Continental faunal exchange and the asymmetrical radiation of carnivores.

Lineages arriving on islands may undergo explosive evolutionary radiations owing to the wealth of ecological opportunities. Although studies on insular taxa have improved our understanding of macroevolutionary phenomena, we know little about the macroevolutionary dynamics of continental exchanges. Here we study the evolution of eight Carnivora families that have migrated across the Northern Hemisphere to investigate if continental invasions also result in explosive diversification dynamics. We used a Bayesian approach to estimate speciation and extinction rates from a substantial dataset of fossil occurrences while accounting for the incompleteness of the fossil record. Our analyses revealed a strongly asymmetrical pattern in which North American lineages invading Eurasia underwent explosive radiations, whereas lineages invading North America maintained uniform diversification dynamics. These invasions into Eurasia were characterized by high rates of speciation and extinction. The radiation of the arriving lineages in Eurasia coincide with the decline of established lineages or phases of climate change, suggesting differences in the ecological settings between the continents may be responsible for the disparity in diversification dynamics. These results reveal long-term outcomes of biological invasions and show that the importance of explosive radiations in shaping diversity extends beyond insular systems and have significant impact at continental scales.

Study of Johnsons Glacier (Livingston Island, Antarctica) by means of shallow ice cores and their tephra and by analysis of 137Cs content

With the aim of monitoring the dynamics of the Livingston Island ice cap, the Departament de Geodinàmica i Geofísica of the Universitat de Barcelona began ye a r ly surveys in the austral summer of 1994-95 on Johnsons Glacier. During this field campaign 10 shallow ice cores were sampled with a manual ve rtical ice-core drilling machine. The objectives were: i) to detect the tephra layer accumulated on the glacier surface, attributed to the 1970 Deception Island pyroclastic eruption, today interstratified; ii) to verify wheter this layer might serve as a reference level; iii) to measure the 1 3 7Cs radio-isotope concentration accumulated in the 1965 snow stratum; iv) to use the isochrone layer as a mean of verifying the age of the 1970 tephra layer; and, v) to calculate both the equilibrium line of the glacier and average mass balance over the last 28 years (1965-1993). The stratigr a p hy of the cores, their cumulative density curves and the isothermal ice temperatures recorded confi rm that Johnsons Glacier is a temperate glacier. Wi n d, solar radiation heating and liquid water are the main agents controlling the ve rtical and horizontal redistribution of the volcanic and cryoclastic particles that are sedimented and remain interstratified within the g l a c i e r. It is because of this redistribution that the 1970 tephra layer does not always serve as a ve ry good reference level. The position of the equilibrium line altitude (ELA) in 1993, obtained by the 1 3 7Cs spectrometric analysis, varies from about 200 m a.s.l. to 250 m a.s.l. This indicates a rising trend in the equilibrium line altitude from the beginning of the 1970s to the present day. The va rying slope orientation of Johnsons Glacier relative to the prevailing NE wind gives rise to large local differences in snow accumulation, which locally modifies the equilibrium line altitude. In the cores studied, 1 3 7Cs appears to be associated with the 1970 tephra laye r. This indicates an intense ablation episode throughout the sampled area (at least up to 330 m a.s.l), which probably occurred synchronically to the 1970 tephra deposition or later. A rough estimate of the specific mass balance reveals a considerable accumulation gradient related to the increase with altitude.

Stereotactic body radiation therapy with helical tomotherapy for medical inoperable early-stage primary and second-primary non-small cell lung neoplasm : one-year outcome and toxicity analysis

Le cancer du poumon est la première cause de mortalité associée au cancer dans le monde. Le traitement curatif des tumeurs pulmonaires non-à-petites-cellules (NSCLC) diagnostiquées à un stade précoce se base sur une approche chirurgicale. Cependant, étant donné les comorbidités liées à la consommation de tabac, dont la bronchopneumopathie chronique occupe la première place, l'éligibilité chirurgicale pour ce type de cancer se trouve fréquemment limitée. Dans ce contexte, l'emploi de la radiothérapie stéréotaxique (SBRT) est une alternative valable chez les patients atteints d'un NSCLC primaire de stade précoce, et qui sont considérés inopérables à cause de leurs comorbidités. Depuis peu seulemement, le spectre de la SBRT a été élargi aux patients atteints d'un deuxième NSCLC primaire (SPLC), faisant suite à un premier NSCLC, traité avec un but curatif. Ils concernent donc des patients ayant déjà subits une intervention chirurgicale au préalable et qui présentent une réserve fonctionnelle pulmonaire extrêmement réduite. Le succès croissant de la SBRT résulte soit d'une efficacité thérapeutique comparables à la chirurgie, soit de sa toxicité qui semble limitée. À notre connaissance, seulement une étude a reporté des issues cliniques de patients affectés par des NSCLC primaires traités par SBRT. Cette dernière a utilisé la tomothérapie comme système d'irradiation (T-SBRT), sur un faible échantillon de patients (n = 27). Concernant l'irradiation des patients présentant des SPLC, la littérature disponible est pauvre et aucune publication a décrit l'utilisation de la T-SBRT. Ces éléments innovants ont donc motivé la rédaction d'un travail de thèse concernant les premières données cliniques de l'expérience faite au CHUV. Du point de vue des effets secondaires, si la pneumonie actinique précoce et tardive survenant au niveau du champ d'irradiation est désormais une complication iatrogène bien connue de la SBRT, une seule étude s'est intéressée à ce sujet dans le cadre de la T-SBRT. De plus, une entité bénigne et transitoire de pneumonie ( ?) a été reconnue depuis peu : la pneumonie organisée radio-induite (OP). Celle-ci semble se chevaucher comme un autre effet iatrogène à l'extérieur du champ d'irradiation. Originellement, cette dernière avait été rapportée dans les suites de la radiothérapie pour les cancer du sein. Elle a été décrite comme étant initialement limitée au champ d'irradiation et successivement pouvant s'étendre dynamiquement en dehors de celui-ci. Nous avons donc supposé que des infiltrats de OP peuvent être présents chez des patients asymptomatiques, et que ce dynamisme pourrait être identifié déjà au sein du champ d'irradiation. Notre étude a démontré que le traitement par T-SBRT garde des issues cliniques très encourageantes, aussi bien pour les tumeurs primaires que pour les SPLC. Entre autre, ce traitement semble avoir une toxicité limitée, et l'existence vraisemblable de la OP, déjà au sein du champ d'irradiation, peut aider les radiologues à différencier les infiltrats radio-induits d'une une récidive tumorale.

Qualitative, quantitative and temporal study of cutting agents for cocaine and heroin over 9 years

Forensic laboratories mainly focus on the qualification and the quantitation of the illicit drug under analysis as both aspects are used for judiciary purposes. Therefore, information related to cutting agents (adulterants and diluents) detected in illicit drugs is limited in the forensic literature. This article discusses the type and frequency of adulterants and diluents detected in more than 6000 cocaine specimens and 3000 heroin specimens, confiscated in western Switzerland from 2006 to 2014. The results show a homogeneous and quite unchanging adulteration for heroin, while for cocaine it could be characterised as heterogeneous and relatively dynamic. Furthermore, the results indicate that dilution affects more cocaine than heroin. Therefore, the results provided by this study tend to reveal differences between the respective structures of production or distribution of cocaine and heroin. This research seeks to promote the systematic analysis of cutting agents by forensic laboratories. Collecting and processing data related to the presence of cutting agents in illicit drug specimens produces relevant information to understand and to compare the structure of illicit drug markets.

Optimization of Radiation Dose and Image Quality in Musculoskeletal CT: Emphasis on Iterative Reconstruction Techniques (Part 1).

Computed tomography (CT) is a modality of choice for the study of the musculoskeletal system for various indications including the study of bone, calcifications, internal derangements of joints (with CT arthrography), as well as periprosthetic complications. However, CT remains intrinsically limited by the fact that it exposes patients to ionizing radiation. Scanning protocols need to be optimized to achieve diagnostic image quality at the lowest radiation dose possible. In this optimization process, the radiologist needs to be familiar with the parameters used to quantify radiation dose and image quality. CT imaging of the musculoskeletal system has certain specificities including the focus on high-contrast objects (i.e., in CT of bone or CT arthrography). These characteristics need to be taken into account when defining a strategy to optimize dose and when choosing the best combination of scanning parameters. In the first part of this review, we present the parameters used for the evaluation and quantification of radiation dose and image quality. In the second part, we discuss different strategies to optimize radiation dose and image quality at CT, with a focus on the musculoskeletal system and the use of novel iterative reconstruction techniques.

Uncertainty associated with Monte Carlo radiation transport in radionuclide metrology

In radionuclide metrology, Monte Carlo (MC) simulation is widely used to compute parameters associated with primary measurements or calibration factors. Although MC methods are used to estimate uncertainties, the uncertainty associated with radiation transport in MC calculations is usually difficult to estimate. Counting statistics is the most obvious component of MC uncertainty and has to be checked carefully, particularly when variance reduction is used. However, in most cases fluctuations associated with counting statistics can be reduced using sufficient computing power. Cross-section data have intrinsic uncertainties that induce correlations when apparently independent codes are compared. Their effect on the uncertainty of the estimated parameter is difficult to determine and varies widely from case to case. Finally, the most significant uncertainty component for radionuclide applications is usually that associated with the detector geometry. Recent 2D and 3D x-ray imaging tools may be utilized, but comparison with experimental data as well as adjustments of parameters are usually inevitable.

Epidemiology and injury patterns of patients consulting following assault by nightclub security agents in a university hospital emergency service and an associated specialised forensic consultation

Introduction: The Violence Medical Unit (VMU), a specialised forensic medical consultation, was created at the Lausanne university Hospital in 2006. All patients consulting at the ED for interpersonal violencerelated injury are referred to the VMU, which provides forensic documentation of the injury and referral to the relevant community based victim-support organisations within 48 hours of the ED visit. This frees the ED medical staff from forensic injury documentation and legal/social referral, tasks for which they lack both time and training. Among community violence, assaults by nightclub security agents against patrons have increased from 6% to 10% between 2007 and 2009. We set out to characterise the demographics, assault mechanisms, subsequent injuries, prior alcohol intake and ED & VMU costs incurred by this group of patients. Methods: We retrospectively included all patients consulting at the VMU due to assault by nightclub security agents from January 2007 to December 2009. Data was obtained from ED & VMU medical, nursing and administrative records. Results: Our sample included 70 patients, of which 64 were referred by the CHUV ED. The victims were typically young (median age 29) males (93%). 77% of assaults occurred on the weekend between 12 PM and 4 AM, and 73% of the victims were under the influence of alcohol. 83% of the patients were punched, kicked and/or head-butted; 9% had been struck with a blunt instrument. 80% of the injuries were in the head and neck area and 19% of the victims sustained fractures. 21% of the victims were prescribed medical leave. Total ED & VMU costs averaged 1048 SFr. Conclusion: Medical staff treating this population of assault victims must be aware of the assault mechanisms and injury patterns, in particular the high probability of fractures, in order to provide adequate diagnosis and care. Associated inebriation mandates liberal use of radiology, as delayed or missed diagnosis may have medical, medicolegal and legal implications. Emergency medical services play an important role in detecting and reporting of such incidents. Centralised management of the forensic documentation facilitates referral to victim support organisations and epidemiological data collection. Magnitudes and trends of the different types of violence can be determined, and this information can be then impact public safety management policies.

Optimization of Radiation Dose and Image Quality in Musculoskeletal CT: Emphasis on Iterative Reconstruction Techniques (Part 2).

Computed tomography (CT) is a modality of choice for the study of the musculoskeletal system for various indications including the study of bone, calcifications, internal derangements of joints (with CT arthrography), as well as periprosthetic complications. However, CT remains intrinsically limited by the fact that it exposes patients to ionizing radiation. Scanning protocols need to be optimized to achieve diagnostic image quality at the lowest radiation dose possible. In this optimization process, the radiologist needs to be familiar with the parameters used to quantify radiation dose and image quality. CT imaging of the musculoskeletal system has certain specificities including the focus on high-contrast objects (i.e., in CT of bone or CT arthrography). These characteristics need to be taken into account when defining a strategy to optimize dose and when choosing the best combination of scanning parameters. In the first part of this review, we present the parameters used for the evaluation and quantification of radiation dose and image quality. In the second part, we discuss different strategies to optimize radiation dose and image quality of CT, with a focus on the musculoskeletal system and the use of novel iterative reconstruction techniques.

Fast and sensitive supercritical fluid chromatography - tandem mass spectrometry multi-class screening method for the determination of doping agents in urine.

This study shows the possibility offered by modern ultra-high performance supercritical fluid chromatography combined with tandem mass spectrometry in doping control analysis. A high throughput screening method was developed for 100 substances belonging to the challenging classes of anabolic agents, hormones and metabolic modulators, synthetic cannabinoids and glucocorticoids, which should be detected at low concentrations in urine. To selectively extract these doping agents from urine, a supported liquid extraction procedure was implemented in a 48-well plate format. At the tested concentration levels ranging from 0.5 to 5 ng/mL, the recoveries were better than 70% for 48-68% of the compounds and higher than 50% for 83-87% of the tested substances. Due to the numerous interferences related to isomers of steroids and ions produced by the loss of water in the electrospray source, the choice of SFC separation conditions was very challenging. After careful optimization, a Diol stationary phase was employed. The total analysis time for the screening assay was only 8 min, and interferences as well as susceptibility to matrix effect (ME) were minimized. With the developed method, about 70% of the compounds had relative ME within the range ±20%, at a concentration of 1 and 5 ng/mL. Finally, limits of detection achieved with the above-described strategy including 5-fold preconcentration were below 0.1 ng/mL for the majority of the tested compounds. Therefore, LODs were systematically better than the minimum required performance levels established by the World anti-doping agency, except for very few metabolites.

Ambient radiation levels in positron emission tomography/computed tomography (PET/CT) imaging center

Objective: To evaluate the level of ambient radiation in a PET/CT center. Materials and Methods: Previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results: In none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion: In the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed.

Enhancement of viability of radiosensitive (PBMC) and resistant (MDA-MB-231) clones in low-dose-rate cobalt-60 radiation therapy

AbstractObjective:In the present study, the authors investigated the in vitrobehavior of radio-resistant breast adenocarcinoma (MDA-MB-231) cells line and radiosensitive peripheral blood mononuclear cells (PBMC), as a function of different radiation doses, dose rates and postirradiation time kinetics, with a view to the interest of clinical radiotherapy.Materials and Methods:The cells were irradiated with Co-60, at 2 and 10 Gy and two different exposure rates, 339.56 cGy.min–1 and the other corresponding to one fourth of the standard dose rates, present over a 10-year period of cobalt therapy. Post-irradiation sampling was performed at pre-established kinetics of 24, 48 and 72 hours. The optical density response in viability assay was evaluated and a morphological analysis was performed.Results:Radiosensitive PBMC showed decrease in viability at 2 Gy, and a more significant decrease at 10 Gy for both dose rates. MDAMB- 231 cells presented viability decrease only at higher dose and dose rate. The results showed MDA-MB-231 clone expansion at low dose rate after 48–72 hours post-radiation.Conclusion:Low dose rate shows a possible potential clinical impact involving decrease in management of radio-resistant and radiosensitive tumor cell lines in cobalt therapy for breast cancer.