Electromagnetic emission-aware schedulers for the uplink of OFDM wireless communication systems

The popularity and convergence of wireless communications have resulted in continuous network upgrades in order to support the increasing demand for bandwidth. However, given that wireless communication systems operate on radiofrequency waves, the health effects of electromagnetic emission from these systems are increasingly becoming a concern due to the ubiquity of mobile communication devices. In order to address these concerns, we propose two schemes (offline and online) for minimizing the EM emission of users in the uplink of OFDM systems, while maintaining an acceptable quality of service. We formulate our offline EM reduction scheme as a convex optimization problem and solve it through water-filling. This is based on the assumption that the long-term channel state information of all the users is known. Given that, in practice, long-term channel state information of all the users cannot always be available, we propose our online EM emission reduction scheme, which is based on minimizing the instantaneous transmit energy per bit of each user. Simulation results show that both our proposed schemes significantly minimize the EM emission when compared to the benchmark classic greedy spectral efficiency based scheme and an energy efficiency based scheme. Furthermore, our offline scheme proves to be very robust against channel prediction errors

A User Scheduling Scheme for Reducing Electromagnetic (EM) Emission in the Uplink of Mobile Communication Systems

The ubiquity and convergence of wireless communication services have contributed to an unprecedented popularity of mobile communications. Given that wireless communication systems operate on radiofrequency waves, the electromagnetic (EM) radiation exposure they generate is also unprecedented and, hence, this could have adverse health effects on both humans and animals according to the World Health Organization. In this paper, we propose a user scheduling/power allocation scheme to minimize the EM exposure of users subject to transmitting a target number of bits. Our user scheduling method is based on assigning priority levels to each user and the user with the lowest priority level is scheduled for transmission. Power allocation, on the other hand, is based on the water-filling approach over time by using the past channel gains of a user to compute its water level. Simulation results show that our proposed scheme performs much better than a spectral efficiency based scheme but has a higher EM emission in comparison with a non-practical ideal scheme

Spectral Efficiency Improvements in HetNets by Exploiting Device-to-Device Communications

Next generation cellular networks require huge capacity, ubiquitous coverage and maximum energy efficiency. In order to meet these targets, Device-to-device (D2D) communication is being considered for future heterogeneous networks (HetNets). In this paper, we consider a three tier hierarchical HetNet by exploiting D2D communication in traditional HetNet. D2D communication is deployed within the HetNet where closely located mobile users are engaged in direct communication without routing the traffic through cellular access network. The proposed configuration mandates to reduce the interference offered by the resultant HetNet by reducing the transmitter-receiver distance and ensuring that the mobile users are transmitting with adaptive power subject to maintaining their desired link quality. In this context, we analyzed and compared the spectral efficiency improvements in hierarchical HetNet against traditional HetNet. Simulation results show that D2D communication offers much higher spectral efficiency as compared to traditional HetNet

Effect of stocking density of fish on water quality and growth performance of European Carp and leafy vegetables in a low-tech aquaponic system

Aquaponics (AP) is a semi-closed system of food production that combines aquaculture and hydroponics and represents a new agricultural system integrating producers and consumers. The aim of this study was to test the effect of stocking densities (APL, 2.5 kg m-3; APH, 4.6 kg m-3) on water quality, growth performance of the European Carp (Cyprinus carpio L.), and yield of leafy vegetables (catalogna, lettuce, and Swiss Chard) in a low-technology AP pilot system compared to a hydroponic cultivation. The AP daily consumption of water due to evapotranspiration was not different among treatments with an average value of 8.2 L d-1, equal to 1.37% of the total water content of the system. Dissolved oxygen was significantly (p < 0.05) different among treatments with the lowest median value recorded with the highest stocking density of fish (5.6 mg L-1) and the highest median value in the hydroponic control (8.7 mg L-1). Marketable yield of the vegetables was significantly different among treatments with the highest production in the hydroponic control for catalogna (1.2 kg m-2) and in the APL treatment for Swiss Chard (5.3 kg m-2). The yield of lettuce did not differ significantly between hydroponic control and APL system (4.0 kg m-2 on average). The lowest production of vegetables was obtained in the APH system. The final weight (515 g vs. 413 g for APL and APH, respectively), specific growth rate (0.79% d-1 vs. 0.68% d-1), and feed conversion (1.55 vs. 1.86) of European Carp decreased when stocking density increased, whereas total yield of biomass was higher in the APH system (4.45 kg m-3 vs. 6.88 kg m-3). A low mortality (3% on average) was observed in both AP treatments. Overall, the results showed that a low initial stocking density at 2.5 kg m-3 improved the production of European Carp and of leafy vegetables by maintaining a better water quality in the tested AP system

Assessment of heavy metals in water and fish from Ibrahim Adamu Lake, Jigawa, Nigeria

The study was conducted to assess the levels of heavy metals in water and the flesh of tilapia (Oreochromis niloticus). Water and tilapia were sampled for a period of 12 months from October, 2003-september 2004. Water and muscle tissue were analysed for Cu, Cr, pb, and Zn using flame atomic absorption spectrophotometer. The assessment showed Cr (3.35mg/l), Cu (0.75mg/l), pb (0.81mg/l) in water while Cr(2.27mg/kg) and pb (0.27mg/kg) were found to be high in the tissue samples and were above the values recommended by WHO and the Food and Agricultural Organization (FAO)of the United Nations and therefore not safe for human consumption

A Survey on the Path Computation Element (PCE) Architecture

Quality of Service-enabled applications and services rely on Traffic Engineering-based (TE) Label Switched Paths (LSP) established in core networks and controlled by the GMPLS control plane. Path computation process is crucial to achieve the desired TE objective. Its actual effectiveness depends on a number of factors. Mechanisms utilized to update topology and TE information, as well as the latency between path computation and resource reservation, which is typically distributed, may affect path computation efficiency. Moreover, TE visibility is limited in many network scenarios, such as multi-layer, multi-domain and multi-carrier networks, and it may negatively impact resource utilization. The Internet Engineering Task Force (IETF) has promoted the Path Computation Element (PCE) architecture, proposing a dedicated network entity devoted to path computation process. The PCE represents a flexible instrument to overcome visibility and distributed provisioning inefficiencies. Communications between path computation clients (PCC) and PCEs, realized through the PCE Protocol (PCEP), also enable inter-PCE communications offering an attractive way to perform TE-based path computation among cooperating PCEs in multi-layer/domain scenarios, while preserving scalability and confidentiality. This survey presents the state-of-the-art on the PCE architecture for GMPLS-controlled networks carried out by research and standardization community. In this work, packet (i.e., MPLS-TE and MPLS-TP) and wavelength/spectrum (i.e., WSON and SSON) switching capabilities are the considered technological platforms, in which the PCE is shown to achieve a number of evident benefits

Progress Report on Implementation of Regional Committee Resolution AFR/RC59/R3 on Accelerated Malaria Control

Several resolutions have been adopted and commitments made to scale up malaria control towards elimination in the African Region. These include United Nations, African Union, regional economic communities, World Health Assembly and Regional Committee resolutions. WHO AFRO provides support to countries, regional economic communities and the African Union in planning, implementing monitoring and evaluating their malaria control and elimination strategies. WHO also provides guidance and support for capacity building and resource mobilization towards reduction of the burden of malaria. As a result of scaling up evidence-based and high impact malaria interventions, the overall estimated incidence of malaria in the African Region fell by 33% from 2000 to 2010 and the upward trend of the disease was reversed. Furthermore, 12 countries in the African Region are on track to reduce malaria incidence by at least 50–75% by 2015. The action points of Resolution RC 59/R3 on Accelerated Malaria Control: Towards Elimination in the African Region remain relevant and should continue to guide countries in the context of their broader health, development and poverty reduction agenda.\u

Epidemiological aspects of surgical site infections in an income country. The case of regional hospital center, Borgou (Benin)

ABSTRACT Background: Surgical site infection is frustrating for the care team and depressing for the patient. Objective: To determine the epidemiological aspects of surgical site infections in regional hospital, Borgou. Methods: The study was crossed with prospective data collection. Recruitment was done for six months (from February 2013 to July 2013), each patient operated in both surgical services (general surgery and maternity) consents to be followed for one month or year. The surgical site infection was defined according to the CDC/NHSN 2009. Results: The frequency of surgical site infections was 7.3% (44/603). The mean age was 30.7 ± 15.8 years with minimum and maximum of 5 months and 70 years, respectively. They were significantly (p<0.05) more common in general surgery than that of maternity and visceral surgery and obstetrics were more concerned (14/44 each); the median time to SSI onset was 7.8 ± 3.8 days. The deep incisional infection was the most frequent (34/44). The most encountered organism was Escherichia coli (64.7%); multidrug resistance was 41.2%. The healing time averaged 30.5 ± 13.8 days with minimum and maximum of 20 and 92 days. Conclusion: Monitoring measures must be taken to reduce surgical site infection at the Regional Hospital Centre of Borgou.Background: Surgical site infection is frustrating for the care team and depressing for the patient. Objective: To determine the epidemiological aspects of surgical site infections in regional hospital, Borgou. Methods: The study was crossed with prospective data collection. Recruitment was done for six months (from February 2013 to July 2013), each patient operated in both surgical services (general surgery and maternity) consents to be followed for one month or year. The surgical site infection was defined according to the CDC/NHSN 2009. Results: The frequency of surgical site infections was 7.3% (44/603). The mean age was 30.7 ± 15.8 years with minimum and maximum of 5 months and 70 years, respectively. They were significantly (p<0.05) more common in general surgery than that of maternity and visceral surgery and obstetrics were more concerned (14/44 each); the median time to SSI onset was 7.8 ± 3.8 days. The deep incisional infection was the most frequent (34/44). The most encountered organism was Escherichia coli (64.7%); multidrug resistance was 41.2%. The healing time averaged 30.5 ± 13.8 days with minimum and maximum of 20 and 92 days. Conclusion: Monitoring measures must be taken to reduce surgical site infection at the Regional Hospital Centre of Borgou