bluuebunny/crossref_metadata_2025 huggingface dataset:
Natural selection on the genetical component of variance in body condition in a wild bird population
Authors: Merilä J. , Kruuk L. E. B. , Sheldon B. C.
Published: March 2003

Although there is substantial evidence that skeletal measures of body size are heritable in wild animal populations, it is frequently assumed that the nonskeletal component of body weight (or ‘condition’) is determined primarily by environmental factors, in particular nutritional state. We tested this assumption by quantifying the genetic and environmental components of variance in fledgling body condition index (=relative body weight) in a natural population of collared flycatchers (Ficedula albicollis), and compared the strength of natural selection on individual breeding values with that on phenotypic values. A mixed model analysis of the components of variance, based on an ‘animal model’ and using 18 years of data on 17 717 nestlings, revealed a significant additive genetic component of variance in body condition, which corresponded to a narrow sense heritability (h2) of 0.30 (SE=0.03). Nongenetic contributions to variation in body condition were large, but there was no evidence of dominance variance nor of contributions from early maternal or common environment effects (pre-manipulation environment) in condition at fledging. Comparison of pre- and post-selection samples revealed virtually identical h2 of body condition index, despite the fact that there was a significant decrease (35%) in the levels of additive genetic variance from fledging to breeding. The similar h2 in the two samples occurred because the environmental component of variance was also reduced by selection, suggesting that natural selection was acting on both genotypic and environmental variation. The effects of selection on genetic variance were confirmed by calculation of the selection differentials for both phenotypic values and best linear unbiased predictor (BLUP) estimates of breeding values: there was positive directional selection on condition index both at the phenotypic and the genotypic level. The significant h2 of body condition index is consistent with data from human and rodent populations showing significant additive genetic variance in relative body mass and adiposity, but contrasts with the common assumption in ecology that body condition reflects an individual’s nongenetic nutritional state. Furthermore, the substantial reduction in the additive genetic component of variance in body condition index suggests that selection on environmental deviations cannot alone explain the maintenance of additive genetic variation in heritable traits, but that other mechanisms are needed to explain the moderate to high heritabilities of traits under consistent and strong directional selection.
Evolution of sexual size dimorphism in birds: test of hypotheses using blue tits in contrasted Mediterranean habitats
Authors: Blondel J. , Perret P. , Anstett M.-C. , Thébaud C.
Published: March 2003

Many hypotheses, either sex-related or environment-related, have been proposed to explain sexual size dimorphism in birds. Two populations of blue tits provide an interesting case study for testing these hypotheses because they live in contrasting environments in continental France and in Corsica and exhibit different degree of sexual size dimorphism. Contrary to several predictions, the insular population is less dimorphic than the continental one but neither the sexual selection hypothesis nor the niche variation hypothesis explain the observed patterns. In the mainland population it is advantageous for both sexes to be large, and males are larger than females. In Corsica, however, reproductive success was greater for pairs in which the male was relatively small, i.e. pairs in which sexual size dimorphism is reduced. The most likely explanation is that interpopulation differences in sexual size dimorphism are determined not by sex-related factors, but by differences in sex-specific reproductive roles and responses to environmental factors. Because of environmental stress on the island as a result of food shortage and high parasite infestations, the share of parents in caring for young favours small size in males so that a reduced sexual size dimorphism is not the target of selection but a by-product of mechanisms that operate at the level of individual sexes.
Caucasus Mountains divide postulated postglacial colonization routes in the white-breasted hedgehog, Erinaceus concolor
Authors: Seddon J. M. , Santucci F. , Reeve N. , Hewitt G. M.
Published: March 2003

For many European species, the mountains of the Alps and the Pyrenees have acted as significant barriers to northwards colonization from southern glacial refugia. To the east, the Caucasus Mountains would seem to have been a similar barrier to the white-breasted hedgehog (Erinaceus concolor). A deep divergence among hedgehog mitochondrial sequences to the north and south of the Caucasus Mountains suggests two colonization routes, originating from separate refugial regions and divided by this mountain barrier. From a Balkan refugium, hedgehogs have colonized northwards into Russia and to the northern foothills of the Caucasus Mountains. The origins of hedgehogs colonizing the southern parts of the Caucasus are not entirely clear, although fossil and climatic data suggest a glacial refugium on the southern shores of the Black Sea. Divergence within the southern group indicates a long-standing fragmentation within such a refugium or the presence of further cryptic refugia in Turkey and the Near East. The Caucasus barrier would seem to have been an important factor in structuring the late Pleistocene distribution of species.
Qualitative population divergence in proximate determination of a sexually selected trait in the collared flycatcher
Authors: Hegyi G. , Török J. , Tóth L.
Published: March 2003

We examined proximate determination of sexually selected forehead patch size in a Central-European population of Ficedula albicollis, the collared flycatcher, using a 9-year database, and compared our results with those obtained in other populations of the same and the sister species. Between-individual variation of forehead patch size was large, its repeatability larger than, and heritability similar to the Swedish population. Unlike in the other populations, the trait proved unaffected by body condition, and only very slightly influenced by age. There was no relationship between forehead patch size and breeding lifespan, and a marginal negative association with survivorship in adult males. Our results suggest that additive genetic variance of the trait in this population is large, but genes act independently of body condition, and there is no viability indicator value of the trait. This is the first report of a qualitative intraspecific difference in proximate determination of a sexually selected trait.
Closing of the Tethys Sea and the phylogeny of Eurasian killifishes (Cyprinodontiformes: Cyprinodontidae)
Authors: Hrbek T. , Meyer A.
Published: March 2003

To test vicariant speciation hypotheses derived from geological evidence of the closing of the Tethys Sea, we reconstruct phylogenetic relationships of the predominantly fresh-water killifish genus Aphanius using 3263 aligned base pairs of mitochondrial DNA from samples representing 49 populations of 13 species. We use additional 11 cyprinodontid species as outgroup taxa. Genes analysed include those encoding the partial 12S and 16S ribosomal RNAs; transfer RNAs for valine, leucine, isoleucine, glutamine, methionine, tryptophan, alanine, asparagine, cysteine and tyrosine; and complete nicotinamide adenine dinucleotide dehydrogenase subunit I and II. Molecular substitution rate for this DNA region is estimated at of 8.6 ± 0.1 × 10−9 substitutions base pair−1 year−1, and is derived from a well dated transgression of the Red Sea into the Wadi Sirhan of Jordan 13 million years ago; an alternate substitution rate of 1.1 ± 0.2 × 10−8 substitutions base pair−1 year−1 is estimated from fossil evidence. Aphanius forms two major clades which correspond to the former eastern and western Tethys Sea. Within the eastern clade Oligocene divergence into a fresh-water clade inhabiting the Arabian Peninsula and an euhaline clade inhabiting coastal area from Pakistan to Somalia is observed. Within the western Tethys Sea clade we observe a middle Oligocene divergence into Iberian Peninsula and Atlas Mountains, and Turkey and Iran sections. Within Turkey we observe a large amount of genetic differentiation correlated with late Miocene orogenic events. Based on concordance of patterns of phylogenetic relationships and area relationships derived from geological and fossil data, as well as temporal congruence of these patterns, we support a predominantly vicariant-based speciation hypothesis for the genus Aphanius. An exception to this pattern forms the main clade of A. fasciatus, an euhaline circum-Mediterranean species, which shows little genetic differentiation or population structuring, thus providing no support for the hypothesis of vicariant differentiation associated with the Messinian Salinity Crisis. The two phylogenetically deepest events were also likely driven by ecological changes associated with the closing of the Tethys Sea.
Risk behaviour among blood donors who give blood in order to be tested for the human immunodeficiency virus
Authors: Stigum H. , Bosnes V. , Magnus P. , Ørjasæter H.
Published: March 2003

Background and Objectives

There has been concern that some individuals may donate blood primarily motivated by the easy access to human immunodeficiency virus (HIV) testing, and that such donors may represent a risk to the transfusion service. In this article we focus on the risk behaviour of donors who reported that they gave blood in order to be HIV tested.

Materials and Methods

Anonymous questionnaires were given to 5859 blood donors. The response rate was 70%.

Results

Of the responders, 2·8% reported to have donated blood in order to be HIV tested. However, 87% of the donation‐for‐test group did not have any identified risk behaviour.

Conclusions

The proportion who donated blood in order to be HIV tested was higher than expected, but the majority of the group did not have any identifiable HIV risk.
Tetanus antibody levels of female volunteers after injection with solvent/detergent‐treated human tetanus immunoglobulin (Tetabulin S/D)
Authors: Wahlberg T. , Leibl H. , Brauner A. , Kirgios M. , Adner N.
Published: March 2003

Background and Objectives

The aim of this study was to analyse the increase of anti‐tetanus titre in volunteers following injection with human tetanus immunoglobulin (HTI).

Materials and Methods

Twelve females with tetanus antibody titres of ≤ 0·05 international units (IU)/ml were injected with 500 IU of human tetanus immunoglobulin (Tetabulin S/D). The tetanus antibody titres were determined before injection, and after 30 h, 48 h and 4 days.

Results

A fast and sustained increase of protective tetanus antibody levels was observed in 10 of 12 volunteers. No adverse events related to the study drug were reported.

Conclusions

HTI confers rapid and effective immunity to tetanus.
Primary refractoriness to platelet transfusion caused by Naka antibody alone
Authors: Fujino H. , Ohta K. , Taniue A. , Nagao N. , Hino M. , Yamane T. , Koh K.‐R. , Takeoka Y. , Hirose A. , Aoyama Y. , Nakamae H. , Terada Y. , Takubo T. , Tatsumi N.
Published: March 2003

Background and Objectives

Anti‐Naka, a platelet‐specific antibody, occasionally causes platelet‐transfusion refractoriness (PTR) together with human leucocyte antigen (HLA) antibodies. Anti‐Naka usually appears after frequent platelet transfusions or pregnancy. We report the first case of PTR caused by anti‐Naka alone.

Materials and Methods

A 19‐year‐old male patient with testicular tumour showed PTR when receiving his first transfusion of platelets. Screening for platelet antigens and platelet antibodies revealed that he had type I CD36 (Naka) deficiency and that anti‐Naka, but not anti‐HLA, was present before he received his first transfusion.

Results

The transfusion of Naka‐negative, but HLA non‐selected, platelets was effective in raising the platelet count.

Conclusion

Clinically significant Naka antibody was present as naturally occurring antibody in a platelet glycoprotein IV (CD36)‐negative non‐transfused male patient.
Altered intracellular purine nucleotides in gamma‐irradiated red blood cell concentrates
Authors: Leitner G. C. , Neuhauser M. , Weigel G. , Kurze S. , Fischer M. B. , Höcker P.
Published: March 2003

Background and Objectives

Gamma irradiation at a dose of 30 Gy induces deterioration of erythrocytes, resulting in storage lesions that significantly shorten the shelf‐life of packed red cell concentrates (RCCs). The aim of the present study was to investigate the effect of gamma irradiation on intracellular purine nucleotides of red blood cells during storage.

Materials and Methods

Three‐day‐old leucocyte‐depleted saline–adenine–glucose–mannitol (SAGM)‐preserved RCCs, obtained from the Blood Service of the Austrian Red Cross, were gamma irradiated with 30 Gy. Samples were taken on days 1, 2, 3 and 7 after irradiation and subsequently at weekly intervals up to the end the of shelf‐life (day 39 after irradiation) and were investigated for the K+ and Na+ content in the supernatant, for intracellular concentrations of ATP, ADP, ITP, IDP, GTP and GDP of erythrocytes, and for haemolysis.

Results

Within the first 24 h after gamma irradiation, no metabolic or biochemical changes were detectable in the RCCs. The K+ concentration in the supernatant increased after 24 h, while the Na+ concentration decreased in irradiated units and this ion disequilibrium persisted until the end of the shelf‐life. After an initial increase of intracellular ATP, ADP and GTP during the first week of storage, the intracellular concentrations of ATP, ADP, GTP and ITP decreased, while IDP increased. The decrease of ATP and ADP was found to be more pronounced in irradiated units. At the end of the shelf‐life, the ATP, GTP and ITP concentrations of irradiated RCCs had decreased to < 10% of the initial level and the critical threshold of 0·8% haemolysis was reached.

Conclusion

Gamma irradiation of SAGM‐preserved RCCs leads to serious deterioration of the purine nucleotide metabolism of erythrocytes during storage, which can reduce the in vivo recovery of the transfused red cells.
Microbial contamination of cord blood stem cells
Authors: Honohan Á. , Olthuis H. , Bernards A. T. , Van Beckhoven J. M. , Brand A.
Published: March 2003

Background and Objectives After storage, low levels of contaminating bacteria in standard blood components can reach bacteraemic levels, causing severe transfusion‐associated sepsis. For cord blood (CB), the significance of low levels of contaminating bacteria and the optimal detection method is unknown and not supported by available guidelines.

Materials and Methods Spiking experiments and testing of various subfractions of CB units were used to determine the behaviour of bacteria during centrifugation, freezing and thawing. For routine testing of CB, different volumes were compared for the detection of potential pathogens and micro‐organisms of low pathogenicity.

Results Centrifugation, as applied to CB fractionation, does not show concentration of bacteria in any particular fraction and supports the possibility of culture of waste fractions. Dimethylsulphoxide (DMSO) and freezing does not affect the viability of bacteria under the conditions used in this study. Owing to the low contamination level, a large sample volume of 20 ml was more sensitive than a 10‐ml sample volume. Eighty five per cent of the isolated strains can be considered to be of low pathogenicity.

Conclusion When an optimal waste fraction sample volume of 20 ml was cultured, the contamination rate of CB was found to be ≈ 13%, with low levels of < 1 colony‐forming unit (CFU)/ml. Such levels of bacteria of low pathogenicity are expected to be of clinical importance only when CB is expanded in vitro for a prolonged period of time.
A direct comparison of the antigen‐specific antibody profiles of intravenous immunoglobulins derived from US and UK donor plasma
Authors: Matejtschuk P. , Chidwick K. , Prince A. , More J. E. , Goldblatt D.
Published: March 2003

Background and Objectives Intravenous immunoglobulin (IVIG) is used in a range of immunodeficiency states that require a broad spectrum of protective antibodies to a range of common pathogens. A comparison of the antigen‐specific antibody profile of preparations of an IVIG (Vigam®) derived from US and UK sourced plasma was performed, and these preparations were also compared with three other IVIG products from different manufacturers.

Materials and Methods Antibodies against a range of bacterial and viral pathogens were measured by immunoassay.

Results Similar profiles were found for Vigam® made from UK and US source plasma and also for the other three IVIGs tested, but some specific differences were observed.

Conclusions IVIG preparations have a similar therapeutic spectrum of antibodies when prepared from plasma sourced either from the UK or the US.
Diversion of first blood volume results in a reduction of bacterial contamination for whole‐blood collections
Authors: De Korte D. , Marcelis J. H. , Verhoeven A. J. , Soeterboek A. M.
Published: March 2003

Background and Objectives In a previous study we established a reliable setpoint for the prevalence of bacteria in whole blood. In the present study we investigated the possible preventive effect, of diversion of the first 10 ml of a blood donation, on the bacterial contamination rate.

Materials and Methods To divert the first 10 ml of a whole‐blood donation, we used a special five‐bag system equipped with a Composampler® device. After venepuncture, the first 10 ml of a donation was sampled into a vacutainer tube. This was followed by the collection of the whole‐blood unit. The extra bag allowed direct sampling of the final donation in a closed system for BacT/Alert. Whole‐blood samples were taken after storage (2–14 h at 20 °C) and subsequent mixing. BacT/Alert culture bottles were incubated until positive, or for 7 days if negative. Confirmation and identification of positive cultures was performed according to internationally recognized standard reference methods.

Results The prevalence of bacteria in whole blood, as determined by using standard collection techniques, was 0·35% (95% confidence interval 0·27–0·44%, n = 18 257). After diversion of the first 10 ml this value was significantly lower: 0·21% (P < 0·05, 95% confidence interval 0·12–0·35%, n = 7087). Most strikingly, a reduction in the frequency of staphylococcal species was observed (P < 0·02, reduction from 0·14 to 0·03%).

Conclusions Diversion of the first 10 ml of blood was shown to contribute significantly to a reduction in the prevalence of superficial skin bacteria in whole‐blood units. In our opinion, blood collection systems should be adapted to use the first 10–30 ml of a whole‐blood donation for testing purposes.
Which groups of patients are transfused? A study of red cell usage in London and southeast England
Authors: Stanworth S. J. , Cockburn H. A. C. , Boralessa H. , Contreras M.
Published: March 2003

Background and Objectives There are few published data on the use of red blood cells (RBC) by specialty in the United Kingdom. The aim of this survey was to identify major specialty users of blood to target for audit of transfusion practice with a view to minimizing inappropriate use and to support planning of blood supply needs for the future.

Materials and Methods Data were collected retrospectively of RBC units transfused at 62 hospitals/trusts in London and southeast England between April 1997 and March 1998.

Results  A total of 594 810 transfused RBC units were successfully traced to their respective clinical specialties, representing 91·9% of all RBC units issued to the study hospitals. Of the RBC units transfused, 51·2% were transfused in surgical, 36·0% in medical and 12·8% in ‘combined’ specialties.

Conclusions This large study has accurately documented the clinical disciplines that are significant users of RBCs in our service area. It has heightened general understanding of RBC usage within hospitals. It has also raised questions on future strategies for reducing allogeneic blood transfusion that will be important if anticipated major reductions in blood supply occur in the near future.
Hepatitis C virus–polymerase chain reaction minipool testing: 3 years in the largest Swiss blood transfusion service
Authors: Stolz M. , Gilgen M. , Niederhauser C.
Published: March 2003

Background and Objectives Hepatitis C virus–polymerase chain reaction (HCV–PCR) minipool testing can improve the safety of labile blood products owing to a reduction in the diagnostic preseroconversion window period. In Switzerland, HCV–PCR minipool testing for the release of labile blood components became mandatory in September 1999. In the largest Swiss blood transfusion centre, HCV–PCR minipool testing began in January 1999. This report analyses the performance of the test during a 3‐year period: 1 January 1999 to 31 December 2001.

Materials and Methods EDTA‐blood was collected in either standard tubes or plasma preparation (PPT) tubes from 10 blood transfusion services in Switzerland and then sent to the Blood Transfusion Service SRC Berne. Up to 48 donor samples were pooled overnight using Tecan Genesis RSP 200/8 pipettors. Viral RNA was extracted by using the Qiagen QIAamp 96 viral RNA BioRobot kit on a BioRobot 9604. For PCR amplification and detection of HCV or internal control (IC) sequences, the Roche Cobas Amplicor v2·0 test kit was used. Data management, pool resolution and identification of positive samples were performed using the PMS Software from Tecan.

Results In the 3‐year period from 1 January 1999 to 31 December 2001, 839 056 blood donor samples were tested in minipools of up to 48 samples. Thirty‐five HCV–PCR‐positive donations were identified. Thirty‐four samples had antibodies against HCV and were therefore also detected by screening for antibody to HCV (anti‐HCV). In October 2001, one seronegative (but PCR‐positive) donor was detected.

Conclusions HCV–PCR minipool testing was successfully introduced in the largest Swiss blood transfusion service. It was shown that the release of HCV–PCR minipool results can be accomplished concurrently with the results of serological analysis. The challenge with a seronegative, but PCR‐positive, donor demonstrates that the minipool testing strategy adds additional safety to blood products.
Wirksamkeit und Sicherheit von Tacalcitol‐Salbe in der Langzeitanwendung bei chronischer Plaque Psoriasis
Authors: Van De Kerkhof P. C. M. , Berth‐Jones J. , Griffiths C. E .M. , Harrison P. V. , Hönigsmann H. , Marks R. , Roelandts R. , Schöpf E. , Trompke C.
Published: March 2003

Zusammenfassung: Da Psoriasis‐Patienten häufig eine Dauertherapie benötigen, muss eine optimale Behandlung Langzeitwirksamkeit mit einem guten Sicherheitsprofil vereinen. Das Ziel der vorliegenden, multizentrischen Studie war die Beurteilung der Wirksamkeit, Sicherheit und Verträglichkeit von Tacalcitol (4 µg/g) Salbe, bei einmal täglicher Anwendung über einen Zeitraum von 18 Monaten.

 Die Beurteilung der Wirksamkeit erfolgte über den PASI (Psoriasis Area and Severity Index) auf Grundlage der Summenscores von Rötung, Infiltration und Schuppung, sowie das Ausmaß der betroffenen Körperoberfläche (KOF). Zur Beurteilung der Sicherheit wurden die Serumwerte von Calcium, Parathormon, Calcitonin, 1,25‐dihydroxy Vitamin‐D3 (Calcitriol), sowie Urin‐Calcium, Urin‐Creatinin, Calcium/Creatinin Verhältnis und α1‐Microglobulin im 24‐Stunden‐Urin gemessen. Im ersten Teil der Studie über drei Monate sind 304 Patienten mit chronischer Plaque Psoriasis behandelt worden, die eine betroffene Körperoberfläche von 7 – 20 % aufwiesen. 257 Patienten beendeten die erste Behandlungsphase. Davon nahmen 197 Patienten an der zweiten Behandlungsphase über 15 Monate teil.  Die Tacalcitol‐Therapie reduzierte erfolgreich den Schweregrad der Psoriasis und die Wirksamkeit blieb über den gesamten Studienzeitraum erhalten. Nach dreimonatiger Therapie reduzierte sich der PASI von 9,5 auf 4,6 und betrug am Studienende nach 18 Monaten 3,25 (p < 0,0001). Gleichzeitig verringerte sich der Anteil der betroffenen Körperoberfläche um 30 % nach drei Monaten und um 50 % zum Studienende. Es traten keine Hypercalcämien auf. Die Serumspiegel von Calcium, Parathormon und Calcitriol und die Laborbefunde des 24‐Stunden‐Urins zeigten keine signifikanten Veränderungen. Die Studie ergab keine Korrelation zwischen den Serum‐ oder Urinspiegeln von Calcium und der verwendeten Menge an Tacalcitol‐Salbe, auch nicht bei Patienten mit großem Salbenverbrauch (bis zu 13 g/pro Tag und bis zu 20 % KOF). Die Behandlung war sehr gut verträglich. Es traten keine schweren oder unerwarteten Nebenwirkungen auf. Ein Abbruch der Behandlung aufgrund von Hautirritationen wurde bei 5,9 % der Patienten gesehen. Reversible lokale Hautirritationen traten meist zu Anfang der Behandlung auf, reduzierten sich aber deutlich im weiteren Therapieverlauf. Die Ergebnisse dieser Studie zeigen deutlich, dass die Tacalcitol Langzeittherapie mit einmal täglicher Anwendung, eine wirksame, sichere und gut verträgliche Therapieoption bei chronischer Plaque Psoriasis darstellt.
Effects of Stem‐Injected Plant Growth Regulators, with or without Sucrose, on Grain Production, Biomass and Photosynthetic Activity of Field‐Grown Corn Plants
Authors: Zhou X. M. , MacKenzie A. F. , Madramootoo C. A. , Smith D. L.
Published: March 2003

Study of plant growth regulators (PGRs) through conventional foliar application or tissue culture or other organic materials has limitations. No previous study has examined the effects of long‐term continuous addition of PGRs, with or without sucrose, to field‐grown corn (Zea mays L.) plants. A field study was conducted to determine the effects on corn plant growth and productivity during the grain‐filling period of a continuous supply of PGRs, with or without sucrose, using a recently developed injection technique to deliver pressurized solutions through syringe needles sealed to the stem with latex. Our four PGRs (IAA, ABA, ethephon and salicylic acid) and a distilled water control, and two levels of sucrose (150 g l−1 and a distilled water control) were injected into corn plants for 42 consecutive days during the grain‐filling period. The plants injected with solutions not containing sucrose took up 42 ml more than those injected with sucrose‐containing solutions. Corn plants injected with salicylic acid (SA) produced 9 % more grain yield than plants injected with no PGRs. The combination of SA and sucrose increased the photosynthetic rate by 42 % when compared with distilled water. Injection of ethephon resulted in an 11 % reduction in grain yield. Neither IAA nor ABA altered plant photosynthesis or productivity. Sucrose injection increased the dry weight of injected internodes and stover, and induced partial stomatal closure, although without any measurable effect on net photosynthetic rate. This study showed that stem injection makes possible the study of changes in plant physiology during grain‐filling due to the effects of PGRs and metabolites administered continuously over protracted periods of time. It also demonstrated a previously undocumented stimulation of plant photosynthesis and grain yield by SA.
Effects of Nitrogen and Foliar Sulphur Interaction on Grain Yield and Yield Components in Barley
Authors: Del Moral L. F. García , De La Morena I. , Ramos J. M.
Published: March 2003

In this study, conducted from 1979 to 1986 in southern Spain, the objective was to analyze the effects of a possible interaction between soil‐applied N and foliar S applied to barley (Hordeum vulgare L.) during tillering on grain yield and to identify the mechanism involved. From 1979 to 1982, we used rates of 20, 40, 60 and 80 kg a.i. N ha−1, together with 12.5 or 25 kg foliar a.i. S ha−1 during tillering. The results demonstrated that foliar S at both dosages acted as a partial (but not total) substitute for N, when the latter was applied at levels of 40 to 60 kg ha−1. These effects of S did not appear to result only from a nutritive mechanism, but rather from a hormonal mechanism through the increase in ethylene biosynthesis. Therefore, during 1983 to 1986, we used 40, 60 and 80 kg a. i. N ha−1, together with 12.5 a. i. S ha−1 and 0.55 kg a.i. ethrel (2‐chloroethyl‐phosphonic acid) ha−1. The results showed that the effects of S and ethrel on yield were practically the same. Assayed with 40 and 60 kg N ha−1, S and ethrel acted as partial (but not total) substitutes for N, exceeding the yield of the control without S or ethrel, and equalling the yield obtained with 20 kg more of N ha−1. The S or ethrel applied with 80 kg N ha−1 presented an additive effect with the N. The increases in yield using S or ethrel were in all cases due to the increased final number of spikes m−2, which was principally a consequence of the higher number of tillers formed but also a result of increased survival of tillers to form a viable spike. In addition, the positive effects of S on yield were greater the smaller the N dosage and the lower the annual yield. Finally, we present a possible mechanism of hormonal action, to explain how foliar S applied during tillering affects grain yield in barley.
Organic Recycling for Soil Quality Conservation in a Sub‐tropical Plateau Region
Authors: Chakrabarti K. , Sarkar B. , Chakraborty A. , Banik P. , Bagchi D. K.
Published: March 2003

The long‐term effect of organic recycling on some aspects of quality in a lowland rice soil of an Indian plateau region was studied. The experiment was set up at the agricultural experimental farm of the Indian Statistical Institute, Giridih, Bihar, India. Two rice cultivars, and treatments with four organic supplements (cowdung manure, Leuceana leaves, decomposed farm residue and Sesbania), chemical fertilizers (urea, superphosphate and muriate of potash) and no input were arranged in a factorial randomized block design. Organic supplements improved soil quality parameters such as water holding capacity, total organic C, microbial biomass C, urease and acid phosphatase activities of soils in comparison to chemical fertilizers and no input. Among the organic supplements, cowdung manure gave significantly higher organic C (1.39%), microbial biomass C (276.46 μg g−1 dry soil), urease activity (32.79 and 21.22 μg urea hydrolized g−1 dry soil h−1 at 37 °C by the buffer and non‐buffer method, respectively) and acid phosphatase activity (1.99 μmol p‐nitrophenol released g−1 dry soil h−1 at 37 °C) than the others. The conversion of organic C into biomass C (2.46%) was highest in Leuceana‐treated soil.
Dynamics of Growth and Water Relations of Fodderbeet and Seabeet in Response to Salinity
Authors: Niazi B. H. , Rozema J. , Broekman R. A. , Salim M.
Published: March 2003

A pot experiment was conducted under greenhouse conditions with two subspecies of beet, fodderbeet (Beta vulgaris cv. Majoral) and seabeet (Beta maritima), under saline conditions. Growth and physiological parameters (dry weight, leaf area, water relations and net photosynthesis) were recorded. The two subspecies responded differently in terms of growth parameters. Plant growth was significantly reduced at 400 m
m NaCl, while no significant growth reduction occurred at 200 m
m NaCl. Fairly high values of relative growth rate were associated with the leaf area of the cultivars. The water content of the shoot decreased with plant age. The fodderbeet cultivar Majoral showed a significant increase in dry matter at 200 m
m NaCl after 5 weeks. This growth improvement may be related to the better adaptation of the plants under saline conditions.
Nitrogen Fixation in Hybrids of White Clover (Trifolium repens L.) and Caucasian Clover (Trifolium ambiguum M. Bieb)
Authors: Abberton M. T. , MacDuff J. H. , Vagg S. , Marshall A. H. , Michaelson‐Yeates T. P. T.
Published: March 2003

Hybrids between white clover (Trifolium repens L.) and Caucasian clover (or Kura clover, Trifolium ambiguum M. Bieb) are a potential route for the improvement of drought tolerance and persistence in white clover. However, to be agronomically viable they must show no significant reduction in their potential for nitrogen fixation relative to white clover. A comparative study of growth rate and nitrogen fixation was carried out in flowing solution culture without a supply of mineral nitrogen to the plants. The two parental species and two generations of backcross hybrids, with white clover as the recurrent parent, were assessed. The growth rate and N content of T. ambiguum were significantly lower than those of the other lines. However, dry matter production, nodule biomass per plant and rates of fixation were similar in second‐generation backcross plants and white clover. The results suggest that the agronomic potential of this novel germplasm is not compromised by limitations with respect to nitrogen fixation.
Effect of Three Tillage Systems on Weed Flora in a 3‐Year Rotation with Four Crops
Authors: Bilalis D. , Efthimiadis P. , Sidiras N.
Published: March 2003

Field experiments were conducted to determine the effect of tillage on the dry weight, frequency (PF), density (PD) and species composition of the weed population. Three tillage systems (CT: conventional tillage, MT: minimum tillage and NT: no tillage) were compared in a 3‐year rotation [wheat–vetch (green manure)–cotton–barley]. Decreases in PF, mean PD and number of species were observed under NT because in this system the soil remains undisturbed, and conditions are not suitable for seed germination. In contrast, annual weeds had a higher PF under the CT system, because they mainly propagate by seed and soil tillage creates more favourable growth conditions; thus they also had a higher PD. The highest PF and PD were found for the species Sinapis arvensis and Solanum nigrum. Perennial weeds had higher PD under the NT system, because their roots cannot be destroyed by soil tillage. The number of species was not altered in CT and MT, but was decreased in NT. In winter crops, annual species under CT and MT, and perennial species under NT were observed. In cotton crops, perennial species under CT and MT, and annual species under NT were observed. The mean PD of weed species in the first crop followed the sequence NT > MT > CT and in subsequent crops followed the reverse sequence CT > MT > NT.
Factor for Estimating Nitrogen Contribution of Cowpea as a Cover Crop
Authors: Aguiar J. L. , Williams W. A. , Graves W. L. , McGiffen M. , Samons J. V. , Ehlers J. D. , Matthews W. C.
Published: March 2003

The nitrogen contribution of cowpea [Vigna unguiculata (L.) Walp.] above‐ground biomass was estimated using the per cent nitrogen and per cent dry matter of 24 cowpea entries. Cowpea growth stage was assigned a maturity index, and an ‘N factor’ was calculated. Results for this species‐specific ‘N factor’ ranged from 12.5 at the vegetative stage to 13.5 at the reproductive stage. Using the ‘rule of 16’ as developed for sampling the fresh biomass of other legume cover crops, the amount of nitrogen contributed by cowpeas can be estimated by using an average ‘N factor’ of 13.
Effects of Soil Treatment with Iron, Manganese and Zinc on Growth and Micronutrient Uptake of Sunflower Plants Grown in High‐pH Soil
Authors: El‐Fouly M. M. , Nofal O. A. , Mobarak Z. M.
Published: March 2003

The purpose of this work was to study the effects of adding different concentrations of iron (Fe), manganese (Mn) and zinc (Zn) in irrigation water to high‐pH sandy soil on the growth and micronutrient uptake of sunflower plants (Helianthus annus L., cv. Giza 1). The experiment was carried out in Mitscherlish pots under greenhouse conditions. Low Fe, Mn and Zn concentrations were found to have a positive effect on the micronutrient contents of the plant organs. The number of leaves and the leaf area were increased by addition of Fe, Mn and Zn. Root size was increased by addition of Fe and Mn. Stem and root lengths were increased by Mn only. It could be concluded that continuous addition of Fe, Mn and Zn in irrigation water to high‐pH sandy soil deficient in these nutrients, where root growth was contained within a limited volume (in pots), led to increases in growth and micronutrient uptake (Fe, Mn and Zn). Further studies are needed to determine whether similar effects will be found under field conditions.
Direct and Residual Contributions of Symbiotic Nitrogen Fixation by Legumes to the Yield and Nitrogen Uptake of Maize (Zea mays L.) in the Nigerian Savannah
Authors: Pal U. R. , Shehu Y.
Published: March 2003

Field experiments were conducted to determine the direct and residual contributions of legumes to the yield and nitrogen (N) uptake of maize during the wet seasons of 1994 and 1995 at the University Farm, Abubakar Tafawa Balewa University, Bauchi, Nigeria, located in the Northern Guinea savannah of Nigeria. Nodulating soybean, lablab, green gram and black gram contributed to the yield and N uptake of maize either intercropped with the legumes or grown after legumes as a sole crop. Direct transfer of N from the nodulating soybean, lablab, green gram and black gram to the intercropped maize was 24.9–28.1, 23.8–29.2, 19.7–22.1 and 18.4–18.6 kg N ha–1, respectively. However, the transfer of residual N from these legumes to the succeeding maize crop was 18.4–20.0, 19.5–29.9, 12.0–13.7 and 9.3–10.3 kg N ha–1, respectively. Four years of continuous lablab cropping resulted in yields and N uptake of the succeeding maize crop grown without fertilizer N that were comparable to the yields and N uptake of the succeeding maize crop supplied with 40–45 kg N ha–1 and grown after 4 years of continuous sorghum cropping. It may therefore be concluded that nodulating soybean, lablab, green gram and black gram may be either intercropped or grown in rotation with cereals in order to economize the use of fertilizer N for maize production in the Nigerian savannah.
Chlorophyll Dynamics in Rice (Oryza sativa) Before and After Flowering Based on SPAD (Chlorophyll) Meter Monitoring and its Relation with Grain Yield
Authors: Ramesh K. , Chandrasekaran B. , Balasubramanian T. N. , Bangarusamy U. , Sivasamy R. , Sankaran N.
Published: March 2003

The rice plant at any point in time is composed of leaves of physiologically different ages, so it follows that the leaves differ in their contributions to the growth of the whole plant and its grain yield. As the leaf chlorophyll content (Soil Plant Analytical Division value) is the best indicator of photosynthetic activity in rice, the chlorophyll content of rice before and after flowering was determined in a weed management field experiment on direct wet seeded rice. The results indicated that the leaf chlorophyll content at 79 days after sowing correlated well with the grain yield of rice. Multiple regression models also indicated the dependence of rice yield on leaf chlorophyll content before and after flowering.
Strategies to Improve the Use Efficiency of Mineral Fertilizer Nitrogen Applied to Winter Wheat
Authors: Blankenau K. , Olfs H.‐W. , Kuhlmann H.
Published: March 2003

Recovery of fertilizer nitrogen (N) applied to winter wheat crops at tillering in spring is lower than that of N applied at later growth stages because of higher losses and immobilization of N. Two strategies to reduce early N losses and N immobilization and to increase N availability for winter wheat, which should result in an improved N use efficiency (= higher N uptake and/or increased yield per unit fertilizer N), were evaluated. First, 16 winter wheat trials (eight sites in each of 1996 and 1997) were conducted to investigate the effects of reduced and increased N application rates at tillering and stem elongation, respectively, on yield and N uptake of grain. In  treatment 90‐70‐60 (90 kg N ha−1 at tillering, 70 kg N ha−1 at stem elongation and 60 kg N ha−1 at ear emergence), the average values for grain yield and grain N removal were up to 3.1 and 5.0 % higher than in treatment 120‐40‐60, reflecting conventional fertilizer practice. Higher grain N removal for the treatment with reduced N rates at tillering, 90‐70‐60, was attributed to lower N immobilization (and N losses), which increased fertilizer N availability. Secondly, as microorganisms prefer NH4+ to NO3− for N immobilization, higher net N immobilization would be expected after application of the ammonium‐N form. In a pot experiment, net N immobilization was higher and dry matter yields and crop N contents at harvest were lower with ammonium (ammonium sulphate  +  nitrification inhibitor Dicyandiamide) than with nitrate (calcium nitrate) nutrition. Five field trials were then conducted to compare calcium nitrate (CN) and calcium ammonium nitrate (CAN) nutrition at tillering, followed by two CAN applications for both treatments. At harvest, crop N and grain yield were higher in the CN than in the CAN treatment at each N supply level. In conclusion, fertilizer N use efficiency in winter wheat can be improved if N availability to the crops is increased as a result of reduced N immobilization (and N losses) early in the growth period. N application systems could be modified towards strategies with lower N applications at tillering compensated by higher N dressing applications later. An additional advantage is expected to result from use of nitrate‐N fertilizers at tillering.
Study of the variability of the response to inbreeding for meat production in Merino sheep
Authors: Analla By M. , Montilla J. M. , Serradilla J. M.
Published: March 2003

Introduction

Inbreeding is known to affect metric traits. Reduction of additive genetic variance, as well as phenotypic values are its most significant deleterious effects. Yet the emergence of disorders due to recessive gene action constitutes another important aspect. Despite the fact that some effect of inbreeding can be positively used in selection schemes (T oro 1993), breeders are aware of the deleterious effects and try to avoid them. This is particularly true when the selection nucleus and the related population are of small size. Several authors (H
agger 1991; V
errier et al. 1993; W
ray and G
oddard 1994) have stressed that the application of sophisticated methods of selection, particularly BLUP‐based techniques (H
enderson 1973) is to be reconsidered in the light of inbreeding effects. Comparisons of selection methods should therefore account for inbreeding depression (T
oro and P
jrez‐E
nciso 1990; Q
uinton et al. 1992). Other authors believe that inbreeding depression is not so important, at least in the meat production industry (G
ama and S
mith 1993) for traits with high heritabilities. Nevertheless, the net effect of inbreeding in a selection programme will depend on the magnitude of the selection response relative to the depression due to the accumulated inbreeding. Depending on whether genetic gain and inbreeding depression compensate for each other, the level of inbreeding of the animals may need to be accounted for in the selection process (K
eller et al. 1989; R
oehe et al. 1993; K
lieve et al. 1994; B
risbane and G
ibson 1995). On the other hand, the response to inbreeding is not the same for all animals. There is an important range of variation for the estimates of inbreeding depression reported in the literature (e.g. L
amberson and T
homas 1984). Differences in such a response with respect to identifiable sources of variation should be examined. The objective of this work was to study the relationship between the depression due to inbreeding and litter size of ewes and weights of lambs; and to identify sources of a possible differential response to inbreeding between animals coming from different genetic line, sex, or type of birth.
A mating system to reduce inbreeding in selection programmes: Theoretical basis and modification of compensatory mating
Authors: Nomura T.
Published: March 2003

Introduction

Increased rate of inbreeding in selection programmes may have an important effect on mid‐ and long‐term selection response and reproductive performance through reduction in genetic variance and inbreeding depression. Selection on an inherited trait inflates the rate of inbreeding and reduces the effective population size (R obertson 1961; S
antiago and C
aballero 1995). This can be particularly important in selection based on index with information from relatives (L
ush 1947) or best liner unbiased prediction (BLUP) with an animal model (H
enderson 1984).

In recent years, various methods have been proposed to reduce the rates of inbreeding in selection programmes while keeping genetic gains at the same level. These methods assume various selection and mating strategies. G rundy et al. (1994) showed that the use of biased heritability estimates for BLUP evaluation is one of the simplest and most efficient methods. A direct reduction in the weight on family mean in index selection (T
oro and P
erez‐E
nciso 1990), selection for weighted ancestral Mendelian sampling estimates (W
oolliams and T
hompson 1994; G
rundy et al. 1998) and limited use of selected parents (T
oro and N
ieto 1984; W
ei 1995) have also been shown to be efficient methods.

Other methods include nonrandom matings of selected parents, such as factorial mating designs (W oolliams 1989), minimum coancestry mating (T
oro et al. 1988) and compensatory mating (S
antiago and C
aballero 1995). Simultaneous optimization of the selection of candidates and their mating allocations has been also considered through mate selection with linear programming techniques (T
oro and P
erez‐E
nciso 1990). Among these methods, compensatory mating is a very simple and efficient method (G
rundy et al. 1994; S
antiago and C
aballero 1995; C
aballero et al. 1996). This mating system was derived from the theoretical consideration on effective population size under selection (S
antiago and C
aballero 1995). Although S
antiago and C
aballero (1995) considered that implementation of this mating could counteract the cumulative effect of selection on the effective population size, the theoretical basis has been little studied.

In this paper, the author gives the theoretical basis of compensatory mating. A modification to enhance the effect of compensatory mating is also proposed and the efficiency is examined by stochastic simulation.
Evidence for quantitative trait locus for conformation traits on chromosome 19 in beef cattle
Authors: Napolitano  , Catillo  , Lucioli  , Carretta  , Di Giacomo  , Rossi  , Moioli
Published: March 2003

A total of 110 F1 crossbred individuals of Piemontese × Chianina cattle and 75 F2 intercross were genotyped for the DNA marker IDVGA‐46, composed of an (AC) repeat, that showed a polymorphism of three alleles: 205, 207 and 229 base pairs. Association of marker polymorphism to beef conformation measures was tested with a linear mixed model which included the fixed effect of the marker genotype separated according to the origin of the allele: whether inherited from Piemontese or from Chianina and random additive genetic effect of the animals. Carriers of allele 205, when inherited from Chainina, were larger than carriers of 207 and showed a globally better body structure. No significant association was found in the animals that had inherited the alleles from Piemontese. It would be interesting to verify, in the chromosome portions flanking the mentioned marker (chromosome 19; q16 band), the existence of eventual coding sequences influencing growth and conformation.