227 research outputs found
Widest scales in turbulent channels
The widest spanwise scales in turbulent channel flows are studied through the
use of three periodic channel-flow simulations at friction Reynolds number
. The length and height of the channels are the same in
all cases ( and respectively), while the width is
progressively doubled: . The effects of
increasing the domain can not be determined with statistical significance in
our simulations, since the difference in the statistics between the simulations
is of the same order as the errors of convergence. A channel flow similar to
the smaller one (, vol. 500, 2004, pp. 135--144),
which was averaged over a very long time, was used as a reference. The
one-dimensional spanwise spectrum of the streamwise velocity is computed with
the aim of assessing the domain-size effect on the widest scales. Our results
indicate that of the total streamwise energetic fluctuations is
recovered without a significant influence of the size of the domain. The
remaining of the energy reflects that the widest scales in the outer
layer are the ones most significantly affected by the spanwise length of the
domain. The power-spectral density for remains constant even if the
size of the domain in the spanwise direction is increased up to 4 times the
standard spanwise length, indicating that wide, spanwise coherent structures
are not an artifact of domain truncation
Mechanism of morphology development in HDGEBA/PAMS hybrid thermosets: Monte Carlo simulation and LSCM study
Reactive combinations of aliphatic epoxy resins and functional polysiloxanes form a class of hybrid thermosetting materials with properties that may come from both the organic and the inorganic phases. The two typically immiscible phases form a suspension whose morphology, composition, and thermal properties vary with curing time. The aim of this research was to elucidate the mechanism by which morphology changed with time and to simulate it through Metropolis-Monte Carlo. The selected system was hydrogenated epoxy (HDGEBA) and a synthetic polyaminosiloxane (PAMS). It was studied by DSC, FTnIR, gel point, viscometry, and in-situ laser scanning confocal microscopy. A mechanism for morphology generation was proposed and simulated, exploring a wide range of values of the "a priori" relevant variables. The essential features were captured by simulations with a reasonable agreement with experimental data. However, the complete process was more complex than the geometrical approach of the simulation. The main deviations that were found and qualitatively explained are: (i) the induction period on the rate of coalescence, and (ii) PAMS-rich domain average size increases faster than predictions.This research was funded by project PID2021-125302NB-I00 financed by the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) and FEDER Una manera de hacer Europa, and TED2021-131847B-C21 financed by the Spanish Ministry of Science and Innovation (Refs: MCIN/AEI/10.13039/501100011033) and Union Europea NextGenationEU/PRT
Effect of different types of exercise on health-related quality of life during and after cancer treatment: a protocol for a systematic review and network meta-analysis
INTRODUCTION: Cancer (and survival) is known to affect the quality of life. Strategies as physical activity and exercise during and after cancer may improve health-related qualify of life (HRQOL) outcomes and are, therefore, of clinical and public health importance. To the best of our knowledge, comparative evidence of the effect of the different types of exercise on improving HRQOL in cancer patients has not been synthesised thus far. We aim to conduct a systematic review and network meta-analysis in order to synthesise all available evidence regarding the effect of different types of exercise interventions on HRQOL during and after cancer treatment. METHODS AND ANALYSIS: MEDLINE (via PubMed), Web of Science, Embase, The Cochrane Library and SPORTDiscus will be searched from inception to December 2018 for relevant randomised controlled trials (RCTs) and non-RCTs. Studies assessing physical activity and exercise interventions in cancer patients (during treatment) and survivors (after treatment) will be selected. Two independent reviewers will identify eligible studies. After quality appraisal and data extraction, we will conduct meta-analyses for outcomes of interest, including data from mental and physical dimensions of cancer-specific and/or generic HRQOL questionnaires. Risk of bias assessments will be completed using the Quality Assessment Tool for Quantitative Studies. Study heterogeneity will be measured by the I2 statistic. Bayesian (and traditional approach) network meta-analysis will be performed when possible to determine the comparative effect of the different physical activity or exercise interventions. ETHICS AND DISSEMINATION: This systematic review and network meta-analysis will synthesise evidence on the effect of different types of exercise interventions on HRQOL during and after cancer treatment. The results will be disseminated by publication in a peer-reviewed journal and through scientific conferences and symposia. Ethical approval will not be required because the data used for this work will be exclusively extracted from published studies
Comportamiento termomecánico de un acero microaleado al Nb-V
Empleando ensayos de compresión simple en ca-
liente y relajación de tensiones después de la de
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formación en un dilatómetro modelo DIL805T, se
obtuvieron las curvas de fluencia y relajación de
dos aceros, el primero de ellos al C – Mn y otro HS-
LA con idéntica composición química base, micro-
aleado con Nb – V.
Los ensayos de compresión simple fueron efectua-
dos a temperaturas en el rango austenítico, desde
900 – 1.200 ºC y velocidades de deformación de
0.001, 0.01, 0.1, 1 y 10 s
-
1
. Se obtuvieron las curvas de
fluencia para las diferentes condiciones, permitien-
do el estudio del efecto de los elementos microale-
antes sobre la recristalización dinámica y la micro-
estructura final; pudiendo comprobar mediante un
análisis microestructural el efecto retardador en la
cinética de recristalización que presenta el acero
microaleado, el incremento en la deformación críti-
ca y en la energía de activación. Se determina asi-
mismo por medio del método de relajación de ten
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siones la cinética de precipitación, elaborando los
diagramas precipitación – temperatura – tiempoPostprint (published version
User-centered design of a gamified mental health app for adolescents in sub-Saharan Africa: multicycle usability testing study
Background:
There is an urgent need for scalable psychological treatments to address adolescent depression in low-resource settings. Digital mental health interventions have many potential advantages, but few have been specifically designed for or rigorously evaluated with adolescents in sub-Saharan Africa.
Objective:
This study had 2 main objectives. The first was to describe the user-centered development of a smartphone app that delivers behavioral activation (BA) to treat depression among adolescents in rural South Africa and Uganda. The second was to summarize the findings from multicycle usability testing.
Methods:
An iterative user-centered agile design approach was used to co-design the app to ensure that it was engaging, culturally relevant, and usable for the target populations. An array of qualitative methods, including focus group discussions, in-depth individual interviews, participatory workshops, usability testing, and extensive expert consultation, was used to iteratively refine the app throughout each phase of development.
Results:
A total of 160 adolescents from rural South Africa and Uganda were involved in the development process. The app was built to be consistent with the principles of BA and supported by brief weekly phone calls from peer mentors who would help users overcome barriers to engagement. Drawing on the findings of the formative work, we applied a narrative game format to develop the Kuamsha app. This approach taught the principles of BA using storytelling techniques and game design elements. The stories were developed collaboratively with adolescents from the study sites and included decision points that allowed users to shape the narrative, character personalization, in-app points, and notifications. Each story consists of 6 modules (“episodes”) played in sequential order, and each covers different BA skills. Between modules, users were encouraged to work on weekly activities and report on their progress and mood as they completed these activities. The results of the multicycle usability testing showed that the Kuamsha app was acceptable in terms of usability and engagement.
Conclusions:
The Kuamsha app uniquely delivered BA for adolescent depression via an interactive narrative game format tailored to the South African and Ugandan contexts. Further studies are currently underway to examine the intervention’s feasibility, acceptability, and efficacy in reducing depressive symptoms
Identification of the phosphorylation sites on the E3 ubiquitin ligase Pellino that are critical for activation by IRAK1 and IRAK4
The E3 ubiquitin ligase Pellino can be activated by phosphorylation in vitro, catalyzed by IL-1 receptor-associated kinase 1 (IRAK1) or IRAK4. Here, we show that phosphorylation enhances the E3 ligase activity of Pellino 1 similarly with any of several E2-conjugating enzymes (Ubc13-Uev1a, UbcH4, or UbcH5a/5b) and identify 7 amino acid residues in Pellino 1 whose phosphorylation is critical for activation. Five of these sites are clustered between residues 76 and 86 (Ser-76, Ser-78, Thr-80, Ser-82, and Thr-86) and decorate a region of antiparallel β-sheet, termed the “wing,” which is an appendage of the forkhead-associated domain that is thought to interact with IRAK1. The other 2 sites are located at Thr-288 and Ser-293, just N-terminal to the RING-like domain that carries the E3 ligase activity. Unusually, the full activation of Pellino 1 can be achieved by phosphorylating any one of several different sites (Ser-76, Thr-86, Thr-288, or Ser-293) or a combination of other sites (Ser-78, Thr-80, and Ser-82). These observations imply that dephosphorylation of multiple sites is required to inactivate Pellino 1, which could be a device for prolonging Pellino's E3 ubiquitin ligase activity in vivo
The adolescent HIV executive function and drumming (AHEAD) study, a feasibility trial of a group drumming intervention amongst adolescents with HIV
AHEAD feasibility trial assessed the feasibility and acceptability of an 8-session group drummingprogramme aiming to improve executive function, depression and anxiety symptoms, andperceived social support in adolescents living with HIV in a rural low-income South Africansetting. Sixty-eight 12- to 19-year-old adolescents participated. They were individuallyrandomised. The intervention arm (n= 34) received weekly hour-long group drumming sessions.Controls (n= 34) received no intervention. Feasibility and acceptability were assessed usingrates of: enrolment; retention; attendance; logistical problems; adolescent-reportedacceptability. Secondary measures included:five Oxford Cognitive Screen-Executive Function(OCS-EF) tasks; two Rapid Assessment of Cognitive and Emotional Regulation (RACER) tasks; theSelf-Reporting Questionnaire-20 (SRQ-20) measuring depression and anxiety symptoms; theMultidimensional Scale of Perceived Social Support (MSPSS). All feasibility criteria were withingreen progression limits. Enrolment, retention, and acceptability were high. There was a positive effect on adolescent depressed mood with a signal for a working memory effect. There were no significant effects on executive function or socio-emotional scales. Qualitative findings suggested socio-emotional benefits including group belonging; decreased internalised stigma; improved mood; and decreased anxiety. Group drumming is a feasible and acceptable intervention among adolescents living with HIV in rural South Africa. A full-scale trial is recommendedAfrica-Oxford Initiative (AfiOx-32), the Society for Education, Music and Psychology Research (SEMPRE) Gerry Farrell scholarship, the Murray Speight grant, the Rhodes Trust, and the Medical Research Council United Kingdom.https://www.tandfonline.com/loi/caic20Musi
JASON-1 CALVAL experiences in Cape of Begur and Ibiza island
The direct and indirect calibration experiences made at the Cape of Begur area in 1999, 2000 and 2002, for Topex/Poseidon and at the Ibiza island in 2003 have contributed to the international campaigns made at Harvest (USA), Corsica (France) and Bass (Australia).
The main objective of IBIZA 2003 campaign has been the determination of the instantaneous sea surface/marine geoid gradient along Jason-1 tracks using a GPS catamaran and a network of GPS located in Portinatx and Ibiza and San Antonio harbours. The marine geoid will be used to relate the tide gauge coastal data with the altimeter data. We present the first results obtained with static and kinematic analysis of the data using different softwares.Peer ReviewedPostprint (published version
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