On the Use of General Non-Linear Detector for a Delay Locked Hoop

This paper presents the performance comparison on the use of general non-linear dectors in a non-coherent delay locked tracking scheme for direct-seuence spreqd-spectrum systems. In the dalay locked loop (DLL), the square law-enevelope detectors are replaced by a full wave (even) nth - law detectors and this scheme is analysed in the presence of additive white gaussian noise. The tracking error of the DLL is compared for different values of n (n=0.5, 1, 2, 3, respectively). The results shows that the tracking error of the DLL can be reduced further in low signal to nose power ratio region by using the full wave (even) nth -law detectors for n<2 when compare with using the square law enevelope detectors (n=2).published_or_final_versio

Half-sine and triangular despreading chip waveforms for coherent delay-locked tracking in DS/SS systems

The performance of a coherent delay-locked tracking scheme for direct-sequence/spread-spectrum systems using half-sine or triangular chip waveforms for early and late despreading sequences is analyzed. The effect of band-limiting on the received signals is considered. Mean time to lose lock (MTLL) and root mean square (rms) tracking error of the delay-locked loop (DLL) are compared with that of a conventional DLL which uses rectangular chip despreading waveforms. Linear and nonlinear (based on the renewal process approach) analyses are employed to evaluate the performance of the DLL. Results show that the use of either the half-sine or triangular chip waveform reduces the rms tracking error and increases the MTLL considerably when the early-late spacing is approximately between 0.7-1.3 chip times. The results apply in particular to the commonly used DLL using one chip early-late spacing. Computer simulation for band-limited signals confirms the analytical results. The use of these despreading chip waveforms also reduces tracking offset in multipath environments.published_or_final_versio

PN code tracking for exponentially weighted chip despreading sequence

This paper presents the code tracking performance on the use of weighted chip despreading PN sequence in a coherent delay locked tracking scheme for direct-sequence spread-spectrum (DS/SS) systems. In the delay locked loop (DLL), the conventional rectangular chip waveform for early and late despreading PN sequences is replaced by weighted exponential chip waveform. The chip weight (γ) is tuned to optimize the DLL performance. The early-late spacing is considered as one chip time. This scheme is analyzed for both ideal and band limited received signals in the presence of additive white Gaussian noise.published_or_final_versio

Serological prevalence of Leptospiral infection in wildlife in Sarawak, Malaysia

Leptospirosis is a zoonotic disease caused by pathogenic leptospiral bacteria, which are transmitted directly or indirectly from animals to humans or animal to animal. The first phase of this proposed study was carried out to determine the extent of exposure to leptospirosis in wild mammals surrounded by human settlements around wildlife or tourism area (Wind Cave, Fairy Cave, Bako National Park and Matang Wildlife Center). This study reports an incident of leptospirosis among primates (three captive and two free ranging), rats, bats, squirrels and mongoose around Kuching, Sarawak area, which has been screened for Leptospirosis. Blood samples were obtained to determine the presence of antibodies through the microscopic agglutination test (MAT) using eighteen serovars of Leptospira commonly found in Malaysia as antigens. It was observed that four out of the five monkeys (80%), rats (9/4) (44%), bats (20/5) (20.8%), squirrels 4/4 (100%) and mongoose (1) (100%) reacted against one or more serovars of Leptospira. In this study antibody of five serovars of Leptospira interrrogans Copenheni, Leptospira interrrogans Lai, Leptospira interrrogans Pomona, Leptospira interrrogans Pyrogenes, Lepto 175* were detected. Serovars Copenhegeni, Lai, Pomona and Pyrogenes were considered pathogenic for different mammals including human beings. No information about serovars lepto 175 and further studies going on. This is providing information on the possible zoonotic importance of mammalian species in maintaining this disease in Sarawak. The transmission of leptospires in rats reported several incidents and between primates, bats, squirrels, mongoose and human is not reported elsewhere but this could create new reservoir and transmission routes and may affect the tourism, conservation effort and public health

Disaster Resilience Education and Research Roadmap for Europe 2030 : ANDROID Report

A disaster resilience education and research roadmap for Europe 2030 has been launched. This roadmap represents an important output of the ANDROID disaster resilience network, bringing together existing literature in the field, as well as the results of various analysis and study projects undertaken by project partners.The roadmap sets out five key challenges and opportunities in moving from 2015 to 2030 and aimed at addressing the challenges of the recently announced Sendai Framework for Disaster Risk Reduction 2015-2030. This roadmap was developed as part of the ANDROID Disaster Resilience Network, led by Professor Richard Haigh of the Global Disaster Resilience Centre (www.hud.ac.uk/gdrc ) at the School of Art, Design and Architecture at the University of Huddersfield, UK. The ANDROID consortium of applied, human, social and natural scientists, supported by international organisations and a stakeholder board, worked together to map the field in disaster resilience education, pool their results and findings, develop interdisciplinary explanations, develop capacity, move forward innovative education agendas, discuss methods, and inform policy development. Further information on ANDROID Disaster Resilience network is available at: http://www.disaster-resilience.netAn ANDROID Disaster Resilience Network ReportANDROI

Serological and molecular detection of Leptospira spp. from small wild mammals captured in Sarawak, Malaysia

Aims: Leptospirosis is endemic to tropical regions of the world and is re-emerging as a new danger to public health in Southeast Asia, including Malaysia. The purpose of this particular study was to determine the common leptospiral serovars present in small wild mammals living around wildlife reserves and disturbed forest habitats and human communities. Methodology and results: The samples of blood and kidneys of small rodents, bats and squirrels were analyzed. Antibodies to different serovars of leptospires were detected in 73 of 155 wild small mammals captured (47.0%: 95% CI 39.0-55.3%). The seroprevalence for rats (57.9%; 95% CI 44.1-70.9) was slightly higher than that for squirrels (42.9%; 95% CI 24.5-62.8) and bats (40%; 95% CI 28.5-52.4). Seropositive animals were detected in all 5 localities sampled. Antibodies to serovar Lepto 175 Sarawak were detected in 30 (24.7%) rats, 11 (9.0%) squirrels and 27 (52.9%) bats. Of 155 kidney samples from individual animals only 17 were positive for Leptospira on a molecular study (10.97%, 95% CI 6.5-17). The majority of the positive results were from plantain squirrels (53%; 95% CI 27.8, 77), Müller's rat (35%; 95% CI 14.2, 61.7) and brown spiny rats (12%; 95% CI 1.5, 36.4). Conclusion, significance and impact of study: This particular study should generate concerns and lead to the health authorities expanding disease control measures in the region as there are significant levels of human activity at all five locations where the animals were sampled. The pathogenesis of serovar Lepto 175 Sarawak also needs to be monitored closely, considering its similarities to the pathogenic Leptospira wolffii

Leptospiral agglutinins in captive and free ranging non-human primates in Sarawak, Malaysia

Aim:The proposed study was carried out to determine the extent of exposure to leptospirosis in non-human primates. Materials and Methods:Trapping of non-human primates was carried out opportunistically around the Bako National Park and the Matang Wildlife Center in the vicinity of human settlements and tourism areas of Sarawak. Blood samples were obtained from the saphenous vein to determine the presence of antibodies by the MicroscopicAgglutination Test (MAT) to 17 serovars of commonly found in Malaysia. Results:Trapping of non-human primates was carried out opportunistically around the Bako National Park and the Matang Wildlife Center in the vicinity of human settlements and tourism areas of Sarawak. Blood samples were obtained from the saphenous vein to determine the presence of antibodies by the MicroscopicAgglutination Test (MAT) to 17 serovars of commonly found in Malaysia. This study reports the screening of twelve primates (eight captive and four free ranging) for leptospirosis. Eight of the 12 monkeys (66.6%; 95% CI 34.9-90.1) reacted against one or two serovars of (Lai and Lepto175). Then serovar Lai is considered pathogenic for different mammals, including humans. Lepto 175 has been identified as an intermediate strain and further studies are being undertaken on this serovar. Conclusion: These results are important as primates may act as reservoirs of spp. for humans, which may potentially affect tourism (economic loss), conservation efforts and public health

Leptospiral agglutinins in captive and free ranging non-human primates in Sarawak, Malaysia

Aim:The proposed study was carried out to determine the extent of exposure to leptospirosis in non-human primates. Materials and Methods:Trapping of non-human primates was carried out opportunistically around the Bako National Park and the Matang Wildlife Center in the vicinity of human settlements and tourism areas of Sarawak. Blood samples were obtained from the saphenous vein to determine the presence of antibodies by the MicroscopicAgglutination Test (MAT) to 17 serovars of commonly found in Malaysia. Results:Trapping of non-human primates was carried out opportunistically around the Bako National Park and the Matang Wildlife Center in the vicinity of human settlements and tourism areas of Sarawak. Blood samples were obtained from the saphenous vein to determine the presence of antibodies by the MicroscopicAgglutination Test (MAT) to 17 serovars of commonly found in Malaysia. This study reports the screening of twelve primates (eight captive and four free ranging) for leptospirosis. Eight of the 12 monkeys (66.6%; 95% CI 34.9-90.1) reacted against one or two serovars of (Lai and Lepto175). Then serovar Lai is considered pathogenic for different mammals, including humans. Lepto 175 has been identified as an intermediate strain and further studies are being undertaken on this serovar. Conclusion: These results are important as primates may act as reservoirs of spp. for humans, which may potentially affect tourism (economic loss), conservation efforts and public health

Leptospirosis, an emerging zoonotic disease in Malaysia

Leptospirosis is an endemic disease in Malaysia and recently has received increasing attention mainly due to several recent incidents that have resulted in human mortality which have alarmed health professionals in Malaysia. The increasing incidence of leptospirosis in forested regions is associated with the bacteria infecting small wild mammals other than rats. Infection in wildlife could result in the introduction of new serovars to humans and domesticated animals. More research on leptospirosis and the screening of wildlife and humans near wildlife habitats is required to have a better understanding of the involvement of wildlife in the disease