240 research outputs found

    Oil Palm Agroforestry Can Achieve Economic and Environmental Gains as Indicated by Multifunctional Land Equivalent Ratios

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    Driven by increased global demand for vegetable oil in the food and biofuel sectors, oil palm plantations based on monoculture technology have expanded into lowland tropical forests. Interest in diversified, mixed oil palm systems is increasing as these might increase efficiency of the use of land and other resources, reduce farmer risk, and decrease greenhouse gas (GHG) emissions per unit product. Land Equivalent Ratio for provisioning services (LERP) values above 1.0 show that at least some diversified systems use land more efficiently than monocultures and are thus “land sparing,” where monoculture LERP cannot exceed 1.0. Diversification also modifies climate and water regulating functions (“land sharing”) relative to a forest reference, as indicated in the LERR index. A “multifunctional” LERM indicator combines both; land sparing plus land sharing effects jointly determine expected regulating services. Empirical assessment of multiple ecosystem services in agricultural landscapes is assisted by models that synthesise process-based knowledge, especially for perennial systems where well-designed experiments require a full production cycle, and are costly and scarce. Agroforestry models explore spacing, intercropping and soil management options, predicting harvestable yields, impacts on water flows, nutrient leaching, and greenhouse gas emissions. We used the process-based Water, Nutrient and Light Capture in Agroforestry System (WaNuLCAS) model to explore mixed oil palm + cocoa and oil palm + pepper intercrop systems with modified (“double row”) planting patterns for Indonesian contexts and estimated consequences for the carbon footprint. The oil palm + cocoa intercrop provided a high LERP (1.4), while also replenishing more ground water and having a lower C footprint. This combination also has a return to labour equal to that in oil palm monocultures and a higher benefit cost ratio than the oil palm + pepper combination that maximizes Net Present Value. Oil palm + cocoa systems are also less sensitive to price uncertainty for oil palm, and buffer for oil palm and cocoa production risks, assumed to be independent of each other. Considerable economic and environmental system improvements appear to be feasible through mixed oil palm systems and diversification as a pathway to intensification deserves full attention of research and policy development.</p

    Immunopathogenesis and Immune Modulation of Venezuelan Equine Encephalitis Virus-Induced Disease in the Mouse

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    AbstractThe course of Venezuelan equine encephalitis (VEE) disease in immunodeficient and immunologically normal mice was compared to define the role of the immune system in this disease process. Immunocompetent mice infected with VEE exhibited a biphasic illness characterized by an early self-limiting lymphoid phase and a fatal CNS phase. The lymphoid phase of the illness was characterized by extensive viral replication within spleen, thymus, Peyer's patches, and lymph nodes, was accompanied by a high-titered serum viremia, and resolved with the production of VEE-specific IgM class antibody at 72 h postinfection (p.i.). Immunocompetent animals survived an average of 6.8 ± 1.2 days before succumbing to fulminant encephalitis. In contrast, SCID mice infected with VEE showed a persistent replication of virus throughout all organs tested beginning at 24 h p.i. VEE-infected SCID mice exhibited a severe spongiform encephalopathy with 100% mortality and an average survival time of 8.9 ± 0.9 days. These studies indicated that the characteristic organ tropism of VEE in the mouse is due in large part to an early anti-viral state, the establishment of which is dependent upon the presence of an intact immune system. Finally, the CNS pathology in a VEE-infected mouse had a significant immunologic component. However, in contrast to other neurovirulent alphaviruses, VEE was directly cytopathic for the cells of the CNS, even in the absence of an immune response

    Silent cerebral infarct after cardiac catheterization as detected by diffusion weighted Magnetic Resonance Imaging: a randomized comparison of radial and femoral arterial approaches

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    Background and objective: Cerebral microembolism detected by transcranial Doppler (TCD) occurs systematically during cardiac catheterization, but its clinical relevance, remains unknown. Studies suggest that asymptomatic embolic cerebral infarction detectable by diffusion-weighted (DW) MRI might exist after percutaneous cardiac interventions with a frequency as high as 15 to 22% of cases. We have set up, for the first time, a prospective multicenter trial to assess the rate of silent cerebral infarction after cardiac catheterization and to compare the impact of the arterial access site, comparing radial and femoral access, on this phenomenon. Study design: This prospective study will be performed in patients with severe aortic valve stenosis. To assess the occurrence of cerebral infarction, all patients will undergo cerebral DW-MRI and neurological assessment within 24 hours before, and 48 hours after cardiac catheterization and retrograde catheterization of the aortic valve. Randomization for the access site will be performed before coronary angiography. A subgroup will be monitored by transcranial power M-mode Doppler during cardiac catheterization to observe cerebral blood flow and track emboli. Neuropsychological tests will also be recorded in a subgroup of patients before and after the interventional procedures to assess the impact of silent brain injury on potential cognitive decline. The primary end-point of the study is a direct comparison of ischemic cerebral lesions as detected by serial cerebral DW-MRI between patients explored by radial access and patients explored by femoral access. Secondary end-points include comparison of neuropsychological test performance and number of microembolism signals observed in the two groups. Implications: Using serial DW-MRI, silent cerebral infarction rate will be defined and the potential influence of vascular access site will be evaluated. Silent cerebral infarction might be a major concern during cardiac catheterization and its potential relationship to cognitive decline needs to be assessed. Study registration: The SCIPION study is registered through National Institutes of Health-sponsored clinical trials registry and has been assigned the Identifier: NCT 00329979

    Klassische Moderne. Un paradigma del Novecento

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    Il libro, che pubblica gli atti del convegno internazionale, svoltosi a Roma nel maggio del 2007 nell’ambito della ricerca PRIN-2005 (Università di Roma La Sapienza, Trento, Bari e Urbino), analizza il periodo della cultura tedesca della fine-secolo con particolare attenzione ai personaggi e ai movimenti che si sono collocati negli “spazi intermedi”, intesi non solo e non tanto come zone di confine in senso territoriale, quanto piuttosto come zone di interscambio culturale e disciplinare, come tentativi di “superamento” degli ordini mentali e culturali costituiti. L’ambito cronologico che il gruppo di ricerca prende in esame va da 1888 al 1933. La periodizzazione proposta vuole rinviare a quella serie di movimenti e di pensatori che hanno dato il via alla messa in discussione di quei valori costituiti, dalla cui frammentazione è nata la cultura del “secolo breve”. In questo periodo, a partire dalla Jahrhundertwende, sono state elaborate e sperimentate nella prassi letteraria e artistica, una serie di teorie, una serie di “visioni del mondo” che implicavano tanto una pratica produttiva quanto un ruolo dell’artista e dell’arte quanto una visione più generale dei cambiamenti epocali e dell’epoca moderna. Tali teorie e pratiche artistiche, di vario genere e di vario livello, costituiscono un patrimonio concettuale perché in esse si trovano sperimentate e a volte anticipate molte questioni che oggi sono di estrema attualità: dal rapporto uomo-macchina al rapporto parola-immagine, dalla definizione degli spazi urbani alla questione della guerra, dalla ricerca della identità monoculturale alla presa d’atto dell’esistenza dell’estraneo. Queste varie problematiche sono state espresse in termini linguistici nuovi giacché gli autori si sono posti – teoricamente e praticamente – il problema del linguaggio artistico e ne hanno modificato (a volte radicalmente) i codici espressivi. Il libro di divide in tre parti: I: Per una definizione della Klassische Moderne che presenta l’ampia e animata discussione sulla stessa definizione teorica del movimento artistico-culturale, sia sui termini cronologici di questa nuova periodizzazione. Questa parte raccoglie i contributi di Aldo Venturelli, Helmut Kiesel e Fabrizio Cambi. II: La rivoluzione delle forme, che analizza la produzione delle avanguardie (sia pure definite “marginali” ) e prende in considerazione anche aspetti della produzione musicale, nonché forme di narratologia e nuove forme di scrittura. Questa seconda parte pubblica i saggi di Mauro Ponzi, Rosmarie Keller, Silvio Vietta, Hans Dieter Zimmermann, Elio Matassi e Sabine Meine. III: La fucina dei nuovi linguaggi che analizza l’innovazione dei linguaggi artistici sull’esempio di autori meno radicali che quelli delle avanguardie storiche. Questi autori, tipici esponenti della Klassische Moderne, hanno cercato di coniugare l’innovazione dei linguaggi con il recupero di alcuni aspetti della tradizione. Nella terza parte del volume vengono pubblicati i saggi di Alain Montandon, Giovanni Tateo, Gouseppe Farese, Gabriella Rovagnati, Sabine Schneider e Alessandro Fambrini
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