58 research outputs found

    Toxic Power: What the Toxics Release Inventory Tells Us About Power Plant Pollution

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    Examines nationwide and state electric utility data to show the quantity and nature of toxic pollutants reported by power plants, and describes the potential health damage they can cause. Suggests ways for reducing toxic power plant pollution

    Complementary Control of Sensory Adaptation by Two Types of Cortical Interneurons

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    Reliably detecting unexpected sounds is important for environmental awareness and survival. By selectively reducing responses to frequently, but not rarely, occurring sounds, auditory cortical neurons are thought to enhance the brain\u27s ability to detect unexpected events through stimulus-specific adaptation (SSA). The majority of neurons in the primary auditory cortex exhibit SSA, yet little is known about the underlying cortical circuits. We found that two types of cortical interneurons differentially amplify SSA in putative excitatory neurons. Parvalbumin-positive interneurons (PVs) amplify SSA by providing non-specific inhibition: optogenetic suppression of PVs led to an equal increase in responses to frequent and rare tones. In contrast, somatostatin-positive interneurons (SOMs) selectively reduce excitatory responses to frequent tones: suppression of SOMs led to an increase in responses to frequent, but not to rare tones. A mutually coupled excitatory-inhibitory network model accounts for distinct mechanisms by which cortical inhibitory neurons enhance the brain\u27s sensitivity to unexpected sounds

    Strongly aligned gas-phase molecules at Free-Electron Lasers

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    We demonstrate a novel experimental implementation to strongly align molecules at full repetition rates of free-electron lasers. We utilized the available in-house laser system at the coherent x-ray imaging beamline at the Linac Coherent Light Source. Chirped laser pulses, i. e., the direct output from the regenerative amplifier of the Ti:Sa chirped pulse amplification laser system, were used to strongly align 2,5-diiodothiophene molecules in a molecular beam. The alignment laser pulses had pulse energies of a few mJ and a pulse duration of 94 ps. A degree of alignment of \left = 0.85 was measured, limited by the intrinsic temperature of the molecular beam rather than by the available laser system. With the general availability of synchronized chirped-pulse-amplified near-infrared laser systems at short-wavelength laser facilities, our approach allows for the universal preparation of molecules tightly fixed in space for experiments with x-ray pulses.Comment: 10 pages, 5 figure

    X-ray diffractive imaging of controlled gas-phase molecules: Toward imaging of dynamics in the molecular frame

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    We report experimental results on the diffractive imaging of three-dimensionally aligned 2,5-diiodothiophene molecules. The molecules were aligned by chirped near-infrared laser pulses, and their structure was probed at a photon energy of 9.5 keV (λ130pm\lambda\approx130 \text{pm}) provided by the Linac Coherent Light Source. Diffracted photons were recorded on the CSPAD detector and a two-dimensional diffraction pattern of the equilibrium structure of 2,5-diiodothiophene was recorded. The retrieved distance between the two iodine atoms agrees with the quantum-chemically calculated molecular structure to within 5 %. The experimental approach allows for the imaging of intrinsic molecular dynamics in the molecular frame, albeit this requires more experimental data which should be readily available at upcoming high-repetition-rate facilities

    Special considerations in the management of adult patients with acute leukaemias and myeloid neoplasms in the COVID-19 era: recommendations from a panel of international experts

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    This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.The ongoing COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 is a global public health crisis. Multiple observations indicate poorer post-infection outcomes for patients with cancer than for the general population. Herein, we highlight the challenges in caring for patients with acute leukaemias and myeloid neoplasms amid the COVID-19 pandemic. We summarise key changes related to service allocation, clinical and supportive care, clinical trial participation, and ethical considerations regarding the use of lifesaving measures for these patients. We recognise that these recommendations might be more applicable to high-income countries and might not be generalisable because of regional differences in health-care infrastructure, individual circumstances, and a complex and highly fluid health-care environment. Despite these limitations, we aim to provide a general framework for the care of patients with acute leukaemias and myeloid neoplasms during the COVID-19 pandemic on the basis of recommendations from international experts

    Use of Gold Nanoparticles To Enhance Capillary Electrophoresis

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    We describe here the use of gold nanoparticles to manipulate the selectivity between solutes in capillary electrophoresis. Two different gold-based nanoparticles were added to the run buffer. In one case, the nanoparticles were stabilized with citrate ions, but in another study, the gold nanoparticles were capped with mercaptopropionate ions (thiol-stablized). Citrate-stabilized gold nanoparticles were used in conjunction with capillaries treated with poly(diallyldimethylammonium chloride) (PDADMAC). The positively charged PDADMAC layer on the capillary walls adsorbs the negatively charged gold nanoparticles. The model solutes that were used to study the effect of the presence of the citrate-stabilized gold nanoparticles are structural isomers of aromatic acids and bases. The presence of the PDADMAC layer and the PDADMAC plus the gold nanoparticles changes both the electroosmotic mobility and the observed mobility of the solutes. These changes in the mobilities influence the observed selectivities and the separations of the system. Thiol-stabilized gold nanoparticles were used without PDADMAC in the capillary. The model solutes studied in this part are various aromatic amines. In this case as well, the presence of the gold nanoparticles modifies the electroosmotic mobility and the observed mobility of the solutes. These changes in the mobilities are manifested in selectivity alterations. The largest change in the selectivities occurs at low concentrations of the gold nanoparticles in the run buffer. The presence of nanoparticles improves the precision of the analysis and increases the separation efficiency. Nanodispersions have attracted extensive attention in various fields of physics, biology, and chemistry. [1][2][3][4][5] Physicists and chemists are intrigued by the gradual transition of the nanomaterial properties from molecule-like to those of solid-state properties by a change of a single variable, the particle size. This property has practical and future applications for nonlinear optics and electronics. The large surface area of nanomaterials intrigues chemical engineers and catalysis scientists. Surprisingly, very little research has been devoted to the application of nanoparticles for chemical separation. In this work, we demonstrate the utility and versatility of organically modified gold nanoparticles in capillary electrophoresis (CE) separations. The nanoparticles serve as large surface area platforms for organofunctional groups that interact with the capillary surface, the analytes, or both. Thus, the apparent mobilities of target analytes, as well as the electroosmotic flow, can be altered leading to enhanced selectivities. Separation of various benzene derivatives demonstrates these capabilities. Metallic nanodispersions can be prepared in aqueous and organic solvents using diverse procedures. 1,2,6-9 Nanodispersions can be stabilized in organic solvents by the solvent itself, 10 by the addition of long chain surfactants, 11,12 or by specific ligands. 13 Stabilization of metal nanodispersions in aqueous solutions is somewhat more complicated. Several successful stabilization methods are available that are based on capping of the metal nanoparticles (e.g., citrate, 6 3-mercaptopropionate, 1

    Activating PVs increases tone-evoked responses, whereas suppressing PVs has the opposite effect.

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    <p>A, C, E. Scaled time course of the firing rate of the neurons in response to a tone (outlined by black dashed lines) on light-On (color) and light-Off (gray) trials. Time of laser onset and offset is outlines by vertical color dashed lines. Mean ± SEM. A. PV-ChR2 mice. C. PV-Arch mice. E. CamKIIα-ChR2 mice. Inset diagram shows circuits targeted by photomodulation. B, D, F. Left. Scaled responses to tones on light-On trials plotted against responses on light-Off trials for putative excitatory neurons. Response magnitude is defined as a difference in mean scaled FR<sub>base</sub> (0–50 ms before tone onset) and mean response to tone (FR<sub>tone</sub>, 0–50 ms after tone onset). Right. Mean ± SEM. responses to tones from the left panel. See data in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1002308#pbio.1002308.s001" target="_blank">S1 Data</a>. B. PV-ChR2 mice: Tone-evoked responses on light-On trials (blue) were significantly higher than on light-Off trials (gray). Paired <i>t</i> test, <i>n</i> = 550, <i>t</i><sub>549</sub> = 5.81, <i>p</i> = 1.1e-8. Data are combined for three laser powers used to activate PV interneurons (0.2, 0.5, and 10 mW/mm<sup>2</sup>). D. PV-Arch mice: Tone-evoked responses on light-On trials (green) were significantly lower than on light-Off trials (gray). Paired <i>t</i> test, <i>n</i> = 127, <i>t</i><sub>126</sub> = 6.70, <i>p</i> = 6.3e-10. F. CamKIIα-ChR2 mice: Tone-evoked responses were not significantly affected by light. Paired <i>t</i> test, <i>n</i> = 130, <i>t</i><sub>129</sub> = 1.19, <i>p</i> = 0.22. G. Change in the magnitude of scaled response to tones is correlated with change in behavioral <i>Th</i> due to manipulation of PVs activity. Each dot represents data averaged for single units from each subject at one light intensity (only subjects with >5 identified single units were included). Blue: PV-ChR2 group (<i>n</i> = 28); Green: PV-Arch group (<i>n</i> = 5). Magenta: CamkIIα-ChR2 group (<i>n</i> = 6, not included in regression analysis). <i>p</i> = 0.01.</p
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