2,393 research outputs found
Critical minerals and energy-impacts and limitations of moving to unconventional resources
© 2016 by the authors. The nexus of minerals and energy becomes ever more important as the economic growth and development of countries in the global South accelerates and the needs of new energy technologies expand, while at the same time various important minerals are declining in grade and available reserves from conventional mining. Unconventional resources in the form of deep ocean deposits and urban ores are being widely examined, although exploitation is still limited. This paper examines some of the implications of the transition towards cleaner energy futures in parallel with the shifts through conventional ore decline and the uptake of unconventional mineral resources. Three energy scenarios, each with three levels of uptake of renewable energy, are assessed for the potential of critical minerals to restrict growth under 12 alternative mineral supply patterns. Under steady material intensities per unit of capacity, the study indicates that selenium, indium and tellurium could be barriers in the expansion of thin-film photovoltaics, while neodymium and dysprosium may delay the propagation of wind power. For fuel cells, no restrictions are observed
Bringing social context into global biomedical HIV cure-related research: An urgent call to action
Advances in science have ushered in a wave of new potential curative and control strategies for HIV that could eliminate the current requirement for life-long antiretroviral therapy (ART) for people living with HIV (PLWH). In this article, we argue that it is critical to consider social contexts in the development of HIV cure trial protocols. The biological and behavioral risk factors for HIV acquisition by study participants are inseparable from the social context in which these participants live. The article discusses an example of a cohort established to further HIV cure research that included social context, called the FRESH Acute HIV study, which combines a sociostructural intervention while conducting HIV prevention, treatment and cure-related research in Durban, South Africa. We make an urgent call to action to include sociobehavioral components as instrumental in future HIV cure trials in global context
Cardiac cellularity is dependent upon biological sex and is regulated by gonadal hormones.
AIMS: Sex differences have been consistently identified in cardiac physiology and incidence of cardiac disease. However, the underlying biological causes for the differences remain unclear. We sought to characterize the cardiac non-myocyte cellular landscape in female and male hearts to determine whether cellular proportion of the heart is sex-dependent and whether endocrine factors modulate the cardiac cell proportions.
METHODS AND RESULTS: Utilizing high-dimensional flow cytometry and immunofluorescence imaging, we found significant sex-specific differences in cellular composition of the heart in adult and juvenile mice, that develops postnatally. Removal of systemic gonadal hormones by gonadectomy results in rapid sex-specific changes in cardiac non-myocyte cellular proportions including alteration in resident mesenchymal cell and leucocyte populations, indicating gonadal hormones and their downstream targets regulate cardiac cellular composition. The ectopic reintroduction of oestrogen and testosterone to female and male mice, respectively, reverses many of these gonadectomy-induced compositional changes.
CONCLUSION: This work shows that the constituent cell types of the mouse heart are hormone-dependent and that the cardiac cellular landscapes are distinct in females and males, remain plastic, and can be rapidly modulated by endocrine factors. These observations have implications for strategies aiming to therapeutically alter cardiac cellular heterogeneity and underscore the importance of considering biological sex for studies examining cardiac physiology and stress responses
A Study to Validate a Self-Reported Version of the ONS Drug Dependence Questionnaire
Aim: A prospective study to establish the reliability of a self-completion version of the Office for National Statistics (ONS) questionnaire for assessing drug dependence of substance misuse clients. Method: A total of 47 treatment seeking opioid-dependent clients completed the self-complete version of the ONS questionnaire (ONS-sc) followed by the interviewer-administered ONS questionnaire (ONS-ia) at a single clinic appointment. Scores for four Class A drugs (heroin, methadone, speed and crack/cocaine) from both formats were compared. Results: The observed agreement was 87% or more and Cohen's kappa was 0.7 (p < 0.001) or more for all four Class A drugs. Sensitivity for each Class A drugs was 56% or higher and specificity was 87% or higher. Sensitivity for severe heroin dependency was 98% (CI 89–100%). There was a 100% correlation between the ONS-sc and positive urine analysis for heroin use. However, methadone and crack/cocaine drug use appeared under reported. Conclusion: ONS-sc is a feasible, practical and time-saving alternative to a detailed interview on drug dependence. Further research with a larger sample size and non-opiate-dependent clients are needed, as this could prove a useful tool for monitoring clients in everyday practice, or for survey purposes where interviews are impractical
Superradiant atomic recoil lasing with orbital-angular-momentum light
We analyze the collective light scattering by cold atoms in free space of a pump-laser beam possessing orbital angular momentum. We derive a set of coupled multiparticle equations for the atomic motion in which the vacuum-mode field is adiabatically eliminated. The resulting equations describe collective recoil as due to either transfer of linear momentum or orbital angular momentum. For a transverse annular atomic distribution the initial equilibrium with uniform atomic phases and no scattered field is unstable. The atoms are set in rotation and bunched in phase at different harmonics depending on the pump azimuthal index Formula Presented and on the ring radius
Capture the fracture: a best practice framework and global campaign to break the fragility fracture cycle
Summary
The International Osteoporosis Foundation (IOF) Capture the Fracture Campaign aims to support implementation of Fracture Liaison Services (FLS) throughout the world.
Introduction
FLS have been shown to close the ubiquitous secondary fracture prevention care gap, ensuring that fragility fracture sufferers receive appropriate assessment and intervention to reduce future fracture risk.
Methods
Capture the Fracture has developed internationally endorsed standards for best practice, will facilitate change at the national level to drive adoption of FLS and increase awareness of the challenges and opportunities presented by secondary fracture prevention to key stakeholders. The Best Practice Framework (BPF) sets an international benchmark for FLS, which defines essential and aspirational elements of service delivery.
Results
The BPF has been reviewed by leading experts from many countries and subject to beta-testing to ensure that it is internationally relevant and fit-for-purpose. The BPF will also serve as a measurement tool for IOF to award ‘Capture the Fracture Best Practice Recognition’ to celebrate successful FLS worldwide and drive service development in areas of unmet need. The Capture the Fracture website will provide a suite of resources related to FLS and secondary fracture prevention, which will be updated as new materials become available. A mentoring programme will enable those in the early stages of development of FLS to learn from colleagues elsewhere that have achieved Best Practice Recognition. A grant programme is in development to aid clinical systems which require financial assistance to establish FLS in their localities.
Conclusion
Nearly half a billion people will reach retirement age during the next 20 years. IOF has developed Capture the Fracture because this is the single most important thing that can be done to directly improve patient care, of both women and men, and reduce the spiralling fracture-related care costs worldwide.</p
Spectral reflectance of whale skin above the sea surface: a proposed measurement protocol
Great whales have been detected using very‐high‐resolution satellite imagery, suggesting this technology could be used to monitor whales in remote areas. However, the application of this method to whale studies is at an early developmental stage and several technical factors need to be addressed, including capacity for species differentiation and the maximum depth of detection in the water column. Both require knowledge of the spectral reflectance of the various whale species just above the sea surface, as when whales bodies break the surface of the water to breath, log or breach, there is, at times, no sea water between the whale's skin and the satellite sensor. Here we tested whether such reflectance could be measured on dead whale tissue. We measured the spectral reflectance of fresh integument collected during the bowhead subsistence harvest, and of thawed integument samples from various species obtained following strandings and stored at −20°C. We show that fresh and thawed samples of whale integument have different spectral properties. The reflectance of fresh samples was higher than the reflectance of thawed samples, as integument appears to darken after death and with time, even under frozen conditions. In this study, we present the first whale reflectance estimates (without the influence of sea water and for dead tissue). These provide a baseline for additional work, needed to advance the use of satellite imagery to monitor whales and facilitate their conservation
A major genetic locus in <i>Trypanosoma brucei</i> is a determinant of host pathology
The progression and variation of pathology during infections can be due to components from both host or pathogen, and/or the interaction between them. The influence of host genetic variation on disease pathology during infections with trypanosomes has been well studied in recent years, but the role of parasite genetic variation has not been extensively studied. We have shown that there is parasite strain-specific variation in the level of splenomegaly and hepatomegaly in infected mice and used a forward genetic approach to identify the parasite loci that determine this variation. This approach allowed us to dissect and identify the parasite loci that determine the complex phenotypes induced by infection. Using the available trypanosome genetic map, a major quantitative trait locus (QTL) was identified on T. brucei chromosome 3 (LOD = 7.2) that accounted for approximately two thirds of the variance observed in each of two correlated phenotypes, splenomegaly and hepatomegaly, in the infected mice (named <i>TbOrg1</i>). In addition, a second locus was identified that contributed to splenomegaly, hepatomegaly and reticulocytosis (<i>TbOrg2</i>). This is the first use of quantitative trait locus mapping in a diploid protozoan and shows that there are trypanosome genes that directly contribute to the progression of pathology during infections and, therefore, that parasite genetic variation can be a critical factor in disease outcome. The identification of parasite loci is a first step towards identifying the genes that are responsible for these important traits and shows the power of genetic analysis as a tool for dissecting complex quantitative phenotypic traits
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