Curcumin ameliorates memory deficits via neuronal nitric oxide synthase in aged mice

A number of neuroprotective effects of curcumin have been demonstrated in recent years. However, whether curcumin exerts any beneficial effects on age-related impaired cognition and memory has not been well characterized; nor was there any detailed data on the molecular pathways activated by curcumin. The present study attempts to investigate the effects of curcumin on memory decline of aged mice with a focus upon the possible contribution of the neuronal nitric oxide synthase (nNOS)/nitric oxide (NO) pathway in the memory amelioration effect of curcumin. The results showed that chronic administration of curcumin (50mg/kg, i.p., 21 days) significantly ameliorated the memory acquisition ability of aged male mice in the novel object recognition and passive avoidance tasks. Immunoblotting revealed that chronic treatment of curcumin increased nNOS expression in the prefrontal cortex, amygdala and hippocampus, as well as the enhancement of nNOS activity and NO concentration. This enhancement was suppressed by pre-treatment with 7-nitroindazole (7-NI), a specific inhibitor of neuronal nitric oxide synthase (nNOS). Furthermore, inhibition of nNOS synthase by 7-NI also prevented the memory improvement effects of curcumin in aged mice. Taken together, the results of the present study suggest that the amelioration of memory deficits by curcumin in aged mice was mediated, at least in part, by activating the nNOS activity in specific brain regions. These findings reveal the therapeutic potential of curcumin as a preventive agent upon the deterioration of cognitive faculties.

The efficacy of self-directed learning versus problem-based learning for teaching and learning ophthalmology: a comparative study

INTRODUCTION

Self-directed learning (SDL) and problem-based learning (PBL) are fundamental tools to achieve lifelong learning in an integrated medical curriculum. However, the efficacy of SDL in some clinical courses is debated.

AIM

The aim of the study was to measure the effectiveness of SDL for an ophthalmology course in comparison with PBL.

METHODS

A cross-sectional study was conducted with fifth-year medical students enrolled in an ophthalmology course. SDL comprised four case-based scenarios guided by several questions. PBL comprised three sessions. An ear, nose, and throat (ENT) course was selected for comparison as a control. At the end of the course, 30 multiple-choice questions (MCQs) for both SDL and PBL were assessed and analyzed against their counterparts in the ENT course by an independent t-test.

RESULTS

For the SDL component of the ophthalmology course, the number and percentages of students attaining high (n = 6/60, 10%) and moderate (n = 15/60, 28.3%) scores on an MCQs written exam were evaluated. For the PBL component, high scores were seen for 23.3% (n = 14/60), and moderate scores for 33.3% (n = 20/60) of the participants. For the SDL component of the ENT course, the number and percentages of students attaining high (n = 14/60, 23.3%) and moderate (n = 17/60, 28.3%) scores were recorded. For the PBL component, high (16/60, 26.6%) and moderate (17/60, 28%) scores were recorded. Significant p-values were obtained between the results for SDL and PBL in the ophthalmology course (p = 0.009), as well as between SDL results for both courses (p = 0.0308). Moreover, differences between the SDL results of ophthalmology and the PBL results of ENT (p = 0.0372) were significant.

CONCLUSION

SDL appears to be less valuable for promotion of self-readiness. Periodic discussions in small groups or by panel discussion are strongly recommended for students to enhance readiness with SDL.

Influence of epistatic segregation distortion loci on genetic marker linkages in Japanese flounder

For genetic linkage analysis of Japanese flounder, 160 doubled haploids (DH) were artificially produced using mitotic gynogenesis and were genotyped for 458 simple sequence repeat (SSR) markers, 101 of which show distortional segregation. The genetic linkage map was constructed by modifying recombination fractions between the distorted markers. Between the corrected and uncorrected genetic maps, there were considerable differences in genetic distance, but not in relative locations among markers. Using a liability model, a segregation distortion locus (SDL), with an additive genetic effect of 1.772, was mapped between markers BDHYP387 and Poli56TUF of chromosome 24 in the corrected genetic map. Additionally, six pairs of epistatic SDLs were identified on chromosomes 1, 5, 8, 9, 23, and 24. Changes in genetic distances between markers did not occur on chromosome regions with main effect SDLs. However, most chromosome regions where genetic distances changed covered the detected epistatic SDLs. This study concluded that epistatic SDLs decrease linkages between markers and lengthen genetic distances in Japanese flounder. This finding has been partially validated in other DH populations derived from three female Japanese flounders.

Effect of microwave hydrolysis on transformation of steroidal hormones during anaerobic digestion of municipal sludge cake

Fate and removal of 16 steroidal (estrogenic, androgenic and progestogenic) hormones were studied during advanced anaerobic digestion of sludge cake using microwave (MW) pretreatment. Effect of pretreatment temperature (80, 120, 160 °C), operating temperature (mesophilic at 35 ± 2 °C, thermophilic at 55 ± 2 °C) and sludge retention time (SRT: 20, 10, 5 days) were studied employing eight lab-scale semi-continuously fed digesters. To determine the potential effect of MW hydrolysis, hormones were quantified in total (sorbed + soluble) and supernatant (soluble) phases of the digester influent and effluent streams. Seven of 16 hormones were above the method reporting limit (RL) in one or more of the samples. Hormone concentrations in total phase of un-pretreated (control) and pretreated digester feeds ranged in <157-2491 ng/L and <157-749 ng/L, respectively. The three studied factors were found to be statistically significant (95% confidence level) in removal of one or more hormones from soluble and/or total phase. MW hydrolysis of the influent resulted in both release (from sludge matrix) and attenuation of hormones in the soluble phase. Accumulation of estrone (E1) as well as progesterone (Pr) and androstenedione (Ad) in most of the digesters indicated possible microbial transformations among the hormones. Compared to controls, all pretreated digesters had lower total hormone concentrations in their influent streams. At 20 days SRT, highest total removal (E1+E2+Ad +Pr) was observed for the thermophilic control digester (56%), followed by pretreated mesophilic digesters at 120 °C and 160 °C with around 48% efficiency. In terms of conventional performance parameters, relative (to control) improvements of MW pretreated digesters at a 5-d SRT ranged in 98-163% and 57-121%, for volatile solids removal and methane production, respectively.

Self-directed learning and practice of Italian osteopathic students during summer break: a cross-sectional survey

Background

Self-directed learning is a student-centered approach based on the students’ evaluation about their own learning needs. Self-directed practice is a component of the self-directed learning which focus on achieving manual and practical skills. Given the abundance of manual skills that students need to develop in the osteopathic curriculum, self-directed practice has become an attractive methodology. Most of the Italian osteopathic educational institutions recognize two types of educational curriculum: T1, for students without a healthcare background; and T2 for students who are already healthcare professionals. The aim of the present study is to investigate the attitudes of Italian osteopathic students toward self-directed practice during the summer break highlighting the possible differences between T1 and T2 students.

Methods

A web-based closed-ended survey was administered to the students attending one of the Italian osteopathic educational institutions which accepted to participate in the research.

Results

Two hundred sixty-eight students on 2549 participated to the survey. 64.92% of the students reported to have performed self-directed practice during the summer break. The main difficulty encountered by students in approaching self-directed practice was ‘lack of people to exercise with’. Most of the students performed self-directed practice between 1 to 5 h per week. The most common clinical condition encountered was Low Back Pain. The anatomical area most approached was lumbar spine. The most commonly simulated tests were the articular mobility tests. The techniques in which students trained the most were muscle energy techniques. Significant difference was found in self-engagement to the self-directed practice between T1 and T2 students (p = 0.026), and in the reasons to perform self-directed practice (p = 0.027).

Conclusions

The results of this study could be useful to reveal some aspects of students’ academic education and future clinical practice. Therefore this paper can be a useful tool for the institutions to develop strategies to overcome the reported problems students have towards self-directed practice. For example it should be discussed the possibility for the students to observe some senior osteopaths during their practice or to plan to maintain an open tutored didactic environment during the summer break as an extracurricular activity.

A conceptual framework of supply chain resilience towards sustainability through a service-dominant logic perspective

The supply chain of every company is essential to its overall operation. Global disruption has an unanticipated and immediate impact on supply chains across all industrial sectors. The supply chain must, therefore, demonstrate resilience in order to resist such upheaval because it is dynamic and extremely vulnerable to global uncertainties. Moreover, it must not only return to its initial form but also prove able to achieve steady, sustainable performance. To do so, supply chain activities necessitate value co-creation between stakeholders. One means of achieving this objective is through the application of service-dominant logic (SDL) whose eleven core premises define the behaviour, governance, and consequences of service-based exchange. The novelty of the research reported here lies in the mapping and review frameworks of current supply chain resilience towards sustainability (SCRTS) from an SDL perspective. This study represents the first to combine an SDL perspective and SCRTS since no formula has yet been devised to address this combination of factors. This study proposes the application of a conceptual framework of SCRTS from an SDL perspective by involving selected premises, resource integration, institutional structures, and collaboration.

Type of Paper

Conceptual Framework.

Self-Directed-Team Learning (SDTL) in Medical Education

To prepare for the complex and evolving world of clinical practice, medical students must acquire a large body of knowledge, become proficient pursuing self-directed learning (SDL), and learn to collaborate effectively in teams. We propose an innovative educational approach that fosters these competencies and was inspired by both SDL and team-based learning (TBL), called self-directed-team learning (SDTL).

Exploring influencing factors and facilitating strategies for self-directed learning from the perspective of medical trainees: a multicentre qualitative study in China

OBJECTIVES

Exploration of influencing factors and promotion strategies for self-directed learning (SDL) is a current research hotspot. However, there is a dearth of relevant research among medical trainees. The objective of the present study was to explore the perceptions of SDL among medical trainees, while also identifying the multidimensional factors associated with SDL and potential facilitating strategies from the perspective of medical trainees.

DESIGN

This multicentre qualitative study used focus group discussions to gather insights into SDL, analysed through thematic analysis. NVivo V.12 was used for efficient data management and processing.

SETTING

Four focus group discussions were held at three large tertiary hospitals in mainland China from December 2022 to July 2023.

PARTICIPANTS

This study used purposive sampling to recruit eligible participants from the selected hospitals, primarily through instructor recommendations. Recruitment was further supported by snowball sampling, where trainees who completed the interviews referred additional participants. Medical trainees from three major tertiary hospitals in mainland China were ultimately invited to participate in the study.

RESULTS

A total of four focus group discussions were conducted involving 17 medical trainees. Thirteen themes were summarised and assigned into three categories: (1) perceptions of SDL among medical trainees, (2) multidimensional factors affecting SDL among medical trainees and (3) potential improvement strategies.

CONCLUSION

This qualitative study investigated the perspectives of medical trainees regarding SDL across various grades and hospitals in mainland China. The participants universally acknowledged the significance of SDL and expressed a strong aspiration to enhance their competence in this area. The study identified that the factors influencing SDL abilities are multifaceted, highlighting the need for tailored intervention strategies to address these challenges effectively.

Five years of lesson modification to implement non-traditional learning sessions in a traditional-delivery curriculum: A retrospective assessment using applied implementation variables

Non-traditional learning (NTL), including aspects of self-directed learning (SDL), may address self-awareness development needs. Many factors can impact successful implementation of NTL.

OBJECTIVES

To share our multi-year experience with modifications that aim to improve NTL sessions in a traditional curriculum. To improve understanding of applied implementation variables (some of which were based on successful SDL implementation components) that impact NTL.

METHODS

We delivered a single lesson in a traditional-delivery curriculum once annually for five years, varying delivery annually in response to student learning and reaction-to-learning results. At year 5, we compared student learning and reaction-to-learning to applied implementation factors using logistic regression.

RESULTS

Higher instructor involvement and overall NTL levels predicted correct exam responses (p=0.0007 and p<0.0001, respectively). Exam responses were statistically equivalent between the most traditional and highest overall NTL deliveries. Students rated instructor presentation skills and teaching methods higher when greater instructor involvement (p<0.0001, both) and lower overall NTL levels (P<0.0001, both) were used. Students perceived that teaching methods were most effective when lower student involvement and higher technology levels (p<0.0001, both) were used.

CONCLUSION

When implementing NTL sessions as a single lesson in a traditional-delivery curriculum, instructor involvement appears essential, while the impact of student involvement and educational technology levels varies.

Understanding the mechanisms of household and stakeholder engagement in a recycling ecosystem: The SDL perspective

For a recycling system to work, both stakeholders and households need to feel engaged in the process. When studying engagement in the context of recycling, it is clear that a broader view is necessary to understand the opportunities and limitations that exist among stakeholders and users. Service dominant logic is undertaken to shed new light on how stakeholders, with the household as a focal point, engage with each other in the service ecosystem. Thematic network analysis was employed using interviews with households, stakeholders, as well as workshops in a project about recycling. The analysis reveals four mechanisms (channeling information, managing different resources, understanding impact, and dynamic and time-related engagement). There are several goals and values present when stakeholders and households engage with each other. When values of different actors align, it provides a solid basis for collaboration. Engagement was also found to be time-related and linked to calculated or perceived future effects, but also required to be maintained with the integration of different resources (e.g. money, space, time, cognitive, emotional, bodily energy). In the short-term perspective, utilitarian (functional) values such as the function of the recycling house emerged essential, while the long-term perspectives included feelings about the environment or one's own contribution. Implications for waste management include the importance of recognizing the relation between, and the involvement of stakeholders and households, as well as understanding how these interact to optimize recycling systems.

Listening to student voice-understanding student and faculty experience at two UK graduate entry programmes

CONTEXT

Shortage of physicians in the UK has been a long-standing issue. Graduate entry medicine (GEM) may offer a second point of entry for potential doctors. However, the challenges of developing and implementing these programmes are still unrecognised. This small-scale study aimed to briefly explore the opportunities and challenges facing students at two UK GEM programmes.

METHODS

Two case studies were conducted at Imperial College and Scotland's GEM (ScotGEM) and used a triangulated qualitative approach via semi-structured and elite interviews. Data analysis, informed by grounded theory, applied thematic and force-field analysis in an empirical approach to generate evidence and instrumental interpretations for Higher Education Institutions.

RESULTS

Although GEM forms an opportunity for graduates to enter medicine, the different drivers of each programme were key in determining entry requirements and challenges experienced by postgraduates. Three key dilemmas seem to influence the experiences of learners in GEM programmes: (a) postgraduate identity and the everchanging sense-of-self; (b)self-directed and self-regulated learning skills, and (c) servicescape, management and marketing concepts.

CONCLUSIONS

Graduate entry programmes may support policy makers and faculty to fill the workforce gap of healthcare professionals. However, their successful implementation requires careful considerations to the needs of graduates to harness their creativity, resilience and professional development as future healthcare workers.

Structural insights into the molecular recognition of integrin αVβ3 by RGD-containing ligands: The role of the specificity-determining loop (SDL)

Integrin αVβ3 is a prominent member of the "RGD-recognizing" integrin family of cell surface receptors. αVβ3 binds to various extracellular matrix (ECM) proteins and oxysterols such as 25-hydroxycholesterol, is implicated in several diseases, including cancer metastasis, lung fibrosis, inflammation, and autoimmune diseases, and is pursued as a valuable therapeutic target. Despite enormous efforts to seek a pure antagonist, to date, no single drug candidate has successfully reached clinics due to associated partial agonism and toxicity issues. Developing effective and safe inhibitors require a thorough understanding of the molecular interactions and structural changes related to the receptor's activation and inhibition mechanisms. This study offers a comprehensive residue-residue contact and network analyses of the ligand-binding β-propeller βI domains (headpiece) based on all available experimental structures of integrin αVβ3 in unliganded, agonist-, antagonist-, and antibody-bound states. The analyses reveal many critical interactions that were not reported before and show that specific orientation and interactions of residues from the specificity-determining loop (SDL) are critical in molecular recognition and regulation. Also, the network analysis reveals that residues from the nearby allosteric site (site II) connect to the primary RGD-binding site via SDL, which likely acts as an interface between the two sites. Our results provide valuable insights into molecular interactions, structural changes, distinct features of the active and inactive headpiece conformations, the role of SDL in ligand recognition, and SDL-mediated allostery. Thus, the insights from this study may facilitate the designing of pure antagonists or site II-mediated allosteric modulators to integrin αVβ3 to treat various diseases.