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The Kathmandu Valley in south Asia is considered as one of the global "hot spots" in terms of urban air pollution. It is facing severe air quality problems as a result of rapid urbanization and land use change, socioeconomic transformation, and high population growth. In this paper, we present the first full year (February 2013-January 2014) analysis of simultaneous measurements of two shortlived climate forcers/pollutants (SLCF/P), i.e., ozone (O3) and equivalent black carbon (hereinafter noted as BC) and aerosol number concentration at Paknajol, in the city center of Kathmandu. The diurnal behavior of equivalent BC and aerosol number concentration indicated that local pollution sources represent the major contributions to air pollution in this city. In addition to photochemistry, the planetary boundary layer (PBL) and wind play important roles in determining O3 variability, as suggested by the analysis of seasonal changes of the diurnal cycles and the correlation with meteorological parameters and aerosol properties. Especially during pre-monsoon, high values of O3 were found during the afternoon/evening. This could be related to mixing and entrainment processes between upper residual layers and the PBL. The high O3 concentrations, in particular during pre-monsoon, appeared well related to the impact of major open vegetation fires occurring at the regional scale. On a synoptic-scale perspective, westerly and regional atmospheric circulations appeared to be especially conducive for the occurrence of the high BC and O3 values. The very high values of SLCF/P, detected during the whole measurement period, indicated persisting adverse air quality conditions, dangerous for the health of over 3 million residents of the Kathmandu Valley, and the environment. Consequently, all of this information may be useful for implementing control measures to mitigate the occurrence of acute pollution levels in the Kathmandu Valley and surrounding area. [ABSTRACT FROM AUTHOR]

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that occurs in two clinically indistinguishable forms: sporadic (SALS) and familial (FALS), the latter linked to several gene mutations, mostly inheritable in a dominant manner. Nearly 20% of FALS forms are linked to mutations in the Cu/Zn superoxide dismutase (SOD1) gene. Research on ALS relies on transgenic models and particularly on mice carrying a glycine-to-alanine conversion at the 93rd codon (G93A) of the hSOD1 gene. Although G93A transgenic mice have been widely employed in clinical trials and basic research, doubts have been recently raised from numerous reliable sources about their suitability to faithfully reproduce human disease. Besides, the scientific community has already foreseen swine as an attractive and alternative model to nonhuman primates for modeling human diseases due to closer anatomical, physiological and biochemical features of swine rather than rodents to humans. On this basis, we have produced the first swine ALS model by in vitro transfection of cultured somatic cells combined with somatic cell nuclear transfer (SCNT). To achieve this goal we developed a SOD1G93A (superoxide dismutase 1 mutated in Gly93-Ala) vector, capable of promoting a high and stable transgene expression in primary porcine adult male fibroblasts (PAF). After transfection, clonal selection and transgene expression level assessment, selected SOD1G93A PAF colonies were used as nuclei donors in SCNT procedures. SOD1G93A embryos were transferred in recipient sows, and pregnancies developed to term. A total of 5 piglets survived artificial hand raising and weaning and developed normally, reaching adulthood. Preliminary analysis revealed transgene integration and hSOD1G93A expression in swine tissues and 360° phenotypical characterization is ongoing. We believe that our SOD1G93A swine would provide an essential bridge between the fundamental work done in rodent models and the reality of treating ALS. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

We analysed the variability of equivalent black carbon (BC) and ozone (O3) at the global WMO/GAW station Nepal Climate Observatory-Pyramid (NCO-P, 5079 m a.s.l.) in the southern Himalayas, for evaluating the possible contribution of open vegetation fires to the variability of these short-lived climate forcers/pollutants (SLCF/SLCP) in the Himalayan region. We found that 162 days (9% of the data-set) were characterised by acute pollution events with enhanced BC and O3 in respect to the climatological values. By using satellite observations (MODIS fire products and the USGS Land Use Cover Characterization) and air mass back-trajectories, we deduced that 56% of these events were likely to be affected by emissions from open fires along the Himalayas foothills, the Indian Subcontinent and the Northern Indo-Gangetic Plain. These results suggest that open fire emissions are likely to play an important role in modulating seasonal and inter-annual BC and O3 variability over south Himalayas. [Copyright &y& Elsevier]

This work investigates the variability of ozone (O3), carbon monoxide (CO) and equivalent black carbon (BC) at the Italian Climate Observatory "O. Vittori" (ICO- OV), part of the Mt. Cimone global GAW-WMO station (Italy). For this purpose, ICO-OV observations carried out in the period January 2007-June 2009, have been analyzed and correlated with the outputs of the FLEXPART Lagrangian dispersion model to specifically evaluate the influence of biomass burning (BB) and anthropogenic emissions younger than 20 days. During the investigation period, the average O3, CO and BC at ICO-OV were 54±3ppb, 122±7ppb and 213±34 ng m-3 (mean±expanded uncertainty with p < 95 %), with clear seasonal cycles characterized by summer maxima and winter minima for O3 and BC and spring maximum and summer minimum for CO. According to FLEXPART outputs, BB impact is maximized during the warm months from July to September but appeared to have a significant contribution to the observed tracers only during specific transport events. We characterised in detail five "representative" events with respect to transport scales (i.e. global, regional and local), source regions and O3, CO and BC variations. For these events, very large variability of enhancement ratios O3/CO (from -0.22 to 0.71) and BC/CO (from 2.69 to 29.83 ng m-3 ppb-1) were observed. CO contributions related with anthropogenic emissions (COant) contributed to 17.4 % of the mean CO value observed at ICO-OV, with the warm months appearing particularly affected by transport events of air-masses rich in anthropogenic pollution. The proportion of tracer variability that is described by FLEXPART COant peaked to 37% (in May-September) for CO, 19% (in May-September) for O3 and 32 % (in January-April) for BC. During May-September, the analysis of the correlation among CO, O3 and BC as a function of the COant indicated that ICO-OV was influenced by air-masses rich in anthropogenic pollution transported from the regional to the global scale. On the other side, CO and O3 were negatively correlated during October-December, when FLEXPART does not show significant presence of re- cent anthropogenic emissions and only a few observations are characterized by enhanced BC. Such behaviour may be attributed to an ensemble of processes concurrent in enhancing O3 with low CO (upper troposphere/lower stratosphere intrusions) and to O3 titration by NO in polluted air-masses along with lower photochemical activity. An intermediate situation occurs in January-April when CO and O3 were almost uncorrelated and BC enhancements were associated to relatively old (10 days) anthropogenic emissions. [ABSTRACT FROM AUTHOR]

This work investigates the variability of ozone (O3), carbon monoxide (CO) and equivalent black carbon (BC) concentrations at the Italian Climate Observatory "O. Vittori" (ICO-OV), part of the Mt. Cimone global GAW-WMO station (Italy). For this purpose, ICO-OV observations carried out in the period January 2007-June 2009, have been analysed and correlated with the output of the FLEXPART Lagrangian dispersion model to specifically evaluate the influence of biomass burning (BB) and anthropogenic emissions younger than 20 days. During the investigation period, the average O3, CO and BC concentrations at ICO-OV were 54 ± 3 ppbv, 122 ± 7 ppbv and 213 ± 34 ngm-3 (mean ± expanded uncertainty with p < 95%), with clear seasonal cycles characterized by summer maxima and winter minima for O3 and BC and spring maximum and summer minimum for CO. According to FLEXPART output, BB impact is maximized during the warm months from July to September but appeared to have a significant contribution to the observed tracer concentrations only during specific transport events. We characterised in detail five major events with respect to transport scales (i.e. global, regional and local), source regions and O3, CO and BC variations. For these events, very large variability of enhancement ratios O3/CO (from -0.22 to 0.71) and BC/CO (from 2.69 to 29.83 ngm-3ppbv-1) were observed. CO related with anthropogenic emissions (COant) contributed to 17.4% of the mean CO value observed at ICO-OV, with the warm months appearing particularly affected by transport events of air-masses rich in anthropogenic pollution. The proportion of tracer variability that is described by FLEXPART COant peaked to 37% (in May-September) for CO, 19% (in May-September) for O3 and 32% (in January-April) for BC. During May-September, the analysis of the correlation among CO, O3 and BC as a function of the COant indicated that ICO-OV was influenced by air-masses rich in anthropogenic pollution transported from the regional to the global scale. On the other side, CO and O3 were negatively correlated during October-December, when FLEXPART does not show significant presence of recent anthropogenic emissions and only a few observations are characterized by enhanced BC. Such behaviour may be attributed to an ensemble of processes concurrent in enhancing O3 with low CO (upper troposphere/lower stratosphere intrusions) and O3 titration by NO in polluted air-masses along with lower photochemical activity. An intermediate situation occurs in January-April when CO and O3 were almost uncorrelated and BC enhancements were associated to relatively old (10 days) anthropogenic emissions. [ABSTRACT FROM AUTHOR]

Contents Somatic cell nuclear transfer (SCNT) was first developed in livestock for the purpose of accelerating the widespread use of superior genotypes. Although many problems still exist now after fifteen years of research owing to the limited understanding of genome reprogramming, SCNT has provided a powerful tool to make copies of selected individuals in different species, to study genome pluripotency and differentiation, opening new avenues of research in regenerative medicine and representing the main route for making transgenic livestock. Besides well-established methods to deliver transgenes, recent development in enzymatic engineering to edit the genome provides more precise and reproducible tools to target-specific genomic loci especially for producing knockout animals. The interest in generating transgenic livestock lies in the agricultural and biomedical areas and it is, in most cases, at the stage of research and development, with few exceptions that are making the way into practical applications. [ABSTRACT FROM AUTHOR]

This study presents two years of continuous observations of physical aerosol properties at the GAW-WMO global station "Nepal Climate Observatory -- Pyramid" (NCO-P, 27°57' N, 86° 48'E), sited at 5079 m a.s.l. in the high Himalayan Khumbu Valley (Nepal). Measurements of aerosol number size distribution, aerosol optical depth (AOD) and single scattering albedo (SSA) are analysed from March 2006 to February 2008. By studying the temporal variations of coarse (1 µm < Dp ≤10 µm) particle number concentration, 53 mineral Dust Transport Events (DTEs) are identified, accounting for 22.2% of the analysed data-set. Such events occurred prevalently during pre-monsoon (for 30.6% of the period) and winter (22.1%) seasons. However, uncommon cases of mineral dust transport are observed even during the monsoon season. The main sources of mineral dust reaching NCO-P are identified in the arid regions not far from the measurement site, i.e. from Tibetan Plateau, and Lot-Thar deserts, which account for 52% of the dust transport days. Moreover, a non-negligible contribution can be attributed to the Arabian Peninsula (17%) and the Indo-Gangetic Plains (16%), as indicated by three dimensional (3-D) back-trajectory analyses performed with LAGRANTO model. The observed DTEs lead to significant enhancements in the coarse aerosol number concentration (+513%) and coarse aerosol mass (+655%), as compared with average values observed in "dust-free" conditions (0.05 ± 0.11 cm-3 and 3.4 ± 3.7 µg m-3, respectively). During DTEs, SSA is higher (0.84-0.89) than on "dust-free" days (0.75-0.83), confirming the importance of this class of events as a driver of the radiative features of the regional Himalayan climate. Considering the dust events, a significant seasonal AOD increase (+37.5%) is observed in the post-monsoon, whereas lower increase (less than +11.1%) characterises the pre-monsoon and winter seasons confirming the influence of synoptic-scale mineral dust transports on the aerosol optical properties observed at NCO-P. [ABSTRACT FROM AUTHOR]

Aerosol mass and the absorbing fraction are important variables, needed to constrain the role of atmospheric particles in the Earth radiation budget, both directly and indirectly through CCN activation. In particular, their monitoring in remote areas and mountain sites is essential for determining source regions, elucidating the mechanisms of long range transport of anthropogenic pollutants, and validating regional and global models. Since March 2006, aerosol mass and black carbon concentration have been monitored at the Nepal Climate Observatory-Pyramid, a permanent high-altitude research station located in the Khumbu valley at 5079 m a.s.l. below Mt. Everest. The first twoyear averages of PM1 and PM1-10 mass were 1.94 μgm-3 and 1.88 μgm-3, with standard deviations of 3.90 μgm-3 and 4.45 μgm-3, respectively, while the black carbon concentration average is 160.5 ng m-3, with a standard deviation of 296.1 ng m-3. Both aerosol mass and black carbon show well defined annual cycles, with a maximum during the premonsoon season and a minimum during the monsoon. They also display a typical diurnal cycle during all the seasons, with the lowest particle concentration recorded during the night, and a considerable increase during the afternoon, revealing the major role played by thermal winds in influencing the behaviour of atmospheric compounds over the high Himalayas. The aerosol concentration is subject to high variability: in fact, as well as frequent "background conditions" (55% of the time) when BC concentrations are mainly below 100 ngm-3, concentrations up to 5 μgm-3 are reached during some episodes (a few days every year) in the premonsoon seasons. The variability of PM and BC is the result of both short-term changes due to thermal wind development in the valley, and long-range transport/synoptic circulation. At NCO-P, higher concentrations of PM1 and BC are mostly associated with regional circulation and westerly air masses from the Middle East, while the strongest contributions of mineral dust arrive from the Middle East and regional circulation, with a special contribution from North Africa and South-West Arabian Peninsula in post-monsoon and winter season. [ABSTRACT FROM AUTHOR]

This paper provides a detailed description of the atmospheric conditions characterizing the high Himalayas, thanks to continuous observations begun in March 2006 at the Nepal Climate Observatory-Pyramid (NCO-P) located at 5079ma.s.l. on the southern foothills of Mt. Everest, in the framework of ABC-UNEP and SHARE-Ev-K2-CNR projects. The work presents a characterization of meteorological conditions and air-mass circulation at NCO-P during the first two years of activity. The mean values of atmospheric pressure, temperature and wind speed recorded at the site were: 551 hPa, -3.0 °C, 4.7ms-1, respectively. The highest seasonal values of temperature (1.7 °C) and relative humidity (94%) were registered during the monsoon season, which was also characterized by thick clouds, present in about 80% of the afternoon hours, and by a frequency of cloud-free sky of less than 10%. The lowest temperature and relative humidity seasonal values were registered during winter, -6.3 °C and 22%, respectively, the season being characterised by mainly cloud-free sky conditions and rare thick clouds. The summer monsoon influenced rain precipitation (seasonal mean: 237 mm), while wind was dominated by flows from the bottom of the valley (S-SW) and upper mountain (N-NE). The atmospheric composition at NCO-P has been studied thanks to measurements of black carbon (BC), aerosol scattering coefficient, PM1, coarse particles and ozone. The annual behaviour of the measured parameters shows the highest seasonal values during the premonsoon (BC: 316.9 ngm-3, PM1: 3.9 μgm-3, scattering coefficient: 11.9Mm-1, coarse particles: 0.37 cm-3 and O3: 60.9 ppbv), while the lowest concentrations occurred during the monsoon (BC: 49.6 ngm-3, PM1: 0.6 μgm-3, scattering coefficient: 2.2Mm-1, and O3: 38.9 ppbv) and, for coarse particles, during the post-monsoon (0.07 cm-3). At NCO-P, the synoptic-scale circulation regimes present three principal contributions: Westerly, South-Westerly and Regional, as shown by the analysis of in-situ meteorological parameters and 5-day LAGRANTO back-trajectories. The influence of the brown cloud (AOD>0.4) extending over Indo-Gangetic Plains up to the Himalayan foothills has been evaluated by analysing the in-situ concentrations of the ABC constituents. This analysis revealed that brown cloud hot spots mainly influence the South Himalayas during the pre-monsoon, in the presence of very high levels of atmospheric compounds (BC: 1974.1 ngm-3, PM1: 23.5 μgm-3, scattering coefficient: 57.7Mm-1, coarse particles: 0.64 cm-3, O3: 69.2 ppbv, respectively). During this season 20% of the days were characterised by a strong brown cloud influence during the afternoon, leading to a 5-fold increased in the BC and PM1 values, in comparison with seasonal means. Our investigations provide clear evidence that, especially during the pre-monsoon, the southern side of the high Himalayan valleys represent a "direct channel" able to transport brown cloud pollutants up to 5000ma.s.l., where the pristine atmospheric composition can be strongly influenced. [ABSTRACT FROM AUTHOR]

The possible minimal range of reduction in snow surface albedo due to dry deposition of black carbon (BC) in the pre-monsoon period (March-May) was estimated as a lower bound together with the estimation of its accuracy, based on atmospheric observations at the Nepal Climate Observatory - Pyramid (NCO-P) sited at 5079ma.s.l. in the Himalayan region. A total BC deposition rate was estimated as 2.89 μgm-2 day-1 providing a total deposition of 266 μg m-2 for March-May at the site, based on a calculation with a minimal deposition velocity of 1.0×10-4 ms-1 with atmospheric data of equivalent BC concentration. Main BC size at NCO-P site was determined as 103.1-669.8 nm by correlation analyses between equivalent BC concentration and particulate size distributions in the atmosphere. The BC deposition from the size distribution data was also estimated. It was found that 8.7% of the estimated dry deposition corresponds to the estimated BC deposition from equivalent BC concentration data. If all the BC is deposited uniformly on the top 2-cm pure snow, the corresponding BC concentration is 26.0-68.2 μg kg-1, assuming snow density variations of 195-512 kgm-3 of Yala Glacier close to NCO-P site. Such a concentration of BC in snow could result in 2.0-5.2% albedo reductions. By assuming these albedo reductions continue throughout the year, and then applying simple numerical experiments with a glacier mass balance model, we estimated reductions would lead to runoff increases of 70-204mm of water. This runoff is the equivalent of 11.6-33.9% of the annual discharge of a typical Tibetan glacier. Our estimates of BC concentration in snow surface for pre-monsoon season is comparable to those at similar altitudes in the Himalayan region, where glaciers and perpetual snow regions begin, in the vicinity of NCO-P. Our estimates from only BC are likely to represent a lower bound for snow albedo reductions, because we used a fixed slower deposition velocity. In addition, we excluded the effects of atmospheric wind and turbulence, snow aging, dust deposition, and snow albedo feedbacks. This preliminary study represents the first investigation of BC deposition and related albedo on snow, using atmospheric aerosol data observed at the southern slope in the Himalayas. [ABSTRACT FROM AUTHOR]

We report chemical composition data for PM10 and PM1 from the Nepal Climate Observatory-Pyramid (NCO-P), the world's highest aerosol observatory, located at 5079m a.s.l. at the foothills of Mt. Everest. Despite its high altitude, the average PM10 mass apportioned by the chemical analyses is of the order of 6 μgm-3 (i.e., 10 μg/scm), with almost a half of this mass accounted for by organic matter, elemental carbon (EC) and inorganic ions, the rest being mineral dust. Organic matter, in particular, accounted for by 2.0 μgm-3 (i.e., 3.6 μg/scm) on a yearly basis, and it is by far the major PM10 component beside mineral oxides. Non-negligible concentrations of EC were also observed (0.36 μg/scm), confirming that light-absorbing aerosol produced from combustion sources can be efficiently transported up the altitudes of Himalayan glaciers. The concentrations of carbonaceous and ionic aerosols follow a common time trend with a maximum in the premonsoon season, a minimum during the monsoon and a slow recovery during the postmonsoon and dry seasons, which is the same phenomenology observed for other Nepalese Himalayan sites in previous studies. Such seasonal cycle can be explained by the seasonal variations of dry and moist convection and of wet scavenging processes characterizing the climate of north Indian subcontinent. We document the effect of orographic transport of carbonaceous and sulphate particles upslope the Himalayas, showing that the valley breeze circulation, which is almost permanently active during the out-of-monsoon season, greatly impacts the chemical composition of PM10 and PM1 in the high Himalayas and provides an efficient mechanism for bringing anthropogenic aerosols into the Asian upper troposphere (>5000m a.s.l.). The concentrations of mineral dust are impacted to a smaller extent by valley breezes and follow a unique seasonal cycle which suggest multiple source areas in central and south-west Asia. Our findings, based on two years of observations of the aerosol chemical composition, provide clear evidence that the southern side of the high Himalayas is impacted by transport of anthropogenic aerosols which constitute the Asian brown cloud. [ABSTRACT FROM AUTHOR]

The possible minimal range of reduction in snow surface albedo due to dry deposition of black carbon (BC) in the pre-monsoon period (March-May) was estimated as a lower bound together with the estimation of its accuracy, based on atmospheric observations at the Nepal Climate Observatory-Pyramid (NCO-P) sited at 5079 m a.s.l. in the Himalayan region. We estimated a total BC deposition rate of 2.89 μg m-2 day-1 providing a total deposition of 266 μg m-2 for March-May at the site, based on a calculation with a minimal deposition velocity of 1.0×10-4 m s-1 with atmospheric data of equivalent BC concentration. Main BC size at NCO-P site was determined as 103.1-669.8 nm by correlation analysis between equivalent BC concentration and particulate size distribution in the atmosphere. We also estimated BC deposition from the size distribution data and found that 8.7% of the estimated dry deposition corresponds to the estimated BC deposition from equivalent BC concentration data. If all the BC is deposited uniformly on the top 2-cm pure snow, the corresponding BC concentration is 26.0-68.2 μg kg-1 assuming snow density variations of 195-512 kg m-3 of Yala Glacier close to NCO-P site. Such a concentration of BC in snow could result in 2.0-5.2% albedo reductions. From a simple numerical calculations and if assuming these albedo reductions continue throughout the year, this would lead to a runoff increases of 70-204 mm of water drainage equivalent of 11.6-33.9% of the annual discharge of a typical Tibetan glacier. Our estimates of BC concentration in snow surface for pre-monsoon season can be considered comparable to those at similar altitude in the Himalayan region, where glaciers and perpetual snow region starts in the vicinity of NCO-P. Our estimates from only BC are likely to represent a lower bound for snow albedo reductions, since a fixed slower deposition velocity was used and atmospheric wind and turbulence effects, snow aging, dust deposition, and snow albedo feedbacks were not considered. This study represents the first investigation about BC deposition on snow from atmospheric aerosol data in Himalayas and related albedo effect is especially the first track at the southern slope of Himalayas. [ABSTRACT FROM AUTHOR]

Aerosol mass and the absorbing fraction are important variables, needed to constrain the role of atmospheric particles in the Earth radiation budget, both directly and indirectly through CCN activation. In particular, their monitoring in remote areas and mountain sites is essential for determining source regions, elucidating the mechanisms of long range transport of anthropogenic pollutants, and validating regional and global models. Since March 2006, aerosol mass and black carbon concentration have been monitored at the Nepal Climate Observatory-Pyramid, a permanent high-altitude research station located in the Khumbu valley at 5079ma.s.l. below Mt. Everest. The first 10 two-year averages of PM1 and PM1-10 mass were 1.94 μgm-3 and 1.88 μgm-3, with standard deviations of 3.90 μgm-3 and 4.45 μgm-3, respectively, while the black carbon concentration average is 160.5 ngm-3, with a standard deviation of 296.1 ngm-3. Both aerosol mass and black carbon show well defined annual cycles, with a maximum during the pre-monsoon season and a minimum during the monsoon. They also display a typical diurnal cycle during all the seasons, with the lowest particle concentration recorded during the night, and a considerable increase during the afternoon, revealing the major role played by thermal winds in influencing the behaviour of atmospheric compounds over the high Himalayas. The aerosol concentration is subject to high variability: in fact, as well as frequent "background conditions" (55% of the time) when BC concentrations are mainly below 100 ngm-3, concentrations up to 5 μgm-3 are reached during some episodes (a few days every year) in the pre-monsoon seasons. The variability of PM and BC is the result of both short-term changes due to thermal wind development in the valley, and long-range transport/synoptic circulation. At NCO-P, higher concentrations of PM1 and BC are mostly associated with regional circulation and westerly air masses from the Middle East, while the strongest contributions of mineral dust arrive from the Middle East and regional circulation, with a special contribution from North Africa and South-West Arabian Peninsula in post-monsoon and winter season. [ABSTRACT FROM AUTHOR]

South Asia is strongly influenced by the so-called Atmospheric Brown Cloud (ABC), a wide polluted layer extending from the Indian Ocean to the Himalayas during the winter and pre-monsoon seasons (November to April). This thick, grey-brown haze blanket substantially interacts with the incoming solar radiation, causing a cooling of the Earth's surface and a warming of the atmosphere, thus influencing the monsoon system and climate. In this area, the Himalayan region, particularly sensitive to climate change, offers a unique opportunity to detect global change processes and to analyse the influence of anthropogenic pollution on background atmospheric conditions through continuous monitoring activities. This paper provides a detailed description of the atmospheric conditions characterizing the high Himalayas, thanks to continuous observations begun in March 2006 at the Nepal Climate Observatory - Pyramid (NCO-P) located at 5079m a.s.l. on the southern foothills of Mt. Everest, in the framework of ABC-UNEP and SHARE-Ev-K2-CNR projects. Besides giving an overview of the measurement site and experimental activities, the work presents an in-depth characterization of meteorological conditions and air-mass circulation at NCO-P during the first two years of activity (March 2006-February 2008). The mean values of atmospheric pressure, temperature and wind speed recorded at the site were: 551 hPa, -3.0 °C, 4.7ms-1, respectively. The highest seasonal values of temperature (1.7 °C) and relative humidity (94%) were registered during the monsoon season, which was also characterized by thick clouds present in about 80% of the afternoon hours and by a frequency of cloud-free sky less than 10%. The lowest temperature and relative humidity values were registered during winter, -6.3 °C and 22%, respectively, the season being characterised by mainly cloud-free sky conditions and rare thick clouds. The summer monsoon influenced the rain precipitation (seasonal mean 237 mm), while wind was dominated by flows from the bottom of the valley (S-SW) and upper mountain (N-NE). In relation to seasonal weather conditions, the time series variability of black carbon and dust particles (optical active aerosols) and ozone (regional greenhouse gas) were analysed, as they are significant constituents of the Atmospheric Brown Cloud and strongly influence the atmospheric radiative forcing. The highest seasonal values of black carbon (BC), ozone (O3) and dust particles were observed during the pre-monsoon season (316.9 ngm-3, 60.9 ppbv, 0.37 cm-3, respectively), while the lowest concentrations occurred during the monsoon for BC and O3 (49.6 ngm-3 and 33.6 ppbv, respectively) and postmonsoon for dust particles (0.07 cm-3). The seasonal cycles of these compounds are influenced both by the local mountain wind system and by the three principal largescale circulation regimes: Westerly, South-Westerly and Regional, as shown by the analysis of in-situ meteorological parameters and 5-day LAGRANTO back-trajectories.… [ABSTRACT FROM AUTHOR]

The paper presents the first 2-years of continuous surface ozone (O3 ) observations and systematic assessment of the influence of stratospheric intrusions (SI) at the Nepal Climate Observatory at Pyramid (NCO-P; 27°57′ N, 86°48′ E), located in the Southern 5 Himalayas at 5079ma.s.l. Continuous O3 monitoring has been carried out at this GAW-WMO station in the framework of the Ev-K2-CNR SHARE and UNEP ABC projects since March 2006. Over the period March 2006-February 2008, an average O3 value of 49±12 ppbv (±1δ) was recorded, with a large annual cycle characterized by a maximum during the pre-monsoon (61±9 ppbv) and a minimum during the mon10 soon (39±10 ppbv). In general, the average O3 diurnal cycles had different shapes in the different seasons, suggesting an important interaction between the synoptic-scale circulation and the local mountain wind regime. Short-term O3 behaviour in the middle/lower troposphere (e.g. at the altitude level of NCO-P) can be significantly affected by deep SI which, representing the most important 15 natural input for tropospheric O3 , can also influence the regional atmosphere radiative forcing. To identify days possibly influenced by SI at the NCO-P, analyses were performed on in-situ observations (O3 and meteorological parameters), total column O3 data from OMI satellite and air-mass potential vorticity provided by the LAGRANTO back-trajectory model. In particular, a specially designed statistical methodology was 20 applied to the time series of the observed and modelled stratospheric tracers. On this basis, during the 2-year investigation, 14.1% of analysed days were found to be affected by SI. The SI frequency showed a clear seasonal cycle, with minimum during the summer monsoon (1.2%) and higher values during the rest of the year (21.5%). As suggested by the LAGRANTO analysis, the position of the subtropical jet stream 25 could play an important role in determining the occurrence of deep SI transport on the Southern Himalayas. In order to estimate the fraction of O3 due to air-mass transport from the stratosphere at the NCO-P, the 30 min O3 concentrations recorded during the detected SI days were analysed. In particular, in-situ relative humidity and black carbon observations were used to exclude influence from wet and polluted air-masses transported by up-valley breezes. This analysis led to the conclusion that during SI O3 significantly increased by 27.1% (+13 ppbv) with respect to periods not affected by such events. Moreover, the integral contribution 5 of SI (O3 S) to O3 at the NCO-P was also calculated, showing that 13.7% of O3 recorded at the measurement site could be attributed to SI. On a seasonal basis, the lowest SI contributions were found during the summer monsoon (less than 0.1%), while the highest were found during the winter period (24.2%). These results indicated that, during non-monsoon periods, high O3 levels could affect NCO-P during 10 SI, thus influencing the variability of tropospheric O3 over the Southern Himalayas. Being a powerful regional greenhouse gas, these results indicate that the evaluation of the current and future regional climate cannot be assessed without properly taking into account the influence of SI to tropospheric O3 in this important area. [ABSTRACT FROM AUTHOR]

We report chemical composition data for PM10 and PM1 from the Nepal Climate Observatory-Pyramid (NCO-P), the world's highest aerosol observatory, located at 5079 m a.s.l. at the foothills of Mt. Everest. Despite its high altitude, the average PM10 mass apportioned by the chemical analyses is of the order of 6 μgm-3 (i.e., 10 μg/scm), with almost a half of this mass accounted for by organic matter, elemental carbon (EC) and inorganic ions, the rest being mineral dust. Organic matter, in particular, accounted for by 2.0 μgm-3 (i.e., 3.6 μg/scm) on a yearly basis, and it is by far the major PM10 component beside mineral oxides. Non-negligible concentrations of EC were also observed (0.36 μg/scm), confirming that optically-active aerosol produced from combustion sources can be efficiently transported up the altitudes of Himalayan glaciers. The concentrations of carbonaceous and ionic aerosols follow a common time trend with a maximum in the premonsoon season, a minimum during the monsoon and a slow "ramp-up" period in the postmonsoon and dry seasons, which is the same phenomenology observed for other Nepalese Himalayan sites in previous studies. Such seasonal cycle can be explained by the seasonal variations of dry and moist convection and of wet scavenging processes characterizing the climate of north Indian subcontinent. We document the effect of orographic transport of carbonaceous and sulphate particles upslope the Himalayas, showing that the valley breeze circulation, which is almost permanently active during the out-of-monsoon season, greatly impacts the chemical composition of PM10 and PM1 in the high Himalayas and provides an efficient mechanism for bringing anthropogenic optically-active aerosols into the Asian upper troposphere (>5000 m a.s.l.). The concentrations of mineral dust are impacted to a smaller extent by valley breezes and follow a unique seasonal cycle which suggest multiple source areas in central and south-west Asia. Our findings, based on two years of observations of the aerosol chemical composition, provide clear evidence that the southern side of the high Himalayas are impacted by transport of anthropogenic aerosols which constitute the Asian brown cloud. [ABSTRACT FROM AUTHOR]

In this work, we present the first systematic identification of episodes of air mass transport from the lower stratosphere/upper troposphere (LS/UT) in the middle troposphere of the southern Himalayas. For this purpose, we developed an algorithm to detect LS/UT transport events on a daily basis at the Everest-Pyramid GAW station (EV-PYR, 5079 m a.s.l., Nepal). In particular, in situ surface ozone and atmospheric pressure variations as well as total ozone values from OMI satellite measurements have been analysed. Further insight is gained from three-dimensional backward trajectories and potential vorticity calculated with the LAGRANTO model. According to the algorithm outputs, 9.0% of the considered data set (365 days from March 2006 to February 2007) was influenced by this class of phenomena with a maximum of frequency during dry and pre-monsoon seasons. During 25 days of LS/UT transport events for which any influence of anthropogenic pollution was excluded, the daily ozone mixing ratio increased by 9.3% compared to the seasonal values. This indicates that under favourable conditions, downward air mass transport from the LS/UT can play a considerable role in determining the concentrations of surface ozone in the southern Himalayas. [ABSTRACT FROM AUTHOR]

This work introduces an index to identify deep stratospheric intrusions (SI) from measurement data alone, without requiring additional model-based information. This stratospheric intrusion index (SI2) provides a qualitative description of SI event behaviour by summarizing the information from different tracer variations. Moreover, being independent from any model constraint, the SI2 can also represent a valid tool to help in evaluating the capacity of chemistry-transport and chemistry-climate models in simulating deep stratosphere to troposphere transport. The in situ variations of ozone, beryllium-7 and relative humidity were used to calculate the index. The SI2 was applied on 8-year data recorded at the regional GAW station of Mt. Cimone (2165 m asl; 44.10N, 10.70E: Italy). The comparison of the SI2 behaviour with a pre-existing database obtained by also using model products, permitted us to tune a SI2-threshold value capable of identifying SI events efficiently. In good agreement with previous climatological studies across Europe, at Mt. Cimone, the averaged monthly SI frequency obtained by the SI2 analysis showed a clear seasonal cycle with a winter maximum and a spring-summer minimum. These results suggest that the presented methodology is efficient for both identifying SI events and evaluating their annual frequency at the considered baseline measurement site. [ABSTRACT FROM AUTHOR]

High levels of trace gas (O3 and CO) and aerosol (BC, fine and coarse particle volumes), as well as high scattering coefficient (σp) values, were recorded at the regional GAW-WMO station of Mt. Cimone (CMN, 2165 m a.s.l., Italy) during the period 26-30 August 2007. Analysis of air-mass circulation, aerosol chemical characterization and trace gas and aerosol enhancement ratios (ERs), showed that high O3 and aerosol levels were likely linked to (i) the transport of anthropogenic pollution from northern Italy, and (ii) the advection of air masses rich in mineral dust and biomass burning (BB) products from North Africa. In particular, during the advection of air masses from North Africa, the CO and aerosol levels (CO: 175 ppbv, BC: 1015 ng/m³, fine particle volume: 3.00μm³ cm-3, σp: 84.5 Mm-1) were even higher than during the pollution event (CO: 138 ppbv, BC: 733 ng/m³, fine particles volume: 1.58 μm³ cm-3, σp: 44.9 Mm-1). Moreover, despite the presence of mineral dust able to affect significantly the O3 concentration, the analysis of ERs showed that the BB event represented an efficient source of fine aerosol particles (e.g. BC), but also of the O3 recorded at CMN. In particular, the calculated O3/CO ERs (0.10-0.17 ppbv/ppbv) were in the range of values found in literature for relatively aged (2-4 days) BB plumes and suggested significant photochemical O3 production during the air-mass transport. For fine particles and σp, the calculated ERs was higher in the BB plumes than during the anthropogenic pollution events, stressing the importance of the identified BB event as a source of atmospheric aerosol able to affect the atmospheric radiation budget. These results suggest that episodes of mineral dust mobilization and wildfire emissions over North Africa could significantly influence radiative properties (as deduced from σp observations at CMN) and air quality over the Mediterranean basin and northern Italy. [ABSTRACT FROM AUTHOR]

Embryo technologies are a combination of assisted reproduction, cellular and molecular biology and genomic techniques. Their classical use in animal breeding has been to increase the number of superior genotypes but with advancement in biotechnology and genomics they have become a tool for transgenesis and genotyping. Multiple ovulation and embryo transfer (MOET) has been well established for many years and still accounts for the majority of the embryos produced worldwide. However, no progress has been made in the last 20 years to increase the number of transferable embryos and to reduce the side effects on the reproductive performance of the donors. In vitro embryo production (IVP) is a newer and more flexible approach, although it is technically more demanding and requires specific laboratory expertise and equipment that are most important for the quality of the embryos produced. Somatic cell cloning is a rapidly developing area and a very valuable technique to copy superior genotypes and to produce or copy transgenic animals. More knowledge in oocyte and embryo biology is expected to shed new light on the early developmental events, including epigenetic changes and their long lasting effect on the newborn.Embryo technologies are here to stay and their use will increase as advances in the understanding of the mechanisms governing basic biological processes are made. [Copyright &y& Elsevier]

In the buffalo, the use of embryo-based biotechnologies for breeding and genetic improvement is still very limited because multiple-ovulation embryo transfer delivers poor results compared with cattle and in vitro embryo production has been used mainly for research purposes. At present, very few reports are available on the transfer of in vitro-produced (IVP) and cryopreserved buffalo embryos. Therefore, the scope of this work was to perform a pilot study to evaluate the viability of frozen-thawed IVP embryos by nonsurgical embryo transfer to recipients in an IVF-embryo transfer program on a farm located on the north coast of Colombia, South America. Buffalo oocytes were recovered at the slaughterhouse from selected donors, matured in vitro for 18 to 20 h in TCM-199 + 10% FCS and 0.5 IU of FSH and 0.5 IU of LH in 5% CO2 at 38.5°C. Four different bulls were used for IVF. After thawing, the semen was separated on a Percoll® gradient and then diluted into SOF-IVF media supplemented with 1 μg mL-1 of heparin and phenylalanine. Presumptive zygotes were cultured in modified SOF supplemented with MEM amino acids for 6 days. Half of the medium was replaced on Day 4 and 6. Developing embryos were selected for freezing on Day 6 and 7. Grade 1 embryos were frozen at the blastocyst stage by slow cooling in 10% glycerol or 1.5 M ethylene glycol. Recipients (heifers n = 79 and uniparous cows n = 17) were synchronized using the CIDR-Synch protocol: on Day 0, gonadotropin-releasing hormone was injected and a CIDR was inserted; on Day 7, prostaglandin F2α was administered; on Day 9, the CIDR was removed; on Day 11, a second injection of gonadotropin-releasing hormone was given; and on Day 17, the embryo was transferred. Each female received, nonsurgically, 1 or 2 embryos in the ipsilateral horn to the functional corpus luteum evaluated by ultrasonography. Pregnancies were evaluated by ultrasonography 30 days after transfer and confirmed by rectal palpation 30 days later. This work was performed in 2 successive experiments during the breeding seasons (January and December, respectively). Overall, 96 recipients were transferred, with 136 embryos obtaining 23 pregnancies (24.2%). There were no statistical differences in pregnancy rate between heifers and cows (25.3 vs 17.7%) and between single (n = 56) and double (n = 39) embryo transfers (21.4 vs 27.5%) by chi square test (P > 0.05). To date, 4 females and 5 males have been born by spontaneous calving (1 stillborn male due to dystocia), 3 pregnancies have been aborted (13%) and 11 pregnancies are ongoing (>7 months). The pregnancy rate obtained in this study in farm conditions (24.2%) is lower than generally obtained with frozen IVP cattle embryos, but it is still a good result in buffalo, where even conventional AI provides a lower success rate as compared with cattle. Finally, this work demonstrates that in vitro embryo production can be successfully implemented in buffalo breeding programs for the exploitation of superior genetics. This work was supported by Regione Lombardia, Por Fers 2007-2013, n°13827741, InnovaB. [ABSTRACT FROM AUTHOR]

The genetic engineering of the pig genome for xenotransplantation studies requires the insertion of different transgenes to create multi-transgenic pigs. In order to simultaneously add more transgene in a single genetic insertion, we constructed a polycistronic vector using the F2A self-cleaving peptide. Moreover, this solution has the added advantages of preventing possible segregation during breeding of the animals and of guaranteeing an equimolar production of chosen transgenes. The scope of this work was the construction and validation of an ubiquitous F2A-bicistronic expression vector for human thrombomodulin (hTM) and human endothelial protein C receptor (hEPCR) genes in pig primary hCD55-GAL-/- cells to establish transgenic fibroblasts colonies, to be used for somatic cell nuclear transfer (SCNT) to generate pigs for xenotransplantation research. The expression vector consisted of pCAGGS promoter (CMV-IE+chicken β actin) followed by hEPCR-furinF2A-hTM coding sequence. The resulting expression cassette was inserted between 2 insulators obtained from the 5′ MAR region of chicken lysozyme. Outside of this insulated structure, there is a loxable puromycin selection cassette. The resulting purified and linearized expression vector (pEFTM/Lgu I = 5 μg) was transfected into hCD55-GAL-/- primary fibroblasts (1 × 106), using Nucleofector (Amaxa, Lonza, Cologne, Germany), in parallel for comparative purposes we cotransfected the 2 pCAGGS-monocistronic vectors for the same transgenes (hEPCR and hTM = 1:3, 5 μg). Transfected cells were selected with puromycin (1 μg mL-1) for 15 days. After 8 days of selection, resistant colonies were picked up and expanded into 24-well plates for cryopreservation and analyses. Bicistronic transfection produced 20 clones and cotransfection only 8 clones that were analysed by Western blot (WB) and by immunocytochemistry (ICC) using polyclonal antibody anti-EPCR (1:250, R&D) and monoclonal antibody ab6980-Abcam (1:5000, Abcam, Cambridge, UK) in WB; polyclonal antibody RCR252 (1:100, Sigma-Aldrich, St. Louis, MO, USA) and monoclonal antibody ab6980-Abcam (1:100, Abcam) for ICC. Seventeen bicistronic clones (85%) and 2 cotransfected monocistronic clones (25%) were positive for both transgenes using WB. After ICC analyses, only 11 bicistronic colonies (55%) and 1 cotransfected colony (12.5%) uniformly expressed the desired transgenes and were selected for SCNT. The pCAGGS promoter maintained its strong expression also using the hEPCR-FurinF2A-hTM coding sequence and this bicistronic solution permitted us to improve our results obtained with co-transfection. Availability of hEPCR+ hTM+ hCD55+-GAL-/- colonies will allow us to obtain a new transgenic background for future xenotransplantation projects. This study was supported by EU grant no. LSHB-CT-2006-037377 (Xenome) and by Regione Lombardia (Superpig project). [ABSTRACT FROM AUTHOR]

Both preimplantation and full-term development of mouse somatic cell nuclear transfer (SCNT) embryos are significantly enhanced by treatment with trichostatin A (TSA), an inhibitor of histone deacetylase (Kishigami et al.2006 Biochem. Biophys. Res. Commun. 340, 183–189; Rybouchkin et al.2006 Biol. Reprod. 74, 1083–1089). The present study was designed to examine the effect of TSA treatment on preimplantation and full-term development of bovine cloned embryos. To investigate the effect of TSA on bovine NT embryos development, we treated them with 50nM TSA during the first 10h after activation. Bovine NT-embryos were reconstructed using adult fibroblasts of 2 female donors (A and B) with significantly different in vitrocloning efficiency (respectively, 84/245; 34.3% v.155/298; 52.1% blastocyst D7, P≤0.05, chi-square test). TSA treatment significantly improved blastocyst rate in A, however did not affect development in B (56.3% and 50.5%, respectively). The level of acetylated histone H3K9 10h after activation detected by anti-acH3K9 antibody was significantly increased after TSA-treatment in A (P≤0.05, Student’s t-test) but did not change in B, thus demonstrating that the levels of histone acetylation in cloned embryos correlate with their in vitrodevelopmental potential. To evaluate the long-lasting effect of TSA-treatment on the full-term development of cloned embryos, SCNT embryos derived from 4 female donor animals were reconstructed. 196 TSA-treated embryos at the blastocyst stage were transferred into 98 recipients and 2 calves (2%) were born. In the control group, 167 embryos were transferred into 141 recipients and 3 calves (2.1%) were born. Our data show that cell lines demonstrate different susceptibility to TSA that may affect reprogramming of the somatic genome with low level of acetylation resulting in higher in vitroembryo development. However, TSA does not improve overall cloning efficiency in cattle, measured as full-term development. Project partly supported by EU grants Plurisys (n 22348), Xenome (LSHB-CT-2006-037377) and Regione Lombardia. [ABSTRACT FROM AUTHOR]

The introduction in equine reproduction of ovum pickup (OPU) combined with intracytoplasmic sperm injection (ICSI), IVC, and embryo transfer, has allowed for the production of offspring from donors and stallions that could not reproduce by conventional techniques. For this reason, we used in our OPU-ICSI-IVC program both fertile stallions and stallions with field records of low or no fertility. Overall, 805 and 584 OPU oocytes were fertilized with sperm from fertile and infertile stallions, respectively. Cleavage rate was statistically lower in the latter group (65.94 v.59.24%, chi square test; P< 0.05) but embryo development was similar (11.67 v.8.20% blastocysts/injected oocytes, chi-square test). In order to further investigate the stallion effect on embryo development, we selected 3 stallions with low (A) or no (B, C) fertility in the field and we compared the results of the OPU program with embryo development obtained using oocytes recovered from abattoir ovaries and matured, fertilized, and cultured in vitroas the OPU oocytes. Part of the abattoir oocytes was fertilized with a stallion with known high fertility both in vivoand in vitro(abattoir fertile). Overall, the results (shown in the table) suggest a reduction in the efficiency of stallions A, B, and C compared with to the fertile stallion used as control (10.79, 7.69, and 5.0% v.17.35%, respectively). For stallions A and B, the efficiency was further reduced in the OPU setting, indicating that the female component can play a role in the overall efficiency of the procedure. In particular, 4 mares out of 8 had a history of no pregnancy and all mares had some rate of inbreeding with the respective stallion used for the ICSI. Instead, the oocytes from the abattoir ovaries were collected in large pools from several mares, representing an average oocyte quality, and the mares were of different breed than the stallions. All data were analyzed by chi-square test and significance was set at P< 0.05. In conclusion, we demonstrated that, for those stallions in which fertility in the field is low or absent, OPU-ICSI-IVP is a suitable choice to obtain embryos, although the efficiency is variable depending not only on the stallion but also on the origin of the oocytes. Table 1.Stallion effect on embryo development of ovum pickup (OPU) and abattoir oocytesThis work was supported by Fondazione Cariplo and Regione Lombardia. [ABSTRACT FROM AUTHOR]

Abstract: Development of assisted reproductive technologies in horses has been relatively slow compared to other domestic species, namely ruminants and pigs. The scarce availability of abattoir ovaries and the lack of interest from horse breeders and breed associations have been the main reasons for this delay. Progressively though, the technology of oocyte maturation in vitro has been established followed by the application of ICSI to achieve fertilization in vitro. Embryo culture was initially performed in vivo, in the mare oviduct or in the surrogate sheep oviduct, to achieve the highest embryo development, in the range of 18–36% of the fertilised oocytes. Subsequently, the parallel improvement of in vitro oocyte maturation conditions and embryo culture media has permitted high rates of embryo development from in vitro matured and in vitro cultured ICSI embryos, ranging from 5 to 10% in the early studies to up to 38% in the latest ones. From 2003, with the birth of the first cloned equids, the technology of somatic cell nuclear transfer has also become established due to improvement of the basic steps of embryo production in vitro, including cryopreservation. Pregnancy and foaling rates are still estimated based on a small number of in vitro produced equine embryos transferred to recipients. The largest set of data on non-surgical embryo transfer of in vitro produced embryos, from ICSI of both abattoir and in vitro-matured Ovum Pick Up (OPU) oocytes, and from somatic cell nuclear transfer, has been obtained in our laboratory. The data demonstrate that equine embryos produced by OPU and then cryopreserved can achieve up to 69% pregnancy rate with a foaling rate of 83%. These percentages are reduced to 11 and 23%, respectively, for cloned embryos. In conclusion, extensive evidence exists that in vitro matured equine oocytes can efficiently develop into viable embryos and offspring. [Copyright &y& Elsevier]

Leigh syndrome (LS) associated with cytochrome c oxidase (COX) deficiency is an early onset, fatal mitochondrial encephalopathy, leading to multiple neurological failure and eventually death, usually in the first decade of life. Mutations in SURF1 , a nuclear gene encoding a mitochondrial protein involved in COX assembly, are among the most common causes of LS. LS SURF1 patients display severe, isolated COX deficiency in all tissues, including cultured fibroblasts and skeletal muscle. Recombinant, constitutive SURF1 −/− mice show diffuse COX deficiency, but fail to recapitulate the severity of the human clinical phenotype. Pigs are an attractive alternative model for human diseases, because of their size, as well as metabolic, physiological and genetic similarity to humans. Here, we determined the complete sequence of the swine SURF1 gene, disrupted it in pig primary fibroblast cell lines using both TALENs and CRISPR/Cas9 genome editing systems, before finally generating SURF1 − / − and SURF1 −/+ pigs by Somatic Cell Nuclear Transfer (SCNT). SURF1 −/− pigs were characterized by failure to thrive, muscle weakness and highly reduced life span with elevated perinatal mortality, compared to heterozygous SURF1 −/+ and wild type littermates. Surprisingly, no obvious COX deficiency was detected in SURF1 −/− tissues, although histochemical analysis revealed the presence of COX deficiency in jejunum villi and total mRNA sequencing (RNAseq) showed that several COX subunit-encoding genes were significantly down-regulated in SURF1 −/− skeletal muscles. In addition, neuropathological findings, indicated a delay in central nervous system development of newborn SURF1 −/− piglets. Our results suggest a broader role of sSURF1 in mitochondrial bioenergetics. [ABSTRACT FROM AUTHOR]

To study the influence of polluted air-mass transport carrying ozone (O 3 ) and black carbon (BC) in the high Himalayas, since March 2006 the Nepal Climate Observatory at Pyramid (NCO-P) GAW-WMO global station (Nepal, 5079 m a.s.l.) is operative. During the first 5-year measurements, the O 3 and BC concentrations have shown a mean value of 48 ± 12 ppb (± standard deviation) and 208 ± 374 ng/m 3 , respectively. Both O 3 and BC showed well defined seasonal cycles with maxima during pre-monsoon (O 3 : 61.3 ± 7.7 ppbV; BC: 444 ± 433 ng/m 3 ) and minima during the summer monsoon (O 3 : 40.1 ± 12.4 ppbV; BC: 64 ± 101 ng/m 3 ). The analysis of the days characterised by the presence of a significant BC increase with respect to the typical seasonal cycle identified 156 days affected by “acute” pollution events, corresponding to 9.1% of the entire data-set. Such events mostly occur in the pre-monsoon period, when the O 3 diurnal variability is strongly related to the transport of polluted air-mass rich on BC. On average, these “acute” pollution events were characterised by dramatic increases of BC (352%) and O 3 (29%) levels compared with the remaining days. [ABSTRACT FROM AUTHOR]

Abstract: In the frame of the MIUR-AEROCLOUDS project (Study of Direct and Indirect Aerosol Effects on Climate), night-time and daytime size-segregated aerosol samples were collected concurrently at five different sites (near-city, urban, rural, marine and mountain background sites). The paper reports on the daily evolution of the main aerosol chemical characteristics as a function of particle size in different environments over the Italian Peninsula, spanning from the Po Valley to the south Tyrrhenian coast. Two 4-day intensive observation periods (IOPs) were undertaken in July 2007 and February 2008, under meteorological conditions typical of the summer and winter climate for Italy. In the summer IOP, under stable atmospheric conditions, at the low-altitude continental sites the diurnal evolution of the planetary boundary layer (PBL), induces an atmospheric dilution effect driving the particulate matter (PM) concentrations, while, at the mountain site, it determines the upward motion of polluted air masses from the Po Valley PBL in daytime. The fine fraction was dominated by ammonium salts and carbonaceous matter (water-soluble organic matter, WSOM, and water-insoluble carbonaceous matter, WINCM). High concentrations of ammonium sulphate and WSOM due to enhanced photochemical activity constituted the background aerosol composition over the whole country, whereas, ammonium nitrate and WINCM were more associated to local emissions (e.g. urban site with concentrations peaking in the finest size range due to strong local traffic-related sources of ultrafine particles). During the winter IOP in the Po Valley, the shallow PBL depths and low wind velocity, especially at night, favoured the condensation of semi-volatile species (i.e. organic matter and ammonium nitrate), causing the high fine PM concentration observed at ground level. [ABSTRACT FROM AUTHOR]