Explanation in the Social Sciences. A Theoretical and Empirical Introduction

A natural or social phenomenon is explained when one presents its description (what?), finds the laws which account for its causes (why?) and provides the micro-level mechanisms underpinning its occurrence (how?). Usually, social sciences explain thanks to theoretical models which are later on logically discussed and empirically tested. Phenomena like strikes, charities, wars or inflation are accounted for through models which causally connect social variables. However, a complete explanation is reached only if the actions and interactions underpinning the social event are also pointed out. Thus, causal explanations based on variables must be supplemented with intentional explanations based on rational actions aiming at instrumental or value-goals. Eventually, the author illustrates the way history accounts for the events of the past, by means of analytical narrations, where unique occurrences are combined with causal and intentional social scientific explanations. The book, by means of clear arguments and simple reasoning, provides a basic introduction to the above mentioned philosophical and methodological topics. Many empirical examples, tables and figures make the assimilation of the subject-matter easier

Best Practice in P.E. for gender equity-A review

This review wants to provide a summary of selected literature from the past 10 years on gender equity in P.E. It aims at providing an overview of the current research, while suggesting viable solutions to encourage girls to take a more active role in sport and physical activity. To ensure the respect of gender identity in education, the quality of teaching is crucial. Therefore, we argue that there is greater need for research in the field of gender equity in PE. While much research focused on how gender reproduced though pedagogical practice in PE, this review aims at analyzing how to challenge it and identify good practices. The analysis of the didactic process pointed out five dimensions (design, methodological, reflexive, organizational, relational). For each dimension, the critical aspects for education to gender equity have been identified, together with the effective practice and strategy to promote gender equity and equal education in PE. Methods and techniques useful for PE teachers were highlighted to give teachers the right tools to orientate students to sports, limit early sport dropouts and valorise the practice of all sports equally, as disciplines for both men and women. Key words: gender, physical education, didactic, curriculum, reflexive thinking, equity, methodology

Sodium current in rat and cat thalamocortical neurons:role of a non-inactivating component in tonic and burst firing

The properties of the Na+ current present in thalamocortical neurons of the dorsal lateral geniculate nucleus were investigated in dissociated neonate rat and cat neurons and in neurons from slices of neonate and adult rats using patch and sharp electrode recordings. The steady-state activation and inactivation of the transient Na+ current (INa) was well fitted with a Boltzmann curve (voltage of half-maximal activation and inactivation, V1/2, -29.84 mV and -70.04 mV, respectively). Steady-state activation and inactivation curves showed a small region of overlap, indicating the occurrence of a / Na window current.  / Na decay could be fitted with a single exponential function, consistent with the presence of only one channel type. Voltage ramp and step protocols showed the presence of a noninactivating component of the Na+ current (/ NaP) that activated at potentials more negative (V1/2 = -56.93 mV) than those of INa. The maximal amplitude of / NaP was approximately 2.5% of INa, thus significantly greater than the calculated contribution (0.2%) of the I Na window component. Comparison of results from dissociated neurons and neurons in slices suggested a dendritic as well as a somatic localization of I NaP. Inclusion of papain in the patch electrode removed the fast inactivation of / Na and induced a current with voltage-dependence (V1/2 = -56.92) and activation parameters similar to those of I NaP. Current-clamp recordings with sharp electrodes showed that I NaP contributed to depolarizations evoked from potentials of approximately -60 mV and unexpectedly to the amplitude and latency of low-threshold Ca2+ potentials, suggesting that this noninactivating component of the Na+ channel population plays an important role in the integrative properties of thalamocortical neurons during both tonic and burst-firing patterns

Health warning labels on alcohol products - the views of Australian university students

While Australian legislation does not currently require health warning labels on alcohol products, several medical and advocacy organisations have been campaigning for their mandatory inclusion. The current study examines the attitudes and opinions of university students (a particularly high risk group) relating to these messages, and the likelihood of such labeling influencing personal behaviours, in order to establish whether the introduction of these labels is likely to be effective. Alcohol warning labels have the potential to influence behaviours of adolescents and young adults, especially if modifications are made to the content and format of these – suggestions are given in this paper. Finally, results of this research indicate that such health messages must be integrated with other educational measures and strategies aiming to internalise alcohol risk information by changing beliefs and, ultimately, behaviours

Study of sequential semileptonic decays of b hadrons produced at the Tevatron

We present a study of rates and kinematical properties of lepton pairs contained in central jets with transverse energy E_T > 15 GeV that are produced at the Fermilab Tevatron collider. We compare the data to a QCD prediction based on the HERWIG and QQ Monte Carlo generator programs.We find that the data are poorly described by the simulation, in which sequential semileptonic decays of single b quarks (b --> l c X with c --> l s X) are the major source of such lepton pairs.Comment: 25 pages, 8 figures. Some typos were fixed in the text and bibliography. Submitted to Phys. Rev.

Calibration of thickness-dependent k-factors for germanium X-ray lines to improve energy-dispersive X-ray spectroscopy of SiGe layers in analytical transmission electron microscopy

We show that the accuracy of energy-dispersive X-ray spectroscopy can be improved by analysing and comparing multiple lines from the same element. For each line, an effective k-factor can be defined that varies as a function of the intensity ratio of multiple lines (e.g. K/L) from the same element. This basically performs an internal self-consistency check in the quantification using differently absorbed X-ray lines, which is in principle equivalent to an absorption correction as a function of specimen thickness but has the practical advantage that the specimen thickness itself does not actually need to be measured

Electrodynamic friction of a charged particle passing a conducting plate

The classical electromagnetic friction of a charged particle moving with prescribed constant velocity parallel to a planar imperfectly conducting surface is reinvestigated. As a concrete example, the Drude model is used to describe the conductor. The transverse electric and transverse magnetic contributions have very different character both in the low velocity (nonrelativistic) and high velocity (ultrarelativistic) regimes. Both numerical and analytical results are given. Most remarkably, the transverse magnetic contribution to the friction has a maximum for $|\mathbf{v}|<c$, and persists in the limit of vanishing resistivity for sufficiently high velocities. We also show how Vavilov-\v{C}erenkov radiation can be treated in the same formalism.Comment: 13 pages, 7 figures. This is the extensively revised version accepted by Physical Review Researc

Sustained neuronal activity generated by glial plasticity

Astrocytes release gliotransmitters, notably glutamate, that can affect neuronal and synaptic activity. In particular, astrocytic glutamate release results in the generation of NMDA receptor (NMDA-R)-mediated slow inward currents (SICs) in neurons. However, factors underlying the emergence of SICs and their physiological roles are essentially unknown. Here we show that, in acute slices of rat somatosensory thalamus, stimulation of lemniscal or cortical afferents results in a sustained increase of SICs in thalamocortical (TC) neurons that outlasts the duration of the stimulus by 1 h. This long-term enhancement of astrocytic glutamate release is induced by group I metabotropic glutamate receptors and is dependent on astrocytic intracellular calcium. Neuronal SICs are mediated by extrasynaptic NR2B subunit-containing NMDA-Rs and are capable of eliciting bursts. These are distinct from T-type Ca2+ channel-dependent bursts of action potentials and are synchronized in neighboring TC neurons. These findings describe a previously unrecognized form of excitatory, nonsynaptic plasticity in the CNS that feeds forward to generate local neuronal firing long after stimulus termination