Väkivaltaisten videopelien vaikutus lapsen ja nuoren kasvuun

Tiivistelmä. Väkivaltaiset videopelit ovat yhä useamman lapsen, sekä nuoren arkea ja niiden mahdollisista vaikutuksista nuorison kasvuun käydään paljon keskustelua. Tässä tutkielmassa tutkimusmenetelmänä toimi kirjallisuuskatsaus, jossa perehdyttiin aikaisempiin tutkimuksiin väkivaltaisten videopelien vaikutusten osalta ja vastattiin tutkimuskysymykseen; minkälaisia vaikutuksia väkivaltaisilla videopeleillä on lasten ja nuorten kasvuun? Aikaisempia tutkimuksia haettiin Google Scholar, Web of Science ja Scopus -tietokannoista. Tutkielmassa käsiteltiin vain väkivaltaisia videopelejä poissulkien pelihalli- ja kolikkovideopelit, sekä niiden vaikutuksia vain lapsiin ja nuoriin. Vaikutukset aikuisiin jätettiin tutkielmasta pois. Tutkielmaan valittiin vain 2000-luvun jälkeen tuotettuja suomen- ja englanninkielisiä tutkimuksia. Lyhyellä aikavälillä väkivaltaiset videopelit nostivat lasten ja nuorten aggressiivisuuden tasoa lyhyellä aikavälillä, mutta samaa ei huomattu pitkällä aikavälillä, kun taas prososiaaliseen käytöksen näytti vaikuttavan pelimoodi missä kilpailullinen laski prososiaalisuutta ja yhteistyömoodi nosti sitä. Kohtuuttoman paljon pelaavilla ja ei-pelaajilla ilmeni enemmän mielenterveysongelmia kohtalaisesti pelaaviin verrattuna ja pelaaminen oli joillekin tapa lievittää ahdistusta. Ei ole varmaa aiheuttaako pelaaminen masennuksen oireita vai ovatko oireet syy pelaamiselle, mutta syrjäytyneet lapset ja nuoret valitsivat väkivaltaiset videopelit muita pelejä mieluummin. Kaveripiirin muodostumisen osalta huomattiin väkivaltaisilla videopeleillä olevan lähentävä tekijä. Kiusaamisen ja väkivaltaisten videopelien väliltä löydettiin yhteys kiusaajien valitessa mieluummin väkivaltaiset videopelit, mutta kiusaaminen johtui todennäköisesti muusta syystä kuin väkivaltaisten videopelien pelaamisesta, vaikkakin niiden pelaaminen näytti johtavan huonoon koulumenestykseen. Väkivaltaisen videopelisession jälkeen lapset käyttäytyivät vaarallisemmin tosielämän aseiden lähettyvillä, sekä peleistä opitut itsepuolustustavat nähtiin yhtenä syynä aseen mukana kantamiseen nuorten keskuudessa. Vaikutusten tutkimista tulee jatkaa videopelien muuttuessa yhä realistisemmiksi, sekä lasten ja nuorten huoltajien tietämystä vaikutuksista tulee parantaa, sillä perhetausta näyttäisi olevan yksi avaintekijöistä tutkailtaessa väkivaltaisten videopelien vaikutuksia

Evolution of a shear zone before, during and after melting

Partial melt in the deforming mid- or lower continental crust causes a strength decrease and drives formation of lithological heterogeneities. However, mechanisms of formation of syn-melt deformation zones and strain partitioning in partially molten rock remain poorly understood. We use field and microstructural observations to unravel the evolution of a partial melt shear zone, Seiland Igneous Province, northern Norway. The Øksfjord shear zone (ØSZ) is one of several paragneiss shear zones present within gabbros of the Seiland Igneous Province, formed by syn-intrusive deep crustal shearing during lithospheric extension related to continental rifting. Microstructures from the ØSZ show evidence for different deformation conditions. The first phase was active pre-melt and involved deformation at high subsolidus temperatures. This was followed by syn-melt deformation of the shear zone causing a relative strength increase towards the shear zone centre upon crystallization. The third phase nucleated two parallel shear zones at the edges of the ØSZ; melt textures are absent and microstructures indicate deformation at lower temperatures and higher stresses. In effect, melt migration towards the shear zone centre ultimately led to strengthening of the shear zone core, with post-crystallization deformation focusing along shear zone margins where significant heterogeneities are present

Insights into Regional Metallogeny from Detailed Compositional Studies of Alluvial Gold: An Example from the Loch Tay Area, Central Scotland

Compositional features of a total of 1887 gold alluvial particles from six localities to the south of Loch Tay in central Scotland were interpreted to establish different types of source mineralization. Populations of gold particles from each locality were grouped according to alloy and inclusion signatures. Inclusion suites provided the primary discriminant with gold from Group 1 localities showing a narrow range of simple sulphide and sulphoarsenide inclusion species, whereas a wide range of minerals including molybdenite, bornite and various Bi and Te- bearing species were identified in gold from Group 2 localities. Whilst the range of Ag in alloys in all populations was similar, higher incidences of measurable Hg and Cu were detected in Group 1 and Group 2 gold samples respectively. The application of compositional templates of gold from other localities worldwide indicated that Group 1 gold is orogenic and Group 2 gold is a mixture of porphyry and epithermal origin; a result that is sympathetic to the spatial relationships of sample localities with local lithologies. This approach both provides an enhanced level of understanding of regional gold metallogeny where in situ sources remain undiscovered, and permits clearer targeting of deposit types during future exploration

Changes in dip and frictional properties of the basal detachment controlling orogenic wedge propagation and frontal collapse: the External central Betics case

Thin-skinned fold-and-thrust belts (FTBs) have been extensively studied through both field examples and modelling. The overall dynamics of FTBs are, therefore, well understood. One less understood aspect is the combined influence of across-strike changes in the detachment properties and the basement topography on the behaviour of an orogenic wedge. In this paper, we use field data together with reflection seismic interpretation from the External Zones of the Central Betics FTB, S Spain, to identify a significant increase in the wedge basal dip (a basement "threshold") coinciding with the pinch-out of a weak substrate. This induced both changes to the wedge geometry and to the basal friction, which in turn influenced the wedge dynamics. The changing dynamics led to a transient “stagnation” of the FTB propagation, topographic build-up and subsequent collapse of the FTB front. This in turn fed an important Langhian depocenter made up of mass transport deposits. Coevally with the FTB propagation, extension took place both parallel and perpendicular to the orogenic trend. This case study illustrates how across-strike changes in wedge basal properties can control the detailed behaviour of a developing FTB front, but questions remain regarding the time-space interaction and relative importance of the basal parameters

Melt organisation and strain partitioning in the lower crust

Partial melts can form as a result of crustal thickening due to orogenesis. Even small melt fractions weaken the crust, so that partially molten volumes should accumulate significant amounts of strain. However, relatively little is known of how strain partitions in partial melts, and how effective the melt expulsion processes from the partially molten crust are. Using examples from the Western Gneiss Region (WGR), Norway, we consider a case of co-existing migmatites and shear zones. Field, image analysis, and microanalytical methods allow (semi)quantification of melt volume, rock mineralogy and mineral chemistry, and microstructures. Integration of these analyses implies effective syn-melt strain partitioning and subsequent freezing of both the shear zone and migmatite texture. We propose a mechanism that allows i) syn-melt strain localisation at an outcrop scale through stress-driven melt organisation, resulting in significant relative competence differences in a partially molten rock volume; and ii) formation of fine-grained rocks at outcrop that is entirely or mostly syn-melt, without subsequent mylonitic shearing in the solid-state. Syn-melt shear zones that have not acted as effective melt transport channels and/or that have not accumulated post-melt deformation may be more common than conventionally assumed

Relationships between basin architecture, basin closure, and occurrence of sulphide-bearing schists: an example from Tampere Schist Belt, Finland

We present field observations from the Palaeoproterozoic volcano-sedimentary Tampere palaeobasin, where the primary structures have been exceptionally well preserved. We use the observations to construct a new tectonic model for the southeastern margin of the Tampere basin during its inversion and subsequent closure. The observed volcano-sedimentary and structural features suggest a change in the local structural style from thick-skinned inversion to thin-skinned thrusting, in order to accommodate the crustal shortening during basin closure. Furthermore, it is suggested that there is a genetic relationship between the interpreted palaeothrust and the sulphide-bearing schist horizons in the study area. On a more general note, the results infer that presently subvertical mineralised shear zones may have originally been gently dipping, further suggesting that the mineralised fluids may not necessarily have been sourced from great depths (i.e. from deep within the basement)

Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions

Background: Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. Objectives: To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols. Methods: Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses. Results: The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification. Conclusions: Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a reduction of carbonaceous soot in the ship emissions by implementation of filtration devices

A geostatistical approach to analyzing gold distribution controlled by large-scale fault systems – An example from Côte d’Ivoire

Geostatistical approaches can help to understand the general characteristics of an area, to suggest feasible geological models, and to quantify overall patterns in the occurrence of economic mineralisation. We use such an approach to demonstrate the relationships between large-scale faults of various ages and kinematics, lithologies, and gold mineralisation to facilitate understanding of crustal-scale structural controls of gold deposits. Our example comes from Côte d’Ivoire, which is known to have undergone at least three major phases of deformation, two of which produced transpressional faults resulting from ESE-WNW and, later, NE/ENE-SW/WSW, compression. Using aeromagnetic and surface geological data, we interpret these faults and suggest a multiphase Riedel model for the region, taking fault reactivation into consideration. With the help of this simplified model, the spatial relationships between the faults, lithology, and 909 known gold occurrences, including 554 artisanal mining sites, are analysed within a GIS. Using geostatistical methods, gold mineralisation was found to probably be a two-stage process, with the later D2 stage potentially being the peak mineralization event. Gold occurrences are most abundant within c. 3 km of both newly formed and reactivated NE-SW faults, most importantly P1 and Y2 faults, in areas of low-intermediate fault density, and close to lithological contacts within the greenstone sequences

Brittle reactivation of ductile precursor structures: The role of incomplete structural transposition at a nuclear waste disposal site, Olkiluoto, Finland

Reactivation of discrete deformation zones that are orientated favourably with respect to the stress field is a well-known phenomenon. What is less clear is the role of other structural features and heterogeneities in localizing deformation. In this paper we describe how brittle deformation structures are localized into zones of incomplete structural transposition inherited from earlier ductile deformation phases. In our example, these zones of incomplete structural transposition are characterised by localised high-strain structures of the latest ductile deformation stage, including short limbs of strongly asymmetric folds and anastomosing networks of minor shear fabrics. When such zones are systematically organized, and orientated favourable with respect to the stress field, they can be very efficient in localizing deformation and forming new fault zones. Applied to the site of the planned geological repository of nuclear waste in Olkiluoto, Finland, the recognized structural inheritance provides tools to understand the geometries, networks and kinematics of the brittle fault zones and the related secondary fracturing which together define the rock mechanical and hydrogeological framework for the repository

Timing of syn-orogenic, high-grade transtensional shear zone formation in the West Uusimaa Complex, Finland

We present zircon and titanite U-Pb ages from granulite-facies transtensional shear zones and a greenschist facies strike-slip shear zone in the Karkkila-Vihti area, West Uusimaa. The zircon rim and titanite ages of c. 1815−1820 Ma from the transtensional shear zones constrain the evolution of the orogenic deformation from compression-dominated to syn-compressional lateral-escape within this part of the Fennoscandian shield while the zircon rim and titanite ages of 1790−1800 Ma give the timing of the late- to post-orogenic low-grade reactivation of the large-scale Somero-Karkkila fault zone. The new age data further constrain the timing of the changes in the crustal deformation style during orogenesis from i) compression-dominated to combined transpression - lateral stretching and escape, to ii) the late- to post-orogenic transition into retrograde conditions