Experimental Method to Determine Some Physical Properties in Physics Classes

ABSTRACT Particle density, gravimetric and volumetric water contents and porosity are important basic concepts to characterize porous systems such as soils. This paper presents a proposal of an experimental method to measure these physical properties, applicable in experimental physics classes, in porous media samples consisting of spheres with the same diameter (monodisperse medium) and with different diameters (polydisperse medium). Soil samples are not used given the difficulty of working with this porous medium in laboratories dedicated to teaching basic experimental physics. The paper describes the method to be followed and results of two case studies, one in monodisperse medium and the other in polydisperse medium. The particle density results were very close to theoretical values for lead spheres, whose relative deviation (RD) was -2.9 % and +0.1 % RD for the iron spheres. The RD of porosity was also low: -3.6 % for lead spheres and -1.2 % for iron spheres, in the comparison of procedures – using particle and porous medium densities and saturated volumetric water content – and monodisperse and polydisperse media.

Lack of hypotriglyceridemic effect of gemfibrozil as a consequence of age-related changes in rat liver PPARalpha.

We have investigated if changes in hepatic lipid metabolism produced by old age are related to changes in liver peroxisome proliferator-activated receptor alpha (PPARalpha). Our results indicate that 18-month-old rats showed a marked decrease in the expression and activity of liver PPARalpha, as shown by significant reductions in PPARalpha mRNA, protein and binding activity, resulting in a reduction in the relative mRNA levels of PPARalpha target genes, such as liver-carnitine-palmitoyl transferase-I (CPT-I) and mitochondrial medium-chain acyl-CoA dehydrogenase (MCAD). Further, in accordance with a liver PPARalpha deficiency in old rats, treatment of old animals with a therapeutic dose of gemfibrozil (GFB) (3mg/kg per day, 21 days) was ineffective in reducing plasma triglyceride concentrations (TG), despite attaining a 50% reduction in TG when GFB was administered to young animals at the same dose and length of treatment. We hypothesize that the decrease in hepatic PPARalpha can be related to a state of leptin resistance present in old animals.

Estudo avaliativo das classes de aceleração na rede estadual paulista

Este artigo descreve os propósitos, a metodologia e os resultados de um estudo avaliativo sobre a implantação do Projeto das Classes de Aceleração no Estado de São Paulo. A realização de seis estudos de caso, em escolas nas quais a implantação foi considerada bem-sucedida, permitiu identificar fatores de sucesso do projeto. A análise de provas de desempenho e de auto-estima de alunos egressos da classes de aceleração indicou a importância de incorporar ao projeto, medidas de médio e longo prazo que ajudem a manter os resultados positivos alcançados.

Alcohol-attributable mortality in Switzerland in 2011--age-specific causes of death and impact of heavy versus non-heavy drinking.

BACKGROUND: Alcohol use causes high burden of disease and injury globally. Switzerland has a high consumption of alcohol, almost twice the global average. Alcohol-attributable deaths and years of life lost in Switzerland were estimated by age and sex for the year 2011. Additionally, the impact of heavy drinking (40+grams/day for women and 60+g/day for men) was estimated. METHODS: Alcohol consumption estimates were based on the Addiction Monitoring in Switzerland study and were adjusted to per capita consumption based on sales data. Mortality data were taken from the Swiss mortality register. Methodology of the Comparative Risk Assessment for alcohol was used to estimate alcohol-attributable fractions. RESULTS: Alcohol use caused 1,600 (95% CI: 1,472 - 1,728) net deaths (1,768 deaths caused, 168 deaths prevented) among 15 to 74 year olds, corresponding to 8.7% of all deaths (men: 1,181 deaths; women: 419 deaths). Overall, 42,627 years of life (9.7%, 95% CI: 40,245 - 45,008) were lost due to alcohol. Main causes of alcohol-attributable mortality were injuries at younger ages (15-34 years), with increasing age digestive diseases (mainly liver cirrhosis) and cancers (particularly breast cancers among women). The majority (62%) of all alcohol-attributable deaths was caused by chronic heavy drinking (men: 67%; women: 48 %). CONCLUSION: Alcohol is a major cause of premature mortality in Switzerland. Its impact, among young people mainly via injuries, among men mainly through heavy drinking, calls for a mix of preventive actions targeting chronic heavy drinking, binge drinking and mean consumption.

Top income shares in Portugal over the twentieth century

[cat] L’objectiu d’aquest article és presentar nova evidència estadística sobre l’evolució de les desigualtats econòmiques a Portugal a llarg termini. L’explotació de les fonts fiscals portugueses ha permès l’estimació annual de les top income shares des de 1936. La construcció d’aquesta nova sèrie s’ha fet seguint la metodologia emprada per Piketty (2001). Aquesta nova sèrie revela una caiguda de les top income shares durant la Segona Guerra Mundial, seguida d’una recuperació fins a principis dels anys cinquanta. Des de mitjans dels cinquanta fins a principis dels anys vuitanta hi ha una caiguda dràstica de les top income shares. Per acabar, durant els anys noranta les top income shares tornen a augmentar. Aquesta pauta és molt similar a la viscuda en altres països: la reducció de les top income shares durant l’època daurada és compartida per tots els països estudiats i el seu increment als anys noranta sembla que alinea Portugal amb la pauta seguida pels països Anglosaxons.

Sperm velocity in an Alpine whitefish: effects of age, size, condition, fluctuating asymmetry and gonad abnormalities

The relationship between sperm velocity and individual age, size, body condition and fluctuating asymmetry was investigated in Alpine whitefish Coregonus fatioi. The fish analysed belonged to one among several sympatric whitefish populations of Lake Thun, Switzerland, which are characterized by a high prevalence of gonad alterations. Therefore, sperm velocity data were also tested for a link between gonad deformation and sperm swimming speed. Sperm velocity was significantly lower in larger-grown individuals and in individuals of higher body condition. As expected, sperm velocity was higher in males with higher levels of fluctuating asymmetry, but it did not significantly vary with male age. Moreover, variation in sperm velocity was found to be significantly higher in individuals showing some types of gonad alterations but it did not significantly correlate with the presence of other types of alterations. (C) 2007 The Authors Journal compilation (C) 2007 The Fisheries Society of the British Isles.

Troubles de la mémoire chez la personne agée: que faire au cabinet [Cognitive impairment in elderly patients: what to do in primary care?].

In Switzerland, each year there are about 25000 new patients suffering from dementia (one new case every 20 minutes!). Currently, recognition of cognitive impairment and dementia diagnoses remain essentially based on clinical features. For the primary care provider, a 4-step approach based on a) history, b) collateral information provided by a knowledgeable relative, c) a standardized brief cognitive screening instrument, and d) simple laboratory tests will identify most older persons suffering from dementia. Unclear situations benefit from an assessment in a memory clinic.

The Lorenz-maximal core allocations and the kernel in some classes of assignment games

En aquest treball demostrem que en la classe de jocs d'assignació amb diagonal dominant (Solymosi i Raghavan, 2001), el repartiment de Thompson (que coincideix amb el valor tau) és l'únic punt del core que és maximal respecte de la relació de dominància de Lorenz, i a més coincideix amb la solucié de Dutta i Ray (1989), també coneguda com solució igualitària. En segon lloc, mitjançant una condició més forta que la de diagonal dominant, introduïm una nova classe de jocs d'assignació on cada agent obté amb la seva parella òptima almenys el doble que amb qualsevol altra parella. Per aquests jocs d'assignació amb diagonal 2-dominant, el repartiment de Thompson és l'únic punt del kernel, i per tant el nucleolo.

[Collection de cartes postales classées méthodiquement pour l'enseignement de la géographie, Paris, F. Nathan, s.d. (1928), offert par l'éditeur. 353 cartes postales en 15 paquets. 1. Généralités, définitions principales (1-25) 2. Ports de commerce, de pêche, militaires, fluviaux (26-50) 3. Pêches et industries diverses (51-75) 4. Relief du sol (76-95) 5. Communications en montagne (96-119) 6. Histoire d'un fleuve (120-139) 7. Phénomènes dus à l'érosion (140-159) 8. Voies de communication (160-179) 9. Paris (180-204) 10. Algérie (205-228) 11. Tunisie (229-253) 12. Maroc (254-278) 13. A.O.F. et A.E.F. (279-303) 14. Madagascar (304-328) 15. Indochine (329-353)]

Donateur : Nathan, Fernand (1858-1947)

Social dysfunctioning after mild to moderate first-ever stroke at vocational age.

BACKGROUND: With improvements in stroke treatments, the number of patients with dramatic recovery is increasing. However, many of them are still complaining of difficulties in returning to work and every day activities. The aim was to assess work and social dysfunctioning in patients with minor to moderate stroke and explore its contributing factors. METHODS: Consecutive patients were prospectively included at a median 7 months after a first-ever stroke. Scores on the Work and Social Adjustment Scale (WSAS), a generic self-reported scale for assessing social functioning, were correlated with scores on the National Institutes of Health Stroke Scale (NIHSS), activities of daily living, Hospital Anxiety and Depression scale (HAD) and MMSE, Iowa Scale of Personality Changes and return to work at 1 year. RESULTS: Among the 84 included patients (mean age 43.5 years), 57 (68%; 95% CI 57 to 78%) complained of significant perturbation of functioning attributed to stroke. WSAS was highly significantly related to modified Rankin scale, daily living activities, Iowa Scale of Personality Changes and return to work at 1 year. Using ordinal logistic regression, the contributors to WSAS were initial neurological severity (NIHSS at admission), HAD and MMSE. CONCLUSIONS: The study showed that up to 68% of our patients complained of significant work and social dysfunction due to stroke, despite a good clinical outcome. This self-estimation was correlated to external validation criteria, stressing the high burden of stroke from the patient's viewpoint. Moreover, when compared across diseases, social dysfunctioning after mild stroke was as important as in other major disabling diseases.

Extreme prematurity and intra uterine growth restriction effects in brain network topology at school age

Higher risk for long-term behavioral and emotional sequelae, with attentional problems (with or without hyperactivity) is now becoming one of the hallmarks of extreme premature (EP) birth and birth after pregancy conditions leading to poor intra uterine growth restriction (IUGR) [1,2]. However, little is know so far about the neurostructural basis of these complexe brain functional abnormalities that seem to have their origins in early critical periods of brain development. The development of cortical axonal pathways happens in a series of sequential events. The preterm phase (24-36 post conecptional weeks PCW) is known for being crucial for growth of the thalamocortical fiber bundles as well as for the development of long projectional, commisural and projectional fibers [3]. Is it logical to expect, thus, that being exposed to altered intrauterine environment (altered nutrition) or to extrauterine environment earlier that expected, lead to alterations in the structural organization and, consequently, alter the underlying white matter (WM) structure. Understanding rate and variability of normal brain development, and detect differences from typical development may offer insight into the neurodevelopmental anomalies that can be imaged at later stages. Due to its unique ability to non-invasively visualize and quantify in vivo white matter tracts in the brain, in this study we used diffusion MRI (dMRI) tractography to derive brain graphs [4,5,6]. This relatively simple way of modeling the brain enable us to use graph theory to study topological properties of brain graphs in order to study the effects of EP and IUGR on childrens brain connectivity at age 6 years old.