Monitoring the Variable Interstellar Absorption toward HD 219188 with HST/STIS

We discuss the results of continued spectroscopic monitoring of the variable intermediate-velocity (IV) absorption at v = -38 km/s toward HD 219188. After reaching maxima in mid-2000, the column densities of both Na I and Ca II in that IV component declined by factors >= 2 by the end of 2006. Comparisons between HST/STIS echelle spectra obtained in 2001, 2003, and 2004 and HST/GHRS echelle spectra obtained in 1994--1995 indicate the following: (1) The absorption from the dominant species S II, O I, Si II, and Fe II is roughly constant in all four sets of spectra -- suggesting that the total N(H) and the (mild) depletions have not changed significantly over a period of nearly ten years. (2) The column densities of the trace species C I (both ground and excited fine-structure states) and of the excited state C II* all increased by factors of 2--5 between 1995 and 2001 -- implying increases in the hydrogen density n_H (from about 20 cm^{-3} to about 45 cm^{-3}) and in the electron density n_e (by a factor >= 3) over that 6-year period. (3) The column densities of C I and C II* -- and the corresponding inferred n_H and n_e -- then decreased slightly between 2001 and 2004. (4) The changes in C I and C II* are very similar to those seen for Na I and Ca II. The relatively low total N(H) and the modest n_H suggest that the -38 km/s cloud toward HD 219188 is not a very dense knot or filament. Partial ionization of hydrogen appears to be responsible for the enhanced abundances of Na I, C I, Ca II, and C II*. In this case, the variations in those species appear to reflect differences in density and ionization [and not N(H)] over scales of tens of AU.Comment: 33 pages, 6 figures, aastex, accepted to Ap

Spatially explicit estimates of N2O emissions from croplands suggest climate mitigation opportunities from improved fertilizer management

With increasing nitrogen (N) application to croplands required to support growing food demand, mitigating N2O emissions from agricultural soils is a global challenge. National greenhouse gas emissions accounting typically estimates N2O emissions at the country scale by aggregating all crops, under the assumption that N2O emissions are linearly related to N application. However, field studies and meta-analyses indicate a nonlinear relationship, in which N2O emissions are relatively greater at higher N application rates. Here we apply a super-linear emissions response model to crop-specific, spatially-explicit synthetic N fertilizer and manure N inputs to provide subnational accounting of global N2O emissions from croplands. We estimate 0.66 Tg of N2O-N direct global emissions circa 2000, with 50% of emissions concentrated in 13% of harvested area. Compared to estimates from the IPCC Tier 1 linear model, our updated N2O emissions range from 20-40% lower throughout Sub-Saharan Africa and Eastern Europe, to >120% greater in some Western European countries. At low N application rates, the weak non-linear response of N2O emissions suggests that relatively large increases in N fertilizer application would generate relatively small increases in N2O emissions. Since aggregated fertilizer data generate underestimation bias in nonlinear models, high-resolution N application data are critical to support accurate N2O emissions estimates

A model for atomic and molecular interstellar gas: The Meudon PDR code

We present the revised ``Meudon'' model of Photon Dominated Region (PDR code), presently available on the web under the Gnu Public Licence at: http://aristote.obspm.fr/MIS. General organisation of the code is described down to a level that should allow most observers to use it as an interpretation tool with minimal help from our part. Two grids of models, one for low excitation diffuse clouds and one for dense highly illuminated clouds, are discussed, and some new results on PDR modelisation highlighted.Comment: accepted in ApJ sup

Polarons with a twist

We consider a polaron model where molecular \emph{rotations} are important. Here, the usual hopping between neighboring sites is affected directly by the electron-phonon interaction via a {\em twist-dependent} hopping amplitude. This model may be of relevance for electronic transport in complex molecules and polymers with torsional degrees of freedom, such as DNA, as well as in molecular electronics experiments where molecular twist motion is significant. We use a tight-binding representation and find that very different polaronic properties are already exhibited by a two-site model -- these are due to the nonlinearity of the restoring force of the twist excitations, and of the electron-phonon interaction in the model. In the adiabatic regime, where electrons move in a {\em low}-frequency field of twisting-phonons, the effective splitting of the energy levels increases with coupling strength. The bandwidth in a long chain shows a power-law suppression with coupling, unlike the typical exponential dependence due to linear phonons.Comment: revtex4 source and one eps figur

Molecular hydrogen, deuterium and metal abundances in the damped Ly-alpha system at z = 3.025 toward QSO 0347-3819

We have detected in high resolution spectra of the quasar Q0347--3819 obtained with the UVES spectrograph at the VLT/Kueyen telescope over 80 absorption features in the Lyman and Werner H2 bands at the redshift of a damped Ly-alpha system at z = 3.025. The z = 3.025 system spans over 80 km/s and exhibits a multicomponent velocity structure in the metal lines. The main component at z = 3.024855 shows a total H2 column density N(H2) = (4.10\pm0.21)*10^{14} cm^{-2} and a fractional molecular abundance f(H2) = (1.94\pm0.10)*10^{-6} derived from the H2 lines arising from J=0 to 5 rotational levels of the ground electronic-vibrational state. For the first time we unambiguously reveal a pronounced [alpha-element/iron-peak] enhancement of [O,Si/Zn] = 0.6\pm0.1 (6 sigma c.l.) at high redshift. The simultaneous analysis of metal and hydrogen lines leads to D/H = (3.75\pm0.25)*10^{-5}. This value is consistent with standard big bang nucleosynthesis if the baryon-to-photon ratio, eta, lies within the range 4.37*10^{-10} <= eta <= 5.32*10^{-10}, implying 0.016 <= Omega_b h^2_100 <= 0.020.Comment: 32 pages, 16 ps figures, accepted to Ap

Phosphoproteomic differences in major depressive disorder postmortem brains indicate effects on synaptic function

There is still a lack in the molecular comprehension of major depressive disorder (MDD) although this condition affects approximately 10% of the world population. Protein phosphorylation is a posttranslational modification that regulates approximately one-third of the human proteins involved in a range of cellular and biological processes such as cellular signaling. Whereas phosphoproteome studies have been carried out extensively in cancer research, few such investigations have been carried out in studies of psychiatric disorders. Here, we present a comparative phosphoproteome analysis of postmortem dorsolateral prefrontal cortex tissues from 24 MDD patients and 12 control donors. Tissue extracts were analyzed using liquid chromatography mass spectrometry in a data-independent manner (LC-MSE). Our analyses resulted in the identification of 5,195 phosphopeptides, corresponding to 802 non-redundant proteins. Ninety of these proteins showed differential levels of phosphorylation in tissues from MDD subjects compared to controls, being 20 differentially phosphorylated in at least 2 peptides. The majority of these phosphorylated proteins were associated with synaptic transmission and cellular architecture not only pointing out potential biomarker candidates but mainly shedding light to the comprehension of MDD pathobiology

Loss of the sphingolipid desaturase DEGS1 causes hypomyelinating leukodystrophy.

Sphingolipid imbalance is the culprit in a variety of neurological diseases, some affecting the myelin sheath. We have used whole-exome sequencing in patients with undetermined leukoencephalopathies to uncover the endoplasmic reticulum lipid desaturase DEGS1 as the causative gene in 19 patients from 13 unrelated families. Shared features among the cases include severe motor arrest, early nystagmus, dystonia, spasticity, and profound failure to thrive. MRI showed hypomyelination, thinning of the corpus callosum, and progressive thalamic and cerebellar atrophy, suggesting a critical role of DEGS1 in myelin development and maintenance. This enzyme converts dihydroceramide (DhCer) into ceramide (Cer) in the final step of the de novo biosynthesis pathway. We detected a marked increase of the substrate DhCer and DhCer/Cer ratios in patients' fibroblasts and muscle. Further, we used a knockdown approach for disease modeling in Danio rerio, followed by a preclinical test with the first-line treatment for multiple sclerosis, fingolimod (FTY720, Gilenya). The enzymatic inhibition of Cer synthase by fingolimod, 1 step prior to DEGS1 in the pathway, reduced the critical DhCer/Cer imbalance and the severe locomotor disability, increasing the number of myelinating oligodendrocytes in a zebrafish model. These proof-of-concept results pave the way to clinical translation

Cardiopulmonary assessment of patients with systemic sclerosis for hematopoietic stem cell transplantation: recommendations from the European Society for Blood and Marrow Transplantation Autoimmune Diseases Working Party and collaborating partners.

Systemic sclerosis (SSc) is a rare disabling autoimmune disease with a similar mortality to many cancers. Two randomized controlled trials of autologous hematopoietic stem cell transplantation (AHSCT) for SSc have shown significant improvement in organ function, quality of life and long-term survival compared to standard therapy. However, transplant-related mortality (TRM) ranged from 3-10% in patients undergoing HSCT. In SSc, the main cause of non-transplant and TRM is cardiac related. We therefore updated the previously published guidelines for cardiac evaluation, which should be performed in dedicated centers with expertize in HSCT for SSc. The current recommendations are based on pre-transplant cardiopulmonary evaluations combining pulmonary function tests, echocardiography, cardiac magnetic resonance imaging and invasive hemodynamic testing, initiated at Northwestern University (Chicago) and subsequently discussed and endorsed within the EBMT ADWP in 2016

Incipient Social Groups: An Analysis via In-Vivo Behavioral Tracking

Social psychology is fundamentally the study of individuals in groups, yet there remain basic unanswered questions about group formation, structure, and change. We argue that the problem is methodological. Until recently, there was no way to track who was interacting with whom with anything approximating valid resolution and scale. In the current study we describe a new method that applies recent advances in image-based tracking to study incipient group formation and evolution with experimental precision and control. In this method, which we term "in vivo behavioral tracking," we track individuals' movements with a high definition video camera mounted atop a large field laboratory. We report results of an initial study that quantifies the composition, structure, and size of the incipient groups. We also apply in-vivo spatial tracking to study participants' tendency to cooperate as a function of their embeddedness in those crowds. We find that participants form groups of seven on average, are more likely to approach others of similar attractiveness and (to a lesser extent) gender, and that participants' gender and attractiveness are both associated with their proximity to the spatial center of groups (such that women and attractive individuals are more likely than men and unattractive individuals to end up in the center of their groups). Furthermore, participants' proximity to others early in the study predicted the effort they exerted in a subsequent cooperative task, suggesting that submergence in a crowd may predict social loafing. We conclude that in vivo behavioral tracking is a uniquely powerful new tool for answering longstanding, fundamental questions about group dynamics