402 research outputs found
A new method for deriving aerosol solar radiative forcing and its first application within MILAGRO/INTEX-B
We introduce a method for deriving aerosol spectral radiative forcing along with single scattering albedo, asymmetry parameter, and surface albedo from airborne vertical profile measurements of shortwave spectral irradiance and spectral aerosol optical thickness. The new method complements the traditional, direct measurement of aerosol radiative forcing efficiency from horizontal flight legs below gradients of aerosol optical thickness, and is particularly useful over heterogeneous land surfaces and for homogeneous aerosol layers where the horizontal gradient method is impractical. Using data collected by the Solar Spectral Flux Radiometer (SSFR) and the Ames Airborne Tracking Sunphotometer (AATS-14) during the MILAGRO (Megacity Initiative: Local and Global Research Observations) experiment, we validate an over-ocean spectral aerosol forcing efficiency from the new method by comparing with the traditional method. Retrieved over-land aerosol optical properties are compared with in-situ measurements and AERONET retrievals. The spectral forcing efficiencies over ocean and land are remarkably similar and agree with results from other field experiments
Dynamics of an Inelastic Gravitational Billiard with Rotation
The seminal physical model for investigating formulations of nonlinear
dynamics is the billiard. Gravitational billiards provide an experimentally
accessible arena for their investigation. We present a mathematical model that
captures the essential dynamics required for describing the motion of a
realistic billiard for arbitrary boundaries, where we include rotational
effects and additional forms of energy dissipation. Simulations of the model
are applied to parabolic, wedge and hyperbolic billiards that are driven
sinusoidally. The simulations demonstrate that the parabola has stable,
periodic motion, while the wedge and hyperbola (at high driving frequencies)
appear chaotic. The hyperbola, at low driving frequencies, behaves similarly to
the parabola; i.e., has regular motion. Direct comparisons are made between the
model's predictions and previously published experimental data. The value of
the coefficient of restitution employed in the model resulted in good agreement
with the experimental data for all boundary shapes investigated. It is shown
that the data can be successfully modeled with a simple set of parameters
without an assumption of exotic energy dependence.Comment: 11 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1103.443
Final performances of the X-ray Mirrors of the JET-X telescope
The Joint European Telesscope (JET-X) is one of the core scientific
instruments of the SPECTRUM-X-Gamma mission. JET-X was designed to study X-ray
emissions in the band 0.3-10 KeV. Its angular resolution is better than 20
arcsec; the values of the effective areas are 161 cm2 at 1.5 KeV and 69 cm2 at
8 Kev (for one telescope). The value of the HEW circle in function of the
off-axis angle is presented; it is found to be below 20 arcsec at 1.5 Kev and
around 23 arcsec at 8 KeV up to an off-axis angle of 12 arcmin.Comment: 2 pages, 1 ps figure. To be published in the Proceedings of the IAU
Symposium 188 THE HOT UNIVERSE, held in Kyoto (August 26-30, 1997) in
occasion of the XXIII IAU General Assembl
Treatment challenges in and outside a specialist network setting: Pancreatic neuroendocrine tumours
Pancreatic Neuroendocrine Neoplasms comprise a group of rare tumours with special biology, an often indolent behaviour and particular diagnostic and therapeutic requirements. The specialized biochemical tests and radiological investigations, the complexity of surgical options and the variety of medical treatments that require individual tailoring, mandate a multidisciplinary approach that can be optimally achieved through an organized network. The present study describes currents concepts in the management of these tumours as well as an insight into the challenges of delivering the pathway in and outside a Network
Testicular germ-cell tumours and penile squamous cell carcinoma: Appropriate management makes the difference
Germ-cell tumours (GCT) of the testis and penile squamous cell carcinoma (PeSCC) are a rare and a very rare uro-genital cancers, respectively. Both tumours are well defined entities in terms of management, where specific recommendations - in the form of continuously up-to-dated guide lines-are provided. Impact of these tumour is relevant. Testicular GCT affects young, healthy men at the beginning of their adult life. PeSCC affects older men, but a proportion of these patients are young and the personal consequences of the disease may be devastating. Deviation from recommended management may be a reason of a significant prognostic worsening, as proper treatment favourably impacts on these tumours, dramatically on GCT and significantly on PeSCC. RARECAREnet data may permit to analyse how survivals may vary according to geographical areas, histology and age, leading to assume that non-homogeneous health-care resources may impact the cure and definitive outcomes. In support of this hypothesis, some epidemiologic datasets and clinical findings would indicate that survival may improve when appropriate treatments are delivered, linked to a different accessibility to the best health institutions, as a consequence of geographical, cultural and economic barriers. Finally, strong clues based on epidemiological and clinical data support the hypothesis that treatment delivered at reference centres or under the aegis of a qualified multi-institutional network is associated with a better prognosis of patients with these malignancies. The ERN EURACAN represents the best current European effort to answer this clinical need
Treatment challenges in and outside a network setting: Head and neck cancers
Head and neck cancer (HNC) is a rare disease that can affect different sites and is characterized by variable incidence and 5-year survival rates across Europe. Multiple factors need to be considered when choosing the most appropriate treatment for HNC patients, such as age, comorbidities, social issues, and especially whether to prefer surgery or radiation-based protocols. Given the complexity of this scenario, the creation of a highly specialized multidisciplinary team is recommended to guarantee the best oncological outcome and prevent or adequately treat any adverse effect. Data from literature suggest that the multidisciplinary team-based approach is beneficial for HNC patients and lead to improved survival rates. This result is likely due to improved diagnostic and staging accuracy, a more efficacious therapeutic approach and enhanced communication across disciplines. Despite the benefit of MTD, it must be noted that this approach requires considerable time, effort and financial resources and is usually more frequent in highly organized and high-volume centers. Literature data on clinical research suggest that patients treated in high-accrual centers report better treatment outcomes compared to patients treated in low-volume centers, where a lower radiotherapy-compliance and worst overall survival have been reported. There is general agreement that treatment of rare cancers such as HNC should be concentrated in high volume, specialized and multidisciplinary centers. In order to achieve this goal, the creation of international collaboration network is fundamental. The European Reference Networks for example aim to create an international virtual advisory board, whose objectives are the exchange of expertise, training, clinical collaboration and the reduction of disparities and enhancement of rationalize migration across Europe. The purpose of our work is to review all aspects and challenges in and outside this network setting planned for the management of HNC patients
Adaptation to flood risk: Results of international paired flood event studies
As flood impacts are increasing in large parts of the world, understanding the primary drivers of changes in risk is essential for effective adaptation. To gain more knowledge on the basis of empirical case studies, we analyze eight paired floods, that is, consecutive flood events that occurred in the same region, with the second flood causing significantly lower damage. These success stories of risk reduction were selected across different socioeconomic and hydro-climatic contexts. The potential of societies to adapt is uncovered by describing triggered societal changes, as well as formal measures and spontaneous processes that reduced flood risk. This novel approach has the potential to build the basis for an international data collection and analysis effort to better understand and attribute changes in risk due to hydrological extremes in the framework of the IAHSs Panta Rhei initiative. Across all case studies, we find that lower damage caused by the second event was mainly due to significant reductions in vulnerability, for example, via raised risk awareness, preparedness, and improvements of organizational emergency management. Thus, vulnerability reduction plays an essential role for successful adaptation. Our work shows that there is a high potential to adapt, but there remains the challenge to stimulate measures that reduce vulnerability and risk in periods in which extreme events do not occur
Multiparametric magnetic resonance imaging and frozen-section analysis efficiently predict upgrading, upstaging, and extraprostatic extension in patients undergoing nerve-sparing robotic-assisted radical prostatectomy
To evaluate the role of multiparametric magnetic resonance imaging (mpMRI) in predicting upgrading, upstaging, and extraprostatic extension in patients with low-risk prostate cancer (PCa). MpMRI may reduce positive surgical margins (PSM) and improve nerve-sparing during robotic-assisted radical prostatectomy (RARP) for localized prostate cancer PCa.This was a retrospective, monocentric, observational study. We retrieved the records of patients undergoing RARP from January 2012 to December 2013 at our Institution. Inclusion criteria were: PSA <10\u200ang/mL; clinical stage <T3a; biopsy Gleason score <7; prostate mpMRI performed preoperatively at our Institution; intraoperative FSA of the posterolateral aspects of the specimen.All the identified lesions were scored according to the Prostate Imaging Reporting and Data System (PIRADS). We considered the lesion with the highest PIRADS score as index lesion. All the included patients underwent nerve-sparing RARP. During surgery, the specimen was sent for FSA of the posterolateral aspects. The surgeon, according to the localization scheme provided by the mpMRI, inked the region of the posterolateral aspect of the prostate that had to be submitted to FSA.We evaluated association between clinical features and PSM, upgrading, upstaging, and presence of unfavorable disease.Two hundred fifty-four patients who underwent nerve-sparing RARP were included. PSM rate was 29.13% and 15.75% at FSA and final pathology respectively. Interestingly, the use of FSA reduced PSM rate in pT3 disease (25.81%). Higher PIRADS scores demonstrated to be related to high probability of upgrading and upstaging. This significativity remains even when considering PIRADS 2-3 versus 4 versus 5 and PIRADS 2-3 versus 4-5. Also PSM at FSA were associated with higher probability of upgrading and upstaging.PIRADS score and FSA resulted to be strictly related to grading and staging, thus being able to predict upgrading and/or upstaging at final pathology
MAK-4 and -5 supplemented diet inhibits liver carcinogenesis in mice
<p>Abstract</p> <p>Background</p> <p>Maharishi Amrit Kalash (MAK) is an herbal formulation composed of two herbal mixtures, MAK-4 and MAK-5. These preparations are part of a natural health care system from India, known as Maharishi Ayur-Veda. MAK-4 and MAK-5 are each composed of different herbs and are said to have maximum benefit when used in combination. This investigation evaluated the cancer inhibiting effects of MAK-4 and MAK-5, <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p><it>In vitro </it>assays: Aqueous extracts of MAK-4 and MAK-5 were tested for effects on <it>ras </it>induced cell transformation in the Rat 6 cell line assessed by focus formation assay. <it>In vivo </it>assays: Urethane-treated mice were put on a standard pellet diet or a diet supplemented with MAK-4, MAK-5 or both. At 36 weeks, livers were examined for tumors, sera for oxygen radical absorbance capacity (ORAC), and liver homogenates for enzyme activities of glutathione peroxidase (GPX), glutathione-S-transferase (GST), and NAD(P)H: quinone reductase (QR). Liver fragments of MAK-fed mice were analyzed for connexin (cx) protein expression.</p> <p>Results</p> <p>MAK-5 and a combination of MAK-5 plus MAK-4, inhibited <it>ras</it>-induced cell transformation. In MAK-4, MAK-5 and MAK4+5-treated mice we observed a 35%, 27% and 46% reduction in the development of urethane-induced liver nodules respectively. MAK-4 and MAK4+5-treated mice had a significantly higher ORAC value (<it>P </it>< 0.05) compared to controls (200.2 ± 33.7 and 191.6 ± 32.2 <it>vs. </it>152.2 ± 15.7 ORAC units, respectively). The urethane-treated MAK-4, MAK-5 and MAK4+5-fed mice had significantly higher activities of liver cytosolic enzymes compared to the urethane-treated controls and to untreated mice: GPX(0.23 ± 0.08, 0.21 ± 0.05, 0.25 ± 0.04, 0.20 ± 0.05, 0.21 ± 0.03 U/mg protein, respectively), GST (2.0 ± 0.4, 2.0 ± 0.6, 2.1 ± 0.3, 1.7 ± 0.2, 1.7 ± 0.2 U/mg protein, respectively) and QR (0.13 ± 0.02, 0.12 ± 0.06, 0.15 ± 0.03, 0.1 ± 0.04, 0.11 ± 0.03 U/mg protein, respectively). Livers of MAK-treated mice showed a time-dependent increased expression of cx32.</p> <p>Conclusion</p> <p>Our results show that a MAK-supplemented diet inhibits liver carcinogenesis in urethane-treated mice. The prevention of excessive oxidative damage and the up-regulation of connexin expression are two of the possible effects of these products.</p
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Populism and nationalism in a comparative perspective: a scholarly exchange
The purpose of the Exchange feature is to publish discussions that engage, advance
and initiate new debates in the study of nations and nationalism. This Exchange
article is on the subject of ‘Populism and Nationalism’. Each contributor addresses the
following four questions on the subject: (1) What is populism and what role does it
play within the context of democratic politics? (2) Does populism cut across left-right
lines? (3) What is the relationship between nationalism and populism? (4) Are
contemporary populist movements across Europe and the West comparable? Our aim
is to generate a thought- provoking conversation with regards to the rise of populism
in Europe and the West
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