bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of optimization algorithms for localized in vivo B0 shimming
Authors: Nassirpour Sahar , Chang Paul , Fillmer Ariane , Henning Anke 
Published: May 2017

PurposeTo compare several different optimization algorithms currently used for localized in vivo B0 shimming, and to introduce a novel, fast, and robust constrained regularized algorithm (ConsTru) for this purpose.MethodsTen different optimization algorithms (including samples from both generic and dedicated least‐squares solvers, and a novel constrained regularized inversion method) were implemented and compared for shimming in five different shimming volumes on 66 in vivo data sets from both 7 T and 9.4 T. The best algorithm was chosen to perform single‐voxel spectroscopy at 9.4 T in the frontal cortex of the brain on 10 volunteers.ResultsThe results of the performance tests proved that the shimming algorithm is prone to unstable solutions if it depends on the value of a starting point, and is not regularized to handle ill‐conditioned problems. The ConsTru algorithm proved to be the most robust, fast, and efficient algorithm among all of the chosen algorithms. It enabled acquisition of spectra of reproducible high quality in the frontal cortex at 9.4 T.ConclusionsFor localized in vivo B0 shimming, the use of a dedicated linear least‐squares solver instead of a generic nonlinear one is highly recommended. Among all of the linear solvers, the constrained regularized method (ConsTru) was found to be both fast and most robust. Magn Reson Med 79:1145–1156, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Multiresolution topology optimization using isogeometric analysis
Authors: Lieu Qui X. , Lee Jaehong 
Published: May 2017

SummaryThe paper introduces a novel multiresolution scheme to topology optimization in the framework of the isogeometric analysis. A new variable parameter space is added to implement multiresolution topology optimization based on the Solid Isotropic Material with Penalization approach. Design density variables defined in the variable space are used to approximate the element analysis density by the bivariate B‐spline basis functions, which are easily obtained using k‐refinement strategy in the isogeometric analysis. While the nonuniform rational B‐spline basis functions are used to exactly describe geometric domains and approximate unknown solutions in finite element analysis. By applying a refined sensitivity filter, optimized designs include highly discrete solutions in terms of solid and void materials without using any black and white projection filters. The Method of Moving Asymptotes is used to solve the optimization problem. Various benchmark test problems including plane stress, compliant mechanism inverter, and 2‐dimensional heat conduction are examined to demonstrate the effectiveness and robustness of the present method.
Volterra inverse scattering series method for one‐dimensional quantum barrier scattering
Authors: Chou Chia‐Chun , Yao Jie , Kouri Donald J. 
Published: May 2017

AbstractThe Volterra inverse scattering series method is developed to obtain the interaction potential for one‐dimensional quantum barrier scattering problems. The Lippmann–Schwinger equation describing quantum barrier scattering is renormalized from a Fredholm to a Volterra integral equation. Employing the Born–Neumann series solution of the Lippmann–Schwinger Volterra equation and a related expansion of the interaction potential in orders of the data, we derive the Volterra inverse scattering series for the reflection and transmission amplitudes. Each term of the interaction potential is computed using the scattering amplitude and the Volterra Green's function. We do not consider the separate issue of extracting scattering amplitudes from quantum cross sections. The triangular nature of the Volterra Green's function significantly reduces computational effort. The Volterra series is then applied to several one‐dimensional quantum barrier scattering problems. Computational results show that the first few terms in the Volterra series can yield accurate interaction barriers. In addition, the potential barriers are calculated using the Born inverse scattering series based on the Lippmann–Schwinger Fredholm equation with the reflection amplitude. The comparison between the Born and Volterra results demonstrates that the Volterra inverse scattering series can provide a more accurate and more efficient method for determining the interaction potential.
Concise Review: Induced Pluripotent Stem Cell-Based Drug Discovery for Mitochondrial Disease
Authors: Inak Gizem , Lorenz Carmen , Lisowski Pawel , Zink Annika , Mlody Barbara , Prigione Alessandro 
Published: May 2017

Abstract
High attrition rates and loss of capital plague the drug discovery process. This is particularly evident for mitochondrial disease that typically involves neurological manifestations and is caused by nuclear or mitochondrial DNA defects. This group of heterogeneous disorders is difficult to target because of the variability of the symptoms among individual patients and the lack of viable modeling systems. The use of induced pluripotent stem cells (iPSCs) might significantly improve the search for effective therapies for mitochondrial disease. iPSCs can be used to generate patient-specific neural cell models in which innovative compounds can be identified or validated. Here we discuss the promises and challenges of iPSC-based drug discovery for mitochondrial disease with a specific focus on neurological conditions. We anticipate that a proper use of the potent iPSC technology will provide critical support for the development of innovative therapies against these untreatable and detrimental disorders.
PRMT8 Controls the Pluripotency and Mesodermal Fate of Human Embryonic Stem Cells By Enhancing the PI3K/AKT/SOX2 Axis
Authors: Jeong Ho-Chang , Park Soon-Jung , Choi Jong-Jin , Go Young-Hyun , Hong Soon-Ki , Kwon Ok-Seon , Shin Joong-Gon , Kim Rae-Kwon , Lee Mi-Ok , Lee Su-Jae , Shin Hyoung Doo , Moon Sung-Hwan , Cha Hyuk-Jin 
Published: May 2017

AbstractBasic fibroblast growth factor (bFGF) supplementation is critical to maintain the pluripotency of human pluripotent stem cells (hPSCs) through activation of PI3K/AKT, rather than MEK/ERK pathway. Thus, elaborate molecular mechanisms that preserve PI3K/AKT signaling upon bFGF stimulation may exist in hPSCs. Protein arginine methyltransferase 8 (PRMT8) was expressed and then its level gradually decreased during spontaneous differentiation of human embryonic stem cells (hESCs). PRMT8 loss- or gain-of-function studies demonstrated that PRMT8 contributed to longer maintenance of hESC pluripotency, even under bFGF-deprived conditions. Direct interaction of membrane-localized PRMT8 with p85, a regulatory subunit of PI3K, was associated with accumulation of phosphoinositol 3-phosphate and consequently high AKT activity. Furthermore, the SOX2 induction, which was controlled by the PRMT8/PI3K/AKT axis, was linked to mesodermal lineage differentiation. Thus, we propose that PRMT8 in hESCs plays an important role not only in maintaining pluripotency but also in controlling mesodermal differentiation through bFGF signaling toward the PI3K/AKT/SOX2 axis.
Supporting Disciplinary Talk From the Start of School: Teaching Students to Think and Talk Like Scientists
Authors: Wright Tanya S. , Gotwals Amelia Wenk 
Published: May 2017

AbstractIn this article, the authors first review the research literature to show why supporting talk from the start of school is important for students’ long‐term literacy development. The authors then define and describe disciplinary talk and argue that it is an important entry point into science and disciplinary literacy learning for young students. The authors briefly describe their research project, which found success in improving students’ science talk:SOLIDStart (Science, Oral Language, and Literacy Development from the Start of School). The rest of the article describes theSOLIDStart instructional strategies for supporting disciplinary talk: the research that supports these strategies, examples of what each strategy looks like in primary‐grade classrooms, and how‐tos for teachers to start using these instructional strategies.
Including GHG emissions from mangrove forests LULUC in LCA: a case study on shrimp farming in the Mekong Delta, Vietnam
Authors: Järviö Natasha , Henriksson Patrik J. G. , Guinée Jeroen B. 
Published: May 2017

Abstract
Purpose
Mangrove forests have been recognized as important regulators of greenhouse gases (GHGs), yet the resulting land use and land-use change (LULUC) emissions have rarely been accounted for in life cycle assessment (LCA) studies. The present study therefore presents up-to-date estimates for GHG emissions from mangrove LULUC and applies them to a case study of shrimp farming in Vietnam.

Methods
To estimate the global warming impacts of mangrove LULUC, a combination of the International Panel for Climate Change (IPCC) guidelines, the Net Committed Emissions, and the Missed Potential Carbon Sink method were used. A literature review was then conducted to characterize the most critical parameters for calculating carbon losses, missed sequestration, methane fluxes, and dinitrogen monoxide emissions.

Results and discussion
Our estimated LUC emissions from mangrove deforestation resulted in 124 t CO2 ha−1 year−1, assuming IPCC’s recommendations of 1 m of soil loss, and 96% carbon oxidation. In addition to this, 1.25 t of carbon would no longer be sequestered annually. Discounted over 20 years, this resulted in total LULUC emissions of 129 t CO2 ha−1 year−1 (CV = 0.441, lognormal distribution (ln)). Shrimp farms in the Mekong Delta, however, can today operate for 50 years or more, but are 1.5 m deep (50% oxidation). In addition to this, Asian tiger shrimp farming in mixed mangrove concurrent farms (the only type of shrimp farm that resulted in mangrove deforestation since 2000 in our case study) resulted in 533 kg methane and 1.67 kg dinitrogen monoxide per hectare annually. Consequently, the LULUC GHG emissions resulted in 184 and 282 t CO2-eq t−1 live shrimp at farm gate, using mass and economic allocation, respectively. These GHG emissions are about an order of magnitude higher than from semi-intensive or intensive shrimp farming systems. Limitations in data quality and quantity also led us to quantify the uncertainties around our emission estimates, resulting in a CV of between 0.4 and 0.5.

Conclusions
Our results reinforce the urgency of conserving mangrove forests and the need to quantify uncertainties around LULUC emissions. It also questions mixed mangrove concurrent shrimp farming, where partial removal of mangrove forests is endorsed based upon the benefits of partial mangrove conservation and maintenance of certain ecosystem services. While we recognize that these activities limit the chances of complete removal, our estimates show that large GHG emissions from mangrove LULUC question the sustainability of this type of shrimp farming, especially since mixed mangrove farming only provide 5% of all farmed shrimp produced in Vietnam.
Manganese‐enhanced MR imaging (MEMRI) combined with electrophysiology in the study of cross‐modal plasticity in binocularly blind rats
Authors: Tang Zuohua , Wu Lingjie , Xiao Zebin , Sun Xinghuai , Feng Xiaoyuan , Chen Qian , Fan Jiawen , Wang Jie , Wang Wentao , Luo Jianfeng , Jin Lixin 
Published: May 2017

AbstractOur study aimed to determine and verify the establishment of visual to auditory cross‐modal plasticity using manganese‐enhanced MR imaging (MEMRI) combined with examinations of the visual evoked potential (VEP), auditory brainstem response (ABR) and bilateral visual cortex response to a bilateral auditory stimulus (AVR). Fourteen healthy male Sprague‐Dawley newborn rats were randomly divided into 2 groups (n = 7 per group). Optic nerve transection was performed in the 7 rats of Group A three weeks after birth to obtain binocularly blind models, and the 7 rats of Group B were maintained as the control group. The VEP was measured to ensure complete binocular blindness. Four months after the operation, MnCl2 was injected into the left inner ear perilymph of all rats, and an MRI examination was performed 24 h after injection. Then, ABR and AVR were measured to detect the generation of auditory compensatory function. The results of the VEP have confirmed complete binocular blindness. The normalized signal intensity of the bilateral medial geniculate nucleus, auditory cortex, visual center (including the lateral geniculate nucleus, superior colliculus and visual cortex) and right hippocampus in binocularly blind rats was significantly increased compared with that in normal rats (P ≤ 0.005), which was confirmed by measurement of the ABR and AVR. Our results suggested that MEMRI combined with electrophysiology can show changes in the auditory and visual pathways of binocularly blind rats and demonstrate the generation of an auditory compensatory pathway.
Viscosity and elasticity: a model intercomparison of ice-shelf bending in an Antarctic grounding zone
Authors: WILD CHRISTIAN T. , MARSH OLIVER J. , RACK WOLFGANG 
Published: May 2017

ABSTRACTGrounding zones are vital to ice-sheet mass balance and its coupling to the global ocean circulation. Processes here determine the mass discharge from the grounded ice sheet, to the floating ice shelves. The response of this transition zone to tidal forcing has been described by both elastic and viscoelastic models. Here we examine the validity of these models for grounding zone flexure over tidal timescales using field data from the Southern McMurdo Ice Shelf (78° 15′S, 167° 7′E). Observations of tidal movement were carried out by simultaneous tiltmeter and GPS measurements along a profile across the grounding zone. Finite-element simulations covering a 64 d period reveal that the viscoelastic model fits best the observations using a Young's modulus of 1.6 GPa and a viscosity of 1013.7 Pa s (≈ 50.1 TPa s). We conclude that the elastic model is only well-constrained for tidal displacements >35% of the spring-tidal amplitude using a Young's modulus of 1.62 ± 0.69 GPa, but that a viscoelastic model is necessary to adequately capture tidal bending at amplitudes below this threshold. In grounding zones where bending stresses are greater than at the Southern McMurdo Ice Shelf or ice viscosity is lower, the threshold would be even higher.
Inverse solution of surface mass balance of Midtre Lovénbreen, Svalbard
Authors: VÄLISUO ILONA , ZWINGER THOMAS , KOHLER JACK 
Published: May 2017

ABSTRACTWe investigate the temporal evolution and spatial distribution of mass balance on the glacier Midtre Lovénbreen, Svalbard. Running a diagnostic high-resolution full-stress ice flow model with geometries obtained from five digital elevation models (DEMs) in the period 1962–2005, we compute velocity fields and linearly interpolated volume change of the glacier. We evaluate the kinematic free surface equation using these model outputs to solve the surface mass balance (SMB). Monitoring data on Midtre Lovénbreen allows model results to be compared with point measurements from the glacier over several decades. This method allows us to estimate the mass balance over the entire glacier surface, beyond the spatially limited field measurements, and to derive past SMB over an extended time period.
Drones on ice: an assessment of the legal implications of the use of unmanned aerial vehicles in scientific research and by the tourist industry in Antarctica
Authors: Leary David 
Published: May 2017

ABSTRACTUnmanned aerial vehicles (UAVs), also known as drones, are used in scientific research and a diverse range of other applications across the globe. They are also being used increasingly for scientific research in Antarctica and to a lesser extent by tourists visiting the world's last great frontier tourist destination. Their use in scientific research in Antarctica offers many benefits to science and if used responsibly may be less invasive than other research techniques, offering a rich source of new scientific data. For tourists, UAVs also offer unique aerial photographic perspectives on Antarctica — the ultimate holiday snap shot. Concerns have been raised about the safety of drone use in the harsh and unpredictable Antarctic conditions, as well as possible environmental impacts. This paper considers these issues and the emerging regulatory response to drone use in Antarctica focusing on theAntarctic Unmanned Aerial Systems (UAS) Operator's Handbook, which provides guidelines to national Antarctic programmes on the use of UAVs in the Antarctic Treaty area, and the temporary ban on use of drones by tourists imposed by the International Association of Antarctica Tour Operators (IAATO). Both measures arguably constitute a good first response to this emerging issue, although more still needs to be done.
Anorectal swabs as a marker of male-to-male sexual exposure in STI surveillance systems
Authors: AMPT F. H. , EL HAYEK C. , AGIUS P. A. , BOWRING A. L. , BARTNIK N. , VAN GEMERT C. , FAIRLEY C. K. , CHOW E. P. F. , BRADSHAW C. S. , STEPHENS N. , LIM M. S. C. , HELLARD M. E. 
Published: May 2017

SUMMARYIdentification of priority populations such as men who have sex with men (MSM) is important in surveillance systems to monitor trends of sexually transmitted infections (STIs). We explored using routinely collected non-behavioural data as a means to establish MSM status in surveillance by assessing anorectal swab as a marker of male-to-male sexual exposure. We used chlamydia testing data from a sexual health clinic, 2007–2012. Men reporting any male sexual partner(s) in the previous 12 months were considered MSM. The dataset was split into development and validation samples to develop a univariate predictive model and assess the model fit. The dataset included 30 358 individual men and 48 554 episodes of STI testing; 45% were among reported MSM and an anorectal swab was performed in 40% of testing episodes. Anorectal swabbing had good diagnostic performance as a marker for MSM status (sensitivity = 87%, specificity = 99%, positive predictive value = 98·6%, negative predictive value = 90·3%). The model showed good fit against the internal validation sample (area under the curve = 0·93). Anorectal swabs are a valid marker of MSM behaviour in surveillance data from sexual health clinics, and they are likely to be particularly useful for monitoring STI trends among MSM with higher risk behaviour.
Automated Image Acquisition for Low-Dose STEM at Atomic Resolution
Authors: Mittelberger Andreas , Kramberger Christian , Hofer Christoph , Mangler Clemens , Meyer Jannik C. 
Published: May 2017

AbstractBeam damage is a major limitation in electron microscopy that becomes increasingly severe at higher resolution. One possible route to circumvent radiation damage, which forms the basis for single-particle electron microscopy and related techniques, is to distribute the dose over many identical copies of an object. For the acquisition of low-dose data, ideally no dose should be applied to the region of interest before the acquisition of data. We present an automated approach that can collect large amounts of data efficiently by acquiring images in a user-defined area-of-interest with atomic resolution. We demonstrate that the stage mechanics of the Nion UltraSTEM, combined with an intelligent algorithm to move the sample, allow the automated acquisition of atomically resolved images from micron-sized areas of a graphene substrate. Moving the sample stage automatically in a regular pattern over the area-of-interest enables the collection of data from pristine sample regions without exposing them to the electron beam before recording an image. Therefore, it is possible to obtain data with minimal dose (no prior exposure during focusing), which is only limited by the minimum signal needed for data processing. This enables us to minimize beam-induced damage in the sample and to acquire large data sets within a reasonable amount of time.
The emergence of personal growth amongst healthcare professionals who care for dying children
Authors: Beaune Laura , Muskat Barbara , Anthony Samantha J. 
Published: May 2017

ABSTRACTObjective:Compassion fatigue, burnout, and vicarious traumatization are prominent topics in the current literature on the impact of the rewarding but challenging work of healthcare professionals who care for patients with life-limiting illnesses. The positive effects of caregiving constitute a newly emerging outcome that has been relatively unexplored in the pediatric literature, and yet they may play an important role in contributing to the satisfaction and well-being of the healthcare professionals who care for children who have a life-limiting illness.Method:This paper reports the results of a secondary analysis of qualitative interview transcripts that explored the experiences of hospital-based pediatric healthcare providers caring for children with varied life-limiting illnesses. In-depth qualitative interviews were conducted with 25 healthcare professionals (9 social workers, 8 nurses, and 8 physicians). The majority of participants were women (80%), with an age range between 20 and 60 years, and most (84%) had the experience of caring for more than 15 dying children. Thematic analysis was conducted using interpretive description and constant comparison.Results:Every healthcare professional interviewed experienced personal growth as a result of their providing care for dying children. Three dimensions of personal growth were most consistently reported: (1) new or altered life perspectives, (2) enhanced personal resources, and (3) benevolence.Significance of results:A deeper understanding of the phenomenon of personal growth could help healthcare organizations to implement innovative approaches that would counterbalance compassion fatigue, and thereby enhance both healthcare provider well-being and child and family outcomes.
Fair Topologies: Community Structures and Network Hubs Drive Emergence of Fairness Norms
Authors: Mosleh Mohsen , Heydari Babak 
Published: May 2017

AbstractFairness has long been argued to govern human behavior in a wide range of social, economic, and organizational activities. The sense of fairness, although universal, varies across different societies. In this study, using a computational model, we test the hypothesis that the topology of social interaction can causally explain some of the cross-societal variations in fairness norms. We show that two network parameters, namely, community structure, as measured by the modularity index, and networkhubiness, represented by the skewness of degree distribution, have the most significant impact on emergence of collective fair behavior. These two parameters can explain much of the variations in fairness norms across societies and can also be linked to hypotheses suggested by earlier empirical studies in social and organizational sciences. We devised a multi-layered model that combines local agent interactions with social learning, thus enables both strategic behavior as well as diffusion of successful strategies. By applying multivariate statistics on the results, we obtain the relation between network structural features and the collective fair behavior.