326 research outputs found

    An epidemiological perspective on the future of direct-to-consumer personal genome testing

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    Personal genome testing is offered via the internet directly to consumers. Most tests that are currently offered use data from genome-wide scans to predict risks for multiple common diseases and traits. The utility of these tests is limited, predominantly because they lack predictive ability and clear benefits for disease prevention that are specific for genetic risk groups. In the near future, personal genome tests will likely be based on whole genome sequencing, but will these technological advances increase the utility of personal genome testing? Whole genome sequencing theoretically provides information about the risks of both monogenic and complex diseases, but the practical utility remains to be demonstrated. The utility of testing depends on the predictive ability of the test, the likelihood of actionable test results, and the options available for the reduction of risks. For monogenic diseases, the likelihood of known mutations will be extremely low in the general population and it will be a challenge to recognize new causal variants among all rare variants that are found using sequencing. For complex diseases, the predictive ability of genetic tests will be mainly restricted by the heritability of the disease, but also by the genetic complexity of the disease etiology, which determines the extent to which the heritability can be understood. Given that numerous genetic and non-genetic risk factors interact in the causation of complex diseases, the predictive ability of genetic models will likely remain modest. Personal genome testing will have minimal benefits for individual consumers unless major breakthroughs are made in the near future

    Road and railway verges serve as dispersal corridors for grassland plants

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    The role of linear habitat strips as dispersal corridors is a disputed topic. Reports concerning their significance for animals have been contradictory, and the functions of corridors have been difficult to study in the case of sedentary organisms such as plants. Previous studies on dispersal of plants along corridors have concentrated on a single or a few species at a time. We developed a general method, a generalisation of the binomial test, for considering dispersal or spatial relations of a large group of species. Particularly, we studied the ability of grassland plants to spread along road and railway verges. Our data set consists of plant lists collected at study plots scattered irregularly along road and railway networks. The dispersal ability was assessed by testing whether the species composition at neighbouring sites – measured along roads and railways – reflects spatial dependence within each species. Our result showed that similar combinations of grassland species occurred at neighbouring sites more often than expected in a spatially independent case. We argue that management of verges and spatial autocorrelation of environmental factors were not responsible for the result and thereby we conclude that grassland plants use road and railway corridors for dispersal. This result is encouraging in regards to preservation of grassland plant populations. Although semi-natural and natural grasslands have become scarce, road and railway embankments may partly compensate for this loss, serving as substitute habitats and dispersal routes

    Conservation contracts in habitat protection in southern Finland

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    Demands for additional conservation of forests have been strong in Finland where a remarkable number of threatened species need wooded lands. In the southern half of the country the proportion of strictly protected forestland is as low as 1.1% and three quarters of forests are owned by private individuals and families. In order to promote forest protection on private lands the possibilities of landowners to participate in decision making should be improved. To assess the role of voluntary or incentive-based conservation contracts in protection of privately owned forestlands two existing conservation practices were studied: (1) voluntary establishment of permanent nature reserves and (2) payment of environmental grants that are appropriated for fixed-periods and that compensate for statutory preservation of woodland key habitats. Mean areas and compensation sums associated with sites protected using these two practices were simply compared to each other. Nature reserves were on average larger than key habitat sites. However, in the long run fixed-period environmental grants paid for key habitats provide landowners with higher compensation than that paid for establishing permanent nature reserves. These results are assessed in the light of international discussion on social, economic and ecological factors related to protection of private lands. © 2003 Elsevier Science Ltd. All rights reserved

    Conservation implications of exporting domestic wood harvest to neighboring countries

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    Among wealthy countries, increasing imports of natural resources to allow for unchecked consumption and greater domestic environmental conservation has become commonplace. This practice can negatively affect biodiversity conservation planning if natural resource harvest is merely pushed across political borders. As an example, we focus on the boreal forest ecosystem of Finland and northwest Russia. While the majority of protected forests are in northern Finland, the majority of biodiversity is in southern Finland, where protection is more difficult due to high private ownership, and the effectiveness of functioning conservation networks is more uncertain due to a longer history of land use. In northwest Russia, the current protected areas are inadequate to preserve most of the region’s naturally dynamic and old growth forests. Increased importation of wood from northwest Russia to Finland may jeopardize the long-term viability of species in high diversity conservation areas in both Russia and Finland, through isolating conservation areas and lowering the age of the surrounding forest mosaic. The boreal forest ecosystem of Fennoscandia and northwest Russia would thus be best conserved by a large scale, coordinated conservation strategy that addresses long-term conservation goals and wood consumption, forest industries, logging practices and trade

    Brain mechanisms underlying cue-based memorizing during free viewing of movie Memento

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    How does the human brain recall and connect relevant memories with unfolding events? To study this, we presented 25 healthy subjects, during functional magnetic resonance imaging, the movie 'Memento' (director C. Nolan). In this movie, scenes are presented in chronologically reverse order with certain scenes briefly overlapping previously presented scenes. Such overlapping "key-frames" serve as effective memory cues for the viewers, prompting recall of relevant memories of the previously seen scene and connecting them with the concurrent scene. We hypothesized that these repeating key-frames serve as immediate recall cues and would facilitate reconstruction of the story piece-by-piece. The chronological version of Memento, shown in a separate experiment for another group of subjects, served as a control condition. Using multivariate event-related pattern analysis method and representational similarity analysis, focal fingerprint patterns of hemodynamic activity were found to emerge during presentation of key-frame scenes. This effect was present in higher-order cortical network with regions including precuneus, angular gyrus, cingulate gyrus, as well as lateral, superior, and middle frontal gyri within frontal poles. This network was right hemispheric dominant. These distributed patterns of brain activity appear to underlie ability to recall relevant memories and connect them with ongoing events, i.e., "what goes with what" in a complex story. Given the real-life likeness of cinematic experience, these results provide new insight into how the human brain recalls, given proper cues, relevant memories to facilitate understanding and prediction of everyday life events.Peer reviewe

    Importing Timber, Exporting Ecological Impact

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    Covering 32% of the planet, boreal forests are one of the last relatively intact terrestrial biomes, and are a critical carbon sink in global climate dynamics. Mature and old-growth boreal forests provide a large number of products that are culturally and economically important, from wood-based lumber, pulp, and fuel wood, to numerous nonwood products. Intensive wood harvest and conservation of naturally dynamic intact forests tend to be mutually exclusive; where biodiversity is highly valued, wood harvests are limited or banned outright. The authors of this Policy Forum advise that increasing domestic forest protection without decreasing demand for wood necessitates an increase in foreign imports, which introduces a negative impact on forest biodiversity elsewhere. In some cases, exporting impact across the border may cause negative impacts to boomerang back into the country's protected forests

    Local Versus Centralized Control of Flexbile Loads in Power Grid

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    Head and Neck Cancer Risk Calculator (HaNC-RC) - v.2. Adjustments and addition of symptoms and social history factors.

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    Objectives: Head and neck cancer (HNC) diagnosis through the 2-week wait, urgent suspicion of cancer (USOC) pathway has failed to increase early cancer detection rates in the UK. A head and neck cancer risk calculator (HaNC-RC) has previously been designed to aid referral of high-risk patients to USOC clinics (predictive power: 77%). Our aim was to refine the HaNC-RC to increase its prediction potential. Design: Following sample size calculation, prospective data collection and statistical analysis of referral criteria and outcomes. Setting: Large tertiary care cancer centre in Scotland. Participants: 3531 new patients seen in routine, urgent and USOC head and neck (HaN) clinics. Main outcome measures: Data collected were as follows: demographics, social history, presenting symptoms and signs and HNC diagnosis. Univariate and multivariate regression analysis were performed to identify significant predictors of HNC. Internal validation was performed using 1000 sample bootstrapping to estimate model diagnostics included the area under the receiver operator curve (AUC), sensitivity and specificity. Results: The updated version of the risk calculator (HaNC-RC v.2) includes age, gender, unintentional weight loss, smoking, alcohol, positive and negative symptoms and signs of HNC. It has achieved an AUC of 88.6% with two recommended triage referral cut-offs to USOC (cut-off: 7.1%; sensitivity: 85%, specificity: 78.3%) or urgent clinics (cut-off: 2.2%; sensitivity: 97.1%; specificity of 52.9%). This could redistribute cancer detection through USOC clinics from the current 60.9%–85.2%, without affecting total numbers seen in each clinical setting. Conclusions: The use of the HaNC-RC v.2 has a significant potential in both identifying patients at high risk of HNC early thought USOC clinics but also improving health service delivery practices by reducing the number of inappropriately urgent referrals

    Breaking Yield Barrier in Pigeonpea through Hybrid Breeding

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    Runs of homozygosity do not influence survival to old age

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    Runs of homozygosity (ROH) are extended tracts of adjacent homozygous single nucleotide polymorphisms (SNPs) that are more common in unrelated individuals than previously thought. It has been proposed that estimating ROH on a genome-wide level, by making use of the genome-wide single nucleotide polymorphism (SNP) data, will enable to indentify recessive variants underlying complex traits. Here, we examined ROH larger than 1.5 Mb individually and in combination for association with survival in 5974 participants of the Rotterdam Study. In addition, we assessed the role of overall homozygosity, expressed as a percentage of the autosomal genome that is in ROH longer than 1.5 Mb, on survival during a mean follow-up period of 12 years. None of these measures of homozygosity was associated with survival to old age
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