Solution of the two identical ion Penning trap final state

We have derived a closed form analytic expression for the asymptotic motion of a pair of identical ions in a high precision Penning trap. The analytic solution includes the effects of special relativity and the Coulomb interaction between the ions. The existence and physical relevance of such a final state is supported by a confluence of theoretical, experimental and numerical evidence.Comment: 5 pages and 2 figure

Plant response to irrigation with saline water in a Sicilian vineyard: results of a three-year field investigation

This paper reports the results of a three-year field investigation carried out in a vineyard located in Sicily (Mazara del Vallo, Trapani) within the framework of the Project: Evolution of cropping systems as affected by climate change (CLIMESCO). Research investigated soil-plant response to irrigation performed with water having two different salinity levels; soil hydrological characteristics, soil salinity, crop transpiration and stomatal conductance were measured in field plots. The results proved that crop transpiration and stomatal conductance were significantly affected by soil salinity conditions (expressed as electrical conductivity of the soil saturated water extract). A significant reduction in both the physiological parameters was observed in the treatment irrigated with water having higher salinity (electrical conductivity equal to 1.6 dS m–1) as compared to the treatment irrigated with water of lower salinity (electrical conductivity equal to 0.6 dS m–1)

Evaluation of the Free Energy of Two-Dimensional Yang-Mills Theory

The free energy in the weak-coupling phase of two-dimensional Yang-Mills theory on a sphere for SO(N) and Sp(N) is evaluated in the 1/N expansion using the techniques of Gross and Matytsin. Many features of Yang-Mills theory are universal among different gauge groups in the large N limit, but significant differences arise in subleading order in 1/N.Comment: 10 pages; no figures; LaTe

Influence of biochar on the physical, chemical and retention properties of an amended sandy soil

Soil porosity plays an important role in soil-water retention and water availability to crops, potentially affecting both agricultural practices and environmental sustainability. The pore structure controls fluid flow and transport through the soil, as well as the relationship between the properties of individual minerals and plants. Moreover, the anthropogenic pressure on soil properties has produced numerous sites with extensive desertification process close to residential areas. Biochar (biologically derived charcoal) is produced by pyrolysis of biomasses under low oxygen conditions, and it can be applied for recycling organic waste in soils and increase soil fertility, improving soil structure and enhancing soil water storage and soil water movement. Soil application of biochar might have agricultural, environmental and sustainability advantages over the use of organic manures or compost, as it is a porous material with a high inner surface area. The main objectives of the present study were to investigate the possible application of biochar from forest residues, derived from mechanically chipped trunks and large branches of Abies alba M., Larix decidua Mill., Picea excelsa L., Pinus nigra A. and Pinus sylvestris L. pyrolysed at 450 C for 48h, to improve soil structural and hydraulic properties (achieving a stabilization of soil). Different amount of biochar were added to a desertic sandy soil, and the effect on soil porosity water retention and water available to crops were investigated. The High Energy Moisture Characteristic (HEMC) technique was applied to investigate soil-water retention at high-pressure head levels. The adsorption and desorption isotherms of N2 on external surfaces were also determined in order to investigate micro and macro porosity ratio. Both the described model of studies on adsorption-desorption experiments with the applied isotherms model explain the increasing substrate porosity with a particular attention to the macro and micro porosity, respectively

Soil structure and bypass flwo processes in a Vertsol under sprinkler and drip irrigation.

In this paper morphological and physical characteristics, as well as flow behaviour of a Mediterranean Vertisol under the influence of two different irrigation systems currently used for irrigation, i.e. drip and sprinkler systems, were compared. No differences in soil texture, compaction and in potential cracking were found on cores from the two fields. However, field application of methylene blue showed the presence of continuous macropores, penetrating up to depths of 20-25 cm from the soil surface, in the field where the drip system was in use (field 1). This was considered to be the pre-existing soil structure. Instead, macropores terminating at a depth ranging between 5 and 10 cm from the soil surface were observed in the sprinkler irrigated field (field 2). The same difference in terms of macropores' continuity was also observed on soil cores sampled from the two irrigated fields. The higher raindrop impact and the non-point water application involved in the sprinkler irrigation system were assumed to have determined, during several years, the different depth of penetration of the macropores in the two fields. A different hydraulic behaviour was evidenced by laboratory measurement of bypass flow on soil cores taken from the two fields. Specifically, higher values of the saturated hydraulic conductivity were found in the cores from the drip irrigated field compared to those sampled in the sprinkler field. In addition no bypass flow was measured in the columns under the sprinkler field, while high rates and amounts of bypass flow were obtained in the cores taken from the drip irrigated field. The different hydraulic behaviour observed in the cores taken from the drip and from the sprinkler irrigated field was in agreement with the difference in terms of macropores' continuity between the two fields. Being bypass flow a mechanism inducing leaching of solutes, results of this investigation suggest that irrigation systems affecting soil structure, and altering macropores' continuity, should be avoided in clay soils. (c) 2006 Published by Elsevier B.

Irrigation practices affecting land degradation in Sicily

The available amount of fresh water for agriculture, and specifically for irrigation, is decreasing all over the world. The quality of irrigation water is deteriorating, and saline/sodic waters are increasingly used in many arid and semi-arid regions of the world. Salinization is closely associated with the process of desertification.Sustainable land management practices are urgently needed to preserve the production potential of agricultural land while safeguarding environmental quality. In cracking soils sustainable management should take into account the occurrence of bypass flow and the influence that land use may have on soil structure and bypass flow phenomena.Measurement of vertical and horizontal shrinkage in confined soil cores was found to be suitable for determining the Soil Shrinkage Characteristic Curve (SSCC) and for incorporating shrinkage in the soil hydraulic parameters/functions determined on confined undisturbed soil samples. An optimization procedure based on multi-step outflow experiments with inverse modelling was developed for determining the soil hydraulic characteristics (HC). The need for accounting for structural porosity and shrinkage processes was recognized on the basis of hydraulic conductivity values determined by the suction crust infiltrometer method and of the SSCC determined on confined soil cores.Analysis of the response of clay soils to ESP values up to 15, showed that the concept of critical threshold needs reconsideration, because increasing soil degradation upon increasing ESP appeared to be a continuum. A major hazard of deterioration of structural and hydraulic properties was recognized even at low ESP values (ESPThe relevance of bypass flow on the water balance in a Mediterranean climatic context as that occurring in Sicily, was evaluated by application of the FLOCR model. The results showed that bypass flow corresponded with about 70-74% of cumulative yearly rainfall, and that models not accounting for bypass flow may lead to a significant overprediction of crop evapotranspiration and underestimation of the hazard of land degradation and desertification.Results of bypass flow measurements performed in a Mediterranean cracking soil under alternated use of a high salinity solution to distilled water showed that exchange of solutes occurred at the contact surfaces between the macropores/cracks walls and the incoming solution in concomitance with bypass fluxes. These exchanges were effective in determining leaching of solutes and removal of Sodium, and in preventing salinization and sodification in part of the soil volume that is in contact with the roots.Combined use of morphometric and physical techniques made it possible to explore the effect of irrigation on soil structure and bypass flow phenomena of a Mediterranean cracking soil under two different irrigation systems, i.e. drip and micro-sprinkler. Different vertical distributions of cracks was found under the two irrigation systems. In agreement with these observations, different flow behaviour was observed in the laboratory in cylindrical soil cores taken from the irrigated micro-sprinkler field. No bypass flow or lower amounts of bypass flow in the micro-sprinkler irrigated field compared to the drip irrigation treatment. Chemical dispersion of clay particles and detachment of these particles from the surface and their movement into the cracks were the mechanisms responsible for the partial or total occlusion of the (macro) pores in the micro-sprinkler irrigated field.In conclusion, this study showed that drip irrigation alternatively using high and low salt water was most effective in maintaining the productive capacity of the clay soil being studied, particularly when this water was applied to a cracked soil. Combined use of morphometric and physical methods was necessary to understand the underlined highly dynamic flow behaviour in these complex soils.</p

Large-N Universality of the Two-Dimensional Yang-Mills String

We exhibit the gauge-group independence (``universality'') of all normalized non-intersecting Wilson loop expectation values in the large N limit of two-dimensional Yang-Mills theory. This universality is most easily understood via the string theory reformulation of these gauge theories. By constructing an isomorphism between the string maps contributing to normalized Wilson loop expectation values in the different theories, we prove the large N universality of these observables on any surface. The string calculation of the Wilson loop expectation value on the sphere also leads to an indication of the large N phase transition separating strong- and weak-coupling phases.Comment: 18 pages, phyzzx macro, no figure

Implementation of green harvesting in the Sicilian wine industry: Effects on the cooperative system

This paper contributes to assessing the effectiveness of the GH measure to contribute in reducing the supply of wine grapes, and thus contrasting the fall of wine prices in those years when especially abundant productions are expected. By analysing the application of this measure to the Sicilian wine sector during the three-year period (2010-2012), we assess its effects on the regional wine cooperative system. The results from the analysis of the statistical data show that the GH measure was successful in terms of the number of applications, the supported area and financial expenditures, and contributed with other factors to determining a reduction in wine grape production. The empirical survey shows that GH has been contributing to contrast the fall of wine prices in this region and helping the recovery of the wine market. However, an increase in operating costs as well as difficulties in the planning activities of the cooperatives has been recorded

Cathepsin D expression levels in nongynecological solid tumors: Clinical and therapeutic implications

Cathepsin D is a lysosomal acid proteinase which is involved in the malignant progression of breast cancer and other gynecological tumors. Clinical investigations have shown that in breast cancer patients cathepsin D overexpression was significantly correlated with a shorter free-time disease and overall survival, whereas in patients with ovarian or endometrial cancer this phenomenon was associated with tumor aggressiveness and a degree of chemoresistance to various antitumor drugs such as anthracyclines, cis-platinum and vinca alkaloids. Therefore, a lot of research has been undertaken to evaluate the role and the prognostic value of cathepsin D also in other solid neoplasms. However, conflicting results have been generated from these studies. The discrepancies in these results may, in part, be explained with the different methodological approaches used in order to determine the levels of expression of the enzyme in tumor tissues and body fluids. Further investigations using well-standardized techniques may better define the clinical significance of cathepsin D expression in solid tumors. Nevertheless, evidence emerging from these studies indicates that this proteinase seems to facilitate early phases of tumor progression such as cell proliferation and local dissemination. These findings support the concept that cathepsin D may be a useful marker for identifying patients with highly malignant tumor phenotypes who may need more aggressive clinical treatment; this enzyme may also be considered as a potential target for a novel therapeutic approach in the treatment of solid neoplasms

Modulation of NRF2/KEAP1 Signaling in Preeclampsia

Placentation is a key and tightly regulated process that ensures the normal development of the placenta and fetal growth. Preeclampsia (PE) is a hypertensive pregnancy-related disorder involving about 5–8% of all pregnancies and clinically characterized by de novo maternal hypertension and proteinuria. In addition, PE pregnancies are also characterized by increased oxidative stress and inflammation. The NRF2/KEAP1 signaling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. ROS activate NRF2, allowing its binding to the antioxidant response element (ARE) region present in the promoter of several antioxidant genes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase that neutralize ROS, protecting cells against oxidative stress damages. In this review, we analyze the current literature regarding the role of the NRF2/KEAP1 pathway in preeclamptic pregnancies, discussing the main cellular modulators of this pathway. Moreover, we also discuss the main natural and synthetic compounds that can regulate this pathway in in vivo and in vitro models