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41.
Mundell CG Steele IA Smith RJ Kobayashi S Melandri A Guidorzi C Gomboc A Mottram CJ Clarke D Monfardini A Carter D Bersier D 《Science (New York, N.Y.)》2007,315(5820):1822-1824
We report the optical polarization of a gamma-ray burst (GRB) afterglow, obtained 203 seconds after the initial burst of gamma-rays from GRB 060418, using a ring polarimeter on the robotic Liverpool Telescope. Our robust (2sigma) upper limit on the percentage of polarization, less than 8%, coincides with the fireball deceleration time at the onset of the afterglow. The combination of the rate of decay of the optical brightness and the low polarization at this critical time constrains standard models of GRB ejecta, ruling out the presence of a large-scale ordered magnetic field in the emitting region. 相似文献
42.
Souza Danilo Santos Souza Jane Delane Reis Pimentel Coutinho Janclei Pereira da Silveira Tayse Ferreira Ferreira Ballus Cristiano Augusto Filho José Teixeira Bolini Helena Maria Andre Godoy Helena Teixeira 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(1):70-75
Plant Foods for Human Nutrition - Tamarind fruits are consumed worldwide and their seeds have an underexploited potential. We assessed the effect of the addition of a freeze-dried aqueous of... 相似文献
43.
Pierluigi Bombi Cristiano Fedi Marzio Zapparoli Mario Cammarano Gabriele Guidolotti Emanuele Pallozzi 《国际虫害防治杂志》2019,65(2):147-153
The Asian chestnut gall wasp was accidentally introduced in Italy in 2002 and spread across Europe in the following years, becoming a serious threat for chestnut cultivations and rural economies of many countries. Exploring the variation in susceptibility of the host genetic resources is crucial to face the spreading of this pest. We used an experimental approach for testing the differential susceptibility within and between populations of European chestnut. For doing this, we compared both the infestation level and the rate of immune individuals in trees from populations of Spain, Italy, and Greece. We found that the level of infestation is not significantly different in the different provenances but that a higher rate of immune trees occur in Greece. Our results suggest that two different contingents of trees compose Greek populations: one major group of trees with the same susceptibility as the other populations and a second minor group of trees resistant to gall wasp infestation. Our data lay the basis for improving the currently adopted measures to mitigate gall wasp impacts. 相似文献
44.
Colour is an important component of durum wheat quality affecting consumer’s choice. Pasta colour is the result of the carotenoid pigments accumulated in the seed endosperm and of the enzymatic activities responsible for their degradation. Thus, increasing yellow colour is a valuable goal for improving the commercial and nutritional values of durum wheat products. This work reports the set up of a micro-method for the determination of Yellow Pigment Content (YPC) in durum wheat. The novel method, although similar in principle to the Official Method AACC 14-50, allows the use of micro-amount of samples (10–100 mg), a condition that for durum wheat corresponds to a single kernel, and micro-amount of extraction solvent (water-saturated 1-butanol, 250–500 μL). These improvements together with a short extraction time lead to significant benefits from the practical and the economic point of view. The improved method has been validated using nine durum wheat cultivars extracted in 15 min with the ultrasonic bath. The YPC was calculated by reading the absorbance at 435 nm after the manual injection of an aliquot of extract directly into a UV–Vis HPLC detector. The results obtained were comparable and not significantly different from the Official AACC Method 14-50. 相似文献
45.
Cristiano N. Nesi Giselda Alves Paulo Justiniano Ribeiro Jr Louise L. May De Mio 《European journal of plant pathology / European Foundation for Plant Pathology》2014,139(4):663-677
Peach rust (Tranzschelia discolor) is a major foliar disease of peach that can cause severe defoliation. Few epidemiological studies have been conducted on peach rust, and there is no information concerning the spatial distribution of the disease within the canopy. This study aimed to characterise the onset and temporal progress of peach rust in three height strata in peach trees grown in two different orchards: one treated with fungicide and the second non-treated. Evaluations were conducted fortnightly between November and April for two consecutive years. Positional information for the disease within the canopy was obtained by assessing the incidence and severity of peach rust on leaves in both orchards. A linear mixed model with the position of shoots as the fixed effect and cultivars and blocks as random effects was adopted for the data analysis over both seasons, in the fungicide-treated orchard incidence and severity ranged from 60 to 90 % and 0.5 to 2 %, respectively, while in the non-treated orchard incidence and severity ranged from 90 to 100 % and 10 to 15 %, respectively. The area under the disease progress curve was greater for the upper shoots compared to the lower shoots, but the disease progress rates were similar. The logistic and exponential models best fitted the incidence and severity data, respectively. Urediniospores were detected by traps within the experimental area between late winter and early spring. Predominance of autoinfection or alloinfection is discussed. 相似文献
46.
Belle Cristiano Kaspary Tiago Edu Groth Mártin Zanchett Cocco Kassia Luiza Teixeira 《植物病害和植物保护杂志》2017,124(4):393-397
Journal of Plant Diseases and Protection - Samples of melon plants with aerial symptoms that represented yellowing of leaves and stunting, and below-ground galls on the roots from two growing areas... 相似文献
47.
Acutis PL Martucci F D'Angelo A Peletto S Colussi S Maurella C Porcario C Iulini B Mazza M Dell'atti L Zuccon F Corona C Martinelli N Casalone C Caramelli M Lombardi G 《Veterinary research》2012,43(1):8
ABSTRACT: Susceptibility of sheep to scrapie, a transmissible spongiform encephalopathy of small ruminants, is strongly influenced by polymorphisms of the prion protein gene (PRNP). Breeding programs have been implemented to increase scrapie resistance in sheep populations; though desirable, a similar approach has not yet been applied in goats. European studies have now suggested that several polymorphisms can modulate scrapie susceptibility in goats: in particular, PRNP variant K222 has been associated with resistance in case-control studies in Italy, France and Greece. In this study we investigated the resistance conferred by this variant using a natural Italian goat scrapie isolate to intracerebrally challenge five goats carrying genotype Q/Q 222 (wild type) and five goats carrying genotype Q/K 222. By the end of the study, all five Q/Q 222 goats had died of scrapie after a mean incubation period of 19 months; one of the five Q/K 222 goats died after 24 months, while the other four were alive and apparently healthy up to the end of the study at 4.5 years post-challenge. All five of these animals were found to be scrapie negative. Statistical analysis showed that the probability of survival of the Q/K 222 goats versus the Q/Q 222 goats was significantly higher (p = 0.002). Our study shows that PRNP gene mutation K222 is strongly associated with resistance to classical scrapie also in experimental conditions, making it a potentially positive target for selection in the frame of breeding programs for resistance to classical scrapie in goats. 相似文献
48.
Souza PE Oliveira SS Aguiar-Filho CR Cunha AL Albuquerque RF Evêncio-Neto J Riet-Correa F Mendonça FS 《Research in veterinary science》2012,93(3):1337-1340
Three outbreaks of primary photosensitization caused by Froelichia humboldtiana are reported in the semiarid region of the states of Pernambuco and Paraíba, in northeastern Brazil. The disease occurred from March to June 2011, affecting 27 bovines out of a total of 70. The main lesions consisted of dermatitis of the white skin, with edema and necrosis. All the bovines recovered after removal from the areas invaded by F. humboldtiana. To produce the disease experimentally, one bovine with white skin was placed for 14days into an area with F. humboldtiana as the sole forage. This bovine presented photodermatitis on the third day of consumption. The serum concentrations of total, indirect, and conjugated bilirubin and the serum activities of gamma-glutamyl transferase (GGT) and aspartate-aminotransferase (AST) in the spontaneously affected cattle and in the experimental cattle remained within normal ranges. It is concluded that F. humboldtiana causes primary photosensitization in cattle in northeastern Brazil. 相似文献
49.
Urban sediment particle size and pollutants in Southern Brazil 总被引：1，自引：1，他引：0
Cristiano Poleto Edson C. Bortoluzzi Susanne M. Charlesworth Gustavo H. Merten 《Journal of Soils and Sediments》2009,9(4):317-327
Background, aim and scope
Studies of particulate-associated pollutants, or PAPs, in urban areas have become necessary due to their potentially deleterious effects on the environment. However, it is not just the sediments themselves which are problematic but also their particle size composition, which has a great influence on their capacity to adsorb and transport pollutants. This paper presents the particle size distributions and concentrations of five metals (Cr, Cu, Ni, Pb and Zn) of urban sediments collected from paved streets and gully pots from 20 cities in southern Brazil. The cities have different characteristics and hence sources of PAPs associated with differing geologies, soil types and type of urbanisation. Studies of this nature enable elucidation of the relationship between diffuse sources such as streets and gully pots and the likelihood of PAPs to subsequently pollute the urban aquatic environment.Materials and methods
Sediment samples were taken at random from paved streets and gully pots in 20 cities in Rio Grande do Sul state, southern Brazil by means of a portable vacuum cleaner to avoid loss of finer particles. The particle sizes of the samples were measured using a Cilas® 1180 laser particle analyzer, and the concentrations of five metals (Cr, Cu, Ni, Pb and Zn) were determined by wet acid digestion (HCl–HF–HClO4–HNO3) followed by inductively coupled plasma atomic emission spectroscopy on the <63-µm fraction.Results
It was found that in comparison to sediments collected from the streets, gully pot sediments were more heterogeneous in terms of particle size and also that sediment samples from the gully pots were predominantly coarser than those originating on the streets. From the gully pot results, analysis of the modal particle diameter enabled the cities to be divided into three categories. The concentrations of metals in the street sediments were similar across all 20 cities, with all concentrations above background values.Discussion
The fact that concentrations of metals in the street sediments were above statutory guideline values and that the coarser material was deposited in the gully pots suggests that the finer, more polluted sediment is not retained in the gully pots but is transported to the nearest local receiving watercourse. This finding has implications for management strategies for reducing pollution in urban environments.Conclusions
High concentrations of Cr, Cu, Ni, Pb and Zn in the <63-µm fraction of street sediments, in combination with coarse material retained in the gully pots, indicate that metals could be transferred quite rapidly from the diffuse source of pollutants, on impermeable street surfaces, to receiving watercourses.Recommendations and perspectives
Studies of urban sediment particle size and geochemistry enable predictions to be made of sediment behaviour in urban environments. This will inform management strategies such as the possibility of including sustainable urban drainage systems in future management plans, in which it is useful to know how efficient the drainage system is from the point of view of sediment deposition in the urban aquatic environment and the potential for pollution of receiving waters. 相似文献50.
Improvement in Brazilian wheat breeding: changes in developmental phases and ecophysiological traits
Eduardo Beche Cristiano Lemes da Silva Matheus Henrique Todeschini Anderson Simionato Milioli Giovani Benin Jose Abramo Marchese 《Euphytica》2018,214(3):56
Understanding the processes responsible for genetic progress in grain yield and relating them to the growth and developmental phases of the wheat plant are essential for improving yield potential. This study aimed to evaluate the duration of developmental phases and eco-physiological traits associated to grain yield in Brazilian wheat cultivars released in different decades. Wheat cultivars released from 1940 to 2009 were evaluated during 2010 and 2011 in Pato Branco, Paraná, Brazil. The length of the following periods was compared: sowing-emergence (SW-EM), emergence-double ridge (EM-DR), double ridge-terminal spikelet (DR-TS), terminal spikelet-anthesis (TS-ANT), anthesis-physiological maturity (ANT-PM), sowing-anthesis (SW-ANT) and sowing-physiological maturity (SW-PM). Yield components were also measured. Breeding has reduced the days until anthesis by 14.2%, while it has extended the grain-filling period by 7.6%, compared to the first cultivars released in the country, thereby contributing to a significant increase in 1000-grain weight (12.4 and 9.0% in 2010 and 2011, respectively). The TS-ANT phase was the only phase prior to anthesis exhibiting an extension from old to modern cultivars; this phase increased 1.56 °Cd syear?1. Spike fertility index (SFI) showed increases of 37.8 and 23.8% in 2010 and 2011, respectively. Shortening of the time to flowering, shifting of critical phases of wheat development to better environmental conditions (i.e., TS-ANT phase), and selection for shorter cultivars have been directly responsible for the increase in spike dry weight at anthesis (SDWa) and SFI [i.e., grain number (GN)]. 相似文献