34 research outputs found

    Relationship between conservation biology and ecology shown through machine reading of 32,000 articles

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    Conservation biology was founded on the idea that efforts to save nature depend on a scientific understanding of how it works. It sought to apply ecological principles to conservation problems. We investigated whether the relationship between these fields has changed over time through machine reading the full texts of 32,000 research articles published in 16 ecology and conservation biology journals. We examined changes in research topics in both fields and how the fields have evolved from 2000 to 2014. As conservation biology matured, its focus shifted from ecology to social and political aspects of conservation. The 2 fields diverged and now occupy distinct niches in modern science. We hypothesize this pattern resulted from increasing recognition that social, economic, and political factors are critical for successful conservation and possibly from rising skepticism about the relevance of contemporary ecological theory to practical conservation

    Tissue engineering of functional articular cartilage: the current status

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    Osteoarthritis is a degenerative joint disease characterized by pain and disability. It involves all ages and 70% of people aged >65 have some degree of osteoarthritis. Natural cartilage repair is limited because chondrocyte density and metabolism are low and cartilage has no blood supply. The results of joint-preserving treatment protocols such as debridement, mosaicplasty, perichondrium transplantation and autologous chondrocyte implantation vary largely and the average long-term result is unsatisfactory. One reason for limited clinical success is that most treatments require new cartilage to be formed at the site of a defect. However, the mechanical conditions at such sites are unfavorable for repair of the original damaged cartilage. Therefore, it is unlikely that healthy cartilage would form at these locations. The most promising method to circumvent this problem is to engineer mechanically stable cartilage ex vivo and to implant that into the damaged tissue area. This review outlines the issues related to the composition and functionality of tissue-engineered cartilage. In particular, the focus will be on the parameters cell source, signaling molecules, scaffolds and mechanical stimulation. In addition, the current status of tissue engineering of cartilage will be discussed, with the focus on extracellular matrix content, structure and its functionality

    Historical Archaeologies of the American West

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    Multiple-probe thermography for estimating the postmortem interval: II. Practical versions of the triple-exponential formulae (TEF) for estimating the time of death in the field

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    A simple, reliable, and relatively accurate method for estimating the time since death is described. It is based on the Triple-Exponential Formulae (TEF), which are devised for the first time in this study. The postmortem cooling rate of the brain, liver, and rectum in 117 forensic cases were investigated (Part I). The method can be used in the field as a computer program, reference graph, or reference chart-ruler. The program is simple and can easily be run by any user. There are six reference graphs representing the average brain, liver, and rectal cooling curves for naked and covered body groups. The ruler is designed for the rectal cooling curves for covered and naked bodies. This method requires one temperature measurement of the chosen body site and the environment. The postmortem interval is estimated as a probable value ± a possible range of time estimates with a built-in confidence limit

    Specific language impairment: linguistic and neurobiological aspects Distúrbio específico de linguagem: aspectos linguísticos e neurobiológicos

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    Specific language impairment (SLI) occurs when children present language maturation, at least 12 months behind their chronological age in the absence of sensory or intellectual deficits, pervasive developmental disorders, evident cerebral damage, and adequate social and emotional conditions. The aim of this study was to classify a group of children according to the subtypes of SLI and to correlate clinical manifestations with cortical abnormalities. Seventeen children with SLI were evaluated. Language assessment was based on standardized test (Peabody) and a non-standardized protocol, which included phonological, syntactical, semantical, pragmatical and lexical aspects of language. All children, except one, had abnormal MRI. Thirteen children presented perisylvian polymicrogyria. The MRI findings in the remaining three patients were: right frontal polymicrogyria, bilateral fronto-parietal atrophy, and hypogenesis of corpus callosum with Chiari I. The data show that patients with posterior cortical involvement tended to present milder form of SLI (no sign of articulatory or bucofacial praxis disturbance), while diffuse polymicrogyric perisylvian cortex usually was seen in patients who presented severe clinical manifestation, mainly phonological-syntactic deficit. In conclusion, SLI may be associated with perisylvian polymicrogyria and clinical manifestation may vary according to the extent of cortical anomaly.<br>O termo distúrbio específico de linguagem (DEL) é utilizado para crianças que apresentam maturação de linguagem atrasada em pelo menos 12 meses em relação à idade cronológica e que não tenham déficits intelectuais ou sensoriais, distúrbios pervasivos do desenvolvimento, dano cerebral evidente, além de terem condições sociais e emocionais adequadas. O objetivo deste estudo foi classificar um grupo de crianças de acordo com os subtipos de DEL e correlacionar as manifestações clínicas com possíveis anormalidades corticais. Dezessete crianças com DEL foram avaliadas. A avaliação de linguagem foi baseada em teste padronizado (Peabody) e protocolo não-padronizado que incluiu os seguintes aspectos da linguagem: fonológicos, semânticos, pragmáticos e lexicais. Todas as crianças, exceto uma, tiveram RM anormal; treze delas com polimicrogiria peri-silviana. Os achados de imagem nos outros três pacientes foram: polimicrogiria frontal direita, atrofia fronto-parietal bilateral, e hipogenesia do corpo caloso com Chiari I. Os dados mostram que pacientes com comprometimento cortical posterior tenderam a apresentar formas mais leves de DEL (sem sinais de distúrbio práxico articulatório ou bucofacial), enquanto pacientes com polimicrogiria peri-silviana difusa apresentaram manifestação clínica mais grave, principalmente déficit fonológico-sintático. Concluindo, DEL pode se associar a polimicrogiria peri-silviana e as manifestações clínicas podem variar de acordo com a extensão da anormalidade cortical
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