Exploring degeneracies in modified gravity with weak lensing

By considering linear-order departures from general relativity, we compute a novel expression for the weak lensing convergence power spectrum under alternative theories of gravity. This comprises an integral over a 'kernel' of general relativistic quantities multiplied by a theory-dependent 'source' term. The clear separation between theory-independent and -dependent terms allows for an explicit understanding of each physical effect introduced by altering the theory of gravity. We take advantage of this to explore the degeneracies between gravitational parameters in weak lensing observations.Comment: 17 pages, 7 figures. v2: Minor changes to match version accepted by PR

Effects of explicit subtraction instruction on fifth grade students with learning disabilities

This study involved an investigation of the effects of strategy instruction integrated with the concrete-representational-abstract teaching sequence on students with learning disabilities. A multiple probe design across subjects with one replication was used in this study. Two sets of data were analyzed to determine effectiveness of the independent variable (intervention lessons). The first data set consisted of pre and posttest percentage scores and the second data set consisted of baseline, intervention, and maintenance probe scores that were collected throughout the study per the parameters of a multiple probe design. The probe scores were plotted in line graph format and analyzed using visual analysis related to level, trend, and variability of the data points. A total of six fifth grade students (five males and one female) with learning disabilities participated in this study. The participants ranged in age from 10 years 10 months to 12 years 0 months. Each participant met the State of Nevada Administrative Code eligibility criteria for specific learning disabilities and failed to meet their school district\u27s standards related to subtraction with regrouping. The six participants were divided into two triads. The students\u27 learning disability teacher staggered the introduction of the scripted intervention lessons according to the parameters of a multiple probe design. Each intervention lesson contained pedagogically sound systematic and explicit instruction which included (a) an advance organizer, (b) a describe and model stage of instruction, (c) a guided practice stage of instruction, (d) an independent practice stage of instruction, and (e) a problem solving stage of instruction. Additionally, the lessons followed the concrete-representation-abstract teaching sequence. The principal and student investigator observed 20% of the total lessons to ensure that the learning disability teacher implemented the lessons with fidelity. The percentage of agreement between the two observers was 99% indicating a high level of implementation fidelity. Interscorer reliability was established before analyzing the data sets. The learning disability teacher scored all pre-, post-, and maintenance tests for the participants and the student investigator scored 20% of the pre-, post-, and maintenance tests. Interscorer reliability was determined to be 100%. A comparison of pre- and posttests revealed that participants\u27 performance increased on the posttests. As a group, the participants raised their total number of correct responses from an average of 6 correct answers to 14.3 correct answers out of a total of 20 computation subtraction problems that required regrouping to solve. Participants also achieved an average of 21.6 more correct digits from pretests scores to posttest scores on a fluency measure that contained computation subtraction problems that required regrouping. Participants increased the number of correct responses on average by 4.3 on word problems that required subtraction with regrouping skills to be applied. Participants maintained these new skills over time and indicated high levels of satisfaction with regard to the mathematics intervention program. Finally, implications of the current study and suggestion for future research are discussed. With regard to the ongoing probe data, all six participants demonstrated an increase in level from baseline condition to intervention condition. This increase in level was sustained during the maintenance condition for all six participants. All six participants demonstrated a relatively stable flat trend during the intervention condition. With regard to variability, Participant 1 was the only one who demonstrated little variability during intervention condition. Participants 2,3,4,5, and 6 each demonstrated notable variability during the intervention condition and had to repeat 2 to 6 sessions in which they did not attain mastery criteria on their first try

Editorial: Acesso aberto, repositórios, portais de publicações, preservação e comportamento informacional no contexto acadêmico

É com prazer que lançamos mais uma edição da RDBCI, volume16, número 2, de maio a agosto de 2017, que traz como temática para essa edição o “Acesso aberto, repositórios, portais de publicações, preservação e comportamento informacional no contexto acadêmico”

Editorial

Temos o prazer de lançar neste mês mais um número da RDBCI. Neste número contamos com a temática ‘inovação e conhecimento’, portanto este editorial traz as reflexões abordadas nos trabalhos que compõe o volume 15, número 3 da revista e que correspondem a 10 artigos, 2 artigos de pesquisa e 1 resenha

Editorial: Preservação digital e sua prática nos diversos campos dos saberes

Nesse número, trazemos como temática “Preservação digital e sua prática nos diversos campos dos saberes” com o propósito de enriquecer e contribuir para as iniciativas e práticas sobre a preservação digital brasileira, em grande parte promovida pela Rede Brasileira de Serviços de Preservação Digital – Rede Cariniana..

Caracterização do perfil neuropsicológico, acadêmico e comportamental de crianças e adolescentes sobreviventes de tumores de fossa posterior

Cancer is the leading cause of death among Brazilian children, and 12.600 cases are estimated for 2017. Central nervous system (CNS) tumors are the most common on childhood, from which 60% arise in cerebellum or adjacent structures of posterior fossa. The lesion and treatment affect CNS functioning, and alterations in higher order functions have been related to the interruption of important connections between the cerebellum and cortical areas. Radiotherapy is responsible for increasing survivorship in malignant tumor cases, but it also promotes neurotoxic effects to the developing CNS. This study aimed to investigate neuropsychological and academic functioning in survivors of posterior fossa tumors. The research was subdivided into three studies: 1) Description of intellectual performance of pediatric patients diagnosed with posterior fossa tumors; 2) Investigation of executive functions in pediatric survivors of posterior fossa tumors and; 3) Proposal of a conceptual model to explain the neuropsychological profile of children and adolescents submitted to cranial radiation. 37 subjects aged 6-16 integrated clinical group, and 24 subjects formed a healthy control group matched 1:1 with the participants of studies 2 and 3 according to sex, age, type of school and socioeconomic level. Participants were submitted to neuropsychological evaluation and results were analyzed through descriptive and inferential statistical tools and clinic-qualitative analysis. In the first study, children who underwent radiotherapy had significantly lower performances on intellectual domains compared to children only surgically treated, mainly in nonverbal and processing speed domains. Nonverbal domain revealed significant differences according to treatment modality, while verbal domain led to significant differences according to mother educational level, which reveals a dissociation regarding to the domains more strongly affected by the tumor and the treatment, and the domains more affected by sociocultural factors. Children diagnosed later showed lower performances, which disagree with previous studies. The second study revealed executive impairments on both clinical groups in terms of working memory, inhibition, flexibility and planning. Children submitted to radiotherapy showed a broader range of affected domains and the most serious impairments compared to children who did not undergo radiotherapy. These children showed difficulties only in measures with more sophisticated executive demands, while children submitted to radiotherapy also presented impairments in more simple executive tasks. The third study presented important results towards the comprehension of the neuropsychological profile of children submitted to cranial radiation therapy. Data suggest that demyelination caused by radiotherapy leads to right hemisphere typical impairments, in a pattern which is similar to the Nonverbal Learning Disability (NLD) profile. Theoretical reflections resulting from data interpretation led to the proposition of a conceptual, comprehensive and systemic model as an explanation hypothesis to the emergency of childhood medulloblastoma neuropsychological profile. It is expected that this study encourage research interest towards the understanding of difficulties and challenges faced by this population, in order to contribute to the creation of public policies which enable children’s social and academic reinsertion after treatment, as well as to the creation of intervention programs which ensure the improvement of survivors’ quality of life.O câncer é a primeira causa de morte de crianças no Brasil, com 12.600 casos estimados para 2017. Tumores de sistema nervoso central (SNC) são os mais comuns na infância e 60% atingem cerebelo e adjacências na fossa posterior. A lesão e o tratamento impactam o SNC e alterações em funções complexas vêm sendo associadas à interrupção de conexões entre o cerebelo e áreas corticais. A radioterapia, responsável pelo aumento da sobrevida em casos de tumores malignos, possui ação neurotóxica sobre o SNC em desenvolvimento. O objetivo do presente estudo é investigar o funcionamento neuropsicológico e acadêmico de crianças e adolescentes sobreviventes de tumores de fossa posterior. A pesquisa foi subdividida em três estudos: 1) Caracterização da capacidade intelectual de pacientes pediátricos diagnosticados com tumores de fossa posterior; 2) Investigação das funções executivas em pacientes pediátricos sobreviventes de tumores de fossa posterior e; 3) Proposição de modelo conceitual para explicar o perfil neuropsicológico de crianças e adolescentes submetidas à radiação craniana. 37 sujeitos com idades entre seis e 16 anos compuseram o grupo clínico e 24 sujeitos saudáveis compuseram grupo controle, pareados 1:1 segundo sexo, idade, tipo de escola e nível socioeconômico dos participantes dos estudos 2 e 3. Os participantes passaram por avaliação neuropsicológica, com resultados analisados por ferramentas estatísticas descritivas e inferenciais e análise clínico-qualitativa. No estudo 1, crianças submetidas à radioterapia apresentaram desempenho significativamente inferior ao de crianças submetidas apenas à neurocirurgia em todos os domínios intelectuais, notadamente os não-verbais e velocidade de processamento. O domínio não verbal revelou diferenças significativas em função do tipo de tratamento, enquanto o domínio verbal acarretou diferenças significativas em função da escolaridade materna, revelando dissociação quanto aos domínios cognitivos mais afetados pelo tumor e pelo tratamento, e aqueles mais impactados por fatores socioculturais. Crianças diagnosticadas tardiamente apresentaram pior desempenho, contradizendo estudos anteriores. O estudo 2 revelou alterações executivas nos domínios da memória de trabalho, inibição, flexibilidade e planejamento em ambos os grupos clínicos. Crianças submetidas à radioterapia apresentaram mais domínios afetados e prejuízos mais severos. Crianças tratadas apenas com neurocirurgia apresentaram dificuldades restritas a tarefas com demandas executivas mais sofisticadas, enquanto crianças submetidas à radioterapia apresentaram dificuldades nestes e em tarefas mais simples. O estudo 3 apresentou importantes resultados em direção à compreensão do perfil neuropsicológico de crianças submetidas à radioterapia. Os dados sugerem que a desmielinização provocada pela radioterapia acarreta alterações típicas de lesões do hemisfério direito, em padrão semelhante ao perfil do Transtorno Não-Verbal de Aprendizagem (TNVA). As reflexões teóricas resultantes da interpretação dos dados levaram à proposição de modelo conceitual, compreensivo e sistêmico como hipótese explicativa para a emergência do perfil neuropsicológico apresentado por sobreviventes de meduloblastoma. Espera-se que o estudo estimule o interesse pelo aprofundamento da compreensão acerca das dificuldades e desafios enfrentados por essa população, visando contribuir para a proposição de políticas públicas que promovam a reinserção social e acadêmica das crianças após o tratamento, bem como para a criação de programas de intervenção que garantam a melhoria da qualidade de vida dos sobreviventes

Label-free segmentation from cardiac ultrasound using self-supervised learning

Segmentation and measurement of cardiac chambers is critical in cardiac ultrasound but is laborious and poorly reproducible. Neural networks can assist, but supervised approaches require the same laborious manual annotations. We built a pipeline for self-supervised (no manual labels) segmentation combining computer vision, clinical domain knowledge, and deep learning. We trained on 450 echocardiograms (93,000 images) and tested on 8,393 echocardiograms (4,476,266 images; mean 61 years, 51% female), using the resulting segmentations to calculate biometrics. We also tested against external images from an additional 10,030 patients with available manual tracings of the left ventricle. r2 between clinically measured and pipeline-predicted measurements were similar to reported inter-clinician variation and comparable to supervised learning across several different measurements (r2 0.56-0.84). Average accuracy for detecting abnormal chamber size and function was 0.85 (range 0.71-0.97) compared to clinical measurements. A subset of test echocardiograms (n=553) had corresponding cardiac MRIs, where MRI is the gold standard. Correlation between pipeline and MRI measurements was similar to that between clinical echocardiogram and MRI. Finally, the pipeline accurately segments the left ventricle with an average Dice score of 0.89 (95% CI [0.89]) in the external, manually labeled dataset. Our results demonstrate a manual-label free, clinically valid, and highly scalable method for segmentation from ultrasound, a noisy but globally important imaging modality.Comment: 37 pages, 3 Tables, 7 Figure

Qualidade de vida no trabalho: estudo de caso em uma empresa público-privada do setor elétrico com sede no Distrito Federal

A elaboração da pesquisa teve como método um estudo de caso com caráter exploratório, dando ênfase aos fatores de qualidade de vida no trabalho. Realizado na presidência de uma empresa público-privada do setor elétrico, responsável pela geração e distribuição de energia, o estudo teve como objetivo verificar se os fatores de QVT, baseados no modelo de Walton, são considerados relevantes da mesma maneira entre os gerentes e demais empregados da presidência de tal organização, que tem sede no Distrito Federal. Diante de uma abordagem quantitativa, buscou-se a verificação dos resultados da análise de dados que foram coletados com a aplicação de um questionário baseado no modelo de Walton (1973) que evidencia os fatores relacionados com os seguintes aspectos: qualidade de vida global da empresa, condições ambientais, saúde, moral, compensação, participação, comunicação, imagem da empresa, relação chefe-subordinado e a organização do trabalho como relevantes para a identificação da qualidade no ambiente profissional. O questionário foi aplicado para 9 gerentes e 41 empregados sem função gerencial, o que corresponde um total de 40% dos empregados da presidência da empresa. Os resultados obtidos com a aplicação do questionário possibilitaram descrever e analisar as percepções, sob os diferentes pontos de vista gerencial e funcional, da relevância dos fatores de qualidade de vida no trabalho. Evidenciou-se que os empregados que possuem distintos níveis hierárquicos percebem a relevância dos fatores de QVT de maneira diversa