Yvonne Hodgson

Follitropin (FSH) stimulation of inhibin biological and immunological activities by seminiferous tubules and Sertoli cell cultures from immature rats.

Seminiferous tubules from 20-day-old rats were isolated by mechanical dissection and the conditions to produce optimal inhibin secretion over a 5-day period of culture were established. Inhibin was measured by a specific heterologous radioimmunoassay and by an in vitro bioassay using rat pituitary cells in culture. The tubule production of biologically and immunologically active inhibin was stimulated by ovine follitropin (FSH); however, the ratio of biological to immunological (B:I) activity fell significantly with increasing dose. A similar stimulation of both B and I inhibin activity with a corresponding decrease in B:I ratio with increased FSH dose was also observed using isolated immature Sertoli cells in culture. Fractionation of seminiferous tubule and Sertoli cell culture media by reverse-phase high-performance liquid chromatography (HPLC) revealed the presence of two peaks (I and II) with inhibin biological and immunological activity both of which increased following FSH stimulation. However, while the B:I ratio for peak I remained unchanged following FSH stimulation, the B:I ratio for peak II significantly fell. The molecular weights of peak I and II immunoactivity, determined following fractionation on preparative polyacrylamide gel electrophoresis were 30 kDa and 27 kDa respectively. The 30 kDa peak, based on its inhibin in vitro biological and immunological activity, molecular weight and retention position on HPLC most likely represent 30-32 kDa inhibin. The 27 kDa material remains to be identified.

Perceptions of science graduating students on their learning gains

In this study, the Science Student Skills Inventory was used to gain understanding of student perceptions about their science skills set developed throughout their programme (scientific content knowledge, communication, scientific writing, teamwork, quantitative skills, and ethical thinking). The study involved 400 responses from undergraduate science students about to graduate from two Australian research-intensive institutions. For each skill, students rated on a four-point Likert scale their perception of the importance of developing the skill within the programme, how much they improved it throughout their undergraduate science programme, how much they saw the skill included in the programme, how confident they were about the skill, and how much they will use the skill in the future. Descriptive statistics indicate that overall, student perception of importance of these skills was greater than perceptions of improvement, inclusion in the programme, confidence, and future use. Quantitative skills and ethical thinking were perceived by more students to be less important. t-Test analyses revealed some differences in perception across different demographic groups (gender, age, graduate plans, and research experience). Most notably, gender showed significant differences across most skills. Implications for curriculum development are discussed, and lines for further research are given.

Bronchiolitis obliterans syndrome leads to a functional deterioration of the acinus post lung transplant

ABSTRACT Bronchiolitis obliterans syndrome (BOS) limits long-term survival of lung transplant recipients, and airflow obstruction in these patients likely originates in the small airways. 61 double lung transplant recipients performed multiple breath nitrogen washouts to obtain indices of acinar and conductive ventilation heterogeneity (Sacin, Scond). There was a significant association of BOS status with Sacin (Kruskal–Wallis; p<0.001) but not with Scond (p=0.1). These results demonstrate that it is the structural alteration of the terminal bronchioles, generating ventilation heterogeneity at the level of the diffusion front, and not the bronchioles located more proximally, that is driving the airflow obstruction that determines BOS status.

Factors Influencing Students' Perceptions of Their Quantitative Skills.

There is international agreement that quantitative skills (QS) are an essential graduate competence in science. QS refer to the application of mathematical and statistical thinking and reasoning in science. This study reports on the use of the Science Students Skills Inventory to capture final year science students’ perceptions of their QS across multiple indicators, at two Australian research-intensive universities. Statistical analysis reveals several variables predicting higher levels of self-rated competence in QS: students’ grade point average, students’ perceptions of inclusion of QS in the science degree programme, their confidence in QS, and their belief that QS will be useful in the future. The findings are discussed in terms of implications for designing science curricula more effectively to build students’ QS throughout science degree programmes. Suggestions for further research are offered.

Acute responses of Ley dig cells to hCG: evidence for early hypertrophy of Leydig cells

The cross-sectional area of Leydig cells has been studied in rats following a single injection of 100 IU hCG. Leydig cell size was not changed within 2 h of injection (89.73 +/- 3.02 micron 2) but had increased significantly by 12 h (114.76 +/- 3.57 micron 2). Leydig cell size continued to increase until 24 h when a maximum cross-sectional area of 186.30 +/- 4.72 micron 2 was measured. This area was significantly greater than that recorded after 1 week of daily hCG treatment (143.18 +/- 6.25 micron 2, P less than 0.05). At 48 and 72 h Leydig cell size decreased slightly and was not significantly different from that seen after chronic hCG treatment. A single injection of 100 IU hCG induced a biphasic serum testosterone response with peaks in serum testosterone at 2 h and 72 h, the intervening nadir suggesting a period of in vivo refractoriness. A corresponding period of Leydig cell refractoriness in vitro was also demonstrated 12 h following a single injection of 100 IU hCG and persisted for 48 h. Further injections of hCG on day 2 or 3 did not induce a second biphasic serum testosterone pattern or the accompanying period of refractoriness, indicating that Leydig cell refractoriness is a temporary phenomenon which cannot be maintained during persistent stimulation with hCG. The absence of further refractory periods to hCG during recurrent stimulation may be related to the trophic action of the hormone on Leydig cells.

Engagement of students with lectures in biochemistry and pharmacology

Academic staff at universities have become concerned about the decrease in student attendance at lectures and the implication of this on student achievement and learning. Few studies have measured actual lecture attendance in a coherent or comprehensive way. The aim of this study was to measure actual lecture attendance of students over two year levels enrolled in two separate science disciplines, biochemistry and pharmacology. The study further sought to determine the factors that influence lecture attendance. Attendance at lectures in four units of study was monitored over a 12‐week semester. Attendance at lectures decreased over the semester and was lower at early morning lectures (8 A.M.; 9 A.M.). A questionnaire surveying students about their preparation for lectures, their compensation for missed lectures and the factors influencing their nonattendance was administered at the end of the semester. Students reported that the major factors influencing their attendance at lectures related to timetable issues and the quality of lecturing. If students missed lectures, the majority read the lecture notes and listened to the online recordings. The availability of online recordings of lectures was not a major influence on attendance at lectures. In three of the four units studied there was no correlation between self‐reported lecture attendance and exam performance. The results of the study indicate that universities should dedicate more resources to timetabling and to supporting staff to improve the quality of their lectures.

Assessment and Teaching of Science Skills: Whole of Programme Perceptions of Graduating Students.

This study reports on science student perceptions of their skills (scientific knowledge, oral communication, scientific writing, quantitative skills, teamwork and ethical thinking) as they approach graduation. The focus is on which teaching activities and assessment tasks over the whole programme of study students thought utilised each of the six nominated skills. In this quantitative study involving two Australian research-intensive universities, the teaching activities identified by students as developing the broadest number of skills were laboratory classes and tutorials. Lectures were only effective for developing scientific knowledge and, to a limited extent, ethical thinking. Assessment tasks that students perceived to utilise the broadest range of skills were assignments and oral presentations. The findings of this study document the students’ perspective about their gains in skill sets, and the teaching activities and assessment tasks that require them to use and thus develop these skills. The findings provide an opportunity to evaluate the constructive alignment of skills development, teaching activities and assessment tasks from a student’s perspective. Further research is required to actually measure the skills that students gain over their whole programme of study.

Using action research to improve student engagement in a peer-assisted learning programme

The benefits of students learning together in peer-assisted learning (PAL) programmes have been widely reported. Implementing and evaluating PAL programmes provide specific challenges for academic staff. This paper explains how action research was used to design, trial and refine a same-year PAL programme to enhance student engagement. The PAL programme was successfully integrated into a multidisciplinary radiologic biology unit of study in 2010, following improvement over two trials in 2008 and 2009. The paper demonstrates the value of action research for designing the PAL programme to increase student engagement and for bringing research and practice together by using this experience to contribute to the scholarship of teaching and learning. Key factors influencing the success of the programme were: group size; the provision of structured and unstructured student support; peer assessment; the introduction of case-based learning; and the use of interactive tutorials. Achieving the appropriate balance of these factors increased students’ engagement in their learning.

Continuous and noninvasive recording of cardiovascular parameters with the Finapres finger cuff enhances undergraduate student understanding of physiology

The Finapres finger cuff recording system provides continuous calculations of beat-to-beat variations in cardiac output (CO), total peripheral resistance, heart rate (HR), and blood pressure (BP). This system is unique in that it allows experimental subjects to immediately, continuously, and noninvasively visualize changes in CO at rest and during exercise. This study provides evidence that using the Finapres system improves undergraduate student engagement, understanding, and learning of how the cardiovascular system responds to exercise. Second-year science students undertaking a physiology practical class in 2009 (n = 243) and 2010 (n = 263) used the Finapres system to record CO, BP, and HR during graded exercise on a cycle ergometer. Student experiences with the Finapres was evaluated with a survey (a 5-point scale from strongly disagree to strongly agree). This indicated that students appreciated the immediacy of the recordings (88% of students agreed or strongly agreed, average for 2009 and 2010), gained an understanding of how to record physiological data (84%), enjoyed the practical (81%), and would recommend the Finapres to other students (81%). To determine if the practical enhanced student learning of cardiovascular physiology, identical tests were given to the students at the beginning (pretest) and end (posttest) of the class. There was a significant improvement from the pretest to the posttest (4% in 2009 and 20% in 2010). In summary, the ability of the Finapres to continuously display CO, BP, and HR during experimental protocols provides students with immediate feedback and improves their understanding of cardiovascular physiology.

Student conceptions of peer-assisted learning

This article reports on a programme in which peer-assisted learning (PAL) was combined with case-based learning (CBL) in a second-year radiologic biology unit of study. Our aim is to explore evidence of whether PAL supported the development of qualitative conceptions of learning. The programme involved students in small PAL groups preparing and offering a tutorial based on a case study for the class (large PAL group). The small PAL group assessed the learning of the large PAL group, while the large group gave feedback to the small group. Small groups attended a debriefing session following the tutorial. A six-category framework related to conceptions of learning was developed to guide qualitative analysis of data derived from a student questionnaire, the debriefing sessions and a final focus group. Data analysis indicated some evidence of quantitative conceptions of learning (particularly early in the programme), and showed that PAL played a role in developing students’ qualitative conceptions of learning, particularly through the social and affective processes involved and opportunities for developing metacognitive knowledge. The programme contributed to ‘deep’ processing as students learnt from and with each other. Concurrently, students’ feelings of responsibility to their peers increased their responsibility for their own learning. The PAL approach that was used provides a basis for further exploration of the role of peers in developing students’ conceptions of learning.