PrEP as a feature in the optimal landscape of combination HIV prevention in sub-Saharan Africa

INTRODUCTION: The new WHO guidelines recommend offering pre-exposure prophylaxis (PrEP) to people who are at substantial risk of HIV infection. However, where PrEP should be prioritised, and for which population groups, remains an open question. The HIV landscape in sub-Saharan Africa features limited prevention resources, multiple options for achieving cost saving, and epidemic heterogeneity. This paper examines what role PrEP should play in optimal prevention in this complex and dynamic landscape. METHODS: We use a model that was previously developed to capture subnational HIV transmission in sub-Saharan Africa. With this model, we can consider how prevention funds could be distributed across and within countries throughout sub-Saharan Africa to enable optimal HIV prevention (that is, avert the greatest number of infections for the lowest cost). Here, we focus on PrEP to elucidate where, and to whom, it would optimally be offered in portfolios of interventions (alongside voluntary medical male circumcision, treatment as prevention, and behaviour change communication). Over a range of continental expenditure levels, we use our model to explore prevention patterns that incorporate PrEP, exclude PrEP, or implement PrEP according to a fixed incidence threshold. RESULTS: At low-to-moderate levels of total prevention expenditure, we find that the optimal intervention portfolios would include PrEP in only a few regions and primarily for female sex workers (FSW). Prioritisation of PrEP would expand with increasing total expenditure, such that the optimal prevention portfolios would offer PrEP in more subnational regions and increasingly for men who have sex with men (MSM) and the lower incidence general population. The marginal benefit of including PrEP among the available interventions increases with overall expenditure by up to 14% (relative to excluding PrEP). The minimum baseline incidence for the optimal offer of PrEP declines for all population groups as expenditure increases. We find that using a fixed incidence benchmark to guide PrEP decisions would incur considerable losses in impact (up to 7%) compared with an approach that uses PrEP more flexibly in light of prevailing budget conditions. CONCLUSIONS: Our findings suggest that, for an optimal distribution of prevention resources, choices of whether to implement PrEP in subnational regions should depend on the scope for impact of other possible interventions, local incidence in population groups, and total resources available. If prevention funding were to become restricted in the future, it may be suboptimal to use PrEP according to a fixed incidence benchmark, and other prevention modalities may be more cost-effective. In contrast, expansions in funding could permit PrEP to be used to its full potential in epidemiologically driven prevention portfolios and thereby enable a more cost-effective HIV response across Africa

A novel system for spatial and temporal imaging of intrinsic plant water use efficiency

Instrumentation and methods for rapid screening and selection of plants with improved water use efficiency are essential to address current issues of global food and fuel security. A new imaging system that combines chlorophyll fluorescence and thermal imaging has been developed to generate images of assimilation rate (A), stomatal conductance (gs), and intrinsic water use efficiency (WUEi) from whole plants or leaves under controlled environmental conditions. This is the first demonstration of the production of images of WUEi and the first to determine images of gs from themography at the whole-plant scale. Data are presented illustrating the use of this system for rapidly and non-destructively screening plants for alterations in WUEi by comparing Arabidopsis thaliana mutants (OST1-1) that have altered WUEi driven by open stomata, with wild-type plants. This novel instrument not only provides the potential to monitor multiple plants simultaneously, but enables intra- and interspecies variation to be taken into account both spatially and temporally. The ability to measure A, gs, and WUEi progressively was developed to facilitate and encourage the development of new dynamic protocols. Images illustrating the instrument's dynamic capabilities are demonstrated by analysing plant responses to changing photosynthetic photon flux density (PPFD). Applications of this system will augment the research community's need for novel screening methods to identify rapidly novel lines, cultivars, or species with improved A and WUEi in order to meet the current demands on modern agriculture and food production. © The Author 2013. Published by Oxford University Press on behalf of the Society for Experimental Biology

Organic matter remineralization in marine sediments : A Pan-Arctic synthesis

Natural Environment Research Council (GrantNumber(s): NE/J023094/1; Grant recipient(s): Ursula Witte) ArcticNet (GrantNumber(s): Hotspot biodiversity project; Grant recipient(s): Philippe Archambault)Peer reviewedPublisher PD

Prospects for seasonal forecasting of iceberg distributions in the North Atlantic

An efficient approach to ocean–iceberg modelling provides a means for assessing prospects for seasonal forecasting of iceberg distributions in the northwest Atlantic, where icebergs present a hazard to mariners each spring. The stand-alone surface (SAS) module that is part of the Nucleus for European Modelling of the Ocean (NEMO) is coupled with the NEMO iceberg module (ICB) in a “SAS-ICB” configuration with horizontal resolution of 0.25°. Iceberg conditions are investigated for three recent years, 2013–2015, characterized by widely varying iceberg distributions. The relative simplicity of SAS-ICB facilitates efficient investigation of sensitivity to iceberg fluxes and prevailing environmental conditions. SAS-ICB is provided with daily surface ocean analysis fields from the global Forecasting Ocean Assimilation Model (FOAM) of the Met Office. Surface currents, temperatures and height together determine iceberg advection and melting rates. Iceberg drift is further governed by surface winds, which are updated every 3 h. The flux of icebergs from the Greenland ice sheet is determined from engineering control theory and specified as an upstream flux in the vicinity of Davis Strait for January or February. Simulated iceberg distributions are evaluated alongside observations reported and archived by the International Ice Patrol. The best agreement with observations is obtained when variability in both upstream iceberg flux and oceanographic/atmospheric conditions is taken into account. Including interactive icebergs in an ocean–atmosphere model with sufficient seasonal forecast skill, and provided with accurate winter iceberg fluxes, it is concluded that seasonal forecasts of spring/summer iceberg conditions for the northwest Atlantic are now a realistic prospect

Wolf Rock lighthouse: past developments and future survivability under wave loading

Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the waves. They were first constructed when approaches to wave loading and structural response were relatively unsophisticated, essentially learning from previous failures. Here, we chart the evolution of lighthouses on the Wolf Rock, situated between Land's End and the Isles of Scilly in the UK. The first empirical approaches are described, followed by design aspects of the present tower, informed by innovations developed on other rocky outcrops. We focus on a particular development associated with the automation of lighthouses: the helideck platform. The design concept is described and the structure then scrutinized for future survivability, using the latest structural modelling techniques of the entire lighthouse and helideck. Model validation data were obtained through a complex logistical field operation and experimental modal analysis. Extreme wave loading for the model required the identification of the 250-year return period wave using a Bayesian method with informative prior distributions, for two different scenarios (2017 and 2067). The structural models predict responses of the helideck to wave loading which is characterized by differential displacements of 0.093m (2017) and 0.115m (2067) with associated high tension forces and plastic strain.</p

Are female students in general and nursing students more ready for teamwork and interprofessional collaboration in healthcare?

<p>Abstract</p> <p>Background</p> <p>Interprofessional Education (IPE) is now spreading worldwide and many universities are now including IPE in their curricula. The aim of this study was to investigate whether or not such student characteristics as gender, previous working experience in healthcare, educational progress and features of the learning environment, such as educational programmes and curriculum design, have an impact on their open-mindedness about co-operation with other professions.</p> <p>Methods</p> <p>Medical and nursing students at two Swedish universities were invited to fill in the Readiness for Interprofessional Learning Scale (RIPLS). Totally, 955 students were invited and 70.2% (n = 670) participated in the study. A factor analysis of the RIPLS revealed four item groupings (factors) for our empirical data, but only one had sufficient internal consistency. This factor was labelled "Team Player".</p> <p>Results</p> <p>Regardless of the educational programme, female students were more positive to teamwork than male students. Nursing students in general displayed more positive beliefs about teamwork and collaboration than medical students. Exposure to different interprofessional curricula and previous exposure to interprofessional education were only to a minor extent associated with a positive attitude towards teamwork. Educational progress did not seem to influence these beliefs.</p> <p>Conclusions</p> <p>The establishment of interprofessional teamwork is a major challenge for modern healthcare. This study indicates some directions for more successful interprofessional education. Efforts should be directed at informing particularly male medical students about the need for teamwork in modern healthcare systems. The results also imply that study of other factors, such as the student's personality, is needed for fully understanding readiness for teamwork and interprofessional collaboration in healthcare. We also believe that the RIPL Scale still can be further adjusted.</p

Variation in Serripes groenlandicus (Bivalvia) growth in a Norwegian high-Arctic fjord : evidence for local- and large-scale climatic forcing

Author Posting. © Blackwell, 2006. This is the author's version of the work. It is posted here by permission of Blackwell for personal use, not for redistribution. The definitive version was published in Global Change Biology 12 (2006): 1595-1607, doi:10.1111/j.1365-2486.2006.01181.x.We examined the growth rate of the circumpolar Greenland Cockle (Serripes groenlandicus) over a period of 20 years (1983-2002) from Rijpfjord, a high-Arctic fjord in northeast Svalbard (80º10´N, 22°15´E). This period encompassed different phases of large-scale climatic oscillations with accompanying variations in local physical variables (temperature, atmospheric pressure, precipitation, sea ice cover), allowing us to analyze the linkage between growth rate, climatic oscillations, and their local physical and biological manifestations. Standard Growth Index (SGI), an ontogenetically-adjusted measure of annual growth, ranged from a low of 0.27 in 2002 up to 2.46 in 1996. Interannual variation in growth corresponded to the Arctic Climate Regime Index (ACRI), with high growth rates during the positive ACRI phase characterized by cyclonic ocean circulation and a warmer and wetter climate. Growth rates were influenced by local manifestations of the ACRI: positively correlated with precipitation and to a lesser extent negatively correlated with atmospheric pressure. A multiple regression model explains 65% of the variability in growth rate by the ACRI and precipitation at the nearest meteorological station. There were, however, complexities in the relationship between growth and physical variables, including an apparent 1-year lag between physical forcing changes and biological response. Also, when the last 4 years of poor growth are excluded, there is a very strong negative correlation with ice cover on a pan-arctic scale. Our results suggest that bivalves, as sentinels of climate change on multi-decadal scales, are sensitive to environmental variations associated with large-scale changes in climate, but that the effects will be determined by changes in environmental parameters regulating marine production and food availability on a local scale.This research was supported in part by the Norwegian Research Council, NORDKLIMA Program (150356-S30 and 151815-S30 to MLC), the U.S. National Science Foundation Offices of Polar Programs (OPP-0138596, OPP-0222423 to WGA) and Ocean Sciences (OCE-0215905 to SRT), the BBVA Foundation in Madrid (to MG), and with funds from the Howard Hughes Medical Institute through Bates College

Potential Impact of Antiretroviral Chemoprophylaxis on HIV-1 Transmission in Resource-Limited Settings

Background. The potential impact of pre-exposure chemoprophylaxis (PrEP) an heterosexual transmission of HIV-1 infection in resource-limited settings is uncertain. Methodology/Principle Findings. A deterministic mathematical model was used to simulate the effects of antiretroval PreP on an HIV-1 epidemic in sub-Saharan Africa under different scenarios (optimistic neutral and pessimistic) both with and without sexual disinhibition. Sensitivity analyses were used to evaluate the effect of uncertainty in input parameters on model output and included calculation of partial rank correlations and standardized rank regressions. In the scenario without sexual disinhibition after PrEP initiation, key parameters influencing infections prevented were effectiveness of PrEP (partial rank correlation coefficient (PRCC) = 0.94), PrEP discontinuation rate (PRCC=-0.94), level of coverage (PRCC=0.92), and time to achieve target coverage (PRCC=-082). In the scenario with sexual disinhibition, PrEP effectiveness and the extent of sexual disinhibition had the greatest impact on prevention. An optimistic scenario of PrEP with 90% effectiveness and 75% coverage of the general population predicted a 74% decline in cumulative HIV-1 infections after 10 years, and a 28.8% decline with PrEP targeted to the highest risk groups (16% of the population). Even With a 100% increase in at-risk behavior from sexual disinhibition, a beneficial effect (23.4%-62.7% decrease in infections) was seen with 90% effective PrEP across a broad range of coverage (25%-75%). Similar disinhibition led to a rise in infections with lower effectiveness of PrEP (≤50%). Conclusions/Significance. Mathematical modeling supports the potential public health benefit of PrEP. Approximately 2.7 to 3.2 million new HIV-1 infections could be averaged in southern sub-Saharan Africa over 10 years by targeting PrEP (having 90% effectiveness) to those at highest behavioral risk and by preventing sexual disinhibition. This benefit could be lost, however, by sexual disinhibition and by high PrEP discontinuation, especially with lower PrEP effectiveness (≤:50%). © 2007 Abbas et al

Brazilian Consensus on Photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of nonmelanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection