A longitudinal study of adolescent Internet addiction: the role of conscientiousness and classroom hostility

Over the last decade, research on Internet Addiction (IA) has increased. However, almost all studies in this area are cross-sectional and do not examine the context in which internet use takes place. Therefore, a longitudinal study examined the role of conscientiousness (as a personality trait) and classroom hostility (as a contextual factor) in the development of IA. The participants comprised 648 adolescents and were assessed over a two-year period (while aged 16–18 years). A three-level hierarchical linear model was carried out on the data collected. Findings revealed that: (i) lower conscientiousness was associated with IA and this did not change over time; and (ii) although being in a more hostile classroom did not initially have a significant effect, it increased girls’ IA vulnerability over time and functioned protectively for boys. Results indicated that the contribution of individual and contextual IA factors may differ across genders and over time. More specifically, although the protective effect of conscientiousness appeared to hold, the over-time effect of classroom hostility increased the risk of IA for girls. These findings are discussed in relation to the psychological literature. The study’s limitations and implications are also discussed

Using bacterial extract along with differential gene expression in Acropora millepora Larvae to decouple the processes of attachment and metamorphosis

Biofilms of the bacterium Pseudoalteromonas induce metamorphosis of acroporid coral larvae. The bacterial metabolite tetrabromopyrrole (TBP), isolated from an extract of Pseudoalteromonas sp. associated with the crustose coralline alga (CCA) Neogoniolithon fosliei, induced coral larval metamorphosis (100%) with little or no attachment (0-2%). To better understand the molecular events and mechanisms underpinning the induction of Acropora millepora larval metamorphosis, including cell proliferation, apoptosis, differentiation, migration, adhesion and biomineralisation, two novel coral gene expression assays were implemented. These involved the use of reverse-transcriptase quantitative PCR (RT-qPCR) and employed 47 genes of interest (GOI), selected based on putative roles in the processes of settlement and metamorphosis. Substantial differences in transcriptomic responses of GOI were detected following incubation of A. millepora larvae with a threshold concentration and 10-fold elevated concentration of TBP-containing extracts of Pseudoalteromonas sp. The notable and relatively abrupt changes of the larval body structure during metamorphosis correlated, at the molecular level, with significant differences (p<0.05) in gene expression profiles of 24 GOI, 12 hours post exposure. Fourteen of those GOI also presented differences in expression (p<0.05) following exposure to the threshold concentration of bacterial TBP-containing extract. The specificity of the bacterial TBP-containing extract to induce the metamorphic stage in A. millepora larvae without attachment, using a robust, low cost, accurate, ecologically relevant and highly reproducible RT-qPCR assay, allowed partially decoupling of the transcriptomic processes of attachment and metamorphosis. The bacterial TBP-containing extract provided a unique opportunity to monitor the regulation of genes exclusively involved in the process of metamorphosis, contrasting previous gene expression studies that utilized cues, such as crustose coralline algae, biofilms or with GLW-amide neuropeptides that stimulate the entire onset of larval metamorphosis and attachment. © 2012 Siboni et al

Jatrophane diterpenes as modulators of multidrug resistance. Advances of structure-activity relationships and discovery of the potent lead pepluanin A

From the whole plant of Euphorbia peplus L., five new diterpenes based on a jatrophane skeleton (pepluanins A-E, 1-5) were isolated, together with two known analogues (6 and 7), which served to divulge in detail the structure-activity relationships within this class of P-glycoprotein inhibitors. The results revealed the importance of substitutions on the medium-sized ring (carbons 8, 9, 14, and 15). In particular, the activity is collapsed by the presence of a free hydroxyl at C-8, while it increases with a carbonyl at C-14, an acetoxyl at C-9, and a free hydroxyl at C-15. The most potent compound of the series, pepluanin A, showed a very high activity for a jatrophane diterpene, outperforming cyclosporin A by a factor of at least 2 in the inhibition of Pgp-mediated daunomycin transport

Isolation of an antimicrobial compound produced by bacteria associated with reef-building corals

� 2016 Raina et al. Bacterial communities associated with healthy corals produce antimicrobial compounds that inhibit the colonization and growth of invasive microbes and potential pathogens. To date, however, bacteria-derived antimicrobial molecules have not been identified in reef-building corals. Here, we report the isolation of an antimicrobial compound produced by Pseudovibrio sp. P12, a common and abundant coral-associated bacterium. This strain was capable of metabolizing dimethylsulfoniopropionate (DMSP), a sulfur molecule produced in high concentrations by reef-building corals and playing a role in structuring their bacterial communities. Bioassay-guided fractionation coupled with nuclear magnetic resonance (NMR) and mass spectrometry (MS), identified the antimicrobial as tropodithietic acid (TDA), a sulfur-containing compound likely derived from DMSP catabolism. TDA was produced in large quantities by Pseudovibrio sp., and prevented the growth of two previously identified coral pathogens, Vibrio coralliilyticus and V. owensii, at very low concentrations (0.5 μg/mL) in agar diffusion assays. Genome sequencing of Pseudovibrio sp. P12 identified gene homologs likely involved in the metabolism of DMSP and production of TDA. These results provide additional evidence for the integral role of DMSP in structuring coral-associated bacterial communities and underline the potential of these DMSP-metabolizing microbes to contribute to coral disease prevention

CD98hc facilitates B cell proliferation and adaptive humoral immunity.

The proliferation of antigen-specific lymphocytes and resulting clonal expansion are essential for adaptive immunity. We report here that B cell-specific deletion of the heavy chain of CD98 (CD98hc) resulted in lower antibody responses due to total suppression of B cell proliferation and subsequent plasma cell formation. Deletion of CD98hc did not impair early B cell activation but did inhibit later activation of the mitogen-activated protein kinase Erk1/2 and downregulation of the cell cycle inhibitor p27. Reconstitution of CD98hc-deficient B cells with CD98hc mutants showed that the integrin-binding domain of CD98hc was required for B cell proliferation but that the amino acid-transport function of CD98hc was dispensable for this. Thus, CD98hc supports integrin-dependent rapid proliferation of B cells. We propose that the advantage of adaptive immunity favored the appearance of CD98hc in vertebrates

MMORPG gaming and hostility predict internet addiction symptoms in adolescents: an empirical multilevel longitudinal study

Internet addiction (IA) has become an increasingly researched topic. In the present study, IA symptoms in adolescents were investigated longitudinally with specific focus on the individual’s hostility, gaming use (of Massively Multiplayer Online Role Playing Games [MMORPGs]) and gaming on the classroom level (calculated using the percentage of MMORPG players within classes). The sample comprised 648 Greek adolescents who were assessed over a two-year period (aged 16-18 years). IA symptoms were assessed with the Internet Addiction Test (IAT), and hostility with the relevant subscale of the Symptom Checklist-90 (SCL-90). A three-level hierarchical linear model was used to differentiate individual and classroom-level influences on IA symptoms at age 16 years and over time. MMORPG gamers and more hostile adolescents presented more symptoms of IA. However, being a member of a classroom with a higher percentage of MMORPG gamers appeared to be a protective factor for IA. These longitudinal data emphasize the importance of contextual factors at the level of the classroom in determining differences in IA symptoms during adolescence

Problematic mobile phone use and smartphone addiction across generations: the roles of psychopathological symptoms and smartphone use

Contemporary technological advances have led to a significant increase in using mobile technologies. Recent research has pointed to potential problems as a consequence of mobile overuse, including addiction, financial problems, dangerous use (i.e. whilst driving) and prohibited use (i.e. use in forbidden areas). The aim of this study is to extend previous findings regarding the predictive power of psychopathological symptoms (depression, anxiety and stress), mobile phone use (i.e. calls, SMS, time spent on the phone, as well as the engagement in specific smartphone activities) across Generations X and Y on problematic mobile phone use in a sample of 273 adults. Findings revealed prohibited use and dependence were predicted by calls/day, time on the phone and using social media. Only for dependent mobile phone use (rather than prohibited), stress appeared as significant. Using social media and anxiety significantly predicted belonging to Generation Y, with calls per day predicted belonging to Generation X. This finding suggests Generation Y are more likely to use asynchronous social media-based communication, whereas Generation X engage more in synchronous communication. The findings have implications for prevention and awareness-raising efforts of possibly problematic mobile phone use for educators, parents and individuals, particularly including dependence and prohibited use

Quality of life, depression and fatigue in mildly disabled patients with relapsing-remitting multiple sclerosis receiving subcutaneous interferon beta-1a: 3-year results from the COGIMUS (COGnitive Impairment in MUltiple Sclerosis) study.

BACKGROUND: The precise relationships among quality of life, depression, fatigue and cognitive impairment in multiple sclerosis (MS) are complex and poorly understood. OBJECTIVE: To assess the effects of subcutaneous interferon beta-1a on quality of life, depression and fatigue over 3 years in the COGIMUS study, and to examine the relationship between these outcomes and baseline cognitive status. METHODS: COGIMUS was an observational 3-year trial assessing cognitive function in 459 patients with relapsing-remitting MS treated with subcutaneous interferon beta-1a. RESULTS: In total, 331 patients completed the study (168 received interferon beta-1a, 44 µg subcutaneously three times weekly, and 163 received interferon beta-1a, 22 µg subcutaneously three times weekly). Mean MS Quality of Life-54 (MSQoL-54) composite scores did not change over time. There were no significant differences between groups in MSQoL-54 composite scores when patients were grouped by treatment dose and baseline cognitive status. Mean (standard deviation) Hamilton Depression Rating Scale score decreased from 6.8 (4.9) at baseline to 5.8 (5.9) at year 3. Mean total Fatigue Impact Scale scores were low (<30) at all time points. CONCLUSION: Quality of life, depression and fatigue remained largely stable over 3 years; no effects of treatment dose or baseline cognitive status were found

Vasospastic Phenomena on the Luminal Replica of Rat Brain Vessels

Strikingly localized ring-like constrictions (other than sphincters, cushions and offshoot furrows) have appeared on the casted vessels of some of our preparations. Morphology of the phenomena reveals diverse degree of active contraction of the vessel wall, ranging from corrugation of the luminal surface to near severance of the acrylic cast. Distribution of the vasospastic phenomena reveals as particularly affected the arteries in the diameter range between 25 and 75 μm, that belong either to intra-arterial anastomoses between the branches of each of the three major cerebral arteries or to their terminal junctions in the border zones (inter-arterial anastomoses). Among the possible causes for the occurrence of the observed vasospasms, we indicate the susceptibility to raised intraluminal pressure during injection, producing contraction of the smooth muscle cell. Reactivity appears heightened in the anastomotic districts of the circulation. The evidence of so-called plastic strips clinging to constricted sections of affected vessels prompts re-examination of their proposed origin as plastic wrapping . Rather, they appear to be remnants of dynamic elements of the vascular wall (smooth muscle cells) that resisted corrosion