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Hydroxyapatite (HAP) is a bioceramic used in the medical and dental areas as a bone replacement factor due to its chemical similarity to the mineral phase of bones and teeth. Its use in implants stimulate the growth of bone tissue, showing no toxicity or rejection of the host tissue. Its nanostructured form has been shown to be a viable alternative for photoprotection when doped with metal ions, such as trivalent chromium (Cr+³). Due to the reach of this form among the population, this work evaluated the mutagenic potential of pure nanostructured hydroxyapatite (HAP) and doped with trivalent chromium (Cr+³) (HCrIII) by means of the Somatic Mutation and Recombination Test (SMART Test) on Drosophila melanogaster Meigen, 1830 (Diptera: Drosophilidae) wings. Larvae resulting from standard crosses (ST) and high metabolic bioactivation (HB), treated with PAH and with HCrIII at concentrations 16.66 mg/mL, 8.33 mg/mL, and 4.16 mg/mL. As positive and negative controls, urethane and dodecyl sulfate sodium (SDS) were used, respectively. The frequencies of the different categories of mutant spots observed in offspring of HAP (HAP) and HCrIII treated crosses were not significantly different from those observed in the negative control. These data show that pure and chromium-doped (Cr+³) nanoestructured hydroxyapatite do not exhibit mutagenicity.

A poluição aquática da origem antropogênica é prejudicial aos ecossistemas e pode causar danos ao DNA dos indivíduos que vivem neles. O presente estudo teve como objetivo analisar o potencial mutagênico de poluentes no rio Paramopama, um afluente do rio Vaza Barris, utilizando o teste de micronúcleos (TMN) em Mytella falcata (Sururu), que detecta rupturas cromossômicas neste organismo experimental. Foram realizadas duas coleções, nos meses de agosto de 2015 e maio de 2016, nas quais foram preparadas lâminas de amostras de brânquias de M. falcata para a observação de micronúcleos. A freqüência de micronúcleos encontrados nas amostras variou de 6% a 23% ao longo do rio, demonstrando a presença de contaminantes com efeito mutagênico nas áreas estudadas do rio Paramopama.

We consider the dynamical one-dimensional Mindlin–Timoshenko model for beams. We study the existence of solutions for a contact problem associated with the Mindlin–Timoshenko system. We also analyze how its energy decays exponentially to zero as time goes to infinity. Copyright © 2008 John Wiley & Sons, Ltd.

Summary The occurrence and distribution of nine selected antibiotics were investigated in a small Mediterranean stream (Arc River, Southern France) during the winter and the spring season. Carbamazepine and clarithromycin were the most frequently detected compounds in water. Clarithromycin was determined at high μg/L levels in river water during the winter season due to the lack of dilution by background water while clarithromycin and azithromycin were ubiquitous in sediment. These contamination levels were at one order of magnitude higher than those reported in large European rivers. It could be shown that clarithromycin can be regarded as a priority antibiotic to be monitored in river waters mainly because this chemical showed high persistence in water and underwent slow dissipation processes in sediment.

We present new optical observations of the HH 111 Herbig-Haro jet using the Gemini Multi Object Spectrograph in its Integral Field Unit mode. Eight fields of 5" x 3.5" have been positioned along and across the HH 111 jet, covering the spatial region from knot E to L in HH 111 (namely, knots E, F, G, H, J, K and L). We present images and velocity channel maps for the [O I] 6300+6360, Halpha, [N II] 6548+6583 and [S II] 6716+6730 lines, as well as for the [S II]6716/6730 line ratio. We find that the HH 111 jet has an inner region with lower excitation and higher radial velocity, surrounded by a broader region of higher excitation and lower radial velocity. Also, we find higher electron densities at lower radial velocities. These results imply that the HH 111 jet has a fast, axial region with lower velocity shocks surrounded by a lower velocity sheath with higher velocity shocks., Comment: 10 pages, 10 figures, accepted for publication in AJ

We investigate a initial-boundary value problem for the nonlinear beam equation with variable coefficients on the action of a linear internal damping. We show the existence of a unique global weak solution and that the energy associated with this solution has a rate decay estimate. Besides, we prove the existence and uniqueness of non-local strong solutions. Copyright © 2004 John Wiley & Sons, Ltd.

Com o objetivo de avaliar o efeito da baixa temperatura e do carbureto de cálcio na emergência de túberas-semente de inhame, cultivar Da Costa, foi conduzido um experimento no período de outubro de 1998 a março de 1999, em Areia-PB. Para se avaliar a influência da baixa temperatura sobre a quebra de dormência das túberas-semente, as mesmas foram armazenadas em câmara fria à temperatura de 5ºC e umidade relativa de 90% em quatro períodos (10; 15; 20 e 25 dias). Para se avaliar a eficiência do carbureto de cálcio na quebra da dormência das túberas, as mesmas foram acondicionadas em sacos de polietileno preto com carbureto de cálcio na proporção de 60 g/kg de túberas e armazenadas em condições de galpão aberto (temperatura média de 27ºC e umidade de 64%), em quatro períodos (10; 15; 20 e 25 dias). Como testemunhas foram utilizadas túberas acondicionadas em sacos de polietileno sem carbureto de cálcio e túberas armazenadas em galpão aberto. Posteriormente, as túberas foram plantadas em canteiros para se avaliar a percentagem de emergência de plantas. O delineamento experimental empregado foi inteiramente casualizado com dez tratamentos, em quatro repetições. A unidade experimental constituiu-se de 20 túberas-semente. A baixa temperatura não induziu a emergência das túberas-semente do inhame em nenhum período de armazenamento, e aos 25 dias, ocorreu apodrecimento das mesmas. Aos 40 dias após o plantio verificou-se aumento na emergência das plantas, em túberas armazenadas durante dez e quinze dias em sacos de polietileno contendo carbureto de cálcio; este aumento foi de 35% no número de plantas emergidas em relação às túberas-semente acondicionadas em sacos sem carbureto de cálcio e de 38% em relação às túberas-semente armazenadas em galpão abertoTo evaluate the effect of low temperature and calcium carbide on the emergence of yam tuber-seeds, Da Costa cv., an experiment was carried out from October, 1998 to March, 1999, in Areia, Brazil. To evaluate the influence of the low temperature on the emergence of yam tuber-seeds, tubers were stored in cold chamber at 5ºC and relative humidity of 90% in four periods (10; 15; 20 and 25 days). To evaluate the efficiency of the calcium carbide on breaking dormancy of tubers, the same were conditioned in black polyethylene bags with calcium carbide in the proportion of 60 g/kg of roots and stored under conditions of open shed (temperature of 27ºC and humidity of 64%), in four periods (10; 15; 20 and 25 days). As control there were used tubers conditioned in bags of black polyethylene without calcium carbide and stored in open shed. Afterwards, tubers were planted in beds, to evaluate plant emergence. The experiment was laid out in complete randomized blocks with ten treatments and four replications. The experimental unit was constituted of 20 tuber-seeds. The low temperature didn't induce the emergence of yam tuber-seeds in any storage period, and at 25 days, tubers were rotten. At 40 days after planting date, higher emergence occurred in tubers stored in polyethylene bags containing calcium carbide during ten to fifteen days; this increase was of 35% in the number of emerged plants in relation to the tuber-seeds conditioned in bags without calcium carbide and of 38% in relation to the tuber-seeds stored under environmental conditions

Com o objetivo de avaliar o efeito da baixa temperatura e do carbureto de cálcio na emergência de túberas-semente de inhame, cultivar Da Costa, foi conduzido um experimento no período de outubro de 1998 a março de 1999, em Areia-PB. Para se avaliar a influência da baixa temperatura sobre a quebra de dormência das túberas-semente, as mesmas foram armazenadas em câmara fria à temperatura de 5ºC e umidade relativa de 90% em quatro períodos (10; 15; 20 e 25 dias). Para se avaliar a eficiência do carbureto de cálcio na quebra da dormência das túberas, as mesmas foram acondicionadas em sacos de polietileno preto com carbureto de cálcio na proporção de 60 g/kg de túberas e armazenadas em condições de galpão aberto (temperatura média de 27ºC e umidade de 64%), em quatro períodos (10; 15; 20 e 25 dias). Como testemunhas foram utilizadas túberas acondicionadas em sacos de polietileno sem carbureto de cálcio e túberas armazenadas em galpão aberto. Posteriormente, as túberas foram plantadas em canteiros para se avaliar a percentagem de emergência de plantas. O delineamento experimental empregado foi inteiramente casualizado com dez tratamentos, em quatro repetições. A unidade experimental constituiu-se de 20 túberas-semente. A baixa temperatura não induziu a emergência das túberas-semente do inhame em nenhum período de armazenamento, e aos 25 dias, ocorreu apodrecimento das mesmas. Aos 40 dias após o plantio verificou-se aumento na emergência das plantas, em túberas armazenadas durante dez e quinze dias em sacos de polietileno contendo carbureto de cálcio; este aumento foi de 35% no número de plantas emergidas em relação às túberas-semente acondicionadas em sacos sem carbureto de cálcio e de 38% em relação às túberas-semente armazenadas em galpão aberto To evaluate the effect of low temperature and calcium carbide on the emergence of yam tuber-seeds, Da Costa cv., an experiment was carried out from October, 1998 to March, 1999, in Areia, Brazil. To evaluate the influence of the low temperature on the emergence of yam tuber-seeds, tubers were stored in cold chamber at 5ºC and relative humidity of 90% in four periods (10; 15; 20 and 25 days). To evaluate the efficiency of the calcium carbide on breaking dormancy of tubers, the same were conditioned in black polyethylene bags with calcium carbide in the proportion of 60 g/kg of roots and stored under conditions of open shed (temperature of 27ºC and humidity of 64%), in four periods (10; 15; 20 and 25 days). As control there were used tubers conditioned in bags of black polyethylene without calcium carbide and stored in open shed. Afterwards, tubers were planted in beds, to evaluate plant emergence. The experiment was laid out in complete randomized blocks with ten treatments and four replications. The experimental unit was constituted of 20 tuber-seeds. The low temperature didn't induce the emergence of yam tuber-seeds in any storage period, and at 25 days, tubers were rotten. At 40 days after planting date, higher emergence occurred in tubers stored in polyethylene bags containing calcium carbide during ten to fifteen days; this increase was of 35% in the number of emerged plants in relation to the tuber-seeds conditioned in bags without calcium carbide and of 38% in relation to the tuber-seeds stored under environmental conditions