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NOURISH, Nutritional OUtcomes from a Randomised Investigation of Intradialytic oral nutritional Supplements in patients receiving Haemodialysis: a pilot randomised controlled trial

Background The study was done to assess the feasibility of conducting a trial evaluating the use of an intradialytic oral nutritional supplement (ONS) on nutritional status. Methods The study design is a single centre, parallel group, external pilot randomised controlled trial (RCT). The setting was at a haemodialysis unit in Sheffield, UK. The aim was to recruit 30 trial participants to allow at least 12 evaluable patients per arm, but the actual study sample consisted of 10 adults with a body mass index (BMI) ≤22 kg/m2, receiving thrice weekly haemodialysis. All participants received nutritional advice from a renal dietitian as per usual practice. The intervention included the provision of an intradialytic ONS. Feasibility outcomes included recruitment to time and retention of participants along with palatability of ONS. Secondary outcomes were clinical parameters to obtain variance and estimates of effect size to inform the sample size calculation for a definitive trial. Results Recruitment was undertaken for a fixed period of 6 weeks. Rates were lower than expected mainly due to ineligibility with only 7% of screened patients (19/265) being eligible and 4% (10/265) of these being recruited. Due to the small proportion of patients eligible for the trial, all haemodialysis patients at the specified unit were assessed for eligibility. Data completion rates were low for session questionnaires (23%). Sample sizes derived from variance in secondary outcome measure of handgrip strength and adjusted for a dropout rate of 20% indicate that 189 patients would be required for a definitive RCT, requiring 19 UK haemodialysis units to participate. Conclusions A definitive RCT is feasible with some adaptation to exclusion criteria and methodology. The exclusion criteria could be adapted to include an increase in upper limit for BMI. The use of questionnaires at each dialysis session may not be feasible but the inclusion of appetite and supplement consumption data collection at the main assessments would provide similar outcome data. Quality of life assessment using SF-12 would be acceptable

Integration of HIV Care with Primary Health Care Services: Effect on Patient Satisfaction and Stigma in Rural Kenya.

HIV departments within Kenyan health facilities are usually better staffed and equipped than departments offering non-HIV services. Integration of HIV services into primary care may address this issue of skewed resource allocation. Between 2008 and 2010, we piloted a system of integrating HIV services into primary care in rural Kenya. Before integration, we conducted a survey among returning adults ≥18-year old attending the HIV clinic. We then integrated HIV and primary care services. Three and twelve months after integration, we administered the same questionnaires to a sample of returning adults attending the integrated clinic. Changes in patient responses were assessed using truncated linear regression and logistic regression. At 12 months after integration, respondents were more likely to be satisfied with reception services (adjusted odds ratio, aOR 2.71, 95% CI 1.32-5.56), HIV education (aOR 3.28, 95% CI 1.92-6.83), and wait time (aOR 1.97 95% CI 1.03-3.76). Men's comfort with receiving care at an integrated clinic did not change (aOR = 0.46 95% CI 0.06-3.86). Women were more likely to express discomfort after integration (aOR 3.37 95% CI 1.33-8.52). Integration of HIV services into primary care services was associated with significant increases in patient satisfaction in certain domains, with no negative effect on satisfaction

Optomechanical deformation and strain in elastic dielectrics

Light forces induced by scattering and absorption in elastic dielectrics lead to local density modulations and deformations. These perturbations in turn modify light propagation in the medium and generate an intricate nonlinear response. We generalise an analytic approach where light propagation in one-dimensional media of inhomogeneous density is modelled as a result of multiple scattering between polarizable slices. Using the Maxwell stress tensor formalism we compute the local optical forces and iteratively approach self-consistent density distributions where the elastic back-action balances gradient- and scattering forces. For an optically trapped dielectric we derive the nonlinear dependence of trap position, stiffness and total deformation on the object's size and field configuration. Generally trapping is enhanced by deformation, which exhibits a periodic change between stretching and compression. This strongly deviates from qualitative expectations based on the change of photon momentum of light crossing the surface of a dielectric. We conclude that optical forces have to be treated as volumetric forces and that a description using the change of photon momentum at the surface of a medium is inappropriate

Poynting's theorem for planes waves at an interface: a scattering matrix approach

We apply the Poynting theorem to the scattering of monochromatic electromagnetic planes waves with normal incidence to the interface of two different media. We write this energy conservation theorem to introduce a natural definition of the scattering matrix S. For the dielectric-dielectric interface the balance equation lead us to the energy flux conservation which express one of the properties of S: it is a unitary matrix. For the dielectric-conductor interface the scattering matrix is no longer unitary due to the presence of losses at the conductor. However, the dissipative term appearing in the Poynting theorem can be interpreted as a single absorbing mode at the conductor such that a whole S, satisfying flux conservation and containing this absorbing mode, can be defined. This is a simplest version of a model introduced in the current literature to describe losses in more complex systems.Comment: 5 pages, 3 figures, submitted to Am. J. Phy

An atom interferometer enabled by spontaneous decay

We investigate the question whether Michelson type interferometry is possible if the role of the beam splitter is played by a spontaneous process. This question arises from an inspection of trajectories of atoms bouncing inelastically from an evanescent-wave (EW) mirror. Each final velocity can be reached via two possible paths, with a {\it spontaneous} Raman transition occurring either during the ingoing or the outgoing part of the trajectory. At first sight, one might expect that the spontaneous character of the Raman transfer would destroy the coherence and thus the interference. We investigated this problem by numerically solving the Schr\"odinger equation and applying a Monte-Carlo wave-function approach. We find interference fringes in velocity space, even when random photon recoils are taken into account.Comment: 6 pages, 5 figures, we clarified the semiclassical interpretation of Fig.

Accelerated Detector - Quantum Field Correlations: From Vacuum Fluctuations to Radiation Flux

In this paper we analyze the interaction of a uniformly accelerated detector with a quantum field in (3+1)D spacetime, aiming at the issue of how kinematics can render vacuum fluctuations the appearance of thermal radiance in the detector (Unruh effect) and how they engender flux of radiation for observers afar. Two basic questions are addressed in this study: a) How are vacuum fluctuations related to the emitted radiation? b) Is there emitted radiation with energy flux in the Unruh effect? We adopt a method which places the detector and the field on an equal footing and derive the two-point correlation functions of the detector and of the field separately with full account of their interplay. From the exact solutions, we are able to study the complete process from the initial transient to the final steady state, keeping track of all activities they engage in and the physical effects manifested. We derive a quantum radiation formula for a Minkowski observer. We find that there does exist a positive radiated power of quantum nature emitted by the detector, with a hint of certain features of the Unruh effect. We further verify that the total energy of the dressed detector and a part of the radiated energy from the detector is conserved. However, this part of the radiation ceases in steady state. So the hint of the Unruh effect in radiated power is actually not directly from the energy flux that the detector experiences in Unruh effect. Since all the relevant quantum and statistical information about the detector (atom) and the field can be obtained from the results presented here, they are expected to be useful, when appropriately generalized, for addressing issues of quantum information processing in atomic and optical systems, such as quantum decoherence, entanglement and teleportation.Comment: 24 pages, 11 figures, new results and comments added in Secs.VI and VII, with other corresponding change

A k-shell decomposition method for weighted networks

We present a generalized method for calculating the k-shell structure of weighted networks. The method takes into account both the weight and the degree of a network, in such a way that in the absence of weights we resume the shell structure obtained by the classic k-shell decomposition. In the presence of weights, we show that the method is able to partition the network in a more refined way, without the need of any arbitrary threshold on the weight values. Furthermore, by simulating spreading processes using the susceptible-infectious-recovered model in four different weighted real-world networks, we show that the weighted k-shell decomposition method ranks the nodes more accurately, by placing nodes with higher spreading potential into shells closer to the core. In addition, we demonstrate our new method on a real economic network and show that the core calculated using the weighted k-shell method is more meaningful from an economic perspective when compared with the unweighted one.Comment: 17 pages, 6 figure

Memory effects in response functions of driven vortex matter

Vortex flow in driven type II superconductors shows strong memory and history dependent effects. Here, we study a schematic microscopic model of driven vortices to propose a scenario for a broad set of these kind of phenomena ranging from ``rejuvenation'' and ``stiffening'' of the system response, to ``memory'' and ``irreversibility'' in I-V characteristics

A task and performance analysis of endoscopic submucosal dissection (ESD) surgery

BACKGROUND: ESD is an endoscopic technique for en bloc resection of gastrointestinal lesions. ESD is a widely-used in Japan and throughout Asia, but not as prevalent in Europe or the US. The procedure is technically challenging and has higher adverse events (bleeding, perforation) compared to endoscopic mucosal resection. Inadequate training platforms and lack of established training curricula have restricted its wide acceptance in the US. Thus, we aim to develop a Virtual Endoluminal Surgery Simulator (VESS) for objective ESD training and assessment. In this work, we performed task and performance analysis of ESD surgeries. METHODS: We performed a detailed colorectal ESD task analysis and identified the critical ESD steps for lesion identification, marking, injection, circumferential cutting, dissection, intraprocedural complication management, and post-procedure examination. We constructed a hierarchical task tree that elaborates the order of tasks in these steps. Furthermore, we developed quantitative ESD performance metrics. We measured task times and scores of 16 ESD surgeries performed by four different endoscopic surgeons. RESULTS: The average time of the marking, injection, and circumferential cutting phases are 203.4 (σ: 205.46), 83.5 (σ: 49.92), 908.4 s. (σ: 584.53), respectively. Cutting the submucosal layer takes most of the time of overall ESD procedure time with an average of 1394.7 s (σ: 908.43). We also performed correlation analysis (Pearson's test) among the performance scores of the tasks. There is a moderate positive correlation (R = 0.528, p = 0.0355) between marking scores and total scores, a strong positive correlation (R = 0.7879, p = 0.0003) between circumferential cutting and submucosal dissection and total scores. Similarly, we noted a strong positive correlation (R = 0.7095, p = 0.0021) between circumferential cutting and submucosal dissection and marking scores. CONCLUSIONS: We elaborated ESD tasks and developed quantitative performance metrics used in analysis of actual surgery performance. These ESD metrics will be used in future validation studies of our VESS simulator