bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic variation in organisms with sexual and asexual reproduction
Authors: Bengtsson B. O. 
Published: March 2003

Abstract
The genetic variation in a partially asexual organism is investigated by two models suited for different time scales. Only selectively neutral variation is considered. Model 1 shows, by the use of a coalescence argument, that three sexually derived individuals per generation are sufficient to give a population the same pattern of allelic variation as found in fully sexually reproducing organisms. With less than one sexual event every third generation, the characteristic pattern expected for asexual organisms appear, with strong allelic divergence between the gene copies in individuals. At intermediary levels of sexuality, a complex situation reigns. The pair-wise allelic divergence under partial sexuality exceeds, however, always the corresponding value under full sexuality. These results apply to large populations with stable reproductive systems. In a more general framework, Model 2 shows that a small number of sexual individuals per generation is sufficient to make an apparently asexual population highly genotypically variable. The time scale in terms of generations needed to produce this effect is given by the population size and the inverse of the rate of sexuality.
Testing the link between the latitudinal gradient in species richness and rates of molecular evolution
Authors: Bromham L. , Cardillo M. 
Published: March 2003

Abstract
Numerous hypotheses have been proposed to explain latitudinal gradients in species richness, but all are subject to ongoing debate. Here we examine Rohde's (1978, 1992) hypothesis, which proposes that climatic conditions at low latitudes lead to elevated rates of speciation. This hypothesis predicts that rates of molecular evolution should increase towards lower latitudes, but this prediction has never been tested. We discuss potential links between rates of molecular evolution and latitudinal diversity gradients, and present the first test of latitudinal variation in rates of molecular evolution. Using 45 phylogenetically independent, latitudinally separated pairs of bird species and higher taxa, we compare rates of evolution of two mitochondrial genes and DNA–DNA hybridization distances. We find no support for an effect of latitude on rate of molecular evolution. This result casts doubt on the generality of a key component of Rohde's hypothesis linking climate and speciation.
Acute haemolytic transfusion reactions due to weak antibodies that in vitro did not seem to be clinically significant
Authors: Hoppe B. , Pastucha L. , Seltsam A. , Greinacher A. , Salama A. 
Published: March 2003

Background and Objectives In the present article, we report on two patients with acute haemolytic transfusion reactions (AHTRs), and whom we were unable to transfuse, owing to alloantibodies that in vitro did not seem to be clinically significant.Materials and Methods The patients were a 67‐year‐old male and a 64‐year‐old female, both of whom developed antibodies to red blood cells (RBCs) after repeat blood transfusions. Serological analyses were carried out using standard techniques.Results Both patients developed an AHTR of the intravascular type following blood transfusions. Serological re‐examination revealed weakly reactive alloantibodies with anti‐JMH specificity in one patient, and with unclear specificity in the second. Rechallenging the patients with 15–30 ml of packed RBCs caused AHTRs, and blood transfusion became impossible in both cases.Conclusion Weak alloantibodies that in vitro do not seem to be clinically significant may cause severe AHTRs.
Knowledge about blood donation among a sample of Thai university students
Authors: Wiwanitkit V. 
Published: March 2003

Background and Objectives Blood banks in Thailand use only a voluntary donation system. Although this has been established for many years, the quantity of blood is still insufficient. Knowledge about blood donation and attitudes toward it are inadequate, especially in rural areas. The registry data of the National Blood Centre, Thai Red Cross Society, indicate that most voluntary blood donors are university students. The present study was therefore conducted among the students of Chulalongkorn University to assess their knowledge of voluntary, non‐remunerated blood donation.Materials and Methods Four hundred students participated in this study. A self‐administered questionnaire and face‐to‐face interview on various aspects of blood donation were used for data collection.Results Although most participants (80%) knew about blood donation, only 11% (44 subjects) had ever donated blood voluntarily. We found no significant correlation between demographic data (gender, age, educational level of subjects studied) and such knowledge or actual blood donation. Among the non‐donor respondents, fear (305 cases) was the most common reason for not donating blood.Conclusions Greater knowledge about blood donation does not lead to donation. Therefore, specific campaigns are needed to convert this into actual voluntary donation.
Impact of donor arm skin disinfection on the bacterial contamination rate of platelet concentrates
Authors: Lee C. K. , Ho P. L. , Chan N. K. , Mak A. , Hong J. , Lin C. K. 
Published: March 2003

Background and Objectives Despite improved methods for detecting bacterial contamination of blood products, bacterial sepsis remains a significant risk in blood transfusion. This study was undertaken to investigate whether adopting a different skin disinfection protocol could reduce the rate of bacterial contamination of platelet concentrates.Materials and Methods Two skin disinfection protocols were consecutively used in the routine blood collection setting during two 10‐month periods: 0·5% cetrimide/0·05% chlorhexidine solution followed by 70% isopropyl alcohol (first 10‐month time‐period); and 10% povidone‐iodine followed by 70% isopropyl alcohol (second 10‐month time‐period). The rates of bacterial contamination of platelet concentrates were monitored by using a surveillance programme described previously.Results The overall bacterial contamination rate in the first time‐period was 0·072%. After introduction of the povidone‐iodine and isopropyl alcohol protocol, the bacterial contamination rate decreased to 0·042% (relative risk reduction: −0·42; 95% confidence interval, −0·12 to −0·61, P= 0·009). There were no differences in the types of micro‐organisms identified (P = 0·7).Conclusions Skin disinfection by povidone‐iodine and isopropyl alcohol is more effective than that by cetrimide/chorhexidine and isopropyl alcohol in reducing venepuncture‐associated contamination of platelet concentrates by skin flora. Our data indicate that the disinfection protocol should be used on a routine basis and such implementation should translate into a significant improvement in blood safety to patients receiving platelet transfusion.
Incorporation of an additional viral‐clearance step into a human immunoglobulin manufacturing process
Authors: Van Holten R. W. , Ciavarella D. , Oulundsen G. , Harmon F. , Riester S. 
Published: March 2003

Background and Objectives Regulatory agencies have mandated that manufacturers of immunoglobulin products incorporate robust viral inactivation or removal steps into their purification processes. We evaluated the effectiveness of incorporating nanofiltration, a generic virus‐clearance step, into an existing plasma‐fractionation process for a human anti‐D immunoglobulin product.Materials and Methods The nanofiltration process studied utilizes a 180 000‐molecular weight composite membrane with well‐defined pore distribution. To examine its viral‐clearance capability, diluted anti‐D immunoglobulin was spiked with high concentrations of human and animal model viruses and subjected to tangential‐flow nanofiltration during scaled‐down validation runs. Viral clearance by the membrane was determined by calculating log removal values in accordance with guidelines provided by US and European regulatory agencies.Results Nanofiltration removed viruses of varying sizes and physical characteristics. For the three non‐enveloped viruses tested (porcine parvovirus, encephalomyocarditis virus and hepatitis A virus, sizes 18–30 nm), clearance was 3·3, 4·1 and > 5·1 log, respectively. For the three enveloped viruses (human immunodeficiency virus‐1, bovine viral diarrhoea virus and pseudorabies virus, 50–200 nm), a substantial 5‐log reduction was demonstrated. Product potency, purity and stability were unaffected.Conclusion Tangential‐flow nanofiltration provides substantial virus‐removal capabilities for immunoglobulin preparations.
Alloimmunization to RhD antigen in RhD‐incompatible haemopoietic cell transplants with non‐myeloablative conditioning
Authors: Mijovic A. 
Published: March 2003

Background and Objectives Following exposure to RhD antigen, anti‐D develops in up to 20% of RhD‐negative patients on chemotherapy, but seldom in the recipients of haemopoietic cell (HC) or solid‐organ transplants. Data on anti‐D formation come from HC transplants using myeloablative conditioning; no data are available for the non‐myeloablative HC transplants. The two types of transplant have a distinct isohaemagglutinin disappearance rate and different kinetics of post‐transplant red‐cell engraftment. The objective of the study was to analyse anti‐D formation in patients receiving non‐myeloablative transplants from RhD‐incompatible donors.Materials and Methods Sixteen patients were analysed: nine RhD‐negative recipients of RhD‐positive haemopoietic cells; and seven RhD‐positive recipients of a graft from a RhD‐negative donor. Patients were sequentially tested for irregular antibodies, as well as donor/recipient chimerism by cytogenetics and analysis of DNA variable‐number tandem repeats.Results Despite having received 7–499 ml of D‐positive red cells, none of the RhD‐negative recipients developed anti‐D. The median follow‐up was 202 days. By contrast, anti‐D was identified in one of seven RhD‐positive recipients of an RhD‐negative graft.Conclusions Non‐myeloablative conditioning containing fludarabine and/or Campath 1H, with cyclosporin A given post‐transplant, effectively prevents anti‐D formation in RhD‐negative recipients of a RhD‐positive graft. However, anti‐D developed in an RhD‐positive recipient of an RhD‐negative graft, who was also exposed to RhD‐positive blood products before and after the transplant. Transfusion of RhD‐positive products should be avoided in such patients.
Paying for blood donations: still a risk?
Authors: Van Der Poel C. L. , Seifried E. , Schaasberg W. P. 
Published: March 2003

It is presently disputed whether studies indicating a higher risk of infectious diseases among paid blood donors are lessons of the past, or still hold relevance. Comparative studies published between 1968 and 2001 were assessed for a possible trend of change in the relative risk for infectious disease markers between paid and unpaid blood or plasma donors. Studies reporting that paid donors had lower risk were found, but most studies, including recent ones, continued to report that paid donors have higher rates of infectious disease markers than unpaid donors. By log‐linear regression analysis of the relative risk estimates for infectious disease markers among paid and unpaid donors from 28 published data sets, evidence was not found to indicate that the difference in risk for infectious disease markers between paid donors and unpaid donors had diminished over time (P = 0·128, not significant). Paid donors are still more likely than unpaid donors to donate blood in the period during which infectious donations escape detection by blood‐screening tests (the ‘window‐period’). Therefore, paid donations have a higher risk that labile blood components (such as red blood cells and platelets) are infected. Additional safety measures for handling plasma donations, and the preparation, purification and viral‐inactivation steps employed for the production of plasma derivatives, may render the difference in infectious disease marker rates in donors irrelevant for plasma products. However, not all viruses are inactivated and paid donors were repeatedly found to have higher frequencies of markers for emerging agents. In a quality system, critical steps of the process should be addressed, and selection of the donor population is one of the first steps in this process. It is advised that blood establishments present yearly reports (with complete and raw data) to authorities on the incidence and prevalence of infectious disease markers among their donors as an ongoing surveillance on the ‘quality’ of their donor populations. Paid blood or plasma donors still have higher rates for infectious disease markers than unpaid donors.
The use of ultrapurified bovine hemoglobin solution in the treatment of two cases of presumed red maple toxicosis in a miniature horse and a pony
Authors: Vin Ron , Bedenice Daniela , Rentko Virginia T. , Paradis Mary Rose 
Published: March 2003

AbstractObjective:To report the use of ultrapurified bovine hemoglobin (PBHg) in the treatment of red maple toxicosis in horses.Summary:The use of PBHg in a miniature horse and a pony with clinical signs of red maple toxicosis is described. Initial treatment of the horses included blood transfusion in Case 1, and intravenous crystalloid fluids, nasogastrically administered mineral oil, and activated charcoal in both cases. Both cases received PBHg (16 and 11 ml/kg, respectively) when the hematocrit dropped below 10%. Clinical stabilization of the horses (reflected by improved vital signs and mucous membrane color, increase in PvO2, and increase in plasma hemoglobin) was temporary, lasting 12 and 42 hours, respectively. A whole blood transfusion was given 16 hours after the infusion of PBHg in Case 1 and 42 hours after the infusion of PBHg in Case 2. The horses were discharged on days 15 and 17, respectively. Both were stable on discharge and were reported to be doing well 1 month after discharge.New information provided:Ultrapurified bovine hemoglobin is shown to be safe in the treatment of red maple toxicosis. Ultrapurified bovine hemoglobin infusion resulted in temporary improvement in oxygen (O2) delivery as assessed by clinical and laboratory parameters. The use of PBHg may provide an ‘oxygen bridge’ in an acute hemolytic crisis in the horse. It may allow additional time in the treatment of red maple toxicity for the acute hemolysis to subside and for metabolism of the toxin to occur, thus providing a more optimal environment for an effective whole blood transfusion.
Effects of Rate and Time of Potassium Application on Cotton Yield and Quality in Turkey
Authors: Gormus O. 
Published: March 2003

AbstractStudies were conducted at Adana, in the Çukurova region of southern Turkey, to evaluate the effects of the rate and timing of application of soil‐applied potassium (K) on cotton (Gossypium hirsutum L.) in 1999 and 2000. Potassium rates of 0, 80, 160 and 240 kg K2O ha−1 were soil‐applied in single treatments (all at early boll development) or in split treatments (1/2 at first square and 1/2 at first white flower; 1/4 at first square, 1/4 at first white flower and 1/2 at early boll development). Data collected in the two years indicated that application of 160 kg K2O ha−1 produced significant differences in seed‐cotton yield, lint yield and boll weight compared with the untreated control. The best combination producing the greatest yield was application of 160 kg K2O ha−1 with all of the K soil‐applied at early boll development. Cotton yields did not respond to K fertilization above the rate of 160 kg K2O ha−1 under the production practices typically found in the region. For application of K at a rate of 240 kg K2O ha−1 there was a marked difference in fibre strength between years in this study, but micronaire and uniformity ratio were not different amongst K rates within each year. When the total amount of K was applied at early boll development, higher yields, boll weights and lint turnouts were obtained compared with split applications, but the single application did not have a large impact on fibre properties.
Defoliation Regime Effects on Accumulated Season‐long Herbage Yield and Quality in Boreal Grassland
Authors: Donkor N. T. , Bork E. W. , Hudson R. J. 
Published: March 2003

AbstractWithin boreal grasslands, little information exists on the effects of initial defoliation date, frequency, and intensity on accumulated herbage yield and quality. We investigated the effects of initial defoliation in May, June or July, at heights of 5, 10 or 15 cm, and repeated at 2‐, 4‐ or 6‐week intervals throughout the growing season. Harvested material was combined with year‐end residual biomass, and examined for herbage removed, crude protein (CP), crude protein yield (CPY) and neutral detergent fibre (NDF). Compared to single defoliated check plots, total, grass and forb dry matter (DM) yields were lower under repeated defoliation by 25, 38 and 17 %, respectively. The majority of total herbage produced was harvested in the spring clipping. Total, grass and forb DM yields peaked under moderate (10 cm) clipping. Total DM and grass biomass were maximized with long (6 week) recovery periods. In contrast, forb biomass was greatest with May defoliation followed by a 4‐week interval. While maximum grass CPY was found under 10‐cm defoliation, forb CPY peaked with early and moderate to intensive defoliation. These results indicate that season‐long herbage biomass, along with CPY, can be maximized in boreal grasslands through controlled defoliation.
A critical review of the value of genetic distance studies in conservation of animal genetic resources
Authors: Ruane J. 
Published: March 2003

IntroductionThere has been a veritable explosion of projects in recent years aiming to calculate genetic distances between domesticated breeds of animals and the number of such projects is still increasing. The extent of this can be appreciated by a glance at the recent proceedings of the 26th International Conference on Animal Genetics (ISAG 1998). All domesticated species are being targeted, using breeds from both developed and developing countries and projects are now almost exclusively based on microsatellite marker loci. Although the goal in a few cases is to provide insights into the history of animal domestication (see, for example, M acH
ugh et al. 1997; L
au et al. 1998), the most common justification for genetic distancing projects is their importance for helping the decision‐makers to identify genetically unique breeds so that they may be prioritized for breed conservation purposes (e.g. H
all and B
radley 1995; M
oazami‐G
uodarzi et al. 1997; C
rawford and L
ittlejohn 1998).On a world‐wide basis there are roughly 3000 breeds and breed varieties of the seven major mammalian species – cattle, pig, sheep, goat, horse, donkey and buffalo (FAO 1995). Of those with population data, 23% are either endangered or critical (FAO 1995). In addition, in the current century it is estimated that at least 600 breeds have been lost (H all and R
uane 1993). On the poultry side, the picture is even worse as over half the breeds of the five major species (chicken, domestic duck, muscovy duck, goose and turkey) are thought to be endangered or critical (FAO 1995). At the same time, there is often a lack of even the most rudimentary information on many of these breeds. Basic phenotypic data, including approximate figures for population sizes, are currently available on only 50% of the world’s animal genetic resources (AGR) (H
ammond 1998).There is therefore an urgent need to act now to prevent the rapid erosion of AGR. This is especially true for breeds in developing countries, where many will be lost without ever having been adequately characterized or studied (K& ouml;
hler‐R
ollefson 1997). However, resources (both in terms of available manpower and finances) are limited in this area and appropriate use of these resources is therefore of vital importance. Given the large amount of current activity in the area of genetic distancing of domestic breeds, the aim of this article is to critically examine the value that genetic distance projects have for breed conservation.
Estimation of heritability for hip dysplasia in German Shepherd Dogs in Finland
Authors: Leppänen M. , Mäki K. , Juga J. , Saloniemi H. 
Published: March 2003

SummaryThe heritability of hip dysplasia in the German Shepherd Dog was estimated by applying the animal model and the Restricted Maximum Likelihood (REML) method to a data‐set which consisted of the hip scores of 10335 dogs. Fixed effects of the model were the month and the year of birth, screening age, the panelist responsible for screening and the origin of the animal's sire. The litter and the breeder had only minor effects on hip joints. Heritability estimates were moderate (0.31–0.35). The moderate heritability, which was found in this study, enables a much better genetic gain in the breeding programme, if proper evaluation methods, such as BLUP animal model, and effective selection is used instead of phenotypic selection.
Construction of a canine bacterial artificial chromosome library for screening with PCR
Authors: Schelling C. , Schläpfer J. , Billault A. , Guziewicz K. , Gmür A. , Katmann I. , Pineroli B. , Colomb B. , Rickli O. , Wittwer C. , Piasecka A. , Dolf G. 
Published: March 2003

SummaryWe have constructed a canine bacterial artificial chromosome library amenable to PCR screening. The library consists of 96 768 clones and was initially screened with 112 microsatellites representing all canine chromosomes. For 87 primer sets (77%) one to seven positive superpools were identified. The library will be expanded by adding additional superpools in order to increase the genome coverage. Interested researchers can access the library following the rules published at http://www.dogmap.ch.
Effect of methanol on methanogenesis and fermentation in the rumen simulation technique (RUSITEC)
Authors: Neumann L. , Weigand E. , Most E. 
Published: March 2003

Introduction  Major methanol sources in ruminant feeds are pectins esterified with methoxyl groups. Methanol can be released by pectin esterase activity of rumen bacteria (R
exova‐B
enkova and M
arkovic 1976). It has been detected in rumen fluid of cows in vivo and in vitro (V
antcheva et al. 1970, 1972). It is, however, not likely to accumulate in the rumen fluid since it can be readily used by methylotrophic organisms. Methanogenic archaebacteria such as Methanosarcina barkeri (H
utten et al. 1980; M&
uuml;
ller et al. 1986) are able to use methanol as energy and carbon source. Two equations have been reported for this conversion:4CH4 → 3CH4 + CO2 + 2 H2O(1)CH3OH + H2 → CH4 + H2O(2)Methanogenesis from methanol has been shown to occur during in vitro fermentations with rumen fluid as inoculum (C
zerkawski and B
reckenridge 1972; P
ol and D
emeyer 1988). However, acidogenic micro‐organisms, such as Eubacterium limosum or Butyribacterium methylotrophicum, may also utilize methanol. In rumen fluid of sheep fed a molasses‐rich diet, Eubacterium limosum was the predominant methanol‐utilizing bacterium (G
enthner et al. 1981). Major products of these acidogenic methylotrophs are acetate and butyrate. These different fermentation end‐products, methane versus fatty acids, will affect the metabolizable energy content of feedstuffs that are rich in highly methoxylated pectins or other methyl group‐containing compounds.The purpose of the present study was to investigate whether the rumen simulation technique (RUSITEC) would be a suitable model to evaluate the methanogenic or acidogenic potential of methanol during ruminal fermentation. The study focused on methane production, fermentation characteristics and methanol turnover. Fermentation traits included pH, redox potential, ammonia and volatile fatty acid production, and degradation of feed constituents.