222 research outputs found
Garlic (Allium spp.) viruses: detection, distribution and remediation attempts in a European garlic collection
Garlic is an important vegetable crop in numerous countries used as food and natural based medicine. Similar to the majority of vegetatively propagated plants, garlic may be affected by several viruses that can cause severe crop losses. The present study aimed to screen 105 garlic accessions (mother plants) from 5 European countries (Germany, Czech Republic, Poland, Italy, and France) for possible presence of Onion yellow dwarf virus (OYDV), Leek yellow stripe virus (LYSV), Garlic common latent virus (GCLV) and Shallot latent virus (SLV). The occurrence of three Allexiviruses (GarV-A, GarV-B and GarV-C) in mixed assays was also investigated. Meristem-tip culture assays were performed in order to attempt eradication of the studied viruses. Garlic viruses identification was made by ELISA and RT-PCR. ELISA outcomes showed that all 105 garlic accessions were infected by different virus combinations. The OYDV and LYSV were identified, by ELISA, in all countries at 96% and 88,6% respectively and by RT-PCR at 99% and 96%. Furthermore, GCLV and SLV were detected by ELISA in about 88% and by RT-PCR at 89% and 90%, respectively with the exception of the studied Allexiviruses which were not amplified by RT-PCR with ALLEX1/ALLEX2 primers. Smaller meristem size (0,3-1,5 mm) led to better virus elimination efficiency (29%) compared to 8% obtained for the larger size (2-2,5 mm). The outcomes were opposite (16% vs. 90%) for plants regeneration. Virus elimination efficiency was linked to the virus type, e.g., OYDV and LYSV were eradicated at 90% while GCLV and Allexiviruses were difficult to eliminate (57,4% and 55,6% of eradication). Given the economic relevance of garlic crops worldwide and the frequently reported incidence of viral infections, it is important to make virusfree germplasm available. Therefore, investigating the garlic germplasm sanitary status and constantly improving it is of crucial importance aiming to increase the overall garlic production
Quality Traits of Some Cauliflower Cultivars Grown in the “Valle dell’Ofanto” Area (Italy) as Affected by Post-Harvest Storage
Some quality characteristics of the “Valle dell’Ofanto” cauliflower, that has been recently appointed the certification of collective brand, were investigated at Gaudiano (41°03’N; 15°42’E, Southern Italy, Basilicata Region). Six white head cauli-flower cultivars, characterized by a different length of the crop cycle (2 early, 2 medium and 2 late), were studied. The above cultivars were transplanted in open field at the middle of August 2004 and harvested from the middle of October 2004 to the end of March 2005. At harvest time, yield traits and head sizes of cauliflowers were measured. Among the qualitative traits, color, weight loss, total soluble solids, nitrate and vitamin C content were assessed on the fresh florets and after a storage period lasting 15 days at 0°C and 95% R.H. The “Valle dell’Ofanto” cauliflower was charac¬terized by a high content in sugars and vitamin C, even if significant differences in some qualitative parameters (e.g., vitamin C and nitrate content) were affected by cultivars and crop cycle length. On the other hand, the storage at controlled tempera¬ture and R.H. did not substantially change the qualitative characteristics of the heads, but caused only a slight increase of dry matter and soluble solids levels, especially in those cultivars more susceptible to weight loss
The linearity response of the Planck-LFI flight model receivers
In this paper we discuss the linearity response of the Planck-LFI receivers,
with particular reference to signal compression measured on the 30 and 44 GHz
channels. In the article we discuss the various sources of compression and
present a model that accurately describes data measured during tests performed
with individual radiomeric chains. After discussing test results we present the
best parameter set representing the receiver response and discuss the impact of
non linearity on in-flight calibration, which is shown to be negligible.Comment: this paper is part of the Prelaunch status LFI papers published on
JINST: http://www.iop.org/EJ/journal/-page=extra.proc5/jinst; This is an
author-created, un-copyedited version of an article accepted for publication
in JINST. IOP Publishing Ltd is not responsible for any errors or omissions
in this version of the manuscript or any version derived from it. The
definitive publisher authenticated version is available online at
10.1088/1748-0221/4/12/T12011
Planck pre-launch status: calibration of the Low Frequency Instrument flight model radiometers
The Low Frequency Instrument (LFI) on-board the ESA Planck satellite carries
eleven radiometer subsystems, called Radiometer Chain Assemblies (RCAs), each
composed of a pair of pseudo-correlation receivers. We describe the on-ground
calibration campaign performed to qualify the flight model RCAs and to measure
their pre-launch performances. Each RCA was calibrated in a dedicated
flight-like cryogenic environment with the radiometer front-end cooled to 20K
and the back-end at 300K, and with an external input load cooled to 4K. A
matched load simulating a blackbody at different temperatures was placed in
front of the sky horn to derive basic radiometer properties such as noise
temperature, gain, and noise performance, e.g. 1/f noise. The spectral response
of each detector was measured as was their susceptibility to thermal variation.
All eleven LFI RCAs were calibrated. Instrumental parameters measured in these
tests, such as noise temperature, bandwidth, radiometer isolation, and
linearity, provide essential inputs to the Planck-LFI data analysis.Comment: 15 pages, 18 figures. Accepted for publication in Astronomy and
Astrophysic
Restauração ecológica com sistemas agroflorestais: como conciliar conservação com produção: opções para Cerrado e Caatinga.
Esta publicação tem como principal objetivo orientar a adoção de sistemas agroflorestais (SAFs) para restauração de áreas degradadas (ou alteradas), de maneira a conciliar conservação ambiental com benefícios sociais e econômicos. Fruto de uma construção coletiva que alia conhecimento técnico e científico com saberes locais e experiências inovadoras, o livro traz uma série de orientações para técnicos, agricultores e formuladores de políticas a respeito de como SAFs podem e devem ser utilizados para restaurar as diversas funções ambientais previstas para áreas de conservação ambiental (Área de Preservação Permanente - APP e Reserva Legal) na nova Lei Florestal.bitstream/item/161912/1/ICRAF-SAFs-Cerrado-e-Caatinga.pdfGuia técnico
Pregnancy outcomes and cytomegalovirus DNAaemia in HIV infected pregnant women with CMV
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