Video sensor with range measurement capability

A video sensor device is provided which incorporates a rangefinder function. The device includes a single video camera and a fixed laser spaced a predetermined distance from the camera for, when activated, producing a laser beam. A diffractive optic element divides the beam so that multiple light spots are produced on a target object. A processor calculates the range to the object based on the known spacing and angles determined from the light spots on the video images produced by the camera

Millimeter-wave Signature of Strange Matter Stars

One of the most important questions in the study of compact objects is the nature of pulsars, including whether they consist of neutron matter or strange quark matter (SQM). However, few mechanisms for distinguishing between these two possibilities have been proposed. The purpose of this paper is to show that a strange star (one made of SQM) will have a vibratory mode with an oscillation frequency of approximately 250 GHz (millimeter wave). This mode corresponds to motion of the center of the expected crust of normal matter relative to the center of the strange quark core, without distortion of either. Radiation from currents generated in the crust at the mode frequency would be a SQM signature. We also consider effects of stellar rotation, estimate power emission and signal-to-noise ratio, and discuss briefly possible mechanisms for exciting the mode.Comment: 13 pages, Latex, one figur

Microplastic ingestion ubiquitous in marine turtles

Despite concerns regarding the environmental impacts of microplastics, knowledge of the incidence and levels of synthetic particles in large marine vertebrates is lacking. Here, we utilize an optimized enzymatic digestion methodology, previously developed for zooplankton, to explore whether synthetic particles could be isolated from marine turtle ingesta. We report the presence of synthetic particles in every turtle subjected to investigation (n = 102) which included individuals from all seven species of marine turtle, sampled from three ocean basins (Atlantic [ATL]: n = 30, four species; Mediterranean (MED): n = 56, two species; Pacific (PAC): n = 16, five species). Most particles (n = 811) were fibres (ATL: 77.1% MED: 85.3% PAC: 64.8%) with blue and black being the dominant colours. In lesser quantities were fragments (ATL: 22.9%: MED: 14.7% PAC: 20.2%) and microbeads (4.8%; PAC only; to our knowledge the first isolation of microbeads from marine megavertebrates). Fourier transform infrared spectroscopy (FT‐IR) of a subsample of particles (n = 169) showed a range of synthetic materials such as elastomers (MED: 61.2%; PAC: 3.4%), thermoplastics (ATL: 36.8%: MED: 20.7% PAC: 27.7%) and synthetic regenerated cellulosic fibres (SRCF; ATL: 63.2%: MED: 5.8% PAC: 68.9%). Synthetic particles being isolated from species occupying different trophic levels suggest the possibility of multiple ingestion pathways. These include exposure from polluted seawater and sediments and/or additional trophic transfer from contaminated prey/forage items. We assess the likelihood that microplastic ingestion presents a significant conservation problem at current levels compared to other anthropogenic threats

Detection of intrinsic source structure at ~3 Schwarzschild radii with Millimeter-VLBI observations of SAGITTARIUS A*

We report results from very long baseline interferometric (VLBI) observations of the supermassive black hole in the Galactic center, Sgr A*, at 1.3 mm (230 GHz). The observations were performed in 2013 March using six VLBI stations in Hawaii, California, Arizona, and Chile. Compared to earlier observations, the addition of the APEX telescope in Chile almost doubles the longest baseline length in the array, provides additional {\it uv} coverage in the N-S direction, and leads to a spatial resolution of $\sim$30 $\mu$as ($\sim$3 Schwarzschild radii) for Sgr A*. The source is detected even at the longest baselines with visibility amplitudes of $\sim$4-13% of the total flux density. We argue that such flux densities cannot result from interstellar refractive scattering alone, but indicate the presence of compact intrinsic source structure on scales of $\sim$3 Schwarzschild radii. The measured nonzero closure phases rule out point-symmetric emission. We discuss our results in the context of simple geometric models that capture the basic characteristics and brightness distributions of disk- and jet-dominated models and show that both can reproduce the observed data. Common to these models are the brightness asymmetry, the orientation, and characteristic sizes, which are comparable to the expected size of the black hole shadow. Future 1.3 mm VLBI observations with an expanded array and better sensitivity will allow a more detailed imaging of the horizon-scale structure and bear the potential for a deep insight into the physical processes at the black hole boundary.Comment: 11 pages, 5 figures, accepted to Ap

Bacterial Signatures of Paediatric Respiratory Disease : An Individual Participant Data Meta-Analysis

Introduction: The airway microbiota has been linked to specific paediatric respiratory diseases, but studies are often small. It remains unclear whether particular bacteria are associated with a given disease, or if a more general, non-specific microbiota association with disease exists, as suggested for the gut. We investigated overarching patterns of bacterial association with acute and chronic paediatric respiratory disease in an individual participant data (IPD) meta-analysis of 16S rRNA gene sequences from published respiratory microbiota studies.Methods: We obtained raw microbiota data from public repositories or via communication with corresponding authors. Cross-sectional analyses of the paediatric (10 case subjects were included. Sequence data were processed using a uniform bioinformatics pipeline, removing a potentially substantial source of variation. Microbiota differences across diagnoses were assessed using alpha- and beta-diversity approaches, machine learning, and biomarker analyses.Results: We ultimately included 20 studies containing individual data from 2624 children. Disease was associated with lower bacterial diversity in nasal and lower airway samples and higher relative abundances of specific nasal taxa including Streptococcus and Haemophilus. Machine learning success in assigning samples to diagnostic groupings varied with anatomical site, with positive predictive value and sensitivity ranging from 43 to 100 and 8 to 99%, respectively.Conclusion: IPD meta-analysis of the respiratory microbiota across multiple diseases allowed identification of a non-specific disease association which cannot be recognised by studying a single disease. Whilst imperfect, machine learning offers promise as a potential additional tool to aid clinical diagnosis.Peer reviewe

Contemporary review of risk-stratified management in acute uncomplicated and complicated diverticulitis

BACKGROUND: Acute colonic diverticulitis is a common clinical condition. Severity of the disease is based on clinical, laboratory, and radiological investigations and dictates the need for medical or surgical intervention. Recent clinical trials have improved the understanding of the natural history of the disease resulting in new approaches to and better evidence for the management of acute diverticulitis. METHODS: We searched the Cochrane Library (years 2004-2015), MEDLINE (years 2004-2015), and EMBASE (years 2004-2015) databases. We used the search terms "diverticulitis, colonic" or "acute diverticulitis" or "divertic*" in combination with the terms "management," "antibiotics," "non-operative," or "surgery." Registers for clinical trials (such as the WHO registry and the https://clinicaltrials.gov/) were searched for ongoing, recruiting, or closed trials not yet published. RESULTS: Antibiotic treatment can be avoided in simple, non-complicated diverticulitis and outpatient management is safe. The management of complicated disease, ranging from a localized abscess to perforation with diffuse peritonitis, has changed towards either percutaneous or minimally invasive approaches in selected cases. The role of laparoscopic lavage without resection in perforated non-fecal diverticulitis is still debated; however, recent evidence from two randomised controlled trials has found a higher re-intervention in this group of patients. CONCLUSIONS: A shift in management has occurred towards conservative management in acute uncomplicated disease. Those with uncomplicated acute diverticulitis may be treated without antibiotics. For complicated diverticulitis with purulent peritonitis, the use of peritoneal lavage appears to be non-superior to resection