4,383 research outputs found
Four-dimensional drift-kinetic model for scrape-off layer plasmas
A four-dimensional plasma model able to describe the scrape-off layer region
of tokamak devices at arbitrary collisionality is derived in the drift-reduced
limit. The basis of the model is provided by a drift-kinetic equation that
retains the full non-linear Coulomb collision operator and describes
arbitrarily far from equilibrium distribution functions. By expanding the
dependence of distribution function over the perpendicular velocity in a
Laguerre polynomial basis and integrating over the perpendicular velocity, a
set of four-dimensional moment equations for the expansion coefficients of the
distribution function is obtained. The Coulomb collision operator, as well as
Poisson's equation, are evaluated explicitly in terms of perpendicular velocity
moments of the distribution function.Comment: 12 page
Direct radiative effects by anthropogenic particles at a polluted site: Rome (Italy)
The direct radiative effect (DRE) by all (anthropogenic plus natural) and anthropogenic aerosols is calculated at the solar (0.3–4 μm) and infrared (4–200 μm) spectral range to better address the annual cycle of the anthropogenic
aerosol impact at a site (Rome, Italy) significantly affected by pollution. Aerosol optical and microphysical properties from 2003 AERONET Sun/sky-photometer
measurements and solar surface albedos based on MODIS satellite sensor data constitute the necessary input to radiative transfer simulations. Clear- and all-sky
conditions are investigated by adopting ISCCP monthly products for high-, mid-, and low-cloud cover. It is shown that monthly mean values of aerosol optical depths by anthropogenic particles (AODa) are on average more than 50% of the corresponding all-aerosol-optical-depth (AOD) monthly means. In particular, the AODa/AOD ratio that varies within the (0.51–0.83) on autumn-winter (AW,
October-March), varies within the (0.50–0.71) range on spring-summer (SS, April-September) as a consequence of the larger contribution of natural particles on SS. The surface (sfc), all-sky DRE by anthropogenic particles that is negative all year round at solar wavelengths, represents on average 60% and 51% of the all-sky sfc-DRE by all aerosols
on AW and SS, respectively. The all-sky atmospheric forcing by anthropogenic particles (AFa) that is positive all year round, is little dependent on seasons: it varies within the (1.0–4.1)W/m2 and (2.0–4.2)W/m2 range on AW and SS, respectively. Conversely, the all-sky AF by all aerosols is characterized by a marked seasonality. As a consequence, the atmospheric forcing by anthropogenic particles that on average is 50% of the AF value on AW, decreases down to 36% of the AF value on SS. Infrared aerosol DREs that are positive all year round are significantly smaller than the corresponding absolute values of solar DREs. Clouds decrease on average ToA- and sfc-DRE absolute values by anthropogenic particles of 36% and 23%, respectively and are quite responsible of the seasonal dependence of aerosol forcing efficiencies by all and anthropogenic aerosols
Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality
The dynamics of electron-plasma waves are described at arbitrary
collisionality by considering the full Coulomb collision operator. The
description is based on a Hermite-Laguerre decomposition of the velocity
dependence of the electron distribution function. The damping rate, frequency,
and eigenmode spectrum of electron-plasma waves are found as functions of the
collision frequency and wavelength. A comparison is made between the
collisionless Landau damping limit, the Lenard-Bernstein and Dougherty
collision operators, and the electron-ion collision operator, finding large
deviations in the damping rates and eigenmode spectra. A purely damped entropy
mode, characteristic of a plasma where pitch-angle scattering effects are
dominant with respect to collisionless effects, is shown to emerge numerically,
and its dispersion relation is analytically derived. It is shown that such a
mode is absent when simplified collision operators are used, and that
like-particle collisions strongly influence the damping rate of the entropy
mode.Comment: 23 pages, 10 figures, accepted for publication on Journal of Plasma
Physic
Vertically resolved aerosol properties by multi-wavelength lidar measurements
An approach based on the graphical method of Gobbi and co-authors (2007) is
introduced to estimate the dependence on altitude of the aerosol fine mode
radius (<i>R</i><sub>f</sub>) and of the fine mode contribution (η) to the
aerosol optical thickness (AOT) from three-wavelength lidar measurements. The
graphical method of Gobbi and co-authors (2007) was applied to AERONET
(AErosol RObotic NETwork) spectral extinction observations and relies on the
combined analysis of the Ã…ngstrom exponent (<i>Ã¥</i>) and its
spectral curvature Δ<i>å</i>. Lidar measurements at 355, 532 and
1064 nm were used in this study to retrieve the vertical profiles of
<i>å</i> and Δ<i>å</i> and to estimate the dependence on
altitude of <i>R</i><sub>f</sub> and η(532 nm) from the
<i>å</i>–Δ<i>å</i> combined analysis. Lidar measurements
were performed at the Department of Mathematics and Physics of the
Universita' del Salento, in south-eastern Italy. Aerosol from continental
Europe, the Atlantic, northern Africa, and the Mediterranean Sea are often
advected over south-eastern Italy and as a consequence, mixed advection
patterns leading to aerosol properties varying with altitude are dominant.
The proposed approach was applied to ten measurement days to demonstrate its
feasibility in different aerosol load conditions. The selected days were
characterized by AOTs spanning the 0.26–0.67, 0.15–0.39, and 0.04–0.27
range at 355, 532, and 1064 nm, respectively. Mean lidar ratios varied
within the 31–83, 32–84, and 11–47 sr range at 355, 532, and 1064 nm,
respectively, for the high variability of the aerosol optical and
microphysical properties. <i>Ã¥</i> values calculated from lidar
extinction profiles at 355 and 1064 nm ranged between 0.1 and 2.5 with a
mean value ± 1 standard deviation equal to 1.3 ± 0.7.
Δ<i>å</i> varied within the −0.1–1 range with mean value
equal to 0.25 ± 0.43. <i>R</i><sub>f</sub> and η(532 nm) values
spanning the 0.05–0.3 μm and the 0.3–0.99 range,
respectively, were associated with the <i>Ã¥</i>–Δ<i>Ã¥</i> data points. <i>R</i><sub>f</sub> and η values showed no
dependence on the altitude. 60% of the data points were in the Δ<i>Ã¥</i>–<i>Ã¥</i> space delimited by the η and
<i>R</i><sub>f</sub> curves varying within 0.80–0.99 and 0.05–0.15 μm,
respectively, for the dominance of fine-mode particles in driving the AOT
over south-eastern Italy. Vertical profiles of the linear particle
depolarization ratio retrieved from lidar measurements, aerosol products from
AERONET sun photometer measurements collocated in space and time, analytical
back trajectories, satellite true colour images, and dust concentrations from
the BSC–DREAM (Barcelona Super Computing Center-Dust REgional Atmospheric
Model) model were used to demonstrate the robustness of the proposed method
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Strengthening multi-stakeholder cooperation in the international investment regime: The Brazilian model
The rule of law and dispute avoidance and settlement may not be enough to turn FDI into a means to the realization of the SDGs. Multi-stakeholder dialogue and cooperation should also be a central aspect of any institutional design. In this regard, the Brazilian model, at least in theory, scores better than most existing treaties and reform proposals
Potential human and plant pathogenic species in airborne pm10 samples and relationships with chemical components and meteorological parameters
A preliminary local database of potential (opportunistic) airborne human and plant pathogenic and non-pathogenic species detected in PM10 samples collected in winter and spring is provided, in addition to their seasonal dependence and relationships with meteorological parameters and PM10 chemical species. The PM10 samples, collected at a Central Mediterranean coastal site, were analyzed by the 16S rRNA gene metabarcoding approach, and Spearman correlation coefficients and redundancy discriminant analysis tri-plots were used to investigate the main relationships. The screening of 1187 detected species allowed for the detection of 76 and 27 potential (opportunistic) human and plant pathogens, respectively. The bacterial structure of both pathogenic and non-pathogenic species varied from winter to spring and, consequently, the inter-species relationships among potential human pathogens, plant pathogens, and non-pathogenic species varied from winter to spring. Few non-pathogenic species and even fewer potential human pathogens were significantly correlated with meteorological parameters, according to the Spearman correlation coefficients. Conversely, several potential plant pathogens were strongly and positively correlated with temperature and wind speed and direction both in winter and in spring. The number of strong relationships between presumptive (human and plant) pathogens and non-pathogens, and meteorological parameters slightly increased from winter to spring. The sample chemical composition also varied from winter to spring. Some potential human and plant pathogens were correlated with chemicals mainly associated with marine aerosol and/or with soil dust, likely because terrestrial and aquatic environments were the main habitats of the detected bacterial species. The carrier role on the species seasonal variability was also investigated
Fak signaling in rhabdomyosarcoma
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of children and adolescents. The fusion-positive (FP)-RMS variant expressing chimeric oncoproteins such as PAX3-FOXO1 and PAX7-FOXO1 is at high risk. The fusion negative subgroup, FN-RMS, has a good prognosis when non-metastatic. Despite a multimodal therapeutic approach, FP-RMS and metastatic FN-RMS often show a dismal prognosis with 5-year survival of less than 30%. Therefore, novel targets need to be discovered to develop therapies that halt tumor progression, reducing long-term side effects in young patients. Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that regulates focal contacts at the cellular edges. It plays a role in cell motility, survival, and proliferation in response to integrin and growth factor receptors’ activation. FAK is often dysregulated in cancer, being upregulated and/or overactivated in several adult and pediatric tumor types. In RMS, both in vitro and preclinical studies point to a role of FAK in tumor cell motility/invasion and proliferation, which is inhibited by FAK inhibitors. In this review, we summarize the data on FAK expression and modulation in RMS. Moreover, we give an overview of the approaches to inhibit FAK in both preclinical and clinical cancer settings
Development of a self-powered piezo-resistive smart insole equipped with low-power BLE connectivity for remote gait monitoring
The evolution of low power electronics and the availability of new smart materials are opening new frontiers to develop wearable systems for medical applications, lifestyle monitoring, and performance detection. This paper presents the development and realization of a novel smart insole for monitoring the plantar pressure distribution and gait parameters; indeed, it includes a piezoresistive sensing matrix based on a Velostat layer for transducing applied pressure into an electric signal. At first, an accurate and complete characterization of Velostat-based pressure sensors is reported as a function of sizes, support material, and pressure trend. The realization and testing of a low-cost and reliable piezoresistive sensing matrix based on a sandwich structure are discussed. This last is interfaced with a low power conditioning and processing section based on an Arduino Lilypad board and an analog multiplexer for acquiring the pressure data. The insole includes a 3- axis capacitive accelerometer for detecting the gait parameters (swing time and stance phase time) featuring the walking. A Bluetooth Low Energy (BLE) 5.0 module is included for transmitting in real-time the acquired data toward a PC, tablet or smartphone, for displaying and processing them using a custom Processing® application. Moreover, the smart insole is equipped with a piezoelectric harvesting section for scavenging energy from walking. The onfield tests indicate that for a walking speed higher than 1 ms−1, the device’s power requirements (i.e., P = 5.84 mW ) was fulfilled. However, more than 9 days of autonomy are guaranteed by the integrated 380-mAh Lipo battery in the total absence of energy contributions from the harvesting section
A rapid and simple uhplc-ms/ms method for quantification of plasma globotriaosylsphingosine (Lyso-gb3)
Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by α-galactosidase A gene (GLA) mutations, resulting in loss of activity of the lysosomal hydrolase, α-galactosidase A (α-Gal A). As a result, the main glycosphingolipid substrates, globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3), accumulate in plasma, urine, and tissues. Here, we propose a simple, fast, and sensitive method for plasma quantification of lyso-Gb3, the most promising secondary screening target for FD. Assisted protein precipitation with methanol using Phree cartridges was performed as sample pre-treatment and plasma concentrations were measured using UHPLC-MS/MS operating in MRM positive electrospray ionization. Method validation provided ex-cellent results for the whole calibration range (0.25–100 ng/mL). Intra-assay and inter-assay accuracy and precision (CV%) were calculated as <10%. The method was successfully applied to 55 plasma samples obtained from 34 patients with FD, 5 individuals carrying non-relevant polymorphisms of the GLA gene, and 16 healthy controls. Plasma lyso-Gb3 concentrations were larger in both male and female FD groups compared to healthy subjects (p < 0.001). Normal levels of plasma lyso-Gb3 were observed for patients carrying non-relevant mutations of the GLA gene compared to the control group (p = 0.141). Dropping the lower limit of quantification (LLOQ) to 0.25 ng/mL allowed us to set the optimal plasma lyso-Gb3 cut-off value between FD patients and healthy controls at 0.6 ng/mL, with a sensitivity of 97.1%, specificity of 100%, and accuracy of 0.998 expressed by the area under the ROC curve (C.I. 0.992 to 1.000, p-value < 0.001). Based on the results obtained, this method can be a reliable tool for early phenotypic assignment, assessing diagnoses in patients with borderline GalA activity, and confirming non-relevant mutations of the GLA gene
Growth factor-binding compounds and methods of use
Growth factor binding compounds having a plurality of acyclic isophthalic acid groups attached to a non-peptide organic scaffold and pharmaceutical compositions of the same are disclosed. Methods of administering and using the growth factor binding compounds or the growth factor binding compositions are also taught. These novel growth factor binding compounds are useful for treating angiogenesis, excessive cellular proliferation, tumor growth, and a combination thereof as well as inhibiting growth factor binding to cells and phosphorylation
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