Radar rainfall image repair techniques

International audienceThere are various quality problems associated with radar rainfall data viewed in images that include ground clutter, beam blocking and anomalous propagation, to name a few. To obtain the best rainfall estimate possible, techniques for removing ground clutter (non-meteorological echoes that influence radar data quality) on 2-D radar rainfall image data sets are presented here. These techniques concentrate on repairing the images in both a computationally fast and accurate manner, and are nearest neighbour techniques of two sub-types: Individual Target and Border Tracing. The contaminated data is estimated through Kriging, considered the optimal technique for the spatial interpolation of Gaussian data, where the "screening effect" that occurs with the Kriging weighting distribution around target points is exploited to ensure computational efficiency. Matrix rank reduction techniques in combination with Singular Value Decomposition (SVD) are also suggested for finding an efficient solution to the Kriging Equations which can cope with near singular systems. Rainfall estimation at ground level from radar rainfall volume scan data is of interest and importance in earth bound applications such as hydrology and agriculture. As an extension of the above, Ordinary Kriging is applied to three-dimensional radar rainfall data to estimate rainfall rate at ground level. Keywords: ground clutter, data infilling, Ordinary Kriging, nearest neighbours, Singular Value Decomposition, border tracing, computation time, ground level rainfall estimatio

Radar rainfall image repair techniques

There are various quality problems associated with radar rainfall data viewed in images that include ground clutter, beam blocking and anomalous propagation, to name a few. To obtain the best rainfall estimate possible, techniques for removing ground clutter (non-meteorological echoes that influence radar data quality) on 2-D radar rainfall image data sets are presented here. These techniques concentrate on repairing the images in both a computationally fast and accurate manner, and are nearest neighbour techniques of two sub-types: Individual Target and Border Tracing. The contaminated data is estimated through Kriging, considered the optimal technique for the spatial interpolation of Gaussian data, where the 'screening effect' that occurs with the Kriging weighting distribution around target points is exploited to ensure computational efficiency. Matrix rank reduction techniques in combination with Singular Value Decomposition (SVD) are also suggested for finding an efficient solution to the Kriging Equations which can cope with near singular systems. Rainfall estimation at ground level from radar rainfall volume scan data is of interest and importance in earth bound applications such as hydrology and agriculture. As an extension of the above, Ordinary Kriging is applied to three-dimensional radar rainfall data to estimate rainfall rate at ground level.</p> <p style='line-height: 20px;'><b>Keywords: </b>ground clutter, data infilling, Ordinary Kriging, nearest neighbours, Singular Value Decomposition, border tracing, computation time, ground level rainfall estimatio

Trauma systems in Kenya: A qualitative analysis at the district level

© The Author(s) 2015. Injury is a leading cause of death and disability in low- and middle-income countries. Kenya has a particularly high burden of injuries, accounting for 88.4 deaths per 100,000 population. Despite recent attempts to prioritize injury prevention in Kenya, trauma care systems have not been assessed. We assessed perceptions of formal and informal district-level trauma systems through 25 qualitative semi-structured interviews and 16 focus group discussions with Ministry of Health officials, district hospital administrators, health care providers, police, and community members. We used the principles of theoretical analysis to identify common themes of prehospital and hospital trauma care. We found prehospital care relied primarily on good Samaritans and police. We described hospital care in terms of human resources, infrastructure, and definitive care. The interviewers repeatedly emphasized the lack of hospital infrastructure. We showed the need to develop prehospital care systems and strengthen hospital trauma care services

Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis

The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeutic strategy for AD

Can a tailored exercise and home hazard reduction program reduce the rate of falls in community dwelling older people with cognitive impairment: protocol paper for the i-FOCIS randomised controlled trial

The rate of falls in community dwelling older people with cognitive impairment (CI) is twice that of a cognitively intact population, with almost two thirds of people with CI falling annually. Studies indicate that exercise involving balance and/or a home hazard reduction program are effective in preventing falls in cognitively intact older people. However the potential benefit of these interventions in reducing falls in people with CI has not been established. This randomised controlled trial will determine whether a tailored exercise and home hazard reduction program can reduce the rate of falls in community dwelling older people with CI. We will determine whether the intervention has beneficial effects on a range of physical and psychological outcome measures as well as quality of life of participants and their carers. A health economic analysis examining the cost and potential benefits of the program will also be undertaken