62 research outputs found

    Laparoscopic pyeloplasty for ureteropelvic junction obstruction of the lower moiety in a completely duplicated collecting system: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>There are only a few reports on laparoscopic pyeloplasty in kidney abnormalities and only one case for laparoscopic pyeloplasty in a duplicated system. Increasing experience in laparoscopic techniques allows proper treatment of such anomalies. However, its feasibility in difficult cases with altered kidney anatomy such as that of duplicated renal pelvis still needs to be addressed.</p> <p>Case presentation</p> <p>We present a case of a 22-year-old white Caucasian female patient with ureteropelvic junction obstruction of the lower ureter of a completely duplicated system that was managed with laparoscopic pyeloplasty. Crossing vessels were identified and transposed. The procedure was carried out successfully and the patient's symptoms subsided. Follow-up studies demonstrated complete resolution of the obstruction.</p> <p>Conclusion</p> <p>Since laparoscopic pyeloplasty is still an evolving procedure, its feasibility in complex cases of kidney anatomic abnormalities is herein further justified.</p

    (Reinforcing) factors influencing a physical education teachers use of the direct instruction model teaching games

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    he purpose of this study was to explore how a physical education (PE) teacher employed the direct instruction model (DIM) teaching games in a United Kingdom secondary school. The research sought to identify how the teacher utilised the DIM and those factors that influenced his use of the model. Occupational socialization was used to identify the factors that encouraged his use of the DIM. Data were collected from interviews and lesson observations. Inductive data analysis showed that while the teacher presented a ‘full version’ of the DIM, his limited content knowledge impacted on the use of the model in teaching cricket. Factors influencing his use of the model were a sporting perspective, a Post Graduate Certificate in Education mentor and the ability and behaviour of the students. These factors reinforced his undergraduate learning and subsequent use of the DIM. It is suggested that the comparable backgrounds of many PE student teachers may make the DIM an apt model to learn in undergraduate and postgraduate PE courses. However, effective use of the model requires students to be taught and to possess in-depth content knowledge of the game(s)/activities being taught and learned

    Are pre-service teachers’ beliefs toward curricular outcomes challenged by teaching methods modules and school placement? Evidence from three Greek physical education faculties

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    Current research on physical education teacher education (PETE) has shown that pre-service teachers’ beliefs concerning the scope of physical education (PE) remain highly influential during their studies. However, undergraduate programmes seem to have a limited effect on pre-service teachers’ teaching priorities, and this situation is left unchallenged. Therefore, the aim of the present study was to examine the impact of two PE teaching methods modules, which included school placement experiences, over one academic year, on pre-service PE teachers’ belief systems towards four important curricular outcomes. A total of 373 undergraduate pre-service teachers (238 males, 135 females; mean = 21.02, standard deviation = 2.33 years) from three major Greek faculties of PE and sport science twice completed a previously validated four-factor instrument. The results indicated that pre-service teachers shared some similar beliefs about the outcome goals of PE, as they all classified physical activity and fitness as the most important one. The teaching methods modules had a positive impact on their beliefs, which were reinforced; however, their classification did not change over time. Both teaching- and coaching-oriented pre-service teachers classified the curricular outcomes in an identical way. Data suggested that PETE recruits prioritized the fitness learning outcomes, and this was in alignment with utilitarian approaches proposed recently in PE, which forward measurable PE learning outcomes. Also, participants preferred to hold and reinforce their personal belief structures and were not willing to change them, complying with faculty staff dispositions. Implications of these findings and recommendations for more effective school placement experiences are discussed. © The Author(s) 2019

    The impact of occupational socialization on physical education pre-service teachers’ beliefs about four important curricular outcomes: A cross-sectional study

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    Most national Physical Education (PE) curriculums worldwide are based on a variety of outcome goals. The most important are physical activity and fitness, self-actualization, motor skill development and social development. Capturing PE Teacher Education pre-service teachers’ beliefs toward these outcomes may offer a useful insight into the process of identifying and understanding prospective teachers’ decisions and actions. The aim of the current study was to compare PE pre-service teachers’ beliefs regarding four important outcome goals, according to year in university, athletic background and occupational orientation. A total of 483 undergraduate pre-service teachers from a Greek faculty of PE completed a previously validated four factor instrument. Significant differences were observed in the four outcome goals beliefs between pre-service teachers in different years of studies and between teaching and coaching oriented pre-service teachers. No differences were found between pre-service teachers with different athletic backgrounds. Findings suggested that sport participation per se did not affect outcome beliefs toward a specific direction and all pre-service teachers rated higher the physical activity and fitness goal. Participants with a teaching orientation rated higher three of the four outcome goals than their coaching oriented counterparts. Furthermore, third year field-based experiences had a positive impact on pre-service teachers’ beliefs, while the fourth year of studies and the coaching specializations contributed to a beliefs ‘washout effect’. Recommendations arise from previous and present findings regarding the faculty’s undergraduate programme and we propose that future studies build on this research by continuing to examine PE students’ and teachers’ beliefs more thoroughly. © The Author(s) 2015

    Beyond microcystins: Cyanobacterial extracts induce cytoskeletal alterations in rice root cells

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    Microcystins (MCs) are cyanobacterial toxins and potent inhibitors of protein phosphatases 1 (PP1) and 2A (PP2A), which are involved in plant cytoskeleton (microtubules and F-actin) organization. Therefore, studies on the toxicity of cyanobacterial products on plant cells have so far been focused on MCs. In this study, we investigated the effects of extracts from 16 (4 MC-producing and 12 non-MC-producing) cyanobacterial strains from several habitats, on various enzymes (PP1, trypsin, elastase), on the plant cytoskeleton and H2O2 levels in Oryza sativa (rice) root cells. Seedling roots were treated for various time periods (1, 12, and 24 h) with aqueous cyanobacterial extracts and underwent either immunostaining for α-tubulin or staining of F-actin with fluorescent phalloidin. 2,7-dichlorofluorescein diacetate (DCF-DA) staining was performed for H2O2 imaging. The enzyme assays confirmed the bioactivity of the extracts of not only MC-rich (MC+), but also MC-devoid (MC−) extracts, which induced major time-dependent alterations on both components of the plant cytoskeleton. These findings suggest that a broad spectrum of bioactive cyanobacterial compounds, apart from MCs or other known cyanotoxins (such as cylindrospermopsin), can affect plants by disrupting the cytoskeleton. © 2020 by the authors

    Aberrant microtubule organization in dividing root cells of p60-katanin mutants

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    Aberrant microtubule organization has been recently recorded in dividing root cells of fra2 and lue1 p60-katanin Arabidopsis thaliana mutants. Here, we report similar defects in the bot1 and ktn1-2 mutants of the same plant, proposing that they constitute a consistent phenotype of p60-katanin mutants. In addition, we show that the Targeting Protein for Xklp2 (TPX2) protein co-localizes with microtubules on the surface of prophase nuclei of the mutants, probably participating in multipolar spindle assembly. As microtubule organization defects are not observed in metaphase/anaphase spindles and initiating phragmoplasts, we also discuss the putative association of the observed aberrations with the nuclear envelope and we emphasize on the mechanism of bipolar metaphase spindle organization in the mutants. It seems that chromosome-mediated spindle assembly, probably minimally dependent on microtubule severing by p60-katanin, dominates after nuclear envelope breakdown, restoring bipolarity

    Evaluation of the spatiotemporal effects of bisphenol A on the leaves of the seagrass Cymodocea nodosa

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    The organic pollutant bisphenol A (BPA) causes adverse effects on aquatic biota. The present study explored the toxicity mechanism of environmentally occurring BPA concentrations (0.03–3 μg L−1) on the seagrass Cymodocea nodosa intermediate leaf photosynthetic machinery. A “mosaic” type BPA effect pattern was observed, with “unaffected” and “affected”” leaf areas. In negatively affected leaf areas cells had a dark appearance and lost their chlorophyll auto-fluorescence, while hydrogen peroxide (H2O2) content increased time-dependently. In the “unaffected” leaf areas, cells exhibited increased phenolic compound production. At 1 μg L−1 of BPA exposure, there was no effect on the fraction of open reaction centers (qP) compared to control and also no significant effect on the quantum yield of non-regulated non-photochemical energy loss in PSII (ΦΝΟ). However, a 3 μg L−1 BPA application resulted in a significant ΦΝΟ increase, even from the first exposure day. Ultrastructural observations revealed electronically dense damaged thylakoids in the plastids, while effects on Golgi dictyosomes and the endoplasmic reticulum were also observed at 3 μg L−1 BPA. The up-regulated H2O2 BPA-derived production seems to be a key factor causing both oxidative damages but probably also triggering retrograde signalling, conferring tolerance to BPA in the “unaffected” leaf areas. © 2020 Elsevier B.V

    Spatial heterogeneity of cadmium effects on salvia sclarea leaves revealed by chlorophyll fluorescence imaging analysis and laser ablation inductively coupled plasma mass spectrometry

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    In this study, for a first time (according to our knowledge), we couple the methodologies of chlorophyll fluorescence imaging analysis (CF-IA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), in order to investigate the effects of cadmium (Cd) accumulation on photosystem II (PSII) photochemistry. We used as plant material Salvia sclarea that grew hydroponically with or without (control) 100 μM Cd for five days. The spatial heterogeneity of a decreased effective quantum yield of electron transport (ΦPSII) that was observed after exposure to Cd was linked to the spatial pattern of high Cd accumulation. However, the high increase of non-photochemical quenching (NPQ), at the leaf part with the high Cd accumulation, resulted in the decrease of the quantum yield of non-regulated energy loss (ΦNO) even more than that of control leaves. Thus, S. sclarea leaves exposed to 100 μM Cd exhibited lower reactive oxygen species (ROS) production as singlet oxygen (1O2). In addition, the increased photoprotective heat dissipation (NPQ) in the whole leaf under Cd exposure was sufficient enough to retain the same fraction of open reaction centers (qp) with control leaves. Our results demonstrated that CF-IA and LA-ICP-MS could be successfully combined to monitor heavy metal effects and plant tolerance mechanisms. © 2019 by the authors
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