Learning to use gestures in narratives: developmental trends in formal and semantic gesture competence

This study analyses the way in which children develop their competence in the formal and semantic aspects of gesture. The analysis is focused upon the use of representational gestures in a narrative context. A group of 30 Italian children from 4 to 10 years was videotaped while telling a video cartoon to an adult. Gestures were coded according to the parameters used in Sign Languages analysis and analysed in terms of the acquisition of their properties, the accuracy of their execution and correctness in content representation.It was investigated also the development of the symbolic competence in relation both to the use of some of these parameters and to the representational strategies adopted. Results indicate a developmental trend in all the phenomena investigated and point out some formal similarities between gesture and Sign Languages

RNA editing

Uređivanje RNA opisuje molekularne procese koji uključuju post-transkripcijsku promjenu nukleotida molekule RNA u odnosu na kodirajuću DNA što je često nužno za uspostavljanje biološke funkcije. Odvija se u svim domenama života osim kod prokariota, te kod nekih RNA-virusa. Uređivanjem su zahvaćeni jezgrini, mitohondrijski te plastidni transkripti RNA, a uređivana RNA ne mora nužno kodirati za proteine. Uređivanje RNA se može svrstati u dvije skupine – supstitucijsko, u kojem dolazi do zamjene nukleotida te insercijsko ili delecijsko koje mijenja broj nukleotida u uređivanom transkriptu. Glavni predstavnici supstitucijskih uređivanja kod sisavaca jesu proteinski kompleksi APOBEC i ADAR. Protein APOBEC je citidinska deaminaza te provodi deaminaciju C→U, dok je protein ADAR adenozinska deaminaza te mijenja A→I. Kod praživotinja uređuje se mitohondrijska RNA. Za Trypanosoma karakteristična je insercija tj. delecija uridina kod gena koji kodiraju za proteine. Kod amebe Acanthoamoebe castelanii se uređuje molekula tRNA na 5'-kraju akceptorske petlje. Uređivanje kod biljaka najčešće se odnosi na modifikaciju C→U koja se odvija na mitohondrijskim i plastidnim transkriptima. RNA-virusi kao Ebolavirus i virus hepatitisa delta također bivaju podvrgnuti uređivanju RNA, pomoću vlastitih ili domaćinskih proteina, što ima značajan utjecaj na njihovu virulentnost. Uređivanje RNA je vrlo kompleksan i energetski skup proces te se postavlja pitanje kako je uopće došlo do njegove široke rasprostranjenosti. Model neutralne konstruktivne evolucije pokušava dati zadovoljavajući odgovor na to pitanje gledajući na postojanje sustava uređivanja RNA kao na sustav koji preuzima dio odgovornosti u procesu ispravljanja grešaka u DNA. Pri tome se štetne mutacije ispravljaju ne na razini DNA, već na razini RNA.RNA editing describes molecular processes that include posttranscriptional changes in RNA nucleotide sequence compared to coding DNA sequence and may be necessary for their biological function. It is spread in eukaryotes, and it also occurs in some RNA viruses. Nucleus, mitochondria and plastids are cellular compartments in which RNA editing occurs. Also transcripts to be edited are not necessarily protein coding. There are two main groups of RNA editing – editing by substitution of nucleotides and insertions or deletions in which number of nucleotides in RNA transcripts is changed. For substitution editing, there are two main protein systems in mammals – APOBEC and ADAR. APOBEC has cytidine deaminase activity and conducts C to U deamination whereas ADARs are adenosine deaminases and they change A→I. Protozan RNA editing includes editing of mitochondrial RNA transcripts. Typical editing for trypanosomatid protozoans involves insertion as well as deletion of U in protein coding RNA transcripts. RNA editing in protoza Acanthoamoebe castelanii includes editing of 5’-end of tRNA acceptor stem. In plants C to U editing is the most common type of modification. Mitochondrial and plastids RNAs are targeted for editing in this case. RNA of viruses, like Ebolavirus and hepatitis delta virus, can also undergo editing using its own or host protein complexes. It can largely affect their virulence. RNA editing is complex and energetically expensive process so there is open question why did it even arose. Constructive neutral evolution model tries to give satisfying answer. It proposes that RNA editing system emerged after allowing mutations to happen. RNA editing allows corrections of DNA mutations on RNA level and therefore it permits DNA-encoded information to degenerate progressively

Electric resistivity of organic conductor K-(BEDT-TTF)2Cu2(CN)3

U ovom radu su proučavana svojstva električne otpornosti u temperaturnom rasponu od ~300K (sobne temperature) do ~20K (do kuda je dostupna aparatura davala pouzdane rezultate), organskog kristala κ-(BEDT-TTF)2Cu2(CN)3. Na temelju provedenih mjerenja ispitana su slaganja rezultata mjerenja s teorijom, odnosno s Arrheniusovim zakonom i teorijom preskoka promjenjivog dosega. U metodičkom dijelu rada predstavljen je jedan način kako bi se mogao održati istraživački tip nastave na temu električnog otpora u srednoj školi sa četverogodišnjim programom fizike.The subject of this study is electric resistivity in temperature range from ~300K (room temperature) to ~20K (temperature at which available apparatus was giving reliable results), organic crystal κ-(BEDT-TTF)2Cu2(CN)3. The study examines connection between measured results and the theory, respectively with Arrhenius law and theory of variable range hopping. Educational part shows an exploratory teaching method how to present electric resistance in high school within four year program of physics

Beyond Orality: The Case of Sign Languages

The present paper reviews the main approaches developed for the linguistic analysis of sign languages, discussing the different theoretical assumptions and methodological implications applied along with the history of sign language studies. Sign language research demanded a revolution in some core beliefs of language, namely the linearity of speech, discreteness, and arbitrariness, providing a new way to look at the nature of language