Some comprehension problems in kindergarten,

Thesis (M.A.)--Boston Universit

The Modified Dynamics as a Vacuum Effect

Why does there appear in the modified dynamics (MOND) an acceleration constant, a0, of cosmological significance? An intriguing possibility is that MOND, indeed inertia itself--as embodied in the actions of free particles and fields, is due to effects of the vacuum. Either cosmology enters local dynamics by affecting the vacuum, and inertia in turn, through a0; or, the same vacuum effect enters both MOND (through a0) and cosmology (e.g. through a cosmological constant). For the vacuum to serve as substratum for inertia a body must be able to read in it its non-inertial motion; this indeed it can, by detecting Unruh-type radiation. A manifestation of the vacuum is also seen, even by inertial observers, in a non-trivial universe (marked, e.g., by curvature or expansion). A non-inertial observer in a nontrivial universe will see the combined effect. An observer on a constant-acceleration (a) trajectory in a de Sitter universe with cosmological constant L sees Unruh radiation of temperature T\propto [a^2+a0^2]^{1/2}, with a0=(\L/3)^{1/2}. The temperature excess over what an inertial observer sees, T(a)-T(0), turns out to depend on a in the same way that MOND inertia does. An actual inertia-from-vacuum mechanism is still a far cry off.Comment: 6 pages, Latex, version to be published in Physics Letters

Cuadernos para el docente

Horizontes representa una propuesta pedagógica que incluye programas de televisión para las áreas de Lengua, Matemática, Ciencias Sociales y Ciencias Naturales. Su intención es acompañar las actividades de la Escuela Secundaria Rural y difundir contenidos audiovisuales articulados con las unidades didácticas desarrolladas a lo largo de los CUADERNOS DE ESTUDIO de las áreas disciplinares mencionadas

On Local Approximations to the Nonlinear Evolution of Large-Scale Structure

We present a comparative analysis of several methods, known as local Lagrangian approximations, which are aimed to the description of the nonlinear evolution of large-scale structure. We have investigated various aspects of these approximations, such as the evolution of a homogeneous ellipsoid, collapse time as a function of initial conditions, and asymptotic behavior. As one of the common features of the local approximations, we found that the calculated collapse time decreases asymptotically with the inverse of the initial shear. Using these approximations, we have computed the cosmological mass function, finding reasonable agreement with N-body simulations and the Press-Schechter formula.Comment: revised version with color figures, minor changes, accepted for publication in the Astrophysical Journal, 30 pages, 13 figure

Decisao de tratamento para lesoes de carie iniciais e moderadas por estudiantes de odontología e especialistas em odontopediatría do Uruguay

A filosofia de Mínima Intervenção disponibiliza opções de tratamento de lesões cariosas mais conservadoras, englobando tratamentos não invasivos, microinvasivos ou operatórios. O limiar entre o tratamento não operatório operatório das lesões cariosas continua sendo um desafio para a odontologia. O objetivo deste estudo foi comparar as decisões de tratamento para lesões de cárie iniciais e moderadas por estudantes de graduação e especialistas/alunos de especialização em odontopediatria do Uruguai. O presente estudo transversal, avaliou, por meio da aplicação de um questionário contendo 12 diferentes situações clínicas de lesões iniciais e oderadas em molares decíduos e permanentes, em superfícies oclusais e proximais. As respostas foram classificadas em tratamento não operatório e operatório. Metade dos questionários aplicados continha uma imagem ilustrativa do exame radiográfico da lesão clinicamente descrita. Alunos de graduação e especialização em Odontopediatria e Especialistas em Odontopediatria registrados no centro de pós-graduação da Faculdade de Odontologia da Udelar (Uruguai) foram convidados a participar. Para avaliar a associação entre o desfecho (tratamento operatório) em cada situação clínica e as variáveis independentes (grupo participante - estudante de graduação ou especialista; presença da imagem radiográfica: com o sem imagem representativa) foram realizadas análises de Regressão Logística (α=5%). Um total de 225 questionários foram analisados, 173 de estudantes de graduação e 52 de alunos de especialização e especialistas em Odontopediatria. Para lesões ativas em esmalte clinicamente não cavitadas, sem envolvimento radiográfico dentinário mais de 95% dos participantes optaram pelo tratamento não operatório e o tipo de participante e presença de imagem ilustrativa não influenciaram a tomada de decisão (p>0,05). Para as lesões ativas em esmalte clinicamente não cavitadas com profundidade radiográfica em dentina superficial, a presença da ilustração foi associada à uma abordagem mais invasiva (p<0.05). Para as lesões clinicamente microcavitadas em esmalte, e imagem radiográfica em dentina superficial, ser estudante de graduação apresentou uma chance maior de tratamento operatório (p<0.05). Dessa forma, conclui-se que estudantes de graduação tendem a atuar com um enfoque menos conservador para lesões moderadas (radiograficamente em dentina), entretanto, para lesões iniciais, não houve diferença entre os grupos.1 INTRODUÇÃO - 2 REVISÃO DA LITERATURA 2.1 MÉTODO VISUAL 2.2 MÉTODO RADIOGRÁFICO 2.3 DECISÃO DE TRATAMENTO -2.4 QUESTIONÁRIOS - 3 HIPÓTESE -4 OBJETIVOS - 5 METODOLOGIA 5.1 DELINEAMENTO DO ESTUDO E ASPECTOS ÉTICOS - 5.2 SELEÇÃO DA AMOSTRA E CRITÉRIOS DE ELEGIBILIDADE - 5.3 ESTRUTURAÇÃO DO QUESTIONÁRIO E COLETA DE DADOS. 5.4 ANÁLISE ESTATÍSTICA - 6 ARTIGO CIENTÍFICO - 7 CONSIDERAÇÕES FINAIS - 8 REFÊRENCIAS - APENDICE APÊNDICE 1 - APENDICE 2 - ANEXO 1 -ANEXO

Psychological Injury Rehabilitation: The Link Between Body and Mind

Psychological factors, including stress, can increase the likelihood of sustaining an injury as well as inhibit proper recovery, making mental health intervention within athletics crucial to injury prevention and successful recovery. There is extensive research that confirms that mental rehabilitation is equally as important as physical rehabilitation when recovering from an athletic injury. Psychological training during injury rehabilitation greatly improves the likelihood an athlete successfully returns to their sport, as well as increases the given timeline for this recovery process. This paper intends to expand on this data by also exploring the specific mental training strategies that may be most effective.The link between psychological factors and bodily function involves a multitude of specific aspects, none being more important than mind-muscle connection. In the simplest explanation, mind muscle connection is bringing attention to one’s body or specific body part as they move it. Drawing this attention has major implications regarding injury rehabilitation, However mind muscle connection stems farther than just regarding injuries. Studies have shown that having a solid mind muscle connection can improve results in the realm of body building to maximize muscular development (Schoenfeld 2016, Calatayud 2016). Calatayud found that when athletes specifically focus on one muscle during a workout, muscle activity increased by 20% - 60%. If that specific workout incorporated multiple muscle groups, this focus on one muscle did not take away from muscle activity in the other. His results show the importance of mind-muscle connection regarding athletic success.The body goes hand in hand with the mind. In order to have peak performance from the body, the mind must assist along the process. This connection goes for both training and injury rehabilitation. Mind-muscle connection cannot provide the results alone however, the same vigorous training is required for the best results, it is more of an enhancement

Intersection between metabolic dysfunction, high fat diet consumption, and brain aging

Deleterious neurochemical, structural, and behavioral alterations are a seemingly unavoidable aspect of brain aging. However, the basis for these alterations, as well as the basis for the tremendous variability in regards to the degree to which these aspects are altered in aging individuals, remains to be elucidated. An increasing number of individuals regularly consume a diet high in fat, with high‐fat diet consumption known to be sufficient to promote metabolic dysfunction, although the links between high‐fat diet consumption and aging are only now beginning to be elucidated. In this review we discuss the potential role for age‐related metabolic disturbances serving as an important basis for deleterious perturbations in the aging brain. These data not only have important implications for understanding the basis of brain aging, but also may be important to the development of therapeutic interventions which promote successful brain aging.Fil: Uranga, Romina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Bruce Keller, Annadora J.. State University of Louisiana; Estados UnidosFil: Morrison, Christopher D.. State University of Louisiana; Estados UnidosFil: Fernandez Kim, Sun Ok. State University of Louisiana; Estados UnidosFil: Ebenezer, Philip J.. State University of Louisiana; Estados UnidosFil: Zhang, Le. State University of Louisiana; Estados UnidosFil: Dasuri, Kalavathi. State University of Louisiana; Estados UnidosFil: Keller, Jeffrey N.. State University of Louisiana; Estados Unido

High-normal blood glucose levels may be associated with decreased spatial perception in young healthy adults.

The negative effects of high normal glucose on cognitive function were previously reported in euglycemic individuals of middle age and the elderly population. This study aimed at examining the effect of baseline blood glucose levels on spatial ability, specifically verticality perception on the computerized rod and frame test (CRFT) in young healthy adults. 63 healthy male medical students (age range from 18-23 years), of whom 30 were non-fasting outside the month of Ramadan and 33 fasting during Ramadan of the year 2016, were recruited in order to create varying degrees of glycemia during which verticality perception was carried out. Baseline blood glucose reading was obtained prior to commencing the CRFT test. Blood glucose levels at the time of testing decreased as the duration between the last meal and testing increased. A blood glucose range of 62-117 mg/dl was achieved among participants for this study. Linear regression analysis showed that blood glucose level at testing correlated positively with all alignment spatial error parameters, indicating a probable reduction of spatial perception ability with higher blood glucose levels. These results are consistent with other cognitive studies in older healthy humans and emphasize the critical impact of early glucose dys-homeostasis on cognitive function. They also indicate that elevated blood glucose may affect cognitive functioning outside of the usual complications of diabetes

Impulsiveness, postprandial blood glucose and glucoregulation affect measures of behavioral flexibility

Behavioral flexibility (BF) performance is influenced by both psychological and physiological factors. Recent evidence suggests that impulsivity and blood glucose can affect executive function, of which BF is a subdomain. Here, we hypothesized that impulsivity, fasting blood glucose (FBG), glucose changes (i.e. glucoregulation) from postprandial blood glucose (PBG) following the intake of a 15g glucose beverage could account for variability in BF performance. The Stroop Color-Word Test and the Wisconsin Card Sorting Test (WCST) were used as measures of BF, and the Barratt Impulsiveness Scale (BIS-11) to quantify participants’ impulsivity. In Study 1, neither impulsivity nor FBG could predict performance on the Stroop or the WCST. In Study 2, we tested whether blood glucose levels following the intake of a sugary drink, and absolute changes in glucose levels following the intake of the glucose beverage could better predict BF. Results showed that impulsivity and the difference in blood glucose between time 1 (postprandial) and time 2, but not blood glucose levels at time 2 per se could account for variation in performance on the WCST but not on the Stroop task. More specifically, lower impulsivity scores on the BIS-11, and smaller differences in blood glucose levels from time 1 to time 2 predicted a decrease in the number of total and perseverative errors on the WCST. Our results show that measures of impulsivity and glucoregulation can be used to predict BF. Importantly our data extend the work on glucose and cognition to a clinically relevant domain of cognition