bluuebunny/crossref_metadata_2025_split huggingface dataset:
A preliminary model study of the equine back including activity of longissimus dorsi muscle
Authors: GROESEL M. , ZSOLDOS R. R. , KOTSCHWAR A. , GFOEHLER M. , PEHAM C. 
Published: November 2010

SummaryReasons for performing study: Identifying the underlying problem of equine back pain and diseases of the spine are significant problems in veterinary orthopaedics. A study to validate a preliminary biomechanical model of the equine back based on CT images including longissimus dorsi (LD) muscle is therefore important.Objectives: Validation of the back model by comparing the shortening of LD muscles in the model with integrated EMG (IEMG) at stance during induced lateral flexion of the spine.Methods: Longissimus dorsi muscle activity at stance has been used for validation. EMG electrodes were placed laterally at the level of T12, T16 and L3. Reflective markers have been attached on top of the spinous processes T5, T12, T16, L1 and the sacral bone (OS1, OS2) for motion tracking analysis. A virtual model of the equine's back (T1–S5) was built with inclusion of a simplified LD muscle by 2 separate contours left and right of the spine, starting at tuber coxae laterally and attaching to the spinous process T5 medially. Shortening of LD during induced lateral flexion caused by the kinematic data (input) was compared to the 3 EMG signals (T12, T16 and L3) on the active side via correlation.Results: Pearson correlation coefficient between IEMG and shortening length of LD in the model was (mean ± s.d.) 0.95 ± 0.07 for the left side and 0.91 ± 0.07 for the right side of LD.Conclusions: Activity of the LD muscles is mainly responsible for stabilisation of the vertebral column with isometric muscle contraction against dynamic forces in walk and trot. This validation requires muscle shortening in the back, like induced lateral flexion at stance. The length of the shortening muscle model and the IEMG show a linear relationship. These findings will help to model the LD for forward simulations, e.g. from force to motion.
The effect of sildenafil citrate administration on selected physiological parameters of exercising Thoroughbred horses
Authors: COLAHAN P. T. , JACKSON C. A. , RICE B. , SZABO N. , JONES J. H. 
Published: November 2010

SummaryReasons for performing study:Sildenafil, a phosphodiesterase‐5 inhibitor vasodilator, increases cGMP concentrations by inhibiting enzymatic degradation. Marketed to treat erectile dysfunction in men, it also reduces pulmonary arterial pressure (PAP). Because it reduces PAP, sildenafil may enhance performance and/or prevent exercise induced‐pulmonary haemorrhage (EIPH).Objective:To determine if sildenafil citrate administration altered commonly measured indices of performance or reduced EIPH in exercised horses.Methods:Thirteen athletically conditioned Thoroughbred horses (2 mares and 11 geldings, age 3–12 years) were administered sildenafil citrate or placebo in 2 crossover design exercise testing studies. In a step‐wise test to exhaustion, inspired/expired gas analysis, blood lactate, heart rate, runtime and bronchoalveolar lavage (BAL) cytology were measured. In a 13 m/s test to exhaustion, blood lactate, heart rate, runtime, BAL cytology and pulmonary arterial pressure were measured. Data were analysed with paired and unpairedttests, one‐way ANOVA and Tukey's pair‐wise multiple comparison and Friedman repeated measure analysis of variance on ranks.Results:The administration of sildenafil did not alter mean inspired/expired gas measurements, plasma lactate concentrations or acute pulmonary haemorrhage in either exercise test or pulmonary arterial pressure measurement in the 13 m/s trial. Heart rates in both stress tests were significantly different at submaximal speeds and during the early recovery period. Run time was not affected by sildenafil administration in the step‐wise trial (P = 0.622) or in the 13 m/s trial (P = 0.059).Conclusions:Sildenafil did not alleviate pulmonary haemorrhage or enhance performance‐related indices in these trials. Sildenafil administration altered cardiovascular adaptation to intense exercise as evidenced by altered heart rates at submaximal speeds and post exercise. The effect of these alterations on other performance perimeters was not evident.
The role of tendon stiffness in development of equine locomotion with age
Authors: ADDIS P. R. , LAWSON S. E. M. 
Published: November 2010

SummaryReasons for performing study:The flexor tendons support the metacarpophalangeal (MCP) and distal interphalangeal (DIP) joints during stance phase and since tendon stiffness and strain changes with age, it is likely that kinematics are also age‐dependent.Hypothesis:Maximum MCP and DIP angles decrease in the young horse, plateau in the mature horse and increase towards senescence.Methods:The distal limbs of 57 walking horses age 3–212 months were filmed and digitised with an automated tracking system. Maximum MCP and DIP angles during stance phase were used to calculate strain in the superficial and deep digital flexor tendons. Horses were divided into 3 age groups; young (3–35 months), mature (36–99 months) and older horses (100–212 months). Pearson's correlation coefficients were calculated to determine the relationship between age and kinematics.Results:Tendon strain decreased in young horses, stayed constant in mature horses and increased in older horses. Joint angles showed significant negative correlation in young horses, with coefficients of −0.88 (MCP) and −0.81 (DIP). In mature horses, correlations were not significant (P = 0.2 for MCP; P = 0.5 for DIP). In older horses, angles showed significant positive correlation, with coefficients of 0.62 (MCP) and 0.48 (DIP).Conclusions:Joint angles decreased in the young horse as tendon stiffness increases, remained constant in the mature horse where tendon stiffness is constant and increased in older horses as tendons weakens and stiffness decreases. Strain patterns were similar to those foundin vitro.Potential relevance:Changing tendon stiffness appeared to influence the development and degeneration of gait. This has implications for studying musculoskeletal development, especially for identification of normal and pathological development.
Effects of flunixin on cardiorespiratory, plasma lactate and stride length responses to intense treadmill exercise in Standardbred trotters
Authors: KALLINGS P. , PERSSON S. G. B. , ESSÉN‐GUSTAVSSON B. 
Published: November 2010

SummaryReasons for performing study:Since nonsteroidal anti‐inflammatory drugs, such as flunixin, on account of their anti‐inflammatory and analgesic properties, are used in both racing and equestrian sport horses, the question has been raised as to whether these drugs affect the physiological responses to exercise and thus performance potential.Objectives:The aims of this investigation were to study the effects of flunixin on cardiorespiratory, metabolic and locomotor parameters in horses during intense treadmill exercise.Methods:Six Standardbred trotters underwent an incremental treadmill exercise test to fatigue, without drug and then after administration of flunixin meglumine (1.1 mg/kg bwt i.m.). Heart rate (HR), oxygen uptake and stride length were measured and venous blood samples drawn repeatedly during the test.Results:Heart rates were found to be significantly higher at submaximal speeds, while the velocity causing a HR of 200 beats/min was significantly decreased after treatment with flunixin. Maximal HR and plasma lactate concentration 5 min after exercise were unchanged after medication. Flunixin caused higher plasma lactate concentrations at all speeds and the lactate threshold was decreased, compared with baseline values. Oxygen uptake levelled off at the highest velocities and did not change after flunixin treatment. Stride length was increased after treatment, although not at the highest velocities.Conclusion:The increased HR and lactate responses to exercise after flunixin treatment indicate that it does influence physiological responses, but does not improve the performance potential of clinically healthy horses. However, the lengthened stride during submaximal exercise after medication could imply undetected subclinical lameness, masked in some of the horses, i.e. they have performed with a longer stride at the cost of a higher heart rate and an increased lactate concentration.
Integrated approach to geomodelling and dynamic simulation in a complex mixed siliciclastic–carbonate reservoir, N'Kossa field, Offshore Congo
Authors: Wonham J. P. , Cyrot M. , Nguyen T. , Louhouamou J. , Ruau O. 
Published: November 2010

Abstract
The Lower Sendji Carbonate (Albian age) of the N'Kossa field is a mixed siliciclastic–carbonate reservoir exhibiting very heterogeneous reservoir properties and the development of extensive vertical flow permeability barriers. The reservoir is a succession of interstratified dolomite, limestone, sandstone and shale lithologies of sabkha, tidal flat and lagoonal origin. Early, synsedimentary dolomite cements are extensively developed, particularly over local palaeohighs.
Challenges to hydrocarbon production include: (1) the vertical variability of reservoir properties; (2) the presence of many, laterally extensive vertical flow barriers; and (3) variable connectivity between fault-bounded compartments. This complexity was underestimated at the appraisal stage, the initial development plan calling for a relatively simple scheme of pressure support to the critical reservoir fluid via injection into the gas cap and the water leg. This decision was supported by the identification of a single hydrocarbon column (>400 m thick) over the entire structure which suggested a lack of vertical compartmentalization.
Recent studies, which include a geological synthesis of more than forty wells and a dynamic data synthesis to determine the production mechanism and identify key heterogeneities, show a lack of pressure support to the oil leg from both water and gas injector wells. Today, integration of static and dynamic data together with an improved geological understanding of the stratigraphic control on vertical flow barriers and mapping of high permeability sandstone layers is the key to identifying unswept zones of the field and future infill drilling targets.
Prediction of stratigraphic compartmentalization in marginal marine reservoirs
Authors: Ainsworth R. B. 
Published: November 2010

Abstract
Marginal marine depositional systems exhibit stratigraphic reservoir compartmentalization potential at three hierarchical scales. At each of these scales, stratigraphic compartmentalization potential can be related to the dominant depositional processes and accommodation:coarse sediment supply ratio (A/S) that are acting at the time of deposition. All three orders of compartmentalization potential must be considered in order to define optimal field development plans and completion strategies. The lowest order of compartmentalization is usually at the inter-parasequence scale. The parasequence is represented by a conformable succession of strata separated by marine flooding surfaces and as such it generally defines the basic flow unit in marginal marine systems. In systems tracts associated with relatively high A/S ratios, for example late Lowstand, Transgressive and early Highstand (steeply rising shoreline trajectories), vertical compartmentalization potential is relatively high because of the enhanced preservation potential of flooding surface shales under these conditions. In systems tracts associated with relatively low A/S ratios, for example late Highstand, Falling-stage and early Lowstand (flat, slightly rising and falling shoreline trajectories), vertical compartmentalization potential of parasequences is reduced because the potential for erosion of flooding surface shales by overlying deposits is high and hence potential for vertical sand–sand contact between parasequences is enhanced. The second level of compartmentalization hierarchy is the inter sand-body scale. Individual sand bodies are defined within parasequences. The lateral connectivity of these sand bodies is a product of the dominant depositional processes active at the time of their deposition (wave, tidal, fluvial). Wave-dominated systems tend to produce more laterally continuous sand bodies, fluvial-dominated systems more laterally restricted sand bodies and tide-dominated systems both laterally continuous and laterally restricted sand bodies. Vertical compartmentalization potential of these reservoir sand bodies is related to A/S regime. In high A/S regimes, sand bodies are more likely to be disconnected or compartmentalized. In low A/S regimes, erosional amalgamation of sand bodies is more likely thereby leading to lower compartmentalization potential. The third order of potential stratigraphic compartmentalization is the intra sand-body scale. This scale is represented by intra sand-body heterogeneities such as dipping or horizontal shales, carbonaceous-rich beds or laminae, shale abandonment plugs of channels and carbonate concretions. In high A/S regimes the preservation potential of these heterogeneities is relatively high leading to an enhanced potential for intra sand-body compartmentalization. Lower A/S regimes result in a greater likelihood of lateral and vertical erosion of these heterogeneities leading to a higher potential for reservoir connectivity.
Stratigraphic and structural connectivity
Authors: Hovadik J. M. , Larue D. K. 
Published: November 2010

Abstract
The connectivity of a reservoir to a well-bore represents a fundamental initial condition for drainage of an oil or gas field. The size of the static connected volume is a function of the stratigraphic and structural architecture of the reservoir. The most important stratigraphic factor affecting connectivity is a net-to-gross threshold which determines whether a reservoir is highly or poorly connected. Other stratigraphic factors affecting connectivity are those that impact the reservoir dimensionality (for example, compartmentalizing continuous mudstones or parallel channel deposits) and the size of geobodies relative to the total reservoir size. Structural compartmentalization may cause fault compartments that are too small in volume to support reservoir connectivity: as the size of the geobodies approaches compartment size, connectivity is typically less predictable. Static connected volumes alone do not predict flow performance, but are a component in predicting flow performance. To more completely address predictions of flow performance, dynamic connectivity is sometimes considered. However, dynamic connectivity, which is dependent on fluid type, permeability heterogeneity, time and other factors, confuses connectivity with tortuosity and sweep- and displacement-efficiency and is probably best avoided. Finally a connectivity flow diagram is proposed as a guide to help formulate key questions concerning uncertain reservoir parameters affecting reservoir connectivity.
Integration of time-lapse geochemistry with well logging and seismic to monitor dynamic reservoir fluid communication: Auger field case-study, deep water Gulf of Mexico
Authors: Chuparova E. , Kratochvil T. , Kleingeld J. , Bilinski P. , Guillory C. , Bikun J. , Djojosoeparto R. 
Published: November 2010

Abstract
The present study illustrates the multi-disciplinary integration of time-lapse geochemistry with 4D seismic, production logging and pressure history analysis in the Auger Blue reservoirs. The integrated approach enables identification of dynamic fluid reservoir communication occurring after six years of primary production between an oil (Lower Blue O2) and a gas reservoir (Blue O Massive) indicated by pressure data as separate at static conditions, and points to cross-fault leakage with possible stratigraphic communication as the likely mechanism(s) by which dynamic fluid reservoir communication has occurred.
The time-lapse geochemistry study was performed utilizing fluid samples collected during a period of over eight years of primary production. The results present evidence for gradual mixing of Lower Blue O2 oil with the condensates of the Blue O Massive reservoir. Time-lapse geochemistry results also pinpointed the timing when dynamic reservoir communication started to occur, with an initial mixing detected as early as six years after the start of production. Statistical evaluation of the geochemistry results showed the contribution of the oil to the gas condensate reservoir to significantly increase from 14–23% to 60–63% within a year from when mixing was initially detected. The results of the study assisted in implementing an improved field development strategy to increase production.
Cost-Effectiveness of Colorectal Cancer Screening in High-Risk Spanish Patients: Use of a Validated Model to Inform Public Policy
Authors: Ladabaum Uri , Ferrandez Angel , Lanas Angel 
Published: November 2010

AbstractBackground: The European Community has made a commitment to colorectal cancer (CRC) screening, but regional considerations may affect the design of national screening programs. We developed a decision analytic model tailored to a pilot screening program for high-risk persons in Spain with the aim of informing public policy decisions.Materials and Methods: We constructed a decision analytic Markov model based on our validated model of CRC screening that reflected CRC epidemiology and costs in persons with first-degree relatives with CRC in Aragón, Spain, and superimposed colonoscopy every 5 or 10 years from ages 40 to 80 years. The pilot program's preliminary clinical results and our modeling results were presented to regional health authorities.Results: In the model, without screening, 88 CRC cases occurred per 1,000 persons from age 40 to 85 years. In the base case, screening reduced this by 72% to 77% and gained 0.12 discounted life years per person. Screening every 10 years was cost saving, and screening every 5 years versus every 10 years cost 7,250 euros per life year gained. Based on these savings, 36 to 39 euros per person per year could go toward operating costs while maintaining a neutral budget. If screening costs doubled, screening remained highly cost-effective but no longer cost saving. These results contributed to the health authorities' decision to expand the pilot program to the entire region in 2009.Conclusions: Colonoscopic screening of first-degree relatives of persons with CRC may be cost saving in public systems like that of Spain. Decision analytic modeling tailored to regional considerations can inform public policy decisions.Impact: Tailored decision analytic modeling can inform regional policy decisions on cancer screening. Cancer Epidemiol Biomarkers Prev; 19(11); 2765–76. ©2010 AACR.
Interaction of Area-Level Socioeconomic Status and UV Radiation on Melanoma Occurrence in California
Authors: Clarke Christina A. , Moy Lisa M. , Swetter Susan M. , Zadnick John , Cockburn Myles G. 
Published: November 2010

Abstract
Background: Melanoma incidence has been correlated strongly and positively with both socioeconomic status (SES) and lower latitude and other measures of ambient UV radiation (UVR). However, because high-SES populations may be colocated in areas of high UVR, we assessed their joint influences on melanoma occurrence to better target subpopulations for melanoma education and screening.
Methods: We obtained from the California Cancer Registry information regarding 23,564 incident cases of invasive cutaneous melanoma among non-Hispanic white residents between January 1, 1998, and December 31, 2002. We geocoded each case based on residence at diagnosis and linked previously tested neighborhood measures of SES and average annual UVR to calculate age-adjusted incidence rates, rate ratios, and the corresponding 95% confidence intervals. Poisson regression was used to calculate multivariately adjusted rate ratios.
Results: UVR was significantly and positively associated with melanoma incidence only among persons living in the top 40% of California neighborhoods ranked by SES. People in neighborhoods of the highest SES and UVR categories had 60% higher rates of melanoma than those from neighborhoods in the lowest categories (rate ratio, 1.60; 95% confidence interval, 1.02-2.51).
Conclusion: Our findings indicate that UVR and SES interact to influence melanoma occurrence and suggest that socioeconomic gradients in melanoma incidence are not explained entirely by UVR.
Impact: Cancer prevention and early detection educational efforts should be targeted to high-SES groups in areas of high UVR exposure. Contextual measures of both SES and UVR should be considered important determinants of melanoma occurrence in future studies. Cancer Epidemiol Biomarkers Prev; 19(11); 2727–33. ©2010 AACR.
Is Discussion of Colorectal Cancer Screening Options Associated with Heightened Patient Confusion?
Authors: Jones Resa M. , Vernon Sally W. , Woolf Steven H. 
Published: November 2010

AbstractBackground: Clinical guidelines recommend offering patients options for colorectal cancer (CRC) screening, but the modalities vary by frequency, accuracy, preparations, discomfort, and cost, which may cause confusion and reduce screening rates. We examined whether patients reported confusion about the options and whether confusion was associated with socio-demographic characteristics, number of options discussed, and adherence.Methods: Patients ages 50 to 75 years who had visited a clinician within 2 years were randomly selected for a cross-sectional study (n = 6,100). A questionnaire mailed in 2007 asked the following: whether a clinician had ever discussed CRC screening options; which of four recommended tests (i.e., fecal occult blood testing, flexible sigmoidoscopy, colonoscopy, and barium enema) were presented; and whether the options were confusing. Analyses were restricted to respondents who reported discussing one or more screening options (n = 1,707). Weighted frequencies were calculated and multivariate logistic regression was done.Results: The sample was 55.5% female, 15.6% African American, and 83.2% adherent to screening recommendations, and 56.0% had discussed two or more screening options. In adjusted analyses, nonadherent patients reported greater confusion than adherent patients (P &lt; 0.01). Adults who discussed two or more options were 1.6 times more likely to be confused than those who discussed one option [95% confidence interval (CI), 1.08-2.26]. Patients who reported being confused were 1.8 times more likely to be nonadherent to screening than those who did not (95% CI, 1.14-2.75).Conclusions: Our study provides the first empirical evidence linking multiple options with confusion and confusion with screening adherence.Impact: Confusion may act as a barrier to screening and should be considered in public health messages and interventions. Cancer Epidemiol Biomarkers Prev; 19(11); 2821–5. ©2010 AACR.