Accumulation and erosion of Mars' south polar layered deposits     

Seu R  Phillips RJ  Alberti G  Biccari D  Bonaventura F  Bortone M  Calabrese D  Campbell BA  Cartacci M  Carter LM  Catallo C  Croce A  Croci R  Cutigni M  Di Placido A  Dinardo S  Federico C  Flamini E  Fois F  Frigeri A  Fuga O  Giacomoni E  Gim Y  Guelfi M  Holt JW  Kofman W  Leuschen CJ  Marinangeli L  Marras P  Masdea A  Mattei S  Mecozzi R  Milkovich SM  Morlupi A  Mouginot J  Orosei R  Papa C  Paternò T  Persi del Marmo P  Pettinelli E  Pica G  Picardi G  Plaut JJ  Provenziani M  Putzig NE  Russo F  Safaeinili A  Salzillo G 《Science (New York, N.Y.)》2007,317(5845):1715-1718

Mars' polar regions are covered with ice-rich layered deposits that potentially contain a record of climate variations. The sounding radar SHARAD on the Mars Reconnaissance Orbiter mapped detailed subsurface stratigraphy in the Promethei Lingula region of the south polar plateau, Planum Australe. Radar reflections interpreted as layers are correlated across adjacent orbits and are continuous for up to 150 kilometers along spacecraft orbital tracks. The reflectors are often separated into discrete reflector sequences, and strong echoes are seen as deep as 1 kilometer. In some cases, the sequences are dipping with respect to each other, suggesting an interdepositional period of erosion. In Australe Sulci, layers are exhumed, indicating recent erosion.  相似文献   

Ranges of nutrient concentrations in Quercus ilex leaves at natural and urban sites     

Giulia Maisto  Daniela Baldantoni  Anna De Marco  Anna Alfani  Amalia Virzo De Santo 《植物养料与土壤学杂志》2013,176(5):801-808

The leaf nutrient concentrations and the N‐to‐nutrient ratios were analyzed to evaluate the nutritional status of holm oaks (Quercus ilex L.) experiencing various anthropogenic pressures. Leaves (1 year old) of Q. ilex and surface soil (0–5 cm) surrounding the trees were collected at seven natural and seven urban sites in Campania Region (Southern Italy) and analyzed for the concentrations of macro (C, N, P, S) and micronutrients (Mn, K, Na, Cu, Mg, Ca, Fe, Zn). The available soil fraction of micronutrients was also evaluated. The nutrients showed different concentration ranges for the natural and the urban sites in the soil (total and available) and in the leaves, that we reported separately. Organic‐matter content and macronutrient concentrations were higher in the natural soils, while the highest leaf N, S, and P concentrations were found at some urban sites. Concentrations of Cu, Na and Zn both in leaves and soil, and Mg and Fe in leaves from the urban sites appeared to be affected by air depositions. Manganese was the only micronutrient to show higher concentrations at the natural than at the urban sites, both in soil and leaves. For this nutrient, in addition, a relationship between leaf and available soil concentrations was found at the natural sites. The ratios between the concentrations of N and each studied nutrient in the leaves highlighted a different nutritional status between the plants from the natural and urban sites.  相似文献   

Effects of pruning and stand density on the productionof new epicormic shoots in young stands of pedunculate oak (Quercus robur L.)     

Giulia Attocchi 《Annals of Forest Science》2013,70(7):663-673

Context

Avoidance or control of epicormic shoots is among the major silvicultural challenges for the production of high-quality oak timber. In northern Europe, contemporary oak silviculture aims to produce valuable timber on a relatively short rotation, applying early, heavy thinning combined with artificial pruning.

Aims

The aim of this study was to analyse the effects of pruning and stand density on the production of new epicormic shoots on young trees of pedunculate oak (Quercus robur L.).

Methods

The study was based on two field experiments in even-aged stands of pedunculate oak subjected to different thinning practices and early selection of potential future crop trees. From ages 13 to 15 years, stem density was reduced to 300 trees ha^?1, 1,000 ha^?1 or stands remained unthinned. Pruning was conducted on selected trees at ages 22–24 years. At that age, the stem density in unthinned control plots ranged from 2,500 to 3,100 ha^?1. All treatments were replicated twice within each experiment.

Results

Pruning led to an overall increase in the total production of new epicormic shoots. More epicormic shoots were produced in the lower part of the stem (0–3 m in height) than in the upper part (3–6 m). The number of new epicormic shoots increased with increasing stand density.

Conclusion

Early, heavy thinning combined with high pruning at regular intervals may help shorten the rotation length for pedunculate oak without further reduction in wood quality than that which is caused by wider annual growth rings.  相似文献   

Benefits under the Sea: The Role of Marine Compounds in Neurodegenerative Disorders     

Mariano Catanesi  Giulia Caioni  Vanessa Castelli  Elisabetta Benedetti  Michele d&#x;Angelo  Annamaria Cimini 《Marine drugs》2021,19(1)

Marine habitats offer a rich reservoir of new bioactive compounds with great pharmaceutical potential; the variety of these molecules is unique, and its production is favored by the chemical and physical conditions of the sea. It is known that marine organisms can synthesize bioactive molecules to survive from atypical environmental conditions, such as oxidative stress, photodynamic damage, and extreme temperature. Recent evidence proposed a beneficial role of these compounds for human health. In particular, xanthines, bryostatin, and 11-dehydrosinulariolide displayed encouraging neuroprotective effects in neurodegenerative disorders. This review will focus on the most promising marine drugs’ neuroprotective potential for neurodegenerative disorders, such as Parkinson’s and Alzheimer’s diseases. We will describe these marine compounds’ potential as adjuvant therapies for neurodegenerative diseases, based on their antioxidant, anti-inflammatory, and anti-apoptotic properties.  相似文献   

Current progress on genetic interactions of rice with rice blast and sheath blight fungi     

Yulin Jia  Guangjie Liu  Stefano Costanzo  Seonghee Lee  Yuntao Dai 《Frontiers of Agriculture in China》2009,3(3):231-239

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.  相似文献   

Early adult learning affects host preferences in the tephritid parasitoid Psyttalia concolor (Hymenoptera: Braconidae)     

Giulia Giunti  Giovanni Benelli  Russell H. Messing  Angelo Canale 《Journal of pest science》2016,89(2):529-537

  相似文献   

Dietary effect of dried bay leaves (Laurus nobilis) meal on some biochemical parameters and on plasma oxidative status in New Zealand white growing rabbit          下载免费PDF全文

D. Casamassima  M. Palazzo  F. Vizzarri  R. Coppola  C. Costagliola  C. Corino  A. Di Costanzo 《Journal of animal physiology and animal nutrition》2017,101(5):e175-e184

Effects of dietary supplementation of Laurus nobilis on selected biochemical parameters and plasma oxidative status in growing rabbits, fed with and without enriched‐fat diet, integrated with and without dried bay leaves meal, were investigated. In the test, 120 New Zealand white 35‐day‐old male rabbits were divided into four homogeneous groups of 30 animals each. A negative control group (CON) received a feed that met the animal nutrient requirement; a positive control group (CG) receiving a supplement of 2.5% pig fat in feed; an experimental group (GA) feeding an integration of 2.5% pig fat and 1 g/kg of dried bay leaves (Laurus nobilis) in feed; an experimental group (CA) with dried bay leaves at the rate of 1 g/kg in feed. The dietary integration with dried bay leaves meal have resulted in a significant decrease in the blood lipid profile, glycemic profile and liver enzymes, with reduced levels of ALT and AST, glucose, total cholesterol, LDL cholesterol, triglycerides and increased HDL cholesterol. Plasma oxidative status markers have statistically improved with an increase in blood total phenols, SOD, ORAC, the FRAP and lipo‐vitamin concentration, together with a significant reduction in ROMs and the MDA values. The results of present research underline that the dietary treatment with bay leaves meal, in the extend of 1 g/kg feed, confirms the lowering cholesterol activity and the epato‐protective and ipo‐glycemic effect in enrich‐fat diet, controlling the oxidative status of plasma markers.  相似文献   

Eco-physiological and Antioxidant Responses of Holm Oak (<Emphasis Type="Italic">Quercus ilex</Emphasis> L.) Leaves to Cd and Pb     

Carmen Arena  Lucia Santorufo  Pia Rosa Cataletto  Valeria Memoli  Rosaria Scudiero  Giulia Maisto 《Water, air, and soil pollution》2017,228(12):459

Plants of the urban environment are exposed to a wide range of pollutants, including heavy metals. This research studies in situ the eco-physiological and antioxidant responses of holm oak (Q. ilex) leaves to Pb and Cd to assess the mechanisms of metal tolerance in this species, widely used as biomonitor. Leaves of plants grown at parks and roadsides were analyzed for photosynthetic activity, Pb and Cd concentration in tissues and cell-free extracts, thiol groups, D1 and Rubisco protein content, ascorbic acid (AsA) amount, and catalase (CAT) activity. The main results evidenced that Cd concentration was higher in leaves collected at the park out from the downtown; whereas Pb was most abundant in leaves sampled at the roadside nearby the highway. Pb in cell-free extracts was higher in park than in roadside leaves. Although Cd in the leaf tissues was twofold lower than Pb, it was more abundant than Pb in cellular extracts deprived of all particulate matter. Leaves responded to different concentration of Cd and Pb modulating some eco-physiological and biochemical traits, roadside leaves showed reduced leaf lamina, higher content of photosynthetic pigments, hydrogen peroxide, and AsA, as well as higher CAT activity compared to park leaves. In the roadside leaves, a stress condition for photosynthetic apparatus can be hypothesized on the basis of the decline of photochemical activity, the increase of NPQ, and the reduction of Rubisco and D1 protein content. The elevated presence of thiol groups in these leaves suggests a possible role of Pb and Cd in activation of antioxidant responses.  相似文献   

Vessel noise pollution as a human threat to fish: assessment of the stress response in gilthead sea bream (<Emphasis Type="Italic">Sparus aurata</Emphasis>, Linnaeus 1758)     

Monica Celi  Francesco Filiciotto  Giulia Maricchiolo  Lucrezia Genovese  Enza Maria Quinci  Vincenzo Maccarrone  Salvatore Mazzola  Mirella Vazzana  Giuseppa Buscaino 《Fish physiology and biochemistry》2016,42(2):631-641

This study examined the effects of boat noise pollution on the stress indices of gilthead sea bream (Sparus aurata, Linnaeus 1758). To assess the stress response in these fish, biometric values and plasma parameters such as ACTH, cortisol, glucose, lactate, haematocrit, Hsp70, total protein, cholesterol, triglycerides and osmolarity were analysed. After acclimatization of the animals, the experiment was carried out in a tank fitted with underwater speakers where the fish were exposed to sound treatments (in duplicate) consisting of: 10 days of no sound (control treatment; the animals were only exposed to the experimental tank’s background noise) and 10 days of noise derived from original recordings of motor boats, including recreational boats, hydrofoil, fishing boat and ferry boat (vessel noise treatment). The exposure to noise produced significant variations in almost all the plasma parameters assessed, but no differences were observed in weights and fork lengths. A PERMANOVA analysis highlighted significantly increased values (p < 0.05) of ACTH, cortisol, glucose, lactate, haematocrit, Hsp70, cholesterol, triglycerides and osmolarity in the fish exposed to vessel noise for 10 days. This study clearly highlights that anthropogenic noise negatively affects fish, and they are valuable targets for detailed investigations into the effects of this global pollutant. Finally, these experimental studies could represent part of the science that is able to improve the quality of the policies related to management plans for maritime spaces (Marine Strategy Framework Directive 56/2008 CE) that are aimed at stemming this pollutant phenomenon.  相似文献   

Field strains of Stemphylium vesicarium with a resistance to dicarboximide fungicides correlated with changes in a two-component histidine kinase     

Giulia Alberoni  Marina Collina  Catherine Lanen  Pierre Leroux  Agostino Brunelli 《European journal of plant pathology / European Foundation for Plant Pathology》2010,128(2):171-184

In Stemphylium vesicarium, four phenotypes were recognized according to their in vitro responses to dicarboximide fungicides: S (sensitive), S₊ (low resistant to iprodione and procymidone but moderately resistant to vinclozolin), R₁ (moderately resistant to iprodione and vinclozolin but highly resistant to procymidone), R₂ (highly resistant to all dicarboximides). Cross-resistance was observed between dicarboximides and aromatic hydrocarbon fungicides in all cases while cross-resistance to phenylpyrroles was only detected in R₂ phenotype. Moreover, no changes were noted in sensitivity to oxidative and osmotic stress inducers. An osmosensing histidine kinase gene, homologous to OS1 from Neurospora crassa, was sequenced from several field isolates of Stemphylium vesicarium. This gene is predicted to encode a 1,329 amino acid protein, comprising a conserved histidine-kinase domain in the C-terminal region and six tandem repeats of about 90 amino acids at the N-terminal end. In S₊ and R₁ phenotype isolates, a single amino acid substitution was observed in the first amino acid repeat; F267L and L290S respectively. For the R₂ isolates, the exchanges T765R or Q777R were located within the histidine-kinase domain.  相似文献