Fatigue tests of materials with the controlled energy parameter amplitude

Abstract The paper presents a procedure of the determination of the fatigue energy characteristic diagram by using a controlled strain energy parameter which can be an alternative to the well-known stress and strain fatigue curves description of structural materials. The work contains the results of fatigue tests carried out in accordance with the procedure shown in the paper. Obtained test results were presented on diagrams and critically discussed

Contribuição do colmo principal na qualidade de grãos de duas cultivares de arroz (Oryza sativa L.), em comparação aos perfilhos.

Este trabalho teve como objetivo avaliar a contribuição do colmo principal na qualidade de grãos, de duas cultivares de arroz, em comparação aos perfilhos

Statistical ensemble of scale-free random graphs

A thorough discussion of the statistical ensemble of scale-free connected random tree graphs is presented. Methods borrowed from field theory are used to define the ensemble and to study analytically its properties. The ensemble is characterized by two global parameters, the fractal and the spectral dimensions, which are explicitly calculated. It is discussed in detail how the geometry of the graphs varies when the weights of the nodes are modified. The stability of the scale-free regime is also considered: when it breaks down, either a scale is spontaneously generated or else, a "singular" node appears and the graphs become crumpled. A new computer algorithm to generate these random graphs is proposed. Possible generalizations are also discussed. In particular, more general ensembles are defined along the same lines and the computer algorithm is extended to arbitrary (degenerate) scale-free random graphs.Comment: 10 pages, 6 eps figures, 2-column revtex format, minor correction

Analysis of factors that influence eating habits in different countries

Individual eating habits are influenced by a number of factors, including both internal variables such as physiology and emotion, as well as environmental factors such as food availability and cultural norms. Given the public health impact of dietary habits (choice, quality, amount, frequency) on health outcomes, it is important to understand what factors influence eating habits on a societal level. The aim of this research was to determine factors that influence eating habits and compare these factors between four different countries – Latvia, Lithuania, Portugal and the USA. An eating motivation questionnaire was used to measure eating habits in 3,348 respondents from different regions and countries. There were ten parts - demographical information, anthropometric data and behavioral and health related elements, sources of information about healthy eating, factors related to food choices according to motivations (health, emotional, economic, availability, social, cultural, environmental, political, marketing and commercials). Data were analyzed using descriptive statistics, and self-reported motivation was compared across countries. Health was the primary motivator of food selection in this sample (71% of respondents), whereas 34% reported that emotional factors impact their dietary habits and 35% reported that economic factors determine their food selection. A large number of respondents (44%) disagreed or strongly disagree or disagreed with the idea that marketing impacts their dietary habits. Portugal had the highest number of participants (86%), reporting that they agreed or strongly agreed with having health-related motivations for food selection, with Latvia (65%) and Lithuania (76%) showing more moderate levels of endorsement of healthy eating motivations, and the USA having the fewest respondents (52%) endorsing health-related motivations. Respondents from Portugal were more likely than respondents from the other countries to deny having emotional, economic and marketing motivations in food selection. From results can conclude that consumers are motivated by healthiness factors when making food choices (71% of respondents), but marketing, economic and emotional factors positively impact only 30% of consumers, other respondents completely disagreed or was indifferent to these types of motivations. Baltic countries (Latvia and Lithuania) were similar to each other, but Portugal and USA were completely different. Portugal strongly agreed with healthy motivations and disagreed with all other motivations, whereas USA and also Baltic countries had more equal division of opinions regarding impact of different motivations.info:eu-repo/semantics/publishedVersio

Excessive folate synthesis limits lifespan in the C. elegans: E. coli aging model

Background: Gut microbes influence animal health and thus, are potential targets for interventions that slow aging. Live E. coli provides the nematode worm Caenorhabditis elegans with vital micronutrients, such as folates that cannot be synthesized by animals. However, the microbe also limits C. elegans lifespan. Understanding these interactions may shed light on how intestinal microbes influence mammalian aging. Results: Serendipitously, we isolated an E. coli mutant that slows C. elegans aging. We identified the disrupted gene to be aroD, which is required to synthesize aromatic compounds in the microbe. Adding back aromatic compounds to the media revealed that the increased C. elegans lifespan was caused by decreased availability of para-aminobenzoic acid, a precursor to folate. Consistent with this result, inhibition of folate synthesis by sulfamethoxazole, a sulfonamide, led to a dose-dependent increase in C. elegans lifespan. As expected, these treatments caused a decrease in bacterial and worm folate levels, as measured by mass spectrometry of intact folates. The folate cycle is essential for cellular biosynthesis. However, bacterial proliferation and C. elegans growth and reproduction were unaffected under the conditions that increased lifespan. Conclusions: In this animal:microbe system, folates are in excess of that required for biosynthesis. This study suggests that microbial folate synthesis is a pharmacologically accessible target to slow animal aging without detrimental effects

The spectral dimension of generic trees

We define generic ensembles of infinite trees. These are limits as $N\to\infty$ of ensembles of finite trees of fixed size $N$, defined in terms of a set of branching weights. Among these ensembles are those supported on trees with vertices of a uniformly bounded order. The associated probability measures are supported on trees with a single spine and Hausdorff dimension $d_h =2$. Our main result is that their spectral dimension is $d_s=4/3$, and that the critical exponent of the mass, defined as the exponential decay rate of the two-point function along the spine, is 1/3

Superfield description of 5D supergravity on general warped geometry

We provide a systematic and practical method of deriving 5D supergravity action described by 4D superfields on a general warped geometry, including a non-BPS background. Our method is based on the superconformal formulation of 5D supergravity, but is easy to handle thanks to the superfield formalism. We identify the radion superfield in the language of 5D superconformal gravity, and clarify its appearance in the action. We also discuss SUSY breaking effects induced by a deformed geometry due to the backreaction of the radius stabilizer.Comment: 25 pages, no figures, LaTeX, final version to appear in JHE

Neutrino Democracy, Fermion Mass Hierarchies And Proton Decay From 5D SU(5)

The explanation of various observed phenomena such as large angle neutrino oscillations, hierarchies of charged fermion masses and CKM mixings, and apparent baryon number conservation may have a common origin. We show how this could occur in 5D SUSY SU(5) supplemented by a ${\cal U}(1)$ flavor symmetry and additional matter supermultiplets called 'copies'. In addition, the proton decays into $p\to K\nu$, with an estimated lifetime of order $10^{33}-10^{36}$ yrs. Other decay channels include $Ke$ and $K\mu$ with comparable rates. We also expect that BR$(\mu \to e\gamma)\sim$BR$(\tau \to \mu \gamma)$