The Challenges to Mission and Ministry in the COVID-19 Moment in Jesuit Higher Education

In this Reflection, Father Bosco examines the adaptations and adjustments made at Georgetown University as students, faculty and staff managed with the impact of the coronavirus

The reaction NH2 + PH3 yields NH3 + PH2: Absolute rate constant measurement and implication for NH3 and PH3 photochemistry in the atmosphere of Jupiter

The rate constant is measured over the temperature interval 218-456 K using the technique of flash photolysis-laser-induced fluorescence. NH2 radicals are produced by the flash photolysis of ammonia highly diluted in argon, and the decay of fluorescent NH2 photons is measured by multiscaling techniques. For each of the five temperatures employed in the study, the results are shown to be independent of variations in PH3 concentration, total pressure (argon), and flash intensity. It is found that the rate constant results are best represented for T between 218 and 456 K by the expression k = (1.52 + or - 0.16) x 10 to the -12th exp(-928 + or - 56/T) cu cm per molecule per sec; the error quoted is 1 standard deviation. This is the first determination of the rate constant for the reaction NH2 + PH3. The data are compared with an estimate made in order to explain results of the radiolysis of NH3-PH3 mixtures. The Arrhenius parameters determined here for NH2 + PH3 are then constrasted with those for the corresponding reactions of H and OH with PH3

Effects of Hypohydration on Work Performance and Tolerance to plus Gz Acceleration in Man

Hypohydration effects on work performance and tolerance to acceleration stress in ma

Effects of acute and chronic hypohydration on tolerance to plus Gz acceleration in man. I - Physiological results

Effects of acute and chronic hypohydration on human physiological tolerance to gravity acceleratio

Classical and quantum coupled oscillators: symplectic structure

We consider a set of N linearly coupled harmonic oscillators and show that the diagonalization of this problem can be put in geometrical terms. The matrix techniques developed here allowed for solutions in both the classical and quantum regimes.Comment: 27 pages, 6 figure

Realization of the farad from the dc quantum Hall effect with digitally-assisted impedance bridges

A new traceability chain for the derivation of the farad from dc quantum Hall effect has been implemented at INRIM. Main components of the chain are two new coaxial transformer bridges: a resistance ratio bridge, and a quadrature bridge, both operating at 1541 Hz. The bridges are energized and controlled with a polyphase direct-digital-synthesizer, which permits to achieve both main and auxiliary equilibria in an automated way; the bridges and do not include any variable inductive divider or variable impedance box. The relative uncertainty in the realization of the farad, at the level of 1000 pF, is estimated to be 64E-9. A first verification of the realization is given by a comparison with the maintained national capacitance standard, where an agreement between measurements within their relative combined uncertainty of 420E-9 is obtained.Comment: 15 pages, 11 figures, 3 table

Artificially induced autopolyploidy increases genome-wide methylation in grapevine.

Epigenetic processes are reversible chemical modifications acting on two genetic information-containing targets: DNA, and histones

Analysis and modelling of muscles motion during whole body vibration

The aim of the study is to characterize the local muscles motion in individuals undergoing whole body mechanical stimulation. In this study we aim also to evaluate how subject positioning modifies vibration dumping, altering local mechanical stimulus. Vibrations were delivered to subjects by the use of a vibrating platform, while stimulation frequency was increased linearly from 15 to 60Hz. Two different subject postures were here analysed. Platform and muscles motion were monitored using tiny MEMS accelerometers; a contra lateral analysis was also presented. Muscle motion analysis revealed typical displacement trajectories: motion components were found not to be purely sinusoidal neither in phase to each other. Results also revealed a mechanical resonant-like behaviour at some muscles, similar to a second-order system response. Resonance frequencies and dumping factors depended on subject and his positioning. Proper mechanical stimulation can maximize muscle spindle solicitation, which may produce a more effective muscle activation

Improving in vitro induction of autopolyploidy in grapevine seedless cultivars.

The efficiency of in vitro polyploidization depends on several variables associated to the plant, the antimicrotubule agent and the interactions between them. In the present work, we have used response-surface methodology to determine the best operating conditions for plant recovery in polyploidization assays for shoot apices and somatic embryos of two seedless grape cultivars, employing colchicine and oryzalin. Explant type, tubulin-interfering compound and concentration were the critical factors determining plant recovery. Linear reduction in viable plant regeneration via organogenesis and somatic embryogenesis was obtained by increasing oryzalin concentrations and treatment time, whereas the effects of colchicine were better described by a quadratic design for both explants types. The conditions promoting higher rates of plant recovery were used in chromosome doubling experiments with oryzalin and colchicine for shoot apices and somatic embryos of ?Crimson seedless? and ?BRS Clara?. The established protocols allowed the recovery of non-chimerical autotetraploid plants at rates higher than 30 % for both cultivars. Stomata size parameters statistically correlate to the ploidy level of the regenerants and were effective for preliminary polyploidy screening. Autotetraploid lines of seedless grapes were incorporated into the Vitis germplasm bank for further agronomical evaluations. To our knowledge, this is the first report of in vitro oryzalin induced polyploidization of grapevine and of the use of mathematical modeling to optimize chromosome doubling in plants