Copolymerisation as a way to enhance the electrochromic properties of an alkylthiophene oligomer and a pyrrole derivative: copolymer of 3,3'" dihexyl-2,2':5',2":5",2'"-quaterthiophene with (R)-(-)-3-(1-pyrrolyl)propyl-N-(3,5-dinitrobenzoyl)-α-phenylglycinate

The copolymerisation of 3,3'" Dihexyl-2,2':5',2":5",2'"-quaterthiophene (DHQT) and (R)-(-)-3-(1-pyrrolyl)propyl-N-(3,5-dinitrobenzoyl)-α-phenylglycinate (DNBP) was successfully performed electrochemically in acetonitrile (CH3CN) containing tetrabutylammonium tetrafluoroborate ((C4H9)4NBF4) by direct oxidation of monomer mixtures in different feed ratios. Copolymerisation improved the properties of the films of both polymers PDHQT and PDNBP, in respect to the adhesion of PDHQT onto ITO/glass surface and the chromatic contrast of these electrochromic materials. PDHQT, PDNBP and P(DHQT-co-DNBP) films were characterised by FTIR spectroscopy, fluorescence spectroscopy, Scanning Electron Microscopy (SEM) and spectroelectrochemical techniques. Solutions of PDHQT and its copolymers with DNBP (independently of the feed ratio) in N-methylpyrrolidone are fluorescent with emission bands at 555 and 585 nm when excited at 375 nm. Reversible changes in the hue and saturation occur in all the copolymer films from yellow or orange in the reduced state to green or blue in the oxidised state, but were dependent on the proportion of the comonomers used to prepare the copolymers. These changes are more significant for P(DHQT-co-DNBP) films deposited onto ITO/glass with 1:5 feed ratio, as shown by the track of the CIE 1931 xy chromaticity coordinates and by the electrochromic parameters in which this film (thickness 0.8±0.2 μm) presented chromatic contrast (Δ%T) at 660 nm of 62%, coloration efficiency (η) of 266 cm2 C-1 and stability to redox cycling (Δ%T=17% at the 1000th cycle). Therefore, these copolymers are potentially applicable in displays and optoelectronic devices as electrochromic and fluorescent materials

Gendered representations in Hawai‘i’s anti-GMO activism

The aim of this article is to analyse some of the representations of intersectional gender that materialise in activism against genetically modified organisms (GMOs). It uses the case of Hawai‘i as a key node in global transgenic seed production and hotspot for food, land and farming controversies. Based on ethnographic work conducted since 2012, the article suggests some of the ways that gender is represented within movements against GMOs by analysing activist media representations. The article shows how gender, understood intersectionally, informs possibilities for movement-identification, exploring how themes of motherhood, warrior masculinities and sexualised femininities are represented within these movements. The article suggests that some activist representations of gender invoke what could be considered as normative framings of gender similar to those seen in other environmental, food and anti-GMO movements. It is suggested that these gendered representations may influence and limit how different subjects engage with Hawai'i anti-GMO movements. At the same time, contextual, intersectional readings demonstrate the complex histories behind what appear to be gender normative activist representations. Taken together, this emphasis on relative norms of femininities and masculinities may provide anti-GMO organising with familiar social frames that counterbalance otherwise threatening campaigns against (agri)business in the settler state. Understood within these histories, the work that gender does within anti-GMO organising may offer generative examples for thinking through the relationships between gendered representations and situated, indigenous-centred, food and land-based resistances

Características do sêmen a fresco e descongelado de garanhões da raça Nordestina

RESUMO: Este estudo descreveu as características seminais, da membrana plasmática e do acrossoma de espermatozoide congelado/descongelado de 19 ejaculados de garanhões da raça Nordestina. Os aspectos analisados incluíram os parâmetros físicos do sêmen fresco; a motilidade e a longevidade do sêmen diluído e descongelado; a morfologia espermática, integridade funcional e estrutural da membrana plasmática do espermatozoide e a habilidade de ligação do espermatozoide à membrana perivitelina da gema do ovo de galinha do sêmen descongelado. As variáveis foram avaliadas pela ANOVA com post hoc teste de Student Newman-Keuls (P<0,05). A MT e a MP foram maiores (P<0,05) no sêmen diluído do que no descongelado. A percentagem média de defeitos maiores, menores e totais foi muito inferior ao limite recomendado pelo CBRA. A porcentagem de reativos ao HOST foi de 14,21±1,12% e a porcentagem média de membranas íntegras detectadas pelo teste supravital de 62,22±9,06% e pela sonda SYBR-14 de 81,47±26,90. O número médio de espermatozoides ligados à MPV após a descongelação do sêmen foi de 230,39±57,09. A MT e MP no tempo 0 min do TTR foi superior (P<0,05) em relação a 150 min, não diferindo nos tempos 10 min e 30 min. Os resultados demonstram que a utilização dos testes laboratoriais adicionais ajudam no processo de avaliação das amostras, possibilitando a obtenção de informações mais confiáveis e precisas. Embora a criopreservação tenha provocado queda na motilidade seminal, o uso de diluidor contendo amidas minimizou os danos osmóticos nas células espermáticas e manteve a integridade morfológica, funcional e estrutural da membrana plasmática do espermatozoide. Estes resultados são um referencial em estudos futuros uma vez que, inexistem dados comparativos nesta raça