944 research outputs found
Applying Metacognitive Strategies in Comprehending English Reading Texts
Comprehending English text is still regarded as hard for students. Metacognitive strategies have been considered effective in overcoming reading difficulties by many researchers. The objective of this study is to describe the application of three types of metacognitive reading strategies (global strategies, problem solving strategies, and support strategies) used by the students of Senior High School (SMAN) 1 Ingin Jaya, Aceh Besar. It is a descriptive qualitative study. Metacognitive Awareness of Reading Strategies Inventory (MARSI) questionnaire suggested by Mokhtari and Reichard (2002) was used to collect the data. The result of the study revealed that the students generally showed moderate awareness of all strategies and held a preference of using Problem Solving Strategies, followed by Support Strategies and Global Strategies respectively. The study also showed that high performance students used the strategies more frequently than low performance students. It can be concluded that the more students aware of using metacognitive reading strategies, the better their performance is in reading skill. Therefore, teaching the students to use metacognitive strategies can be a solution in enhancing students’ reading ability
Three-component Synthesis of Electron-poor Alkenes using Isatin Derivatives, Acetylenic Esters, Triphenylphosphine and Theoretical Study
Synthesis of electron-poor alkenes has been reported by 1,2-proton shift and elimination of triphenyl phosphine from phosphorus ylide in good to high yields. The structures of six novel products were deduced fromtheir IR, 1HNMR, and 13CNMRspectra. The B3LYP/HF calculations for computation of 1H and 13C NMR chemical shifts have been carried out for the compounds with the 6-31G* basis set utilizing the GIAOapproach. In addition, theoretical configurations of the title compound were studied in terms of the combined analysis of the HOMO–LUMO energy gap, NBO analysis, thermodynamic parameters and molecular electrostatic potential (MEP). Also ionization potential (I), electron affinity (A), chemical hardness (ç), electronic chemical potential (μ) and electrophilicity (ù) of the title molecule are reported. All calculations were performed using B3LYP method with the 6-31G* basis set.KEYWORDS: Isatin, electron-poor alkenes, DFT, NBO, HOMO, LUMO
Quasi-periodicities of BL Lac Objects
We review the reports of possible year-long quasi-periodicities of BL Lac
objects in the -ray and optical bands, and present a homogeneous time
analysis of the light curves of PKS2155304, PG1553+113, and BL Lac. Based on
results from a survey covering the entire Fermi -ray sky we have
estimated the fraction of possible quasi-periodic BL Lac objects. We compared
the cyclical behaviour in BL Lac objects with that derived from the search of
possible optical periodicities in quasars, and find that at z1 the
cosmic density of quasi-periodic BL Lac objects is larger than that of
quasi-periodic quasars. If the BL Lac quasi-periodicities were due to a
supermassive binary black hole (SBBH) scenario, there could be a tension with
the upper limits on the gravitational wave background measured by the pulsar
timing array. The argument clearly indicates the difficulties of generally
associating quasi-periodicities of BL Lac objects with SBBHs.Comment: In publication on A&A, 6 pages, 4 figure (11 plots). Minor
corrections adde
Use of leisure time in cardiovascular patients in Gorgan (South East of Caspian Sea)
The aim of this study was to compare activity patterns and leisure time between matched groups of patients with cardiovascular disease and individuals without a heart disease. The study included 100 patients recruited from those referred to cardiology department of 5th Azar General Hospital of Golestan University of Medical Sciences in Gorgan (South East of Caspian Sea) and 100 matched control subjects during the period 2007-2008. Odds ratios (OR), together with 95% confidence intervals (95% CI), were calculated using logistic regression, as estimates of relative risks. Listening to music OR = 8.800 (95% CI: 2.717-28.499, p<0.05), meditation OR = 6.111 (95% CI; 2.616-14.274, p<0.05) were independent risk factors. Subjects who performed 2 h per week and 2-4 h per week physical activity, the odds ratios were 0.038 ( 95% CI: 0.012-0.124, p<0.05) and 0.079, (95% CI: 0.024-0.260, p<0.05), respectively. Low physical activity and use of long time relaxation are associated with cardiovascular disease in these patients. Regular participation in physical activity such as walking 2 h per week and 2-4 h per week, are associated with reduced risk of cardiovascular disease. This study suggests the importance of both leisure-time physical activity and sedentary behaviors in the prevention of CVD. © 2009 Asian Network for Scientific Information
Investigation on the Essential Oils of the Achillea Species: From Chemical Analysis to the In Silico Uptake against SARS-CoV-2 Main Protease
In this study, phytochemicals extracted from three different Achillea genera were identified and analyzed to be screened for their interactions with the SARS-CoV-2 main protease. In particular, the antiviral potential of these natural products against the SARS-CoV-2 main protease was investigated, as was their effectiveness against the SARS-CoV-1 main protease as a standard (due to its high similarity with SARS-CoV-2). These enzymes play key roles in the proliferation of viral strains in the human cytological domain. GC-MS analysis was used to identify the essential oils of the Achillea species. Chemi-informatics tools, such as AutoDock 4.2.6, SwissADME, ProTox-II, and LigPlot, were used to investigate the action of the pharmacoactive compounds against the main proteases of SARS-CoV-1 and SARS-CoV-2. Based on the binding energies of kessanyl acetate, chavibetol (m-eugenol), farnesol, and 7-epi-beta-eudesmol were localized at the active site of the coronaviruses. Furthermore, these molecules, through hydrogen bonding with the amino acid residues of the active sites of viral proteins, were found to block the progression of SARS-CoV-2. Screening and computer analysis provided us with the opportunity to consider these molecules for further preclinical studies. Furthermore, considering their low toxicity, the data may pave the way for new in vitro and in vivo research on these natural inhibitors of the main SARS-CoV-2 protease
The dynamics of the H₂+CO⁺ reaction on an interpolated potential energy surface
A potential energy surface that describes the title reaction has been constructed by interpolation of ab initio data. Classical trajectory studies on this surface show that the total reaction rate is close to that predicted by a Langevin model, although the mechanism is more complicated than simple ion-molecule capture. Only the HCO⁺ + H product is observed classically. An estimate of the magnitude of rotational inelastic scattering is also reported.financial support from the Ministry of Science,
Research and Technology of Iran, and from Shiraz University
Silica nanoparticles as a highly efficient catalyst for the one-pot synthesis of sterically congested 2-(dibenzylamino)-2-aryl acetamide derivatives from by phthaldehyde isomers, isocyanides and dibenzylamine
A green and efficient method for the preparation of 2-(dibenzylamino)-2-aryl acetamide derivatives via a three-component reaction of an isocyanide, dibenzylamine and a phthalaldehyde derivative in the presence of silica nanoparticles (silica NPs, ca. 42 nm) as a catalyst under solvent free conditions at room temperature is described. The ease of work-up, green chemistry conditions and high yields of the products make this procedure a useful addition to modern synthetic methods. The silica nanoparticles that used in this reaction as a catalyst were prepared by thermal decomposition of rice hulls. Simple, green and cheap method for the preparation of the nanocatalyst represents a major advantage for this process. The structures of these compounds were confirmed by IR, 1H and 13C NMR spectroscopy. KEY WORDS: Silica nanoparticles, Nanocatalyst, Isocyanide, Phthalaldehyde Bull. Chem. Soc. Ethiop. 2016, 30(3), 413-420DOI: http://dx.doi.org/10.4314/bcse.v30i3.
Glasgow Coma Scale and Its Components on Admission: Are They Valuable Prognostic Tools in Acute Mixed Drug Poisoning?
Introduction. The verbal, eye, and motor components of Glasgow coma scale (GCS) may be influenced by poisoned patients' behavior in an attempted suicide. So, the values of admission GCS and its components for outcomes prediction in mixed drugs poisoning were investigated. Materials and Methods. A followup study data was performed on patients with mixed drugs poisoning. Outcomes were recorded as without complications and with complications. Discrimination was evaluated by calculating the area under the receiver operating characteristic curves (AUC). Results. There was a significant difference between the mean value of each component of GCS as well as the total GCS between patients with and without complication. Discrimination was best for GCS (AUC: 0.933 ± 0.020) and verbal (0.932 ± 0.021), followed by motor (0.911 ± 0.025), then eye (0.89 ± 0.028). Conclusions. Admission GCS and its components seem to be valuable in outcome prediction of patients with mixed drug poisoning
Investigation of the quasi-free domain in deuteron-deuteron break-up using spin observables
Precision measurements of vector and tensor analyzing powers of the 2H(d, dp)n break-up process
for configurations in the vicinity of the quasi-free scattering regime with the neutron as spectator
are presented. These measurements are performed with a polarized deuteron-beam with an energy of
65MeV/nucleon impinging on a liquid-deuterium target. The experiment was conducted at the AGOR
facility at KVI using the BINA 4π-detection system. Events for which the final-state deuteron and proton
are coplanar have been analyzed and the data have been sorted for various momenta of the missing
neutron. In the limit of vanishing neutron momentum and at large deuteron-proton momentum transfer,
the data agree well with the measured and theoretically predicted spin observables of the elastic deuteronproton
scattering process. The agreement deteriorates rapidly with increasing neutron momentum and/or
decreasing momentum transfer from the deuteron beam to the outgoing proton. This study reveals the
presence of a significant contribution of final-state interactions even at very small neutron momenta
- …