960 research outputs found
ALOHA With Collision Resolution(ALOHA-CR): Theory and Software Defined Radio Implementation
A cross-layer scheme, namely ALOHA With Collision Resolution (ALOHA-CR), is
proposed for high throughput wireless communications in a cellular scenario.
Transmissions occur in a time-slotted ALOHA-type fashion but with an important
difference: simultaneous transmissions of two users can be successful. If more
than two users transmit in the same slot the collision cannot be resolved and
retransmission is required. If only one user transmits, the transmitted packet
is recovered with some probability, depending on the state of the channel. If
two users transmit the collision is resolved and the packets are recovered by
first over-sampling the collision signal and then exploiting independent
information about the two users that is contained in the signal polyphase
components. The ALOHA-CR throughput is derived under the infinite backlog
assumption and also under the assumption of finite backlog. The contention
probability is determined under these two assumptions in order to maximize the
network throughput and maintain stability. Queuing delay analysis for network
users is also conducted. The performance of ALOHA-CR is demonstrated on the
Wireless Open Access Research Platform (WARP) test-bed containing five software
defined radio nodes. Analysis and test-bed results indicate that ALOHA-CR leads
to significant increase in throughput and reduction of service delays
Three-dimensional structure of the 67k N-terminal Fragment of E.coli DNA Topoisomerase I
No abstract availabl
Genetic algorithms as a new tool to study protein stability
No abstract availabl
Dynamic Space Packing
Dynamic space packing (DSP) is a random process with sequential addition and
removal of identical objects into space. In the lattice version, objects are
particles occupying single lattice sites, and adding a particle to a lattice
site leads to the removal of particles on neighboring sites. We show that the
model is solvable and determine the steady-state occupancy, correlation
functions, desorption probabilities, and other statistical features for the DSP
of hyper-cubic lattices. We also solve a continuous DSP of balls into
.Comment: 24 pages, 8 figures; v3: small corrections, Appendix B and refs adde
Evaluation of erythrocyte membrane lipids and proteins in renal disorders
Background: Membrane lipids and proteins play a significant part in imparting membrane its rheological properties. These parameters are altered in diseased states. Exploring the conformational changes in renal disorders can widen our understanding of its impact on the circulatory system. This could lead to a new diagnostic parameter to study the progress of a disease.Methods: 120 blood samples collected from 30 kidney donors, 30 stage 3-4 Chronic kidney disease (CKD) patients (group 1) and 30 stage 5 CKD patients on dialysis (pre and post dialysis) (group 2) were lysed and washed to obtain erythrocyte ghost membranes. The proteins extracted from these membranes were estimated colorimetrically using Micro BCA kit. Phospholipids were separated and quantified using HPTLC. Fatty acids and cholesterol were analysed using GCMS.Results: The erythrocyte membrane protein profile showed lower values in group 2 participants than group 1 participants, but this difference was not significant. Distinct decreases in percentages of palmitic acid, myristic acid, stearic acid, dodecanoic acid, cholesterol, phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine were observed in both groups, with the lowest values in patients undergoing dialysis. Sphingomyelin and linoleic acid did not show any such trend across groups.Conclusions: The data is suggestive of an altered membrane structure in participants undergoing dialysis patients than the control group. This could be because of uremic toxins in the circulatory system affecting the membrane lipids. Decreased levels of essential phospholipids can impact the functions and lifespan of the erythrocytes. This could be a reason behind anaemia seen in most patients with CKD
Synthetic sequence generator for recommender systems - memory biased random walk on sequence multilayer network
Personalized recommender systems rely on each user's personal usage data in
the system, in order to assist in decision making. However, privacy policies
protecting users' rights prevent these highly personal data from being publicly
available to a wider researcher audience. In this work, we propose a memory
biased random walk model on multilayer sequence network, as a generator of
synthetic sequential data for recommender systems. We demonstrate the
applicability of the synthetic data in training recommender system models for
cases when privacy policies restrict clickstream publishing.Comment: The new updated version of the pape
Integrating Communication Skills and Planning Techniques
Practitioners have long stressed the need to teach professional commumcations skills to planning students. This paper describes ten years of experience in teaching a course in which communications skills and techniques of gathering and analyzing information are taught concurrently while investigating a problem of importance in the community. The course involves an ongoing collaboration, a "marriage of convenience," between an academic and a planner, casting city/county planning staff as clients for students This has proven useful for pedagogy and has had some positive impact on the community.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69149/2/10.1177_0739456X9201100206.pd
Dynamical fluctuations in the Riesz gas
We consider an infinite system of particles on a line performing identical
Brownian motions and interacting through the Riesz potential,
causing the over-damped motion of particles. We investigate fluctuations of the
integrated current and the position of a tagged particle. We show that for , the standard deviations of both quantities grow as
. When , the interactions are effectively
short-ranged, and the universal sub-diffusive growth emerges
with only amplitude depending on the exponent. We also show that the two-time
correlations of the tagged-particle position have the same form as for
fractional Brownian motion.Comment: 13 page
Complete Genome Sequence of Xanthomonas arboricola pv. juglandis 417, a Copper-Resistant Strain Isolated from Juglans regia L.
Here, we report the complete genome sequence of Xanthomonas arboricola pv. juglandis 417, a copper-resistant strain isolated from a blighted walnut fruit (Juglans regia L. cv. Chandler). The genome consists of a single chromosome (5,218 kb)
Genetic transformation of Vitis vinifera L. cvs Thompson Seedless and Chardonnay with the pear PGIP and GFP encoding genes
Transgenic plants of Vitis vinifera L. cvs. Chardonnay and Thompson Seedless expressing the β-glucuronidase gene (GUS) and either the pear polygalacturonase inhibiting protein gene (PGIP) or the green fluorescent protein gene (GFP) were produced via somatic embryogenesis. Various media and culture conditions were tested in order to develop an efficient transformation method. Best results were obtained when embryogenic callus was initiated from anthers cultured on PIV medium and maintained in PT medium. Embryogenic lines of the rootstocks Saint George, 110 Richter and Freedom and from inflorescence primordia of Chardonnay and 110 Richter were also established using the same media. Inoculation with 109 cells·ml-1 Agrobacterium resulted in a higher number of selected calli than cultures inoculated with 107 or 108 cells·ml-1. Plants were regenerated in a modified WP medium from up to 46 % of the selected callus. Approximately 80 % of the lines expressed GUS and either PGIP or GFP but a low correlation was found between β-glucuronidase and polygalacturonase inhibiting protein activities.
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