2,585 research outputs found

    Des stratégies d’étude pratiques et personnalisables pour réussir son année d’externat

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    The transition from a pre-clerkship curriculum to the clerkship year presents a need to re-examine and modify study strategies for clinical subject examinations and ultimately the United States Medical License Examination STEP 2 Clinical Knowledge. Efficient and effective learning are keys in balancing the significantly increased responsibility of patient care and decreased time for examination preparation. We describe several customizable study approaches, advice on selecting resources, and methods for applying the educational framework of deliberate practice and corrective feedback to learning during a medical student’s clerkship years. These strategies focus on intentional and outcome-driven self-assessments to identify and patch knowledge gaps tailored to the clerkship year that will empower learners.Le passage du programme de préexternat à l’année d’externat exige que les étudiants revoient leurs stratégies d’étude pour les examens de matières cliniques et, à terme, pour l’examen STEP 2 Clinical Knowledge du United States Medical License Examination. Un apprentissage efficace et efficient est essentiel pour trouver un équilibre entre l’importante augmentation des responsabilités de soins aux patients et la diminution du temps consacré à la préparation des examens. Nous proposons aux étudiants en médecine plusieurs approches d’étude personnalisables, ainsi que des conseils sur la sélection de ressources et méthodes pour appliquer le modèle éducatif de la pratique délibérée et de la rétroaction corrective à leur apprentissage pendant les années d’externat. Ces stratégies, adaptées à l’année d’externat, sont focalisées sur l’autoévaluation intentionnelle et axée sur les résultats pour repérer et combler les lacunes en matière de connaissances. Elles aideront les apprenants à se sentir en confiance de leurs moyens

    Has China caught up to the US in AI research? An exploration of mimetic isomorphism as a model for late industrializers

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    Artificial Intelligence (AI), a cornerstone of 21st-century technology, has seen remarkable growth in China. In this paper, we examine China's AI development process, demonstrating that it is characterized by rapid learning and differentiation, surpassing the export-oriented growth propelled by Foreign Direct Investment seen in earlier Asian industrializers. Our data indicates that China currently leads the USA in the volume of AI-related research papers. However, when we delve into the quality of these papers based on specific metrics, the USA retains a slight edge. Nevertheless, the pace and scale of China's AI development remain noteworthy. We attribute China's accelerated AI progress to several factors, including global trends favoring open access to algorithms and research papers, contributions from China's broad diaspora and returnees, and relatively lax data protection policies. In the vein of our research, we have developed a novel measure for gauging China's imitation of US research. Our analysis shows that by 2018, the time lag between China and the USA in addressing AI research topics had evaporated. This finding suggests that China has effectively bridged a significant knowledge gap and could potentially be setting out on an independent research trajectory. While this study compares China and the USA exclusively, it's important to note that research collaborations between these two nations have resulted in more highly cited work than those produced by either country independently. This underscores the power of international cooperation in driving scientific progress in AI

    Keratinocytes Play a Role in Regulating Distribution Patterns of Recipient Melanosomes In Vitro

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    Melanosomes in keratinocytes of Black skin are larger and distributed individually whereas those within keratinocytes of Caucasian skin are smaller and distributed in clusters. This disparity contributes to differences in skin pigmentation and photoprotection, but the control of these innate distribution patterns is poorly understood. To investigate this process, cocultures were established using melanocytes and keratinocytes derived from different racial backgrounds and were examined by electron microscopy. Melanosomes transferred to keratinocytes were categorized as individual or in various clusters. Melanosome size was also determined for individual and clustered melanosomes. Results indicate that, in our model system, melanosomes in keratinocytes from different racial backgrounds show a combination of clustered and individual melanosomes. When keratinocytes from dark skin were cocultured with melanocytes from (i) dark skin or (ii) light skin, however, recipient melanosomes were individual versus clustered in (i) 77% vs 23% and (ii) 64% vs 36%, respectively. In contrast, when keratinocytes from light skin were cocultured with melanocytes from (iii) dark skin or (iv) light skin, recipient melanosomes were individual versus clustered in (iii) 34% vs 66% and (iv) 39% vs 61%, respectively. These results indicate that recipient melanosomes, regardless of origin, are predominantly distributed individually by keratinocytes from dark skin, and in membrane-bound clusters by those from light skin. There were also differences in melanosome size from dark or light donor melanocytes. Melanosome size was not related to whether the melanosomes were distributed individually or clustered, however, in cocultures. These results suggest that regulatory factor(s) within the keratinocyte determine recipient melanosome distribution patterns

    Heterogeneity in Surface Sensing Suggests a Division of Labor in Pseudomonas aeruginosa Populations

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    The second messenger signaling molecule cyclic diguanylate monophosphate (c-di-GMP) drives the transition between planktonic and biofilm growth in many bacterial species. Pseudomonas aeruginosa has two surface sensing systems that produce c-di-GMP in response to surface adherence. Current thinking in the field is that once cells attach to a surface, they uniformly respond by producing c-di-GMP. Here, we describe how the Wsp system generates heterogeneity in surface sensing, resulting in two physiologically distinct subpopulations of cells. One subpopulation has elevated c-di-GMP and produces biofilm matrix, serving as the founders of initial microcolonies. The other subpopulation has low c-di-GMP and engages in surface motility, allowing for exploration of the surface. We also show that this heterogeneity strongly correlates to surface behavior for descendent cells. Together, our results suggest that after surface attachment, P. aeruginosa engages in a division of labor that persists across generations, accelerating early biofilm formation and surface exploration

    Practical and customizable study strategies for clerkship year success

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    The transition from a pre-clerkship curriculum to the clerkship year presents a need to re-examine and modify study strategies for clinical subject examinations and ultimately the United States Medical License Examination STEP 2 Clinical Knowledge. Efficient and effective learning are keys in balancing the significantly increased responsibility of patient care and decreased time for examination preparation. We describe several customizable study approaches, advice on selecting resources, and methods for applying the educational framework of deliberate practice and corrective feedback to learning during a medical student’s clerkship years. These strategies focus on intentional and outcome-driven self-assessments to identify and patch knowledge gaps tailored to the clerkship year that will empower learners

    Spatial memory for vertical locations

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    Most studies on spatial memory refer to the horizontal plane, leaving an open question as to whether findings generalize to vertical spaces where gravity and the visual upright of our surrounding space are salient orientation cues. In three experiments, we examined which reference frame is used to organize memory for vertical locations: the one based on the body vertical, the visual-room vertical, or the direction of gravity. Participants judged interobject spatial relationships learned from a vertical layout in a virtual room. During learning and testing, we varied the orientation of the participant’s body (upright vs. lying sideways) and the visually presented room relative to gravity (e.g., rotated by 90° along the frontal plane). Across all experiments, participants made quicker or more accurate judgments when the room was oriented in the same way as during learning with respect to their body, irrespective of their orientations relative to gravity. This suggests that participants employed an egocentric body-based reference frame for representing vertical object locations. Our study also revealed an effect of body–gravity alignment during testing. Participants recalled spatial relations more accurately when upright, regardless of the body and visual-room orientation during learning. This finding is consistent with a hypothesis of selection conflict between different reference frames. Overall, our results suggest that a body-based reference frame is preferred over salient allocentric reference frames in memory for vertical locations perceived from a single view. Further, memory of vertical space seems to be tuned to work best in the default upright body orientation

    Smokers' Likelihood to Engage With Information and Misinformation on Twitter About the Relative Harms of e-Cigarette Use:Results From a Randomized Controlled Trial

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    BACKGROUND: Information and misinformation on the internet about e-cigarette harms may increase smokers’ misperceptions of e-cigarettes. There is limited research on smokers’ engagement with information and misinformation about e-cigarettes on social media. OBJECTIVE: This study assessed smokers’ likelihood to engage with—defined as replying, retweeting, liking, and sharing—tweets that contain information and misinformation and uncertainty about the harms of e-cigarettes. METHODS: We conducted a web-based randomized controlled trial among 2400 UK and US adult smokers who did not vape in the past 30 days. Participants were randomly assigned to view four tweets in one of four conditions: (1) e-cigarettes are as harmful or more harmful than smoking, (2) e-cigarettes are completely harmless, (3) uncertainty about e-cigarette harms, or (4) control (physical activity). The outcome measure was participants’ likelihood of engaging with tweets, which comprised the sum of whether they would reply, retweet, like, and share each tweet. We fitted Poisson regression models to predict the likelihood of engagement with tweets among 974 Twitter users and 1287 non-Twitter social media users, adjusting for covariates and stratified by UK and US participants. RESULTS: Among Twitter users, participants were more likely to engage with tweets in condition 1 (e-cigarettes are as harmful or more harmful than smoking) than in condition 2 (e-cigarettes are completely harmless). Among other social media users, participants were more likely to likely to engage with tweets in condition 1 than in conditions 2 and 3 (e-cigarettes are completely harmless and uncertainty about e-cigarette harms). CONCLUSIONS: Tweets stating information and misinformation that e-cigarettes were as harmful or more harmful than smoking regular cigarettes may receive higher engagement than tweets indicating e-cigarettes were completely harmless. TRIAL REGISTRATION: International Standard Randomized Controlled Trial Number (ISRCTN) 16082420; https://doi.org/10.1186/ISRCTN1608242

    A thin layer angiogenesis assay: a modified basement matrix assay for assessment of endothelial cell differentiation

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    BACKGROUND: Basement matrices such as Matrigel™ and Geltrex™ are used in a variety of cell culture assays of anchorage-dependent differentiation including endothelial cell tube formation assays. The volumes of matrix recommended for these assays (approximately 150 μl/cm(2)) are costly, limit working distances for microscopy, and require cell detachment for subsequent molecular analysis. Here we describe the development and validation of a thin-layer angiogenesis (TLA) assay for assessing the angiogenic potential of endothelial cells that overcomes these limitations. RESULTS: Geltrex™ basement matrix at 5 μl/cm(2) in 24-well (10 μl) or 96-well (2 μl) plates supports endothelial cell differentiation into tube-like structures in a comparable manner to the standard larger volumes of matrix. Since working distances are reduced, high-resolution single cell microscopy, including DIC and confocal imaging, can be used readily. Using MitoTracker dye we now demonstrate, for the first time, live mitochondrial dynamics and visualise the 3-dimensional network of mitochondria present in differentiated endothelial cells. Using a standard commercial total RNA extraction kit (Qiagen) we also show direct RNA extraction and RT-qPCR from differentiated endothelial cells without the need to initially detach cells from their supporting matrix. CONCLUSIONS: We present here a new thin-layer assay (TLA) for measuring the anchorage-dependent differentiation of endothelial cells into tube-like structures which retains all the characteristics of the traditional approach but with the added benefit of a greatly lowered cost and better compatibility with other techniques, including RT-qPCR and high-resolution microscopy. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12860-014-0041-5) contains supplementary material, which is available to authorized users

    Standardized immunoprecipitation protocol for efficient isolation of native apolipoprotein E particles utilizing HJ15.4 monoclonal antibody

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    The apolipoprotein E protein (apoE) confers differential risk for Alzheimer\u27s disease depending on which isoforms are expressed. Here, we present a 2-day immunoprecipitation protocol using the HJ15.4 monoclonal apoE antibody for the pull-down of native apoE particles. We describe major steps for apoE production via immortalized astrocyte culture and HJ15.4 antibody bead coupling for apoE particle pull-down, elution, and characterization. This protocol could be used to isolate native apoE particles from multiple model systems or human biospecimens

    Feeling every bit of winter - distributed temperature sensitivity in vernalization

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    Temperature intrinsically influences all aspects of biochemical and biophysical processes. Organisms have therefore evolved strategies to buffer themselves against thermal perturbations. Many organisms also use temperature signals as cues to align behavior and development with certain seasons. These developmentally important thermosensory mechanisms have generally been studied in constant temperature conditions. However, environmental temperature is an inherently noisy signal, and it has been unclear how organisms reliably extract specific temperature cues from fluctuating temperature profiles. In this context, we discuss plant thermosensory responses, focusing on temperature sensing throughout vernalization in Arabidopsis. We highlight many different timescales of sensing, which has led to the proposal of a distributed thermosensing paradigm. Within this paradigm, we suggest a classification system for thermosensors. Finally, we focus on the longest timescale, which is most important for sensing winter, and examine the different mechanisms in which memory of cold exposure can be achieved
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