bluuebunny/crossref_metadata_2025 huggingface dataset:
Discrete-Decision Continuous-Actuation Control: Balance of an Inverted Pendulum and Pumping a Pendulum Swing
Authors: Bhounsule Pranav A. , Ruina Andy , Stiesberg Gregg
Published: October 2014

In some practical control problems of essentially continuous systems, the goal is not to tightly track a trajectory in state space, but only some aspects of the state at various points along the trajectory, and possibly only loosely. Here, we show examples in which classical discrete-control approaches can provide simple, low input-, and low output- bandwidth control of such systems. The sensing occurs at discrete state- or time-based events. Based on the state at the event, we set a small set of control parameters. These parameters prescribe features, e.g., amplitudes of open-loop commands that, assuming perfect modeling, force the system to, or toward, goal points in the trajectory. Using this discrete decision continuous actuation (DDCA) control approach, we demonstrate stabilization of two examples: (1) linear “dead-beat” control of a time delayed linearized inverted pendulum and (2) pumping of a hanging pendulum. Advantages of this approach include: It is computationally cheap compared to real-time control or online optimization; it can handle long time delays; it can fully correct disturbances in finite time (dead-beat control); it can be simple, using few control gains and set points and limited sensing; and it provides low bandwidth for both sensing and actuator commands. We have found the approach is useful for controlling robotic walking.
The image quality of ion computed tomography at clinical imaging dose levels
Authors: Hansen David C. , Bassler Niels , Sørensen Thomas Sangild , Seco Joao
Published: October 2014

Purpose:

Accurately predicting the range of radiotherapy ions in vivo is important for the precise delivery of dose in particle therapy. Range uncertainty is currently the single largest contribution to the dose margins used in planning and leads to a higher dose to normal tissue. The use of ion CT has been proposed as a method to improve the range uncertainty and thereby reduce dose to normal tissue of the patient. A wide variety of ions have been proposed and studied for this purpose, but no studies evaluate the image quality obtained with different ions in a consistent manner. However, imaging doses ion CT is a concern which may limit the obtainable image quality. In addition, the imaging doses reported have not been directly comparable with x‐ray CT doses due to the different biological impacts of ion radiation. The purpose of this work is to develop a robust methodology for comparing the image quality of ion CT with respect to particle therapy, taking into account different reconstruction methods and ion species.

Methods:

A comparison of different ions and energies was made. Ion CT projections were simulated for five different scenarios: Protons at 230 and 330 MeV, helium ions at 230 MeV/u, and carbon ions at 430 MeV/u. Maps of the water equivalent stopping power were reconstructed using a weighted least squares method. The dose was evaluated via a quality factor weighted CT dose index called the CT dose equivalent index (CTDEI). Spatial resolution was measured by the modulation transfer function. This was done by a noise‐robust fit to the edge spread function. Second, the image quality as a function of the number of scanning angles was evaluated for protons at 230 MeV. In the resolution study, the CTDEI was fixed to 10 mSv, similar to a typical x‐ray CT scan. Finally, scans at a range of CTDEI's were done, to evaluate dose influence on reconstruction error.

Results:

All ions yielded accurate stopping power estimates, none of which were statistically different from the ground truth image. Resolution (as defined by the modulation transfer function = 10% point) was the best for the helium ions (18.21 line pairs/cm) and worst for the lower energy protons (9.37 line pairs/cm). The weighted quality factor for the different ions ranged from 1.23 for helium to 2.35 for carbon ions. For the angle study, a sharp increase in absolute error was observed below 45 distinct angles, giving the impression of a threshold, rather than smooth, limit to the number of angles.

Conclusions:

The method presented for comparing various ion CT modalities is feasible for practical use. While all studied ions would improve upon x‐ray CT for particle range estimation, helium appears to give the best results and deserves further study for imaging.
Identification of Inhibitors of a Bacterial Sigma Factor Using a New High-Throughput Screening Assay
Authors: El-Mowafi S. A. , Sineva E. , Alumasa J. N. , Nicoloff H. , Tomsho J. W. , Ades S. E. , Keiler K. C.
Published: October 2014

Gram-negative bacteria are formidable pathogens because their cell envelope presents an adaptable barrier to environmental and host-mediated challenges. The stress response pathway controlled by the alternative sigma factor σ
E
is critical for maintenance of the cell envelope. Because σ
E
is required for the virulence or viability of several Gram-negative pathogens, it might be a useful target for antibiotic development. To determine if small molecules can inhibit the σ
E
pathway, and to permit high-throughput screening for antibiotic lead compounds, a σ
E
activity assay that is compatible with high-throughput screening was developed and validated. The screen employs a biological assay with positive readout. An
Escherichia coli
strain was engineered to express yellow fluorescent protein (YFP) under negative regulation by the σ
E
pathway, such that inhibitors of the pathway increase the production of YFP. To validate the screen, the reporter strain was used to identify σ
E
pathway inhibitors from a library of cyclic peptides. Biochemical characterization of one of the inhibitory cyclic peptides showed that it binds σ
E
, inhibits RNA polymerase holoenzyme formation, and inhibits σ
E
-dependent transcription
in vitro
. These results demonstrate that alternative sigma factors can be inhibited by small molecules and enable high-throughput screening for inhibitors of the σ
E
pathway.
Complete Genome Sequence of Cell Culture-Attenuated Guinea Pig Cytomegalovirus Cloned as an Infectious Bacterial Artificial Chromosome
Authors: Yang Dongmei , Alam Zohaib , Cui Xiaohong , Chen Michael , Sherrod Carly J. , McVoy Michael A. , Schleiss Mark R. , Dittmer Dirk P.
Published: October 2014

The complete genome sequence of attenuated guinea pig cytomegalovirus cloned as bacterial artificial chromosome N13R10 was determined. Comparison to pathogenic salivary gland-derived virus revealed 13 differences, 1 of which disrupted overlapping open reading frames encoding GP129 and GP130. Attenuation of N13R10 may arise from an inability to express GP129 and/or GP130.
Complete Genome Sequences of Fish Pathogenic Weissella ceti Strains WS74 and WS105
Authors: Figueiredo H. C. P. , Leal C. A. G. , Dorella F. A. , Carvalho A. F. , Soares S. C. , Pereira F. L. , Azevedo V. A. C.
Published: October 2014

We describe here the genome sequencing and annotation of
Weissella ceti
strains WS74 and WS105, isolated from diseased rainbow trout in Brazil. The two genomes were sequenced with an Ion Torrent personal genome machine (PGM) using a fragment library. The genomes of strains WS74 and WS105 consist of circular chromosomes 1,389,513 bp and 1,390,396 bp long, respectively, both presenting a G+C content of 40.75%.
Complete Genome Sequence of a Dimethyl Sulfide-Utilizing Bacterium, Acinetobacter guillouiae Strain 20B (NBRC 110550)
Authors: Yee LiiMien , Hosoyama Akira , Ohji Shoko , Tsuchikane Keiko , Shimodaira Jun , Yamazoe Atsushi , Fujita Nobuyuki , Suzuki-Minakuchi Chiho , Nojiri Hideaki
Published: October 2014

Acinetobacter guillouiae
strain 20B can utilize dimethyl sulfide (DMS) as the sole sulfur source and degrade chloroethylenes. We report here the complete 4,648,418-bp genome sequence for this strain, which contains 4,367 predicted coding sequences (CDSs), including a well-characterized DMS degradative operon.
Draft Genome Sequence of the Ionic Liquid-Tolerant Bacterium Bacillus amyloliquefaciens CMW1
Authors: Kurata Atsushi , Hirose Yuu , Misawa Naomi , Hurunaka Kohei , Kishimoto Noriaki
Published: October 2014

Here, we report the draft genome sequence of an ionic liquid-tolerant bacterium,
Bacillus amyloliquefaciens
CMW1, which is newly isolated from a Japanese fermented soybean paste. The genome sequence will allow for a characterization of the molecular mechanism of its ionic liquid tolerance.
RelA Inhibits Bacillus subtilis Motility and Chaining
Authors: Ababneh Qutaiba O. , Herman Jennifer K.
Published: October 2014

The nucleotide second messengers pppGpp and ppGpp [(p)ppGpp] are responsible for the global downregulation of transcription, translation, DNA replication, and growth rate that occurs during the stringent response. More recent studies suggest that (p)ppGpp is also an important effector in many nonstringent processes, including virulence, persister cell formation, and biofilm production. In
Bacillus subtilis
, (p)ppGpp production is primarily determined by the net activity of RelA, a bifunctional (p)ppGpp synthetase/hydrolase, and two monofunctional (p)ppGpp synthetases, YwaC and YjbM. We observe that in
B. subtilis
, a
relA
mutant grows exclusively as unchained, motile cells, phenotypes regulated by the alternative sigma factor SigD. Our data indicate that the
relA
mutant is trapped in a SigD “on” state during exponential growth, implicating RelA and (p)ppGpp levels in the regulation of cell chaining and motility in
B. subtilis
. Our results also suggest that minor variations in basal (p)ppGpp levels can significantly skew developmental decision-making outcomes.
Structure-Based Functional Characterization of Repressor of Toxin (Rot), a Central Regulator of Staphylococcus aureus Virulence
Authors: Killikelly April , Benson Meredith A. , Ohneck Elizabeth A. , Sampson Jared M. , Jakoncic Jean , Spurrier Brett , Torres Victor J. , Kong Xiang-Peng
Published: October 2014

Staphylococcus aureus
is responsible for a large number of diverse infections worldwide. In order to support its pathogenic lifestyle,
S. aureus
has to regulate the expression of virulence factors in a coordinated fashion. One of the central regulators of the
S. aureus
virulence regulatory networks is the transcription factor repressor of toxin (Rot). Rot plays a key role in regulating
S. aureus
virulence through activation or repression of promoters that control expression of a large number of critical virulence factors. However, the mechanism by which Rot mediates gene regulation has remained elusive. Here, we have determined the crystal structure of Rot and used this information to probe the contribution made by specific residues to Rot function. Rot was found to form a dimer, with each monomer harboring a winged helix-turn-helix (WHTH) DNA-binding motif. Despite an overall acidic pI, the asymmetric electrostatic charge profile suggests that Rot can orient the WHTH domain to bind DNA. Structure-based site-directed mutagenesis studies demonstrated that R
91
, at the tip of the wing, plays an important role in DNA binding, likely through interaction with the minor groove. We also found that Y
66
, predicted to bind within the major groove, contributes to Rot interaction with target promoters. Evaluation of Rot binding to different activated and repressed promoters revealed that certain mutations on Rot exhibit promoter-specific effects, suggesting for the first time that Rot differentially interacts with target promoters. This work provides insight into a precise mechanism by which Rot controls virulence factor regulation in
S. aureus
.
Value Driven Outcomes (VDO): a pragmatic, modular, and extensible software framework for understanding and improving health care costs and outcomes
Authors: Kawamoto Kensaku , Martin Cary J , Williams Kip , Tu Ming-Chieh , Park Charlton G , Hunter Cheri , Staes Catherine J , Bray Bruce E , Deshmukh Vikrant G , Holbrook Reid A , Morris Scott J , Fedderson Matthew B , Sletta Amy , Turnbull James , Mulvihill Sean J , Crabtree Gordon L , Entwistle David E , McKenna Quinn L , Strong Michael B , Pendleton Robert C , Lee Vivian S
Published: October 2014

Objective To develop expeditiously a pragmatic, modular, and extensible software framework for understanding and improving healthcare value (costs relative to outcomes).

Materials and methods In 2012, a multidisciplinary team was assembled by the leadership of the University of Utah Health Sciences Center and charged with rapidly developing a pragmatic and actionable analytics framework for understanding and enhancing healthcare value. Based on an analysis of relevant prior work, a value analytics framework known as Value Driven Outcomes (VDO) was developed using an agile methodology. Evaluation consisted of measurement against project objectives, including implementation timeliness, system performance, completeness, accuracy, extensibility, adoption, satisfaction, and the ability to support value improvement.

Results A modular, extensible framework was developed to allocate clinical care costs to individual patient encounters. For example, labor costs in a hospital unit are allocated to patients based on the hours they spent in the unit; actual medication acquisition costs are allocated to patients based on utilization; and radiology costs are allocated based on the minutes required for study performance. Relevant process and outcome measures are also available. A visualization layer facilitates the identification of value improvement opportunities, such as high-volume, high-cost case types with high variability in costs across providers. Initial implementation was completed within 6 months, and all project objectives were fulfilled. The framework has been improved iteratively and is now a foundational tool for delivering high-value care.

Conclusions The framework described can be expeditiously implemented to provide a pragmatic, modular, and extensible approach to understanding and improving healthcare value.
Congenitally corrected transposition of the great arteries in an 83-year-old asymptomatic patient: description and literature review
Authors: Placci Angelo , Lovato Luigi , Bonvicini Marco
Published: October 2014

We describe the case of an 83-year-old asymptomatic man followed in our centre. Transoesophageal echocardiography disclosed congenitally corrected transposition of great arteries (CCTGA) with no associated anomalies and only mild aortic regurgitation. Cardiac MR confirmed the diagnosis and revealed preserved systemic ventricle systolic function with a normal perfusional pathway. This report is a demonstration that CCTGA without associated anomalies can reach older life in an asymptomatic condition. This is the oldest asymptomatic living patient with CCTGA ever described.
Arthritis and adult respiratory distress syndrome: unusual presentations of typhoid fever
Authors: Dhakad Urmila , Das Siddharth K , Srivastva Durgesh , Nolkha Nilesh
Published: October 2014

A middle-aged woman presented with fever of 1-month duration along with bilateral knee joint pain, swelling and difficulty in walking for 2 weeks. The patient's Typhidot test was positive for IgM antibodies. Her Widal test was negative, and blood culture and synovial fluid culture were sterile. She was started on ceftriaxone, to which her fever initially responded. However, after 4 days of treatment her disease course was complicated by relapse of fever and acute respiratory distress syndrome (ARDS). This settled with respiratory support and addition of azithromycin. Following recovery from ARDS and fever, her persistent knee arthritis responded to intra-articular methyl prednisolone instillation.
Atraumatic sternum fracture
Authors: Abrahamsen Sebastian Ørskov , Madsen Christina Friis
Published: October 2014

The spine, pelvic bones and long bones of the lower extremities are common sites for insufficiency fractures. Cases of sternum insufficiency fractures have rarely been reported among elderly patients. Insufficiency fractures tend to occur in bones with decreased mechanical strength especially among elderly patients, in postmenopausal women and patients with underlying diseases. We describe a case of spontaneous sternum insufficiency fracture in a healthy man, with no known risk factors to fracture, or previous history of fractures. Sternum insufficiency fracture is a rare cause of chest pain. This case serves to remind the emergency physician to remain vigilant for other non-cardiac, non-pulmonary and non-traumatic causes of chest pain, especially among patients with known risk factors such as osteoporosis, chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus and patients on long-term steroid treatment. If diagnosed correctly, these patients can be discharged and treated as outpatients as this case emphasises.
Vasitis: the need for imaging and clinical acumen
Authors: Patel Kunal , Lamb Benjamin , Pathak Sandeep , Peters John
Published: October 2014

A 55-year-old man presented with an acute, painful groin mass with signs of sepsis. On examination, it was difficult to tell whether this was a strangulated hernia or a testicular torsion. Biochemical investigations revealed raised inflammatory markers and radiological investigations showed a rare inflammatory condition, vasitis, which could be mistaken for various other ‘surgical’ groin masses. This case report summarises the importance of realising the vast differential diagnoses that come with acute groin masses and how imaging can prevent unnecessary surgery.
Electronic properties of two-dimensional ZnO atomically sheet on Cu substrate: a first-principles study
Authors: Hussain Fayyaz , Imran M. , Cai Y. Q. , Ullah Hafeez , Shakoor Abdul , Rashid M. , Ahmad Ejaz , Ahmad S. A.
Published: October 2014

Bulk ZnO has traditionally been regarded as multifunctional materials for energy and optoelectronics applications. Recently, exploring this material at the nanoscale has been reported and seeking a proper substrate is highly desired. In this work, the structural and electronic properties of graphene like ZnO two-dimensional (2D) monolayer are investigated by first principles calculation based on density functional theory. The alignment of the valence and conduction bands of ZnO with the state of Cu substrate is analyzed. Particularly the attention has been focused on the establishment of a Schottky contact and interfacial charge transfer between the 2D ZnO monolayer and Cu substrate. It is predicted that the electronic charges are accumulated on the Zn and O atoms due to d–d hybridization between Cu and Zn . Our study reveals that the significant interaction between the ZnO and Cu can greatly modify the electronic properties of the ZnO and suggests potential applications in nanoelectronic devices.
Influence of the probe-sample interaction angle on image formation in apertureless scanning near field optical microscope
Authors: Merlo J. M. , Coello V. , Cortés R. , Aguilar J. F. , Flores-Rosas A.
Published: October 2014

Using the two-dimensional finite difference time domain method, we report on the image formation of an apertureless scanning near field optical microscope. It is found that the obtained images are influenced by the angle at which the probe interacts with a dielectric sample under total internal reflection illumination. The scanning probe is assumed to be a sharp silver tip with similar shape to those used in atomic force microscopy. We show that the near-field optical response produced by semi-circular and square imperfections are significantly affected with small (0°–10°) variations of the probe-sample interaction angle.
Thermodynamic properties of charged ideal spin-1 bosons in a trap under a magnetic field
Authors: Li Yushan
Published: October 2014

Thermodynamics of trapped charged ideal spin-1 bosons confined in a magnetic field are investigated within semi-classical approximation and truncated-summation approach. It is shown that the critical temperature increases slightly at the first, and then decreases slowly with increasing external magnetic field. Charged spin-1 Bose gases present a crossover from diamagnetism to paramagnetism as the spin factor increases. Charged spin-1 Bose gases exhibit distinct thermodynamic behaviors from the spinless case.
Multiscaling and Stock Market Efficiency in China
Authors: Thiele Thomas A.
Published: October 2014

China has taken important steps to reform its economy and capital markets in the past 20 years. Despite these efforts there is a lack of quantitative evidence on how these measures have impacted price returns in the stock exchanges. The purpose of this research was to determine the randomness of Chinese equity returns and to measure the scaling property of volatility over time. The main assumption of the Efficient Market Hypothesis is that security returns follow the path of a random walk and that volatility scales with the square root of time. This notion was tested by analyzing daily stock returns of the Shanghai- and Shenzhen Composite Indexes between 1990 and 2013. The Kolmogorov–Smirnov (KS) test rejected the log-normal distribution and random walk hypothesis. The measured Hurst exponents revealed a multiscaling property of fractal Brownian motion and indicated the presence of long-range dependence. The findings also showed that the degree of persistence and cycle length has reduced over time.
Random Walks in the Presence of Absorbing Barriers in Parrondo's Games
Authors: Yang Liu , Zheng Kai-Xuan , Xie Neng-Gang , Ye Ye , Wang Lu
Published: October 2014

For a multi-agent spatial Parrondo's model that it is composed of games A and B, we use the discrete time Markov chains to derive the probability transition matrix. Then, we respectively deduce the stationary distribution for games A and B played individually and the randomized combination of game A + B. We notice that under a specific set of parameters, two absorbing states instead of a fixed stationary distribution exist in game B. However, the randomized game A + B can jump out of the absorbing states of game B and has a fixed stationary distribution because of the "agitating" role of game A. Moreover, starting at different initial states, we deduce the probabilities of absorption at the two absorbing barriers.
EFFECTS OF TRANSVERSE SHEAR AND NORMAL STRAINS ON FG PLATES RESTING ON ELASTIC FOUNDATIONS UNDER HYGRO-THERMO-MECHANICAL LOADING
Authors: ZENKOUR A. M. , ALLAM M. N. M. , RADWAN A. F.
Published: October 2014

The influence of temperature and moisture on the bending behavior of composite functionally graded material (FGM) plates resting on elastic foundations is investigated. A transverse shear and normal deformation theory are used with five unknown functions as opposed to six or even greater numbers in the case of other shear and normal deformation theories. An accurate solution is presented in the hygrothermal response of the FG plate with simply-supported edges and resting on elastic foundations. The interaction between the plate and the elastic foundations is considered and included in the equilibrium equations. The influences of Winkler and Pasternak foundation parameters, temperature, moisture concentration, thickness stretching, shear deformation, plate aspect ratio, side-to-thickness ratio, and volume fraction distribution on the plate bending characteristics are studied in detail. Numerical results for the hygro-thermo-mechanical response of the FG rectangular plates is investigated and some of them are compared with those available in the literature.
Harnessing ISA diversity
Authors: Venkat Ashish , Tullsen Dean M.
Published: October 2014

Heterogeneous multicore architectures have the potential for high performance and energy efficiency. These architectures may be composed of small power-efficient cores, large high-performance cores, and/or specialized cores that accelerate the performance of a particular class of computation. Architects have explored multiple dimensions of heterogeneity, both in terms of micro-architecture and specialization. While early work constrained the cores to share a single ISA, this work shows that allowing heterogeneous ISAs further extends the effectiveness of such architectures

This work exploits the diversity offered by three modern ISAs: Thumb, x86-64, and Alpha. This architecture has the potential to outperform the best single-ISA heterogeneous architecture by as much as 21%, with 23% energy savings and a reduction of 32% in Energy Delay Product.
The dirty-block index
Authors: Seshadri Vivek , Bhowmick Abhishek , Mutlu Onur , Gibbons Phillip B. , Kozuch Michael A. , Mowry Todd C.
Published: October 2014

On-chip caches maintain multiple pieces of metadata about each cached block---e.g., dirty bit, coherence information, ECC. Traditionally, such metadata for each block is stored in the corresponding tag entry in the tag store. While this approach is simple to implement and scalable, it necessitates a full tag store lookup for any metadata query---resulting in high latency and energy consumption. We find that this approach is inefficient and inhibits several cache optimizations.

In this work, we propose a new way of organizing the dirty bit information that enables simpler and more efficient implementations of several optimizations. In our proposed approach, we remove the dirty bits from the tag store and organize it differently in a separate structure, which we call the Dirty-Block Index (DBI). The organization of DBI is simple: it consists of multiple entries, each corresponding to some row in DRAM. A bit vector in each entry tracks whether or not each block in the corresponding DRAM row is dirty

We demonstrate the benfits of DBI by using it to simultaneously and efficiently implement three optimizations proposed by prior work: 1) Aggressive DRAM-aware writeback, 2) Bypassing cache lookups, and 3) Heterogeneous ECC for clean/dirty blocks. DBI, with all three optimizations enabled, improves performance by 31% compared to the baseline (by 6% compared to the best previous mechanism) while reducing overall cache area cost by 8% compared to prior approaches.
Going vertical in memory management
Authors: Liu Lei , Li Yong , Cui Zehan , Bao Yungang , Chen Mingyu , Wu Chengyong
Published: October 2014

Many emerging applications from various domains often exhibit heterogeneous memory characteristics. When running in combination on parallel platforms, these applications present a daunting variety of workload behaviors that challenge the effectiveness of any memory allocation strategy. Prior partitioning-based or random memory allocation schemes typically manage only one level of the memory hierarchy and often target specific workloads.

To handle diverse and dynamically changing memory and cache allocation needs, we augment existing "horizontal" cache/DRAM bank partitioning with vertical partitioning and explore the resulting multi-policy space. We study the performance of these policies for over 2000 workloads and correlate the results with application characteristics via a data mining approach. Based on this correlation we derive several practical memory allocation rules that we integrate into a unified multi-policy framework to guide resources partitioning and coalescing for dynamic and diverse multiprogrammed/ threaded workloads. We implement our approach in Linux kernel 2.6.32 as a restructured page indexing system plus a series of kernel modules. Extensive experiments show that, in practice, our framework can select proper memory allocation policy and consistently outperforms the unmodified Linux kernel, achieving up to 11% performance gains compared to prior techniques
Fine-grain task aggregation and coordination on GPUs
Authors: Orr Marc S. , Beckmann Bradford M. , Reinhardt Steven K. , Wood David A.
Published: October 2014

In general-purpose graphics processing unit (GPGPU) computing, data is processed by concurrent threads execut-ing the same function. This model, dubbed single-instruction/multiple-thread (SIMT), requires programmers to coordinate the synchronous execution of similar opera-tions across thousands of data elements. To alleviate this programmer burden, Gaster and Howes outlined the chan-nel abstraction, which facilitates dynamically aggregating asynchronously produced fine-grain work into coarser-grain tasks. However, no practical implementation has been proposed

To this end, we propose and evaluate the first channel im-plementation. To demonstrate the utility of channels, we present a case study that maps the fine-grain, recursive task spawning in the Cilk programming language to channels by representing it as a flow graph. To support data-parallel recursion in bounded memory, we propose a hardware mechanism that allows wavefronts to yield their execution resources. Through channels and wavefront yield, we im-plement four Cilk benchmarks. We show that Cilk can scale with the GPU architecture, achieving speedups of as much as 4.3x on eight compute units
Enabling preemptive multiprogramming on GPUs
Authors: Tanasic Ivan , Gelado Isaac , Cabezas Javier , Ramirez Alex , Navarro Nacho , Valero Mateo
Published: October 2014

GPUs are being increasingly adopted as compute accelerators in many domains, spanning environments from mobile systems to cloud computing. These systems are usually running multiple applications, from one or several users. However GPUs do not provide the support for resource sharing traditionally expected in these scenarios. Thus, such systems are unable to provide key multiprogrammed workload requirements, such as responsiveness, fairness or quality of service.

In this paper, we propose a set of hardware extensions that allow GPUs to efficiently support multiprogrammed GPU workloads. We argue for preemptive multitasking and design two preemption mechanisms that can be used to implement GPU scheduling policies. We extend the architecture to allow concurrent execution of GPU kernels from different user processes and implement a scheduling policy that dynamically distributes the GPU cores among concurrently running kernels, according to their priorities. We extend the NVIDIA GK110 (Kepler) like GPU architecture with our proposals and evaluate them on a set of multiprogrammed workloads with up to eight concurrent processes. Our proposals improve execution time of high-priority processes by 15.6x, the average application turnaround time between 1.5x to 2x, and system fairness up to 3.4x
Memory persistency
Authors: Pelley Steven , Chen Peter M. , Wenisch Thomas F.
Published: October 2014

Emerging nonvolatile memory technologies (NVRAM) promise the performance of DRAM with the persistence of disk. However, constraining NVRAM write order, necessary to ensure recovery correctness, limits NVRAM write concurrency and degrades throughput. We require new memory interfaces to minimally describe write constraints and allow high performance and high concurrency data structures. These goals strongly resemble memory consistency. Whereas memory consistency concerns the order that memory operations are observed between numerous processors, persistent memory systems must constrain the order that writes occur with respect to failure. We introduce memory persistency, a new approach to designing persistent memory interfaces, building on memory consistency. Similar to memory consistency, memory persistency models may be relaxed to improve performance. We describe the design space of memory persistency and desirable features that such a memory system requires. Finally, we introduce several memory persistency models and evaluate their ability to expose NVRAM write concurrency using two implementations of a persistent queue. Our results show that relaxed persistency models accelerate system throughput 30-fold by reducing NVRAM write constraints
Half-DRAM
Authors: Zhang Tao , Chen Ke , Xu Cong , Sun Guangyu , Wang Tao , Xie Yuan
Published: October 2014

DRAM memory is a major contributor for the total power consumption in modern computing systems. Consequently, power reduction for DRAM memory is critical to improve system-level power efficiency. Fine-grained DRAM architecture [1, 2] has been proposed to reduce the activation/ precharge power. However, those prior work either incurs significant performance degradation or introduces large area overhead. In this paper, we propose a novel memory architecture Half-DRAM, in which the DRAM array is reorganized to enable only half of a row being activated. The half-row activation can effectively reduce activation power and meanwhile sustain the full bandwidth one bank can provide. In addition, the half-row activation in Half-DRAM relaxes the power constraint in DRAM, and opens up opportunities for further performance gain. Furthermore, two half-row accesses can be issued in parallel by integrating the sub-array level parallelism to improve the memory level parallelism. The experimental results show that Half-DRAM can achieve both significant performance improvement and power reduction, with negligible design overhead
Replay debugging
Authors: Honarmand Nima , Torrellas Josep
Published: October 2014

Hardware-assisted Record and Deterministic Replay (RnR) of programs has been proposed as a primitive for debugging hard-to-repeat software bugs. However, simply providing support for repeatedly stumbling on the same bug does not help diagnose it. For bug diagnosis, developers typically want to modify the code, e.g., by creating and operating on new variables, or printing state. Unfortunately, this renders the RnR log inconsistent and makes Replay Debugging (i.e., debugging while using an RnR log for replay) dicey at best

This paper presents rdb, the first scheme for replay debugging that guarantees exact replay. rdb relies on two mechanisms. The first one is compiler support to split the instrumented application into two executables: one that is identical to the original program binary, and another that encapsulates all the added debug code. The second mechanism is a runtime infrastructure that replays the application and, without affecting it in any way, invokes the appropriate debug code at the appropriate locations. We describe an implementation of rdb based on LLVM and Pin, and show an example of how rdb's replay debugging helps diagnose a real bug
The Anthropology of Money and Finance: Between Ethnography and World History
Authors: Hart Keith , Ortiz Horacio
Published: October 2014

We review here recent developments in the anthropology of money and finance, listing its achievements, shortcomings, and prospects, while referring back to the discipline's founders a century ago. We take our departure from the work of Marcel Mauss and Karl Polanyi, both of whom combined openness to ethnographic research with a vision of world history as a whole. Since the 1960s, anthropologists have tended to restrict themselves to niche fields and marginal debates. The anthropological study of money and ethnographies of finance, in particular, have been the focus of much research since the 1980s. Despite taking on new objects and directions, anthropologists still find it difficult to connect their situated analyses with global processes and world history. We propose some conceptual and empirical directions for research that would seek to overcome these limitations by integrating ethnography more closely with human history, while stressing the importance of money in shaping world society and attempts to reform it.
Citational Practices: Knowledge, Personhood, and Subjectivity
Authors: Goodman Jane E. , Tomlinson Matt , Richland Justin B.
Published: October 2014

Citation is a foundational dimension of human language and social life. Citational practices attribute utterances to distinct speakers, beings, or texts. They also connect temporalities, joining past, present, and future discourses, documents, and performance practices. In so doing, citational practices play a pivotal role in linking particular articulations of subjectivity to wider formations of cultural knowledge and authority. We explore how this linkage operates via production formats, participant structures, genre conventions, and ideologies of personhood. We then consider approaches to citation in the domain of legal discourse, an arena that relies on specific, patterned forms of citation that are historically rooted, institutionally perpetuated, and subjectively reenacted.
Environmental Issues in Australia
Authors: Hobday Alistair J. , McDonald Jan
Published: October 2014

Australia is a mineral-rich country with low and variable rainfall and, hence, biological productivity, as well as a predominately coastal population. Since European settlement in 1788, a range of landscape impacts, species introductions, and freshwater conflicts have led to serious environmental issues. Contemporary drivers of environmental change include population growth and associated development; water use for food production; resource extraction by the fishery, forestry, mining, and oil and gas industries; and climate change. A range of international agreements have influenced domestic environmental policy, culminating in Australia's foremost piece of environmental legislation, the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. Despite sound legislative instruments and policy intentions, a range of contemporary environmental issues associated with coal seam gas extraction, freshwater allocation, fisheries, and climate change illustrate that shortcomings in resolving environmental issues and obstacles remain with regard to improving the status of the environment. Given the increasing pressures on the environment, greater oversight and efficient enforcement are needed, particularly given population projections and plans for economic development.
Carbon Dioxide Capture and Storage: Issues and Prospects
Authors: de Coninck Heleen , Benson Sally M.
Published: October 2014

Almost 20 years ago, the first CO2 capture and storage (CCS) project began injecting CO2 into a deep geological formation in an offshore aquifer. Relevant science has advanced in areas such as chemical engineering, geophysics, and social psychology. Governments have generously funded demonstrations. As a result, a handful of industrial-scale CCS projects are currently injecting about 15 megatons of CO2 underground annually that contribute to climate change mitigation. However, CCS is struggling to gain a foothold in the set of options for dealing with climate change. This review explores why and discusses critical conditions for CCS to emerge as a viable mitigation option. Explanations for this struggle include the absence of government action on climate change, economic crisis–induced low carbon prices, public skepticism, increasing costs, and advances in other options including renewables and shale gas. Climate change action is identified as a critical condition for progress in CCS, in addition to community support, safe storage, robust policy support, and favorable CCS market conditions.
3D curvature of muscle fascicles in triceps surae
Authors: Rana Manku , Hamarneh Ghassan , Wakeling James M.
Published: October 2014

Muscle fascicles curve along their length, with the curvatures occurring around regions of high intramuscular pressure, and are necessary for mechanical stability. Fascicles are typically considered to lie in fascicle planes that are the planes visualized during dissection or two-dimensional (2D) ultrasound scans. However, it has previously been predicted that fascicles must curve in three-dimensional (3D) and thus the fascicle planes may actually exist as 3D sheets. 3D fascicle curvatures have not been explored in human musculature. Furthermore, if the fascicles do not lie in 2D planes, then this has implications for architectural measures that are derived from 2D ultrasound scans. The purpose of this study was to quantify the 3D curvatures of the muscle fascicles and fascicle sheets within the triceps surae muscles and to test whether these curvatures varied among different contraction levels, muscle length, and regions within the muscle. Six male subjects were tested for three torque levels (0, 30, and 60% maximal voluntary contraction) and four ankle angles (−15, 0, 15, and 30° plantar flexion), and fascicles were imaged using 3D ultrasound techniques. The fascicle curvatures significantly increased at higher ankle torques and shorter muscle lengths. The fascicle sheet curvatures were of similar magnitude to the fascicle curvatures but did not vary between contractions. Fascicle curvatures were regionalized within each muscle with the curvature facing the deeper aponeuroses, and this indicates a greater intramuscular pressure in the deeper layers of muscles. Muscle architectural measures may be in error when using 2D images for complex geometries such as the soleus.
Specific modulation of spinal and cortical excitabilities during lengthening and shortening submaximal and maximal contractions in plantar flexor muscles
Authors: Duclay Julien , Pasquet Benjamin , Martin Alain , Duchateau Jacques
Published: October 2014

This study investigated the influence of the torque produced by plantar flexor muscles on cortical and spinal excitability during lengthening and shortening voluntary contractions. To that purpose, modulations of motor-evoked potential (MEP) and Hoffmann (H) reflex were compared in the soleus (SOL) and medial gastrocnemius (MG) during anisometric submaximal and maximal voluntary contraction (MVC) of the plantar flexor muscles. For the submaximal shortening and lengthening contractions, the target torque was set at 50% of their respective MVC force. The results indicate that the amplitudes of both MEP and H-reflex responses, normalized to the maximal M wave, were significantly ( P < 0.05) lower during lengthening compared with shortening submaximal contraction. For these two parameters, the reduction reached, respectively, 22.1 and 31.9% for the SOL and 34.5 and 29.3% for the MG. During MVC, normalized MEP and H reflex of the SOL were both reduced significantly by 19.9% ( P < 0.05) and 29.9% ( P < 0.001) during lengthening and shortening contraction, respectively, whereas no significant change ( P > 0.05) was observed for MG. In addition, the silent period in the ongoing electromyogram (EMG) activity following the MEP was significantly ( P < 0.01) briefer during lengthening than shortening contractions but did not differ ( P > 0.05) between contraction intensities and muscles. Together, these results indicate that cortical and spinal mechanisms involved in the modulation of muscle activation during shortening and lengthening contractions differ between synergistic muscles according to the torque produced. Data further document previous studies reporting that the specific modulation of muscle activation during lengthening contraction is not torque dependent.
Mitochondrial cytochromecoxidase and control of energy metabolism: measurements in suspensions of isolated mitochondria
Authors: Wilson David F. , Harrison David K. , Vinogradov Andrei
Published: October 2014

Cytochrome c oxidase is the enzyme responsible for oxygen consumption by mitochondrial oxidative phosphorylation and coupling site 3 of oxidative phosphorylation. In this role it determines the cellular rate of ATP synthesis by oxidative phosphorylation and is the key to understanding how energy metabolism is regulated. Four electrons are required for the reduction of oxygen to water, and these are provided by the one-electron donor, cytochrome c. The rate of oxygen consumption (ATP synthesis) is dependent on the fraction of cytochrome c reduced (fred), oxygen pressure (pO2), energy state ([ATP]/[ADP][Pi]), and pH. In coupled mitochondria (high energy state) and pO2>60 torr, the rate increases in an exponential-like fashion with increasing fred. When the dependence on fredis fitted to the equation rate = a(fred)b, a decreased from 100 to near 20, and b increased from 1.3 to 4 as the pH of the medium increased from 6.5 to 8.3. During oxygen depletion from the medium fredprogressively increases and the rate of respiration decreases. The respiratory rate falls to ½ (P50) by about 1.5 torr, at which point fredis substantially increased. The metabolically relevant dependence on pO2is obtained by correcting for the increase in fred, in which case the P50is 12 torr. Adding an uncoupler of oxidative phosphorylation eliminates the dependence of the cytochrome c oxidase activity on pH and energy state. The respiratory rate becomes proportional to fredand the P50decreases to less than 1 torr.
Strength of Footing with Punching Shear Preventers
Authors: Lee Sang-Sup , Moon Jiho , Park Keum-Sung , Bae Kyu-Woong
Published: October 2014

The punching shear failure often governs the strength of the footing-to-column connection. The punching shear failure is an undesirable failure mode, since it results in a brittle failure of the footing. In this study, a new method to increase the strength and ductility of the footing was proposed by inserting the punching shear preventers (PSPs) into the footing. The validation and effectiveness of PSP were verified through a series of experimental studies. The nonlinear finite element analysis was then performed to demonstrate the failure mechanism of the footing with PSPs in depth and to investigate the key parameters that affect the behavior of the footing with PSPs. Finally, the design recommendations for the footing with PSPs were suggested.
Phytochemical Analysis, Antioxidant, Antistress, and Nootropic Activities of Aqueous and Methanolic Seed Extracts of Ladies Finger (Abelmoschus esculentusL.) in Mice
Authors: Doreddula Sathish Kumar , Bonam Srinivasa Reddy , Gaddam Durga Prasad , Desu Brahma Srinivasa Rao , Ramarao Nadendla , Pandy Vijayapandi
Published: October 2014

Abelmoschus esculentusL. (ladies finger, okra) is a well-known tropical vegetable, widely planted from Africa to Asia and from South Europe to America. In the present study, we investigated thein vitroantioxidant capacity andin vivoprotective effect of the aqueous and methanolic seed extracts ofAbelmoschus esculentusagainst scopolamine-induced cognitive impairment using passive avoidance task and acute restraining stress-induced behavioural and biochemical changes using elevated plus maze (EPM) and forced swimming test (FST) in mice. Our results demonstrated that the pretreatment of mice with aqueous and methanolic seed extracts ofAbelmoschus esculentus(200 mg/kg, p.o.) for seven days significantly(P< 0.01)attenuated scopolamine-induced cognitive impairment in the passive avoidance test. In addition, these extracts significantly reduced the blood glucose, corticosterone, cholesterol, and triglyceride levels elevated by acute restraint stress and also significantly increased the time spent in open arm in EPM and decreased the immobility time in FST. It has also been revealed that these extracts showed a significant antioxidant activity and no signs of toxicity or death up to a dose of 2000 mg/kg, p.o. These results suggest that the seed extracts ofAbelmoschus esculentusL. possess antioxidant, antistress, and nootropic activities which promisingly support the medicinal values of ladies finger as a vegetable.
Aligned Magnetic Field, Radiation, and Rotation Effects on Unsteady Hydromagnetic Free Convection Flow Past an Impulsively Moving Vertical Plate in a Porous Medium
Authors: Naramgari Sandeep , Vangala Sugunamma , Penem Mohankrishna
Published: October 2014

We analyse the effects of aligned magnetic field, radiation, and rotation on unsteady hydromagnetic free convection flow of a viscous incompressible electrically conducting fluid past an impulsively moving vertical plate in a porous medium in presence of heat source. An exact solution of the governing equations in dimensionless form is obtained by Laplace transform technique in ramped temperature case. To compare the results obtained in this case with that of isothermal plate, the exact solution of the governing equations is also obtained for isothermal plate and results are discussed graphically in both ramped temperature and isothermal cases.