143 research outputs found
On Equatorial Dynamics, Mixed Layer Physics and Sea Surface Temperature
We describe a new numerical model designed to study the interactions between hydrodynamics and thermodynamics in the upper ocean. The model incorporates both primitive equation dynamics and a parameterization of mixed layer physics. There is a consistent treatment of mixed layer structure for all physical processes. In order to study interplay between dynamics and mixed layer physics in the equatorial ocean, we carried out a series of numerical experiments with simple patterns of wind stress and surface heating. In some cases stratification and/or mixed layer physics were suppressed. On the basis of these experiments we reached the following conclusions: The vertical circulation at the equator is so vigorous that surface heating is essential if stratification is to be maintained for periods longer than a few months. Without stratification to inhibit mixed layer deepening momentum will be mixed uniformly to the main thermocline and the equatorial undercurrent will disappear. Vertical transfers of momentum due to vertical advection and mixed layer entrainment are essential features of equatorial dynamics. These process influence currents, SST and upwelling rates more than changes in sea surface elevation. Consequently, the overall mass field adjustments of equatorial oceans are more nearly linear than are the currents or SST variations. The connection between changes in SST and dynamical quantities such as sea surface topography need not be straightforward. For example, increased upwelling will make the mixed layer shallower but will not reduce SST unless it induces increased entrainment of colder water. The influences of upwelling and down-welling on SST are highly asymmetric so that the influence of perturbations cannot be predicted without considering the mean vertical velocity. The asymmetry in the interaction between vertical velocity and mixed layer physics can result in the formation of surface fronts. On the upwelling side of a w = 0 line the surface layer is cold and shallow while on the downwelling side it is warm and deep. Differential advection creates a temperature discontinuity at the depth discontinuity. It is suggested that the Galapagos Front has this character
The CRCES Workshop on Decadal Climate Variability
Author Posting. © American Meteorological Society, 2006. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Bulletin of the American Meteorological Society 87 (2006): 1223–1225, doi:10.1175/BAMS-87-9-1223.The importance of decadal climate variability
(DCV) research is being increasingly recognized,
including by international research programs
such as the World Climate Research Program
(WCRP) and the U.S. National Research Council.
This brief article (workshop presentations available
online at www.DecVar.org/auditorium.php) summarizes
a consensus view of a research community
workshop attended by approximately 45 scientists.
Gaps in our knowledge of DCV and its societal
impacts were identified, as were areas of needed
research and anticipated benefits of research. It is a
major challenge to implement recommendations of
this and other such workshops on climate research in
this era of declining earth science budgets. Therefore,
a phased implementation is recommended, with highest
priority recommendations outlined in a sidebar
to this summary
Calcitization of aragonitic bryozoans in Cenozoic tropical carbonates from East Kalimantan, Indonesia
© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The file attached is the published version of the article
In search of phylogenetic congruence between molecular and morphological data in bryozoans with extreme adult skeletal heteromorphy
peerreview_statement: The publishing and review policy for this title is described in its Aims & Scope. aims_and_scope_url: http://www.tandfonline.com/action/journalInformation?show=aimsScope&journalCode=tsab20© Crown Copyright 2015. This document is the author's final accepted/submitted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it
Panspermia, Past and Present: Astrophysical and Biophysical Conditions for the Dissemination of Life in Space
Astronomically, there are viable mechanisms for distributing organic material
throughout the Milky Way. Biologically, the destructive effects of ultraviolet
light and cosmic rays means that the majority of organisms arrive broken and
dead on a new world. The likelihood of conventional forms of panspermia must
therefore be considered low. However, the information content of dam-aged
biological molecules might serve to seed new life (necropanspermia).Comment: Accepted for publication in Space Science Review
Aryl Hydrocarbon Receptor Interacting Protein Maintains Germinal Center B Cells through Suppression of BCL6 Degradation
B cell lymphoma-6 (BCL6) is highly expressed in
germinal center B cells, but how its expression is
maintained is still not completely clear. Aryl hydrocarbon
receptor interacting protein (AIP) is a cochaperone
of heat shock protein 90. Deletion of
Aip in B cells decreased BCL6 expression, reducing
germinal center B cells and diminishing adaptive immune
responses. AIP was required for optimal AKT
signaling in response to B cell receptor stimulation,
and AIP protected BCL6 from ubiquitin-mediated
proteasomal degradation by the E3-ubiquitin ligase
FBXO11 by binding to the deubiquitinase UCHL1,
thus helping to maintain the expression of BCL6.
AIP was highly expressed in primary diffuse large
B cell lymphomas compared to healthy tissue and
other tumors. Our findings describe AIP as a positive
regulator of BCL6 expression with implications for
the pathobiology of diffuse large B cell lymphoma
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Repair or destruction: an intimate liaison between ubiquitin ligases and molecular chaperones in proteostasis
Cellular differentiation, developmental processes, and environmental factors challenge the integrity of the proteome in every eukaryotic cell. The maintenance of protein homeostasis, or proteostasis, involves folding and degradation of damaged proteins, and is essential for cellular function, organismal growth, and viability [1, 2]. Misfolded proteins that cannot be refolded by chaperone machineries are degraded by specialized proteolytic systems. A major degradation pathway regulating cellular proteostasis is the ubiquitin/proteasome-system (UPS), which regulates turnover of damaged proteins that accumulate upon stress and during aging. Despite the large number of structurally unrelated substrates, ubiquitin conjugation is remarkably selective. Substrate selectivity is mainly provided by the group of E3 enzymes. Several observations indicate that numerous E3 ubiquitin ligases intimately collaborate with molecular chaperones to maintain the cellular proteome. In this Review, we provide an overview of specialized quality control E3 ligases playing a critical role in the degradation of damaged proteins. The process of substrate recognition and turnover, the type of chaperones they team up with, and the potential pathogeneses associated with their malfunction will be further discusse
German evidence-based guidelines for the treatment of Psoriasis vulgaris (short version)
Psoriasis vulgaris is a common and chronic inflammatory skin disease which has the potential to significantly reduce the quality of life in severely affected patients. The incidence of psoriasis in Western industrialized countries ranges from 1.5 to 2%. Despite the large variety of treatment options available, patient surveys have revealed insufficient satisfaction with the efficacy of available treatments and a high rate of medication non-compliance. To optimize the treatment of psoriasis in Germany, the Deutsche Dermatologische Gesellschaft and the Berufsverband Deutscher Dermatologen (BVDD) have initiated a project to develop evidence-based guidelines for the management of psoriasis. The guidelines focus on induction therapy in cases of mild, moderate, and severe plaque-type psoriasis in adults. The short version of the guidelines reported here consist of a series of therapeutic recommendations that are based on a systematic literature search and subsequent discussion with experts in the field; they have been approved by a team of dermatology experts. In addition to the therapeutic recommendations provided in this short version, the full version of the guidelines includes information on contraindications, adverse events, drug interactions, practicality, and costs as well as detailed information on how best to apply the treatments described (for full version, please see Nast et al., JDDG, Suppl 2:S1–S126, 2006; or http://www.psoriasis-leitlinie.de)
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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