142 research outputs found
On the calibration of the relation between geometric albedo and polarimetric properties for the asteroids
We present a new extensive analysis of the old problem of finding a
satisfactory calibration of the relation between the geometric albedo and some
measurable polarization properties of the asteroids. To achieve our goals, we
use all polarimetric data at our disposal. For the purposes of calibration, we
use a limited sample of objects for which we can be confident to know the
albedo with good accuracy, according to previous investigations of other
authors. We find a new set of updated calibration coefficients for the
classical slope - albedo relation, but we generalize our analysis and we
consider also alternative possibilities, including the use of other
polarimetric parameters, one being proposed here for the first time, and the
possibility to exclude from best-fit analyzes the asteroids having low albedos.
We also consider a possible parabolic fit of the whole set of data.Comment: Accepted by MNRA
Dynamic spillovers between stock and money markets in Nigeria: A VARMA-GARCH approach
This study examines probable dynamic spillover transmissions between the Nigerian stock and money markets using the multivariate volatility framework that simultaneously accounts for both returns and shock spillovers. Based on relevant pre-tests, the VARMA-CCC-GARCH framework is selected and consequently employed to model the spillovers. The study finds significant cross-market return and shock spillovers between the two markets. Thus, a shock to one market is more likely to spill over to the other market. It is also observed that shocks have persistent effects on stock market volatility but transitory effects on money market volatility. In other words, shocks to the money market die out over time while shocks to stock market tend to persist over time. In addition, including lagged own shocks and lagged own conditional variance when forecasting the future volatility of both return series may enhance their forecast performance. An alternative approach proposed by Diebold and Yilmaz (2012) is also employed for robustness and the results are consistent with those obtained from the VARMA-CCC-GARCH model
The first confirmation of V-type asteroids among the Mars crosser population
The Mars crossing region constitutes a path to deliver asteroids from the
Inner Main Belt to the Earth crossing space. While both the Inner Main Belt and
the population of Earth crossing asteroids contains a significant fraction of
asteroids belonging to the V taxonomic class, only two of such V-type asteroids
has been detected in the Mars crossing region up to now. In this work, we
searched for asteroids belonging to the V class among the population of Mars
crossing asteroids, in order to support alternative paths to the delivery of
this bodies into the Earth crossing region. We selected 18 candidate V-type
asteroids in the Mars crossing region using observations contained in the Sloan
Digital Sky Survey Moving Objects Catalog. Then, we observed 4 of these
candidates to take their visible spectra using the Southern Astrophysical
Research Telescope (SOAR). We also performed the numerical simulation of the
orbital evolution of the observed asteroids. We confirmed that 3 of the
observed asteroids belong to the V class, and one of these may follow a path
that drives it to an Earth collision in some tens of million years
Anti-Phospholipase A2 Receptor Antibodies in Membranous Nephropathy : from Bench to the Patient
Membranous Nephropathy (MN) is the leading cause of nephrotic syndrome in adults. Primary or idiopathic Membranous Nephropathy (iMN) has been considered as an organ-specific autoimmune disease with an unknown aetiology. By contrast, secondary membranous nephropathy has been described as the expression of a systemic autoimmune response to malignancy or bacterial/viral infections. In the majority of iMN cases, glomerular lesions are determined by autoantibodies against a podocyte membrane protein, the M-type of phospholipase A2 receptor 1 (PLA2R1). Several studies have suggested that the detection of anti-PLA2R1 in patients sera with nephrotic syndrome may be pathognomonic of iMN, thus obviating the need for a diagnostic renal biopsy and an extensive workup for underlying causes. Many authors inferred that the measurement of anti-PLA2R1 may change the diagnostic algorithm in patients with nephrotic syndrome and guide treatment decisions in patients with iMN. Measurement of anti-PLA2R1 antibodies is now possible through an easy to use, commercially available assay. The aim of this review is to describe the clinical relevance of anti-PLA2R1 assessment in patients with MN, and to extensively discuss the biotechnological methods available to measure them
Intra-guild spatial niche overlap among three small falcon species in an area of recent sympatry
Climate warming and land-use change are reshuffling the distribution of wild organisms on a global scale. Some species may expand their ranges and colonize new regions, which may greatly affect ecological interactions among pre-existing species and colonizers. In the last decades, such processes have originated a unique condition of sympatry among three Eurasian small Falco species (common kestrel F. tinnunculus, lesser kestrel F. naumanni, red-footed falcon F. vespertinus) in the intensively cultivated farmland habitats of the Po Plain (Northern Italy). This provides an excellent opportunity to investigate patterns of spatial niche overlap during the initial phases of the establishment of sympatry. To investigate spatial niche overlap of the three falcon species, we relied on Environmental Niche Models (ENMs) based on widespread breeding occurrence data obtained through field surveys and citizen science programs (during the 2018-2020 period). ENMs were based on bioclimatic and land-use variables in an ensemble modelling framework. We estimated species-specific relative contributions of each climatic and land-use variable and its response curves effect. Eventually, we generated spatial correlation maps of the potential species' distributions to derive spatially-explicit predictions of potential co-occurrence areas among the three species. Overall, eco-climatic determinants of the distribution of lesser kestrel and red-footed falcon were similar, resulting in a strong association with intensive arable lands and dry continental climate. Consistently, we found a high spatial correlation between the suitability maps of the two species, with highly suitable areas located in the Central-Eastern area of the Po Plain, corresponding to the core range of both species. Conversely, the common kestrel emerged as a habitat generalist and was widely distributed throughout the Po Plain. Our findings suggest that the recent sympatry between lesser kestrels and red-footed falcons in the Po Plain may promote ecological interactions and intra-guild competition
Experimental nest cooling reveals dramatic effects of heatwaves on reproduction in a Mediterranean bird of prey
Future climatic scenarios forecast increases in average temperatures as well as in the frequency, duration, and intensity of extreme events, such as heatwaves. Whereas behavioral adjustments can buffer direct physiological and fitness costs of exposure to excessive temperature in wild animals, these may prove more difficult during specific life stages when vagility is reduced (e.g., early developmental stages). By means of a nest cooling experiment, we tested the effects of extreme temperatures on different stages of reproduction in a cavity-nesting Mediterranean bird of prey, the lesser kestrel (Falco naumanni), facing a recent increase in the frequency of heatwaves during its breeding season. Nest temperature in a group of nest boxes placed on roof terraces was reduced by shading them from direct sunlight in 2 consecutive years (2021 and 2022). We then compared hatching failure, mortality, and nestling morphology between shaded and non-shaded (control) nest boxes. Nest temperature in control nest boxes was on average 3.9 degrees C higher than in shaded ones during heatwaves, that is, spells of extreme air temperature (>37 degrees C for =2 consecutive days) which hit the study area during the nestling-rearing phase in both years. Hatching failure markedly increased with increasing nest temperature, rising above 50% when maximum nest temperatures exceeded 44 degrees C. Nestlings from control nest boxes showed higher mortality during heatwaves (55% vs. 10% in shaded nest boxes) and those that survived further showed impaired morphological growth (body mass and skeletal size). Hence, heatwaves occurring during the breeding period can have both strong lethal and sublethal impacts on different components of avian reproduction, from egg hatching to nestling growth. More broadly, these findings suggest that the projected future increases of summer temperatures and heatwave frequency in the Mediterranean basin and elsewhere in temperate areas may threaten the local persistence of even relatively warm-adapted species
Rationale and evidence for the incorporation of heparin to the diclofenac epolamine medicated plaster
The nonsteroidal anti-inflammatory drug (NSAID) diclofenac epolamine (DHEP) formulated as a topical patch has demonstrated efficacy and safety in the localized treatment of acute pain from minor strains, sprains, and contusions, and for epicondylitis and knee osteoarthritis. The glycosaminoglycan heparin enhances the activity of topical NSAIDs formulated as a medicated plaster, even in the absence of any significant release of heparin. Therefore, DHEP Plus, a new formulation of the DHEP medicated plaster containing a small amount of heparin sodium as excipient has been developed.
Methods: We reviewed the pivotal and supportive studies of the clinical development program of the new patch and evaluated the role of heparin as an enhancer in the treatment of localized pain/inflammation of musculoskeletal structures, associated with post-traumatic and/or rheumatic conditions.
Results: The data were consistent with the concept that heparin increased the clinical activity of the DHEP Plus medicated plaster versus the reference DHEP medicated plaster through improved bioavailability due to enhanced movement of diclofenac from the plaster. Both DHEP formulations have the same dissolution profile, indicating that heparin does not change the physical and chemical characteristics of the plaster. Permeation testing showed that heparin is not released from the DHEP Plus medicated plaster. Efficacy studies showed that the DHEP Plus medicated plaster was significantly more effective in reducing pain than the reference marketed DHEP medicated plaster.
Conclusions: The benefit/risk assessment of DHEP Plus 180 mg medicated plaster is favorable, with a safety profile equal to placebo and improved efficacy over the reference marketed DHEP medicated plaster
Ensemble Properties of Comets in the Sloan Digital Sky Survey
We present the ensemble properties of 31 comets (27 resolved and 4
unresolved) observed by the Sloan Digital Sky Survey (SDSS). This sample of
comets represents about 1 comet per 10 million SDSS photometric objects.
Five-band (u,g,r,i,z) photometry is used to determine the comets' colors,
sizes, surface brightness profiles, and rates of dust production in terms of
the Af{\rho} formalism. We find that the cumulative luminosity function for the
Jupiter Family Comets in our sample is well fit by a power law of the form N(<
H) \propto 10(0.49\pm0.05)H for H < 18, with evidence of a much shallower fit
N(< H) \propto 10(0.19\pm0.03)H for the faint (14.5 < H < 18) comets. The
resolved comets show an extremely narrow distribution of colors (0.57 \pm 0.05
in g - r for example), which are statistically indistinguishable from that of
the Jupiter Trojans. Further, there is no evidence of correlation between color
and physical, dynamical, or observational parameters for the observed comets.Comment: 19 pages, 8 tables, 11 figures, to appear in Icaru
SARS-COV-2 comorbidity network and outcome in hospitalized patients in Crema, Italy
We report onset, course, correlations with comorbidities, and diagnostic accuracy of nasopharyngeal swab in 539 individuals suspected to carry SARS-COV-2 admitted to the hospital of Crema, Italy. All individuals underwent clinical and laboratory exams, SARS-COV-2 reverse transcriptase-polymerase chain reaction on nasopharyngeal swab, and chest X-ray and/or computed tomography (CT). Data on onset, course, comorbidities, number of drugs including angiotensin converting enzyme (ACE) inhibitors and angiotensin-II-receptor antagonists (sartans), follow-up swab, pharmacological treatments, non-invasive respiratory support, ICU admission, and deaths were recorded. Among 411 SARS-COV-2 patients (67.7% males) median age was 70.8 years (range 5-99). Chest CT was performed in 317 (77.2%) and showed interstitial pneumonia in 304 (96%). Fatality rate was 17.5% (74% males), with 6.6% in 60-69 years old, 21.1% in 70-79 years old, 38.8% in 80-89 years old, and 83.3% above 90 years. No death occurred below 60 years. Non-invasive respiratory support rate was 27.2% and ICU admission 6.8%. Charlson comorbidity index and high Creactive protein at admission were significantly associated with death. Use of ACE inhibitors or sartans was not associated with outcomes. Among 128 swab negative patients at admission (63.3% males) median age was 67.7 years (range 1-98). Chest CT was performed in 87 (68%) and showed interstitial pneumonia in 76 (87.3%). Follow-up swab turned positive in 13 of 32 patients. Using chest CT at admission as gold standard on the entire study population of 539 patients, nasopharyngeal swab had 80% accuracy. Comorbidity network analysis revealed a more homogenous distribution 60-40 aged SARS-COV-2 patients across diseases and a crucial different interplay of diseases in the networks of deceased and survived patients. SARS-CoV-2 caused high mortality among patients older than 60 years and correlated with pre-existing multiorgan impairment. Copyright
- …