bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coupling proofs are probabilistic product programs
Authors: Barthe Gilles , Grégoire Benjamin , Hsu Justin , Strub Pierre-Yves 
Published: May 2017

Couplings are a powerful mathematical tool for reasoning about pairs of probabilistic processes. Recent developments in formal verification identify a close connection between couplings and pRHL, a relational program logic motivated by applications to provable security, enabling formal construction of couplings from the probability theory literature. However, existing work using pRHL merely shows existence of a coupling and does not give a way to prove quantitative properties about the coupling, needed to reason about mixing and convergence of probabilistic processes. Furthermore, pRHL is inherently incomplete, and is not able to capture some advanced forms of couplings such as shift couplings. We address both problems as follows.
First, we define an extension of pRHL, called x-pRHL, which explicitly constructs the coupling in a pRHL derivation in the form of a probabilistic product program that simulates two correlated runs of the original program. Existing verification tools for probabilistic programs can then be directly applied to the probabilistic product to prove quantitative properties of the coupling. Second, we equip x-pRHL with a new rule for while loops, where reasoning can freely mix synchronized and unsynchronized loop iterations. Our proof rule can capture examples of shift couplings, and the logic is relatively complete for deterministic programs.
We show soundness of x-PRHL and use it to analyze two classes of examples. First, we verify rapid mixing using different tools from coupling: standard coupling, shift coupling, and path coupling, a compositional principle for combining local couplings into a global coupling. Second, we verify (approximate) equivalence between a source and an optimized program for several instances of loop optimizations from the literature.
Approximate Storage of Compressed and Encrypted Videos
Authors: Jevdjic Djordje , Strauss Karin , Ceze Luis , Malvar Henrique S. 
Published: May 2017

The popularization of video capture devices has created strong storage demand for encoded videos. Approximate storage can ease this demand by enabling denser storage at the expense of occasional errors. Unfortunately, even minor storage errors, such as bit flips, can result in major visual damage in encoded videos. Similarly, video encryption, widely employed for privacy and digital rights management, may create long dependencies between bits that show little or no tolerance to storage errors.
In this paper we propose VideoApp, a novel and efficient methodology to compute bit-level reliability requirements for encoded videos by tracking visual and metadata dependencies within encoded bitstreams. We further show how VideoApp can be used to trade video quality for storage density in an optimal way. We integrate our methodology into a popular H.264 encoder to partition an encoded video stream into multiple streams that can receive different levels of error correction according to their reliability needs. When applied to a dense and highly error-prone multi-level cell storage substrate, our variable error correction mechanism reduces the error correction overhead by half under the most error-intolerant encoder settings, achieving quality/density points that neither compression nor approximation can achieve alone. Finally, we define the basic invariants needed to support encrypted approximate video storage. We present an analysis of block cipher modes of operation, showing that some are fully compatible with approximation, enabling approximate and secure video storage systems.
Breaking the Boundaries in Heterogeneous-ISA Datacenters
Authors: Barbalace Antonio , Lyerly Robert , Jelesnianski Christopher , Carno Anthony , Chuang Ho-Ren , Legout Vincent , Ravindran Binoy 
Published: May 2017

Energy efficiency is one of the most important design considerations in running modern datacenters. Datacenter operating systems rely on software techniques such as execution migration to achieve energy efficiency across pools of machines. Execution migration is possible in datacenters today because they consist mainly of homogeneous-ISA machines. However, recent market trends indicate that alternate ISAs such as ARM and PowerPC are pushing into the datacenter, meaning current execution migration techniques are no longer applicable. How can execution migration be applied in future heterogeneous-ISA datacenters?
In this work we present a compiler, runtime, and an operating system extension for enabling execution migration between heterogeneous-ISA servers. We present a new multi-ISA binary architecture and heterogeneous-OS containers for facilitating efficient migration of natively-compiled applications. We build and evaluate a prototype of our design and demonstrate energy savings of up to 66% for a workload running on an ARM and an x86 server interconnected by a high-speed network.
What Scalable Programs Need from Transactional Memory
Authors: Nguyen Donald , Pingali Keshav 
Published: May 2017

Transactional memory (TM) has been the focus of numerous studies, and it is supported in processors such as the IBM Blue Gene/Q and Intel Haswell. Many studies have used the STAMP benchmark suite to evaluate their designs. However, the speedups obtained for the STAMP benchmarks on all TM systems we know of are quite limited; for example, with 64 threads on the IBM Blue Gene/Q, we observe a median speedup of 1.4X using the Blue Gene/Q hardware transactional memory (HTM), and a median speedup of 4.1X using a software transactional memory (STM).
What limits the performance of these benchmarks on TMs? In this paper, we argue that the problem lies with the programming model and data structures used to write them. To make this point, we articulate two principles that we believe must be embodied in any scalable program and argue that STAMP programs violate both of them. By modifying the STAMP programs to satisfy both principles, we produce a new set of programs that we call the Stampede suite. Its median speedup on the Blue Gene/Q is 8.0X when using an STM. The two principles also permit us to simplify the TM design. Using this new STM with the Stampede benchmarks, we obtain a median speedup of 17.7X with 64 threads on the Blue Gene/Q and 13.2X with 32 threads on an Intel Westmere system.
These results suggest that HTM and STM designs will benefit if more attention is paid to the division of labor between application programs, systems software, and hardware.
Towards Practical Default-On Multi-Core Record/Replay
Authors: Mashtizadeh Ali José , Garfinkel Tal , Terei David , Mazieres David , Rosenblum Mendel 
Published: May 2017

We present Castor, a record/replay system for multi-core applications that provides consistently low and predictable overheads. With Castor, developers can leave record and replay on by default, making it practical to record and reproduce production bugs, or employ fault tolerance to recover from hardware failures.
Castor is inspired by several observations: First, an efficient mechanism for logging non-deterministic events is critical for recording demanding workloads with low overhead. Through careful use of hardware we were able to increase log throughput by 10x or more, e.g., we could record a server handling 10x more requests per second for the same record overhead. Second, most applications can be recorded without modifying source code by using the compiler to instrument language level sources of non-determinism, in conjunction with more familiar techniques like shared library interposition. Third, while Castor cannot deterministically replay all data races, this limitation is generally unimportant in practice, contrary to what prior work has assumed.
Castor currently supports applications written in C, C++, and Go on FreeBSD. We have evaluated Castor on parallel and server workloads, including a commercial implementation of memcached in Go, which runs Castor in production.
IncBricks
Authors: Liu Ming , Luo Liang , Nelson Jacob , Ceze Luis , Krishnamurthy Arvind , Atreya Kishore 
Published: May 2017

The emergence of programmable network devices and the increasing data traffic of datacenters motivate the idea of in-network computation. By offloading compute operations onto intermediate networking devices (e.g., switches, network accelerators, middleboxes), one can (1) serve network requests on the fly with low latency; (2) reduce datacenter traffic and mitigate network congestion; and (3) save energy by running servers in a low-power mode. However, since (1) existing switch technology doesn't provide general computing capabilities, and (2) commodity datacenter networks are complex (e.g., hierarchical fat-tree topologies, multipath communication), enabling in-network computation inside a datacenter is challenging.
In this paper, as a step towards in-network computing, we present IncBricks, an in-network caching fabric with basic computing primitives. IncBricks is a hardware-software co-designed system that supports caching in the network using a programmable network middlebox. As a key-value store accelerator, our prototype lowers request latency by over 30% and doubles throughput for 1024 byte values in a common cluster configuration. Our results demonstrate the effectiveness of in-network computing and that efficient datacenter network request processing is possible if we carefully split the computation across the different programmable computing elements in a datacenter, including programmable switches, network accelerators, and end hosts.
Identifying Security Critical Properties for the Dynamic Verification of a Processor
Authors: Zhang Rui , Stanley Natalie , Griggs Christopher , Chi Andrew , Sturton Cynthia 
Published: May 2017

We present a methodology for identifying security critical properties for use in the dynamic verification of a processor. Such verification has been shown to be an effective way to prevent exploits of vulnerabilities in the processor, given a meaningful set of security properties. We use known processor errata to establish an initial set of security-critical invariants of the processor. We then use machine learning to infer an additional set of invariants that are not tied to any particular, known vulnerability, yet are critical to security.We build a tool chain implementing the approach and evaluate it for the open-source OR1200 RISC processor. We find that our tool can identify 19 (86.4%) of the 22 manually crafted security-critical properties from prior work and generates 3 new security properties not covered in prior work.
Tissue Factor Prothrombotic Activity Is Regulated by Integrin-arf6 Trafficking
Authors: Rothmeier Andrea S. , Marchese Patrizia , Langer Florian , Kamikubo Yuichi , Schaffner Florence , Cantor Joseph , Ginsberg Mark H. , Ruggeri Zaverio M. , Ruf Wolfram 
Published: May 2017

Objective—
Coagulation initiation by tissue factor (TF) is regulated by cellular inhibitors, cell surface availability of procoagulant phosphatidylserine, and thiol-disulfide exchange. How these mechanisms contribute to keeping TF in a noncoagulant state and to generating prothrombotic TF remain incompletely understood.

Approach and Results—

Here, we study the activation of TF in primary macrophages by a combination of pharmacological, genetic, and biochemical approaches. We demonstrate that primed macrophages effectively control TF cell surface activity by receptor internalization. After cell injury, ATP signals through the purinergic receptor P2rx7 induce release of TF
+
microvesicles. TF cell surface availability for release onto microvesicles is regulated by the GTPase arf6 associated with integrin α4β1. Furthermore, microvesicles proteome analysis identifies activation of Gα
i2
as a participating factor in the release of microvesicles with prothrombotic activity in flowing blood. ATP not only prevents TF and phosphatidylserine internalization but also induces TF conversion to a conformation with high affinity for its ligand, coagulation factor VII. Although inhibition of dynamin-dependent internalization also exposes outer membrane procoagulant phosphatidylserine, the resulting TF
+
microvesicles distinctly lack protein disulfide isomerase and high affinity TF and fail to produce fibrin strands typical for microvesicles generated by thrombo-inflammatory P2rx7 activation.

Conclusions—
These data show that procoagulant phospholipid exposure is not sufficient and that TF affinity maturation is required to generate prothrombotic microvesicles from a variety of cell types. These findings are significant for understanding TF-initiated thrombosis and should be considered in designing functional microvesicles-based diagnostic approaches.
Management of Patients With Cardiac Arrest Complicating Myocardial Infarction in New York Before and After Public Reporting Policy Changes
Authors: Strom Jordan B. , McCabe James M. , Waldo Stephen W. , Pinto Duane S. , Kennedy Kevin F. , Feldman Dmitriy N. , Yeh Robert W. 
Published: May 2017

Background—
In 2010, New York State began excluding selected patients with cardiac arrest and coma from publicly reported mortality statistics after percutaneous coronary intervention. We evaluated the effects of this exclusion on rates of coronary angiography, revascularization, and mortality among patients with acute myocardial infarction and cardiac arrest.

Methods and Results—

Using statewide hospitalization files, we identified discharges for acute myocardial infarction and cardiac arrest January 2003 to December 2013 in New York and several comparator states. A difference-in-differences approach was used to evaluate the likelihood of coronary angiography, revascularization, and in-hospital mortality before and after 2010. A total of 26 379 patients with acute myocardial infarction and cardiac arrest (5619 in New York) were included. Of these, 17 141 (65%) underwent coronary angiography, 12 183 (46.2%) underwent percutaneous coronary intervention, and 2832 (10.7%) underwent coronary artery bypass grafting. Before 2010, patients with cardiac arrest in New York were less likely to undergo percutaneous coronary intervention compared with referent states (adjusted relative risk, 0.79; 95% confidence interval, 0.73–0.85;
P
<0.001). This relationship was unchanged after the policy change (adjusted relative risk, 0.82; 95% confidence interval, 0.76–0.89; interaction
P
=0.359). Adjusted risks of in-hospital mortality between New York and comparator states after 2010 were also similar (adjusted relative risk, 0.94; 95% confidence interval, 0.87–1.02;
P
=0.152 for post- versus pre-2010 in New York; adjusted relative risk, 0.88; 95% confidence interval, 0.84–0.92;
P
<0.001 for comparator states; interaction
P
=0.103).

Conclusions—
Exclusion of selected cardiac arrest cases from public reporting was not associated with changes in rates of percutaneous coronary intervention or in-hospital mortality in New York. Rates of revascularization in New York for cardiac arrest patients were lower throughout.
Hyperbaric Oxygen Reduces Infarction Volume and Hemorrhagic Transformation Through ATP/NAD
+
/Sirt1 Pathway in Hyperglycemic Middle Cerebral Artery Occlusion Rats
Authors: Hu Qin , Manaenko Anatol , Bian Hetao , Guo Zongduo , Huang Jun-Long , Guo Zhen-Ni , Yang Peng , Tang Jiping , Zhang John H. 
Published: May 2017

Background and Purpose—
Energy depletion is a critical factor leading to cell death and brain dysfunction after ischemic stroke. In this study, we investigated whether energy depletion is involved in hyperglycemia-induced hemorrhagic transformation after ischemic stroke and determined the pathway underlying the beneficial effects of hyperbaric oxygen (HBO).

Methods—
After 2-hour middle cerebral artery occlusion, hyperglycemia was induced by injecting 50% dextrose (6 mL/kg) intraperitoneally at the onset of reperfusion. Immediately after it, rats were exposed to HBO at 2 atmospheres absolutes for 1 hour. ATP synthase inhibitor oligomycin A, nicotinamide phosphoribosyl transferase inhibitor FK866, or silent mating type information regulation 2 homolog 1 siRNA was administrated for interventions. Infarct volume, hemorrhagic volume, and neurobehavioral deficits were recorded; the level of blood glucose, ATP, and nicotinamide adenine dinucleotide and the activity of nicotinamide phosphoribosyl transferase were monitored; the expression of silent mating type information regulation 2 homolog 1, acetylated p53, acetylated nuclear factor-κB, and cleaved caspase 3 were detected by Western blots; and the activity of matrix metalloproteinase-9 was assayed by zymography.

Results—
Hyperglycemia deteriorated energy metabolism and reduced the level of ATP and nicotinamide adenine dinucleotide and exaggerated hemorrhagic transformation, blood–brain barrier disruption, and neurological deficits after middle cerebral artery occlusion. HBO treatment increased the levels of the ATP and nicotinamide adenine dinucleotide and consequently increased silent mating type information regulation 2 homolog 1, resulting in attenuation of hemorrhagic transformation, brain infarction, as well as improvement of neurological function in hyperglycemic middle cerebral artery occlusion rats.

Conclusions—
HBO induced activation of ATP/nicotinamide adenine dinucleotide/silent mating type information regulation 2 homolog 1 pathway and protected blood–brain barrier in hyperglycemic middle cerebral artery occlusion rats. HBO might be promising approach for treatment of acute ischemic stroke patients, especially patients with diabetes mellitus or treated with r-tPA (recombinant tissue-type plasminogen activator).
Clinical Correlates, Ethnic Differences, and Prognostic Implications of Perivascular Spaces in Transient Ischemic Attack and Ischemic Stroke
Authors: Lau Kui-Kai , Li Linxin , Lovelock Caroline E. , Zamboni Giovanna , Chan Tsz-Tai , Chiang Man-Fung , Lo Kin-Ting , Küker Wilhelm , Mak Henry Ka-Fung , Rothwell Peter M. 
Published: May 2017

Background and Purpose—
Perivascular spaces (PVSs) are considered markers of small vessel disease. However, their long-term prognostic implications in transient ischemic attack/ischemic stroke patients are unknown. Ethnic differences in PVS prevalence are also unknown.

Methods—
Two independent prospective studies were conducted, 1 comprising predominantly whites with transient ischemic attack/ischemic stroke (OXVASC [Oxford Vascular] study) and 1 comprising predominantly Chinese with ischemic stroke (University of Hong Kong). Clinical and imaging correlates, prognostic implications for stroke and death, and ethnic differences in basal ganglia (BG) and centrum semiovale (CS) PVSs were studied with adjustment for age, sex, vascular risk factors, and scanner strength.

Results—

Whites with transient ischemic attack/ischemic stroke (n=1028) had a higher prevalence of both BG and CS-PVSs compared with Chinese (n=974; >20 BG-PVSs: 22.4% versus 7.1%; >20 CS-PVSs: 45.8% versus 10.4%;
P
<0.0001). More than 20 BG or CS-PVSs were both associated with increasing age and white matter hyperintensity, although associations with BG-PVSs were stronger (all
P
<0.0001). During 6924 patient-years of follow-up, BG-PVSs were also independently associated with an increased risk of recurrent ischemic stroke (adjusted hazard ratio compared with <11 PVSs, 11–20 PVSs: HR, 1.15; 95% confidence interval, 0.78–1.68; >20 PVSs: HR, 1.82; 1.18–2.80;
P
=0.011) but not intracerebral hemorrhage (
P
=0.10) or all-cause mortality (
P
=0.16). CS-PVSs were not associated with recurrent stroke (
P
=0.57) or mortality (
P
=0.072). Prognostic associations were similar in both cohorts.

Conclusions—
Over and above ethnic differences in frequency of PVSs in transient ischemic attack/ischemic stroke patients, BG and CS-PVSs had similar risk factors, but although >20 BG-PVSs were associated with an increased risk of recurrent ischemic stroke, CS-PVSs were not.
Statistical Downscaling of a High-Resolution Precipitation Reanalysis Using the Analog Ensemble Method
Authors: Keller Jan D. , Delle Monache Luca , Alessandrini Stefano 
Published: May 2017

AbstractThis study explores the first application of an analog-based method to downscale precipitation estimates from a regional reanalysis. The utilized analog ensemble (AnEn) approach defines a metric with which a set of analogs (i.e., the ensemble) can be sampled from the observations in the training period. From the determined AnEn estimates, the uncertainty of the generated precipitation time series also can easily be assessed. The study investigates tuning parameters of AnEn, such as the choice of predictors or the ensemble size, to optimize the performance. The approach is implemented and tuned on the basis of a set of over 700 rain gauges with 6-hourly measurements for Germany and a 6.2-km regional reanalysis for Europe, which provides the predictors. The obtained AnEn estimates are evaluated against the observations over a 4-yr verification period. With respect to deterministic quality, the results show that AnEn is able to outperform the reanalysis itself depending on location and precipitation intensity. Further, AnEn produces superior results in probabilistic measures against a random-ensemble approach as well as a logistic regression. As a proof of concept, the described implementation allows for the estimation of synthetic probabilistic observation time series for periods for which measurements are not available.
Tethered cord syndrome with spina bifida aperta in cats: two case reports of different types
Authors: Tamura Masahiro , Oji Takashi , Une Satoshi , Mukaino Makiko , Bekki Tatsuro , Tado Masaki , Koyama Hiromi , Kagawa Yumiko , Kawata Mutsumi 
Published: May 2017

Case summary Two castrated male cats, aged 8 months old (case 1) and 10 months old (case 2), showed a history of progressive paraparesis, an over-reaching pelvic limb gait, urinary incontinence and a palpable dermoid fistula. In case 1, the fistula was connected to the dural sac on the conus medullaris, and the tethered spinal cord was retracted caudally. In case 2, the tubular structure was connected to the dural sac on the thoracic spinal cord, and the tethered spinal cord was retracted dorsally. Tethered cord syndrome secondary to spina bifida aperta was suspected in both cats. Excision of the fistula and release of the tethered spinal cord was performed. A histopathological examination confirmed the diagnosis of a meningomyelocele in case 1 and a meningocele in case 2. Paraparesis improved postoperatively in both cats. However, urinary incontinence in case 1 remained partially unresolved. Relevance and novel information This is the first report to describe the imaging characteristics, surgical treatments and outcomes of two different types of tethered cord syndrome with spina bifida aperta in cats. Tethered cord syndrome with spina bifida aperta needs to be included in the differential diagnosis of slowly progressive paraparesis in younger cats with or without vesicorectal failure and a palpable dermoid fistula.