Digital games pre-schoolers play: parental mediation and examination of educational content

Education and Information Technologies - The aim of this study is to examine mediations of parents who make digital games played by 60–72 months old children accessible, and the...     

A discriminant function model for admission at undergraduate university level

The study is aimed at predicting objective criteria based on a statistically tested model for admitting undergraduate students to Beirut University College. The University is faced with a dual problem of having to select only a fraction of an increasing number of applicants, and of trying to minimize the number of students placed on academic probation (currently 36 percent of new admissions). Out of 659 new students, a sample of 272 students (45 percent) were selected; these were all the students on the Dean's list and on academic probation. With academic performance as the dependent variable, the model included ten independent variables and their interactions. These variables included the type of high school, the language of instruction in high school, recommendations, sex, academic average in high school, score on the English Entrance Examination, the major in high school, and whether the major was originally applied for by the student. Discriminant analysis was used to evaluate the relative weight of the independent variables, and from the analysis three equations were developed, one for each academic division in the College. The predictive power of these equations was tested by using them to classify students not in the selected sample into successful and unsuccessful ones. Applicability of the model to other institutions of higher learning is discussed.

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Zusammenfassung In Dieser Studie wird versucht, objektive, auf einem statistisch getesteten Modell basierende Kriterien zur Zulassung von Studenten zum Beirut University College herauszufinden. Diese Hochschule muß sich mit zwei Problemen auseinandersetzen, zum ersten nur einen Teil der wachsenden Zahl von Bewerbern zulassen zu können und zum zweiten die Anzahl der Studenten auf akademischer Probezeit zu reduzieren (gegenwärtig 36% der Neuzulassungen). Von 659 neuen Studenten wurden 272 Studenten (45%) fur die Studie ausgewählt: alle vom Dekan erwählte Studenten und Studenten auf akademischer Probezeit. Das Modell beinhaltet zehn unabhängige Variablen und ihre Interaktionen und basiert auf akademischer Leistung als abhängige Variable. Unter diesen Variablen sind: die Art der Sekundarschule, die Lehrsprache an der Sekundarschule, Empfehlungen, Geschlecht, Sekundarschulnoten, Leistungen beim English Entrance Examination (Leistungstest in Englisch), das Hauptfach der Schüler und ob das Hauptfach das vom Schüler ursprünglich gewählte ist. Die statistische Analyse wurde zur Bewertung der relativen Bedeutung der unabhängigen Variablen angewandt, und es wurden drei Gleichungen aus der Analyse entwickelt; eine für jede akademische Abteilung der Hochschule. Die Gültigkeit dieser Gleichungen wurde getestet, indem man sie für die Aufteilung von nicht in die Studie einbezogenen Studenten in erfolgreiche und nicht erfolgreiche Studenten anwandte. Abschließend wird die Anwendbarkeit des Modells auf andere Einrichtungen der Höheren Bildung diskutiert.

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Résumé La présente étude vise à prédire les critères objectifs fondés sur un modèle statistiquement vérifié pour l'admission des étudiants à l'Université de Beyrouth. Cette dernière fait face à un problème dual: devoir sélectionner une fraction seulement d'un nombre croissant de candidats et essayer de minimiser le nombre d'étudiants inscrits à l'essai (soit actuellement 36 pour cent des nouvelles admissions). On a sélectionné un échantillon de 272 étudiants sur 659 nouveaux inscrits (soit 45 pour cent). Ces étudiants étaient tous ceux inscrits sur la liste du doyen ainsi que ceux inscrits à l'essai. Avec la performance scolaire comme variable dépendante, ce modèle comptait dix variables indépendantes et leurs interactions. Ces variables incluaient le type d'école supérieure, la langue d'enseignement pratiquée dans celle-ci, les recommandations, le sexe, la moyenne scolaire, la note obtenue à l'épreuve d'anglais de l'examen d'entrée, la matière principale à l'école supérieure, et indiquaient si cette matière avait été choisie par le candidat. On a utilisé F analyse discriminante pour évaluer le poids relatif des variables indépendantes. On a ensuite développé trois équations à partir de ces variables, une pour chacune des sections du collège universitaire. La force prédictive de ces équations a été testée en les employant pour classer les étudiants ne faisant pas partie de l'échantillon sélectionné en deux catégories: ceux ayant réussi et ceux ayant échoué. On discute de l'applicabilité de ce modèle à d'autres instituts d'enseignement supérieur.

     

Preliminary studies on the hypoglycaemic effect ofAbroma augusta in alloxan diabetic rats

The hypoglycemic effect of the aqueous extract ofAbroma augusta (Family: Steculiceae) was studied in normal as well as alloxan diabetic rats. Treatement of diabetic rats with 4 ml (4gm dry weight) of agueous extract ofA. augusta for 16 weeks resulted in gradual but significant fall in fasting blood glucose and improvement in glucose tolerance. Serum total and LDL cholesterol and triacylglycerol which increased in diabetic rats showed improvement. These results show that the water extract ofA. augusta has both hypoglycemic and hypocholesterolemic effects.     

Involvement of endothelial progenitor cells in the formation of plexiform lesions in broiler chickens: possible role of local immune/inflammatory response

Plexiform lesions (PLs), which are often accompanied by perivascular infiltrates of mononuclear cells, represent the hallmark lesions of pulmonary arteries in humans suffering from severe pulmonary arterial hypertension (PAH). Endothelial progenitor cells (EPCs) have been recently implicated in the formation of PLs in human patients. PLs rarely develop in rodent animal models of PAH but can develop spontaneously in broiler chickens. The aim of the present study was to confirm the presence of EPCs in the PLs in broilers. The immune mechanisms involved in EPC dysfunction were also evaluated. Lungs were collected from commercial broilers at 1 to 4 weeks of age. The right/total ventricle ratios indicated normal pulmonary arterial pressures for all sampled birds. Immunohistochemistry was performed to determine the expressions of EPC markers (CD133 and VEGFR-2) and proangiogenic molecule hepatocyte growth factor (HGF) in the lung samples. An EPC/lymphocyte co-culture system was used to investigate the functional changes of EPCs under the challenge of immune cells. PLs with different cellular composition were detected in the lungs of broilers regardless of age, and they were commonly surrounded by moderate to dense perivascular mononuclear cell infiltrates. Immunohistochemical analyses revealed the presence of CD133⁺ and VEGFR-2⁺ cells in PLs. These structures also exhibited a strong expression of HGF. Lymphocyte co-culture enhanced EPC apoptosis and completely blocked HGF-stimulated EPC survival and in vitro tube formation. Taken together, this work provides evidence for the involvement of EPCs in the development of PLs in broilers. It is suggested that the local immune cell infiltrate might serve as a contributor to EPC dysfunction by inducing EPC death and limiting their response to angiogenic stimuli. Broiler chickens may be valuable for investigating reversibility of plexogenic arteriopathy using genemodified inflammation-resistant EPCs.     

The Role of School Climate in Explaining Changes in Social Trust Over Time

School is often ranked highly among social agents that are central to the development of various citizenship values and norms in younger members of society. In this paper, we examined the impact of two dimensions of school climate on changes in social trust among adolescents over time, namely relationships and safety. Using a series of latent change models on 3-wave panel data concerning roughly 850 Swedish adolescents aged 16 to 18 years, we found that experiences of victimization in school mattered most in predicting changes in social trust across 3 time points, when relevant demographic factors and other aspects of the school climate were controlled. In particular, social trust declined most among adolescents who experienced more victimization at school.     

定量分析能源效率以及温室气体减排项目和政策中的协同效益方面的国际经验

提高能效和燃料转换效率是温室气体减排战略的一部分。过去二十年,很多研究显示这两方面带来气候变化以外的好处,多半介于这些政策方案实施成本的30%到超过100%。国际上,政策制定者对于分析能效政策和燃料转换效率政策同时纳入对温室气体和非温室气体两方面影响的探讨愈来愈感兴趣。欧盟、美国与日本已开发出一套相当成熟的方法。通常,协同效益的定量工作可分为三类:(1)协同效益模型;(2)事前的政策评估方法;(3)由学者建立的框架,意在改善这方面的研究,并将协同效益应用到更多的地区和政策方案上。 表ES-1将协同效益定量方面的几个重点模型、指南和框架做了摘要。     

Extraction of DNA suitable for PCR applications from mature leaves of Mangifera indica L.

Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary me- tabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyl- trimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950?1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation,contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple se- quence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.