Whither collective action? Upscaling collective actions,politics and basin management in the process of ‘legitimizing’ an informal groundwater economy

This article examines different forms and levels of collective action by aquifer users in securing access to over-allocated groundwater resources using a case study of La Loma, Úbeda (Jaén, Spain), one of the largest olive-growing areas in the world. It shows how opportunities for collective water management increase at the basin level as bargaining spaces increase but also how political rent influences the institutional designs that emerge. The article identifies an opportunity to redesign the organizational and institutional configurations by both securing access to water and strengthening collaborative spaces at the basin level.     

Study of mechanical properties of AISI 316 stainless steel processed by “selective laser melting”, following different manufacturing strategies

Considering additive manufacturing (AM) as a field of major interest, this paper is focused on the study of the mechanical properties and their variability with manufacturing orientation (anisotropy) for a metallic alloy manufactured by AM, using the technology of selective laser melting (SLM). This study has been performed on an austenitic stainless steel—AISI 316 L—used for many industrial fields as chemical, cellulose, and medical, among them. Finally, the obtained properties have been analyzed and compared, for this steel, to those properties standardized and tested for “wrought” products. In this paper, previously published results are complemented, as the mechanical tests have been performed in all the possible directions of manufacturing by SLM and not only in two main directions. High mechanical values have been obtained, especially yield strength (significantly improved, compared with wrought or cast products) while keeping high values of ductility and notch impact resistance. For widespread industrial acceptance, AM parts need to be produced to high tolerances and with well-understood mechanical properties, and the aim of this paper is to contribute to this objective.     

Multiresidue method for the determination of quinolone antibiotics in bovine raw milk by capillary electrophoresis-tandem mass spectrometry

A new analytical method based on capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) is proposed and validated for the identification and simultaneous quantification of eight quinolones for veterinary use in bovine raw milk. The studied quinolones include danofloxacin, sarafloxacin, ciprofloxacin, marbofloxacin, enrofloxacin, difloxacin, oxolinic acid, and flumequine, whose contents are regulated by the EU Council Regulation no. 2377/90 in animal edible tissues. Different parameters (i.e., separation buffer composition and electrospray conditions) were optimized in order to obtain both an adequate CE separation and a high sensitivity, using experimental design methodology to consider the interactions among the studied variables. MS/MS experiments using an ion trap as analyzer operating in the multiple reaction monitoring mode were carried out to achieve the minimum number of identification points according to the 2002/657/EC European Decision. For the quantification in bovine raw milk samples, a two-step solid-phase extraction procedure was developed using Oasis MAX and HLB cartridges without protein precipitation. Satisfactory results were obtained in terms of linearity (r2 between 0.989 and 0.992) and precision (RSD below 18%). The limits of detection and quantification (below 6 and 24 ppb, respectively) were in all cases lower than the maximum residues limits tolerated for these compounds in milk, the recoveries ranging from 81 to 110%, indicating the potential of the CZE-MS/MS for the analysis of regulated quinolone antibiotics in the food quality and safety control areas.     

Hypervelocity Jet Initiation Threshold Criteria of Nitromethane and Nitromethane Mixtures

The experimental hypervelocity jet initiation threshold criteria for neat nitromethane and homogeneous- and heterogeneous-sensitized nitromethane mixtures have been determined over a range of failure diameters, jet velocities from 2–9 mm/μs, and jet diameters in two test configurations. These criteria were used to define detonation and failure conditions in nitromethane and the nitromethane mixtures as a function of contact- and bow-shock conditions. These data were compared with data reported by others in the literature on bare solid explosives. A favorable comparison of threshold values is achieved by normalization of the criteria with the failure diameters. The effect on the initiation of the confinement proximity to the jet axis was also investigated. Experimental results have shown that high impedance boundaries near the jet axis induced conditions that allowed initiation to occur at lower jet velocities than those determined by the criteria. Tests also were performed on both homogeneous and heterogeneous nitromethane mixtures, having the same failure diameters, to determine if the same or similar jet penetration distances were required for initiation. The results, within experimental error, do not show any definitive differences in initiation conditions between the two types of mixtures.     

IFN-gamma treatment increases insulin binding and MHC class I expression in erythroleukemia cells

We have investigated if interferon-gamma (IFN-gamma) treatment of human K562 tumor cells, which upregulates the expression of MHC class I antigens (MHC-I), simultaneously would influence insulin binding. Treatment of K562 cells with recombinant human IFN-gamma for 48 h caused a significant increase of insulin binding at 37 degrees C. Recombinant human tumor necrosis factor-alpha (TNF-alpha) alone had no effect but acted synergistically with IFN-gamma, leading to a two-fold increase of insulin binding. No change in affinity, number of binding sites or cell surface expression of insulin receptors (IR) after IFN-gamma treatment could be detected. The increased insulin binding observed at 37 degrees C was not seen at 4 degrees C, suggesting alteration of insulin internalization. The dose-response curve, as well as the time curve, for the increase in insulin binding after IFN-gamma treatment correlated with enhanced cell surface expression of MHC-I antigens. However, the correlation was not absolute. Our results show that IFN-gamma treatment alone or together with TNF-alpha, can alter the insulin binding to K562 cells without changing the expression or affinity of the IR. This correlates with the effect of IFN-gamma on MHC-I expression. These results support the findings that MHC-I molecules associate and interact with the IR at the cell surface.     

Optics Design and Verification for the APEX Swedish Heterodyne Facility Instrument (SHeFI)

In this paper, we present the design and verification of the optics of the Swedish Heterodyne Facility Instrument (SHeFI) receiver installed in the Atacama Pathfinder EXperiment (APEX) telescope during spring 2008. SHeFI is located in the Nasmyth instrumentation Cabin A (NCA). The receiver has been designed to have 6 frequency channels, of which four receiver channels have been built, and characterized: 211-275 GHz (Band 1), 275-370 GHz (Band 2), 385-500 GHz (Band 3), and 1250-1390 GHz (Band T2). Bands 1, 2, and T2 are installed at the telescope and are currently in operation. The optical design is driven by the requirement of frequency independent illumination of the secondary with -12 dB edge taper for each frequency channel and the limitation (beam clearance through the Nasmyth tube and the elevation encoder) imposed by the receiver position in the NCA. This paper describes the design approach, optimization, and verification of the optical system, coupling each individual receiving beam to the common optics of the telescope.     

Plenoptic video geometry

More and more processing of visual information is nowadays done by computers, but the images captured by conventional cameras are still based on the pinhole principle inspired by our own eyes. This principle though is not necessarily the optimal image-formation principle for automated processing of visual information. Each camera samples the space of light rays according to some pattern. If we understand the structure of the space formed by the light rays passing through a volume of space, we can determine the camera, or in other words the sampling pattern of light rays, that is optimal with regard to a given task. In this work we analyze the differential structure of the space of time-varying light rays described by the plenoptic function and use this analysis to relate the rigid motion of an imaging device to the derivatives of the plenoptic function. The results can be used to define a hierarchy of camera models with respect to the structure from motion problem and formulate a linear, scene-independent estimation problem for the rigid motion of the sensor purely in terms of the captured images.     

A Higher-Order Chimera Method for Finite Volume Schemes

In this work a higher-order accurate finite volume method for the resolution of the Euler/Navier–Stokes equations using Chimera grid techniques is presented. The formulation is based on the use of Moving Least Squares approximations in order to obtain higher-order accurate reconstruction and connectivity between the overlapped grids. The accuracy and performance of the proposed methodology is demonstrated by solving different benchmark problems.