137 research outputs found
A traceological and quantitative assessment of the function of the bone bi-pointed tools from the Late Neolithic of the Cueva del Toro (Antequera, Malaga)
This study presents a traceological analysis of bi-pointed bone tools from the Late Neolithic layers of Cueva del Toro (MaÌlaga, Spain). The tools, previously hypothesized as arrowheads, were re-examined using traceological methods combined with confocal microscopy. The analysis refutes their classification as hunting implements. Polished surfaces on the tools, indicative of interaction with fibrous materials, suggest their use in weaving tasks involving wool or similar materials. This study highlights the early use of sheep wool for textiles at Cueva del Toro, dated between 4250 and 3950 cal BCE. This study also emphasizes the significance of craft activities in the Neolithic, with a diverse toolkit for processing fibers and animal materials. By applying quantitative methods to distinguish use-wear traces, the study contributes to the development of use-wear analysis techniques and opens the way for future research in ancient human-material interactions
The asteroseismic ground-based observational counterpart of CoRoT
We present different aspects of the ground-based observational counterpart of
the CoRoT satellite mission. We give an overview of the selected asteroseismic
targets, the numerous instruments and observatories involved, and the first
scientific results.Comment: 3 pages, 2 tables, 1 figure, to be published in the conference
proceedings 'Stellar Pulsation: Challenges for Theory and Observation' (31
May - 5 June, Santa Fe, New Mexico, US), publishers: American Institute of
Physic
New family of myrmecophilic spiders.
24 pages : illustrations (some color), maps (some color) ; 26 cm.The new genus and species Myrmecicultor chihuahuensis RamĂrez, Grismado, and Ubick is described and proposed as the type of the new family, Myrmecicultoridae RamĂrez, Grismado, and Ubick. The species is ecribellate, with entelegyne genitalia, two tarsal claws, without claw tufts, and the males have a retrolateral palpal tibial apophysis. Some morphological characters suggest a possible relationship with Zodariidae or Prodidomidae, but the phylogenetic analysis of six markers from the mitochondrial (12S rDNA, 16S rDNA, cytochrome oxidase subunit I) and nuclear (histone H3, 18S rDNA, 28S rDNA) genomes indicate that M. chihuahuensis is a separate lineage emerging near the base of the Dionycha and the Oval Calamistrum clade. The same result is obtained when the molecular data are combined with a dataset of morphological characters. Specimens of M. chihuahuensis were found associated with three species of harvester ants, Pogonomyrmex rugosus, Novomessor albisetosis, and Novomessor cockerelli, and were collected in pitfall traps when the ants are most active. The known distribution spans the Big Bend region of Texas (Presidio, Brewster, and Hudspeth counties), to Coahuila (Cuatro CiĂ©negas) and Aguascalientes (TepezalĂĄ), Mexico
A Multi-Analytical study of Rock Paintings from Leandro 5 Megalithic Barrow, North-Weastern Portugal
The colourant composition of a northern Portugal megalithic barrow decorated with âsolarâ motifs was studied using a multi-analytical approach, allowing the characterisa- tion of the painting techniques, pigments and binders. The red pigment was prepared with iron oxide minerals, using vegetal oils as organic additives, while the black pigment was char- coal without any organic additives or binders. The solar motif was first drawn with charcoal and subsequently painted with a red pigment.The work was supported by UID/QUI/50006/2019 with
funding from FCT/MCTES through national funds. CĂ©sar
Oliveira acknowledges Instituto de CiĂȘncias e Tecnologias
AgrĂĄrias e Agro-Alimentares, Porto (ICETA), for his contract
under project NORTE-01-0145-FEDER-000011. This work
was also developed under the project âFunerary and ceremonial practices between the Neolithic and the Bronze Age approached by archaeometryâ (ARQUEOM/Project-Sept2014)
Single-Molecule Identification of the Isomers of a Lipidic Antibody Activator
Molecular structural elucidation can be accomplished by different techniques, such as nuclear magnetic resonance or X-ray diffraction. However, the former does not give information about the three-dimensional atomic arrangement, and the latter needs crystallizable solid samples. An alternative is direct, real-space visualization of the molecules by cryogenic scanning tunneling microscopy (STM). This technique is usually limited to thermally robust molecules because an annealing step is required for sample deposition. A landmark development has been the coupling of STM with electrospray deposition (ESD), which smooths the process and widens the scope of the visualization technique. In this work, we present the on-surface characterization of air-, light-, and temperature-sensitive rhamnopolyene with relevance in molecular biology. Supported by theoretical calculations, we characterize two isomers of this flexible molecule, confirming the potential of the technique to inspect labile, non-crystallizable compounds
Planck intermediate results. VIII. Filaments between interacting clusters
About half of the baryons of the Universe are expected to be in the form of
filaments of hot and low density intergalactic medium. Most of these baryons
remain undetected even by the most advanced X-ray observatories which are
limited in sensitivity to the diffuse low density medium. The Planck satellite
has provided hundreds of detections of the hot gas in clusters of galaxies via
the thermal Sunyaev-Zel'dovich (tSZ) effect and is an ideal instrument for
studying extended low density media through the tSZ effect. In this paper we
use the Planck data to search for signatures of a fraction of these missing
baryons between pairs of galaxy clusters. Cluster pairs are good candidates for
searching for the hotter and denser phase of the intergalactic medium (which is
more easily observed through the SZ effect). Using an X-ray catalogue of
clusters and the Planck data, we select physical pairs of clusters as
candidates. Using the Planck data we construct a local map of the tSZ effect
centered on each pair of galaxy clusters. ROSAT data is used to construct X-ray
maps of these pairs. After having modelled and subtracted the tSZ effect and
X-ray emission for each cluster in the pair we study the residuals on both the
SZ and X-ray maps. For the merging cluster pair A399-A401 we observe a
significant tSZ effect signal in the intercluster region beyond the virial
radii of the clusters. A joint X-ray SZ analysis allows us to constrain the
temperature and density of this intercluster medium. We obtain a temperature of
kT = 7.1 +- 0.9, keV (consistent with previous estimates) and a baryon density
of (3.7 +- 0.2)x10^-4, cm^-3. The Planck satellite mission has provided the
first SZ detection of the hot and diffuse intercluster gas.Comment: Accepted by A&
Risk of tuberculosis after initiation of antiretroviral therapy among persons with HIV in Europe
Objectives: Tuberculosis (TB) risk after initiation of antiretroviral treatment (ART) is not well described in a European setting, with an average TB incidence of 25/105 in the background population. Methods: We included all adult persons with HIV starting ART in the RESPOND cohort between 2012 and 2020. TB incidence rates (IR) were assessed for consecutive time intervals post-ART initiation. Risk factors for TB within 6 months from ART initiation were evaluated using Poisson regression models. Results: Among 8441 persons with HIV, who started ART, 66 developed TB during 34,239 person-years of follow-up (PYFU), corresponding to 1.87/10 0 0 PYFU (95% confidence interval [CI]: 1.47-2.37). TB IR was highest in the first 3 months after ART initiation (14.41/10 0 0 PY (95%CI 10.08-20.61]) and declined at 3-6, 6-12, and > 12 months post-ART initiation (5.89 [95%CI 3.35-10.37], 2.54 [95%CI 1.36-4.73] and 0.51 [95%CI 0.30-0.86]), respectively. Independent risk factors for TB within the first 6 months after ART initiation included follow-up in Northern or Eastern Europe region, African origin, baseline CD4 count < 200 cells/mm(3), HIV RNA > 100,000 copies/mL, injecting drug use , heterosexual transmission. Conclusions: TB IR was highest in the first 3 months post-ART initiation and was associated with baseline risk factors, highlighting the importance of thorough TB risk assessment at ART initiation. (c) 2024 The Author(s). Published by Elsevier Ltd on behalf of International Society for Infectious Diseases
Planck intermediate results: III. the relation between galaxy cluster mass and Sunyaev-Zeldovich signal
We examine the relation between the galaxy cluster mass M and Sunyaev-Zeldovich (SZ) effect signal DA2 Y500 for a sample of 19 objects for which weak lensing (WL) mass measurements obtained from Subaru Telescope data are available in the literature. Hydrostatic X-ray masses are derived from XMM-Newton archive data, and the SZ effect signal is measured from Planck all-sky survey data. We find an MWL-D A2 Y500 relation that is consistent in slope and normalisation with previous determinations using weak lensing masses; however, there is a normalisation offset with respect to previous measures based on hydrostatic X-ray mass-proxy relations. We verify that our SZ effect measurements are in excellent agreement with previous determinations from Planck data. For the present sample, the hydrostatic X-ray masses at R500 are on average ~ 20 percent larger than the corresponding weak lensing masses, which is contrary to expectations. We show that the mass discrepancy is driven by a difference in mass concentration as measured by the two methods and, for the present sample, that the mass discrepancy and difference in mass concentration are especially large for disturbed systems. The mass discrepancy is also linked to the offset in centres used by the X-ray and weak lensing analyses, which again is most important in disturbed systems. We outline several approaches that are needed to help achieve convergence in cluster mass measurement with X-ray and weak lensing observations. © ESO, 2013
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