High‐Performance Multilayer Encapsulation for Perovskite Photovoltaics

An encapsulation system comprising of a UV‐curable epoxy, a solution processed polymer interlayer, and a glass cover‐slip, is used to increase the stability of methylammonium lead triiodide (CH₃NH₃PbI₃) perovskite planar inverted architecture photovoltaic (PV) devices. It is found this encapsulation system acts as an efficient barrier to extrinsic degradation processes (ingress of moisture and oxygen), and that the polymer acts as a barrier that protects the PV device from the epoxy before it is fully cured. This results in devices that maintain 80% of their initial power conversion efficiency after 1000 h of AM1.5 irradiation. Such devices are used as a benchmark and are compared with devices having initially enhanced efficiency as a result of a solvent annealing process. It is found that such solvent‐annealed devices undergo enhanced burn‐in and have a reduced long‐term efficiency, a result demonstrating that initially enhanced device efficiency does not necessarily result in long‐term stability.     

The impacts of beavers Castor spp. on biodiversity and the ecological basis for their reintroduction to Scotland,UK

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Growth from Spores of Nonproteolytic Clostridium botulinum in Heat-Treated Vegetable Juice

Unheated spores of nonproteolytic Clostridium botulinum were able to lead to growth in sterile deoxygenated turnip, spring green, helda bean, broccoli, or potato juice, although the probability of growth was low and the time to growth was longer than the time to growth in culture media. With all five vegetable juices tested, the probability of growth increased when spores were inoculated into the juice and then heated for 2 min in a water bath at 80°C. The probability of growth was greater in bean or broccoli juice than in culture media following 10 min of heat treatment in these media. Growth was prevented by heat treatment of spores in vegetable juices or culture media at 80°C for 100 min. We show for the first time that adding heat-treated vegetable juice to culture media can increase the number of heat-damaged spores of C. botulinum that can lead to colony formation.     

A Cluster Randomized Trial of Routine HIV-1 Viral Load Monitoring in Zambia: Study Design,Implementation, and Baseline Cohort Characteristics

Background

The benefit of routine HIV-1 viral load (VL) monitoring of patients on antiretroviral therapy (ART) in resource-constrained settings is uncertain because of the high costs associated with the test and the limited treatment options. We designed a cluster randomized controlled trial to compare the use of routine VL testing at ART-initiation and at 3, 6, 12, and 18 months, versus our local standard of care (which uses immunological and clinical criteria to diagnose treatment failure, with discretionary VL testing when the two do not agree).

Methodology

Dedicated study personnel were integrated into public-sector ART clinics. We collected participant information in a dedicated research database. Twelve ART clinics in Lusaka, Zambia constituted the units of randomization. Study clinics were stratified into pairs according to matching criteria (historical mortality rate, size, and duration of operation) to limit the effect of clustering, and independently randomized to the intervention and control arms. The study was powered to detect a 36% reduction in mortality at 18 months.

Principal Findings

From December 2006 to May 2008, we completed enrollment of 1973 participants. Measured baseline characteristics did not differ significantly between the study arms. Enrollment was staggered by clinic pair and truncated at two matched sites.

Conclusions

A large clinical trial of routing VL monitoring was successfully implemented in a dynamic and rapidly growing national ART program. Close collaboration with local health authorities and adequate reserve staff were critical to success. Randomized controlled trials such as this will likely prove valuable in determining long-term outcomes in resource-constrained settings.

Trial Registration

Clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00929604","term_id":"NCT00929604"}}NCT00929604     

Evaluating the Potential for Harmonized Prediction and Comparison of Disposal‐Stage Greenhouse Gas Emissions for Biomaterial Products

The carbon footprint (CF) of biofuels and biomaterials is a barrier to their acceptance, yet the greenhouse gas emissions associated with disposing of biomaterials are frequently omitted from analyses. This article investigates whether harmonization is appropriate for calculating the importance of biomaterials’ disposal. This research shows that disposal stages could double a biomaterial's CF, or reduce it to the point that it could claim to be zero carbon. Incineration with combined heat and power coupled with on‐site energy production in the biorefinery are identified as prerequisites to being zero carbon. The article assesses the current UK waste infrastructure's ability to support a low‐carbon bio‐based future economy, and finds that presently it only achieves marginal net reductions when compared to landfill and so cannot be said to support low‐carbon biomaterials, though the article challenges the polluter pays principle where low‐carbon disposal infrastructure are not available. Reuse and recycling are shown to have the potential to offset all the emissions caused by landfill of biomaterials. However, the savings are not so great as to offset the biomaterial's upstream emissions. The study explores the ability to overcome the barriers to incorporating disposal into life cycle assessment while identifying limitations of using harmonization as an assessment method. Specifically, data availability and industry consensus are flagged as major barriers. The study also uses sensitivity analysis to investigate the influence of methodological choices, such as allowing additional reuse and recycling stages, classifying biomaterials into different types, and choosing between opposing allocation methods.     

Sampling efficacy for the red imported fire ant Solenopsis invicta (Hymenoptera: Formicidae)

Cost-effective detection of invasive ant colonies before establishment in new ranges is imperative for the protection of national borders and reducing their global impact. We examined the sampling efficiency of food-baits and pitfall traps (baited and nonbaited) in detecting isolated red imported fire ant (Solenopsis invicta Buren) nests in multiple environments in Gainesville, FL. Fire ants demonstrated a significantly higher preference for a mixed protein food type (hotdog or ground meat combined with sweet peanut butter) than for the sugar or water baits offered. Foraging distance success was a function of colony size, detection trap used, and surveillance duration. Colony gyne number did not influence detection success. Workers from small nests (0- to 15-cm mound diameter) traveled no >3 m to a food source, whereas large colonies (>30-cm mound diameter) traveled up to 17 m. Baited pitfall traps performed best at detecting incipient ant colonies followed by nonbaited pitfall traps then food baits, whereas food baits performed well when trying to detect large colonies. These results were used to create an interactive model in Microsoft Excel, whereby surveillance managers can alter trap type, density, and duration parameters to estimate the probability of detecting specified or unknown S. invicta colony sizes. This model will support decision makers who need to balance the sampling cost and risk of failure to detect fire ant colonies.     

Synthesis and in vitro evaluation of palladium(II) salicylaldiminato thiosemicarbazone complexes against Trichomonas vaginalis

Eight mononuclear Pd(II) complexes containing salicylaldiminato thiosemicarbazones (saltsc-R; where R = H (1), 3-OMe (2), 3-^tBu (3) and 5-Cl (4)) as dinegative tridentate ligands were prepared by the reaction of the corresponding thiosemicarbazone with the precursor Pd(L)₂Cl₂ (L = phosphatriazaadamantane or 4-picoline) in the presence of a weak base. These complexes (9-16) were characterised by a range of spectroscopic and analytical techniques including NMR spectroscopy and X-ray diffraction. These complexes along with four other Pd(II) analogues (5-8) were screened for activity in vitro against the Trichomonas vaginalis parasite. Preliminary results show that the type of ancillary ligand as well as the substituents on the aromatic ring of the salicylaldiminato thiosemicarbazone ligand influences the antiparasitic activity of these complexes.     

A theoretical account of cue averaging in the rodent head direction system

Head direction (HD) cell responses are thought to be derived from a combination of internal (or idiothetic) and external (or allothetic) sources of information. Recent work from the Jeffery laboratory shows that the relative influence of visual versus vestibular inputs upon the HD cell response depends on the disparity between these sources. In this paper, we present simulation results from a model designed to explain these observations. The model accurately replicates the Knight et al. data. We suggest that cue conflict resolution is critically dependent on plastic remapping of visual information onto the HD cell layer. This remap results in a shift in preferred directions of a subset of HD cells, which is then inherited by the rest of the cells during path integration. Thus, we demonstrate how, over a period of several minutes, a visual landmark may gain cue control. Furthermore, simulation results show that weaker visual landmarks fail to gain cue control as readily. We therefore suggest a second longer term plasticity in visual projections onto HD cell areas, through which landmarks with an inconsistent relationship to idiothetic information are made less salient, significantly hindering their ability to gain cue control. Our results provide a mechanism for reliability-weighted cue averaging that may pertain to other neural systems in addition to the HD system.