This study examined parental functioning, parental satisfaction, and concern for offspring during their child's military service, among war veterans, some of whom suffered from acute combat-induced stress reaction (CSR) and posttraumatic stress disorder (PTSD). In addition, we examined the additive and interactive contributions of CSR, PTSD and attachment dimensions to parenting measures. The sample consisted of 477 participants divided into two groups: a clinical group of veterans who had been diagnosed with CSR on the battlefield (N = 267), and a matched control group of veterans who did not suffer from CSR (NCSR; N = 210). CSR, PTSD, avoidant-attachment, and anxious-attachment, were all related to lower levels of parental functioning and satisfaction. Veterans who suffered from both CSR and PTSD reported more concern for their offspring during their child's military service compared to veterans with PTSD but without antecedent CSR. Attachment dimensions and specifically attachment-avoidance, made the greatest contribution to parenting measures, followed by posttraumatic symptoms. In addition, attachment-avoidance moderated the relationship between posttraumatic symptoms and parental functioning. Theoretical and clinical implications of these results are discussed.

Ethylene-inducing xylanase (EIX) elicits plant defense responses in certain tobacco (Nicotiana tabacum) and tomato cultivars in addition to its xylan degradation activity. It is not clear, however, whether elicitation occurs by cell wall fragments released by the enzymatic activity or by the xylanase protein interacting directly with the plant cells. We cloned the gene encoding EIX protein and overexpressed it in insect cells. To determine the relationship between the two activities, substitution of amino acids in the xylanase active site was performed. Substitution at glutamic acid-86 or -177 with glutamine (Gln), aspartic acid (Asp), or glycine (Gly) inhibited the ␤-1-4-endoxylanase activity. Mutants having Asp-86 or Gln-177 also lost the ability to induce the hypersensitive response and ethylene biosynthesis. However, mutants having Gln-86, Gly-86, Asp-177, or Gly-177 retained ability to induce ethylene biosynthesis and the hypersensitive response. Our data show that the xylanase activity of EIX elicitor can be separated from the elicitation process, as some of the mutants lack the former but retain the latter.

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Past experience of gas production from methane-hydrate-bearing sediments indicates that sand migration is a major factor restricting the production of gas from methane-hydrate reservoirs. One important geotechnical aspect of sand migration is the influence of grain detachment on the existing stresses. This paper focuses on understanding and quantifying the nature of this aspect using different approaches, with a focus on discrete element method (DEM) simulations of sand detachment from hydrate-bearing sand samples. The investigation in the paper reveals that sand migration affects isotropic and deviatoric stresses differently. In addition, the existence of hydrate moderates the magnitude of stress relaxation. Both of these features are currently missing from continuum-based models, and therefore, a new constitutive model for stress relaxation is suggested, incorporating the research findings. Model parameters are suggested based on the DEM simulations. The model is suitable for continuum mechanics-based simulations of gas production from hydrate reservoirs.

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