4,852 research outputs found
A history of the Department of Legal Medicine at Medical College of Virginia
Legal medicine can be defined as the aoience of the application of medical knowledge to the purposes of the law. Therefore, its limits are on the one hand the requirements of the laws and on the other the whole range of medicine, that is to say, anatomy, physiology, pathology, pharmacology, medicine, surgery, obstetrics, gynecology, and all the sciences auxiliary thereto, that is, chemistry, physics, botany, et cetera; all lend their aid when necessity arises and in the same case to enable a court of law to arrive at a proper conclusion on a contested question affecting life or property.
With the realization of the importance of legal medicine to society, this paper is an attempt to synthesize some of the more important developmental aspects related to the establishment of one of the country\u27s first legal medicine departments
Diagnosing transient ionization in dynamic events
The present study aims to provide a diagnostic line ratio that will enable
the observer to determine whether a plasma is in a state of transient
ionization. We use the Atomic Data and Analysis Structure (ADAS) to calculate
line contribution functions for two lines, Si IV 1394 A and O IV 1401 A, formed
in the solar transition region. The generalized collisional-radiative theory is
used. It includes all radiative and electron collisional processes, except for
photon-induced processes. State-resolved direct ionization and recombination to
and from the next ionization stage are also taken into account. For dynamic
bursts with a decay time of a few seconds, the Si IV 1394 A line can be
enhanced by a factor of 2-4 in the first fraction of a second with the peak in
the line contribution function occurring initially at a higher electron
temperature due to transient ionization compared to ionization equilibrium
conditions. On the other hand, the O IV 1401 A does not show such any
enhancement. Thus the ratio of these two lines, which can be observed with the
Interface Region Imaging Spectrograph, can be used as a diagnostic of transient
ionization. We show that simultaneous high-cadence observations of two lines
formed in the solar transition region may be used as a direct diagnostic of
whether the observed plasma is in transient ionization. The ratio of these two
lines can change by a factor of four in a few seconds owing to transient
ionization alone.Comment: 3 pages, in press A&
First Archaeological Activities by the University of Naples L'Orientale in Dhofar, Sultanate of Oman
Seeking for the rational basis of the median model: the optimal combination of multi-model ensemble results
International audienceIn this paper we present an approach for the statistical analysis of multi-model ensemble results. The models considered here are operational long-range transport and dispersion models, also used for the real-time simulation of pollutant dispersion or the accidental release of radioactive nuclides. We first introduce the theoretical basis (with its roots sinking into the Bayes theorem) and then apply this approach to the analysis of model results obtained during the ETEX-1 exercise. We recover some interesting results, supporting the heuristic approach called "median model", originally introduced in Galmarini et al. (2004a, b). This approach also provides a way to systematically reduce (and quantify) model uncertainties, thus supporting the decision-making process and/or regulatory-purpose activities in a very effective manner
The supergiant fast X-ray transients XTE J1739-302 and IGR J08408-4503 in quiescence with XMM-Newton
Context. Supergiant fast X-ray transients are a subclass of high mass X-ray
binaries that host a neutron star accreting mass from the wind of its OB
supergiant companion. They are characterized by an extremely pronounced and
rapid variability in X-rays, which still lacks an unambiguous interpretation. A
number of deep pointed observations with XMM-Newton have been carried out to
study the quiescent emission of these sources and gain insight into the
mechanism that causes their X-ray variability. Aims. We continued this study by
using three XMM-Newton observations of the two supergiant fast X-ray transient
prototypes XTEJ1739-302 and IGR J08408-4503 in quiescence. Methods. An in-depth
timing and spectral analysis of these data have been carried out. Results. We
found that the quiescent emission of these sources is characterized by both
complex timing and spectral variability, with multiple small flares occurring
sporadically after periods of lower X-ray emission. Some evidence is found in
the XMM-Newton spectra of a soft component below ~2 keV, similar to that
observed in the two supergiant fast X-ray transients AXJ1845.0-0433 and
IGRJ16207-5129 and in many other high mass X-ray binaries. Conclusions.We
suggest some possible interpretations of the timing and spectral properties of
the quiescent emission of XTEJ1739- 302 and IGR J08408-4503 in the context of
the different theoretical models proposed to interpret the behavior of the
supergiant fast X-ray transients.Comment: 13 pages, 14 figures. Accepted for publication in A&A. V2: Corrected
few typo
Local-Scale Weather Forecasts over a Complex Terrain in an Early Warning Framework: Performance Analysis for the Val d'Agri (Southern Italy) Case Study
Forecasting applications based on hourly meteorological predictions for weather variables are nowadays used in energy market operations, planning of gas and power supply, and renewable energy, among others. Available meteorological and climatological data, as well as critical thresholds of rainfall, may also have a key role in the hazard classification, related to slope instabilities of pipelines and critical infrastructures along routes. The present study concerns the performance of a weather forecast model in the framework of an early warning system (EWS) application, which supports the integrity management of oil and gas pipelines. This EWS has been applied on to a specific area: the Val d'Agri basin in the Basilicata region of Southern Italy, which is extensively affected by several landslides and floods. The hourly precipitation forecasts are provided by a dedicated meteorological model, the KALM-HD, using two different horizontal resolutions, 1.25 and 5 km, to analyze possible influences of the mesh grid size as well. On this area, several weather stations were specifically deployed to obtain observed data in a region where hydrogeological hazards are relevant for asset management. A comparison among observations and the KALM-HD scaled forecasts on six of these weather stations is presented to assess the model performance. Besides, precipitation, temperature, and wind speed are evaluated as well. The forecasting analysis is performed considering two years of data both on an overall and seasonal basis. Results show that the KALM-HD performs well with the 1.25 km grid, particularly on temperature and wind speed variables. Since weather stations can be gathered in two main sets depending on their positions, differences arise in the forecast quality of these two groups, related to orography and thermal effects, whose detection is difficult in the typical narrow valleys characterizing the area of study. This issue prevalently influences temperatures and local winds, which, these latter, are generally underestimated, while precipitation is mainly driven by synoptic circulation and its interaction with mesoscale meteorological features
Calcareous nannofossil biostratigraphy of the M. del Casino section (northern Apennines, Italy) and paleoceanographic conditions at times of Late Miocene sapropel formation
A detailed quantitative calcareous nannofossil analysis has been performed on 138 samples from the astronomically
dated Monte del Casino section with the aim to identify and precisely date the most important calcareous nannofossil
events across the Tortonian=Messinian boundary in the Mediterranean, and to unravel paleoceanographic conditions at
times of sapropel formation during the Late Miocene. From the biostratigraphic perspective, the genus Amaurolithus
provides three successive first occurrences (FOs): A. primus, A.cf. amplificus and A. delicatus, dated at 7.446, 7.434
and 7.226 Ma, respectively. Other bioevents include the base and top of the 'small reticulofenestrids' Acme, dated at
7.644 and 6.697 Ma, and the FO, FCO and LO of R. rotaria, dated at 7.405, 7.226 and 6.771 Ma. These events
appear to be useful in improving biostratigraphic resolution in the Tortonian-Messinian boundary interval, at least for
the Mediterranean. Quantitative analysis revealed changes in the calcareous nannofossil assemblage associated with the
sapropels. The observed fluctuations suggest a single mechanism for sapropel formation in the Mediterranean during the
late Neogene. Sapropels are characterized by a decrease in the total number of coccoliths, interpreted mainly as a reduction
in calcareous nannofossil production due to increased siliceous plankton production during spring blooms; and an increase
in reworked specimens, interpreted to reflect enhanced continental input via river run-off. An increase in abundance of the
genus Rhabdosphaera can be explained by opportunistic behavior at the end of the spring bloom when nutrient levels start
to become impoverished. As far as sea surface water temperature indicators are concerned, warm water D. pentaradiatus
shows positive fluctuations in sapropels while cooler water D. intercalaris and C. pelagicus show negative fluctuations.
Ó 1999 Elsevier Science B.V. All rights reserved
A Machine Learning-Based Approach for Audio Signals Classification using Chebychev Moments and Mel-Coefficients
This paper proposes a machine learning-based architecture for audio signals classification based on a joint exploitation of the Chebychev moments and the Mel-Frequency Cepstrum Coefficients. The procedure starts with the computation of the Mel-spectrogram of the recorded audio signals; then, Chebychev moments are obtained projecting the Cadence Frequency Diagram derived from the Mel-spectrogram into the base of Chebychev moments. These moments are then concatenated with the Mel-Frequency Cepstrum Coefficients to form the final feature vector. By doing so, the architecture exploits the peculiarities of the discrete Chebychev moments such as their symmetry characteristics. The effectiveness of the procedure is assessed on two challenging datasets, UrbanSound8K and ESC-50
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