168 sati tišine Duda, Katerina
Mjera,
12/2020, Volume:
2, Issue:
3
Web Resource
Open access
Prilog je derivacija umjetničkog rada "Hvala, a sad više ništa". Čine ga fragmenti teksta, fotografije, citati iz razgovora sa stanovnicima i drugi vizualni materijala na temu turizma i grada ...Dubrovnika. Otvara se pitanje života u gradu koji je potpuno podređen turističkim izmjenama, pitanja zagađenja bukom, kao i njegove reprezentacije.
Subkulturna skupina graffiti writing, koja nosi etiketu delinkventne, prepoznaje se po ostavljanju tragova po gradskim fasadama. Cilj graffiti writinga isključivo je pisanje svog nadimka, ostavljanje
...traga u što većoj količini i što savršenije u odnosu na pravila izričaja writinga. Slova i riječi postaju isključivo vizualni znak koji će writeru dati zasluženi integritet. Kao posebno zanimljivi spominju se odnosi unutar skupine temeljeni na strogo određenoj hijerarhiji i kodiranom ponašanju. Jednako tako, promatrajući writing u kontekstu hip-hop kulture, koja je vrlo često rodno određena, zanimljivo je pitanje odnosa prema rijetkim writericama. Kako je izvorno nastao u siromašnom društvu, materijali za crtanje najčešće su bili ukradeni; tako se među writerima do danas razvila vlastita koncepcija privatnog i javnog, dobrog i lošeg. Paradoks je u tome da pokret, koji je nastao kao underground, kao nešto nedopustivo i u sukobu sa zakonom, danas možemo naći kao dio kulturnog mainstreama. Taj ulazak graffiti writinga u mainstream zaslužan je za njegov nestanak
u izvornom smislu. Pokret koji je danas prisutan prije se može nazvati post-writingom, ne samo zbog njegove komercijalizacije već i zbog promjene samog koncepta writinga. Tendencija prema sterilizaciji i elitizaciji gradova, gdje nadzor prostora videokamerama postaje gotovo neizbježan, ujedno uzrokuje i nestajanje jedne subkulturne skupine.
Large icosahedral viruses that infect bacteria represent an extreme of the coevolution of capsids and the genomes they accommodate. One subset of these large viruses is the jumbophages, tailed phages ...with double-stranded DNA genomes of at least 200,000 bp. We explored the mechanism leading to increased capsid and genome sizes by characterizing structures of several jumbophage capsids and the DNA packaged within them. Capsid structures determined for six jumbophages were consistent with the canonical phage HK97 fold, and three had capsid geometries with novel triangulation numbers (T=25, T=28, and T=52). Packaged DNA (chromosome) sizes were larger than the genome sizes, indicating that all jumbophages use a head-full DNA packaging mechanism. For two phages (PAU and G), the sizes appeared very much larger than their genome length. We used two-dimensional DNA gel electrophoresis to show that these two DNAs migrated abnormally due to base modifications and to allow us to calculate their actual chromosome sizes. Our results support a ratchet model of capsid and genome coevolution whereby mutations lead to increased capsid volume and allow the acquisition of additional genes. Once the added genes and larger capsid are established, mutations that restore the smaller size are disfavored.
A large family of viruses share the same fold of the capsid protein as bacteriophage HK97, a virus that infects bacteria. Members of this family use different numbers of the capsid protein to build capsids of different sizes. Here, we examined the structures of extremely large capsids and measured their DNA content relative to the sequenced genome lengths, aiming to understand the process that increases size. We concluded that mutational changes leading to larger capsids become locked in by subsequent changes to the genome organization.
Composites consisting of iron aluminide and iron silicide phases were studied in this work. Powders of iron aluminide and iron silicide were prepared by mechanical alloying separately. Subsequently, ...they were blended in three different proportions and sintered by the SPS method under various conditions. After sintering, the composites are composed of FeAl and amounts of other silicides (Fe
Si
and Fe
Si). Ternary Fe-Al-Si phases were not determined, even though their presence was predicted by DFT calculations. This disagreement was explained by steric factors, i.e., by differences in the space lattice of the present phases. Hardness and tribological properties were measured on composites with various weight ratios of iron aluminide and iron silicide. The results show that sintered silicides with the matrix composed of iron aluminide reach comparable hardness to tool steels. The composites with higher mass ratios of iron aluminide than silicide have higher hardness and better tribological properties.
The presented research aimed to thoroughly investigate the effects of print speed on glycol-modified polyethylene terephthalate (PETG) printed using fused filament fabrication (FFF) technology. The ...printed product microstructure and morphology were evaluated by a scanning electron microscope (SEM), a surface roughness tester, and an X-ray microtomograph (microCT). Higher print speeds give rise to voids and other morphological defects inside the printed product and on its surface. Print speed also has a considerable impact on the surface profile and pores present inside the samples. A non-monotonic dependence of polymer chain orientation on print speed was found using polarized Raman spectroscopy but is unlikely to play an important role in forming the voids on the surface. Some micromechanical properties (Vickers microhardness, Young's modulus, the work of indentation) slightly depend on the print speed. Potential relationships between the micromechanical properties and the polymer chain orientation were observed too. Besides a detailed characterization of the printed products, various mechanisms involved in the printing process and affecting the final product properties are discussed too. Print speeds up to 60 mm s−1 were identified as suitable for our PETG samples.
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•Detailed characterization of surface profile and roughness, structural defects, and pores.•The print speed affects the surface profile as well as the pores in the PETG material.•High print speed causes material under- or over-extrusion depending on printing path shape.•A non-monotonic dependence of polymer chain alignment on print speed was found.•Micromechanical properties (Young's modulus, …) slightly depend on print speed.
Hunting, as a component of traditional indigenous livelihoods, can play either positive or negative role in biodiversity conservation by maintaining traditional lifestyles that are conducive to ...conservation or by endangering vulnerable hunted species. Quantitative data on changes in hunting skills in indigenous communities driven by education, employment, and other lifestyle changes are lacking. Here we assess hunting skills of young people in Papua New Guinea (PNG). We use a sample of 7818 secondary school students, representing 15% of the most educated individuals in their age cohort. Students self-assessed their hunting skills as none (34% of respondents), poor (46%), and good (20%). Male students reported significantly higher hunting skills than female students. Hunting skills were positively correlated with knowledge of local bird species and with other traditional skills (growing food, using medicinal plants, building houses). They were negatively correlated with math and English skills, as well as with the transportation accessibility of the village/town where the students grew up. Students who grow up in town reported significantly lower hunting skills than those who grew up in village. These results show that students' hunting skills are already low, and the trends in their socio-cultural drivers predict a further decline in the future. The increasing disconnection from the natural environment and the declining attractiveness of hunting as prestigious activity for the young and educated people are part of a broader trend of loss of ethnobiological knowledge in PNG's indigenous communities. While it may reduce hunting pressure on some endangered species, it may also remove traditional incentives for conservation in rainforest-dwelling communities.
Significance
Around the world, more than 7,000 languages are spoken, most of them by small populations of speakers in the tropics. Globalization puts small languages at a disadvantage, but our ...understanding of the drivers and rate of language loss remains incomplete. When we tested key factors causing language attrition among Papua New Guinean students speaking 392 different indigenous languages, we found an unexpectedly rapid decline in their language skills compared to their parents and predicted further acceleration of language loss in the next generation. Language attrition was accompanied by decline in the traditional knowledge of nature among the students, pointing to an uncertain future for languages and biocultural knowledge in the most linguistically diverse place on Earth.
Papua New Guinea is home to >10% of the world’s languages and rich and varied biocultural knowledge, but the future of this diversity remains unclear. We measured language skills of 6,190 students speaking 392 languages (5.5% of the global total) and modeled their future trends using individual-level variables characterizing family language use, socioeconomic conditions, students’ skills, and language traits. This approach showed that only 58% of the students, compared to 91% of their parents, were fluent in indigenous languages, while the trends in key drivers of language skills (language use at home, proportion of mixed-language families, urbanization, students’ traditional skills) predicted accelerating decline of fluency to an estimated 26% in the next generation of students. Ethnobiological knowledge declined in close parallel with language skills. Varied medicinal plant uses known to the students speaking indigenous languages are replaced by a few, mostly nonnative species for the students speaking English or Tok Pisin, the national lingua franca. Most (88%) students want to teach indigenous language to their children. While crucial for keeping languages alive, this intention faces powerful external pressures as key factors (education, cash economy, road networks, and urbanization) associated with language attrition are valued in contemporary society.
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