bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diosmetin Induces Human Osteoblastic Differentiation Through the Protein Kinase C/p38 and Extracellular Signal-Regulated Kinase 1/2 Pathway
Authors: Hsu Ya-Ling , Kuo Po-Lin 
Published: February 2008

Abstract
Introduction: The survival of osteoblasts is one of the determinants of the development of osteoporosis. This study is the first to investigate the osteoblastic differentiation induced by diosmetin, a flavonoid derivative, in osteoblastic cell lines MG-63, hFOB, and MC3T3-E1 and bone marrow stroma cell line M2-10B4.
Materials and Methods: Osteoblastic differentiation was determined by assaying alkaline phosphatase (ALP) activity and mineralization degree and measuring various osteoblast-related markers using ELISA. Expression and phosphorylation of Runt-related transcription factor 2 (Runx2), protein kinase Cδ (PKCδ), extracellular signal-regulated kinase (ERK), p38, and c-jun-N-terminal kinase (JNK) was assessed by immunoblot. Rac1 activity was determined by immunoprecipitation, and Runx2 activity was assessed by EMSA. Genetic inhibition was performed by small hairpin RNA plasmids or small interfering RNA (siRNA) transfection.
Results: Diosmetin exhibited an effect on osteoblastic maturation and differentiation by means of ALP activity, osteocalcin, osteopontin, and type I collagen production, as well as Runx2 upregulation. Induction of differentiation by diosmetin was associated with increased PKCδ phosphorylation and the activations of Rac1 and p38 and ERK1/2 kinases. Blocking PKCδ by siRNA inhibition significantly decreased osteoblastic differentiation by inhibiting Rac1 activation and subsequently attenuating the phosphorylation of p38 and ERK1/2. In addition, blocking p38 and ERK1/2 by siRNA transfection also suppressed diosmetin-induced cell differentiation.
Conclusions: In this study, we show that diosmetin induced osteoblastic differentiation through the PKCδ-Rac1-MEK3/6-p38 and PKCδ-Rac1-MEK1/2- ERK1/2-Runx2 pathways and that it is a promising agent for treating osteoporosis.
Black/White Differences in Very Low Birth Weight Neonatal Mortality Rates Among New York City Hospitals
Authors: Howell Elizabeth A. , Hebert Paul , Chatterjee Samprit , Kleinman Lawrence C. , Chassin Mark R. 
Published: February 2008

OBJECTIVE. We sought to determine whether differences in the hospitals at which black and white infants are born contribute to black/white disparities in very low birth weight neonatal mortality rates in New York City.
METHODS. We performed a population-based cohort study using New York City vital statistics records on all live births and deaths of infants weighing 500 to 1499 g who were born in 45 hospitals between January 1, 1996, and December 31, 2001 (N = 11 781). We measured very low birth weight risk-adjusted neonatal mortality rates for each New York City hospital and assessed differences in the distributions of non-Hispanic black and non-Hispanic white very low birth weight births among these hospitals.
RESULTS. Risk-adjusted neonatal mortality rates for very low birth weight infants in New York City hospitals ranged from 9.6 to 27.2 deaths per 1000 births. White very low birth weight infants were more likely to be born in the lowest mortality tertile of hospitals (49%), compared with black very low birth weight infants (29%). We estimated that, if black women delivered in the same hospitals as white women, then black very low birth weight mortality rates would be reduced by 6.7 deaths per 1000 very low birth weight births, removing 34.5% of the black/white disparity in very low birth weight neonatal mortality rates in New York City. Volume of very low birth weight deliveries was modestly associated with very low birth weight mortality rates but explained little of the racial disparity.
CONCLUSION. Black very low birth weight infants more likely to be born in New York City hospitals with higher risk-adjusted neonatal mortality rates than were very low birth weight infants, contributing substantially to black-white disparities.
Field testing of equilibrium passive samplers to determine freely dissolved native polycyclic aromatic hydrocarbon concentrations
Authors: Cornelissen Gerard , Pettersen Arne , Broman Dag , Mayer Philipp , Breedveld Gijs D 
Published: February 2008

Abstract
Equilibrium passive samplers are promising tools to determine freely dissolved aqueous concentrations (CW,free) of hydrophobic organic compounds. Their use in the field, however, remains a challenge. In the present study on native polycyclic aromatic hydrocarbons (PAHs) in Oslo Harbor, Norway, two different passive sampler materials, polyoxymethylene (POM; thickness, 55 μm [POM-55] and 500 μm [POM-500]) and polydimethylsiloxane (PDMS; thickness, 200 μm), were used to determine in the laboratory CW,free in sediment pore water (CPW,free), and the suitability of five passive samplers for determination of CW,free in overlying surface water was tested under field conditions. For laboratory determinations of CPW,free, both POM-55 and PDMS turned out to be suitable. In the field, the shortest equilibrium times (approximately one month) were observed for POM-55 and PDMS (thickness, 28 μm) coatings on solid-phase microextraction fibers, with PDMS tubing as a good alternative. Low-density polyethylene (thickness, 100 μm) and POM-500 did not reach equilibrium within 119 d in the field. Realistic values were obtained for dissolved organic carbon–water partition coefficients in the field (approximately one log unit under log KOW), which strengthened the conclusion that equilibrium was established in field-exposed passive samplers. At all four stations, chemical activity ratios between pore water and overlying water were greater than one for all PAHs, indicating that the sediment was a PAH diffusion source and that sediment remediation may be an appropriate treatment for PAH contamination in Oslo Harbor.
Using accelerated life testing procedures to compare the relative sensitivity of rainbow trout and the federally listed threatened bull trout to three commonly used rangeland herbicides (Picloram, 2,4-D, and clopyralid)
Authors: Fairchild James F , Allert Ann , Sappington Linda S , Nelson Karen J , Valle Janet 
Published: February 2008

Abstract
We conducted 96-h static acute toxicity studies to evaluate the relative sensitivity of juveniles of the threatened bull trout (Salvelinus confluentus) and the standard cold-water surrogate rainbow trout (Onchorhyncus mykiss) to three rangeland herbicides commonly used for controlling invasive weeds in the northwestern United States. Relative species sensitivity was compared using three procedures: standard acute toxicity testing, fractional estimates of lethal concentrations, and accelerated life testing chronic estimation procedures. The acutely lethal concentrations (ALC) resulting in 50% mortality at 96 h (96-h ALC50s) were determined using linear regression and indicated that the three herbicides were toxic in the order of picloram acid &gt; 2,4-D acid &gt; clopyralid acid. The 96-h ALC50 values for rainbow trout were as follows: picloram, 41 mg/L; 2.4-D, 707 mg/L; and clopyralid, 700 mg/L. The 96-h ALC50 values for bull trout were as follows: picloram, 24 mg/L; 2.4-D, 398 mg/L; and clopyralid, 802 mg/L. Fractional estimates of safe concentrations, based on 5% of the 96-h ALC50, were conservative (overestimated toxicity) of regression-derived 96-h ALC5 values by an order of magnitude. Accelerated life testing procedures were used to estimate chronic lethal concentrations (CLC) resulting in 1% mortality at 30 d (30-d CLC1) for the three herbicides: picloram (1 mg/L rainbow trout, 5 mg/L bull trout), 2,4-D (56 mg/L rainbow trout, 84 mg/L bull trout), and clopyralid (477 mg/L rainbow trout; 552 mg/L bull trout). Collectively, the results indicated that the standard surrogate rainbow trout is similar in sensitivity to bull trout. Accelerated life testing procedures provided cost-effective, statistically defensible methods for estimating safe chronic concentrations (30-d CLC1s) of herbicides from acute toxicity data because they use statistical models based on the entire mortality:concentration:time data matrix.
The Evaluation, Classification and Reporting of Unconventional Resources
Authors: Elliott David C. 
Published: February 2008

Abstract
The evaluation of unconventional resources presents many challenges, one of which is a need to evaluate all resource classes, not only Proved reserves. The evaluation of hydrocarbons is described as consisting of three steps: Estimation, Classification, and Reporting, with a concomitant requirement for auditing. The nature of estimates is discussed, in particular, that there is always an associated uncertainty and some fundamental principles of classification are reviewed. The classification of unconventional hydrocarbons is discussed, with an emphasis on Discovered Petroleum Initially-In-Place and Contingent Resources, which are formulated as a series of Decision rules. Information on production potential, either from tests or analogs, is of particular importance when classifying unconventional hydrocarbons, and the typical lack of defined pool boundaries requires that careful consideration be given to the area assigned to various resource categories, both of which points emphasise the need for an understanding of the detailed reservoir geology.
The Petroleum Resource Management System (PRMS), supplemented by the Canadian Oil and Gas Handbook (COGEH), has provided the basis for the discussion in this paper, but it is impossible in a short paper to capture these systems in full, and reference should be made to the original source documents for details. The emphasis in this paper is on recovery through wells, but some brief mention of mined hydrocarbon recovery is made. The exploitation of unconventional hydrocarbons is in its early stages, and evaluation procedures, including classification, are still under development. Many aspects of the evaluation process are not addressed in this paper, and those that are, are likely to require further development and modification.
Toward Production From Gas Hydrates: Current Status, Assessment of Resources, and Model-Based Evaluation of Technology and Potential
Authors: Moridis George J. , Collett Timothy S. , Boswell Ray , Kurihara M. , Reagan Matthew T. , Koh Carolyn , Sloan E. Dendy 
Published: February 2008

Abstract
Gas hydrates are a vast energy resource with global distribution in the permafrost and in the oceans. Even if conservative estimates are considered and only a small fraction is recoverable, the sheer size of the resource is so large that it demands evaluation as a potential energy source. In this review paper, we discuss the distribution of natural gas hydrate accumulations, the status of the primary international R&D programs, and the remaining science and technological challenges facing commercialization of production. After a brief examination of gas hydrate accumulations that are well characterized and appear to be models for future development and gas production, we analyze the role of numerical simulation in the assessment of the hydrate production potential, identify the data needs for reliable predictions, evaluate the status of knowledge with regard to these needs, discuss knowledge gaps and their impact, and reach the conclusion that the numerical simulation capabilities are quite advanced and that the related gaps are either not significant or are being addressed. We review the current body of literature relevant to potential productivity from different types of gas hydrate deposits, and determine that there are consistent indications of a large production potential at high rates over long periods from a wide variety of hydrate deposits. Finally, we identify (a) features, conditions, geology and techniques that are desirable in potential production targets, (b) methods to maximize production, and (c) some of the conditions and characteristics that render certain gas hydrate deposits undesirable for production.
Rock Typing — Keys to Understanding Productivity in Tight Gas Sands
Authors: Rushing J. A. , Newsham K. E. , Blasingame T. A. 
Published: February 2008

Abstract
This paper presents a work-flow process to describe and characterize tight gas sands. The ultimate objective of this work-flow is to provide a consistent methodology to systematically integrate both large-scale geologic elements and small-scale rock petrology with the physical rock properties for low-permeability sandstone reservoirs. To that end, our work-flow integrates multiple data evaluation techniques and multiple data scales using a core-based rock typing approach that is designed to capture rock properties characteristic of tight gas sands.
Fundamental to this process model are identification and comparison of three different rock types — depositional, petro-graphie, and hydraulic. These rock types are defined as:
Depositional — These are rock types that are derived from eore-based descriptions of genetic units which are defined as collections of rocks grouped according to similarities in composition, texture, sedimentary structure, and stratigraphic sequence as influenced by the depositional environment. These rock types represent original large-scale rock properties present at deposition. Petrographie — These are rock types which are also described within the context of the geological framework, but the rock type criteria are based on pore-scale, microscopic imaging of the current pore structure — as well as the rock texture and composition, clay mineralogy, and diagenesis. Hydraulic — These are rock types that are also defined at the pore scale, but in this case we define "hydraulic" rock types as those that quantify the physical flow and storage properties of the rock relative to the native fluid(s) — as controlled by the dimensions, geometry, and distribution of the current pore and pore throat structure.
Each rock type represents different physical and chemical processes affecting rock properties during the depositional and paragenetic cycles. Since most tight gas sands have been subjected to post-depositional diagenesis, a comparison of all three rock types will allow us to assess the impact of diagenesis on rock properties. If diagenesis is minor, the depositional environment (and depositional rock types) as well as the expected rock properties derived from those depositional conditions will be good predictors of rock quality. However, if the reservoir rock has been subjected to significant diagenesis, the original rock properties present at deposition will be quite different than the current properties. More specifically, use of the depositional environment and the associated rock types (in isolation) to guide field development activities may result in ineffective exploitation.
Tight Gas Surveillance and Characterization: Impact of Production Logging
Authors: McCracken Michael E. , Fitz Dale , Ryan Tom 
Published: February 2008

Abstract
In this paper, we discuss the importance of production logging in tight gas reservoirs due to the large number of commingled entries that are typically associated with tight gas wells. We discuss the challenges associated with obtaining high quality production log data in tight gas reservoirs and the subsequent production log interpretation. Along with addressing these challenges, some initial production logging results are presented that highlight the importance of geology. These results include: 1.) Most of a well's production comes from a few zones, 2.) Some observed production rates are substantially higher than anticipated based on matrix properties, and 3.) In a few cases, sands that can be locally correlated between wells may be associated with anomalously high production rates.
Impact of Stress Sensitive Permeability on Production Data Analysis
Authors: Archer Rosalind 
Published: February 2008

Abstract
The dependence of reservoir permeability and porosity on pressure can have a significant impact on well performance. This paper addresses this issue theoretically, via reservoir simulation, and via production data analysis type curves. This paper presents the single phase fluid flow equation for a slightly compressible fluid in a stress sensitive reservoir in a form which can be solved in Laplace space to generate profiles of well flow rate versus time (for constant bottomhole pressure production). This is achieved by writing the flow equation in terms of the derivatives of a function involving the sum of pressure and pressure-squared terms. Reservoir simulation results concur with the theoretical prediction that depletion in a stress sensitive reservoir will be slower than in a non-stress sensitive reservoir, however ultimate recovery in the simulation cases was not affected by stress sensitivity. p/z plots for stress sensitive reservoirs show volumetrics are unaffected by stress sensitivity. Analysis of simulated production data from stress sensitive reservoirs shows that drainage area is likely to be underestimated by this approach. Permeabilities predicted from analysis using standard type curves are lower than the permeability at initial reservoir pressure. The magnitude of the reduction in the interpreted permeability naturally depends on the magnitude of the stress sensitivity.
Importance of Fabric on the Production of Gas Shales
Authors: Bustin A. M. M. , Bustin R. M. , Cui X. 
Published: February 2008

Abstract
The heterogeneity and complexity of gas shales cause substantial and often inexplicable variability in the production histories of gas wells. A major factor contributing to this variability is the microfabric of the matrix and the fracture network of the reservoir. It is widely postulated, although not proven, that the gas production from shales is controlled principally by Darcy flow through the fracture system and the matrix is considered important principally for gas storage. In order to gain insight and test the relative importance of fracture spacing and matrix diffusion/flow on the production of gas shales, we have developed a 2-dimensional numerical simulation model, which considers the flow of gas through both the shale matrices and the fractures for varying fabrics utilising experimental data obtained from a variety of important gas shales. The results of initial, constant parameter, numerical simulations showed that for a wide range of relative fracture permeability, matrix permeability/diffusivity and fracture spacing, the productivity of a gas shale reservoir is dependent on matrix diffusion rates. The diffusion rates and stress dependent fracture permeability data when integrated into the numerical simulator can be tested against measured production histories leading to more accurate production forecasts of new reservoirs and optimisation of field design.
The Characteristic Flow Behavior of Low-Permeability Reservoir Systems
Authors: Blasingame T. A. 
Published: February 2008

Abstract
This paper considers the mechanisms and characteristic flow patterns of low permeability reservoir systems. In this paper we focus on the issue of low permeability in conjunction with reservoir heterogeneity (as these often go hand in hand). Generally speaking, we focus on the single-phase gas flow case as this is most relevant — and we avoid concerns related to multiphase flow.
Low permeability reservoir systems exhibit unique flow behavior for the following reasons:
Low permeability (which yields poor utilization of reservoir pressure), this is caused in part by: –Depositional issues: very small grains, mixed with detrital muds (clays).–Diagenetic issues: clay precipitation, massive cementation, pressure compaction, etc. Reservoir heterogeneity — dictated by deposition and post-deposition (diagenetic) events, including: –Vertical heterogeneity: layering, laminae, etc.–Lateral heterogeneity: medium to large scale geologic features (e.g., turbidite deposition, faults, etc.).–Differential diagenesis, including hydrocarbon generation and migration.
These characteristics lead us to the relatively simple observation that low permeability reservoirs are simply poor conductors offluids. As a matter of background, this work discusses the issues relevant to the origin of low (and ultra-low) permeability reservoirs, but our primary focus is flow at macro- and mega-scales (as would be observed at a well). An obvious comment at this point is that the reservoir permeability and the reservoir heterogeneity are fixed constants that we can not change. While true, we can change our mechanism for accessing the reservoir (i.e., the well) and we can change our development strategy to ensure optimal performance and recovery of a particular reservoir.
As for changing our access to the reservoir, we can utilize hydraulic fracture stimulation techniques to create a conductive pathway into the reservoir from the well. This is and will be implicit in the continued development of low and ultra-low permeability reservoirs — regardless of the well type (vertical or horizontal). In this work, our emphasis is to consider the relatively simple case of a single vertical well with a hydraulic fracture and the resulting flow behavior that this type of well will experience. It is our contention that the elliptical flow regime dominates reservoir performance in low/ultra-low permeability reservoirs, and we apply both analytical and numerical solutions to a typical field case to illustrate the validity of the elliptical flow regime.
Design and Life Cycle Considerations for Unconventional Reservoir Wells
Authors: Miskimins Jennifer L. 
Published: February 2008

Abstract
This paper provides an overview of design and life cycle considerations for certain unconventional reservoir wells. An overview of unconventional reservoir definitions is provided. Well design and life cycle considerations are addressed from three aspects including up-front reservoir development, initial well completion, and well life and long-term considerations.
Up-front reservoir development issues discussed include well spacing, well orientation, reservoir stress orientations, and tubular metallurgy. Initial well completion issues include maximum treatment pressures and rates, treatment diversion, treatment staging, flowback and clean-up, and dewatering needs. Well life and long-term discussions include liquid loading, corrosion, refracturing and associated fracture reorientation, and the cost of abandonment.
These design considerations are evaluated using case studies for five unconventional reservoir types including shale gas (Barnett shale), tight gas (Jonah Field), tight oil (Bakken play), coalbed methane (San Juan basin), and tight heavy oil (Lost Hills Field). In evaluating the life cycle and design of unconventional reservoir wells, "one size" definitely does not fit all and valuable knowledge and a shortening of the learning curve can be achieved for new developments by studying similar, more mature fields.