179 research outputs found

    Genome-culture coevolution promotes rapid divergence of killer whale ecotypes.

    Get PDF
    Analysing population genomic data from killer whale ecotypes, which we estimate have globally radiated within less than 250,000 years, we show that genetic structuring including the segregation of potentially functional alleles is associated with socially inherited ecological niche. Reconstruction of ancestral demographic history revealed bottlenecks during founder events, likely promoting ecological divergence and genetic drift resulting in a wide range of genome-wide differentiation between pairs of allopatric and sympatric ecotypes. Functional enrichment analyses provided evidence for regional genomic divergence associated with habitat, dietary preferences and post-zygotic reproductive isolation. Our findings are consistent with expansion of small founder groups into novel niches by an initial plastic behavioural response, perpetuated by social learning imposing an altered natural selection regime. The study constitutes an important step towards an understanding of the complex interaction between demographic history, culture, ecological adaptation and evolution at the genomic level

    Use of dietary supplements by cardiologists, dermatologists and orthopedists: report of a survey

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Dietary supplements are regularly used by a majority of the American population, and usage by health professionals is also common. There is considerable interest in usage patterns within the population and in the reasons for using dietary supplements. The "Life...supplemented" Healthcare Professionals 2008 Impact Study (HCP Impact Study) surveyed usage of dietary supplements by physicians in three specialties: cardiology, dermatology, and orthopedics.</p> <p>Methods</p> <p>The HCP Impact Study was conducted online by Ipsos Public Affairs for the Council for Responsible Nutrition (CRN), a trade association of the dietary supplement industry. Respondents were 900 physicians, including 300 each from three specialties - cardiology, dermatology, and orthopedics.</p> <p>Results</p> <p>Fifty-seven percent of cardiologists said they use dietary supplements at least occasionally, as did 75% of dermatologists and 73% of orthopedists. The product most commonly reported to be used was a multivitamin, but over 25% in each specialty said they used omega-3 fatty acids and over 20% said they used some botanical supplements. Regular dietary supplement use was reported by 37% of cardiologists, 59% of dermatologists, and 50% of orthopedists. Seventy-two percent of cardiologists, 66% of dermatologists, and 91% of orthopedists reported recommending dietary supplements to their patients. The primary reason given for recommending dietary supplements to patients was for heart health or lowering cholesterol for the cardiologists; benefits for skin, hair and nails for the dermatologists; and bone and joint health for the orthopedists.</p> <p>Conclusions</p> <p>Reported dietary supplement use was relatively common in this sample of physicians, and when they recommended dietary supplements to patients, they tended to do so for reasons related to their specialty.</p

    Can an Integrated Approach Reduce Child Vulnerability to Anaemia? Evidence from Three African Countries.

    Get PDF
    Addressing the complex, multi-factorial causes of childhood anaemia is best done through integrated packages of interventions. We hypothesized that due to reduced child vulnerability, a "buffering" of risk associated with known causes of anaemia would be observed among children living in areas benefiting from a community-based health and nutrition program intervention. Cross-sectional data on the nutrition and health status of children 24-59 mo (N = 2405) were obtained in 2000 and 2004 from program evaluation surveys in Ghana, Malawi and Tanzania. Linear regression models estimated the association between haemoglobin and immediate, underlying and basic causes of child anaemia and variation in this association between years. Lower haemoglobin levels were observed in children assessed in 2000 compared to 2004 (difference -3.30 g/L), children from Tanzania (-9.15 g/L) and Malawi (-2.96 g/L) compared to Ghana, and the youngest (24-35 mo) compared to oldest age group (48-59 mo; -5.43 g/L). Children who were stunted, malaria positive and recently ill also had lower haemoglobin, independent of age, sex and other underlying and basic causes of anaemia. Despite ongoing morbidity, risk of lower haemoglobin decreased for children with malaria and recent illness, suggesting decreased vulnerability to their anaemia-producing effects. Stunting remained an independent and unbuffered risk factor. Reducing chronic undernutrition is required in order to further reduce child vulnerability and ensure maximum impact of anaemia control programs. Buffering the impact of child morbidity on haemoglobin levels, including malaria, may be achieved in certain settings

    Milk feeding, solid feeding, and obesity risk:a review of the relationships between early life feeding practices and later adiposity

    Get PDF
    Childhood obesity is a major health issue with associated ill-health consequences during childhood and into later adolescence and adulthood. Given that eating behaviors are formed during early childhood, it is important to evaluate the relationships between early life feeding practices and later child adiposity. This review describes and evaluates recent literature exploring associations between child weight and the mode of milk feeding, the age of introducing solid foods and caregivers’ solid feeding practices. There are many inconsistencies in the literature linking early life feeding to later obesity risk and discrepancies may be related to inconsistent definitions, or a lack of control for confounding variables. This review summarizes the literature in this area and identifies the need for large scale longitudinal studies to effectively explore how early life feeding experiences may interact with each other and with nutritional provision during later childhood to predict obesity risk

    Drivers of population structure of the bottlenose dolphin (Tursiops truncatus) in the Eastern Mediterranean Sea

    Get PDF
    The drivers of population differentiation in oceanic high dispersal organisms, have been crucial for research in evolutionary biology. Adaptation to different environments is commonly invoked as a driver of differentiation in the oceans, in alternative to geographic isolation. In this study, we investigate the population structure and phylogeography of the bottlenose dolphin (Tursiops truncatus) in the Mediterranean Sea, using microsatellite loci and the entire mtDNA control region. By further comparing the Mediterranean populations with the well described Atlantic populations, we addressed the following hypotheses: (1) bottlenose dolphins show population structure within the environmentally complex Eastern Mediterranean Sea; (2) population structure was gained locally or otherwise results from chance distribution of preexisting genetic structure; (3) strong demographic variations within the Mediterranean basin have affected genetic variation sufficiently to bias detected patterns of population structure. Our results suggest that bottlenose dolphin exhibits population structures that correspond well to the main Mediterranean oceanographic basins. Furthermore, we found evidence for fine scale population division within the Adriatic and the Levantine seas. We further describe for the first time, a distinction between populations inhabiting pelagic and coastal regions within the Mediterranean. Phylogeographic analysis suggests that current genetic structure, results mostly from stochastic distribution of Atlantic genetic variation, during a recent postglacial expansion. Comparison with Atlantic mtDNA haplotypes, further suggest the existence of a metapopulation across North Atlantic/Mediterranean, with pelagic regions acting as source for coastal environments

    Impact of Schistosome Infection on Plasmodium falciparum Malariometric Indices and Immune Correlates in School Age Children in Burma Valley, Zimbabwe

    Get PDF
    A group of children aged 6–17 years was recruited and followed up for 12 months to study the impact of schistosome infection on malaria parasite prevalence, density, distribution and anemia. Levels of cytokines, malaria specific antibodies in plasma and parasite growth inhibition capacities were assessed. Baseline results suggested an increased prevalence of malaria parasites in children co-infected with schistosomiasis (31%) compared to children infected with malaria only (25%) (p = 0.064). Moreover, children co-infected with schistosomes and malaria had higher sexual stage geometric mean malaria parasite density (189 gametocytes/µl) than children infected with malaria only (73/µl gametocytes) (p = 0.043). In addition, a larger percentage of co-infected children (57%) had gametocytes as observed by microscopy compared to the malaria only infected children (36%) (p = 0.06). There was no difference between the two groups in terms of the prevalence of anemia, which was approximately 64% in both groups (p = 0.9). Plasma from malaria-infected children exhibited higher malaria antibody activity compared to the controls (p = 0.001) but was not different between malaria and schistosome plus malaria infected groups (p = 0.44) and malaria parasite growth inhibition activity at baseline was higher in the malaria-only infected group of children than in the co-infected group though not reaching statistical significance (p = 0.5). Higher prevalence and higher mean gametocyte density in the peripheral blood may have implications in malaria transmission dynamics during co-infection with helminths

    Vocalisations of Killer Whales (Orcinus orca) in the Bremer Canyon, Western Australia

    Get PDF
    To date, there has been no dedicated study in Australian waters on the acoustics of killer whales. Hence no information has been published on the sounds produced by killer whales from this region. Here we present the first acoustical analysis of recordings collected off the Western Australian coast. Underwater sounds produced by Australian killer whales were recorded during the months of February and March 2014 and 2015 in the Bremer Canyon in Western Australia. Vocalisations recorded included echolocation clicks, burst-pulse sounds and whistles. A total of 28 hours and 29 minutes were recorded and analysed, with 2376 killer whale calls (whistles and burst-pulse sounds) detected. Recordings of poor quality or signal-to-noise ratio were excluded from analysis, resulting in 142 whistles and burst-pulse vocalisations suitable for analysis and categorisation. These were grouped based on their spectrographic features into nine Bremer Canyon (BC) "call types". The frequency of the fundamental contours of all call types ranged from 600 Hz to 29 kHz. Calls ranged from 0.05 to 11.3 seconds in duration. Biosonar clicks were also recorded, but not studied further. Surface behaviours noted during acoustic recordings were categorised as either travelling or social behaviour. A detailed description of the acoustic characteristics is necessary for species acoustic identification and for the development of passive acoustic tools for population monitoring, including assessments of population status, habitat usage, migration patterns, behaviour and acoustic ecology. This study provides the first quantitative assessment and report on the acoustic features of killer whales vocalisations in Australian waters, and presents an opportunity to further investigate this little-known population

    Whistle communication in mammal-eating killer whales (Orcinus orca): further evidence for acoustic divergence between ecotypes

    Get PDF
    Public signaling plays an important role in territorial and sexual displays in animals; however, in certain situations, it is advantageous to keep signaling private to prevent eavesdropping by unintended receivers. In the northeastern Pacific, two populations of killer whales (Orcinus orca), fish-eating “resident” killer whales and mammal-eating “transient” killer whales, share the same habitat. Previous studies have shown that residents use whistles as private signals during close-range communication, where they probably serve to coordinate behavioral interactions. Here, we investigated the whistling behavior of mammal-eating killer whales, and, based on divergent social structures and social behaviors between residents and transients, we predicted to find differences in both whistle usage and whistle parameters. Our results show that, like resident killer whales, transients produce both variable and stereotyped whistles. However, clear differences in whistle parameters between ecotypes show that the whistle repertoire of mammal-eating killer whales is clearly distinct from and less complex than that of fish-eating killer whales. Furthermore, mammal-eating killer whales only produce whistles during “milling after kill” and “surface-active” behaviors, but are almost completely silent during all other activities. Nonetheless, whistles of transient killer whales may still serve a role similar to that of resident killer whales. Mammal-eating killer whales seem to be under strong selection to keep their communication private from potential prey (whose hearing ranges overlap with that of killer whales), and they appear to accomplish this mainly by restricting vocal activity rather than by changes in whistle parameters

    Multiple Sclerosis Susceptibility-Associated SNPs Do Not Influence Disease Severity Measures in a Cohort of Australian MS Patients

    Get PDF
    Recent association studies in multiple sclerosis (MS) have identified and replicated several single nucleotide polymorphism (SNP) susceptibility loci including CLEC16A, IL2RA, IL7R, RPL5, CD58, CD40 and chromosome 12q13–14 in addition to the well established allele HLA-DR15. There is potential that these genetic susceptibility factors could also modulate MS disease severity, as demonstrated previously for the MS risk allele HLA-DR15. We investigated this hypothesis in a cohort of 1006 well characterised MS patients from South-Eastern Australia. We tested the MS-associated SNPs for association with five measures of disease severity incorporating disability, age of onset, cognition and brain atrophy. We observed trends towards association between the RPL5 risk SNP and time between first demyelinating event and relapse, and between the CD40 risk SNP and symbol digit test score. No associations were significant after correction for multiple testing. We found no evidence for the hypothesis that these new MS disease risk-associated SNPs influence disease severity

    Altered miRNA expression network in locus coeruleus of depressed suicide subjects

    Get PDF
    Norepinephrine (NE) is produced primarily by neurons in the locus coeruleus (LC). Retrograde and ultrastructural examinations reveal that the core of the LC and its surrounding region receives afferent projections from several brain areas which provide multiple neurochemical inputs to the LC with changes in LC neuronal firing, making it a highly coordinated event. Although NE and mediated signaling systems have been studied in relation to suicide and psychiatric disorders that increase the risk of suicide including depression, less is known about the corresponding changes in molecular network within LC. In this study, we examined miRNA networks in the LC of depressed suicide completers and healthy controls. Expression array revealed differential regulation of 13 miRNAs. Interaction between altered miRNAs and target genes showed dense interconnected molecular network. Functional clustering of predicated target genes yielded stress induced disorders that collectively showed the complex nature of suicidal behavior. In addition, 25 miRNAs were pairwise correlated specifically in the depressed suicide group, but not in the control group. Altogether, our study revealed for the first time the involvement of LC based dysregulated miRNA network in disrupting cellular pathways associated with suicidal behavior
    corecore