Haemostatic function and cerebrovascular disease

Early clinical progression of ischaemic stroke is common and is associated with increased risk of death and dependency. It was hypothesised that activation of the coagulation system may be an important contributor in early cases of deterioration. A study was designed with the aim of characterising alterations in circulating haemostatic markers in patients with progressing stroke. A number of validation projects were also undertaken around this main study. Consecutive acute ischaemic stroke admissions were recruited to the haemostasis in\ progressing ischaemic stroke study and had haemostatic markers measured within 24 hours of symptom recognition. Fifty four (25%) of the 219 patients recruited met criteria for progressing stroke. Prothrombin fragments 1+2 (Fl+2)(median 1.28 v. 1.06 nmol/1, p=0.01), thrombin-antithrombin complex (TAT)(5.28 v. 4.07 mug/1, p<0.01), D-dimer (443 V. 194 ng/ml, p<0.001) and von Willebrand factor (216 v. 198 iu/dl, p<0.05) levels were higher in these patients than stable/ improving patients. In logistic regression analysis, with all important clinical and laboratory variables included, only natural log D-dimer (odds ratio 1.88, p=0.0001) and mean arterial blood pressure (odds ratio 1.26 per 10 mmHg change, p=0.01) remained independent predictors of progressing stroke. In conclusion, there is evidence of excess thrombin generation and fibrin turnover in patients with progressing ischaemic stroke. Further research is required to determine whether such patients benefit from acute interventions aimed at modifying haemostatic function. Atrial fibrillation (AF) is associated with cognitive impairment and dementia. It was hypothesised that haemostatic function is altered in subjects with AF who develop dementia, and that long-term warfarin anticoagulation is protective against cognitive decline. Recruitment was from an observational cohort study of AF. Cognitive function was assessed using both a telephone interview and an informant questionnaire. In 218 subjects assessed D-dimer, Fl+2 and TAT levels were higher in AF subjects with dementia compared to those without (geometric means 97.1 v. 62.0 ng/ml, p=0.008; 0.74 v. 0.53 nmol/1, p=0.006; and medians 1.78 v. 1.44 mug/l, p=0.003 respectively). Dementia was less common in those treated with warfarin; 18%, v. 32%, p=0.023. In conclusion, the results were consistent with increased thrombin generation and fibrin turnover in subjects with AF and dementia compared to those without dementia

High Gene Flow Due to Pelagic Larval Dispersal Among South Pacific Archipelagos in Two Amphidromous Gastropods (Neritomorpha: Neritidae)

The freshwater stream fauna of tropical oceanic islands is dominated by amphidromous species, whose larvae are transported to the ocean and develop in the plankton before recruiting back to freshwater habitat as juveniles. Because stream habitat is relatively scarce and unstable on oceanic islands, this life history would seem to favor either the retention of larvae to their natal streams, or the ability to delay metamorphosis until new habitat is encountered. To distinguish between these hypotheses, we used population genetic methods to estimate larval dispersal among five South Pacific archipelagos in two amphidromous species of Neritid gastropod (Neritina canalis and Neripteron dilatatus). Sequence data from mitochondrial COI revealed that neither species is genetically structured throughout the Western Pacific, suggesting that their larvae have a pelagic larval duration of at least eight weeks, longer than many marine species. Additionally, the two species have recently colonized isolated Central Pacific archipelagos in three independent events. Since colonization, there has been little to no gene flow between the Western and Central Pacific archipelagos in Neritina canalis, and high levels of gene flow across the same region in Neripteron dilatatus. Both species show departures from neutrality and recent dates for colonization of the Central Pacific archipelagos consistent with frequent extinction and recolonization of stream populations in this area. Similar results from other amphidromous species suggest that unstable freshwater habitats promote long-distance dispersal capabilities

Population ageing and health financing: A method for forecasting two sides of the same coin

There is a perception that population ageing will have deleterious effects on future health financing sustainability. We propose a new method—the Population Ageing financial Sustainability gap for Health systems (or alternatively, the PASH)—to explore how changes in the population age mix will affect health expenditures and revenues. Using a set of six anonymized country scenarios that are based on data from countries in Europe and the Western Pacific representing a diverse range of health financing systems, we forecast the size of the ageing-attributable gap between health revenues and expenditures from 2020 to 2100 under current health financing arrangements. In the country with the largest financing gap in 2100 (country S6) the majority (87.1%) is caused by growth in health expenditures. However in countries that are heavily reliant on labour-market related social contributions to finance health care, a sizeable share of the financing gap is due to reductions in health revenues. We argue that analyses giving equal attention to both health expenditures and revenues steers decision makers towards a more balanced set of policy options to address the challenges of population ageing, ranging from targeting expenditures and utilization of services to diversifying revenue

Moodlegate: securing computer driven exam environments

Moodle installations that are used to make assessments inevitably run the risk of being used to obtain fraudulent results by the students. Such fraud can be mitigated through the use of auditing tools that detect abnormal behaviour, but students continue to attempt to cheat the system despite theknowledge that these tools are active. This article presents a tool that blocks a range of behaviours which could be used by students fraudulently. This result is achieved by implementing access control to any Moodle deployment. The access control is based on the identity of the Moodle user, time and date, computer (or range of computers), and the Moodle resources that are being accessed. Byintegrating with Moodle, the tool is able to provide a finer level of access control than would be provided by traditional network access control devices such as firewalls. This increases the assurance that the results of Moodle driven exam assessments are accurate

Mobile Robot Navigation in Indoor Environments: Geometric, Topological, and Semantic Navigation

The objective of the chapter is to show current trends in robot navigation systems related to indoor environments. Navigation systems depend on the level of abstraction of the environment representation. The three main techniques for representing the environment will be described: geometric, topological, and semantic. The geometric representation of the environment is closer to the sensor and actuator world and it is the best one to perform local navigation. Topological representation of the environment uses graphs to model the environment and it is used in large navigation tasks. The semantic representation is the most abstract representation model and adds concepts such as utilities or meanings of the environment elements in the map representation. In addition, regardless of the representation used for navigation, perception plays a significant role in terms of understanding and moving through the environment

The 3D nature of a real un-dismantled electrical contact interface

AbstractA 3D contact analysis and modeling suite of tools are developed and introduced in this work. The “3D Contact Map” of an electrical contact interface is presented demonstrating the 3D nature of the contact. It gives information on where the electrical contact spots in a 3D surface profile are located. An X-ray Computer Tomography (CT) technique is used to collect the 3D data to a resolution of around 5μm of a real un-dismantled contact interface for analysis. Previous work by Lalechos and Swingler presented “2D Contact Map” on a 2D contact profile from collected 3D data to a resolution of around 8μm. The main advantages of both 3D and 2D mapping techniques focus on the fact that they are non-destructive and there is no need to dismantle the component of interest. This current work focuses on the 3D mapping technique showing its advantages over the 2D mapping technique. For test purposes, a 16A rated AC single pole switch is scanned after two different current loading tests (0A and 16A). A comparison for the total mechanical area of contact, the number of contact spots and the total contact resistance is conducted using both the 2D and 3D mapping techniques to a resolution of around 5μm

Object Detection Techniques Applied on Mobile Robot Semantic Navigation

The future of robotics predicts that robots will integrate themselves more every day with human beings and their environments. To achieve this integration, robots need to acquire information about the environment and its objects. There is a big need for algorithms to provide robots with these sort of skills, from the location where objects are needed to accomplish a task up to where these objects are considered as information about the environment. This paper presents a way to provide mobile robots with the ability-skill to detect objets for semantic navigation. This paper aims to use current trends in robotics and at the same time, that can be exported to other platforms. Two methods to detect objects are proposed, contour detection and a descriptor based technique, and both of them are combined to overcome their respective limitations. Finally, the code is tested on a real robot, to prove its accuracy and efficiency.The research leading to these results has received funding from the ARCADIA project DPI2010-21047-C02-01, funded by CICYT project grant on behalf of Spanish Ministry of Economy and Competitiveness and from the RoboCity2030-II project (S2009/DPI-1559), funded by Programas de Actividades I+D en la Comunidad de Madrid and cofunded by Structural Funds of the EU

Object detection applied to indoor environments for mobile robot navigation

To move around the environment, human beings depend on sight more than their other senses, because it provides information about the size, shape, color and position of an object. The increasing interest in building autonomous mobile systems makes the detection and recognition of objects in indoor environments a very important and challenging task. In this work, a vision system to detect objects considering usual human environments, able to work on a real mobile robot, is developed. In the proposed system, the classification method used is Support Vector Machine (SVM) and as input to this system, RGB and depth images are used. Different segmentation techniques have been applied to each kind of object. Similarly, two alternatives to extract features of the objects are explored, based on geometric shape descriptors and bag of words. The experimental results have demonstrated the usefulness of the system for the detection and location of the objects in indoor environments. Furthermore, through the comparison of two proposed methods for extracting features, it has been determined which alternative offers better performance. The final results have been obtained taking into account the proposed problem and that the environment has not been changed, that is to say, the environment has not been altered to perform the tests.The research leading to these results has received funding from the RoboCity2030-III-CM project (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, fase III; S2013/MIT-2748), funded by Programas de Actividades I+D en la Comunidad de Madrid and co-funded by Structural Funds of the EU and NAVEGASE-AUTOCOGNAV project (DPI2014-53525-C3-3-R), funded by Ministerio de Economía y competitividad of Spain

Semantic information for robot navigation: a survey

There is a growing trend in robotics for implementing behavioural mechanisms based on human psychology, such as the processes associated with thinking. Semantic knowledge has opened new paths in robot navigation, allowing a higher level of abstraction in the representation of information. In contrast with the early years, when navigation relied on geometric navigators that interpreted the environment as a series of accessible areas or later developments that led to the use of graph theory, semantic information has moved robot navigation one step further. This work presents a survey on the concepts, methodologies and techniques that allow including semantic information in robot navigation systems. The techniques involved have to deal with a range of tasks from modelling the environment and building a semantic map, to including methods to learn new concepts and the representation of the knowledge acquired, in many cases through interaction with users. As understanding the environment is essential to achieve high-level navigation, this paper reviews techniques for acquisition of semantic information, paying attention to the two main groups: human-assisted and autonomous techniques. Some state-of-the-art semantic knowledge representations are also studied, including ontologies, cognitive maps and semantic maps. All of this leads to a recent concept, semantic navigation, which integrates the previous topics to generate high-level navigation systems able to deal with real-world complex situationsThe research leading to these results has received funding from HEROITEA: Heterogeneous 480 Intelligent Multi-Robot Team for Assistance of Elderly People (RTI2018-095599-B-C21), funded by Spanish 481 Ministerio de Economía y Competitividad. The research leading to this work was also supported project "Robots sociales para estimulacón física, cognitiva y afectiva de mayores"; funded by the Spanish State Research Agency under grant 2019/00428/001. It is also funded by WASP-AI Sweden; and by Spanish project Robotic-Based Well-Being Monitoring and Coaching for Elderly People during Daily Life Activities (RTI2018-095599-A-C22)