Teachers' peer support: difference between perception and practice

This paper is aimed at exploring teachers’ perceptions and practices of peer support in Bangladeshi primary schools. It also looks into the contrast between the perceptions and practices, and the underlying reasons behind such deviations. The study collects data from teachers who are undergoing a large-scale teacher development project called English in Action. The project provides face-to-face and distance learning support to the teachers, as well as promotes the idea of context-based learning through peer support in both primary and secondary schools in Bangladesh. This study adopted a mixed method approach. The quantitative part looks into teachers’ perceptions and practices in regards to peer support. A close-ended questionnaire was used to understand the extent teachers feel peer support is important and their actual engagement with colleagues for the support activities. Qualitative methods including observations, focus group discussions, and interviews are used to identify the activities that teachers do together with their colleagues in a school and the barriers to such activities. The results show that, teachers define peer support in a specific way and consider it as very important for their professional development. However, their engagement in such activities is restricted by several factors.     

A Novel Approach to Investigate the Impact of Mindset and Physiology on the Choice to Invest Effort During an Arithmetic Task

Growth mindset, the belief that personal attributes such as intelligence are malleable, has previously been related to more effort investment. Here, we investigated how undergraduates' mindset (N = 114) relates to the choice to invest effort during an arithmetic task, indexed by whether they make low vs. high effort-related choices. Social cognitive theory suggests that past performance experiences (mastery vs. failure) and physiological state are important sources for competence self-evaluations. Therefore, in addition to mindset, we also investigated how effort-related choices are influenced more dynamically, by failures and physiological responses during the task. Growth mindset and physiological effort mobilization did not predict effort-related choices but making mistakes did predict lower effort choices in the subsequent round. This study further supports the importance of mastery experiences for effort investment and provides a novel approach for integrating different levels of influence on effort-related choices during an educationally-relevant task.     

Influence of surface treatments on fatigue life of a two-stroke free piston linear engine component using random loading

INTRODUCTION Fatigue durability has long been important issues in the design of a two-stroke free piston linear engine structure (Torres and Voorwald, 2002; Rahman et al., 2005a; 2005b). Durability assessment is traditionally done in the later part of the product development stage when prototypes are available, and heavily re- lied on in confirming ground durability tests. This process is very time consuming and often results in over-design with weight penalties, which is the major obsta…     

An extension of the general Struble's method for solving an nth order nonlinear differential equation when the corresponding unperturbed equation has some repeated eigenvalues

This paper attempts to show the more suitability of the extended general Struble's technique than the unified Krylov-Bogoliubov-Mitropolskii (KBM) method in solving the problems that occur during the critical conditions. Recently a critically damped condition of an nth, n=2,3, … order weakly nonlinear autonomous ordinary differential equation has been investigated by the unified KBM method, in which the corresponding unperturbed equation has some real (negative) repeated eigenvalues. But there are more important critical conditions, which are still untouched. One of them occurs when a pair of complex eigenvalues is equal to another. It is complicated to formulate as well as to utilize the KBM method to investigate this condition. However, the extended general Struble's technique is applicable to both autonomous and non-autonomous systems. Solutions obtained for different critical conditions as well as for different initial conditions show a good agreement with the numerical solutions. The method is illustrated by an example of a fourth-order nonlinear differential equation whose unperturbed equation has repeated complex eigenvalues. A steady-state solution is determined for the non-autonomous equation. Moreover, a critical condition of a fourth-order nonlinear equation is investigated when two real eigenvalues of the unperturbed equation are non-positive and equal.     

Detection of human papillomavirus in oropharyngeal squamous cell carcinoma

Worldwide there has been a significant increase in the incidence of oropharyngeal squamous cell carcinoma (OPSCC) etiologically attributed to oncogenic human papillomavirus (HPV). Reliable and accurate identification and detection tools are important as the incidence of HPV-related cancer is on the rise. Several HPV detection methods for OPSCC have been developed and each has its own advantages and disadvantages in regard to sensitivity, specificity, and technical difficulty. This review summarizes our current knowledge of molecular methods for detecting HPV in OPSCC, including HPV DNA/RNA polymerase chain reaction (PCR), loop-mediated isothermal amplification (LAMP), p16 immunohistochemistry (IHC), and DNA/RNA in situ hybridization (ISH) assays. This summary may facilitate the selection of a suitable method for detecting HPV infection, and therefore may help in the early diagnosis of HPV-related carcinoma to reduce its mortality, incidence, and morbidity.     

Assessment of the phase synchronization effect in modal testing during operation

The impact-synchronous modal analysis (ISMA), which uses impact-synchronous time averaging (ISTA), allows modal testing to be performed during operation. ISTA is effective in filtering out the non-synchronous cyclic load component, its harmonics, and noises. However, it was found that at operating speeds that coincide with the natural modes, ISMA would require a high number of impacts to determine the dynamic characteristics of the system. This finding has subsequently reduced the effectiveness and practicality of ISMA. Preservation of signatures during ISTA depends on the consistency of their phase angles on every time block but not necessarily on their frequencies. Thus, the effect of phase angles with respect to impact is seen to be a very important parameter when performing ISMA on structures with dominant periodic responses due to cyclic load and ambient excitation. The responses from unaccounted forces that contain even the same frequency as that contained in the response due to impact are diminished with the least number of impacts when the phase of the periodic responses is not consistent with the impact signature for every impact applied. The assessment showed that a small number of averages are sufficient to eliminate the non-synchronous components with 98.48% improvement on simulation and 95.22% improvement on experimental modal testing when the phase angles with respect to impact are not consistent for every impact applied.     

Absence of postzygotic isolating mechanisms: evidence from experimental hybridization between two species of tropical sea urchins

Two reef margin species of tropical sea urchins, Echinometra sp. C (Ec) and Echinometra oblonga (Eo), occur sympatrically on Okinawa intertidal reefs in southern Japan. Hybridization between these species was examined through a series of cross-fertilization experiments. At limited sperm concentrations, where conspecific crosses reached near 100% fertilization, both heterospecific crosses showed high fertilization rates (81%–85%). The compatibility of the gametes demonstrated that if gamete recognition molecules are involved in fertilization of these species, they are not strongly species-specific. We found that conspecific crosses reached peak fertilization levels much faster than did heterospecific crosses, indicating the presence of a prezygotic barrier to hybridization in the gametes. Larval survival, metamorphosis, and juvenile and adult survival of hybrid groups were nearly identical to those of their parent species. Hybrids from crosses in both directions developed normally through larval stages to sexually mature adults, indicating that neither gametic incompatibility nor hybrid inviability appeared to maintain reproductive isolation between these species. In adults, Ec×Ec crosses gave the highest live weight, followed by Eo (ova)×Ec (sperm), Ec (ova)×Eo (sperm), and Eo×Eo. Other growth performance measures (viz., test size, Aristotle’s lantern length, and gonad index) of hybrid groups and their parental siblings showed the same trends. The phenotypic color patterns of the hybrids were closer to the maternal coloration, whereas spine length, tube-foot and gonad spicule characteristics, pedicellaria valve length, and gamete sizes showed intermediate features. Adult F₁ hybrids were completely fertile and displayed high fertilization success in F₁ backcrosses, eliminating the likelihood that hybrid sterility is a postzygotic mechanism of reproductive isolation. Conversely, intensive surveys failed to find hybrid individuals in the field, suggesting the lack or rarity of natural hybridization. This strongly suggests that reproductive isolation is achieved by prezygotic isolating mechanism(s). Of these mechanisms, habitat segregation, gamete competition, differences in spawning times, gametic incompatibility or other genetic and non-genetic factors appear to be important in maintaining the integrity of these species.     

Non-occupational lead exposure and hypertension in Pakistani adults

INTRODUCTION Blood-Pb levels are taken as representative of dose/exposure, as all clinical symptoms resulting from the toxic effects of Pb are manifested mainly in blood. Lead exposure of children correlates with de- creased IQ, symptoms of hyper kinesis or minima brain dysfunction, poor learning, or defects in specific neuromotor tasks (Landgrin et al., 1980). Large number of observations over the years has associated lead exposure with human diseases (McMichael and Johnson, 1982). Ca…     

Enantioselective assembly of multi-layer 3D chirality

The first enantioselective assembly of sandwich-shaped organo molecules has been achieved by conducting dual asymmetric Suzuki-Miyaura couplings and nine other reactions. This work also presents the first fully C-C anchored multi-layer 3D chirality with optically pure enantiomers. As confirmed by X-ray diffraction analysis that this chiral framework is featured by a unique C₂-symmetry in which a nearly parallel fashion consisting of three layers: top, middle and bottom aromatic rings. Unlike the documented planar or axial chirality, the present chirality shows its top and bottom layers restrict each other from free rotation, i.e., this multi-layer 3D chirality would not exist if either top or bottom layer is removed. Nearly all multi-layered compounds showed strong luminescence of different colors under UV irradiation, and several randomly selected samples displayed aggregation-induced emission (AIE) properties. This work is believed to have broad impacts on chemical, medicinal and material sciences including optoelectronic materials in future.