Migraciones internacionales en Belice. Una vision etno-demografica

Incluye Bibliografía

Strategic vision for ports: the year 2010

This month's FAL leading article is Larry Burkhalter's swan song as a United Nations staff member. Larry has served ECLAC and the UN for more than 22 years and has been the Commission's guiding light in maritime transport and port issues for the most part of that time.

Transportation in the 21st century: a vision for integration

The Third Western Hemisphere Transportation Ministerial meeting was held in New Orleans, Lousiana, United States, from 14 to 16 December 1998, under the theme Transportation in the 21st Century: A Vision for Integration. The meeting was attended by Ministers and heads of delegations from 33 countries of the Americas, representatives of various international organizations and business sector of the Continent. The current issue of the Bulletin provides the complete text of the Ministerial Declaration. For additional information, contact José María Rubiato: e-mail jrubiato@eclac.cl

Impairment of color spatial vision in chronic alcoholism measured by psychophysical methods

We used psychophysical tests to evaluate spatial vision in 15 subjects with a clinical history of chronic alcoholism by measuring luminance contrast sensitivity and color discrimination. The subjects were initially subjected to clinical inquiry and ophthalmological exam. Subjects then performed psychophysical tests to measure spatial contrast thresholds using sine wave gratings of different spatial frequencies and contrasts and chromatic discrimination thresholds using the Mollon-Reffin test. For the analysis, subjects were divided into three groups according to age and compared with age-matched controls. Ten subjects had some degree of color vision loss, which was quite severe in seven cases. All subjects had normal luminance contrast sensitivity. The results suggest that color vision changes related to chronic alcoholism can occur in the absence of impairment of spatial luminance contrast sensitivity and thus is an important aspect to be considered in the clinical evaluation of this condition.

Color vision loss in patients treated with chloroquine

Pacientes que fazem uso de cloroquina ou hidróxi-cloroquina, drogas que são freqüentemente administradas para o tratamento de artrite reumatóide, lúpus eritrematoso ou malária, podem sofrer alterações na visão de cores e na sensibilidade de contraste. O presente estudo avaliou a função visual destes pacientes em um estudo conjunto da Universidade de São Paulo (USP), em São Paulo, e da Universidade Federal do Pará (UFPA), em Belém. Trinta e dois pacientes usuários de cloroquina sem alterações no exame de fundo de olho foram avaliados em São Paulo (n=10, 38 a 71 anos, média=55,8 anos) e em Belém (n=22, 20 a 67 anos, média=40 anos). A dose acumulada de cloroquina prescrita foi de 45 a 430 g (média=213 g; dp=152 g) para o grupo de São Paulo, e de 36 a 540 g (média=174 g; dp=183 g) para o grupo de Belém. Os testes foram realizados monocularmente com o estado refracional corrigido. A discriminação de cor foi avaliada utilizando o Teste de Cor de Cambridge (CCT): o limiar de discriminação de cor foi mensurado primeiro nos eixos protano, deutano e tritano, e em seqüência, três elipses de MacAdam foram determinadas. A visão de cores dos pacientes também foi avaliada com testes de arranjo de cores: o teste de 100 matizes de Farnsworth-Munsell (FM100), o D15 de Farnsworth-Munsell, e o teste Lanthony Dessaturado (D15d). A sensibilidade de contraste foi também medida com grades senoidais preto-e-brancas em 22 pacientes. Os resultados foram comparados com controles sem patologias oftalmológicasou neuro-oftalomológicas. 24 pacientes apresentaram discromatopsia adquirida, com perdas seletivas (11 pessoas) ou difusas (13 pessoas). Embora as perdas estivessem presentes no FM100, não houve correlação entre o escore de erro do FM100 e a área elíptica medida pelo CCT. Além disso, três pacientes que tiveram escores normais no FM100 falharam para alcançar limiares normais no CCT. O teste de Lanthony foi menos sensível do que os outros dois testes, tal que falhou em indicar perda em cerca de metade dos pacientes afetados, e o D15 foi o teste menos sensível, deixando de indicar déficits em 9 de 10 pacientes. A sensibilidade de contraste esteve dentro dos valores normais para pacientes submetidos a este teste. A extensão das perdas na discriminação de cores foi positivamente correlacionada com a dose acumulada. O CCT é recomendado para o acompanhamento destes pacientes, pois forneceu dados quantitativos que podem ser diretamente interpretados no espaço cromático da CIE (Commission Internationelle d'Éclairage).

Machine vision to identify broiler breeder behavior

Animal behavioral parameters can be used to assess welfare status in commercial broiler breeders. Behavioral parameters can be monitored with a variety of sensing devices, for instance, the use of video cameras allows comprehensive assessment of animal behavioral expressions. Nevertheless, the development of efficient methods and algorithms to continuously identify and differentiate animal behavior patterns is needed. The objective this study was to provide a methodology to identify hen white broiler breeder behavior using combined techniques of image processing and computer vision. These techniques were applied to differentiate body shapes from a sequence of frames as the birds expressed their behaviors. The method was comprised of four stages: (1) identification of body positions and their relationship with typical behaviors. For this stage, the number of frames required to identify each behavior was determined; (2) collection of image samples, with the isolation of the birds that expressed a behavior of interest; (3) image processing and analysis using a filter developed to separate white birds from the dark background; and finally (4) construction and validation of a behavioral classification tree, using the software tool Weka (model 148). The constructed tree was structured in 8 levels and 27 leaves, and it was validated using two modes: the set training mode with an overall rate of success of 96.7%, and the cross validation mode with an overall rate of success of 70.3%. The results presented here confirmed the feasibility of the method developed to identify white broiler breeder behavior for a particular group of study. Nevertheless, more improvements in the method can be made in order to increase the validation overall rate of success. (C) 2013 Elsevier B.V. All rights reserved.

TACTILE CARTOGRAPHY EXPERIENCES IN BRAZIL: METHODOLOGIES AND DIDACTICAL MATERIAL WITH TECHNOLOGICAL RESOURCES FOR INCLUSION OF BLIND AND LOW VISION STUDENTS

The tactile cartography is an area of Cartography that aims the development of methodologies and didactical material to work cartographic concepts with blind and low vision people. The main aim of this article is to present the experience of Tactile Cartography Research Group from Sao Paulo State University (UNESP), including some didactical material and courses for teachers using the System MAPAVOX. The System MAPAVOX is software developed by our research group in a partnership with Federal University of Rio de Janeiro (UFRJ) that integrates maps and models with a voice synthesizer, sound emission, texts, images and video visualizing for computers. Our research methodology is based in authors that have in the students the centre of didactical activity such as Ochaita and Espinosa in [1], which developed studies related to blind children's literacy. According to Almeida the child's drawing is, thus, a system of representation. It isn't a copy of objects, but interpretation of that which is real, done by the child in graphic language[2]. In the proposed activities with blind and low vision students they are prepared to interpret reality and represent it by adopting concepts of graphic language learned. To start the cartographic initialization it is necessary to use personal and quotidian references, for example the classroom tactile model or map, to include concepts in generalization and scale concerning to their space of life. During these years many case studies were developed with blind and low vision students from Special School for Hearing Impaired and Visually Impaired in Araras and Rio Claro, Sao Paulo - Brazil. The most part of these experiences and others from Brazil and Chile are presented in [3]. Tactile material and MAPAVOX facilities are analysed by students and teachers who contribute with suggestions to reformulate and adapt them to their sensibility and necessity. Since 2005 we offer courses in Tactile Cartography to prepare teachers from elementary school in the manipulation of didactical material and attending students with special educational needs in regular classroom. There were 6 classroom and blended courses offered for 184 teachers from public schools in this region of the Sao Paulo state. As conclusion we can observe that methodological procedures centred in the blind and low vision students are successful in their spatial orientation if use didactical material from places or objects with which they have significant experience. During the applying of courses for teachers we could see that interdisciplinary groups can find creative cartographic alternatives more easily. We observed too that the best results in methodological procedures were those who provided concreteness to abstract concepts using daily experiences.

Projeto de um transdutor binocular utilizando extensometria e aplicação na pesagem rodoviária

With the passage of time, the variety of companies from each branch has gradually grown throughout the country. As a consequence, the logistics to attend to such demand has grown in the same proportion. One factor to highlight about this rapid growth is the increase of freight vehicles roaming the roads, often carrying loads over the limit established by law. At first it may seem that this would not bring any problem, however, note that an excessive number of overloads ends up deteriorating the asphalt, causing ondulations, potholes and other imperfections on the roads, which can cause accidents. In addition, the money spent for the maintenance of the roads is high. Thinking about it, it was established by law a regulation that restricts the weight limit for these vehicles, through axle weighing, subject to a fine. With this control the road floor is preserved for longer, requiring less maintenance expenses. The weighing stations use load cells to display the inferred weight, these cells use strain gages in its construction. The following work presents a methodology to dimension a binocular load cell, its main elements and its dimensioning. Showing how different materials can affect the dimensioning, so that can work satisfactorily. It also presents an overview of how are the parameters for weighing, and fines

Machine vision and planning applied on assembby line of multiple products

This article describes the use of Artificial Intelligence (IA) techniques applied in cells of a manufacturing system. Machine Vision was used to identify pieces and their positions of two different products to be assembled in the same productive line. This information is given as input for an IA planner embedded in the manufacturing system. Therefore, initial and final states are sent automatically to the planner capable to generate assembly plans for a robotic cell, in real time.

Visual outcomes and pacient satisfaction follwing implantation of a supplementary multifocal IOL in patients undergoing cataract surgery

Purpose: To assess visual outcomes and patient satisfaction following implantation of the Sulcoflex® multifocal intraocular lens (IOL; Rayner Intraocular Lenses Ltd., Hove, UK) in a procedure combining capsular bag lens implantation with sulcus placement of the Sulcoflex® IOL. Setting: Instituto de Oftalmologia de Assis, Assis, SP, Brazil. Methods: Cataract patients > 45 years, with hyperopia ≥ 1.50 D and potential acuity measurement ≥ 20/30 undergoing Sulcoflex® multifocal IOL implantation were included. Monocular and binocular uncorrected near and distance visual acuity (VA) were evaluated at five days, one month, and three months postoperatively. Contrast sensitivity and refraction were measured in a subset of patients three months postoperatively. Patient satisfaction was assessed one month postoperative. Results: This non-consecutive case series comprised 25 eyes of 13 patients. Eleven eyes (52%) had pre-existing retinal pathologies. Monocular distance VA improved significantly at all follow-up visits. At final follow-up, 88% of eyes had monocular uncorrected distance VA (UDVA) of at least 20/25 and 24% had monocular UDVA of 20/20. All eyes had binocular UDVA of at least 20/25, and 58% had binocular UDVA of 20/20. Monocular uncorrected near vision (UNVA) was J1 in 68% of eyes and all patients had binocular UNVA of J1. Of all eyes studied, 92% and 58% achieved a spherical equivalent within 1 D and −0.5 D, respectively. The majority of patients reported satisfaction with visual outcomes. Complications included a postoperative intraocular pressure spike in four eyes. Conclusion: The Sulcoflex® multifocal IOL improves near and distance VA in cataract patients with retinal abnormalities and good VA potential.

Design of a Wireless Vision Sensor for Object Tracking in Wireless Vision Sensor Networks

The integration of CMOS cameras with embedded processors and wireless communication devices has enabled the development of distributed wireless vision systems. Wireless Vision Sensor Networks (WVSNs), which consist of wirelessly connected embedded systems with vision and sensing capabilities, provide wide variety of application areas that have not been possible to realize with the wall-powered vision systems with wired links or scalar-data based wireless sensor networks. In this paper, the design of a middleware for a wireless vision sensor node is presented for the realization of WVSNs. The implemented wireless vision sensor node is tested through a simple vision application to study and analyze its capabilities, and determine the challenges in distributed vision applications through a wireless network of low-power embedded devices. The results of this paper highlight the practical concerns for the development of efficient image processing and communication solutions for WVSNs and emphasize the need for cross-layer solutions that unify these two so-far-independent research areas.

Color vision impairment in type 2 diabetes assessed by the D-15d test and the Cambridge Colour Test

Color vision impairment emerges at early stages of diabetes mellitus type 2 (DM2) and may precede diabetic retinopathy or the appearance of vascular alterations in the retina. The aim of the present study was to compare the evaluation of the color vision with two different tests - the Lanthony desaturated D-15d test (a traditional color arrangement test), and the Cambridge Colour Test (CCT) (a computerized color discrimination test) - in patients diagnosed with DM2 without clinical signs of diabetic retinopathy (DR), and in sex- and age-matched control groups. Both color tests revealed statistically significant differences between the controls and the worst eyes of the DM2 patients. In addition, the degree of color vision impairment diagnosed by both tests correlated with the disease duration. The D-15d outcomes indicated solely tritan losses. In comparison, CCT outcomes revealed diffuse losses in color discrimination: 13.3% for best eyes and 29% for worst eyes. In addition, elevation of tritan thresholds in the DM2 patients, as detected by the Trivector subtest of the CCT, was found to correlate with the level of glycated hemoglobin. Outcomes of both tests confirm that subclinical losses of color vision are present in DM2 patients at an early stage of the disease, prior to signs of retinopathy. Considering the advantages of the CCT test compared to the D-15d test, further studies should attempt to verify and/or improve the efficiency of the CCT test.

A computer-controlled color vision test for children based on the Cambridge Colour Test

The present study aimed at providing conditions for the assessment of color discrimination in children using a modified version of the Cambridge Colour Test (CCT, Cambridge Research Systems Ltd., Rochester, UK). Since the task of indicating the gap of the Landolt C used in that test proved counterintuitive and/or difficult for young children to understand, we changed the target Stimulus to a patch of color approximately the size of the Landolt C gap (about 7 degrees Of Visual angle at 50 cm from the monitor). The modifications were performed for the CCT Trivector test which measures color discrimination for the protan, deutan and tritan confusion lines. Experiment I Sought to evaluate the correspondence between the CCT and the child-friendly adaptation with adult subjects (n = 29) with normal color vision. Results showed good agreement between the two test versions. Experiment 2 tested the child-friendly software with children 2 to 7 years old (n = 25) using operant training techniques for establishing and maintaining the subjects` performance. Color discrimination thresholds were progressively lower as age increased within the age range tested (2 to 30 years old), and the data-including those obtained for children-fell within the range of thresholds previously obtained for adults with the CCT. The protan and deutan thresholds were consistently lower than tritan thresholds, a pattern repeatedly observed in adults tested with the CCT. The results demonstrate that the test is fit for assessment of color discrimination in young children and may be a useful tool for the establishment of color vision thresholds during development.