Heavy Metal Contents and Distribution in Coastal Sediments of the Gulf of Trieste (Northern Adriatic Sea, Italy)

A set of ten heavy metals (Al, As, Cd, Cr, Cu, Hg, Ni, Pb, V, and Zn) was investigated in surface sediments (0–5 cm) collected in 21 sites of the Gulf of Trieste, Northern Adriatic Sea (Italy). The aim of this work was to obtain a preliminary assessment about the levels and spatial distribution of these selected elements. Ancillary parameters such as grain size, total organic carbon, and total nitrogen were also determined. The enrichment factor was calculated to discriminate if a natural condition or a status of anthropogenic contamination occurs. In addition, a set of sediment quality guidelines, mean effect low range and effect medium range quotients, was also applied in order to predict the probability of adverse biological effects on the benthic community.     

A pioneering survey of deep-diving and off-shore cetaceans in the northern South China Sea

A pioneering boat-based survey was conducted in 2019, to gather baseline information regarding the presence, composition, relative abundance, and spatial distribution of deep-diving and off-shore cetaceans in the northern South China Sea (SCS). A total of 27 sightings comprising at least 8 cetacean species were recorded during the 13-day survey, including 5 deep-diving species (i.e. Risso's dolphin [Grampus griseus], short-finned pilot whale [Globicephala macrorhynchus], sperm whale [Physeter macrocephalus], Cuvier's beaked whale [Ziphius cavirostris], and an unidentified beaked whale [either the ginkgo-toothed beaked whale, Mesoplodon ginkgodens, or Deraniyagala's beaked whale, Mesoplodon hotaula]), as well as 3 off-shore dolphins (i.e. pantropical spotted dolphin [Stenella attenuate], striped dolphin [Stenella coeruleoalba], and Fraser's dolphin [Lagenodelphis hosei]). With the exception of pantropical spotted dolphins, all other species were sighted and recorded at sea in the northern SCS for the first time. The pantropical spotted dolphin was the most frequently sighted species, comprising 30% of the total sightings. Deep-diving cetaceans were mainly sighted in the northern Xisha Archipelago, whereas off-shore dolphins were distributed across the survey area. The pantropical spotted dolphin was observed in aggregations of more than 100 individuals and nearly all encountered species included calves; these findings suggested that the survey area functions as an important feeding and calving ground for various cetacean species. This pioneering survey provides fundamental information regarding cetacean fauna in the northern SCS and highlights the need to strengthen research and conservation efforts concerning these species.     

Spatio-temporal modelling of broad scale heterogeneity in soil moisture content: a basis for an ecologically meaningful classification of soil landscapes

We describe the classification of landscapes characterised bymineral soil using a model that calculates soil moisture availability on amonthly basis. Scotland is used as a case study area. The model uses potentialsoil moisture deficit, estimated using broad scale (40 × 40 km)climate patterns, in conjunction with meteorological station measurements toobtain finer scale values of climatic soil moisture deficit. Point estimates ofsoil available water are obtained for soil characteristics using appropriatepedotransfer functions, and geostatistical techniques are used to upscale theresults and interpolate to a 1-km grid. Known heterogeneityin soil physical characteristics is used to provide local corrections to thepotential soil moisture deficit, estimated using the climatic variables above.Temporal profiles of monthly water content are modelled for each1-km location and classified into six classes usingunsupervised cluster analysis. The spatial distribution of these classesreflects regional variations in the availability of moisture and energy, onwhich finer-grained topographic patterns are superimposed. In the case study,the broad scale spatial heterogeneity of heathlands and grasslands on mineralsoils in Scotland is shown to be strongly related to the soil moistureclassification. The results can be used in studies investigating the patternsofdistribution of communities at the landscape and regional scale.This revised version was published online in May 2005 with corrections to the Cover Date.     

The environmental movement and labor in global capitalism: Lessons from the case of the Headwaters Forest

Employing the case of theredwood Headwaters forest in rural NorthernCalifornia, this paper investigates the extentto which an anti-corporate progressive alliancebetween labor and the environmental movement ispossible in contemporary global capitalism.Progressive alliances between labor and theenvironmental movement have been historicallydifficult. This has been particularly the casein the timber industry, where companies havebeen able to mobilize workers againstenvironmentalists' designs. The caseillustrates the events that led to the purchaseof the Headwaters Forest by the state ofCalifornia and the Federal Government fromPacific Lumber. This is a subsidiary of Maxxam,a corporation with interests in a variety ofeconomic sectors. The objective was to haltMaxxam's rampant deforestation of old growthredwood. Though conflict between labor andenvironmentalists existed, the casedemonstrates that the labor and theenvironmental movement were united againstMaxxam. They, however, were not completelysuccessful in their struggle as Maxxam greatlybenefited from the state-sponsored landpurchase. Maxxam gained economically, was ableto shape the ideological framework throughwhich the purchasing agreement was achieved,and extended its hegemony over the state. Thisoutcome cast doubts on the possibility thatcurrent forms of environmental protection couldtranscend commodified and reductionistpostures. Simultaneously, the existence of acommon anti-corporate consciousness among largesegments of labor and the environmentalmovement makes the environment a contestedterrain and allows for some optimism about thefuture of the struggle for ecologically soundsocial arrangements.     

Probing quantum commutation rules by addition and subtraction of single photons to/from a light field

The possibility of arbitrarily "adding" and "subtracting" single photons to and from a light field may give access to a complete engineering of quantum states and to fundamental quantum phenomena. We experimentally implemented simple alternated sequences of photon creation and annihilation on a thermal field and used quantum tomography to verify the peculiar character of the resulting light states. In particular, as the final states depend on the order in which the two actions are performed, we directly observed the noncommutativity of the creation and annihilation operators, one of the cardinal concepts of quantum mechanics, at the basis of the quantum behavior of light. These results represent a step toward the full quantum control of a field and may provide new resources for quantum information protocols.     

Effects of water content and N addition on potential greenhouse gas production from two differently textured soils under laboratory conditions

GHGs production and emission may vary depending on soil physical properties, water management and fertilization. Two paddy soils characterized by different texture were incubated to evaluate the impact of flooding (permanent or intermittent) and N addition on potential N₂O, CH₄ and CO₂ production and release into atmosphere and soil solution. Relationships with volumetric water content (VWC) and water filled pore space (WFPS) were evaluated. Overall, the finer clayey soil (CL) produced 58% more CH₄ than the coarser sandy soil (SA) and showed an earlier sink to source transition; the difference was lower with N addition. Permanent flooding favoured the amount of dissolved CH₄. SA produced more N₂O emissions than CL under permanent flooding (31.0 vs. 3.7%); an opposite pattern was observed for dissolved N₂O (16.4 vs. 52.7%). Fertilization increased N₂O emissions under dry conditions in CL and under flooding in SA.

Our findings showed that i) VWC had a larger influence on N₂O and CH₄ emissions than WFPS, ii) soil type influenced the gas release into atmosphere or soil solution and the timing of sink to source transition in CH₄ emissions. Further investigation on timing of fertilization and drainage are needed to improve climate change mitigation strategies.     

Simulation of soil types in Teramo province (Central Italy) with terrain parameters and remote sensing data

Soil surveys are an essential source of information for land management although a limited budget often reduces the amount of data available. Even if the dataset is limited, geostatistics can provide a valid estimation tool through a weighted moving average interpolation (kriging). Often, however, the spatial variability of soil properties appears smoothed and short range variability is underestimated by this kind of interpolation technique. A more realistic distribution of a given variable on the territory can be obtained through models based on stochastic simulation.     

Model studies on the photosensitized isomerization of bixin

The photosensitized isomerization reaction of the natural cis carotenoid bixin (methyl hydrogen 9'-cis-6, 6'-diapocarotene-6, 6'-dioate) with rose bengal or methylene blue as the sensitizer in acetonitrile/methanol (1:1) solution was studied using UV-vis spectroscopy, high-performance liquid chromatography (HPLC), and time-resolved spectroscopic techniques, such as laser-flash photolysis and singlet oxygen phosphorescence detection. In both N(2)- and air-saturated solutions, the main product formed was all-trans-bixin. The observed isomerization rate constants, k(obs), decreased in the presence of air or with increase in the bixin concentration, suggesting the participation of the excited triplet state of bixin, (3)Bix, as precursor of the cis--> trans process. On the other hand, bixin solutions in the absence of sensitizer and/or light did not degrade, indicating that the ground state of bixin is stable to thermal isomerization at room temperature. Time-resolved spectroscopic experiments confirmed the formation of the excited triplet state of bixin and its deactivation by ground state bixin and molecular oxygen quenching processes. The primary isomerization products only degraded in the presence of air and under prolonged illumination conditions, probably due to the formation of oxidation products by reaction with singlet molecular oxygen. An energy-transfer mechanism was used to explain the observed results for the bixin transformations, and the consequences for food color are discussed.     

Interactions of three s-triazines with humic acids of different structure

The adsorption of three s-triazines (atrazine, terbutylazine, and simazine) on three different humic acids (HAs), before and after acidic hydrolysis, was studied at four diverse pH values from 3 to 4.5. The Freundlich sorption affinity (K(f)) and intensity (1/n) of s-triazines were related to the chemical and structural composition of HA and used in a multivariate statistical analysis. At low pH, the sorption values for s-triazines were not directly justified by the content of carboxyl groups in original HA, while only an increase of phenolic carbons in hydrolyzed HA supported the increased s-triazine adsorption. The structural composition of both s-triazines and humic samples explained 86% of the significance in multivariate analyses, whereas the role of pH remained hidden in only 14% of the statistical significance. Adsorption of s-triazines was mainly related to carbon content, hydrophobicity, and aromaticity of HA, thereby implying a predominant binding role of weak dispersive forces. Steric properties explained the larger adsorption affinity of atrazine and terbutylazine with respect to simazine. The occurrence of charge-transfer interactions between atrazine and mainly hydrolyzed HA was further suggested by the increased number of free radicals detected in atrazine-HA complexes at different pH values. Charge-transfer interactions were postulated to occur when HA conformations became progressively controlled by aromatic components. This work indicates that humic matter rich in hydrophobic and aromatic constituents is more likely to adsorb s-triazines and reduce their environmental mobility.