An electrochemical rebalance cell for Redox systems

An electrochemical rebalance cell for maintaining electrochemical balance, at the system level, of the acidified aqueous iron chloride and chromium chloride reactant solutions in the redox energy storage system was constructed and evaluated. The electrochemical reaction for the cathode is Fe(+3) + e(-) yields Fe(+2), and that for the anode is 1/2H2 yields H(+) + e(-). The iron (carbon felt) electrode and the hydrogen (platinized carbon) electrode are separated by an anion exchange membrane. The performance of the rebalance cell is discussed as well as the assembly of a single rebalance cell and multicell stacks. Various cell configurations were tested and the results are presented and discussed. The rebalance cell was also used to demonstrate its ability, as a preparative tool, for making high purity solutions of soluble reduced metal ionic species. Preparations of titanium, copper, vanadium and chromium ions in acidified solutions were evaluated

Survival of Ceriodaphnia dubia (Crustacea, Cladocera) exposed to different screens against natural ultraviolet radiation

The current increase of penetration of natural ultraviolet radiation (UVR) in southern South America affects water bodies because the UVR can penetrate the water column. In this scenario, the zooplankton develops photoprotective strategies such as vertical migrations against UVR or synthesis of photoprotective substances. The present study was done using a population of Ceriodaphnia dubia. That was collected from small shallow wetland near Temuco, Chile. The specimens were exposed for 7 to 9 hours to natural ultraviolet radiation, and with different colored nylon as protection against UVR, the experiment was done during the southern summer of 2006. The results revealed that in the presence of protection against UVR provided by colored nylon, the mortality was low, whereas under exposure to UVR and covering by transparent nylon total mortality was observed. The relation between mortality and the dose of UV that can penetrate the different colored nylon is represented by LC50 in UV (280-400 nm) and UVB (280-320 nm), within intensities of 234.82 and 14.96 kJ/m2, respectively

A Noncanonical Binding Site in the EVH1 Domain of Vasodilator-Stimulated Phosphoprotein Regulates Its Interactions with the Proline Rich Region of Zyxin

Vasodilator-stimulated phosphoprotein (VASP) is a processive actin polymerase with roles in the control of cell shape and cell migration. Through interaction with the cytoskeletal adaptor protein Zyxin, VASP can localize to damaged stress fibers where it serves to repair and reinforce these structures. VASP localization is mediated by its N-terminal Ena/VASP homology (EVH1) domain, which binds to the (W/F)Px phi P motif (most commonly occurring as FPPPP) found in cytoskeletal proteins such as vinculin, lamellipodin, and Zyxin. Sequentially close clusters of four or five of these motifs frequently occur, as in the proline rich region of Zyxin with four such motifs. This suggests that tetrameric VASP might bind very tightly to Zyxin through avidity, with all four EVH1 domains binding to a single Zyxin molecule. Here, quantitative nuclear magnetic resonance titration analysis reveals a dominant bivalent 1:1 (Zyxin:EVH1)interaction between the Zyxin proline rich region and the VASP EVH1 domain that utilizes the EVH1 canonical binding site and a novel secondary binding site on the opposite face of the EVH1 domain. We further show that binding to the secondary binding site is specifically inhibited by mutation of VASP EVH1 domain residue Y39 to E, which mimics Abl-induced phosphorylation of Y39. On the basis of these findings, we propose a model in which phosphorylation of Y39 acts as a stoichiometry switch that governs binding partner selection by the constitutive VASP tetramer. These results have broader implications for other multivalent VASP EVH1 domain binding partners and for furthering our understanding of the role of Y39 phosphorylation in regulating VASP localization and cellular function

Dopamine buffering capacity imaging: A pharmacodynamic fMRI method for staging Parkinson disease

We propose a novel pharmacological fMRI (phMRI) method for objectively quantifying disease severity in Parkinson disease (PD). It is based on the clinical observation that the benefit from a dose of levodopa wears off more quickly as PD progresses. Biologically this has been thought to represent decreased buffering capacity for dopamine as nigrostriatal cells die. Buffering capacity has been modeled based on clinical effects, but clinical measurements are influenced by confounding factors. The new method proposes to measure the effect objectively based on the timing of the known response of several brain regions to exogenous levodopa. Such responses are robust and can be quantified using perfusion MRI. Here we present simulation studies based on published clinical dose-response data and an intravenous levodopa infusion. Standard pharmacokinetic-pharmacodynamic methods were used to model the response. Then the effect site rate constan

Milky Way White Dwarfs as Sub-GeV to Multi-TeV Dark Matter Detectors

We show that Milky Way white dwarfs are excellent targets for dark matter (DM) detection. Using Fermi and H.E.S.S. Galactic center gamma-ray data, we investigate sensitivity to DM annihilating within white dwarfs into long-lived or boosted mediators and producing detectable gamma rays. Depending on the Galactic DM distribution, we set new constraints on the spin-independent scattering cross section down to $10^{-45}-10^{-41}$ cm$^2$ in the sub-GeV DM mass range, which is multiple orders of magnitude stronger than existing limits. For a generalized NFW DM profile, we find that our white dwarf constraints exceed spin-independent direct detection limits across most of the sub-GeV to multi-TeV DM mass range, achieving sensitivities as low as about $10^{-46}$ cm$^2$. In addition, we improve earlier versions of the DM capture calculation in white dwarfs, by including the low-temperature distribution of nuclei when the white dwarf approaches crystallization. This yields smaller capture rates than previously calculated by a factor of a few up to two orders of magnitude, depending on white dwarf size and the astrophysical system.Comment: 29 pages, 5 figure

Production of Porous Alginate Substrates via Membrane Emulsification for Pharmaceutical Applications

The Food and Drug Administration (FDA) released in 2013 a report that established the pharmaceuticals current good manufacturing practices for the 21st century. This report encourages the creation of new technology in the pharmaceutical industry. Therefore, this research aims to develop a reliable method to produce porous polymers particles to be used in a novel continuous crystallization in porous substrate. The aim of the current work is to create porous polymer microspheres with uniform particle size distribution using a commercially available membrane emulsification system. In the present study, the emulsification was made using a dispersed phase composed of miglyol 840 and 2% w/w of span 80, and the aqueous phase composed of 2% w/w of alginate in deionized water and magnesium sulfate (MgSO­­4). Membranes of different pore size (20 μm, 40 μm, and 60 μm) and material (stainless steel and nickel) were tested in order to observe the achievable particle size. A Tagushi design was evaluated considering three levels and four factors (MgSO4 concentration, rotation speed, flow rate, and temperature). The particle size and size distribution was obtained through image analysis of the dried particles. The mean size decreased as the rotation speed and flow rate increases. The temperature did not had a direct impact in the particle size but it reduces the time to generate the particles. No direct impact was observed by changing the MgSO4 concentration

SensiCut: Material-Aware Laser Cutting Using Speckle Sensing and Deep Learning

Laser cutter users face difficulties distinguishing between visually similar materials. This can lead to problems, such as using the wrong power/speed settings or accidentally cutting hazardous materials. To support users, we present SensiCut, an integrated material sensing platform for laser cutters. SensiCut enables material awareness beyond what users are able to see and reliably differentiates among similar-looking types. It achieves this by detecting materials' surface structures using speckle sensing and deep learning. SensiCut consists of a compact hardware add-on for laser cutters and a user interface that integrates material sensing into the laser cutting workflow. In addition to improving the traditional workflow and its safety1, SensiCut enables new applications, such as automatically partitioning designs when engraving on multi-material objects or adjusting their geometry based on the kerf of the identified material. We evaluate SensiCut's accuracy for different types of materials under different sheet orientations and illumination conditions

Children Left Behind: How Metropolitan Areas Are Failing America's Children

Presents findings from the Diversity Data project, an online resource measuring social indicators of quality of life in U.S. metropolitan areas. Focuses on racial and ethnic disparities with a particular emphasis on children and their well-being

Related Enteric Viruses Have Different Requirements for Host Microbiota in Mice

Accumulating evidence suggests that intestinal bacteria promote enteric virus infection in mice. For example, previous work demonstrated that antibiotic treatment of mice prior to oral infection with poliovirus reduced viral replication and pathogenesis. Here, we examined the effect of antibiotic treatment on infection with coxsackievirus B3 (CVB3), a picornavirus closely related to poliovirus. We treated mice with a mixture of five antibiotics to deplete host microbiota and examined CVB3 replication and pathogenesis following oral inoculation. We found that, as seen with poliovirus, CVB3 shedding and pathogenesis were reduced in antibiotic-treated mice. While treatment with just two antibiotics, vancomycin and ampicillin, was sufficient to reduce CVB3 replication and pathogenesis, this treatment had no effect on poliovirus. The quantity and composition of bacterial communities were altered by treatment with the five-antibiotic cocktail and by treatment with vancomycin and ampicillin. To determine whether more-subtle changes in bacterial populations impact viral replication, we examined viral infection in mice treated with milder antibiotic regimens. Mice treated with one-tenth the standard concentration of the normal antibiotic cocktail supported replication of poliovirus but not CVB3. Importantly, a single dose of one antibiotic, streptomycin, was sufficient to reduce CVB3 shedding and pathogenesis while having no effect on poliovirus shedding and pathogenesis. Overall, replication and pathogenesis of CVB3 are more sensitive to antibiotic treatment than poliovirus, indicating that closely related viruses may differ with respect to their reliance on microbiota. IMPORTANCE Recent data indicate that intestinal bacteria promote intestinal infection of several enteric viruses. Here, we show that coxsackievirus, an enteric virus in the picornavirus family, also relies on microbiota for intestinal replication and pathogenesis. Relatively minor depletion of the microbiota was sufficient to decrease coxsackievirus infection, while poliovirus infection was unaffected. Surprisingly, a single dose of one antibiotic was sufficient to reduce coxsackievirus infection. Therefore, these data indicate that closely related viruses may differ with respect to their reliance on microbiota

Drought-stress-induced up-regulation of CAM in seedlings of a tropical cactus, Opuntia elatior, operating predominantly in the C3 mode

Immediately after unfolding, cotyledons of the tropical platyopuntoid cactus, Opuntia elatior Mill., exhibited a C3-type diel CO2 exchange pattern characterized by net CO2 uptake in the light. Significant nocturnal increases in titratable acidity typical of crassulacean acid metabolism (CAM) were not detected at this early developmental stage. As cotyledons matured and the first cladode (flattened stem) developed, features of CAM were observed and the magnitude of CAM increased. Nonetheless, in well-watered seedlings up to 10 cm tall, C3 photosynthetic CO2 fixation in the light remained the major pathway of carbon fixation. Reduced soil water availability led to an up-regulation of net dark CO2 fixation and greater nocturnal increases in tissue acidity, consistent with facultative CAM. These observations demonstrate that C3 photosynthesis, drought-stress-related facultative CAM, and developmentally controlled constitutive CAM can all contribute to the early growth of O. elatior. The strong C3 component and facultative CAM features expressed in young O. elatior contrast with mature plants in which obligate CAM is the major pathway of carbon acquisition