The Design and development of secure password synchronization and querting system for the enterprise networks /

Organizations that run large computer networks should also provide maintenance for the computers on these networks. Nowadays, it is a common practice to outsource this maintenance task to specialized service firms. These service firms may not be considered trustworthy. Therefore, the local administrator password of a local machine that a maintenance technician needs to access should be changed periodically. Consequently, the technician needs a way to learn the current local administrator password of each computer. In this thesis, a secure password synchronization and querying system is presented. In this system, the local administrator passwords of computers are changed periodically in synchronization with a server managing the system. The maintenance technicians can learn the current password of a computer by querying the server. For synchronization and querying mechanisms, we propose three secure protocols that employ symmetric and asymmetric encryption techniques. Moreover, in this thesis, the proposed protocols are implemented as a software product and the performance of the system is evaluated by simulating the system. The average of the number of successful synchronizations stays constant when the number of computers is increased from 3,000 to 20,000 in the simulation. An increase in the number of computers doesn't change the behavior of the system. In addition, it is shown that the system can be configured to survive under rough network conditions. The implementation details and the performance evaluation of the system are presented in the thesis

Determination of microbiological quality of boiled crayfish (<i>Astacus leptodactylus</i>) samples treated with chitosan

Coating crayfish (Astacus leptodactylus) meat samples with chitosan solution could be an effective approach to limit microbiological spoilage. During the 18-day-cold storage period at 2degree celsius +/- 1, Mesophilic Aerobic Bacteria (MABc), Psychrophilic Bacteria (PBc), Yeast Mold count (YMc), Anaerobic Bacteria (AABc), and Enterobacteriaceae growth in the samples coated with chitosan (0.5% and 1%) and also control group samples were tested. Crayfish samples coated with chitosan (0.5% and 1%) had a lower TMABc (6.58 to 4.60 log CFU/g: up to 30.09%), TPBc (3.77 to 1.99 log CFU/g: up to 47.21%), TYMc (1.84 to 1.27 log CFU/g: up to 30.97%), TAABc (3.69 to 1.88 log CFU/g: up to 49.05%), and Enterobacteriaceae (3.49 to 2.60 log CFU/g: up to 25.50%) counts as compared with control group samples at 2degree celsius +/- 1. The results particularly based on mesophilic anaerobic bacteria suggested that the application would be a promising approach to limit microbial growth and provide food safety for boiled crayfish meat samples

Estimation of monthly diffuse nutrient loads for a watershed in Turkey

Diffuse pollution has a complex nature depending on various land-use activities like agriculture, livestock breeding and forestry. In this study, an alternative methodology is applied for decreasing the spatial uncertainty of diffuse nutrient load estimations. It is applied in the Melen Watershed, Turkey, which is an important watershed from where additional water will be supplied for the megacity Istanbul via interbasin water transfer. Monthly diffuse nutrient loads were estimated for each subwatershed by utilizing remote sensing (RS) and geographical information systems (GIS). Estimated nutrient loads were considerably different in various months due to the temporally irregular fertilizer application and meteorological conditions. Temporal differences were also predicted in the spatial distribution of the nutrient loads. The methodology is applicable in watershed protection studies, especially where necessary etudes should be conducted in the short term and with limited data. Such efforts in identifying and determining the diffuse loads are important for sustainable management of the watershed

Water quality assessment and meta model development in Melen watershed - Turkey

Istanbul, being one of the highly populated metropolitan areas of the world, has been facing water scarcity since the past decade. Water transfer from Melen Watershed was considered as the most feasible option to supply water to Istanbul due to its high water potential and relatively less degraded water quality. This study consists of two parts. In the first part, water quality data covering 26 parameters from 5 monitoring stations were analyzed and assessed due to the requirements of the "Quality Required of Surface Water Intended for the Abstraction of Drinking Water" regulation. In the second part, a one-dimensional stream water quality model with simple water quality kinetics was developed. It formed a basic design for more advanced water quality models for the watershed. The reason for assessing the water quality data and developing a model was to provide information for decision making on preliminary actions to prevent any further deterioration of existing water quality. According to the water quality assessment at the water abstraction point, Melen River has relatively poor water quality with regard to NH4+, BOD5, faecal streptococcus, manganese and phenol parameters, and is unsuitable for drinking water abstraction in terms of COD, PO43-, total coliform, total suspended solids, mercury and total chromium parameters. The results derived from the model were found to be consistent with the water quality assessment It also showed that relatively high inorganic nitrogen and phosphorus concentrations along the streams are related to diffuse nutrient loads that should be managed together with municipal and industrial wastewaters. (C) 2010 Elsevier Ltd. All rights reserved

Application of water quality modelling as a decision support system tool for planned Buyuk Melen reservoir and its watershed

Istanbul, the largest metropolis of Turkey and one of the most crowded metropolises in the world, is facing the risk of water scarcity. Analyses indicated that one of the alternative solutions coping with this problem is water transfer from a watershed that is located outside the administrative boundaries of Istanbul. Due to its water potential and relatively less degraded water quality Buyuk Melen Watershed was considered to be the most feasible option. As the result of analyses, State Hydraulic Works (DSI) has planned construction of a reservoir in the Buyuk Melen Watershed to supply the required amount of water for Istanbul also in low flow seasons. Since the reservoir will be located at the downstream region of the watershed, its water quality will be affected by human-induced activities, thus measures need to be taken to prevent pollution prior to reservoir construction. Quantifying the response of the planned reservoir to external pollution loads is an important step in the planning and management of the watershed. Mathematical modelling is a useful tool for estimating the future water quality and understanding the possible responses of the reservoir to various pollution loads. In this study, a water quality model capable of simulating hydrodynamics, transport and water quality in reservoirs is used for preliminary estimation of possible impacts of several management options in the watershed. Model results indicated that, all of the point sources in the watershed must be controlled by advanced wastewater treatment and should be diverted from the streams and the planned reservoir. Model results also indicated that reduction of agricultural diffuse loads by 30-40% is expected to have a perceptible improvement of reservoir water quality

Time-of-day dependent neuronal injury after ischemic stroke: Implication of circadian clock transcriptional factor bmal1 and survival kinase akt

WOS: 000426897800060PubMed ID: 28421530Occurrence of stroke cases displays a time-of-day variation in human. However, the mechanism linking circadian rhythm to the internal response mechanisms against pathophysiological events after ischemic stroke remained largely unknown. To this end, temporal changes in the susceptibility to ischemia/reperfusion (I/R) injury were investigated in mice in which the ischemic stroke induced at four different Zeitgeber time points with 6-h intervals (ZT0, ZT6, ZT12, and ZT18). Besides infarct volume and brain swelling, neuronal survival, apoptosis, ischemia, and circadian rhythm related proteins were examined using immunohistochemistry, Western blot, planar surface immune assay, and liquid chromatography-mass spectrometry tools. Here, we present evidence that midnight (ZT18; 24:00) I/R injury in mice resulted in significantly improved infarct volume, brain swelling, neurological deficit score, neuronal survival, and decreased apoptotic cell death compared with ischemia induced at other time points, which were associated with increased expressions of circadian proteins Bmal1, PerI, and Clock proteins and survival kinases AKT and Erk-1/2. Moreover, ribosomal protein S6, mTOR, and Bad were also significantly increased, while the levels of PRAS40, negative regulator of AKT and mTOR, and phosphorylated p53 were decreased at this time point compared to ZT0 (06:00). Furthermore, detailed proteomic analysis revealed significantly decreased CSKP, HBB-1/2, and HBA levels, while increased GNAZ, NEGR1, IMPCT, and PDE1B at midnight as compared with early morning. Our results indicate that nighttime I/R injury results in less severe neuronal damage, with increased neuronal survival, increased levels of survival kinases and circadian clock proteins, and also alters the circadian-related proteins.Necmettin Erbakan University [161330001]; Turkish Academy of Sciences (TUBA)This study was supported by The Turkish Academy of Sciences (TUBA) and Necmettin Erbakan University (Scientific Research Project: 161330001)