429 research outputs found

    The C23A system, an exmaple of quantitative control of plant growth associated with a data base

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    The architecture of the C23A (Chambers de Culture Automatique en Atmosphere Artificielles) system for the controlled study of plant physiology is described. A modular plant growth chambers and associated instruments (I.R. CO2 analyser, Mass spectrometer and Chemical analyser); network of frontal processors controlling this apparatus; a central computer for the periodic control and the multiplex work of processors; and a network of terminal computers able to ask the data base for data processing and modeling are discussed. Examples of present results are given. A growth curve analysis study of CO2 and O2 gas exchanges of shoots and roots, and daily evolution of algal photosynthesis and of the pools of dissolved CO2 in sea water are discussed

    Experimental, Theoretical and Numerical Evaluation of the Stiffness of a Soil-Foundation Model by Shaking-Table Test

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    A well-controlled test was carried out on a Leighton Buzzard sand-shallow foundation system by means of the six-degree-of-freedom shaking table available at the University of Bristol. The foundation consists of a concrete block located into a flexible shear-stack (Taylor et al., 1994) filled up to 1.00 m with the sand. During the test the block was subjected to a centered vertical load and to one direction sine dwell-type acceleration applied at the base of the shear stack. The static and dynamic sand properties were evaluated through different laboratory tests, among them resonant column tests, cyclic and monotonic loading torsional shear tests were performed (Mazzarella, 1999). A comprehensive network of accelerometers and displacement transducers was used to check the static and dynamic soil-foundation interaction (Maugeri et al., 1999a). The impedance functions (Gazetas, 1991) were evaluated and then compared with the experimental results. Finally, the experimental results were compared with the numerical ones obtained by means of a FEM code (Massimino, 1999) developed at the University of Catania

    Study of the relationship between photosynthesis, respiration, transpiration, and mineral nutrition in wheat

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    The growth of wheat (triticum aestivum) was studied in an enclosed controlled environment for a period of 70 days. The exchange of gases (photosynthesis, respiration), water (transpiration) and the consumption of mineral elements (nitrogen, phosphorus, potassium) were continuously measured. The dynamical relations observed in the different physiological functions, under the influence of growth and in response to environment modifications are presented. The influence of carbon dioxide content during growth (normal or double percentage) was made clear

    A counterfactual approach to measure the impact of wet grassland conservation on UK breeding bird populations

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    Wet grassland wader populations in the United Kingdom have experienced severe declines over the last three decades. To help mitigate these declines, the Royal Society for the Protection of Birds (RSPB) has restored and managed lowland wet grassland nature reserves to benefit these and other species. However, the impact that these reserves have on bird population trends has not been experimentally evaluated, as appropriate control populations do not readily exist. In this study, we compare population trends from 1994 ‐ 2018 for five bird species of conservation concern that breed on these nature reserves with counterfactual trends using matched breeding bird survey observations. Our results showed positive effects of conservation interventions for all four wader species that these reserves aim to benefit: Lapwing (Vanellus vanellus), Redshank (Tringa totanus), Curlew (Numenius arquata) and Snipe (Gallinago gallinago). There was no positive effect of conservation interventions on reserves for the passerine, Yellow Wagtail (Motacilla flava). We compared reserve trends with three different counterfactuals, based on different scenarios of how reserve populations could have developed in the absence of conservation, and found that reserve trends performed better regardless of the counterfactual used. Our approach using monitoring data to produce valid counterfactual controls is a broadly applicable method allowing large‐scale evaluation of conservation impact

    Als‐associated sod1(G93a) decreases serca pump levels and increases store‐operated ca2+ entry in primary spinal cord astrocytes from a transgenic mouse model

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    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder characterized by the selective death of motor neurons (MNs), probably by a combination of cell- and non-cell-autonomous processes. The past decades have brought many important insights into the role of astrocytes in nervous system function and disease, including the implication in ALS pathogenesis possibly through the impairment of Ca2+-dependent astrocyte-MN cross-talk. In this respect, it has been recently proposed that altered astrocytic store-operated Ca2+ entry (SOCE) may underlie aberrant gliotransmitter release and astrocyte-mediated neurotoxicity in ALS. These observations prompted us to a thorough investigation of SOCE in primary astrocytes from the spinal cord of the SOD1(G93A) ALS mouse model in comparison with the SOD1(WT)-expressing controls. To this purpose, we employed, for the first time in the field, genetically-encoded Ca2+ indicators, allowing the direct assessment of Ca2+ fluctuations in different cell domains. We found increased SOCE, associated with decreased expression of the sarco-endoplasmic reticulum Ca2+-ATPase and lower ER resting Ca2+ concentration in SOD1(G93A) astrocytes compared to control cells. Such findings add novel insights into the involvement of astrocytes in ALS MN damage

    BCR-ABL1 doubling-times and halving-times may predict CML response to tyrosine kinase inhibitors

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    In Chronic Myeloid Leukemia (CML), successful treatment requires accurate molecular monitoring to evaluate disease response and provide timely interventions for patients failing to achieve the desired outcomes. We wanted to determine whether measuring BCR-ABL1 mRNA doubling-times (DTs) could distinguish inconsequential rises in the oncogene’s expression from resistance to tyrosine kinase inhibitors (TKIs). Thus, we retrospectively examined BCR-ABL1 evolution in 305 chronic-phase CML patients receiving imatinib mesylate (IM) as a first line treatment. Patients were subdivided in two groups: those with a confirmed rise in BCR-ABL1 transcripts without MR3.0 loss and those failing IM. We found that the DTs of the former patients were significantly longer than those of patients developing IM resistance (57.80 vs. 41.45 days, p = 0.0114). Interestingly, the DT values of individuals failing second-generation (2G) TKIs after developing IM resistance were considerably shorter than those observed at the time of IM failure (27.20 vs. 41.45 days; p = 0.0035). We next wanted to establish if decreases in BCR-ABL1 transcripts would identify subjects likely to obtain deep molecular responses. We therefore analyzed the BCR-ABL1 halving-times (HTs) of a different cohort comprising 174 individuals receiving IM in first line and observed that, regardless of the time point selected for our analyses (6, 12, or 18 months), HTs were significantly shorter in subjects achieving superior molecular responses (p = 0.002 at 6 months; p < 0.001 at 12 months; p = 0.0099 at 18 months). Moreover, 50 patients receiving 2G TKIs as first line therapy and obtaining an MR3.0 (after 6 months; p = 0.003) or an MR4.0 (after 12 months; p = 0.019) displayed significantly shorter HTs than individuals lacking these molecular responses. Our findings suggest that BCR-ABL1 DTs and HTs are reliable tools to, respectively, identify subjects in MR3.0 that are failing their assigned TKI or to recognize patients likely to achieve deep molecular responses that should be considered for treatment discontinuation

    Large-scale spatial distribution of breeding Barn Swallows Hirundo rustica in relation to cattle farming

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    Capsule: The information on the spatial distribution of cattle farming stored in public bovine computerized databases can predict the distribution and abundance of breeding Barn Swallow Hirundo rustica L. across Europe. Aims: To develop and validate models of habitat factors which account for the distribution of breeding Barn Swallow colonies. Results: The models were based on data on the distribution of cattle farming provided by the public Bovine Computerized Database of the Regione Lombardia (northern Italy). Cattle distribution was a strong predictor of presence and size of Barn Swallow colonies as well as of the number of swallow colonies in a municipality. The models were robust and passed a cross-validation procedure and were used to estimate the spatial distribution of about 116,000 breeding pairs in awide area (8695 km(2)) of the low Po plain of northern Italy in 2001. Conclusions: Bovine computerized databases are mandatory in all European Union (EU) countries according to the EU Regulation (CE) 1760/2000. They may serve as a basis for wide scale modelling of the distribution and abundance of breeding Barn Swallow in Europe
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