Vibration propagation in discrete element particle models of rock

Vibrations in rock masses can be a significant hazard, leading to human discomfort and structural damage. Recent cases of subway excavation or tunnel excavation near existing dams in Portugal have raised again the importance of this topic. Traditional statistical tools have been used to study wave propagation in rock, but fall short when rock fracturing or faulting radically changes the way vibration propagates. Numerical models such as finite-element or finite-difference models also have some insufficiencies, namely in the way discontinuities are represented. We propose the utilization of bonded particle models based on the Particle Discrete Element Method. Synthetic rock samples are generated and their static elastic properties are calibrated by manipulating micro-properties (assembly organization and normal and shear contact stiffness). The static and dynamic properties of the rock cores are tested and the complete elastic response of the model is evaluated and discussed

Larval susceptibility of Aedes aegypti and Culex quinquefasciatus populations to chemical insecticides

OBJECTIVE: To evaluate the susceptibility to chemical insecticides of Culex quinquefasciatus and Aedes aegypt larvae from areas subjected to control treatments or not. METHODS: Bioassays for diagnostic concentration and multiple concentration were performed for organophosphate and pyrethroid insecticides according to World Health Organization parameters. The susceptibility was assessed for mosquito larvae collected from an area not subjected to chemical control (Campinas, State of São Paulo, SP) and from other areas (Campo Grande, Mato Grosso do Sul, MS, and Cuiabá, Mato Grosso, MT), in Brazil, subjected to such treatments. RESULTS: Tests for Culex quinquefasciatus larvae from Campinas, SP, allowed suspicion of resistance to cypermethrin and gave evidence of resistance to cyfluthrin. Larvae of this species collected in Campo Grande, MS, and Campinas, SP, presented resistance to temephos. For the colony from the latter locality, the following resistance rates were established: RR50=6.36 and RR95=4.94, in relation to a standard susceptible strain. Moreover, tests for Aedes aegypti showed similar susceptibility to temephos for a field population from Cuiabá, MT, and a laboratory population. CONCLUSIONS: The results indicate resistance of Culex quinquefasciatus to organophosphate and pyrethroid insecticides and make evident the need for evaluation and monitoring of the efficiency of insecticides to be used in mosquito control programs.OBJETIVO: Avaliar a susceptibilidade a inseticidas químicos de larvas de Culex quinquefasciatus e Aedes aegypti, provenientes de áreas sujeitas ou não a tratamentos de controle. MÉTODOS: Foram coletadas larvas de mosquitos em uma área não sujeita a tratamentos com inseticidas (Campinas, SP) e em áreas sujeitas a esses tratamentos (Campo Grande, MS e Cuiabá, MT). Foram usados bioensaios com concentrações diagnóstico e concentrações múltipla de inseticidas organofosforados e piretróides, segundo padrão da Organização Mundial de Saúde, para avaliar a susceptibilidade dessas larvas. RESULTADOS: Ensaios com larvas de Culex quinquefasciatus de Campinas, SP, permitiram a suspeita de resistência à cipermetrina e evidenciaram resistência à ciflutrina. Larvas dessa espécie coletadas em Campo Grande, MS, e Campinas, SP, apresentaram resistência ao temephos. Para a colônia campineira desta espécie, foram estabelecidas as razões de resistência: RR50=6,36 e RR95=4,94, com base em linhagem susceptível padrão. Adicionalmente, os testes com Aedes aegypti mostraram susceptibilidade similar ao temephos em uma população de campo (Cuiabá, MT) e uma de laboratório. CONCLUSÕES: Os resultados indicam resistência a organofosforado e piretróides em Culex quinquefasciatus, evidenciando a necessidade de avaliações e monitoramento da efetividade dos inseticidas a serem usados nos programas de controle de mosquitos

BRS Mandobi: A New Forage Peanut Cultivar Propagated by Seeds for the Tropics

Forage peanut (Arachis pintoi) is a forage legume of relatively recent use in beef and dairy cattle feeding. Although it is native exclusively to Brazil, the first cultivar, Amarillo, was released in Australia in 1987. Forage peanut has a great number of favourable attributes for establishing grass-legume mixtures, which guarantee the persistence and high yields of high quality forage in cultivated pastures. Therefore, studies with this species have intensified in many tropical regions of the world (Assis and Valentim 2009). In the state of Acre, western Brazilian Amazon, 137,000 ha are cultivated with forage peanut, cv. Belmonte, benefiting thousands of producers, with annual economic impact of USD $46 M (Embrapa 2012). Social and environmental impacts resulting from the use of this legume are also highly positive. However, despite the success achieved in mixed pastures with forage peanut, expansion of the area sown has been relatively slow because vegetative propagation using stolons is labour intensive and requires large quantities of limited vegetative material. In Brazil, Embrapa has co-ordinated the development of new forage peanut cultivars and their evaluation in different biomes. The objective of this paper is to present a new cultivar of seed propagated forage peanut, developed for use in tropical regions, by Embrapa in partnership with Unipasto (Association for Promotion of Breeding Research in Tropical Forage)

3-(2,4-Dibromo­anilino)-2,2-dimethyl-2,3-dihydro­naphtho[1,2-b]furan-4,5-dione: a new substituted aryl­amino nor-β-lapachone derivative

The title compound, C20H15Br2NO3, shows the furan ring to adopt a half-chair conformation and the two ring systems to be approximately perpendicular [dihedral angle = 71.0 (2)°]. In the crystal structure, inter­molecular C—H⋯O contacts link the mol­ecules

Selecting New \u3cem\u3eBrachiaria humidicola\u3c/em\u3e Hybrids for Western Brazilian Amazon

Brachiaria humidicola is a perennial and stoloniferous forage grass, with excellent adaptation to infertile soils and waterlogging. Producers in northern Brazil have become interested in this species, especially after the degradation of large areas of lowly permeable soils sown with B. brizantha cv. Marandu, which is highly intolerant of soil waterlogging (Andrade and Valentim 2006). However, since only 3 cultivars of B. humidicola are registered in Brazil (Mapa 2013), there is a need to develop new cultivars adapted to the range of environmental conditions experienced. Recently, Embrapa Beef Cattle obtained intraspecific hybrids of B. humidicola that need to be evaluated agronomically, aiming at subsequent grazing trials and future releases. The objective of this study was to evaluate and select apomictic and sexual hybrids of B. humidicola in the environmental conditions of the state of Acre, in western Brazilian Amazon

Both XPA and DNA polymerase eta are necessary for the repair of doxorubicin-induced DNA lesions

Doxorubicin (DOX) is an important tumor chemotherapeutic agent, acting mainly by genotoxic action. This work focus on cell processes that help cell survival, after DOX-induced DNA damage. in fact, cells deficient for XPA or DNA polymerase eta (pol eta, XPV) proteins (involved in distinct DNA repair pathways) are highly DOX-sensitive. Moreover, LY294002, an inhibitor of PIKK kinases, showed a synergistic killing effect in cells deficient in these proteins, with a strong induction of G2/M cell cycle arrest. Taken together, these results indicate that XPA and pol eta proteins participate in cell resistance to DOX-treatment, and kinase inhibitors can selectively enhance its killing effects, probably reducing the cell ability to recover from breaks induced in DNA. (C) 2011 Elsevier Ireland Ltd. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)USP-COFECUB (São Paulo, Brazil)Univ São Paulo, Dept Microbiol, Inst Biomed Sci, São Paulo, BrazilUniv Paris Sud, Inst Gustave Roussy, Ctr Natl Rech Sci, UMR8200, Villejuif, FranceFed Univ São Paulo UNIFESP, Dept Biol Sci, Diadema, SP, BrazilUniv Fed Rio Grande do Sul, Ctr Biotechnol, Dept Biophys, Porto Alegre, RS, BrazilFed Univ Hlth Sci Porto Alegre UFCSPA, Dept Basic Hlth Sci, Porto Alegre, RS, BrazilFed Univ São Paulo UNIFESP, Dept Biol Sci, Diadema, SP, BrazilWeb of Scienc