The Development of a Predictive Theory of Science Education Based Upon Information Processing Theory

This thesis describes the establishment of a new predictive theory for science education which can give direction to the improvement and transformation of science teaching at all levels. It is based upon Information Processing Theory. It has the ability to predict performance in science on the basis of independent psychological tests and to provide a framework for understanding how scientific learning takes place. The development of the theory has resulted from empirical work on 529 school pupils at "0" Grade (age 16) and on 440 Glasgow University students, through two series of experiments in addition to two confirmatory studies in the U.S.A. and Egypt. The first series related to students performance in individual questions, and the second related to students over-all performance in conventional examinations. Throughout this empirical work, a constant pattern has emerged showing that the students' holding-thinking space limited their ability to solve problems of different complexity. As soon as there was an overload on students' holding-thinking space, their performance fell away. In addition, the students' holding-thinking space is considered to be a good predictor for success in the conventional "0" Grade examinations, as well as the university examinations not only in chemistry, but also in physics, biology and mathematics. Where the theory and the empirical measurements have not agreed exactly, further investigation has been done to examine the disparities. In some cases new understanding has occurred which has allowed the theory to be modified. This thesis illustrates the importance of the teaching of learning strategies. In fact, it raises the teaching of strategies on to a par with the teaching of content. Three ways of successfully reducing the load on the students' holding-thinking space have been described and tested. The effect of the limitation of students' perceptual fields and of holding-thinking space on learning and problem solving tasks is also explored. The theory, which has been established in this thesis, answered some of the questions that educators have concerning students' limitations in learning and in problem solving. The outworking of this theory in terms of instructional methods, design of computer programs, books and laboratory experiences, is forming the basis of several follow-up studies

Epidemiologic characteristics of Klebsiella pneumoniae isolates in ventilator-associated pneumonia in intensive care units

Klebsiella pneumoniae is a common pathogen that causes ventilator associated pneumonia (VAP) in intensive care units (ICUs). Strain typing is a useful tool in tracking the spread of these infections. Primary objective was to study different strains causing VAP in Anesthesia ICUs. Secondary objective was to determine role of health-care workers (HCWs) and ICU environment in the transmission of these strains. Endotracheal aspirates of 60 VAP patients, surveillance samples from the HCWs (18 )and the ICU environment (193)were collected. Antibiogram typing and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) were used for comparison of the isolates from VAP patients and surveillance samples. Antibiogram showed 5 antibiotic susceptibility patterns that were designated A1-A5. ERIC-PCR yielded 1 to 5 amplification bands. All the isolates were typable by ERIC-PCR. Eight ERIC patterns were obtained ERIC(I)-ERIC(VIII). ERIC-PCR typing method gave higher discriminatory index (D) (0.7557) than antibiogram (0.6035). There was sharing of certain ERIC patterns among patient and HCWs or environmental sources. In Conclusion: K.pneumoniae is the most dominant pathogen in anesthesia ICUs. Throats and hands of HCWs are possible sources of pathogen transmission to patients. Surfaces with hand contact of the medical staff are often contaminated and may serve as vectors for cross transmission.Keywords: Ventilator-associated pneumonia, ICU environment, health-care workers, Klebsiella pneumoniae, antibiogram typing, ERIC-PC

Effect of different seeding methods on green manure biomass, soil properties and rice yield in rice-based cropping systems

The cultivation of green manure crops plays an important role in soil quality and the sustainability of agricultural systems. Field experiments were conducted during one season (2007/2008) to evaluate the effects of different seeding methods on the biomass and N production of hairy vetch (Vicia villosa) and barley (Hordeum vuglare). The effects of treatments on rice yield and its components were also investigated. Specifically, the following four treatments were evaluated: broadcasting before rice harvesting (BBRH), partial tillage seeding (PTS), group seeding (GS) and drill seeding (DS). The overall results showed the following ranking of biomass and nitrogen production of hairy vetch by different seeding methods: BBRH > PTS > DS > GS. Additionally, biomass and nitrogen production of barley was lower than those of hairy vetch at all tested seeding treatments. BBRH and PTS treatments led to an increase in soil bulk density, porosity and soil organic content. The application of green manure with BBRH and PTS treatments led to a significant increase in rice yield (5,330 and 5,320 kg ha-1) when compared to conventional fertilization. Based on the results, BBRH and PTS are good practices for production of green manure in paddy soil. Chemical fertilizers can be replaced with hairy vetch as green manure in rice-based cropping systems.Key words: Green manure, rice, biomass, soil property, seeding method

Prevalence of Toxigenic and Methicillin Resistant Staphylococci in Poultry Chain Production

oai:ojs.pkp.sfu.ca:article/1Staphylococci are a worldwide cause of human and animal infection and are considered to be of the most common causes of infections in birds. Enterotoxins produced by some staphylococcal species were recognized as a causative agent of staphylococcal food poisoning (SFP). Only enterotoxins produced by Staphylococcus aureus were as yet well characterized. Much less is known about enterotoxigenic potential of coagulase-negative species of genus Staphylococcus (CNS). It has been reported that enterotoxigenic CNS strains have been associated with human and animal infections and food poisoning. Samples collected from chicken production cycle (un hatched eggs, baby chicks, broilers, chicken meat and table eggs) in Luxor, Egypt were tested to investigate the presence of Staphylococcus species and detection of their enterotoxines genes with more special attention for detection of methicillin resistance gene (mec A). Samples were tested for S. aureus and CNS on the basis of cultural and biochemical properties and confirmed by PCR amplification of 16S rRNA and clfa gene. Results showed that the presence of Staphylococci were 50/150 (33.3%), 14% of the samples were S. aureus (21/150), while, 19.33% were CNS (29/150). mecA gene was detected in 66.7% and 51.7% among S. aureus and CNS respectively. Enterotoxins genes (seb, sec and see) were found in 5 (23.8%) of S. aureus with a percent of (9.5%) for seb and sec and (4.8%) for see, while sec and see were found in 6 (20.6%) of CNS.  With a percent (10.3%) for each. &nbsp

Determination and Distribution Map for Radionuclides in Soil Samples from Different Location by Gamma Spectrometry Using Software Analysis

The fundamental goal of the current study is to determine the mean activity concentrations of natural and artificial radionuclides of 226Ra, 232Th, 40K, and 137Cs using gamma spectrometry for three locations, in Egypt, Saudi Arabia, and Iraq, which are significant and vital countries in the Middle East. The mean absorbed dose rate equals 22.35, 28.96, and 43.34 nGy h-1 for Egypt, Saudi Arabia, and Iraq. The results are consistent with international reports. The dose contribution percentages for investigated locations are 24 %, 30 %, and 46 % for Egypt, Saudi Arabia, and Iraq, respectively. The obtained results were clarified by statistical measurements using one-way ANOVA test to determine the distribution and differences between the averages of the three groups under study, as they may be influenced by geological variations and human intervention. It was found that the Iraq samples followed a symmetrical, standard normal distribution, while samples from Egypt and Saudi Arabia did not. Statistically significant differences were found between the data from the three countries

Oxide Film Growth on Copper in Neutral Aqueous Solutions

The copper electrode potentials measured by the open circuit potential method in strongly aerated solutions of SO4-2, Cl-, Br-, I-, CrO4-2, CO3-2, and NO2- with difference concentrations, till steady state values are attained. The copper electrode potentials of the all experiments increase from negative to more positive values indicating oxide film growth. The copper oxide film thickness attains maximum value at low and high concentrations of each aggressive and inhibitive anions respectively. The rate of oxide film thickening is determined by use the relation: E = a + b log t, where a and b are constants. The concentration of the inhibitive anions, CrO4-2, CO3-2, and NO2- that can withstand a certain concentration of the aggressive ions, , Cl-, Br-, and I-, varies due to the relation: logC inh. = A + n logC agg., where A and n are constants. The all experiments were investigated at 25oC in all electrolytes. Keywords: Copper; oxide growth; passivity; open circuit potential

Plasma ghrelin level in children with type 1 diabetes mellitus

Background: Type-1 diabetes mellitus(T1DM) is the commonest endocrine-metabolic disease in childhood. Ghrelin is a 28-amino-acid peptide hormone secreted predominantly by P/D1 cells lining the fundus of the stomach and epsilon cells of the pancreas that stimulates appetite with lesser amounts secreted by other cells. It is not clear which factors are involved in the regulation of ghrelin secretion in children with T1DM. Objective: This study aimed to estimate the level of pre-prandial plasma ghrelin level in children with T1DM and to clarify the relationship between its level and some parameters that may affect it as BMI, serum glucose and HbA1C levels and the effect of insulin therapy on its level. Methods: This study included 88 children, 66 diabetic children with type-1 diabetes mellitus(22 new-onset diagnosed diabetic children, 22 good glycemic controlled diabetic children on regular insulin therapy and 22 poor glycemic controlled diabetic children on insulin therapy) and 22 healthy controls. Diabetic children selected from the Diabetic Clinic and Inpatient Pediatric department, Minia University hospital from April 2009 to March 2010. Their ages ranged from 4 to 10 years with a mean 8.5 ± 1.53 years. All children were subjected to history taking, clinical examination, anthropometric measurements and laboratory investigations included: Fasting and two hours post-prandial blood glucose, HbA1C , liver and renal function tests and pre-prandial plasma ghrelin level using enzyme linked immunosorbant assay (ELISA). Results: Pre-prandial plasma ghrelin levels were significantly higher in diabetic children than controls(24.4±21.4 & 9.8±3.6 pg/ml respectively, p value=0.002).Both new-onset and poorly controlled diabetic groups were significantly higher in plasma ghrelin levels (37.03±24.2 & 25.1±19.5 pg/ml, p value=0.001 & 0.001 respectively),but no significant difference between good glycemic controlled diabetic group and controls(11.09±9.6 & 9.8±3.6 pg/ml respectively, p value=0.5). Significant negative correlations were found between ghrelin level and weight, weight on centile, BMI and BMI on centile, ,fasting and 2 hours post prandial glucose levels in all diabetic children. No significant difference between males and females as regards ghrelin level was present. Conclusions: Children with T1DM had significantly higher levels of pre-prandial plasma ghrelin level. Its level increased in both of new-onset and poorly controlled diabetic children. Significant negative correlations between pre-prandial ghrelin level and weight, BMI, fasting and 2-hours post-prandial levels were present. Insulin therapy plays an important role in normalizing plasma ghrelin level in good glycemic controlled T1DM children. No significant correlation between ghrelin and HbA1C was present.Keywords: T1-DM, Ghrelin, Children, Glucose, Insulin, HbA1CEgypt J Pediatr Allergy Immunol 2011;9(2):63-7

Diagnostic and prognostic values of antikeratin antibodies (AKA) and collagen III propeptides (PIIINP) in juvenile rheumatoid arthritis

Background: The need for specific and sensitive diagnostic as well as prognostic markers for juvenile rheumatoid arthritis (JRA) has urged  scientific research toward this field.Objective: We sought to assess the diagnostic and prognostic values of serum and synovial fluid collagen III propeptides (PIIINP) and antikeratin antibodies(AKA) in JRA.Methods :Thirty-one JRA patients with a mean age of 10.6±4.2 years were enrolled in the study. They were compared to 10 SLE patients with arthritis and 15 age and sex matched healthy children as control groups. All  patients were subjected at enrollment to laboratory evaluation by CBC,  ESR, CRP, serum PIIINP and AKA. Patients with knee effusion were  subjected to AKA and PIIINP analysis in their synovial fluid samples. Clinical evaluation was done by examination of joint swelling, tenderness and limitation of movement scores. Also, radiological evaluation by plain X-ray films for hands, knees and feet using modified Larsen score (MLS) was performed. Laboratory, clinical and radiological evaluation methods were re-performed after 3 months of proper treatment. A third radiological evaluation was done one year after the first evaluation.Results: Serum PIIINP was significantly elevated in JRA patients  (12.8±8.7) ìg/L in comparison to healthy controls (7.0±1.9 ìg/L, p<0.05). However, no significant difference was observed when compared to SLE patients. Reduction of serum PIIINP was observed after 3 months of treatment with no significant difference between JRA patients (10.5±8.8 ìg/L) and the healthy controls. Synovial fluid PIIINP (56.4±6.6 ìg/L) was significantly higher than that of the serum (p<0.05). Neither serum nor synovial fluid PIIINP correlated with any of the laboratory, clinical or radiological parameters. The serum AKA positivity rate was significantly higher in JRA patients (77% at the study onset and 90% after three months) as compared to the control group (7%, p<0.001). Serum AKA values recorded a sensitivity, specificity and diagnostic efficiency in JRA patients of 77%, 93% and 83% at the study onset. These values increased after 3 months to 90%, 93% and 91% respectively. Synovial AKA levels displayed no significant difference in comparison to that of the serum.Conclusion :AKA is a specific and sensitive diagnostic marker for JRA. Meanwhile, PIIINP was significantly elevated during JRA disease activity particularly in the synovial fluid. Neither AKA nor PIIINP proved to have prognostic values in JRA.Key words: juvenile rheumatoid, arthritis, antikeratin antibodies, collagen III propeptides, SLE

Molecular Characterization of Biofilm Producing Genes in Salmonellae Isolated from Chicken

Salmonella enterica considered one of the most important food-borne pathogen. Biofilm formation considered one of the main problems related to S. enterica, in this study, biofilm formation, colony morphotype, cellulose and curli production genes of 19 Salmonella isolates were tested. The results showed that 85% of isolates produced strong biofilm and 15% of isolates produced moderate biofilm on polystyrene plate with 1/20 diluted TSB. Different colony morphotypes expressed saw, sbam, and rdar morphotype when cultivated on LB containing Congo red for monitoring cellulose and curli production. All S. enterica strains possess adrA, csgD and gcpA genes using PCR. Thus in this study all Salmonella isolates formed biofilm so they give increased tolerance for antimicrobial agents and disinfectant, which results in difficulty in the treatment of diseases and causing many problems in food industry as it becomes a persistent of source of contamination

Serum calprotectin as a diagnostic marker of late onset sepsis in full-term neonates

Background: Calprotectin, a complex of two calcium-binding proteins that belong to the S100 protein family, is abundant in the cytosolic fraction of neutrophils. A high level of calprotectin reportedly exists in extracellular fluid during various inflammatory conditions, but its role in neonatal sepsis was investigated only in one study as a marker of sepsis in very low birth weight neonates. Objective: This study aimed to measure the serum calprotectin level by ELISA in full-term neonates with late onset neonatal sepsis, its correlations with other laboratory markers of sepsis as interleukin-6, C-reactive protein (CRP), total leucocytic count and platelet count and its relation to the outcome of cases. Methods: This study comprised 48 full-term neonates with gestational ages of 37 to 42 weeks with manifestations of late onset neonatal sepsis admitted to the neonatal intensive care unit, Minia University Hospital during the period from February, 2011 to December, 2011 and 40 healthy neonates, age and sex matched as a control group. Serum levels of calprotectin, IL6 and CRP were measured for all neonates recruited in this study. Results: Serum calprotectin levels were significantly higher in term neonates with late onset neonatal sepsis than controls (3.77±1.85 μg/ml and 0.70±0.33 μg/ml respectively, P-value = 0.000). Cases with positive blood cultures and poor outcomes had the highest levels of calprotectin (5.8±0.61 μg/ml and 6.1±0.42 μg/ml respectively). Significant positive correlations were found between calprotectin levels and IL6 (P-value =0.000, r=0.92), C-reactive protein (p=0.000,r=0.95) and total leucocytic count (P-value =0.000, r=0.72), and negative correlations were found between its level and platelet count (P-value =0.000, r=-0.87), gestational age (P-value =0.014, r=-0.35) and body weight (P-value=0.018, r=-0.34). No significant differences were observed between males and females as regards calprotectin levels (3.96±2.10 μg/ml vs 3.55±1.52 μg/ml, P-value=0.444). Conclusions: Serum calprotectin levels are significantly higher in full-term neonates with late onset neonatal sepsis. Its levels correlated well with other laboratory markers of sepsis and neonatal mortality. It is a sensitive diagnostic marker for late onset neonatal sepsis.Keywords: Calprotectin, IL6, Full-term, Late-onset sepsisEgypt J Pediatr Allergy Immunol 2012;10(1):19-2