bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic analysis of substrate utilization by native and TNAP-, NPP1-, or PHOSPHO1-deficient matrix vesicles
Authors: Ciancaglini Pietro , Yadav Manisha C , Simão Ana Maria Sper , Narisawa Sonoko , Pizauro João Martins , Farquharson Colin , Hoylaerts Marc F , Millán José Luis 
Published: October 2009

AbstractDuring the process of endochondral bone formation, chondrocytes and osteoblasts mineralize their extracellular matrix by promoting the formation of hydroxyapatite seed crystals in the sheltered interior of membrane-limited matrix vesicles (MVs). Here, we have studied phosphosubstrate catalysis by osteoblast-derived MVs at physiologic pH, analyzing the hydrolysis of ATP, ADP, and PPi by isolated wild-type (WT) as well as TNAP-, NPP1- and PHOSPHO1-deficient MVs. Comparison of the catalytic efficiencies identified ATP as the main substrate hydrolyzed by WT MVs. The lack of TNAP had the most pronounced effect on the hydrolysis of all physiologic substrates. The lack of PHOSPHO1 affected ATP hydrolysis via a secondary reduction in the levels of TNAP in PHOSPHO1-deficient MVs. The lack of NPP1 did not significantly affect the kinetic parameters of hydrolysis when compared with WT MVs for any of the substrates. We conclude that TNAP is the enzyme that hydrolyzes both ATP and PPi in the MV compartment. NPP1 does not have a major role in PPi generation from ATP at the level of MVs, in contrast to its accepted role on the surface of the osteoblasts and chondrocytes, but rather acts as a phosphatase in the absence of TNAP. © 2010 American Society for Bone and Mineral Research
Processing of the NF-κB2 precursor p100 to p52 is critical for RANKL-induced osteoclast differentiation
Authors: Maruyama Toshimasa , Fukushima Hidefumi , Nakao Kayoko , Shin Masashi , Yasuda Hisataka , Weih Falk , Doi Takahiro , Aoki Kazuhiro , Alles Neil , Ohya Keiichi , Hosokawa Ryuji , Jimi Eijiro 
Published: October 2009

Abstract
Gene targeting of the p50 and p52 subunits of NF-κB has shown that NF-κB plays a critical role in osteoclast differentiation. However, the molecular mechanism by which NF-κB regulates osteoclast differentiation is still unclear. To address this issue, we analyzed alymphoplasia (aly/aly) mice in which the processing of p100 to p52 does not occur owing to an inactive form of NF-κB-inducing kinase (NIK). Aly/aly mice showed a mild osteopetrosis with significantly reduced osteoclast numbers. RANKL-induced osteoclastogenesis from bone marrow cells of aly/aly mice also was suppressed. RANKL still induced the degradation of IκBα and activated classical NF-κB, whereas processing of p100 to p52 was abolished by the aly/aly mutation. Moreover, RANKL-induced expression of NFATc1 was impaired in aly/aly bone marrow. Overexpression of constitutively active IKKα or p52 restored osteoclastogenesis in aly/aly cells. Finally, transfection of either wild-type p100, p100ΔGRR that cannot be processed to p52, or p52 into NF-κB2-deficient cells followed by RANKL treatment revealed a strong correlation between the number of osteoclasts induced by RANKL and the ratio of p52 to p100 expression. Our data provide a new finding for a previously unappreciated role for NF-κB in osteoclast differentiation. © 2010 American Society for Bone and Mineral Research
Age-dependence of femoral strength in white women and men
Authors: Keaveny Tony M , Kopperdahl David L , Melton L Joseph , Hoffmann Paul F , Amin Shreyasee , Riggs B Lawrence , Khosla Sundeep 
Published: October 2009

AbstractAlthough age-related variations in areal bone mineral density (aBMD) and the prevalence of osteoporosis have been well characterized, there is a paucity of data on femoral strength in the population. Addressing this issue, we used finite-element analysis of quantitative computed tomographic scans to assess femoral strength in an age-stratified cohort of 362 women and 317 men, aged 21 to 89 years, randomly sampled from the population of Rochester, MN, and compared femoral strength with femoral neck aBMD. Percent reductions over adulthood were much greater for femoral strength (55% in women, 39% in men) than for femoral neck aBMD (26% in women, 21% in men), an effect that was accentuated in women. Notable declines in strength started in the mid-40s for women and one decade later for men. At advanced age, most of the strength deficit for women compared with men was a result of this decade-earlier onset of strength loss for women, this factor being more important than sex-related differences in peak bone strength and annual rates of bone loss. For both sexes, the prevalence of “low femoral strength” (&lt;3000 N) was much higher than the prevalence of osteoporosis (femoral neck aBMD T-score of −2.5 or less). We conclude that age-related declines in femoral strength are much greater than suggested by age-related declines in femoral neck aBMD. Further, far more of the elderly may be at high risk of hip fracture because of low femoral strength than previously assumed based on the traditional classification of osteoporosis. © 2010 American Society for Bone and Mineral Research
Transfer, analysis, and reversion of the fibrous dysplasia cellular phenotype in human skeletal progenitors
Authors: Piersanti Stefania , Remoli Cristina , Saggio Isabella , Funari Alessia , Michienzi Stefano , Sacchetti Benedetto , Robey Pamela Gehron , Riminucci Mara , Bianco Paolo 
Published: October 2009

Abstract
Human skeletal progenitors were engineered to stably express R201C mutated, constitutively active Gsα using lentiviral vectors. Long-term transduced skeletal progenitors were characterized by an enhanced production of cAMP, indicating the transfer of the fundamental cellular phenotype caused by activating mutations of Gsα. Like skeletal progenitors isolated from natural fibrous dysplasia (FD) lesions, transduced cells could generate bone but not adipocytes or the hematopoietic microenvironment on in vivo transplantation. In vitro osteogenic differentiation was noted for the lack of mineral deposition, a blunted upregulation of osteocalcin, and enhanced upregulation of other osteogenic markers such as alkaline phosphatase (ALP) and bone sialoprotein (BSP) compared with controls. A very potent upregulation of RANKL expression was observed, which correlates with the pronounced osteoclastogenesis observed in FD lesions in vivo. Stable transduction resulted in a marked upregulation of selected phosphodiesterase (PDE) isoform mRNAs and a prominent increase in total PDE activity. This predicts an adaptive response in skeletal progenitors transduced with constitutively active, mutated Gsα. Indeed, like measurable cAMP levels, the differentiative responses of transduced skeletal progenitors were profoundly affected by inhibition of PDEs or lack thereof. Finally, using lentiviral vectors encoding short hairpin (sh) RNA interfering sequences, we demonstrated that selective silencing of the mutated allele is both feasible and effective in reverting the aberrant cAMP production brought about by the constitutively active Gsα and some of its effects on in vitro differentiation of skeletal progenitors. © 2010 American Society for Bone and Mineral Research
IL21R and PTH may underlie variation of femoral neck bone mineral density as revealed by a genome-wide association study
Authors: Guo Yan , Zhang Li-Shu , Yang Tie-Lin , Tian Qing , Xiong Dong-Hai , Pei Yu-Fang , Deng Hong-Wen 
Published: October 2009

Abstract
Bone mineral density (BMD) measured at the femoral neck (FN) is the most important risk phenotype for osteoporosis and has been used as a reference standard for describing osteoporosis. The specific genes influencing FN BMD remain largely unknown. To identify such genes, we first performed a genome-wide association (GWA) analysis for FN BMD in a discovery sample consisting of 983 unrelated white subjects. We then tested the top significant single-nucleotide polymorphisms (SNPs; 175 SNPs with p &lt; 5 × 10−4) for replication in a family-based sample of 2557 white subjects. Combing results from these two samples, we found that two genes, parathyroid hormone (PTH) and interleukin 21 receptor (IL21R), achieved consistent association results in both the discovery and replication samples. The PTH gene SNPs, rs9630182, rs2036417, and rs7125774, achieved p values of 1.10 × 10−4, 3.24 × 10−4, and 3.06 × 10−4, respectively, in the discovery sample; p values of 6.50 × 10−4, 5.08 × 10−3, and 5.68 × 10−3, respectively, in the replication sample; and combined p values of 3.98 × 10−7, 9.52 × 10−6, and 1.05 × 10−5, respectively, in the total sample. The IL21R gene SNPs, rs8057551, rs8061992, and rs7199138, achieved p values of 1.51 × 10−4, 1.53 × 10−4, and 3.88 × 10−4, respectively, in the discovery sample; p values of 2.36 × 10−3, 6.74 × 10−3, and 6.41 × 10−3, respectively, in the replication sample; and combined p values of 2.31 × 10−6, 8.62 × 10−6, and 1.41 × 10−5, respectively, in the total sample. The effect size of each SNP was approximately 0.11 SD estimated in the discovery sample. PTH and IL21R both have potential biologic functions important to bone metabolism. Overall, our findings provide some new clues to the understanding of the genetic architecture of osteoporosis. © 2010 American Society for Bone and Mineral Research
Development and Field Application of a Low-pH, Efficient Fracturing Fluid for Tight Gas Fields in the Greater Green River Basin, Wyoming
Authors: Gupta D. V. S. , Jackson T. L. , Hlavinka G. J. , Evans J. B. , Le H. V. , Batrashkin A. , Shaefer M. T. 
Published: October 2009

Summary
Hydraulic fracturing has proved to be one of the best technologies to improve productivity from tight gas wells. In such low-permeability reservoirs, careful consideration must be given to fracturing fluid selection. Some reservoirs are underpressured and require the use of energized fluids, while others are sensitive to water-based fluids because of clay swelling and migration.
Proppant pack damage because of gel residue is one of the primary causes of low production rates after hydraulic fracturing treatments. To minimize the damage and maximize production, a new premium, highly efficient fracturing fluid was developed. This premium system incorporates low-polymer-loading carboxymethyl guar polymer and a zirconium-based crosslinker. An adjustable crosslink delay makes the fluid ideal for deep-well fracturing and coiled-tubing treatment as frictional pressure losses can be minimized. The system can be energized or foamed with carbon dioxide (CO2) and nitrogen (N2) or may also be used in binary foam systems.
This paper will provide details on the new fracturing fluid system, in terms of proppant pack cleanup, rheological properties, and fluid loss, as well as other parameters. Various rheological evaluations using high-pressure, high-temperature rheometers as well as a foam loop, fluid leakoff testing, proppant pack conductivity, and regain permeability evaluations are presented.
Field case histories will evaluate fracturing treatments using new fracturing fluid and comparable treatments using conventional fluid. Normalized production data of the treated wells of both systems are also compared.
Under-Rig-Floor Openhole Logging in the Gulf of Thailand: Operational Implementation of the Oil Industry's First Simultaneous Openhole Wireline Logging and Drilling Operation
Authors: Upchurch Eric R. , Laoamornpanich Thaveesub 
Published: October 2009

Summary
Chevron Thailand, on average, drills 12,000-ft measured-depth/8,200-ft total vertical depth wells in approximately 4.5 days. The factor that contributes most to this level of performance is the "offlining" of as many drilling-rig activities as possible. In our drilling operation, almost all pipe-handling and cementing operations are performed offline (i.e., off the critical-operations path and therefore simultaneous to other activities on the rig). We have now taken the next logical step in performing offline operations. In May 2007, Chevron Thailand introduced the world's first simultaneous openhole wireline logging and drilling operation on Seadrill RT-7 (a tender-assist drilling rig) and currently is deploying the same system on additional tender-assist rigs (TARs) and jackup rigs.
This paper is the second in a series of two that describe the engineering design and operational implementation of the tools and techniques necessary to make offline openhole wireline logging a reality. The first paper (Upchurch and Graves 2008) in this series details the engineering design aspects, and the resultant benefits, of this paradigm-changing logging system. This second paper describes the processes that were used to implement the system, along with the inherent risks and benefits of each phase of the implementation. Implementing radically new processes such as this into pre-existing drilling systems significantly increases the risk for technical failure, well control incidents, and personnel injury. This paper details the processes that were developed for avoiding all three. In the case of this new technology, our phased approach to implementation has resulted in smooth, incident-free introductions to the various rigsites. The benefits of this new system, and our method for implementing it without incident, are paying significant dividends to Chevron Thailand.
Vertical Mergers and Competition with a Regulated Bottleneck Monopoly
Authors: Galetovic Alexander , Sanhueza Ricardo 
Published: October 2009

Abstract
Consider a bottleneck monopoly whose access charge is regulated above marginal cost and produces an essential input used by an oligopoly of downstream firms. Should the monopolist be allowed to vertically integrate into the downstream market? Policy makers often argue that the vertically integrated subsidiary enjoys an undue advantage, because it receives access at marginal cost. We show that there is no undue advantage.With perfect competition downstream vertical integration is irrelevant because the subsidiary substitutes downstream output one-to-one and faces a per-unit opportunity cost equal to the access charge.With an oligopoly consumers and the bottleneck monopoly gain with vertical integration. By contrast, competitors lose oligopolistic rents. Social welfare increases, unless output is redistributed towards a very inefficient vertically integrated firm.
GAD Antibody Positivity Predicts Type 2 Diabetes in an Adult Population
Authors: Lundgren Virve M. , Isomaa Bo , Lyssenko Valeriya , Laurila Esa , Korhonen Pasi , Groop Leif C. , Tuomi Tiinamaija ,   for the Botnia Study Group
Published: October 2009

OBJECTIVE
To evaluate the significance of GAD antibodies (GADAs) and family history for type 1 diabetes (FHT1) or type 2 diabetes (FHT2) in nondiabetic subjects.

RESEARCH DESIGN AND METHODS
GADAs were analyzed in 4,976 nondiabetic relatives of type 2 diabetic patients or control subjects from Finland. Altogether, 289 (5.9%) were GADA+—a total of 253 GADA+ and 2,511 GADA− subjects participated in repeated oral glucose tolerance tests during a median time of 8.1 years. The risk of progression to diabetes was assessed using Cox regression analysis.

RESULTS
Subjects within the highest quartile of GADA+ (GADA+high) had more often first-degree FHT1 (29.2 vs. 7.9%, P &lt; 0.00001) and GADA+ type 2 diabetic (21.3 vs. 13.7%, P = 0.002) or nondiabetic (26.4 vs. 13.3%, P = 0.010) relatives than GADA− subjects. During the follow-up, the GADA+ subjects developed diabetes significantly more often than the GADA− subjects (36/253 [14.2%] vs. 134/2,511 [5.3%], P &lt; 0.00001). GADA+high conferred a 4.9-fold increased risk of diabetes (95% CI 2.8–8.5) compared with GADA−—seroconversion to positive during the follow-up was associated with 6.5-fold (2.8–15.2) and first-degree FHT1 with 2.2-fold (1.2–4.1) risk of diabetes. Only three subjects developed type 1 diabetes, and others had a non–insulin-dependent phenotype 1 year after diagnosis. GADA+ and GADA− subjects did not clinically differ at baseline, but they were leaner and less insulin resistant after the diagnosis of diabetes.

CONCLUSIONS
GADA positivity clusters in families with type 1 diabetes or latent autoimmune diabetes in adults. GADA positivity predicts diabetes independently of family history of diabetes, and this risk was further increased with high GADA concentrations.
Association of A1C and Fasting Plasma Glucose Levels With Diabetic Retinopathy Prevalence in the U.S. Population
Authors: Cheng Yiling J. , Gregg Edward W. , Geiss Linda S. , Imperatore Giuseppina , Williams Desmond E. , Zhang Xinzhi , Albright Ann L. , Cowie Catherine C. , Klein Ronald , Saaddine Jinan B. 
Published: October 2009

OBJECTIVE
To examine the association of A1C levels and fasting plasma glucose (FPG) with diabetic retinopathy in the U.S. population and to compare the ability of the two glycemic measures to discriminate between people with and without retinopathy.

RESEARCH DESIGN AND METHODS
This study included 1,066 individuals aged ≥40 years from the 2005–2006 National Health and Nutrition Examination Survey. A1C, FPG, and 45° color digital retinal images were assessed. Retinopathy was defined as a level ≥14 on the Early Treatment Diabetic Retinopathy Study severity scale. We used joinpoint regression to identify linear inflections of prevalence of retinopathy in the association between A1C and FPG.

RESULTS
The overall prevalence of retinopathy was 11%, which is appreciably lower than the prevalence in people with diagnosed diabetes (36%). There was a sharp increase in retinopathy prevalence in those with A1C ≥5.5% or FPG ≥5.8 mmol/l. After excluding 144 people using hypoglycemic medication, the change points for the greatest increase in retinopathy prevalence were A1C 5.5% and FPG 7.0 mmol/l. The coefficients of variation were 15.6 for A1C and 28.8 for FPG. Based on the areas under the receiver operating characteristic curves, A1C was a stronger discriminator of retinopathy (0.71 [95% CI 0.66–0.76]) than FPG (0.65 [0.60 – 0.70], P for difference = 0.009).

CONCLUSIONS
The steepest increase in retinopathy prevalence occurs among individuals with A1C ≥5.5% and FPG ≥5.8 mmol/l. A1C discriminates prevalence of retinopathy better than FPG.
Nonpharmacologic Therapy and Exercise in the Prevention of Type 2 Diabetes
Authors: Tuomilehto Jaakko 
Published: October 2009

OBJECTIVE
To review the current knowledge about nonpharmacologic approaches in the prevention and early treatment of type 2 diabetes.

RESEARCH DESIGN AND METHODS
This study reviewed the research reports dealing with nonpharmacologic interventions aimed at preventing type 2 diabetes with early lifestyle interventions.

RESULTS
The results from the randomized controlled trials all show that people with impaired glucose tolerance who received enhanced lifestyle advice had significantly lower (on average ∼50% reduced) incidence of type 2 diabetes compared with those allocated to receive “usual care.” Individuals who were able to correct their lifestyle habits as recommended for usual healthy life patterns were mostly protected against type 2 diabetes. Thus, compelling evidence exists that most of the cases of type 2 diabetes can be prevented or at least the onset of the disease can be significantly delayed.

CONCLUSIONS
Randomized controlled trials have unequivocally demonstrated that lifestyle management is highly efficient in the prevention and also in the early management of type 2 diabetes. This evidence of lifestyle modification in diabetes prevention is stronger than for most other multifactorial diseases.
Stanley depth of monomial ideals with small number of generators
Authors: Cimpoeaş Mircea 
Published: October 2009

Abstract
For a monomial ideal I ⊂ S = K[x
1...,x
n], we show that sdepth(S/I) ≥ n − g(I), where g(I) is the number of the minimal monomial generators of I. If I =νI′, where ν ∈ S is a monomial, then we see that sdepth(S/I) = sdepth(S/I′). We prove that if I is a monomial ideal I ⊂ S minimally generated by three monomials, then I and S/I satisfy the Stanley conjecture. Given a saturated monomial ideal I ⊂ K[x
1,x
2,x
3] we show that sdepth(I) = 2. As a consequence, sdepth(I) ≥ sdepth(K[x
1,x
2,x
3]//I) +1 for any monomial ideal in I ⊂ K[x
1,x
2,x
3].
Permutations which make transitive groups primitive
Authors: Lopes Pedro 
Published: October 2009

Abstract
In this article we look into characterizing primitive groups in the following way. Given a primitive group we single out a subset of its generators such that these generators alone (the so-called primitive generators) imply the group is primitive. The remaining generators ensure transitivity or comply with specific features of the group.
We show that, other than the symmetric and alternating groups, there are infinitely many primitive groups with one primitive generator each. These primitive groups are certain Mathieu groups, certain projective general and projective special linear groups, and certain subgroups of some affine special linear groups.
Unboundedness results for systems
Authors: Lugo Gabriel , Palladino Frank 
Published: October 2009

Abstract
We study k
th order systems of two rational difference equations $$
x_n = \frac{{\alpha + \sum\nolimits_{i = 1}^k {\beta _i x_{n - i} + } \sum\nolimits_{i = 1}^k {\gamma _i y_{n - i} } }}
{{A + \sum\nolimits_{j = 1}^k {B_j x_{n - j} + } \sum\nolimits_{j = 1}^k {C_j y_{n - j} } }},n \in \mathbb{N},
$$ In particular we assume non-negative parameters and non-negative initial conditions. We develop several approaches which allow us to prove that unbounded solutions exist for certain initial conditions in a range of the parameters.
Bernstein sets with algebraic properties
Authors: Kysiak Marcin 
Published: October 2009

Abstract
We construct Bernstein sets in ℝ having some additional algebraic properties. In particular, solving a problem of Kraszewski, Rałowski, Szczepaniak and Żeberski, we construct a Bernstein set which is a < c-covering and improve some other results of Rałowski, Szczepaniak and Żeberski on nonmeasurable sets.
On bounded nonoscillatory solutions of third-order nonlinear differential equations
Authors: Mojsej Ivan , Tartaľová Alena 
Published: October 2009

Abstract
This paper is concerned with the asymptotic behavior of solutions of nonlinear differential equations of the third-order with quasiderivatives. We give the necessary and sufficient conditions guaranteeing the existence of bounded nonoscillatory solutions. Sufficient conditions are proved via a topological approach based on the Banach fixed point theorem.