281 research outputs found
Locally Produced Foods
A locally-produced diet is more sustainable than other diets
La forêt italienne. Question actuelle et perspectives
Il s'agit d'une traduction «libre» d' un texte
déjà paru dans la revue «Italia Forestale e Montana» où l'auteur aborde la «question forestière
italienne» en s'efforçant de dépasser les aspects techniques et en mettant en évidence quelques
uns des multiples paradoxes qui sont à l'origine de la crise actuelle du monde
forestier
Historical roots and the evolving science of forest management under a systemic perspective
In recent history, both a growing awareness of how scientific and societal uncertainty impacts management decisions and of the intrinsic value of nature have suggested new approaches to forest management, with a growing debate in forest science over the need for a paradigmatic shift from the classic conventional world view, based on determinism, predictability, and output-oriented management, towards a world view that has roots in complex adaptive systems theory and is consistent with a nature-based ethic. A conceptual framework under this context is provided by systemic silviculture. In this discussion, we analyze how this approach can be linked to three fundamental moments of the history of forestry and forest science: the Dauerwald theory, Gurnaud's control method, and the origins of environmental ethics. Relationships with the recent history of forest management science and current research perspectives are also highlighted.4n
The southernmost beech (Fagus sylvatica) forests of Europe (Mount Etna, Italy): ecology, structural stand-type diversity and management implications
The southernmost European beech forests are located in the upper forest vegetation belt on Mount Etna volcano. Their standstructural
patterns were analysed to assess the effects of the site-ecological factors and previous management practices on the
forest structure. Five main structural-silvicultural types were identified among the main beech forest types: coppice, highmountain
coppice (HMCo), high forest, coppice in conversion to high-forest and non-formal stand. A detailed standstructural
analysis was carried out through measured dendrometric parameters and derived structural characters linked to
both the horizontal and the vertical profiles. Plant regeneration processes were also assessed, and several biodiversity
indicators were calculated. The collected data indicate a high variability of beech stand structures in relation to the
heterogeneity of the site-ecological characteristics as well as to the effects of both natural and anthropic disturbance factors.
The occurrence of particular stand structures along the altitude gradient on Mount Etna is evident. It is especially visible in
the multi-stemmed HMCos in relation to the changing, and increasingly limiting, ecological factors, although at higher
altitudes historical anthropic actions (felling) also have had an influence. Inside the Mediterranean area, these stands highlight
their ecological marginality, in terms of both latitude and altitude, especially regarding current climate change processes
Outlining multi-purpose forest inventories to assess the ecosystem approach in forestry
A summary and discussion of selected published results on the current and potential role of forest inventories (with particular
reference to the national ones) are presented in the light of the challenges posed by society and policy decisions in the
environmental sector. The analysis concentrates mainly on the ecological and socio-economic aspects of the question and on
forest inventories’ potential contribution to achieving sustainable forest management.L'articolo è diponibile sul sito dell'editore wwww.tandf.co.uk/journals
New Early Eocene mammalian fauna from western Patagonia, Argentina
Two new fossil mammal localities from the Paleogene of central-western Patagonia are preliminarily described as the basis for a new possible biochronological unit for the early Eocene of Patagonia, correlated as being between two conventional SALMAs, the Riochican (older) and the Vacan subage of the Casamayoran SALMA. The mammal-bearing strata belong to the Middle Chubut River Volcanic-Pyroclastic Complex (northwestern Chubut Province, Argentina), of Paleocene-Eocene age. This complex includes a variety of volcaniclastic, intrusive, pyroclastic, and extrusive rocks deposited after the K-T boundary. Geochronological data taken from nearby volcanic deposits that underlie and overlie the mammal-bearing levels indicate that both faunas are of late early Eocene age (Ypresian-Lutetian boundary). In addition to more than 50 species of mammals, including marsupials, ungulates, and xenarthrans, two lower molars are the oldest evidence of bats in South America. Paleobotanical and palynological evidence from inferred contemporary localities nearby indicate subtropical environments characterized by warm and probably moderately humid climate. Remarkably, this new fauna is tentatively correlated with Eocene mammals from the La Meseta Formation in the Antarctic Peninsula. We conclude that the two localities mentioned above are part of a possible new biochronological unit, but the formal proposal of a new SALMA awaits completion of taxonomic analysis of the materials reported upon here. If the La Meseta fauna is correlated biochronologically to western Patagonia, this also suggests a continental extension of the biogeographic Weddelian Province as far north as central-western Patagonia
HBV quasispecies composition in Lamivudine-failed chronic hepatitis B patients and its influence on virological response to Tenofovir-based rescue therapy
The present study sought to evaluate the structure of HBV quasispecies in Lamivudine (LMV)-failed chronic hepatitis B (CHB) patients and its impact in defining the subsequent virological responses to Tenofovir (TDF)-based rescue-therapy. By analyzing HBV clones encompassing reverse transcriptase (RT) and surface (S) region from LMV-failed and treatment-naïve CHB patients, we identified 5 classical and 12 novel substitutions in HBV/RT and 9 substitutions in immune-epitopes of HBV/S that were significantly associated with LMV failure. In silico analysis showed spatial proximity of some of the newly-identified, mutated RT residues to the RT catalytic centre while most S-substitutions caused alteration in epitope hydrophobicity. TDF administration resulted in virological response in 60% of LMV-failed patients at 24-week but non-response in 40% of patients even after 48-weeks. Significantly high frequencies of 6 S-substitutions and one novel RT-substitution, rtH124N with 6.5-fold-reduced susceptibility to TDF in vitro, were noted at baseline in TDF non-responders than responders. Follow-up studies depicted greater evolutionary drift of HBV quasispecies and significant decline in frequencies of 3 RT and 6 S-substitutions in responder-subgroup after 24-week TDF-therapy while most variants persisted in non-responders. Thus, we identified the HBV-RT/S variants that could potentially predict unfavorable response to LMV/TDF-therapy and impede immune-mediated viral clearance
New Early Eocene Mammalian Fauna from Western Patagonia, Argentina
Two new fossil mammal localities from the Paleogene of central-western Patagonia are preliminarily described as the basis for a new possible biochronological unit for the early Eocene of Patagonia, correlated as being between two conventional SALMAs, the Riochican (older) and the Vacan subage of the Casamayoran SALMA. The mammal-bearing strata belong to the Middle Chubut River Volcanic-Pyroclastic Complex (northwestern Chubut Province, Argentina), of Paleocene-Eocene age. This complex includes a variety of volcaniclastic, intrusive, pyroclastic, and extrusive rocks deposited after the K-T boundary. Geochronological data taken from nearby volcanic deposits that underlie and overlie the mammal-bearing levels indicate that both faunas are of late early Eocene age (Ypresian-Lutetian boundary). In addition to more than 50 species of mammals, including marsupials, ungulates, and xenarthrans, two lower molars are the oldest evidence of bats in South America. Paleobotanical and palynological evidence from inferred contemporary localities nearby indicate subtropical environments characterized by warm and probably moderately humid climate. Remarkably, this new fauna is tentatively correlated with Eocene mammals from the La Meseta Formation in the Antarctic Peninsula. We conclude that the two localities mentioned above are part of a possible new biochronological unit, but the formal proposal of a new SALMA awaits completion of taxonomic analysis of the materials reported upon here. If the La Meseta fauna is correlated biochronologically to western Patagonia, this also suggests a continental extension of the biogeographic Weddelian Province as far north as central-western Patagonia.Facultad de Ciencias Naturales y Muse
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