Spin phase diagram of the nu_e=4/11 composite fermion liquid

Spin polarization of the "second generation" nu_e=4/11 fractional quantum Hall state (corresponding to an incompressible liquid in a one-third-filled composite fermion Landau level) is studied by exact diagonalization. Spin phase diagram is determined for GaAs structures of different width and electron concentration. Transition between the polarized and partially unpolarized states with distinct composite fermion correlations is predicted for realistic parameters.Comment: 5 pages, 3 figure

The neural correlates of orienting to walking direction in 6-month-old infants: an ERP study

The ability to detect social signals represents a first step to enter our social world. Behavioral evidence has demonstrated that 6‐month‐old infants are able to orient their attention toward the position indicated by walking direction, showing faster orienting responses toward stimuli cued by the direction of motion than toward uncued stimuli. The present study investigated the neural mechanisms underpinning this attentional priming effect by using a spatial cueing paradigm and recording EEG (Geodesic System 128 channels) from 6‐month‐old infants. Infants were presented with a central point‐light walker followed by a single peripheral target. The target appeared randomly at a position either congruent or incongruent with the walking direction of the cue. We examined infants' target‐locked event‐related potential (ERP) responses and we used cortical source analysis to explore which brain regions gave rise to the ERP responses. The P1 component and saccade latencies toward the peripheral target were modulated by the congruency between the walking direction of the cue and the position of the target. Infants' saccade latencies were faster in response to targets appearing at congruent spatial locations. The P1 component was larger in response to congruent than to incongruent targets and a similar congruency effect was found with cortical source analysis in the parahippocampal gyrus and the anterior fusiform gyrus. Overall, these findings suggest that a type of biological motion like the one of a vertebrate walking on the legs can trigger covert orienting of attention in 6‐month‐old infants, enabling enhancement of neural activity related to visual processing of potentially relevant information as well as a facilitation of oculomotor responses to stimuli appearing at the attended location

Individually distinctive features facilitate numerical discrimination of sets of objects in domestic chicks

Day-old domestic chicks approach the larger of two groups of identical objects, but in a 3 vs 4 comparison, their performance is random. Here we investigated whether adding individually distinctive features to each object would facilitate such discrimination. Chicks reared with 7 objects were presented with the operation 1 + 1 + 1 vs 1 + 1 + 1 + 1. When objects were all identical, chicks performed randomly, as expected (Experiment 1). In the remaining experiments, objects differed from one another due to additional features. Chicks succeeded when those features were differently oriented segments (Experiment 2) but failed when the features were arranged to depict individually different face-like displays (Experiment 3). Discrimination was restored if the face-like stimuli were presented upside-down, disrupting global processing (Experiment 4). Our results support the claim that numerical discrimination in 3 vs 4 comparison benefits from the presence of distinctive features that enhance object individuation due to individual processing. Interestingly, when the distinctive features are arranged into upright face-like displays, the process is susceptible to global over local interference due to configural processing. This study was aimed at assessing whether individual object processing affects numerical discrimination. We hypothesise that in humans similar strategies aimed at improving performance at the non-symbolic level may have positive effects on symbolic mathematical abilities

Socio-Economic Factors on Alcohol Abuse among the Youth in Kikuyu District, Kenya

The purpose of this study was to establish Factors Associated with high rate of Alcohol abuse among the youth in Kikuyu District, Kiambu County. It was guided by five research objectives focusing on the influence of peer pressure, parents and guardians, media, role model and social economic on youth engagement in alcohol. It used descriptive survey as well as questionnaire and interview guide as the main tools for data collections. The target population comprised of boys, girls and mixed secondary schools in kikuyu district. However for the purpose of data collection 285 form four students and 104 beer drinkers in pubs were selected. The data was analyzed using the SPSS which yielded frequency tables, percentages and mean. Through the data analysis the study revealed that most of beer customers are single. However, there are some who are married and other divorced.  This is an indication that more youth are engaged in beer taking compared to elderly people. The study also revealed that, majority of the people engaged in beer drinking have secondary education as their highest academic qualification, followed by KCPE holders tying with diploma holders and degree holders respectively. In the same category 60% of the students are engaged in beer taking compared to 40% non students. This was so because of many middle level colleges and the universities in the area. The study also established that 30% of secondary school students are engaged in beer taking. The rest of students involved in beer taking include 40%    tertiary colleges, 20% polytechnic students and 20% university students. Key Words: Alcohol abuse among the youth, Kikuyu District, Keny

Brain deposition of gadobutrol in children—a cross-sectional and longitudinal MRI T1 mapping study

Objectives:Depositions of linear gadolinium-based MRI contrast agents are readily visible in T1-weighted MRIs of certain brain regions in both adults and children. Macrocyclic contrast agents such as gadobutrol have so far escaped detection by qualitative MRI in children. This study aimed to assess whether there is evidence for deposition of gadobutrol in children using quantitative T1 mapping.Methods:This retrospective study included patients, naive to other gadolinium-based contrast agents than gadobutrol, who had received gadobutrol as part of a clinically indicated MRI. For each patient, T1 relaxation times at 3 T were measured using single-shot T1 mapping at two time points. In each of six brain regions, age-adjusted T1 relaxation times were correlated with a number of previous gadobutrol administrations. To combine interindividual, cross-sectional effects with intraindividual, longitudinal effects, both linear mixed model and generalized additive mixed model were applied.Results:One hundred four examinations of 52 children (age median 11.4, IQR 6.3–15, 26 female) with a median of 7 doses of gadobutrol in the history of their neurological or neurooncological disease were included. After correction for age and indeterminate disease-related effects to T1 time, a negative correlation of T1 time with the number of gadobutrol doses administered was observed in both mixed models in the putamen (beta − 1.65, p = .03) and globus pallidus (beta − 1.98, p = .012)Conclusions:The results indicate that in children, gadobutrol is deposited in the globus pallidus and putamen