41 research outputs found

    “The First Day He Kicked Shoes at Me, the Last Day He Brought Me a Picture of Himself”: Investigating the Practicum Experiences of Pre-service Teachers

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    The purpose of this study was to describe the ways in which the experiences gained during practica influence the developing self-efficacy of Canadian pre-service teachers for teaching in inclusive classrooms. Questionnaires were issued to participants in teacher education programs at 11 universities across Canada, and the data were subjected to content analysis. Several themes that emerged from the participant responses were found to be influential in pre-service teachers’ feelings of efficacy, with behaviour management having the greatest influence, regardless of whether participants felt successful or challenged. Academic outcomes, relationships with students, and other school adults as resources were also identified as themes influencing pre-service teachers’ feelings of success and challenge in practica. The data revealed attitudes and beliefs about inclusion and the impact these may have on teacher efficacy. Several elements can positively influence teacher efficacy including the ability to identify and utilize instructional and personnel resources, the ability to form supportive professional relationships with other school adults, and the ability to recognize achievement as it pertains to the individual rather than prescribed norms. As beliefs about self-efficacy are informed by enactive mastery experiences, vicarious experiences, physiological factors, and verbal persuasion, teacher preparation programs can foster teacher efficacy by encouraging the development of positive attitudes and equipping teachers with the skills they need

    Photosynthetic production of enantioselective biocatalysts

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    Background:\bf Background: Global resource depletion poses a dramatic threat to our society and creates a strong demand for alternative resources that do not compete with the production of food. Meeting this challenge requires a thorough rethinking of all steps of the value chain regarding their sustainability resource demand and the possibility to substitute current, petrol-based supply-chains with renewable resources. This regards also the production of catalysts for chemical synthesis. Phototrophic microorganisms have attracted considerable attention as a biomanufacturing platform for the sustainable production of chemicals and biofuels. They allow the direct utilization of carbon dioxide and do not compete with food production. Photosynthetic enzyme production of catalysts would be a sustainable supply of these important components of the biotechnological and chemical industries. This paper focuses on the usefulness of recombinant cyanobacteria for the photosynthetic expression of enantioselective catalysts. As a proof of concept, we used the cyanobacterium Synechocystis\it Synechocystis sp. PCC 6803 for the heterologous expression of two highly enantioselective enzymes. Results:\bf Results: We investigated the expression yield and the usefulness of cyanobacterial cell extracts for conducting stereoselective reactions. The cyanobacterial enzyme expression achieved protein yields of 3% of total soluble protein (%TSP) while the expression in E. coli\textit {E. coli} yielded 6-8% TSP. Cell-free extracts from a recombinant strain expressing the recombinant esterase ST0071 from the thermophilic organism Sulfolobus tokodai\textit {Sulfolobus tokodai} ST0071 and arylmalonate decarboxylase from Bordetella bronchiseptica\textit {Bordetella bronchiseptica} showed excellent enantioselectivity (>99% ee) and yield (>91%) in the desymmetrisation of prochiral malonates. Conclusions:\bf Conclusions: We were able to present the proof-of-concept of photoautotrophic enzyme expression as a viable alternative to heterotrophic expression hosts. Our results show that the introduction of foreign genes is straightforward. Cell components from Synechocystis\it Synechocystis did not interfere with the stereoselective transformations, underlining the usability of photoautotrophic organisms for the production of enzymes. Given the considerable commercial value of recombinant biocatalysts, cyanobacterial enzyme expression has thus the potential to complement existing approaches to use phototrophic organisms for the production of chemicals and biofuels

    Pitfalls in machine learning‐based assessment of tumor‐infiltrating lymphocytes in breast cancer: a report of the international immuno‐oncology biomarker working group

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    The clinical significance of the tumor-immune interaction in breast cancer (BC) has been well established, and tumor-infiltrating lymphocytes (TILs) have emerged as a predictive and prognostic biomarker for patients with triple-negative (estrogen receptor, progesterone receptor, and HER2 negative) breast cancer (TNBC) and HER2-positive breast cancer. How computational assessment of TILs can complement manual TIL-assessment in trial- and daily practices is currently debated and still unclear. Recent efforts to use machine learning (ML) for the automated evaluation of TILs show promising results. We review state-of-the-art approaches and identify pitfalls and challenges by studying the root cause of ML discordances in comparison to manual TILs quantification. We categorize our findings into four main topics; (i) technical slide issues, (ii) ML and image analysis aspects, (iii) data challenges, and (iv) validation issues. The main reason for discordant assessments is the inclusion of false-positive areas or cells identified by performance on certain tissue patterns, or design choices in the computational implementation. To aid the adoption of ML in TILs assessment, we provide an in-depth discussion of ML and image analysis including validation issues that need to be considered before reliable computational reporting of TILs can be incorporated into the trial- and routine clinical management of patients with TNBC

    Canonical BMP–Smad Signalling Promotes Neurite Growth in Rat Midbrain Dopaminergic Neurons

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    Ventral midbrain (VM) dopaminergic (DA) neurons project to the dorsal striatum via the nigrostriatal pathway to regulate voluntary movements, and their loss leads to the motor dysfunction seen in Parkinson’s disease (PD). Despite recent progress in the understanding of VM DA neurogenesis, the factors regulating nigrostriatal pathway development remain largely unknown. The bone morphogenetic protein (BMP) family regulates neurite growth in the developing nervous system and may contribute to nigrostriatal pathway development. Two related members of this family, BMP2 and growth differentiation factor (GDF)5, have neurotrophic effects, including promotion of neurite growth, on cultured VM DA neurons. However, the molecular mechanisms regulating their effects on DA neurons are unknown. By characterising the temporal expression profiles of endogenous BMP receptors (BMPRs) in the developing and adult rat VM and striatum, this study identified BMP2 and GDF5 as potential regulators of nigrostriatal pathway development. Furthermore, through the use of noggin, dorsomorphin and BMPR/Smad plasmids, this study demonstrated that GDF5- and BMP2-induced neurite outgrowth from cultured VM DA neurons is dependent on BMP type I receptor activation of the Smad 1/5/8 signalling pathway

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

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    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Why is Asp-286 conserved in the V-ATPase? : an honors thesis (HONRS 499)

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    V-ATPases are multi-subunit proton pumps found on the cellular membranes of most organisms from yeast (Saccharomyces cerviseae) to humans. They are composed of two main components capable of reversible disassembly: V1 and V0. VI is composed of eight different subunits and is the peripheral domain, whereas Vo is composed of five different subunits and is the integral domain. The long-term objective of this research is to determine the function of one of these subunits on the V. complex: subunit d, encoded by the VMA6 gene. Subunit d is of interest because it serves as the bridge between V I and Vo.Asp-286 of subunit d is highly conserved in mammals, insects and fungi, suggesting that it may be important for V-ATPase function. Using QuikChange site-directed mutagenesis by PCR, a mutation was introduced in subunit d. The mutation substituted aspartic acid on position 286 with alanine. We hypothesized that if Asp-286 has a structural role in subunit d, this change would modify the tertiary structure of subunit d and possibly alter the activity and assembly of the V-ATPase complex.Thesis (B.?.)Honors Colleg
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