bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in bone mineral density in the proximal femur after hip resurfacing and uncemented total hip replacement
Authors: Smolders J. M. H. , Hol A. , Rijnders T. , van Susante J. L. C.
Published: November 2010

We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age.

The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p < 0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months.

Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery.
Intercarpal ligamentous laxity in cadaveric wrists
Authors: Rimington T. R. , Edwards S. G. , Lynch T. S. , Pehlivanova M. B.
Published: November 2010

The purposes of this study were to define the range of laxity of the interosseous ligaments in cadaveric wrists and to determine whether this correlated with age, the morphology of the lunate, the scapholunate (SL) gap or the SL angle. We evaluated 83 fresh-frozen cadaveric wrists and recorded the SL gap and SL angle. Standard arthroscopy of the wrist was then performed and the grades of laxity of the scapholunate interosseous ligament (SLIL) and the lunotriquetral interosseous ligament (LTIL) and the morphology of the lunate were recorded. Arthroscopic evaluation of the SLIL revealed four (5%) grade I specimens, 28 (34%) grade II, 40 (48%) grade III and 11 (13%) grade IV. Evaluation of the LTIL showed 17 (20%) grade I specimens, 40 (48%) grade II, 28 (30%) grade III and one (1%) grade IV.

On both bivariate and multivariate analysis, the grade of both the SLIL and LTIL increased with age, but decreased with female gender. The grades of SLIL or LTIL did not correlate with the morphology of the lunate, the SL gap or the SL angle. The physiological range of laxity at the SL and lunotriquetral joints is wider than originally described. The intercarpal ligaments demonstrate an age-related progression of laxity of the SL and lunotriquetral joints. There is no correlation between the grades of laxity of the SLIL or LTIL and the morphology of the lunate, the SL gap or the SL grade. Based on our results, we believe that the Geissler classification has a role in describing intercarpal laxity, but if used alone it cannot adequately diagnose pathological instability.

We suggest a modified classification with a mechanism that may distinguish physiological laxity from pathological instability.
Delayed-type hypersensitivity reaction to piperacillin/tazobactam in a patient with an infected total knee replacement
Authors: Song E. K. , Seon J. K. , Jeong M. S.
Published: November 2010

We describe a patient who developed a delayed-type hypersensitivity reaction to piperacillin/tazobactam in the cement beads and a spacer inserted at revision of total replacement of the left knee. We believe that this is the first report of such a problem. Our experience suggests that a delayed-type hypersensitivity reaction should be considered when a mixture of antibiotics such as piperacillin/tazobactam has been used in the bone cement, beads or spacer and the patient develops delayed symptoms of pain or painful paraesthesiae, fever, rash and abnormal laboratory findings in the absence of infection. The diagnosis was made when identical symptoms were induced by a provocation challenge test.
Anterior fusion alone compared with combined anterior and posterior fusion for the treatment of degenerative cervical kyphosis
Authors: Song K.-J. , Johnson J. S. , Choi B.-R. , Wang J. C. , Lee K.-B.
Published: November 2010

We evaluated the efficacy of anterior fusion alone compared with combined anterior and posterior fusion for the treatment of degenerative cervical kyphosis. Anterior fusion alone was undertaken in 15 patients (group A) and combined anterior and posterior fusion was carried out in a further 15 (group B). The degree and maintenance of the angle of correction, the incidence of graft subsidence, degeneration at adjacent levels and the rate of fusion were assessed radiologically and clinically and the rate of complications recorded. The mean angle of correction in group B was significantly higher than in group A (p = 0.0009). The mean visual analogue scale and the neck disability index in group B was better than in group A (p = 0.043, 0.0006). The mean operation time and the blood loss in B were greater than in group A (p < 0.0001, 0.037). Pseudarthrosis, subsidence of the cage, and problems related to the hardware were more prevalent in group A than in group B (p = 0.034, 0.025, 0.013).

Although the combined procedure resulted in a longer operating time and greater blood loss than with anterior fusion alone, our results suggest that for the treatment of degenerative cervical kyphosis the combined approach leads to better maintenance of sagittal alignment, a higher rate of fusion, a lower incidence of complications and a better clinical outcome.
The histology around the cemented Müller straight stem
Authors: Clauss M. , Ilchmann T. , Zimmermann P. , Ochsner P. E.
Published: November 2010

The aim of this study was to obtain detailed long-term data on the cement-bone interface in patients with cemented stems, implanted using the constrained fixation technique. A total of eight stems were removed together with adjacent bone during post-mortem examinations of patients with well-functioning prostheses. Specimens were cut at four defined levels, contact radiographs were obtained for each level, and slices were prepared for histological analysis. Clinical data, clinical radiographs, contact radiographs and histological samples were examined for signs of loosening and remodelling. The mean radiological follow-up was 9.6 years and all stems were well-fixed, based on clinical and radiological criteria. Contact radiographs revealed an incomplete cement mantle but a complete filling of the medullary canal for all implants. Various amounts of polyethylene particles were evident at the cement-bone interface of seven stems, with no accompanying inflammatory reaction. Cortical atrophy and the formation of an ‘inner cortex’ were confirmed in six of eight stems by contact radiographs and histology, but were only visible on two clinical radiographs.

Our results confirm that a complete cement mantle is not essential for the survival of Müller straight stems into the mid term, and support our hypothesis that no benefit to long-term survival can be expected from modern cementing techniques.
The ABC Travelling Fellowship 2010
Authors: Biant L. C. , Rangan A. , Costa M. L. , Muir D. C. W. , Weinrauch P. C. L. , Clasper J. C. , Dix-Peek S. I.
Published: November 2010

The 2010 Fellows undertook a six-week journey through centres of orthopaedic excellence along the East Coast of Canada and the United States. What we learned and gained from the experience and each other is immeasurable, but five areas particularly stand out; education, research, service delivery, financial insights and professional development.
Fractures of the pelvis
Authors: Guthrie H. C. , Owens R. W. , Bircher M. D.
Published: November 2010

High energy fractures of the pelvis are a challenging problem both in the immediate post-injury phase and later when definitive fixation is undertaken. No single management algorithm can be applied because of associated injuries and the wide variety of trauma systems that have evolved around the world.

Initial management is aimed at saving life and this is most likely to be achieved with an approach that seeks to identify and treat life-threatening injuries in order of priority. Early mortality after a pelvic fracture is most commonly due to major haemorrhage or catastrophic brain injury. In this article we review the role of pelvic binders, angiographic embolisation, pelvic packing, early internal fixation and blood transfusion with regard to controlling haemorrhage.

Definitive fixation seeks to prevent deformity and reduce complications. We believe this should be undertaken by specialist surgeons in a hospital resourced, equipped and staffed to manage the whole spectrum of major trauma. We describe the most common modes of internal fixation by injury type and review the factors that influence delayed mortality, adverse functional outcome, sexual dysfunction and venous thromboembolism.
Going Global with Innovations from Emerging Economies: Investment in Customer Support Capabilities Pays Off
Authors: Khavul Susanna , Peterson Mark , Mullens Drake , Rasheed Abdul A.
Published: November 2010

Globalization of innovation calls for entrepreneurial new ventures from emerging economies to develop customer-focused dynamic capabilities. The authors argue that firms with proprietary technology and a strategic intent to internationalize invest in international customer support capabilities to satisfy the demands of their most important international customers. Using a unique sample of 173 international new ventures from China and India, the authors show that such investments are associated with improved organizational learning and performance. The results suggest that globalization pays off when entrepreneurial firms from emerging economies invest in ongoing support of their most important international customers.
Extending the Environment–Strategy–Performance Framework: The Roles of Multinational Corporation Network Strength, Market Responsiveness, and Product Innovation
Authors: Lee Ruby P.
Published: November 2010

The purpose of this study is to extend the traditional environment–strategy–performance framework by including network theory to examine when a foreign firm can use its multinational corporation (MNC) network strength to buffer market turbulence and technological turbulence and when the foreign firm can deploy it to support the influences of marketing strategic postures (i.e., market responsiveness and product innovation) on firm performance. The author tests the hypotheses on data collected from 140 foreign firms in China. Although prior research has demonstrated that firms often use multiple strategies and resources to cope with environmental forces, the findings illustrate that different environmental segments have unequal bearings on market responsiveness, product innovation, and MNC network strength. In addition, despite the direct positive influences of individual marketing strategic postures and MNC network strength on firm performance, their combined effects are mixed. The author concludes with a discussion of the implications of these results for research and practice.
Managing Knowledge for Innovation: The Role of Cooperation, Competition, and Alliance Nationality
Authors: Zhang Haisu , Shu Chengli , Jiang Xu , Malter Alan J.
Published: November 2010

Strategic alliances play a critical role in global innovation. Firms can overcome resource constraints and achieve superior innovative performance not only by using internal resources but also by acquiring knowledge-based capabilities from alliance partners. In this study, the authors investigate how knowledge acquired from alliance partners affects organizational knowledge creation, which in turn leads to innovative performance. The authors propose that the knowledge–innovation relationship is stronger in international alliances than domestic alliances. The results from a survey of 127 German firms engaged in strategic alliances confirm that knowledge creation mediates the effect of knowledge acquisition on innovative performance and that international alliances strengthen the effect of knowledge creation on innovative performance. In addition, the authors find that interfirm cooperation and competition coexist in strategic alliances and that both factors increase knowledge acquisition, though from different motivational bases.
Sorption isotherm of lodgepole pine (Pinus contorta Dougl. Ex Loud.) pulp chips affected by the mountain pine beetle (Dendroctonus ponderosae)
Authors: Todoruk Tara M. , Hartley Ian D.
Published: November 2010

No abstract available
Near infrared spectroscopy (NIRS) as a potential tool for monitoring trade of similar woods: Discrimination of true mahogany, cedar, andiroba, and curupixá
Authors: Pastore Tereza Cristina Monteiro , Braga Jez Willian Batista , Coradin Vera Terezinha Rauber , Magalhães Washington Luiz Esteves , Okino Esmeralda Yoshico Arakaki , Camargos José Arlete Alves , de Muñiz Graciela Inês Bonzon , Bressan Otávio Augusto , Davrieux Fabrice
Published: November 2010

Mahogany is one of the most valuable woods and was widely used until it was included in Appendix II of the Convention on International Trade in Endangered Species as endangered species. Mahogany wood sometimes is traded under different names. Also, some similar woods belonging to the Meliaceae family are traded as “mahogany” or as being of a “mahogany pattern”. To investigate the feasibility of the use of near infrared spectroscopy for wood discrimination, the mahogany (Swietenia macrophylla King.), andiroba or crabwood (Carapa guianensis Aubl.), cedar (Cedrela odorata L.), and curupixá (Micropholis melinoniana Pierre) woods were examined. Four discrimination models based on partial least squares-discriminant analysis were developed based on a calibration set composed of 88 samples and a test set with 44 samples. Each model corresponds to the discrimination of a wood species from the others. Optimization of the model was performed by means of the OPUS® software followed by statistical analysis software (Matlab®). The observed root mean square errors of predictions were 0.14, 0.09, 0.12, and 0.06 for discriminations of mahogany, cedar, andiroba, and curupixá, respectively. The separations of the species obtained based on the difference in the predicted values was at least 0.38. This makes it possible to perform safe discriminations with a very low probability of misclassifying a sample. This method can be considered accurate and fast.
Modelling time-dependent mechanical behaviour of softwood using deformation kinetics
Authors: Engelund Emil Tang , Svensson Staffan
Published: November 2010

The time-dependent mechanical behaviour (TDMB) of softwood is relevant, e.g., when wood is used as building material where the mechanical properties must be predicted for decades ahead. The established mathematical models should be able to predict the time-dependent behaviour. However, these models are not always based on the actual physical processes causing time-dependent behaviour and the physical interpretation of their input parameters is difficult. The present study describes the TDMB of a softwood tissue and its individual tracheids. A model is constructed with a local coordinate system that follows the microfibril orientation in the S2 layer of the cell wall. The inclination of the local system to the global coordinate system reflects the microfibril angle of the tracheid. Normal excitations in the local system perform linear elastically, whereas shearing excitation in the local system produces both elastic and inelastic responses. The results of the model are compared with experimental results of different types. It was observed that the model is able to describe the results. Moreover, to some surprise, the introduction of only elastic and viscous properties on the microscopic scale leads to an apparent macroscopic viscoelasticity, i.e., the time-dependent processes are to a significant degree reversible.
A Review of Pb-Free High-Temperature Solders for Power-Semiconductor Devices: Bi-Base Composite Solder and Zn–Al Base Solder
Authors: Takaku Y. , Ohnuma I. , Yamada Y. , Yagi Y. , Nakagawa I. , Atsumi T. , Shirai M. , Ishida K.
Published: November 2010

Pb-base high-temperature solders (mass % Sn=5–10, melting point (m.p.)=300–310°C) are widely applied under severe conditions, although the harmful nature of Pb is recognized. Bi-base alloys (m.p. of Bi=270°C), Zn-base alloys (m.p. of Zn=420°C), and several Au-base eutectic alloys (m.p. of Au-20Sn and Au-3.6Si=280 and 363°C, respectively) are proposed as candidates for Pb-free high-temperature solders. This paper reviews the features of Bi-base composite solders containing reinforcement particles of a superelastic Cu–Al–Mn alloy in a Bi matrix to relax thermal stress and to prevent the propagation of cracks, and Zn–Al base solders, which have high stability and high reliability enough to be utilized in practical applications under severe thermal cycle tests between −40 and 230°C more than 2000 cycles.
Diabetes in Pregnancy
Authors: Dailey Tanya L. , Coustan Donald R.
Published: November 2010

Diabetes is one of the most common medical complications affecting pregnancy. Diabetes in pregnancy is classified into two categories: pregestational diabetes and gestational diabetes (GDM). Pregestational diabetes comprises both type 1 and type 2 diabetes. GDM refers to those individuals diagnosed with carbohydrate intolerance during pregnancy. Regardless of the type of diabetes, pregnancies complicated by diabetes require specialized care and management to ensure the best outcomes for both the mother and the fetus. The management of diabetes is aimed at controlling fasting and postprandial blood glucose concentrations to decrease the known maternal and neonatal sequelae of GDM, including stillbirth, macrosomia, and neonatal metabolic derangements. In general, a carbohydrate-controlled diet, vigilant monitoring of glucose values, and in many individuals, insulin therapy form the mainstay of therapy. In addition to glucose control, increased fetal surveillance is necessary to ensure proper development, appropriate growth, and fetal well-being. Although diabetes requires a multidisciplinary approach that includes physicians and nurses who have specialized training in diabetes, pediatricians, and nutritionists, good outcomes can be observed.
Neonatal Thyroid Function
Authors: Feingold Shiri B. , Brown Rosalind S.
Published: November 2010

Postnatal changes in thyroid hormone economy reflect the adjustment of the fetus to the extrauterine environment. Thyroid-stimulating hormone (TSH) surges soon after birth, resulting in thyroxine (T4) concentrations that are higher in the first postnatal week than at any other time of life and in circulating triiodothyronine (T3) concentrations that are three to four times higher than in the fetus. In preterm infants born after 31 weeks' gestation, the pattern is similar, although less pronounced; in younger infants, a decrease in TSH may be seen, accompanied by a low T4 concentration. Usually the free T4 concentration is less affected than the total T4. Thyroid hormone synthesis is critically dependent on an adequate prenatal and postnatal supply of iodine, which can paradoxically suppress T4 secretion when present in excess, especially in preterm infants and in the presence of iodine deficiency. Maternal T4 is a critical source of thyroid hormone when the fetus is hypothyroid. Postnatal thyroid function also can be affected by maternally or postnatally administered drugs, maternal TSH receptor antibodies (Abs), and acute illness. Because of the vital role of thyroid hormone in brain development and the importance of early, adequate therapy when thyroid function is impaired, knowledge of normal thyroid function in the neonatal period and factors affecting it are critical for physicians caring for newborns.
Community-Based Priorities for Improving Nutrition and Physical Activity in Childhood
Authors: McCarron David A. , Richartz Ninon , Brigham Steve , White Molly K. , Klein Stephen P. , Kessel Samuel S.
Published: November 2010

Overweight among America's youth has prompted a large response from foundations, government, and private organizations to support programmatic interventions. The architecture for many of these programs was derived from “experts,” whereas the perspective of families, and communities—those most affected and most instrumental in altering behavior—is rarely the driving force. Shaping America's Youth (SAY) was established to assess programs that target nutrition and physical activity and to promote the necessary family and community input. In a 2004 report, SAY documented how community efforts are motivated, funded, structured, and evaluated. It identified discordance between that effort and the opinions of experts. To ensure that the voices of families and communities are integrated into such local and national policies and programs, SAY initiated a unique series of 5-day-long town meetings, input from which was independently statistically analyzed. Across a range of demographics, the results indicated that participants perceive the barriers and solutions similarly. There was broad agreement that the family has primary responsibility, starting with a need to focus on improved quality and duration of family time directed at nutrition and activity. Concurrently they identified needed actions from external sources, including clear and consistent nutrition information; ready access to healthy foods; and a built environment that promotes physical activity. Rather than one-dimensional or governmental solutions, they expressed a need for community-based partnerships integrating health care, education, environment, government, and business. Although this citizen-engagement process did not identify specific actions, it defined basic steps that communities must integrate into future approaches.
Evaluation of the Bone Healing Process Utilizing Platelet-Rich Plasma Activated by Thrombin and Calcium Chloride: A Histologic Study in Rabbit Calvaria
Authors: Betoni-Junior Walter , Dechichi Paula , Esteves Jônatas Caldeira , Zanetta-Barbosa Darceny , Magalhães Aparecido Eurípedes Onório
Published: November 2010

To evaluate the bone healing of defects filled with particulate bone graft in combination with platelet-rich plasma (PRP), added with a mixture of calcium chloride and thrombin or just calcium chloride. Two 5-mm bone defects were created in the calvaria of 24 rabbits. Each defect was filled with particulate bone graft and PRP. In one defect the PRP was activated by a mixture of calcium chloride and thrombin; in the other, PRP was activated by calcium chloride only. The animals were euthanized 1, 2, 4, and 8 weeks after the surgeries, and the calvaria was submitted to histologic processing for histomorphometric analysis. The qualitative analysis has shown that both defects presented the same histologic characteristics so that a better organized, more mature, and well-vascularized bone tissue was noticed in the eighth week. A good bone repair was achieved using either the mixture of calcium chloride and thrombin or the calcium chloride alone as a restarting agent of the coagulation process.
Treatment Planning and Sequence for Implant Therapy in a Young Adult With Generalized Aggressive Periodontitis
Authors: Bidra Avinash S. , Shaqman Murad
Published: November 2010

Treatment planning for full-mouth rehabilitation in patients with generalized aggressive periodontitis often requires a staged approach. Few articles have addressed treatment planning and sequencing issues in this patient population. This report describes the multidisciplinary management of a young adult by a combination of periodontal and implant therapy and rehabilitation with fixed prostheses. At a 2-year follow-up, the patient's periodontal health and peri-implant conditions were stable. Prosthodontic rationale and treatment planning concepts in a patient with multiple challenges are discussed.
Peri-Implant Defect Augmentation With Autogenous Bone: A Study in Beagle Dogs
Authors: Al-Sulaimani Asala F. , Mokeem Sameer A. , Anil Sukumaran
Published: November 2010

This study evaluates the success of immediate endosseous implants placed along with autogenous bone graft to fill the peri-implant gap. Thirty-two implants were inserted in 8 beagle dogs. The right and left lateral incisors in the maxilla and the mandible of all animals were extracted, and immediate postextraction implants were placed. In the control sites, no bone grafts or barrier membranes were used. In the contralateral experimental site, autogenous bone graft was used. The implants were retrieved with the jawbone for histomorphometric studies. The histomorphometric measurements were carried out using a computerized image analysis system. All implants were covered by compact, mature bone under examination in light microscopy. A high bone-implant contact percentage and bone density was observed at both grafted and nongrafted implant sites. The sites filled with autogenous bone graft showed a significantly higher crestal bone level and bone density compared to the nonfilled sites. The observations of the study emphasize that the filling of the peri-implant bone defects with autogenous bone grafts showed a better outcome compared to unfilled defects.
Influence of Etiologic Factors in Peri-Implantitis: Literature Review and Case Report
Authors: Cortes Arthur Rodriguez Gonzalez , Ferraz Paulo , Tosta Mauro
Published: November 2010

Peri-implantitis is a pathology that has been described in many clinical studies and case reports. However, it is still not clear how the roles of its etiologic agents work. This article is based on a review of the literature and a case report. It aims to offer data related to the factors that cause this pathology, and to analyze how these factors interact, leading to the contamination of the peri-implant tissue.
Estimating Demand for Urban Fisheries Management: an Illustration of Conjoint Analysis as a Tool for Fisheries Managers
Authors: Mahasuweerachai Phumsith , Boyer Tracy A. , Balsman Dane M. , Shoup Daniel E.
Published: November 2010

This paper illustrates the use of discrete-choice analysis, a nonmarket valuation technique, for assessing the effect of different management or fishing site quality variables on demand for urban fisheries. The study was carried out in three fishing ponds that are a part of the Close-to-Home Fishing Program in the Oklahoma City metropolitan area. We found that, on average, anglers were willing to pay more for physical infrastructure improvements, such as flush toilets ($3.81/year) and docks ($1.28/year), than for having larger channel catfish Ictalurus punctatus stocked (.23/year for a 4-in increase). Willingness to pay for improvements to the ponds was less for minority anglers than for other anglers. Having relative values for potential management changes for a fishery helps to inform fisheries managers about what characteristics are valued most by anglers, allowing managers to better serve the anglers' interest and to justify the costs of implementing these changes.
Dynamics of Fishing Gear and Spatial Allocation of Fishing Effort in a Multispecies Fleet
Authors: Monroy Carmen , Salas Silvia , Bello-Pineda Javier
Published: November 2010

Optimization of fishing effort allocation and efficient deployment of fishing gear are necessary for successful management of multispecies fisheries. Campeche Bank, located in the southwestern Gulf of Mexico, provides an opportunity to understand fishing effort and fishing gear dynamics through the analysis of the fishing operations of a semi-industrial fleet and obtain insights into how to identify management units for these types of fisheries. We analyzed the operation of this fleet over 4 years by splitting it into groups and then fully describing the behavior of each one. Our analysis was based on two data sets, including records from logbooks (8,390 fishing trips) and interviews with skippers from fishing vessels at the landing ports (882 trips). We used multivariate statistical techniques (SIMPER, hierarchical cluster analysis, and nonmetric multidimensional scaling analysis) to define targeted species and define the groups (métiers). Geographical information systems tools helped us to identify the spatial distribution of fishing effort by gear on an annual and monthly basis. We identified four different groups that resulted from the combination of fishing gear, target species, and fishing zones. Shifting behavior between gears and target species was a fishing strategy developed by several vessels, and technological interactions were evident between two gear types that employ longlines. Spatial allocation of fishing effort indicated a preference for certain fishing zones by vessels that operated two of the four gears. This pattern was consistent throughout the years studied; however, monthly differences did exist. The results provide information to identify management units in multispecies fisheries through the identification of métiers and the understanding of fishing strategies.
Factors Influencing Impingement at 15 Ohio River Power Plants
Authors: King Ronald G. , Seegert Greg , Vondruska Joe , Perry Elgin S. , Dixon Douglas A.
Published: November 2010

Impingement abundance monitoring was conducted at 15 Ohio River power plants as part of the Ohio River Ecological Research Program. Impingement rates were compared with environmental, power plant design, and operational factors that varied within and among the power plants, including water temperature, river flow and stage, change in flow and stage during the sampling events, volume of cooling water pumped, design pumping capacity, approach velocity, location of the intakes along the river, intake type, and intake configuration. The study demonstrated similarities in species composition, size distributions, and seasonal patterns over nearly 1,400 river kilometers of the Ohio River, results that were consistent with studies conducted nearly 30 years earlier. Dramatic annual differences in impingement rates during the 2-year study indicated that impingement is largely a function of the recruitment levels of juvenile gizzard shad Dorosoma cepedianum, threadfin shad D. petenense, and freshwater drum Aplodinotus grunniens, measures that fluctuate widely in the Ohio River based on long-term monitoring data and unpredictably based on current knowledge of the impingement process. The study also showed that most physical variables had little or no effect on impingement rates. Water temperature was identified through multiple regression analyses as the most important physical variable, with impingement tending to increase during the winter. Actual pumping rate during sampling events—the only factor evaluated that is under the direct control of the participating power plants—was one of the least important factors affecting impingement rates.
Matching Management to Biological Scale: Connectivity among Lacustrine Brook Trout Populations
Authors: Addison Peter A. , Wilson Chris C.
Published: November 2010

Determining appropriate spatial scales for managing fisheries is a key element of sustainable management. For inland fisheries, management or harvest regulations are often implemented as general regional guidelines or on a lake-by-lake basis. Wild lacustrine brook trout Salvelinus fontinalis from four waterbodies in the Galipo River watershed of Algonquin Provincial Park, Ontario, were used as a model system to determine the extent of population structure among lakes and to identify appropriate scale(s) for managing inland brook trout fisheries. Individual multilocus genotypes were measured using 10 microsatellite loci and were used to characterize movement and gene flow among lakes. Both population- and individual-based analyses showed very little genetic structure among all pairs of waterbodies, suggesting high levels of movement and gene flow between all pairs of lakes. Varying levels of limited genetic structure between pairs of lakes indicate that gene flow may not be uniform within the study system. These results suggest that contrary to previous studies, local watersheds may be the most appropriate management scale for lacustrine brook trout populations in watersheds where physical characteristics provide the potential for migration and gene flow.
Comparison of Electrofishing and Snorkeling Mark–Recapture Estimation of Detection Probability and Abundance of Juvenile Steelhead in a Medium-Sized River
Authors: Korman Josh , Decker A. Scott , Mossop Brent , Hagen John
Published: November 2010

We compared nighttime electrofishing- and snorkeling-based mark–recapture methods for estimating the detection probability and abundance of juvenile steelhead Oncorhynchus mykiss in the Cheakamus River, British Columbia. The reliability of abundance estimates largely depends on the precision and accuracy of detection probability (the fraction of marked individuals detected) as well as a few key assumptions of closed population models that we evaluated in this study. There was minimal bias (−2.5%) in diver estimates of the fork lengths of juvenile steelhead, and the relationship between measured and estimated fork lengths was very precise (r2 = 95%). With a hierarchical Bayesian model, estimates of the detection probability for smaller juveniles (40–60 mm) ranged from 0.4 to 0.6 with electrofishing and were near zero with snorkeling. In contrast, snorkeling-based detection probability was 0.6 and independent of size for larger juvenile steelhead (>60 mm) and much greater than that with electrofishing. These results provide strong evidence that there is considerable individual heterogeneity in detection probability driven by fish size for both methods. Owing to these differences, the abundance of age-0 steelhead based on snorkeling was underestimated by 50%, but that of larger, age-1 fish was unbiased and more precise (10-fold) than that based on electrofishing. The use of electrofishing during marking resulted in a substantive reduction in snorkeling-based detection probability during recapture, but the converse was not true. Thus, there is strong evidence of behavioral heterogeneity in detection probability induced by electrofishing, but only when snorkeling is used to detect fish during recapture. The differences in detection probabilities among size-classes and sampling methods were probably driven by differences in concealment behavior, spatial distribution, and fright responses to sampling. Our results indicate that snorkeling is the better way to estimate abundance for larger juvenile steelhead, whereas electrofishing is preferred for smaller fish.
Effectiveness of Night Snorkeling for Estimating Steelhead Parr Abundance in a Large River Basin
Authors: Hagen John , Decker Scott , Korman Josh , Bison Robert G.
Published: November 2010

The refinement of methodologies for estimating the abundance of juvenile salmonids in small streams has been an important area of fisheries research, but the development of methods suitable for larger streams has received insufficient attention. Using a novel approach for obtaining marked populations of fish, we evaluated the effectiveness of night snorkeling counts for estimating the abundance of steelhead Oncorhynchus mykiss parr in streams within a large river basin. Sampled streams ranged from headwater tributaries with wetted widths of less than 10 m to a large, main-stem river with a wetted width approaching 100 m. Estimates of snorkeling detection probability for steelhead parr were consistently high (overall mean = 0.65) and exhibited moderately low variability among sites (coefficient of variation = 0.24). Detection probability exhibited a dome-shaped relationship to fork length and declined with increasing cross-sectional site area. The high and relatively consistent detection probabilities we estimated indicate that night snorkeling can be an effective technique for estimating the basinwide abundance of steelhead parr.
Evaluating Surrogacy of Hatchery Releases for the Performance of Wild Yearling Chinook Salmon from the Snake River Basin
Authors: Buchanan Rebecca A. , Skalski John R. , Giorgi Albert E.
Published: November 2010

The combined juvenile and adult detections of Snake River yearling Chinook salmon Oncorhynchus tshawytscha implanted with passive integrated transponder tags migrating through the hydroelectric facilities in the Federal Columbia River Power System were analyzed using the ROSTER statistical release–recapture model. This model was used to estimate the downriver survival of smolts, ocean survival, adult passage success, and smolt-to-adult ratios (SARs) for wild and hatchery-reared Chinook salmon released as yearlings in the Snake River basin from 1996 through 2004. Estimates from wild and hatchery release groups were compared to assess the extent to which hatchery stocks may be used as surrogates for endangered wild stocks. Wild release groups included both spring and summer Chinook salmon runs, while hatchery release groups were separated by run (spring versus summer). Overall, there was a significant difference between estimates from wild release groups and hatchery spring-run release groups for all survival measures except ocean survival but not between wild release groups and hatchery summer-run release groups. Estimates of adult passage success and SAR were significantly higher for wild groups than for hatchery spring groups. There was high correlation (r > 0.8) between estimates from wild fish and both spring and summer hatchery fish for all measures except adult passage success within a calendar year. It appears that hatchery summer Chinook salmon stocks from the Snake River basin may be used as surrogates for wild stocks for measuring survival on large temporal and spatial scales (e.g., annual basinwide measures). Because of differences between survival estimates from wild fish and hatchery spring fish, hatchery spring Chinook salmon may be used as an index for trends in the survival of wild stocks but not as direct surrogates.
Comparison of Mortality and Diet Composition of Pellet-Reared Advanced-Fingerling and Early-Cohort Age-0 Wild Largemouth Bass through 90 Days Poststocking at Lake Seminole, Florida
Authors: Pouder William F. , Trippel Nicholas A. , Dotson Jason R.
Published: November 2010

Advanced-fingerling Florida largemouth bass Micropterus salmoides floridanus (N = 18,263; mean total length = 77 mm) reared on pellet feed specifically formulated for largemouth bass were tagged with coded wire tags and stocked on 28 May 2008 in a 162-ha lobe of hypereutrophic Lake Seminole (283 ha) in Pinellas County, Florida. We compared mortality and diet composition of stocked advanced-fingerling and early-cohort wild age-0 largemouth bass through 90 d poststocking. Our mortality estimates were similar for stocked (84%) and early-cohort age-0 wild largemouth bass (95%) based on the slope of a catch curve. We used a percent similarity index (PSI) to evaluate the diet composition of stocked and early-cohort wild age-0 largemouth bass. Diet composition was generally similar between stocked and wild fish, although the greatest dissimilarity occurred at 7 d poststocking (PSI = 0.48). Pearson chi-square analysis indicated that early-cohort age-0 wild largemouth bass had a significantly higher frequency of diets containing fish than stocked largemouth bass and that stocked fish had a significantly higher frequency of empty stomachs at 7 d poststocking. An inability to transition to natural prey, stresses from the stocking process, and/or other factors not measured in this study (e.g., predation) probably contributed to the mortality of stocked fish through 90 d poststocking. We recommend that hatchery managers and biologists conduct further research on the hatchery fish rearing protocol (e.g., transition to natural prey and habitat complexity in raceways) that may lead to increased survival of stocked advanced-fingerling largemouth bass.
Modified Sampling Design for Age-0 Fish Electrofishing at Beach Habitats
Authors: Janáč Michal , Jurajda Pavel
Published: November 2010

Fright bias can cause misleading results when sampling age-0 fish in beach habitats. In this study, different sampling methods were tested to reduce fright bias. Experiments using video recordings demonstrated that efficiency was 13% for extension pole electrofishing (EPE), 47% for thrown anode electrofishing (TAE), and 100% for pre-positioned anode electrofishing (PAnE). We propose a modified PAnE design for sampling age-0 fish that would not be excessively time consuming. The modified PAnE sampling design was then tested against EPE, TAE, and fine-mesh seine netting (SN). We found that PAnE sampled significantly more species and individuals than EPE and TAE. Assemblage structure sampled by PAnE differed significantly from that sampled by EPE, TAE, and SN; the difference was more substantial relative to SN than to EPE or TAE. Assemblages sampled by EPE and TAE had a lower representation of common bleak Alburnus alburnus, white-fin gudgeons Gobio albipinnatus, common dace [also known as Eurasion dace] Leuciscus leuciscus, and roach Rutilus rutilus compared with PAnE. Assemblages sampled by SN had a lower representation of white-fin gudgeons, chub [also known as European chub] L. cephalus, common barbels Barbus barbus, and common nase Chondrostoma nasus compared with PAnE. No difference was found in length distributions of fish captured by PAnE and the other methods. Although the modified PAnE design demonstrated significantly reduced time consumption, it was still more time consuming than the other sampling methods. The apparent advantages of PAnE were its high relative efficiency (higher number of fish/min of sampling relative to the other methods) and its minimization of the bias and selectivity caused by the investigator's presence or action.
A Regional Approach for Monitoring Salmonid Status and Trends: Results from a Pilot Study in Coastal Mendocino County, California
Authors: Gallagher Sean P. , Wright David W. , Collins Barry W. , Adams Peter B.
Published: November 2010

In coastal California, many evolutionarily significant units (ESUs) of Chinook salmon Oncorhynchus tshawytscha, coho salmon O. kisutch, and steelhead O. mykiss are listed under the federal Endangered Species Act (ESA). Monitoring species status at the ESU or ESU subdivision scale requires specialized sampling. The purposes of this study were (1) to evaluate abundance estimated from a generalized random tessellation stratified (GRTS) design and compare the results with those from a more intensive stratified random monitoring program and (2) to evaluate the statistical power of the design to detect population trends. This 3-year pilot study considered five Mendocino County streams as an example region of coastal California to evaluate a two-stage sampling approach for monitoring regional escapement. Under this scheme, regional redd surveys (stage 1) were conducted in stream reaches in a GRTS sampling design. Ten percent of anadromous habitat was sampled in year 1 and 10–35% in years 2 and 3. Spawner:redd ratios were derived from smaller-scale census watersheds (stage 2) where “true” escapement was estimated using capture–recapture methods. Regional escapement was then estimated from expanded redd counts, calibrated by spawner:redd ratios. As an alternative, more intensive method for estimating escapement, three survey streams were also sampled in a stratified random design. The results, added to counts from the census basins, produced more rigorous “sum-of-streams” estimates for comparison with the GRTS sampling. Redd counts and the resulting escapement estimates were reliable for regional monitoring. The GRTS and sum-of-streams estimates overlapped, and the variation in the 95% confidence intervals did not change after 15%. Our results suggest that a sample size of 15% or 41 or more reaches (whichever results in fewer survey reaches) should have adequate precision and statistical power to detect regional trends in salmon populations. We recommend that this monitoring approach be applied at regional spatial scales consistent with ESA recovery planning efforts.
Performance of Spawner Survey Techniques at Low Abundance Levels
Authors: Gallagher Sean P. , Adams Peter B. , Wright David W. , Collins Barry W.
Published: November 2010

Population monitoring is essential to know whether coastal California's Endangered Species Act–listed Chinook salmon Oncorhynchus tshawytscha, coho salmon O. kisutch, and steelhead O. mykiss stocks are progressing toward recovery. In coastal California, salmonids are at the southern edge of their range, and this one of many reasons they are not abundant. This provides unique challenges for monitoring, as different survey methods will result in estimates with different levels of accuracy and precision, which are important for evaluating population trends. For this study we intensively monitored three Mendocino County watersheds to evaluate the reliability of two-stage data for monitoring regional escapement. Under this scheme, regional spawning surveys (stage 1) were calibrated with data from intensively monitored watersheds (stage 2), where escapement was estimated using capture–recapture methods, redd counts, and fish counts. The objective of the study was to evaluate the quality of the stage 2 data for calibrating regional surveys. We evaluated the precision of live-fish capture–recapture estimates and compared these estimates with estimates derived from spawning survey data using carcass capture–recapture, area under the curve (AUC), and redd counts. Live-fish capture–recapture produced escapement estimates with narrower 95% confidence bounds where permanent structures were used to capture fish. Redd counts converted to fish numbers using spawner: redd ratios were chosen for the regional salmonid monitoring method because they were reliable, economical, and less intrusive. Converted redd counts were statistically and operationally similar to live-fish capture–recapture estimates but required fewer resources. The AUC estimates were less reliable than converted redd counts and live-fish capture–recapture methods due to the sensitivity of the estimates of residence time and observer efficiency. Finally, we found that carcass capture–recapture methods were operationally unsuccessful in coastal California streams. On the basis of our results, we recommend that annual spawner: redd ratios from intensively monitored watersheds be used to calibrate redd counts for regional status and trend monitoring of California's coastal salmonids.