bluuebunny/crossref_metadata_2025_split huggingface dataset:
ANTIPROTOZOAN IMMUNIZATION STUDIES IN THE CHANNEL CATFISH, Ictalurus punctatus
Authors: Goven Beverly A. , Dawe Donald L. , Gratzek John B. 
Published: August 2010

ABSTRACTThe antigenic relation between Tetrahymena pyriformis (Ehrenberg, 1830) Lwoff, 1947 and Ichthyophthirius multifiliis Fouquet 1876 was investigated using various in vitro immunologic tests. Tomites of I. multifiliis exposed to dilutions of rabbit anti‐tetrahymena serum were immobilized in 24 hours. Tetrahymena in this test system were agglutinated at low dilutions and immobilized at higher dilutions. Using an indirect fluorescent antibody test, both organisms showed fluorescence when treated with either rabbit anti‐tetrahymena serum or anti‐tomite serium. In heterologous crosses, titers of 1:1024 were obtained using the passive hemagglutination test. These results indicate than an antigenic relationship does exist between these two organisms, cross‐reacting antigens appearing to be localized on the cilia.Channel catfish Ictalurus punctatus Rafinesque were immunized with ciliary and whole cell preparations of I. multifiliis and subsequently challenged with I. multifiliis. Similar T. pyriformis preparations were used to determine if this heterologous immunization would elicit a protective immune response against I. multifiliis infestation. Results indicate that various degrees of protective immunity were induced with all antigen preparations. T. pyriformis ciliary antigens provided the greatest degree of protection. Four doses of antigen, ranging from 25 μg to 1.0 μg were used to determine if the immunizing dosage influenced the degree of protective immunity conferred.
GROWTH AND CONVERSION EFFICIENCY OF JUVENILE AMERICAN LOBSTERS (Homarus americanus) IN RELATION TO TEMPERATURE AND FEEDING LEVEL
Authors: Bartley Devin M. , Carlberg James M. , Van Olst Jon C. , Ford Richard F. 
Published: August 2010

ABSTRACTJuvenile lobsters were maintained in recirculating seawater systems at temperatures of 10, 15, 20 and 25°C. At each constant temperature, groups of 25 lobsters were fed rations of 0, 1, 2 and 4% of their body weight per day; 25 lobsters were also fed to excess at each temperature.For the starvation groups, time to 50% mortality (LT50) varied inversely with temperature. At 10°C the LT50 was 114 days while at 20°C it was only 47 days. Survival was high in all cases except for those groups starved or fed to excess, the latter indicating toxic effects from the decomposition of unconsumed food. Growth was exponential as described by the general growth equation W = αekt where W is weight, t is time and α and k are fitted parameters. Specific growth rate ranged from a low of 0.43% increase wet body weight per day at 10°C and a 1% feeding level to 1.38% at 25°C and a 4% feeding level. Gross conversion efficiency (increase in wet weight divided by dry weight of food fed) ranged from 30% at 10°C and a 4% feeding level to 91% at 15°C and a 1% feeding level. Efficiency values decreased with age. Feeding levels promoting most efficient growth and maximum growth increased with increasing temperature. The optimum combination of temperature and feeding level appears to be near 20°C and 2% of body weight.
EFFECTS OF DIETARY FIBER ON GROWTH, ASSIMILATION AND CELLULASE ACTIVITY OF THE PRAWN (Macrobrachium rosenbergii)1
Authors: Fair P. H. , Fortner A. R. , Millikin M. R. , Sick L. V. 
Published: August 2010

ABSTRACTCellulose fiber comprising up to 30% of an isonitrogenous series of diets (0, 5, 15 and 30% fiber concentration) did not suppress growth of prawn having average initial weights of 0.08 ± 0.002 g over a 12‐week period. In addition, dietary fiber concentrations of 5 and 20% were found to stimulate growth over an 8‐week period among prawn having initial average weights of 1.48 ± 0.054 g, as opposed to 0% fiber concentration, which had no significant effect on growth.Cellulase activity measured in hepatopancreas tissues by viscometric techniques was shown to be positive with a six‐fold increase in activity occurring in adult prawn (11 ± 1.16 g) when compared to smaller prawn (1 ± 0.06 g). However, activity in both sizes of prawn was not found to be proportional to increases in dietary fiber concentrations. Total organic carbon assimilation decreased while nitrogen assimilation efficiency increased in response to increasing dietary fiber concentration. Results from the present study indicated that use of dietary fiber may make a significant contribution to commercial formulations of cost‐effective crustacean diets.
A QUANTITATIVE ANALYSIS OF DIGESTIVE ENZYMES FOR THE FRESHWATER PRAWN Macrobrachium rosenbergii
Authors: Lee Phillip G. , Blake Norman J. , Rodrick Gary E. 
Published: August 2010

ABSTRACTThe specific activities of 10 different digestive enzymes, taken from the hepatopancreas of the freshwater prawn (Macrobrachium rosenbergii), were determined. The prawns were 70–110 mm in length and were fed Purina Marine Ration #25 daily.The extracts of M. rosenbergii hepatopancreas exhibited significant activity for the following enzymes: amylase, trypsin, chymotrypsin, pepsin, carboxypeptidase A and B, and leucine aminopeptidase. In addition, the lipolytic enzymes exhibited high esterase activity and only a trace of lipase activity.From this enzyme profile M. rosenbergii is appropriately classified an omnivore. The levels of specific activity reveal the prawn's ability to effectively hydrolyze Purina Marine Ration #25 and further implies that increased protein and starch levels would still be hydrolyzed efficiently. Although individual differences in activities were demonstrated, no direct relationship to sex or size could be detected.In summary, studies concerning the digestive physiology of M. rosenbergii may provide a more logical and efficient approach to its dietary requirements for mariculture.
CALCIUM AND pH REQUIREMENTS IN THE CULTURE OF BULLFROG (Rana catesbeiana) LARVAE
Authors: Marshall Gail A. , Amborski Robert L. , Culley Dudley D. 
Published: August 2010

ABSTRACTSkeletal deformities previously observed in Rana catesbeiana larvae reared in water containing <4 mg/liter calcium were suspected to be caused by calcium deficiencies. Initial studies utilizing the low calckum water showed that an increase of total calcium in the diet from 0.5 to 0.9% significantly (p< .001) reduced the frequency and severity of deformities.Mortality rates of Rana catesbeiana larvae increased significantly (p< .001) at pH levels above 8.1. Newly hatched larvae maintained for three weeks in water buffered at either pH 7.2 or 8.3 experienced mortality rates of 10.0 and 96.7%, respectively. Larvae maintained at pH 7.2 for three weeks and then at pH 8.3 for four weeks experienced higher mortality rates than did a similar group of larvae maintained at pH 7.2 for seven weeks (23.3% and 3.6% respectively). Bacteriological analysis of surviving larvae maintained at pH 7.2 or 8.3 indicated greater numbers of potentially pathogenic bacteria in the carcass and gut of larvae at pH 8.3.
MATURATION OF PENAEID SRHIMP: LIPIDS IN THE MARINE FOOD WEB
Authors: Middleditch B. S. , Missler S. R. , Hines Harry B. , Chang E. S. , McVey J. P. , Brown A. , Lawrence A. L. 
Published: August 2010

ABSTRACTWe have determined that certain lipids are required in the diets of penaeid shrimp to promote ovarian maturation. In an attempt to identify appropriate feedstock supplements which contain these lipids, we have examined several invertebrate species from two locations: West Bay, Galveston, and the Gulf of Mexico 50 km offshore from Galveston. At each location, with a few notable exceptions, the lipid profiles for the various species are very similar. This finding implies that many lipids pass through the food web unaltered and that the suitability of a particular invertebrate for inducing ovarian maturation may depend upon the diet of that invertebrate.
PRODUCTION OPTIMIZATION AND ECONOMIC ANALYSIS OF AN OYSTER (Crassostrea virginica) HATCHERY ON THE CHESAPEAKE BAY, MARYLAND, USA
Authors: Lipschultz Fredric , Krantz George E. 
Published: August 2010

ABSTRACTProduction dynamics and economics of a large‐scale oyster (Crassostrea virginica) hatchery operated by the University of Maryland were investigated using a series of Linear Programming models. Development of models was based on a year of detailed operational data and biological phenomena peculiar to the low‐salinity (12–15 ppt) hatchery site.The model successfully identified production bottlenecks. When both the model and hatchery operations were altered to alleviate a given resource constraint, the model predicted subsequent problem areas. Revisions of hatchery equipment‐mix and production methods were easily incorporated into the Linear Programming framework and the resultant effects evaluated.Economic feasibility of the oyster hatchery as a commercial venture was estimated using actual building costs at a 12% interest rate, straight‐line depreciation, and optimized production estimates. Analyses were conducted for both the current hatchery and a hatchery with a modified equipment‐mix within the same building. When both hatcheries were coupled to a harvesting operation, they were capable of a sustained gross profit after the initial start‐up, but were only marginally successful in recovering from a crop failure or any level of revenue loss. The modified equipment‐mix design demonstrated potential for marked production increases by further refinement in arrangement and use of hatchery equipment.When the model simulated the hatcheries operating solely as seed oyster facilities rather than as a component of a harvesting operation, both the current hatchery design and the redesigned hatchery demonstrated an ability to generate profit. However, this potential relies heavily on good growth conditions in the hatchery; salinity fluctuations or equipment failure could drastically reduce the hatchery output.
ECONOMIC ASPECTS OF POND CULTURE OF TOPMINNOWS (FAMILY POECILIIDAE) IN HAWAII AS AN ALTERNATIVE BAITFISH FOR SKIPJACK TUNA1
Authors: Shang Yung C. , Baldwin Wayne J. 
Published: August 2010

ABSTRACTThe unit production cost of cultured topminnow (Poecilia vittata and P. mexicana) was less than the opportunity cost of captured Nehu (Stolephorus purpureus), the traditional live baitfish used for the skipjack tuna (Katsuwonus pelamis) fishing in Hawaii. The production cost of culture topminnow was estimated in the range of $3.20‐6.06 per kg, while the estimated opportunity cost of Nehu was about $22.00 per kg.
GENETIC STUDIES OF THE BLUE MUSSEL, Mytilus edulis, AND THEIR IMPLICATIONS FOR COMMERCIAL CULTURE
Authors: Newkirk G. F. , Freeman K. R. , Dickie L. M. 
Published: August 2010

ABSTRACTGenetic differences among natural populations of the blue mussel (Mytilus edulis) appear to have implications for commercial exploitation of the species. Growth and mortality patterns in transplanted versus resident wild stocks presented here verify that the genetic differences among populations involve the production parameters. Hatchery produced juveniles from various populations outplanted at different sites showed different mean growth rates depending on parent stock. These observations suggest there are adaptations to local conditions and underscore the need for careful selection by the mariculturist of both site and source of seed stock.
Normalizers of 2-subgroups in black-box groups
Authors: Rowley Peter , Taylor Paul 
Published: August 2010

AbstractIn this paper we refine and extend the applicability of the algorithms in Bates and Rowley (Arch. Math. 92 (2009) 7–13) for computing part of the normalizer of a 2-subgroup in a black-box group.Supplementary materials are available with this article.
The Mordell–Weil sieve: proving non-existence of rational points on curves
Authors: Bruin Nils , Stoll Michael 
Published: August 2010

AbstractWe discuss the Mordell–Weil sieve as a general technique for proving results concerning rational points on a given curve. In the special case of curves of genus 2, we describe quite explicitly how the relevant local information can be obtained if one does not want to restrict to mod p information at primes of good reduction. We describe our implementation of the Mordell–Weil sieve algorithm and discuss its efficiency.Supplementary materials are available with this article.
Students come to medical schools prepared to cheat: a multi-campus investigation
Authors: Kukolja Taradi Sunčana , Taradi Milan , Knežević Tin , Đogaš Zoran 
Published: August 2010

ObjectivesTo investigate high school cheating experiences and attitudes towards academic misconduct of freshmen at all four medical schools in Croatia, as a post-communist country in transition, with intention of raising awareness of academic (dis)honesty.Design and methodStudents were given an anonymous questionnaire containing 22 questions on the atmosphere of integrity at their high school, self-reported educational dishonesty, their evaluation of cheating behaviour, and on their expectations about the atmosphere of integrity at their university.SettingAll schools of medicine of Croatian universities (Zagreb, Rijeka, Split and Osijek).Main measuresDescriptive statistics and differences in students' self-reported educational dishonesty, perception of cheating behaviour, and perception of the high school integrity atmosphere.ResultsOf the 761 freshmen attending the four medical schools, 508 (67%) completed the questionnaire: 481 Croatian and 27 international students. Of the Croatian respondents, almost all (>99%) self-reported engaging in at least one behaviour of educational dishonesty, and 78% of respondents admitted to having frequently cheated in at least one form of assessed academic misconduct. Only three students admitted to having reported another student for cheating. For most of the questions, there was no significant difference in the responses among Croatian students. However, significant differences were found in most responses between Croatian students and their international counterparts, who were significantly less likely to engage in dishonest behaviours. No individual factor was found to correlate with the incidence of self-admitted dishonest behaviour. Frequent cheaters evaluated academic dishonesty significantly more leniently than those who did not cheat.ConclusionAcademic dishonesty of university students does not begin in higher education; students come to medical schools ready to cheat.
A long term study of pulmonary function among US refractory ceramic fibre workers
Authors: McKay Roy T , LeMasters Grace K , Hilbert Timothy J , Levin Linda S , Rice Carol H , Borton Eric K , Lockey James E 
Published: August 2010

BackgroundCross-sectional studies have shown declines in lung function among refractory ceramic fibre (RCF) workers with increasing fibre exposure. This study followed current and former workers (n=1396) for up to 17 years and collected 5243 pulmonary function tests.MethodsCumulative fibre exposure and production years were categorised into exposure levels at five manufacturing locations. Conventional longitudinal models did not adequately partition age-related changes from other time-dependent variables. Therefore, a restricted cubic spline model was developed to account for the non-linear decline with age.ResultsCumulative fibre >60 fibre-months/cc showed a significant loss in lung function at the first test. When results were examined longitudinally, cumulative exposure was confounded with age as workers with the highest cumulative exposure were generally older. A longitudinal model adjusted by age groups was implemented to control for this confounding. No consistent longitudinal loss in lung function was observed with RCF exposure. Smoking, initial weight and weight increase were significant factors.ConclusionNo consistent decline was observed longitudinally with exposure to RCF, although cross-sectional and longitudinal findings were discordant. Confounding and accelerated lung function declines with ageing and the correlation of multiple time-dependent variables should be considered in order to minimise error and maximise precision. An innovative statistical methodology for these types of data is described.
Occupational exposure to electromagnetic fields and sex-differential risk of uveal melanoma
Authors: Behrens Thomas , Lynge Elsebeth , Cree Ian , Sabroe Svend , Lutz Jean-Michel , Afonso Noemia , Eriksson Mikael , Guénel Pascal , Merletti Franco , Morales-Suarez-Varela Maria , Stengrevics Aivars , Févotte Joëlle , Llopis-González Agustin , Gorini Giuseppe , Sharkova Galina , Hardell Lennart , Ahrens Wolfgang 
Published: August 2010

ObjectivesThe association between occupational exposure to electromagnetic fields (EMF) and the risk of uveal melanoma was investigated in a case–control study in nine European countries.MethodsIncident cases of uveal melanoma and population as well as hospital controls were included and frequency matched by country, 5-year birth cohort and sex. Subjects were asked whether they had worked close to high-voltage electrical transmission installations, computer screens and various electrical machines, or in complex electrical environments. Measurements of two Scandinavian job–exposure matrices were applied to estimate lifelong cumulative EMF exposure. Unconditional logistic regression analyses, stratified by sex and eye colour were calculated, adjusting for several potential confounders.Results293 patients with uveal melanoma and 3198 control subjects were interviewed. Women exposed to electrical transmission installations showed elevated risks (OR 5.81, 95% CI 1.72 to 19.66). Positive associations with exposure to control rooms were seen among men and women, but most risk increases were restricted to subjects with dark iris colour. Application of published EMF measurements revealed stronger risk increases among women compared to men. Again, elevated risks were restricted to subjects with dark eye colour.ConclusionAlthough based on a low prevalence of exposure to potential occupational sources of EMF, our data indicate that exposed dark-eyed women may be at particular risk for uveal melanoma.
Use of mobile phones and changes in cognitive function in adolescents
Authors: Thomas S , Benke G , Dimitriadis C , Inyang I , Sim M R , Wolfe R , Croft R J , Abramson M J 
Published: August 2010

BackgroundSeveral studies have investigated the impact of mobile phone exposure on cognitive function in adults. However, children and adolescents are of special interest due to their developing nervous systems.MethodsData were derived from the Australian Mobile Radiofrequency Phone Exposed Users' Study (MoRPhEUS) which comprised a baseline examination of year 7 students during 2005/2006 and a 1-year follow-up. Sociodemographic and exposure data were collected with a questionnaire. Cognitive functions were assessed with a computerised test battery and the Stroop Color-Word test.Results236 students participated in both examinations. The proportion of mobile phone owners and the number of voice calls and short message services (SMS) per week increased from baseline to follow-up. Participants with more voice calls and SMS at baseline showed less reductions in response times over the 1-year period in various computerised tasks. Furthermore, those with increased voice calls and SMS exposure over the 1-year period showed changes in response time in a simple reaction and a working memory task. No associations were seen between mobile phone exposure and the Stroop test.ConclusionsWe have observed that some changes in cognitive function, particularly in response time rather than accuracy, occurred with a latency period of 1 year and that some changes were associated with increased exposure. However, the increased exposure was mainly applied to those who had fewer voice calls and SMS at baseline, suggesting that these changes over time may relate to statistical regression to the mean, and not be the effect of mobile phone exposure.
Mortality from liver cancer and leukaemia among polyvinyl chloride workers in Taiwan: an updated study
Authors: Hsieh Hui-I , Chen Pau-Chung , Wong Ruey-Hong , Du Chung-Li , Chang Yu-Yin , Wang Jung-Der , Cheng Tsun-Jen 
Published: August 2010

ObjectivesTo investigate types of cancer caused by occupational exposure to vinyl chloride monomer (VCM) and the temporal mortality trends of these cancers in workers from polyvinyl chloride (PVC) manufacturing factories in Taiwan, with follow-up of the cohort extended by 15 years, from 1980 to 2007.MethodsA retrospective cohort study of workers from six PVC factories in Taiwan was conducted. 3336 male PVC workers were enrolled and further linked with the National Mortality Registry and National Household Registry databases. Standardised mortality ratios (SMR) with 95% CIs were calculated and compared to the general Taiwanese male population. Cause-specific mortality between two study periods, 1980–1997 and 1998–2007, was compared. Six-year moving averages of the SMRs were calculated to examine mortality trends.ResultsLiver cancer mortality increased during 1989–1994 (SMR 1.90, 95% CI 1.01 to 3.25), reached a peak during 1991–1996 (SMR 2.31, 95% CI 1.39 to 3.61) and became non-significant during 1994–1999 (SMR 1.42, 95% CI 0.80 to 2.34). Leukaemia mortality significantly increased during 1984–1989 (SMR 6.06, 95% CI 1.24 to 17.53), reached a peak during 1985–1990 (SMR 7.56, 95% CI 2.06 to 19.35) and became non-significant during 1991–1996 (SMR 3.24, 95% CI 0.39 to 11.69). The mortality trend for haemolymphopoietic cancer showed a similar pattern to that of leukaemia.ConclusionsVCM may increase the risk of liver cancer and leukaemia. When VCM exposure was controlled at worksites, mortality from these cancers returned to background levels.
Participation in a population-based physical activity programme as an aid for smoking cessation: a randomised trial
Authors: Bize Raphaël , Willi Carole , Chiolero Arnaud , Stoianov Rebecca , Payot Sylvie , Locatelli Isabella , Cornuz Jacques 
Published: August 2010

ObjectivesExercise combined with nicotine therapy may help smoking cessation and minimise weight gain after quitting. Low participation in vigorous-intensity physical activity programmes precludes their population-wide applicability. In a randomised controlled trial, we tested whether a population-based moderate-intensity physical activity programme increases quit rates among sedentary smokers receiving nicotine therapy.MethodsParticipants (n=481; 57% male; mean age, 42.2 years (SD 10.1); mean cigarette consumption, 27 (SD 10.2) per day) were offered a nine-week smoking cessation programme consisting of a weekly 15-minute counselling session and the prescription of nicotine replacement therapy. In addition, participants in the physical activity group (n=229) also took part in a programme of moderate-intensity physical activity implemented at the national level, and offering nine weekly 60-minute sessions of physical activity. To ensure equal contact conditions, participants in the control group (n=252) attended weekly 60-minute health behaviour education sessions unrelated to physical activity. The primary outcome was continuous CO-verified smoking abstinence rates at 1-year follow-up.ResultsContinuous smoking abstinence rates were high and similar in the physical activity group and the control group at the end of the intervention (47% versus 46%, p=0.81) and at 1-year follow-up (27% versus 29%, p=0.71). The mean weight gain after one year was 4.4 kg and 6.2 kg among sustained quitters of the physical activity and control groups, respectively (p=0.06).ConclusionParticipation in a population-based moderate-intensity physical activity programme for 9 weeks in addition to a comprehensive smoking cessation programme did not significantly increase smoking cessation rates. A non-significant reduction in weight gain was observed among participants who quit smoking in the physical activity group.Trial registrationClinicalTrials.gov; US National Institutes for Health (available online athttp://clinicaltrials.gov/; Clinical Trial Registration Number:NCT00521391)