bluuebunny/crossref_metadata_2025 huggingface dataset:
The expansion of corporate governance
Authors: Pesqueux Yvon
Published: December 2016

he beginning of this reasoning puts forward the problem of the nature of the company and of its institutional justification, particularly according to the balance “contribution – remuneration” addressed to its stakeholders and to the society, as well as the vocation of corporate governance to focus everything on economic value creation. The political sphere having lost its traditional function of sense making is then confronted with a dilemma: - to answer, according to its doctrinal logic, social problems by developing public services, - to limit this development to face the contesting of public utilities according to the argument of efficiency and, at the same time, favoring the development of companies according to the legitimacy of privatizations. These two aspects represent the dialectical argument of the place of the State in a liberal perspective with an oscillation between a „positive‟ State according to the legitimacy attributed to its intervention and a „negative‟ State, which has to intervene the least possible, while guaranteeing the conditions of development for companies. On front of the lack of a political answer, private initiative tends to develop, in a palliative way, with NGOs for example, NGOs which are ruled according to corporate governance, but adding this new kind of organizations with an institutional vocation to fulfill missions of public utility. Their modes of governance are inherited from corporate governance but according to a humanist and social objective. The research question of this text is to know how far the expansion of governance we experience today is related (or not) with corporate governance and what does it mean. The lines of reasoning of this text are as follows:
- comments about the development of „intermediate‟ organization,
- the discussion of a „broad‟ conception of governance,
- comments on the White Paper on European Governance issued by the European Commission
An analysis of the factors driving the voluntary creation of audit committees: Evidence in the case of Spain
Authors: Pucheta-Martínez María Consuelo , de Fuentes Cristina
Published: December 2016

Following the publication of the Spanish Code of Corporate Good Governance in 1998 (known as the Olivencia Code), some companies voluntarily created audit committees in line with the recommendation that all firms, and especially listed companies, should do so. The aim of this work is to analyse the factors associated with voluntary audit committee formation in companies listed on the Spanish Capital Market through 1999. In particular we analyse factors such as board independence and size, the board chairman/CEO duality, auditor size, agency costs, ownership, economies of scale, institutional investors, the audit report and auditor tenure. We find that voluntary audit committee formation is positively correlated with the proportion of independent directors on the board of directors and economies of scale, while the evidence reveals a non-linear (quadratic) relationship between board size and voluntary audit committee formation. We also formed another sample excluding financial institutions, for which we found that audit committee formation is positively associated with board independence and economies of scale, and negatively associated with the audit report and audit tenure
Moral governance: politicians, ownership, and control
Authors: Di Betta Paolo
Published: December 2016

We investigate upon the influences exerted by politicians on the Board and on ownership structure, as an application of political power to corporations. We characterize moral governance as the joint result of these efforts on managerial turnover and ownership turnover. We comment upon two Italian clinical cases of private, listed firms in which politicians enter the scene when a major event occurs (i.e., reorganization, merger, and acquisition activity). Our model could serve as a guideline and checklist for insiders to interact with politicians. We suggest this could be of interest in countries where there is a common level ground – such as in Europe – but with different cultures on the role of the politician in the business environment. It could be an instrument to detect political intervention in the economy to be also used for cross-country comparisons of business environment and for assessing transparency of companies in developed and developing countries. Recent events from the financial crisis in 2008 have increased the urge to investigate these themes.
The agency dilemma of investment fund management
Authors: Kohlert Daniel , Oehler Andreas , Wendt Stefan
Published: December 2016

The currently observable flight of investors out of investment funds is counterintuitive even in a crisis situation, because they forego the benefits of the collective investment offered by the funds. In order to unveil the reasons for this development we analyze the internal governance structure of German investment funds from a principal-agent perspective. We find that investment companies face severe governance problems because they are agents to at least two groups of principals with potentially conflicting interests. One group of principals consists of the shareholders of the investment company itself, the other group of principals consists of the actual fund investors.
Effects of the largest shareholder stakes on the performance of the Malaysian acquiring firms
Authors: Song Saw-Imm , Ali Ruhani , Pillay Subramaniam
Published: December 2016

This paper examines the relationship between the ownership stakes of the largest shareholders and the post-take-over operating performance and firm values of the acquiring firms. It was found that the operating performance as measured by the control-adjusted cash flow returns rose as the largest ownership stakes increased. However, when the dominant owners obtained a very high level of ownership stakes, the operating performance deteriorated. This shows that at lower level of ownership stakes, ownership concentration aligns the interests between controlling owners and shareholders. In contrast, when the dominant owner had absolute control over the firm, there was a potential of expropriation of minority shareholders by the controlling owners. Nevertheless, we did not find significant relation in the market-based assessment.
The effect of procurement strategies of milling companies on the price of maize
Authors: Rossouw Willem , Young Jacobus
Published: December 2016

Since ultra-poor South Africans spend up to a fifth of their income on maize alone, the demand for this commodity is price-inelastic, i.e. consumers have no choice but to absorb price increases. As such the success of procurement strategies from milling companies will ultimately have a direct impact on the financial well-being of the poor. Even though derivative instruments are available to use as counter against market fluctuations, the price risk management success of groups with a concern on SAFEX suggests that this is not achieved as yet, ultimately to the detriment of consumers. The view exists that markets are efficient and the return offered by the futures exchange cannot consistently be outperformed. This paper argues the exact opposite, since the use of the proposed futures/options strategies result in returns superior to that of the market.
PEACE IN THE MIDST OF VIOLENCE: ANALYZING THE ROLE OF ELITES IN PRESERVING PEACE AND HARMONY IN MANADO
Authors: Abbas Muhammad Rivai
Published: December 2016

The study attempts to look at the existing inter-religious peace and harmony in Manado. The focus is an attempt to compare between Manado and Ambon which are similar in terms of demographic composition, historical background, political and cultural values but at the same time both are different; the former was in conflict, while the latter was an area of peace during the conflict escalation that engulfed some parts of East Indonesia. This study also tries to look at the strategy of Christian and Muslim communities in both cities in dealing with social tensions. In addition, this article specifically tries to explain factors that contribute to the presence of peace in Manado and its absence in Ambon. Subsequently, attention is also paid to the impact and mechanisms used by the elite in maintaining peace in Manado. This study uncovers some interesting findings. First, there are five elements that support the existence of peace in Manado: education, cultural values (local wisdom), economic situations, spiritual understanding, and the role of the elite. Second, inter-religious peace and harmony can exist in Manado, because of the synergy and cooperation of these three levels of leadership. Third, although the theory of Lederach seems to suggest that top-level leaders are the most dominant element of the elite, it is found that the role of grassroots leaders including leaders of congregations (imam, ustadz, clergymen, and priests) is more vital as their more directly involved in the daily activities of society. Fourth, the mechanisms of these elites seem to be various in every stage of leadership.
STUDI ISLAM DALAM KAJIAN HUKUM KELUARGA ISLAM DI INDONESIA
Authors: Sadari Sadari
Published: December 2016

This article offers a study of h}udu>di> (limit) in Islamic family law contained in the Indonesian Compilation of Islamic Law (KHI). The study of h}udu>di is nothing other than the process of desacralization that KHI becomes progressive in line with the development of modernity and in the context of Indonesian-ness. To that end, this article makes two efforts, firstly, by rejecting the idea that gives no attention to limit in one hand, and secondly, by strengthening the thoughts of scholars who offer new ijtihad both in its concept until to methodology. Thought that strengthens it came from Syrian figure, namely Muh}ammad Shah}ru>r, through a plausibility structure. His study of hudud supported Nurcholish Madjid idea about the de-sacralization, so as to perform the coherence between KHI to human rights issues, democracy, nation-state, civil society, and constitutionalism. So this article supports the spirit of de-sacralization - in addition to not abandon its sacralization - initiated by Nurcholish Madjid. The source of this study is KHI, by using the hudud paradigm, that based on a maxim of sabat al-nas wa harakah al-muhtawa, meaning that the text is permanent , but the content moves. So that the rule of law is always rooted in liminality based on the text, which is the pivot of study centered on the text toward the context, not vice versa.
RESOLUSI PENANGANAN GAFATAR PASCA DIBUBARKAN OLEH PEMERINTAH PROVINSI BANGKA BELITUNG
Authors: Rajab Hadarah
Published: December 2016

This study attempts to describe activity GAFATAR in Bangkabelitung after dissolved.The results of research suggest that after the dissolution of GAFATAR, his followers still keep his view that the organization GAFATAR did not teach something subverted from tenets or the rule of law or customary is in this country, and not fund that members of GAFATAR know are the anew after Muhammad saw. They feel this would be a belief where confidence any will be guaranteed in national unity of the republic of Indonesia. On the other hand, after the dissolution of GAFATAR phenomenon, on the surface is looks calmly but still needs to be alert by Karen due to the emergence of GAFATAR the life of his followers be chaotic and misery of then responsibility the leaders GAFATAR there is no.Joy and this phenomenon people who were subjected to experienced depress social in the massif.
Performance assessment of alternate refrigerants for retrofitting R22 based air conditioning system
Authors: Saeed Mian , Qureshi Shafiq , Hashmi Khurram , Khan Muhammad , Danish Syed
Published: December 2016

The performance of zero ozone depletion potential refrigerants is investigated when retrofitted in R22 based air conditioning system. The options evaluated are R407C, R417A, R422D, R427A, and R438A. In order to arrive at most suitable alternative(s) to R22, energy and exergy performance of candidate refrigerants is carried out and compared against that of R22. The COP and exergy efficiencies showed that none of selected refrigerant is as efficient as R22 however their values suggests that each may be considered as potential substitute for retrofitting. Having comparable COP to others but low cooling capacity of R417A makes it less attractive. With comparatively reduced COP, lowest exergy efficiency and highest mass-flow rate, makes R422D the least desirable option. The R407C, R427A, and R438A emerged as most attractive substitutes. The lower discharge temperatures of substitutes will enhance the compressor life. Further, for substitutes there may be a possible change out of expansion valve.
Fractional derivatives of constant and variable orders applied to anomalous relaxation models in heat transfer problems
Authors: Yang Xiao-Jun
Published: December 2016

In this paper, we address a class of the fractional derivatives of constant and variable orders for the first time. Fractional-order relaxation equations of constants and variable orders in the sense of Caputo type are modeled from mathematical view of point. The comparative results of the anomalous relaxation among the various fractional derivatives are also given. They are very efficient in description of the complex phenomenon arising in heat transfer.
Are camera surveys useful for assessing recruitment in white‐tailed deer?
Authors: Chitwood M. Colter , Lashley Marcus A. , Kilgo John C. , Cherry Michael J. , Conner L. Mike , Vukovich Mark , Ray H. Scott , Ruth Charles , Warren Robert J. , DePerno Christopher S. , Moorman Christopher E.
Published: December 2016

Camera surveys commonly are used by managers and hunters to estimate white‐tailed deer Odocoileus virginianus density and demographic rates. Though studies have documented biases and inaccuracies in the camera survey methodology, camera traps remain popular due to ease of use, cost‐effectiveness, and ability to survey large areas. Because recruitment is a key parameter in ungulate population dynamics, there is a growing need to test the effectiveness of camera surveys for assessing fawn recruitment. At Savannah River Site, South Carolina, we used six years of camera‐based recruitment estimates (i.e. fawn:doe ratio) to predict concurrently collected annual radiotag‐based survival estimates. The coefficient of determination (R2) was 0.445, indicating some support for the viability of cameras to reflect recruitment. We added two years of data from Fort Bragg Military Installation, North Carolina, which improved R2 to 0.621 without accounting for site‐specific variability. Also, we evaluated the correlation between year‐to‐year changes in recruitment and survival using the Savannah River Site data; R2 was 0.758, suggesting that camera‐based recruitment could be useful as an indicator of the trend in survival. Because so few researchers concurrently estimate survival and camera‐based recruitment, examining this relationship at larger spatial scales while controlling for numerous confounding variables remains difficult. Future research should test the validity of our results from other areas with varying deer and camera densities, as site (e.g. presence of feral pigs Sus scrofa) and demographic (e.g. fawn age at time of camera survey) parameters may have a large influence on detectability. Until such biases are fully quantified, we urge researchers and managers to use caution when advocating the use of camera‐based recruitment estimates.
Landscape selection by migratory geese: implications for hunting organisation
Authors: Jensen Gitte Høj , Pellissier Loïc , Tombre Ingunn M. , Madsen Jesper
Published: December 2016

Over the last decades, many wild goose populations have increased significantly and are now causing conflicts with socioeconomic and biological interests. To mitigate impacts of rapid population increases, population control by increasing harvest has been attempted. In this study we seek to guide the design of a regional autumn goose hunting organisation in agricultural landscapes by identifying areas suitable for hunting, which have high probability of occurrence of pink‐footed geese Anser brachyrhynchus and/or a short return time by geese to fields subject to hunting. To identify areas suitable for hunting in Nord‐Trøndelag County, mid‐Norway, we used species distributions models (SDMs), a broadly accepted tool in conservation planning for spatial refuge organisation. The prediction was that the highest probability of goose occurrence exists for large fields, away from small roads and near water bodies serving as safe roosting sites. Additionally, return time was predicted to be shortest for large fields near roosting sites and away from big roads. A combined map of goose occurrence and return time showed similar prediction for high goose occurrence and short return time; hence areas most suitable for hunting are large fields, close to roost sites and away from roads. If hunters and landowners are willing to coordinate goose hunting at a landscape level, they can use the prediction maps as guidance, with the likely benefit that they collectively can shoot more geese. Such local and regional organisation can become a powerful tool in the harvest management of geese.
Rearing conditions of greylag geese affect habitat choice throughout life
Authors: Avé Maaike H. , Voslamber Berend , Hallmann Caspar A. , Stahl Julia
Published: December 2016

Anthropogenic changes to the landscape such as fertilization and mowing schemes have been correlated with goslings obtaining a higher weight gain during the first weeks of their life, which in turn increases breeding success and survival at the adult stage. As goose numbers rise, conflicts with farmers become stronger as the birds use agricultural sites for foraging. In this study, habitat choice for individually marked greylag geese from four different rearing conditions, categorized by their temporal application of fertilizer, was documented over a seventeen‐year period. Weekly observations took place on a resident population of wild greylag geese within the Ooijpolder, the Netherlands. The region comprises of areas dedicated to nature restoration as well as agricultural use. In essence, we infer the habitat choice of greylag geese from the frequency of sightings of individually marked geese in different habitat patches, and model habitat choice as a function of rearing conditions, age, and seasonality. Despite a general preference for agricultural grassland, about 40% of the habitat choice was determined by the rearing condition of geese. Interestingly, geese reared in restored meadows, a less favorable rearing habitat, exhibited strong habitat fidelity and preferred to forage in meadows in the spring. Habitat choice was furthermore influenced by age of adult geese and seasonal changes in plant availability. We discuss management implications of our results on habitat choice in an agricultural landscape for increasing resident goose populations. An efficient management measure would be the limitation of goose access to improved grassland during rearing period in the spring.
Considerations on neonatal ungulate capture method: potential for bias in survival estimation and cause‐specific mortality
Authors: Chitwood M. Colter , Lashley Marcus A. , DePerno Christopher S. , Moorman Christopher E.
Published: December 2016

A recent study of Sitka black‐tailed deer Odocoileus hemionus sitkensis demonstrated that opportunistic fawn capture yielded left‐truncated data and ultimately resulted in overestimating fawn survival and spurious ecological model inference compared to neonates captured via vaginal implant transmitters (VITs). Given the ecological and economic value of ungulates worldwide and the importance of neonate survival to understanding population dynamics, the potential biases in survival estimates and causes of mortality caused by left‐truncation must be transparent. Herein, we used a VIT‐based dataset from white‐tailed deer Odocoileus virginianus to examine potential problems with left‐truncated data. We manipulated our original VIT‐based dataset by randomly assigning age‐at‐capture to create three hypothetical opportunistic samples. We used the Kaplan—Meier estimator to quantify fawn survival to 16 weeks of age for the original and hypothetical datasets. Additionally, we compared the relative importance of mortality causes between the datasets. Survival for the original, VIT‐based dataset was 0.121 (SE = 0.043), while hypothetical datasets yielded overestimates (ranging from 0.191 to 0.234). The hypothetical opportunistic samples overestimated coyote predation as a source of mortality, while underestimating starvation. Because management actions rely on accurate estimates of survival and causes of mortality, we recommend that neonatal survival studies consider biases caused by capture method. For robust estimates of survival, VIT‐based samples appear to provide better estimates of survival, as opportunistic samples are biased high. We encourage future work to elucidate the potential for neonate capture technique to affect cause‐specific mortality.
Current nature reserve management in China and effective conservation of threatened pheasant species
Authors: Zhou Chunfa , Zhao Yuzhe , Connelly John W. , Li Junqing , Xu Jiliang
Published: December 2016

Protected areas, such as nature reserves, are essential for effective conservation of threatened species through protection and management of populations and habitats. Habitat evaluation is a key method that has been frequently used to assess the effectiveness of protected areas. Previous research has mainly focused on species conservation related to changes in land cover and habitat fragmentation while few studies have examined changes in microhabitat structure. Using a multi‐scale habitat change analysis (i.e. regional, macro‐ and microhabitat) in a temporal framework, we assessed the effectiveness of current nature reserve management for the habitat protection of the Reeves's pheasant Syrmaticus reevesii, a vulnerable, forest‐dwelling species. We measured land use/land cover changes inside and outside the Dongzhai National Nature Reserve (DNNR), in 2002 and 2013 corresponding to the times at and after the establishment of the DNNR. We also compared differences in habitat fragmentation patterns and microhabitat structure and composition between the two periods. Results show that the forest coverage has slightly increased both inside and outside DNNR, and habitat fragmentation metrics have not changed substantially since the establishment of DNNR. Significant differences were detected in microhabitat structure and composition between 2002 and 2013. After more than 10 years of no disturbance, canopy cover and density of the shrub layer increased, while herbaceous plant height declined. The observed changes reduced resource availability resulting in increased foraging time for pheasants and increased predation rates. This suggests that current nature reserve management systems may have negative impacts on the conservation of the Reeves's pheasant. We propose that the Regulations of Nature Reserves in China should be revised to account for the habitat requirements of different threatened species with varied life history traits.
Quantitative and qualitative 5-aminolevulinic acid–induced protoporphyrin IX fluorescence in skull base meningiomas
Authors: Bekelis Kimon , Valdés Pablo A. , Erkmen Kadir , Leblond Frederic , Kim Anthony , Wilson Brian C. , Harris Brent T. , Paulsen Keith D. , Roberts David W.
Published: December 2016

Object

Complete resection of skull base meningiomas provides patients with the best chance for a cure; however, surgery is frequently difficult given the proximity of lesions to vital structures, such as cranial nerves, major vessels, and venous sinuses. Accurate discrimination between tumor and normal tissue is crucial for optimal tumor resection. Qualitative assessment of protoporphyrin IX (PpIX) fluorescence following the exogenous administration of 5-aminolevulinic acid (ALA) has demonstrated utility in malignant glioma resection but limited use in meningiomas. Here the authors demonstrate the use of ALA-induced PpIX fluorescence guidance in resecting a skull base meningioma and elaborate on the advantages and disadvantages provided by both quantitative and qualitative fluorescence methodologies in skull base meningioma resection.

Methods

A 52-year-old patient with a sphenoid wing WHO Grade I meningioma underwent tumor resection as part of an institutional review board–approved prospective study of fluorescence-guided resection. A surgical microscope modified for fluorescence imaging was used for the qualitative assessment of visible fluorescence, and an intraoperative probe for in situ fluorescence detection was utilized for quantitative measurements of PpIX. The authors assessed the detection capabilities of both the qualitative and quantitative fluorescence approaches.

Results

The patient harboring a sphenoid wing meningioma with intraorbital extension underwent radical resection of the tumor with both visibly and nonvisibly fluorescent regions. The patient underwent a complete resection without any complications. Some areas of the tumor demonstrated visible fluorescence. The quantitative probe detected neoplastic tissue better than the qualitative modified surgical microscope. The intraoperative probe was particularly useful in areas that did not reveal visible fluorescence, and tissue from these areas was confirmed as tumor following histopathological analysis.

Conclusions

Fluorescence-guided resection may be a useful adjunct in the resection of skull base meningiomas. The use of a quantitative intraoperative probe to detect PpIX concentration allows more accurate determination of neoplastic tissue in meningiomas than visible fluorescence and is readily applicable in areas, such as the skull base, where complete resection is critical but difficult because of the vital structures surrounding the pathology.
Molecular genetics of meningiomas: a systematic review of the current literature and potential basis for future treatment paradigms
Authors: Pham Martin H. , Zada Gabriel , Mosich Gina M. , Chen Thomas C. , Giannotta Steven L. , Wang Kai , Mack William J.
Published: December 2016

Although a majority of meningiomas are benign neoplasms, those occurring at the cranial base may be challenging tumors to treat because of extensive tissue invasion, an inability to achieve gross-total microscopic resection, and local tumor recurrence and/or progression. A more comprehensive understanding of the genetic abnormalities associated with meningioma tumorigenesis, growth, and invasion may provide novel targets for grading assessments and individualizing molecular therapies for skull base meningiomas. The authors performed a review of the current literature to identify genes that have been associated with the formation and/or progression of meningiomas. Mutations in the NF2 gene have been most commonly implicated in the formation of the majority of meningiomas. Inactivation of other tumor suppressor genes, including DAL-1 and various tissue inhibitors of matrix metalloproteinases, upregulation of several oncogenes including c-sis and STAT3, and signaling dysregulation of pathways such as the Wnt pathway, have each been found to play important, and perhaps, complementary roles in meningioma development, progression, and recurrence. Identification of these genetic factors using genome-wide association studies and high-throughput genomics may provide data for future individualized treatment strategies.
Surgical nuances for removal of olfactory groove meningiomas using the endoscopic endonasal transcribriform approach
Authors: Liu James K. , Christiano Lana D. , Patel Smruti K. , Tubbs R. Shane , Eloy Jean Anderson
Published: December 2016

Olfactory groove meningiomas represent 10% of intracranial meningiomas and arise in the midline of the anterior cranial fossa along the dura of the cribriform plate and planum sphenoidale. Hyperostosis of the adjacent underlying bone is common, and further extension into ethmoid sinuses and nasal cavity can occur in 15%–25% of cases. Radical tumor resection including the involved dural attachment and underlying hyperostotic bone offers the best chance of a Simpson Grade I resection to minimize recurrence. Incomplete removal of involved hyperostotic bone can result in tumor recurrence at the cribriform plate with extension into the paranasal sinuses. Resection has traditionally been performed using a bifrontal or pterional approach, both of which require some degree of brain retraction or manipulation to expose the tumor.

The endoscopic endonasal transcribriform approach offers the most direct and immediate exposure to the tumor without brain retraction and manipulation of neurovascular structures. An endonasal “keyhole craniectomy” is performed in the ventral skull base directly over the basal dural attachment, extending from the posterior wall of the frontal sinus to the planum sphenoidale and tuberculum sellae in the anteroposterior plane, and from one medial orbit to the other in the coronal plane. Excellent panoramic visualization of the keyhole skull base defect can be obtained with a 30° endoscope after performing a modified Lothrop procedure. Because the dural attachment is adjacent to the paranasal sinuses, early devascularization and total Simpson Grade I removal of the tumor including the dural attachment and underlying hyperostotic bone can be achieved in properly selected patients. This approach is also very suitable for meningiomas that have recurred or extended into the paranasal sinuses. Extracapsular, extraarachnoid dissection of the tumor from the frontal lobes and neurovascular structures can be performed using conventional bimanual microsurgical techniques.

In this report, we review the surgical technique and describe our operative nuances for removal of olfactory groove meningiomas, including recurrent tumors with extension into the nasal cavity, using a purely endoscopic endonasal transcribriform approach. In addition, we discuss the advantages, limitations, patient selection, and complications of this approach. We specifically highlight our technique for multilayer reconstruction of large anterior skull base dural defects using fascia lata and acellular dermal allograft supplemented by bilateral vascularized pedicled nasoseptal flaps. Three new cases of endoscopically resected olfactory groove meningiomas are also presented.
Posterior interhemispheric retrocallosal approach to pineal region and posterior fossa lesions in a pediatric population
Authors: Davidson Laurence , Krieger Mark D. , McComb J. Gordon
Published: December 2016

Object

The purpose of this study was to evaluate the posterior interhemispheric retrocallosal approach (PIRA) for its safety and efficacy in the resection of pineal region and posterior fossa lesions in children.

Methods

Twenty-nine PIRAs were performed in 26 children between March 1997 and March 2009, and these cases were retrospectively reviewed. There were 15 girls and 11 boys in the series. The median age at the time of surgery was 7 years (range 7 months–17 years). Twenty-seven cases were treated for tumor, 1 for loculated hydrocephalus, and 1 for an aneurysm.

Results

Of the 27 cases treated for tumor, there were 20 (74%) gross-total resections, 5 (19%) subtotal resections, and 2 (7%) biopsies. One bridging vein was sacrificed in 6 cases and 2 bridging veins were divided in 1 case, whereas in 3 cases there was sacrifice of a single deep cerebral vein. No patient developed radiographic evidence of venous infarction. Approach-related complications were low, and included 2 cases of transient homonymous hemianopia. There were no surgery-related deaths.

Conclusions

This approach allows for ample access to pineal region and posterior fossa lesions, with low postoperative morbidity.
Multidisciplinary approach to cerebrospinal fluid shunt infection with an appeal for attention to details in assessment and standardization in reporting
Authors: Winston Ken R. , Dolan Susan A.
Published: December 2016

Object

The goal of this study was to evaluate the problems encountered in monitoring CSF shunt infection, including the collection, analysis, and reporting of data. The authors propose a system that would produce more accurate, and hence more meaningful, information on shunt infection than do the methodologies and customs now in common use.

Methods

The authors reviewed and analyzed 19 years of quarterly records of a committee that has addressed CSF shunt infection in an ongoing manner.

Results

There are strong incentives, political and otherwise, to identify low rates of CSF shunt infection. Details of the composition and operation of a multidisciplinary approach to CSF shunt infection are summarized. Many factors affect the occurrence of shunt infection and its accurate assessment and reporting. Easily accessible sources for the identification of cases of shunt infections and for the assessment of an at-risk population often contain discrepancies in significant numbers.

Conclusions

Multidisciplinary oversight of the entire matter of CSF shunt infection enhances the chances for collecting accurate data, identifying causes of infection, and developing effective preventative strategies. Valid data require a mechanism for finding all individuals within the at-risk pool; the accurate identification of patients who had shunt infections; standard, pragmatic, and robust criteria for diagnosis of shunt infection; and multidisciplinary oversight of the entire process.
Pediatric patients with poor neurological status and arteriovenous malformation hemorrhage: an outcome analysis
Authors: Singhal Ash , Adirim Tara , Cochrane Doug , Steinbok Paul
Published: December 2016

Object

In general, patients who present with low Glasgow Coma Scale (GCS) scores and/or fixed and dilated pupils are not expected to do well following arteriovenous malformation (AVM) hemorrhage. However, there is a sense among neurosurgeons that pediatric patients may make a better recovery than adults following such an event. There have been few studies focusing on the outcome of pediatric patients with poor neurological status following AVM hemorrhage. The purpose of this study was to characterize functional outcome in pediatric patients with severe disability after AVM hemorrhage.

Methods

This was a retrospective analysis of clinical presentation and outcome in 15 patients seen at the authors' pediatric hospital presenting with low GCS scores (defined as GCS ≤ 8) following AVM hemorrhage.

Results

Initial GCS scores ranged from 3 to 6, and 11 of 14 patients had fixed pupils on clinical examination (data were not available in 1 patient). Eight of 15 patients suffered primarily a lobar hemorrhage, 3 suffered primarily infratentorial bleeding, 2 suffered primarily hemorrhages of the basal ganglia, and 2 suffered intraventricular hemorrhage. The overall mortality rate was 20% (3 of 15 patients). The clinical outcome of survivors was defined by the Pediatric Cerebral Performance Category (PCPC) and Pediatric Overall Performance Category (POPC) scores at follow-up. One year after AVM hemorrhage, 7 (58%) of the 12 surviving patients showed normal or mild disability (PCPC Score 1 or 2), whereas 5 (42%) of 12 patients had moderate or severe disability (PCPC Score 3 or 4). No patients were in a coma or vegetative state, and 11 (92%) of the 12 patients were functioning independently (POPC Score 1, 2, or 3) 1 year after AVM hemorrhage. All patients were functionally independent by last follow-up, with 8 patients (67%) in the normal or mild disability PCPC category, and 4 in the moderate category (PCPC Score 3). All 12 survivors made a meaningful recovery and went on to live independent lives.

Conclusions

Pediatric patients suffering AVM hemorrhage have a good outcome and are able to function independently, despite a poor neurological state initially.
Complications associated with recombinant human bone morphogenetic protein use in pediatric craniocervical arthrodesis
Authors: Lindley Timothy E. , Dahdaleh Nader S. , Menezes Arnold H. , Abode-Iyamah Kingsley O.
Published: December 2016

Object

Management of pediatric occipitocervical instability remains especially challenging. The off-label use of recombinant human bone morphogenetic protein (rhBMP)-2 for spinal fusion has increased with a well-documented increase in fusion rate in many case series. Unfortunately, recent reports have documented complications associated with rhBMP use in adult spinal fusions. Complications associated with the use of rhBMP in pediatric spinal surgery is less well understood. In this study the authors report on the fusion rate and complications associated with rhBMP in pediatric occipitocervical arthrodesis.

Methods

The authors reviewed the medical records of those patients 18 years old and younger who underwent dorsal occipitocervical fusion from January 2004 to December 2007 at the University of Iowa Hospitals and Clinics. Forty-eight patients were identified who received rhBMP-augmented fusion. The clinical outcome and complications of these fusions were analyzed.

Results

All 48 patients had fusion confirmed on lateral radiographs within 4–14 months with an average fusion time of 6.7 months. There were 6 complications, 5 of which included seroma formation. Two of 5 patients who developed postoperative seroma presented with symptoms suggesting brainstem compression and obstructive hydrocephalus requiring emergency reoperation. One patient developed heterotopic bone formation causing cervicomedullary compression requiring reoperation.

Conclusions

The use of rhBMP to augment autograft in occipitocervical fusion allows for a high rate of successful arthrodesis, but is associated with potentially life-threatening complications in pediatric patients.
Predicting postoperative hydrocephalus in 227 patients with skull base meningioma
Authors: Burkhardt Jan-Karl , Zinn Pascal O. , Graenicher Muriel , Santillan Alejandro , Bozinov Oliver , Kasper Ekkehard M. , Krayenbühl Niklaus
Published: December 2016

Object

Some patients develop communicating hydrocephalus after meningioma surgery, and this can develop into a serious clinical condition. However, this has rarely been addressed in the literature. Therefore, the authors sought to determine predictive patient variables for the occurrence of postoperative hydrocephalus following skull base meningioma surgery.

Methods

For this purpose, the authors retrospectively analyzed all patients who underwent resection of intracranial meningiomas between 1998 and 2009 at the Department of Neurosurgery, University Hospital Zurich, Switzerland. Of 594 patients with meningioma, 227 (38%) had a lesion located at the skull base, and thus were included for analysis. The following patient variables were examined: demographic data (age and sex); tumor number (solitary vs multiple); tumor side and localization within the skull base region (anterior, medial, posterior); infiltration of the cavernous sinus; compression of the optic channel/optic nerve; tumor volume; preoperative embolization (yes/no); duration of surgery; Simpson grade of resection; histopathological features (WHO grade); number of surgeries (single vs multiple); preoperative embolization; duration of hospital stay; tumor recurrence; use of an artificial dural substitute; postoperative infection rate; and clinical outcome (Glasgow Outcome Scale score at discharge and at 3 months, and vital status at last follow-up). Hierarchical clustering, factor analysis, and stepwise regression models revealed a ranking list for the top predictive variables for the occurrence of postoperative hydrocephalus.

Results

A total of 35 patients (5.9%) of the cohort of 594 developed communicating postoperative hydrocephalus, with no patient manifesting obstructive hydrocephalus. Of these 35 patients, 18 had a meningioma located at the skull base (18 [7.9%] of 227), in contrast to 17 patients with meningiomas in other locations (17 [4.6%] of 367). The following patient variables correlated with the occurrence of hydrocephalus, as defined by factor analysis: age, duration of surgery, duration of hospital stay, tumor volume, postoperative infection, and preoperative embolization. A stepwise regression analysis of the latter variables identified 2 variables as significantly predictive: age (p = 0.0012) and duration of surgery (p = 0.0013).

Conclusions

In this study, the incidence of communicating postoperative hydrocephalus was almost twice as high in patients with skull base lesions as in patients with meningiomas in other locations. Patient age, duration of surgery, duration of hospital stay, tumor volume, postoperative infection, and preoperative embolization were associated with the occurrence of hydrocephalus. In the statistical prediction model, patient age and duration of surgery were the most significant predictors of postoperative hydrocephalus after skull base meningioma surgery.
Tiered Objects
Authors: Alessi Fabio , Cardone Felice
Published: December 2016

We investigate the foundations of reasoning over infinite data structures by means of set-theoretical structures arising in the sheaf-theoretic semantics of higher-order intuitionistic logic. Our approach focuses on a natural notion of tiering involving an operation of restriction of elements to levels forming a complete Heyting algebra. We relate these tiered objects to final coalgebras and initial algebras of a wide class of endofunctors of the category of sets, and study their order and convergence properties. As a sample application, we derive a general proof principle for tiered objects.
Bisimulation Cuts For Structuring Markov Transition Systems
Authors: Doberkat Ernst-Erich
Published: December 2016

In Universal Algebra the structure of congruences for algebraic systems is fairly well investigated, and the relationship to the structure of the underlying system proper is well known. We propose a first step into this direction for studying the structure of congruences for stochastic relations. A Galois connection to a certain class of Boolean σ-algebras is exploited, atoms and antiatoms are identified, and it is show that a σ-basis exists. These constructions are applied to the problem of finding bisimulation cuts of a congruence. It cuts the relation through a span of morphisms with a minimum of joint events.
Pairing-Friendly Primes for Abelian Varieties
Authors: Grześkowiak Maciej
Published: December 2016

We present a method of generating primes r ≡ 1 (mod n), q and a Weil q-number π such that r divides Φ n( q) and r divides | A(𝔽 q)|, where A/𝔽 q is an ordinary abelian variety defined over a finite 𝔽 q corresponding to π. Such primes can be used for implementing pairing-based cryptographic systems.
Small Universal Spiking Neural P Systems with Homogenous Neurons and Synapses
Authors: Wu Tingfang , Wang Yanfeng , Jiang Suxia , Shi Xiaolong
Published: December 2016

Spiking neural (SN, for short) P systems are a class of distributed parallel computing models inspired by the way in which neurons communicate with each other by means of electrical impulses. Recently, a new variant of SN P systems, called SN P systems with homogenous neurons and synapses (HRSSN P systems for short) was proposed, where the spiking and forgetting rules are placed on synapses instead of in neurons and each synapse has the same set of spiking and forgetting rules. This variant of SN P systems has already been proved to be Turing universal as both number generating and accepting devices. In this work, we consider the problem of looking for small universal HRSSN P systems. Specifically, a universal HRRSN P system with standard rules and weight at most 5 having 70 neurons is constructed as a device of computing functions; as a number generator, we find a universal system with standard rules and weight at most 5 having 71 neurons.
A parametric optimization code based on local algorithms to design magnetic circuits of Hall effect thrusters
Authors: Rossi Alberto , Messine Frédéric , Henaux Carole
Published: December 2016

Electrical propulsion in space is currently experiencing significant improvements. Among the electrical space propulsion technologies available, Hall effect thrusters work on the generation of plasma inside a cylindrical channel. These thrusters incorporate a magnetic circuit that has to generate a very specific magnetic mapping inside the plasma channel. There are mainly two objectives in the design process of this type of structure. The first objective is to obtain a specific magnetic mapping in the thruster channel with specific magnetic field radial component values. The second one is to obtain a specific magnetic field line inclination. Moreover, for spatial thrusters the minimization of the mass is one of the most important optimization criterion. The aim of this work is to develop a method for resolving the inverse magnetostatic problem, which is applied to obtain an optimized magnetic structure for Hall effect thrusters circuit.
An iterative method for selecting decision variables in analytical optimization problem
Authors: Ounis H. , Roboam X. , Sareni B.
Published: December 2016

In this paper, we present an iterative method to assist the designer in the setting of decision variables in an optimization problem with analytical models. This method is based on the Design Structure Matrix(DSM) which allows a clear representation of interactions between variables. Such a process becomes particularly useful for complex optimal design for which choosing the right decision variables to efficiently solve the problem is not so trivial. This approach is applied to the geometrical model of a High Speed Permanent Magnet Synchronous Machine (HSPMSM).
Multi-objective optimization of the sizing of a hybrid electrical vehicle
Authors: Reinbold Vincent , Gerbaud Laurent , Vinot Emmanuel
Published: December 2016

Hybrid electrical vehicles involve two sources of energy, usually gasoline and electricity. The energy management determines the power sharing between the internal combustion engine and the electrical machine(EM). It is highly dependent on the driving cycle (i.e. the use of the vehicle). In this context, the optimal sizing of the EM is determined by: the driving cycle, the power-train characteristics (i.e. ratios and physical limitations e.g. maximum torque available) and the energy management. The key idea of this work is to involve the driving cycle and the environment of the electrical machine in a global multi-objective optimization process taking into account an optimal energy management and an accurate model of the EM based on magnetic circuit equivalent model.
Optimization and comparison of superconducting generator topologies for a 10 MW wind turbine application
Authors: Liu Dong , Polinder Henk , Abrahamsen Asger B. , Stehouwer Ewoud , Hendriks Ben , Magnusson Niklas
Published: December 2016

A direct-drive superconducting generator (DDSCG) is proposed for 10 MW wind turbines in the INNWIND.EU project. To fit the generator into the ``king-pin'' conceptual nacelle design, the generator structure with inner stationary superconducting (SC) field winding and outer rotating copper armature winding is investigated in the first research phase. Since the cost is an important performance indicator for this application, this paper presents a method to minimize the active material cost of the ``king-pin'' fitted DDSCG. In this method a relatively fast optimization program is developed with 2D non-linear finite element models. By implementing this method, three typical superconducting generator topologies are compared in terms of the active material cost and mass, the synchronous reactance and the phase resistance. The optimization method and the comparison results provide the DDSCG designers with a guideline for selecting a suitable machine topology.