What Happens in Project-based Learning?

There is an accumulating literature over the last decade on collaborative learning in various types of settings, from more focussed learning tasks to open enquiry to problem-based projects. Project-based teamwork was valued as students were required to work together for knowledge sharing, knowledge building and problem-solving, and thus provide them with opportunities to be acculturated as members of a knowledge community. Over the last couple of years, it has also become extremely popular in Hong Kong schools to assign group projects to students. This was often justified on the grounds that project work promotes the information retrieval and self-directed learning abilities of students; collaborative learning is good and students should learn to collaborate with each other. However, as a pedagogical strategy, very little is known about the actual impact of group projects on learning in Hong Kong and whether the assumed advantages and expected learning outcomes do come about. Is group-based projects the panacea for the evils of teacher-centred delivery? This paper explores the question “what happens in project-based learning?” based on the observations made during the SLITS (Self-directed Learning with Information Technology Scheme) project. The project involved 40 groups of students working on projects of their own choice, each group being facilitated by a teacher. There were several key findings from this study: 1. Participation in such a project may not necessarily lead to deep learning; 2. Learning to collaborate in a group is in itself an important part of the problem-solving process; 3. There are different models of collaboration and only those models which engage the students continuously in interactive decision making during the learning process would lead to collaborative knowledge building; 4. Effective collaboration is in itself crucial for sustaining motivation and interest in the learning process; and 5. Facilitation is required for guiding both the collaborative as well as the enquiry processes. This paper will report on these findings as well as describe the key features of good collaboration and good facilitation identified through the study.published_or_final_versionCentre for Information Technology in Education, University of Hong Kon

Credibility of Various Indices of Sacrum in Identification of Sex of Sacrum

Background: Determination of sex from skeletal remains is of paramount importance for Forensic Experts for identification of the deceased. The task becomes more difficult when only a single bone is available. Though most bones exhibit clear cut sexual variation in morphology but to determine sex with 100% accuracy, one has to use metric measurements to study various indices. These indices exhibit significant variation in range according ethnicity & geographic location, hence is suggested to arrive at Demarking Point (D.P.) for these parameters which greatly help in sexing of a bone. Sacrum has been considered amongst ideal bones to determine sex of individual because of its functional morphological variation in both sexes by virtue of its contribution to pelvis. Numerous indices have been reported to determine sex of sacra but of it none have proved to effectively & singularly differentiate sex. Hence is advised to not rely on a single index but use maximum possible indices to determine sex of sacrum. Also to be taken in consideration is fact that values of these indices so is their D.P. varies according to geographical location. Hence studies such as this are carried out to calculate anthrometric data regarding various measurements & indices for a particular region. Method: 150 sacra of known sex from Tamil Nadu of South India were studied for metrical parameters for determination of sex. Efforts were made to find Demarking point for each parameter and then compared with similar studies. Results: It was evident from present study that sacral index is the most important parameter as far as the sex determination of sacrum is concerned as it could singularly identify 56% male and 78% female bones. Sacral index for population under study was observed to be 99.21 for males and 119.94 for females. Conclusion: The present study highlight importance of certain parameters like sacral index while also demonstrating insignificance other parameters, but basic fact remains that as far as the sex determination of sacrum is concerned no single parameter could identify sex in 100% of the bones and hence, it can be concluded that for sex determination of the sacrum with 100% accuracy is possible only when maximum number of parameters are taken into consideration

Determinants of the Current Account in the Eu and PIIGS

This paper investigates the relationship between current account balance and national savings, investment, budget deficit, and real exchange rate. These determinants of the current account are studied empirically by applying the Generalized Method of Moments for a sample of 24 European countries. The sample data are divided into three different groups, PIIGS, EU-PIIGS, and EU in order to study the group-specific estimations. The main result of the paper is that the determinants of our model are capable of accurately explaining past movements in current accounts for all selected groups. Additionally, current account determinants in the economically weak members, PIIGS, behave slightly differently from the rest of the EU

Nonlinearity in a dynamo

Using a rotating flat layer heated from below as an example, we consider effects which lead to stabilizing an exponentially growing magnetic field in magnetostrophic convection in transition from the kinematic dynamo to the full non-linear dynamo. We present estimates of the energy redistribution over the spectrum and helicity quenching by the magnetic field. We also study the alignment of the velocity and magnetic fields. These regimes are similar to those in planetary dynamo simulations.Comment: Accepted to Geophys. Astrophys. Fluid Dyna

A Three-Wave Longitudinal Test of Self-Determination Theory's Mediation Model of Engagement and Disaffection in Youth Sport.

Research adopting self-determination theory (SDT) supports a mediation model whereby coach motivational styles (autonomy support and interpersonal control) predict athletes' engagement and disaffection in youth sport via the satisfaction and frustration of psychological needs (autonomy, competence, and relatedness). Our study extends this research by examining SDT's mediation model longitudinally with three waves of data. Two hundred fifty-two youth sports participants (Mage = 12.98; SD = 1.84; range = 11-17; female n = 67) completed measures of study variables at the start, middle, and end of a competitive soccer season. Cross-lagged path analyses revealed that associations between the two coach motivational styles and athletes' engagement were mediated by psychological need satisfaction. Furthermore, a positive reciprocal association between psychological need satisfaction and engagement emerged over time. This study therefore supports the temporal assumptions underpinning SDT's mediation model but, importantly, evidences a mutually reinforcing interplay between athletes' psychological needs and their engaged behavior

Phosphorylation of the androgen receptor is associated with reduced survival in hormonerefractory prostate cancer patients

Cell line studies demonstrate that the PI3K/Akt pathway is upregulated in hormone-refractory prostate cancer (HRPC) and can result in phosphorylation of the androgen receptor (AR). The current study therefore aims to establish if this has relevance to the development of clinical HRPC. Immunohistochemistry was employed to investigate the expression and phosphorylation status of Akt and AR in matched hormone-sensitive and -refractory prostate cancer tumours from 68 patients. In the hormone-refractory tissue, only phosphorylated AR (pAR) was associated with shorter time to death from relapse (<i>P</i>=0.003). However, when an increase in expression in the transition from hormone-sensitive to -refractory prostate cancer was investigated, an increase in expression of PI3K was associated with decreased time to biochemical relapse (<i>P</i>=0.014), and an increase in expression of pAkt<sup>473</sup> and pAR<sup>210</sup> were associated with decreased disease-specific survival (<i>P</i>=0.0019 and 0.0015, respectively). Protein expression of pAkt<sup>473</sup> and pAR<sup>210</sup> also strongly correlated (<i>P</i><0.001, c.c.=0.711) in the hormone-refractory prostate tumours. These results provide evidence using clinical specimens, that upregulation of the PI3K/Akt pathway is associated with phosphorylation of the AR during development of HRPC, suggesting that this pathway could be a potential therapeutic target

Defect-free outer-selective hollow fiber thin-film composite membranes for forward osmosis applications

© 2019 Elsevier B.V. This study presents the successful fabrication of a novel defect-free outer-selective hollow fiber (OSHF) thin-film composite (TFC) membrane for forward osmosis (FO) applications. Thin and porous FO membrane substrates made of polyether sulfone (PES) with a dense and smooth outer surface were initially fabricated at different air-gap distances. A modified vacuum-assisted interfacial polymerization (VAIP) technique was then successfully utilised for coating polyamide (PA) layer on the hollow fiber (HF) membrane substrate to prepare OSHF TFC membranes. Experimental results showed that the molecular weight cut-off (MWCO) of the surface of the membrane substrate should be less than 88 kDa with smooth surface roughness to obtain a defect-free PA layer via VAIP. The FO test results showed that the newly developed OSHF TFC membranes achieved water flux of 30.2 L m−2 h−1 and a specific reverse solute flux of 0.13 g L−1 using 1 M NaCl and DI water as draw and feed solution, respectively. This is a significant improvement on commercial FO membranes. Moreover, this OSHF TFC FO membrane demonstrated higher fouling resistance and better cleaning efficiency against alginate-silica fouling. This membrane also has a strong potential for scale-up for use in larger applications. It also has strong promise for various FO applications such as osmotic membrane bioreactor (OMBR) and fertilizer-drawn OMBR processes

Observations of Reduced Electron Gyroscale Fluctuations in National Spherical Torus Experiment H-Mode Plasmas with Large E X B Flow Shear

Electron gyroscale fluctuation measurements in National Spherical Torus Experiment H-mode plasmas with large toroidal rotation reveal fluctuations consistent with electron temperature gradient (ETG) turbulence. Large toroidal rotation in National Spherical Torus Experiment plasmas with neutral beam injection generates ExB flow shear rates comparable to ETG linear growth rates. Enhanced fluctuations occur when the electron temperature gradient is marginally stable with respect to the ETG linear critical gradient. Fluctuation amplitudes decrease when the ExB flow shear rate exceeds ETG linear growth rates. The observations indicate that ExB flow shear can be an effective suppression mechanism for ETG turbulence.X1129sciescopu

Design of hybrid continuous-time discrete-time delta-sigma modulators

Recent attention has been drawn to the hybrid Delta-Sigma (ΔΣ) structure featuring the integration of continuous-time (CT) and discrete-time (DT) structures in the loop filter. It combines the accurate loop filter characteristic of a DT ΔΣ modulator and the inherent anti-aliasing of a CT ΔΣ modulator. We present a design methodology for building a CT-DT ΔΣ modulator via the transformation from a DT ΔΣ modulator prototype. We also demonstrate the tradeoff of applying this structure to cascaded Delta-Sigma modulators compared to pure CT or DT implementations. ©2008 IEEE.published_or_final_versio