bluuebunny/crossref_metadata_2025_split huggingface dataset:
Egg Size Variation in Lake Trout: Phenotype–Habitat Correlations Show an Effect of Rearing Environment
Authors: Jastrebski C. J. , Morbey Y. E. 
Published: October 2009

AbstractOur objective was to evaluate how different lake environments (Laurentian Great Lakes versus inland lakes) and hatchery rearing influence egg traits in lake trout Salvelinus namaycush. Lake trout eggs were collected from 11 hatchery populations and 15 wild populations in the vicinity of the Great Lakes. Average egg size (controlling for body size) differed among populations but not between hatchery and wild populations or Great Lakes and inland lake populations. However, within‐female egg size variability was consistently higher in hatchery populations than in wild populations and, to a lesser extent, in Great Lakes populations than in inland populations. We hypothesize that these effects are due to confinement (hatchery)‐ and habitat (lake environment)‐mediated stress affecting oogenesis.
Influence of Rare Species on Electrofishing Distance When Estimating Species Richness of Stream and River Reaches
Authors: Kanno Yoichiro , Vokoun Jason C. , Dauwalter Daniel C. , Hughes Robert M. , Herlihy Alan T. , Maret Terry R. , Patton Tim M. 
Published: October 2009

AbstractThe electrofishing distance needed to estimate fish species richness at the stream or river reach scale is an important question in fisheries science. This distance is governed by the shape of the species accumulation curve, which, in turn, is influenced by a combination of factors, including the number of species, their overall abundances, habitat associations, the efficiency of the sampling method, and the occurrence of rare species. In this study we document the influence of rare species on the species accumulation curves from stream and river sites in data sets from five dispersed regions of the USA. Spatial discontinuity (i.e., a noncontinuous distribution within reaches) was observed in four of the five data sets, and the four data sets contained numerically rare species represented by one or two individuals (termed singletons and doubletons, respectively). Numerically rare species were typically proportionately rare (i.e., <1% of the total number of individuals captured), but proportionately rare species were not always numerically rare and were dependent on the total number of fish captured. Species richness asymptotes were reached at shorter electrofishing distances when singletons and doubletons were removed. The number of singletons and doubletons in the samples remained relatively constant with increasing sampling effort (i.e., sampling distance and total abundance). Simulation modeling indicated that individual aggregation within species was not a plausible reason for spatially discontinuous species distributions. When accurately detecting the presence of species is a sampling goal, the presence and prevalence of numerically rare species may need to be considered in determining sampling protocols.
Effect of Water Hardness and Dissolved‐Solid Concentration on Hatching Success and Egg Size in Bighead Carp
Authors: Chapman Duane C. , Deters Joseph E. 
Published: October 2009

AbstractBighead carp Hypophthalmichthys nobilis is an Asian species that has been introduced to the United States and is regarded as a highly undesirable invader. Soft water has been said to cause the bursting of Asian carp eggs and thus has been suggested as a factor that would limit the spread of this species. To evaluate this, we subjected fertilized eggs of bighead carp to waters with a wide range of hardness and dissolved‐solid concentrations. Hatching rate and egg size were not significantly affected by the different water qualities. These results, combined with the low hardness (28–84 mg/L) of the Yangtze River (the primary natal habitat of Hypophthalmichthys spp.), suggest that managers and those performing risk assessments for the establishment of Hypophthalmichthys spp. should be cautious about treating low hardness and dissolved‐solid concentrations as limiting factors.
Race and Unhealthy Behaviors: Chronic Stress, the HPA Axis, and Physical and Mental Health Disparities Over the Life Course
Authors: Jackson James S. , Knight Katherine M. , Rafferty Jane A. 
Published: October 2009

Objectives. We sought to determine whether unhealthy behaviors play a stress-buffering role in observed racial disparities in physical and mental health. Methods. We conducted logistic regressions by race on data from the first 2 waves of the Americans' Changing Lives Survey to determine whether unhealthy behaviors had buffering effects on the relationship between major stressors and chronic health conditions, and on the relationship between major stressors and meeting the criteria for major depression. Results. Among Whites, unhealthy behaviors strengthened the relationship between stressors and meeting major-depression criteria. Among Blacks, however, the relationship between stressors and meeting major-depression criteria was stronger among those who had not engaged in unhealthy behaviors than among those who had. Among both race groups there was a positive association between stressors and chronic health conditions. Among Blacks there was an additional positive association between number of unhealthy behaviors and number of chronic conditions. Conclusions. Those who live in chronically stressful environments often cope with stressors by engaging in unhealthy behaviors that may have protective mental-health effects. However, such unhealthy behaviors can combine with negative environmental conditions to eventually contribute to morbidity and mortality disparities among social groups.
Improving Injectivity To Fight Gravity Segregation in Gas Enhanced Oil Recovery
Authors: Jamshidnezhad M.. , Shen C.. , Kool P.. , Mojaddam Zadeh A.. , Rossen W.R.. R. 
Published: October 2009

Summary
Models for gravity segregation in gas enhanced oil recovery (EOR) indicate that the distance injected gas and water travel together before complete segregation scales with the injection rate Q. Therefore, in cases where injection pressure is limiting, increasing injectivity can improve sweep efficiency. We examine several strategies. Reducing skin resulting from damage at the wellbore face directly increases volumetric sweep of gas. Even in the absence of damage at the wellbore face, most of the injection pressure is dissipated near the injection well, but most of segregation of gas and water occurs much further from the well. Therefore, if injection pressure is limited, increasing mobility near the injection well has a large impact on Q, with a direct benefit in delaying gravity segregation. There is also a relatively small increase in gravity segregation in the near-well region. An analytical model for gravity segregation in homogeneous reservoirs can be extended to a case where permeability is stimulated within a cylindrical region inside a larger cylindrical reservoir. The effect of this stimulation in increasing Q at fixed injection pressure can be estimated as well. One can increase the volume swept by gas before segregation by as much as 170%, though a large volume must be stimulated to reach this optimum.
The model represents schematically a number of ways proposed in gas EOR for delaying segregation beyond the possibilities with uniform, steady coinjection of Newtonian fluids: alternate injection of gas and liquid [water alternating gas (WAG) or surfactant alternating gas (SAG) with foam]; injection of gas above water; and injection of shear-thinning foam. In all these cases, the process gives higher mobility near the well, allowing an increase in injection rate, and thereby increases the distance to the point of segregation.
The model can be extended directly to the case of shear-thinning (power-law) foam. One obtains a differential equation for the segregation process, in place of the algebraic equation that results for Newtonian fluids. In the limit of extremely shear-thinning behavior, it is possible to double the distance to the point of segregation with no increase in injection pressure. The model can also be applied to foams that are shear-thinning only at high superficial velocity (i.e., near the well). Simulations fit the theoretical prediction well.
Modeling of an Underbalanced-Drilling Operation Using Supercritical Carbon Dioxide
Authors: Al-Adwani Faisal , Langlinais Julius , Hughes Richard 
Published: October 2009

Abstract
A mechanistic model of an underbalanced-drilling (UBD) operation using carbon dioxide (CO2) is developed in this study. The use of carbon dioxide in UBD operations eliminates some of the operational difficulties inherent with gaseous drilling fluids, such as generating enough torque to run a downhole motor. The unique properties of CO2, both inside the drillpipe and in the annulus, are shown in terms of optimizing the drilling operation by achieving a low bottomhole pressure range. Typically, CO2 becomes supercritical inside the drillpipe at this high density; thus, it can generate enough torque to run a downhole motor. As the fluid exits the drill bit, it evaporates to a gas, hence achieving the required low density for UBD. The latest CO2 equation of state (EOS) to calculate the required thermodynamic fluid properties is used. In addition, a heat-transfer model that takes into account varying properties of both pressure and temperature has been developed. A marching algorithm procedure is developed to calculate the circulating fluid pressure and temperature, taking into account the varying parameters. Both single-phase CO2 and a mixture of CO2 and water have been studied to show the effect of produced water on corrosion rates. The model also is capable of handling different drillpipe and annular geometries.
Use of Dynamic Simulation To Assist Commissioning and Operating a 65-km-Subsea-Tieback Gas Lift System
Authors: Salman Yaser , Wittfeld Chad , Lee Adrian , Yick Chevy , Derkinderen Wim 
Published: October 2009

Summary
The Penguins field comprises of a cluster of reservoirs in the northern North Sea. The need for gas lift was foreseen during the early stages of field-development planning. Five oil wells were completed for gas lift service. A 65-km 4-in. gas lift line was laid in 2006, running alongside the production line and tied into the drill centers by flexible 2-in. jumpers.
Because of the unconventionally long distance of the field from the platform, it was necessary to carry out transient modeling of the full commissioning and gas lift startup process. Particular attention was required, both in design and operating procedure, to avoid hydrates and excessive velocities in the high-pressure, low-temperature system.
Dynamic simulation with the industry-renowned transient software package (OLGA v5.1 2006) has proved to be valuable for the commissioning of this gas lift system. It also explained discrepancies between anticipated behavior of the shear orifice valve and the actual behavior seen in the field.
The overall project outcome was a success, with excellent improvements in field stability and production. The project was justified on the basis of kickoff capability only, but continuous gas lift is required to maintain stable flow from all of the wells.
Resolving Created, Propped, and Effective Hydraulic-Fracture Length
Authors: Cipolla C. L. , Lolon E. P. , Mayerhofer M. J. 
Published: October 2009

Summary
Recent advances in hydraulic-fracture-mapping technologies have provided a wealth of information on the created fracture length in numerous geologic settings. Before having such measurements, fracture length was estimated using "uncalibrated" fracture-propagation models, but there was significant uncertainty in the results that cascaded into subsequent production analyses. However, we also need to understand how the created fracture length relates to the location of proppant in the fracture and to the producing or effective length to evaluate well performance and improve stimulation designs. Unfortunately, the advanced fracture-mapping technologies that provide accurate measurements of the created fracture length cannot provide any insights (yet) into the propped and effective fracture lengths. Advanced production-data analyses (PDAs), pressure-transient testing, and/or numerical reservoir modeling are required to determine the effective fracture length.
This paper begins with a comparison of the strengths, weaknesses, and limitations of fracture modeling, PDA, pressure-transient analysis (PTA), and numerical reservoir modeling to estimate effective fracture length and conductivity. This work also evaluates how the complexities (in the hydraulic fracture) associated with non-Darcy flow, multiphase flow, and complex fracture geometries affect the results from the various techniques. This work documents the significant differences in "effective" fracture length that, in many cases, can result from each technique and how these uncertainties can impact fracture treatment designs and field-development decisions.
The paper concludes with several field case histories that illustrate the integration of multiple technologies to determine the created, propped, and effective fracture length. The case histories illustrate the dramatic differences in created and effective fracture length that can occur in some reservoirs, while also showing that in some cases, effective fracture lengths can be very similar to the created length (and quite long). Integrating the results from multiple diagnostic techniques in a consistent and coherent manner can provide significant insights into created, propped, and effective fracture length that are otherwise unattainable from each technique alone.
Association of Metformin, Elevated Homocysteine, and Methylmalonic Acid Levels and Clinically Worsened Diabetic Peripheral Neuropathy
Authors: Wile Daryl J. , Toth Cory 
Published: October 2009

OBJECTIVE
The severity of peripheral neuropathy in diabetic patients varies for unclear reasons. Long-term use of metformin is associated with malabsorption of vitamin B12 (cobalamin [Cbl]) and elevated homocysteine (Hcy) and methylmalonic acid (MMA) levels, which may have deleterious effects on peripheral nerves. The intent of this study was to clarify the relationship among metformin exposure, levels of Cbl, Hcy, and MMA, and severity of peripheral neuropathy in diabetic patients. We hypothesized that metformin exposure would be associated with lower Cbl levels, elevated Hcy and MMA levels, and more severe peripheral neuropathy.

RESEARCH DESIGN AND METHODS
This was a prospective case-control study of patients with type 2 diabetes and concurrent symptomatic peripheral neuropathy, comparing those who had received &gt;6 months of metformin therapy (n = 59) with those without metformin exposure (n = 63). Comparisons were made using clinical (Toronto Clinical Scoring System and Neuropathy Impairment Score), laboratory (serum Cbl, fasting Hcy, and fasting MMA), and electrophysiological measures (nerve conduction studies).

RESULTS
Metformin-treated patients had depressed Cbl levels and elevated fasting MMA and Hcy levels. Clinical and electrophysiological measures identified more severe peripheral neuropathy in these patients; the cumulative metformin dose correlated strongly with these clinical and paraclinical group differences.

CONCLUSIONS
Metformin exposure may be an iatrogenic cause for exacerbation of peripheral neuropathy in patients with type 2 diabetes. Interval screening for Cbl deficiency and systemic Cbl therapy should be considered upon initiation of, as well as during, metformin therapy to detect potential secondary causes of worsening peripheral neuropathy.
Effects of Long-Term Fenofibrate Treatment on Markers of Renal Function in Type 2 Diabetes
Authors: Forsblom Carol , Hiukka Anne , Leinonen Eeva S. , Sundvall Jouko , Groop Per-Henrik , Taskinen Marja-Riitta 
Published: October 2009

OBJECTIVE
Although fenofibrate was associated with less progression of albuminuria in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study, it is unknown if it has any effect on renal function. We explored if there were changes in commonly available markers of renal function during fenofibrate treatment in the FIELD Helsinki cohort excluding statin users.

RESEARCH DESIGN AND METHODS
One hundred and seventy subjects with type 2 diabetes were randomly assigned to micronized fenofibrate (200 mg/day) or placebo for 5 years. In this substudy, we measured several markers of albumin excretion and renal function.

RESULTS
After intensified treatment, blood pressure and fasting glucose decreased in both groups while A1C remained at 7.2%. Plasma creatinine increased with fenofibrate while urine creatinine remained comparable between the groups, resulting in significant decreases in both creatinine clearance and estimated glomerular filtration rate (eGFR) by the Modification of Diet in Renal Disease (MDRD)-4 and Cockroft-Gault equations in the fenofibrate group. Cystatin C increased during fenofibrate treatment. Urinary albumin-to-creatinine ratio and diurnal urine protein remained unchanged, whereas overnight urinary albumin excretion rate showed minor decreases in both groups.

CONCLUSIONS
We report concomitant decreases in creatinine clearance and eGFR by fenofibrate. These changes complicate the clinical surveillance during fenofibrate treatment. We could not demonstrate the beneficial effects of fenofibrate on albumin excretion. A novel finding is the increase of cystatin C in type 2 diabetic patients during fenofibrate treatment. The clinical relevance of the changes needs to be assessed in a long-term outcome study of renal function.
Associations of Serum Concentrations of 25-Hydroxyvitamin D and Parathyroid Hormone With Surrogate Markers of Insulin Resistance Among U.S. Adults Without Physician-Diagnosed Diabetes: NHANES, 2003–2006
Authors: Zhao Guixiang , Ford Earl S. , Li Chaoyang 
Published: October 2009

OBJECTIVETo examine whether concentrations of serum 25-hydroxyvitamin D (25[OH]D) and parathyroid hormone (PTH) are associated with surrogate markers of insulin resistance (IR) in U.S. adults without physician-diagnosed diabetes.RESEARCH DESIGN AND METHODSCross-sectional data (n = 3,206) from the National Health and Nutrition Examination Survey (NHANES) 2003–2006 were analyzed.RESULTSThe age-adjusted prevalence of hyperinsulinemia, high homeostasis model assessment-IR, high GHb, and fasting and 2-h hyperglycemia decreased linearly across quintiles of 25(OH)D but increased linearly across quintiles of PTH (except for a quadratic trend for fasting hyperglycemia). After extensive adjustment for potential confounders, the relationships between 25(OH)D and the markers of IR and 2-h hyperglycemia persisted. Only hyperinsulinemia was positively associated with PTH (P &lt; 0.05).CONCLUSIONSAmong U.S. adults without physician-diagnosed diabetes, low concentrations of serum 25(OH)D were associated with markers of IR. The role of PTH in IR deserves further investigation.
Glycated Albumin and Glycated Hemoglobin Are Influenced Differently by Endogenous Insulin Secretion in Patients With Type 2 Diabetes
Authors: Koga Masafumi , Murai Jun , Saito Hiroshi , Kasayama Soji 
Published: October 2009

OBJECTIVE
Glycated albumin (GA) relative to A1C is a useful marker of short-term glycemic control. We investigated whether endogenous insulin secretion in type 2 diabetes has different effects on GA and A1C levels.

RESEARCH DESIGN AND METHODS
A1C, GA, and GA-to-A1C ratio were compared in 202 type 2 diabetic patients by type of treatment. Effect of β-cell function determined by homeostasis model assessment (HOMA-%β) on GA-to-A1C ratio was examined. In addition, GA-to-A1C ratio was compared between type 2 diabetic patients and 16 patients with type 1 diabetes.

RESULTS
In type 2 diabetic patients, GA-to-A1C ratio was significantly higher in those treated with insulin than in those treated with diet or oral hypoglycemic agents. HOMA-%β showed a significant inverse correlation with GA-to-A1C ratio. This ratio was higher in type 1 diabetic patients than in type 2 diabetic patients.

CONCLUSIONS
In diabetic patients with decreased insulin secretion, serum GA levels are higher relative to A1C.
Closed-Loop Insulin Delivery Using a Subcutaneous Glucose Sensor and Intraperitoneal Insulin Delivery
Authors: Renard Eric , Place Jerome , Cantwell Martin , Chevassus Hugues , Palerm Cesar C. 
Published: October 2009

OBJECTIVE
Attempts to build an artificial pancreas by using subcutaneous insulin delivery from a portable pump guided by an subcutaneous glucose sensor have encountered delays and variability of insulin absorption. We tested closed-loop intraperitoneal insulin infusion from an implanted pump driven by an subcutaneous glucose sensor via a proportional-integral-derivative (PID) algorithm.

RESEARCH DESIGN AND METHODS
Two-day closed-loop therapy (except for a 15-min premeal manual bolus) was compared with a 1-day control phase with intraperitoneal open-loop insulin delivery, according to randomized order, in a hospital setting in eight type 1 diabetic patients treated by implanted pumps. The percentage of time spent with blood glucose in the 4.4–6.6 mmol/l range was the primary end point.

RESULTS
During the closed-loop phases, the mean ± SEM percentage of time spent with blood glucose in the 4.4–6.6 mmol/l range was significantly higher (39.1 ± 4.5 vs. 27.7 ± 6.2%, P = 0.05), and overall dispersion of blood glucose values was reduced among patients. Better closed-loop glucose control came from the time periods excluding the two early postprandial hours with a higher percentage of time in the 4.4–6.6 mmol/l range (46.3 ± 5.3 vs. 28.6 ± 7.4, P = 0.025) and lower mean blood glucose levels (6.9 ± 0.3 vs. 7.9 ± 0.6 mmol/l, P = 0.036). Time spent with blood glucose &lt;3.3 mmol/l was low and similar for both investigational phases.

CONCLUSIONS
Our results demonstrate the feasibility of intraperitoneal insulin delivery for an artificial β-cell and support the need for further study. Moreover, according to a semiautomated mode, the features of the premeal bolus in terms of timing and amount warrant further research.
Phase formation in sodium dodecylsulfate solutions in the presence of salicylic acid for preconcentration purposes
Authors: Starova Viktoriia , Kulichenko Sergey 
Published: October 2009

AbstractThe occurrence of surfactant-rich phases in aqueous sodium dodecylsulfate solutions in the presence of salicylic acid was investigated. The effect of acidity, electrolyte and salicylic acid concentrations on the parameters of phase formation were studied. Optimal conditions for microcomponent preconcentration were found. The features of solubilization efficiency changes of organic substances depending on their charge and hydrophobicity were established. High efficacy of preconcentration of strongly hydrophobic, positively charged substrates by low-temperature surfactant-rich phases obtained in the sodium dodecylsulfate-salicylic acid-sodium chloride ternary system is shown.