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1.
J Environ Manage ; 282: 111963, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33465718

RESUMO

Pollen grains emitted by urban vegetation are the main primary biological airborne particles (PBAPs) which alter the biological quality of urban air and have a significant impact on human health. This work analyses the interactions which exist between pollen-type PBAPs, meteorological variables, and air pollutants in the urban atmosphere so that the complex relationships and trends in future scenarios of changing environmental conditions can be assessed. For this study, the 1992-2018 pollen data series from the city of Granada (southeast Spain) was used, in which the dynamics of the total pollen as well as the 8 main pollen types (Cupressaceae, Olea, Pinus, Platanus, Poaceae, Populus, Quercus and Urticaceae) were analysed. The trend analysis showed that all except Urticaceae trended upward throughout the series. Spearman's correlations with meteorological variables showed that, in general, the most influential variables on the pollen concentrations were the daily maximum temperature, relative humidity, water vapor pressure, global radiation, and insolation, with different effects on different pollen types. Parallel analysis by neural networks (ANN) confirmed these variables as the predominant ones, especially global radiation. The correlation with atmospheric pollutants revealed that ozone was the pollutant with the highest influence, although some pollen types also showed correlation with NO2, SO2, CO and PM10. The Generalized Linear Models (GLM) between pollen and pollutants also indicated O3 as the most prominent variable. These results highlight the active role that pollen-type PBAPs have on urban air quality by establishing their interactions with meteorological variables and pollutants, thereby providing information on the behaviour of pollen emissions under changing environmental conditions.


Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Poluentes Atmosféricos/análise , Alérgenos/análise , Cidades , Monitoramento Ambiental , Humanos , Estações do Ano , Espanha
2.
Sci Total Environ ; : 143100, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33121775

RESUMO

Understanding the activation properties of aerosol particles as cloud condensation nuclei (CCN) is important for the climate and hydrological cycle, but their properties are not fully understood. In this study, the CCN activation properties of aerosols are investigated at two different sites in southern Spain: an urban background station in Granada and a high altitude mountain station in the Sierra Nevada National Park, with a horizontal separation of 21 km and vertical separation of 1820 m. CCN activity at the urban environment is driven by primary sources, mainly road traffic. Maximum CCN concentrations occurred during traffic rush hours, although this is also when the activation fraction is lowest. This is due to the characteristics of the rush hour aerosol consisting of ultrafine and less hygroscopic particles. In contrast, the mountain site exhibited larger and more hygroscopic particles, with CCN activity driven by the joint effect of new particle formation (NPF) and vertical transport of anthropogenic particles from Granada urban area by orographic buoyant upward flow. This led to the maximum concentrations of CCN and aerosol particles occurring at midday at the mountain site. Clear differences in the diurnal evolution of CCN between NPF events and non-event days were observed at the Sierra Nevada station, demonstrating the large contribution of NPF to CCN concentrations, especially at high supersaturations. The isolated contribution of NPF to CCN concentration has been estimated to be 175% higher at SS = 0.5% relative to what it would be without NPF. We conclude that NPF could be the major source of CCN at this mountain site. Finally, two empirical models were used to parameterize CCN concentration in terms of aerosol optical or physical parameters. The models can explain measurements satisfactorily at the urban station. At the mountain site both models cannot reproduce satisfactorily the observations at low SS.

3.
Photochem Photobiol ; 92(1): 215-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26449745

RESUMO

This study focuses on the analysis of the sensitivity of UV erythemal radiation (UVER) to variations in the total ozone column (TOC) under different sky conditions at Granada (southeastern Spain). The sensitivity is studied both in relative terms by means of the Radiation Amplification Factor (RAF) and in absolute terms using the Ozone Efficiency (OE). These two variables are determined for diverse sky conditions characterized by the cloud cover information given by a sky camera (in oktas) and the cloud optical depth (COD) estimated from global solar radiation measurements. As expected, in absolute terms, the TOC variations cause substantially smaller UVER changes during completely overcast situations than during cloud-free cases. For instance, the OE (SZA = 30°, TOC = 290 DU) decreases from 0.68 mW m(-2) per unit of TOC (0 oktas) to 0.50 mW m(-2) per unit of TOC (8 oktas). However, the opposite is observed when the analysis is performed in relative terms. Thus, the RAF (determined for SZA cases below 80°) increases from 1.1 for cloud-free cases (0 oktas) to 1.4 for completely overcast situations (8 oktas). This opposite behavior is also found when both RAF and OE are analyzed as functions of COD. Thus, while the OE strongly decreases with increasing COD, the RAF increases as COD increases.

4.
Science ; 339(6127): 1572-8, 2013 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-23449996

RESUMO

Winter storms in California's Sierra Nevada increase seasonal snowpack and provide critical water resources and hydropower for the state. Thus, the mechanisms influencing precipitation in this region have been the subject of research for decades. Previous studies suggest Asian dust enhances cloud ice and precipitation, whereas few studies consider biological aerosols as an important global source of ice nuclei (IN). Here, we show that dust and biological aerosols transported from as far as the Sahara were present in glaciated high-altitude clouds coincident with elevated IN concentrations and ice-induced precipitation. This study presents the first direct cloud and precipitation measurements showing that Saharan and Asian dust and biological aerosols probably serve as IN and play an important role in orographic precipitation processes over the western United States.


Assuntos
Aerossóis/química , Altitude , Atmosfera/química , Poeira , Congelamento , Gelo , África do Norte , Ásia , Bactérias , Modelos Químicos , Chuva/química , Estações do Ano , Neve/química , Estados Unidos
5.
Appl Opt ; 47(34): H182-9, 2008 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-19037341

RESUMO

A new method is presented for retrieval of the aerosol and cloud optical depth using a CCD camera equipped with a fish-eye lens (all-sky imager system). In a first step, the proposed method retrieves the spectral radiance from sky images acquired by the all-sky imager system using a linear pseudoinverse algorithm. Then, the aerosol or cloud optical depth at 500 nm is obtained as that which minimizes the residuals between the zenith spectral radiance retrieved from the sky images and that estimated by the radiative transfer code. The method is tested under extreme situations including the presence of nonspherical aerosol particles. The comparison of optical depths derived from the all-sky imager with those retrieved with a sunphotometer operated side by side shows differences similar to the nominal error claimed in the aerosol optical depth retrievals from sunphotometer networks.

6.
Psicoactiva ; 3(1): 49-60, ene.-jun. 1989. tab
Artigo em Espanhol | LILACS, LIPECS | ID: lil-88931

RESUMO

Se estudia la tasa de transporte de litio (TTLi) "in vitro" en 50 pacientes farmacodependientes hospitalizados (PFD), con historia clínica psiquátrica y diagnóstico según los criterios del DSM III. Los resultados muestran que la media de la TTLi en los PFD es sgnificativamente mayor que la del grupo control. El 68% de los PFD presenta antecedentes de enfermedad afectiva (E.A.) y el mismo porcentaje tiene TTLi elevada. Los autores recomiendan determinar la TTLi en farmacodependientes, como un elemento de juicio importante para precisar la enfermedad de fondo


Assuntos
Criança , Adolescente , Adulto , Humanos , Masculino , Feminino , Transtorno Bipolar/etiologia , Transtornos Relacionados ao Uso de Substâncias , Lítio/sangue , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/genética , Grupos Controle
7.
s.l; INDES; 1988. 68 p. ilus.
Monografia em Espanhol | LILACS | ID: lil-65852

RESUMO

En este documento se da a conocer las ponencias que constituyen el marco de análisis y discusión en la Reunión de Trabajo que el Grupo Peruano sobre Conducción Sectorial y Liderazgo organizó para conceptualizar y unificar criterios y establecer las bases de un Programa Nacional, así como las conclusiones y recomendaciones


Assuntos
Liderança , Estratégias , Peru
8.
Rev. neuropsiquiatr ; 48(3/4): 152-60, sept.-dic. 1985. tab
Artigo em Espanhol | LILACS, LIPECS | ID: lil-57039

RESUMO

La catalasa es una de las enzimas que detoxifican las neuronas aminérgigicas del peróxido de hidrógeno producido en su metabolismo. Se ha medido la actividad de dicha enzima en 17 regiones del cerebro de ratas de diferentes edades (20, 35, 90 y 180 días). Se encuentra elevada actividad de la enzima en la sustancia negra, el hipotálamo y la pienal, hallazgo este útimo novedoso; en las dos primeras regiones, empero, tal actividad decrece marcadamente con la edad. En la sustancia negra, el decremento es de un 82% entre los 20 y 180 días de edad; se discuten las implicancias de ello para la comprensión de la enfermedad de Parkinson


Assuntos
Ratos , Animais , Catalase/metabolismo , Cérebro/metabolismo , Neurônios/metabolismo , Fatores Etários
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