VELOCITY-BASED MODELING OF THE THERMAL LOAD FOR A FORMULA SAE’S DISK BRAKE SIMULATION

This paper proposes a methodology for the estimation of a disk brake’s thermal load based on its vehicle’s velocity, where this thermal load serves as an input for a numerical simulation. The load is estimated through a balance between variation in the mechanical energy of the vehicle and the energy dissipated via aerodynamic and rolling drag forces. The RS Racing UFRGS team provided the vehicle’s data and geometry, and the velocity data was taken from a real endurance competition. The thermal load thus calculated is then used as input for a 3D transient finite element model containing the disk and the wheel hub. The results are consistent with what is expected by the RS Racing UFRGS team. Based on the results of the 3D transient model, two more simplified analysis are viable: one in permanent regime, which achieves a temperature distribution within the oscillation presented on the transient model; and also a 2D analysis which can be made by the replacement of the wheel hub with an equivalent global heat transfer coefficient

Mitochondrial DNA Repair in Neurodegenerative Diseases and Ageing

Mitochondria are the only organelles, along with the nucleus, that have their own DNA. Mitochondrial DNA (mtDNA) is a double-stranded circular molecule of ~16.5 kbp that can exist in multiple copies within the organelle. Both strands are translated and encode for 22 tRNAs, 2 rRNAs, and 13 proteins. mtDNA molecules are anchored to the inner mitochondrial membrane and, in association with proteins, form a structure called nucleoid, which exerts a structural and protective function. Indeed, mitochondria have evolved mechanisms necessary to protect their DNA from chemical and physical lesions such as DNA repair pathways similar to those present in the nucleus. However, there are mitochondria-specific mechanisms such as rapid mtDNA turnover, fission, fusion, and mitophagy. Nevertheless, mtDNA mutations may be abundant in somatic tissue due mainly to the proximity of the mtDNA to the oxidative phosphorylation (OXPHOS) system and, consequently, to the reactive oxygen species (ROS) formed during ATP production. In this review, we summarise the most common types of mtDNA lesions and mitochondria repair mechanisms. The second part of the review focuses on the physiological role of mtDNA damage in ageing and the effect of mtDNA mutations in neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease. Considering the central role of mitochondria in maintaining cellular homeostasis, the analysis of mitochondrial function is a central point for developing personalised medicine

Diagnóstico: cáncer. ¿Queremos conocer la verdad?

ObjetivoConocer los deseos de información y otras actitudes ante el diagnóstico de cáncerDiseñoEstudio descriptivo transversaEmplazamientoCentros de Salud de Irún, Oñati y Asteasu en GipuzkoaParticipantesDe las citaciones a las 19 consultas durante marzo-mayo del 2002 se obtuvo una muestra aleatoria, prospectiva y sistemática, estratificada por cupos (n=725). Se administró una encuestamodificada de Fernández Díaz en la que se recogieron los datos personales y 8preguntas con respuestas cerradas: aspectos de comunicación (5 ítems) y actitudes relacionadas con la muerte (3 ítems)ResultadosEl 81,3% (IC del 95%, 78,4- 84,1) quiere conocer su diagnóstico. El 68,9% (IC del 95%, 65,5–72,2) elige al médico para comunicarlo. De éstos, el 36,6%, al especialista, y el 26,6%, al médicode familia. Si el afectado es un familiar, el 46,6% (IC del 95%, 42,9–50,2) se lo dirían siempre, sólo si él lo pregunta el 38,6% (ICdel 95%, 35–42,1) y nunca el 9,6% (IC del 95%, 7,4–11,7). El 49,3% (IC del 95%,45,6–52,9) preferiría morir en casa. Para el 44% (IC del 95%, 40,3–47,6) el dolor es el mayor temorConclusionesLa mayoría de la población quiere que se le informe de su diagnóstico, sin que el hábitat urbano o rural o la experiencia de haber tenido familiares con cáncer modifique la opinión. Si el afectadode cáncer es un familiar, son muy pocos los partidarios de no decírselo nunca. Eligen almédico para transmitir la información,prefieren morir en casa y el dolor es lamayor preocupaciónObjectivesTo find people's desire for information and their other attitudes when faced with a cancer diagnosisDesignTransversal, descriptive studySettingIrun, Oñati and Asteasu Health Centres, Gipuzkoa, SpainParticipantsFrom the appointments for 19 clinics in March-May 2002, a randomised, prospective and systematic sample, stratified by lists, was extracted (n=725). A modified Fernández Díaz questionnaire was administered. It had personal details and 8questions with closed replies on aspects of communication (5) and attitudes to death (3Results81.3% (95% CI, 78.4–84.1) wanted to know their diagnosis. 68.9% (95% CI, 65.5- 72.2) chose the doctor to tell them. Of these, 6.6% chose the specialist and 26.6%, thegeneral practitioner. If the person affected was a family member, 46.6% (95% CI, 42.9–50.2) would always tell the person; 38.6% (95% CI, 35–42.1), only if the person asked; and 9.6%, never (95% CI, 7.4–11.7). 49.3% (95% CI, 45.6–52.9) would prefer to die at home. The greatest fear for 44% (95% CI, 40.3–47.6) waspainConclusionsMost people want to be informed of their diagnosis. Neither an urban or rural environment nor having had family members with cancer affects their view. If the personaffected by cancer is a family member, very few people favour not telling him/her at all. Sufferers want the doctor to tell them the information, prefer to die at home and pain is what worries them mos

Comparative analysis of MIS capacitance structures with high-k dielectrics under gamma, 16O and p Radiation

MIS capacitance structures, with Hafnium Oxide, Alumina and nanolaminate as dielectrics were studied under gamma photons Co, 25 MeV oxygen ions and 10 MeV protons radiation using capacitance-voltage (C-V) characterization. The main trend of the results shows that the nanolaminates stack presents the highest levels of hysteresis and stretch-out of the C-V curves, suggesting that interface layers between dielectrics could play a relevant role in the study of the radiation response.Fil: Quinteros, C. P.. Comisión Nacional de Energía Atómica; ArgentinaFil: Sambuco Salomone, Lucas Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Redin, Eduardo Gabriel. Universidad de Buenos Aires; ArgentinaFil: Rafí, J. M.. Consejo Superior de Investigaciones Científicas; EspañaFil: Zabala, M.. Consejo Superior de Investigaciones Científicas; EspañaFil: Faigón, A.. Universidad de Buenos Aires; ArgentinaFil: Palumbo, Félix Roberto Mario. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Campabadal, F.. Consejo Superior de Investigaciones Científicas; Españ

Serotypes and Clonal Composition of Streptococcus pneumoniae Isolates Causing IPD in Children and Adults in Catalonia before 2013 to 2015 and after 2017 to 2019 Systematic Introduction of PCV13

Clones; Invasive pneumococcal disease; SerotypesClones; Enfermedad neumocócica invasiva; SerotiposClons; Malaltia pneumocòcica invasiva; SerotipsThe goal of this study was to investigate the distribution of serotypes and clonal composition of Streptococcus pneumoniae isolates causing invasive pneumococcal disease (IPD) in Catalonia, before and after systematic introduction of PCV13. Pneumococcal strains isolated from normally sterile sites obtained from patients of all ages with IPD received between 2013 and 2019 from 25 health centers of Catalonia were included. Two study periods were defined: presystematic vaccination period (2013 and 2015) and systematic vaccination period (SVP) (2017 to 2019). A total of 2,303 isolates were analyzed. In the SVP, there was a significant decrease in the incidence of IPD cases in children 5 to 17 years old (relative risk [RR] 0.61; 95% confidence interval [CI] 0.38 to 0.99), while there was a significant increase in the incidence of IPD cases in 18- to 64-year-old adults (RR 1.33; 95% CI 1.16 to 1.52) and adults over 65 years old (RR 1.23; 95% CI 1.09 to 1.38). Serotype 8 was the major emerging serotype in all age groups except in 5- to 17-year-old children. In children younger than 5 years old, the main serotypes in SVP were 24F, 15A, and 3, while in adults older than 65 years they were serotypes 3, 8, and 12F. A significant decrease in the proportions of clonal complexes CC156, CC191, and ST306 and an increase in those of CC180, CC53, and CC404 were observed. A steady decrease in the incidence of IPD caused by PCV13 serotypes indicates the importance and impact of systematic vaccination. The increase of non-PCV13 serotypes highlights the need to expand serotype coverage in future vaccines and rethink vaccination programs for older adults. IMPORTANCE We found that with the incorporation of the PCV13 vaccine, the numbers of IPD cases caused by serotypes included in this vaccine decreased in all of the age groups. Still, there was an unforeseen increase of the serotypes not included in this vaccine causing IPD, especially in the >65-year-old group. Moreover, a significant increase of serotype 3 included in the vaccine has been observed; this event has been reported by other researchers. These facts call for the incorporation of more serotypes in future vaccines and a more thorough surveillance of the dynamics of this microorganism

Search for Lorentz and CPT Violation Effects in Muon Spin Precession

The spin precession frequency of muons stored in the $(g-2)$ storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for: a nonzero $\Delta\omega_{a}$ (=$\omega_{a}^{\mu^{+}}-\omega_{a}^{\mu^{-}}$); and a sidereal variation of $\omega_{a}^{\mu^{\pm}}$. No significant effect is found, and the following limits on the standard-model extension parameters are obtained: $b_{Z} =-(1.0 \pm 1.1)\times 10^{-23}$ GeV; $(m_{\mu}d_{Z0}+H_{XY}) = (1.8 \pm 6.0 \times 10^{-23})$ GeV; and the 95% confidence level limits $\check{b}_{\perp}^{\mu^{+}}< 1.4 \times 10^{-24}$ GeV and $\check{b}_{\perp}^{\mu^{-}} < 2.6 \times 10^{-24}$ GeV.Comment: 5 pages, 3 figures, submitted to Physical Review Letters, Modified to answer the referees suggestion

The Muon Anomalous Magnetic Moment and the Standard Model

The muon anomalous magnetic moment measurement, when compared with theory, can be used to test many extensions to the standard model. The most recent measurement made by the Brookhaven E821 Collaboration reduces the uncertainty on the world average of a_mu to 0.7 ppm, comparable in precision to theory. This paper describes the experiment and the current theoretical efforts to establish a correct standard model reference value for the muon anomaly.Comment: Plenary Talk; PANIC'02 XVI Particles and Nuclear International Conference, Osaka, Japan; Sept. 30 - Oct. 4, 2002; Report describes the published 0.7 ppm result and updates the theory statu

Improved Measurement of the Positive Muon Anomalous Magnetic Moment

A new measurement of the positive muon's anomalous magnetic moment has been made at the Brookhaven Alternating Gradient Synchrotron using the direct injection of polarized muons into the superferric storage ring. The angular frequency difference omega_{a} between the angular spin precession frequency omega_{s} and the angular orbital frequency omega_{c} is measured as well as the free proton NMR frequency omega_{p}. These determine R = omega_{a} / omega_{p} = 3.707~201(19) times 10^{-3}. With mu_{mu} / mu_{p} = 3.183~345~39(10) this gives a_{mu^+} = 11~659~191(59) times 10^{-10} (pm 5 ppm), in good agreement with the previous CERN and BNL measurements for mu^+ and mu^-, and with the standard model prediction.Comment: 4 pages, 4 figures. accepted for publication in Phys. Rev. D62 Rapid Communication

An Improved Limit on the Muon Electric Dipole Moment

Three independent searches for an electric dipole moment (EDM) of the positive and negative muons have been performed, using spin precession data from the muon g-2 storage ring at Brookhaven National Laboratory. Details on the experimental apparatus and the three analyses are presented. Since the individual results on the positive and negative muon, as well as the combined result, d=-0.1(0.9)E-19 e-cm, are all consistent with zero, we set a new muon EDM limit, |d| < 1.9E-19 e-cm (95% C.L.). This represents a factor of 5 improvement over the previous best limit on the muon EDM.Comment: 19 pages, 15 figures, 7 table

Search for Lorentz and CPT Violation Effects in Muon Spin Precession

The spin precession frequency of muons stored in the $(g-2)$ storage ring has been analyzed for evidence of Lorentz and CPT violation. Two Lorentz and CPT violation signatures were searched for: a nonzero $\Delta\omega_{a}$ (=$\omega_{a}^{\mu^{+}}-\omega_{a}^{\mu^{-}}$); and a sidereal variation of $\omega_{a}^{\mu^{\pm}}$. No significant effect is found, and the following limits on the standard-model extension parameters are obtained: $b_{Z} =-(1.0 \pm 1.1)\times 10^{-23}$ GeV; $(m_{\mu}d_{Z0}+H_{XY}) = (1.8 \pm 6.0 \times 10^{-23})$ GeV; and the 95% confidence level limits $\check{b}_{\perp}^{\mu^{+}}< 1.4 \times 10^{-24}$ GeV and $\check{b}_{\perp}^{\mu^{-}} < 2.6 \times 10^{-24}$ GeV.Comment: 5 pages, 3 figures, submitted to Physical Review Letters, Modified to answer the referees suggestion