1,384 research outputs found

    Post-embryonic Development of Intramandibular Glands in Pachycondyla verenae (Forel) (Hymenoptera: Formicidae) workers

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    The current knowledge of intramandibular glands in Hymenoptera is focused on occurrence and morphology in adult insects. This is the first report regarding the post-embryonic development of intramandibular glands in a “primitive” ant, Pachycondyla verenae. In this study, we analyzed mandibles of prepupae, white-eyed, pink-eyed and black-eyed pupae, pupa of pigmented body pupae, and adults. Adult workers of P. verenae have intramandibular glands with epidermal secretory cells of class I and isolated glands of class III, and both glands have onset differentiation in pink-eyed pupae. Some histological sections were submitted to histochemical test for total proteins and neutral polysaccharides. Histochemical tests showed occurrence of polysaccharides and proteins in epidermal secretory cells of class I from the white-eyed pupae, polysaccharides and proteins in pink-eyed pupae to black-eyed pupae in both glands classes I and III and presence of polysaccharides in adult ants also in both gland classes I and III. Intramandibular glands of classes I and III in P. verenae workers differentiate during pupation, with onset occurring in pink-eyed pupae, and completion occurring in black-eyed pupae

    The family role in children׳s sleep disturbances: Results from a cross-sectional study in a Portuguese Urban pediatric population

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    BACKGROUND: Sleep Disorders (SlD) are frequently undervalued complaints in childhood. Several factors influence sleep, particularly socio-cultural environment and medical conditions such as breathing disorders. Poor sleep hygiene has physical, educational and social consequences. In Portugal, there are few published studies about children׳s sleep habits and rarely based on validated questionnaires. AIM: To study the prevalence of SlD and associated factors, in an outpatient pediatric population of a Primary Health Care Center (PHCC). METHODS: Cross-sectional study of children admitted to a PHCC on a suburban area of Lisbon. Children Sleep Habits Questionnaire, validated for the Portuguese population (CSHQ-PT) for the screening of SlD (cut-off=44), was applied to parents, as well as a demographic inquiry. Body mass index z-score was evaluated. Children scoring 44 or above were sent to Pediatric Sleep Disorders consultation (PSDC). Parametric and non-parametric tests were used whenever appropriate. RESULTS: From 128 children, 57.8% were male; the median age was 6.0 years (P 25=5.0; P 75=8.0). The median of cohabitants per family was 4.0 (P 25=3.0; P 75=5.0); 21.1% lived in a single-parent family. From CSHQ-PT, 59.4% (76) scored above the cut-off. Data showed that children from a single-parent family have more SlD (p=0.048), particularly parasomnia (p=0.019). Children with sleep disordered breathing (SDB) suffer more daytime sleepiness (p=0.034). From 63 children sent to PSDC, 33 attended. Regarding these children, a difference was found between BMI z-scores of those with and without SDB (p=0.06). CONCLUSION: Family structure plays a non-negligible role in children's sleep habits. Daily performance of children with SDB may become compromised

    Effect of genotype, finishing system, and sex on physiochemical characteristics of goat meat

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    Seventy-eight kids of both sexes and five genotypes were used: Alpine, 1/2 Boer + 1/2 Alpine (1/2 BA), 3/4 Boer + Alpine, 1/2 Anglo-nubian + 1/2 Alpine and "tricross" (1/2 Anglo-nubian + 1/4 Boer + 1/4 Alpine) with initial average weight of 14.1 +/- 2.5. The objective was to evaluate the effect of genotype, finishing system, and sex on the physiochemical characteristics of goat meat. Finishing systems were: ST1 - kid + dam in pasture and ST2 - weaned kid and feedlot. Kids in ST1 were kept in an area with Panicum maximum cv. Tanzania, and after grazing, water and mineral salt/mix were fed ad libitum to the animals. The animals in ST2 - were confined in collective pens distributed according to genotypes and received diet with 16% CP and 73% TDN. The values of pH, a(star) (red content), Cooking Loss (CL), and Ether Extract (EE) percentage were influenced by genotype. Values for red content (a(star)) and L-star (brightness), CL and percentages of moisture, protein, EE, and ash were influenced by the finishing system. Longissimus dorsi muscle from animals 1/2 BA exhibited better physiochemical characteristics. For greater tenderness and higher percentages of fat, consumers should choose female kid goat meat.31499299

    Ultrahard carbon film from epitaxial two-layer graphene

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    Atomically thin graphene exhibits fascinating mechanical properties, although its hardness and transverse stiffness are inferior to those of diamond. To date, there hasn't been any practical demonstration of the transformation of multi-layer graphene into diamond-like ultra-hard structures. Here we show that at room temperature and after nano-indentation, two-layer graphene on SiC(0001) exhibits a transverse stiffness and hardness comparable to diamond, resisting to perforation with a diamond indenter, and showing a reversible drop in electrical conductivity upon indentation. Density functional theory calculations suggest that upon compression, the two-layer graphene film transforms into a diamond-like film, producing both elastic deformations and sp2-to-sp3 chemical changes. Experiments and calculations show that this reversible phase change is not observed for a single buffer layer on SiC or graphene films thicker than 3 to 5 layers. Indeed, calculations show that whereas in two-layer graphene layer-stacking configuration controls the conformation of the diamond-like film, in a multilayer film it hinders the phase transformation.Comment: Published online on Nature Nanotechnology on December 18, 201
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