bluuebunny/crossref_metadata_2025 huggingface dataset:
Unilateral versus bilateral iliac screws for spinopelvic fixation: are two screws better than one?
Authors: Saigal Rajiv , Lau Darryl , Wadhwa Rishi , Le Hai , Khashan Morsi , Berven Sigurd , Chou Dean , Mummaneni Praveen V.
Published: May 2014

Object

Long-segment spinal instrumentation ending at the sacrum places substantial biomechanical stress on sacral screws. Iliac (pelvic) screws relieve some of this stress by supplementing the caudal fixation. It remains an open question whether there is any clinically significant difference in sacropelvic fixation with bilateral versus unilateral iliac screws. The primary purpose of this study was to compare clinical and radiographic complications in the use of bilateral versus unilateral iliac screw fixation.

Methods

The authors retrospectively reviewed 102 consecutive spinal fixation cases that extended to the pelvis at a single institution (University of California, San Francisco) in the period from 2005 to 2012 performed by the senior authors. Charts were reviewed for the following complications: reoperation, L5–S1 pseudarthrosis, sacral insufficiency fracture, hardware prominence, iliac screw loosening, and infection. The t-test, Pearson chi-square test, and Fisher exact test were used to determine statistical significance.

Results

The mean follow-up was 31 months. Thirty cases were excluded: 12 for inadequate follow-up, 15 for lack of L5–S1 interbody fusion, and 3 for preoperative osteomyelitis. The mean age among the 72 remaining cases was 62 years (range 39–79 years). Forty-six patients underwent unilateral and 26 bilateral iliac screw fixation. Forty-one percent (n = 19) of the unilateral cases and 50% (n = 13) of the bilateral cases were treated with reoperation (p = 0.48). In addition, 13% (n = 6) of the unilateral and 19% (n = 5) of the bilateral cases developed L5–S1 pseudarthrosis (p = 0.51). There were no sacral insufficiency fractures. Thirteen percent (n = 6) of the unilateral and 7.7% (n = 2) of the bilateral cases developed postoperative infection (p = 0.70).

Conclusions

In a retrospective single-institution study, single versus dual pelvic screws led to comparable rates of reoperation, iliac screw removal, postoperative infection, pseudarthrosis, and sacral insufficiency fractures. For spinopelvic fixation, placing bilateral (vs unilateral) pelvic screws produced no added clinical benefit in most cases.
Brain shift during bur hole–based procedures using interventional MRI
Authors: Ivan Michael E. , Yarlagadda Jay , Saxena Akriti P. , Martin Alastair J. , Starr Philip A. , Sootsman W. Keith , Larson Paul S.
Published: May 2014

Object

Brain shift during minimally invasive, bur hole–based procedures such as deep brain stimulation (DBS) electrode implantation and stereotactic brain biopsy is not well characterized or understood. We examine shift in various regions of the brain during a novel paradigm of DBS electrode implantation using interventional imaging throughout the procedure with high-field interventional MRI.

Methods

Serial MR images were obtained and analyzed using a 1.5-T magnet prior to, during, and after the placement of DBS electrodes via frontal bur holes in 44 procedures. Three-dimensional coordinates in MR space of unique superficial and deep brain structures were recorded, and the magnitude, direction, and rate of shift were calculated. Measurements were recorded to the nearest 0.1 mm.

Results

Shift ranged from 0.0 to 10.1 mm throughout all structures in the brain. The greatest shift was seen in the frontal lobe, followed by the temporal and occipital lobes. Shift was also observed in deep structures such as the anterior and posterior commissures and basal ganglia; shift in the pallidum and subthalamic region ipsilateral to the bur hole averaged 0.6 mm, with 9% of patients having over 2 mm of shift in deep brain structures. Small amounts of shift were observed during all procedures; however, the initial degree of shift and its direction were unpredictable.

Conclusions

Brain shift is continual and unpredictable and can render traditional stereotactic targeting based on preoperative imaging inaccurate even in deep brain structures such as those used for DBS.
Arachnoid membranes in the posterior half of the incisural space: an inverted Liliequist membrane–like arachnoid complex
Authors: Zhang Xi-an , Qi Song-tao , Fan Jun , Huang Guang-long , Peng Jun-xiang
Published: May 2014

Object

The aim of this study was to describe the similarity of configuration between the arachnoid complex in the posterior half of the incisural space and the Liliequist membrane.

Methods

Microsurgical dissection and anatomical observation were performed in 20 formalin-fixed adult cadaver heads. The origin, distribution, and configuration of the arachnoid membranes and their relationships with the vascular structures in the posterior half of the incisural space were examined.

Results

The posterior perimesencephalic membrane and the cerebellar precentral membrane have a common origin at the tentorial edge and form an arachnoid complex strikingly resembling an inverted Liliequist membrane. Asymmetry between sides is not uncommon. If the cerebellar precentral membrane is hypoplastic on one side or both, the well-developed quadrigeminal membrane plays a prominent part in partitioning the subarachnoid space in the posterior half of the incisural space.

Conclusions

The arachnoid complex in the posterior half of the incisural space can be regarded as an inverted Liliequist membrane. This concept can help neurosurgeons to gain better understanding of the surgical anatomy at the level of the tentorial incisura.
Thoracolumbar spinal vascular malformation as a rare cause of isolated intraventricular hemorrhage
Authors: Marlin Evan S. , Entwistle John J. , Arnold Michael A. , Pierson Christopher R. , Governale Lance S.
Published: May 2014

Spinal vascular malformations are rare vascular lesions that most frequently present with back pain, radiculopathy, and/or myelopathy. Neurological decline is typically secondary to progressive radiculopathy, myelopathy, venous thrombosis, and stroke. Few case reports have described thoracolumbar spinal vascular malformations that present with both subarachnoid and intraventricular hemorrhage. This is the first reported case of a thoracolumbar spinal vascular malformation presenting with isolated intraventricular hemorrhage on initial imaging followed by acute and fatal rehemorrhage.
Spindle cell hemangioendothelioma of the sacrum
Authors: Winter Andrea , Siu Alan , Jamshidi Aria , Malawer Martin , Sherman Jonathan H.
Published: May 2014

Spindle cell hemangioendothelioma is a rare benign vascular tumor that is not known to involve the sacrum. The authors describe the case of a 31-year-old woman presenting with low-back and radicular pain without weakness or bowel or bladder dysfunction. Admission CT and MRI studies revealed a large S1–3 lytic sacral lesion. The patient initially underwent a nondiagnostic percutaneous biopsy. She subsequently underwent an open biopsy, during which the lesion was found to be highly vascular. Histological investigation revealed a vasoformative lesion consistent with spindle cell hemangioendothelioma. Preoperative embolization followed by resection via intralesional currettage resulted in resolution of symptoms up to 9 months postintervention. Despite the authors' recommendation, the patient became pregnant at that time and requested no additional follow-up imaging. The authors present the first reported case of a spindle cell hemangioendothelioma of the sacrum and review the current literature.
Twist-drill craniostomy with hollow screws for evacuation of chronic subdural hematoma
Authors: Chari Aswin , Kolias Angelos G. , Santarius Thomas , Bond Simon , Hutchinson Peter J.
Published: May 2014

Object

The incidence of chronic subdural hematoma (CSDH) is expected to increase substantially over the next 25 years. Continuing refinement of techniques for surgical evacuation is essential for optimizing patient outcomes. A novel technique involving a hollow screw, which is threaded through a twist-drill hole in the cranium and then connected to a closed drainage system, has been increasing in popularity. The aim of this systematic review is to collate and analyze the published experience with this novel technique and to evaluate its efficacy in comparison with the other surgical treatment methods.

Methods

This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and has been registered with the PROSPERO International Prospective Register of Systematic Reviews (registration number CRD42013003544). MEDLINE, Web of Knowledge, EMBASE, and the Cochrane Database of Systematic Reviews were searched for published series involving more than 10 patients treated with these new techniques.

Results

Nine eligible studies were found (6 case series and 3 case-control studies) comprising 796 patients treated with these new techniques. Pooled analysis showed a “success rate” of 77.6% (95% CI 74.6%–80.4%), recurrence rate of 22.4%, and in-hospital mortality of 1.4%.

Conclusions

This systematic review adds further evidence to the pool of data assessing the safety and efficacy of the use of this novel, minimally invasive technique for the treatment for CSDH. Overall, twist-drill craniostomy with hollow screws appears to be safe and effective. Class I evidence is necessary to optimize the surgical management of patients with CSDH.
AtomPy: An Open Atomic Data Curation Environment for Astrophysical Applications
Authors: Mendoza Claudio , Boswell Josiah , Ajoku David , Bautista Manuel
Published: May 2014

We present a cloud-computing environment, referred to as AtomPy, based on Google-Drive Sheets and Pandas (Python Data Analysis Library) DataFrames to promote community-driven curation of atomic data for astrophysical applications, a stage beyond database development. The atomic model for each ionic species is contained in a multi-sheet workbook, tabulating representative sets of energy levels, A-values and electron impact effective collision strengths from different sources. The relevant issues that AtomPy intends to address are: (i) data quality by allowing open access to both data producers and users; (ii) comparisons of different datasets to facilitate accuracy assessments; (iii) downloading to local data structures (i.e., Pandas DataFrames) for further manipulation and analysis by prospective users; and (iv) data preservation by avoiding the discard of outdated sets. Data processing workﬂows are implemented by means of IPython Notebooks, and collaborative software developments are encouraged and managed within the GitHub social network. The facilities of AtomPy are illustrated with the critical assessment of the transition probabilities for ions in the hydrogen and helium isoelectronic sequences with atomic number Z ≤ 10.
Computational Information Geometry in Statistics: Theory and Practice
Authors: Critchley Frank , Marriott Paul
Published: May 2014

A broad view of the nature and potential of computational information geometry in statistics is offered. This new area suitably extends the manifold-based approach of classical information geometry to a simplicial setting, in order to obtain an operational universal model space. Additional underlying theory and illustrative real examples are presented. In the inﬁnite-dimensional case, challenges inherent in this ambitious overall agenda are highlighted and promising new methodologies indicated.
Statistical Diagnosis of the Best Weibull Methods for Wind Power Assessment for Agricultural Applications
Authors: Azad Abul , Rasul Mohammad , Yusaf Talal
Published: May 2014

The best Weibull distribution methods for the assessment of wind energy potential at different altitudes in desired locations are statistically diagnosed in this study. Seven different methods, namely graphical method (GM), method of moments (MOM), standard deviation method (STDM), maximum likelihood method (MLM), power density method (PDM), modified maximum likelihood method (MMLM) and equivalent energy method (EEM) were used to estimate the Weibull parameters and six statistical tools, namely relative percentage of error, root mean square error (RMSE), mean percentage of error, mean absolute percentage of error, chi-square error and analysis of variance were used to precisely rank the methods. The statistical fittings of the measured and calculated wind speed data are assessed for justifying the performance of the methods. The capacity factor and total energy generated by a small model wind turbine is calculated by numerical integration using Trapezoidal sums and Simpson’s rules. The results show that MOM and MLM are the most efficient methods for determining the value of k and c to fit Weibull distribution curves.
Strategizing Carbon-Neutral Mines: A Case for Pilot Projects
Authors: Power Ian , McCutcheon Jenine , Harrison Anna , Wilson Sasha , Dipple Gregory , Kelly Simone , Southam Colette , Southam Gordon
Published: May 2014

Ultramafic and mafic mine tailings are a valuable feedstock for carbon mineralization that should be used to offset carbon emissions generated by the mining industry. Although passive carbonation is occurring at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond and Mount Keith nickel mines, there remains untapped potential for sequestering CO2 within these mine wastes. There is the potential to accelerate carbonation to create economically viable, large-scale CO2 fixation technologies that can operate at near-surface temperature and atmospheric pressure. We review several relevant acceleration strategies including: bioleaching of magnesium silicates; increasing the supply of CO2 via heterotrophic oxidation of waste organics; and biologically induced carbonate precipitation, as well as enhancing passive carbonation through tailings management practices and use of CO2 point sources. Scenarios for pilot scale projects are proposed with the aim of moving towards carbon-neutral mines. A financial incentive is necessary to encourage the development of these strategies. We recommend the use of a dynamic real options pricing approach, instead of traditional discounted cash-flow approaches, because it reflects the inherent value in managerial flexibility to adapt and capitalize on favorable future opportunities in the highly volatile carbon market.
The COSMO-SkyMed Constellation Monitors the Costa Concordia Wreck
Authors: Raspini Federico , Moretti Sandro , Fumagalli Alfio , Rucci Alessio , Novali Fabrizio , Ferretti Alessandro , Prati Claudio , Casagli Nicola
Published: May 2014

On 13 January 2012, the Italian vessel, Costa Concordia, wrecked offshore Giglio Island, along the coast of Tuscany (Italy). The ship partially sunk, lying on the starboard side on a 22° steep rocky seabed, making the stability conditions of the ship critically in danger of sliding, shifting and settling. The tilted position of the ship created also pernicious conditions for the divers involved in the search and rescue operations. It became immediately clear that a continuous monitoring of the position and movements of the ship was of paramount importance to guarantee the security of the people working around and within the wreck. Starting from January 19, the Italian constellation of synthetic aperture radar (SAR) satellites, COSMO-SkyMed (CSK), was tasked to acquire high resolution images of the wreck. Thanks to CSK’s short response and revisiting time and its capability to acquire high resolution images in Spotlight mode, satellite data were integrated within the real time, ground-based monitoring system implemented to provide the civil protection authorities with a regular update on the ship stability. Exploitation of both the phase (satellite radar interferometry, InSAR) and amplitude (speckle tracking) information from CSK images, taken along the acquisition orbit, Enhanced Spotlight (ES)-29, revealed a general movement of the translation of the vessel, consistent with sliding toward the east of the hull on the seabed. A total displacement, with respect to the coastline, of 1666 mm and 345 mm of the bow and stern, respectively, was recorded, over the time period of 19 January–23 March 2012.
A Three-Dimensional Index for Characterizing Crop Water Stress
Authors: Torrion Jessica , Maas Stephan , Guo Wenxuan , Bordovsky James , Cranmer Andy
Published: May 2014

The application of remotely sensed estimates of canopy minus air temperature (Tc-Ta) for detecting crop water stress can be limited in semi-arid regions, because of the lack of full ground cover (GC) at water-critical crop stages. Thus, soil background may restrict water stress interpretation by thermal remote sensing. For partial GC, the combination of plant canopy temperature and surrounding soil temperature in an image pixel is expressed as surface temperature (Ts). Soil brightness (SB) for an image scene varies with surface soil moisture. This study evaluates SB, GC and Ts-Ta and determines a fusion approach to assess crop water stress. The study was conducted (2007 and 2008) on a commercial scale, center pivot irrigated research site in the Texas High Plains. High-resolution aircraft-based imagery (red, near-infrared and thermal) was acquired on clear days. The GC and SB were derived using the Perpendicular Vegetation Index approach. The Ts-Ta was derived using an array of ground Ts sensors, thermal imagery and weather station air temperature. The Ts-Ta, GC and SB were fused using the hue, saturation, intensity method, respectively. Results showed that this method can be used to assess water stress in reference to the differential irrigation plots and corresponding yield without the use of additional energy balance calculation for water stress in partial GC conditions.
A Decade Long, Multi-Scale Map Comparison of Fire Regime Parameters Derived from Three Publically Available Satellite-Based Fire Products: A Case Study in the Central African Republic
Authors: Freeborn Patrick , Cochrane Mark , Wooster Martin
Published: May 2014

Although it is assumed that satellite-derived descriptions of fire activity will differ depending on the dataset selected for analysis, as of yet, the effects of failed and false detections at the pixel level and on an instantaneous basis have not been propagated through space and time to determine their cumulative impact on the characterization of individual fire regime parameters. Here we perform the first ever decade long, multi-scale map comparison of fire chronologies and fire seasonality derived from three publicly available satellite-based fire products: the MODIS active fire product (MCD14ML), the ATSR nighttime World Fire Atlas (WFA), and the MODIS burned area product (MCD45A1). Results indicate that: (i) the agreement between fire chronologies derived from two dissimilar satellite products improves as fire pixels are aggregated into coarser grid cells, but diminishes as the number of years included in the time series increases; and (ii) all three datasets provide distinctly different portraits of the onset, peak, and duration of the fire season regardless of the map resolution. Differences in regional, long-term fire regime parameters derived from the three datasets are attributed to the unique capability of each sensor and detection algorithm to recognize geographical gradients, seasonal oscillations, decadal trends, and interannual variability in active fire characteristics and burned area patterns. Since different satellite sensors and detection algorithm strategies are sensitive to different types of fires, we demonstrate that disagreements in fire regime maps derived from dissimilar satellite-based fire products can be used as an advantage to highlight spatial and temporal transitions in landscape fire activity. Given access to multiple, publically available datasets, we caution against describing fire regimes using a single satellite-based active fire or burned area product.
Allenylphosphine oxides as simple scaffolds for phosphinoylindoles and phosphinoylisocoumarins
Authors: Gangadhararao G , Kotikalapudi Ramesh , Nagarjuna Reddy M , Swamy K C Kumara
Published: May 2014

A range of phosphinoylindoles was prepared in one-pot from functionalized propargyl alcohols and a suitable P(III) precursor via a base-mediated reaction. The reaction proceeds via the intermediacy of allenylphosphine oxides. Similarly, phosphinoylisocoumarins were prepared from allenylphosphine oxides in a trifluoroacetic acid-mediated reaction; the latter also acts as a solvent. Interestingly, in the presence of wet trifluoroacetic acid, in addition to phosphinoylisocoumarins, phosphorus-free isocoumarins were also obtained. Key products were characterized by single crystal X-ray crystallography.
The Effect of Intravenous Golimumab on Health-related Quality of Life in Rheumatoid Arthritis: 24-week Results of the Phase III GO-FURTHER Trial
Authors: Bingham Clifton O. , Weinblatt Michael , Han Chenglong , Gathany Timothy A. , Kim Lilianne , Lo Kim Hung , Baker Dan , Mendelsohn Alan , Westhovens Rene
Published: May 2014

Objective.

To evaluate the effects of intravenous (IV) golimumab 2 mg/kg + methotrexate (MTX) on patient-reported measures of health-related quality of life (HRQOL) in patients with active rheumatoid arthritis (RA) despite prior MTX therapy.

Methods.

In this randomized, multicenter, double-blind, placebo-controlled, phase III trial, adults with RA were randomly assigned to receive IV placebo (n = 197) or golimumab 2 mg/kg (n = 395) infusions at Week 0, Week 4, and every 8 weeks thereafter. All patients continued stable oral MTX (15–25 mg/wk). HRQOL assessments included Health Assessment Questionnaire-Disability Index (HAQ-DI; physical function), Medical Outcomes Study Short Form-36 questionnaire physical/mental component summary (SF-36 PCS/MCS) scores, EQ-5D assessment of current health state, Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue) questionnaire, and disease effect on productivity [10-cm visual analog scale (VAS)].

Results.

Mean HAQ-DI improvements from baseline were significantly greater with golimumab + MTX than placebo + MTX at Week 14 and Week 24 (p < 0.001). Significantly greater improvements in all 8 individual SF-36 subscores and both the SF-36 PCS and MCS scores (p < 0.001) also accompanied golimumab + MTX therapy. Improved EQ-5D and EQ-5D VAS (p < 0.001) and FACIT-Fatigue (p < 0.001) scores were also observed for golimumab + MTX-treated patients at Week 12, Week 16, and Week 24, and greater proportions of golimumab + MTX-treated patients had clinically meaningful improvements in these measures. Greater reductions in disease effect on productivity were observed with golimumab + MTX versus placebo + MTX at Week 24 (p < 0.001). Improvements in physical function, HRQOL, fatigue, and productivity significantly correlated with disease activity improvement.

Conclusion.

In active RA, IV golimumab + MTX significantly improved physical function, HRQOL, fatigue, and productivity using multiple measurement tools; all correlated with improvements in disease activity (NCT00973479, EudraCT 2008-006064-11).
Interoperability of EHR Systems Based on Semantic Representation and Transformation Models
Authors: Martínez-Costa Catalina , Menárguez-Tortosa Marcos , Fernández-Breis Jesualdo Tomás
Published: May 2014

The semantic interoperability of electronic healthcare record systems is a major issue given that it would increase the quality of healthcare and patient safety. In this chapter, different solutions based on the use of semantic models for representing clinical knowledge are presented. The aim of the research presented here is to contribute to the achievement of semantic interoperability by making explicit the meaning of the exchanged data and knowledge items. In particular, this work is focused on dual model-based electronic healthcare records standards and presents methods and tools for the representation and transformation of clinical archetypes and for the automatic generation of standardized applications.
Using Agent and Workflow Technologies for the Implementation of Interoperable Healthcare Information Systems
Authors: Koufi Vassiliki , Malamateniou Flora , Vassilacopoulos George
Published: May 2014

Healthcare is an increasingly collaborative enterprise involving many individuals and organizations that coordinate their efforts toward promoting quality and efficient delivery of healthcare through the use of interoperable healthcare information systems (HIS). Service-oriented architecture (SOA) provides a cost-effective solution to implementing interoperability between heterogeneous HIS which have resulted from extensive investments that most healthcare organizations have made in system resources over the course of many years. However, issues of semantic interoperability still remain unresolved while new challenges arise regarding web service interoperability. This chapter presents a mediator-based approach for achieving data and service interoperability among disparate and geographically dispersed HIS. The proposed system architecture provides a uniform interface to the underlying HIS, thus enabling decoupling of the client applications and the server-side implementations while it ensures security in all transactions. It is a distributed system architecture based on the agent paradigm for both healthcare process management and management of interactions among the participating systems. The healthcare processes and all interactions involved in each process are described according to the workflow metaphor. Thus, robustness, high flexibility and fault tolerance are provided in an environment as dynamic and heterogeneous as healthcare.
Enabling Interoperability of Patient Summaries across Europe with Triplespaces
Authors: Carenini Alessio , Cerri Davide , Krummenacher Reto , Simperl Elena
Published: May 2014

Healthcare services are naturally distributed, both from a geographical and an organisational point of view; they include various national and local authorities, as well as different actors ranging from general hospitals to individual physicians. One of the main items on the eHealth agenda of the European Union is the establishment of electronic patient summaries as an instrument to facilitate the pervasive delivery of healthcare and to guarantee its continuity across national boundaries. This chapter analyses several existing large-scale eHealth systems, chosen among the most prominent and established ones in Europe, and analyses their ability to cope with the high heterogeneity challenges of a Europe-wide solution. It then introduces triplespaces, a new-generation middleware based on the concept of semantic spaces, and presents a possible realisation of a European Patient Summary based on a triplespace infrastructure. The chapter shows that this solution can cope with the decentralisation, asynchronicity, subsidiarity, and security requirements arising in the European Patient Summary setting.
Big Data for Digital Government
Authors: Chen Yu-Che , Hsieh Tsui-Chuan
Published: May 2014

“Big data” is one of the emerging and critical issues facing government in the digital age. This study first delineates the defining features of big data (volume, velocity, and variety) and proposes a big data typology that is suitable for the public sector. This study then examines the opportunities of big data in generating business analytics to promote better utilization of information and communication technology (ICT) resources and improved personalization of e-government services. Moreover, it discusses the big data management challenges in building appropriate governance structure, integrating diverse data sources, managing digital privacy and security risks, and acquiring big data talent and tools. An effective big data management strategy to address these challenges should develop a stakeholder-focused and performance-oriented governance structure and build capacity for data management and business analytics as well as leverage and prioritize big data assets for performance. In addition, this study illustrates the opportunities, challenges, and strategy for big service data in government with the E-housekeeper program in Taiwan. This brief case study offers insight into the implementation of big data for improving government information and services. This article concludes with the main findings and topics of future research in big data for public administration.
Distinct Assembly Profiles of HLA-B Molecules
Authors: Rizvi Syed Monem , Salam Nasir , Geng Jie , Qi Ying , Bream Jay H. , Duggal Priya , Hussain Shehnaz K. , Martinson Jeremy , Wolinsky Steven M. , Carrington Mary , Raghavan Malini
Published: May 2014

MHC class I polymorphisms are known to influence outcomes in a number of infectious diseases, cancers, and inflammatory diseases. Human MHC class I H chains are encoded by the HLA-A, HLA-B, and HLA-C genes. These genes are highly polymorphic, with the HLA-B locus being the most variable. Each HLA class I protein binds to a distinct set of peptide Ags, which are presented to CD8+ T cells. HLA-disease associations have been shown in some cases to link to the peptide-binding characteristics of individual HLA class I molecules. In this study, we show that polymorphisms at the HLA-B locus profoundly influence the assembly characteristics of HLA-B molecules and the stabilities of their peptide-deficient forms. In particular, dependence on the assembly factor tapasin is highly variable, with frequent occurrence of strongly tapasin-dependent or independent allotypes. Several polymorphic HLA-B residues located near the C-terminal end of the peptide are key determinants of tapasin-independent assembly. In vitro refolded forms of tapasin-independent allotypes assemble more readily with peptides compared to tapasin-dependent allotypes that belong to the same supertype, and, during refolding, reduced aggregation of tapasin-independent allotypes is observed. Paradoxically, in HIV-infected individuals, greater tapasin-independent HLA-B assembly confers more rapid progression to death, consistent with previous findings that some HLA-B allotypes shown to be tapasin independent are associated with rapid progression to multiple AIDS outcomes. Together, these findings demonstrate significant variations in the assembly of HLA-B molecules and indicate influences of HLA-B–folding patterns upon infectious disease outcomes.
Adjustable Locks and Flexible Keys: Plasticity of Epitope–Paratope Interactions in Germline Antibodies
Authors: Khan Tarique , Salunke Dinakar M.
Published: May 2014

Ag recognition by independent primary Abs against a small flexible Ag with overlapping epitopes was analyzed to address the determinants of Ag specificity during the initial encounter. Crystal structures of two distinct dodecapeptide Ags, GDPRPSYISHLL and PPYPAWHAPGNI, in complex with the germline mAb 36-65 were determined and compared with the structures of the same Ags bound to another independent germline mAb, BBE6.12H3. For each peptide Ag, the two germline mAbs recognized overlapping epitopes, but in different topologies. The peptide structures differed, and the two paratopes attained discrete conformations, leading to different surface topologies, in a mode that can be described as adjustable locks and flexible keys. This is in contrast to mature mAbs, in which conformational convergence of different paratopes while binding to a common epitope in a similar conformation has been reported. These results suggest that the primary immune receptor repertoire is highly versatile as compared with its mature counterpart. Germline and mature mAbs adopt distinct mechanisms for recognizing a flexible epitope. Whereas conservation of conformational repertoire is a key characteristic of mature mAbs achieved through affinity maturation, the germline mAbs, at the initial stages of Ag encounter, maintain substantial plasticity, accommodating a broad specificity repertoire.
Cross-Dressing by Donor Dendritic Cells after Allogeneic Bone Marrow Transplantation Contributes to Formation of the Immunological Synapse and Maximizes Responses to Indirectly Presented Antigen
Authors: Markey Kate A. , Koyama Motoko , Gartlan Kate H. , Leveque Lucie , Kuns Rachel D. , Lineburg Katie E. , Teal Bianca E. , MacDonald Kelli P. A. , Hill Geoffrey R.
Published: May 2014

The stimulation of naive donor T cells by recipient alloantigen is central to the pathogenesis of graft-versus-host disease after bone marrow transplantation (BMT). Using mouse models of transplantation, we have observed that donor cells become “cross-dressed” in very high levels of recipient hematopoietic cell–derived MHC class I and II molecules following BMT. Recipient-type MHC is transiently present on donor dendritic cells (DCs) after BMT in the setting of myeloablative conditioning but is persistent after nonmyeloablative conditioning, in which recipient hematopoietic cells remain in high numbers. Despite the high level of recipient-derived alloantigen present on the surface of donor DCs, donor T cell proliferative responses are generated only in response to processed recipient alloantigen presented via the indirect pathway and not in response to cross-dressed MHC. Assays in which exogenous peptide is added to cross-dressed MHC in the presence of naive TCR transgenic T cells specific to the MHC class II–peptide combination confirm that cross-dressed APC cannot induce T cell proliferation in isolation. Despite failure to induce T cell proliferation, cross-dressing by donor DCs contributes to generation of the immunological synapse between DCs and CD4 T cells, and this is required for maximal responses induced by classical indirectly presented alloantigen. We conclude that the process of cross-dressing by donor DCs serves as an efficient alternative pathway for the acquisition of recipient alloantigen and that once acquired, this cross-dressed MHC can assist in immune synapse formation prior to the induction of full T cell proliferative responses by concurrent indirect Ag presentation.
All-transRetinoic Acid Induces Arginase-1 and Inducible Nitric Oxide Synthase–Producing Dendritic Cells with T Cell Inhibitory Function
Authors: Bhatt Sumantha , Qin Jie , Bennett Carole , Qian Shiguang , Fung John J. , Hamilton Thomas A. , Lu Lina
Published: May 2014

Hepatic stellate cells (HSC) are a major source of the immunoregulatory metabolite all-trans retinoic acid (ATRA), which may contribute to the generation of tolerogenic dendritic cells (DCs) in the liver. The present study seeks to clarify the mechanism(s) through which ATRA promotes the development of tolerogenic DCs. Although bone marrow–derived ATRA-treated DCs (RA-DCs) and conventional DCs had comparable surface phenotype, RA-DCs had diminished stimulatory capacity and could directly inhibit the expansion of DC/OVA-stimulated OT-II T cells. Arginase-1 (Arg-1) was found promote suppression because 1) ATRA was a potent inducer of Arg-1 protein and activity, 2) the Arg-1 inhibitor Nw-hydroxy nor-l-arginine partially reversed suppression, and 3) the suppressive function of RA-DCs was partially compromised using OT-II T cells from GCN2−/− mice, which are insensitive to Arg-1. Inducible NO synthase (iNOS), however, was found to be a more significant contributor to RA-DC function because 1) ATRA potentiated the expression of IFN-γ–induced iNOS, 2) suppressive function in RA-DCs was blocked by the iNOS inhibitor NG-monomethyl-l-arginine, monoacetate salt, and 3) RA-DCs derived from iNOS−/− mice exhibited near complete loss of tolerogenic function, despite sustained Arg-1 activity. The expression of iNOS and the suppressive function of RA-DCs were dependent on both IFN-γ and ATRA. Furthermore, the in vivo behavior of RA-DCs proved to be consistent with their in vitro behavior. Thus, we conclude that ATRA enhances both Arg-1 and iNOS expression in IFN-γ–treated DCs, resulting in a tolerogenic phenotype. These findings elucidate mechanisms through which ATRA may contribute to liver immune tolerance.
Sign Redesign: Applying Design Principles to Improve Signage in an Academic Library
Authors: Kasperek Sheila
Published: May 2014

When the Mansfield University library’s Special Events and Customer Service Committee created a communications plan for the library, the opportunity presented itself to overhaul the library signs. Applying basic design principles of contrast, alignment, and repetition along with standards from the Americans with Disabilities Act, the library improved the visual communications within the library. Patrons can now read signs from a distance and understand their purpose. Using common design elements, the library began presenting official library information more cohesively. Extending beyond signs, these design principles are now part of the library’s print publications and promotional items. With this consistency, the library brand is more easily recognizable both within the library and across campus. This article describes some basic elements of design and the process of redesigning the signs.
Basic Online Pennsylvania Legal Research for Librarians
Authors: Ax-Fultz Laura J.
Published: May 2014

Librarians engage in reference interviews where knowledge oflegal research is necessary, but they may not have formal training in legal research. Understanding a few basic elements of legal research will create a foundation of knowledge from which librarians can learn to effectively help patrons locate legal resources. The author presents these elements and describes their application in the context of researching free online Pennsylvania legal resources, including special advice to clarify the librarian’s role when working with patrons who are conducting legal research. The author also discusses the value of librarians creating a toolkit of free online Pennsylvania resources.
Increasing the Discoverability of Digital Collections Using Wikipedia: The Pitt Experience
Authors: Galloway Ed , DellaCorte Cassandra
Published: May 2014

During the Fall 2013 academic semester at the University of Pittsburgh, two undergraduate history majors performed a Wikipedia internship in the University Library System’s Archives Service Center and Special Collections Department. The purpose was to enhance the discoverability of Pitt’s digital collections and finding aids by creating links from Wikipedia articles to relevant content held by the library’s specialized collection units as well as to generally improve the quality of articles by adding additional information. By editing nearly 100 articles in Wikipedia, the interns developed their own effective strategies to perform this work and learned how to use and edit Wikipedia efficiently, how to navigate library resources effectively, how to decide what types of content would be valuable to add, and how to present new and respectable information. As a result, usage of Pitt’s online digitized collections and finding aids appears to have increased.
Noteworthy: News Briefs from PA Libraries
Authors: Neyer Linda , Gordon Larissa
Published: May 2014

News Briefs from Pennsylvania Libraries
Table of Contents
Authors: Reinsfelder Tom
Published: May 2014

Spring 2014 Table of Contents
Surgical Management of Symptomatic Posterior Circulation Aneurysms
Authors: Bozbuğa Mustafa , Süslü Hikmet Turan
Published: May 2014

Surgical treatment of posterior circulation aneurysms is more difficult than surgical treatment of anterior circulation aneurysms and poses a greater technical challenge for the practicing neurosurgeon. There are different surgical options available for the surgical treatment of posterior circulation aneurysms despite the use of the pterional approach to anterior circulation aneurysms. We present our surgical experiences with three cases of posterior circulation aneurysms. Three cases of posterior circulation aneurysms were treated by surgical clipping. We preferred pterional approach for posterior cerebral artery aneurysms, infratentorial supracerebellar approach for superior cerebellar aneurysm, and the combined lateral supracerebellar infratentorial retrosigmoid approach for vertebrobasilar junction aneurysm. The morbidity and mortality associated with open surgery for posterior circulation aneurysms are higher because of the location of the aneurysms within the posterior fossa. For neurosurgeons, the surgical treatment of posterior circulation aneurysms can be challenging.
Issues associated with use of dielectrics in drinking water systems
Authors: Clair Justin St. , Edwards Marc
Published: May 2014

Performance of dielectric configurations to reduce corrosion while meeting electrical codes in premise plumbing was examined and ranked as follows: bridged plastic pipe section > dielectric nipple > dielectric union > brass nipple ≈ dielectric spacer. When dielectrics were bridged with a grounding strap, the primary factor affecting galvanic performance was separation distance between the anodic and cathodic metal; however, some dielectrics offered other important advantages such as greater corrosion allowances (i.e., wall thickness) or reduced likelihood of clogging as a result of scale buildup (i.e., higher cross‐sectional flow area). Although bridged dielectrics do not completely stop galvanic corrosion, they can dramatically reduce galvanic corrosion while maintaining electrical continuity (satisfying electrical grounding requirements) between pipe sections.
Consistent boundary conditions at nonconducting surfaces of planetary bodies: Applications in a new Ganymede MHD model
Authors: Duling Stefan , Saur Joachim , Wicht Johannes
Published: May 2014

The interaction of planetary bodies with their surrounding magnetized plasma can often be described with the magnetohydrodynamic (MHD) equations, which are commonly solved by numerical models. For these models it is necessary to define physically correct boundary conditions for the plasma mass and energy density, the plasma velocity, and the magnetic field. Many planetary bodies have surfaces whose electrical conductivity is negligibly small and thus no electric current penetrates their surfaces. Magnetic boundary conditions, which consider that the associated radial electric current at the planetary surface is zero, are difficult to implement because they include the curl of the magnetic field. Here we derive new boundary conditions by a decomposition of the magnetic field in poloidal and toroidal parts. We find that the toroidal part of the magnetic field needs to vanish at the surface of the insulator. For the spherical harmonics coefficients of the poloidal part, we derive a Cauchy boundary condition, which also matches a possible intrinsic field by including its Gauss coefficients. Thus, we can additionally include planetary dynamo fields as well as time‐variable induction fields within electrically conductive subsurface layers. We implement the nonconducting boundary condition in the MHD simulation code ZEUS‐MP using spherical geometry and provide a numerical implementation in Fortran 90 as supporting information on the JGR website. We apply it to a model for Ganymede's plasma environment. Our model also includes a consistent set of boundary conditions for the other MHD variables density, velocity, and energy. With this model we can describe Galileo spacecraft observations in and around Ganymede's minimagnetosphere very well.
Nighttime sensitivity of ionospheric VLF measurements to X‐ray bursts from a remote cosmic source
Authors: Raulin Jean‐Pierre , Trottet Gérard , Giménez de Castro C. Guillermo , Correia Emilia , Macotela E. Liliana
Published: May 2014

On 22 January 2009, a series of X‐ray bursts were emitted by the soft gamma ray repeater SGR J1550‐5418. Some of these bursts produced enhanced ionization in the nighttime lower ionosphere. These ionospheric disturbances were studied using X‐ray measurements from the Anti‐Coincidence Shield of the Spectrometer for Integral onboard the International Gamma‐Ray Astrophysics Laboratory and simultaneous phase and amplitude records from two VLF propagation paths between the transmitter Naval Radio Station, Pearl Harbor (Hawaii) and the receivers Radio Observatorio do Itapetinga (Brazil) and Estação Antarctica Commandante Ferraz (Antarctic Peninsula). The VLF measurements have been obtained with an unprecedented high time resolution of 20 ms. We find that the illumination factor I (illuminated path length times the cosine of the zenith angle), which characterizes the propagation paths underlying the flaring object, is a key parameter which determines the sensitivity threshold of the VLF detection of X‐ray bursts from nonsolar transients. For the present VLF measurements of bursts from SGR J1550‐5418, it is found that for I ≥ 1.8 Mm, all X‐ray bursts with fluence in the 25 keV to 2 MeV range larger than F25_min ~ 1.0 × 10−6 erg/cm2 produce a measurable ionospheric disturbance. Such a lower limit of the X‐ray fluence value indicates that moderate X‐ray bursts, as opposed to giant X‐ray bursts, do produce ionospheric disturbances larger than the sensitivity limit of the VLF technique. Therefore, the frequency of detection of such events could be improved, for example by increasing the coverage of existing VLF receiving networks. The VLF detection of high‐energy astrophysical bursts then appears as an important observational diagnostic to complement their detection in space. This would be especially important when space observations suffer from adverse conditions, like saturation, occultation from the Earth, or the passage of the spacecraft through the South Atlantic anomaly.
Spatiotemporal evolution of seismic and aseismic slip on the Longitudinal Valley Fault, Taiwan
Authors: Thomas Marion Y. , Avouac Jean‐Philippe , Champenois Johann , Lee Jian‐Cheng , Kuo Long‐Chen
Published: May 2014

The Longitudinal Valley Fault (LVF) in eastern Taiwan is a high slip rate fault (about 5 cm/yr), which exhibits both seismic and aseismic slip. Deformation of anthropogenic features shows that aseismic creep accounts for a significant fraction of fault slip near the surface, whereas a fraction of the slip is also seismic, since this fault has produced large earthquakes with five Mw>6.8 events in 1951 and 2003. In this study, we analyze a dense set of geodetic and seismological data around the LVF, including campaign mode Global Positioning System(GPS) measurements, time series of daily solutions for continuous GPS stations (cGPS), leveling data, and accelerometric records of the 2003 Chenkung earthquake. To enhance the spatial resolution provided by these data, we complement them with interferometric synthetic aperture radar (InSAR) measurements produced from a series of Advanced Land Observing Satellite images processed using a persistent scatterer technique. The combined data set covers the entire LVF and spans the period from 1992 to 2010. We invert this data to infer the temporal evolution of fault slip at depth using the Principal Component Analysis‐based Inversion Method. This technique allows the joint inversion of diverse data, taking the advantage of the spatial resolution given by the InSAR measurements and the temporal resolution afforded by the cGPS data. We find that (1) seismic slip during the 2003 Chengkung earthquake occurred on a fault patch which had remained partially locked in the interseismic period, (2) the seismic rupture propagated partially into a zone of shallow aseismic interseismic creep but failed to reach the surface, and (3) that aseismic afterslip occurred around the area that ruptured seismically. We find consistency between geodetic and seismological constraints on the partitioning between seismic and aseismic creep. About 80–90% of slip on the southern section of LVF in the 0–26 km, seismogenic depth range, is actually aseismic. We infer that the clay‐rich Lichi Mélange is the key factor promoting aseismic creep at shallow depth.