101,385 research outputs found
Differences in ultrasound-derived arterial wall stiffness parameters and noninvasive blood pressure between Friesian horses and Warmblood horses
Background: Aortic rupture is more common in Friesians compared to Warmbloods, which might be related to differences in arterial wall composition and, as such, arterial wall stiffness (AWS). Currently, nothing is known about differences in AWS between these breeds.
Objectives: Comparison of AWS parameters and noninvasive blood pressure between Friesians and Warmbloods.
Animals: One hundred one healthy Friesians and 101 age-matched healthy Warmbloods.
Methods: Two-dimensional and pulsed-wave Doppler ultrasound examination was performed of the aorta, common carotid artery, and external iliac artery to define local and regional AWS parameters. Regional aortic AWS was estimated using aortic-to-external iliac artery pulse wave velocity (PWVa-e) and carotid-to-external iliac artery pulse wave velocity (PWVc-e). Noninvasive blood pressure and heart rate were recorded simultaneously.
Results: Systolic, diastolic, and mean arterial blood pressure and pulse pressure were significantly higher in Friesians compared to Warmbloods. No significant difference in heart rate was found. Most local AWS parameters (diameter change, compliance coefficient, distensibility coefficient) were significantly lower in Friesians compared to Warmbloods, indicating a stiffer aorta in Friesians. This difference could be confirmed by the regional stiffness parameters. A higher PWVa-e and PWVc-e was found in Friesians. For the cranial and caudal common carotid artery and external iliac artery, most local AWS parameters were not significantly different.
Conclusions and clinical importance: Results indicate that aortic AWS differs between Friesian and Warmblood horses. Friesians seem to have a stiffer aorta, which might be related to the higher incidence of aortic rupture in Friesians
Assessing the human factors risks in extending the use of AWS
The project reported in this paper was conducted on behalf of the Rail Safety and Standards Board, and formed part of the SPAD reduction and mitigation research theme. It sought to assess the Human Factors risks associated with extending the use of the in-cab Automatic Warning System (AWS). The term âExtended AWSâ refers to any situation where AWS is used other than to warn of the state of upcoming signals. This includes uses for permanent, temporary and emergency speed restrictions, certain level crossings, and, potentially, multi-SPAD signals. The paper summarises the work performed in the study. It considers new areas of psychological investigation believed to be important for driver related research, the methods used to gather and analyse industry experience, and concludes by examining the risk of drivers failing to behave appropriately to AWS warnings
Design and implementation of MIMO-long term evolution-advanced to support larger bandwidth
The migration of mobile communication technologies are divided into four generations.
Long Term Evolution (LTE) is called LTE rel-8, the evolution of LTE led to new
technology referred to as LTE-Advanced, is the true fourth generation (4G) evolution
step, with the first release of LTE (rel-8) which was labeled as â3.9Gâ. LTE-Advanced
is a mobile broadband access technology founded as a response to the need for the
improvement to support the increasing demand for high data rates. The standard for
LTE-A is a milestone in the development of Third Generation Partnership Project
(3GPP) technologies. Carrier Aggregation is one of the most distinct features of LTEïżœAdvanced that makes the bandwidth extension of up to 100 MHz thus the theoretical
peak data rate of LTE-A may be even up to 1 Gbps. This proposed system presents new
LTE-Advanced depending on carrier aggregation to obtain better performance of the
system. The new design of LTE-Advanced offers higher peak data rates than even the
initial LTE-A; while the spectrum efficiency has been amended; As a result, the
aggregated LTE-A will support 120 MHz instead of 100 MHz in order to obtain higher
peak data rate access up to 4 Gbps. The system was applied with 8x8 Multiple Input
Multiple Output (MIMO) using different modulation techniques: QPSK, 16 QAM, and
64 QAM. From the simulation results, it is clear that proposed LTE-Advanced with 64
QAM has high values of throughput in case of depending code rate equals to 5/6 with
8x8 MIMO
Synthesizing Coupling Proofs of Differential Privacy
Differential privacy has emerged as a promising probabilistic formulation of
privacy, generating intense interest within academia and industry. We present a
push-button, automated technique for verifying -differential
privacy of sophisticated randomized algorithms. We make several conceptual,
algorithmic, and practical contributions: (i) Inspired by the recent advances
on approximate couplings and randomness alignment, we present a new proof
technique called coupling strategies, which casts differential privacy proofs
as a winning strategy in a game where we have finite privacy resources to
expend. (ii) To discover a winning strategy, we present a constraint-based
formulation of the problem as a set of Horn modulo couplings (HMC) constraints,
a novel combination of first-order Horn clauses and probabilistic constraints.
(iii) We present a technique for solving HMC constraints by transforming
probabilistic constraints into logical constraints with uninterpreted
functions. (iv) Finally, we implement our technique in the FairSquare verifier
and provide the first automated privacy proofs for a number of challenging
algorithms from the differential privacy literature, including Report Noisy
Max, the Exponential Mechanism, and the Sparse Vector Mechanism
Artificial Wombs, Birth, and "Birth": A Response to Romanis
Recently, I argued that human subjects in artificial wombs (AWs) âshare the same moral status as newbornsâ and so, deserve the same treatment and protections as newborns. This thesis rests on two claims:
(A) âSubjects of partial ectogenesisâthose that develop in utero for at time before being transferred to AWsâare newborns,â and
(B) âSubjects of complete ectogenesisâthose who develop in AWs entirelyâshare the same moral status as newborns.â
In response, Elizabeth Chloe Romanis argued that the subject in an AW is âa unique human entityâŠrather than a fetus or a newborn.â She provides four lines of response to my essay. First, she argues that I have âmisconstruedâ what birth is. Once we correct that error, it becomes clear that subjects of partial ectogenesis have not been born. Second, she argues that my claims imply that non-implanted embryos (existing in vivo) âwould also be âborn.ââ But that is absurd. Third, she claims I fail to âmeaningfully respondâ to distinctions she draws between subjects of ectogenesis and neonates. Finally, she criticizes my essay for focusing on subjects of AWs rather than focusing on pregnant persons (who should be at the âcentreâ of debates over AWs). I respond to each of these charges. In doing so, I reaffirm that (contra Romanis) some subjects of ectogenesis are newborns and all subjects of ectogenesisâeven those that have not been bornâshare the same moral status as newborns
Jumping the Queue: From NASA to the Commercial Cloud
NASA's High-End Computing Capability (HECC) Project has made it possible for its users to run on commercial cloud resources in a seamless way. In the first of three phases, we implemented a pilot project for a few users, enabling them to jump the queue and burst jobs from the HECC environment to Amazon Web Services (AWS). By using GPU-accelerated nodes at AWS, the users were able to make significant advances in their research. The second phase of the project made AWS access available to all HECC users and added accounting to make users responsible for cloud charges. We are also enabling export-controlled work through the use of AWS GovCloud. In the third phase, we will add web-based mechanisms to permit non-HECC users to access cloud resources for their HPC projects
Proton Heating in Solar Wind Compressible Turbulence with Collisions between Counter-propagating Waves
Magnetohydronamic turbulence is believed to play a crucial role in heating
the laboratorial, space, and astrophysical plasmas. However, the precise
connection between the turbulent fluctuations and the particle kinetics has not
yet been established. Here we present clear evidence of plasma turbulence
heating based on diagnosed wave features and proton velocity distributions from
solar wind measurements by the Wind spacecraft. For the first time, we can
report the simultaneous observation of counter-propagating magnetohydrodynamic
waves in the solar wind turbulence. Different from the traditional paradigm
with counter-propagating Alfv\'en waves, anti-sunward Alfv\'en waves (AWs) are
encountered by sunward slow magnetosonic waves (SMWs) in this new type of solar
wind compressible turbulence. The counter-propagating AWs and SWs correspond
respectively to the dominant and sub-dominant populations of the imbalanced
Els\"asser variables. Nonlinear interactions between the AWs and SMWs are
inferred from the non-orthogonality between the possible oscillation direction
of one wave and the possible propagation direction of the other. The associated
protons are revealed to exhibit bi-directional asymmetric beams in their
velocity distributions: sunward beams appearing in short and narrow patterns
and anti-sunward broad extended tails. It is suggested that multiple types of
wave-particle interactions, i.e., cyclotron and Landau resonances with AWs and
SMWs at kinetic scales, are taking place to jointly heat the protons
perpendicularly and parallel
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