Exchange Rate Volatility and Central Bank Actions in Egypt: Generalized Autoregressive Conditional Heteroscedasticity Analysis

Egypt has passed through different development stages, followed different exchange rate regime at each, ranging from fixed to floating. This study tries to examine empirically how Central Bank of Egypt actions influence exchange rate volatility using GARCH (1. 1) model under Gaussian normal distribution, considering monthly observations of Egyptian Pound against US Dollar, spanning the period from 2003 after the adoption of floating exchange rate regime till 2014. The model includes three exogenous variables as they can contribute to the exchange rate volatility; interest rate differentials, trade balance and official reserves. Results show the presence of volatility clustering but this volatility shocks are not so quite persistent. Central Bank actions impacted exchange rate volatility positively through interest rate, and negatively through reserves amount. Finding solutions to trade deficits to encourage exports and tackle down imports can hinder exchange rate volatility in Egypt. Keywords: Exchange Rate Volatility, GARCH, Monetary Policy JEL Classifications: C23, E5

Measuring Forest Canopy Water Mass in Three Dimensions Using Terrestrial Laser Scanning

\ua9 Author(s) 2023.Canopy water mass is an important plant characteristic that can indicate the water status of vegetation. However, the parameter remains under-investigated because measuring it requires defoliating the canopy. This study introduced a non-destructive approach to estimate canopy water mass using terrestrial laser scanning data. Tree 3D models were generated from dual-wavelength TLS data for six forest canopies, then the models were utilized in estimating the canopy LAI, total leaf area, and vertical profiles of canopy leaf area. The estimates were then coupled with canopy equivalent water thickness estimates and vertical profiles of canopy water mass were generated. The results revealed some over- and underestimation in the estimated LAI, but the obtained accuracy was considered sufficient as leaf-on point clouds were used to generate the 3D models. The vertical profiles of canopy water mass showed that the leaf area distribution within the canopy, and the canopy architecture were the main parameters affecting the water mass distribution within the canopy, with mid canopy layers having higher water mass than the other canopy layers. This study showed the potential of TLS to estimate canopy water mass, but controlled experiments that include defoliating canopies are still needed for a direct and accurate validation of the TLS estimates of canopy water mass

DDOS Botnets Attacks Detection in Anomaly Traffic: A Comparative Study.

One of the major challenges that faces the acceptance and growth rate of business and governmental sites is a Botnet-based DDoS attack. A flooding DDoS strikes a victim machine by means of sending a vast amount of malicious traffic, causing a significant drop in the service quality (QoS) in IoT devices. Nonetheless, it is not that easy to detect and tackle flooding DDoS attacks, owing to the significant number of attacking machines, the usage of source-address spoofing, and the common areas shared between legitimate and malicious traffic. New kinds of attacks are identified daily, and some remain undiscovered, accordingly, this paper aims to improve the traffic classification algorithm of network traffic, that hackers use to try to be ambiguous or misleading. A recorded simulated traffic was used for both samples; normal and DDoS attack traffic, approximately 104.000 cases of each, where both datasets -which were created for this study- represent the input data in order to create a classification model, to be used as a tool to mitigate the risk of being attacked. The next step is putting datasets in a format suitable for classification. This process is done through preprocessing techniques, to convert categorical data into numerical data. A classification process is applied to capture datasets, to create a classification model, by using five classification algorithms which are; Decision Tree, Support Vector Machine, Naive Bayes, K-Neighbours and Random Forest. The core code used for classification is the python code, which is controlled by a user interface. The highest prediction, precision and accuracy are obtained using the Decision Tree and Random Forest classification algorithms, which also have the lowest processing time

Kinetics and Isotherms Studies of Safranin Adsorption onto Two Surfaces Prepared from Orange Peels

Removal of safranin dye from aqueous solutions using two adsorbents prepared from orange peels (Orange peels powder DP-OP and hot activated carbon HAC-OP) has been investigated under different experimental conditions. The effect of pH, contact time, adsorbent mass, and initial concentration of studied dye on the adsorption process has been studied using batch experiments procedure. The concentration of remaining dye in the solution has been estimated by means of UV-VIS molecular absorption spectrometry. The highest removal of safranin has been achieved at pH (8-9) with a maximum removal efficiency of (96 and 97%) of dye after (30 and 50 min) of agitation time for DP-OP and HAC-OP, respectively. Freundlich isotherm model represents the best fit for the experimental data; whereas the highest adsorption capacities were 55.5 mg g-1 and 1.24 mg g-1 for DP-OP and HAC-OP, respectively. The pseudo-second-order rate equation fitted well kinetic profiles for both adsorbents

Effect of Yoghourt Starter Culture and Nickel Oxide Nanoparticles on the Activity of Enterotoxigenic Staphylococcus aureus in Domiati Cheese

Domiati cheese is the most popular type of white soft cheese in Egypt. Staphylococcus aureus is a common microorganism that can easily contaminate Domiati cheese during processing and distribution. Enterotoxigenic S. aureus strains produce staphylococcal enterotoxins (SE) that have been involved in food poisoning outbreaks worldwide. The aim of the present study was to examine the inhibitory effect of yoghourt starter culture and nickel oxide nanoparticles (NiO NPs) on the development of the enterotoxigenic S. aureus together with the enterotoxin production during the manufacturing and storage of Domiati cheese. Fresh cow’s milk was inoculated with S. aureus in a count of six log CFU/mL with the addition of either yoghourt starter culture or NiO Nps. The cytotoxicity of NiO NPs on normal human epithelial cells (HEC) was assessed using the MTT assay. In the current study, the inoculated milk was used for making Domiati cheese and the survival Weibull and log-linear models were fitted to the observed data. The obtained results showed that the mean log count of S. aureus decreased one week earlier by using yoghourt starter culture. Staphylococcal enterotoxin A (SEA) was identified only in the control cheese. Notably, Domiati cheese contained MIC of NiO NPs (35 µg/mL), which resulted in a significant decrease in S. aureus counts since at day 21 of cheese ripening it was not detected (<10 CFU/g). Overall, the current study indicated that the addition of yoghourt starter culture and NiO NPs during the processing of Domiati cheese could be useful candidates against S. aureus and enterotoxin production in the dairy industry

ADSORPTION OF Co (II) IONS FROM AQUEOUS SOLUTION ONTO TEA AND COFFEE POWDER: EQUILIBRIUM AND KINETIC STUDIES

Adsorption of Co(II) ions from aqueous solutions onto Tea and Coffee powders has been examined in a batch adsorption process. The adsorption of Co(II) ions was found to be dependent on contact time, pH of solution, initial metal ion concentration, and adsorbent dose. The experimental equilibrium adsorption data were studied by Langmuir, Freundlich, Temkin and Dubinin-Radushkevic isotherms models. The Langmuir model display demonstrated a superior fit than the other three models by higher correlation coefficient, R2. The maximum adsorption capacities calculated from the Langmuir isotherm model were 244 mg/g, for both coffee and tea at optimum circumstances. The kinetic studies denoted that the adsorption process of Co(II) ions followed well pseudo-second-order model. According to the adsorption capacity, coffee and tea powder considered as an effective, low cost, and environmentally friendly adsorbent for the removal of Co(II) ions from aqueous solutions

We don't know what you did last summer. On the importance of transparent reporting of reaction time data pre-processing

In behavioral, cognitive, and social sciences, reaction time measures are an important source of information. However, analyses on reaction time data are affected by researchers' analytical choices and the order in which these choices are applied. The results of a systematic literature review, presented in this paper, revealed that the justification for and order in which analytical choices are conducted are rarely reported, leading to difficulty in reproducing results and interpreting mixed findings. To address this methodological shortcoming, we created a checklist on reporting reaction time pre-processing to make these decisions more explicit, improve transparency, and thus, promote best practices within the field. The importance of the pre-processing checklist was additionally supported by an expert consensus survey and a multiverse analysis. Consequently, we appeal for maximal transparency on all methods applied and offer a checklist to improve replicability and reproducibility of studies that use reaction time measures

Contact lenses for color blindness

Color vision deficiency (color blindness) is an inherited genetic ocular disorder. While no cure for this disorder currently exists, several methods can be used to increase the color perception of those affected. One such method is the use of color filtering glasses which are based on Bragg filters. While these glasses are effective, they are high cost, bulky, and incompatible with other vision correction eyeglasses. In this work, a rhodamine derivative is incorporated in commercial contact lenses to filter out the specific wavelength bands (≈545–575 nm) to correct color vision blindness. The biocompatibility assessment of the dyed contact lenses in human corneal fibroblasts and human corneal epithelial cells shows no toxicity and cell viability remains at 99% after 72 h. This study demonstrates the potential of the dyed contact lenses in wavelength filtering and color vision deficiency management