Search results for "statistical analysi"

Gravitational-wave Detection and Parameter Estimation for Accreting Black-hole Binaries and Their Electromagnetic Counterpart

2020

We study the impact of gas accretion on the orbital evolution of black-hole binaries initially at large separation in the band of the planned Laser Interferometer Space Antenna (LISA). We focus on two sources: (i)~stellar-origin black-hole binaries~(SOBHBs) that can migrate from the LISA band to the band of ground-based gravitational-wave observatories within weeks/months; and (ii) intermediate-mass black-hole binaries~(IMBHBs) in the LISA band only. Because of the large number of observable gravitational-wave cycles, the phase evolution of these systems needs to be modeled to great accuracy to avoid biasing the estimation of the source parameters. Accretion affects the gravitational-wave p…

Modified climate with long term memory in tree ring proxies

2015

ABSTRACT : A contribution to the PAGES Asia2k Working Group. ABSTRACT: Long term memory (LTM) scaling behavior in worldwide tree ring proxies and subsequent climate reconstructions is analyzed for and compared with the memory structure inherent to instrumental temperature and precipitation data. Detrended fluctuation analysis is employed to detect LTM and its scaling exponent a is used to evaluate LTM. The results show that temperature and precipitation reconstructions based on ring width measurements (mean \alpha =0.8) contain more memory than records based on maximum latewood density (mean \alpha =0.7). Both exceed the memory inherent to regional instrumental data (\alpha =0.6 for tempera…

Regional provenance of dolerite prehistoric objects through mineral analysis

2016

Abstract A methodology based on the mineral analysis determination has been developed to identify the origin of dolerite stone outcrops collected to fabricate lithic objects during the Prehistoric period. The method is based on the use of inductively coupled plasma mass spectrometry (ICP-MS) to analyse rare earth elements (REE) and trace elements. Additionally a no destructive geochemical analysis based on X-ray fluorescence (XRF) was employed for major elements analysis. The aforementioned methodologies were applied to samples from different archaeological fields or natural outcrops located in the Mediterranean area of Spain, between Valencia and Alicante. Principal component analysis (PCA…

Statistical modelling and RCS detrending methods provide similar estimates of long-term trend in radial growth of common beech in north-eastern France

2011

International audience; Dendrochronological methods have greatly contributed to the documentation of past long-term trends in forest growth. These methods primarily focus on the high-frequency signals of tree ring chronologies. They require the removal of the ageing trend in tree growth, known as 'standardisation' or 'detrending', as a prerequisite to the estimation of such trends. Because the approach is sequential, it may however absorb part of the low-frequency historical signal. In this study, we investigate the effect of a sequential and a simultaneous estimation of the ageing trend on the chronology of growth. We formerly developed a method to estimate historical changes in growth, in…

Estimating the abundance of burrow-nesting species through the statistical analysis of combined playback and visual surveys

2016

Reducing sample size in experiments with animals: historical controls and related strategies

2015

Reducing the number of animal subjects used in biomedical experiments is desirable for ethical and practical reasons. Previous reviews of the benefits of reducing sample sizes have focused on improving experimental designs and methods of statistical analysis, but reducing the size of control groups has been considered rarely. We discuss how the number of current control animals can be reduced, without loss of statistical power, by incorporating information from historical controls, i.e. subjects used as controls in similar previous experiments. Using example data from published reports, we describe how to incorporate information from historical controls under a range of assumptions that mig…

The more the merrier? Scoring, statistics and animal welfare in experimental autoimmune encephalomyelitis.

2016

Experimental autoimmune encephalomyelitis (EAE) is a frequently used animal model for the investigation of autoimmune processes in the central nervous system. As such, EAE is useful for modelling certain aspects of multiple sclerosis, a human autoimmune disease that leads to demyelination and axonal destruction. It is an important tool for investigating pathobiology, identifying drug targets and testing drug candidates. Even though EAE is routinely used in many laboratories and is often part of the routine assessment of knockouts and transgenes, scoring of the disease course has not become standardized in the community, with at least 83 published scoring variants. Varying scales with diffe…

FragClust and TestClust, two informatics tools for chemical structure hierarchical clustering analysis applied to lipidomics. The example of Alzheime…

2016

Lipidomic analysis is able to measure simultaneously thousands of compounds belonging to a few lipid classes. In each lipid class, compounds differ only by the acyl radical, ranging between C10:0 (capric acid) and C24:0 (lignoceric acid). Although some metabolites have a peculiar pathological role, more often compounds belonging to a single lipid class exert the same biological effect. Here, we present a lipidomics workflow that extracts the tandem mass spectrometry data from individual files and uses them to group compounds into structurally homogeneous clusters by chemical structure hierarchical clustering analysis (CHCA). The case-to-control peak area ratios of the metabolites are then a…

Antibacterial Activity of Propolis Extracts from the Central Region of Romania against Neisseria gonorrhoeae

2021

(1) Background: Sexually transmitted infections (STIs) are among the most common infections worldwide, many of these being caused by Neisseria gonorrhoeae (NG). Increased antimicrobial NG resistance has been reported in recent decades, highlighting the need for new sources of natural compounds with valuable antimicrobial activity. This study aims to determine the effect of propolis extracts on NG strains, including antibiotic-resistant strains. (2) Methods: First void urine samples from presumed positive STI subjects were harvested. DNA was extracted, purified, and amplified via PCR for the simultaneous detection of 6 STIs. The presence of the dcmH, gyrA, and parC genes was checked in the D…

Vertical root fracture resistance of simulated immature permanent teeth filled with MTA using different vehicles

2017

Background The aim of the study is to evaluate the resistance vertical root fracture (VRF) of mineral trioxide aggregate (MTA) filled-immature permanent roots by using three different vehicles. Material and Methods Forty-extracted human single-rooted mandibular premolars were selected and the root length was standardized to the length of 9 mm. For simulation of immature tooth apices, peeso reamers were introduced into the root canals and the prepared roots were assigned into three experimental groups according the used vehicle (distilled water-DW, prophylene glycol-PG, chlorhexidine-CHX) and control group (n=10). To simulate a periodontal membrane, the apical 7 mm of all roots was covered w…