3,784 research outputs found
Intrusion Prevention And Detection in Small to Medium-Sized Enterprises
This paper will examine in depth the reluctance of small to medium-sized enterprises (SMEs) to implement cybersecurity measures amidst the growing threat of cyberattacks. Small businesses encompass the vast majority of for profit and nonprofit organizations in the world. Due to the growing connectedness of the global economy through the Internet and e-business, the reluctance of SMEs to invest in security measures threatens the very existence of many organizations and their partners. The detection and defense against attacks through intrusion detection systems (IDS) and intrusion prevention systems (IPS) are two solutions that assist in detecting and deflecting potential breaches of security. An extensive look at how both IDS and IPS can provide meaningful solutions to SMEs through their visibility and control measures (including their unique characteristics, applications, and limitations) will be explored
Two Distinct Pseudomonas Effector Proteins Interact with the Pto Kinase and Activate Plant Immunity
AbstractThe Pto serine/threonine kinase of tomato confers resistance to speck disease by recognizing strains of Pseudomonas syringae that express the protein AvrPto. Pto and AvrPto physically interact, and this interaction is required for activation of host resistance. We identified a second Pseudomonas protein, AvrPtoB, that interacts specifically with Pto and is widely distributed among plant pathogens. AvrPtoB is delivered into the plant cell by the bacterial type III secretion system, and it elicits Pto-specific defenses. AvrPtoB has little overall sequence similarity with AvrPto. However, AvrPto amino acids, which are required for interaction with Pto, are present in AvrPtoB and required for its interaction with Pto. Thus, two distinct bacterial effectors activate plant immunity by interacting with the same host protein kinase through a similar structural mechanism
Polarity of disulfide bonds
1Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-329
Amide proton exchange of a dynamic loop in cell extracts
Intrinsic rates of exchange are essential parameters for obtaining protein stabilities from amide 1H exchange data. To understand the influence of the intracellular environment on stability, one must know the effect of the cytoplasm on these rates. We probed exchange rates in buffer and in Escherichia coli lysates for the dynamic loop in the small globular protein chymotrypsin inhibitor 2 using a modified form of the nuclear magnetic resonance experiment, SOLEXSY. No significant changes were observed, even in 100 g dry weight Lâ1 lysate. Our results suggest that intrinsic rates from studies conducted in buffers are applicable to studies conducted under cellular conditions
The small molecule curcumin analog FLLL32 induces apoptosis in melanoma cells via STAT3 inhibition and retains the cellular response to cytokines with anti-tumor activity
Background:
We characterized the biologic effects of a novel small molecule STAT3 pathway inhibitor that is derived from the natural product curcumin. We hypothesized this lead compound would specifically inhibit the STAT3 signaling pathway to induce apoptosis in melanoma cells.
Results:
FLLL32 specifically reduced STAT3 phosphorylation at Tyr705 (pSTAT3) and induced apoptosis at micromolar amounts in human melanoma cell lines and primary melanoma cultures as determined by annexin V/propidium iodide staining and immunoblot analysis. FLLL32 treatment reduced expression of STAT3-target genes, induced caspase-dependent apoptosis, and reduced mitochondrial membrane potential. FLLL32 displayed specificity for STAT3 over other homologous STAT proteins. In contrast to other STAT3 pathway inhibitors (WP1066, JSI-124, Stattic), FLLL32 did not abrogate IFN-Îł-induced pSTAT1 or downstream STAT1-mediated gene expression as determined by Real Time PCR. In addition, FLLL32 did not adversely affect the function or viability of immune cells from normal donors. In peripheral blood mononuclear cells (PBMCs), FLLL32 inhibited IL-6-induced pSTAT3 but did not reduce signaling in response to immunostimulatory cytokines (IFN-Îł, IL 2). Treatment of PBMCs or natural killer (NK) cells with FLLL32 also did not decrease viability or granzyme b and IFN-Îł production when cultured with K562 targets as compared to vehicle (DMSO).
Conclusions:
These data suggest that FLLL32 represents a lead compound that could serve as a platform for further optimization to develop improved STAT3 specific inhibitors for melanoma therapy
New evidence on Allyn Young's style and influence as a teacher
This paper publishes the hitherto unpublished correspondence between Allyn Abbott Young's biographer Charles Blitch and 17 of Young's former students or associates. Together with related biographical and archival material, the paper shows the way in which this adds to our knowledge of Young's considerable influence as a teacher upon some of the twentieth century's greatest economists. The correspondents are as follows: James W Angell, Colin Clark, Arthur H Cole, Lauchlin Currie, Melvin G de Chazeau, Eleanor Lansing Dulles, Howard S Ellis, Frank W Fetter, Earl J Hamilton, Seymour S Harris, Richard S Howey, Nicholas Kaldor, Melvin M Knight, Bertil Ohlin, Geoffrey Shepherd, Overton H Taylor, and Gilbert Walker
Phylogenetic Signal Variation in the Genomes of Medicago (Fabaceae)
Genome-scale data offer the opportunity to clarify phylogenetic relationships that are difficult to resolve with few loci, but they can also identify genomic regions with evolutionary history distinct from that of the species history. We collected whole-genome sequence data from 29 taxa in the legume genus Medicago, then aligned these sequences to the Medicago truncatula reference genome to confidently identify 87 596 variable homologous sites. We used this data set to estimate phylogenetic relationships among Medicago species, to investigate the number of sites needed to provide robust phylogenetic estimates and to identify specific genomic regions supporting topologies in conflict with the genome-wide phylogeny. Our full genomic data set resolves relationships within the genus that were previously intractable. Subsampling the data reveals considerable variation in phylogenetic signal and power in smaller subsets of the data. Even when sampling 5000 sites, no random sample of the data supports a topology identical to that of the genome-wide phylogeny. Phylogenetic relationships estimated from 500-site sliding windows revealed genome regions supporting several alternative species relationships among recently diverged taxa, consistent with the expected effects of deep coalescence or introgression in the recent history of Medicago. [Medicago; phylogenomics; whole-genome resequencing.
Is Environmental Improvement in Automotive Component Design Highly Constrained?
This article investigates the influence of environmental, cost, and performance requirements on the design and management of automotive components through a case study involving instrument panels. To address the question of whether the environmental improvement of an instrument panel (IP) is highly constrained, a lifecycle inventory analysis is used to characterize the major environmental burdens associated with a generic IP defined from an average of three midsized vehicle models. A life-cycle cost analysis is also conducted to understand the market forces operating in the domains of the original equipment manufacturer; consumer; and end-of-life (EOL) vehicle managen. This study indicates that the existing set of environmental requirements, in conjunction with current cost drivers and the large set of manufacturing and use phase functional performance requirements, highly constrain opportunities for environmental improvement Specific improvement strategies-lightweighting, elimination of the painting operation, and reduction in material complexity-are examined in the context of existing system requirements. The near-term forecast for improvements is not optimistic. Innovation will continue in a slow and piecemeal fashion until requirements affecting the total vehicle system are significantly changedPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72780/1/jiec.1998.2.2.103.pd
A bioreactor for in-cell protein NMR
The inside of the cell is a complex environment that is difficult to simulate when studying proteins and other molecules in vitro. We have developed a device and system that provides a controlled environment for Nuclear Magnetic Resonance (NMR) experiments involving living cells. Our device comprises two main parts, an NMR detection region and a circulation system. The flow of medium from the bottom of the device pushes alginate encapsulated cells into the circulation chamber. In the chamber, the exchange of oxygen and nutrients occurs between the media and the encapsulated cells. When the media flow is stopped, the encapsulated cells fall back into the NMR detection region, and spectra can be acquired. We have utilized the bioreactor to study the expression of the natively disordered protein α-synuclein, inside Escherichia coli cells
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