Interior and exterior functions of positive Boolean functions

The interior and exterior functions of a Boolean function f were introduced in Makino and Ibaraki (Discrete Appl. Math. 69 (1996) 209–231), as stability (or robustness) measures of the f. In this paper, we investigate the complexity of two problems -INTERIOR and -EXTERIOR, introduced therein. We first answer the question about the complexity of -INTERIOR left open in Makino and Ibaraki (Discrete Appl. Math. 69 (1996) 209–231); it has no polynomial total time algorithm even if is bounded by a constant, unless P=NP. However, for positive h-term DNF functions with h bounded by a constant, problems -INTERIOR and -EXTERIOR can be solved in (input) polynomial time and polynomial delay, respectively. Furthermore, for positive k-DNF functions, -INTERIOR for two cases in which k=1, and and k are both bounded by a constant, can be solved in polynomial delay and in polynomial time, respectively.     

Hydrolysis of Diazonium Salts Using a Two‐Phase System (CPME and Water)

A new method for the hydrolysis of diazonium salts, without the formation of tar, was developed. A two‐phase system consisting of cyclopentyl methyl ether (CPME) and water is very effective for the hydrolysis of diazonium salts. Using this solvent system, the diazonium salt prepared from 3‐(4‐nitrophenoxy)aniline gave 3‐(4‐nitrophenoxy)phenol in high yield (96%) within 20 min. The synthesized phenol is an industrially important raw material in polymer syntheses. Furthermore, the use of the present two‐phase system of CPME and water successfully brought about the efficient conversions of several m‐substituted anilines into the corresponding m‐substituted phenols. This is the first example of hydrolysis of diazonium salts using the two‐phase system (CPME and water).     

Analysis of Nitrification in Agricultural Soil and Improvement of Nitrogen Circulation with Autotrophic Ammonia-Oxidizing Bacteria

Accumulations of inorganic nitrogen (NH₄ ⁺, NO₂ ^?, and NO₃ ^?) were analyzed to evaluate the nitrogen circulation activity in 76 agricultural soils. Accumulation of NH₄ ⁺ was observed, and the reaction of NH₄ ⁺?→?NO₂ ^? appeared to be slower than that of NO₂ ^??→?NO₃ ^? in agricultural soil. Two autotrophic and five heterotrophic ammonia-oxidizing bacteria (AOB) were isolated and identified from the soils, and the ammonia-oxidizing activities of the autotrophic AOB were 1.0?×?10³–1.0?×?10⁶ times higher than those of heterotrophic AOB. The relationship between AOB number, soil bacterial number, and ammonia-oxidizing activity was investigated with 30 agricultural soils. The ratio of autotrophic AOB number was 0.00032–0.26 % of the total soil bacterial number. The soil samples rich in autotrophic AOB (>1.0?×?10⁴ cells/g soil) had a high nitrogen circulation activity, and additionally, the nitrogen circulation in the agricultural soil was improved by controlling the autotrophic AOBs.     

Distribution of Hydrocarbon-Degrading Bacteria in the Soil Environment and Their Contribution to Bioremediation

A real-time PCR quantification method for indigenous hydrocarbon-degrading bacteria (HDB) carrying the alkB gene in the soil environment was developed to investigate their distribution in soil. The detection limit of indigenous HDB by the method was 1?×?10⁶ cells/g-soil. The indigenous HDB were widely distributed throughout the soil environment and ranged from 3.7?×?10⁷ to 5.0?×?10⁸ cells/g-soil, and the ratio to total bacteria was 0.1–4.3 %. The dynamics of total bacteria, indigenous HDB, and Rhodococcus erythropolis NDKK6 (carrying alkB R2) during bioremediation were analyzed. During bioremediation with an inorganic nutrient treatment, the numbers of these bacteria were slightly increased. The numbers of HDB (both indigenous bacteria and strain NDKK6) were gradually decreased from the middle stage of bioremediation. Meanwhile, the numbers of these bacteria were highly increased and were maintained during bioremediation with an organic nutrient. The organic treatment led to activation of not only the soil bacteria but also the HDB, so an efficient bioremediation was carried out.     

Mesomorphic properties of troponoid esters and amides with cholest-5-ene-3β-carboxylic acid moiety

Troponoid esters and amides connected with cholest-5-ene-3β-carboxylic acid have been synthesized to characterize their mesomorphic properties and to compare them with those of the corresponding benzenoids. 5-Alkoxytroponyl esters and amides with a long alkoxy group exhibited a twist grain boundary A* phase, as well as chiral nematic and smectic A* (SmA*) phases. The corresponding benzenoid esters exhibit SmA* and blue phases and the benzenoid amides only a SmA* phase. The differences between the mesomorphic properties are discussed in terms of the structural features of the core.     

The vehicle routing problem with flexible time windows and traveling times

We generalize the standard vehicle routing problem by allowing soft time window and soft traveling time constraints, where both constraints are treated as cost functions. With the proposed generalization, the problem becomes very general. In our algorithm, we use local search to determine the routes of vehicles. After fixing the route of each vehicle, we must determine the optimal start times of services at visited customers. We show that this subproblem is NP-hard when cost functions are general, but can be efficiently solved with dynamic programming when traveling time cost functions are convex even if time window cost functions are non-convex. We deal with the latter situation in the developed iterated local search algorithm. Finally we report computational results on benchmark instances, and confirm the benefits of the proposed generalization.     

Kinetic resolution of d,l-myo-inositol derivatives catalyzed by chiral Cu(II) complex

Kinetic resolution of d,l-myo-inositol derivatives having a 1,2-diol functionality by monobenzoylation was achieved using (R,R)-Ph-BOX-Cu(II) as a catalyst. The monobenzoylation preferentially took place at the 1,2-diol functionality via a highly enantiodiscriminatory process, which was largely influenced by a substituent at the position adjacent to the 1,2-diol functionality. This method was applied to a synthesis of biologically important d-inositol-1-phosphate.     

Synthesis and physical properties of negative thermal expansion materials Zr1−xMxW2O8−y (M=Sc, In, Y) substituted for Zr(IV) sites by M(III) ions

Zr_1−xM_xW₂O_8−y (M=Sc, In and Y) solid solutions substituted up to x=0.04 for Zr(IV) sites by M(III) ions were synthesized by a solid-state reaction. X-ray diffraction experiments from 90 to 560 K revealed that all solid solutions had a cubic crystal structure and showed negative thermal expansion coefficients. The lattice parameters of Zr_1−xM_xW₂O_8−y were smaller than that of ZrW₂O₈ probably due to oxygen defects, though the ionic radii of substituted M³⁺ ions were larger than that of Zr⁴⁺. Order-disorder phase transition temperatures of the substituted samples drastically decreased in the order of Y, In and Sc compared to the percolation theory, and decreased with increasing M content.     

Inorganic arsenic: A dangerous enigma for mankind

Human being have been using inorganic arsenic for a long time. Many reports on arsenic poisoning have been published: eg case reports, examination reports, post mortem reports, and epidemiological studies. Several aspects and features of arsenic poisoning are discussed in this report. Methods of inferring arsenic-related disease, disease classification according to acute or chronic criteria, exposure route, interaction, confounding factors, and the oxidation state of arsenic are all discussed. The effects of arsenic are classified into skin, respiratory system, gastrointestinal tract, liver, cardiovascular system, nervous system, and bone marrow effects. Carcinogenicity is an important chronic effect of arsenic poisoning, so special attention is paid to it in this review. In Japan, there have been many incidents of arsenic poisoning. In this review, we often use data from these cases, such as the Morinaga powdered-milk poisoning case, the Ube soy-sauce poisoning case, the Toroku mine incident, and the Nakajo well-water poisoning case. We emphasize here the necessity of planning follow-up studies and total health care for patients exposed to arsenic.     

Structural concept of nitroxide as a lipid peroxidation inhibitor

Nitroxides have antioxidative activities toward lipid peroxidation, but the influence of steric factors is not known. We synthesized alkyl-substituted nitroxides at the α-position of the N-O moiety to enhance lipophilicity and the bulk effect. There was good correlation between the IC(50) and lipophilicity (log P(o/w)) of nitroxides with use of the thiobarbituric acid-reactive substances (TBARS) assay. Furthermore, an inhibitory effect on the TBARS assay was dependent upon the number and length of alkyl groups, though nitroxides had almost identical lipophilicity.