2,997 research outputs found
In situ GISAXS study of the growth of Pd on MgO(001)
The morphology of growing Pd nano-particles on MgO(001) surfaces have been
investigated in situ, during growth, by grazing incidence small angle x-ray
scattering, for different substrate temperatures. The 2D patterns obtained are
quantitatively analyzed, and the average morphological parameters (shape, size)
deduced. Above 650 K, the aggregates adopt their equilibrium shape of truncated
octahedron, and the interfacial energy is deduced.Comment: 10 pages, 1 Table, 2 Figure
spatiotemporal variability of alkalinity in the mediterranean sea
Abstract. The paper provides a basin-scale assessment of the spatiotemporal distribution of alkalinity in the Mediterranean Sea. The assessment is made by integrating the available observations into a 3-D transport–biogeochemical model. The results indicate the presence of complex spatial patterns: a marked west-to-east surface gradient of alkalinity is coupled to secondary negative gradients: (1) from marginal seas (Adriatic and Aegean Sea) to the eastern Mediterranean Sea and (2) from north to south in the western region. The west–east gradient is related to the mixing of Atlantic water entering from the Strait of Gibraltar with the high-alkaline water of the eastern sub-basins, which is correlated to the positive surface flux of evaporation minus precipitation. The north-to-south gradients are related to the terrestrial input and to the input of the Black Sea water through the Dardanelles. In the surface layers, alkalinity has a relevant seasonal cycle (up to 40 μmol kg−1) that is driven by physical processes (seasonal cycle of evaporation and vertical mixing) and, to a minor extent, by biological processes. A comparison of alkalinity vs. salinity indicates that different regions present different relationships: in regions of freshwater influence, the two quantities are negatively correlated due to riverine alkalinity input, whereas they are positively correlated in open sea areas of the Mediterranean Sea
Self-­‐ordering in solution of a novel polyamidoaminoacid with a chiral arginine side chain
Polyamidoaminoacids (PAAC) are a new class of bioinspired polymers obtained by polyaddition of selected aminoacids with N,N'-methylenebisacrylamide. Here we report some results obtained for the first such polymer, ARGO7, obtained with arginine stereoisomers. The CD spectra of the ARGO7 isomers showed an important and unexpected indication of a self-ordered pH-dependent secondary structure that was however nearly unaffected by temperature, ionic strength and denaturating agents. Theoretical modeling studies of L-ARGO7 carried out with classical Molecular Dynamical simulations showed that it assumed a folded structure with a transoid arrangement of the main chain reminiscent of the protein hairpin motif due to the intramolecular interactions. Torsion angles along the backbone showed a similar distribution at pH 6 and 14 consistent with the similarity of the CD spectra from pH 6 onwards
Intra and interspecific variation assessment in Psocoptera using near spectoscopy
Several species of Psocoptera are associated with and damage grains and other stored products, books, historical documents, and insect collections. Their small size and lack of expressive morphological variation make it a difficult group for species identification. The spectra of adult males and females of 10 psocid species from the genus Liposcelis were obtained by near infrared spectroscopy (NIRS) and analyzed. Each specimen was placed on a diffuse reflectance accessory of a NIR spectrometer to obtain the respective spectrum, using ten replicates for each species or sex. All spectra were analyzed by combined methods of multivariate analysis using the technique of crossed validation for the multivariate models. The analysis discriminated the species without significant overlapping among the species spectral patterns. The NIRS also revealed variation in the metabolomic profile of males and females; however, it is still possible to distinguish the species using only males or females or even from mixed sex samples. NIRS technique proved to be a powerful tool to discriminate species both at intra and interspecific levels based on dispersion spectral patterns of individual specimens. Keywords: Biological systems, Liposcelididae, stored product pests, Vibrational spectroscopy
Molecular Perception for Visualization and Computation: The Proxima Library
Proxima is a molecular perception library designed with a double purpose: To be used with immersive molecular viewers (thus providing any required feature not supported by third party libraries) and to be integrated in workflow managers thus providing the functionalities needed for the first steps of molecular modeling studies. It thus stands at the boundary between visualization and computation. The purpose of the present article is to provide a general introduction to the first release of Proxima, describe its most significant features, and highlight its performance by means of some case studies. The current version of Proxima is available for evaluation purposes at https://bitbucket.org/sns-smartlab/proxima/src/master/
Economic and environmental sustainability dimensions of a fashion supply chain: A quantitative model
Paper aim: The paper presents a model to assess the economic and the environmental sustainability dimensions of a fashion supply chain and tests it on a company. Originality: The gap intended to fill is the lack of models in this context having this purpose, and, in general, the necessity to develop models and metrics allowing to quantitatively assess the economic and environmental dimensions of supply chains. Research method: The fashion supply chain has been divided into five processes. Hence, an analytic model was developed by considering the total costs incurring in each process (economic evaluation), and the annual kilograms of CO2 emitted (environmental perspective). The model was then applied to a case study. Data was obtained from interviews with the management. Main findings: Results show that from the economic perspective supply impacts the most, while from the environmental one the most polluting activity is production. Implications for theory and practice: The model is easy to apply and to understand and allows to identify the activities in the supply chain where the majority of costs/emissions are generated. It is therefore expected to be useful for undertaking operational decisions aimed at decreasing the economic or environmental impact of a fashion supply chain
A model for assessing economic and environmental sustainability dimensions of a fashion supply chain and a case study
Due to the recent attention gained by sustainability issues in the context of supply chains, the aim of this study is to present a model developed under Microsoft Excelâ„¢ for the assessment of the economic and environmental dimensions of a fashion supply chain, sector that deserves particular attention being one of the most polluting in the world. The assessment of the economic dimension is made through the evaluation of the total cost incurred in each process of the supply chain, while the environmental aspect is evaluated in terms of the carbon dioxide emissions generated. Specifically, in this paper the modelling of the warehouse function is detailed. To test the effectiveness of the model a case study is carried out on a fashion company based in the North of Italy; the key results are reported in the manuscript, showing where the majority of costs and emissions are generated. Information obtained from this tool can support the company's management in their operational decisions and show where to focus their attention to enhance the economic and environmental sustainability
Early embryonic development, assisted reproductive technologies, and pluripotent stem cell biology in domestic mammals
Over many decades assisted reproductive technologies, including artificial insemination, embryo transfer, in vitro production (IVP) of embryos, cloning by somatic cell nuclear transfer (SCNT), and stem cell culture, have been developed with the aim of refining breeding strategies for improved production and health in animal husbandry. More recently, biomedical applications of these technologies, in particular, SCNT and stem cell culture, have been pursued in domestic mammals in order to create models for human disease and therapy. The following review focuses on presenting important aspects of pre-implantation development in cattle, pigs, horses, and dogs. Biological aspects and impact of assisted reproductive technologies including IVP, SCNT, and culture of pluripotent stem cells are also addressed. © 2013 Elsevier Ltd
Tricorynus rudepunctatus (PIC) (Coleoptera: Anobiidae): Diagnosis and damage
The objective of this research was to identify and study a species of Anobiidae that causes great damage and is a cause of concern as an urban pest in Brazil. This species has been found infesting wood, furniture, doors, books, insect collections, tea, dried fruits, handcrafts, and many other commodities. Inspections were done in houses and storehouses in the city of Curitiba, PR, Brazil in order to collect objects and materials that present signs of anobiid attack. The only species identified was Tricorynus rudepunctatus (Coleoptera: Anobiidae). There is only one reference to this species in the central region of Brazil. Another anobiid, the book pest Tricorynus herbarius has been recorded attacking books and historical documents and Tricorynus sp. attacking forest trees, but it was not recorded in our survey. Usually, the damage caused by T. rudepunctatus is mistaken with damage by termites; and when the insect is collected it is frequently misidentified as T. herbarius or as the cigarette beetle, Lasioderma serricorne or even as Stegobium paniceum, the drugstore beetle. Some morphological characters useful to identify T. rudepunctatus are: oval body about 2.7 mm long; dark brown with smooth hairs all over the body; head concealed under the pronotum; 10-segmented antenna with the three apical segments forming a 3-segmented loose club; elytra with two grooves at the posterior edge; fore femur with a transversal line on its anterior face; pro and mesotibia with two distinct striae; metasternum longitudinally carinate in the middle. Adults and larvae bore inside the materials, forming galleries and producing a coarse powder. Keywords: Anobiids, Insect identification, Morphological characters, Urban pest
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