Shaping electron wave functions in a carbon nanotube with a parallel magnetic field

A magnetic field, through its vector potential, usually causes measurable changes in the electron wave function only in the direction transverse to the field. Here we demonstrate experimentally and theoretically that in carbon nanotube quantum dots, combining cylindrical topology and bipartite hexagonal lattice, a magnetic field along the nanotube axis impacts also the longitudinal profile of the electronic states. With the high (up to 17T) magnetic fields in our experiment the wave functions can be tuned all the way from "half-wave resonator" shape, with nodes at both ends, to "quarter-wave resonator" shape, with an antinode at one end. This in turn causes a distinct dependence of the conductance on the magnetic field. Our results demonstrate a new strategy for the control of wave functions using magnetic fields in quantum systems with nontrivial lattice and topology.Comment: 5 figure

Persistent poverty and children's cognitive development: evidence from the UK Millennium Cohort Study

We use data from the four sweeps of the UK Millennium Cohort Study of children born at the turn of the 21st century to document the effect that poverty, and in particular persistent poverty, has on their cognitive development in their early years. Using structural equation modelling, we show that children born into poverty have significantly lower test scores at age 3, age 5 and age 7 years, and that continually living in poverty in their early years has a cumulative negative effect on their cognitive development. For children who are persistently in poverty throughout their early years, their cognitive development test scores at age 7 years are almost 20 percentile ranks lower than children who have never experienced poverty, even after controlling for a wide range of background characteristics and parental investment

What are communities of practice? A comparative review of four seminal works

This paper is a comparative review of four seminal works on communities of practice. It is argued that the ambiguities of the terms community and practice are a source of the concept's reusability allowing it to be reappropriated for different purposes, academic and practical. However, it is potentially confusing that the works differ so markedly in their conceptualizations of community, learning, power and change, diversity and informality. The three earlier works are underpinned by a common epistemological view, but Lave and Wenger's 1991 short monograph is often read as primarily about the socialization of newcomers into knowledge by a form of apprenticeship, while the focus in Brown and Duguid's article of the same year is, in contrast, on improvising new knowledge in an interstitial group that forms in resistance to management. Wenger's 1998 book treats communities of practice as the informal relations and understandings that develop in mutual engagement on an appropriated joint enterprise, but his focus is the impact on individual identity. The applicability of the concept to the heavily individualized and tightly managed work of the twenty-first century is questionable. The most recent work by Wenger – this time with McDermott and Snyder as coauthors – marks a distinct shift towards a managerialist stance. The proposition that managers should foster informal horizontal groups across organizational boundaries is in fact a fundamental redefinition of the concept. However it does identify a plausible, if limited, knowledge management (KM) tool. This paper discusses different interpretations of the idea of 'co-ordinating' communities of practice as a management ideology of empowerment

Phenotype-based variation as a biomarker of sensitivity to molecularly targeted therapy in melanoma

Transcriptomic phenotypes defined for melanoma have been reported to correlate with sensitivity to various drugs. In this study, we aimed to define a minimal signature that could be used to distinguish melanoma sub-types in vitro, and to determine suitable drugs by which these sub-types can be targeted. By using primary melanoma cell lines, as well as commercially available melanoma cell lines, we find that the evaluation of MLANA and INHBA expression is as capable as one based on a combined analysis performed with genes for stemness, EMT and invasion/proliferation, in identifying melanoma subtypes that differ in their sensitivity to molecularly targeted drugs. Using this approach, we find that 75% of melanoma cell lines can be treated with either the MEK inhibitor AZD6244 or the HSP90 inhibitor 17AAG. © The Royal Society of Chemistry

Research on the Geography of Agricultural Change: Redundant or Revitalized?

Future research directions for agricultural geography were the subject of debate in Area in the late 1980s. The subsequent application of political economy ideas undoubtedly revived interest in agricultural research. This paper argues that agricultural geography contains greater diversity than the dominant political economy discourse would suggest. It reviews ‘other’ areas of agricultural research on policy, post-productivism, people, culture and animals, presenting future suggestions for research. They should ensure that agricultural research continues revitalized rather than redundant into the next millennium

Knowledge and practices regarding child development among primary healthcare professionals

OBJECTIVE: To evaluate the knowledge and practices regarding child development among physicians working in primary healthcare units. METHOD: Cross-sectional descriptive study carried out at primary healthcare units in Embu, São Paulo, Brazil. Study procedures: 1) Evaluation of knowledge: test consisting of 20 multiple-choice questions on child development applied to all 31 physicians who were providing pediatric care at the primary healthcare units; 2) Evaluation of practices: semi-structured interview applied to a sample of 154 mothers/caregivers of children aged up to 36 months during follow-up visits at primary healthcare units in the municipality. For the comparisons of categorical variables (evaluation/advices about development in visits of children at different ages), the chi-square test was employed. RESULTS: The mean number of correct responses among physicians was 14.8. The error rate for seven questions was greater than 30% (sensory development, language acquisition, physiology of the nervous system, clinical and laboratory diagnosis of congenital infections and innate errors of metabolism) and the rate of correct responses was greater than 85% for four questions (motor and personal-social development markers, risk factors and genetic syndromes). Regarding practices, in 69 (45%) visits, the doctor asked the mother/caregiver's opinion about the child's development; in 80 (52%), the mother/caregiver said that the doctor assessed the development; and in 64 (42%), the mother/caregiver said that the doctor advised them on practices for child's stimulation. CONCLUSIONS: Faulty knowledge and practices regarding child development were identified among primary care professionals, indicating the need for continued education.OBJETIVO: Avaliar o conhecimento e as práticas sobre desenvolvimento infantil de médicos que atuam em Unidades Básicas de Saúde (UBS). MÉTODO: Estudo transversal, descritivo, realizado nas UBS de Embu (SP). Procedimentos do estudo: 1) avaliação do conhecimento por teste contendo 20 questões de múltipla escolha sobre desenvolvimento da criança aplicado a 31 médicos (universo) que prestam assistência pediátrica em UBS; 2) avaliação das práticas - entrevista semiestruturada aplicada para uma amostra de 154 mães/cuidadores que acompanhavam crianças com idade menor ou igual a 36 meses em consulta médica agendada em UBS do município. Para comparação de variáveis categóricas (avaliação/orientações sobre desenvolvimento em consultas de crianças de diferentes faixas etárias), utizou-se o qui-quadrado. RESULTADOS: A média de acertos dos médicos foi de 14,8 questões; sete questões apresentaram índices de erros superiores a 30% (desenvolvimento sensorial, aquisição de linguagem, fisiologia do sistema nervoso, diagnóstico clínico e laboratorial de infecções congênitas, erros inatos do metabolismo) e quatro questões apresentaram acertos acima de 85% (marcos do desenvolvimento motor, pessoal-social, fatores de risco e síndrome genética). Quanto às práticas, em 69 (45%) consultas o médico perguntou a opinião da mãe/cuidador sobre o desenvolvimento da criança, em 80 (52%) a mãe/cuidador referiu que o médico fez alguma pergunta e/ou avaliou o desenvolvimento e em 64 (42%) orientou sobre como estimular a criança. CONCLUSÕES: Identificaram-se falhas de conhecimento e nas práticas dos profissionais referentes ao desenvolvimento da criança, o que indica a necessidade de implementar educação permanente.UNIFESP Curso de MedicinaUNIFESP Projeto DesenvolverSecretaria Municipal de Saúde do EmbuUNIFESP Departamento de Pediatria Disciplina de Pediatria Geral e ComunitáriaUNIFESP, Curso de MedicinaUNIFESP, Projeto DesenvolverUNIFESP, Depto. de Pediatria Disciplina de Pediatria Geral e ComunitáriaSciEL

Short- and long-lasting tinnitus relief induced by transcranial direct current stimulation

A significant proportion of the population suffers from tinnitus, a bothersome auditory phantom perception that can severely alter the quality of life. Numerous experimental studies suggests that a maladaptive plasticity of the auditory and limbic cortical areas may underlie tinnitus. Accordingly, repetitive transcranial magnetic stimulation (rTMS) has been repeatedly used with success to reduce tinnitus intensity. The potential of transcranial direct current stimulation (tDCS), another promising method of noninvasive brain stimulation, to relieve tinnitus has not been explored systematically. In a double-blind, placebo-controlled and balanced order design, 20 patients suffering from chronic untreatable tinnitus were submitted to 20 minutes of 1 mA anodal, cathodal and sham tDCS targeting the left temporoparietal area. The primary outcome measure was a change in tinnitus intensity or discomfort assessed with a Visual Analogic Scale (VAS) change-scale immediately after tDCS and 1 hour later. Compared to sham tDCS, anodal tDCS significantly reduced tinnitus intensity immediately after stimulation; whereas cathodal tDCS failed to do so. The variances of the tinnitus intensity and discomfort VAS change-scales increased dramatically after anodal and cathodal tDCS, whereas they remained virtually unchanged after sham tDCS. Moreover, several patients unexpectedly reported longer-lasting effects (at least several days) such as tinnitus improvement, worsening, or changes in tinnitus features, more frequently after real than sham tDCS. Anodal tDCS is a promising therapeutic tool for modulating tinnitus perception. Moreover, both anodal and cathodal tDCS seem able to alter tinnitus perception and could, thus, be used to trigger plastic changes

Adjuvant Autologous Melanoma Vaccine for Macroscopic Stage III Disease: Survival, Biomarkers, and Improved Response to CTLA-4 Blockade

Background. There is not yet an agreed adjuvant treatment for melanoma patients with American Joint Committee on Cancer stages III B and C. We report administration of an autologous melanoma vaccine to prevent disease recurrence. Patients and Methods. 126 patients received eight doses of irradiated autologous melanoma cells conjugated to dinitrophenyl and mixed with BCG. Delayed type hypersensitivity (DTH) response to unmodified melanoma cells was determined on the vaccine days 5 and 8. Gene expression analysis was performed on 35 tumors from patients with good or poor survival. Results. Median overall survival was 88 months with a 5-year survival of 54%. Patients attaining a strong DTH response had a significantly better (p = 0.0001) 5-year overall survival of 75% compared with 44% in patients without a strong response. Gene expression array linked a 50-gene signature to prognosis, including a cluster of four cancer testis antigens: CTAG2 (NY-ESO-2), MAGEA1, SSX1, and SSX4. Thirty-five patients, who received an autologous vaccine, followed by ipilimumab for progressive disease, had a significantly improved 3-year survival of 46% compared with 19% in nonvaccinated patients treated with ipilimumab alone (p = 0.007). Conclusion. Improved survival in patients attaining a strong DTH and increased response rate with subsequent ipilimumab suggests that the autologous vaccine confers protective immunity. � 2016 Michal Lotem et al

Traits Contributing to the Autistic Spectrum

It is increasingly recognised that traits associated with autism reflect a spectrum with no clear boundary between typical and atypical behaviour. Dimensional traits are needed to investigate the broader autism phenotype.Ninety-three individual measures reflecting components of social, communication and repetitive behaviours characterising autistic spectrum disorder (ASD) were identified between the ages of 6 months and 9 years from the ALSPAC database. Using missing value imputation, data for 13,138 children were analysed. Factor analysis suggested the existence of 7 factors explaining 85% of the variance. The factors were labelled: verbal ability, language acquisition, social understanding, semantic-pragmatic skills, repetitive-stereotyped behaviour, articulation and social inhibition. Four factors (1, 3, 5 and 7) were specific to ASD being more strongly associated with this phenotype than other co-morbid conditions while other factors were more associated with learning difficulties and specific language impairment. Nevertheless, all 7 factors contributed independently to the explanation of ASD (p<0.001). Exploration of putative genetic causal factors such as variants in the CNTNAP2 gene showed a varying pattern of associations with these traits. An alternative predictive model of ASD was derived using four individual measures: the coherence subscale of the Children's Communication Checklist (9y), the Social and Communication Disorders Checklist (91 m), repetitive behaviour (69 m) and the sociability subscale of the Emotionality Activity and Sociability measure (38 m). Although univarably these traits performed better than some factors, their combined explanations of ASD were similar (R(2) =  0.48).These results support the fractional nature of ASD with different aetiological origins for these components despite pleiotropic genetic effects being observed. These traits are likely to be useful in the exploration of ASD

Fractional anisotropy in white matter tracts of very-low-birth-weight infants

Background: Advances in neonatal intensive care have not yet reduced the high incidence of neurodevelopmental disability among very-low-birth-weight (VLBW) infants. As neurological deficits are related to white-matter injury, early detection is important. Diffusion tensor imaging (DTI) could be an excellent tool for assessment of white-matter injury. Objective: To provide DTI fractional anisotropy (FA) reference values for white-matter tracts of VLBW infants for clinical use. Materials and methods: We retrospectively analysed DTI images of 28 VLBW infants (26-32 weeks gestational age) without evidence of white-matter abnormalities on conventional MRI sequences, and normal developmental outcome (assessed at age 1-3 years). For DTI an echoplanar sequence with diffusion gradient (b = 1,000 s/mm2) applied in 25 non-collinear directions was used. We measured FA and apparent diffusion coefficient (ADC) of different white-matter tracts in the first 4 days of life. Results: A statistically significant correlation was found between gestational age and FA of the posterior limb of the internal capsule in VLBW infants (r = 0.495, P<0.01). Conclusion: Values of FA and ADC were measured in white-matter tracts of VLBW infants. FA of the pyramidal tracts measured in the first few days after birth is related to gestational age