1,497 research outputs found
How specific is synchronous neuronal firing? : Poster presentation
Background Synchronous neuronal firing has been discussed as a potential neuronal code. For testing first, if synchronous firing exists, second if it is modulated by the behaviour, and third if it is not by chance, a large set of tools has been developed. However, to test whether synchronous neuronal firing is really involved in information processing one needs a direct comparison of the amount of synchronous firing for different factors like experimental or behavioural conditions. To this end we present an extended version of a previously published method NeuroXidence [1], which tests, based on a bi- and multivariate test design, whether the amount of synchronous firing above the chance level is different for different factors
Effects of magnetic field and disorder on electronic properties of Carbon Nanotubes
Electronic properties of metallic and semiconducting carbon nanotubes are
investigated in presence of magnetic field perpendicular to the CN-axis, and
disorder introduced through energy site randomness. The magnetic field field is
shown to induce a metal-insulator transition (MIT) in absence of disorder, and
surprisingly disorder does not affect significantly the MIT. These results may
find confirmation through tunneling experimentsComment: 4 pages, 6 figures. Phys. Rev. B (in press
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Non-stoichiometric oxide and metal interfaces and reactions
We have employed a combination of experimental surface science techniques and density functional calculations to study the reduction of TiO2(110) surfaces through the doping with submonolayer transition metals. We concentrate on the role of Ti adatoms in self doping of rutile and contrast the behaviour to that of Cr. DFT+U calculations enable identification of probable adsorption structures and their spectroscopic characteristics. Adsorption of both metals leads to a broken symmetry and an asymmetric charge transfer localised around the defect site of a mixed localised/delocalised character. Charge transfer creates defect states with Ti 3d character in the band gap at similar to 1-eV binding energy. Cr adsorption, however, leads to a very large shift in the valence-band edge to higher binding energy and the creation of Cr 3d states at 2.8-eV binding energy. Low-temperature oxidation lifts the Ti-derived band-gap states and modifies the intensity of the Cr features, indicative of a change of oxidation state from Cr3+ to Cr4+. Higher temperature processing leads to a loss of Cr from the surface region, indicative of its substitution into the bulk
Outcome comparison between radiation therapy and surgery as primary treatment for dogs with periarticular histiocytic sarcoma: An Italian Society of Veterinary Oncology study
Localized histiocytic sarcoma may occur as a primary lesion in periarticular tissues of large appendicular joints. Treatment options for the primary lesion include radical surgical excision, radiation therapy (RT), or both, in combination with chemotherapy for potential systemic metastases. In an effort to better characterize the time to progression (TTP) following surgical vs non-surgical approaches for periarticular histiocytic sarcoma (PAHS), a contemporary European population of affected dogs was retrospectively surveyed. Medical records were queried for newly-diagnosed PAHS cases undergoing surgery (predominantly limb amputation) or RT followed by systemic chemotherapy. Of 49 dogs, 34 underwent RT and 15 underwent surgery. All dogs received adjuvant chemotherapy. There was no statistically significant difference in TTP or overall survival between groups. The median TTP was 336 days for the operated dogs and 217 days for the irradiated dogs (P =.117). The median overall survival time was 398 days for the operated dogs and 240 days for the irradiated dogs (P =.142). On multi-variable analysis, the variables significantly associated with an increased risk of both tumour progression and tumour-related death were regional lymph node and distant metastasis at admission. Survival and local control rates following RT may be comparable to radical resection. These data may better inform shared decision-making processes between multi-disciplinary care providers and owners
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Evidence for insertional codemixing: mixed compounds and French nominal groups in Brussels Dutch
In this paper we analyse mixed compounds, such as legume+winkel âvegetable shop, greengroceryâ and winter+paletot âwinter coatâ which contain a French and a Dutch element, and French nominal groups, such as carte dâidentitĂ© âidentity cardâ, and journal parlĂ© âradio newsâ, which bilingual speakers from Brussels frequently insert into Brussels Dutch utterances. Using Muyskenâs (2000) typology of bilingual speech, we claim that the mixed compounds and the nominal groups display the characteristics of insertional code-mixing. In addition, some evidence for the existence of a continuum between borrowing and code-switching can be obtained from these examples. As the multimorphemic units that are inserted into Dutch are neither single words, nor full constituents, their status in the lexicon raises interesting issues for researchers interested in the interface between syntax and the lexicon (see also Backus 2003). We try to argue that nominal groups such as carte dâidentitĂ© and journal parlĂ© are probably best seen as lexical templates or constructional idioms (Booij, 2002b). The insertion of French constructional idioms in Brussels Dutch represents an innovation in the lexical patterns that are available to speakers of this language, which is highly relevant for theories of language change
Walkability and self-rated health in primary care patients
BACKGROUND: The objective of this study was to investigate the relationship between perceived walkability and overall self-rated health among patients who use community-based clinics. METHODS: A cross-sectional survey was distributed to a convenience sample in three community clinics. Forms were completed by 793 clinic patients. Multiple logistic regression analysis was to control for the effects of demographic variables and lifestyles. RESULTS: Perceiving the availability of places to walk was related to better self-rated health. The most important places were work (OR = 3.2), community center (OR = 3.12), park (OR = 2.45) and day care (OR = 2.05). Respondents who said they had zero (OR = .27) or one (OR = .49) place to walk were significantly less healthy than persons who said they had five or more places to walk. CONCLUSION: Persons who perceived that they had no place to walk were significantly less healthy than persons who thought they had at least one place to walk (OR = .39). Support for walkable neighborhoods and education of patients about options for walking may be in the best interests of community medicine patients
Stroke genetics: prospects for personalized medicine.
Epidemiologic evidence supports a genetic predisposition to stroke. Recent advances, primarily using the genome-wide association study approach, are transforming what we know about the genetics of multifactorial stroke, and are identifying novel stroke genes. The current findings are consistent with different stroke subtypes having different genetic architecture. These discoveries may identify novel pathways involved in stroke pathogenesis, and suggest new treatment approaches. However, the already identified genetic variants explain only a small proportion of overall stroke risk, and therefore are not currently useful in predicting risk for the individual patient. Such risk prediction may become a reality as identification of a greater number of stroke risk variants that explain the majority of genetic risk proceeds, and perhaps when information on rare variants, identified by whole-genome sequencing, is also incorporated into risk algorithms. Pharmacogenomics may offer the potential for earlier implementation of 'personalized genetic' medicine. Genetic variants affecting clopidogrel and warfarin metabolism may identify non-responders and reduce side-effects, but these approaches have not yet been widely adopted in clinical practice
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