973 research outputs found
Learning to belong: Navigating liminal spaces between disciplinary and teaching identities
The continuous professional learning of academics as university teachers is a national imperative in South Africa. At our university, a Postgraduate Diploma in Education (Higher Education) was introduced in 2015 with the aim to professionalise university teaching through a formal qualification. Students (i.e., candidates) must transition in two ways: firstly, from being disciplinary specialists to being students again; and secondly, into the community of scholarly teaching in higher education. This article examines the liminality experienced by candidates as they navigate the programme and learn to belong to a new scholarly teaching community. Drawing on empirical data collected from graduates and programme coordinators, the authors track candidatesâ shifting identities and showcase how, though initially turbulent and unsettling, the process of learning to belong to a new teaching identity can be rewarding and enriching. The authors conclude by discussing the conditions required to enable candidates to acquire a strong university-teacher identity
Determinants of student satisfaction with campus residence life at a South African University
Although there are a number of studies on the determinants of general quality of life among university students, these occur mainly in developed countries and do not focus specifically on campus-based residence life. It has long been accepted that factors outside the classroom (âthe other curriculumâ) can contribute to academic success, as well as the achievement of other important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction across different racial and gender groups, for example, is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2 000 respondents. Based on descriptive analyses and ordered probit regressions, the study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One of the main findings is that there are no significant differences in satisfaction with QoRL across racial and gender groups; a finding that suggests significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction.Economic Research Southern Africa (ERSA) is a research programme funded by the National Treasury of South Africa
From pandemic disruption to post-pandemic transformation: New possibilities for teaching in South African higher education
The COVID-19 pandemic has had previously unimaginable and far-reaching effects on higher education globally (Baker et al. 2022; Cranfield et al. 2021; Kara 2021; Le Grange 2020). On top of the widespread loss felt by students and teachers across the world, we have had to make rapid changes to previously taken-for-granted ways of doing, being, learning and teaching (Baker et al. 2022; Cranfield et al. 2021). Emergency Remote Teaching and Learning (ERTL) brought constraints and opportunities, challenges and innovations. This article gives form to the statement: âthere is an opportunity in the moment for genuine equity-focused innovation in policy-making, provision and pedagogyâ (Czerniewicz et al. 2020). We use a theoretical framework of structure, culture and agency through which to view possibilities for transformation of pedagogy, and a form of semi-autoethnography as methodology. Two lecturers, one in the Humanities (Education) and one in the Life Sciences, wrote extended narratives of their experiences of ERTL and the other authors then posed a series of questions to the story authors, which elicited a set of analytic descriptions and explanations. Through iterations of this analysis, we identified two important themes: attending to studentsâ socio-emotional needs and developing studentsâ engagement, self-regulation and reflexivity. The analysis identifies key opportunities and challenges that these required and how they were addressed by the lecturers concerned. Based on the analysis and drawing on Caseâs (2015b) argument for an expanded sense of agency for students, we argue that the lecture is a key structural and cultural element of the university space that was disrupted during the pandemic and can be transformed going forward. We thus argue for decentering the lecture. Furthermore, we argue that care and concern for students has not been a primary cultural element of teaching and learning in higher education, for structural reasons, and that it should be an integral part of pedagogies going forward
Improved THETA-1 for light olefins oligomerization to diesel: Influence of textural and acidic properties
The increase in diesel demand, especially in Europe, and the need for high fuel quality requirements are forcing refiners to move into additional processes for production of high cetane diesel in order to meet the present market trends. Oligomerization of light olefins into middle distillate range products is a viable option. The fuel produced through this technology is environmentally friendly, free of sulfur and aromatics, and the adequate choice of the heterogeneous catalyst will direct the selectivity towards low branched oligomers, which will result in a high quality product. In this work we show the benefits of combining basic desilication treatments for generation of additional mesoporosity in mono-directional Theta-1 zeolite, with selective acid dealumination steps that restore not only the microporosity to values close to those of the parent samples, but also the total and strong Bronsted acidity. These modified Theta-1 zeolites present an outstanding catalytic behavior for oligomerization of propene, with a largely increased initial activity, a much higher resistance to deactivation with time on stream, and an improved selectivity to products in the diesel fraction, as compared to the original microporous Theta-1.The authors thank BP Products of North America for their financial support and permission to publish this work, and Consolider Ingenio 2010-Multicat, the "Severo Ochoa Program", and MAT2012-31657 for financial support. R. Sanchis is acknowledged for technical support.MartĂnez, C.; Doskocil, EJ.; Corma CanĂłs, A. (2014). Improved THETA-1 for light olefins oligomerization to diesel: Influence of textural and acidic properties. Topics in Catalysis. 57(6-9):668-682. https://doi.org/10.1007/s11244-013-0224-xS668682576-9Bellussi G, Mizia F, Calemma V, Pollesel P, Millini R (2012) Microporous Mesoporous Mater 164:127â134Bellussi G, Carati A, Millini R (2010) In: Cejka J, Corma A, Zones S (eds) Zeolites and Catalysis. Wiley-VCH Verlag GmbH & Co., Weinheim, pp 449â491Martinez C, Corma A (2011) Coord Chem Rev 255:1558â1580de Klerk A (2005) Ind Eng Chem Res 44:3887â3893de Klerk A (2006) Energy Fuels 20:439â445de Klerk A (2006) Energy Fuels 20:1799â1805Egloff G (1936) Ind Eng Chem Res 28:1461â1467Degnan TF Jr, Smith CM, Venkat CR (2001) Appl Catal A Gen 221:283â294Apelian MR, Boulton JR, Fung AS (1994) US5284989, to Mobil OilQuann RJ, Green LA, Tabak SA, Krambeck FJ (1988) Ind Eng Chem Res 27:565â570Tabak SA, Krambeck FJ, Garwood WE (1986) AIChE J 32:1526â1531Corma A, MartĂnez C, Doskocil EJ (2013) J Catal 300:183â196Martens JA, Ravishankar R, Mishin IE, Jacobs PE (2000) Angew Chem Int Ed Engl 39:4376â4379Martens JA, Verrelst WH, Mathys GM, Brown SH, Jacobs PA (2005) Angew Chem Int Ed Engl 117(5833â583):6Pater JPG, Jacobs PA, Martens JA (1998) J Catal 179:477â482Tabak SA (1981) US4254295, to Mobil OilOccelli ML, Hsu JT, Galya LG (1985) J Mol Catal A: Chem 32:377â390Tabak SA (1984) US4504693, to Mobil Oil CorpKholer E, Schmidt F, Wernicke HJ, Pontes MD, Roberts HL (1995, Summer) Hydrocarbon Technology InternationalMartens JA, Verduijn JP (1995) WO95/19945, to Exxon Chemical Patents Inc.Verrelst WH (1995) Martens LRM, WO95/22516, to Exxon Chemical Patents Inc.Verrelst WH, Martens LRM (2000) US6143942, to Exxon Chemical Patents Inc.Verrelst WH, Martens LRM, Verduijn JP (2006) US6013851, to Exxon Chemical Patents Inc.Dakka JM, Mathys GMK, Puttemans MPH (2003) WO03/035583 to Exxon-Mobil Chemical LimitedMatias P, Sa CC, Graca I, Lopes JM, Carvalho AP, Ramoa RF, Guisnet M (2011) Appl Catal A 399:100â109Chal R, GĂŠrardin C, Bulut M, van Donk S (2011) ChemCatChem 3:67â81Perez-Ramirez J, Christensen CH, Egeblad K, Groen JC (2008) Chem Soc Rev 37:2530â2542Verboekend D, Perez-Ramirez J (2011) Catal Sci Technol 1:879â890Serrano DP, Escola JM, Pizarro P (2013) Chem Soc Rev 42:4004â4035Verboekend D, Chabaneix AM, Thomas K, Gilson JP, Perez-Ramirez J (2011) Cryst Eng Comm 13:3408â3416Emeis CA (1993) J Catal 141:347â354Perego C, Peratello S (1999) Catal Today 52:133â145Abello S, Bonilla A, Perez-Ramirez J (2009) Appl Catal A Gen 364:191â198Corma A, Martinez C, Doskocil EJ, Yaluris G (2011) WO2011002631A2, to BP Oil International Limited. BP Corporation North America Inc., UKCorma A, Martinez C, Doskocil EJ, Yaluris G (2011) WO2011002630A2, to BP Oil International Limited. BP Corporation North America Inc, UKHan S, Heck RH, DiGuiseppi FT (1993) US5234875, to Mobil Oil CorporationPeratello S, Molinari M, Bellussi G, Perego C (1999) Catal Today 52:271â27
Effect of Extending the Original Eligibility Criteria for the CROSS Neoadjuvant Chemoradiotherapy on Toxicity and Survival in Esophageal Cancer
Patients with curable esophageal cancer (EC) who proceed beyond the original Chemoradiotherapy for Oesophageal Cancer Followed by Surgery Study (CROSS) eligibility criteria are also treated with neoadjuvant chemoradiotherapy (nCRT). This study assessed the effect that extending the CROSS eligibility criteria for nCRT has on treatment-related toxicity and overall survival (OS) in EC. The study enrolled 161 patients with locally advanced EC (T1N1-3/T2-4aN0-3/M0) treated with the CROSS schedule followed by esophagectomy. Group 1 consisted of 89 patients who met the CROSS criteria, and group 2 consisted of 72 patients who met the extended eligibility criteria, i.e. a tumor length greater than 8 cm (n = 24), more than 10% weight loss (n = 35), more than 2-4 cm extension in the stomach (n = 21), celiac lymph node metastasis (n = 13), and/or age over 75 years (n = 2). The study assessed the differences in nCRT-associated toxicity [National Cancer Institute's Common Terminology Criteria for Adverse Events (CTCAE) grade3] and 90-day postoperative mortality. Moreover, the prognostic value for OS was assessed with multivariate Cox regression analysis. No difference was found in nCRT-associated toxicity (P = 0.117), postoperative complications (P = 0.783), and 90-day mortality (P = 0.492). The OS differed significantly (P = 0.004), with a median of 37.3 months [95% confidence interval (CI), 10.4-64.2 months] for group 1 and 17.2 months (95% CI 13.8-20.7 months) for group 2. Pathologic N stage (P = 0.023), pathologic T stage (P = 0.043), and group 2 (P = 0.008) were independent prognostic factors for OS. Extension of the CROSS study eligibility criteria for nCRT did not affect nCRT-associated toxicity, postoperative complications, and postoperative mortality, but was prognostic for OS
Determinants of student satisfaction with campus residence life at a South African University
Publisher versionAlthough there are a number of studies on the determinants of general quality of life among university students, these occur mainly in developed countries and do not focus specifically on campus-based residence life. It has long been accepted that factors outside the classroom (âthe other curriculumâ) can contribute to academic success, as well as the achievement of other important outcomes such as the appreciation of human diversity. Striving towards equality of residence life satisfaction across different racial and gender groups, for example, is thus important for academic outcomes and for the development of well-functioning citizens. This study is based on the 2011 Quality of Residence Life (QoRL) Survey, conducted at a South African university, comprising roughly 2 000 respondents. Based on descriptive analyses and ordered probit regressions, the study investigates the association between satisfaction with QoRL and (i) residence milieu and characteristics, (ii) direct and indirect discrimination, (iii) perceptions of drug and alcohol issues in residence, (iv) safety, and (v) individual student characteristics. One of the main findings is that there are no significant differences in satisfaction with QoRL across racial and gender groups; a finding that suggests significant progress in university transformation and equity goals. The general atmosphere and characteristics of residences are also important predictors of QoRL satisfaction.Economic Research Southern Africa (ERSA) is a research programme funded by the National Treasury of South Africa
Resolutions of C^n/Z_n Orbifolds, their U(1) Bundles, and Applications to String Model Building
We describe blowups of C^n/Z_n orbifolds as complex line bundles over
CP^{n-1}. We construct some gauge bundles on these resolutions. Apart from the
standard embedding, we describe U(1) bundles and an SU(n-1) bundle. Both
blowups and their gauge bundles are given explicitly. We investigate ten
dimensional SO(32) super Yang-Mills theory coupled to supergravity on these
backgrounds. The integrated Bianchi identity implies that there are only a
finite number of U(1) bundle models. We describe how the orbifold gauge shift
vector can be read off from the gauge background. In this way we can assert
that in the blow down limit these models correspond to heterotic C^2/Z_2 and
C^3/Z_3 orbifold models. (Only the Z_3 model with unbroken gauge group SO(32)
cannot be reconstructed in blowup without torsion.) This is confirmed by
computing the charged chiral spectra on the resolutions. The construction of
these blowup models implies that the mismatch between type-I and heterotic
models on T^6/Z_3 does not signal a complication of S-duality, but rather a
problem of type-I model building itself: The standard type-I orbifold model
building only allows for a single model on this orbifold, while the blowup
models give five different models in blow down.Comment: 1+27 pages LaTeX, 2 figures, some typos correcte
Biliary tract visualization using near-infrared imaging with indocyanine green during laparoscopic cholecystectomy: results of a systematic review
Contains fulltext :
174508.pdf (publisher's version ) (Open Access)BACKGROUND: Near-infrared imaging with indocyanine green (ICG) has been extensively investigated during laparoscopic cholecystectomy (LC). However, methods vary between studies, especially regarding patient selection, dosage and timing. The aim of this systematic review was to evaluate the potential of the near-infrared imaging technique with ICG to identify biliary structures during LC. METHODS: A comprehensive systematic literature search was performed. Prospective trials examining the use of ICG during LC were included. Primary outcome was biliary tract visualization. Risk of bias was assessed using ROBINS-I. Secondly, a meta-analysis was performed comparing ICG to intraoperative cholangiography (IOC) for identification of biliary structures. GRADE was used to assess the quality of the evidence. RESULTS: Nineteen studies were included. Based upon the pooled data from 13 studies, cystic duct (Lusch et al. in J Endourol 28:261-266, 2014) visualization was 86.5% (95% CI 71.2-96.6%) prior to dissection of Calot's triangle with a 2.5-mg dosage of ICG and 96.5% (95% CI 93.9-98.4%) after dissection. The results were not appreciably different when the dosage was based upon bodyweight. There is moderate quality evidence that the CD is more frequently visualized using ICG than IOC (RR 1.16; 95% CI 1.00-1.35); however, this difference was not statistically significant. CONCLUSION: This systematic review provides equal results for biliary tract visualization with near-infrared imaging with ICG during LC compared to IOC. Near-infrared imaging with ICG has the potential to replace IOC for biliary mapping. However, methods of near-infrared imaging with ICG vary. Future research is necessary for optimization and standardization of the near-infrared ICG technique
Experimental Mycobacterium bovis infection in three white rhinoceroses (Ceratotherium simum):Susceptibility, clinical and anatomical pathology
Tuberculosis caused by Mycobacterium bovis is endemic in the African buffalo (Syncerus caffer) population in the Kruger National Park and other conservation areas in South Africa. The disease has been diagnosed in a total of 21 free ranging or semi-free ranging wildlife species in the country with highly variable presentations in terms of clinical signs as well as severity and distribution of tuberculous lesions. Most species are spillover or dead-end hosts without significant role in the epidemiology of the disease. White rhinoceroses (Ceratotherium simum) are translocated from the Kruger National Park in substantial numbers every year and a clear understanding of their risk to manifest overt tuberculosis disease and to serve as source of infection to other species is required. We report the findings of experimental infection of three white rhinoceroses with a moderately low dose of a virulent field isolate of Mycobacterium bovis. None of the animals developed clinical signs or disseminated disease. The susceptibility of the white rhinoceros to bovine tuberculosis was confirmed by successful experimental infection based on the ante mortem isolation of M. bovis from the respiratory tract of one rhinoceros, the presence of acid-fast organisms and necrotizing granulomatous lesions in the tracheobronchial lymph nodes and the detection of M. bovis genetic material by PCR in the lungs of two animals
Clinical review: Humidifiers during non-invasive ventilation - key topics and practical implications
Inadequate gas conditioning during non-invasive ventilation (NIV) can impair the anatomy and function of nasal mucosa. The resulting symptoms may have a negative effect on patients' adherence to ventilatory treatment, especially for chronic use. Several parameters, mostly technical aspects of NIV, contribute to inefficient gas conditioning. Factors affecting airway humidity during NIV include inspiratory flow, inspiratory oxygen fraction, leaks, type of ventilator, interface used to deliver NIV, temperature and pressure of inhaled gas, and type of humidifier. The correct application of a humidification system may avoid the effects of NIV-induced drying of the airway. This brief review analyses the consequences of airway dryness in patients receiving NIV and the technical tools necessary to guarantee adequate gas conditioning during ventilatory treatment. Open questions remain about the timing of gas conditioning for acute or chronic settings, the choice and type of humidification device, the interaction between the humidifier and the underlying disease, and the effects of individual humidification systems on delivered humidity
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