Search results for "QK"
showing 10 items of 311 documents
Pine stand density influences the regeneration of Acacia saligna (Labill.) H.L.Wendl. and native woody species in a mediterranean coastal pine planta…
2018
Mediterranean plantations are the most suitable areas to assess vegetation dynamics and competitive interactions between native and exotic woody species. Our research was carried out in a coastal pine plantation (Sicily) where renaturalization by native species (Pistacia lentiscus L. and Olea europaea var. sylvestris) and invasion by Acacia saligna (Labill.) H.L.Wendl. simultaneously occur. The regeneration pattern of woody species in the pine understory was evaluated in six experimental plots along a stand density gradient, from 200 to approximately 700 pines per hectare. Both pine stand density and regeneration by native species had a significant negative relationship with Acacia natural …
The Lygeo-Stipetea class in Sicily
2010
Basing on literature data and unpublished relevés from Sicily, a survey of the syntaxa belonging to the class Lygeo-Stipetea Rivas-Martínez 1978 is presented. This perennial vegetation is characterized by the dominance of big caespitose hemicryptophytes, and it is widely distributed in Sicily from the sea level up to 1500 m a.s.l. The class is represented in Sicily by two orders, floristically and ecologically well differentiated: Lygeo-Stipetalia, including the sole alliance Moricandio-Lygeion exclusively of clayey substrates, and Hyparrhenietalia hirtae, including five alliances (Hyparrhenion hirtae, Avenulo cincinnatae-Ampelodesmion mauritanici, Thero-Brachypodion ramosi, B…
Ecotoxicological Effects of Ibuprofen on Plant Growth of Vigna unguiculata L.
2020
Despite the prevalence of the common pharmaceutical ibuprofen (IBU) in water and sediments worldwide, the effects of IBU on plants are largely unknown. This study was designed to assess the ecotoxicological effects of emerging pharmaceutical pollutant IBU on plant growth and development in a series of toxicity experiments using cowpea (Vigna unguiculata). Plant growth parameters (morphological and physicochemical) were investigated under a series of IBU concentrations (0, 400, 800, 1200, 1600, 2000 ppm IBU). IBU exposure reduced the shoot and root lengths, fresh and dry weights, leaf area, and chlorophyll a and b, carotenoid, total chlorophyll, mineral (K and Mg), glutathione reductase, and…
Measurement of the single-top-quark production cross section at CDF.
2008
We report a measurement of the single top quark production cross section in 2.2 ~fb-1 of p-pbar collision data collected by the Collider Detector at Fermilab at sqrt{s}=1.96 TeV. Candidate events are classified as signal-like by three parallel analyses which use likelihood, matrix element, and neural network discriminants. These results are combined in order to improve the sensitivity. We observe a signal consistent with the standard model prediction, but inconsistent with the background-only model by 3.7 standard deviations with a median expected sensitivity of 4.9 standard deviations. We measure a cross section of 2.2 +0.7 -0.6(stat+sys) pb, extract the CKM matrix element value |V_{tb}|=0…
Diurnal Regulation of Leaf Water Status in High- and Low-Mannitol Olive Cultivars
2014
The role of mannitol and malic acid in the regulation of diurnal leaf water relations was investigated in ‘Biancolilla’ (high-mannitol) and ‘Cerasuola’ (low-mannitol) olive trees. Photosynthetic photon flux density (PPFD), vapor pressure deficit (VPD), stomatal conductance (gs), transpiration rate (T), relative water content (RWC), mannitol and malic acid were measured in ‘Biancolilla’ and ‘Cerasuola’ leaves during a dry and hot day of summer in Sicily. In general, leaves of ‘Biancolilla’ trees exhibited greater mannitol content, higher gs and T, but lower RWC than leaves of ‘Cerasuola’ trees. Differences in gs and T between the two cultivars were evident mainly in mid to late morning. ‘Bia…
Shedding light on typical species: Implications for habitat monitoring
2021
Habitat monitoring in Europe is regulated by Article 17 of the Habitats Directive, which suggests the use of typical species to assess habitat conservation status. Yet, the Directive uses the term “typical” species but does not provide a definition, either for its use in reporting or for its use in impact assessments. To address the issue, an online workshop was organized by the Italian Society for Vegetation Science (SISV) to shed light on the diversity of perspectives regarding the different concepts of typical species, and to discuss the possible implications for habitat monitoring. To this aim, we inquired 73 people with a very different degree of expertise in the field of veget…
Deletion of beta-fructofuranosidase (invertase) genes is associated with sucrose content in Date Palm fruit
2019
AbstractThe fruit of date palm trees are an important part of the diet for a large portion of the Middle East and North Africa. The fruit is consumed both fresh and dry and can be stored dry for extended periods of time. Date fruits vary significantly across hundreds of cultivars identified in the main regions of cultivation. Most dried date fruit are low in sucrose but high in glucose and fructose. However, high sucrose content is a distinctive feature of some date fruit and affects flavor as well as texture and water retention. To identify the genes controlling high sucrose content we analyzed date fruit metabolomics for association with genotype data from 121 date fruits. We found signif…
Syntaxonomical survey of Geranio-Cardaminetalia hirsutae: Semi-natural therophytic vegetation of the Mediterranean region
2007
A syntaxonomical scheme, including geographical range and synonymies of all the associations ascribed to Geranio-Cardaminetalia hirsutae, is presented. This order, framed into the class Stellarietea mediae, groups sciaphilo-subnitrophilous annual vegetation of natural and semi-natural habitats, commonly occurring on substrata rich in organic matter, accumulating on stone-walls, shaded rocks and initial soils, often under the canopy of shrubs and trees. Twelve new associations from Sardinia, Sicily, Egean islands and Israel are here described for the first time.
Potamogeton pusillus agg. in Tajikistan (Middle Asia)
2011
The locality of <em>Potamogeton berchtoldii</em> Fieber, the new species to the flora of Tajikistan (Middle Asia), together with its ecological conditions are presented. Additionally, the list of herbarium specimens of <em>P. pusillus</em> L. s. stricto gathered in Tajikistan and few specimens of <em>P. berchtoldii</em> collected from the area of adjacent countries are also provided. Taxonomical position of the species within the <em>Potamogeton pusillus</em> aggregation, the main morphological features of both taxa and possibility of finding other localities are discussed.
Search for anomalous top-quark couplings with the D0 detector
2008
Anomalous Wtb couplings modify the angular correlations of the top quark decay products and change the single top quark production cross section. We present limits on anomalous top quark couplings by combining information from W boson helicity measurements in top quark decays and anomalous coupling searches in the single top quark final state. We set limits on right-handed vector couplings as well as left-handed and right-handed tensor couplings based on about 1fb^-1 of data collected by the D0 experiment.