Minimizing crossings in hierarchical digraphs with a hybridized genetic algorithm

Producing clear and intelligible layouts of hierarchical digraphs knows a renewed interest in information visualization. Recent experimental results show that metaheuristics are well-adapted methods for this problem. In this paper, we develop a new Hybridized Genetic Algorithm for arc crossing minimization. It follows the basic scheme of a GA with two major differences: problem-based crossovers adapted from ordering GAs are combined with a local search strategy based on averaging heuristics. Computational testing was performed on a set of 180 random hierarchical digraphs of standard sizes with various structures. Results show that the Hybridized Genetic Algorithm significantly outperforms Tabu Search—which is one of the best known methods for this problem- and also a multi-start descent except for highly connected graphs.     

Maternal obesity does not influence human milk protein 15N natural isotope abundance

ABSTRACT

Obesity increases protein metabolism with a potential effect on nitrogen isotope fractionation. The aim of this study was to test the influence of obesity on human milk extracted protein ¹⁵N natural isotope abundance (NIA) at one month post-partum and to compare human milk extracted protein ¹⁵N NIA and bulk infant hair ¹⁵N NIA. This cross-sectional observational study involved 16 obese mothers (body mass index (BMI)?≥?30?kg?m^?2 before pregnancy) matched with 16 normal-weight mothers (18.5?kg?m^?2?≤?BMI?<?25?kg?m^?2) for age and pregnancy characteristics. Human milk extracted protein and bulk infant hair ¹⁵N NIA were determined by isotope ratio monitoring by mass spectrometry interfaced to an elemental analyser (IRM-EA/MS). No significant difference was found in human milk protein ¹⁵N NIA values between obese and normal-weight mothers (8.93?±?0.48?‰ vs. 8.95?±?0.27?‰). However, human milk protein ¹⁵N NIA was significantly lower than bulk infant hair ¹⁵N NIA: 8.94?±?0.38?‰ vs. 9.66?±?0.69?‰, respectively. On the basis of these results, it is concluded that human milk protein ¹⁵N NIA measured at one month post-partum is not influenced by maternal obesity. These findings suggest that ¹⁵N NIA may be exploited to study metabolism without considering maternal obesity as a confounder.     

Vertical distribution characteristics of PM in the surface layer of Guangzhou

Measurements of particulate matter(PM),i.e.,PM10,PM2.5,and PMl,have been performed on the Canton Tower,a landmark building in Guangzhou,at heights of 121 and 454 m since November 2010,using a GRIMM 180 aerosol particle spectrometer(Germany).Analyses of data from November 2010 to May2013 showed that the annual average values of PM10,PM2.5,and PMl at the observation height of 121 m above the ground were 44.1,38.2,and 34.9μg/m3,respectively,and those at 454 m above the ground were 35.7,30.4,and 27.5 μg/m3,respectively.By considering the values of the secondary concentration limits given in the Ambient Air Quality Standards issued in 2012,it was observed that the annual average values of PM10 at the observation heights of 121 and 454 m,as well as those of PM2.5 at 454 m,reached those standards.Furthermore,the over-standard amplitude of the annual average value of PM2.5 at the observation height of 121 m was 9.1%.During the observation period,the maximum daily average values of PM10,PM2.5,and PM1 at the observation height of 121 m were 183.3,144.8,and 123.8 μg/m~3,respectively,and those at 454 m were 102.8,92.7,and 86.4 μg/m3.The daily average values of PM 10 at the observation height of 454 m were not above the standards.The over-standard frequencies of the daily average values of PM10 and PM2.5 at the observation height of 121 m were 0.6%and 10.7%,respectively,and the over-standard amplitudes were 9.0%and 24.4%,respectively.The over-standard frequency of the daily average value of PM2.5 at the observation height of 454 m was 2.0%,and the over-standard amplitude was 10.4%.Accordingly,it can be stated that the air at the observation height 454 m above the ground did not reach the secondary limit of the new standards.The pollution was most serious during winter,and the air was relatively cleaner during summer.Overall,the vertical distributions of PM 10,PM2.5,and PMl decreased with height.The lapse rates showed the following sequence:PM10 > PM2.5 > PM1,which indicates that the vertical distribution of fine particles is more uniform than that of coarse particles;the vertical distribution in summer is more uniform than in other seasons.     

Abstracts

Abstract

Isothermal annealing of amorphous Si and Ge has been performed by picosecond pulsed laser irradiation of free-standing films. It is found that the laser induced nucleation rate is about 10²¹-5.10²² cm^?3 s^?1 (Si) and 10²³-10²⁵ cm^?3 s^?1 (Ge) near the melting point. Arrhenius plots of the nucleation rate show that nucleation is thermally activated with an activation energy of about ΔE = 1.8 ± 0.1 eV (Ge) and ΔE = 2.47 ± 0.15 eV (Si).     

Role of material amorphicity in laser-induced phase transition

The crystallization patterns induced by nano- and picosecond laser pulses within an amorphous matrix, with various degrees of relaxation, present morphological instabilities. We show by TEM observations that the final crystalline structures of the relaxed amorphous state, after nanosecond laser excitation, and the “as-deposited” amorphous state after picosecond excitation, present similar morphology. Structurally, metastable crystalline states have been formed under laser irradiation. A probable process for these instabilities is related to competition between the light-induced electronic excitation and thermal processes during the nucleation stage.     

Origin of the variability of the mechanical properties of silk fibers: 4. Order/crystallinity along silkworm and spider fibers

The poor crystallinity of proteic fibers has fuelled an ongoing debate over their exact organization. We present a full‐range Raman comparison of Nephila madagascariensis spider and Bombyx mori silkworm silks that sheds some new light on that matter. On the one hand, a large variability is observed along the fibers in the −200 to 200 cm⁻¹ spectral window, which is sensitive to the long‐range order signature of polyamide chains. This questions the validity of previous literature data considering silk fiber as a homogeneous material. On the other hand, the ‘amide I’ band is almost independent of the targeted point, which sets a limit to this widely used structure probe. In‐line mapping of the fibers showed that the extension of the ordered zones ranges between 1 and 3 µm. The correlation between the macromechanical behavior (the stress–strain curves) and the nanomechanics (Raman low wavenumber signatures) under controlled tensile strain demonstrates a Prevorsek's type microstructure: the macromolecular chains belong to both ordered and amorphous ‘regions’. Copyright © 2014 John Wiley & Sons, Ltd.     

苯基哌嗪衍生物的NMR波谱研究

通过¹H NMR、¹³C NMR、及HMBC、HSQC、¹H-¹H DQFCOSY等2D NMR方法对新合成的10个苯基哌嗪衍生物类抗高血压药物进行结构鉴定, 并对这些化合物的¹H NMR和¹³C NMR信号进行了全归属. 初步探讨了取代基对分子¹³C化学位移的影响.      

Stable ground states for the HMF Poisson model

In this paper we prove the nonlinear orbital stability of a large class of steady state solutions to the Hamiltonian Mean Field (HMF) system with a Poisson interaction potential. These steady states are obtained as minimizers of an energy functional under one, two or infinitely many constraints. The singularity of the Poisson potential prevents from a direct run of the general strategy in [16], [19] which was based on generalized rearrangement techniques, and which has been recently extended to the case of the usual (smooth) cosine potential [17]. Our strategy is rather based on variational techniques. However, due to the boundedness of the space domain, our variational problems do not enjoy the usual scaling invariances which are, in general, very important in the analysis of variational problems. To replace these scaling arguments, we introduce new transformations which, although specific to our context, remain somehow in the same spirit of rearrangements tools introduced in the references above. In particular, these transformations allow for the incorporation of an arbitrary number of constraints, and yield a stability result for a large class of steady states.