Lattice model for cold and warm swelling of polymers in water

We define a lattice model for the interaction of a polymer with water. We solve the model in a suitable approximation. In the case of a non-polar homopolymer, for reasonable values of the parameters, the polymer is found in a non-compact conformation at low temperature; as the temperature grows, there is a sharp transition towards a compact state, then, at higher temperatures, the polymer swells again. This behaviour closely reminds that of proteins, that are unfolded at both low and high temperatures.Comment: REVTeX, 5 pages, 2 EPS figure

Geometric approach to chaos in the classical dynamics of abelian lattice gauge theory

A Riemannian geometrization of dynamics is used to study chaoticity in the classical Hamiltonian dynamics of a U(1) lattice gauge theory. This approach allows one to obtain analytical estimates of the largest Lyapunov exponent in terms of time averages of geometric quantities. These estimates are compared with the results of numerical simulations, and turn out to be very close to the values extrapolated for very large lattice sizes even when the geometric quantities are computed using small lattices. The scaling of the Lyapunov exponent with the energy density is found to be well described by a quadratic power law.Comment: REVTeX, 9 pages, 4 PostScript figures include

Geometry of the energy landscape of the self-gravitating ring

We study the global geometry of the energy landscape of a simple model of a self-gravitating system, the self-gravitating ring (SGR). This is done by endowing the configuration space with a metric such that the dynamical trajectories are identified with geodesics. The average curvature and curvature fluctuations of the energy landscape are computed by means of Monte Carlo simulations and, when possible, of a mean-field method, showing that these global geometric quantities provide a clear geometric characterization of the collapse phase transition occurring in the SGR as the transition from a flat landscape at high energies to a landscape with mainly positive but fluctuating curvature in the collapsed phase. Moreover, curvature fluctuations show a maximum in correspondence with the energy of a possible further transition, occurring at lower energies than the collapse one, whose existence had been previously conjectured on the basis of a local analysis of the energy landscape and whose effect on the usual thermodynamic quantities, if any, is extremely weak. We also estimate the largest Lyapunov exponent $\lambda$ of the SGR using the geometric observables. The geometric estimate always gives the correct order of magnitude of $\lambda$ and is also quantitatively correct at small energy densities and, in the limit $N\to\infty$, in the whole homogeneous phase.Comment: 20 pages, 12 figure

Chaos in effective classical and quantum dynamics

We investigate the dynamics of classical and quantum N-component phi^4 oscillators in the presence of an external field. In the large N limit the effective dynamics is described by two-degree-of-freedom classical Hamiltonian systems. In the classical model we observe chaotic orbits for any value of the external field, while in the quantum case chaos is strongly suppressed. A simple explanation of this behaviour is found in the change in the structure of the orbits induced by quantum corrections. Consistently with Heisenberg's principle, quantum fluctuations are forced away from zero, removing in the effective quantum dynamics a hyperbolic fixed point that is a major source of chaos in the classical model.Comment: 6 pages, RevTeX, 5 figures, uses psfig, changed indroduction and conclusions, added reference

Model for the hydration of non-polar compounds and polymers

We introduce an exactly solvable statistical-mechanical model of the hydration of non-polar compounds, based on grouping water molecules in clusters where hydrogen bonds and isotropic interactions occur; interactions between clusters are neglected. Analytical results show that an effective strengthening of hydrogen bonds in the presence of the solute, together with a geometric reorganization of water molecules, are enough to yield hydrophobic behavior. We extend our model to describe a non-polar homopolymer in aqueous solution, obtaining a clear evidence of both ``cold'' and ``warm'' swelling transitions. This suggests that our model could be relevant to describe some features of protein folding.Comment: REVTeX, 6 pages, 3 figure

Бокапарвовирусная инфекция у детей в Республике Беларусь: молекулярно-эпидемиологические аспекты

Objective: To study molecular and epidemiological aspects bocaparvovirus infection at the hospitalized, children in Republic of Belarus.Materials and methods: the studies were as part of a sentinel surveillance of influenza and. other agents of acute respiratory viral infections (ARVI) in the period. 2010 — 2018. Investigated, nasopharyngeal swabs (3907), serum. (149) hospitalized. children from 0 to 18 years with symptoms of ARVI, as well as lymphoepithelial tissue of adenoids by real-time PCR (Rotor Gene 6000, Corbett research, Australia) for the presence of respiratory DNA/RNA viruses: influenza, respiratory syncytial virus, parainfluenza virus, rhinovirus, adenovirus, metapneumovirus, bocaparvovirus, and. coronavi-ruses. The full genomic DNA sequencing of the bocaparvovirus was performed, using the commercial kit «Genome Lab DTCS Quick Start Kit» (Beckman Coulter, USA). Electrophoresis and. analysis of the reaction products were performed, on a Beckman Coulter CEQ 8000 automated, capillary DNA analyzer (Beckman Coulter, USA).Results: the genetic material of respiratory viruses was detected, in 2781 cases (71,2%). Bocaparvovirus was detected in 337 (12,1%,) patients. Bocaparvovirus infection showed, an increase in the incidence rate in the autumn period. The most susceptible to this infection are children aged. 2 years to 4 years. The duration of viremia in these patients ranged, from 6 to 15 days. Phylogenetic analysis, the Belarusian, viruses HBoV1BLR/Mogilev/241/14, HBoV1BLR/Minsk/10/14, HBoV1BLR/Minsk/11/14, HBoV1BLR/Gomel/285/15 were combined into a separate group and showed genetic similarity with the ST2 virus. Analysis of the primary structure of the Belarusian bocaparvoviruses showed the presence of amino acid substitutions.Conclusion: Bocaparvovirus became the fourth, virus in frequency of occurrence along with other respiratory viruses. Bocaparvovirus infection may have a severe course. All amino acid, substitutions were located, in functionally significant regions of the virus genome.Цель: изучить молекулярно-эпидемиологические аспекты, бокапарвовирусной инфекции у госпитализированных детей в Республике Беларусь.Материалы и методы: исследования проводились в рамках дозорного надзора за гриппом и другими возбудителями острых респираторных вирусных инфекций (ОРВИ) в период 2010—2018 гг. Исследовали назофарингеальных мазки (3907), сыворотки крови (149) госпитализированных детей от 0 до 18 лет с симптомами ОРВИ, а также лимфоэпителиальную ткань аденоидов методом. ПЦР в реальном, времени (RotorGenu6000, Corbettresearch, Австралия) на наличие ДНК/РНК респираторных вирусов: гриппа, респираторно-синцитиального вируса, вируса парагриппа, риновируса, аденовируса, бокапарвовируса и коронавируса. Полногеномное секвенирование ДНК бокапарвовируса проводили с использованием, коммерческого набора «GenomeLabDTCSQuickStartKit» (BeckmanCoulter, США). Электрофорез и анализ продуктов реакции выполняли на автоматическом капиллярном ДНК-анализаторе BeckmanCoulter «CEQ 8000» (BeckmanCoulter, США).Результаты: генетический материал респираторных вирусов выявлен, в 2781 случае (71,2%). Бокапарвови-рус был выявлен, у 337 (12,1%,) пациентов. При анализе внутригодовой динамики бокапарвовирусной инфекции отмечен подъем, заболеваемости в осенний период. Наиболее восприимчивыми к данной инфекции являются дети в возрасте от 2 до 4 лет. Длительность виремии у данных пациентов варьировала от. 6 до 15 дней. Согласно данным, филогенетического анализа, белорусские вирусы HBoV1BLR/Mogilev/241/14, HBoV1BLR/Minsk/10/14, HBoV1BLR/Minsk/11/14 HBoV1BLR/Gomel/285/15 объединялись в отдельную группу и показали генетическое родство с референс-вирусом ST2. Анализ первичной структуры, белорусских бокапарвовирусов показал наличие ряда аминокислотных замен.Заключение: бокапарвовирус стал четвертым вирусом по частоте встречаемости, наряду с другими респираторными вирусами. Бокапарвовирусная инфекция может, иметь тяжелое течение. Все аминокислотные замены располагались в функционально-значимых регионах генома вируса

Pre-Flight Calibration of the Mars 2020 Rover Mastcam Zoom (Mastcam-Z) Multispectral, Stereoscopic Imager

The NASA Perseverance rover Mast Camera Zoom (Mastcam-Z) system is a pair of zoomable, focusable, multi-spectral, and color charge-coupled device (CCD) cameras mounted on top of a 1.7 m Remote Sensing Mast, along with associated electronics and two calibration targets. The cameras contain identical optical assemblies that can range in focal length from 26 mm (25.5∘×19.1∘ FOV) to 110 mm (6.2∘×4.2∘ FOV) and will acquire data at pixel scales of 148-540 μm at a range of 2 m and 7.4-27 cm at 1 km. The cameras are mounted on the rover’s mast with a stereo baseline of 24.3±0.1 cm and a toe-in angle of 1.17±0.03∘ (per camera). Each camera uses a Kodak KAI-2020 CCD with 1600×1200 active pixels and an 8 position filter wheel that contains an IR-cutoff filter for color imaging through the detectors’ Bayer-pattern filters, a neutral density (ND) solar filter for imaging the sun, and 6 narrow-band geology filters (16 total filters). An associated Digital Electronics Assembly provides command data interfaces to the rover, 11-to-8 bit companding, and JPEG compression capabilities. Herein, we describe pre-flight calibration of the Mastcam-Z instrument and characterize its radiometric and geometric behavior. Between April 26thth and May 9thth, 2019, ∼45,000 images were acquired during stand-alone calibration at Malin Space Science Systems (MSSS) in San Diego, CA. Additional data were acquired during Assembly Test and Launch Operations (ATLO) at the Jet Propulsion Laboratory and Kennedy Space Center. Results of the radiometric calibration validate a 5% absolute radiometric accuracy when using camera state parameters investigated during testing. When observing using camera state parameters not interrogated during calibration (e.g., non-canonical zoom positions), we conservatively estimate the absolute uncertainty to be 0.2 design requirement. We discuss lessons learned from calibration and suggest tactical strategies that will optimize the quality of science data acquired during operation at Mars. While most results matched expectations, some surprises were discovered, such as a strong wavelength and temperature dependence on the radiometric coefficients and a scene-dependent dynamic component to the zero-exposure bias frames. Calibration results and derived accuracies were validated using a Geoboard target consisting of well-characterized geologic samples

Dysregulation of PRMT5 in chronic lymphocytic leukemia promotes progression with high risk of Richter's transformation

: Richter's Transformation (RT) is a poorly understood and fatal progression of chronic lymphocytic leukemia (CLL) manifesting histologically as diffuse large B-cell lymphoma. Protein arginine methyltransferase 5 (PRMT5) is implicated in lymphomagenesis, but its role in CLL or RT progression is unknown. We demonstrate herein that tumors uniformly overexpress PRMT5 in patients with progression to RT. Furthermore, mice with B-specific overexpression of hPRMT5 develop a B-lymphoid expansion with increased risk of death, and Eµ-PRMT5/TCL1 double transgenic mice develop a highly aggressive disease with transformation that histologically resembles RT; where large-scale transcriptional profiling identifies oncogenic pathways mediating PRMT5-driven disease progression. Lastly, we report the development of a SAM-competitive PRMT5 inhibitor, PRT382, with exclusive selectivity and optimal in vitro and in vivo activity compared to available PRMT5 inhibitors. Taken together, the discovery that PRMT5 drives oncogenic pathways promoting RT provides a compelling rationale for clinical investigation of PRMT5 inhibitors such as PRT382 in aggressive CLL/RT cases

Internet of Things in Sustainable Energy Systems

Our planet has abundant renewable and conventional energy resources but technological capability and capacity gaps coupled with water-energy needs limit the benefits of these resources to citizens. Through IoT technology solutions and state-of-the-art IoT sensing and communications approaches, the sustainable energy-related research and innovation can bring a revolution in this area. Moreover, by the leveraging current infrastructure, including renewable energy technologies, microgrids, and power-to-gas (P2G) hydrogen systems, the Internet of Things in sustainable energy systems can address challenges in energy security to the community, with a minimal trade-off to environment and culture. In this chapter, the IoT in sustainable energy systems approaches, methodologies, scenarios, and tools is presented with a detailed discussion of different sensing and communications techniques. This IoT approach in energy systems is envisioned to enhance the bidirectional interchange of network services in grid by using Internet of Things in grid that will result in enhanced system resilience, reliable data flow, and connectivity optimization. Moreover, the sustainable energy IoT research challenges and innovation opportunities are also discussed to address the complex energy needs of our community and promote a strong energy sector economy