The future of Stardust science Westphal, A. J.; Bridges, J. C.; Brownlee, D. E. ...
Meteoritics & planetary science,
September 2017, 2017-09-00, 20170901, Letnik:
52, Številka:
9
Journal Article
Recenzirano
Odprti dostop
Recent observations indicate that >99% of the small bodies in the solar system reside in its outer reaches—in the Kuiper Belt and Oort Cloud. Kuiper Belt bodies are probably the best‐preserved ...representatives of the icy planetesimals that dominated the bulk of the solid mass in the early solar system. They likely contain preserved materials inherited from the protosolar cloud, held in cryogenic storage since the formation of the solar system. Despite their importance, they are relatively underrepresented in our extraterrestrial sample collections by many orders of magnitude (~1013 by mass) as compared with the asteroids, represented by meteorites, which are composed of materials that have generally been strongly altered by thermal and aqueous processes. We have only begun to scratch the surface in understanding Kuiper Belt objects, but it is already clear that the very limited samples of them that we have in our laboratories hold the promise of dramatically expanding our understanding of the formation of the solar system. Stardust returned the first samples from a known small solar system body, the Jupiter‐family comet 81P/Wild 2, and, in a separate collector, the first solid samples from the local interstellar medium. The first decade of Stardust research resulted in more than 142 peer‐reviewed publications, including 15 papers in Science. Analyses of these amazing samples continue to yield unexpected discoveries and to raise new questions about the history of the early solar system. We identify nine high‐priority scientific objectives for future Stardust analyses that address important unsolved problems in planetary science.
BackgroundA vaccine is needed to prevent human immunodeficiency virus type 1 (HIV-1) infection MethodsA double-blind, randomized trial of a recombinant HIV-1 envelope glycoprotein subunit (rgp120) ...vaccine was conducted among men who have sex with men and among women at high risk for heterosexual transmission of HIV-1. Volunteers received 7 injections of either vaccine or placebo (ratio, 2:1) over 30 months. The primary end point was HIV-1 seroconversion over 36 months ResultsA total of 5403 volunteers (5095 men and 308 women) were evaluated. The vaccine did not prevent HIV-1 acquisition: infection rates were 6.7% in 3598 vaccinees and 7.0% in 1805 placebo recipients; vaccine efficacy (VE) was estimated as 6% (95% confidence interval, −17% to 24%). There were no significant differences in viral loads, rates of antiretroviral-therapy initiation, or the genetic characteristics of the infecting HIV-1 strains between treatment arms. Exploratory subgroup analyses showed nonsignificant trends toward efficacy in preventing infection in the highest risk (VE, 43%; n=247) and nonwhite (VE, 47%; n=914) volunteers (P=.10, adjusted for multiple subgroup comparisons) ConclusionsThere was no overall protective effect. The efficacy trends in subgroups may provide clues for the development of effective immunization approaches
Clinical response to methotrexate (MTX) treatment for children with juvenile idiopathic arthritis (JIA) displays considerable heterogeneity. Currently, there are no reliable predictors to identify ...non-responders: earlier identification could lead to a targeted treatment. We genotyped 759 JIA cases from the UK, the Netherlands and Czech Republic. Clinical variables were measured at baseline and 6 months after start of the treatment. In Phase I analysis, samples were analysed for the association with MTX response using ordinal regression of ACR-pedi categories and linear regression of change in clinical variables, and identified 31 genetic regions (P<0.001). Phase II analysis increased SNP density in the most strongly associated regions, identifying 14 regions (P<1 × 10(-5)): three contain genes of particular biological interest (ZMIZ1, TGIF1 and CFTR). These data suggest a role for novel pathways in MTX response and further investigations within associated regions will help to reach our goal of predicting response to MTX in JIA.
► We examine the relationship between future thinking and cumulative culture. ► The role of future thinking in innovation and information exchange is considered. ► We present an argument that future ...thinking influences a species’ extent of culture. ► Future thinking could facilitate the cumulative nature of human culture.
Cumulative culture denotes the, arguably, human capacity to build on the cultural behaviors of one's predecessors, allowing increases in cultural complexity to occur such that many of our cultural artifacts, products and technologies have progressed beyond what a single individual could invent alone. This process of cumulative cultural evolution underlies human cultural success and has enabled us to reach and inhabit some of the most inhospitable environments on this planet. Why humans, but not other animals, have exhibited a cultural explosion has caused much deliberation. The human propensity to imitate, teach, “mind-read” and cooperate have all featured prominently in accounts of the prerequisites for cumulative culture. However, this may not represent the complete picture. In this article we consider whether there exists a link between future thinking, specifically prospective mental time travel, and the observed distribution of cumulative culture.
Abstract
This work is motivated by previous studies of transatlantic transport of Saharan dust and the observed quasi-static nature of coarse mode aerosol with a volume median diameter (VMD) of ...approximately 3.5 μm. The authors examine coarse mode contributions from transpacific transport of dust to North American aerosol properties using a dataset collected at the high-elevation Storm Peak Laboratory (SPL) and the nearby Atmospheric Radiation Measurement (ARM) Mobile Facility. Collected ground-based data are complemented by quasi-global model simulations and satellite and ground-based observations. The authors identify a major dust event associated mostly with a transpacific plume (about 65% of near-surface aerosol mass) in which the coarse mode with moderate (~3 μm) VMD is distinct and contributes substantially to total aerosol volume (up to 70%) and scattering (up to 40%). The results demonstrate that the identified plume at the SPL site has a considerable fraction of supermicron particles (VMD ~3 μm) and, thus, suggest that these particles have a fairly invariant behavior despite transpacific transport. If confirmed in additional studies, this invariant behavior may simplify considerably parameterizations for size-dependent processes associated with dust transport and removal.
Cronartium ribicola, the introduced pathogen that causes white pine blister rust (WPBR), continues to spread to additional limber pine populations in the Southern Rocky Mountains of Colorado and ...Wyoming. Because WPBR can severely impact ecosystems, forecasts of its potential distribution and incidence would be useful to land managers. Site and climate data from long infested study areas in Wyoming were fit with two regression models logistic and classification and regression trees (CART) to determine the environmental conditions associated with the distribution of WPBR. These models were then used to map limber pine stands at risk of infestation by C. ribicola throughout Wyoming (where it has long occurred) and Colorado (where it is just becoming established). Although variables representing vegetation and landform could identify infested plots, 1‐km‐scale climate variables for monthly temperature and moisture were better predictors of current WPBR distribution and were available for mapping expected future distribution across the region. Of 280 485 ha where limber pine was projected to occur in Colorado, 41% was forecast by the logistic model to be at risk of infestation, and 53%, by the CART model. Of an estimated 782 229 ha in Wyoming with limber pine, the logistic model projected 61% to be at risk; CART projected 79%. Additional regression models were fit with site and climate data to predict WPBR incidence (per cent of trees infected) and intensification (incidence/age of the oldest canker). Nearly one half of the plot‐to‐plot variation in incidence was explained using environmental variables readily available to land managers. Although mean plot incidence increased over time, mean intensification decreased 50% per decade. This work provides managers with several tools to reduce uncertainty over the expected distribution and incidence of WPBR, but surveillance and monitoring remain prudent activities for supplementing forecasts of WPBR epidemics.
Studies of mouse models of tuberculosis (TB) infection have indicated a central role for MHC class I-restricted CD8+ T cells in protective immunity. To define antigens and epitopes of Mycobacterium ...tuberculosis (MTB) proteins that are presented by infected cells to CD8+ T cells, we screened 40 MTB proteins for HLA class I A*0201-binding motifs. Peptides that bound with high affinity to purified HLA molecules were subsequently analyzed for recognition by CD8+ cytotoxic T lymphocytes. We identified three epitopes recognized by CD8+ T cells from patients recovering from TB infection. Those three epitopes were derived from three different antigens: thymidylate synthase (ThyA30-38), RNA polymerase β -subunit (RpoB127-135), and a putative phosphate transport system permease protein A-1 (PstA175-83). In addition, CD8+ T cell lines specific for three peptides (ThyA30-38, PstA175-83, and 85B15-23) were generated from peripheral blood mononuclear cells of normal HLA-A*0201 donors. These CD8+ T cell lines specifically recognized MTB-infected macrophages, as demonstrated by production of IFN-γ and lysis of the infected target cells. Finally, CD8+ cytotoxic T lymphocytes reduced the viability of the intracellular MTB, providing evidence that CD8+ T cell recognition of MHC class I-restricted epitopes of these MTB antigens can contribute to effective immunity against the pathogen.
Abstract We present a targeted search for continuous gravitational waves (GWs) from 236 pulsars using data from the third observing run of LIGO and Virgo (O3) combined with data from the second ...observing run (O2). Searches were for emission from the l = m = 2 mass quadrupole mode with a frequency at only twice the pulsar rotation frequency (single harmonic) and the l = 2, m = 1, 2 modes with a frequency of both once and twice the rotation frequency (dual harmonic). No evidence of GWs was found, so we present 95% credible upper limits on the strain amplitudes h 0 for the single-harmonic search along with limits on the pulsars’ mass quadrupole moments Q 22 and ellipticities ε . Of the pulsars studied, 23 have strain amplitudes that are lower than the limits calculated from their electromagnetically measured spin-down rates. These pulsars include the millisecond pulsars J0437−4715 and J0711−6830, which have spin-down ratios of 0.87 and 0.57, respectively. For nine pulsars, their spin-down limits have been surpassed for the first time. For the Crab and Vela pulsars, our limits are factors of ∼100 and ∼20 more constraining than their spin-down limits, respectively. For the dual-harmonic searches, new limits are placed on the strain amplitudes C 21 and C 22 . For 23 pulsars, we also present limits on the emission amplitude assuming dipole radiation as predicted by Brans-Dicke theory.
The Drug Abuse Treatment Outcome Study (DATOS) collected 1-year follow-up outcomes for 2, 966 clients in outpatient methadone (OMT),
long-term residential (LTR),
outpatient drug-free (ODF),
and ...short-term inpatient (STI) programs in 1991-1993. LTR,
STI,
and ODF clients reported 50% less weekly or daily cocaine use in the follow-up year than in the preadmission year. Reductions were greater (
p
< .01) for clients treated for 3 months or more. Clients still in OMT reported less weekly or daily heroin use than clients who left OMT. Multivariate analysis confirmed that 6 months or more in ODF and LTR and enrollment in OMT were associated with the reductions. Reductions of 50% in illegal activity and 10% increases in full-time employment for LTR clients were related (
p
< .01) to treatment stays of 6 months or longer. The results replicated findings from 1979-1981 for heroin use in OMT and illegal activity and employment for LTR but not for illegal activity in OMT and ODF.
Summary
Background Phenotypically diverse autoimmune conditions share common genetic susceptibility loci and underlying molecular pathways.
Objectives By systematically searching for single ...nucleotide polymorphisms (SNPs) associated with another autoimmune disease, rheumatoid arthritis (RA), we aimed to elucidate novel genetic markers of psoriasis.
Methods We investigated 18 SNPs, previously confirmed as being associated with RA, in a U.K. cohort of 623 patients with early‐onset psoriasis (presenting before age 40 years), comparing them with 2662 control subjects.
Results Our findings confirm the association of early‐onset psoriasis with REL (rs13031237, P = 0·0027). The minor allele of REL had opposing effects upon susceptibility to disease in patients with psoriasis and RA.
Conclusion Similar exploration of additional autoimmune loci and fine mapping of such regions may provide further insight into the genetics and molecular pathophysiology of psoriasis.
What’s already known about this topic?
•
Psoriasis is a complex genetic disease for which 19 genetic susceptibility loci have been identified in caucasians.
•
Phenotypically diverse autoimmune diseases share common underlying genetic susceptibility loci and molecular pathways.
•
There is epidemiological evidence that rheumatoid arthritis occurs more frequently in patients with psoriasis.
•
Association of rheumatoid arthritis susceptibility variants has been previously reported with psoriasis, including association of the IL2/IL21 locus and the REL gene.
What does this study add?
•
By targeting rheumatoid arthritis loci in a U.K. cohort of patients with early‐onset psoriasis, we have independently validated the REL gene as being associated with psoriasis.
PDF
