bluuebunny/crossref_metadata_2025 huggingface dataset:
Landscape metrics as a tool for evaluating scenarios for flood prevention and nature conservation
Authors: Bianchin Sylvi , Richert Elke , Heilmeier Hermann , Merta Mariusz , Seidler Christina
Published: June 2011

Within the framework of the project "Flood Prevention and Nature Conservation in the Weisseritz area" ("HochNatur"), a method including landscape metrics was developed and applied to assess and to compare different land use scenarios with regard to flood prevention and nature conservation. For the analysis, two sub-catchments strongly differing in land use within the Weisseritz catchment (Eastern Erzgebirge, Saxony, Germany) were selected. The first step of the evaluation procedure was a biotope assessment using three assessment criteria (naturalness, substitutability, rareness/endangerment). However, the biotope assessment did not yield any information about spatial distribution or the structural composition of the landscape. Therefore, landscape metrics were applied to analyse the structural and biotope type diversity at the landscape scale. Different landscape metrics (Shannon/Weaver diversity index, mean patch size index, Interdispersion/Juxtaposition index) and a weighting system were used to compare the different land use scenarios and the current state. The analysed catchment areas differ substantially in terms of their current state and potential measures regarding flood prevention and nature conservation depending on the location and distribution of biotope types. It was demonstrated that this method can be used for small catchment areas regardless of their land use for assessing, analysing and comparing different land use scenarios for a specific area.
Efficacy of Collaborative Strategic Reading With Middle School Students
Authors: Vaughn Sharon , Klingner Janette K. , Swanson Elizabeth A. , Boardman Alison G. , Roberts Greg , Mohammed Sarojani S. , Stillman-Spisak Stephanie J.
Published: June 2011

The authors conducted an experimental study to examine the effects of collaborative strategic reading and metacognitive strategic learning on the reading comprehension of students in seventh- and eighth-grade English/language arts classes in two sites (Texas, Colorado) and in three school districts. Students were randomly assigned to classes and then classes were randomly assigned to treatment or business-as-usual comparison groups. If a teacher had an uneven number of classes, we assigned extra classes to treatment. The total number of classes randomized was 61, with 34 treatment and 27 comparison. Treatment students received a multicomponent reading comprehension instruction (collaborative strategic reading) from their English/language arts/reading teachers that included teaching students to apply comprehension strategies in collaborative groups for 18 weeks, with approximately two sessions per week. Findings indicated significant differences in favor of the treatment students on the Gates-MacGinitie Reading Comprehension Test but not on reading fluency.
Revisiting Professional Learning Communities to Increase College Readiness
Authors: Bausmith Jennifer Merriman , Barry Carol
Published: June 2011

For over a decade, professional learning communities (PLCs) have been touted as an effective way to build upon the knowledge and skills of experienced teachers, yet much of the evidence base is derived from self-reports by practitioners. Although several generations of school reform (the standards movement, No Child Left Behind, and now the Common Core State Standards) have cited improving teacher effectiveness as key to improving student achievement, little change has occurred in the nature of professional development. This article argues that professional development generally, and PLCs in particular, would benefit from the insights gleaned from the extensive literature on teacher expertise that focuses on how well teachers understand the content they teach and how well they understand how students learn that content.
Assessing the Quality of the Common Core State Standards for Mathematics
Authors: Cobb Paul , Jackson Kara
Published: June 2011

The authors comment on Porter, McMaken, Hwang, and Yang’s recent analysis of the Common Core State Standards for Mathematics by critiquing their measures of the focus of the standards and the absence of an assessment of coherence. The authors then consider whether the standards are an improvement over most state mathematics standards by discussing whether the core mathematics ideas on which they focus are appropriate, whether individual standards are organized into coherent learning progressions, and whether their implementation is feasible. They question whether schools and districts currently have the capacity to support effective implementation, and they call for improvement-oriented investigations that can inform the development of effective implementation models.
Issues in Analyzing Alignment of Language Arts Common Core Standards With State Standards
Authors: Beach Richard W.
Published: June 2011

This commentary on Porter, McMaken, Hwang, and Yang’s “Common Core Standards: The New U.S. Intended Curriculum,” which finds a lack of alignment between the Common Core State Standards and state standards and assessments, suggests possible reasons for the lack of alignment. It also offers possible reasons for Porter et al.’s finding of a lack of focus in the standards. It raises questions about the use of a cognitive-processing framework for conducting content analysis of the standards.
Assessing the Common Core Standards
Authors: Porter Andrew , McMaken Jennifer , Hwang Jun , Yang Rui
Published: June 2011

This article responds to comments on the authors’ Educational Researcher article “Common Core Standards: The New U.S. Intended Curriculum” (April 2011). The authors note points of agreement and difference with the commentators. They observe that Cobb and Jackson, in their response, and Beach, in his, appear to accept the authors’ methods and findings, although these commentators suggest additional perspectives that should be brought to bear when addressing quality and change. The authors agree with Beach, Cobb, and Jackson that quality is difficult to define and assess, and they state that additional conceptualizations of mathematics and English language arts content and additional conceptualizations of how to define and measure alignment among content standards, materials, assessments, and instruction should be explored. They look forward to renewed efforts in this research area.
Estimation and Identification of the Complier Average Causal Effect Parameter in Education RCTs
Authors: Schochet Peter Z. , Chiang Hanley S.
Published: June 2011

In randomized control trials (RCTs) in the education field, the complier average causal effect (CACE) parameter is often of policy interest, because it pertains to intervention effects for students who receive a meaningful dose of treatment services. This article uses a causal inference and instrumental variables framework to examine the identification and estimation of the CACE parameter for two-level clustered RCTs. The article also provides simple asymptotic variance formulas for CACE impact estimators measured in nominal and standard deviation units. In the empirical work, data from 10 large RCTs are used to compare significance findings using correct CACE variance estimators and commonly used approximations that ignore the estimation error in service receipt rates and outcome standard deviations. The key finding is that the variance corrections have very little effect on the standard errors of standardized CACE impact estimators. Across the examined outcomes, the correction terms typically raise the standard errors by less than 1%, and change p values at the fourth or higher decimal place.

Manuscript received April 16, 2010 Revision received April 26, 2010 Accepted May 24, 2010
Effect Sizes in Three-Level Cluster-Randomized Experiments
Authors: Hedges Larry V.
Published: June 2011

Research designs involving cluster randomization are becoming increasingly important in educational and behavioral research. Many of these designs involve two levels of clustering or nesting (students within classes and classes within schools). Researchers would like to compute effect size indexes based on the standardized mean difference to compare the results of cluster-randomized studies with other studies and to combine information across studies in meta-analyses. This article addresses the problem of defining effect sizes in designs with two levels of clustering and computing estimates of those effect sizes and their standard errors from information that is likely to be reported in journal articles. Five effect sizes are defined corresponding to different standardizations. Estimators of each effect size index are also presented along with their sampling distributions (including standard errors).
An Investigation of Experience in L2 Phonology: Does Quality Matter More than Quantity?
Authors: Moyer Alene
Published: June 2011

This study examines the significance of language use for second language (L2) accent and tests it against factors such as length of residence (LOR) and age of onset (AO). Participants include 42 non-native speakers of English and 8 native speaker controls. Read-aloud items and guided free-speaking tasks are rated on a 5-point scale. Correlation analyses confirm the significance of AO, LOR, and experiential factors such as first language (L1) use, breadth of L2 use across multiple modes, and especially domain-based L2 use, such as personal, interactive contact with native speakers of the target language. Results suggest that experiential quality has a more significant impact on accent than experiential quantity and that, according to multiple regression models, experience is independent of the influences of AO and LOR. Based on these analyses, closer investigations of language experience and its connections to LOR are recommended.
The Power of Story in the ESL Classroom
Authors: Nicholas Bonnie J. , Rossiter Marian J. , Abbott Marilyn L.
Published: June 2011

Although considerable research has examined the use of literature in the second language (L2) classroom, there has been less investigation into the integration of learners' personal stories in the English as a second language (ESL) classroom. Following Wajnryb's (2003) categorizations of story as language learning, genre, and the creation of what she termed a ‘storied classroom,’ this study explores the ways in which learners' stories are used in the ESL classroom. Five ESL instructors and nine adult ESL learners enrolled in ESL classes at a settlement agency in Edmonton were interviewed about the practice, benefits, and challenges of incorporating personal stories into the L2 classroom. Participants perceived that story promoted language learning, an understanding of genre, and community building, while also enhancing authenticity, affect, and motivation. This article provides guidelines and recommends resources for using personal story in the adult ESL classroom.
Hemodynamic instability following carotid artery stenting
Authors: Kojuri Javad , Ostovan Mohammad Ali , Zamiri Nima , Farshchizarabi Sara , Varavipoor Bahman
Published: June 2011

Object

Postprocedural hypotension and bradycardia are important complications of carotid artery stenting (CAS) and are referred to as hemodynamic instability (HI). However, the incidence and impact of HI on the short-term prognosis of patients have been of a large debate.

Methods

Twenty-seven patients were selected based on NASCET criteria, and they underwent CAS between September 2008 and September 2009. Continuous electrocardiography monitoring and supine blood pressure (BP) monitoring were performed before and after stent deployment and on the following day to detect HI, defined as systolic BP lower than 90 mm Hg or a heart rate lower than 60 bpm. Patients were asked to perform a Valsalva maneuver before and after stent deployment. The Valsalva ratios (VRs) along with other demographic and procedural data were documented and compared between patients with and without incidence of HI.

Results

Seventeen patients (63%) developed HI after CAS. The degree of stenosis was found to have a significant correlation with occurrence of HI (p < 0.006). No other risk factor or demographic data showed any correlation with HI. The VRs were significantly lower in the HI group compared with the non-HI group, indicating a significant autonomic dysfunction (p < 0.003). During follow-up, 1 patient (4.3%) developed major stroke, and the remaining patients were symptom free.

Conclusions

Hemodynamic instability occurs frequently after CAS, but it seems to be a benign phenomenon and does not increase the risk of mortality or morbidity in the short term. A VR at rest less than 1.10, baseline autonomic dysfunction, and degree of carotid artery stenosis can be used as measures for predicting HI after CAS.
The relationships between endothelial nitric oxide synthase polymorphisms and the formation of intracranial aneurysms in the Korean population
Authors: Kim Tae Gon , Kim Nam Keun , Baek Min Jung , Huh Ryoung , Chung Sang Sup , Choi Joong Uhn , Yu So Young
Published: June 2011

Object

Some genetic factors are known to be associated with the formation of cerebral aneurysms in the Caucasian population. One of these factors is endothelial nitric oxide synthase (eNOS) gene polymorphisms. Endothelial nitric oxide synthase genes encode eNOS, which synthesizes NO from l-arginine. There continues to be controversy about the relationships between eNOS gene polymorphisms and the formation of intracranial aneurysms. In this study, the authors evaluated these relationships in the Korean population.

Methods

Three eNOS polymorphisms (eNOS 27VNTR, T786C, and G894T) were genotyped in 96 patients with ruptured aneurysms, 53 patients with unruptured aneurysms, and in 121 volunteers via polymerase chain reaction–restriction fragment length polymorphism analysis.

Results

The mean ages of the patients and healthy volunteers were 52.9 ± 12.3 years and 55.2 ± 9.1 years, respectively. The patient group was composed of 56 men and 93 women, and the healthy volunteer group was composed of 46 men and 75 women. Only the incidence of smoking history was significantly higher in the patient group than in the control group (p = 0.001). The genotypic frequencies for the 3 eNOS gene polymorphisms were in agreement with those predicted by Hardy-Weinberg equilibrium. There were no significant associations between the eNOS recessive models and the formation of an aneurysm. The authors found no genotypic differences between similar races among patients with aneurysms.

Conclusions

The present study shows that eNOS 27VNTR, T786C, and G894T polymorphisms cannot be used as indicators of the formation of intracranial aneurysms in Korean patients. To confirm these findings an additional analyses might need to be performed using a larger sample size. There were no differences in the genotypic distributions and allelic frequencies between similar races among patients with aneurysms, which were the same in previously reported normal populations.
Endovascular recanalization of symptomatic flow-limiting cervical carotid dissection in an isolated hemisphere
Authors: Schirmer Clemens M. , Atalay Basar , Malek Adel M.
Published: June 2011

Object

Internal carotid artery dissection (ICAD) is a common cause of stroke in young patients, which may lead to major transient or permanent disability. Internal carotid artery dissection may occur spontaneously or after trauma and may present with a rapid neurological deterioration or with hemodynamic compromise and a delayed and unstable neurological deficit. Endovascular intervention using stent angioplasty can be used as an alternative to anticoagulation and open surgical therapy in this setting to restore blood flow through the affected carotid artery.

Methods

The authors present the cases of 2 patients with flow-limiting symptomatic ICAD leading to near-complete occlusion and without sufficient collateral supply. Both patients had isolated cerebral hemispheres without significant blood flow from the anterior or posterior communicating arteries. In both cases, the patients demonstrated blood pressure–dependent subacute unstable neurological deficits as a result of the hemodynamic compromise resulting from the dissection.

Results

Both patients underwent careful microwire-based selection of the true lumen followed by confirmatory microinjection and subsequent exchange-length microwire-based recanalization using tandem telescoping endovascular stenting. In both cases the neurological state improved, and no permanent neurological deficit ensued.

Conclusions

The treatment of ICAD may be difficult in patients with subacute unstable neurological deficits related to symptomatic hypoperfusion, especially in the setting of a hemodynamically isolated hemisphere. Anticoagulation alone may be insufficient in these patients. Although there is no widely accepted guideline for the treatment of ICAD, the authors recommend stent-mediated endovascular recanalization in cases of symptomatic flow-limiting hemodynamic compromise, especially in cases of an isolated hemisphere lacking sufficient communicating artery compensatory perfusion.
Endoscopically assisted intratumoral embolization of juvenile nasopharyngeal angiofibroma using Onyx
Authors: Aziz-Sultan Mohammad Ali , Moftakhar Roham , Wolfe Stacey Quintero , Elhammady Mohamed Samy , Herman Björn , Farhat Hamad
Published: June 2011

Juvenile nasopharyngeal angiofibromas are vascular tumors that may make resection difficult and potentially dangerous. Preoperative embolization is frequently used to decrease surgical morbidity and blood loss. Embolization has typically been performed via a transarterial route using a variety of embolic materials. The authors present a case in which endoscopic assistance was used for direct transnasal tumor puncture and intratumoral embolization using the liquid embolic agent Onyx. In this case there was excellent infiltration of the parenchymal vasculature with complete angiographic obliteration. There were no complications related to the embolization. The tumor was resected with minimal blood loss. To the authors' knowledge, there have been no previous reports of this novel direct intratumoral embolization technique using endoscopic guidance.
Sources of variability in computed tomography perfusion: implications for acute stroke management
Authors: Zussman Benjamin , Jabbour Pascal , Talekar Kiran , Gorniak Richard , Flanders Adam E.
Published: June 2011

Object

Although dynamic, first-pass cerebral CT perfusion is used in the evaluation of acute ischemic stroke, a lack of standardization restricts the value of this imaging modality in clinical decision-making. The purpose of this study was to comprehensively review the reported sources of variability and error in cerebral CT perfusion results.

Methods

A systematic literature review was conducted, 120 articles were reviewed, and 23 published original research articles were included. Sources of variability and error were thematically categorized and presented within the context of the 3 stages of a typical CT perfusion study: data acquisition, postprocessing, and results interpretation.

Results

Seven factors that caused variability were identified and described in detail: 1) contrast media, the iodinated compound injected intravascularly to permit imaging of the cerebral vessels; 2) data acquisition rate, the number of images obtained by CT scan per unit time; 3) user inputs, the subjective selections that operators make; 4) observer variation, the failure of operators to repeatedly measure a perfusion parameter with precision; 5) software operational mode, manual, semiautomatic, or automatic; 6) software design, the mathematical algorithms used to perform postprocessing; and 7) value type, absolute versus relative values.

Conclusions

Standardization at all 3 stages of the CT perfusion study cycle is warranted. At present, caution should be exercised when interpreting CT perfusion results as these values may vary considerably depending on a variety of factors. Future research is needed to define the role of CT perfusion in clinical decision-making for acute stroke patients and to determine the clinically acceptable limits of variability in CT perfusion results.
Symptomatic intracranial arterial disease: incidence, natural history, diagnosis, and management
Authors: Vellimana Ananth K. , Ford Andria L. , Lee Jin-Moo , Derdeyn Colin P. , Zipfel Gregory J.
Published: June 2011

Symptomatic intracranial arterial disease is associated with a high rate of recurrent ischemic events. The management of this condition is controversial, with some advocating medical therapy as a sole means of treatment and others recommending endovascular therapy in addition to best medical management. In rare cases, surgical intervention is considered. A thorough review of the available literature was performed, and treatment recommendations based on these data are provided.
Evidence-based treatment of carotid artery stenosis
Authors: Young Kate C. , Jain Anunaya , Jain Minal , Replogle Robert E. , Benesch Curtis G. , Jahromi Babak S.
Published: June 2011

Carotid atheromatous disease is an important cause of stroke. Carotid endarterectomy (CEA) is a well-established option for reducing the risk of subsequent stroke due to symptomatic stenosis (> 50%). With adequately low perioperative risk (< 3%) and sufficient life expectancy, CEA may be used for asymptomatic stenosis (> 60%). Recently, carotid angioplasty and stent placement (CAS) has emerged as an alternative revascularization technique. Trial design considerations are discussed in relation to trial results to provide an understanding of why some trials were considered positive whereas others were not. This review then addresses both the original randomized studies showing that CEA is superior to best medical management and the newer studies comparing the procedure to stent insertion in both symptomatic and asymptomatic populations. Additionally, recent population-based studies show that improvements in best medical management may be lowering the stroke risk for asymptomatic stenosis. Finally, the choice of revascularization technique is discussed with respect to symptom status. Based on current evidence, CAS should remain limited to specific indications.
Improving patient selection for endovascular treatment of acute cerebral ischemia: a review of the literature and an external validation of the Houston IAT and THRIVE predictive scoring systems
Authors: Ishkanian Amy A. , McCullough-Hicks Margy E. , Appelboom Geoffrey , Piazza Matthew A. , Hwang Brian Y. , Bruce Samuel S. , Hannan Lindsay M. , Connolly E. Sander , Lavine Sean D. , Meyers Philip M.
Published: June 2011

Outcome after intraarterial therapy (IAT) for acute ischemic stroke remains variable, suggesting that improved patient selection is needed to better identify patients likely to benefit from treatment. The authors evaluate the predictive accuracies of the Houston IAT (HIAT) and the Totaled Health Risks in Vascular Events (THRIVE) scores in an independent cohort and review the existing literature detailing additional predictive factors to be used in patient selection for IAT. They reviewed their center's endovascular records from January 2004 to July 2010 and identified patients who had acute ischemic stroke and underwent IAT. They calculated individual HIAT and THRIVE scores using patient age, admission National Institutes of Health Stroke Scale (NIHSS) score, admission glucose level, and medical history. The scores' predictive accuracies for good outcome (discharge modified Rankin Scale score ≤ 3) were analyzed using receiver operating characteristics analysis. The THRIVE score predicts poor outcome after IAT with reasonable accuracy and may perform better than the HIAT score. Nevertheless, both measures may have significant clinical utility; further validation in larger cohorts that accounts for differences in patient demographic characteristics, variation in time-to-treatment, and center preferences with respect to IAT modalities is needed. Additional patient predictive factors have been reported but not yet incorporated into predictive scales; the authors suggest the need for additional data analysis to determine the independent predictive value of patient admission NIHSS score, age, admission hyperglycemia, patient comorbidities, thrombus burden, collateral flow, time to treatment, and baseline neuroimaging findings.
Moyamoya disease: functional and neurocognitive outcomes in the pediatric and adult populations
Authors: Weinberg David G. , Rahme Rudy J. , Aoun Salah G. , Batjer H. Hunt , Bendok Bernard R.
Published: June 2011

Object

Moyamoya disease is an occlusive cerebrovascular disorder commonly resulting in neurocognitive impairment. The cognitive outcome parameters commonly affected are intelligence, memory, executive function, and quality of life. In this paper, the authors review the existing literature on cognitive and clinical outcomes in adult and pediatric moyamoya populations separately.

Methods

A systematic review of the cognitive and clinical outcome literature was performed using the PubMed/MEDLINE database. Outcomes data were contrasted between adult and pediatric populations.

Results

Intelligence is the main cognitive outcome parameter affected in pediatric patients with moyamoya disease, whereas adults most commonly suffer from executive function impairment. Memory has not been studied sufficiently in pediatric patients, and its dysfunction in the adult population remains controversial. Quality of life has not been studied appropriately in either population. Surgical revascularization is the only beneficial treatment option, and a combination of direct and indirect bypass techniques has shown benefit, but the impact on the above-mentioned parameters has not been sufficiently elucidated.

Conclusions

Moyamoya disease affects the cognition and daily function in pediatric patients to a greater extent than in adult patients. Due to the rarity of the disease, there is a distinct lack of high-level evidence regarding cognitive and clinical outcomes.
Moyamoya disease: a review of histopathology, biochemistry, and genetics
Authors: Weinberg David G. , Arnaout Omar M. , Rahme Rudy J. , Aoun Salah G. , Batjer H. Hunt , Bendok Bernard R.
Published: June 2011

Object

Moyamoya disease (MMD) is a rare cerebrovascular disorder involving stenosis of the major vessels of the circle of Willis and proximal portions of its principal branches. Despite concerted investigation, the pathophysiology of the disorder has not been fully elucidated. Currently, the major proteins believed to play an active role in the pathogenesis include vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), transforming growth factor–β1 (TGFβ1), and granulocyte colony-stimulating factor (G-CSF). In terms of the genetics, recent literature suggests a low penetrance autosomal dominant or polygenic mode of transmission involving chromosomes 3, 6, 8, 12, and 17 for familial MMD. This review summarizes the current knowledge on the histopathology, pathophysiology and genetics of MMD.

Methods

A PubMed/Medline systematic study of the literature was performed, from which 45 articles regarding MMD pathophysiology were identified and analyzed.

Conclusions

Moyamoya disease is characterized by the intimal thickening and media attenuation of the proximal vessels of the circle of Willis as well as the development of an aberrant distal vascular network. The primary proteins that are currently implicated in the pathophysiology of MMD include VEGF, bFGF, HGF, TGFβ1, and G-CSF. Furthermore, the current literature on familial MMD has pointed to a low penetrance autosomal dominant or polygenic mode of transmittance at loci on chromosomes 3, 6, 8, 12, and 17.
Bilateral subthalamic nucleus deep brain stimulation for dopa-responsive dystonia in a 6-year-old child
Authors: Tormenti Matthew J. , Tomycz Nestor D. , Coffman Keith A. , Kondziolka Douglas , Crammond Donald J. , Tyler-Kabara Elizabeth C.
Published: June 2011

Tyrosine hydroxylase (TH) deficiency is a rare autosomal recessive metabolic disease that results in the decreased production of catecholamines. Standard treatment relies on combinations of levodopa and carbidopa, anticholinergic agents, serotonergic agonists, and monamine oxidase B inhibitors. Unfortunately, severely affected children often require escalating doses of medication and suffer from dyskinesias as well as significant on/off symptomatology.

The authors present a case of medically intractable dopa-responsive dystonia in a 6-year-old boy whose condition significantly improved with bilateral subthalamic nucleus deep brain stimulation. This case is unique in its novel approach to tyrosine hydroxylase deficiency and the young age of the patient.
Minimally invasive lumbar microdiscectomy in pediatric patients: a series of 6 patients
Authors: Thomas Jonathan G. , Hwang Steven W. , Whitehead William E. , Curry Daniel J. , Luerssen Thomas G. , Jea Andrew
Published: June 2011

Object

Lumbar disc herniation is rare in the pediatric age group, but may still cause a significant amount of pain and disability. Whereas minimally invasive surgery (MIS) for lumbar disc herniation is routinely performed in adults, it has not yet been described in the pediatric population. The purpose of this study was to describe the surgical results of pediatric MIS-treated lumbar disc disease.

Methods

The authors retrospectively reviewed a series of 6 consecutive cases of lumbar microdiscectomy performed using MIS techniques between April 2008 and July 2010. Presenting symptoms, physical examination findings, and preoperative MR imaging results were obtained from medical records. Perioperative results, including blood loss, length of hospital stay, and complications were assessed. Findings at latest follow-up evaluation were also recorded.

Results

This report represents the first surgical series regarding pediatric lumbar microdiscectomies performed using MIS. The mean patient age was 16 years (range 14–17 years); there were 4 girls and 2 boys. Preoperative signs and symptoms of radiculopathic pain were notable in 100% of patients, and myotomal weakness was noted in 33% of patients. The first line of treatment in all patients was a period of conservative management lasting an average of 11.5 months (range 6–12 months). The mean intraoperative blood loss was 10.8 ml, and the mean postoperative length of stay was 1.3 days. There were no complications in this small series.

Conclusions

The treatment of pediatric lumbar disc herniation by using MIS techniques can be safe and efficacious. However, further study with a larger number of patients and longer follow-up is needed to compare outcomes between MIS and open microdiscectomies.
Perioperative seizure incidence and risk factors in 223 pediatric brain tumor patients without prior seizures
Authors: Hardesty Douglas A. , Sanborn Matthew R. , Parker Whitney E. , Storm Phillip B.
Published: June 2011

Object

The incidence of, and risk factors for, perioperative seizures and the need for perioperative antiepileptic drugs (AEDs) in previously seizure-free children with brain tumors remains unclear. The authors have undertaken a review of previously seizure-free pediatric patients with brain tumors undergoing resection to identify the incidence of seizures in the perioperative period, and to characterize risk factors for perioperative seizures in this population.

Methods

A retrospective review was conducted of all patients between 0 and 19 years of age without prior seizures who underwent intracranial tumor resection at the authors' institution between January 2005 and December 2009.

Results

Of the 223 patients undergoing 229 operations, 7.4% experienced at least 1 clinical seizure during the surgical admission. Over half of all tumors were supratentorial. Only 4.4% of patients received prophylactic AEDs. Independent factors associated with perioperative seizures included supratentorial tumor, age < 2 years, and hyponatremia due to syndrome of inappropriate antidiuretic hormone or cerebral salt wasting. Tumor type, lobe affected, operative blood loss, and length of surgery were not independently associated with seizure incidence.

Conclusions

Perioperative seizures in previously seizure-free children undergoing resection of brain tumors are associated with supratentorial tumor location, age < 2 years, and postoperative hyponatremia. Perioperative seizures are not associated with tumor pathology, tumor size, or frontotemporal location. Due to the low incidence of seizures in this series in patients more than 2 years old with normal serum sodium, the authors recommend that pediatric patients with brain tumors not routinely receive perioperative prophylactic AEDs. However, the role for prophylaxis in patients younger than 2 years of age deserves further study.
Complications of endoscopic third ventriculostomy
Authors: Bouras Triantafyllos , Sgouros Spyros
Published: June 2011

Object

Endoscopic third ventriculostomy (ETV) is an established treatment for hydrocephalus. Most studies focus on success rate, and complications are insufficiently documented. The aim of this study was to perform a systematic review of ETV complications.

Methods

A Medline search discovered 34 series of ETV with detailed complications reports (17 series involving exclusively pediatric patient populations, 6 series involving exclusively adults, and 11 series involving mixed adult and pediatric populations).

Results

The analysis included 2985 ETVs performed in 2884 patients. The cause of hydrocephalus was aqueductal stenosis in 29.3% of patients, tumor in 37.6%, meningomyelocele in 7.6%, cysts in 2.6%, cerebellar infarct in 0.9%, Dandy-Walker malformation in 0.6%, and Chiari malformation Type I in 0.4%; 7.4% of the patients had posthemorrhagic hydrocephalus, 1.8% had postinfectious hydrocephalus, and 1.2% had normal pressure hydrocephalus. Hydrocephalus was due to other causes in 1.3% of cases and the cause was not reported in 9.8%. The overall complication rate was 8.5%. The rate of permanent morbidity was 2.38%; the rate of permanent neurological complications was 1.44% (hemiparesis, gaze palsy, memory disorders, altered consciousness), and the rate of permanent hormonal morbidity was 0.94% (diabetes insipidus, weight gain, precocious puberty). The rate of intraoperative hemorrhage rate was 3.7%; the rate of severe intraoperative hemorrhage was 0.6% (including a 0.21% rate of basilar rupture). The rate for intraoperative neural injury (thalamic, forniceal, hypothalamic, and midbrain injuries) was 0.24%. Central nervous system infections occurred in 1.81% of cases, CSF leak in 1.61%, and postoperative intracranial hematomas in 0.81% of cases. The early postoperative mortality rate was 0.21% (6 patients died; 2 of sepsis and 4 of hemorrhage). Another 2 children suffered delayed “sudden death” (one after 25 months and the other after 60 months), caused by acute hydrocephalus due to stoma occlusion. There were no significant differences between series involving pediatric or adult patient populations or series with fewer than 100 or more than 100 patients. All reported deaths were in series involving more than 100 patients.

Conclusions

Endoscopic third ventriculostomy can be regarded as a low-complication procedure, with an overall complication rate of 8.5%, permanent morbidity rate of 2.4%, mortality rate of 0.21%, and delayed “sudden death” rate of 0.07%.
Interhemispheric endoscopic resection of large intraventricular and thalamic tumors
Authors: Sood Sandeep , Nundkumar Neelesh , Ham Steven D.
Published: June 2011

A transfrontal route is the traditional endoscopic approach to intraventricular tumors. Small lesions can be biopsied using the parallel port channel of the endoscope. For larger tumors a ventriculoport can be used for resection. This technique nevertheless requires traversing the brain tissue, is difficult in the setting of small ventricles, and allows only limited mobility. The authors describe the endoscopic resection of large intraventricular tumors via an interhemispheric route using rigid suction with a mounted endoscope, and thus circumventing some of the problems with the traditional approach.
Balloon-assisted Onyx embolization of cerebral single-channel pial arteriovenous fistulas
Authors: Newman C. Benjamin , Hu Yin C. , McDougall Cameron G. , Albuquerque Felipe C.
Published: June 2011

Object

Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risks of hemorrhage and neurological deficit. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. The authors describe a novel endovascular treatment strategy that was used successfully to treat 2 pediatric patients with a pial AVF, and they discuss the technical nuances specific to their treatment strategy.

Methods

A single-channel high-flow pial AVF was diagnosed in 2 male patients (6 and 17 years of age). Both patients were treated with endovascular flow arrest using a highly conformable balloon followed by Onyx infusion for definitive closure of the fistula.

Results

Neither patient suffered a complication as a result of the procedure. At the 6-month follow-up in both cases, the simple discontinuation of blood flow had resulted in durable obliteration of the fistula and stable or improved neurological function.

Conclusions

Onyx can be delivered successfully into high-flow lesions after flow arrest to allow a minimally invasive and durable treatment for pial AVFs.
Surgical management of tumors producing the thalamopeduncular syndrome of childhood
Authors: Broadway S. Jared , Ogg Robert J. , Scoggins Matthew A. , Sanford Robert , Patay Zoltan , Boop Frederick A.
Published: June 2011

Object

Thalamopeduncular tumors arise at the junction of the inferior thalamus and cerebral peduncle and present with a common clinical syndrome of progressive spastic hemiparesis. Pathologically, these lesions are usually juvenile pilocytic astrocytomas and are best treated with resection with the intent to cure. The goals of this study are to define a common clinical syndrome produced by thalamopeduncular tumors and to discuss imaging characteristics as well as surgical adjuncts, intraoperative nuances, and postoperative complications relating to the resection of these neoplasms.

Methods

The authors present a retrospective review of their experience with 10 children presenting between 3 and 15 years of age with a thalamopeduncular syndrome. Formal preoperative MR imaging was obtained in all patients, and diffusion tensor (DT) imaging was performed in 9 patients. Postoperative MR imaging was obtained to evaluate the extent of tumor resection. A prospective analysis of clinical outcomes was then conducted by the senior author.

Results

Pilocytic astrocytoma was the pathological diagnosis in 9 cases, and the other was fibrillary astrocytoma. Seven of 9 pilocytic astrocytomas were completely resected. Radical surgery was avoided in 1 child after DT imaging revealed that the corticospinal tract (CST) coursed through the center of the tumor, consistent with the infiltrative nature of fibrillary astrocytoma as identified by stereotactic biopsy. In 8 patients, tractography served as an important adjunct for designing a surgical approach that spared the CST. In 6 cases the CSTs were pushed anterolaterally, making a transsylvian approach a poor choice, as was evidenced by the first patient in the series, who underwent operation prior to the advent of tractography, and who awoke with a dense contralateral hemiparesis. Thus, subsequent patients with this deviation pattern underwent a transcortical approach via the middle temporal gyrus. One patient exhibited medial deviation of the tracts and another had lateral deviation, facilitating a transtemporal and a transfrontal approach, respectively.

Conclusions

The thalamopeduncular syndrome of progressive spastic hemiparesis presenting in children with or without symptoms of headache should alert the examiner to the possibility of a tumoral involvement of CSTs. Preoperative tractography is a useful adjunct to surgical planning in tumors that displace motor pathways. Gross-total resection of pilocytic astrocytomas usually results in cure, and therefore should be entertained when developing a treatment strategy for thalamopeduncular tumors of childhood.
Stand und Perspektiven der Nutzung neuer Fernerkundungstechnologien im Waldbereich | Status and perspectives of the application of new remote sensing technologies in forestry
Authors: Koch Barbara
Published: June 2011

Remote sensing has been used in forestry for a long time. Aerial photography has mainly been used to support national and operational inventories and medium resolution satellite data for large area inventories. Today through the availability of new technologies there are greatly extended possibilities for remote sensing in the forestry sector. The major change is the better availability of 3-D information, which allows a much better modelling of forests and forest attributes. The paper presents an overview of the newest remote sensing technologies, such as the systems carried by satellite which can be used to record changes or degradation in the area covered by forest for the global forestry resources assessment of the UN World Food and Agriculture Organisation or are examined in connection with the United Nations REDD program. Besides these, other small scale applications are presented based on optical or laser systems carried by aircraft. The article finishes with an outlook on expected developments in the near future. It is expected that the future of forestry remote sensing will be characterized above all by the combination of information obtained from diverse sources, such as data based on terrestrial and on remotely sensed sources.
Imagology Meets Children's Literature
Authors: O'Sullivan Emer
Published: June 2011

Since the 1970s, children's literature research has developed a number of approaches, from simple ideological criticism to more sophisticated applications of postcolonial theory, to analyse how, and to what end, members of other national, cultural, racial and ethnic groups are represented in texts for children. However, a field of study within comparative literature, imagology, which specifically addresses the cultural construction and literary representation of national characters in literature, has not yet made much impact. This review article will present its origins and methods of investigation as well as sketch areas in children's literature of imagological interest, which have been or are still waiting to be productively addressed, to show what the domain can gain from this approach.
Harry Potter – National Hero and National Heroic Epic
Authors: Köhler Ulrike Kristina
Published: June 2011

Joanne K. Rowling's teenage wizard has enchanted readers all over the globe and Harry Potter can truly be called an international hero. However, as I will argue, he is also very much an English national hero, complying with the national auto-image of the English gentleman as well as with the idea of Christian masculinity, another English auto-image holding that outdoor activity is more character-building than book learning. I will also show that the series can be read as a national heroic epic in two respects. First, Harry Potter, alias Robin Hood, has to fight the Norman yoke, an English myth haunting the nation since the Norman invasion in 1066. The series displays as a national model an apparently paternalistic Anglo-Saxon feudal society marked by tolerance and liberty as opposed to foreign rule. Second, by establishing parallels to events which took place in Nazi Germany, the series takes up the idea of fighting it, which is a popular topos in British (children's) literature which serves to reinforce a positive self-image.
Youth Voices in the War Diary Business
Authors: Honeyman Susan
Published: June 2011

In the following essay I will consider young war diaries' questionable authenticity as well as the genre's fit within and struggle against a protectionist construction of youth that is reinforced by the opportunity to emphasize victimization and trauma. I will first contextualize recent diaries in contrast to the historical tradition of American juvenile war literature, then argue that the war diary mill can be seen both as a vehicle for voicing ‘authentic’ child perspectives as well as just another manipulation of these perspectives.
Portals, Agency and the Negotiation of Liminality in A Tale of Time City and Johnny and the Bomb
Authors: Zarate Andrea
Published: June 2011

This paper focuses upon the portal trope in Diana Wynne Jones's A Tale of Time City and Terry Pratchett's Johnny and the Bomb, suggesting that the portal trope is not just a practical narrative conveyance but a liminal space in which negotiation of discourse comes to the fore. In light of Bakhtin's notion of the chronotope, the portal is rendered a nexus point of time and space in which multiple discourses meet and blend. Characters, in entering a portal space, must negotiate these discourses, absorbing and appropriating them – a phenomenon that both alters the characters and the discourses themselves. From this theoretical lens, the portal trope articulates the fluidity of discourse as well as the processes of subject negotiation that characterise much of fantasy literature for children.
‘The Subtle Tree’: Idolatry and Material Memory in Surrey's Aeneid
Authors: Wilson-Lee Edward
Published: June 2011

This article looks at the translation (c.1540) of Books 2 and 4 of the Aeneid by Henry Howard, Earl of Surrey, concentrating on passages of linguistic density which surround descriptions of sacred objects and acts of interpreting and destroying them. Surrey's treatment of these urgently relevant elements of Virgil are deeply ambivalent, partaking both of the righteous iconoclasm of Reformist writers and the elegiac tones of traditionalists, and can be placed in a wider Tudor tradition of typological interpretations of Aeneid 2 by both Protestant and Catholic writers. Surrey's ambivalence is ultimately captured by the fact that his text mourns the loss of material culture while offering itself as a replacement for what has been lost.
‘El Homero español’: Translation and Shipwreck
Authors: Johnson Christopher D.
Published: June 2011

This essay interprets aspects of Luis de Góngora's Soledad primera (1613) in light of sixteenth-century translations of the Odyssey by Andreas Divus and Gonzalo Pérez, as well as topoi concerning Odysseus and shipwreck. It argues that these translations, together with versions of the hero sketched by Villalón, Covarrubias, and others, made an exemplary figure available to Góngora, whose poem of errancy ambivalently represents the Spanish voyages of discovery.
‘O that mine Adversary had written a Book!’ Translations of Catholic Literature and the Eroticization of Pain in Seventeenth-Century England
Authors: Yamamoto-Wilson John R.
Published: June 2011

This paper sets out to illustrate how Catholic literature of this period attempted to perpetuate medieval attitudes towards suffering, and demonstrate the tensions caused by translations of such literature into English. Catholic translations (such as the 1611 edition of Vicenzo Puccini's biography of Magdalena de Pazzi) contained representations of exemplary suffering, albeit with a certain sense of unease and defensiveness, while for Protestant translators (such as Paul Rycaut, translator of Baltasar Gracián's El Criticón) Catholic portrayals of suffering could not function, in English, as in any way morally edifying and are presented as simply perverse, if not actually perverted.