High-order Time Expansion Path Integral Ground State

The feasibility of path integral Monte Carlo ground state calculations with very few beads using a high-order short-time Green's function expansion is discussed. An explicit expression of the evolution operator which provides dramatic enhancements in the quality of ground-state wave-functions is examined. The efficiency of the method makes possible to remove the trial wave function and thus obtain completely model-independent results still with a very small number of beads. If a single iteration of the method is used to improve a given model wave function, the result is invariably a shadow-type wave function, whose precise content is provided by the high-order algorithm employed.Comment: 4 page

The Effect of Different Oversown Legume Species and Row Spacings Upon the Production of Degraded Cultivated Pastures

The establishment and growth of three leguminous plants Medicago sativa (A), Trifolium pratense (TR) and Lotus corniculatus (LC) was analysed. They were oversown on three different row spacings (10, 20 y 40 cm) on September 12, 1994. Density was estimated by marking and sequential counting of seedlings. Growth was estimated from Leaf Area Index (LAI) and from forage accumulation per area unit on three dates: D1 = 26/01/95; D2 = 11/04/95; D3 = 5/12/95. Total forage accumulation was higher (p\u3c0.05) for the treatments oversown with TR in D1 at the smaller distances (average from 10 and 20 cm, 4130 kg DM/ha, 46% higher than treatment control (C); all the other treatments did not differ from C). In D2 there were no differences between treatments (average 1995 kg DM/ha); in D3 there were no differences among the oversown treatments (average 2498 kg DM/ha) and forage accumulation was 59% higher than C. There was no difference in seedling density between oversown legumes A and TR but both were higher (p\u3c0.05) than that of LC. The relationship between the LAI of the oversown legume and that of the vegetation present was higher (p\u3c0.05) for TR than for the rest of the treatments: D1, TR=1.43, A=0.21, LC=0.1; D2, TR=1.62, A=0.31, LC=0.2 and D3, TR=1.91, A=0.86, LC=1.05 . It is concluded that it is feasible to increase yield and modify botanical composition of degraded pastures by oversowing legumes

Martensitic Thin Wires under Restrained Recovery: Theoretical and Experimental Aspects

A one-dimensional model for the evolution of microstructure in single crystal shape memory wires has been recently proposed in (Rizzoni (2011)). The model is based on the constrained theory of martensite introduced by (Ball et al. (1995); De Simone and James (2002)) and on the assumption that stable equilibrium configurations are deformations lying at the energy wells on most parts of the wire. In this paper we compare the response simulated for restrained recovery conditions (Rizzoni (2011)) with experimental data obtained in restrained recovery tests performed on NiTi wires. As an application, we consider a truss made of shape memory wires and rigid elements, and we calculate its deformation after thermal activation of the shape recovery

Antimutagenic and antioxidant activity of a protein fraction from aerial parts of Urtica dioica

Abstract Context: Urtica dioica L. (Urticaceae), stinging nettle, has been employed as a folklore remedy for a wide spectrum of ailments, including urinary disorders, prostatic hyperplasia, and liver diseases. It has been also used traditionally for cancer treatment. Object: To evaluate the potential chemopreventive properties of a protein fraction from the aerial part of Urtica dioica (namely UDHL30). Materials and methods: UDHL30 has been tested for the antimutagenic activity in bacteria (50-800 μg/plate; Ames test by the preincubation method) and for the cytotoxicity on human hepatoma HepG2 cells (0.06-2 mg/mL; 24 and 48 h incubation). Moreover, the antioxidant activity of UDHL30 (0.1-1200 μg/mL; ABTS and superoxide-radical scavenger assays) was evaluated as potential protective mechanisms. Results: UDHL30 was not cytotoxic on HepG2 cells up to 2 mg/mL; conversely, it exhibited a strong antimutagenic activity against the mutagen 2-aminoanthracene (2AA) in all strains tested (maximum inhibition of 56, 78, and 61% in TA98, TA100, and WP2uvrA strains, respectively, at 800 μg/plate). In addition, a remarkable scavenging activity against ABTS radical and superoxide anion (IC50 values of 19.9 ± 1.0 μg/mL and 75.3 ± 0.9 μg/mL, respectively) was produced. Discussion and conclusions: UDHL30 possesses antimutagenic and radical scavenging properties. Being 2AA a pro-carcinogenic agent, we hypothesize that the antimutagenicity of UDHL30 can be due to the inhibition of CYP450-isoenzymes, involved in the mutagen bioactivation. The radical scavenger ability could contribute to 2AA-antimutagenicity. These data encourage further studies in order to better define the potential usefulness of UDHL30 in chemoprevention

Ground state properties of a dilute homogeneous Bose gas of hard disks in two dimensions

The energy and structure of a dilute hard-disks Bose gas are studied in the framework of a variational many-body approach based on a Jastrow correlated ground state wave function. The asymptotic behaviors of the radial distribution function and the one-body density matrix are analyzed after solving the Euler equation obtained by a free minimization of the hypernetted chain energy functional. Our results show important deviations from those of the available low density expansions, already at gas parameter values $x\sim 0.001$. The condensate fraction in 2D is also computed and found generally lower than the 3D one at the same $x$.Comment: Submitted to PRA. 7 pages and 8 figure

La coltura della Reseda Biondella. Un primato nell'area di Mutina?

The Ex Cassa di Risparmio site is a reclaimed channel - first Imperial age - located in the center of the city of Modena and it is unique in Emilia Romagna for the archaeobotanical information provided on urban area. The study of seeds/fruits remains produced a framework which can be considered representative for reconstructing the vegetal environment of Mutina at the moment of maximum splendor of the Roman empire and of the city; some species appeared particularly worthy of insights, such as weld - Reseda luteola L., grass species that produces a very stable yellow pigment used since ancient times for dyeing fabrics like wool, linen and silk. The abundance of seeds found in the drained canal suggests agricultural practices implemented in peri-urban area of the city and presumably related to the economy of this prosperous Roman colony. Agriculture should have been a strong element of its economy in addition to ceramic production, sheep farming and the textile industry

Effect of Nitrogen Fertilization Upon Spring Growth in Thinopyrum Poticum in Alkaline Soils. Argentina

Wheatgrass is a perennial forage grass adapted to low fertility alkaline soils in the Flooding pampa. It has an annual forage growth cycle characterised by a high spring-summer concentration and low values in winter. The objective of this study was to assess that it is possible to anticipate and increase forage growth and DM production of wheatgrass pastures applying nitrogen fertilization. The experiment was carried out at the Balcarce Experimental Station from 28/08/95 to 04/12/95. Using a completely randomized block design the effects of 6 levels of N: 0, 50, 100, 150, 200 and 250 kg Nha-1, added as NO3 NH4 were evaluated. The highest forage accumulation was reached with N250 with no differences (p\u3e0,05) with N200 and N150, showing a threefold increase in forage accumulation when compared with N0. A decreasing increment in forage accumulation was obtained with increasing N doses and the highest was with N50 and the lowest with N250 (43 kg DM and 17 kg DM/kg N applied respectively). The results show that nitrogen fertilization can increase and anticipate forage growth and DM production of wheatgrass pastures in late winter and early spring

Effect of Nitrogen Fertilization Upon Winter Growth in Natural Pastures of the South East of Buenos Aires Province, Argentina

The effect of winter nitrogen fertilization upon herbage accumulation during the winter-spring period on a natural pasture of the Flooding Pampa dominated by cool season annual (Lolium multiflorum) and perennial (Stipa neesiana) grasses was evaluated. The experiment was carried out from August to November in 1994 and 1995. Fertilization treatments were: 0, 50, 100, 150, 200 and 250 kgN ha- 1 (N0, N50, N100, N150, N200 and N250, respectively). The experimental plots were set out in three randomized blocks. In 1994, maximum forage accumulation was reached at N150, and no significant differences were found among N150, N200 and N250. In 1995, N250 showed the highest yield. No differences were found between N200 and N150, both being significantly higher than the rest of the treatments. In both years N0 showed the lowest forage yield. Though a 50% rainfall deficit during 1995 delayed forage growth initiation as compared to 1994, no significant differences in the total herbage accumulated in both years were registered