782 research outputs found
Radiometric Estimation of Tropospheric Attenuation: A Mixed Physically Based/Machine Learning Approach
A mixed physically based/machine learning (ML) approach to measure tropospheric attenuation A in all-weather conditions by means of microwave radiometers (MWRs) is proposed. The key idea is to combine the advantages originating from the accurate radiometric A retrievals, provided by the well-established Cosmic background (CB) approach in clear-sky conditions, with the benefits coming from ML techniques. The latter aim at estimating A in rainy situations through a simplified approach able to overcome the issues posed by more complex techniques such as the standard solution of the radiative transfer equation or the Sun tracking (ST) microwave technique. To this aim, an artificial neural network (ANN) is devised to turn the antenna noise temperatures measured by a four-channel MWR (from Ka- to W-band) into tropospheric attenuation at the frequencies of the radiometric channels, namely 23.8, 31.4, 72.5, and 82.5 GHz. The network is properly trained and tested by taking advantage of the concurrent CB and ST measurements collected by the RpG radiometer deployed at Politecnico di Milano, Milan, Italy, under the ESA-funded WRAD project. The proposed approach to retrieve the tropospheric attenuation is intended to overcome the limits associated both with the ST technique (only measurements during the day, link elevation strictly bound to the Sun ecliptic) and to the CB one (unreliable measurements in rainy conditions)
Heritability of teat condition in italian holstein friesian and its relationship with milk production and somatic cell score
Comparasion between European elite senior and junior female table tennis players
The aim of the study was to compare elite junior and senior women table tennis players,
using three parameters of the table tennis: rally length, serve and receive analysis. Twentyfive junior and twenty-five elite senior matches were analysed (total: 263 sets and 4958
points) between players ranked in Top 25 in ETTU rankings in the last two years. All the
athletes used an offensive style of play. The results of non-parametric Mann-Whitney U Test,
showed a significantly higher rally length in senior compared to junior category (4.46 vs.
3.93). Moreover, the results of Pearson’s Chi-square tests show an association between the
age categories and selected parameters (laterality, technique and placement) for both serve
and receive. Different behavior between the two categories was noted. The senior players
used more the flip technique (22.2 % vs 14.7 %) and short push to return the services of the
opponents (32.5 % vs 26.0 %). These results provide useful information to analyze junior
players’ behavior compared to the senior players in order to plan specific training sessions.
It can be also useful to identify some parameters as predictors of the future success for
junior players
Development of sentinel node localization and ROLL in breast cancer in Europe
The concept of a precise region in which to find the lymph nodes that drain the lymph directly from the primary tumor site can be traced back to a century ago to the observations of Jamieson and Dobson who described how cancer cells spread from cancer of the stomach in a single lymph node, which they called the â\u80\u9cprimary glandâ\u80\u9d. However, Cabanas was the first in 1977 to realize the importance of this concept in clinical studies following lymphography performed in patients with penile cancer. Thanks to Mortonâ\u80\u99s studies on melanoma in 1992, we began to understand the potential impact of the sentinel lymph node (SN) on the surgical treatment of this type of cancer. The use of a vital dye (blue dye) administered subdermally in the region surrounding the melanoma lesion led to the identification of the sentinel node, and the vital dye technique was subsequently applied to other types of solid tumors, e.g. breast, vulva. However, difficulties in using this technique in anatomical regions with deep lymphatic vessels, e.g. axilla, led to the development of lymphoscintigraphy, started by Alex and Krag in 1993 on melanoma and breast cancer and optimized by our group at European Institute of Oncology (IEO) in Milan in 1996. Today, lymphoscintigraphy is still considered as the most reliable method for the detection of the SN. In 1996, a new method for the localization of non-palpable breast lesion called radioguided occult lesion localization (ROLL) was also developed at IEO. Retrospective and prospective studies have since shown that the ROLL procedure permits the easy and accurate surgical removal of non-palpable breast lesions, overcoming the limitations of previous techniques such as the wire-guided localization. The purpose of this paper is to describe the evolution of SN biopsy and radioguided surgery in the management of breast cancer. We also include a review of the literature on the clinical scenarios in which SN biopsy in breast cancer is currently used, with particular reference to controversies and future prospects
Fine mapping of loci on BTA8 associated to antibody response to Mycobacterium avium paratuberculosis in cattle
Paratuberculosis (ParaTB) or Johne's disease, caused by Mycobacterium avium subspecies paratuberculosis commonly known as MAP in cattle, is a chronic gastroenteritis characterized by diarrhoea, decreased milk production and ultimately death. MAP is responsible for huge economic losses, particularly in dairy cattle herds. Susceptibility to MAP infection has been found to be heritable with heritability estimates ranging from 0.06 to 0.102. The definition of an infected animal can be based either on the presence of anti-MAP antibodies in the serum, or by direct demonstration of MAP in tissue or faeces by culture or PCR. Several studies have addressed the identification of genetic loci associated with MAP susceptibility. The objective of this study was to refine a locus associated with antibody response to Mycobacterium avium paratuberculosi (MAP). Using a genome- wide association analysis, a single nucleotide polymorphism on Bos taurus autosome BTA8 namely the SNP rs43161947 at posi- tion 35398490 with a p-value of 7.02 e-05, has previously been identified by the authors as associated with MAP infection. Fine mapping of the region was conducted with 100 single nucleotide polymorphisms spanning a region between BTA8: 34422912 and BTA8: 364553881 covering 2 Mega bases (Mb) designed in to cover 1 Mb ahead and after the SNP identified on BTA8. The 2 Mb region on BTA8 was evaluated within a group of 966 Holstein cows collected from routine ParaTB screening in the province of Lodi in Italy, in an area with a high prevalence of ParaTB. Animals were defined as ParaTB positive based on the detection of serum antibodies produced in response to MAP infection using the ID-screen\uae ELISA test (ID VET Montpellier, France). Of the 966 samples, 483 were MAP antibody positive (cases) and 483 MAP antibody negative (MAP negative controls). All animals were female, and cases and MAP negative controls were from the same farm tested on the same day.Using a single marker associ- ation analysis, conducted within the R statistical environment, we identified 3 different QTLs within the 2 Mega base region, under the main QTL on BTA8 associated with antibody response to MAP, in position 34.700.000, 35.800.000 and 36.400.000 bp. This reveals the complexity of the genetic architecture of thetrait and confirms the need to further explore the genome with fine mapping approaches, or by the use of whole genome sequencing to investigate complex traits, such as disease resistance
Genomic and transcriptomic comparison between Staphylococcus aureus strains associated with high and low within herd prevalence of intra-mammary infection
Background: Staphylococcus aureus (Staph. aureus) is one of the major pathogens causing mastitis in dairy ruminants worldwide. The chronic nature of Staph. aureus infection enhances the contagiousness risk and diffusion in herds. In order to identify the factors involved in intra-mammary infection (IMI) and diffusion in dairy cows, we investigated the molecular characteristics of two groups of Staph. aureus strains belonging to ST8 and ST398, differing in clinical properties, through comparison of whole genome and whole transcriptome sequencing.
Results: The two groups of strains, one originated from high IMI prevalence herds and the other from low IMI prevalence herds, present a peculiar set of genes and polymorphisms related to phenotypic features, such as bacterial invasion of mammary epithelial cells and host adaptation. Transcriptomic analysis supports the high propensity of ST8 strain to chronicity of infection and to a higher potential cytotoxicity.
Conclusions: Our data are consistent with the invasiveness and host adaptation feature for the strains GTB/ST8 associated to high within-herd prevalence of mastitis. Variation in genes coding for surface exposed proteins and those associated to virulence and defence could constitute good targets for further research
Genome sequencing of Prototheca zopfii genotypes 1 and 2 provides evidence of a severe reduction in organellar genomes
Abstract Prototheca zopfii (P. zopfii, class Trebouxiophyceae, order Chlorellales, family Chlorellaceae), a non-photosynthetic predominantly free-living unicellular alga, is one of the few pathogens belonging to the plant kingdom. This alga can affect many vertebrate hosts, sustaining systemic infections and diseases such as mastitis in cows. The aim of our work was to sequence and assemble the P. zopfii genotype 1 and genotype 2 mitochondrial and plastid genomes. Remarkably, the P. zopfii mitochondrial (38 Kb) and plastid (28 Kb) genomes are models of compaction and the smallest known in the Trebouxiophyceae. As expected, the P. zopfii genotype 1 and 2 plastid genomes lack all the genes involved in photosynthesis, but, surprisingly, they also lack those coding for RNA polymerases. Our results showed that plastid genes are actively transcribed in P. zopfii, which suggests that the missing RNA polymerases are substituted by nuclear-encoded paralogs. The simplified architecture and highly-reduced gene complement of the P. zopfii mitochondrial and plastid genomes are closer to those of P. stagnora and the achlorophyllous obligate parasite Helicosporidium than to those of P. wickerhamii or P. cutis. This similarity is also supported by maximum likelihood phylogenetic analyses inferences. Overall, the P. zopfii sequences reported here, which include nuclear genome drafts for both genotypes, will help provide both a deeper understanding of the evolution of Prototheca spp. and insights into the corresponding host/pathogen interactions
Simultaneous identification by multiplex PCR of major Prototheca spp. isolated from bovine and buffalo intramammary infection and bulk tank
Bovine mastitis caused by Prototheca spp. infection is increasing worldwide, therefore becoming more relevant to the dairy industry. Almost all Prototheca isolates from bovine mammary protothecosis came from P. zopfii genotype 2, with a lower prevalence of infection due to P. blaschkeae and rarely to P. wickerhamii. In this study, we report the development of two multiplex PCR assays able to discriminate among the three species responsible for bovine intramammary infection (IMI). Our assay is based on the specific amplification of new DNA target from mitochondria and chloroplasts partial sequences, of different Prototheca isolates. Both methods were set up using reference strains belonging to all Prototheca species and validated by the analysis of 93 isolates from bovine and buffalo IMI and bulk tank milk samples. The investigation involves 70 isolates from North, 13 from Central and 10 from South Italian regions. Isolates from bovine were most commonly identified as P. zopfii genotype 2, and only in one case as P. blaschkeae, whereas isolates from buffaloes belonged both to P. zopfii genotype 2 and P. wickerhamii. These findings proved the suitability of our multiplex PCRs as a rapid test to discriminate among pathogenic Prototheca strains
Prognostic factors in metaplastic carcinoma of the breast: A multi-institutional study
Background: Metaplastic breast carcinoma (MBC) is a rare type of breast cancer that has basal-like characteristics and is perceived to have poorer prognosis when compared with conventional no specific type/ductal carcinomas (ductal/NST). However, current data on MBC are largely derived from small case series or population-based reports. This study aimed to assess the clinicopathological features and outcome of MBC identified through an international multicentre collaboration. Methods: A large international multicentre series of MBC (no=405) with histological confirmation and follow-up information has been included in this study. The prognostic value of different variables and outcome has been assessed and compared with grade, nodal status and ER/HER2 receptor-matched ductal/NST breast carcinoma. Results: The outcome of MBC diagnosed in Asian countries was more favourable than those in Western countries. The outcome of MBC is not different from matched ductal/NST carcinoma but the performance of the established prognostic variables in MBC is different. Lymph node stage, lymphovascular invasion and histologic subtype are associated with outcome but tumour size and grade are not. Chemotherapy was associated with longer survival, although this effect was limited to early-stage disease. In this study no association between radiotherapy and outcome was identified. Multivariate analysis of MBC shows that histologic subtype is an independent prognostic feature. Conclusions: This study suggests that MBC is a heterogeneous disease. Although the outcome of MBC is not different to matched conventional ductal/NST breast carcinoma, its behaviour is dependent on the particular subtype with spindle cell carcinoma in particular has an aggressive biological behaviour. Management of patients with MBC should be based on validated prognostic variables
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