190 research outputs found
Spectral Graph Transformer Networks for Brain Surface Parcellation
The analysis of the brain surface modeled as a graph mesh is a challenging
task. Conventional deep learning approaches often rely on data lying in the
Euclidean space. As an extension to irregular graphs, convolution operations
are defined in the Fourier or spectral domain. This spectral domain is obtained
by decomposing the graph Laplacian, which captures relevant shape information.
However, the spectral decomposition across different brain graphs causes
inconsistencies between the eigenvectors of individual spectral domains,
causing the graph learning algorithm to fail. Current spectral graph
convolution methods handle this variance by separately aligning the
eigenvectors to a reference brain in a slow iterative step. This paper presents
a novel approach for learning the transformation matrix required for aligning
brain meshes using a direct data-driven approach. Our alignment and graph
processing method provides a fast analysis of brain surfaces. The novel
Spectral Graph Transformer (SGT) network proposed in this paper uses very few
randomly sub-sampled nodes in the spectral domain to learn the alignment matrix
for multiple brain surfaces. We validate the use of this SGT network along with
a graph convolution network to perform cortical parcellation. Our method on 101
manually-labeled brain surfaces shows improved parcellation performance over a
no-alignment strategy, gaining a significant speed (1400 fold) over traditional
iterative alignment approaches.Comment: Equal contribution of R. He and K. Gopinat
Universal cures for idiosyncratic illnesses: a genealogy of therapeutic reasoning in the mental health field
Over the past decades, there has been a significant increase in prescriptions of psychotropic drugs for mental disorders. So far, most of the explanations of the phenomenon have focused on the process of medicalization, but little attention has been cast towards physicians' day-to-day clinical reasoning, and the way it affects therapeutic decision-making. This article addresses the complex relationship between aetiology, diagnosis and drug treatment by examining the style of reasoning underlying prescribing practices through an historical lens. A genealogy of contemporary prescribing practices is proposed, that draws significant comparisons between 19th-century medicine and modern psychiatry. Tensions between specific, standardized cures and specific, idiosyncratic patients have been historically at play in clinical reasoning - and still are today. This inquiry into the epistemological foundations of contemporary drug prescription reveals an underlying search for scientific legitimacy
Contraceptive and reproductive health practices of unmarried women globally, 1999 to 2018: Systematic review and meta-analysis
Background: Premarital sex practices and contraceptive prevalence rate (CPR) among unmarried women worldwide remain unclear, even though unmarried women tend to have multiple sex partners over time, which makes their sexual behaviors particularly important to the sexual and reproductive health of society more broadly.
Methods: We searched the MEDLINE, PubMed, and Google Scholar databases for relevant articles published between January 1, 1999 and December 31, 2018. Data on prevalence of premarital sexual intercourse, use of highly prevalent contraceptive methods, as well as CPR overall and at first sexual intercourse were extracted and estimated using a DerSimonian- Laird random effects model.
Results: Of the 3918 articles identified, 37 covering 19 countries were included. The estimated overall prevalence of premarital sexual intercourse was 41.9% (95%CI 34.2-49.6%). Pooled CPR was 57.0% (95%CI 44.3-69.8%) overall and 57.6% (95% CI 39.5- 75.6%) at first intercourse. The overall prevalence of condom use was 51.2% (95%CI 42.7-59.7%), followed by oral contraceptives (20.5%, 95%CI 13.7-27.3%), withdrawal (12.7%, 95%CI 9.4-15.9%), and rhythm (12.1%, 95%CI 6.7-17.4%).
Conclusion: The findings of this global study indicate worrying trends in unprotected intercourse and contraceptive practices, suggesting the need for greater attention and resources aimed at educating unmarried adolescent women about sexual and reproductive health
Interventions for treating depression after stroke
Background: Depression is an important consequence of stroke that impacts on recovery yet is often not detected or inadequately treated. This is an update of a Cochrane review first published in 2004. Objectives: To determine whether pharmaceutical, psychological, or electroconvulsive treatment (ECT) of depression in patients with stroke can improve outcome. Search strategy: We searched the trials registers of the Cochrane Stroke Group (last searched October 2007) and the Cochrane Depression Anxiety and Neurosis Group (last searched February 2008). In addition, we searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2008), MEDLINE (1966 to May 2006), EMBASE (1980 to May 2006), CINAHL (1982 to May 2006), PsycINFO (1967 to May 2006) and other databases. We also searched reference lists, clinical trials registers, conference proceedings and dissertation abstracts, and contacted authors, researchers and pharmaceutical companies. Selection criteria: Randomised controlled trials comparing pharmaceutical agents with placebo, or various forms of psychotherapy or ECT with standard care (or attention control), in patients with stroke, with the intention of treating depression. Data collection and analysis: Two review authors selected trials for inclusion and assessed methodological quality; three review authors extracted, cross-checked and entered data. Primary analyses were the prevalence of diagnosable depressive disorder at the end of treatment. Secondary outcomes included depression scores on standard scales, physical function, death, recurrent stroke and adverse effects. Main results: Sixteen trials (17 interventions), with 1655 participants, were included in the review. Data were available for 13 pharmaceutical agents, and four trials of psychotherapy. There were no trials of ECT. The analyses were complicated by the lack of standardised diagnostic and outcome criteria, and differing analytic methods. There was some evidence of benefit of pharmacotherapy in terms of a complete remission of depression and a reduction (improvement) in scores on depression rating scales, but there was also evidence of an associated increase in adverse events. There was no evidence of benefit of psychotherapy. Authors' conclusions: A small but significant effect of pharmacotherapy (not psychotherapy) on treating depression and reducing depressive symptoms was found, as was a significant increase in adverse events. More research is required before recommendations can be made about the routine use of such treatments
The matrix model version of AGT conjecture and CIV-DV prepotential
Recently exact formulas were provided for partition function of conformal
(multi-Penner) beta-ensemble in the Dijkgraaf-Vafa phase, which, if interpreted
as Dotsenko-Fateev correlator of screenings and analytically continued in the
number of screening insertions, represents generic Virasoro conformal blocks.
Actually these formulas describe the lowest terms of the q_a-expansion, where
q_a parameterize the shape of the Penner potential, and are exact in the
filling numbers N_a. At the same time, the older theory of CIV-DV prepotential,
straightforwardly extended to arbitrary beta and to non-polynomial potentials,
provides an alternative expansion: in powers of N_a and exact in q_a. We check
that the two expansions coincide in the overlapping region, i.e. for the lowest
terms of expansions in both q_a and N_a. This coincidence is somewhat
non-trivial, since the two methods use different integration contours:
integrals in one case are of the B-function (Euler-Selberg) type, while in the
other case they are Gaussian integrals.Comment: 27 pages, 1 figur
Can vitamin D supplementation improve grip strength in elderly nursing home residents? A double-blinded controlled trial
Influence of Lifestyle Redesign® on health, social participation, leisure and mobility of older French-Canadians
Importance: Developed in California to enable community-dwelling older adults to maintain healthy and meaningful activities, Lifestyle Redesign® is a well-known cost-effective preventive occupational therapy intervention. The impact of a newly adapted French version on older French-Canadians was, however, unknown.
Objective: To explore the influence of Lifestyle Redesign on older French-Canadians’ health, social participation, leisure, and mobility.
Design: A mixed-methods design included a preexperimental component (questionnaires administered before and after the intervention and 3 and 6 mo postintervention) and an exploratory descriptive qualitative clinical study. Individual semidirected interviews were digitally audiotaped and transcribed, then underwent thematic content analysis using mix extraction grids.
Setting: Community.
Participants: Sixteen volunteers (10 women) aged 65–90 yr (mean = 76.4, standard deviation = 7.6), 10 without and 6 with disabilities. Inclusion criteria were age ≥65 yr, normal cognitive functions, residence in a conventional or senior home, and French speaking.
Intervention: French-Canadian 6-mo version of Lifestyle Redesign.
Outcomes and Measures: Health, social participation, leisure, and mobility were measured using the 36-item Short Form Health Survey, Social Participation Scale, Leisure Profile, and Life-Space Assessment, as well as a semistructured interview guide.
Results: The French-Canadian Lifestyle Redesign had a beneficial effect on participants’ mental health (p = .02) and interest in leisure (p = .02) and, in those with disabilities, social participation (p = .03) and attitudes toward leisure (p = .04). Participants reported positive effects on their mental health, leisure, mobility, and social participation, including frequency and quality of social interactions, and indicated that having an occupational routine fostered better health. None of the participants reported no effect.
Conclusion and Relevance: The translated and culturally adapted Lifestyle Redesign is a promising occupational therapy intervention for community-dwelling older French-Canadians
Molecular evidence of adenosine deaminase linking adenosine A2A receptor and CD26 proteins
Adenosine is an endogenous purine nucleoside that acts in all living systems as a homeostatic network regulator through many pathways, which are adenosine receptor (AR)-dependent and -independent. From a metabolic point of view, adenosine deaminase (ADA) is an essential protein in the regulation of the total intracellular and extracellular adenosine in a tissue. In addition to its cytosolic localization, ADA is also expressed as an ecto-enzyme on the surface of different cells. Dipeptidyl peptidase IV (CD26) and some ARs act as binding proteins for extracellular ADA in humans. Since CD26 and ARs interact with ADA at opposite sites, we have investigated if ADA can function as a cell-to-cell communication molecule by bridging the anchoring molecules CD26 and A2AR present on the surfaces of the interacting cells. By combining site-directed mutagenesis of ADA amino acids involved in binding to A2AR and a modification of the bioluminescence resonance energy transfer (BRET) technique that allows detection of interactions between two proteins expressed in different cell populations with low steric hindrance (NanoBRET), we show direct evidence of the specific formation of trimeric complexes CD26-ADA-A2AR involving two cells. By dynamic mass redistribution assays and ligand binding experiments, we also demonstrate that A2AR-NanoLuc fusion proteins are functional. The existence of this ternary complex is in good agreement with the hypothesis that ADA could bridge T-cells (expressing CD26) and dendritic cells (expressing A2AR). This is a new metabolic function for ecto-ADA that, being a single chain protein, it has been considered as an example of moonlighting protein, because it performs more than one functional role (as a catalyst, a costimulator, an allosteric modulator and a cell-to-cell connector) without partitioning these functions in different subunits
Proton Magnetic Resonance Spectroscopy Reveals Neuroprotection by Oral Minocycline in a Nonhuman Primate Model of Accelerated NeuroAIDS
Background: Despite the advent of highly active anti-retroviral therapy (HAART), HIV-associated neurocognitive disorders continue to be a significant problem. In efforts to understand and alleviate neurocognitive deficits associated with HIV, we used an accelerated simian immunodeficiency virus (SIV) macaque model of NeuroAIDS to test whether minocycline is neuroprotective against lentiviral-induced neuronal injury. Methodology/Principal Findings: Eleven rhesus macaques were infected with SIV, depleted of CD8+ lymphocytes, and studied until eight weeks post inoculation (wpi). Seven animals received daily minocycline orally beginning at 4 wpi. Neuronal integrity was monitored in vivo by proton magnetic resonance spectroscopy and post-mortem by immunohistochemistry for synaptophysin (SYN), microtubule-associated protein 2 (MAP2), and neuronal counts. Astrogliosis and microglial activation were quantified by measuring glial fibrillary acidic protein (GFAP) and ionized calcium binding adaptor molecule 1 (IBA-1), respectively. SIV infection followed by CD8+ cell depletion induced a progressive decline in neuronal integrity evidenced by declining N-acetylaspartate/creatine (NAA/Cr), which was arrested with minocycline treatment. The recovery of this ratio was due to increases in NAA, indicating neuronal recovery, and decreases in Cr, likely reflecting downregulation of glial cell activation. SYN, MAP2, and neuronal counts were found to be higher in minocycline-treated animals compared to untreated animals while GFAP and IBA-1 expression were decreased compared to controls. CSF and plasma viral loads were lower in MN-treated animals. Conclusions/Significance: In conclusion, oral minocycline alleviates neuronal damage induced by the AIDS virus
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