819 research outputs found
Calibration of evolutionary diagnostics in high-mass star formation
The evolutionary classification of massive clumps that are candidate
progenitors of high-mass young stars and clusters relies on a variety of
independent diagnostics based on observables from the near-infrared to the
radio. A promising evolutionary indicator for massive and dense
cluster-progenitor clumps is the L/M ratio between the bolometric luminosity
and the mass of the clumps. With the aim of providing a quantitative
calibration for this indicator we used SEPIA/APEX to obtain CH3C2H(12-11)
observations, that is an excellent thermometer molecule probing densities >
10^5 cm^-3 , toward 51 dense clumps with M>1000 solar masses, and uniformly
spanning -2 < Log(L/M) < 2.3.
We identify three distinct ranges of L/M that can be associated to three
distinct phases of star formation in massive clumps. For L/M <1 no clump is
detected in CH3C2H , suggesting an inner envelope temperature below 30K. For 1<
L/M < 10 we detect 58% of the clumps, with a temperature between 30 and 35 K
independently from the exact value of L/M; such clumps are building up
luminosity due to the formation of stars, but no star is yet able to
significantly heat the inner clump regions. For L/M> 10 we detect all the
clumps, with a gas temperature rising with Log(L/M), marking the appearance of
a qualitatively different heating source within the clumps; such values are
found towards clumps with UCHII counterparts, suggesting that the quantitative
difference in T - L/M behaviour above L/M >10 is due to the first appearance of
ZAMS stars in the clumps.Comment: Astrophysical Journal Letters, Accepte
Fusion channels of non-Abelian anyons from angular-momentum and density-profile measurements
We present a method to characterize non-Abelian anyons that is based only on
static measurements and that does not rely on any form of interference. For
geometries where the anyonic statistics can be revealed by rigid rotations of
the anyons, we link this property to the angular momentum of the initial state.
We test our method on the paradigmatic example of the Moore-Read state, that is
known to support excitations with non-Abelian statistics of Ising type. As an
example, we reveal the presence of different fusion channels for two such
excitations, a defining feature of non-Abelian anyons. This is obtained by
measuring density-profile properties, like the mean square radius of the system
or the depletion generated by the anyons. Our study paves the way to novel
methods for characterizing non-Abelian anyons, both in the experimental and
theoretical domains.Comment: 6+10 pages, 2+3 figures -- revised text and Supp. Mat. -- to be
published in Phys. Rev. Let
Assessing the aesthetic attractivity of European butterflies: A web-based survey protocol
Aesthetic attractivity stands as an underestimated yet fundamental feature of species in conservation biology, significantly driving disproportionate protection efforts towards charismatic species. Despite the evidence, few attempts sought to precisely quantify the impact of aesthetic attractivity in defining priority of species for conservation actions (e.g. inclusion in International Union for Conservation of Nature red lists and protection lists). This study protocol describes the setting of an online test (available from April 2022 to April 2023 at www.unveiling.eu) designed to i) quantify the aesthetic attractivity to humans of the 496 European butterfly species and ii) identify which features (both in the perceived animal and in the perceiver) influence the aesthetic attractivity of a given butterfly species. The test is divided in 5 sections (personal data, ranking, single morphological features, emotional engagement, dispositional variables) aimed at profiling the relation each participant has with the species examined. In the long-term, evaluating butterflies' aesthetic attractivity could facilitate the critical assessment of current conservation strategies, such as the process of selection of flag and umbrella species by research institutions, environmental associations and Non Governative Organizations. This is expected to provide the much-needed evidence to set up unbiased biodiversity conservation strategies and counteract the selective anthropogenic pressure which favours the extinction of unattractive species, being no or less protected compared to charismatic species
Radiomics and Artificial Intelligence Can Predict Malignancy of Solitary Pulmonary Nodules in the Elderly
Solitary pulmonary nodules (SPNs) are a diagnostic and therapeutic challenge for thoracic surgeons. Although such lesions are usually benign, the risk of malignancy remains significant, particularly in elderly patients, who represent a large segment of the affected population. Surgical treatment in this subset, which usually presents several comorbidities, requires careful evaluation, especially when pre-operative biopsy is not feasible and comorbidities may jeopardize the outcome. Radiomics and artificial intelligence (AI) are progressively being applied in predicting malignancy in suspicious nodules and assisting the decision-making process. In this study, we analyzed features of the radiomic images of 71 patients with SPN aged more than 75 years (median 79, IQR 76–81) who had undergone upfront pulmonary resection based on CT and PET-CT findings. Three different machine learning algorithms were applied—functional tree, Rep Tree and J48. Histology was malignant in 64.8% of nodules and the best predictive value was achieved by the J48 model (AUC 0.9). The use of AI analysis of radiomic features may be applied to the decision-making process in elderly frail patients with suspicious SPNs to minimize the false positive rate and reduce the incidence of unnecessary surgery
HoBi-Like Pestivirus and Its Impact on Cattle Productivity
The clinical features and economic impact of the infection caused by an emerging group of pestiviruses, namely HoBi-like pestivirus, in a cattle herd of southern Italy are reported. In 2011, the virus was first associated with respiratory disease, causing an abortion storm after 1 year and apparently disappearing for the following 3 years after persistently infected calves were slaughtered. However, in 2014, reproductive failures and acute gastroenteritis were observed in the same herd, leading to a marked decrease of productivity. A HoBi-like strain closely related to that responsible for previous outbreaks was detected in several animals. Application of an intensive eradication programme, based on the detection and slaughtering of HoBi-like pestivirus persistently infected animals, resulted in a marked improvement of the productive performances
Synthesis and characterization of calcium hydroxide obtained from agave bagasse and investigation of its antibacterial activity
ABSTRACT
Calcium hydroxide (Ca(OH)2) is recognized as an efficient bactericide and is widely
applied as a root canal filler in endodontic treatment. Ca(OH)2 is mainly produced by
hydration of calcium oxide (CaO), a product of the thermal decomposition of calcium
carbonate (CaCO3) from sources such as limestone. In this work, calcium hydroxide
particles were synthetized by the thermochemical transformation of waste biomass
from the tequila industry. Agave biomass processed at 600 °C was composed mostly
of calcium carbonate (CaCO3), while calcination at 900 °C followed by hydration
produced Ca(OH)2. The morphology and crystalline nature of the Ca(OH)2 particles
were characterized by micro-Raman spectroscopy, scanning electron microscopy and
X-ray diffraction analysis. Bactericidal activity of synthesized calcium hydroxide was
evaluated with the agar diffusion assay. Our results provide evidence that Ca(OH)2
obtained from agave biomass is an effective bactericidal against Escherichia coli and
Enterococcus faecalis. Biomass from agave is available in Mexico and the rest of
the American continent, the use of processed bagasse for medical applications could
provide a venue for the useful disposition of industrial waste.
Palabras clave: recursos renovables, ceniza, bactericida, Ca(OH)2
RESUMEN
El hidrĂłxido de calcio (Ca(OH)2) es reconocido como un eficiente bactericida y es
ampliamente utilizado como relleno de la raĂz dental en tratamientos de endodoncia.
El Ca(OH)2 es producido por la hidrataciĂłn del Ăłxido de calcio (CaO), un producto de
la descomposición térmica del carbonato de calcio (CaCO3), obtenido principalmente
de piedra caliza. En el presente trabajo, se sintetizaron partĂculas de hidrĂłxido de calcio
mediante la descomposición térmica de biomasa residual de la industria tequilera. La
biomasa de agave se procesó a 600 °C, la cual se compone principalmente de carbonato
de calcio (CaCO3), por lo que su calcinación a 900 °C y posterior hidratación producen
el Ca(OH)2. La morfologĂa y cristalinidad de las partĂculas de Ca(OH)2 se caracterizaron mediante el uso de espectroscopĂa Raman, microscopio electrĂłnico de barrido
y difracciĂłn de rayos X. La actividad bactericida del hidrĂłxido de calcio obtenido, se
evaluĂł mediante el ensayo de difusiĂłn en agar. Los resultados proveen evidencia de
la efectividad del Ca(OH)2, obtenido de la biomasa de agave, contra Escherichia coli
y Enterococcus faecalis. La biomasa de agave se encuentra ampliamente disponible
en MĂ©xico y el resto del continente americano, por lo que el uso de bagazo de agave
procesado en aplicaciones médicas, puede proveer una alternativa en la disposición y
el uso de residuos agroindustriales
Unstructured citizen science reduces the perception of butterfly local extinctions: the interplay between species traits and user effort
The detection of local extinctions is often hindered by the lack of long-term monitoring schemes, and thus relies on time series of presence data. Recently, citizen science has repeatedly shown its value in documenting species occurrences. We investigated the effectiveness of unstructured citizen science records in reducing the perception of local extinctions in butterfly populations across Italian National Parks. We addressed three research questions: (i) the ability of citizen science data to supplement existing knowledge to complete time series of occurrences, (ii) the impact on data collection of three species features (species size, distribution and length of flight period) determining their appearance, and (iii) the interplay between participant effort and species appearance in the amount of diversity recorded on the iNaturalist platform. Our analysis of 98,922 records of Italian butterflies (39,929 from literature and 58,993 from iNaturalist of which 7427 from National Parks) showed that the addition of iNaturalist data filled many recent gaps in time series, thus reducing the perception of potential local extinctions. Records from more engaged users encompassed a higher fraction of local biodiversity and were more likely to reduce the perception of local extinctions. User effort strongly interacted with species features in determining the frequency of records for individual species. In particular, more engaged users were less affected by species size. We provided updated butterfly checklists for Italian National Parks and a R package to calculate potential extinction upon time series. These results offer guidance for protected areas, conservationists, policymakers, and citizen scientists to optimize monitoring of local populations
MicroRNA control of podosome formation in vascular smooth muscle cells in vivo and in vitro
PDGF enhances podosome formation and cell migration by regulating expression of the microRNAs miR-143 and -145, which target PDGF-R, PKC-ε, and fascin
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