Bullying in a networked era: a literature review

This research update presents an aggregation and summary of recent academic literature on youth bullying. The purpose of this document is to “translate” scholarly research for a concerned public audience, which may include but is not limited to parents, caregivers, educators, and practitioners. This translation highlights recent findings and developments in the literature and makes them accessible to the informed but non-expert reader. The document’s two guiding questions are “What is bullying?” (Section I) and “What can be done about bullying?” (Section II). Section I begins with a brief overview of key definitions and related research conversations and then addresses bullying’s prevalence, the types of individuals involved in bullying, the characteristics of individuals involved and the consequences of their involvement, and community-level dynamics related to bullying. Section II covers four areas where action has been taken to address problems associated with bullying – school policy, curricula, school climate, and parents – and ends on a note about approaches that mix or cut across these areas. The purpose is to render lessons learned from research and assessment accessible to those interested in deepening or expanding their knowledge of bullying-related issues

Concept of a novel fast neutron imaging detector based on THGEM for fan-beam tomography applications

The conceptual design and operational principle of a novel high-efficiency, fast neutron imaging detector based on THGEM, intended for future fan-beam transmission tomography applications, is described. We report on a feasibility study based on theoretical modeling and computer simulations of a possible detector configuration prototype. In particular we discuss results regarding the optimization of detector geometry, estimation of its general performance, and expected imaging quality: it has been estimated that detection efficiency of around 5-8% can be achieved for 2.5MeV neutrons; spatial resolution is around one millimeter with no substantial degradation due to scattering effects. The foreseen applications of the imaging system are neutron tomography in non-destructive testing for the nuclear energy industry, including examination of spent nuclear fuel bundles, detection of explosives or drugs, as well as investigation of thermal hydraulics phenomena (e.g., two-phase flow, heat transfer, phase change, coolant dynamics, and liquid metal flow).Comment: 11 Pages; 6 Figures; Proceeding of the International Workshop on Fast Neutron Detectors and Application FNDA2011, Ein Gedi, Israel, November 2011. Published on the Journal of Instrumentation; 2012 JINST 7 C0205

First performance evaluation of a Multi-layer Thick Gaseous Electron Multiplier with in-built electrode meshes - MM-THGEM

We describe a new micro-pattern gas detector structure comprising a multi-layer hole-type multiplier (M-THGEM) combined with two in-built electrode meshes: the Multi-Mesh THGEM-type multiplier (MM-THGEM). Suitable potential differences applied between the various electrodes provide an efficient collection of ionization electrons within the MM-THGEM holes and a large charge avalanche multiplication between the meshes. Different from conventional hole-type multipliers (e.g. Gas Electron Multipliers - GEMs, Thick Gas Electron Multipliers - THGEMs, etc.), which are characterized by a variable (dipole-like) field strength inside the avalanche gap, electrons in MM-THGEMs are largely multiplied by a strong uniform field established between the two meshes, like in the parallel-plate avalanche geometry. The presence of the two meshes within the holes allows for the trapping of a large fraction of the positive ions that stream back to the drift region. A gas gain above 10^5 has been achieved for single photo-electron detection with a single MM-THGEM in Ar/(10%)CH4 and He/(10%)CO2, at standard conditions for temperature and pressure. When the MM-THGEM is coupled to a conventional THGEM and used as first cascade element, the maximum achievable gains reach values above 10^6 in He/(10%)CO2, while the IBF approaches of 1.5% in the case of optimum detector-bias configuration. This IBF value is several times lower compared to the one obtained by a double GEM/THGEM detector (5-10%), and equivalent to the performance attained by a Micromegas detector.Comment: 11 pages, 8 figures. Submitted to JINS

Youth and Digital Media: From Credibility to Information Quality

Building upon a process-and context-oriented information quality framework, this paper seeks to map and explore what we know about the ways in which young users of age 18 and under search for information online, how they evaluate information, and how their related practices of content creation, levels of new literacies, general digital media usage, and social patterns affect these activities. A review of selected literature at the intersection of digital media, youth, and information quality -- primarily works from library and information science, sociology, education, and selected ethnographic studies -- reveals patterns in youth's information-seeking behavior, but also highlights the importance of contextual and demographic factors both for search and evaluation. Looking at the phenomenon from an information-learning and educational perspective, the literature shows that youth develop competencies for personal goals that sometimes do not transfer to school, and are sometimes not appropriate for school. Thus far, educational initiatives to educate youth about search, evaluation, or creation have depended greatly on the local circumstances for their success or failure

Submodularity of Energy Related Controllability Metrics

The quantification of controllability and observability has recently received new interest in the context of large, complex networks of dynamical systems. A fundamental but computationally difficult problem is the placement or selection of actuators and sensors that optimize real-valued controllability and observability metrics of the network. We show that several classes of energy related metrics associated with the controllability Gramian in linear dynamical systems have a strong structural property, called submodularity. This property allows for an approximation guarantee by using a simple greedy heuristic for their maximization. The results are illustrated for randomly generated systems and for placement of power electronic actuators in a model of the European power grid.Comment: 7 pages, 2 figures; submitted to the 2014 IEEE Conference on Decision and Contro

Parents, teens, and online privacy

This report looks at some steps parents are taking to observe, discuss, and check up on their children’s digital footprints. Most parents of teenagers are concerned about what their teenage children do online and how their behavior could be monitored by others.  81% of parents of online teens say they are concerned about how much information advertisers can learn about their child’s online behavior, with some 46% being “very” concerned. 72% of parents of online teens are concerned about how their child interacts online with people they do not know, with some 53% of parents being “very” concerned

EGFR inhibitor as second-line therapy in a patient with mutant RAS metastatic colorectal cancer: circulating tumor DNA to personalize treatment

A 47-year-old male patient presented in March 2016 to our unit with a palpable painless left supraclavicular mass. A whole-body contrastenhanced computed tomography (CT) scan revealed a left supraclavicular lymphadenopathy, transverse colon thickening (3 cm), multiple chest and abdominal lymphadenopathies, and peritoneal carcinomatosis. Colonoscopy revealed a bleeding area at 15 cm from the anal verge; biopsy was performed, and the result was negative for a primary cancer

On Submodularity and Controllability in Complex Dynamical Networks

Controllability and observability have long been recognized as fundamental structural properties of dynamical systems, but have recently seen renewed interest in the context of large, complex networks of dynamical systems. A basic problem is sensor and actuator placement: choose a subset from a finite set of possible placements to optimize some real-valued controllability and observability metrics of the network. Surprisingly little is known about the structure of such combinatorial optimization problems. In this paper, we show that several important classes of metrics based on the controllability and observability Gramians have a strong structural property that allows for either efficient global optimization or an approximation guarantee by using a simple greedy heuristic for their maximization. In particular, the mapping from possible placements to several scalar functions of the associated Gramian is either a modular or submodular set function. The results are illustrated on randomly generated systems and on a problem of power electronic actuator placement in a model of the European power grid.Comment: Original arXiv version of IEEE Transactions on Control of Network Systems paper (Volume 3, Issue 1), with a addendum (located in the ancillary documents) that explains an error in a proof of the original paper and provides a counterexample to the corresponding resul