Scaling a waterfall: a meta-ethnography of adolescent progression through the stages of HIV care in sub-Saharan Africa.

INTRODUCTION: Observational studies have shown considerable attrition among adolescents living with HIV across the "cascade" of HIV care in sub-Saharan Africa, leading to higher mortality rates compared to HIV-infected adults or children. We synthesized evidence from qualitative studies on factors that promote or undermine engagement with HIV services among adolescents living with HIV in sub-Saharan Africa. METHODS: We systematically searched five databases for studies published between 2005 and 2016 that met pre-defined inclusion criteria. We used a meta-ethnographic approach to identify first, second and third order constructs from eligible studies, and applied a socio-ecological framework to situate our results across different levels of influence, and in relation to each stage of the HIV cascade. RESULTS AND DISCUSSION: We identified 3089 citations, of which 24 articles were eligible for inclusion. Of these, 17 were from Southern Africa while 11 were from Eastern Africa. 6 explored issues related to HIV testing, 11 explored treatment adherence, and 7 covered multiple stages of the cascade. Twelve third-order constructs emerged to explain adolescents' engagement in HIV care. Stigma was the most salient factor impeding adolescents' interactions with HIV care over the past decade. Self-efficacy to adapt to life with HIV and support from family or social networks were critical enablers supporting uptake and retention in HIV care and treatment programmes. Provision of adolescent-friendly services and health systems issues, such as the availability of efficient, confidential and comfortable services, were also reported to drive sustained care engagement. Individual-level factors, including past illness experiences, identifying mechanisms to manage pill-taking in social situations, financial (in)stability and the presence/absence of future aspirations also shaped adolescents HIV care engagement. CONCLUSIONS: Adolescents' initial and ongoing use of HIV care was frequently undermined by individual-level issues; although family, community and health systems factors played important roles. Interventions should prioritise addressing psychosocial issues among adolescents to promote individual-level engagement with HIV care, and ultimately reduce mortality. Further research should explore issues relating to care linkage and ART initiation in different settings, particularly as "test and treat" policies are scaled up

Reducing Validity in Epistemic ATL to Validity in Epistemic CTL

We propose a validity preserving translation from a subset of epistemic Alternating-time Temporal Logic (ATL) to epistemic Computation Tree Logic (CTL). The considered subset of epistemic ATL is known to have the finite model property and decidable model-checking. This entails the decidability of validity but the implied algorithm is unfeasible. Reducing the validity problem to that in a corresponding system of CTL makes the techniques for automated deduction for that logic available for the handling of the apparently more complex system of ATL.Comment: In Proceedings SR 2013, arXiv:1303.007

Relational visual cluster validity

The assessment of cluster validity plays a very important role in cluster analysis. Most commonly used cluster validity methods are based on statistical hypothesis testing or finding the best clustering scheme by computing a number of different cluster validity indices. A number of visual methods of cluster validity have been produced to display directly the validity of clusters by mapping data into two- or three-dimensional space. However, these methods may lose too much information to correctly estimate the results of clustering algorithms. Although the visual cluster validity (VCV) method of Hathaway and Bezdek can successfully solve this problem, it can only be applied for object data, i.e. feature measurements. There are very few validity methods that can be used to analyze the validity of data where only a similarity or dissimilarity relation exists – relational data. To tackle this problem, this paper presents a relational visual cluster validity (RVCV) method to assess the validity of clustering relational data. This is done by combining the results of the non-Euclidean relational fuzzy c-means (NERFCM) algorithm with a modification of the VCV method to produce a visual representation of cluster validity. RVCV can cluster complete and incomplete relational data and adds to the visual cluster validity theory. Numeric examples using synthetic and real data are presente

Improving Students’ Creativity In The Proving The Validity Of Arguments Through Learning Strategy ”What’s Another Way”

The purpose of this study was to describe the enhancing creativity of students in proving the validity of arguments through learning strategy "what's another way". This research was an action research with qualitative descriptive approach. The subjects were students of mathematics education UNIROW Tuban. The study was conducted in three cycles, Cycle I: Proof of Validity Arguments Directly, Cycle II: Proof of Validity Arguments Indirectly, and Cycle III: Validity Evidence Arguments Containing Kuantor. This research results in the following: In general, the learning strategy "what's another way" to improve the creativity of students in proving the validity of the argument. The main difficulty in proving the validity of the argument is as follows: a) the use of evidentiary rules of argument, and b) the idea of proof plan. Key Words: creativity, proving, argument, validity, and ”what’s another way

Validity of the Adiabatic Approximation

We analyze the validity of the adiabatic approximation, and in particular the reliability of what has been called the "standard criterion" for validity of this approximation. Recently, this criterion has been found to be insufficient. We will argue that the criterion is sufficient only when it agrees with the intuitive notion of slowness of evolution of the Hamiltonian. However, it can be insufficient in cases where the Hamiltonian varies rapidly but only by a small amount. We also emphasize the distinction between the adiabatic {\em theorem} and the adiabatic {\em approximation}, two quite different although closely related ideas.Comment: 4 pages, 1 figur

Validity, dialetheism and self-reference

It has been argued recently (Beall in Spandrels of truth, Oxford University Press, Oxford, 2009; Beall and Murzi J Philos 110:143–165, 2013) that dialetheist theories are unable to express the concept of naive validity. In this paper, we will show that (Formula presented.) can be non-trivially expanded with a naive validity predicate. The resulting theory, (Formula presented.) reaches this goal by adopting a weak self-referential procedure. We show that (Formula presented.) is sound and complete with respect to the three-sided sequent calculus (Formula presented.). Moreover, (Formula presented.) can be safely expanded with a transparent truth predicate. We will also present an alternative theory (Formula presented.), which includes a non-deterministic validity predicate.Fil: Pailos, Federico Matias. Instituto de Investigaciones Filosóficas - Sadaf; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

External validity of randomized controlled trials on Alzheimer's disease: the biases of frailty and biological aging

To date, the external validity of randomized controlled trials (RCTs) on Alzheimer's disease (AD) has been assessed only considering monodimensional variables. Nevertheless, looking at isolated and single characteristics cannot guarantee a sufficient level of appreciation of the AD patients' complexity. The only way to understand whether the two worlds (i.e., research and clinics) deal with the same type of patients is to adopt multidimensional approaches more holistically reflecting the biological age of the individual. In the present study, we compared measures of frailty/biological aging [assessed by a Frailty Index (FI)] of a sample of patients with AD resulted eligible and subsequently included in phase III RCTs compared to patients referring to the same clinical service, but not considered for inclusion. The "RCT sample" and the "real world sample" were found to be statistically similar for all the considered sociodemographic and clinical variables. Nevertheless, the "real world sample" was found to be significantly frailer compared to the "RCT sample," as indicated by higher FI scores [0.28 (SD 0.1) vs. 0.17 (SD 0.1);p < 0.001, respectively]. Moreover, when assessing the relationship between FI and age, we found that the correlation was almost null in the "RCT sample" (Spearman'sr = 0.01;p = 0.98), while it was statistically significant in the "real world sample" (r = 0.49;p = 0.02). The application of too rigid designs may result in the poor representativeness of RCT samples. It may even imply the study of a condition biologically different from that observed in the "real world." The adoption of multidimensional measures capable to capture the individual's biological age may facilitate evaluating the external validity of clinical studies, implicitly improving the interpretation of the results and their translation in the clinical arena

Cue validity and object-based attention

In a previous study, Egly, Driver, and Rafal (1994) observed both space- and object-based components of visual selective attention. However, the mechanisms underlying these two components and the relationship between them are not well understood. In the present research, with a similar paradigm, these issues were addressed by manipulating cue validity. Behavioral results indicated the presence of both space- and object-based components under high cue validity, similar to the results of Egly et al.'s study. In addition, under low cue validity, the space-based component was absent, whereas the object-based component was maintained. Further event-related potential results demonstrated an object-based effect at a sensory level over the posterior areas of brain, and a space-based effect over the anterior region. The present data suggest that the space- and object-based components reflect mainly voluntary and reflexive mechanisms, respectively