cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Atomically Resolved Chemical Reactivity of Small Fe Clusters
Creators: name: Berwanger, Julian
name: Polesya, Svitlana
name: Mankovsky, Sergiy
name: Ebert, Hubert
name: Giessibl, Franz J.
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: 530 Physik

description: Small metal clusters have been investigated for decades due to their beneficial catalytic activity. It was found that edges are most reactive and the number of catalytic events increases with the cluster’s size. However, a direct measurement of chemical reactivity of individual atoms within the clusters has not been reported yet. We combine the high-resolution capability of CO-terminated tips in scanning probe microscopy with their ability to probe chemical binding forces on single Fe atoms to study the chemical reactivity of atom-by-atom assembled Fe clusters from 1 to 15 atoms on the atomic scale. We find that the chemical reactivity of individual atoms within flat Fe clusters does not depend on the cluster size but on the coordination number of the investigated atom. Furthermore, we explain the atomic contrast of the investigated Fe clusters by relating the force spectra of individual atoms with atomic force microscopy images of the clusters.
Ready for change: seed traits contribute to the high adaptability of mudflat species to their unpredictable habitat
Creators: name: Phartyal, Shyam S.
name: Rosbakh, Sergey
name: Ritz, C.
name: Poschlod, Peter
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: mudflats, phylogenetic PCA, regeneration niche, regeneration traits, seed dispersal traits,seed ecology, seed germination and establishment traits, seed persistent traits, wetland
subject: 580 Pflanzen (Botanik)

description: Question A better understanding of species distribution and establishment requires in‐depth information on their seed ecology. We hypothesised that seed traits of mudflat species may indicate a strong environmental adaptation in their highly specialised habitat. Furthermore, we asked the question, do seeds of mudflat species have a specific trait value to contribute high adaptability to small‐scale variation in their unpredictable habitat? Location Central Europe. Methods Seeds of 30 typical mudflat species were used to measure 15 traits that govern seed dispersal (buoyancy and production), persistence (seed desiccation, mass and persistence in soil), and germination and establishment (germination response to different light, temperature and oxygen conditions). Cluster analysis and phylogenetic principal components analysis (pPCA) were conducted to define potential mudflat species functional groups as per their ecological optima. Results Seed production and seed mass displayed extremely high variation while seed buoyancy, desiccation and persistence in soil showed almost no variation. All study species produced buoyant, desiccation‐tolerant and long‐term persistent seeds. Germination and establishment traits also displayed similarity in their responses to different germination treatments as the majority (73%) of species has a moderate seed germination niche width. They germinated well under light/aerobic conditions irrespective to temperature fluctuations. The cluster analysis and pPCA separated species into three potential plant functional groups as ‘true’, ‘flood‐resistant’ and ‘facultative’, mudflat species. Conclusion Moderate variation in the seed traits of mudflat plants suggests they employ different ecological strategies that seem highly predictive to the peculiarity of their specific micro‐habitats, which are largely controlled by the hydroperiod gradient. It implies that seed trait information, which further needs to be tested for their adaptability, can advance our understanding of how community composition at the micro‐habitat level depends on trait values of participating species.
Synthesis and rheology of poly(lactide)s and their lignin composites
Creators: name: Chile, Love-Ese
Publisher: name: University of British Columbia
Year: 2017

description: Synthetic plastics were first introduced 180 years ago, but the materials we have produced are likely to persist on our earth for thousands of years. Global shifts in thinking have urged researchers to focus their attention on bio-derived and biodegradable polymers. One such polymer is poly(lactic acid) (PLA). Despite its environmental benefits, PLA has several material weaknesses which hinder it’s use as a replacement for commodity plastics. Highly active and selective indium catalysts for the ring-opening polymerization of lactide isomers have recently been developed by the Mehrkhodavandi group. By utilizing these catalysts, modification of tacticity and end-group functionality of PLAs are possible, permitting exploration into the effect of these modifications on chain interactions in PLA. The thermal and rheological behaviours of PLAs with different microstructures were compared. The molecular weight between entanglements was greatest for the syndiotactically enriched PLAs, giving rise to the lowest zero-shear viscosity. In addition, hetero- and isotactically enriched PLA had higher flow activation energies than syndiotactic variants, implying the inclusion of transient aggregate regions within these polymers due to enhanced L- and D-interactions. A series of aryl-capped PLAs were synthesized by living ring-opening polymerization with a chain transfer agent using a previously reported dinuclear indium catalyst, [(NNO)InCl]₂(μ-Cl)(μ-OEt) (A). Thermal, rheological and mechanical techniques were employed to understand the extent and strength of association caused by arylated chain ends. It is shown that the end-group has a greater effect on the properties of low molecular weight PLAs due to the larger number density of aryl end groups; significant interactions can be induced under oscillatory shear conditions in the low frequency flow regime (terminal zone). The lignocellulosic biorefinery industry has been expanding in recent years and now provides researchers access to a range of bio-based composite materials through blending and copolymerization. Lignin-graft-PLA copolymers were synthesized via different routes and the PLA products were analyzed. Polymers were found to have cyclic structures at low lignin loading and star-like structures at higher lignin loading. Rheological studies were undertaken to derive useful structure-property relationships and optimize material properties.
Health sciences libraries in Germany: new directions
Creators: name: Knüttel, Helge
name: Krause, Evamaria
name: Semmler-Schmetz, Martina
name: Reimann, Iris
name: Metzendorf, Maria-Inti
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Germany; Access to information; Libraries, health care; Library services; Librarianship, health science
subject: 020 Bibliotheks- und Informationswissenschaft

description: This feature is part of a series about medical library services in various countries. It gives an overview of the state of and selected current developments of medical library services to support research, education and clinical practice in Germany. Findings from an online survey and issues of access to health information are discussed in relation to the German health care system.J.M.
Asymmetric transmission in planar chiral split-ring metamaterials: Microscopic Lorentz-theory approach
Creators: name: Novitsky, Andrey V.
name: Galynsky, Vladimir M.
name: Zhukovsky, Sergei V.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The electronic Lorentz theory is employed to determine the electromagnetic response of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the effective permittivity tensor of the metamaterial is calculated. Whenever the split ring lacks in-plane mirror symmetry, the corresponding permittivity tensor has a crystallographic structure of an elliptically dichroic medium, and the metamaterial exhibits optical properties of planar chiral structures. Its transmission spectra are different for right-handed vs. left-handed circular polarization of the incident wave, so the structure changes its transmittance when the direction of incidence is reversed. The magnitude of this change is shown to be related to the geometric parameters of the split ring. The proposed approach can be straightforwardly generalized to a wide variety of metal-dielectric metamaterial geometries.
description: 12 pages, 8 figures
An Innovative Blended Learning Model for Information Technology Courses for a South African University
Creators: name: Jere, Nobert
name: Mavuso, Nosipho
Publisher: name: Walter Sisulu University
Year: 2023
Subjects: Other information and computing sciences not elsewhere classified

description: Abstract: The learning paradigm is currently experiencing a drastic shift from the traditional teaching and learning practices that have dominated the education sector previously. Many institutions of higher learning have fully adopted a blended learning approach in the facilitation of knowledge sharing. It remains very problematic to accommodate learners’ needs especially for Information Technology Courses. The inquisitiveness of the current generation of learners brings about a mandate for educators and institutions to implement new innovative teaching and learning practices. This exploratory study uses a quantitative approach, where online questionnaires were distributed to Information Technology students at one South African University. Results show that learners prefer blended methods of teaching. More so, learners prefer to be taught using diverse and innovative teaching approaches. We propose an innovative blended model to assist in teaching Information Technology courses, while engaging and motivating students.

 Keywords: Teaching & Learning, Blended Learning, Learning Management System, Innovative Technologies, Blended Model.
Mixed finite elements for numerical weather prediction
Creators: name: Cotter, C. J.
name: Shipton, J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We show how two-dimensional mixed finite element methods that satisfy the conditions of finite element exterior calculus can be used for the horizontal discretisation of dynamical cores for numerical weather prediction on pseudo-uniform grids. This family of mixed finite element methods can be thought of in the numerical weather prediction context as a generalisation of the popular polygonal C-grid finite difference methods. There are a few major advantages: the mixed finite element methods do not require an orthogonal grid, and they allow a degree of flexibility that can be exploited to ensure an appropriate ratio between the velocity and pressure degrees of freedom so as to avoid spurious mode branches in the numerical dispersion relation. These methods preserve several properties of the C-grid method when applied to linear barotropic wave propagation, namely: a) energy conservation, b) mass conservation, c) no spurious pressure modes, and d) steady geostrophic modes on the $f$-plane. We explain how these properties are preserved, and describe two examples that can be used on pseudo-uniform grids: the recently-developed modified RT0-Q0 element pair on quadrilaterals and the BDFM1-\pdg element pair on triangles. All of these mixed finite element methods have an exact 2:1 ratio of velocity degrees of freedom to pressure degrees of freedom. Finally we illustrate the properties with some numerical examples.
description: Revision after referee comments
Predicting User Behavior in Smart Spaces with LLM-Enhanced Logs and Personalized Prompts
Creators: name: Song, Yunpeng
name: Li, Jiawei
name: Bian, Yiheng
name: Cai, Zhongmin
Publisher: name: arXiv
Year: 2024
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: Enhancing the intelligence of smart systems, such as smart home, and smart vehicle, and smart grids, critically depends on developing sophisticated planning capabilities that can anticipate the next desired function based on historical interactions. While existing methods view user behaviors as sequential data and apply models like RNNs and Transformers to predict future actions, they often fail to incorporate domain knowledge and capture personalized user preferences. In this paper, we propose a novel approach that incorporates LLM-enhanced logs and personalized prompts. Our approach first constructs a graph that captures individual behavior preferences derived from their interaction histories. This graph effectively transforms into a soft continuous prompt that precedes the sequence of user behaviors. Then our approach leverages the vast general knowledge and robust reasoning capabilities of a pretrained LLM to enrich the oversimplified and incomplete log records. By enhancing these logs semantically, our approach better understands the user's actions and intentions, especially for those rare events in the dataset. We evaluate the method across four real-world datasets from both smart vehicle and smart home settings. The findings validate the effectiveness of our LLM-enhanced description and personalized prompt, shedding light on potential ways to advance the intelligence of smart space.
A Runge approximation theorem for pseudo-holomorphic maps
Creators: name: Gournay, Antoine
Publisher: name: arXiv
Year: 2010
Subjects: subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: The Runge approximation theorem for holomorphic maps (U -> C) is a fundamental result in complex analysis. The aim of this article is to prove such a result for (pseudo-)holomorphic maps from a compact Riemann surface to a compact (almost-)complex manifold M under certain assumptions. Though the setting is definitively that of pseudo-holomorphic maps it also covers some complex varieties.
description: 36 pages
Machine learning algorithms to infer trait-matching and predict species interactions in ecological networks
Creators: name: Pichler, Maximilian
name: Boreux, V.
name: Klein, A.-M.
name: Hartig, Florian
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: bipartite networks, causal inference, deep learning, hummingbirds, insect pollinators, machine learning, pollination syndromes, predictive modelling
subject: 580 Pflanzen (Botanik)

description: Ecologists have long suspected that species are more likely to interact if their traits match in a particular way. For example, a pollination interaction may be more likely if the proportions of a bee's tongue fit a plant's flower shape. Empirical estimates of the importance of trait‐matching for determining species interactions, however, vary significantly among different types of ecological networks. Here, we show that ambiguity among empirical trait‐matching studies may have arisen at least in parts from using overly simple statistical models. Using simulated and real data, we contrast conventional generalized linear models (GLM) with more flexible Machine Learning (ML) models (Random Forest, Boosted Regression Trees, Deep Neural Networks, Convolutional Neural Networks, Support Vector Machines, naïve Bayes, and k‐Nearest‐Neighbor), testing their ability to predict species interactions based on traits, and infer trait combinations causally responsible for species interactions. We found that the best ML models can successfully predict species interactions in plant–pollinator networks, outperforming GLMs by a substantial margin. Our results also demonstrate that ML models can better identify the causally responsible trait‐matching combinations than GLMs. In two case studies, the best ML models successfully predicted species interactions in a global plant–pollinator database and inferred ecologically plausible trait‐matching rules for a plant–hummingbird network from Costa Rica, without any prior assumptions about the system. We conclude that flexible ML models offer many advantages over traditional regression models for understanding interaction networks. We anticipate that these results extrapolate to other ecological network types. More generally, our results highlight the potential of machine learning and artificial intelligence for inference in ecology, beyond standard tasks such as image or pattern recognition.
Diamagnetic susceptibility obtained from the six-vertex model and its implications for the high-temperature diamagnetic state of cuprate superconductors
Creators: name: Sau, Jay D.
name: Tewari, Sumanta
Publisher: name: arXiv
Year: 2010
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We study the diamagnetism of the 6-vertex model with the arrows as directed bond currents. To our knowledge, this is the first study of the diamagnetism of this model. A special version of this model, called F model, describes the thermal disordering transition of an orbital antiferromagnet, known as d-density wave (DDW), a proposed state for the pseudogap phase of the high-Tc cuprates. We find that the F model is strongly diamagnetic and the susceptibility may diverge in the high temperature critical phase with power law arrow correlations. These results may explain the surprising recent observation of a diverging low-field diamagnetic susceptibility seen in some optimally doped cuprates within the DDW model of the pseudogap phase.
description: 4.5 pages, 2 figures, revised version accepted in Phys. Rev. Lett
Smart City eReadiness Assessment – Is City of Windhoek Ready?
Creators: name: Erastus, Licky Richard
name: Jere, Nobert Rangarirai
name: Shava, Fungai Bhunu
Publisher: name: Walter Sisulu University
Year: 2023
Subjects: Other information and computing sciences not elsewhere classified

description: Abstract: African Smart Cities are challenged by main issues ranging from sustainable services, efficient services, lack of supporting policies and security issues. Most of those commonly visited cities such as Cape Town (South Africa), Windhoek (Namibia) are making efforts to improve service delivery. However, as the number of visitors and citizens increase, it makes it difficult for city fathers to plan and manage the pressure. Some African countries have done well in learning from advanced countries and benchmark with those cities e.g Barcelona, Malta. However, the one size fits all approach does not seem to work for many cities, due to cultural and societal differences. With the growing population and the need for better services, African Cities have to prepare. The City of Windhoek in Namibia is selected. Participants are engaged using interviews and online questionnaire. Current smart city assessment models were considered. The paper explains what the current stakeholders in Windhoek understand about smart cities. We considered their understanding and applied one assessment model to check the readiness. Results show that participants are aware of the components and what is needed for a smart city. Based on current ICT infrastructure challenges, it was not clear to clearly rate the City of Windhoek’s readiness. Determining the level or stage where the city is currently at is not easy. The paper presents the current state of City of Windhoek and how one assessment model has been applied to determine the readiness.
 Keywords: Smart City, ereadiness, Smart Governance, Innovative technologies, smart technologies, sustainable ICTs, Smart City Maturity Model
Percutaneous Cannulation for Extracorporeal Life Support in Severely and Morbidly Obese Patients
Creators: name: Keyser, Andreas
name: Philipp, Alois
name: Zeman, Florian
name: Lubnow, Matthias
name: Lunz, Dirk
name: Zimmermann, Markus
name: Schmid, Christof
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: extracorporeal life support, extracorporeal membrane oxygenation, percutaneous cannulation, obesity
subject: 610 Medizin

description: Background: Extracorporeal life support systems are well-established devices for treating patients with acute cardiopulmonary failure. Severe or morbid obesity may result in complications such as limb ischemia, bleeding, unsuccessful cannulation, or infection at the cannulation sites. This article reports on our experience with cannulation and associated complications in severely and morbidly obese patients. Methods: Between January 2006 and September 2016, 153 severely or morbidly obese patients with a body mass index >35 kg/m2 were cannulated percutaneously for extracorporeal life support at our center. Among those, 115 patients were treated with venovenous extracorporeal membrane oxygenation (VV ECMO) for acute lung failure and 38 patients with venoarterial extracorporeal membrane oxygenation (VA ECMO) for cardiogenic shock. Complications related to percutaneous access and long-term follow-up were analyzed retrospectively. Primary focus was on the success of cannulation, outcome, thrombosis, bleeding, limb ischemia, and infection at the cannulation site. Normal-weight patients receiving extracorporeal life support served as control. Results: Percutaneous cannulation was successfully performed in all patients. Eighty-five (74%) patients were weaned from VV ECMO and 20 (52%) patients were weaned from VA ECMO. Limb ischemia requiring surgical intervention occurred in 5 (3%) patients, bleeding in 7 (5%) patients, and wound infection in 3 (2%) patients. In all other patients, decannulation was uneventful. These data as well as the long-term survival rates were comparable to those of normal-weight patients (P > .05). Conclusion: Percutaneous vessel cannulation for extracorporeal life support systems is generally feasible. Therefore, percutaneous cannulation may well be performed in severely and morbidly obese patients. Patient outcome rather depends on appropriate support than on anatomy.
description: Open Access-Komponente aus einer Allianzlizenz
Identification of a Novel Subset of Human Airway Epithelial Basal Stem Cells
Creators: name: Zhong, Yong-Ping
name: Cheng, Christopher
name: Moredock, Maria
name: Flory, Mark R.
name: Randell, Scott H.
name: Chang, Matthew E. K.
name: Higgins, Claire T.
name: Katoch, Parul
name: Streeter, Philip R.
Publisher: name: MDPI
Year: 2024

description: The basal cell maintains the airway’s respiratory epithelium as the putative resident stem cell. Basal cells are known to self-renew and differentiate into airway ciliated and secretory cells. However, it is not clear if every basal cell functions as a stem cell. To address functional heterogeneity amongst the basal cell population, we developed a novel monoclonal antibody, HLO1-6H5, that identifies a subset of KRT5+ (cytokeratin 5) basal cells. We used HLO1-6H5 and other known basal cell-reactive reagents to isolate viable airway subsets from primary human airway epithelium by Fluorescence Activated Cell Sorting. Isolated primary cell subsets were assessed for the stem cell capabilities of self-renewal and differentiation in the bronchosphere assay, which revealed that bipotent stem cells were, at minimum 3-fold enriched in the HLO1-6H5+ cell subset. Crosslinking-mass spectrometry identified the HLO1-6H5 target as a glycosylated TFRC/CD71 (transferrin receptor) proteoform. The HLO1-6H5 antibody provides a valuable new tool for identifying and isolating a subset of primary human airway basal cells that are substantially enriched for bipotent stem/progenitor cells and reveals TFRC as a defining surface marker for this novel cell subset.
Exploring an Appropriate Continuing Professional Teacher Development (Cptd) Model for Rural Teachers: A Case of Chris Hani West Rural Schools, Eastern Cape
Creators: name: Mashologu, Mabel-Wendy N.
name: Chiphambo, Shakespear Maliketi
Publisher: name: Walter Sisulu University
Year: 2023
Subjects: Teacher and student wellbeing
Teacher education and professional development of educators

description: Abstract Drawing from the research that assessed the implementation of Continuing Professional Teacher Development (CPTD) in Lady Frere, this study explored a most appropriate CPTD model that could be used in Chris Hani West (then Lady Frere circuit) for developing rural teachers. A professional teacher development model needs to be a powerful tool to support better classroom practice and learner performance. Studies indicate that teachers, as adults, need to choose their learning opportunities according to their interest and considering their own classroom practice and needs. Furthermore, a well-designed collaborated attempt is one of the important features of a well-planned teacher development programme. Nevertheless, it appeared from existing research that little had been researched on getting a most appropriate rural teacher development model that would result in teacher change and better learner performance. In this paper, we explored the implementation of professional teacher development of rural teachers in Chris Hani West Education district. A mixed-method design was adopted where a sample of fifteen Grade 11 teachers from fifteen out of eighteen secondary schools was purposely selected (one from each school). To collect data, concurrent procedures were used where face-to-face self-administered questionnaires were given to each Grade Eleven teacher and Heads of Departments, with permission verbally granted by the principals of schools in the sample. Interviews were conducted with five randomly selected teachers and Heads of Departments in the circuit. Quantitative data were analysed through frequencies and percentages while tape-recorded qualitative data were summarised into themes and concepts and linked into similar categories. The aim of this paper was to explore a most appropriate model that would lead to powerful professional learning and improved learner performance. The authors, therefore, studied interview responses from the participants and tables indicating the responses from questionnaires. The responses from both instruments assisted the authors to determine the most appropriate model for teacher development programmes. The findings of the exploration indicated that teachers do not approve of the models of professional development offered by education officials. The few responses from both research instruments used in the study attest that teachers were not pleased with the development models to which they were exposed. Having consolidated the findings, it is recommended that the best development model to be used for rural teachers should be communities of practice. Keywords: Continuing Professional Teacher Development, rural district, communities of practice
Tracking infection diffusion in social networks
Creators: name: Pedersen, Tavis Joseph
Publisher: name: University of British Columbia
Year: 2017

description: This thesis explores the problem of tracking the diffusion of contagion processes on social networks. Infection (or Information) diffusion is modeled using the Susceptible-Infected-Susceptible (SIS) model. Mean field approximation is employed to approximate the discrete valued infection dynamics by a deterministic ordinary differential equation, thereby yielding a generative model for the infection diffusion. The infection is shown to follow polynomial dynamics and is estimated using an exact non-linear Bayesian filter. We compute posterior Cramer-Rao bounds to obtain the fundamental limits of the filter which depend on the structure of the network. The SIS model is extended to include homophily, and filtering on these networks using the exact non-linear Bayesian filter is illustrated. With consideration for the collaborative or antagonistic nature of some social processes on networks, we present an alternative, game theoretic, model for the spread of information based on the evolutionary Moran process. The diffusion of collaboration following this Moran model is estimated using a particle filter. Additionally, we validate the efficacy of our method with diffusion data from a real-world online social media platform, Twitter. We find that SIS model is a good fit for the information diffusion and the non-linear filter effectively tracks the information diffusion.
On generalized Sethi-Vafa-Witten formulas
Creators: name: Fullwood, James
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 14C17

description: We present a formula for computing proper pushforwards of classes in the Chow ring of a projective bundle under the projection $π:\Pbb(\Escr)\rightarrow B$, for $B$ a non-singular compact complex algebraic variety of any dimension. Our formula readily produces generalizations of formulas derived by Sethi,Vafa, and Witten to compute the Euler characteristic of elliptically fibered Calabi-Yau fourfolds used for F-theory compactifications of string vacua. The utility of such a formula is illustrated through applications, such as the ability to compute the Chern numbers of any non-singular complete intersection in such a projective bundle in terms of the Chern class of a line bundle on $B$.
Long-term outcome of common femoral artery endarterectomy in octogenarians and non-octogenarians
Creators: name: Uhl, C.
name: Götzke, H.
name: Zeman, Florian
Publisher: name: Universität Regensburg
Year: 2020
Subjects: subject: Common femoral artery endarterectomy, octogenarians, non-octogenarians, peripheral arterial occlusion disease, critical limb ischemia, claudication
subject: 610 Medizin

description: Objective: Arteriosclerotic disease of the common femoral artery can be treated by surgical or endovascular intervention. Elderly patients are said to have a worse outcome if treated by surgical means; however, data to support this theory are missing. Methods: Retrospective analysis of all patients who underwent common femoral artery endarterectomy between March 2007 and July 2018 in our clinic. Group 1 included all patients <80 years and Group 2 included all patients ⩾80 years. Endpoints were patency rates, limb salvage, and overall survival. Results: During this time period, 977 common femoral artery endarterectomies were performed. Indication was claudication in 61.5% and critical limb ischemia in 38.5%. Group 1 included 805 cases (82.4%) and Group 2 included 172 cases (17.6%). Thirty-day mortality was 2.7% (Group 1 = 1.6% versus Group 2 = 7.6%; p
description: Open Access-Komponente aus einer Allianzlizenz
Assessing Micro and Macro-Teaching Strategies in Science Teaching: A South African Perspective
Creators: name: Mtsi, Nomxolisi
name: Chiphambo, Shakespear Maliketi
name: Mashologu, Mabel-Wendy N.
Publisher: name: Walter Sisulu University
Year: 2023
Subjects: Applications in physical sciences
Applications in life sciences

description: Abstract Literature highlights that science instructional strategies must be diverse to encourage an active learning approach that enhances both mental thinking and physical skills in learners. The purpose of the study was to investigate the instructional strategies that Natural Science teachers use to promote science learning. The descriptive survey design was employed in the study. The study was informed by social constructivism. Thirty out of sixty-seven schools were selected using simple random sampling. Cronbach’s alpha test was used to ascertain the scale reliability of the questionnaire. The findings revealed that teachers mostly use the following strategies: Investigation 97% (n=29); Discussion, Presentation and Project 93% (n=28); Problem solving 90% (n=27); Demonstration and Question and Answer 87% (n=26); Case study and Brainstorming 77% (n=23); Role-play 63% (19) and Lecture 57% (17). While the least used strategies are modelling 47% (n=14), Inquiry 27% (n=8), and Simulation 23% (n=7). The study, therefore, recommends that Natural Sciences teachers should make use of different teaching strategies in their lessons to enhance interactive learning that will encourage critical thinking.
 Keywords: Natural Sciences, instructional, strategies, teachers
A dynamical approach to von Neumann dimension
Creators: name: Gournay, Antoine
Publisher: name: arXiv
Year: 2010
Subjects: subject: Functional Analysis (math.FA)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: Let G be an amenable group and V be a finite dimensional vector space. Gromov pointed out that the von Neumann dimension of linear subspaces of l^2(G;V) (with respect to G) can be obtained by looking at a growth factor for a dynamical (pseudo-)distance. This dynamical point of view (reminiscent of metric entropy) does not requires a Hilbertian structure. It is used in this article to associate to a $Γ$-invariant linear subspaces Y of l^p(G;V) a real positive number dim_{l^p} Y (which is the von Neumann dimension when p=2). By analogy with von Neumann dimension, the properties of this quantity are explored to conclude that there can be no injective G-equivariant linear map of finite-type from l^p(G;V) -> l^p(G; V') if dim V > dim V'. A generalization of the Ornstein-Weiss lemma is developed along the way.
description: 23 pages. Mistake corrected in statement of P2
Critical Magnetic Number in the MHD Rayleigh-Taylor instability
Creators: name: Wang, Yanjin
Publisher: name: arXiv
Year: 2010
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 76E25, 76E17, 76W05, 35Q35

description: We reformulate in Lagrangian coordinates the two-phase free boundary problem for the equations of Magnetohydrodynamics in a infinite slab, which is incompressible, viscous and of zero resistivity, as one for the Navier-Stokes equations with a force term induced by the fluid flow map. We study the stabilized effect of the magnetic field for the linearized equations around the steady-state solution by assuming that the upper fluid is heavier than the lower fluid, $i. e.$, the linear Rayleigh-Taylor instability. We identity the critical magnetic number $|B|_c$ by a variational problem. For the cases $(i)$ the magnetic number $\bar{B}$ is vertical in 2D or 3D; $(ii)$ $\bar{B}$ is horizontal in 2D, we prove that the linear system is stable when $|\bar{B}|\ge |B|_c$ and is unstable when $|\bar{B}|
description: 25 pages;v2: typos
Essays in applied microeconomics
Creators: name: Molnár, Tímea Laura
Publisher: name: University of British Columbia
Year: 2017

description: The first chapter studies parents’ intra-household time and resource allocation, focusing on parental quality time, and the implications for early childhood development. I develop a model that explains the "parental time-education gradient" puzzle, and I confirm its predictions, exploiting exogenous, drastic daycare price decrease in Quebec. I find that as daycare becomes cheaper, parents increase time devoted to their children, at the expense of home production and leisure, while consuming more of home production market goods (eating out, domestic help), and child market goods (daycare, games and toys); the time reallocation is larger for higher-educated parents. The estimated structural parameters uncover the pivotal role of complementarity (substitutability) between time and market goods in child human capital (home) production, and suggest a time efficiency advantage in non-market activities for higher-educated parents. I use them to assess how universal daycare shapes skill gaps in early childhood. My findings point to differential parental investment and time efficiency as important mechanisms behind widening skill gaps in early childhood. The second chapter measures the causal impact of academic redshirting---the practice of postponing school entry of an age-eligible child---on student achievement and mental health. I use Hungarian administrative testscore data for 2008-2014, and an instrumental variable framework. The institutional feature I exploit is a school-readiness evaluation, compulsory for potentially redshirted children born before January 1st. I compare children born around this cutoff and find that (1) although there are large student achievement gains for all, disadvantaged boys benefit the most from redshirting---and only they benefit in terms of mental health; (2) the positive effects of higher school-starting age are driven by absolute, rather than within-class relative age advantage. The third chapter studies how closely private insurers’ payment schedules follow Medicare's, exploiting institutional changes in Medicare's payments and dramatic bunching in markups over Medicare rates. We find that, although Medicare's rates are influential, 25 percent of physician services, representing 45 percent of spending, deviate from this benchmark. Heterogeneity in the pervasiveness and direction of deviations reveals that the private market coordinates around Medicare's pricing for simplicity but innovates when sufficient value is at stake.
Thin and fat sets for doubling measures in metric spaces
Creators: name: Ojala, Tuomo
name: Rajala, Tapio
name: Suomala, Ville
Publisher: name: arXiv
Year: 2011
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 28A12 (Primary), 30L10 (Secondary)

description: We consider sets in uniformly perfect metric spaces which are null for every doubling measure of the space or which have positive measure for all doubling measures. These sets are called thin and fat, respectively. In our main results, we give sufficient conditions for certain cut-out sets being thin or fat.
Effect of Physical Manipulatives on Learners’ Understanding of Surface Area and Volume Of Prisms
Creators: name: Chiphambo, Shakespear Maliketi
name: Mashologu, Mabel-Wendy N.
name: Mtsi, Nomxolisi
Publisher: name: Walter Sisulu University
Year: 2023
Subjects: Curriculum and pedagogy not elsewhere classified
Mathematics and numeracy curriculum and pedagogy
Physical education and development curriculum and pedagogy

description: SAICEd 2020 Proceedings
 Abstract Research highlights that learners have difficulties in comprehending the difference between surface area and volume of prisms. The study sought to explore the effect of physical manipulatives on learners’ understanding of surface area and volume of prisms. The concurrent design exploratory case study which employed both quantitative and qualitative research methods provides a comprehensive analysis of the research problem. Simple random sampling was used to select eighteen learners to participate in the study. The diagnostic test was administered to explore learners’ difficulties and the post-test was then administered to evaluate the intervention which made use of physical manipulatives in trying to address the identified problems. GeoGebra Classic 5 software was utilised to conduct the paired t-test differences of the data. Semi-structured interview responses were transcribed and reported in themes and descriptive script. This study revealed that there is a significant effect on the use of physical manipulatives to teach surface area and volume of prisms. Therefore, the study recommends that mathematics teachers integrate physical manipulatives when teaching to enhance learners’ understanding of surface area and volume of prisms. Keywords: physical manipulatives, teaching and learning, surface area of prism, volume of prism
Universal Lefschetz fibrations over bounded surfaces
Creators: name: Zuddas, Daniele
Publisher: name: arXiv
Year: 2011
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 55R55 (Primary) 57N13 (Secondary)

description: In analogy with the vector bundle theory we define universal and strongly universal Lefschetz fibrations over bounded surfaces. After giving a characterization of these fibrations we construct very special strongly universal Lefschetz fibrations when the fiber is the torus or an orientable surface with connected boundary and the base surface is the disk. As a by-product we also get some immersion results for 4-dimensional 2-handlebodies.
description: Last update: minor revisions; Major revision: more general definitions and results; 15 pages, 16 figures
Almost commutative Riemannian geometry: wave operators
Creators: name: Majid, Shahn
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Algebra (math.QA)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 81R50, 58B32, 83C57

description: Associated to any (pseudo)-Riemannian manifold $M$ of dimension $n$ is an $n+1$-dimensional noncommutative differential structure $(Ω^1,\extd)$ on the manifold, with the extra dimension encoding the classical Laplacian as a noncommutative `vector field'. We use the classical connection, Ricci tensor and Hodge Laplacian to construct $(Ω^2,\extd)$ and a natural noncommutative torsion free connection $(\nabla,σ)$ on $Ω^1$. We show that its generalised braiding $σ:Ω^1\tensΩ^1\to Ω^1\tensΩ^1$ obeys the quantum Yang-Baxter or braid relations only when the original $M$ is flat, i.e their failure is governed by the Riemann curvature, and that $σ^2=\id$ only when $M$ is Einstein. We show that if $M$ has a conformal Killing vector field $τ$ then the cross product algebra $C(M)\rtimes_τ\R$ viewed as a noncommutative analogue of $M\times\R$ has a natural $n+2$-dimensional calculus extending $Ω^1$ and a natural spacetime Laplacian now directly defined by the extra dimension. The case $M=\R^3$ recovers the Majid-Ruegg bicrossproduct flat spacetime model and the wave-operator used in its variable speed of light preduction, but now as an example of a general construction. As an application we construct the wave operator on a noncommutative Schwarzschild black hole and take a first look at its features. It appears that the infinite classical redshift/time dilation factor at the event horizon is made finite.
description: 39 pages, 4 pdf images. Removed previous Sections 5.1-5.2 to a separate paper (now ArXived) to meet referee length requirements. Corresponding slight restructure but no change to remaining content
Online Mentoring for Talented Girls in STEM: The Role of Relationship Quality and Changes in Learning Environments in Explaining Mentoring Success
Creators: name: Stöger, Heidrun
name: Debatin, Tobias
name: Heilemann, Michael
name: Ziegler, Albert
Publisher: name: Universität Regensburg
Year: 2019
Subjects: subject: 370 Erziehung, Schul- und Bildungswesen

description: Although participation rates of women in science, technology, engineering, and mathematics (STEM) are continually improving, low rates are still an issue in many countries. While previous studies found positive effects of online mentoring for increasing girls’ interests in STEM, research concerning explanatory mechanisms is lacking. We found evidence that in a 1‐year online mentoring program for girls (age: M = 13.82 years, N = 998) in STEM, suitably implemented mentoring (operationalized via relationship quality in a program that systematically incorporates structural and organizational aspects of successful mentoring) was associated with positive changes in the learning environments of the mentees (as indicated by their increasing educational capital). These positive changes were associated with increases in the program‐related mentoring outcomes STEM activities and elective intentions in STEM. Finally, we found that suitably implemented online mentoring was indirectly related to an increase in these two mentoring outcomes via an increase in educational capital. These results indicate the importance of paying close attention to learning environments when planning interventions.
Exploring lecturers' emotional challenges on their work performance at a rural university in Eastern Cape Province
Creators: name: Marongwe, Newlin
name: Chiphambo, Shakespear Maliketi
name: Kasumba, Harry
Publisher: name: Walter Sisulu University
Year: 2023
Subjects: Workplace wellbeing and quality of working life

description: African Journal of Gender, Society and Development ISSN: 2634-3614 E-ISSN: 2634-3622 Formerly Journal of Gender, Information and Development in Africa (JGIDA) ISSN: 2050-4276 E-ISSN: 2050-4284 Indexed by IBSS, EBSCO, COPERNICUS, ProQuest, SABINET and J-Gate. Volume 9 Number 4, December 2020 Pp 13-31
 Abstract
 Lecturers‟ well-being is essential for successful education at any university. The paper seeks to explore the untold stories of emotional challenges faced by some lecturers in a rural institution of higher learning in Eastern Cape Province of South Africa. Today‟s universities are faced with myriad challenges, among them is lecturers‟ well-being. Lecturers‟ anxiety is now rampant but not enough attention is given to it since people assume that academics can cope with life‟s stresses. Exploring the problem and consequences on lecturers‟ work will provide strategies that could be implemented by the university management. The existential anxiety theory, qualitative-case study design and a purposeful sampling technique were used for the study. Interviews were utilised to collect data. Data presentation and analysis were done using verbatim quotations. The study established that university lecturers were overwhelmed by challenges such as job uncertainty, pressure to engage in research, supervision, frequent student unrest, dwindling resources, pressure to integrate information communication and technology in teaching and learning, and so forth. The study concluded that lecturers were facing a myriad of challenges that had a negative impact on the execution of their duties. The paper recommends that the university management should develop a model to address the lecturers‟ identified challenges.
Taming nonlocality in theories with Planck-scale-deformed Lorentz symmetry
Creators: name: Amelino-Camelia, Giovanni
name: Matassa, Marco
name: Mercati, Flavio
name: Rosati, Giacomo
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We report a general analysis of worldlines for theories with deformed relativistic symmetries and momentum dependence of the speed of photons. Our formalization is faithful to Einstein's program, with spacetime points viewed as an abstraction of physical events. The emerging picture imposes the renunciation of the idealization of absolutely coincident events, but is free from some pathologies which had been previously conjectured.
description: results generalized to 3+1D case; presentation streamlined
Similarities between the Epstein-Barr Virus (EBV) Nuclear Protein EBNA1 and the Pioneer Transcription Factor FoxA: Is EBNA1 a “Bookmarking” Oncoprotein that Alters the Host Cell Epigenotype?
Creators: name: Niller, Hans Helmut
name: Minarovits, Janos
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: DNA-looping; CpG-methylation; histone; chromatin; oriP
subject: 610 Medizin

description: EBNA1, a nuclear protein expressed in all EBV-associated neoplasms is indispensable for the maintenance of the viral episomes in latently infected cells. EBNA1 may induce genetic alterations by upregulating cellular recombinases, production of reactive oxygen species (ROS) and affecting p53 levels and function. All these changes may contribute to tumorigenesis. In this overview we focus, however, on the epigenetic alterations elicited by EBNA1 by drawing a parallel between EBNA1 and the FoxA family of pioneer transcription factors. Both EBNA1 and FoxA induce local DNA demethylation, nucleosome destabilization and bind to mitotic chromosomes. Local DNA demethylation and nucleosome rearrangement mark active promoters and enhancers. In addition, EBNA1 and FoxA, when associated with mitotic chromatin may “bookmark” active genes and ensure their reactivation in postmitotic cells (epigenetic memory). We speculate that DNA looping induced by EBNA1-EBNA1 interactions may reorganize the cellular genome. Such chromatin loops, sustained in mitotic chromatin similarly to the long-distance interactions mediated by the insulator protein CTCF, may also mediate the epigenetic inheritance of gene expression patterns. We suggest that EBNA1 has the potential to induce patho-epigenetic alterations contributing to tumorigenesis.