Unsupervised Odometry and Depth Learning for Endoscopic Capsule Robots

In the last decade, many medical companies and research groups have tried to convert passive capsule endoscopes as an emerging and minimally invasive diagnostic technology into actively steerable endoscopic capsule robots which will provide more intuitive disease detection, targeted drug delivery and biopsy-like operations in the gastrointestinal(GI) tract. In this study, we introduce a fully unsupervised, real-time odometry and depth learner for monocular endoscopic capsule robots. We establish the supervision by warping view sequences and assigning the re-projection minimization to the loss function, which we adopt in multi-view pose estimation and single-view depth estimation network. Detailed quantitative and qualitative analyses of the proposed framework performed on non-rigidly deformable ex-vivo porcine stomach datasets proves the effectiveness of the method in terms of motion estimation and depth recovery.Comment: submitted to IROS 201

Age, Growth and Mortality of Unio tigridis (Bourguignat, 1852)

Unio tigridis has an importance for the biodiversity of freshwater ecosystem of the Turkey. However, there is no available literature in the world on the growth of this species yet. The aim of this study, therefore, was to describe the age, growth and mortality of this species living in Lake Gölbaşı from Hatay providence, Turkey. A total 428 of specimen were collected using by divers with hand dredges in depth of 1 to 6 meters based on annual sampling strategy from June- 2004 to May- 2005. Lengths and weighs of sample were ranged as 2.1 to 9.2 cm (6.79 ± 1.52) and 1.1 to 73.05 g (34.18 ± 15.56), respectively. Weight-Length relationship of all specimens was described as W=0.193L2.63 (R2=0.94). Thus, a negative allometric growth was detected in the sampled population. The age of each individual was determined by counting the external shall annuli-growth interruption lines. The sampled population was composed of 18 age classes. Specimen belong to age class 7 was the most presented with 20.33 percent in the population. The rate of male to female (m:f) was 0.91:1. Seasonalized von Bertalanffy growth model (SVBGM) was used to describe the growth. From these results, it was shown that seasonality in growth does not occur in this lake for this species (L∞ = 8.80 cm (Shell Length), K = 0.271 year-1, t0 = -0.161 year, C = 0.014, ts = 0.100 year with RSS = 23.22). The total mortality rate (Z ± Se) was calculated as 0.401 ± 0.015 year-1 with R-square = 0.99 (CL of Z with 95 % = 0.361 - 0.440 year-1). Although, there is no fishing, no pollution and no predation risk on this species yet, due to growth characteristic, high K and low L∞, this type of species are vulnerable to extinction

A new wide area-based algorithm to determine faulted line in series-compensated grid using k-nearest neighbor (k-NN) classification method

Nowadays, series capacitors are frequently used to increase the transfer capacity and reduce losses on long transmission lines. They also play an important role in improving the voltage stability of the grid. In addition to the positive contributions, it is known that series capacitors affect the operation of distance relays negatively in series-compensated lines and adjacent lines. In this study, a protection algorithm based on wide-area monitoring is proposed using the K-NN classification method to protect series compensated transmission lines in steady-state. The algorithm is tested offline in the radial grid created in the Digsilent Power Factory program. In short circuit scenarios, 2-phase, 3-phase, 2-phase to ground and single-phase to ground faults are analyzed under different fault impedances. According to the results, in case of short circuit faults at certain locations of the lines, the proposed algorithm has determined the faulted line accurately. After the faulted line has been determined, a protection scheme is also proposed for the network

The Relationship Between Digit Ratio (2D: 4D) and Cardiovascular Capacity in Young Adults

DergiPark: 379062tmsjAims: The ratio of the second-to-fourth finger length was first proposed as a prenatal testosterone biomarker. Studying this matter with a different point of view, the aim of this study is to find whether there is a positive relationship between digit ratio and cardiovascular capacity.Methods: The data of 82 students who were between the ages of 18 and 25 old from Trakya University Faculty of Medicine were analyzed by evaluating the results of the six-minute walking test and the results of their digit measurements. Independent Samples T-Test was used to determine the correlation between the prevalence of longer 4th digit and six-minute walking test results.Results: The data obtained from the test results of the students, that were grouped regarding digit ratio, were statistically evaluated. With the results of the six-minute walking test, students that have lower digit ratio walked 593.87 ± 73.2 meters while students with higher digit ratio walked 584.17 ± 71 meters showing us that there is not a significant relationship between cardiovascular capacity and digit ratio.Conclusion: With the gathered information and results, it is seen that there is not a positive relationship between digit ratio and cardiovascular capacity. In conclusion it can be said that digit ratio does not have a beneficial effect on a persons cardiovascular capacity. Usage of digit ratio as a prenatal hormone exposure has been increasing, and extensive studies in physiological and psychological conditions in humans have been correlated with digit ratio, including athletic ability, fertility, social behaviors, sex-biased diseases, and sexual orientatio

Preparation of nano-fiber structured sepiolite determining fiber size with atomic force microscopy (AFM)

Sepiyolit, mikrofiber yapılı ve yüksek yüzey alanına sahip doğal bir kil mineralidir. Yüksek yüzey alanı, lifsi yapısı, porozitesi, kristal morfolojisi ve kompozisyonu, yüzey aktivitesi, düşük konsantrasyonlarda yüksek viskoziteli duraylı süspansiyonlar oluşturma gibi sıra dışı özellikleri mevcuttur. Sepiyolitin yapısı, ısıl işlemlere, asitle muameleye ve ayrıca uygulanabilecek mekaniksel işlemlere karşı hassasiyeti sayesinde mineralin sahip olduğu sorptif, katalitik ve reolojik özellik gibi en faydalı özelliklerini değiştirmek mümkün olabilir. Sepiyoliti oluşturan lif demetleri suda bir mekanik karıştırıcı kullanılarak dağıtılırsa, bir ağ yapı içerisinde parçacık iç ve dış yüzeyleri artan lifler daha fazla su adsorplama ve parçacıklar arasında daha fazla su tutulmasını sağlayarak viskozitenin artırılmasına yardımcı olmaktadır. Bu çalışmada yapılan viskozite ölçümlerine göre; 21000 rpm hızda yüksek hızlı bir mekanik karıştırıcıda 3 dakika boyunca işleme tabi tutularak hazırlanan pülp ile 5 rpm spindle hızında ölçülen en yüksek görünür viskozite olarak 9600 cP elde edilmiştir. Karıştırma hızının düşmesi ile viskozite değerleri düşmektedir. Artan süreler ise kritik bir eşiğe kadar viskozite değerini artırdıktan sonra düşürmektedir. Nano boyutlara kadar serbestleşmesi beklenen sepiyolitin, birim liflere ayrılmasını teyit etmek ve bu ölçekte boyutlarının belirlenebilmesi nano ölçekli malzeme hazırlanabilmesi için önemli bir aşamadır. Bu nedenle daha önce smektit tipi killerle gerçekleştirilen Atomik Kuvvet Mikroskobu (AFM) çalışmalarına paralel olarak inceleme gerçekleştirilmiştir. Sepiyolit için AFM inceleme numunesi hazırlama yöntemi belirlenmiş ve ortalama olarak en iyi viskoziteyi veren pülpteki lif boyutları 249*29*1127 nm (genişlik*yükseklik*uzunluk) olarak tespit edilmiştir. Alınan görüntülerde 3 dakika mekanik dağıtma öncesinde liflerin demetler halinde olduğu, sonrasında sepiyolit liflerinin kırılarak parçalanmakta olduğu görülmüştür. Bu kırık lifler, boyutlarının küçüklüğü nedeniyle rastgele bir ağ yapı içerisinde kendilerine yer bulamayarak viskoziteyi düşürmeye neden olmaktadır.  Anahtar Kelimeler: Sepiyolit, mekanik dağıtma, AFM ile boyut tayini.Sepiolite is a natural hydrated magnesium silicate clay mineral with microfiber structure and high surface area. Fibers are constructed by tetrahedral and octahedral structured oxides within half cell formula of Si12O30Mg8(OH,F)48H2O. Sepiolite has special futures like; high surface area, fiber structure, porosity, tunnel/channel composition, crystal morphology, surface activity and formation of stable high viscosity suspensions at low solid concentrations. This unique structure of sepiolite can be altered by heat and/or acid activations. It also exhibits severe sensitivity to any mechanical perturbations; any interference may result as structural changes which can enhance or deteriorate the characteristics of sepiolite. Cation exchange capacity, fiber dimensions (fiber length/fiber width) and the type and amount of accompanying impurities are the main factors identifying the reologic behavior of sepiolite pulps. If sepiolite fiber bundles are disintegrated in water with a mechanic impeller, these particles may form random structures in the form of networks and increase the apparent viscosity values. Better dispersion of these fibers leads to an enhancement of water sorption on the fiber surface and in turn in inner galleries, resulting in entrainment of water within the network and thus viscosity increase. In this study, the dimensions of sepiolite fibers after mechanical dispersion are investigated based on a technique described in the literature for monitoring the sizes of montmorillonite and smectite type clays by Atomic Force Microscope (AFM). Unlikely the previous studies where a sepiolite fiber sizes were measured with SEM technique; conducting AFM study to determine the difference in the sizes of sepiolite fibers is unique. The mechanical dispersion process is conducted as a function of time and stirring rate, and the results of rheological behavior is followed through viscosity. A Turkish sepiolite sample of 65 10% purity was obtained from Eskişehir region. Sepiolite suspensions were prepared at 3%solids by weight in pure water as described in the literature. As sepiolite suspensions are characterized by time dependent flow behavior, they exhibit thixotrophy. The viscosity measurements were taken at different spindle rates but particularly at 5 rpm spindle rate. The highest viscosity value was obtained with the suspensions prepared at the highest stirring rate of 21.000 rpm. The samples run at 1, 3, 5 min. and the corresponding viscosity values of 6400, 9600, 4800 cP respectively were collected for AFM investigations. Several techniques have been established to investigate platelet structured clays. For our special case, these procedures were overrun and modified to investigate the fiber structured sepiolite samples; this involves dropping of 1 ml dilute sepiolite suspension onto a clean mica surface. The drop is dried with nitrogen gas and the mica plate is stored in a Petri dish till AFM investigation to avoid any airborne impurities to settle on the surface. For AFM investigations, Nanoscope III model AFM set up was used at the tapping mode to produce 512*512 pixel graphics of sepiolite settled on the mica surface. The sample prepared for 1 minute stirring, represents bundles consisting of approximately 50-60 fibers. Ensuing sample of 3 minutes stirring was made with fiber groups of 5-10. Increase in apparent viscosity values upon increasing stirring time, indicates the presence of loosened bundles and thus better network. However, when the stirring period is increased to 5 minutes the viscosity value decreases and the AFM graphics, showed the failure in size uniformity with accompanying a weak networking. AFM graphics n-Surf 1.0 Beta visualizer program coupled with XYit program is used for numerical analysis of the fiber or bundle dimensions. Finally the collected data are averaged with Excel program. Investigating a total of 130 profiles, the average height*width of 1, 3 and 5 minute stirring is found as 514*50, 249*28 and 157*22 nm, respectively; the corresponding fiber or bundle lengths are 1643, 1126 and 1055 nm, respectively. As a result considering the average sizes, at the same percent solids, the number of fibers or groups in a suspension prepared at 3 minute stirring is 8 times more than that of 1 minute stirring, indicating a better network leading to higher viscosity. As opposed to this,  further stirring at 5 minute stirring deteriorated the dimensions of fibers and the formation of network due to fracture of fibers. Keywords: Sepiolite, mechanic dispersion, size determination with AFM

Incidence and predictors of radial artery injury following transradial procedures: Yet another benefit of renin–angiotensin system blockade?

Background: Vasodilatory function of radial artery (RA) declines following the transradial catheterization. However, it is uncertain whether impaired vasodilatory function develops in every patient. The aim of this study was to investigate the incidence and predictive factors of impaired vasodilatory function following transradial procedures. Methods: Consecutive patients undergoing elective transradial procedures were prospectively enrolled. Ultrasound examination of RA was recorded just before and 1 week after the procedure. RA diameters and flow velocities were measured at baseline, after flow mediated vasodilation (FMD) and after nitrate mediated vasodilation (NMD). Results: Fifty-one patients were included (62 ± 11 years, 55% male, 41% hypertensive, 20% diabetic, 65% with coronary artery disease). Overall FMD and NMD were significantly impaired after 1 week. However, deterioration of FMD and NMD was observed in 67% and 71% of patients, respectively. Absolute change in FMD was significantly different in patients using a renin– angiotensin system (RAS) inhibitor compared to those who were not (1.9 ± 12.9 vs. –7.7 ± ± 12.7%, respectively, p = 0.025). Additionally, there was a moderate but significant correlation between baseline RA diameter and absolute change in NMD (r = 0.419, p < 0.001). RAS blockade was independently associated with protection against FMD deterioration (OR 0.241, 95% CI 0.066–0.883, p = 0.032), whereas RA diameter (OR 0.079, 95% CI 0.009–0.720, p = 0.024) and procedure time (OR 1.156, 95% CI 0.989–1.350, p = 0.068) were associated with NMD deterioration, although the latter had borderline significance. Conclusions: Vasodilatory function of RA gets impaired in most patients following transradial procedures. RAS blockade seems to exert a protective role against deteriorating endothelium- dependent vasodilation, whereas smaller RA diameter and potentially longer procedure time are associated with impaired endothelium-independent vasodilation.

Para uma Sócio-História da Língua Guarani no Espírito Santo: uma análise sob a perspectiva sociolinguística.

Estima-se que restam hoje cerca de 50 mil índios Guarani no Brasil, que se situam, principalmente, na faixa litorânea que vai desde os estados do sul até o território capixaba, o Espírito Santo. Considerando que essa comunidade se mantém bilíngue, conservando praticamente intacta sua língua, e no intuito de analisar sua linguagem, o presente trabalho objetiva discutir se, na situação de contato entre o Guarani e o Português, a primeira língua está ou não cedendo lugar à segunda. Para alcançar esse objetivo, foi formado um banco de dados de fala por meio de entrevistas realizadas nas aldeias, que versaram sobre as tradições históricas, a família, a religião, a economia e o meio ambiente aspectos considerados por eles como as principais armas de resistência desse povo. A análise tomou por base os pressupostos da Sociolinguística/Contato Linguístico, com teóricos como Weinreich (1953), Fishman (1968; 1972), Appel e Muysken (1996), Coulmas (2005) e outros, que discutem temas pertinentes à pesquisa em questão: o contato linguístico e a manutenção/substituição de línguas minoritárias. Verificou-se, conforme o andamento da pesquisa, que, apesar do contato com o português pela venda de artesanatos, pela mídia e pela atuação da escola e sua ação integralizadora, prevista pelo Estatuto do Índio, o Guarani mantém a sua língua materna - ainda que estigmatizada - devido à forte religiosidade que norteia todo o seu modo de vida. Ele entende a palavra como um dom e confere a ela um poder mítico de conexão com o mundo espiritual, o que, ao mesmo tempo, confere extrema importância à língua minoritária e favorece a sua preservação, enquanto marca importante da cultura e identidade desse povo