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  • 1
    Publikationsdatum: 2019
    Beschreibung: The aim of the present study was to analyze the relationship between family communication problems and cyberbullying, through psychosocial adjustment—psychological distress, attitude towards institutional authority, and problematic use of social networking sites—in adolescents. Random sampling by conglomerates was performed. A total of 8115 adolescents participated in the study (51.5% boys, 49.5% girls), and were aged between 11 and 16 years old (M = 13.34, SD = 1.04) and enrolled in the State of Nuevo León (Mexico). A structural equations model was developed using the Structural Equation Modeling Software (EQS). The results showed that problematic family communication is directly associated with cyberbullying, and also indirectly through the relationships of psychological distress and attitude towards transgression of social norms with the problematic use of social networking sites. The multi-group analyses also revealed gender differences in these relationships. Finally, the obtained results were discussed and their practical implications were shown.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 2019
    Beschreibung: The objective of the present study is to analyse the relationships between parental socialization styles—indulgent, authoritarian, authoritative and negligent, school adjustment (social integration, academic competence and family involvement) and cyber-aggression (direct and indirect) in adolescents. Participating in this study were 1304 Spanish students of both sexes (53.1% girls), aged between 12 and 18 years (M = 13.87, SD = 1.33). Multivariate analyses of variance were performed. The results showed significant relationships between parental socialization styles, school adjustment and cyber-aggression. It was observed that adolescents from indulgent and authoritative families showed greater academic competence and greater family involvement. Additionally, the children from authoritarian families displayed greater involvement in direct and indirect cyber-aggression behaviours. The results obtained and their implications are discussed in the final section.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 2019
    Beschreibung: Abstract Contractional deformation in the outer parts of fold‐and‐thrust belts is in part controlled by the presence of syntectonic sediments and multiple décollements (e.g. the Apennines, the Appalachians, the Pyrenees, the Zagros, or the Sub‐Andean and Kuqa fold‐and‐thrust belts). To better understand the influence of these parameters in the kinematic evolution of fold‐and‐thrust systems, we carried out an experimental study including four 3D sandbox models inspired by one of the previously mentioned prototypes, the Kuqa fold‐and‐thrust belt. This belt contains two décollements: a weak synorogenic salt layer; and a deeper, preorogenic and frictionless décollement (i.e., organic‐rich shales) showing along strike variations of rheology. The experimental results show that increasing synkinematic sedimentation rate: (i) generates a progressive change from distributed to localized deformation and, (ii) delays the development of frontal contractional structures detached on the salt, favoring the formation and reactivation of more hinterland thrusts and backthrusts. With respect to the rheology, our study reveals that as the viscosity of the prekinematic décollement increases: (i) the deformation propagates more slowly towards the foreland and, (ii) the underlying thrust stack becomes broader and lower and has a gentler thrust taper angle. The rheology of the prekinematic décollement defines the distribution and geometry of the structures detached on it that in turn influence the development of overlying, salt‐detached structures. Subsalt structures can: (i) determine the areal extent of the salt and therefore of any fold‐and‐thrust system detached on it and, (ii) hamper or even prevent the progressive foreland propagation of deformation above the salt.
    Print ISSN: 0278-7407
    Digitale ISSN: 1944-9194
    Thema: Geologie und Paläontologie
    Publiziert von Wiley im Namen von American Geophysical Union (AGU).
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 2019
    Beschreibung: This study examined the relations between problematic cannabis use, physical assault, and getting involved in a motor vehicle accident under the influence of cannabis in a sample of adolescents randomly selected from 25 public and semiprivate high schools in Alicante (Spain). Participants (n = 648) completed The Spanish National Standardized Survey about drug use in high school adolescents (ESTUDES, 2017), which includes the cannabis abuse screening test (CAST). Prevalence of cannabis use across the life-span and within the past 30 days was 37.5% and 17.4%, respectively. CAST scores were associated with an increased risk of driving under the effects of cannabis, riding shotgun, and physical assault, but not with an increased risk of having a motor vehicle accident. There were no differences between boys and girls in the association of problematic cannabis use with risky behaviors. This result highlights the importance of comprehensive prevention and education strategies for adolescents at high risk of cannabis use.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Publikationsdatum: 2019
    Beschreibung: Research on current practices and the state of green public procurement enables the identification of areas that can be improved, as well as opportunities to improve the tendering procedures from an environmental point of view. To understand the behaviour of local, provincial, and regional administrations concerning green public procurement, a case study on the Valencia region of Spain is made. The Valencian region is one of the most important communities in terms of population, number of contracting authorities, and weight in the Spanish Gross Domestic Product. In this study, a total of 967 procedures were analysed from calls for tenders made by municipal, provincial, and regional administrations in2016 and 2017.The results of this study show that the use of environmental criteria is 19.7% and the average weight is 4.1 out of 100. The civil engineering subsector, more than the building subsector, employs environmental criteria, particularly in projects tendered by regional administrations, whereas for projects with large budgets the level of use is similar for both subsectors. It is necessary to encourage plans to improve Green Public Procurement (GPP) practices in the Valencian administrations, especially those with a local scope such as municipalities.
    Print ISSN: 1661-7827
    Digitale ISSN: 1660-4601
    Thema: Energietechnik , Medizin
    Publiziert von MDPI
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 2016
    Beschreibung: Abstract The scombrids (Family Scombridae), commonly known as tunas, bonitos, Spanish mackerels, and mackerels, play an important role as predators and prey in coastal and oceanic marine ecosystems, and sustain some of the most important fisheries in the world. Knowledge of their basic biology and life history traits, such as growth, age and maturity, is fundamental to sustainably manage these species, and maintain their critical role in marine ecosystems. Given the economic and social importance of their fisheries in many regions throughout the world, numerous life history studies have been conducted in the last century. Despite efforts to create global repositories of life history parameters, e.g. FishBase, many life history studies remain scattered and not readily accessible. Here, we compiled 667 life history studies published between 1933 and 2012 describing the growth, age, and reproductive biology of the 51 species of scombrids distributed around the world and create a standardized life history dataset including maximum size, longevity, growth, maturity, fecundity, spawning season and frequency, and egg size information. We created this dataset to promote the best use of the existing life history information and with the intention of providing a data resource suitable to test large‐scale ecological hypotheses on life history strategies and life history evolution, as well as support the management and conservation of this important group of commercially exploited species. We envisage the large repository of standardized life history data compiled will make this endeavor more effective and robust by providing a valuable resource that can help address many research questions. This article is protected by copyright. All rights reserved.
    Print ISSN: 0012-9658
    Digitale ISSN: 1939-9170
    Thema: Biologie
    Publiziert von Wiley im Namen von The Ecological Society of America (ESA).
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 2019
    Beschreibung: This paper aims to evaluate the spatial persistence of wild oat patches in four wheat fields over time to determine the economic feasibility of using late-season wild oat maps for early site-specific weed management (SSWM) next season. The spatial persistence of wild oat patches was analyzed by three tests: land use change detection between years, spatial autocorrelation, and analysis of spreading distance. The temporal trend of wild oat patch distribution showed a clear persistence and a generalized increase in the infested area, with a noticeable level of weed aggregation and a tendency in the new weed patches to emerge close to older ones. To economically evaluate the SSWM, five simulations in four agronomic scenarios, varying wheat yields and losses due to wild oat, were conducted. When yield losses due to wild oat were minimal and for any of the expected wheat yields, some SSWM simulations were more economically profitable than the overall application in most of the fields. Nevertheless, when the yield losses due to wild oat were maximal, all SSWM simulations were less profitable than overall treatment in all the analyzed fields. Although the economic profit variations achieved with SSWM treatments were modest, any of the site-specific treatments tested are preferred to herbicide broadcast over the entire field, in order to reduce herbicide and environmental pollution.
    Digitale ISSN: 2073-4395
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Wirtschaftswissenschaften
    Publiziert von MDPI
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    Publikationsdatum: 2019
    Beschreibung: Abstract The study of the coastal landscapes of hotspot oceanic islands through comprehensive structural metrics and ecological estimators represents an opportunity to explore geomorphological transformations and broad spatiotemporal scale features of coastal evolution. As part of this approach, a new metrical comparative analysis is presented in this study, comprising four islands in different evolutionary stages. They belong to the Cape Verde archipelago, which forms a double insular chain in which an east‐west gradient in age and evolution is particularly evident across the southern chain. A space‐for‐time (SFT) substitution approach is applied to the coasts of (1) Fogo, in the shield stage; (2) Santiago, in the early post‐erosional stage; (3) São Vicente, in the advanced post‐erosional stage; and (4) Boa Vista, in the last erosional stage. From the obtained spatial distributions and frequencies of landforms, the coastal landscapes of these islands are compared in relation to their (i) geomorphic composition, using similarity indices (Whittaker, βw, Sorensen, Cs) and nestedness estimators (NOFD, WNODF), (ii) geomorphic abundance, using morpho‐assembling densities (Dgm), and (iii) geomorphic diversity, using six alpha‐diversity indices (Richness, S, Menhinick, DMN, Simpson, D, Shannon, H', Berger‐Parker, d, and Brillouin, HB). An advanced geomorphological taxonomy is implemented for areas with limited open‐access data, including a set of planform features captured through scale‐frequency decomposition. Photographic, cartographic and field work data are used for landform identification at 1,200 random sampling points, empirically determined by a bootstrap method. The results show a chronological ordering of the compared variables and a possible co‐evolution towards an increase in organizational geomorphic complexity of coastal systems at broad space‐time scales. The method proposed in this study can contribute, from a metrical perspective, to finding new long‐term evolutionary features and constitutes an advance in the development of an integrated model of coastal evolution in oceanic islands.
    Print ISSN: 0360-1269
    Digitale ISSN: 1096-9837
    Thema: Geographie , Geologie und Paläontologie
    Publiziert von Wiley
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    Publikationsdatum: 2019
    Beschreibung: This paper presents an object-based approach to mapping a set of landforms located in the fluvio-eolian plain of Rio Dulce and alluvial plain of Rio Salado (Dry Chaco, Argentina), with two Landsat 8 images collected in summer and winter combined with topographic data. The research was conducted in two stages. The first stage focused on basic-spectral landform classifications where both pixel- and object-based image analyses were tested with five classification algorithms: Mahalanobis Distance (MD), Spectral Angle Mapper (SAM), Maximum Likelihood (ML), Support Vector Machine (SVM) and Decision Tree (DT). The results obtained indicate that object-based analyses clearly outperform pixel-based classifications, with an increase in accuracy of up to 35%. The second stage focused on advanced object-based derived variables with topographic ancillary data classifications. The combinations of variables were tested in order to obtain the most accurate map of landforms based on the most successful classifiers identified in the previous stage (ML, SVM and DT). The results indicate that DT is the most accurate classifier, exhibiting the highest overall accuracies with values greater than 72% in both the winter and summer images. Future work could combine both, the most appropriate methodologies and combinations of variables obtained in this study, with physico-chemical variables sampled to improve the classification of landforms and even of types of soil.
    Digitale ISSN: 2220-9964
    Thema: Architektur, Bauingenieurwesen, Vermessung , Geologie und Paläontologie
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 2015-10-22
    Beschreibung: Gravel-bed rivers commonly exhibit a coarse surface armor resulting from a complex history of interactions between flow and sediment supply. The evolution of the surface texture under single storm events or under steady flow conditions has been studied by a number of researchers. However, the role of successive floods on the surface texture evolution is still poorly understood. An experimental campaign in an 18 m-long 1 m-wide flume has been designed to study these issues. Eight consecutive runs, each one consisting of a low-flow period of variable duration followed by a sudden flood (water pulse) lasting 1.5 h, have been conducted. The total duration of the experiment was 46 h. The initial bed surface was created during a 280 h-long experiment focused on the influence of episodic sediment supply on channel adjustments. Our experiments represent a realistic armored and structured beds found in mountain gravel-bed rivers. The armor surface texture persists over the duration of the experiment. The experiment exhibits downstream fining of the bed surface texture. It was found that sorting processes were affected by the duration of low-flow between flood pulses. Since bedload transport is influenced by sediment sorting, the evolution of bedload transport is impacted by the frequency of the water pulses: short inter-pulse durations reduce the time over which fine material (transported as bedload) can be winnowed. This, in turn, contributes to declining reduction of the bedload transport over time while the sediment storage increases. This article is protected by copyright. All rights reserved.
    Print ISSN: 0043-1397
    Digitale ISSN: 1944-7973
    Thema: Architektur, Bauingenieurwesen, Vermessung , Geographie
    Publiziert von Wiley im Namen von American Geophysical Union (AGU).
    Standort Signatur Erwartet Verfügbarkeit
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