFi than in HSAi heifers on d 69 (41 +/- 5 vs 112 +/- 4). Serum INS (microU/ml) on d 78 was lower (P less than .05) in GRFi (2.2 +/- .1) than in HSAi (3.8 +/- .2) heifers. Feed intake, ADG, and feed efficiency were lower (P less than .05) in GRFi than in HSAi heifers. Hip height was lower (P less than .01) and fat thickness was greater (P less than .05) in GRFi than in HSAi heifers by d 132 and 167, respectively. Percentage of heifers attaining puberty (progesterone greater than 1 ng/ml for two consecutive weeks) by d 209 and 379 (12.9 and 18.5 mo of age), respectively, was lower (P less than .05) in GRFi (40.9 and 45.5) than in HSAi (81.0 and 100). In conclusion, growing heifers were successively immunized against GRF. Active immunization against GRF resulted in decreased serum concentration of ST, IGF-I, and INS. In addition, GRF immunization led to lowered feed intake, ADG, and feed efficiency, increased fat depth, and delayed onset of puberty in heifers. We propose that ST and IGF-I are important metabolic mediators involved in the initiation of puberty in heifers.  相似文献   

Endocrine changes in the fowl during infection with Eimeria maxima     

T F Davison  H D Chapman  S Harvey 《Research in veterinary science》1985,38(3):296-300

Plasma concentrations of thyroxine (T4), triiodothyronine (T3), prolactin, growth hormone and corticosterone were measured in immature domestic fowl which were infected with Eimeria maxima, uninfected but given the same amount of food as those infected (pair-fed) or fed ad libitum. Infection with E maxima caused a decrease in plasma T4 concentration whereas pair feeding caused an increase when food intake was minimal. Plasma T3 concentrations were decreased similarly in both infected and pair-fed birds. Infection caused an increase in plasma prolactin concentration, whereas pair-feeding did not. The plasma concentration of growth hormone was not affected by any of the treatments. Plasma corticosterone concentration was markedly increased on days 5 and 6 in pair-fed birds but was not affected by infection with E maxima.  相似文献   

Economy     

Harvey Franklin 《Asia Pacific viewpoint》1991,32(2):156-162

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