Characterizing and optimizing a laser-desorption molecular beam source

The design and characterization of a new laser-desorption molecular beam source, tailored for use in x-ray-free-electron-laser and ultrashort-pulse-laser imaging experiments, is presented. It consists of a single mechanical unit containing all source components, including the molecular-beam valve, the sample, and the fiber-coupled desorption laser, which is movable in five axes, as required for experiments at central facilities. Utilizing strong-field ionization, we characterize the produced molecular beam and evaluate the influence of desorption laser pulse energy, relative timing of valve opening and desorption laser, sample bar height, and which part of the molecular packet is probed on the sample properties. Strong-field ionization acts as a universal probe and allows to detect all species present in the molecular beam, and hence enables us to analyze the purity of the produced molecular beam, including molecular fragments. We present optimized experimental parameters for the production of the purest molecular beam, containing the highest yield of intact parent ions, which we find to be very sensitive to the placement of the desorbed-molecules plume within the supersonic expansion

Exploring urban gardening experiences in Europe and Asia: Rome vs. Tokyo

Nowadays the trend of urban gardening can be observed in many parts of the world. This phenomenon responds to the demand of rurality and the requalification of abandoned urban green areas expressed by city residents. Recently, many researchers have investigated about different types of urban gardening but mostly referring to English speaking developed countries (Guitart et al. 2012). To grasp the worldwide trend of urban gardening, this paper aims to compare urban gardening experiences in Rome and Tokyo. In Italy, the analysis is conducted through a direct investigation while the Japanese experience has been analysed through secondary data. The study of these two quite different metropolitan contexts helps to understand: (i) motivations on why urban residents need to grow food by themselves; (ii) types of ecosystem services (i.e. safeguard of agricultural land, food culture, production system, leisure model, environmental education, social cohesion) provided to stakeholders (Langemeyer et al. 2018; Speak et al. 2015). By comparing the two areas in Europe and Asia, we found urban residents’ interests in self-harvesting in common. Yet, there were differences in the form of urban gardening. Urban gardening in Rome is characterized by voluntary community activities, while Tokyo has commercial services to provide opportunities to not only those who have eagerness to grow vegetables, but also those who have less time and skills of growing plants

Impact of Dosing Intervals on Activity of Gentamicin and Ticarcillin Against Pseudomonas aeruginosa in Granulocytopenic Mice

The influence of dosing intervals on the activity of gentamicin and ticarcillin against Pseudomonas aeruginosa was studied in vivo. Granulocytopenic mice infected with P. aeruginosa in the thigh muscle were treated with l-hr or 3-hr injections of gentamicin, ticarcillin, or gentamicin-ticarcillin. Plasma pharmacokinetics of the drugs were correlated with antibacterial activity. Gentamicin injected every 1 hr tended to be less active than gentamicin injected at longer intervals. In contrast, ticarcillin given every 1 hr was significantly more efficacious than equivalent total doses injected every 3 hr. The dosing schedule of gentamicin-ticarcillin was again important for ticarcillin but did not appreciably affect the antibacterial activity of gentamicin. Thus, antimicrobial chemotherapy of P. aeruginosa infections in the granulocytopenic host might be improved by administering ticarcillin rather than gentamicin as a constant infusio

Duality relations between spatial birth-death processes and diffusions in Hilbert space

Spatially dependent birth-death processes can be modelled by kinetic models such as the BBGKY hierarchy. Diffusion in infinite dimensional systems can be modelled with Brownian motion in Hilbert space. In this work Doi field theoretic formalism is utilised to establish dualities between these classes of processes. This enables path integral methods to calculate expectations of duality functions. These are exemplified with models ranging from stochastic cable signalling to jump-diffusion processes