Rounding Algorithms for a Geometric Embedding of Minimum Multiway Cut

The multiway-cut problem is, given a weighted graph and k >= 2 terminal nodes, to find a minimum-weight set of edges whose removal separates all the terminals. The problem is NP-hard, and even NP-hard to approximate within 1+delta for some small delta > 0. Calinescu, Karloff, and Rabani (1998) gave an algorithm with performance guarantee 3/2-1/k, based on a geometric relaxation of the problem. In this paper, we give improved randomized rounding schemes for their relaxation, yielding a 12/11-approximation algorithm for k=3 and a 1.3438-approximation algorithm in general. Our approach hinges on the observation that the problem of designing a randomized rounding scheme for a geometric relaxation is itself a linear programming problem. The paper explores computational solutions to this problem, and gives a proof that for a general class of geometric relaxations, there are always randomized rounding schemes that match the integrality gap.Comment: Conference version in ACM Symposium on Theory of Computing (1999). To appear in Mathematics of Operations Researc

Evaluación del impacto de la colaboración internacional sobre el aprendizaje de la geografía

El Center for Global Geography Education (CGGE) (Centro para la Enseñanza de la Geografía Mundial) está constituido por una serie de módulos en línea que investigan temas relacionados con la geografía, permitiendo el análisis y la discusión en grupo entre diversos equipos de estudiantes no licenciados. Mediante la utilización de los datos obtenidos a partir de experimentos llevados a cabo en diez países, hemos evaluado la efectividad de los módulos en la mejora de la compresión de los estudiantes de conceptos geográficos y la valoración de las perspectivas transculturales sobre estos temas. El análisis de los datos cualitativos y cuantitativos puso al descubierto que el CGGE alcanzó sus objetivos de reforzar los conocimientos y las competencias geográficas. El diseño de los módulos y de su colaboración internacional interesó en gran medida a estudiantes y profesores. Establecemos revisiones específicas de sus contenidos a fin de fomentar intercambios más intensos de las perspectivas internacionales entre estudiantes universitarios.The Center for Global Geography Education (CGGE) is a set of online modules exploring geographic issues, which allow collaborative analysis and discussion between international teams of undergraduates. Using data from trials held in 10 countries, we evaluated the modules' effectiveness in improving student understanding of geographic concepts and appreciation for cross-cultural perspectives on the issues. Analysis of qualitative and quantitative data revealed that CGGE achieved its aims of enhancing geographic knowledge and skills. The modules and their international collaboration design inspired high interest among students and professors. We identify specific revisions to their content in order to foster deeper exchanges of international perspectives among university students.El Center for Global Geography Education (CGGE) (Centro para la Enseñanza de la Geografía Mundial) está constituido por una serie de módulos en línea que investigan temas relacionados con la geografía, permitiendo el análisis y la discusión en grupo entre diversos equipos de estudiantes no licenciados. Mediante la utilización de los datos obtenidos a partir de experimentos llevados a cabo en diez países, hemos evaluado la efectividad de los módulos en la mejora de la compresión de los estudiantes de conceptos geográficos y la valoración de las perspectivas transculturales sobre estos temas. El análisis de los datos cualitativos y cuantitativos puso al descubierto que el CGGE alcanzó sus objetivos de reforzar los conocimientos y las competencias geográficas. El diseño de los módulos y de su colaboración internacional interesó en gran medida a estudiantes y profesores. Establecemos revisiones específicas de sus contenidos a fin de fomentar intercambios más intensos de las perspectivas internacionales entre estudiantes universitarios

STUDENTS’ PERCEPTION OF ONLINE GROSS ANATOMY LABORATORY CLASSES VIA ZOOM TECHNOLOGY

BACKGROUND During the 1st semester of 2020 the unit ‘Functional Anatomy of the Trunk’ was re-designed and taught online, in response to the COVID-19 virus lockdown. AIMS The aim of this study was to investigate whether the use of computer based online support tools (as replacement of the traditional cadaver based laboratory learning), in conjunction with a focused period of synchronous Zoom delivery, achieved student outcomes and learning experience. DESCRIPTION OF INTERVENTION The curriculum of the unit deals with the gross anatomy of the human trunk. The unit was taught in small groups (around 30 students) and entirely online with Zoom technology. DESIGN AND METHODS N=41 first year students participated in this study and were invited at the conclusion of the unit to complete an anonymous opinion-based survey (via Qualtrics). Student grades and learning management system analytics was also analysed. RESULTS Preliminary results indicate that students’ perception of the online gross anatomy laboratory learning was positive and extended their learning. However, the online learning platform has its limitations, not using real bodies makes it harder to appreciate the 3D relationships between structure and function. CONCLUSIONS Students’ perception of online learning as a replacement of the traditional gross anatomy laboratory was surprisingly positive. Most agreed that it provided valuable insights and improved their understanding of anatomy as well as helped with the application of anatomical knowledge. Equally so, they strongly agreed that the online 2D learning experience was less engaging and interesting than learning using real bodies

Assessment & Planning for the Department of Geography, GIS, & Sustainability

The purpose of this project and requested funding was to support participation in the NAGT traveling workshop. The Dean\u27s office in the College of Humanities and Social Sciences approved the use of funds to support the actual workshop, so the requested funding from the Assessment Mini-Grants program was to provide stipends and food for faculty and students in attendance. The overarching objective of the workshop was to facilitate the collaborative development of ENST curriculum, assessment, and planning. The following were workshop specific goals: Evaluate and Revise ENST Student Learning Outcomes, including: Curriculum Mapping Alignment with Institutional Learning Outcomes Create a program Vision, Mission, Goals, and 5-year plan Create an Assessment Plan aligned with program vision and student learning outcome

‘None of Us Sets Out To Hurt People’: The Ethical Geographer and Geography Curricula in Higher Education

This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Geography in Higher Education on 22nd January 2008, available online: https://doi.org/10.1080/03098260701731462This paper examines ethics in learning and teaching geography in higher education. It proposes a pathway towards curriculum and pedagogy that better incorporates ethics in university geography education. By focusing on the central but problematic relationships between (i) teaching and learning on the one hand and research on the other, and (ii) ethics and geography curricula, the authors’ reflections illustrate how ethics may be better recognized within those curricula. They discuss issues affecting teaching and learning about ethics in geography, and through identification of a range of examples identify ways to enhance the integration of ethical issues into university geography curricula

Eosinophilic Gastroenteritis with Eosinophilic Dermatitis

Eosinophilic gastroenteritis (EG) is characterized by eosinophilic infiltration of the bowel wall and variable gastrointestinal manifestations. Clinicians should have a high index of suspicion for EG when faced with gastrointestinal symptoms and peripheral eosinophilia to avoid incorrect diagnosis and inappropriate treatments. A 24-year-old woman was admitted to our hospital complaining of acute right lower quadrant abdominal pain and a laparoscopic appendectomy performed for a presumed diagnosis of an acute appendicitis. However, the procedure revealed bowel edema and a moderate amount of ascites without evidence of a suppurative appendicitis. Postoperatively, she showed persistent and progressive eosinophilia, exudative eosinophilic ascites, eosinophilic infiltration of the resected appendix wall, and eosinophilic infiltration of gastroduodenal mucosa. A punch biopsy of the abdominal skin also revealed inflammation with marked eosinophilic infiltration of the skin. She recovered after the treatment with a low dose of steroid for the EG with eosinophilic dermatitis. EG with eosinophilic dermatitis has not been reported yet and is considered fortuitous in this case

Turning evidence into recommendations: Protocol of a study guideline development groups

<p>Abstract</p> <p>Background</p> <p>Health care practice based on research evidence requires that evidence is synthesised, and that recommendations based on this evidence are implemented. It also requires an intermediate step: translating synthesised evidence into practice recommendations. There is considerable literature on evidence synthesis and implementation, but little on how guideline development groups (GDGs) produce recommendations. This is a complex process, with many influences on communication and decision-making, <it>e.g</it>., the quality of evidence, methods of presentation, practical/resource constraints, individual values, professional and scientific interests, social and psychological processes. To make this process more transparent and potentially effective, we need to understand these influences. Psychological theories of decision-making and social influence provide a framework for this understanding.</p> <p>Objectives</p> <p>This study aims to investigate the processes by which GDGs formulate recommendations, drawing on psychological theories of decision-making and social influence. The findings will potentially inform the further evolution of GDG methods, such as choice of members and procedures for presenting evidence, conducting discussion and formulating recommendations.</p> <p>Methods</p> <p>Longitudinal observation of the meetings of three National Institute of Health and Clinical Excellence (NICE) GDGs, one from each of acute, mental health and public health, will be tape recorded and transcribed. Interviews with a sample of GDG members at the beginning, middle, and end of the GDG's work will be recorded and transcribed. Site documents including relevant e-mail interchanges, GDG meeting minutes, and stakeholders' responses to the drafts of the recommendations will be collected. Data will be selected for analysis if they refer to either evidence or recommendations; the focus is on "hot spots", <it>e.g</it>., dilemmas, conflicts, and uncertainty. Data will be analysed thematically and by content analysis, drawing on psychological theories of decision-making and social influence.</p

Giant Mesenteric Lipoma As an Unusual Cause of Abdominal Pain: A Case Report and a Review of the Literature

We report a rare case of giant mesenteric lipoma presenting with colicky abdominal pain. A 29-yr-old woman underwent laparoscopic resection for a giant mesenteric lipoma causing compression of the ileal loop. The resected ileal segment was encased by a giant fatty tissue, and normal mucosal fold patterns of the resected ileum were effaced by the mass. Microscopically, the mass was characterized by homogenous mature adipose tissue without cellular atypia, which was compatible with the diagnosis of a mesenteric lipoma. Despite the benign nature of this tumor, total excision with or without the affected intestinal loop should be considered if intestinal symptoms such as abdominal pain are present

Focusing and Calibration of Large Scale Network Sensors using GraphBLAS Anonymized Hypersparse Matrices

Defending community-owned cyber space requires community-based efforts. Large-scale network observations that uphold the highest regard for privacy are key to protecting our shared cyberspace. Deployment of the necessary network sensors requires careful sensor placement, focusing, and calibration with significant volumes of network observations. This paper demonstrates novel focusing and calibration procedures on a multi-billion packet dataset using high-performance GraphBLAS anonymized hypersparse matrices. The run-time performance on a real-world data set confirms previously observed real-time processing rates for high-bandwidth links while achieving significant data compression. The output of the analysis demonstrates the effectiveness of these procedures at focusing the traffic matrix and revealing the underlying stable heavy-tail statistical distributions that are necessary for anomaly detection. A simple model of the corresponding probability of detection ($p_{\rm d}$) and probability of false alarm ($p_{\rm fa}$) for these distributions highlights the criticality of network sensor focusing and calibration. Once a sensor is properly focused and calibrated it is then in a position to carry out two of the central tenets of good cybersecurity: (1) continuous observation of the network and (2) minimizing unbrokered network connections.Comment: Accepted to IEEE HPEC, 9 pages, 12 figures, 1 table, 63 references, 2 appendice

The Atacama Cosmology Telescope: Extragalactic Sources at 148 GHz in the 2008 Survey

We report on extragalactic sources detected in a 455 square-degree map of the southern sky made with data at a frequency of 148 GHz from the Atacama Cosmology Telescope 2008 observing season. We provide a catalog of 157 sources with flux densities spanning two orders of magnitude: from 15 to 1500 mJy. Comparison to other catalogs shows that 98% of the ACT detections correspond to sources detected at lower radio frequencies. Three of the sources appear to be associated with the brightest cluster galaxies of low redshift X-ray selected galaxy clusters. Estimates of the radio to mm-wave spectral indices and differential counts of the sources further bolster the hypothesis that they are nearly all radio sources, and that their emission is not dominated by re-emission from warm dust. In a bright (>50 mJy) 148 GHz-selected sample with complete cross-identifications from the Australia Telescope 20 GHz survey, we observe an average steepening of the spectra between 5, 20, and 148 GHz with median spectral indices of $\alpha_{\rm 5-20} = -0.07 \pm 0.06$, $\alpha_{\rm 20-148} = -0.39 \pm0.04$, and $\alpha_{\rm 5-148} = -0.20 \pm 0.03$. When the measured spectral indices are taken into account, the 148 GHz differential source counts are consistent with previous measurements at 30 GHz in the context of a source count model dominated by radio sources. Extrapolating with an appropriately rescaled model for the radio source counts, the Poisson contribution to the spatial power spectrum from synchrotron-dominated sources with flux density less than 20 mJy is C^{\rm Sync} = (2.8 \pm 0.3) \times 10^{-6} \micro\kelvin^2.Comment: Accepted to Ap