First Records of Trichodinid Ectoparasites (Ciliophora: Peritrichia) from Introduced Freshwater Fishes in Tasmania, Australia, with Comments on Pathogenicity

During parasitological surveys in Tasmania (Australia), four introduced fish species were investigated for the presence of trichodinid ectoparasites. Five trichodinid species were found on the skin, fins and gills of two of these fishes, i.e. the tench Tinca tinca Linnaeus, 1758 and the red fin perch Perca fluviatillis Linnaeus, 1758. Four trichodinids are known species for which comparative descriptions are provided, i.e. Trichodina acuta Lom, 1961, T. esocis Lom, 1961, T. lepsii Lom, 1962 and Trichodinella epizootica (Raabe 1950) Šrámek- Hušek, 1953. A fifth species, i.e. Trichodina tunnae sp. n. is described as a new species from the red fin perch. All species are described using silver impregnated and hematoxylin stained specimens

Trichodinids (Ciliophora) of corydoras paleatus (siluriformes) and jenynsia multidentata (cyprinodontiformes) from Argentina, with description of trichodina corydori n. sp. and trichodina jenynsii n. sp

During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombón River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp. were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370-380°. Trichodina jenynsii is characterized by curved blades and prominentlyshaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.Fil: Marcotegui, Paula Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Basson, Linda. University of the Free State; SudáfricaFil: Martorelli, Sergio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentin

INCREASING ENGAGEMENT IN ONLINE LEARNING

Motivated by the need to improve students’ engagement and learning outcomes, in 2018/2019 we implemented two engagement interventions to 1650 students in twelve online courses across Science, Education, Engineering and Accounting at a regional university. Both “click” data and video analytics were used to measure engagement. The first initiative applied findings from behavioural research to ‘nudge’ students toward early engagement with key learning resources and to create ‘teaching presence’ (Garrison, 2007). The second initiative was to help move ‘knowledge’ to ‘know-how’ by nudging videos to offer a sense of real-life expertise, application, motivation and advanced connection. We aimed to improve student learning outcomes and their online engagement by providing explicit guidance about which course resources were critical for students’ success. We were interested in interrogating the data in both learning management systems (Moodle®) and Video analytics (Vimeo®) to answer questions about learner engagement and to explore evidence of impact. The nudges successfully engaged students in the key online resources showing an 18% average increase in access and confirmed via student feedback. The project developed a Nudge Guidelines document that has been presented institutionally and nationally to enable academics to utilise the strategies in their courses

Binary Fission, Telotroch Formation and Conjugation in Mantoscyphidia Jankowski, 1980 (Ciliophora: Peritrichia)

Mantoscyphidians occur in high numbers on the gills of South African Haliotis and limpet species. This provided the ideal opportunity to study asexual and sexual reproduction, for the first time in different African Mantoscyphidia Jankowski, 1985 populations. Descriptions of the reproductive processes found in scyphidiid peritrichs were until now, mostly based on line drawings. Scanning electronand light microscopy contributed uniquely, in providing detail information regarding binary fission, telotroch formation and conjugation. Mantoscyphidia spadiceae Botes, Basson and Van As, 2001 shed the most light on binary fission. Micronuclear division occurred first with the plane of fission already evident and macronuclear cleavage ended just before final separation took place. Fission is not complete until a small string of pellicle that joins the daughter cells finally separates. Information on telotroch development was gathered from M. branchi Van As, Basson and Van As, 1998 and M. spadiceae populations. Telotrochs were between 36.7 and 38.6% shorter than live, extended mantoscyphidians and their swimming action resembled mobiline peritrichs. Mantoscyphidia branchi populations also proved to be most useful for conjugation studies. Conjugation included three progamic nuclear divisions and preceded synkaryon formation and two metagamic nuclear divisions. The process required 24 hours to be completed

Comparative exploration of the morphological plasticity of Trichodina centrostrigeata (Peritrichia: Mobilida), ectoparasite from the gills of two tilapia species (Oreochromis niloticus and O. mossambicus) in a global context

Trichodina centrostrigeata Basson, Van As et Paperna, 1983 from Oreochromis mossambicus (Peters) and O. niloticus (Linnaeus) from different host populations from Argentina, Mexico and South Africa was reviewed. Although T. centrostrigeata has a distinct denticle structure that makes morphological taxonomic inferences uncomplicated, variation of the denticles within and among individuals and populations were still observed. While traditional taxonomy of mobilines is heavily reliant on morphometrics, and recently even more so on molecular analysis, this paper proposes the use of geometric morphometry, specifically elliptical Fourier analysis, to address morphological conflicts that arise when comparing different populations. By applying this technique, combined with traditional taxonomy, it was found that T. centrostrigeata in this study can be grouped into two separate morphotypes, the first (type a) from aquaculture farms in Argentina and Mexico and the second (type b) from a natural habitat in Glen Alpine Dam, South Africa. This study supports the validity of geometric morphometry as an additional technique to distinguish not only between species but also evolutionary plasticity of the same species from different localities and habitats.Fil: Islas-Ortega, Alma Gabriela. Universidad Nacional Autónoma de México. Instituto de Biología; MéxicoFil: Marcotegui, Paula Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Basson, Linda. University of the Free State; SudáfricaFil: de Jager, Gerhard P.. University of the Free State; SudáfricaFil: Aguilar Aguilar, Rogelio. Universidad Nacional Autónoma de México. Instituto de Biología; Méxic

Does Course Specific Nudging Enhance Student Engagement, Experience and Success?: A Data-Driven Longitudinal Tale

Low levels of online student engagement impact negatively on student success and adversely affect attrition. Course learning analytics data (CLAD), combined with nudging initiatives, have emerged as strategies for engaging online students. This article presents a mixed method case study involving a staged intervention strategy focussing on the employment of timely, strategic communication interventions conducted across 19 courses and six disciplines. The research methodology utilised CLAD, online surveys, student interviews and student evaluations of teaching. The findings substantiate benefits for both academics and students. Academics benefitted from the provision of a relatively simple, accessible and proactive intervention for increasing students’ capacities to be more in control and engaged in their learning. Students benefitted as the intervention accentuated critical resources to assist them to better address assessment requirements, align their expectations more realistically with those of the course, and more readily demonstrate their learning obligations and responsibilities

Kidney Development in the Absence of Gdnf and Spry1 Requires Fgf10

GDNF signaling through the Ret receptor tyrosine kinase (RTK) is required for ureteric bud (UB) branching morphogenesis during kidney development in mice and humans. Furthermore, many other mutant genes that cause renal agenesis exert their effects via the GDNF/RET pathway. Therefore, RET signaling is believed to play a central role in renal organogenesis. Here, we re-examine the extent to which the functions of Gdnf and Ret are unique, by seeking conditions in which a kidney can develop in their absence. We find that in the absence of the negative regulator Spry1, Gdnf, and Ret are no longer required for extensive kidney development. Gdnf−/−;Spry1−/− or Ret−/−;Spry1−/− double mutants develop large kidneys with normal ureters, highly branched collecting ducts, extensive nephrogenesis, and normal histoarchitecture. However, despite extensive branching, the UB displays alterations in branch spacing, angle, and frequency. UB branching in the absence of Gdnf and Spry1 requires Fgf10 (which normally plays a minor role), as removal of even one copy of Fgf10 in Gdnf−/−;Spry1−/− mutants causes a complete failure of ureter and kidney development. In contrast to Gdnf or Ret mutations, renal agenesis caused by concomitant lack of the transcription factors ETV4 and ETV5 is not rescued by removing Spry1, consistent with their role downstream of both RET and FGFRs. This shows that, for many aspects of renal development, the balance between positive signaling by RTKs and negative regulation of this signaling by SPRY1 is more critical than the specific role of GDNF. Other signals, including FGF10, can perform many of the functions of GDNF, when SPRY1 is absent. But GDNF/RET signaling has an apparently unique function in determining normal branching pattern. In contrast to GDNF or FGF10, Etv4 and Etv5 represent a critical node in the RTK signaling network that cannot by bypassed by reducing the negative regulation of upstream signals

Refining associations between TAS2R38 diplotypes and the 6-n-propylthiouracil (PROP) taste test: findings from the Avon Longitudinal Study of Parents and Children

<p>Abstract</p> <p>Background</p> <p>Previous investigations have highlighted the importance of genetic variation in the determination of bitter tasting ability, however have left unaddressed questions as to within group variation in tasting ability or the possibility of genetic prescription of intermediate tasting ability. Our aim was to examine the relationships between bitter tasting ability and variation at the <it>TAS2R38 </it>locus and to assess the role of psychosocial factors in explaining residual, within group, variation in tasting ability.</p> <p>Results</p> <p>In a large sample of children from the Avon Longitudinal Study of Parents and Children, we confirmed an association between bitter compound tasting ability and <it>TAS2R38 </it>variation and found evidence of a genetic association with intermediate tasting ability. Antisocial behaviour, social class and depression showed no consistent relationship with the distribution of taste test scores.</p> <p>Conclusion</p> <p>Factors which could influence a child's chosen taste score, extra to taste receptor variation, appeared not to show relationships with test score. Observed spread in the distribution of the taste test scores <it>within </it>hypothesised taster groups, is likely to be, or at least in part, due to physiological differentiation regulated by other genetic contributors. Results confirm relationships between genetic variation and bitter compound tasting ability in a large sample, and suggest that <it>TAS2R38 </it>variation may also be associated with intermediate tasting ability.</p

Risk factors for Coronavirus disease 2019 (Covid-19) death in a population cohort study from the Western Cape province, South Africa

Risk factors for coronavirus disease 2019 (COVID-19) death in sub-Saharan Africa and the effects of human immunodeficiency virus (HIV) and tuberculosis on COVID-19 outcomes are unknown. We conducted a population cohort study using linked data from adults attending public-sector health facilities in the Western Cape, South Africa. We used Cox proportional hazards models, adjusted for age, sex, location, and comorbidities, to examine the associations between HIV, tuberculosis, and COVID-19 death from 1 March to 9 June 2020 among (1) public-sector “active patients” (≥1 visit in the 3 years before March 2020); (2) laboratory-diagnosed COVID-19 cases; and (3) hospitalized COVID-19 cases. We calculated the standardized mortality ratio (SMR) for COVID-19, comparing adults living with and without HIV using modeled population estimates.Among 3 460 932 patients (16% living with HIV), 22 308 were diagnosed with COVID-19, of whom 625 died. COVID19 death was associated with male sex, increasing age, diabetes, hypertension, and chronic kidney disease. HIV was associated with COVID-19 mortality (adjusted hazard ratio [aHR], 2.14; 95% confidence interval [CI], 1.70–2.70), with similar risks across strata of viral loads and immunosuppression. Current and previous diagnoses of tuberculosis were associated with COVID-19 death (aHR, 2.70 [95% CI, 1.81–4.04] and 1.51 [95% CI, 1.18–1.93], respectively). The SMR for COVID-19 death associated with HIV was 2.39 (95% CI, 1.96–2.86); population attributable fraction 8.5% (95% CI, 6.1–11.1)