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Selected AbstractsRecognition of depressive symptoms in the elderly: What can help the patient and the doctorDEPRESSION AND ANXIETY, Issue 3 2002Ioannis A. Parashos M.D. Abstract The general public heavily underrecognizes depression and depressive symptoms. This underrecognition is more pronounced among elderly people, and this study is an initial attempt to quantify the problem in a Greek elderly sample. Additionally the authors attempt to identify patient-related factors, which can assist a subject to recognize the depressive symptoms and the general practitioner to note their existence. Members of senior citizen centers (n = 682) participated in presentations about "depression in the elderly" and completed a questionnaire including the GDS-4 scale, four questions concerning depression risk factors and a question concerning a recent visit to a physician for depressive symptoms. Amongst those participating, 35.8% presented depressive symptoms (GDS-4 , 2). The calculated rate for recognition of depression in the studied population was very low (17.3%). Patients with depressive symptoms were more often females and had a higher proportion of past history of depression and a lack of social support. Patients with a past history of depression and more severe forms of illness consulted a doctor more frequently. Finally, subjects suffering from depressive symptoms and comorbid medical illness were characterized by a higher proportion of past history, lack of support, and existence of multiple risk factors. The authors propose that the inclusion in public campaigns of activities with an experiential dimension, e.g., patient videos and the use of a very simple screening tool, such as the GDS-4 scale by general practitioners (GP), could be helpful in improving the recognition of depressive symptoms by the patient and his/her relatives and its diagnosis by the doctor. This proposition awaits formal proof in future studies. Depression and Anxiety 15:111,116, 2002. © 2002 Wiley-Liss, Inc. [source] The global challenge of type 2 diabetes and the strategies for response in ethnic minority groupsDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 6 2010Flavio Lirussi Abstract Ethnic minorities living in high-income countries usually exhibit a greater risk of developing diabetes along with higher morbidity and mortality rates. We evaluated the effectiveness of interventions to improve glycaemic control in ethnic minority groups. Results of major controlled trials, systematic reviews and meta-analyses were included in the review. Only 1/47 studies addressing diet and exercise interventions reported details on the ethnicity of the studied population. Self-management education was successful if associated with increased self-efficacy; delivered over a longer period; of high intensity; culturally tailored; and when using community educators. Strategies adopted in community-gathering places, family-based, multifaceted, and those tackling the social context were likely to be more effective. A positive relationship was found between social support and self-management behaviour as well as quality of life, but there is little evidence about the impact of organizational changes within health-care services on diabetes control. More research is needed to strengthen the evidence on effective strategies for response to diabetes in ethnic minorities. Also, there is a need to take into account diabetes beliefs and communication difficulties, as well as potential protective factors. Globally, many health-care systems are inadequately equipped to improve diabetes prevention and disease outcomes in these communities. Copyright © 2010 John Wiley & Sons, Ltd. [source] Methylenetetrahydrofolate reductase 677C/T gene polymorphism, gastric cancer susceptibility and genomic DNA hypomethylation in an at-risk Italian populationINTERNATIONAL JOURNAL OF CANCER, Issue 3 2006Francesco Graziano Abstract We performed a case-control study to examine the relationship between MTHFR C677T gene polymorphism (MTHFR677C/T) and gastric cancer susceptibility in at-risk populations in central Italy. To explore genomic DNA hypomethylation as a potential etiologic mechanism, this phenomenon was evaluated in carriers of the MTHFR677T/T genotype and carriers of the wild-type MTHFR677C/C genotype. Lymphocyte genomic DNA from 162 gastric cancer patients and 164 controls was used for MTHFR677C/T genotyping. Unconditional regression analysis with ORs and 95% CIs was used to investigate the association of the polymorphism with disease. Genomic DNA methylation status by an established enzymatic assay that measures the DNA accepting capacity of methyl groups (inversely related to endogenous methylation) was assessed in a random sample of 40 carriers of the wild-type MTHFR677C/C genotype and 40 carriers of the MTHFR677T/T genotype. The global allelic distribution was in Hardy-Weinberg equilibrium. The MTHFR677T allele was significantly associated with gastric cancer risk with an OR of 2.49 (95% CI 1.48,4.20) in heterozygous MTHFR677C/T carriers and an OR of 2.85 (95% CI 1.52,5.35) in homozygous MTHFR677T/T carriers. This risk association was retained in subgroup analyses by tumor histotype and location. Genomic DNA hypomethylation status in MTHFR677T/T carriers was significantly higher than in subjects with wild-type MTHF677C/C genotype (p = 0.012). In the studied population, MTHFR677T played the role of a moderate-penetrance gastric cancer susceptibility allele. Possession of the MTHFR677T/T genotype was significantly associated with genomic DNA hypomethylation. These findings deserve further investigation in the context of novel strategies for gastric cancer prevention. © 2005 Wiley-Liss, Inc. [source] Diagnostic clues to megaloblastic anaemia without macrocytosisINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2007C. W. J. CHAN Summary Masking of the macrocytic expression of megaloblastic anaemia (MA) by coexisting thalassaemia, iron deficiency and chronic illness has been widely reported. We described the haematological and clinical features of 20 Chinese patients with MA presenting with mean corpuscular volume (MCV) ,99 fl, and analysed the steps leading to the final diagnosis of MA with concomitant thalassaemia trait (n = 11), thalassaemia trait and iron deficiency (n = 3), iron deficiency (n = 4) and chronic illness (n = 2). We also compared the haematological characteristics of this group of patients with a group of normocytic anaemic patients without vitamin B12/folate deficiency, and identified certain laboratory information useful for differentiating the two groups. Statistically significant parameters included the mean values of haemoglobin, MCV, red cell distribution width (RDW), reticulocyte index, platelet count and serum bilirubin. All provided clues to maturation disorders within the marrow. A decision flowchart for the diagnosis of MA without macrocytosis was proposed. In the studied population, by using the parameters of haemoglobin <10 g/dl, MCV 80,99 fl, RDW , 16% and reticulocyte index , 2% as indicators, there was a 58% chance that a patient had MA without macrocytosis if he/she had all the four indicators, and a 2.2% chance of having it if he/she did not have these indicators. We emphasized the importance of including peripheral blood smear examination in the diagnostic procedures for such patients, as well as the importance of paying attention to patients' medical history, racial background and previous MCV value. [source] Lack of evidence for improved immune response of extra-pair nestlings in collared flycatcher Ficedula albicollisJOURNAL OF AVIAN BIOLOGY, Issue 5 2008Tomasz Wilk Extra-pair paternity is common in many socially monogamous bird species. Increasing evidence suggests that extra-pair copulations are female-driven, but benefits for females mating outside social pair-bonds are still poorly understood. The most influential explanation, "good genes" hypothesis, states that females mated socially with low quality males, engage in extra-pair copulations to obtain genetic benefits for their progeny. According to this model, enhanced performance of extra-pair offspring is expected. Here, based on 4-year study of collared flycatcher Ficedula albicollis, we compared the condition of extra-pair and within-pair young. We found no difference in immune response and body size between maternal half-siblings raised in the same nests. Additionally sex ratio was not biased among extra-pair nestlings, and paternity was not associated with hatching rank. Our results failed to reveal "good genes" effects in the studied population. These effects might be hard to detect, but other hypotheses should also be studied more thoroughly in the future. [source] IS THERE AN ECOPHYSIOLOGICAL EXPLANATION FOR THE GAMETOPHYTE,TETRASPOROPHYTE RATIO IN GELIDIUM SESQUIPEDALE (RHODOPHYTA)?,JOURNAL OF PHYCOLOGY, Issue 2 2006Raquel Carmona In the fall, when 61% of the fronds of the Gelidium sesquipedale (Clem.) Born. et Thur. population located in Albufeira (southern Portugal) were reproductive, about 90% of these fronds were tetrasporophytes, whereas an equal percentage of female and male gametophytes was found (5%). The comparison of physiological performances of the reproductive phases (males, females and tetrasporophytes) did not reveal a physiological advantage of tetrasporic fronds. There were no significant differences either in the photosynthesis, nitrogen uptake, nitrate reductase activity, or biochemical composition of adult fronds. On the other hand, vegetative recruitment and spore production in the laboratory were significantly different. The re-attachment to calcareous substrate and the subsequent rhizoidal growth were faster in tetrasporophytes. Particular levels of temperature, rather than irradiance, had an important effect on the phase differences in the spore release, attachment, and germination rates. Significant results were the higher release of carpospores at all irradiances at 17°C, and the higher attachment percentage of carpospores at 13°C versus tetraspores. Under higher temperatures (21°C), tetraspores showed higher attachment rates while carpospores germinated more. G. sesquipedale cystocarps released carpospores for 2 months, while tetrasporangia stopped shedding tetraspores after 1 month, resulting in a 3-fold higher production of carpospores than tetraspores. Results showed that vegetative and spore recruitment may explain the low gametophyte,tetrasporophyte ratio of the studied population of G. sesquipedale as opposed to the physiological performance of phases. [source] Extensive spatial genetic structure revealed by AFLP but not SSR molecular markers in the wind-pollinated tree, Fagus sylvaticaMOLECULAR ECOLOGY, Issue 5 2007ALISTAIR S. JUMP Abstract Studies of fine-scale spatial genetic structure (SGS) in wind-pollinated trees have shown that SGS is generally weak and extends over relatively short distances (less than 30,40 m) from individual trees. However, recent simulations have shown that detection of SGS is heavily dependent on both the choice of molecular markers and the strategy used to sample the studied population. Published studies may not always have used sufficient markers and/or individuals for the accurate estimation of SGS. To assess the extent of SGS within a population of the wind-pollinated tree Fagus sylvatica, we genotyped 200 trees at six microsatellite or simple sequence repeat (SSR) loci and 250 amplified fragment length polymorphisms (AFLP) and conducted spatial analyses of pairwise kinship coefficients. We re-sampled our data set over individuals and over loci to determine the effect of reducing the sample size and number of loci used for SGS estimation. We found that SGS estimated from AFLP markers extended nearly four times further than has been estimated before using other molecular markers in this species, indicating a persistent effect of restricted gene flow at small spatial scales. However, our SSR-based estimate was in agreement with other published studies. Spatial genetic structure in F. sylvatica and similar wind-pollinated trees may therefore be substantially larger than has been estimated previously. Although 100,150 AFLP loci and 150,200 individuals appear sufficient for adequately estimating SGS in our analysis, 150,200 individuals and six SSR loci may still be too few to provide a good estimation of SGS in this species. [source] Distribution of fimA genotypes of Porphyromonas gingivalis in subjects with various periodontal conditionsMOLECULAR ORAL MICROBIOLOGY, Issue 4 2004C. G. Missailidis Fimbria encoded by the gene fimA is considered one of the main factors in the colonization of the oral cavity by Porphyromonas gingivalis. Allelic variation in fimA led to the classification of strains of P. gingivalis into six genotypes. The occurrence of P. gingivalis was determined by polymerase chain reaction using 16S rRNA primers in 302 subgingival samples obtained from 102 Brazilian subjects exhibiting different periodontal conditions. Distribution of fimA genotypes was assessed in 146 P. gingivalis positive samples by polymerase chain reaction using primers pairs homologous to the different fimA genes. P. gingivalis was detected in 51 of 57 (89.4%) patients with periodontal attachment loss, in six of 20 gingivitis patients (30.0%) and in two of 25 (8.0%) subjects with a healthy periodontium. Variant type II was the only type detected in 53 sites (39.3%), distributed among 19 periodontitis patients (37.3%) and in one patient with no periodontal destruction. Type Ib was the second most prevalent genotype in periodontitis patients (19.6%). Genotype V was not detected in the studied population. Type IV was the most commonly type found among gingivitis patients, either alone or in combination with other genotypes. Multiple genotypes were detected in nine sites (6.1%). A fimA genotype was not identified in 26 sites (17.8%) of 146 sites positive for P. gingivalis, suggesting that other alleles of fimA not yet sequenced may be prevalent in this population. These data demonstrated that P. gingivalis type II strains followed by type Ib are more prevalent in periodontitis patients from a multiracial population in Brazil, suggesting an increased pathogenic potential of these types. [source] Female mating success and risk of pre-reproductive death in a protandrous grasshopperOIKOS, Issue 2 2002Raúl Cueva Del Castillo Numerous studies have assessed the adaptive value of protandry for males in several insect species, considering that male emergence is determined by female availability. However, the possible advantage of the time of emergence for females on their mating success in protandrous insect species has only been explored theoretically. By studying the grasshopper Sphenarium purpurascens we evaluated the hypothesis that late emergence could be adaptive for females. If female maturation occurs when the population density is higher and the sex ratio (males/females) is biased to males, their probability of mating increases. Thus, in this study we estimated (1) the opportunity for mating in females as a function of their sexual maturation time, population density, and sex ratio at the moment they reached sexual maturity. In addition, (2) an analysis incorporating female body size and the total number of female matings was performed. Both analyses support the occurrence of protandry in the studied population. Under the first approach, females with intermediate maturation time had a higher probability of being mated than earlier and late matured females. Thus, it suggests that stabilising selection is acting on female maturation time and this may affect selection on male maturation time. Furthermore, the proportion of mated females increased when the sex ratio was biased to males, and stabilising selection on maturation time was detected also. However, the number of matings of a female depended on her body size. Females with larger body size had more matings than smaller ones at the beginning of the reproductive season. Because selection acts differently on maturation time in males and females of S. purpurascens this result is consistent with a condition for the maintenance of protandry in the population. The present results are discussed in the light of the models for the evolution of protandry. [source] Six-minute walk test in obese children and adolescents: Reproducibility and validity,PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 2 2009Gunilla Morinder Abstract Background and Purpose.,The six-minute walk test (6MWT) is increasingly used in clinical practice. The aims of this study were to determine the reproducibility of the 6MWT in obese children and adolescents, to describe walking capacity in this population and compare the results with values from normal-weight children (known group validity), and, finally, to describe the correlation between distance walked and estimated maximum oxygen uptake (VO2max).,Methods.,Reproducibility was determined by a test,retest design and known group validity by a comparative design. The 6MWT was first test,retested in 49 obese children (30 boys, 19 girls, 8,16 years, body mass index [BMI] 24.9,52.1,kg?m,2). Then, for validation, 250 obese children (126 boys, 124 girls, 8,16 years, BMI 23.2,57,kg/m2) and 97 normal-weight children (48 boys, 49 girls, 8,16 years, BMI 13.3,23.2,kg·m,2) performed the 6MWT. The obese children also performed a sub-maximal bicycle ergometry test.,Results.,In the test,retest, the obese children walked 571,m the first test and 57,m the second (p = 0.578). The measurement error (Sw) was 24,m, coefficient of variation (CV): 4.3% and the intraclass correlation (ICC1:1): 0.84. Repeatability was 68,m, and limits of agreement were +71 and ,65,m. In comparison mean (standard deviation), six-minute walk distance (6MWD) in the obese children was 571,m (65.5), and in the normal-weight children, 663,m (61.1) (p < 0.001). The correlation between 6MWD and estimated VO2max (r = 0.34) was low.,Conclusions.,The 6MWT showed good reproducibility and known group validity, and can be recommended for use in clinical practice in the studied population. To evaluate individual outcomes after intervention, the 6MWD needs to change by >68,m to be statistically significant. The 6MWD performed by obese children averaged 86% of the distance normal-weight children walked. In obese children, the correlation between 6MWD and estimated VO2max was low, hence the 6MWT cannot substitute a bicycle ergometry test. Copyright © 2008 John Wiley & Sons, Ltd. [source] Insect and wind pollination of an alpine biennial Aconitum gymnandrum (Ranunculaceae)PLANT BIOLOGY, Issue 6 2009Y. W. Duan Abstract Wind pollination can provide reproductive insurance for animal-pollinated dioecious plants in the absence of available pollinators, but combinations of insect and wind pollination (ambophily) have rarely been studied in hermaphrodite herbs. We examined the stable occurrence of insect pollination and wind pollination over 4 years in a population of a biennial Aconitum species (A. gymnandrum) with actinomorphic and degenerate sepals. The total frequency of visits of two bumblebee species showed no distinct fluctuations in the studied population among the 4 years. However, seed production of netted flowers after emasculation indicated wind pollination had occurred. The seed number of bagged flowers with one visit by bumblebees was significantly less than that of netted flowers after one visit, or in control flowers. Both seed number and fruit set of netted flowers were significantly lower than in control flowers. These results suggest that wind pollination provides supplementary pollen to unvisited and/or once-visited flowers, but accounts for only a small amount of seed production compared to bumblebee pollination in natural conditions. Such a combination of insect and wind pollination might play an important role in maintaining sexual reproduction of this biennial herb, allowing it to persist in arid habitats on the Qinghai-Tibetan Plateau, especially during Quaternary glacial periods when pollinator populations oscillated extensively. [source] Correlation Relationship Assessment between Left Ventricular Hypertrophy Voltage Criteria and Body Mass Index in 41,806 Swiss ConscriptsANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 4 2009Roger Abächerli Ph.D. Introduction: Electrocardiographic criteria for left ventricular hypertrophy (LVH) have been limited by low sensitivity at acceptable levels of specificity. A number of studies have demonstrated that body mass index (BMI) is associated with decreased sensitivity of ECG LVH classification in hypertensive patients. The objective of this study is to investigate the correlation relationship between LVH voltage criteria and BMI in Swiss conscripts. Methods: A database of 41,806 young Swiss people, who underwent compulsory conscription for the Swiss Army, was compiled. Along with other medical data, an ECG was taken. Statistical analyses, such as linear regression and calculation of correlation coefficient, were carried out between LVH voltage criteria and BMI. Results: The mean age in the studied population was 19.2 ± 1.1 years with a median age of 19 years (range from 17 to 38 years). We found an overweight prevalence of 25.1%. The results showed that body habitus had significant association with Sokolow-Lyon voltages. A mean decrease of 13%, 5%, 19%, 14%, and 12% for the five studied Sokolow-Lyon indexes were found between normal range subjects (18.5 , BMI < 25) and obese subjects (25, BMI). Conclusions: Our study confirms the hypothesis that people with higher BMI, a growing section of the population, have lower ECG amplitudes. Therefore, the Sokolow-Lyon voltage criteria may underestimate the presence of LVH for subjects with higher BMI, which is not the case for the Cornell voltage. Our analysis suggests that computerized electrocardiography for the diagnosis of left ventricular hypertrophy based on Sokolow-Lyon voltages should incorporate the BMI factor. [source] Relationship between floral tube length and nectar robbing in Duranta erecta L. (Verbenaceae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009LUIS NAVARRO Although nectar robbing is a common phenomenon in plant species with tubular flowers or flowers with nectar spurs, the potential effect of this illegitimate interaction on plant reproductive success has not received the deserved attention. In the present study, we analysed the functional relationship between flower morphology and nectar robbing, and examined the reproductive consequences of the interaction in a population of Duranta erecta (Verbenaceae) on the island of Cuba. The results show that nectar robbing is conducted by the carpenter bees Xylocopa cubaecola and affects up to 44% of flowers in the studied population. However, not all the flowers have the same probability of being robbed. The chance of flowers being robbed increases with flower length and flower diameter. Moreover, nectar robbing significantly decreases the chance that flowers will set fruit. Also, the impact of nectar robbing on the probability of flowers to set fruits is dependent on the plant. We suggest that nectar robbing may represent an opposite selective force that balances the selection for longer corollas often imposed by pollinators specializing in visiting tubular flowers. Such a relationship with nectar robbers would have obvious implications for the evolution of tubular or closed flowers. This preliminary finding deserves further research in light of the ecological and evolutionary consequences of nectar robbing in tubular flowers. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 392,398. [source] Insulin sensitivity, VO2max and body composition in severely obese Swedish children and adolescentsACTA PAEDIATRICA, Issue 1 2009Gunilla Morinder Abstract Aim: The aim of this study was to identify relationships between insulin sensitivity (SI), cardiorespiratory fitness and body composition in severely obese Swedish children and adolescents. Methods: Two hundred and twenty-eight obese children (119 girls, 8,16 years, body mass index (BMI) 23.2,57.0 kg/m2) performed a frequently sampled intravenous glucose tolerance test (FSIVGTT), a submaximal bicycle ergometry test and a dual-energy X-ray absorptiometry (DEXA). Results: Mean SI (SD) was 0.38 (0.32) (×10,5/min/pM). SI correlated positively with relative body mass (BM) VO2max (r = 0.42) (p < 0.001), relative fat-free mass (FFM) VO2max (r = 0.36) (p < 0.001) and negatively with body mass index standard deviation score (BMI SDS) (r =,0.22) (p = 0.001). SI did not correlate with percent body fat (r =,0.01) and absolute VO2max (r = 0.01). In multiple regression analyses with SI as dependent variable, VO2max and body composition, together with gender, age and Tanner stage, explained 20,26% of the variance. Conclusion: Relative (BM) VO2max and relative (FFM) VO2max were stronger predictors of SI than percent body fat in severely obese children and adolescents. The study confirms that cardiorespiratory fitness is of importance for the metabolic syndrome in the studied population. Efforts to improve SI should include physical activity targeting cardiorespiratory fitness also in severely obese children and adolescents. [source] Growth in relation to microclimatic conditions and physiological characteristics of four Lobaria pulmonaria populations in two contrasting habitatsECOGRAPHY, Issue 1 2004Gisela Gaio-Oliveira The aim of the present study was to compare the physiological characteristics of various populations of the lichen Lobaria pulmonaria in Portugal and Sweden. For this, indirect markers of algal (photobiont) and fungal (mycobiont) activity were measured, as well as their CO2 gasexchange characteristics. Microclimatic conditions and the lichens growth performance in the two countries were compared using reciprocal transplantation. Two populations of L. pulmonaria represented each country: one collected from forest interior conditions and one from forest edge habitats. A non-transplanted "wild" population was also studied in each country, in order to evaluate any transplantation effects per se. The main hypothesis were that; 1) growth should be faster in Portugal due to higher light availability; 2) the energy use efficiency of lichen biomass gain should be similar for the native populations in their respective native habitat; 3) if the lichens were able to adapt to the environmental conditions in the foreign habitat this should be revealed as similar growth rates among all thalli transplanted at the same site, regardless of their origin. Physiologically, the Portuguese and Swedish populations were very similar, both concerning their CO2 gas exchange characteristics and distribution of resources between photo- and mycobiont tissue. Environmental conditions were more advantageous for L. pulmonaria growth in Portugal, i.e. higher photon flux densities and ambient temperatures when the lichens were wet and active, and a lower fraction of the active time occurring in darkness. However, despite similar physiological characteristics of all the studied populations, the Swedish lichens were not able to grow as well in Portugal as the native, while all populations had similarly low growth rates in Sweden. [source] Among- and within-population variability in tolerance to cadmium stress in natural populations of Daphnia magna: Implications for ecological risk assessmentENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2002Carlos Barata Abstract Previous attempts to test the hypothesis that laboratory selection of isogenetic populations can produce test organisms with a significantly increased mean tolerance to toxic substances have failed. One possible explanation for such failure is that the tolerance of laboratory populations is largely constrained by their origins (were the source populations composed of tolerant genotypes?). To address this question, among- and within-population variability in stress tolerance was assessed by calculating the variance in individual fitness and longevity across a cadmium gradient (0,10 ,g/L). The study employed Daphnia magna clones from four geographically separate European populations. Results revealed significant differences in tolerance to lethal levels of toxic stress among populations. The distribution of tolerances within two of the studied populations showed high amounts of genetic variation in tolerance. Genetic relationships between tolerance traits and life history performance under nonstressful environments differed among the studied populations. One population showed significant but low costs associated with tolerance, whereas no costs were associated with tolerance in the other population. These results suggest that laboratory selection will favor individuals with high fitness or reproductive performance under optimal laboratory conditions resulting in laboratory populations with similar or lower tolerance to toxic stress than their original field populations. Given that populations can exhibit high levels of genetic variability in tolerance to toxic stress, minimizing genetic diversity in toxicity tests will increase the uncertainty attendant in extrapolating from the lab to the field. [source] POSTMATING SEXUAL SELECTION: ALLOPATRIC EVOLUTION OF SPERM COMPETITION MECHANISMS AND GENITAL MORPHOLOGY IN CALOPTERYGID DAMSELFLIES (INSECTA: ODONATA)EVOLUTION, Issue 2 2004A. Cordero Rivera Abstract Postmating sexual selection theory predicts that in allopatry reproductive traits diverge rapidly and that the resulting differentiation in these traits may lead to restrictions to gene flow between populations and, eventually, reproductive isolation. In this paper we explore the potential for this premise in a group of damselflies of the family Calopterygidae, in which postmating sexual mechanisms are especially well understood. Particularly, we tested if in allopatric populations the sperm competition mechanisms and genitalic traits involved in these mechanisms have indeed diverged as sexual selection theory predicts. We did so in two different steps. First, we compared the sperm competition mechanisms of two allopatric populations of Calopteryx haemorrhoidalis (one Italian population studied here and one Spanish population previously studied). Our results indicate that in both populations males are able to displace spermathecal sperm, but the mechanism used for sperm removal between both populations is strikingly different. In the Spanish population males seem to empty the spermathecae by stimulating females, whereas in the Italian population males physically remove sperm from the spermathecae. Both populations also exhibit differences in genital morphometry that explain the use of different mechanisms: the male lateral processes are narrower than the spermathecal ducts in the Italian population, which is the reverse in the Spanish population. The estimated degree of phenotypic differentiation between these populations based on the genitalic traits involved in sperm removal was much greater than the differentiation based on a set of other seven morphological variables, suggesting that strong directional postmating sexual selection is indeed the main evolutionary force behind the reproductive differentiation between the studied populations. In a second step, we examined if a similar pattern in genital morphometry emerge in allopatric populations of this and other three species of the same family (Calopteryx splendens, C. virgo and Hetaerina cruentata). Our results suggest that there is geographic variation in the sperm competition mechanisms in all four studied species. Furthermore, genitalic morphology was significantly divergent between populations within species even when different populations were using the same copulatory mechanism. These results can be explained by probable local coadaptation processes that have given rise to an ability or inability to reach and displace spermathecal sperm in different populations. This set of results provides the first direct evidence of intraspecific evolution of genitalic traits shaped by postmating sexual selection. [source] Genetic susceptibility to nasopharyngeal carcinoma within the HLA-A locus in TaiwaneseINTERNATIONAL JOURNAL OF CANCER, Issue 6 2003Cheng-Chan Lu Abstract NPC is an epithelial tumor that is highly prevalent among the southern Chinese. Numerous studies have indicated that specific HLA haplotypes and genes within the HLA complex are associated with NPC. As a first effort to localize the gene responsible for susceptibility, the HLA-A, -B, and -A2 subtypes were examined for their association to NPC. Consistent with previous reports, frequencies of HLA-A2 [OR = 2.50, pc = 0.020 (study population); OR = 3.73, pc = 0.0030 (,40 years old)] were significantly higher in patients with NPC than in healthy controls. Two-locus analysis indicated that A2+B46+ individuals are at greater risk for NPC than A2,B46, individuals in both the population studied and the ,40-year-old group. This, however, may be due to the close linkage of these 2 genes. Moreover, A2+B38+ individuals were at higher risk than A2,B38, individuals in both the population studied and the ,40-year-old group; A2 and B38 are not genetically linked. These findings suggest that B38 or B46 alone cannot confer a high risk of NPC but that, in conjunction with A2, B38 or B46 positivity greatly increases risk. None of 5 A2 subtypes identified from studied populations was significantly associated with NPC. Microsatellite marker D6S211, located 97 kb telomeric to HLA-A, was analyzed for its association with NPC. Allele 4 of D6S211 was significantly associated with NPC (OR = 3.97, pc = 0.0042). These results strongly support the hypothesis that genes associated with susceptibility to NPC in the HLA region are within the HLA-A locus. © 2002 Wiley-Liss, Inc. [source] Preliminary estimates of the population parameters of major fish species in Lake Ayamé I (Bia basin; Côte d'Ivoire)JOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2010L. Tah Summary Length frequency data collected from artisanal fisheries in Lake Ayamé I (Côte d'Ivoire) from August 2004 to 2005 were analysed with Fisat software using the Elefan package to estimate the population parameters of 11 fish species. Asymptotic values for total length (L,) ranged from 20.5 cm for Brycinus imberi to 78 cm for Mormyrops anguilloides. Growth rates (k) varied from 0.24 year,1 for Chrysichthys nigrodigitatus to 0.57 year,1 for Hemichromis fasciatus. The growth performance estimates were close to the values found by others authors and reported in FishBase 2008. Fishing mortality (F) and exploitation rate (E) were found to be below optimum levels of exploitation for most fish species. Recruitment was noted as year,round and bimodal for most studied populations. The data sets were limited in most cases, thus this study provides preliminary population parameters only, but for species for which information is scarce. For application in stock assessment, the growth parameters and especially the natural mortality data require further confirmation. [source] Stocking-related patterns of genetic variation at enzymatic loci in south European Atlantic salmon populationsJOURNAL OF FISH BIOLOGY, Issue 2005P. Morán Genetic variation at 24 enzymatic loci was investigated in eight south European Atlantic salmon populations from the rivers Nivelle, Cares, Sella, Narcea, Esva, Navia, Porcia and Eo. In these rivers, management based on supplementation of native populations with foreign stocks was carried out for more than one decade. Population genetic patterns expressed in terms of allele frequencies, mean heterozygosity and conformity to Hardy-Weinberg equilibrium, were significantly different between populations. Relevant temporal changes of genetic variability were reported. Evidence that foreign stocking has disturbed the genetic patterns of some of the studied populations is presented. [source] Patterns of genetic variation do not correlate with geographical distance in the reef-building coral Pocillopora meandrina in the South PacificMOLECULAR ECOLOGY, Issue 7 2005H. MAGALON Abstract Dispersal may be a critical factor in the ability of reef-building corals to recover after major disturbances. We studied patterns of geographical structure using four microsatellite markers in seven South Pacific populations of Pocillopora meandrina, a major coral species from Polynesia. Variation within populations showed evidence of heterozygote deficiency. Genetic differentiation between populations was detected at a large scale (2000 km) between the Tonga and the Society Islands. Within the Society Islands, four of the five studied populations from Bora Bora, Moorea and Tahiti were not significantly different from each other. Unexpectedly, one of the three populations surveyed in Moorea was genetically different from the other two populations of this island (that were 5 and 10 km apart), and from the populations of the other two surveyed islands in this archipelago. We cannot rule out the possibility that this pattern is an equilibrium state, whereby short-range dispersal is locally more differentiating than long-range dispersal, as has been suggested by similar patterns reported in other studies. An alternative explanation that is globally consistent with all observations is that this is the signature of a large-scale destruction event, as for instance a bleaching event, followed by the recent restoration of populations by new colonists. [source] DNA barcoding in Tardigrada: the first case study on Macrobiotus macrocalix Bertolani & Rebecchi 1993 (Eutardigrada, Macrobiotidae)MOLECULAR ECOLOGY RESOURCES, Issue 3 2009MICHELE CESARI Abstract Morphological and molecular studies on a tardigrade species have been carried out to verify the possibility of using a DNA barcoding approach for species identification in this phylum. Macrobiotus macrocalix Bertolani & Rebecchi, 1993 was chosen as the test species since it belongs to a group of species in which the taxonomy is quite problematic. Animals and eggs belonging to three Italian and one Swedish populations have been investigated. Both morphological and molecular analyses show that all the populations belong to the same species. The low genetic distances recorded among the studied populations (0.3,1.0%) and the high genetic distance (15.9,16.3%) between these populations and a closely related species confirm the possibility of identifying a specimen of this species by its cytochrome oxidase subunit I sequence. Data from other authors support our results indicating that DNA barcoding can be applied to tardigrades. With our protocols, we have obtained voucher specimens that enable us to show a correspondence between morphology and molecular data. [source] Polymorphic Alu insertions in five North-West Italian populationsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 4 2007A. Santovito We analyzed the frequencies of eight human polymorphic Alu insertion loci in population samples from five towns in North-West Italy: Postua, Cavaglià, Biella, Torino, and Genova. All loci under scrutiny were found to be polymorphic in all samples, with the two exceptions of locus A25 in Postua, which was fixed for the absence of the Alu element, and APO in Genova, where the Alu insertion was fixed. Heterozigosity values were highly variable in all loci. FST values for all loci indicate that most of the variability is found within populations, while between population variability is lower. In the multidimensional scaling (MDS) analysis plot, the studied populations are separated from the main group represented by European populations. The Postua sample is set apart also from neighboring towns as Cavaglià and Biella, confirming previous observations of the demographic isolation of this population. Am. J. Hum. Biol. 19:589,592, 2007. © 2007 Wiley-Liss, Inc. [source] Brief communication: Allelic and haplotypic structure at the DRD2 locus among five North Indian caste populationsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Kallur N. Saraswathy Abstract The dopamine D2 receptor (DRD2) gene, with its known human-specific derived alleles that can facilitate haplotype reconstruction, presents an important locus for anthropological studies. The three sites (TaqIA, TaqIB, and TaqID) of the DRD2 gene are widely studied in various world populations. However, no work has been previously published on DRD2 gene polymorphisms among North Indian populations. Thus, the present study attempts to understand the genetic structure of North Indian upper caste populations using the allele and haplotype frequencies and distribution patterns of the three TaqI sites of the DRD2 gene. Two hundred forty-six blood samples were collected from five upper caste populations of Himachal Pradesh (Brahmin, Rajput and Jat) and Delhi (Aggarwal and Sindhi), and analysis was performed using standard protocols. All three sites were found to be polymorphic in all five of the studied populations. Uniform allele frequency distribution patterns, low heterozygosity values, the sharing of five common haplotypes, and the absence of two of the eight possible haplotypes observed in this study suggest a genetic proximity among the selected populations. The results also indicate a major genetic contribution from Eurasia to North Indian upper castes, apart from the common genetic unity of Indian populations. The study also demonstrates a greater genetic inflow among North Indian caste populations than is observed among South Indian caste and tribal populations. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source] Possible relationship of cranial traumatic injuries with violence in the south-east Iberian Peninsula from the Neolithic to the Bronze AgeAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009S.A. Jiménez-Brobeil Abstract The main aim of this study was to analyze the presence and distribution of cranial trauma, as possible evidence of violence, in remains from the Neolithic to Bronze Age from the SE Iberian Peninsula. The sample contains skulls, crania, and cranial vaults belonging to 410 prehistoric individuals. We also studied 267 crania from medieval and modern times for comparative purposes. All lesions in the prehistoric crania are healed and none of them can be attributed to a specific weapon. In all studied populations, injuries were more frequent in adults than in subadults and also in males than in females, denoting a sexual division in the risk of suffering accidents or intentional violence. According to the archeological record, the development of societies in the SE Iberian Peninsula during these periods must have entailed an increase in conflict. However, a high frequency of cranial traumatic injuries was observed in the Neolithic series, theoretically a less conflictive time, and the lowest frequency was in crania from the 3rd millennium B.C. (Copper Age), which is characterized by the archeologists as a period of increasing violence. The relatively large size and the high rate of injuries in Neolithic crania and the practice of cannibalism are strongly suggestive of episodes of interpersonal or intergroup conflict. The number and distribution of injuries in Bronze Age is consistent with the increase in violence at that time described by most archeologists. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Living on the edge: life-history of olive baboons at Gashaka-Gumti National Park, NigeriaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 4 2009James P. Higham Abstract Baboons are the most successful and ubiquitous African primates, renowned for their behavioral and reproductive flexibility, which enable them to inhabit a wide variety of habitat types. Owing to a number of long-term field studies, comparative behavioral, developmental, demographic, and life-history data are available from several populations, but study sites show a heavy bias toward South and East African savannahs, with little research in West or Central Africa. Life-history data from such areas are important if we are fully to understand the nature of the environmental factors that limit baboon distribution. Here, we present demographic data for olive baboons at Gashaka-Gumti National Park (GGNP), Nigeria, collected from December 2000,February 2006, and use these data to test comparative models of baboon life-history. The GGNP habitat, which includes large areas of rainforest, is an environment in which baboons are little studied, and rainfall is much higher than at previous study sites. GGNP troop size data are presented from censuses, as well as life-history data for two troops, one of which is within the park and wild-feeding (Kwano troop), whereas the other dwells at the park edge, and supplements its diet by crop-raiding (Gamgam troop). Troop sizes at GGNP are small compared with other field sites, but fit within previously suggested ranges for baboons under these climatic conditions. Inter-birth intervals in Kwano troop were long compared with most studied populations, and values were not as predicted by comparative models. Consistent with known effects of food enhancement, Gamgam troop experienced shorter inter-birth intervals and lower infant mortality than Kwano troop. We indicate some possible factors that exclude baboons from true rainforest, and suggest that the clearing of forests in Central and West Africa for agricultural land may allow baboons to extend their range into regions from which they are currently excluded. Am. J. Primatol. 71:293,304, 2009. © 2009 Wiley-Liss, Inc. [source] | ||||||||||||||||||||||||||||