Legumes for Organic Cropping Systems

A field experiment which focuses on the yield performance of both durum wheat and sunflower included in a twoyear rotation between wheat/subterranean clover and sunflower was carried out in an organic farm in Central Italy. Three factors were included in the experiment according to a factorial design: a) two different previous crop sequences (four years of alfalfa, four years of annual crops); b) three fertilization levels (without and with animal manure incorporated at 15 or 40 cm depth); c) three durum wheat genotypes (Appulo, Arcangelo and Daunia cvs). The results obtained show that a previous alfalfa meadow allows the succeeding crops (wheat and sunflower) to achieve an appropriate and stable grain yield (about 4 and 3 t ha-1, respectively) even without organic manure for two consecutive cycles. When the durum wheat follows an annual crop sequence, grain yield appears unstable and the different levels of organic fertilizer determine a negative effect in the first cycle and a positive effect in the second cycle. The reseeding capability of sunflower was reduced by animal manure treatments and, consequently, the subclover biomass and its nitrogen content were generally lower in fertilized plots. Anyway, subclover biomass, which was ploughed in after reseeding as a green manure for sunflower, proved to be effective in stabilizing sunflower grain yield, especially in plots without any organic fertilization

Alternative Cropping Systems with Self Reseeding Annual Legumes in a Mediterranean Environment

Self-reseeding winter annual legumes (subclover and snail medic) have the potential to induce a significant shift towards a less energy-intensive and more environmentally friendly management in the modern and specialized cereal cropping systems. Nevertheless their use is practically unknown in mixed stands with winter cereals, where they can contribute to supply nitrogen and to reduce herbicides input. We conceived an alternative cropping system where an annual legume performs, respectively, as living mulch in a winter cereal (winter wheat), as a cover crop after reseeding and as dry mulch for the succeeding summer cereal (corn). Trials carried out at the Tuscia University (Central Italy) in the period 1995-1997 showed that almost all the tested legumes cultivars were able both to grow sufficiently as a living mulch in the wheat and to provide a good re-establishment and an abundant mulch after the wheat harvest for the next corn. Trifolium yanninicum cv Trikkala and Trifolium subterraneum cvs Karridale and Mount Barker ranked first in reseeding capacity (up to 400 seedlings m-2) and mulch production (up to 5 t ha-1). No difference in grain yield between wheat with a living mulch and wheat in pure stand was found when legumes, such as Trifolium yanninicum cvs Trikkala and Larisa, Trifolium brachycalycinum cv Clare, Trifolium subterraneum cv Nungarin and Medicago scutellata cv Kelson, were grown in binary mixture with wheat. The aboveground biomass production of the succeeding irrigated corn crop was largely dependent on the amount of legume dry mulch left upon the ground

Color Fields on the Light-Shell

We study the classical color radiation from very high energy collisions that produce colored particles. In the extreme high energy limit, the classical color fields are confined to a light-shell expanding at $c$ and are associated with a non-linear $\sigma$-model on the 2D light-shell with specific symmetry breaking terms. We argue that the quantum version of this picture exhibits asymptotic freedom and may be a useful starting point for an effective light-shell theory of the structure between the jets at a very high energy collider.Comment: 11 pages, no figure

Dynamical Surface Gravity in Spherically Symmetric Black Hole Formation

We study dynamical surface gravity in a general spherically symmetric setting using Painlev\'{e}-Gullstrand (PG) coordinates. Our analysis includes several definitions that have been proposed in the past as well as two new definitions adapted to PG coordinates. Various properties are considered, including general covariance, value at extremality, locality and static limit. We illustrate with specific examples of "dirty" black holes that even for spacetimes possessing a global timelike Killing vector, local definitions of surface gravity can differ substantially from "non-local" ones that require an asymptotic normalization condition. Finally, we present numerical calculations of dynamical surface gravity for black hole formation via spherically symmetric scalar field collapse. Our results highlight the differences between the various definitions in a dynamical setting and provide further insight into the distinction between local and non-local definitions of surface gravity.Comment: Final version to appear in Phys. Rev. D. Slight name change, further improvements to numerics and presentation, 25 pages, 7 figure

Habitat Patch Diversity Evaluation for Sustainability: a Case Study of a Rural Area in Central Italy

Landscape analysis is regarded as a new tool for monitoring and judging land use patterns in terms of sustainability of human activity systems at local level. A case study of evaluation for sustainability based on habitat patch diversity in an ecoregion of Central Italy is presented. In this region, ongoing land use patterns reflect both historical adaptation to local environmental constraints and positive, social-oriented management. More protective land use patterns are mostly widespread in fragile physiographic conditions like those of the mountain areas, where woodland, shrub, and grassland patches are larger and cover more than 90% of the land. This situation is regarded as a positive outcome of the traditional public ownership regime, because public lands amount to more than 70% in the mountain areas. The hilly areas, where public property drops to 28%, presents landscape metrics showing a well balanced situation between agricultural land use and protective native woods and grasslands, which provides a fine-grained and harmonious Mediterranean landscape. In the low-land areas, with anthropic pressure and more favourable conditions for crop productivity, there is much more agricultural land, even if some mitigation in terms of biodiversity maintenance is offered by the presence of hedgerow ecotones. In these areas, landscape analysis is not able to supply meaningful information about cropping system design and practices which can maintain a sustainable level of soil fertility and quality of natural resources and processes, and further analysis at cropping system level should be carried out

Polymer quantization, singularity resolution and the 1/r^2 potential

We present a polymer quantization of the -lambda/r^2 potential on the positive real line and compute numerically the bound state eigenenergies in terms of the dimensionless coupling constant lambda. The singularity at the origin is handled in two ways: first, by regularizing the potential and adopting either symmetric or antisymmetric boundary conditions; second, by keeping the potential unregularized but allowing the singularity to be balanced by an antisymmetric boundary condition. The results are compared to the semiclassical limit of the polymer theory and to the conventional Schrodinger quantization on L_2(R_+). The various quantization schemes are in excellent agreement for the highly excited states but differ for the low-lying states, and the polymer spectrum is bounded below even when the Schrodinger spectrum is not. We find as expected that for the antisymmetric boundary condition the regularization of the potential is redundant: the polymer quantum theory is well defined even with the unregularized potential and the regularization of the potential does not significantly affect the spectrum.Comment: 21 pages, LaTeX including 7 figures. v2: analytic bounds improved; references adde

Annexin A1 Released in Extracellular Vesicles by Pancreatic Cancer Cells Activates Components of the Tumor Microenvironment, through Interaction with the Formyl-Peptide Receptors

Pancreatic cancer (PC) is one of the most aggressive cancers in the world. Several extracellular factors are involved in its development and metastasis to distant organs. In PC, the protein Annexin A1 (ANXA1) appears to be overexpressed and may be identified as an oncogenic factor, also because it is a component in tumor-deriving extracellular vesicles (EVs). Indeed, these microvesicles are known to nourish the tumor microenvironment. Once we evaluated the autocrine role of ANXA1-containing EVs on PC MIA PaCa-2 cells and their pro-angiogenic action, we investigated the ANXA1 paracrine effect on stromal cells like fibroblasts and endothelial ones. Concerning the analysis of fibroblasts, cell migration/invasion, cytoskeleton remodeling, and the different expression of specific protein markers, all features of the cell switching into myofibroblasts, were assessed after administration of wild type more than ANXA1 Knock-Out EVs. Interestingly, we demonstrated a mechanism by which the ANXA1-EVs complex can stimulate the activation of formyl peptide receptors (FPRs), triggering mesenchymal switches and cell motility on both fibroblasts and endothelial cells. Therefore, we highlighted the importance of ANXA1/EVs-FPR axes in PC progression as a vehicle of intercommunication tumor cells-stroma, suggesting a specific potential prognostic/diagnostic role of ANXA1, whether in soluble form or even if EVs are captured in PC

Bioavailable Citrus sinensis extract: Polyphenolic composition and biological activity

Citrus plants contain large amounts of flavonoids with beneficial effects on human health. In the present study, the antioxidant and anti-inflammatory potential of bioavailable polyphenols from Citrus sinensis was evaluated in vitro and ex vivo, using the murine macrophages cell line J774A.1 and primary peritoneal macrophages. Following simulated gastro-intestinal digestion, the in vitro bioavailability of Citrus sinensis polyphenolic extract was assessed using the human cell line Caco-2 grown as monolayers on a transwell membrane. Data demonstrated a relative permeation of its compounds (8.3%). Thus, the antioxidant and anti-inflammatory effect of polyphenolic Citrus sinensis fraction (Cs) was compared to the bioavailable one (CsB). Results revealed that Citrus extract were able to reduce macrophages pro-inflammatory mediators, including nitric oxide, iNOS, COX-2 and different cytokines. Moreover, the effect of Citrus sinensis polyphenols was associated with antioxidant effects, such as a reduction of reactive oxygen species (ROS) and heme-oxygenase-1 (HO-1) increased expression. Our results provide evidence that the bioavailable polyphenolic constituents of the Citrus sinensis extract accumulate prevalently at intestinal level and could reach systemic circulation exerting their effect. The bioavailable fraction showed a higher anti-inflammatory and antioxidant potential compared to the initial extract, thus highlighting its potential nutraceutical value

Many-nodes/many-links spinfoam: the homogeneous and isotropic case

I compute the Lorentzian EPRL/FK/KKL spinfoam vertex amplitude for regular graphs, with an arbitrary number of links and nodes, and coherent states peaked on a homogeneous and isotropic geometry. This form of the amplitude can be applied for example to a dipole with an arbitrary number of links or to the 4-simplex given by the compete graph on 5 nodes. All the resulting amplitudes have the same support, independently of the graph used, in the large j (large volume) limit. This implies that they all yield the Friedmann equation: I show this in the presence of the cosmological constant. This result indicates that in the semiclassical limit quantum corrections in spinfoam cosmology do not come from just refining the graph, but rather from relaxing the large j limit.Comment: 8 pages, 4 figure