1,806 research outputs found
Population-based Cohort Studies on Premorbid Cognitive Function in Schizophrenia
Many previous studies have found associations between poor cognitive function and schizophrenia. However, the majority of these studies used retrospective data, leading to the possibility of selection and recall biases. Retrospective studies are also unable to distinguish whether cognitive deficits exist prior to the onset of schizophrenia, suggesting that they are important in etiology, or following onset, suggesting that they are secondary to the disorder or its treatment. The current review used a systematic search strategy to identify and summarize the results of all studies that have used population-based cohorts to examine associations between prospectively collected data on premorbid cognitive functioning in childhood or adolescence and subsequent risk for schizophrenia. Three broad categories of study have addressed these questions: birth cohort designs with cognitive testing during childhood, army conscript designs with cognitive performance measured at conscription, and studies using school grades. Birth cohort and conscript studies are consistent in reporting strong associations between poor performance on cognitive batteries and increased risk of schizophrenia. Studies on school performance have been less consistent, although the largest such study showed strong associations across all school subjects. In conclusion, children and adolescents with poor cognitive abilities in childhood are at increased risk of schizophrenia. This suggests that poor cognitive function is either directly causal or associated with causal factors that are involved in etiology. adolescent development; child development; cohort studies; intelligence; learning disorders; review; schizophrenia Abbreviation: IQ, intelligence quotient
Pulsed excitation dynamics of an optomechanical crystal resonator near its quantum ground-state of motion
Using pulsed optical excitation and read-out along with single phonon
counting techniques, we measure the transient back-action, heating, and damping
dynamics of a nanoscale silicon optomechanical crystal cavity mounted in a
dilution refrigerator at a base temperature of 11mK. In addition to observing a
slow (~740ns) turn-on time for the optical-absorption-induced hot phonon bath,
we measure for the 5.6GHz `breathing' acoustic mode of the cavity an initial
phonon occupancy as low as 0.021 +- 0.007 (mode temperature = 70mK) and an
intrinsic mechanical decay rate of 328 +- 14 Hz (mechanical Q-factor =
1.7x10^7). These measurements demonstrate the feasibility of using short pulsed
measurements for a variety of quantum optomechanical applications despite the
presence of steady-state optical heating.Comment: 16 pages, 6 figure
Network acceleration techniques
Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP)
10-100 Gbps Offload NIC for WAN, NLR, and Grid Computing
An extremely fast offload engine system has been developed that operates at 60 Gigabits per second (Gbps), and has scalability to 100 Gbps full-duplex (f-d). This system is based on unique coding and architecture derived from splintered UDP (User Datagram Protocol) offload technology, resulting in unique FPGA (field programmable gate array) intellectual property core and firmware. This innovation improves the networking speed of supercomputer clusters by providing an ultra-fast network protocol processing offload from a CPU (central processing unit) by inserting an offload engine into a host backplane and network connections. This runs on protocol firmware
Geometrical Aspect of Topologically Twisted 2-Dimensional Conformal Superalgebra
We study the topologically twisted osp(2|2)+osp(2|2) conformal superalgebra.
The algebra includes the Lagrangians which are intrinsic to the topological
field theory and composed of fermionic generators. Studying the Lagrangians
through a gauge system of osp(2|2)+osp(2|2), geometrical features inherent to
the algebra are revealed: a moduli space associated with the algebra is derived
and the crucial roles which the fermionic generators play in the moduli space
are clarified It is argued that there exists a specific relation between the
topological twist and the moduli problem through a geometrical aspect of the
algebra.Comment: LaTeX, 33 pages, no figur
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