bluuebunny/crossref_metadata_2025 huggingface dataset:
Pooling, Access, and Countervailing Power in Channel Governance
Authors: Hendrikse George
Published: July 2011

Fruit and vegetable marketing organization the Greenery has experienced various governance structure changes, like horizontal merger, forward integration, and the emergence of grower associations. A multilateral incomplete contracting model is presented to account for these changes by analysing the interactions between pooling, access, and countervailing power. This model does not only explain the changes at the Greenery, but it contributes also to the design of efficient channel governance.

This paper was accepted by Pradeep Chintagunta and Preyas Desai, special issue editors.

This paper was accepted by Pradeep Chintagunta and Preyas Desai, special issue editors.
Deriving the Pricing Power of Product Features by Mining Consumer Reviews
Authors: Archak Nikolay , Ghose Anindya , Ipeirotis Panagiotis G.
Published: July 2011

Increasingly, user-generated product reviews serve as a valuable source of information for customers making product choices online. The existing literature typically incorporates the impact of product reviews on sales based on numeric variables representing the valence and volume of reviews. In this paper, we posit that the information embedded in product reviews cannot be captured by a single scalar value. Rather, we argue that product reviews are multifaceted, and hence the textual content of product reviews is an important determinant of consumers' choices, over and above the valence and volume of reviews. To demonstrate this, we use text mining to incorporate review text in a consumer choice model by decomposing textual reviews into segments describing different product features. We estimate our model based on a unique data set from Amazon containing sales data and consumer review data for two different groups of products (digital cameras and camcorders) over a 15-month period. We alleviate the problems of data sparsity and of omitted variables by providing two experimental techniques: clustering rare textual opinions based on pointwise mutual information and using externally imposed review semantics. This paper demonstrates how textual data can be used to learn consumers' relative preferences for different product features and also how text can be used for predictive modeling of future changes in sales.

This paper was accepted by Ramayya Krishnan, information systems.
Connecting Employers With People Who Have Intellectual Disability
Authors: Luecking Richard G.
Published: July 2011

Longstanding advocacy for employment opportunity, recent legislative and policy developments, and advancements in employment service practice have contributed to an emerging notion of presumptive employability for individuals with disabilities. Unfortunately, low levels of employment remain the norm for people with disabilities, especially those with intellectual disability. Further, an examination of employer views of people with intellectual disability suggests that effective connections remain elusive between employers and employment service programs that support job seekers with intellectual disability. In this article employer perspectives are considered and case descriptions of effective connections of people with intellectual disability to employers are provided in order to meet demand-side operational needs. These perspectives have implications for elevating the effectiveness of employment service practice.
Jobs by 21 Partnership Project: Impact of Cross-System Collaboration on Employment Outcomes of Young Adults With Developmental Disabilities
Authors: Winsor Jean E. , Butterworth John , Boone Jane
Published: July 2011

In 2007, the low level of young adults with developmental disabilities who were employed in the 3 months postgraduation from high school led the Washington State legislature to authorize and fund the Jobs by 21 Partnership Project. The intent of the project was to identify and demonstrate best practices in sustainable partnerships among Washington State's school and adult service systems. Results indicated that participants in the project were more likely to be employed following school exit and had stronger employment outcomes than students who did not participate. Further, data suggest that improved employment outcomes were supported by the leveraging and maximization of financial and in-kind resources and the strengthening of collaborative relationships across project stakeholders.
Historical Perspectives
Authors: Toubas Paul-Louis
Published: July 2011

Twenty vibrant years, starting in 1960, marked the beginning of modern neonatology, and during those years, the participation of women in medical science increased amid a flurry of national and international social and historical events. The availability of grants allowed the exploration of the newborn infant's biology. Young women pediatricians and scientists studied brain development, and newborn intensive care started to proliferate. The virtues of early feeding were recognized. Infections were actively prevented and treated. Assisted ventilation provided life support to infants whose lungs could not remain inflated due to surface tension deficiency. Noninvasive measurement of Pao2 signaled a kinder approach to oxygenation monitoring and newborn care. Advances were made in the understanding of jaundice and the prevention of kernicterus. Sudden infant death syndrome came under question, leading to studies on the control of respiration. Many of these outstanding women were rewarded, but leadership academic positions frequently remained out of the reach of other deserving women. By the beginning of 1980, the number of women in neonatal-perinatal medicine began to climb exponentially.
Produtividade de grãos de milho e massa seca de braquiárias em consórcio no sistema de integração lavoura-pecuária
Authors: Pariz Cristiano Magalhães , Andreotti Marcelo , Azenha Mariana Vieira , Bergamaschine Antonio Fernando , Mello Luiz Malcolm Mano de , Lima Ronaldo Cintra
Published: July 2011

Objetivou-se avaliar as produtividades de grãos de milho e massa seca de braquiárias em duas modalidades de consórcio em sistema de integração lavoura-pecuária no período de inverno-primavera em região do Cerrado. O experimento foi conduzido no ano de 2006, na Fazenda de Ensino, Pesquisa e Extensão (FEPE), pertencente à Faculdade de Engenharia (FE/UNESP - Campus de Ilha Solteira), localizada no município de Selvíria, MS. O delineamento experimental utilizado foi de blocos casualizados, em esquema fatorial 4x2, com cinco repetições. Os tratamentos constituíram-se de quatro espécies de braquiárias (Brachiaria brizantha cv. 'Marandu', Brachiaria decumbens, Brachiaria ruziziensis e Brachiaria híbrido cv. 'Mulato II') consorciadas na linha e a lanço no momento da semeadura do milho. Avaliaram-se os componentes da produção, a produtividade do milho, bem como a massa seca das braquiárias após a colheita do milho. As forrageiras consorciadas a lanço, com destaque para a Brachiaria ruziziensis proporcionaram menor desenvolvimento das plantas de milho e menores valores dos componentes da produção, bem como da produtividade de grãos. Apesar de satisfatórias produtividades de massa seca (acima de 2.500kg ha-1), com exceção da Brachiaria brizantha, as demais espécies consorciadas a lanço foram superiores, com destaque para a Brachiaria decumbens e a Brachiaria ruziziensis que apresentaram maior adaptabilidade e produtividade de forragem no consórcio com milho em sistema de integração lavoura-pecuária.
Seleção de parâmetros através do método Taguchi para soldagem de revestimento com ligas de níquel pelo processo MIG/MAG
Authors: Pessoa Antonio Rodolfo Paulino , Miranda Hélio Cordeiro de , Farias Jesualdo Pereira , Aguiar Willys Machado , Assis Filho Francisco de
Published: July 2011

Neste trabalho utilizou-se o método Taguchi (planejamento Robusto de experimentos), para cumprir com um reduzido número de ensaios, dois objetivos: obter a influência dos fatores de controle sobre as variáveis respostas e determinar as condições ideais para aplicação das ligas de níquel nas soldagens de revestimentos através do processo MIG/MAG com transferência metálica por curto-circuito. Foram escolhidos seis fatores de controle com três níveis cada: Tensão de referência, Velocidade de soldagem, Tipo de tecimento, Técnica da tocha, Gás de proteção e o Material de adição. Por sua vez as variáveis respostas escolhidas foram: Diluição (D) e Razão entre o reforço e a largura (R/L). As soldagens foram realizadas na posição plana por simples deposição sobre chapas de aço ASTM 516 Gr60 com dimensões de 200 x 50 x 12,7 mm. O uso do tecimento proporcionou cordões com baixos valores da razão R/L e obteve valores bastante baixos de diluição chegando à ordem de 5%. A combinação dos níveis dos fatores de controle apontados como ótimos pelo método Taguchi resultaram em valores para as variáveis repostas consideradas adequadas para a soldagem de revestimento.
Spatial variance in abundance and occupancy of corals across broad geographic scales
Authors: Karlson Ronald H. , Connolly Sean R. , Hughes Terence P.
Published: July 2011

Species assemblages vary in structure due to a wide variety of processes operating at ecological and much broader biogeographical scales. Cross‐scale studies of assemblage structure are necessary to fully understand this variability. Here, we evaluate the abundance and occupancy patterns of hierarchically sampled coral assemblages in three habitats (reef flat, crest, and slope) and five regions (Indonesia, Papua New Guinea, the Solomon Islands, American Samoa, and the Society Islands) across the west‐central Pacific Ocean. Specifically, we compare two alternative models that unify spatial variance and occupancy via the negative binomial distribution. The first assumes a power‐law scaling between the mean and variance of abundance; the second assumes a quadratic variance–mean relationship and a constant abundance‐invariant aggregation parameter. Surprisingly, the well‐established power‐law model performs worse than the model assuming abundance‐invariant aggregation, for both variance–mean and occupancy–abundance relationships. We also find strong evidence for regional and habitat variation in these relationships and in the levels of aggregation estimated by the abundance‐invariant aggregation model. Among habitats, corals on reef flats exhibited lower occupancy and higher levels of aggregation compared to reef crests and slopes. Among regions, low occupancy and high aggregation were most pronounced across all habitats in American Samoa. These patterns may be related to habitat and regional differences in disturbance and recovery processes. Our results suggest that the spatial scaling of abundance and occupancy is sensitive to processes operating among these habitats and at regional scales. However, the consistency of these relationships across species within assemblages suggests that a theoretical unification of spatial variance and occupancy patterns is indeed possible.
Multivariate identification of plant functional response and effect traits in an agricultural landscape
Authors: Pakeman Robin J.
Published: July 2011

Plant functional traits have been proposed as a linkage between the environmental control of vegetation and ecosystem function. Identification of traits that mediate the response of plant species to the environment is well established, but the identification of effect traits and the linkage between the two sets is less developed. This was attempted for a study of eight contrasting land uses in a marginal agricultural landscape where data on vegetation, management controls of the disturbance regime, and soil characteristics, including nitrogen release, were measured simultaneously with measures of ecosystem function such as litter decomposition rates and primary productivity on 30 sites. Trait data were assembled from databases, and an iterative multivariate approach using the three table (species, trait, environment) method RLQ was employed to identify a parsimonious set of traits that predict plant species responses to the environment and a parsimonious set of traits that link vegetation to ecosystem function. The lists of response and effect traits were similar, and where differences were observed, traits were usually highly correlated with at least one trait in the other list. This approach identified a small number of traits (canopy height, leaf dry matter content, leaf size, and specific leaf area) that provide a means of linking vegetation responses to environmental change with changes in ecosystem function. Other response traits included vegetative spread strategy, start of flowering, and seed terminal velocity, but within the system studied these traits were all significantly correlated to the traits shared between the response and effect lists.
Tree demography in an undisturbed Dipterocarp permanent sample plot at Uppangala, Western Ghats of India
Authors: Pélissier Raphaël , Pascal Jean-Pierre , Ayyappan N. , Ramesh B. R. , Aravajy S. , Ramalingam S. R.
Published: July 2011

We provide a data set on demography of trees monitored over 20 years in Uppangala permanent sample plot (UPSP) in undisturbed, old‐growth wet evergreen Dipterocarp forest located within the Pushpagiri Wildlife Sanctuary in India's Western Ghats biodiversity hotspot. During 1989–1990, all trees ≥30 cm girth at breast height (gbh) were sampled in five north–south transects 20 m wide and 180 to 370 m long covering a total area of 3.12 ha. In 1992–1993, additional rectangular plots were established, bringing the total area sampled to 5.07 ha. In all, 3870 trees were identified, tagged, mapped, and provided with permanent dendrometer bands. Since then, the sampled area has been regularly censused at 3–5 year intervals, recording tree recruitment, mortality, and growth. We present data from censuses conducted in 1990–1993, 1994, 1997–1998, 2001–2002, 2007, and 2010. These data have been used to study the natural forest dynamics and to calibrate spatially explicit simulation models.
Migration of a synclinal depocentre from turbidite growth strata: the Annot syncline, SE France
Authors: Salles Lise , Ford Mary , Joseph Philippe , Le Carlier De Veslud Christian , Le Solleuz Antoine
Published: July 2011

The Annot Sandstone turbidites of the Alpine foreland basin in SE France (Eocene-Oligocene: 40-32 Ma), provide an excellent case-study of tectono-sedimentary relations in a deepwater compressional system. The Annot outlier is a synclinal remnant previously interpreted as a static depocentre. A multi-disciplinary approach including geometrical and kinematic analyses and modelling demonstrates instead that this was a tectonically active turbidite depocentre where gentle thrust related folding controlled turbidite architecture.

Stratigraphic and new structural field data are integrated with previous sedimentological studies to build a 3D geometric model of the Annot depocentre. Derived thickness maps associated with paleocurrent measurements clearly illustrate three main phases in the evolution of depocentre topography. (1) Early turbidite flows were mainly trapped by oblique intrabasinal inherited structures. (2) Once these structures were buried, the NNW-SSE active syncline constituted the main topographic control. (3) Decreasing activity of this syncline is recorded by filling and flow bypass. The progressive stages of the accepted depositional model (flow ponding, flow stripping and flow bypass), for the Annot depocentre, may therefore have a tectonic origin.

The kinematic evolution of the synclinal depocentre was defined at different scales. Stratigraphic architecture records a decrease in bedding dips up through the turbidite succession on the western synclinal limb. Comparison with idealized case studies of the interaction of sedimentation with an active syncline indicates that this geometrical pattern corresponds to progressive westward migration of the synclinal hinge and depocentre. This tends to promote lateral rather than vertical stacking of sand bodies during turbidite sedimentation. Trishear kinematic modelling was used to simulate (in 2D) the rolling synclinal hinge. Stratigraphic surface geometries and turbidite depocentre migration define thrust and fold geometries at depth. The synclinal depocentre developed between two alternating or coeval fault propagation anticlines that exploited two detachment levels (Triassic evaporites and Cenomanian marls) in the underlying succession.
Upper Toarcian-Lower Bajocian (Jurassic) Hammatoceratoidea (Ammonitina) of the Betic Cordillera (southern Spain): biostratigraphy and zonal correlations
Authors: Sandoval José , Martínez Gemma , Ureta Soledad
Published: July 2011

Betic hammatoceratoids from several sections of the Subbetic domain (Middle and External Subbetic) are here analysed from a biostratigraphic standpoint. Fifty-five hammatoceratoids “species” belonging to 17 genera occur throughout the Upper Toarcian-lowermost Bajocian interval. The best fossiliferous sections containing hammatoceratoids are located in the central and eastern sector of the Median Subbetic. In these areas grey marls and marly-limestone rhythmites are the predominant lithofacies from the Upper Toarcian to Lower Bajocian interval. Hammatoceratidae are the dominant hammatoceratoids during the Upper Toarcian, the Erycitidae are more common in the Lower Aalenian, and Zurcheriinae are especially abundant in the uppermost Aalenian-lowermost Bajocian.

Six ammonite biozones, which can be easily correlated with the standard ammonite zones, have been defined based on the stratigraphic ranges of these species. These biozones are : a) Geczyceras meneghinii Biozone, which is equivalent to the Meneghinii Zone (Levesquei Subzone p.p. and Pseudoradiosa Subzone) and Aalensis Zone (Mactra Subzone p.p.); b) Erycites barodiscus Biozone, which ranges throughout the Aalensis Zone (Mactra p.p., Aalensis and Buckmani Subzones) and the Opalinum Zone (Opalinum Subzone); c) Erycites fallifax Biozone, which can be correlated with the Comptum Subzone of the Opalinum Zone; d) Spinammatoceras tenax Biozone, which coincides with Murchisonae Zone-Bradfordensis Zone (Bradfordensis Subzone); e) Malladaites pertinax Biozone, which coincides roughly with Bradfordensis Zone (Gigantea Subzone)-Concavum Zone (lower part of the Concavum Subzone); f) Haplopleuroceras mundum Biozone, extending to the upper part of the Concavum Subzone to the lowermost Bajocian (Discites, p. p., Zone). Although some of the recorded hammatoceratoids are typical of the western Tethys, others (especially the genera Eudmetoceras and Euaptetoceras) are globally widespread. Consequently, the use of these taxa enables stratigraphic correlations, not only with the western Tethys, but also with other palaeogeographic areas such as the central Tethys, eastern Pacific and even the eastern Tethys.
A systematic approach to determine herbicide removals in constructed wetlands using time integrated passive samplers
Authors: Page Declan W. , Khan Stuart J. , Miotlinski Konrad
Published: July 2011

Natural water treatment systems such as wetlands are increasingly being recognised for their role as part of a multi-barrier system for water recycling. Natural wetland systems have the ability to provide effective treatment for a wide range of organic chemicals. However, techniques are required to validate the performance of these treatment processes in the field. This paper provides a new method for evaluating wetland systems using passive samplers and applies a statistical method for use in advanced water treatment processes. Three years of stormwater quality passive sampler data for diuron, simazine and atrazine is provided to determine herbicide removal between the inlet and outlet regions of a constructed wetland. Mean removal rates over the three year period for diuron, simazine and atrazine were 43, 54 and 50% respectively. The results show that this method coupled with passive samplers is amenable to wetland system barrier characterisation where opportunities for process validation is not feasible.
Effect of Fermentation on Chemical Composition and Nutritional Quality of Extruded and Fermented Soya Products
Authors: Ojokoh Anthony O , Yimin Wei
Published: July 2011

The effect of fermentation on chemical composition, amino acid profile and protein digestibility of extruded soya protein products was investigated. The soya protein products (low moisture extruded soya product, medium moisture extruded soya product, high moisture extruded soya product, soya meal and soya kernel) were fermented with Bacillus natto from small and large brands of soya bean cultivar. The protein content (%) ranged from 38.20 to 62.98 with the highest content in the high moisture extruded protein product fermented with Bacillus natto from large brand of soya bean cultivar. Contents of carbohydrates ranged from 14.77 to 29.08 while those of crude fibre, fat and ash were generally low. Fermentation improved protein digestibility in the raw soya meal and kernel than in the unfermented extruded and extruded fermented products. Extrusion reduced the nitrogen solubility index of the extruded samples. The contents of amino acids except arginine increased in all the samples after fermentation. Trypsin inhibitor activity decreased from 27.33 TIU/g in the unfermented soya sample to between 1.58 and 18.5 TIU/g after fermentation, whereas there was a decrease in phytic acid content only in the fermented soya meal and low moisture extruded soya sample.
Color Based Classification for Berries of Japanese Blue Honeysuckle
Authors: Fu Longsheng , Okamoto Hiroshi , Kataoka Takashi , Shibata Youichi
Published: July 2011

Japanese blue honeysuckle (Lonicera caerulea L. var. emphyllocalyx Nakai) is a unique form of edible honeysuckle that has exceptionally tasty berries. Visual characteristics of the berry such as the color of the skin and the presence of defects are the most decisive factors in determining its quality. An image analysis based methodology for classifying the berries under uncontrolled outside lighting conditions was developed. A color sheet with hue value around 29° was determined as the background to support the berries whose hue values were found near 212°. With the thresholding level computed by Otsus algorithm in the red channel, berries were segmented from the background successfully. Three parameters, average and standard deviation of hue component and average of saturation component, were chosen as the best descriptions for each berry according to the Fishers least significant differences test. Three canonical functions and corresponding group centroids of each function obtained by discriminant analysis were able to classify the berries aimed for fresh market, processing, and waste at success rates of 95.1%, 85.1%, and 94.3%, respectively.
Concept extraction and clustering for search result organization and virtual community construction
Authors: Chen Shihn-Yuarn , Chang Chia-Ning , Nien Yi-Hsiang , Ke Hao-Ren
Published: July 2011

This study proposes a concept extraction and clustering method, which
improves Topic Keyword Clustering by using Log Likelihood Ratio for semantic
correlation and Bisection K-Means for document clustering. Two value-added
services are proposed to show how this approach can benefit information
retrieval (IR) systems. The first service focuses on the organization and
visual presentation of search results by clustering and bibliographic
coupling. The second one aims at constructing virtual research communities
and recommending significant papers to researchers. In addition to the two
services, this study conducts quantitative and qualitative evaluations to
show the feasibility of the proposed method; moreover, comparison with the
previous approach is also performed. The experimental results show that the
accuracy of the proposed method for search result organization reaches 80%,
outperforming Topic Keyword Clustering. Both the precision and recall of
virtual community construction are higher than 70%, and the accuracy of paper
recommendation is almost 90%.
Evaluation and comparison of outcomes in dogs with periarticular and nonperiarticular histiocytic sarcoma
Authors: Klahn Shawna L. , Kitchell Barbara E. , Dervisis Nikolaos G.
Published: July 2011

Objective—To evaluate and compare the outcomes of dogs with periarticular histiocytic sarcoma (PAHS) and histiocytic sarcoma of other anatomic locations (non-PAHS) and identify factors associated with outcome for dogs with PAHS.

Design—Retrospective cohort study.

Animals—19 dogs with PAHS and 31 dogs with non-PAHS.

Procedures—Medical records of dogs with histiocytic sarcoma that underwent definitive local treatment (surgery or radiation), chemotherapy, or a combination of these were reviewed. Patient signalment, clinical signs, staging test results, clinicopathologic data, type of treatment, response, and outcome were collected, and potential risk factors in dogs with PAHS were identified and analyzed for an association with outcome.

Results—Dogs with PAHS lived significantly longer than did dogs with non-PAHS, with an overall median survival times of 391 (range, 48 to 980) and 128 (range, 14 to 918) days, respectively, despite the presence of suspected metastasis at diagnosis in 13 of 19 dogs with PAHS. Dogs with PAHS without evidence of metastasis at diagnosis lived significantly longer than did dogs with PAHS with evidence of metastasis, with median survival times of 980 (range, 83 to 980) and 253 (range, 48 to 441) days, respectively. Administration of prednisone in dogs with PAHS was associated with a significantly shorter time to tumor progression (TTP) and increased risk of tumor progression and death.

Conclusions and Clinical Relevance—Results indicated that dogs with PAHS may have a favorable outcome independent of metastatic status when treated with chemotherapy or aggressive multimodal treatment. The concurrent administration of prednisone may be a negative predictive factor for survival time and TTP in dogs with PAHS.
Splitting dynamics of a two-species Bose-Einstein condensate in two translating traps
Authors: Sun Bo , Pindzola Michael
Published: July 2011

We extend our previous work of splitting a single-species Bose-Einstein condensate in two translating traps to a two-species condensate. Different from the single species case where interaction is considered as a damping mechanism to the motion of the condensate, we find that, in the two species case, the damping effect is much less obvious and the splitting dynamics exhibit different behaviors. The distribution of each component are not damped towards 50:50 for large interaction strength in the two wells. Our conclusions are supported by investigating the dependence of the splitting on both the translation speed and the interspecies scattering length.
Superficial mycoses in the Nis region, Southeast-Serbia
Authors: Otasevic Suzana , Đorđević Jovana , Ranđelović Gordana , Ignjatović Aleksandra , Stojanović Predrag , Zdravković Dragan , Marković Roberta
Published: July 2011

The aim of the study is to investigate the most frequent cause of superficial mycoses in patients from the territory of city Niš Southeast Serbia in the period from 1998 to 2010. A total of 3223 samples from 2887 patients with suspected dermatomycoses were examined. Superficial mycoses were diagnosed using standard microbiology techniques (conventional microscopy and cultivation). Dermatophytes were determined on the basis of their macroscopic and microscopic morphological and morphometric characteristics. Morphometric characteristics were obtained by Laboratory Universal Computer Image Analysis system (Lucia M, 1996). Species of genus Candida were identified using the test of production of germ tube in sera, by growth on comertial chromatogen medium (Chromotogenic Candida, Liofichem/Bacteriology products, Italy) and by using Auxacolor TMBioRad, France. The results were elaborated with the statistical method of descriptive and quantitative analysis (SPSS 14.0 for Windows 2003). The prevalence of superficial mycoses was 25,1%. Dermatophytes were identified in 67.6% of all positive cultures. Microsporum canis was the most prevalent (50.3%) dermatophyte isolated, followed by Trichophyton metagrophytes var. mentagrophytes (35.4%). Yeast genus Candida has become a more frequent cause of superficial fungal infection since 2001. and C. albicans was the dominant yeast (61.1%).
Lumbar Synovial Cyst
Authors: Barbero Marco , Boscherini Duccio
Published: July 2011

The patient was a 50-year-old woman who was referred to a physical therapist for management of chronic low back pain. Intervention by the physical therapist included therapeutic exercises and manual therapy. However, after 3 weeks, the patient was referred to a neurosurgeon due to worsening of symptoms and failure to respond to conservative interventions. Lumbar spine magnetic resonance imaging and myelography revealed a lesion consistent with a synovial cyst at the level of the left L3-4 facet joint. Following surgical excision of the cyst, the patient's symptoms resolved completely. J Orthop Sports Phys Ther 2011;41(7):533. doi:10.2519/jospt.2011.0415
A Guide to Understanding Meta-analysis
Authors: Israel Heidi , Richter Randy R.
Published: July 2011

Synopsis

With the focus on evidence-based practice in healthcare, a well-conducted systematic review that includes a meta-analysis where indicated represents a high level of evidence for treatment effectiveness. The purpose of this commentary is to assist clinicians in understanding meta-analysis as a statistical tool using both published articles and explanations of components of the technique. We describe what meta-analysis is, what heterogeneity is, and how it affects meta-analysis, effect size, the modeling techniques of meta-analysis, and strengths and weaknesses of meta-analysis. Common components like forest plot interpretation, software that may be used, special cases for meta-analysis, such as subgroup analysis, individual patient data, and meta-regression, and a discussion of criticisms, are included. J Orthop Sports Phys Ther 2011;41(7):496–504. doi:10.2519/jospt.2011.3333
Occipitocervicothoracic stabilization in pediatric patients
Authors: Fargen Kyle M. , Anderson Richard C. E. , Harter David H. , Angevine Peter D. , Coon Valerie C. , Brockmeyer Douglas L. , Pincus David W.
Published: July 2011

Object

Although rarely encountered, pediatric patients with severe cervical spine deformities and instability may occasionally require occipitocervicothoracic instrumentation and fusion. This case series reports the experience of 4 pediatric centers in managing this condition. Occipitocervical fixation is the treatment of choice for craniocervical instability that is symptomatic or threatens neurological function. In children, the most common distal fixation level with modern techniques is C-2. Treated patients maintain a significant amount of neck motion due to the flexibility of the subaxial cervical spine. Distal fixation to the thoracic spine has been reported in adult case series. This procedure is to be avoided due to the morbidity of complete loss of head and neck motion. Unfortunately, in rare cases, the pathological condition or highly aberrant anatomy may require occipitocervical constructs to include the thoracic spine.

Methods

The authors identified 13 patients who underwent occipitocervicothoracic fixation. Demographic, radiological, and clinical data were gathered through retrospective review of patient records from 4 institutions.

Results

Patients ranged from 1 to 14 years of age. There were 7 girls and 6 boys. Diagnoses included Klippel-Feil, Larsen, Morquio, and VATER syndromes as well as postlaminectomy kyphosis and severe skeletal dysplasia. Four patients were neurologically intact and 9 had myelopathy. Five children were treated with preoperative traction prior to instrumentation; 5 underwent both anterior and posterior spinal reconstruction. Two patients underwent instrumentation beyond the thoracic spine. Allograft was used anteriorly, and autologous rib grafts were used in the majority for posterior arthrodesis. Follow-up ranged from 0 to 43 months. Computed tomography confirmed fusion in 9 patients; the remaining patients were lost to follow-up or had not undergone repeat imaging at the time of writing. Patients with myelopathy either improved or stabilized. One child had mild postoperative unilateral upper-extremity weakness, and a second child died due to a tracheostomy infection. All patients had severe movement restriction as expected.

Conclusions

Occipitocervicothoracic stabilization may be employed to stabilize and reconstruct complex pediatric spinal deformities. Neurological function can be maintained or improved. The long-term morbidity of loss of cervical motion remains to be elucidated.
Pediatric Chiari malformation Type 0: a 12-year institutional experience
Authors: Chern Joshua J. , Gordon Amber J. , Mortazavi Martin M. , Tubbs R. Shane , Oakes W. Jerry
Published: July 2011

Object

In 1998 the authors identified 5 patients with syringomyelia and no evidence of Chiari malformation Type I (CM-I). Magnetic resonance imaging of the entire neuraxis ruled out other causes of a syrinx. Ultimately, abnormal CSF flow at the foramen magnum was the suspected cause. The label “Chiari 0” was used to categorize these unique cases with no tonsillar ectopia. All of the patients underwent posterior fossa decompression and duraplasty identical to the technique used to treat patients with CM-I. Significant syrinx and symptom resolution occurred in these patients. Herein, the authors report on a follow-up study of patients with CM-0 who were derived from over 400 operative cases of pediatric CM-I decompression.

Methods

The authors present their 12-year experience with this group of patients.

Results

Fifteen patients (3.7%) were identified. At surgery, many were found to have physical barriers to CSF flow near the foramen magnum. In most of them, the syringomyelia was greatly diminished postoperatively.

Conclusions

The authors stress that this subgroup represents a very small cohort among patients with Chiari malformations. They emphasize that careful patient selection is critical when diagnosing CM-0. Without an obvious CM-I, other etiologies of a spinal syrinx must be conclusively ruled out. Only then can one reasonably expect to ameliorate the clinical course of these patients via posterior fossa decompression.
Intradural spinal endoscopy in children
Authors: Chern Joshua J. , Gordon Amber S. , Naftel Robert P. , Tubbs R. Shane , Oakes W. Jerry , Wellons John C.
Published: July 2011

Intracranial endoscopy in the treatment of hydrocephalus, arachnoid cysts, or brain tumors has gained wide acceptance, but the use of endoscopy for intradural navigation in the pediatric spine has received much less attention. The aim of the authors' present study was to analyze their experience in using spinal endoscopy to treat various pathologies of the spinal canal.

The authors performed a retrospective review of intradural spinal endoscopic cases at their institution. They describe 4 representative cases, including an arachnoid cyst, intrinsic spinal cord tumor, holocord syrinx, and split cord malformation.

Intradural spinal endoscopy was useful in treating the aforementioned lesions. It resulted in a more limited laminectomy and myelotomy, and it assisted in identifying a residual spinal cord tumor. It was also useful in the fenestration of a multilevel arachnoid cyst and in confirming communication of fluid spaces in the setting of a complex holocord syrinx. Endoscopy aided in the visualization of the spinal cord to ensure the absence of tethering in the case of a long-length Type II split spinal cord malformation.

Conclusions

Based on their experience, the authors found intradural endoscopy to be a useful surgical adjunct and one that helped to decrease morbidity through reduced laminectomy and myelotomy. With advances in technology, the authors believe that intradural endoscopy will begin to be used by more neurosurgeons for treating diseases of this anatomical region.
A novel method for stereotactic, endoscope-assisted transtentorial placement of a shunt catheter into symptomatic posterior fossa cysts
Authors: Turner Michael S. , Nguyen Ha Son , Payner Troy D. , Cohen-Gadol Aaron A.
Published: July 2011

Object

Posterior fossa cysts are usually divided into Dandy-Walker malformations, arachnoid cysts, and isolated and/or trapped fourth ventricles. Shunt placement is a mainstay treatment for decompression of these fluid collections when their expansion becomes symptomatic. Although several techniques to drain symptomatic posterior fossa cysts have been described, each method carries its own advantages and disadvantages. This article describes an alternative technique.

Methods

In 10 patients, the authors used an alternative technique involving stereotactic and endoscopic methods to place a catheter in symptomatic posterior fossa cysts across the tentorium. Discussion of these cases is included, along with a review of various approaches to shunt placement in this region and recommendations regarding the proposed technique.

Results

No patient suffered intracranial hemorrhage related to the procedure and catheter implantation. All 3 patients who underwent placement of a new transtentorial cystoperitoneal shunt and a new ventriculoperitoneal shunt did not suffer any postoperative complication; a decrease in the size of their posterior fossa cysts was evident on CT scans obtained during the 1st postoperative day. Follow-up CT scans demonstrated either stable findings or further interval decrease in the size of their cysts. In 1 patient, the postoperative head CT demonstrated that the transtentorial catheter terminated posterior to the right parietal occipital region without entering the retrocerebellar cyst. This patient underwent a repeat operation for proximal shunt revision, resulting in an acceptable catheter implantation. The patient in Case 8 suffered from a shunt infection and subsequently underwent hardware removal and aqueductoplasty with stent placement. The patient in Case 9 demonstrated a slight increase in fourth ventricle size and was returned to the operating room. Exploration revealed a kink in the tubing connecting the distal limb of the Y connector to the valve. The Y connector was replaced with a T connector, and 1 week later, CT scans exhibited interval decompression of the ventricles. This patient later presented with cranial wound breakdown and an exposed shunt. His shunt hardware was removed and he was treated with antibiotics. He later underwent reimplantation of a lateral ventricular and transtentorial shunt and suffered no other complications during a 3-year follow-up period.

Conclusions

The introduction of endoscopic and stereotactic techniques has expanded the available treatment possibilities for posterior fossa cysts.
A standardized protocol to reduce cerebrospinal fluid shunt infection: The Hydrocephalus Clinical Research Network Quality Improvement Initiative
Authors: Kestle John R. W. , Riva-Cambrin Jay , Wellons John C. , Kulkarni Abhaya V. , Whitehead William E. , Walker Marion L. , Oakes W. Jerry , Drake James M. , Luerssen Thomas G. , Simon Tamara D. , Holubkov Richard
Published: July 2011

Object

Quality improvement techniques are being implemented in many areas of medicine. In an effort to reduce the ventriculoperitoneal shunt infection rate, a standardized protocol was developed and implemented at 4 centers of the Hydrocephalus Clinical Research Network (HCRN).

Methods

The protocol was developed sequentially by HCRN members using the current literature and prior institutional experience until consensus was obtained. The protocol was prospectively applied at each HCRN center to all children undergoing a shunt insertion or revision procedure. Infections were defined on the basis of CSF, wound, or pseudocyst cultures; wound breakdown; abdominal pseudocyst; or positive blood cultures in the presence of a ventriculoatrial shunt. Procedures and infections were measured before and after protocol implementation.

Results

Twenty-one surgeons at 4 centers performed 1571 procedures between June 1, 2007, and February 28, 2009. The minimum follow-up was 6 months. The Network infection rate decreased from 8.8% prior to the protocol to 5.7% while using the protocol (p = 0.0028, absolute risk reduction 3.15%, relative risk reduction 36%). Three of 4 centers lowered their infection rate. Shunt surgery after external ventricular drainage (with or without prior infection) had the highest infection rate. Overall protocol compliance was 74.5% and improved over the course of the observation period. Based on logistic regression analysis, the use of BioGlide catheters (odds ratio [OR] 1.91, 95% CI 1.19–3.05; p = 0.007) and the use of antiseptic cream by any members of the surgical team (instead of a formal surgical scrub by all members of the surgical team; OR 4.53, 95% CI 1.43–14.41; p = 0.01) were associated with an increased risk of infection.

Conclusions

The standardized protocol for shunt surgery significantly reduced shunt infection across the HCRN. Overall protocol compliance was good. The protocol has established a common baseline within the Network, which will facilitate assessment of new treatments. Identification of factors associated with infection will allow further protocol refinement in the future.
Middle cerebral artery aneurysms in children: case series and review
Authors: Fulkerson Daniel H. , Voorhies Jason M. , Payner Troy D. , Leipzig Thomas J. , Horner Terry G. , Redelman Kathleen , Cohen-Gadol Aaron A.
Published: July 2011

Object

Pediatric intracranial aneurysms are rare lesions that differ from their adult counterparts. Aneurysms involving the middle cerebral artery (MCA) are particularly challenging to treat in children, as they are often fusiform and cannot undergo direct clipping alone. The authors recently treated a patient with a heavily calcified, dysplastic, left-sided MCA aneurysm. The present study was performed to evaluate the authors' previous operative and follow-up experience with these difficult lesions.

Methods

The authors performed a review of a prospectively maintained database of all aneurysms treated at Methodist Hospital in Indianapolis, Indiana, from January 1990 through November 2010. Relevant operative notes, clinical charts, and radiological reports were reviewed for all patients 18 years of age or younger.

Results

A total of 2949 patients with aneurysms were treated over the study period, including 28 children (0.95%). Seven children harbored MCA aneurysms. Five of these 7 aneurysms (71.4%) were fusiform. Two patients were treated with direct clipping, 2 underwent parent vessel occlusion without bypass, and 3 underwent aneurysm trapping with extracranial-intracranial vessel bypass. Long-term follow-up data were available in 6 cases. All 6 patients had a 1-year follow-up Glasgow Outcome Scale score of 5. Long-term radiological follow-up was available in 4 patients. One patient required a reoperation for a recurrent aneurysm 4 years after the initial surgery.

Conclusions

Middle cerebral artery aneurysms in children are often fusiform, giant, and incorporate the origins of proximal artery branches. Direct clipping may not be possible; trapping of the lesion may be required. Children seem to tolerate surgical trapping with or without bypass extremely well. Aggressive therapy of these rare lesions in children is warranted, as even patients presenting with a poor clinical grade may have excellent outcomes. Long-term surveillance imaging is necessary because of the risk of aneurysm recurrence.
Kyphectomy in patients with myelomeningocele treated with pedicle screw–only constructs: case reports and review
Authors: Hwang Steven W. , Thomas Jonathan G. , Blumberg Todd J. , Whitehead William E. , Curry Daniel J. , Dauser Robert C. , Luerssen Thomas G. , Jea Andrew
Published: July 2011

Object

Significant lumbar kyphosis is frequently observed in patients with myelomeningocele and has been associated with increasing functional impairment, decreased abdominal volume, respiratory impairment, discomfort, and skin ulcerations overlying the prominent gibbus. Treatment of severe kyphotic deformities can include kyphectomy, with or without ligation of the thecal sac, with posterior spinal fixation. However, most series have reported a high rate of morbidity and complications associated with surgical intervention for correction of kyphosis in patients with myelomeningocele. The authors describe a technique in which pedicle screw (PS)–only constructs are used without transection of the thecal sac to treat severe kyphosis successfully, with minimal morbidity.

Methods

The authors retrospectively reviewed medical records and radiographic images in 2 patients with myelomeningoceles in whom kyphectomies had been performed at the authors' institution between January 2007 and July 2010. They also reviewed the existing literature for case reports or published series of patients with myelomeningocele treated with kyphectomies, to evaluate the outcomes.

Results

Both patients were male and had thoracic-level myelomeningoceles that had been repaired at birth, with associated paraplegia. Neither patient had any significant scoliotic deformity associated with the kyphosis, and both had fixation from T-9 to the ilium, which was performed using PS constructs, along with L1–2 kyphectomies. The patient in Case 1 was 20 years old and was treated for progressive kyphosis and an ulcerated nonhealing wound over the gibbus. The patient in Case 2 was 10 years old and was treated for progressive pain and functional impairment. The 2 patients had a mean correction of 63%, with a mean correction of kyphotic deformity from 136° to 51°. Neither patient developed any complication in the short term postoperatively, whereas published series have reported high complication rates, including wound infection, poor wound healing, CSF leakage, pseudarthrosis, and shunt malfunction.

Conclusions

Severe kyphotic deformities in patients with myelomeningocele can be safely treated using PS-only constructs without ligation of the thecal sac. Further evaluation with a larger sample and longer follow-up are needed to detect any associated complications, such as proximal junctional kyphosis. Further evaluation may also validate whether PS-only constructs permit successful outcomes with a shorter construct and fewer instrumented levels.
Diagnosis and treatment of ossification of the ligamentum flavum associated with dural ossification
Authors: Sun Xin-Zhi , Chen Zhong-Qiang , Qi Qiang , Guo Zhao-Qing , Sun Chui-Guo , Li Wei-Shi , Zeng Yan
Published: July 2011

Object

In this paper, the authors aimed to summarize the clinical characteristics of ossification of the ligamentum flavum (OLF) associated with dural ossification (DO) and to identify improved methods for preoperative diagnosis.

Methods

Thirty-six patients who had undergone OLF surgery between February 2005 and September 2009 were included in this retrospective study. The patients were divided into 2 groups: one that included patients with intraoperative evidence of DO and a second group that included patients without DO. The clinical features of DO were summarized and the neurological status of the patients was evaluated pre- and postoperatively.

Results

The incidence rate of DO associated with OLF was 39% (14/36). The sensitivity and specificity of the tram track sign were found to be 93% and 59%, respectively. Dural ossification was found among 86% of the patients with tuberous type Sato classification. The postoperative neurological status of patients was generally improved relative to that observed prior to surgery, although neurological recovery did not differ between the 2 groups. Cerebrospinal fluid leakage was the main complication, occurring predominantly in the patients with DO, and all leaks resolved in all patients after comprehensive treatments.

Conclusions

The tram track sign and Sato classification were found to be useful for preoperative diagnosis of DO and for determining the surgical procedure to be performed. Dural ossification had no effect on postoperative neurological recovery.