bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simple model of the relationship between asymmetry and developmental stability
Authors: Houle  
Published: March 2003

Abstract
The relationship between developmental stability and morphological asymmetry is derived under the standard view that structures on each side of an individual develop independently and are normally distributed. I use developmental variance of sizes of parts, VD, as the converse of developmental stability, and assume that VD follows a gamma distribution. Repeatability of asymmetry, a measure of how informative asymmetry is about VD, is quite insensitive to the variance in VD, for example only reaching 20% when the coefficient of variation of VD is 100%. The coefficient of variation of asymmetry, CVFA, also increases very slowly with increasing population variation in VD. CVFA values from empirical data are sometimes over 100%, implying that developmental stability is sometimes more variable than any previously studied type of trait. This result suggests that alternatives to this model may be needed.
Direct and correlated responses to selection on iridoid glycosides in Plantago lanceolata L.
Authors: Marak H. B. , Biere A. , Van Damme J. M. M. 
Published: March 2003

Abstract
Plantago lanceolata L. (ribwort plantain) produces two costly terpenoid secondary plant compounds, the iridoid glycosides aucubin and catalpol. We performed an artificial selection experiment to investigate direct and correlated responses to selection on the constitutive level of iridoid glycosides in the leaves for four generations. Estimated realized heritabilities (±SE) were 0.23 ± 0.07 and 0.23 ± 0.04 for upward and downward selection, respectively. The response to upward selection was caused by selection for a developmental pattern characterized by the production of fewer leaves that on average contain more iridoids, and by selection for a development-independent increase in the level of these compounds. Significant correlated responses were observed for plant growth form. Upward selection resulted in plants with larger sized, but fewer leaves, fewer side rosettes, and fewer spikes, corresponding to a previously distinguished ‘hayfield’ ecotype, whereas downward selection produced the opposite pattern, corresponding to a ‘pasture’ ecotype. This indicates that the level of iridoid glycosides is genetically correlated with morphological traits in P. lanceolata, and is part of the complex of genetically correlated traits underlying the two ecotypes. The genetic association between iridoid level and growth forms suggests that there may be constraints to the simultaneous evolution of resistance to generalist insects (by iridoid glycosides) and to larger grazers (by a high production rate of prostrate leaves and inflorescences) in open grazed habitats where the ‘pasture’ ecotype is found.
Hatching fraction and timing of resting stage production in seasonal environments: effects of density dependence and uncertain season length
Authors: Spencer M. , Colegrave N. , Schwartz S. S. 
Published: March 2003

Abstract
Many organisms survive unfavourable seasons as resting stages, some of which hatch each favourable season. Hatching fraction and timing of resting stage production are important life history variables. We model life cycles of freshwater invertebrates in temporary pools, with various combinations of uncertain season length and density-dependent fecundity. In deterministic density-independent conditions, resting stage production begins suddenly. With uncertain season length and density independence, resting stage production begins earlier and gradually. A high energetic cost of resting stages favours later resting stage production and a lower hatching fraction. Deterministic environments with density dependence allow sets of coexisting strategies, dominated by pairs, each switching suddenly to resting stage production on a different date, usually earlier than without density dependence. Uncertain season length and density dependence allow a single evolutionarily stable strategy, around which we observe many mixed strategies with negatively associated yield (resting stages per initial active stage) and optimal hatching fraction.
Virulence and age at reproduction: new insights into host–parasite coevolution
Authors: Restif O. , Hochberg M. E. , Koella J. C. 
Published: March 2003

Abstract
We consider an explicit mutation–selection process to investigate the dynamics underlying the coevolution of parasite’s virulence and host’s prereproductive life span in a system with discrete generations. Conforming with earlier models, our model predicts that virulence generally increases with natural mortality of the host, and that a moderate increase in virulence selects for lower ages at reproduction. However, the epidemiological feedback in our model also gives rise to unusual and unexpected patterns. In particular, if virulence is sufficiently high the model can lead to a bifurcation pattern, where two strategies coexist in the host population. The first is to develop rapidly to reproduce before being infected. Individuals following this strategy suffer, however, from reduced fecundity. The second strategy is to develop much more slowly. Because of the high virulence, the effective period of transmission is short, so that a few slowly developing individuals escape infection. These individuals, although choosing a risky strategy, benefit from high fecundity.
Variation in the rate of convergent evolution: adaptation to a laboratory environment in Drosophila subobscura
Authors: Matos M. , Avelar T. , Rose M. R. 
Published: March 2003

Abstract
Adaptation to novel environments is a central issue in evolutionary biology. One important question is the prevalence of convergence when different populations adapt to the same or similar environments. We investigated this by comparing two studies, 6 years apart, of laboratory adaptation of populations of Drosophila subobscura founded from the same natural location. In both studies several life-history traits were periodically assayed for the first 14 generations of laboratory adaptation, as well as later generations, and compared with established, laboratory, control populations. The results indicated: (1) a process of convergence for all traits; (2) differences between the two studies in the pattern and rate of convergence; (3) dependence of the evolutionary rates on initial differentiation. The differences between studies might be the result of the differences in the founder populations and/or changes in the lab environment. In either case, the results suggest that microevolution is highly sensitive to genetic and environmental conditions.
Validity of the haemoglobin colour scale in blood donor screening
Authors: Lewis S. M. , Emmanuel J. 
Published: March 2003

Background and ObjectivesThe haemoglobin colour scale (HCS) has been developed as a simple, reliable and inexpensive clinical device for diagnosing anaemia and estimating its severity when laboratory‐based haemoglobinometry is not available. The purpose of this study was to assess its validity for screening blood donors for anaemia.Material and MethodsThe HCS was tested at five blood transfusion centres on a total of 2801 donors. Blood was obtained by skin puncture as part of the routine procedure at the donor sessions. HCS readings were compared with screening by the copper sulphate method, which was in routine use in the centres, and with haemoglobin (Hb) measurements by means of calibrated HemoCue haemoglobinometers. HCS readings were considered as normal when the readings were ≥ 12 g/dl.ResultsAnalysis of the paired results showed that the HCS had an accuracy of 97·5% in distinguishing subjects with normal Hb from those below the acceptable limit, when checked against the HemoCue. The HCS was more reliable than the copper‐sulphate specific‐gravity method, yielding 3·7% false readings compared with 6·1% false readings, respectively. When discrimination was set at 12 g/dl with the HemoCue, the HCS gave an incorrect reading in 2·4% of donors. The majority of these false results (44 donors; 1·58%) were caused by the HCS indicating rejection of the donor (i.e. Hb < 12 g/dl) when the correct Hb was higher, whilst in 23 donors (0·82%) the HCS incorrectly indicated a normal Hb; however, in all but four of these donors the correct Hb values were 11·0–11·9 g/dl, and none were below 10 g/dl.ConclusionThe operators were able to master the HCS technique after a few minutes of practice, and all found the test to be user friendly and easy to read. The HCS is proposed as a replacement for the copper sulphate method for blood transfusion donor selection.
Evaluation of donor arm disinfection techniques
Authors: McDonald C. P. , Lowe P. , Roy A. , Robbins S. , Hartley S. , Harrison J. F. , Slopecki A. , Verlander N. , Barbara J. A. J. 
Published: March 2003

Background and ObjectiveTo validate a standardized optimal national procedure for donor arm disinfection.Materials and MethodsA direct swabbing and plating technique was used to enumerate bacteria present on the arm pre‐ and postdisinfection. Twelve donor arm disinfection techniques were evaluated.ResultsThe Medi‐Flex Adapted method, consisting of a two‐stage process with an initial application of isopropyl alcohol followed by tincture of iodine, produced the best arm disinfection. A percentage reduction in bacterial counts of 99·79% (logarithmic reduction of 2·67) was obtained. Postdisinfection, 70% of donors had bacterial counts of zero, and 98% had counts of 10 or less.ConclusionThe Medi‐Flex disinfection method offers the English National Blood Service a validated, optimal ‘best practice’ disinfection technique and should contribute significantly to the reduction in risk of transmission of bacteria by transfusion.
Preparation and properties of an alpha‐1‐protease inhibitor concentrate with high specific activity
Authors: Mattes E. , Matthiessen H. P. , Turecek P. L. , Schwarz H. P. 
Published: March 2003

Background and ObjectivesBecause the current demand for alpha‐1‐protease inhibitor (A1PI) exceeds the available supply, we aimed to develop a process for purification of A1PI from plasma which would achieve the highest possible degree of purity, specific activity and yield.Materials and MethodsA1PI was purified from Cohn fraction IV‐1,4 using ethanol precipitation and Q‐Sepharose chromatography. Ceramic hydroxyapatite chromatography was used as a final purification step. Two independent virus‐inactivation procedures (chemical and vapour heating) were applied.ResultsThe resulting A1PI had an unprecedented high specific activity. In addition, the process led to the discovery of a new isoform of A1PI in isoelectric focusing gels.ConclusionThe high specific activity of the A1PI preparation achieved with this process should allow a reduction of the A1PI total protein load necessary to achieve clinically relevant effects.
Age of blood in inventory at a large tertiary care hospital
Authors: Owens W. , Tokessy M. , Rock G. 
Published: March 2003

Background and ObjectivesThis major tertiary care centre transfers over 1000 red cell units monthly. Units are rotated as part of inventory management to ensure minimum wastage. In 1998, the expiry date of AS3 red cells was extended from 35 to 42 days, potentially affecting inventory.Materials and MethodsThe average age of the red cell units in inventory on any given day was evaluated to determine whether the extended expiry date would affect blood availability and to determine the feasibility of using blood at different ages for various purposes. Over a 6‐month duration, 20 days were selected for review: units were categorized according to ABO group and Rh type and then analysed for age within certain categories.ResultsThe average age of the blood in inventory was 1 to 2 weeks. The probability of having units less than 1‐week old was highest for Group O and zero for Group B Rh+ and Group AB Rh+. More than 60% of the O Rh− blood was older than 28 days.ConclusionThe age of units in inventory varies with respect to ABO group, Rh type and weekday. In practice, the stock rarely reaches 42 days of age. Future studies on the effects of age of blood on patient outcome must consider the logistics of supply and the availability of blood of each group. Transfusion of large numbers of units of the same age and of a specific blood group and type may not always be possible.
Human peripheral blood Vα24+ Vβ11+ NKT cells expand following administration of α‐galactosylceramide‐pulsed dendritic cells
Authors: Okai M. , Nieda M. , Tazbirkova A. , Horley D. , Kikuchi A. , Durrant S. , Takahashi T. , Boyd A. , Abraham R. , Yagita H. , Juji T. , Nicol A. 
Published: March 2003

Background and Objectives We have undertaken the first clinical trial involving the administration of α‐GalactosylCeramine (α‐GalCer)‐pulsed dendritic cells (DCs) to human subjects, to determine safety, optimal dose, optimal administration route and immunological effects.Materials and Methods Subjects (n = 4) with metastatic malignancy received two infusions of α‐GalCer‐pulsed DCs intravenously, and two infusions intradermally. The percentages of Vα24 Vβ11 NKT cells in peripheral blood (PB) were determined by three‐colour flow cytometry and the PB NKT cell numbers were calculated using the total number of PB lymphocytes/ml determined by automated full‐blood counts.Results No serious treatment related adverse events were observed during the study period. Administration of α‐GalCer‐pulsed DCs in vivo can significantly (P < 0·03) increase PB Vα24+ Vβ11+ NKT cell numbers above pretreatment baseline levels after the transient fall in the NKT numbers within 48 h.Conclusions Administration of α‐GalCer‐pulsed DCs is well tolerated, modulates PB Vα24+ Vβ11+ NKT cells and may have a role in the therapy of malignancies sensitive to activities of Vα24+ Vβ11+ NKT cells, or for autoimmune diseases.
Large‐scale production and properties of human plasma‐derived activated Factor VII concentrate
Authors: Tomokiyo K. , Yano H. , Imamura M. , Nakano Y. , Nakagaki T. , Ogata Y. , Terano T. , Miyamoto S. , Funatsu A. 
Published: March 2003

Background and Objectives An activated Factor VII (FVIIa) concentrate, prepared from human plasma on a large scale, has to date not been available for clinical use for haemophiliacs with antibodies against FVIII and FIX. In the present study, we attempted to establish a large‐scale manufacturing process to obtain plasma‐derived FVIIa concentrate with high recovery and safety, and to characterize its biochemical and biological properties.Materials and Methods FVII was purified from human cryoprecipitate‐poor plasma, by a combination of anion exchange and immunoaffinity chromatography, using Ca2+‐dependent anti‐FVII monoclonal antibody. To activate FVII, a FVII preparation that was nanofiltered using a Bemberg Microporous Membrane‐15 nm was partially converted to FVIIa by autoactivation on an anion‐exchange resin. The residual FVII in the FVII and FVIIa mixture was completely activated by further incubating the mixture in the presence of Ca2+ for 18 h at 10 °C, without any additional activators. For preparation of the FVIIa concentrate, after dialysis of FVIIa against 20 mm citrate, pH 6·9, containing 13 mm glycine and 240 mm NaCl, the FVIIa preparation was supplemented with 2·5% human albumin (which was first pasteurized at 60 °C for 10 h) and lyophilized in vials. To inactivate viruses contaminating the FVIIa concentrate, the lyophilized product was further heated at 65 °C for 96 h in a water bath.Results Total recovery of FVII from 15 000 l of plasma was ≈ 40%, and the FVII preparation was fully converted to FVIIa with trace amounts of degraded products (FVIIaβ and FVIIaγ). The specific activity of the FVIIa was ≈ 40 U/µg. Furthermore, virus‐spiking tests demonstrated that immunoaffinity chromatography, nanofiltration and dry‐heating effectively removed and inactivated the spiked viruses in the FVIIa. These results indicated that the FVIIa concentrate had both high specific activity and safety.Conclusions We established a large‐scale manufacturing process of human plasma‐derived FVIIa concentrate with a high yield, making it possible to provide sufficient FVIIa concentrate for use in haemophiliacs with inhibitory antibodies.
Craniofacial morphology and dental age in children with Silver–Russell syndrome
Authors: Bergman A , Kjellberg H , Dahlgren J 
Published: March 2003

Structured Abstract
Authors –
Bergman A, Kjellberg H, Dahlgren J.
Objectives –
This investigation is a part of a multidisciplinary descriptive evaluation of the Silver–Russell syndrome (SRS). The aim of this study was to describe the craniofacial morphology, occlusion and dental age in children with the SRS.
Design –
A descriptive literature‐controlled study.
Setting and Sample Population –
Sixteen children diagnosed as having SRS, 10 boys and six girls, aged 4.4–14.5 years, were referred from different parts of Sweden to the Queen Silvia Children's Hospital, Göteborg University.
Experimental Variable –
Facial morphology was measured on lateral and postero‐anterior radiographs. Occlusion, tooth eruption and palatal height were measured on casts, and dental maturity was evaluated on orthopantomograms.
Outcome Measure –
Linear and angular measurements were obtained from lateral radiographs and the ratios of the linear measurements from the postero‐anterior radiographs. The degree of tooth calcification shown on orthopantomograms was taken as a measure of dental maturity. Biometric measurements were taken and the degree of tooth eruption was recorded from the dental casts. The SRS children were compared with reference groups with t‐test and z‐scores.
Results –
Overall, SRS children were found to have smaller linear facial dimensions and deviations in the facial proportions, such as a small retropositioned, and steeply inclined maxilla and mandible, and a proportionally larger anterior facial height in relation to the posterior facial height. In 40% of them a smaller facial height or length on one side (facial asymmetry) was correlated to the smaller side of the body. The frequency of malocclusions was higher, and the palatal height showed a tendency towards an increase. Dental maturity was within normal limits, while the time of tooth eruption was slightly delayed.
Conclusions –
The deviating facial morphology described above is a part of the syndrome, which is characterized by short stature, growth hormone deficiency and asymmetries of the body. The higher percentage of malocclusions in the SRS children might lead to a greater need of orthodontic treatment.
Body conditions scores of dairy cattle in organic farms
Authors: Trachsel P. , Busato A. , Blum J. W. 
Published: March 2003

SummaryDairy cows on organic farms may not be fed adequately because provision of concentrates (and thus energy and protein), minerals and vitamins is limited. The hypothesis was therefore tested that the nutritional status of dairy cows in organic dairy production is insufficient. The nutritional status was characterized by determination of body conditions scores (BCS) in 152 farms, which were a stratified sample of Swiss organic farms. In summer (July – September 1997) and the ensuing winter (January – March 1998) the BCS was evaluated in 1687 and 1867 dairy cows, respectively. Mean number of cows per farm was 12.3, 13.7% of farms were located in mountain zones and 26% in lowlands, and 26% of farms kept part or all of their herds on alpine pastures during summer. Average 305‐day milk yield was 5467 kg per lactation. Depending on breed, this was 5–12% less than the contemporary average annual milk yield of cows registered in herd books. Average milk protein and fat contents were lower than that of cows kept on conventional farms. Mean milk urea concentration was 3.2 mmol/l in summer and only 2.0 mmol/l in winter, indicating insufficient protein supply in winter. BCS were between 3.0 and 3.75 for 69% of the cows, and < 2 and > 4 for 3 and 4% of cows, respectively. Effects on BCS of cow characteristics (days post‐partum, age and breed) and effects of farm characteristics with emphasis on feeding procedures were assessed with linear models. Days post‐partum, breed and several farm level variables had a significant influence on BCS. In conclusion, most dairy cows on organic farms had opitimal BCS and thus an adequate nutritional status. However nutritional energy and/or protein deficits were apparent during the winter feeding period
Factors affecting ascorbic acid (AsA) biosynthesis in chickens. II. Effect of dietary AsA and strain of chicken
Authors: Hooper C. L. , Maurice D. V. , Lightsey S. F. , Toler J. E. 
Published: March 2003

SummaryThe present study examined the effect of supplemental ascorbic acid (AsA) and ascertained if genotype is a determinant of biosynthesis and the response of strains to dietary AsA. Slow‐ (Ottawa Meat Control; OMC) and fast‐growing (Peterson Enhanced × Hubbard; PEH) chicks were fed 1000 mg/kg AsA from 1 to 10 weeks of age. The activity of l‐gulonolactone oxidase (GLO) was used to measure biosynthesis and estimated synthetic capacity (ESC) computed. Body weight was not affected by diets and relative kidney weight decreased with age. In 1 week, dietary AsA increased plasma AsA and inhibited GLO activity with a greater reduction in OMC birds. At 10 weeks, GLO activity was depressed almost uniformly in both strains. Strain by age and diet by age interactions were detected for GLO activity and ESC with significantly greater decline in PEH birds and birds fed supplemental AsA. The results demonstrated that dietary AsA inhibited biosynthesis in meat type chickens and the response at 10 weeks was not influenced by growth rate; and the age dependent decline in biosynthesis was more pronounced in the commercial PEH birds. The result suggests that such strains may be compromised in some situations. Research using multiple dietary levels of AsA, commercial strains, and defined stressors is warranted.
Survival of Botrytis cinerea in Soil in South‐Eastern Spain
Authors: Moyano C. , Melgarejo P. 
Published: March 2003

AbstractThe survival of Botrytis cinerea in sterile and unsterile soil at different temperatures and relative air humidities was investigated in south‐eastern Spain. Conidia survived only 7 days at 40∘C but, depending on relative humidity, for 30–90 days at 22∘C. High air humidity (95%) was needed to maintain soil humidity (8%) at a level that favoured conidial survival. Conidia survived better in sterile soil than in unsterile soil, probably because of the presence in the latter of soil microorganisms antagonistic to B. cinerea. Survival of conidia in environmental conditions simulating those in a greenhouse was less than 28 days. Results showed that B. cinerea conidia cannot survive over summer in south‐eastern Spain, and other primary sources of inocula are discussed.
Polyamine Metabolism in an Incompatible Interaction between Barley and the Powdery Mildew Fungus, Blumeria graminis f. sp. hordei
Authors: Cowley T. , Walters D. R. 
Published: March 2003

AbstractIn the incompatible interaction between the barley cultivar Hart (mlo allele) and the powdery mildew fungus Blumeria graminis DC. Speer f. sp. hordei Marchal, free spermidine and conjugated forms of putrescine and spermidine were found to accumulate 1–3 days following inoculation. The increase in free spermidine could be accounted for by increased activities of the biosynthetic enzymes ornithine decarboxylase (EC 4.1.1.17) and S‐adenosylmethionine decarboxylase (EC 4.1.1.50). Activities of the transferase enzymes putrescine hydroxycinnamoyl transferase (EC 2.3.1.‐) and tyramine feruloyl‐CoA transferase (EC 2.3.1.‐) were also increased in leaves of Hart inoculated with powdery mildew, as were activities of the polyamine catabolic enzymes diamine oxidase (DAO, EC 1.4.3.6) and polyamine oxidase (PAO, EC 1.4.3.4). The possible role of conjugated polyamines, and increases in DAO and PAO, in penetration based resistance to powdery mildew infection is discussed.