643 research outputs found
Organic farming and biodiversity - the impact of organic farming on nature
Organic farming is generally acknowledged for its positive effects on biodiversity and other landscape services. However, the intensity of farming has changed significantly through the last decade as ranks of traditional holistic organic farmers have been joined by much more economically-driven new organic farmers. At the same time there have also been steady improvements in farming methodology and crop types resulting in efficiency in organic farming which can often rival its conventional counterparts. Therefore, large variations occur between organic farms
Mutation screening of melatonin-related genes in patients with autism spectrum disorders
<p>Abstract</p> <p>Background</p> <p>One consistent finding in autism spectrum disorders (ASD) is a decreased level of the pineal gland hormone melatonin and it has recently been demonstrated that this decrease to a large extent is due to low activity of the acetylserotonin O-methyltransferase (ASMT), the last enzyme in the melatonin synthesis pathway. Moreover, mutations in the <it>ASMT </it>gene have been identified, including a splice site mutation, that were associated with low ASMT activity and melatonin secretion, suggesting that the low ASMT activity observed in autism is, at least partly, due to variation within the <it>ASMT </it>gene.</p> <p>Methods</p> <p>In the present study, we have investigated all the genes involved in the melatonin pathway by mutation screening of <it>AA-NAT </it>(arylalkylamine N-acetyltransferase), <it>ASMT, MTNR1A, MTNR1B </it>(melatonin receptor 1A and 1B) and <it>GPR50 </it>(G protein-coupled receptor 50), encoding both synthesis enzymes and the three main receptors of melatonin, in 109 patients with autism spectrum disorders (ASD). A cohort of 188 subjects from the general population was used as a comparison group and was genotyped for the variants identified in the patient sample.</p> <p>Results</p> <p>Several rare variants were identified in patients with ASD, including the previously reported splice site mutation in <it>ASMT </it>(IVS5+2T>C). Of the variants affecting protein sequence, only the V124I in the <it>MTNR1B </it>gene was absent in our comparison group. However, mutations were found in upstream regulatory regions in three of the genes investigated, <it>ASMT, MTNR1A</it>, and <it>MTNR1B</it>.</p> <p>Conclusions</p> <p>Our report of another ASD patient carrying the splice site mutation IVS5+2T>C, in <it>ASMT </it>further supports an involvement of this gene in autism. Moreover, our results also suggest that other melatonin related genes might be interesting candidates for further investigation in the search for genes involved in autism spectrum disorders and related neurobehavioral phenotypes. However, further studies of the novel variants identified in this study are warranted to shed light on their potential role in the pathophysiology of these disorders.</p
Økologisk jordbrug som refugier for biodiversitet (Refugia)
• Økologiske marker har mere ukrudtsbiomasse end konventionelle.
• Der er flere blomstrende arter i økologiske hegn end konventionelle forudsat, at der er kontinuitet i den økologiske drift.
• Der er flere små pattedyr i små økologiske biotoper end konventionelle.
• Fjernmålinger fra fly eller satellit, kaldet remote sensing, kan skelne hvilken afgrødetype der dyrkes, samt forekomsten af småbiotoper.
• Uanset driftformen er det vigtigt at inddrage naturhensyn i driften, dvs., at der findes ekstensivt drevne arealer (græsmarker, overdrev, enge) til natur og direkte afsatte arealer til natur
Developing and applying heterogeneous phylogenetic models with XRate
Modeling sequence evolution on phylogenetic trees is a useful technique in
computational biology. Especially powerful are models which take account of the
heterogeneous nature of sequence evolution according to the "grammar" of the
encoded gene features. However, beyond a modest level of model complexity,
manual coding of models becomes prohibitively labor-intensive. We demonstrate,
via a set of case studies, the new built-in model-prototyping capabilities of
XRate (macros and Scheme extensions). These features allow rapid implementation
of phylogenetic models which would have previously been far more
labor-intensive. XRate's new capabilities for lineage-specific models,
ancestral sequence reconstruction, and improved annotation output are also
discussed. XRate's flexible model-specification capabilities and computational
efficiency make it well-suited to developing and prototyping phylogenetic
grammar models. XRate is available as part of the DART software package:
http://biowiki.org/DART .Comment: 34 pages, 3 figures, glossary of XRate model terminolog
Health effects and wind turbines: A review of the literature
<p>Abstract</p> <p>Background</p> <p>Wind power has been harnessed as a source of power around the world. Debate is ongoing with respect to the relationship between reported health effects and wind turbines, specifically in terms of audible and inaudible noise. As a result, minimum setback distances have been established world-wide to reduce or avoid potential complaints from, or potential effects to, people living in proximity to wind turbines. People interested in this debate turn to two sources of information to make informed decisions: scientific peer-reviewed studies published in scientific journals and the popular literature and internet.</p> <p>Methods</p> <p>The purpose of this paper is to review the peer-reviewed scientific literature, government agency reports, and the most prominent information found in the popular literature. Combinations of key words were entered into the Thomson Reuters Web of Knowledge<sup>SM </sup>and the internet search engine Google. The review was conducted in the spirit of the evaluation process outlined in the Cochrane Handbook for Systematic Reviews of Interventions.</p> <p>Results</p> <p>Conclusions of the peer reviewed literature differ in some ways from those in the popular literature. In peer reviewed studies, wind turbine annoyance has been statistically associated with wind turbine noise, but found to be more strongly related to visual impact, attitude to wind turbines and sensitivity to noise. To date, no peer reviewed articles demonstrate a direct causal link between people living in proximity to modern wind turbines, the noise they emit and resulting physiological health effects. If anything, reported health effects are likely attributed to a number of environmental stressors that result in an annoyed/stressed state in a segment of the population. In the popular literature, self-reported health outcomes are related to distance from turbines and the claim is made that infrasound is the causative factor for the reported effects, even though sound pressure levels are not measured.</p> <p>Conclusions</p> <p>What both types of studies have in common is the conclusion that wind turbines can be a source of annoyance for some people. The difference between both types is the reason for annoyance. While it is acknowledged that noise from wind turbines can be annoying to some and associated with some reported health effects (e.g., sleep disturbance), especially when found at sound pressure levels greater than 40 db(A), given that annoyance appears to be more strongly related to visual cues and attitude than to noise itself, self reported health effects of people living near wind turbines are more likely attributed to physical manifestation from an annoyed state than from wind turbines themselves. In other words, it appears that it is the change in the environment that is associated with reported health effects and not a turbine-specific variable like audible noise or infrasound. Regardless of its cause, a certain level of annoyance in a population can be expected (as with any number of projects that change the local environment) and the acceptable level is a policy decision to be made by elected officials and their government representatives where the benefits of wind power are weighted against their cons. Assessing the effects of wind turbines on human health is an emerging field and conducting further research into the effects of wind turbines (and environmental changes) on human health, emotional and physical, is warranted.</p
Safety and effectiveness of a new toric presbyopia-correcting posterior chamber silicone intraocular lens.
PURPOSE: To evaluate the safety and effectiveness of the Trulign toric intraocular lens (IOL) in adults with cataract. SETTING: Eight private practices in the United States and 1 in Canada. DESIGN: Prospective randomized single-masked multicenter study. METHODS: A toric IOL (1.25 D, 2.00 D, or 2.75 D, determined by a toric calculator) was implanted in eligible patients with age-related cataract requiring a 16.00 to 27.00 diopter (D) spherical IOL power and with a predicted postoperative astigmatism of 0.83 to 2.50 D. Eyes within the lowest cylinder range (predicted postoperative astigmatism 0.83 to 1.32 D) were randomized in a 1:1 ratio between the 1.25 D toric IOL group and the nontoric accommodating IOL (Crystalens) control group. RESULTS: The toric 1.25 D group had a statistically significantly greater percentage reduction in absolute cylinder (PÂ <Â .001) and uncorrected distance visual acuity (PÂ =Â .002) than the control group at the 120- to 180-day visit. The mean monocular uncorrected vision at distance, intermediate, and near was 20/25, 20/22, and 20/39, respectively, with the 1.25 D, 2.00 D, and 2.75 D toric IOLs in aggregate (toric group). In addition, 96.1% of patients (123/128) had 5.0 degrees or less absolute IOL rotation postoperatively. Regarding safety, the endpoints for preservation of corrected visual acuity and the incidence of complications and adverse events were met. CONCLUSION: The toric IOL was safe and effective in reducing the effects of preoperative corneal astigmatism and provided excellent uncorrected distance and intermediate vision and functional near vision. FINANCIAL DISCLOSURES: Dr. Pepose is a consultant to Bausch & Lomb and was medical monitor of this study. Drs. Buckhurst, Whitman, Feinerman, Hovanesian, Davies, Labor, and Carter are consultants to Bausch & Lomb. At the time of the study, Drs. Hayashida, and Khodai were employees of Bausch & Lomb. Drs. Colvard and Mittleman have financial or proprietary interest in any material or method mentioned
The influence of climate on early and burial diagenesis of Triassic and Jurassic sandstones from the Norwegian-Danish Basin
Characterization of wooden breast myopathy: a focus on syndecans and ECM remodeling
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