Preliminary designs for X-ray source modifications for the Marshall Space Flight Center's X-ray calibration facility

The objective of this investigation is to develop preliminary designs for modifications to the X-ray source of the MSFC X-Ray Calibration Facility. Recommendations are made regarding: (1) the production of an unpolarized X-ray beam, (2) modification of the source to provide characteristic X-rays with energies up to 40 keV, and (3) addition of the capability to calibrate instruments in the extreme ultraviolet wavelength region

Unified model of ultracold molecular collisions

A scattering model is developed for ultracold molecular collisions, which allows inelastic processes, chemical reactions, and complex formation to be treated in a unified way. All these scattering processes and various combinations of them are possible in ultracold molecular gases, and as such this model will allow the rigorous parametrization of experimental results. In addition we show how, once extracted, these parameters can be related to the physical properties of the system, shedding light on fundamental aspects of molecular collision dynamics.Comment: 16 Pages, 5 Figure

Neglected tropical diseases in the genomics era: re-evaluating the impact of new drugs and mass drug administration.

Simon Croft answers Genome Biology's questions on ways to approach neglected tropical diseases in the genomics era, including re-evaluating the impact of new drugs and mass drug administration

Leishmaniasis: new approaches to disease control.

The leishmaniases afflict the world's poorest populations. Among the two million new cases each year in the 88 countries where the disease is endemic (fig 1), it is estimated that 80% earn less than $2 a day. Human infections with Leishmania protozoan parasites, transmitted via the bite of a sandfly, cause visceral, cutaneous, or mucocutaneous leishmaniasis. The global burden of leishmaniasis has remained stable for some years, causing 2.4 million disability adjusted life years (DALYs) lost and 59 000 deaths in 2001. Neglected by researchers and funding agencies, leishmaniasis control strategies have varied little for decades, but in recent years there have been exciting advances in diagnosis, treatment, and prevention. These include an immunochromatographic dipstick for diagnosing visceral leishmaniasis; the licensing of miltefosine, the first oral drug for visceral leishmaniasis; and evidence that the incidence of zoonotic visceral leishmaniasis in children can be reduced by providing dogs with deltamethrin collars. There is also hope that the first leishmaniasis vaccine will become available within a decade. Here we review these developments and identify priorities for research

Still in My Mind: An Exploration of Practice-led Experimental Research in Progress

The author, an Indigenous woman of mixed heritage, aGurindji/Malgnin/Mudpurra person on her father’s side discusses her practice-led research project, Still in My Mind: Gurindji Experience, Location and Visuality. This project draws inspiration from the words of revered Gurindji elder Vincent Lingiari, profoundly reiterating a deep commitment to his Gurindji/Malgnin peoples and their homelands on Wave Hill in the Northern Territory

Leishmania and other intracellular pathogens: selectivity, drug distribution and PK-PD.

New drugs and treatments for diseases caused by intracellular pathogens, such as leishmaniasis and the Leishmania species, have proved to be some of the most difficult to discover and develop. The focus of discovery research has been on the identification of potent and selective compounds that inhibit target enzymes (or other essential molecules) or are active against the causative pathogen in phenotypic in vitro assays. Although these discovery paradigms remain an essential part of the early stages of the drug R & D pathway, over the past two decades additional emphasis has been given to the challenges needed to ensure that the potential anti-infective drugs distribute to infected tissues, reach the target pathogen within the host cell and exert the appropriate pharmacodynamic effect at these sites. This review will focus on how these challenges are being met in relation to Leishmania and the leishmaniases with lessons learned from drug R & D for other intracellular pathogens

Modified Structured Domain Randomization in a Synthetic Environment for Learning Algorithms

Deep Reinforcement Learning (DRL) has the capability to solve many complex tasks in robotics, self-driving cars, smart grids, finance, healthcare, and intelligent autonomous systems. During training, DRL agents interact freely with the environment to arrive at an inference model. Under real-world conditions this training creates difficulties of safety, cost, and time considerations. Training in synthetic environments helps overcome these difficulties, however, this only approximates real-world conditions resulting in a ‘reality gap’. The synthetic training of agents has proven advantageous but requires methods to bridge this reality gap. This work addressed this through a methodology which supports agent learning. A framework which incorporates a modifiable synthetic environment integrated with an unmodified DRL algorithm was used to train, test, and evaluate agents while using a modified Structured Domain Randomization (SDR+) technique. It was hypothesized that the application of environment domain randomizations (DR) during the learning process would allow the agent to learn variability and adapt accordingly. Experiments using the SDR+ technique included naturalistic and physical-based DR while applying the concept of context-aware elements (CAE) to guide and speed up agent training. Drone racing served as the use case. The experimental framework workflow generated the following results. First, a baseline was established by training and validating an agent in a generic synthetic environment void of DR and CAE. The agent was then tested in environments with DR which showed degradation of performance. This validated the reality gap phenomenon under synthetic conditions and established a metric for comparison. Second, an SDR+ agent was successfully trained and validated under various applications of DR and CAE. Ablation studies determine most DR and CAE effects applied had equivalent effects on agent performance. Under comparison, the SDR+ agent’s performance exceeded that of the baseline agent in every test where single or combined DR effects were applied. These tests indicated that the SDR+ agent’s performance did improve in environments with applied DR of the same order as received during training. The last result came from testing the SDR+ agent’s inference model in a completely new synthetic environment with more extreme and additional DR effects applied. The SDR+ agent’s performance was degraded to a point where it was inconclusive if generalization occurred in the form of learning to adapt to variations. If the agent’s navigational capabilities, control/feedback from the DRL algorithm, and the use of visual sensing were improved, it is assumed that future work could exhibit indications of generalization using the SDR+ technique