401 research outputs found
Two Social Worlds: Social Correlates and Stability of Adolescent Status Groups
Examined adolescents\u27 peer group status in high school using self-report, peer nominations, and archival data collected during 2 consecutive school yrs. 408 students participated in the 1st yr, and 404 students participated in the 2nd yr. 60% of the 2nd yr Ss had also participated in the 1st yr. Higher status students (popular and controversial) had more close friends, engaged more frequently in peer activities, and self-disclosed more than lower status students (rejected and neglected). They were also more involved in extracurricular school activities and received more social honors from their schoolmates. Although the higher status students were more alike than different, controversial adolescents did report more self-disclosure and dating behavior than popular students. Lower status students were also highly similar, although rejected students reported lower grades
Revising the Body Esteem Scale with a U.S. College Student Sample: Evaluation, Validation, and Uses for the BES-R
The Body Esteem Scale (BES; Franzoi and Shields 1984) has been a primary research tool for over 30 years, yet its factor structure has not been fully assessed since its creation, so a two-study design examined whether the BES needed revision. In Study 1, a series of principal components analyses (PCAs) was conducted using the BES responses of 798 undergraduate students, with results indicating that changes were necessary to improve the scale’s accuracy. In Study 2, 1237 undergraduate students evaluated each BES item, along with a select set of new body items, while also rating each item’s importance to their own body esteem. Body items meeting minimum importance criteria were then utilized in a series of PCAs to develop a revised scale that has strong internal consistency and good convergent and discriminant validity. As with the original BES, the revised BES (BES-R) conceives of body esteem as both gender-specific and multidimensional. Given that the accurate assessment of body esteem is essential in better understanding the link between this construct and mental health, the BES-R can now be used in research to illuminate this link, as well as in prevention and treatment programs for body-image issues. Further implications are discussed
Can the effects of anthropogenic pressures and environmental variability on nekton fauna be detected in fishery data? Insights from the monitoring of the artisanal fishery within the Venice lagoon
Nekton communities in transitional ecosystems are naturally adapted to stressful conditions associated with high environmental variability. Human activities in these systems are likely to determine additional stress with a possible effect on fish fauna, hence on fisheries. In order to test the relative importance of natural and anthropogenic factors in determining changes in nekton community, catches (incl. bycatch) from artisanal fisheries (fyke nets) were monitored seasonally in different areas of the Venice lagoon (Italy) between 2001 and 2013. Changes in nekton community composition and in the biomass of target and non-target species/groups were analysed, and the results were related to temporal factors, environmental characteristics and to the variability in anthropogenic pressures. Statistical tests were carried out using a model-based analysis of both univariate and multivariate data. Results highlighted that temporal factors and environmental conditions (i.e. the main chemico-physical descriptors) are more relevant than anthropogenic pressures in explaining spatial and temporal changes in the lagoon nekton assemblage, but that several characteristics of the assemblage, in particular the biomass of some particular categories and of the whole assemblage, are sensitive to human impacts. A particularly negligible effect seemed to be associated with fishing effort, thus suggesting that the monitoring of the local artisanal fishery is suitable also to provide useful information on the evaluation of the status of nekton assemblage
Linking food web functioning and habitat diversity for an ecosystem based management: A Mediterranean lagoon case-study
We propose a modelling approach relating the functioning of a transitional ecosystem with the spatial extension of its habitats. A test case is presented for the lagoon of Venice, discussing the results in the context of the application of current EU directives. The effects on food web functioning due to changes related to manageable and unmanageable drivers were investigated. The modelling procedure involved the use of steady-state food web models and network analysis, respectively applied to estimate the fluxes of energy associated with trophic interactions, and to compute indices of food web functioning. On the long term (hundred years) temporal scale, the model indicated that the expected loss of salt marshes will produce further changes at the system level, with a lagoon showing a decrease in the energy processing efficiency. On the short term scale, simulation results indicated that fishery management accompanied by seagrass restoration measures would produce a slight transition towards a more healthy system, with higher energy cycling, and maintaining a good balance between processing efficiency and resilience. Scenarios presented suggest that the effectiveness of short term management strategies can be better evaluated when contextualized in the long term trends of evolution of a system. We also remark the need for further studying the relationship between habitat diversity and indicators of food web functioning
Multidimensional natal isotopic niches refect migratory patterns in birds
7openInternationalBothNaturally occurring stable isotope ratios in animal tissues allow estimation of species trophic position and ecological niche. Measuring multiple isotopes of migratory species along flyway bottlenecks offers the opportunity to sample multiple populations and species whose tissues carry information at continental scales. We measured δ2H, δ18O, δ13C, δ15N in juvenile feathers of 21 bird species captured at a migratory bottleneck in the Italian Alps. We examined if trends in individual isotopes reflected known migratory strategies and whether dietary (δ13C–δ15N) and spatially-explicit breeding origin (δ2H–δ18O) niche breadth (NB) differed among long-distance trans-Saharan (TS), short-distance (IP) and irruptive (IR) intra-Palearctic migrants, and whether they correlated with reported populations long-term trends. In both TS and IP groups, species δ2H declined with capture date, indicating that northern populations reached the stopover site later in the season, following a Type-I migration strategy. Values of δ2H indicated that breeding range of TS migrants extended farther north than IP and IR migrants. The breeding season was longer for IP migrants whose δ13C and δ15N values declined and increased, respectively, with time of capture. Average species dietary NB did not differ among migratory groups, but TS migrants displayed wider breeding origin niches, suggesting that long-distant migration is linked to broader ecological niches. Isotope origin NB well reflected species geographic range extent, while dietary NB did not correlate with literature accounts of species’ diet. We found no relationship between species breeding NB and population trends in Europe, suggesting that conditions in the breeding grounds, as inferred by stable isotopes, are not the only determinant of species’ long-term persistence. We demonstrate that ringing activities and isotopic measurements of passerines migrating through a bottleneck represents a unique opportunity to investigate large-scale life-history phenomena relevant to conservation.openFranzoi, A.; Larsen, S.; Franceschi, P.; Hobson, K. A.; Pedrini, P.; Camin, F.; Bontempo, L.Franzoi, A.; Larsen, S.; Franceschi, P.; Hobson, K.A.; Pedrini, P.; Camin, F.; Bontempo, L
Design, synthesis and application of luminescent rhenium complexes in cell imaging
This thesis describes the development of a new variety of lumophores, in particular luminescent rhenium(I) complexes of the type Re(bisim)(CO)3L n+, where bisim represents a bisimine derivative, e.g. bipyridine, and Lisa pyridine derivative (n = 1) or a chloride (n = 0), suitable for specific cell imaging and whose modified photophysical properties overcome some of the problems associated with traditional imaging agents (small Stokes shift, short lifetimes, etc). Specifically the successful synthesis and photophysical studies of a chemical model to validate the concept of a membrane permeable cell-imaging device, fac-Re0)ipyXCO)3(PyCH2COO(CH2)3OTBD) +, are presented. Further investigations towards and improved cell imaging agent, considering different issues like water solubility, lipophilicity and cell encapsulation rate, are then undertaken. Consequently, a new range of water soluble rhenium complexes, ykc- Re(bisimXCO)3(L) n" where bisim is a water soluble bathophenanthroline and L is a pyridine derivative (n = 2) or a chloride (n = 1), as well as a variety of novel yac-Re(bisimXCO)3Cl complexes, where bisim is a terpyridine derivative bearing a self destruction device which can be triggered by nitroreductase, are also presented. Additionally, the synthesis and structural description of a trinuclear rhenium complex is reported, along with a discussion of its use in inclusion experiments and attempts at analogue formation. The design and synthesis of a thiol selective luminescent rhenium complex, fac-Re(bipyXCO)3(PyCH2Cl) +, is described, along with the demonstration of its thiol selectivity both in vitro and in vivo as demonstrated by specific mitochondrial localization. Finally, studies of membrane permeability in liposome models, cellular uptake and localization in different cells such as Spironucleous vortens, yeast cells and human breast cancer cells of a variety of rhenium complexes above cited are also reported. These results combine to demonstrate the promising future of this new class of imaging probes as specific cell imaging agents and therefore, this work represents the initial step in the growing area of the development of transition metal based imaging agents.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Examining the association between depression and seizures amongst adults with epilepsy : a longitudinal analysis
This programme of work examined the links between psychopathology and seizures for adults with epilepsy using longitudinal data from two datasets and employing state-of the-art analytic approaches to tease apart inter-relationships. In the first study, using path analysis to examine direction of effects, a bi-directional relationship between seizure frequency and depression scores was confirmed. That is, not only did seizure frequency influence depression scores longitudinally and concurrently, but that depression scores also influenced seizure frequency equivalently. The second study employed a latent variable structural equation modelling approach to examine moderation and mediation and prediction of change in variable scores over time. In this study although anxiety, perceived stress and depression all separately influenced changes in seizures (frequency and recency), depression mediated the relationship between both anxiety and stress with seizures. The third study used a latent growth curve approach to focus on patterns of change within individuals. Trajectories of change in depression scores for individuals over time were examined as well as factors predicting this variation. This study found that seizure recency was a significant predictor of the individual differences in baseline depression scores as well as of the changes in depression scores over time for individuals with epilepsy. The implications of these results are that both effective management of seizures and depression are essential for people with epilepsy. Given that the current focus of clinical management strategies for people with epilepsy is on seizure management, this research suggests the importance of also identifying and managing depression amongst people with epilepsy. Strategies to implement this would include increased awareness of the importance of depression amongst clinical staff, improved screening for depression amongst people with epilepsy (for example by using depression screening questionnaires such as the Hospital Anxiety and Depression Scale), implementing effective treatment (such as by using antidepressants or cognitive behaviour therapy) if depression is identified. Future aims would include confirming these findings using alternative designs, for example a randomised trial to investigate whether these links between depression and seizures arise because of a common antecedent factor or shared risk factors and examine whether other factors (such as gender) influence the relationships observed between depression and seizure outcomes.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Progress towards the total synthesis of N-methylwelwitindolinone C isothiocyanate
This thesis focuses on our progress towards the total synthesis of N-methylwelwitindolinone C isothiocyanate 7, commonly called welwistatin. This major alkaloid of the welwitindolinone family, which was isolated from Hapalosiphon welwitschii in 1994, represents a particularly attractive target due to its interesting biological activities (MDR reversing agent) and its challenging structure. Welwistatin possesses a complex bicyclo[4.3.1]decane ring system consisting of four stereogenic centres, three quaternary carbons and two unusual reactive functionalities: the isothiocyanate bridgehead and a vinyl chloride group. Inspired by the synthetic challenge of this complex architecture, the Simpkins group reported an expedient four-step synthesis of its core structure in 2005. Three years later, our group had investigated the reactivity at the bridgehead enolate positions. Taking inspiration from this previous work, we successfully synthesised bridgehead alkene 126. The other features present on welwistatin 7 were then investigated and enone 198 was obtained. Facing some difficulties on the model system 88, we turned our attention towards the synthesis of tetracycle 170, possessing the gem-dimethyl at the position C, and its subsequent functionalisation.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Which individual, social, and urban factors in early childhood predict psychopathology in later childhood, adolescence and young adulthood? A systematic review
Background: A comprehensive picture is lacking of the impact of early childhood (age 0–5) risk factors on the subsequent development of mental health symptoms. Objective: In this systematic review, we investigated which individual, social and urban factors, experienced in early childhood, contribute to the development of lateranxiety and depression, behavioural problems, and internalising and externalising symptoms in youth. Methods: Embase, MEDLINE, Scopus, and PsycInfo were searched on the 5th of January 2022. Three additional databases were retrieved from a mega-systematic review source that focused on the identification of both risk and protective indicators for the onset and maintenance of prospective depressive, anxiety and substance use disorders. A total of 46,450 records were identified and screened in ASReview, an AI-aided systematic review tool. We included studies with experimental, quasi-experimental, prospective and longitudinal study designs, while studies that focused on biological and genetical factors, were excluded. Results: Twenty studies were included. The majority of studies explored individual-level risk factors (N = 16). Eleven studies also explored social risk factors and three studied urban risk factors. We found evidence for early predictors relating to later psychopathology measures (i.e., anxiety and depression, behavioural problems, and internalising and externalising symptoms) in childhood, adolescence and early adulthood. These were: parental psychopathology, exposure to parental physical and verbal violence and social and neighbourhood disadvantage. Conclusions: Very young children are exposed to a complex mix of risk factors, which operate at different levels and influence children at different time points. The urban environment appears to have an effect on psychopathology but it is understudied compared to individual-level factors. Moreover, we need more research exploring the interaction between individual, social and urban factor
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