Reservoir sedimentation in the Demirköprü Dam, Turkey

River morphodynamics and sediment transportSedimentation in reservoir

Selecting stimuli parameters for video quality studies based on perceptual similarity distances

This work presents a methodology to optimize the selection of multiple parameter levels of an image acquisition, degradation, or post-processing process applied to stimuli intended to be used in a subjective image or video quality assessment (QA) study. It is known that processing parameters (e.g. compression bit-rate) or technical quality measures (e.g. peak signal-to-noise ratio, PSNR) are often non-linearly related to human quality judgment, and the model of either relationship may not be known in advance. Using these approaches to select parameter levels may lead to an inaccurate estimate of the relationship between the parameter and subjective quality judgments – the system’s quality model. To overcome this, we propose a method for modeling the relationship between parameter levels and perceived quality distances using a paired comparison parameter selection procedure in which subjects judge the perceived similarity in quality. Our goal is to enable the selection of evenly sampled parameter levels within the considered quality range for use in a subjective QA study. This approach is tested on two applications: (1) selection of compression levels for laparoscopic surgery video QA study, and (2) selection of dose levels for an interventional X-ray QA study. Subjective scores, obtained from the follow-up single stimulus QA experiments conducted with expert subjects who evaluated the selected bit-rates and dose levels, were roughly equidistant in the perceptual quality space - as intended. These results suggest that a similarity judgment task can help select parameter values corresponding to desired subjective quality levels

Possible interactions between neomycin and calcium channels in abdominal skeletal muscle

The present study was performed to investigate whether neomycin, an aminoglycoside, interacts with calcium channels in the frog rectus abdominis muscle. We thus examined the effects of methoxyverapamil (D600), a dihydropyridine-sensitive calcium channel antagonist, and neomycin on contractions induced by acetylcholine (ACh; 10-6, 3 × 10 -6, 5 × 10-6, 10-5 and 5 × 10 -5 M), electrical field stimulation (EFS; 5, 8, 10 Hz, 15 V, 1 ms) and potassium chloride (KCl; 40 mM) in isolated frog rectus abdominis muscle. D600 (10-6 - 3 × 10-4 M) exhibited a concentration dependent inhibitory action on contractions evoked by ACh, EFS and KCl. Neomycin (10-5-5 × 10-4 M) significantly inhibited the contractions elicited by ACh and EFS in a concentration dependent manner but it failed to reduce the KCl-evoked contractions. These results suggest that the inhibitory action of D600 on ACh-, EFS- and KCl-induced contractions reflect the action of this agent on Ca2+-channel activity in the isolated frog rectus abdominis muscle. A similar mechanism may also be involved in the action of neomycin on the frog abdominal skeletal muscle

Evaluating the teratogenicity of ritodrine and nifedipine using a frog embryo teratogenesis assay (FETAX)

PubMedID: 25156158The Frog Embryo Teratogenesis Assay - Xenopus (FETAX) was used to assess the teratogenic potential of two tocolytics. Embryos of the South African clawed frog, Xenopus laevis, were exposed to ritodrine or nifedipine. Exposure media were changed and monitored at 24-hour intervals. The 96-hour LC50 (Lethal concentration), the 96-hour EC50 (Malformation), and the No Observable Adverse Effect Concentrations (NOAEC) and the Lowest Observable Adverse Effect Concentration (LOAEC) for mortality, malformation and length were determined for each drug. Nifedipine was determined to be the more toxic and teratogenic than ritodrine, with a LC50 of 0.606 µg/L, an EC50 of 0.006 µg/L, and a teratogenicity Index (TI) value (LC50/EC50) of 101. On the other hand, the LC50 of ritodrine was 28.571 mg/L. In addition; the LC50, EC50 and TI values for nifedipine in the 5 mg/L ritodrine + nifedipine combination group were determined as 1.050 µg/L, 0.868 µg/L and 1.5 respectively. For ritodrine, the NOAEC and LOAEC values were determined as 2 mg/L and 4 mg/L, respectively. For the nifedipine and the ritodrine + nifedipine groups; while the LOAEC values of these groups were 0.0001 µg/L and 0.1 µg/L, respectively. NOAEC value couldnt be determined. Our results demonstrated that nifedipine administration was associated with higher levels of teratogenic and toxic effects. However, the ritodrine + nifedipine combination form reduced the toxic and teratogenic effects of nifedipine on Xenopus embryos. Further studies should be conducted in order to investigate the optimal combination concentrations of these substances for the treatment of preterm labor. © 2014 Informa Healthcare USA, Inc.British Association for PsychopharmacologyThis work was supported by the scientific Research Office of the C¸ ukurova University (I.U BAP). (Project No: TF2011BAP39)

New designs for improving the efficiency and resilience of natural language watermarking

Contributing our own creativity (in the form of text, image, audio, and video) to the pool of online information is fast becoming an essential part of online experience. However, it is still an open question as to how we, as authors, can control the way that the information we create is distributed or re-used. Rights management problems are serious for text since it is particularly easy for other people to download and manipulate copyrighted text from the Internet and later re-use it free from control. There is a need for a rights protection system that travels with the content . Digital watermarking is a mechanism that embeds the copyright information in the document. Besides traveling with the content of the documents, digital watermarks can also be imperceptible to the user, which makes the process of removing them from the document challenging. The goal of this thesis is to design practical and resilient natural language watermarking systems. I have designed and implemented several natural language watermarking algorithms that use the linguistic features of the cover text in order to embed information. Using linguistic features provides resilience through making the message an elemental part of the content of the text, and through the judicious use of ambiguity in the usage of natural language and richness of features of natural language constituents. In this thesis, I propose several practical and resilient natural language watermarking systems for a variety of genres of text (short, long, edited and cursory text) and analyze their resilience and feasibility. Significant by-products of this research are as follows: a protocol for improving the stealthiness of information hiding systems; systems for using the proposed information hiding mechanisms to solve the problems of private communication and phishing defense; analysis of the evaluation methodologies and detection techniques for information hiding systems that use natural language text as cover