65 research outputs found

    Wonder Wild: A Philosophical Approach to Understanding Teachers' and Children's Social Representations of Science

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    Currently we know very little about how primary school children and teachers perceive science and its nature. The aim of this study is to gain understanding by conducting a community of inquiry approach through philosophical dialogues in focus groups with children, and interviews and focus groups with teachers. This is to explore the hidden assumptions that children and teachers have about nature of science. The participants were children of year 5 from three Maltese schools and their primary school teachers. Social representations were explored using a central approach to social representations characterised by the main idea being discussed in dialogue and the meanings that children and teachers attach to the idea. This analysis of social representations indicate five social representations from teachers’ dialogue and a total of six social representations from children’s philosophical dialogue. There seems to be common ideas between children’s and teachers’ social representations of nature of science including the view that science is an activity by which scientists study, discover and understand the world in a precise and reliable way. There is agreement amongst children and teachers on some characteristics of science mainly that scientific evidence derives from both observation and experimentation, two scientific methods which took precedence in children’s talk about science. The findings within this research are useful to understand the images that children and teachers have about the nature of science to identify any challenges and concerns which may impede science learning and thus enable teachers and policy makers to meet the needs of the learners

    The prevalence of musculoskeletal injuries in tennis players : a case study

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    Tennis is a popular sport both globally and locally. It is characterised by repeated strokes and explosive movements, which places the athlete at a high – risk of injuries. This study aimed at gathering data on the prevalence of tennis-related musculoskeletal injuries and injury characteristics from a local Maltese tennis club and analyse the impact of using different injury definitions on the number of collected injuries. Through this case study, an adapted version of the OSTRC questionnaire was distributed via email to members of one Maltese amateur tennis club. Using the ‘all physical complaints’ injury definition data on the prevalence and characteristics of musculoskeletal injuries suffered in the previous 6 months was gathered. Results were then analysed via SPSS and Microsoft Office Excel. A total of 61 injuries from 106 participants were recorded, with a point prevalence of 57.5%. 11 out of these 61 injuries were ‘time-loss’ injuries, and 33 were substantial injuries. The most injured locations were the elbow, knee, and ankle. Gradual onset were the most common, with most of them occurring in the elbow (41%). The ankle was mostly impacted by sudden onset injuries (36.3%). Following injury severity calculations, sudden onset injuries to the thigh and gradual onset injuries to the elbow and knee were the most burdensome. Through this study, an overview of injury prevalence and awareness from a small group of tennis players from one club has been obtained, setting recommendations for a local wide scale study to investigate the total population prevalence, information which will provide more insight for physiotherapists to help with injury prevention programmes, especially focusing on the elbow and knee, seeing that both were most frequently recorded and most burdensome.peer-reviewe

    Psychological distress and suicidal ideation in Sicilian Medical Students: The SMS-ME project

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    Background Medical students are at high risk for mental disorders, and the COVID-19 pandemic might have exacerbated psychological distress. However, no data are available for the southern part of Italy. The SMS-ME (Sicilian Medical Students’ MEntal health) project aimed to estimate the prevalence of and predictors of depression, anxiety, stress, and suicidal ideation in a sample of Sicilian medical students. Methods A web-based cross-sectional survey was carried out from September 2022 to December 2022. The study protocol investigated sociodemographic factors and clinical data including Depression, Anxiety, Stress Scale-21 (DASS-21), and a specific question addressing suicidal ideation frequency over the last six months. Multivariate regression models were assessed to examine the association between symptoms and relevant predictors and then regressed their residuals with suicidal thought frequency. Result We collected 1,866 records (age=22.5, SD=3.4; 65.2 % females). One out of four students presented highly severe depression (25 %) and referred to the presence of some suicidal ideation in the six months preceding the interview (26.1 %). DASS-21 scores, especially depression (F(5, 1,828)=58.8, p = 6.59–57), increasingly predicted the frequency of suicidal thoughts when above the sample's mean. Limitations The cross-sectional study design does not allow inferences on temporal relationships and the self-report strategy could be intrinsically biased by the person's feelings at the time of the interview. Conclusions High prevalence of anxiety and depressive symptoms and suicidal thoughts were observed among Sicilian medical students. The DASS-21 was a good predictor for suicidal ideation that Universities could use as a simple tool to assess the need for psychological healthcare in this population

    Transcriptome-Wide Prediction of miRNA Targets in Human and Mouse Using FASTH

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    Transcriptional regulation by microRNAs (miRNAs) involves complementary base-pairing at target sites on mRNAs, yielding complex secondary structures. Here we introduce an efficient computational approach and software (FASTH) for genome-scale prediction of miRNA target sites based on minimizing the free energy of duplex structure. We apply our approach to identify miRNA target sites in the human and mouse transcriptomes. Our results show that short sequence motifs in the 5′ end of miRNAs frequently match mRNAs perfectly, not only at validated target sites but additionally at many other, energetically favourable sites. High-quality matching regions are abundant and occur at similar frequencies in all mRNA regions, not only the 3′UTR. About one-third of potential miRNA target sites are reassigned to different mRNA regions, or gained or lost altogether, among different transcript isoforms from the same gene. Many potential miRNA target sites predicted in human are not found in mouse, and vice-versa, but among those that do occur in orthologous human and mouse mRNAs most are situated in corresponding mRNA regions, i.e. these sites are themselves orthologous. Using a luciferase assay in HEK293 cells, we validate four of six predicted miRNA-mRNA interactions, with the mRNA level reduced by an average of 73%. We demonstrate that a thermodynamically based computational approach to prediction of miRNA binding sites on mRNAs can be scaled to analyse complete mammalian transcriptome datasets. These results confirm and extend the scope of miRNA-mediated species- and transcript-specific regulation in different cell types, tissues and developmental conditions

    Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

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    The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

    Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

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    Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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