3,703 research outputs found
Effects of acute transcranial direct current stimulation in hot and cold working memory tasks in healthy and depressed subjects
Holographic phase transition from dyons in an AdS black hole background
We construct a dyon solution for a Yang-Mills-Higgs theory in a 4 dimensional
Schwarzschild-anti-de Sitter black hole background with temperature T. We then
apply the AdS/CFT correspondence to describe the strong coupling regime of a
2+1 quantum field theory which undergoes a phase transition exhibiting the
condensation of a composite charge operator below a critical temperature .Comment: 19 pages, 7 figures. Minor corrections, references added. Version
published in JHEP
The impact of sport participation on bone mass and geometry in adolescent males
Exercise is an effective approach for developing bone mass and adolescence is a key period to optimize bone health. However, sports specific training may have different effects on bone outcomes. This study examined the differences on bone outcomes between osteogenic (football) and non-osteogenic (swimming and cycling) sports and a control group in adolescent males. Methods: One hundred twenty one males (13.1±0.1 years) were measured: 41 swimmers,
37 footballers, 29 cyclists and 14 controls. Dual energy X-ray absorptiometry measured bone mineral density (BMD) and content (BMC) at lumbar spine, right and left hip and total body. Hip structural analysis evaluated bone geometry at the femoral neck. Quantitative ultrasound evaluated bone stiffness at both feet. Results: Footballers had significantly higher BMD at total body less head (7-9%), total hip (12-2%) and legs (7-11%) compared to all groups and significantly higher BMD at the femoral neck than controls (14%). Cyclists had higher BMD at the trochanter (10%) and BMC at the arms (10%) compared to controls. Geometrical analysis showed that footballers had significantly higher cross-sectional area (8-19%) compared to all groups, cross-sectional moment of inertia (17 %) compared to controls and section modulus
compared to cyclists (11%) and controls (21%). Footballers had significantly higher bone stiffness compared to all groups (10-20%) at the dominant foot and (12-13%) at the nondominant foot compared to swimmers and controls. Conclusions: Adolescent male footballers exhibited higher bone density, geometry and stiffness compared to swimmers, cyclists and
controls. Although swimmers and cyclists had higher bone outcomes compared to controls, these differences were not significant.The research leading to these results has received funding from the European Union Seventh Framework Programme ([FP7/2007-2013] under grant agreement n°. PCIG13-GA-2013-618496
Soft tissues, areal bone mineral density and hip geometry estimates in active young boys: The PRO-BONE study
This is the final version of the article. Available from Springer Verlag via the DOI in this record.Purpose: Soft tissues, such as fat mass (FM) and lean mass (LM), play an important role in bone development but this is poorly understood in highly active youths. The objective of this study was to determine whether FM or LM is a stronger predictor of areal bone mineral density (aBMD) and hip geometry estimates in a group of physically active boys after adjusting for height, chronological age, moderate-to-vigorous physical activity (MVPA), FM, and LM. Methods: Participants included 121 boys (13.1±1.0 years) from the PRO-BONE study. Bone mineral content (BMC) and aBMD measured at total body, femoral neck and lumbar spine using dual-energy X-ray absorptiometry (DXA), and hip structural analysis was used to estimate bone geometry at the femoral neck. Body composition was assessed using DXA. The relationships of FM and LM with bone outcomes were analysed using simple and multiple linear regression analyses. Results: Pearson correlation coefficients showed that total body (less head) aBMD was significantly correlated with LM but not FM. Multiple linear regression analyses showed that FM, after accounting for height, age, MVPA and LM had no significant relationship
with aBMD or hip geometry estimates, except for arms aBMD. By contrast, there were positive associations between LM and most aBMD and hip geometry estimates, after accounting height, age, MVPA and FM. Conclusions: The results of this study suggest that LM, and not FM, is the stronger predictor of aBMD and hip geometry estimates in physically active boys.The research leading to these results has received funding from the European Union Seventh Framework Programme ([FP7/2007–2013] under grant agreement no. PCIG13-GA-2013-618496
An Aromatic Dyad Motif in Dye Decolourising Peroxidases Has Implications for Free Radical Formation and Catalysis
Dye decolouring peroxidases (DyPs) are the most recent class of heme peroxidase to be discovered. On reacting with H2O2, DyPs form a high‐valent iron(IV)‐oxo species and a porphyrin radical (Compound I) followed by stepwise oxidation of an organic substrate. In the absence of substrate, the ferryl species decays to form transient protein‐bound radicals on redox active amino acids. Identification of radical sites in DyPs has implications for their oxidative mechanism with substrate. Using a DyP from Streptomyces lividans, referred to as DtpA, which displays low reactivity towards synthetic dyes, activation with H2O2 was explored. A Compound I EPR spectrum was detected, which in the absence of substrate decays to a protein‐bound radical EPR signal. Using a newly developed version of the Tyrosyl Radical Spectra Simulation Algorithm, the radical EPR signal was shown to arise from a pristine tyrosyl radical and not a mixed Trp/Tyr radical that has been widely reported in DyP members exhibiting high activity with synthetic dyes. The radical site was identified as Tyr374, with kinetic studies inferring that although Tyr374 is not on the electron‐transfer pathway from the dye RB19, its replacement with a Phe does severely compromise activity with other organic substrates. These findings hint at the possibility that alternative electron‐transfer pathways for substrate oxidation are operative within the DyP family. In this context, a role for a highly conserved aromatic dyad motif is discussed
Hydrogel-Assisted Antisense LNA Gapmer Delivery for In Situ Gene Silencing in Spinal Cord Injury
After spinal cord injury (SCI), nerve regeneration is severely hampered due to the establishment of a highly inhibitory microenvironment at the injury site, through the contribution of multiple factors. The potential of antisense oligonucleotides (AONs) to modify gene expression at different levels, allowing the regulation of cell survival and cell function, together with the availability of chemically modified nucleic acids with favorable biopharmaceutical properties, make AONs an attractive tool for novel SCI therapy developments. In this work, we explored the potential of locked nucleic acid (LNA)-modified AON gapmers in combination with a fibrin hydrogel bridging material to induce gene silencing in situ at a SCI lesion site. LNA gapmers were effectively developed against two promising gene targets aiming at enhancing axonal regeneration—RhoA and GSK3ß. The fibrin-matrix-assisted AON delivery system mediated potent RNA knockdown in vitro in a dorsal root ganglion explant culture system and in vivo at a SCI lesion site, achieving around 75% downregulation 5 days after hydrogel injection. Our results show that local implantation of a AON-gapmer-loaded hydrogel matrix mediated efficient gene silencing in the lesioned spinal cord and is an innovative platform that can potentially combine gene regulation with regenerative permissive substrates aiming at SCI therapeutics and nerve regeneration.This work was supported by Fundação para a Ciência e a Tecnologia ( FCT , Portugal) in the framework of the Harvard-Portugal Medical School Program ( HMSP-ICT/0020/2010 ); Project NORTE-01-0145-FEDER-000008 , supported by the Norte Portugal Regional Operational Programme (NORTE 2020) , under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) ; Fundo Europeu de Desenvolvimento Regional funds through COMPETE 2020 - Operational Program for Competitiveness and Internationalization (POCI) , Portugal 2020; by Portuguese funds through FCT/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project “Institute for Research and Innovation in Health Sciences” ( POCI-01-0145-FEDER-007274 ); Marie Curie Actions of the European Community’s 7th Framework Program ( PIEF-GA-2011-300485 to P.M.D.M.); Santa Casa da Misericordia de Lisboa – Prémio Neurociências Mello e Castro , and FCT fellowship SFRH/BPD/108738/2015 (to P.M.D.M). Funding for open access charge: Project NORTE-01-0145-FEDER-000012 , financed by Norte Portugal Regional Operational Programme (NORTE 2020) , under the PORTUGAL 2020 Partnership Agreement, through the ERDF . We would like to acknowledge the support from Paula Magalhães and Tânia Meireles from the i3S Cell Culture and Genotyping Core Facility in real-time PCR experiments
Determinants of bone outcomes in adolescent athletes at baseline: the PRO-BONE study
This is the author accepted manuscript. The final version is available from the American College of Sports Medicine (ACSM) via the DOI in this record.Purpose: The determinants of areal bone mineral density (aBMD) and hip geometry 26 estimates in adolescent athletes are poorly understood. This study aimed to identify the 27 determinants of aBMD and hip geometry estimates in adolescent male athletes. Methods: 28 One hundred twenty one males (13.1±0.1 years) were measured: 41 swimmers, 37 29 footballers, 29 cyclists and 14 controls. Dual energy X-ray absorptiometry (DXA) measured 30 aBMD at lumbar spine, femoral neck (FN) and total body. Hip structural analysis evaluated 31 hip geometry estimates at the FN. Multiple linear regression examined the contribution of the 32 sports practised, stature, lean and fat mass, serum calcium and vitamin D, moderate to 33 vigorous physical activity (MVPA), vertical jump and cardiorespiratory fitness (CRF) with 34 aBMD and hip geometry estimates. Results: Region specific lean mass was the strongest 35 positive predictor of aBMD (β = 0.614 - 0.931) and football participation was the next 36 strongest predictor (β = 0.304 - 0.579). Stature (β = 0.235 - 0.380), fat mass (β = 0.189), 37 serum calcium (β = 0.103), serum vitamin D (β = 0.104 - 0.139) and vertical jump (β = 0.146 38 - 0.203) were associated with aBMD across various specific sites. All hip geometry estimates 39 were associated with lean mass (β = 0.370 - 0.568) and stature (β = 0.338 - 0.430). Football 40 participation was associated with hip cross-sectional area (β = 0.322) and MVPA (β = 0.140 - 41 0.142). CRF (β = 0.183 - 0.207) was associated with section modulus and cross-sectional 42 moment of inertia. Conclusions: Region specific lean mass is the strongest determinant of 43 aBMD and hip geometry estimates in adolescent male athletes. Football participation and 44 stature were important determinants for aBMD and hip geometry estimates while the 45 contribution of the other predictors was site specific.The research leading to these results has received funding from the European Union Seventh Framework Programme ([FP7/2007-2013] under grant agreement n°. PCIG13-GA-2013-61849
RIESGO CARDIOVASCULAR DEL PERSONAL DE ENFERMERÍA EN EL ÁREA QUIRÚRGICA
The aim of the present investigation was to determine cardiovascular risk factors, through the Framingham model, in the Infirmary Personnel in the surgical area of the Instituto Autónomo Hospital Universitario de Los Andes Merida-Venezuela. A descriptive, field, and cross section study was made, with a population of 43 nurses. The analysis and interpretation of the results were made by descriptive statistics. Test results and the laboratory analysis proved that since age was a non modifiable factor, most of them were in the young adulthood and mature adulthood periods with low cardiovascular risk. As regards modifiable factors, it was determined that more than half had Total Cholesterol at normal levels. In relation to HDL Cholesterol, according to laboratory tests the results showed a high percentage of low values such as <40 mg/dl, which translates as a possible increase of cardiovascular disease risk. As for smoking, more than half of the Infirmary Personnel declared not to have smoking habits. As for Arterial Pressure levels, it was determined that more than half of the professionals were within the normal parameters. When calculating the cardiovascular risk at 10 years, according to the Framingham Model, most of the nurses were located as “Very Low” and “Low” risk of suffering cardiovascular disease in 10 years. Nevertheless, 18.61% had a “Moderate” “High” and “Very High” risk of suffering cardiovascular diseases in the future, which requires proposing promotion and prevention activities aimed at improving the working and health conditions of the Infirmary Personnel and at diminishing cardiovascular risks that can affect their individual, family and community health.La presente investigación tuvo como objetivo determinar los factores de riesgo cardiovascular, a través del modelo de Framingham, en el Personal de Enfermería que labora en el área quirúrgica, Instituto Autónomo Hospital Universitario de Los Andes Mérida-Venezuela. Se realizó un estudio de tipo descriptivo, de campo y de corte transversal, con una población determinada por 43 enfermeras. El análisis e interpretación de los resultados se realizó con estadística descriptiva. Los resultados del test y los exámenes de laboratorio evidenciaron que siendo la edad un factor no modificable, la mayoría se encuentran en el periodo adultez joven y adultez madura con bajo riesgo cardiovascular. Con respecto a los factores modificables, se determinó que del Colesterol Total más de la mitad presentó niveles normales. En relación al Colesterol HDL, según los exámenes de laboratorio los resultados reflejaron: un alto porcentaje mostró cifras bajas, es decir <40 mg/dl, lo cual se traduce en un posible aumento del riesgo a enfermedad cardiovascular. En cuanto al tabaquismo, más de la mitad del Personal de Enfermería manifestó no poseer hábitos tabáquicos. En lo referente a la medición de la Presión Arterial, se encontró que más de la mitad de los profesionales se encuentran en parámetros normales. Al calcular el riesgo cardiovascular a 10 años, según el Modelo de Framingham, la mayoría de las enfermeras, se ubicaron en “Muy Bajo” y “Bajo” riesgo de padecer enfermedad cardiovascular a 10 años. Sin embargo, el 18,61 % tienen un riesgo “Moderado”, “Alto” y “Muy Alto” de padecer en el futuro enfermedades cardiovasculares, lo que requiere de la propuesta de actividades de promoción y prevención, tendientes a mejorar las condiciones de trabajo y salud del Personal de Enfermería, orientadas a disminuir los riesgos cardiovasculares que puedan afectar su salud individual, familiar y en la comunidad
Regulation of the Respiration Quotient Across Ocean Basins
A key uncertainty for predicting future ocean oxygen levels is the response and feedback of organic matter respiration demand. One poorly constrained component of the respiration demand is the oxygen-to-carbon remineralization ratio—the respiration quotient. Currently, multiple biological hypotheses can explain variation in the respiration quotient of organic matter produced in the surface ocean. To test these hypotheses, we directly quantified the particulate respiration quotient in 715 samples along a meridional section of the Atlantic Ocean and compared to previous Pacific Ocean observations. We demonstrate significant
regional shifts in the respiration quotient and a two-basin average of 1.16. Possible diel oscillations were also
observed in the respiration quotient. Basin and regional variation in the respiration quotient were positively
linked to temperature, N versus P stress, and plankton size structure. These observations suggest a complex
regulation of the respiration quotient with important implications for the regional coupling of carbon and
oxygen cycling
Agreement Between Standard Body Composition Methods to Estimate Percentage of Body Fat in Young Male Athletes.
This is author's accepted manuscript.Final version available from Human Kinetics via the DOI in this record.PURPOSE: To examine the intermethods agreement of dual-energy X-ray absorptiometry (DXA) and foot-to-foot bioelectrical impedance analysis (BIA) to assess the percentage of body fat (%BF) in young male athletes using air-displacement plethysmography (ADP) as the reference method. METHODS: Standard measurement protocols were carried out in 104 athletes (40 swimmers, 37 footballers, and 27 cyclists, aged 12-14 y). RESULTS: Age-adjusted %BF ADP and %BF BIA were significantly higher in swimmers than footballers. ADP correlates better with DXA than with BIA (r = .84 vs r = .60, P < .001). %BF was lower when measured by DXA and BIA than ADP (P < .001), and the bias was higher when comparing ADP versus BIA than ADP versus DXA. The intraclass correlation coefficients between DXA and ADP showed a good to excellent agreement (r = .67-.79), though it was poor when BIA was compared with ADP (r = .26-.49). The ranges of agreement were wider when comparing BIA with ADP than DXA with ADP. CONCLUSION: DXA and BIA seem to underestimate %BF in young male athletes compared with ADP. Furthermore, the bias significantly increases with %BF in the BIA measurements. At the individual level, BIA and DXA do not seem to predict %BF precisely compared with ADP in young athletic populations.This work was done as part of the PRO-BONE
study. It has received funding from the European Union Seventh
Framework Programme (FP7/2007-2013) under grant agreement
no. PCIG13-GA-2013-618496. M.V.N-F. received a PhD
Student Internships Abroad scholarship from the National
Council for Scientific and Technological Development
(CNPq; process: 200340/2015-8) and a Brazilian PhD Student
scholarship from the São Paulo Research Foundation (FAPESP;
process. 2016/18436-8 and 2017/11732-3). E.U-G. received a
PhD scholarship from Universidad de Castilla-La Mancha
(2014/10340). A.C.F.M. received a postdoctoral scholarship
from the São Paulo Research Foundation (FAPESP; process:
2014/13367-2 and 2015/14319-4)
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