Biomecànica de l’arquitectura muscular i potència mecànica de salt en joves

Objectiu: Analitzar les relacions i diferències en potència mecànica en salt i l’arquitectura de la musculatura extensora de les extremitats inferiors en subjectes joves segons el sexe i el nivell d’activitat física. Metodologia: S’han realitzat 3 estudis: 2 de metodològics i 1 d’aplicat. Al Primer es van comparar 2 mètodes d’avaluació de la potència de curta durada basats en salt i en pedaleig. Al Segon es va comparar el mesurament de la potència en salt mitjançant un mètode directe davant d’alguns d’indirectes. Al Tercer es va analitzar la potència de salt i l’arquitectura de la musculatura extensora d’extremitats inferiors en una població d’homes i de dones distribuïts cada un en 3 subgrups amb diferent condició física. Hi van participar 244 subjectes: 9 universitaris; 161 homes aspirants a una Facultat de Ciències de l’Esport; 12 jugadores de voleibol de la Selecció Espanyola; 12 dones i 7 homes jugadors de voleibol de Primera Divisió Nacional; 10 dones i 10 homes de Ciències de l’Esport; 12 dones i 11 homes universitaris sedentaris. Resultats i discussió:  A l’Estudi 1 les potències obtingudes amb tots dos mètodes correlacionaven entre si, però amb el salt es van obtenir valors gairebé 3 vegades superiors. A l’Estudi 2 la punta de potència amb equacions correlacionava amb l’obtingut amb plataforma de forces. No obstant això, totes les equacions han subestimat la potència respecte a la plataforma. A l’Estudi 3, la variable d’arquitectura que millor ha correlacionat amb el salt ha estat el gruix muscular del vast lateral (VL). La població d’homes ha mostrat potències més grans en salt, majors gruixos i longituds de fascicles en VL, i angles de penniació en VL i gastrocnemi lateral (GL) que no pas la de dones. Les dones han mostrat majors longituds de fascicles en GL i gastrocnemi medial (GM) que no pas els homes. Entre subgrups de diferent sexe els d’homes han mostrat més capacitat de salt que els respectius de dones. Entre els subgrups del mateix sexe s’han trobat diferències en potència de salt, però no en arquitectura muscular. Homes i dones semblen presentar diferències de partida en algunes variables d’arquitectura, que els podrien condicionar diferències en el rendiment físic en algunes activitats. Les majors potències dels homes sobre les dones al costat de les diferències en gruix i longitud de fascicles del VL entre els dos i les correlacions trobades fan pensar que l’arquitectura d’aquest ventre condiciona la potència de salt i explica el major rendiment dels homes davant les dones en el salt, però no explicaria les diferències entre subgrups del mateix sexe. Conclusions: Les diferents arquitectures dels subjectes explicarien les diferències en la capacitat de salt entre homes i dones, però no les diferències entre subgrups del mateix sexe. El VL és el ventre que major implicació ha mostrat amb la potència en salt

Dynamic Limits on Planar Libration-Orbit Coupling Around an Oblate Primary

This paper explores the dynamic properties of the planar system of an ellipsoidal satellite in an equatorial orbit about an oblate primary. In particular, we investigate the conditions for which the satellite is bound in librational motion or when the satellite will circulate with respect to the primary. We find the existence of stable equilibrium points about which the satellite can librate, and explore both the linearized and non-linear dynamics around these points. Absolute bounds are placed on the phase space of the libration-orbit coupling through the use of zero-velocity curves that exist in the system. These zero-velocity curves are used to derive a sufficient condition for when the satellite's libration is bound to less than 90 degrees. When this condition is not satisfied so that circulation of the satellite is possible, the initial conditions at zero libration angle are determined which lead to circulation of the satellite. Exact analytical conditions for circulation and the maximum libration angle are derived for the case of a small satellite in orbits of any eccentricity.Comment: Submitted to Celestial Mechanics and Dynamical Astronom

Socioeconomic predictors and consequences of depression among primary care attenders with non-communicable diseases in the Western Cape, South Africa:Cohort study within a randomised trial

Background: Socioeconomic predictors and consequences of depression and its treatment were investigated in 4393 adults with specified non-communicable diseases attending 38 public sector primary care clinics in the Eden and Overberg districts of the Western Cape, South Africa.   Methods: Participants were interviewed at baseline in 2011 and 14 months later, as part of a randomised controlled trial of a guideline-based intervention to improve diagnosis and management of chronic diseases. The 10-item Center for Epidemiologic Studies Depression Scale (CESD-10) was used to assess depression symptoms, with higher scores representing more depressed mood. Results: Higher CESD-10 scores at baseline were independently associated with being less educated (p=0.004) and having lower income (p=0.003). CESD-10 scores at follow-up were higher in participants with less education (p=0.010) or receiving welfare grants (p=0.007) independent of their baseline scores. Participants with CESD-10 scores of 10 or more at baseline (56% of all participants) had 25% higher odds of being unemployed at follow-up (p=0.016), independently of baseline CESD-10 score and treatment status. Among participants with baseline CESD-10 scores of 10 or more, antidepressant medication at baseline was independently more likely in participants who had more education (p=0.002), higher income (p<0.001), or were unemployed (p=0.001). Antidepressant medication at follow up was independently more likely in participants with higher income (p=0.023), and in clinics with better access to pharmacists (p=0.053) and off-site drug delivery (p=0.013).  Conclusions: Socioeconomic disadvantage appears to be both a cause and consequence of depression, and may also be a barrier to treatment. There are opportunities for improving the prevention, diagnosis and treatment of depression in primary care in inequitable middle income countries like South Africa.  Trial registration: The trial is registered with Current Controlled Trials (ISRCTN20283604) and the Office for Human Research Protections Database (IRB00001938, FWA00001637)

Exploring Peer Collaborative Writing in EFL Secondary Mixed-age Classrooms

Based on the beliefs (assertions) that students benefit socially and cognitively from interacting with peers of different ages, mixed-age (M-A) classrooms have attracted much attention from educators, education policymakers, and researchers. Nevertheless, research into the role and impact of age grouping in second (L2) and foreign language (FL) learning is rather scarce. Moreover, a growing body of research has shown that by linking oral and written modes, collaborative writing (CW) aids language learning. However, the majority of studies have investigated adult and young adult students, and very few were conducted with secondary and high school students. Based on our knowledge, no study has explored CW in M-A secondary school classrooms. With these research gaps in mind, and drawing predominantly on documentary analysis of student written work, the present study examined CW of 28 students of English as a foreign language (EFL) aged 12 to 15 old learners who jointly wrote a comic. The findings point to limitations of M-A peer interaction suggesting that there is a threshold for the younger learners in terms of benefiting from CW with their older partners. Similarly, the findings suggest that the extent to which OS benefit is rather limited

GROUND RULES: GIVING MEANING AND EFFECT TO KEY CONTESTED TERMS IN THE CALIFORNIA RACIAL JUSTICE ACT

The California Racial Justice Act (RJA), which applies to all pretrial, trial, and post-conviction defendants, prohibits any state actor from relying upon racial bias to seek or obtain a conviction or sentence against a defendant. In a state where racial disparities in incarceration have been growing for decades, the law, which became retroactive in 2024, has the power to create a sea of change across California criminal institutions. Using the power of state constitutional law and relying upon the principles of comity and federalism, the California Racial Justice Act explicitly rejects the intent-to-discriminate standard set by the U.S. Supreme Court in McCleskey v. Kemp. In its place is a novel two-branched framework to challenge racism either by evidence of bias by system actors, or by demonstrating county-wide racial disparities. Together, these two approaches have the potential to create broad relief from the racial inequality that has long plagued the criminal justice system and eluded other reform efforts. Despite its broad legislative vision, the practical and actual reach of the RJA remains an open question. Thus far, successful claims brought under the RJA—including challenges to the use of rap lyrics in gang cases, and racially biased language used by judges, prosecutors and police—have mostly resulted from evidentiary presentations about specific acts of bias by system actors. Despite the limited litigation focused on system-wide racial disparity, there is already substantial confusion and disagreement about the meaning and nature of key statutory terms — specifically the meaning of ‘similar conduct’ and ‘similarly situated,’ comparisons in the statistical measurement and evaluation of ‘disparity,’ how the relationship between racial bias and case impact is defined, and what constitutes a ‘race neutral’ explanation. In the end, the courts’ interpretation, and thus the ultimate impact of the RJA, will be molded by the ability of defendants to demonstrate systematic disparity in a manner that is both scientifically sound and legally valid. For the RJA to rise to its expansive legislative vision, it will require factual findings and legal conclusions about what constitutes a valid and reliable scientific methodology to quantify racial disparity in crime and punishment. Fortunately, in this, California courts are not alone. Amassing and explaining evidence presented in support of these claims is well within the expertise of statisticians, social scientists, and methodologists. The already conflicting court opinions on the RJA pose questions that can find their answers in statistical and scientific thought, debate, and review that has been established over nearly 100 years. This Article proposes an approach to the interpretations of RJA comparison for ‘similar conduct’ and ‘similarly situated’ cases based on those answers. Additionally, we lay out a related 5-point test on the meaning of ‘race-neutral’ explanation. Our goal is to standardize and streamline RJA litigation while establishing a rigorous and reasonable evidentiary standard that does not unduly burden the prosecution, the defense, or the judiciary

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Feasibility of Implementing an Older Adult Resistance Training Program in a Community Setting

The innovative OYO fitness gym device has the capacity to offer an inclusive resistance training experience for older adults, provided that the internal and external validity of the OYO exercise program is established. PURPOSE: Our purpose is to report the feasibility of implementing this 8-week program at a community senior center in a predominantly Spanish-speaking metropolitan area. METHODS: Feasibility is evaluated through measures of fidelity which include participant demographics, participant responsiveness, quality of delivery, adherence to the Program Manual, and pre-to-post changes in physical function. RESULTS: Twenty-three individuals consented for participation. Two participants completed the full 8-week program with an average class size of five participants. Among the two completers, there was a modest increase in upper body strength (arm curl pre-average=10, arm curl post-average=11.5). 87% of the exercise sessions were completed as planned with a high rate of following the training manual. CONCLUSIONS: Although participant retention declined, these results suggest the most integral parts of the OYO program were still primarily delivered according to the Program Manual. We recommend modifications to the research procedures to improve participant responsiveness in a community-setting

Molecular and phenotypic characterisation of paediatric glioma cell lines as models for preclinical drug development.

Although paediatric high grade gliomas resemble their adult counterparts in many ways, there appear to be distinct clinical and biological differences. One important factor hampering the development of new targeted therapies is the relative lack of cell lines derived from childhood glioma patients, as it is unclear whether the well-established adult lines commonly used are representative of the underlying molecular genetics of childhood tumours. We have carried out a detailed molecular and phenotypic characterisation of a series of paediatric high grade glioma cell lines in comparison to routinely used adult lines