4,621 research outputs found
Fruit Flies Provide New Insights in Low-Radiation Background Biology at the INFN Underground Gran Sasso National Laboratory (LNGS)
Deep underground laboratories (DULs) were originally created to host particle, astroparticle or nuclear physics experiments requiring a low-background environment with vastly reduced levels of cosmic-ray particle interference. More recently, the range of science projects requiring an underground experiment site has greatly expanded, thus leading to the recognition of DULs as truly multidisciplinary science sites that host important studies in several fields, including geology, geophysics, climate and environmental sciences, technology/instrumentation development and biology. So far, underground biology experiments are ongoing or planned in a few of the currently operating DULs. Among these DULs is the Gran Sasso National Laboratory (LNGS), where the majority of radiobiological data have been collected. Here we provide a summary of the current scenario of DULs around the world, as well as the specific features of the LNGS and a summary of the results we obtained so far, together with other findings collected in different underground laboratories. In particular, we focus on the recent results from our studies of Drosophila melanogaster, which provide the first evidence of the influence of the radiation environment on life span, fertility and response to genotoxic stress at the organism level. Given the increasing interest in this field and the establishment of new projects, it is possible that in the near future more DULs will serve as sites of radiobiology experiments, thus providing further relevant biological information at extremely low-dose-rate radiation. Underground experiments can be nicely complemented with above-ground studies at increasing dose rate. A systematic study performed in different exposure scenarios provides a potential opportunity to address important radiation protection questions, such as the dose/dose-rate relationship for cancer and non-cancer risk, the possible existence of dose/dose-rate threshold(s) for different biological systems and/or end points and the possible role of radiation quality in triggering the biological response
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The pgip family in soybean and three other legume species: evidence for a birth-and-death model of evolution
Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat (LRR) plant cell wall glycoproteins involved in plant immunity. They are typically encoded by gene families with a small number of gene copies whose evolutionary origin has been poorly investigated. Here we report the complete characterization of the full complement of the pgip family in soybean (Glycine max [L.] Merr.) and the characterization of the genomic region surrounding the pgip family in four legume species. Results: BAC clone and genome sequence analyses showed that the soybean genome contains two pgip loci. Each locus is composed of three clustered genes that are induced following infection with the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary, and remnant sequences of pgip genes. The analyzed homeologous soybean genomic regions (about 126 Kb) that include the pgip loci are strongly conserved and this conservation extends also to the genomes of the legume species Phaseolus vulgaris L., Medicago truncatula Gaertn. and Cicer arietinum L., each containing a single pgip locus. Maximum likelihood-based gene trees suggest that the genes within the pgip clusters have independently undergone tandem duplication in each species. Conclusions: The paleopolyploid soybean genome contains two pgip loci comprised in large and highly conserved duplicated regions, which are also conserved in bean, M. truncatula and C. arietinum. The genomic features of these legume pgip families suggest that the forces driving the evolution of pgip genes follow the birth-and-death model, similar to that proposed for the evolution of resistance (R) genes of NBS-LRR-type
Manual de perdas pós-colheita em frutos e hortaliças.
Produção e perdas de frutos e hortaliças no Brasil. Perdas: definição, tipos e causas. Alguns aspectos envolvidos no controle das perdas: pré-colheita; colheita; pós-colheita; embalagem; transporte; armazenamento. Aspectos de mercado.bitstream/item/33932/1/1997-DOC-0027.pd
Power supply ramping for quasi-static testing of PLLs
An innovative approach for testing PLLs in open loop-mode is presented. The operational method consists of ramping the PLL's power supply by means of a periodic sawtooth signal. The reference and feedback inputs of the PLL in open-loop mode are connected to the clock reference signal or to ground. Then, the corresponding quiescent current, clock output, and oscillator control voltage signatures are monitored and sampled at specific times. When the power supply is swept, all transistors are forced into various regions of operation causing the sensitivity of the faults to the specific stimulus to be magnified. The developed method of structural testing for PLLs yields high fault coverage results making it a potential and attractive technique for production wafer testing
Uso de diferentes fibras de micro-extração em fase sólida para identificação de compostos voláteis em abacaxi cultivar smooth cayenne.
Materiais e métodos; Resultados.bitstream/CTAA-2009-09/8944/1/ct77-2005.pd
Prevalence of Johne\u27s-disease infections in Umbria, Italy
Ukupno 788 uzoraka seruma uzetih od mliječnih goveda u Umbriji, Italija, ispitano je na prisustvo antitijela na Mycobacterium avium subsp. paratuberculosis (MAP) pomoću komercijalnog ELISA testa (imunoenzimski test). Uzorkovane životinje uzgajane su na 19 farmi iz središnjeg dijela pokrajine Umbrije (okruzi Perugia i Assisi). Koristeći graničnu vrijednost za pozitivan test prema preporuci proizvođača, utvrđene su 44 pozitivne životinje (5,6%). Na temelju osjetljivosti i specifičnosti ELISA testa koje navodi proizvođač, izračunato je da je ukupna učestalost bolesti u mliječnih goveda u Umbriji ustvari iznosila 9,7% (granice pouzdanosti 99%, 7,0%, 12,4%).A total of 788 serum samples from dairy cattle in Umbria, Italy, were tested for the presence of antibodies to Mycobacterium avium subspecies paratuberculosis (MAP) using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The sampled animals came from 19 herds representative of the central area of the Umbria County (Perugia and Assisi districts). Using the manufacturers suggested cut-off for a positive test, 44 animals (5.6%) were positive. Using the sensitivity and specificity claimed by the manufacturer of the ELISA kit, the true prevalence in Umbria dairy cattle overall was calculated as 9.7% (99% CI, 7.0%, 12.4%).Insgesamt 788 Serummuster, genommen von Milchrindvieh in Umbria/Italien, wurden auf Anwesenheit von Antikörpern auf Mycobacterium avium subsp. Paratuberculosis (MAP) mit Hilfe von kommerziellem ELISA Test (Immunoenzymtest) geprüft. Die gemusterten Tiere wurden auf 19 Farmen in mittlerem Teil der Provinz Umbria (Kreise Perugia und Assisi) gezüchtet. Nach Anweisung des Herstellers benutzte man den Grenzwert für positiven Test, so wurden 44 positive Tiere (5,6 %) festgestellt. Auf Grund der Empfindlichkeit und der Spezifität des ELISA Testes, die der Hersteller anführt, wurde ausgerechnet, dass die gesamte Häufigkeit der Krankheit bei Milchrindvieh in Umbria wirklich 9,7 % betrug (Grenzen der Zuversichtlichkeit 99 %, 7,0 %, 12,4 %).E’ stata valutata la prevalenza dell’enterite paratubercolare in alcuni allevamenti di bovini da latte in Umbria. Allo scopo č stato effettuato uno screening tramite test ELISA che consente l’individuazione di animali con immunitŕ umorale nei confronti di MAP (Mycobacterium avium complex). Il test ELISA ha messo in evidenza una prevalenza variabile nelle aziende saggiate, con una media complessiva del 5.6% ed una prevalenza vera nella regione del 9.7% (limiti fiduciari 99%, 7.0%, 12.4%)
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