148 research outputs found
The Speed of Smell: Odor-Object Segregation within Milliseconds
Segregating objects from background, and determining which of many concurrent stimuli belong to the same object, remains one of the most challenging unsolved problems both in neuroscience and in technical applications. While this phenomenon has been investigated in depth in vision and audition it has hardly been investigated in olfaction. We found that for honeybees a 6-ms temporal difference in stimulus coherence is sufficient for odor-object segregation, showing that the temporal resolution of the olfactory system is much faster than previously thought
The Danger of Having All Your Eggs in One Basket—Winter Crash of the Re-Introduced Przewalski's Horses in the Mongolian Gobi
Large mammals re-introduced into harsh and unpredictable environments are vulnerable to stochastic effects, particularly in times of global climate change. The Mongolian Gobi is home to several rare large ungulates such as re-introduced Przewalski's horses (Equus ferus przewalskii) and Asiatic wild asses (Equus hemionus), but also to a millennium-old semi-nomadic livestock herding culture
Biodiversity of the Deep-Sea Continental Margin Bordering the Gulf of Maine (NW Atlantic): Relationships among Sub-Regions and to Shelf Systems
Background: In contrast to the well-studied continental shelf region of the Gulf of Maine, fundamental questions regarding
the diversity, distribution, and abundance of species living in deep-sea habitats along the adjacent continental margin
remain unanswered. Lack of such knowledge precludes a greater understanding of the Gulf of Maine ecosystem and limits
development of alternatives for conservation and management.
Methodology/Principal Findings: We use data from the published literature, unpublished studies, museum records and
online sources, to: (1) assess the current state of knowledge of species diversity in the deep-sea habitats adjacent to the Gulf
of Maine (39–43uN, 63–71uW, 150–3000 m depth); (2) compare patterns of taxonomic diversity and distribution of
megafaunal and macrofaunal species among six distinct sub-regions and to the continental shelf; and (3) estimate the
amount of unknown diversity in the region. Known diversity for the deep-sea region is 1,671 species; most are narrowly
distributed and known to occur within only one sub-region. The number of species varies by sub-region and is directly
related to sampling effort occurring within each. Fishes, corals, decapod crustaceans, molluscs, and echinoderms are
relatively well known, while most other taxonomic groups are poorly known. Taxonomic diversity decreases with increasing
distance from the continental shelf and with changes in benthic topography. Low similarity in faunal composition suggests
the deep-sea region harbours faunal communities distinct from those of the continental shelf. Non-parametric estimators of
species richness suggest a minimum of 50% of the deep-sea species inventory remains to be discovered.
Conclusions/Significance: The current state of knowledge of biodiversity in this deep-sea region is rudimentary. Our ability
to answer questions is hampered by a lack of sufficient data for many taxonomic groups, which is constrained by sampling
biases, life-history characteristics of target species, and the lack of trained taxonomists
The genetic epidemiology of joint shape and the development of osteoarthritis
Congruent, low-friction relative movement between the articulating elements of a synovial joint is an essential pre-requisite for sustained, efficient, function. Where disorders of joint formation or maintenance exist, mechanical overloading and osteoarthritis (OA) follow. The heritable component of OA accounts for ~ 50% of susceptible risk. Although almost 100 genetic risk loci for OA have now been identified, and the epidemiological relationship between joint development, joint shape and osteoarthritis is well established, we still have only a limited understanding of the contribution that genetic variation makes to joint shape and how this modulates OA risk. In this article, a brief overview of synovial joint development and its genetic regulation is followed by a review of current knowledge on the genetic epidemiology of established joint shape disorders and common shape variation. A summary of current genetic epidemiology of OA is also given, together with current evidence on the genetic overlap between shape variation and OA. Finally, the established genetic risk loci for both joint shape and osteoarthritis are discussed
Treatment of forefoot problems in older people: study protocol for a randomised clinical trial comparing podiatric treatment to standardised shoe advice
<p>Abstract</p> <p>Background</p> <p>Foot problems in general and forefoot problems in particular can lead to a decrease in mobility and a higher risk of falling. Forefoot problems increase with age and are more common in women than in men. Around 20% of people over 65 suffer from non-traumatic foot problems and 60% of these problems are localised in the forefoot. Little is known about the best way to treat forefoot problems in older people. The aim of this study is to compare the effects of two common modes of treatment in the Netherlands: shoe advice and podiatric treatment. This paper describes the design of this study.</p> <p>Methods</p> <p>The study is designed as a pragmatic randomised clinical trial (RCT) with 2 parallel intervention groups. People aged 50 years and over who have visited their general practitioner (GP) with non traumatic pain in the forefoot in the preceding year and those who will visit their GP during the recruitment period with a similar complaint will be recruited for this study. Participants must be able to walk unaided for 7 metres and be able to fill in questionnaires. Exclusion criteria are: rheumatoid arthritis, neuropathy of the foot or pain caused by skin problems (e.g. warts, eczema). Inclusion and exclusion criteria will be assessed by a screening questionnaire and baseline assessment. Those consenting to participation will be randomly assigned to either a group receiving a standardised shoe advice leaflet (n = 100) or a group receiving podiatric treatment (n = 100). Primary outcomes will be the severity of forefoot pain (0-10 on a numerical rating scale) and foot function (Foot Function 5-pts Index and Manchester Foot Pain and Disability Index). Treatment adherence, social participation and quality of life will be the secondary outcomes. All outcomes will be obtained through self-administered questionnaires at the start of the study and after 3, 6, 9 and 12 months. Data will be analysed according to the "intention-to-treat" principle using multilevel level analysis.</p> <p>Discussion</p> <p>Strength of this study is the comparison between two common primary care treatments for forefoot problems, ensuring a high external validity of this trial.</p> <p>Trial registration</p> <p>Netherlands Trial Register (NTR): <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2212">NTR2212</a></p
- …