bluuebunny/crossref_metadata_2025_split huggingface dataset:
Idempotent work stealing
Authors: Michael Maged M. , Vechev Martin T. , Saraswat Vijay A. 
Published: August 2009

Load balancing is a technique which allows efficient parallelization of irregular workloads, and a key component of many applications and parallelizing runtimes. Work-stealing is a popular technique for implementing load balancing, where each parallel thread maintains its own work set of items and occasionally steals items from the sets of other threads.
The conventional semantics of work stealing guarantee that each inserted task is eventually extracted exactly once. However, correctness of a wide class of applications allows for relaxed semantics, because either: i) the application already explicitly checks that no work is repeated or ii) the application can tolerate repeated work.

In this paper, we introduce
idempotent work tealing
, and present several new algorithms that exploit the relaxed semantics to deliver better performance. The semantics of the new algorithms guarantee that each inserted task is eventually extracted
at least
once-instead of
exactly
once.

On mainstream processors, algorithms for conventional work stealing require special atomic instructions or store-load memory ordering fence instructions in the owner's critical path operations. In general, these instructions are substantially slower than regular memory access instructions. By exploiting the relaxed semantics, our algorithms avoid these instructions in the owner's operations.
We evaluated our algorithms using common graph problems and micro-benchmarks and compared them to well-known conventional work stealing algorithms, the THE Cilk and Chase-Lev algorithms. We found that our best algorithm (with LIFO extraction) outperforms existing algorithms in nearly all cases, and often by significant margins.
Comparability graph coloring for optimizing utilization of stream register files in stream processors
Authors: Yang Xuejun , Wang Li , Xue Jingling , Deng Yu , Zhang Ying 
Published: August 2009

A stream processor executes an application that has been decomposed into a sequence of kernels that operate on streams of data elements. During the execution of a kernel, all streams accessed must be communicated through the SRF (Stream Register File), a non-bypassing software-managed on-chip memory. Therefore, optimizing utilization of the SRF is crucial for good performance. The key insight is that the interference graphs formed by the streams in stream applications tend to be comparability graphs or decomposable into a set of multiple comparability graphs. We present a compiler algorithm that can find optimal or near-optimal colorings in stream IGs, thereby improving SRF utilization than the First-Fit
bin-packing algorithm, the best in the literature.
Committing conflicting transactions in an STM
Authors: Ramadan Hany E. , Roy Indrajit , Herlihy Maurice , Witchel Emmett 
Published: August 2009

Dependence-aware transactional memory (DATM) is a recently proposed model for increasing concurrency of memory transactions without complicating their interface. DATM manages dependences between conflicting, uncommitted transactions so that they commit safely.
The contributions of this paper are twofold. First, we provide a safety proof for the dependence-aware model. This proof also shows that the DATM model accepts all concurrent interleavings that are conflict-serializable.
Second, we describe the first application of dependence tracking to software transactional memory (STM) design and implementation. We compare our implementation with a state of the art STM, TL2 [4]. We use benchmarks from the STAMP [21] suite, quantifying how dependence tracking converts certain types of transactional conflicts into successful commits. On high contention workloads, DATM is able to take advantage of dependences to speed up execution by up to 4.8x.
Re-Visioning the Interface: Technological Fashion
Authors: Ryan Susan Elizabeth 
Published: August 2009

This paper elucidates two positions (the positivist and the critical) that inform the creative design of technological fashion. On the one side is the instrumentalist trend toward the minimized or disappearing interface. On the other, some theorists and artists suggest that increased invisibility presents social and ethical concerns (such as invasiveness and control) when networking and communication devices are involved. The positivist side has roots in modernist design. Positivist designers create responsive and controllable fabrics using shape-changing polymers, e-textiles, and nano-scale electronics to resolve clumsy and prohibitive problems of hardware vs. body. The critical side draws upon archetypal ideas about technology and the body that are familiar from literature and science fiction, and includes writers and media artists who emphasize the intractable or mechanic nature of technological clothing to enhance, rather than erase, the body. The paper concludes that both positions must be considered as the field of technological fashion moves forward.
Selective Population Rate Coding: A Possible Computational Role of Gamma Oscillations in Selective Attention
Authors: Masuda Naoki 
Published: August 2009

Abstract
Selective attention is often accompanied by gamma oscillations in local field potentials and spike field coherence in brain areas related to visual, motor, and cognitive information processing. Gamma oscillations are implicated to play an important role in, for example, visual tasks including object search, shape perception, and speed detection. However, the mechanism by which gamma oscillations enhance cognitive and behavioral performance of attentive subjects is still elusive. Using feedforward fan-in networks composed of spiking neurons, we examine a possible role for gamma oscillations in selective attention and population rate coding of external stimuli. We implement the concept proposed by Fries (2005) that under dynamic stimuli, neural populations effectively communicate with each other only when there is a good phase relationship among associated gamma oscillations. We show that the downstream neural population selects a specific dynamic stimulus received by an upstream population and represents it by population rate coding. The encoded stimulus is the one for which gamma rhythm in the corresponding upstream population is resonant with the downstream gamma rhythm. The proposed role for gamma oscillations in stimulus selection is to enable top-down control, a neural version of time division multiple access used in communication engineering.
Aerosol Effects on Intensity of Landfalling Hurricanes as Seen from Simulations with the WRF Model with Spectral Bin Microphysics
Authors: Khain A. , Lynn B. , Dudhia J. 
Published: August 2009

AbstractThe evolution of a superhurricane (Katrina, August 2005) was simulated using the Weather Research and Forecasting Model (WRF; version 3.1) with explicit (nonparameterized) spectral bin microphysics (SBM). The new computationally efficient spectral bin microphysical scheme (FAST-SBM) implemented to the WRF calculates at each time step and in each grid point the size distributions of atmospheric aerosols, water drops, cloud ice (ice crystals and aggregates), and graupel/hail. The tropical cyclone (TC) evolution was simulated during 72 h, beginning with its bypassing the Florida coast (27 August 2005) to its landfall just east of New Orleans, Louisiana (near the end of 29 August). The WRF/SBM was used to investigate the potential impact of aerosols ingested into Katrina’s circulation during its passage through the Gulf of Mexico on Katrina’s structure and intensity. It is shown that continental aerosols invigorated convection largely at TC periphery, which led to its weakening prior to landfall. Maximum weakening took place ∼24 h before landfall, just after its intensity had reached its maximum. The minimum pressure increased by ∼15 hPa, and the maximum velocity decreased up to 15 m s−1. Thus, the model results indicate the existence of another (in addition to a decrease in the surface fluxes) mechanism of weakening of TCs approaching the land. This mechanism is related to effects of continental aerosols involved in the TC circulation. It is shown that aerosols substantially affect the spatial distribution of cloudiness and hydrometeor contents. The evolution of lightning structure within the TC is calculated and compared with that in Katrina. The physical mechanisms of aerosol-induced TC weakening are discussed.
Spatial Variation and Trends in PDSI and SPI Indices and Their Relation to Streamflow in 10 Large Regions of China
Authors: Zhai Jianqing , Su Buda , Krysanova Valentina , Vetter Tobias , Gao Chao , Jiang Tong 
Published: August 2009

Abstract
Time series of the average annual Palmer drought severity index (PDSI) and standardized precipitation index (SPI) were calculated for 483 meteorological stations in China using monthly data from 1961 to 2005. The time series were analyzed for 10 large regions covering the territory of China and represented by seven river basins and three areas in the southeast, southwest, and northwest. Results show that the frequencies of both dry and wet years for the whole period are lower for southern basins than for the northern ones when estimated by PDSI but very similar for all basins when calculated by SPI. The frequencies of dry and wet years calculated for 5- and 15-yr subperiods by both indices show the upward dry trends for three northeastern basins, Songhuajiang, Liaohe, and Haihe; a downward dry trend for the northwest region; a downward wet trend for the Yellow River basin; and an upward wet trend for the northwest region. Trend detection using PDSI indicates statistically significant negative trends for many stations in the northeastern basins (Songhuajiang, Liaohe, Haihe, and Yellow) and in the middle part of the Yangtze, whereas statistically significant positive trends were found in the mountainous part of the northwest region and for some stations in the upper and lower Yangtze. A moderately high and statistically significant correlation between the percentage of runoff anomaly (PRA) and the annual average PDSI and SPI was found for six large rivers. The results confirm that PDSI and SPI indices can be used to describe the tendency of dryness and wetness severity and for comparison in climate impact assessment.
Coupled Ocean–Atmosphere Response to Idealized Freshwater Forcing over the Western Tropical Pacific
Authors: Wu Lixin , Sun Yan , Zhang Jiaxu , Zhang Liping , Minobe Shoshiro 
Published: August 2009

Abstract
The coupled ocean–atmosphere responses to idealized freshwater forcing in the western tropical Pacific are studied using a fully coupled climate model. The model explicitly demonstrates that freshwater forcing in the western tropical Pacific can lead to a basinwide response with the pattern resembling the Pacific decadal oscillation. In the tropics, a negative (positive) freshwater forcing over the western tropical Pacific decreases (increases) sea surface height locally, and sets up a positive (negative) zonal pressure gradient anomaly, which accelerates (decelerates) the meridional overturning circulation and equatorial surface westward flow. This leads to an intensification (reduction) of meridional heat divergence and vertical cold advection, and thus a development of La Niña (El Niño)–like responses in the tropics. The tropical responses are further substantiated by the positive Bjerknes feedback, and subsequently force significant changes in the extratropical North Pacific through atmospheric teleconnection. The local freshwater response also reinforces the imposed forcing, forming a positive feedback loop. Applications to Pacific climate changes are discussed.
Climatic Impact of Global-Scale Deforestation: Radiative versus Nonradiative Processes
Authors: Davin Edouard L. , de Noblet-Ducoudré Nathalie 
Published: August 2009

Abstract
A fully coupled land–ocean–atmosphere GCM is used to explore the biogeophysical impact of large-scale deforestation on surface climate. By analyzing the model sensitivity to global-scale replacement of forests by grassland, it is shown that the surface albedo increase owing to deforestation has a cooling effect of −1.36 K globally. On the other hand, forest removal decreases evapotranspiration efficiency and decreases surface roughness, both leading to a global surface warming of 0.24 and 0.29 K, respectively. The net biogeophysical impact of deforestation results from the competition between these effects. Globally, the albedo effect is dominant because of its wider-scale impact, and the net biogeophysical impact of deforestation is thus a cooling of −1 K. Over land, the balance between the different processes varies with latitude. In temperate and boreal zones of the Northern Hemisphere the albedo effect is stronger and deforestation thus induces a cooling. Conversely, in the tropics the net impact of deforestation is a warming, because evapotranspiration efficiency and surface roughness provide the dominant influence. The authors also explore the importance of the ocean coupling in shaping the climate response to deforestation. First, the temperature over ocean responds to the land cover perturbation. Second, even the temperature change over land is greatly affected by the ocean coupling. By assuming fixed oceanic conditions, the net effect of deforestation, averaged over all land areas, is a warming, whereas taking into account the coupling with the ocean leads, on the contrary, to a net land cooling. Furthermore, it is shown that the main parameter involved in the coupling with the ocean is surface albedo. Indeed, a change in albedo modifies temperature and humidity in the whole troposphere, thus enabling the initially land-confined perturbation to be transferred to the ocean. Finally, the radiative forcing framework is discussed in the context of land cover change impact on climate. The experiments herein illustrate that deforestation triggers two opposite types of forcing mechanisms—radiative forcing (owing to surface albedo change) and nonradiative forcing (owing to change in evapotranspiration efficiency and surface roughness)—that exhibit a similar magnitude globally. However, when applying the radiative forcing concept, nonradiative processes are ignored, which may lead to a misrepresentation of land cover change impact on climate.
A Numerical Study on the Atmospheric Circulation over the Midlatitude North Pacific during the Last Glacial Maximum
Authors: Yanase Wataru , Abe-Ouchi Ayako 
Published: August 2009

Abstract
The dynamics of the atmospheric circulation change over the midlatitude North Pacific under the boundary conditions during the last glacial maximum (LGM) have been studied by atmospheric general circulation models (GCMs) with different ocean feedbacks. Three boundary conditions in the LGM were different from those of the present day (PD): ice sheet with elevated topography and high albedo, atmospheric CO2 concentration, and insolation. The ocean component was treated as follows: a full-circulation ocean with dynamical and thermal ocean feedback [coupled general circulation model (CGCM)]; a slab ocean only with thermal feedback used to calculate the surface heat balance [slab ocean GCM (SGCM)]; and no ocean feedback by fixing sea surface temperature (SST) with pure atmospheric dynamics (AGCM). Both CGCM and SGCM simulated a weakened Pacific high pressure system in boreal summer during the LGM compared to the PD and an intensified Aleutian low pressure system in winter. Both in summer and winter, therefore, the lower-tropospheric circulation during the LGM showed midlatitude North Pacific cyclonic anomalies (NPCAs).
To understand the dynamics determining the NPCAs, the sensitivity of the atmospheric response to the three boundary conditions were examined using the SGCM. It was shown that the high albedo of the ice sheet over North America was the dominant factor behind the NPCAs in both summer and winter. The ocean thermal feedback in winter played an essential role in the formation of the NPCA through SST change, while the ocean thermal feedback in summer and ocean dynamical feedback played secondary roles in the intensification of the NPCA. Possible mechanisms were inferred from the common features related to the NPCA formation in the experiments. In summer, the midlatitude NPCA was associated with the reduced land–ocean contrast of diabatic heating between the North Pacific and North America, which is consistent with theoretical studies on the mechanism for formation of subtropical high pressure systems. In winter, on the other hand, the anomaly of the SST gradient at midlatitude is thought to result in the NPCA through the modulation of heat and momentum transport in the storm track.
The small (large) sensitivity of the NPCA formation to the ocean feedbacks in summer (winter) explains the strong (weak) consistency among the previous GCM experiments. Since the NPCAs are consistent with some geological records, the present study should be informative in understanding the actual dynamics of the LGM climate change.
On Sea Surface Salinity Skin Effect Induced by Evaporation and Implications for Remote Sensing of Ocean Salinity
Authors: Yu Lisan 
Published: August 2009

Abstract
The existence of a cool and salty sea surface skin under evaporation was first proposed by Saunders in 1967, but few efforts have since been made to perceive the salt component of the skin layer. With two salinity missions scheduled to launch in the coming years, this study attempted to revisit the Saunders concept and to utilize presently available air–sea forcing datasets to analyze, understand, and interpret the effect of the salty skin and its implication for remote sensing of ocean salinity.
Similar to surface cooling, the skin salinification would occur primarily at low and midlatitudes in regions that are characterized by low winds or high evaporation. On average, the skin is saltier than the interior water by 0.05–0.15 psu and cooler by 0.2°–0.5°C. The cooler and saltier skin at the top is always statically unstable, and the tendency to overturn is controlled by cooling. Once the skin layer overturns, the time to reestablish the full increase of skin salinity was reported to be on the order of 15 min, which is approximately 90 times slower than that for skin temperature. Because the radiation received from a footprint is averaged over an area to give a single pixel value, the slow recovery by the salt diffusion process might cause a slight reduction in area-averaged skin salinity and thus obscure the salty skin effect on radiometer retrievals. In the presence of many geophysical error sources in remote sensing of ocean salinity, the salt enrichment at the surface skin does not appear to be a concern.
Gene expression profiling of maternal blood in early onset severe preeclampsia: identification of novel biomarkers
Authors: Sun Cheng-Juan , Zhang Liang , Zhang Wei-Yuan 
Published: August 2009

AbstractAims:To investigate candidate genes in peripheral blood mononuclear cell (PBMC) that are associated with early onset severe preeclampsia (ES-PE) and to describe candidate genes function using microarrays and real-time polymerase chain reaction (PCR).Methods:PBMC RNA was extracted from six patients with ES-PE and five uncomplicated pregnancies. The HG_U133 plus 2.0 Affymetrix GeneChips that represented 47,000 genes were used to measure gene expression in each sample. Significance analysis of microarray identified potential signature genes characterizing ES-PE vs. uncomplicated pregnancies. Eight genes were selected for confirmation by real-time PCR of 32 patients with ES-PE and 24 uncomplicated pregnancies, matched for maternal age, parity, race and gestational weeks.Results:Using a whole-genome approach to study the molecular determinants of ES-PE, 72 genes were found to be differentially expressed between cases and controls, including 38 up-regulated genes and 34 down-regulated genes in the group of ES-PE. Killer cell immunoglobulin-like receptor, three domains, long cytoplasmic tail, 2 (KIR3DL2), aldo-keto reductase family 1, member C3 (AKR1C3), churchill domain containing 1 (CHURC1), and solute carrier family 25, member 13 (SLC25A13) were validated to be down-regulated in the patients with ES-PE by real-time PCR.Conclusions:Expression of genes with diverse function is associated with ES-PE risk, providing opportunities for the development of non-invasive diagnosis.
Delivery mode for the extremely premature fetus: a statement of the prematurity working group of the World Association of Perinatal Medicine
Authors: Skupski Daniel W. , Greenough Anne , Donn Stephen M. , Arabin Birgit , Bancalari Eduardo , Vladareanu Radu 
Published: August 2009

Abstract
Recent retrospective publications have suggested that cesarean delivery may be beneficial for the extremely premature fetus. This article displays the available evidence and discusses this issue, including many aspects such as the difficulty in deciding when delivery is imminent, the negative impact on maternal morbidity and mortality and the cost to society of such a policy. The available scientific evidence does not support a recommendation for cesarean delivery for improving survival or decreasing morbidity for the extremely premature fetus.
Fetal Growth Restriction and Chronic Lung Disease Among Infants Born Before the 28th Week of Gestation
Authors: Bose Carl , Van Marter Linda J. , Laughon Matthew , O'Shea T. Michael , Allred Elizabeth N. , Karna Padmani , Ehrenkranz Richard A. , Boggess Kim , Leviton Alan ,   for the Extremely Low Gestational Age Newborn Study Investigators
Published: August 2009

OBJECTIVE: Improvement in survival of extremely premature infants over the past several decades has resulted in an increase in the number of infants with chronic lung disease (CLD). Historical neonatal exposures associated with CLD now less frequently precede the disease. There is now increasing interest in exposures and events before delivery that predict CLD. The objective of this study was to identify current prenatal predictors of CLD.METHODS: We collected data about prenatal, placental, and neonatal characteristics of 1241 newborns who were delivered before completion of the 28th week of gestation. Associations between prenatal factors, microbiologic and histologic characteristics of the placenta, and selected neonatal characteristics and CLD risk were first evaluated in univariate analyses. Subsequent multivariate analyses investigated the contribution of prenatal factors, particularly fetal growth restriction (FGR), to CLD risk.RESULTS: Among the prenatal factors, birth weight z scores, used as a marker of FGR, provided the most information about CLD risk. Indicators of placental inflammation and infection were not associated with increased risk of CLD. Within nearly all strata of prenatal, placental, and neonatal variables, growth-restricted infants were at increased CLD risk, compared with infants who were not growth-restricted. FGR was the only maternal or prenatal characteristic that was highly predictive of CLD after adjustment for other risk factors.CONCLUSIONS: FGR is independently associated with the risk of CLD. Thus, factors that control fetal somatic growth may have a significant impact on vulnerability to lung injury and in this way increase CLD risk.