bluuebunny/crossref_metadata_2025 huggingface dataset:
Reconsidering counter-hegemonic dam projects: the case of the Grand Ethiopian Renaissance Dam
Authors: Tawfik Rawia
Published: March 2016

The paper questions the argument of the hydro-hegemony framework that counter-hegemonic mechanisms used by non-hegemons in transboundary rivers lead to a more equitable order of water and benefit-sharing, using the case of the Grand Ethiopian Renaissance Dam (GERD). It agrees with hydro-hegemony scholars that the GERD is a ‘game changer’ that challenges Egypt's hegemonic position, and an important step in the transition towards a new order in the Nile Basin. However, it scrutinises how Ethiopia and Egypt manage this transition through their policies to implement or contest the dam, and the conditions under which the GERD could lead to a more equitable order in the basin, and create incentives for cooperation beyond the project. It argues that Ethiopia's planning and implementation of the project, and Egypt's inconsistent response to it, have increased uncertainties about the benefits of the project to downstream countries, and even to Ethiopia, and fuelled the historical mistrust between the two countries. It suggests steps to build trust and translate the recent Declaration of Principles between the three Eastern Nile riparians into a benefit-sharing deal.
Overall Stability Analysis of Improved Buckling Restrained Braces
Authors: Yin Zhanzhong , Bu Fucheng
Published: March 2016

In order to improve the behavior of double-tube buckling restrained braces (BRBs), it is proposed to set contact rings between inner tube and outer tube of the brace. As a result, they can provide lateral constraint for the inner tube; this is the improved buckling restrained braces (IBRBs). In this paper, a program was edited by the language of MATLAB based on theoretical model formulation of IBRBs and applied to the calculation of overall stability strength capacity. Finite element models of IBRBs were carried out and both load displacement curves and strength capacity were obtained. Tests on IBRBs were also conducted. The results of numerical simulation agreed with the ones of the program and tests. It indicated that the program was reasonable so it could provide a basis for the analysis of overall stability strength capacity of these kinds of IBRBs.
Finite Element Modeling and Mechanical Behavior of Masonry-Infilled RC Frame
Authors: Deng Hongyu , Sun Baitao
Published: March 2016

During the analysis of reinforced concrete structures, the infill wall is usually simplified as a diagonal inclined strut to facilitate finite element modeling calculations. However, the actual seismic damage and single frame-filled wall pushover experimental results show that when the earthquake shear force is huge, the top of the infill wall and the beam–column connections are usually, thus the path of the force transfer will be changed. Based on this actual failure phenomenon, a new calculation model which has different contact position between the equivalent bracing walls and the frame columns is generated. Thus, the force analysis is given based on this model, the formulae for calculating the equivalent width of bracing walls, the shear bearing capacity of the wall-filled frame, and the infill wall’s actual participation in the stiffness. A finite element simulation method by ABAQUS is used to determine an empirical formula for calculating the reasonable contact position between the equivalent bracing walls and the frame columns. The verification results show that the finite element model presented in this paper is more reasonable, and the stiffness and shear resistance of infill wall should not be neglected. The calculation formula of stiffness of infill wall presented in this paper is coincided with seismic code. But the calculation formula of shear resistance of infill wall presented in seismic code is higher than the actual value, so it is suggested that calculation formula presented in this paper should be accepted.
Aerococcus christensenii as Part of Severe Polymicrobial Chorioamnionitis in a Pregnant Woman
Authors: Carlstein Catrine , Marie Søes Lillian , Jørgen Christensen Jens
Published: March 2016

Chorioamnionitis is a potentially life threatening infection of the fetal
membranes, commonly caused by ascending bacteria from the vagina and cervix. In
our case, a healthy nullipara with a term pregnancy presented clinical signs of
infection after induced labour with an intracervical balloon. Thick green and
foul smelling amniotic fluid was observed and culture showed massive growth of
Aerococcus christensenii, a facultative anaerob species found in the
human vagina, previously only rarely alleged to cause invasive infection.
Additional testing with 16S rRNA gene analysis also identified the presence of
Gemella asaccharolytica, Snethia sanguinegens, Parvimonas
micra and Streptobacillus moniliformis. The patient was
treated with cefuroxime and metronidazole and recovered quickly. The newborn
showed no signs of infection. This case points at the possible role of these
pathogens in female genital tract infections. The case also underlines the
importance of the combination of culture and culture independent diagnostic
approaches to reveal possible polymicrobial natures of selected infections, in
this case chorioamnionitis.
Safety aspects of the bicycle traffic and the needs of cyclists in the City of Zagreb and its surrounding
Authors: Sindik Josko
Published: March 2016

The goals of this study were: to determine the possibility of forecasting for
the preferences of cycling on the basis of all relevant factors Zagreb
cycling (1) and to determine the differences between the participants in all
the relevant factors in Zagreb cycling, by gender, in relation to membership
in the Association "Trad Union of bicyclists", type of cycling and part of
the city where cyclists live (2). Over 3000 members of the Association and
cyclists who are not members of the Association ("average" cyclist) are
tested, using conveniently assembled questionnaire. It turned out that
latent dimensions of the sub-questionnaires well represented themes:
barriers to cycling, the role of the City in bicycle traffic, the purpose of
using bicycle accident during bicycle traffic. People who are more inclined
to participate in city traffic riding, often believe that the City should
significantly improve conditions for cycling, tend to safer driving and more
negative estimate lack of road cycling conditions in Zagreb. Women and
members of the Union of cyclists often feel that the City should improve
conditions for cycling and negatively evaluate the existing conditions of
cycling, more often use the bike for different purposes and had frequent
accidents bicycle. In the northern part of the city, Samobor, Zapresic and
Sesvete, Dugo Selo and Ivanja Reka participants were assessed to have the
most adverse road conditions for cycling, while the wider center of Zagreb
currently has the most favorable conditions for cycling. The results provide
the guidance for improving the safety of the cycling in Zagreb and its
surrounding, for taking constructive social actions at the state level and
on the local-community level, as well as in the broader context of
sustainable development.
The ratio of natural and migration growth component as a determinant of functional urban regions’ development in the Republic of Serbia
Authors: Jeftic Marija
Published: March 2016

Based on the types of population movement model, in the paper is determined
the extent of demographic processes that influenced the formation of
functional urban regions in Serbia. Demographic processes expressed by
immigration-emigration and the natural component of the population
development in the settlements of the Republic of Serbia from 1981 to 2002,
aimed to identify spatial, demographic and functional changes and determine
the degree of spatial differentiation of the Republic of Serbia through
respecting the specificity of its territorial parts. Especially is emphasized
the period from 1991 to 2002 when Republic of Serbia had a demographic
decline in its entirety, with certain differences in the spatial
manifestation but also in the intensity of relationship between natural and
migration component of regional areas of the country. In Vojvodina, the
migration balance had high values with whom he was able to compensate the
consequences of negative natural growth. In the settlements of central Serbia
the low values of migration balance even more emphasized negative natural
increase, which together reflected on the overall demographic decline at the
national level. Functional urban regions are recognized as the instruments of
balanced regional development of Serbia. Generally are given the possible
directions of further functional spatial development that could perspectively
influence the rational organization of the territory of the Republic of
Serbia.
Spatial characteristics of the Podrinje region
Authors: Popovic Dragana
Published: March 2016

Podrinje region, i.e. the area from the both sides of the Drina River,
abounds with extraordinary natural and anthropogenic values, and it
represents the area for development of sustainable tourism. Even though this
area has a long tradition in tourism, this industry is still being developed
spontaneously and without integrated plan. Due to the lack of long tradition
in tourism, it leads to inadequate use of natural and human resources for the
purpose of general economic and tourist development. The mail goal of this
paper is to highlight the significance of spatial planning in the creation of
regional and integrated tourist product, which will contribute to tourism and
economic development of the region, as well as provide long-term benefits on
local, regional, national and international level.
The effect of heat treatments on the synthesis of acrylamide and its quantification by gas chromatography with a nitrogen-phosphorus detetector
Authors: Delevic Veselin , Zejnilovic Refik , Jancic-Stojanovic Biljana , Zrnic-Ciric Milica , Djordjevic Brizita , Stankovic Ivan
Published: March 2016

In this paper, the influence of thermal treatment (cooking, baking and
frying) on the content of acrylamide in potato was followed by gas
chromatography with nitrogen - phosphorus detector (GC-NPD). Sample
preparation was performed in the conventional manner, applying heat treatment
as follows: in boiling water at 110 0C for 30 minutes, by baking in an oven
for 30 minutes at 2200 C, and frying in oil for 15 minutes at 250 0C.
Quantification of acrylamide are preceded: homogenization of the sample,
extraction, and evaporation of the extract. The calibration is performed in
the concentration range 0-10 mg/kg and obtained value for R2 was higher than
0,99. Llimit of detection and limit of quantification were determined and
obtained values were 0,26 mg/kg and 0,41 mg/kg, respectively. Recovery values
were ranged from 102% to 110% and confirmed that metod is accurate. The
proposed GC-NPD method is simple, reliable, and accurate for determination of
the content of acrylamide in food samples. Obtained results show that the
content of acrylamide in potato prepared by heat-cooking were below LOD while
for samples trathed by baking or frying were in range from 0,6 mg/kg to 2,7
mg/kg. By comparing the content of acrylamide in potato we concluded that
heat treatment has a major impact on the synthesis of acrylamide and it would
be desirable to develop a process for the preparation of French fries and
potato chips with low or no acrylamide content with textured attractive for
consummation.
Computer-Assisted Functions for Auditing XBRL-Related Documents
Authors: Boritz J. Efrim , No Won Gyun
Published: March 2016

The increasing global adoption of XBRL and its potential to replace traditional formats for business reporting create a need for quality assurance for XBRL-tagged data. Although prior studies have addressed assurance issues on XBRL-related documents (i.e., instance documents and extension taxonomy) and related audit objectives, they primarily focus on the U.S. and, thus, may not be comprehensive enough for use in other countries. Furthermore, no prior literature discusses what and how computer-assisted audit functions can help auditors while they are performing assurance on XBRL-related documents. The main goal of this paper is to introduce computer-assisted audit functions that can be used by auditors to perform audit tasks to attain identified audit objectives. Based on professional guidelines and prior academic studies, this study introduces a set of audit objectives and related audit tasks that auditors might confront if they are asked to provide assurance on XBRL-related documents. The study then demonstrates a set of related computer-assisted audit functions for conducting the audit tasks and discuss how the identified audit objectives could be achieved using these functions.
Constitutive Relation for Large Deformations of Fiber-Reinforced Rubberlike Materials with Different Response in Tension and Compression
Authors: Li Qian , Dillard David A. , Batra Romesh C.
Published: March 2016

Fiber-reinforced rubberlike materials commonly used in tires undergo large deformations and exhibit different responses in tension and compression along the fiber direction. Assuming that the response of a fiber-reinforced rubberlike material can be modeled as transversely isotropic with the fiber direction as the axis of transverse isotropy, we express the stored energy function in terms of the five invariants of the right Cauchy-Green strain tensor and account for different response in tension and compression along the fiber direction. The constitutive relation accounts for both material and geometric nonlinearities and incorporates effects of the fifth strain invariant, I5. It has been shown by Merodio and Ogden that in shear dominated deformations, I5 makes a significant contribution to the stress-strain curve. We have implemented the proposed constitutive relation in the commercial software, LS-DYNA. The numerical solutions of a few boundary value problems studied here agree with their analytical solutions derived by using Ericksen's inverse approach, in which part of the solution is assumed and unknowns in the presumed solution are found by analyzing the pertinent boundary value problem. However, computed results have not been compared with experimental findings. When test data become available, one can modify the form of the strain energy density and replace the proposed constitutive relation by the new one in LS-DYNA.
Presence of mcr-1-positive Enterobacteriaceae in retail chicken meat but not in humans in the Netherlands since 2009
Authors: Kluytmans–van den Bergh Marjolein F , Huizinga Pepijn , Bonten Marc J , Bos Martine , De Bruyne Katrien , Friedrich Alexander W , Rossen John W , Savelkoul Paul H , Kluytmans Jan A
Published: March 2016

Recently, the plasmid-mediated colistin resistance gene mcr-1 was found in Enterobacteriaceae from humans, pigs and retail meat in China. Several reports have documented global presence of the gene in Enterobacteriaceae from humans, food animals and food since. We screened several well-characterised strain collections of Enterobacteriaceae, obtained from retail chicken meat and hospitalised patients in the Netherlands between 2009 and 2015, for presence of colistin resistance and the mcr-1 gene. A total of 2,471 Enterobacteriaceae isolates, from surveys in retail chicken meat (196 isolates), prevalence surveys in hospitalised patients (1,247 isolates), clinical cultures (813 isolates) and outbreaks in healthcare settings (215 isolates), were analysed. The mcr-1 gene was identified in three (1.5%) of 196 extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates from retail chicken meat samples in 2009 and 2014. Two isolates were obtained from the same batch of meat samples, most likely representing contamination from a common source. No mcr-1-positive isolates were identified among 2,275 human isolates tested. All mcr-1-positive isolates were colistin-resistant (minimum inhibitory concentration (MIC) > 2 mg/L). Our findings indicate that mcr-1-based colistin-resistance currently poses no threat to healthcare in the Netherlands. They indicate however that continued monitoring of colistin resistance and its underlying mechanisms in humans, livestock and food is needed.
The measles outbreak in Bulgaria, 2009–2011: An epidemiological assessment and lessons learnt
Authors: Muscat Mark , Marinova Lili , Mankertz Annette , Gatcheva Nina , Mihneva Zafira , Santibanez Sabine , Kunchev Angel , Filipova Radosveta , Kojouharova Mira
Published: March 2016

Measles re-emerged in a nationwide outbreak in Bulgaria from 2009 to 2011 despite reported high vaccination coverage at national level. This followed an eight-year period since the last indigenous cases of measles were detected. The Bulgarian National Centre of Infectious and Parasitic Diseases collated measles surveillance data for 2009–2011. We analysed data for age group, sex, ethnicity, diagnosis confirmation, vaccination, hospitalisation, disease complications, and death and describe the outbreak control measures taken. The outbreak started in April 2009 following an importation of measles virus and affected 24,364 persons, predominantly Roma. Most cases (73%) were among children < 15 years old. Vaccination status was available for 52% (n = 12,630) of cases. Of children 1–14 years old, 22% (n = 1,769) were unvaccinated and 70% (n = 5,518) had received one dose of a measles-containing vaccine. Twenty-four measles-related deaths were reported. The Roma ethnic group was particularly susceptible to measles. The magnitude of the outbreak resulted primarily from the accumulation of susceptible children over time. This outbreak serves as a reminder that both high vaccination coverage and closing of immunity gaps across all sections of the population are crucial to reach the goal of measles elimination.
High Modernism, Conflict, and the Nature of Change in Canada: A Look at Seeing Like a State
Authors: Loo Tina
Published: March 2016

Seeing Like a State (1998), anthropologist James C. Scott's critique of twentieth-century development and the ideology of “high modernism” that animates it, has shaped the writing of Canadian history, as it has in so many other fields. Environmental historians of Canada, particularly those who study hydroelectric development in the postwar period, have found it especially useful because it links social and environmental change to political power, putting nature at the core of the project of modernization. This article reviews some of that literature to illustrate and critique Scott's key concepts and arguments. Specifically, it takes issue with Scott's contention that high modernist development pitted local knowledge against the expertise of the state's agents. The article also challenges the declensionist narrative offered in the book, which portrays the nature of high modernist change solely in terms of degradation. Finally, it suggests that adopting the very way of seeing that Scott criticizes – an imperial, encompassing, reductive vision – has, and can hold out, the promise for a better kind of development.
Cortical spreading depression occurs during elective neurosurgical procedures
Authors: Carlson Andrew P. , William Shuttleworth C. , Mead Brittany , Burlbaw Brittany , Krasberg Mark , Yonas Howard
Published: March 2016

OBJECTIVE

Cortical spreading depression (CSD) has been observed with relatively high frequency in the period following human brain injury, including traumatic brain injury and ischemic/hemorrhagic stroke. These events are characterized by loss of ionic gradients through massive cellular depolarization, neuronal dysfunction (depression of electrocorticographic [ECoG] activity) and slow spread (2–5 mm/min) across the cortical surface. Previous data obtained in animals have suggested that even in the absence of underlying injury, neurosurgical manipulation can induce CSD and could potentially be a modifiable factor in neurosurgical injury. The authors report their initial experience with direct intraoperative ECoG monitoring for CSD.

METHODS

The authors prospectively enrolled patients undergoing elective craniotomy for supratentorial lesions in cases in which the surgical procedure was expected to last > 2 hours. These patients were monitored for CSD from the time of dural opening through the time of dural closure, using a standard 1 × 6 platinum electrode coupled with an AC or full-spectrum DC amplifier. The data were processed using standard techniques to evaluate for slow potential changes coupled with suppression of high-frequency ECoG propagating across the electrodes. Data were compared with CSD validated in previous intensive care unit (ICU) studies, to evaluate recording conditions most likely to permit CSD detection, and identify likely events during the course of neurosurgical procedures using standard criteria.

RESULTS

Eleven patients underwent ECoG monitoring during elective neurosurgical procedures. During the periods of monitoring, 2 definite CSDs were observed to occur in 1 patient and 8 suspicious events were detected in 4 patients. In other patients, either no events were observed or artifact limited interpretation of the data. The DC-coupled amplifier system represented an improvement in stability of data compared with AC-coupled systems. Compared with more widely used postoperative ICU monitoring, there were additional challenges with artifact from saturation during bipolar cautery as well as additional noise peaks detected.

CONCLUSIONS

CSD can occur during elective neurosurgical procedures even in brain regions distant from the immediate operative site. ECoG monitoring with a DC-coupled full-spectrum amplifier seemed to provide the most stable signal despite significant challenges to the operating room environment. CSD may be responsible for some cases of secondary surgical injury. Though further studies on outcome related to the occurrence of these events is needed, efforts to decrease the occurrence of CSD by modification of anesthetic regimen may represent a novel target for study to increase the safety of neurosurgical procedures.
Bioinformatic analyses reveal a distinct Notch activation induced by STAT3 phosphorylation in the mesenchymal subtype of glioblastoma
Authors: Cheng Wen , Zhang Chuanbao , Ren Xiufang , Jiang Yang , Han Sheng , Liu Yang , Cai Jinquan , Li Mingyang , Wang Kuanyu , Liu Yanwei , Hu Huimin , Li Qingbin , Yang Pei , Bao Zhaoshi , Wu Anhua
Published: March 2016

OBJECTIVE

Glioblastoma (GBM) is the most common and lethal type of malignant glioma. The Cancer Genome Atlas divides the gene expression–based classification of GBM into classical, mesenchymal, neural, and proneural subtypes, which is important for understanding GBM etiology and for designing effective personalized therapy. Signal transducer and activator of transcription 3 (STAT3), a critical transcriptional activator in tumorigenesis, is persistently phosphorylated and associated with an unfavorable prognosis in GBM. Although a set of specific targets has been identified, there have been no systematic analyses of STAT3 signaling based on GBM subtype.

METHODS

This study compared STAT3-associated messenger RNA, protein, and microRNA expression profiles across different subtypes of GBM.

RESULTS

The analyses revealed a prominent role for STAT3 in the mesenchymal but not in other GBM subtypes, which can be reliably used to classify patients with mesenchymal GBM into 2 groups according to phosphorylated STAT3 expression level. Differentially expressed genes suggest an association between Notch and STAT3 signaling in the mesenchymal subtype. Their association was validated in the U87 cell, a malignant glioma cell line annotated as mesenchymal subtype. Specific associated proteins and microRNAs further profile the STAT3 signaling among GBM subtypes.

CONCLUSIONS

These findings suggest a prominent role for STAT3 signaling in mesenchymal GBM and highlight the importance of identifying signaling pathways that contribute to specific cancer subtypes.
Prior Infarcts, Reactivity, and Angiography in Moyamoya Disease (PIRAMD): a scoring system for moyamoya severity based on multimodal hemodynamic imaging
Authors: Ladner Travis R. , Donahue Manus J. , Arteaga Daniel F. , Faraco Carlos C. , Roach Brent A. , Davis L. Taylor , Jordan Lori C. , Froehler Michael T. , Strother Megan K.
Published: March 2016

OBJECTIVE

Quantification of the severity of vasculopathy and its impact on parenchymal hemodynamics is a necessary prerequisite for informing management decisions and evaluating intervention response in patients with moyamoya. The authors performed digital subtraction angiography and noninvasive structural and hemodynamic MRI, and they outline a new classification system for patients with moyamoya that they have named Prior Infarcts, Reactivity, and Angiography in Moyamoya Disease (PIRAMD).

METHODS

Healthy control volunteers (n = 11; age 46 ± 12 years [mean ± SD]) and patients (n = 25; 42 ± 13.5 years) with angiographically confirmed moyamoya provided informed consent and underwent structural (T1-weighted, T2-weighted, FLAIR, MR angiography) and hemodynamic (T2*- and cerebral blood flow–weighted) 3-T MRI. Cerebrovascular reactivity (CVR) in the internal carotid artery territory was assessed using susceptibility-weighted MRI during a hypercapnic stimulus. Only hemispheres without prior revascularization were assessed. Each hemisphere was considered symptomatic if localizing signs were present on neurological examination and/or there was a history of transient ischemic attack with symptoms referable to that hemisphere. The PIRAMD factor weighting versus symptomatology was optimized using binary logistic regression and receiver operating characteristic curve analysis with bootstrapping. The PIRAMD finding was scored from 0 to 10. For each hemisphere, 1 point was assigned for prior infarct, 3 points for reduced CVR, 3 points for a modified Suzuki Score ≥ Grade II, and 3 points for flow impairment in ≥ 2 of 7 predefined vascular territories. Hemispheres were divided into 3 severity grades based on total PIRAMD score, as follows: Grade 1, 0–5 points; Grade 2, 6–9 points; and Grade 3, 10 points.

RESULTS

In 28 of 46 (60.9%) hemispheres the findings met clinical symptomatic criteria. With decreased CVR, the odds ratio of having a symptomatic hemisphere was 13 (95% CI 1.1–22.6, p = 0.002). The area under the curve for individual PIRAMD factors was 0.67–0.72, and for the PIRAMD grade it was 0.845. There were 0/8 (0%), 10/18 (55.6%), and 18/20 (90%) symptomatic PIRAMD Grade 1, 2, and 3 hemispheres, respectively.

CONCLUSIONS

A scoring system for total impairment is proposed that uses noninvasive MRI parameters. This scoring system correlates with symptomatology and may provide a measure of hemodynamic severity in moyamoya, which could be used for guiding management decisions and evaluating intervention response.
Exclusive endoscopic transcanal transpromontorial approach: a new perspective for internal auditory canal vestibular schwannoma treatment
Authors: Marchioni Daniele , Alicandri-Ciufelli Matteo , Rubini Alessia , Masotto Babara , Pavesi Giacomo , Presutti Livio
Published: March 2016

OBJECTIVE

The aim of this study was to describe the first case series in which an exclusive endoscopic transcanal transpromontorial approach (EETTA) was used to treat small vestibular schwannomas (VSs) and meningiomas of the internal auditory canal (IAC).

METHODS

The authors performed a retrospective review of patients who had undergone surgery using an EETTA to the IAC at 2 university tertiary care referral centers during the period from November 2011 to January 2015.

RESULTS

Ten patients underwent surgery via an EETTA for the treatment of VS in the IAC at the University Hospital of Modena or the University Hospital of Verona. The patients had Koos Grade I or II tumors and American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) Class D hearing status preoperatively. Gross-total resection was achieved in all patients. No major complications such as cerebrospinal fluid leakage or hemorrhage were reported. In 7 of 10 (70%) patients, facial nerve function was normal immediately after surgery (Rough Grading System [RGS] Grade I). Two patients presented with a transitory facial palsy immediately after surgery (RGS Grade II–III) but experienced complete recovery during the follow-up period. The mean follow-up was 10 months.

CONCLUSIONS

The EETTA proved to be successful for the removal of VS or meningioma involving the cochlea, fundus, and IAC, with possible lower complication rates and less invasive procedures than those for traditional microscopic approaches. The potential for the extensive and routine use of this approach in lateral and posterior skull base surgery will depend on the development of technology and surgical refinements and on the diffusion of skull base endoscopic skills among the otolaryngological and neurosurgical communities.
Implications of patient-borne costs associated with pediatric neurosurgical care in eastern Africa
Authors: Awori Jonathan , Strahle Jennifer , Okechi Humphrey , Davis Matthew C.
Published: March 2016

OBJECTIVE

Pediatric neurosurgery can be highly cost-effective even in the developing world, but delivery of these services is hampered by resource limitations at the levels of both health care infrastructure and individual patients. Few studies have evaluated costs borne by neurosurgical patients in the developing world and their potential implications for efficient and effective delivery of care in this population.

METHODS

The families of 40 pediatric neurosurgery patients were surveyed in February 2015 at the AIC Kijabe Hospital in Kijabe, Kenya. Costs associated with obtaining inpatient care were assessed.

RESULTS

Patient families were charged an average of US $539.44 for neurosurgical services, representing 132% of their annual income. Indirect expenses (transport, food and lodging, lost wages) constituted US $79.37, representing 14.7% of the overall cost and 19.5% of their annual income.

CONCLUSIONS

Expansion of pediatric neurosurgical services throughout the developing world necessitates increased attention to seemingly insignificant expenses that are absorbed by patients and their families. Even when all direct costs are covered at the institutional or national level, without additional assistance, some patients may be too poor to obtain even “free” neurosurgical care.
Aneurysm growth and de novo aneurysms during aneurysm surveillance
Authors: Serrone Joseph C. , Tackla Ryan D. , Gozal Yair M. , Hanseman Dennis J. , Gogela Steven L. , Vuong Shawn M. , Kosty Jennifer A. , Steiner Calen A. , Krueger Bryan M. , Grossman Aaron W. , Ringer Andrew J.
Published: March 2016

OBJECTIVE

Many low-risk unruptured intracranial aneurysms (UIAs) are followed for growth with surveillance imaging. Growth of UIAs likely increases the risk of rupture. The incidence and risk factors of UIA growth or de novo aneurysm formation require further research. The authors retrospectively identify risk factors and annual risk for UIA growth or de novo aneurysm formation in an aneurysm surveillance protocol.

METHODS

Over an 11.5-year period, the authors recommended surveillance imaging to 192 patients with 234 UIAs. The incidence of UIA growth and de novo aneurysm formation was assessed. With logistic regression, risk factors for UIA growth or de novo aneurysm formation and patient compliance with the surveillance protocol was assessed.

RESULTS

During 621 patient-years of follow-up, the incidence of aneurysm growth or de novo aneurysm formation was 5.0%/patient-year. At the 6-month examination, 5.2% of patients had aneurysm growth and 4.3% of aneurysms had grown. Four de novo aneurysms formed (0.64%/patient-year). Over 793 aneurysm-years of follow-up, the annual risk of aneurysm growth was 3.7%. Only initial aneurysm size predicted aneurysm growth (UIA < 5 mm = 1.6% vs UIA ≥ 5 mm = 8.7%, p = 0.002). Patients with growing UIAs were more likely to also have de novo aneurysms (p = 0.01). Patient compliance with this protocol was 65%, with younger age predictive of better compliance (p = 0.01).

CONCLUSIONS

Observation of low-risk UIAs with surveillance imaging can be implemented safely with good adherence. Aneurysm size is the only predictor of future growth. More frequent (semiannual) surveillance imaging for newly diagnosed UIAs and UIAs ≥ 5 mm is warranted.
Increased risk of delayed cerebral ischemia in subarachnoid hemorrhage patients with additional intracerebral hematoma
Authors: Platz Johannes , Güresir Erdem , Wagner Marlies , Seifert Volker , Konczalla Juergen
Published: March 2016

OBJECTIVE

Delayed cerebral ischemia (DCI) has a major impact on the outcome of patients suffering from aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to assess the influence of an additional intracerebral hematoma (ICH) on the occurrence of DCI.

METHODS

The authors conducted a single-center retrospective analysis of cases of SAH involving patients treated between 2006 and 2011. Patients who died or were transferred to another institution within 10 days after SAH without the occurrence of DCI were excluded from the analysis.

RESULTS

Additional ICH was present in 123 (24.4%) of 504 included patients (66.7% female). ICH was classified as frontal in 72 patients, temporal in 24, and perisylvian in 27. DCI occurred in 183 patients (36.3%). A total of 59 (32.2%) of these 183 patients presented with additional ICH, compared with 64 (19.9%) of the 321 without DCI (p = 0.002). In addition, DCI was detected significantly more frequently in patients with higher World Federation of Neurosurgical Societies (WFNS) grades.

The authors compared the original and modified Fisher Scales with respect to the occurrence of DCI. The modified Fisher Scale (mFS) was superior to the original Fisher Scale (oFS) in predicting DCI. Furthermore, they suggest a new classification based on the mFS, which demonstrates the impact of additional ICH on the occurrence of DCI.

After the different scales were corrected for age, sex, WFNS score, and aneurysm site, the oFS no longer was predictive for the occurrence of DCI, while the new scale demonstrated a superior capacity for prediction as compared with the mFS.

CONCLUSIONS

Additional ICH was associated with an increased risk of DCI in this study. Furthermore, adding the presence or absence of ICH to the mFS improved the identification of patients at the highest risk for the development of DCI. Thus, a simple adjustment of the mFS might help to identify patients at high risk for DCI.
The Preventable Shunt Revision Rate: a potential quality metric for pediatric shunt surgery
Authors: Venable Garrett T. , Rossi Nicholas B. , Morgan Jones G. , Khan Nickalus R. , Smalley Zachary S. , Roberts Mallory L. , Klimo Paul
Published: March 2016

OBJECTIVE

Shunt surgery consumes a large amount of pediatric neurosurgical health care resources. Although many studies have sought to identify risk factors for shunt failure, there is no consensus within the literature on variables that are predictive or protective. In this era of “quality outcome measures,” some authors have proposed various metrics to assess quality outcomes for shunt surgery. In this paper, the Preventable Shunt Revision Rate (PSRR) is proposed as a novel quality metric.

METHODS

An institutional shunt database was queried to identify all shunt surgeries performed from January 1, 2010, to December 31, 2014, at Le Bonheur Children's Hospital. Patients' records were reviewed for 90 days following each “index” shunt surgery to identify those patients who required a return to the operating room. Clinical, demographic, and radiological factors were reviewed for each index operation, and each failure was analyzed for potentially preventable causes.

RESULTS

During the study period, there were 927 de novo or revision shunt operations in 525 patients. A return to the operating room occurred 202 times within 90 days of shunt surgery in 927 index surgeries (21.8%). In 67 cases (33% of failures), the revision surgery was due to potentially preventable causes, defined as inaccurate proximal or distal catheter placement, infection, or inadequately secured or assembled shunt apparatus. Comparing cases in which failure was due to preventable causes and those in which it was due to nonpreventable causes showed that in cases in which failure was due to preventable causes, the patients were significantly younger (median 3.1 vs 6.7 years, p = 0.01) and the failure was more likely to occur within 30 days of the index surgery (80.6% vs 64.4% of cases, p = 0.02). The most common causes of preventable shunt failure were inaccurate proximal catheter placement (33 [49.3%] of 67 cases) and infection (28 [41.8%] of 67 cases). No variables were found to be predictive of preventable shunt failure with multivariate logistic regression.

CONCLUSIONS

With economic and governmental pressures to identify and implement “quality measures” for shunt surgery, pediatric neurosurgeons and hospital administrators must be careful to avoid linking all shunt revisions with “poor” or less-than-optimal quality care. To date, many of the purported risk factors for shunt failure and causes of shunt revision surgery are beyond the influence and control of the surgeon. We propose the PSRR as a specific, meaningful, measurable, and—hopefully—modifiable quality metric for shunt surgery in children.
Utility of a custom screw insertion guide and a full-scale, color-coded 3D plaster model for guiding safe surgical exposure and screw insertion during spine revision surgery
Authors: Otsuki Bungo , Takemoto Mitsuru , Fujibayashi Shunsuke , Kimura Hiroaki , Masamoto Kazutaka , Matsuda Shuichi
Published: March 2016

Several articles have described the use of screw insertion guides during primary spine surgery; however, the use of such a guide during revision surgeries has not been described. The purpose of this study is to describe the utility of a custom screw insertion (CSI) guide assembled using a novel method and a full-scale, color-coded 3D plaster (FCTP) model for safe and accurate revision surgery.

The authors applied the CSI guide and the FCTP model in 3 cases. In the first case, a patient with multiple failed cervical spine surgeries underwent occipitocervicothoracic fusion. After a successful result for this patient, the authors applied the CSI guide in 2 other patients who underwent revision lumbar fusion surgeries to confirm the accuracy and the efficacy of the CSI guides in such cases. The models and guides were fabricated using rapid prototyping technology. The effectiveness of these methods was examined.

The FCTP model was designed using CT data. During model assembly, implants inserted during previous surgery were removed virtually, and for the cervical spine, vertebral arteries were colored red for planning. The CSI guide was designed with 5 or 6 arms to fit the bone surface precisely after removing artifacts. Surgery was performed by referring to the FCTP model. Because the actual structure of the bone surface was almost identical to that of the FCTP model, surgical exposure around the complex bone shape proceeded smoothly. The CSI guides were positioned accurately to aid the successful insertion of a pedicle screw into the C-2 vertebra in the case of cervical revision surgery, and 4 pedicle screws for lumbar vertebrae in the 2 other patients. Postoperative CT scans showed that all screw positions closely matched those predicted during the preoperative planning. In conclusion, the FCTP models and the novel CSI guides were effective for safe and accurate revision surgery of the spine.
Transdiscal mid- and upper thoracic vertebroplasty: first description of 2 exemplary cases
Authors: Filis Andreas K. , Aghayev Kamran , Schaller Bernhard , Luksza Jennifer , Vrionis Frank D.
Published: March 2016

Kyphoplasty and vertebroplasty are established treatment methods to reinforce fractured vertebral bodies. In cases of previous pedicle screw instrumentation, vertebral body cannulation may be challenging. The authors describe, for the first time, an approach through the adjacent inferior vertebra and disc space in the thoracic spine for cement augmentation. A 78-year-old woman underwent posterior fusion with pedicle screws after vertebrectomy and reconstruction with cement and Steinmann pins for a pathological T-7 fracture. Two months later she developed a compression fracture of the vertebral body at the lower part of the construct, and a vertebroplasty was performed. Because a standard transpedicular route was not available, an inferior transdiscal trajectory was used for the cement injection. A 73-year-old man with a history of rheumatoid arthritis underwent cervicothoracic fusion posteriorly for subluxation. He developed pain in the upper thoracic area, and the authors performed a transdiscal vertebroplasty at T-2. The standard transpedicular route was not possible. The vertebral body was satisfactorily filled up with cement. Clinically both patients benefited significantly in terms of back pain and showed an uneventful follow-up of 3 months. Transdiscal vertebroplasty can achieve good results in the mid- and upper thoracic spine when a standard transpedicular trajectory is not possible, and can therefore be a good alternative in select cases.
On a singular heat equation with dynamic boundary conditions
Authors: Schimperna Giulio , Segatti Antonio , Zelik Sergey
Published: March 2016

In this paper we analyze a singular heat equation of the form [Formula: see text]. The singular term [Formula: see text] gives rise to very fast diffusion effects. The equation is settled in a smooth bounded domain [Formula: see text] and complemented with a general dynamic boundary condition of the form [Formula: see text], where [Formula: see text] is the Laplace–Beltrami operator and α and β are non-negative coefficients (in particular, the homogeneous Neumann case given by [Formula: see text] is included). For this problem, we first introduce a suitable weak formulation and prove a related existence result. For more regular initial data, we show that there exists at least one weak solution satisfying instantaneous regularization effects which are uniform with respect to the time variable. In this improved regularity class, uniqueness is also shown to hold.
Law of the iterated logarithm for some Markov operators
Authors: Hille Sander , Horbacz Katarzyna , Szarek Tomasz , Wojewódka Hanna
Published: March 2016

The law of the iterated logarithm for some Markov operators, which converge exponentially to the invariant measure, is established. The operators correspond to iterated function systems which, for example, may be used to generalize the cell cycle model examined by Lasota and Mackey [ J. Math. Biol. 38 (1999), 241–261].
Continuous data assimilation for the three-dimensional Navier–Stokes-α model
Authors: Albanez Débora A.F. , Nussenzveig Lopes Helena J. , Titi Edriss S.
Published: March 2016

Motivated by the presence of a finite number of determining parameters (degrees of freedom) such as modes, nodes and local spatial averages for dissipative dynamical systems, we present here a continuous data assimilation algorithm for three-dimensional viscous hydrodynamic models. However, to validate the convergence of this algorithm our proofs require the existence of uniform global bounds on the gradients of the solutions of the underlying system in terms of certain combinations of the physical parameters (such as kinematic viscosity, the size of the domain and the forcing term). Therefore our proofs cannot be applied to the three-dimensional Navier–Stokes equations; instead we demonstrate the implementation of this algorithm, for instance, in the context of the three-dimensional Navier–Stokes- α equations. This algorithm consists of introducing a nudging process through a general type of approximation interpolation operator (which is constructed from observational measurements) that synchronizes the large spatial scales of the approximate solutions with those of unknown solutions of the Navier–Stokes- α equations corresponding to these measurements. Our main result provides conditions on the finite-dimensional spatial resolution of the collected data, sufficient to guarantee that the approximating solution, which is obtained from this collected data, converges to the unknown reference solution over time. These conditions are given in terms of the physical parameters.
Determination of eight lignans in Schisandra chinensis and Schisandra sphenanthera
Authors: Guangyu Xu , Jiamu Niu , Guangxin Yuan , Yu Bai , Hongyu Li , Yu Sheng , Zitong Li
Published: March 2016

A high performance liquid chromatography method for the determination of eight lignans contents in Schisandra chinensis and Schisandra sphenanthera was developed. The chromatographic column was Agilent ZORBAX 300SB-C18 column (4.6 mm × 250 mm?5 ?m). The mobile phase was methanol-water, a gradient elution was conducted and the detection wavelength was at 230 nm. The results showed that the recovery rate of eight lignans was 92.2-102.9% and RSD was 1.5-4.2%. The established content determination method was simple, sensitive, accurate and stable, and can be used to control the quality of S. chinensis and S. sphenanthera.
Cross-cell DNA methylation annotation and analysis for pan-cancer study
Authors: Tang Binhua , Zhu Weiliang , Wu Changping
Published: March 2016

Pan-cancer study can uncover cell- and tissue-specific genomic loci and regions with underlying biological functions, as one of fundamental procedures toward precision medicine. We utilized the online curated resource of DNA methylation annotation knowledgebase, to implement the cross-cell interrogation of pan-cancer study of breast cancer. The study revealed genome-wide differentially-methylated loci and regions by the reduced representation bisulfite sequencing profiling. The knowledgebase contains three level of curated information across multiple cancer and normal cells from the ENCODE Consortium. The reference base covers all identified differentially-methylation CpG sites and regions of interest, further annotated gene information, together with tumor suppressor gene and methylation level. Lastly, it includes the inferred functional association network and related Gene Ontology analysis results based on all the tumor suppressor genes identified from the differentially-methylated regions of interest. Our knowledgebase and analysis results provide a thorough reference source for biomedical researchers and clinicians. The cross-cell analysis results are deposited at: http://github.com/gladex/DMAK.
Cement plug technique for the management of disc-associated cervical spondylopathy in 52 Dobermann Pinscher dogs
Authors: Pink Jonathan , Gemmill Toby , McKee Malcolm
Published: March 2016

Objectives: To report the radiographic and clinical outcome of an intervertebral bone cement plug technique for the management of disc-associated cervical spondylopathy in Dobermann Pinscher dogs.

Methods: Retrospective study of 52 Dobermann Pinscher dogs.

Results: A variable degree of cement plug subsidence with loss of vertebral distraction was evident in all dogs (n = 40) that were radiographed >6 weeks postoperatively. In no case was there definitive evidence of vertebral body fusion. Eight dogs had a sudden deterioration in neurological status, cervical hyperaesthesia, or both between three days and 12 weeks following surgery that was considered to be implant-associated; six of these dogs were euthanatized. Following surgery, 43/52 dogs were considered to be neurologically normal or to have improved, however, nine of 43 subsequently deteriorated due to adjacent segment disease. At the long-term follow-up, 34 dogs were considered to be neurologically normal or to have improved. Twenty-nine dogs were dead by the end of the study period.

Clinical significance: Intervertebral bone cement plug surgery results in an initial improvement in clinical signs in the majority of Dobermann Pinschers with disc-associated cervical spondylopathy. However, it fails to maintain vertebral distraction or achieve vertebral body fusion, and is associated with acute implant complications, additional cervical disc protrusions or mortality in a significant proportion of cases.

Online Supplementary Material: Please note that online supplementary material for this paper is available at: http://dx.doi.org/10.3415/VCOT-15-09-0160.