Symptomatic scrotoliths in a child

Amelanotic/hypomelanotic variant of cellular blue naevus (CBN) can present a challenge for the clinician and histopathologist. We report a case of amelanotic/hypomelanotic variant of CBN that presented as a painless scrotal swelling in a child. We review the literature on amelanotic/hypomelanotic CBN, the key histological features and important differential diagnoses

Radio Frequency/Free Space Optical and Radio Frequency-only Wireless Sensor Networks: A Comparative Study of Performance

Wireless sensor networks (WSNs) consist of networked sensor nodes, deployed to sense a phenomenon and report it to a base station. Sensor nodes are small and usually equipped with small batteries with limited capacity, and therefore, one of the most important design considerations for WSNs is power consumption. WSNs expend energy for communications, data processing and sensing; for commonly used RF communications this task accounts for the largest portion of power expended. Hybrid radio frequency/free space optical (RF/FSO) communications has been proposed to reduce power consumption by the sensor node, and in this paper, the performance of the RF/FSO WSN is compared against an RF-only WSN in terms of network lifetime and coverage. Results show that for the wide range of scenarios considered, the RF/FSO WSN lasts at least twice as long as its RF-only counterpart, despite providing the same level of network coverage. This paper also investigates network parameter selection for optimum RF/FSO network coverage. © 2010 by the IETE

Occupational stress and its impact on employees' performance in District Secretariat - Jaffna

This study investigates the relationship between occupational stress and employees' performance. Stress is inevitable to the most of working individuals at their work and work place. Organizations have to take action to reduce the stress. The determinants of occupational stress that have been examined under this study include physical environmental stressors, individual stressors, group stressors and organizational stressors. The sample consists of District Secretariat employees from Jaffna in Sri Lanka. Field study was conducted with questionnaire as the primary data collection instrument. Data was analyzed using statistical technique with SPSS having the version of 13.0. The results show that the most important factors in determining the stress are role ambiguity, noise, temperature and polluted air. The most important factors in determining the employees' performance are labour turnover, initiative skill and no of grievances. The results also show that there is significant negative relationship between occupational stress and employees' performance

Radio Frequency/Free Space Optical and Radio Frequency-only Wireless Sensor Networks: A Comparative Study of Performance

Wireless sensor networks (WSNs) consist of networked sensor nodes, deployed to sense a phenomenon and report it to a base station. Sensor nodes are small and usually equipped with small batteries with limited capacity, and therefore, one of the most important design considerations for WSNs is power consumption. WSNs expend energy for communications, data processing and sensing; for commonly used RF communications this task accounts for the largest portion of power expended. Hybrid radio frequency/free space optical (RF/FSO) communications has been proposed to reduce power consumption by the sensor node, and in this paper, the performance of the RF/FSO WSN is compared against an RF-only WSN in terms of network lifetime and coverage. Results show that for the wide range of scenarios considered, the RF/FSO WSN lasts at least twice as long as its RF-only counterpart, despite providing the same level of network coverage. This paper also investigates network parameter selection for optimum RF/FSO network coverage. © 2010 by the IETE

Lifetime comparison of RF-only and hybrid RF/FSO wireless sensor networks

One of the main design considerations for wireless sensor networks (WSNs) is the energy consumption of individual sensor nodes. Currently, most WSNs use radio frequency (RF) channels for communications, and this accounts for a significant portion of the energy expended. Free space optical (FSO) communications have been proposed for WSNs, due to the lower communications energy required. However, for FSO communications, line of sight (LOS) is required between the transmitter and the receiver. The hybrid Radio Frequency/Free Space Optical (RF/FSO) WSN has been proposed to lower the overall energy consumption of the traditional RF-only WSN. In this paper, lifetime simulations of hybrid RF/FSO WSNs are described and compared against that of RF-only based WSNs. This paper shows that for the range of scenarios considered, the RF/FSO WSN outlasts its traditional RF-only counterpart. ©2008 IEEE

Study of clay intercalation with organic dyes

Not available

RF/FSO Wireless Sensor Networks: A performance study

Power consumption is an important design consideration for wireless sensor networks (WSNs). Hybrid radio frequency/free space optical (RF/FSO) WSNs have the potential to reduce this power consumption substantially. This paper studies the performance of the RF/FSO WSN by comparing its network lifetime against the lifetime of a traditional RF-only WSN. Two types of networks are considered: reconfiguring and non-reconfiguring networks. The results show that for the range of network parameters considered, the RF/FSO WSN lasts at least twice as long as its RF-only counterpart. This paper also discusses parameter selection for the best RF/FSO network coverage. © 2008 IEEE

Heart failure in Asia: The present reality and future challenges

10.1093/eurheartj/sur037European Heart Journal, Supplement14SUPPL. AA51-A52EHJS