Learning Preferences and Perceptions of Undergraduate Mathematics Tutees

The large number of students at postsecondary education institutions who are not college ready has increased the need for learning assistance programs. Tutoring programs are common at many such schools; however, the effect of tutoring students in modern schools is inconclusive. There is some evidence that tutoring helps students learn material they would be unable to learn otherwise, and other evidence suggests tutoring has no influence on academic performance. Considering the lack of consistent evidence to support tutoring programs, why is there still a high demand for them? The answer may include the students’ learning style and/or perception of the tutoring environment. Learning style is the way the student takes in new information or the way a student behaves in a learning experience. The learning environment includes the aesthetics and interactions within the tutoring setting. Not much is known about students who regularly seek out tutoring. The purpose of this quantitative study is to investigate correlations between the number of hours spent in tutoring, the learning styles of undergraduate mathematics students, and the perceptions these students have of their tutoring environments. This is a quantitative study investigating correlations among learning style, perception of the tutoring environment, and hours spent in tutoring. The students’ learning styles was measured using the Index of Learning Styles based on the Felder Silverman Learning Style Model. The number of hours spent in tutoring, and the perception of the tutoring environment was measured with a self-report survey. The data was coded using the Statistical Package for the Social Sciences. A principle components analysis was done on the environment measures and correlation tests were run to investigate the interaction of learning style, environment, and hours spent in tutoring

Characterization of transposon insertion mutants in desulfovibrio vulgaris hilderborough by sequencing genomic DNA [abstract]

Abstract only availableTn5 transposon mutagenesis occurs by a mechanism in which a segment of DNA (transposon) encoded in a plasmid is inserted into genomic DNA (the target) by a conservative (cut-and-paste) mechanism. When the insertion position is in a coding sequence or regulatory region of DNA, the insertion results in a mutation. The plasmid pRL27 encodes a mini-Tn5 transposon, Tn5 transposase, and kanamycin resistance, (Metcalf, William W. et al, 2002 Arch Microbiol 178 :193-201) and was used to transform Desulfovibrio vulgaris Hildenborough by electroporation. Transposon insertion mutants were identified by their ability to grow in the presence of kanamycin. To identify the insertion sites of the transposons, in theory one should be able to sequence from the transposon into chromosomal DNA and identify the mutation site by comparison with the known genome. Unlike sequencing of plasmid DNA or PCR products, direct genomic sequencing has a limited success rate. Direct genomic sequencing is sensitive to DNA quality, interference of secondary DNA structures, salt concentration, and the availability of primer binding sites. Because of these difficulties, in our attempts to identify insertion sites of mini-Tn5, we examined template DNA quality as well as modifying sequencing reaction conditions. Our objective is to develop an effective, reliable method for sequencing genomic DNA to identify where transposon insertion sites have occurred in each mutant.Department of Energy Genomics: Genomes to Life Progra

Rapid automated characterization of transposon insertion mutants in Desulfovibrio vulgaris Hildenborough by srnPCR [abstract]

Abstract only availableTn5 transposon mutagenesis occurs by a mechanism in which a segment of DNA (transposon) encoded in a plasmid is inserted into genomic DNA (the target) by a conservative (cut-and-paste) mechanism (Fig. 2). When the insertion position is in a coding sequence or regulatory region of DNA, the insertion results in a mutation. The plasmid pRL27 (a generous gift from Bill Metcalf) encodes a mini-Tn5 transposon, Tn5 transposase, and kanamycin resistance (neo), and was used to transform Desulfovibrio vulgaris Hildenborough by electroporation. Transposon insertion mutants were identified by their ability to grow in the presence of kanamycin. To locate the insertion site of the transposon, in theory, one should be able to directly sequence from the transposon into chromosomal DNA (Fig. 3.1) and identify the mutation site by comparison with the known genome BLAST. Unlike sequencing of plasmid DNA or PCR products, direct genomic sequencing has a limited success rate. Therefore, a method of enriching the transposon-flanking sequence is needed. Nested semi-random PCR (Fig. 3.2) is an efficient and cost effective enrichment method. Sequencing these enriched products allows us to identify the transposon insertion site. The factors that influence characterization success rate are: frequency and location of priming sites, reaction volume, and reaction conditions (annealing temperature, extension time, etc.). By varying these factors, we have developed an efficient and reliable method for characterizing transposon insertion mutants. Utilizing high-throughput robotics and nested semi-random PCR, we have generated single gene mutants that may provide valuable biological data.U.S. Department of Energy Genomes to Life gran

ESTIMATING THE SUBJECT BY TREATMENT INTERACTION IN NON-REPLICATED CROSSOVER DIET STUDIES

Researchers in human nutrition commonly refer to the ‘consistent’ diet effect (i.e. the main effect of diet) and an ‘inconsistent’ diet effect (i.e. a subject by diet interaction). However, due to the non-replicated designs of most studies, one can only estimate the first part using ANOVA; the latter (interaction) is confounded with the residual noise. In many diet studies, it appears that subjects do respond differently to the same diet, so the subject by diet interaction may be large. In a search of over 40,000 published human nutrition studies, most using a crossover design, we found that in none was a subject by diet interaction effect estimated. For this paper, we examined LDL-cholesterol data from a non-replicated crossover study with four diets, the typical American diet, with and without added plant sterols, and a cholesterol-lowering Step-1 diet, with and without sterols. We also examined LDL-cholesterol data from a second crossover study with some replications with three diets, representing the daily supplement of 0, 1 or 2 servings of pistachio nuts. These two data sets were chosen because experience suggested that LDLcholesterol responses to diet tend to be subject-specific. The second data set, with some replication, allowed us to estimate the subject by diet interaction term in a traditional ANOVA framework. One approach to estimating an interaction effect in non-replicated studies is through the use of a multiplicative decomposition of the interaction (sometimes called AMMI―additive main effects, multiplicative interaction). In this type of analysis, residuals, formed after estimated main effects are subtracted from the data, are arrayed in a matrix with diets as columns and subjects as rows. A singular value decomposition of the matrix is performed and the first, or first and second, principal component(s) are used as estimates of the interaction, and can be tested for significance using approximate F-tests. Using the R gnm package, we found large and significant subject by diet interaction effects in both data sets; estimates of the interaction in the second data set were similar to interaction estimates from traditional ANOVA. Of an additional 26 dependent variables from the first and a third data set (the latter investigating the effect of mild alcohol consumption on blood variables), 19 had significant subject by diet interactions, based on the AMMI methodology. These results suggest that the subject by diet interaction is often important and should not be ignored when analyzing data obtained from non-replicated crossover designs―the AMMI methodology works well and is readily available in statistical software packages

Outcomes following colectomy for Clostridium difficile colitis

AbstractIntroductionClostridium difficile associated diarrhoea has become an important health problem in UK hospitals but surgical intervention is rarely required. There is little evidence regarding best practice for patients requiring surgical intervention. The aim of this multicentre study was to review our experience in patients requiring surgery for C. difficile colitis.MethodsPatients who underwent surgery for C. difficile colitis in 5 hospitals in Southeast England over a 7-year period (1 teaching hospital and 4 district general hospitals) were identified from histopathology databases. Data were collected regarding the presentation, indication for surgery and post-operative outcomes.Results15 patients (9 males; mean age=71 years (range 35–84 years)) underwent surgery. 46% of patients (n=7) contracted C. difficile during their hospital admission for other medical reasons and 73% of patients were initially admitted under other medical specialties. Diagnosis was only made preoperatively in 8 patients (53%). Indications for surgery were peritonitis and systemic toxicity (n=12), failure of medical management (n=2) and unresolving large bowel dilatation (n=1). 12 patients underwent total colectomy and the rest underwent segmental resection. All patients were admitted to the intensive care unit post operatively with a mean stay of 6 days. 2 patients needed a second look laparotomy. Mortality rate was 67% (n=10), with all but 1 patient dying within the 30-day mortality period. The mean length of hospital stay of survivors was 30 days (range 17–72).ConclusionsSurgical intervention for C. difficile colitis remains uncommon. Total colectomy and end ileostomy is the procedure of choice. The outlook for patients requiring surgery remains poor

Hybrid Course Design: Leading a New Direction in Learning Programming Languages

“Introduction to Computing for Engineers” is a programming course emphasizing problem solving. The lack of practice time, in addition to the algorithm-centric nature of programming, results in an inadequate comprehension of course material. In the fall of 2010, three faculty members created and implemented online activities consisting of video lecture slides, and mini on-line quizzes at Embry-Riddle Aeronautical University to give students more “hands-on” learning (rather than expecting them to absorb content through lecture). Students do online lecture study by themselves, then come to the lab to practice on the following day with the instructor and teaching assistant. In the fall of 2010, four out of ten sections were delivered using hybrid instruction. Analysis of exam results at the end of the semester showed no significant distinction between hybrid learning and traditional study. Feedback received from the students indicates that the majority of students preferred the hybrid course over the traditional course. Students who took the hybrid course during this semester are happy with their hybrid experience. These positive results encouraged faculty members to increase the number of hybrid sections to four during the spring of 2011 and the fall of 2011 semesters. The hybrid course design and course-wide assessment continued. In this paper, improvement of the online video design is introduced, and assessment results are presented. It is believed that by switching from a traditional classroom environment to a hybrid learning, student comprehension of the course content will improve, in addition to their interest and subsequent retention in engineering

Characterization of Serum Phospholipase A2 Activity in Three Diverse Species of West African Crocodiles

Secretory phospholipase A2, an enzyme that exhibits substantial immunological activity, was measured in the serum of three species of diverse West African crocodiles. Incubation of different volumes of crocodile serum with bacteria labeled with a fluorescent fatty acid in the sn-2 position of membrane lipids resulted in a volume-dependent liberation of fluorescent probe. Serum from the Nile crocodile (Crocodylus niloticus) exhibited slightly higher activity than that of the slender-snouted crocodile (Mecistops cataphractus) and the African dwarf crocodile (Osteolaemus tetraspis). Product formation was inhibited by BPB, a specific PLA2 inhibitor, confirming that the activity was a direct result of the presence of serum PLA2. Kinetic analysis showed that C. niloticus serum produced product more rapidly than M. cataphractus or O. tetraspis. Serum from all three species exhibited temperature-dependent PLA2 activities but with slightly different thermal profiles. All three crocodilian species showed high levels of activity against eight different species of bacteria

Inference of transcriptional regulation in cancers

We developed an efficient and accurate computational framework, RABIT (regression analysis with background integration), and comprehensively integrated public transcription factor (TF)-binding profiles with TCGA tumor-profiling datasets in 18 cancer types. To systematically search for cancer-associated TFs, RABIT controls the effect of tumor-confounding factors on transcriptional regulation, such as copy number alteration, DNA methylation, and TF somatic mutation. Our predicted TF regulatory activity in tumors is highly consistent with the knowledge from cancer gene databases and reveals many previously unidentified cancer-associated TFs. We also analyzed RNA-binding protein regulation in cancer and demonstrated that RABIT is a general platform for predicting oncogenic gene expression regulators

Antibacterial activities of bacteria isolated from the marine sponges Isodictya compressa and Higginsia bidentifera collected from Algoa Bay, South Africa

Due to the rise inmulti-drug resistant pathogens and other diseases, there is renewed interest in marine sponge endosymbionts as a rich source of natural products (NPs). The South African marine environment is rich in marine biota that remains largely unexplored and may represent an important source for the discovery of novel NPs.We first investigated the bacterial diversity associated with five South African marine sponges, whose microbial populations had not previously been investigated, and select the two sponges (Isodictya compressa and Higginsia bidentifera) with highest species richness to culture bacteria. By employing 33 different growth conditions 415 sponge-associated bacterial isolates were cultured and screened for antibacterial activity. Thirty-five isolates showed antibacterial activity, twelve of which exhibited activity against the multi-drug resistant Escherichia coli 1699, implying that some of the bioactive compounds could be novel. Genome sequencing of two of these isolates confirmed that they harbour uncharacterized biosynthetic pathways that may encode novel chemical structures.IS