105 research outputs found

    An examination into the role of a peer academic online mentoring programme during Emergency Remote Teaching at a South African residential university

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    For residential universities, the COVID-19 pandemic in the 2020 academic year necessitated the suspension of in-person lectures and a swift transition of classes and other in-person activities to emergency remote teaching (ERT). This included the academic module mentoring programme, cognisant of the potential challenges experienced by first-year students during a period of ERT. The role of an in-person module mentoring programme before ERT was only to provide academic support to first-year students within an introductory financial accounting module to promote student success. This study investigated the role of an academic online mentoring programme for students in an introductory financial accounting module during ERT. A web-based survey was conducted to source the perceptions of both mentors and mentees who participated in an introductory module academic mentoring programme both before and during ERT to analyse whether the role of the academic module mentoring programme had shifted beyond that of academic support in an ERT environment. While academic support remained at the forefront as the main perceived benefit of the online mentoring programme, with the transition to ERT, the findings of this study illustrate an altering role that is more inclusive of additional psychological and peer support and engagement perceived benefits for first-year students who participated in an academic mentoring programme for students in an introductory financial accounting module during a period of ERT. Understanding student perceptions of the value derived for first-year students from an academic online mentoring programme is important in understanding first-year student needs and to provide relevant and applicable training to first-year students to promote student success during ERT. The findings of this study provide insight to institutions and in considering the addition of academic interventions such as offering academic online mentoring programmes during ERT and highlight the perceived value-add from both a mentor and mentee perspective

    Correction: Delayed Goblet Cell Hyperplasia, Acetylcholine Receptor Expression, and Worm Expulsion in SMC-Specific IL-4RĪ±ā€“Deficient Mice

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    Interleukin 4 receptor alpha (IL-4Ralpha) is essential for effective clearance of gastrointestinal nematode infections. Smooth muscle cells are considered to play a role in the type 2 immune response-driven expulsion of gastrointestinal nematodes. Previous studies have shown in vitro that signal transducer and activator of transcription 6 signaling in response to parasitic nematode infection significantly increases smooth muscle cell contractility. Inhibition of the IL-4Ralpha pathway inhibits this response. How this response manifests itself in vivo is unknown. In this study, smooth muscle cell IL-4Ralpha-deficient mice (SM-MHC(Cre)IL-4Ralpha(-/lox)) were generated and characterized to uncover any role for IL-4/IL-13 in this non-immune cell type in response to Nippostrongylus brasiliensis infection. IL-4Ralpha was absent from alpha-actin-positive smooth muscle cells, while other cell types showed normal IL-4Ralpha expression, thus demonstrating efficient cell-type-specific deletion of the IL-4Ralpha gene. N. brasiliensis-infected SM-MHC(Cre)IL-4Ralpha(-/lox) mice showed delayed ability to resolve infection with significantly prolonged fecal egg recovery and delayed worm expulsion. The delayed expulsion was related to a delayed intestinal goblet cell hyperplasia, reduced T helper 2 cytokine production in the mesenteric lymph node, and reduced M3 muscarinic receptor expression during infection. Together, these results demonstrate that in vivo IL-4Ralpha-responsive smooth muscle cells are beneficial for N. brasiliensis expulsion by coordinating T helper 2 cytokine responses, goblet hyperplasia, and acetylcholine responsiveness, which drive smooth muscle cell contractions

    Grain structure orientational change in Ti6Al4V alloys induced by sea water quenching and novel stress relief annealing process

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    We report on the microstructures and properties of Ti6Al4V alloys, which were achieved upon quenching in sea water medium with potential high cooling rate. The Ti6Al4V alloys were quenched at 1000 and 1100 ā—¦C, respectively. Moreover, the effect of post-quenching annealing performed at 900 ā—¦C was analyzed. As a result, the quenched alloy experienced surface thermal stress, due to rapid cooling and thermal shock, due to exposure to high temperature annealing

    Thermally Induced Nano-Structural and Optical Changes of nc-Si:H Deposited by Hot-Wire CVD

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    We report on the thermally induced changes of the nano-structural and optical properties of hydrogenated nanocrystalline silicon in the temperature range 200ā€“700 Ā°C. The as-deposited sample has a high crystalline volume fraction of 53% with an average crystallite size of ~3.9 nm, where 66% of the total hydrogen is bonded as ā‰”Siā€“H monohydrides on the nano-crystallite surface. A growth in the native crystallite size and crystalline volume fraction occurs at annealing temperatures ā‰„400 Ā°C, where hydrogen is initially removed from the crystallite grain boundaries followed by its removal from the amorphous network. The nucleation of smaller nano-crystallites at higher temperatures accounts for the enhanced porous structure and the increase in the optical band gap and average gap

    Undiagnosed comorbidities among individuals hospitalised with COVID-19 in South African public hospitals

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    Background. Previous studies have reported comorbid disease, including hypertension, diabetes mellitus, chronic cardiac and renal disease, malignancy, HIV, tuberculosis (TB) and obesity, to be associated with COVIDā€‘19 mortality. National demographic surveys have reported a high proportion of undiagnosed and untreated comorbid disease in South Africa (SA). Objectives. To determine the number of individuals with previously undiagnosed HIV, TB and non-communicable diseases (NCDs) among patients hospitalised with COVIDā€‘19, and the level of medical control of these chronic diseases. Methods. We conducted a sentinel surveillance study to collect enhanced data on HIV, TB and NCDs among individuals with COVIDā€‘19 admitted to 16 secondary-level public hospitals in six of the nine provinces of SA. Trained surveillance officers approached all patients who met the surveillance case definition for inclusion in the study, and consenting patients were enrolled. The data collection instrument included questions on past medical history to determine the self-reported presence of comorbidities. The results of clinical and laboratory testing introduced as part of routine clinical care for hospitalised COVIDā€‘19 patients were collected for the study, to objectively determine the presence of hypertension, diabetes, HIV and TB and the levels of control of diabetes and HIV. Results. On self-reported history, the most prevalent comorbidities were hypertension (n=1 658; 51.5%), diabetes (n=855; 26.6%) and HIV (n=603; 18.7%). The prevalence of self-reported active TB was 3.1%, and that of previous TB 5.5%. There were 1 254 patients admitted with COVIDā€‘19 (39.0%) who met the body mass index criteria for obesity. On clinical and laboratory testing, 87 patients were newly diagnosed with HIV, 29 with TB, 215 with diabetes and 40 with hypertension during their COVIDā€‘19 admission. There were 151/521 patients living with HIV (29.0%) with a viral load >1 000 copies/mL and 309/570 (54.2%) with a CD4 count <200 cells/Ī¼L. Among 901 patients classified as having diabetes, 777 (86.2%) had a glycated haemoglobin (HbA1c) level ā‰„6.5%. Conclusion. The study revealed a high prevalence of comorbid conditions among individuals with COVIDā€‘19 admitted to public hospitals in SA. In addition, a significant number of patients had previously undiagnosed hypertension, diabetes, HIV and active TB, and many and poorly controlled chronic disease, as evidenced by high HbA1c levels in patients with diabetes, and high viral loads and low CD4 levels in patients with HIV. The findings highlight the importance of strengthening health systems and care cascades for chronic disease management, which include prevention, screening for and effectively treating comorbidities, and ensuring secure and innovative supplies of medicines in primary healthcare during the COVIDā€‘19 pandemic

    Evaluation of encapsulated liver cell spheroids in a fluidised-bed bioartificial liver for treatment of ischaemic acute liver failure in pigs in a translational setting.

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    Liver failure is an increasing problem. Donor-organ shortage results in patients dying before receiving a transplant. Since the liver can regenerate, alternative therapies providing temporary liver-support are sought. A bioartificial-liver would temporarily substitute function in liver failure buying time for liver regeneration/organ-procurement. Our aim: to develop a prototype bioartificial-liver-machine (BAL) comprising a human liver-derived cell-line, cultured to phenotypic competence and deliverable in a clinical setting to sites distant from its preparation. The objective of this study was to determine whether its use would improve functional parameters of liver failure in pigs with acute liver failure, to provide proof-of-principle. HepG2cells encapsulated in alginate-beads, proliferated in a fluidised-bed-bioreactor providing a biomass of 4-6Ɨ10(10)cells, were transported from preparation-laboratory to point-of-use operating theatre (6000miles) under perfluorodecalin at ambient temperature. Irreversible ischaemic liver failure was induced in anaesthetised pigs, after portal-systemic-shunt, by hepatic-artery-ligation. Biochemical parameters, intracranial pressure, and functional-clotting were measured in animals connected in an extracorporeal bioartificial-liver circuit. Efficacy was demonstrated comparing outcomes between animals connected to a circuit containing alginate-encapsulated cells (Cell-bead BAL), and those connected to circuit containing alginate capsules without cells (Empty-bead BAL). Cells of the biomass met regulatory standards for sterility and provenance. All animals developed progressive liver-failure after ischaemia induction. Efficacy of BAL was demonstrated since animals connected to a functional biomass (+ cells) had significantly smaller rises in intracranial pressure, lower ammonia levels, more bilirubin conjugation, improved acidosis and clotting restoration compared to animals connected to the circuit without cells. In the +cell group, human proteins accumulated in pigs' plasma. Delivery of biomass using a short-term cold-chain enabled transport and use without loss of function over 3days. Thus, a fluidised-bed bioreactor containing alginate-encapsulated HepG2cell-spheroids improved important parameters of acute liver failure in pigs. The system can readily be up-scaled and transported to point-of-use justifying development at clinical scale

    LensWatch: I. Resolved HST Observations and Constraints on the Strongly-Lensed Type Ia Supernova 2022qmx ("SN Zwicky")

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    Supernovae (SNe) that have been multiply-imaged by gravitational lensing are rare and powerful probes for cosmology. Each detection is an opportunity to develop the critical tools and methodologies needed as the sample of lensed SNe increases by orders of magnitude with the upcoming Vera C. Rubin Observatory and Nancy Grace Roman Space Telescope. The latest such discovery is of the quadruply-imaged Type Ia SN 2022qmx (aka, "SN Zwicky"; Goobar et al. 2022) at z = 0.3544. SN Zwicky was discovered by the Zwicky Transient Facility (ZTF) in spatially unresolved data. Here we present follow-up Hubble Space Telescope observations of SN Zwicky, the first from the multi-cycle "LensWatch" program (www.lenswatch.org). We measure photometry for each of the four images of SN Zwicky, which are resolved in three WFC3/UVIS filters (F475W, F625W, F814W) but unresolved with WFC3/IR F160W, and produce an analysis of the lensing system using a variety of independent lens modeling methods. We find consistency between time delays estimated with the single epoch of HST photometry and the lens model predictions constrained through the multiple image positions, with both inferring time delays of <1 day. Our lens models converge to an Einstein radius of (0.168+0.009-0.005)", the smallest yet seen in a lensed SN. The "standard candle" nature of SN Zwicky provides magnification estimates independent of the lens modeling that are brighter by ~1.5 mag and ~0.8 mag for two of the four images, suggesting significant microlensing and/or additional substructure beyond the flexibility of our image-position mass models

    Delayed Goblet Cell Hyperplasia, Acetylcholine Receptor Expression, and Worm Expulsion in SMC-Specific IL-4RĪ±ā€“Deficient Mice

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    Interleukin 4 receptor Ī± (IL-4RĪ±) is essential for effective clearance of gastrointestinal nematode infections. Smooth muscle cells are considered to play a role in the type 2 immune responseā€“driven expulsion of gastrointestinal nematodes. Previous studies have shown in vitro that signal transducer and activator of transcription 6 signaling in response to parasitic nematode infection significantly increases smooth muscle cell contractility. Inhibition of the IL-4RĪ± pathway inhibits this response. How this response manifests itself in vivo is unknown. In this study, smooth muscle cell IL-4RĪ±ā€“deficient mice (SM-MHC(Cre)IL-4RĪ±(āˆ’/lox)) were generated and characterized to uncover any role for IL-4/IL-13 in this nonā€“immune cell type in response to Nippostrongylus brasiliensis infection. IL-4RĪ± was absent from Ī±-actinā€“positive smooth muscle cells, while other cell types showed normal IL-4RĪ± expression, thus demonstrating efficient cell-typeā€“specific deletion of the IL-4RĪ± gene. N. brasiliensisā€“infected SM-MHC(Cre)IL-4RĪ±(āˆ’/lox) mice showed delayed ability to resolve infection with significantly prolonged fecal egg recovery and delayed worm expulsion. The delayed expulsion was related to a delayed intestinal goblet cell hyperplasia, reduced T helper 2 cytokine production in the mesenteric lymph node, and reduced M3 muscarinic receptor expression during infection. Together, these results demonstrate that in vivo IL-4RĪ±ā€“responsive smooth muscle cells are beneficial for N. brasiliensis expulsion by coordinating T helper 2 cytokine responses, goblet hyperplasia, and acetylcholine responsiveness, which drive smooth muscle cell contractions

    The Young Supernova Experiment: Survey Goals, Overview, and Operations

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    Time domain science has undergone a revolution over the past decade, with tens of thousands of new supernovae (SNe) discovered each year. However, several observational domains, including SNe within days or hours of explosion and faint, red transients, are just beginning to be explored. Here, we present the Young Supernova Experiment (YSE), a novel optical time-domain survey on the Pan-STARRS telescopes. Our survey is designed to obtain well-sampled grizgriz light curves for thousands of transient events up to zā‰ˆ0.2z \approx 0.2. This large sample of transients with 4-band light curves will lay the foundation for the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope, providing a critical training set in similar filters and a well-calibrated low-redshift anchor of cosmologically useful SNe Ia to benefit dark energy science. As the name suggests, YSE complements and extends other ongoing time-domain surveys by discovering fast-rising SNe within a few hours to days of explosion. YSE is the only current four-band time-domain survey and is able to discover transients as faint āˆ¼\sim21.5 mag in grigri and āˆ¼\sim20.5 mag in zz, depths that allow us to probe the earliest epochs of stellar explosions. YSE is currently observing approximately 750 square degrees of sky every three days and we plan to increase the area to 1500 square degrees in the near future. When operating at full capacity, survey simulations show that YSE will find āˆ¼\sim5000 new SNe per year and at least two SNe within three days of explosion per month. To date, YSE has discovered or observed 8.3% of the transient candidates reported to the International Astronomical Union in 2020. We present an overview of YSE, including science goals, survey characteristics and a summary of our transient discoveries to date.Comment: ApJ, in press; more information at https://yse.ucsc.edu
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