Formative peer assessment in a CSCL environment

In this case study our aim was to gain more insight in the possibilities of qualitative formative peer assessment in a computer supported collaborative learning (CSCL) environment. An approach was chosen in which peer assessment was operationalised in assessment assignments and assessment tools that were embedded in the course material. The course concerned a higher education case-based virtual seminar, in which students were asked to conduct research and write a report in small multidisciplinary teams. The assessment assignments contained the discussion of assessment criteria, the assessment of a group report of a fellow group, and writing an assessment report. A list of feedback rules was one of the assessment tools. A qualitative oriented study was conducted, focussing on the attitude of students towards peer assessment and practical use of peer assessment assignments and tools. Results showed that students’ attitude towards peer assessment was positive and that assessment assignments had added value. However, not all students fulfilled all assessment assignments. Recommendations for implementation of peer assessment in CSCL environments as well as suggestions for future research are discussed

OC6 project Phase IV: Validation of numerical models for novel floating offshore wind support structures

\ua9 Copyright: This paper provides a summary of the work done within Phase IV of the Offshore Code Comparison Collaboration, Continued with Correlation and unCertainty (OC6) project, under International Energy Agency Wind Technology Collaboration Programme Task 30. This phase focused on validating the loading on and motion of a novel floating offshore wind system. Numerical models of a 3.6MW horizontal-axis wind turbine atop the TetraSpar floating support structure were compared using measurement data from a 1:43-Froude-scale test performed in the University of Maine\u27s Alfond Wind-Wave (W2) Ocean Engineering Laboratory. Participants in the project ran a series of simulations, including system equilibrium, surge offsets, free-decay tests, wind-only conditions, wave-only conditions, and a combination of wind and wave conditions. Validation of the models was performed by comparing the aerodynamic loading, floating support structure motion, tower base loading, mooring line tensions, and keel line tensions. The results show a relatively good estimation of the aerodynamic loading and a reasonable estimation of the platform motion and tower base fore-aft bending moment. However, there is a significant dispersion in the dynamic loading for the upwind mooring line. Very good agreement was observed between most of the numerical models and the experiment for the keel line tensions

A common polymorphism of the human cardiac sodium channel alpha subunit (SCN5A) gene is associated with sudden cardiac death in chronic ischemic heart disease

Cardiac death remains one of the leading causes of mortality worldwide. Recent research has shed light on pathophysiological mechanisms underlying cardiac death, and several genetic variants in novel candidate genes have been identified as risk factors. However, the vast majority of studies performed so far investigated genetic associations with specific forms of cardiac death only (sudden, arrhythmogenic, ischemic etc.). The aim of the present investigation was to find a genetic marker that can be used as a general, powerful predictor of cardiac death risk. To this end, a case-control association study was performed on a heterogeneous cohort of cardiac death victims (n=360) and age-matched controls (n=300). Five single nucleotide polymorphisms (SNPs) from five candidate genes (beta2 adrenergic receptor, nitric oxide synthase 1 adaptor protein, ryanodine receptor 2, sodium channel type V alpha subunit and transforming growth factor-beta receptor 2) that had previously been shown to associate with certain forms of cardiac death were genotyped using sequence-specific real-time PCR probes. Logistic regression analysis revealed that the CC genotype of the rs11720524 polymorphism in the SCN5A gene encoding a subunit of the cardiac voltage-gated sodium channel occurred more frequently in the highly heterogeneous cardiac death cohort compared to the control population (p=0.019, odds ratio: 1.351). A detailed subgroup analysis uncovered that this effect was due to an association of this variant with cardiac death in chronic ischemic heart disease (p=0.012, odds ratio =1.455). None of the other investigated polymorphisms showed association with cardiac death in this context. In conclusion, our results shed light on the role of this non-coding polymorphism in cardiac death in ischemic cardiomyopathy. Functional studies are needed to explore the pathophysiological background of this association. © 2015 Marcsa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

A dual function of SnRK2 kinases in the regulation of SnRK1 and plant growth

[EN] Adverse environmental conditions trigger responses in plants that promote stress tolerance and survival at the expense of growth(1). However, little is known of how stress signalling pathways interact with each other and with growth regulatory components to balance growth and stress responses. Here, we show that plant growth is largely regulated by the interplay between the evolutionarily conserved energy-sensing SNF1-related protein kinase 1 (SnRK1) protein kinase and the abscisic acid (ABA) phytohormone pathway. While SnRK2 kinases are main drivers of ABA-triggered stress responses, we uncover an unexpected growth-promoting function of these kinases in the absence of ABA as repressors of SnRK1. Sequestration of SnRK1 by SnRK2-containing complexes inhibits SnRK1 signalling, thereby allowing target of rapamycin (TOR) activity and growth under optimal conditions. On the other hand, these complexes are essential for releasing and activating SnRK1 in response to ABA, leading to the inhibition of TOR and growth under stress. This dual regulation of SnRK1 by SnRK2 kinases couples growth control with environmental factors typical for the terrestrial habitat and is likely to have been critical for the water-to-land transition of plants.We thank J.-K. Zhu for the snrk2 mutants, M. Bennett for the SnRK2.2-GFP line, C. Koncz for the SnRK1-GFP line, X. Li for the SnRK2.3-FLAG OE line, J. Schroeder for the GFP-His-FLAG and SnRK2.6-His-FLAG OE lines, C. Mackintosh for the TPS5 antibody and the Nottingham Arabidopsis stock centre for T-DNA mutant seeds. The IGC Plant Facility (Vera Nunes) is thanked for excellent plant care. This work was supported by Fundacao para a Ciencia e a Tecnologia through the R&D Units UIDB/04551/2020 (GREEN-IT-Bioresources for Sustainability) and UID/MAR/04292/2019, FCT project nos. PTDC/BIA-PLA/7143/2014, LISBOA-01-0145-FEDER-028128 and PTDC/BIA-BID/32347/2017, and FCT fellowships/contract nos. SFRH/BD/122736/2016 (M.A.), SFRH/BPD/109336/2015 (A.C.), PD/BD/150239/2019 (D.R.B.), and IF/00804/2013 (E.B.G.). Work in P.L.R.'s laboratory was funded by MCIU grant no. BIO2017-82503-R. C.M. thanks the LabEx Paris Saclay Plant Sciences-SPS (ANR-10-LABX-040-SPS) for support. B.B.P. was funded by Programa VALi+d GVA APOSTD/2017/039. This project has received funding from the European Union Horizon 2020 research and innovation programme (grant agreement no. 867426-ABA-GrowthBalance-H2020-WF-2018-2020/H2020-WF-01-2018, awarded to B.B.P.). This work is dedicated to the memory of our beloved friend and colleague Americo Rodrigues.Belda-Palazón, B.; Adamo, M.; Valerio, C.; Ferreira, LJ.; Confraria, A.; Reis-Barata, D.; Rodrigues, A.... (2020). A dual function of SnRK2 kinases in the regulation of SnRK1 and plant growth. 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Cord blood banking – bio-objects on the borderlands between community and immunity

Umbilical cord blood (UCB) has become the focus of intense efforts to collect, screen and bank haematopoietic stem cells (HSCs) in hundreds of repositories around the world. UCB banking has developed through a broad spectrum of overlapping banking practices, sectors and institutional forms. Superficially at least, these sectors have been widely distinguished in bioethical and policy literature between notions of the ‘public’ and the ‘private’, the commons and the market respectively. Our purpose in this paper is to reflect more critically on these distinctions and to articulate the complex practical and hybrid nature of cord blood as a ‘bio-object’ that straddles binary conceptions of the blood economies. The paper draws upon Roberto Esposito’s reflections on biopolitics and his attempt to transcend the dualistic polarisations of immunity and community, or the private and the public. We suggest that his thoughts on immunitary hospitality resonate with many of the actual features and realpolitik of a necessarily internationalised and globally distributed UCB ‘immunitary regime’

Orexin-A and Orexin-B During the Postnatal Development of the Rat Brain

Orexin-A and orexin-B are hypothalamic neuropeptides isolated from a small group of neurons in the hypothalamus, which project their axons to all major parts of the central nervous system. Despite the extensive information about orexin expression and function at different parts of the nervous system in adults, data about the development and maturation of the orexin system in the brain are a bit contradictory and insufficient. A previous study has found expression of orexins in the hypothalamus after postnatal day 15 only, while others report orexins detection at embryonic stages of brain formation. In the present study, we investigated the distribution of orexin-A and orexin-B neuronal cell bodies and fibers in the brain at three different postnatal stages: 1-week-, 2-week-old and adult rats. By means of immunohistochemical techniques, we demonstrated that a small subset of cells in the lateral hypothalamus, and the perifornical and periventricular areas were orexin-A and orexin-B positive not only in 2-week-old and adult rats but also in 1-week-old animals. In addition, orexin-A and orexin-B expressing neuronal varicosities were found in many other brain regions. These results suggest that orexin-A and orexin-B play an important role in the early postnatal brain development. The widespread distribution of orexinergic projections through all these stages may imply an involvement of the two neurotransmitters in a large variety of physiological and behavioral processes also including higher brain functions like learning and memory

Strong mitochondrial DNA support for a Cretaceous origin of modern avian lineages

<p>Abstract</p> <p>Background</p> <p>Determining an absolute timescale for avian evolutionary history has proven contentious. The two sources of information available, paleontological data and inference from extant molecular genetic sequences (colloquially, 'rocks' and 'clocks'), have appeared irreconcilable; the fossil record supports a Cenozoic origin for most modern lineages, whereas molecular genetic estimates suggest that these same lineages originated deep within the Cretaceous and survived the K-Pg (Cretaceous-Paleogene; formerly Cretaceous-Tertiary or K-T) mass-extinction event. These two sources of data therefore appear to support fundamentally different models of avian evolution. The paradox has been speculated to reflect deficiencies in the fossil record, unrecognized biases in the treatment of genetic data or both. Here we attempt to explore uncertainty and limit bias entering into molecular divergence time estimates through: (i) improved taxon (<it>n </it>= 135) and character (<it>n = </it>4594 bp mtDNA) sampling; (ii) inclusion of multiple cladistically tested internal fossil calibration points (<it>n </it>= 18); (iii) correction for lineage-specific rate heterogeneity using a variety of methods (<it>n </it>= 5); (iv) accommodation of uncertainty in tree topology; and (v) testing for possible effects of episodic evolution.</p> <p>Results</p> <p>The various 'relaxed clock' methods all indicate that the major (basal) lineages of modern birds originated deep within the Cretaceous, although temporal intraordinal diversification patterns differ across methods. We find that topological uncertainty had a systematic but minor influence on date estimates for the origins of major clades, and Bayesian analyses assuming fixed topologies deliver similar results to analyses with unconstrained topologies. We also find that, contrary to expectation, rates of substitution are not autocorrelated across the tree in an ancestor-descendent fashion. Finally, we find no signature of episodic molecular evolution related to either speciation events or the K-Pg boundary that could systematically mislead inferences from genetic data.</p> <p>Conclusion</p> <p>The 'rock-clock' gap has been interpreted by some to be a result of the vagaries of molecular genetic divergence time estimates. However, despite measures to explore different forms of uncertainty in several key parameters, we fail to reconcile molecular genetic divergence time estimates with dates taken from the fossil record; instead, we find strong support for an ancient origin of modern bird lineages, with many extant orders and families arising in the mid-Cretaceous, consistent with previous molecular estimates. Although there is ample room for improvement on both sides of the 'rock-clock' divide (e.g. accounting for 'ghost' lineages in the fossil record and developing more realistic models of rate evolution for molecular genetic sequences), the consistent and conspicuous disagreement between these two sources of data more likely reflects a genuine difference between estimated ages of (i) stem-group origins and (ii) crown-group morphological diversifications, respectively. Further progress on this problem will benefit from greater communication between paleontologists and molecular phylogeneticists in accounting for error in avian lineage age estimates.</p