bluuebunny/crossref_metadata_2025 huggingface dataset:
InkTag
Authors: Hofmann Owen S. , Kim Sangman , Dunn Alan M. , Lee Michael Z. , Witchel Emmett
Published: July 2013

InkTag is a virtualization-based architecture that gives strong safety guarantees to high-assurance processes even in the presence of a malicious operating system. InkTag advances the state of the art in untrusted operating systems in both the design of its hypervisor and in the ability to run useful applications without trusting the operating system. We introduce
paraverification
, a technique that simplifies the InkTag hypervisor by forcing the untrusted operating system to participate in its own verification.
Attribute-based access control
allows trusted applications to create decentralized access control policies. InkTag is also the first system of its kind to ensure consistency between secure data and metadata, ensuring recoverability in the face of system crashes.
To hardware prefetch or not to prefetch?
Authors: Kang Hui , Wong Jennifer L.
Published: July 2013

Most hardware and software venders suggest disabling hardware prefetching in virtualized environments. They claim that prefetching is detrimental to application performance due to inaccurate prediction caused by workload diversity and VM interference on shared cache. However, no comprehensive or quantitative measurements to support this belief have been performed.

This paper is the first to systematically measure the influence of hardware prefetching in virtualized environments. We examine a wide variety of benchmarks on three types of chip-multiprocessors (CMPs) to analyze the hardware prefetching performance. We conduct extensive experiments by taking into account a number of important virtualization factors. We find that hardware prefetching has minimal destructive influence under most configurations. Only with certain application combinations does prefetching influence the overall performance.

To leverage these findings and make hardware prefetching effective across a diversity of virtualized environments, we propose a dynamic prefetching-aware VCPU-core binding approach (PAVCB), which includes two phases - classifying and binding. The workload of each VM is classified into different cache sharing constraint categories based upon its cache access characteristics, considering both prefetch requests and demand requests. Then following heuristic rules, the VCPUs of each VM are scheduled onto appropriate cores subject to cache sharing constraints. We show that the proposed approach can improve performance by 12% on average over the default scheduler and 46% over manual system administrator bindings across different workload combinations in the presence of hardware prefetching.
Practical automatic loop specialization
Authors: Oh Taewook , Kim Hanjun , Johnson Nick P. , Lee Jae W. , August David I.
Published: July 2013

Program specialization optimizes a program with respect to program invariants, including known, fixed inputs. These invariants can be used to enable optimizations that are otherwise unsound. In many applications, a program input induces predictable patterns of values across loop iterations, yet existing specializers cannot fully capitalize on this opportunity. To address this limitation, we present Invariant-induced Pattern based Loop Specialization (IPLS), the first fully-automatic specialization technique designed for everyday use on real applications. Using dynamic information-flow tracking, IPLS profiles the values of instructions that depend solely on invariants and recognizes repeating patterns across multiple iterations of hot loops. IPLS then specializes these loops, using those patterns to predict values across a large window of loop iterations. This enables aggressive optimization of the loop; conceptually, this optimization reconstructs recurring patterns induced by the input as concrete loops in the specialized binary. IPLS specializes real-world programs that prior techniques fail to specialize without requiring hints from the user. Experiments demonstrate a geomean speedup of 14.1% with a maximum speedup of 138% over the original codes when evaluated on three script interpreters and eleven scripts each.
Unikernels
Authors: Madhavapeddy Anil , Mortier Richard , Rotsos Charalampos , Scott David , Singh Balraj , Gazagnaire Thomas , Smith Steven , Hand Steven , Crowcroft Jon
Published: July 2013

We present
unikernels
, a new approach to deploying cloud services via applications written in high-level source code. Unikernels are single-purpose appliances that are compile-time specialised into standalone kernels, and sealed against modification when deployed to a cloud platform. In return they offer significant reduction in image sizes, improved efficiency and security, and should reduce operational costs. Our Mirage prototype compiles OCaml code into unikernels that run on commodity clouds and offer an order of magnitude reduction in code size without significant performance penalty. The architecture combines static type-safety with a single address-space layout that can be made immutable via a hypervisor extension. Mirage contributes a suite of type-safe protocol libraries, and our results demonstrate that the hypervisor is a platform that overcomes the hardware compatibility issues that have made past library operating systems impractical to deploy in the real-world.
Fine-grained fault tolerance using device checkpoints
Authors: Kadav Asim , Renzelmann Matthew J. , Swift Michael M.
Published: July 2013

Recovering faults in drivers is difficult compared to other code because their state is spread across both memory and a device. Existing driver fault-tolerance mechanisms either restart the driver and discard its state, which can break applications, or require an extensive logging mechanism to replay requests and recreate driver state. Even logging may be insufficient, though, if the semantics of requests are ambiguous. In addition, these systems either require large subsystems that must be kept up-to-date as the kernel changes, or require substantial rewriting of drivers.

We present a new driver fault-tolerance mechanism that provides fine-grained control over the code protected. Fine-Grained Fault Tolerance (FGFT) isolates driver code at the granularity of a single entry point. It executes driver code as a transaction, allowing roll back if the driver fails. We develop a novel checkpointing mechanism to save and restore device state using existing power management code. Unlike past systems, FGFT can be incrementally deployed in a single driver without the need for a large kernel subsystem, but at the cost of small modifications to the driver.

In the evaluation, we show that FGFT can have almost zero runtime cost in many cases, and that checkpoint-based recovery can reduce the duration of a failure by 79% compared to restarting the driver. Finally, we show that applying FGFT to a driver requires little effort, and the majority of drivers in common classes already contain the power-management code needed for checkpoint/restore.
FTL
2
Authors: Wang Tianzheng , Liu Duo , Wang Yi , Shao Zili
Published: July 2013

NAND flash memory has been widely used to build embedded devices such as smartphones and solid state drives (SSD) because of its high performance, low power consumption, great shock resistance and small form factor. However, its lifetime and performance are greatly constrained by partial page updates, which will lead to early depletion of free pages and frequent garbage collections. On the one hand, partial page updates are prevalent as a large portion of I/O does not modify file contents drastically. On the other hand, general-purpose cache usually does not specifically consider and eliminate duplicated contents, despite its popularity.

In this paper, we propose a hybrid approach called

FTL
2

, which employs both logging and mapping techniques in flash translation layer (FTL), to tackle the endurance problem and performance degradation caused by partial page updates in flash memory. FTL
2
logs the latest contents in a high-speed temporary storage, called
Content Cache
to handle partial page updates. Experimental results show that FTL
2
can greatly reduce page writes and postpone garbage collections with a small overhead.
Low cost control flow protection using abstract control signatures
Authors: Khudia Daya Shanker , Mahlke Scott
Published: July 2013

The continual trend of shrinking feature sizes and reducing voltage levels makes transistors faster and more efficient. However, it also makes them more susceptible to transient hardware faults. Transient faults due to high energy particle strikes or circuit crosstalk can corrupt the output of a program or cause it to crash. Previous studies have reported that as much as 70% of the transient faults disturb program control flow, making it critical to protect control flow. Traditional approaches employ signatures to check that every control flow transfer in a program is valid. While having high fault coverage, large performance overheads are introduced by such detailed checking. We propose a coarse-grain control flow checking method to detect transient faults in a cost effective way. Our software-only approach is centered on the principle of abstraction: control flow that exhibits simple run-time properties (e.g., proper path length) is almost always completely correct. Our solution targets off-the-shelf commodity embedded systems to provide a low cost protection against transient faults. The proposed technique achieves its efficiency by simplifying signature calculations in each basic block and by performing checking at a coarse-grain level. The coarse-grain signature comparison points are obtained by the use of a region based analysis. In addition, we propose a technique to protect control flow transfers via call and return instructions to ensure all control flow is covered by our technique. Overall, our proposed technique has an average of 11% performance overhead in comparison to 75% performance overhead of previously proposed signature based techniques while maintaining approximately the same degree of fault coverage.
Non-intrusive program tracing and debugging of deployed embedded systems through side-channel analysis
Authors: Moreno Carlos , Fischmeister Sebastian , Hasan M. Anwar
Published: July 2013

One of the hardest aspects of embedded software development is that of debugging, especially when faulty behavior is observed at the production or deployment stage. Non-intrusive observation of the system's behavior is often insufficient to infer the cause of the problem and identify and fix the bug. In this work, we present a novel approach for non-intrusive program tracing aimed at assisting developers in the task of debugging embedded systems at deployment or production stage, where standard debugging tools are usually no longer available. The technique is rooted in cryptography, in particular the area of side-channel attacks. Our proposed technique expands the scope of these cryptographic techniques so that we recover the sequence of operations from power consumption observations (power traces). To this end, we use digital signal processing techniques (in particular, spectral analysis) combined with pattern recognition techniques to determine blocks of source code being executed given the observed power trace. One of the important highlights of our contribution is the fact that the system works on a standard PC, capturing the power traces through the recording input of the sound card. Experimental results are presented and confirm that the approach is viable.
Asynchronous functional reactive programming for GUIs
Authors: Czaplicki Evan , Chong Stephen
Published: July 2013

Graphical user interfaces (GUIs) mediate many of our interactions with computers. Functional Reactive Programming (FRP) is a promising approach to GUI design, providing high-level, declarative, compositional abstractions to describe user interactions and time-dependent computations. We present Elm, a practical FRP language focused on easy creation of responsive GUIs. Elm has two major features: simple declarative support for
Asynchronous FRP
; and purely functional graphical layout.

Asynchronous FRP allows the programmer to specify when the global ordering of event processing can be violated, and thus enables efficient concurrent execution of FRP programs; long-running computation can be executed asynchronously and not adversely affect the responsiveness of the user interface.

Layout in Elm is achieved using a purely functional declarative framework that makes it simple to create and combine text, images, and video into rich multimedia displays.

Together, Elm's two major features simplify the complicated task of creating responsive and usable GUIs.
A general constraint-centric scheduling framework for spatial architectures
Authors: Nowatzki Tony , Sartin-Tarm Michael , De Carli Lorenzo , Sankaralingam Karthikeyan , Estan Cristian , Robatmili Behnam
Published: July 2013

Specialized execution using spatial architectures provides energy efficient computation, but requires effective algorithms for spatially scheduling the computation. Generally, this has been solved with architecture-specific heuristics, an approach which suffers from poor compiler/architect productivity, lack of insight on optimality, and inhibits migration of techniques between architectures.

Our goal is to develop a scheduling framework usable for all spatial architectures. To this end, we expresses spatial scheduling as a constraint satisfaction problem using Integer Linear Programming (ILP). We observe that architecture primitives and scheduler responsibilities can be related through five abstractions: placement of computation, routing of data, managing event timing, managing resource utilization, and forming the optimization objectives. We encode these responsibilities as 20 general ILP constraints, which are used to create schedulers for the disparate TRIPS, DySER, and PLUG architectures. Our results show that a general declarative approach using ILP is implementable, practical, and typically matches or outperforms specialized schedulers.
Scalable variable and data type detection in a binary rewriter
Authors: ElWazeer Khaled , Anand Kapil , Kotha Aparna , Smithson Matthew , Barua Rajeev
Published: July 2013

We present scalable static analyses to recover variables, data types, and function prototypes from stripped x86 executables (without symbol or debug information) and obtain a functional intermediate representation (IR) for analysis and rewriting purposes. Our techniques on average run 352X faster than current techniques and still have the same precision. This enables analyzing executables as large as millions of instructions in minutes which is not possible using existing techniques. Our techniques can recover variables allocated to the floating point stack unlike current techniques. We have integrated our techniques to obtain a compiler level IR that works correctly if recompiled and produces the same output as the input executable. We demonstrate scalability, precision and correctness of our proposed techniques by evaluating them on the complete SPEC2006 benchmarks suite.
Using managed runtime systems to tolerate holes in wearable memories
Authors: Gao Tiejun , Strauss Karin , Blackburn Stephen M. , McKinley Kathryn S. , Burger Doug , Larus James
Published: July 2013

New memory technologies, such as phase-change memory (PCM), promise denser and cheaper main memory, and are expected to displace DRAM. However, many of them experience permanent failures far more quickly than DRAM. DRAM mechanisms that handle permanent failures rely on very low failure rates and, if directly applied to PCM, are extremely inefficient: Discarding a page when the first line fails wastes 98% of the memory.

This paper proposes low complexity cooperative software and hardware that handle failure rates as high as 50%. Our approach makes error handling transparent to the application by using the memory abstraction offered by managed languages. Once hardware error correction for a memory line is exhausted, rather than discarding the entire page, the hardware communicates the failed line to a failure-aware OS and runtime. The runtime ensures memory allocations never use failed lines and moves data when lines fail during program execution. This paper describes minimal extensions to an Immix mark-region garbage collector, which correctly utilizes pages with failed physical lines by skipping over failures. This paper also proposes hardware support that clusters failed lines at one end of a memory region to reduce fragmentation and improve performance under failures. Contrary to accepted hardware wisdom that advocates for wear-leveling, we show that with software support non-uniform failures delay the impact of memory failure. Together, these mechanisms incur no performance overhead when there are no failures and at failure levels of 10% to 50% suffer only an average overhead of 4% and 12%}, respectively. These results indicate that hardware and software cooperation can greatly extend the life of wearable memories.
AutoSynch
Authors: Hung Wei-Lun , Garg Vijay K.
Published: July 2013

Most programming languages use monitors with explicit signals for synchronization in shared-memory programs. Requiring programmers to signal threads explicitly results in many concurrency bugs due to missed notifications, or notifications on wrong condition variables. In this paper, we describe an implementation of an automatic signaling monitor in Java called AutoSynch that eliminates such concurrency bugs by removing the burden of signaling from the programmer. We show that the belief that automatic signaling monitors are prohibitively expensive is wrong. For most problems, programs based on AutoSynch are almost as fast as those based on explicit signaling. For some, AutoSynch is even faster than explicit signaling because it never uses signalAll, whereas the programmers end up using signalAll with the explicit signal mechanism.

AutoSynch} achieves efficiency in synchronization based on three novel ideas. We introduce an operation called closure that enables the predicate evaluation in every thread, thereby reducing context switches during the execution of the program. Secondly, AutoSynch avoids signalAll by using a property called relay invariance that guarantees that whenever possible there is always at least one thread whose condition is true which has been signaled. Finally, AutoSynch uses a technique called predicate tagging to efficiently determine a thread that should be signaled. To evaluate the efficiency of AutoSynch, we have implemented many different well-known synchronization problems such as the producers/consumers problem, the readers/writers problems, and the dining philosophers problem. The results show that AutoSynch is almost as efficient as the explicit-signal monitor and even more efficient for some cases.
Thresher
Authors: Blackshear Sam , Chang Bor-Yuh Evan , Sridharan Manu
Published: July 2013

We present a precise, path-sensitive static analysis for reasoning about heap reachability, that is, whether an object can be reached from another variable or object via pointer dereferences. Precise reachability information is useful for a number of clients, including static detection of a class of Android memory leaks. For this client, we found the heap reachability information computed by a state-of-the-art points-to analysis was too imprecise, leading to numerous false-positive leak reports. Our analysis combines a symbolic execution capable of path-sensitivity and strong updates with abstract heap information computed by an initial flow-insensitive points-to analysis. This novel mixed representation allows us to achieve both precision and scalability by leveraging the pre-computed points-to facts to guide execution and prune infeasible paths. We have evaluated our techniques in the Thresher tool, which we used to find several developer-confirmed leaks in Android applications.
Modular verification of linearizability with non-fixed linearization points
Authors: Liang Hongjin , Feng Xinyu
Published: July 2013

Locating linearization points (LPs) is an intuitive approach for proving linearizability, but it is difficult to apply the idea in Hoare-style logic for formal program verification, especially for verifying algorithms whose LPs cannot be statically located in the code. In this paper, we propose a program logic with a lightweight instrumentation mechanism which can verify algorithms with non-fixed LPs, including the most challenging ones that use the helping mechanism to achieve lock-freedom (as in HSY elimination-based stack), or have LPs depending on unpredictable future executions (as in the lazy set algorithm), or involve both features. We also develop a thread-local simulation as the meta-theory of our logic, and show it implies contextual refinement, which is equivalent to linearizability. Using our logic we have successfully verified various classic algorithms, some of which are used in the java.util.concurrent package.
Bilateral Radial Ulnar Synostosis and Vertebral Anomalies in a Child with aDe Novo16p13.3 Interstitial Deletion
Authors: Tam Allison , Lee Kit Shan , Lee Sansan , Burkhalter William , Pascua Lucio U. , Slavin Thomas P.
Published: July 2013

We describe an 8-year-old boy with developmental delay, clinical bilateral radial ulnar synostosis, Klippel-Feil anomaly, and other vertebral deformities who was found to have ade novodeletion of 114.5kb at 16p13.3. The deletion contains five genes and three miRNAs. The genes areE4F1, DNASE1L2, ECI1, RNPS1, andABCA3; miRNAs are MIR3677, MIR940, and MIR4717. The specific deletion has never been previously reported. We describe the phenotype of the boy and review the genes in the deleted region. None of the regulatory elements have any known linkage to skeletal formation and/or maintenance. We believe this deletion is causative given that it wasde novoand that this patient cannot be easily explained as having any other specific recognizable pattern of human malformation.
Does Household Food Insecurity Affect the Nutritional Status of Preschool Children Aged 6–36 Months?
Authors: Saaka Mahama , Osman Shaibu Mohammed
Published: July 2013

Introduction. This study used three dependent measures of food security to assess the magnitude of household food insecurity and its consequences on the nutritional status of children 6–36 months in Tamale Metropolis of Northern Ghana. Methods. An analytical cross-sectional study was conducted on a sample of 337 mother/child pairs in June 2012. Food access was measured as household food insecurity access scale (HFIAS), household dietary diversity score (HDDS), and food consumption score (FCS). Results. The magnitude of household food insecurity depended on the food access indicator, with HFIAS yielding the highest household food insecurity of 54%. Of the three food access indicators, 30-day HFIAS was not related to any of the nutrition indices measured. HDDS and FCS were both significantly associated with BMI of mothers and chronic malnutrition (stunted growth) but not acute malnutrition (wasting) with FCS being a stronger predictor of nutritional status. Compared to children in food insecure households, children in food secure households were 46% protected from chronic malnutrition (, 95% CI: 0.31–0.94). Conclusions and Recommendations. The results of this study show that different measures of household food insecurity produce varied degree of the problem. Efforts at reducing chronic child malnutrition should focus on improving the adequacy of the diet.
Existence of Solutions for a Modified Nonlinear Schrödinger System
Authors: Jiao Yujuan , Wang Yanli
Published: July 2013

We are concerned with the following modified nonlinear Schrödinger system:-Δu+u-(1/2)uΔ(u2)=(2α/(α+β))|u|α-2|v|βu,  x∈Ω,  -Δv+v-(1/2)vΔ(v2)=(2β/(α+β))|u|α|v|β-2v,  x∈Ω,  u=0,  v=0,  x∈∂Ω, whereα>2,  β>2,  α+β<2·2*,  2*=2N/(N-2)is the critical Sobolev exponent, andΩ⊂ℝN  (N≥3)is a bounded smooth domain. By using the perturbation method, we establish the existence of both positive and negative solutions for this system.
A Review on Tribological Behaviour of Polymeric Composites and Future Reinforcements
Authors: Aldousiri B. , Shalwan A. , Chin C. W.
Published: July 2013

Many different families of polymers are used in industries and engineering applications. The demands for studying the tribological behaviour of polymers and their composites are recently increased. This article briefs the most recent studies on the tribological behaviour of polymeric materials based on synthetic fibres. It reviews several factors which control the wear and frictional characteristics of such materials, that is, additives, fibres, interfacial adhesion, tribology environment, operating parameters, and composite geometry. In addition to that, new bioreinforcement (fibre) is introduced associated with preliminary results. The results showed that there is high potential of replacing the conventional reinforcement with the bioones.
Innovative Strategy to Improve Precision and to Save Power of a Real-Time Control Process Using an Online Adaptive Fuzzy Logic Controller
Authors: Lasri R. , Rojas I. , Pomares H. , Valenzuela O.
Published: July 2013

The main objective of this paper is to prove the great advantage that brings our novel approach to the intelligent control area. A set of various types of intelligent controllers have been designed to control the temperature of a room in a real-time control process in order to compare the obtained results with each other. Through a training board that allows us to control the temperature, all the used algorithms should present their best performances in this control process; therefore, our self-organized and online adaptive fuzzy logic controller (FLC) will be required to present great improvements in the control task and a real high control performance. Simulation results can show clearly that the new approach presented and tested in this work is very efficient. Thus, our adaptive and self-organizing FLC presents the best accuracy compared with the remaining used controllers, and, besides that, it can guarantee an important reduction of the power consumption during the control process.
Sustainable Use of Tepetate Composite in Earthen Structure
Authors: López-Lara T. , Hernandez-Zaragoza Juan Bosco , Horta Jaime , Rojas Gonzalez Eduardo , Lopez-Cajun Carlos , Ramirez Gerson
Published: July 2013

One of the best indicators for construction sustainability is the use of earthy local materials which are completely recyclables and savers of energy during their life cycle. Tepetate is an underestimated earth-natural material, vast and economic, used only in a compacted form in backfills for layers of low resistance in pavements and platforms of buildings. This volcanic soil, named in different ways in several countries, is found in the central region of Mexico. Its resistance as compacted material is very low, of the order of 0.08 MPa. In this work, an improved sustainable-tepetate composite, using CaOH, is presented. This research includes the determination of mechanical properties as well as the physicochemical characterization of the sustainable-tepetate composite behavior. It can be concluded that the strength of the proposed composite increases significantly, immediately after treatment and with time. X-Ray Diffraction shows that all the mineralogical phases prevail in the natural tepetate and only a new phase appeared (calcite), which increases with time. This and the reaction of CaOH with clay content are very likely associated with the continuous strength increase of the composite.
A Class of -Dimensional Dirac Operators with a Variable Mass
Authors: Arai Asao , Dagva Dayantsolmon
Published: July 2013

A class of d-dimensional Dirac operators with a variable mass is introduced (), which includes, as a special case, the 3-dimensional Dirac operator describing the chiral quark soliton model in nuclear physics, and some aspects of it are investigated.
Bacterial Infections across the Ants: Frequency and Prevalence ofWolbachia, Spiroplasma, andAsaia
Authors: Kautz Stefanie , Rubin Benjamin E. R. , Moreau Corrie S.
Published: July 2013

Bacterial endosymbionts are common across insects, but we often lack a deeper knowledge of their prevalence across most organisms. Next-generation sequencing approaches can characterize bacterial diversity associated with a host and at the same time facilitate the fast and simultaneous screening of infectious bacteria. In this study, we used 16S rRNA tag encoded amplicon pyrosequencing to survey bacterial communities of 310 samples representing 221 individuals, 176 colonies and 95 species of ants. We found three distinct endosymbiont groups—Wolbachia(Alphaproteobacteria: Rickettsiales),Spiroplasma(Firmicutes: Entomoplasmatales), and relatives ofAsaia(Alphaproteobacteria: Rhodospirillales)—at different infection frequencies (at the ant species level: 22.1%, 28.4%, and 14.7%, resp.) and relative abundances within bacterial communities (1.0%–99.9%).Spiroplasmawas particularly enriched in the ant genusPolyrhachis, whileAsaiarelatives were most prevalent in arboreal ants of the genusPseudomyrmex. WhileWolbachiaandSpiroplasmahave been surveyed in ants before,Asaia, an acetic acid bacterium capable of fixing atmospheric nitrogen, has received much less attention. Due to sporadic prevalence across all ant taxa investigated, we hypothesize facultative associations for all three bacterial genera. Infection patterns are discussed in relation to potential adaptation of specific bacteria in certain ant groups.
Promising New Treatments for Psoriasis
Authors: Dubois Declercq Sarah , Pouliot Roxane
Published: July 2013

Psoriasis is a chronic, proliferative, and inflammatory skin disease affecting 2‐3% of the population and is characterized by red plaques with white scales. Psoriasis is a disease that can affect many aspects of professional and social life. Currently, several treatments are available to help control psoriasis such as methotrexate, ciclosporin, and oral retinoids. However, the available treatments are only able to relieve the symptoms and lives of individuals. The discovery of new immunological factors and a better understanding of psoriasis have turned to the use of immunological pathways and could develop new biological drugs against specific immunological elements that cause psoriasis. Biological drugs are less toxic to the body and more effective than traditional therapies. Thus, they should improve the quality of life of patients with psoriasis. This review describes new psoriasis treatments, which are on the market or currently in clinical trials that are being used to treat moderate‐to‐severe plaque psoriasis. In addition, this paper describes the characteristics and mechanisms in detail. In general, biological drugs are well tolerated and appear to be an effective alternative to conventional therapies. However, their effectiveness and long‐term side effects need to be further researched.
The Role of CT Pulmonary Angiography in the Investigation of Unilateral Pleural Effusions
Authors: Hooper Clare , Laurence Isabel , Harvey John , Morley Anna , Darby Mike , Edey Anthony , Maskell Nick
Published: July 2013

Background: Pulmonary embolism (PE) is frequently cited as a common primary cause of unilateral pleural effusion, but in clinical practice appears to be uncommon. Objectives: In order to evaluate this observation, CT pulmonary angiography (CTPA) was performed in consecutive patients presenting to a single centre with a new uninvestigated unilateral pleural effusion and no clear cause and was supplemented by delayed-phase thoracic CT, optimized for visualization of the pleura. Methods: All patients underwent standard clinical assessment and pleural investigations in line with recent national guidelines and were followed up for a minimum of 1 year or until histological/microbiological diagnosis. Results: One hundred and fifty patients were recruited, and of these, 141 had a CTPA. PEs were detected in 9/141 (6.4%) patients, and of these, 8/9 were subsequently diagnosed with pleural malignancy. In only 1 case was PE clinically suspected and in no case was PE the primary cause of effusion; 9.8% (8/82) of patients who were ultimately diagnosed with pleural malignancy had PE at presentation. Conclusions: This study indicates that PE is a frequent concomitant finding in patients with malignant effusions but uncommon as a primary cause of unilateral effusion. In addition, it highlights the known difficulty of clinical diagnosis of PE in the context of malignancy. In view of this, we recommend that CTPA combined with pleural-phase thoracic CT should be considered at presentation when investigating patients with suspected malignant pleural effusion.
Are Plasma Homocysteine Concentrations in Brazilian Adolescents Influenced by the Intake of the Main Food Sources of Natural Folate?
Authors: Bigio Roberta Schein , Verly Jr Eliseu , de Castro Michelle Alessandra , Cesar Chester Luis Galvão , Fisberg Regina Mara , Marchioni Dirce Maria Lobo
Published: July 2013

Background: Folate, a B vitamin, has been associated with a reduced concentration of plasma homocysteine (phcy), a marker of cardiovascular disease. The contribution of fruits and vegetables (FV) and other natural folate-rich foods to folate intake and folate status in Brazilian adolescents has hardly been determined. Objectives: To investigate the intake of FV and beans and its association with the concentration of phcy in adolescents. Methods: This was a cross-sectional population-based study with a complex sample survey, with 198 adolescents who completed two 24-hour dietary recalls, a food frequency questionnaire, and a fasting blood draw. Usual dietary intake estimates were derived applying the Multiple Source Method. Three different generalized linear models with a gamma distribution were developed for each sex to evaluate the relationship between phcy and tertiles of FV intake as well as to evaluate the relationship between phcy and tertiles of FV and bean intake. Results: No association was found between phcy concentration and FV intake or between phcy and FV and beans. Serum folate and female sex were inversely related to phcy. Conclusion: Phcy was not related to FV or FV and beans; this may be attributable to a low intake of these food groups.
Impact of Gestational Age on Neonatal Hearing Screening in Vaginally-Born Late-Preterm and Early-Term Infants
Authors: Smolkin Tatiana , Anton Yasmin , Ulanovsky Irena , Blazer Shraga , Mick Orna , Makhoul Majd I. , Makhoul Imad R.
Published: July 2013

Background: Late-preterm and early-term (LP-ET) infants, defined herein as 35⁰-376 weeks' gestation, often fail on 1st otoacoustic emissions (OAE) test. Hypothesis: LP-ET infants fail more than term infants (38⁰-42 weeks' gestation) on the 1st OAE test. Aim: To evaluate the effect of gestational age on the 1st OAE test. Methods: We studied 1,572 vaginally-delivered (VD) infants ≥35 weeks' gestation (1.1.2011-30.9.2011). Perinatal and neonatal variables and results of OAE tests were recorded. Results: LP-ET infants, compared to full-term infants, had a significantly 2-fold higher need for repeated hearing tests: 80.2 versus 43.3 tests/1,000 neonates, respectively (p = 0.026). Univariate analysis showed that late prematurity and age at 1st OAE were significantly associated with failure on 1st OAE. At age 24-42 h, failure on 1st OAE was 2-fold higher in the LP-ET infants than in full-term infants: 9.4 versus 4.7% (p = 0.02). Risk for failure on 1st OAE was age-dependent: 9-fold higher when 1st OAE was performed at 24-42 h of age (5.3%) versus 0.6% after age 42 h. Multivariate analysis showed that variables that were independently significantly associated with failure on 1st OAE included late prematurity (OR 2.0 (1.1-3.7)) and age at 1st OAE (OR 9.2 (1.2-70.7)). Conclusions: Compared to term infants, VD LP-ET infants had 2-fold higher rates of failure on 1st OAE (up to 42 h of life) and needed repeated hearing tests. Failure rates after 42 h become negligible in both groups. In VD LP-ET infants, 1st OAE is better performed after 42 h of age.
Improving Accuracy in Image-Guided Prostate Biopsy by Using Trocar-Sharpened Needles
Authors: Kuru Timur H. , Simpfendörfer Tobias , Roethke Matthias , Hohenfellner Markus , Hadaschik Boris A.
Published: July 2013

Objective: To optimize image-guided prostate biopsy by minimizing the target error with trocar-sharpened needle tips instead of beveled needles, which constantly deviate away from the bevel. Materials and Methods: We performed stereotactic biopsies on two prostate phantoms, which incorporate three randomly placed TRUS-visible lesions. Four stereotactic biopsies per lesion were taken under live-ultrasound guidance through a template: two biopsies with conventional beveled needles and two biopsies with novel trocar-sharpened needles. The procedural targeting error (PTE) between the virtually planned biopsy trajectory and the manually registered 3D needle position of every single biopsy core taken was calculated. Results: The absolute overall targeting error using the novel needle-tip design was 0.13 mm (SD: ± 0.15 mm) with the highest PTE in the sagittal plane (0.18 ± 0.16 mm), followed by the coronal (0.13 ± 0.17 mm) and axial (0.09 ± 0.05 mm) planes. Comparing the PTE of the novel trocar-shaped needles with conventional beveled needles, there was a statistically significant difference in the axial plane [p (overall) = 0.47, p(axial) = 0.03]. Conclusion: The targeting error of stereotactic biopsies using trocar-sharpened needles is significantly lower than the targeting error of classical beveled needles. Thus, trocar-tip configurations improve the accuracy of computer-assisted biopsies and allow precise assessment of suspicious lesions in the prostate and in other organs accessible to image-guided biopsy.
Endothelin-1 Release during the Early Phase of Reperfusion Is a Mediator of Myocardial Reperfusion Injury
Authors: Tamareille Sophie , Terwelp Matthew , Amirian James , Felli Patricia , Zhang Xiu Q. , Barry William H. , Smalling Richard W.
Published: July 2013

Purpose: In acute myocardial infarction, left ventricular (LV) unloading reduces endothelin-1 (ET-1) release. We tested that endogenous ET-1 released during acute myocardial infarction might mediate ischemia/reperfusion (I/R) injury by stimulating increased intracellular calcium concentration, [Ca2+]i, and apoptosis. Methods: Rabbits were subjected to 1 h of coronary artery occlusion followed by 3 h of reperfusion. Unloading was initiated 15 min prior to reperfusion and was maintained during reperfusion. The control group was subjected to reperfusion. Animals were treated with ET-1 receptor antagonist BQ123. In parallel, isolated rabbit cardiomyocytes subjected to simulated I/R with or without ET-1 or BQ123, intracellular Ca2+ and cell death were assessed with flow cytometry. Results: LV unloading prior to reperfusion reduced myocardial ET-1 release at 2 h of reperfusion. Infarct size was reduced in unloaded and BQ123 groups versus controls. LV unloading and BQ123 treatment reduced the percentage of apoptotic cells associated with increases in Bcl-2 protein levels in ischemic regions. BQ123 reduced both ET-1-induced [Ca2+]i increase and cell death for myocytes subjected to stimulated I/R. Conclusion: We propose that components of reperfusion injury involve ET-1 release which stimulates calcium overload and apoptosis. Intravenous ET-1 receptor blockade prior to reperfusion may be a protective adjunct to reperfusion therapy in acute myocardial infarction patients.
Lung Cancer Stigma, Anxiety, Depression and Symptom Severity
Authors: Cataldo Janine K. , Brodsky Jennifer L.
Published: July 2013

Objectives: Compared to other cancers, lung cancer patients report the highest levels of psychological distress and stigma. Few studies have examined the relationship between lung cancer stigma (LCS) and symptom burden. This study was designed to investigate the relationship between LCS, anxiety, depression and physical symptom severity. Methods: This study employed a cross-sectional, correlational design to recruit patients online from lung cancer websites. LCS, anxiety, depression and physical symptoms were measured by patient self-report using validated scales via the Internet. Hierarchical multiple regression was performed to investigate the individual contributions of LCS, anxiety and depression to symptom severity. Results: Patients had a mean age of 57 years; 93% were Caucasian, 79% were current or former smokers, and 74% were female. There were strong positive relationships between LCS and anxiety (r = 0.413, p < 0.001), depression (r = 0.559, p < 0.001) and total lung cancer symptom severity (r = 0.483, p < 0.001). Although its contribution was small, LCS provided a unique and significant explanation of the variance in symptom severity beyond that of age, anxiety and depression, by 1.3% (p < 0.05). Conclusions: Because LCS is associated with psychosocial and physical health outcomes, research is needed to develop interventions to assist patients to manage LCS and to enhance their ability to communicate effectively with clinicians.
Cutaneous Adverse Drug Reaction to Oral Acetazolamide and Skin Tests
Authors: Jachiet M. , Bellon N. , Assier H. , Amsler E. , Gaouar H. , Pecquet C. , Bourrain J.L. , Bégon E. , Chosidow O. , Francès C. , Ingen-Housz-Oro S. , Soria A.
Published: July 2013

Background: Few cases of cutaneous adverse drug reactions (CADR) to oral acetazolamide, a non-antimicrobial sulfonamide, have been previously reported, and the interest of acetazolamide skin tests has never been studied. Objectives: We report a series of ten patients with oral acetazolamide CADR and skin tests. Patients and Methods: The files of ten patients with CADR secondary to oral acetazolamide prescribed for cataract surgery in most cases referred between 2001 and 2011 in four French dermatology and allergy departments were retrospectively reviewed. Skin tests with acetazolamide were performed in nine patients and twelve controls. Other sulfonamides were tested in five of ten patients. Results: Seven patients developed maculopapular exanthema and four had acute generalized exanthematous pustulosis. Patch tests were positive for 8/9 patients, prick tests for 2/4 and intradermal tests for 3/3. Patch and prick or intradermal test results were concordant in 2/3 positive subjects. Patch tests for other sulfonamides were negative, as were patch tests in controls. Conclusions: We report the largest series of CADR to oral acetazolamide (maculopapular exanthema or acute generalized exanthematous pustulosis). A drug eruption after cataract surgery should be investigated for accountability of acetazolamide. In view of this retrospective study, skin tests and particularly intradermal tests appear to be an important contribution to demonstrate accountability.
Acinetobacter baumannii Infections in a Tertiary Care Hospital in Mexico over the Past 13 Years
Authors: Morfín-Otero R. , Alcántar-Curiel M.D. , Rocha M.J. , Alpuche-Aranda C.M. , Santos-Preciado J.I. , Gayosso-Vázquez C. , Araiza-Navarro J.R. , Flores-Vaca M. , Esparza-Ahumada S. , González-Díaz E. , Pérez-Gómez H.R. , Rodríguez-Noriega E.
Published: July 2013

Background:Acinetobacter baumannii has evolved from an opportunistic pathogen into a common and persistent nosocomial bacterium capable of causing severe infections during endemic and epidemic periods. Methods: The study period extended from January 1999 to December 2011 and involved patients hospitalized at the Hospital Civil de Guadalajara, Fray Antonio Alcalde, Jalisco, Mexico. From each patient, a single isolate was obtained, and a total of 3,680 unique isolates were collected. Susceptibility tests were performed according to the guidelines of the Clinical and Laboratory Standards Institute. Results:A. baumannii has disseminated throughout the Hospital Civil de Guadalajara, Fray Antonio Alcalde, since 1999. A. baumannii isolates obtained from patients treated in the adult intensive care unit represent the majority of the isolates that have been collected. In addition, A. baumannii was isolated from the adult neurosurgical ward and the adult internal medicine ward, and these isolates were frequently obtained from secretions. A persistent decrease in the susceptibility of A. baumannii isolates to meropenem (92% in 1999 to 12% in 2011), imipenem and amikacin has been observed. Conclusions:A. baumannii became an endemic nosocomial pathogen during the study period at the Hospital Civil de Guadalajara, Fray Antonio Alcalde, and has exhibited a persistent decrease in susceptibility to all categories of antimicrobial agents over the past 13 years.
Angiographic and Clinical Characteristics according to Intracoronary Acetylcholine Dose in Patients with Myocardial Bridge
Authors: Im Sung Il , Rha Seung-Woon , Choi Byoung Geol , Choi Se Yeon , Kim Sun Won , Na Jin Oh , Choi Cheol Ung , Lim Hong Euy , Kim Jin Won , Kim Eung Ju , Park Chang Gyu , Seo Hong Seog , Oh Dong Joo
Published: July 2013

Objectives: It is well known that myocardial bridge (MB) is a risk factor of vasospastic angina. However, clinical and angiographic characteristics according to different acetylcholine (ACh) dose in patients with MB are not clarified yet. Methods: A total 483 consecutive patients who had angiographically proven MB underwent the intracoronary ACh provocation test. ACh was injected by incremental doses of 20, 50 and 100 μg into the left coronary artery. We evaluated the clinical and angiographic characteristics of patients with MB according to 3 different ACh doses. Results: The baseline clinical and procedural characteristics are well balanced among the three groups. The MB patients who responded to the lower ACh dose (20 μg) had higher incidence of baseline spasm, severe vasospasm and diffuse long spasms (>30 mm) than those who responded to the higher doses (50 and 100 μg). The incidence of 12-month mortality and recurrent chest pain was higher in the lower ACh dose group (20 μg). Conclusion: The patients with MB significantly reacting at the low ACh dose had more pronounced baseline spasm, severe and diffuse long coronary artery spasm, higher 12-month mortality and recurrent chest pain than those reacting with the higher ACh doses, suggesting that more intensive medical therapy will be required.
Dermoscopy of Melanocytic Lesions in Patients Affected by Oculocutaneous Albinism: A Case Series
Authors: Caldarola Giacomo , Fania Luca , Fossati Barbara , Zampetti Anna , Broganelli Paolo , Massi Guido , Feliciani Claudio
Published: July 2013

Background: Although the majority of skin cancers in albino patients consists of squamous and basal cell carcinomas, malignant melanomas have also been described, albeit less frequently. Objective: The aim of our study was to evaluate melanocytic lesions in albino patients to look for any recurrent dermoscopic pattern. Methods: We enrolled 12 consecutive albino patients presenting to our department and examined each patient for the presence of melanocytic nevi with the unaided eye and then with dermoscopy. Melanocytic lesions with suspicious clinical or dermoscopic features were excised and histopathologically evaluated. Results: Analysis of the recorded images permitted us to find two main dermoscopic patterns in this group of patients. The first one was represented by a homogeneous light-brown yellowish pattern associated with comma-like and dotted vessels; the second one consisted of a classical brown reticular pattern frequently associated with central depigmentation and with comma-like vessels. Moreover, based on some atypical dermoscopic features, in 2 patients we excised 3 melanomas in situ (in the same patient) and a thick melanoma (3.2 mm). Conclusions: Dermoscopy may represent a useful tool for the evaluation of melanocytic lesions in albino patients, permitting an early diagnosis of melanoma.