The Influence of short-term land use change on soil evolution in the centre-south coastal areas of Sardinia

The land use change in short-term (time and space) in the Mediterranean context can be induced by phenomena like destruction of the autochthonous plant species, land abandonment, overgrazing, fire, urbanization (above all for touristic purpose), etc. These phenomena can lead to soil’s degradation conditions causing a loss of physical and biological productivity and the consequent emphasis in desertification processes. Desertification is considered one of the biggest environmental problems in Mediterranean areas (ICCD, 1994), and Sardinia is one of the most affected regions in Europe (UNEP, 1992; Imeson and Emmer, 1992). In Sardinia changes happened during the last decades (such as industrialization, coastal urban areas expansion, etc.) have often resulted in repercussions on the environmental ecosystems and foremost on soils. An important decrease of fertile lands and a consequent increase of marginal and unproductive areas have been observed; this fact has taken to manifest environmental and economic repercussions. In Sardinia such degradation phenomena are particularly evident in coastal areas, where the uncontrolled urbanization and the natural touristic vocation represent relevant impact types. In fact, in 1897 km of coastal lands (500 km are represented by dunal systems) 40% is subjected to deep erosion phenomena, that often are caused by wrong management actions. For these reasons the knowledge of their nature and expansion is of primary importance to carry out correct choices in land use. This work shows an example of a comparative investigation on coastal ecosystems particularly under human pressure. The investigated areas are located along the Centre–North coast of Sardinia. Particularly they concern: a) soils on limestone formations, forestry live oak cover and pasture land use (goat and swine); b) soils on fixed dunes, reforestation with pine and touristic-recreational land use foremost. In the areas several soil profiles have been realized to investigate the influence of the land use change, occurring in short-term in both places, on the evolution and degradation processes of soils

Formation of reactive nitrogen species at biologic heme centers: a potential mechanism of nitric oxide-dependent toxicity.

The peroxidase-catalyzed nitration of tyrosine derivatives by nitrite and hydrogen peroxide has been studied in detail using the enzymes lactoperoxidase (LPO) from bovine milk and horseradish peroxidase (HRP). The results indicate the existence of two competing pathways, in which the nitrating species is either nitrogen dioxide or peroxynitrite. The first pathway involves one-electron oxidation of nitrite by the classical peroxidase intermediates compound I and compound II, whereas in the second pathway peroxynitrite is generated by reaction between enzyme-bound nitrite and hydrogen peroxide. The two mechanisms can be simultaneously operative, and their relative importance depends on the reagent concentrations. With HRP the peroxynitrite pathway contributes significantly only at relatively high nitrite concentrations, but for LPO this represents the main pathway even at relatively low (pathophysiological) nitrite concentrations and explains the high efficiency of the enzyme in the nitration. Myoglobin and hemoglobin are also active in the nitration of phenolic compounds, albeit with lower efficiency compared with peroxidases. In the case of myoglobin, endogenous nitration of the protein has been shown to occur in the absence of substrate. The main nitration site is the heme, but a small fraction of nitrated Tyr146 residue has been identified upon proteolytic digestion and high-performance liquid chromatography/mass spectrometry analysis of the peptide fragments. Preliminary investigation of the nitration of tryptophan derivatives by the peroxidase/nitrite/hydrogen peroxide systems shows that a complex pattern of isomeric nitration products is produced, and this pattern varies with nitrite concentration. Comparative experiments using chemical nitrating agents indicate that at low nitrite concentrations, the enzymatic nitration produces a regioisomeric mixture of nitrotryptophanyl derivatives resembling that obtained using nitrogen dioxide, whereas at high nitrite concentrations the product pattern resembles that obtained using peroxynitrite

I Limiti della sostenibilità: indicatori <i>versus</i> sostenibilità

Il concetto di sostenibilità non è più soltanto controverso. In sede scientifica internazionale viene apertamente contestato. Faremo riferimento agli argomenti di indubbio interesse proposti, nel corso del XX Congresso della IAIA, (International Association for Impact Assessment, Cartagena de India, Colombia, maggio-giugno 2001) da parte di Hobson Bryan, professore di sociologia presso l’Università dell’Alabama, nel corso della sessione ufficiale dedicata alla Urban Sustainability. Attraverso la sequenza: - concetto dell’impronta ecologica (ecological footprint concept), - era dell’esuberanza (age of exuberance), - accettazione acritica della negazione del limite (conrcupian paradigm), - superamento della capacità dell’habitat (overshoot habitat capacity), - l’estensione immotivata della carryng capacity in Phantom carrying capacity, - l’essersi l’uomo esentato dal rispettare le leggi di natura (human exemptionalism). Hobson Bryan giunge alla conclusione che la sostenibilità urbana è impossibile: conclusione tutt’altro che stupefacente, da noi condivisa e riproposta in più occasioni. Dovremmo prendere molto sul serio la complessità prima di parlare a vanvera di sostenibilità giustificativa di ogni intervento o processo (Roe, 1997) e ricordare che il ruolo della scienza, in tema di sostenibilità, non deve essere solo riferito ad una società indubbiamente basata sulla conoscenza, i cui contenuti, da soli, non possono specificatamente essere usati in un malinteso “interest of environmentally appropriate development” (Merkel, 1998.

Formation of Reactive Nitrogen Species at Biological Heme Centers: A Potential Mechanism of Nitric Oxide-Dependent Toxicity

The peroxidase-catalyzed nitration of tyrosine derivatives by nitrite and hydrogen peroxide has been studied in detail using the enzymes lactoperoxidase (LPO) from bovine milk and horseradish peroxidase (HRP). The results indicate the existence of two competing pathways, in which the nitrating species is either nitrogen dioxide or peroxynitrite. The first pathway involves one-electron oxidation of nitrite by the classical peroxidase intermediates compound I and compound II, whereas in the second pathway peroxynitrite is generated by reaction between enzyme-bound nitrite and hydrogen peroxide. The two mechanisms can be simultaneously operative, and their relative importance depends on the reagent concentrations. With HRP the peroxynitrite pathway contributes significantly only at relatively high nitrite concentrations, but for LPO this represents the main pathway even at relatively low (pathophysiological) nitrite concentrations and explains the high efficiency of the enzyme in the nitration. Myoglobin and hemoglobin are also active in the nitration of phenolic compounds, albeit with lower efficiency compared with peroxidases. In the case of myoglobin, endogenous nitration of the protein has been shown to occur in the absence of substrate. The main nitration site is the heme, but a small fraction of nitrated Tyr146 residue has been identified upon proteolytic digestion and high-performance liquid chromatography/ mass spectrometry analysis of the peptide fragments. Preliminary investigation of the nitration of tryptophan derivatives by the peroxidase/nitrite/hydrogen peroxide systems shows that a complex pattern of isomeric nitration products is produced, and this pattern varies with nitrite concentration. Comparative experiments using chemical nitrating agents indicate that at low nitrite concentrations, the enzymatic nitration produces a regioisomeric mixture of nitrotryptophanyl derivatives resembling that obtained using nitrogen dioxide, whereas at high nitrite concentrations the product pattern resembles that obtained using peroxynitrite. Key words: heme proteins, hemoglobin, hydrogen peroxide, myoglobin, nitrite, peroxidases, tryptophan nitration, tyrosine nitration

Soil degradation as a cause of brushwood clear-cutting and grazing in Mediterranean forests

This research shows the early results of a pedological study developed in carbonatic areas of central-eastern Sardinia (Italy). Investigated soils show evident influence of human activity. In particular, the degradation is a conseguence of intense grazing and unplanned brushwood clearcutting (by the indistinct and non selective cutting of grass and shrub land)

SEPOLTURE ANOMALE NELLE TOMBE DEL BA I-III DI TELL ES-SULTAN/ GERICO (SCAVI J. GARSTANG)

La letteratura scientifica inerente i contesti funerari del Levante, si è limitata ad una descrizione superficiale delle sepolture senza procedere nello specifico ad un’analisi dettagliata dei resti osteologici, fondamentale per la comprensione e l’interpretazione dei rituali funerari. In questo contributo si vogliono analizzare in particolar modo le tombe di Gerico scavate dalla prima missione inglese condotta da J. Garstang dal 1930-al 1936. L’importanza di questa necropoli deriva soprattutto, dall’estensione cronologica e dalla continuità delle sequenze stratigrafiche che vanno dall’inizio dell’urbanizzazione in Palestina fino al Bronzo Tardo. Sono state analizzate le fasi del Bronzo Antico, estremamente importanti per comprendere la struttura economica, sociale e ideologica connessa con il fenomeno della sedentarizzazione. L’interesse risiede anche nell’impiego coincidente con la prima esperienza urbana gerichiota che è ben visibile nella necropoli ed è testimoniata dal passaggio dalla sepoltura secondaria a quella primaria, questo a conferma della sedentarizzazione, a partire dal Bronzo Antico IB, degli abitanti di Gerico. Le sepolture primarie prese in esame si distinguono per la singolare posizione fatta assumere al defunto, al momento della deposizione e in alcuni casi anche per il corredo funerario ad esso associato. Si tratta di sepolture provenienti dalla grande tomba A e dalla tomba 351; ognuna delle quali è caratterizzata da un’anomalìa che non trova immediati confronti nel territorio palestinese. La metodologia adottata parte dall’analisi dei diari di scavo e di tutta la documentazione edita e inedita, fino ad una rielaborazione grafica delle piante originali. L’obiettivo finale è comprendere la simbologia che sta dietro al gesto intenzionale per poter così intuire il pensiero religioso che ha portato al singolare trattamento del defunto

The influence of illness-related variables, personal resources and context-related factors on real-life functioning of people with schizophrenia

In people suffering from schizophrenia, major areas of everyday life are impaired, including independent living, productive activities and social relationships. Enhanced understanding of factors that hinder real-life functioning is vital for treatments to translate into more positive outcomes. The goal of the present study was to identify predictors of real-life functioning in people with schizophrenia, and to assess their relative contribution. Based on previous literature and clinical experience, several factors were selected and grouped into three categories: illness-related variables, personal resources and context-related factors. Some of these variables were never investigated before in relationship with real-life functioning. In 921 patients with schizophrenia living in the community, we found that variables relevant to the disease, personal resources and social context explain 53.8% of real-life functioning variance in a structural equation model. Neurocognition exhibited the strongest, though indirect, association with real-life functioning. Positive symptoms and disorganization, as well as avolition, proved to have significant direct and indirect effects, while depression had no significant association and poor emotional expression was only indirectly and weakly related to real-life functioning. Availability of a disability pension and access to social and family incentives also showed a significant direct association with functioning. Social cognition, functional capacity, resilience, internalized stigma and engagement with mental health services served as mediators. The observed complex associations among investigated predictors, mediators and real-life functioning strongly suggest that integrated and personalized programs should be provided as standard treatment to people with schizophrenia