106 research outputs found

    Identificação e caracterização molecular de genes envolvidos no metabolismo de diterpenos específicos do cafeeiro.

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    Apesar de pouco estudado, os lipĂ­deos do cafĂ© desempenham papel importante na qualidade da bebida e do aroma. Cerca de dez a vinte por cento da fração lipĂ­dica do cafĂ© corresponde a diterpenos que alĂ©m da provĂĄvel relação com a qualidade tambĂ©m estĂŁo relacionados com a questĂŁo do cafĂ© e a saĂșde. As espĂ©cies de Coffea sĂŁo as Ășnicas capazes de sintetizar os diterpenos cafestol, caveol e seus compostos derivados (16-O-metilcafestol, 16-O-metilcaveol). Visando um entendimento maior dos genes envolvidos na formação dos diterpenos de cafĂ©, foi realizado um estudo in silico da expressĂŁo de trĂȘs genes que codificam para as primeiras etapas da sua via de biossĂ­ntese ? copalil difosfato sintase (CPS), caureno sintase (KS) e caureno oxidase (KO). Posteriormente foi feita uma anĂĄlise da expressĂŁo destes genes durante o desenvolvimento de frutos de Coffea arabica cv. IAPAR 59 e Coffea canephora cv. ApoatĂŁ. Este estudo permitiu a identificação de um gene para a CPS e KS e dois para a KO. A anĂĄlise in silico revelou nĂ­veis e perfis de expressĂŁo especĂ­ficos para cada gene. Os resultados obtidos in vivo apresentaram algumas diferenças dos dados obtidos in silico, e a comparação de C. arabica e C. canephora tambĂ©m revelou perfis de expressĂŁo diferentes para os genes estudados. Esses dados serĂŁo confirmados por RT-PCR e um estudo geral do transcriptoma, usando macroarranjos desenvolvidos a partir do Projeto Genoma CafĂ©, serĂĄ iniciado para identificar os outros genes envolvidos nessa via metabĂłlica.Biotecnologia aplicada Ă  cadeia agroindustrial do cafĂ©

    An international comparison of adolescent non-suicidal self-injury (NSSI) and suicide attempts: Germany and the USA

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    Background This study examined the prevalence of non-suicidal self-injury (NSSI), suicide attempts, suicide threats and suicidal ideation in a German school sample and compared the rates with a similar sample of adolescents from the midwestern USA by using cross-nationally validated assessment tools. Method Data were provided from 665 adolescents (mean age 14.8 years, s.d.=0.66, range 14-17 years) in a school setting. Students completed the Self-Harm Behavior Questionnaire (SHBQ), the Ottawa Self-Injury Inventory (OSI) and a German version of the Center for Epidemiological Studies-Depression Scale (CES-D). Results A quarter of the participants (25.6%) endorsed at least one act of NSSI in their life, and 9.5% of those students answered that they had hurt themselves repetitively (more than four times). Forty-three (6.5%) of the students reported a history of a suicide attempt. No statistically significant differences were observed between the German and US samples in terms of self-injury or suicidal behaviors. Conclusions By using the same validated assessment tools, no differences were found in the prevalence and characteristics of self-injury and suicidal behaviors between adolescents from Germany and the USA. Thus, it seems that NSSI has to be understood as worldwide phenomenon, at least in Western culture

    Second-order symmetric duality with cone constraints

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    AbstractWolfe and Mond–Weir type second-order symmetric duals are formulated and appropriate duality theorems are established under η-bonvexity/η-pseudobonvexity assumptions. This formulation removes several omissions in an earlier second-order primal dual pair introduced by Devi [Symmetric duality for nonlinear programming problems involving η-bonvex functions, European J. Oper. Res. 104 (1998) 615–621]

    Organophosphorus poisoning in animals and enzymatic antidotes

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    © 2018 Springer-Verlag GmbH Germany, part of Springer Nature Organophosphorus compounds (OPs) are neurotoxic molecules developed as pesticides and chemical warfare nerve agents (CWNAs). Most of them are covalent inhibitors of acetylcholinesterase (AChE), a key enzyme in nervous systems, and are therefore responsible for numerous poisonings around the world. Many animal models have been studied over the years in order to decipher the toxicity of OPs and to provide insights for therapeutic and decontamination purposes. Environmental impact on wild animal species has been analyzed to understand the consequences of OP uses in agriculture. In complement, various laboratory models, from invertebrates to aquatic organisms, rodents and primates, have been chosen to study chronic and acute toxicity as well as neurobehavioral impact, immune response, developmental disruption, and other pathological signs. Several decontamination approaches were developed to counteract the poisoning effects of OPs. Among these, enzyme-based strategies are particularly attractive as they allow efficient external decontamination without toxicity or environmental impact and may be of interest for treatment. Approaches using bioscavengers for prophylaxis, treatment, and external decontamination are emphasized and their potential is discussed in the light of toxicological observations from various animal models. The relevance of animal models, regarding their cholinergic system and the abundance of naturally protecting enzymes, is also discussed for better extrapolation of results to human

    Nonsuicidal self-injury: a rapidly evolving global field

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    Autoinducers act as biological timers in Vibrio harveyi

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    Quorum sensing regulates cell density-dependent phenotypes and involves the synthesis, excretion and detection of so-called autoinducers. Vibrio harveyi strain ATCC BAA-1116 (recently reclassified as Vibrio campbellii), one of the best-characterized model organisms for the study of quorum sensing, produces and responds to three autoinducers. HAI-1, AI-2 and CAI-1 are recognized by different receptors, but all information is channeled into the same signaling cascade, which controls a specific set of genes. Here we examine temporal variations of availability and concentration of the three autoinducers in V. harveyi, and monitor the phenotypes they regulate, from the early exponential to the stationary growth phase in liquid culture. Specifically, the exponential growth phase is characterized by an increase in AI-2 and the induction of bioluminescence, while HAI-1 and CAI-1 are undetectable prior to the late exponential growth phase. CAI-1 activity reaches its maximum upon entry into stationary phase, while molar concentrations of AI-2 and HAI-1 become approximately equal. Similarly, autoinducer-dependent exoproteolytic activity increases at the transition into stationary phase. These findings are reflected in temporal alterations in expression of the luxR gene that encodes the master regulator LuxR, and of four autoinducer-regulated genes during growth. Moreover, in vitro phosphorylation assays reveal a tight correlation between the HAI-1/AI-2 ratio as input and levels of receptor-mediated phosphorylation of LuxU as output. Our study supports a model in which the combinations of autoinducers available, rather than cell density per se, determine the timing of various processes in V. harveyi populations

    Why alternative teenagers self-harm: exploring the link between non-suicidal self-injury, attempted suicide and adolescent identity

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    Background: The term ‘self-harm’ encompasses both attempted suicide and non-suicidal self-injury (NSSI). Specific adolescent subpopulations such as ethnic or sexual minorities, and more controversially, those who identify as ‘Alternative’ (Goth, Emo) have been proposed as being more likely to self-harm, while other groups such as ‘Jocks’ are linked with protective coping behaviours (for example exercise). NSSI has autonomic (it reduces negative emotions) and social (it communicates distress or facilitates group ‘bonding’) functions. This study explores the links between such aspects of self-harm, primarily NSSI, and youth subculture.<p></p> Methods: An anonymous survey was carried out of 452 15 year old German school students. Measures included: identification with different youth cultures, i.e. Alternative (Goth, Emo, Punk), Nerd (academic) or Jock (athletic); social background, e.g. socioeconomic status; and experience of victimisation. Self-harm (suicide and NSSI) was assessed using Self-harm Behavior Questionnaire and the Functional Assessment of Self-Mutilation (FASM).<p></p> Results: An “Alternative” identity was directly (r ≈ 0.3) and a “Jock” identity inversely (r ≈ -0.1) correlated with self-harm. “Alternative” teenagers self-injured more frequently (NSSI 45.5% vs. 18.8%), repeatedly self-injured, and were 4–8 times more likely to attempt suicide (even after adjusting for social background) than their non-Alternative peers. They were also more likely to self-injure for autonomic, communicative and social reasons than other adolescents.<p></p> Conclusions: About half of ‘Alternative’ adolescents’ self-injure, primarily to regulate emotions and communicate distress. However, a minority self-injure to reinforce their group identity, i.e. ‘To feel more a part of a group’

    Metabolic Adaptation of Ralstonia solanacearum during Plant Infection: A Methionine Biosynthesis Case Study

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    MetE and MetH are two distinct enzymes that catalyze a similar biochemical reaction during the last step of methionine biosynthesis, MetH being a cobalamin-dependent enzyme whereas MetE activity is cobalamin-independent. In this work, we show that the last step of methionine synthesis in the plant pathogen Ralstonia solanacearum is under the transcriptional control of the master pathogenicity regulator HrpG. This control is exerted essentially on metE expression through the intermediate regulator MetR. Expression of metE is strongly and specifically induced in the presence of plant cells in a hrpG- and metR-dependent manner. metE and metR mutants are not auxotrophic for methionine and not affected for growth inside the plant but produce significantly reduced disease symptoms on tomato whereas disruption of metH has no impact on pathogenicity. The finding that the pathogen preferentially induces metE expression rather than metH in the presence of plant cells is indicative of a probable metabolic adaptation to physiological host conditions since this induction of metE occurs in an environment in which cobalamin, the required co-factor for MetH, is absent. It also shows that MetE and MetH are not functionally redundant and are deployed during specific stages of the bacteria lifecycle, the expression of metE and metH being controlled by multiple and distinct signals

    International prevalence of adolescent non-suicidal self-injury and deliberate self-harm

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    <p>Abstract</p> <p>Background</p> <p>The behaviours of non-suicidal self-injury (NSSI) and deliberate self-harm (DSH) are prevalent among adolescents, and an increase of rates in recent years has been postulated. There is a lack of studies to support this postulation, and comparing prevalence across studies and nations is complicated due to substantial differences in the methodology and nomenclature of existing research.</p> <p>Methods</p> <p>We conducted a systematic review of current (2005 - 2011) empirical studies reporting on the prevalence of NSSI and DSH in adolescent samples across the globe.</p> <p>Results</p> <p>Fifty-two studies fulfilling the inclusion criteria were obtained for analysis. No statistically significant differences were found between NSSI (18.0% SD = 7.3) and DSH (16.1% SD = 11.6) studies. Assessment using single item questions led to lower prevalence rates than assessment with specific behaviour checklists. Mean prevalence rates have not increased in the past five years, suggesting stabilization.</p> <p>Conclusion</p> <p>NSSI and DSH have a comparable prevalence in studies with adolescents from different countries. The field would benefit from adopting a common approach to assessment to aide cross-cultural study and comparisons.</p
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