Milkica Nešić

Exploring college students' generational differences in Facebook usage

In recent years the usage of social networks among students has become the subject of numerous studies. In this study we were interested in differences in patterns of online behaviour and the use of Facebook (FB) among the second and third generation of students. The results showed that 66% of the second year students had a FB account, while in the third generation all of the respondents had a FB account. One third of the second year students avoid any involvement in FB. Lack of interest was one of the main reasons the respondents indicated for not being engaged in FB, as well as their unwillingness to put personal information online. Currently, most of them are satisfied using FB, and do not plan to turn off their profile. The newer generations of students use FB mainly for overcoming boredom. Based on the results of the study, it can be concluded that the time spent online increases, as well as the number of FB users, and also the number of virtual friends increases in order to exchange information. We concluded that the number of users of Facebook increases among older students in comparison to younger one.We found that increasing the number of friends on Facebook is more pronounced among older students.Membership in groups is more popular within older students.Most students do not consider that they are addicted to Facebook.

Formant structure of the voice during the intensive acute hypoxia.

The influence of intensive acute hypoxia on the frequency-amplitude formant vocal O characteristics was investigated in this study. Examinees were exposed to the simulated altitudes of 5,500 m and 6,700 m in climabaro chamber and resolved Lotigs test in the conditions of normoxia, i.e. pronounced the three-digit numbers beginning from 900, but in reversed order. Frequency and intensity values of vocal O (F1, F2, F3 and F4), extracted from the context of the pronunciation of the word eight (osam in Serbian), were measured by spectral speech signal analysis. Changes in frequency values and the intensity of the formants were examined. The obtained results showed that there were no significant changes of the formant frequencies in hypoxia condition compared to normoxia. Though, significant changes of formants intensities were found compared to normoxia on the cited altitudes. The rise of formants intensities was found at the altitude of 5,500 m. Hypoxia at the altitude of 6,700 m caused the significant fall of the intensities in the initial period, compared to normoxia. The prolonged hypoxia exposure caused the rise of the formant intensities compared to the altitude of 5,500 m. In may be concluded that, due to different altitudes, hypoxia causes different effects on the formants structure changes, compared to normoxia.

Neuroscience of Nonverbal Communication

Nonverbal communication is essential for human social interaction, either through static physical cues, such as phenotypic traits, facial and body appearance, or dynamic cues, such as faces and bodies in motion. Communication may be via touching, i.e., haptic communication, or at the spatial distance, i.e., proxemic communication. Communication among animals is most commonly mediated by olfactory signals. In many primates, sense of smell is significantly reduced compared to the smell of other vertebrates, while the visual modality is critical for social communication. About a quarter of the cortex is devoted to human visual perception and analysis. Visual modality provides a large amount of information about the identity of other individuals, their social status, emotional state and intended actions. The importance of face processing for survival is reflected in the extraordinary memory abilities of facial features and expressions in humans and other primates, as well as expressed powers of observation of subtle differences between faces.

Inhibitory effect of aqueous and ethanolic garlic (Allium sativum L., Lilliaceae) extracts on the rat atria.

The acute negative inotropic and chronotrophic effects of aqueous and alcoholic garlic extracts (Allium sativum L.) on spontaneous and adrenalin-stimulated contractions of the Wistar rat atria were investigated. The addition of garlic extracts to isolated rat atria evoked negative inotropic and chronotropic effects. Ethanolic garlic extract exerts much stronger negative inotropic (58.33 ± 14.76%) effects than aqueous extract (43.66 ± 16.32%). The difference in frequency reduction is especially conspicuous. Aqueous garlic extract very slightly affects the frequency, while ethanolic extract reduces it by more than 40%. In addition to these effects, the positive inotropism and chronotropism induced by the addition of noradrenaline, were much more antagonized by ethanolic garlic extract than by aqueous extract. Moreover, ethanolic garlic extract establishes sinus rhythm in the atria with extrasystoles induced by noradrenaline.

Contralateral Hemisphere Activation by Unilateral Hand Contraction: ReExamining of Global and Local Attention

While previous studies have shown that left- (vs. right-) hand contractions can improve the performance of global (vs. local) attention, these results were inconsistent in certain behavioral studies in which the left cerebral hemisphere was found to be specialized for local attention, while the right hemisphere was not specialized for global attention. Thus, we reexamined whether different global (vs. local) attention performances follow left- (vs. right-) hand contractions due to right (vs. left) hemisphere activation. We recruited 100 right-handed healthy female, university student (aged 19–26 years) participants. We used the Navon task to present 80 letter-stimuli (40 in the global task; 40 in the local task) to either the participants’ left or right visual fields. Half of the participants (randomly selected) were instructed to squeeze a dynamometer with the left hand, while the other half squeezed with the right hand, prior to completing the Navon task. In line with previous research, we observed a perceptual advantage of global (large letters) over local (small letters) stimuli. Participants who contracted the right hand showed an enhanced local attention performance (from left hemisphere activation), whereas those who contracted the left hand did not improve global attention performance (from right hemisphere activation). Thus, we supported prior behavioral research suggesting that hemispheric asymmetry for attention processing is evident for left but not right cortical hemisphere processing.

System Usability Scale Implementation for Interfaces on Mobile Touch Screen Devices Assessment

The indisputable fact is that touch screen mobile devices flooded the marketplace and that they have become an essential element in the enormous number of fields and applications. But a huge presence, as well as daily use, does not necessarily unambiguously reflect their optimal usability. Therefore, it is essential to adopt appropriate research methodologies that can evaluate the usability of mobile device interfaces. The main focus of the study was to examine a practical tool for usability assessment in a mobile work context which has to be simple and above all, proved to give a single score as its outcome. To achieve this goal System Usability Scale (SUS) was applied to test the Tablet PC usability. This study contributed with the proposal of a framework for usability testing which could help, both practitioners and researchers to make decisions how to improve the usability of interfaces on touch screen mobile devices.

Gender differences in the relations between vocal and graphomotoric characteristics in stress condition

The aim of this investigation was to explore exam stress influences on gender differences in the relations between vocal and graphomotoric characteristics. One hundred students of medicine (equal number of males and females) participated in this study. The subjects had to pronounce aloud and simultaneously to write the results of subtracting serial seven (SSS) arithmetic task, beginning from thousand, for five minutes, just before the exam. Voice characteristics (loudness, duration of pronunciation and pauses) and the magnitude and distance of the written numbers, written length of paper and number of rows during graphomotoric part of task were analyzed. The distance among written results and among rows positively correlated with pauses between utterances of correct numbers, whereas distance among written results negatively correlated with the quotient between utterances and pauses in women. Also, the distance from left margin of the written paper negatively correlated, whereas broad and length of written part of paper positively correlated with average and maximal intensity of voice in women. The distance among written results negatively correlated with maximal intensity of voice in men. The exam stress induces gender dependent correlations of written and oral speech during SSS task solving.

Perception and attitudes towards digital billboards

Given that digital billboards are a relatively new phenomenon in Belgrade, we aimed to examine how its citizens really perceive them, as well as to reveal their attitudes towards digital billboards. The results showed that the length of exposure to advertising content has a crucial influence on their perception.

The risks associated with using a mobile phone by young drivers

AbstractA substantial body of research has shown that mobile phone usage could lead to the impairment of driving performance and increase the likelihood of driving accidents. The use of mobile phone while driving is a major problem for inexperienced drivers. The reason for this lies in the fact that they have not developed abilities to process different types of information simultaneously. Mobile phone use may result in reduced attention allocation to the various tasks during driving. The research of young drivers’ habits related to mobile phone usage while driving is presented in this paper. A series of questions were administered, including along with demographic measures, self-reported number of traffic accidents and several kinds of driving behaviour such as alcohol consumption. The results have shown that 68% of young drivers used mobile phone while driving. Additionally, a relationship was found between frequency of mobile phones usage and the number of traffic accidents, consequences of traffic acc...

Gender Differences in Prosodic Characteristics of Speech in the Task of Serial Subtracting of Sevens

Summary Significant differences in speech between genders are contained in nonsegmental correlates, i.e. in the prosody and paralinguistics. Pronunciation differences between genders are more numerous than those in grammatical form. This study aims to detect temporal prosodic patterns and investigate gender differences in performing serial sevens subtraction (SSS). One hundred students of medicine (equal number of males and females) voluntarily participated in the investigation. SSS was performed by asking the participant to perform mental arithmetic consisting of repeatedly subtractions of sevens, beginning from one thousand. The students had to pronounce aloud and simultaneously write the results for five minutes. The original program for the analysis of digital signals (ADS) converted the speech signal samples into digital data. MANOVA showed significant gender differences for a group of characteristics of the SSS test: F (11, 75)=4.06, p=0.000. The number of samples per each minute and the total number of samples during five minutes was higher in males compared to females. The average length of articulation of three-digit numbers, average length of articulation and length of pauses between the linguistic units, as well as between the samples, was shorter in males for each of these five minutes and for the „average“ minute. The maximum intensity of speech was higher in males for each of the five minutes. Average duration of mispronunciations, with end results being correct, was longer in women in the first, second, and fourth minute, as well as for the „average“ minute. A conclusion may be drawn that shorter utterances and pauses in men suggest the advantage on the part of men in SSS task, and not greater verbal fluency in general in men. Sažetak Značajne razlike govora među polovima su u nesegmentalnim korelatima, tj. u prozodiji i paralingvistici. Razlike u izgovoru muškaraca i žena su mnogo brojnije nego razlike u gramatičkoj formi. Cilj ovog istraživanja bio je da se detektuju vremenski prozodični obrasci i istraže polne razlike pri rešavanju zadatka serijskog oduzimanja sedmica (SSS). U istraživanju je dobrovoljno učestvovalo 100 studenata medicine (podjednak broj muškog i ženskog pola). Zadatak ispitanika je bio da se počev od broja 1000 sukcesivno oduzima po sedam, glasno izgovarajući rezultat, uz istovremeno ispisivanje brojeva, u vremenskom trajanju od 5 minuta. Originalan program za analizu digitalnih signala (ADS) uzorke govornog signala pretvara u digitalni zapis. MANOVA je pokazala značajne razlike po polu za grupu obeležja testa SSS: F (11, 75)=4,06, p=0,000. Broj uzoraka za svaki minut posebno, kao i ukupan broj uzoraka za svih pet minuta veći je za muški nego za ženski pol. Prosečna dužina izgovora trocifrenog broja, prosečna dužina izgovora i prosečno trajanje pauze između lingvističkih jedinica, kao i između uzoraka, kraće je za muški pol za svaki od pet minuta, kao i za „prosečan” minut. Maksimalni intenzitet izgovora veći je za muški pol, za svih pet minuta. Prosečno trajanje pogrešnih izgovora, kada je krajnji rezultat tačan, duže je za ženski nego za muški pol i to u prvoj, drugoj i četvrtoj minuti, kao i za prosečni minut. Može se zaključiti da kraće trajanje izgovora i pauza osoba muškog pola govori o prednosti ovog pola pri rešavanju SSS zadatka, a ne o izraženijoj verbalnoj fluentnosti uopšte za muški pol.