bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress Distribution and Deformation Behavior of Alumina Ceramic after Mini Bullet Dynamic Impact
Authors: Gao Yuan Fei , Si Zhao Xia , Wang Li Juan , Zhang Xue Qin , Liu Shu Ting
Published: April 2018

Alumina ceramics sintered at 1350, 1450 and 1550 °C with different grain sizes were tested under dynamic load using a small-scale compressed air gun with sharpened tungsten carbide bullets impacting at a sub-ballistic velocity of 360 km/h. The deformation behavior and sub-surface cracks were recorded by visual examination. Cr3+fluorescence was used to measure the residual stress distribution on and beneath the impact site. The results show the alumina sintered at 1350 °C with a fine grain size of 1.7 μm and high hardness of 18.3 GPa is good at bulletproof due to the cone cracks can spread the dynamic stress effectively and consume much impact energy.
Synthesis and Reaction Mechanism of Ti3SiC2 by Molten Salt Method from Ti-Si-Fe Alloy
Authors: Zhang Jin Hua , Xiong Si , Ke Chang Ming , Wu Hong Dan , Lei Xin Rong
Published: April 2018

Titanium silicon carbide (Ti3SiC2) were obtained by molten salt synthesis method using the Ti-Si-Fe alloy extracted from high titania blast furnace slag and natural graphite as the raw materials. The phase composition, microscopic structure of the products were characterized by powder X-ray diffraction, scanning electron microscope and transmission electron microscope. The influence of firing temperature and chloride salts species on the phase and morphology of the products were investigated. The results indicated that the synthetic temperature of Ti3SiC2 by molten salt synthesis method was about 100 °C, which was lower than that without molten salts. The “dissolution-precipitation” mechanism governed the overall molten salt synthesis process. The lamellar Ti3(Si,Al)C2 crystal growth obeyed by a two-dimensional ledge growth mechanism.
Improved Photoelectric Properties of ZnO1-x/Graphene Heterostructures
Authors: Wen Jian , Fu Xiu Li , Liu Zhao Xian , Peng Zhi Jian
Published: April 2018

In this work, the photoelectric properties of ZnO1-x/graphene heterostructures were investigated. Such ZnO1-x/graphene heterostructures were constructed from non-stoichiometric zinc oxide (ZnO1-x) film and graphene by first depositing ZnO1-x layer through radio frequency magnetron sputtering onto silicon wafers with SiO2 layer and then transferring graphene via a wet method. It was revealed that such heterostructures could have improved photoelectric properties. Compared with ZnO1-x films, the absorbance of the ZnO1-x/graphene heterostructures in visible and near-infrared region was enhanced; and due to the high conductivity of graphene, the photocurrent was significantly enhanced both in dark and under irradiation of a 700 nm light. By calculating the absolute current gain, it was revealed that the fabricated ZnO1-x/graphene heterostructures would have a higher current gain. Thus, such ZnO1-x/graphene heterostructures would be promisingly applied in visible light to near-infrared detection devices.
Study on the Reaction of NCFO-BZCYYb Catalyst of Methane Steam Reforming
Authors: Li Jia Jia , Wang Xin , Pu Jian , Chi Bo , Li Jian
Published: April 2018

Ni0.5Cu0.5Fe2O4 and BaZr0.1Ce0.7Y0.1Yb0.1O3-d were prepared by an aqueous sol–gel process. The Ni0.5Cu0.5Fe2O4 were modified by various content of BaZr0.1Ce0.7Y0.1Yb0.1O3-d. Their microstructure and phase were observed by SEM and XRD. We studied the effect of BaZr0.1Ce0.7Y0.1Yb0.1O3-d on the methane reforming property of catalyst powder at 650°C, 20ml/min CH4 and x wt. % water vapor (x=3, 10). The composition of exhaust gas was monitored by on-line mass spectrometer. It shown that with the increase of BaZr0.1Ce0.7Y0.1Yb0.1O3-d, the conversion of CH4 decreased. Moreover, the selectivity of CO decreased when water vapor added. Investigated the microstructure and Raman of the power that has catalyzed for 4 hours, It can be found that there were only a few deposited carbon almost cannot detect by Raman.
Preparation of Macroprous C12A7 Mayenite Monoliths via a Sol-Gel Process with Nitrates as Precursors
Authors: Wang Rui , Sun Yu Kun , Jiang Bao Jia Qi , Yang Hui , Guo Xing Zhong
Published: April 2018

Macroporous Ca12Al14O33(C12A7) mayenite monoliths have been successfully prepared via a sol-gel process in the presence of propylene oxide (PO) and poly (ethyleneoxide) (PEO). Gelation of CaO-Al2O3binary system with nitrates salts as additional precursors is accelerated by PO as an acid scavenger, while PEO works as a phase separation inducer to mediate the phase separation of the system. Appropriate PO and PEO amounts allow the formation of monolithic xerogel with interconnected macropores and co-continuous skeletons. The resultant dried gels are amorphous and the single crystalline phase Ca12Al14O33mayenite forms after heat-treatment at 1100 °C in air, while the macrostructure is preserved with a porosity as high as 78% and smoother and denser skeletons.
Micromechanical Behavior and Micromorphology of Single PVA Fiber Pullout
Authors: Chen Bo , Guo Li Ping , Yang Ya Nan , Chen Zheng Kai
Published: April 2018

To evaluate the suitability of domestic polyvinyl alcohol (PVA) fiber for preparing high ductility cementitious composites (HDCC), single PVA fiber pullout tests were conducted. The tests were carried out with four matrices having a water-to-cement ratio of 0.25 or 0.30, and fly ash replacement level 60% or 80%. The micromechanical behavior of single PVA fiber pullout from the matrix was monitored using a fiber tensile testing machine. Micromorphology of the pulled fiber was subsequently investigated using scanning electron microscopy (SEM). The results indicated that the slip-hardening coefficient is greater than zero and that the fiber therefore meets the micromechanical requirements for preparing HDCC. The chemical bonding energy and frictional bond strength were determined to decrease with the increasing fly ash content and/or water-to--cement ratio. SEM images indicate a significant number hydration products attached to the fiber surface, associated with an increase friction force during fiber pullout. After the pullout test, a complete tunnel containing fiber fragments was observed in the matrix, indicative of matrix cutting.
Calculating the Minimum Thickness of Glass Fuse by Zr Kα Line for Phosphorus-Containing Zircon-Refractory Material
Authors: Han Wei , Liu Yu Bing , Ren Jian Xing
Published: April 2018

In this paper, we take Zr Kα line as the analysis object due to the existence of overlapping phenomenon, which the zirconium La line (0.607nm) and phosphorus Ka line (0.615nm), in phosphorus-containing zircon-refractory material. We discovered and calculated the critical thickness of glass fuse by the theoretical calculation method, and we verified the feasibility of the theory. By experiment we found that critical thickness of glass fuse can be reduced by adding additives in flux. Conventional thickness of glass fuse can reaches a critical thickness by adding 20% of calcium oxide (in the form of calcium carbonate was added) in flux. This method could also increase significantly the measurement sensitivity to guarantee good result.
Preparation and Characteristics of ZrO2/ZrW2O8 Composites with Low Thermal Expansion
Authors: Li Jin Ping , Yang Cheng , Li Yu Han , Meng Song He
Published: April 2018

The ZrO2/ZrW2O8 ceramic matrix composites have been prepared by the two different processes: (1) ZrO2 and ZrW2O8 powders were mixed directly as raw material, then compacted by cold isostatic pressing under 200MPa, and finally, the ceramic matrix composites with low thermal expansion can be prepared by use of heat-pressing sintering or atmospheric sintering at temperature 1215oC. (2) ZrO2 (with excess mass) and WO3 powers were mixed as raw material, then compacted by cold isostatic pressing under 200MPa, and finally, the ZrO2/ZrW2O8 ceramic matrix composites can be made by use of heat-pressing sintering or atmospheric sintering at temperature 1215 oC after ZrW2O8 were synthesized by in-situ reaction of ZrO2 and WO3 powders at the same temperature. The microstructure, density, ZrW2O8 decomposition degree and the thermal expansion coefficient were compared among the sintered samples fabricated by the above two different methods, and affected by the different process parameters. The results show that the ceramic matrix composites with low thermal expansion are really composed of ZrO2, ZrW2O8 and WO3, and their relative densities are all more than 95%. Compared with the composites prepared by in-situ reaction, the densities, ZrW2O8 decomposition degree and the thermal expansion coefficient of the composites made by direct mixing are higher, less and smaller, respectively.
Modeling the Impacts of Sea Level Rise on Storm Surge Inundation in Flood-Prone Urban Areas of Hampton Roads, Virginia
Authors: Castrucci Luca , Tahvildari Navid
Published: April 2018

AbstractHampton Roads is a populated area in the United States Mid-Atlantic region that is highly affected by sea level rise (SLR). The transportation infrastructure in the region is increasingly disrupted by storm surge and even minor flooding events. The purpose of this
study is to improve our understanding of SLR impacts on storm surge flooding in the region. We develop a hydrodynamic model to study the vulnerability of several critical flood-prone neighborhoods to storm surge flooding under several SLR projections. The hydrodynamic model is validated for
tide prediction, and its performance in storm surge simulation is validated with the water level data from Hurricane Irene (2011). The developed model is then applied to three urban flooding hotspots located in Norfolk, Chesapeake, and the Isle of Wight. The extent, intensity, and duration
of storm surge inundation under different SLR scenarios are estimated. Furthermore, the difference between the extent of flooding as predicted by the hydrodynamic model and the “bathtub” approach is highlighted.
An Integrated Online Transient Simulation Solution for Subsea Pipeline Operations
Authors: Schoene Clare Butler
Published: April 2018

An integrated online solution for a complex gas gathering network consisting of offshore and onshore pipelines is presented. The system combines single phase and multiphase flow models with a rigorous corrosion calculation tool in an online environment to provide a comprehensive picture of the system state for assistance with operations management, planning, and forecasting. While the pipeline network is operated in the dense phase region, the use of both single phase and multiphase simulation technology makes it possible to have a robust system that is valid during any operational state of the field. The system is designed for use by operators and engineers to assist in daily operations, coordination, and planning. The integrated online solution monitors the pipelines for abnormal operating conditions, such as hydrates, dew point, and leak detection, that are occurring in real time and uses forecasting technology to determine if any abnormal conditions may occur in the near future.

As part of the online condition monitoring a rigorous corrosion calculation that includes the effects of sour gas, acid gas, water chemistry, and multiphase flow effects is incorporated into the system. The online models provide the data on gas composition and pipeline operating conditions required by the corrosion tool so that in situ corrosion rates can be calculated as profiles along the entire length of the pipeline. Detailed, on demand corrosion analysis can be performed at user specified points if further analysis is required.

The integrated online solution architecture is designed for high uptime and redundancy. The design includes consideration for databases, communications, virtual machines, simulation results handling, network redundancy, and maintainability. The architecture takes advantage of virtual machine technology and network redundancy to provide a high level of system performance while ensuring robustness to hardware failures.

The system was deployed in late 2016 and has operational ever since. Value has been realized through use of the tool to: evaluate pig tracking using the multiphase model to provide operations with an estimated pig arrival time; predict real time dew point to assist with managing rich gas and lean gas mixtures within the network; perform pack and draft modeling to allow pipeline operators to predict the run-down time of gas delivery; assess the risk of hydrates, dew point, or off spec gas and take preventive actions. Cost saving have been realized by the ability to optimize multimillion dollar inline inspection frequencies using the corrosion monitoring module and the overall operating conditions of the pipelines.
Deletion of Inflammasome Components Is Not Sufficient To Prevent Fatal Inflammation in Models of Familial Hemophagocytic Lymphohistiocytosis
Authors: Fauteux-Daniel Sébastien , Viel Sébastien , Besson Laurie , Zhang Jiang , Marotel Marie , Mathieu Anne-Laure , Pescarmona Rémi , Charrier Emily , Henry Thomas , Belot Alexandre , Walzer Thierry
Published: April 2018

Hemophagocytic lymphohistiocytosis (HLH) is a severe inflammatory condition that occurs in patients with genetic defects of cytotoxicity (familial HLH [FHL]) or secondary to other immunological disorders such as juvenile idiopathic arthritis. HLH is characterized by elevated levels of serum IL-18 and other cytokines. Moreover, a novel clinical entity has been recently identified in which constitutive NLRC4 inflammasome activation leads to severe HLH. Altogether, these clinical observations suggest that inflammasome activation is a central event in the development of all HLH forms and that inflammasome blockade could alleviate inflammation in FHL patients. To formally address this question, we invalidated genes encoding for Caspase-1 or the inflammasome adapter ASC in perforin-deficient mice that were subsequently infected with lymphocytic or mouse choriomeningitis virus as models of FHL. These deletions nearly abrogated IL-18 production occurring during HLH in all models. However, they did not reduce serum IFN-γ levels at the peak of the inflammatory reaction nor did they modulate inflammatory parameters at mid and late stages or fatal outcome. These data show that inflammasome blockade is not sufficient to prevent cytokine storm and lethality in mouse models of FHL and suggest that different pathophysiological mechanisms underlie HLH in genetic defects of cytotoxicity and genetic forms of inflammasome activation.
Intellectual disability rights and inclusive citizenship in South Africa: What can a scoping review tell us?
Authors: Capri Charlotte , Abrahams Lameze , McKenzie Judith , Coetzee Ockert , Mkabile Siyabulela , Saptouw Manuel , Hooper Andrew , Smith Peter , Adnams Colleen , Swartz Leslie
Published: April 2018

Background: Intellectual disability (ID) is the most prevalent disability in the world. People with intellectual disability (PWID) frequently experience extreme violations of numerous human rights. Despite greater prevalence in South Africa than in high-income countries, most ID research currently comes from the Global North. This leaves us with few contextually sensitive studies to draw from to advance inclusive citizenship.Objectives: Our scoping review aims to investigate pertinent ID rights issues in South Africa, synthesise quantitative and qualitative studies, and provide a synopsis of available evidence on which to base future work. We aim to clarify key concepts, address gaps in the literature and identify opportunities for further research.Method: We followed strict eligibility criteria. Medical subject heading terms were entered into seven databases. Seven reviewers worked independently, two per paper. Quantitative and qualitative data extraction forms were designed. We followed Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and registered a protocol. An inductive approach enabled a thematic analysis of selected studies.Results: By following PRISMA guidelines, 82 studies were assessed for eligibility of which 59 were included. Ten sub-themes were integrated into four main themes: the right not to be discriminated against, the right to psychological and bodily integrity, the right to accommodating services and challenges to rights implementation.Conclusion: People with intellectual disability face compound difficulties when trying to assert their constitutionally entitled rights. This ongoing project requires serious commitment and action. Statutory obligations to nurture every South African’s human rights naturally extend to PWID and their supporters who forge ahead in a disabling environment.
Current concepts in intradiscal percutaneous minimally invasive procedures for chronic low back pain
Authors: Gelalis Ioannis , Gkiatas Ioannis , Spiliotis Antonios , Papadopoulos Dimitrios , Pakos Emilios , Vekris Marios , Korompilias Anastasios
Published: April 2018

Study Design: A systemic review of thermal annular procedures (TAPs) and percutaneous disk decompression procedures (PDDPs) for the treatment of discogenic chronic low back pain (CLBP) was conducted. Objective: The objective of this review is to evaluate and to compare the effectiveness of TAPs and PDDPs in treating discogenic CLBP and to assess the frequency of complications associated with those procedures. Materials and Methods: English-language journal articles were identified through computerized searches of the PubMed database and bibliographies of identified articles and review papers. Articles were selected for inclusion if percutaneous minimally invasive procedures were the treatment options for patients with CLBP and if follow-up outcome data included evaluations of back pain severity, functional improvement, and/or incidence of complications. For this review, 27 studies were included. Results: Intradiscal electrothermal therapy (IDET) procedure in properly selected patients may eliminate or delay the need for surgical intervention for an extended period, whereas few adverse effects have been reported. In contrast to IDET, there is far less literature on the effectiveness of radiofrequency annuloplasty and intradiscal biacuplasty procedures. Nucleoplasty is a potentially effective treatment option for patients with contained disc herniation, while the procedure is well tolerated. Increased success rates have been found for percutaneous laser disc decompression and automated percutaneous lumbar discectomy in strictly selected patients. Conclusions: These procedures can be effective and may obviate the need for surgery completely. Further prospective randomized sham-controlled trials with higher quality of evidence are necessary to confirm the efficacy of these procedures.
Coil embolisation of post traumatic giant supraclinoid pseudoaneurysm presenting as carotid cavernous fistula
Authors: Narayan Dange , Jayprakash Singh , Arjun Dhar , Achal Gupta
Published: April 2018

This report documents the occurrence, diagnosis and treatment of a 29 year-old male patient who presented with progressive swelling of the left eye with associated progressive loss of vision, three months after sustaining a closed head injury in a road traffic accident. Magnetic resonance imaging (MRI) showed a large, ill-defined lesion in the left supraclinoid and paraclinoid region with variable contrast enhancement. A four vessel Digital Subtraction Angiography (DSA) showed a large, supra-clinoid pseudoaneurysm which had ruptured inferiorly into the roof of cavernous sinus, forming direct carotid cavernous fistula (CCF) which lead to dilatation of the superior ophthalmic vein and subsequent peri-orbital oedema and chemosis of conjunctiva. Complete obliteration of the indirect CCF was achieved by coiling of the aneurysm alone. During follow up, patient reported a significant improvement in vision and follow up DSA after one year shows no recurrence with this technique.
Epidemiology of spinal injury in North East India: A retrospective study
Authors: Birua Gyani , Munda Vishnu , Murmu Nagendra
Published: April 2018

Aim: To find out the epidemiology of spinal injury in North East India. Material and Methods: This study is a retrospective hospital-based analysis of spine injury patients admitted to Central Referral Hospital, Sikkim Manipal University from July 2013 to June 2017July 2013 to June 2017. Results: During the study period 57 patients with spinal injury were admitted and treated. Out of the 57 patients, 46 (81%) were male and 11 (19%) were female. The most common mode of injury was fall from height (59.64%) followed by RTA (35.08%). Most common affected age group in this study was 20-39 years followed by 50-59 years age group. Cervical spine injury was the most common (52.63%) followed by thoracic (19.29%) spine. Most common injury found was fracture dislocation of C5-C6 level. Most common associated injury is head trauma (10.52 %) followed by chest injury and 82.45% cases had no associated trauma. Average period of hospital stay was 22.83 days with maximum period of stay was 111 days. During treatment period one patient died due to respiratory complications. Conclusion: The epidemiology of spinal injuries in Sikkim & North Eastern India is different from rest of the India and other developing countries. In present study most common cause of spine injury was fall from height followed by motor vehicle accidents. RTA was the main cause in younger age group and fall from height was more common in elderly group.
Endoscopic approach to subcortical (Lobar) hemorrhage
Authors: Suyama Daisuke , Kumar Brajesh , Watanabe Saiko , Tanaka Riki , Yamada Yasuhiro , Kawase Tsukasa , Kato Yoko
Published: April 2018

Objective: To highlight the basic points of brain endoscopic procedure for Subcortical (Lobar) Hemorrhage to achieve repeatability and reproducibility in the results among the new brain endoscopic surgeons. Method: Sharing the experience of 10 years as an endoscopic surgeon to bring out the basic insight into the method, challenges, points which need special attention during the surgery and discussion of recent advancements in the endoscopic equipment for safe surgery. Conclusion: Procedure of endoscopic evacuation of brain hematoma is simple with learning curve. In the beginning new endoscopic surgeons should operate in the presence of experience surgeon. They should follow standard technique to achieve the good surgical outcome and uniformity in the result every time they perform the surgery.
Armored brain associated with secondary craniostenosis development at 7-year following ventriculoperitoneal shunt surgery during infancy: Extremely unusual association and review
Authors: Satyarthee Guru , Lalwani Sanjeev
Published: April 2018

Calcification is uncommon in chronic subdural hematoma and popularly known as calcified chronic subdural hematoma (CSSDH), and about hundred cases are reported in the form of isolated cases report. The calcified inner membrane of chronic subdural hematoma gets adherent to underlying cerebral cortex preventing re-expansion of the brain and producing mass effect. Calcification can develop in chronic subdural hematoma of traumatic origin or postmeningitic effusion or extremely rarely after shunt surgery. CCSDH is also known as armored brain or Matrioska head and those related to cerebrospinal fluid diversion ventriculoperitoneal (VP) shunt surgery, constitute one of the rare complications of shunt, and development is attributed to overdrainage of shunt. Authors report a unique case with bilateral calcified chronic subdural hematoma in an 8-year-old boy, who had VP shunt surgery for obstructive hydrocephalus at the age of 1 year of life, presented with feature of nonlocalized raised intracranial pressure; a diagnosis of suspected VP shunt malfunction was also considered; however, cranial computed tomography scan on current admission revealed the presence of bilateral calcified chronic subdural hematoma with secondary craniostenosis and managed successfully with burr-hole craniostomy and drainage of CCSDH. In a detailed PubMed and Medline search, authors could not get any publication regarding CSSDH associated with secondary craniostenosis developing following VP shunt surgery in infancy. The current case represents the first case in the Western literature developing secondary craniostenosis-associated CCSDH following shunt surgery in infancy, requiring surgical management. The clinical features, neuroimaging, and management of such rare case along with pertinent literature are reviewed briefly.
Microvascular decompression in patients aged 30 years or younger
Authors: Karki Prasanna , Yamagami Masayuki , Takasaki Koji , Bohara Manoj , Hosoyama Hiroshi , Hanada Tomoko , Yamasaki Fumiyuki , Hanaya Ryosuke , Arita Kazunori
Published: April 2018

Objective: The aim of this study was to identify the etiology of hemifacial spasm (HFS) and trigeminal neuralgia (TN) in patients aged 30 years or younger and to examine the efficacy of microvascular decompression (MVD). Patients and Methods: Between 1996 and 2012, 228 HFS and 190 TN patients underwent MVD at Atsuchi Neurosurgical Hospital. Of these, 7 patients were 30 years of age or younger at the time of treatment (HFS: n = 6, TN: n = 1). Assessments were based on their medical history and on magnetic resonance imaging, magnetic resonance angiography, surgical, and follow-up findings. Results: The age of the 6 HFS patients ranged from 23 to 30 years (mean 27.8 ± 1.8 [standard deviation] years) at the time of surgery; the earliest symptom onset was in an 11-year-old boy. We noted vascular variations in 5 patients, a duplicate posterior inferior cerebellar artery in 2 patients, a short basilar artery in 1 patient, and an aberrant arterial course in 2 patients. At the latest follow-up, 1–69 months after MVD, 5 of the HFS patients were asymptomatic and the 6th had mild residual symptoms. A 23-year-old TN female underwent straightening of the trigeminal nerve by separation of a thickened arachnoid membrane from the nerve and dislocation of a small branch of the superior cerebellar artery from the distal end of the root exit zone. While she continued to experience occasional facial pain 48 months after the operation, she required no medication because surgery yielded significant pain amelioration. Conclusion: Although the pathogenesis of early-onset HFS and TN remains unclear, our findings suggest that vascular variations may be related to the etiology of vascular compression symptoms in patients with HFS or TN. MVD was useful for the treatment of neurovascular compression symptoms in young patients.
Endoscopic endonasal resection of the odontoid process in a patient with chronic injury of the C1 transverse ligament
Authors: Grin Andrey , Lvov Ivan , Godkov Ivan , Sytnik Aleksey , Kordonskiy Anton , Smirnov Vladimir
Published: April 2018

Atlas dislocation after transverse ligament injury is one of the most rare types of trauma to the upper cervical level. If magnetic resonance imaging of the craniovertebral junction reveals the Kassam line passing through the cervix of the odontoid process, a transnasal approach can be used for surgical treatment. Here, we present a case in which an endoscopic endonasal approach was used to treat chronic traumatic transligamentous atlas dislocation. A 26-year-old male underwent two-stage surgical treatment; during the first stage, posterior decompression and fixation were performed under halo immobilization. In the second stage, a transnasal endoscopic approach to the odontoid process was used. A transnasal approach permitted complete decompression of the medulla oblongata and facilitated early extubation of the patient without any postoperative complications such as respiratory or pharyngopalatine deficiency. The patient was discharged in good condition 9 days after the surgery.
Controlled trial to compare therapeutic efficacy of endoscopic third ventriculostomy plus choroid plexus cauterization with ventriculoperitoneal shunt in infants with obstructive hydrocephalus
Authors: Navaei Amir , Hanaei Sara , Habibi Zohreh , Jouibari Morteza , Heidari Vahid , Naderi Soheil , Nejat Farideh
Published: April 2018

Context: Ventriculoperitoneal (VP) shunt and endoscopic third ventriculostomy (ETV) are the established surgical treatments for obstructive hydrocephalus (HCP). Powerful evidence regarding the best therapeutic approach for infants with obstructive HCP is lacked. Aims: Comparison of the therapeutic efficacy of VP shunt and ETV/choroid plexus cauterization (CPC) in infants with obstructive HCP. Settings and Design: This was a randomized, active control, unblind, single-center, clinical trial. Methods: Infants with obstructive HCP were randomly allocated to each intervention group (ETV/CPC or VP shunt). They were monitored for at least 6 months for any sign of raised intracranial pressure (rICP). The recurrence of rICP signs requiring surgical intervention was considered as intervention failure. Statistical Analysis: The association between intervention group and outcome was tested with Chi-square test, and P = 0.05 or less was considered statistically significant. Results: Of the total fifty patients entering the study, 49 were included in the final analysis, 27 of them were in VP shunt and 22 in ETV/CPC group. Seventeen patients (34%) were female and 33 (66%) were male with mean age of 3.74 ± 3.1 months (range = 10 days – 11 months). Thirty-nine (79.6%) were under 6 months of age and the remaining were 6 months or older. The overall success rate in 36-month follow-up was 88.5% and 68.2% for VP shunt and ETV/CPC, respectively, with the difference being not statistically significant. Conclusion: The current study determined no inferiority of ETV/CPC compared to VP shunt, and therefore, it may become an efficient treatment for obstructive HCP in infants.
Extradural hematoma following decompressive craniectomy for acute subdural hematoma: Two case reports illustrating different mechanisms
Authors: Pillai Mahesh , Kariyattil Rajeev , Govindaraju Venkatesh , Kochummen Koshy , Kumar Rajinder
Published: April 2018

The occurrence of extradural hematoma (EDH) after decompressive craniectomy (DC) for traumatic brain injury is uncommon. We report two cases, one developing ipsilateral EDH and another developing contralateral simultaneous EDH and subdural hematoma after DC. The strategies to anticipate the occurrence of such concurrent hematomas (CH) are highlighted. We propose a subclassification of CH into “immediate” and “delayed,” based on their difference in clinical presentation, image findings, pathogenesis, and surgical management.
A comprehensive review of skull base osteomyelitis: Diagnostic and therapeutic challenges among various presentations
Authors: Khan Muhammad , Quadri Syed , Kazmi Abdulmuqueeth , Kwatra Vishal , Ramachandran Anirudh , Gustin Aaron , Farooqui Mudassir , Suriya Sajid , Zafar Atif
Published: April 2018

Skull base osteomyelitis (SBO) is a complex and fatal clinical entity that is often misdiagnosed for malignancy. SBO is commonly a direct complication of otogenic, sinogenic, odontogenic, and rhinogenic infections and can present as central, atypical, or pediatric clival SBO. This review describes the clinical profi le, investigational approach, and management techniques for these variants. A comprehensive literature review was performed in PubMed, MEDLINE, Research Gate, EMBASE, Wiley Online Library, and various Neurosurgical and Neurology journals with the keywords including: SBO, central or atypical SBO, fungal osteomyelitis, malignant otitis externa, temporal bone osteomyelitis, and clival osteomyelitis. Each manuscript's reference list was reviewed for potentially relevant articles. The search yielded a total of 153 articles. It was found that with early and aggressive culture guided long-term intravenous broad-spectrum antibiotic therapy decreases post-infection complications. In cases of widespread soft tissue involvement, an early aggressive surgical removal of infectious sequestra with preferentially Hyperbaric Oxygen (HBO) therapy is associated with better prognosis of disease, less neurologic sequelae and mortality rate. Complete resolution of the SBO cases may take several months. Since early treatment can improve mortality rates, it is paramount that the reporting radiologists and treating clinicians are aware of the cardinal diagnostic signs to improve clinical outcomes of the disease. It will decrease delayed diagnosis and under treatment of the condition. However, due to rarity of the condition, complete prognostic factors have not fully been analyzed and discussed in the literature.
Cochlear implant device failure in the postoperative period: An institutional analysis
Authors: Bhadania Simple , Vishwakarma Rajesh , Keshri Amit
Published: April 2018

Introduction: As the cochlear implant (CI) surgeries are on rise, there is a compelling need to understand its long-term complications and revision surgery protocols. Our experience in the management of CI devices failure is shared in this paper. Aim: To review the experience in patients who underwent CI device manipulation/explanation in terms of failure rate, etiology, surgical considerations, and preoperative and postoperative auditory and speech outcome. Study Design: This was a retrospective study. Materials and Methods: A retrospective study of 250 patients (201 children and 49 adults) with normal cochlea at a tertiary care center from June 2004 to June 2014 was done. All cases were implanted multichannel devices via Veria technique of CI surgery. Preoperative assessment, surgical considerations, and postoperative auditory and speech outcomes were analyzed. Preoperative and postoperative auditory/speech outcomes were analyzed using Category of Auditory Perception (CAP) and Speech Intelligibility Rating (SIR) scores. Results: Reimplantation rate was 4%. The causes of revision CI surgery were hard device failure (n = 3), surgical site infection (n = 3), magnet displacement (n = 2), and electrode extrusion (n = 2). In one patient, recurrent cutaneous infection on the implanted site ultimately resulted in reimplantation in the opposite ear after multiple surgical interventions on the same side. The preoperative and postoperative CAP and SIR scores showed improvement in the postoperative period with P < 0.05 as compared with the paired t- test. Conclusions: Preoperative counseling for device failure should always be emphasized. The success rate is high in revision surgery with good performance in the postoperative audiological outcome. There is a compelling need for an agreed international definition of CI failure and the adoption of uniform reporting protocols.
Bilateral orbital cavernous hemangioma
Authors: Hentati Aslam , Matar Nidhal , Dridi Hadhemi , Bouali Soufien , Jemel Hafedh
Published: April 2018

Cavernous hemangioma of the orbit (CHO) is a benign slow-growing lesion of intracanal space. Bilateral orbital cavernous hemangiomas are extremely rare, so that only a few cases have been reported in scientific literature. A 54-year-old patient presented a 1-year history of impaired visual acuity of the left eye. Physical examination showed a left axial propotosis. Orbital magnetic resonance imaging showed a 28 mm diameter intraconal space mass of the left orbit, as well as another 11 mm diameter lesion in the right eye, in the superomedial extraconal space. A superior wall left orbitotomy was performed with a total removal of the tumor. The right lesion was respected. Histopathological examination confirmed the diagnosis of CHO. Bilateral cavernous hemangiomas are extremely rare. Orbital imaging guides the diagnosis. The neurosurgeons prefer craniotomy while ophthalmologists favor various modifications of orbitotomies.
Cubic Twin Prime Polynomials are Counted by a Modular Form
Authors: Bary-Soroker Lior , Stix Jakob
Published: April 2018

We present the geometry behind counting twin prime polynomials in $\mathbb{F}_{q}[T]$ in general. We compute cohomology and explicitly count points by means of a twisted Lefschetz trace formula applied to these parametrizing varieties for cubic twin prime polynomials. The elliptic curve $X^{3}=Y(Y-1)$ occurs in the geometry, and thus counting cubic twin prime polynomials involves the associated modular form. In theory, this approach can be extended to higher degree twin primes, but the computations become harder.

The formula we get in degree 3 is compatible with the Hardy–Littlewood heuristic on average, agrees with the prediction for $q\equiv 2$ (mod 3), but shows anomalies for $q\equiv 1$ (mod 3).
Bridging the digital divide: measuring digital literacy
Authors: Chetty Krish , Qigui Liu , Gcora Nozibele , Josie Jaya , Wenwei Li , Fang Chen
Published: April 2018

To promote digital transformation, equal emphasis needs to be placed on digital skills development as to infrastructure development. Integral to investment in digital skills development is the subsequent management and evaluation of digital training programmes. This paper assesses mechanisms to ensure digital training programmes are adequately managed using a standardized data collection framework to measure an internationally accepted digital literacy index. Such an index requires an agile definition of digital literacy, responsive to the fluid nature of the digital economy. The paper also explores the extent to which a G20 advisory body may inform a nationally representative data collection strategy within the context of a data collection process that is cognizant of the evolving demands of businesses and users alike.
Bridging the digital divide in the G20: skills for the new age
Authors: Chetty Krish , Aneja Urvashi , Mishra Vidisha , Gcora Nozibele , Josie Jaya
Published: April 2018

The digital divide in general, and between women and men in particular, is a manifestation of exclusion, poverty and inequality, and is likely to continue because of the effects of unemployment, poorly functioning digital skilling programmes and socio-cultural norms in some economies, and further depriving women equal access to digital services. Digital skills provide the poor a catalyst to break out of the cycle of poverty and empower themselves. This paper proposes a three-pronged digital skills strategy that will be required for developing countries to break out of the digital divide trap: (1) Monitor the evolving set of digital skills required for employment, (2) incorporate a holistic digital skills development strategy into national education programmes, and (3) contextualize skilling programs within prevailing socio-cultural norms that will shape the uptake and impact of digital skilling programs.
Sensitivity of stomatal conductance to soil moisture: implications for tropospheric ozone
Authors: Anav Alessandro , Proietti Chiara , Menut Laurent , Carnicelli Stefano , De Marco Alessandra , Paoletti Elena
Published: April 2018

Abstract. Soil moisture and water stress play a pivotal role in regulating stomatal
behaviour of plants; however, in the last decade, the role of water
availability has often been neglected in atmospheric chemistry modelling
studies as well as in integrated risk assessments, despite the fact that
plants remove a large amount of atmospheric compounds from the lower
troposphere through stomata. The main aim of this study is to evaluate, within the chemistry transport
model CHIMERE, the effect of soil water limitation on stomatal conductance
and assess the resulting changes in atmospheric chemistry testing various
hypotheses of water uptake by plants in the rooting zone. Results highlight how dry deposition significantly declines when soil
moisture is used to regulate the stomatal opening, mainly in the semi-arid
environments: in particular, over Europe the amount of ozone removed by dry
deposition in one year without considering any soil water limitation to
stomatal conductance is about 8.5 TgO3, while using a dynamic layer
that ensures that plants maximize the water uptake from soil, we found a
reduction of about 10 % in the amount of ozone removed by dry deposition
(∼ 7.7 TgO3). Although dry deposition occurs from the top of canopy to
ground level, it affects the concentration of gases remaining in the lower
atmosphere, with a significant impact on ozone concentration (up to 4 ppb)
extending from the surface to the upper troposphere (up to 650 hPa). Our results shed light on the importance of improving the parameterizations
of processes occurring at plant level (i.e. from the soil to the canopy) as
they have significant implications for concentration of gases in the lower
troposphere and resulting risk assessments for vegetation or human health.
Global hydro-climatic biomes identified via multi-task learning
Authors: Papagiannopoulou Christina , Miralles Diego G. , Demuzere Matthias , Verhoest Niko E. C. , Waegeman Willem
Published: April 2018

Abstract. The most widely-used global land cover and climate classifications are based on vegetation characteristics and/or climatic conditions derived from observational data. However, these classification schemes do not directly stem from the interaction between the local climate and the biotic environment. In this work, we model the dynamic interplay between vegetation and local climate in order to delineate ecoregions that share a coherent response to hydro-climate variability. Our novel framework is based on a multi-task learning approach that discovers the spatial relationships among different locations by learning a low-dimensional representation of predictive structures. This low-dimensional representation is combined with a clustering algorithm that yields a classification of biomes with coherent behaviour. Experimental results using global observation-based data sets indicate that, without the need to prescribe any land cover information, our method is able to identify regions of coherent climate-vegetation interactions that agree well with the expectations derived from traditional global land cover maps. The resulting global hydro-climatic biomes can be used to analyse the anomalous behaviour of specific ecosystems in response to climate extremes and to benchmark climate-vegetation interactions in Earth system models.
Faulting patterns determining groundwater flow paths in
the Lower Yarmouk Gorge
Authors: Inbar Nimrod , Rosenthal Eliahu , Magri Fabien , Alraggad Marwan , Möller Peter , Flexer Akiva , Guttman Joseph , Siebert Christian
Published: April 2018

Abstract. Recent studies investigating groundwater parameters e.g. heads, chemical composition and heat transfer, argued that groundwater flow paths in the Lower Yarmouk Gorge area are controlled by geological features such as faults or dikes (Goretzki et al., 2016; Magri et al., 2016; Roded et al., 2013; Siebert et al., 2014). However, the nature of such features as well as their exact locations were previously unknown. In the present manuscript, we propose a new fault pattern in the Lower Yarmouk Gorge area constructed by compiling and revising geological and geophysical data from the study area including borehole information, geological maps cross-sections and seismic data from southern Golan Heights and northern Ajloun Mountain. The presented pattern is composed of strike-slip and thrust faults, which are associated with the Dead Sea Transform system and with the Kinnarot pull-apart basin. Compressional and tensional structures developed in different places forming a series of fault-blocks probably causing a non-uniform spatial hydraulic connection between them. This study provides a coarse fault block model and improved structural constraints that serve as fundamental input for future hydrogeological modelling.
Assessing the hydrologic response to wildfires in mountainous regions
Authors: Havel Aaron , Tasdighi Ali , Arabi Mazdak
Published: April 2018

Abstract. This study aims to understand the hydrologic responses to wildfires in
mountainous regions at various spatial scales. The Soil and Water Assessment
Tool (SWAT) was used to evaluate the hydrologic responses of the upper Cache la
Poudre Watershed in Colorado to the 2012 High Park and Hewlett wildfire
events. A baseline SWAT model was established to simulate the hydrology of
the study area between the years 2000 and 2014. A procedure involving land
use and curve number updating was implemented to assess the effects of
wildfires. Application of the proposed procedure provides the ability to
simulate the hydrologic response to wildfires seamlessly through mimicking
the dynamic of the changes due to wildfires. The wildfire effects on curve
numbers were determined comparing the probability distribution of curve
numbers after calibrating the model for pre- and post-wildfire conditions.
Daily calibration and testing of the model produced “very good” results.
No-wildfire and wildfire scenarios were created and compared to quantify
changes in average annual total runoff volume, water budgets, and full
streamflow statistics at different spatial scales. At the watershed scale,
wildfire conditions showed little impact on the hydrologic responses.
However, a runoff increase up to 75 % was observed between the scenarios in
sub-watersheds with high burn intensity. Generally, higher surface runoff and
decreased subsurface flow were observed under post-wildfire conditions.
Flow duration curves developed for burned sub-watersheds using full
streamflow statistics showed that less frequent streamflows become greater in
magnitude. A linear regression model was developed to assess the relationship
between percent burned area and runoff increase in Cache la Poudre Watershed.
A strong (R2 > 0.8) and significant (p < 0.001) positive
correlation was determined between runoff increase and percentage of burned
area upstream. This study showed that the effects of wildfires on hydrology
of a watershed are scale-dependent. Also, using full streamflow statistics
through application of flow duration curves revealed that the wildfires had a
higher effect on peak flows, which may increase the risk of flash floods in
post-wildfire conditions.
Geomagnetic field declination: from decadal to centennial scales
Authors: Dobrica Venera , Demetrescu Crisan , Mandea Mioara
Published: April 2018

Abstract. Declination annual mean time series longer than 1 century provided by 24 geomagnetic observatories worldwide, together with 5 Western European reconstructed declination series over the last 4 centuries, have been analyzed in terms of the frequency constituents of the secular variation at inter-decadal and sub-centennial timescales of 20–35 and 70–90 years. Observatory and reconstructed time series have been processed by several types of filtering, namely Hodrick–Prescott, running averages, and Butterworth. The Hodrick–Prescott filtering allows us to separate a quasi-oscillation at a decadal timescale, which is assumed to be related to external variations and called the 11-year constituent, from a long-term trend. The latter has been decomposed into two other oscillations called inter-decadal and sub-centennial constituents by applying a Butterworth filtering with cutoffs at 30 and 73 years, respectively. The analysis shows that the generally accepted geomagnetic jerks occur around extrema in the time derivative of the trend and coincide with extrema in the time derivative of the 11-year constituent. The sub-centennial constituent is traced back to 1600 in the five 400-year-long time series and seems to be a major constituent of the secular variation, geomagnetic jerks included.