Scenarios for optimizing potato productivity in a lunar CELSS

The use of controlled ecological life support system (CELSS) in the development and growth of large-scale bases on the Moon will reduce the expense of supplying life support materials from Earth. Such systems would use plants to produce food and oxygen, remove carbon dioxide, and recycle water and minerals. In a lunar CELSS, several factors are likely to be limiting to plant productivity, including the availability of growing area, electrical power, and lamp/ballast weight for lighting systems. Several management scenarios are outlined in this discussion for the production of potatoes based on their response to irradiance, photoperiod, and carbon dioxide concentration. Management scenarios that use 12-hr photoperiods, high carbon dioxide concentrations, and movable lamp banks to alternately irradiate halves of the growing area appear to be the most efficient in terms of growing area, electrical power, and lamp weights. However, the optimal scenario will be dependent upon the relative 'costs' of each factor

A New Approach to Canonical Quantization of the Radiation Damping

Inspired in some works about quantization of dissipative systems, in particular of the damped harmonic oscillator\cite{MB,RB,12}, we consider the dissipative system of a charge interacting with its own radiation, which originates the radiation damping (RD). Using the indirect Lagrangian representation we obtained a Lagrangian formalism with a Chern-Simons-like term. A Hamiltonian analysis is also done, what leads to the quantization of the system.Comment: 5 page

Pencil beam characteristics of the next-generation proton scanning gantry of PSI: design issues and initial commissioning results

In this paper we report on the main design features, on the realization process and on selected first results of the initial commissioning of the new Gantry 2 of PSI for the delivery of proton therapy with new advanced pencil beam scanning techniques. We present briefly the characteristics of the new gantry system with main emphasis on the beam optics, on the characterization of the pencil beam used for scanning and on the performance of the scanning system. The idea is to give an overview of the major components of the whole system. The main long-term technical goal of the new equipment of Gantry 2 is to expand the use of pencil beam scanning to the whole spectrum of clinical indications including moving targets. We report here on the initial experience and problems encountered in the development of the system with selected preliminary results of the ongoing commissioning of Gantry

The Astroculture (tm)-1 experiment on the USML-1 mission

Permanent human presence in space will require a life support system that minimizes athe need for resupply of consumables from Earth resources. Plants that convert radiant energy to chemical energy via photosynthesis are a key component of a bioregenerative life support system. Providing the proper root environment for plants in reduced gravity is an essential aspect of the development of facilities for growing plants in a space environment. The ASTROCULTURE(TM)-1 experiment, included in the USML-1 mission, successfully demonstrated the ability of the Wisconsin Center for Space Automation and Robotics porous tube water delivery system to control water movement through a rooting matrix in a microgravity environment

Positron production in multiphoton light-by-light scattering

A signal of 106 {+-} 14 positrons above background has been observed in collisions of a low-emittance 46.6-GeV electron beam with terawatt pulses from a Nd:glass laser at 527 nm wavelength in an experiment at the Final Focus Test Beam at SLAC. Peak laser intensities of {approximately} 1.3 {times} 10{sup 18} W/cm{sup 2} have been achieved corresponding to a value of 0.3 for the parameter {Upsilon} = {var_epsilon}*/{var_epsilon}{sub crit} where {var_epsilon}* = 2{gamma}{var_epsilon}{sub lab} is the electric field strength of the laser transformed to the rest frame of the electron beam and {var_epsilon}{sub crit} = m{sup 2}c{sup 3}/e{bar h} = 1.3 {times} 10{sup 16} V/cm is the QED critical field strength. The positrons are interpreted as arising from a two-step process in which laser photons are backscattered to GeV energies by the electron beam followed by a collision between the high-energy photon and several laser photons to produce an electron-positron pair. These results are the first laboratory evidence for a light-by-light scattering process involving only real photons

Factors associated with going outdoors frequently: a cross-sectional study among Swiss community-dwelling older adults.

This study examines potential risk and protective factors associated with going outdoors frequently among older persons, and whether these factors vary according to physical limitations. Cross-sectional analysis. Community-dwelling participants of the Lausanne cohort Lc65+ in 2016, aged 68-82 years (n=3419). Associations between going outdoors frequently and physical limitations, sociodemographic, health, psychological and social variables were examined using logistic regression models. Subgroup analyses were performed according to the severity of physical limitations. 'Going outdoors frequently' was defined as going out ≥5 days/week and not spending most of the time sitting or lying down. Three in four (73.9%) participants reported going outdoors frequently. Limitations in climbing stairs (adjusted OR (AdjOR) 0.61, 95% CI 0.47 to 0.80) and walking (AdjOR 0.24, 95% CI 0.18 to 0.31), as well as depressive symptoms (AdjOR 0.58, 95% CI 0.47 to 0.70), dyspnoea (AdjOR 0.60, 95% CI 0.48 to 0.75), age (AdjOR <sub>older age group</sub> 0.73, 95% CI 0.59 to 0.92) and fear of falling (AdjOR 0.75, 95% CI 0.62 to 0.91) reduced the odds of going outdoors frequently. In contrast, living alone (AdjOR 1.30, 95% CI 1.08 to 1.56), reporting a dense (AdjOR 1.57, 95% CI 1.26 to 1.96) and a high-quality (AdjOR 1.28, 95% CI 1.06 to 1.53) social network increased the odds of going outdoors frequently. Among participants with severe limitations, 44.6% still went outdoors frequently. Among this subgroup, a new emotional relationship (AdjOR 2.52, 95% CI 1.18 to 5.38) was associated with going outdoors, whereas cognitive complaints (AdjOR 0.66, 95% CI 0.47 to 0.93), urinary incontinence (AdjOR 0.67, 95% CI 0.46 to 0.97), dyspnea (AdjOR:0.67, 95%CI:0.48-0.93), and depressive symptoms (AdjOR 0.67, 95% CI 0.48 to 0.93) lowered the odds of going outdoors. Physical limitations are associated with decreased odds of going outdoors frequently. However, social characteristics appear to mitigate this association, even among older persons with severe limitations. Further studies are needed to determine causality and help guide interventions to promote going outdoors as an important component of active ageing

Temporal changes in importance of quality of life domains: a longitudinal study in community-dwelling Swiss older people.

Population aging is a global phenomenon requiring interventions to improve quality of life (QoL), a subjective and dynamic concept. Such interventions should be based on QoL domains considered as important from older people's viewpoint. It is unclear whether and how much these domains may vary over time as people age. This study aims to assess the importance of QoL domains, their pattern and determinants of change among the non-institutionalized older population over a 5-year period. This longitudinal study included community-dwelling older adults (N = 1947, aged 68-77 years at baseline) from the Lausanne cohort 65+. In 2011 and 2016, participants rated the importance of 28 QoL items in seven domains. The difference between scores (0-100) of importance attributed to each QoL domain between two assessments was calculated and used as a dependent variable to assess the associations with covariates in multivariable analysis for each domain. Importance scores slightly but significantly decreased in five of the seven QoL domains. Despite the majority of participants did not modify their ranking of importance for each QoL domain between the two time points, the proportion of change was still substantial. Bivariate and multivariable analyses showed that education and to a lesser extent age, living arrangement and morbidity, were associated with decrease in the importance of specific QoL domains; characteristics indicating vulnerability (e.g., low education or morbidity) were associated with a decline in the importance. Although aging individuals modified the importance they give to the seven QoL domains, at population level, changes in opposite directions overall resulted in only small decline; importance seems less stable over time among individuals with vulnerable sociodemographic and health profiles