The Effect of Zonally Asymmetric Ozone Heating on the Northern Hemisphere Winter Polar Stratosphere

[1] Previous modeling studies have found significant differences in winter extratropical stratospheric temperatures depending on the presence or absence of zonally asymmetric ozone heating (ZAOH), yet the physical mechanism causing these differences has not been fully explained. The present study describes the effect of ZAOH on the dynamics of the Northern Hemisphere extratropical stratosphere using an ensemble of free-running atmospheric general circulation model simulations over the 1 December - 31 March period. We find that the simulations including ZAOH produce a significantly warmer and weaker stratospheric polar vortex in mid-February due to more frequent major stratospheric sudden warmings compared to the simulations using only zonal mean ozone heating. This is due to regions of enhanced Eliassen-Palm flux convergence found in the region between 40°N–70°N latitude and 10–0.05 hPa. These results are consistent with changes in the propagation of planetary waves in the presence of ZAOH predicted by an ozone-modified refractive index

Segregation of cortical head direction cell assemblies on alternating theta cycles

High-level cortical systems for spatial navigation, including entorhinal grid cells, critically depend on input from the head direction system. We examined spiking rhythms and modes of synchrony between neurons participating in head direction networks for evidence of internal processing, independent of direct sensory drive, which may be important for grid cell function. We found that head direction networks of rats were segregated into at least two populations of neurons firing on alternate theta cycles (theta cycle skipping) with fixed synchronous or anti-synchronous relationships. Pairs of anti-synchronous theta cycle skipping neurons exhibited larger differences in head direction tuning, with a minimum difference of 40 degrees of head direction. Septal inactivation preserved the head direction signal, but eliminated theta cycle skipping of head direction cells and grid cell spatial periodicity. We propose that internal mechanisms underlying cycle skipping in head direction networks may be critical for downstream spatial computation by grid cells.We kindly thank S. Gillet, J. Hinman, E. Newman and L. Ewell for their invaluable consultations and comments on previous versions of this manuscript, as well as M. Connerney, S. Eriksson, C. Libby and T. Ware for technical assistance and behavioral training. This work was supported by grants from the National Institute of Mental Health (R01 MH60013 and MH61492) and the Office of Naval Research Multidisciplinary University Research Initiative (N00014-10-1-0936). (R01 MH60013 - National Institute of Mental Health; MH61492 - National Institute of Mental Health; N00014-10-1-0936 - Office of Naval Research Multidisciplinary University Research Initiative)Accepted manuscrip

Update of the Navy Contract Writing Guide

MBA Professional ReportThe purpose of this MBA Project is to provide a comprehensive update of the Navy Contract Writing Guide. The project was conducted with the sponsorship and assistance of the Office of the Assistant Secretary of the Navy for Research, Development, and Acquisition. The now out of date guide was originally written in 1996 in an effort to reduce problem disbursements as related to contract wording and organization. Extensive research, incorporating interviews, websites, periodicals, and texts, was employed to make the guide current. It has been reorganized to address issues and solutions in the same order in which the forms used by contracting officers and administrators have them listed. New issues have been raised since the original writing of this guide and are now incorporated with their recommended solutions. Individuals new to Naval contracting or those who have decades of experience will find the information provided useful to the efficient and effective writing and administration of government contracts.http://archive.org/details/updateofnavycont1094534235Second Lieutenant, United States Air ForceCaptain, United States Marine CorpsApproved for public release; distribution is unlimited

Static Torsion Testing and Modeling of a Variable Thickness Hybrid Composite Bull Gear

Torsional strength of a variable thickness hybrid gear web was measured by performing static testing on the part in a large torsion test frame. The outer rim of the hybrid gear web was fixed to the bottom of the test frame and loading was applied to the web through a shaft. The test setup included the installation of digital image correlation (DIC) systems to obtain deformation and strain measurements from the surfaces of the hybrid gear web and the mechanical test equipment to ensure reliability of the test. The results indicated that the variable thickness hybrid gear web achieved approximately twice the torsional strength compared to that of previous hybrid gear designs. The DIC analysis showed significantly more straining of the loading shaft than the actual test article. Additionally, the results demonstrated the importance and affect that the metallic, lobed interlock features had on the principal strain and out-of-plane displacement fields. The analysis revealed that the fixed outer rim was in fact rotating and a rigid body motion compensation (RBMC) function was computed to determine the actual rotation of the hub and composite web relative to the outer rim. Modeling simulations were performed for the variable thickness hybrid gear web and correlated well with the RBMC rotational deformation seen in the DIC analysis. In addition to benchmarking the load capacity of the hybrid gear web, measuring its strength is useful information to define the parameters needed for dynamic, endurance, and other testing of the part

Deep dielectric charging of regolith within the Moon\u27s permanently shadowed regions

Abstract Energetic charged particles, such as galactic cosmic rays (GCRs) and solar energetic particles (SEPs), can penetrate deep within the lunar surface, resulting in deep dielectric charging. This charging process depends on the GCR and SEP currents, as well as on the regolith\u27s electrical conductivity and permittivity. In permanently shadowed regions (PSRs) near the lunar poles, the discharging timescales are on the order of a lunation (∼20 days). We present the first predictions for deep dielectric charging of lunar regolith. To estimate the resulting subsurface electric fields, we develop a data-driven, one-dimensional, time-dependent model. For model inputs, we use GCR data from the Cosmic Ray Telescope for the Effects of Radiation on board the Lunar Reconnaissance Orbiter and SEP data from the Electron, Proton, and Alpha Monitor on the Advanced Composition Explorer. We find that during the recent solar minimum, GCRs create persistent electric fields up to ∼700 V/m. We also find that large SEP events create transient but strong electric fields (≥106 V/m) that may induce dielectric breakdown. Such breakdown would likely result in significant modifications to the physical and chemical properties of the lunar regolith within PSRs. Key Points Energetic charged particles deep dielectrically charge the lunar regolithWe model the resulting subsurface electric fieldsThe electric fields may be great enough to induce dielectric breakdown

The relationship between worry, rumination, and comorbidity: Evidence for repetitive negative thinking as a transdiagnostic construct

Background: Repetitive negative thinking (RNT) increases vulnerability to multiple anxiety and depressive disorders and, as a common risk factor, elevated RNT may account for the high levels of comorbidity observed between emotional disorders. The aims of this study were to (a) compare two common forms of RNT (worry and rumination) across individuals with non-comorbid anxiety or depressive disorders, and (b) to examine the relationship between RNT and comorbidity.Methods: A structured diagnostic interview and measures of rumination, worry, anxiety, and depression were completed by a large clinical sample with an anxiety disorder or depression (N=513) presenting at a community mental health clinic.Results: Patients without (n=212) and with (n=301) comorbid diagnoses did not generally differ across the principal diagnosis groups (depression, generalised anxiety disorder, social anxiety disorder, panic disorder) on worry or rumination. As predicted, comorbidity was associated with a higher level of RNT.Limitations: Cross-sectional design precluded causal conclusions and findings may not generalize to excluded anxiety disorders.Conclusions: Consistent with the transdiagnostic hypothesis, RNT was associated with a range of anxiety disorders and depression and with comorbidity for those with a principal depressive disorder, supporting recent evidence that RNT is a transdiagnostic process. The presence of RNT, specifically worry and rumination, should be assessed and treated regardless of diagnostic profile. Future research may show that both pure and comorbid depressed or anxious patients receive incremental benefit from transdiagnostic protocols developed to treat core pathological processes of RNT traditionally associated with separate disorders

Plasma macrophage colony-stimulating factor levels during cardiopulmonary bypass with extracorporeal circulation

Leukocytosis and thrombocytopenia occur during cardiopulmonary bypass (CPB) with extracorporeal circulation (ECC). Elevated circulating concentrations of macrophage colony-stimulating factor (M-CSF) are reported during thrombocytopenia and leukopenia of different origins. We have assessed M-CSF concentrations in 40 patients undergoing CPB with ECC. Plasma M-CSF concentrations were stable during ECC and increased at the 6th (7.3 ± 0.7 IU/μg protein) and 24th (8.6 ± 0.8 IU/μg protein) postoperative hour compared with pre-ECC values (4.9 ± 0.5 IU/μg protein). A deep thrombocytopenia was found during ECC and until the 24th postoperative hour. A drop of leukocyte counts was found during ECC followed by an increase after ECC weaning. While no correlation was found between M-CSF concentrations and the leukocyte counts, M-CSF values were positively correlated with platelet counts only before and during ECC. Thus, M-CSF is not implicated in the thrombocytopenia and the leukopenia generated during CPB with ECC. However the elevated levels of M-CSFa few hours after the end of ECC might play a role in the inflammatory process often observed after CPB