Mathematics as personal and social activity

European Journal of Psychology of Education -     

The impact of polytechnic institutes on the local economy

Tertiary Education and Management - Higher education institutions and, particularly, polytechnic institutes in Portugal are, generally speaking, recognized as the key stakeholders in regional...     

“Did you do your homework?” Mathematics teachers’ homework follow‐up practices at middle school level

Teachers’ homework follow‐up practices, the in‐class strategies teachers use to monitor their students’ homework assignments, have an impact on their students’ homework behaviors and academic achievement. The current study explored the perspectives of middle school mathematics teachers on the three domains of homework follow‐up: the practices used in class, the purposes of each practice, and the aspects that may influence this process. Data were collected from two data sources (i.e., focus groups and classroom observations) and were analyzed using thematic analysis. The findings showed that teachers monitored homework either using a single strategy or a combination of strategies (e.g., checking homework completion and providing individual feedback) linked to a specific purpose (e.g., promote students’ involvement). The teachers also reported that they were under certain constraints when they delivered homework follow‐up practices (e.g., pressure to follow the curriculum), so their practices’ effectiveness sometimes can be compromised. Implications for practice are discussed.     

The performance of young deaf children in spatial and temporal number tasks

Deaf children tend to fall behind in mathematics at school. This problem may be a direct result of particular experiences in the classroom; for example, deaf children may find it hard to follow teachers' presentations of basic, but nevertheless quite abstract, mathematical ideas. Another possibility is that the problem starts before school: They may either be worse than hearing children at early, nonlinguistic number representations, they may be behind in learning the culturally transmitted number string, or both. This may result in deaf children failing to develop informal problem-solving strategies, which prepare most children for the more formal learning of number and arithmetic that they will have to do at school. We compared 3- and 4-year-old deaf and hearing children's ability to remember and to reproduce the number of items in a set of objects. In one condition, we presented all the items together in a spatial array; in another, we presented them one at a time in a temporal sequence. Deaf children performed as well as the hearing children in the temporal tasks, but outperformed their hearing counterparts in the spatial task. These results suggest that preschool deaf children's number representation is at least as advanced as that of hearing children, and that they are actually better than hearing children at representing the number of objects in spatial arrays. We conclude that deaf children's difficulties with mathematical learning are not a consequence of a delay in number representation. We also conclude that deaf children should benefit from mathematical instruction that emphasizes spatial representation.     

The failure of a virtual social space (VSS) designed to create a learning community: lessons learned

The disappearance of physical social spaces from today's society is seen by some to be a modern phenomenon, resulting in isolation and lack of socialisation. In fact, this is always the case in distance education, due to geographical dispersion and disparate time schedules of learners. Very often, peer‐to‐peer socialisation in distance education only occurs as part of formal learning activities, or is just left to the student's own initiative. This situation is compounded by the modularity of Virtual Learning Environments (VLEs), forcing students to jump from one module space to another as they progress through a course. All discussion threads, conversations or record of previous dialogues are then lost. This paper reports on the design, development and extensive evaluation of a Virtual Social Space (VSS) conceived to address these problems and to support the creation of a learning community for a Continuing Professional Distance Education (CPDE) Masters in IT Management. An action research approach was adopted to establish student needs, design and develop the site and to explore it with students. Initially received with enthusiasm and perceived as a good idea by the students, the VSS was not entirely successful. This paper discusses how characteristics of this cohort had an impact on students’ perception and usage of this social space to create a learning community.     

Plasma centrifugation does not influence thrombin-antithrombin and plasmin-antiplasmin levels but determines platelet microparticles count

Introduction

Centrifugation is an essential step for plasma preparation to remove residual elements in plasma, especially platelets and platelet-derived microparticles (PMPs). Our working hypothesis was that centrifugation as a preanalytical step may influence some coagulation parameters.

Materials and methods

Healthy young men were recruited (N = 17). For centrifugation, two protocols were applied: (A) the first centrifugation at 2500 x g for 15 min and (B) at 2500 x g for 20 min at room temperature with a light brake. In protocol (A), the second centrifugation was carried out at 2500 x g for 15 min, whereas in protocol (B), the second centrifugation involved a 10 min spin at 13,000 x g. Thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes concentrations were determined by enzyme-linked immunosorbent assays. PMPs were stained with CD41 antibody and annexin V, and analyzed by flow cytometry method. Procoagulant activity was assayed by the Calibrated Automated Thrombogram method as a slope of thrombin formation (CAT velocity).

Results

Median TAT and PAP concentrations did not differ between the centrifugation protocols. The high speed centrifugation reduced the median (IQR) PMP count in plasma from 1291 (841-1975) to 573 (391-1010) PMP/µL (P = 0.001), and CAT velocity from 2.01 (1.31-2.88) to 0.97 (0.82-1.73) nM/min (P = 0.049). Spearman’s rank correlation analysis showed correlation between TAT and PMPs in the protocol A plasma which was (rho = 0.52, P < 0.050) and between PMPs and CAT for protocol A (rho = 0.74, P < 0.050) and protocol B (rho = 0.78, P < 0.050).

Conclusion

Centrifugation protocols do not influence the markers of plasminogen (PAP) and thrombin (TAT) generation but they do affect the PMP count and procoagulant activity.Key words: cell-derived microparticles, blood coagulation tests, centrifugation, preanalytical phase     

The relations between children's linguistic awareness and spelling: The case of the apostrophe

In a longitudinal study, we looked at the link between children'sunderstanding of a morphemically-based orthographic rule and theirawareness of morphemic distinctions. The orthographic rule in question wasthe use of the apostrophe to denote possession in English. Early on in thestudy, we gave the children phonological, semantic/syntactic and morpho-syntactic awareness tasks, and later we gave them a spelling task in whichthey had to write words which were either genitives (e.g., `boy's') ornominative or accusative plurals (e.g., `boys'). Eight- to 10-year-oldchildren found this task difficult, but their performance improved to someextent with age. The morpho-syntactic, but not the phonological orsemantic/syntactic, awareness tasks predicted how well the children placedapostrophes in genitive words and omitted them from plural words. Weconclude that different forms of linguistic awareness affect differentaspects of reading and spelling. Learning about spelling patterns based onmorphemes is heavily influenced by children's morpho-syntactic awarenessbut not, apparently, by other forms of linguistic awareness.     

The signed algorithm and its bugs

Deaf children consistently lag behind their hearing cohorts in mathematics achievement tests. It has been hypothesized that their difficulty is a consequence of their lack of covert counting strategies and reliance on memorized verbal facts. We investigated the acquisition of an alternative method to solve sums, the signed algorithm, by six profoundly deaf primary school children. Similarly to the acquisition of the written algorithm by hearing children, deaf children's calculation errors with the signed algorithm were found to be systematic and related to the structure of the numeration system in British Sign Language. These results can be used to examine better ways of teaching arithmetic to deaf children and illustrate in a novel way the role of systems of signs in mathematical cognition.     

Physiological Correlations With Short,Medium, and Long Cycling Time-Trial Performance

Purpose: Several studies have demonstrated that physiological variables predict cycling endurance performance. However, it is still unclear whether the predictors will change over different performance durations. The aim of this study was to assess the correlations between physiological variables and cycling time trials with different durations. Methods: Twenty trained male cyclists (maximal oxygen uptake [VO₂max] = 60.5 ± 5.6 mL/kg/min) performed 4 separate experimental trials during a 2-week period. Cyclists initially completed an incremental exercise test until volitional exhaustion followed by 3 maximal cycling time trials on separate days. Each time trial consisted of 3 different durations: 5 min, 20 min, and 60 min performed in a randomized order. Results: The main results showed that the physiological measures strongly correlated with long cycling performances rather than short and medium time trials. The time-trial mean power output was moderately high to highly correlated with peak power output and VO_2max (r = .61–.87, r = .72–.89, respectively), and was moderately to highly correlated with the lactate threshold Dmax method and second ventilatory threshold (r = .52–.75, r = .55–.82, respectively). Conclusions: Therefore, trained cyclists should develop maximal aerobic power irrespective of the duration of time trial, as well as enhancements in metabolic thresholds for long-duration time trials.