A process model of cyberbullying in adolescence

Cyberbullying is an emerging form of aggression that utilizes information and communication technologies (ICTs). While cyberbullying incidents attract considerable attention, research on the causes and psychosocial predictors of cyberbullying is still limited. The present study used an integrated theoretical model incorporating empathy, moral disengagement, and social cognitions related to cyberbullying. Structured questionnaires were administered to 355 randomly selected adolescents (M = 14.7, SD = 1.20). Linear regression analysis showed that social norms, prototype similarity and situational self-efficacy directly predicted cyberbullying expectations. Multiple mediation modelling indicated that normative influences mediated the effects of moral disengagement and affective empathy on cyberbullying expectations. These findings provide valuable information regarding the effect of both distal and proximal risk factors for cyberbullying in adolescence, highlight the relationship between normative processes and moral self-regulation, and set the basis for related educational and preventive interventions.     

Sorption of reactive dyes from aqueous solutions by ordered hexagonal and disordered mesoporous carbons

In the present study two synthetic mesoporous carbons, a highly ordered CMK-3 sample with hexagonal structure and a disordered mesoporous carbon (denoted DMC) were investigated for the sorption of Remazol Red 3BS (C.I. 239) dye in comparison to three commercial activated carbons and a HMS mesoporous silica with a wormhole pore structure. The structural, porosity and surface characteristics of the materials were evaluated using XRD, TEM, N₂ porosimetry, FT-IR spectroscopy and zeta-potential measurements. Optimal dye sorption occurred at pH ～2. Equilibrium sorption data followed the Langmuir model and showed that the two synthetic mesoporous carbons exhibit higher sorption capacities (q_max ～ 500–580 mg/g at 25 °C) in comparison to the commercial activated carbons which possessed either microporous (Takeda 5A and Calgon carbon) or combined micro-/mesoporous (Norit SAE-2) structures and to the HMS mesoporous silica. Thermodynamic parameters as the change in free energy, enthalpy, and entropy of sorption were also estimated. Kinetic studies were carried out and showed a rapid sorption of dye in the first ca. 30 min while equilibrium was reached after ca. 3 h. The sorption kinetics of dye was best described by a second-order kinetic model. A surfactant enhanced carbon regeneration (SECR) technique was used to regenerate the dye-loaded carbon sorbents.     

Aging of packaging films in the marine environment

The present article examines the aging behavior in the marine environment of some representative flexible plastic packaging films including supermarket plastic bags made of low‐density polyethylene (LDPE), polyethylene terephthalate (PET) films, polyamide–polyethylene (PAPE) films and films made of a material under the commercial name Mater‐Bi®. The effect of aging was studied by Fourier transform infrared spectroscopy, differential scanning calorimetry, and tension including creep‐recovery tests. The polyethylene films were not hydrolytically degraded during aging in seawater, and the polyethylene chains did not undergo any substantial chain scission. The PET films after exposure for 8 months in seawater did not suffer any substantial degradation, and the PET chains were plasticized by the absorbed water. After prolonged exposure to seawater (12 months), the PET films started to degrade. The PAPE film underwent extensive chemical and structural changes during aging in seawater as result of plasticization and hydrolysis of the polyamide (PA) component in combination with an eventual loosening of the tie layer. Mater‐Bi® film underwent a severe deterioration during aging in seawater due to the hydrolysis of the starch and polycaprolactone components. All films exhibited a marked degradation of their tensile properties after exposure to accelerating aging conditions under UV radiation. POLYM. ENG. SCI., 59:E432–E441, 2019. © 2019 Society of Plastics Engineers     

The Impact of Angiogenesis in the Most Common Salivary Gland Malignant Tumors

Salivary gland carcinomas (SGCs) represent a group of rare tumors, with complete surgical resection being the main treatment option. Therapeutic armory for cases of locally aggressive, recurrent, and/or metastatic SGCs, though, remains poor since they exhibit high rates of resistance to systematic therapy. Angiogenesis is considered one of the contemporary hallmarks of cancer and anti-angiogenic factors have already been approved for the treatment of several cancer types. This review aims to summarize, in a histotype-specific manner, the most current available data on the angiogenic factors implicated in SGC angiogenesis, in order to highlight the differences between the most common SGC histotypes and the factors that may have a potential role as therapeutic targets.     

Evaluation of three methods for retrospective correction of vignetting on medical microscopy images utilizing two open source software tools

Correction of vignetting on images obtained by a digital camera mounted on a microscope is essential before applying image analysis. The aim of this study is to evaluate three methods for retrospective correction of vignetting on medical microscopy images and compare them with a prospective correction method. One digital image from four different tissues was used and a vignetting effect was applied on each of these images. The resulted vignetted image was replicated four times and in each replica a different method for vignetting correction was applied with fiji and gimp software tools. The highest peak signal-to-noise ratio from the comparison of each method to the original image was obtained from the prospective method in all tissues. The morphological filtering method provided the highest peak signal-to-noise ratio value amongst the retrospective methods. The prospective method is suggested as the method of choice for correction of vignetting and if it is not applicable, then the morphological filtering may be suggested as the retrospective alternative method.     

Effect of organomodified clay on the reaction kinetics,properties and thermal degradation of nanocomposites based on poly(styrene‐co‐ethyl methacrylate)

In this research, synthesis of novel nanocomposites based on a poly(styrene‐co‐ethyl methacrylate) copolymer matrix was investigated with different types and amounts of organomodified montmorillonite (MMT) clays. The in situ polymerization technique was selected with dispersion of the MMT nanoparticles into the comonomer mixture and subsequent bulk radical polymerization. Reaction kinetics was measured gravimetrically and it was found that the existence of rigid phenyl rings in the organomodifier may result in a hindered reaction rate especially at high clay loadings. Structural characteristics of the nanocomposites formed were verified with XRD and Fourier transform infrared analysis and mainly intercalated/partially exfoliated structures were verified; their glass transition temperature was measured with DSC, and their molecular weight distribution and average molecular weights were measured with gel permeation chromatography. The latter was also used to measure the variation of the copolymer average molecular weight with conversion. Slightly higher average molecular weight and T_g values for the copolymer in the nanocomposites were measured, compared with neat copolymer. The thermal stability of the nanocomposites was measured with TGA and found to be significantly improved. One‐step degradation revealed the existence of macromolecular chains without defective structures. Finally, pyrolysis of the nanocomposite copolymers resulted in the production of both comonomers in high amounts, followed by some dimers or trimers. © 2013 Society of Chemical Industry     

Influence of homocharges and nanoparticles in electrical tree propagation under DC voltage application

The influence of nanoparticles and homocharges on the propagation of electrical treeing in polymer insulation is examined for a needle-plane electrode arrangement. A simulation is carried out using a model based on Cellular Automata (CA). A DC voltage application on the needle electrode is assumed. Nanoparticles are introduced in the polymer matrix in the vicinity of the needle electrode, and simulations with different homocharge densities are performed. It is confirmed that the propagation of electrical trees is hindered by the presence of nanoparticles and homocharges. A larger quantity of homocharges forms a barrier to the injection of charge carriers in the nanocomposite sample. Electrical trees seem to go around and/or stop at nanoparticles and thus, their propagation becomes more difficult. In other words, the proposed simulations show that electrical trees follow a tortuous path, avoiding the nanoparticles.     

Enacting new temporal boundaries: the role of mobile phones

This paper examines how the use of mobile phones influences the temporal boundaries that people enact in order to regulate and coordinate their work and non-work activities. We investigate both the structural and interpretive aspects of socio-temporal order, so as to gain a fuller appreciation of the changes induced by the use of mobile phones. With specific reference to professionals working in traditional, physically based and hierarchically structured organizations, we found that mobile phone users are becoming more vulnerable to organizational claims and that as a result ‘the office’ is always present as professionals, because of the use of mobile phones, become available ‘anytime’. This is enabled by the characteristics of the technology itself but also by users’ own behaviour. In the paper, we discuss the properties of the emerging socio-temporal order and show how mobile phones may render the management of the social spheres in which professionals participate more challenging.     

User perceptions of 3D online store designs: an experimental investigation

Information Systems and e-Business Management - The increasing adoption of three-dimensional (3D) virtual reality technologies in business practices requires an interdisciplinary research approach...