1,515 research outputs found
Long-Term Antiretroviral Treatment Adherence in HIV-Infected Adolescents and Adults in Uganda: A Qualitative Study
Background
Long-term success of HIV antiretroviral therapy requires near-perfect adherence, maintained throughout one’s lifetime. However, perceptions towards ART and patterns of adherence may change during the life course. We assessed challenges to long-term adherence in adolescents and adults in three regional HIV treatment centers in Uganda.
Methods
We conducted 24 in-depth interviews and 2 focus group discussions with a total of 33 health-care providers and expert clients (HIV patients on long-term ART who assist with adherence support of fellow patients). Interview topics included experiences with patients on long-term treatment with either declining adherence or persistent poor adherence. Transcribed texts were coded and analyzed based on the social-ecological framework highlighting differences and commonalities between adolescents and adults.
Results
The overarching themes in adolescents were unstructured treatment holidays, delays in disclosure of HIV status by caretakers, stigma, which was mainly experienced in boarding schools, and diminishing or lack of clinical support. In particular, there was minimal support for early and gradual disclosure for caretakers to the infected children, diminishing clinical support for young adults during transition to adult-based care and declining peer-to-peer support group activities. The predominating theme in adults was challenges with treatment access among temporary economic migrants. Common themes to adults and adolescents were challenges with disclosure in intimate relationships, treatment related factors including side effects, supply of single tablets in place of fixed-dose combined drugs, supply of drug brands with unfavorable taste and missed opportunities for counseling due to shortage of staff.
Conclusion
Adherence counseling and support should be adapted differently for adolescents and adults and to the emerging life course challenges in long-term treated patients. Programs should also address constraints experienced by temporary economic migrants to ensure continuity of treatment within the host country
The role of antiphase boundaries during ion sputtering and solid phase epitaxy of Si(001)
The Si(001) surface morphology during ion sputtering at elevated temperatures
and solid phase epitaxy following ion sputtering at room temperature has been
investigated using scanning tunneling microscopy. Two types of antiphase
boundaries form on Si(001) surfaces during ion sputtering and solid phase
epitaxy. One type of antiphase boundary, the AP2 antiphase boundary,
contributes to the surface roughening. AP2 antiphase boundaries are stable up
to 973K, and ion sputtering and solid phase epitaxy performed at 973K result in
atomically flat Si(001) surfaces.Comment: 16 pages, 4 figures, to be published in Surface Scienc
Investigation of Single Boron Acceptors at the Cleaved Si:B (111) Surface
The cleaved and (2 x 1) reconstructed (111) surface of p-type Si is
investigated by scanning tunneling microscopy (STM). Single B acceptors are
identified due to their characteristic voltage-dependent contrast which is
explained by a local energetic shift of the electronic density of states caused
by the Coulomb potential of the negatively charged acceptor. In addition,
detailed analysis of the STM images shows that apparently one orbital is
missing at the B site at sample voltages of 0.4 - 0.6 V, corresponding to the
absence of a localized dangling-bond state. Scanning tunneling spectroscopy
confirms a strongly altered density of states at the B atom due to the
different electronic structure of B compared to Si.Comment: 6 pages, 7 figure
Allowing Visitors Back in the Nursing Home During the COVID-19 Crisis:A Dutch National Study Into First Experiences and Impact on Well-Being
Objectives: To prevent and control COVID-19 infections, nursing homes across the world have taken very restrictive measures, including a ban for visitors. These restrictive measures have an enormous impact on residents' well-being and pose dilemmas for staff, although primary data are lacking. A Dutch guideline was developed to cautiously open nursing homes for visitors during the COVID-19 pandemic. This study reports the first findings on how the guideline was applied in the local context; the compliance to local protocols; and the impact on well-being of residents, their family caregivers, and staff.Design: A mixed-methods cross-sectional study was conducted.Setting and Participants: In total, 26 nursing homes were permitted to enlarge their possibilities for allowing visitors in their facility. These nursing homes were proportionally representative of the Netherlands as they were selected by their local Area Health Authority for participation. At each nursing home, a contact person was selected for participation in the current study.Methods: A mixed-methods cross-sectional study was conducted, consisting of questionnaire, telephone interviews, analyses of documentation (ie, local visiting protocols), and a WhatsApp group.Results: Variation in local protocols was observed, for example, related to the use of personal protective equipment, location, and supervision of visits. In general, experiences were very positive. All nursing homes recognized the added value of real and personal contact between residents and their loved ones and indicated a positive impact on well-being. Compliance with local guidelines was sufficient to good. No new COVID-19 infections were reported during this time.Conclusions and Implications: These results indicate the value of family visitation in nursing homes and positive impact of visits. Based on these results, the Dutch government has decided to allow all nursing homes in the Netherlands to cautiously open their homes using the guidelines. More research is needed on impact and long-term compliance. (C) 2020 AMDA - The Society for Post-Acute and Long-Term Care Medicine.</p
The role of electronic correlation in the Si(100) reconstruction: a quantum Monte Carlo study
Recent low-temperature scanning tunneling experiments have challenged the
generally accepted picture of buckled silicon dimers as the ground state
reconstruction of the Si(100) surface. Together with the symmetric dimer model
of the surface suggested by quantum chemistry calculations on small clusters,
these findings question our general understanding of electronic correlations at
surfaces and its proper description within density functional theory. We
present quantum Monte Carlo calculations on large cluster models of the
symmetric and buckled surface, and conclude that buckling remains energetically
more favorable even when the present-day best treatment of electronic
correlation is employed.Comment: 5 pages, Revtex, 10 figure
Randomised, double-blind, placebo-controlled clinical trial investigating the effects of inorganic nitrate in hypertension-induced target organ damage: protocol of the NITRATE-TOD study in the UK
© 2020 Author(s). Introduction: Arterial stiffness and left ventricular (LV) hypertrophy are the key markers of hypertensive target organ damage (TOD) associated with increased cardiovascular morbidity and mortality. We have previously shown that dietary inorganic nitrate supplementation lowers blood pressure (BP) in hypertension, however, whether this approach might also improve markers of hypertensive TOD is unknown. In this study, we will investigate whether daily dietary inorganic nitrate administration reduces LV mass and improves measures of arterial stiffness. Methods and design: NITRATE-TOD is a double-blind, randomised, single-centre, placebo-controlled phase II trial aiming to enrol 160 patients with suboptimal BP control on one or more antihypertensives. Patients will be randomised to receive 4 months once daily dose of either nitrate-rich beetroot juice or nitrate-deplete beetroot juice (placebo). The primary outcomes are reduction in LV mass and reduction in pulse wave velocity (PWV) and central BP. The study has a power of 95% for detecting a 9 g LV mass change by cardiovascular MRI (∼6% change for a mildly hypertrophied heart of 150 g). For PWV, we have a power of >95% for detecting a 0.6 m/s absolute change. For central systolic BP, we have a>90% power to detect a 5.8 mm Hg difference in central systolic BP. Secondary end points include change in ultrasound flow-mediated dilation, change in plasma nitrate and nitrite concentration and change in BP. Ethics and dissemination: The study was approved by the London - City and East Research Ethics Committee (10/H0703/98). Trial results will be published according to the Consolidated Standards of Reporting Trials statement and will be presented at conferences and reported in peer-reviewed journals
Efficiently computing the Shapley value of connectivity games in low-treewidth graphs
The Shapley value is the solution concept in cooperative game theory that is most used in both theoretical and practical settings. Unfortunately, in general, computing the Shapley value is computationally intractable. This paper focuses on computing the Shapley value of (weighted) connectivity games. For these connectivity games, which are defined on an underlying (weighted) graph, computing the Shapley value is #P-hard, and thus (likely) intractable even for graphs with a moderate number of vertices. We present an algorithm that can efficiently compute the Shapley value if the underlying graph has bounded treewidth. Next, we apply our algorithm to several real-world (covert) networks. We show that our algorithm can quickly compute exact Shapley values for these networks, whereas in prior work these values could only be approximated using a heuristic method. Finally, it is demonstrated that our algorithm can also efficiently compute the Shapley value time for several larger (artificial) benchmark graphs from the PACE 2018 challenge
Proportionate flow shop games
htmlabstractIn a proportionate flow shop problem several jobs have to be processed through a fixed sequence of machines and the processing time of each job is equal on all machines. By identifying jobs with agents, whose costs linearly depend on the completion time of their jobs, and assuming an initial processing order on the jobs, we face two problems: the first one is how to obtain an optimal order that minimizes the total processing cost, the second one is how to allocate the cost savings obtained by ordering the jobs optimally. In this paper we focus on the allocation problem. PFS games are defined as cooperative games associated to proportionate flow shop problems. It is seen that PFS games have a nonempty core. Moreover, it is shown that PFS games are convex if the jobs are initially ordered in decreasing urgency. For this case an explicit game independent expression for the Shapley value is provid
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