Koszul binomial edge ideals

It is shown that if the binomial edge ideal of a graph $G$ defines a Koszul algebra, then $G$ must be chordal and claw free. A converse of this statement is proved for a class of chordal and claw free graphs

Synchronous and asynchronous teacher electronic feedback and learner uptake in ESL composition

We know little about how teacher feedback and student revisions are influenced when feedback is given electronically. This study contributes to a better understanding of teacher electronic feedback (TEF) in second language writing by investigating its effectiveness in face-to-face and online ESL writing classes in which TEF was offered asynchronously, as Word comments and track changes in electronic drafts, as well as in synchronous text chats between teachers and students. TEF was extracted from 93 drafts written by 64 students and 93 chats in which they conferenced with their teachers. Students’ perceptions about TEF were then solicited via a survey. Additionally, the three participating teachers were interviewed about their use of TEF. Findings show that most TEF was successfully implemented or attempted, and that it was focused on content. Important conclusions are that TEF is effective, and synchronous TEF effectively reinforces asynchronous TEF

Impact of Microfinancein Promoting Financial Inclusion in Nigeria

Despite the Central Bank of Nigeria’s (CBN) initiatives to encourage banks to extend their services and facilities to rural areas, a high percentage of the rural dwellers still remain unbanked and as such, the initiatives appear not to promote financial inclusion services among the poor in Nigeria. As a result, small entrepreneurs often lack enabling financial environment to grow. The study undertakes an empirical analysis of the impact of microfinance in promoting financial inclusion in Nigeria between 1990 and 2014 using OLS regression method. Unit root test was conducted on the variables to examine their level of stationary to avoid spurious regression results. The findings showed that minimum deposit amount have a positive and significant relationship with saving. It was observed that access to microfinance minimum deposit amount has significant effect on savings account opened by rural dwellers. Microfinance interest rate was however found to have a negative and insignificant relationship with the rural dwellers loans and advances. Recommendations were made among which are that Government should facilitate microfinance branches close to the rural area, products and services accessible to a large segment of the potentially productive Nigeria population, who are currently not being served by the formal financial sector

Learner Uptake of Teacher Electronic Feedback in ESL Composition

The research on electronic feedback in second language writing is scarce, despite the increasingly frequent use of computers in ESL writing classrooms. The current study's purpose is to determine (1) what types of electronic written feedback ESL learners receive on writing that has been submitted and returned electronically, and (2) the relationship between teacher feedback and uptake. Twelve ESL students and three teachers participated in this longitudinal study. Multiple drafts of two essays from two semesters of college-level first-year composition were analyzed. The findings show that most of the teachers' electronic feedback consisted of marginal comments that were, for the most part, directive, explicit, principled, systematic, and needs-based – much like handwritten feedback. Importantly, electronic feedback was successful at eliciting appropriate revisions of grammatical structures or surface-level features, but also content and organization. This suggests that electronic feedback can be effective and therefore should not be avoided

Lessons from the Congested Clique Applied to MapReduce

The main results of this paper are (I) a simulation algorithm which, under quite general constraints, transforms algorithms running on the Congested Clique into algorithms running in the MapReduce model, and (II) a distributed $O(\Delta)$-coloring algorithm running on the Congested Clique which has an expected running time of (i) $O(1)$ rounds, if $\Delta \geq \Theta(\log^4 n)$; and (ii) $O(\log \log n)$ rounds otherwise. Applying the simulation theorem to the Congested-Clique $O(\Delta)$-coloring algorithm yields an $O(1)$-round $O(\Delta)$-coloring algorithm in the MapReduce model. Our simulation algorithm illustrates a natural correspondence between per-node bandwidth in the Congested Clique model and memory per machine in the MapReduce model. In the Congested Clique (and more generally, any network in the $\mathcal{CONGEST}$ model), the major impediment to constructing fast algorithms is the $O(\log n)$ restriction on message sizes. Similarly, in the MapReduce model, the combined restrictions on memory per machine and total system memory have a dominant effect on algorithm design. In showing a fairly general simulation algorithm, we highlight the similarities and differences between these models.Comment: 15 page

Selection of maize genotypes resistant to pink stem borer and sugarcane borer.

Maize is an important economic crop grown in Nigeria. Its production is dramatically affect by the pink stem borer—Sesamia calamistis (Hampson, Noctuidae) and sugarcane borer—Eldana saccharina (Walker, Pyralidae) that are endemic in Southeastern Nigeria. In areas of stress, existing genotypes may marginally do well due to their inherent capabilities. Therefore, it is possible to find useful genes in such areas of stress, since such genes have been responsible for the survival of host crops over the years. Evaluation study was conducted for a range of agronomic characteristics and resistance attributes for 209 local maize collections from Southeastern Nigeria along with three improved check varieties. Field trials were conducted at three locations in a total of four environments in 2001. Highly significant genotypic variances as were noted in all the traits, are indicative of the magnitude of variation that exists among the genotypes, thus providing the opportunity of selection for desirable traits. Furthermore, four traits, namely, leaf feeding, ear damage, stalk lodging and yield were used from across the environments to construct a rank summation index (RSI), which was used to rank the entries for resistance to stem borers. This RSI led to the identification of 11genotypes which represents the best 5% of the 212 genotypes in resistance ability. Genotype AMA TZBR-WC1 (from International Institute of Tropical Agriculture (IITA), Ibadan) had the best overall resistance levels, followed by genotypes SE NG-77 and SE NG-67 (from Umuahia North), SE NG-62 (from Ikwuano), SE NG-148 (from Ukwa West), SE NG-106 (from Bende), SE NG-119 (from Isiala Ngwa), SE NG-33 (from Ikwuano) and SE NG-65 (from Umuahia North)

Host carbon sources modulate cell wall architecture, drug resistance and virulence in a fungal pathogen

The survival of all microbes depends upon their ability to respond to environmental challenges. To establish infection, pathogens such as Candida albicans must mount effective stress responses to counter host defences while adapting to dynamic changes in nutrient status within host niches. Studies of C. albicans stress adaptation have generally been performed on glucose-grown cells, leaving the effects of alternative carbon sources upon stress resistance largely unexplored. We have shown that growth on alternative carbon sources, such as lactate, strongly influence the resistance of C. albicans to antifungal drugs, osmotic and cell wall stresses. Similar trends were observed in clinical isolates and other pathogenic Candida species. The increased stress resistance of C. albicans was not dependent on key stress (Hog1) and cell integrity (Mkc1) signalling pathways. Instead, increased stress resistance was promoted by major changes in the architecture and biophysical properties of the cell wall. Glucose- and lactate-grown cells displayed significant differences in cell wall mass, ultrastructure, elasticity and adhesion. Changes in carbon source also altered the virulence of C. albicans in models of systemic candidiasis and vaginitis, confirming the importance of alternative carbon sources within host niches during C. albicans infection

Effect of some maternal dietary practices on neonatal birth weight in rural and urban areas of Ebonyi State, Nigeria

Background: Maternal dietary practices and the resultant nutritional status is a major determinant of the pace and balance of foetal growth, with effects that have adverse consequence later in infancy and adulthood. Objectives: The study assessed the effect of some maternal dietary practices on neonatal birth weight in Ebonyi State, Nigeria. Material and Methods: The study involved 395 singleton babies delivered in five (5) randomly selected hospitals in the State. Anthropometric measurements of the neonates were taken at birth using standard methods. Data on maternal dietary practices (meal skipping, snacking habit, craving habit and food forbidding habit and other socioeconomic and socio-cultural information were obtained using Focus Group Discussions (FGDs) and validated pretested questionnaire. The data obtained were analysed using appropriate statistics. Result: The prevalence of low birth weight (LBW=<2.5kg) was 4.8%. There was a significant difference (P=0.03) in the prevalence of LBW between urban (8.5%) and rural (3.2%) neonates. There were no significant (P>0.05) difference in the meal skipping habits, snacking pattern and food craving of rural and urban mothers; however, there were significant differences in the reasons for these habits. Significantly (P<0.001) more rural (43.9%) compared to urban mothers (8.5%) forbid some foods. The 24-hour recall of foods consumed showed that 60% had eaten food from the starchy food group, 25% from the meat/legume group, 50% vegetables and 53% fruit group. These practices had no effect on birth weight except for cultural adherence to forbidden foods. More LBW neonates (11%) were found among mothers who forbid some food than those who did not (3.8%), indicating that cultural practices have detrimental effects on birth outcome. Conclusion: This calls for intensive nutrition education by professional Nutritionists/Dietitians

Photometric variability of candidate white dwarf binary systems from Palomar Transient Factory archival data

We present a sample of 59 periodic variables from the Palomar Transient Factory, selected from published catalogues of white dwarf (WD) candidates. The variability can likely be attributed to ellipsoidal variation of the tidally distorted companion induced by the gravity of the primary (WD or hot subdwarf) or to the reflection of hot emission by a cooler companion. We searched 11311 spectroscopically or photometrically selected WD candidates from three hot star/WD catalogues, using the Lomb-Scargle periodogram to single out promising sources. We present period estimates for the candidates, 45 of which were not previously identified as periodic variables, and find that most have a period shorter than a few days. Additionally, we discuss the eclipsing systems in our sample and present spectroscopic data on selected sources