Periodic gamma-ray emissions from Geminga at or = 10(12) eV

Analysis of data from an atmospheric Cerenkov telescope indicated the periodic emission of gamma rays of energy 10 to the 12th power eV, at 60.25 second period, from 2CG 195+4. The gamma ray flux at 99% confidence level is estimated to be 9.5 x 10 to 12 photons/sq cm/s

DDoS Attack Detection Using Cooperative Overlay Networks and Gossip Protocol

DDoS attacks have major impact on the affected networks viz. packet transmission delays, network outage, website sabotage, financial losses, legitimate-user blockage and reputation damage. Existing DDoS detection techniques are either implemented at the victim node (but the damage is already done) or at many intermediate routers which run DDoS detection algorithms, that adds additional delay and more processing. We aim to detect DDoS attacks by using a new technique of cooperative overlay networks which overcomes the above problems by implementing the DDoS detection algorithm at one hop distance nodes (called defense nodes) from the victim. DOI: 10.17762/ijritcc2321-8169.15062

Load Adaptive Caching Points for a Content Distribution Network

The unprecedented growth in content demand on smartphones has significantly increased the energy consumption of current cellular and backbone networks. Apart from achieving stringent carbon footprint targets, provisioning high data rates to city vehicular users while maintaining quality of service (QoS) remains a serious challenge. In previous work, to support content delivery at high data rates, the number and locations of caching points (CPs) within a content distribution network (CDN) were optimized while reducing the operational energy consumption compared to typical cellular networks. Further reduction in energy consumption may be possible through sleep cycles, which reduces transmission energy consumption. However, sleep cycles degrade the quality of service. Therefore, in this paper, we propose a novel load adaptation technique for a CP which not only enhances content download rate but also reduces transmission energy consumption through random sleep cycles. Unlike a non-load adaptive (deterministic) CP, the performance results reveal that the load adaptive CP achieves considerably lower average piece delay (approximately 60% on average during the day), leveraging the introduction of random sleep cycles to save transmission energy. The proposed CP saves up to 84% transmission energy during off-peak hours and 33% during the whole day while fulfilling content demand in a city vehicular environment

Effect of Modified Atmosphere Packaging on Maintenance of Quality in Apple

An experiment was conducted to study the effect of modified atmosphere packaging (MAP) on the quality of 'Red Delicious' and 'Golden Delicious' apples. Freshly harvested fruits were wiped clean and (25 μm thick) with varying number of perforations and stored in cardboard boxes at ambient temperature. 'Golden Delicious' showed higher incidence of bitter pit as compared to 'Red Delicious' apples. MAP proved effective in controlling the bitter pit disorder and in maintenance of quality. The least incidence of bitter pit in 'Golden Delicious' was recorded with T4 (30 x 2 mm perforation) and T3 (20 x 2 mm) treatment in 'Red Delicious' apples. However, MAP retained more freshness in 'Golden Delicious' than in 'Red Delicious'

Alterations in stem sugar content and metabolism in sorghum genoptypes subjected to drought stress

Changes in stem sugar content due to drought stress imposed at the early reproductive stage were studied in seven genotypes of sorghum differing in their ability to store stem sugar. Out of the seven genotypes, two genotypes (ICSSH 58 and SPV 1411) that showed little variation in total sugar levels at the 5th internode from the peduncle on exposure to drought treatment and five genotypes (ICSV 25275, ICSV 25280, PVK801, RSSV 9 and M 35-1) that showed significant increases in total sugar levels on drought exposure, were grouped and used for comparative studies on sugar metabolism. Drought stress led to a decrease in sucrose synthase activity in the catabolic direction in both groups. However, neutral and acid invertase activities increased significantly in the genotypes ICSSH 58 and SPV 1411, and correlated to the increase in reducing sugar content on exposure to drought. Hydrolysis of stem sugars probably had a role to play in osmotic adjustment on exposure to drought stress and correlated to retention of sap volume in these genotypes. However the activities of sugar metabolizing enzymes did not correlate to their gene expression levels. On resuming irrigation after twenty days of drought stress and studying the yield parameters at physiological maturity stage, it was observed that grain yields, stalk yields and juice volume were lower in the plants recovering from drought stress as compared to the irrigated controls. In some genotypes like ICSV25275, ICSSH58 and M35-1, there were similar losses in grain yields and stem sugars due to the brief drought exposure, indicating source limitation of photoassimilates. However, in other genotypes like ICSV25280, PVK801 and RSSV9, grain yield losses were less than stem sugar losses in drought exposed plants as compared to controls, suggesting mobilization of sugars from the storage internodes to the developing panicle, to ensure viable progeny. Hence accumulation of stem sugars appears to be an adaptive strategy in some, but not all sorghum genotypes, against drought stress

Regulation of voltage and frequency in solid oxide fuel cell-based autonomous microgrids using the Whales optimisation algorithm

This study explores the Whales Optimization Algorithm (WOA)-based PI controller for regulating the voltage and frequency of an inverter-based autonomous microgrid (MG). The MG comprises two 50 kW DGs (solid oxide fuel cells, SOFCs) interfaced using a power electronics-based voltage source inverter (VSI) with a 120-kV conventional grid. Four PI controller schemes for the MG are implemented: (i) stationary PI controller with fixed gain values (Kp and Ki), (ii) PSO tuned PI controller, (iii) GWO tuned PI controller, and (iv) WOA tuned PI controller. The performance of these controllers is evaluated by monitoring the system voltage and frequency during the transition of MG operation mode and changes in the load. The MATLAB/SIMULINK tool is utilised to design the proposed model of grid-tied MG alongside the MATLAB m-file to apply an optimisation technique. The simulation results show that the WOA-based PI controller which optimises the control parameters, achieve 62.7% and 59% better results for voltage and frequency regulation, respectively. The eigenvalue analysis is also provided to check the stability of the proposed controller. Furthermore, the proposed system also satisfies the limits specified in IEEE-1547-2003 for voltage and frequency

Assessment of Wind Power Potential Based on Raleigh Distribution Model: An Experimental Investigation for Coastal Zone

When compared with other renewable energy resources (RER), the wind energy share in the global energy production is increasing rapidly. Currently, the Government of Pakistan (GoP) is moving towards RER, specifically wind and solar energy. In this paper, the wind energy potential of Tando Ghulam Ali, Sindh, Pakistan is explored. For this purpose, one-year wind speed data is considered at various heights through various probability distribution functions (PDFs). Statistical comparison of Rayleigh, gamma, generalized extreme value (GEV) and lognormal PDFs have been done with two methods, namely root mean square error and (R^2) in order to select the best PDF. Results showed that the Rayleigh distribution function is the best at the above mentioned area for finding various factors like site selection and wind power cost per kWh

Reconstructing promoter activity from Lux bioluminescent reporters

The bacterial Lux system is used as a gene expression reporter. It is fast, sensitive and non-destructive, enabling high frequency measurements. Originally developed for bacterial cells, it has also been adapted for eukaryotic cells, and can be used for whole cell biosensors, or in real time with live animals without the need for euthanasia. However, correct interpretation of bioluminescent data is limited: the bioluminescence is different from gene expression because of nonlinear molecular and enzyme dynamics of the Lux system. We have developed a computational approach that, for the first time, allows users of Lux assays to infer gene transcription levels from the light output. This approach is based upon a new mathematical model for Lux activity, that includes the actions of LuxAB, LuxEC and Fre, with improved mechanisms for all reactions, as well as synthesis and turn-over of Lux proteins. The model is calibrated with new experimental data for the LuxAB and Fre reactions from Photorhabdus luminescens --- the source of modern Lux reporters --- while literature data has been used for LuxEC. Importantly, the data show clear evidence for previously unreported product inhibition for the LuxAB reaction. Model simulations show that predicted bioluminescent profiles can be very different from changes in gene expression, with transient peaks of light output, very similar to light output seen in some experimental data sets. By incorporating the calibrated model into a Bayesian inference scheme, we can reverse engineer promoter activity from the bioluminescence. We show examples where a decrease in bioluminescence would be better interpreted as a switching off of the promoter, or where an increase in bioluminescence would be better interpreted as a longer period of gene expression. This approach could benefit all users of Lux technology

Optimization of cell-laden bioinks for 3D bioprinting and efficient infection with influenza A virus

Bioprinting is a new technology, which arranges cells with high spatial resolution, but its potential to create models for viral infection studies has not yet been fully realized. The present study describes the optimization of a bioink composition for extrusion printing. The bioinks were biophysically characterized by rheological and electron micrographic measurements. Hydrogels consisting of alginate, gelatin and Matrigel were used to provide a scaffold for a 3D arrangement of human alveolar A549 cells. A blend containing 20% Matrigel provided the optimal conditions for spatial distribution and viability of the printed cells. Infection of the 3D model with a seasonal influenza A strain resulted in widespread distribution of the virus and a clustered infection pattern that is also observed in the natural lung but not in two-dimensional (2D) cell culture, which demonstrates the advantage of 3D printed constructs over conventional culture conditions. The bioink supported viral replication and proinflammatory interferon release of the infected cells. We consider our strategy to be paradigmatic for the generation of humanized 3D tissue models by bioprinting to study infections and develop new antiviral strategies.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität Berli

Effectiveness of single dose oral dexamethasone versus multidose prednisolone for treatment of acute exacerbations of asthma among children

Asthma is one of the most common chronic diseases in children and worldwide its prevalence has increased dramatically in the last three decades. We aimed to compare single dose oral dexamethasone versus multiple doses of oral prednisolone in children with acute exacerbation of asthma in terms of post treatment requirement of systemic steroids. This Randomized control trial has been conducted in the Department of paediatrics, KRL Hospital, Islamabad from Dec 2018 to June 2019.312 patients between the age of 2-12 years patients were randomized into Group A receiving a STAT single dose of oral dexamethasone 0.3 mg/kg and Group B receiving prednisolone 1 mg/kg/day followed by two doses on Day 2 and 3. further dose of systemic steroids were ascertained through PRAM score. In this study mean age in Group A was 8 years with SD ± 5.68 while mean age in Group B was 7 years with SD ± 6.12. In Group A 58% patients were male and 42% patients were female. Whereas in Group B 59% patients were male and 41% patients were female. In Group A 12% patients had further requirement of systemic steroids while in Group B 18% patients had further requirement of systemic steroids while 82% patients didn't had further requirement of systemic steroids. Our study concludes that post treatment requirement of systemic steroids is less in single dose oral dexamethasone as compare to multiple doses of oral prednisolone in children with acute exacerbation of asthma. [Abstract copyright: © 2022 The Authors.