Longitudinal links between adolescent social anxiety and depressive symptoms: testing the mediational effects of cybervictimization

This study focuses on the temporal sequence between social anxiety and depressive symptoms, and whether cybervictimization might mediate these links. We used a longitudinal sample of 501 early adolescents (51.9% girls; Mage = 13.96) followed at three time points. Using a cross-lagged path model in MPlus, we found that social anxiety predicted depressive symptoms over time, but not the other way around. Time-1 depressive symptoms also predicted cybervictimization, but only for boys and not for girls. No mediating effects of cybervictimization emerged; however, Time-2 social anxiety was a significant mediator between Time-1 social anxiety and depressive symptoms, whereas Time-2 depressive symptoms significantly mediated the link between Time-1 social anxiety and Time-3 depressive symptoms. In sum, social anxiety was a strong predictor of depressive symptoms over time but not vice versa-irrespective of cybervictimization

Conductance anisotropy and linear magnetoresistance in La2-xSrxCuO4 thin films

We have performed a detailed study of conductance anisotropy and magnetoresistance (MR) of La2-xSrxCuO4 (LSCO) thin films (0.10 < x < 0.25). These two observables are promising for the detection of stripes. Subtle features of the conductance anisotropy are revealed by measuring the transverse resistance Rxy in zero magnetic field. It is demonstrated that the sign of Rxy depends on the orientation of the LSCO Hall bar with respect to the terrace structure of the substrate. Unit-cell-high substrate step edges must therefore be a dominant nucleation source for antiphase boundaries during film growth. We show that the measurement of Rxy is sensitive enough to detect the cubic-tetragonal phase transition of the SrTiO3(100) (STO) substrate at 105 K. The MR of LSCO thin films shows for 0.10 < x < 0.25 a non-monotonic temperature dependence, resulting from the onset of a linear term in the MR above 90 K. We show that the linear MR scales with the absolute Hall resistivity, with the constant of proportionality independent of temperature. Such scaling suggests that the linear MR originates from current distortions induced by structural or electronic inhomogeneities. The possible role of stripes for both the MR and the conductance anisotropy is discussed throughout the paper

Africa’s development banks: the urgent need for scale

There is a moral case for international provision of large-scale concessional funding to Africa. The continent is projected to feel the impacts of climate change the most, while having an estimated annual sustainable development goal financing gap of $200 billion. Nimrod Zalk writes that African countries should rapidly raise the capitalisation of development banks to enable higher levels of lending, and discusses way to do that

Social anxiety moderates the links between excessive chatting and compulsive Internet use

Excessive online chatting can lead to unwanted consequences such as compulsive Internet use over time. Not all adolescents use chatting for the same purpose, however, and these links may not be as pronounced for socially anxious adolescents as they likely communicate with others online in order to compensate for offline social inadequacies. The current study investigated whether social anxiety moderated the links between excessive chatting and compulsive Internet use over time. Using a sample of 523 early adolescents (269 girls; Mage = 14.00) from a 3-wave longitudinal study, the links between excessive chatting and compulsive Internet use were investigated via manifest autoregressive models, and moderating effects of social anxiety were tested via multiple-group comparison procedures. The results showed bidirectional links between excessive chatting and compulsive Internet use from Time 2–Time 3, as excessive chatting predicted more symptoms of compulsive Internet use, whereas compulsive Internet use predicted more excessive chatting – over and above the effects of gender. These links were present for adolescents low on social anxiety, but they were largely missing for highly socially anxious adolescents. Thus, social anxiety may have protective effects for early adolescents who spend too much time chatting online, as it may help reduce the risk of developing symptoms of compulsive Internet use

Diffuse axonal injury effect on myelinating cells and axons

There is no supporting evidence whether myelin degeneration in diffuse axonal injury (DAI) of the white matter is due to death of myelinating oligodendrocytes or secondary axotomy. Cortical neurons are not able to remain healthy in culture to have their axons myelinated. Dorsal root ganglion (DRG) neurons have been shown to be myelinated by cortical oligodendrocytes in culture. An in vitro stretch injury model was used to analyze the DRG axon pathology during and after injury. DRG myelinating Schwann cells are analyzed to demonstrate what is expected from injury to oligodendrocytes. DRG axons demonstrated a high tolerance to stretch injury compared to cortical axons, at strains up to 90% without disconnection. Axons showed delayed recovery of the developed distortions from injury to their preinjured orientation. Injured DRG axons developed swellings similar to those found along stretch injured cortical axons and in humans with DAI. The intracellular calcium level showed extracellular entry of calcium during injury and high sustained levels following a severe injury. Undifferentiated Schwann cells showed greater calcium influx from severe injury and the possible release of an extracellular signaling molecule increasing the calcium concentration in uninjured cells. Stretch injured differentiated Schwann cells demonstrated an increase in intracellular calcium at the time of injury and a gradual increase in non-injured cells after injury, possibly induced by extracellular signaling molecules and calcium ions traversing to non- injured cells through gap junctions

Shy adolescents' perceptions of parents' psychological control and emotional warmth: Examining bidirectional links

Two kinds of parental behaviors—psychological control and emotional warmth—have been linked with children's shy behaviors. The questions we addressed are whether this applies to adolescent shyness, and whether shyness in itself might also affect perceptions of parental behaviors. The participants were 916 seventh to ninth graders in a longitudinal project. We used a cross-lagged panel model with three time points in MPlus with adolescents' self-reports of shyness and perceptions of parents' psychological control (intrusive control and rejection) and warmth. Shyness predicted an increase in perceptions of intrusive control by parents at Time 2, which then predicted an increase in shyness at Time 3. Shyness also predicted an increase in perceived rejection by parents at Time 2. Finally, shyness predicted decreases in parental warmth at both time points. The effects did not differ for boys and girls. These results show that adolescent shyness predicts parental behaviors, though perhaps less strongly than in childhood. They also suggest some bidirectional effects in which perceived parental responses to shy youths might serve to strengthen the shyness

Banding the World Together; The Global Growth of Control Banding and Qualitative Occupational Risk Management

Control Banding (CB) strategies to prevent work-related illness and injury for 2.5 billion workers without access to health and safety professionals has grown exponentially this last decade. CB originates from the pharmaceutical industry to control active pharmaceutical ingredients without a complete toxicological basis and therefore no occupational exposure limits. CB applications have broadened into chemicals in general - including new emerging risks like nanomaterials and recently into ergonomics and injury prevention. CB is an action-oriented qualitative risk assessment strategy offering solutions and control measures to users through “toolkits”. Chemical CB toolkits are user-friendly approaches used to achieve workplace controls in the absence of firm toxicological and quantitative exposure information. The model (technical) validation of these toolkits is well described, however firm operational analyses (implementation aspects) are lacking. Consequentially, it is often not known if toolkit use leads to successful interventions at individual workplaces. This might lead to virtual safe workplaces without knowing if workers are truly protected. Upcoming international strategies from the World Health Organization Collaborating Centers request assistance in developing and evaluating action-oriented procedures for workplace risk assessment and control. It is expected that to fulfill this strategy’s goals, CB approaches will continue its important growth in protecting workers

Supergravity and M-Theory

Supergravity provides the effective field theories for string compactifications. The deformation of the maximal supergravities by non-abelian gauge interactions is only possible for a restricted class of charges. Generically these `gaugings' involve a hierarchy of p-form fields which belong to specific representations of the duality group. The group-theoretical structure of this p-form hierarchy exhibits many interesting features. In the case of maximal supergravity the class of allowed deformations has intriguing connections with M/string theory.Comment: 28 pages, LaTeX fil

IMPROVING KNOWLEDGE SHARING BEHAVIOUR WITHIN ORGANIZATIONS: TOWARDS A MODEL

Knowledge management is the process of capturing, storing, sharing and using organizational knowledge with the aim of improving organizational performance. A necessary precursor for successful knowledge management initiatives is knowledge exchange between employees. This exchange is voluntary and highly dependent on an individual’s willingness to share his/her knowledge. It thus becomes important to identify the factors motivating employees to share their knowledge. This research in progress draws on Locke and Latham’s Goal Setting Theory (1990) to propose a model explaining knowledge sharing behavior