Antiretroviral therapy awareness and risky sexual behaviors : evidence from Mozambique

This paper studies the effect of increased access to antiretroviral therapy on risky sexual behavior, using data collected in Mozambique in 2007 and 2008. The survey sampled both households of randomly selected HIV positive individuals and households from the general population. Controlling for unobserved individual characteristics, the findings support the hypothesis of disinhibition behaviors, whereby risky sexual behaviors increase in response to the perceived changes in risk associated with increased access to antiretroviral therapy. Furthermore, men and women respond differently to the perceived changes in risk. In particular, risky behaviors increase for men who believe, wrongly, that AIDS can be cured, while risky behaviors increase for women who believe, correctly, that antiretroviral therapy can treat AIDS but cannot cure it. The findings suggest that scaling up access to antiretroviral therapy without prevention programs may not be optimal if the objective is to contain the disease, since people would adjust their sexual behavior in response to the perceived changes in risk. Therefore, prevention programs need to include educational messages about antiretroviral therapy, and address the changing beliefs about HIV in the era of increasing antiretroviral therapy availability.Population Policies,HIV AIDS,Disease Control&Prevention,Gender and Health,Adolescent Health

Food crisis, household welfare and HIV/AIDS treatment : evidence from Mozambique

Using panel data from Mozambique collected in 2007 and 2008, the authors explore the impact of the food crisis on the welfare of households living with HIV/AIDS. The analysis finds that there has been a real deterioration of welfare in terms of income, food consumption, and nutritional status in Mozambique between 2007 and 2008, among both HIV and comparison households. However, HIV households have not suffered more from the crisis than others. Results on the evolution of labor force participation suggest that initiation of treatment and better services in health facilities have counter-balanced the effect of the crisis by improving the health of patients and their labor force participation. In addition, the authors look at the effect of the change in welfare on the frequency of visits to a health facility of patients and on their treatment outcomes. Both variables can proxy for adherence to treatment. This is a particularly crucial issue as it affects both the health of the patient and public health, because sub-optimal adherence leads to the development of resistant forms of the virus. The paper finds no effect of the change in welfare on the frequency of visits, but does find that people who experienced a negative income shock also experienced a reduction or a slower progression in treatment outcomes.Health Monitoring&Evaluation,Disease Control&Prevention,Food&Beverage Industry,Gender and Health,Food Security

Paradigms, possibilities and probabilities: Comment on Hinterecker et al. (2016)

Hinterecker et al. (2016) compared the adequacy of the probabilistic new paradigm in reasoning with the recent revision of mental models theory (MMT) for explaining a novel class of inferences containing the modal term “possibly”. For example, the door is closed or the window is open or both, therefore, possibly the door is closed and the window is open (A or B or both, therefore, possibly(A & B)). They concluded that their results support MMT. In this comment, it is argued that Hinterecker et al. (2016) have not adequately characterised the theory of probabilistic validity (p-validity) on which the new paradigm depends. It is unclear how p-validity can be applied to these inferences, which are anyway peripheral to the theory. It is also argued that the revision of MMT is not well motivated and its adoption leads to many logical absurdities. Moreover, the comparison is not appropriate because these theories are defined at different levels of computational explanation. In particular, revised MMT lacks a provably consistent computational level theory that could justify treating these inferences as valid. It is further argued that the data could result from the non-colloquial locutions used to express the premises. Finally, an alternative pragmatic account is proposed based on the idea that a conclusion is possible if what someone knows cannot rule it out. This account could be applied to the unrevised mental model theory rendering the revision redundant

Large-scale purification of factor VIII by affinity chromatography: optimization of process parameters

The optimization of a new process for the extraction of human coagulation factor VIII (FVIII) from plasma with the tailor-made affinity matrix dimethylaminopropylcarbamylpentyl-Sepharose CL-4B (C3---C5 matrix) is described. First, plasma is applied to DEAE-Sephadex A-50 anion exchanger in order to separate a number of proteins, including coagulation factors II, IX and X (prothrombin complex), from FVIII. Subsequently, the unbound fraction of the ion exchanger, containing FVIII, is contacted with the C3---C5 affinity matrix. Optimization of the FVIII affinity chromatographic procedure is accomplished in terms of the ligand density of the matrix, adsorption mode (batch-wise versus column-wise adsorption and matrix to plasma ratio), and conditions of pH and conductivity to be applied on washing and desorption. In scale-up experiments, by processing 20 1 of plasma, the recovery (340 U VIII:C/kg plasma) and the specific activity (s.a.) (1.2 U VIII:C/mg protein) are better than those obtained by cryoprecipitation (recovery 300 U VIII:C/kg plasma, s.a. O.3 U VIII:C/mg protein). The newly developed process using the specially designed C3---C5 affinity matrix has potential application in the process-scale purification of FVIII

The TREC2001 video track: information retrieval on digital video information

The development of techniques to support content-based access to archives of digital video information has recently started to receive much attention from the research community. During 2001, the annual TREC activity, which has been benchmarking the performance of information retrieval techniques on a range of media for 10 years, included a ”track“ or activity which allowed investigation into approaches to support searching through a video library. This paper is not intended to provide a comprehensive picture of the different approaches taken by the TREC2001 video track participants but instead we give an overview of the TREC video search task and a thumbnail sketch of the approaches taken by different groups. The reason for writing this paper is to highlight the message from the TREC video track that there are now a variety of approaches available for searching and browsing through digital video archives, that these approaches do work, are scalable to larger archives and can yield useful retrieval performance for users. This has important implications in making digital libraries of video information attainable

Oxygen adsorption on the Ru (10 bar 1 0) surface: Anomalous coverage dependence

Oxygen adsorption onto Ru (10 bar 1 0) results in the formation of two ordered overlayers, i.e. a c(2 times 4)-2O and a (2 times 1)pg-2O phase, which were analyzed by low-energy electron diffraction (LEED) and density functional theory (DFT) calculation. In addition, the vibrational properties of these overlayers were studied by high-resolution electron loss spectroscopy. In both phases, oxygen occupies the threefold coordinated hcp site along the densely packed rows on an otherwise unreconstructed surface, i.e. the O atoms are attached to two atoms in the first Ru layer Ru(1) and to one Ru atom in the second layer Ru(2), forming zigzag chains along the troughs. While in the low-coverage c(2 times 4)-O phase, the bond lengths of O to Ru(1) and Ru(2) are 2.08 A and 2.03 A, respectively, corresponding bond lengths in the high-coverage (2 times 1)-2O phase are 2.01 A and 2.04 A (LEED). Although the adsorption energy decreases by 220 meV with O coverage (DFT calculations), we observe experimentally a shortening of the Ru(1)-O bond length with O coverage. This effect could not be reconciled with the present DFT-GGA calculations. The nu(Ru-O) stretch mode is found at 67 meV [c(2 times 4)-2O] and 64 meV [(2 times 1)pg-2O].Comment: 10 pages, figures are available as hardcopies on request by mailing [email protected], submitted to Phys. Rev. B (8. Aug. 97), other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm

Antiretroviral therapy perceived efficacy and risky sexual behaviors: Evidence from Mozambique

This paper studies the effect of increased access to antiretroviral therapy (ART) for AIDS on self-reported risky sexual behavior, using data collected in Mozambique in 2007 and 2008. The survey sampled both households from randomly selected HIV positive individuals and comparison households from the general population. Controlling for unobserved individual characteristics, our findings support the hypothesis of disinhibition behaviors, in which people report more sexual risk taking when they perceive ART as more efficacious. In particular, risky behaviors are more positively associated with efficacious ART for family members of HIV positive persons and for individuals from comparison households. However, over the study period, we find that increased experience with ART at the nearest health facility has decreased, rather than increased, the perceived efficacy of ART. To the degree that the perceived efficacy of ART has declined, perhaps because people have known more patients who have failed treatment, people's sexual behavior has become more cautious. Our findings suggest that risk behavior is sensitive to the perceived efficacy of ART programs and that efforts to expand ART access or reduce ART failure rates must be supplemented with programs to prevent a resurgence of risky sexual behavior. We stress that our identification strategy reveals associations, and therefore our findings should not be interpreted as causal.Peer reviewedEconomic

Real Space Observations of Magnesium Hydride Formation and Decomposition

The mechanisms of magnesium hydride formation and thermal decomposition are directly examined using in-situ imaging.Comment: 3 pages, 4 figure

Ab-initio density functional study of O on the Ag(001) surface

The adsorption of oxygen on the Ag(001) is investigated by means of density functional techniques. Starting from a characterization of the clean silver surfaces oxygen adsorption in several modifications (molecularly, on-surface, sub-surface, Ag$_2$O) for varying coverage was studied. Besides structural parameters and adsorption energies also work-function changes, vibrational frequencies and core level energies were calculated for a better characterization of the adsorption structures and an easier comparison to the rich experimental data.Comment: 26 pages, 8 figures, Surf. Sci. accepte