bluuebunny/crossref_metadata_2025 huggingface dataset:
A social network perspective on heroin and cocaine use among adults: evidence of bidirectional influences
Authors: Bohnert Amy S. B. , Bradshaw Catherine P. , Latkin Carl A.
Published: June 2009

Aims  While several studies have documented a relationship between initiation of drug use and social network drug use in youth, the direction of this association is not well understood, particularly among adults or for stages of drug involvement beyond initiation. The present study sought to examine two competing theories (social selection and social influence) in the longitudinal relationship between drug use (heroin and/or cocaine) and social network drug use among drug‐experienced adults.

Design  Three waves of data came from a cohort of 1108 adults reporting a life‐time history of heroin and/or cocaine use.

Setting  Low‐income neighborhoods with high rates of drug use in Baltimore, Maryland.

Participants  Participants had weekly contact with drug users and were 18 years of age or older.

Measurements  Drug use data were self‐report. Network drug use was assessed through a social network inventory. Close friends were individuals whom the participant reported seeing daily or rated as having the highest level of trust.

Findings  Structural equation modeling indicated significant bidirectional influences. The majority of change in network drug use over time was due to change in the composition of the network rather than change in friends' behavior. Drug use by close peers did not influence participant drug use beyond the total network.

Conclusions  There is evidence of both social selection and social influence processes in the association between drug use and network drug use among drug‐experienced adults.
Temperance, alcohol, and the American evangelical: a reassessment
Authors: Warner Jessica
Published: June 2009

Abstinence from alcohol is a way of life for many American evangelicals, with rates of abstention running at over 70% among some Pentecostal denominations. This paper examines the religious beliefs that, historically, have supported teetotalism. The most notable of these is Christian perfection, a doctrine that originated in 18th‐century England, that was then radicalized in America in the early 19th century. Abstinence from alcohol is highest among denominations that make Christian perfection the cornerstone of their teachings, and lowest among those that discount human agency. The paper also argues that 19th‐century American evangelicals were by no means committed uniformly to temperance as a way of life, and that this was especially true of the various Methodist churches.
Quantitative analysis of net‐transgressive shoreline trajectories and stratigraphic architectures: mid‐to‐late Jurassic of the North Sea rift basin
Authors: Hampson Gary J. , Sixsmith Peter J. , Kieft Rachel L. , Jackson Christopher A. ‐L. , Johnson Howard D.
Published: June 2009

This paper outlines the use of the shoreline trajectory concept to understand the controls on net‐transgressive reservoir distribution and architecture in the highly productive Middle and Late Jurassic plays in the North Sea. Two broad groups of regressive–transgressive sandstone tongue are identified, with distinctive geometries, architectures and values of net‐transgressive shoreline trajectory defined by the stacking arrangement of multiple tongues. Shoreface tongues were supplied by longshore‐transported, marine‐reworked sediment and are associated with low‐to‐moderate transgressive trajectories (typically <0.2°). These tongues have variable dip extents that decrease weakly as the angle of shoreline trajectory increases, relatively small thicknesses that increase weakly with the angle of transgressive trajectory, and partial or no overlap with underlying and overlying tongues down depositional dip. Deltaic‐to‐estuarine tongues were supplied directly by fluvial sediment and are associated with moderate‐to‐very high transgressive trajectories (typically >0.1°). These tongues have small dip extents, variable thicknesses that increase weakly with the angle of transgressive trajectory, and partial to full overlap with underlying and overlying tongues down depositional dip, although vertically stacked tongues are separated by thin mudstones over much of their extents. There is some overlap in geometry and stacking arrangement of these two groups of sandstone tongues. The temporal and spatial distribution of shoreface and deltaic‐to‐estuarine sandstone tongues reflects linked variations in tectonic subsidence and sediment routing within the evolving rift basin. Deltaic‐to‐estuarine tongues with moderate‐to‐very high transgressive trajectories were developed in rapidly subsiding fault‐bounded depocentres supplied directly by fluvial sediment, whereas shoreface tongues with low‐to‐moderate transgressive trajectories characterised slowly subsiding fault terraces and platforms that were distant from fluvial sediment supply routes. Thus, the evolving structural template of the mid‐to‐late Jurassic North Sea rift can be used to predict reservoir distribution and architecture via analysis of shoreline trajectory.
Silent infarcts in young children with sickle cell disease
Authors: Kwiatkowski Janet L. , Zimmerman Robert A. , Pollock Avrum N. , Seto Wendy , Smith‐Whitley Kim , Shults Justine , Blackwood‐Chirchir Anne , Ohene‐Frempong Kwaku
Published: June 2009

Silent infarcts have been reported most commonly in school‐aged children with homozygous sickle cell disease (SCD‐SS) and are associated with neurocognitive deficits. However, the prevalence of silent infarcts in younger children with SCD‐SS is not well defined. In this retrospective study, brain magnetic resonance imaging and angiography (MRI/A) studies performed before 6 years of age in a cohort of children with SCD‐SS were analysed and the prevalence of abnormalities was calculated. Clinical and laboratory parameters were compared between the groups with and without silent infarcts. Sixty‐eight of 96 children in the cohort had brain MRI/A performed prior to age 6 years. Of the 65 who were neurologically asymptomatic, 18 (27·7%, 95% CI 17·3–40·2%) had silent infarcts (mean age 3·7 ± 1·1 years, range 1·3–5·9 years). Factors associated with silent infarcts included cerebral vessel stensosis by magnetic resonance angiography, lower rates of vaso‐occlusive pain and acute chest syndrome and lower haemoglobin levels. The prevalence of silent infarcts in young children with SCD‐SS is similar to that of older children and anaemia and severe vasculopathy may be risk factors.
Evaluation of aspiration cytology of ovarian masses with histopathological correlation
Authors: Sood T. , Handa U. , Mohan H. , Goel P.
Published: June 2009

T. Sood, U. Handa, H. Mohan and P. Goel  Evaluation of aspiration cytology of ovarian masses with histopathological correlation

Objectives:  To evaluate the efficacy and diagnostic accuracy of fine needle aspiration cytology (FNAC) in distinguishing non‐neoplastic and neoplastic ovarian lesions and to determine reliable cytological criteria for typing neoplastic ovarian masses into benign and malignant tumours and their subtypes.

Methods:  FNAC was performed on 50 patients diagnosed as having an ovarian mass clinically and/or ultrasonographically. Detailed history, clinical examination and ultrasound findings in each case were recorded. The cytological diagnoses were categorized as neoplastic and non‐neoplastic and further into benign and malignant neoplasms. These cytological diagnoses were then compared subsequently with the histopathological diagnoses.

Results:  The study material consisted of 57 aspirates from 50 patients. A comparison of cytological findings with the histological diagnosis was possible in 53 aspirates; in the remaining four cases (7%) the smears were acellular. On cytology, 31 lesions were diagnosed as neoplastic and 22 as non‐neoplastic. The overall sensitivity of cytology in diagnosing neoplastic and non‐neoplastic ovarian lesions was 93.9% and the specificity was 100%. The positive predictive value was 100% and negative predictive value 90.9%. The overall diagnostic accuracy was 96.2 %.

Conclusion:  FNAC of ovarian masses is a minimally invasive procedure that can differentiate neoplastic from non‐neoplastic ovarian lesions. It may help avoid unnecessary operations and preserve the reproductive ability in young patients. Furthermore, it also enables a satisfactory sub‐categorization of ovarian tumours, which facilitates the choice of appropriate therapy.
The non‐indigenous diatom Didymosphenia geminata alters benthic communities in New Zealand rivers
Authors: KILROY C. , LARNED S. T. , BIGGS B. J. F.
Published: June 2009

1. Blooms of the benthic, stalked diatom Didymosphenia geminata were first observed in New Zealand in 2004. Since then, D. geminata has spread to numerous catchments in the South Island and is also spreading in its native range. The species is a rare example of an invasive alga in lotic systems.

2. Ecosystem effects may be expected as D. geminata attains unusually high biomass in rivers. We examined data from three independent studies in three South Island, New Zealand, rivers for evidence of effects on periphyton biomass and benthic invertebrate communities.

3. The combined results confirmed that the presence of D. geminata was associated with greatly increased periphyton biomass and, in most cases, increased invertebrate densities. We also recorded shifts in community composition, dominated by increased densities of Oligochaeta. Chironomidae, Cladocera and Nematoda also generally increased in density with D. geminata. Significant increases or declines in other invertebrate taxa were inconsistent among rivers.

4. In all three studies, increased spatial invertebrate community homogeneity was associated with high D. geminata biomass at the within‐river scale. However, no declines in taxon richness or diversity were detected.

5. Although ecosystem effects of D. geminata on existing periphyton biomass and invertebrate communities are measurable, no inferences can be made from the present data about effects on higher trophic levels (fish).
Carbon assimilation mode in mixotrophs and the fatty acid composition of their rotifer consumers
Authors: WACKER ALEXANDER , WEITHOFF GUNTRAM
Published: June 2009

1. We examined an important ecophysiological link between the mixotrophic flagellate Chlamydomonas acidophila and its consumers, the rotifers Elosa worallii, Cephalodella sp. and Brachionus sericus, by comparing their fatty acid profiles.

2. The mixotrophic flagellate was grown under either exclusively autotrophic conditions in the light, under exclusively heterotrophic conditions in the dark with an organic carbon source (glucose), or in the light plus the organic carbon sources (=mixotrophic).

3. Under heterotrophic growth conditions, C. acidophila strongly reduced its content of the n‐3 polyunsaturated fatty acid (PUFA) alpha‐linolenic acid (ALA, C18:3n‐3) compared with auto‐ and mixotrophic growth conditions. Although PUFAs with more than 18 carbon atoms were not detected in C. acidophila, significant amounts of eicosatetraenoic (ETA, 20:4n‐3) and eicosapentaenoic acid (EPA, 20:5n‐3) were found in three rotifer consumers.

4. Species‐specific differences in the fatty acid profiles with respect to ETA, EPA and the precursor ALA were found in the rotifers: Brachionus and Cephalodella fed on the heterotrophic diets synthesised less EPA. In Elosa, smaller amounts of ALA were detected but were converted efficiently to a constant content of EPA and to an exceptionally high content of ETA.

5. Since in nature the mode of carbon assimilation among mixotrophic organisms differs, and their fatty acid composition varies depending on their mode of carbon assimilation, the availability of ALA might be critical for their consumers. An insufficient dietary supply of this precursor for the synthesis of ETA and EPA can prevent consumers from regulating their content of ETA and EPA. Therefore, observed differences in values of the latter might underly species‐specific differences in the competitive capability of consumers.
The mystery of the missing toes: extreme levels of natural mutilation in island lizard populations
Authors: Vervust Bart , Van Dongen Stefan , Grbac Irena , Van Damme Raoul
Published: June 2009

1. Ecological interactions that involve aggressive confrontations between animals are important in shaping the evolution of morphology, behaviour and life history. However, as such confrontations are rarely witnessed, direct quantification of the intensity of these processes in natural populations is notoriously difficult. While the utilization of the frequency of non‐lethal injuries is fraught with difficulties, it may provide information concerning different types of interaction, such as predation, intraspecific aggression and interspecific interference competition.

2. In this paper, we report on an exceptionally large difference in toe loss incidence between two populations of Podarcis sicula lizards living on small, neighbouring islands in the Adriatic Sea. We caught 900 lizards and recorded the number and location of missing toes. Subsequently, we investigated five non‐mutually exclusive hypotheses concerning differences in bite force capacity, bone strength, predation intensity, average age and intraspecific aggression that may provide proximate explanations for the observed differences in injury frequencies.

3. Bite force differences differed considerably between the populations, but bone strength was found to be stronger in the populations with a higher frequency of natural scars. Predation pressure clearly differed between the populations, but we found higher injury rates under predation relaxation.

4. Our results indicate that density and consequently an increased intraspecific competition is the most likely explanation for the observed high frequencies of injuries. We suggest that the intensity of toe amputation between lizard populations may be a useable indirect indication for the intensity of intraspecific competition.

5. This study shows how a combination of morphological, physiological, behavioural and ecological measurements can be used to test assumptions implicit to alternative explanations of an observed phenomenon. Such tests can reveal how likely each of these explanations is, even if the processes leading to the phenomenon are difficult to observe directly.
Diet predicts intestine length in Lake Tanganyika’s cichlid fishes
Authors: Wagner Catherine E. , McIntyre Peter B. , Buels Kalmia S. , Gilbert Danielle M. , Michel Ellinor
Published: June 2009

1.
 Among vertebrates, herbivores have longer digestive tracts than animals at higher trophic levels, a pattern thought to reflect a trade‐off between digestive efficiency and tissue maintenance costs. However, phylogenetic influences on this pattern have rarely been considered. Taxa that have undergone diversification accompanied by dietary shifts provide a powerful opportunity to examine the relationship between diet and intestine length while accounting for phylogeny.

2.
 In this paper we assess the relationship between diet and intestine length in the cichlid fishes of Lake Tanganyika, which are renowned for their diversity of species and trophic strategies.

3.
 First, we test the effect of trophic position on intestine length across 32 species, while controlling for phylogeny. Trophic position was inferred from nitrogen stable isotopes, which provide a temporally integrated, quantitative perspective on the complex diets of tropical fish. Second, we examine patterns of intraspecific variation in intestine length of an algivorous cichlid (Tropheus brichardi) along a natural spatial gradient in algal nitrogen content.

4.
 Trophic position explains 51% of size‐standardized variation in intestine length after accounting for phylogeny. Accounting for phylogeny does not substantially alter the relationship between trophic position and intestine length, despite the existence of phylogenetic signal in both traits. Thus, diet is a strong predictor of variation at the interspecific level.

5.
 There is a striking inverse relationship between intestine length and algal nutrient content among populations of T. brichardi, suggesting substantial plasticity in response to food quality, and thus a strong dietary influence on patterns of intraspecific variation.

6.
 Diet is a strong predictor of intestine length at both intra‐ and interspecific scales, indicating that fish adjust their phenotype to balance nutritional needs against energetic costs. Furthermore, functional explanations for trophic diversification of cichlid fishes in the African Great Lakes have long focused on jaw structures, but our results indicate that intestinal plasticity in response to diet quality may also be an important mechanism for accommodating trophic shifts during evolutionary radiations.
Clinical outcome of interferon and ribavirin combination treatment in hepatitis C virus infected patients with congenital bleeding disorders in Iran
Authors: RAHMANI M. , TOOSI M. N. , GHANNADI K. , LARI G. R. , JAZEBI M. , RASOULZADEGAN M. , ALA F.
Published: June 2009

Summary.  Hepatitis C virus (HCV) infection is a major cause of morbidity and mortality in patients with inherited bleeding disorders. The results of interferon and ribavirin combination therapy have been reported in a limited number of clinical trials on these patients. Peginterferon is a costly treatment. Conventional interferon and ribavirin therapy is still the main available and affordable antiviral therapy in some countries. The goal of this study was to assess the effectiveness and safety of interferon alfa‐2b plus ribavirin in HIV seronegative, non‐alcoholic, non‐cirrhotic, naïve subjects with congenital coagulopathy. Between May 2003 and August 2007, 103 haemophiliacs were treated consecutively with standard inclusion and exclusion criteria, with interferon alfa‐2b (PDferon B®) 3MIU three times a week subcutaneously plus ribavirin, for 24–48 weeks, with appropriate dose adjustments. They were all scheduled to have serial visits and laboratory tests. Among 7(6.8%) female and 96(93.2%) male haemophiliacs, 11(10.68%) cases did not complete the study because of psychological side effects. With intent‐to‐treat analysis, end‐of‐treatment response was 63.1%, and sustained virological response (SVR) was 56.3%. There was a significant correlation between SVR and genotype, baseline HCV viral load, rapid virological response, early virological response and BMI. A decrease in the haemoglobin level of two patients required ribavirin dose reduction. One developed thrombocytopenia at the end of treatment, but none had neutropenia. Hypothyroidism was observed in two patients. Interferon plus ribavirin combination therapy in HCV‐infected haemophilic patients is well tolerated and treatment outcomes appear to be similar to those seen in the general population.
Transplacental transfer of postpartum inhibitors to factor VIII
Authors: LULLA R. R. , ALLEN G. A. , ZAKARIJA A. , GREEN D.
Published: June 2009

Summary.  Acquired haemophilia due to antibodies directed against coagulation factor VIII is a well‐recognized cause of severe haemorrhage in adults but an uncommon cause of bleeding in children. We present the cases of a mother with a life‐threatening postpartum haemorrhage due to an autoantibody to factor VIII and her newborn who developed symptomatic bleeding after a minor surgical intervention as a result of transplacental transfer of the autoantibody. Both patients were treated with infusions of recombinant factor VIIa to control bleeding. The mother required immunosuppressive therapy to decrease inhibitor levels and the infant’s levels decreased over time without specific treatment. We also provide a concise review of postpartum haemophilia and transplacental transmission of factor VIII autoantibodies to the neonate – a rare but potentially life‐threatening complication of acquired haemophilia in women of childbearing age.
Development of a multiplex PCR assay for Photobacterium damselae subsp. piscicida identification in fish samples
Authors: Amagliani G , Omiccioli E , Andreoni F , Boiani R , Bianconi I , Zaccone R , Mancuso M , Magnani M
Published: June 2009

A multiplex polymerase chain reaction protocol for the detection of Photobacterium damselae and subspecies piscicida and damselae discrimination, with internal amplification control, was developed. Assay specificity was assessed by testing 19 target and 25 non‐target pure cultures. The detection limit was 500 fg, corresponding to 100 genome equivalents. The optimized protocol was also prevalidated with spleen, kidney and blood samples from infected and uninfected sea bass, without any culture step, and it can be proposed as a valid alternative to culture standard methods for the rapid and specific diagnosis of photobacteriosis in fish.
Tissue tropism of nervous necrosis virus (NNV) in Atlantic cod, Gadus morhua L., after intraperitoneal challenge with a virus isolate from diseased Atlantic halibut, Hippoglossus hippoglossus (L.)
Authors: Korsnes K , Karlsbakk E , Devold M , Nerland A H , Nylund A
Published: June 2009

Atlantic cod, Gadus morhua, averaging 100 g, were experimentally challenged by intraperitoneal injection of nervous necrosis virus (NNV) originating from Atlantic halibut. Cod tissues, including blood, gill, pectoral fin, barbel, ventricle, atrium, spleen, liver, lateral line (including muscle tissue), eye (retina) and brain, were sampled at day 25 and 130 and investigated by real‐time RT‐PCR for the presence of NNV. Relative quantifications at day 130 were calculated using the 2−ΔΔCt method. Immunosuppression by injection of prednisolone‐acetate was introduced for a 30‐day period, and tissue sampled at day 180 and relative quantification estimated. No mortality or clinical signs of disease were observed in the challenged group. The challenge resulted in detection of NNV in blood, spleen, kidney, liver, heart atrium and heart ventricle at day 25, and by the end of the experiment NNV showed a clear increase in brain and retina, suggesting these to be the primary tissues for viral replication. There was no increase in the relative amount of NNV in blood, atrium, ventricle, spleen, liver and kidney. Corticosteroid implants resulted in a weak increase in virus RNA in spleen, kidney, liver and brain. These findings suggest that Atlantic cod is susceptible to infection with NNV from halibut. The observed tissue tropism patterns suggest an initial viraemic phase, followed by neurotrophy. Head‐kidney is the best tissue identified for possible NNV detection by non‐lethal biopsy, but detection was not possible in all injected fish.
Outbreak of betanodavirus infection in tilapia, Oreochromis niloticus (L.), in fresh water
Authors: Bigarré L , Cabon J , Baud M , Heimann M , Body A , Lieffrig F , Castric J
Published: June 2009

A betanodavirus associated with a massive mortality was isolated from larvae of tilapia, Oreochromis niloticus, maintained in fresh water at 30 °C. Histopathology revealed vacuolation of the nervous system, suggesting an infection by a betanodavirus. The virus was identified by indirect fluorescent antibody test in the SSN1 cell line and further characterized by sequencing of a PCR product. Sequencing of the T4 region of the coat protein gene indicated a phylogenetic clustering of this isolate within the red‐spotted grouper nervous necrosis virus type. However, the tilapia isolate formed a unique branch distinct from other betanodavirus isolates. The disease was experimentally reproduced by bath infection of young tilapia at 30 °C. The reservoir of virus at the origin of the outbreak remains unidentified. To our knowledge, this is the first report of natural nodavirus infection in tilapia reared in fresh water.
Adiponectin Regulate Growth Hormone Secretion Via Adiponectin Receptor Mediated Ca2+ Signalling in Rat Somatotrophs In Vitro
Authors: Steyn F. J. , Boehme F. , Vargas E. , Wang K. , Parkington H. C. , Rao J. R. , Chen C.
Published: June 2009

Obesity is associated with reduced levels of growth hormone (GH) and the disruption of pulsatile GH secretion. This results in relative GH deficiency. It is likely that a regulatory relationship between GH secretion and adipose tissue exists as the secretion of GH recovers to normal levels after a reduction in body weight. This report characterise the expression and interaction of adiponectin receptors 1 and 2 (AdipoR1 and AdipoR2) and adiponectin, respectively, in regulating the activity of GH secreting cells. Polymerase chain reaction analysis of the GH3 cell line, rat anterior pituitary gland and isolated somatotroph cells from transgenic GFP expressing mice confirmed the expression of both AdipoR1 and AdipoR2 in GH secretory cells. Because GH cells expressed both receptors, it is likely that the measured increase in GH secretion, observed in primary cultured rat pituitary cells after 30 min of incubation with full‐length murine adiponectin, was mediated by a direct receptor regulated process. Adiponectin induced an increase in intracellular Ca2+ through both the influx of extracellular Ca2+ and the release of intracellular Ca2+ stores resulting in the secretion of GH. Furthermore, results confirm that this increase in GH secretion depended mainly on an increase in Ca2+ influx through L‐type Ca2+ channels. It is concluded that adiponectin directly regulates GH secretion from somatotrophs by binding to either adiponectin receptor, and that this is mediated via a similar process observed after the stimulation of GH secretion by GH‐releasing hormone.
Hypothalamic Vasopressin and Oxytocin mRNA Expression in Relation to Depressive State in Alzheimer’s Disease: A Difference With Major Depressive Disorder
Authors: Meynen G. , Unmehopa U. A. , Hofman M. A. , Swaab D. F. , Hoogendijk W. J. G.
Published: June 2009

Arginine vasopressin (AVP) and oxytocin (OXT), produced in the hypothalamic paraventricular (PVN) and supraoptic nucleus (SON), are considered to be involved in the pathophysiology of major depressive disorder (MDD). The objective of this study was to determine, for the first time, the relationship between AVP and OXT gene expression and depressive state in Alzheimer’s disease (AD). Post‐mortem brain tissue was obtained from six control subjects, and from a prospectively studied cohort of 23 AD patients, using the DSM‐IIIR and the Cornell Scale for Depression in Dementia to determine depression diagnosis and severity. The amount of AVP and OXT mRNA was determined by in situ hybridisation. AD patients did not differ from controls with respect to the amount of AVP or OXT mRNA in the PVN or SON. Also, no differences were found between depressed and nondepressed AD patients and no relationship was found between the depression severity and AVP or OXT mRNA expression. The results indicate that AVP and OXT gene expression in the PVN and SON is unchanged in depressed AD patients compared to nondepressed AD patients. This is in contrast with the enhanced AVP gene expression in MDD, suggesting a difference in pathophysiology between MDD and depression in AD.
Geographical variation in genetic structure of an Atlantic Coastal Forest frog reveals regional differences in habitat stability
Authors: FITZPATRICK SARAH W. , BRASILEIRO CINTHIA A. , HADDAD CÉLIO F. B. , ZAMUDIO KELLY R.
Published: June 2009

Climatic oscillations throughout the Pleistocene combined with geological and topographic complexity resulted in extreme habitat heterogeneity along the Atlantic coast of Brazil. Inferring how these historic landscape patterns have structured the current diversity of the region's biota is important both for our understanding of the factors promoting diversification, as well as the conservation of this biodiversity hotspot. Here we evaluate potential historical scenarios of diversification in the Atlantic Coastal Forest of Brazil by investigating the population genetic structure of a frog endemic to the region. Using mitochondrial and nuclear sequences, we generated a Bayesian population‐level phylogeny of theThoropa miliarisspecies complex. We found deep genetic divergences among five geographically distinct clades. Southern clades were monophyletic and nested within paraphyletic northern clades. Analyses of historical demographic patterns suggest an overall north to south population expansion, likely associated with regional differences in habitat stability during the Pliocene and early Pleistocene. However, genetic structure among southern populations is less pronounced and likely represents more recent vicariant events resulting from Holocenic sea‐level oscillations. Our analyses corroborate that the Atlantic Coastal Forest has been a biogeographically dynamic landscape and suggest that the high diversity of its fauna and flora resulted from a combination of climatic and geologic events from the Pliocene to the present.
Contrasting patterns of genetic diversity at three different genetic markers in a marine mammal metapopulation
Authors: HOFFMAN J. I. , DASMAHAPATRA K. K. , AMOS W. , PHILLIPS C. D. , GELATT T. S. , BICKHAM J. W.
Published: June 2009

Many studies use genetic markers to explore population structure and variability within species. However, only a minority use more than one type of marker and, despite increasing evidence of a link between heterozygosity and individual fitness, few ask whether diversity correlates with population trajectory. To address these issues, we analysed data from the Steller's sea lion, Eumetiopias jubatus, where three stocks are distributed over a vast geographical range and where both genetic samples and detailed demographic data have been collected from many diverse breeding colonies. To previously published mitochondrial DNA (mtDNA) and microsatellite data sets, we have added new data for amplified fragment length polymorphism (AFLP) markers, comprising 238 loci scored in 285 sea lions sampled from 23 natal rookeries. Genotypic diversity was low relative to most vertebrates, with only 37 loci (15.5%) being polymorphic. Moreover, contrasting geographical patterns of genetic diversity were found at the three markers, with Nei's gene diversity tending to be higher for AFLPs and microsatellites in rookeries of the western and Asian stocks, while the highest mtDNA values were found in the eastern stock. Overall, and despite strongly contrasting demographic histories, after applying phylogenetic correction we found little correlation between genetic diversity and either colony size or demography. In contrast, we were able to show a highly significant positive relationship between AFLP diversity and current population size across a range of pinniped species, even though equivalent analyses did not reveal significant trends for either microsatellites or mtDNA.
A quantitative review of heterozygosity–fitness correlations in animal populations
Authors: CHAPMAN J. R. , NAKAGAWA S. , COLTMAN D. W. , SLATE J. , SHELDON B. C.
Published: June 2009

The ease of obtaining genotypic data from wild populations has renewed interest in the relationship between individual genetic diversity and fitness‐related traits (heterozygosity–fitness correlations, or HFC). Here we present a comprehensive meta‐analysis of HFC studies using powerful multivariate techniques which account for nonindependence of data. We compare these findings with those from univariate techniques, and test the influence of a range of factors hypothesized to influence the strength of HFCs. We found small but significantly positive effect sizes for life‐history, morphological, and physiological traits; while theory predicts higher mean effect sizes for life‐history traits, effect size did not differ consistently with trait type. Newly proposed measures of variation were no more powerful at detecting relationships than multilocus heterozygosity, and populations predicted to have elevated inbreeding variance did not exhibit higher mean effect sizes. Finally, we found evidence for publication bias, with studies reporting weak, nonsignificant effects being under‐represented in the literature. In general, our review shows that HFC studies do not generally reveal patterns predicted by population genetic theory, and are of small effect (less than 1% of the variance in phenotypic characters explained). Future studies should use more genetic marker data and utilize sampling designs that shed more light on the biological mechanisms that may modulate the strength of association, for example by contrasting the strength of HFCs in mainland and island populations of the same species, investigating the role of environmental stress, or by considering how selection has shaped the traits under investigation.
Genetic structure and population dynamics of a heteroecious plant pathogenMelampsora larici‐epiteain short‐rotation coppice willow plantations
Authors: BAYON CARLOS , PEI MING H. , RUIZ CARMEN , HUNTER TOM , KARP ANGELA , TUBBY IAN
Published: June 2009

Complex life strategies are common among plant pathogens belonging to rust fungi (Uredinales). The heteroecious willow rustMelampsora larici‐epiteaproduces five spore stages and alternates on larch (Larix). To shed light on the epidemiology of this pathogen, amplified fragment length polymorphisms (AFLPs) were used to determine the genetic diversity and genetic structure of rust samples collected from coppice willow (Salix) plantations at three UK sites (LA, CA and MC) over three sampling dates (September 2000, July 2001 and September 2001). Of the total of 819 isolates, 465 were unique AFLP phenotypes and there was a shift in genotype diversity between the two seasons (0.67 in 2000 and 0.87–0.89 in 2001). No phenotypes were common between the two seasons within a site, suggesting that the rust did not overwinter as an asexual stage within plantations. A temporal analysis detected large amounts of genetic drift (FS = 0.15–0.26) between the two seasons and very small effective population sizes (Ne = 2–3) within sites. These results all point to a new colonization of the plantations by the rust in the second season (2001). TheFST‐analogue values were ΦCT = 0.121, Weir and Cockerham’s θ = 0.086 and the Bayesian estimate θB = 0.087–0.096. The results suggest that the sources of inoculum were somewhat localized and the same sources were mainly responsible for disease epidemics in LA and CA over the two seasons. The relatively lowFST‐values among sites (0.055–0.13) suggest the existence of significant gene flow among the three sampled sites.
Fractal characterisation of plant canopies and application in spray retention modelling for arable crops and weeds
Authors: PATHAN A K , KIMBERLEY M O , FORSTER W A , HASLETT M R , STEELE K D
Published: June 2009

Fractal analysis can provide a unique mathematical tool to quantify the geometry of irregular and complex plant canopies. This study demonstrated that a single numerical fractal dimension (FD) value derived from an image taken from above the plant canopy could differentiate between and rank the canopies of a range of plant species. We also investigated the influence of canopy architecture and surface characteristics on spray retention. Multiple regressions were used to derive mathematical relationships and develop a spray retention model. It was discovered that the FD value can successfully be used to replace the statistically generated plant morphological factor (Mp4) used in a previous retention model, with the major advantage being that the retention model now only involves variables that can be readily measured. There is an excellent relationship (R2 = 0.99) between actual spray retention per plant (μL) and that predicted by the model incorporating the FD. The spray retentiveness of the plant species studied was ranked using a numerical index based on plant canopy architecture and surface characteristics.
Identification of a new HLA‐A*29 allele, HLA‐A*290102 by sequence‐based typing in a Chinese individual
Authors: Zhu F.‐M. , Zhang W. , He J. , Yan L.‐X.
Published: June 2009

A novel human leukocyte antigen (HLA)‐A allele has been identified in a Chinese individual. HLA‐A*290102 allele is different from HLA‐A*29010101 by one nucleotide silent substitution at position 448T>C in exon 3.
HLA haplotypes and birth weight variation: is your future going to be light or heavy?
Authors: Capittini C. , Pasi A. , Bergamaschi P. , Tinelli C. , De Silvestri A. , Mercati M. P. , Badulli C. , Garlaschelli F. , Sbarsi I. , Guarene M. , Martinetti M. , Salvaneschi L. , Cuccia M.
Published: June 2009

Birth weight is known to be a direct indicator of perinatal mortality and a clear predictor of adult pathologies too. It has been correlated with several causes of mortality in adulthood: low birth weight with diabetes, nephropathy and cardiovascular diseases and high birth weight with autoimmune diseases and cancer. In genome‐wide studies, an extended human leucocyte antigen (HLA) region has been linked to birth weight variation. We focused our attention on the HLA haplotypes marked by HLA‐A, HLA‐B and HLA‐DRB1 polymorphisms in 1206 healthy Caucasian newborns belonging to the Cord Blood Bank of Pavia (Italy) and their mothers, aiming to investigate the association between this restricted HLA region and birth weight variation. In our study, the HLA‐B*38;DRB1*13 haplotype showed an ascending trend among centiles addressing to the high foetal weight. The HLA‐A*02;B*15 haplotype showed a descending trend among centiles addressing to the low foetal weight. Besides the acknowledged correlation between the HLA‐A*02 and HLA‐B*15 alleles (as well as low birth weight) and type I diabetes and between the HLA‐B*38 and HLA‐DRB1*13 alleles (as well as high birth weight) and several autoimmune diseases, we cannot predict if our babies, healthy at birth, will suffer from these pathologies during life. Nevertheless, our data point to the HLA telomeric end for markers linked to the low birth weight and to the HLA centromeric end for markers linked to the high birth weight, thus limiting the region involved in birth weight variation, which still represents a useful predictor of disease risk in adulthood.
Three new HLA‐A alleles determined by sequence‐based typing: A*2493, A*2918 and A*0342
Authors: Dubois V. , Giannoli C. , Favre‐Victoire I.
Published: June 2009

In this study, we report the identification of three new human leukocyte antigen class I alleles: A*2493, A*2918 and A*0342 found by routine typing using commercial kits. The names A*2493 (HWS 10005702), A*2918 (HWS 10005703) and A*0342 (HWS 10005705) have been officially assigned by the World Health Organization Nomenclature Committee in August 2008.
Divergence in host use ability of a marine herbivore from two habitat types
Authors: VESAKOSKI O. , RAUTANEN J. , JORMALAINEN V. , RAMSAY T.
Published: June 2009

We studied ecological divergence of host use ability in a generalist marine herbivore living in two distinct host plant assemblages. We collectedIdotea balthicaisopods from three populations dominated by the brown algaFucus vesiculosusand three dominated by the seagrassZostera marina. In two reciprocal common garden feeding experiments for adult and laboratory‐born juvenile isopods, we found that isopods from both assemblages performed better with their sympatric dominant host species than did isopods allopatric to this host. This indicates parallel divergence of populations according to the sympatric host plant assemblage. Furthermore, initial body size and body size‐dependent mortality differed between populations from the two assemblages. In nature, this may result in lower fitness of immigrants compared with that of residents and consequently reinforce divergence of the populations. Finally, we discuss how phenotypic plasticity and maternal and random effects may associate with the results.
Compatibility of codling moths Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) from South Africa with codling moths shipped from Canada
Authors: Bloem S. , Carpenter J. E. , Blomefield T. L. , Harrison C.
Published: June 2009

The sterile insect technique (SIT) has been successfully applied against codling moth Cydia pomonella (Linnaeus) (Lepidoptera; Tortricidae) in British Columbia since 1992 where the mass‐rearing facility produces between 15 and 16 million moths per week. Due to the seasonality of this pest, the facility is only fully utilized for part of the year. The time and expense of implementing SIT against codling moth in South Africa may be substantially reduced if moths from Canada were sexually compatible with those from South Africa. In addition, because the pome fruit‐growing season in both countries is opposite, the programme in Canada might benefit by maintaining moth production year‐round and selling moths to South Africa. Semi‐field studies in small cages and release‐recapture studies were conducted in an unsprayed apple orchard in South Africa to assess mating compatibility of laboratory‐reared codling moth from Canada and wild codling moths from South Africa. The results suggest that Canadian codling moth males were equally attracted to calling Canadian and South African females despite the fact that Canadian moths had been transported (from Canada to South Africa) for 48 h as both pupae and adults. The data also suggest that at lower field temperatures Canadian moths were more active than South African moths. Results from the release‐recapture field trials indicated that Canadian and South African males were equally attracted to Canadian and South African females. These results suggest that codling moths from Canada and South Africa are fully compatible and indicate that Canadian moths can be used for SIT studies in South Africa. As these studies were conducted with moths from two very different climatic and time zones, it is proposed that populations of codling moth in other pome fruit production areas may also be compatible with the Canadian moths.
Cytological and molecular characterization of a new cytoplasmic male sterility in rapeseed
Authors: Wei W. L. , Wang H. Z. , Liu G. H.
Published: June 2009

It is very important for rapeseed hybrid production to develop and utilize a novel cytoplasmic male sterility (CMS) system concerning the possible risk because of a narrow cytoplasm background. Here the anatomy of anther development in the CMS system, named NCa, was observed using light microscope and transmission electron microscope, and the restriction fragment length polymorphism (RFLP) analyses of mitochondrial DNA of NCa sterile line were also performed in comparison with the other rapeseed sterile lines, such as pol, nap, ogura, and tour. The anther abortion of this CMS line occurred at the later uninucleate microspore stage, and the anatomic aborting characteristics were obviously different from all the other rapeseed CMS lines reported before. The RFLP analyses revealed that five probe/enzyme combinations could distinguish the five CMS lines. The results of anatomic observations and mitochondrial DNA polymorphism indicated that the NCa CMS system is a novel one which differs from the pol, nap, ogura, and tour systems.
A high‐throughput, low cost gel‐based SNP assay for positional cloning and marker assisted breeding of useful genes in cereals
Authors: Xu X. , Babu R. , Fujimura T. , Kawasaki S.
Published: June 2009

Several SNP (single nucleotide polymorphism) genotyping methods have been developed in the past most of which require sophisticated instrumentation and large initial investments. We describe here a high‐throughput SSCP (single strand conformation polymorphism) system on our HEGS (high efficiency genome scanning) platform, which is simple, accurate, cost effective and requires neither restriction digestion of the amplification products nor elaborate post‐PCR processing detection. Several parameters critical to SSCP analysis were optimized viz., gel matrix and concentration, gel running temperature, buffer composition, running conditions and PCR primer design so as to identify SNPs in amplicons ranging from 100 to 750 bp in size. A simple post‐PCR processing system was developed using fluorescent dye for quick and easy detection of SNP polymorphism. HEGS‐SSCP was also found to be useful in uncovering simple sequence repeat differences between different genotypes that differ by one or few di/tri nucleotide repeats. The practical utility of this system is illustrated with two successful efforts towards construction of high resolution linkage maps of a lesion mimic locus on chromosome 7 and a major quantitative trait locus conditioning field blast resistance on chromosome 4 in rice.
Characterization of a green non‐dormant sunflower (Helianthus annuus) mutant NDG
Authors: Vick B. A. , Cook L. W. , Jan C. C.
Published: June 2009

A sunflower (Helianthus annuus L.) mutant was observed in the progeny of a cross between the sunflower cultivar ‘HA 89’ and an amphiploid of a Helianthus divaricatus L. × P21 cross that exhibited loss of dormancy induction in the developing embryo. Seeds of this mutant frequently germinate on the head about 40 days after pollination. The cotyledons of this mutant remain green, whereas some other non‐dormant mutants exhibit loss of pigmentation. The objectives of this investigation were to compare levels and activities of abscisic acid (ABA), a plant hormone that induces dormancy in developing embryos, in the non‐dormant green mutant (NDG) and ‘HA 89’ from which NDG was derived. Immunoassays showed that abscisic acid was present in NDG and the levels were not significantly different from those in ‘HA 89’. Exposure of excised NDG mutant embryos to 40 μm abscisic acid failed to prevent germination, suggesting that non‐dormancy could result from impairment in ABA receptors or from a defect in other proteins participating in the subsequent signalling pathway that normally induces dormancy.
Floristic homogenization by native ruderal and alien plants in north‐east Spain: the effect of environmental differences on a regional scale
Authors: Pino Joan , Font Xavier , De Cáceres Miquel , Molowny‐Horas Roberto
Published: June 2009

Aim  To evaluate the relative potential contribution of native ruderals and aliens to plant homogenization at a regional scale, after taking into account the effect of diverse environmental distances.

Location  Catalonia (north‐east Spain)

Methods  We have used the flora module of the BDBC project (Catalonian Database of Biodiversity), which provides information on plant species distribution per 10 × 10 km Universal Transverse Mercator (UTM) cell. Pairwise floristic similarities of: (1) total, (2) native non‐ruderal, (3) native ruderal, and (4) alien vascular plant species have been calculated for a particularly well‐sampled subset of UTM cells, using a modified version of the Simpson index. These similarities have been compared per UTM pair using Mantel tests, before and after considering their relative association with geographical, climatic and landscape distances from linear regression models. The floristic similarity of both total and native non‐ruderal species was also correlated with the proportion of alien and native ruderal species after discounting the effects of environmental distances.

Results  The proportion of variance explained by environmental correlates was highest for the floristic similarity of native non‐ruderal plants and lowest for that of aliens. In all plant groups, climatic distance was the main significant variable of species similarity. Geographical distance was only significant for total and native non‐ruderal species and was of secondary importance in both cases. Landscape distance was not significant in any case. Similarities among both aliens and native ruderals were significantly higher than among native non‐ruderals, but these differences disappeared after removing the effect of environmental distances.

Main conclusions  Species similarity between sites may depend on differences in environmental factors other than geographical distance. This has to be taken into account when exploring the implications for biotic homogenization. In the case of Catalonian flora, the potentially homogenizing effect of native ruderal and alien species seems to be associated with their lower dependence on geographical distance and climatic factors compared with those of native, non‐ruderal species.