4,204 research outputs found
A Similarity Measure for GPU Kernel Subgraph Matching
Accelerator architectures specialize in executing SIMD (single instruction,
multiple data) in lockstep. Because the majority of CUDA applications are
parallelized loops, control flow information can provide an in-depth
characterization of a kernel. CUDAflow is a tool that statically separates CUDA
binaries into basic block regions and dynamically measures instruction and
basic block frequencies. CUDAflow captures this information in a control flow
graph (CFG) and performs subgraph matching across various kernel's CFGs to gain
insights to an application's resource requirements, based on the shape and
traversal of the graph, instruction operations executed and registers
allocated, among other information. The utility of CUDAflow is demonstrated
with SHOC and Rodinia application case studies on a variety of GPU
architectures, revealing novel thread divergence characteristics that
facilitates end users, autotuners and compilers in generating high performing
code
Epstein-Barr virus infections and DNA hybridization studies in posttransplantation lymphoma and lymphoproliferative lesions: The role of primary infection
Fourteen patients who developed B cell lymphomas or lymphoproliferative lesions after kidney, liver, heart, or heart-lung transplantation in Pittsburgh during 1981-1983 had active infection with Epstein-Barr virus (EBV)of the primary (six patients), reactivated (seven patients), or chronic (one patient) type. In transplant patients without tumors, the incidence of EBV infection was 30% (39 of 128). Only three of these patients had primary infections. Thus the frequency of active infection was significantly higher in patients with tumors, and patients with primary infections were at greater risk of developing tumors. Five of 13 tumors tested contained EBV nuclear antigen (EBNA) and nine of 11 contained EBV genomes detected by DNA-DNA hybridization with BamHI K, BamHI W, or EcoRI B cloned probes. All EBNA-positive tumors, except one, were also positive by hybridization. Only one tumor was negative for both EBNA and EBV DNA. These data suggest that EBV plays an etiologic role in the development of these lesions. © 1985 by The University of Chicago
A Philosophy for Developing Trust in Self-driving Cars
For decades, our lives have depended on the safe operation of automated mech-anisms around and inside us. The autonomy and complexity of these mechanisms is increasing dramatically. Autonomous systems such as self-driving cars rely heavily on inductive inference and complex software, both of which confound tra-ditional software-safety techniques that are focused on amassing sufficient con-firmatory evidence to support safety claims. In this paper we survey existing methods and tools that, taken together, can enable a new and more productive phi-losophy for software safety that is based on Karl Popperâs idea of falsificationism. 1 Trusting self-driving cars For decades, our lives have depended on the safe operation of automated mech-anisms around and inside us. However, the autonomy of these mechanisms is in-creasing dramatically, going from comparatively simple drive-by-wire control to fully autonomous self-driving cars. The safety risks posed by autonomous systems cannot be mitigated through mechanical interlocks or similar tried-and-true tech
Pulmonary stretch receptor activity during partial liquid ventilation in cats with healthy lungs
Aim: To study whether pulmonary stretch receptor (PSR) activity in mechanically ventilated young cats with healthy lungs during partial liquid ventilation (PLV) is different from that during gas ventilation (GV). Methods: In 10 young cats (4.4 +/- 0.4 months, 2.3 +/- 0.3 kg; mean B SD), PSR instantaneous impulse frequency (PSR f(imp)) was recorded from single fibres in the vagal nerve during GV and PLV with perfluorocarbon (30 ml/kg) at increasing positive inspiratory pressures (PIP; 1.2, 1.8, 2.2 and 2.7 kPa), and at a positive end-expiratory pressure of 0.5 kPa. Results: All PSRs studied during GV maintained their phasic character with increased impulse frequency during inspiration during PLV. Peak PSR fimp was lower at PIP 1.2 kPa (p < 0.05) and at PIP 2.7 kPa (p = 0.10) during PLV than during GV, giving a lower number of PSR impulses at these two settings during PLV (p < 0.05). Conclusion: The phasic character of PSR activity is similar during GV and PLV. PSR activity is not higher during PLV than during GV in cats with healthy lungs, indicating no extensive stretching of the lung during PLV. Copyright (C) 2004 S. Karger AG, Basel
Anarchy in the UK: Detailed genetic analysis of worker reproduction in a naturally occurring British anarchistic honeybee, Apis mellifera, colony using DNA microsatellites
Anarchistic behaviour is a very rare phenotype of honeybee colonies. In an anarchistic colony,
many workersâ sons are reared in the presence of the queen. Anarchy has previously
been described in only two Australian colonies. Here we report on a first detailed genetic
analysis of a British anarchistic colony. Male pupae were present in great abundance above
the queen excluder, which was clearly indicative of extensive worker reproduction and is the
hallmark of anarchy. Seventeen microsatellite loci were used to analyse these male pupae,
allowing us to address whether all the males were indeed workersâ sons, and how many
worker patrilines and individual workers produced them. In the sample, 95 of 96 of the
males were definitely workersâ sons. Given that
â
1% of workersâ sons were genetically
indistinguishable from queenâs sons, this suggests that workers do not move any
queen-laid eggs between the part of the colony where the queen is present to the area above
the queen excluder which the queen cannot enter. The colony had 16 patrilines, with an
effective number of patrilines of 9.85. The 75 males that could be assigned with certainty to
a patriline came from 7 patrilines, with an effective number of 4.21. They were the offspring of at least 19 workers. This is in contrast to the two previously studied Australian naturally occurring anarchist colonies, in which most of the workersâ sons were offspring of one patriline. The high number of patrilines producing males leads to a low mean relatedness between laying workers and males of the colony. We discuss the importance of studying such colonies in the understanding of worker policing and its evolution
Integrative analyses identify modulators of response to neoadjuvant aromatase inhibitors in patients with early breast cancer
Introduction
Aromatase inhibitors (AIs) are a vital component of estrogen receptor positive (ER+) breast cancer treatment. De novo and acquired resistance, however, is common. The aims of this study were to relate patterns of copy number aberrations to molecular and proliferative response to AIs, to study differences in the patterns of copy number aberrations between breast cancer samples pre- and post-AI neoadjuvant therapy, and to identify putative biomarkers for resistance to neoadjuvant AI therapy using an integrative analysis approach.
Methods
Samples from 84 patients derived from two neoadjuvant AI therapy trials were subjected to copy number profiling by microarray-based comparative genomic hybridisation (aCGH, nâ=â84), gene expression profiling (nâ=â47), matched pre- and post-AI aCGH (nâ=â19 pairs) and Ki67-based AI-response analysis (nâ=â39).
Results
Integrative analysis of these datasets identified a set of nine genes that, when amplified, were associated with a poor response to AIs, and were significantly overexpressed when amplified, including CHKA, LRP5 and SAPS3. Functional validation in vitro, using cell lines with and without amplification of these genes (SUM44, MDA-MB134-VI, T47D and MCF7) and a model of acquired AI-resistance (MCF7-LTED) identified CHKA as a gene that when amplified modulates estrogen receptor (ER)-driven proliferation, ER/estrogen response element (ERE) transactivation, expression of ER-regulated genes and phosphorylation of V-AKT murine thymoma viral oncogene homolog 1 (AKT1).
Conclusions
These data provide a rationale for investigation of the role of CHKA in further models of de novo and acquired resistance to AIs, and provide proof of concept that integrative genomic analyses can identify biologically relevant modulators of AI response
Diagnosis and management of subcutaneous implantable cardioverterâdefibrillator infections based on process mapping
Background: Infection is a wellârecognized complication of cardiovascular implantable electronic device (CIED) implantation, including the more recently available subcutaneous implantable cardioverterâdefibrillator (SâICD). Although the AHA/ACC/HRS guidelines include recommendations for SâICD use, currently there are no clinical trial data that address the diagnosis and management of SâICD infections. Therefore, an expert panel was convened to develop consensus on these topics. /
Methods: A process mapping methodology was used to achieve a primary goal â the development of consensus on the diagnosis and management of SâICD infections. Two faceâtoâface meetings of panel experts were conducted to recommend useful information to clinicians in individual patient management of SâICD infections. /
Results: Panel consensus of a stepwise approach in the diagnosis and management was developed to provide guidance in individual patient management. /
Conclusion: Achieving expert panel consensus by process mapping methodology in SâICD infection diagnosis and management was attainable, and the results should be helpful in individual patient management
Audit of the change in the on-call practices in neuroradiology and factors affecting it
BACKGROUND: On call practices had recently changed at the Newcastle General Hospital to accommodate increasing CT scan requests and reduce the workloads of the radiologists. In the new system, the person responsible for dealing with the out of hours requests for imaging changed from the neuroradiologist to the neuroradiographer. This audit was conducted to assess any change in the departmental workload as a result of this change. METHODS: The audit was carried out over a period of six months and data was collected from the on-call booklets which the neuroradiographers maintained and the log books maintained in the department of neuroradiology. Details of the imaging requested; the source of the request, the reason for the request and the results of the scans were recorded and analysed using Microsoft Excelâą. RESULTS: The number of CT scans requested from the A&E went up by 73.4% after the change in practice and majority of these increases were due to increased requests for scans on head injuries which increased by 122%. Although this was not statistically significant due to lack of study power, it is clinically relevant. CONCLUSION: The increase in the number of CT scans for head injuries reflects a general change in practice in management of head injuries in the UK. Changing the gatekeeper from radiologist to radiographer was associated with an increase in CT rate, particularly for head injuries. Other factors such as clinician seniority and a greater awareness of the NICE guidelines may have also contributed
Evidence for Superfluidity of Ultracold Fermions in an Optical Lattice
The study of superfluid fermion pairs in a periodic potential has important
ramifications for understanding superconductivity in crystalline materials.
Using cold atomic gases, various condensed matter models can be studied in a
highly controllable environment. Weakly repulsive fermions in an optical
lattice could undergo d-wave pairing at low temperatures, a possible mechanism
for high temperature superconductivity in the cuprates. The lattice potential
could also strongly increase the critical temperature for s-wave superfluidity.
Recent experimental advances in the bulk include the observation of fermion
pair condensates and high-temperature superfluidity. Experiments with fermions
and bosonic bound pairs in optical lattices have been reported, but have not
yet addressed superfluid behavior. Here we show that when a condensate of
fermionic atom pairs was released from an optical lattice, distinct
interference peaks appear, implying long range order, a property of a
superfluid. Conceptually, this implies that strong s-wave pairing and
superfluidity have now been established in a lattice potential, where the
transport of atoms occurs by quantum mechanical tunneling and not by simple
propagation. These observations were made for unitarity limited interactions on
both sides of a Feshbach resonance. For larger lattice depths, the coherence
was lost in a reversible manner, possibly due to a superfluid to insulator
transition. Such strongly interacting fermions in an optical lattice can be
used to study a new class of Hamiltonians with interband and atom-molecule
couplings.Comment: accepted for publication in Natur
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