Capabilities for Uniqueness and Borrowing

An important application of unique object references is safe and efficient message passing in concurrent object-oriented programming. However, to prevent the ill effects of aliasing, practical systems often severely restrict the shape of messages passed by reference. Moreover, the problematic interplay between destructive reads--often used to implement unique references--and temporary aliasing through "borrowed" references is exacerbated in a concurrent setting, increasing the potential for unpredictable run-time errors. This paper introduces a new approach to uniqueness. The idea is to use capabilities for enforcing both at-most-once consumption of unique references, and a flexible notion of uniqueness. The main novelty of our approach is a model of uniqueness and borrowing based on simple, unstructured capabilities. The advantages are: first, it provides simple foundations for uniqueness and borrowing. Second, it can be formalized using a relatively simple type system, for which we provide a complete soundness proof. Third, it avoids common problems involving borrowing and destructive reads, since unique references subsume borrowed references. We have implemented our type system as an extension to Scala. Practical experience suggests that our system allows type checking real-world actor-based concurrent programs with only a small number of additional type annotations

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Translating the human microbiome

Over the past decade, an explosion of descriptive analyses from initiatives, such as the Human Microbiome Project (HMP) and the MetaHIT project, have begun to delineate the human microbiome. Inhabitants of the intestinal tract, nasal passages, oral cavities, skin, gastrointestinal tract and urogenital tract have been identified using whole genome sequencing, cultivation, metagenomics, metatranscriptomics, metaproteomics and metabolomics. Generation of these data has led to an improved understanding of the contribution of the human microbiome to physiology, health and disease. Nature Biotechnology approached several experts to seek their views on what steps need to be taken to move from descriptive microbiome biology to targeted therapies that tackle diseases in which microbiome dysfunction is a contributory facto

ARCO: a program for Automatic Reduction of CCD Observations

The huge amount of CCD photometric data collected by robotic telescopes (as for instance the ICE-T telescope to be installed at Dome-C) requires a fully automated approach to the reduction and analysis procedures. To this end, we are developing a pipeline, making use of IRAF, DAOPHOTII and tasks build up by us, which will enable to automatically extract differential magnitude time series. Both aperture and PSF photometry methods are used to build a proper sample of comparison stars, with the best method between the two being automatically selected. Finally, the search of rotational periods is performed. To test our package, we present results obtained using a 4-year dataset of a field in the Orion Nebula Cluster (ONC) containing about 350 stars (150 of which turned out to be periodic variables)

Released form of CNTF receptor α component as a soluble mediator of CNTF responses

The α component of the receptor for ciliary neurotrophic factor (CNTF) differs from other known growth factor receptors in that it is anchored to cell membranes by a glycosylphosphatidylinositol linkage. One possible function of this type of linkage is to allow for the regulated release of this receptor component. Cell lines not normally responsive to CNTF responded to treatment with a combination of CNTF and a soluble form of the CNTF α receptor component. These findings not only demonstrate that the CNTF receptor α chain is a required component of the functional CNTF receptor complex but also reveal that it can function in soluble form as part of a heterodimeric ligand. Potential physiological roles for the soluble CNTF receptor are suggested by its presence in cerebrospinal fluid and by its release from skeletal muscle in response to peripheral nerve injury