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1.
Acta Neuropathol ; 144(4): 603-614, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35947184

RESUMO

Neuropathologic criteria for progressive supranuclear palsy (PSP) proposed by a National Institute of Neurological Disorders and Stroke (NINDS) working group were published in 1994 and based on the presence of neurofibrillary tangles in basal ganglia and brainstem. These criteria did not stipulate detection methods or incorporate glial tau pathology. In this study, a group of 14 expert neuropathologists scored digital slides from 10 brain regions stained with hematoxylin and eosin (H&E) and phosphorylated tau (AT8) immunohistochemistry. The cases included 15 typical and atypical PSP cases and 10 other tauopathies. Blinded to clinical and neuropathological information, raters provided a categorical diagnosis (PSP or not-PSP) based upon provisional criteria that required neurofibrillary tangles or pretangles in two of three regions (substantia nigra, subthalamic nucleus, globus pallidus) and tufted astrocytes in one of two regions (peri-Rolandic cortices, putamen). The criteria showed high sensitivity (0.97) and specificity (0.91), as well as almost perfect inter-rater reliability for diagnosing PSP and differentiating it from other tauopathies (Fleiss kappa 0.826). Most cases (17/25) had 100% agreement across all 14 raters. The Rainwater Charitable Foundation criteria for the neuropathologic diagnosis of PSP feature a simplified diagnostic algorithm based on phosphorylated tau immunohistochemistry and incorporate tufted astrocytes as an essential diagnostic feature.


Assuntos
Paralisia Supranuclear Progressiva , Tauopatias , Humanos , Emaranhados Neurofibrilares/patologia , Neuropatologia , Reprodutibilidade dos Testes , Paralisia Supranuclear Progressiva/diagnóstico , Paralisia Supranuclear Progressiva/patologia , Tauopatias/diagnóstico , Tauopatias/patologia , Proteínas tau
2.
Arch Environ Contam Toxicol ; 76(2): 331-345, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30430193

RESUMO

This work analyses levels of particles PM10 and PM2.5 recorded at four air-quality monitoring stations located in the urban area of Valladolid (Spain) during 2015-2016. To achieve this, the evolution of particle concentrations at different time scales was determined. Average concentrations ranged from 15.3 to 17.6 µg m-3 for PM10 and between 8.9 and 14.8 µg m-3 for PM2.5. The highest monthly means were recorded in autumn and winter. The difference between mean concentrations at weekends and on weekdays for PM10 was around 3 µg m-3 at most of the measuring stations and was 1 µg m-3 for PM2.5. Two concentration peaks were found during the day, one in the morning and the other in the evening, which evidenced the influence of traffic and other anthropogenic activities on PM concentrations. Their mean values were approximately 21 and 17-21 µg m-3, respectively, for PM10. Mean maximum values for PM2.5 were 12 µg m-3, except at one of the measuring sites, with 17 µg m-3 for the morning maximum and 1 µg m-3 more for the nocturnal peak. In addition, the impact of long-distance transport of air masses in the study area was analysed by applying a HYSPLIT trajectory model, taking into account backward trajectories of European, African, and Atlantic origins as well as local conditions. In particular, high concentration events due to Saharan dust intrusions are presented. Finally, background levels of particle concentrations estimated at most sampling areas were around 15 and 7.7 µg m-3 for the PM10 and PM2.5 particle fractions, respectively.


Assuntos
Poluentes Atmosféricos/análise , Material Particulado/análise , Monitoramento Ambiental , Tamanho da Partícula , Espanha
3.
J Environ Manage ; 209: 37-45, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29275283

RESUMO

CO2 and CH4 evolution is usually linked with sources, sinks and their changes. However, this study highlights the role of meteorological variables. It aims to quantify their contribution to the trend of these greenhouse gases and to determine which contribute most. Six years of measurements at a semi-natural site in northern Spain were considered. Three sections are established: the first focuses on monthly deciles, the second explores the relationship between pairs of meteorological variables, and the third investigates the relationship between meteorological variables and changes in CO2 and CH4. In the first section, monthly outliers were more marked for CO2 than for CH4. The evolution of monthly deciles was fitted to three simple expressions, linear, quadratic and exponential. The linear and exponential are similar, whereas the quadratic evolution is the most flexible since it provided a variable rate of concentration change and a better fit. With this last evolution, a decrease in the change rate was observed for low CO2 deciles, whereas an increasing change rate prevailed for the rest and was more accentuated for CH4. In the second section, meteorological variables were provided by a trajectory model. Backward trajectories from 1-day prior to reaching the measurement site were used to calculate distance and direction averages as well as the recirculation factor. Terciles of these variables were determined in order to establish three intervals with low, medium and high values. These intervals were used to classify the variables following their interval widths and skewnesses. The best correlation between pairs of meteorological variables was observed for the average distance, in particular with horizontal wind speed. Sinusoidal relationships with the average direction were obtained for average distance and for vertical wind speed. Finally, in the third section, the quadratic evolution was considered in each interval of all the meteorological variables. As regards the main result, the greatest increases were obtained for high potential temperature for both gases followed by low and medium boundary layer height for CO2 and CH4, respectively. Combining both meteorological variables provided increases of 22 ± 9 and 0.070 ± 0.019 ppm for CO2 and CH4, respectively, although the number of observations affected is small, around 7%.


Assuntos
Dióxido de Carbono , Metano , Tempo (Meteorologia) , Poluentes Atmosféricos , Espanha , Vento
5.
Environ Monit Assess ; 186(5): 2823-34, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24366818

RESUMO

Continuous methane, CH4, concentrations were measured in a rural area of the upper Spanish plateau from June 2010 to May 2012 by cavity ring-down spectroscopy technique. The results obtained have proven the local impact of anthropogenic nearby sources on CH4 concentrations, and evidence a significant influence on the overall mean, averaged daily and seasonal patterns recorded at the measuring site. The positive anomalies in CH4 concentrations, statistically significant at 95 %, in the southeast sector, defined here as ESE, SE, SSE and S sectors, have been attributed to the contribution of the Valladolid urban plume and the urban landfill. Based on this finding, CH4 background levels were associated to the concentrations recorded in the remaining un-disturbed sectors. CH4 means of the overall data set, the southeast sector and background sectors yielded average means of 1,894.1, 1,927.9 and 1,887.1 ppb, respectively. The diurnal and seasonal patterns of the overall data set and background concentrations have shown that CH4 concentrations are mainly dominated by its reaction with OH radicals. Maximum hourly concentrations were reached during night-time and early morning, 5-7 h, whereas minimum concentrations were recorded at 16 h. Maximum and minimum monthly means were recorded in January and July, respectively. The diurnal and seasonal amplitudes, namely, peak-to-peak means, of background concentrations were 25.1 and 48.1 ppb, respectively. These values were significantly lower than those obtained for the overall data set, 42.9 and 58.1 ppb, revealing the significant role of local influences on CH4 concentrations despite the low frequency of southeast winds recorded at the measuring site, 16.9 %.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Metano/análise , Poluição do Ar/estatística & dados numéricos , Espanha , Vento
6.
Cureus ; 15(10): e47900, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38034262

RESUMO

Ectopic pregnancies, characterized by the implantation of a fertilized ovum outside the uterine cavity, typically occur in the fallopian tubes. However, rare cases have been reported where implantation occurs in atypical locations. Round ligament pregnancy, a rare form of ectopic pregnancy, poses significant risks and can lead to life-threatening complications. This case report describes the presentation and management of a 31-year-old gravida four, para two (G4P2012) female who presented with acute left lower quadrant and pelvic pain. The patient's medical history included a prior bilateral salpingectomy. Physical examination revealed severe left lower quadrant tenderness with guarding. A positive urine pregnancy test and elevated serum quantitative beta-human chorionic gonadotrophin level of 1,735 mIU/mL (normal range: <5 mIU/mL) confirmed pregnancy. Transvaginal ultrasound revealed an empty intrauterine cavity with no gestational sac or fetal pole. A 2 cm cystic structure was identified attached to the left ovary. Ectopic pregnancy was diagnosed, methotrexate was administered, and the patient was discharged with a scheduled outpatient follow-up. However, she returned to the emergency room within 48 hours reporting persistent pelvic pain. At this moment, it was decided that emergent surgical intervention was required. The surgical exploration confirmed the presence of a ruptured ectopic pregnancy in the round ligament, requiring excision and hemostasis. This case report highlights the importance of considering abnormal localization of ectopic pregnancy as a differential diagnosis in women presenting with pelvic pain, even after bilateral salpingectomies. It emphasizes the challenges in diagnosis and management when ectopic pregnancy occurs in atypical sites and highlights the necessity for vigilant follow-up and prompt surgical intervention when medical management fails.

7.
J Anim Ecol ; 81(2): 472-82, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22092379

RESUMO

1. Documenting species abundance distributions in natural environments is critical to ecology and conservation biology. Tropical forest insect faunas vary in space and time, and these partitions can differ in their contribution to overall species diversity. 2. In the Neotropics, the Central American butterfly fauna is best known in terms of general natural history, but butterfly community diversity is best documented by studies on South American fruit-feeding butterflies. Here, we present the first long-term study of fruit-feeding nymphalid species diversity from Central America and provide a unique comparison between Central and South American butterfly communities. 3. This study used 60 months of sampling among multiple spatial and temporal partitions to assess species diversity in a Costa Rican rainforest butterfly community. Abundance distributions varied significantly at the species and higher taxonomic group levels, and canopy and understorey samples were found to be composed of distinct species assemblages. 4. Strong similarities in patterns of species diversity were found between this study and one from Ecuador; yet, there was an important difference in how species richness was distributed in vertical space. In contrast to the Ecuadorian site, Costa Rica had significantly higher canopy richness and lower understorey richness. 5. This study affirms that long-term sampling is vital to understanding tropical insect species abundance distributions and points to potential differences in vertical structure among Central and South American forest insect communities that need to be explored.


Assuntos
Biota , Borboletas/fisiologia , Ecossistema , Animais , Costa Rica , Equador , Preferências Alimentares , Frutas , Dinâmica Populacional , Estações do Ano
8.
J Environ Manage ; 113: 417-25, 2012 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-23083692

RESUMO

CO(2) transport in the low atmosphere near the surface at night was analysed using spatial procedures applied to back trajectories. Concentration and meteorological data were obtained at a rural site during a seven and a half month campaign. Daily evolution of CO(2) skewness showed positive values during the night and negative values during the day. One concentration and one recirculation factor, an indicator of local recirculation, were associated with each back trajectory calculated during the night to study source and meteorological influences on concentrations recorded. Moreover, four procedures were used to analyse the trajectories, and their strengths and weaknesses were also investigated. (1) The nonparametric trajectory analysis applied with two weight functions successfully marked the most contributing region. (2) Hexagonal cells were used to account for radial distribution of trajectories. The potential source contribution function calculated in these cells highlighted the influence of the source against meteorology, this procedure therefore proving the best to mark the source direction. (3) Trajectory sector analysis revealed the most contributing wind sector and emphasised the role of recirculation in the E-S sectors. (4) Cluster analysis grouped neighbouring trajectories and was the most flexible procedure to classify them, providing a contrast of around 12 ppm between medians obtained in the SE cluster and the least contributing group.


Assuntos
Dióxido de Carbono/análise , Monitoramento Ambiental/métodos , Análise por Conglomerados , Modelos Teóricos , Espanha
9.
Sci Total Environ ; 819: 153129, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35041963

RESUMO

CO2 and CH4 outliers may have a noticeable impact on the trend of both gases. Nine years of measurements since 2010 recorded at a rural site in northern Spain were used to investigate these outliers. Their influence on the trend was presented and two limits were established. No more than 23.5% of outliers should be excluded from the measurement series in order to obtain representative trends, which were 2.349 ± 0.012 ppm year-1 for CO2 and 0.00879 ± 0.00004 ppm year-1 for CH4. Two types of outliers were distinguished. Those above the trend line and the rest below the trend line. Outliers were described by skewed distributions where the Weibull distribution figures prominently in most cases. A qualitative procedure was presented to exclude the worst fits, although five statistics were considered to select the best fit. In this case, the modified Nash-Sutcliffe efficiency is prominent. Finally, three symmetrical distributions were added to fit the observations when outliers are excluded, with the Gaussian and beta distributions providing the best fits. As a result, certain skewed functions, such as the lognormal distribution, whose use is frequent for air pollutants, could be questioned in certain applications.


Assuntos
Poluentes Atmosféricos , Dióxido de Carbono , Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Humanos , Metano/análise , População Rural , Espanha
10.
Med Eng Phys ; 110: 103919, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36564142

RESUMO

This paper is aimed at identifying by means of micro-CT the microstructural differences between normal and degenerative mitral marginal chordae tendineae. The control group is composed of 21 normal chords excised from 14 normal mitral valves from heart transplant recipients. The experimental group comprises 22 degenerative fibroelastic chords obtained at surgery from 11 pathological valves after mitral repair or replacement. In the control group the superficial endothelial cells and spongiosa layer remained intact, covering the wavy core collagen. In contrast, in the experimental group the collagen fibers were arranged as straightened thick bundles in a parallel configuration. 100 cross-sections were examined by micro-CT from each chord. Each image was randomized through the K-means machine learning algorithm and then, the global and local Shannon entropies were obtained. The optimum number of clusters, K, was estimated to maximize the differences between normal and degenerative chords in global and local Shannon entropy; the p-value after a nested ANOVA test was chosen as the parameter to be minimized. Optimum results were obtained with global Shannon entropy and 2≤K≤7, providing p < 0.01; for K=3, p = 2.86·10-3. These findings open the door to novel perioperative diagnostic methods in order to avoid or reduce postoperative mitral valve regurgitation recurrences.


Assuntos
Células Endoteliais , Insuficiência da Valva Mitral , Humanos , Cordas Tendinosas/patologia , Colágeno , Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/diagnóstico por imagem , Insuficiência da Valva Mitral/cirurgia , Microtomografia por Raio-X
11.
Gene Ther ; 18(6): 546-52, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21228882

RESUMO

We use a novel technique that allows for closed recirculation of vector genomes in the cardiac circulation using cardiopulmonary bypass, referred to here as molecular cardiac surgery with recirculating delivery (MCARD). We demonstrate that this platform technology is highly efficient in isolating the heart from the systemic circulation in vivo. Using MCARD, we compare the relative efficacy of single-stranded (ss) adeno-associated virus (AAV)6, ssAAV9 and self-complimentary (sc)AAV6-encoding enhanced green fluorescent protein, driven by the constitutive cytomegalovirus promoter to transduce the ovine myocardium in situ. MCARD allows for the unprecedented delivery of up to 48 green fluorescent protein genome copies per cell globally in the sheep left ventricular (LV) myocardium. We demonstrate that scAAV6-mediated MCARD delivery results in global, cardiac-specific LV gene expression in the ovine heart and provides for considerably more robust and cardiac-specific gene delivery than other available delivery techniques such as intramuscular injection or intracoronary injection; thus, representing a potential, clinically translatable platform for heart failure gene therapy.


Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Dependovirus/genética , Técnicas de Transferência de Genes , Terapia Genética/métodos , Vetores Genéticos , Miocárdio , Animais , Ponte Cardiopulmonar , Citomegalovirus , Proteínas de Fluorescência Verde/genética , Miocárdio/metabolismo , Ovinos
12.
Naturwissenschaften ; 98(7): 565-74, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21538132

RESUMO

Integral quantities, wind run, S, and recirculation factor, R, useful for describing air flow, are calculated and combined with CO(2) mixing ratios. Meteorological observations were obtained from a RASS sodar and CO(2) mixing ratios from a continuous analyzer installed at a rural site in the upper Spanish plateau. The measuring campaign spread over 3 years and two approaches were followed. The first approach considered integral quantities on a daily basis and two classifications of air flow, to date scarcely used. The first classification distinguished among stagnation, recirculation, and ventilation, the second considering synoptic, meso-, and local scales. Moreover, 52.94% of daily values handled in this paper corresponded to ventilation and 49.70% to synoptic scale. The main goal of this approach is the subsequent link between the two classifications: the synoptic scale was associated with ventilation, mesoscale with recirculation and local scale partially with recirculation. CO(2) observations were distributed in air flow groups following these classifications and mesoscale processes were satisfactorily described since noticeable evidence of transport from nearby cities was observed. In the second approach, S and R pairs were used and CO(2) mixing ratios were distributed following percent intervals of ventilation, calculated by binning these pairs. The main goal of the second approach is to consider only three groups of mixing ratios. In the first group, with high ventilation, mixing ratios were low. With intermediate ventilation, mixing ratios were medium, and with low ventilation mixing ratios were high. A contrast of 21 ppm between the third and first groups was obtained at the 95th percentile. Finally, the second group provided a contrast of 3 ppm between north and south directions and also between east and west attributed to transport from nearby cities.


Assuntos
Movimentos do Ar , Monitoramento Ambiental , Modelos Teóricos , Dióxido de Carbono/análise , Conceitos Meteorológicos , População Rural , Espanha , Vento
13.
Polymers (Basel) ; 13(23)2021 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-34883653

RESUMO

In oil-immersed power transformers, the insulation system is constituted of a dielectric oil-solid combination. The insulation oil generally used is mineral oil; however, this fluid has started to be substituted by natural and synthetic esters due to their higher biodegradability and flash point. The introduction of a new fluid in the insulation system of power transformers requires kinetic models that can estimate the degradation rate of insulation solids. The aim of this work was to go further in quantifying through different kinetic models the deterioration suffered by a commercial cellulose board (PSP 3055), which is one of the solid materials used in the insulation system of oil-filled transformers. The aging study was extended to cellulose board specimens immersed in two different oils (mineral and synthetic ester). It was obtained that there is a lower degradation when synthetic ester is used in the insulation system. Additionally, it can be concluded that the use of mechanical properties to quantify the degradation of the cellulose board through kinetic models provides information about the different behavior shown by PSP 3055 when different fiber direction angles are considered.

14.
Artigo em Inglês | MEDLINE | ID: mdl-34444147

RESUMO

Meteorological variables have a noticeable impact on pollutant concentrations. Among these variables, wind speed is typically measured, although research into how pollutants respond to it can be improved. This study considers nine years of hourly CO2 and CH4 measurements at a rural site, where wind speed values were calculated by the METEX model. Nine wind speed intervals are proposed where concentrations, distribution functions, and daily as well as annual cycles are calculated. Contrasts between local and transported concentrations are around 5 and 0.03 ppm for CO2 and CH4, respectively. Seven skewed distributions are applied, and five efficiency criteria are considered to test the goodness of fit, with the modified Nash-Sutcliffe efficiency proving to be the most sensitive statistic. The Gumbel distribution is seen to be the most suitable for CO2, whereas the Weibull distribution is chosen for CH4, with the exponential function being the worst. Finally, daily and annual cycles are analysed, where a gradual decrease in amplitude is observed, particularly for the daily cycle. Parametric and nonparametric procedures are used to fit both cycles. The latter gave the best fits, with the agreement being higher for the daily cycle, where evolution is smoother than for the annual cycle.


Assuntos
Poluentes Atmosféricos , Vento , Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Monitoramento Ambiental , Humanos , População Rural
15.
Sci Total Environ ; 774: 145665, 2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-33607428

RESUMO

Pollution control is based on an exhaustive knowledge of concentration distributions. This study analyses a detailed database of NO2, O3, PM10 and PM2.5 in England and Wales over the period 2007-2011. Daily and annual means were considered in a 1-km spatial resolution. Histograms revealed a shape like a sawtooth. The interval was wide for NO2 and O3, although with a gap, whilst the particulate matter range was narrow. Spring provided the peak for the O3 annual cycle, whereas minima for the other pollutants were reached in summer. A trend for the annual medians of particulate matter was observed, with a minimum in the period analysed. However, the pattern was uniform for NO2 and O3. Cities appeared as NO2 hot spots and O3 cold spots. Wales stood out as an NO2 clean country, although with high O3 levels. Sources or sinks of particulate matter were not observed, suggesting that more detailed analysis is required. Two NO2 pollution axes were sometimes seen, one in the south from London to Bristol, and the second in the north, from Liverpool to Kingston Upon Hull. No annual spatial pattern was seen for the remaining pollutants beyond the contrast between cities and country sites for O3. Consequently, spatial analysis allows the real impact of pollutant sources be known, although it must be performed with a detailed temporal resolution in order to investigate the extension, quantity, and length of the concentrations calculated.

16.
Gynecol Obstet Fertil Senol ; 48(2): 204-210, 2020 02.
Artigo em Francês | MEDLINE | ID: mdl-31923645

RESUMO

OBJECTIVES: Skeletal remains of pregnant woman whit fetus still in the pelvic region are scarce in the archaeological record. We aimed to review the different cases of maternal and fetal death in the ancient times. METHODS: A review of literature using Medline database and Google about mortality during pregnancy in Prehistory, Antiquity and middle age. The following key words were used: ancient times; paleopathology; immature fetus; medieval; pregnancy; mummies; Antiquity; maternal mortality. RESULTS: Thirty articles were found and we added one personal unpublished case. There were 64 female skeletons with mainly infectious abnormalities (10 dental abscesses and 2 pneumoniae) followed by traumatic lesions (2 frontal fractures and 1 femur luxation). There were 48 fetal remains and 3 twins. We noted 8 obstructed labors (3 breech presentations, 4 transverse lies and one possible shoulder dystocia). CONCLUSIONS: The fact that there were only few cases of maternal deaths with fetal remains raises the questions of the cause of death and the relationship between death and obstetric disorders. Beside the underestimation of these archaecological cases, the reasons of both fetal and maternal death must be looking for among several diseases or anomalies of both or of one of them, related with poor environmental conditions (such as malnutrition and high morbidity from infections) and lack of care the mother and fetus need.


Assuntos
Morte Fetal , Morte Materna/história , Feminino , Morte Fetal/etiologia , História Antiga , História Medieval , Humanos , Morte Materna/etiologia , Mortalidade Materna/história , Paleopatologia , Gravidez
17.
Artigo em Inglês | MEDLINE | ID: mdl-33187359

RESUMO

Although emissions have a direct impact on air pollution, meteorological processes may influence inmission concentration, with the only way to control air pollution being through the rates emitted. This paper presents the close relationship between air pollution and meteorology following the scales of atmospheric motion. In macroscale, this review focuses on the synoptic pattern, since certain weather types are related to pollution episodes, with the determination of these weather types being the key point of these studies. The contrasting contribution of cold fronts is also presented, whilst mathematical models are seen to increase the analysis possibilities of pollution transport. In mesoscale, land-sea and mountain-valley breezes may reinforce certain pollution episodes, and recirculation processes are sometimes favoured by orographic features. The urban heat island is also considered, since the formation of mesovortices determines the entry of pollutants into the city. At the microscale, the influence of the boundary layer height and its evolution are evaluated; in particular, the contribution of the low-level jet to pollutant transport and dispersion. Local meteorological variables have a major influence on calculations with the Gaussian plume model, whilst some eddies are features exclusive to urban environments. Finally, the impact of air pollution on meteorology is briefly commented on.


Assuntos
Poluição do Ar , Monitoramento Ambiental , Meteorologia , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Cidades , Temperatura Alta , Meteorologia/normas , Material Particulado/análise
18.
Sci Total Environ ; 686: 322-331, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31181519

RESUMO

A comparison between monthly CO2 values calculated in the Iberian Peninsula and those measured during six years commencing on October 2010 in the centre of its upper plateau is presented. Gaussian and Epanechnikov kernels are used to calculate CO2 concentration and its growth rate in the study region from values at certain grid points. Slight spatial differences are obtained, revealing that both concentration and growth rate are nearly uniform in the region. However, some intervals were proposed that were represented by bands (strips), distributed meridionally for concentration and zonally for growth rate. Band borders were smoother for the Gaussian kernel than for the Epanechnikov kernel. In addition, the probability distribution function of concentration and growth rate were obtained with both kernels. Temporal analysis is carried out adding a linear evolution for growth rate and a sinusoidal function for the annual cycle. This revealed similar patterns for the region and at the grid point nearest to the measurement site, given by a sinusoidal function with nearly constant amplitude, providing satisfactory agreement. However, measurements showed great dispersion, with the concentration being around 7 ppm higher than for the region. Temporal evolution is characterised by a growth rate of 2.39 ppm yr-1 and a sinusoidal function with an amplitude decrease of 0.25 ppm yr-1.

19.
J Air Waste Manag Assoc ; 58(7): 940-6, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18672718

RESUMO

Continuous carbon dioxide (CO2) measurements over the period 2004-2005 for a rural area in the upper Spanish plateau were examined to characterize the influence of sources and sinks. The diurnal pattern and the annual cycle are presented. The baseline CO2 levels over the time frames researched are determined so as to achieve a more accurate verification of the ambient conditions when uptake is deployed at the site. The results reveal a mean concentration of 384.2 ppm, with 9.8-ppm variability. The mean maximum concentration levels at night, 4:00 a.m. Greenwich Mean Time (GMT), are 390.7 ppm, mainly when atmospheric stability increased. Moreover, mean CO2 levels increase in spring, peaking in May at 388.5 ppm. Concentrations then decline in summer and again increase in autumn, reaching a similar mean value in December. The results also show consistency with vegetation and crop growth, as well as the influence of meteorological conditions, soil features, and human activity in the area. Minimum and maximum CO2 concentrations present a similar but opposite variation, 4.4 ppm x yr(-1), with values decreasing in the latter. Diurnal variation is more pronounced during the growing season and higher in 2004, partly because of abundant rainfall. The lower daily amplitudes in the remaining months are attributed to the reduction in plant and soil respiration processes. The influence of wind on CO2 concentrations has enabled us to identify the contribution of emissions from the cities of Valladolid and Palencia. An increase in mean CO2 concentrations was observed in the, east-southeast, southeast, south-southeast, and south sectors for the former city, and north and east for the latter. The ratio of CO2 increase in the wind sectors influenced by these sources yielded a factor of 1.2 with respect to the relationship between the populations of the two cities.


Assuntos
Poluentes Atmosféricos , Dióxido de Carbono/química , Monitoramento Ambiental , Estações do Ano , Espanha , Fatores de Tempo , Tempo (Meteorologia) , Vento
20.
Sci Total Environ ; 627: 417-426, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29426164

RESUMO

The integrated SCOPE (Soil, Canopy Observation, Photochemistry and Energy balance) model, coupling radiative transfer theory and biochemistry, was applied to a biodiesel crop grown in a Spanish agricultural area. Energy fluxes and CO2 exchange were simulated with this model for the period spanning January 2008 to October 2008. Results were compared to experimental measurements performed using eddy covariance and meteorological instrumentation. The reliability of the model was proven by simulating latent (LE) and sensible (H) heat fluxes, soil heat flux (G), and CO2 exchanges (NEE and GPP). LAI data used as input in the model were retrieved from the MODIS and MERIS sensors. SCOPE was able to reproduce similar seasonal trends to those measured for NEE, GPP and LE. When considering H, the modelled values were underestimated for the period covering July 2008 to mid-September 2008. The modelled fluxes reproduced the observed seasonal evolution with determination coefficients of over 0.77 when LE and H were evaluated. The modelled results offered good agreement with observed data for NEE and GPP, regardless of whether LAI data belonged to MODIS or MERIS, showing slopes of 0.87 and 0.91 for NEE-MODIS and NEE-MERIS, and 0.91 and 0.94 for GPP-MODIS and GPP-MERIS, respectively. Moreover, SCOPE was able to reproduce similar seasonal behaviours to those observed for the experimental carbon fluxes, clearly showing the CO2 sink/source behaviour for the whole period studied.


Assuntos
Brassica rapa/fisiologia , Monitoramento Ambiental/métodos , Modelos Teóricos , Ciclo do Carbono , Dióxido de Carbono , Ecossistema , Reprodutibilidade dos Testes , Espanha
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