On the geometric genus of reducible surfaces and degenerations of surfaces to unions of planes

In this paper we study some properties of degenerations of surfaces whose general fibre is a smooth projective surface and whose central fibre is a reduced, connected surface $X \subset IP^r$, $r \geq 3$, which is assumed to be a union of smooth projective surfaces, in particular of planes. Our original motivation has been a series of papers of G. Zappa which appeared in the 1940-50's regarding degenerations of scrolls to unions of planes. Here, we present a first set of results on the subject; other aspects are still work in progress and will appear later. We first study the geometry and the combinatorics of a surface like $X$, considered as a reduced, connected surface on its own; then we focus on the case in which X is the central fibre of a degeneration of relative dimension two over the complex unit disk. In this case, we deduce some of the intrinsic and extrinsic invariants of the general fibre from the ones of its central fibre. In the particular case of $X$ a central fibre of a semistable degeneration, i.e. $X$ has only global normal crossing singularities and the total space of the degeneration is smooth, some of the above invariants can be also computed by topological methods (i.e., the Clemens-Schmid exact sequence). Our results are more general, not only because the computations are independent on the fact that $X$ is the central fibre of a degeneration, but also because the degeneration is not semistable in general.Comment: latex2e, 26 pages, 11 figure

Special scrolls whose base curve has general moduli

In this paper we study the Hilbert scheme of smooth, linearly normal, special scrolls under suitable assumptions on degree, genus and speciality.Comment: Latex2e, shorter versio

The anthocyanin content in berries of the hybrid grape cultivars Clinton and Isabella

Berries of the hybrid grape cultivars Clinton and Isabella were analysed for their anthocyanin content and their anthocyanin profile. Antho-cyanins were extracted from grape skins by an ethanol/water/hydro-chloric acid solution. The extracts were used for spectrophotometric measurements and were purified by solid phase extraction to perform high performance liquid chromatography analysis (HPLC). As characteristics of hybrid grapes the anthocyanins 3,5-O-diglucoside and 3-O-(6-O-p-coumaroyl),5-O-diglucoside were identified. Many different anthocyanin compounds were found in Clinton grapes

Changes in carbonyl compounds in Chardonnay and Cabernet Sauvignon wines as a consequence of malolactic fermentation

To study changes in carbonyl compounds in Chardonnay and Cabernet Sauvignon wines as a consequence of malolactic fermentation (MLF), wines were fermented by inoculation of commercial strains of Oenococcus oeni, and compared with unfermented (control) wines. Carbonyl compounds were determined by GC/MS analysis on the basis of their O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine derivatives after sample preparation on an ion exchange column to remove pyruvic acid. With MLF, marked changes were revealed, particularly with regard to diacetyl, acetoin and aliphatic saturated aldehydes; the presence of unsaturated aldehydes was also revealed. A significant increase in glycoladehyde was observed, which is presumed to be part of a reduction system with glyoxal. Higher acetoin/diacetyl ratios were found in Chardonnay and higher glycolaldehyde/glyoxal ratios in Cabernet Sauvignon.

Essential oils against Varroa destructor: a soft way to fight the parasitic mite of Apis mellifera

Essential oils (EOs) extracted from the aromatic plants Artemisia annua, Artemisia verlotiorum, Cinnamomum verum, and Citrus reticulata were investigated as repellents against the honey bees parasitic mite Varroa destructor. In laboratory tests, all EOs except C. reticulata exerted significant repellent activity against the mite after 24 h exposure. C. verumwas the most effective EO against V. destructor (median effective concentration EC50 =1.30 μL L−1), and the least toxic against honey bees (EC50 = 13.29 μL L−1). Because of its high selectivity ratio (A. mellifera LD50/V. destructor EC50 = 10.22), C. verum EO was then tested to control varroosis in colonies in field trials. The results of open field tests confirmed the efficacy observed in the laboratory. After one week of treatment, colonies treated with the EO showed a significant reduction of V. destructor infestation (about 65% at the dose of 25.0 μL L−1) and no negative effects on A. mellifera. Overall, our experiment indicated that C. verum EO could be used to effectively control varroosis in the hive with no side effects on the bee colonies

Valorisation of hemp inflorescence after seed harvest: Cultivation site and harvest time influence agronomic characteristics and essential oil yield and composition

Cannabis sativa L. is a multipurpose crop, whose industrial varieties, complying with the 0.2% Δ9-tetrahydrocannabinol (THC) threshold set by the EU legislation, can be cultivated without restrictions by farmers. Other than its traditional use as a source of bast fibres from the stems, the fixed oil extracted from its seeds represents a valuable nutritional product. Its inflorescence is also a further exploitable threshing residue originating from seed harvest, as they can be used for the extraction of the essential oil (EO), a high-value added product. This study aims at contributing to the re-evaluation of industrial hemp cultivation as an agro-environmentally sustainable crop for the diversification of Mediterranean cropping systems, by exploring the possibility of recovering the EO from the inflorescence after seed harvest. The influence of the cultivation site (lowland and upland of Pisa province, Tuscany, central Italy) and the harvest time (August and September) have been investigated on the ‘Fedora 17’ monoecious hemp cultivar: the main agronomic traits in term of stem, seed and inflorescence production, as well as essential oil yield and composition have been evaluated. The crops harvested in September exhibited higher total dry yield as well as higher inflorescence and stem yields, while neither the site nor the harvesting period influenced the seed production, which was significantly influenced by harvest time x cultivation site interaction. Both seed fixed oil and crude protein content were affected by the cultivation site only, but in the opposite sense: the highest seed oil content was reached in the upland area, while the plants grown in the plain area exhibited the largest seed protein content. All the extracted EOs were rich in sesquiterpenes (mostly β-caryophyllene and its oxidized derivatives, and α-humulene), but monoterpene hydrocarbons were significantly represented as well (mainly α- and β-pinene, and myrcene). The EOs extraction yields were slightly higher in the earlier harvest for both sites

Scutellaria caucasica A. Ham.: Morphological features and headspace characterization

In the context of a wide research project, a micromorphological and phytochemical characterization was performed on the vegetative and reproductive organs of Scutellaria caucasica A. Ham. (Lamiaceae), cultivated at the Ghirardi Botanic Garden (Toscolano Maderno, BS, Lombardy, Italy). The morphological survey revealed the presence of both non-glandular and glandular trichomes. The latter belonged to three different morphotypes: peltate, short-stalked and long-stalked capitate. Histochemical assays demonstrated that the terpenes biosynthesis mainly took place in the peltates, while short-stalked capitates secreted only polysaccharides; the long-stalked ones mainly produced polysaccharides, coupled with terpene and polyphenolic fractions. An element of novelty was represented by the characterization of the VOC emission profile. Leaves and flowers showed differences in their emissions: the floral profile had a higher number of compounds than that of the leaves (37 vs 29), with a higher heterogeneity. The almost totality of the leaf profile was characterized by sesquiterpene hydrocarbons (98.8 %), while the flowers presented a more varied composition, with sesquiterpene hydrocarbons (87.2 %), monoterpenes (10.4 % oxygenated, 1.8 % hydrocarbons) and non-terpenes derivatives (0.6 %). The most abundant compounds were \u3b3-muurolene (42.6 %) and \u3b2-caryophyllene (35.0 %) in the leaves and in the flowers, respectively. In the flower headspace, 16 exclusive compounds were identified, among which germacrene D (31.7 %) dominated; leaves had 8 exclusive compounds, with valencene (1.8 %) as the most represented one. 21 common compounds were revealed: \u3b2-caryophyllene (34.1 % leaves; 35.0 % flowers), \u3b1-humulene (3.0 % leaves; 3.1 % flowers), alloaromadendrene (2.4 % leaves; 1.0 % flowers), \u3b1-copaene (2.1 % leaves; 2.7 % flowers) and \u3b2-copaene (2.2 % leaves; 1.5 % flowers) were the most abundant ones. \u3b3-Muurolene relative abundances (42.6 % leaves; 0.7 % flowers) were very different between the two profiles. Overall, this work represented the first multidisciplinary study on S. caucasica, combining a scientific research approach with the policies of the Open Science

Guest Editorial Special Cluster on Functionalized Metasurface-Based Covers and Unconventional Domes for Dynamic Antenna Systems

The papers in this special section focus on recent advancements in this field and provide an overview of the potential applications of this technology in the next generation antenna devices, with emphasis on metamaterial-based enhancements enabling real-time control of their radiation characteristics