593 research outputs found

    Offshoring, employment and wages

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    This paper reviews the debate on the economic effect of the international fragmentation of production, also known as "offshoring", and provides a preliminary investigation of the impact of intermediate imported inputs on employment and wages in five European countries (Germany, Spain, France, Italy, the United Kingdom). Data are obtained from the Sectoral Innovation Database (SID) of the University of Urbino, a large database that merges statistical material from various sources (LFS; CIS; WIOD). The first part of this work provides a review of the empirical literature that discusses the economic effects of offshoring on domestic labor demand and wages. The second section of the paper presents offshoring trends and discusses the results of the econometric analysis. Results suggest that offshoring has a general negative impact on employment and wages although more careful examination reveals that high-tech offshoring has a positive effect on wages of medium- and high-skilled workers

    Torsional evaluation on different bending conditions of two Nickel Titanium Rotary Glide Path files with different alloy

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    The aim of the current study is to compare the torsional resistance of two different glidepath files, the Mtwo 10.04 and the Hyflex EDM Glide Path files 10.05, under different bending conditions

    A Bacterial Pathogen Displaying Temperature-Enhanced Virulence of the Microalga Emiliania huxleyi.

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    Emiliania huxleyi is a globally abundant microalga that plays a significant role in biogeochemical cycles. Over the next century, sea surface temperatures are predicted to increase drastically, which will likely have significant effects on the survival and ecology of E. huxleyi. In a warming ocean, this microalga may become increasingly vulnerable to pathogens, particularly those with temperature-dependent virulence. Ruegeria is a genus of Rhodobacteraceae whose population size tracks that of E. huxleyi throughout the alga's bloom-bust lifecycle. A representative of this genus, Ruegeria sp. R11, is known to cause bleaching disease in a red macroalga at elevated temperatures. To investigate if the pathogenicity of R11 extends to microalgae, it was co-cultured with several cell types of E. huxleyi near the alga's optimum (18°C), and at an elevated temperature (25°C) known to induce virulence in R11. The algal populations were monitored using flow cytometry and pulse-amplitude modulated fluorometry. Cultures of algae without bacteria remained healthy at 18°C, but lower cell counts in control cultures at 25°C indicated some stress at the elevated temperature. Both the C (coccolith-bearing) and S (scale-bearing swarming) cell types of E. huxleyi experienced a rapid decline resulting in apparent death when co-cultured with R11 at 25°C, but had no effect on N (naked) cell type at either temperature. R11 had no initial negative impact on C and S type E. huxleyi population size or health at 18°C, but caused death in older co-cultures. This differential effect of R11 on its host at 18 and 25°C suggest it is a temperature-enhanced opportunistic pathogen of E. huxleyi. We also detected caspase-like activity in dying C type cells co-cultured with R11, which suggests that programmed cell death plays a role in the death of E. huxleyi triggered by R11 - a mechanism induced by viruses (EhVs) and implicated in E. huxleyi bloom collapse. Given that E. huxleyi has recently been shown to have acquired resistance against EhVs at elevated temperature, bacterial pathogens with temperature-dependent virulence, such as R11, may become much more important in the ecology of E. huxleyi in a warming climate

    PyMod: sequence similarity searches, multiple sequence-structure alignments, and homology modeling within PyMOL

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    Background: In recent years, an exponential growing number of tools for protein sequence analysis, editing and modeling tasks have been put at the disposal of the scientific community. Despite the vast majority of these tools have been released as open source software, their deep learning curves often discourages even the most experienced users. Results: A simple and intuitive interface, PyMod, between the popular molecular graphics system PyMOL and several other tools (i.e., [PSI-] BLAST, ClustalW, MUSCLE, CEalign and MODELLER) has been developed, to show how the integration of the individual steps required for homology modeling and sequence/structure analysis within the PyMOL framework can hugely simplify these tasks. Sequence similarity searches, multiple sequence and structural alignments generation and editing, and even the possibility to merge sequence and structure alignments have been implemented in PyMod, with the aim of creating a simple, yet powerful tool for sequence and structure analysis and building of homology models. Conclusions: PyMod represents a new tool for the analysis and the manipulation of protein sequences and structures. The ease of use, integration with many sequence retrieving and alignment tools and PyMOL, one of the most used molecular visualization system, are the key features of this tool. Source code, installation instructions, video tutorials and a user's guide are freely available at the URL http://schubert.bio.uniroma1.it/pymod/index.htm

    Biological activity of ethanol extract from leaves of Rosmarinus eriocalyx

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    Aging or senescence is a complex and inevitable process, which is not only attributed to individual genetic variation but also to external factors such as environmental conditions, nutrition, alcohol, and diseases [1]. The most widely accepted theory, that have been proposed to explain aging, is the free radical theory [2]. Aging and related diseases result from accumulated oxidative damage to cell constituents and tissues caused by excessive exposure to free radicals. Antioxidants, which mediate the imbalance between intracellular antioxidant defenses and oxidative damage by reducing the reactive oxygen species (ROS) levels, are believe to be able to reduce stress-induced premature senescence or slow down replicative senescence [3]. Rosmarinus eriocalyx (Jord. & Fourr.) is an aromatic evergreen bush belonging to Lamiaceae family and endemic to Algeria, Morocco and Spain, where it is used as a condiment to flavor soup and meat and as a traditional remedy [4]. The plant volatile fraction is characterized by the monoterpene ketone camphor, whereas its ethanolic extracts are rich sources of phenolic acids and diterpenes such as rosmarinic acid, carnosic acid and carnosol that are the main responsible for the noteworthy antioxidant activity [5]. In this setting, we aimed to evaluate R. eriocalyx biological activity in order to propose the plant as an anti-aging agent. For this purpose, we determined the cytotoxic activity of polar extracts obtained from leaves, flowers, and stems of R. eriocalyx on human fibroblast and human tumor cell lines (A375, MDA-MB 231, and T98G) by MTT assay [6]. Results showed that the ethanolic extract of leaves resulted the most active against A375 human melanoma cell line (IC50 value of 17.8 µg/ml). The total phenolic content values reported for R. eriocalyx ethanolic and aqueous extracts showed slight differences and free radical scavenging activity was stronger for ethanolic extracts than aqueous ones. On this basis, we selected the R. eriocalyx ethanolic extract to determine the antioxidant activity on human fibroblast by measuring its ability to prevent oxidation in cells using a ROS fluorescent probe (DCFH-DA) [7]. Results showed a remarkable activity in preventing oxidation of cells induced by 2.2’-azobis -2-amidinopropane (ABAP). Afterwards, we tested the same extract on the H2O2-induced premature senescence in young fibroblast cells where -galactosidase (SA--gal) activity was used to measure cell senescence [8]. Preliminary data showed a reduction of H2O2 stress-induced premature senescence indicating the potential of R. eriocalyx leaf extract to be formulated as an anti-aging agent. References [1] N. Getoff. Anti-aging and aging factors in life. The role of free radicals. Radiat. Phys. Chem. 2007, 76,1577-1586. [2] D. Harman. Aging: a theory based on free radical and radiation chemistry. J. Gerontol. 1956, 11, 298-300. [3] D. Fusco, G. Colloca, M.R. Lo Monaco, M. Cesari. Effects of antioxidant supplementation on the aging process. Clin. Interv. Aging. 2007, 2, 377-387. [4] M.S. Bendeddouche, H. Benhassaini, Z. Hazem, A. Romane. Essential oil analysis and antibacterial activity of Rosmarinus tournefortii from Algeria. Nat. Prod. Commun. 2011, 6, 1511-1514. [5] H. Bendif, M. Boudjeniba, M. Djamel Miara, L. Biqiku, M. Bramucci, G. Caprioli, G. Lupidi, L. Quassinti, G. Sagratini, L.A. Vitali, S. Vittori, F. Maggi. Rosmarinus eriocalyx: An alternative to Rosmarinus officinalis as a source of antioxidant compounds. Food Chem. 2017, 218, 78-88. [6] L. Quassinti, G. Lupidi, F. Maggi, F. Papa, S. Vittori, A. Bianco, M. Bramucci . Antioxidant and antiproliferative activity of Hypericum hircinum L. subsp. majus (Aiton) N. Robson essential oil. Nat. Prod. Res. 2013, 27, 862-868. [7] K.L. Wolfe, R.H. Liu. Cellular antioxidant activity (CAA) assay for assessing antioxidants, foods, and dietary supplements. J. Agric. Food Chem. 2007, 55, 8896-8907. [8] D.J. Kurz, S. Decary, Y. Hong, J.D. Erusalimsky. Senescence-associated -galactosidase reflects an increase in lysosomal mass during replicative ageing of human endothelial cells. J. Cell Sci. 2000, 113, 3613–3622

    A small volume bioassay to assess bacterial/phytoplankton co-culture using WATER-Pulse-Amplitude-Modulated (WATER-PAM) fluorometry

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    © 2015 Journal of Visualized Experiments. Conventional methods for experimental manipulation of microalgae have employed large volumes of culture (20 ml to 5 L), so that the culture can be subsampled throughout the experiment1–7. Subsampling of large volumes can be problematic for several reasons: 1) it causes variation in the total volume and the surface area:volume ratio of the culture during the experiment; 2) pseudo-replication (i.e., replicate samples from the same treatment flask8) is often employed rather than true replicates (i.e., sampling from replicate treatments); 3) the duration of the experiment is limited by the total volume; and 4) axenic cultures or the usual bacterial microbiota are difficult to maintain during long-term experiments as contamination commonly occurs during subsampling. The use of microtiter plates enables 1 ml culture volumes to be used for each replicate, with up to 48 separate treatments within a 12.65 x 8.5 x 2.2 cm plate, thereby decreasing the experimental volume and allowing for extensive replication without subsampling any treatment. Additionally, this technique can be modified to fit a variety of experimental formats including: bacterial-algal co-cultures, algal physiology tests, and toxin screening9–11. Individual wells with an alga, bacterium and/or co-cultures can be sampled for numerous laboratory procedures including, but not limited to: WATER-Pulse-Amplitude-Modulated (WATER-PAM) fluorometry, microscopy, bacterial colony forming unit (cfu) counts and flow cytometry. The combination of the microtiter plate format and WATER-PAM fluorometry allows for multiple rapid measurements of photochemical yield and other photochemical parameters with low variability between samples, high reproducibility and avoids the many pitfalls of subsampling a carboy or conical flask over the course of an experiment

    Multicolor fluorescence technique to detect apoptotic cells in advanced coronary atherosclerotic plaques.

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    Apoptosis occurring in atherosclerotic lesions has been suggested to be involved in the evolution and the structural stability of the plaques. It is still a matter of debate whether apoptosis mainly involves vascular smooth muscle cells (vSMCs) in the fibrous tissue or inflammatory (namely foam) cells, thus preferentially affecting the cell-poor lipid core of the atherosclerotic plaques. The aim of the present investigation was to detect the presence of apoptotic cells and to estimate their percentage in a series of atherosclerotic plaques obtained either by autopsy or during surgical atherectomy. Apoptotic cells were identified on paraffinembedded sections on the basis of cell nuclear morphology after DNA staining and/or by cytochemical reactions (TUNEL assay, immunodetection of the proteolytic poly (ADP-ribose) polymerase-1 [PARP-1] fragment); biochemical procedures (identifying DNA fragmentation or PARP-1 proteolysis) were also used. Indirect immunofluorescence techniques were performed to label specific antigens for either vSMCs or macrophages (i.e., the cells which are most likely prone to apoptosis in atherosclerotic lesions): the proper selection of fluorochrome labeling allowed the simultaneous detection of the cell phenotype and the apoptotic characteristics, by multicolor fluorescence techniques. Apoptotic cells proved to be less than 5% of the whole cell population, in atherosclerotic plaque sections: this is, in fact, a too low cell fraction to be detected by widely used biochemical methods, such as agarose gel electrophoresis of low-molecular-weight DNA or Western-blot analysis of PARP-1 degradation. Most apoptotic cells were of macrophage origin, and clustered in the tunica media, near or within the lipid-rich core; only a few TUNEL-positive cells were labeled for antigens specific for vSMCs. These results confirm that, among the cell populations in atherosclerotic plaques, macrophage foam-cells are preferentially involved in apoptosis. Their death may decrease the cell number in the lipid core and generate a possibly defective apoptotic clearance: the resulting release of matrix-degrading enzymes could contribute to weakening the fibrous cap and promote the plaque rupture with the risk of acute ischemic events, while increasing the thrombogenic pultaceous pool of the plaque core

    The bacterial symbiont Phaeobacter inhibens Shapes the life history of its algal host emiliania huxleyi

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    © 2018 Bramucci, Labeeuw, Orata, Ryan, Malmstrom and Case. Marine microbes form host-associated biofilm communities that are shaped by complex interactions between bacteria and their host. The roseobacter Phaeobacter inhibens exploits both symbiotic and pathogenic niches while interacting with its microalgal host Emiliania huxleyi. During co-cultivation over extended periods with E. huxleyi, we show that P. inhibens selectively kills two host cell types, the diploid calcifying strain and the haploid flagellated strain. Meanwhile, various non-calcifying diploid strains are resistant to this pathogen or the pathogen is avirulent to this cell type. This differential pathogenesis has the potential of dramatically altering the composition of E. huxleyi blooms, which are typically dominated by the roseobacter-susceptible calcifying strain. This cell type makes calcite plates, which are an important sink in the marine carbon cycle and forms part of the marine paleobotanic record. P. inhibens kills the haploid cells, which have been proposed as critical to the survival of the algae, as they readily escape both eukaryotic predation and viral infection. Consequently, bacteria such as P. inhibens could influence E. huxleyi's life history by selective pathogenesis, thereby altering the composition of cell types within E. huxleyi populations and its bloom-bust lifestyle
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