Metabolic Patterning on a Chip: Towards in vitro Liver Zonation of Primary Rat and Human Hepatocytes

An important number of healthy and diseased tissues shows spatial variations in their metabolic capacities across the tissue. The liver is a prime example of such heterogeneity where the gradual changes in various metabolic activities across the liver sinusoid is termed as “zonation” of the liver. Here, we introduce the Metabolic Patterning on a Chip (MPOC) platform capable of dynamically creating metabolic patterns across the length of a microchamber of liver tissue via actively enforced gradients of various metabolic modulators such as hormones and inducers. Using this platform, we were able to create continuous liver tissues of both rat and human origin with gradually changing metabolic activities. The gradients we have created in nitrogen, carbohydrate and xenobiotic metabolisms recapitulated an in vivo like zonation and zonal toxic response. Beyond its application in recapitulation of liver zonation in vitro as we demonstrate here, the MPOC platform can be used and expanded for a variety of purposes including better understanding of heterogeneity in many different tissues during developmental and adult stages

Straggler Robust Distributed Matrix Inverse Approximation

A cumbersome operation in numerical analysis and linear algebra, optimization, machine learning and engineering algorithms; is inverting large full-rank matrices which appears in various processes and applications. This has both numerical stability and complexity issues, as well as high expected time to compute. We address the latter issue, by proposing an algorithm which uses a black-box least squares optimization solver as a subroutine, to give an estimate of the inverse (and pseudoinverse) of real nonsingular matrices; by estimating its columns. This also gives it the flexibility to be performed in a distributed manner, thus the estimate can be obtained a lot faster, and can be made robust to \textit{stragglers}. Furthermore, we assume a centralized network with no message passing between the computing nodes, and do not require a matrix factorization; e.g. LU, SVD or QR decomposition beforehand.Comment: 4 pages, 1 figure, conferenc

Self-regulating electrical rhythms with liquid crystal oligomer networks in hybrid circuitry

Self-regulation is an essential aspect in the practicality of electronic systems, ranging from household heaters to robots for industrial manufacturing. In such devices, self-regulation is conventionally achieved through separate sensors working in tandem with control modules. In this paper, we harness the reversible actuating properties of liquid crystal oligomer network (LCON) polymers to design a self-regulated oscillator. A dynamic equilibrium is achieved by applying a thermally-responsive and electrically-functionalized LCON film as a dual-action component, namely as a combined electrical switch and composite actuating sensor, within a circuit. This hybrid circuit configuration, consisting of both inorganic and organic material, generates a self-regulated feedback loop which cycles regularly and indefinitely. The feedback loop cycle frequency is tunable between approximately 0.08 and 0.87 Hz by altering multiple factors, such as supplied power or LCON chemistry. Our research aims to drive the material-to-device transition of stimuli-responsive LCONs, striving towards applications in electronic soft robotics.</p

ОСВІТНІ ТРАДИЦІЇ ЗДОРОВОГО СПОСОБУ ЖИТТЯ УЧНІВ НАРОДНИХ ШКІЛ ЗАКАРПАТТЯ (1919–1939)

It is proved that the education of a healthy lifestyle of junior schoolchildren took place through information, training and actually educational activities aimed at the formation of sanitary and hygienic culture, healthy lifestyle, development good habits (adherence to the daily routine, proper diet, physical activity) and prevention of harmful habits (smoking, alcohol consumption, etc.). The aim of the article is to identify educational traditions of healthy lifestyle of primary school children; the analysis of the content of school textbooks used in Transcarpathian public schools during the interwar period for the content of materials on support and promotion of health. The main results of the study are to outline the possibilities of education of healthy lifestyle in primary education contents and their reflection in the subject “Citizenship Science and Education” (Civics). It has been established that the realization of the tasks took place according to the following scheme: stage 1 – educational activity aimed at the formation of hygienic culture, healthy lifestyle; 2 – acquaintance with the technologies of protection, preservation and promotion of health (rules of hygiene and sanitation, regime of the day, nutrition), aimed at forming the resistance of the organism to adverse environmental factors; 3 – physical activity as a health advantage, for children it includes games, sports, exercise, hiking, competitions, dancing, recreation or work, etc .; 4 – fight against bad habits.Доведено, що виховання здорового способу життя молодших школярів відбувалося через інформування, навчальну та власне виховну діяльність, спрямовану на формування санітарно-гігієнічної культури, здорового способу життя, вироблення корисних звичок (дотримання режиму дня, правильного способу харчування, рухової активності) та профілактику шкідливих звичок (куріння, вживання алкоголю тощо). Мета нашої статті полягає у виявленні традиції виховання здорового способу життя дітей молодшого шкільного віку; аналізі змісту шкільних підручників, які використовувались у народних школах Закарпаття міжвоєнного періоду на вміст матеріалів про підтримку і зміцнення здоров’я. Основні результати дослідження&nbsp; полягають в окресленні можливостей виховання здорового способу життя у змісті початкової освіти та віддзеркаленні їх у предметі «Горожанська наука і виховання» (громадянознавство). Встановлено, що реалізація завдань відбувалася за такою схемою: 1 етап ‒ освітня діяльність, спрямована на формування гігієнічної культури, здорового способу життя; 2 ‒ ознайомлення із технологіями захисту, збереження і зміцнення здоров’я (правила гігієни та санітарії, режим дня, харчування), спрямованими на формування стійкості організму до несприятливих факторів навколишнього середовища; 3 ‒ фізична активність як перевага здоров’я, для дітей охоплює ігри, спорт, фізичні вправи, походи, змагання, танці, активний відпочинок або працю тощо; 4 – боротьба зі шкідливими звичками

Iterative Sketching for Secure Coded Regression

In this work, we propose methods for speeding up linear regression distributively, while ensuring security. We leverage randomized sketching techniques, and improve straggler resilience in asynchronous systems. Specifically, we apply a random orthonormal matrix and then subsample \textit{blocks}, to simultaneously secure the information and reduce the dimension of the regression problem. In our setup, the transformation corresponds to an encoded encryption in an \textit{approximate gradient coding scheme}, and the subsampling corresponds to the responses of the non-straggling workers; in a centralized coded computing network. This results in a distributive \textit{iterative sketching} approach for an $\ell_2$-subspace embedding, \textit{i.e.} a new sketch is considered at each iteration. We also focus on the special case of the \textit{Subsampled Randomized Hadamard Transform}, which we generalize to block sampling; and discuss how it can be modified in order to secure the data.Comment: 28 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:2201.0852

Possible evolution of dim radio quiet neutron star 1E 1207.4-5209 based on a B-decay model

Dim radio-quiet neutron star (DRQNS) 1E 1207.4-5209 is one of the most heavily examined isolated neutron stars. Wide absorption lines were observed in its spectrum obtained by both XMM-Newton and Chandra X-ray satellites. These absorption lines can be interpreted as a principal frequency centered at 0.7 keV and its harmonics at 1.4, 2.1 and possibly 2.8 keV. The principal line can be formed by resonant proton cyclotron scattering leading to a magnetic field which is two orders of magnitude larger than the perpendicular component of the surface dipole magnetic field (B) found from the rotation period (P) and the time rate of change in the rotation period (\.{P}) of 1E 1207.4-5209. Besides, age of the supernova remnant (SNR) G296.5+10.0 which is physically connected to 1E 1207.4-5209 is two orders of magnitude smaller than the characteristic age ($\tau$=P/2\.{P}) of the neutron star. These huge differences between the magnetic field values and the ages can be explained based on a B-decay model. If the decay is assumed to be exponential, the characteristic decay time turns out to be several thousand years which is three orders of magnitude smaller than the characteristic decay time of radio pulsars represented in an earlier work. The lack of detection of radio emission from DRQNSs and the lack of point sources and pulsar wind nebulae in most of the observed SNRs can also be partly explained by such a very rapid exponential decay. The large difference between the characteristic decay times of DRQNSs and radio pulsars must be related to the differences in the magnetic fields, equation of states and masses of these isolated neutron stars.Comment: 13 pages, 1 figur

Magnetospheric particle acceleration and X-ray emission of pulsars

The available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants which are connected to some of these sources are analyzed. It is shown that electric fields of neutron stars tear off charged particles from the surface of neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of magneto-dipole radiation wave. Power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulomb interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.Comment: minor correction on table format, 20 pages (4 figures, 1 table), submitted to International Journal of Modern Physics

Détermination de l’expression des gènes codant pour le TNF-α et la leptine par RT-PCR dans le sang de vaches présentant un déplacement de la caillette à gauche

The aims of this study are to evaluate the TNF-α and leptin gene expression in blood from Holstein cows with left abomasal displacement and to correlate it with induced liver injury. The TNF-α and leptin expression in blood samples was determined by RT-PCR after normalisation using the constant expression of the housekeeping GAPDH gene in cows with left abomasal displacement (LAD) (n = 20) before surgery and 7 days after as well as in healthy controls (n = 10). Plasma hepatic enzyme (AST: aspartate aminotransferase, ALT: alanine aminotransferase and ALP: alkaline phosphatase) activities were measured in parallel. Plasma AST and ALP activities dramatically increased in diseased cows during the preoperative period and then declined. Although not significantly, the leptin expression tended to decrease in LAD affected cows while the TNF-α expression tended to increase during the postoperative period. These results suggest that TNF-α may be associated with liver damage during abomasal displacement and that leptin was inversely correlated.Les objectifs de cette étude ont été d’évaluer l’expression des gènes codant pour le TNF-α et la leptine dans le sang de vaches Holstein présentant un déplacement à gauche de la caillette et de la corréler avec les lésions hépatiques induites. L’expression du TNF-α et de la leptine a été déterminée par RT-PCR après normalisation en considérant l’expression du gène de ménage GAPDH comme constante dans les échantillons sanguins provenant de vaches atteintes d’un déplacement à gauche de la caillette (n = 20) avant et 7 jours après traitement chirurgical ou provenant de vaches saines (témoins, n = 10). Les activités plasmatiques des enzymes hépatiques (AST : aspartate aminotransférase, ALT ; alanine aminotransférase et PAL : phosphatase alcaline) ont été mesurées en parallèle. Les activités plasmatiques de l’AST et de la PAL étaient considérablement augmentées chez les vaches malades avant la chirurgie puis elles ont diminué durant la période postopératoire. Bien que les variations n’aient pas été significatives, l’expression de la leptine chez les animaux malades a tendu à diminuer alors que celle du TNF-α a augmenté durant la période postopératoire. Ces résultats suggèrent que le TNF-α pourrait être associé aux lésions hépatiques associées à un déplacement de la caillette alors que la leptine serait inversement corrélée.Scientific Research Projects Commission of Mehmet Akif Ersoy Universit