bluuebunny/crossref_metadata_2025_split huggingface dataset:
PTH Circadian Rhythm and PTH Target-Organ Sensitivity Is Altered in Patients With Adult Growth Hormone Deficiency With Low BMD
Authors: White Helen D , Ahmad Aftab M , Durham Brian H , Peter Rajesh , Prabhakar V Karthik B , Corlett Pamela , Vora Jiten P , Fraser William D 
Published: July 2007

Abstract
AGHD is associated with osteoporosis. We examined PTH circadian rhythmicity and PTH target-organ sensitivity in 23 patients with AGHD with low BMD and 20 patients with AGHD with normal BMD. Patients with low BMD had a blunted nocturnal rise in PTH concentration and reduced PTH target-organ sensitivity compared with patients with normal BMD; these factors may be important in the pathogenesis of AGHD-related osteoporosis.
Introduction: Adult growth hormone deficiency (AGHD) is associated with decreased BMD. Reduced parathyroid gland sensitivity to changes in calcium and reduced PTH target-organ sensitivity may underlie the pathogenesis of AGHD-related osteoporosis. A blunted nocturnal PTH rise has been reported in AGHD and may contribute to the reduction in BMD. We examined the difference in PTH concentration and markers of bone metabolism in patients with AGHD with normal and low BMD.
Materials and Methods: Forty-three patients with AGHD consented to the study. Twenty-five patients were growth hormone (GH) naïve (GH-N, 13 had BMD femoral neck or lumbar spine T-score &lt; −1.0), and 18 patients had received GH for &gt;2 yr (GH-R, 10 had BMD T-score &lt; −1.0). Patients were hospitalized for 24 h, where blood samples were collected every 0.5 h and urine samples were collected every 3 h for PTH, calcium, phosphate, NcAMP, 1,25-dihydroxyvitamin D [1,25(OH)2D], type-I collagen β C-telopeptide (βCTX), and procollagen type-I amino-terminal propeptide (PINP). Serum calcium was adjusted for albumin (ACa).
Results: Low BMD GH-N and GH-R patients exhibited a reduced nocturnal rise in PTH concentration compared with patients with normal BMD (p &lt; 0.001). GH-N low BMD patients had significantly higher 24-h mean PTH (p &lt; 0.001) than GH-N normal BMD patients, with significantly lower 24-h mean NcAMP, ACa, and 1,25(OH)2D (p &lt; 0.01), suggesting a reduction in renal PTH sensitivity. GH-R low BMD patients had significantly lower 24-h mean PTH, NcAMP, ACa, and 1,25(OH)2D (p &lt; 0.01) than GH-R normal BMD patients, suggesting reduced renal PTH action. Lower PTH concentration in the presence of lower ACa may reflect reduced sensitivity of the parathyroid calcium-sensing receptor to changes in ACa concentration in the GH-R low BMD patients.
Conclusions: Low BMD in GH-N and GH-R AGHD patients may be a consequence of abnormalities in PTH circadian rhythmicity together with reduced parathyroid gland and target-organ sensitivity. Further studies are needed to determine the potential benefit of therapeutic manipulation of PTH rhythmicity and sensitivity on BMD.
Osteoporosis Improvement: A Large-Scale Randomized Controlled Trial of Patient and Primary Care Physician Education
Authors: Solomon Daniel H , Katz Jeffrey N , Finkelstein Joel S , Polinski Jennifer M , Stedman Margaret , Brookhart M Alan , Arnold Marilyn , Gauthier Suzanne , Avorn Jerry 
Published: July 2007

Abstract
We conducted a randomized controlled trial within the setting of a large drug benefit plan for Medicare beneficiaries. Primary care physicians and their patients were randomized to usual care, patient intervention only, physician intervention only, or both interventions. There was no difference in the probability of the primary composite endpoint (BMD test or osteoporosis medication) or in either of its components comparing the combined intervention group with usual care (risk ratio = 1.04; 95% CI, 0.85–1.26).
Introduction: Fractures from osteoporosis are associated with substantial morbidity, mortality, and cost. However, only a minority of at-risk older adults receives screening and/or treatment for this condition. We evaluated the effect of educational interventions for osteoporosis targeting at-risk patients, primary care physicians, or both.
Materials and Methods: We conducted a randomized controlled trial within the setting of a large drug benefit plan for Medicare beneficiaries. Primary care physicians and their patients were randomized to usual care, patient intervention only, physician intervention only, or both interventions. The at-risk patients were women ≥65 yr of age, men and women ≥65 yr of age with a prior fracture, and men and women ≥65 yr of age who used oral glucocorticoids. The primary outcome studied was a composite of either undergoing a BMD test or initiating a medication used for osteoporosis. The secondary outcome was a hip, humerus, spine, or wrist fracture.
Results: We randomized 828 primary care physicians and their 13,455 eligible at-risk patients into four study arms. Physician and patient characteristics were very similar across all four groups. Across all four groups, the rate of the composite outcome was 10.3 per 100 person-years and did not differ between the usual care and the combined intervention groups (p = 0.5). In adjusted Cox proportional hazards models, there was no difference in the probability of the primary composite endpoint comparing the combined intervention group with usual care (risk ratio = 1.04; 95% CI, 0.85–1.26). There was also no difference in either of the components of the composite endpoint. The probability of fracture during follow-up was 4.2 per 100 person-years and did not differ by treatment assignment (p = 0.9).
Conclusions: In this trial, a relatively brief program of patient and/or physician education did not work to improve the management of osteoporosis. More intensive efforts should be considered for future quality improvement programs for osteoporosis.
Local Radial Displacement Measurements of Soil Specimens in a Triaxial Test Apparatus Using Laser Transducers
Authors: Messerklinger S. , Springman S. M. 
Published: July 2007

Abstract
A laser scanning device is introduced to measure radial displacements in triaxial testing apparatuses. The equipment provides contactless measurement of the radial displacement of the test specimen over the whole specimen height. Additionally, a method is proposed for determining the initial specimen volume from the scanned specimen profiles as well as the change in volume during test performance. These methods are then evaluated, based on test results from a drained stress path test on Swiss lacustrine clay.
Characterizing Fatigue Response of Nickel-Titanium Alloys by Rotary Beam Testing
Authors: Patel Mitesh M. 
Published: July 2007

Abstract
Fatigue information has been reliable in predicting wire critical structural integrity. The aim of this study is to expound on the characterization technique of rotary beam fatigue testing (RBT). By alternating tension and compression stress states through RBT, it is possible to determine the life expectancy of Nitinol monofilament round wires. Fatigue testing has been employed to characterize the influence of subtle changes in inclusion content, chemistry variations of raw material, ingot transformation temperatures of Nitinol (NiTi), and surface finish conditions for implant grade wires. Currently, an ASTM standard does not exist that concentrates solely on fatigue testing shape memory alloys. By exploiting part geometry, this testing technique serves to compliment other characterization methods. Evaluation of fracture surfaces has proven useful in diagnosing the factors influencing failures. The utilization of fatigue data and fracture mechanics compliments tensile testing in providing information to the design engineer. Results from studying flexural endurance, statistical Weibull life assessment analysis, fracture analysis, and a determination of stress/strain levels at the site of failure have proven useful in determining desired material properties for next generation medical devices.
Martensite Transformations and Fatigue Behavior of Nitinol
Authors: Adler P. H. , Allen J. , Lessar J. , Francis R. 
Published: July 2007

Abstract
In addition to excellent biocompatibility and corrosion resistance, the unique flow behavior of NiTi pseudo-elastic alloys renders them ideally suited for several medical device applications utilizing minimally invasive technologies. For example, self-expanding stents are indicated chronic therapies for treatment of a variety of vascular diseases. Long-term device integrity is thus critical with the FDA recommending a minimum 10-year life. Historically, the majority of published fatigue data on NiTi alloys have been generated under strain-controlled conditions using wire or single-diamond cell samples designed to replicate the behavior of the repetitive unit within a stent. Resulting data are then presented on modified Goodman or Soderberg diagrams in order to define regions of acceptable device life. Consistent with their unusual monotonic flow characteristics these alloys are found to exhibit unique cyclic behavior in fatigue: published data clearly demonstrate that increasing mean strain often increases high-cycle fatigue life. This anomalous behavior is generally attributed to any of a number of possible microstructural or mechanical effects associated with the reversible stress-assisted austenite-to-martensite phase transformation. Although the majority of published work has focused on these macroscopic properties in order to characterize and adequately define device life, various efforts are currently underway to better understand the more fundamental metallurgical and mechanical aspects controlling fatigue life in this alloy. Such studies include crack initiation and propagation rates, determining the roles of absolute and relative inherent flow behavior of the transforming structures, mechanical instabilities resulting from the heterogeneous nature of the transformation, latent heat effects during cyclic transformation, as well as the effects of testing frequency, crystallographic texture, grain-shape anisotropy, and stress-state on fatigue life. A review of existing literature delineating these behaviors and current efforts is presented in light of known beneficial effects of transformation plasticity and toughening in enhancing fatigue and fracture properties of a variety of metallic and nonmetallic materials.
New Twist-Off Method for the Evaluation of In-Situ Strength of Concrete
Authors: Naderi M. 
Published: July 2007

Abstract
This paper introduces an innovative partially destructive method called “Twist-off,” for the assessment of in situ concrete strength. In this method, a 40 mm diameter metal probe is bonded to a concrete surface by means of a high strength epoxy resin adhesive. To measure the concrete compressive strength, a torque is applied using an ordinary torque wrench and the maximum torque or shear stress at failure is used to estimate the cube compressive strength by means of a calibration graph. The relationship between the results of this new method and the compressive strengths of concrete cores as well as the correlation of this method with friction-transfer method are also presented in this paper. The average coefficient of variation of the results of this method was seen to be of the order of 8 % and the correlation coefficients of its comparative results with concrete cube and core compressive strengths were found to be 0.98 and 0.90, respectively. In order to assess the performance of this method on site, tests were undertaken on a number of concrete structures. Based on these results, this method is suggested for in situ determination of concrete strength.
Effects of Water Velocity and Trash Rack Architecture on Juvenile Fish Passage and Interactions: A Simulation
Authors: Floyd Emily Y. , Churchwell Roger , Cech Joseph J. 
Published: July 2007

AbstractMany resident and migratory fish species have experienced population declines due to modification of estuarine ecosystems. Fish screens (or louvers) have been designed to guide fish away from the diversion pumps, and trash racks have been placed upstream of the screens to intercept aquatic plants and debris. Although small fish may aggregate around these structures, potentially increasing their vulnerability to predators, we know little about the behavior, performance, and survival of fish near trash racks. To determine how trash rack flow regime and architecture influence fish behavior, we exposed juvenile threadfin shad Dorosoma petenense and winter‐run Chinook salmon Oncorhynchus tshawytscha to three water velocities and two bar‐spacing treatments in a circular tank bisected by a simulated trash rack. Our results suggest that relatively small increases in water velocity at diversion facilities will result in the aggregation of juvenile fish near trash racks. In contrast, bar spacing did not influence fish passage frequency or interaction in this study. We also found that threadfin shad selected higher velocities as water current increased, whereas Chinook salmon consistently showed a preference for moderate to low water velocities.
A Model for Estimating Passive Integrated Transponder (PIT) Tag Antenna Efficiencies for Interval‐Specific Emigration Rates
Authors: Horton Gregg E. , Dubreuil Todd L. , Letcher Benjamin H. 
Published: July 2007

AbstractOur goal was to understand movement and its interaction with survival for populations of stream salmonids at long‐term study sites in the northeastern United States by employing passive integrated transponder (PIT) tags and associated technology. Although our PIT tag antenna arrays spanned the stream channel (at most flows) and were continuously operated, we are aware that aspects of fish behavior, environmental characteristics, and electronic limitations influenced our ability to detect 100% of the emigration from our stream site. Therefore, we required antenna efficiency estimates to adjust observed emigration rates. We obtained such estimates by testing a full‐scale physical model of our PIT tag antenna array in a laboratory setting. From the physical model, we developed a statistical model that we used to predict efficiency in the field. The factors most important for predicting efficiency were external radio frequency signal and tag type. For most sampling intervals, there was concordance between the predicted and observed efficiencies, which allowed us to estimate the true emigration rate for our field populations of tagged salmonids. One caveat is that the model's utility may depend on its ability to characterize external radio frequency signals accurately. Another important consideration is the trade‐off between the volume of data necessary to model efficiency accurately and the difficulty of storing and manipulating large amounts of data.
Gastric Evacuation and Daily Ration of Naturally Produced Age‐0 Chinook Salmon in Lake Ontario
Authors: Principe Nicholas D. , Kraft Clifford E. , Mills Edward L. 
Published: July 2007

AbstractAlmost 30 years after natural reproduction of Chinook salmon Oncorhynchus tshawytscha was discovered in Lake Ontario tributaries, little is known about the feeding dynamics of these fish after they enter the lake. This study assesses consumption by naturally produced age‐0 Chinook salmon as they enter the nearshore region of Lake Ontario after emigrating from the Salmon River, New York, a major U.S. tributary of Lake Ontario. Evacuation rate, estimated as a function of temperature in controlled laboratory experiments, ranged from 0.214/h at 10°C to 0.352/h at 19°C. Diel field sampling for daily ration estimates occurred on three dates in late spring (June 6, 12, and 18, 2001). Although no consistent diel feeding pattern was observed, Chinook salmon maintained an elevated gut fullness value throughout the day and did not feed after dark. Moreover, daily rations (grams [dry weight] of ration per 100 g of dry fish weight), which ranged from 27.54 (SE = 3.07) on June 12 to 33.27 (3.7) on June 6, were high compared with the values obtained in similar studies. Comparisons of daily ration estimates with bioenergetics model estimates showed that juvenile Chinook salmon were consuming prey at or above their maximum estimated daily ration. Daily ring counts of sagittal otoliths confirmed that the Chinook salmon in this investigation were naturally produced. Our results indicate that current food conditions in the nearshore waters of Lake Ontario are suitable for sustaining maximum consumption rates by naturally produced juvenile Chinook salmon that have recently migrated into the lake from spawning tributaries.
Effects of Temperature and Feed Energy on the Performance of Juvenile Red Drum
Authors: Fontaine Lance P. , Whiteman Kasey W. , Li Peng , Burr Gary S. , Webb Kenneth A. , Goff Jonathan , Gatlin Delbert M. , Neill William H. , Davis Kenneth B. , Vega Robert R. 
Published: July 2007

AbstractWe tested the hypothesis that the growth of fish exposed to high temperatures can be limited by available food energy whereas that of fish exposed to low temperatures can be limited by their metabolic capacity to exploit the available food energy. Under laboratory conditions we evaluated growth (%/d) and marginal metabolic scope (MMS; L·g−1·h−1) of juvenile red drum Sciaenops ocellatus exposed to two levels of dietary energy, low (LE; ∼4.1 kJ/g) and high (HE; ∼15.9 kJ/g), and to three temperatures, approximately 19, 25, and 29°C, for a period of 6 weeks. Growth rate and MMS increased with temperature, but only growth rate increased with dietary energy and then only at the higher two temperatures. The simulation model Ecophys. Fish was employed to elucidate experimental results potentially confounded by interactions between fish weight and the controlling effects of temperature on metabolism. The simulated and observed results both showed that performance is enhanced at higher temperatures, especially for fish consuming the HE diet. A subsequent 6‐week‐long experiment confirmed results for fish fed the two diets at ambient temperature (∼26°C) and sought to further resolve responses by examining body condition indices and proximate composition. Additionally, these fish were assayed for differential cortisol response to 15 min of confinement stress. The feed efficiency, hepatosomatic index, intraperitoneal fat ratio, and whole‐body fat of fish fed the LE diet were significantly lower than those of fish fed the HE diet, indicating relative energy malnutrition in the LE group. As with MMS, no apparent differential effect of feed energy on the pre‐ or poststress values of plasma cortisol was observed. These findings support the ideas that red drum obtain greater metabolic capacity when they are exposed to a near‐optimal temperature and that their ability to transform that capacity into growth is maximized only when they are provided a nutritious, high‐energy diet.
A Simple Method for Estimating Survival Rate from Catch Rates from Multiple Years
Authors: Hoenig John M. , Gedamke Todd 
Published: July 2007

AbstractSurvival rates can be estimated from annual surveys by tracking the abundance of one or more cohorts, as measured by catch per unit of sampling effort, from one year to the next. However, it can be difficult to attain reasonable precision unless sampling effort is extensive. Indeed, estimates of survival exceeding 100% are not infrequently obtained. We show that data from several years can be analyzed simultaneously to obtain a single estimate of survival under the assumption that survival is constant over the period analyzed. The method requires that only a single cohort be identified and separated from the other age‐groups. Thus there are minimal data requirements. Estimates of the survival of goosefish Lophius americanus obtained by this method compare favorably with estimates obtained by analyzing changes in mean length over time.
Intra‐female aggression in the mouse (Mus musculus domesticus) is linked to the estrous cycle regularity but not to ovulation
Authors: Morè Lorenzo 
Published: July 2007

AbstractIntraspecific communication between mice takes place mainly via urinary chemosignals or “pheromones”. Pheromones can influence aggressive and reproductive behavior as well as the neuroendocrine condition of the recipient female mice via their olfactory system. In this study, reproductively cyclic mice in the estrus phase were used to test intraspecific agonistic aggressive behavior. Data were obtained also on the count of the eggs shed in the oviducts. The results showed that (i) individually housed female mice are more aggressive toward an intruder female mouse than grouped mice, (ii) mice in which the vomeronasal organ was removed show aggressive behavior intermediate between individually housed and grouped mice, and (iii) a within group analysis did not show a positive correlation between aggression and presence of shed eggs in the oviducts. Aggr. Behav. 34:46–50, 2008. © 2007 Wiley‐Liss, Inc.
Robust track‐following control of hard disk drives using improved integral sliding mode combined with phase lead peak filter
Authors: Hu Qinglei , Xie Lihua , Wang Youyi , Du Chunling 
Published: July 2007

AbstractAn integral‐type sliding mode control (SMC) scheme with application to track‐following control in hard disk drives (HDDs) is investigated in this paper. With the proposed technique, the dynamics of the sliding mode is analytically obtained without any reaching phase by using the integral sliding surface. To reconstruct estimates of the system states for use in a full information SMC law, an asymptotic observer is also employed and the fulfillment of sliding condition, including the case when estimated states are used, is also verified. In addition, the proposed control scheme integrated with a phase lead peak filter (PLPF) is also investigated for better rejection of disturbance of narrow‐band type at mid‐frequency ranges. Simulation studies on the design of a track‐following controller in HDDs are conducted to illustrate its feasibility and effectiveness. The simulation results also demonstrate that the proposed scheme provides better performance than the conventional sliding mode and proportional–integral–derivative control methods. Copyright © 2007 John Wiley & Sons, Ltd.
Run‐to‐run control of membrane filtration processes
Authors: Busch Jan , Cruse Andreas , Marquardt Wolfgang 
Published: July 2007

AbstractMembrane filtration processes are often operated cyclically, where one cycle comprises a filtration and a backwashing phase. Due to the complex mechanisms involved, these processes are mostly operated with fixed values of the manipulated variables, leaving much of the economical potential unexplored. A model‐based run‐to‐run process control approach is introduced, in which the manipulated variables are optimized after each filtration cycle. The approach is evaluated in a case study on submerged membrane filtration in wastewater treatment. A simple, computationally inexpensive process model is developed. The resulting model‐based controller is tested in a simulation environment employing a validated reference model. It yields excellent results with respect to prediction quality and optimization results. © 2007 American Institute of Chemical Engineers AIChE J, 2007