Leaf water potential and osmotic adjustment as physiological traits to improve drought tolerance in rice

A sample of recombinant inbred lines (RILs) was derived from a bi-parental cross between Lemont and BK88-BR6, which contrasted in maintenance of leaf water potential (LWP) and expression of osmotic adjustment (OA). Genotypic variation for LWP and OA, and their associations with yield determination under water deficit, was studied in a series of five field experiments. Genotypic variation in the maintenance of high LWP was consistent across water deficit experiments. In the determination of genotypic variation in the maintenance of LWP, rate of water deficit was not an important factor influencing ranking, but degree of water deficit, and phenological development stage were important, particularly around heading. Genotypic variation in expression of OA was also observed under water deficits during both vegetative and flowering stages but ranking was inconsistent across experiments. This was in part because of large experimental errors associated with its measurement, but also because the expression of OA was associated with extent of decline of LWP. The relationship between OA and LWP was demonstrated when data were combined across experiments for vegetative and flowering stages. Under water-limited conditions around flowering, grain yield reduction was mainly due to a increased spikelet sterility. Variation in OA was not related to grain yield nor yield components. There were however, negative phenotypic and genetic correlations between LWP and percentage spikelet sterility measured at flowering stage on panicles at the same development stage during a water deficit treatment. This suggests that traits contributing to the maintenance of high LWP minimized the effects of water deficit on spikelet sterility and consequently grain yield. (C) 2002 Elsevier Science B.V. All rights reserved.

Adolescents' perceptions of differential parenting: Links with attachment style and adolescent adjustment

The study examines whether adolescent twins' attachment style mediates the association between their perceptions of differential parental treatment and their reported adjustment. Data from a survey of 174 adolescent twins are used to assess the links between twins' reports of differential parental affection and differential parental control, their attachment style, and their reported personal self-esteem, social self-esteem, and anxiety. Twins' reports of having been disfavored in comparison with their co-twin were associated with attachment insecurity, anxiety, and lower personal self-esteem. Attachment was found to mediate the association between the twins' reports of differential parental affection and their reported anxiety and personal self-esteem. The strongest evidence for mediation was found for twins' reports of differential maternal affection in predicting adolescent twins' anxiety.

Postpartum issues' for expectant mothers and fathers

Objective: To investigate the postpartum psychosocial and infant care topics that women and men who attend preparation for parenthood classes have been thinking or worrying about during the pregnancy. Furthermore, to compare the rates of endorsement of such issues for women and men so that clinicians can use this information to help plan which topics to include in preparation for parenthood classes. Design: A survey of expectant parents attending preparation for parenthood classes at a local public hospital. Participants completed a 17- to 19-item postpartum issues checklist devised for the study. Setting: Preparation for parenthood classes conducted in a public hospital in South Western Sydney, Australia. Participants: People attending the session were in their 2nd to 3rd trimester, of low to middle socioeconomic status, and 95% were expecting their first child. Eighty-five percent of women were accompanied by their male partner at the session. Data are reported from 201 women and 182 men. Measure: A 17-item issues checklist was devised initially and later expanded to 19 items. The initial checklist covered three psychosocial issues: interpersonal, intrapersonal, and parental competency. The expanded checklist also included items on infant care issues. Participants rated each item as to the extent to which they had been thinking or worrying about it over the past few weeks. Results: More than half of the men and women had been thinking or worrying about their ability to cope as new parents; just less than half of both men and women endorsed the item regarding the effect having a baby would have on their relationship with their partner; approximately 40% of women had thought that they might get bored or lonely when at home with the baby, and an equal rate of men reported that their partner experiencing this sense of boredom or loneliness was an issue for them. There were few differences between the genders in the rate of endorsement on the issues checklist. Conclusion: That many of the issues on the checklist are prevalent in both women and men at this time in the pregnancy would suggest that these are topics that would be pertinent for inclusion at preparation for parenthood classes. Although the checklist is not exhaustive, the data reported give empirical justification for inclusion of these topics in such classes.

Composition and energy density of eggs from two species of freshwater turtle with twofold ranges in egg size

Lipid, protein, ash, carbohydrate and water content and energy density of eggs were measured from different clutches over a range of egg size in two species of freshwater turtle. Dry egg contents consisted of protein (54-60%), lipid (25-31%) and ash (5-6%) while carbohydrate was found to be negligible (

Molecular and functional analyses of Kunjin virus infectious cDNA clones demonstrate the essential roles for NS2A in virus assembly and for a nonconservative residue in NS3 in RNA replication

A number of full-length cDNA clones of Kunjin virus (KUN) were previously prepared; it was shown that two of them, pAKUN and FLSDX, differed in specific infectivities of corresponding in vitro transcribed RNAs by similar to100,000-fold (A. A. Khromykh et al., J. Virol. 72:7270-7279, 1998). In this study, we analyzed a possible genetic determinant(s) of the observed differences in infectivity initially by sequencing the entire cDNAs of both clones and comparing them with the published sequence of the parental KUN strain MRM61C. We found six common amino acid residues in both cDNA clones that were different from those in the published MRM61C sequence but were similar to those in the published sequences of other flaviviruses from the same subgroup. pAKUN clone had four additional codon changes, i.e., Ile59 to Asn and Arg175 to Lys in NS2A and Tyr518 to His and Ser557 to Pro in NS3. Three of these substitutions except the previously shown marker mutation, Arg175 to Lys in NS2A, reverted to the wild-type sequence in the virus eventually recovered from pAKUN RNA-transfected BHK cells, demonstrating the functional importance of these residues in viral replication and/or viral assembly. Exchange of corresponding DNA fragments between pAKUN and FLSDX clones and site-directed mutagenesis revealed that the Tyr518-to-His mutation in NS3 was responsible for an similar to5-fold decrease in specific infectivity of transcribed RNA, while the Ile59-to-Asn mutation in NS2A completely blocked virus production. Correction of the Asn59 in pAKUN NS2A to the wild-type lie residue resulted in complete restoration of RNA infectivity. Replication of KUN replicon RNA with an Ile59-to-Asn substitution in NS2A and with a Ser557-to-Pro substitution in NS3 was not affected, while the Tyr518-to-His substitution in NS3 led to severe inhibition of RNA replication. The impaired function of the mutated NS2A in production of infectious virus was complemented in trans by the helper wild-type NS2A produced from the KUN replicon RNA. However, replicon RNA with mutated NS2A could not be packaged in trans by the KUN structural proteins. The data demonstrated essential roles for the KUN nonstructural protein NS2A in virus assembly and for NS3 in RNA replication and identified specific single-amino-acid residues involved in these functions.

Interspecific hybrids between the homothallic Phytophthora sojae and Phytophthora vignae

An interspecific cross was attempted between two homothallic species of Phytophthora, P. sojae and P. vignae. From 1640 single-oospore cultures isolated, DNA was extracted from 800, and two interspecific F-1 hybrids (F(1)1121 and F(1)1426) were putatively identified using RAPD markers. The true hybrid nature of these F-1 hybrids was confirmed using additional AFLP analysis. Single- zoospore cultures were generated for each F-1 hybrid and one single-zoospore culture of each was used in pathogenicity and virulence tests. Both F-1 hybrids were pathogenic to soybean and cowpea, causing symptoms including lesions, wilting and death of susceptible soybean and cowpea cultivars. However, the aggressiveness of the F-1 hybrids was reduced and was substantially more variable when compared with that of the parental isolates on their respective hosts. The F-1 hybrids were reisolated from infected seedlings and their hybrid nature confirmed using RAPD and AFLP analysis. These results provide a basis for further research aimed at obtaining an increased understanding of the genetics of host specificity in the Oomycetes.

Direction of Causation Modeling Between Cross-Sectional Measures of Parenting and Psychological Distress in Female Twins

Under certain conditions, cross-sectional analysis of cross-twin intertrait correlations can provide important information about the direction of causation (DOC) between two variables. A community-based sample of Australian female twins aged 18 to 45 years was mailed an extensive Health and Lifestyle Questionnaire (HLQ) that covered a wide range of personality and behavioral measures. Included were self-report measures of recent psychological distress and perceived childhood environment (PBI). Factor analysis of the PBI yielded three interpretable dimensions: Coldness, Overprotection, and Autonomy. Univariate analysis revealed that parental Overprotection and Autonomy were best explained by additive genetic, shared, and nonshared environmental effects (ACE), whereas the best-fitting model for PBI Coldness and the three measures of psychological distress (Depression, Phobic Anxiety, and Somatic Distress) included only additive genetic and nonshared environmental effects (AE). A common pathway model best explained the covariation between (1) the three PBI dimensions and (2) the three measures of psychological distress. DOC modeling between latent constructs of parenting and psychological distress revealed that a model which specified recollected parental behavior as the cause of psychological distress provided a better fit than a model which specified psychological distress as the cause of recollected parental behavior. Power analyses and limitations of the findings are discussed.

Escalation of Drug Use in Early-Onset Cannabis Users vs Co-twin Controls

Context Previous studies have reported that early initiation of cannabis (marijuana) use is a significant risk factor for other drug use and drug-related problems. Objective To examine whether the association between early cannabis use and subsequent progression to use of other drugs and drug abuse/dependence persists after controlling for genetic and shared environmental influences. Design Cross-sectional survey conducted in 1996-2000 among an Australian national volunteer sample of 311 young adult (median age, 30 years) monozygotic and dizygotic same-sex twin pairs discordant for early cannabis use (before age 17 years). Main Outcome Measures Self-reported subsequent nonmedical use of prescription sedatives, hallucinogens, cocaine/other stimulants, and opioids; abuse or dependence on these drugs (including cannabis abuse/dependence); and alcohol dependence. Results Individuals who used cannabis by age 17 years had odds of other drug use, alcohol dependence, and drug abuse/dependence that were 2.1 to 5.2 times higher than those of their co-twin, who did not use cannabis before age 17 years. Controlling for known risk factors (early-onset alcohol or tobacco use, parental conflict/separation, childhood sexual abuse, conduct disorder, major depression, and social anxiety) had only negligible effects on these results. These associations did not differ significantly between monozygotic and dizygotic twins. Conclusions Associations between early cannabis use and later drug use and abuse/dependence cannot solely be explained by common predisposing genetic or shared environmental factors. The association may arise from the effects of the peer and social context within which cannabis is used and obtained. In particular, early access to and use of cannabis may reduce perceived barriers against the use of other illegal drugs and provide access to these drugs.

Caenorhabditis elegans mutants resistant to phosphine toxicity show increased longevity and cross-resistance to the synergistic action of oxygen

Phosphine (hydrogen phosphide, PH3) is the fumigant most widely used to protect stored products from pest infestation. Despite the importance of this chemical, little is known about its mode of action. We have created three phosphine-resistant lines (pre-1, pre-7, pre-33) in the model organism C. elegans, with LC50 values 2, 5, and 9 times greater than the fully susceptible parental strain. Molecular oxygen was shown to be an extremely effective synergist with phosphine as, under hyperoxic conditions, 100% mortality was observed in wild-type nematodes exposed to 0.1 mg/l phosphine, a nonlethal concentration in air. All three mutants were resistant to the synergistic effects of oxygen in proportion to their resistance to phosphine with one mutant, pre-33, showing complete resistance to this synergism. We take the proportionality of cross-resistance between phosphine and the synergistic effect of oxygen to imply that all three mutants circumvent a mechanism of phosphine toxicity that is directly coupled to oxygen metabolism. Compared with the wild-type strain, all three mutants have an extended average life expectancy of from 12.5 to 25.3%. This is consistent with the proposed involvement of oxidative stress in both phosphine toxicity and ageing. Because the wild-type and mutant nematodes develop at the same rate, the longevity is unlikely to be caused by a clk-type reduction in oxidative metabolism, a potential alternative mechanism of phosphine resistance.

A genetic map of macadamia based on randomly amplified DNA fingerprinting (RAF) markers

The first genetic linkage map of macadamia (Macadamia integrifolia and M. tetraphylla) is presented. The map is based on 56 F-1 progeny of cultivars 'Keauhou' and 'A16'. Eighty-four percent of the 382 markers analysed segregated as Mendelian loci. The two-way pseudo-testcross mapping strategy allowed construction of separate parental cultivar maps. Ninety bridging loci enabled merging of these maps to produce a detailed genetic map of macadamia, 1100 cM in length and spanning 70-80% of the genome. The combined map comprised 24 linkage groups with 265 framework markers: 259 markers from randomly amplified DNA fingerprinting (RAF), five random amplified polymorphic DNA (RAPD), and one sequence-tagged microsatellite site (STMS). The RAF marker system unexpectedly revealed 16 codominant markers, one of them a putative microsatellite locus and exhibiting four distinct alleles in the cross. This molecular study is the most comprehensive examination to date of genetic loci of macadamia, and is a major step towards developing marker-assisted selection for this crop.

Pais adolescentes : vivência e significação

Foram investigadas mudanças ocorridas na vida de pais adolescentes e identificados os significados da paternidade e da maternidade para esses jovens. Oito participantes com idades de 16 a 21 anos foram entrevistados com base em roteiro focalizando: mudanças decorrentes da paternidade; significados da paternidade e da maternidade; práticas parentais. Entre as mudanças referidas destacaram-se a perda de liberdade e a inserção no mercado de trabalho. Para eles ser pai significa, principalmente, trabalhar para prover as necessidades da criança e também educar, dar carinho e atenção. A mãe é aquela que cuida e dá carinho, sacrifica-se e é a figura mais importante na vida da criança. As práticas parentais mais mencionadas estavam relacionadas com lazer e brincadeiras. Os dados indicaram a permanência de forte vínculo com os modelos tradicionais de parentalidade, embora tenham mostrado também a emergência de relações afetivas significativas entre pais e filhos.

Caracterização molecular de três espécies de Trachycephalus (Anura: Hylidae) : investigando potenciais híbridos interespecíficos

Animais híbridos representam um desafio à taxonomia e sistemática, pois correspondem a unidades evolutivas geralmente sem clara delimitação morfológica, comportamental e genética. Híbridos podem ser morfologicamente intermediários aos parentais ou, devido à introgressão e retrocruzamentos, suas características podem se misturar tornando difícil sua identificação. Uma das formas de identificação de híbridos é por meio de ferramentas de biologia molecular, que ao utilizarem marcadores de DNA mitocondrial (herança exclusiva materna) e DNA nuclear (herança materna e paterna), permitem a comparação entre informações genéticas. Além da hibridização existem outras fontes de conflito entre dados moleculares provenientes do DNA mitocondrial e DNA nuclear, como por exemplo a retenção de polimorfismos ancentrais. Em localidades do Espírito Santo, Brasil, foram coletados indivíduos de morfologia distinta de Trachycephalus mesophaeus e T. nigromaculatus, que são as únicas espécies do gênero conhecidas nesse estado. Porém, estudos piloto usando o gene mitocondrial Citocromo Oxidase subunidade I (COI) agruparam esses espécimes com amostras de T. typhonius. Devido a estas incongruências, foram sequenciados fragmentos de dois genes mitocondriais - COI e Nicotinamida Desidrogenase subunidade 2 (ND2) e um exon nuclear (tirosinase) de 173 indivíduos de Trachycephalus, de forma a esclarecer as identificações taxonômicas e investigar a correspondência entre caracteres morfológicos e genéticos nesta linhagem, na sua área de ocorrência As filogenias moleculares, divergências genéticas, redes de haplótipos e polimorfismos de nucleotídeos únicos (SNPs) confirmaram as três espécies acima mencionadas como linhagens evolutivas distintas e revelaram mais sete indivíduos potencialmente híbridos, mas morfologicamente assinalados a T. mesophaeus, T. nigromaculatus ou T. typhonius.. Devido à taxa de evolução lenta da tirosinase, as espécies mais recentes T. typhonius e T. nigromaculatus parecem não terem sido sorteadas completamente nesse gene. Já T. mesophaeus, que é a espécie mais antiga das três, foi recuperada inequivocamente em todas as análises. De forma inédita, as análises moleculares evidenciaram a ocorrência de introgressão bidirecional entre T. nigromaculatus e T. typhonius e entre T. nigromaculatus e T. mesophaeus, sendo que há indícios de indivíduos F1 (cruzamentos entre espécies parentais puras gerando híbridos). A utilização do gene ND2 mostrou-se mais eficiente do que o gene COI nas filogenias e, apesar da tirosinase ser um gene nuclear de evolução lenta, contribuiu para a identificação de incongruências citonucleares. Nossos resultados mostram que a história filogenética de Trachycephalus é complexa e que o uso de marcadores nucleares de evolução mais rápida e ampliação dessas análises para outras espécies do gênero podem revelar mais eventos de hibridização.

Intervenção nas práticas parentais num grupo de cuidadores

A Formação Parental, enquanto medida de intervenção socioeducativa, tem sido um alvo de interesse gradual, quer a nível internacional, quer a nível nacional. As profundas mudanças ocorridas, na esfera social e familiar, são agentes que têm vindo a promover o desenvolvimento de iniciativas de intervenção neste domínio. A consciência dos desafios que acarretam o desempenho das funções parentais nos dias de hoje, tem sido um incentivo na procura de respostas e auxílio aos intervenientes neste difícil processo de educar. Também o contributo teórico da Psicologia, nomeadamente nas áreas de estudo sobre a Formação Parental, a família, os estilos parentais, o envolvimento parental, e a sua pertinência para o desenvolvimento e equilíbrio infanto-juvenil, têm vindo e estimular o crescente investimento nesta área de intervenção. O presente estudo teve por objetivo construir, implementar e avaliar a eficácia de um programa de Promoção de Práticas Educativas Parentais. Neste estudo participaram 4 cuidadores (3 do sexo feminino e 1 um do sexo masculino), todos eles residentes no meio urbano (n=4), casados (n=4) e com uma média de idades de aproximadamente 42 anos (M=42,25), variando entre os 40 e os 45 anos. A maioria tem o 12º ano (n=3, 75%), apenas 1 (25%), possui habilitações superiores ao nível de licenciatura. Os dados foram recolhidos através de um Questionário Sociodemográfico e do Questionário de Práticas Parentais (Versão Portuguesa de M. Gaspar & P. Santos de 2008, revisto em 2013). No que respeita aos resultados obtidos, existem algumas modificações positivas na promoção de competências parentais ajustada, recorrendo à utilização de estratégias de disciplina positiva em todos os sujeitos, depois da intervenção. Referente as outras variáveis, nomeadamente, os diferentes estilos de disciplina, promoção do autoconhecimento enquanto pessoas e pais, fomentar a autoestima atendendo a aspetos pessoas e parentais, incentivar o bem-estar subjetivo/felicidade dos participantes com relevância na parentalidade não houve ocorrência de alterações positivas.

Criatividade e estilos parentais em crianças do 4º ano de escolaridade

RESUMO: A História demonstra que a criatividade tem sido uma constante da actividade humana constituindo-se como o motor da vida de qualquer comunidade (Urban, 1996). Diversas pesquisas em Psicologia demonstram a importância da interacção parental e dos estilos educativos utilizados pelos pais no desenvolvimento das crianças (Darling, 1999). Os estilos parentais exercem uma influência importante na expressão da criatividade das crianças, tendo as famílias um papel fundamental no desenvolvimento dessas capacidades criativas (Wu, 2008). Esta investigação pretende estudar a relação entre a criatividade e os estilos parentais em crianças do 4º ano de escolaridade, esperando-se que crianças submetidas a um estilo parental autoritário apresentem níveis inferiores de criatividade. A amostra é constituída por 236 alunos com idades compreendidas entre os 8-12 anos. Na avaliação da criatividade foi utilizado o TCT-DP (Test for Creative Thinking – Drawing Production) de Urban e Jellen (1986) e na avaliação dos estilos parentais foi aplicado o API (Índice de Parentalidade Autorizado) de C. Jackson, L. Henriksen e V. Foshee (1998), adaptado para a população portuguesa por M. Gaspar e M. Alarcão em 2003. Foi ainda aplicado o questionário sócio-demográfico. Verificou-se que não existem diferenças estatisticamente significativas entre os níveis de criatividade em função dos estilos parentais considerados, não confirmando a hipótese colocada. ABSTRACT: History shows that creativity has been a constant of human activity constituting itself as the engine of life of any community (Urban, 1996). Several studies in psychology show the importance of parental interaction and the educational practices used by parents on children's development (Darling, 1999). Parenting styles are considered to be an important influence on the expression of creativity of children, and the families have a fundamental role in the development of these creative abilities (Wu, 2008). This research aims to study the relationship between creativity and parenting styles in children of fourth grade, it is expected that children under an authoritarian parenting style have lower levels of creativity. The sample comprises 236 students aged between 8-12 years. In the assessment of creativity was used TCT-DP (Test for Creative Thinking - Drawing Production) by Urban and Jellen (1986) and in the assessment of parenting style was applied the API Index (Authoritative Parenting Index) of C. Jackson, L. Henriksen and V. Foshee (1998), adapted to portuguese sample by M. Gaspar and M. Alarcão in 2003. It was also applied the socio-demographic questionnaire. It wasn’t found any statistically significant differences between the levels of creativity considering the parenting styles studied, not confirming the hypothesis.

Aproveitar a vida, juventude e gravidez

Este artigo propõe demonstrar que a concepção de aproveitar a vida tem significados importantes no universo investigado. A expressão surgiu no contexto de uma pesquisa de abordagem qualitativa, realizada em Pelotas, durante os anos de 2001-2002, com 23 jovens de 18-19 anos que já tinham filho(s) e com 10 de suas mães. O objetivo inicial do estudo era compreender o contexto da gravidez na adolescência em jovens das camadas popular e média, pertencentes a um estudo de coorte de nascimento/1982. Durante o trabalho de campo, o conceito de aproveitar a vida ganhou grande destaque nas narrativas, ajudou a qualificar, classificar e, principalmente, justificar os comportamentos afetivo-sexuais juvenis. As análises demonstram que a juventude deve se posicionar na vida de uma forma proveitosa, endossando positivamente os seus valores sociais. A gravidez das jovens, para as mães, é vista como um dos efeitos da inconseqüência e da modernidade e, para as jovens da camada popular, como algo que estava previsto, favorecendo o menor controle parental. Para as jovens da camada média, a gravidez interrompe temporariamente ou inverte planos de trabalho e estudo, e afeta menos a sociabilidade das jovens, pois estas contam com maior estrutura econômica e familiar para seguir curtindo a vida.