49 research outputs found
Green-Lazarsfeld's Conjecture for Generic Curves of Large Gonality
We use Green's canonical syzygy conjecture for generic curves to prove that
the Green-Lazarsfeld gonality conjecture holds for generic curves of genus g,
and gonality d, if .Comment: 5 page
Reduced resonance schemes and Chen ranks
The resonance varieties are cohomological invariants that are studied in a
variety of topological, combinatorial, and geometric contexts. We discuss their
scheme structure in a general algebraic setting and introduce various
properties that ensure the reducedness of the associated projective resonance
scheme. We prove an asymptotic formula for the Hilbert series of the associated
Koszul module, then discuss applications to vector bundles on algebraic curves
and to Chen ranks formulas for finitely generated groups, with special emphasis
on K\"ahler and right-angled Artin groups.Comment: 34 page
Higher resonance schemes and Koszul modules of simplicial complexes
Each connected graded, graded-commutative algebra of finite type over a
field of characteristic zero defines a complex of finitely generated,
graded modules over a symmetric algebra, whose homology graded modules are
called the (higher) Koszul modules of . In this note, we investigate the
geometry of the support loci of these modules, called the resonance schemes of
the algebra. When is the exterior
Stanley-Reisner algebra associated to a finite simplicial complex , we
show that the resonance schemes are reduced. We also compute the Hilbert series
of the Koszul modules and give bounds on the regularity and projective
dimension of these graded modules. This leads to a relationship between
resonance and Hilbert series that generalizes a known formula for the Chen
ranks of a right-angled Artin group.Comment: 16 page
Surgical treatment of biliary tract malformations in children
Clinica Chirurgie şi Ortopedie Pediatrică, UMF „Gr.T.Popa”, Departamentul Anatomie Patologică, Spitalul Clinic de Urgenţe pentru Copii “Sfânta Maria”, Iaşi, România,
Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Rezumat: Tratamentul chirurgical al colestazei neonatale este cel mai bine ilustrat în două condiţii patologice particulare:
atrezia de căi biliare şi chistul congenital de coledoc. A trecut aproximativ un secol de la prima tentativă de tratament chirurgical
al colestazei la copil. Etiologia şi patologia acestor două condiţii rămân în continuare în mare masură o enigmă. Prima
intervenţie chirurgicală specifică dedicată corecţiei atreziei biliare a fost efectuată de Morio Kasai în anul 1959, la Universitatea
Sendai. Actualmente, tratamentul chirurgical atât al atreziei, cât şi al chistului congenital de coledoc sunt bine definite:
portoenterostomia Kasai, respectiv excizia chistului congenital de coledoc şi refacerea circuitului digestiv prin
hepaticoenteroanastomoză pe ansă în Y a la Roux. Din păcate, rezultatele mai puțin favorabile ale portoenterostomiei obligă la
transplant hepatic ca ultimă soluţie pentru creşterea supravieţuirii la distanţă a acestor pacienţi. Actuala prezentare este o
trecere în revistă a definirii termenilor referitori la obstacolul în scurgerea biliară determinând colestaza, a modalităţilor de
diagnostic şi tratament accesibile autorilor, expunerea experienţei personale privind managementul acestor cazuri.Summary: Surgical treatment of neonatal cholestasis is best illustrated in two particular pathologic conditions: biliary atresia
and congenital choledochal cyst. Almost a century passed since the first attempts of treating children’s cholestasis were
undergone. The ethiology and pathology of these conditions were also poorly understood. The first surgical intervention
specifically designed for the correction of biliary atresia was described by Morio Kasai in 1959.In the present time, the surgical
treatment of both biliary atresia and congenital choledochal dilatation are well established: Kasai’s portoenterostomy and,
accordingly, cyst excision and Roux-en-Y hepaticojejunostomy. Unfortunately, the overall poor results after portoenterostomy
make liver transplantation an ultimate and mandatory solution for the long-term survival of the patients. This paper aims to
define the terms regarding biliary outflow obstruction causing cholestasis, different diagnostic and therapeutical modalities
accesible to the autors, exposing the personal experience in the management of congenital biliary tract malformations
Syzygies of torsion bundles and the geometry of the level l modular variety over M_g
We formulate, and in some cases prove, three statements concerning the purity
or, more generally the naturality of the resolution of various rings one can
attach to a generic curve of genus g and a torsion point of order l in its
Jacobian. These statements can be viewed an analogues of Green's Conjecture and
we verify them computationally for bounded genus. We then compute the
cohomology class of the corresponding non-vanishing locus in the moduli space
R_{g,l} of twisted level l curves of genus g and use this to derive results
about the birational geometry of R_{g, l}. For instance, we prove that R_{g,3}
is a variety of general type when g>11 and the Kodaira dimension of R_{11,3} is
greater than or equal to 19. In the last section we explain probabilistically
the unexpected failure of the Prym-Green conjecture in genus 8 and level 2.Comment: 35 pages, appeared in Invent Math. We correct an inaccuracy in the
statement of Prop 2.
The ALICE experiment at the CERN LHC
ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008
Prediction of rye dough behaviour and bread quality using response surface methodology
peer-reviewedBread making is a hydro-thermal process; therefore, knowing the behaviour of the
main constituents of the flour at different temperatures allows control of the quality of
the end-product. Mixing and thermal characteristics were studied using the Mixolab
system and response surface methodology was used to investigate the influence of particle
size distribution of the flour, pH and the addition of hemicellulase enzyme on the
thermo-mechanical behaviour of the whole rye flour and on bread quality. A central
composite face-centered design, with two levels of fineness modulus (1.78 and 1.26),
two levels of pH (6.5 and 3.8) and three levels of added enzyme (0, 50 and 100 mg/kg
of flour), was used. The results indicated that thermo-mechanical variables – water
absorption, development time, dough stability, protein weakening, starch gelatinization,
starch gelling and cooling setback – as well as bread quality are influenced by the
three factors investigated.
Significant correlations were found between water absorption and pH, enzyme level,
fineness modulus and their interactions. Dough stability was significantly influenced
by all the independent variables, as well as by the interaction between pH and fineness
modulus. Starch gelling and cooling setback were influenced by the interaction between
pH and enzyme level. Concerning bread quality, both porosity and specific volume were
affected by enzyme level and pH, as well as by the interaction between fineness modulus
and enzyme level