Search results for "VARIATION"

Applying the bootstrap technique for studying soil redistribution by caesium-137 measurements at basin scale

2000

Abstract The use of the bootstrap technique to estimate the reference level of137 Cs in an uneroded site is tested. The analysis is developed using 137Cs measurements made in a small experimental Sicilian basin. In the reference area the 137Cs activity is normally distributed with a known sample mean value, m equal to 94.4 mBq cm−2. The influence of137 Cs reference site sampling was determined generating samples having a fixed size, N and six different values of the sample coefficient of variation, CV, by a Monte Carlo technique. Then, for each size N, the probability distribution of the mean μ of the sequences generated by Monte Carlo technique is defined. The soil redistribution is determ…

Discussion of “Analytical Equation for Variation of Discharge in Drip Irrigation Laterals” by V. Ravikumar, C. R. Ranganathan, and S. Santhana Bosu

2005

The effects of long-term drainage and subsequent restoration on water table level and pore water chemistry in boreal peatlands

2014

Summary Degradation by drainage threatens biodiversity and globally important peatland ecosystem functions such as long-term carbon sequestration in peat. Restoration aims at safeguarding peatland values by recovering natural hydrology. Long-term effects of drainage and subsequent restoration, especially related to within-site variation of water table level and pore water chemistry, are poorly known. We studied hydrological variation at 38 boreal Sphagnum peatland sites (pristine, drained and restored) in Finland. The average water table level was significantly lower at Drained than Pristine sites especially near the ditches. We also observed large pore water chemical differences between Dr…

Factors Affecting Polyphenol Biosynthesis in Wild and Field Grown St. John’s Wort (Hypericum perforatum L. Hypericaceae/Guttiferae)

2009

The increasing diffusion of herbal products is posing new questions: why are products so often different in their composition and efficacy? Which approach is more suitable to increase the biochemical productivity of medicinal plants with large-scale, low-cost solutions? Can the phytochemical profile of a medicinal plant be modulated in order to increase the accumulation of its most valuable constituents? Will polyphenol-rich medicinal crops ever be traded as commodities? Providing a proactive answer to such questions is an extremely hard task, due to the large number of variables involved: intraspecific chemodiversity, plant breeding, ontogenetic stage, post-harvest handling, biotic and abi…

Identification of New Genetic Clusters in Glioblastoma Multiforme: EGFR Status and ADD3 Losses Influence Prognosis

2020

Glioblastoma multiforme (GB) is one of the most aggressive tumors. Despite continuous efforts to improve its clinical management, there is still no strategy to avoid a rapid and fatal outcome. EGFR amplification is the most characteristic alteration of these tumors. Although effective therapy against it has not yet been found in GB, it may be central to classifying patients. We investigated somatic-copy number alterations (SCNA) by multiplex ligation-dependent probe amplification in a series of 137 GB, together with the detection of EGFRvIII and FISH analysis for EGFR amplification. Publicly available data from 604 patients were used as a validation cohort. We found statistical associations…

Iberian Wolf Howls: Acoustic Structure, Individual Variation, and a Comparison with North American Populations

2007

We present a detailed description of the acoustic structure of howls emitted by Iberian wolves and a comparison with published descriptions of North American wolf howls. We recorded and analyzed 176 howls emitted by 11 wolves held in captivity in social groups of 1–5 individuals. Our sample included solo howls as well as howls included in choruses. Iberian wolf howls are long (1.1- to 12.8-s) harmonic sounds, with a mean fundamental frequency between 270 and 720 Hz. Our results revealed striking similarities between Iberian and North American wolf howls in all variables analyzed except for the number of discontinuities in the frequency of the howl, which was lower for Iberian wolves. Using …

Diagnostic performance and reproducibility of T2w based and diffusion weighted imaging (DWI) based PI-RADSv2 lexicon descriptors for prostate MRI.

2017

To examine the diagnostic performance of PI-RADSv2 T2w and diffusion weighted imaging (DWI) based lexicon descriptors, inter-observer agreement for descriptor assignment and diagnostic accuracy of the PI-RADSv2 assessment categories for multiparametric prostate MRI.176 lesions in 79 consecutive patients are analyzed, lesions are histopathologically verified by MRI-ultrasound fusion biopsy. All lesions are rated according to the PI-RADSv2 lexicon, descriptors for T2w and DWI sequences and resulting assessment categories are assigned by two independent blinded radiologists. We perform receiver-operating-characteristic analysis using the assessment categories. To analyze inter-observer agreeme…

Author response: Phylogenetic variation in cortical layer II immature neuron reservoir of mammals

2020

C4 DNA RFLP reference typing report.

1990

One hundred and three individual DNA samples (including 23 families) were studied at the gene level during the reference typing of the fourth component of human complement at the VIth Complement Genetics Workshop in Mainz (1989). All samples were analyzed with the restriction enzyme Taq I and with two DNA probes recognizing the 5' ends of both C4 genes and the two adjacent 21-hydroxylase genes. This RFLP is informative for the number of C4 genes as well as for their respective gene size. We found a high degree of variation regarding the number of C4 genes, i.e. haplotypes with 1-3 structural C4 genes of 16 or 22 kb size. By correlating these haplotypes to the complotypes obtained by protein…

Inter-observer variability of central corneal thickness measurements using non-contact specular microscopy after laser in situ keratomileusis.

2003

BACKGROUND The aim of this study was to investigate the inter-observer variability of central corneal thickness measurements carried out with a non-contact specular microscope in patients who had undergone myopic laser in situ keratomileusis. METHODS Twenty-six eyes of 26 subjects who had undergone myopic laser in situ keratomileusis were studied with the Topcon SP-2000P non-contact specular microscope (Topcon Corp, Tokyo, Japan). The mean of three consecutive measurements of the central corneal thickness was recorded by two investigators prior to and one month after myopic laser in situ keratomileusis. Results obtained by each of the two physicians were compared. RESULTS Prior to surgery t…