610 research outputs found
Diverse strategies for copper production in Chalcolithic Iberia
Our understanding of early copper metallurgy in the Iberian Peninsula is mostly based on analysis from well-studied regions in the Southeast and Southwest. This paper focuses on two recently recovered Chalcolithic metallurgical assemblages outside these traditional research foci: two slagged crucibles from Lugar Viejo III (Zaragoza) and two large slag cakes from Cueva del Cañaveralejo (Córdoba). Analysis of the compositions and microstructures of the artifacts using optical microscopy and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) suggests they are related to primary copper production, namely smelting in crucible-furnaces under relatively oxidizing conditions, as is standard for this period. The slag layers on crucibles from Lugar Viejo indicate the production of copper with minor amounts of arsenic, also typical for this period. Of special note is the use of organic temper in the crucibles from Lugar Viejo, a practice found at the nearby site of Moncín but rare at other sites in Iberia. However, the slags from Cueva del Cañaveralejo are atypical in their large size (approx. 125 g each), fayalitic composition, unusual efficiency as demonstrated by a low copper content, and lack of arsenic; furthermore, the high sulfur content raises the possibility of the use of sulfidic ores. Results from both sites are compared against published data from well-known sites such as Los Millares, Las Pilas, Almizaraque, and Bauma del Serrat del Pont. The new data from Lugar Viejo and Cueva del Cañaveralejo reinforce the interpretation of metallurgy in the Iberian Peninsula as a low-skilled, conservative technology but also indicate the need for more research into regional variations. (See Supplementary Data 1 for a summary in Spanish)
LoCuSS: Luminous infrared galaxies in the merging cluster Abell 1758 at z=0.28
We present the first galaxy evolution results from the Local Cluster
Substructure Survey (LoCuSS), a multi-wavelength survey of 100 X-ray selected
galaxy clusters at 0.15<z<0.30. LoCuSS combines far-UV through far-IR
observations of cluster galaxies with gravitational lensing analysis and X-ray
data to investigate the interplay between the hierarchical assembly of clusters
and the evolution of cluster galaxies. Here we present new panoramic
Spitzer/MIPS 24micron observations of the merging cluster Abell 1758 at z=0.279
spanning 6.5x6.5Mpc and reaching a 90% completeness limit of 400uJy. We
estimate a global cluster SFR of 910\pm320 M_sun/yr within 3 Mpc of the cluster
centre, originating from 42 galaxies with L_IR > 5x10^10 L_sun. The obscured
activity in A1758 is therefore comparable with that in Cl 0024+1654, the most
active cluster previously studied at 24um. The obscured galaxies faithfully
trace the cluster potential as revealed by the weak-lensing mass map of the
cluster, including numerous mass peaks at R~2-3Mpc that are likely associated
with infalling galaxy groups and filamentary structures. However the core
(R<500kpc) of A1758N is 2x more active in the IR than that of A1758S, likely
reflecting differences in the recent dynamical history of the two clusters. The
24micron results from A1758 therefore suggest that dust-obscured cluster
galaxies are common in merging clusters and suggests that obscured activity in
clusters is triggered by both the details of cluster-cluster mergers and
processes that operate at larger radii including those within in-falling
groups. Our ongoing far-UV through far-IR observations of a large sample of
clusters should allow us to disentangle the different physical processes
responsible for triggering obscured star formation in clusters.Comment: 13 pages, 9 figures. Accepted for publication in MNRA
Euclid preparation. XXVI. The Euclid Morphology Challenge: Towards structural parameters for billions of galaxies
The various Euclid imaging surveys will become a reference for studies of galaxy morphology by delivering imaging over an unprecedented area of 15 000 square degrees with high spatial resolution. In order to understand the capabilities of measuring morphologies from Euclid-detected galaxies and to help implement measurements in the pipeline of the Organisational Unit MER of the Euclid Science Ground Segment, we have conducted the Euclid Morphology Challenge, which we present in two papers. While the companion paper focusses on the analysis of photometry, this paper assesses the accuracy of the parametric galaxy morphology measurements in imaging predicted from within the Euclid Wide Survey. We evaluate the performance of five state-of-the-art surface-brightness-fitting codes, , , , and , on a sample of about 1.5 million simulated galaxies (350 000 above 5σ) resembling reduced observations with the Euclid VIS and NIR instruments. The simulations include analytic Sérsic profiles with one and two components, as well as more realistic galaxies generated with neural networks. We find that, despite some code-specific differences, all methods tend to achieve reliable structural measurements (< 10% scatter on ideal Sérsic simulations) down to an apparent magnitude of about I = 23 in one component and I = 21 in two components, which correspond to a signal-to-noise ratio of approximately 1 and 5, respectively. We also show that when tested on non-analytic profiles, the results are typically degraded by a factor of 3, driven by systematics. We conclude that the official Euclid Data Releases will deliver robust structural parameters for at least 400 million galaxies in the Euclid Wide Survey by the end of the mission. We find that a key factor for explaining the different behaviour of the codes at the faint end is the set of adopted priors for the various structural parameters
Design and analysis of cross vaults along history
The history of cross vaults began almost 2,000 years ago with a widespread use during the Middle Ages and Renaissance, becoming nowadays one of the most diffused and fascinating structural typologies of the European building cultural heritage. However, conversely to the undeniable excellence achieved by the ancient masons, the structural behavior of these elements is still at the center of the scientific debate. In this regard, with the aim of reviewing the knowledge on this subject as a concise and valuable support for researchers involved in conservation of historical buildings, with a focus on design rules and structural analysis, the present study firstly introduces the cross vaults from a historical perspective, by describing the evolution of the main geometrical shapes together with basic practical rules used to size them. Then, the article deals with the subsequent advancements in structural analysis methods of vaults, until the development of modern limit analysis.This work was partially carried out under the program "Dipartimento di Protezione Civile - Consorzio RELUIS", signed on 2013-12-27.info:eu-repo/semantics/publishedVersio
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context
Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
Dwarf Galaxies in the Coma Cluster: II. Spectroscopic and Photometric Fundamental Planes
We present a study of the fundamental plane, FP, for a sample of 71 dwarf
galaxies in the core of Coma cluster in magnitude range .
Taking advantage of high resolution DEIMOS spectrograph on Keck II for
measuring the internal velocity dispersion of galaxies and high resolution
imaging of HST/ACS, which allows an accurate surface brightness modeling, we
extend the fundamental plane (FP) of galaxies to 1 magnitude fainter
luminosities than all the previous studies of the FP in Coma cluster. We find
that, the scatter about the FP depends on the faint-end luminosity cutoff, such
that the scatter increases for fainter galaxies. The residual from the FP
correlates with the galaxy colour, with bluer galaxies showing larger residuals
from FP.
We find in F814W-band indicating that in faint
dwarf ellipticals, the ratio is insensitive to the mass. We find that
less massive dwarf ellipticals are bluer than their brighter counterparts,
possibly indicating ongoing star formation activity. Although tidal encounters
and harassment can play a part in removing stars and dark matter from the
galaxy, we believe that the dominant effect will be the stellar wind associated
with the star formation, which will remove material from the galaxy resulting
in larger ratios. We attribute the deviation of a number of faint blue
dwarfs from the FP of brighter ellipticals to this effect.
We also study other scaling relations involving galaxy photometric properties
including the photometric plane. We show that, compared to the FP, the scatter
about the photometric plane is smaller at the faint end.Comment: 19 pages, 12 figures and 4 tables. Accepted for publication in
Monthly Notices of the Royal Astronomical Society Main Journal. (ref.
MN-11-0266-MJ.R1) Accepted 2011 October 10. Received 2011 September 13; in
original form 2011 February
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images
Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images
of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumorinfiltrating lymphocytes (TILs) based on H&E images from 13 TCGA tumor types. These TIL
maps are derived through computational staining using a convolutional neural network trained to
classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and
correlation with overall survival. TIL map structural patterns were grouped using standard
histopathological parameters. These patterns are enriched in particular T cell subpopulations
derived from molecular measures. TIL densities and spatial structure were differentially enriched
among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial
infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic
patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for
the TCGA image archives with insights into the tumor-immune microenvironment
- …