bluuebunny/crossref_metadata_2025 huggingface dataset:
Opposite changes of whole‐soil vs. pools C : N ratios: a case of Simpson's paradox with implications on nitrogen cycling
Authors: PIÑEIRO GERVASIO , OESTERHELD MARTÍN , BATISTA WILLIAM B. , PARUELO JOSÉ M.
Published: May 2006

Ecosystem and soil scientists frequently use whole soil carbon:nitrogen (C : N) ratios to estimate the rate of N mineralization from decomposition of soil organic matter (SOM). However, SOM is actually composed of several pools and ignoring this heterogeneity leads to incorrect estimations since the smaller pools, which are usually the most active, can be masked by the larger pools. In this paper, we add new evidence against the use of C : N ratios of the whole soil: we show that a disturbance can decrease the whole‐soil C : N ratio and yet increase C : N ratios of all SOM pools. This curious numerical response, known as Simpson's paradox, casts doubt on the meaning of frequently reported whole‐soil C : N changes following a disturbance, and challenges the N mineralization estimates derived from whole‐soil C : N ratio or single‐pool modeling approaches. Whole‐soil C : N ratio may not only hide features of the labile SOM pool, but also obscure changes of the large recalcitrant SOM pools which determine long‐term N availability.
Thermal niche, large‐scale movements and implications of climate change for a critically endangered marine vertebrate
Authors: McMAHON CLIVE R. , HAYS GRAEME C.
Published: May 2006

Climate change is expected to have a number of impacts on biological communities including range extensions and contractions. Recent analyses of multidecadal data sets have shown such monotonic shifts in the distribution of plankton communities and various fish species, both groups for which there is a large amount of historical data on distribution. However, establishing the implications of climate change for the range of endangered species is problematic as historic data are often lacking. We therefore used a different approach to predict the implications of climate change for the range of the critically endangered planktivourous leatherback turtle (Dermochelys coriacea). We used long‐term satellite telemetry to define the habitat utilization of this species. We show that the northerly distribution limit of this species can essentially be encapsulated by the position of the 15°C isotherm and that the summer position of this isotherm has moved north by 330 km in the North Atlantic in the last 17 years. Consequently, conservation measures will need to operate over ever‐widening areas to accommodate this range extension.
Does the modality principle hold for different media? A test of the method‐affects‐learning hypothesis
Authors: Moreno R.
Published: May 2006

Abstract
Does the modality of instructional messages affect learning? How does it affect different media? In this paper, I offer an answer to these questions by first proposing a theoretical framework from which effective instructional methods can be derived. Then, I report a set of studies where one method, the modality principle, was tested across different media and found to produce significant learning benefits. Based on the findings and those of a recent meta‐analysis of modality effects, I suggest future research directions to examine method and media contributions to learning.
Ontogenetic shift from facilitation to competition in a desert shrub
Authors: MIRITI MARIA N.
Published: May 2006

Spatiotemporal responses to habitat conditions are important components of plant population and community dynamics. Plant stage or size is a common predictor of plant performance for a range of ecological conditions, including responses to neighbours. Plant response to local conditions varies from seedling establishment through to senescence, with strong implications for population regulation.

I investigated size‐dependent responses to near adult neighbours among a uniquely quantitative sample of mapped juvenile and adult bur‐sage (Ambrosia dumosa), a common shrub in the Colorado Desert of California.

Analyses of juvenile establishment and survival for two 5‐year census periods from 1984 to 1989 and 1989 to 1994 determined that germination and survival was greater for juveniles located under adults compared with away from adults. However, analyses of neighbour effects on growth of plants from the 1984 cohort showed that near adult neighbours improved juvenile growth over the 10‐year interval from 1984 to 1994, but reduced adult growth.

A size‐dependent, ontogenetic shift occurs because neighbouring adult plants significantly improve the demographic performance of juveniles, but diminish that of larger established plants.

The ontogenetic niche shift may be a useful framework to describe such differential responses of juvenile and adult plants. The utility of this framework is that responses to spatial and temporal variability in the environment are clearly demonstrated through ontogenetic constraints on plant performance, which provide an alternative mechanism of coexistence within and between species.
The virtual lecture hall: utilisation, effectiveness and student perceptions
Authors: Cramer Kenneth M. , Collins Kandice R. , Snider Don , Fawcett Graham
Published: May 2006

We presently introduce the Virtual Lecture Hall (VLH), an instructional computer‐based platform for delivering Microsoft PowerPoint slides threaded with audio clips for later review. There were 839 male and female university students enrolled in an introductory psychology class who had access to review class lectures via the VLH. This tool was made available through the course website following the first midterm. Approximately 20% used the resource, and 18% completed a five‐item survey tapping their perceptions of whether the VLH enhanced learning or increased grades; and whether they wanted the resource in other courses. The total number of student accesses was calculated, as was the total duration (in minutes) that students used the VLH. After accounting for initial midterm test score differences, results showed that students who used the VLH for 100 minutes or more scored, on average, 15% higher in their second midterm. The student perceptions of the VLH were also highly favourable. Directions for future research in resource development and implications for educators are also discussed.
Joint Determination of the State Dimension and Autoregressive Order for Models with Markov Regime Switching
Authors: Psaradakis Zacharias , Spagnolo Nicola
Published: May 2006

Abstract. This paper is concerned with the problem of joint determination of the state dimension and autoregressive order of models with Markov‐switching parameters. A model selection procedure is proposed which is based on optimization of complexity‐penalized likelihood criteria. The efficacy of the procedure is evaluated by means of Monte Carlo experiments.
On Hypotheses Testing for the Selection of Spatio‐Temporal Models
Authors: Antunes Ana Mónica C. , Rao Tata Subba
Published: May 2006

Abstract. Several models have been proposed in recent years for analysing spatial data and also, to some extent, spatio‐temporal data. One of the important problems, namely the choice of an appropriate model for describing real data sets, remains unsolved. Here we consider the analysis of spatio‐temporal processes from which observations over space and time are available. We propose statistical tests for discriminating between space–time autoregressive processes and multivariate autoregressive processes. The sampling properties of the proposed tests are considered. We illustrate the methods with a real example. We use the above tests to find the best model to describe spatio‐temporal variations of hourly carbon monoxide measurements at four locations in London in January 2004.
The Dynamics of Returns to Education in Kenyan and Tanzanian Manufacturing*
Authors: Söderbom Måns , Teal Francis , Wambugu Anthony , Kahyarara Godius
Published: May 2006

We use micro data on manufacturing employees in Kenya and Tanzania to estimate returns to education and investigate the shape of the earnings function in the period 1993–2001. In Kenya, there have been long‐run falls in the returns to education while for Tanzania there is evidence of rising returns in the 1990s. The earnings functions are convex for both countries and this result is robust to endogeneity. Convexity may be part of the explanation as to how rapid expansion of education in Africa has generated so little growth if expansion has been concentrated at lower levels of education.
Revisiting the Past and Settling the Score: Index Revision for House Price Derivatives
Authors: Clapham Eric , Englund Peter , Quigley John M. , Redfearn Christian L.
Published: May 2006

This article examines index revision in measuring the prices for owner‐occupied housing. We consider revision in the context of equity insurance and the settlement of futures contracts. The usefulness of aggregate housing price indexes in these contexts requires stability as they are extended. Methods that are subject to substantial revision raise questions about the viability of derivatives markets. We find that the most widely used house price indexes are not equally exposed to volatility in revision. Hedonic indexes appear to be substantially more stable than repeat‐sales indexes and are not prone to the systematic downward revision found in the repeat‐sales indexes.
Housing Tenure Choice in Australia and the United States: Impacts of Alternative Subsidy Policies
Authors: Bourassa Steven C. , Yin Ming
Published: May 2006

This article compares the homeownership rates of young households in Australia and the United States and evaluates the impacts of the two countries' different approaches to subsidizing homeownership. Since about 1950, Australia's rate of homeownership has consistently been higher than that of the United States. The homeownership rate for young adults is also significantly higher in Australia. While the United States allows mortgage interest and property taxes to be deducted from income for tax purposes, Australia has provided cash subsidies for down payments and mortgage payments. We conclude that differences in housing costs and household characteristics do not explain differences in ownership rates. We also conclude that differences in subsidy policies have only a minor impact on ownership rates.
Acute lipoprotein lipase deletion in adult mice leads to dyslipidemia and cardiac dysfunction
Authors: Noh Hye-Lim , Okajima Kazue , Molkentin Jeffery D. , Homma Sunichi , Goldberg Ira J.
Published: May 2006

The most energy-requiring organ in the body, the cardiac muscle, relies primarily on lipoprotein-derived fatty acids. Prenatal loss of cardiac lipoprotein lipase (LPL) leads to hypertriglyceridemia, but no cardiac dysfunction, in young mice. Cardiac specific loss of LPL in 8-wk-old mice was produced by a 2-wk tamoxifen treatment of MerCreMer (MCM)/ Lplflox/flox mice. LPL gene deletion was confirmed by PCR analysis, and LPL mRNA expression was reduced by ∼70%. One week after tamoxifen was completed, triglyceride was increased with LPL deletion, 162 ± 53 vs. 91 ± 21 mg/dl, P < 0.01. Tamoxifen treatment of Lplflox/flox mice did not cause a significant increase in triglyceride levels. Four weeks after tamoxifen, MCM/ Lplflox/flox mice had triglyceride levels of 190 ± 27 mg/dl, similar to those of mice with prenatal LPL deletion. One week after the tamoxifen, MCM/ Lplflox/flox, but not Lplflox/flox, mice had decreases in carnitine palmitoyl transferase I mRNA (18%) and pyruvate dehydrogenase kinase 4 mRNA (38%). These changes in gene expression became more robust with time. Acute loss of LPL decreased ejection fraction and increased mRNA levels for atrial natriuretic factor. Our studies show that acute loss of LPL can be produced and leads to rapid alteration in gene expression and cardiac dysfunction.
Role of acetaminophen in acute myocardial infarction
Authors: Leshnower Bradley G. , Sakamoto Hiroaki , Zeeshan Ahmad , Parish Landi M. , Hinmon Robin , Plappert Theodore , Jackson Benjamin M. , Gorman Joseph H. , Gorman Robert C.
Published: May 2006

Acetaminophen, the active ingredient in Tylenol, is a widely used drug that is well known for its analgesic and antipyretic properties. Acetaminophen is a commonly used alternative to nonsteroidal anti-inflammatory drugs, which have recently been demonstrated to increase mortality after acute myocardial infarction (AMI). The safety and potential cardioprotective properties of acetaminophen in the setting of AMI have recently been investigated; however, the results from these studies have been inconclusive. Using both large (ovine) and small (rabbit) collateral-deficient animal models, we studied the effects of acetaminophen in the setting of reperfused AMI. In both species we studied the effects of acetaminophen on myocardial salvage and ventricular function. Additionally, we studied the effects of acetaminophen on myocardial perfusion in sheep and on myocyte apoptosis in rabbits. Sixteen sheep and twenty-two rabbits were divided into two groups and administered acetaminophen or a vehicle before undergoing ischemia and reperfusion. The ischemic period was 60 min in sheep and 30 min in rabbits. All animals were reperfused for 3 h. There were no significant differences observed in myocardial perfusion, myocyte apoptosis, or infarct size in acetaminophen-treated animals. Acetaminophen increased cardiac output and mean arterial pressure before ischemia in sheep but had no effect on any other hemodynamic parameter. In rabbits, no effect on cardiac output or blood pressure was detected. These results support the role of acetaminophen as a safe drug in the postmyocardial infarction setting; however, no significant cardioprotective effect of the drug could be demonstrated.
Glucose Withdrawal Induces Oxidative Stress followed by Apoptosis in Glioblastoma Cells but not in Normal Human Astrocytes
Authors: Jelluma Nannette , Yang Xiaodong , Stokoe David , Evan Gerard I. , Dansen Tobias B. , Haas-Kogan Daphne A.
Published: May 2006

Tumor cells rely preferentially on anaerobic glycolysis rather than on respiration for ATP generation, a phenomenon known as the Warburg effect. We explored the effects of glucose withdrawal on glioblastoma multiforme–derived cell lines and their nontransformed counterparts, normal human astrocytes. We found that glucose withdrawal induces extensive apoptosis in glioblastoma multiforme cells but not in normal astrocytes. In all cells examined, ATP levels are sustained on glucose withdrawal due to elevation of fatty acid oxidation and ensuing respiration; however, we show that oxidative stress generated in the mitochondrial respiratory chain is the direct cause of cell death in glioblastoma multiforme cells. Oxidative stress that only occurs in glioblastoma multiforme cells underlies the selective susceptibility to glucose withdrawal–induced apoptosis documented in the malignant cells. This study implicates glycolysis as a potentially efficient and selective target for glioblastoma multiforme treatment. (Mol Cancer Res 2006;4(5):319–30)
Interactive Feedback between ENSO and the Indian Ocean
Authors: Kug Jong-Seong , Kang In-Sik
Published: May 2006

A feedback process of the Indian Ocean SST on ENSO is investigated by using observed data and atmospheric GCM. It is suggested that warming in the Indian Ocean produces an easterly wind stress anomaly over Indonesia and the western edge of the Pacific during the mature phase of El Niño. The anomalous easterly wind in the western Pacific during El Niño helps a rapid termination of El Niño and a fast transition to La Niña by generating upwelling Kelvin waves. Thus, warming in the Indian Ocean, which is a part of the El Niño signal, operates as a negative feedback mechanism to ENSO. This Indian Ocean feedback appears to operate mostly for relatively strong El Niños and results in a La Niña one year after the mature phase of the El Niño. This 1-yr period of phase transition implies a possible role of Indian Ocean–ENSO coupling in the biennial tendency of the ENSO. Atmospheric GCM experiments show that Indian Ocean SST forcing is mostly responsible for the easterly wind anomalies in the western Pacific.
The Role of MNEs in Community Development Initiatives in Developing Countries
Authors: Eweje Gabriel
Published: May 2006

Multinational enterprises (MNEs) have long had a reputation of not doing enough for their host communities in developing countries. This study critically examines the role of MNEs in community development initiatives in developing countries, using the Nigeria oil industry and the South African mining industry as case study. Specifically, the study assessed the usefulness of MNE-supported community development projects as a means of demonstrating corporate social responsibility. The findings suggest that expectations for community development projects are greater in developing countries. This study introduced new information on MNEs'local development programs that were drawn from interviews with MNEs'managers, government officials, and local communities.
Normative Myopia, Executives' Personality, and Preference for Pay Dispersion
Authors: Orlitzky Marc , Swanson Diane L. , Quartermaine Laura-Kate
Published: May 2006

In this preliminary study, the authors extend Swanson's concept of normative myopia (the propensity of executives to downplay or ignore the values at stake in their decision making) by using it as a point of reference for studying executives' preference for high pay dispersion. Specifically, the authors designed a survey to examine hypothesized relationships among myopia, personality, and executives' preference for highly stratified organizational pay structures. Data from 133 executive respondents suggest that myopic executives tend to prefer top-heavy compensation systems. In addition, the findings point to an inverse relationship between the personality factor Agreeableness and normative myopia, with the former offsetting the latter. The authors reject the alternative hypothesis that gender influences both agreeableness and myopia and conclude with some implications for business and society, including Swanson's proposition that normative myopia at the top contributes to a neglectful form of corporate social performance.
Strategy and Legitimacy
Authors: Trullen Jordi , Stevenson William B.
Published: May 2006

This study shows that firms respond in strategic ways to institutional pressures that stem from social scandals. Through the formal analysis of the historical narrative of events, the authors studied how seven pharmaceutical companies reacted over the years to accusations of being socially irresponsible in dealing with the HIV virus in Africa. The analysis shows that institutional and task environmental factors interact to precipitate pharmaceutical companies' reactions. Although firms' behaviors were indeed affected by institutional pressures exerted by activist groups and the media, they did not passively adapt to these pressures. Instead, they decoupled their core technical activities from their policy announcements (by delaying the implementation of promised concessions) and used institutional pressure in the organizational field as a way of pursuing their own economic interests.
Residual Unionism and Renewal: Organized Labour in Mozambique
Authors: Webster Edward , Wood Geoffrey , Mtyingizana Beata , Brookes Michael
Published: May 2006

This article provides a critical review of the nature and state of union organization in Mozambique, based on a survey of employees in the country™s two principal urban centres, Maputo and Beira. The findings of the survey underscore the point that the ability of unions to retain a physical presence in adverse circumstances does not necessarily represent a reflection of union strength. Whilst retaining a residual presence in many workplaces, Mozambican unions have battled to cope with changes in the external labour market and a greatly altered political climate. In most cases, they have proved equally incapable of challenging the authority of management and of articulating viable alternatives to the neo-liberal orthodoxy. There is a vital need to enhance the quality of unionism and the service provided at existing workplaces, and reconcile the needs of very different groupings of workers, not only within Mozambique, but across the continent; African unions can no longer count on the patronage of governments or on favourable market conditions within specific sectors.
Immaturity
Authors: Thorpe Richard , Gold Jeff , Holt Robin , Clarke Jean
Published: May 2006

We introduce conceptions of ‘enacted cognition’,‘practical authorship’ and ‘maturity’ that help us to investigate entrepreneurship as an activity. The first two stem from social constructionist perspectives on patterns of recognition and the articulation of knowledge respectively (Shotter, 1993; Vygotsky, 1986). The third is found in Kant’s (1784/1991) essay ‘What is Enlightenment?’ By combining these, our research highlights those factors that prevent entrepreneurs developing maturity and so embedding their ideas within the wider economic and social activities of their community. A novel e-postcard methodology is employed with 44 UK entrepreneurs to investigate these factors from the entrepreneurs’ own judgements. Implications for the development of a new methodology, for the conceptualization and development of entrepreneurial activity and learning among small firm managers, and for policy are discussed.
Whose Story is it Anyway?
Authors: Hamilton Eleanor
Published: May 2006

The role of women in family business is relatively under-investigated. This article illuminates complex relationships in a family business context, putting the family at the heart of the research as opposed to an individual owner-manager. It draws on narrative accounts of establishing a family business, as told by the founders and by the succeeding generation in three family businesses. Some of the existing literature conceptualizes women in family business as marginalized through the forces of patriarchy or paternalism. The narratives presented in this article point to alternative gender discourses and practices, and to evidence of clear resistance to patriarchy. In so doing it begins to identify the conditions under which patriarchy might be challenged in family businesses.
Technical Errors during Medial Patellofemoral Ligament Reconstruction Could Overload Medial Patellofemoral Cartilage
Authors: Elias John J. , Cosgarea Andrew J.
Published: May 2006

Background

The influence of reconstruction of the medial patellofemoral ligament on the patellofemoral force and pressure distributions has not yet been investigated.

Hypothesis

Technical errors can cause tension to develop within a reconstructed medial patellofemoral ligament, which will adversely alter the normal patellofemoral force distribution by increasing the load applied to the medial cartilage.

Study Design

Controlled laboratory study.

Methods

Four computational knee models were used to simulate knee function from 30° to 90° of flexion with (1) an intact medial patellofemoral ligament, (2) an anatomically correct reconstruction using a double hamstring tendon autograft, (3) a 5-mm proximally malpositioned femoral attachment site, (4) a graft that is 3 mm shorter than the intact medial patellofemoral ligament, and (5) combined proximal malpositioning and a short graft.

Results

The results were similar for the intact and anatomically reconstructed medial patellofemoral ligament. Proximal malpositioning of the femoral attachment and using a short graft increased the graft tension during flexion, which decreased the lateral force and the lateral tilt moment acting on the patella. When a short graft was combined with proximal malpositioning, the compressive force applied to the medial cartilage at least doubled at low flexion angles, which increased the peak medial pressure by more than 50% at low flexion angles.

Conclusion

When the medial patellofemoral ligament is reconstructed, small errors in graft length and position can dramatically increase the force and pressure applied to medial patellofemoral cartilage.

Clinical Relevance

Overloading the medial cartilage after medial patellofemoral ligament reconstruction could lead to degradation, pain, and arthrosis.
Path of Glenohumeral Articulation Throughout the Rotational Range of Motion in a Thrower's Shoulder Model
Authors: Huffman G. Russell , Tibone James E. , Mcgarry Michelle H. , Phipps Brinceton M. , Lee Yeon Soo , Lee Thay Q.
Published: May 2006

Background

Overhead-throwing athletes have increased external and diminished internal glenohumeral rotation that may alter glenohumeral kinematics.

Purpose

To quantify the kinematic changes present in a cadaveric model of a thrower's shoulder.

Study Design

Controlled laboratory study.

Methods

In 8 fresh-frozen cadaveric shoulders, the rotator cuff and overlying muscles were removed, and the glenohumeral capsule, coracoacromial ligament, and coracohumeral ligament were left intact. The scapula was fixed, and the humerus was placed in 90° of shoulder abduction in a 6 degrees of freedom testing device. A compressive force of 44 N was applied. A thrower's shoulder model was created, and sequential conditions were examined: intact, after anterior stretching, and after the addition of posterior-inferior capsular plication. Kinematic measurements were obtained through a complete range of glenohumeral rotation.

Results

Glenohumeral external rotation increased 16%, from 149° to 173° (P <. 001), after stretching in external rotation and remained increased by 11% to 166° (P <. 001) after posterior-inferior capsular plication. With the addition of the posterior-inferior capsular plication, internal rotation averaged 7°, which was not significantly different from the intact state (11°, P =. 55) or the stretched state (16°, P =. 07). The total glenohumeral rotation after stretching followed by posterior-inferior capsular plication did not differ significantly from intact state (P =. 25). At maximum external rotation, the humeral head apex was shifted posteriorly in the stretched (P =. 003) and plicated (P <. 001) states compared with the intact state. The humeral head apex was posteriorly displaced at 135° and 150° of external rotation compared with the intact condition (P =. 039 and. 049, respectively). In maximum internal rotation, anterior stretching had no significant effect on the humeral head apex position. However, after posterior-inferior capsular plication, the humeral head apex was significantly shifted inferiorly (P =. 005) and anteriorly (P =. 03) in maximum internal rotation compared with the intact state.

Conclusion

Significant changes in glenohumeral motion occur in this model during the simulated late-cocking and follow through phases of throwing. In this model, posterior capsular tightness alters the humeral head position most profoundly during the deceleration and follow-through phases of throwing.
An Analysis of the Causes of Failure in 57 Consecutive Posterolateral Operative Procedures
Authors: Noyes Frank R. , Barber-Westin Sue D. , Albright Jay C.
Published: May 2006

Purpose

To investigate 57 failed posterolateral procedures in 30 consecutive knees to determine factors that may have contributed to the failure.

Study Design

Case series; Level of evidence, 4.

Methods

Thirty patient records were reviewed by an independent surgeon. The index posterolateral operations were done for 13 acute and 17 chronic knee injuries. The anterior cruciate ligament was ruptured in 17 knees, the posterior cruciate ligament was torn in 5 knees, and both cruciates were ruptured in 8 knees. In 25 knees, 46 revision posterolateral procedures had been performed, of which 27 had also failed (in 21 knees). Five knees did not undergo revision of the posterolateral structures.

Results

In 22 knees, multiple factors were identified that most likely contributed to the failure of the posterolateral procedures. The most common factors were nonanatomical graft reconstruction (23 knees), untreated varus malalignment (10 knees), and failure to successfully reconstruct all ruptured knee ligaments, including cruciates (27 knees). Thirty-nine anterior cruciate ligament procedures were done in 24 knees, including 24 primary and 15 revision operations. Seventeen posterior cruciate ligament procedures were done in 13 knees, including 13 primary and 4 revision operations. At the time of writing, 16 of 24 knees had a functional anterior cruciate ligament graft and 5 of 13 had a functional posterior cruciate ligament graft.

Conclusion

The results suggest greater emphasis during the index operation for anatomical graft reconstruction of one or more of the posterolateral structures as necessary, restoration of all ruptured cruciate ligaments, and correction of varus malalignment.
Meniscal Tear Characteristics in Young Athletes with a Stable Knee
Authors: Terzidis Ioannis P. , Christodoulou Anastasios , Ploumis Avraam , Givissis Panagiotis , Natsis Konstantinos , Koimtzis Miltiadis
Published: May 2006

Background

There has been great interest in the literature regarding meniscal tears in unstable knees, but there is not as much information available on stable knees.

Purpose

To report the characteristics of isolated meniscal tears (type and location) in athletes with intact cruciate ligaments.

Study Design

Case series; Level of evidence, 4.

Methods

Arthroscopic surgery was performed on 314 (83.1%) knees in the acute phase (<6 weeks) of injury and on 64 (16.9%) knees more than 6 weeks after injury for a total of 364 athletes (378 knees). Cooper's classification was used to classify the meniscal tears according to the type and location.

Results

Overall, 262 of 378 tears (69.3%) were located in the medial meniscus and 116 (30.7%) in the lateral meniscus. Vertical tears (77.5%) were significantly more frequent than were horizontal tears (22.5%; ϰ2 test, P < .001). A total of 23.2% of tears involved the peripheral zones (zone 0 or 1), and tears that extended into the posterior horn accounted for 75.7%. Regarding the tear shape between male and female athletes, on both sides there were no statistically significant differences in the percentage of horizontal, bucket-handle, longitudinal, or radial tears.

Conclusion

The characteristics of isolated meniscal tears differ with regard to the sport, sex, and tear location and type from those seen in unstable knees. This knowledge is useful in knee injury management.
Biomechanical and Anatomical Effects of an External Rotational Torque Applied to the Knee
Authors: Csintalan Rick P. , Ehsan Amirhesam , McGarry Michelle H. , Fithian Donald F. , Lee Thay Q.
Published: May 2006

Background

External rotational torque is one of the mechanisms that may occur during a pivoting or twisting injury to the knee.

Hypothesis

Simulated external rotational injury by applying external rotational torque will increase knee laxity and cause soft tissue damage to the knee.

Study Design

Controlled laboratory study.

Methods

Six cadaveric knees and a custom testing system were used to produce external rotational torque of 30°, 45°, and 60° with the knee at 30° of flexion. Anterior-posterior, valgus-varus, and rotational knee laxity were quantified. After sequential rotational torque to 60°, the specimens were dissected to identify injured structures.

Results

External rotational torque of 45° and 60° significantly increased knee joint laxity in all directions (P <. 05). Dissection showed that all posterior cruciate ligaments were intact; all medial collateral and anterior cruciate ligaments revealed either partial or complete tears. The lateral collateral ligaments were torn in all specimens. The popliteus tendon was attenuated in 1 specimen and was completely torn in 1 specimen. The popliteofibular ligament was torn in 3 specimens.

Conclusion

External rotational torque to 60° increased knee laxity, and dissection revealed a consistent pattern of injury to the medial and lateral collateral and anterior cruciate ligaments and posterolateral corner.

Clinical Relevance

Because isolated ligament injuries are rare, recognizing these combined ligamentous injuries early is essential for repair in the acute stage.
Revision Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft
Authors: Salmon Lucy J. , Pinczewski Leo A. , Russell Vivianne J. , Refshauge Kathryn
Published: May 2006

Background

The results of revision anterior cruciate ligament reconstruction are limited in the current literature, and no studies have previously documented the outcome of revision anterior cruciate ligament reconstruction using solely hamstring tendon grafts.

Hypothesis

Revision anterior cruciate ligament reconstruction with 4-strand hamstring tendon graft affords acceptable results and is comparable to reported outcomes with the bone–patellar tendon–bone graft.

Study Design

Case series; Level of evidence, 4.

Methods

Fifty-seven consecutive revision anterior cruciate ligament reconstructions with the hamstring tendon graft and interference screw fixation were assessed a mean time of 89 months (range, 60-109 months) after surgery. Assessment included the International Knee Documentation Committee knee ligament evaluation, instrumented laxity testing, and radiologic examination.

Results

Of the 50 knees reviewed, 5 (10%) had objective failure of the revision anterior cruciate ligament reconstruction. Of the 45 patients with functional grafts, knee function was normal or nearly normal in 33 patients (73%). An overall grade of normal or nearly normal was found in 56% of patients. The mean side-to-side difference on manual maximum testing was 2.5 mm (range,–1 to 4 mm). Degenerative changes on radiographs were identified in 23% of patients at the time of surgery, increasing to 56% of patients at review. The status of the articular cartilage at the time of revision surgery was the most significant contributor to successful outcome.

Conclusion

Revision anterior cruciate ligament reconstruction with hamstring tendon graft and interference screw fixation affords acceptable results at a minimum of 5 years’ follow-up. Good objective results can be obtained, but subjectively, the results appear inferior to those of primary anterior cruciate ligament reconstruction in the literature, which may be related to the high incidence of articular surface damage in this patient population. We recommend that, when available, hamstring tendon autografts should be considered for revision anterior cruciate ligament reconstruction.
Lateral Epicondylitis
Authors: Cummins Craig A.
Published: May 2006

Background

Surgical management of lateral epicondylitis has traditionally consisted of an open incision with debridement of the affected extensor tendon tissue. More recently, arthroscopy has been reported as a surgical option for this condition.

Purpose

To evaluate the effectiveness of arthroscopic debridement in excising the characteristic tendinopathy of chronic lateral epicondylitis and determine if residual tendinopathy correlated with poorer patient outcomes.

Study Design

Case series; Level of evidence, 4.

Methods

Data were prospectively collected on all patients who underwent arthroscopic debridement of chronic lateral epicondylitis during a 2-year period. The arthroscopic debridement was assessed in regard to its effectiveness in excising the characteristic tendinopathy through a traditional open procedure by gross and histologic analysis. Outcomes data were collected on all patients preoperatively and at a minimum of 1 year postoperatively. Patient outcomes were then correlated with the residual histologic tendinopathy after arthroscopic debridement.

Results

Eighteen patients were enrolled in the investigation. Gross evidence of residual tendinopathy was identified in 6 patients, with all 6 cases occurring during the first year of the study. Of the 18 patients, 10 had residual histologic evidence of tendinopathy after arthroscopic debridement. Poorer outcomes were identified in those patients who had residual histologic tendinopathy on their rating of worst level of pain (P = .03).

Conclusion

Residual microscopic tendinopathy is often present after arthroscopic debridement. Clinically, residual microscopic tendinopathy correlated with poorer surgical outcomes in regard to patient's rating of their worst level of pain.
Risk Factors for Injury in Indoor Compared with Outdoor Adolescent Soccer
Authors: Emery Carolyn A. , Meeuwisse Willem H.
Published: May 2006

Background

There are limited data on the epidemiology of indoor soccer injuries.

Purpose

Injury rates and risk factors for injury in adolescent indoor and outdoor soccer in the same cohort of players will be identified and compared.

Study Design

Cohort study (prevalence); Level of evidence, 2.

Methods

The study population was a random sample of 21 adolescent (ages 13-17 years) outdoor soccer teams (N = 317). The subcohort included players continuing to play in the indoor soccer season (n = 142). The injury definition included any injury occurring in soccer that resulted in medical attention, the inability to complete a session, and/or missing a subsequent session.

Results

The overall injury rate found in indoor soccer over 20 weeks was 4.45 injuries per 1000 player hours (95% confidence interval, 3.1–6.19). The overall injury rate found in the 13-week outdoor soccer season among a similar cohort was 5.59 injuries per 1000 player hours (95% confidence interval, 4.42–6.97). The relative risk of injury suggests that there was no significant difference between injury rates by age group or gender in indoor soccer compared with outdoor soccer. The risk of injury in the most elite division of play was greater in outdoor compared with indoor soccer (relative risk, 3.22; 95% confidence interval, 1.8-6.12). The most commonly injured body part in both indoor and outdoor soccer was the ankle, followed by the groin in indoor and the knee in outdoor soccer.

Conclusion

There were no significant differences in overall injury rates found by gender or age group for indoor compared with outdoor soccer. Future research should focus on injury prevention strategies to reduce lower extremity injury in indoor and outdoor adolescent soccer.
Convergent and Discriminant Validity of the Internalizing Symptoms Scale for Children
Authors: Crowley Susan L. , Merrell Kenneth W.
Published: May 2006

The Internalizing Symptoms Scale for Children (ISSC) is a relatively new self-report measure designed to assess the broad domain of internalizing problems of children and to integrate the two- and three-factor models of affect proposed by Watson, Clark, and colleagues (cf. Watson & Clark, 1992). To date, limited research has been conducted investigating the performance of the negative affect/general distress and positive affect dimensions of the ISSC. The present research investigated convergent and discriminant validity coefficients between domain-specific self-report (RCDS, RCMAS, SSRS) and peer-report (PNID) measures with both the ISSC total and subscale scores. Validity coefficients support the continued use of the ISSC total score as a measure of distress that compares favorably with other commonly used measures. Correlations between ISSC subscales and other self-report measures indicate that the relationships between positive affect and negative affect and anxiety and depression proposed in the adult literature may also apply to children. Implications for clinical practice and future research are discussed.
Possible Criterion-Related Bias of the WISC-III with a Referral Sample
Authors: Glutting Joseph J. , Oh Hyeon-Joo , Ward Thomas , Ward Sandra
Published: May 2006

This study examined whether ability scores from the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) showed criterion-related bias. Participants (N= 832) comprised a referral cohort between ages 8 and 16 years that differed by race (Anglo, African American) and gender. Verbal, Performance, and Full Scale IQs from the WISC-III were used to predict Reading, Mathematics, Language, and Writing Composites from the Wechsler Individual Achievement Test (WIAT). Unlike previous research with the WISCIII, 50% of the analyses (12 out of 24) showed statistically significant effects. However, in all instances where bias was found, differences in regressions were statistically significant for intercepts, but not for slopes, and served to overpredict the performance of minority groups (African Americans, females) relative to majority groups (Anglos, males). Results are discussed in the context of how instances of differences in intercepts could mislead psychologists in interpreting children's ability scores.
Multidimensional Life Satisfaction Reports of Middle School Students with Serious Emotional Disturbance
Authors: Griffin Michael D. , Huebner E. Scott
Published: May 2006

This study evaluated the potential utility of the Multidimensional Students' Life Satisfaction Scale (MSLSS; Huebner, 1994) with a sample of 49 students in Grades 6 through 8 identified as seriously emotionally disturbed (SED) and a comparison sample of 49 matched non-SED students. The initial internal consistency reliabilities for the MSLSS domains suggested the need to modify the scale for use with middle school SED students. Following scale modifications, reliability estimates for SED students reached acceptable levels for research purposes on five of the six domains. The results also yielded promising, but tentative, support for the validity of the MSLSS when used with SED students. Subsequent comparisons of the mean ratings on the life satisfaction domains revealed that SED students reported lower levels of satisfaction with peer friendships than did their non-SED counterparts. Also, relationships between domain-specific and global life satisfaction judgments differed for the SED students, suggesting that SED students formulate their overall life satisfaction judgments differently than their non-SED peers. Limitations of the current study and implications for future research are discussed.
The Relationship between Two Methods of Evaluating an Examinee's Difference Scores
Authors: Charter Richard A. , Feldt Leonard S.
Published: May 2006

The “nonoverlapping intervals” and “reliable difference” approaches for assessing difference scores are compared and shown to be consistent alternatives when the proper z is used to construct confidence intervals. Formulas for computing the probabilities of correct interpretation (power), overinterpretation, misinterpretation, and underinterpretation for four popular confidence interval approaches and the reliable difference approach are presented. The probability formulas show that the intuitive inference concerning the statistical significance level of nonoverlapping intervals is incorrect. The limitations of the nonoverlapping intervals approach in applied situations are discussed. It appears that in most situations the reliable difference is the easiest to apply.
The Relationship between General Ability Using the Naglieri Nonverbal Ability Test (NNAT) and Stanford Achievement Test (SAT) Reading Achievement
Authors: Naglieri Jack A. , Ronning Margaret E.
Published: May 2006

The relationship between ability measured nonverbally and reading achievement was assessed to determine whether there were developmental differences in the correlations between the variables and to determine the size of the coefficient. It was previously suggested that the relationship between reading and intelligence is not a strong one and that the correlations change considerably across the K through 12th-grade interval. The present study involved approximately 22,000 children who were administered a nonverbal measure of ability called the Naglieri Nonverbal Ability Test (NNAT) and measures of reading included in the Stanford Achievement Test Ninth Edition (SAT-9). Results demonstrated that the NNAT was strongly correlated with the SAT-9 and that the overall correlation with Total Reading was large (.56). The hypothesis that ability and reading correlations change considerably across grades K-12 was not supported, but the view that intelligence as measured by a nonverbal test and reading are strongly related was supported.
A Comparison of the Leiter-R and the Universal Nonverbal Intelligence Test (UNIT) with Children Classified as Language Impaired
Authors: Farrell Megan M. , Phelps LeAdelle
Published: May 2006

The Leiter-R and the Universal Nonverbal Intelligence Test (UNIT) were administered in counterbalanced order to 43 children (12 females, 31 males) who were classified as severely language disordered (mean age = 8.55, SD = 1.78). All standard scores were depressed and ranged from 65.07 (Leiter Fluid Reasoning Composite) to 70.00 (UNIT Symbolic Memory), suggesting global cognitive deficits that extend beyond language. Correlations and t-test analyses compared similar scores. The correlations were significant (i.e., Leiter-R Visualization and Reasoning Battery Full Scale IQ/UNIT Full Scale IQ= .80, Leiter-R Fluid Reasoning Subscale/UNIT Reasoning Subscale = .66); t-test computations were nonsignificant. Given the critical language deficiencies of this population, it was concluded that either battery provided a nonbiased assessment of cognitive abilities. Qualitative strengths and weaknesses of both tests were discussed.
A Convergent Validity Study of the Differential Ability Scales and the Wechsler Intelligence Scale for Children-Third Edition with Hispanic Children
Authors: DiCerbo Kristen Eignor , Barona Andrés
Published: May 2006

Intellectual assessment of minority children continues to occupy a position of importance in the practice of school psychology. A review of the extant literature suggests a continuing controversy regarding the adequacy of current intelligence tests to measure the cognitive ability of U.S. minority children. The present study examined the relationship between the DAS, an individually administered cognitive and achievement test developed for use with children and adolescents, and the WISC-III, the most commonly used intelligence test for children. Both the DAS and the WISC-III were administered to a sample of 24 English-speaking Hispanic children between the ages of 9 and 11. Global and factor scores for both tests were compared, with special attention paid to verbal/performance score discrepancies. A relationship between the WISC-III and the DAS was indicated, providing evidence for the convergent validity of the DAS and the WISC-III in assessing English-speaking Hispanic children residing in the United States. Results of the study are further discussed in terms of the use of the DAS in the evaluation of Hispanic students.
Convergent, Discriminant, and Predictive Validity of the Teacher Rating of Academic Achievement Motivation (TRAAM) with The ACTeRS-TF and the BASC-TRS
Authors: Oehler-Stinnett Judy , Boykin Cynthia
Published: May 2006

Motivation is a critical component of school functioning to be considered in functional behavior assessments. The Teacher Rating of Academic Achievement Motivation (TRAAM), developed to facilitate appraisal of this important construct, was correlated with the BASC and the ACTeRS-TF to provide school psychologists with information essential to differential diagnosis within a multifactored evaluation. The TRAAM was positively correlated with positive components of the BASC and ACTeRS-TF such as Attention and Adaptive skills and negatively correlated with maladaptive behaviors such as School Problems. These results, along with the TRAAM subscale intercorrelations, support a general pattern of convergent and discriminate validity for the TRAAM and use of mastery and amotivation interpretations of behavior. The TRAAM Skill/Ability factor was also a significant predictor of IOWA Test of Basic Skills Reading and Math scores, indicating support for the skill versus performance aspects of interpretation as well. Overall, results suggest that motivation, as measured by the TRAAM, may be used in the interpretation of traditional behavior problems such as attention and oppositional behavior, as well as for targeting positive skills for intervention purposes.