Teaching Energy Conservation as a Unifying Principle in Physics

In this work we present the design and assessment of a teaching sequence aimed at introducing the principle of energy conservation at post-compulsory secondary school level (16–18 year olds). The proposal is based on the result of research into teaching-learning difficulties and on the analysis of the physics framework. Evidence is shown that this teaching sequence, together with the methodology used in the classroom, may result in students having a better grasp of the principle of energy conservation.     

How need for cognition affects the processing of achievement-related information

The present article analyzed, how need for cognition (NFC) influences the formation of performance expectancies. When processing information, individuals with lower NFC often rely on salient information and shortcuts compared to individuals higher in NFC. We assume that these preferences of processing will also make individuals low in NFC more responsive to salient achievement-related cues because the processing of salient cues is cognitively less demanding than the processing of non-salient cues. Therefore, individuals lower in NFC should tend to draw wider ranging inferences from salient achievement-related information. In a sample of N = 197 secondary school students, achievement-related feedback (grade on an English examination) affected changes in expectancies in non-corresponding academic subjects (e.g., expectation of final grade in mathematics or history) when NFC was lower, whereas for students with higher NFC, changes in expectancies in non-corresponding academic subjects were not affected.     

The homicide, the pervert act and paternity

Proposition to articulate perverse subjectivity and the pervert act was established, wherein, the dynamics of criminal acts, as means of lust, and convicts＇ positioning within social bonds configure the outlines. For this purpose, imprisoned were registered in unit of Rio de Janeiro Penal System was interviewed. The concept of perversion was a starting point and means for interpretation of the perverse phenomena present in subjects condemned for homicide. Social relationships, geared by violence and crime, offer criminality guaranteed space within its network. The assertive that social plot offers sponsorship, if not incentive, for occurrence and maintenance of crimes may be made, but this statement is uncertain when considering the criminal＇s perception of his role and part therein. This questioning leds to the investigation of imprisoned with the objective of studying the criminal act, the executor＇s implication and types of social engagement related to crime. Discursive production was collected from various interviews and analyzed. The results were： （1） The majority of criminals believe crime necessary and associated to citizen and criminal necessities. （2） The way media discloses criminal acts makes available methods and strategies which can be readily assimilated. （3） Criminals interpret their crimes as sociological-economic needs, a means of social ascension and empowerment, thus revealing remarkable change in customs. （4） Failure, or even absence of a paternal image was evidenced in family pattern study, inasmuch as majority come from women＇s homes with several children, each of different fathers. （5） Uncontrollable increase of criminality may be the consequence of subjective emptiness, observable by maximum concentration of the subject in the ego, allied to the loosening of links fundamental to social relationship. （6） The criminal have low scholastic levels. Homicidal hold the lowest academic level, some being illiterate. （7） Finally, the imprisoned reveal the existence of pleasure in stealing, killing, seizure, blackmailing and assaulting. He practices two categories of actions： （1） Torturer, which includes assailants and kidnappers, has primordial interest in the slow mortification process of the victims, continuous suffering, the abolition of desire and, not immediately, death; （2） Executioner, commonly known as contracted killers, those whose lust derives from the capture of death in those dying whilst dying, have the sole action present with complete dissubjectivation of victim.     

Who is willing to pay for science? On the relationship between public perception of science and the attitude to public funding of science

This article examines the relationship between the general public's understanding of science and the attitude towards public funding of scientific research. It applies a multivariate and discriminant analysis (Wilks' Lambda), in addition to a more commonly used bivariate analysis (Cramer's V), to data compiled from the Third National Survey on the Social Perception of Science and Technology in Spain (FECYT, 2006). The general conclusion is that the multivariate analysis produces information complementary to the bivariate analysis, and that the variables commonly applied in public perception studies have limited predictive value with respect to the attitude towards public funding of scientific research.     

Adding omega-3 fatty acids to a protein-based supplement during pre-season training results in reduced muscle soreness and the better maintenance of explosive power in professional Rugby Union players

Evidence suggests that omega-3 fatty acid supplementation could reduce muscle soreness and maintain muscle function following eccentric exercise-induced muscle damage. The aim of this applied field study was to investigate the effectiveness of consuming a protein-based supplement containing 1546?mg of omega-3 polyunsaturated fatty acid (PUFA) (551?mg eicosapentaenoic acid (EPA) and 551?mg docosahexaenoic acid (DHA)) twice daily (FO) compared to a protein-based placebo (P) on muscle soreness, countermovement jump (CMJ) performance and psychological well-being in 20 professional Rugby Union players during 5 weeks of pre-season training. Players completed a 5-point-Likert soreness scale with 5 indicating “no soreness” and a questionnaire assessing fatigue, sleep, stress and mood each morning of training, plus they performed CMJ tests once or twice per week. Data were analysed using magnitude-based inferential statistics and are presented as percent beneficial/trivial/harmful. On day 35, there was a likely (% beneficial/trivial/harmful: 94/5/1) moderate (0.75, standardized mean difference (SMD)) beneficial effect of FO vs. P on the change in lower body muscle soreness compared with day 0 (FO: ?3.8?±?21.7%; P: ?19.4?±?11.2%). There was a likely (92/7/0) moderate (SMD: 0.60) beneficial effect of FO vs. P on CMJ performance (change from baseline to day 35, FO: +4.6?±?5.9%; P: ?3.4?±?8.6%). From day 20, a moderate beneficial effect of FO on fatigue was observed. In terms of practical relevance, the moderate beneficial effect of adding fish oil to a protein-based supplement on muscle soreness translated into the better maintenance of explosive power in elite Rugby Union players during pre-season training.     

Effect of 8 weeks of concurrent plyometric and running training on spatiotemporal and physiological variables of novice runners

Concurrent plyometric and running training has the potential to improve running economy (RE) and performance through increasing muscle strength and power, but the possible effect on spatiotemporal parameters of running has not been studied yet. The aim of this study was to compare the effect of 8 weeks of concurrent plyometric and running training on spatiotemporal parameters and physiological variables of novice runners. Twenty-five male participants were randomly assigned into two training groups; running group (RG) (n?=?11) and running + plyometric group (RPG) (n?=?14). Both groups performed 8 weeks of running training programme, and only the RPG performed a concurrent plyometric training programme (two sessions per week). Anthropometric, physiological (VO_2max, heart rate and RE) and spatiotemporal variables (contact and flight times, step rate and length) were registered before and after the intervention. In comparison to RG, the RPG reduced step rate and increased flight times at the same running speeds (P?P?P?2max increased more in the RPG than in the RG. In conclusion, concurrent plyometric and running training entails a reduction in step rate, as well as increases in VT speed, RCT speed, peak speed and VO_2max. Athletes could benefit from plyometric training in order to improve their strength, which would contribute to them attaining higher running speeds.     

African American College Students,the Black Church,and Counseling

African American undergraduate students face numerous challenges during college; however, they are less likely to seek help from college counseling services. Often, African Americans seek support from spiritual resources. In the current phenomenological study, participants shared in a focus group interview. Overall, participants seemed to value the Black Church as an integral part of their lives and as an influence on their perceptions of counseling and proclivity to seek counseling services.     

Robust sensorless observer-based adaptive sliding modes control of synchronous motors

Using a nonlinear complete order model of a synchronous motor, a robust second order sliding mode observer based control scheme is proposed. For that, a generalized super-twisting 3rd order observer is proposed for nonlinear systems. Based on the proposed observer scheme, a robust rotor flux observer is designed, then, a stator current observer is proposed using a classical super-twisting algorithm for extracting information of the rotor speed by means of the equivalent control method. The control design for the output tracking of a desired reference signal for the rotor speed is carried out with a classical super-twisting sliding mode algorithm and adaptive backstepping techniques. Due to the number of inputs, the flux in the excitation winding, and the direct component of the stator currents are also regulated. Numeric simulations predict a good performance of the closed-loop synchronous motor with parameter variations.     

The influence of pacing strategy on marathon world records

The aim of this study was to analyse the influence of the pacing strategy adopted by elite marathon runners when setting every marathon world record in the last 50 years. We divided former marathon record holders into two groups: classic athletes (record holders between 1967 and 1988) and contemporaneous athletes (record holders between 1988 and 2018). The total distance of the marathon was divided into 8 sections of 5?km and 1 last section of 2.195?km, and the relative average speed of each section was calculated individually. On average athletes were slightly faster in the first half-marathon than in the second one, where they slowed down progressively (ES?=?0.28, small effect). However, when comparing classic vs. contemporaneous athletes, we observed that classic athletes started significantly faster (p?相似文献