Observations of H1426+428 with HEGRA -- Observations in 2002 and reanalysis of 1999&2000 data

The HEGRA system of imaging air Cherenkov telescopes has been used to observe the BL Lac object H1426+428 ($z=0.129$) for 217.5 hours in 2002. In this data set alone, the source is detected at a confidence level of $5.3~\sigma$, confirming this object as a TeV source. The overall flux level during the observations in 2002 is found to be a factor of $\approx 2.5$ lower than during the previous observations by HEGRA in 1999&2000. A new spectral analysis has been carried out, improving the signal-to-noise ratio at the expense of a slightly increased systematic uncertainty and reducing the relative energy resolution to $\Delta E/E\le 12$ over a wide range of energies. The new method has also been applied to the previously published data set taken in 1999 and 2000, confirming the earlier claim of a flattening of the energy spectrum between 1 and 5 TeV. The data set taken in 2002 shows again a signal at energies above 1 TeV. We combine the energy spectra as determined by the CAT and VERITAS groups with our reanalyzed result of the 1999&2000 data set and apply a correction to account for effects of absorption of high energy photons on extragalactic background light in the optical to mid infrared band. The shape of the inferred source spectrum is mostly sensitive to the characteristics of the extragalactic background light between wavelengths of 1 and 15~$\mu$mComment: 12 pages, 4 Figures, submitted to A&

Health seeking and access to care for children with suspected dengue in Cambodia: An ethnographic study

RefereedBackground: The continuing contribution of dengue fever to the hospitalization and deaths in hospital of infants and small children in Cambodia is associated with delays in presentation for medical attention, diagnosis and appropriate care. It is important to identify the reasons that influence these delays, in order to develop appropriate interventions to redress the impact of dengue. Methods: Data on health seeking were collected during an ethnographic study conducted in two villages in the eastern province of Kampong Cham, Cambodia in 2004. Interviews were conducted with mothers whose children had been infected with suspected dengue fever, or who had been sick for other reasons, in 2003 and 2004. Results: Women selected a therapeutic option based on perceptions of the severity of the child's condition, confidence in the particular modality, service or practitioner, and affordability of the therapy. While they knew what type of health care was required, poverty in combination with limited availability and perceptions of the poor quality of care at village health centers and public referral hospitals deterred them from doing so. Women initially used home remedies, then sought advice from public and private providers, shifting from one sector to another in a pragmatic response to the child's illness. Conclusion: The lack of availability of financial resources for poor people and their continuing lack of confidence in the care provided by government centres combine to delay help seeking and inappropriate treatment of children sick with dengue.UNICEF–UNDP–World Bank–WHO Special Programme for Research and Training in Tropical Diseases (WHO/TDR

Cu(110) surface in hydrochloric acid solution: Potential dependent chloride adsorption and surface restructuring

Using cyclic voltammetry (CV), reflectance anisotropy spectroscopy (RAS), and in situ electrochemical scanning tunneling microscopy (EC-STM), we have studied the structure and structural transitions at a Cu(110) electrode surface in 10 mM HCl solution as a function of the applied electrode potential. While at potentials lower than -550 mV vs Ag/AgCl the in situ STM images reveal the adsorbate-free, unreconstructed structure of the Cu(110) surface, at increasing potential ≤ -550 mV chloride adsorption, as indicated by CV, leads first to the formation of grooves followed by the growth of added stripes. Both are aligned in the [001] direction as shown by EC-STM - and supported by ex situ low energy electron diffraction (LEED) - and are the result of a severe but fully reversible restructuring of the surface. This faceting is accompanied by an optical anisotropy peak in RAS centered at about 500 nm (2.48 eV), having a maximum when the linearly polarized light is aligned along the [110] direction, i.e., perpendicular to the stripes detected with in situ STM under the same conditions. By cycling the electrode potential through a full cyclic voltammogram and monitoring simultaneously the RAS signal we obtain a hysteresis-like curve which supports a two-step kinetics of the restructuring process in agreement with the CV and STM data. The investigations demonstrate the power of combined RAS and in situ STM measurements to shine light on potential-driven processes at metal-electrolyte interfaces. (Graph Presented)