Use of technology radiation as a method of reducing the microorganism and conservation postharvest of caja during storage

The caja fruit (Spondias spp.) are among the species considered exotic presents excellent view of economic exploitation to the Northeast of Brazil. However, contamination by microorganisms is a major factor in postharvest losses of fruits and other cultivated in Brazilian territory. Use of ionizing radiation aiming to reduce the use of pesticide products in pest control and microorganisms phytopathological and maintaining the quality of agricultural products has been studied by several researchers of postharvest fruit. This technology meets the requirements of food safety imposed by the various organs of public health. In order to evaluate the action of ionizing radiation on agents phytopathological and the effects on the quality of postharvest of caja fruits when stored under temperature of shelf, the experiment was conducted with application of doses 1.0 and 2.0 kGy, dose zero as fruit control, and storage under temperature of 23°C for twelve days. Control fruit had higher contamination by microorganisms phytopathological throughout the storage period. Analysis of total soluble solids, total titratable acidity, hydrogen potential, soluble solids/titratable acidity ratio, ascorbic acid and color of the flesh have suffered minor variations between the different doses studied.Keywords: Conservation; caja fruit; gamma radiation; postharvest storage; microorganism spoilage

Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution

The larger number of models of asteroid shapes and their rotational states derived by the lightcurve inversion give us better insight into both the nature of individual objects and the whole asteroid population. With a larger statistical sample we can study the physical properties of asteroid populations, such as main-belt asteroids or individual asteroid families, in more detail. Shape models can also be used in combination with other types of observational data (IR, adaptive optics images, stellar occultations), e.g., to determine sizes and thermal properties. We use all available photometric data of asteroids to derive their physical models by the lightcurve inversion method and compare the observed pole latitude distributions of all asteroids with known convex shape models with the simulated pole latitude distributions. We used classical dense photometric lightcurves from several sources and sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff, Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the lightcurve inversion method to determine asteroid convex models and their rotational states. We also extended a simple dynamical model for the spin evolution of asteroids used in our previous paper. We present 119 new asteroid models derived from combined dense and sparse-in-time photometry. We discuss the reliability of asteroid shape models derived only from Catalina Sky Survey data (IAU code 703) and present 20 such models. By using different values for a scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in the dynamical model for the spin evolution and by comparing synthetics and observed pole-latitude distributions, we were able to constrain the typical values of the cYORP parameter as between 0.05 and 0.6.Comment: Accepted for publication in A&A, January 15, 201

Antimicrobial resistance (AMR) nanomachines: mechanisms for fluoroquinolone and glycopeptide recognition, efflux and/or deactivation

In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics—the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins. Expression of efflux systems is regulated by GntR-like (S. aureus NorG), MarR-like (MgrA, MepR) regulators or a two-component signal transduction system (TCS) (S. aureus ArlSR). Resistance to the glycopeptide antibiotic teicoplanin occurs via efflux regulated by the TcaR regulator in S. aureus. Resistance to vancomycin occurs through modification of the D-Ala-D-Ala target in the cell wall peptidoglycan and removal of high affinity precursors, or by target protection via cell wall thickening. Of the six Van resistance types (VanA-E, VanG), the VanA resistance type is considered in this review, including its regulation by the VanSR TCS. We describe the recent application of biophysical approaches such as the hydrodynamic technique of analytical ultracentrifugation and circular dichroism spectroscopy to identify the possible molecular effector of the VanS receptor that activates expression of the Van resistance genes; both approaches demonstrated that vancomycin interacts with VanS, suggesting that vancomycin itself (or vancomycin with an accessory factor) may be an effector of vancomycin resistance. With 16 and 19 proteins or protein complexes involved in fluoroquinolone and glycopeptide resistances, respectively, and the complexities of bacterial sensing mechanisms that trigger and regulate a wide variety of possible resistance mechanisms, we propose that these antimicrobial resistance mechanisms might be considered complex ‘nanomachines’ that drive survival of bacterial cells in antibiotic environments

Mechanical behavior of honeycomb lattices manufactured by investment casting for scaffolding applications

Lightweight metallic lattices in the form of honeycombs are long known to exhibit a good mechanical strength/weight relation, given their geometry and relative density, in comparison with bulk materials. Due to the current developments in additive manufacturing techniques, the production of honeycombs by investment casting is now easier and may be a competitive route when compared to welding and gluing of sheet metal. This study explores the importance of the manufacturing design when producing honeycombs by investment casting. It is shown by numerical simulation and experimental procedures that mold filling in directions where horizontal ribs are present may induce defects such as interdendritic porosities. These defects have a relevant role in the elastic domain of the lattices, decreasing the apparent Young's modulus and the plastic collapse stress. In terms of energy absorption, it is shown that these porosities have no significant effect due to the fragile fracture of both casting directions.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the grant PD/BD/114096/2015, correspondent to the iRail Innovation in Railway Systems and Technologies Doctoral Programme and supported by the FCT - Fundacao para a Ciencia e Tecnologia.info:eu-repo/semantics/publishedVersio