A model for the dynamics of extensible semiflexible polymers

We present a model for semiflexible polymers in Hamiltonian formulation which interpolates between a Rouse chain and worm-like chain. Both models are realized as limits for the parameters. The model parameters can also be chosen to match the experimental force-extension curve for double-stranded DNA. Near the ground state of the Hamiltonian, the eigenvalues for the longitudinal (stretching) and the transversal (bending) modes of a chain with N springs, indexed by p, scale as lambda_lp ~ (p/N)^2 and lambda_tp ~ p^2(p-1)^2/N^4 respectively for small p. We also show that the associated decay times tau_p ~ (N/p)^4 will not be observed if they exceed the orientational time scale tau_r ~ N^3 for an equally-long rigid rod, as the driven decay is then washed out by diffusive motion.Comment: 28 pages, 2 figure

Особенности функционального состояния почек белых крыс в условиях хронической гипернатриевой диеты

Целью работы было исследование адаптации неповрежденных почек белых крыс к хроническому гипернатриевому рациону. Установлено, что особенности деятельности почек в условиях хронического гипернатриевого рациона не связаны полностью с естественными возрастными изменениями деятельности почек, а обусловлены так же исчерпанием резервных возможностей почечной паренхимыThe purpose of work was research of acclimatization of uninjured kidneys of white rats to a chronic hypersodium ration. It fixed, that features of activity of kidneys in conditions of a chronic hypersodium ration are not depended completely to natural age changes of activity of kidneys, and caused as by exhaustion of reserve opportunities of a renal parenchyma

The world according to Playmobil

This article looks at toys for very small children, an object of study that has been pursued in psychoanalysis (by Freud and Erikson, for example), but all too infrequently in semiotics. Specifically, it analyzes the social roles and identities called into play by the highly successful Playmobil figurines. In the Hallidayan tradition, the investigation foregrounds the importance of roles and actors in semiosis, paying close attention to roles/actors that are excluded as well as those that are included. As the essay argues, semiotic systems are always a mixture of affordance and constraint. Playmobil (in contrast to Lego, for example) is shown to be stronger on constraints than affordances, however. As a global brand and genre, the figures of Playmobil have the potential to influence nascent perceptions of the way that social actors operate. © 2009 by Walter de Gruyter GmbH & Co. KG

Learning what matters - Sampling interesting patterns

In the field of exploratory data mining, local structure in data can be described by patterns and discovered by mining algorithms. Although many solutions have been proposed to address the redundancy problems in pattern mining, most of them either provide succinct pattern sets or take the interests of the user into account-but not both. Consequently, the analyst has to invest substantial effort in identifying those patterns that are relevant to her specific interests and goals. To address this problem, we propose a novel approach that combines pattern sampling with interactive data mining. In particular, we introduce the LetSIP algorithm, which builds upon recent advances in 1) weighted sampling in SAT and 2) learning to rank in interactive pattern mining. Specifically, it exploits user feedback to directly learn the parameters of the sampling distribution that represents the user's interests. We compare the performance of the proposed algorithm to the state-of-the-art in interactive pattern mining by emulating the interests of a user. The resulting system allows efficient and interleaved learning and sampling, thus user-specific anytime data exploration. Finally, LetSIP demonstrates favourable trade-offs concerning both quality-diversity and exploitation-exploration when compared to existing methods.Comment: PAKDD 2017, extended versio

Does individual variation in metabolic phenotype predict fish behaviour and performance?

There is increasing interest in documenting and explaining the existence of marked intraspecific variation in metabolic rate in animals, with fishes providing some of the best-studied examples. After accounting for variation due to other factors, there can typically be a two to three-fold variation among individual fishes for both standard and maximum metabolic rate (SMR and MMR). This variation is reasonably consistent over time (provided that conditions remain stable), and its underlying causes may be influenced by both genes and developmental conditions. In this paper, current knowledge of the extent and causes of individual variation in SMR, MMR and aerobic scope (AS), collectively its metabolic phenotype, is reviewed and potential links among metabolism, behaviour and performance are described. Intraspecific variation in metabolism has been found to be related to other traits: fishes with a relatively high SMR tend to be more dominant and grow faster in high food environments, but may lose their advantage and are more prone to risk-taking when conditions deteriorate. In contrast to the wide body of research examining links between SMR and behavioural traits, very little work has been directed towards understanding the ecological consequences of individual variation in MMR and AS. Although AS can differ among populations of the same species in response to performance demands, virtually nothing is known about the effects of AS on individual behaviours such as those associated with foraging or predator avoidance. Further, while factors such as food availability, temperature, hypoxia and the fish's social environment are known to alter resting and MMRs in fishes, there is a paucity of studies examining how these effects vary among individuals, and how this variation relates to behaviour. Given the observed links between metabolism and measures of performance, understanding the metabolic responses of individuals to changing environments will be a key area for future research because the environment will have a strong influence on which animals survive predation, become dominant and ultimately have the highest reproductive success. Although current evidence suggests that variation in SMR may be maintained within populations via context-dependent fitness benefits, it is suggested that a more integrative approach is now required to fully understand how the environment can modulate individual performance via effects on metabolic phenotypes encompassing SMR, MMR and AS

Image charge dynamics in time-dependent quantum transport

In this work we investigate the effects of the electron-electron interaction between a molecular junction and the metallic leads in time-dependent quantum transport. We employ the recently developed embedded Kadanoff-Baym method [Phys. Rev. B 80, 115107 (2009)] and show that the molecule-lead interaction changes substantially the transient and steady-state transport properties. We first show that the mean-field Hartree-Fock (HF) approximation does not capture the polarization effects responsible for the renormalization of the molecular levels neither in nor out of equilibrium. Furthermore, due to the time-local nature of the HF self-energy there exists a region in parameter space for which the system does not relax after the switch-on of a bias voltage. These and other artifacts of the HF approximation disappear when including correlations at the second-Born or GW levels. Both these approximations contain polarization diagrams which correctly account for the screening of the charged molecule. We find that by changing the molecule-lead interaction the ratio between the screening and relaxation time changes, an effect which must be properly taken into account in any realistic time-dependent simulation. Another important finding is that while in equilibrium the molecule-lead interaction is responsible for a reduction of the HOMO-LUMO gap and for a substantial redistribution of the spectral weight between the main spectral peaks and the induced satellite spectrum, in the biased system it can have the opposite effect, i.e., it sharpens the spectral peaks and opens the HOMO-LUMO gap.Comment: 18 pages, 26 figure

National scientific capabilities and technological performance: An exploration of emerging industrial relevant research domains.

Today's theories and models on innovation stress the importance of scientific capabilities and science-technology proximity, especially in new emerging fields of economic activity. In this contribution we examine the relationship between national scientific capabilities, the science intensity of technology and technological performance within six promising industrial fields. Our findings reveal that national technological performance is positively associated with scientific capabilities. Countries performing better on a technological level are characterized both by larger numbers of publications and by numbers of involved institutions that exceed average expected values. The latter observation holds for both companies and knowledge generating institutes actively involved in scientific activities. As such, our findings seem to suggest beneficial effects of scientific capabilities shouldered by a multitude of organizations. In addition, higher numbers of patent activity coincide with higher levels of science intensity pointing out the relevance of science 'proximity' when developing technology in newer, emerging fields. Limitations and directions for further research are discussed.Performance; Research; Theory; Models; Model; Innovation; Field; Science; Intensity; Technology; Country; Expected; Value; Companies; Knowledge; Effects;

The goldberg variations I: Assessing the academic quality of multidimensional linear texts and their re-emergence in multimedia publications

After an introduction on the recent history of academic publishing in non-linear media, the article compares two versions of an academic publication by the American sociologist David Theo Goldberg. The two versions deal with the same subject matter, but one is a traditional scholarly article, the other published in an online journal in a non-linear format. While the academic article constructs a tight, linear argument, subordinating a range of themes to a single key theme, the non-linear text gives all themes equal weight, accommodates a greater amount of evidence and documentation, and has more scope for multimodality. © The Author(s) 2010