The organization and temporal properties of appetitive behavior in rats     

Kathleen M. Silva  William Timberlake 《Learning & behavior》1998,26(2):182-195

In the presence and absence of an externalinterfood clock stimulus (a sequence of flashing lights), rats showed a multimodal behavior pattern during successive quarters of interfood intervals (IFI) ranging from 12 to 192 sec. Responses near the feeder peaked before and just after food presentations, whereas locomotion remote from the feeder peaked toward the middle of the IFI. The temporal patterns of nosing in the feeder and remote locomotion were scalar (the time at which a response peaked in the IFI was proportional to the IFI length), whereas the patterns of postfood feeder-directed behavior, rearing, and pawgrooming were time bound (peaking at a fixed time after food, regardless of IFI length). Responses varied in their control by the external clock stimulus. During the last half of the IFI, rats nosed in the feeder more with an external clock, but only at intermediate IFIs. During the first quarter of the IFI, rats pawgroomed more with an external clock, but only at the longest IFI. The general sequence of responses during the interfood clock was consistent with the view that food delivery engages an organized sequence of search states that are expressed through a variety of responses.  相似文献   

The Spectre of Theory of Curriculum for Educational Research: A Medican Example     

Burgos  Rosa Nidia Buenfil 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1999,45(5-6):461-478

Recent educational policies in many parts of the world have tended to underplay the significance of theory in curriculum debates. This article examines examples of this tendency, paying particular attention to a case study of a prestigious education department at a Mexican university where the curriculum over 18 years was systematically drained of theoretical content. The author argues that removing theoretical discussion from the educational field will damage knowledge production in the field and ultimately harm the practice of education.  相似文献   

Evaluating models of how morphological awareness connects to reading comprehension: A study in Portuguese     

Márcia Oliveira  Kyle C. Levesque  S. Hélène Deacon  Márcia Maria Peruzzi Elia da Mota 《Journal of Research in Reading》2020,43(2):161-179

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Exploring features for the automatic identification of user goals in web search     

Mauro Rojas Herrera  Edleno Silva de Moura  Marco Cristo  Thomaz Philippe Silva  Altigran Soares da Silva 《Information processing & management》2010

Queries submitted to search engines can be classified according to the user goals into three distinct categories: navigational, informational, and transactional. Such classification may be useful, for instance, as additional information for advertisement selection algorithms and for search engine ranking functions, among other possible applications. This paper presents a study about the impact of using several features extracted from the document collection and query logs on the task of automatically identifying the users’ goals behind their queries. We propose the use of new features not previously reported in literature and study their impact on the quality of the query classification task. Further, we study the impact of each feature on different web collections, showing that the choice of the best set of features may change according to the target collection.  相似文献   

Classroom environment in the implementation of an innovative curriculum project in science education     

Mercedes Surez  Rosa Pías  Pedro Membiela  Dolores Dapía 《科学教学研究杂志》1998,35(6):655-671

A curriculum project can be positively or negatively influenced by the environment of the classroom in which it is implemented. Analysis of the perceptions of students, teachers, and external observers has allowed us to study the influence of classroom environment in the implementation of an innovative project in science education. The main conclusions indicate that even though the global evaluation is positive, more so among teachers than among students, there are differences between the perceptions of the participants, probably due to differences in interests and needs. Moreover, in the classroom environment, the teacher and the actual dynamic and spatial organization are of great importance, and it can be difficult to maintain interest or to achieve a satisfactory evaluation on the part of those students whose academic performance is lowest. © 1998 John Wiley & Sons, Inc. J Res Sci Teach 35: 655–671, 1998.  相似文献   

我的书朋友     

罗斯·沃尔多 《语数外学习(初中版)》2009,(12)

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History effects on induced and operant variability     

da Silva Souza A  Abreu-Rodrigues J  Baumann AA 《Learning & behavior》2010,38(4):426-437

Two experiments evaluated history effects on induced and operant variability. College students typed three-digit sequences on a computer keyboard. Sequence variability was induced (by no reinforcement or variation- independent reinforcement) or reinforced (by variation- or repetition-dependent reinforcement). Conditions with induced and operant variability were presented according to a reverse between-groups design. In Experiment 1, we examined transitions from the variation or repetition contingencies to no reinforcement, and vice versa. In Experiment 2, the variation or repetition contingencies were followed or preceded by variation-independent reinforcement. The results showed that (1) a history of no reinforcement impaired operant variability learning; (2) induced variability levels were higher and lower after a history of reinforcement for variation and repetition, respectively; (3) repetition was more easily disrupted by no reinforcement and independent reinforcement than was variation; and (4) response variability and stability were a function of past and current reinforcement conditions. These results indicate that reinforcement history influences both induced and operant variability levels.  相似文献   

The effects of resistance training volume on osteosarcopenic obesity in older women     

Paolo M. Cunha  Alex S. Ribeiro  Crisieli M. Tomeleri  Brad J. Schoenfeld  Analiza M. Silva  Mariana F. Souza 《Journal of sports sciences》2018,36(14):1564-1571

The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0 ± 4.3 years, 26.8 ± 4.4 kg/m²) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n = 21) or 3 sets (G3S, n = 20) 3 times weekly, or a control group (CG, n = 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (P < 0.05) positive changes for G3S than G1S (composed Z-score: G3S = 0.62 ± 0.40; G1S = 0.11 ± 0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.  相似文献   

Protective effects of photobiomodulation against resistance exercise-induced muscle damage and inflammation in rats     

Helenita Antonia de Oliveira  Ednei Luiz Antonio  Flávio André Silva  Paulo de Tarso Camillo de Carvalho  Regiane Feliciano  Amanda Yoshizaki 《Journal of sports sciences》2018,36(20):2349-2357

We investigated whether low-level laser therapy (LLLT) prior to or post resistance exercise could attenuate muscle damage and inflammation. Female Wistar rats were assigned to non-LLLT or LLLT groups. An 830-nm DMC Laser Photon III was used to irradiate their hind legs with 2J, 4J, and 8J doses. Irradiations were performed prior to or post (4J) resistance exercise bouts. Resistance exercise consisted of four maximum load climbs. The load work during a resistance exercise bout was similar between Control (non-LLLT, 225 ± 10 g), 2J (215 ± 8 g), 4J (210 ± 9 g), and 8J (226 ± 9 g) groups. Prior LLLT did not induce climbing performance improvement, but exposure to 4J irradiation resulted in lower blood lactate levels post-exercise. The 4J dose decreased creatine kinase and lactic dehydrogenase levels post-exercise regardless of the time of application. Moreover, 4-J irradiation exposure significantly attenuated tumor necrosis factor alpha, interleukin-6, interleukin-1β, cytokine-induced neutrophil chemoattractant-1, and monocyte chemoattractant protein-1. There was minor macrophage muscle infiltration in 4J-exposed rats. These data indicate that LLLT prior to or post resistance exercise can reduce muscle damage and inflammation, resulting in muscle recovery improvement. We attempted to determine an ideal LLLT dose for suitable results, wherein 4J irradiation exposure showed a significant protective role.  相似文献   

Effects of an unsupervised pedometer-based physical activity program on daily steps of adults with moderate to severe asthma: a randomized controlled trial     

Cristina Martins Coelho  Maycon Moura Reboredo  Felipe Martins Valle  Carla Malaguti  Larissa Almeida Campos  Lucas Mendes Nascimento 《Journal of sports sciences》2018,36(10):1186-1193

Supervised exercise has shown benefits for subjects with asthma, but little is known about the effectiveness of unsupervised physical activity on this population. We investigated the effects of a 12-week unsupervised pedometer-based physical activity program on daily steps and on clinical and psychological parameters of adults with asthma. Clinically stable adults with moderate to severe asthma were encouraged to take daily 30-minute walks and were randomized to pedometer and control groups. The pedometer group received pedometers and individualized daily step targets. Changes in daily steps (average of steps taken during six consecutive days), six-minute walk test (6MWT), health-related quality of life, asthma control and anxiety and depression levels were assessed 12 weeks after intervention and 24–28 weeks after randomization. Thirty-seven participants were recruited and 30 completed the intervention. At 12 weeks, the groups differed significantly in daily steps (adjusted average difference, 2488 steps; 95% confidence interval [CI], 803 to 4172; p = 0.005) and in the 6MWT (adjusted average difference, 21.9 m; 95% CI, 6.6 to 37.3; p = 0.006). These differences were not significant 24–28 weeks after randomization. The program was effective in increasing daily steps of adults with moderate to severe asthma 12 weeks after intervention.  相似文献