A simple model for DNA denaturation

Following Poland and Scheraga, we consider a simplified model for the denaturation transition of DNA. The two strands are modeled as interacting polymer chains. The attractive interactions, which mimic the pairing between the four bases, are reduced to a single short range binding term. Furthermore, base-pair misalignments are forbidden, implying that this binding term exists only for corresponding (same curvilinear abscissae) monomers of the two chains. We take into account the excluded volume repulsion between monomers of the two chains, but neglect intra-chain repulsion. We find that the excluded volume term generates an effective repulsive interaction between the chains, which decays as $1/r^{d-2}$. Due to this long-range repulsion between the chains, the denaturation transition is first order in any dimension, in agreement with previous studies.Comment: 10 page

Re-entrant ferroelectricity in liquid crystals

The ferroelectric (Sm C$^*$) -- antiferroelectric (Sm C$^*_A$) -- reentrant ferroelectric (re Sm C$^*$) phase temperature sequence was observed for system with competing synclinic - anticlinic interactions. The basic properties of this system are as follows (1) the Sm C$^*$ phase is metastable in temperature range of the Sm C$^*_A$ stability (2) the double inversions of the helix handedness at Sm C$^*$ -- Sm C$^*_A$ and Sm C$^*_A$% -- re-Sm C$^*$ phase transitions were found (3) the threshold electric field that is necessary to induce synclinic ordering in the Sm C$^*_A$ phase decreases near both Sm C$^*_A$ -- Sm C$^*$ and Sm C$^*_A$ -- re-Sm C$^*$ phase boundaries, and it has maximum in the middle of the Sm C$^*_A$ stability region. All these properties are properly described by simple Landau model that accounts for nearest neighboring layer steric interactions and quadrupolar ordering only.Comment: 10 pages, 5 figures, submitted to PR

Ground State Energy of the One-Component Charged Bose Gas

The model considered here is the `jellium' model in which there is a uniform, fixed background with charge density $-e\rho$ in a large volume $V$ and in which $N=\rho V$ particles of electric charge $+e$ and mass $m$ move --- the whole system being neutral. In 1961 Foldy used Bogolubov's 1947 method to investigate the ground state energy of this system for bosonic particles in the large $\rho$ limit. He found that the energy per particle is $-0.402 r_s^{-3/4} {me^4}/{\hbar^2}$ in this limit, where $r_s=(3/4\pi \rho)^{1/3}e^2m/\hbar^2$. Here we prove that this formula is correct, thereby validating, for the first time, at least one aspect of Bogolubov's pairing theory of the Bose gasComment: 38 pages latex. Typos corrected.Lemma 6.2 change

Mesenchymal stem cell-derived extracellular vesicles protect human corneal endothelial cells from endoplasmic reticulum stress-mediated apoptosis

Corneal endothelial dystrophy is a relevant cause of vision loss and corneal transplantation worldwide. In the present study, we analyzed the effect of mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in an in vitro model of corneal dystrophy, characterized by endoplasmic reticulum stress. The effects of MSC-EVs were compared with those of serum-derived EVs, reported to display a pro-angiogenic activity. MSC-EVs were able to induce a significant down-regulation of the large majority of endoplasmic reticulum stress-related genes in human corneal endothelial cells after exposure to serum deprivation and tunicamycin. In parallel, they upregulated the Akt pathway and limited caspase-3 activation and apoptosis. At variance, the effect of the serum EVs was mainly limited to Akt phosphorylation, with minimal or absent effects on endoplasmic reticulum stress modulation and apoptosis prevention. The effects of MSC-EVs were correlated to the transfer of numerous endoplasmic reticulum (ER)-stress targeting miRNAs to corneal endothelial cells. These data suggest a potential therapeutic effect of MSC-EVs for corneal endothelial endoplasmic reticulum stress, a major player in corneal endothelial dystrophy

Calcium magneto-optical trap loaded from a decelerated atomic beam

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOWe describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the ¹S0 -¹ P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 10(7) atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.332355362FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOSem informaçãoSem informaçãoSem informaçãoWe would like to acknowledge the glass shop of the UNICAMP Physics Institute for the very well done work in the construction of the atomic beam and MOT glass chamber. We also would like to thank the machine shop and J.B.Rodrigues for the mechanical parts. This work was supported by FAPESP, CAPES and CNPq and FAEPUNICAMP, Brazilian government agencies. Support for RLCF was through CAPES graduate research scholarship and for DAM and DRO through FAPESP graduate and undergraduate scholarships respectively

Hybrid Particle-Continuum Simulations of Nonequilibrium Hypersonic Blunt-Body Flowfields

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77319/1/AIAA-30216-565.pd

Evaluation of a Hybrid Boltzmann-Continuum Method for High Speed Nonequilibrium Flows

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83556/1/AIAA-2010-1569-683.pd

Extension of a Multiscale Particle Scheme to Near-Equilibrium Viscous Flows

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76880/1/AIAA-40262-641.pd

Post-meeting report of the 2022 On-site Padua Days on Muscle and Mobility Medicine, March 30 - April 3, 2022, Padua, Italy.

Despite COVID-19 outbreak, the program of the 2022 Padua Days of Muscle and Mobility Medicine (PDM3) was confirmed On-site in February from March 30 to April 2, 2022 to be held at the University of Padua Aula Magna and at Conference Hall of the Hotel Petrarca of Thermae of Euganean Hills (Padua), Italy. Over 130 abstracts, including the last-minute submissions listed below, convinced organizers to extend the program to five days. The sponsorship of the University of Florida and the willingness of attendees to meet friends after two years of virtual conferences were the keys of success, despite concerns for current events in East Europe. Only fourteen Virtual presentations were in the final program, eight due to last-minute Coronavirus infections and six for East Europe problems. The first two days of the programincluded scientists and clinicians of the University of Florida, USA and their invitees from Canada, France, Italy, Swiden, Swiss, UK and USA. Researchers and clinicians from Austria, Belgium, France, Germany, Iceland, Ireland, Italy, Russia, Slovakia, Slovenia, UK and USA filled the program of last three days more oriented to aging and rehabilitation. The large majority of abstracts was e-published before the meeting; here are last-minute abstracts and the final program. The program of the 2023 On-site PDM3 was informally designed during the Meeting, but will be circulated during 2022 summer. Fix the dates in your agenda from Thursday March 28 to Friday March 31. For now, please, submit Communications to the European Journal of Translational Myology, PAGEpress, Pavia, Italy and Original Articles or Reviews to the Journal Diagnostics, MDPI, Basel, Swiss. Both journals will host Special PDM3 Sections and will apply 50% discount on editorial processing fees to the first 15 accepted typescripts

The Peach v2.0 Release : An Improved Genome Sequence for Bridging the Gap Between Genomics and Breeding in Prunus

Since its release the high quality peach genome sequence (Peach v1.0) has fostered studies on comparative genomics as well as on genetic diversity, domestication and crop improvement in Prunus and related species. To improve the chromosome-scale assembly and genome annotation we performed further analyses. Extensive mapping data allowed the improvement of Peach v2.0 assembly in terms of fraction of mapped (99.2%) and orientated (97.9%) sequences and correction of misassembly issues (about 12.2 Mb of incorrectly positioned sequences). Assembled resequencing data (42x) improved base accuracy and contiguity: 859 SNPs and 1,347 Indels were corrected and 212 gaps were closed. As a result the contiguity of Peach v2.0 improved with a contig L50 of 255.4 kb (previously 214.2 kb) and a contig N50 of 250 (previously 294). Repeat annotation was enhanced including low copy repeats and the complete sequence and location of 1,157 non autonomous Helitrons. Gene prediction and annotation were improved using transcript assemblies obtained from 2.2 billion of RNA seq reads from different peach tissues and organs. In total, after masking with the improved repeat annotation, 26,873 protein-coding genes were predicted in Peach v2.1 annotation, 991 less than those predicted in Peach v1.0. Gene annotation was highly enhanced with the prediction of almost 20,000 new isoforms. The new peach release with improved assembly and annotation will be a pivotal resource for comparative genomics in the plant kingdom and will serve as a foundation for studies bridging the gap between genomics and breeding in Prunus and related species