Health and cancer prevention: knowledge and beliefs of children and young people

Objective: To collect information from children and young people about their knowledge of and attitudes towards cancer and their understanding of health and health related behaviours to inform future health promotion work. Design: Questionnaire survey of 15-16 year olds, and interviews with play materials with 9-10 year old children. Setting: Six inner city, suburban, and rural schools. Subjects: 226 children aged 15-16 years and 100 aged 9-10 years. Main outcome measures: Knowledge about different types of cancer; beliefs about health; sources of information; quality of research data obtainable from young children about cancer and health. Results: Both samples knew most about lung cancer, but there was also some knowledge of breast and skin cancer and leukaemia. Smoking, together with pollution and other environmental factors, were seen as the dominant causes of cancer. Environmental factors were mentioned more often by the inner city samples. Television and the media were the most important sources of information. Young people were more worried about unemployment than about ill health. More than half the young people did not describe their health as good, and most said they did not have a healthy lifestyle. Children were able to provide detailed information about their knowledge and understanding by using drawings as well as interviews. Conclusions: Children and young people possess considerable knowledge about cancer, especially about lung cancer and smoking, and show considerable awareness of predominant health education messages. Despite this knowledge, many lead less than healthy lifestyles. Health is not seen as the most important goal in life by many young people; the circumstances in which many children and young people live are not experienced as health promoting

Quantum resolution of black hole singularities

We study the classical and quantum theory of spherically symmetric spacetimes with scalar field coupling in general relativity. We utilise the canonical formalism of geometrodynamics adapted to the Painleve-Gullstrand coordinates, and present a new quantisation of the resulting field theory. We give an explicit construction of operators that capture curvature properties of the spacetime and use these to show that the black hole curvature singularity is avoided in the quantum theory.Comment: 5 pages, version to appear in CQ

Quantum Structure of Space Near a Black Hole Horizon

We describe a midi-superspace quantization scheme for generic single horizon black holes in which only the spatial diffeomorphisms are fixed. The remaining Hamiltonian constraint yields an infinite set of decoupled eigenvalue equations: one at each spatial point. The corresponding operator at each point is the product of the outgoing and ingoing null convergences, and describes the scale invariant quantum mechanics of a particle moving in an attractive $1/X^2$ potential. The variable $X$ that is analoguous to particle position is the square root of the conformal mode of the metric. We quantize the theory via Bohr quantization, which by construction turns the Hamiltonian constraint eigenvalue equation into a finite difference equation. The resulting spectrum gives rise to a discrete spatial topology exterior to the horizon. The spectrum approaches the continuum in the asymptotic region.Comment: References added and typos corrected. 21 pages, 1 figur

Room temperature photonic crystal defect lasers at near-infrared wavelengths in InGaAsP

Room temperature lasing from optically pumped single defects in a two-dimensional (2-D) photonic bandgap (PBG) crystal is demonstrated. The high-Q optical microcavities are formed by etching a triangular array of air holes into a half-wavelength thick multiquantum-well waveguide. Defects in the 2-D photonic crystal are used to support highly localized optical modes with volumes ranging from 2 to 3 (lambda/2n)(3). Lithographic tuning of the air hole radius and the lattice spacing are used to match the cavity wavelength to the quantum-well gain peak, as well as to increase the cavity Q. The defect lasers were pumped with 10-30 ns pulses of 0.4-1% duty cycle. The threshold pump power was 1.5 mW (approximate to 500 μW absorbed)

A Brane Teaser

In this note we study the puzzle posed by two M5-branes intersecting on a string (or equivalently, a single M5-brane wrapping a holomorphic four-cycle in C^4). It has been known for a while that this system is different from all other configurations built using self-intersecting M-branes; in particular the corresponding supergravity solution exhibits various curious features which have remained unexplained. We propose that the resolution to these puzzles lies in the existence of a non-zero two-form on the M5-brane world-volume.Comment: 21 pages. References adde

Basins of attraction of a nonlinear nanomechanical resonator

We present an experiment that systematically probes the basins of attraction of two fixed points of a nonlinear nanomechanical resonator and maps them out with high resolution. We observe a separatrix which progressively alters shape for varying drive strength and changes the relative areas of the two basins of attraction. The observed separatrix is blurred due to ambient fluctuations, including residual noise in the drive system, which cause uncertainty in the preparation of an initial state close to the separatrix. We find a good agreement between the experimentally mapped and theoretically calculated basins of attraction

Magnetotransport properties of lithographically defined lateral Co/Ni80Fe20 wires

In this article we have investigated the magnetization reversal process of laterally defined coupled magnetic structures consisting of micron-sized sputtered Co and Ni80Fe20 wires lying side by side at temperatures ranging from 3 to 300 K. We have used a microfabrication technique to create an array of planar, laterally coupled magnetic wires made of two ferromagnetic materials. We observed two distinct peaks in the magnetoresistance (MR) curves corresponding to the magnetization reversals of Co and Ni80Fe20 wires. Below a critical temperature of 20 K we observed an asymmetric shift in the Ni80Fe20 peak position for both forward and reverse field sweeps due to the exchange coupling between the ferromagnetic (Ni80Fe20) and antiferromagnetic (Co–oxide at the interface of Co and Ni80Fe20 formed during fabrication) parts. The Co peaks gradually disappeared as the temperature was reduced. At low temperature we also observed that the Ni80Fe20 peaks in the MR loops are considerably shifted to larger fields corresponding to the increase in coercivity

Economic optima in soil conservation farming and fertilizer use for farms in the Ida-Monona soil area of western Iowa

Soil erosion is a major agricultural problem in western Iowa. While farmers in the area generally are aware of the erosion problem, relatively few use farm plans which result in the level of conservation needed to stabilize soil loss. Previous studies indicate that economic considerations, particularly, retard adoption of soil-conserving systems of farming. One problem evidently is that insufficient attention has been devoted to determining erosion-control programs for farmers with different amounts of capital, labor and other resources. The purpose of this study is to determine profitable erosion-control systems of farming for operators with different amounts of capital and for two different sizes of farms. Emphasis is on profit maximization for the farm as a whole. Since Ida-Monona soils respond readily to fertilization, the plans considered allow an integration of investment in crops, fertilizer and livestock. Specifically, the study is designed to determine the optimum combination of crop rotations, fertilization levels, erosion-control practices and livestock systems. Conservation systems which primarily control erosion either through land cover or mechanical practices are compared by the linear programming technique

Type of High Secondary School (Governmental Vs Private) and Type of High Secondary School Certificate (Sudanese Vs Arabian): Do They Affect Learning Style?

Background: People differ in the way they perceive, process, store, and recall what they are attempting to learn. This study aimed to assess the learning styles among preclinical 1st year medical students and the influence of the type of high secondary school (governmental vs. private) and type of high secondary school certificate (Sudanese vs. Arabian) on learning style.Materials and Methods: A cross sectional institutional-based study was conducted at Al Neelain University, Khartoum State, Sudan. First year students of Medicine, Dentistry and Physiotherapy Faculties were enrolled. The VARK (Visual, Auditory, Read and write, and Kinesthetic) learning style hard copy questionnaire, © Copyright Version 7.8 (2014) held by VARK Learn Limited, Christchurch, New Zealand was administered following permission. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 21.Results: Out of 320 students, 198 correctly completed VARK questionnaires, with mean age of 17.88 years (SD 1.52) and 74.2% were female students. About 59.6% were from governmental schools and 79.4% of the studied students had Sudanese High Secondary Certificates. About 64.1% demonstrated singular mode preference. Inferential statistics showed statistically significant difference between the learning styles and the type of secondary school whether governmental or private (P-value 0.005) while no statistically significant difference in relation to the type of high school certificate of the studied group (P-value 0.225).Conclusion: The type of secondary school whether governmental or private may affect learning style of medical students while student's gender, type of college, or type of high school certificate (whether Sudanese or Arabian) do not. More andlarger studies are encouraged.Key word: Learning modalities, VARK questionnaire, Unimodal preference, Medicaleducation, Sudan