115 research outputs found

    Findings Consistent with Nonselective Feeding in Tetrahymena pyriformis

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    In amoeboid cells, food particles are engulfed only after receptors on the phagocytic cell’s membrane bind to ligands on a particle’s surface. Ciliates also feed via phagocytosis but, instead of enveloping particles, some ciliates take them up through a complex, permanent, funnel-shaped, feeding apparatus. It is unclear whether receptor-ligand interactions are needed to trigger the process. If ciliates were shown to feed selectively on certain particles over others, based on the particles’ surface properties, then receptor-ligand interactions would likely play a role in phagocytosis. The literature includes few reports of such selectivity. To further investigate this issue, we chose to study feeding preference in the ciliate Tetrahymena pyriformis. We fed Tetrahymena mixtures of orange and green, fluorescent, 3 µm, polystyrene beads at two concentrations. One of the two types of beads was coated with bovine serum albumin. Authors were blinded to experimental conditions. We found no evidence of a preference for coated or uncoated beads at either concentration. We also found no trend toward the development of selective feeding as cells acquired more beads over time. Although we cannot rule out the possibility that Tetrahymena feeds selectively, we did not find convincing evidence of such selectivity when T. pyriformis is given a choice between uncoated beads and those coated with albumin. Our results failed to demonstrate a role for molecular recognition when Tetrahymena engages in phagocytosis

    Maternal depression and child human capital: a genetic instrumental variable approach

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    We here address the causal relationship between maternal depression and child human capital using UK cohort data. We exploit the conditionally-exogenous variation in mothers’ genomes in an instrumentalvariable approach, and describe the conditions under which mother’s genetic variants can be used as valid instruments. An additional episode of maternal depression between the child’s birth up to age nine reduces both their cognitive and non-cognitive skills by 20 to 45% of a SD throughout adolescence. Our results are robust to a battery of sensitivity tests addressing, among others, concerns about pleiotropy and the maternal transmission of genes to her child

    Combined Untargeted and Targeted Fingerprinting by Comprehensive Two-Dimensional Gas Chromatography to Track Compositional Changes on Hazelnut Primary Metabolome during Roasting

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    This study focuses on the detectable metabolome of high-quality raw hazelnuts (Cory- lus avellana L.) and on its changes after dry-roasting. Informative fingerprinting was obtained by comprehensive two-dimensional gas chromatography with fast-scanning quadrupole mass spectrom- etry (GC×GC-qMS) combined with dedicated data processing. In particular, combined untargeted and targeted (UT) fingerprinting, based on pattern recognition by template matching, is applied to chromatograms from raw and roasted samples of Tonda Gentile Trilobata and Anakliuri hazelnuts harvested in Italy and Georgia. Lab-scale roasting was designed to develop a desirable organoleptic profile matching industrial standards. Results, based on 430 peak features, reveal that phenotype expression is markedly correlated to cultivar and pedoclimatic conditions. Discriminant components between cultivars are amino acids (valine, alanine, glycine, and proline); organic acids (citric, aspartic, malic, gluconic, threonic, and 4-aminobutanoic acids); and sugars and polyols (maltose, xylulose, xylitol, turanose, mannitol, scyllo-inositol, and pinitol). Of these, alanine, glycine, and proline have a high informational role as precursors of 2-acetyl- and 2-propionylpyrroline, two key-aroma com- pounds of roasted hazelnuts. Roasting has a decisive impact on metabolite patterns—it caused a marked decrease (−90%) of alanine, proline, leucine and valine, and aspartic and pyroglutamic acid and a −50% reduction of saccharose and galactose

    Soil communities: who responds and how quickly to a change in agricultural system?

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    The use of conservation and sustainable practices could restore the abundance and richness of soil organisms in agroecosystems. Fitting in this context, this study aimed to highlight whether and how different soil living communities reacted to the conversion from an integrated to an organic orchard. The metataxonomic approach for fungi and bacteria and the determination of biological forms of diatoms and microarthropods were applied. Soil analyses were carried out in order to evaluate the effect of soil chemical features on four major soil living communities. Our results showed that the different taxa reacted with different speeds to the management changes. Fungi responded quickly to the changes, suggesting that modification in agricultural practices had a greater impact on fungal communities. Bacteria and microarthropods were more affected by abiotic parameters and less by the management. The diatom composition seemed to be affected by seasonality but the highest H’ (Shannon index) value was measured in the organic system. Fungi, but also diatoms, seemed to be promising for monitoring changes in the soil since they were sensitive to both the soil features and the anthropic impact. Our study showed that soil biodiversity could be affected by the conversion to sustainable management practices from the early years of an orchard onwards. Therefore, better ecological orchard management may strengthen soil sustainability and resilience in historically agricultural region

    Soil communities: Who responds and how quickly to a change in agricultural system?

    Get PDF
    The use of conservation and sustainable practices could restore the abundance and richness of soil organisms in agroecosystems. Fitting in this context, this study aimed to highlight whether and how different soil living communities reacted to the conversion from an integrated to an organic orchard. The metataxonomic approach for fungi and bacteria and the determination of biological forms of diatoms and microarthropods were applied. Soil analyses were carried out in order to evaluate the effect of soil chemical features on four major soil living communities. Our results showed that the different taxa reacted with different speeds to the management changes. Fungi responded quickly to the changes, suggesting that modification in agricultural practices had a greater impact on fungal communities. Bacteria and microarthropods were more affected by abiotic parameters and less by the management. The diatom composition seemed to be affected by seasonality but the highest H’ (Shannon index) value was measured in the organic system. Fungi, but also diatoms, seemed to be promising for monitoring changes in the soil since they were sensitive to both the soil features and the anthropic impact. Our study showed that soil biodiversity could be affected by the conversion to sustainable management practices from the early years of an orchard onwards. Therefore, better ecological orchard management may strengthen soil sustainability and resilience in historically agricultural regions

    Agronomical valorization of eluates from the industrial production of microorganisms: Chemical, microbiological, and ecotoxicological assessment of a novel putative biostimulant

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    Plant Biostimulants (BSs) are a valid supplement to be considered for the integration of conventional fertilization practices. Research in the BS field keeps providing alternative products of various origin, which can be employed in organic and conventional agriculture. In this study, we investigated the biostimulant activity of the eluate obtained as a by-product from the industrial production of lactic acid bacteria on bare agricultural soil. Eluates utilization is in line with the circular economy principle, creating economical value for an industrial waste product. The research focused on the study of physical, chemical, biochemical, and microbiological changes occurring in agricultural soil treated with the biowaste eluate, applied at three different dosages. The final aim was to demonstrate if, and to what extent, the application of the eluate improved soil quality parameters and enhanced the presence of beneficial soil-borne microbial communities. Results indicate that a single application at the two lower dosages does not have a pronounced effect on the soil chemical parameters tested, and neither on the biochemical proprieties. Only the higher dosage applied reported an improvement in the enzymatic activities of β-glucosidase and urease and in the chemical composition, showing a higher content of total, nitric and ammonia N, total K, and higher humification rate. On the other hand, microbial communities were strongly influenced at all dosages, showing a decrease in the bacterial biodiversity and an increase in the fungal biodiversity. Bioinformatic analysis revealed that some Operative Taxonomic Units (OTUs) promoted by the eluate application, belong to known plant growth promoting microbes. Some other OTUs, negatively influenced were attributed to known plant pathogens, mainly Fusarium spp. Finally, the ecotoxicological parameters were also determined and allowed to establish that no toxic effect occurred upon eluate applications onto soil

    Albarella future – zero carbon emission

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    Climate warming is setting requirements on research also in the agronomic and forest fields. The soil and vegetation are available as carbon sinks. Ecosystems under high exploitation lost part of their carbon. It is possible to recover this carbon from the air with natural processes and to return it to the land. Besides, global warming requires a change in mentality that moves into the replacement of fossil fuels with other energy sources. In this perspective, the island of Albarella, with its environment and economic activities, represents an attractive miniature model of the planet Earth. For this design, we estimated (Vensim simulation) the emissions and storage of CO2 equivalent of the whole island. Then, with the idea of acting on natural ecosystems to make them more active in carbon storage, we analyzed two vegetation series from the forest to the sea, one located in the nearby natural reserve of Porto Caleri, and one on the island of Albarella. The investigation concerns the soil carbon storage and the quality and quantity of populations of arthropods, bacteria, and fungi as well. The biodiversity of artificial environments resulted in higher than that of natural habitats, opening a debate. Acting in different ways on the substitution of fuels, we obtained scenarios with decreasing emissions, from consumerist without substitution of fuels, realistic with 15% of replacement by solar energy, and sustainable with zero use of fossil energy and all the island electricity produced through photovoltaic panels

    Heat Stress During the Transition Period is Associated with Impaired Production, Reproduction, and Survival in Dairy Cows

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    The objectives of this retrospective cohort study were to determine the association of heat stress exposure during the transition period with production, health, reproduction, and survival during the first 90 days postpartum in dairy cows. A total of 5,722 Holstein cows (2,324 heifers and 3,397 cows) were categorized into environmental condition (EC) groups based on average temperature humidity index (THI) exposure as thermoneutral (TN) or heat stress (HS) during the pre (Pre) and early postpartum (Post) periods into TN-TN, TN-HS, HS-TN, and HS-HS. In heifers, exposure to HS during the Pre, Post, or Pre and Post was associated with a 3.7-lb/d reduction in milk yield compared with TN-TN. Postpartum HS was associated with increases of 4.4-percentage points in incidence of retained placenta, 18.1-percentage points in incidence of metritis, and 2.0-percentage points in incidence of mastitis, and a reduction in 5.3-percentage points in pregnancy at first AI, and an increase in 4.5-percentage points in pregnancy loss compared with Post TN. In cows, exposure to HS during the Pre, Post, or Pre and Post was associated with a 5.3-lb/d reduction in milk yield when compared with TN-TN. Post HS was associated with an increased incidence of retained placenta of 5.8-percentage points within Pre HS cows, whereas no difference was found within Pre TN cows. Metritis was increased by 6.3-percentage points in Post HS cows. For pregnancy per AI, Post HS was associated with reduced pregnancy of 10.6-percentage points within Pre TN cows, whereas no difference was found within Pre HS cows. Removal from the herd increased in cows exposed to HS during the Pre or Post, or Pre and Post. These data suggest that early postpartum HS is associated with performance losses to a greater extent than prepartum HS and that heifers and cows are vulnerable to losses associated with exposure to HS during the transition period

    A Standardized Morpho-Functional Classification of the Planet’s Humipedons

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    It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morphofunctional classification of humipedons (roughly the top 30–40 cm of soil: organic and organomineral surface horizons) would allow for a better understanding of the functioning of the soil ecosystem. This paper provides the founding principles of the classification of humipedon into humus systems and forms. With the recognition of a few diagnostic horizons, all humus systems can be determined. The humus forms that make up these humus systems are revealed by measuring the thicknesses of the diagnostic horizons. In the final part of the article, several figures represent the screenshots of a mobile phone or tablet application that allows for a fast recall of the diagnostic elements of the classification in the field. The article attempts to promote a standardized classification of humipedons for a global and shared management of soil at planet level
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