433 research outputs found

    A Keyword, Taxonomy and Cartographic Research Review of Sustainability Concepts for Production Scheduling in Manufacturing Systems

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    The concept of sustainability is defined as composed of three pillars: social, environmental, and economic. Social sustainability implies a commitment to equity in terms of several “interrelated and mutually supportive” principles of a “sustainable society”; this concept includes attitude change, the Earth’s vitality and diversity conservation, and a global alliance to achieve sustainability. The social and environmental aspects of sustainability are related in the way sustainability indicators are related to “quality of life” and “ecological sustainability”. The increasing interest in green and sustainable products and production has influenced research interests regarding sustainable scheduling problems in manufacturing systems. This study is aimed both at reducing pollutant emissions and increasing production efficiency: this topic is known as Green Scheduling. Existing literature research reviews on Green Scheduling Problems have pointed out both theoretical and practical aspects of this topic. The proposed work is a critical review of the scientific literature with a three-pronged approach based on keywords, taxonomy analysis, and research mapping. Specific research questions have been proposed to highlight the benefits and related objectives of this review: to discover the most widely used methodologies for solving SPGs in manufacturing and identify interesting development models, as well as the least studied domains and algorithms. The literature was analysed in order to define a map of the main research fields on SPG, highlight mainstream SPG research, propose an efficient view of emerging research areas, propose a taxonomy of SPG by collecting multiple keywords into semantic clusters, and analyse the literature according to a semantic knowledge approach. At the same time, GSP researchers are provided with an efficient view of emerging research areas, allowing them to avoid missing key research areas and focus on emerging ones

    Age-related changes of monoaminooxidases in rat cerebellar cortex

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    Age-related changes of the monoaminoxidases, evaluated by enzymatic staining, quantitative analysis of images, biochemical assay and statistical analysis of data were studied in cerebellar cortex of young (3-month-old) and aged (26- month-old) male Sprague-Dawley rats. The enzymatic staining shows the presence of monoamino-oxidases within the molecular and granular layers as well as within the Purkinje neurons of the cerebellum of young and aged animals. In molecular layer, and in Purkinje neurons the levels of monoaminooxidases were strongly increased in old rats. The granular layer showed, on the contrary, an age-dependent loss of enzymatic staining. These morphological findings were confirmed by biochemical results. The possibility that age-related changes in monoaminooxidase levels may be due to impaired energy production mechanisms and/or represent the consequence of reduced energetic needs is discussed

    Experimental evidence of antiproton reflection by a solid surface

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    We report here experimental evidence of the reflection of a large fraction of a beam of low energy antiprotons by an aluminum wall. This derives from the analysis of a set of annihilations of antiprotons that come to rest in rarefied helium gas after hitting the end wall of the apparatus. A Monte Carlo simulation of the antiproton path in aluminum indicates that the observed reflection occurs primarily via a multiple Rutherford-style scattering on Al nuclei, at least in the energy range 1-10 keV where the phenomenon is most visible in the analyzed data. These results contradict the common belief according to which the interactions between matter and antimatter are dominated by the reciprocally destructive phenomenon of annihilation.Comment: 5 pages with 5 figure

    Optical Channeling of Low Energy Antiprotons in Thin Crystal Targets

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    A relevant aspect of the interactions between charged fermions and crystal targets is coherence, which can exist at both classical and quantum levels. In the case of antiprotons crossing crystal targets, there are theories and measurements of classical-level coherence effects, in particular, channeling effects. For the present study, we assume the existence of a low-energy regime where the electrostatic interactions between an antiproton and the crystal atoms lead to a local loss in the beam flux as their leading effect. We expect this assumption to be well-justified for antiproton (p over bar ) energies below 100 eV, with a progressive transition to a standard "Rutherford regime" in the energy range 100-1000 eV. Under these conditions, the target can be treated as an optical absorber with a periodical structure, which can be simplified by considering a multi-layer planar structure only. As in standard optics, wave absorption is accompanied by interference and diffraction. Assuming sub-nanometer ranges for the relevant parameters and a realistic angular spread for the antiproton beam, we find narrow-angle focusing effects that reproduce the classical channeling effect at a qualitative level. We also find that diffraction dominates over interference, although this may strongly depend on the target details

    Gremlin is a novel agonist of the major pro-angiogenic receptor VEGFR2

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    The bone morphogenic protein antagonist gremlin is expressed during embryonic development and under different pathologic conditions, including cancer. Gremlin is a proangiogenic protein belonging to the cystine-knot superfamily that includes transforming growth factor-β proteins and the angiogenic vascular endothelial growth factors (VEGFs). Here, we demonstrate that gremlin binds VEGF receptor-2 (VEGFR2), the main transducer of VEGF-mediated angiogenic signals, in a bone morphogenic protein-independent manner. Similar to VEGF-A, gremlin activates VEGFR2 in endothelial cells, leading to VEGFR2-dependent angiogenic responses in vitro and in vivo. Gremlin thus represents a novel proangiogenic VEGFR2 agonist distinct from the VEGF family ligands with implications in vascular development, angiogenesis-dependent diseases, and tumor neovascularization

    A hydrogen beam to characterize the ASACUSA antihydrogen hyperfine spectrometer

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    The antihydrogen programme of the ASACUSA collaboration at the antiproton decelerator of CERN focuses on Rabi-type measurements of the ground-state hyperfine splitting of antihydrogen for a test of the combined Charge-Parity-Time symmetry. The spectroscopy apparatus consists of a microwave cavity to drive hyperfine transitions and a superconducting sextupole magnet for quantum state analysis via Stern-Gerlach separation. However, the small production rates of antihydrogen forestall comprehensive performance studies on the spectroscopy apparatus. For this purpose a hydrogen source and detector have been developed which in conjunction with ASACUSA's hyperfine spectroscopy equipment form a complete Rabi experiment. We report on the formation of a cooled, polarized, and time modulated beam of atomic hydrogen and its detection using a quadrupole mass spectrometer and a lock-in amplification scheme. In addition key features of ASACUSA's hyperfine spectroscopy apparatus are discussed.

    Nanoliter contact angle probes tumor angiogenic ligand-receptor protein interactions

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    Any molecular recognition reaction supported by a solid-phase drives a specific change of the solid-solution interfacial tension. Sessile Contact Angle (CA) experiments can be readily used to track this thermodynamic parameter, prompting this well-known technique to be reinvented as an alternative, easy-access and label-free way to probe and study molecular recognition events. Here we deploy this technique, renamed for this application CONAMORE (CONtact Angle MOlecular REcognition), to study the interaction of the tumor-derived pro-angiogenic vascular endothelial growth factor-A (VEGF-A) with the extracellular domain of its receptor VEGFR2. We show that CONAMORE recognizes the high affinity binding of VEGF-A at nanomolar concentrations to surface-immobilized VEGFR2 regardless of the presence of a ten folds excess of a non specific interacting protein, and that it further proofs its specificity and reliability on competitive binding experiments involving neutralizing anti-VEGF-A antibodies. Finally, CONAMORE shows the outstanding capability to detect the specific interaction between VEGFR2 and low molecular weight ligands, such as Cyclo-VEGI, a VEGFR2 antagonist cyclo-peptide, that weights about 2 kDa

    Differences in the Volatile Profile of Apple Cider Fermented with Schizosaccharomyces pombe and Schizosaccharomyces japonicus

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    In this study, two strains of Schizosaccharomyces pombe (NCAIM Y01474(T) and SBPS) and two strains of Schizosaccharomyces japonicus (DBVPG 6274(T), M23B) were investigated for their capacity to ferment apple juice and influence the volatile compounds of cider compared to Saccharomyces cerevisiae EC1118. The ethanol tolerance and deacidification capacity of Schizosaccharomyces yeasts could make them potential substitutes for the commonly used S. cerevisiae starter cultures. Despite different time courses (10-30 d), all strains could complete the fermentation process, and Schizosaccharomyces strains reduced the concentration of malic acid in the apple juice. Results indicated that each yeast exerted a distinctive impact on the volatile profile of the apple cider, giving final products separated using a principal component analysis. The volatile composition of the cider exhibited significant differences in the concentration of alcohols, esters, and fatty acids. Particularly, the flocculant strain S. japonicus M23B increased the levels of ethyl acetate (315.44 +/- 73.07 mg/L), isoamyl acetate (5.99 +/- 0.13 mg/L), and isoamyl alcohol (24.77 +/- 15.19 mg/L), while DBVPG 6274(T) incremented the levels of phenyl ethyl alcohol and methionol up to 6.19 +/- 0.51 mg/L and 3.72 +/- 0.71 mg/L, respectively. A large production of terpenes and ethyl esters (e.g., ethyl octanoate) was detected in the cider fermented by S. cerevisiae EC1118. This study demonstrates, for the first time, the possible application of S. japonicus in cider-making to provide products with distinctive aromatic notes"
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