Exact Hypersurface-Homogeneous Solutions in Cosmology and Astrophysics

A framework is introduced which explains the existence and similarities of most exact solutions of the Einstein equations with a wide range of sources for the class of hypersurface-homogeneous spacetimes which admit a Hamiltonian formulation. This class includes the spatially homogeneous cosmological models and the astrophysically interesting static spherically symmetric models as well as the stationary cylindrically symmetric models. The framework involves methods for finding and exploiting hidden symmetries and invariant submanifolds of the Hamiltonian formulation of the field equations. It unifies, simplifies and extends most known work on hypersurface-homogeneous exact solutions. It is shown that the same framework is also relevant to gravitational theories with a similar structure, like Brans-Dicke or higher-dimensional theories.Comment: 41 pages, REVTEX/LaTeX 2.09 file (don't use LaTeX2e !!!) Accepted for publication in Phys. Rev.

Measurement of atmospheric elemental carbon: Real-time data for Los Angeles during summer 1987

Two fundamentally different techniques for measuring atmospheric elemental carbon (EC) aerosol were compared to validate the methods. One technique, photoacoustic spectroscopy, was used to measure the optical absorption ([lambda] = 514.5 nm) of in situ atmospheric aerosol in real time. This optical absorption can be converted to EC concentration using the appropriate value of the absorption cross-section for C, so that a comparison could be made with the second technique, thermal-optical analysis of filter-collected samples, which measures the collected EC by combustion. Solvent extraction of the filter samples prior to the thermal analysis procedure was required to minimize errors due to pyrolysis of organic carbon. Excellent 1:1 correlation of atmospheric EC concentrations resulted for measurements by the photoacoustic method vs the thermal method over coincident sampling times. The linear regression gave y = 1.006 (+/-0.056) x+0.27 (+/-0.56) with R = 0.945 (n = 41), where y is the photoacoustic EC concentration and x is the thermal elemental carbon concentration, both in [mu]g m-3. This data set was collected in Los Angeles as part of the Southern California Air Quality Study (SCAQS) during the summer 1987, and supplements the results of an earlier, more limited data set taken in Dearborn, MI. The diurnal variability of EC aerosol in Los Angeles during SCAQS, as determined by photoacoustic spectroscopy, is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28903/1/0000740.pd

Real-time, in situ measurements of atmospheric optical absorption in the visible via photoacoustic spectroscopy--IV. Visibility degradation and aerosol optical properties in Los Angeles

Aerosol light absorption (babs) has been measured in real-time in Los Angeles with a validated photoacoustic technique, and its impact on visibility degradation has been examined. These measurements were collected during ten days in the summer of 1987 for the Southern California Air Quality Study (SCAQS). Aerosol babs ([lambda] = 514.5 nm) varied from an hourly average value of 7 x 10-6 m-1 in the 3-4 and 4-5 a.m. periods of 13 July to 9 x 10-5 m-1 in the 7-8 a.m. period of both 28 August and 3 September. This babs, which is due solely to elemental carbon (EC) showed a distinct diurnal pattern with low values at night, increasing around sunrise to higher values through mid-afternoon. Comparison of these data with aerosol light scattering data clearly illustrates that the contribution of aerosol light absorption to visibility degradation increases in importance under less polluted conditions. Other urban and rural studies show similar results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28906/1/0000743.pd

Using behavior-analytic implicit tests to assess sexual interests among normal and sex-offender populations

The development of implicit tests for measuring biases and behavioral predispositions is a recent development within psychology. While such tests are usually researched within a social-cognitive paradigm, behavioral researchers have also begun to view these tests as potential tests of conditioning histories, including in the sexual domain. The objective of this paper is to illustrate the utility of a behavioral approach to implicit testing and means by which implicit tests can be built to the standards of behavioral psychologists. Research findings illustrating the short history of implicit testing within the experimental analysis of behavior are reviewed. Relevant parallel and overlapping research findings from the field of social cognition and on the Implicit Association Test are also outlined. New preliminary data obtained with both normal and sex offender populations are described in order to illustrate how behavior-analytically conceived implicit tests may have potential as investigative tools for assessing histories of sexual arousal conditioning and derived stimulus associations. It is concluded that popular implicit tests are likely sensitive to conditioned and derived stimulus associations in the history of the test-taker rather than 'unconscious cognitions', per se

Mucosal Expression of Type 2 and Type 17 Immune Response Genes Distinguishes Ulcerative Colitis From Colon-Only Crohn's Disease in Treatment-Naive Pediatric Patients

Background & Aims There is controversy regarding the role of the type 2 immune response in the pathogenesis of ulcerative colitis (UC)?few data are available from treatment-naive patients. We investigated whether genes associated with a type 2 immune response in the intestinal mucosa are up-regulated in treatment-naive pediatric patients with UC compared with patients with Crohn's disease (CD)-associated colitis or without inflammatory bowel disease (IBD), and whether expression levels are associated with clinical outcomes. Methods We used a real-time reverse-transcription quantitative polymerase chain reaction array to analyze messenger RNA (mRNA) expression patterns in rectal mucosal samples from 138 treatment-naive pediatric patients with IBD and macroscopic rectal disease, as well as those from 49 children without IBD (controls), enrolled in a multicenter prospective observational study from 2008 to 2012. Results were validated in real-time reverse-transcription quantitative polymerase chain reaction analyses of rectal RNA from an independent cohort of 34 pediatric patients with IBD and macroscopic rectal disease and 17 controls from Cincinnati Children's Hospital Medical Center. Results We measured significant increases in mRNAs associated with a type 2 immune response (interleukin [IL]5 gene, IL13, and IL13RA2) and a type 17 immune response (IL17A and IL23) in mucosal samples from patients with UC compared with patients with colon-only CD. In a regression model, increased expression of IL5 and IL17A mRNAs distinguished patients with UC from patients with colon-only CD (P =.001; area under the receiver operating characteristic curve, 0.72). We identified a gene expression pattern in rectal tissues of patients with UC, characterized by detection of IL13 mRNA, that predicted clinical response to therapy after 6 months (odds ratio [OR], 6.469; 95% confidence interval [CI], 1.553?26.94), clinical response after 12 months (OR, 6.125; 95% CI, 1.330?28.22), and remission after 12 months (OR, 5.333; 95% CI, 1.132?25.12). Conclusions In an analysis of rectal tissues from treatment-naive pediatric patients with IBD, we observed activation of a type 2 immune response during the early course of UC. We were able to distinguish patients with UC from those with colon-only CD based on increased mucosal expression of genes that mediate type 2 and type 17 immune responses. Increased expression at diagnosis of genes that mediate a type 2 immune response is associated with response to therapy and remission in pediatric patients with UC

Autoantibodies against type I IFNs in patients with life-threatening COVID-19

Interindividual clinical variability in the course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is vast. We report that at least 101 of 987 patients with life-threatening coronavirus disease 2019 (COVID-19) pneumonia had neutralizing immunoglobulin G (IgG) autoantibodies (auto-Abs) against interferon-w (IFN-w) (13 patients), against the 13 types of IFN-a (36), or against both (52) at the onset of critical disease; a few also had auto-Abs against the other three type I IFNs. The auto-Abs neutralize the ability of the corresponding type I IFNs to block SARS-CoV-2 infection in vitro. These auto-Abs were not found in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and were present in only 4 of 1227 healthy individuals. Patients with auto-Abs were aged 25 to 87 years and 95 of the 101 were men. A B cell autoimmune phenocopy of inborn errors of type I IFN immunity accounts for life-threatening COVID-19 pneumonia in at least 2.6% of women and 12.5% of men

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele