Hiding Data and Detecting Hidden Data in Raw Video Components Using SIFT Points

Steganography is a science of hiding data in a medium whereas steganalysis is composed of attacks to find the hidden data in a cover medium. Since hiding data in a text file would disturb the coherence of the text or make it suspicious, systematically changing pixels of a visual is a more common method. This process is performed on pixels that are spatially (and/or temporally, for video components) distant from each other so that a viewer\u27s eye can be deceived. Online media are subject to modification such as compression, resolution change, visual modifications, and such which makes Scale Invariant Feature Transform (SIFT) points appropriate candidates for steganography. The current paper has two aims: the first is to propose a method that uses the SIFT points of a video for steganography. The second aim is to use Convolutional Neural Networks (CNN) as a steganalysis tool to detect the suspicious pixels of a video. The results indicate that the proposed steganography method is effective because it yields higher peak signal-to-noise ratio (PSNR = 95.41 dB) compared to other techniques described in cybersecurity literature, and CNN cannot detect hidden data with much success due to its 52% accuracy rate

Repeatability, Reproducibility and Agreement of Central Corneal Thickness Measurements by Two Noncontact Pachymetry Devices

This study was designed to assess the repeatability, reproducibility, and agreement of Noncontact Pachymetry (NPC) (Topcan TRK-2P) and the non-contact optical low coherence reflectometer (Lenstar LS 900) devices for measuring Central Corneal Thickness (CCT) of healthy corneas. A total of 82 healthy volunteers were evaluated. The first observer used both the TopconTRK-2P and Lenstar 900 devices while the second observer only used the TopconTRK-2P for the measurements. The measurements with either device were repeated three times for each patient, consecutively. The central corneal thickness measurements with the Topcon TRK-2P revealed mean ± Standard Deviation (SD) values of 553.1 ± 36.1 micrometer (µm) for the first observer and 552.3 ± 35.9µm for the second observer and the mean ± SD of CCT was 537.3 ± 34.8µm with the Lenstar 900. The difference between the CCT measurements of the observers using the Topcon TRK-2P (P = 0.142) was insignificant. However, significantly lower measurements were found with the Lenstar 900 compared with the Topcon TRK-2P (P ˂ 0.001). The central corneal thickness measurements obtained by the Topcon TRK-2P were found to have high repeatability for both observers with a lower SD, less than 1% Coefficient of Variation (CV) and higher than 0.99 Intra-Class Correlation Coefficient (ICC) (Observer 1: 3.77 SD, 0.68 CV and 0.995 ICC; the second observer: 3.58 SD, 0.65 CV and 0.995 ICC). There was an excellent inter-observer reproducibility between the two observers for Topcon TRK-2P with 2.71 SD, 0.49 CV, and 0.994 ICC. The Bland-Altman plot showed high agreement between the two devices. These results suggest that the TopconTRK-2P is a reliable device for evaluating CCT in healthy corneas compared with Lenstar 900

Exercise training and detraining process affects plasma adiponectin level in healthy and spontaneously hypertensive rats

BACKGROUND: Adiponectin levels with long-term swimming exercise have been never investigated in spontaneously hypertensive rats (SHR). OBJECTIVE: This study was aimed to investigate the effects of exercise and detraining process on the adiponectin plasma levels of spontaneously hypertensive rats (SHR) and healthy Wistar-Kyoto rats (WKY). MATERIAL AND METHODS: The rats in the exercise groups were swimming for 10 weeks, 5 days/week, one hour in a day. The detraining rats were left to be sedentary in their cages for 5 weeks after 10 weeks of exercise period. RESULTS: The plasma adiponectin levels decreased in E and SHRE groups compared to the SC and the SHR groups, respectively. In addition, blood pressure was decreased in the exercise groups vs their controls. The adiponectin level was not found to be significantly different in ED and SHRED groups compared to their controls. The blood pressure did not differ between SDC and ED groups, although in the SHRED group it was found to be lower than in SHRSD group rats. CONCLUSION: The results of this study showed that exercise reduced plasma levels of adiponectin in healthy and spontaneously hypertensive rats. However, this difference disappeared at the end of the training processes. Our results suggest, that changes in plasma adiponectin levels are not responsible for changes in blood pressure

Repeatability, Reproducibility and Agreement of Central Corneal Thickness Measurements by Two Noncontact Pachymetry Devices

This study was designed to assess the repeatability, reproducibility, and agreement of Noncontact Pachymetry (NPC) (Topcan TRK-2P) and the non-contact optical low coherence reflectometer (Lenstar LS 900) devices for measuring Central Corneal Thickness (CCT) of healthy corneas. A total of 82 healthy volunteers were evaluated. The first observer used both the TopconTRK-2P and Lenstar 900 devices while the second observer only used the TopconTRK-2P for the measurements. The measurements with either device were repeated three times for each patient, consecutively. The central corneal thickness measurements with the Topcon TRK-2P revealed mean ± Standard Deviation (SD) values of 553.1 ± 36.1 micrometer (µm) for the first observer and 552.3 ± 35.9µm for the second observer and the mean ± SD of CCT was 537.3 ± 34.8µm with the Lenstar 900. The difference between the CCT measurements of the observers using the Topcon TRK-2P (P = 0.142) was insignificant. However, significantly lower measurements were found with the Lenstar 900 compared with the Topcon TRK-2P (P ˂ 0.001). The central corneal thickness measurements obtained by the Topcon TRK-2P were found to have high repeatability for both observers with a lower SD, less than 1% Coefficient of Variation (CV) and higher than 0.99 Intra-Class Correlation Coefficient (ICC) (Observer 1: 3.77 SD, 0.68 CV and 0.995 ICC; the second observer: 3.58 SD, 0.65 CV and 0.995 ICC). There was an excellent inter-observer reproducibility between the two observers for Topcon TRK-2P with 2.71 SD, 0.49 CV, and 0.994 ICC. The Bland-Altman plot showed high agreement between the two devices. These results suggest that the TopconTRK-2P is a reliable device for evaluating CCT in healthy corneas compared with Lenstar 900

Open reduction and percutaneous pinning for medial condyle fractures of elbow in children: is it a risk for complications?

Background: There are limited cases of humerus medial condyle fracture in the literature treated by open reduction and percutaneous pinning. This study presents cases treated by open reduction and percutaneous pinning and discussed the problems reported in the literature.Methods: Nine cases were treated by open reduction and percutaneous pinning between 2006-2014. These cases were followed for nonunion, avascular necrosis, range of motion, nerve lesion and infection for 15.3 months (range 11 to 18 months).Results: No non-union, avascular necrosis, iatrogenic nerve lesion or infection developed in our cases. All patients gained full range of motion.Conclusions: This study presents that surgical technique and early timing of surgery prevents the complications

A biomechanical comparison of two cephalomedullary nails; one using a single lag screw with antirotator blade and a nail using two lag screws for unstable intertrochanteric fractures

Background: Implant choice for fixation of intertrochanteric fractures remains controversial despite being one of the most commonly performed operations. Although use of sliding hip screws is still considered a gold standard in treatment of these fractures, there is a wide tendency in using cephalomedullary nails because of their biomechanical superiority over sliding hip screws. This trial was initiated in order to compare the biomechanical properties of two different cephalomedullary nails, aPFN and the PROFIN under axial loading, based on the questions that can a single lag screw with an antirotator blade render better rotational stability? Is there a difference between one lag screw or two lag screws with respect to superior migration or cut-out of the screws? And do different nail designs cause different types of failure and what are the pros and cons of classical and new designs from the view point of biomechanical aspects?Methods: Ten pairs of third generation synthetic bone models simulating unstable intertrochanteric fracture were used for biomechanical testing.Results: No posterior displacement of screws was recorded in both groups suggesting rotational unstability.  There was not a significant difference between forces values loaded at the time of failure.Conclusions: Although there was no statistically significant difference between compressive strengths at the time of failure, aPFN may provide equal rigid fixation with less possible cut-out which may have an important consequences in real clinical applications