558 research outputs found
The contribution of hyperspectral remote sensing to identify vegetation characteristics necessary to assess the fate of Persistent Organic Pollutants (POPs) in the environment
Entrepreneurial intention studies: A hybrid bibliometric method to identify new directions for theory and research
Fragmentation is the main obstacle to scientific progress on entrepreneurial intention. To address this issue, we systematise the current literature with a hybrid bibliometric method that combines co-citation and bibliographic coupling analysis for the first time in entrepreneurial intention studies to show the field's knowledge base and research fronts and to examine how divergent perspectives have challenged the core knowledge of the field. We highlight three recurring dimensions of entrepreneurial intention studies: (1) personal factors, (2) social factors and (3) investigational settings. In addition to introducing new constructs, divergent perspectives have emphasised the interplay between these components and challenged the mechanisms connecting them. Based on these findings, we extend previous classifications in the literature by providing a framework that integrates divergent perspectives with the field's knowledge base, helping establish future research avenues and improving the theorising process of entrepreneurial intention
The contribution of hyperspectral remote sensing to identify vegetation characteristics necessary to assess the fate of Persistent Organic Pollutants (POPs) in the environment
During recent years hyperspectral remote sensing data were successfully used to characterise the state and properties
of vegetation. The information on vegetation cover and status is useful for a range of environmental modelling
studies. Recent works devoted to the understanding of the fate of Persistent Organic Pollutants (POPs) in the environment
showed that forests and vegetation in general act as a «sponge» for chemicals present in air and the intensity
of this «capture» effect depends on some vegetation parameters such as surface area, leaf composition, turnover
etc. In the framework of the DARFEM experiment conducted in late June 2001, different airborne hyperspectral
images were acquired and analysed to derive some vegetation parameters of relevance for multimedia models, such
as the spatial distribution of plant species and their relative foliage biomass. The study area, south west of Milan,
encompasses a range of land cover types typical of Northern Italy, including intensive poplar plantations and natural
broad-leaf forest. An intensive field campaign was accomplished during the aerial survey to collect vegetation
parameters and radiometric measurements. Results obtained from the analysis of hyperspectral images, map of vegetation
species, Leaf Area Index (LAI) and foliage biomass are presented and discussed
Arsenic movement and fractionation in agricultural soils which received wastewater from an adjacent industrial site for 50 years
Arsenic (As) is an element with important environmental and human health implications due to its toxic properties. It is naturally occurring since it is contained in minerals, but it can also be enriched and distributed in the environment by anthropogenic activities. This paper reports on the historic As contamination of agricultural soils in one of the most important national relevance site for contamination in Italy, the so-called SIN Brescia-Caffaro, in the city of Brescia, northern Italy. These agricultural areas received As through the use of irrigation waters from wastewater coming from a factory of As-based pesticides (lead and calcium arsenates, sodium arsenite). Pesticide production started in 1920 and ended in the '70. Concentrations in the areas are generally beyond the legal threshold values for different soil uses and are up to >200 mg/kg. Arsenic contamination was studied to assess the long-time trend and the dynamics related to the vertical movement of As down to 1 m depth and its horizontal diffusion with surface irrigation in the entire field. Arsenic fractionation analysis (solid phase speciation by sequential extraction procedure) was also performed on samples collected from these areas and employed in greenhouse experiments with several plant species to evaluate the long-term contamination and the role of plant species in modifying As availability in soil. The results of this work can help in the evaluation of the conditions controlling the vertical transfer of As towards surface aquifers, the bioaccumulation likelihood in the agricultural food chain and the selection of sustainable remediation techniques such as phytoextraction
A real-time RT-PCR assay for molecular identification and quantitation of feline morbillivirus RNA from biological specimens.
The aim of this study was to develop a real-time RT-PCR to detect and quantitate feline
morbillivirus (FeMV) RNA in biological samples. Primers and probe were targeted on a conserved
region of FeMV P/V/C gene. To validate the assay with field samples, a total number of specimens
of cats have been recruited including 264 urine and blood samples and compared with a generic
RT-PCR targeting the L protein encoding gene of morbilliviruses. In addition, 385 tissue samples
from 35 carcasses of cats have been also employed. RNA titres were low in all tested samples.
Results also indicated the absence of cross-reaction with related morbilliviruses and existing
pathogens of cats. However, in tissues with low levels of FeMV RNA, the presence of viral antigen
was confirmed by immunohistochemistry targeting the N viral protein. This newly described assay
allows for a rapid, accurate and reliable quantitative detection of FeMV RNA that can be applied
for diagnostics and research studies
Morbilliviruses in aquatic mammals: report on round table discussion.
A workshop was organised to ascertain the current situation with regard to morbillivirus infections in aquatic animals. The great interest generated by the discovery of these new virus infections in 1988 has to some extent abated but much high quality research has continued in this field as the workshop showed. There is some serological evidence that the viruses have continued to circulate in most areas since the initial epizootics. As to their origin, it appears that the most likely source of the European seal morbillivirus (PDV-1) is the North Atlantic and Artic seal populations. As to the origin of the Mediterranean dolphin morbillivirus and the morbilliviruses isolated from porpoises, there is serological evidence that the viruses are widespread in many cetacean species in the Atlantic and 93% of long-finned pilot whales (Globicephala melas) which mass stranded between 1982 and 1993 were morbillivirus seropositive. The epizootic in freshwater seals in Lake Baikal was unrelated to events in the European marine mammal populations. The virus which infected these animals (PDV-2) is indistinguishable from canine distemper field strains. Serological and molecular biological studies provided evidence for the presence of the virus in the seals, at least as late as the Summer of 1992 when the animals were last sampled
A lymphofollicular microenvironment is required for pathological prion protein deposition in chronically inflamed tissues from scrapie-affected sheep
In sheep scrapie, pathological prion protein (PrPSc) deposition occurs in the lymphoreticular and central nervous systems. We investigated PrPSc distribution in scrapie- affected sheep showing simultaneous evidence of chronic lymphofollicular, lymphoproliferative/non-lymphofollicular,and/or granulomatous inflammations in their mammary gland, lung, and ileum. To do this, PrPSc detection was carried out via immunohistochemistry and Western Blotting techniques, as well as through inflammatory cell immunophenotyping. Expression studies of gene coding for biological factors modulating the host’s inflammatory response were also carried out. We demonstrated that ectopic PrPSc deposition occurs exclusively in the context of lymphofollicular inflammatory sites, inside newly formed and well-organized lymphoid follicles harboring follicular dendritic cells. On the contrary, no PrPSc deposition was detected in granulomas, even when they were closely located to newly formed lymphoid follicles. A significantly more consistent expression of lymphotoxin α and β mRNA was detected in lymphofollicular inflammation compared to the other two types, with lymphotoxin α and β signaling new lymphoid follicles’ formation and, likely, the occurrence of ectopic PrPSc deposition inside them. Our findings suggest that, in sheep co-affected by scrapie and chronic inflammatory conditions, only newly formed lymphoid follicles provide a suitable micro-environment that supports the scrapie agent’s replication in inflammatory sites, with an increased risk of prion shedding through body secretions/excretions.[...
Dolphin Morbillivirus in a Cuvier’s beaked whale (Ziphius cavirostris), Italy
Dolphin Morbillivirus (DMV) has caused several mortality events in Mediterranean striped (Stenella coeruleoalba) and bottlenose
(Tursiops truncatus) dolphins populations since nineties; in the last 5 years, the virus was reported to infect new hosts in this
basin, such as fin whales (Balaenoptera physalus), sperm whales (Physeter macrocephalus) and even a harbor seal (Phoca vitulina).
Very recently, a calf Cuvier’s beaked whale (Ziphius cavirostris) calf stranded on the Southern Italian coastline with mild
pathological findings suggestive of morbilliviral infection, received the first confirmation of DMV infection in this species by
biomolecular evidences on lung tissue. This new cross species infection report, along with 19% of the cetaceans specimens
examined by the Italian Stranding Network being found positive to DMV, support the hypothesis of an endemic circulation of this
virus among Mediterranean cetaceans
Development and validation of a 20K Single Nucleotide Polymorphism (SNP) whole genome genotyping array for apple (Malus × domestica Borkh)
High-density SNP arrays for genome-wide assessment of allelic variation have made high resolution genetic characterization of crop germplasm feasible. A medium density array for apple, the IRSC 8 K SNP array, has been successfully developed and used for screens of bi-parental populations. However, the number of robust and well-distributed markers contained on this array was not sufficient to perform genome-wide association analyses in wider germplasm sets, or Pedigree-Based Analysis at high precision, because of rapid decay of linkage disequilibrium. We describe the development of an Illumina Infinium array targeting 20 K SNPs. The SNPs were predicted from re-sequencing data derived from the genomes of 13 Malus × domestica apple cultivars and one accession belonging to a crab apple species (M. micromalus). A pipeline for SNP selection was devised that avoided the pitfalls associated with the inclusion of paralogous sequence variants, supported the construction of robust multi-allelic SNP haploblocks and selected up to 11 entries within narrow genomic regions of ±5 kb, termed focal points (FPs). Broad genome coverage was attained by placing FPs at 1 cM intervals on a consensus genetic map, complementing them with FPs to enrich the ends of each of the chromosomes, and by bridging physical intervals greater than 400 Kbps. The selection also included ~3.7 K validated SNPs from the IRSC 8 K array. The array has already been used in other studies where ~15.8 K SNP markers were mapped with an average of ~6.8 K SNPs per full-sib family. The newly developed array with its high density of polymorphic validated SNPs is expected to be of great utility for Pedigree-Based Analysis and Genomic Selection. It will also be a valuable tool to help dissect the genetic mechanisms controlling important fruit quality traits, and to aid the identification of marker-trait associations suitable for the application of Marker Assisted Selection in apple breeding programs
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