A new regional climate model for POLAR-CORDEX : evaluation of a 30-year hindcast with COSMO-CLM2 over Antarctica

Continent-wide climate information over the Antarctic Ice Sheet (AIS) is important to obtain accurate information of present climate and reduce uncertainties of the ice sheet mass balance response and resulting global sea level rise to future climate change. In this study, the COSMO-CLM2 Regional Climate Model is applied over the AIS and adapted for the specific meteorological and climatological conditions of the region. A 30-year hindcast was performed and evaluated against observational records consisting of long-term ground-based meteorological observations, automatic weather stations, radiosoundings, satellite records, stake measurements and ice cores. Reasonable agreement regarding the surface and upper-air climate is achieved by the COSMO-CLM2 model, comparable to the performance of other state-of-the-art climate models over the AIS. Meteorological variability of the surface climate is adequately simulated, and biases in the radiation and surface mass balance are small. The presented model therefore contributes as a new member to the COordinated Regional Downscaling EXperiment project over the AIS (POLAR-CORDEX) and the CORDEX-CORE initiative

Raman Spectroscopy of Mott insulator states in optical lattices

We propose and analyse a Raman spectroscopy technique for probing the properties of quantum degenerate bosons in the ground band of an optical lattice. Our formalism describes excitations to higher vibrational bands and is valid for deep lattices where a tight-binding approach can be applied to the describe the initial state of the system. In sufficiently deep lattices, localized states in higher vibrational bands play an important role in the system response, and shifts in resonant frequency of excitation are sensitive to the number of particles per site. We present numerical results of this formalism applied to the case of a uniform lattice deep in the Mott insulator regime.Comment: 10 pages, 3 figure

Cooling in strongly correlated optical lattices: prospects and challenges

Optical lattices have emerged as ideal simulators for Hubbard models of strongly correlated materials, such as the high-temperature superconducting cuprates. In optical lattice experiments, microscopic parameters such as the interaction strength between particles are well known and easily tunable. Unfortunately, this benefit of using optical lattices to study Hubbard models come with one clear disadvantage: the energy scales in atomic systems are typically nanoKelvin compared with Kelvin in solids, with a correspondingly miniscule temperature scale required to observe exotic phases such as d-wave superconductivity. The ultra-low temperatures necessary to reach the regime in which optical lattice simulation can have an impact-the domain in which our theoretical understanding fails-have been a barrier to progress in this field. To move forward, a concerted effort to develop new techniques for cooling and, by extension, techniques to measure even lower temperatures. This article will be devoted to discussing the concepts of cooling and thermometry, fundamental sources of heat in optical lattice experiments, and a review of proposed and implemented thermometry and cooling techniques.Comment: in review with Reports on Progress in Physic

Constraining the recent mass balance of Pine Island and Thwaites glaciers, West Antarctica, with airborne observations of snow accumulation

In Antarctica, uncertainties in mass input and output translate directly into uncertainty in glacier mass balance and thus in sea level impact. While remotely sensed observations of ice velocity and thickness over the major outlet glaciers have improved our understanding of ice loss to the ocean, snow accumulation over the vast Antarctic interior remains largely unmeasured. Here, we show that an airborne radar system, combined with ice-core glaciochemical analysis, provide the means necessary to measure the accumulation rate at the catchment-scale along the Amundsen Sea coast of West Antarctica. We used along-track radar-derived accumulation to generate a 1985–2009 average accumulation grid that resolves moderate- to large-scale features (>25 km) over the Pine Island–Thwaites glacier drainage system. Comparisons with estimates from atmospheric models and gridded climatologies generally show our results as having less accumulation in the lower-elevation coastal zone but greater accumulation in the interior. Ice discharge, measured over discrete time intervals between 1994 and 2012, combined with our catchment-wide accumulation rates provide an 18-year mass balance history for the sector. While Thwaites Glacier lost the most ice in the mid-1990s, Pine Island Glacier's losses increased substantially by 2006, overtaking Thwaites as the largest regional contributor to sea-level rise. The trend of increasing discharge for both glaciers, however, appears to have leveled off since 2008

Observed Reductions in Schistosoma mansoni Transmission from Large-Scale Administration of Praziquantel in Uganda: A Mathematical Modelling Study

To date schistosomiasis control programmes based on chemotherapy have largely aimed at controlling morbidity in treated individuals rather than at suppressing transmission. In this study, a mathematical modelling approach was used to estimate reductions in the rate of Schistosoma mansoni reinfection following annual mass drug administration (MDA) with praziquantel in Uganda over four years (2003-2006). In doing this we aim to elucidate the benefits of MDA in reducing community transmission.Age-structured models were fitted to a longitudinal cohort followed up across successive rounds of annual treatment for four years (Baseline: 2003, TREATMENT: 2004-2006; n = 1,764). Instead of modelling contamination, infection and immunity processes separately, these functions were combined in order to estimate a composite force of infection (FOI), i.e., the rate of parasite acquisition by hosts.MDA achieved substantial and statistically significant reductions in the FOI following one round of treatment in areas of low baseline infection intensity, and following two rounds in areas with high and medium intensities. In all areas, the FOI remained suppressed following a third round of treatment.This study represents one of the first attempts to monitor reductions in the FOI within a large-scale MDA schistosomiasis morbidity control programme in sub-Saharan Africa. The results indicate that the Schistosomiasis Control Initiative, as a model for other MDA programmes, is likely exerting a significant ancillary impact on reducing transmission within the community, and may provide health benefits to those who do not receive treatment. The results obtained will have implications for evaluating the cost-effectiveness of schistosomiasis control programmes and the design of monitoring and evaluation approaches in general

Listening to health workers: lessons from Eastern Uganda for strengthening the programme for the prevention of mother-to-child transmission of HIV

<p>Abstract</p> <p>Background</p> <p>The implementation and utilization of programmes for the prevention of mother-to-child transmission (PMTCT) of HIV in most low income countries has been described as sub-optimal. As planners and service providers, the views of health workers are important in generating priorities to improve the effectiveness of the PMTCT programme in Uganda. We explored the lessons learnt by health workers involved in the provision of PMTCT services in eastern Uganda to better understand what more needs to be done to strengthen the PMTCT programme.</p> <p>Methods</p> <p>A qualitative study was conducted at Mbale Regional Referral Hospital, The AIDS Support Organisation (TASO) Mbale and at eight neighbouring health centres in eastern Uganda, between January and May 2010. Data were collected through 24 individual interviews with the health workers involved in the PMTCT programme and four key informants (2 district officials and 2 officials from TASO). Data were analyzed using the content thematic approach. Study themes and sub-themes were identified following multiple reading of interview transcripts. Relevant quotations have been used in the presentation of study findings.</p> <p>Results</p> <p>The key lessons for programme improvement were: ensuring constant availability of critical PMTCT supplies, such as HIV testing kits, antiretroviral drugs (ARVs) for mothers and their babies, regular in-service training of health workers to keep them abreast with the rapidly changing knowledge and guidelines for PMTCT, ensuring that lower level health centres provide maternity services and ARVs for women in the PMTCT programme and provision of adequate facilities for effective follow-up and support for mothers.</p> <p>Conclusions</p> <p>The voices of health workers in this study revealed that it is imperative for government, civil society organizations and donors that the PMTCT programme addresses the challenges of shortage of critical PMTCT supplies, continuous health worker training and follow-up and support for mothers as urgent needs to strengthen the PMTCT programme.</p

The relationship between baseline Organizational Readiness to Change Assessment subscale scores and implementation of hepatitis prevention services in substance use disorders treatment clinics: a case study

<p>Abstract</p> <p>Background</p> <p>The Organizational Readiness to Change Assessment (ORCA) is a measure of organizational readiness for implementing practice change in healthcare settings that is organized based on the core elements and sub-elements of the Promoting Action on Research Implementation in Health Services (PARIHS) framework. General support for the reliability and factor structure of the ORCA has been reported. However, no published study has examined the utility of the ORCA in a clinical setting. The purpose of the current study was to examine the relationship between baseline ORCA scores and implementation of hepatitis prevention services in substance use disorders (SUD) clinics.</p> <p>Methods</p> <p>Nine clinic teams from Veterans Health Administration SUD clinics across the United States participated in a six-month training program to promote evidence-based practices for hepatitis prevention. A representative from each team completed the ORCA evidence and context subscales at baseline.</p> <p>Results</p> <p>Eight of nine clinics reported implementation of at least one new hepatitis prevention practice after completing the six-month training program. Clinic teams were categorized by level of implementation-high (n = 4) versus low (n = 5)-based on how many hepatitis prevention practices were integrated into their clinics after completing the training program. High implementation teams had significantly higher scores on the patient experience and leadership culture subscales of the ORCA compared to low implementation teams. While not reaching significance in this small sample, high implementation clinics also had higher scores on the research, clinical experience, staff culture, leadership behavior, and measurement subscales as compared to low implementation clinics.</p> <p>Conclusions</p> <p>The results of this study suggest that the ORCA was able to measure differences in organizational factors at baseline between clinics that reported high and low implementation of practice recommendations at follow-up. This supports the use of the ORCA to describe factors related to implementing practice recommendations in clinical settings. Future research utilizing larger sample sizes will be essential to support these preliminary findings.</p

Estimation of changes in the force of infection for intestinal and urogenital schistosomiasis in countries with Schistosomiasis Control Initiative-assisted programmes

The last decade has seen an expansion of national schistosomiasis control programmes in Africa based on large-scale preventative chemotherapy. In many areas this has resulted in considerable reductions in infection and morbidity levels in treated individuals. In this paper, we quantify changes in the force of infection (FOI), defined here as the per (human) host parasite establishment rate, to ascertain the impact on transmission of some of these programmes under the umbrella of the Schistosomiasis Control Initiative (SCI)

Phase II study of single agent capecitabine in the treatment of metastatic non-pancreatic neuroendocrine tumours

BACKGROUND: This study sought to determine the safety of single agent capecitabine, a pro-drug of 5FU, in patients with metastatic non-pancreatic neuroendocrine tumours (NETs). METHODS: Multicentre phase II, first-line study design. Oral capecitabine was administered on days 1-14 of 3-week cycles. RESULTS: Treatment was safe and well tolerated. Common toxicities were diarrhoea and fatigue. CONCLUSION: The study provides evidence to support the use of capecitabine as a substitute for infusional 5FU in the management of NETs