3,599 research outputs found
Washing away Ebola : environmental stress, rumor, and ethnomedical response in a deadly epidemic
Summary
Emerging infectious diseases are a critical issue in contemporary global environmental health. The 2014/15 Ebola epidemic in West Africa has become the large most widespread outbreak of the disease to date, Among its various impacts, the epidemic triggered a proliferation of emergent ethnomedical cultural responses. With the appearance of cases in Nigeria, information about these practices quickly spread through social media and other communication channels into neighboring Cameroon as people attempted to assuage their uncertainty and significant fear of the disease. We assess this process of information-sharing about ethnomedical practices like salt-water baths and drinking as an Ebola preventive in light of theories on the spread of rumors. Rumors are mechanisms groups use to help order their experience of reality during times of environmental uncertainty and growing confusion; however, rumors can also impact public attitudes and behaviors in ways that expose individuals to greater risk. Based on data collected from 90 interviews with participants in two cities in Cameroon, we demonstrate that information on the prophylactic use of salt-water baths and drinking spread quickly and widely. This case affirms that people do not remain passive during times of an environmental emergency and that work in environmental health must pay heed to processes of rumor formation, spread, and impact.
Keywords:
Ebola; social stress;rumor; epidemics; ethnomedicin
Interaction of silver nanoparticles with HIV-1
The interaction of nanoparticles with biomolecules and microorganisms is an expanding field of research. Within this field, an area that has been largely unexplored is the interaction of metal nanoparticles with viruses. In this work, we demonstrate that silver nanoparticles undergo a size-dependent interaction with HIV-1, with nanoparticles exclusively in the range of 1–10 nm attached to the virus. The regular spatial arrangement of the attached nanoparticles, the center-to-center distance between nanoparticles, and the fact that the exposed sulfur-bearing residues of the glycoprotein knobs would be attractive sites for nanoparticle interaction suggest that silver nanoparticles interact with the HIV-1 virus via preferential binding to the gp120 glycoprotein knobs. Due to this interaction, silver nanoparticles inhibit the virus from binding to host cells, as demonstrated in vitro
Metabolic Reprogramming of Cystic Fibrosis Macrophages through the Unfolded Protein Response
Cystic fibrosis (CF) is a life-threatening autosomal genetic disease, which affects approximately 48,204 individuals in Europe and 29,887 in the USA. This condition is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). In CF, the mutated CFTR, in the case of DF508, causes accumulation of misfolded proteins leading to endoplasmic reticulum (ER) stress, with activation of the IRE1a-XBP1 pathway. This pathway is essential in the regulation of a subset of genes controlling proinflammatory and metabolic responses in immune cells; nevertheless, the metabolic rates of immune cells and the role of this pathway in CF remain elusive. In this study, it was shown that innate immune cells from patients with CF show significantly higher levels of ER stress, particularly in the IRE1a-XBP1 signalling pathway. Interestingly, ER stress was only present in neutrophils, monocytes and macrophages from patients with CF. Overactivation of the IRE1a-XBP1 signalling pathway rewires M1 macrophages from patients with CF, and increases macrophages’ metabolic rates, with high glycolytic rates and mitochondrial function. The increased activity of the IRE1a-XBP1 signalling pathway and the increased metabolic rates were associated with excessive production of TNF and IL-6. Specific inhibition of the RNase domain of the IRE1 arm decreased the excessive glycolytic rates, mitochondrial function and production of inflammatory cytokines. Furthermore, Orkambi, Symkevi and Ivacaftor had an essential impact in changing the metabolic profile of cells with CF mutations. This study shows how innate immune cells from CF patients are affected by ER stress, in particular, M1 macrophages. Moreover, the IRE1a-XBP1 signalling pathway is essential for the increased metabolic rates seen in M1 macrophages with CF mutations. Modulation of ER stress might be an exciting option to recover the metabolic fitness of cells with CF mutation
Women’s Leadership in Humanitarian Settings in Central America
During the first-ever World Humanitarian Summit last year, the global humanitarian community was abuzz around Local Humanitarian Leadership (LHL). Concrete commitments were made and reflected in the Grand Bargain as well as in the Charter for Change, proposing initial steps at the global level for a shift in power, knowledge and resources towards local humanitarian actors. There has never been a more appropriate time to look at women’s leadership in the humanitarian sector, particularly at the local level, as women’s leadership is also about transforming power structures and systems.We interviewed nine women leaders from Guatemala, El Salvador, Honduras and Nicaragua, from civil society organizations members of the CRGR, feminists, academics, and humanitarian managers who have successfully led emergency response teams. Through interviews with these nine highly experienced leaders, we identified the daily challenges they face in the course of their work, and how humanitarian trainings could better cater to their leadership development needs. By highlighting the perspectives of these few women leaders in Central America, we wish to develop guidance on how women’s leadership can be made more visible in humanitarian workshops and training materials, and how to make the challenges women leaders face in the humanitarian sector better understood. Despite the small number of interviews and the qualitative nature of this report, the findings may also offer insights for learning in other areas of the globe, such as Asia
The strong gravitational field regime of compact objects beyond General Relativity
The maturity of experimental probes of the strong field regime of gravity, both in terms of sensitivity and number of observations, offers hope in discriminating General Relativity (GR) from alternative theories of gravity in the near future. At present, such probes include gravitational-wave observations with ground-based interferometers, 1.3 mm electromagnetic observations with Very-Large-Baseline Interferometry (VLBI) and binary pulsar observations. For these, a prominent role is played by compact objects, which source strong (and in some cases highly dynamical) gravitational fields, and therefore make up the main target of such observations. Most efforts so far have focused on computing strong field predictions for compact objects in GR. However, if one aims to fairly discriminate among them, the same predictions need to be obtained for theories beyond GR.
The purpose of this Thesis is to explore various aspects of compact objects in theories beyond GR where strong gravitational fields are relevant.
We begin by studying k-essence, a scalar-tensor theory motivated as a viable dynamical explanation for Dark Energy. Derivative self-interactions provide (through a kinetic screening mechanism) the suppression of the extra scalar force needed to satisfy local gravitational constraints. We first explore ways to ensure that the theory admits a well-posed initial-value problem, a mathematical property that is essential for obtaining predictions in the strong field with numerical relativity. We then show how some of the lessons learned for k-essence can also be applied to self-interacting massive vector theories. In addition, we explore the resilience of kinetic screening with different possibilities in which the scalar can couple to the matter sector.
We then turn our attention to the question of whether gravity can be constrained with black hole images from VLBI, and whether this can be done in spite of uncertainties in the astrophysical modelling of the system. We present a proof-of-principle demonstration of a theory-agnostic framework to reconstruct simultaneously both the underlying geometry and accretion behind these images. Our framework makes use of a general parametrization for these properties and of a Principal Component Analysis to mitigate the degeneracies linked to the presence of a large number of parameters.
Finally, we consider the question of whether quantum gravity can provide a resolution to the issue of singularities inside black holes. We do so in the context of (2+1) projectable Hořava gravity, a Lorentz-violating quantum gravity candidate that has been shown to be renormalizable (beyond power counting) and ultraviolet complete. We obtain all circularly-symmetric stationary solutions and show that, in spite of naive expectations, solutions that reduce to BHs at low energies remain singular in the interior
Effects of exercise modalities on arterial stiffness and wave reflection: a systematic review and meta-analysis of randomized controlled trials
Background and Objectives:
Physical activity is associated with lower cardiovascular and all-cause mortality. However, the effects of different exercise modalities on arterial stiffness are currently unclear. Our objectives were to investigate the effects of exercise modalities (aerobic, resistance or combined) on pulse wave velocity (PWV) and augmentation index (AIx), and to determine whether the effects on these indices differed according to the participants' or exercise characteristics.
Methods:
We searched the Medline, Embase and Cochrane Library databases from inception until April 2014 for randomized controlled trials lasting ≥4 weeks investigating the effects of exercise modalities on PWV and AIx in adults aged ≥18 years.
Results:
Forty-two studies (1627 participants) were included in this analysis. Aerobic exercise improved both PWV (WMD: −0.63 m/s, 95% CI: −0.90, −0.35) and AIx (WMD:−2.63%, 95% CI: −5.25 to −0.02) significantly. Aerobic exercise training showed significantly greater reduction in brachial-ankle (WMD: −1.01 m/s, 95% CI: −1.57, −0.44) than in carotid-femoral (WMD: -0.39 m/s, 95% CI: −0.52, −0.27) PWV. Higher aerobic exercise intensity was associated with larger reductions in AIx (β: −1.55%, CI −3.09, 0.0001). In addition, aerobic exercise had a significantly larger effect in reducing PWV (WMD:−1.0 m/s, 95% CI: −1.43, −0.57) in participants with stiffer arteries (PWV ≥8 m/s). Resistance exercise had no effect on PWV and AIx. There was no significant effect of combined exercise on PWV and AIx.
Conclusions:
We conclude that aerobic exercise improved arterial stiffness significantly and that the effect was enhanced with higher aerobic exercise intensity and in participants with greater arterial stiffness at baseline.
Trial Registration PROSPERO:
Database registration: CRD42014009744,
- …