A Multi-Wavelength Study of the Western Lobe of W50 Powered by the Galactic Microquasar SS 433

W50 remains the only supernova remnant (SNR) confirmed to harbor a microquasar: the powerful enigmatic source SS 433. Our past study of this fascinating SNR revealed two X-ray lobes distorting the radio shell as well as non-thermal X-rays at the site of interaction between the SS 433 eastern jet and the eastern lobe of W50. In this paper we present the results of a 75 ksec CHANDRA ACIS-I observation of the peak of W50-west targeted to 1) determine the nature of the X-ray emission and 2) correlate the X-ray emission with that in the radio and infrared domains. We have confirmed that at the site of interaction between the western jet of SS 433 and dense interstellar gas the X-ray emission is non-thermal in nature. The helical pattern observed in radio is also seen with CHANDRA. No correlation was found between the infrared and X-ray emission.Comment: A refereed publication, submitted Sept. 30, 2004, accepted Jan. 12, 2005, to appear in Advances in Space Research. 7 pages, including 4 figures (3 color) & 1 table (the resolution of most figures has been reduced for astro-ph submission only). A gzipped postscript or pdf version of the paper with high-resolution images can be downloaded from: http://aurora.physics.umanitoba.ca/~moldowan/Astro-Ph

The tunneling conductance between a superconducting STM tip and an out-of-equilibrium carbon nanotube

We calculate the current and differential conductance for the junction between a superconducting (SC) STM tip and a Luttinger liquid (LL). For an infinite single-channel LL, the SC coherence peaks are preserved in the tunneling conductance for interactions weaker than a critical value, while for strong interactions (g <0.38), they disappear and are replaced by cusp-like features. For a finite-size wire in contact with non-interacting leads, we find however that the peaks are restored even for extremely strong interactions. In the presence of a source-drain voltage the peaks/cusps split, and the split is equal to the voltage. At zero temperature, even very strong interactions do not smear the two peaks into a broader one; this implies that the recent experiments of Y.-F. Chen et. al. (Phys. Rev. Lett. 102, 036804 (2009)) do not rule out the existence of strong interactions in carbon nanotubes.Comment: 8 pages, 3 figure

Barriers to Physical Activity: A Comparison of Afghans Living in the UK and Afghanistan

It is important to understand barriers to Physical Activity (PA), particularly for under researched populations. While a lack of PA has been acknowledged as an important issue for those living in Afghanistan, there have been no published studies exploring barriers to PA within this population. Therefore, the purpose of this study was to explore barriers to PA for Afghans and how these differ depending on where they reside: UK or Afghanistan. 930 participants, 578 (291 males; 287 females) were recruited from Afghanistan and 352 (267 males; 85 females) from the UK. A culturally nuanced questionnaire exploring barriers to PA was developed and used to collect data via an online survey software programme. Bayesian ordinal models explored differences between population groups, with results suggesting some barriers are shared across populations but others more pertinent for a particular group. Lack of time and being too tired were barriers for both populations, but were rated higher by those living in Afghanistan; as was a lack of confidence and being uncomfortable with exercise clothing. Afghan females perceived a lack of single-sex facilities, not being able to participate in PA with males, and having to be fully covered outside of the home as important barriers to their PA, but these were more of a barrier for those residing in the UK. The findings highlight important considerations for trying to engage these populations in PA

The Correlation of Built Environment on Hypertension, and Weight Status amongst Adolescence in Saudi Arabia.

The prevalence of hypertension is becoming more common in children and adolescents than ever before. Thus, the aim of this study was to evaluate the associations between the built environment on physical activity, sedentary behaviour, waist circumference, and health amongst adolescents in Saudi Arabia. A systolic and diastolic blood pressure, resting heart rate and waist circumference of 380 boys and girls aged between 15-19 years old (male = 199 and females = 181) were measured. The International physical activity Questionnaire Short Form was used to assess the physical activity levels and time spent sitting. The statistical analysis conducted were means and standard deviation, 2-way and 3-way of variance (ANOVA), Bonferroni post hoc tests, Chi-squared distribution and Pearson's correlations. Among males, 16.75% were classified as hypertensive, 12.69% as pre-hypertensive, and 70.56% as normal whereas, females, 23.20% were classified as hypertensive, 12.15% as pre-hypertensive and 64.64% as normal. There were significant differences (F1,379 = 16.50, p 0.001) between males and females waist circumference. Pearson's correlation also revealed significant positive relationships in sedentary time (r = 0.123, p 0.016), WC (r = 0.104, p 0.043), and systolic blood pressure (r = 0.110, p 0.032). The results revealed that systolic and diastolic blood pressure are significantly related to multiple measures of weight status, and sedentary behaviour. The results also highlight that active youth had lower resting heart rate compared to inactive peers. The present findings provide a foundation of knowledge for future research and highlight the major need for research and policy interventions, to address the concerning health habits of Al-Ahsa youth and broader Kingdom of Saudi Arabia

The Impact of Environment on Physical Activity Levels and Obesity among Saudi Arabia Youth: Comparison of Urban; Rural Farm and Rural Desert Geographical Locations

Background: The inactive lifestyle is becoming prevalent in many developed and developing countries including Saudi Arabia. Thus, the aim of this study was to evaluate the impact of neighborhoods’ characteristics on physical activity (PA) levels and body mass index (BMI) in Saudi adolescents. Methods: The anthropometric measurement of 380 secondary-school (boys = 199; girls = 181) from different geographical locations such as urban, rural farm and rural desert was taken using the Seca digital scales for weight and Seca portable measure for height. The BMI was calculated using the formula kg/m2 followed by participants wearing piezoelectric, New-Lifestyles NL-2000 PA Monitor, and completing the international physical activity short form questionnaire. Results: The findings indicated, an average boys recorded 9180 steps per day compared to girls 5580 and the univariate ANOVA revealed a significant difference between genders steps per day in three geographical areas (F1,334 = 70.01, p < 0.001). The BMI results demonstrated that participant from rural farm had lower BMI (mean = 21.01 kg/m2) compared to urban location (mean = 24.12 kg/m2) and rural desert youth (mean = 25.58 kg/m2) indicating significant differences in BMI status in geographical locations (F2,379 = 16.40, p < 0.001). Conclusion: The inactivity and obesity prevalence are prevalent amongst demographic groups in Al-Ahsa. Therefore, future policies and interventions could target this populations especially the rural desert youth in which the health risk could be higher

The Correlation of Built Environment on Hypertension, and Weight Status amongst Adolescence in Saudi Arabia

The prevalence of hypertension is becoming more common in children and adolescents than ever before. Thus, the aim of this study was to evaluate the associations between the built environment on physical activity, sedentary behaviour, waist circumference, and health amongst adolescents in Saudi Arabia. A systolic and diastolic blood pressure, resting heart rate and waist circumference of 380 boys and girls aged between 15–19 years old (male = 199 and females = 181) were measured. The International physical activity Questionnaire Short Form was used to assess the physical activity levels and time spent sitting. The statistical analysis conducted were means and standard deviation, 2-way and 3-way of variance (ANOVA), Bonferroni post hoc tests, Chi-squared distribution and Pearson’s correlations. Among males, 16.75% were classified as hypertensive, 12.69% as pre-hypertensive, and 70.56% as normal whereas, females, 23.20% were classified as hypertensive, 12.15% as pre-hypertensive and 64.64% as normal. There were significant differences (F1,379 = 16.50, p < 0.001) between males and females waist circumference. Pearson’s correlation also revealed significant positive relationships in sedentary time (r = 0.123, p < 0.016), WC (r = 0.104, p < 0.043), and systolic blood pressure (r = 0.110, p < 0.032). The results revealed that systolic and diastolic blood pressure are significantly related to multiple measures of weight status, and sedentary behaviour. The results also highlight that active youth had lower resting heart rate compared to inactive peers. The present findings provide a foundation of knowledge for future research and highlight the major need for research and policy interventions, to address the concerning health habits of Al-Ahsa youth and broader Kingdom of Saudi Arabia

AC conductance and non-symmetrized noise at finite frequency in quantum wires and carbon nanotubes

We calculate the AC conductance and the finite-frequency non-symmetrized noise in interacting quantum wires and single-wall carbon nanotubes in the presence of an impurity. We observe a strong asymmetry in the frequency spectrum of the non-symmetrized excess noise, even in the presence of the metallic leads. We find that this asymmetry is proportional to the differential excess AC conductance of the system, defined as the difference between the AC differential conductances at finite and zero voltage, and thus disappears for a linear system. In the quantum regime, for temperatures much smaller than the frequency and the applied voltage, we find that the emission noise is exactly equal to the impurity partition noise. For the case of a weak impurity we expand our results for the AC conductance and the noise perturbatively. In particular, if the impurity is located in the middle of the wire or at one of the contacts, our calculations show that the noise exhibits oscillations with respect to frequency, whose period is directly related to the value of the interaction parameter $g$

Transport through quasi-ballistic quantum wires: the role of contacts

We model one-dimensional transport through each open channel of a quantum wire by a Luttinger liquid with three different interaction parameters for the leads, the contact regions and the wire, and with two barriers at the contacts. We show that this model explains several features of recent experiments, such as the flat conductance plateaux observed even at finite temperatures and for different lengths, and universal conductance corrections in different channels. We discuss the possibility of seeing resonance-like structures of a fully open channel at very low temperatures.Comment: revtex, 5 pages, 1 eps figure; clarifications added in light of new experiment

Institutional capacity building in rural WatSan sector in Afghanistan

The gravity of the problem of rural water supply and sanitation services low coverage (water supply 18% and sanitation 8%) and high mortality rate of children under 5 years (25%, half of which is caused by waterborne diseases and poor sanitation practice) has been recognized by the government of Afghanistan in its reconstruction Program. Accordingly to increase the coverage up to 50% by end of 2008, the construction of 100 000 water points and 1000 000 sanitary latrines and conducting 2.5 million household visits were approved. The Department of Rural Water Supply, Sanitation and Hygiene Promotion RuWatSan in the structure of Ministry of Rural Rehabilitation and Development, MRRD, is engaged in a nation wide program of support for the development of basic water supply and sanitation services through the Provincial Rural Rehabilitation and Development departments, PRRDs, NGOs, and the private sector. To fulfil this huge task it is imperative to have committed and capable partners from community level down to the government staff. This will happen through the capacity building program. This paper highlights the capacity building exercise so far covered in this regard by this department; pinpoint the ups and downs on the way and possible action in the future