<p dir="ltr">General Purpose computing on Graphical Processing Units (GPGPU) has resulted in un-precedented levels of speedup over its CPU counterparts, allowing programmers to harness the computational power of GPU shader cores to accelerate other computing applications. But this style of acceleration is best suited for regular computations (e.g., linear algebra). Recent GPUs feature new Ray Tracing (RT) cores that instead speed up the irregular process of ray tracing using Bounding Volume Hierarchies. While these cores seem limited in functionality, recent works have shown that it is possible to leverage the acceleration of RT cores by restructuring irregular problems to resemble ray tracing queries. In this dissertation, we explore leveraging RT cores to accelerate general-purpose computations. We introduce RT-accelerated variations of algorithms and suggest enhancements for current implementations. First, we propose RT-DBSCAN, the first RT-accelerated DBSCAN implementation. We use RT cores to accelerate Density-Based Clustering of Applications with Noise (DBSCAN) by translating fixed-radius nearest neighbor queries to ray tracing queries. As the neighbor queries are the main performance bottleneck in DBSCAN, we find that leveraging the RT hardware results in speedups between 1.3x to 4x over current state-of-the-art, GPU-based DBSCAN implementations. Though the existing translation of nearest neighbor search (NNS) problems to ray tracing queries has been shown to be effective, it imposes a constraint on the search space for neighbors. Due to this, we can only use RT cores to accelerate fixed-radius NNS, which requires the user to set a search radius a priori and hence can miss neighbors. To remedy this, we propose TrueKNN, the first unbounded RT-accelerated neighbor search. We solve the k-nearest neighbor search problem by adopting an iterative approach where we incrementally grow the search space until all points have found their k neighbors. We show that our approach is orders of magnitude faster than existing approaches and can even be used to accelerate fixed-radius neighbor searches. The n-body problem involves calculating the effect of bodies on each other. n-body simulations are ubiquitous in the fields of physics and astronomy and notoriously computationally expensive. The naïve algorithm for n-body simulations has the prohibiting O(n2) time complexity. Reducing the time complexity to O(n · lg(n)), the tree-based Barnes-Hut algorithm approximates the effect of bodies beyond a certain threshold distance. In tree-based NNS, computation is restricted solely to the leaf nodes of the tree, whereas Barnes-Hut requires computation to occur at both the leaf and internal nodes of the tree. In this work, we reformulate the Barnes-Hut algorithm as a ray-tracing problem and implement it with NVIDIA OptiX. Our evaluation shows that the resulting system, RT-BarnesHut, outperforms current state-of-the-art GPU-based implementations.</p>

Bolted cores made of coated silicon steel sheets constitute a vital part of heavy electrical equipment for transformers, motors and turbogenerators. Bolted laminates are eminently suitable for facilitating smooth magnetic flux paths, but, unfortunately, they are unable to suppress interlaminate shearing caused by flexural vibration generating noise levels often exceeding 100 dB during operation. The resulting din and cacophony in the surrounding has become a major environmental concern. This thesis makes an attempt to develop theoretical, experimental and numerical models for evolving an effective stiffness approach enhancing the design and analysis underlying nonlinear flexure of bolted laminates. While large machine cores contain thousands of thin sheets bolted together along with end plates, this thesis reports the results obtained on two different assemblies. Two 375 mm long 60 mm wide and 10 mm thick plates assembled with 3, 4 or 5 bolts constitute the first configuration. The second one which is much more realistic comprises 80 coated 270 micron silicon steel sheets with end plates of 2 or 4 mm thickness held together by 3 or 5 bolts. Static 3 point bend tests on these bolted assemblies are followed by instrumented impact tests. Static bending tests highlight the role of frictional nonlinearity inducing a drop in the stiffness due to sliding between the plates. An experimentally determined effective modulus in the initial linear range is utilized for static and dynamic finite element simulations. Nonlinear response of bolted plates is simulated using contact elements in between the sliding plates, plates and the bolts heads. Since the first fundamental mode of vibration dominates the tribomechanical vibration induced noise, the primary focus is on the fundamental frequency in bending. There is generally a good overall agreement in all the results obtained through theory, experiment and FE simulation. Experiments, however, unveil quite complex nonlinear effects induced by friction and plasticity outside the scope of this thesis. However, the low amplitude response of bolted laminates which is reasonably well captured in this thesis represents the starting point for initiating a more elaborate effort for addressing large amplitude nonlinear flexure in bolted laminates. These findings shed light on estimating and controlling noise and vibration levels in heavy electric machines.

Foundry technology is an industrial sector, where progress is still the important aspect for reducing the environmental impact and increasing competitiveness. Master's thesis is focused on the possibilities of influencing residual strength of the core moulding mixtures with the biogenic binders, which forms a new group of binder systems.

<p>Chlorinated aliphatic hydrocarbons (CAH´s) were used widely within dry cleaning facilities and for metal degreasing until their toxicity was discovered. PCE is still used as dry cleaning liquid. Today CAH´s are found in soil environment at places where they have been used in the past. The CAH-concentration in trees growing on contaminated land has quite recently received attention as a cheap and effective way of assessing the extent of a CAH-contamination. The method has however, not been put into use in Sweden.</p><p>The aim of the study has been to investigate whether the CAH-concentration in tree cores could be used to delineate the spread of CAH in a soil environment under Swedish conditions in different seasons. The aim has also been to gain an understanding of the uptake process, as well as to identify the limitations of the method and important issues to consider when sampling.</p><p>Trees were sampled in March and June on Helgö 1:25, 1:26 in Växjö, Småland. Metal degreasing earlier conducted at this site has lead to the CAH contamination of soil and groundwater (PCE, TEC c-DACE). Mostly PCE, TCE, and chloroform were detected in tree cores. The CAH concentration was higher in June. Using the sum of PCE+TCE+c-DCE in trees to delineate the spread gave a result that was quite consistent with a delination done based on groundwater sampling.</p><p>The uptake of CAH by trees is governed by the uptake of water at the root. The water usage, together with the origin of the water used is important for the ability of the tree to take up CAH. The CAH concentration within trees is also dependent on the chemical properties of the compound (Log kow, solubility etc), the concentration of the compound in the soil as well as degradation processeses. The position and height of sampling in the trees, tree species as well as tree size are important factors to consider when sampling. Sampling during summer is preferred when the concentration of CAH in trees is likely to be higher.</p><p>The analysis of CAH in tree cores has potential to be used as a screening tool in soil investigations under Swedish conditions. It is a cheap and easy to use method, which would be a good complement to other investigative measures. However, an increased understanding of the processes involved, together with more analysis are needed., as this is a new method.</p> / <p>Klorerade lösningsmedel (CAH) användes i stor omfattning som bl a kemtvättmedel och avfettningsmedel tills dess att deras toxiska egenskaper blev kända. Perkloretylen (PCE) används än idag som kemtvättmedel. CAH återfinns ofta i markmiljö på de platser där de tidigare använts. Analys av CAH-koncentration i trädkärnor har uppmärksammats som en billig och effektiv metod för att översiktligt bedöma utbredningen av dessa föroreningar. Metoden har inte tidigare använts i Sverige.</p><p>Syftet med detta examensarbete är att undersöka om trädprovtagning kan användas för att bedöma utbredningen av föroreningar i markmiljö under svenska förhållanden vid olika årstider.</p><p>Analyserade CAH-halter i träd har jämförts med tidigare registrerade halter av CAH i grundvatten. Syftet har också varit att beskriva CAH-upptaget i träd, undersöka metodens begränsningar samt att sammanfatta viktiga aspekter vid provtagning.</p><p>Provtagningar av träd har genomförts under mars och juni på fastigheterna Helgö 1:25 och 1:26 i Växjö, där tidigare metallavfettning har medfört att mark och grundvattnet förorenats av CAH; perkloretylen (PCE), trikloretylen (TCE) och nedbrytningsprodukten dikloretylen (c1,2-DCE). Vid analys av trädkärnor detekterades främst PCE, TCE samt TCM (kloroform). Koncentrationen av CAH var högre i juni. Halten PCE+TCE+c-DCE i trädproverna gav en översiktlig bild av föroreningssituationen som överensstämde väl med de grundvattenprover som tidigare tagits på fastigheten.</p><p>CAH tas upp i vattenlöst fas vid trädens rötter. Trädets vattenbehov och vilket vatten det utnyttjar är därför viktigt för dess möjlighet att ta upp CAH. Ämnets kemiska egenskaper (log kow, flyktighet, mm.), samt förekomst och nedbrytning påverkar den halt som registreras i trädet. Vid provtagning bör provtagningspunkternas höjd över marken och position, trädart samt trädstorlek beaktas. Provtagning under sommaren är att föredra eftersom halterna då är högre.</p><p>Jämförelsen med grundvattenprovtagning visar att metoden har potential att användas i Sverige för att bedöma utbredningen av en CAH-förorening i markmiljö. Den är enkel att använda och kan vara ett alternativ på platser där konventionella metoder är svåra att genomföra. En ökad förståelse för involverade processer, samt utökade undersökningar av metoden är nödvändiga då metoden är ny.</p>

Les panneaux sandwichs sont des éléments de structure omniprésents au quotidien. Leur efficacité structurelle n'est plus à démontrer. Elle est même un élément déterminant dans le marché qui leur est associé. Ce mémoire de doctorat s'intéresse à un nouveau type d 'âme de panneau sandwich qui pourrait être amené à supplanter le nid d'abeilles dans certaines applications, le module à chevrons. L'objectif est donc de pouvoir faire une estimation précise du comportement de ces nouvelles âmes. Cependant le gain en efficacité structurelle des panneaux sandwichs se paye par une augmentation considérable de la complexité de leur comportement mécanique. C'est en particulier le cas de la raideur à l'effort tranchant qui est déterminante pour estimer l'efficacité d'une âme de panneau sandwich. Ainsi, ce travail nous a amené à reconsidérer en profondeur les méthodes pour calculer le comportement à l'effort tranchant des plaques en général. Il nous a conduit à proposer une nouvelle théorie des plaques ainsi qu'une méthode d'homogénéisation associée dans le cas périodique. Cette théorie peut être considérée comme l'extension de la théorie bien connue de Reissner-Mindlin au cas des plaques hétérogènes. Elle ne peut cependant pas être réduite au mod èle de Reissner-Mindlin dans le cas général. Dans le cas particulier des panneaux sandwichs incluant le module à chevrons, l'application de cette méthode d'homogénéisation permet de mettre en évidence un phénomène de distorsion des peaux qui affecte de façon notable la raideur à l'effort tranchant de ces panneaux / Sandwich panels are widespread in everyday life. Their structural efficiency is well-known and is a central criterion in possible applications. This Ph.D. thesis is dedicated to the study of a new sandwich panel core which might replace honeycomb in some applications: the chevron pattern. In order to compare this new core to other ones, an accurate knowledge of its mechanical behavior is necessary. However, the price for structural efficiency is a more complex mechanical behavior. This is the case for the shear forces stiffness which is critical when comparing sandwich panels cores. Thus, in this work we reconsider in details and in the general case how to derive plates behavior under shear forces. A new plate theory is suggested as well as the related homogenization scheme for periodic plates. This plate theory is the extension of the well-known Reissner-Mindlin plate theory in the case of heterogeneous plates. However, it cannot be reduced to a Reissner-Mindlin plate theory in the general case. In the special case of sandwich panels including the chevron pattern, applying the homogenization scheme brings out a skins distorsion phenomenon which affects a lot their shear forces stiffness

[pt] O advento do uso maciço de computadores em provas matemáticas, ocorrido ao final da década de setenta com a solução de um famoso problema matemático – a prova do Teorema das Quatro Cores – ocasionou disputas filosóficas que ainda hoje demandam esclarecimentos. O objetivo principal da tese consiste em elaborar alguns dos referidos esclarecimentos desde uma perspectiva motivada pela filosofia da matemática de Ludwig Wittgenstein, especialmente no que diz respeito à distinção continuamente manuseada e depurada pelo filósofo ao longo do desenvolvimento de seu pensamento entre provas e experimentos. Após apresentar as principais ideias da prova do Teorema das Quatro Cores em termos históricos, algumas distinções conceituais metodologicamente significativas são elaboradas. A seguir o trabalho analisa, a partir da concepção funcional de a priori de Arthur Pap, o argumento da introdução da experimentação nas matemáticas de Thomas Tymoczko. A leitura das controvérias filosóficas que se seguiram ao argumento de Tymoczko é então apresentada, aplicando-se as distinções conceituais anteriormente elaboradas. Por fim algumas ideias wittgensteinianas sobre da disitinção entre provas e experimentos são exploradas em conexão com a noção de sinopticidade de provas, considerando menos os papéis específicos de tais noções na filosofia da matemática de Wittgenstein, do que investigando as vantagens de suas possíveis aplicações no esclarecimento de tópicos críticos das referidas disputas. / [en] The massive use of computers in mathematical proofs, which started in the end of the seventies trough the solution of one famous mathematical problem – the Four-Color Theorem – entailed philosophical disputes still in need of elucidation. The central aim of this thesis consists in elaborating some of these elucidations from a point of view motivated by Ludwig Wittgenstein’s philosophy of mathematics, mainly in what concerns the distinction between proofs and experiments, which was continuously used and elaborated by the philosopher in the course of the development of his thought. After the presentation of the main ideas involved in the proof of the Four-Color Theorem from a historical perspective, some methodological conceptual distinctions are elaborated. The thesis then shifts to an analysis of the introduction of experiment in mathematics argument, by Thomas Tymoczko, from the point of view of Arthur Pap’s conception of functional a priori. An interpretation of the controversies that followed that argument is developed trough the application of the conceptual distinctions previously elaborated. At last, some wittgensteinian ideas about the distinction between proofs and experiments are explored in connection with the notion of surveyability of proofs, concerned less with its specific roles in Wittgenstein’s philosophy of mathematics than with investigating the advantages of its possible applications in the elucidation of some critical points in the referred controversies.

Les études astrochimiques de la formation stellaire sont particulièrement importantes pour la compréhension de l'évolution de l'Univers, du milieu interstellaire diffus à la formation des systèmes stellaires. Les récentes avancées en matière de modélisation chimique permettent d'apporter de nouveaux résultats sur le processus de formation stellaire et les structures mises en jeu. L'objectif de ma thèse était donc d'apporter un regard neuf sur la chimie de la formation stellaire en utilisant les récentes avancées sur le modèle chimique Nautilus. J'ai pour cela étudié l'évolution de la chimie du soufre durant la formation stellaire pour tenter d'apporter de nouvelles réponses au problème de déplétion du soufre. J'ai d'abord effectué une révision du réseau chimique soufré et étudié son effet sur la modélisation du soufre dans les nuages denses. En comparant aux observations, j'ai montré que le modèle textsc{Nautilus} était capable de reproduire les abondances des espèces soufrées dans les nuages denses en utilisant comme abondance élémentaire de soufre son abondance cosmique. Ce résultat m'a permis d'apporter de nouveaux indices sur les reservoirs de soufre dans ces objets. Puis j'ai effectué une étude complète de la chimie du souffre dans les coeurs chauds en me concentrant sur les effets sur la chimie de la composition pre-effondrement. J'ai également étudié les conséquences des différentes simplifications couramment faites pour la modélisation des coeurs chauds. Mes résultats montrent que la composition pre-effondrement est un paramètre majeur de l'évolution chimique des coeurs chauds, fournissant de nouveaux indices pour expliquer la variété de compositions en espèces soufrées observée dans ces objets. De plus, ma recherche a mis en évidence la nécessité d'uniformiser les modèles de chimie utilisés pour les coeurs chauds. Enfin, j'ai développé une méthode efficace pour inverser les paramètres initiaux d'effondrement de nuages denses en me basant sur une base de données de modèles physico-chimiques d'effondrement, ainsi que sur l'observation d'enveloppes de protoétoiles de Classe 0. A partir d'un échantillon de 12 sources, j'ai pu en déduire des probabilités concernant les possibles paramètres initiaux d'effondrement de la formation d'étoiles de faible masse. / Astrochemical studies of star formation are of particular interest because they provide a better understanding of how the chemical composition of the Universe has evolved, from the diffuse interstellar medium to the formation of stellar systems and the life they can shelter. Recent advances in chemical modeling, and particularly a better understanding of grains chemistry, now allow to bring new hints on the chemistry of the star formation process, as well as the structures it involves. In that context, the objective of my thesis was to give a new look at the chemistry of star formation using the recent enhancements of the Nautilus chemical model. To that aim, I focused on the sulphur chemistry throughout star formation, from its evolution in dark clouds to hot cores and corinos, attempting to tackle the sulphur depletion problem. I first carried out a review of the sulphur chemical network before studying its effects on the modeling of sulphur in dark clouds. By comparison with observations, I showed that the textsc{Nautilus} chemical model was the first able to reproduce the abundances of S-bearing species in dark clouds using as elemental abundance of sulphur its cosmic one. This result allowed me to bring new insights on the reservoirs of sulphur in dark clouds. I then conducted an extensive study of sulphur chemistry in hot cores and corinos, focusing on the effects of their pre-collapse compositions on the evolution of their chemistries. I also studied the consequences of the use of the common simplifications made on hot core models. My results show that the pre-collapse composition is a key parameter for the evolution of hot cores which could explain the variety of sulphur composition observed in such objects. Moreover, I highlighted the importance of standardizing the chemical modeling of hot cores in astrochemical studies. For my last study, I developed an efficient method for the derivation of the initial parameters of collapse of dark clouds via the use of a physico-chemical database of collapse models, and comparison with observations of Class 0 protostars. From this method, and based on a sample of 12 sources, I was able to derive probabilities on the possible initial parameters of collapse of low-mass star formation.

Data Plane Development Kit is a highly used library for creating network applications that can be run on all hardware. Data Plane Development Kit has a component called Service Cores, which allows the main applications to create services that will run independently. These services are manually mapped to specific CPU cores, and are scheduled in a round-robin method. Because of the manual mapping, and the scheduling, the different load for each service can impact the start time for each service. By having services not run when supposed to, the throughput will degrade. In this thesis, we investigate and try to solve the issue by implementing a basic load balancer into the Service Core component. Our results show that an basic load balancer, that will balance upon reaching a CPU upper threshold, will increase the throughput of services while decreasing the delay between each service run.

INTRODUÇÃO: O Traumatismo Cranioencefálico (TCE) é uma das maiores causas de mortalidade e incapacidade em adultos em todo o mundo. Uma complicação frequente e precoce do TCE é o desenvolvimento de hipertensão intracraniana, cujo diagnóstico e tratamento intensivo geralmente requer monitorização invasiva da pressão intracraniana (PIC); o interesse científico neste campo é crescente. Neste contexto, estudos recentes têm demonstrado que é possível detectar hipertensão intracraniana de forma não-invasiva através da aferição ultrassonográfica do diâmetro da bainha do nervo óptico (BNO), utilizando-se ultrassonografia do nervo óptico (USNO) com insonação pela janela transorbitária. Não se sabe ainda, entretanto, se essa aferição do diâmetro da BNO por USNO tem um real significado prognóstico quando aplicada em pacientes na fase aguda de um TCE. Neste estudo, objetiva-se avaliar o valor prognóstico da aferição do diâmetro da BNO por USNO, avaliada na admissão, em pacientes vítimas de TCE moderado e grave. MÉTODOS: Avaliaramse prospectivamente pacientes vítimas de TCE moderado ou grave (pontuação < 15 na escala de coma de Glasgow [GCS] ou com lesão intracraniana aguda na tomografia de crânio) admitidos na Unidade de Emergência do HCFMRP-USP, com idades entre 18 e 80 anos, de fevereiro/2015 a julho/2015. Após consentimento livre e esclarecido, estes pacientes foram submetidos a avaliação clínica com escalas padronizadas (NOS-TBI), e radiológica (incluindo tomografia de crânio e USNO) e seguidos até sua alta para avaliação cega do seu desfecho funcional (avaliada pela escala modificada de Rankin [mRS]). Após análise univariada, utilizou-se regressão linear e regressão logística multivariada, para identificação de preditores independentes do déficit neurológico (NOS-TBI) e da incapacidade funcional na alta (mRS). Aplicou-se, ainda, curva ROC e estatística C para avaliar a acurácia da USNO em relação incapacidade grave ou óbito intra-hospitalar. RESULTADOS: 70 pacientes foram analisados, sendo 63 (90%) homens, idade média 37,5 ± 15,1 anos, sendo 32 (45%) pacientes com TCE grave e 29 (41%) causados por acidentes de trânsito. Na análise multivariada por regressão linear, o diâmetro médio da BNO (B=4,8; IC 95%: 0,51 a 9,1; p=0,029) e a gravidade do comprometimento do nível de consciência (GCS) na admissão (B=-1,97; IC 95%: -2,9 a -1,0; p<0,001) foram os únicos preditores independentes da severidade do déficit neurológico na alta pela escala NOS-TBI. Na regressão logística multivariada, o diâmetro médio da BNO (OR:2,1; IC 95%:1,1 a 3,9; p=0,021) foi independentemente associado com um escore de mRS>=4 à alta, mesmo após ajuste para idade e GCS na admissão. CONCLUSÕES: Uma maior distensão da bainha do nervo óptico nas primeiras 24 após TCE moderado a grave está independentemente associada a pior déficit neurológico e capacidade funcional à alta. Esses resultados sugerem que a USNO deve ser mais explorada como método com potencial para orientar medidas terapêuticas intensivas de neuroproteção e controle de hipertensão intracraniana na fase aguda do TCE. / BACKGROUND: Traumatic brain injury (TBI) is a major cause of mortality and disability among adults worldwide. Intracranial hypertension is a frequent and early complication in such patients and its diagnosis and intensive management often require invasive monitoring of intracranial pressure (ICP). In this context, recent studies have shown that it is possible to non-invasively detect intracranial hypertension by ultrasound measurement of optic nerve sheath diameter (ONSD), using optic nerve ultrasound (ONUS) with trans-orbital window insonation. It is still unclear, however, whether the ONSD measurement through ONUS has real prognostic significance when applied to patients in the acute phase of a TBI. In this study, we aimed to evaluate the prognostic value of ONSD measurement by ONUS at admission in patients with moderate and severe TBI. METHODS: We prospectively evaluated patients with moderate or severe TBI (score <15 Glasgow Coma Scale [GCS] or acute intracranial lesion on CT scan) admitted to the Emergency Unit of HCFMRP- USP, aged 18 to 80 years, from February / 2015 to July / 2015. After informed consent, these patients underwent clinical evaluation with standardized scales (NOS-TBI), and radiological (including CT scan and ONUS), and blinded functional outcome assessment at discharge (assed by modified Rankin Scale - mRS). After univariate analysis, we used linear regression and multivariate logistic regression to identify independent predictors of neurological deficit at discharge (NOS-TBI and mRS). We also used ROC Curves and C statistics to evaluate the accuracy of different ONSD cut-offs to identify severe disability and death at discharge. RESULTS: We analyzed 70 patients, 63 (90%) men, mean age 37.5 ± 15.1 years, 32 (45%) with severe TBI, 29 (41%) caused by traffic accidents. After multivariate linear regression analysis, the average diameter of the ONSD (B=4.8; IC 95%: 0.51 a 9.1; p=0.029) and the severity of consciousness impairment (GCS) at admission (B=-1,97; IC 95%: -2,9 a -1,0; p<0,001) were the only independent predictors of neurological deficit severity by the NOS-TBI scale at discharge. On multivariate logistic regression analysis, after age and GCS adjust, the mean ONSD was independently associated with a mRS>=4 at discharge. CONCLUSIONS: Increased distension of the optic nerve sheath in the first 24 after a moderate to severe TBI is independently associated with a worse neurological and functional outcome at discharge. Our results indicate that additional studies should be performed to test ONUS as a method with potential to guide intensive therapeutic measures of neuroprotection and intracranial hypertension control in the acute phase after TBI.

O presente estudo investigou a função visual de pacientes com diabetes tipo 1 atletas e sedentários através de testes psicofísicos e eletrofisiológicos computadorizados de última geração. O objetivo foi investigar possíveis efeitos do exercício físico nas funções visuais. Materiais e Métodos: 33 pacientes com diabetes tipo 1, divididos em dois grupos experimentais: diabético atleta (n = 15; idade = 33,33 ± 6,78; tempo de doença =16,19 ± 6,63) e diabéticos sedentário (n = 18 idade = 28,94 ± 6,04; tempo de doença = 15,92 ± 8,46) e 40 sujeitos controles: controle atleta (n = 20; idade = 32,0 ± 5,61) e controle sedentário ( n = 20; idade = 27,05 5,60 ) foram submetidos a exames de: visão de cores e sensibilidade ao contraste Cambridge Colour Test - CCT; eletroretinograma por padrão reverso PERG e análises laboratoriais para quantificar óxido nítrico e endotelina por quimioluminescência e ELISA. As comparações entre os grupos foram feitas através de teste não paramétrico (Teste Kruskal-Wallis). Resultados: O grupo Diabético apresentou perdas significativas na amplitude do PERG, na discriminação de cores no eixo protan, área da elipse e nas frequências espaciais avaliadas da função da sensibilidade ao contraste, além de disfunção dos fatores endoteliais comparado ao grupo Controle. O grupo diabético atleta apresentou concentração maior de óxido nítrico comparado ao grupo Diabético sedentário. Não foram encontradas correlações entre os fatores endoteliais e as funções visuais. Conclusão: foram encontradas perdas funcionais na avaliação psicofísica e eletrofisiológica de pacientes com diabetes tipo 1. Os achados deste estudo confirmam a hipótese de que as perdas visuais sejam de origem neural pós - receptoral. Aumento na concentração de óxido nítrico encontrado em pacientes diabéticos atletas, confirmam os achados da literatura de que o exercício físico é capaz de aumentar a biodisponibilidade deste fator endotelial. Entretanto esse aumento de biodisponibilidade não se refletiu em recuperação das perdas nas funções visuais, uma vez que não houve correlação entre as alterações dos fatores endoteliais e os resultados da avaliação visual. A conclusão, em resumo, é de que o exercício físico não promoveu proteção dos danos visuais verificados em pacientes diabéticos / The study compared visual functions of sedentary and athlete patients with type 1 diabetes, and respective controls, using computerized psychophysical and electrophysiological tests. Materials and Methods: 33 Patients with type 1 diabetes, divided into two experimental groups: athlete diabetics (n = 15; age = 33.33 ± 6.78; rate of disease = 16.19 ± 6.63) and sedentary diabetics ( n = 18 age = 28.94 ± 6.04; rate of disease = 15.92 ± 8.46) and 40 control subjects: athlete control (n = 20; age = 32.0 ± 5.61) and sedentary control (n = 20; age = 27.05 5.60) were subjected to tests of: color vision and contrast sensitivity - Cambridge Colour Test - CCT; pattern electroretinogram (PERG) and laboratorial analysis of nitric oxide and endothelin using chemiluminescence and ELISA. The comparisons between groups were made through the nonparametric (Kruskal-Wallis test). Results: compared the control group, the diabetic group showed significant losses (1) in color discrimination in the protan axis and in ellipse area (2) in several spatial frequencies of the luminance spatial contrast sensitivity function; (3) a reduction in PERG amplitude and (4) dysfunction of endothelial factors. The athlete diabetic group showed increased concentration of nitric oxide compared to the sedentary diabetic group. No correlations were found between the endothelial factors and visual functions. Conclusion: losses in psychophysical and electrophysiological functions were found in patients with type 1 diabetes. The findings support the hypothesis that visual losses are due to the post-receptoral pathways. Increased nitric oxide concentration found in athlete diabetic patients, confirm the findings of the literature that physical exercise can increase the bioavailability this endothelial factor. However this increase in bioavailability was not reflected in the recovery of losses in visual functions, since there was no correlation between changes in endothelial factors and results of visual assessment. In conclusion, the exercise did not promote protection against visual losses due to diabetes