Employment Expectations and Gross Flows by Type of Work Contract

There is growing interest in understanding firms’ temporary and permanent employment practices and how institutional changes shape them. Using data on Spanish establishments, we examine: (a) how employers adjust temporary and permanent job and worker flows to prior employment expectations, and (b) how the 1994 and 1997 labour reforms promoting permanent employment affected establishments’ employment practices. Generally, establishments’ prior employment expectations are realized through changes in all job and worker flows. However, establishments uniquely rely on temporary hires as a buffer to confront diminishing long-run employment expectations. None of the reforms significantly affected establishments’ net temporary or permanent employment flows.http://deepblue.lib.umich.edu/bitstream/2027.42/40032/3/wp646.pd

Tachyonic preheating using 2PI-1/N dynamics and the classical approximation

We study the process of tachyonic preheating using approximative quantum equations of motion derived from the 2PI effective action. The O(N) scalar (Higgs) field is assumed to experience a fast quench which is represented by an instantaneous flip of the sign of the mass parameter. The equations of motion are solved numerically on the lattice, and the Hartree and 1/N-NLO approximations are compared to the classical approximation. Classical dynamics is expected to be valid, since the occupation numbers can rise to large values during tachyonic preheating. We find that the classical approximation performs excellently at short and intermediate times, even for couplings in the larger region currently allowed for the SM Higgs. This is reassuring, since all previous numerical studies of tachyonic preheating and baryogenesis during tachyonic preheating have used classical dynamics. We also compare different initializations for the classical simulations.Comment: 32 pages, 21 figures. Published version: Some details added, section added, references added, conclusions unchange

The generating function for a particular class of characters of SU(n)

We compute the generating function for the characters of the irreducible representations of SU(n) whose associated Young diagrams have only two rows with the same number of boxes. The result is a rational determinantal expression in which both the numerator and the denominator have a simple structure when expressed in terms of Schur polynomials.Comment: 7 pages, no figure

A multi-wavelength view of the central kiloparsec region in the Luminous Infrared Galaxy NGC1614

The Luminous Infrared Galaxy NGC1614 hosts a prominent circumnuclear ring of star formation. However, the nature of the dominant emitting mechanism in its central ~100 pc is still under debate. We present sub-arcsecond angular resolution radio, mid-infrared, Pa-alpha, optical, and X-ray observations of NGC1614, aimed at studying in detail both the circumnuclear ring and the nuclear region. The 8.4 GHz continuum emission traced by the Very Large Array (VLA) and the Gemini/T-ReCS 8.7 micron emission, as well as the Pa-alpha line emission, show remarkable morphological similarities within the star-forming ring, suggesting that the underlying emission mechanisms are tightly related. We used an HST/NICMOS Pa-alpha map of similar resolution to our radio maps to disentangle the thermal free-free and non-thermal synchrotron radio emission, from which we obtained the intrinsic synchrotron power-law for each individual region within the central kpc of NGC1614. The radio ring surrounds a relatively faint, steep-spectrum source at the very center of the galaxy, suggesting that the central source is not powered by an AGN, but rather by a compact (r < 90 pc) starburst. Chandra X-ray data also show that the central kpc region is dominated by starburst activity, without requiring the existence of an AGN. We also used publicly available infrared data to model-fit the spectral energy distribution of both the starburst ring and a putative AGN in NGC1614. In summary, we conclude that there is no need to invoke an AGN to explain the observed bolometric properties of the galaxy.Comment: 13 pages, 7 figures, 5 tables. Accepted for publication in Ap

Systemic Effects Induced by Hyperoxia in a Preclinical Model of Intra-abdominal Sepsis

Supplemental oxygen is a supportive treatment in patients with sepsis to balance tissue oxygen delivery and demand in the tissues. However, hyperoxia may induce some pathological effects. We sought to assess organ damage associated with hyperoxia and its correlation with the production of reactive oxygen species (ROS) in a preclinical model of intra-abdominal sepsis. For this purpose, sepsis was induced in male, Sprague-Dawley rats by cecal ligation and puncture (CLP). We randomly assigned experimental animals to three groups: control (healthy animals), septic (CLP), and sham-septic (surgical intervention without CLP). At 18 h after CLP, septic (n = 39), sham-septic (n = 16), and healthy (n = 24) animals were placed within a sealed Plexiglas cage and randomly distributed into four groups for continuous treatment with 21%, 40%, 60%, or 100% oxygen for 24 h. At the end of the experimental period, we evaluated serum levels of cytokines, organ damage biomarkers, histological examination of brain and lung tissue, and ROS production in each surviving animal. We found that high oxygen concentrations increased IL-6 and biomarkers of organ damage levels in septic animals, although no relevant histopathological lung or brain damage was observed. Healthy rats had an increase in IL-6 and aspartate aminotransferase at high oxygen concentration. IL-6 levels, but not ROS levels, are correlated with markers of organ damage. In our study, the use of high oxygen concentrations in a clinically relevant model of intra-abdominal sepsis was associated with enhanced inflammation and organ damage. These findings were unrelated to ROS release into circulation. Hyperoxia could exacerbate sepsis-induced inflammation, and it could be by itself detrimental. Our study highlights the need of developing safer thresholds for oxygen therapy

Probing highly obscured, self-absorbed galaxy nuclei with vibrationally excited HCN

We present high resolution (0."4) IRAM PdBI and ALMA mm and submm observations of the (ultra) luminous infrared galaxies ((U)LIRGs) IRAS17208-0014, Arp220, IC860 and Zw049.057 that reveal intense line emission from vibrationally excited ($\nu_2$=1) J=3-2 and 4-3 HCN. The emission is emerging from buried, compact (r<17-70 pc) nuclei that have very high implied mid-infrared surface brightness $>$$5\times 10^{13}$ L$_{\odot}$ kpc$^{-2}$. These nuclei are likely powered by accreting supermassive black holes (SMBHs) and/or hot (>200 K) extreme starbursts. Vibrational, $\nu_2$=1, lines of HCN are excited by intense 14 micron mid-infrared emission and are excellent probes of the dynamics, masses, and physical conditions of (U)LIRG nuclei when H$_2$ column densities exceed $10^{24}$ cm$^{-2}$. It is clear that these lines open up a new interesting avenue to gain access to the most obscured AGNs and starbursts. Vibrationally excited HCN acts as a proxy for the absorbed mid-infrared emission from the embedded nuclei, which allows for reconstruction of the intrinsic, hotter dust SED. In contrast, we show strong evidence that the ground vibrational state ($\nu$=0), J=3-2 and 4-3 rotational lines of HCN and HCO$^+$ fail to probe the highly enshrouded, compact nuclear regions owing to strong self- and continuum absorption. The HCN and HCO$^+$ line profiles are double-peaked because of the absorption and show evidence of non-circular motions - possibly in the form of in- or outflows. Detections of vibrationally excited HCN in external galaxies are so far limited to ULIRGs and early-type spiral LIRGs, and we discuss possible causes for this. We tentatively suggest that the peak of vibrationally excited HCN emission is connected to a rapid stage of nuclear growth, before the phase of strong feedback.Comment: 13 pages, 7 figures, accepted for publication in Astronomy and Astrophysic

ZrO2 Based materials as photocatalysts for 2-propanol oxidation by using UV and solar light irradiation and tests for CO2 reduction

Bare ZrO2, Ce doped ZrO2 and Er doped ZrO2 samples have been prepared by a hydrothermal process and have been used as photocatalysts for 2-propanol oxidation reaction in gas solid regime. Moreover, some preliminary tests have been carried out for CO2 reduction. The samples were physico-chemically characterized and both bare and doped ZrO2 based materials resulted active for oxidation and reduction reactions by using UV and solar irradiation. The reactivity results have been correlated with the compositional, structural and morphological features of the photocatalysts

Direct Access to Unnatural Cyclobutane ?-Amino Acids through Visible Light Catalyzed [2+2]-Cycloaddition

In this work, we report the first selective, photocatalyzed [2+2]-cycloaddition of dehydroamino acids with styrene-type olefins. This simple, mild, and scalable approach relies on the use of the triplet energy transfer catalyst [Ir(dFCF(3)ppy(2))dtbpy]PF6 under visible light irradiation and provides fast access to value-added substituted strained cyclobutane alpha-amino acid derivatives. © 2022 The Authors. Published by American Chemical Society

Leukocyte Associated Immunoglobulin Like Receptor 1 Regulation and Function on Monocytes and Dendritic Cells During Inflammation

Inhibitory receptors are crucial immune regulators and are essential to prevent exacerbated responses, thus contributing to immune homeostasis. Leukocyte associated immunoglobulin like receptor 1 (LAIR-1) is an immune inhibitory receptor which has collagen and collagen domain containing proteins as ligands. LAIR-1 is broadly expressed on immune cells and has a large availability of ligands in both circulation and tissues, implicating a need for tight regulation of this interaction. In the current study, we sought to examine the regulation and function of LAIR-1 on monocyte, dendritic cell (DC) and macrophage subtypes, using different in vitro models. We found that LAIR-1 is highly expressed on intermediate monocytes as well as on plasmacytoid DCs. LAIR-1 is also expressed on skin immune cells, mainly on tissue CD14(+) cells, macrophages and CD1c(+) DCs. In vitro, monocyte and type-2 conventional DC stimulation leads to LAIR-1 upregulation, which may reflect the importance of LAIR-1 as negative regulator under inflammatory conditions. Indeed, we demonstrate that LAIR-1 ligation on monocytes inhibits toll like receptor (TLR)4 and Interferon (IFN)-alpha- induced signals. Furthermore, LAIR-1 is downregulated on GM-CSF and IFN-gamma monocyte-derived macrophages and monocyte-derived DCs. In addition, LAIR-1 triggering during monocyte derived-DC differentiation results in significant phenotypic changes, as well as a different response to TLR4 and IFN-alpha stimulation. This indicates a role for LAIR-1 in skewing DC function, which impacts the cytokine expression profile of these cells. In conclusion, we demonstrate that LAIR-1 is consistently upregulated on monocytes and DC during the inflammatory phase of the immune response and tends to restore its expression during the resolution phase. Under inflammatory conditions, LAIR-1 has an inhibitory function, pointing toward to a potential intervention opportunity targeting LAIR-1 in inflammatory conditions

Genetic transfer of resistance to powdery mildew and of an associated molecular marker from Aegilops ventricosa to hexaploid wheat.

Resistance to powdery mildew, caused by the fungus Erysiphe graminis f.sp. tritici, has been transferred from Aegilops ventricosa (genomes DvMv) to hexaploid wheat (Triticum aestivum, ABD). In two transfer lines, H-93-8 and H-93-35, the resistance gene was linked to a gene encoding protein U-1, whereas one line, H-93-33, was resistant but lacked the molecular marker, and another line, H-93-1, was susceptible but carried the gene for U-1, indicating that the original Mv chromosome from Ae. ventricosa, carrying the two genes, had undergone recombination with a wheat chromosome in the last two lines