4,769 research outputs found
Step by step illustrative video of laparoscopic artificial urinary sphincter implantation in a woman with recurrent stress urinary incontinence
info:eu-repo/semantics/publishedVersio
Bond Behavior of CFRP-to-Steel Bonded Joints at Mild Temperatures: Experimental Study
The performance of steel structures strengthened with externally bonded fiber-reinforced polymer (FRP) rely heavily on the interfacial shear stress transfer mechanism of the FRP-to-steel bonded interface. Much is known about the behavior of FRP-to-steel bonded joints under mechanical loading, but little is known about the performance of this type of bonded joints at elevated temperatures. Almost all adhesives typically used in FRP-to-steel applications experience a change in their mechanical behavior at temperatures <70°C. Therefore, gaining a sound understanding of the behavior of FRP-to-steel bonded joints at elevated temperatures is necessary. This paper presents a series of tests where carbon FRP (CFRP)-to-steel bonded joints are subjected to elevated temperatures. The outcomes of this paper showed that, at elevated temperatures, the dominant failure mode of the CFRP-to-steel bonded joints is the cohesion failure within the adhesive. The bond strength was found to increase with the temperature until the heat deflection temperature (HDT). The bondâslip behavior of the interface was found to undergo significant changes with increasing temperature. Specifically, the initial elastic stiffness and the peak shear stress were found to decrease as the temperature increases. The fracture energy was found to increase at temperatures below the HDT but then decrease drastically when the temperatures exceed the HDT
A double-edged sword: Residents' views on the health consequences of gentrification in Porto, Portugal
Gentrification is currently shaping the urban environment in important ways. It also contributes to shaping the health of the inhabitants of gentrifying cities, although it is still unclear how. Gentrification processes are often linked to different drivers and have specific local translations, further complicating the study of the relationship between gentrification and health. We investigated this relationship in Porto, Portugal, a southern European city undergoing rampant transnational gentrification. In order to study how gentrification impacts health from the point of view of that city's residents, we conducted a study using photovoice with a sample of participants recruited from a population-based cohort, which was divided into three different groups: one from gentrifying areas of Porto, another from deprived non-gentrifying areas, and the other from affluent areas. The thematic analysis of data generated six themes, each referring to a change, or a set of connected changes, related to gentrification: increasing floating population, lack of housing access and displacement, construction and rehabilitation, changing local commerce, loss of place, and broader socioeconomic change. According to the accounts from participants, these changes affect health in different ways, both beneficial and harmful. Participants also reflected on how to act on this issue. This research adds to the knowledge about the relationship between gentrification and health by providing detailed and nuanced views about this relationship considering its city-wide impacts.This work was supported by FEDER through the Operational Programme Competitiveness and Internationalisation and national funding from the Foundation for Science and Technology â FCT (Portuguese Ministry of Science, Technology and Higher Education) under the Unidade de Investigação em Epidemiologia - Instituto de SaĂșde PĂșblica da Universidade do Porto (EPIUnit) (UIDB/04750/2020) and LaboratĂłrio para an Investigação Integrativa e Translacional em SaĂșde Populacional (ITR) (LA/P/0064/2020); and the project âHUG: The health impacts of inner-city gentrification, displacement and housing insecurity: a quasi-experimental multi-cohort studyâ (PTDC/GES-OUT/1662/2020); Ana Isabel Ribeiro was supported by National Funds through FCT, under the âStimulus of Scientific Employment â Individual Supportâ programme within the contract CEECIND/02386/2018. The funding sources had no role in the research conducted neither in the preparation of this article
Voltage controlled terahertz transmission through GaN quantum wells
We report measurements of radiation transmission in the 0.220--0.325 THz
frequency domain through GaN quantum wells grown on sapphire substrates at room
and low temperatures. A significant enhancement of the transmitted beam
intensity with the applied voltage on the devices under test is found. For a
deeper understanding of the physical phenomena involved, these results are
compared with a phenomenological theory of light transmission under electric
bias relating the transmission enhancement to changes in the differential
mobility of the two-dimensional electron gas
Multifrequency Strategies for the Identification of Gamma-Ray Sources
More than half the sources in the Third EGRET (3EG) catalog have no firmly
established counterparts at other wavelengths and are unidentified. Some of
these unidentified sources have remained a mystery since the first surveys of
the gamma-ray sky with the COS-B satellite. The unidentified sources generally
have large error circles, and finding counterparts has often been a challenging
job. A multiwavelength approach, using X-ray, optical, and radio data, is often
needed to understand the nature of these sources. This chapter reviews the
technique of identification of EGRET sources using multiwavelength studies of
the gamma-ray fields.Comment: 35 pages, 22 figures. Chapter prepared for the book "Cosmic Gamma-ray
Sources", edited by K.S. Cheng and G.E. Romero, to be published by Kluwer
Academic Press, 2004. For complete article and higher resolution figures, go
to: http://www.astro.columbia.edu/~muk/mukherjee_multiwave.pd
A dusty pinwheel nebula around the massive star WR 104
Wolf-Rayet (WR) stars are luminous massive blue stars thought to be immediate
precursors to the supernova terminating their brief lives. The existence of
dust shells around such stars has been enigmatic since their discovery some 30
years ago; the intense radiation field from the star should be inimical to dust
survival. Although dust-creation models, including those involving interacting
stellar winds from a companion star, have been put forward, high-resolution
observations are required to understand this phenomena. Here we present
resolved images of the dust outflow around Wolf-Rayet WR 104, obtained with
novel imaging techniques, revealing detail on scales corresponding to about 40
AU at the star. Our maps show that the dust forms a spatially confined stream
following precisely a linear (or Archimedian) spiral trajectory. Images taken
at two separate epochs show a clear rotation with a period of 220 +/- 30 days.
Taken together, these findings prove that a binary star is responsible for the
creation of the circumstellar dust, while the spiral plume makes WR 104 the
prototype of a new class of circumstellar nebulae unique to interacting wind
systems.Comment: 7 pages, 2 figures, Appearing in Nature (1999 April 08
Learning Unions of k-Testable Languages
A classical problem in grammatical inference is to identify a language from a
set of examples. In this paper, we address the problem of identifying a union
of languages from examples that belong to several different unknown languages.
Indeed, decomposing a language into smaller pieces that are easier to represent
should make learning easier than aiming for a too generalized language. In
particular, we consider k-testable languages in the strict sense (k-TSS). These
are defined by a set of allowed prefixes, infixes (sub-strings) and suffixes
that words in the language may contain. We establish a Galois connection
between the lattice of all languages over alphabet {\Sigma}, and the lattice of
k-TSS languages over {\Sigma}. We also define a simple metric on k-TSS
languages. The Galois connection and the metric allow us to derive an efficient
algorithm to learn the union of k-TSS languages. We evaluate our algorithm on
an industrial dataset and thus demonstrate the relevance of our approach
Gamma Ray Pulsars: Multiwavelength Observations
High-energy gamma rays are a valuable tool for studying particle acceleration
and radiation in the magnetospheres of energetic pulsars. The seven or more
pulsars seen by instruments on the Compton Gamma Ray Observatory (CGRO) show
that: the light curves usually have double-peak structures (suggesting a broad
cone of emission); gamma rays are frequently the dominant component of the
radiated power; and all the spectra show evidence of a high-energy turnover.
For all the known gamma-ray pulsars, multiwavelength observations and
theoretical models based on such observations offer the prospect of gaining a
broad understanding of these rotating neutron stars. The Gamma-ray Large Area
Space Telescope (GLAST), now in planning for a launch in 2007, will provide a
major advance in sensitivity, energy range, and sky coverage.Comment: To appear in Cosmic Gamma Ray Sources, Kluwer ASSL Series, Edited by
K.S. Cheng and G.E. Romer
Immunoglobulin GM 3 23 5,13,14 phenotype is strongly associated with IgG1 antibody responses to Plasmodium vivax vaccine candidate antigens PvMSP1-19 and PvAMA-1
<p>Abstract</p> <p>Background</p> <p>Humoral immune responses play a key role in the development of immunity to malaria, but the host genetic factors that contribute to the naturally occurring immune responses to malarial antigens are not completely understood. The aim of the present investigation was to determine whether, in subjects exposed to malaria, GM and KM allotypes--genetic markers of immunoglobulin Îł and Îș-type light chains, respectively--contribute to the magnitude of natural antibody responses to target antigens that are leading vaccine candidates for protection against <it>Plasmodium vivax</it>.</p> <p>Methods</p> <p>Sera from 210 adults, who had been exposed to malaria transmission in the Brazilian Amazon endemic area, were allotyped for several GM and KM determinants by a standard hemagglutination-inhibition method. IgG subclass antibodies to <it>P. vivax </it>apical membrane antigen 1 (PvAMA-1) and merozoite surface protein 1 (PvMSP1-19) were determined by an enzyme-linked immunosorbent assay. Multiple linear regression models and the non-parametric Mann-Whitney test were used for data analyses.</p> <p>Results</p> <p>IgG1 antibody levels to both PvMSP1-19 and PvAMA-1 antigens were significantly higher (<it>P </it>= 0.004, <it>P </it>= 0.002, respectively) in subjects with the GM 3 23 5,13,14 phenotype than in those who lacked this phenotype.</p> <p>Conclusions</p> <p>Results presented here show that immunoglobulin GM allotypes contribute to the natural antibody responses to <it>P. vivax </it>malaria antigens. These findings have important implications for the effectiveness of vaccines containing PvAMA-1 or PvMSP1-19 antigens. They also shed light on the possible role of malaria as one of the evolutionary selective forces that may have contributed to the maintenance of the extensive polymorphism at the GM loci.</p
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