Patterns of sperm precedence and predictors of paternity in the Trinidadian guppy.
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Despite its widespread occurrence in animals, sperm competition has been studied in a limited range of taxa. Among the most neglected groups in this respect are internally fertilizing fish in which virtually nothing is known about the dynamics of sperm competition. In this study, we examined the outcome of sperm competition when virgin female guppies mated with two males. Behavioural cues were used to ensure that each male mated once (with female cooperation) and that sperm were successfully inseminated at copulation. Two polymorphic microsatellite loci were used to estimate the proportion of offspring sired by the second male (P2) and the results revealed a bimodal distribution with either first or (more often) second male priority The observed P2 distribution differed from that expected under the 'fair raffle' model of sperm competition. Random sperm mixing is therefore unlikely to account for the observed variance in P2 in this study. A further aim of our study was to identify predictors of male reproductive success. Using logistic linear modelling, we found that the best predictors of paternity were time to remating and the difference in courtship display rate between first and second males. Males that mated quickly and performed relatively high numbers of sigmoid displays obtained greater parentage than their slower and less vigorous counterparts. Since females are attracted to high-displaying males, our results suggest that female choice may facilitate sperm competition and/or sperm choice in guppies. (+info)
A longitudinal study on enteropathogenic infections of livestock in Trinidad.
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A longitudinal study was conducted on selected livestock farms to determine the prevalence of enteropathogens in diarrhoeic and non-diarrhoeic animals. The enteropathogens assayed from faecal samples and rectal swabs were bacteria (Escherichia coli, Campylobacter spp. Salmonella spp. and Yersinia enterocolitica), parasites (coccidia, gastrointestinal nematodes and Cryptosporidium spp.) and viruses (group A rotavirus and parvovirus). The prevalence of the enteropathogens in various animal species was related to age and month of the year. Generally, younger animals presented a higher prevalence of infection by enteropathogens than older animals while most infections occurred between the months of January and April. (+info)
Bacteriuria in the elderly population in a developing country.
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Among 1470 elderly hospitalized and nonhospitalized people, 566 cases of bacteriuria were identified. There were 663 men (41.5% with bacteriuria) and 807 women (36.0% with bacteriuria). The overall prevalence of bacteriuria was 38.5%. More than 90% of the isolates were gram-negative organisms with Proteus species being the predominant pathogen among men, with 68.1% seen among inpatients. Escherichia coli was the main pathogen in women, with 62.0% recovered from inpatients. Catheterization was seen most commonly among non-hospitalized males with outflow obstruction. Catheter care in this population is often performed at home by these men who either refuse prostate surgery, are not fit for surgery, or are awaiting surgery. Polymicrobic bacteriuria was identified more frequently (approximately 60%) among the catheterized group. Of the 440 gram-negative bacilli recovered as single organisms, 352 (80.0%) were resistant to ampicillin, cephalothin, and tetracycline, whereas 229 (52.0%) were resistant to co-trimoxazole. The most effective antibiotics (in increasing order of sensitivity; 80% - 100%) were augmentin, nalidixic acid, cefuroxime, gentomicin, and ciprofloxacin. No mortality due to bacteremia complicated by bacteriuria was observed during the study period. (+info)
The prevalence of Chlamydia trachomatis in fresh tissue specimens from patients with ectopic pregnancy or tubal factor infertility as determined by PCR and in-situ hybridisation.
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The prevalence of chlamydial DNA determined by PCR and in-situ hybridisation (ISH) in fresh tissue specimens (endometrium, fallopian tube and ovary) was investigated in 33 women presenting with ectopic pregnancy (EP), 14 women with tubal factor infertility (TFI) and 50 control patients from the UK and the West Indies. In the UK EP group, chlamydial DNA was detected by PCR in 56% of patients; similar results were found in the Trinidad EP group (67%). In the TFI group, chlamydial DNA was detected in (71%) of patients by PCR. The detection of Chlamydia trachomatis DNA by ISH was highest in the TFI group (43%). Women presenting with EP and TFI showed evidence of previous or current genital C. trachomatis infection, underlining the importance of this microorganism in the development of these conditions. Importantly, chlamydial DNA could be detected in DNA preparations from the endometrium, fallopian tube and ovary of EP and TFI patients at the time of surgery. (+info)
Overweight, obesity and skinfold thicknesses of children of African or Indian descent in Trinidad and Tobago.
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BACKGROUND: To evaluate distribution of body mass index (BMI) and subcutaneous fat in children of African or Indian subcontinent descent living in Trinidad and Tobago. METHODS: A cross-sectional survey was carried out in a nationally representative sample of 66 government schools. Measurements were made of children's heights, weights, triceps and subscapular skinfold thicknesses. Data were analysed by sex and ethnic group and comparison was made with international standards for overweight and obesity and with British (1990) reference curves for BMI. RESULTS: Data were analysed for 5688/6731 (85%) eligible children including 1934 Afro-Trinidadian, 1689 Indo-Trinidadian, and 1794 of mixed ethnicity. Afro-Trinidadian and mixed children were taller, but Indo-Trinidadian children were shorter than reference. Values for BMI were lower than reference: mean standard deviation score (SDS), (95% confidence interval) Afro-Trinidadian -0.34 (-0.39 to -0.28), Indo-Trinidadian -1.32 (-1.39 to -1.25), mixed -0.67 (-0.74 to -0.61). Overall 486 (8.5%, 7.8 to 9.3%) of children were overweight and 138 (2.4%, 2.0 to 2.9%) were obese. Triceps skinfold thickness values were lower than reference (-0.45, -0.48 to -0.42 SDS) but subscapular skinfold thicknesses were higher (0.45, 0.43 to 0.47 SDS). Higher BMI were associated with higher BMI in the child's parents, higher reported birthweight, older age of the child's mother, smaller family size, and with higher maternal educational attainment. CONCLUSIONS: Overweight was prevalent and distribution of subcutaneous fat was central. Work is needed to determine whether these findings are associated with adult patterns of fat distribution and metabolic abnormalities. (+info)
Medicinal and ethnoveterinary remedies of hunters in Trinidad.
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BACKGROUND: Ethnomedicines are used by hunters for themselves and their hunting dogs in Trinidad. Plants are used for snakebites, scorpion stings, for injuries and mange of dogs and to facilitate hunting success. RESULTS: Plants used include Piper hispidum, Pithecelobium unguis-cati, Bauhinia excisa, Bauhinia cumanensis, Cecropia peltata, Aframomum melegueta, Aristolochia rugosa, Aristolochia trilobata, Jatropha curcas, Jatropha gossypifolia, Nicotiana tabacum, Vernonia scorpioides, Petiveria alliacea, Renealmia alpinia, Justicia secunda, Phyllanthus urinaria,Phyllanthus niruri,Momordica charantia, Xiphidium caeruleum, Ottonia ovata, Lepianthes peltata, Capsicum frutescens, Costus scaber, Dendropanax arboreus, Siparuma guianensis, Syngonium podophyllum, Monstera dubia, Solanum species, Eclipta prostrata, Spiranthes acaulis, Croton gossypifolius, Barleria lupulina, Cola nitida, Acrocomia ierensis (tentative ID). CONCLUSION: Plant use is based on odour, and plant morphological characteristics and is embedded in a complex cultural context based on indigenous Amerindian beliefs. It is suggested that the medicinal plants exerted a physiological action on the hunter or his dog. Some of the plants mentioned contain chemicals that may explain the ethnomedicinal and ethnoveterinary use. For instance some of the plants influence the immune system or are effective against internal and external parasites. Plant baths may contribute to the health and well being of the hunting dogs. (+info)
Natural killer cell immunoglobulin-like receptor (KIR) locus profiles in African and South Asian populations.
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Natural killer (NK) and some T cells express killer cell immunoglobulin-like receptors (KIRs), which interact with HLA class I expressed by target cells and consequently regulate cytolytic activity. The number of KIR loci can vary and so a range of genetic profiles is observed. We have determined the KIR genetic profiles from one African (n = 62) and two South Asian (n = 108, n = 78) populations. Several of the KIRs are present at significantly different frequencies between the two major ethnic groups (eg KIR2DS4 gene frequency 0.82 African, 0.47 S Asian. Pc < 1 x 10(-6)) and this is due to uneven distribution of two KIR haplotype families 'A' and 'B'. All three populations described here displayed a greater degree of diversity of KIR genetic profiles than other populations investigated, which indicates further complexity of underlying haplotypes; in this respect we describe two individuals who appear homozygous for a large deletion including the previously ubiquitous 2DL4. We have also reanalysed three populations that we studied previously, for the presence of a KIR which is now known to be an indicator of the 'B' haplotype. South Asians had the highest overall frequencies of all KIR loci characteristic of 'B' haplotypes (Pc < 0.0001 to < 0.004). Furthermore, gene frequency independent deviances in the linkage disequilibrium were apparent between populations. (+info)
Sources of stress and psychological disturbance among dental students in the West Indies.
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The aim of this study was to investigate sources of stress and psychological disturbance in dental students across the five years of undergraduate study at a dental school in Trinidad. Eighty-three percent of students completed a modified version of the Dental Environment Stress questionnaire (DES) and the Brief Symptom Inventory (BSI). On a scale ranging from 0 (not stressful) to 5 (highly stressful), overall mean DES scores for each of the five years of study were 1.58, 1.83, 2.65, 2.39, and 2.61 respectively, suggesting that levels of stress increase over the five years with a noticeable spike at the transition between the preclinical and clinical phases. Significant differences were found between specific stressors across the five years of study. Seven specific stressors and the stressor domains of Academic work and Clinical factors were more stressful for female students (t-test p < 0.05). The Global Severity Index of the BSI indicated that 54.8 percent of males and 44.2 percent of females were in the clinical range indicating significant psychological disturbance. Psychological disturbance was significantly associated with stress levels for male students (Spearmans rank correlation r = 0.56; p < 0.001), but not generally for female students. Further development is needed of dental educational programs that enhance students' psychosocial well-being. (+info)