Long-term impact of chronic variable stress in adolescence versus adulthood

Adolescence is a period of active development of stress regulatory neurocircuitry. As a consequence, mechanisms that control the responses to stress are not fully matured during this developmental period, which may result in vulnerability to chronic stress. We hypothesized that adolescent chronic stress would have negative consequences on stress adaptation later in life. Male Wistar rats (PND40) were subjected to chronic variable stress (CVS) for 2 weeks, with 2 daily stressors randomly presented and overnight social stressors twice a week. After five weeks, animals were evaluated during adulthood, using the elevated plus maze (EPM) and the forced swim test (FST). The hypothalamic-pituitary adrenal (HPA) axis response to a 30-min restraint was also assessed. Results are compared to those of adult rats tested 5 weeks following CVS cessation. Our results demonstrate that the long-term effects of CVS are specific to the age of application of the stress regime. We show how behavior and HPA axis response as well as hypothalamic paraventricular nucleus activation can differ with age, resulting in differential behavioral adaptations for animals stressed in adolescence and dysregulation of the HPA axis in the animals stressed in adulthood, These data underscore the importance of the adolescent period in determining resilience of the HPA axis and programming behavioral responses later in life.Fil: Cotella, Evelin Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Scarponi Gómez, Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Lemen, Paige. University of Cincinnati; Estados UnidosFil: Chen, Carrie. University of Cincinnati; Estados UnidosFil: Fernández, Guillermo César. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Hansen, Christian. Laboratorio de Análisis Clínicos Especializados; ArgentinaFil: Herman, James. University of Cincinnati; Estados UnidosFil: Paglini, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin

Solar Stereoscopy with STEREO/EUVI A and B spacecraft from small (6 deg) to large (170 deg) spacecraft separation angles

We performed for the first time stereoscopic triangulation of coronal loops in active regions over the entire range of spacecraft separation angles ($\alpha_{sep}\approx 6^\circ, 43^\circ, 89^\circ, 127^\circ$, and $170^\circ$). The accuracy of stereoscopic correlation depends mostly on the viewing angle with respect to the solar surface for each spacecraft, which affects the stereoscopic correspondence identification of loops in image pairs. From a simple theoretical model we predict an optimum range of $\alpha_{sep} \approx 22^\circ-125^\circ$, which is also experimentally confirmed. The best accuracy is generally obtained when an active region passes the central meridian (viewed from Earth), which yields a symmetric view for both STEREO spacecraft and causes minimum horizontal foreshortening. For the extended angular range of $\alpha_{sep}\approx 6^\circ-127^{\circ}$ we find a mean 3D misalignment angle of $\mu_{PF} \approx 21^\circ-39^\circ$ of stereoscopically triangulated loops with magnetic potential field models, and $\mu_{FFF} \approx 15^\circ-21^\circ$ for a force-free field model, which is partly caused by stereoscopic uncertainties $\mu_{SE} \approx 9^\circ$. We predict optimum conditions for solar stereoscopy during the time intervals of 2012--2014, 2016--2017, and 2021--2023.Comment: Solar Physics, (in press), 22 pages, 9 figure

The Potential of the Geostationary Carbon Cycle Observatory (GeoCarb) to Provide Multi-scale Constraints on the Carbon Cycle in the Americas

The second NASA Earth Venture Mission, Geostationary Carbon Cycle Observatory (GeoCarb), will provide measurements of atmospheric carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and solar-induced fluorescence (SIF) from Geostationary Orbit (GEO). The GeoCarb mission will deliver daily maps of column concentrations of CO2, CH4, and CO over the observed landmasses in the Americas at a spatial resolution of roughly 10 × 10 km. Persistent measurements of CO2, CH4, CO, and SIF will contribute significantly to resolving carbon emissions and illuminating biotic processes at urban to continental scales, which will allow the improvement of modeled biogeochemical processes in Earth System Models as well as monitor the response of the biosphere to disturbance. This is essential to improve understanding of the Carbon-Climate connection. In this paper, we introduce the instrument and the GeoCarb Mission, and we demonstrate the potential scientific contribution of the mission through a series of CO2 and CH4 simulation experiments. We find that GeoCarb will be able to constrain emissions at urban to continental spatial scales on weekly to annual time scales. The GeoCarb mission particularly builds upon the Orbiting Carbon Obserevatory-2 (OCO-2), which is flying in Low Earth Orbit

First 3D Reconstructions of Coronal Loops with the STEREO A+B Spacecraft: IV. Magnetic Modeling with Twisted Force-Free Fields

The three-dimensional (3D) coordinates of stereoscopically triangulated loops provide strong constraints for magnetic field models of active regions in the solar corona. Here we use STEREO/A and B data from some 500 stereoscopically triangulated loops observed in four active regions (2007 Apr 30, May 9, May 19, Dec 11), together with SOHO/MDI line-of-sight magnetograms. We measure the average misalignment angle between the stereoscopic loops and theoretical magnetic field models, finding a mismatch of $\mu=19^\circ-46^\circ$ for a potential field model, which is reduced to $\mu=14^\circ-19^\circ$ for a non-potential field model parameterized by twist parameters. The residual error is commensurable with stereoscopic measurement errors ($\mu_{SE} \approx 8^\circ-12^\circ$). We developed a potential field code that deconvolves a line-of-sight magnetogram into three magnetic field components $(B_x, B_y, B_z)$, as well as a non-potential field forward-fitting code that determines the full length of twisted loops ($L \approx 50-300$ Mm), the number of twist turns (median $N_{twist}=0.06$), the nonlinear force-free $\alpha$-parameter (median $\alpha \approx 4 \times 10^{-11}$ cm$^{-1}$), and the current density (median $j_z \approx 1500$ Mx cm$^{-2}$ s$^{-1}$). All twisted loops are found to be far below the critical value for kink instability, and Joule dissipation of their currents is found be be far below the coronal heating requirement. The algorithm developed here, based on an analytical solution of nonlinear force-free fields that is accurate to second order (in the force-free parameter $\alpha$), represents the first code that enables fast forward-fitting to photospheric magnetograms and stereoscopically triangulated loops in the solar corona.Comment: The Astrophysical Journal (in press), 37 pages, 14 Figure

A Novel Forward-Model Technique For Estimating Euv Imaging Performance - Design And Analysis Of The Suvi Telescope

The Solar Ultraviolet Imager (SUVI) is one of several instruments being fabricated for use on board the upcoming Geostationary Operational Environmental Satellites, GOES-R and - S platforms, as part of NOAA\u27s space weather monitoring fleet. SUVI is a Generalized Cassegrain telescope that employs multilayer coatings optimized to operate in six extreme ultraviolet (EUV) narrow bandpasses centered at 93.9, 131.2, 171.1, 195.1, 284.2 and 303.8 Å. Over the course of its operational lifetime SUVI will image and record full disk, EUV spectroheliograms approximately every few minutes, and telemeter the data to the ground for digital processing. This data will be useful to scientists and engineers wanting to better understand the effects of solar produced EUV radiation with the near-Earth environment. At the focus of the SUVI telescope is a thin, back-illuminated CCD sensor with 21 μm (2.5 arc sec) pixels. At the shortest EUV wavelengths, image degradation from mirror surface scatter effects due to residual optical fabrication errors dominate the effects of both diffraction and geometrical aberrations. Discussed herein, we present a novel forward model that incorporates: (i) application of a new unified surface scatter theory valid for moderately rough surfaces to predict the bidirectional reflectance distribution function (BRDF) produced by each mirror (which uses optical surface metrology to determine the power spectral density, PSD, that characterizes the smoothness of an optical surface); (ii) use of the BRDF for each mirror at each EUV wavelength, in tandem with the optical design, to calculate the in-band point spread function (PSF); (iii) use of the PSF to calculate the fractional ensquared energy in the focal plane of SUVI; (iv) comparison of BRDF measurements taken at 93.9 Å with the forward model predictions and (v) final prediction of the in-band, total system responsivity. © 2010 SPIE

Tuning the Diels-Alder Reaction for Bioconjugation to Maleimide Drug-Linkers.

The thiol-maleimide linkage is widely used for antibody-drug conjugate (ADC) production; however, conjugation of maleimide-drugs could be improved by simplified procedures and reliable conjugate stability. Here, we report the evaluation of electron-rich and cyclic dienes that can be appended to antibodies and reacted with maleimide-containing drugs through the Diels-Alder (DA) reaction. Drug conjugation is fast and quantitative due to reaction acceleration in water, and the linkage is more stable in serum than in the corresponding thiol-maleimide adduct with the same drug. ADCs produced using the DA reaction (DAADCs) are effective in vitro and in vivo, demonstrating the utility of this reaction in producing effective biotherapeutics. Given the large number of commercially available maleimide compounds, this conjugation approach could be readily applied to the production of a wide range of antibody (or protein) conjugates

Adolescent Stress Confers Resilience to Traumatic Stress Later in Life: Role of the Prefrontal Cortex

Background: Adolescent brains are sensitive to stressors. However, under certain circumstances, developmental stress can promote an adaptive phenotype, allowing individuals to cope better with adverse situations in adulthood, thereby contributing to resilience. Methods: Sprague Dawley rats (50 males, 48 females) were subjected to adolescent chronic variable stress (adol CVS) for 2 weeks at postnatal day 45. At postnatal day 85, a group was subjected to single prolonged stress (SPS). After a week, animals were evaluated in an auditory-cued fear conditioning paradigm, and neuronal recruitment during reinstatement was assessed by Fos expression. Patch clamp electrophysiology (17–35 cells/group) was performed in male rats to examine physiological changes associated with resilience. Results: Adol CVS blocked fear potentiation evoked by SPS. We observed that SPS impaired extinction (males) and enhanced reinstatement (both sexes) of the conditioned freezing response. Prior adol CVS prevented both effects. SPS effects were associated with a reduction of infralimbic (IL) cortex neuronal recruitment after reinstatement in males and increased engagement of the central amygdala in females, both also prevented by adol CVS, suggesting different neurocircuits involved in generating resilience between sexes. We explored the mechanism behind reduced IL recruitment in males by studying the intrinsic excitability of IL pyramidal neurons. SPS reduced excitability of IL neurons, and prior adol CVS prevented this effect. Conclusions: Our data indicate that adolescent stress can impart resilience to the effects of traumatic stress on neuroplasticity and behavior. Our data provide a mechanistic link behind developmental stress-induced behavioral resilience and prefrontal (IL) cortical excitability in males