A comparison of two radio propagation channel impulse responsedetermination techniques

A comparison of two radio propagation channel impulse response determination techniques is described. Presented are typical impulse response and transfer functions obtained from each measurement system. Also included for comparison are average impulse response envelopes and cumulative probability distributions for the RMS delay spread of static indoor radio channels calculated from 120 measurements using each system. The comparisons show good agreement between results     

Batch accuracy of on-line fat determination

A new method for determination of the fat content of large meat batches without sampling is presented. It is based on dual-energy X-ray (DXR) scanning of meat trimmings prior to mixing, in order to determine the exact fat content of the resulting meat batch. Twenty-seven samples of three types of pork trimmings with a fat content ranging from 24 to 63% were collected and combined into batch sizes of 27-241 kg. At small batch sizes (27 kg) the nature of the measurement error is mainly random, resulting in a prediction error (root mean square error of prediction) of 0.57% against the reference method. At a batch size of 241 kg the error was reduced to 0.34%. The DXR method determines the fat content of all meat in a batch without any sampling required, thus reducing the sampling error to a minimum. This is essential, as the results show that the sampling error is large: when 27-kg samples were homogenized and measured by the reference method, the standard deviation of high-fat samples was 4.7%.     

Primary Sj?gren's syndrome and glomerulonephritis

HISTORY AND CLINICAL FINDINGS: An 82-year-old woman with hypertension for 20 years developed a nephrotic syndrome with severe oedema followed by acute oliguric renal failure after a bout of bronchitis and a gastrointestinal infection. She also complained of xerostomia and dry eyes of recent onset. INVESTIGATIONS: Biochemical tests showed a serum creatinine level of 6.1 mg/dl, a 1:5120 antinuclear antibody (ANA) titre, and positive values for Ro(SS-A) and La(SS-B) antibodies. HLA-DR typing demonstrated HLA-DR3 (HLA-DRB1*0301) and DR13 (HLA-DRB1*13) antigens. Renal biopsy revealed minimal glomerular lesions with focal and segmental glomerulo-sclerosis as well as (hypertension-induced) benign nephrosclerosis and focal tubular atrophy with interstitial fibrosis. TREATMENT AND COURSE: After two hemofiltrations and concomitant administration of 100 mg prednisone renal function quickly improved and the proteinuria fell to 1 g/dl. At the same time the xerostomia improved. The nephrotic syndrome recurred 7 months later after the prednisone dose had been reduced to 10 mg/d, but after the dose had been raised to 50 mg/d and cyclosporin A (150 mg/d) had been added a lasting remission occurred and renal function became stable though impaired. CONCLUSION: The relatively rare association of glomerular disease (here focal segmental glomerulosclerosis) with Sj?gren's syndrome can, as in this case, be triggered by a viral infection. A genetic predisposition for Sj?gren's syndrome is suggested by the demonstration of HLA-DR3 alleles. Administration of steroids is indicated for the treatment of the nephrotic syndrome and, in case of recurrence, can be combined with cyclosporin A. Both drugs also influence the symptoms of Sj?gren's syndrome.     

Statistical modeling and simulation of the RMS delay spread ofindoor radio propagation channels

Using a large empirical data base of 12000 impulse response estimates collected in two office buildings the root mean square (rms) delay spread for the individual impulse responses have been calculated and analyzed. Statistical modeling of τ_rms includes investigation of the local and global distributions, correlations in space, dependence on transmitter-receiver antenna separation, correlations with large scale path losses, and dependence on the dynamic range of measurements. Using the results of the statistical analysis, a simulation model capable of generating a set of τ_rms values for spatially-adjacent points has been developed     

Volatile Organic Compound Mediated Interactions at the Plant-Microbe Interface

Microorganisms colonize the surfaces of plant roots, leaves, and flowers known as the rhizosphere, phyllosphere, and anthosphere. These spheres differ largely in a number of factors that may determine the ability of microbes to establish themselves and to grow in these habitats. In this article, we focus on volatile organic compounds (VOCs) emitted by plants, and we discuss their effects on microbial colonizers, with an emphasis on bacteria. We present examples of how growth-inhibiting properties and mechanisms of VOCs such as terpenoids, benzenoid compounds, aliphatics, and sulfur containing compounds prevent bacterial colonization at different spheres, in antagonism with their role as carbon-sources that support the growth of different bacterial taxa. The notion that VOCs represent important factors that define bacterial niches is further supported by results for representatives of two bacterial genera that occupy strongly diverging niches based on scent emissions of different plant species and organs. Bacteria are known to either positively or negatively affect plant fitness and to interfere with plant-animal interactions. Thus, bacteria and other microbes may select for VOCs, enabling plants to control microbial colonizers on their surfaces, thereby promoting the growth of mutualists and preventing the establishment of detrimental microbes.