273 research outputs found

    Supporting the reflective practice of tutors: what do tutors reflect on?

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    Effective self-reflection is a key component of excellent teaching. We describe the types of self-reflection identified in tutors’ reflective statements following a peer observation of teaching exercise. We used an adapted version of the categories developed by Grushka et al. (2005) to code text from 20 written statements as technical (26% of comments), practical (36% of comments) and critical (33% of comments). Tutors also wrote about the affective aspects of the exercise and the majority of such comments were positive. Most tutors reflected in a holistic way about their teaching, noting the importance of getting the technical aspects right while also being concerned about pedagogical matters and issues beyond the classroom. The exercise was an effective way to prompt tutors to reflect on their teaching and helped tutors articulate and formalise their learning from the peer observation activity. Suggestions for further exploration of the reflective practice of tutors are provided

    Quality assessment, antimicrobial activity organic sunflower honey and use of Maldi-tof mass spectrometry for the identification bacteria isolated from honey

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    The aim of this study was to investigate the physicochemical parameters of quality, microbiological safety and antimicrobial potential of four samples of organic sunflower honey from the Banat area (northeastern Serbia). Humidity, ash, pH, free acidity, electrical conductivity, hydroxymethylfurfural content, sugar content and diastase activity were measured. Microbiological analysis revealed the presence of total aerobic mesophilic bacteria, coliforms, aerobic endospores, lactic acid bacteria (LAB) and a good number of molds and yeasts. The isolate identification was carried out using Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The antimicrobial effect of organic sunflower honey was investigated on five ATCC strains of bacteria: Staphilococcus aureus ATCC 29213; Escherichia coli ATCC 25922; Salmonella enterica ATCC 10708; Yersinia enterocolitica ATCC 23715; and Bacillus subtilis ATCC 23857. The results of the study showed that all honey samples meet international quality standards for all physicochemical parameters. Microbiological analysis of Sunflower honey confirmed the total bacterial counts for all samples ranged from1.80 to 1.85 x10-2cfu/g-1, whereby no presence Clostridium spp., coliform bacteria, as well as molds was detected. Investigation of the antimicrobial activity of honey samples revealed that all bacteria showed clear zones of inhibition in honey concentrations of 40-100%, which is a satisfactory result for flower honey

    Criteria Selection for the Assessment of Serbian Lignites Tendency to Form Deposits on Power Boilers Heat Transfer Surfaces

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    Based on investigations of ash deposit formation, semi-empirical indicators for slagging and fouling, based on ash chemical composition and its fusion temperature, have been determined These criteria-indicators, in suggested limits, describe the coals on which they are based (North-American and British) well. However, the experience in the thermal power production sector of Serbia shows that their literal application to domestic coals does not produce satisfactory results. This contribution provides an analysis of applicability and the choice of criteria that are suitable for Serbian coals. The focus of the contribution is on coal slagging indicators, since slagging has much heavier consequences on heat transfer inside the steam boiler, and on boiler operation as a whole. The basis for the analysis of chosen criteria comprises of the results of investigations of four coalfields - Kostolac, Kolubara, Kosovo (Serbia), and Ugljevik (Bosnia and Herzegovina)

    Exact/heuristic hybrids using rVNS and hyperheuristics for workforce scheduling

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    In this paper we study a complex real-world workforce scheduling problem. We propose a method of splitting the problem into smaller parts and solving each part using exhaustive search. These smaller parts comprise a combination of choosing a method to select a task to be scheduled and a method to allocate resources, including time, to the selected task. We use reduced Variable Neighbourhood Search (rVNS) and hyperheuristic approaches to decide which sub problems to tackle. The resulting methods are compared to local search and Genetic Algorithm approaches. Parallelisation is used to perform nearly one CPU-year of experiments. The results show that the new methods can produce results fitter than the Genetic Algorithm in less time and that they are far superior to any of their component techniques. The method used to split up the problem is generalisable and could be applied to a wide range of optimisation problems

    Tumor response and patient outcome after preoperative radiotherapy in locally advanced non-inflammatory breast cancer patients

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    Purpose: The purpose of this analysis was to assess the tumor response and long-term outcome in patients treated with preoperative radiotherapy (PRT) without systemic therapy. Methods: Between 1997 and 2000, 134 patients with non-inflammatory locally advanced breast cancer (LABC) were treated with PRT. The tumor dose was 45 Gy in 15 fractions to the breast and to regional lymph nodes over 6 weeks. Radical mastectomy was performed 6 weeks after PRT to all patients and adjuvant systemic therapy was administered as per protocol. The measures of disease outcome were overall survival (OS) and disease-free survival (DFS) which estimated using the Kaplan-Meier method. Results: Median follow-up was 74 months (range 4-216). Objective clinical tumor response after PRT was observed in 77.6% of the patients. Clinical complete tumor response (cCR) was achieved in 21.6% of the patients. Pathological CR in the breast was achieved in 15% of the patients. The 5- and 10-year OS were 55.1 and 37.8%, respectively. The 5- and 10-year DFS were 39.2 and 27%, respectively. Patients who achieved cCR had significantly longer OS in comparison with patients achieving clinical partial response (cPR) and clinical stable disease (cSD). Similarly, DFS of patients in the cCR group was longer compared with patients with cPR and cSD, yet without statistical significance. Conclusions: Our results showed that local control in LABC patients achieved by primary PRT, followed by radical mastectomy was comparable with the results reported in the literature. Complete pathologic response to PRT identified a subgroup of patients with a trend toward better DFS and OS

    A Classification of Hyper-heuristic Approaches

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    The current state of the art in hyper-heuristic research comprises a set of approaches that share the common goal of automating the design and adaptation of heuristic methods to solve hard computational search problems. The main goal is to produce more generally applicable search methodologies. In this chapter we present and overview of previous categorisations of hyper-heuristics and provide a unified classification and definition which captures the work that is being undertaken in this field. We distinguish between two main hyper-heuristic categories: heuristic selection and heuristic generation. Some representative examples of each category are discussed in detail. Our goal is to both clarify the main features of existing techniques and to suggest new directions for hyper-heuristic research
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