bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Interactions Between Indicated and Reciprocating Torques for the Development of a Torsional Behavior Model of the Powertrain
Authors: Ponti Fabrizio , Solieri Luca
Published: March 2009

Torque-based engine control systems usually employ a produced torque estimation feedback in order to verify that the strategy target torque has been met. Torque estimation can be performed using static maps describing the engine behaviour or using models describing the existing relationships between signals measured on the engine and the indicated torque produced. Signals containing information on the combustion development, suitable for this purpose, are, among other, the ion-current signal, the vibration signals obtained from accelerometers mounted on the engine block, or the instantaneous engine speed fluctuations. This paper presents the development and the identification process of an engine-driveline torsional behavior model that enables indicated torque estimation from instantaneous engine speed measurement. Particular attention has been devoted to the interactions between indicated and reciprocating torques, and their effects over instantaneous engine speed fluctuations. Indicated and reciprocating torques produce, in fact, opposite excitations on the driveline that show opposite effects on the engine speed waveform: for low engine speed usually indicated torque prevails, while the opposite applies for higher engine speed. In order to correctly estimate indicated torque from engine speed measurement it is therefore necessary to correctly evaluate the reciprocating torque contribution. Reciprocating torque is usually described using a waveform as a function of crank angle, while its amplitude depends on the value of the reciprocating masses. As mentioned before, knowledge of the reciprocating masses is fundamental in order to obtain correct estimation of the indicated torque. The identification process that has been setup for the engine-driveline torsional model enables to evaluate the relationship between torques applied to the engine and the corresponding engine speed waveform even without knowing the value of the reciprocating masses. In addition, once this model has been setup, it is possible to estimate with high precision the value of the reciprocating masses. Particular attention has been devoted also to the feasibility of the application of the identified model on-board for torque estimation; for this reason the model has been developed in a very simple form. The approach proved to be effective both on gasoline and diesel engine, both for engine mounted on a test cell and on-board, with different engine configurations. Examples of application are given for some of the configurations investigated.
Genetic Identification of the Bacteriocins Produced by
Enterococcus faecium
IT62 and Evidence that Bacteriocin 32 Is Identical to Enterocin IT
Authors: Izquierdo Esther , Cai Yimin , Marchioni Eric , Ennahar Saïd
Published: March 2009

Enterococcus faecium
IT62, a strain isolated from ryegrass in Japan, produces three bacteriocins (enterocins L50A, L50B, and IT) that have been previously purified and the primary structures of which have been determined by amino acid sequencing (E. Izquierdo, A. Bednarczyk, C. Schaeffer, Y. Cai, E. Marchioni, A. Van Dorsselaer, and S. Ennahar, Antimicrob. Agents Chemother., 52:1917-1923, 2008). Genetic analysis showed that the bacteriocins of
E. faecium
IT62 are plasmid encoded, but with the structural genes specifying enterocin L50A and enterocin L50B being carried by a plasmid (pTAB1) that is separate from the one (pTIT1) carrying the structural gene of enterocin IT. Sequencing analysis of a 1,475-bp region from pTAB1 identified two consecutive open reading frames corresponding, with the exception of 2 bp, to the genes
entL50A
and
entL50B
, encoding EntL50A and EntL50B, respectively. Both bacteriocins are synthesized without N-terminal leader sequences. Genetic analysis of a sequenced 1,380-bp pTIT1 fragment showed that the genes
entIT
and
entIM
, encoding enterocin IT and its immunity protein, respectively, were both found in
E. faecium
VRE200 for bacteriocin 32. Enterocin IT, a 6,390-Da peptide made up of 54 amino acids, has been previously shown to be identical to the C-terminal part of bacteriocin 32, a 7,998-Da bacteriocin produced by
E. faecium
VRE200 whose structure was deduced from its structural gene (T. Inoue, H. Tomita, and Y. Ike, Antimicrob. Agents Chemother., 50:1202-1212, 2006). By combining the biochemical and genetic data on enterocin IT, it was concluded that bacteriocin 32 is in fact identical to enterocin IT, both being encoded by the same plasmid-borne gene, and that the N-terminal leader peptide for this bacteriocin is 35 amino acids long and not 19 amino acids long as previously reported.
Pilot Pharmacokinetic Study of Human Immunodeficiency Virus-Infected Patients Receiving Tenofovir Disoproxil Fumarate (TDF): Investigation of Systemic and Intracellular Interactions between TDF and Abacavir, Lamivudine, or Lopinavir-Ritonavir
Authors: Pruvost Alain , Negredo Eugènia , Théodoro Frédéric , Puig Jordi , Levi Mikaël , Ayen Rafaela , Grassi Jacques , Clotet Bonaventura
Published: March 2009

Previous work has demonstrated the existence of systemic interaction between tenofovir (TFV) disoproxil fumarate (TDF) and didanosine as well as between TDF and lopinavir-ritonavir (LPV/r). Here we investigated TDF interactions with the nucleoside reverse transcriptase inhibitors (NRTIs) lamivudine (3TC) and abacavir (ABC), comparing both the concentrations of nucleoside/nucleotide reverse transcriptase inhibitors in plasma and the intracellular concentrations of their triphosphate metabolites (NRTI-TP) for human immunodeficiency virus-infected patients receiving these NRTIs with TDF and after 4 weeks of TDF interruption. We also looked at interactions between TDF-ABC and LPV/r, comparing patients receiving or not receiving LPV/r. Blood samples were taken at baseline and at 1, 2, and 4 h after dosing. Liquid chromatography-tandem mass spectrometry was used to measure NRTIs and NRTI-TPs. Statistical analyses were performed on pharmacokinetic parameters: the area under the concentration-time curve from 0 to 4 h (AUC0-4), the maximum concentration of the drug (Cmax), and the residual concentration of the drug at the end of the dosing interval (Ctrough) for plasma and the AUC0-4andCtroughfor intracellular data. Among the groups of patient discontinuing TDF, the very long intracellular half-life of elimination (150 h) of TFV-DP (the diphosphorylated metabolite of TFV, corresponding to a triphosphorylated species) was confirmed. Comparison between groups as well as the longitudinal study showed no significant systemic or intracellular interaction between TDF and ABC or 3TC. Significant differences were observed between patients receiving LVP/r and those receiving nevirapine. For ABC, plasma exposure was decreased (40%) under LVP/r, while, in contrast, plasma exposure to TFV was increased by 50% and the intracellular TFV-DP AUC0-4was increased by 59%. A trend for a gender effect was observed for TFV-DP at the intracellular level, with higher andCtroughvalues for women.
Immunoglobulin E (IgE) Responses to Paramyosin Predict Resistance to Reinfection withSchistosoma japonicumand Are Attenuated by IgG4
Authors: Jiz Mario , Friedman Jennifer F. , Leenstra Tjalling , Jarilla Blanca , Pablo Archie , Langdon Gretchen , Pond-Tor Sunthorn , Wu Hai-Wei , Manalo Daria , Olveda Remigio , Acosta Luz , Kurtis Jonathan D.
Published: March 2009

Schistosomiasis remains a public health concern in developing countries, and rapid reinfection fostered by continued exposure to contaminated water sources necessitates a vaccine to augment current mass treatment-based control strategies. We report isotype-specific (immunoglobulin A [IgA], IgE, IgG1, IgG4, and IgG) antibody responses to soluble worm antigen preparation and the recombinant vaccine candidates rSj97, rSj67, and rSj22 from aSchistosoma japonicum-infected cohort in Leyte, the Philippines, where schistosomiasis is endemic. Sera were collected from infected individuals 1 month posttreatment with praziquantel, and antibody responses were measured using a bead-based multiplex platform. Reinfection was monitored by stool sampling every 3 months, and data up to 1 year were included in the analysis (n= 553). In repeated-measures models, individuals with detectible IgE responses to rSj97 had a 26% lower intensity of reinfection at 12 months posttreatment compared to nonresponders after adjusting for age, gender, village, exposure, pretreatment infection intensity, and clustering by household (P= 0.018). In contrast, IgG4 responses to rSj97 as well as rSj67 and rSj22 were associated with markedly increased reinfection intensity. When stratified by IgG4 and IgE responder status, individuals with IgE but not IgG4 responses to rSj97 (n= 16) had a 77% lower intensity of reinfection at 12 months compared to individuals with IgG4 responses but not IgE responses (n= 274), even after adjusting for potential confounders (P= 0.016). Together with our previously described protective cytokine responses, these data further support paramyosin as a leading vaccine candidate for human schistosomiasis japonica and underscore the importance of careful adjuvant selection to avoid the generation of blocking IgG4 antibody responses.
Langerhans Cell Deficiency ImpairsIxodes scapularisSuppression of Th1 Responses in Mice
Authors: Vesely Diana L. , Fish Durland , Shlomchik Mark J. , Kaplan Daniel H. , Bockenstedt Linda K.
Published: March 2009

Ixodes scapularisticks transmit a number of human pathogens, including the Lyme disease spirocheteBorrelia burgdorferi. I. scapularissuppresses host immunity in the skin to promote feeding and systemically skew T-helper (Th)-cell differentiation toward Th2 cells in secondary lymphoid organs. Although components of tick saliva are known to influence Th-cell polarization, the mechanism whereby tick feeding in the skin modulates regional and systemic Th-cell responses is unknown. In this study, the role of the epidermal Langerhans cell (LC) subset of skin dendritic cells in tick-mediated Th1/Th2-cell immunomodulation was assessed. Mice deficient in LCs (Langerin-DTA mice) exhibited enhanced lymph node (LN) concanavalin A (ConA)-induced Th1 responses after tick infestation in comparison to results for uninfested Langerin-DTA or wild-type (WT) mice, whereas effects on Th2-cell production of interleukin 4 were more variable. Nonetheless, the altered T-cell response did not impact tick feeding or refeeding. Gamma interferon production by ConA-stimulated LN cells of both WT and LC-deficient mice was enhanced by as much as fourfold afterB. burgdorferi-infected-tick feeding, indicating that immunomodulatory effects of tick saliva were not able to attenuate the Th1 immune responses induced by this pathogen. Taken together, these findings show a requirement for LCs in the tick-mediated attenuation of Th1 responses in regional lymph nodes but not in the spleens of mice and show that the presence of a pathogen can overcome the Th1-inhibitory effects of tick feeding on the host.
Anthrax Edema Toxin Induces Maturation of Dendritic Cells and Enhances Chemotaxis towards Macrophage Inflammatory Protein 3β
Authors: Maldonado-Arocho Francisco J. , Bradley Kenneth A.
Published: March 2009

Bacillus anthracissecretes two bipartite toxins, edema toxin (ET) and lethal toxin (LT), which impair immune responses and contribute directly to the pathology associated with the disease anthrax. Edema factor, the catalytic subunit of ET, is an adenylate cyclase that impairs host defenses by raising cellular cyclic AMP (cAMP) levels. Synthetic cAMP analogues and compounds that raise intracellular cAMP levels lead to phenotypic and functional changes in dendritic cells (DCs). Here, we demonstrate that ET induces a maturation state in human monocyte-derived DCs (MDDCs) similar to that induced by lipopolysaccharide (LPS). ET treatment results in downregulation of DC-SIGN, a marker of immature DCs, and upregulation of DC maturation markers CD83 and CD86. Maturation of DCs by ET is accompanied by an increased ability to migrate toward the lymph node-homing chemokine macrophage inflammatory protein 3β, like LPS-matured DCs. Interestingly, cotreating with LT differentially affects the ET-induced maturation of MDDCs while not inhibiting ET-induced migration. These findings reveal a mechanism by which ET impairs normal innate immune function and may explain the reported adjuvant effect of ET.
Rehabilitation after anterior cruciate ligament injury influences joint loading during walking but not hopping
Authors: Risberg M A , Moksnes H , Storevold A , Holm I , Snyder-Mackler L
Published: March 2009

Objective:

The purpose of this study was to identify changes in clinical outcome and lower extremity biomechanics during walking and hopping in ACL-injured subjects before and after a 20-session neuromuscular and strength training programme.

Study design:

Pre and post experimental design.

Setting:

Outpatient clinic, primary care.

Patients:

32 subjects with unilateral ACL injury, mean 60 (SD 35) days after injury, with a mean age of 26.2 (5.4) years.

Intervention:

The rehabilitation programme consisted of neuromuscular and strength exercises.

Main outcome measurements:

Outcome measurements assessed before and after a 20-session rehabilitation programme were: self-assessment questionnaires (KOS-ADL, IKDC2000, Global function), four single-leg hop tests, and isokinetic muscle strength tests. Lower extremity kinematics and kinetics were captured during the stance phase of gait and landing after a single leg hop, synchronised with three force plates.

Results:

These ACL-injured individuals significantly improved their clinical outcome after rehabilitation. Gait analysis disclosed a significantly improved knee extension moment after rehabilitation, but no change in hip or knee excursions. During landing after hop no change in knee excursion or knee moment was recorded.

Conclusion:

After rehabilitation the ACL-injured subjects showed a significantly improved clinical outcome, but lower extremity biomechanics were still significantly impaired during both walking and hopping. The rehabilitation programme influenced knee joint loading during walking, but not during hopping. Longer rehabilitation should be considered before ACL-injured individuals return to jumping activities.
Dilip Roy at Itsun Heavy Industries India Pvt. Ltd. (IHIIPL)
Authors: Parikh Margie
Published: March 2009

Dilip Roy is a country head at Itsun Heavy Industry (India) Pvt. Ltd. (IHIIPL) in Delhi, India. It is a wholly owned subsidiary of Itsun China, a leading private sector construction equipment company. Dilip graduated as a mechanical engineer with reputed National Science Talent Search Scholarship, started his career as a Graduate Trainee Engineer and became a Vice President in another company before he joined IHIIPL as a country head. Hu, the representative of Itsun China in India was exploring the Indian market and he ended up offering a job to Dilip after a series of interactions concerning the Indian Construction Equipment Industry. This was the first opportunity for Dilip to head an entire company. He knew the industry thoroughly and felt excited that finally his ambition was at the verge of fulfillment.

When Dilip joined, IHIPL had yet to be incorporated though some business activities had started. Dilip's time at IHIIPL is dotted with problem after problem. The key problems encountered were confusion about reporting relationships, unresponsive head office with its unilateral decisions, and unprofessional and incompetent colleagues. Dilip had taken steps to address most of the company's problems: developing local solutions, drawing on personal resources, and hiring new staff. The business was growing fast on the back of increasing demand. Subsequently, Dilip realized that he was not considered trustworthy by the head office and was not involved in major decisions. His initial perception about his job and IHIIPL changed. Even though he was later given the certificate of honor with an invitation to attend the award ceremony in China, he left the company. This case is useful for examining the issues of cross-cultural management and leadership.
CONVECTIVE HEAT TRANSFER CHARACTERISTICS OF AQUEOUS TiO2 NANOFLUID UNDER LAMINAR FLOW CONDITIONS
Authors: MURSHED S. M. SOHEL , LEONG KAI CHOONG , YANG CHUN , NGUYEN NAM-TRUNG
Published: March 2009

This paper reports an experimental investigation into force convective heat transfer of nanofluids flowing through a cylindrical minichannel under laminar flow and constant wall heat flux conditions. Sample nanofluids were prepared by dispersing different volumetric concentrations (0.2–0.8%) of nanoparticles in deionized water. The results showed that both the convective heat transfer coefficient and the Nusselt number of the nanofluid increase considerably with the nanoparticle volume fraction as well as the Reynolds number. Along with the enhanced thermal conductivity of nanofluids, the migration, interactions, and Brownian motion of nanoparticles and the resulting disturbance of the boundary layer are responsible for the observed enhancement of heat transfer coefficients of nanofluids.
NUCLEATION AND STRUCTURAL PROPERTIES OF NICKEL FILMS ELECTRODEPOSITED FROM, CHLORIDE AND SULFATE BATHS
Authors: AZIZI A. , SAHARI A. , SCHMERBER G. , DINIA A.
Published: March 2009

Nickel films electrodeposited from chloride and sulfate baths at pH 3.8 have been investigated. The influence of the plating baths on the electrochemical growth and the characteristics of nickel were studied by means of cyclic voltammetry, potentiostatic steps (chronoamperometry), atomic force microscopy (AFM) and X-ray diffraction (XRD) techniques. The electrocrystallization mechanism was analyzed using the Scharifker and Hills model. The nucleation mechanism was found to be progressive at -1.1 V versus SCE, while at elevated overpotentials (more negative than -1.2 V versus SCE) instantaneous nucleation behavior was obtained. AFM characterization of the deposits indicated that the baths composition influences greatly the morphology of the deposits. XRD analysis indicated polycrystalline growth of the Ni film with a preferred (111) orientation with the fcc structure for both baths. The Ni crystallite sizes are 19–31 nm for the sulfate bath and 14–33 nm for the chloride one.
TIMELINESThe information school phenomenon
Authors: Olson Gary M. , Grudin Jonathan
Published: March 2009

Gary Olson recently moved to UCI from the University of Michigan, where as faculty member and acting dean, he participated in the formation of its influential School of Information, described in this article. I have helped track down historical information on other influential iSchools. We may be witnessing the birth of a new star in the academic firmament---its growth, so far only a little slower than a supernova, may be tested by the economic collapse, but could accelerate with a recovery.---Jonathan Grudin
An evaluation of the TRIPS computer system
Authors: Gebhart Mark , Maher Bertrand A. , Coons Katherine E. , Diamond Jeff , Gratz Paul , Marino Mario , Ranganathan Nitya , Robatmili Behnam , Smith Aaron , Burrill James , Keckler Stephen W. , Burger Doug , McKinley Kathryn S.
Published: March 2009

The TRIPS system employs a new instruction set architecture (ISA) called Explicit Data Graph Execution (EDGE) that renegotiates the boundary between hardware and software to expose and exploit concurrency. EDGE ISAs use a block-atomic execution model in which blocks are composed of dataflow instructions. The goal of the TRIPS design is to mine concurrency for high performance while tolerating emerging technology scaling challenges, such as increasing wire delays and power consumption. This paper evaluates how well TRIPS meets this goal through a detailed ISA and performance analysis. We compare performance, using cycles counts, to commercial processors. On SPEC CPU2000, the Intel Core 2 outperforms compiled TRIPS code in most cases, although TRIPS matches a Pentium 4. On simple benchmarks, compiled TRIPS code outperforms the Core 2 by 10% and hand-optimized TRIPS code outperforms it by factor of 3. Compared to conventional ISAs, the block-atomic model provides a larger instruction window, increases concurrency at a cost of more instructions executed, and replaces register and memory accesses with more efficient direct instruction-to-instruction communication. Our analysis suggests ISA, microarchitecture, and compiler enhancements for addressing weaknesses in TRIPS and indicates that EDGE architectures have the potential to exploit greater concurrency in future technologies.
Recovery domains
Authors: Lenharth Andrew , Adve Vikram S. , King Samuel T.
Published: March 2009

We describe a strategy for enabling existing commodity operating systems to recover from unexpected run-time errors in nearly any part of the kernel, including core kernel components. Our approach is dynamic and request-oriented; it isolates the effects of a fault to the requests that caused the fault rather than to static kernel components. This approach is based on a notion of "recovery domains," an organizing principle to enable rollback of state affected by a request in a multithreaded system with minimal impact on other requests or threads. We have applied this approach on v2.4.22 and v2.6.27 of the Linux kernel and it required 132 lines of changed or new code: the other changes are all performed by a simple instrumentation pass of a compiler. Our experiments show that the approach is able to recover from otherwise fatal faults with minimal collateral impact during a recovery event.
Capo
Authors: Montesinos Pablo , Hicks Matthew , King Samuel T. , Torrellas Josep
Published: March 2009

While deterministic replay of parallel programs is a powerful technique, current proposals have shortcomings. Specifically, software-based replay systems have high overheads on multiprocessors, while hardware-based proposals focus only on basic hardware-level mechanisms, ignoring the overall replay system. To be practical, hardware-based replay systems need to support an environment with multiple parallel jobs running concurrently -- some being recorded, others being replayed and even others running without recording or replay. Moreover, they need to manage limited-size log buffers.

This paper addresses these shortcomings by introducing, for the first time, a set of abstractions and a software-hardware interface for practical hardware-assisted replay of multiprocessor systems. The approach, called
Capo
, introduces the novel abstraction of the
Replay Sphere
to separate the responsibilities of the hardware and software components of the replay system. In this paper, we also design and build
CapoOne
, a prototype of a deterministic multiprocessor replay system that implements Capo using Linux and simulated DeLorean hardware. Our evaluation of 4-processor executions shows that
CapoOne
largely records with the efficiency of hardware-based schemes and the flexibility of software-based schemes.
DMP
Authors: Devietti Joseph , Lucia Brandon , Ceze Luis , Oskin Mark
Published: March 2009

Current shared memory multicore and multiprocessor systems are nondeterministic. Each time these systems execute a multithreaded application, even if supplied with the same input, they can produce a different output. This frustrates debugging and limits the ability to properly test multithreaded code, becoming a major stumbling block to the much-needed widespread adoption of parallel programming.

In this paper we make the case for fully deterministic shared memory multiprocessing (DMP). The behavior of an arbitrary multithreaded program on a DMP system is only a function of its inputs. The core idea is to make inter-thread communication fully deterministic. Previous approaches to coping with nondeterminism in multithreaded programs have focused on replay, a technique useful only for debugging. In contrast, while DMP systems are directly useful for debugging by offering repeatability by default, we argue that parallel programs should execute deterministically in the field as well. This has the potential to make testing more assuring and increase the reliability of deployed multithreaded software. We propose a range of approaches to enforcing determinism and discuss their implementation trade-offs. We show that determinism can be provided with little performance cost using our architecture proposals on future hardware, and that software-only approaches can be utilized on existing systems.
Early experience with a commercial hardware transactional memory implementation
Authors: Dice Dave , Lev Yossi , Moir Mark , Nussbaum Daniel
Published: March 2009

We report on our experience with the hardware transactional memory (HTM) feature of two pre-production revisions of a new commercial multicore processor. Our experience includes a number of promising results using HTM to improve performance in a variety of contexts, and also identifies some ways in which the feature could be improved to make it even better. We give detailed accounts of our experiences, sharing techniques we used to achieve the results we have, as well as describing challenges we faced in doing so.
Mixed-mode multicore reliability
Authors: Wells Philip M. , Chakraborty Koushik , Sohi Gurindar S.
Published: March 2009

Future processors are expected to observe increasing rates of hardware faults. Using Dual-Modular Redundancy (DMR), two cores of a multicore can be loosely coupled to redundantly execute a single software thread, providing very high coverage from many difference sources of faults. This reliability, however, comes at a high price in terms of per-thread IPC and overall system throughput.

We make the observation that a user may want to run both applications requiring high reliability, such as financial software, and more fault tolerant applications requiring high performance, such as media or web software, on the same machine at the same time. Yet a traditional DMR system must fully operate in redundant mode whenever any application requires high reliability.

This paper proposes a Mixed-Mode Multicore (MMM), which enables most applications, including the system software, to run with high reliability in DMR mode, while applications that need high performance can avoid the penalty of DMR. Though conceptually simple, two key challenges arise: 1) care must be taken to protect reliable applications from any faults occurring to applications running in high performance mode, and 2) the desire to execute additional independent software threads for a performance application complicates the scheduling of computation to cores. After solving these issues, an MMM is shown to improve overall system performance, compared to a traditional DMR system, by approximately 2X when one reliable and one performance application are concurrently executing.
ISOLATOR
Authors: Rajamani Sriram , Ramalingam G. , Ranganath Venkatesh Prasad , Vaswani Kapil
Published: March 2009

In this paper, we focus on concurrent programs that use locks to achieve isolation of data accessed by critical sections of code. We present ISOLATOR, an algorithm that guarantees isolation for well-behaved threads of a program that obey a locking discipline even in the presence of ill-behaved threads that disobey the locking discipline. ISOLATOR uses code instrumentation, data replication, and virtual memory protection to detect isolation violations and delays ill-behaved threads to ensure isolation. Our instrumentation scheme requires access only to the code of well-behaved threads. We have evaluated ISOLATOR on several benchmark programs and found that ISOLATOR can ensure isolation with reasonable runtime overheads. In addition, we present three general desiderata - safety, isolation, and permissiveness - for any scheme that attempts to ensure isolation, and formally prove that ISOLATOR satisfies all of these desiderata.
Efficient online validation with delta execution
Authors: Tucek Joseph , Xiong Weiwei , Zhou Yuanyuan
Published: March 2009

Software systems are constantly changing. Patches to fix bugs and patches to add features are all too common. Every change risks breaking a previously working system. Hence administrators loathe change, and are willing to delay even critical security patches until after fully validating their correctness. Compared to off-line validation, on-line validation has clear advantages since it tests against real life workloads. Yet unfortunately it imposes restrictive overheads as it requires running the old and new versions side-by-side. Moreover, due to spurious differences (e.g. event timing, random number generation, and thread interleavings), it is difficult to compare the two for validation.

To allow more effective on-line patch validation, we propose a new mechanism, called delta execution, that is based on the observation that most patches are small. Delta execution merges the two side-by-side executions for most of the time and splits only when necessary, such as when they access different data or execute different code. This allows us to perform on-line validation not only with lower overhead but also with greatly reduced spurious differences, allowing us to effectively validate changes.

We first validate the feasibility of our idea by studying the characteristics of 240 patches from 4 server programs; our examination shows that 77% of the changes should not be expected to cause large changes and are thereby feasible for Delta execution. We then implemented Delta execution using dynamic instrumentation. Using real world patches from 7 server applications and 3 other programs, we compared our implementation of Delta execution against a traditional side-by-side on-line validation. Delta execution outperformed traditional validation by up to 128%; further, for 3 of the changes, spurious differences caused the traditional validation to fail completely while Delta execution succeeded. This demonstrates that Delta execution can allow administrators to use on-line validation to confidently ensure the correctness of the changes they apply.
Dynamic prediction of collection yield for managed runtimes
Authors: Wegiel Michal , Krintz Chandra
Published: March 2009

The growth in complexity of modern systems makes it increasingly difficult to extract high-performance. The software stacks for such systems typically consist of multiple layers and include managed runtime environments (MREs). In this paper, we investigate techniques to improve cooperation between these layers and the hardware to increase the efficacy of automatic memory management in MREs.

General-purpose MREs commonly implement parallel and/or concurrent garbage collection and employ compaction to eliminate heap fragmentation. Moreover, most systems trigger collection based on the amount of heap a program uses. Our analysis shows that in many cases this strategy leads to ineffective collections that are unable to reclaim sufficient space to justify the incurred cost. To avoid such collections, we exploit the observation that dead objects tend to cluster together and form large, never-referenced, regions in the address space that correlate well with virtual pages that have not recently been referenced by the application. We leverage this correlation to design a new, simple and light-weight, yield predictor that estimates the amount of reclaimable space in the heap using hardware page reference bits. Our predictor allows MREs to avoid low-yield collections and thereby improve resource management.

We integrate this predictor into three state-of-the-art parallel compactors, implemented in the HotSpot JVM, that represent distinct canonical heap layouts. Our empirical evaluation, based on standard Java benchmarks and open-source applications, indicates that inexpensive and accurate yield prediction can improve performance significantly.
Effects of exercise and low-fat diet on adipose tissue inflammation and metabolic complications in obese mice
Authors: Vieira Victoria J. , Valentine Rudy J. , Wilund Kenneth R. , Antao Nirav , Baynard Tracy , Woods Jeffrey A.
Published: March 2009

Adipose tissue inflammation causes metabolic disturbances, including insulin resistance and hepatic steatosis. Exercise training (EX) may decrease adipose tissue inflammation, thereby ameliorating such disturbances, even in the absence of fat loss. The purpose of this study was to 1) compare the effects of low-fat diet (LFD), EX, and their combination on inflammation, insulin resistance, and hepatic steatosis in high-fat diet-induced obese mice and 2) determine the effect of intervention duration (i.e., 6 vs. 12 wk). C57BL/6 mice ( n = 109) fed a 45% fat diet (HFD) for 6 wk were randomly assigned to an EX (treadmill: 5 days/wk, 6 or 12 wk, 40 min/day, 65–70% V̇o2max) or sedentary (SED) group. Mice remained on HFD or were placed on a 10% fat diet (LFD) for 6 or 12 wk. Following interventions, fat pads were weighed and expressed relative to body weight; hepatic steatosis was assessed by total liver triglyceride and insulin resistance by HOMA-IR and glucose AUC. RT-PCR was used to determine adipose gene expression of MCP-1, F4/80, TNF-α, and leptin. By 12 wk, MCP-1, F4/80, and TNF-α mRNA were reduced by EX and LFD. Exercise ( P = 0.02), adiposity ( P = 0.03), and adipose F4/80 ( P = 0.02) predicted reductions in HOMA-IR ( r2 = 0.75, P < 0.001); only adiposity ( P = 0.04) predicted improvements in hepatic steatosis ( r2 = 0.51, P < 0.001). Compared with LFD, EX attenuated increases in adiposity, hepatic steatosis, and adipose MCP-1 expression from 6 to 12 wk. There are unique metabolic consequences of a sedentary lifestyle and HFD that are most evident long term, highlighting the importance of both EX and LFD in preventing obesity-related metabolic disturbances.
Ab initiostructure determination of SrBi2OB4O9by powder X-ray/neutron diffraction and NMR spectroscopy
Authors: Barbier J. , Davis L. J. M. , Goward G. R. , Cranswick L. M. D.
Published: March 2009

SrBi2OB4O9is a novel centrosymmetric borate oxide forming in the SrO–Bi2O3–B2O3system. Its crystal structure has been determinedab initiofrom high-resolution X-ray and neutron powder diffraction data with the help of11B MAS-NMR data. SrBi2OB4O9crystallizes with a triclinic unit-cell witha=6.8657(1) Å,b=9.7976(1) Å,c=6.8148(1) Å,α=109.1270(8)°,β=101.8971(8)°,γ=96.1445(8)°,V=416.17(1) Å3,Z=2, space group P-1. Its structure consists of Bi2O4+layers alternating along thebaxis with SrB4O94−layers containing isolated B4O96−(〈2Δ〉Δ) tetraborate anions.
Automatic determination of phase transition points in in situ X-ray powder diffraction experiments
Authors: Rajiv P. , Dinnebier R. E. , Jansen M.
Published: March 2009

Powder diffraction experiments performed as a function of external variables like, e.g., temperature, pressure, or time open possibilities to gain additional information about the physical and chemical properties of the system under study. Sensible extraction of such information directly from in situ experiments requires the treatment of the dataset with methods like sequential and/or parametric refinements. We are progressing towards the development of the parametric refinement method, which performs simultaneous phase refinements of in situ powder patterns by imposing several rational physical models of the evolving parameters on the calculated powder diffraction profiles. One of the fundamental prerequisites for this method is that the powder patterns in the in situ dataset be grouped to their relevant phases. In this paper, we present an analytical method which uses the Pearson’s correlations coefficients of the powder patterns to automatically determine the phase transition points of the in situ powder dataset. The phase transition points determined are used to group the powder patterns belonging to identical phases and to prepare the patterns for automated sequential phase refinements. The proposed algorithm is implemented as an automated module in the multi powder diffraction pattern, data reduction software Powder 3D.
XRD diffraction data and Rietveld refinement of Na8[Si6Al6O24]Cl2
Authors: Siqueira Guilherme Oliveira , Gravina Érica Gonçalves , Resende Jackson Antônio Lamounier Camargos , Fernandes Nelson Gonçalves
Published: March 2009

A natural sodalite from the geological site Alkaline Complex of Floresta Azul, Bahia, Brazil, has been characterized by electron microprobe, infrared spectroscopy, and powder high-resolution X-ray diffraction techniques. The mineral is an aluminosilicate framework, formed by cages called sodalite unity. Although the sample is natural, the chemical analysis reveals that it is indeed the end member sodalitesensu strictu, Na8[Si6Al6O24]Cl2. Infrared spectroscopy shows Si, Al tetrahedral-oxygen stretching nonsymmetric mode, stretching symmetric mode, and bending modes. Indexing of the experimental X-ray diffraction pattern led to cubic space groupP-43n, and unit-cell parameters:a=8.8767(7) Å,Dx=2.301 gcm−3, andV=699.46(1) Å3. X-ray diffraction data are reported. Rietveld refinement was also performed, and the confidence factors are Rp=0.079, Rwp=0.118, andχ2=2.19. The structure of the minerals of sodalite group holds four different tetrahedra: AlO4, ClNa4, Na(ClO3), and SiO4, with Al, Cl, Na, and Si located at the center of each tetrahedron.
Bank Valuation and Its Connections with the Subprime Mortgage Crisis and Basel II Capital Accord
Authors: Fouche C. H. , Mukuddem-Petersen J. , Petersen M. A. , Senosi M. C.
Published: March 2009

The ongoing subprime mortgage crisis (SMC) and implementation of Basel II
Capital Accord regulation have resulted in issues related to bank
valuation and profitability becoming more topical. Profit is a major
indicator of financial crises for households, companies, and financial institutions. An SMC‐related example of this is the U.S. bank,
Wachovia Corp., which reported major losses in the first quarter of 2007
and eventually was bought by Citigroup in September 2008. A first
objective of this paper is to value a bank subject to Basel II based
on premiums for market, credit, and operational risk. In this case, we
investigate the discrete‐time dynamics of banking assets, capital, and
profit when loan losses and macroeconomic conditions are explicitly
considered. These models enable us to formulate an optimal bank
valuation problem subject to cash flow, loan demand, financing, and
balance sheet constraints. The main achievement of this paper is bank
value maximization via optimal choices of loan rate and supply which
leads to maximal deposits, provisions for deposit withdrawals, and bank
profitability. The aforementioned loan rates and capital provide
connections with the SMC. Finally, OECD data confirms that loan loss
provisioning and profitability are strongly correlated with the
business cycle.
Cardiopulmonary Manifestations of Hepatosplenic Schistosomiasis
Authors: Lapa Monica , Dias Bruno , Jardim Carlos , Fernandes Caio J.C. , Dourado Paulo M.M. , Figueiredo Magda , Farias Alberto , Tsutsui Jeane , Terra-Filho Mario , Humbert Marc , Souza Rogerio
Published: March 2009

Background —

Schistosomiasis is a highly prevalent disease with >200 million infected people. Pulmonary hypertension is one of the pulmonary manifestations in this disease, particularly in its hepatosplenic presentation. The aim of this study was to determine the prevalence of pulmonary hypertension in schistosomiasis patients with the hepatosplenic form of the disease.

Methods and Results —

All patients with hepatosplenic schistosomiasis followed up at the gastroenterology department of our university hospital underwent echocardiographic evaluation to search for pulmonary hypertension. Patients presenting with systolic pulmonary artery pressure >40 mm Hg were further evaluated through right heart catheterization. Our study showed an 18.5% prevalence of patients with elevated systolic pulmonary artery pressure at echocardiography. Invasive hemodynamics confirmed the presence of pulmonary hypertension in 7.7% (95% confidence interval, 3.3 to 16.7) of patients, with a prevalence of precapillary (arterial) pulmonary hypertension of 4.6% (95% confidence interval, 1.5 to 12.7).

Conclusions —

Our study reinforces the role of echocardiography as a screening tool in the investigation of pulmonary hypertension, together with the need for invasive monitoring for a proper diagnosis. We conclude that hepatosplenic schistosomiasis may account for one of the most prevalent forms of pulmonary hypertension worldwide, justifying the development of further studies to evaluate the effect of specific pulmonary hypertension treatment in this particular form of the disease.
Early-Life Sodium Exposure Unmasks Susceptibility to Stroke in Hyperlipidemic, Hypertensive Heterozygous Tg25 Rats Transgenic for Human Cholesteryl Ester Transfer Protein
Authors: Decano Julius L. , Viereck Jason C. , McKee Ann C. , Hamilton James A. , Ruiz-Opazo Nelson , Herrera Victoria L.M.
Published: March 2009

Background—

Early-life risk factor exposure increases aortic atherosclerosis and blood pressure in humans and animal models; however, limited insight has been gained as to end-organ complications.

Methods and Results—

We investigated the effects of early-life Na exposure (0.23% versus 0.4% NaCl regular rat chow) on vascular disease outcomes using the inbred, transgenic [hCETP]
25
Dahl salt-sensitive hypertensive rat model of male-predominant coronary atherosclerosis, Tg25. Rather than the expected increase in coronary heart disease, fetal 0.4% Na exposure (≤2 g of Na per 2-kcal/d diet) induced adult-onset stroke in both sexes (ANOVA
P
<0.0001), with earlier stroke onset in Tg25 females. Analysis of later onset of 0.4% Na exposure resulted in decreased stroke risk and later stroke onset despite longer 0.4% Na exposure durations, which indicates increasing risk with earlier onset of 0.4% Na exposure. Histological analysis of stroke-positive rat brains revealed cerebral cortical hemorrhagic infarctions, microhemorrhages, neuronal ischemia, and microvascular injury. Ex vivo MRI of stroke-positive rat brains detected cerebral hemorrhages, microhemorrhages, and ischemia with middle cerebral artery distribution and cerebellar noninvolvement. Ultrasound microimaging detected carotid artery disease. Prestroke analysis detected neuronal ischemia and decreased mass of isolated cerebral but not cerebellar microvessels.

Conclusions—

Early-life Na exposure exacerbated hypertension and unmasked stroke susceptibility, with greater female vulnerability in hypertensive, hyperlipidemic Tg25 rats. The reproducible modeling in stroke-prone Tg25 rats of carotid artery disease, cerebral hemorrhagic infarctions, neuronal ischemia, microhemorrhages, and microvascular alterations suggests a pathogenic spectrum with causal interrelationships. This “mixed-stroke” spectrum could represent paradigms of ischemic-hemorrhagic transformation and/or a microangiopathic basis for the association of ischemic lesions, microhemorrhages, and strokes in humans. Together, the data reveal early-life Na exposure to be a significant modifier of hypertension and stroke disease course and hence a potentially modifiable prevention target that deserves systematic study.
Influence of Adiposity and Physical Activity on Arterial Stiffness in Healthy Children
Authors: Sakuragi Satoru , Abhayaratna Katrina , Gravenmaker Karen J. , O'Reilly Christine , Srikusalanukul Wichat , Budge Marc M. , Telford Richard D. , Abhayaratna Walter P.
Published: March 2009

Childhood obesity is increasingly prevalent in the community and is related to adverse cardiovascular outcomes during adulthood. In this study of healthy children, we evaluated the influence of adiposity and physical activity on carotid-femoral pulse wave velocity (PWV), an index of arterial stiffness and a marker of cardiovascular risk in adults. In 573 community-based children (mean age: 10.1±0.3 years; 51% boys), we measured body mass index and waist circumference. Percentage body fat was quantitated by dual-energy x-ray absorptiometry. Cardiorespiratory fitness (CRF) and physical activity levels were assessed using a 20-m shuttle run and 7-day pedometer count, respectively. PWV was estimated by applanation tonometry. In univariate analysis, PWV was positively correlated with body mass index (
r
=0.34), waist circumference (
r
=0.32), and percentage body fat (
r
=0.32;
P
<0.001 for all) and negatively correlated with CRF (
r
=−0.23;
P
<0.001) and pedometer count (
r
=−0.08;
P
=0.046). In separate multivariable linear regression models, body mass index, waist circumference, and percentage of body fat were independently and positively associated with PWV (
P
<0.01 for all) after adjusting for age, sex, systolic blood pressure, mean arterial pressure, heart rate, and CRF (
P
<0.01 for all). The influence of CRF on PWV was attenuated after adjusting for adiposity. In conclusion, increased body mass and adiposity and decreased CRF are associated with arterial stiffening in healthy prepubescent children.
Acute Effects of Ambient Particulate Matter on Blood Pressure
Authors: Dvonch J. Timothy , Kannan Srimathi , Schulz Amy J. , Keeler Gerald J. , Mentz Graciela , House James , Benjamin Alison , Max Paul , Bard Robert L. , Brook Robert D.
Published: March 2009

Recent studies have suggested a link between exposure to ambient particulate matter <2.5 μm in diameter (PM
2.5
) and adverse cardiovascular outcomes. The objective of this study was to examine the effects of differing community-level exposure to PM
2.5
on daily measures of blood pressure (BP) among an adult population. During the period May 2002 through April 2003, BP was examined at 2 time points for 347 adults residing in 3 distinct communities of Detroit, Michigan. Exposure to PM
2.5
was assessed in each community during this period, along with multivariate associations between PM
2.5
and BP. In models combining all 3 of the communities, PM
2.5
was significantly associated with systolic blood pressure; a 10-μg/m
3
increase in daily PM
2.5
was associated with a 3.2-mm Hg increase in systolic blood pressure (
P
=0.05). However, in models that added a location interaction, larger effects were observed for systolic blood pressure within the community with highest PM
2.5
levels; a 10-μg/m
3
increase in daily PM
2.5
was associated with a 8.6-mm Hg increase in systolic blood pressure (
P
=0.01). We also found young age (<55 years) and not taking BP medications to be significant predictors of increased BP effects. Among those taking BP medications, the PM
2.5
effect on BP appeared to be mitigated, partially explaining the age effect, because those participants <55 years of age were less likely to take BP medications. Short-term increases in exposure to ambient PM
2.5
are associated with acute increases in BP in adults, especially within communities with elevated levels of exposure.
Determining What Works for Girls in the Juvenile Justice System
Authors: Zahn Margaret A. , Day Jacob C. , Mihalic Sharon F. , Tichavsky Lisa
Published: March 2009

Despite increasing attention on gender-specific programming for girls involved in the juvenile justice system, not much is known about the effectiveness of gender-specific programs. The authors review the evidence base for the effectiveness of programs for girls in custody or under supervision by examining the evaluation evidence for nine gender-specific programs (which exclusively target girls) and six gender-non-specific programs (which target both girls and boys). Through this process, the authors summarize the evidence of effectiveness available to researchers and practitioners, identify barriers to determining what programs work for adjudicated girls, and make recommendations for building a solid evidence base on what works for adjudicated girls.