3,510 research outputs found
The vertical distribution of aerosols, Saharan dust and cirrus clouds at Rome (Italy) in the year 2001
International audienceA set of 813 lidar profiles of tropospheric aerosol and cirrus clouds extinction and depolarization observed at Rome, Italy, between February 2001 and February 2002 is analyzed and discussed. The yearly record reveals a meaningful contribution of both cirrus clouds (38%) and Saharan dust (12%) to the total optical thickness (OT) of 0.26, at 532 nm. Seasonal analysis shows the planetary boundary layer (PBL) aerosols to be confined below 2 km in winter and 3.8 km in summer, with relevant OT shifting from 0.08 to 0.16, respectively. Cirrus clouds maximize in spring and autumn, in both cases with average OT similar to the PBL aerosols one. With the exception of winter months, Saharan dust is found to represent an important third layer mostly residing between PBL aerosols and cirrus clouds, with yearly average OT~0.03. Saharan dust and cirrus clouds were detected in 20% and in 45% of the observational days, respectively. Validation of the lidar OT retrievals against collocated sunphotometer observations show very good agreement. These results represent one of the few yearly records of tropospheric aerosol vertical profiles available in the literature
Aerosol seasonal variability over the Mediterranean region and relative impact of maritime, continental and Saharan dust particles over the basin from MODIS data in the year 2001
International audienceThe one-year (2001) record of aerosol data from the space borne Moderate Resolution Imaging Spectroradiometer (MODIS) is analyzed focusing on the Mediterranean region. The MODIS aerosol optical thickness standard product (AOT at 550nm) provided over both land and ocean is employed to evaluate the seasonal and spatial variability of the atmospheric particulate over the region. Expected accuracy of the MODIS AOT is (±0.05±0.2xAOT) over land and (±0.03±0.05xAOT) over ocean. The seasonal analysis reveals a significant AOT variability all over the region, with minimum values in Winter (AOT0.2). The spatial variability is also found to be considerable, particularly over land. The impact of some major urban sites and industrialized areas is detectable. For the sole Mediterranean basin, a method (aerosol mask) was implemented to separate the contribution of maritime, continental and desert dust aerosol to the total AOT. Input of both continental and desert dust particles is well captured, showing North-to-South and South-to-North AOT gradients, respectively. A quantitative summary of the AOT seasonal and regional variability is given for different sectors of the Mediterranean basin. Results of this summary were also used to test the aerosol mask assumptions and indicate the method adopted to be suitable for the aerosol type selection. Estimates of the atmospheric aerosol mass load were performed employing specifically-derived mass-to-extinction efficiencies (?). For each aerosol type, a reliable mean ? value was determined on the basis of both lidar measurements of extinction and aerosol models. These estimates indicate a total of 43Mtons of desert dust suspended over the basin during 2001. A comparable value is derived for maritime aerosol. Opposite to the dust case, a minor seasonal variability (within 15%) of maritime aerosol mass is found. This latter result is considered a further check of the suitability of the methodology adopted to separate, on the basis of MODIS data, the three aerosol types which dominate the Mediterranean region
Domain wall displacement in Py square ring for single nanometric magnetic bead detection
A new approach based on the domain wall displacement in confined
ferromagnetic nanostructures for attracting and sensing a single nanometric
magnetic particles is presented. We modeled and experimentally demonstrated the
viability of the approach using an anisotropic magnetoresistance device made by
a micron-size square ring of Permalloy designed for application in magnetic
storage. This detection concept can be suitable to biomolecular recognition,
and in particular to single molecule detection.Comment: 8pages, 3figure
Three-dimensional apoptotic nuclear behavior analyzed by means of field emission in lens scanning electron microscope
Apoptosis is an essential biological function required during embryogenesis, tissue homeostasis, organ development and immune system regulation. It is an active cell death pathway involved in a variety of pathological conditions. During this process cytoskeletal proteins appear damaged and undergo an enzymatic disassembling, leading to formation of apoptotic features. This study was designed to examine the threedimensional chromatin behavior and cytoskeleton involvement, in particular actin re-modeling. HL-60 cells, exposed to hyperthermia, a known apoptotic trigger, were examined by means of a Field Emission in Lens Scanning Electron Microscope (FEISEM). Ultrastructural observations revealed in treated cells the presence of apoptotic patterns after hyperthermia trigger. In particular, three-dimensional apoptotic chromatin rearrangements appeared involving the translocation of filamentous actin from cytoplasm to the nucleus. FEISEM immunogold techniques showed actin labeling and its precise three-dimensional localization in the diffuse chromatin, well separated from the condensed one. The actin presence in dispersed chromatin inside the apoptotic nucleus can be considered an important feature, indispensable to permit the apoptotic machinery evolution
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 Ångstrom exponent (<i>å</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>å</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>å</i>–Δ<i>å</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>å</i>–<i>å</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
An important fingerprint of wildfires on the European aerosol load
Abstract. Wildland fires represent the major source of fine aerosols, i.e., atmospheric particles with diameters <1 μm. The largest numbers of these fires occur in Africa, Asia and South America, but a not negligible fraction also occurs in Eastern Europe and former USSR countries, particularly in the Russian Federation, Ukraine and Kazakhstan. Besides the impact of large forest fires, recent studies also highlighted the crucial role played by routine agricultural fires in Eastern Europe and Russia on the Arctic atmosphere. An evaluation of the impact of these fires over Europe is currently not available. The assessment of the relative contribution of fires to the European aerosol burden is hampered by the complex mixing of natural and anthropogenic particle types across the continent. In this study we use long term (2002–2007) satellite-based fires and aerosol data coupled to atmospheric trajectory modelling in the attempt to estimate the wildfires contribution to the European aerosol optical thickness (AOT). Based on this dataset, we provide evidence that fires-related aerosols play a major role in shaping the AOT yearly cycle at the continental scale. In general, the regions most impacted by wildfires emissions and/or transport are Eastern and Central Europe as well as Scandinavia. Conversely, a minor impact is found in Western Europe and in the Western Mediterranean. We estimate that in spring 5 to 35% of the European fine fraction AOT (FFAOT) is attributable to wildland fires. The estimated impact maximizes in April (20–35%) in Eastern and Central Europe as well as in Scandinavia and in the Central Mediterranean. An important contribution of wildfires to the FFAOT is also found in summer over most of the continent, particularly in August over Eastern Europe (28%) and the Mediterranean regions, from Turkey (34%) to the Western Mediterranean (25%). Although preliminary, our results suggest that this fires-related, continent-wide haze plays a not negligible role on the European radiation budget, and possibly, on the European air quality, therefore representing a clear target for mitigation
Comparação dos efeitos do flunixin meglumine, firocoxib e meloxicam no controle da inflamação após orquiectomia em equinos.
O objetivo do presente estudo foi avaliar e comparar a ação analgésica e
antiinflamatória do flunixin meglumine, firocoxib e do meloxicam em equinos após orquiectomia por meio da avaliação clínico-laboratorial. Foram avaliados 18 cavalos não castrados, de diferentes raças, com 4,99±2,63 anos de idade e
358,62±45,57 kg de peso corporal. Em função do fármaco utilizado após as
castrações, os animais foram distribuídos aleatoriamente em três grupos
experimentais com 06 animais cada: GFM= flunixin meglumine, GF= firocoxib e GM= meloxicam. Amostras de sangue e líquido peritoneal foram colhidas antes (T0) e após as orquiectomias (1, 3, 6, 9, 12, 24, 48, 72, 120 e 168 horas). O líquido peritoneal, obtido através da punção abdominal, foi submetido à análise físico-química e as amostras de sangue, obtidas através da punção jugular, ao eritroleucograma e as provas de funcionalidade renal, hepática e de higidez muscular. Os resultados foram submetidos à análise estatística descritiva e as médias foram comparadas pelo teste SNK a 5% de probabilidade. Após as orquiectomias os animais do GF apresentaram taquicardia e os do GM taquicardia e hipertermia. Leucocitose neutrofílica foi observada nos animais do GFM, GF e GM e monocitose nos animais do GFM e GM. O proteinograma sérico dos três grupos (GFM, GF e GM) revelou hipoproteinemia e a atividade sérica da enzima GGT apresentou queda nos valores no GFM, GF e GM. Os valores de FA foram superiores no GF quando comparados ao GFM e GM (T72 e T120). Quanto às concentrações de AST, os animais do GM apresentaram valores superiores ao GFM e GF. Observou-se ainda aumento na atividade sérica das enzimas CK (T24, T72 e T168) nos animais do GFM, GF e GM. Os animais do GFM e GF apresentaram valores superiores relativos à uréia comparados ao grupo GM (T0, T72 e T120) e em relação à creatinina e o GM apresentou valores superiores ao GFM e GF em todos os tempos avaliado no pós cirúrgico. A coloração do líquido peritoneal antes das orquiectomias (T0) variou de amarelo-palha a amaralo-ouro,
límpido nos grupos GFM, GF e GM e amarelo-palha, vermelho, âmbar e amareloouro com grau de turbidez de límpido a turvo após as orquiectomias. No liquido peritoneal foi observado aumento da proteína total, AST e GGT nos grupos GFM, GF e GM e das enzimas FA nos animais do GM. Avaliou-se ainda a resposta de fase aguda através da determinação da concentração das proteínas de fase aguda (PFAs) no soro sanguíneo e no líquido peritoneal. Foram identificadas as proteínas ceruloplasmina, transferrina, albumina, haptoglobina e α1- glicoproteína ácida. Houve aumento de Cp, Hp, Tr, Alb e AGP nos animais dos três grupos (GFM, GF, GM). Na comparação entre grupos, os valores de Cp e de Tr no sangue e no LP dos animais do GM foram superiores aos GFM e GF. Para a variável Alb os animais do GF apresentaram valores superiores aos animais do GFM e GM em todos os momentos avaliados. O flunixin meglumine e o firocoxib se mostraram com ação superiores em relação ao meloxicam. A orquiectomia desencadeia reação inflamatória em equinos e o proteinograma pode ser utilizado para diagnosticar e monitorar complicações pós-operatórias
Whole-Body Cryostimulation in Fibromyalgia: A Scoping Review
Currently, all available therapies for the control and management of fibromyalgia (FM) are mostly focused on relieving patients’ symptoms and improving their quality of life. The purpose of this review is to provide an up-to-date overview of the evidence supporting the beneficial effects of whole-body cryostimulation (WBC) in patients with FM and evidence-based guidance on the possible adjuvant use of WBC in the treatment of FM. We searched the most recent literature by retrieving 10 eligible studies, 4 of which were abstracts only, from a total of 263 records. Thermal stress caused by cryostimulation induces an analgesic effect, improving pain, redox balance, and inflammatory symptoms in an exercise-mimicking fashion. In addition, it reduces the feeling of fatigue, improves mood, and reduces mental health deterioration with positive consequences on depressive states and improved sleep quality. Although the studies included in this review are not of sufficient quality and quantity to draw definitive conclusions about the effectiveness of WBC in FM, initial evidence indicates WBC as a promising add-on option in the multidisciplinary treatment of FM, due to its rapid action and high patients’ compliance. The application of WBC protocols has the potential to expand therapeutic options for the treatment of FM and related disorders; however, larger, high-quality primary studies are still needed
Observations of AtmosphericGravity Waves using Airglow All-sky CCD Imager At Cachoeira Paulista (23° S, 45° W)
An all-sky CCD imager for OH, O2 and OI (557.7 nm) airglow was operated at Cachoeira Paulista (CP), Brazil, (23° S, 45° W), from October 1998 to September 1999, with Utah State University. Dominant gravity wave components are extracted and seasonal variations are investigated. These waves have typically short horizontal wavelengths (5 - 60 km), short periods (5 - 35 minutes), and horizontal phase speeds of 1 - 80 m/s. Band-type waves of horizontal wavelength between 10 and 60 km showed clear seasonal dependence in the horizontal propagation direction to southeast in summer and to northwest in winter. The direction of propagation changed in mid-March and at the end of September. The gravity waves over CP may be generated by the strong tropospheric convection. In summer, this region extends along a line approximately between (10° S, 45° W) and (40° S, 78° W), from northern Argentina to the Brazilian northeast, with an accentuated distribution over central Brazil. CP is below this region. In winter, the convective region is located below CP mainly over the sea and there is no convection in central Brazil region above CP. Thus the anisotropy of the wave propagation direction is mainly due to source location and wave filtering by stratospheric winds
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