Search results

Bystander apathy has been a source of debate for decades. In the past half-century, psychologists developed theoretical frameworks to understand bystander activity, commonly referred to as bystander intervention models (BIMs). More recently, BIMs have been modified to facilitate initiatives to prevent various forms of online victimization. This chapter begins with a review of BIMs and recent applications of bystander intervention research to online environments. We also present several future directions for research along with applications for reducing technology-facilitated violence, including programming recommendations and theoretical development.

This study provides an analysis of professional development school (PDS) dissertation research that focuses on learning in PDSs. These 103 dissertations written between 1990 and 2020 address an aspect of learning in PDS work, including inquiry as a pedagogical learning tool, student learning PK-12, intern/teacher candidate learning, university teacher educator learning, and inservice teacher learning. From the current exploration of PDS dissertations, most especially from the comparison studies, the authors have learned that there is still no clear path to presenting PDS as having a positive impact when compared with non-PDS experiences..

Within each of these categories, the authors examine the dissertations by methodology and explore common themes among dissertation findings. As the PDS movement enters its third decade of inquiry and builds its efficacy on models of learning, the findings provide insight into the degree to which PDS scholars are building on the past to determine future PDS research agendas around learning.

The authors examine the dissertations by methodology and explore common themes among dissertation findings. The themes included: intern learning does happen in PDS sites; PDSs provide structures for intern learning; teacher educators can learn from their PDS work; dissertations in the area of student learning overwhelmingly had inconclusive findings, except for research that focused on targeted interventions, which demonstrated student gains.

With fewer PDS-focused dissertations being written in more recent years, the authors wonder if the complexity of PDS may be a deterrent to the growth and sustainability of this model?

From the current exploration of PDS dissertations, most especially from the comparison studies, the authors have learned that the authors still do not have a clear path to presenting PDS as having a positive impact when compared with non-PDS experiences. However, the authors are beginning to understand the types of studies that are needed to move this agenda forward and hope the work will help inform the PDS community of some.

This is the first known study of PDS dissertations across time.

The purpose of this paper is to investigate the health and medicinal importance of bush tea (Athrixia phylicoides DC) and special tea (Monsonia burkeana Planch. ex Harv), two of Southern African indigenous herbal teas.

The two herbal teas, A. phylicoides and M. burkeana were extracted individually and in combined ratios for analysis. The phenolic content was determined and the different phenolic compounds were identified using thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The anti-diabetic activity of the teas was determined by evaluating the inhibition of both α-amylase and α-glucosidase in vitro. The anti-proliferative activity was measured on human cervical cancer (HeLa) cell line using the MTT (3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium) assay.

Gallic acid, chlorogenic acid and quercetin were identified to be present in significant quantities by TLC. The HPLC quantified the presence of catechin (1.567 mg/g) and chlorogenic acid (1.862 mg/g) in special tea while chlorogenic acid (1.288 mg/g) was present in bush tea. Bush tea and special tea expressed significant levels of phenolic content and high antioxidant activities. Special tea (S100) expressed high inhibition of α-amylase, α-glucosidase and HeLa cell line proliferation when compared to bush tea (B100).

Both bush tea and special tea could provide an alternative for treatment and management of both diabetes and cervical cancer. However, future studies are needed to investigate their synergistic effect with a wide range of other commercial herbal teas.

This paper aims to study the influence of the dimension change of bush-pin on the pressure, oil film thickness, temperature rise and traction coefficient in contact zone by using a thermal elastohydrodynamic lubrication (EHL) model for finite line contact. Concretely, the effects of the equivalent curvature radius of the bush and the pin, and the length of the bush are investigated.

In this paper, the contact between the bush and pin is simplified as finite line contact. The lubrication state is studied by numerical simulation using steady-state line contact thermal EHL. A constitutive equation Ree–Eyring fluid is used in the calculations.

It is found that by selecting an optimal equivalent radius of curvature and prolonging the bush length can improve the lubrication state effectively.

Under specific working conditions, there exists an optimal equivalent radius to maximize the minimum oil film thickness in the contact zone. The increase of generatrix length will weaken the stress concentration effect in the rounded corner area at both ends of the bush, which can improve the wear resistance of chain.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0448.