Greater Resistencia Study Case: Greenfield and Increased Densification

. This paper focuses on one of the relevant issues of the phenomena of urban expansion and densification, i.e. the lack of planning of public greenfields. At the regional level, since 2001, Resistencia City Council has been promoting a growth in height by increasing built-up areas in central districts that have complete infrastructure, through the implementation of the Ordinance 5403/01 - high density. On the other hand, in the last 10 years the population growth of the city (16%) has been followed by an increase in the supply of open space per inhabitant (85%). However, this increase is not reflected in the inner city areas, where the higher population density is located. This paper aims to analyze and relate the results arising, so far, from the densification of central areas and its relationship with the availability of open space in central districts of Greater Resistencia City

NONLINEAR ANALYSIS OF BRITTLE MATERIALS

The problem of the evaluation of the nonlinear response of damaged structures is considered. In order to circumvent the numerical difficulties which can affect standard numerical strategies because of the high sensitivity of the stress response to small changes of displacements, a specific implementation of the standard path–following procedure is presented. The approach is based on a parametrization of the equilibrium curve which takes into account also the variables used in the modelling of the damage process. Two damage models, an isotropic one and an orthotropic one, are implemented in order to verify the numerical procedure in the analysis of 2D continua subjected to plane stress condition

NONLINEAR ANALYSIS OF BRITTLE MATERIALS

The problem of the evaluation of the nonlinear response of damaged structures is considered. In order to circumvent the numerical difficulties which can affect standard numerical strategies because of the high sensitivity of the stress response to small changes of displacements, a specific implementation of the standard path–following procedure is presented. The approach is based on a parametrization of the equilibrium curve which takes into account also the variables used in the modelling of the damage process. Two damage models, an isotropic one and an orthotropic one, are implemented in order to verify the numerical procedure in the analysis of 2D continua subjected to plane stress condition

Exploration of Microbial Communities Using the Thermo Scientific Varioskan LUX Multimode Reader and the Invitrogen EVOS FL Cell Imaging System

Non peer reviewe

Urban geochemistry and potential human health risks in the Metropolitan Area of Buenos Aires : PAHs and PCBs in soil, street dust, and bulk deposition

Soil, street dust, and bulk deposition (dry and wet deposition) were collected in the Metropolitan Area of Buenos Aires (MABA), Argentina, to assess the polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) pollution and the potential risks to human health. Compared with other countries, the mean concentration of PAHs and PCBs in surface soils, street dust and bulk deposition of MABA were at a low or moderate level. Average PAHs and PCBs concentrations in bulk deposition (5.7 ± 5.1 and 0.41 ± 0.25 µg g−1, respectively) were five and ten times higher than those of soil (1.08 ± 0.98 and 0.02 ± 0.01 µg g−1) and street dust (1.2 ± 0.95 and 0.04 ± 0.03 µg g−1), respectively. Different compositional profiles, observed in the three matrices for both groups of contaminants, could be attributed to dissimilar source contribution, partition processes between gas and particulate phases, and transformation. The most contaminated bulk deposition presented higher values for cancer and non-cancer risks relative to soil and street dust. In all matrices, non-carcinogenic risks were below the safety threshold (HI < 1). Regarding carcinogenic risks, exposure to both bulk deposition and soil indicated a moderated potential for cancerous development (Incremental lifetime cancer risk ~ 3.0 × 10−6).Facultad de Ciencias Naturales y Muse

Prevention of Staphylococcus aureus biofilm formation by antibiotics in 96-Microtiter Well Plates and Drip Flow Reactors : critical factors influencing outcomes

Biofilm formation leads to the failure of antimicrobial therapy. Thus, biofilm prevention is a desirable goal of antimicrobial research. In this study, the efficacy of antibiotics (doxycycline, oxacillin and rifampicin) in preventing Staphylococcus aureus biofilms was investigated using Microtiter Well Plates (MWP) and Drip Flow Reactors (DFR), two models characterized by the absence and the presence of a continuous flow of nutrients, respectively. Planktonic culture of S. aureus was exposed to antibiotics for one hour followed by 24 hours incubation with fresh nutrients in MWP or continuous flow of nutrients in DFR. The DFR grown biofilms were significantly more tolerant to the antibiotics than those grown in MWP without the continuous flow. The differences in log reductions (LR) between the two models could not be attributed to differences in the cell density, the planktonic inoculum concentration or the surface-area-to-volume ratios. However, eliminating the flow in the DFR significantly restored the antibiotic susceptibility. These findings demonstrate the importance of considering differences between experimental conditions in different model systems, particularly the flow of nutrients, when performing anti-biofilm efficacy evaluations. Biofilm antibiotic efficacy studies should be assessed using various models and more importantly, in a model mimicking conditions of its clinical application.Peer reviewe

Evaluation of Aedes aegypti densonucleosis (AeDNV) infection in adult mosquito mortality

Aedes aegypti densonucleosis virus (AeDNV) has long been considered a likely agent in biologic control against arthropod-borne diseases. Extensive studies have been done to evaluate infection and pathogeneses in Aedes aegypti larvae and pupae, but only primary studies have been preformed in adults. The primary studies on adult mortality produced a two part mortality curve that showed high levels of early mortality, low levels of intermediate mortality and high levels of late mortality. It was hypothesized that the high levels of early mortality were due to high levels of virus infection, whereas the high levels late mortality were due to old age. In this study we analyzed the mosquitoes that died early and late in the mortality assay with quantitative PCR to determine virus titers in individual mosquitoes. We found that there is no significant difference between titer level of mosquitoes that died in the early part of the curve (Day 17-29), which had an average of 1.264 x 1011 genome equivalents per ml and those that died in the late part of the curve (Day 45-54), which had an average of 2.255 x 1011 genome equivalents per ml.Highest Honors

(+)-Dehydroabietic Acid, an Abietane-Type Diterpene, Inhibits Staphylococcus aureus Biofilms in Vitro

Peer reviewe