Resonant photo-thermal conversion for sub-terahertz imaging

An original design of generic interest is proposed for fast imaging, in the field of sub-terahertz frequencies, by means of resonant coupling between an ultra-thin photo-thermal converter and a metallic grid upstream an infrared camera. The material is a sheet of polyimide material with a high content of absorptive carbon inclusions. We make use of the large difference between the IR and THz wavelengths in a quarter-wave planar geometry, to ensure a highly efficient and stable conversion process. A complete setup has been implemented for demonstration purposes, using the beam from a Gunn diode at 110 GHz. Experimental results are in good agreement with the predictions from the numerical model, which helps to validate the concept and the requirements for geometrical adjustment

Determinants of farmer adoption of organic production methods in the fresh-market produce sector in California: A logistic regression analysis

This research uses binomial and multinomial logistic regression models to identify the factors that influence farmers adoption of organic technology. Using a sample of 175 farmers growing fresh-market produce in three California counties, the first model examines farmers choice between conventional-only and organic-only production. The second model compares conventional-only and "dual-method" (combined conventional and organic) production, while the third model employs all three choices in a multinomial model. These results, which indicate that gross sales, direct marketing, number of crops and acres, farmer age, and computer usage are significant determinants, have implications on policies that regulate the organic foods sector.Production Economics,

Slow life history leaves endangered snake vulnerable to illegal collecting.

Global wildlife trade is a multibillion-dollar industry and a significant driver of vertebrate extinction risk. Yet, few studies have quantified the impact of wild harvesting for the illicit pet trade on populations. Long-lived species, by virtue of their slow life history characteristics, may be unable to sustain even low levels of collecting. Here, we assessed the impact of illegal collecting on populations of endangered broad-headed snakes (Hoplocephalus bungaroides) at gated (protected) and ungated (unprotected) sites. Because broad-headed snakes are long-lived, grow slowly and reproduce infrequently, populations are likely vulnerable to increases in adult mortality. Long-term data revealed that annual survival rates of snakes were significantly lower in the ungated population than the gated population, consistent with the hypothesis of human removal of snakes for the pet trade. Population viability analysis showed that the ungated population has a strongly negative population growth rate and is only prevented from ultimate extinction by dispersal of small numbers of individuals from the gated population. Sensitivity analyses showed that the removal of a small number of adult females was sufficient to impose negative population growth and suggests that threatened species with slow life histories are likely to be especially vulnerable to illegal collecting

How does moulage contribute to medical students' perceived engagement in simulation?:A mixed-methods pilot study

Introduction: Moulage is used frequently in simulation, with emerging evidence for its use in fields such as paramedicine, radiography and dermatology. It is argued that moulage adds to realism in simulation, although recent work highlighted the ambiguity of moulage practice in simulation. In the absence of knowledge, this study sought to explore the impact of highly authentic moulage on engagement in simulation.Methods: We conducted a randomised mixed-methods study exploring undergraduate medical students' perception of engagement in relation to the authenticity moulage. Participants were randomised to one of three groups: control (no moulage, narrative only), low authenticity (LowAuth) or high authenticity (HighAuth). Measures included self-report of engagement, the Immersion Scale Reporting Instrument (ISRI), omission of treatment actions, time-to-treat and self-report of authenticity. In combination with these objective measures, we utilised the Stimulated Recall (SR) technique to conduct interviews immediately following the simulation.Results: A total of 33 medical students participated in the study. There was no statistically significant difference between groups on the overall ISRI score. There were statistically significant results between groups on the self-reported engagement measure, and on the treatment actions, time-to-treat measures and the rating of authenticity. Four primary themes ((1) the rules of simulation, (2) believability, (3) consistency of presentation, (4) personal knowledge ) were extracted from the interview analysis, with a further 9 subthemes identified ((1) awareness of simulating, (2) making sense of the context (3) hidden agendas, (4) between two places, (5) dismissing, (6) person centredness, (7) missing information (8) level of training (9) previous experiences).Conclusions: Students rate moulage authenticity highly in simulations. The use of high-authenticity moulage impacts on their prioritisation and task completion. Although the slower performance in the HighAuth group did not have impact on simulated treatment outcomes, highly authentic moulage may be a stronger predictor of performance. Highly authentic moulage is preferable on the basis of optimising learning conditions.</p

Thermodiffusion in model nanofluids by molecular dynamics simulations

In this work, a new algorithm is proposed to compute single particle (infinite dilution) thermodiffusion using Non-Equilibrium Molecular Dynamics simulations through the estimation of the thermophoretic force that applies on a solute particle. This scheme is shown to provide consistent results for simple Lennard-Jones fluids and for model nanofluids (spherical non-metallic nanoparticles + Lennard-Jones fluid) where it appears that thermodiffusion amplitude, as well as thermal conductivity, decrease with nanoparticles concentration. Then, in nanofluids in the liquid state, by changing the nature of the nanoparticle (size, mass and internal stiffness) and of the solvent (quality and viscosity) various trends are exhibited. In all cases the single particle thermodiffusion is positive, i.e. the nanoparticle tends to migrate toward the cold area. The single particle thermal diffusion 2 coefficient is shown to be independent of the size of the nanoparticle (diameter of 0.8 to 4 nm), whereas it increases with the quality of the solvent and is inversely proportional to the viscosity of the fluid. In addition, this coefficient is shown to be independent of the mass of the nanoparticle and to increase with the stiffness of the nanoparticle internal bonds. Besides, for these configurations, the mass diffusion coefficient behavior appears to be consistent with a Stokes-Einstein like law

Local authority responses to people with NRPF during the pandemic: research report

Migrants with ‘no recourse to public funds’ (NRPF) are at high risk of destitution due to their exclusion from most welfare benefits and statutory housing support. This is a longstanding issue that has been highlighted by campaigners, academics and the migration sector. This report examines how local authorities in England responded to people with NRPF during the COVID-19 pandemic. It highlights systemic issues with access to support for people with NRPF and shows how provision varied considerably across England (most notably in the case of single adults with NRPF who would not normally be eligible for support but were included in the COVID-19 homelessness response) and even within individual local authorities. The COVID-19 pandemic has made life significantly more difficult and precarious for people with NRPF. Many have lost income, employment and accommodation, while non-statutory support services have been forced to close. The number of people with NRPF in need of assistance to meet their basic needs has increased. Our research indicates that people with NRPF are more likely to become seriously ill or die if they contract COVID-19. Despite this, it has been difficult for many people with NRPF to access the help they need, including adequate food, shelter and subsistence support, during this public health crisis. Local authorities have statutory duties towards two categories of people with NRPF: families with ‘children in need’; and adults with care needs. There are, however, significant variations in how these duties are implemented, with many migrants in need of support unable to access their entitlements under normal (pre-pandemic) circumstances. A key problem in this area is that local authorities are not funded by central government to provide support to people with NRPF - an issue that has been consistently raised by rights advocates. This issue became more urgent during the pandemic as local authorities were called upon by central government to provide support to a third group of people with NRPF who would not normally be eligible for assistance: single homeless adults without care needs. Our research shows that, while some councils put in place effective emergency support for this group, the England-wide response of local authorities was frequently characterised by confusion, a lack of information about support options, the ‘gatekeeping’ of access to accommodation, and gaps in essential provision (e.g. food). Our research focuses on the period during which the UK was in ‘lockdown’. But the problems we highlight in this report have by no means come to an end. Local authorities continue to be underfunded and the destitution experienced by people with NRPF has not abated. It is unclear what will happen to homeless adults with NRPF who have no statutory entitlement to support as public- health concerns subside. Our research indicates that while some local authorities are trying to respond to this issue in a way that respects people’s rights and dignity, others do not want to continue to support people with NRPF, with a number planning to resort to so-called ‘voluntary returns’ or ‘reconnection’. In the view of many of our research participants, only an urgent end to the NRPF system can adequately address the problems that have been highlighted by COVID-19

Improving the Isotretinoin Photostability by Incorporating in Microemulsion Matrix

The present paper demonstrates the increased photostability of isotretinoin when loaded in microemulsion. The photodegradation of isotretinoin, in methanol and microemulsion formulation was studied under direct sun light. The photodegradation process was monitored by UV spectrophotometry. In methanol solution, isotretinoin undergoes complete photodegradation just within a few minutes of light exposure. Isotretinoin incorporated in microemulsion formulation showed an increased stability in comparison to the methanol solutions. In particular for isotretinoin, a residual concentration of 75% was still present after a light irradiance versus a residual value of just 16% measured at the same time in methanol solution. Further, degradation kinetic parameters of isotretinoin-loaded microemulsion formulation were demonstrated increase isotretinoin half-life about five-times in comparison with a methanol solution under a direct sun light

A case of bullous Sézary syndrome

Sézary syndrome is a rare leukemic subtype of cutaneous T cell lymphoma that is characterized by erythroderma, lymphadenopathy, and malignant T cells in the peripheral blood. Poor prognostic factors of Sézary syndrome include advanced disease stage, older age at onset, and large cell transformation. Presentation with bullous lesions, though rare, has been reported in a few patients. We present an elderly woman with bullous Sézary syndrome who presented with a two-month history of progressive rash. Upon admission, the patient had pruritic, erythematous, edematous plaques with overlying flaccid bullae and erosions involving the scalp, neck, torso, and extremities. Despite treatment, the patient died two months after presentation. Although rare, bullous lesions associated with Sézary syndrome may indicate poor prognosis

Measurements of industrial emissions of alkenes in Texas using the solar occultation flux method

Solar occultation flux (SOF) measurements of alkenes have been conducted to identify and quantify the largest emission sources in the vicinity of Houston and in SE Texas during September 2006 as part of the TexAQS 2006 campaign. The measurements have been compared to emission inventories and have been conducted in parallel with airborne plume studies. The SOF measurements show that the hourly gas emissions from the large petrochemical and refining complexes in the Houston Ship Channel area and Mount Belvieu during September 2006 corresponded to 1250 +/- 180 kg/h of ethene and 2140 +/- 520 kg/h of propene, with an estimated uncertainty of about 35%. This can be compared to the 2006 emission inventory value for ethene and propene of 145 +/- 4 and 181 +/- 42 kg/h, respectively. On average, for all measurements during the campaign, the discrepancy factor is 10.2(+ 8,-5) for ethene and 11.7(+ 7,-4) for propene. The largest emission source was Mount Belvieu, NE of the Houston Ship Channel, with ethene and propene emissions corresponding to 440 +/- 130 kg/h and 490 +/- 190 kg/h, respectively. Large variability of propene was observed from several petrochemical industries, for which the largest reported emission sources are flares. The SOF alkene emissions agree within 50% with emissions derived from airborne measurements at three different sites. The airborne measurements also provide support to the SOF error budget