Tert-butyl amine borane complex: An unusual application of a reducing agent on model molecules of cellulose based materials

The need to preserve cultural heritage on paper requires the setting up of methods and treatments that can be applied to original documents. The cellulose main degradation processes are hydrolysis and oxidation. Only the first one has been widely investigated. The Istituto Centrale per la Patologia del Libro (ICPL) focused its attention on oxidation phenomena and studied a particular class of reducing agents, namely the borane-amine complexes. During the investigation it was found that the borane tert-butylamine complex, besides being the most promising reducing agent, was also able to react with carboxylic functions. In the present study ¹H and ¹³C NMR, Pulsed field gradient NMR spectroscopy as well as Raman spectroscopy were used as analytical tools to disclose the mechanism of the interaction between the borane tert-butylamine complex and the carboxylic functions. Given the complexity of the paper/environment interactions and the subsequent degradation phenomena, we worked on simplified models based on small carbohydrate molecules in order to reproduce the behavior of degraded paper after reductive restoration. Modified D-glucose and D-cellobiose were used in this first step in order to set up the analytical methods before approaching more complex systems such as microcrystalline cellulose and paper. Our results give the experimental evidence that borane tert-butylamine complex is also able to neutralize acidic functions. This finding has important perspectives in paper restoration.     

Student teachers’ attitudes towards cooperative learning in inclusive education

European Journal of Psychology of Education - Past research points to cooperative learning as a potentially effective means of fostering the academic and social development of students in inclusive...     

Cardiac autonomic and haemodynamic recovery after a single session of aerobic exercise with and without blood flow restriction in older adults

This study investigated the autonomic and haemodynamic responses to different aerobic exercise loads, with and without blood flow restriction (BFR). In a crossover study, 21 older adults (8 males and 13 females) completed different aerobic exercise sessions: low load without BFR (LL) (40% VO_2max), low load with BFR (LL-BFR) (40% VO_2max + 50% BFR) and high load without BFR (HL) (70% VO_2max). Heart rate variability and haemodynamic responses were recorded during rest and throughout 30 min of recovery. HL reduced R–R interval, the root mean square of successive difference of R–R intervals and high frequency during 30 min of recovery at a greater magnitude compared with LL and LL-BFR. Sympathetic–vagal balance increased the values for HL during 30 min of recovery at a greater magnitude when compared with LL and LL-BFR. Post-exercise haemodynamic showed reduced values of double product at 30 min of recovery compared to rest in LL-BFR, while HL showed higher values compared to rest, LL-BFR and LL. Reduced systolic blood pressure was observed for LL-BFR (30 min) compared to rest. Autonomic and haemodynamic responses indicate lower cardiovascular stress after LL-BFR compared to HL, being this method, besides the functional adaptations, a potential choice to attenuate the cardiovascular stress after exercise in older adults.     

Does Cross-cultural Competence Matter when Going Global: Cultural Intelligence and Its Impact on Performance of International Students in Australia

Cultural Intelligence (CQ) is a critical competency in the modern world. By examining 189 international students from an Australian university, this study investigates the impact of CQ and cultural exposure on intercultural adjustment and academic performance. Significant positive relationships are found between facets of CQ and Interactional Adjustment and General Adjustment, but a significant negative relationship with Academic Performance. We also demonstrate the validity of a new construct of Cultural Exposure (CE) including three dimensions (Geographical, Environmental, and Inherited) with both Geographical and Environmental dimensions producing a strong positive correlation with Academic Performance.     

High bar swing performance in novice adults: effects of practice and talent

An individual's a priori talent can affect movement performance during learning. Also, task requirements and motor-perceptual factors are critical to the learning process. This study describes changes in high bar swing performance after a 2-month practice period. Twenty-five novice participants were divided by a priori talent level (spontaneous-talented [ST] and nonspontaneous-talented [NST]) and compared to experienced gymnasts. Additionally, we assessed their perception of their performance level before and after practice. We defined three events independently for hip (H) and shoulder (S) angle joints and for the lag between consecutive events (phases [P]): the smallest angle during downswing (P1H, P1S), the largest angle after P1 (P2H, P2S), and the smaller angle during upswing (P3H, P3S). Movement performance variables were the maximum elevation on the downswing (Pi) and the upswing (Pf), and the total path between both (swing amplitude). Data were collected during pre- and postpractice sessions by two video cameras. At the end of both sessions, participants drew a sketch to represent their perception of their performance level relative to the Pi, Pf and the hip events. Results showed a similar practice effect in the swing amplitude in both novice groups. However the ST group 's performance and perception variables on the downswing improved more than the NST group due to practice. This study suggests that (a) downswing improvements were easier than in the upswing, possibly due to familiarity of the visual reference in combination with proprioceptive feedback; and (b) being ST may involve a better orfaster gain in perception of self-action compared to NST.     

Can learning of basketball be enhanced through a web-based multimedia course? An experimental study

This study’s aim is the creation of a web-based multimedia course for Physical Education (PE) students’ familiarization with the teaching of basketball, and the evaluation of its use as a complementary tool to conventional instruction, in terms of learning effectiveness and student acceptance. The course includes multimedia learning material as well as interactive learning activities and quizzes on the cognitive components of basic basketball skills and on other basketball-related topics (history of the sport, referee’s signals, training aids, basketball court). The study involved 88 undergraduate students during one semester. They were randomly assigned to two groups: a group that used the web-based multimedia course and also attended a conventional face-to-face course on the teaching of basketball (N?=?45), and another group that only attended the conventional face-to-face course (N?=?43). A pretest/posttest research design was followed. For both groups basketball knowledge was measured at the beginning and at the end of the semester through written questionnaires. The responses of the students of the first group towards the web-based course were also assessed, at the end of the semester, through a written feedback questionnaire. Within both groups, significant increases in students’ basketball knowledge were found. However, the web-based multimedia course in combination with conventional face-to-face instruction was significantly more effective than conventional face-to-face instruction alone in increasing students’ cognitive learning regarding the sport of basketball, at the same time being well-accepted by the students. These findings support the effectiveness of blended learning for PE at higher education level as well as the acceptance of this mode of learning by PE students.     

Cross-lingual training of summarization systems using annotated corpora in a foreign language

The increasing trend of cross-border globalization and acculturation requires text summarization techniques to work equally well for multiple languages. However, only some of the automated summarization methods can be defined as “language-independent,” i.e., not based on any language-specific knowledge. Such methods can be used for multilingual summarization, defined in Mani (Automatic summarization. Natural language processing. John Benjamins Publishing Company, Amsterdam, 2001) as “processing several languages, with a summary in the same language as input”, but, their performance is usually unsatisfactory due to the exclusion of language-specific knowledge. Moreover, supervised machine learning approaches need training corpora in multiple languages that are usually unavailable for rare languages, and their creation is a very expensive and labor-intensive process. In this article, we describe cross-lingual methods for training an extractive single-document text summarizer called MUSE (MUltilingual Sentence Extractor)—a supervised approach, based on the linear optimization of a rich set of sentence ranking measures using a Genetic Algorithm. We evaluated MUSE’s performance on documents in three different languages: English, Hebrew, and Arabic using several training scenarios. The summarization quality was measured using ROUGE-1 and ROUGE-2 Recall metrics. The results of the extensive comparative analysis showed that the performance of MUSE was better than that of the best known multilingual approach (TextRank) in all three languages. Moreover, our experimental results suggest that using the same sentence ranking model across languages results in a reasonable summarization quality, while saving considerable annotation efforts for the end-user. On the other hand, using parallel corpora generated by machine translation tools may improve the performance of a MUSE model trained on a foreign language. Comparative evaluation of an alternative optimization technique—Multiple Linear Regression—justifies the use of a Genetic Algorithm.