The effects of scffolding strategy in online social-collaborative learning environment on engineering students knowledge construction level: a literature review

Engineering students show very little gains in high knowledge construction level that allow them to integrate and apply real world situations especially to develop the competence and expertise in the engineering field (Streveler et al., 2008). In order to achieve the complex skills of the engineering students, scaffolding strategy needs to embark on the learning process. Scaffolding is a key strategy in cognitive apprenticeship, in which students can learn by taking increasing responsibility in complex problem solving with the guidance of more knowledgeable mentors or teachers (Collins, Brown, and Newman, 1986). This study will provide some useful insight for the scaffolding strategy used towards knowledge construction process in an online socialcollaborative learning environment. The findings of this study will clarify the scaffolding types versus knowledge construction level in online social collaborative learning environment.. The knowledge construction processes as defined by the scaffolding strategy factors will assist curricula designers or lecturers to redefine the roles and metacognitive activities of the lectures and students in order to make the learning process in the online social-collaborative learning environment more efficient, meaningful, and can improve engineering students’ knowledge construction process as well as innovative and creative thinking. The findings of this study could be used as a basis for further research in online social-collaborative learning environment

Instructional scaffolding in online social collaborative learning environment for nurturing engineering students' knowledge construction level

The purpose of this study is to evaluate the impact of Instructional Scaffolding (IS) on an online Social Collaborative Learning (SCL) environment upon engineering students' knowledge construction (KC) level. In addition., this study also investigate on how the IS cognitively steers engineering students towards KC and helps them reach a higher level of KC. This study then proposed a KC model in an online SCL environment integrated with IS that could nurture engineering students' knowledge construction level. A questionnaire, achievement test, posting scripts from Facebook discussions, and structured interviews were used for data collection. The methodology comprised two designs: a quasi-experimental for the quantitative approach, and a case study for the qualitative approach. The quasi-experimental involved the pre and post-test to be taken by 74 participants from one polytechnic in northern Malaysia to identify the improvement in their knowledge construction level. Meantime, the case study involved a process in providing the detail and depth of exploration in a real situation by obtaining the perceptions and perspectives of 10 engineering students. Content analysis and thematic analysis were used to identify the relationships between codes, themes, and between different levels of themes. A t-test indicated a significant increase in the mean score of the post-test in both of the learning environments, that is, the conventional collaborative learning (CCL) and the SCL environment supported by instructional scaffolding. Nevertheless, the engineering students in the SCL environment showed a significantly higher mean score if compared with those in the CCL environment (pre-test score; 3.05 vs post test score; 13.98). Simultaneously, comparing the combination of results in the percentage of knowledge construction level reveals that engineering students in the control group and in the experimental group demonstrated an increase for each level of knowledge construction whether they were in the CCL or in the SCL environment They illustrated different percentages for scores of argumentative knowledge construction (such as CCL=84.21 , SCL=86.11) and metacognitive knowledge construction (CCL=I3.16, SCL=64.00) between control and experimental group. Through content analysis, eight answer themes that affect engineering students' knowledge construction were identified. Nine answer themes also were identified regarding on how SCL characteristics supported by IS enabled engineering students to reach a higher level of knowledge construction. Based on all these findings, the researcher then produced a holistic knowledge construction model. It comprised the 8 essential elements of impact factors, such as students' cognitive pre-engagement, motivation, engagement and enhancement, explanation and guide, encouragement and praise, determination., comfort and engagement, as well as ease ofthe learning process in the instructional scaffolding strategy model. As a result, it is concluded that IS plays a vital role in the knowledge construction processes in order to help engineering students' construct their knowledge and reach a higher level ofthinking

Instructional scaffolding in online social collaborative learning environment for nurturing engineering students' knowledge construction level

The purpose of this study is to evaluate the impact of Instructional Scaffolding (IS) on an online Social Collaborative Learning (SCL) environment upon engineering students' knowledge construction (KC) level. In addition., this study also investigate on how the IS cognitively steers engineering students towards KC and helps them reach a higher level of KC. This study then proposed a KC model in an online SCL environment integrated with IS that could nurture engineering students' knowledge construction level. A questionnaire, achievement test, posting scripts from Facebook discussions, and structured interviews were used for data collection. The methodology comprised two designs: a quasi-experimental for the quantitative approach, and a case study for the qualitative approach. The quasi-experimental involved the pre and post-test to be taken by 74 participants from one polytechnic in northern Malaysia to identify the improvement in their knowledge construction level. Meantime, the case study involved a process in providing the detail and depth of exploration in a real situation by obtaining the perceptions and perspectives of 10 engineering students. Content analysis and thematic analysis were used to identify the relationships between codes, themes, and between different levels of themes. A t-test indicated a significant increase in the mean score of the post-test in both of the learning environments, that is, the conventional collaborative learning (CCL) and the SCL environment supported by instructional scaffolding. Nevertheless, the engineering students in the SCL environment showed a significantly higher mean score if compared with those in the CCL environment (pre-test score; 3.05 vs post test score; 13.98). Simultaneously, comparing the combination of results in the percentage of knowledge construction level reveals that engineering students in the control group and in the experimental group demonstrated an increase for each level of knowledge construction whether they were in the CCL or in the SCL environment They illustrated different percentages for scores of argumentative knowledge construction (such as CCL=84.21 , SCL=86.11) and metacognitive knowledge construction (CCL=I3.16, SCL=64.00) between control and experimental group. Through content analysis, eight answer themes that affect engineering students' knowledge construction were identified. Nine answer themes also were identified regarding on how SCL characteristics supported by IS enabled engineering students to reach a higher level of knowledge construction. Based on all these findings, the researcher then produced a holistic knowledge construction model. It comprised the 8 essential elements of impact factors, such as students' cognitive pre-engagement, motivation, engagement and enhancement, explanation and guide, encouragement and praise, determination., comfort and engagement, as well as ease ofthe learning process in the instructional scaffolding strategy model. As a result, it is concluded that IS plays a vital role in the knowledge construction processes in order to help engineering students' construct their knowledge and reach a higher level ofthinking

Vitamin D deficiency and prognostics among patients with pancreatic adenocarcinoma

BACKGROUND: The prevalence of vitamin D deficiency among patients with cancer has been previously reported. Because vitamin D is fat soluble, patients with pancreatic adenocarcinoma may have an especially high risk of vitamin D deficiency in association with ongoing and varying degrees of malabsorption. However, little is known about the correlation between vitamin D status and prognosis in these patients. METHODS: We conducted a retrospective review of vitamin D status in patients with pancreatic adenocarcinoma who were treated at Siteman Cancer Center. Patients’ demographic information, clinical staging at the time of vitamin D assessment, vitamin D levels, and survival data were collected. Vitamin D deficiency was defined as a serum 25-hydroxyvitamin D (25[OH]D) level of less than 20 ng/mL, and vitamin D insufficiency was defined as a 25(OH)D level of between 20 ng/mL and 30 ng/mL. RESULTS: Between December 2007 and June 2011, 178 patients with pancreatic adenocarcinoma had their vitamin D levels checked at the time of initial visit at this center. Of these 178 patients, 87 (49%) had vitamin D deficiency, and 44 (25%) had vitamin D insufficiency. The median 25(OH)D level was significantly lower among nonwhite patients and among patients with stage I and II disease. A 25(OH)D level of less than 20 ng/mL was found to be associated with poor prognosis (p = 0.0019) in patients with stage III and IV disease. CONCLUSIONS: Vitamin D insufficiency and deficiency were prevalent among patients with pancreatic adenocarcinoma. The vitamin D level appears to be prognostic for patients with advanced pancreatic adenocarcinoma, and its effects should be further examined in a prospective study

Properties of particleboard with oil palm trunk as core layer in comparison to three-layer rubberwood particleboard

Compaction ratio is highly dependent on the density of the wood materials used in the production of particleboard. Lower density wood materials will produce particleboard with higher compaction ratio and is believed to give better properties. The objective of this study was to evaluate the properties of threelayer particleboard made from rubberwood and oil palm trunk with different bulk density as the core layer, while the rubberwood fine particles served as surface layers for both types of particleboard. This study also investigated the effect of shelling ratios on the mechanical and physical properties of the threelayer particleboard. Melamine-fortified urea formaldehyde (UF) resin was used as the binder. The modulus of rupture (MOR), internal bond strength (IB) and thickness swelling (TS) of the particleboards were evaluated based on the Japanese Industrial Standard for particleboard (JIS A 5908:2003). The results showed that both species and shelling ratios are variables that influenced the mechanical and physical properties of the particleboard. Despite its lower compaction ratio, particleboard made from rubberwood alone had better strength properties and dimensional stability than particleboard made from a mixture of rubberwood and oil palm trunk

Pluripotent human embryonic stem cell derived neural lineages for in vitro modelling of enterovirus 71 infection and therapy

The incidence of neurological complications and fatalities associated with Hand, Foot & Mouth disease has increased over recent years, due to emergence of newly-evolved strains of Enterovirus 71 (EV71). In the search for new antiviral therapeutics against EV71, accurate and sensitive in vitro cellular models for preliminary studies of EV71 pathogenesis is an essential prerequisite, before progressing to expensive and time-consuming live animal studies and clinical trials. This study thus investigated whether neural lineages derived from pluripotent human embryonic stem cells (hESC) can fulfil this purpose. EV71 infection of hESC-derived neural stem cells (NSC) and mature neurons (MN) was carried out in vitro, in comparison with RD and SH-SY5Y cell lines. Results: Upon assessment of post-infection survivability and EV71 production by the various types, it was observed that NSC were significantly more susceptible to EV71 infection compared to MN, RD (rhabdomyosarcoma) and SHSY5Y cells, which was consistent with previous studies on mice. The SP81 peptide had significantly greater inhibitory effect on EV71 production by NSC and MN compared to the cancer-derived RD and SH-SY5Y cell lines. Hence, this study demonstrates that hESC-derived neural lineages can be utilized as in vitro models for studying EV71 pathogenesis and for screening of antiviral therapeutics

Enhanced performance in fluorene-free organometal halide perovskite light-emitting diodes using tunable, low electron affinity oxide electron injectors.

Fluorene-free perovskite light-emitting diodes (LEDs) with low turn-on voltages, higher luminance and sharp, color-pure electroluminescence are obtained by replacing the F8 electron injector with ZnO, which is directly deposited onto the CH3NH3PbBr3 perovskite using spatial atmospheric atomic layer deposition. The electron injection barrier can also be reduced by decreasing the ZnO electron affinity through Mg incorporation, leading to lower turn-on voltages.The authors would like to acknowledge funding from the Cambridge Commonwealth, European and International Trusts, Rutherford Foundation of New Zealand, A*STAR National Science Scholarship, Girton College Cambridge, Gates Cambridge Scholarship, EPSRC (Reference: EP/G060738/1), the ERC Advanced Investigator Grant, Novox, ERC-2009-adG 247276 and Cambridge Display Technology.This is the final version of the article. It was first published by Wiley at http://onlinelibrary.wiley.com/doi/10.1002/adma.201405044/abstract

Efficient light-emitting diodes based on nanocrystalline perovskite in a dielectric polymer matrix.

Electroluminescence in light-emitting devices relies on the encounter and radiative recombination of electrons and holes in the emissive layer. In organometal halide perovskite light-emitting diodes, poor film formation creates electrical shunting paths, where injected charge carriers bypass the perovskite emitter, leading to a loss in electroluminescence yield. Here, we report a solution-processing method to block electrical shunts and thereby enhance electroluminescence quantum efficiency in perovskite devices. In this method, a blend of perovskite and a polyimide precursor dielectric (PIP) is solution-deposited to form perovskite nanocrystals in a thin-film matrix of PIP. The PIP forms a pinhole-free charge-blocking layer, while still allowing the embedded perovskite crystals to form electrical contact with the electron- and hole-injection layers. This modified structure reduces nonradiative current losses and improves quantum efficiency by 2 orders of magnitude, giving an external quantum efficiency of 1.2%. This simple technique provides an alternative route to circumvent film formation problems in perovskite optoelectronics and offers the possibility of flexible and high-performance light-emitting displays.The authors acknowledge funding from the Gates Cambridge Trust, the Singapore National Research Foundation (Energy Innovation Programme Office), the KACST-Cambridge University Joint Centre of Excellence, the Royal Society/Sino-British Fellowship Trust, and the Engineering and Physical Sciences Research Council, UK. We also thank Dr. Alessandro Sepe for helpful discussions of the XRD data.This is the final version of the article. It first appeared from ACS via http://dx.doi.org/10.1021/acs.nanolett.5b0023

Size-Dependent Photon Emission from Organometal Halide Perovskite Nanocrystals Embedded in an Organic Matrix.

In recent years, organometal halide perovskite materials have attracted significant research interest in the field of optoelectronics. Here, we introduce a simple and low-temperature route for the formation of self-assembled perovskite nanocrystals in a solid organic matrix. We demonstrate that the size and photoluminescence peak of the perovskite nanocrystals can be tuned by varying the concentration of perovskite in the matrix material. The physical origin of the blue shift of the perovskite nanocrystals’ emission compared to its bulk phase is also discussed.D.D. acknowledges the Department of Physics, University of Cambridge and the KACST-Cambridge University Joint Centre of Excellence for financial support. G.L. thanks the Gates Cambridge Trust for support. Q.S. acknowledges the Imperial College Junior Research Fellowship. J.L.M.D. acknowledges ERC Advanced Investigator Grant, Novox, ERC-2009-adG247276. This work was supported by the Engineering and Physical Sciences Research Council, UK.This is the final published version. It first appeared at http://pubs.acs.org/doi/abs/10.1021/jz502615e

Bright light-emitting diodes based on organometal halide perovskite.

Solid-state light-emitting devices based on direct-bandgap semiconductors have, over the past two decades, been utilized as energy-efficient sources of lighting. However, fabrication of these devices typically relies on expensive high-temperature and high-vacuum processes, rendering them uneconomical for use in large-area displays. Here, we report high-brightness light-emitting diodes based on solution-processed organometal halide perovskites. We demonstrate electroluminescence in the near-infrared, green and red by tuning the halide compositions in the perovskite. In our infrared device, a thin 15 nm layer of CH3NH3PbI(3-x)Cl(x) perovskite emitter is sandwiched between larger-bandgap titanium dioxide (TiO2) and poly(9,9'-dioctylfluorene) (F8) layers, effectively confining electrons and holes in the perovskite layer for radiative recombination. We report an infrared radiance of 13.2 W sr(-1) m(-2) at a current density of 363 mA cm(-2), with highest external and internal quantum efficiencies of 0.76% and 3.4%, respectively. In our green light-emitting device with an ITO/PEDOT:PSS/CH3NH3PbBr3/F8/Ca/Ag structure, we achieved a luminance of 364 cd m(-2) at a current density of 123 mA cm(-2), giving external and internal quantum efficiencies of 0.1% and 0.4%, respectively. We show, using photoluminescence studies, that radiative bimolecular recombination is dominant at higher excitation densities. Hence, the quantum efficiencies of the perovskite light-emitting diodes increase at higher current densities. This demonstration of effective perovskite electroluminescence offers scope for developing this unique class of materials into efficient and colour-tunable light emitters for low-cost display, lighting and optical communication applications.This is the author accepted manuscript and will be under embargo until 3/2/15. The final version is published in Nature Nanotechnology: http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2014.149.html