131 research outputs found
A comparison between families obtained from different proper elements
Using the hierarchical method of family identification developed by Zappala et al., the results coming from the data set of proper elements computed by Williams (about 2100 numbered + about 1200 PLS 2 asteroids) and by Milani and Knezevic (5.7 version, about 4200 asteroids) are compared. Apart from some expected discrepancies due to the different data sets and/or low accuracy of proper elements computed in peculiar dynamical zones, a good agreement was found in several cases. It follows that these high reliability families represent a sample which can be considered independent on the methods used for their proper elements computation. Therefore, they should be considered as the best candidates for detailed physical studies
From asteroid clusters to families: A proposal for a new nomenclature
Some confusion on the number, reliability, and characteristics of asteroid families is the result of using the single word 'family' for naming asteroid groupings identified in very different ways. Here we propose a new terminology which in our opinion would alleviate this problem
Gastric adenocarcinoma cutaneous metastasis arising at a previous surgical drain site: a case report
<p>Abstract</p> <p>Introduction</p> <p>Skin metastasis from internal carcinoma rarely occurs. It has an incidence of 0.7 to 9% and it may be the first sign of an unknown malignancy. However, it can also occur during follow-up.</p> <p>Case presentation</p> <p>A 90-year-old female patient was admitted to our surgical division with a diagnosis of anemia from a bleeding gastric adenocarcinoma. She underwent a gastric resection and Billroth II retrocolic Hofmeister/Finsterer reconstruction. She developed an enteric fistula, which needed a permanent abdominal drain until the 60<sup>th </sup>postoperative day. After 12 months she was readmitted to our division with subacute small bowel obstruction and an erythematous swelling on the right side of the abdomen. Biopsies characterized it as a cutaneous metastasis from the gastric adenocarcinoma. No surgical therapy was performed given her poor clinical condition.</p> <p>Conclusion</p> <p>Skin metastasis from carcinomas of the upper gastrointestinal tract is very rare. Persisting erythematous nodules must be biopsied in order to diagnose cutaneous metastases and to recognize them early and start prompt therapy with anti-tumour agents before the occurrence of massive visceral metastases.</p
A Comparison of Embedded Deep Learning Methods for Person Detection
Recent advancements in parallel computing, GPU technology and deep learning
provide a new platform for complex image processing tasks such as person
detection to flourish. Person detection is fundamental preliminary operation
for several high level computer vision tasks. One industry that can
significantly benefit from person detection is retail. In recent years, various
studies attempt to find an optimal solution for person detection using neural
networks and deep learning. This study conducts a comparison among the state of
the art deep learning base object detector with the focus on person detection
performance in indoor environments. Performance of various implementations of
YOLO, SSD, RCNN, R-FCN and SqueezeDet have been assessed using our in-house
proprietary dataset which consists of over 10 thousands indoor images captured
form shopping malls, retails and stores. Experimental results indicate that,
Tiny YOLO-416 and SSD (VGG-300) are the fastest and Faster-RCNN (Inception
ResNet-v2) and R-FCN (ResNet-101) are the most accurate detectors investigated
in this study. Further analysis shows that YOLO v3-416 delivers relatively
accurate result in a reasonable amount of time, which makes it an ideal model
for person detection in embedded platforms
Sexuality education in Italy 2016-2020: a national survey investigating coverage, content and evaluation of school-based educational activities
Comprehensive sexuality education is an important means of promoting sexual well-being amongst young people and is key to preventing sexually transmitted infections (STIs). However, sexuality education is not currently included in the formal curriculum in Italian schools. The aim of this study was to develop an inventory of schoolbased sexuality education (SBSE) activities carried out by external providers and implemented in Italy from 2016 to 2020. A desk review and survey were carried out. In the desk review online documents on STI prevention were analysed. The survey investigated the providers, objectives, content and methods used to implement SBSE activities in secondary schools. Findings revealed a highly heterogeneous situation in terms of geographical coverage, service providers, objectives and evaluation. Some SBSE activities were classified as adopting a comprehensive approach to sexuality education, while the majority focused on STI prevention, and many were single-session activities. Although most activities were said to have been evaluated no results were available. The data showed that SBSE is not systematically and equally delivered across Italy. Action is needed to provide young people with evidence-based, age-appropriate and accurate education about sexual and reproductive health and wellbeing
Formes d'ast\'ero\"ides et formation de satellites : r\^ole de la r\'eaccumulation gravitationnelle
Asteroid shapes and satellites: role of gravitational reaccumulation.
Following current evidences, it is widely accepted that many asteroids would be
"gravitational aggregates", i.e. bodies lacking internal cohesion. They could
mainly be originated during the catastrophic disruption of some parent bodies,
through the gravitational reaccumulation of the resulting fragments. The same
events produced the dynamical families that we observe. In this work we address
the problem of the origin of shapes of gravitational aggregates, that could
contain signatures of their origin. We use a N-body code to simulate the
collapse of a cloud of fragments, with a variety of initial velocity
distributions and total angular momentum. The fragments are treated as
inhelastic spheres, that rapidly accumulate to form rotating aggregates. The
resulting shapes and rotational properties are compared with theoretical
predictions. The results show that only a precise category of shapes (flattened
spheroids) are created via this mechanism. This may provide interesting
constraints on the evolution of asteroid shapes, in particular for those with
one or more satellites
Mortality of emergency abdominal surgery in high-, middle- and low-income countries
Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI).
Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression.
Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1â‹…6 per cent at 24 h (high 1â‹…1 per cent, middle 1â‹…9 per cent, low 3â‹…4 per cent; P < 0â‹…001), increasing to 5â‹…4 per cent by 30 days (high 4â‹…5 per cent, middle 6â‹…0 per cent, low 8â‹…6 per cent; P < 0â‹…001). Of the 578 patients who died, 404 (69â‹…9 per cent) did so between 24 h and 30 days following surgery (high 74â‹…2 per cent, middle 68â‹…8 per cent, low 60â‹…5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2â‹…78, 95 per cent c.i. 1â‹…84 to 4â‹…20) and low-income (OR 2â‹…97, 1â‹…84 to 4â‹…81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days.
Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)
Conservation laws and mass distribution in the planet formation process
Within the framework of the nebular theory of the origin of the solar system, conservation laws are applied to the condensation of a ring-shaped cloud of orbiting particles. The final configuration is assumed to be a point-like planet in a circular orbit around the sun. On this ground, it is possible to relate the masses of the planets with the interplanetary distances. This relation is confirmed satisfactorily by the observed masses and orbital radii of several planets and satellites of the solar system
The critical energy density and the inelasticity coefficient for asteroidal catastrophic collisions
Experimental results on high-velocity impacts reported in the literature are analyzed in detail. The purpose of the analysis is twofold: (1) to assess the possibility of applying to asteroidal collisions (without a size-dependent scaling) the critical energy densities associated with various degrees of fragmentation; and (2) to determine which fraction of the projectile's energy is converted into the kinetic energy of fragments after a catastrophic breakup. It is shown that the critical energy density is independent of size only for supercatastrophic events when no massive core survives, whereas it slowly decreases for larger targets when the fragmentation is only partial. The energy gap between cratering and complete destruction is therefore probably wider for the asteroids than for the small experimental targets. It is also shown that the inelasticity coefficient (i.e., the resulting fraction of kinetic energy) depends both on the impact velocity and on the projectile-to-target mass ratio; this coefficient probably ranges from 0.01 to 0.1 for asteroidal catastrophic collisions
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