Origin of Critical Behavior in Ethernet Traffic

We perform a simplified Ethernet traffic simulation in order to clarify the physical mechanism of the phase transition behavior which has been experimentally observed in the flow density fluctuation of Internet traffic. In one phase traffics from nodes connected with an Ethernet cable are mixed, and in the other phase, the nodes alternately send bursts of packets. The competition of sending packets among nodes and the binary exponential back-off algorithm are revealed to play important roles in producing $1/f$ fluctuations at the critical point.Comment: 14 pages, 9 figures. To appear physica

Cross-Coupling of Aryl Trifluoromethyl Sulfones with Arylboronates by Cooperative Palladium/Rhodium Catalysis

The Suzuki–Miyaura arylation of aryl trifluoromethyl sulfones via C–SO₂ bond cleavage has been developed by means of cooperative palladium/rhodium catalysis. A series of aryl trifluoromethyl sulfones and arylboronic acid neopentylglycol esters are converted to the corresponding biaryls. Mechanistic investigations suggest that (1) the rhodium catalyst mediates the transfer of the aryl ring from arylboronate to palladium, resulting in the acceleration of the transmetalation step, and (2) the C–C bond-forming reductive elimination step is the turnover-limiting step

Factors associated with "Ikigai" among members of a public temporary employment agency for seniors (Silver Human Resources Centre) in Japan; gender differences

BACKGROUND: "Ikigai" is culturally defined in the society of Japan as a comprehensive concept describing subjective well-being. It is considered to be related to life-satisfaction, self-esteem, morale, happiness as well as evaluation towards meaning of one's life. Although previous studies examined factors associated with Ikigai with smaller samples, consistent results have not been obtained, especially from the viewpoint of gender differences. Identification of gender-specific factors related with Ikigai among the elderly, may be of value to enhance subjective well-being. METHODS: Self-administered questionnaires were distributed among 4,737 randomly selected members of the Silver Human Resources Centre (SHRC), a public temporary employment agency for seniors, in Osaka, Japan. This represents about 10% of all registered members (n = 41,593) in the 38 SHRC centres in Osaka. A total of 4,376 subjects (male: 2,913; female: 1,463) provided a satisfactory response to the questionnaire (response rate: 92%). The status whether they have "Ikigai" or not was evaluated by self-anchoring scale ranging from 0 to 5 (0 = lowest rate and 5 = highest rate of having "Ikigai"). Also, self-rated life-change score through work (-3 to 3) was evaluated by three items, i.e.) changes in (1) the number of friends through work, (2) social interests and (3) the quantity of conversation with others (1 = increase, 0 = no change, and -1 = decrease). RESULTS: The factors associated with "Ikigai" for total subjects were the number of rooms in one's residence, annual income, healthy life style score (Breslow), the number of working days through SHRC, satisfaction with one's life history and life-change sore through work. The multivariable odds ratio (95%CI) of having "Ikigai" was 1.9 (1.1–3.3) for persons with no change in life thorough work compared with subjects with a score of ≦-1. Moreover, the multivariable odds ratios were 3.5 (1.9–6.6) for a life-change score = 1, 3.1 (1.7–5.7) for a score = 2 and 7.8 (4.0–15.2) for a score = 3 compared with persons with a score of ≦-1. For male subjects, other factors associated with having "Ikigai" were the number of rooms in their residence, annual income, the number of working days through SHRC, subjective assessment of health condition, and degree of satisfaction with their life history. For female, the corresponding factors were the presence of a spouse and degree of satisfaction with their life history. CONCLUSION: Scores for life-changes through work were associated with a higher prevalence of having "Ikigai" for both male and female. For male, "Ikigai" tended to be associated with physical condition and socioeconomic factors such as the size of their residence or annual income, while for female, family relations such as having spouse and psychological factors such as satisfaction with one's life history were significant factors. In spite of the design limitations of this study, it is possible to conclude that the recognition of life change through obtaining work may enhance "Ikigai" among people who wish to engage in productive activities in their later stages of life for both male and female. SHRC has a potential to provide resources for fulfilling one's "Ikigai" through supporting working opportunities to realize life changes for both elder male and female

Direct ethanol production from cellulosic materials using a diploid strain of Saccharomyces cerevisiae with optimized cellulase expression

<p>Abstract</p> <p>Background</p> <p>Hydrolysis of cellulose requires the action of the cellulolytic enzymes endoglucanase, cellobiohydrolase and β-glucosidase. The expression ratios and synergetic effects of these enzymes significantly influence the extent and specific rate of cellulose degradation. In this study, using our previously developed method to optimize cellulase-expression levels in yeast, we constructed a diploid <it>Saccharomyces cerevisiae </it>strain optimized for expression of cellulolytic enzymes, and attempted to improve the cellulose-degradation activity and enable direct ethanol production from rice straw, one of the most abundant sources of lignocellulosic biomass.</p> <p>Results</p> <p>The engineered diploid strain, which contained multiple copies of three cellulase genes integrated into its genome, was precultured in molasses medium (381.4 mU/g wet cell), and displayed approximately six-fold higher phosphoric acid swollen cellulose (PASC) degradation activity than the parent haploid strain (63.5 mU/g wet cell). When used to ferment PASC, the diploid strain produced 7.6 g/l ethanol in 72 hours, with an ethanol yield that achieved 75% of the theoretical value, and also produced 7.5 g/l ethanol from pretreated rice straw in 72 hours.</p> <p>Conclusions</p> <p>We have developed diploid yeast strain optimized for expression of cellulolytic enzymes, which is capable of directly fermenting from cellulosic materials. Although this is a proof-of-concept study, it is to our knowledge, the first report of ethanol production from agricultural waste biomass using cellulolytic enzyme-expressing yeast without the addition of exogenous enzymes. Our results suggest that combining multigene expression optimization and diploidization in yeast is a promising approach for enhancing ethanol production from various types of lignocellulosic biomass.</p

Cocktail δ-integration: a novel method to construct cellulolytic enzyme expression ratio-optimized yeast strains

<p>Abstract</p> <p>Background</p> <p>The filamentous fungus <it>T. reesei </it>effectively degrades cellulose and is known to produce various cellulolytic enzymes such as β-glucosidase, endoglucanase, and cellobiohydrolase. The expression levels of each cellulase are controlled simultaneously, and their ratios and synergetic effects are important for effective cellulose degradation. However, in recombinant <it>Saccharomyces cerevisiae</it>, it is difficult to simultaneously control many different enzymes. To construct engineered yeast with efficient cellulose degradation, we developed a simple method to optimize cellulase expression levels, named cocktail δ-integration.</p> <p>Results</p> <p>In cocktail δ-integration, several kinds of cellulase expression cassettes are integrated into yeast chromosomes simultaneously in one step, and strains with high cellulolytic activity (i.e., expressing an optimum ratio of cellulases) are easily obtained. Although the total integrated gene copy numbers of cocktail δ-integrant strain was about half that of a conventional δ-integrant strain, the phosphoric acid swollen cellulose (PASC) degradation activity (64.9 mU/g-wet cell) was higher than that of a conventional strain (57.6 mU/g-wet cell). This suggests that optimization of the cellulase expression ratio improves PASC degradation activity more so than overexpression.</p> <p>Conclusions</p> <p>To our knowledge, this is the first report on the expression of cellulase genes by δ-integration and optimization of various foreign genes by δ-integration in yeast. This method should be very effective and easily applied for other multi-enzymatic systems using recombinant yeast.</p

Transparent Exopolymer Particles in Deep Oceans: Synthesis and Future Challenges

Transparent exopolymer particles (TEP) are a class of abundant gel-like particles that are omnipresent in seawater. While versatile roles of TEP in the regulation of carbon cycles have been studied extensively over the past three decades, investigators have only recently begun to find intriguing features of TEP distribution and processes in deep waters. The emergence of new research reflects the growing attention to ecological and biogeochemical processes in deep oceans, where large quantities of organic carbon are stored and processed. Here, we review recent research concerning the role of TEP in deep oceans. We discuss: (1) critical features in TEP distribution patterns, (2) TEP sources and sinks, and (3) contributions of TEP to the organic carbon inventory. We conclude that gaining a better understanding of TEP-mediated carbon cycling requires the effective application of gel theory and particle coagulation models for deep water settings. To achieve this goal, we need a better recognition and determination of the quantities, turnover, transport, chemical properties, and microbial processing of TEP

Learning Algorithm for a Brachiating Robot

If charity begins at home, scholarship on the charitable deduction has stayed at home. In the vast legal literature, few authors have engaged the distinction between charitable contributions that are meant to be used within the United States and charitable contributions that are meant to be used abroad. Yet these two types of contributions are treated very differently in the Code and raise very different policy issues. As Americans\u27 giving patterns and the U.S. nonprofit sector grow increasingly international, the distinction will only become more salient. This Article offers the first exploration of how theories of the charitable deduction apply to internationally targeted donations. In so doing, the Article aims to contribute not only to a methodological shift in nonprofit tax scholarship (a strategic remapping), but also to a reappraisal of the deduction literature (an analytic remapping): just as existing theories of the deduction can inform our understanding of foreign charity, considerations of foreign charity can shed light back on the existing theories. I argue that the standard rationales are underdetermined and undertheorized, and propose a new, integrated approach to the charitable deduction. Internationally targeted donations emerge from the analysis holding a strong claim to deductibility – often a stronger claim than domestically targeted donations hold – on almost every relevant dimension, which calls into question current regulations that privilege domestic giving. Oversight and foreign policy concerns, however, complicate the ideal of geographic neutrality and illuminate the charitable deduction\u27s role as an instrument of statecraft. Admitting foreign charity into the debate over the deduction thus changes the debate\u27s terms; it gives deduction theory new urgency as well as new complexity

Newly Designed Specula for Laryngomicroscopy

We produced specula for laryngomicroscopy to observe blind spots in the operating field. Use of these specula has facilitated detailed observation of the lower surface of the false vocal folds, laryngeal ventricle, and subglottis, which were previously in blind spots. The specula are useful in the following ways: 1) clarifying blind spots for improved diagnosis and providing more accurate surgical margins; 2) observing the lower lips of the vocal folds in phonosurgery; and 3) Vaporizing with laser reflection. The specula are cheap and easy to use and are well worth considering for application to laryngomicroscopy