Bottom-loading dilution refrigerator with ultra-high vacuum deposition capability

A Kelvinox 400 dilution refrigerator with the ability to load samples onto the mixing chamber from the bottom of the cryostat has been combined with an ultrahigh-vacuum (UHV) deposition chamber equipped with molecular beam sources. The liquid helium cooled sample transfer mechanism is used in a manner that allows films to be grown on substrates which are kept at temperatures of order 8K with chamber pressures in the 10^-9 to 10^-10 Torr range. This system facilitates the growth of quench-condensed ultrathin films which must always be kept below ~ 12K in a UHV environment during and after growth. Measurements can be made on the films down to millikelvin temperatures and in magnetic fields up to 15 T.Comment: 10 pages text, 1figur

The ontology of temperature in nonequilibrium systems

The laws of thermodynamics provide a clear concept of the temperature for an equilibrium system in the continuum limit. Meanwhile, the equipartition theorem allows one to make a connection between the ensemble average of the kinetic energy and the uniform temperature. When a system or its environment is far from equilibrium, however, such an association does not necessarily apply. In small systems, the regression hypothesis may not even apply. Herein, we show that in small nonequilibrium systems, the regression hypothesis still holds though with a generalized definition of the temperature. The latter must now be defined for each such manifestation.Comment: J.Chem.Phys. (in press); 23 pages, 3 figures, 1 tabl

Use of approximations of Hamilton-Jacobi-Bellman inequality for solving periodic optimization problems

We show that necessary and sufficient conditions of optimality in periodic optimization problems can be stated in terms of a solution of the corresponding HJB inequality, the latter being equivalent to a max-min type variational problem considered on the space of continuously differentiable functions. We approximate the latter with a maximin problem on a finite dimensional subspace of the space of continuously differentiable functions and show that a solution of this problem (existing under natural controllability conditions) can be used for construction of near optimal controls. We illustrate the construction with a numerical example.Comment: 29 pages, 2 figure

Current Status and Future Strategy in \u3ci\u3eMegathyrsus maximus\u3c/i\u3e Breeding Program at the Alliance Bioversity - CIAT

Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs is one of the most important grass species cultivated for cattle production in cut and carry systems. There is a need to search for superior hybrids with high potential for mitigation and adaptation to climate change. A big proportion of the M. maximus germplasm, preserved in the CIAT GeneBank has been agronomically characterized and genotypes with desirable traits such as high drought tolerance, high BNI potential (Biological nitrification inhibition), high nutritional quality (biomass production, dry matter, crude protein, acid detergent fiber, neutral detergent fiber and dry matter digestibility) and high seed production have been identified. The Megathyrsus maximus breeding program at the alliance Bioversity-CIAT (Alliance) started in 2016 following simultaneously two breeding schemes (Recurrent Selection based on Specific Combining Ability (RS-SCA) and Reciprocal Recurrent selection (RRS)). To start of RS-SCA scheme, a highly diverse, synthetic, sexual population was created, followed by the establishment of a factorial design using nine apomictic male testers and 30 sexual mothers. The aim of the factorial design was not only to estimate various genetic parameters, but also to identify the best possible apomictic tester with the best Combining Ability. Simultaneously, in order to start the breeding scheme of RRS, two open pollination blocks were established independently, following the heterotic pattern revealed by a population structure study using SSR markers. In the future, we aim to apply simulation based R packages to predict the genetic gain in both scenarios, followed by the validation of the predictions with measurement of genetic gain based on field data, when considering the allocation of resources and logistics required in each scenario

Human papillomavirus E2 regulates SRSF3 (SRp20) to promote capsid protein expression in infected differentiated keratinocytes

The human papillomavirus (HPV) life cycle is tightly linked to differentiation of the infected epithelial cell suggesting a sophisticated interplay between host cell metabolism and virus replication. Previously we demonstrated in differentiated keratinocytes in vitro and in vivo that HPV16 infection caused increased levels of the cellular SR splicing factors (SRSFs) SRSF1 (ASF/SF2), SRSF2 (SC35) and SRSF3 (SRp20). Moreover, the viral E2 transcription and replication factor that is expressed at high levels in differentiating keratinocytes could bind and control activity of the SRSF1 gene promoter. Here we reveal that E2 proteins of HPV16 and HPV31 control expression of SRSFs 1, 2 and 3 in a differentiation-dependent manner. E2 has the greatest trans-activation effect on expression of SRSF3. siRNA depletion experiments in two different models of the HPV16 life cycle (W12E and NIKS16) and one model of the HPV31 life cycle (CIN612-9E) revealed that only SRSF3 contributed significantly to regulation of late events in the virus life cycle. Increased levels of SRSF3 are required for L1 mRNA and capsid protein expression. Capsid protein expression was regulated specifically by SRSF3 and appeared independent of other SRSFs. Taken together these data suggest a significant role of the HPV E2 protein in regulating late events in the HPV life cycle through transcriptional regulation of SRSF3 expression. IMPORTANCE Human papillomavirus replication is accomplished in concert with differentiation of the infected epithelium. Virus capsid protein expression is confined to the upper epithelial layers so as to avoid immune detection. In this study we demonstrate that the viral E2 transcription factor activates the promoter of the cellular SRSF3 RNA processing factor. SRSF3 is required for expression of the E4̂L1 mRNA and so controls expression of the HPV L1 capsid protein. Thus we reveal a new dimension of virus-host interaction crucial for production of infectious virus. SRSF proteins are known drug targets. Therefore, this study provides an excellent basis for developing strategies to regulate capsid protein production in the infected epithelium and production of new virions

Statistical analysis of the gravitational anomaly in {\it Gaia} wide binaries

The exploration of the low acceleration $a<a_{0}$ regime, where $a_{0}=1.2 \times 10^{-10}$m s$^{-1}$ is the acceleration scale of MOND around which gravitational anomalies at galactic scale appear, has recently been extended to the much smaller mass and length scales of local wide binaries thanks to the availability of the {\it Gaia} catalogue. Statistical methods to test the underlying structure of gravity using large samples of such binary stars and dealing with the necessary presence of kinematic contaminants in such samples have also been presented. However, an alternative approach using binary samples carefully selected to avoid any such contaminants, and consequently much smaller samples, has been lacking a formal statistical development. In the interest of having independent high quality checks on the results of wide binary gravity tests, we here develop a formal statistical framework for treating small, clean, wide binary samples in the context of testing modifications to gravity of the form $G \to \gamma G$. The method is validated through extensive tests with synthetic data samples, and applied to recent {\it Gaia} DR3 binary star observational samples of relative velocities and internal separations on the plane of the sky, $v_{2D}$ and $r_{2D}$, respectively. Our final results for a high acceleration $r_{2D}<0.01$pc region are of $\gamma=1.000 \pm 0.096$, in full accordance with Newtonian expectations. For a low acceleration $r_{2D}>0.01$pc region however, we obtain $\gamma=1.512 \pm 0.199$, inconsistent with the Newtonian value of $\gamma=1$ at a $2.6 \sigma$ level, and much more indicative of MOND AQUAL predictions of close to $\gamma=1.4$.Comment: 13 pages, 11 figures, 2 table

Post-growth annealing of GaMnAs under As capping - an alternative way to increase Tc

We demonstrate that in situ post-growth annealing of GaMnAs layers under As capping is adequate for achieving high Curie temperatures (Tc) in a similar way as ex situ annealing in air or in N2 atmosphere practiced earlier.Comment: 13 pages, 4 figure