1,995 research outputs found

    Tracking autophagy during proliferation and differentiation of trypanosoma brucei

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    Autophagy is a lysosome-dependent degradation mechanism that sequesters target cargo into autophagosomal vesicles. The Trypanosoma brucei genome contains apparent orthologues of several autophagy-related proteins including an ATG8 family. These ubiquitin-like proteins are required for autophagosome membrane formation, but our studies show that ATG8.3 is atypical. To investigate the function of other ATG proteins, RNAi compatible T. brucei were modified to function as autophagy reporter lines by expressing only either YFP-ATG8.1 or YFP-ATG8.2. In the insect procyclic lifecycle stage, independent RNAi down-regulation of ATG3 or ATG7 generated autophagy-defective mutants and confirmed a pro-survival role for autophagy in the procyclic form nutrient starvation response. Similarly, RNAi depletion of ATG5 or ATG7 in the bloodstream form disrupted autophagy, but did not impede proliferation. Further characterisation showed bloodstream form autophagy mutants retain the capacity to undergo the complex cellular remodelling that occurs during differentiation to the procyclic form and are equally susceptible to dihydroxyacetone-induced cell death as wild type parasites, not supporting a role for autophagy in this cell death mechanism. The RNAi reporter system developed, which also identified TOR1 as a negative regulator controlling YFP-ATG8.2 but not YFP-ATG8.1 autophagosome formation, will enable further targeted analysis of the mechanisms and function of autophagy in the medically relevant bloodstream form of T. brucei

    Mechanisation of different logging operations : environmental impact assessment using life cycle assessment (LCA) approach

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    Different logging systems (or harvesting systems) can be used for wood extraction. Cable logging system is typically carried out on steep slopes and other rough terrain. In these contexts, also cable yarding can be an efficient and effective harvesting system. Ninety-five per cent of timber production in southern Italy comes from terrain classified as very steep slope, limiting the use of machines for ground-based extraction. Cable extraction is a desirable alternative to either a skidder or forwarder on a sensitive site. To each harvesting system a different environmental load is associated depending on machine productivity and site characteristics. In this study, three different logging systems were analysed and compared using the Life Cycle Assessment approach. The compared logging systems are characterised by felling with chainsaw and three different extraction methods: by farm tractors equipped with a winch; by a skidder; and by a cable crane. The Full Tree harvesting method was adopted for both felling sites; trees were felled and transported to roadside with branches and top intact. The functional unit is 1 m3of wood; the system boundary involves all the operations carried out in the forestry (felling, bunching and extraction) and all the related inputs (diesel fuel, lubricating oil, capital goods such as chainsaw, tractors, skidder, cable yarder) and related emissions. Inventory data were collected in three different test sites located in southern Italy and concern working times, productivity, wood yield, fuel consumption. The cable yarder shows the worst performances for 7 of the 8 evaluated impact categories. The use of skidder shows a lower impact for 5 of the 8 evaluated impact categories while, for the remaining 3, the best performances are achieved by the logging system in which tractor is used. For climate change, the impact is equal to 8.57, 8.04 and 10.46 kg CO2eq/m3for the harvesting system with extraction carried out using tractor, skidder and cable yarder, respectively

    Preferential use of the perchlorate over the nitrate in the respiratory processes mediated by the Bacterium Azospira sp. OGA 24

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    Here we report the results obtained for a strain isolated from a polluted site and classified as Azospira sp. OGA 24. The capability of OGA 24 to utilize perchlorate and nitrate and the regulation of pathways were investigated by growth kinetic studies and analysis of messenger RNA (mRNA) expression of the genes of perchlorate reductase alpha subunit (pcrA), chlorite dismutase (cld), and periplasmic nitrate reductase large subunit (napA). In aerobic conditions and in a minimal medium containing 10 mM acetate as carbon source, 5.6 ± 0.34 mmol L-1 perchlorate or 9.7 ± 0.22 mmol L-1 nitrate were efficiently reduced during the growth with 10 mM of either perchlorate or nitrate. In anaerobiosis, napA was completely inhibited in the presence of perchlorate as the only electron acceptor, pcrA was barely detectable in nitrate-reducing conditions. The cell growth kinetics were in accordance with expression data, indicating a separation of nitrate and perchlorate respiration pathways. In the presence of both compounds, anaerobic nitrate consumption was reduced to 50% (4.9 ± 0.4 vs. 9.8 ± 0.15 mmol L-1 without perchlorate), while that of perchlorate was not affected (7.2 ± 0.5 vs. 6.9 ± 0.6 mmol L-1 without nitrate). Expression analysis confirmed the negative effect of perchlorate on nitrate respiration. Based on sequence analysis of the considered genes and 16S ribosomal gene (rDNA), the taxonomic position of Azospira sp. OGA 24 in the perchlorate respiring bacteria (PRB) group was further defined by classifying it in the oryzae species. The respiratory characteristics of OGA 24 strain make it very attractive in terms of potential applications in the bioremediation of environments exposed to perchlorate salts

    Plethysmography system to monitor the jugular venous pulse: A feasibility study

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    Cerebral venous outflow is investigated in the diagnosis of heart failure through the monitoring of jugular venous pulse, an indicator to assess cardiovascular diseases. The jugular venous pulse is a weak signal stemming from the lying internal jugular vein and often invasive methodolo-gies requiring surgery are mandatory to detect it. Jugular venous pulse can also be extrapolated via the ultrasound technique, but it requires a qualified healthcare operator to perform the exami-nation. In this work, a wireless, user-friendly, wearable device for plethysmography is developed to investigate the possibility of monitoring the jugular venous pulse non-invasively. The proposed device can monitor the jugular venous pulse and the electrocardiogram synchronously. To study the feasibility of using the proposed device to detect physiological variables, several measurements were carried out on healthy subjects by considering three different postures: supine, sitting, and upright. Data acquired in the experiment were properly filtered to highlight the cardiac oscillation and remove the breathing contribution, which causes a considerable shift in the amplitude of signals. To evaluate the proper functioning of the wearable device for plethysmography, a comparison with the ultrasound technique was carried out. As a satisfactory result, the acquired signals resemble the typical jugular venous pulse waveforms found in literature

    The environmental noise level in the rejuvenation pruning on centuries-old olive tree

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    ArticleIn the Italian agricultural economy, olive cultivation plays a fundamental role, and this is especially true for the southern regions where almost all cultivation is spread. In Calabria, in particular, olive cultivation has seen over the last few decades significantly improve the quality of production also as a result of investments aimed at the creation of new mechanizable plants and/or the modernization of existing ones; today some areas have got both PDO and PGI certification. In the ‘Piana di Gioia Tauro’, located north-west of the Reggio Calabria metropolitan area, olive growing extends over 20,000 hectares and the presence of centuries-old olive tree is still widespread. The olive varieties mainly belong to the local cultivars of ‘Sinopolese’ and ‘Ottobratica’, characterized by a remarkable rusticity and high development, perhaps unique in the world; they reach 20–25 meters high, forming what is called a ‘forest of olive trees’. The pruning operations are carried out by means of chainsaws of different power and size whereby, in addition to the previously described difficulties, operators are exposed to prolonged periods of noise levels. The purpose of this study is precisely to assess the exposure of operators to this particular olive grove. The aim is to identify the acoustic levels generated by the two pruning and cross-cutting activities, the risk thresholds and the exposure to which the individual workers of the two work sites are subjected, giving indications on the appropriate safety distances to maintain (according to current regulations) compared to noise sources

    Uncovering genetic parameters and environmental influences on fertility, milk production, and quality in autochthonous Reggiana cattle

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    Reggiana is a local cattle breed from northern Italy known for its rusticity and profitability, due to the production of branded Parmigiano Reggiano cheese. To ensure the persistence of such profitability in the long term, an adequate breeding program is required. To this aim, in the present study we estimate the genetic parameters of the main productive and reproductive traits, and we evaluate the effect of genotype by environment interaction (GxE) on these traits using 2 environmental covariates: (1) productivity and (2) temperature-humidity index (THI). Milk, fat, protein, and casein yield were considered as daily production traits, whereas protein, fat, casein percentage, casein index, and somatic cell score were considered as milk quality traits. Finally, reproductive traits such as the number of inseminations, days open, calving interval, and calving-to-first-insemination interval were evaluated. Reggiana cattle produce an average of 19 kg of milk per day with 3.7% fat and 3.4% protein content and have excellent fertility parameters. Compared with other breeds, they have slightly lower heritability for production and quality for production traits (e.g., 0.12 [0.09; 0.15] for milk yield), but similar heritability for fertility traits. Milk, protein, and fat daily yields are highly correlated but negatively correlated with the percentage of protein, fat, and casein, whereas fertility traits have an unfavorable genetic correlation with daily production traits. When considering productivity, a consistent amount of variability due to GxE was observed for all daily production traits, somatic cell count, and casein index. A modest amount of GxE was observed for fertility parameters, while the percentage of solid content showed almost no GxE effect. A similar situation occurred when considering the THI, but no GxE interaction was observed for reproduction traits. In conclusion, this study provides useful information for the implementation of accurate selection plans in this local breed, accounting for environmental plasticity measured through the consistent GxE interaction observed

    Neutrino-nucleus cross sections for oscillation experiments

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    Neutrino oscillations physics is entered in the precision era. In this context accelerator-based neutrino experiments need a reduction of systematic errors to the level of a few percent. Today one of the most important sources of systematic errors are neutrino-nucleus cross sections which in the hundreds-MeV to few-GeV energy region are known with a precision not exceeding 20%. In this article we review the present experimental and theoretical knowledge of the neutrino-nucleus interaction physics. After introducing neutrino oscillation physics and accelerator-based neutrino experiments, we overview general aspects of the neutrino-nucleus cross sections, both theoretical and experimental views. Then we focus on these quantities in different reaction channels. We start with the quasielastic and quasielastic-like cross section, putting a special emphasis on multinucleon emission channel which attracted a lot of attention in the last few years. We review the main aspects of the different microscopic models for this channel by discussing analogies and differences among them.The discussion is always driven by a comparison with the experimental data. We then consider the one pion production channel where data-theory agreement remains very unsatisfactory. We describe how to interpret pion data, then we analyze in particular the puzzle related to the impossibility of theoretical models and Monte Carlo to simultaneously describe MiniBooNE and MINERvA experimental results. Inclusive cross sections are also discussed, as well as the comparison between the νμ\nu_\mu and νe\nu_e cross sections, relevant for the CP violation experiments. The impact of the nuclear effects on the reconstruction of neutrino energy and on the determination of the neutrino oscillation parameters is reviewed. A window to the future is finally opened by discussing projects and efforts in future detectors, beams, and analysis

    Physics potential of a long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and Hyper-Kamiokande

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    39 pages, 26 figures, submitted to PTE
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