6,643 research outputs found
Adaptive Transmission Techniques for Mobile Satellite Links
Adapting the transmission rate in an LMS channel is a challenging task
because of the relatively fast time variations, of the long delays involved,
and of the difficulty in mapping the parameters of a time-varying channel into
communication performance. In this paper, we propose two strategies for dealing
with these impairments, namely, multi-layer coding (MLC) in the forward link,
and open-loop adaptation in the return link. Both strategies rely on
physical-layer abstraction tools for predicting the link performance. We will
show that, in both cases, it is possible to increase the average spectral
efficiency while at the same time keeping the outage probability under a given
threshold. To do so, the forward link strategy will rely on introducing some
latency in the data stream by using retransmissions. The return link, on the
other hand, will rely on a statistical characterization of a physical-layer
abstraction measure.Comment: Presented at the 30th AIAA International Communications Satellite
Systems Conference (ICSSC), Ottawa, Canada, 2012. Best Professional Paper
Awar
Commercialization of the land remote sensing system: An examination of mechanisms and issues
In September 1982 the Secretary of Commerce was authorized (by Title II of H.R. 5890 of the 97th Congress) to plan and provide for the management and operation of the civil land remote sensing satellite systems, to provide for user fees, and to plan for the transfer of the ownership and operation of future civil operational land remote sensing satellite systems to the private sector. As part of the planning for transfer, a number of approaches were to be compared including wholly private ownership and operation of the system by an entity competitively selected, mixed government/private ownership and operation, and a legislatively-chartered privately-owned corporation. The results of an analysis and comparison of a limited number of financial and organizational approaches for either transfer of the ownership and operation of the civil operational land remote sensing program to the private sector or government retention are presented
Research Review: Neural response to threat in children, adolescents, and adults after child maltreatment – a quantitative meta‐analysis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136280/1/jcpp12651_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136280/2/jcpp12651.pd
Evaluating Midwifery Units (EMU): A prospective cohort study of freestanding midwifery units in New South Wales, Australia
© 2014, BMJ Publishing Group. All rights reserved. Objective: To compare maternal and neonatal birth outcomes and morbidities associated with the intention to give birth in two freestanding midwifery units and two tertiary-level maternity units in New South Wales, Australia. Design: Prospective cohort study. Participants: 494 women who intended to give birth at freestanding midwifery units and 3157 women who intended to give birth at tertiary-level maternity units. Participants had low risk, singleton pregnancies and were at less than 28+0 weeks gestation at the time of booking. Primary and secondary outcome measures: Primary outcomes were mode of birth, Apgar score of less than 7 at 5 min and admission to the neonatal intensive care unit or special care nursery. Secondary outcomes were onset of labour, analgesia, blood loss, management of third stage of labour, perineal trauma, transfer, neonatal resuscitation, breastfeeding, gestational age at birth, birth weight, severe morbidity and mortality. Results: Women who planned to give birth at a freestanding midwifery unit were significantly more likely to have a spontaneous vaginal birth (AOR 1.57; 95% CI 1.20 to 2.06) and significantly less likely to have a caesarean section (AOR 0.65; 95% CI 0.48 to 0.88). There was no significant difference in the AOR of 5 min Apgar scores, however, babies from the freestanding midwifery unit group were significantly less likely to be admitted to neonatal intensive care or special care nursery (AOR 0.60; 95% CI 0.39 to 0.91). Analysis of secondary outcomes indicated that planning to give birth in a freestanding midwifery unit was associated with similar or reduced odds of intrapartum interventions and similar or improved odds of indicators of neonatal well-being. Conclusions: The results of this study support the provision of care in freestanding midwifery units as an alternative to tertiary-level maternity units for women with low risk pregnancies at the time of booking
Weighted network modules
The inclusion of link weights into the analysis of network properties allows
a deeper insight into the (often overlapping) modular structure of real-world
webs. We introduce a clustering algorithm (CPMw, Clique Percolation Method with
weights) for weighted networks based on the concept of percolating k-cliques
with high enough intensity. The algorithm allows overlaps between the modules.
First, we give detailed analytical and numerical results about the critical
point of weighted k-clique percolation on (weighted) Erdos-Renyi graphs. Then,
for a scientist collaboration web and a stock correlation graph we compute
three-link weight correlations and with the CPMw the weighted modules. After
reshuffling link weights in both networks and computing the same quantities for
the randomised control graphs as well, we show that groups of 3 or more strong
links prefer to cluster together in both original graphs.Comment: 19 pages, 7 figure
OVERCOMING BIOFILM MEDIATED RESPIRATORY INFECTIONS THROUGH EXPLOITATION OF PATHOGEN AND HOST-DIRECTED NOVEL PEPTIDES
Hereditary predisposition to ovarian cancer, looking beyond BRCA1/BRCA2
AbstractObjectiveGenetic predisposition to ovarian cancer is well documented. With the advent of next generation sequencing, hereditary panel testing provides an efficient method for evaluating multiple genes simultaneously. Therefore, we sought to investigate the contribution of 19 genes identified in the literature as increasing the risk of hereditary breast and ovarian cancer (HBOC) in a BRCA1 and BRCA2 negative population of patients with a personal history of breast and/or ovarian cancer by means of a hereditary cancer panel.MethodsSubjects were referred for multi-gene panel testing between February 2012 and March 2014. Clinical data was ascertained from requisition forms. The incidence of pathogenic mutations (including likely pathogenic), and variant of unknown significance were then calculated for each gene and/or patient cohort.ResultsIn this cohort of 911 subjects, panel testing identified 67 mutations. With 7.4% of subjects harboring a mutation on this multi-gene panel, the diagnostic yield was increased, compared to testing for BRCA1 and BRCA2 mutations alone. In the ovarian cancer probands, the most frequently mutated genes were BRIP1 (n=8; 1.72%) and MSH6 (n=6; 1.29%). In the breast cancer probands, mutations were most commonly observed in CHEK2 (n=9; 2.54%), ATM (n=3; 0.85%), and TP53 (n=3; 0.85%).ConclusionsAlthough further studies are needed to clarify the exact management of patients with a mutation in each gene, this study highlights information that can be captured with panel testing and provides support for incorporation of panel testing into clinical practice
Anterior knee pain from the evolutionary perspective
Background
This paper describes the evolutionary changes in morphology and orientation of the PFJ using species present through our ancestry over 340 million years.
Methods
37 specimens from the Devonian period to modern day were scanned using a 64-slice CT scanner. 3D geometries were created following routine segmentation and anatomical measurements taken from standardised bony landmarks.
Results
Findings are described according to gait strategy and age. The adoption of an upright bi-pedal stance caused a dramatic change in the loading of the PFJ which has subsequently led to changes in the arrangement of the PFJ. From Devonian to Miocene periods, our sprawling and climbing ancestors possessed a broad knee with a shallow, centrally located trochlea. A more rounded knee was present from the Paleolithic period onwards in erect and bipedal gait types (aspect ratio 0.93 vs 1.2 in late Devonian), with the PFJ being placed lateral to the midline compared to the medial position in quadrapeds. The depth of the trochlea groove was maximal in the Miocene period of the African ground apes with associated acute sulcus angles in Gorilla (117°) becoming more flattened towards the modern human (138°).
Conclusions
The evolving bipedal gait lead to anteriorisation of the patellofemoral joint, flattening of the trochlea sulcus, in a more lateral, dislocation prone arrangement. Ancestral developments might help explain the variety of presentations of anterior knee pain and patellofemoral instability
Interleukin 3 stimulates proliferation via protein kinase C activation without increasing inositol lipid turnover.
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