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Understanding the shear stress recovery mechanism during the stick-slip motion is a fundamental requirement for predicting the sliding behavior of rock joints. In this study, slide-hold-slide (SHS) type direct shear experiments under constant normal stress are performed on granite joints with significant roughness components to investigate the effects of compaction and dilation on the shear stress recovery. The shear stress recovery of rock joints is contributed by the growth of the contact area induced by the compaction during the hold period and the enhancement of dilation work during the re-shear process. The contact area reaches the maximum value under relatively low normal stress after the long hold period. Then, the dilation gradually contributes to the shear stress recovery because the welded asperities or grains are assembled, and the slide needs to ride over these bonded areas. The surface roughness plays a significant role in the shear stress recovery since the initial aperture and asperity morphology affect the compaction and dilation. The greater magnitude of shear stress recovery observed on rougher surfaces can be attributed to the effective normal closure during the hold period and significant dilation after the long hold periods.

A time series is a sequence of sequentially ordered real values in time. Time series classification (TSC) is the task of assigning a time series to one of a set of predefined classes, usually based on a model learned from examples. Dictionary-based methods for TSC rely on counting the frequency of certain patterns in time series and are important components of the currently most accurate TSC ensembles. One of the early dictionary-based methods was WEASEL, which at its time achieved SotA results while also being very fast. However, it is outperformed both in terms of speed and accuracy by other methods. Furthermore, its design leads to an unpredictably large memory footprint, making it inapplicable for many applications. In this paper, we present WEASEL 2.0, a complete overhaul of WEASEL based on two recent advancements in TSC: Dilation and ensembling of randomized hyper-parameter settings. These two techniques allow WEASEL 2.0 to work with a fixed-size memory footprint while at the same time improving accuracy. Compared to 15 other SotA methods on the UCR benchmark set, WEASEL 2.0 is significantly more accurate than other dictionary methods and not significantly worse than the currently best methods. Actually, it achieves the highest median accuracy over all data sets, and it performs best in 5 out of 12 problem classes. We thus believe that WEASEL 2.0 is a viable alternative for current TSC and also a potentially interesting input for future ensembles., Peer Reviewed

Atom interferometers with long baselines are envisioned to complement the ongoing search for dark matter. They rely on atomic manipulation based on internal (clock) transitions or state-preserving atomic diffraction. Principally, dark matter can act on the internal as well as the external degrees of freedom to both of which atom interferometers are susceptible. We, therefore, study in this contribution the effects of dark matter on the internal atomic structure and the atom's motion. In particular, we show that the atomic transition frequency depends on the mean coupling and the differential coupling of the involved states to dark matter, scaling with the unperturbed atomic transition frequency and the Compton frequency, respectively. The differential coupling is only of relevance when internal states change, which makes detectors, e.g., based on single-photon transitions sensitive to both coupling parameters. For sensors generated by state-preserving diffraction mechanisms like Bragg diffraction, the mean coupling modifies only the motion of the atom as the dominant contribution. Finally, we compare both effects observed in terrestrial dark-matter detectors.

The CNSC, the Canadian regulator for the nuclear industry, participated in DECOVALEX-2023 Task G that focuses on the thermo (T) - hydro (H)- mechanical (M) behaviour of rock joints. Joints are omnipresent in rock masses and are planes of weakness in the host rock. When deep geological repositories (DGRs) for radioactive waste are being considered in areas where rock joints are present, the joints could be preferential pathways for radionuclide migration. Therefore, their THM behaviour must be better understood to assess the safety of the DGR. Under different possible internal and external perturbations, a joint can move by shear and dilation. If the joint crosses the emplacement area of a waste container, the heat generated from the waste can itself induce shearing of the joint. Excessive shear movement can in turn lead to failure of the container, resulting in earlier release of radionuclides. Furthermore, dilation that might accompany shear, results in an increase in the joint aperture creating a faster flow path for radionuclide transport. Mathematical models are important tools that need to be developed and employed, in order to assess joint shear and dilation under different loading conditions, such as the heat generated from the emplaced waste. The authors have developed such a mathematical model based on a macroscopic formulation within the framework of elasto-plasticity. It is verified against analytical solutions and validated against shear under constant normal load tests and thermal shearing tests of joints in granite.

[Resumen]: En este artículo se muestra el uso de holografía interferométrica digital para el estudio de procesos de microdilatación. Mediante el uso de un esquema óptico y una cámara CCD se realizaron interferogramas sobre distintos objetos de estudio, a los cuales se les indujo un incremento de temperatura localizado mediante irradiación laser de 5.5 W y 405 nm. Este procedimiento se realizó sobre dos muestras con comportamiento termo-mecánico diferente, a fin de determinar la distribución de franjas asociadas a la micro-dilatación. El objetivo propuesto fue estudiar la respuesta en dispositivos de iluminación basado en tecnología LED, con el fin de determinar el comportamiento térmico-mecánico relacionado con los procesos de encendido y apagado. Los resultados obtenidos muestran que estos dispositivos se encuentran sometidos a un estrés mecánico derivado de dilataciones diferenciales entre los componentes que integran el montaje, [Abstract]: This paper presents the use of digital holography interferometry applied to the study of microdilation process. The optical setup with the use of CCD cameras allowed to obtain interferograms on different study objects, whereas a localized thermal load was induced by a 5.5 W 405 nm laser. This study was done over two samples with different thermal conductivity in order to calibrate this process. The main objective of this work was to understand the thermomechanical response on LED based illumination devices due to the transition in the on-off process. The results show that these kind of lamps function under mechanical stress because of the different dilation process of each component of the device.

The shearing characteristics of rock joints govern the mechanical performance of discontinuous rock masses. The present study investigated the normal compression and shear behavior of rock joints through cyclic compression tests and direct shear tests. The irreversible relationship between the normal stress and the normal closure was confirmed by cyclic compression tests on rock joints. An elastoplastic model was proposed incorporating the aperture variation. A modified version of the critical state framework was developed for modeling the shearing and dilation behavior. Specifically, the initial state of the rock joints was determined according to the stress history. The proposed model for the mechanical behavior of rock joints was validated by predicting the experimental results. A parameter analysis was also performed to highlight the difference in the shear behavior of the rock joints due to the difference in the initial apertures.

In the study, biaxial shearing tests were carried out through the numerical simulations based on the discrete element method to examine the correlation of macro deformation and micro kinematics characterization in contact scale. The contact motions were decomposed into three independent types, i.e., contact deformation, contact rolling and rigid-body motion. The simulated dense sample can qualitatively reproduce the experimental outcomes for the stress–strain and volumetric relationship. From the micro to macro scale, it is found that the particle nonaffine displacement and particle rotation have strong spatial correlations with development of the shear band and the different contact motions have different influences on the sample deformation. That is, the contact deformation dominates the whole sample deformation, while the contact rolling and the rigid-body rotation have relatively small contributions to the volume change during the whole shearing process. The external loading is mostly supported by the strong contact forces in the sample, but the dilation deformation is more obvious in the weak contact force network. In strong contact force network, the contact deformation mainly induces contraction for the sample; the rigid-body rotation and contact rolling also contribute to contraction slightly; hence, the overall deformation in the strong contact force network is contraction. In the weak contact force network, the contact deformation creates dilation; the contact rolling has a small contribution to contraction, and the rigid-body rotation has no contribution to the volume change; thus, the overall dilation for the sample in the weak contact force network is observed. © 2021 Elsevier Ltd

Ultraljudsundersökningar av arteria carotis communis (CCA) utförs med ultraljud vid bedömning av kärlförändringar och flödeshastigheter (FH) samt utredning av sjukdomar i CCA. Lumendiameter (LD) i CCA är en markör för riskfaktorer som leder till stroke, hjärtinfarkt och ateroskleros. Syftet med den aktuella studien är att studera om det sker någon vasoaktiv förändring i CCA vid konsumtion av koffein hos unga vuxna. Det var 33 försökspersoner som delades upp i grupper beroende på deras koffeinkonsumtionsvanor och undersöktes med ultraljud. Försökspersonerna hade innan undersökning inte konsumerat koffein på 12 timmar. Undersökningen utfördes innan konsumtion av koffeindryck och 45 minuter efter koffeinkonsumtion. En signifikant skillnad efter konsumtion av koffein påvisades i lågkonsument gruppen (grupp 1) (p.0,06) och högkonsument gruppen (grupp 3) (p=0,05). En positiv korrelation mellan LD innan och efter konsumtion (r=0,955; p <0,01) samt FH innan och efter konsumtion (r=0,393; p <0,01) av koffein kunde påvisas. Nyckelord: Carotisduplex, Kaffe, Vasoaktiv, CCA.

An anisotropic damage model is employed in order to simulate the fracture pattern of Bohus granite under quasi-static (Q-S) spherical indentation loading. The chosen damage description is added to the previously employed Drucker–Prager (DP) plasticity model with variable dilation angle. The resulting constitutive model is implemented to simulate the behavior of Bohus granite under indentation up to the load capacity of the material. The initial fragmentation, corresponding to the first small load-drop in the force–penetration curve, is likely due to the high radial tensile stress state at or close to the contact boundary. Both predicted fracture pattern and force–penetration results from the numerical simulation are compared to experimental data and a good agreement is found. The variability in tensile strength of the material is included in the chosen damage model by taking advantage of Weibull statistics. In this work, it is suggested that indentation test results by themselves may be used to calibrate the statistical distribution of tensile strength at small size scales such as in indentation applications., QC 20220609

A Sylvester equation is an operator equation of the form $AX-XB=C$. A fact that has been proven multiple times before, see \cite{penzl2000eigenvalue,sabino2006solution}, is that if $C$ has low rank, then $A$ and $B$ satisfying certain conditions imply $X$ has a low rank approximation. Another set of conditions was given by Beckermann and Townsend in 2019, \cite{beckermann2019bounds}, where they impose the conditions that $A$ and $B$ are both normal, and have disjoint and well-separated spectra. In this thesis, we explore cases where the normality condition can be relaxed. Our main tool is unitary operator dilations, whereby one can realize a given operator as the corner of a unitary operator acting on a bigger space. The basic problem becomes the lifting of the original Sylvester equation to a new one involving the unitary dilation. This is reminiscent of the so-called intertwining dilation theorem, but it requires a completely new analysis as we require additional conditions if we wish to be able to guarantee the solution has a low rank approximation. Our main result states that if we trade in normality of $A$ for a norm condition on $A$ and $B$, then we can unitarily dilate $A$. This in turn allows us to conclude that $X$ has a low rank approximation provided our condition is satisfied, $B$ is normal, and $C$ has low rank. Due to the similarity in the conditions for the theorem by Beckermann and Townsend and the conditions required to solve a Sylvester equation quickly using algorithms such as the alternating direction implicit (ADI) method, our dilation method also allows us to show the ADI method does not require too many iterations without requiring $A$ to be normal.

Fluid/fluid interfaces are ubiquitous in science and technology, and hence, the understanding of their properties presents a paramount importance for developing a broad range of soft interface dominated materials, but also for the elucidation of different problems with biological and medical relevance. However, the highly dynamic character of fluid/fluid interfaces makes shedding light on fundamental features guiding the performance of the interfaces very complicated. Therefore, the study of fluid/fluid interfaces cannot be limited to an equilibrium perspective, as there exists an undeniable necessity to face the study of the deformation and flow of these systems under the application of mechanical stresses, i.e., their interfacial rheology. This is a multidisciplinary challenge that has been evolving fast in recent years, and there is currently available a broad range of experimental and theoretical methodologies providing accurate information of the response of fluid/fluid interfaces under the application of mechanical stresses, mainly dilational and shear. This review focused on providing an updated perspective on the study of the response of fluid/fluid interfaces to dilational stresses; to open up new avenues that enable the exploitation of interfacial dilational rheology and to shed light on different problems in the interest of science and technology.

Fluid/fluid interfaces are ubiquitous in science and technology, and hence, the understanding of their properties presents a paramount importance for developing a broad range of soft interface dominated materials, but also for the elucidation of different problems with biological and medical relevance. However, the highly dynamic character of fluid/fluid interfaces makes shedding light on fundamental features guiding the performance of the interfaces very complicated. Therefore, the study of fluid/fluid interfaces cannot be limited to an equilibrium perspective, as there exists an undeniable necessity to face the study of the deformation and flow of these systems under the application of mechanical stresses, i.e., their interfacial rheology. This is a multidisciplinary challenge that has been evolving fast in recent years, and there is currently available a broad range of experimental and theoretical methodologies providing accurate information of the response of fluid/fluid interfaces under the application of mechanical stresses, mainly dilational and shear. This review focused on providing an updated perspective on the study of the response of fluid/fluid interfaces to dilational stresses; to open up new avenues that enable the exploitation of interfacial dilational rheology and to shed light on different problems in the interest of science and technology.

In a repository for radioactive waste hosted in a clay formation, hydrogen and other gases may be generated due to the corrosion of metallic materials under anoxic conditions, the radioactive decay of waste and the radiolysis of water. If the gas production rate exceeds the gas diffusion rate within the pores of the clay, a discrete gas phase will form and accumulate until its pressure becomes large enough to exceed the entry pressure of the surrounding material, at which point dilatant, advective flow of gas is expected to occur. The purpose of Task An under DECOVALEX-2019 is to better represent the processes governing the advective movement of gas in both low-permeability argillaceous repository host rocks and clay-based engineered barriers within numerical codes. In this paper special attention is given to the mechanisms controlling gas entry, flow and pathway sealing and their impact on the performance of the engineered clay barrier. Previous work suggests gas flow is accompanied by the creation of dilatant pathways whose properties change temporally and spatially within the medium. Thus, four new types of approaches have been developed: (i) standard two-phase flow models (continuous techniques) incorporating a range of different mechanical deformation behaviours, (ii) enhanced two-phase flow models in which fractures are embedded within a plastic material (continuous techniques) or incorporated into the model using a rigid-body-spring network (discrete approaches), (iii) a single-phase model incorporating a creep damage function in which only gas flow is considered, and (iv) a conceptual approach used to examine the chaotic nature of gas flow. The outputs from these different approaches are compared. This is an essential step as the choice of modelling approach strongly impacts the representation and prediction of gas flow in a future repository. In addition, experience gained through this task is of direct relevance to other clay-based engineering issues where

Water level measurement is one of the hydraulic study necessities especially in lab researches. In most common methods, waterlevel is directly measured. It is also important to measure reservoirs water level in research related with water depth. There arevarietiesof ways for water level measurement compatible with different situations with some structural or financial disadvantages. For instance ultrasonic sensors are very accurate. However,it is often very costly to purchase these sensors. The purposeof this project is to represent a new method of water level measurement using image processing. For removing some limitations of devices invented previously according to requirements of different experiences, we commenced building an affordable device forwater measurement. The device operation is based on an image processing program written on MATLAB. High Definationwebcam takes pictures needed for image processing from a built in stand connected to a main reservoir.

In a repository for radioactive waste hosted in a clay formation, hydrogen and other gases may be generated due to the corrosion of metallic materials under anoxic conditions, the radioactive decay of waste and the radiolysis of water. If the gas production rate exceeds the gas diffusion rate within the pores of the clay, a discrete gas phase will form and accumulate until its pressure becomes large enough to exceed the entry pressure of the surrounding material, at which point dilatant, advective flow of gas is expected to occur. The purpose of Task An under DECOVALEX-2019 is to better represent the processes governing the advective movement of gas in both low-permeability argillaceous repository host rocks and clay-based engineered barriers within numerical codes. In this paper special attention is given to the mechanisms controlling gas entry, flow and pathway sealing and their impact on the performance of the engineered clay barrier. Previous work suggests gas flow is accompanied by the creation of dilatant pathways whose properties change temporally and spatially within the medium. Thus, four new types of approaches have been developed: (i) standard two-phase flow models (continuous techniques) incorporating a range of different mechanical deformation behaviours, (ii) enhanced two-phase flow models in which fractures are embedded within a plastic material (continuous techniques) or incorporated into the model using a rigid-body-spring network (discrete approaches), (iii) a singlephase model incorporating a creep damage function in which only gas flow is considered, and (iv) a conceptual approach used to examine the chaotic nature of gas flow. The outputs from these different approaches are compared. This is an essential step as the choice of modelling approach strongly impacts the representation and prediction of gas flow in a future repository. In addition, experience gained through this task is of direct relevance to other clay-based engineering issues where, DECOVALEX is an international research project comprising participants from industry, government and academia, focusing on development of understanding, models and codes in complex coupled problems in sub-surface geological and engineering applications; DECOVALEX-2019 is the current phase of the project. The authors appreciate and thank the DECOVALEX-2019 funding organisations Andra, BGR/UFZ, CNSC, US DOE, ENSI, JAEA, IRSN, KAERI, NWMO, RWM, SÚRAO, SSM and Taipower for their financial and technical support of the work described in this paper. The statements made in the paper are, however, solely those of the authors and do not necessarily reflect those of the funding organisations., Peer Reviewed, Postprint (published version)

In a repository for radioactive waste hosted in a clay formation, hydrogen and other gases may be generated due to the corrosion of metallic materials under anoxic conditions, the radioactive decay of waste and the radiolysis of water. If the gas production rate exceeds the gas diffusion rate within the pores of the clay, a discrete gas phase will form and accumulate until its pressure becomes large enough to exceed the entry pressure of the surrounding material, at which point dilatant, advective flow of gas is expected to occur.The purpose of Task An under DECOVALEX-2019 is to better represent the processes governing the advective movement of gas in both low-permeability argillaceous repository host rocks and clay-based engineered barriers within numerical codes. In this paper special attention is given to the mechanisms controlling gas entry, flow and pathway sealing and their impact on the performance of the engineered clay barrier. Previous work suggests gas flow is accompanied by the creation of dilatant pathways whose properties change temporally and spatially within the medium. Thus, four new types of approaches have been developed: (i) standard two-phase flow models (continuous techniques) incorporating a range of different mechanical deformation behaviours, (ii) enhanced two-phase flow models in which fractures are embedded within a plastic material (continuous techniques) or incorporated into the model using a rigid-body-spring network (discrete approaches), (iii) a single-phase model incorporating a creep damage function in which only gas flow is considered, and (iv) a conceptual approach used to examine the chaotic nature of gas flow. The outputs from these different approaches are compared. This is an essential step as the choice of modelling approach strongly impacts the representation and prediction of gas flow in a future repository. In addition, experience gained through this task is of direct relevance to other clay-based engineering issues where

Introduction: Post-sleeve gastrectomy (SG) stenoses occur in about 5% of cases. Hydrostatic dilation (HD) and pneumatic dilation (PD) have been proposed as treatments, but efficacy data remain scarce. Objective is to describe long-term efficacy and safety of HD and PD. Methods: This retrospective study in a referral endoscopy center included patients with symptomatic post-SG stenosis treated with endoscopic balloon dilation (EBD). Stenosis was defined as “organic” if luminal narrowing was evident, “functional” for a deformation, or “combined.” Endoscopic treatment consisted of ≥ 1 HD (15–20 mm) and/or ≥ 1 PD (30–35 mm). Initial success was defined as improvement of stenosis-related symptoms at 1 month and long-term success as persistence of improvement at last follow-up. Results: Forty-four patients (73% women; mean age 45.5 ± 11 years; mean follow-up 26 ± 23 months) underwent EBD between 2013 and 2019. HD and PD were used in 15 (34%) and 29 (66%) patients, respectively, (mean dilation number: 1.8 ± 1.1). Post-SG stenoses were considered organic in 10 (23%), functional in 21 (48%), and combined in 13 (29%) patients. Initial success was achieved in 42 (96%) patients, while 35 (80%) patients had no symptom recurrence at last follow-up. Perforation occurred in one patient. HD was more frequently used in organic stenoses (8/10), while PD in functional and combined stenoses (18/21 and 9/13, respectively; p < 0.001). Rates of success did not differ by type of stenosis. Conclusion: Endoscopic dilation is an effective treatment for post-SG stenoses, providing long-term symptom relief. PD should be preferred in cases of functional stenoses, and HD used for organic stenoses., SCOPUS: ar.j, info:eu-repo/semantics/published

© 2020 MDPI F.C. is funded by the Fundacao para a Ciencia e a Tecnologia (FCT, Portugal) doctoral grant No. PD/BD/128017/2016. F.S.N.L. acknowledges support fromthe FCT Scientific Employment Stimulus contract with reference CEECIND/04057/2017. D.R.-G. is funded by the Atracci ' on de Talento Investigador programme of the Comunidad de Madrid (Spain) No. 2018-T1/TIC-10431, and acknowledges further support from the Ministerio de Ciencia, Innovaci ' on y Universidades (Spain) project No. PID2019-108485GB-I00/AEI/10.13039/501100011033, the Spanish project No. FIS2017-84440-C2-1-P (MINECO/FEDER, EU), the project PROMETEO/2020/079 (Generalitat Valenciana), and the Edital 006/2018 PRONEX (FAPESQ-PB/CNPQ, Brazil) Grant No. 0015/2019. The authors also acknowledge funding from FCT Projects No. UID/FIS/04434/2020, No. CERN/FIS-PAR/0037/2019 and No. PTDC/FIS-OUT/29048/2017. This article is based upon work from COST Actions CA15117 and CA18108, supported by COST (European Cooperation in Science and Technology)., Gravity can be formulated as a gauge theory by combining symmetry principles and geometrical methods in a consistent mathematical framework. The gauge approach to gravity leads directly to non-Euclidean, post-Riemannian spacetime geometries, providing the adequate formalism for metric-affine theories of gravity with curvature, torsion and non-metricity. In this paper, we analyze the structure of gauge theories of gravity and consider the relation between fundamental geometrical objects and symmetry principles as well as different spacetime paradigms. Special attention is given to Poincare gauge theories of gravity, their field equations and Noether conserved currents, which are the sources of gravity. We then discuss several topics of the gauge approach to gravitational phenomena, namely, quadratic Poincare gauge models, the Einstein-Cartan-Sciama-Kibble theory, the teleparallel equivalent of general relativity, quadratic metric-affine Lagrangians, non-Lorentzian connections, and the breaking of Lorentz invariance in the presence of non-metricity. We also highlight the probing of post-Riemannian geometries with test matter. Finally, we briefly discuss some perspectives regarding the role of both geometrical methods and symmetry principles towards unified field theories and a new spacetime paradigm, motivated from the gauge approach to gravity., Ministerio de Ciencia e Innovación (MICINN), Ministerio de Economía y Competitividad (MINECO)/FEDER, Comunidad de Madrid, Generalitat Valenciana, Fundação para a Ciência e a Tecnologia (FCT), FAPESQ-PB/CNPQ, Depto. de Física Teórica, Fac. de Ciencias Físicas, TRUE, pub

Microvascular dysfunction may be associated with worse cognitive performance. Most previous studies did not adjust for important confounders, evaluated only individual measures of microvascular dysfunction, and showed inconsistent results. We evaluated the association between a comprehensive set of measures of microvascular dysfunction and cognitive performance in the population-based Maastricht Study. We used cross-sectional data including 3011 participants (age 59.5±8.2; 48.9% women; 26.5% type 2 diabetes mellitus [oversampled by design]). Measures of microvascular dysfunction included magnetic resonance imaging features of cerebral small vessel disease, plasma biomarkers of microvascular dysfunction, albuminuria, flicker light-induced retinal arteriolar and venular dilation response and heat-induced skin hyperemia. These measures were summarized into a microvascular dysfunction composite score. Cognitive domains assessed were memory, processing speed, and executive function. A cognitive function score was calculated as the sum of the scores on these 3 cognitive domains. The microvascular dysfunction score was associated with a worse cognitive function score (standardized β, −0.087 [95% CI, −0.127 to −0.047]), independent of age, education level, sex, type 2 diabetes mellitus, smoking, alcohol use, hypertension, total/HDL (high-density lipoprotein) cholesterol ratio, triglycerides, lipid-modifying medication, prior cardiovascular disease, depression and plasma biomarkers of low-grade inflammation. The fully adjusted β-coefficient of the association between the microvascular dysfunction score and the cognitive function score was equivalent to 2 (range, 1–3) years of aging for each SD higher microvascular dysfunction score. The microvascular dysfunction score was associated with worse memory and processing speed but not with worse executive function. The present study shows that microvascular dysfunction is associated with worse cognitive performance.

The notion of translation-invariant operators is described and explained with reference to binary images. Erosion and dilation, opening and closing are discussed at length. Grey-scale morphology is introduced and the use of the umbra is presented. T-operators and their representation are described.

The present investigation was carried out to find out the effects of high dose of L-lysine on the fish and also an attempt has been made to predict the impact on human health. L-lysine is an essential amino acid which is used in medical practices as a growth promoter of bones especially in infants. Important work on metabolism and functions of amino acids in human health and major diseases has been reported by many workers and evaluated the key role of various amino acids in response to infections. Lysine is not synthesized by body; therefore, it must be taken either by diet or supplementation. Lysine first of all isolated from casein in 1889 and introduced as Lysine hydrochloride in 1955. The recommended dose of lysine is 12mg/kg body weight. Side effects of Lysine in large doses i.e. 10-30gm/day may cause abdominal cramps and diarrhea but renal and hepatic toxicity is not reported in normal person. Amino acids are used to treat end stage renal failure and also in liver failure. Recently lysine is used to treat herpes and as a supplement for diabetic people. In present study the effect of acute high dose 2mg/100gm body weight of L-lysine in fish shows toxic effects on kidney and liver which is an alarming indication towards use of high dose of Lysine in man. In kidney it caused glomerular dilation of the capillaries, glomerular hemorrhages and cloudy swelling of renal tubules. In liver it leads swelling of hepatocytes, vacuolization, fatty degeneration and central vein dilation. These histopathological changes are supported by marked rise in level of blood urea, serum creatinine, blood sugar and serum cholesterol.

PRéCIS:: Small but significant decreases in optical coherence tomography angiography (OCTA)-measured circumpapillary capillary density (cpCD) were observed in healthy eyes dilated with 2.5% phenylephrine/0.5% tropicamide. Although likely clinically insignificant, ophthalmologists should consider these changes when interpreting OCTA results from dilated eyes.PurposeThe purpose of this study was to investigate the effect of pupil dilation using 2.5% phenylephrine and 0.5% tropicamide on quantitative assessment of retinal microvasculature using OCTA.MethodsOptoVue AngioVue high density (HD) and non-HD OCTA macula and optic nerve head (ONH) images were obtained at 15-minute intervals predilation and postdilation in 26 healthy participants (mean age: 40.0; 95% confidence interval=33.9, 46.1 y). Superficial macular vessel density (VD) was measured in the whole image VD and the parafoveal region VD. ONH capillary density was measured in the whole image capillary density and the cpCD region. Differences between predilation and postdilation densities were assessed using linear mixed effects models to account for within-patient correlation.ResultsInstillation of dilating drops resulted in a small but statistically significant reduction in non-HD ONH whole image capillary density of 0.6%, from a mean of 45.2% (95% confidence interval=41.9%, 48.4%) to 44.6% (41.4%, 47.8%) (P=0.046). A similar reduction in non-HD ONH cpCD of 0.8% also was observed, from a mean of 49.3% (45.3%, 53.3%) to 48.5% (44.5%, 52.4%) (P=0.025). No postdilation decreases in macular VD or HD ONH capillary density were observed.ConclusionsPupil dilation using topical 2.5% phenylephrine and 0.5% tropicamide results in a small but statistically significant reduction in non-HD ONH whole image and cpCD in healthy eyes. The observed reduction likely is not clinically significant because the observed reduction was within the previously reported range of measurement variability. Further studies should consider inve

This paper modifies a 3D geomechanical constitutive model that uses two independent yield surfaces composed of shear failure and a strain rate-dependent pore collapse yield surfaces in order to describe the dilation and compaction mechanism of deformation. The model is developed based on the combination of non-associated shear failure and the viscoplastic consistency model relying on empirical formulation originally developed by J.A. de Waal and coworkers in the late 1980s. The model has the capability of representing the compaction deformation due to the creep phase. The model is also capable of predicting the softening in shear failure, which offers the option to use the model for stability analyses. A fully implicit stress-update algorithm for the multi-mechanism consistency model is used to determine the viscoplastic strain components. Several simulations are considered using a single element model in uniaxial and triaxial conditions to illustrate the behavior of the proposed model. Comparing the results with laboratory data indicates that the proposed model can reproduce the rate-dependent behavior in chalk.

Background: Patients with cyanotic congenital heart disease (CCHD) may have a low burden of atherosclerosis. Endothelial dysfunction is an early stage of atherosclerosis and endothelial function is previously studied in smaller CCHD groups with different techniques and variable results. We aimed to examine endothelial function and carotid atherosclerosis in a larger group of CCHD patients.Methods: This multicentre study assessed endothelial function in adults with CCHD and controls by measuring the dilatory response of the brachial artery to post-ischemic hyperaemia (endothelium-dependent flow-mediated-vasodilatation (FMD)), and to nitroglycerin (endothelium-independent nitroglycerin-induced dilatation (NID)). Flow was measured at baseline and after ischaemia (reactive hyperaemia). Carotid-intima-media-thickness (CIMT), prevalence of carotid plaque and plaque thickness (cPT-max) were evaluated ultrasonographically. Lipoproteins, inflammatory and vascular markers, including sphingosine-1-phosphate (S1P) were measured.Results: Forty-five patients with CCHD (median age 50 years) and 45 matched controls (median age 52 years) were included. The patients presented with lower reactive hyperaemia (409 +/- 114% vs. 611 +/- 248%, p <0.0001), however preserved FMD response compared to controls (106.5 +/- 8.3% vs. 106. 4 +/- 6.1%, p = 0.95). In contrast, NID was lower in the patients (110.5 +/- 6.1% vs. 115.1 +/- 7.4%, p = 0.053). There was no difference in CIMT, carotid plaque or cPT-max. The patients presented with lower high-density-lipoprotein cholesterol, and higher level of inflammatory markers and S1P.Conclusion: Adults with CCHD had preserved FMD in the brachial artery, but impaired NID response and lower reactive hyperaemia than controls. The preserved FMD and the comparable prevalence of carotid atherosclerosis indicate that CCHD patients have the same risk of atherosclerosis as controls. (C) 2020 The Authors. Published by Elsevier B.V.

Background Roux-en-Y gastric bypass (RYGB) is the most common bariatric procedure worldwide. Anastomotic stricture is a known complication of RYGB. The aim was to explore the incidence and outcomes of strictures within the Scandinavian Obesity Surgery Registry (SOReg). Method SOReg included prospective data from 36,362 patients undergoing bariatric surgery in the years 2007–2013. Outcomes were recorded at 30-day and at 1-year follow-up according to the standard SOReg routine. The medical charts of patients suffering from stricture after RYGB were requested and assessed. Setting National bariatric surgery registry Results Anastomotic stricture within 1 year of surgery was confirmed in 101 patients representing an incidence of 0.3%. Risk factors for stricture were patient age above 60 years (odds ratio (OR), 6.2 95% confidence interval (CI) 2.7–14.3), circular stapled gastrojejunostomy (OR 2.7, 95% CI 1.4–5.5), postoperative anastomotic leak (OR 8.9 95%, CI 4.7–17.0), and marginal ulcer (OR 30.0, 95% CI 19.2–47.0). Seventy-five percent of the strictures were diagnosed within 70 days of surgery. Two dilatations or less was sufficient to successfully treat 50% of patients. Ten pecent of patients developed perforation during dilatation, and the risk of perforating at each dilatation was 3.8%. Perforation required surgery in six cases but there was no mortality. Strictures in SOReg may be underreported, which could explain the low incidence in the study. Conclusion Most strictures present within 2 months and are successfully treated with two dilatations or less. Dilating a strictured gastrojejunostomy entails a risk of perforation (3.8%).

Recent scientific investigations suggest that people automatically mimic each other’s pupil sizes during interaction. However, instead of being a social mimicry effect, it could also be the result of brightness perception. When observers look at individuals with dilated pupils, little of the brighter iris is visible, leading to the perception of a relatively low-illuminated eye region. In the current study we tested whether pupil mimicry remains present when pupils and irises are equalized for luminance values across pupil sizes. We tested several stimulus sets, including faces with static pupils that varied in size across images and dynamic pupils that changed in size over time in videos. Results showed that for traditional, not-luminance-equalized videos, participants’ pupil sizes adapted to the observed pupils, showing a pattern that is roughly in line with pupil mimicry. However, no such pupil response in line with mimicry was seen for static images (regardless of whether they were equalized for luminance) nor for luminance-equalized videos. These findings suggest that only salient, dynamic stimuli attract enough attention to the luminance in the eye region to evoke a pupillary response. However, although such responses suggest pupil mimicry, the underlying factor is the change in brightness within the eye as a function of pupil size rather than social mimicry.

Background: Rates of cesarean section increase worldwide, and the components of this increase are partially unknown. A strong role is prescribed to dystocia, and at the same time, the diagnosis of dystocia is highly subjective. Previous studies indicated that risk of cesarean is higher when women are admitted to the hospital early in the labor. Methods: We examined data on 1,202 nulliparous women with singleton, vertex pregnancies and spontaneous labor onset. We selected three groups based on cervical dilatation at admission: early (0.5-1.5 cm, N = 178), intermediate (2.5-3.5 cm, N = 320), and late (4.5-5.5 cm, N = 175). The Kaplan–Meier estimator was used to analyze the risk of delivery by cesarean section at a given dilatation, and thin-plate spline regression with a binary outcome (R library gam) to assess the form of the associations between the cesarean section in either the first or second stage versus vaginal delivery and dilatation at admission. Results: Women who were admitted to labor early had a higher risk of delivery by cesarean section (18 versus 4% in the late admission group), while the risk of instrumental delivery did not differ (24 versus 24%). Before 4 cm dilatation, the earlier a woman was admitted to labor, the higher was her risk of delivery by cesarean section. After 4 cm dilatation, however, the relationship disappeared. These patterns were true for both first and second stage cesarean deliveries. Oxytocin use was associated with a higher risk of cesarean section only in the middle group (2.5-3.5 cm dilatation at admission). Conclusion: Early admission to labor was associated with a significantly higher risk of delivery by cesarean section during the first and second stages. Differential effects of oxytocin augmentation depending on dilation at admission may suggest that admission at the early stage of labor is an indicator rather than a risk factor itself, but admission at the intermediate stage (2.5-3.5 cm) becomes a risk factor itself. Fu

The cell population is used to determine the effect of a drug to understand the disease mechanisms. Thus the analysis of the population behavior provides new insights in medicine development. This project focuses on developing a simple method for cell images which have low resolution and high complexity. The various techniques such as image thresholding, watershed segmentation, opening, dilation, contrast stretching are applied in segmentation and analysis of the image. The estimate of the cell boundary is done using the nucleus image which is assumed as the central part of the considered cells. The cancer cell images of Scott and White(SW) cel line of Beta Catenin(BC) and Krupel Like Factor(KLF) genes have been analyzed and the corresponding average intensity data of the population and a comparison of the Otsu and Huang thresholding methods has been produced. The softwares used in the project are MATLAB 2014 and ImageJ.

An efficient way of improving the seismic capacity of structurally deficient RC columns is retrofitting with some suitable materials. In recent years, the use of externally bonded fiber-reinforced polymer (FRP) sheets has been widely increased. An FRP jacket with a large rupture strain (LRS), for example, polyethylene terephthalate (PET) FRP, is generally more beneficial as it leads to high ductile behavior with the same degree of strength enhancement. The compressive response of PET FRP-confined concrete has been studied in circular columns, however, for non-circular columns it needs to be studied in detail. This study is aimed at developing an understanding of the compressive behavior of PET FRP-confined concrete in square and rectangular concrete cross-sections. Two experimental studies were performed at the Sirindhorn International Institute of Technology, Thammasat University. In first study, a total of 54 PET FRP-confined plain concrete circular, square and rectangular small scaled specimens were tested in uni-axial compression. The parameters considered were the number of FRP layers, corner radii and cross-section shape. In second study, the combined effect of internal steel reinforcement and externally wrapped PET FRP was investigated in detail by testing a total of 32 small square and rectangular RC column specimens. Articulated in seven parts, the dissertation presents the findings of above two experimental studies in detail. The experimental results indicated that, because of low elastic modulus, significant strength softening was observed in plain concrete square and rectangular cross-sections compared to the circular one. Unlike other commonly used FRPs (carbon FRP, glass FRP and aramid FRP) with low rupture strain and high elastic modulus, PET FRP confinement efficiently controlled the softening response by redistribution of internal damage of concrete core and displayed a hardening response until failure. PET FRP-confinement also resulted in significa

We give a method for constructing infinite families of dense (or eventually likely dense) Cayley digraphs of finite Abelian groups. The diameter of the digraphs is obtained by means of the related minimum distance diagrams. A dilating technique for these diagrams, which can be used for any degree of the digraph, is applied to generate the digraphs of the family. Moreover, two infinite families of digraphs with distinguished metric properties will be given using these methods. The first family contains digraphs with asymptotically large ratio between the order and the diameter as the degree increases (moreover it is the first known asymptotically dense family). The second family, for fixed degree d = 3, contains digraphs with the current best known density., Peer Reviewed, Postprint (author's final draft)

Identification of the cellular players and molecular messengers that communicate neuronal activity to the vasculature driving cerebral hemodynamics is important for (1) the basic understanding of cerebrovascular regulation and (2) interpretation of functional Magnetic Resonance Imaging (fMRI) signals. Using a combination of optogenetic stimulation and 2-photon imaging in mice, we demonstrate that selective activation of cortical excitation and inhibition elicits distinct vascular responses and identify the vasoconstrictive mechanism as Neuropeptide Y (NPY) acting on Y1 receptors. The latter implies that task-related negative Blood Oxygenation Level Dependent (BOLD) fMRI signals in the cerebral cortex under normal physiological conditions may be mainly driven by the NPY-positive inhibitory neurons. Further, the NPY-Y1 pathway may offer a potential therapeutic target in cerebrovascular disease.

Conclusion This is the first controlled study of balloon sinuplasty's long-term efficacy with the follow-up time over 5 years. The results are in accordance with a previous 2-year-follow-up study. Both techniques retained the efficacy and patient satisfaction on average 6 years after the surgery. Background Endoscopic sinus surgery (ESS) and balloon sinuplasty are considered as a treatment for chronic rhinosinusitis (CRS) after a failure of conservative therapy. High cost and lack of long-term follow-up studies restrain the use of balloon sinuplasty. Objective The aim of this study was to compare long-term efficacy and satisfaction in CRS patients who had undergone maxillary sinus operation with either balloon sinuplasty or ESS technique. Previous or additional sinonasal operations were exclusion criteria. Materials and methods Study patients were recruited from 208 CRS-patients who underwent either ESS or balloon sinuplasty. Patients with nasal polyposis (gradus >= 2), previous sinonasal surgery, unilateral disease, or immune deficiency were excluded. Altogether 45 patients in the ESS group and 40 patients in the balloon group were included. Of these, 30 and 28, respectively, answered to a phone interview held on average 6 years after primary surgery. Symptom reduction and long-term satisfaction were evaluated by using symptom scores of 19 parameters altogether. Results Both groups experienced improvement in symptoms and were equally satisfied with the operation. The number of patient-reported acute exacerbations was higher among the balloon dilated patients. Also, the reduction of thick nasal discharge was less evident in the balloon sinuplasty group. Four patients in the balloon sinuplasty group underwent revision surgery. There were no revisions in the ESS group.

We establish pathwise continuity properties of solutions to a stochastic Volterra equation with an additive noise term given by a local martingale. The deterministic part is governed by an operator with an H∞-calculus and a scalar kernel. The proof relies on the dilation theorem for positive definite operator families on a Hilbert space., Analysis

Résumé : Cette étude examine l'impact de la taille et de la gradation de particules sur les corrélations théoriques et empiriques existantes les plus connues entre la résistance au cisaillement et le comportement dilatatant des matériaux granulaires en condition de déformation plane et en compression triaxiale drainée. À cette fin, 276 tests de cisaillements symétriques directs et 35 tests de compressions triaxiales drainées ont été menés sur des échantillons composés de billes de basalte (particules rondes), et de sables constitués de particules angulaires (sable de Péribonka et sable d'Eastmain) sur une échelle de 63 µm à 2000 µm afin d'évaluer leur résistance au cisaillement et leur comportement de dilatance sur une vaste échelle de pressions normales et de densités relatives initiales. Premièrement, la fiabilité et l'applicabilité des limites de mesure à l’aide de tests physiques de cisaillements symétriques directs dans l'interprétation de la résistance au cisaillement frictionnel en déformation plane des matériaux granulaires ont été discutées et confirmées par l'usage du code informatique DEM, SiGran. L'accent a été particulièrement mis sur la validation du modèle DEM au moyen de comparaison des résultats des simulations DEM avec leurs équivalents physiques à une échelle macro. Les résultats virtuels DSA sont abordés du point de vue de la coaxialité entre les principales tensions et les principales directions des paliers de pression ainsi que de la déviation de la direction d'extension nulle à partir de la direction horizontale. Les résultats numériques fournissent également des données quantitatives sur les différentes formes d'énergie consommées durant le cisaillement confirmées par d'autres résultats physiques et numériques publiés. Sur la base des postulats précédents, un examen minutieux des résultats des essais de cisaillements directs et de données issues de la littérature a été accompli afin d'évaluer la fiabilité des formules empiriques bien connues, The present study examines more closely the potential impact of particle size and gradation on the most famous existing theoretical and empirical correlations between the shear strength and the dilation behavior of granular materials in plane strain and drained triaxial compression conditions. For this purpose, 276 symmetrical direct shear and 35 drained triaxial compression tests have been carried out on samples made up of basalt beads (rounded particles), and sands consisting of angular particles (Péribonka sand and Eastmain sand) in the range of 63 µm to 2000 µm to evaluate their shear resistance and dilation behavior over a wide range of normal pressures and initial relative densities. First, the reliability and applicability of boundary measurements in physical symmetrical direct shear tests to interpret the plane strain frictional shearing resistance of granular material have been discussed and confirmed using DEM computer code SiGran. Particular emphasis is placed on the validation of the DEM model by comparing the results of DEM simulations with their physical counterparts at the macro-scale. The virtual DSA results are discussed in terms of the coaxiality between the principal stresses and the principal strains increments directions as well as the deviation of the zero extension direction from the horizontal direction. The numerical results also provide quantitative data on different forms of energy consumed during shearing confirming other published physical and numerical results found in the literature. Following the assumptions above, a close scrutiny of symmetrical direct shear test results and strength and dilation data from the literature have been done to evaluate the reliability of well-known empirical Bolton’s and Collins et al.’s formulations with their commonly used constants in plane strain condition. The study shows that an application of empirical shear strength-dilation relationships with the constants proposed by Bolton (1986) and

The freeze-thaw durability of carbonate aggregates can vary greatly from durable to highly susceptible to freeze-thaw distress. Using nondurable aggregate in concrete pavement exposed to freeze-thaw cycles may lead to serious distress and greatly decrease the pavement’s service life. The testing needed to identify freeze-thaw durable aggregates can take several months to complete. The main objective of this study was to develop a reliable, quick test method for determining the freeze-thaw resistance of carbonate quarried aggregates in Indiana using the Hydraulic Fracture Test (HFT) equipment. Aggregate samples collected from 18 quarried carbonate sources from across Indiana that represented a range of freeze-thaw performance were subjected to HFT using the existing MnDOT HFT equipment and the newly developed INDOT HFT equipment. Aggregates from the same sources also were used to produce concrete beams that were subjected to the INDOT modified AASHTO T161-B freeze-thaw test (ITM 210) which evaluates the dilation of concrete beams exposed to freeze-thaw cycles. The experimental data were analyzed statistically and linear regression models were developed to predict the average percent dilation and the durability factor of freeze-thaw test beams using parameters obtained from HFT results. Comparing the modeled and measured test results, the favored model predicts dilations based on the INDOT HFT results. These modeled dilations, when compared to measured dilations gave an adjusted R2 value of 0.85, indicating the model has a high degree of certainty. The modified INDOT HFT equipment, refined test procedures and data analysis developed during this study are recommended as screening tools for predicting AASHTO T161/ASTM C666 FT test results in 8-days. Further testing is recommended to refine and validate the models before they are fully implemented as an acceptance standard.

We present a database client software-Neurovascular Network Explorer 1.0 (NNE 1.0)-that uses MATLAB(®) based Graphical User Interface (GUI) for interaction with a database of 2-photon single-vessel diameter measurements from our previous publication (Tian et al., 2010). These data are of particular interest for modeling the hemodynamic response. NNE 1.0 is downloaded by the user and then runs either as a MATLAB script or as a standalone program on a Windows platform. The GUI allows browsing the database according to parameters specified by the user, simple manipulation and visualization of the retrieved records (such as averaging and peak-normalization), and export of the results. Further, we provide NNE 1.0 source code. With this source code, the user can database their own experimental results, given the appropriate data structure and naming conventions, and thus share their data in a user-friendly format with other investigators. NNE 1.0 provides an example of seamless and low-cost solution for sharing of experimental data by a regular size neuroscience laboratory and may serve as a general template, facilitating dissemination of biological results and accelerating data-driven modeling approaches.

We study the crossed product C⁎C⁎-algebra associated to injective endomorphisms, which turns out to be equivalent to study the crossed product by the dilated automorphism. We prove that the dilation of the Bernoulli p -shift endomorphism is topologically free. As a consequence, we have a way to twist any endomorphism of a DD-absorbing C⁎C⁎-algebra into one whose dilated automorphism is essentially free and have the same K -theory map than the original one. This allows us to construct purely infinite crossed products C⁎C⁎-algebras with diverse ideal structures.

An oil pipe buried under needs to be checked for their current quality before oil transportation takes place through it. The method involved for all these days were manual using

The typical shear behaviour of rough joints has been studied under constant normal stress or zero normal stiffness boundary conditions (CNL), but recent studies have shown that this boundary condition may not replicate more practical situations, and that constant normal stiffness (CNS) is a more appropriate boundary condition to describe the stress-strain response of field joints. Unlike CNL conditions, a limited amount of data under CNS boundary conditions is available to date. In addition to the effect of boundary conditions, the shear behaviour of a rough joint also depends on its surface properties and initial stress acting on its interface. Despite this, exactly how these parameters affect the shear behaviour of joints is not fully understood because the stress-strain response of joints is governed by non-uniform asperity damage and the resulting gouge that accumulates on their interfaces. Therefore, an attempt has been made in this study to enhance our fundamental understanding of asperity deformation through a series of CNS shear tests that were conducted on replicas of three rough tensile (natural) joints at a range of initial normal stresses that varied from 0.4 to 1.6 MPa. Based on the laboratory investigation, a novel 3D characterisation method was proposed to quantify the role of the asperity damage and distribution of gouge material on the surfaces of rough rock joints under CNS direct shearing. A 3D laser scanner was used to digitise the joints, and characterisation was conducted based on the scanned models before and after the shear tests. This method demonstrated how zones of asperity damage are formed and gouge material is distributed onto the surfaces of sheared joints that are related to initial normal stresses and surface roughness, in terms of a colour spectrum and contour maps which show how the asperity heights deviate from the original profile. The results of this characterisation showed that the spatial distribution of asperity damage and go

CityGML is a standardized data format used to store the semantic information and geometries of buildings and other object classes of 3D city models. The Level of Detail of current state of the art city models (LoD2) is not sufficient for accurate environmental simulations like noise, the solar potential of windows and other types of analyses. An LoD3 building model represents the full architectural exterior of a building with balconies, windows and so forth. The generation of these models needs to be automated as it is otherwise infeasible due to the required high amount of manual labour. In the architectural world, detailed building models are created in IFC format. This thesis shows that it is possible to automatically generate valid and semantically rich CityGML LoD3 building models directly from IFC models. Also an initial investigation is done on the possibilities for the conversion of IFC models to CityGML LoD4. For the conversion the semantic and geometric validity requirements are determined for CityGML. A methodology for the conversion is developed and a prototype implementation is made to prove the effectiveness of the conversion. The conversion consists of three parts: 1) The extraction and mapping of IFC semantics to CityGML semantics; 2) A geometric generalization which extracts the exterior shell using a transformation based on Boolean and morphological operations; 3) Semantic and geometric refinements which optimize the model for analyses. The developed prototype is able to successfully convert IFC models to CityGML LoD3. All the resulting models were geometrically validated according to the ISO19107 standard, and semantics were checked manually. Few improper semantics occur in the output due to missing semantics in IFC. For example, there are no semantics for balconies or dormers in IFC. Recommendations are given to improve the alignment between the two formats. For IFC additional semantics are recommended whereas it is important for CityGML to speci, Geomatics, GIS technology, OTB Research Institute for the Built Environment

Chronic pancreatitis (CP)-related common bile duct (CBD) strictures are more difficult to treat endoscopically compared with benign biliary strictures because of their nature, particularly in patients with calcific CP. Before any attempt at treatment, malignancy must be excluded. Single plastic stents can be used for immediate symptom relief and as "bridge to surgery and/or bridge to decision," but are not suitable for definitive treatment of CP-related CBD strictures because of long-term poor results. Temporary simultaneous placement of multiple plastic stents has a high technical success rate and provides good long-term results.

The stretch factor and maximum detour of a graph G embedded in a metric space measure how well G approximates the minimum complete graph containing G and the metric space, respectively. In this paper we show that computing the stretch factor of a rectilinear path in L 1 plane has a lower bound of Ω(n log n) in the algebraic computation tree model and describe a worst-case O(σn log 2 n) time algorithm for computing the stretch factor or maximum detour of a path embedded in the plane with a weighted fixed orientation metric defined by σ < 2 vectors and a worst-case O(n log d n) time algorithm to d < 3 dimensions in L 1-metric. We generalize the algorithms to compute the stretch factor or maximum detour of trees and cycles in O(σn log d+1 n) time. We also obtain an optimal O(n) time algorithm for computing the maximum detour of a monotone rectilinear path in L 1 plane.

GPU architectures offer a significant opportunity for faster morphological image processing, and the NVIDIA CUDA architecture offers a relatively inexpensive and powerful framework for performing these operations. However, the generic morphological erosion and dilation operation in the CUDA NPP library is relatively naive, and performance scales expensively with increasing structuring element size. The objective of this work is to produce a freely available GPU capability for morphological operations so that fast GPU processing can be readily available to those in the morphological image processing community. Open-source extensions to CUDA (hereafter referred to as LTU-CUDA) have been produced for erosion and dilation using a number of structuring elements for both 8 bit and 32 bit images. Support for 32 bit image data is a specific objective of the work in order to facilitate fast processing of image data from 3D range sensors with high depth precision. Furthermore, the implementation specifically allows scalability of image size and structuring element size for processing of large image sets. Images up to 4096 by 4096 pixels with 32 bit precision were tested. This scalability has been achieved by forgoing the use of shared memory in CUDA multiprocessors. The vHGW algorithm for erosion and dilation independent of structuring element size has been implemented for horizontal, vertical, and 45 degree line structuring elements with significant performance improvements over NPP. However, memory handling limitations hinder performance in the vertical line case providing results not independent of structuring element size and posing an interesting challenge for further optimisation. This performance limitation is mitigated for larger structuring elements using an optimised transpose function, which is not default in NPP, and applying the horizontal structuring element. LTU-CUDA is an ongoing project and the code is freely available at https://github.com/VictorD/LTU-CUDA., Validerad; 2012; 20120603 (mjt), VSB - Vision Systems Business Development Platform