Periods of Double EPW-sextics

We study the indeterminacy locus of the period map for double EPW-sextics. We recall that double EPW-sextics are parametrized by lagrangian subspaces of the third wedge-product of a 6-dimensional complex vector-space. The indeterminacy locus is contained in the set of lagrangians containing a decomposable vector. The projectivization of the 3-dimensional support of such a decomposable vector contains a degeneracy subscheme which is either all of the plane or a sextic curve. We show that the period map is regular on any lagrangian A such that for all decomposables in A the corresponding degeneracy subscheme is a GIT-semistable sextic curve whose closure (in the semistable locus) does not contain a triple conic.Comment: We added a proof that the the period map of double EPW-sextics with isolated singularities is an open embedding into the complement of four explicit arithmetic divisors in the period space. Gave precise references to results of "Moduli of double EPW-sextics" (latest arXiv version) which will appear in Memoirs of the AM

Moduli of sheaves and the Chow group of K3 surfaces

Let X be a projective complex K3 surface. Beauville and Voisin singled out a 0-cycle c_X on X of degree 1: it is represented by any point lying on a rational curve in X. Huybrechts proved that the second Chern class of a rigid simple vector-bundle on X is a multiple of the Beauville-Voisin class c_X if certain hypotheses hold and he conjectured that the additional hypotheses are unnecessary. We believe that the following generalization of Huybrechts' conjecture holds. Let M and N be moduli spaces of stable pure sheaves on X (with fixed cohomological Chern characters) and suppose that they have the same dimension: then the set whose elements are second Chern classes of sheaves parametrized by the closure of M (in the corresponding moduli spaces of semistable sheaves) is equal to the set whose elements are second Chern classes of sheaves parametrized by the closure of N after a translation by a suitable multiple of c_X (so that degrees match). We will prove that the above statement holds under some additional assumptions.Comment: Deleted a footnote and replaced it by a sentence in the main body of the pape

Food Acceptability, Menu Fatigue, and Aversion on ISS Missions

The acceptability of the spaceflight food system has been linked to caloric intake and associated nutritional benefits. The diets of the United States Operating Segment crewmembers during a mission are restricted to 200 processed and prepackaged standard menu items supplemented with personal preference foods. ISS crew members have noted in debriefs that they would prefer more food variety for the length of the missions and they tire of certain foods over six months. It is possible that menu fatigue leads to decreases in acceptability and increased aversion to available foods, potentially contributing to the body mass loss often experienced by ISS crew. However, the impact of repeat food consumption on acceptability within the current spaceflight food system has not yet been systematically investigated. Limited variety and crew preferences within food categories may have more severe physical and behavioral health and performance consequences as mission duration increases. Characterizing the relationship between food acceptability and mission duration will contribute to defining requirements for an acceptable food system that will support crew health and performance on long duration missions

An Improvement of the Pivoting Strategy in the Bunch and Kaufman Decomposition, Within Truncated Newton Methods

In this work we consider the solution of large scale (possibly nonconvex) unconstrained optimization problems. We focus on Truncated Newton methods which represent one of the commonest methods to tackle such problems. In particular, we follow the approach detailed in Caliciotti et al. (Comput Optim Appl 77:627-651, 2020), where a modified version of the Bunch and Kaufman decomposition (Bunch and Kaufman, Math Comput 31:163-179, 1977) is proposed for solving the Newton equation. Such decomposition is used within SYMMBK routine as proposed by Chandra (Conjugate gradient methods for partial differential equations, Ph.D. thesis, Yale University, New Haven, 1978; see also Conn et al., Trust-Region Methods, MPS-SIAM Series on Optimization, Philadelphia, PA, 2000; HSL: A collection of Fortran codes for large scale scientific computation, https://www.hsl.rl.ac.uki ; Marcia, Appl Numer Math 58(4):449-458, 2008) for iteratively solving symmetric possibly indefinite linear systems. The proposal in Caliciotti et al. (Comput Optim Appl 77:627-651, 2020) enabled to overcome a relevant drawback of nonconvex problems, namely the computed search direction might not be gradient-related. Here we propose further extensions of such approach, aiming at improving the pivoting strategy of the Bunch and Kaufman decomposition and enhancing its flexibility

Angiotensin type-2 (AT-2)-receptor activation reduces renal fibrosis in cyclosporine nephropathy: evidence for blood-pressure independent effect

Compound 21 (C21), selective agonist of AT2 receptors, shows antinflammatory effects in hypertension and nephroprotection in diabetes. The aim of this study was to evaluate the effects of C21 in cyclosporine nephropathy, which is characterized mainly by tubulo-interstitial fibrosis. Ten days before and during the experimental periods, low-salt diet was administered to Sprague Dawley rats. Cyclosporine-A (15mg/kg/day, i.p.) and cyclosporine-A plus C21 (0.3 mg/kg /day, i.p) were administered for 1 and 4 weeks. Control groups was left without any treatment. Blood pressure (plethysmographic method) and 24 hour albuminuria were measured once a week. At the end of the experiments, the kidneys were excised for histomorphometric analysis of renal fibrosis and for immunohistochemical evaluation of inflammatory infiltrates and type I and IV collagen expression.After 1 and 4 weeks, the rats treated with cyclosporine showed a significant increase (p <0.01) in blood pressure, no significant changes in albuminuria, a significant increase (p <0.01) in glomerular and tubulo-interstitial fibrosis and inflammatory infiltrates as compared to the control rats. Treatment with C21 did not modify the cyclosporine dependent increase of blood pressure, which was higher than in control rats, but after 4 weeks of treatment significantly reduced (p <0.01) glomerular and tubulo-interstitial fibrosis, type 1 collagen expression and macrophage infiltration, as compared to rats treated with cyclosporine.The administration of C21 showed a protective effect on cyclosporine nephropathy, decreasing renal fibrosis and macrophage infiltration. These data suggest that C21 may counteract tubulo-interstitial fibrosis, the most potent predictor of the progression of renal diseases

Measurement of Cosmic Ray spectrum and Anisotropy with ARGO-YBJ

In this paper we report on the observation of the anisotropy of cosmic ray arrival direction at different angular scales with ARGO-YBJ. Evidence of new few-degree excesses throughout the sky region 195$^{\circ}\leq$ R.A. $\leq$ 315$^{\circ}$ is presented for the first time. We report also on the measurement of the light-component (p+He) spectrum of primary cosmic rays in the range 5 - 200 TeV.Comment: Invited talk to the 3rd Galileo - Xu Guangqi meeting, October 11-15, 2011 Beijing (China

New combinations for two hybrids in Salvia subg. Rosmarinus (Lamiaceae)

New combinations for two hybrids in Salvia subg. Rosmarinus (Lamiaceae

Solvent Extraction of Cadmium(II) with Benzoyltrifluoroacetone in the Presence of Certain Auxiliary Ligands

Extraction of cadmium(II) from aqueous acetate buffered media with benzoyltrifluoroacetone (BTA) in benzene has been studied with and without the addition of auxiliary ligands like pyridine (PY), 3-methylpyridine (3MP), 4-methylpyridine (4MP), pyridine N-oxide (PO), 2-methylpyridine N-oxide (2MPO), 4-methylpyridine N-oxide (4MPO), tributylphosphate (TBP) and trioctylphosphine oxide (TOPO). Synergistic enhancement was observed in all systems. Extraction constants and adduct forma ti on constants have been calculated. Adduct formation constants increase in the following order