155 research outputs found
A very compact InP-based integrated optic Mach-Zehnder interferometer with a delay difference of 74 ps
A Mach-Zehnder interferometer with 6.0 mm arm length difference was realised on InP. The design is very compact, using deeply etched waveguides and circular bends with 50 mu m radius. The devices show a sinusoidal frequency response with 13.5 GHz period and extinction ratios up to 20 d
Expression Analysis of the Theileria parva Subtelomere-Encoded Variable Secreted Protein Gene Family
Background
The intracellular protozoan parasite Theileria parva transforms bovine lymphocytes inducing uncontrolled proliferation. Proteins released from the parasite are assumed to contribute to phenotypic changes of the host cell and parasite persistence. With 85 members, genes encoding subtelomeric variable secreted proteins (SVSPs) form the largest gene family in T. parva. The majority of SVSPs contain predicted signal peptides, suggesting secretion into the host cell cytoplasm.
Methodology/Principal Findings
We analysed SVSP expression in T. parva-transformed cell lines established in vitro by infection of T or B lymphocytes with cloned T. parva parasites. Microarray and quantitative real-time PCR analysis revealed mRNA expression for a wide range of SVSP genes. The pattern of mRNA expression was largely defined by the parasite genotype and not by host background or cell type, and found to be relatively stable in vitro over a period of two months. Interestingly, immunofluorescence analysis carried out on cell lines established from a cloned parasite showed that expression of a single SVSP encoded by TP03_0882 is limited to only a small percentage of parasites. Epitope-tagged TP03_0882 expressed in mammalian cells was found to translocate into the nucleus, a process that could be attributed to two different nuclear localisation signals.
Conclusions
Our analysis reveals a complex pattern of Theileria SVSP mRNA expression, which depends on the parasite genotype. Whereas in cell lines established from a cloned parasite transcripts can be found corresponding to a wide range of SVSP genes, only a minority of parasites appear to express a particular SVSP protein. The fact that a number of SVSPs contain functional nuclear localisation signals suggests that proteins released from the parasite could contribute to phenotypic changes of the host cell. This initial characterisation will facilitate future studies on the regulation of SVSP gene expression and the potential biological role of these enigmatic proteins
MCF-SMF Hybrid Low-Latency Circuit-Switched Optical Network for Disaggregated Data Centers
This paper proposes and experimentally evaluates a
fully developed novel architecture with purpose built low latency
communication protocols for next generation disaggregated data
centers (DDCs). In order to accommodate for capacity and
latency needs of disaggregated IT elements (i.e. CPU, memory),
this architecture makes use of a low latency and high capacity
circuit switched optical network for interconnecting various endpoints, that are equipped with multi-channel Silicon photonic
based integrated transceivers. In a move to further decrease the
perceived latency between various disaggregated IT elements,
this paper proposes a) a novel network topology, which cuts
down the latency over the optical network by 34% while
enhancing system scalability and b) channel bonding over multicore fiber (MCF) switched links to reduce head to tail latency
and in turn increase sustained memory bandwidth for
disaggregated remote memory. Furthermore, to reduce power
consumption and enhance space efficiency, the integration of
novel multi core fiber (MCF) based transceivers, fibers and
optical switches are proposed and experimentally validated at the
physical layer for this topology. It is shown that the integration of
MCF based subsystems in this topology can bring about an
improvement in energy efficiency of the optical switching layer
which is above 60%. Finally, the performance of this proposed
architecture and topology is evaluated experimentally at the
application layer where the perceived memory throughput for
accessing remote and local resources is measured and compared
using electrical circuit and packet switching. The results also
highlight a multi fold increase in application perceived memory
throughput over the proposed DDC topology by utilization and
bonding of multiple optical channels to interconnect
disaggregated IT elements that can be carried over MCF links
Dietary treatment in phenylketonuria does not lead to increased risk of obesity or metabolic syndrome
Combination of inoculation methods of Azospirilum brasilense with broadcasting of nitrogen fertilizer increases corn yield
A CalderĂłn multiplicative preconditioner for the electromagnetic PoincarĂ©âSteklov operator of a heterogeneous domain with scattering applications
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