2,551 research outputs found
A Strategic Market Game with Seigniorage Costs of Fiat Money
A model that includes the cost of producing money is presented and the nature of the inefficient equilibria in the model are examined. It is suggested that if one acknowledges that transactions are a form of production, which requires the consumption resources, then the concept of Pareto optimality is inappropriate for assessing efficiency. Instead it becomes necessary to provide an appropriate comparative analysis of alternative transactions mechanisms in the appropriate context.Strategic market games, Seigniorage costs, Inefficiency
Detecting heavy charged Higgs bosons at the LHC with triple b-tagging
We investigate the charged Higgs boson signal at the LHC using its dominant
production and decay modes with triple b-tagging, i.e. , followed by leptonic decay of one W and hadronic decay of
the other. We consider the continuum background from the associated production
of with a b- or a light quark or gluon jet, which can be mis-tagged
as b-jet. We reconstruct the top quark masses to identify the 3rd b-jet
accompanying the pair, and use its p_T distribution to distinguish
the signal from the background. Combining this with the reconstruction of the
mass gives a viable signature over two interesting regions of the
parameter space - i.e. and .Comment: 10 pages, latex, 4 figure
Space-Frequency Equalization for Broadband Single Carrier MIMO Systems
In this paper, a frequency domain (FD) receiver architecture implemented using estimated channel parameters is derived for broadband single carrier modulations. Co-channel and inter-symbol interferences are compensated by a minimum mean squared error based integrated space-frequency-equalizer (SFE) using the estimated parameters. The integrated SFE in the FD consists of coupled FIR structures, that are jointly optimized by maximizing the desired signal to interference plus noise ratio. We develop analytical expressions and present simulation results for the integrated SFE. Simulation results demonstrate that excellent receiver performance is achieved even for channels with large ISI spans. The proposed SC-SFE outperforms previous layered space frequency (LSF) receivers with imperfect channel knowledge. Further, the parallel receiver architecture yields equal diversity gains to all data streams without the error propagation that is common to most LSF schemes
Cooperative Relaying with CPFSK and Distributed Space-Time Trellis Codes
Cooperative relaying allows single antenna users to achieve diversity and coding gains by utilizing nearby users' transmitting capabilities. We consider a relay system employing constant envelope continuous phase frequency shift keying. Distributed space-time trellis codes are implemented with a novel multiple relay protocol
Improved Information Outage Rate in Certain MIMO Systems
We propose a simple class of encoding/decoding techniques which can be used to improve the information outage rate of certain multiple-input multiple-output (MIMO) systems. Gains in outage rate can be achieved at low to moderate signal to noise ratios in MIMO systems which have fewer receive antennas than transmit antennas. This performance improvement is due to extra ``virtual'' receive antennas which are created with low complexity signal processing. A simple space-time block code system using virtual receive antennas is also investigated
Two-user Cooperative Transmission Using Superposition Modulation and Soft Information Combining
We propose a cooperative transmission scheme for two users with one common relay using superposition modulation. It uses distributed Turbo codes (DTCs) for each user. The relay always decodes, then interleaves and re-encodes the decoded
data. A new packet is formed by combining the re-encoded packets from both users using superposition modulation. This packet is forwarded to the destination with the average receive SNRs of each user. The destination uses the cooperative Turbo
decoder of [1] to improve performance. Simulation results show the proposed scheme outperforms XOR based schemes and is simple to implement
Cooperative Relaying with CPFSK and Distributed Space-Time Trellis Codes
Cooperative relaying allows single antenna users to achieve diversity and coding gains by utilizing nearby users' transmitting capabilities. We consider a relay system employing constant envelope continuous phase frequency shift keying. Distributed space-time trellis codes are implemented with a novel multiple relay protocol
Absence of the cbb3 terminal oxidase reveals an active oxygen-dependent cyclase involved in bacteriochlorophyll biosynthesis in Rhodobacter sphaeroides.
The characteristic green color associated with chlorophyll pigments results from the formation of an isocyclic fifth ring on the tetrapyrrole macrocyle during the biosynthesis of these important molecules. This reaction is catalyzed by two unrelated cyclase enzymes employing different chemistries. Oxygenic phototrophs such as plants and cyanobacteria utilize an oxygen-dependent enzyme, the major component of which is a diiron protein named AcsF, while BchE, an oxygen-sensitive [4Fe-4S] cluster protein, dominates in phototrophs inhabiting anoxic environments, such as the purple phototrophic bacterium Rhodobacter sphaeroides We identify a potential acsF in this organism and assay for activity of the encoded protein in a strain lacking bchE under various aeration regimes. Initially, cells lacking bchE did not demonstrate AcsF activity under any condition tested. However, on removal of a gene encoding a subunit of the cbb3-type respiratory terminal oxidase, cells cultured under regimes ranging from oxic to microoxic exhibited cyclase activity, confirming the activity of the oxygen-dependent enzyme in this model organism. Potential reasons for the utilization of an oxygen-dependent enzyme in anoxygenic phototrophs are discussed. IMPORTANCE: The formation of the E ring of (bacterio)chlorophyll pigments is the least well-characterized step in their biosynthesis, remaining enigmatic for over 60 years. Two unrelated enzymes catalyze this cyclization step; O2-dependent and O2-independent forms dominate in oxygenic and anoxygenic phototrophs, respectively. We uncover the activity of an O2-dependent enzyme in the anoxygenic purple phototrophic bacterium Rhodobacter sphaeroides, initially by inactivation of the high affinity terminal respiratory oxidase, cytochrome cbb3 We propose that the O2-dependent form allows for the biosynthesis of a low level of bacteriochlorophyll under oxic conditions, so that a rapid initiation of photosynthetic processes is possible for this bacterium upon a reduction of oxygen tension
Evaluation of two lyophilized molecular assays to rapidly detect foot-and-mouth disease virus directly from clinical samples in field settings
Accurate, timely diagnosis is essential for the control, monitoring and eradication of footâandâmouth disease (FMD). Clinical samples from suspect cases are normally tested at reference laboratories. However, transport of samples to these centralized facilities can be a lengthy process that can impose delays on critical decision making. These concerns have motivated work to evaluate simpleâtoâuse technologies, including molecularâbased diagnostic platforms, that can be deployed closer to suspect cases of FMD. In this context, FMD virus (FMDV)âspecific reverse transcription loopâmediated isothermal amplification (RTâLAMP) and realâtime RTâPCR (rRTâPCR) assays, compatible with simple sample preparation methods and in situ visualization, have been developed which share equivalent analytical sensitivity with laboratoryâbased rRTâPCR. However, the lack of robust âreadyâtoâuse kitsâ that utilize stabilized reagents limits the deployment of these tests into field settings. To address this gap, this study describes the performance of lyophilized rRTâPCR and RTâLAMP assays to detect FMDV. Both of these assays are compatible with the use of fluorescence to monitor amplification in realâtime, and for the RTâLAMP assays end point detection could also be achieved using molecular lateral flow devices. Lyophilization of reagents did not adversely affect the performance of the assays. Importantly, when these assays were deployed into challenging laboratory and field settings within East Africa they proved to be reliable in their ability to detect FMDV in a range of clinical samples from acutely infected as well as convalescent cattle. These data support the use of highly sensitive molecular assays into field settings for simple and rapid detection of FMDV
The vector-valued big q-Jacobi transform
Big -Jacobi functions are eigenfunctions of a second order -difference
operator . We study as an unbounded self-adjoint operator on an
-space of functions on with a discrete measure. We describe
explicitly the spectral decomposition of using an integral transform
with two different big -Jacobi functions as a kernel, and we
construct the inverse of .Comment: 35 pages, corrected an error and typo
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