563 research outputs found

    Atomic Force Microscopy - Laser Scanning Confocal Microscopy imaging protocol for copepod fecal pellets

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    Within the marine carbon and nitrogen biogeochemical cycles, fecal pellets produced by pelagic and benthic copepods are important microbial activity hotspots as particle substrate for bacteria colonization and as sources of particulate and dissolved organic C and N. We developed a protocol combining Atomic Force Microscopy (AFM) and Laser Scanning Confocal Microscopy (LSCM) to study the peritrophic membrane structure and associated bacteria of fecal pellets produced by a benthic copepod, Paramphiascella fulvofasciata. AFM imaging revealed a fibrillar network structure of the peritrophic membrane, 0.7-5.9 nm thick similar to marine polysaccharides and a-chitin. Bacterial cell volume range was 0.006-0.117 µm3 in liquid. LSCM imaging showed a 3D-heterogeneous microenvironment. This protocol would allow high-resolution interrogation of structural changes and bacterial dynamics within the copepod fecal pellets and other heterogeneous particles such marine snow under environmental conditions

    Assembling large, complex environmental metagenomes

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    The large volumes of sequencing data required to sample complex environments deeply pose new challenges to sequence analysis approaches. De novo metagenomic assembly effectively reduces the total amount of data to be analyzed but requires significant computational resources. We apply two pre-assembly filtering approaches, digital normalization and partitioning, to make large metagenome assemblies more comput\ ationaly tractable. Using a human gut mock community dataset, we demonstrate that these methods result in assemblies nearly identical to assemblies from unprocessed data. We then assemble two large soil metagenomes from matched Iowa corn and native prairie soils. The predicted functional content and phylogenetic origin of the assembled contigs indicate significant taxonomic differences despite similar function. The assembly strategies presented are generic and can be extended to any metagenome; full source code is freely available under a BSD license.Comment: Includes supporting informatio

    Naturwall: active timber wall for renovation of existent buildings

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    The renovation of old buildings is actually the challenge to cope with increased effort in order to reduce climate global change, channeling more investment and awareness in this sense, defining more experimentations and find innovative solutions. The difficulty of carrying out an intervention on the existing buildings necessarily arise from the lack of information on the existing structure and the lack of coordinated processes between the multidisciplinary skills involved, as well as a difficulty to optimize the process that would make it even more competitive on the renovation work instead on the new construction. Naturwall is an innovative energy saving system for existent buildings by using wood in multifunctional components able to mitigate the environmental effort in building management. The project meant to introduce an industrialized design method in the renovation of existing build environment that highlights opportunities gave by "off site" production and parametric design approach, without neglecting the aesthetical values and the possibility to change the architectural image of residential and non residential constructions. The project aims to create a representative model of solution that will be promoted in Italy and widespread in other similar contex

    shape to color associations in non synesthetes evidence for emotional mediation

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    4 Shape Features: Curviness: Curved, angular Symmetry: Asymmetric, symmetric Closure: Open, intersecting-once, intersecting>1 # of Line-Segments: 2, 3, 8 line-segments 8 Hues: Red, Yellow, Green, Blue, Orange, Chartreuse, Cyan, Purple 4 Saturation/Lightness levels ("cuts"): Saturated, Light, Muted, Dark + 5 Achromatic Colors: White, Black, Light, Medium, & Dark Gray 1a 1c 2a 2c 3a 3c 4a 4c 5a 5c 6

    Heat Treated NiP–SiC Composite Coatings: Elaboration and Tribocorrosion Behaviour in NaCl Solution

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    Tribocorrosion behaviour of heat-treated NiP and NiP–SiC composite coatings was investigated in a 0.6 M NaCl solution. The tribocorrosion tests were performed in a linear sliding tribometer with an electrochemical cell interface. It was analyzed the influence of SiC particles dispersion in the NiP matrix on current density developed, on coefficient of friction and on wear volume loss. The results showed that NiP–SiC composite coatings had a lower wear volume loss compared to NiP coatings. However, the incorporation of SiC particles into the metallic matrix affects the current density developed by the system during the tribocorrosion test. It was verified that not only the volume of co-deposited particles (SiC vol.%) but also the number of SiC particles per coating area unit (and consequently the SiC particles size) have made influence on the tribocorrosion behaviour of NiP–SiC composite coatings

    Short communication: Effects of summer rainfall variations on sheep body state and farming sustainability in sub-Mediterranean pastoral systems

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    In sub-Mediterranean climate the grassland aboveground phytomass production peaks in late spring and drops in summer, when the decrease of the pasture feed value may lead to the worsening of the animal welfare. Our goal was to define the summer rainfall values leading to a decrease of semi-extensive farming system sustainability in sub-Mediterranean regions. Summer rainfall variations reflect in the aboveground phytomass production and on the sheep body state. Differences of body condition score (BCS) among years were significant in late summer, which is the mating period for sheep. In the driest year the BCS of end August drops down to 2.1, largely below the value considered sufficient to ensure the animal breeding/milking performances (2.5). Reduction of summer rainfall greater than 15–20% compared to the normal average value (thus less than expected by the scenario of climate change) might be detrimental for semi-extensive rearing sustainability in sub-Mediterranean climate

    Follicular development, plasma Inhibin-A and Estradiol-17-beta concentrations in Buffalo cows during different treatment schedules for MOET programs

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    Buffalo cows were submitted to three superovulatory treatments. T1 (n = 7): PRID for 10 days (d0-d9) plus decreasing doses of 500 IU FSH/LH (12 h-intervals d7‑d10); T2 (n = 8): PRID for 11 d (d0-d10) plus 2000 IU PMSG at d7; T3 (n = 9): PRID for 11 d plus 2000 IU PMSG at d7 and decreasing doses of 175 IU FSH/LH (12 h-intervals d10‑ d11). Overall plasma inhibin‑A (In-A) concentrations correlated with large follicles (LF, diameter >6mm, R=0.83, P10 mm at d12- 13 (T1=5.0+/-1.4, T2=1.2+/-0.9, T3=8.3+/-2.3). In-A concentrations significantly rised at d11-13 of T1 and T3. In-A seems a good indicator of the follicular development during superovulation in buffalo cows, while E2 is not. Furthermore T3 was followed by better ovarian follicular responses

    Hybrid stars with sequential phase transitions: the emergence of the g2_2 mode

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    Neutron stars are the densest objects in the Universe, with M1.4MM \sim 1.4 M_{\odot} and R12R \sim 12 km, and the equation of state associated to their internal composition is still unknown. The extreme conditions to which matter is subjected inside neutron stars could lead to a phase transition in their inner cores, giving rise to a hybrid compact object. The observation of 2M2M_{\odot} binary pulsars (PSR~J1614-2230, PSR~J0343++0432 and PSR~J0740++6620) strongly constraints theoretical models of the equation of state. Moreover, the detection of gravitational waves emitted during the binary neutron star merger, GW170817, and its electromagnetic counterpart, GRB170817A, impose additional constraints on the tidal deformability. In this work, we investigate hybrid stars with sequential phase transitions hadron-quark-quark in their cores. We assume that both phase transitions are sharp and analyse the rapid and slow phase conversion scenarios. For the outer core, we use modern hadronic equations of state. For the inner core we employ the constant speed of sound parametrization for quark matter. We analyze more than 3000 hybrid equations of state, taking into account the recent observational constraints from neutron stars. The effects of hadron-quark-quark phase transitions on the normal oscillation modes ff and gg, are studied under the Cowling relativistic approximation. Our results show that, in the slow conversion regime, a second quark-quark phase transition gives rise to a new g2g_2~mode. We discuss the observational implications of our results associated to the gravitational waves detection and the possibility of detecting hints of sequential phase transitions and the associated g2g_2~mode.Comment: 24 pages, 9 figure

    New perspectives in cancer biology from a study of canonical and non-canonical functions of base excision repair proteins with a focus on early steps

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    Alterations of DNA repair enzymes and consequential triggering of aberrant DNA damage response (DDR) pathways are thought to play a pivotal role in genomic instabilities associated with cancer development, and are further thought to be important predictive biomarkers for therapy using the synthetic lethality paradigm. However, novel unpredicted perspectives are emerging from the identification of several non-canonical roles of DNA repair enzymes, particularly in gene expression regulation, by different molecular mechanisms, such as (i) non-coding RNA regulation of tumour suppressors, (ii) epigenetic and transcriptional regulation of genes involved in genotoxic responses and (iii) paracrine effects of secreted DNA repair enzymes triggering the cell senescence phenotype. The base excision repair (BER) pathway, canonically involved in the repair of non-distorting DNA lesions generated by oxidative stress, ionising radiation, alkylation damage and spontaneous or enzymatic deamination of nucleotide bases, represents a paradigm for the multifaceted roles of complex DDR in human cells. This review will focus on what is known about the canonical and non-canonical functions of BER enzymes related to cancer development, highlighting novel opportunities to understand the biology of cancer and representing future perspectives for designing new anticancer strategies. We will specifically focus on APE1 as an example of a pleiotropic and multifunctional BER protein

    Susceptibility to Exposure to Heterocyclic Amines from Cooked Food: Role of UDP-glucuronosyltransferases

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    A number of carcinogenic heterocyclic amines (PhIP, MeIQx, and DiMeIQx) are produced from the condensation of creatinine, hexoses and amino acids during the cooking of meat (1). There are many variables that impact the production and subsequent ingestion of these compounds in our diet. Temperature, type of meat product, cooking method, doneness, and other factors affect the quantity of these carcinogens consumed by humans. Estimates of ingestion of these carcinogens are 1-20 ng/kg body weight per day (2). Human case control studies that correlate meat consumption from well-done cooking practices with cancer incidence indicate excess tumors for breast, colon, stomach, esophagus, and possibly prostate (3-5)
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