494 research outputs found

    Generalisation in environmental sound classification : the ‘making sense of sounds’ data set and challenge

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    Humans are able to identify a large number of environmental sounds and categorise them according to high-level semantic categories, e.g. urban sounds or music. They are also capable of generalising from past experience to new sounds when applying these categories. In this paper we report on the creation of a data set that is structured according to the top-level of a taxonomy derived from human judgements and the design of an associated machine learning challenge, in which strong generalisation abilities are required to be successful. We introduce a baseline classification system, a deep convolutional network, which showed strong performance with an average accuracy on the evaluation data of 80.8%. The result is discussed in the light of two alternative explanations: An unlikely accidental category bias in the sound recordings or a more plausible true acoustic grounding of the high-level categories

    Complete mitochondrial DNA sequences provide new insights into the Polynesian motif and the peopling of Madagascar

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    More than a decade of mitochondrial DNA (mtDNA) studies have given the 'Polynesian motif' renowned status as a marker for tracing the late-Holocene expansion of Austronesian speaking populations. Despite considerable research on the Polynesian motif in Oceania, there has been little equivalent work on the western edge of its expansion - leaving major issues unresolved regarding the motif's evolutionary history. This has also led to considerable uncertainty regarding the settlement of Madagascar. In this study, we assess mtDNA variation in 266 individuals from three Malagasy ethnic groups: the Mikea, Vezo, and Merina. Complete mtDNA genome sequencing reveals a new variant of the Polynesian motif in Madagascar; two coding region mutations define a Malagasy-specific sub-branch. This newly defined 'Malagasy motif' occurs at high frequency in all three ethnic groups (13-50%), and its phylogenetic position, geographic distribution, and estimated age all support a recent origin, but without conclusively identifying a specific source region. Nevertheless, the haplotype's limited diversity, similar to those of other mtDNA haplogroups found in our Malagasy groups, best supports a small number of initial settlers arriving to Madagascar through the same migratory process. Finally, the discovery of this lineage provides a set of new polymorphic positions to help localize the Austronesian ancestors of the Malagasy, as well as uncover the origin and evolution of the Polynesian motif itself

    Patterns in Age-Seroprevalence Consistent with Acquired Immunity against Trypanosoma brucei in Serengeti Lions

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    Trypanosomes cause disease in humans and livestock throughout sub-Saharan Africa. Although various species show evidence of clinical tolerance to trypanosomes, until now there has been no evidence of acquired immunity to natural infections. We discovered a distinct peak and decrease in age prevalence of T. brucei s.l. infection in wild African lions that is consistent with being driven by an exposure-dependent increase in cross-immunity following infections with the more genetically diverse species, T. congolense sensu latu. The causative agent of human sleeping sickness, T. brucei rhodesiense, disappears by 6 years of age apparently in response to cross-immunity from other trypanosomes, including the non-pathogenic subspecies, T. brucei brucei. These findings may suggest novel pathways for vaccinations against trypanosomiasis despite the notoriously complex antigenic surface proteins in these parasites

    Nutrition Strategies for Triathlon

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    Contemporary sports nutrition guidelines recommend that each athlete develop a personalised, periodised and practical approach to eating that allows him or her to train hard, recover and adapt optimally, stay free of illness and injury and compete at their best at peak races. Competitive triathletes undertake a heavy training programme to prepare for three different sports while undertaking races varying in duration from 20 min to 10 h. The everyday diet should be adequate in energy availability, provide CHO in varying amounts and timing around workouts according to the benefits of training with low or high CHO availability and spread high-quality protein over the day to maximise the adaptive response to each session. Race nutrition requires a targeted and well-practised plan that maintains fuel and hydration goals over the duration of the specific event, according to the opportunities provided by the race and other challenges, such as a hot environment. Supplements and sports foods can make a small contribution to a sports nutrition plan, when medical supplements are used under supervision to prevent/treat nutrient deficiencies (e.g. iron or vitamin D) or when sports foods provide a convenient source of nutrients when it is impractical to eat whole foods. Finally, a few evidence-based performance supplements may contribute to optimal race performance when used according to best practice protocols to suit the triathlete’s goals and individual responsiveness

    Patterns in Age-Seroprevalence Consistent with Acquired Immunity against Trypanosoma brucei in Serengeti Lions

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    Trypanosomes cause disease in humans and livestock throughout sub-Saharan Africa. Although various species show evidence of clinical tolerance to trypanosomes, until now there has been no evidence of acquired immunity to natural infections. We discovered a distinct peak and decrease in age prevalence of T. brucei s.l. infection in wild African lions that is consistent with being driven by an exposure-dependent increase in cross-immunity following infections with the more genetically diverse species, T. congolense sensu latu. The causative agent of human sleeping sickness, T. brucei rhodesiense, disappears by 6 years of age apparently in response to cross-immunity from other trypanosomes, including the non-pathogenic subspecies, T. brucei brucei. These findings may suggest novel pathways for vaccinations against trypanosomiasis despite the notoriously complex antigenic surface proteins in these parasites

    Heat shock proteins in stabilization of spontaneously restored sinus rhythm in permanent atrial fibrillation patients after mitral valve surgery

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    A spontaneously restored sinus rhythm in permanent atrial fibrillation patients has been often observed after mitral valve (MV) surgery, but persisting duration in sinus rhythm varies from patient to patient. Heat shock proteins (Hsps) may be involved in pathogenesis of atrial fibrillation. We hypothesized that stabilization of restored sinus rhythm is associated with expression of Hsps in the atria. To test this hypothesis, clinical data, biopsies of right atrial appendage, and blood samples were collected from 135 atrial fibrillation patients who spontaneously restored sinus rhythm after conventional isolated MV replacement. Comparison was made between patients who had recurrence of atrial fibrillation within 7 days (AF) vs. patients with persisted sinus rhythm for more than 7 days (SR). Results showed that SR patients had higher activity of heat shock transcription factor 1 (HSF1) as well as upregulated expressions of heat shock cognate 70, Hsp70, and Hsp27 in the tissues. The activation of HSF1–Hsps pathway was associated with less-aggressive pathogenesis as reflected by lower rates of myolysis, apoptosis, interstitial fibrosis, and inflammation in SR patients. However, Hsp60 was lower in both tissue and plasma in SR patients, and was positively correlated with apoptosis, interstitial fibrosis, and inflammation. These findings suggest that the Hsps play important roles in stabilization of restored sinus rhythm after MV surgery by inhibiting AF-related atrial remodeling and arrhythmogenic substrates in atrial fibrillation patients. Low circulating Hsp60 levels preoperatively might predict a stable spontaneously restored sinus rhythm postoperatively

    Kaposi sarcoma incidence in the Swiss HIV Cohort Study before and after highly active antiretroviral therapy

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    Between 1984 and 2006, 12 959 people with HIV/AIDS (PWHA) in the Swiss HIV Cohort Study contributed a total of 73 412 person-years (py) of follow-up, 35 551 of which derived from PWHA treated with highly active antiretroviral therapy (HAART). Five hundred and ninety-seven incident Kaposi sarcoma (KS) cases were identified of whom 52 were among HAART users. Cox regression was used to estimate hazard ratios (HR) and corresponding 95% confidence intervals (CI). Kaposi sarcoma incidence fell abruptly in 1996–1998 to reach a plateau at 1.4 per 1000 py afterwards. Men having sex with men and birth in Africa or the Middle East were associated with KS in both non-users and users of HAART but the risk pattern by CD4 cell count differed. Only very low CD4 cell count (<50 cells μl−1) at enrolment or at HAART initiation were significantly associated with KS among HAART users. The HR for KS declined steeply in the first months after HAART initiation and continued to be low 7–10 years afterwards (HR, 0.06; 95% CI, 0.02–0.17). Thirty-three out of 52 (63.5%) KS cases among HAART users arose among PWHA who had stopped treatment or used HAART for less than 6 months

    A sociological dilemma: race, segregation, and US sociology

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    US sociology has been historically segregated in that, at least until the 1960s, there were two distinct institutionally organized traditions of sociological thought – one black and one white. For the most part, however, dominant historiographies have been silent on that segregation and, at best, reproduce it when addressing the US sociological tradition. This is evident in the rarity with which scholars such as WEB Du Bois, E Franklin Frazier, Oliver Cromwell Cox, or other ‘African American Pioneers of Sociology’, as Saint-Arnaud calls them, are presented as core sociological voices within histories of the discipline. This article addresses the absence of African American sociologists from the US sociological canon and, further, discusses the implications of this absence for our understanding of core sociological concepts. With regard to the latter, the article focuses in particular on the debates around equality and emancipation and discusses the ways in which our understanding of these concepts could be extended by taking into account the work of African American sociologists and their different interpretations of core themes
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