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A demonstration of 'broken' visual space
It has long been assumed that there is a distorted mapping between real and ‘perceived’ space, based on demonstrations of systematic errors in judgements of slant, curvature, direction and separation. Here, we have applied a direct test to the notion of a coherent visual space. In an immersive virtual environment, participants judged the relative distance of two squares displayed in separate intervals. On some trials, the virtual scene expanded by a factor of four between intervals although, in line with recent results, participants did not report any noticeable change in the scene. We found that there was no consistent depth ordering of objects that can explain the distance matches participants made in this environment (e.g. A > B > D yet also A < C < D) and hence no single one-to-one mapping between participants’ perceived space and any real 3D environment. Instead, factors that affect pairwise comparisons of distances dictate participants’ performance. These data contradict, more directly than previous experiments, the idea that the visual system builds and uses a coherent 3D internal representation of a scene
Rural-urban disparities in maternal immunization knowledge and childhood health-seeking behavior in Nigeria: A mixed method study
Background: Immunization and appropriate health-seeking behavior are effective strategies to reduce child deaths.Objectives: To compare maternal knowledge about immunization, use of growth chart and childhood health-seeking behavior in rural and urban areas.Methods: A cross-sectional comparative study done in Lagos, Nigeria. Questionnaire survey and focus group discussions were done. 300 respondents were selected by multi-stage sampling while discussants were purposively selected.Results:Awareness of immunization was high but knowledge of vaccine preventable diseases (VPDs) was poor in both areas. Urban women utilized preventive services more; growth monitoring (p<0.001) and immunization (p<0.001) while higher proportions of rural women utilized nutritional counseling (p=0.005) and treatment of illness (p<0.001). Growth chart utilization was better in the urban areas (p<0.001). Increasing maternal education increased use of growth chart in both areas. Both groups of women use multiple treatment sources for children (more in urban), determined by cost, time, perceived severity of illness and type of ailment (urban) and peculiarity of illness (rural). There is a preference for orthodox care in the rural area.Conclusions:Knowledge of VPDs was poor and multiple treatment sources were common among rural and urban women. Education is vital to improve immunization knowledge and health-seeking behavior in both areas.Key Words: Immunization; growth chart; health-seeking behavior; child health; Nigeri
Domain wall brane in squared curvature gravity
We suggest a thick braneworld model in the squared curvature gravity theory.
Despite the appearance of higher order derivatives, the localization of gravity
and various bulk matter fields is shown to be possible. The existence of the
normalizable gravitational zero mode indicates that our four-dimensional
gravity is reproduced. In order to localize the chiral fermions on the brane,
two types of coupling between the fermions and the brane forming scalar is
introduced. The first coupling leads us to a Schr\"odinger equation with a
volcano potential, and the other a P\"oschl-Teller potential. In both cases,
the zero mode exists only for the left-hand fermions. Several massive KK states
of the fermions can be trapped on the brane, either as resonant states or as
bound states.Comment: 18 pages, 5 figures and 1 table, references added, improved version
to be published in JHE
Evaluation of the current knowledge limitations in breast cancer research: a gap analysis
BACKGROUND
A gap analysis was conducted to determine which areas of breast cancer research, if targeted by researchers and funding bodies, could produce the greatest impact on patients.
METHODS
Fifty-six Breast Cancer Campaign grant holders and prominent UK breast cancer researchers participated in a gap analysis of current breast cancer research. Before, during and following the meeting, groups in seven key research areas participated in cycles of presentation, literature review and discussion. Summary papers were prepared by each group and collated into this position paper highlighting the research gaps, with recommendations for action.
RESULTS
Gaps were identified in all seven themes. General barriers to progress were lack of financial and practical resources, and poor collaboration between disciplines. Critical gaps in each theme included: (1) genetics (knowledge of genetic changes, their effects and interactions); (2) initiation of breast cancer (how developmental signalling pathways cause ductal elongation and branching at the cellular level and influence stem cell dynamics, and how their disruption initiates tumour formation); (3) progression of breast cancer (deciphering the intracellular and extracellular regulators of early progression, tumour growth, angiogenesis and metastasis); (4) therapies and targets (understanding who develops advanced disease); (5) disease markers (incorporating intelligent trial design into all studies to ensure new treatments are tested in patient groups stratified using biomarkers); (6) prevention (strategies to prevent oestrogen-receptor negative tumours and the long-term effects of chemoprevention for oestrogen-receptor positive tumours); (7) psychosocial aspects of cancer (the use of appropriate psychosocial interventions, and the personal impact of all stages of the disease among patients from a range of ethnic and demographic backgrounds).
CONCLUSION
Through recommendations to address these gaps with future research, the long-term benefits to patients will include: better estimation of risk in families with breast cancer and strategies to reduce risk; better prediction of drug response and patient prognosis; improved tailoring of treatments to patient subgroups and development of new therapeutic approaches; earlier initiation of treatment; more effective use of resources for screening populations; and an enhanced experience for people with or at risk of breast cancer and their families. The challenge to funding bodies and researchers in all disciplines is to focus on these gaps and to drive advances in knowledge into improvements in patient care
Planar and van der Waals heterostructures for vertical tunnelling single electron transistors
Despite a rich choice of two-dimensional materials, which exists these days, heterostructures, both vertical (van der Waals) and in-plane, offer an unprecedented control over the properties and functionalities of the resulted structures. Thus, planar heterostructures allow p-n junctions between different two-dimensional semiconductors and graphene nanoribbons with well-defined edges; and vertical heterostructures resulted in the observation of superconductivity in purely carbon-based systems and realisation of vertical tunnelling transistors. Here we demonstrate simultaneous use of in-plane and van der Waals heterostructures to build vertical single electron tunnelling transistors. We grow graphene quantum dots inside the matrix of hexagonal boron nitride, which allows a dramatic reduction of the number of localised states along the perimeter of the quantum dots. The use of hexagonal boron nitride tunnel barriers as contacts to the graphene quantum dots make our transistors reproducible and not dependent on the localised states, opening even larger flexibility when designing future devices
Measurements of the diffuse Galactic synchrotron spectral index and curvature from MeerKLASS pilot data
21cm intensity mapping experiments are bringing an influx of high spectral
resolution observational data in the MHz GHz regime. We use
pilot MHz data from MeerKAT in single-dish mode, recently used to
test the calibration and data reduction scheme of the upcoming MeerKLASS
survey, to probe the spectral index of diffuse synchrotron emission below 1 GHz
within , .
Through comparisons with data from the OVRO Long Wavelength Array and the Maipu
and MU surveys, we find an average spectral index of
between 45 and 1055 MHz. By fitting for spectral curvature with a spectral
index of the form , we measure
and within our target field. Our
results are in good agreement (within ) with existing measurements
from experiments such as ARCADE2 and EDGES. These results show the calibration
accuracy of current data and demonstrate that MeerKLASS will also be capable of
achieving a secondary science goal of probing the interstellar medium.Comment: 17 pages, 13 figures, accepted for publication in MNRAS. Updated to
match published paper (additional references and acknowledgements
Long-term nitrogen addition modifies microbial composition and functions for slow carbon cycling and increased sequestration in tropical forest soil.
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record. Nitrogen (N) deposition is a component of global change that has considerable impact on belowground carbon (C) dynamics. Plant growth stimulation and alterations of fungal community composition and functions are the main mechanisms driving soil C gains following N deposition in N-limited temperate forests. In N-rich tropical forests, however, N deposition generally has minor effects on plant growth; consequently, C storage in soil may strongly depend on the microbial processes that drive litter and soil organic matter decomposition. Here, we investigated how microbial functions in old-growth tropical forest soil responded to 13 years of N addition at four rates: 0 (Control), 50 (Low-N), 100 (Medium-N), and 150 (High-N) kg N ha-1 yr-1 . Soil organic carbon (SOC) content increased under High-N, corresponding to a 33% decrease in CO2 efflux, and reductions in relative abundances of bacteria as well as genes responsible for cellulose and chitin degradation. A 113% increase in N2 O emission was positively correlated with soil acidification and an increase in the relative abundances of denitrification genes (narG and norB). Soil acidification induced by N addition decreased available P concentrations, and was associated with reductions in the relative abundance of phytase. The decreased relative abundance of bacteria and key functional gene groups for C degradation were related to slower SOC decomposition, indicating the key mechanisms driving SOC accumulation in the tropical forest soil subjected to High-N addition. However, changes in microbial functional groups associated with N and P cycling led to coincidentally large increases in N2 O emissions, and exacerbated soil P deficiency. These two factors partially offset the perceived beneficial effects of N addition on SOC storage in tropical forest soils. These findings suggest a potential to incorporate microbial community and functions into Earth system models considering their effects on greenhouse gas emission, biogeochemical processes and biodiversity of tropical ecosystems. This article is protected by copyright. All rights reserved.National Natural Science Foundation of ChinaNational Key R&D Program of ChinaYouth Innovation Research Team Projec
Combined artificial bee colony algorithm and machine learning techniques for prediction of online consumer repurchase intention
A novel paradigm in the service sector i.e. services through the web is a progressive mechanism for rendering offerings over diverse environments. Internet provides huge opportunities for companies to provide personalized online services to their customers. But prompt novel web services introduction may unfavorably affect the quality and user gratification. Subsequently, prediction of the consumer intention is of supreme importance in selecting the web services for an application. The aim of study is to predict online consumer repurchase intention and to achieve this objective a hybrid approach which a combination of machine learning techniques and Artificial Bee Colony (ABC) algorithm has been used. The study is divided into three phases. Initially, shopping mall and consumer characteristic’s for repurchase intention has been identified through extensive literature review. Secondly, ABC has been used to determine the feature selection of consumers’ characteristics and shopping malls’ attributes (with > 0.1 threshold value) for the prediction model. Finally, validation using K-fold cross has been employed to measure the best classification model robustness. The classification models viz., Decision Trees (C5.0), AdaBoost, Random Forest (RF), Support Vector Machine (SVM) and Neural Network (NN), are utilized for prediction of consumer purchase intention. Performance evaluation of identified models on training-testing partitions (70-30%) of the data set, shows that AdaBoost method outperforms other classification models with sensitivity and accuracy of 0.95 and 97.58% respectively, on testing data set. This study is a revolutionary attempt that considers both, shopping mall and consumer characteristics in examine the consumer purchase intention.N/
Effect of cucumber consumption on plasma creatinine, urea, uric acid and glucose level in apparently healthy students of college of health sciences, Nnamdi Azikiwe university, Nnewi campus, Anambra state, Nigeria
This study was designed to investigate the effect of oral intake of cucumber on plasma creatinine (Cr), urea, uric acid (Ua) and blood glucose in young apparently healthy students. A total of 29 subjects (14 males and 15 females) were recruited. Each subject was advised to abstain from cucumber and similar vegetables consumption for two weeks. Thereafter, they received 400 g of whole cucumber for 21days prior to their daily breakfast. 5mls each of baseline (day zero) and post consumption (day 22) samples were collected after overnight fast into fluoride oxalate and lithium heparin containers for glucose and other biochemical parameters respectively. Plasma glucose, urea, creatinine and uric acid were analyzed using standard methods. There was a significant decrease in the mean plasma glucose level in post cucumber consumption when compared to the pre-cucumber consumption (4.280.46 vs 4.680.35; p<0.05). However, plasma levels of urea, uric acid and creatinine did not differ significantly between pre and post–cucumber consumption. This study revealed hypoglycaemic effect of cucumber consumption with no harmful effect on the kidney. Therefore, cucumber consumption could be of importance in prevention and management of diabetes mellitus. . Keywords: Cucumber, urea, glucose, Uric acid, Creatinine
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