Investigating the effectiveness of a POE-based teaching activity on students’ understanding of condensation

Cataloged from PDF version of article.This article reports on the development of a Predict–Observe–Explain, POEbased teaching strategy to facilitate conceptual change and its effectiveness on student understanding of condensation. The sample consisted of 52 first-year students in primary science education department. Students’ ideas were elicited using a test consisting of five probe questions and semi-structured interviews. A teaching activity composed of three Predict–Discuss–Explain–Observe–Discuss–Explain (PDEODE) tasks was employed, based on students’ preconceptions identified with the test. Conceptual change in students’ understanding of condensation was evaluated via a pre-, post-, and delayed post-test approach and students’ interviews. Test scores were analyzed using both qualitative and quantitative methods. The findings suggested that the strategy helps students to achieve better conceptual understanding for the concept of condensation and enables students to retain these new conceptions in their long-term memory

The Vehicle Routing Problem with Divisible Deliveries and Pickups

The vehicle routing problem with divisible deliveries and pickups is a new and interesting model within reverse logistics. Each customer may have a pickup and delivery demand that have to be served with capacitated vehicles. The pickup and the delivery quantities may be served, if beneficial, in two separate visits. The model is placed in the context of other delivery and pickup problems and formulated as a mixed-integer linear programming problem. In this paper, we study the savings that can be achieved by allowing the pickup and delivery quantities to be served separately with respect to the case where the quantities have to be served simultaneously. Both exact and heuristic results are analysed in depth for a better understanding of the problem structure and an average estimation of the savings due to the possibility of serving pickup and delivery quantities separately

DISTINCT PHENOTYPIC CHANGES BY PACAP AND VIP IN LIPOPOLYSACCHARIDE STIMULATED BV2 MICROGLIAL CELLS

Background: Aberrant microglial activation plays a key role in the progressive neuronal loss seen in many neurodegenerative diseases. PACAP and VIP are two neuropeptides that elicit robust immunosuppressive functions within the CNS. However, the underlying mechanisms through which these peptides regulate microglia activities are not clear. Aim & Objectives: Using lipopolysaccharide (LPS) to induce BV2 microglial cell polarisation, we aimed at testing whether and how administration of either PACAP or VIP could differentially affect microglial pro-inflammatory profile, polarisation state and morphological appearance to elicit immunosuppressive effects. Methods: Quantitative real-time PCR, Western blot, Griess reactions, immunofluorescence and morphological analyses were conducted in order to determine the effects of PACAP and VIP in BV2 microglial cells exposed or not to 1µg/ml LPS. Results: Our data demonstrated that both PACAP and VIP reduce the expression of pro-inflammatory mediators in LPS-stimulated BV2 cells. We also found that exogenous administration of PACAP and VIP rescued the dysregulations of the endogenous PACAP/VIP levels and attenuated the expression of microglial activation markers caused by LPS. Interestingly, despite the similar anti-inflammatory activities of PACAP and VIP, PACAP mainly reduced the number of M1 polarised cells, whereas VIP acted by increasing the subpopulation of cells exhibiting an ‘intermediate’ phenotype/bipolar-shaped (p<0.001 vs. control), at the expenses of resting/rounded cells. Conclusion: PACAP and VIP both possess immunosuppressive effects in activated BV2 microglial cells, but these effects seem to involve the differential shift of certain cell subpopulations towards distinctive phenotypes

FUTURE CARDIAC EVENTS IN NORMALLY DIAGNOSED GATED MYOCARDIAL PERFUSION SPECT (GSPECT)

Coronary heart disease (CHD) is a major cause of mortality and morbidity in Europe and USA and its management consumes a large proportion of national healthcare budgets. Many studies had tested the prognostic value of a normal myocardial perfusion scintigraphy; they concluded that a normal MPI study is associated with a very low rate of future cardiac events. In view of the above this study is designed to determine the risk of future cardiac events after normal MPS in local population. Methods: This was a retrospective observational registry performed in a single center in the Kingdom of Saudi Arabia. The data were collected from the nuclear medicine database identifying all the reported normal myocardial perfusion scans between January 2008 and December 2011 . Results: There were 290 patients identified with normal cardiac nuclear scans in the pre-specified time frame. Basic patient demographics were outlined and the patients’ charts were reviewed looking for any major cardiac events such as MI or sudden death. Mean follow up was 14.8 months. There were 2 patients that were admitted with NSTEMI and went on to have diagnostic angiograms. One of those two patients underwent percutaneous coronary intervention with stenting. The other patient had nonobstructive CAD and was advised for medical management only. These findings are consistent with a 0.7% risk of cardiac events after a negative scan Conclusion: The above findings demonstrate that the risk of major cardiac events after a negative nuclear cardiac scan is low and is in keeping with the international statistics available

FUTURE CARDIAC EVENTS IN NORMALLY DIAGNOSED GATED MYOCARDIAL PERFUSION SPECT (GSPECT)

Coronary heart disease (CHD) is a major cause of mortality and morbidity in Europe and USA and its management consumes a large proportion of national healthcare budgets. Many studies had tested the prognostic value of a normal myocardial perfusion scintigraphy; they concluded that a normal MPI study is associated with a very low rate of future cardiac events. In view of the above this study is designed to determine the risk of future cardiac events after normal MPS in local population. Methods: This was a retrospective observational registry performed in a single center in the Kingdom of Saudi Arabia. The data were collected from the nuclear medicine database identifying all the reported normal myocardial perfusion scans between January 2008 and December 2011 . Results: There were 290 patients identified with normal cardiac nuclear scans in the pre-specified time frame. Basic patient demographics were outlined and the patients’ charts were reviewed looking for any major cardiac events such as MI or sudden death. Mean follow up was 14.8 months. There were 2 patients that were admitted with NSTEMI and went on to have diagnostic angiograms. One of those two patients underwent percutaneous coronary intervention with stenting. The other patient had nonobstructive CAD and was advised for medical management only. These findings are consistent with a 0.7% risk of cardiac events after a negative scan Conclusion: The above findings demonstrate that the risk of major cardiac events after a negative nuclear cardiac scan is low and is in keeping with the international statistics available

Commercial cultivation by farmers of medicinal plants in Northern Bangladesh

Medicinal plants (MPs) are an important component of non-timber forest products (NTFPs), which are traditionally used in healthcare and source of livelihood all over the world. In an over-populated country like Bangladesh, the pressure on natural forests is immense; thus the cultivation of MPs can significantly contribute towards improving the livelihood of poor people, reducing the pressure on natural forests and enhancing biological diversity. Notwithstanding the growing recognition of its importance and economic and ecological potential, there has been little research on MPs, especially the cultivation, management and marketing aspects, in Bangladesh. Based on extensive fieldwork in a northern district of Bangladesh, this study explores various aspects of the cultivation, management and marketing of MPs. How collective efforts have brought economic and social benefits to communities was also examined in this study. It assesses the major processes and elements of management, identifies key problems and challenges and indicates ways of maximizing the potential of this important sector. The issues covered in this research include: farmers ’ perceptions and experiences; existing research and policy-making processes related to the MP sector; constraining factors (such as lack of processing technology, inadequate transportation, logistics, financial and storage infrastructure, lack of institutional capacity); markets, finance and networking; land use; pattern of livelihood and value chain issue

Does currency wealth or substitiution effect matters? recent evidence from money demand in China

This study investigates the stability of money demand function for China, using an innovation ARDL framework for co-integration test for the time period 1986-2018. Specifically, this study used narrow money (M1) and broad money (M2) as a measurement of money. To consider currency wealth and substitution effects, the estimated money demand model includes the real effective exchange rate in addition to income and interest rate. By incorporating the CUSUM and CUSUMSQ tests for stability in conjunction with co-integration analysis, the results confirm that there exists a stable long-run relationship for narrow money demand function. Importantly, the finding also discovers that real effective exchange rate appears to have a significant substitution effect on narrow money demand, which its omission can lead to biased result and misspecifications in the money demand function. This further corroborates that narrow money, (M1) act as a better measurement, which may have systematic influence on the trend of monetary aggregates

Kinetic and thermodynamic study of oxidative degradation of acid yellow 17 dye by Fenton-like process: Effect of HCO3−, CO32−, Cl− and SO42− on dye degradation

We report here the degradation of AY-17 dye using Fenton-like process (H2O2/Fe3+). The maximum degradation (83%) of AY17 dye is achieved at pH 3 in 60 min, with optimum concentrations of AY 17 (0.06 mM), H2O2 (0.9 mM), and Fe2+ (0.06 mM). The scavenging effects of HCO3−, CO32−, Cl− and SO42− on dye degradation are also examined. The activation energy (Ea), activation enthalpy (rH*), and activation entropy (rS*) are calculated for the dye degradation using pseudo-first-order kinetics at various temperature.               KEY WORDS: Acid Yellow 17, H2O2/Fe3+, Fenton-like process, Oxidative degradation, Scavenging effects Bull. Chem. Soc. Ethiop. 2019, 33(2), 243-254.DOI: https://dx.doi.org/10.4314/bcse.v33i2.

BORON STATUS OF SOILS AS AFFECTED BY DIFFERENT SOIL CHARACTERISTICS-pH, CaCO 3 , ORGANIC MATTER AND CLAY CONTENTS

In Pakistan, the soils are mostly developed from calcareous, alluvial and loessial deposits of late Pleistocene age located partially on old river terrace and relatively on the channel-levee-remnants, therefore micronutrients instigate from weathering of rock parent materials and their deficiencies are wide spread because of intensive cultivation and more nutrient uptake than application. This study was started to determine the authentic information about boron status of calcareous soils having alkaline pH and low organic matter (OM) contents under canal and tube well irrigated areas of Punjab. Soil samples were collected from eighty one sites of five districts of Punjab. Soil samples were analyzed for pHs, texture, ECe, total N, Extractable K, Olsen P, CaCO 3 , OM and 0.05 M HCl extractable B. The textural analysis exhibited that 28 % area had more clay contents and was classified as heavy textured, 42 % had loamy texture while 30 % had sandy or light textured. The results revealed that more B was observed in clay textured soils. In case of pH, 83 % area (68 sites) had pH ≥ 8.00 while 13 sites had pH ranged from 7.50 to 8.00 and only one site has pH &lt; 7.50. Incredibly low OM was observed in surveyed area and it was &lt;1 % in all the 81 samples (100 % area was low in OM). Similarly CaCO 3 contents were in the range of 2.14 to 9.72 % and about 92 % area surveyed had CaCO 3 contents in the range of 3-10 %. The data regarding B concentration in soil reflected an atrocious depiction of B deficiency in the surveyed soils and exhibited that out of 81 samples, 66 sites (82 %) had B concentration in the range of 0.10 to 0.45 μg g -1 and were fall in the deficient range (i.e. &lt;0.50 the critical level) while 12 sites (15 %) having B concentration in the range of 0.46 to 0.55 μg g -1 and only 3 samples had B range 0.56-0.91 μg g -1 . Correlation analysis exhibited that soil B is positively correlated with OM and clay content of soil while it had strong negative correlation with CaCO 3 content and pH