Near-UV to near-IR disk-averaged Earth's reflectance spectra

We report 320 to 1020nm disk-averaged Earth reflectance spectra obtained from Moon's Earthshine observations with the EMMI spectrograph on the NTT at ESO La Silla (Chile). The spectral signatures of Earth atmosphere and ground vegetation are observed. A vegetation red-edge of up to 9% is observed on Europe and Africa and ~2% upon Pacific Ocean. The spectra also show that Earth is a blue planet when Rayleigh scattering dominates, or totally white when the cloud cover is large.Comment: Proceeding of an oral prensentation at the UAI No200 Colloquiu

Human resource development and antiretroviral treatment in Free State province, South Africa

<p>Abstract</p> <p>Background</p> <p>In common with other developing countries, South Africa's public health system is characterised by human resource shortfalls. These are likely to be exacerbated by the escalating demand for HIV care and a large-scale antiretroviral therapy (ART) programme. Focusing on professional nurses, the main front-line providers of primary health care in South Africa, we studied patterns of planning, recruitment, training and task allocation associated with an expanding ART programme in the districts of one province, the Free State.</p> <p>Methods</p> <p>Data collection included an audit of professional nurse posts created and filled following the introduction of the ART programme, repeated surveys of facilities providing ART over two years to assess the deployment of staff, and secondary data analysis of government personnel databases to track broader patterns of recruitment and training.</p> <p>Results</p> <p>Although a substantial number of new professional nurse posts were established for the ART programme in the Free State, nearly 80% of these posts were filled by nurses transferring from other programmes within the same facility or from facilities within the same district, rather than by new recruits. From the beginning, ART nurse posts tended to be graded at a senior level, and later, in an effort to recruit professional nurses for the ART programme, the majority (54.6%) of nurses entering the programme were promoted to a senior level. The vacancy rate of nurse ART posts was significantly lower than that of other posts in the primary health care (PHC) system (15.7% vs 37.1%). Nursing posts in urban ART facilities were more easily filled than those in rural areas, exacerbating existing imbalances. The shift of nurses into the ART programme was partially compensated for by the appointment of additional support staff, task shifting to community health workers, and a large investment in training of PHC workers. However, the use of less-trained, mid-level enrolled nurses and nursing assistants in the ART programme remained low.</p> <p>Conclusion</p> <p>The introduction of the ART programme has revealed both strengths and weaknesses of human resource development in one province of South Africa. Without concerted efforts to increase the supply of key health professionals, accompanied by changes in the deployment of health workers, the core goals of the ART programme – i.e. providing universal access to ART and strengthening the health system – will not be achieved.</p

Near-UV to near-IR disk-averaged Earth's spectra from Moon's Earthshine observations

We discuss a series of Earthshine spectra obtained with the NTT/EMMI instrument between 320nm and 1020nm with a resolution of R~450 in the blue and R~250 in the red. These ascending and descending Moon's Earthshine spectra taken from Chile give disk-averaged spectra for two different Earth's phases. The spectra show the ozone (Huggins and Chappuis bands), oxygen and water vapour absorption bands, and also the stronger Rayleigh scattering in the blue. Removing the known telluric absorptions reveals a spectral feature around 700nm which is attributed to the vegetation stronger reflectivity in the near-IR, so-called vegetation red-edge.Comment: 2 pages, 1 figure, proceedings from a poster at 'Semaine de l'Astrophysique Francaise', 27th june-1st july 2005, Strasbour

Discovery of an 86 AU Radius Debris Ring Around HD 181327

HST/NICMOS PSF-subtracted coronagraphic observations of HD 181327 have revealed the presence of a ring-like disk of circumstellar debris seen in 1.1 micron light scattered by the disk grains, surrounded by a di use outer region of lower surface brightness. The annular disk appears to be inclined by 31.7 +/- 1.6 deg from face on with the disk major axis PA at 107 +/-2 deg . The total 1.1 micron flux density of the light scattered by the disk (at 1.2" < r < 5.0") of 9.6 mJy +/- 0.8 mJy is 0.17% +/- 0.015% of the starlight. Seventy percent of the light from the scattering grains appears to be confined in a 36 AU wide annulus centered on the peak of the radial surface brightness (SB) profile 86.3 +/- 3.9 AU from the star, well beyond the characteristic radius of thermal emission estimated from IRAS and Spitzer flux densities assuming blackbody grains (~ 22 AU). The light scattered by the ring appears bilaterally symmetric, exhibits directionally preferential scattering well represented by a Henyey-Greenstein scattering phase function with g = 0.30 +/- 0.03, and has an azimuthally medianed SB at the 86.3 AU radius of peak SB of 1.00 +/- 0.07 mJy arcsec^-2. No photocentric offset is seen in the ring relative to the position of the central star. A low surface brightness diffuse halo is seen in the NICMOS image to a distance of ~ 4" Deeper 0.6 micron HST/ACS PSF-subtracted coronagraphic observations reveal a faint outer nebulosity, asymmetrically brighter to the North of the star. We discuss models of the disk and properties of its grains, from which we infer a maximum vertical scale height of 4 - 8 AU at the 87.6 AU radius of maximum surface density, and a total maximum dust mass of collisionally replenished grains with minimum grain sizes of ~ 1 micron of ~ 4 M(moon).Comment: 45 pages, 15 figures, accepted for publication in Ap

Co-occurrence, ecological profiles and geographical distribution based on unique molecular identifiers of the common freshwater diatoms Fragilaria and Ulnaria

Diatom taxonomy has evolved in recent years, with many new species described and new approaches such as molecular genetics showing the existence of cryptic diversity within currently accepted species. This cryptic diversity is not well understood even for common freshwater genera such as Fragilaria and Ulnaria. The purpose of our study was to define taxon-specific ecological profiles and geographical distributions for unique molecular identifiers (amplicon sequence variants, ASVs) linked to curated taxonomy for these genera. Our goal is to contribute to the development of ecological assessment methods, and to the understanding why we often observe so many diatom species co-occurring in a single sample. We filtered a large (770 samples) metabarcoding dataset with linked environmental data covering several countries in Europe for genetic variants (ASVs) assigned to currently accepted species of our target genera. We studied the geographical distribution of the ASVs, and tested for ASV-pair co-occurrence. We modelled ASV-specific preferences for pH, alkalinity, total nitrogen, total phosphorus and conductivity, and analysed their preference for lakes or streams as habitat. Our study confirmed that there seems to be no general geographical barrier for the distribution of freshwater benthic diatom ASVs in Europe, but that dispersal is not rapid enough to hide historical events. The Fragilaria and Ulnaria ASVs in our study showed considerable overlap in geographical distribution, habitat and ecological preferences. We found evidence that only large differences in preferences for the analysed water chemistry variables prevented the co-occurrence of ASVs at the same sites. Instead, Fragilaria and Ulnaria ASVs co-occurred frequently in samples. We found subtle differences in ecological preferences for some ASV pairs, which might in part explain the co-occurrence by the avoidance of direct competition. However, the great overlap in distribution and ecological preferences suggests that other factors not studied here were also responsible for the observed co-occurrences and high richness of ASVs found at many sites. To our knowledge, we are the first to use ASVs in combination with a curated taxonomy to understand co-occurrence, specific ecological profiles and large-scale geographical distribution for unique identifiers not biased by the quality of reference databases, clustering methods, or non-harmonized morphological identification. Thus, our results can now be used in subsequent projects to interpret ASV occurrences, e.g. for development of ecological assessment methods

The SARS algorithm: detrending CoRoT light curves with Sysrem using simultaneous external parameters

Surveys for exoplanetary transits are usually limited not by photon noise but rather by the amount of red noise in their data. In particular, although the CoRoT spacebased survey data are being carefully scrutinized, significant new sources of systematic noises are still being discovered. Recently, a magnitude-dependant systematic effect was discovered in the CoRoT data by Mazeh & Guterman et al. and a phenomenological correction was proposed. Here we tie the observed effect a particular type of effect, and in the process generalize the popular Sysrem algorithm to include external parameters in a simultaneous solution with the unknown effects. We show that a post-processing scheme based on this algorithm performs well and indeed allows for the detection of new transit-like signals that were not previously detected.Comment: MNRAS accepted. 5 pages, 3 figure

The Disability discrimination Act and Developments in Accessible Public Transport in the UK

Objective: To determine the relation between time to surgery (TTS) after neoadjuvant chemoradiotherapy (nCRT) and pathologically complete response (pCR), surgical outcome, and survival in patients with esophageal cancer. Background: Standard treatment for potentially curable esophageal cancer is nCRT plus surgery after 4 to 6 weeks. In rectal cancer patients, evidence suggests that prolonged TTS is associated with a higher pCR rate and possibly with better survival. Methods: We identified patients treated with nCRT plus surgery for esophageal cancer between 2001 and 2011. TTS (last day of radiotherapy to day of surgery) varied mainly for logistical reasons. Minimal follow-up was 24 months. The effect of TTS on pCR rate, postoperative complications, and survival was determined with (ordinal) logistic, linear, and Cox regression, respectively. Results: In total, 325 patients were included. Median TTS was 48 days (p25-p75=40-60). After 45 days, TTSwas associated with an increased probability of pCR [odds ratio (OR) = 1.35 per additional week of TSS, P = 0.0004] and a small increased risk of postoperative complications (OR = 1.20, P <0.001). Prolonged TTS had no effect on disease-free and overall survivals (HR = 1.00 and HR = 1.06 per additional week of TSS, P = 0.976 and P = 0.139, respectively). Conclusions: Prolonged TTS after nCRT increases the probability of pCR and is associated with a slightly increased probability of postoperative complications, without affecting disease-free and overall survivals. We conclude that TTS can be safely prolonged from the usual 4 to 6 weeks up to at least 12 weeks, which facilitates a more conservative wait-and-see strategy after neoadjuvant chemoradiotherapy to be teste

Synthesis, base pairing properties and trans-lesion synthesis by reverse transcriptases of oligoribonucleotides containing the oxidatively damaged base 5-hydroxycytidine

The synthesis of a caged RNA phosphoramidite building block containing the oxidatively damaged base 5-hydroxycytidine (5-HOrC) has been accomplished. To determine the effect of this highly mutagenic lesion on complementary base recognition and coding properties, this building block was incorporated into a 12-mer oligoribonucleotide for Tm and CD measurements and a 31-mer template strand for primer extension experiments with HIV-, AMV- and MMLV-reverse transcriptase (RT). In UV-melting experiments, we find an unusual biphasic transition with two distinct Tm's when 5-HOrC is paired against a DNA or RNA complement with the base guanine in opposing position. The higher Tm closely matches that of a C-G base pair while the lower is close to that of a C-A mismatch. In single nucleotide extension reactions, we find substantial misincorporation of dAMP and to a lesser extent dTMP, with dAMP almost equaling that of the parent dGMP in the case of HIV-RT. A working hypothesis for the biphasic melting transition does not invoke tautomeric variability of 5-HOrC but rather local structural perturbations of the base pair at low temperature induced by interactions of the 5-HO group with the phosphate backbone. The properties of this RNA damage is discussed in the context of its putative biological function