Heteropolymer Sequence Design and Preferential Solvation of Hydrophilic Monomers: One More Application of Random Energy Model

In this paper, we study the role of surface of the globule and the role of interactions with the solvent for designed sequence heteropolymers using random energy model (REM). We investigate the ground state energy and surface monomer composition distribution. By comparing the freezing transition in random and designed sequence heteropolymers, we discuss the effects of design. Based on our results, we are able to show under which conditions solvation effect improves the quality of sequence design. Finally, we study sequence space entropy and discuss the number of available sequences as a function of imposed requirements for the design quality

Model-Based Estimation Techniques for 3-D Reconstruction from Projections

A parametric estimation approach to reconstruction from projections with incomplete and very noisy data is described. Embedding prior knowledge about "objects" in the probed domain and about the data acquisition process into stochastic dynamic models, we transform the reconstruction problem into a computationally ,challenging nonlinear state-estimation problem, where the objects' parametrized descriptions are to be directly estimated from the projection data. This paper is a review in a common framework and a comparative study of two distinct algorithms which were developed recently for the solution of this problem. The first, is an approximate, globally optimal minimum-meansquare- error recursive algorithm. The second is a hierarchical suboptimal Bayesian algorithm. Simulation examples demonstrate accurate reconstructions with as few as four views in a 135 ~ sector, at an average signal to noise ratio of 0.6.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85941/1/Fessler114.pd

On the poverty of a priorism: technology, surveillance in the workplace and employee responses

Many debates about surveillance at work are framed by a set of a priori assumptions about the nature of the employment relationship that inhibits efforts to understand the complexity of employee responses to the spread of new technology at work. In particular, the debate about the prevalence of resistance is hamstrung from the outset by the assumption that all apparently non-compliant acts, whether intentional or not, are to be counted as acts of resistance. Against this background this paper seeks to redress the balance by reviewing results from an ethnographic study of surveillance-capable technologies in a number of British workplaces. It argues for greater attention to be paid to the empirical character of the social relations at work in and through which technologies are deployed and in the context of which employee responses are played out

Two-photon spin injection in semiconductors

A comparison is made between the degree of spin polarization of electrons excited by one- and two-photon absorption of circularly polarized light in bulk zincblende semiconductors. Time- and polarization-resolved experiments in (001)-oriented GaAs reveal an initial degree of spin polarization of 49% for both one- and two-photon spin injection at wavelengths of 775 and 1550 nm, in agreement with theory. The macroscopic symmetry and microscopic theory for two-photon spin injection are reviewed, and the latter is generalized to account for spin-splitting of the bands. The degree of spin polarization of one- and two-photon optical orientation need not be equal, as shown by calculations of spectra for GaAs, InP, GaSb, InSb, and ZnSe using a 14x14 k.p Hamiltonian including remote band effects. By including the higher conduction bands in the calculation, cubic anisotropy and the role of allowed-allowed transitions can be investigated. The allowed-allowed transitions do not conserve angular momentum and can cause a high degree of spin polarization close to the band edge; a value of 78% is calculated in GaSb, but by varying the material parameters it could be as high as 100%. The selection rules for spin injection from allowed-allowed transitions are presented, and interband spin-orbit coupling is found to play an important role.Comment: 12 pages including 7 figure

GPU enabled real-time optical frequency comb spectroscopy and photonic readout

We describe a GPU-enabled approach for real-time optical frequency comb spectroscopy in which data is recorded, Fourier transformed, normalized, and fit at data rates up to 2.2 GB/s. As an initial demonstration we have applied this approach to rapidly interrogate the motion of an optomechanical accelerometer through the use of an electro-optic frequency comb. However, we note that this approach is readily amenable to both self-heterodyne and dual comb spectrometers for molecular spectroscopy as well as photonic readout where the approach's agility, speed, and simplicity are expected to enable future improvements and applications

К ВОПРОСУ О РОЛИ СИМВОЛИЧЕСКОГО В ИДЕНТИФИКАЦИИ ЧЕЛОВЕКА ИНФОРМАЦИОННОГО/ЦИФРОВОГО ОБЩЕСТВА

The transformation of society during the transition to a new stage of civilizational development is accompanied by dichotomous phenomena. Against the background of globalization processes, a decrease in the role of the national, associated with numbers and the development of global network digital communications, there is a sharp increase in ethnic and religious factors, the actualization of historical symbols as elements of human identity and the collective identity of a nation or country. This phenomenon is considered from the standpoint of postmodernism, where the object of the past is simulated into the subjective perception of a simulacrum in the consciousness of a person in modern society. We criticize metamodernism, proving the symbolic nature of oscillation. The appeal to the past in modernity is nothing but the construction of traditions, rituals, customs in new conditions, under the influence of the present, that is, the simulation of current economic and political, socio-cultural processes. The formation of identity is considered both from the side of the external influence of the institutions of power and management and the elite, and from the side of adaptation of human consciousness that occurs under the influence of the transformations of society. Institutions of power and government contribute to the creation and dissemination of simulacra of historical, ethnic, religious constructs. This allows the upper strata of society to form the collective identity they require, to homogenize society, affirming a single symbolism, common values for all residents. A modern person, for the reasons considered in the article, strives for multiple identification, which is due to the desire to strengthen communication with a multitude of communities that are formed on the basis of a commonality of symbols, values, codes. Experiencing existential fear of a digital society, a person seeks shelter in the images of the past, in the simulation of the stasis of his contemporary society based on the symbols of history, religion, and ethnicity. The second reason is the desire to enter the largest number of communities, staying in which allows you to strengthen the quality and quantity of communications, increase the ability to adapt, and reduce the level of risk. The specific features of the younger generation Z are considered separately. Born with a “gadget in hand”, digital natives are initially adapted in a digital society, and therefore their perception is somewhat different than that of the older generation. The cited research data of the authors shows significant specific differences in the perception of the values of previous eras among the younger generation, which allows us to hope for a weakening of the tendencies for the formation of identity based on archaic symbols in the near future.Трансформация общества в процессе перехода на новую стадию цивилизационного развития сопровождается дихотомическими явлениями. На фоне глобализационных процессов, снижением роли национального, связанного в том чисел и с развитием глобальных сетевых цифровых коммуникаций наблюдается резкий рост этнического и религиозного факторов, актуализации исторических символов как элементов идентичности человека и коллективной идентичности нации, страны. Данное явление рассматривается с позиций постмодернизма, где объект прошлого симулируется в субъективное восприятие симулякра в сознании человека современного общества. Мы выступаем с критикой метамодернизма, доказывая символический характер осцилляции. Обращения к прошлому в современности не что иное, как конструирование традиций, ритуалов, обычаев в новых условиях, под воздействием настоящего, то есть симуляция актуальных экономико–политических, социокультурных актуальных процессов. Формирование идентичности рассмотрено как состороны внешнего влияния институтов власти и управления и элиты, так и со стороны адаптации сознания человека, происходящей под влиянием трансформаций общества. Институты власти и управления способствуют созданию и распространению симулякров исторических, этнических, религиозных конструктов. Это позволяет высшим слоям общества формировать требуемую им коллективную идентичность, гомогенизировать общество, утверждая единую символику, единые ценности для всех жителей. Современный человек, по причинам, рассматриваемых в статье, стремиться к множественной идентификации, что обусловлено стремлением к усилению коммуникаций с множеством сообществ, формирующихся на основе общности символов, ценностей, кодов. Испытывая экзистенциальный страх перед цифровым обществом, человек ищет укрытия в образах прошлого, в симуляции стазиса современного ему общества на основе символов истории, религии, этноса. Вторая причина – стремление к вхождению в наибольшее число сообществ, пребывание в которых позволяет усиливать качество и количество коммуникаций, повысить способность к адаптации, снизить уровень риска. Отдельно рассмотрены специфические особенности молодого поколения Z. Родившись с «гаджетом в руке» цифровые аборигены изначально адаптированы в цифровом обществе, а потому их восприятие не-сколько иное, чем у старшего поколения. Приведенные данные исследования авторов показывает существенные специфические отличия в восприятии ценностей предыдущих эпох у молодого поколения, что позволяет надеяться на ослабление тенденций формирования идентичности на основе архаичных символов в ближайшем будущем

Agile chip-scale electro-optic frequency comb spectrometer with millivolt drive voltages

Here, we present an on-chip spectrometer that leverages an integrated thin-film lithium niobate modulator to produce a frequency-agile electro-optic frequency comb for interrogating chip-scale temperature and acceleration sensors. The low half-wave voltage, $V_{\pi}$, of the modulators and the chirped comb process allows for ultralow radiofrequency drive voltages, which are as much as seven orders of magnitude less than the lowest found in the literature and are generated using a chip-scale, microcontroller-driven direct digital synthesizer. The on-chip comb spectrometer is able to simultaneously interrogate both the on-chip temperature sensor and an off-chip, microfabricated optomechanical accelerometer with cutting-edge sensitivities of $\approx 5 {\mu} \mathrm{K} \cdot \mathrm{Hz} ^{-1/2}$ and $\approx 130 {\mu}\mathrm{m} \cdot \mathrm{s}^{-2} \cdot \mathrm{Hz}^{-1/2}$, respectively. Notable strengths of this platform include the frequency agility of the optical frequency combs, ultralow radiofrequency power requirements and compatibility with a broad range of existing photonic integrated circuit technologies.Comment: 11 pages, 5 figure

Safe and complete contig assembly via omnitigs

Contig assembly is the first stage that most assemblers solve when reconstructing a genome from a set of reads. Its output consists of contigs -- a set of strings that are promised to appear in any genome that could have generated the reads. From the introduction of contigs 20 years ago, assemblers have tried to obtain longer and longer contigs, but the following question was never solved: given a genome graph $G$ (e.g. a de Bruijn, or a string graph), what are all the strings that can be safely reported from $G$ as contigs? In this paper we finally answer this question, and also give a polynomial time algorithm to find them. Our experiments show that these strings, which we call omnitigs, are 66% to 82% longer on average than the popular unitigs, and 29% of dbSNP locations have more neighbors in omnitigs than in unitigs.Comment: Full version of the paper in the proceedings of RECOMB 201