40 research outputs found
Dynamic Path Planning and Replanning for Mobile Robots using RRT*
It is necessary for a mobile robot to be able to efficiently plan a path from
its starting, or current, location to a desired goal location. This is a
trivial task when the environment is static. However, the operational
environment of the robot is rarely static, and it often has many moving
obstacles. The robot may encounter one, or many, of these unknown and
unpredictable moving obstacles. The robot will need to decide how to proceed
when one of these obstacles is obstructing it's path. A method of dynamic
replanning using RRT* is presented. The robot will modify it's current plan
when an unknown random moving obstacle obstructs the path. Various experimental
results show the effectiveness of the proposed method
Dynamic Path Planning and Replanning for Mobile Robot Team Using RRT*
It is necessary for a mobile robot to be able to efficiently plan a path from itsstarting or current location to a desired goal location. This is a trivial task when theenvironment is static. However, the operational environment of the robot is rarelystatic, and it often has many moving obstacles. The robot may encounter one, ormany, of these unknown and unpredictable moving obstacles. The robot will need todecide how to proceed when one of these obstacles is obstructing it's path. A methodof dynamic replanning using RRT* is presented. The robot will modify its currentplan when an unknown random moving obstacle obstructs the path. In multi-robotscenarios it is important to efficiently develop path planning solutions. A methodof node sharing is presented to quickly develop path plans for a multi-robot team.Various experimental results show the effectiveness of the proposed methods
Aristotle for the modern Ethicist
Elizabeth Anscombe and Mary Midgley discussed Aristotle’s ethics as an alternative to modern moral philosophy. This idea is best known from Anscombe’s 1958 paper ‘Modern Moral Philosophy’. The mainstream response has been to design a normative theory of ‘virtue ethics’ to rival deontology and consequentialism. This essay argues that that response is inadequate; it misses Anscombe’s point and obscures various aspects of Aristotle’s ethics, in particular his emphasis on friendship and human interconnectedness. This element of Aristotelianism was favoured by Midgley. By returning to Midgley, with the support of Aristotle, it is possible to find an alternative modern Aristotelianism in ethics
The genetics of blood pressure regulation and its target organs from association studies in 342,415 individuals
To dissect the genetic architecture of blood pressure and assess effects on target-organ damage, we analyzed 128,272 SNPs from targeted and genome-wide arrays in 201,529 individuals of European ancestry and genotypes from an additional 140,886 individuals were used for validation. We identified 66 blood pressure loci, of which 17 were novel and 15 harbored multiple distinct association signals. The 66 index SNPs were enriched for cis-regulatory elements, particularly in vascular endothelial cells, consistent with a primary role in blood pressure control through modulation of vascular tone across multiple tissues. The 66 index SNPs combined in a risk score showed comparable effects in 64,421 individuals of non-European descent. The 66-SNP blood pressure risk score was significantly associated with target-organ damage in multiple tissues, with minor effects in the kidney. Our findings expand current knowledge of blood pressure pathways and highlight tissues beyond the classic renal system in blood pressure regulation
Abdominal aortic aneurysm is associated with a variant in low-density lipoprotein receptor-related protein 1
Abdominal aortic aneurysm (AAA) is a common cause of morbidity and mortality and has a significant heritability. We carried out a genome-wide association discovery study of 1866 patients with AAA and 5435 controls and replication of promising signals (lead SNP with a p value < 1 × 10-5) in 2871 additional cases and 32,687 controls and performed further follow-up in 1491 AAA and 11,060 controls. In the discovery study, nine loci demonstrated association with AAA (p < 1 × 10-5). In the replication sample, the lead SNP at one of these loci, rs1466535, located within intron 1 of low-density-lipoprotein receptor-related protein 1 (LRP1) demonstrated significant association (p = 0.0042). We confirmed the association of rs1466535 and AAA in our follow-up study (p = 0.035). In a combined analysis (6228 AAA and 49182 controls), rs1466535 had a consistent effect size and direction in all sample sets (combined p = 4.52 × 10-10, odds ratio 1.15 [1.10-1.21]). No associations were seen for either rs1466535 or the 12q13.3 locus in independent association studies of coronary artery disease, blood pressure, diabetes, or hyperlipidaemia, suggesting that this locus is specific to AAA. Gene-expression studies demonstrated a trend toward increased LRP1 expression for the rs1466535 CC genotype in arterial tissues; there was a significant (p = 0.029) 1.19-fold (1.04-1.36) increase in LRP1 expression in CC homozygotes compared to TT homozygotes in aortic adventitia. Functional studies demonstrated that rs1466535 might alter a SREBP-1 binding site and influence enhancer activity at the locus. In conclusion, this study has identified a biologically plausible genetic variant associated specifically with AAA, and we suggest that this variant has a possible functional role in LRP1 expression
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.
OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis
Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.
Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways
Vancouver Especially : The Value of Deconstruction
The waste processes in most urban contexts are concealed from their citizens. Complex networks and systems made simple by way of drop-off and pick-up make for a disconnected and ignorant society in regards to how their own waste is actually dealt with. What’s out of sight is out of mind. This especially holds true with buildings, the biggest things we consume. One week a building’s there, the next, it’s gone. Where did it go? How were its materials digested into our waste systems? Was every part of that building ready to be treated as waste?
The prevailing methods of demolition waste management for single-family homes are inefficient, ineffective, and not aligned with the cultural consciousness of Vancouver or its goal for zero waste. There is still an immense amount of waste piling up in the landfill, and even a lot of the waste that is being diverted, is simply burned or brought elsewhere. The urgency of improving demolition waste management is a multi-fold issue regarding loss of valuable materials we will never see again, historical and cultural significance, meeting future waste goals, and general issues around sustainability and climate change at large.
The completion of one single-family home is the culmination of a symphony of industry perfected over centuries. The harvesting of materials, processing, manufacturing, distribution, and ultimately construction, has adapted over time to be successful through the natural selection process of capitalism - survival of the fittest. But what of when we want to rid ourselves of a product of these outputs? What architectural solution and industrial process reflects the inversion of construction? How can we turn a negative into a positive?
These are crucial questions to answer at a critical moment in the history of architectural waste management. Society is finally facing the end result of its architectural decisions made in the 20th century. How we choose to deal with the waste these buildings produce will pave the way for all constructions to follow; up until now, and into the future.Applied Science, Faculty ofArchitecture and Landscape Architecture (SALA), School ofUnreviewedGraduat
Extended rapidly exploring random tree-based dynamic path planning and replanning for mobile robots
It is necessary for a mobile robot or even a multi-robot team to be able to efficiently plan a path from its starting or current location to a desired goal location. This is a trivial task when the environment is static. However, the operational environment of the robot is rarely static, and it often has many moving obstacles. The robot may encounter one, or many, of these unknown and unpredictable moving obstacles. The robot will need to decide how to proceed when one of these obstacles is obstructing its path. In this article, a new method of dynamic replanning is proposed to allow the robot to efficiently plan a path in such complex environments. Our proposed replanning method is based on an extended rapidly exploring random tree. The robot will modify its current plan when unknown random moving obstacles obstruct the path. We extend the proposed replanning method to multi-robot scenarios in which the ability to share path planning and search tree information is valuable. An efficient method of node sharing is proposed to allow the multi-robot team to quickly develop path plans. Various experimental results in both single and multi-robot scenarios show the effectiveness of the proposed methods