Safe Construction in Space: Using Swarms of Small Satellites for In-Space Manufacturing

With the emergence of a new space-to-space servicing sector, along with the return of manned missions beyond low earth orbit, there is an increased need for quick, efficient, and most of all, safe Rendezvous and Proximity Operations (RPO). An additional next big step forward may be true manufacturing in space, which could take advantage of swarms of small satellites cooperating in close proximity to each other, all subjected to the same laws of orbital mechanics. Currently, there is a lack of knowledge about how to safely operate a swarm of spacecraft in close quarters in a dynamically changing environment (i.e., a “space construction site”), without creating a high risk of collision and/or potential debris creation. In order to formulate a stable, recurring, and efficient set of trajectories, a method was developed using genetic algorithms. This set of algorithms is able to solve for a set of relative motion trajectories for a swarm of N spacecraft, taking into account gravitational perturbations, to obtain trajectories that are recurring over a set amount of time. These algorithms also have the capability to dynamically alter the trajectories in order to take into account changes to the system, such as the addition of new spacecraft, or individual spacecraft failures

The Arkisys Port Module: An Orbital Platform for Hosted Payloads in Low-Earth Orbit

Advances in Small Satellite technology combined with the availability of low-cost rideshares to Low-Earth Orbit (LEO) have led to an increasing number of space missions. However, the underlying technology for small payload missions has been relatively constant over the past two decades: CubeSat form factor platforms for free-flying missions in LEO. Arkisys is working to change this, and allow a wider variety of payloads to reach LEO which don\u27t include an immediate free-flying requirement. This platform is called The Port, and is an autonomous long-duration orbital platform for a multitude of uses, including hosting payloads in LEO. Currently, avenues available to test small experimental payloads in LEO are hosted inside other satellites, or in some cases aboard the International Space Station (ISS) at the ISS National Laboratory. While CubeSats are quite ubiquitous and widely available; the downside is that while they appear low cost, they can be costly for a team who has never developed one before. New companies hosting payloads for customers offer a way to get to space for a limited duration, some even offering to bring them back to Earth. The ISS National Laboratory can support a wider variety of payloads than small satellites alone; however, there is a limited capacity on the ISS, and the missions are limited by human factor constraints. For researchers and commercial developers who want to run small-scale experiments on orbit, on the order of 10 - 200 kg, a long-duration robotic platform which can host these payloads, providing power, data, and thermal control over a standardized docking interface presents a unique opportunity to expand their functional test and operations. On a long duration platform payloads can be situated in an orientation that provides a constant view of the Earth, of deep space, or even a radiation-shielded environment. With a large enough number of payloads on board running at a duty cycle, the per-user cost is able to be brought significantly lower than a one-off small satellite mission for an equivalently sized payload. There is a interesting dichotomy in the use of Cubesat/Small Satellites to support payload testing; the value proposition is typically in building a satellite to last for multiple years, yet many payloads are Technology Readiness Level (TRL) raising demonstrations that only need to run for a matter of months. This results in a potential under-utilization of resources of the satellite. A long-duration platform optimized to allow for any level of maturity of a technology or payload that needs testing on orbit is able to amortize the cost of operation over time and numbers of customers, helping to drive cost down with increased utility and functions passed on to the payload consumer. This paper puts forward Arkisys\u27s alternative approach to hosting new technologies and missions into space that does not require a full satellite to be built and launched, and describes in detail the capabilities and benefits of the Arkisys Port platform as a long-duration orbital platforms to serve short- and medium-term missions to LEO. The goal is to offload some of the existing payload and new technology backlog from the existing methods to accelerate innovation in space technology today

Glaucoma detection: the content of optometric eye examinations for a presbyopic patient of African racial descent

Aims: Standardised patient (SP) methodology is the gold standard for evaluating clinical practice. We investigated the content of optometric eyecare for an early presbyopic SP of African racial descent, an “at-risk” patient group for primary open-angle glaucoma (POAG). Methods: A trained actor presented unannounced as a 44-year-old patient of African racial descent, complaining of recent near vision difficulties, to 100 community optometrists for an audio-recorded eye examination. The eye examinations were subsequently assessed via a checklist based on evidence-based POAG reviews, clinical guidelines and expert panel opinion. Results: Ninety-five per cent of optometrists carried out optic disc assessment and tonometry, which conforms to the UK College of Optometrists’ advice that those patients aged >40 years should receive at least two of the following tests: tonometry, optic disc assessment, visual field testing. Thirty-five per cent of optometrists carried out all of these tests and 6% advised the SP of increased POAG risk in those of African racial descent. Conclusion: SP encounters are an effective measure of optometric clinical practice. As in other healthcare disciplines, there are substantial differences between optometrists in the depth of their clinical investigations, challenging the concept of a “standard sight test”. There is a need for continuing professional development (CPD) in glaucoma screening, in which the increased risk of POAG in those of African racial descent should be emphasised

Are some brain injury patients improving more than ohers?

Predicting the evolution of individuals is a rather new mining task with applications in medicine. Medical researchers are interested in the progress of a disease and in the evolution of individuals subjected to treatment. We investigate the evolution of patients on the basis of medical tests before and during treatment after brain trauma: we want to understand how similar patients can become to healthy participants. We face two challenges. First, we have less information on healthy participants than on the patients. Second, the values of the medical tests for patients, even after treatment started, remain well-separated from those of healthy people; this is typical for neurodegenerative diseases, but also for further brain impairments. Our approach encompasses methods for modelling patient evolution and for predicting the health improvement of different patient subpopulations, dealing with the above challenges. We test our approach on a cohort of patients treated after brain trauma and a corresponding cohort of controls

Melanoma in Buckinghamshire: Data from the Inception of the Skin Cancer Multidisciplinary Team

Background. Melanoma incidence is increasing faster than any other cancer in the UK. The introduction of specialist skin cancer multidisciplinary teams intends to improve the provision of care to patients suffering from melanoma. This study aims to investigate the management and survival of patients diagnosed with melanoma around the time of inception of the regional skin cancer multidisciplinary team both to benchmark the service against published data and to enable future analysis of the impact of the specialisation of skin cancer care. Methods. All patients diagnosed with primary cutaneous melanoma between January 1, 2003 and December 3, 2005 were identified. Data on clinical and histopathological features, surgical procedures, complications, disease recurrence and 5-year survival were collected and analysed. Results. Two hundred and fourteen patients were included, 134 female and 80 males. Median Breslow thickness was 0.74 mm (0.7 mm female and 0.8 mm male). Overall 5-year survival was 88% (90% female and 85% male). Discussion. Melanoma incidence in Buckinghamshire is in keeping with published data. Basic demographics details concur with classic melanoma distribution and more recent trends, with increased percentage of superficial spreading and thin melanomas, leading to improved survival are reflected

Data mining applied to the cognitive rehabilitation of patients with acquired brain injury

Acquired brain injury (ABI) is one of the leading causes of death and disability in the world and is associated with high health care costs as a result of the acute treatment and long term rehabilitation involved. Different algorithms and methods have been proposed to predict the effectiveness of rehabilitation programs. In general, research has focused on predicting the overall improvement of patients with ABI. The purpose of this study is the novel application of data mining (DM) techniques to predict the outcomes of cognitive rehabilitation in patients with ABI. We generate three predictive models that allow us to obtain new knowledge to evaluate and improve the effectiveness of the cognitive rehabilitation process. Decision tree (DT), multilayer perceptron (MLP) and general regression neural network (GRNN) have been used to construct the prediction models. 10-fold cross validation was carried out in order to test the algorithms, using the Institut Guttmann Neurorehabilitation Hospital (IG) patients database. Performance of the models was tested through specificity, sensitivity and accuracy analysis and confusion matrix analysis. The experimental results obtained by DT are clearly superior with a prediction average accuracy of 90.38%, while MLP and GRRN obtained a 78.7% and 75.96%, respectively. This study allows to increase the knowledge about the contributing factors of an ABI patient recovery and to estimate treatment efficacy in individual patients

Ancestral Polymorphisms Shape the Adaptive Radiation of Metrosideros across the Hawaiian Islands

Some of the most spectacular adaptive radiations begin with founder populations on remote islands. How genetically limited founder populations give rise to the striking phenotypic and ecological diversity characteristic of adaptive radiations is a paradox of evolutionary biology. We conducted an evolutionary genomics analysis of genus Metrosideros, a landscape-dominant, incipient adaptive radiation of woody plants that spans a striking range of phenotypes and environments across the Hawaiian Islands. Using nanopore-sequencing, we created a chromosome-level genome assembly for Metrosideros polymorpha var. incana and analyzed whole-genome sequences of 131 individuals from 11 taxa sampled across the islands. Demographic modeling and population genomics analyses suggested that Hawaiian Metrosideros originated from a single colonization event and subsequently spread across the archipelago following the formation of new islands. The evolutionary history of Hawaiian Metrosideros shows evidence of extensive reticulation associated with significant sharing of ancestral variation between taxa and secondarily with admixture. Taking advantage of the highly contiguous genome assembly, we investigated the genomic architecture underlying the adaptive radiation and discovered that divergent selection drove the formation of differentiation outliers in paired taxa representing early stages of speciation/divergence. Analysis of the evolutionary origins of the outlier single nucleotide polymorphisms (SNPs) showed enrichment for ancestral variations under divergent selection. Our findings suggest that Hawaiian Metrosideros possesses an unexpectedly rich pool of ancestral genetic variation, and the reassortment of these variations has fueled the island adaptive radiation

Longitudinal Changes of Fixation Location and Stability Within 12 Months in Stargardt Disease: ProgStar Report No. 12

Purpose: To investigate the natural history of Stargardt disease (STGD1) using fixation location and fixation stability. // Design: Multicenter, international, prospective cohort study. // Methods: Fixation testing was performed using the Nidek MP-1 microperimeter as part of the prospective, multicenter, natural history study on the Progression of Stargardt disease (ProgStar). A total of 238 patients with ABCA4-related STGD1 were enrolled at baseline (bilateral enrollment in 86.6%) and underwent repeat testing at months 6 and 12. // Results: Outcome measures included the distance of the preferred retinal locus from the fovea (PRL) and the bivariate contour ellipse area (BCEA). After 12 months of follow-up, the change in the eccentricity of the PRL from the anatomic fovea was −0.0014 degrees (95% confidence interval [CI], −0.27 degrees, 0.27 degrees; P = .99). The deterioration in the stability of fixation as expressed by a larger BCEA encompassing 1 standard deviation of all fixation points was 1.21 degrees squared (deg2) (95% CI, −1.23 deg2, 3.65 deg2; P = .33). Eyes with increases and decreases in PRL eccentricity and/or BCEA values were observed. // Conclusions: Our observations point to the complexity of fixation parameters. The association of increasingly eccentric and unstable fixation with longer disease duration that is typically found in cross-sectional studies may be countered within individual patients by poorly understood processes like neuronal adaptation. Nevertheless, fixation parameters may serve as useful secondary outcome parameters in selected cases and for counseling patients to explain changes to their visual functionality

Fenofibrate in the management of AbdoMinal aortic anEurysm (FAME): Study protocol for a randomised controlled trial

Background: Abdominal aortic aneurysm (AAA) is a slowly progressive destructive process of the main abdominal artery. Experimental studies indicate that fibrates exert beneficial effects on AAAs by mechanisms involving both serum lipid modification and favourable changes to the AAA wall. Methods/design: Fenofibrate in the management of AbdoMinal aortic anEurysm (FAME) is a multicentre, randomised, double-blind, placebo-controlled clinical trial to assess the effect of orally administered therapy with fenofibrate on key pathological markers of AAA in patients undergoing open AAA repair. A total of 42 participants scheduled for an elective open AAA repair will be randomly assigned to either 145 mg of fenofibrate per day or identical placebo for a minimum period of 2 weeks prior to surgery. Primary outcome measures will be macrophage number and osteopontin (OPN) concentration within the AAA wall as well as serum concentrations of OPN. Secondary outcome measures will include levels of matrix metalloproteinases and proinflammatory cytokines within the AAA wall, periaortic fat and intramural thrombus and circulating concentrations of AAA biomarkers. Discussion: At present, there is no recognised medical therapy to limit AAA progression. The FAME trial aims to assess the ability of fenofibrate to alter tissue markers of AAA pathology. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12612001226897. Registered on 20 November 2012. © 2017 The Author(s)