5,919 research outputs found
Time-Dependent Fluid-Structure Interaction
The problem of determining the manner in which an incoming acoustic wave is
scattered by an elastic body immersed in a fluid is one of central importance
in detecting and identifying submerged objects. The problem is generally
referred to as a fluid-structure interaction and is mathematically formulated
as a time-dependent transmission problem. In this paper, we consider a typical
fluid-structure interaction problem by using a coupling procedure which reduces
the problem to a nonlocal initial-boundary problem in the elastic body with a
system of integral equations on the interface between the domains occupied by
the elastic body and the fluid. We analyze this nonlocal problem by the Lubich
approach via the Laplace transform, an essential feature of which is that it
works directly on data in the time domain rather than in the transformed
domain. Our results may serve as a mathematical foundation for treating
time-dependent fluid-structure interaction problems by convolution quadrature
coupling of FEM and BEM
Educational expansion and income distribution. A Micro-Simulation for Ceará
Does more education really mean less poverty and less inequality? How much less? What are the transmission mechanisms? This paper presents the results of a micro-simulation exercise for the Brazilian State of Ceará, which suggests that broad-based policies aimed at increasing educational attainment would have substantial impacts on poverty reduction, but muted effects on inequality. These results are highly dependent on assumptions about the behaviour of returns to education, both for the distribution of earnings and for the distribution of household income per capita. A large share of the poverty reducing effect of more education operates through greater incentives for labour force participation among the poor, and through reductions in fertility. Both of these effects function largely through decisions made by poor women.education, poverty, inequality
Automated pick-up of suturing needles for robotic surgical assistance
Robot-assisted laparoscopic prostatectomy (RALP) is a treatment for prostate
cancer that involves complete or nerve sparing removal prostate tissue that
contains cancer. After removal the bladder neck is successively sutured
directly with the urethra. The procedure is called urethrovesical anastomosis
and is one of the most dexterity demanding tasks during RALP. Two suturing
instruments and a pair of needles are used in combination to perform a running
stitch during urethrovesical anastomosis. While robotic instruments provide
enhanced dexterity to perform the anastomosis, it is still highly challenging
and difficult to learn. In this paper, we presents a vision-guided needle
grasping method for automatically grasping the needle that has been inserted
into the patient prior to anastomosis. We aim to automatically grasp the
suturing needle in a position that avoids hand-offs and immediately enables the
start of suturing. The full grasping process can be broken down into: a needle
detection algorithm; an approach phase where the surgical tool moves closer to
the needle based on visual feedback; and a grasping phase through path planning
based on observed surgical practice. Our experimental results show examples of
successful autonomous grasping that has the potential to simplify and decrease
the operational time in RALP by assisting a small component of urethrovesical
anastomosis
Genomic analysis of eight native plasmids of the phytopathogen Pseudomonas syringae
Comunicación a conferenciaThe pPT23A family of plasmids (PFPs) appears to be indigenous to the plant pathogen Pseudomonas syringae and these plasmids are widely distributed and widely transferred among pathovars of P. syringae and related species. PFPs are sources of accessory genes for their hosts that can include genes important for virulence and epiphytic colonization of plant leaf surfaces. Further understanding of the evolution of the pPT23A plasmid family and the role of these plasmids in P. syringae biology and pathogenesis, requires the determination and analysis of additional complete, closed plasmid genome sequences. Therefore, our main objective was to obtain complete genome sequences from PFPs from three different P. syringae pathovars and perform a comparative genomic analysis. In this work plasmid DNA isolation, purification by CsCl-EtBr gradients, and sequencing using 454 platform, were used to obtain the complete sequence of P. syringae plasmids. Different bioinformatic tools were used to analyze the plasmid synteny, to identify virulence genes (i.e. type 3 effectors) and to unravel the evolutionary history of PFPs. Our sequence analysis revealed that PFPs from P. syringae encode suites of accessory genes that are selected at different levels (universal, interpathovar and intrapathovar). The conservation of type IVSS encoding conjugation functions also contributes to the distribution of these plasmids within P. syringae populations. Thus, this study contributes to unravel the genetic basis of the role of PFPs in different P. syringae lifestyles.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Is vaping a low-risk substitute for cigarettes or an emerging epidemic?
In deciding how to regulate vaping and its advertising, policymakers face a conundrum due to the competing priorities of attracting long-term smokers to less harmful products and of preventing children and young people from taking up vaping. George Gaskell and Francisco Lupianez-Villanueva look at research findings that seek to determine the broader impact of vaping in the future
Digital Complex Correlator for a C-band Polarimetry survey
The international Galactic Emission Mapping project aims to map and
characterize the polarization field of the Milky Way. In Portugal it will
cartograph the C-band sky polarized emission of the Northern Hemisphere and
provide templates for map calibration and foreground control of microwave space
probes like ESA Planck Surveyor mission. The receiver system is equipped with a
novel receiver with a full digital back-end using an Altera Field Programmable
Gate Array, having a very favorable cost/performance relation. This new digital
backend comprises a base-band complex cross-correlator outputting the four
Stokes parameters of the incoming polarized radiation. In this document we
describe the design and implementation of the complex correlator using COTS
components and a processing FPGA, detailing the method applied in the several
algorithm stages and suitable for large sky area surveys.Comment: 15 pages, 10 figures; submitted to Experimental Astronomy, Springe
Comparative genomic analysis of native pseudomonas syringae plasmids belonging to the ppt23 a family reveals their role in p. Syringae epiphytic and pathogenic lifestyles
Backgrounds
The pPT23A family of plasmids (PFPs) appears to be indigenous to the plant pathogen Pseudomonas syringae and these plasmids are widely distributed and widely transferred among pathovars of P. syringae and related species. PFPs are sources of accessory genes for their hosts that can include genes important for virulence and epiphytic colonization of plant leaf surfaces.
Objectives
Further understanding of the evolution of the pPT23A plasmid family and the role of these plasmids in P. syringae biology and pathogenesis, requires the determination and analysis of additional complete, closed plasmid genome sequences. Therefore, our main objective was to obtain complete genome sequences of PFPs from three different P. syringae pathovars and perform a comprehensive comparative genomic analysis.
Methods
In this work plasmid DNA isolation, purification by CsCl-EtBr gradients, and sequencing using 454 platform, were carried out to obtain the complete sequence of P. syringae plasmids. Different bioinformatic tools were used to analyze the plasmid synteny, to identify virulence genes (i.e. type 3 effectors) and to unravel the evolutionary history of PFPs.
Conclusions
Our sequence analysis revealed that PFPs from P. syringae encode suites of accessory genes that are selected at different levels (universal, interpathovar and intrapathovar). The conservation of type IVSS encoding conjugation functions also contributes to the distribution of these plasmids within P. syringae populations. Thus, this study contributes to unravel the genetic bases of the role of PFPs in different P. syringae lifestyles.
This work was supported by grants Proyecto de Excelencia, Junta de Andalucía (P07-AGR-02471; P12-AGR-1473) and by Michigan State University AgBioResearch.This work was supported by grants Proyecto de Excelencia, Junta de Andalucía (P07-AGR-02471; P12-AGR-1473) and by Michigan State University AgBioResearch; Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Smart Conversational Agents for Reminiscence
In this paper we describe the requirements and early system design for a
smart conversational agent that can assist older adults in the reminiscence
process. The practice of reminiscence has well documented benefits for the
mental, social and emotional well-being of older adults. However, the
technology support, valuable in many different ways, is still limited in terms
of need of co-located human presence, data collection capabilities, and ability
to support sustained engagement, thus missing key opportunities to improve care
practices, facilitate social interactions, and bring the reminiscence practice
closer to those with less opportunities to engage in co-located sessions with a
(trained) companion. We discuss conversational agents and cognitive services as
the platform for building the next generation of reminiscence applications, and
introduce the concept application of a smart reminiscence agent
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