Mediterranean Island Of Lampedusa Research Articles

Of Other Spaces (of Memory)

Contemporary border regimes are confronting us with a double question: Can one give an account of oneself and narrate one’s story, even if things are taking place do not make stories possible in language? Can we possibly think of a politics of memory that is neither bound to given places nor to language, but that rather displaces conventional realms of memory? In the context of this double question, my paper is going to trace a few thoughts on a transitional space of memory that has recently emerged on the Mediterranean island of Lampedusa.

Tropospheric halocompounds and nitrous oxide monitored at a remote site in the Mediterranean

Analysis of time series and trends of nitrous oxide (N 2O) and halocompounds weekly monitored at the Mediterranean island of Lampedusa are discussed. Atmospheric N 2O levels showed a linear upward growth rate of 0.78 ppb yr −1 and mixing ratios comparable with Northern Hemisphere global stations. CFC-11 and CFC-12 time series displayed a decline consistent with their phase-out. Chlorofluorocarbons (CFCs) replacing compounds and SF 6 exhibited an increasing temporal behaviour. The most rapid growth rate was recorded for HFC-134a with a value of 9.6% yr −1. The industrial solvents CCl 4 and CH 3CCl 3, banned by the Montreal Protocol, showed opposite trends. While CH 3CCl 3 reported an expected decay of −1.8 ppt yr −1, an increasing rate of 5.7 ppt yr −1 was recorded for CCl 4 and it is probably related to its relatively long lifetime and persisting emissions. Chlorinated halomethanes showed seasonality with a maximum in early April and a minimum at the end of September. Halon-1301 and Halon-1211 displayed a decreasing trend consistent with industry emission estimates. An interspecies correlation analysis gave positive high correlations between HCFC-22 and HFC-134a (+0.84) highlighting the common extensive employment as refrigerants. Sharing sources inferred the high coupling between CH 3Cl and CH 3Br (+0.73) and between CHCl 3 and CH 2Cl 2 (+0.77). A singular strong relationship (+0.55) between HFC-134a and CH 3I suggested the influence of an unknown anthropogenic source of CH 3I. Constraining of source and sink distribution was carried out by transport studies. Results were compared with the European Environment Agency (EEA) emission database. In contrast with the emission database results, our back trajectory analysis highlighted the release of large amounts of HFC-134a and SF 6 from Eastern Europe. Observations also showed that African SF 6 emissions may be considerable. Leakages from SF 6 insulated electrical equipments located in the industrialized Northern African areas justify our observations.

Measurements of Mediterranean aerosol radiative forcing and influence of the single scattering albedo

Ground‐based measurements of aerosol optical depth and surface shortwave irradiance carried out at the Mediterranean island of Lampedusa during 2004–2007 are used to estimate the surface aerosol direct radiative forcing for desert dust (DD), urban/industrial‐biomass burning (UI‐BB), and mixed aerosols (MA). The aerosol single scattering albedo, ω, at 415.6 and 868.7 nm is derived at 60° solar zenith angle, θ, from measurements of global and diffuse radiation using radiative transfer model calculations. The shortwave forcing efficiency (FES) is derived, for θ between 20° and 75°, for the three identified classes of aerosol and for all the observed data (AD). The absolute value of FES decreases for increasing θ for all the aerosol types. FES varies between −185 and −81.7 W m−2 for DD, −168 and −84 W m−2 for UI‐BB, −251 and −120.2 W m−2 for MA, and −208 and −106.5 W m−2 for AD. The daily average forcing efficiency (FEd) at the equinox is −67.2 W m−2 for DD, −59.0 W m−2 for UI‐BB, and −93.2 W m−2 for MA. The forcing efficiency of DD, UI‐BB, and MA at θ = 60° was calculated for three intervals of single scattering albedo (0.7 ≤ ω < 0.8, 0.8 ≤ ω < 0.9, 0.9 ≤ ω ≤ 1) at 415.6 and 868.7 nm. The absolute value of FES decreases with increasing ω at 868.7 nm for all aerosol types, while it decreases with increasing ω at 415.6 nm for UI‐BB and MA and increases for DD. A 0.1 increment in the single scattering albedo at 868.7 nm produces a reduction in FES by 25–30 W m−2, and a reduction by 10–15 W m−2 in FEd.

Megaribavirin Aerosol for the Treatment of Influenza A Virus Infections in Mice

Saharan dust (SD) episodes occurring at the Mediterranean island of Lampedusa (35.52° N, 12.63° E) from May 1999 to December 2005 have been shown to occur in the 26% of the cloud-free days [Meloni, D., di Sarra, A., Biavati, G., DeLuisi, J.J., Monteleone, F., Pace, G., Piacentino, S., Sferlazzo, D.M., 2007. Seasonal behavior of Saharan dust events at the Mediterranean island of Lampedusa in the period 1999–2005, Atmos. Environ. 41, 3041–3056]. In this paper we focus on intense SD events detected until September 2006, characterized by large values of the Saharan Dust Event Index (SDEI), the sum of the daily average aerosol optical depth at 500 nm, τ, over the duration of the dust episode. The SDEI index provides an indication about the intensity of SD events, due either to a long duration and/or to high dust optical depth. A total of 24 episodes characterized by large values of SDEI are examined. The NCEP-based maps of geopotential height and temperature at 700 mbar are used to identify the main circulation patterns driving SD to the Central Mediterranean and Lampedusa.Dust transport episodes in summer last for several days, and the corresponding SDEI values are the highest of the year. These episodes are mainly governed by two circulation patterns: the trough extending near the Atlantic coast of Europe and the high pressure system present in North Africa, generally above 25° N. This configuration causes strong south-westerly flows from the Sahara towards Southern Italy. The time evolution of τ for these long SD events shows that the largest values (> 0.3) are usually observed when the two patterns are present simultaneously, while low (< 0.3) τ values are measured when the Atlantic trough influence is weak. Moreover, the most probable loading region typically shows a warm kernel in North-Western Sahara, with a tongue extending north-eastward towards Sicily.In spring, moderate to high τ are measured, and SD episodes last as long as 13 days. Two synoptic configurations can be distinguished. Days with large τ are associated with the 700 mbar geopotential height features typical of summer. Days with moderate τ are found to be characterized by the Saharan high, but with the close low replaced by the Atlantic trough descending West of Africa or above the Iberian peninsula.In winter the typical meteorological conditions are determined by the presence of westerly cyclones. Depressions centered over Portugal, Central/Northern Europe, and Western Mediterranean have been shown to drive dust transport to Lampedusa.

Surface shortwave radiative forcing of different aerosol types in the central Mediterranean

Ground based measurements of aerosol optical depth, τ, and shortwave irradiance at the Mediterranean island of Lampedusa during 2003 and 2004 were used to estimate the surface aerosol shortwave radiative forcing. The shortwave forcing efficiency (FE) was derived at various solar zenith angles, θ, as the derivative of the shortwave irradiance with respect to τ. Values of FE for different classes of particles, namely desert dust, DD, biomass burning/industrial aerosols, BU, and for the whole dataset are derived. At the summer solstice the daily average FE is −86.4 W/m2 for DD, −70.5 W/m2 for BU, and −94.0 W/m2 for the whole dataset. The daily aerosol forcing of DD is much larger than for the other aerosol classes due to the combination of larger forcing efficiency and largest optical depths. The estimated average daily forcing at the summer solstice and equinox for DD is −30 and −24 W/m2, respectively.

Seasonal transport patterns of intense Saharan dust events at the Mediterranean island of Lampedusa

Saharan dust (SD) episodes occurring at the Mediterranean island of Lampedusa (35.52° N, 12.63° E) from May 1999 to December 2005 have been shown to occur in the 26% of the cloud-free days [Meloni, D., di Sarra, A., Biavati, G., DeLuisi, J.J., Monteleone, F., Pace, G., Piacentino, S., Sferlazzo, D.M., 2007. Seasonal behavior of Saharan dust events at the Mediterranean island of Lampedusa in the period 1999–2005, Atmos. Environ. 41, 3041–3056]. In this paper we focus on intense SD events detected until September 2006, characterized by large values of the Saharan Dust Event Index (SDEI), the sum of the daily average aerosol optical depth at 500 nm, τ, over the duration of the dust episode. The SDEI index provides an indication about the intensity of SD events, due either to a long duration and/or to high dust optical depth. A total of 24 episodes characterized by large values of SDEI are examined. The NCEP-based maps of geopotential height and temperature at 700 mbar are used to identify the main circulation patterns driving SD to the Central Mediterranean and Lampedusa. Dust transport episodes in summer last for several days, and the corresponding SDEI values are the highest of the year. These episodes are mainly governed by two circulation patterns: the trough extending near the Atlantic coast of Europe and the high pressure system present in North Africa, generally above 25° N. This configuration causes strong south-westerly flows from the Sahara towards Southern Italy. The time evolution of τ for these long SD events shows that the largest values (> 0.3) are usually observed when the two patterns are present simultaneously, while low (< 0.3) τ values are measured when the Atlantic trough influence is weak. Moreover, the most probable loading region typically shows a warm kernel in North-Western Sahara, with a tongue extending north-eastward towards Sicily. In spring, moderate to high τ are measured, and SD episodes last as long as 13 days. Two synoptic configurations can be distinguished. Days with large τ are associated with the 700 mbar geopotential height features typical of summer. Days with moderate τ are found to be characterized by the Saharan high, but with the close low replaced by the Atlantic trough descending West of Africa or above the Iberian peninsula. In winter the typical meteorological conditions are determined by the presence of westerly cyclones. Depressions centered over Portugal, Central/Northern Europe, and Western Mediterranean have been shown to drive dust transport to Lampedusa.

Seasonal behavior of Saharan dust events at the Mediterranean island of Lampedusa in the period 1999–2005

Multi-filter rotating shadowband radiometer (MFRSR) measurements have been carried out at Lampedusa (35.52°N, 12.63°E) in 1999, and continuously since 2001. This study describes the Saharan dust (SD) events at Lampedusa on the basis of daily average optical depth at 500 nm, τ, and Ångström exponent, α, derived from these observations. Back-trajectories ending at Lampedusa at 2000 and 4000 m altitude were calculated by means of the HYSPLIT model. SD events are identified as those for which the trajectories interact with the mixed layer in places where the surface wind exceeds 7 m s −1, or spend a large fraction of time over the Sahara. The SD days display values of α+Δ α⩽1, with Δ α equal to the standard deviation of the daily α. Out of 911 days with cloud-free intervals, 233 (26%) are classified as SD, and correspond to 111 episodes of various duration, from 1 to 13 consecutive days. The occurrence of SD events is maximum in summer (33%), when also the largest seasonal average of τ (0.40) is measured, and minimum in winter (7%), when the smallest seasonal average of α (0.08) is found. SD days have been identified from the back-trajectories also in days lacking of observations, due to either cloudiness or measurement interruptions. The frequency of occurrence of SD days shows little change with respect to the cloud-free periods (24%). The seasonal distribution shows a peak in May (38%), followed by July (37%). Regions of SD production were derived from the HYSPLIT trajectories and NCEP-reanalysis surface winds. Finally, the MFRSR measurements at the solar zenith angle of 60° have been used to derive the single scattering albedo (SSA) for cases clearly dominated by dust ( τ⩾0.40 and α+Δ α⩽0.5). The average SSA for the whole period is 0.77±0.04 at 415.6 nm and 0.94±0.04 at 868.7 nm.

FokI Polymorphism of the Vitamin D Receptor Gene Correlates with Parameters of Bone Mass and Turnover in a Female Population of the Italian Island of Lampedusa

One of the most promising genetic approaches to dissecting a multifactorial disease is represented by genetically isolated population studies. We studied a genetic marker in a cohort of women living on the Mediterranean island of Lampedusa, a geographically isolated population. Lampedusa, located between the African coast and Sicily, consists of a young genetic isolate (<20 generations) with an exponential growth in the last generations. We analyzed the association between the FokI vitamin D receptor (VDR) gene polymorphism, previously proposed as a predictor of bone mass, with parameters of bone mass and turnover in a cohort of pre- and postmenopausal women living on Lampedusa. In 424 women (277 postmenopausal and 147 premenopausal), allelic frequencies were 49% for the F allele and 51% for the f allele. Using analysis of covariance, we found that subjects with ff genotype exhibited a significantly (P < 0.001) lower lumbar spine bone mass, by dual-energy X-ray absorptiometry, and lower values of bone ultrasonographic parameters (speed of sound and broadband ultrasound attenuation) relative to those with Ff and FF genotypes. Conversely, osteocalcin and serum cross-laps were significantly higher in ff and Ff compared to FF genotype. Our data suggest that FokI VDR polymorphism may contribute to the determination of bone mass and turnover in both pre- and postmenopausal women in this geographically isolated population.

The Upper Pleistocene to Holocene sediments on the Mediterranean island of Lampedusa (Italy)

AbstractThe island of Lampedusa lies on the northern edge of the African continental shelf, but during some Quaternary marine lowstands it was joined to the African continent. The study and dating of the aeolian, alluvial, detrital sediments, calcareous crusts and speleothems have established that the climatic–environmental variations recorded on the island can be related chronologically to those known for northern Libya, Tunisia and the Italian peninsula. During the Last Glacial Maximum, phases of Saharan dust accumulation on Lampedusa occurred, and were coeval with dust accumulation in crater lakes and on high mountains in central‐southern Italy, and with phases of glacial advance in the Apennines and in the Alps. During the late Holocene, accumulation of Saharan dust on Lampedusa occurred but there was little accumulation of dust on the northern side of the Mediterranean Sea. With the new data from Lampedusa, it is possible to envisage two different scenarios of atmospheric circulation relating to the Last Glacial Maximum and to the late Holocene. During the Last Glacial Maximum, southerly atmospheric circulation brought rainfall to the southern slopes of the Alps and to the Apennines. During the late Holocene, a prevalent westerly atmospheric circulation became established in the northern Mediterranean. Copyright © 2004 John Wiley &amp; Sons, Ltd.

Effects of desert dust and ozone on the ultraviolet irradiance at the Mediterranean island of Lampedusa during PAUR II

Observations of the ultraviolet spectral irradiance, tropospheric aerosols, and ozone were carried out at Lampedusa (35.5°N, 12.6°E), during May and June 1999, in conjunction with the Photochemical Activity and Ultraviolet Radiation modulating factors II experiment. Lampedusa is a small Italian island in the Mediterranean, about 100 km off the west coast of Tunisia, North Africa. During the campaign, aerosol transport from Sahara, mainly controlled by the development of high‐pressure systems over North Africa, strongly affected the troposphere at Lampedusa. Aerosol optical depths at 415 nm ranged between 0.14 and 0.91. Dust aerosols with an optical depth of 0.5 at 415 nm produced a reduction of the measured irradiance at 350 nm by about 20%, at a solar zenith angle of 30°, and by about 25% at 60°. The occurrence of large aerosol optical depths was associated with low total ozone values, mainly due to the influence of surface pressure on the stratospheric vertical structure and transport. Thus the aerosol attenuation of the UV irradiance was large when low absorption by ozone occurred, and a large ozone absorption occurred when aerosol attenuation was small. Mostly because of their large variability, aerosols produce larger attenuation effects than ozone on the UV irradiance for wavelengths longer than 315 nm. By neglecting the influence of aerosols on the radiation amplification factors, calculation of the dependence of the UV irradiance on ozone can be significantly underestimated. For the erythemally weighted irradiance a value for the radiation amplification factor between −0.1 and 0.7, depending on the solar zenith angle, has been derived. A simple model to take into account the aerosol effect in the determination of the radiation amplification factor has been developed. By applying this model an erythemal radiation amplification factor between 0.8 and 1.25 is obtained. It is estimated that an aerosol layer of optical depth 0.5 at 415 nm produces a reduction of the erythemal irradiance as large as 25 and 27% at solar zenith angles of 30° and 60°, respectively. When conditions similar to those of Lampedusa occur, i.e., when large aerosol loads may be present, and for certain meteorological conditions, the effects of the aerosol on the surface ultraviolet irradiance cannot be neglected.

Elastomeric modifiers for polyolefin films

Analysis of time series and trends of nitrous oxide (N2O) and halocompounds weekly monitored at the Mediterranean island of Lampedusa are discussed. Atmospheric N2O levels showed a linear upward growth rate of 0.78 ppb yr−1 and mixing ratios comparable with Northern Hemisphere global stations. CFC-11 and CFC-12 time series displayed a decline consistent with their phase-out. Chlorofluorocarbons (CFCs) replacing compounds and SF6 exhibited an increasing temporal behaviour. The most rapid growth rate was recorded for HFC-134a with a value of 9.6% yr−1. The industrial solvents CCl4 and CH3CCl3, banned by the Montreal Protocol, showed opposite trends. While CH3CCl3 reported an expected decay of −1.8 ppt yr−1, an increasing rate of 5.7 ppt yr−1 was recorded for CCl4 and it is probably related to its relatively long lifetime and persisting emissions. Chlorinated halomethanes showed seasonality with a maximum in early April and a minimum at the end of September. Halon-1301 and Halon-1211 displayed a decreasing trend consistent with industry emission estimates.An interspecies correlation analysis gave positive high correlations between HCFC-22 and HFC-134a (+0.84) highlighting the common extensive employment as refrigerants. Sharing sources inferred the high coupling between CH3Cl and CH3Br (+0.73) and between CHCl3 and CH2Cl2 (+0.77). A singular strong relationship (+0.55) between HFC-134a and CH3I suggested the influence of an unknown anthropogenic source of CH3I.Constraining of source and sink distribution was carried out by transport studies. Results were compared with the European Environment Agency (EEA) emission database. In contrast with the emission database results, our back trajectory analysis highlighted the release of large amounts of HFC-134a and SF6 from Eastern Europe. Observations also showed that African SF6 emissions may be considerable. Leakages from SF6 insulated electrical equipments located in the industrialized Northern African areas justify our observations.