6,887 research outputs found
Identifying the Distribution of Treatment Effects under Support Restrictions
The distribution of treatment effects (DTE) is often of interest in the
context of welfare policy evaluation. In this paper, I consider partial
identification of the DTE under known marginal distributions and support
restrictions on the potential outcomes. Examples of such support restrictions
include monotone treatment response, concave treatment response, convex
treatment response, and the Roy model of self-selection. To establish
informative bounds on the DTE, I formulate the problem as an optimal
transportation linear program and develop a new dual representation to
characterize the identification region with respect to the known marginal
distributions. I use this result to derive informative bounds for concrete
economic examples. I also propose an estimation procedure and illustrate the
usefulness of my approach in the context of an empirical analysis of the
effects of smoking on infant birth weight. The empirical results show that
monotone treatment response has a substantial identifying power for the DTE
when the marginal distributions of the potential outcomes are given
Transcriptomic and proteomic studies on longevity induced by over-expression of HSP22 in drosophila melanogaster
Le vieillissement est un processus complexe accompagné par une capacité diminuée des cellules à tolérer et répondre aux formes différentes de stress causant des dommages comme l'agrégation de protéine dans les différentes composantes de la cellule. Les chaperons sont des joueurs probablement importants dans le processus de vieillissement en prévenant la dénaturation et l'agrégation des protéines. Chez Drosophila melanogaster, une petite protéine de choc thermique, Hsp22, localisée dans la matrice mitochondriale montre une expression elevée pendant le vieillissement. Sa surexpression chez la mouche augmente la durée moyenne de vie ainsi que la résistance au stress. Bien que Hsp22 montre une activité de chaperon dans des essais in vitro, les mécanismes par lesquels Hsp22 permet d’accroitre la durée de vie in vivo sont toujours inconnus. Une analyse transcriptionelle de tout le génome par microarrays et une analyse comparative du protéome mitochondrial par MALDI-TOF a été entreprise pour dévoiler les différences d’expression entre les mouches surexprimant Hsp22 et les contrôles appropriés. La surexpression générale de Hsp22 en utilisant le système GAL4/UAS dans Drosophila résulte en une augmentation de ~ 30% dans la durée de vie moyenne. L'analyse du transcriptome suggère que Hsp22 joue un rôle dans la détermination de durée de vie en changeant le processus général de vieillissement normal. Effectivement, les mouches surexprimant Hsp22 affichent une surexpression de gènes dont l’expression baisse normalement durant le vieillissement. Les gènes sont impliqués dans la production d'énergie, la biosynthèse des protéines, le taux de renouvellement des protéines et le métabolisme lipidique. L'analyse du protéome mitochondrial soutient aussi un rôle de Hsp22 sur la détermination de la durée de vie en maintenant la fonction mitochondriale et en favorisant la protéolyse. Les présentes données suggèrent l'importance de la maintenance de l’homéostasie protéique durant le vieillissement et discutent des mécanismes potentiels d’extension de la longévitié chez les mouches surexprimant Hsp22.Aging is a complex process accompanied by a decreased capacity of cells to tolerate and respond to various forms of stresses leading to damages such as protein aggregation in various components of the cell. Chaperones are thus likely important players in the aging process by preventing protein denaturation and aggregation. In Drosophila melanogaster, a small heat shock protein Hsp22 localized in the mitochondrial matrix is preferentially up-regulated during aging. Its over-expression results in an extension of lifespan and an increased resistance to stress. Although Hsp22 has been shown to have a chaperone-like activity in vitro, the mechanisms by which it extends lifespan in vivo are still unknown. Genome-wide transcriptional analysis by microarray and comparative mitochondrial proteomic analysis by MALDI-TOF mass analysis have been performed to unveil differences in long-lived Hsp22 over-expressing flies and normal-lived control flies. Ubiquitous over-expression of Hsp22 using the GAL4/UAS system in Drosophila resulted in a ~ 30% increase in mean lifespan. The genomic analysis suggests that Hsp22 plays a role in lifespan determination by altering the regulation of the overall process of normal aging. Indeed, flies over-expressing Hsp22 display an up-regulation of genes normally down-regulated with age and involved in energy production, protein biosynthesis, protein turnover, and lipid metabolism. Mitochondrial proteomic analysis also supports a putative role of Hsp22 on lifespan determination by maintaining mitochondrial function and favoring proteolysis. The present data suggest the importance of the maintenance of protein homeostasis in aging and potential mechanisms of longevity in the Hsp22 over-expressing flies
Process and lessons of international development cooperation through multi industry cluster project
A case of drug-coated balloon treatment for three-vessel stenosis with left main bifurcation lesion
Effect of a Er, Cr:YSGG laser and a Er:YAG laser treatment on oral biofilm-contaminated titanium
Implant surface decontamination is a challenging procedure for therapy of peri-implant disease. Objective: This study aimed to compare the effectiveness of decontamination on oral biofilm-contaminated titanium surfaces in Er:YAG laser, Er, Cr:YSGG laser, and plastic curette. Methodology: For oral biofilms formation, six participants wore an acrylic splint with eight titanium discs in the maxillary arch for 72 hours. A total of 48 contaminated discs were distributed among four groups: untreated control; decontamination with plastic curettes; Er, Cr:YSGG laser; and Er:YAG laser irradiation. Complete plaque removal was estimated using naked-eye and the time taken was recorded; the residual plaque area was measured and the morphological alteration of the specimen surface was observed by scanning electron microscopy. The total bacterial load and the viability of adherent bacteria were quantified by live or dead cell labeling with fluorescence microscopy. Results: The mean treatment time significantly decreased based on the treatment used in the following order: Er:YAG, Er, Cr:YSGG laser, and plastic curettes (234.9±25.4 sec, 156.1±12.7 sec, and 126.4±18.6 sec, P=0.000). The mean RPA in the Er, Cr:YSGG laser group (7.0±2.5%) was lower than Er:YAG and plastic curettes groups (10.3±2.4%, 12.3±3.6%, p=0.023). The viable bacteria on the titanium surface after Er, Cr:YSGG laser irradiation was significantly lower compared to the decontamination with plastic curette (P=0.05) but it was not significantly different from the Er:YAG laser irradiation. Conclusion: We found that Er:YAG laser and Er, Cr:YSGG laser irradiation were effective methods for decontaminations without surface alterations
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