586 research outputs found

    Approximation error model (AEM) approach with hybrid methods in the forward-inverse analysis of the transesterification reaction in 3D-microreactors

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    This work advances the approximation error model approach for the inverse analysis of the biodiesel synthesis using soybean oil and methanol in 3D-microreactors. Two hybrid numerical-analytical approaches of reduced computational cost are considered to offer an approximate forward problem solution for a three-dimensional nonlinear coupled diffusive-convective-reactive model. First, the Generalized Integral Transform Technique (GITT) is applied using approximate non-converged solutions of the 3D model, by adopting low truncation orders in the eigenfunction expansions. Second, the Coupled Integral Equations Approach (CIEA) provides a reduced mathematical model for the average concentrations, which leads to inherently approximate solutions. The AEM approach through the Bayesian framework is illustrated in the simultaneous estimation of kinetic and diffusion coefficients of the transesterification reaction. For this purpose, the fully converged GITT results with higher truncation orders for the 3D partial differential model are employed as reference results to define the approximations errors. The results highlight that either the non-converged solutions via GITT or the reduced model solution obtained via CIEA, when taking into account the model error, are robust and cost-effective alternatives for the inverse analysis of nonlinear convection–diffusion-reaction problems

    Correlates of in-law conflict and intimate partner violence against chinese pregnant women in Hong Kong

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    This study examines correlates of in-law conflict with intimate partner violence (IPV) against pregnant women in a cohort of Chinese pregnant women who visited antenatal clinics in Hong Kong. This was a territory-wide, cross-sectional study of 3,245 pregnant women recruited from seven hospitals in Hong Kong. Participants were invited to complete the Chinese Abuse Assessment Screen and a demographic questionnaire. About 9% of the pregnant women reported having been abused by their partners in the preceding year. In-law conflict was the characteristic most significantly associated with preceding-year abuse against pregnant women, after controlling for covariates. Findings underscore the need to obtain information on in-law conflict as a risk factor for IPV. In-law conflict should be included in the assessment of risk for IPV. For the prevention of IPV, family-based intervention is needed to work with victims as well as in-laws. © 2009 Sage Publications.postprin

    Violence against pregnant women can increase the risk of child abuse: A longitudinal study

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    Objective: To assess the impact of intimate partner violence (IPV) against pregnant women on subsequent perpetration of child abuse and neglect (CAN) by parents; and to test the mediation effect of recent IPV on the link between IPV during pregnancy and subsequent CAN. Methods: This study was a longitudinal follow-up of a population-based study on pregnancy IPV conducted in antenatal clinics in 7 public hospitals in Hong Kong in 2005. Of all participants in the 2005 study, we recruited 487 women (with 184 having reported pregnancy IPV in the 2005 study) with newborn babies for a follow-up telephone interview in 2008. Participants responded to the Abuse Assessment Screen (AAS), the Parent-Child Conflict Tactics Scale, and some questions assessing demographic information. Results: The most common form of physical violence was corporal punishment, with a prevalence rate of 75.1% in the preceding year and 75.4% over their lifetime. Physical maltreatment was less likely to be reported, accounting for 4.7% in the preceding year and 4.9% over their lifetime. The preceding-year and lifetime prevalence rates of neglect were 11.3% and 11.5%, respectively. Findings from logistic regression analyses showed that IPV experienced by participants during pregnancy was associated with greater odds of both lifetime (aOR. =. 1.74) and preceding-year child physical maltreatment (aOR. =. 1.78). Results of the regression analyses also provided supportive evidence for the mediation effect of recent IPV victimization on the relationship between IPV during pregnancy and recent CAN against children. Conclusion: IPV against women during pregnancy predicted subsequent CAN on newborns in Chinese populations. This underscores the importance of screening pregnant women for IPV in order to prevent CAN at an early stage. Home visitations are suggested to break the cycle of violence within a nuclear family. © 2012 Elsevier Ltd.postprin

    Associating pregnancy with partner violence against Chinese women

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    The present study discusses if pregnancy is a risk factor for intimate partner violence using a large, representative sample containing detailed information on partner violence including physical and sexual abuse as well as perpetrator-related risk factors. Data from a representative sample of 2,225 men were analyzed. The self-reported prevalence of men's violence against their female partners was computed and compared in terms of demographic, behavioral, and relationship characteristics. The preceding-year prevalence of physical assault, sexual violence, and "any violence or injury" among the group whose partners were pregnant was 11.9%, 9.1%, and 18.8%, respectively. This is significantly higher than the nonpregnant group. Pregnancy was significantly associated with increased odds of violence, including physical assault, sexual violence, and "any violence or injury" (ORs = 2.42, 2.42, and 2.60, respectively). Having controlled for relationship characteristics including social desirability, social support, in-law conflict, dominance, and jealousy of male perpetrators, pregnancy was significantly associated with "any violence or injury." Demographic and behavioral variables accounted for pregnant women's significantly higher odds of having been abused in the year preceding the data collection. This study provides preliminary findings on the association between pregnancy and partner violence. Our findings underscore the need to screen for violence among pregnant women in clinical health care settings as well as in communities. Perpetrator-related risk factors should be included in the assessment of risk for partner violence against pregnant women. For the prevention of intimate partner violence, family-based intervention is needed to work with victims as well as perpetrators. © The Author(s) 2011.postprin

    Psychological intimate partner abuse among Chinese women: What we know and what we still need to know

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    Although increasing attention has been given to psychological abuse in intimate partner relationships, relatively little is known about this complex problem among Chinese women. A better understanding of psychological abuse in Chinese intimate relationships is warranted because Chinese culture is shame-oriented. Women, therefore, may be more susceptible to shameful feelings induced by psychological abuse. This may explain why psychological abuse, in the absence of physical and/or sexual abuse, has such adverse mental health effects on Chinese women. In this paper, what is known about psychological abuse in Chinese intimate relationships and what still needs to be known are highlighted, together with the mental health impact. Implications for future research are also presented.published_or_final_versio

    DNA demethylases target promoter transposable elements to positively regulate stress responsive genes in Arabidopsis

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    © 2014 Le et al. Background: DNA demethylases regulate DNA methylation levels in eukaryotes. Arabidopsis encodes four DNA demethylases, DEMETER (DME), REPRESSOR OF SILENCING 1 (ROS1), DEMETER-LIKE 2 (DML2), and DML3. While DME is involved in maternal specific gene expression during seed development, the biological function of the remaining DNA demethylases remains unclear. Results: We show that ROS1, DML2, and DML3 play a role in fungal disease resistance in Arabidopsis. A triple DNA demethylase mutant, rdd (ros1 dml2 dml3), shows increased susceptibility to the fungal pathogen Fusarium oxysporum. We identify 348 genes differentially expressed in rdd relative to wild type, and a significant proportion of these genes are downregulated in rdd and have functions in stress response, suggesting that DNA demethylases maintain or positively regulate the expression of stress response genes required for F. oxysporum resistance. The rdd-downregulated stress response genes are enriched for short transposable element sequences in their promoters. Many of these transposable elements and their surrounding sequences show localized DNA methylation changes in rdd, and a general reduction in CHH methylation, suggesting that RNA-directed DNA methylation (RdDM), responsible for CHH methylation, may participate in DNA demethylase-mediated regulation of stress response genes. Many of the rdd-downregulated stress response genes are downregulated in the RdDM mutants nrpd1 and nrpe1, and the RdDM mutants nrpe1 and ago4 show enhanced susceptibility to F. oxysporum infection. Conclusions: Our results suggest that a primary function of DNA demethylases in plants is to regulate the expression of stress response genes by targeting promoter transposable element sequences

    Estimation of hydraulic conductivity and its uncertainty from grain-size data using GLUE and artificial neural networks

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    peer reviewedaudience: researcher, professionalVarious approaches exist to relate saturated hydraulic conductivity (Ks) to grain-size data. Most methods use a single grain-size parameter and hence omit the information encompassed by the entire grain-size distribution. This study compares two data-driven modelling methods, i.e.multiple linear regression and artificial neural networks, that use the entire grain-size distribution data as input for Ks prediction. Besides the predictive capacity of the methods, the uncertainty associated with the model predictions is also evaluated, since such information is important for stochastic groundwater flow and contaminant transport modelling. Artificial neural networks (ANNs) are combined with a generalized likelihood uncertainty estimation (GLUE) approach to predict Ks from grain-size data. The resulting GLUE-ANN hydraulic conductivity predictions and associated uncertainty estimates are compared with those obtained from the multiple linear regression models by a leave-one-out cross-validation. The GLUE-ANN ensemble prediction proved to be slightly better than multiple linear regression. The prediction uncertainty, however, was reduced by half an order of magnitude on average, and decreased at most by an order of magnitude. This demonstrates that the proposed method outperforms classical data-driven modelling techniques. Moreover, a comparison with methods from literature demonstrates the importance of site specific calibration. The dataset used for this purpose originates mainly from unconsolidated sandy sediments of the Neogene aquifer, northern Belgium. The proposed predictive models are developed for 173 grain-size -Ks pairs. Finally, an application with the optimized models is presented for a borehole lacking Ks data

    Agrobacterium rhizogenes-Mediated Transformation of the Parasitic Plant Phtheirospermum japonicum

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    Background: Plants within the Orobanchaceae are an agriculturally important group of parasites that attack economically important crops to obtain water and nutrients from their hosts. Despite their agricultural importance, molecular mechanisms of the parasitism are poorly understood. Methodology/Principal Findings: We developed transient and stable transformation systems for Phtheirospermum japonicum, a facultative parasitic plant in the Orobanchaceae. The transformation protocol was established by a combination of sonication and acetosyringone treatments using the hairy-root-inducing bacterium, Agrobacterium rhizogenes and young seedlings. Transgenic hairy roots of P. japonicum were obtained from cotyledons 2 to 3 weeks after A. rhizogenes inoculation. The presence and the expression of transgenes in P. japonicum were verified by genomic PCR, Southern blot and RT-PCR methods. Transgenic roots derived from A. rhizogenes-mediated transformation were able to develop haustoria on rice and maize roots. Transgenic roots also formed apparently competent haustoria in response to 2,6dimethoxy-1,4-benzoquinone (DMBQ), a haustorium-inducing chemical. Using this system, we introduced a reporter gene with a Cyclin B1 promoter into P. japonicum, and visualized cell division during haustorium formation. Conclusions: We provide an easy and efficient method for hairy-root transformation of P. japonicum. Transgenic marker analysis revealed that cell divisions during haustorium development occur 24 h after DMBQ treatment. The protocol
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