História da ciência no ensino de Física: um estudo sobre o ensino de atração gravitacional desenvolvido com futuros professores

We report here some outcomes of a research related to a didactical experience aiming to integrate the History of Science to the Physics Teaching, taking as background the historical development of the gravitational attraction. The research, of qualitative approach, is a case study and it was carried out in a sample of eleven students belonging to an undergraduate physics program (called licenciatura in Brazil) designed to from High School physics teachers in a São Paulo State Public University. We tried initially to reveal prospective teachers’ conceptions in order to provide a prepare that was used to guide the activities from the reality’s diagnosis. The aim was to promote discussions on the existence and persistence of alternative conceptions, on the historical evolution of the subject gravitational attraction, through readings and debates of texts contemplating recent subjects on the Science Education research, in order to generate dissatisfaction with traditional teaching models. The future High School physics teachers were asked to construct their own teaching proposal, through the development, in real situations, in a High School, of a minicourse based on: debates and synthesis developed in University classroom, the History of the Science and the student’s alternative conceptions. In this paper we will analyze future teachers’ alternative conceptions, the development of the course proposed, and details of the mini-courses taught by the prospective teachers in real situations, among High School students, its coherence and the posture changes observed in them.

Potencial gravitacional lunar

We know that the orbit of a lunar satellite, and consequently its orbital lifetime is mainly inuenced by the gravitational field of the Moon, Earth and Sun. In this text we study the Lunar gravitational potential and its influence on the gravitational field. We adapted a program in order to map the Moon gravitational field. To that end it was necessary to develop a program that allows the simulation and mapping the lunar full potential. Our program was based on the program developed by Hélio Kuga, and adapted to our case (Moon). We used the model proposed by Konopliv et al. 2001, we proposed various degree and order expansions of spherical harmonics that served us to compare and validate our program

Killer Whales and Marine Mammal Trends in The North Pacific—A Re-Examination of Evidence for Sequential Megafauna Collapse and the Prey-Switching Hypothesis

Springer et al. (2003) contend that sequential declines occurred in North Pacific populations of harbor and fur seals, Steller sea lions, and sea otters. They hypothesize that these were due to increased predation by killer whales, when industrial whaling’s removal of large whales as a supposed primary food source precipitated a prey switch. Using a regional approach, we reexamined whale catch data, killer whale predation observations, and the current biomass and trends of potential prey, and found little support for the prey-switching hypothesis. Large whale biomass in the Bering Sea did not decline as much as suggested by Springer et al., and much of the reduction occurred 50–100 yr ago, well before the declines of pinnipeds and sea otters began; thus, the need to switch prey starting in the 1970s is doubtful. With the sole exception that the sea otter decline followed the decline of pinnipeds, the reported declines were not in fact sequential. Given this, it is unlikely that a sequential megafaunal collapse from whales to sea otters occurred. The spatial and temporal patterns of pinniped and sea otter population trends are more complex than Springer et al. suggest, and are often inconsistent with their hypothesis. Populations remained stable or increased in many areas, despite extensive historical whaling and high killer whale abundance. Furthermore, observed killer whale predation has largely involved pinnipeds and small cetaceans; there is little evidence that large whales were ever a major prey item in high latitudes. Small cetaceans (ignored by Springer et al.) were likely abundant throughout the period. Overall, we suggest that the Springer et al. hypothesis represents a misleading and simplistic view of events and trophic relationships within this complex marine ecosystem.

Potencial gravitacional lunar

We know that the orbit of a lunar satellite, and consequently its orbital lifetime is mainly inuenced by the gravitational field of the Moon, Earth and Sun. In this text we study the Lunar gravitational potential and its influence on the gravitational field. We adapted a program in order to map the Moon gravitational field. To that end it was necessary to develop a program that allows the simulation and mapping the lunar full potential. Our program was based on the program developed by Hélio Kuga, and adapted to our case (Moon). We used the model proposed by Konopliv et al. 2001, we proposed various degree and order expansions of spherical harmonics that served us to compare and validate our program

Psychology and psychoanalysis in Brazil - From cultural syncretism to the collapse of liberal individualism

This paper focuses first on cultural syncretism, used to characterize Brazilian culture. The other aspect of this socially and racially blended culture is the unfinished assimilation of liberalism in politics and the economy, which defines Brazilian society. The increased assimilation and dissemination of psychology may be linked with these in cultural and social aspects. During the military period (1964-1974) the major expansion in university-level studies in psychology contributed ideologically to the dissemination of psychology throughout Brazilian society. This introduced a type of psychology that was related primarily to clinical practice and developed in opposition to social work practice. This paper examines the ideological bases for this conflict between clinical and social work. Criteria for understanding the cultural dissemination of psychoanalysis are then discussed, and it is argued that cultural incorporation of psychoanalysis involves the development of discourse complexes to reflect particular aspects of Brazilian society. The criteria (a non-totalitarian society and the displacement of a magical and religious interpretation of mental disturbance by psychiatric interpretation) are evaluated in relation to the peculiarities of Brazilian syncretism. The paper argues that cultural syncretism and the incomplete assimilation of liberal ideology must be included as criteria in understanding the particular cultural incorporation of psychoanalysis in Brazil.

A Comparative Wet Collapse Buckling Study for the Carcass Layer of Flexible Pipes

When there is a failure on the external sheath of a flexible pipe, a high value of hydrostatic pressure is transferred to its internal plastic layer and consequently to its interlocked carcass, leading to the possibility of collapse. The design of a flexible pipe must predict the maximum value of external pressure the carcass layer can be subjected to without collapse. This value depends on the initial ovalization due to manufacturing tolerances. To study that problem, two numerical finite element models were developed to simulate the behavior of the carcass subjected to external pressure, including the plastic behavior of the materials. The first one is a full 3D model and the second one is a 3D ring model, both composed by solid elements. An interesting conclusion is that both the models provide the same results. An analytical model using an equivalent thickness approach for the carcass layer was also constructed. A good correlation between analytical and numerical models was achieved for pre-collapse behavior but the collapse pressure value and post-collapse behavior were not well predicted by the analytical model. [DOI: 10.1115/1.4005185]

He II lambda 4686 IN eta CARINAE: COLLAPSE OF THE WIND-WIND COLLISION REGION DURING PERIASTRON PASSAGE

The periodic spectroscopic events in eta Carinae are now well established and occur near the periastron passage of two massive stars in a very eccentric orbit. Several mechanisms have been proposed to explain the variations of different spectral features, such as an eclipse by the wind-wind collision (WWC) boundary, a shell ejection from the primary star or accretion of its wind onto the secondary. All of them have problems explaining all the observed phenomena. To better understand the nature of the cyclic events, we performed a dense monitoring of eta Carinae with five Southern telescopes during the 2009 low-excitation event, resulting in a set of data of unprecedented quality and sampling. The intrinsic luminosity of the He II lambda 4686 emission line (L similar to 310 L-circle dot) just before periastron reveals the presence of a very luminous transient source of extreme UV radiation emitted in the WWC region. Clumps in the primary's wind probably explain the flare-like behavior of both the X-ray and He II lambda 4686 light curves. After a short-lived minimum, He II lambda 4686 emission rises again to a new maximum, when X-rays are still absent or very weak. We interpret this as a collapse of the WWC onto the "surface" of the secondary star, switching off the hard X-ray source and diminishing the WWC shock cone. The recovery from this state is controlled by the momentum balance between the secondary's wind and the clumps in the primary's wind.

Regional lung perfusion estimated by electrical impedance tomography in a piglet model of lung collapse

Borges JB, Suarez-Sipmann F, Bohm SH, Tusman G, Melo A, Maripuu E, Sandstrom M, Park M, Costa EL, Hedenstierna G, Amato M. Regional lung perfusion estimated by electrical impedance tomography in a piglet model of lung collapse. J Appl Physiol 112: 225-236, 2012. First published September 29, 2011; doi: 10.1152/japplphysiol.01090.2010.-The assessment of the regional match between alveolar ventilation and perfusion in critically ill patients requires simultaneous measurements of both parameters. Ideally, assessment of lung perfusion should be performed in real-time with an imaging technology that provides, through fast acquisition of sequential images, information about the regional dynamics or regional kinetics of an appropriate tracer. We present a novel electrical impedance tomography (EIT)-based method that quantitatively estimates regional lung perfusion based on first-pass kinetics of a bolus of hypertonic saline contrast. Pulmonary blood flow was measured in six piglets during control and unilateral or bilateral lung collapse conditions. The first-pass kinetics method showed good agreement with the estimates obtained by single-photon-emission computerized tomography (SPECT). The mean difference (SPECT minus EIT) between fractional blood flow to lung areas suffering atelectasis was -0.6%, with a SD of 2.9%. This method outperformed the estimates of lung perfusion based on impedance pulsatility. In conclusion, we describe a novel method based on EIT for estimating regional lung perfusion at the bedside. In both healthy and injured lung conditions, the distribution of pulmonary blood flow as assessed by EIT agreed well with the one obtained by SPECT. The method proposed in this study has the potential to contribute to a better understanding of the behavior of regional perfusion under different lung and therapeutic conditions.

NADPH Phagocyte Oxidase Knockout Mice Control Trypanosoma cruzi Proliferation, but Develop Circulatory Collapse and Succumb to Infection

(NO)-N-center dot is considered to be a key macrophage-derived cytotoxic effector during Trypanosoma cruzi infection. On the other hand, the microbicidal properties of reactive oxygen species (ROS) are well recognized, but little importance has been attributed to them during in vivo infection with T. cruzi. In order to investigate the role of ROS in T. cruzi infection, mice deficient in NADPH phagocyte oxidase (gp91(phox-/-) or phox KO) were infected with Y strain of T. cruzi and the course of infection was followed. phox KO mice had similar parasitemia, similar tissue parasitism and similar levels of IFN-gamma and TNF in serum and spleen cell culture supernatants, when compared to wild-type controls. However, all phox KO mice succumbed to infection between day 15 and 21 after inoculation with the parasite, while 60% of wild-type mice were alive 50 days after infection. Further investigation demonstrated increased serum levels of nitrite and nitrate (NOx) at day 15 of infection in phox KO animals, associated with a drop in blood pressure. Treatment with a NOS2 inhibitor corrected the blood pressure, implicating NOS2 in this phenomenon. We postulate that superoxide reacts with (NO)-N-center dot in vivo, preventing blood pressure drops in wild type mice. Hence, whilst superoxide from phagocytes did not play a critical role in parasite control in the phox KO animals, its production would have an important protective effect against blood pressure decline during infection with T. cruzi.

Discovery of hearing impairment by the family: seeing an idealized future collapse

OBJECTIVE: To portray the family experience when the discovery of hearing impairment in their child. METHODS: Qualitative research with Symbolic Interactionism and Grounded Theory as theoretical and methodological frameworks. Data collection instrument: semi-structured interview. The study included nine families (32 participants). RESULTS: The theme, "Seeing an idealized future collapse", shows that for the family, discovered the possibility of having a child with hearing loss is a moment that involves many negative feelings. CONCLUSION: Discover the hearing loss has a meaning of the expected loss of the perfect child, frustrated expectations and uncertain future. The family has been inadequately approached and the diagnosis has been made late, which requires immediate changes to the practices of professionals.

Extended spherical collapse and the accelerating universe

The influence of the shear stress and angular momentum on the nonlinear spherical collapse model is discussed in the framework of the Einstein–de Sitter and ΛCDM models. By assuming that the vacuum component is not clustering within the homogeneous nonspherical overdensities, we show how the local rotation and shear affect the linear density threshold for collapse of the nonrelativistic component (δc) and its virial overdensity (ΔV ). It is also found that the net effect of shear and rotation in galactic scale is responsible for higher values of the linear overdensity parameter as compared with the standard spherical collapse model (no shear and rotation)