4,536 research outputs found
Detection and resolution of normative conflicts in multi-agent systems : a literature survey
Peer reviewedPostprin
Analysis of the Disturbances Caused by Intraocular Forced Convection Mechanism Failure
In this chapter, we show the refractive error treatment result of a patient, the first author, who restarted in 2000, after a 4-year break, at the study start. According to previous publications, the treatment consists of rehydration and elimination of agglutinated, dehydrated and deposited metabolic residues in the cornea, the trabecular meshwork, the crystalline lens and the retina, as a consequence of the failure in the mechanism of intraocular mass transfer by forced convection. However, the forced movement of the metabolic mass to rehydrate one region can cause dehydration in another region. Therefore, the patient developed posterior and capsular cataract in their respective eyes, right and left. This dehydration, during the treatment, increases the difficulties for the success of the treatment. The first part is a chronological record of the most important components of the treatment. Then, the research method and the material used are discussed. The main symptoms and signs are analyzed and correlated with the failure of the mass transfer process and the accumulation of metabolic residues. The anatomy of binocular vision is analyzed as a part of the forced convection mechanism, and in conclusion, the report shows the main oculomotor functions, topographic mapping of corneas over an interval of 17 months
Intraocular Forced Convection Mechanism Defect as Probable Cause of Normal-Tension Glaucoma
This paper describes several pathologies associated with pathological movements that can cause physical effort on the optic nerve and damage to vision. The accumulation of intraocular metabolic residues increases ocular globe mass and can change its position in the orbit, as well as increase the cornea and crystalline, accommodation resistance, in addition to being able to increase the aqueous humor output resistance. A series of discreet pathologies may result in optic nerve impairment: cyclotorsion and saccadic movement, position in the orbit, and increased intraocular pressure. The cyclotorsion movements can be stimulated by the superior visual field restriction, due to the metabolic residue accumulation in the light transmission regions of this visual field, preventing correct fusion of the images
Detection of electronic nematicity using scanning tunneling microscopy
Electronic nematic phases have been proposed to occur in various correlated
electron systems and were recently claimed to have been detected in scanning
tunneling microscopy (STM) conductance maps of the pseudogap states of the
cuprate high-temperature superconductor Bi2Sr2CaCu2O8+x (Bi-2212). We
investigate the influence of anisotropic STM tip structures on such
measurements and establish, with a model calculation, the presence of a
tunneling interference effect within an STM junction that induces
energy-dependent symmetry-breaking features in the conductance maps. We
experimentally confirm this phenomenon on different correlated electron
systems, including measurements in the pseudogap state of Bi-2212, showing that
the apparent nematic behavior of the imaged crystal lattice is likely not due
to nematic order but is related to how a realistic STM tip probes the band
structure of a material. We further establish that this interference effect can
be used as a sensitive probe of changes in the momentum structure of the
sample's quasiparticles as a function of energy.Comment: Accepted for publication (PRB - Rapid Communications). Main text (5
pages, 4 figures) + Supplemental Material (4 pages, 4 figures
Evidence of widespread retinal dysfunction in patients with stargardt disease and morphologically unaffected carrier relatives
PURPOSE: To characterize contrast sensitivity (CS) across the visual field for two achromatic spatial-temporal frequencies in 21 families with Stargardt disease (STGD) and to correlate psychophysical impairment with patterns of change in multifocal electroretinography (mfERG). METHODS: Twenty-seven eyes from patients with STGD, 16 eyes from asymptomatic relatives, and 44 age-matched control eyes were included. Chromatic CS function was assessed by comparing protan, deutan, and tritan (Cambridge Color Test; Cambridge Research Systems Ltd., Rochester, UK) and anomaloscope measures (IF-2; Roland Consult, Wiesbaden, Germany). Achromatic CS measures were obtained with custom-made software in nine locations by using randomly interleaved staircases. The first task-low spatial frequency (LSF)-matched the known frequency-doubling method that is believed to activate the magnocellular pathway preferentially. The second included an intermediate spatial frequency (ISF, 3.5 cyc/deg). mfERGs (RETIscan; Roland Consult) were also obtained. Relatives were screened for ABCA4 mutations by ABCR400 microarray and direct sequencing. RESULTS: Central impairment of achromatic and chromatic CS (along the three isolation axes) was observed in STGD. LSF and ISF tasks revealed significant and widespread dysfunction in patients and their morphologically unaffected relatives, 80% of whom were found to be ABCA4 mutation carriers. Significant reduction of P1 amplitudes was also observed in both groups. CONCLUSIONS: CS function is impaired in patients with STGD at distinct spatial-temporal frequencies, which, in addition to the color vision deficits, suggests dual impairment of the magno- parvocellular pathways. STGD morphologically unaffected carriers may show patterns of psychophysical dysfunction that are mirrored by abnormal mfERG response
Concrete-to-concrete bond strength. Influence of the roughness of the substrate surface
An experimental study was performed to evaluate the bond strength between two concrete layers, for different techniques for increasing the roughness of the substrate surface. In a total of 25 slant shear specimens and 25 pull-off specimens the substrate surface was prepared by wire-brushing; sand-blasting; chipping with a light jackhammer; or were left as-cast against steel formwork. Three months later, the new concrete was added. Pull-off tests were performed to evaluate the bond strength in tension. Slant shear tests were conducted to quantify the bond strength in shear. Analysis of results indicated that: the highest value of bond strength was achieved with sand-blasting; pull-off tests are adequate to estimate the bond strength in situ; and pre-wetting the substrate surface does not seem to influence the bond strength.http://www.sciencedirect.com/science/article/B6V2G-4CMYMDN-3/1/b64e1833c354a3d441d24c410cb979d
Fracture of the posterior malleolus: an underdiagnosed condition
The ankle joint is the most commonly injured joint during sports activity. While ankle sprains occur more frequently, ankle fractures are less common. Due to its low incidence, the isolated fracture of the posterior malleolus still represents a diagnosis challenge. This article reports a case of a female with a posterior malleolus isolated fracture after falling while performing sports activity. Clinical examination and conventional radiography were consistent with diagnosis of a simple ankle sprain and the patient was discharged with a conservative approach for lateral ankle sprain. Due to persistent pain the patient return for additional examination, which the differential diagnosis revealed an isolated fracture of the posterior malleolus without displacement of the fragment. The patient was immobilized with a suropodalic splint for 4 weeks followed by additional conservative. At the fourth month of follow-up, the patient was asymptomatic and showed good clinical and functional outcomes. This case highlights the importance of a comprehensive medical history and detailed clinical examination which may reveal pathological features that require a differential diagnosis
Risk Management in Scrum Projects: A Bibliometric Study
This article presents a bibliometric study of Risk Management in Scrum Projects. It was carried out an analysis involving the ISI Web of Knowledge and Scopus databases, identifying the main authors, countries and periodicals. It also identified the most cited authors by the analyzed articles, in addition to the keywords most frequently cited. These analyzes were performed using the reference maps, which were generated by CiteSpace® software, which offers a set of features to support bibliometrics. The objective was to identify the current scenario research of Risk Management applied in Scrum Projects in order to offer a consistent basis of information to researchers. The research verified that, despite the importance of the research topic, few scientific studies have been identified, which brings the need for new researches on the subject
The Analyticity of a Generalized Ruelle's Operator
In this work we propose a generalization of the concept of Ruelle operator
for one dimensional lattices used in thermodynamic formalism and ergodic
optimization, which we call generalized Ruelle operator, that generalizes both
the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator
defined in [Bowen]. We suppose the alphabet is given by a compact metric space,
and consider a general a-priori measure to define the operator. We also
consider the case where the set of symbols that can follow a given symbol of
the alphabet depends on such symbol, which is an extension of the original
concept of transition matrices from the theory of subshifts of finite type. We
prove the analyticity of the Ruelle operator and present some examples
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