Social Comparison and Self-Presentation on Social Media as Predictors of Depressive Symptoms

Social media, an online arena for social behaviors such as self-presentation and social comparison, may have effects on users’ mood and mental health. Favorably presenting oneself is linked to positive outcomes such as higher self-esteem, whereas social comparison, in general and specifically upward social comparison to higher-performing others, is related to feelings of inadequacy, envy, and depression. Social comparison may explain the “Facebook depression effect,” acting as a mediator between time spent on social media and depressive symptoms. A correlational study is proposed that will ask 200 participants to report their time spent on various social media sites, self-presentation of themselves and their “friends,” social comparison orientation, and depressive symptoms. Expected findings are that time spent on social media and the degree of others’ perceived self-presentation will each be positively correlated with depression, and these relationships will be mediated by social comparison. This study will demonstrate that people feel depressed when they spend time on social media because they are frequently exposed to the self-enhancing images of others, which provides an opportunity for negative social comparison

Ab-initio Molecular Dynamics study of electronic and optical properties of silicon quantum wires: Orientational Effects

We analyze the influence of spatial orientation on the optical response of hydrogenated silicon quantum wires. The results are relevant for the interpretation of the optical properties of light emitting porous silicon. We study (111)-oriented wires and compare the present results with those previously obtained within the same theoretical framework for (001)-oriented wires [F. Buda {\it et al.}, {\it Phys. Rev. Lett.} {\bf 69}, 1272, (1992)]. In analogy with the (001)-oriented wires and at variance with crystalline bulk silicon, we find that the (111)-oriented wires exhibit a direct gap at ${\bf k}=0$ whose value is largely enhanced with respect to that found in bulk silicon because of quantum confinement effects. The imaginary part of the dielectric function, for the external field polarized in the direction of the axis of the wires, shows features that, while being qualitatively similar to those observed for the (001) wires, are not present in the bulk. The main conclusion which emerges from the present study is that, if wires a few nanometers large are present in the porous material, they are optically active independently of their specific orientation.Comment: 14 pages (plus 6 figures), Revte

Executable Architectures Using Cuckoo Search Optimization Coupled with OPM and CPN-A Module: A New Meta-Architecture Model for FILA SoS

Understanding System of Systems (SoS) requires novel ways to apply systems engineering processes. Acknowledged SoS have recognized objectives, a designated manager and resources for the SoS. The goal of this research is to develop a proof of concept tool suite for Acknowledged SoS systems simulation. This suite is named flexible, intelligent and learning architectures for System of Systems (FILA-SoS). FILA-SoS assists the SoS manager in architecture generation, selection, and implementation working as an aid for decision making. Binary cuckoo search constrained optimization is used to generate meta-architectures which are evaluated by a fuzzy assessor for quality assurance. The architecture is then converted into an executable structure using Object Process Methodology (OPM) and Colored Petri Nets (CPN). A hybrid methodology comprising of OPM and CPN approach is implemented for simulating the acquisition environment. Initial application for a Search and Rescue (SAR) SoS, consisting of 25 individual systems with ten capabilities gave promising results

Spin torque resonant vortex core expulsion for an efficient radio-frequency detection scheme

Spin-polarised radio-frequency currents, whose frequency is equal to that of the gyrotropic mode, will cause an excitation of the core of a magnetic vortex confined in a magnetic tunnel junction. When the excitation radius of the vortex core is greater than that of the junction radius, vortex core expulsion is observed, leading to a large change in resistance, as the layer enters a predominantly uniform magnetisation state. Unlike the conventional spin-torque diode effect, this highly tunable resonant effect will generate a voltage which does not decrease as a function of rf power, and has the potential to form the basis of a new generation of tunable nanoscale radio-frequency detectors

The Bari Manifesto : An interoperability framework for essential biodiversity variables

Essential Biodiversity Variables (EBV) are fundamental variables that can be used for assessing biodiversity change over time, for determining adherence to biodiversity policy, for monitoring progress towards sustainable development goals, and for tracking biodiversity responses to disturbances and management interventions. Data from observations or models that provide measured or estimated EBV values, which we refer to as EBV data products, can help to capture the above processes and trends and can serve as a coherent framework for documenting trends in biodiversity. Using primary biodiversity records and other raw data as sources to produce EBV data products depends on cooperation and interoperability among multiple stakeholders, including those collecting and mobilising data for EBVs and those producing, publishing and preserving EBV data products. Here, we encapsulate ten principles for the current best practice in EBV-focused biodiversity informatics as 'The Bari Manifesto', serving as implementation guidelines for data and research infrastructure providers to support the emerging EBV operational framework based on trans-national and cross-infrastructure scientific workflows. The principles provide guidance on how to contribute towards the production of EBV data products that are globally oriented, while remaining appropriate to the producer's own mission, vision and goals. These ten principles cover: data management planning; data structure; metadata; services; data quality; workflows; provenance; ontologies/vocabularies; data preservation; and accessibility. For each principle, desired outcomes and goals have been formulated. Some specific actions related to fulfilling the Bari Manifesto principles are highlighted in the context of each of four groups of organizations contributing to enabling data interoperability - data standards bodies, research data infrastructures, the pertinent research communities, and funders. The Bari Manifesto provides a roadmap enabling support for routine generation of EBV data products, and increases the likelihood of success for a global EBV framework.Peer reviewe

Released micromachined beams utilizing laterally uniform porosity porous silicon

© 2014, Sun et al.; licensee Springer. Abstract: Suspended micromachined porous silicon beams with laterally uniform porosity are reported, which have been fabricated using standard photolithography processes designed for compatibility with complementary metal-oxide-semiconductor (CMOS) processes. Anodization, annealing, reactive ion etching, repeated photolithography, lift off and electropolishing processes were used to release patterned porous silicon microbeams on a Si substrate. This is the first time that micromachined, suspended PS microbeams have been demonstrated with laterally uniform porosity, well-defined anchors and flat surfaces. PACS: 81.16.-c; 81.16.Nd; 81.16.R

Simultaneous control of magnetic topologies for reconfigurable vortex arrays

The topological spin textures in magnetic vortices in confined magnetic elements offer a platform for understanding the fundamental physics of nanoscale spin behavior and the potential of harnessing their unique spin structures for advanced magnetic technologies. For magnetic vortices to be practical, an effective reconfigurability of the two topologies of magnetic vortices, that is, the circularity and the polarity, is an essential prerequisite. The reconfiguration issue is highly relevant to the question of whether both circularity and polarity are reliably and efficiently controllable. In this work, we report the first direct observation of simultaneous control of both circularity and polarity by the sole application of an in-plane magnetic field to arrays of asymmetrically shaped permalloy disks. Our investigation demonstrates that a high degree of reliability for control of both topologies can be achieved by tailoring the geometry of the disk arrays. We also propose a new approach to control the vortex structures by manipulating the effect of the stray field on the dynamics of vortex creation. The current study is expected to facilitate complete and effective reconfiguration of magnetic vortex structures, thereby enhancing the prospects for technological applications of magnetic vortices.ope