8,685 research outputs found
C-terminal Truncations of the Yeast Nucleoporin Nup145p Produce a Rapid Temperature-conditional mRNA Export Defect and Alterations to Nuclear Structure.
A screen for temperature-sensitive mutants of Saccharomyces cerevisiae defective in nucleocytoplasmic trafficking of poly(A)+ RNA has identified an allele of the NUP145 gene, which encodes an essential nucleoporin. NUP145 was previously identified by using a genetic synthetic lethal screen (E. Fabre, W. C. Boelens, C. Wimmer, I. W. Mattaj, and E. C. Hurt, Cell 78:275-289, 1994) and by using a monoclonal antibody which recognizes the GLFG family of vertebrate and yeast nucleoporins (S. R. Wente and G. Blobel, J. Cell Biol. 125:955-969, 1994). Cells carrying the new allele, nup145-10, grew at 23 and 30 degrees C but were unable to grow at 37 degrees C. Many cells displayed a modest accumulation of poly(A)+ RNA under permissive growth conditions, and all cells showed dramatic and rapid nuclear accumulation of poly(A)+ RNA following a shift to 37 degrees C. The mutant allele contains a nonsense codon which truncates the 1,317-amino-acid protein to 698 amino acids. This prompted us to examine the role of the carboxyl half of Nup145p. Several additional alleles that encode C-terminally truncated proteins or proteins containing internal deletions of portions of the carboxyl half of Nup145p were constructed. Analysis of these mutants indicates that some sequences between amino acids 698 and 1095 are essential for RNA export and for growth at 37 degrees C. In these strains, nuclear accumulation of poly(A)+ RNA and fragmentation of the nucleolus occurred rapidly following a shift to 37 degrees C. Constitutive defects in nuclear pore complex distribution and nuclear structure were also seen in these strains. Although cells lacking Nup145p grew extremely slowly at 23 degrees C and did not grow at 30 degrees C, efficient growth at 23 or 30 degrees C occurred as long as cells produced either the amino 58% or the carboxyl 53% of Nup145p. Strains carrying alleles of NUP145 lacking up to 200 amino acids from the carboxy terminus were viable at 37 degrees C but displayed nucleolar fragmentation and some nuclear accumulation of poly(A)+ RNA following a shift to 37 degrees C. Surprisingly, these strains grew efficiently at 37 degrees C in spite of a reduction in the level of synthesis of rRNAs to approximately 25% of the wild-type level
Modeling atmospheric effects of the September 1859 Solar Flare
We have modeled atmospheric effects, especially ozone depletion, due to a
solar proton event which probably accompanied the extreme magnetic storm of 1-2
September 1859. We use an inferred proton fluence for this event as estimated
from nitrate levels in Greenland ice cores. We present results showing
production of odd nitrogen compounds and their impact on ozone. We also compute
rainout of nitrate in our model and compare to values from ice core data.Comment: Revised version including improved figures; Accepted for publication
in Geophys. Res. Lett, chosen to be highlighted by AG
Elbow
The Elbow, the part of the human body that a blind or partially sighted person takes hold of, four fingers on the inside, thumb on the outside; holding with a firm grip to assist them with navigation. It is a common guiding technique linking two people into an unfamiliar choreography. In the summer of 2015 C&C Gallery hosted an innovative residency programme, transforming the gallery space into a dynamic studio environment in order to respond to ideas surrounding the condition of blindness. During this time eight artists variously came and went, engaging with a whole repertoire of processes, from casting to laser scanning, leaving a variety of traces of their activities. Much of the work, arrived at through a collaborative approach has sought to obliquely cast a shadow across the subject, remaining open towards the process of making, and the work remains in a state of uncertainty even at the time of writing.
During a workshop in the space hosted by John Dickinson-Lilley, the artists wore blind glasses and stumbled rather pathetically around the gallery and the local high street, feeling unsure, insecure and inept, grounded only by the feeling of the floor beneath ones feet and ones fingers upon a companions elbow. Within the space; chalk lines, floor to ceiling columns and laser scanning targets have created an installation for measurement, where diverse material usage- including borax, expanding foam and cat litter humorously confound expectation
Distribution of Legionella Species and Serogroups Isolated by Culture in Patients with Sporadic Community-Acquired Legionellosis: An International Collaborative Survey
This international collaborative survey identified culture-confirmed legionellosis in 508 patients with sporadic community-acquired legionellosis. Legionella pneumophila constituted 91.5% of the isolates. Serogroup 1 was the predominant serogroup (84.2%), and serogroups 2-13 (7.4%) accounted for the remaining serogroups. The Legionella species most commonly isolated were L. longbeachae (3.9%) and L. bozemanii (2.4%), followed by L. micdadei, L. dumoffii, L. feeleii, L. wadsworthii and L. anisa (2.2% combined). L. longbeachae constituted 30.4% of the community-acquired Legionella isolates in Australia and New Zealan
The UPS Prototype: An Experimental End-User Service Across E-Print Archives
A meeting was held in Santa Fe, New Mexico, October 21-22, 1999, to generate discussion and consensus about interoperability of publicly available scholarly information archives. The invitees represented several well known e-print and report archive initiatives, as well as organizations with interests in digital libraries and the transformation of scholarly communication. The central goal of the meeting was to agree on recommendations that would make the creation of end-user services -- such as scientific search engines and linking systems -- for data originating from distributed and dissimilar archives easier. The Universal Preprint Service (UPS) Prototype was developed in preparation for this meeting. As a proof-of-concept of a multi-discipline digital library of publicly available scholarly material, the Prototype harvested nearly 200,000 records from several different archives and created an attractive end-user environment. This paper describes the results of the project. This is done in two ways. On the one hand, the experimental end-user service that was created during the project is illustrated. On the other hand, the lessons that the project team drew from the experience of creating the Prototype are presented
Towards 6G MIMO: Massive Spatial Multiplexing, Dense Arrays, and Interplay Between Electromagnetics and Processing
The increasing demand for wireless data transfer has been the driving force
behind the widespread adoption of Massive MIMO (multiple-input multiple-output)
technology in 5G. The next-generation MIMO technology is now being developed to
cater to the new data traffic and performance expectations generated by new
user devices and services in the next decade. The evolution towards
"ultra-massive MIMO (UM-MIMO)" is not only about adding more antennas but will
also uncover new propagation and hardware phenomena that can only be treated by
jointly utilizing insights from the communication, electromagnetic (EM), and
circuit theory areas. This article offers a comprehensive overview of the key
benefits of the UM-MIMO technology and the associated challenges. It explores
massive multiplexing facilitated by radiative near-field effects, characterizes
the spatial degrees-of-freedom, and practical channel estimation schemes
tailored for massive arrays. Moreover, we provide a tutorial on EM theory and
circuit theory, and how it is used to obtain physically consistent antenna and
channel models. Subsequently, the article describes different ways to implement
massive and dense antenna arrays, and how to co-design antennas with signal
processing. The main open research challenges are identified at the end.Comment: Submitted to Proceedings of the IEEE, 36 pages, 23 figure
Distinct APC subtypes drive spatially segregated CD4+ and CD8+ T-Cell effector activity during skin infection with HSV-1
Efficient infection control requires potent T-cell responses at sites of pathogen replication. However, the regulation of T-cell effector function in situ remains poorly understood. Here, we show key differences in the regulation of effector activity between CD4+ and CD8+ T-cells during skin infection with HSV-1. IFN-Îł-producing CD4+ T cells disseminated widely throughout the skin and draining lymph nodes (LN), clearly exceeding the epithelial distribution of infectious virus. By contrast, IFN-Îł-producing CD8+ T cells were only found within the infected epidermal layer of the skin and associated hair follicles. Mechanistically, while various subsets of lymphoid- and skin-derived dendritic cells (DC) elicited IFN-Îł production by CD4+ T cells, CD8+ T cells responded exclusively to infected epidermal cells directly presenting viral antigen. Notably, uninfected cross-presenting DCs from both skin and LNs failed to trigger IFN-Îł production by CD8+ T-cells. Thus, we describe a previously unappreciated complexity in the regulation of CD4+ and CD8+ T-cell effector activity that is subset-specific, microanatomically distinct and involves largely non-overlapping types of antigen-presenting cells (APC).The work was funded by grant (APP628423 and APP1059514) and fellowship support from the National Health and Medical Research Council Australia
(NHMRC)and the Australian Research Council (ARC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of
the manuscript
Structure of the first representative of Pfam family PF04016 (DUF364) reveals enolase and Rossmann-like folds that combine to form a unique active site with a possible role in heavy-metal chelation.
The crystal structure of Dhaf4260 from Desulfitobacterium hafniense DCB-2 was determined by single-wavelength anomalous diffraction (SAD) to a resolution of 2.01 Å using the semi-automated high-throughput pipeline of the Joint Center for Structural Genomics (JCSG) as part of the NIGMS Protein Structure Initiative (PSI). This protein structure is the first representative of the PF04016 (DUF364) Pfam family and reveals a novel combination of two well known domains (an enolase N-terminal-like fold followed by a Rossmann-like domain). Structural and bioinformatic analyses reveal partial similarities to Rossmann-like methyltransferases, with residues from the enolase-like fold combining to form a unique active site that is likely to be involved in the condensation or hydrolysis of molecules implicated in the synthesis of flavins, pterins or other siderophores. The genome context of Dhaf4260 and homologs additionally supports a role in heavy-metal chelation
Bridging Alone: Religious Conservatism, Marital Homogamy, and Voluntary Association Membership
This study characterizes social insularity of religiously conservative American married couples by examining patterns of voluntary associationmembership. Constructing a dataset of 3938 marital dyads from the second wave of the National Survey of Families and Households, the author investigates whether conservative religious homogamy encourages membership in religious voluntary groups and discourages membership in secular voluntary groups. Results indicate that couples’ shared affiliation with conservative denominations, paired with beliefs in biblical authority and inerrancy, increases the likelihood of religious group membership for husbands and wives and reduces the likelihood of secular group membership for wives, but not for husbands. The social insularity of conservative religious groups appears to be reinforced by homogamy—particularly by wives who share faith with husbands
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