The effectiveness of mutation operation in the case of Estimation of Distribution Algorithms

The Estimation of Distribution Algorithms are a class of evolutionary algorithms which adopt probabilistic models to reproduce individuals in the next generation, instead of conventional crossover and mutation operators. In this paper, mutation operators are incorporated into Estimation of Distribution Algorithms in order to maintain the diversities in EDA populations. Two kinds of mutation operators are examined: a bitwise mutation operator and a mutation operator taking account into the probabilistic model. In experiments, we do not only compare the proposed methods with conventional EDAs on a few fitness functions but also analyze sampled probabilistic models by using KL-divergence. The experimental results shown in this paper elucidate that the mutation operator taking account into the probabilistic model improve the search ability of EDAs.     

Studies directed towards a mechanistic evaluation of inactivation of aromatase by the suicide substrates androsta-1,4-diene-3,17-diones and its 6-ene derivatives aromatase inactivation by the 19-substituted derivatives and their enzymic aromatization

To gain insight into the mechanistic features for aromatase inactivation by the typical suicide substrates, androsta-1,4-diene-3,17-dione (ADD, 1) and its 6-ene derivative 2, we synthesized 19-substituted (methyl and halogeno) ADD and 1,4,6-triene derivatives 8 and 10 along with 4,6-diene derivatives 9 and tested for their ability to inhibit aromatase in human placental microsomes as well as their ability to serve as a substrate for the enzyme. 19-Methyl-substituted steroids were the most powerful competitive inhibitors of aromatase (K_i: 8.2–40 nM) in each series. Among the 19-substituted inhibitors examined, 19-chloro-ADD and its 6-ene derivatives (7b and 9b) inactivated aromatase in a time-dependent manner in the presence of NADPH in air while the other ones did not. The time-dependent inactivation was blocked by the substrate AD and required NADPH. Only the time-dependent inactivators 7b and 9b in series of 1,4-diene and 1,4,6-triene steroids as well as all of 4,6-diene steroids 9, except for the methyl compound 9a, served as a substrate for aromatase to yield estradiol and/or its 6-ene estradiol with lower conversion rates compared to the corresponding parent steroids 1,4-diene, 1,4,6-triene and 4,6-diene derivatives. The present findings strongly suggest that the aromatase reaction, 19-oxygenation, at least in part, would be involved in the time-dependent inactivation of aromatase by the suicide substrates 1 and 2, where the 19-substitutent would play a critical role in the aromatase reaction probably though steric and electronic reasons.     

Surface modification of bacterial cellulose nanofibers for property enhancement of optically transparent composites: dependence on acetyl-group DS

Bacterial cellulose (BC) nanofibers were acetylated to enhance the properties of optically transparent composites of acrylic resin reinforced with the nanofibers. A series of BC nanofibers acetylated from degree-of-substitution (DS) 0 to 1.76 were obtained. X-ray diffraction profiles indicated that acetylation proceeded from the surface to the core of BC nanofibers, and scanning electron microscopy images showed that the volume of nanofibers increases by the bulky acetyl group. Since acetylation decreased the refractive index of cellulose, regular transmittance of composites comprised of 63% BC nanofiber was improved, and deterioration at 580 nm because of fiber reinforcement was suppressed to only 3.4%. Acetylation of nanofibers changed their surface properties and reduced the moisture content of the composite to about one-third that of untreated composite, although excessive acetylation increased hygroscopicity. Furthermore, acetylation was found to reduce the coefficient of thermal expansion of a BC sheet from 3 x 10(-6) to below 1 x 10(-6) 1/K.     

A wheat homolog of MOTHER OF FT AND TFL1 acts in the regulation of germination

Seed dormancy is an adaptive mechanism and an important agronomic trait. Temperature during seed development strongly affects seed dormancy in wheat (Triticum aestivum) with lower temperatures producing higher levels of seed dormancy. To identify genes important for seed dormancy, we used a wheat microarray to analyze gene expression in embryos from mature seeds grown at lower and higher temperatures. We found that a wheat homolog of MOTHER OF FT AND TFL1 (MFT) was upregulated after physiological maturity in dormant seeds grown at the lower temperature. In situ hybridization analysis indicated that MFT was exclusively expressed in the scutellum and coleorhiza. Mapping analysis showed that MFT on chromosome 3A (MFT-3A) colocalized with the seed dormancy quantitative trait locus (QTL) QPhs.ocs-3A.1. MFT-3A expression levels in a dormant cultivar used for the detection of the QTL were higher after physiological maturity; this increased expression correlated with a single nucleotide polymorphism in the promoter region. In a complementation analysis, high levels of MFT expression were correlated with a low germination index in T1 seeds. Furthermore, precocious germination of isolated immature embryos was suppressed by transient introduction of MFT driven by the maize (Zea mays) ubiquitin promoter. Taken together, these results suggest that MFT plays an important role in the regulation of germination in wheat.     

Engagement of overexpressed Her2 with GEP100 induces autonomous invasive activities and provides a biomarker for metastases of lung adenocarcinoma

Overexpression of Her2/ErbB2/Neu in cancer is often correlated with recurrent distant metastasis, although the mechanism still remains largely elusive. We have previously shown that EGFR, when tyrosine-phosphorylated, binds to GEP100/BRAG2 to activate Arf6, which induces cancer invasion and metastasis. We now show that overexpressed Her2 in lung adenocarcinoma cells also employs GEP100. Like EGFR-GEP100 binding, this association is primarily mediated by the pleckstrin homology (PH) domain of GEP100 and Tyr1139/Tyr1196 of Her2. Tyr1139/Tyr1196 are autonomously phosphorylated, when Her2 is overexpressed. Accordingly, invasive activities mediated by the Her2-GEP100 pathway are not dependent on external factors. Blocking Her2-GEP100 binding, as well as its signaling pathway all inhibit cancer invasive activities. Moreover, our clinical study indicates that co-overexpression of Her2 with GEP100 in primary lung adenocarcinomas of patients is correlated with the presence of their node-metastasis with a statistical significance. Since the GEP100 PH domain interacts with both Her2 and EGFR, targeting this domain may provide novel cancer therapeutics.     

Spatiotemporal occurrence and feeding habits of tonguefish,Cynoglossus lighti Norman, 1925, larvae in Ariake Bay,Japan

Spatiotemporal occurrence and feeding habits of tonguefish (Cynoglossus lighti Norman, 1925) larvae were investigated in an offshore area (>5 m in depth) of the inner part of Ariake Bay, Japan. All specimens were symmetric, free‐swimming larvae. Although their seasonal abundance and distribution in the study site varied from year to year, spawning started in June and the larval abundance was high in August and September with a wide distribution in the inner part of the bay. Both present and previous study results strongly suggest that larvae may settle primarily in the estuary and near‐shore areas of Ariake Bay after their wide distribution in the offshore area of the bay during the free‐swimming stage. Larvae showed a clear feeding rhythm in which they fed on prey mainly during the daytime. Larvae fed exclusively on copepods, and identified prey were mostly Paracalanidae (mainly Parvocalanus crassirostris), Microsetella norvegica, and Oithona davisae. Pre‐metamorphosis larvae fed primarily on Paracalanidae and O. davisae, whereas O. davisae formed a smaller proportion of the early‐metamorphosis diet. In early metamorphoses, larvae fed preferentially on Paracalanidae and M. norvegica.     

A Metaphosphate-dependent Nicotinamide Adenine Dinucleotide Kinase from Brevibacterium ammoniagenes

The enzyme utilizing metaphosphate for nicotinamide adenine dinucleotide phosphorylation was purified 500-fold from B. ammoniagenes and its properties were studied. The isolated enzyme appeared homogeneous on disc gel electrophoresis; its molecular weight was determined to be 9.0 × 10⁴ by gel filtration. This enzyme specifically phosphorylated nicotinamide adenine dinucleotide at the optimum pH at 6.0. Of phosphoryl donors tested, metaphosphate was most effective for the reaction, and adenosine-5′-triphosphate was less effective. The activity was inhibited by adenosine-5′-monophosphate, adenosine-5′-diphosphate or reduced pyridine nucleotides. The enzyme did not exhibit catalytic activity in the absence of a divalent cation. We concluded that the enzyme phosphorylating nicotinamide adenine dinucleotide in the presence of metaphosphate is distinct from adenosine-5′-triphosphate-dependent nicotinamide adenine dinucleotide kinase, and tentatively designated it metaphosphate-dependent nicotinamide adenine dinucleotide kinase.     

Left and Right Lung Asynchrony as a Physiological Indicator for Unilateral Bronchial Obstruction in Interventional Bronchoscopy

Background

In patients with bronchial obstruction, pulmonary function tests may not change significantly after intervention. The airflow asynchrony in both lungs due to unilateral bronchial obstruction may be applicable as a physiological indicator. The airflow asynchrony is reflected by the difference in the left and right lung sound development at tidal breathing.

Objectives

To investigate the usefulness of left and right lung asynchrony due to unilateral bronchial obstruction as a physiological indicator for interventional bronchoscopy.

Methods

Fifty cases with central airway obstruction were classified into three groups: tracheal, bronchial and extensive obstruction. The gap index was defined as the absolute value of the average of gaps between the left and right lung sound intensity peaks for a 12-second duration.

Results

Before interventional bronchoscopy, the gap index was significantly higher in the bronchial (p<0.05) and extensive obstruction groups (p<0.05) than in the tracheal group. The gap index in cases with unilateral bronchial obstruction of at least 80% (0.18±0.04 seconds) was significantly higher than in cases with less than 80% obstruction (0.02±0.01 seconds, p<0.05). After intervention for bronchial obstruction, the dyspnea scale (p<0.001) and gap index significantly improved (p<0.05), although no significant improvements were found in spirometric assessments. The responder rates for dyspnea were 79.3% for gap indexes over 0.06 seconds and 55.6% for gap indexes of 0.06 seconds or under.

Conclusions

Assessment of left and right lung asynchrony in central airway obstruction with bronchial involvement may provide useful physiological information for interventional bronchoscopy.