23 research outputs found
CBRN Threats and the Economic Analysis of Terrorism
The aim of this paper is to investigate the economic aspects of CBRN threats. For this purpose, the extent to which this topic is reflected in freely-accessible academic literature and the costs associated with such threats will be assessed. Furthermore, it is to be determined which industries have a particular interest in security against such CBRN threats.
ALMA reveals a chemically evolved submillimeter galaxy at z=4.76
The chemical properties of high-z galaxies provide important information to
constrain galaxy evolutionary scenarios. However, widely-used metallicity
diagnostics based on rest-frame optical emission lines are not usable for
heavily dust-enshrouded galaxies (such as Sub-Millimeter Galaxies; SMGs),
especially at z>3. Here we focus on the flux ratio of the far-infrared
fine-structure emission lines [NII]205um and [CII]158um to assess the
metallicity of high-z SMGs. Through ALMA cycle 0 observations, we have detected
the [NII]205um emission in a strongly [CII]-emitting SMG, LESS J033229.4-275619
at z=4.76. The velocity-integrated [NII]/[CII] flux ratio is 0.043 +/- 0.008.
This is the first measurement of the [NII]/[CII] flux ratio in high-z galaxies,
and the inferred flux ratio is similar to the ratio observed in the nearby
universe (~0.02-0.07). The velocity-integrated flux ratio and photoionization
models suggest that the metallicity in this SMG is consistent with solar,
implying the chemical evolution has progressed very rapidly in this system at
z=4.76. We also obtain a tight upper limit on the CO(12-11) transition, which
translates into CO(12-11)/CO(2-1) <3.8 (3 sigma). This suggests that the
molecular gas clouds in LESS J033229.4-275619 are not affected significantly by
the radiation field emitted by the AGN in this system.Comment: 5 pages, 3 figures, accepted for publication in Astronomy and
Astrophysics Letter
Resolved Neutral Outflow from a Lensed Dusty Star Forming Galaxy at z=2.09
We report the detection of a massive neutral gas outflow in the z=2.09
gravitationally lensed Dusty Star-Forming Galaxy HATLASJ085358.9+015537
(G09v1.40), seen in absorption with the OH+(1_1-1_0) transition using spatially
resolved (0.5"x0.4") Atacama Large Millimeter/submillimeter Array (ALMA)
observations. The blueshifted OH+ line is observed simultaneously with the
CO(9-8) emission line and underlying dust continuum. These data are
complemented by high angular resolution (0.17"x0.13") ALMA observations of
CH+(1-0) and underlying dust continuum, and Keck 2.2 micron imaging tracing the
stellar emission. The neutral outflow, dust, dense molecular gas and stars all
show spatial offsets from each other. The total atomic gas mass of the observed
outflow is 6.7x10^9 M_sun, >25% as massive as the gas mass of the galaxy. We
find that a conical outflow geometry best describes the OH+ kinematics and
morphology and derive deprojected outflow properties as functions of possible
inclination (0.38 deg-64 deg). The neutral gas mass outflow rate is between
83-25400 M_sun/yr, exceeding the star formation rate (788+/-300 M_sun/yr) if
the inclination is >3.6 deg (mass-loading factor = 0.3-4.7). Kinetic energy and
momentum fluxes span 4.4-290x10^9 L_sun and 0.1-3.7x10^37 dyne, respectively
(energy-loading factor = 0.013-16), indicating that the feedback mechanisms
required to drive the outflow depend on the inclination assumed. We derive a
gas depletion time between 29 and 1 Myr, but find that the neutral outflow is
likely to remain bound to the galaxy, unless the inclination is small, and may
be re-accreted if additional feedback processes do not occur.Comment: 33 pages, 20 figure
Deep observations of CO line emission from star-forming galaxies in a cluster candidate at z=1.5
We report results from a deep Jansky Very Large Array (JVLA) search for CO
1-0 line emission from galaxies in a candidate galaxy cluster at z~1.55 in the
COSMOS field. We target 4 galaxies with optical spectroscopic redshifts in the
range z=1.47-1.59. Two of these 4 galaxies, ID51613 and ID51813, are nominally
detected in CO line emission at the 3-4 sigma level. We find CO luminosities of
2.4x10^10 K km/s pc^2 and 1.3x10^10 K km/s pc^2, respectively. Taking advantage
from the clustering and 2-GHz bandwidth of the JVLA, we perform a search for
emission lines in the proximity of optical sources within the field of view of
our observations. We limit our search to galaxies with K<23.5 (AB) and
z_phot=1.2-1.8. We find 2 bright optical galaxies to be associated with
significant emission line peaks (>4 sigma) in the data cube, which we identify
with the CO line emission. To test the reliability of the line peaks found, we
performed a parallel search for line peaks using a Bayesian inference method.
Monte Carlo simulations show that such associations are statistically
significant, with probabilities of chance association of 3.5% and 10.7% for ID
51207 and ID 51380, respectively. Modeling of their optical/IR SEDs indicates
that the CO detected galaxies and candidates have stellar masses and SFRs in
the range (0.3-1.1)x10^11 M_sun and 60-160 M_sun/yr, with SFEs comparable to
that found in other star-forming galaxies at similar redshifts. By comparing
the space density of CO emitters derived from our observations with the space
density derived from previous CO detections at z~1.5, and with semi-analytic
predictions for the CO luminosity function, we suggest that the latter tend to
underestimate the number of CO galaxies detected at high-redshift. Finally, we
argue about the benefits of future blind CO searches in clustered fields with
upcoming submm/radio facilities.Comment: Accepted for publication in MNRAS. Abstract has been slightly
shortened compared to original pdf versio
Extracellular vesicles in human skin: cross-talk from senescent fibroblasts to keratinocytes by miRNAs
Extracellular vesicles (EVs) and their miRNA cargo are intercellular communicators transmitting their pleiotropic messages between different cell types, tissues, and body fluids. Recently, they have been reported to contribute to skin homeostasis and were identified as members of the senescence-associated secretory phenotype of human dermal fibroblasts. However, the role of EV-miRNAs in paracrine signaling during skin aging is yet unclear. Here we provide evidence for the existence of small EVs in the human skin and dermal interstitial fluid using dermal open flow microperfusion and show that EVs and miRNAs are transferred from dermal fibroblasts to epidermal keratinocytes in 2D cell culture and in human skin equivalents. We further show that the transient presence of senescent fibroblast derived small EVs accelerates scratch closure of epidermal keratinocytes, whereas long-term incubation impairs keratinocyte differentiation in vitro. Finally, we identify vesicular miR-23a-3p, highly secreted by senescent fibroblasts, as one contributor of the EV-mediated effect on keratinocytes in in vitro wound healing assays. To summarize, our findings support the current view that EVs and their miRNA cargo are members of the senescence-associated secretory phenotype and, thus, regulators of human skin homeostasis during aging
Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study
Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk
Methanol adsorption on Si(100)2x1 investigated by high-resolution photoemission
The adsorption of methanol on Si(100)2 x 1 has been investigated at room temperature by high-resolution synchrotron radiation photoemission in the exposure range: 0.01-0.15 L. A combined evidence for a dissociative mechanism has been obtained from the analysis of the photoemission spectral features, which shows the absence of the ionization peak mainly based on the bond in the valence band and the identification of a Si-O related component in the Si 2p core spectrum after adsorption. The line-shape analysis of the Si 2p core level shows the rising of two surface-related components upon adsorption. Their energy location allows for the assignment to Si-H and Si-OCH3 bonds, as resulting from the interaction of the molecular fragments (H atom and methoxy group) with the surface. The growth of the Si-H and Si OCH3 related spectral components upon adsorption has been followed by a careful curve-fitting of the Si 2p line. The intensity increase of the new adsorption-induced components almost completely parallels the progressive intensity decrease of the surface dimer components, as found by the relative quantitative analysis of the Si2p peak components, The analysis of the C 1s photoemission core-line suggests that no C-O bond rupture occurs at low exposure. A further fragmentation of the CH3O - group occurs at higher exposure (>20 L), as we previously found for methanol adsorption on Si(111)7x7
Resolved Neutral Outflow from a Lensed Dusty Star-forming Galaxy at z = 2.09
33 pages, 20 figuresInternational audienceWe report the detection of a massive neutral gas outflow in the z=2.09 gravitationally lensed Dusty Star-Forming Galaxy HATLASJ085358.9+015537 (G09v1.40), seen in absorption with the OH+(1_1-1_0) transition using spatially resolved (0.5"x0.4") Atacama Large Millimeter/submillimeter Array (ALMA) observations. The blueshifted OH+ line is observed simultaneously with the CO(9-8) emission line and underlying dust continuum. These data are complemented by high angular resolution (0.17"x0.13") ALMA observations of CH+(1-0) and underlying dust continuum, and Keck 2.2 micron imaging tracing the stellar emission. The neutral outflow, dust, dense molecular gas and stars all show spatial offsets from each other. The total atomic gas mass of the observed outflow is 6.7x10^9 M_sun, >25% as massive as the gas mass of the galaxy. We find that a conical outflow geometry best describes the OH+ kinematics and morphology and derive deprojected outflow properties as functions of possible inclination (0.38 deg-64 deg). The neutral gas mass outflow rate is between 83-25400 M_sun/yr, exceeding the star formation rate (788+/-300 M_sun/yr) if the inclination is >3.6 deg (mass-loading factor = 0.3-4.7). Kinetic energy and momentum fluxes span 4.4-290x10^9 L_sun and 0.1-3.7x10^37 dyne, respectively (energy-loading factor = 0.013-16), indicating that the feedback mechanisms required to drive the outflow depend on the inclination assumed. We derive a gas depletion time between 29 and 1 Myr, but find that the neutral outflow is likely to remain bound to the galaxy, unless the inclination is small, and may be re-accreted if additional feedback processes do not occur
Extended Lyman- emission towards the SPT2349-56 protocluster at
Context. Deep spectroscopic surveys with the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed that some of the brightest infrared sources in the sky correspond to concentrations of dusty star-forming galaxies (DSFG) at high redshift. Among these, the SPT2349-56 protocluster system at z = 4.304 is amongst the most extreme examples due to its high source density and integrated star formation rate. Aims. We conducted a deep Lyman- line emission survey around SPT2349-56 using the Multi-Unit Spectroscopic Explorer (MUSE) at Very Large Telescope (VLT) in order to characterize this uniquely dense environment. Methods. Taking advantage of the deep three-dimensional nature of this survey, we performed a sensitive search for Lyman- emitters (LAEs) toward the core and northern extension of the protocluster, which correspond to the brightest infrared regions in this field. Using a smoothed narrowband image extracted from the MUSE datacube around the protocluster redshift, we searched for possible extended structures. Results. We identify only three LAEs at z = 4.3 in this field, in concordance with expectations for blank-fields, and an extended Lyman- structure spatially associated with core of the protocluster. All the previously-identified DSFGs in this field are undetected in Lyman- emission, consistent with the conspicuous dust obscuration in these systems. We find an extended Lyman- structure, about kpc in size, and located 56 kpc west of the protocluster core. Three DSFGs coincide spatially with the location of this structure. We conclude that either the three co-spatial DSFGs or the protocluster core itself are feeding ionizing photons to the Lyman- structure