bluuebunny/crossref_metadata_2025 huggingface dataset:
Communicating memory transactions
Authors: Lesani Mohsen , Palsberg Jens
Published: October 2011

Many concurrent programming models enable both transactional memory and message passing. For such models, researchers have built increasingly efficient implementations and defined reasonable correctness criteria, while it remains an open problem to obtain the best of both worlds. We present a programming model that is the first to have opaque transactions, safe asynchronous message passing, and an efficient implementation. Our semantics uses tentative message passing and keeps track of dependencies to enable undo of message passing in case a transaction aborts. We can program communication idioms such as barrier and rendezvous that do not deadlock when used in an atomic block. Our experiments show that our model adds little overhead to pure transactions, and that it is significantly more efficient than Transactional Events. We use a novel definition of safe message passing that may be of independent interest.
Enhanced speculative parallelization via incremental recovery
Authors: Tian Chen , Lin Changhui , Feng Min , Gupta Rajiv
Published: October 2011

The widespread availability of multicore systems has led to an increased interest in speculative parallelization of sequential programs using software-based thread level speculation. Many of the proposed techniques are implemented via state separation where non-speculative computation state is maintained separately from the speculative state of threads performing speculative computations. If speculation is successful, the results from speculative state are committed to non-speculative state. However, upon misspeculation, discard-all scheme is employed in which speculatively computed results of a thread are discarded and the computation is performed again. While this scheme is simple to implement, one disadvantage of discard-all is its inability to tolerate high misspeculation rates due to its high runtime overhead. Thus, it is not suitable for use in applications where misspeculation rates are input dependent and therefore may reach high levels.

In this paper we develop an approach for incremental recovery in which, instead of discarding all of the results and reexecuting the speculative computation in its entirety, the computation is restarted from the earliest point at which a misspeculation causing value is read. This approach has two advantages. First, the cost of recovery is reduced as only part of the computation is reexecuted. Second, since recovery takes less time, the likelihood of future misspeculations is reduced. We design and implement a strategy for implementing incremental recovery that allows results of partial computations to be efficiently saved and reused. For a set of programs where misspeculation rate is input dependent, our experiments show that with inputs that result in misspeculation rates of around 40% and 80%, applying incremental recovery technique results in 1.2x-3.3x and 2.0x-6.6x speedups respectively over the discard-all recovery scheme. Furthermore, misspeculations observed during discard-all scheme are reduced when incremental recovery is employed -- reductions range from 10% to 85%.
Wait-free queues with multiple enqueuers and dequeuers
Authors: Kogan Alex , Petrank Erez
Published: October 2011

The queue data structure is fundamental and ubiquitous. Lock-free versions of the queue are well known. However, an important open question is whether practical wait-free queues exist. Until now, only versions with limited concurrency were proposed. In this paper we provide a design for a practical wait-free queue. Our construction is based on the highly efficient lock-free queue of Michael and Scott. To achieve wait-freedom, we employ a priority-based helping scheme in which faster threads help the slower peers to complete their pending operations. We have implemented our scheme on multicore machines and present performance measurements comparing our implementation with that of Michael and Scott in several system configurations.
Auto-tuning of fast fourier transform on graphics processors
Authors: Dotsenko Yuri , Baghsorkhi Sara S. , Lloyd Brandon , Govindaraju Naga K.
Published: October 2011

We present an auto-tuning framework for FFTs on graphics processors (GPUs). Due to complex design of the memory and compute subsystems on GPUs, the performance of FFT kernels over the range of possible input parameters can vary widely. We generate several variants for each component of the FFT kernel that, for different cases, are likely to perform well. Our auto-tuner composes variants to generate kernels and selects the best ones. We present heuristics to prune the search space and profile only a small fraction of all possible kernels. We compose optimized kernels to improve the performance of larger FFT computations. We implement the system using the NVIDIA CUDA API and compare its performance to the state-of-the-art FFT libraries. On a range of NVIDIA GPUs and input sizes, our auto-tuned FFTs outperform the NVIDIA CUFFT 3.0 library by up to 38x and deliver up to 3x higher performance compared to a manually-tuned FFT.
Weak atomicity under the x86 memory consistency model
Authors: Roy Amitabha , Hand Steven , Harris Tim
Published: October 2011

We consider the problem of building a weakly atomic Software Transactional Memory (STM), that provides Single (Global) Lock Atomicity (SLA) while adhering to the x86 memory consistency model (x86-MM).
Kremlin
Authors: Jeon Donghwan , Garcia Saturnino , Louie Chris , Kota Venkata Sravanthi , Taylor Michael Bedford
Published: October 2011

This paper overviews Kremlin, a software profiling tool designed to assist the parallelization of serial programs. Kremlin accepts a serial source code, profiles it, and provides a list of regions that should be considered in parallelization. Unlike a typical profiler, Kremlin profiles not only work but also parallelism, which is accomplished via a novel technique called hierarchical critical path analysis. Our evaluation demonstrates that Kremlin is highly effective, resulting in a parallelized program whose performance sometimes outperforms, and is mostly comparable to, manual parallelization. At the same time, Kremlin would require that the user parallelize significantly fewer regions of the program. Finally, a user study suggests Kremlin is effective in improving the productivity of programmers.
Algorithm-based recovery for HPL
Authors: Davies Teresa , Chen Zizhong , Karlsson Christer , Liu Hui
Published: October 2011

When more processors are used for a calculation, the probability that one will fail during the calculation increases. Fault tolerance is a technique for allowing a calculation to survive a failure, and includes recovering lost data. A common method of recovery is diskless checkpointing. However, it has high overhead when a large amount of data is involved, as is the case with matrix operations. A checksum-based method allows fault tolerance of matrix operations with lower overhead. This technique is applicable to the LU decomposition in the benchmark HPL.
Understanding the influence of blog on the development of social capital
Authors: Vaezi Reza , Torkzadeh Gholamreza , Chang Jerry Cha-Jan
Published: October 2011

The rapid use and application of blogs in diverse areas such as education, marketing, journalism, and human resource management in recent years underlines the need for a better understanding of the impact of this new technology on social capital. Social capital reflects the norm of reciprocity and the level of trust among individuals who connect, interact, and benefit from one another. Blog is expected to influence the extent and the scope of this interaction by providing new means of networking among people. This paper examines the relationship between blog use and social capital and reports on the results of an exploratory study that examines this relationship using survey data from 326 blog users. Results suggest a significant and positive impact of blog use on social capital and its components: social connections, reciprocity, and trust. Implications of these findings for research and practice are discussed.
A new way about using statistical analysis of worst-case execution times
Authors: Lu Yue , Nolte Thomas , Bate Iain , Cucu-Grosjean Liliana
Published: October 2011

In this paper, we revisit the problem of using Extreme Value Theory (EVT) in the Worst-Case Execution Time (WCET) analysis of the programs running on a single processor. Our proposed statistical WCET analysis method consists of a novel sampling mechanism tackling with some problems that hindered the application of using EVT in the context, and a statistical inference about computation of a WCET estimate of the target program. To be specific, the presented sampling mechanism takes analysis samples from the target program based around end-to-end measurements. Next, the statistical inference using EVT together with other statistical techniques, analyzes such timing traces which contain the execution time data of the program, to compute a WCET estimate with a certain predictable probability of being exceeded.
Personalised video retrieval
Authors: hopfgartner Frank
Published: October 2011

A challenging problem in the user profiling domain is to create profiles of users of retrieval systems. This problem even exacerbates in the multimedia domain. Due to the Semantic Gap, the difference between lowlevel data representation of videos and the higher concepts users associate with videos, it is not trivial to understand the content of multimedia documents and to find other documents that the users might be interested in. A promising approach to ease this problem is to set multimedia documents into their semantic contexts. The semantic context can lead to a better understanding of the personal interests. Knowing the context of a video is useful for recommending users videos that match their information need. By exploiting these contexts, videos can also be linked to other, contextually related videos. From a user profiling point of view, these links can be of high value to recommend semantically related videos, hence creating a semantic-based user profile. This thesis introduces a semantic user profiling approach for news video retrieval, which exploits a generic ontology to put news stories into its context.
Formation and Device Application of Ge Nanowire Heterostructures via Rapid Thermal Annealing
Authors: Tang Jianshi , Wang Chiu-Yen , Xiu Faxian , Zhou Yi , Chen Lih-Juann , Wang Kang L.
Published: October 2011

We reviewed the formation of Ge nanowire heterostructure and its field-effect characteristics by a controlled reaction between a single-crystalline Ge nanowire and Ni contact pads using a facile rapid thermal annealing process. Scanning electron microscopy and transmission electron microscopy demonstrated a wide temperature range of 400~500°C to convert the Ge nanowire to a single-crystalline Ni2Ge/Ge/Ni2Ge nanowire heterostructure with atomically sharp interfaces. More importantly, we studied the effect of oxide confinement during the formation of nickel germanides in a Ge nanowire. In contrast to the formation of Ni2Ge/Ge/Ni2Ge nanowire heterostructures, a segment of high-quality epitaxial NiGe was formed between Ni2Ge with the confinement of Al2O3during annealing. A twisted epitaxial growth mode was observed in both two Ge nanowire heterostructures to accommodate the large lattice mismatch in the NixGe/Ge interface. Moreover, we have demonstrated field-effect transistors using the nickel germanide regions as source/drain contacts to the Ge nanowire channel. Our Ge nanowire transistors have shown a high-performancep-type behavior with a high on/off ratio of 105and a field-effect hole mobility of 210 cm2/Vs, which showed a significant improvement compared with that from unreacted Ge nanowire transistors.
Evo-Devo and Brain Scaling: Candidate Developmental Mechanisms for Variation and Constancy in Vertebrate Brain Evolution
Authors: Charvet Christine J. , Striedter Georg F. , Finlay Barbara L.
Published: October 2011

Biologists have long been interested in both the regularities and the deviations in the relationship between brain, development, ecology, and behavior between taxa. We first examine some basic information about the observed ranges of fundamental changes in developmental parameters (i.e. neurogenesis timing, cell cycle rates, and gene expression patterns) between taxa. Next, we review what is known about the relative importance of different kinds of developmental mechanisms in producing brain change, focusing on mechanisms of segmentation, local and general features of neurogenesis, and cell cycle kinetics. We suggest that a limited set of developmental alterations of the vertebrate nervous system typically occur and that each kind of developmental change may entail unique anatomical, functional, and behavioral consequences for the organism. Thus, neuroecologists who posit a direct mapping of brain size to behavior should consider that not any change in brain anatomy is possible.
Severe Neonatal Hyperbilirubinemia and Kernicterus: Are These Still Problems in the Third Millennium?
Authors: Kaplan Michael , Bromiker Ruben , Hammerman Cathy
Published: October 2011

Despite efforts to eliminate permanent and irreversible brain damage due to bilirubin encephalopathy and kernicterus, these conditions continue to accompany us into the third millennium. This phenomenon occurs not only in developing countries with emerging medical systems, but in Westernized countries as well. Comprehensive guidelines to detect newborns with jaundice and treat those in whom hyperbilirubinemia has already developed have been formulated in several countries, but have not been successful in completely eliminating the problem. In this appraisal of the situation we review selected aspects of bilirubin encephalopathy and/or kernicterus. We highlight recent reports of severe hyperbilirubinemia and kernicterus, discuss some of the factors responsible for the continuing appearance of these conditions, and briefly review what can be done to decrease bilirubin-related morbidity and mortality to the minimum.
Neurological Complications of Acute Intermittent Porphyria
Authors: Kuo Hung-Chou , Huang Chin-Chang , Chu Chun-Che , Lee Ming-Jen , Chuang Wen-Li , Wu Chi-Lin , Wu Tony , Ning Hsiao-Chen , Liu Chih-Yang
Published: October 2011

Background: Acute intermittent porphyria (AIP) is an inherited disorder of heme biosynthesis, the clinical manifestations of which are incompletely understood. In this report, we describe 12 cases of AIP, focusing on the neurological manifestations. Methods: Twelve patients were diagnosed with AIP on the basis of characteristic clinical findings, erythrocyte porphobilinogen deaminase (PBGD) activity, and molecular genetics. Central and peripheral nervous system manifestations were noted, and electrophysiological and radiological studies performed. Potential precipitating factors were recorded. Results: Eleven PBGD gene mutations were identified in 12 patients. Nine patients experienced neurological symptoms involving the central nervous system (consciousness disturbance, n = 8; convulsion/seizure, n = 4; behavior change, n = 1), while 7 patients experienced peripheral neuropathies (motor paresis, n = 7; impairment of bulbar or respiratory function, n = 4). The electrophysiological and electroencephalographic findings were consistent with the neurological symptoms of AIP. Urinary PBG and δ-aminolevulinic acid levels were elevated in all patients. PBGD enzyme activity levels were below normal in all patients. Eight patients had documented exposure to porphyrogenic agents. Conclusions: Our detailed description of a relatively large number of cases of AIP may help clinicians to recognize this often difficult-to-diagnose disorder.
Coronary Microcirculation Remodeling in Patients with Idiopathic Dilated Cardiomyopathy
Authors: Laguens Rubén , Alvarez Paulino , Vigliano Carlos , Cabeza Meckert Patricia , Favaloro Liliana , Diez Mirta , Favaloro Roberto
Published: October 2011

Background: In patients with idiopathic dilated cardiomyopathy (IDCM), the myocardial blood flow is markedly depressed. The presence of alterations in the number and length of the coronary microcirculation has not been explored. Methods: In explanted hearts of 6 patients with IDCM and in 6 normal control hearts, the arteriolar length density and capillary numerical density were determined in sections stained with orcein (vessels 50–200 µm in diameter), for smooth muscle actin (vessels 6–50 µm in diameter) and CD34 (capillaries). Results: No difference with normal hearts was observed in capillary numerical density and in length density of vessels above 50 µm in diameter. In IDCM, more than 50% of arterioles below 50 µm in diameter displayed an incomplete smooth muscle wall, and length density, especially for arterioles between 6 and 20 µm in diameter, was significantly lower (42.84 ± 8.51 mm/mm3) than in controls (75.34 ± 3.05 mm/mm3, p = 0.001). Conclusions: In IDCM, arterioles below 50 µm in diameter display an incomplete smooth muscle wall and a significant decrease in length density. These observations provide an anatomical basis for a decreased coronary flow reserve in IDCM.
The ADMA-Metformin Hypothesis: Linking the Cardiovascular Consequences of the Metabolic Syndrome and Type 2 Diabetes
Authors: Bestermann, Jr. William H.
Published: October 2011

Metformin and asymmetric dimethylarginine (ADMA) are structural analogs. They have opposite effects at multiple points on complex signaling pathways that coordinate energy, molecular synthesis, growth, and metabolism with nutrient intake. Excess saturated fats and glucose may initiate the methylation of arginine residues in proteins involved in the transcription of genes mediating inflammation, cell proliferation, apoptosis, and oncogenesis. Free ADMA may appear in the circulation after proteolysis of these proteins when the work of transcription is complete and ADMA subsequently functions as a signaling molecule. In children, ADMA levels are not significantly related to the usual metabolic syndrome risk factors but instead there is a significant association between ADMA and alkaline phosphatase – a marker of normal growth. There is only one direct study that shows that ADMA negates the metabolic effects of metformin. There are no investigations that demonstrate that metformin blocks the effect of ADMA and so this review must be considered hypothesis generating. The potential implications of the metformin-ADMA relationship merit further investigation.
Effects of Intra-Arterial and Intravenous Iso-Osmolar Contrast Medium (Iodixanol) on the Risk of Contrast-Induced Acute Kidney Injury: A Meta-Analysis
Authors: McCullough Peter A. , Brown Jeremiah R.
Published: October 2011

Background: The iso-osmolar contrast agent iodixanol may be associated with a lower incidence of contrast-induced acute kidney injury (CI-AKI) than low-osmolar contrast media (LOCM), but previous meta-analyses have yielded mixed results. Objectives: To compare the incidence of CI-AKI between iodixanol and LOCM. Methods: Studies were identified from literature searches to December 2009, clinicaltrials.gov, and conference abstracts from the past 2 years including 2010. Only prospective, randomized comparisons between iodixanol and LOCM with CI-AKI [increase in serum creatinine (sCr) ≧0.5 mg/dl or ≧25% from baseline, as defined in the trial] as a primary and/or secondary endpoint and a Jadad score ≧2 were included. A random-effects model was used to obtain pooled relative risks (RRs) for CI-AKI in analyses based on route of administration [intra-arterial (IA) or intravenous (IV)], definition of CI-AKI, and timing of sCr measurements. Results: 145 potential articles were identified, of which 25 were included in the meta-analysis. Following IA administration (n = 19), the RR for CI-AKI (≧0.5 mg/dl definition) with iodixanol, compared with LOCM, was 0.462 [95% confidence interval (CI): 0.272–0.786, p = 0.004, 15 studies]. Using the ≧25% definition, there was a lower incidence of CI-AKI with iodixanol versus LOCM, but the difference was not statistically significant (RR: 0.577, 95% CI: 0.297–1.12, p = 0.104, 11 studies). In the IV trials, there was no significant difference in the incidence of CI-AKI using either definition (≧0.5 mg/dl definition: RR: 0.967, 95% CI: 0.188–4.972, p = 0.968, 3 trials; ≧25% definition: RR: 0.656, 95% CI: 0.316–1.360, p = 0.257, 4 trials). Conclusions: IA but not IV administration of iodixanol is associated with a significantly lower risk of CI-AKI than LOCM.
Long-Term Follow-Up of Participants With Heart Failure in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)
Authors: Piller Linda B. , Baraniuk Sarah , Simpson Lara M. , Cushman William C. , Massie Barry M. , Einhorn Paula T. , Oparil Suzanne , Ford Charles E. , Graumlich James F. , Dart Richard A. , Parish David C. , Retta Tamrat M. , Cuyjet Aloysius B. , Jafri Syed Z. , Furberg Curt D. , Saklayen Mohammad G. , Thadani Udho , Probstfield Jeffrey L. , Davis Barry R. ,   for the ALLHAT Collaborative Research Group
Published: October 2011

Background—

In the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a randomized, double-blind, practice-based, active-control, comparative effectiveness trial in high-risk hypertensive participants, risk of new-onset heart failure (HF) was higher in the amlodipine (2.5–10 mg/d) and lisinopril (10–40 mg/d) arms compared with the chlorthalidone (12.5–25 mg/d) arm. Similar to other studies, mortality rates following new-onset HF were very high (≥50% at 5 years), and were similar across randomized treatment arms. After the randomized phase of the trial ended in 2002, outcomes were determined from administrative databases.

Methods and Results—

With the use of national databases, posttrial follow-up mortality through 2006 was obtained on participants who developed new-onset HF during the randomized (in-trial) phase of ALLHAT. Mean follow-up for the entire period was 8.9 years. Of 1761 participants with incident HF in-trial, 1348 died. Post-HF all-cause mortality was similar across treatment groups, with adjusted hazard ratios (95% confidence intervals) of 0.95 (0.81–1.12) and 1.05 (0.89–1.25), respectively, for amlodipine and lisinopril compared with chlorthalidone, and 10-year adjusted rates of 86%, 87%, and 83%, respectively. All-cause mortality rates were also similar among those with reduced ejection fractions (84%) and preserved ejection fractions (81%), with no significant differences by randomized treatment arm.

Conclusions—

Once HF develops, risk of death is high and consistent across randomized treatment groups. Measures to prevent the development of HF, especially blood pressure control, must be a priority if mortality associated with the development of HF is to be addressed.

Clinical Trial Registration—

http://www.clinicaltrials.gov
. Unique identifier: NCT00000542.
Maternal and Fetal Factors Associated With Mortality and Morbidity in a Multi–Racial/Ethnic Registry of Anti-SSA/Ro–Associated Cardiac Neonatal Lupus
Authors: Izmirly Peter M. , Saxena Amit , Kim Mimi Y. , Wang Dan , Sahl Sara K. , Llanos Carolina , Friedman Deborah , Buyon Jill P.
Published: October 2011

Background—

Cardiac manifestations of neonatal lupus include conduction disease and, rarely, an isolated cardiomyopathy. This study was initiated to determine the mortality and morbidity of cardiac neonatal lupus and associated risk factors in a multi–racial/ethnic US-based registry to provide insights into the pathogenesis of antibody-mediated injury and data for counseling.

Methods and Results—

Three hundred twenty-five offspring exposed to maternal anti-SSA/Ro antibodies with cardiac neonatal lupus met entry criteria. Maternal, fetal echocardiographic, and neonatal risk factors were assessed for association with mortality. Fifty-seven (17.5%) died, 30% in utero. The probability of in utero death was 6%. The cumulative probability of survival at 10 years for a child born alive was 86%. Fetal echocardiographic risk factors associated with increased mortality in a multivariable analysis of all cases included hydrops and endocardial fibroelastosis. Significant predictors of in utero death were hydrops and earlier diagnosis, and of postnatal death were hydrops, endocardial fibroelastosis, and lower ventricular rate. Isolated heart block was associated with a 7.8% case fatality rate, whereas the concomitant presence of dilated cardiomyopathy or endocardial fibroelastosis quadrupled the case fatality rate. There was a significantly higher case fatality rate in minorities compared with whites, who were at a lower risk of hydrops and endocardial fibroelastosis. Pacing was required in 70%; cardiac transplantation was required in 4 children.

Conclusion—

Nearly one fifth of fetuses who develop cardiac neonatal lupus die of complications predicted by echocardiographic abnormalities consistent with antibody-associated disease beyond the atrioventricular node. The disparity in outcomes observed between minorities and whites warrants further investigation.
Transcoronary Concentration Gradients of Circulating MicroRNAs
Authors: De Rosa Salvatore , Fichtlscherer Stephan , Lehmann Ralf , Assmus Birgit , Dimmeler Stefanie , Zeiher Andreas M.
Published: October 2011

Background—

Circulating levels of microRNA (miR) have been proposed as biomarkers for cardiovascular disease. To identify the heart as a potential source for miRs released into the circulation, we measured concentration gradients across the coronary circulation for muscle-enriched (miR-133a, miR-499, miR-208a), vascular (miR-126, miR-92a), leukocyte-related (miR-155), and platelet-enriched (miR-223) miRs.

Methods and Results—

Circulating miRs were measured by TaqMan polymerase chain reaction in EDTA-plasma simultaneously obtained from the aorta and the coronary venous sinus in patients without coronary artery disease (n=7), with stable coronary artery disease (n=31), and with troponin-positive acute coronary syndromes (n=19). Circulating levels of the muscle-enriched miR-499 (>20-fold;
P
<0.01), miR-133a (11-fold;
P
<0.01), and miR-208a (5-fold;
P
<0.01) were significantly elevated in the aorta of troponin-positive acute coronary syndrome patients compared with patients with coronary artery disease. Importantly, there was a significant increase in circulating levels of miR-499 and miR-133a across the coronary circulation in troponin-positive acute coronary syndrome patients, suggestive of a release into the coronary circulation during myocardial injury. Indeed, miR-499 concentration gradients were significantly correlated with the extent of myocardial damage as measured by high-sensitivity troponin T (
r
=0.70,
P
<0.01). In contrast, circulating levels of miR-126 (
P
=0.16) decreased during transcoronary passage in patients with evidence of myocardial injury, suggesting consumption during transcoronary passage.

Conclusions—

Muscle-enriched miR-499 and miR-133a are released from the heart into the coronary circulation on myocardial injury, whereas the vascular miR-126 is consumed during transcoronary passage. The differential regulation of circulating miRs during the transcoronary passage might provide important insights to exploit their role as cardiac biomarkers.

Clinical Trial Registration—

URL:
http://www.germanctr.de
. Unique identifier: DRKS00000207; in German Clinical Trials Registry.
Intensified Effect of Adiposity on Blood Pressure in Overweight and Obese Children
Authors: Tu Wanzhu , Eckert George J. , DiMeglio Linda A. , Yu Zhangsheng , Jung Jeesun , Pratt J. Howard
Published: October 2011

In children, blood pressure (BP) and risk for hypertension are proportional to degree of adiposity. Whether the relationship to BP is similar over the full range of adiposity is less clear. Subjects from a cohort study (n=1111; 50% male and 42% black) contributed 9102 semiannual BP and height/weight assessments. The mean enrollment age was 10.2 years, and mean follow-up was 4.5 years. Adiposity was expressed as body mass index percentile, which accounted for effects of age and sex. The following observations were made. The effect of relative adiposity on BP was minimal until the body mass index percentile reached 85, beginning of the overweight category, at which point the effect of adiposity on BP increased by 4-fold. Similarly intensified adiposity effects on BP were observed in children aged ≤10, 11 to 14 years, and ≥15 years. Serum levels of the adipose tissue-derived hormone, leptin, together with heart rate, showed an almost identically patterned relation to BP to that of body mass index percentile and BP, thus implicating a possible mediating role for leptin. In conclusion, there is a marked intensification of the influence of adiposity on BP when children reach the categories of overweight and obese. Among the possible pathways, leptin may be a potentially important mediator acting through the sympathetic nervous system (reflected in heart rate). The findings have relevance to interventions designed to prevent or treat adiposity-related increases in BP and to the analytic approaches used in epidemiological studies.
Obstructive Sleep Apnea
Authors: Pedrosa Rodrigo P. , Drager Luciano F. , Gonzaga Carolina C. , Sousa Marcio G. , de Paula Lílian K.G. , Amaro Aline C.S. , Amodeo Celso , Bortolotto Luiz A. , Krieger Eduardo M. , Bradley T. Douglas , Lorenzi-Filho Geraldo
Published: October 2011

Recognition and treatment of secondary causes of hypertension among patients with resistant hypertension may help to control blood pressure and reduce cardiovascular risk. However, there are no studies systematically evaluating secondary causes of hypertension according to the Seventh Joint National Committee. Consecutive patients with resistant hypertension were investigated for known causes of hypertension irrespective of symptoms and signs, including aortic coarctation, Cushing syndrome, obstructive sleep apnea, drugs, pheochromocytoma, primary aldosteronism, renal parenchymal disease, renovascular hypertension, and thyroid disorders. Among 125 patients (age: 52±1 years, 43% males, systolic and diastolic blood pressure: 176±31 and 107±19 mm Hg, respectively), obstructive sleep apnea (apnea-hypopnea index: >15 events per hour) was the most common condition associated with resistant hypertension (64.0%), followed by primary aldosteronism (5.6%), renal artery stenosis (2.4%), renal parenchymal disease (1.6%), oral contraceptives (1.6%), and thyroid disorders (0.8%). In 34.4%, no secondary cause of hypertension was identified (primary hypertension). Two concomitant secondary causes of hypertension were found in 6.4% of patients. Age >50 years (odds ratio: 5.2 [95% CI: 1.9–14.2];
P
<0.01), neck circumference ≥41 cm for women and ≥43 cm for men (odds ratio: 4.7 [95% CI: 1.3–16.9];
P
=0.02), and presence of snoring (odds ratio: 3.7 [95% CI: 1.3–11];
P
=0.02) were predictors of obstructive sleep apnea. In conclusion, obstructive sleep apnea appears to be the most common condition associated with resistant hypertension. Age >50 years, large neck circumference measurement, and snoring are good predictors of obstructive sleep apnea in this population.
College-Readiness Rates in Texas
Authors: Barnes Wally , Slate John R.
Published: October 2011

In this study, we examined the college-readiness rates of Black, Hispanic, and White Texas public high school graduates using archival data from the Texas Education Agency Academic Excellence Indicator System. An examination of the state college-readiness rates across a 3-year period was conducted to determine the extent to which academic achievement gaps had increased, decreased, or remained relatively large and stable among Black, Hispanic, and White high school graduates in Texas. For the 3 years of data, college-readiness rates of White students were higher than the college-readiness rates of Black and Hispanic students in reading, math, and both subjects by large margins. Of the 27 statistical analyses of college readiness, statistically significant findings were present, revealing 19 large effect sizes, one near-large effect size, one moderate effect size, and six small effect sizes. Although Black and Hispanic students increased their college-readiness rates, White students also increased their college-readiness rates in reading, math, and both subjects to maintain the status quo for student academic achievement.
Effect of Lead Use on Back and Shoulder Postural Muscle Activity in Healthy Young Adults
Authors: Johnson Daniel D. , Kirkpatrick Anne E. , Ashton-Miller James A. , Shih Albert J.
Published: October 2011

Objective: The primary goal of this study was to test the hypothesis that wearing the 3.7 kg vest portion of a radiological shielding garment (a “lead”) significantly increases lower back and shoulder muscle activity in quasistatic erect and forward-flexed postures. Secondarily, the authors examined the effects of gender and forward-flexed posture as well as their interactions with lead use.

Background: The use of a lead is mandatory for interventionalists during surgical procedures. Because the vest portion of a lead weighs considerably more than normal clothing, there is concern that its use increases the risk of developing back and shoulder pain.

Method: In a repeated-measures study design, 19 young healthy male and female adults assumed standardized erect or forward-flexed postures, both with and without wearing the vest portion of a lead. Shoulder and lower back muscle activity was measured via surface electromyography, normalized by maximum voluntary contraction values. Data were analyzed using general linear models and repeated-measures ANOVA (significant for p < .05).

Results: Use of the lead did not result in a significant increase in muscle activity in the lower back or shoulders, despite perceived increases in effort and discomfort. Posture proved to be the most significant secondary factor affecting activity in the lower back, and participant gender proved insignificant.

Conclusion: Short-term use of the lead does not appear to contribute to the incidence of back pain or injury in interventionalists. Avoiding flexed postures could more directly reduce the likelihood of pain or injury.

Application: Potential applications include assessing and improving operating room ergonomics for physicians.
Impact of Two Adjustable-Autonomy Models on the Scalability of Single-Human/Multiple-Robot Teams for Exploration Missions
Authors: Valero-Gomez Alberto , de la Puente Paloma , Hernando Miguel
Published: October 2011

Objective: The aim of this study was to evaluate two models for adjusting autonomy in mobile robots to find out the best way for the operator to interact with the system with as many robots as possible. The first model is the most used in mobile robots; the second proposes a flexible autonomy management.

Background: There are different ways of adjusting the autonomy level in man-machine systems: adjustable autonomy, in which the operator has the initiative over the autonomy level; adaptive autonomy, in which the autonomy level is adjusted depending on the task and context; and mixed initiatives. One of the drawbacks of using adjustable autonomy is that it is claimed not to be flexible enough, resulting in a high operator workload. We propose and evaluate a flexible adjustable autonomy model for robot-team supervision.

Method: Two experiments were designed to test the scalability and performance of the man-machine system with two alternative configurations for the autonomy management. The independent variable is the number of robots, and the measured variable is the man-machine system performance. The experiments are between subjects. We have used ANOVA and Bonferroni post hoc analysis for analyzing the results.

Results: On the basis of these analyses, we conclude that a flexible adjustable autonomy model results in better performance than the classic, rigid one, in which the operator directly chooses the autonomy level.

Conclusion: Flexible autonomy adjustment permits one operator to control a team of robots with better results in terms of performance and robot use, as he or she can directly act at the error level, leaving the responsibility of readjusting and resuming the task to the system and hence reducing the operator’s workload.

Application: The results can be applied to exploration robotics, mainly, in which one operator controls a team of robots. In general, these principles can be extended to other single-man/multiple-machine systems.
Using the Landmark–Route–Survey Framework to Evaluate Spatial Knowledge Obtained From Synthetic Vision Systems
Authors: Lapeyre Brigitte , Hourlier Sylvain , Servantie Xavier , N’Kaoua Bernard , Sauzéon Hélène
Published: October 2011

Objective: Using the landmark–route–survey frame-work, this research investigated the effect of synthetic vision systems (SVS) in either low or high visibility conditions on performance in wayfinding and spatial-knowledge-based tasks that probed spatial awareness.

Background: SVS are cockpit displays that depict computer-generated views of the terrain surrounding an aircraft and have been developed to support flight efficiency through improved spatial awareness. No studies have directly measured SVS impact on the three levels of spatial knowledge (landmark, route, and survey).

Method: A total of 55 nonpilots learned a route in four different experimental conditions (high or low visibility, either with or without SVS). Subsequently, they underwent four recall tasks: wayfinding, scene recognition, scene classification, and sketch map. Six dependent measures were used to probe the three levels of spatial knowledge (selection errors, sorting errors, number of landmarks depicted, bidimensional regression) and their use in the wayfinding task (direction errors, designated landmark errors, and wayfinding verbalized hesitations).

Results: SVS produced higher performance in all four tasks. The low visibility condition lowered the wayfinding and scene-recognition performance.

Conclusion: The overall results indicated that visibility mostly affected the first level of spatial knowledge (landmark) inducing a decreased wayfinding performance, whereas the use of SVS influenced the three levels of spatial knowledge (route and survey) inducing an increased wayfinding performance.

Application: Potential applications of this work include spatial knowledge-based measures to evaluate SVS prototypes as well as to assess the relationship between spatial knowledge and spatial awareness.
Jonah’s Peculiar Re-Creation
Authors: Edmund Anderson Joel
Published: October 2011

With the rise of narrative criticism within Biblical Studies, there has been an increasing recognition of the importance of reading biblical texts as literature. The meaning and message of a given text is intimately tied to the way in which that text is written, and that includes its literary structure, as well as any intertextual connections to other earlier biblical texts. This article will argue that a narrative reading of Jonah reveals numerous intertextual connections to both the ancient Near Eastern imagery found in creation/Eden accounts of Genesis 1—3 and the recreation/flood narrative of Genesis 6—9. The theological impact these connections have on the message of Jonah to its postexilic audience is significant, in that it addresses not only the issue of the re-created people of God, but also the importance and purpose of the Temple. This article, therefore, is essentially an exercise in synchronic readings and intertextuality set within the historical parameters of the postexilic Jewish community.
Mobile and Landline Telephone Performance Outcomes among Telephone‐Using Cochlear Implant Recipients
Authors: Tan Barrie Yau Boon , Gluth Michael Brian , Statham Elle Louise , Eikelboom Robert Henry , Atlas Marcus David
Published: October 2011

Objective

To objectively study mobile and standard landline telephone speech perception performance using cochlear implant recipients.

Study Design

Nonrandomized trial.

Setting

Tertiary referral center.

Subjects and Methods

Twenty‐five subjects enrolled in this study from a pool of 50 cochlear implant recipients who had participated in an earlier questionnaire study from which demographic data were gathered. Preoperative speech perception scores were collated from preoperative audiological data. Postoperative speech perception scores were calculated with subjects listening to the Australian Version of the Bamford‐Kowal‐Bench Sentence Test read aloud in a soundproof booth via live voice, played back on a speaker, on a standard landline and mobile phone. Telephone speech perception scores were analyzed and banded into 3 performance categories: very good (90%‐100%), good (80%‐89%), and fair (<80%).

Results

The mean speech perception scores were 88.6% (SD, 14.3%) for postoperative recorded speech and 92.3% (SD, 10.7%) for live voice listening, which were significantly better than the mean score of 37.2% (SD, 29.1%) listening to recorded voice preoperatively. The mean speech perception score was 84.3% (SD, 20.7%) using a mobile telephone and 57% (SD, 29.4%) using the standard landline. Further analysis showed better performance with mobile phones over standard landlines. Seventy‐six percent of subjects attained at least good telephone speech performance (score >80%). Older patients had poorer telephone speech perception than younger patients did.

Conclusions

Many cochlear implant recipients achieve good objective telephone speech perception performance, indicating that they should be effective telephone users, especially when using mobile telephones and among younger implant recipients.
Barriers and facilitators to the receipt of palliative care for people with dementia: The views of medical and nursing staff
Authors: Ryan Tony , Gardiner Clare , Bellamy Gary , Gott Merryn , Ingleton Christine
Published: October 2011

Background:

The global prevalence of dementia is set to rise to almost 65 million people by 2030, providing policy makers and practitioners with significant challenges, not least within the realms of end-of-life care. The international literature would suggest that people with dementia may benefit from palliative forms of care, but evidence indicates that many fail to access such provision at the end of life. The role of the health care team is pivotal if people with dementia are to benefit from the transition to palliative care.

Aim:

This paper reports on qualitative research conducted in the UK that sought to explore the experiences of health care practitioners working in palliative care and sought to establish the issues relating to end-of-life care for people with dementia.

Design:

Eight focus groups and four individual interviews were held. Data were analysed using a thematic approach.

Setting/participants:

The study included palliative care practitioners (n = 58) including medical, nursing and allied health professionals. Participants were recruited from acute hospitals, general practice, hospices and specialist palliative care units in the UK.

Results:

Four themes were identified: Making the transition; Competence challenged; ‘The long view’ and Working together. Whilst there exists good practice in this area, the barriers to timely and appropriate transitions to palliative care for people with dementia and their families continue to exist. The paper concludes with recommendations for policy and practice development.
Kingdom of the Blind
Authors: Benfodil's Mustapha
Published: October 2011

Writer and artist Mustapha Benfodil’s installation was removed from the Sharjah Biennial: Index publishes the text that caused offence
Spaces of Freedom
Authors: Merali Shaheen
Published: October 2011

Shaheen Merali talks to Rozita Sharafjahan, artist and director of the pioneering Azad Gallery in Tehran about pushing the boundaries
Fool for Art
Authors: Kelly Jude
Published: October 2011

Society needs to protect not only the right to artistic expression, but also the artist’s work, regardless of aesthetic value, says Jude Kelly
Russia's Robin Hood
Authors: Sturdee Nick
Published: October 2011

Widespread frustration with the establishment has fostered a brand of political street art that’s taking the country by storm. Nick Sturdee reports
Economic valuation and the commodification of ecosystem services
Authors: Gómez-Baggethun Erik , Ruiz-Pérez Manuel
Published: October 2011

In the last decade a growing number of environmental scientists have advocated economic valuation of ecosystem services as a pragmatic short-term strategy to communicate the value of biodiversity in a language that reflects dominant political and economic views. This paper revisits the controversy on economic valuation of ecosystem services in the light of two aspects that are often neglected in ongoing debates. First, the role of the particular institutional setup in which environmental policy and governance is currently embedded in shaping valuation outcomes. Second, the broader economic and sociopolitical processes that have governed the expansion of pricing into previously non-marketed areas of the environment. Our analysis suggests that within the institutional setup and broader sociopolitical processes that have become prominent since the late 1980s economic valuation is likely to pave the way for the commodification of ecosystem services with potentially counterproductive effects in the long term for biodiversity conservation and equity of access to ecosystem services benefits.
Measuring, modeling and mapping ecosystem services in the Eastern Arc Mountains of Tanzania
Authors: Fisher Brendan , Turner R. Kerry , Burgess Neil D. , Swetnam Ruth D. , Green Jonathan , Green Rhys E. , Kajembe George , Kulindwa Kassim , Lewis Simon L. , Marchant Rob , Marshall Andrew R. , Madoffe Seif , Munishi P.K.T. , Morse-Jones Sian , Mwakalila Shadrack , Paavola Jouni , Naidoo Robin , Ricketts Taylor , Rouget Mathieu , Willcock Simon , White Sue , Balmford Andrew
Published: October 2011

In light of the significance that ecosystem service research is likely to play in linking conservation activities and human welfare, systematic approaches to measuring, modeling and mapping ecosystem services (and their value to society) are sorely needed. In this paper we outline one such approach, which we developed in order to understand the links between the functioning of the ecosystems of Tanzania’s Eastern Arc Mountains and their impact on human welfare at local, regional and global scales. The essence of our approach is the creation of a series of maps created using field-based or remotely sourced data, data-driven models, and socio-economic scenarios coupled with rule-based assumptions. Here we describe the construction of this spatial information and how it can help to shed light on the complex relationships between ecological and social systems. There are obvious difficulties in operationalizing this approach, but by highlighting those which we have encountered in our own case-study work, we have also been able to suggest some routes to overcoming these impediments.