Crystallization behavior of poly(lactide)/poly(β-hydroxybutyrate)/talc composites.

The authors thank Dr. Patrice Lefrançois (CNAM) for SEM observations. They are also grateful to Pr. Jack R. Plimmer USDA, Agricultural Research Service, USA for his discussions during this work.The morphology and miscibility of commercial poly(lactide) (PLA)/poly(b-hydroxybutyrate) (PHB, from 5 to 20 wt %) blends prepared by melt extrusion method, were investigated using differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR) observations. The results show that for all the studied blend contents, PLA/PHB blends are immiscible. The effects of PHB and talc on the nonisothermal cold crystallization kinetics of PLA were examined using a differential scanning calorimetry (DSC) at different heating rates. PHB acted as a nucleating agent on PLA and the addition of talc to the blend yielded further improve-ment, since significant increase in the enthalpy peak was observed for samples containing 10 wt % PHB and talc (from 0.5 to 5 phr). The crystallization kinetics were then examined using the Avrami–Jeziorny and Liu–Mo approach. The simultaneous presence of PHB and talc induced a decrease of the crystallization half time. The evolution of activation energies determined with Kissinger’s equation suggests that blending with PHB and incorporating talc promote nonisothermal cold crystallization of PLA. The synergistic nucleating effect of PHB and talc was also observed on isothermal crystallization of PLA from the melt

Justification Patterns for OWL DL Ontologies

For debugging OWL-DL ontologies, natural language explanations of inconsistencies and undesirable entailments are of great help. From such explanations, ontology developers can learn why an ontology gives rise to specific entailments. Unfortunately, commonly used tableaux-based reasoning services do not provide a basis for such explanations, since they rely on a refutation proof strategy and normalising transformations that are difficult for human ontology editors to understand. For this reason, we investigate the use of automatically generated justifications for entailments (i.e., minimal sets of axioms from the ontology that cause entailments to hold). We show that such justifications fall into a manageable number of patterns, which can be used as a basis for generating natural language explanations by associating each justification pattern with a rhetorical pattern in natural language

SPR-5; MET-2 maternal reprogramming cooperates with the Dream Complex to regulate developmental cell fates

Histone methylation is a post-transcriptional modification to the N-terminal tails of histone core proteins that regulates DNA accessibility, and consequently, gene expression. Like DNA, histone methylation can be inherited between generations, and is highly regulated during embryonic development. At fertilization, histone methylation must undergo maternal reprogramming to reset the epigenetic landscape in the new zygote. During maternal reprogramming of histone methylation in the nematode, C. elegans, H3K4me (a modification associated with active transcription) is removed by the H3K4 demethylase, SPR-5, and H3K9me (a modification associated with transcriptional repression) is subsequently added by the histone methyltransferase, MET-2. Recently, it was demonstrated that SPR-5; MET-2 maternal reprogramming antagonizes the H3K36 methyltransferase, MES-4, which maintains a transcriptional memory of a subset of germline genes between generations. Maternal loss of SPR-5 and MET-2 results in ectopic expression of MES-4 germline genes in somatic tissues and a severe developmental delay. Recently, exciting new literature suggest that the DREAM Complex, a transcriptional repressor complex that regulates cell cycle, also represses MES-4 germline genes in somatic tissues suggesting that the DREAM Complex and SPR-5; MET-2 maternal reprogramming may work together to prevent ectopic germline gene expression in somatic tissues and developmental delay. To test this hypothesis, we knocked down Dream Complex members LIN-35 and LIN-9 in spr-5; met-2 mutants using RNA interference (RNAi). We found that loss of either LIN-35 or LIN-9 exacerbates the severe developmental delay that we normally observe in spr-5; met-2 mutants leading to a complete larval arrest. These findings suggest that the Dream Complex and SPR-5; MET-2 maternal reprogramming work together to ensure proper development and provide insight into how an evolutionary conserved transcriptional repressor complex cooperates with maternal reprogramming of histone methylation to regulate germline versus somatic cell fates

Measuring the understandability of deduction rules for OWL

Debugging OWL ontologies can be aided with automated reasoners that generate entailments, including undesirable ones. This information is, however, only useful if developers understand why the entailments hold. To support domain experts (with limited knowledge of OWL), we are developing a system that explains, in English, why an entailment follows from an ontology. In planning such explanations, our system starts from a justification of the entailment and constructs a proof tree including intermediate statements that link the justification to the entailment. Proof trees are constructed from a set of intuitively plausible deduction rules. We here report on a study in which we collected empirical frequency data on the understandability of the deduction rules, resulting in a facility index for each rule. This measure forms the basis for making a principled choice among alternative explanations, and identifying steps in the explanation that are likely to require extra elucidation

"Evaluation of high-dose estrogen and high-dose estrogen plus methyltestosterone treatment on cognitive task performance in postmenopausal women"

Amy B. Wisniewski is an Assistant Professor of Biology at Drake University, Des Moines, Iowa. She can be contacted at [email protected]: To investigate the cognitive effects of high-dose oral estrogen alone or in combination with oral methyltestosterone in postmenopausal women. Methods: Participants were tested with a randomized, double-blind design on the Identical Pictures, Cube Comparisons, Building Memory and Shape Memory tasks before and after 4 months of hormone treatment. Results: Women receiving estrogen and methyltestosterone maintained a steady level of performance on the Building Memory task, whereas those receiving estrogen alone showed a decrease in performance. Conclusions: These results indicate that the addition of testosterone to high-dose estrogen replacement exerts a protective effect on memory performance in postmenopausal women. Copyright © 2002 S. Karger AG, Basel.Portions of this manuscript were presented at the 1999 Endocrine Society Meeting, San Diego, Calif., USA and the 1999 North American Menopause Society Meeting, New York, N.Y., USA This research was partially supported by the Johns Hopkins University School of Medicine General Clinical Research Center, NIH/NCRR grant M01 RR00052. This research was also funded in part by Solvay Pharmaceuticals, Inc., Marietta, Ga., USA

Implementing the Clean Development Mechanism in Vietnam: potential and limitations

The Clean Development Mechanism (CDM) in Vietnam is used way below its full potential. In spite of efforts to further CDM projects in the recent years, Vietnam still lags behind the comparable neighboring countries in term of registered CDM projects. Especially, though 2008 and 2009 have seen a fast growth in the pipeline in the country but only 14 projects were registered as at 2 December 2009. This development progress is low to the country's greater potential and makes it as a late starter on the global CDM rise when the window of opportunity created by the first Kyoto Protocol period has almost closed. This paper analyzes the barriers explaining this late start and slow catch-up. It suggests strategic policy recommendations which could increase the attractiveness of investment business in the context of climate change protection in Vietnam

Improving the Clean Development Mechanism Post-2012: A Developing Country Perspective

International audienceIn this article, we assess the future prospects of the Clean Development Mechanism (CDM) from the perspective of a developing country, drawing on Vietnam as a case study. First, we review the performance of the CDM and describe the evolution of carbon markets on the path towards a post-2012 climate regime. Next, we place Vietnam in a post-2012 context, and assess potential project resources, challenges, and opportunities that could arise for the country from a future climate policy framework. Our analysis suggests that the CDM should remain in place and be improved to facilitate more meaningful participation by developing countries in climate mitigation efforts beyond 2012. Finally, the article sets out eight proposals that could help improve the CDM as the world progresses towards a new international climate policy framework

Planning accessible explanations for entailments in OWL ontologies

A useful enhancement of an NLG system for verbalising ontologies would be a module capable of explaining undesired entailments of the axioms encoded by the developer. This task raises interesting issues of content planning. One approach, useful as a baseline, is simply to list the subset of axioms relevant to inferring the entailment; however, in many cases it will still not be obvious, even to OWL experts, why the entailment follows. We suggest an approach in which further statements are added in order to construct a proof tree, with every step based on a relatively simple deduction rule of known difficulty; we also describe an empirical study through which the difficulty of these simple deduction patterns has been measured

Reverberation Chamber Uniformity Validation and Radiated Susceptibility Test Procedures for the NASA High Intensity Radiated Fields Laboratory

The NASA Langley Research Center's High Intensity Radiated Fields Laboratory has developed a capability based on the RTCA/DO-160F Section 20 guidelines for radiated electromagnetic susceptibility testing in reverberation chambers. Phase 1 of the test procedure utilizes mode-tuned stirrer techniques and E-field probe measurements to validate chamber uniformity, determines chamber loading effects, and defines a radiated susceptibility test process. The test procedure is segmented into numbered operations that are largely software controlled. This document is intended as a laboratory test reference and includes diagrams of test setups, equipment lists, as well as test results and analysis. Phase 2 of development is discussed