1,122 research outputs found
Generalized ArtinâMumford curves over finite fields
Let Fq be the finite field of order q=ph with p>2 prime and h>1, and let FqÂŻ be a subfield of Fq. From any two qÂŻ-linearized polynomials L1,L2âFâžq[T] of degree q, we construct an ordinary curve X(Ljavax.xml.bind.JAXBElement@3de21171,Ljavax.xml.bind.JAXBElement@44e73174) of genus g=(qâ1)2 which is a generalized ArtinâSchreier cover of the projective line P1. The automorphism group of X(Ljavax.xml.bind.JAXBElement@265fda03,Ljavax.xml.bind.JAXBElement@5ee20ea3) over the algebraic closure Fâžq of Fq contains a semidirect product ÎŁâÎ of an elementary abelian p-group ÎŁ of order q2 by a cyclic group Î of order qÂŻâ1. We show that for L1â L2, ÎŁâÎ is the full automorphism group Aut(X(Ljavax.xml.bind.JAXBElement@4b2f1fff,Ljavax.xml.bind.JAXBElement@2ddc4e9)) over Fâžq; for L1=L2 there exists an extra involution and Aut(X(Ljavax.xml.bind.JAXBElement@2daa9e77,Ljavax.xml.bind.JAXBElement@1c89ae0d))=ÎŁâÎ with a dihedral group Î of order 2(qÂŻâ1) containing Î. Two different choices of the pair L1,L2 may produce birationally isomorphic curves, even for L1=L2. We prove that any curve of genus (qâ1)2 whose Fâžq-automorphism group contains an elementary abelian subgroup of order q2 is birationally equivalent to X(Ljavax.xml.bind.JAXBElement@1301e61e,Ljavax.xml.bind.JAXBElement@61aac551) for some separable qÂŻ-linearized polynomials L1,L2 of degree q. We produce an analogous characterization in the special case L1=L2. This extends a result on the ArtinâMumford curves, due to Arakelian and KorchmĂĄros [1]
On maximal curves that are not quotients of the Hermitian curve
For each prime power â the plane curve Xâwith equation Yâ2â+1=Xâ2-X is maximal over Fâ6. Garcia and Stichtenoth in 2006 proved that X3is not Galois covered by the Hermitian curve and raised the same question for Xâwith â>3; in this paper we show that Xâis not Galois covered by the Hermitian curve for any â>3. Analogously, Duursma and Mak proved that the generalized GK curve Cânover Fâ2nis not a quotient of the Hermitian curve for â>2 and nâĽ5, leaving the case â=2 open; here we show that C2nis not Galois covered by the Hermitian curve over F22nfor nâĽ5
Complete (k,3)-arcs from quartic curves
Complete (Formula presented.) -arcs in projective planes over finite fields are the geometric counterpart of linear non-extendible Near MDS codes of length (Formula presented.) and dimension (Formula presented.). A class of infinite families of complete (Formula presented.) -arcs in (Formula presented.) is constructed, for (Formula presented.) a power of an odd prime (Formula presented.). The order of magnitude of (Formula presented.) is smaller than (Formula presented.). This property significantly distinguishes the complete (Formula presented.) -arcs of this paper from the previously known infinite families, whose size differs from (Formula presented.) by at most (Formula presented.)
CONVERGENCE OF SIGNALING BY INTERLEUKIN-3, GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR, AND MAST CELL GROWTH FACTOR ON JAK2 TYROSINE KINASE
Mast cell growth factor (MGF) (also called stem cell factor) synergizes with several lymphokines, including interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF), to promote proliferation and differentiation of certain hemopoietic progenitor cells. Although similar patterns of tyrosine-phosphorylated proteins characterize cells stimulated by MGF, IL-3, and GM-CSF, only the MGF receptor is a tyrosine kinase, and the heterodimeric receptors for IL-3 and GM-CSF share a common beta subunit that is devoid of enzymatic activity. Here we show that signaling pathways utilized by all three cytokines include the cytoplasmic tyrosine kinase JAK2. Analysis of several factor-dependent myeloid cell lines indicated that JAK2 is physically associated with the common beta subunit and with MGF receptor (c-Kit) even prior to ligand binding. However, each of the ligands induced elevated tyrosine phosphorylation of JAK2 and a consequent increase in its catalytic activity. These results demonstrate for the first time the convergence within the same myeloid cells of signaling pathways originating in two distinct lymphokine receptors and a tyrosine kinase receptor on activation of a cytoplasmic tyrosine kinase
Normal and five-fingered hand: comparative X-ray morphometry in the post-natal age
Background: Five-fingered hand (5-FH) with completely developed phalanges is a rare phenotype observed so far only in humans and characterised by three phalanges of the 1st ray. A long-lasting, debated question is if the missing element of the normal hand 1st ray is the metacarpal or the phalanx. In this study, comparative X-rays morphometry of long bones in normal and 5-FH is carried out with the aim to face this question through homology analysis of long bone segments in the transverse and longitudinal line of normal hand and 5-FH. Materials and methods: In the normal hand X-rays (n =20) and in a 5-FH X-rays series (n = 9) the relative length of each segment on the ray total length and the index of growth rate (IGR) were assessed. The calculation of the first parameter in normal hand bi-phalangeal thumb was carried out on the 3rd ray total length in the same hand. Results: The parameters of relative length and the proximal/distal growth rate asymmetry in the post-natal period (assessed through the IGR) confirmed in 5-FH the homology of all the five segment on the transverse line. In the normal control hand, the relative length assessment methodology was biased by the missing segment of the thumb, therefore, the reference to the 3rd ray total length in the same hand (instead of the 1st), allowed the homology analysis of the thumb metacarpal and 1st phalanx with the lateral segments (2ndâ5th ray) of the same hand. The 5-FH analysis was used to choose the more appropriate reference ray for the normal hand group. Conclusions: The comparative analysis of relative lengths and IGRs in the two groups suggested homology of the (anatomical) 1st metacarpal with the 2ndâ5th proximal phalanges in the same hand and that of the (anatomical) 1st proximal phalanx with the 2ndâ5th mid phalanges. These data suggest that the missing segment of the normal hand thumb is the metacarpal
WATER\u2013BUDGET AS A TOOL TO EVALUATE THE SUSTAINABLE USE OF GROUNDWATER RESOURCES (ISONZO PLAIN, NE ITALY)
Water budget, hydrogeology, SoÄa/Isonzo River, climate chang
Assessment and imaging of intracellular magnesium in saos-2 osteosarcoma cells and its role in proliferation
Magnesium is an essential nutrient involved in many important processes in living organ-isms, including protein synthesis, cellular energy production and storage, cell growth and nucleic acid synthesis. In this study, we analysed the effect of magnesium deficiency on the proliferation of SaOS-2 osteosarcoma cells. When quiescent magnesium-starved cells were induced to proliferate by serum addition, the magnesium content was 2â3 times lower in cells maintained in a medium without magnesium compared with cells growing in the presence of the ion. Magnesium depletion inhibited cell cycle progression and caused the inhibition of cell proliferation, which was associated with mTOR hypophosphorylation at Serine 2448. In order to map the intracellular magnesium distribution, an analytical approach using synchrotron-based X-ray techniques was applied. When cell growth was stimulated, magnesium was mainly localized near the plasma membrane in cells maintained in a medium without magnesium. In non-proliferating cells growing in the presence of the ion, high concentration areas inside the cell were observed. These results support the role of magnesium in the control of cell proliferation, suggesting that mTOR may represent an important target for the antiproliferative effect of magnesium. Selective control of magnesium availability could be a useful strategy for inhibiting osteosarcoma cell growth
Live Wire - A Low-Complexity Body Channel Communication System for Landmark Identification
This paper presents a robust simplex Body Channel Communication (BCC) system aimed at providing an interactive infrastructure solution for visually impaired people. Compared to existing BCC solutions, it provides high versatility, weara- bility and installability in an environment in a low complexity hardware-software solution. It operates with a ground referred transmitter (TX) and it is based on an asynchronous thresh- old receiver (RX) architecture. Synchronization, demodulation and packetizing and threshold control are completely software defined and implemented using MicroPython. The RX includes BluetoothÂŽ (BT) radio connectivity and a cell-phone application provides push text-to-speech notifications to a smartphone. The hardware achieves a Packet Error Rate (PER) of âź0.1 at 550 kHz pulse center frequency, Synchronized-On Off Keying (S- OOK) modulation and 1 kbps data rate, for an average current consumption of 44mA
Brief comments on three existing approaches for managing neonates at risk of early-onset sepsis
Background: Growing concerns regarding the adverse effects of antibiotics during the first days of life and the marked reduction in the incidence of early-onset sepsis (EOS) are changing the clinical practice for managing neonates at risk of EOS. Strategies avoiding unnecessary antibiotics while promoting mother-infant bonding and breastfeeding deserve to be considered. Main body: We compare strategies for managing newborns at risk of EOS recommended by the American Academy of Pediatrics, which are among the most followed recommendations worldwide. Currently three different approaches are suggested in asymptomatic full-term or late preterm neonates: i) the conventional management, based on standard perinatal risk factors for EOS alone, ii) the neonatal sepsis calculator, a multivariate risk assessment based on individualized, quantitative risk estimates (relying on maternal risk factors for EOS) combined with physical examination findings at birth and in the following hours and iii) an approach entirely based on newborn clinical condition (serial clinical observation) during the first 48 h of life. We discuss advantages and limitations of these approaches, by analyzing studies supporting each strategy. Approximately 40% of infants who develop EOS cannot be identified on the basis of maternal RFs or laboratory tests, therefore close monitoring of the asymptomatic but at-risk infant remains crucial. A key question is to know what proportion of babies with mild, unspecific symptoms at birth can be managed safely without giving antibiotics. Conclusions: Both neonatal sepsis calculator and serial clinical observation may miss cases of EOS, and clinical vigilance for all neonates is essential There is a need to assess which symptoms at birth are more predictive of EOS, and therefore require immediate interventions, or symptoms that can be carefully reevaluated without necessarily treat immediately the neonate with antibiotics. Studies comparing strategies for managing neonates are recommended
Interannual analysis of high spatially-resolved δ18O and δ2H data in precipitation across North-East Italy
Stable water isotopes are widely-used tracers to investigate hydrological processes occurring in the atmosphere and to determine the geospatial origin of water, i.e. to acquire useful information about the hydrological cycles over catchment basins and to find the origin of water recharging rivers, aquifers, and springs. Mapping the isotopic composition of precipitation provides hydrological and climate information at regional and global scales. However, the isotopic composition of precipitation is usually analyzed at large scales with a limited spatial resolution. In Italy, a few studies mapped the oxygen stable isotopes using annually-averaged data, not accounting for the strong seasonality of the isotopic composition linked to climatic and weather factors. To partially fill this gap, the present study proposes a detailed analysis of more than 2250 isotope data (δ18O, δ2H, and deuterium excess) related to precipitations collected in the Friuli Venezia Giulia (FVG) region (Italy) with monthly or seasonal frequency in 36 sites between 1984 and 2015.
The FVG region lies at the north-eastern end of Italy, bordering Austria in the North and Slovenia in the East, and extends over ~7.9¡103 km2. From a hydrogeological point of view, FVG is an interesting case study. Large highly-permeable carbonate aquifers are present in the Alps and Prealps, while the southern part of the region is characterized by an alluvial plain, split by the spring belt into two sectors: the High Plain in the North, characterized by an highly-permeable unconfined aquifer, and the Low Plain in the South, characterized by a system of confined and artesian aquifers. All the aquifers are recharged by the effective precipitations which in the FVG exhibits among the highest annual precipitation rates in Italy (with peaks >3000 mm/year).
For the present research, the isotopic data were used: (i) to analyze the spatial and seasonal variability of isotopic composition; (ii) to relate water isotopes with orography and weather parameters collected from meteorological stations as well as using ECMWF ERA5 reanalysis; (iii) to reconstruct the local meteoric water lines across the FVG at annual and seasonal bases; (iv) to quantify interannual trends and analyze their spatial distribution; and (iv) to model the spatial distribution of isotope content in precipitation and create annual and seasonal maps
- âŚ