bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Three Prolonged Periods of Heavy Rainfall over the Hawaiian Islands
Authors: Jayawardena I. M. Shiromani , Chen Yi-Leng , Nash Andrew J. , Kodama Kevin 
Published: January 2012

AbstractThe anomalous circulation patterns during an unusually prolonged stormy-weather period in Hawaii from 19 February to 2 April 2006 are analyzed and are compared with those of two previously known prolonged heavy-rainfall periods (March 1951 and February 1979). The circulation patterns for these three periods are characterized by 1) a negative Pacific–North American (PNA) pattern in the midlatitudes with a blocking high southwest of the Aleutian Islands, 2) retraction and splitting of the zonal jet into a polar jet north of 50°N and a persistent subtropical jet to the south over the central Pacific Ocean, 3) an anomalous low west of the Hawaiian Islands embedded in the subtropical jet, and 4) a weaker-than-normal Hadley circulation in the mid-Pacific. The moisture advected from low latitudes by the southerly wind component east of the persistent anomalous low, combined with upward motion, provides the large-scale setting for the unusually prolonged unsettled weather across the Hawaiian Islands. For all three cases, the prolonged stormy weather started after the onset of large-scale blocking and a negative PNA pattern over the North Pacific and the occurrence of a persistent anomalous low embedded in the subtropical jet west of the Hawaiian Islands. Furthermore, the persistent low was located at the optimal position to bring moisture from the central equatorial Pacific to Hawaii. The stormy weather ceased after the midlatitude blocking pattern weakened and the anomalous low in the subtropics decayed and/or shifted westward. There are no apparent common precursors in the 2-week period prior to the prolonged stormy weather among these three cases, however.
Interannual Variability of Indian Summer Monsoon arising from Interactions between Seasonal Mean and Intraseasonal Oscillations
Authors: Suhas E. , Neena J. M. , Goswami B. N. 
Published: January 2012

AbstractA significant fraction of interannual variability (IAV) of the Indian summer monsoon (ISM) is known to be governed by “internal” dynamics arising from interactions between high-frequency fluctuations and the annual cycle. While several studies indicate that monsoon intraseasonal oscillations (MISOs) are at the heart of such internal IAV of the monsoon, the exact mechanism through which MISOs influence the seasonal mean monsoon IAV has remained elusive so far. Here it is proposed that exchange of kinetic energy (KE) between the seasonal mean and MISOs provides a conceptual framework for understanding the role of intraseasonal oscillations (ISOs) in causing IAV and interdecadal variability (IDV) of the ISM. The rate of KE exchange between seasonal mean and ISOs is calculated in frequency domain for each Northern Hemispheric summer season over the ISM domain, using 44 yr of the 40-yr ECMWF Re-Analysis (ERA-40) data. The seasonal mean KE and the rate of KE exchange between seasonal mean and ISO shows a significant relationship at both the 850- and 200-hPa pressure levels. Since the rate of KE exchange between seasonal mean and ISO is found to be independent of known external forcing, the variability in seasonal mean KE arising from this exchange process can be considered as an internal component explaining about 20% of IAV and about 50% of IDV. Contrary to the many modeling studies attributing the weakening of tropical circulation to the stabilization of the atmosphere by global warming, this paper provides an alternative view that internal dynamics arising from scale interactions might be playing a significant role in determining the decreasing strength of the monsoon circulation.
Meteorological Causes of the Secular Variations in Observed Extreme Precipitation Events for the Conterminous United States
Authors: Kunkel Kenneth E. , Easterling David R. , Kristovich David A. R. , Gleason Byron , Stoecker Leslie , Smith Rebecca 
Published: January 2012

Abstract
Daily extreme precipitation events, exceeding a threshold for a 1-in-5-yr occurrence, were identified from a network of 935 Cooperative Observer stations for the period of 1908–2009. Each event was assigned a meteorological cause, categorized as extratropical cyclone near a front (FRT), extratropical cyclone near center of low (ETC), tropical cyclone (TC), mesoscale convective system (MCS), air mass (isolated) convection (AMC), North American monsoon (NAM), and upslope flow (USF). The percentage of events ascribed to each cause were 54% for FRT, 24% for ETC, 13% for TC, 5% for MCS, 3% for NAM, 1% for AMC, and 0.1% for USF. On a national scale, there are upward trends in events associated with fronts and tropical cyclones, but no trends for other meteorological causes. On a regional scale, statistically significant upward trends in the frontal category are found in five of the nine regions. For ETCs, there are statistically significant upward trends in the Northeast and east north central. For the NAM category, the trend in the West is upward. The central region has seen an upward trend in events caused by TCs.
A Bias in the Midtropospheric Channel Warm Target Factor on the NOAA-9 Microwave Sounding Unit
Authors: Po-Chedley Stephen , Fu Qiang 
Published: January 2012

Abstract
The University of Alabama at Huntsville (UAH), Remote Sensing Systems (RSS), and the National Oceanic and Atmospheric Administration (NOAA) have constructed long-term temperature records for deep atmospheric layers using satellite Microwave Sounding Unit (MSU) and Advanced Microwave Sounding Unit (AMSU) observations. However, these groups disagree on the magnitude of global temperature trends since 1979, including the trend for the midtropospheric layer (TMT). This study evaluates the selection of the MSU TMT warm target factor for the NOAA-9 satellite using five homogenized radiosonde products as references. The analysis reveals that the UAH TMT product has a positive bias of 0.051 ± 0.031 in the warm target factor that artificially reduces the global TMT trend by 0.042 K decade−1 for 1979–2009. Accounting for this bias increases the global UAH TMT trend from 0.038 to 0.080 K decade−1, effectively eliminating the trend difference between UAH and RSS and decreasing the trend difference between UAH and NOAA by 47%. This warm target factor bias directly affects the UAH lower tropospheric (TLT) product and tropospheric temperature trends derived from a combination of TMT and lower stratospheric (TLS) channels.
Oral Repeated-Dose Toxicity Studies of Coenzyme Q10 in Beagle Dogs
Authors: Yerramilli-Rao Padmaja , Beal M. Flint , Watanabe Dai , Kieburtz Karl , Blieck Elisabeth A. de , Kitano Mitsuaki , Hosoe Kazunori , Funahashi Iwao , Cudkowicz Merit E. 
Published: January 2012

To support phase III testing of coenzyme Q10 (CoQ10) in humans, we conducted pharmacokinetic and toxicology studies in beagle dogs. Following single gavage administration of CoQ10 at 600, 1200, 1800, or 2400 mg/kg per d no obvious dose response was observed in maximum concentration ( Cmax) or area under the curve (AUC) versus time curve at the 3 highest dosages. In a repeated-dose study of CoQ10 at 600, 1200, 1800, or 2400 mg/kg per d for 4 weeks, CoQ10 reached steady state in plasma by 2 weeks at all dosages. Both Cmax and AUC increased with increasing dosage of CoQ10. The highest plasma levels were recorded at 1800 mg/kg per d. In a 39-week chronic toxicity study of CoQ10 at 1200 and 1800 mg/kg per d or placebo, CoQ10 reached steady state in plasma by 13 weeks. Behaviors, blood chemistries, and detailed histopathology were normal. No deaths occurred. These results support the use of a 2400 mg/d dosage of CoQ10 in human clinical trials.
GATA-3 regulates hematopoietic stem cell maintenance and cell-cycle entry
Authors: Ku Chia-Jui , Hosoya Tomonori , Maillard Ivan , Engel James Douglas 
Published: January 2012

AbstractMaintaining hematopoietic stem cell (HSC) quiescence is a critical property for the life-long generation of blood cells. Approximately 75% of cells in a highly enriched long-term repopulating HSC (LT-HSC) pool (Lin−Sca1+c-KithiCD150+CD48−) are quiescent, with only a small percentage of the LT-HSCs in cycle. Transcription factor GATA-3 is known to be vital for the development of T cells at multiple stages in the thymus and for Th2 differentiation in the peripheral organs. Although it is well documented that GATA-3 is expressed in HSCs, a role for GATA-3 in any prethymic progenitor cell has not been established. In the present study, we show that Gata3-null mutant mice generate fewer LT-HSCs and that fewer Gata3-null LT-HSCs are in cycle. Furthermore, Gata3 mutant hematopoietic progenitor cells fail to be recruited into an increased cycling state after 5-fluorouracil–induced myelosuppression. Therefore, GATA-3 is required for the maintenance of a normal number of LT-HSCs and for their entry into the cell cycle.
Novel myeloma-associated antigens revealed in the context of syngeneic hematopoietic stem cell transplantation
Authors: Biernacki Melinda A. , Tai Yu-tzu , Zhang Guang Lan , Alonso Anselmo , Zhang Wandi , Prabhala Rao , Zhang Li , Munshi Nikhil , Neuberg Donna , Soiffer Robert J. , Ritz Jerome , Alyea Edwin P. , Brusic Vladimir , Anderson Kenneth C. , Wu Catherine J. 
Published: January 2012

Abstract
Targets of curative donor-derived graft-versus-myeloma (GVM) responses after allogeneic hematopoietic stem cell transplantation (HSCT) remain poorly defined, partly because immunity against minor histocompatibility Ags (mHAgs) complicates the elucidation of multiple myeloma (MM)–specific targets. We hypothesized that syngeneic HSCT would facilitate the identification of GVM-associated Ags because donor immune responses in this setting should exclusively target unique tumor Ags in the absence of donor-host genetic disparities. Therefore, in the present study, we investigated the development of tumor immunity in an HLA-A0201+ MM patient who achieved durable remission after myeloablative syngeneic HSCT. Using high-density protein microarrays to screen post-HSCT plasma, we identified 6 Ags that elicited high-titer (1:5000-1:10 000) Abs that correlated with clinical tumor regression. Two Ags (DAPK2 and PIM1) had enriched expression in primary MM tissues. Both elicited Ab responses in other MM patients after chemotherapy or HSCT (11 and 6 of 32 patients for DAPK2 and PIM1, respectively). The index patient also developed specific CD8+ T-cell responses to HLA-A2–restricted peptides derived from DAPK2 and PIM1. Peptide-specific T cells recognized HLA-A2+ MM-derived cell lines and primary MM tumor cells. Coordinated T- and B-cell immunity develops against MM-associated Ags after syngeneic HSCT. DAPK1 and PIM1 are promising target Ags for MM-directed immunotherapy.
Imprecise Data Sets as a Source of Ambiguity: A Model and Experimental Evidence
Authors: Arad Ayala , Gayer Gabrielle 
Published: January 2012

In many circumstances, evaluations are based on empirical data. However, some observations may be imprecise, meaning that it is not entirely clear what occurred in them. We address the question of how beliefs are formed in these situations. The individual in our model is essentially a “frequentist.” He first makes a subjective judgment about the occurrence of the event for each imprecise observation. This may be any number between zero and one. He then evaluates the event by its “subjective” frequency of occurrence. Our model connects the method of processing imprecise observations with the individual's attitude toward ambiguity. An individual who in imprecise observations puts low (high) weight on the possibility that an event occurred is ambiguity averse (loving). An experiment supports the main assertions of the model: with precise data, subjects behave as if there were no ambiguity, whereas with imprecise data subjects turn out to be ambiguity averse.This paper was accepted by Brad Barber, Teck Ho, and Terrance Odean, special issue editors.
The Evolution of the Drillstring Design on Puguang Sour Field to Improve Performance and Safety Margins in Sour Environments
Authors: Flores Vincent , El Bachiri Kamal , Fei Li , Yumin Li , Zhang Da 
Published: January 2012

Abstract
Puguang region is known for containing sour fields with significant amount of H2S. Since 1975, sour service wells have been drilled entailing critical drilling conditions. To optimize drilling efficiency without sacrificing security, drill string improvements have been always looked for, by carefully evaluating steel grades, drill pipe sizes and connections.
The evolution of drilling programs has driven the industry to develop more suitable solutions adapted to extreme and aggressive conditions such as Sour Service environments. High strength drill pipe is often necessary to achieve deeper drilling performance, even when Sulfide Stress Cracking susceptibility is observed in minimal concentrations of H2S in partial pressures. Due to the astringency of the sour environment, particular precautions have to be defined to select and characterize an adapted Sour Service steel grade.
This paper presents the evolution of choices in drill string design from basic API grades and connections to adapt and proprietary steel grades resistant to H2S with a high mechanical performance properties and high torque double shoulder connections.
Maximize the Placement of Wells and Production in Unconventional Reservoirs:Part 1
Authors: Holdaway Keith R. 
Published: January 2012

Abstract
Over the past decade significant supplies of natural gas have been discovered in shale. While the development of new technologies has driven down the cost of gas extraction, pursuing natural gas in shale continues to be risky and capital-intensive.
Producers seek the most productive zones in their shale basins, as well as continued improvement in hydraulic fracturing processes. Decreasing costs and reducing risk while maximizing shale gas production necessitates innovative, advanced analytical capabilities that can give you a comprehensive understanding of the reservoir heterogeneity in order to extract hidden predictive information, identify drivers and leading indicators of efficient well production, determine the best intervals for stimulation, and recommend optimum stimulation processes and frequencies. Modeling, simulating and predicting well productivity requires integrated exploratory, predictive and forecasting capabilities underpinned by advanced analytical models to unlock the true potential of each wellbore. Without the critical insight enabled by integrated analysis to pair productivity analysis with economic feasibility, companies face significant risk and uncertainty when developing new wells or optimizing production of extant wellbores.
This paper walks through two case studies implemented in the Bakken and Pinedale assets in the United States, exemplifying data mining workflows that successfully improved hydrocarbon production.
Well Test Analysis of Infrequent Behavior of Fractured Wells in Oil and Gas Reservoirs
Authors: Amin A.. 
Published: January 2012

AbstractThe purpose of well stimulation is to increase the contact area of the wellbore in the reservoir to maximise production rates. This is achieved through fractures penetrating the reservoir. These fractures tend to show either infinite conductivity with double lines half slope or finite conductivity with quarter slope on the log-log plot of pressure change versus elapsed time depending on the permeability and other parameters of the formation. These flow behaviors are clear indications of a stimulated well. However, observations in some post frac tests where a single slope line is reported indicate non-fractured well response.The objective of this paper is to investigate the unusual flow behavior associated with fractured well tests following a proppant frac job. To author’s knowledge, this behavior has been referred to briefly in a limited number of publications with no clear explanation. The aim of this study is to address this problem in detail and suggest that this behavior is due to a variety of reasons assuming the frac job has targeted the reservoir interval of interest. The controlling factors are fracture lengths, fracture conductivity, the damage caused by the fracture operation including choke fracture effect and less importantly, fracture face skin and non-Darcy effect in the case of gas wells.The study utilizes 3-D numerical simulation black oil and compositional models comprising of single and multi- layered reservoirs. Study results show that the investigated problem is likely to be associated with damaged fractures of short lengths and low fracture conductivity values. Knowledge obtained from the study is applied to the analysis of well tests from actual fractured wells. The importance of this paper is that understanding the behavior of fractured wells is important to operator and service companies.
Efficient Coiled-Tubing Fracturing for Proppant-Placement Assurance and Contingency-Cost Mitigation
Authors: Surjaatmadja Jim B. , East Loyd E. 
Published: January 2012

Abstract
Combining production from multiple intervals within a well during completion has been used for many years. Many of these reservoirs required hydraulic-fracture stimulation, and a number of promising fracturing methods have been developed where several stages can be performed sequentially, provided there is some method used to isolate previously stimulated intervals.
One method claims high efficiency by using high-rate treatments and limited-entry perforating concepts. However, the promises proved to be elusive. Contingencies for early screenout, perforating gun missfires, and other equipment failures have often dramatically impacted completion efficiency. To guard against these failures, the proppant schedules were underdesigned or purposely overflushed, thus reducing the resulting fracture conductivity.
To achieve limited-entry diversion, high-treatment rates were used, which required a large amount of hydraulic horsepower onsite. Yet, even when efficiencies were achievable, production logging often showed that, at best, only 50% of the intended fracturing targets would actually produce at fracture-stimulated rates. Discovery of an important phenomenon was recently explained using computational fluid dynamics (CFD) simulation. It was found that the difference in the physical qualities of proppant and the carrying fluid cause the upper intervals to receive mostly proppant-free fluid.
Pinpoint-stimulation fracturing methods can allow all of the multiple intervals completed to be stimulated efficiently, such that all intervals received the designed proppant volumes one interval at a time. For the most effective of these methods, coiled tubing (CT) is used to hydrajet perforate intervals for individual fracturing treatments, and proppant plugs are used to isolate stimulated intervals while maximizing near-wellbore (NWB) conductivity. These methods do not require removing the CT from the well between treatments, so early screenouts can be remediated immediately with minimal impact.
A new entry in this class of fracturing that allows real-time, on-demand downhole proppant-schedule control can be combined with real-time fracture-mapping diagnostics to optimize stimulated reservoir volume (SRV) on-the-fly, when needed. A 15-stage completion in the Marcellus is used to demonstrate the process.
Optimized Steerable Motor Design Overcomes Drilling Challenges in the Fayetteville Shale Unconventional Play
Authors: Azizov Azar , Davila Wilfredo , Janwadkar Sandeep , Fabian John , Fortelney Ryan , Welch Bart 
Published: January 2012

Abstract
The US-land unconventional shale plays have initiated an exponential increase in the number of horizontal wells drilled and completed in the last decade. Maximizing well productivity and improving drilling efficiency has always been a major challenge. Well placement in the sweet spot and extended laterals help maximize productivity. Curve intervals drilled with higher dogleg severity (DLS) have a reduced vertical-section which maximizes the length of subsequent lateral section in the productive zone. Wells in US shale plays are usually drilled with a DLS of 10 to 14 °/100 ft, but achievinghigh DLS presents numerous drilling challenges: rotating a steerable motor with a high adjustable kick-off sub (AKO) angle could result in bottomhole assembly (BHA) fatigue failure and premature damage to bit; drilling in oriented (slide) mode limits weight transfer to the bit which may reduce the rate-of-penetration (ROP).
These challenges led to the development and successful testing of a new steerable optimized designmotor (ODM) with a short bit-to-bend (BTB) distance. In some cases, the ODM motor drilled all sections, including high-DLS curves, tangents and laterals with precise directional control and well placement with one BHA. The ODM has helped the operator to achieve higher DLS at lower AKO angle settings, enabled rotating the BHA in well profiles where previously used motors could be operated only in slidemode and maximized the length of curve interval drilled in rotary mode at higher RPMs. Drilling high- DLS curves increased the length of laterals, enabling additional recovery of gas. The new system significantly improved drilling performance with excellent directional control.
This paper will discuss the design, modeling and results of horizontal type wells drilled using the steerable ODM in the Fayetteville Shale unconventional play.
New Approach for the Prediction of Klinkenberg Permeability In Situ for Low Permeability Sandstone in Tight Gas Reservoir
Authors: Tadayoni Mehdi , Valadkhani Mina 
Published: January 2012

Abstract
Tight gas reservoirs show challenges to geologists to characterize because of their tendency to begenerally heterogeneous due to depositional and diagenetic processes. The value petrophysical properties are very valuable in static and dynamic reservoir modeling. This paper presents a prediction of Klinkenberg permeability by using artificial neural network, composite logs and core data in basin in western USA. The klinkenberg model approximates a linear relation between the measured gas permeability and the reciprocal absolute mean core pressure. This model has been a consistent basis for the development of methods computing the absolute liquid permeability of a core sample based on a single data point.
In tight gas reservoir with increasing in gas slippag ( klinkenberg effect) cause to decrease in pore-throat size and permeability parameters. In advanced there were some method to determine Klinkenberg permeability in situ which can be obtained by measuring just routine air permeability and Klinkenberg parameter such as byrnes in 1997 & 2003 but these ways intensively depend on core permeability, so it needs some core plugs and inevitably we have to spend much time and money.
The goal in this study was to research about relationship between core Klinkenberg permeability and composite logs (gamma ray, density, neutron and formation resistivity and so on) by using MLP & Back Propagation methods (Artificial neural network) to characterize the Klinkenberg permeabilityin situ in 3 different wells in 3 stages (training, validation and application) with suitable core calibration. For two wells there is very good core calibration and the R2 is more than 0.7 in training and application processes.
The importance of evaluation of tight gas reservoir with high heterogeneity by using artificial neural network and conventional logs is spending less capital or time and finally obtaining reliable Klinkenberg permeability in situ.