bluuebunny/crossref_metadata_2025 huggingface dataset:
TimeWarp
Authors: Martin Robert , Demme John , Sethumadhavan Simha
Published: September 2012

Over the past two decades, several microarchitectural side channels have been exploited to create sophisticated security attacks. Solutions to this problem have mainly focused on fixing the source of leaks either by limiting the flow of information through the side channel by modifying hardware, or by refactoring vulnerable software to protect sensitive data from leaking. These solutions are reactive and not preventative: while the modifications may protect against a single attack, they do nothing to prevent future side channel attacks that exploit other microarchitectural side channels or exploit the same side channel in a novel way.

In this paper we present a general mitigation strategy that focuses on the infrastructure used to measure side channel leaks rather than the source of leaks, and thus applies to all known and unknown microarchitectural side channel leaks. Our approach is to limit the fidelity of fine grain timekeeping and performance counters, making it difficult for an attacker to distinguish between different microarchitectural events, thus thwarting attacks. We demonstrate the strength of our proposed security modifications, and validate that our changes do not break existing software. Our proposed changes require minor -- or in some cases, no -- hardware modifications and do not result in any substantial performance degradation, yet offer the most comprehensive protection against microarchitectural side channels to date.
A micro-architectural analysis of switched photonic multi-chip interconnects
Authors: Koka Pranay , McCracken Michael O. , Schwetman Herb , Chen Chia-Hsin Owen , Zheng Xuezhe , Ho Ron , Raj Kannan , Krishnamoorthy Ashok V.
Published: September 2012

Silicon photonics is a promising technology to scale offchip bandwidth in a power-efficient manner. Given equivalent bandwidth, the flexibility of switched networks often leads to the assumption that they deliver greater performance than point-to-point networks on message passing applications with low-radix traffic patterns. However, when optical losses are considered and total optical power is constrained, this assumption no longer holds.

In this paper we present a power constrained method for designing photonic interconnects that uses the power characteristics and limits of optical switches, waveguide crossings, inter-layer couplers and waveguides. We apply this method to design three switched network topologies for a multi-chip system.

Using synthetic and HPC benchmark-derived message patterns, we simulated the three switched networks and a WDM point-to-point network. We show that switched networks outperform point-to-point networks only when the optical losses of switches and inter-layer couplers losses are each 0.75 dB or lower; achieving this would require a major breakthrough in device development. We then show that this result extends to any switched network with similarly complex topology, through simulations of an idealized "perfect" network that supports 90% of the peak bandwidth under all traffic patterns. We conclude that given a fixed amount of input optical power, under realistic device assumptions, a point-to-point network has the best performance and energy characteristics.
RADISH
Authors: Devietti Joseph , Wood Benjamin P. , Strauss Karin , Ceze Luis , Grossman Dan , Qadeer Shaz
Published: September 2012

Data-race freedom is a valuable safety property for multithreaded programs that helps with catching bugs, simplifying memory consistency model semantics, and verifying and enforcing both atomicity and determinism. Unfortunately, existing software-only dynamic race detectors are precise but slow; proposals with hardware support offer higher performance but are imprecise. Both precision and performance are necessary to achieve the many advantages always-on dynamic race detection could provide.

To resolve this trade-off, we propose Radish, a hybrid hardware-software dynamic race detector that is always-on and fully precise. In Radish, hardware caches a principled subset of the metadata necessary for race detection; this subset allows the vast majority of race checks to occur completely in hardware. A flexible software layer handles persistence of race detection metadata on cache evictions and occasional queries to this expanded set of metadata. We show that Radish is correct by proving equivalence to a conventional happens-before race detector.

Our design has modest hardware complexity: caches are completely unmodified and we piggy-back on existing coherence messages but do not otherwise modify the protocol. Furthermore, Radish can leverage type-safe languages to reduce overheads substantially. Our evaluation of a simulated 8-core Radish processor using PARSEC benchmarks shows runtime overheads from negligible to 2x, outperforming the leading software-only race detector by 2x-37x.
Configurable fine-grain protection for multicore processor virtualization
Authors: Wentzlaff David , Jackson Christopher J. , Griffin Patrick , Agarwal Anant
Published: September 2012

Multicore architectures, with their abundant on-chip resources, are effectively collections of systems-on-a-chip. The protection system for these architectures must support multiple concurrently executing operating systems (OSes) with different needs, and manage and protect the hardware's novel communication mechanisms and hardware features. Traditional protection systems are insufficient; they protect supervisor from user code, but typically do not protect one system from another, and only support fixed assignment of resources to protection levels. In this paper, we propose an alternative to traditional protection systems which we call configurable fine-grain protection (CFP). CFP enables the dynamic assignment of in-core resources to protection levels. We investigate how CFP enables different system software stacks to utilize the same configurable protection hardware, and how differing OSes can execute at the same time on a multicore processor with CFP. As illustration, we describe an implementation of CFP in a commercial multicore, the TILE64 processor.
Scale-out processors
Authors: Lotfi-Kamran Pejman , Grot Boris , Ferdman Michael , Volos Stavros , Kocberber Onur , Picorel Javier , Adileh Almutaz , Jevdjic Djordje , Idgunji Sachin , Ozer Emre , Falsafi Babak
Published: September 2012

Scale-out datacenters mandate high per-server throughput to get the maximum benefit from the large TCO investment. Emerging applications (e.g., data serving and web search) that run in these datacenters operate on vast datasets that are not accommodated by on-die caches of existing server chips. Large caches reduce the die area available for cores and lower performance through long access latency when instructions are fetched. Performance on scale-out workloads is maximized through a modestly-sized last-level cache that captures the instruction footprint at the lowest possible access latency.

In this work, we introduce a methodology for designing scalable and efficient scale-out server processors. Based on a metric of performance-density, we facilitate the design of optimal multi-core configurations, called pods. Each pod is a complete server that tightly couples a number of cores to a small last-level cache using a fast interconnect. Replicating the pod to fill the die area yields processors which have optimal performance density, leading to maximum per-chip throughput. Moreover, as each pod is a stand-alone server, scale-out processors avoid the expense of global (i.e., inter-pod) interconnect and coherence. These features synergistically maximize throughput, lower design complexity, and improve technology scalability. In 20nm technology, scale-out chips improve throughput by 5x-6.5x over conventional and by 1.6x-1.9x over emerging tiled organizations.
BlockChop
Authors: Mars Jason , Kumar Naveen
Published: September 2012

Hybrid processors are HW/SW co-designed processors that leverage blocked-execution, the execution of regions of instructions as atomic blocks, to facilitate aggressive speculative optimization. As we move to a multicore hybrid design, fine grained conflicts for shared data can violate the atomicity requirement of these blocks and lead to expensive squashes and rollbacks. However, as these atomic regions differ from those used in checkpointing and transactional memory systems, the extent of this potentially prohibitive problem remains unclear, and mechanisms to mitigate these squashes dynamically may be critical to enable a highly per-formant multicore hybrid design.

In this work, we investigate how multithreaded applications, both benchmark and commercial workloads, are affected by squashes, and present dynamic mechanisms for mitigating these squashes in hybrid processors. While the current wisdom is that there is not a significant number of squashes for smaller atomic regions, we observe this is not the case for many multithreaded workloads. With region sizes of just 200--500 instructions, we observe a performance degradation ranging from 10% to more than 50% for workloads with a mixture of shared reads and writes. By harnessing the unique flexibility provided by the software subsystem of hybrid processor design, we present
BlockChop
, a framework for dynamically mitigating squashes on multicore hybrid processors. We present a range of squash handling mechanisms leveraging retrials, interpretation, and retranslation, and find that BlockChop is quite effective. Over the current response to exceptions and squashes in a hybrid design, we are able to improve the performance of benchmark and commercial workloads by 1.4x and 1.2x on average for large and small region sizes respectively.
Disks from the Perspective of a File System
Authors: McKusick Marshall Kirk
Published: September 2012

Most applications do not deal with disks directly, instead storing their data in files in a file system, which protects us from those scoundrel disks. After all, a key task of the file system is to ensure that the file system can always be recovered to a consistent state after an unplanned system crash (for example, a power failure). While a good file system will be able to beat the disks into submission, the required effort can be great and the reduced performance annoying. This article examines the shortcuts that disks take and the hoops that file systems must jump through to get the desired reliability.
I/O-efficient spatial data structures for range queries
Authors: Arge Lars , Larsen Kasper Green
Published: September 2012

Range reporting is a one of the most fundamental topics in spatial databases and computational geometry. In this class of problems, the input consists of a set of geometric objects, such as points, line segments, rectangles etc. The goal is to preprocess the input set into a data structure, such that given a query range, one can efficiently report all input objects intersecting the range. The ranges most commonly considered are axis-parallel rectangles, halfspaces, points, simplices and balls.
Using TPIE for processing massive data sets in C++
Authors: Mølhave Thomas
Published: September 2012

The adaptation of I/O-efficient algorithms in commercial and research applications can be facilitated by well-designed software libraries. The Templated Portable I/O Environment (TPIE) [2] for C++ is one such library based on the I/O-model of Agarwal and Vitter [3]. TPIE contains a number of powerful algorithms and data structures, enabling the user to quickly develop software that scales to very large data sets. Figure 1 illustrates the power of I/O-efficient algorithms in general and TPIE in particular, in this case using an external memory sorting algorithm and priority queue. As the data size grows close to the 6GiB of main memory of the computer, the sorting algorithm from the C++ Standard Template Library (STL), std::sort, slows down dramatically. Beyond that point using std::sort is infeasible as running times extend into days and weeks even for date sizes only slightly larger than the main memory. STL's std::priority queue behaves in the same way. The sorting algorithm and the priority queue from TPIE are well behaved, even as the size of the input data grows to terabytes. The STXXL [8] and LEDA-SM [5] libraries have goals and features similar to those of TPIE. STXXL aims to be very close to C++'s Standard Template Library (STL) but also offers pipe-lining and some usage of multiple cores. LEDA-SM is an extension to the Library of Efficient Data Types and Algorithms (LEDA) and consists of a number of I/O-efficient data structures and algorithms. Unfortunately, the LEDA-SM project is not active according to a statement on the project's website. On a slightly different level the cluster-friendly FG [4] library provides a framework for pipe-line structured programs that also scale to large data sets. A significantly reworked version 2.0 has been announced on the project website. Moving further into the distributed computing paradigm, the MapReduce [7] and Hadoop [1] frameworks are very popular for implementing algorithms on clusters with large numbers of computing nodes, but that is outside the scope of this article. We refer to [10] and the references therein for a more extensive survey of I/O-efficient algorithms and software libraries.
Improving device-level electricity consumption breakdowns in private households using ON/OFF events
Authors: Beckel Christian , Kleiminger Wilhelm , Staake Thorsten , Santini Silvia
Published: September 2012

Smart meters can measure the electricity consumption of a household at a fine temporal granularity. By adequately processing this aggregated data an estimation of the consumption of individual appliances can be retrieved and used to provide novel services, such as personalized recommendations on how to reduce the overall energy consumption of the household. In this paper, we build upon existing work in consumption data disaggregation and consider smart meter data along with additional information made available by networked sensors and household appliances. In particular, we investigate the use of ON/OFF events, which signal when appliances have been turned on or off, to improve the accuracy of a state-of-the art disaggregation algorithm that uses such events along with smart meter data to estimate the consumption of single appliances. Our results, obtained by applying the algorithm to a publicly available dataset, show that the accuracy of the algorithm quickly deteriorates as the number of available ON/OFF events decreases. We thus suggest possible countermeasures to cope with this limitation and to provide accurate electricity consumption breakdowns in private households.
Modeling building thermal response to HVAC zoning
Authors: Smith Virginia , Sookoor Tamim , Whitehouse Kamin
Published: September 2012

HVAC systems account for 38% of building energy usage. Studies have indicated at least 5-15% waste due to unoccupied spaces being conditioned. Our goal is to minimize this waste by retrofitting HVAC systems to enable
room-level zoning
where each room is conditioned individually based on its occupancy. This will allow only occupied rooms to be conditioned while saving the energy used to condition unoccupied rooms. In order to achieve this goal, the effect of opening or closing air vent registers on room temperatures has to be predicted. Making such a prediction is complicated by the fact that weather has a larger effect on room temperatures than the settings of air vent registers, making it hard to isolate the influence of the HVAC system. We present a technique for dynamically estimating the heat load due to weather on room temperatures and subtracting it out in order to predict the effect of the HVAC system more directly.
On the applicability of network coding in wireless sensor networks
Authors: Voigt Thiemo , Roedig Utz , Landsiedel Olaf , Samarasinghe Kasun , Prasad Mahesh Bogadi Shankar
Published: September 2012

Network coding is a novel concept for improving network capacity. This additional capacity may be used to increase throughput or reliability. Also in wireless networks, network coding has been proposed as a method for improving communication. We present our experience from two studies of applying network coding in realistic wireless sensor networks scenarios. As we show, network coding is not as useful in practical deployments as earlier theoretical work suggested. We discuss limitations and future opportunities for network coding in sensor networks.
A differing role of oxidative stress in the regulation of central and peripheral hemodynamics during exercise in heart failure
Authors: Witman Melissa A. H. , McDaniel John , Fjeldstad Anette S. , Ives Stephen J. , Zhao Jia , Nativi Jose N. , Stehlik Josef , Walter Wray D. , Richardson Russell S.
Published: September 2012

This study sought to characterize the role of free radicals in regulating central and peripheral hemodynamics at rest and during exercise in patients with heart failure (HF). We examined cardiovascular responses to dynamic handgrip exercise (4, 8, and 12 kg at 1 Hz) following consumption of either a placebo or acute oral antioxidant cocktail (AOC) consisting of vitamin C, E, and α-lipoic acid in a balanced, crossover design. Central and peripheral hemodynamics, mean arterial pressure, cardiac index, systemic vascular resistance (SVR), brachial artery blood flow, and peripheral (arm) vascular resistance (PVR) were determined in 10 HF patients and 10 age-matched controls. Blood assays evaluated markers of oxidative stress and efficacy of the AOC. When compared with controls, patients with HF exhibited greater oxidative stress, measured by malondialdehyde (+36%), and evidence of endogenous antioxidant compensation, measured by greater superoxide dismutase activity (+83%). The AOC increased plasma ascorbate (+50%) in both the HF patients and controls, but significant systemic hemodynamic effects were only evident in the patients with HF, both at rest and throughout exercise. Specifically, the AOC reduced mean arterial pressure (−5%) and SVR (−12%) and increased cardiac index (+7%) at each workload. In contrast, peripherally, brachial artery blood flow and PVR (arm) were unchanged by the AOC. In conclusion, these data imply that SVR in patients with HF is, at least in part, mediated by oxidative stress. However, this finding does not appear to be the direct result of muscle-specific changes in PVR.
LPS-induced chorioamnionitis and antenatal corticosteroids modulate Shh signaling in the ovine fetal lung
Authors: Collins Jennifer J. P. , Kuypers Elke , Nitsos Ilias , Jane Pillow J. , Polglase Graeme R. , Kemp Matthew W. , Newnham John P. , Cleutjens Jack P. , Frints Suzanna G. M. , Kallapur Suhas G. , Jobe Alan H. , Kramer Boris W.
Published: September 2012

Chorioamnionitis and antenatal corticosteroids mature the fetal lung functionally but disrupt late-gestation lung development. Because Sonic Hedgehog (Shh) signaling is a major pathway directing lung development, we hypothesized that chorioamnionitis and antenatal corticosteroids modulated Shh signaling, resulting in an altered fetal lung structure. Time-mated ewes with singleton ovine fetuses received an intra-amniotic injection of lipopolysaccharide (LPS) and/or maternal intramuscular betamethasone 7 and/or 14 days before delivery at 120 days gestational age (GA) (term = 150 days GA). Intra-amniotic LPS exposure decreased Shh mRNA levels and Gli1 protein expression, which was counteracted by both betamethasone pre- or posttreatment. mRNA and protein levels of fibroblast growth factor 10 and bone morphogenetic protein 4, which are important mediators of lung development, increased 2-fold and 3.5-fold, respectively, 14 days after LPS exposure. Both 7-day and 14-day exposure to LPS changed the mRNA levels of elastin ( ELN) and collagen type I alpha 1 (Col1A1) and 2 (Col1A2), which resulted in fewer elastin foci and increased collagen type I deposition in the alveolar septa. Corticosteroid posttreatment prevented the decrease in ELN mRNA and increased elastin foci and decreased collagen type I deposition in the fetal lung. In conclusion, fetal lung exposure to LPS was accompanied by changes in key modulators of lung development resulting in abnormal lung structure. Betamethasone treatment partially prevented the changes in developmental processes and lung structure. This study provides new insights into clinically relevant prenatal exposures and fetal lung development.
Defining the characteristic relationship between arterial pressure and cerebral flow
Authors: Tan Can Ozan
Published: September 2012

Reliable assessment of cerebrovascular effectiveness in buffering against pressure fluctuations may have important implications for the timing and the outcome of therapy after adverse cerebrovascular events. Although linear approaches may indicate the presence or absence of cerebral autoregulation, they are inadequate to describe its characteristics and its effectiveness. Establishing a simple yet robust methodology to reliably measure the effectiveness of cerebral autoregulation could provide a tool to guide screening and clinical options to characterize and treat adverse cerebrovascular events associated with alterations in cerebral perfusion. To test the utility of one such methodology, an oscillatory lower body negative pressure of 30–40 mmHg was used at six frequencies from 0.03 to 0.08 Hz in 43 healthy volunteers, and the pressure-flow relation and the effectiveness of autoregulation was quantified using projection pursuit regression. Projection pursuit regression explained the majority of the relationship between pressure and cerebral blood flow fluctuations and revealed its nature consistently across individuals and across separate study days. The nature of this relationship entailed an autoregulatory region wherein slow arterial pressure fluctuations are effectively counterregulated and two passive regions wherein pressure fluctuations resulted in parallel changes in flow. The effectiveness of autoregulation was significantly reduced as pressure fluctuations became faster. These results demonstrate the characteristic relationship between arterial pressure and cerebral blood flow. Furthermore, the methodology utilized in this study provides a tool that can provide unique insight to integrated cerebrovascular control and may allow diagnosis of physiological alterations underlying impaired cerebral autoregulation.
Local administration of growth hormone stimulates tendon collagen synthesis in elderly men
Authors: Vestergaard Poul , Jørgensen Jens Otto Lunde , Olesen Jens L. , Bosnjak Ermina , Holm Lars , Frystyk Jan , Langberg Henning , Kjaer Michael , Hansen Mette
Published: September 2012

Tendon collagen content and circulating growth hormone (GH) are reduced in elderly. In a placebo-controlled, double-blinded study, we examined if local injections of rhGH enhance collagen synthesis in healthy elderly men (61 ± 1 yr). Two injections of rhGH or saline (control) were injected into each of the patient's patellar tendons, respectively. Subsequently, tendon collagen fractional synthesis rate (FSR) and an indirect marker of type I collagen synthesis (PINP) were measured. Within the first 6 h after the last injections, a tendency towards a higher tendon collagen FSR was observed in 10 out of 12 subjects ( P = 0.08). Similarly, PINP was higher 3–4 h after the last GH injection ( P = 0.05). Serum IGF-I did not change from baseline, whereas peritendinous bioactive IGF-I was higher in the GH leg vs. control ( P = 0.05). In conclusion, local injections of rhGH increase tendon collagen synthesis in humans, either directly or indirectly by increasing local bioactive IGF-I.
Adjustments of pulmonary O2 uptake and muscle deoxygenation during ramp incremental exercise and constant-load moderate-intensity exercise in young and older adults
Authors: Gravelle Braden M. R. , Murias Juan M. , Spencer Matthew D. , Paterson Donald H. , Kowalchuk John M.
Published: September 2012

The matching of muscle O2 delivery to O2 utilization can be inferred from the adjustments in muscle deoxygenation (Δ[HHb]) and pulmonary O2 uptake (V̇o2p). This study examined the adjustments of V̇o2p and Δ[HHb] during ramp incremental (RI) and constant-load (CL) exercise in adult males. Ten young adults (YA; age: 25 ± 5 yr) and nine older adults (OA; age: 70 ± 3 yr) completed two RI tests and six CL step transitions to a work rate (WR) corresponding to 1) 80% of the estimated lactate threshold (same relative WR) and 2) 50 W (same absolute WR). V̇o2p was measured breath by breath, and Δ[HHb] of the vastus lateralis was measured using near-infrared spectroscopy. Δ[HHb]-WR profiles were normalized from baseline (0%) to peak Δ[HHb] (100%) and fit using a sigmoid function. The sigmoid slope ( d) was greater ( P < 0.05) in OA (0.027 ± 0.01%/W) compared with YA (0.017 ± 0.01%/W), and the c/ d value (a value corresponding to 50% of the amplitude) was smaller ( P < 0.05) for OA (133 ± 40 W) than for YA (195 ± 51 W). No age-related differences in the sigmoid parameters were reported when WR was expressed as a percentage of peak WR. V̇o2p kinetics compared with Δ[HHb] kinetics for the 50-W transition were similar between YA and OA; however, Δ[HHb] kinetics during the transition to 80% of the lactate threshold were faster than V̇o2p kinetics in both groups. The greater reliance on O2 extraction displayed in OA during RI exercise suggests a lower O2 delivery-to-O2 utilization relationship at a given absolute WR compared with YA.
Preparation of a Modified PTFE Fibrous Photo-Fenton Catalyst and Its Optimization towards the Degradation of Organic Dye
Authors: Ding Zhizhong , Dong Yongchun , Li Bing
Published: September 2012

Polytetrafluoroethylene (PTFE) fiber was grafted with acrylic acid to impart the carboxyl groups onto the fiber surface, which were used to coordinate with both transition metal ions Fe(III) and Cu(II) and a rare metal ion Ce(III) to prepare the metal grafted PTFE fiber complexes as the novel heterogeneous Fenton catalysts for the degradation of the azo dye in water under visible irradiation. Some factors affecting the preparation process, such as nature and concentration of metal ions in the coordination solution, grafting degree of PTFE and reaction temperature were optimized with respect to the content and strength of metal fixation on the fiber and dye degradation efficiency. The results indicated that increasing metal ion concentrations in solution and grafting degree of PTFE fiber as well as higher coordination temperature led to a significant increase in metal content, especially Fe(III) and Cu(II) content of the complexes. Fe(III) ions fixed on the fiber showed the better catalytic performance than Cu(II) and Ce(III) ions fixed when three different complexes with similar metal content being employed, respectively. Moreover, Increasing Fe content or incorporation of Cu(II) ions could significantly improve the catalytic activity of the complexes.
Prediction of Breeding Values for Dairy Cattle Using Artificial Neural Networks and Neuro-Fuzzy Systems
Authors: Shahinfar Saleh , Mehrabani-Yeganeh Hassan , Lucas Caro , Kalhor Ahmad , Kazemian Majid , Weigel Kent A.
Published: September 2012

Developing machine learning and soft computing techniques has provided many opportunities for researchers to establish new analytical methods in different areas of science. The objective of this study is to investigate the potential of two types of intelligent learning methods, artificial neural networks and neuro-fuzzy systems, in order to estimate breeding values (EBV) of Iranian dairy cattle. Initially, the breeding values of lactating Holstein cows for milk and fat yield were estimated using conventional best linear unbiased prediction (BLUP) with an animal model. Once that was established, a multilayer perceptron was used to build ANN to predict breeding values from the performance data of selection candidates. Subsequently, fuzzy logic was used to form an NFS, a hybrid intelligent system that was implemented via a local linear model tree algorithm. For milk yield the correlations between EBV and EBV predicted by the ANN and NFS were 0.92 and 0.93, respectively. Corresponding correlations for fat yield were 0.93 and 0.93, respectively. Correlations between multitrait predictions of EBVs for milk and fat yield when predicted simultaneously by ANN were 0.93 and 0.93, respectively, whereas corresponding correlations with reference EBV for multitrait NFS were 0.94 and 0.95, respectively, for milk and fat production.
Growth Mechanism of a Hybrid Structure Consisting of a Graphite Layer on Top of Vertical Carbon Nanotubes
Authors: Chiodarelli Nicolo′ , Xu Cigang , Richard Olivier , Bender Hugo , Klekachev Alexander , Cooke Mike , Heyns Marc , De Gendt Stefan , Groeseneken Guido , Vereecken Philippe M.
Published: September 2012

Graphene and carbon nanotubes (CNTs) are both carbon‐based materials with remarkable optical and electronic properties which, among others, may find applications as transparent electrodes or as interconnects in microchips, respectively. This work reports on the formation of a hybrid structure composed of a graphitic carbon layer on top of vertical CNT in a single deposition process. The mechanism of deposition is explained according to the thickness of catalyst used and the atypical growth conditions. Key factors dictating the hybrid growth are the film thickness and the time dynamic through which the catalyst film dewets and transforms into nanoparticles. The results support the similarities between chemical vapor deposition processes for graphene, graphite, and CNT.
Transcriptional Read-Through Induction Treatment Trial in Intestinal Failure Induced by anEpCAMNonsense Mutation
Authors: Sivagnanam Mamata , Mueller James L. , Szigeti Reka , Gopalakrishna G. S. , Kellermayer Richard
Published: September 2012

Congenital tufting enteropathy (CTE) is a rare autosomal recessive diarrheal disorder where epithelial tufts can be present from the duodenum to the large intestine. CTE has been linked to mutations in the epithelial cell adhesion molecule gene (EpCAM) Sivagnanam et al. (2008). We recently reported the first case with a nonsense mutation inEpCAMSivagnanam et al. (2010). Here, we explored the clinical and molecular effects of enterally administered gentamicin in this CTE patient. Altogether, our findings indicate that the therapy employed was insufficient to produce notable read-through induction of theEpCAMpremature termination codon. This report highlights the utility of genetic testing not only in respect of diagnostics, prognostics, and family planning, but potential mutation-specific therapeutic considerations as well.
Clinical Significance of ErbB Receptor Family in Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-Analysis
Authors: Tsai Yuh-Shyan , Cheng Hong-Lin , Tzai Tzong-Shin , Chow Nan-Haw
Published: September 2012

The prognostic importance of examining ErbB receptor family expression in human bladder cancer remains uncertain. Using published evidence, we examined the clinical value and the updated results of clinical trials targeting ErbB receptor family members. Twenty-seven articles from 65 references related to ErbB receptor expression assessment in bladder cancer were reviewed. The estimates included the association significance, hazard ratios, and 95% confidence intervals (CIs) from actuarial curves and survival analyses. A meta-analysis was done on those reports using univariate log-rank tests or a Cox-regression model. The methods of analysis and study subjects chosen varied widely among studies. The overall risks of disease progression for patients with EGFR or ErbB2 overexpression were 4.5 (95% CI: 2.5–8.4) and 1.1 (95% CI: 0.6–1.9), and the risks of mortality were 3.0 (95% CI: 1.6–5.9) and 1.1 (95% CI: 1.0–1.2), respectively. However, the significance of coexpression patterns of the ErbB receptor family remains controversial. None of six clinical trials yielded convincing results for blockading ErbB receptor signaling in urothelial carcinoma. The results of this analysis suggest that assessing co-expression patterns of the ErbB family may provide better prognostic information for bladder cancer patients.
Sedentary Behavior and Physical Activity Are Independent Predictors of Successful Aging in Middle-Aged and Older Adults
Authors: Dogra Shilpa , Stathokostas Liza
Published: September 2012

Background. Sedentary behavior is emerging as an important risk factor for poor health. Physical activity has proven to be important in determining overall successful aging (SA) among older adults; however, no data exists on the influence of sedentary behavior on SA. The purpose of this analysis was to determine whether there is an association between sedentary behavior and successful aging, independent of physical activity levels.Methods. 9,478 older (M= 4,245;F= 5,233) and 10,060 middle-aged (M= 4.621;F= 5,439) adults from the Healthy Aging cycle of the Canadian Community Health Survey were analyzed. Multivariate logistic regressions were conducted with SA and its three components as outcomes while physical activity and sedentary behavior were entered as main exposures.Results. Among older adults, compared to those who were sedentary (4 hours or more/day), those who were moderately (2–4 hours/day) and least sedentary (<2 hours/day) were 38% (OR: 1.38; CI: 1.12–1.69) and 43% (OR: 1.43; CI: 1.23–1.67) more likely to age successfully, respectively. Among middle-aged adults, those who were least sedentary were 43% (OR: 1.43; CI: 1.25–1.63) more likely to age successfully.Conclusions. These novel findings suggest that sedentary activities are significantly associated with lower odds of SA among middle-aged and older adults, potentially in a dose-dependent manner.
Analysis of a System for Linear Fractional Differential Equations
Authors: Wang Fang , Liu Zhen-hai , Wang Ping
Published: September 2012

The main purpose of this paper is to obtain the unique solution of the constant coefficient homogeneous linear fractional differential equations and the constant coefficient nonhomogeneous linear fractional differential equations if P is a diagonal matrix and X(t) ∈ C1−q[t0, T] × C1−q[t0, T]×⋯×C1−q[t0, T] and prove the existence and uniqueness of these two kinds of equations for any P ∈ L(Rm) and X(t) ∈ C1−q[t0, T] × C1−q[t0, T]×⋯×C1−q[t0, T]. Then we give two examples to demonstrate the main results.
A Diagnostic Dilemma: Waldenström's Macroglobulinemia/Plasma Cell Leukemia
Authors: Sethi Bhawna , Butola K. S. , Kumar Yogesh
Published: September 2012

Waldenström's macroglobulinemia is a B-cell neoplasm characterized by infiltration of the bone marrow by a lymphoplasmacytic infiltrate and an IgM monoclonal gammopathy. It is an uncommon disease with overall incidence of approximately 3 per million persons per year, accounting for approximately 1% to 2% of all hematologic cancers. It has only one-sixth the estimated prevalence of plasma cell myeloma. Disease symptoms can be due to infiltration of bone marrow and other tissue sites by malignant lymphoplasmacytic cells or due to the effects of elevated serum IgM levels. However, patients may present with constitutional symptoms only or may be asymptomatic. In our case, patient presented with chief complaints of fatigability and dyspnoea and was misdiagnosed as plasma cell leukemia on peripheral blood film and bone marrow morphology, but turned out to be a case of Waldenström's macroglobulinemia on cytoflorometry. The patient was referred for chemotherapy but expired on 10th day of admission. The suspected cause of death was cardiorespiratory failure.
Social Activity and Cognitive Functioning Over Time: A Coordinated Analysis of Four Longitudinal Studies
Authors: Brown Cassandra L. , Gibbons Laura E. , Kennison Robert F. , Robitaille Annie , Lindwall Magnus , Mitchell Meghan B. , Shirk Steven D. , Atri Alireza , Cimino Cynthia R. , Benitez Andreana , MacDonald Stuart W. S. , Zelinski Elizabeth M. , Willis Sherry L. , Schaie K. Warner , Johansson Boo , Dixon Roger A. , Mungas Dan M. , Hofer Scott M. , Piccinin Andrea M.
Published: September 2012

Social activity is typically viewed as part of an engaged lifestyle that may help mitigate the deleterious effects of advanced age on cognitive function. As such, social activity has been examined in relation to cognitive abilities later in life. However, longitudinal evidence for this hypothesis thus far remains inconclusive. The current study sought to clarify the relationship between social activity and cognitive function over time using a coordinated data analysis approach across four longitudinal studies. A series of multilevel growth models with social activity included as a covariate is presented. Four domains of cognitive function were assessed: reasoning, memory, fluency, and semantic knowledge. Results suggest that baseline social activity is related to some, but not all, cognitive functions. Baseline social activity levels failed to predict rate of decline in most cognitive abilities. Changes in social activity were not consistently associated with cognitive functioning. Our findings do not provide consistent evidence that changes in social activity correspond to immediate benefits in cognitive functioning, except perhaps for verbal fluency.
Practical Tips for Construction of Custom Peptide Libraries and Affinity Selection by Using Commercially Available Phage Display Cloning Systems
Authors: Fukunaga Keisuke , Taki Masumi
Published: September 2012

Phage display technology is undoubtedly a powerful tool for affinity selection of target-specific peptide. Commercially available premade phage libraries allow us to take screening in the easiest way. On the other hand, construction of a custom phage library seems to be inaccessible, because several practical tips are absent in instructions. This paper focuses on what should be born in mind for beginners using commercially available cloning kits (Ph.D. with type 3 vector and T7Select systems for M13 and T7 phage, respectively). In the M13 system, Pro or a basic amino acid (especially, Arg) should be avoided at the N-terminus of peptide fused to gp3. In both systems, peptides containing odd number(s) of Cys should be designed with caution. Also, DNA sequencing of a constructed library before biopanning is highly recommended for finding unexpected bias.
Pilonidal Disease Mimicking Fistula-in-Ano in a 15-Year-Old Female
Authors: Iqbal Corey W. , Gasior Alessandra C. , Snyder Charles L.
Published: September 2012

Pilonidal disease typically presents with an abscess or intermittent pain and drainage in the sacrococcygeal region during the pubertal years. Further examination typically reveals pits in the midline of the sacrococcyx area due to entrapment of hair with recurrent entrapment, infection, and drainage. The following paper describes an unusual presentation of a pilonidal cyst with fissure and perianal drainage.
Bringing Top-End Endoscopy to Regional Australia: Hurdles and Benefits
Authors: Van Den Bogaerde J. , Sorrentino D.
Published: September 2012

This paper focuses on recent experience in setting up an endoscopy unit in a large regional hospital. The mix of endoscopy in three smaller hospitals, draining into the large hospital endoscopy unit, has enabled the authors to comment on practical and achievable steps towards creating best practice endoscopy in the regional setting. The challenges of using what is available from an infrastructural equipment and personnel setting are discussed. In a fast moving field such as endoscopy, new techniques have an important role to play, and some are indeed cost effective and have been shown to improve patient care. Some of the new techniques and technologies are easily applicable to smaller endoscopy units and can be easily integrated into the practice of working endoscopists. Cost effectiveness and patient care should always be the final arbiter of what is essential, as opposed to what is nice to have. Close cooperation between referral and peripheral centers should also guide these decisions.
Empirical Risk Analysis of Severe Reactor Accidents in Nuclear Power Plants after Fukushima
Authors: Kaiser Jan Christian
Published: September 2012

Many countries are reexamining the risks connected with nuclear power generation after the Fukushima accidents. To provide updated information for the corresponding discussion a simple empirical approach is applied for risk quantification of severe reactor accidents with International Nuclear and Radiological Event Scale (INES) level≥5. The analysis is based on worldwide data of commercial nuclear facilities. An empirical hazard of 21 (95% confidence intervals (CI) 4; 62) severe accidents among the world’s reactors in 100,000 years of operation has been estimated. This result is compatible with the frequency estimate of a probabilistic safety assessment for a typical pressurised power reactor in Germany. It is used in scenario calculations concerning the development in numbers of reactors in the next twenty years. For the base scenario with constant reactor numbers the time to the next accident among the world's 441 reactors, which were connected to the grid in 2010, is estimated to 11 (95% CI 3.7; 52) years. In two other scenarios a moderate increase or decrease in reactor numbers have negligible influence on the results. The time to the next accident can be extended well above the lifetime of reactors by retiring a sizeable number of less secure ones and by safety improvements for the rest.
Larval Diel Vertical Migration of the Marine GastropodKelletia kelletii(Forbes, 1850)
Authors: Romero Melissa R. , Walker Kimberly M. , Cortez Carmen J. , Sanchez Yareli , Nelson Kimberly J. , Ortega Daisha C. , Smick Serra L. , Hoese William J. , Zacherl Danielle C.
Published: September 2012

Documenting larval behavior is critical for building an understanding of larval dispersal dynamics and resultant population connectivity. Nocturnal diel vertical migration (DVM), a daily migration towards the surface of the water column at night and downward during the day, can profoundly influence dispersal outcomes. Via laboratory experiments we investigated whether marine gastropodKelletia kelletiilarvae undergo nocturnal DVM and whether the behavior was influenced by the presence of light, ontogeny, and laboratory culturing column height. Larvae exhibited a daily migration pattern consistent with nocturnal diel vertical migration with lower average vertical positioning (ZCM) during day-time hours and higher vertical positioning at night-time hours. ZCM patterns varied throughout ontogeny; larvae became more demersal as they approached competency. There was no effect of column height on larval ZCM. DVM behavior persisted in the absence of light, indicating a possible endogenous rhythm. Findings from field plankton tows corroborated laboratory nocturnal DVM findings; significantly moreK.kelletiiwere found in surface waters at midnight compared to at noon. Unraveling the timing of and the cues initiating DVM behavior inK.kelletiilarvae can help build predictive models of dispersal outcomes for this emerging fishery species.
Duality Fixed Point and Zero Point Theorems and Applications
Authors: Cheng Qingqing , Su Yongfu , Zhang Jingling
Published: September 2012

The following main results have been given. (1) Let E be a p‐uniformly convex Banach space and let T : E → E* be a (p − 1)‐L‐Lipschitz mapping with condition . Then T has a unique generalized duality fixed point x* ∈ E and (2) let E be a p‐uniformly convex Banach space and let T : E → E* be a q‐α‐inverse strongly monotone mapping with conditions 1/p + 1/q = 1, 0 < (q/(q − 1)c2) q−1 < α. Then T has a unique generalized duality fixed point x* ∈ E. (3) Let E be a 2‐uniformly smooth and uniformly convex Banach space with uniformly convex constant c and uniformly smooth constant b and let T : E → E* be a L‐lipschitz mapping with condition 0 < 2b/c2 < 1. Then T has a unique zero point x*. These main results can be used for solving the relative variational inequalities and optimal problems and operator equations.
A Robust Baseband Demodulator for ISO 18000-6C RFID Reader Systems
Authors: Jin Cheng , Cho Sung Ho
Published: September 2012

One key challenge for ultra-high frequency (UHF) radio-frequency identification (RFID) reader design is to demodulate the weak tag response signal which tends to be easily distorted and has considerable frequency deviations. In this paper, a baseband demodulator based on a matched filter (MF) is proposed to enhance the reliability of signal processing for the EPCglobal Class-1 Generation-2 (Gen2) RFID reader systems. The proposed demodulator is very robust against strong signal distortions and large frequency deviations happening on the received backscattered signal from a passive RFID tag. The validity and usefulness is demonstrated by both computer simulations and implementation experiments.
Numerical Solutions of a Variable‐Order Fractional Financial System
Authors: Ma Shichang , Xu Yufeng , Yue Wei
Published: September 2012

The numerical solution of a variable‐order fractional financial system is calculated by using the Adams‐Bashforth‐Moulton method. The derivative is defined in the Caputo variable‐order fractional sense. Numerical examples show that the Adams‐Bashforth‐Moulton method can be applied to solve such variable‐order fractional differential equations simply and effectively. The convergent order of the method is also estimated numerically. Moreover, the stable equilibrium point, quasiperiodic trajectory, and chaotic attractor are found in the variable‐order fractional financial system with proper order functions.
Uniform Approximate Estimation for Nonlinear Nonhomogenous Stochastic System with Unknown Parameter
Authors: Kan Xiu , Shu Huisheng
Published: September 2012

The error bound in probability between the approximate maximum likelihood estimator (AMLE) and the continuous maximum likelihood estimator (MLE) is investigated for nonlinear nonhomogenous stochastic system with unknown parameter. The rates of convergence of the approximations for Itô and ordinary integral are introduced under some regular assumptions. Based on these results, the in probability rate of convergence of the approximate log‐likelihood function to the true continuous log‐likelihood function is studied for the nonlinear nonhomogenous stochastic system involving unknown parameter. Finally, the main result which gives the error bound in probability between the ALME and the continuous MLE is established.
Usefulness of Whole-Body Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in Patients with Neurofibromatosis Type 1: A Systematic Review
Authors: Treglia Giorgio , Taralli Silvia , Bertagna Francesco , Salsano Marco , Muoio Barbara , Novellis Pierluigi , Vita Maria Letizia , Maggi Fabio , Giordano Alessandro
Published: September 2012

Aim. To systematically review the role of positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose (FDG) in patients with neurofibromatosis type 1 (NF1).Methods. A comprehensive literature search of published studies regarding FDG-PET and PET/CT in patients with NF1 was performed. No beginning date limit and language restriction were used; the search was updated until December 2011. Only those studies or subsets in studies including whole-body FDG-PET or PET/CT scans performed in patients with NF1 were included.Results. We identified 12 studies including 352 NF1 patients. Qualitative evaluation was performed in about half of the studies and semiquantitative analysis, mainly based on different values of SUV cutoff, in the others. Most of the studies evaluated the role of FDG-PET for differentiating benign from malignant peripheral nerve sheath tumors (MPNSTs). Malignant lesions were detected with a sensitivity ranging between 100% and 89%, but with lower specificity, ranging between 100% and 72%. Moreover, FDG-PET seems to be an important imaging modality for predicting the progression to MPNST and the outcome in patients with MPNST. Two studies evaluated the role of FDG-PET in pediatric patients with NF1.Conclusions. FDG-PET and PET/CT are useful methods to identify malignant change in neurogenic tumors in NF1 and to discriminate malignant from benign neurogenic lesions.