Kakva je naša onlajn interakcija? Jedan pristup za proučavanje multidimenzionalnosti onlajn komunikacije

If different dimensions of online interaction are neglected and/or unknowingly combined in a research study there is a risk of misleading results due to compensatory effect. With respect to the multidimensionality of online interaction, two substantially different types of online communication are defined - procreative and transmissional. The procreative online communication is understood as a person's tendency to use the internet as a space for social interaction, which essentially differs from using the internet transmissionally, as a peer-to-peer communication channel between people who are familiar with one another. The aim of this paper is to explore more deeply the procreative dimensions of online communication. Based on our conceptual framework, we defined three procreativity dimensions and developed an Online Procreativity Scale (OPS) to measure them. The OPS has been validated through EFA and CFA and the three-dimensional structure has been confirmed. Using the OLS regression analyses we found that gender and psychological characteristics and social network sites (SNS) use have diverse influence depending on the procreativity dimension under observation. Gender, city size, share of unfamiliar SNS friends and loneliness predicted willingness to interact with strangers, while the time spent on SNS predicted only the tendency to participate in public online interaction.Ukoliko se ne vodi računa o različitim dimenzijama onlajn interakcije lako se može desiti da zbog njihovog međusobnog preklapanja i maskiranja dođemo do sasvim pogrešnih istraživačkih nalaza. U skladu sa razumevanjem onlajn interakcije kao multidimenzionalnog procesa izdvojili smo dva suštinski različita tipa on-lajn komunikacije - prokreativni i transmisioni. Onlajn komunikaciju prokreativnog tipa razumemo kao tendenciju pojedinca ka upotrebi interneta kao prostora za društvenu interakciju nasuprot suštinski različitog transmisionog tipa onlajn interakcije koja se zasniva na kanalskoj, jedan na jedan komunikaciji, međusobno poznatih subjekata. Cilj ovog rada je da se bolje istraže različite dimenzije on-lajn prokreativnosti. Na osnovu našeg teorijskog polazišta identifikovali smo tri dimenzije prokreativnosti i razvili skalu onlajn prokreativnosti (OPS-Online Pro-creativity Scale) za njihovo merenje. Validnost OPS je verifikovana posredstvom EFA i CFA čime je potvrđena trodimenzionalna struktura skale. Koristeći OLS regresionu analizu utvrdili smo da pol, psihološke karakteristike i upotreba platformi za društveno umrežavanje, imaju različit uticaj na tri dimenzije prokreativnosti. Utvrdili smo da su pol, veličina mesta boravka, udeo nepoznatih ljudi među prijateljima na onlajn mrežama i usamljenost prediktori spremnosti da se uđe u interakciju sa nepoznatim ljudima na internetu, dok je vreme koje se provodi na onlajn mrežama jedino bilo prediktor tendencije da se učestvuje u javnoj onlajn interakciji

Izloženost krizotil azbestu u okolišu i epidemiologija raka

A total of 1931 persons from the general population living around a chrysotile asbestos mine and mill were selected for the study as an exposed group. The control group consisted of 1250 persons from a village without asbestos fibre content in the ambient air. The exposed population decreased by 22% from the 1961 to the 1981 census and liveborn children were three times fewer. X-ray data show a high percentage of pleural involvement, suspect findings of the “Z” and “PL” categories with the prevalence of chronic bronchitis among the exposed, reaching a level of P < 0.01. The incidence of malignant tumours was statistically significantly greater in the exposed than in the control group (K= 1, P<0.01, χ2-8.538).Studijom je obuhvaćena 1931 osoba opće populacije što živi u okolici azbestnih rudnika i mlinova. Kontrolna skupina sastojala se od 1250 osoba koje nisu izložene azbestu u okolišu. Izložena populacija smanjila se 22% u razdoblju od 1961. do 1981. godine budući da je bilo tri puta manje živorođene djece negoli u kontrolnoj skupini. Rendgernske snimke pokazuju visok postotak pleuralnih promjena, suspektnih nalaza „Z“ i „PL“ kategorije s prevalencijom kroničnog bronhitisa koji doseže razinu statističke značajnosti od P < 0,01. Nađeno je da je incidencija malignih tumora statistički značajno veća u izloženih stanovnika negoli u kontrolnoj skupini (K= 1, P<0,01, χ2=8,538)

Epidemiološki značaj određivanja olova, kadmija, bakra i cinka u kosi i trajnim zubima osoba koje žive u blizini topionice olova

In this paper the content of lead, cadmium, copper and zinc was analysed by atomic absorption spectrophotometry (model Unicam SP 90), in the hair of 200 persons residing in the immediate vicinity (within a distance of 5 km) of a lead smeltery and in a control group of 200 persons living at a distance greater than 10 km from the main air pollution source. Statistically significant differences in the content of the metals were found, the probability range being 0.05-0.01. The concentration of lead, cadmium, copper and zinc in permanent teeth was also analysed in relation to the distance of the residence from the lead smeltery in a group of 111 persons living 1-5 km from it and in 23 persons living in the area 20 to 30 km away. The established differences were statistically significant for all analysed metals with the exception of zinc.Autori iznose rezultate merenja sadržaja olova, kadmija, bakra i cinka u 200 uzoraka kose muškaraca i žena koji žive u blizini topionice olova i u uzorcima kose jednakog broja kontrolnih osoba koje žive daleko od topionice olova. Olovo, kadmij, bakar i cink određivani su atomskom apsorpcijskom spektrofotometrijom. Nađene su značajne razlike u koncentraciji ispitivanih metala između eksponirane i kontrolne skupine (p<0,05 i p<0,01). Koncentracije olova, kadmija, bakra i cinka merene su i u trajnim zubima 111 osoba koje žive u blizini topionice kao i u zubima 23 kontrolne osobe koje žive daleko od topionice. I u ovim su uzorcima utvrđene statistički značajne razlike u koncentracijama svih metala osim cinka između dviju ispitivanih grupa

Political informing through social media across Europe - factors and effects

Social media play a significant role in political informing across Europe and the rest of the world. That is why the political consequences of social media use have become one of the prominent issues in contemporary social research. In line with that, this paper investigates how the use of social media for political informing is associated with the state of democracy in European countries and how individual satisfaction with the level of democracy and the political activism of citizens are affected by social media use. We have used data from the latest European Value Survey, conducted in 2017-2018. Our data sample included 30 countries with the referent number of more than 56000 respondents involved in the survey. The main finding of our research is that a deficit of democracy leads people to use social media as a part of their political informing repertoires. This finding applies to both, those who live in undemocratic circumstances and those who live in developed democracies but have a negative personal perception of democratic procedures in their country. It seems that once citizens are "forced" to use social media for political informing, they, in turn, become influenced by media content displayed there and by other peoples' ideas. In other words, the very use of social media makes them even more critical of democracy and consequently more politically active, which brings them back to social media

Cross sections and transport properties of negative ions in rare gases

We have used a combination of a simple semi-analytic theory - Momentum Transfer Theory (MTT) and exact Monte Carlo (MC) simulations to develop momentum transfer cross sections of negative ions in collisions with noble gases based on the available data for reduced mobility at 300K as a function of E/N. At very low energies, we extrapolated obtained cross sections using Langevin's cross section and supplemented it by the total detachment cross section that was used from the threshold around 6 eV up to 100 eV. Other possible reactive processes have not been taken into account. A good agreement for the mean energy and diffusion coefficients is an independent proof of the validity of the cross sections that were derived for the negative ion mobility data

Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes

Axial emission profiles in a parallel plate dc micro discharge (feedgas: argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A) characteristics were recorded and Ar* metastable densities were measured by tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in the steady state regime are similar to corresponding profiles in standard size discharges (d=1cm, p=1Torr). For some discharge conditions relaxation oscillations are present when the micro discharge switches periodically between low current Townsend-like mode and normal glow. At the same time the axial emission profile shows transient behavior, starting with peak distribution at the anode, which gradually moves towards the cathode during the normal glow. The development of argon metastable densities highly correlates with the oscillating discharge current. Gas temperatures in the low current Townsend-like mode (T= 320-400K) and the high current glow mode (T=469-526K) were determined by the broadening of the recorded spectral profiles as a function of the discharge current.Comment: submitted to Plasma Sources Sci. Techno

Morphological and biochemical changes in the prefrontal cortex, amygdala and hippocampus of the rat brain conditioned by single prolonged stress

Posttraumatski stresni poremećaj (PTSP) je veoma rasprostranjeno i onesposobljavajuće oboljenje. Uprkos raspoloživoj psihofarmakološkoj i na dokazima zasnovanoj kognitivno-bihejvioralnoj terapiji, kod značajnog broja PTSP pacijenata nema odgovora na konvencionalnu terapiju, što pokazuje da su patogenetski mehanizmi u PTSP-u još uvek nedovoljno ispitani. Pojedinačni produženi stres (PPS) predstavlja koristan animalni model PTSP-a za razumevanje patofiziologije oboljenja i razvoj novih terapijskih strategija. Preovlađujući neuroanatomski model PTSP-a, naglašava centralni značaj amigdale kao i njene interakcije sa medijalnim prefrontalnim korteksom i hipokampusom. Mnoge studije pokazuju da su neuropatološke i psihološke alteracije kod PTSD pacijenata povezane sa oksidativnim stresom u mozgu. Glavni izvori slobodnih radikala u ćeliji su mitohondrijalni respiratorni lanac i sistem nikotinin adenin dinukleotid fosfat (NADPH) fosfataze. Ekscitatorno/inhibitorni disbalans zbog disfunkcionalne GABA-ergičke neuronske mreže, ima patofiziološki značaj u mnogim psihijatrijskim oboljenjima. Parvalbumin inhibitorni interneuroni su veoma značajni za održavanje odgovarajuće ekscitatorno/inhibitorne ravnoteže i u sinhronizaciji visokofrekventnog neuronskog pražnjenja i mogu biti uključeni u patološko učenje straha u PTSP-u. Takođe, mnoge studije su pokazale učešće različitih neuropeptida u procesiranju stresnih stimulusa i stresnom odgovoru. Cilj: Cilj ove disertacije se sastojao u ispitivanju uticaja pojedinačnog produženog stresa na: (1) parametre oksidativnog stresa uključujući nivo malondialdehida (MDA), sadržaj redukovanog glutationa (GSH), aktivnost glutation peroksidaze (GPx), superoksid dizmutaze (SOD) i katalaze (CAT), i ekspresiju SOD1 i SOD2; (2) moguće generatore slobodnih radikala: mitohondrijalni respiratorni lanac, određivanjem aktivnosti kompleksa I i citohrom c oksidaze (COX) i NADPH oksidazu, određivanjem ekspresije membranskih (gp91phox i p22phox) i citosolnih (p67phox) subjedinica ovog enzima i (3) ukupan broj neurona (NeuN pozitivne ćelije), broj parvalbumin (PV) i kalbindin (CB) pozitivnih GABA-ergičkih neurona i broj supstanca P (SP), enkefalin (ENK) i galanin (GAL) pozitivnih peptidergičkih neurona u prefrontalnom korteksu (PFK), hipokampusu i amigdali mozga pacova...Post-traumatic stress disorder (PTSD) is a highly prevalent and impairing disorder. Despite the availability of pharmacological and evidence-based cognitive behavioral therapy, a considerable number of PTSD patients do not respond to the conventional therapy indicating that pathogenetic mechanisams of PTSD are currently not sufficiently explored. Single prolonged stress (SPS) is useful animal model of PTSD for understanding the pathophysiology of the disorder and the development of new treatments. A prevailing neurocircuitry model of PTSD emphasizes the role of the amygdala, as well as its interactions with the medial prefrontal cortex (mPFC) and hippocampus. Increasing evidence indicates that neuropathological and psychological alterations in PTSD sufferers are related to brain oxidative stress. The major sources of reactive oxygen species (ROS) in cells are mitochondrial respiratory chain and nicotinamide adenine dinucleotide phosphate (NADPH) oxidases. Excitatory-inhibitory disbalance through disfunctional GABA-ergic circuits is implicated in many psychiatric disorders. Parvalbumin inhibitory interneurons are very important for maintaining proper excitatory/inhibitory balance and high-frequency neuronal synchronization and could be implicated in pathological fear learning in PTSD. Also, many studies have shown the participation of different neuropeptides in the processing of stressful stimuli and the stress response. Aim: The aims of present dissertation were to elucidate the effects of single prolonged stress on: (1) oxidative stress parameters, including malondialdehyde (MDA) level, reduced glutathione (GSH) level, glutathione peroxidase (GPx) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity and expression of SOD1 and SOD2(2) possible sources of free radicals: mitochondrial respiratory chain by determining of Complex I and cytochrome c oxidase (COX) activity and NADPH oxidase by determining of the expression of membrane (gp91phox, p22phox) and cytosolic (p67phox) subunits of this enzyme; (3) total number of neurons (NeuN positive cells), number of parvalbumin (PV) and calbindin (CB) positive GABA-ergic neurons and number of substance P(SP), enkephaline (ENK) and galanine (GAL) positive peptidergic neurons in the rat prefrontal cortex, hippocampus and amygdala

An optimization of inner structures of the drying chamber of high temperature pneumatic drum drier

In this paper an analysis of the influence of parameters of flights from inner drying chamber structure and drying chamber is given. The influence of the following parameters on dryer working process is analyzed: number, shape and width of flights, level of coverage of cross-section drying chamber by material, rpm and drying chamber diameter. In the analytical expression for determining the amount of material seized by a curved flight, depending on the current position of the flight during drum rotation, a new parameter is introduced, compared to expression for a rectilinear flight. The expanded analytical expression could be used for optimization

Models of spin-orbit coupled oligomers

We address the stability and dynamics of eigenmodes in linearly-shaped strings (dimers, trimers, tetramers, and pentamers) built of droplets of a binary Bose-Einstein condensate (BEC). The binary BEC is composed of atoms in two pseudo-spin states with attractive interactions, dressed by properly arranged laser fields, which induce the (pseudo-) spin-orbit (SO) coupling. We demonstrate that the SO-coupling terms help to create eigenmodes of particular types in the strings. Dimer, trimer, and pentamer eigenmodes of the linear system, which correspond to the zero eigenvalue (EV, alias chemical potential) extend into the nonlinear ones, keeping an exact analytical form, while tetramers do not admit such a continuation, because the respective spectrum does not contain a zero EV. Stability areas of these modes shrink with the increasing nonlinearity. Besides these modes, other types of nonlinear states, which are produced by the continuation of their linear counterparts corresponding to some nonzero EVs, are found in a numerical form (including ones for the tetramer system). They are stable in nearly entire existence regions in trimer and pentamer systems, but only in a very small area for the tetramers. Similar results are also obtained, but not displayed in detail, for hexa- and septamers.Comment: Chaos, in pres

A multi-term boltzmann equation analysis of charged particle transport properties in electric and magnetic fields in gases

[Extract] Since the mid to late 1990s the theoretical analysis of charged particle transport processes in neutral gases in the presence of electric and magnetic fields has advanced considerably. For electron swarms in crossed electric and magnetic fields, the advancement was motivated by the desire to overcome the limitations of the two-term approximation for solving the Boltzmann equation and various types of equivalent/effective field approximations often employed to describe the impact of a magnetic field on the transport. The first systematic multi-term analysis for electron swarms under hydrodynamic conditions in the presence of uniform dc electric and magnetic fields was given by Ness [1] and since then a considerable number of papers has been published in a relatively short time. The situation up to 2002 was reviewed by White et al. [2] where a unified multi-term theory for solving the Boltzmann equation valid for both electrons and ions in the presence of time-dependent electric and magnetic fields was presented. This theory was recently employed to study the influence of an orthogonal magnetic field on the transient behavior of the diagonal diffusion tensor elements for swarms undergoing conservative collisions only [3]. Since ionization plays a vital role in plasma maintenance any transport theory must include rate coefficients, and correctly account for the effects of non-conservative collisions on drift and diffusion. With these remarks as background, we extend the previous theory [4] and in this work we present a theoretical and numerical investigation of hydrodynamic and non-hydrodynamic charged particle swarms in neutral gases under the influence of dc and ac electric and magnetic fields when non-conservative collisions are operative with applications of non-equilibrium magnetized plasma discharges to plasma processing, gas laser discharges and drift chambers for detection particles in mind