Analysis of Slotted ALOHA with an Age Threshold

We present a comprehensive steady-state analysis of threshold-ALOHA, a distributed age-aware modification of slotted ALOHA proposed in recent literature. In threshold-ALOHA, each terminal suspends its transmissions until the Age of Information (AoI) of the status update flow it is sending reaches a certain threshold $\Gamma$. Once the age exceeds $\Gamma$, the terminal attempts transmission with constant probability $\tau$ in each slot, as in standard slotted ALOHA. We analyze the time-average expected AoI attained by this policy, and explore its scaling with network size, $n$. We derive the probability distribution of the number of active users at steady state, and show that as network size increases the policy converges to one that runs slotted ALOHA with fewer sources: on average about one fifth of the users is active at any time. We obtain an expression for steady-state expected AoI and use this to optimize the parameters $\Gamma$ and $\tau$, resolving the conjectures in \cite{doga} by confirming that the optimal age threshold and transmission probability are $2.2n$ and $4.69/n$, respectively. We find that the optimal AoI scales with the network size as $1.4169n$, which is almost half the minimum AoI achievable with slotted ALOHA, while the loss from the maximum throughput of $e^{-1}$ remains below $1\%$. We compare the performance of this rudimentary algorithm to that of the SAT policy that dynamically adapts its transmission probabilities

Repair of calcified left ventricular pseudoaneurysm of long duration

Cardiac pseudoaneurysm is a contained rupture of the myocardium limited by pericardial adhesions or the epicardial wall. Cardiac pseudoaneurysm may cause sudden death with a mortality of 30-45% in the first year, mostly resulting from rupture. Coronal and axial T2-weighted magnetic resonance images of a 65-year-old male patient admitted with dyspnoea, coughing and chest pain, present for the last 10 days, revealed a large pseudoaneursym of the left ventricle. Coronary bypass and left ventricular restoration operation was performed. The patient was eventlessly discharged 8 days after operation. He is in NYHA Class I 21 months postoperatively. The interval between myocardial insult and establishment of diagnosis is unknown in our patient. This is a patient whose left ventricular rupture had been contained for a very long time, possibly years, because a heavily calcified thick pseudoaneurysm wall was encountered during operation, making this case rare in the literature

Measurement of photon interaction parameters of high-performance polymers and their composites

WOS: 000438143300012In the present study, commercially important high-performance polymers and their composites have been investigated with respect to photon interactions as means of mass attenuation coefficient (/), mean free path (MFP), half-value layer (HVL), effective atomic number (Z(eff)), effective electron density (N-eff), and energy absorption and exposure buildup factors (EABF and EBF) at different photon energies. For this purpose, sample plates were prepared by extrusion and injection techniques using polyethersulfone, polyetherimide, acrylonitrile butadiene styrene copolymer, polyamide 66, polyphthalamide, and polypropylene copolymers as high-performance polymers and glass and carbon fibers as reinforcement. The (/) s of the materials were measured at 81 and 356keV photon energies to determine MFP, HVL, Z(eff), and N-eff. The theoretical values of these parameters were calculated via ZXCOM, WinXCom and Monte Carlo N-Particle simulation code (MCNP), and a good agreement was obtained between WinXCom-MCNP and MCNP-Exp. Finally, EABFs and EBFs of the samples were calculated up to around 40 MFP in the energy region 0.015-15MeV and significant variations were observed in the continuous energy and MFP regions

Thermal necrosis-aided dental implant removal:A rabbit model pilot study

The significant advances in the materials and biological aspects of dental implants haven?t completely eradicated the implant failures. The removal of osseointegrated but otherwise failed implants present several challenges including adjacent tissues damage and necessity of bone augmentation for reimplantation. Controlled thermal necrosis has emerged as an alternative technique to aid removal of osseointegrated dental implants with minimal to no defect to healthy bone or surrounding tissues. This study aimed to evaluate the thermal necrosis-aided implant removal method in a rabbit osseointegration model. A total of 8 male New Zealand rabbits were used in the study. Two dental implants were placed on each femur of the rabbits. Heating of the implants was performed after 7 weeks following the implantation. Heating was done by contacting the tip of an electrosurgey tool in monopolar mode at different power settings and contact durations (5W ? 2 seconds, 5W ? 10 seconds, and 10 W ? 10 seconds). No heating was done on the control group. Implant stability right after implantation, before heat application and after heat application was determined using an Osstell? Mentor Device. Following the removal of implants histological analyses were performed to determine the effects of heat application at cellular level. ISQ values of the 10W-10s group was significantly lower compared to the other groups (p<0.001). No indication of progressive necrosis or irreversible damage was observed in any of the groups. However, the percent of empty-apoptotic lacunae were statistically higher in the 5W-10s and the 10W-10s groups compared the control and the 5W-2s groups. Within the conditions of this study, we conclude that heat application with an electrosurgery tool using monopolar mode at 10W power for 10 seconds is optimal for reversing osseointegration with no extensive or progressive damage to the bone

Basic soil properties and soil classification of hazelnut cultivation area in the eastern black sea region, case study; Ünye-Tekkiraz district

The objective of this research was to investigate physical, chemical and morphological properties, classification and mapping of soils of hazelnut cultivation in Ünye-Tekkiraz district of The Eastern Black Sea Region. The study area is located between west of the Ordu and south of the Samsun provinces, at coordinates 4542495- 4537485 N and 342549-347523 E and total area is approximately 31.5 km2. Average annual precipitation and temperature are 1162.4 mm and 14.2 oC, respectively. Elevation varies from 200 m to 550 m above sea level. According to soil taxonomy, the soil temperature regime and moisture regime were classified as mesic and ustic, respectively. Most of the study areas have been commonly used for hazelnut cultivation, whereas southern part of the study area generally cover small forest and pasture lands. In the study area, distribution of geological pattern is palaeocene and eocene rocks consisting of sandstone, siltstone and marl including widely distributed and altered eocene aged volcano-clastics which are composed of basalt and andesite. After examination of topographic, land use, geologic and geomorphologic maps and land observation, 15 profile places were excavated in the study area. The soil samples were taken from each profile based on genetic horizons and their analyses were done in the laboratory. According to the results of laboratory analyses by taking into consideration of soil taxonomy, 11 different soil series were classified and described. Two them were classified as Entisol due to their young age and five are Inceptisol, three are Alfisol, and one is Vertisol. Whereas Hatipler seri has the largest area (14.7 %), Yenicuma Dere soil seri has the smallest area in the study area (3.2 %)

17,18-Dibromo-8-methyl-4,12-ditosyl-3,4,5,6,7,8,9,10,11,12,13,14-dodeca­hydro-2H-benzo[b][1,4,7,11,15]dioxatriaza­cyclo­hepta­decine

In the title compound, C31H39Br2N3O6S2, a 17-membered aza-macrocyclic ligand containing two ether O and three aza N atoms, the three pendant aromatic rings form an ‘E’ shape. The dihedral angles between the central benzene ring and the side ones are 17.8 (3) and 7.4 (3)°, and the dihedral angle between the tosyl rings is 10.6 (3)°. The methyl group is disordered over two orientations, with occupancies of 0.52 (15) and 0.48 (15)

Sex differences of migraine: Results of a nationwide home-based study in Turkey

Introduction: The prevalence of migraine was found to be more than three-fold higher in women as compared with men, and in addition to differences in prevalence rates, the characteristics and associated features might also differ between the sexes. The aim of this study was to compare sex-specific features of migraine and demographic parameters in a nationwide population-based study in Turkey. Methods: Among 5323 subjects, a total of 871 patients who were diagnosed as having definite migraine according to the diagnostic criteria of the International Classification of Headache Disorders-III (ICHD-III) were included in our study. The demographic characteristics, associated features, and triggers of migraine were examined with regard to sex. Results: The study group comprised 640 women (73.5%) and 231 men (26.5%), with a female to male ratio of 2.8:1. Attack duration, mean migraine disability assessment scores (MIDAS), frequencies of nausea, vomiting, osmophobia, vertigo/dizziness, and allodynia were found significantly different between women and men. When we compared these parameters between men and postmenopausal women, all these parameters were still significant except nausea. Odor was statistically more frequent as a reported trigger in women, whereas excessive sleep was a statistically more frequent triggering factor in men. The rates of depression and allergy were significantly higher in women when compared with men. Conclusion: Longer attack duration, higher MIDAS scores, and the frequencies of nausea, vomiting, osmophobia, vertigo/dizziness, and allodynia were more significant in women and this variance in sex persisted after menopause. Also, some trigger factors and co-morbidities differed between the sexes. These findings might result from complex genetic factors besides sociocultural influences, biologic, and sociocultural roles. Future studies should continue to explore biologic and genetic factors with respect to sex in migraine

Behaviour of 9-Ethyl-9H-carbazole Hydrazone Derivatives Against Oxidant Systems: Protective Effect on Amyloid β-Induced Damage

Antioxidants are helpful in prevention of several diseases related with oxidative stress including neurodegenerative disorders. In recent studies, carbazoles were given proof of promising antioxidant activities. In this article, 9-ethyl-9H-carbazole hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity and possible cytotoxic effects were investigated. Furthermore, protective effect of the synthesized derivatives against amyloid β-induced damage in PC12 neuronal cells was examined by using MTT assay. The newly synthesized carbazoles were found to have radical scavenging activity with a varying potency both in cell-free and cell-based in vitro assays. Several compounds, especially such as 3d and 3e, 3m and 3n bearing two halogen groups on the phenyl ring, were found to have cytotoxic activity. However, their cytotoxic activities were not higher than that of melatonin. Several compounds also significantly protected neuronal PC12 cells against amyloid β-induced damage, which can be defined as neuroprotective agents. (4-(2-((9-Ethyl-9H-carbazol-3-yl)methylene)hydrazinyl)benzonitrile) 3r was found as the most active compound with both radical scavenging activity and neuroprotective effects against amyloid β-induced damage. These findings might provide an alternative strategy for developing novel carbazole derivatives for management of neurodegenerative diseases, such as Alzheimer\u27s disease. This work is licensed under a Creative Commons Attribution 4.0 International License

4-[2-(Cyclo­hexa-1,4-dien-1-yl)eth­oxy]benzene-1,2-dicarbonitrile

In the title compound, C16H14N2O, the dihedral angle between the aromatic rings is 70.23 (6)°. The linking chain has a zigzag conformation. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯N hydrogen bonds, forming a zigzag chain along the c axis

SUCCESS OF ARTIFICIAL INTELLIGENCE SYSTEM IN DETERMINING ALVEOLAR BONE LOSS FROM DENTAL PANORAMIC RADIOGRAPHY IMAGES

Objectives: The aim of this study was to detect alveolar bone loss from dental panoramic radiographic images using artificial intelligence systems. Material and Methods: A total of 2276 panoramic radiographic images were used in this study. While 1137 of them belong to cases with bone destruction, 1139 were periodontally healthy. The dataset is divided into three parts as training (n=1856) , validation (n=210) and testing set (n= 210). All images in the data set were resized to 1472x718 pixels before training. A random sequence was created using the open-source python programming language and OpenCV, NumPy, Pandas, and Matplotlib libraries effectively. A pre-trained Google Net Inception v3 CNN network was used for preprocessing and data sets were trained using transfer learning. Diagnostic performance was evaluated with the confusion matrix using sensivitiy, specificity, precision, accuracy and F1 score. Results: Of the 105 cases with bone loss, 99 were detected by the AI system. Sensitivity was 0.94, specificity 0.88, precision 0.89, accuracy 0.91 and F1 score 0.91. Conclusion: The convolutional neural network model is successful in determining periodontal bone losses. It can be used as a system to facilitate the work of physicians in diagnosis and treatment planning in the future