62 research outputs found
Sobre equações elÃpticas e aplicações /
Orientador : João Batista de Mendonça XavierDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Exatas, Programa de Pós-Graduação em Matemática Aplicada. Defesa: Curitiba, 2007Inclui bibliografi
Sobre equações elÃpticas e aplicações /
Orientador : João Batista de Mendonça XavierDissertaçao (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Exatas, Programa de Pós-Graduação em Matemática Aplicada. Defesa: Curitiba, 2007Inclui bibliografi
Correlation between central corneal thickness and intraocular pressure peak and fluctuation during the water drinking test in glaucoma patients
OBJECTIVE: To investigate the correlation between central corneal thickness and outflow facility assessed by intraocular pressure peak and fluctuation during the water drinking test. METHODS: Fifty-five newly diagnosed primary open-angle glaucoma patients submitted to central corneal thickness measurements and water drinking test were enrolled in this retrospective study.;. Patients were divided into three groups according to their central corneal thickness. Pearson's Correlation test was performed in the groups with lower and higher pachymetric values. RESULTS: The mean age was 65,65 ± 28,28 years; 63,63% were female and 52,72% were caucasian. The mean central corneal thickness was 544,32 ± 36,86 µm, and the mean baseline intraocular pressure was 23,36 ± 6,26 mmHg. During the water drinking test, the mean intraocular pressure peak and mean intraocular pressure fluctuation were 30,43 ± 8,13 mmHg and 31,46 ± 18,46%, respectively. No relevant correlation was detected between the central corneal thickness and the intraocular pressure peak (r² = 0,021) or between the central corneal thickness and the intraocular pressure fluctuation (r² = 0,011). Group 1 presented a mean central corneal thickness of 505,81 ± 13,86 µm, and Group 3 was 583,55 ± 27,87 µm (p = 0,001). The mean intraocular pressure peak was 31,05 ± 9,05 mmHg and 27,83 ± 4,92 mmHg in Group 1 and in Group 3, respectively (p = 0,193). The difference of intraocular pressure fluctuation was not statistically significant between Group 1 (mean 28,47±16,25%) and Group3 (mean 33,27 ± 21,27%) (p = 0,43). CONCLUSION: In our case series, no correlation was found between central corneal thickness and water drinkingtest results
Analysis of neuroretinal rim distribution and vascular pattern in eyes with presumed large physiological cupping: a comparative study
Background: To investigate possible differences in neuroretinal rim distribution, vascular pattern, and peripapillary region appearance between eyes with presumed large physiological optic disc cupping (pLPC) and eyes with minimal optic disc excavation.Methods: We prospectively enrolled consecutive subjects with pLPC and individuals with minimal excavation (optic disc excavation within normal limits; control group). All eyes had normal visual fields and untreated intraocular pressure (IOP) = 0.6 and >= 30 months of follow-up with no evidence of glaucomatous neuropathy. for controls, VCDR was limited to <= 0.5. We compared ocular signs and characteristics related to the neuroretinal rim distribution, vascular pattern, peripapillary region appearance and disc size between groups. Whenever both eyes were eligible, one was randomly selected for analysis.Results: A total of 74 patients (mean age, 45.6 +/- 14.9 years) with pLPC and 45 controls (mean age, 44.8 +/- 11.6 years) were enrolled (p = 0.76). Median disc size and VCDR was significantly larger in eyes with pLPC compared to controls (p < 0.01). the proportion of eyes with violation of the ISNT rule, laminar dot sign, nasal shifting of the central vessels, nasal excavation and baring of circumlinear vessel was significantly greater in the eyes with pLPC compared to controls (p < 0.01). There were no significant differences regarding the proportions of eyes with peripapillary atrophy between groups (p < 0.09). Finally, disc size was significantly associated with VCDR (r(2) = 0.47, p < 0.01), with an increase of 0.21 in VCDR for each 1 mm(2) in disc area.Conclusion: Compared to normal controls, eyes with pLPC may present a higher proportion of optic nerve head findings frequently observed in glaucomatous eyes. This seems to be explained in part by the larger discs found in these eyes. We believe care should be taken while classifying them as glaucomatous or not based solely on these characteristics.Universidade Federal de São Paulo, Dept Ophthalmol, BR-04021001 São Paulo, BrazilHosp Med Olhos, Glaucoma Unit, BR-06018180 Osasco, SP, BrazilMayo Clin, Dept Ophthalmol, Jacksonville, FL 32224 USAUniversidade Federal de São Paulo, Dept Ophthalmol, BR-04021001 São Paulo, BrazilWeb of Scienc
Eyes with Large Disc Cupping and Normal Intraocular Pressure: Using Optical Coherence Tomography to Discriminate Those With and Without Glaucoma
We evaluated the ability of spectral-domain optic coherence tomography (SD-OCT) to differentiate large physiological optic disc cupping (LPC) from glaucomatous cupping in eyes with intraocular pressure (IOP) within the normal range. We prospectively enrolled patients with glaucoma or presumed LPC. Participants  had optic discs with confirmed or suspected glaucomatous damage (defined as a vertical cup-to-disc ratio≥0.6), and all eyes had known untreated IOP<21 mmHg. For glaucomatous eyes, a reproducible glaucomatous visual field (VF) defect was required. LPC eyes required normal VF and no evidence of progressive glaucomatous neuropathy (follow-up≥30 months). Peripapillary retinal nerve fiber layer (pRNFL) and macular ganglion cell complex (GCC) thicknesses were obtained using SD-OCT. For all studied parameters of pRNFL and GCC thicknesses, eyes with glaucoma (n=36) had significantly thinner values compared to eyes with LPC (n=71; P<0.05 for all comparisons). In addition, pRNFL parameters had sensitivity of 66.7% and specificity of 83.1%, and GCC parameters had sensitivity of 61.2% and specificity of 81.7%. The combination of the two analyses increased the sensitivity to 80.6%. In conclusion, while evaluating patients with large optic disc cupping and IOP in the statistically normal range, SD-OCT had only limited diagnostic ability to differentiate those with and without glaucoma. Although the diagnostic ability of the pRNFL and the GCC scans were similar, these parameters yielded an increase in sensitivity when combined, suggesting that both parameters could be considered simultaneously in these cases
Risk Factors for Optic Disc Hemorrhage in the Low-Pressure Glaucoma Treatment Study
PurposeTo investigate risk factors for disc hemorrhage detection in the Low-Pressure Glaucoma Treatment Study.DesignCohort of a randomized, double-masked, multicenter clinical trial.MethodsLow-Pressure Glaucoma Treatment Study patients with at least 16 months of follow-up were included. Exclusion criteria included untreated intraocular pressure (IOP) of more than 21 mm Hg, visual field mean deviation worse than −16 dB, or contraindications to study medications. Patients were randomized to topical treatment with timolol 0.5% or brimonidine 0.2%. Stereophotographs were reviewed independently by 2 masked graders searching for disc hemorrhages. The main outcomes investigated were the detection of disc hemorrhage at any time during follow-up and their recurrence. Ocular and systemic risk factors for disc hemorrhage detection were analyzed using the Cox proportional hazards model and were tested further for independence in a multivariate model.ResultsTwo hundred fifty-three eyes of 127 subjects (mean age, 64.7 ± 10.9 years; women, 58%; European ancestry, 71%) followed up for an average ± standard deviation of 40.6 ± 12 months were included. In the multivariate analysis, history of migraine (hazard ratio [HR], 5.737; P = .012), narrower neuroretinal rim width at baseline (HR, 2.91; P = .048), use of systemic β-blockers (HR, 5.585; P = .036), low mean systolic blood pressure (HR, 1.06; P = .02), and low mean arterial ocular perfusion pressure during follow-up (HR, 1.172; P = .007) were significant and independent risk factors for disc hemorrhage detection. Treatment randomization was not associated with either the occurrence or recurrence of disc hemorrhages.ConclusionsIn this cohort of Low-Pressure Glaucoma Treatment Study patients, migraine, baseline narrower neuroretinal rim width, low systolic blood pressure and mean arterial ocular perfusion pressure, and use of systemic β-blockers were risk factors for disc hemorrhage detection. Randomization assignment did not influence the frequency of disc hemorrhage detection
Molecular Diagnostic Testing on Post Mortem Inspection and Rulings on Bovine Tuberculosis — An Experience Report in Brazil
Suppression of small baryonic structures due to a primordial magnetic field
We investigate the impact of the existence of a primordial magnetic field on
the filter mass, characterizing the minimum baryonic mass that can form in dark
matter (DM) haloes. For masses below the filter mass, the baryon content of DM
haloes are severely depressed. The filter mass is the mass when the baryon to
DM mass ratio in a halo is equal to half the baryon to DM ratio of the
Universe. The filter mass has previously been used in semianalytic calculations
of galaxy formation, without taking into account the possible existence of a
primordial magnetic field. We examine here its effect on the filter mass. For
homogeneous comoving primordial magnetic fields of or 2 nG and a
reionization epoch that starts at a redshift and is completed at
, the filter mass is increased at redshift 8, for example, by factors
4.1 and 19.8, respectively. The dependence of the filter mass on the parameters
describing the reionization epoch is investigated. Our results are particularly
important for the formation of low mass galaxies in the presence of a
homogeneous primordial magnetic field. For example, for B_0\sim 1\nG and a
reionization epoch of and , our results indicate that
galaxies of total mass M\sim5 \times 10^8\msun need to form at redshifts
, and galaxies of total mass M\sim10^8\msun at redshifts
.Comment: 5 pages, 3 figures, accepted for publication in MNRA
Molecular Techniques for Identification of Species of the Mycobacterium tuberculosis Complex: The use of Multiplex PCR and an Adapted HPLC Method for Identification of Mycobacterium bovis and Diagnosis of Bovine Tuberculosis
Mapeamento de áreas agrÃcolas na safra de verão a partir de imagens Landsat frente aos dados oficiais
O mapeamento das áreas agrÃcolas de uma determinada região é de fundamental importância, uma vez que se pode conhecer as condições das lavouras e inferir sobre produção e produtividade. O agronegócio exerce grande influência em diferentes setores da economia, tendo repercussões, também, sobre a dinâmica social. Assim, informações antecipadas sobre as condições das lavouras permitem ao governo e à diversas instituições ligadas ao agronegócio o planejamento de polÃticas de apoio à produção agrÃcola, levando à maximização dos lucros ou minimização de possÃveis prejuÃzos. Nesse contexto, tecnologias de sensoriamento remoto e geoprocessamento assumem importância Ãmpar, já que podem monitorar, mapear e quantificar as áreas de produção agrÃcola. O bjetivou-se com o presente trabalho mapear as áreas agrÃcolas do municÃpio de Londrina em cinco safras de verão, confrontando os resultados obtidos com os dados oficiais. Foram utilizadas imagens Landsat 5 e 7 de cinco diferentes safras. Realizou-se o processamento digital e classificação do uso do solo das imagens por meio do software Spring e classificador Maxver, respectivamente. Os resultados obtidos apontaram baixa precisão da metodologia utilizada, de modo que houve grande superestimação dos dados em duas safras e subestimação dos dados em três safras. Conclui-se que a metodologia utilizada possui grande potencial de aplicabilidade desde que atendidos alguns pressupostos, como maior disponibilidade das imagens, melhoria na qualidade das imagens e disponibilização de dados oficiais seriados em safra de verão e inverno
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